The document summarizes research on how environmental stresses impact the pathogenicity of Listeria monocytogenes. It discusses how L. monocytogenes is able to withstand stresses like salt, low temperatures, and pH levels. The research found that in response to salt stress, L. monocytogenes both represses and induces various proteins. General stress proteins and osmolyte transporters were among those induced to help the bacteria adapt. Signal transduction and surface proteins also help L. monocytogenes interact with and survive in changing environmental conditions. The conclusion discusses how a better understanding of these response mechanisms could help develop techniques to control the pathogen in food processing.
The current study investigated the immunomodulatory
potential of ethyl acetate soluble supernatant of
Lactobacillus casei (LC-EAS) in vitro. The effect of
LC-EAS on nitric oxide release was analyzed in RAW
264.7 cells, wherein, an inhibition in nitric oxide production
through suppression of inducible nitric oxide synthase
mRNA expression was observed. Evaluation of LC-EAS
on LPS-induced peripheral blood mononuclear cells
showed a down-regulation in TNF-a and IL-6 genes and an
upregulation of IL-10. An inhibition in the protein
expression of NF-kB, ERK1/2 and STAT3 phosphorylation
confirms the immunomodulatory potential of LC-EAS. The
effect of LC-EAS on in vitro intestinal epithelial cells was
investigated using HT-29 human colon adenocarcinoma
cancer cells. LC-EAS exhibited an inhibition of NF-jB and
ERK1/2 phosphorylation, whereas STAT3 phosphorylation
was unregulated. To evaluate the downstream target of
STAT3 upregulation, expression of the intestinal trefoil
factor TFF3 which is a NF-jB regulator and STAT3
downstream target was studied. LC-EAS was observed to
elevate TFF3 mRNA expression. Overall the study shows
that the anti-inflammatory potential of LC-EAS is through
inhibition of NF-kB in different cell types.
The current study investigated the immunomodulatory
potential of ethyl acetate soluble supernatant of
Lactobacillus casei (LC-EAS) in vitro. The effect of
LC-EAS on nitric oxide release was analyzed in RAW
264.7 cells, wherein, an inhibition in nitric oxide production
through suppression of inducible nitric oxide synthase
mRNA expression was observed. Evaluation of LC-EAS
on LPS-induced peripheral blood mononuclear cells
showed a down-regulation in TNF-a and IL-6 genes and an
upregulation of IL-10. An inhibition in the protein
expression of NF-kB, ERK1/2 and STAT3 phosphorylation
confirms the immunomodulatory potential of LC-EAS. The
effect of LC-EAS on in vitro intestinal epithelial cells was
investigated using HT-29 human colon adenocarcinoma
cancer cells. LC-EAS exhibited an inhibition of NF-jB and
ERK1/2 phosphorylation, whereas STAT3 phosphorylation
was unregulated. To evaluate the downstream target of
STAT3 upregulation, expression of the intestinal trefoil
factor TFF3 which is a NF-jB regulator and STAT3
downstream target was studied. LC-EAS was observed to
elevate TFF3 mRNA expression. Overall the study shows
that the anti-inflammatory potential of LC-EAS is through
inhibition of NF-kB in different cell types.
Alteration in Protein Metabolic Profiles in Liver Tissue of Rats during Dimet...iosrjce
Dimethoate is the widely used organophosphorous insecticides in agriculture. The irrational use of
Dimethoate in Yemen play a crucial role in the occurrence of many diseases affecting plants, animals and man.
Dimethoate (DM) is used to kill mites and aphids among other insects and is applied on citrus, cotton, fruit,
olives, potatoes, tea, tobacco and vegetables. The aim of the present work was to study biochemical changes
that might occur in the liver of albino rats as a result of DM intoxication. In the present investigation the
animals were treated with 1/10th of LD50 of DM via oral gavage (34.5mg/kg body weight. The first group
animals were considered as control animals. Second group of animals were treated with Dimethoate via oral
gavage (34.5mg/kg body weight which is 1/10th of LD50) for 10 days, third and fourth groups of animals were
administered for 20 and 30 days with an interval of 48h respectively. The DM treated groups are AST and ALT
was selected in the present investigation showed an increment. The present findings indicate that chronic
exposure to DM has clear toxic effect on the liver of albino rats.
phytoecdysteroids affect the larval pupal and adult growth and developements of insects. it affects the digestion, pupation, moulting, reproduction, fecundity in insects. Also enhances silk production
The lysin motif (LysM) is a ubiquitous motif across kingdoms, which in bacteria allows cell wall degrading enzymes to bind noncovalently to peptidoglycan. This property has been exploited for two decades to design mucosal vaccines consisting of LysM-tagged recombinant proteins anchored to bacterium like particles (BLP) as carriers. Surprisingly, less attention has been paid to apply the LysM motif to protein purification of recombinant proteins. Thus, our goal was to determine if the LysM motif is suitable for recombinant protein purification.
Phytotoxin
phtotoxin produce by bacteria and fungi
Bacterial toxin are two types endotoxin and exotoxins
Fungi produce toxin Mycotoxins
Mycotoxins - Aflatoxins B1, B2, G1, G2,
Products contaminated by aflatoxins such as cereal, tree nuts, dry fruits, spices, dairy products, eggs, and medicinal plants.
There are various methods use for the detections of aflatoxins like HPLC, HPTLC, ELISA,TLC, and LC-MS.
Aflatoxins cause chronic and acute toxicity.
Chronic- slow growth, immunity problems, cirrhosis, and liver cancer.
Acute- Hemorrhage, edema and acute liver toxicity.
Examining Neurobehavioral Toxicity of Patulin in Adult ZebrafishQuang Nguyen
The content of this PowerPoint is strictly for the purpose of submission to the Sigma Xi Research Showcase. Please do not quote/cite/reference materials in this file in its entirety. I am not responsible for any misrepresentation of its reproduction. Any reproduction must have the author's written approval.
Otherwise, I hope you enjoy the slides.
Check out my page at http://patulinzebrafish.tumblr.com/
ABSTRACT- The anticancer drug arsenic trioxide is effective for acute promyelocytic leukemia. But the clinical trials are
restricted due to its potential side effects. Since the major part of arsenic metabolism and detoxification occurs in liver,
this organ faces the major threat. The hepatic side effects include fatty liver, fibrosis, and inflammation and hepatocyte
degeneration. Our study aimed to evaluate the protective potential of the fatty acid, docosahexaenoic acid, against adversities
of arsenic trioxide in an in vitro model, the Chang liver cells. Two preliminary dose standardization assays, cell
viability and lactate dehydrogenase release assays, were employed. The assays were performed as Pre-treatment,
Co-treatment and Post treatment experiments for a period of 24 hours. Arsenic trioxide at various doses (2.5, 5, 7.5, 10,
12.5 and 15 μM) showed a significant (p≤0.05) dose dependant reduction in cell viability along with a dose dependant
enhancement of lactate dehydrogenase release. However when the cells were treated with a combination of docosahexaenoic
acid at varying concentrations (50, 75, 100, 125 and 150 μM), the above mentioned conditions were found to be
reversed in Pre-treatment and Co-treatment experiments, but not in Post treatment. The most effective combination was
found to be 10 μM arsenic trioxide with 100 μM of docosahexaenoic acid in both Pre-treatment and Co- treatment studies.
Thus the preliminary assays of our study showed that docosahexaenoic acid administration as Pre-treatment or
Co-treatment can aid in reducing arsenic trioxide induced hepatotoxicity. Further studies are required to elucidate the mechanisms
behind the protective effects.
Key Words– Arsenic trioxide, hepatotoxicity, docosahexaenoic acid, cell damage
Advantages of microbial biotransformation of bioactive compounds & microbial ...Radwa Ahmed
advantages of the use of microbial biotransformation in the field of natural products.
The microbial models for mammalian drug metabolism and applications in drug studies
Alteration in Protein Metabolic Profiles in Liver Tissue of Rats during Dimet...iosrjce
Dimethoate is the widely used organophosphorous insecticides in agriculture. The irrational use of
Dimethoate in Yemen play a crucial role in the occurrence of many diseases affecting plants, animals and man.
Dimethoate (DM) is used to kill mites and aphids among other insects and is applied on citrus, cotton, fruit,
olives, potatoes, tea, tobacco and vegetables. The aim of the present work was to study biochemical changes
that might occur in the liver of albino rats as a result of DM intoxication. In the present investigation the
animals were treated with 1/10th of LD50 of DM via oral gavage (34.5mg/kg body weight. The first group
animals were considered as control animals. Second group of animals were treated with Dimethoate via oral
gavage (34.5mg/kg body weight which is 1/10th of LD50) for 10 days, third and fourth groups of animals were
administered for 20 and 30 days with an interval of 48h respectively. The DM treated groups are AST and ALT
was selected in the present investigation showed an increment. The present findings indicate that chronic
exposure to DM has clear toxic effect on the liver of albino rats.
phytoecdysteroids affect the larval pupal and adult growth and developements of insects. it affects the digestion, pupation, moulting, reproduction, fecundity in insects. Also enhances silk production
The lysin motif (LysM) is a ubiquitous motif across kingdoms, which in bacteria allows cell wall degrading enzymes to bind noncovalently to peptidoglycan. This property has been exploited for two decades to design mucosal vaccines consisting of LysM-tagged recombinant proteins anchored to bacterium like particles (BLP) as carriers. Surprisingly, less attention has been paid to apply the LysM motif to protein purification of recombinant proteins. Thus, our goal was to determine if the LysM motif is suitable for recombinant protein purification.
Phytotoxin
phtotoxin produce by bacteria and fungi
Bacterial toxin are two types endotoxin and exotoxins
Fungi produce toxin Mycotoxins
Mycotoxins - Aflatoxins B1, B2, G1, G2,
Products contaminated by aflatoxins such as cereal, tree nuts, dry fruits, spices, dairy products, eggs, and medicinal plants.
There are various methods use for the detections of aflatoxins like HPLC, HPTLC, ELISA,TLC, and LC-MS.
Aflatoxins cause chronic and acute toxicity.
Chronic- slow growth, immunity problems, cirrhosis, and liver cancer.
Acute- Hemorrhage, edema and acute liver toxicity.
Examining Neurobehavioral Toxicity of Patulin in Adult ZebrafishQuang Nguyen
The content of this PowerPoint is strictly for the purpose of submission to the Sigma Xi Research Showcase. Please do not quote/cite/reference materials in this file in its entirety. I am not responsible for any misrepresentation of its reproduction. Any reproduction must have the author's written approval.
Otherwise, I hope you enjoy the slides.
Check out my page at http://patulinzebrafish.tumblr.com/
ABSTRACT- The anticancer drug arsenic trioxide is effective for acute promyelocytic leukemia. But the clinical trials are
restricted due to its potential side effects. Since the major part of arsenic metabolism and detoxification occurs in liver,
this organ faces the major threat. The hepatic side effects include fatty liver, fibrosis, and inflammation and hepatocyte
degeneration. Our study aimed to evaluate the protective potential of the fatty acid, docosahexaenoic acid, against adversities
of arsenic trioxide in an in vitro model, the Chang liver cells. Two preliminary dose standardization assays, cell
viability and lactate dehydrogenase release assays, were employed. The assays were performed as Pre-treatment,
Co-treatment and Post treatment experiments for a period of 24 hours. Arsenic trioxide at various doses (2.5, 5, 7.5, 10,
12.5 and 15 μM) showed a significant (p≤0.05) dose dependant reduction in cell viability along with a dose dependant
enhancement of lactate dehydrogenase release. However when the cells were treated with a combination of docosahexaenoic
acid at varying concentrations (50, 75, 100, 125 and 150 μM), the above mentioned conditions were found to be
reversed in Pre-treatment and Co-treatment experiments, but not in Post treatment. The most effective combination was
found to be 10 μM arsenic trioxide with 100 μM of docosahexaenoic acid in both Pre-treatment and Co- treatment studies.
Thus the preliminary assays of our study showed that docosahexaenoic acid administration as Pre-treatment or
Co-treatment can aid in reducing arsenic trioxide induced hepatotoxicity. Further studies are required to elucidate the mechanisms
behind the protective effects.
Key Words– Arsenic trioxide, hepatotoxicity, docosahexaenoic acid, cell damage
Advantages of microbial biotransformation of bioactive compounds & microbial ...Radwa Ahmed
advantages of the use of microbial biotransformation in the field of natural products.
The microbial models for mammalian drug metabolism and applications in drug studies
A short presentation on how to create a Lactobacillus culture (LAB) for use in horticulture. This can be a basis for many things from fermentation to odour control - But by far the best is for making your own free organic liquid plant food!!
Resumen acerca que lactobaillus, bacteria presente en la boca, esofago, estomago, intestino. Se describe su importancia, sus caracteristicas, su habitad, etc.
Bibliografia: Microbilogía oral, Liébana
A genotoxin is a chemical or agent that can cause DNA or chromosomal damage. Such damage in a germ cell has the potential to cause a heritable altered trait (germline mutation). DNA damage in a somatic cell may result in a somatic mutation, which may lead to malignant transformation (cancer). Many in vitro and in vivo tests for genotoxicity have been developed that, with a range of endpoints, detect DNA damage or its biological consequences in prokaryotic (e.g. bacterial) or eukaryotic (e.g. mammalian, avian or yeast) cells. These assays are used to evaluate the safety of environmental chemicals and consumer products and to explore the mechanism of action of known or suspected carcinogens. Many chemical carcinogens/mutagens undergo metabolic activation to reactive species that bind covalently to DNA, and the DNA adducts thus formed can be detected in cells and in human tissues by a variety of sensitive techniques. The detection and characterisation of DNA adducts in human tissues provides clues to the aetiology of human cancer. Characterisation of gene mutations in human tumours, in common with the known mutagenic profiles of genotoxins in experimental systems, may provide further insight into the role of environmental mutagens in human cancer.
Apoptosis is the programmed cell death. Aim of cancer therapy is to destroy the invading cells. Cancerous cells can be destroyed by increasing apoptosis.
it can occur in both physiological and pathological conditions. It is different from necrosis. In necrosis, the cell contents leak out and lead to inflammation. But in apoptosis there is no cellular leakage, only apoptotic bodies are formed. They are then engulfed by macrophages.
Histochemistry in pathology and it'sbranches.pptxDrMUSTAFAAlAmeri
Thi is a simple overview about histochemistry and its branches, how the histological diseases can be diagnosed and what methods are used to examine the tissue.
Application of proteomics for identification of abiotic stress tolerance in c...Vivek Zinzala
It is the study of “Proteome”.
The word "proteome" is a blend of "protein" and "genome”.
Large scale study of Proteins.
Particularly their structures and functions.
Study of full set of proteins in a cell type or tissue, and changes during various conditions
The IOSR Journal of Pharmacy (IOSRPHR) is an open access online & offline peer reviewed international journal, which publishes innovative research papers, reviews, mini-reviews, short communications and notes dealing with Pharmaceutical Sciences( Pharmaceutical Technology, Pharmaceutics, Biopharmaceutics, Pharmacokinetics, Pharmaceutical/Medicinal Chemistry, Computational Chemistry and Molecular Drug Design, Pharmacognosy & Phytochemistry, Pharmacology, Pharmaceutical Analysis, Pharmacy Practice, Clinical and Hospital Pharmacy, Cell Biology, Genomics and Proteomics, Pharmacogenomics, Bioinformatics and Biotechnology of Pharmaceutical Interest........more details on Aim & Scope).
All manuscripts are subject to rapid peer review. Those of high quality (not previously published and not under consideration for publication in another journal) will be published without delay.
Similar to Environmental Stresses on Listeria monocytogenes (20)
Title: Sense of Taste
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 structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
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.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
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
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
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
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
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.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
1. Role of Environmental Stresses on Pathogenicity
of Listeria monocytogenes
Malvi Prakash Golwala (U53409030)
Cell, Molecular and Microbiology
09/30/2016
2. • Gram positive, rod shaped, non-sporulating,
facultative anaerobe.
• Motile via flagella at 30 °C and below
– but usually not at 37 °C, L. monocytogenes can
instead move within eukaryotic cells by
explosive polymerization of actin filaments
(known as comet tails or actin rockets).
3. Fig. 1: Listeria
monocytogenes polym
erizing host
cell actin into comet
tails, Dr. Matteo
Bonazzi, Paris
(http://www.nikonsmallworld.com
/galleries/entry/2008-
photomicrography-
competition/48)
4. Did you also know…
• Listeria is a resilient bacterium.
• Listeria monocytogenes is found in soil and
water. Vegetables can become contaminated
from the soil or from manure used as fertilizer.
• Listeria is killed by pasteurization, and heating
procedures used to prepare ready-to-eat
processed meats.
5. Why the Research?
• Listeria basically contaminates almost all
kinds of foods, processed or fresh.
• Due to its properties of withstanding low
temperatures, salt, pH, etc. it becomes a major
threat in food processing industries.
• A better knowledge of the adaptive
mechanisms of the bacteria to salt stress could
lead to a better control and prevention of this
pathogen in food processing plants. Thus, it is
significant.
6.
7. The paper…
• The review paper focuses on all the recent
researches done in the recent years about how
Listeria is able to withstand these stresses. It
would help us in understanding those
mechanisms.
• The scientists have tried to find the proteins
that are induced or repressed when the bacteria
is under stress.
8. Background
• When bacteria are subjected to a sudden shift
in one/several parameters affecting their
growth or survival, a program of gene
expression is initiated, which is manifested as
an increased or decreased amount of a set of
proteins synthesized in response to stress.
– For instance, in Bacillus subtilis, salt stress
strongly stimulates the expression of a set of
proteins that probably allow the bacterium to
survive in the rapidly changing environment.
9. Background Contd…
• L. monocytogenes, shows elevated osmolarity
in the environment by the intracellular
accumulation of compatible solutes, called
osmolytes, through osmotic activation of their
transport from the medium rather than through
de novo synthesis.
• These osmolytes act in the cytosol by
counterbalancing the external osmolarity, thus
preventing water loss from the cell and
plasmolysis without adversely affecting
macromolecular structure and function(6).
10. How was it done?
• For that purpose, the two-dimensional (2-D)
electrophoresis method, an approach that has
often proved to be the appropriate tool to study
the general expression levels of proteins, was
used(29).
• Identification of salt shock proteins and salt
acclimation proteins was also undertaken by
mass spectrometry (MS) or N-terminal micro-
sequencing.
• Radiolabeling was used for detection.
11. What did they focus on?
• When cells are subjected to a severe stress,
they usually shut off most metabolic activity
and commit themselves to adaptive strategies.
• Consequently, they enter a physiological state
with very little protein synthesis, very different
from the normal growth physiology.
• So protein analysis was performed.
12. Background Contd…
• When salt was increased, Listeria in some
experiments was found to be less virulent. But,
when salt was increased it posed a threat on
people’s lives in terms of blood pressure.
• So, Na was replaced by Ca or K. CaCl2 and
KCl, both were found to maintain the sensory
characteristics in table olives in a research (23).
13. • In slow/ceased growth, the bacterium
undergoes the process of filamentation. It is
most effective at 4℃.
Filamentation of Listeria
Fig. 3: CFU recovered on
TSA and increases in the
relative length of the
longest 10% of cells
(L10, open symbols) of
cold adapted, log phase
cultures of Listeria
monocytogenes strains
FS2 (&), FS12 (N), and
CDC7762 (¤) incubated
in TSB at pH 6.0 with 4%
NaCl.
14.
15.
16. What did they find?
• They found proteins that were repressed as
well as induced due to salt stress.
• In the first 30mins, 26 proteins were modified,
20 of which were repressed and the rest were
over-expressed.
• In the first 60mins, 25 proteins varied, 11 of
which showed reduction in synthesis and 9
showed higher expression.
17. MALDI-TOF Identification
• Matrix-assisted laser desorption/ionization-
Time of Flight is a soft ionization technique
used in mass spectrometry, allowing the
analysis of biomolecules (biopolymers such
as DNA, proteins, peptides, sugars) and
large organic molecules (polymers,
dendrimers, other macromolecules), which
tend to be fragile and fragment when ionized
by more conventional ionization methods.
18. • Tryptic peptide masses on the plot showed
– heat shock protein (DnaK) : spot 13
– elongation factor (EF-Tu) : spot 84
– transporter of glycine betaine (GbuA) : spot 97
– catabolite control protein (CcpA) : spot 133
• Confirmation of correct identification was
done by analyzing the Z score.
MALDI-TOF Identification Contd…
19. • Other proteins found, similar to
– a phosphoglycerate mutase (Pgm): spot 36
– a pyruvate dehydrogenase (PdhD) : spot 44
– an inosine-5-monophosphate dehydrogenase (GuaB)
: spot 48-49
– an alanine dehydrogenase: spot 109
– a homolog of mannose-specific phosphotransferase
system (PTS) enzyme IIAB: spot 155
– general stress protein (Ctc): spot 206
MALDI-TOF Identification Contd…
20. Same Spot Proteins
• Using MS, spot 48 gave the same result as 49;
the same thing was observed for spots 105 and
106.
• Digestion of these proteins by trypsin gave
peptides having approximately the same
masses. It was therefore concluded that spots
48 and 49 were the same protein. Similarly,
spots 105 and 106 were the same protein.
Why was this was not surprising??
21. N-terminal Amino Acid Sequence
Determination
• Edman degradation (developed by Pehr
Edman) is a method of sequencing amino
acids in a peptide.
• In this method, the amino-terminal residue is
labeled and cleaved from the peptide without
disrupting the peptide bonds between other
amino acid residues.
22. N-terminal Amino Acid Sequence
Determination
• This technique enabled identification of the
spots 105-106, 113, and 173 as being similar to
– pyruvate dehydrogenase (PdhA)
– glyceraldehyde-3-phosphate dehydrogenase (Gap)
– CysK: spot 173
respectively,
23. Fig. 5: Two-
dimensional gel
electrophoresis
autoradiogram
of L.
monocytogenes
proteins labeled
during
exponential
growth showing
identified
proteins
synthesized in
response to salt
stress (3.5%
NaCl).
24. General Osmolyte Response of
Listeria
• Accumulated osmolytes (due to acid stress) and
regulon SigB have shown a major role in
preventing desiccation.
• SigB regulon is activated by stresses like, osmotic,
salt, hydrostatic pressure, etc. causes synthesis and
release of over 100 Gsps.
• Listeria has shown to survive desiccation on:
1. dust like particles at 10℃ for 191 days(25)
2. stainless steel for 91 days under simulated food
processing conditions(25).
25. General Osmolyte Response of
Listeria Contd…
Stabilityofcytoplasmicwaterand
turgor
Glycine betaine,
Carnitine (osmotic
stress)
Acetyl carnitine
Proline betaine and
Proline
26. General Osmolyte Response of
Listeria
• But, the research was concluded to the result that
SigB was synthesized generally for stress and the
desiccation survival process was independent of it.
It helps the bacterium survive in limited nutrient
PPS and MM substrates(25).
27. Fig. 6: Desiccation survival of L. monocytogenes 568; sigB (B) and
back complemented sigB (△) cells on stainless steel coupons incubated
at 15℃, 43% RH for 21 days in BHI (open symbols), TSB-glu (grey
symbols), PPS (black symbols). In a) cells were pre-cultured (15℃ for
3 days) and desiccated in the substrates with 0.5% NaCl while in cells
were pre-cultured and desiccated in the substrates with 5% NaCl.
28. Bsh contributes to survival in gut
• Bile salts are cholesterol end-products and are
synthesized in hepatic cells before conjugating to
taurine or glycine.
• Indigenous microflora has over the years
developed resistance for bile or have evolved
different protective mechanisms.
• The cytoplasmic enzyme is also known as
conjugated bile acid hydrolase (CBAH) and is
produced by many gram positive and negative
commensal bacteria (16), Clostridium (16) and
Enterococcus (16).
29. Bsh contributes to survival in gut
Contd…
• The bsh (bile salt hydrolase) gene is regulated by
PrfA (transcriptional activator of virulence
factors).
• The activity of this gene increases in O2 deficient
environments and thus its virulence in adverse
conditions.
• The scientists have shown that the bsh gene, inside
the bacterial genome helps it to protect itself from
the bile salts in the environment and thus acts as a
virulence factor (16).
30. Bsh contributes to survival in gut
Contd…
Fig. 7: Effect of BSH on
persistence in the guinea
pig gastrointestinal tract. L.
monocytogenes EGDe
(black), L. monocytogenes
EGDe Deficient bsh (white)
and back complemented L.
monocytogenes EGDe Dbsh
complemented (grey).
Listeria growth was
followed in the stools at 24,
48 and 72 h.
31. Bsh contributes to survival in gut
Contd…
• Resistance to Glycol-Conjugated Bile Acid
(GDCA) Supports Virulence in Listeria
-Considering the fact that bile has
antimicrobial activity, a research done by
Sleator, R., et al., 2005, concludes that Listeria
is resistant to the bile in murine gall bladder
and especially to one compound, glycol-
conjugated bile acid (GDCA) (19).
32. Surface Proteins and Enzyme
Interactions
• The genome of Listeria monocytogenes contains
331 transport proteins including 19 of those
involved in phosphotransferase sugar-uptake
systems.
• Because it has so many surface secreted proteins,
it becomes easier for it to interact with so many
environmental stresses.
• Almost 30 of the 133 genes code for surface
proteins (17).
33.
34. Surface Proteins and Enzyme
Interactions Contd…
2 significant
genes
srtA
Covalently bind
proteins to CM by
binding to InlA
Encode for sortases and
transamidases
Help escape
macrophages
srtB
Encode proteins that anchor
proteins with C-terminal NXXTN
motif (SvpA)
Encode for sortases and
transamidases
35. Signal Transduction
• The mechanism of signal transduction is made of
two components:
- Histidine kinase (HK)
- Response regulator (RR)
- both are highly conserved
36. Signal Transduction
• In adverse environmental conditions, histidine gets
auto-phosphorylated and that phosphate is
transferred to the aspartic acid in the response
regulator
• When conditions change, this arrangement is
adjusted in order to adjust to the environmental
alterations (18).
37. • Six Ssp proteins were induced:
– two general stress proteins (Gsp), DnaK (17) and Ctc
(18, 36),
– DnaK (heat shock protein) is required for stress
tolerance (stabilizes cellular proteins)
– Ctc is induced in B. subtilis in response to various
stresses, such as salt stress, but its basic function is
unknown
Let’s Discuss!!
38. Let’s Discuss!!
• Phosphoglycerate mutase (Pgm) (enzyme of
glycolysis and gluconeogenesis in B. subtilis
(24), only one of the 20 proteins repressed during
the first 30 min following salt stress).
– This decreased synthesis could be related to the
increasing synthesis of Gap (in order to
compensate for the increasing amount of
phosphoglycerate produced, but still unclear).
39. Let’s Discuss!!
• 11 Sap proteins were detected, and 7 of them
were identified
– GbuA (a subunit of the glycine betaine transport
system GbuABC) (osmoprotectant transporter
accumulated in response to salt stress by L.
monocytogenes and many bacteria, such as B.
subtilis (12)).
40. Let’s Discuss!!
– elongation factor (EF-Tu) (whose synthesis rate
increased in Mycobacterium tuberculosis in the
presence of a high iron concentration (38); might be
implicated in protein folding and/or protection
from stress in Escherichia coli (5))
– homolog of mannose-specific PTS enzyme IIAB
– two pyruvate dehydrogenase subunits (PdhA and
PdhD)
41. Conclusion
• GbuA (overexpressed in the presence of salt) is
directly connected to the salt stress response.
• General stress response, as two Gsp proteins
(DnaK and Ctc) induced after salt stress.
• In addition, because the synthesis of Gap,
PdhA, PdhD, and Pgm is modified in the
presence of salt, it appears that glycolysis is
important after this stress.
42. Conclusion
• SigB protects from all kinds of stresses but
desiccation survival is independent of this
particular regulon.
• Glycine betaine (osmotic stress), proline,
acetyl carnitine, carnitine (osmotic stress),
proline betaine are the most abundantly
released osmolytes.
43. Conclusion
• bsh gene, inside the bacterial genome helps it
to protect itself from the bile salts in the
environment and thus acts as a virulence
factor.
• It shows resistance to GDCA.
44. Conclusion
• Many surface secreted proteins help it to
interact with many environmental stresses.
- srtA and srtB
• Signal transduction mechanisms help it to
survive changing environments which is
common in food processing industries.
45. Well, I think….
• The bacteria is very efficient and smart, which
is kind of fascinating.
• A lot needs to be done for a better
understanding of these processes and
mechanisms especially those of signal
transduction, before we can start devising
techniques to prevent the bacteria.
INTERESTING…!!!
46. Acknowledgments
• Dr. Diane TeStrake, for mentoring me through
the paper and presentation.
• CMMB Dept., for giving me an opportunity to
stand here and present this topic.
• Fellow classmates, friends and family.
Editor's Notes
1. So I am sure we all know listeria very well.
1. It can survive in temperatures from 4 °C (the temperature of a refrigerator), up to 42 °C (the temperature of a hot day in Dubai).
2. Animals can carry the bacterium without appearing ill and can contaminate foods of animal origin such as meats and dairy products. The bacterium has been found in a variety of raw foods, such as uncooked meats and vegetables, as well as in processed foods that become contaminated after processing, such as soft cheeses and cold cuts at the deli counter. Unpasteurized (raw) milk or foods made from unpasteurized milk may contain the bacterium.
3. however, unless good manufacturing practices are followed, contamination can occur after processing.
http://www.biocote.com/5-facts-about-listeria/
http://www.everydayhealth.com/digestive-health/the-facts-about-listeria.aspx
http://www.listeriosisprevention.com/facts.html
2. Therefore, it is necessary to study how it works in high salt concentration as, salting is one of the basic ways of preserving foods.
3. Once we know how it works, we can design ways to prevent it or at least to make it non-pathogenic.
The infection cycle of Listeria monocytogenes. Electron micrographs show the successive steps of adhesion: entry (1), lysis of the vacuole (2), intracellular replication (3), intracellular movements (4), cell-to-cell spread (5–6), formation (7), and lysis (8) of the two membrane vacuole. Virulence factors involved at the different steps are indicated from Reference 27.
Plasmolysis is the process in which cells lose water in a hypertonic solution. The reverse process, cytolysis, can occur if the cell is in a hypotonic solution resulting in a lower external osmotic pressure and a net flow of water into the cell.
Osmolarity the concentration of a solution expressed as the total number of solute particles per liter.
2. EXPRE35S35S label
Bacteria were harvested during their mid-log phase.
3. To obtain a less severe repression of the physiology, a salt concentration which would result in growth rate reduction of 25 to 50% of the unstressed rate was applied.
2 independent labeling experiments were performed considering a 3.5% NaCl conc. As a stressing condition at which the growth rate was 0.108/hr. The first was performed 30 min after the passage in saline medium to identify the salt stress proteins; the second was performed between 60 and 90 min after the addition of salt to identify salt acclimation proteins.
Fig. 4: Scanning electron microscopy (magnification 10 000) of Listeria monocytogenes (a) Scott A and (b) LO28 grown under various conditions.
Fig. 4: Scanning electron microscopy (magnification 10 000) of Listeria monocytogenes (a) Scott A and (b) LO28 grown under various conditions.
It is similar in character to electrospray ionization (ESI) in that both techniques are relatively soft ways of obtaining ions of large molecules in the gas phase, though MALDI produces far fewer multiply charged ions.
Dendrimers: synthetic polymers with branching, treelike structure.
2. Z score is the probability of that a candidate protein in a
database search is the protein being analyzed (computed by
ProFound software).
2. For these proteins verification was not possible, as the Z scores were unknown, so sequence information of selected tryptic peptides was obtained using MALDI-PSD.
3. Post source decay analysis for MALDI. The conjuction of info from this and maldi-tof identified the three proteins on 36, 48-49 and 206 as Pgm, GuaB and Ctc respectively.
Proteins corresponding to spots 44, 109, 155, and 206 were confirmed to be similar to PdhD, an alanine dehydrogenase, a homolog of mannose-specific PTS enzyme IIAB, and Ctc, respectively.
For each pair, the two spots are different isoforms of the same protein, where the proteins could be desaminated, phosphorylated, or modified by chemical groups which shift the protein isoelectric point toward an acidic pH.
The reference numbers of individual protein spots correspond to those discussed in the results.
The research was concluded to the result that SigB was synthesized generally and the desiccation survival process was independent of it. It helps the bacterium survive in limited nutrient PPS and MM substrates (25).
Bile salts have many properties and antimicrobial is one of them. The bile molecules are amphipathic and thus can act on lipid membrane microbes.
They synthesize transport proteins, porins, efflux pumps, etc (16). A few mechanisms include modification of bile salts into hydrolyzed forms of their conjugation states which is a bile salt hydrolase catalyzed reaction (BSH).
3 before. Mutants of bsh deficient bacteria were intravenously injected in guinea pigs to find reduced virulence and colonization in liver (16).
1. It has many transcriptional regulators and a wide range of surface proteins.
Fig. 8: Schematic representation of Listeria monocytogenes bacterium. The thin, light gray line represents the membrane; and the thick, dark gray line represents the cell wall. The position of the virulence genes on the chromosome of Listeria and the localization of the gene products in the different compartments (cytosol, membrane, cell wall, and extracellular milieu) are represented.
SrtA: SrtA deficient mutants could not enter enterocytic like Caco cells or hepatocytic cells. Neither could they colonize in spleen or liver. As know, InlA is irresponsible for virulence, it can be concluded that srtA transports other virulence factors as well, which are yet be studied (17).
SrtB: surface protein SvpA
1. It has many transcriptional regulators and a wide range of surface proteins.
Mutants were made of RR deficiency and growth in the mutant strains was impaired at a salt concentration of 7.5%. It became worse in higher salt concentrations. One of the mutants was grown in presence of hydrogen peroxide and the growth was ceased completely (18).