Normal flora is the term used to describe the various bacteria and fungi that are permanent residents of certain
body sites, especially the skin, oropharynx, colon, and
vagina (Tables 6–1 and 6–2). Viruses and parasites (protozoa
and helminths), which are the other major groups of
microorganisms, are usually not considered members of
the normal flora, although they can be present in asymptomatic individuals. The normal flora organisms are often
referred to as commensals. Commensals are organisms
that derive benefit from another host but do not damage
that host. The term human microbiome is often used to
describe the normal flora.
The members of the normal flora play a role both in the
maintenance of health and in the causation of disease in
three significant ways:
(1) They can cause disease, especially in immunocompromised and debilitated individuals. Although these
organisms are nonpathogens in their usual anatomic location, they can be pathogens in other parts of the body.
(2) They constitute a protective host defense mechanism.
The nonpathogenic resident bacteria occupy attachment
sites on the skin and mucosa that can interfere with colonization by pathogenic bacteria. The ability of members of the
normal flora to limit the growth of pathogens is called colonization resistance. If the normal flora is suppressed, pathogens may grow and cause disease. For example, antibiotics
can reduce the normal colonic flora that allows Clostridium
difficile, which is resistant to the antibiotics, to overgrow and
cause pseudomembranous colitis.
(3) They may serve a nutritional function. The intestinal bacteria produce several B vitamins and vitamin K.
Poorly nourished people who are treated with oral antibiotics can have vitamin deficiencies as a result of the reduction in the normal flora. However, since germ-free animals
are well-nourished, the normal flora is not essential for
proper nutrition.
THE HUMAN MICROBIOME
The human microbiome is the term used to describe the
thousands of microbes (“microbiota”) located on the skin,
on mucosal surfaces, and within the lumen of the
TABLE 6–2 Medically Important Members of the Normal Flora
Location Important Organisms1 Less Important Organisms2
Skin Staphylococcus epidermidis Staphylococcus aureus, Corynebacterium (diphtheroids), various streptococci,
Pseudomonas aeruginosa, anaerobes (e.g., Propionibacterium), yeasts (e.g.,
Candida albicans)
Nose S. aureus3 S. epidermidis, Corynebacterium (diphtheroids), various streptococci
Mouth Viridans streptococci Various streptococci, Eikenella corrodens
Dental plaque Streptococcus mutans Prevotella intermedia, Porphyromonas gingivalis
Gingival crevices Various anaerobes (e.g.,
Bacteroides, Fusobacterium,
streptococci, Actinomyces)
Throat Viridans streptococci Various streptococci (including Streptococcus pyogenes and Streptococcus
pneumoniae), Neisseria species, Haemophilus influenzae, S. epidermidis
Colon Bacteroides fragilis, Escherichia
Normal flora is the term used to describe the various bacteria and fungi that are permanent residents of certain
body sites, especially the skin, oropharynx, colon, and
vagina (Tables 6–1 and 6–2). Viruses and parasites (protozoa
and helminths), which are the other major groups of
microorganisms, are usually not considered members of
the normal flora, although they can be present in asymptomatic individuals. The normal flora organisms are often
referred to as commensals. Commensals are organisms
that derive benefit from another host but do not damage
that host. The term human microbiome is often used to
describe the normal flora.
The members of the normal flora play a role both in the
maintenance of health and in the causation of disease in
three significant ways:
(1) They can cause disease, especially in immunocompromised and debilitated individuals. Although these
organisms are nonpathogens in their usual anatomic location, they can be pathogens in other parts of the body.
(2) They constitute a protective host defense mechanism.
The nonpathogenic resident bacteria occupy attachment
sites on the skin and mucosa that can interfere with colonization by pathogenic bacteria. The ability of members of the
normal flora to limit the growth of pathogens is called colonization resistance. If the normal flora is suppressed, pathogens may grow and cause disease. For example, antibiotics
can reduce the normal colonic flora that allows Clostridium
difficile, which is resistant to the antibiotics, to overgrow and
cause pseudomembranous colitis.
(3) They may serve a nutritional function. The intestinal bacteria produce several B vitamins and vitamin K.
Poorly nourished people who are treated with oral antibiotics can have vitamin deficiencies as a result of the reduction in the normal flora. However, since germ-free animals
are well-nourished, the normal flora is not essential for
proper nutrition.
THE HUMAN MICROBIOME
The human microbiome is the term used to describe the
thousands of microbes (“microbiota”) located on the skin,
on mucosal surfaces, and within the lumen of the
TABLE 6–2 Medically Important Members of the Normal Flora
Location Important Organisms1 Less Important Organisms2
Skin Staphylococcus epidermidis Staphylococcus aureus, Corynebacterium (diphtheroids), various streptococci,
Pseudomonas aeruginosa, anaerobes (e.g., Propionibacterium), yeasts (e.g.,
Candida albicans)
Nose S. aureus3 S. epidermidis, Corynebacterium (diphtheroids), various streptococci
Mouth Viridans streptococci Various streptococci, Eikenella corrodens
Dental plaque Streptococcus mutans Prevotella intermedia, Porphyromonas gingivalis
Gingival crevices Various anaerobes (e.g.,
Bacteroides, Fusobacterium,
streptococci, Actinomyces)
Throat Viridans streptococci Various streptococci (including Streptococcus pyogenes and Streptococcus
pneumoniae), Neisseria species, Haemophilus influenzae, S. epidermidis
Colon Bacteroides fragilis, Escherichia
Normal flora , microbiology includes the normal flora present in inside the environment and outside the environment and also bacterias etc
Normal flora , microbiology includes the normal flora present in inside the environment and outside the environment and also bacterias etc
The human microbiome is the aggregate of all microbiota that reside on or within human tissues and biofluids along with the corresponding anatomical sites in which they reside, including the skin, mammary glands, placenta, seminal fluid, uterus, ovarian follicles, lung, saliva, oral mucosa, conjunctiva, biliary tract, etc
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Types of Normal flora
Association between human and normal flora .
Characteristics of normal flora
Tissue specificity
Specific aadherence
Biofilm formation
Normal flora of skin
Normal flora of oral cavity
Normal flora of conjunctiva
Normal flora of respiratory tract
Normal flora of gastro intestinal tract
Normal flora of urogenital tract
Beneficial effect of normal flora
Harmful effect of normal flora
Disease caused by normal flora
Oral microbial flora final /certified fixed orthodontic courses by Indian den...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
Follow us on: Pinterest
Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Normal flora , microbiology includes the normal flora present in inside the environment and outside the environment and also bacterias etc
Normal flora , microbiology includes the normal flora present in inside the environment and outside the environment and also bacterias etc
The human microbiome is the aggregate of all microbiota that reside on or within human tissues and biofluids along with the corresponding anatomical sites in which they reside, including the skin, mammary glands, placenta, seminal fluid, uterus, ovarian follicles, lung, saliva, oral mucosa, conjunctiva, biliary tract, etc
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Types of Normal flora
Association between human and normal flora .
Characteristics of normal flora
Tissue specificity
Specific aadherence
Biofilm formation
Normal flora of skin
Normal flora of oral cavity
Normal flora of conjunctiva
Normal flora of respiratory tract
Normal flora of gastro intestinal tract
Normal flora of urogenital tract
Beneficial effect of normal flora
Harmful effect of normal flora
Disease caused by normal flora
Oral microbial flora final /certified fixed orthodontic courses by Indian den...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
Follow us on: Pinterest
Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
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ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
2. is the term used to describe the various bacteria and fungi that
are permanent residents of certain body sites
The viruses and parasites, which are the two other major groups of
microorganisms, are usually not considered members of the normal flora,
although they can be present in asymptomatic individuals.
The members of the normal flora vary in both number and kind from one site to
another.
Normal flora organisms inhabit the body surfaces exposed to the environment,
such as the skin, oropharynx, intestinal tract, and vagina. Members of the
normal flora differ in number and kind at various anatomic sites
3. the internal organs usually are sterile areas such as the
central nervous system, blood, lower bronchi and alveoli,
liver, spleen, kidneys, and bladder are free of all but the
occasional transient organism.
• Members of the normal flora are low-virulence organisms. In
their usual anatomic site, they are nonpathogenic. However, if they
leave their usual anatomic site, especially in an
immunocompromised individual, they can cause disease.
• Colonization resistance occurs when members of the
normal flora occupy receptor sites on the skin and mucosal
surfaces, thereby preventing pathogens from binding to those
receptors.
4. Sterile (Microbe-Free) Anatomical Sites
and Fluids
Sites That Harbor Normal Resident
Microbes
All Internal Tissues and Organs
Heart and circulatory system Bones
Liver Ovaries/testes
Kidneys and bladder Glands (pancreas,
salivary)
Lungs Sinuses
Brain and spinal cord Middle and inner ear
Muscles Internal eye
Fluids Within an Organ or Tissue
Blood
Urine in kidneys, ureters, bladder
Cerebrospinal fluid
Saliva prior to entering the oral cavity
Semen prior to entering the urethra
Amniotic fluid surrounding the embryo and fetus
• Skin and its contiguous mucous membranes
• Upper respiratory tract (oral cavity, pharynx, nasal
mucosa)
• Gastrointestinal tract (mouth, colon, rectum, anus)
• Outer opening of urethra
• External genitalia
• Vagina
• External ear and canal
• External eye (lids, lash follicles)
5. Resident NF – consists of relatively fixed types of microorganisms
regularly found in a given area at a given age; if disturbed, it promptly
reestablishes itself.
Transient NF –consists of nonpathogenic or potentially pathogenic
microorganisms that inhabit the skin or mucous membranes for hours,
days, or weeks; it is derived from the environment, does not produce
disease, and does not establish itself permanently on the surface.
7. Healthy fetus, in utero, is essentially free of MOs
Infant exposed immediately to MOs when passing
through mothers vaginal tract and then to MOs in
environment
Within few hours, oral and nasopharyngeal flora of
neonate established
Within one day, resident flora of lower intestinal tract
established
8. Protection from External Invaders
a) Because of the normal flora occupy body's epithelial surfaces, they are able to prevent other bacteria by
blocking receptors
b) competing for essential nutrients
c) producing anti-bacteria substances e.g : Fatty acids, peroxides , Bacteriocins
May be source of opportunistic infections
e.g : In Patients with impaired defense Mechanisms
Immunostimulation
a) They produce antibodies which may contribute to host defenses.
b) Some of these antibodies may cross react with normal tissue components.
Nutrition Some of the normal intestinal flora e.g. E. coli & Bacteroids produce Vitamin K in the gut
9. Important Members of the Normal Flora
Skin. The predominant member of the normal flora
of the skin is Staphylococcus epidermidis. It is
an important cause of infections of prosthetic heart
valves and prosthetic joints.
Candidia albicans, a yeast also found on the
skin, can enter the bloodstream and cause
disseminated infections, such as endocarditis in
intravenous drug users. S. aureus is also present
on the skin, but its main site is in the nose. It
causes abscesses in the skin and in many other
organs.
10. Oropharynx. The main members
of the normal flora of the mouth and
throat are the viridans
streptococci, such as S. sanguis
and S. mutans . Viridans
streptococci are the most common
cause of subacute endocarditis.
11. Examples of bacteria
that inhabit the
gastrointestinal tract.
Gastrointestinal tract. The stomach contains very few organisms
because of the low pH. The colon containsthe largest number of
normal flora and the most diverse species, including both anaerobic and
facultative bacteria. There are both gram-positive and gram-negative rods
and cocci.
The members of the colonic normal flora are an important cause of disease
outside of the colon. The two most important members of the colonic flora
that cause disease are the anaerobe Bacteroides fragilis and the
facultative Escherichia coli. Enterococcus faecalis, a facultative, is
also a very important pathogen.
12. Vagina. Lactobacilli are the
predominant normal flora organisms
in the vagina.They keep the pH of
the vagina low, which inhibits the
growth of organisms such as C.
albicans, an important cause of
vaginitis.
Urethra. The outer third of the
urethra contains a mixture of
bacteria, primarily S. epidermidis .
The female urethra can become
colonized with fecal flora such as E.
coli , which predisposes to urinary
tract infections.
13. Associations between microbes
and humans. Effects of contact
with microbes can progress in a
variety of directions, ranging from
no effect to colonization, and from
infection to disease and immunity.
The example shown here follows the
possible events in the case of contact
with a pathogen such as
Streptococcus pneumoniae (the
pneumococcus). This bacterium can
be harbored harmlessly in the upper
respiratory tract, but it may also
invade and infect the ear, cranium,
and respiratory tract.
14. •The two main ways in which an
individual will encounter a pathogen
are:
where the
normal microbiota can multiply and
develop due to a disruption of normal
defences
result when
infecting bacteria have been acquired
from an external source and is not part
of the natural microbiota
15.
16.
17. – Invasion
• e.g. Strep pyogenes pharyngitis
– Migration
• e.g. Escherichia coli urinary tract infection
– Innoculation
• e.g. Coagulase negative staphylococcus prosthetic
joint infection
– Haematogenous
• e.g. viridans Strep endocarditis
18. What is a surface?
Interface between a solid and either a liquid or gas.
Patient
Pathogen
Infection Management Outcome
Mechanism of infection
epithelium
hair
nails
conjunctiv
al
gastrointestinal
respiratory
genitourinary
27. Processes in the pathogenesis of infection at
surfaces
• Adherence to host cells or prosthetic
surface
• Biofilm formation
• Invasion and multiplication
• Host response
– Pyogenic (neutrophils -> pus)
– Granulomatous (fibroblasts, lymphocytes,
macrophages -> nodular inflammatory
28. What is Biofilm
Biofilms are multicellular aggregates of bacteria and
yeast that congregate on surfaces.
Biofilm formation is a nearly universal bacterial trait,
and biofilms are found on almost all natural and
artificial surfaces
Biofilms are formed to protect the bacteria from host
defenses, antibiotics, and from harsh environmental
conditions.
Some examples of biofilms are the plaque that forms
on teeth and the slime that forms on surfaces in
watery areas
29. A process that enables bacteria to
communicate using secreted signaling
molecules called auto inducers
This process enables a population of
bacteria to regulate gene expression
collectively and therefore, control
behavior on a community-wide scale.
30. Quorum Sensing helps
in
Bacteria use Quorum sensing to
mastermind behaviors or
(Controls)
– Sporulation
– Biofilm formation
– Virulence factor secretion
55*pp0
31. Three principles steps
1) production of small biochemical signal molecules by the bacterial cell.
2) release of the signal molecules, either actively or passively, into the
surrounding environment
3) recognition of the signal molecules by specific receptors once they
exceed a threshold concentration, leading to Gene expression ->co-
operative behaviours and more AI production.
32. Diagnosis
• Aim is to identify infecting organism and its antimicrobial
susceptibilities.
• Blood cultures
• Tissue/prosthetic material sonication and culture
• Treatment
• Aim:
– sterilise tissue
– reduce bioburden
• Antibacterials
• Remove prosthetic material
• Surgery – resect infected material
35. • Natural and prosthetic surfaces are frequent sites of
infection
• Biofilms are a common feature of surface infections
• Bacteria are protected from host and antibacterial attack
by biofilms.