This document discusses microbial interactions, including both positive and negative interactions. It provides examples of symbiotic relationships between microbes and plants, such as lichens and nitrogen-fixing bacteria in legume roots. Microbial interactions with animals are also discussed, including relationships between rumen microbes and ruminant digestion. The document concludes by examining the interaction between the human microbiome and the host.
The document discusses various types of interactions between microorganisms including mutualism, commensalism, parasitism, predation, competition, and synergism. Specific examples are provided for each type of interaction such as lichens exhibiting mutualism between fungi and cyanobacteria. Both beneficial and harmful relationships between microbes and other organisms like plants, animals, and humans are explored.
Bacteriophages & Its classification, cycles, therapy, and applicationsZoqiaTariq
These slides are covering multiple aspects of Bacteriophages including History
Classification
Replication
Plaque Assay
Transduction
Phage Therapy and pahge types.
This document discusses chemolithotrophs, which are organisms that obtain energy from oxidizing inorganic or organic compounds. It notes that chemolithotrophs, also called chemolithoautotrophs, were first studied by Sergei Winogradsky in sulfur bacteria. Chemolithotrophs face challenges due to the lower energy availability from oxidizing inorganic compounds compared to organics, and solutions include oxidizing more substrate and using reverse electron flow. The document categorizes chemolithotrophs as aerobic, using oxygen as the terminal electron acceptor, or anaerobic, using other compounds besides oxygen.
Culture Collection Center National and International RinuRolly
Culture collection , Purpose of culture collection center and some famous International Culture Collection Center and National Culture Collection Centers of India .
This document discusses life under extreme environmental conditions and focuses on extremophiles - organisms that thrive in extreme temperatures, acidity, salinity, or other stressful conditions. It provides examples of thermophiles that live in high temperatures, psychrophiles that thrive in cold temperatures, and halophiles that survive in highly saline environments. The key adaptations that allow extremophiles to survive their extreme habitats are also summarized, such as membrane modifications, stress proteins, and organic solutes that regulate osmotic balance.
Microbes play an important role in bioremediation by using their enzymatic activity to destroy pollutants or transform them into less harmful forms. During their normal metabolic processes, microbes can break down toxic compounds and convert them into simpler, non-toxic molecules. Bioremediation harnesses microbes' natural degradation abilities to clean contaminated sites using biological rather than physical or chemical methods. This approach is often more cost-effective and environmentally friendly compared to excavating and disposing of polluted soils and water.
This document describes different methods for assessing air quality by sampling and quantifying airborne microorganisms. It discusses the principles and procedures for sedimentation, impaction, impingement, and filtration air sampling techniques. Impaction uses inertia to deposit particles on a collection surface like agar. Impingement traps particles in a liquid that is then plated. Filtration collects particles on membrane filters which are cultured. The document provides materials needed and step-by-step instructions to sample air using an AGI-30 impinger or cassette filtration to collect microbes which are then cultured and counted to quantify bacteria and fungi concentrations per cubic meter of air.
The document discusses various types of interactions between microorganisms including mutualism, commensalism, parasitism, predation, competition, and synergism. Specific examples are provided for each type of interaction such as lichens exhibiting mutualism between fungi and cyanobacteria. Both beneficial and harmful relationships between microbes and other organisms like plants, animals, and humans are explored.
Bacteriophages & Its classification, cycles, therapy, and applicationsZoqiaTariq
These slides are covering multiple aspects of Bacteriophages including History
Classification
Replication
Plaque Assay
Transduction
Phage Therapy and pahge types.
This document discusses chemolithotrophs, which are organisms that obtain energy from oxidizing inorganic or organic compounds. It notes that chemolithotrophs, also called chemolithoautotrophs, were first studied by Sergei Winogradsky in sulfur bacteria. Chemolithotrophs face challenges due to the lower energy availability from oxidizing inorganic compounds compared to organics, and solutions include oxidizing more substrate and using reverse electron flow. The document categorizes chemolithotrophs as aerobic, using oxygen as the terminal electron acceptor, or anaerobic, using other compounds besides oxygen.
Culture Collection Center National and International RinuRolly
Culture collection , Purpose of culture collection center and some famous International Culture Collection Center and National Culture Collection Centers of India .
This document discusses life under extreme environmental conditions and focuses on extremophiles - organisms that thrive in extreme temperatures, acidity, salinity, or other stressful conditions. It provides examples of thermophiles that live in high temperatures, psychrophiles that thrive in cold temperatures, and halophiles that survive in highly saline environments. The key adaptations that allow extremophiles to survive their extreme habitats are also summarized, such as membrane modifications, stress proteins, and organic solutes that regulate osmotic balance.
Microbes play an important role in bioremediation by using their enzymatic activity to destroy pollutants or transform them into less harmful forms. During their normal metabolic processes, microbes can break down toxic compounds and convert them into simpler, non-toxic molecules. Bioremediation harnesses microbes' natural degradation abilities to clean contaminated sites using biological rather than physical or chemical methods. This approach is often more cost-effective and environmentally friendly compared to excavating and disposing of polluted soils and water.
This document describes different methods for assessing air quality by sampling and quantifying airborne microorganisms. It discusses the principles and procedures for sedimentation, impaction, impingement, and filtration air sampling techniques. Impaction uses inertia to deposit particles on a collection surface like agar. Impingement traps particles in a liquid that is then plated. Filtration collects particles on membrane filters which are cultured. The document provides materials needed and step-by-step instructions to sample air using an AGI-30 impinger or cassette filtration to collect microbes which are then cultured and counted to quantify bacteria and fungi concentrations per cubic meter of air.
This document discusses various types of microbial interactions:
- Positive interactions include symbiosis (mutualism, protocooperation, commensalism) where organisms benefit each other. Examples given are lichens and protozoan-termite symbiosis.
- Negative interactions include antagonism, amensalism, predation, parasitism, and competition. In antagonism, one organism inhibits another. In amensalism and predation one benefits while the other is harmed. Parasitism also harms the host. Competition adversely affects both interacting organisms.
- Specific examples discussed include lactic acid bacteria inhibiting pathogens, Bdellovibrio as a bacterial predator, and viral
1. Microbial associations refer to the close relationships between microorganisms, which can include mutualism, commensalism, and antagonism. Mutualism benefits both microorganisms, commensalism benefits one without affecting the other, and antagonism involves predation or parasitism where one benefits at the expense of the other.
2. Examples of microbial associations include nitrogen-fixing bacteria that live symbiotically in plant root nodules, fungi and algae that form lichens, and microbes in animal digestive systems that aid in breaking down food.
3. These associations play important roles in the environment, from nutrient cycling to industrial applications like producing antibiotics and fermented foods
The document discusses key concepts related to host-pathogen relationships and the occurrence and spread of infectious diseases. It defines important terms like infection, disease, colonization, and defines the roles of the host and pathogen. It describes the chain of infection and factors that influence a host's resistance or susceptibility to disease. It also outlines common routes of entry for pathogens, signs and symptoms for different types of infections, and ways that pathogens can spread within the body and between hosts through different modes of transmission.
This document discusses the microbiology of air, including aero-microbiology, transmission of airborne microorganisms, common bacterial and fungal species found in indoor and outdoor air, and airborne diseases like tuberculosis, meningitis, influenza, and histoplasmosis. It also covers physical stresses on microorganisms in the air and methods to control microorganisms, such as ultraviolet radiation, chemical agents, filtration, and laminar airflow systems.
Microbial interactions are ubiquitous, diverse, critically important in the function of any biological community.
The most common cooperative interactions seen in microbial systems are mutually beneficial. The interactions between the two populations are classified according to whether both populations and one of them benefit from the associations, or one or both populations are negatively affected.
This document discusses the microbial flora of soil. It defines soil microflora as microorganisms that contribute to the biological properties of soil, including bacteria, fungi, algae, and protozoa. The five major groups interact and form a soil food web, with bacteria and fungi serving important roles in decomposition. Physical and chemical factors like pH and nutrients influence the growth and activity of soil microflora. The microflora are then classified and examples are given of bacteria, fungi, algae, protozoa, and their functions in the soil ecosystem.
Microorganisms are commonly found suspended in air, including bacteria, fungi, algae, viruses, and protozoa. The most important factors affecting the types and numbers of airborne microorganisms are temperature, humidity, and air currents. While air is not suitable for microbial growth, it acts as a transport medium for microbes picked up from environmental sources like soil, water, and human activities like coughing and sneezing. Methods to isolate microorganisms from air samples include impingement onto solid or into liquid collection media, followed by incubation and counting of colonies.
this presentation show details regarding how the concept of agricultural microbiology came into existance and also the contribution of various scientists
Introduction
Type of pesticides
Advantage & disadvantages of pesticides
Degradation of pesticide
Microbial degradation of pesticides
Mode of microbial metabolism of pesticides
Strategies for biodegradation
Approaches for biodegradation of pesticide
Chemical reaction leading biodegradation of pesticide
Metabolism of pesticides by MO
Metabolism of DDT
This document describes several methods for isolating and detecting bacterial mutants, including replica plating, penicillin enrichment, and the Ames test. Replica plating involves transferring bacterial colonies from a "master plate" to replica plates with and without an amino acid to identify auxotrophic mutants. The penicillin enrichment technique also detects auxotrophs. The Ames test uses Salmonella strains to evaluate whether a chemical is mutagenic based on its ability to increase histidine revertants, indicating DNA damage. Chromogenic substrates can identify mutants unable to utilize substances like lactose due to lacking the enzyme beta-galactosidase.
This document discusses methods for enumerating viruses, including direct and indirect methods. Direct enumeration methods like direct electron microscopic count can directly count virus particles but have difficulties. The latex bead method helps minimize issues by adding beads of known concentration. Indirect methods rely on infectivity, including plaque assays where each plaque indicates one infective virus particle, and pock assays used for viruses like pox that form visible lesions. Both indirect methods involve serial dilutions and counting visible plaques or pocks to calculate virus concentration in the original sample.
Actinomycetes are a diverse group of filamentous, gram-positive bacteria. They are classified within the domain bacteria and phylum Actinobacteria. Actinomycetes live predominantly in soil where they help break down recalcitrant compounds. While most species are harmless, some can cause infections in humans called actinomycosis. Important genera include Actinomyces, Nocardia, and Streptomyces. Actinomycetes are distinguished from fungi by being prokaryotic, containing peptidoglycan in their cell walls rather than chitin, and having smaller filaments. Diagnosis of actinomycosis involves identifying the pathogen's sulfur granules in biopsy samples
Extremophilic organisms are organisms that can survive exremities that are detrimental for other forms of life. Here is a presentation that discuss such microorganisms in detail
Microbial taxonomy and classification systemSakshi Saxena
- Taxonomy is the science of describing, naming, and classifying organisms. It provides understanding of biodiversity which is important for conservation and sustainability.
- Aristotle was the first to attempt classifying organisms by type and introduce binomial nomenclature. Later systems were proposed by Linnaeus, Whittaker, and Woese based on new understandings of cell structure, genetics, and evolution.
- Different classification systems include artificial, natural, phylogenetic, polyphasic, and numerical taxonomy which use varying characteristics and methodologies.
Rohit Jadhav presented on microbe-plant interactions. Key points include:
- Cyanobacteria and rhizobia have symbiotic relationships with plants, fixing nitrogen.
- Microbes in the rhizosphere and rhizoplane interact with plant roots, satisfying nutritional needs for both.
- Rhizosphere microbes can positively impact plants by nutrient solubilization or negatively through immobilization.
- Legumes form root nodules with rhizobia like Rhizobium spp. and Bradyrhizobium spp. to fix atmospheric nitrogen.
- Some non-legumes interact with nitrogen-fixing cyanobacteria and Frankia bacteria inside root nodules.
-
IntroductionDefinitionPescidesType of pesticidesFate of pesticides in environmentBiodegradation of pesticides in soil Criteria for biodegradation
Strategies for biodegradationDifferent approaches of biodegradationChemical reaction leading to biodegradationChanging the spectrum of toxicityExample of biodegradationAdvantageDisadvantage
he rhizosphere is the narrow region of soil or substrate that is directly influenced by root secretions and associated soil microorganisms known as the root microbiome.
The phyllosphere is a term used in microbiology to refer to the total above-ground portions of plants as habitat for microorganisms.
This document discusses aero-microbiology, which is the study of microorganisms that are suspended in air. It notes that microbes can be transmitted through the air via coughing, sneezing, or being carried by dust or droplet nuclei. Various airborne diseases caused by bacteria, viruses, and fungi are described, including how they are transmitted and their symptoms. The document also outlines some methods to control microorganisms in the air, such as through ultraviolet radiation, chemical agents, filtration, and laminar airflow systems.
Principles of disease and epidemiology printBilalHoushaymi
This document discusses principles of disease epidemiology and microbiology. It defines key terms like pathology, etiology, pathogenesis, and normal human microbiota. It describes Koch's postulates for identifying disease causation and classifies infectious diseases based on characteristics like communicability, incidence, prevalence, and host involvement. The stages of disease and factors that influence disease transmission and occurrence are examined. Nosocomial infections and emerging infectious diseases are also summarized.
This document discusses pathology, infection, disease, and the normal human microbiota. It defines key terms like pathology, etiology, pathogenesis, infection, and disease. It describes the normal bacteria that colonize different parts of the human body like the skin, nose, mouth, and intestines. The document outlines the relationship between the human microbiota and host, including microbial antagonism, symbiosis, and opportunistic pathogens. It also discusses Koch's postulates and approaches to studying disease epidemiology and transmission patterns.
This document discusses various types of microbial interactions:
- Positive interactions include symbiosis (mutualism, protocooperation, commensalism) where organisms benefit each other. Examples given are lichens and protozoan-termite symbiosis.
- Negative interactions include antagonism, amensalism, predation, parasitism, and competition. In antagonism, one organism inhibits another. In amensalism and predation one benefits while the other is harmed. Parasitism also harms the host. Competition adversely affects both interacting organisms.
- Specific examples discussed include lactic acid bacteria inhibiting pathogens, Bdellovibrio as a bacterial predator, and viral
1. Microbial associations refer to the close relationships between microorganisms, which can include mutualism, commensalism, and antagonism. Mutualism benefits both microorganisms, commensalism benefits one without affecting the other, and antagonism involves predation or parasitism where one benefits at the expense of the other.
2. Examples of microbial associations include nitrogen-fixing bacteria that live symbiotically in plant root nodules, fungi and algae that form lichens, and microbes in animal digestive systems that aid in breaking down food.
3. These associations play important roles in the environment, from nutrient cycling to industrial applications like producing antibiotics and fermented foods
The document discusses key concepts related to host-pathogen relationships and the occurrence and spread of infectious diseases. It defines important terms like infection, disease, colonization, and defines the roles of the host and pathogen. It describes the chain of infection and factors that influence a host's resistance or susceptibility to disease. It also outlines common routes of entry for pathogens, signs and symptoms for different types of infections, and ways that pathogens can spread within the body and between hosts through different modes of transmission.
This document discusses the microbiology of air, including aero-microbiology, transmission of airborne microorganisms, common bacterial and fungal species found in indoor and outdoor air, and airborne diseases like tuberculosis, meningitis, influenza, and histoplasmosis. It also covers physical stresses on microorganisms in the air and methods to control microorganisms, such as ultraviolet radiation, chemical agents, filtration, and laminar airflow systems.
Microbial interactions are ubiquitous, diverse, critically important in the function of any biological community.
The most common cooperative interactions seen in microbial systems are mutually beneficial. The interactions between the two populations are classified according to whether both populations and one of them benefit from the associations, or one or both populations are negatively affected.
This document discusses the microbial flora of soil. It defines soil microflora as microorganisms that contribute to the biological properties of soil, including bacteria, fungi, algae, and protozoa. The five major groups interact and form a soil food web, with bacteria and fungi serving important roles in decomposition. Physical and chemical factors like pH and nutrients influence the growth and activity of soil microflora. The microflora are then classified and examples are given of bacteria, fungi, algae, protozoa, and their functions in the soil ecosystem.
Microorganisms are commonly found suspended in air, including bacteria, fungi, algae, viruses, and protozoa. The most important factors affecting the types and numbers of airborne microorganisms are temperature, humidity, and air currents. While air is not suitable for microbial growth, it acts as a transport medium for microbes picked up from environmental sources like soil, water, and human activities like coughing and sneezing. Methods to isolate microorganisms from air samples include impingement onto solid or into liquid collection media, followed by incubation and counting of colonies.
this presentation show details regarding how the concept of agricultural microbiology came into existance and also the contribution of various scientists
Introduction
Type of pesticides
Advantage & disadvantages of pesticides
Degradation of pesticide
Microbial degradation of pesticides
Mode of microbial metabolism of pesticides
Strategies for biodegradation
Approaches for biodegradation of pesticide
Chemical reaction leading biodegradation of pesticide
Metabolism of pesticides by MO
Metabolism of DDT
This document describes several methods for isolating and detecting bacterial mutants, including replica plating, penicillin enrichment, and the Ames test. Replica plating involves transferring bacterial colonies from a "master plate" to replica plates with and without an amino acid to identify auxotrophic mutants. The penicillin enrichment technique also detects auxotrophs. The Ames test uses Salmonella strains to evaluate whether a chemical is mutagenic based on its ability to increase histidine revertants, indicating DNA damage. Chromogenic substrates can identify mutants unable to utilize substances like lactose due to lacking the enzyme beta-galactosidase.
This document discusses methods for enumerating viruses, including direct and indirect methods. Direct enumeration methods like direct electron microscopic count can directly count virus particles but have difficulties. The latex bead method helps minimize issues by adding beads of known concentration. Indirect methods rely on infectivity, including plaque assays where each plaque indicates one infective virus particle, and pock assays used for viruses like pox that form visible lesions. Both indirect methods involve serial dilutions and counting visible plaques or pocks to calculate virus concentration in the original sample.
Actinomycetes are a diverse group of filamentous, gram-positive bacteria. They are classified within the domain bacteria and phylum Actinobacteria. Actinomycetes live predominantly in soil where they help break down recalcitrant compounds. While most species are harmless, some can cause infections in humans called actinomycosis. Important genera include Actinomyces, Nocardia, and Streptomyces. Actinomycetes are distinguished from fungi by being prokaryotic, containing peptidoglycan in their cell walls rather than chitin, and having smaller filaments. Diagnosis of actinomycosis involves identifying the pathogen's sulfur granules in biopsy samples
Extremophilic organisms are organisms that can survive exremities that are detrimental for other forms of life. Here is a presentation that discuss such microorganisms in detail
Microbial taxonomy and classification systemSakshi Saxena
- Taxonomy is the science of describing, naming, and classifying organisms. It provides understanding of biodiversity which is important for conservation and sustainability.
- Aristotle was the first to attempt classifying organisms by type and introduce binomial nomenclature. Later systems were proposed by Linnaeus, Whittaker, and Woese based on new understandings of cell structure, genetics, and evolution.
- Different classification systems include artificial, natural, phylogenetic, polyphasic, and numerical taxonomy which use varying characteristics and methodologies.
Rohit Jadhav presented on microbe-plant interactions. Key points include:
- Cyanobacteria and rhizobia have symbiotic relationships with plants, fixing nitrogen.
- Microbes in the rhizosphere and rhizoplane interact with plant roots, satisfying nutritional needs for both.
- Rhizosphere microbes can positively impact plants by nutrient solubilization or negatively through immobilization.
- Legumes form root nodules with rhizobia like Rhizobium spp. and Bradyrhizobium spp. to fix atmospheric nitrogen.
- Some non-legumes interact with nitrogen-fixing cyanobacteria and Frankia bacteria inside root nodules.
-
IntroductionDefinitionPescidesType of pesticidesFate of pesticides in environmentBiodegradation of pesticides in soil Criteria for biodegradation
Strategies for biodegradationDifferent approaches of biodegradationChemical reaction leading to biodegradationChanging the spectrum of toxicityExample of biodegradationAdvantageDisadvantage
he rhizosphere is the narrow region of soil or substrate that is directly influenced by root secretions and associated soil microorganisms known as the root microbiome.
The phyllosphere is a term used in microbiology to refer to the total above-ground portions of plants as habitat for microorganisms.
This document discusses aero-microbiology, which is the study of microorganisms that are suspended in air. It notes that microbes can be transmitted through the air via coughing, sneezing, or being carried by dust or droplet nuclei. Various airborne diseases caused by bacteria, viruses, and fungi are described, including how they are transmitted and their symptoms. The document also outlines some methods to control microorganisms in the air, such as through ultraviolet radiation, chemical agents, filtration, and laminar airflow systems.
Principles of disease and epidemiology printBilalHoushaymi
This document discusses principles of disease epidemiology and microbiology. It defines key terms like pathology, etiology, pathogenesis, and normal human microbiota. It describes Koch's postulates for identifying disease causation and classifies infectious diseases based on characteristics like communicability, incidence, prevalence, and host involvement. The stages of disease and factors that influence disease transmission and occurrence are examined. Nosocomial infections and emerging infectious diseases are also summarized.
This document discusses pathology, infection, disease, and the normal human microbiota. It defines key terms like pathology, etiology, pathogenesis, infection, and disease. It describes the normal bacteria that colonize different parts of the human body like the skin, nose, mouth, and intestines. The document outlines the relationship between the human microbiota and host, including microbial antagonism, symbiosis, and opportunistic pathogens. It also discusses Koch's postulates and approaches to studying disease epidemiology and transmission patterns.
This document provides an overview of host-microbe relationships and disease processes. It defines key terminology related to pathology, infection, disease transmission, and clinical microbiology. It discusses Koch's postulates for establishing disease causation, different types of host-microbe interactions, and factors that influence disease patterns and spread. The document also outlines methods for isolating clinical samples, performing antimicrobial sensitivity testing, and interpreting minimum inhibitory concentration results.
INFECTION AND INFECTIOUS PROCEعمللياSS.pptxssuser139631
This document discusses infection and infectious processes. It defines infection and classifications of infections such as primary, secondary, and focal infections. It describes sources of infection in humans such as other humans, animals, insects, soil, water, and food. Methods of transmission include contact, inhalation, ingestion, inoculation, and congenitally. Factors that contribute to microbial pathogenicity include adhesion, invasiveness, and toxins. The document also discusses types of infectious diseases and stages of infectious disease.
This document discusses infection and infectious processes. It defines infection and classifies different types of infections such as primary, secondary, and nosocomial infections. It describes the sources of infections in humans which can come from other humans, animals, insects, soil, water, and food. It also outlines various methods of transmitting infections like contact, inhalation, ingestion, inoculation, and congenitally. Factors that contribute to microbial pathogenicity include adhesion, invasiveness, toxigenicity, communicability, and bacterial appendages. The document also differentiates between endemic, epidemic, and pandemic diseases and describes the stages of infectious diseases. Finally, it discusses biofilms, quorum sensing, and characteristics of biofilm formation
This document provides an overview of infectious diseases and the agents that cause them. It discusses the historical perspective of major infectious diseases like smallpox, plague, and influenza. It describes Robert Koch's pioneering work in the late 19th century that established the germ theory of disease and his criteria (known as Koch's postulates) for identifying disease-causing agents. The document then covers viruses, bacteria, fungi, protozoa, helminths, prions, and ectoparasites as causes of infectious disease, describing their characteristics, life cycles, modes of transmission, and examples of diseases they cause.
Viruses are very small infectious agents that can only replicate inside host cells. They contain genetic material (DNA or RNA) surrounded by a protein coat. There are many types of viral infections that affect different body systems like the respiratory, gastrointestinal, liver, nervous and skin. Respiratory viruses commonly cause infections like influenza and COVID-19. Some viruses are also associated with certain cancers through their ability to insert their genetic material into host cells. Proper hygiene practices, vaccination and antiviral treatment can help prevent and treat viral infections.
The document defines key terms related to bacterial pathogenicity and mechanisms by which bacteria cause disease. It discusses how bacteria penetrate host defenses through adherence, capsules, and enzymes. It also describes the role of toxins, including exotoxins and endotoxins, in bacterial pathogenesis. The summary provides an overview of the main points covered in the document.
Infection occurs when a microbe lodges and multiplies in the tissues of a host. Ranges of relationships between microbes and hosts include saprophytes, parasites, and commensals. Several factors predispose to microbial pathogenicity, including adhesion, invasiveness, and toxigenicity. Infections can be classified as acute or chronic, primary or secondary, localized or systemic, and clinical or subclinical. Six links must be present for an infection to spread: a portal of entry, a susceptible host, a causative agent, a reservoir, a portal of exit, and a mode of transmission. Microbes can be transmitted through various methods including direct or indirect contact, inhalation, ingestion
Term and Definitions regarding microbiology, Pathogenicity and virulency, acute and chronic infection, primary and secondary infection, opportunistic infection.
Unit 6 Infectious diseases & immunity - shortend.pdfAlemu Chemeda
The document provides an overview of infectious diseases and immunity. It discusses key topics including:
- The basic principles of infectious diseases, including how pathogens infect hosts and cause disease.
- Different types of pathogens that cause infectious diseases such as bacteria, viruses, fungi, protozoa, and helminthes.
- The host defenses against infectious diseases, including both innate (nonspecific) defenses and adaptive (specific) defenses mediated by the immune system.
- Modes of transmission for infectious diseases, including direct contact, indirect contact, and vertical transmission from parent to child.
This document provides definitions and information related to infection and infection control in dentistry. It begins with definitions of key terms like infection, disease, virulence, and modes of transmission. It then discusses the normal flora of humans and stages of infection. Virulence factors and toxins are explained. The objectives and types of infection control are outlined, including universal precautions, routes of spread, and measures for pretreatment, chairside, and post-treatment infection control.
This document discusses host-microbe interactions and the sources of infection. It defines key terms like infection, infestation, pathogen, resistance, and susceptibility. It explains that microorganisms can have different relationships with hosts like parasitism, commensalism, and mutualism. Pathogens are microbes that can cause disease, while commensals do not affect the host. Sources of infection include humans, animals, insects, and the environment. Humans can transmit diseases as patients or carriers. Animals can transmit zoonotic diseases. Insects like mosquitoes transmit pathogens as mechanical or biological vectors. The environment, including soil, water, and food, can harbor microbes that cause infections.
This document discusses host-microbe relationships and microbial pathogenesis. It begins by defining key terms like pathogenicity, virulence, and toxigenicity. It then describes how most microbes do not cause harm, while a few contribute to health or pose threats. Pathogens can establish infections through various mechanisms like toxin production, tissue invasion, or evading host defenses. Toxins are categorized as exotoxins, endotoxins, or exoenzymes. Exotoxins like AB toxins directly damage tissues. Colonization, invasion, and evasion of host defenses allow pathogens to replicate and spread infection. Microbes cause disease through direct damage by toxins or indirect activation of the host immune response.
Infectious Disease by Gopal Khodve.pptxGOPAL KHODVE
Infectious diseases are disorders caused by organisms — such as bacteria, viruses, fungi or parasites. Many organisms live in and on our bodies. They're normally harmless or even helpful. But under certain conditions, some organisms may cause disease.
Some infectious diseases can be passed from person to person. Some are transmitted by insects or other animals. And you may get others by consuming contaminated food or water or being exposed to organisms in the environment.
Signs and symptoms vary depending on the organism causing the infection, but often include fever and fatigue. Mild infections may respond to rest and home remedies, while some life-threatening infections may need hospitalization.
Many infectious diseases, such as measles and chickenpox, can be prevented by vaccines. Frequent and thorough hand-washing also helps protect you from most infectious diseases.
What are infectious diseases?
Infectious diseases are illnesses caused by harmful organisms (pathogens) that get into your body from the outside. Pathogens that cause infectious diseases are viruses, bacteria, fungi, parasites and, rarely, prions. You can get infectious diseases from other people, bug bites and contaminated food, water or soil.
What’s the difference between infectious diseases and noninfectious diseases?
Infectious diseases are caused by harmful organisms that get into your body from the outside, like viruses and bacteria. Noninfectious diseases aren’t caused by outside organisms, but by genetics, anatomical differences, getting older and the environment you live in. You can’t get noninfectious diseases from other people, by getting a bug bite or from your food.
The flu, measles, HIV, strep throat, COVID-19 and salmonella are all examples of infectious diseases. Cancer, diabetes, congestive heart failure and Alzheimer’s disease are all examples of noninfectious diseases.
What are the types of infectious diseases?
Infectious diseases can be viral, bacterial, parasitic or fungal infections. There’s also a rare group of infectious diseases known as transmissible spongiform encephalopathies (TSEs).
Viral infections. Viruses are a piece of information (DNA or RNA) inside of a protective shell (capsid). Viruses are much smaller than your cells and have no way to reproduce on their own. They get inside your cells and use your cells’ machinery to make copies of themselves.
Bacterial infections. Bacteria are single-celled organisms with their instructions written on a small piece of DNA. Bacteria are all around us, including inside of our body and on our skin. Many bacteria are harmless or even helpful, but certain bacteria release toxins that can make you sick.
Fungal infections. Like bacteria, there are many different fungi. They live on and in your body. When your fungi get overgrown or when harmful fungi get into your body through your mouth, your nose or a cut in your skin, you can get sick.
Parasitic infections.
The document defines various terminologies related to microbial pathogenicity and infection. It discusses terms like saprophytes, parasites, commensals, pathogens, opportunistic pathogens, infection, colonization, infestation, and more. It also classifies infections based on factors like source, clinical manifestation, epidemiological patterns, and more. Finally, it covers various mechanisms of microbial pathogenicity like adhesion, invasiveness, toxins, inhibition of phagocytosis, and more.
This document provides an overview of microbe-human interactions related to infection and disease. It defines key terms like infection and disease and describes the resident microflora of the body. It also discusses true pathogens and opportunistic pathogens, as well as portals of entry, infectious dose, virulence factors, patterns of infection, signs and symptoms, and portals of exit. Finally, it covers topics in epidemiology like surveillance, prevalence, incidence, reservoirs of infection, modes of disease transmission, and nosocomial infections.
Classification of pathogenic and non pathogenic microorganisms-medical micro...Saajida Sultaana
This document discusses and compares pathogenic and non-pathogenic microorganisms. It notes that pathogenic microorganisms can cause disease, while non-pathogenic ones generally do not. It provides examples of bacteria and the diseases they cause. The document also discusses opportunistic pathogens that may cause infection when the immune system is compromised. Finally, it outlines some factors that determine the pathogenicity and virulence of different bacteria.
A disease is a particular abnormal condition, a disorder of a structure or function, that affects part or all of an organism. The study of disease is called pathology which includes the causal study of etiology. Disease is often construed as a medical condition associated with specific symptoms and signs.[1] It may be caused by external factors such as pathogens, or it may be caused by internal dysfunctions particularly of the immune system such as an immunodeficiency, or a hypersensitivity including allergies and autoimmunity.
The document discusses various common infectious diseases affecting humans including their causes, symptoms, treatment and prevention. It covers bacterial diseases like typhoid and pneumonia, viral diseases like common cold, fungal disease ringworm, parasitic diseases like malaria, amoebiasis, ascariasis and elephantiasis. It also discusses immune system, AIDS, cancer, commonly abused drugs and alcohol and their prevention. Overall, the document provides a comprehensive overview of major infectious diseases, their transmission, affected age groups and approach towards prevention and treatment.
This document provides information about an ELISA Immuno Explorer kit for diagnosing influenza. It discusses how the kit works, the process and results of performing a rapid influenza diagnostic test using ELISA. Key points include:
- The kit allows students to perform an ELISA in 45 minutes to diagnose influenza using controls and samples.
- A rapid influenza diagnostic test is an ELISA that can detect viral antigens in a doctor's office within 30 minutes and distinguish influenza types A and B.
- Performing the ELISA involves adding controls and samples to wells, washing, then adding detection antibodies and substrate to produce a color change indicating positive or negative results.
This document discusses soil microbial ecology and the role of microorganisms in soil. It notes that different microhabitats in soil favor different indigenous microbial populations. Soil particles provide microenvironments with decreasing oxygen levels from the surface. Indigenous soil microflora are determined by abiotic soil factors and some have adaptive structures like endospores. Soil microorganisms play important roles in biodegradation, mineral cycling like nitrogen fixation, and biogeochemical cycles.
Microbial genetics and genetic engineeringLani Manahan
1. Recombinant DNA technology involves splicing together DNA fragments from different organisms using restriction enzymes and ligase.
2. Vectors are used to insert the recombinant DNA into host cells where they can be replicated. Common vectors include plasmids and bacteriophages.
3. Successful recombinants are selected by their ability to grow in the presence of antibiotics or be detected through other methods like hybridization.
This document discusses several genetic elements and processes in bacteria, including:
1) Genetic elements like plasmids that can carry antibiotic resistance or aid in catabolism.
2) Mechanisms of genetic variation like mutation, transduction via bacteriophage, and recombination through conjugation.
3) Details are provided on specific types of mutations like base substitutions and frameshifts, as well as methods of selection.
This document discusses several genetic elements and processes in bacteria, including:
1) Genetic elements like plasmids that can encode traits like antibiotic resistance and be transferred between bacteria.
2) Mechanisms of genetic variation like mutation, genetic recombination through conjugation, transduction by bacteriophages, and transposition of mobile genetic elements.
3) The processes of replication, transcription, and translation that underlie gene expression and flow of genetic information.
The document summarizes various chemical and antibiotic agents used to control microbes. It discusses phenolics, alcohols, halogens, heavy metals, quaternary ammonium compounds and aldehydes as chemical agents and their mechanisms of action. It also discusses different classes of antibiotics like penicillins and their mechanisms of action. Resistance to these agents can develop due to physiological changes in bacteria like efflux pumps or enzymatic inactivation. The spread of antibiotic resistant bacteria is a growing concern as resistance increases in hospitals and farms with extensive antibiotic use.
The document discusses microbial control through various physical and chemical methods. It begins with a brief history of bubonic plague in Europe during the Middle Ages caused by the Yersinia pestis bacterium. It then defines key terms like sterilization, disinfection, bactericidal and bacteriostatic. The document outlines several conditions that influence the effectiveness of antimicrobial agents and describes various physical methods of microbial control including heat, filtration and radiation. It provides details on how these methods kill microbes and examples of their applications.
This document summarizes key stages in embryonic development:
1) Fertilization, cleavage, gastrulation, neurulation and organogenesis are the main developmental stages described.
2) During cleavage, the fertilized egg undergoes rapid cell divisions without growth. Gastrulation involves the invagination and involution of cells to form the three germ layers.
3) Neurulation involves the formation of the neural plate which curves inward to form the neural tube from ectoderm. Mesoderm forms blocks called somites during development.
HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
Let's Integrate MuleSoft RPA, COMPOSER, APM with AWS IDP along with Slackshyamraj55
Discover the seamless integration of RPA (Robotic Process Automation), COMPOSER, and APM with AWS IDP enhanced with Slack notifications. Explore how these technologies converge to streamline workflows, optimize performance, and ensure secure access, all while leveraging the power of AWS IDP and real-time communication via Slack notifications.
Programming Foundation Models with DSPy - Meetup SlidesZilliz
Prompting language models is hard, while programming language models is easy. In this talk, I will discuss the state-of-the-art framework DSPy for programming foundation models with its powerful optimizers and runtime constraint system.
Unlock the Future of Search with MongoDB Atlas_ Vector Search Unleashed.pdfMalak Abu Hammad
Discover how MongoDB Atlas and vector search technology can revolutionize your application's search capabilities. This comprehensive presentation covers:
* What is Vector Search?
* Importance and benefits of vector search
* Practical use cases across various industries
* Step-by-step implementation guide
* Live demos with code snippets
* Enhancing LLM capabilities with vector search
* Best practices and optimization strategies
Perfect for developers, AI enthusiasts, and tech leaders. Learn how to leverage MongoDB Atlas to deliver highly relevant, context-aware search results, transforming your data retrieval process. Stay ahead in tech innovation and maximize the potential of your applications.
#MongoDB #VectorSearch #AI #SemanticSearch #TechInnovation #DataScience #LLM #MachineLearning #SearchTechnology
Your One-Stop Shop for Python Success: Top 10 US Python Development Providersakankshawande
Simplify your search for a reliable Python development partner! This list presents the top 10 trusted US providers offering comprehensive Python development services, ensuring your project's success from conception to completion.
Taking AI to the Next Level in Manufacturing.pdfssuserfac0301
Read Taking AI to the Next Level in Manufacturing to gain insights on AI adoption in the manufacturing industry, such as:
1. How quickly AI is being implemented in manufacturing.
2. Which barriers stand in the way of AI adoption.
3. How data quality and governance form the backbone of AI.
4. Organizational processes and structures that may inhibit effective AI adoption.
6. Ideas and approaches to help build your organization's AI strategy.
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und überflüssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
Have you ever been confused by the myriad of choices offered by AWS for hosting a website or an API?
Lambda, Elastic Beanstalk, Lightsail, Amplify, S3 (and more!) can each host websites + APIs. But which one should we choose?
Which one is cheapest? Which one is fastest? Which one will scale to meet our needs?
Join me in this session as we dive into each AWS hosting service to determine which one is best for your scenario and explain why!
Ivanti’s Patch Tuesday breakdown goes beyond patching your applications and brings you the intelligence and guidance needed to prioritize where to focus your attention first. Catch early analysis on our Ivanti blog, then join industry expert Chris Goettl for the Patch Tuesday Webinar Event. There we’ll do a deep dive into each of the bulletins and give guidance on the risks associated with the newly-identified vulnerabilities.
Nunit vs XUnit vs MSTest Differences Between These Unit Testing Frameworks.pdfflufftailshop
When it comes to unit testing in the .NET ecosystem, developers have a wide range of options available. Among the most popular choices are NUnit, XUnit, and MSTest. These unit testing frameworks provide essential tools and features to help ensure the quality and reliability of code. However, understanding the differences between these frameworks is crucial for selecting the most suitable one for your projects.
Generating privacy-protected synthetic data using Secludy and MilvusZilliz
During this demo, the founders of Secludy will demonstrate how their system utilizes Milvus to store and manipulate embeddings for generating privacy-protected synthetic data. Their approach not only maintains the confidentiality of the original data but also enhances the utility and scalability of LLMs under privacy constraints. Attendees, including machine learning engineers, data scientists, and data managers, will witness first-hand how Secludy's integration with Milvus empowers organizations to harness the power of LLMs securely and efficiently.
Ocean lotus Threat actors project by John Sitima 2024 (1).pptxSitimaJohn
Ocean Lotus cyber threat actors represent a sophisticated, persistent, and politically motivated group that poses a significant risk to organizations and individuals in the Southeast Asian region. Their continuous evolution and adaptability underscore the need for robust cybersecurity measures and international cooperation to identify and mitigate the threats posed by such advanced persistent threat groups.
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
Digital Marketing Trends in 2024 | Guide for Staying AheadWask
https://www.wask.co/ebooks/digital-marketing-trends-in-2024
Feeling lost in the digital marketing whirlwind of 2024? Technology is changing, consumer habits are evolving, and staying ahead of the curve feels like a never-ending pursuit. This e-book is your compass. Dive into actionable insights to handle the complexities of modern marketing. From hyper-personalization to the power of user-generated content, learn how to build long-term relationships with your audience and unlock the secrets to success in the ever-shifting digital landscape.
leewayhertz.com-AI in predictive maintenance Use cases technologies benefits ...alexjohnson7307
Predictive maintenance is a proactive approach that anticipates equipment failures before they happen. At the forefront of this innovative strategy is Artificial Intelligence (AI), which brings unprecedented precision and efficiency. AI in predictive maintenance is transforming industries by reducing downtime, minimizing costs, and enhancing productivity.
Salesforce Integration for Bonterra Impact Management (fka Social Solutions A...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on integration of Salesforce with Bonterra Impact Management.
Interested in deploying an integration with Salesforce for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
In the fifth annual Global Privacy Benchmarks Survey, we asked over 1,800 global privacy professionals and business executives to share their perspectives on the current state of privacy inside and outside of their organizations. This year’s report focused on emerging areas of importance for privacy and compliance professionals, including considerations and implications of Artificial Intelligence (AI) technologies, building brand trust, and different approaches for achieving higher privacy competence scores.
See how organizational priorities and strategic approaches to data security and privacy are evolving around the globe.
This webinar will review:
- The top 10 privacy insights from the fifth annual Global Privacy Benchmarks Survey
- The top challenges for privacy leaders, practitioners, and organizations in 2024
- Key themes to consider in developing and maintaining your privacy program
2. LECTURE CONTENTS
1. Types of interaction
– Interaction with other
microbes
– Interaction with plants
– Interaction with
animals
– Interaction with human
2. Microbes and Disease
3. Microbes and the
Environment
5. • Lichen symbiosis
– Lichens are associations of
fungus (host) with
photosynthetic alga or
cyanobacteria (symbiont).
– Fungus (ectosymbiont) provides
minerals by releasing lichen
acids that dissolve
substrate, release small amounts
of P, S, other minerals, and
obtains water from air.
– The endosymbiont carries out
photosynthesis, converts CO2 to
organic matter to feed itself and
fungus host.
– Resulting symbiotic organisms
can grow attached to rocks, tree
trunks, other unlikely habitats
7. Plant pathogens
F graminearum causes
a disease know as ear Tobacco mosaic virus
and stalk rot in corn and
Xanthomonas head blight in wheat
Gram-negative, yellow- and barley
pigmented plant
pathogenic bacteria
8. • Symbiotic Nitrogen Fixation
– symbiosis between bacteria (Rhizobium
species) and roots of leguminous plants
(alfalfa, clover, vetch, peas, beans, etc.) -->
root nodules
– Bacteria provide ammonia by nitrogen
fixation. Plants provide nutrients and
shelter and anaerobic microenvironments
– Allows growth in nitrogen-poor soils
– Note: there are non-symbiotic nitrogen-
fixing bacteria, e.g. Azotobacter. Also
other types of symbionts, e.g. Frankia that
live in Alder roots, create nodules.
11. • Ruminants & Resident microbes
– Ruminants (R) are herbivorous animals with four-chambered stomach =
rumen.
– R eat grasses containing mainly cellulose, but lack enzymes to digest cellulose.
– Bacteria and Protists in rumen produce cellulases, hydrolyze cellulose to sugar
which is then fermented.
– Products include: methane (from methanogens); organic acids
(acetate, propionate, butyrate).
– Acids are adsorbed by R into bloodstream, provide source of energy.
– Methane must be released by belching, ~2 liters/min. Disease "bloat" when
cows can't belch.
– Microbial population totally anaerobic, achieves highest density of bacteria
(up to 1012 cells/ml).
– Cellulose digestion is slow process. Animals regurgitate rumen contents back
to mouth to facilitate breakdown, "chewing cud".
14. Normal Microbiota and the Host:
• Locations of normal
microbiota on and in
the human body
15. Normal Microbiota and the Host
• Transient microbiota may be present for
days, weeks, or months
• Normal microbiota permanently colonize the
host
• Symbiosis is the relationship between normal
microbiota and the host
16. Normal Microbiota and the Host:
• Microbial antagonism is competition between
microbes.
• Normal microbiota protect the host by:
– occupying niches that pathogens might occupy
– producing acids
– producing bacteriocins
• Probiotics are live microbes applied to or
ingested into the body, intended to exert a
beneficial effect.
17. Principles of Disease and
Epidemiology
• Pathology Study of disease
• Etiology Study of the cause of a disease
• Pathogenesis Development of disease
• Infection Colonization of the body by
pathogens
• Disease An abnormal state in which the
body is not functionally normally
19. Koch’s Postulates
• Koch's Postulates are
used to prove the cause
of an infectious disease.
Figure 14.3.2
20. Classifying Infectious Diseases
• Symptom A change in body function that is
felt by a patient as a result of
disease
• Sign A change in a body that can be
measured or observed as a result
of disease.
• Syndrome A specific group of signs and
symptoms that accompany a
disease.
21. Classifying Infectious Diseases
• Communicable disease
– A disease that is easily spread from one host to
another.
• Contagious disease
– A disease that is easily spread from one host to
another.
• Non-communicable disease
– A disease that is not transmitted from one host to
another.
22. Occurrence of Disease
• Incidence Fraction of a population that
contracts a disease during a
specific time.
• Prevalence Fraction of a population having
a specific disease at a given time.
• Sporadic disease Disease that occurs
occasionally in a population.
• Endemic disease Disease constantly present in a
population.
• Epidemic disease Disease acquired by many
hosts in a given area in a short
time.
• Pandemic disease Worldwide epidemic.
• Herd immunity Immunity of a population.
23. Severity or Duration of a Disease
• Acute disease Symptoms develop rapidly
• Chronic disease Disease develops slowly
• Subacute disease Symptoms between acute
and chronic
• Latent disease Disease with a period of
no symptoms
24. Extent of Host Involvement
• Local infection Pathogens limited to a small
area of the body
• Systemic infection An infection throughout the
body
• Focal infection Systemic infection that began
as a local infection
• Bacteremia Bacteria in the blood
• Septicemia Growth of bacteria in the blood
25. Extent of Host Involvement
• Toxemia Toxins in the blood
• Viremia Viruses in the blood
• Primary infection Acute infection that causes the
initial illness
• Secondary infection Opportunistic infection
after a primary (predisposing)
infection
• Subclinical disease No noticeable signs or symptoms
(inapparent infection)
26. Predisposing Factors
• Make the body more susceptible to disease
– Short urethra in females
– Inherited traits such as the sickle-cell gene
– Climate and weather
– Fatigue
– Age
– Lifestyle
– Chemotherapy
28. Reservoirs of Infection
• Reservoirs of infection are continual sources
of infection.
– Human — AIDS, gonorrhea
• Carriers may have inapparent infections or latent
diseases
– Animal — Rabies, Lyme disease
• Some zoonoses may be transmitted to humans
– Nonliving — Botulism, tetanus
• Soil
29.
30. Transmission of Disease
1. Contact
– Direct
• Requires close association
between infected and
susceptible host
– Indirect
• Spread by fomites
– Droplet
• Transmission via airborne
droplets
31. Transmission of Disease
2. Vehicle
Transmission by an inanimate
reservoir (food, water)
3. Vectors
Arthropods, especially
fleas, ticks, and mosquitoes
4. Mechanical
Arthropod carries pathogen on
feet
5. Biological
Pathogen reproduces in vector
32. Nosocomial (Hospital-Acquired)
Infections
• Are acquired as a result of a hospital stay
• 5-15% of all hospital patients acquire
nosocomial infections
35. Common Causes of Nosocomial
Infections
Percentage of Percentage resistant to
nosocomial infections antibiotics
Gram + cocci 34% 28%-87%
Gram – rods 32% 3-34%
Clostridium difficile 17%
Fungi 10%
36. Emerging Infectious Diseases
• Diseases that are new, increasing in incidence, or
showing a potential to increase in the near
future.
• Contributing factors:
– Evolution of new strains
• V. cholerae O139
– Inappropriate use of antibiotics and pesticides
• Antibiotic resistant strains
– Changes in weather patterns
• Hantavirus
37. Emerging Infectious Diseases
• Contributing factors:
– Modern transportation
• West Nile virus
– Ecological disaster, war, expanding human settlement
• Coccidioidomycosis (Coccidioides immitis )
– Animal control measures
• Lyme disease
– Public Health failure
• Diphtheria (Corynebacterium diphtheriae)
39. Centers for Disease Control and
Prevention (CDC)
• Collects and analyzes epidemiological information in
the U.S.
• Publishes Morbidity and Mortality Weekly Report
(MMWR) www.cdc.gov
• Morbidity: incidence of a specific notifiable disease
• Mortality: deaths from notifiable diseases
• Morbidity rate = number of people affected/total
population in a given time period
• Mortality rate - number of deaths from a disease/total
population in a given time
40. Microbial Mechanisms of
Pathogenicity
• Pathogenicity The ability to cause
disease
• Virulence The extent of
pathogenicity
42. Numbers of Invading Microbes
• ID50: Infectious dose for 50% of the test
population
• LD50: Lethal dose (of a toxin) for 50% of the
test population
44. Adherence
• Adhesions/ligands bind to receptors on host
cells
– Glycocalyx Streptococcus mutans
– Fimbriae Escherichia coli
– M protein Streptococcus pyogenes
– Opa protein Neisseria gonorrhoeae
– Tapered end Treponema pallidum
45. Mechanisms to cause disease
Enzymes
– Coagulase Coagulate blood
– Kinases Digest fibrin clots
– Hyaluronidase Hydrolyses hyaluronic acid
– Collagenase Hydrolyzes collagen
– IgA proteases Destroy IgA antibodies
Siderophores Take iron from host
iron-binding proteins
Antigenic variation Alter surface proteins
Toxins Production of toxins
(endotoxin; exotoxin)
46. Toxins
• Toxin Substances that contribute to
pathogenicity
• Toxigenicity Ability to produce a toxin
• Toxemia Presence of toxin the host's
blood
• Toxoid Inactivated toxin used in a
vaccine
• Antitoxin Antibodies against a specific
toxin
47.
48. Exotoxin
Source Mostly Gram +
Metabolic product By-products of growing cell
Chemistry Protein
Fever? No
Neutralized by antitoxin Yes
LD50 Small
49. Exotoxins
• Superantigens or type I toxins
– Cause an intense immune response due to release
of cytokines from host cells
– Fever, nausea, vomiting, diarrhea, shock, death
• Membrane-disrupting toxins or type II toxins
– Lyse host’s cells by:
• Making protein channels in the plasma membrane
(e.g., leukocidins, hemolysins)
• Disrupting phospholipid bilayer
52. Endotoxins
Source Gram–
Metabolic product Present in LPS of outer membrane
Chemistry Lipid
Fever? Yes
Neutralized by antitoxin No
LD50 Relatively large
58. Pathogenic Properties of Protozoa
• Presence of protozoa
• Protozoan waste products may cause
symptoms
• Avoid host defenses by
– Growing in phagocytes
– Antigenic variation
59. Pathogenic Properties of Helminths
• Use host tissue
• Presence of parasite interferes with host
function
• Parasite's metabolic waste can cause
symptoms
60. Pathogenic Properties of Algae
• Neurotoxins produced by dinoflagellates
– Saxitoxin
• Paralytic shellfish poisoning