Staphylococcus aureus is a common cause of food poisoning that produces enterotoxins. S. aureus contamination of foods like meats and dairy can occur through poor food handling or storage. Ingestion of preformed enterotoxins causes symptoms like vomiting and diarrhea within 3 hours on average, as the toxins damage intestinal cells and stimulate vomiting. Major outbreaks have been linked to foods like poultry, meat and dairy. Detection of enterotoxins in foods is needed to confirm S. aureus as the cause of poisoning. Proper food handling and storage can prevent growth and toxin production by this opportunistic pathogen.
Staphylococcal food poisoning is one of the most common foodborne diseases worldwide, caused by ingesting toxins preformed in food by Staphylococcus aureus bacteria. The toxins are heat-stable and can survive cooking or pasteurization. Any food that supports Staphylococcus growth can cause illness. Symptoms include nausea, vomiting, diarrhea and abdominal cramping. While the illness is usually mild and self-limiting, it can occasionally require hospitalization for vulnerable groups. Effective control measures are needed due to its social and economic impacts.
Staphylococcal food poisoning is one of the most common foodborne diseases worldwide, caused by ingesting toxins preformed in food by Staphylococcus aureus bacteria. S. aureus can survive in food and produce heat-stable toxins. Foods that support S. aureus growth may cause illness if toxins are present after cooking. Humans and animals are the primary carriers and reservoirs of S. aureus. Symptoms include nausea, vomiting, diarrhea and other gastrointestinal distress.
This document discusses food safety and foodborne hazards. It defines food safety as handling, preparing, and storing food to prevent illness. There are three main food safety hazards: microbial, chemical, and physical. Several types of bacteria, viruses, parasites, and fungi that can cause foodborne illness are described in detail including their symptoms and how to prevent contamination. Proper food hygiene practices like cleaning, chilling, cooking, and storage temperatures are important to prevent the growth and spread of harmful microbes.
enumeration of bacteria from food borne vegetables (URBAS ASHIQ)Urbas Ashiq
Urbas Ashiq submitted a project report on enumerating bacteria from food-borne vegetables. The report discussed how bacteria commonly cause food poisoning due to improper food handling. It outlined several bacteria that often cause food-borne diseases like Campylobacter, Salmonella, E. coli, and norovirus. To prevent such diseases, the report recommended keeping food clean, separating raw and cooked food, storing food at safe temperatures, and using safe water. It also described treating food poisoning by replacing lost fluids and electrolytes.
Foodborne diseases pose a significant threat to public health worldwide. They can be caused by bacteria, viruses, parasites or toxins entering the body through contaminated food. Major pathogens like Salmonella, E. coli and Campylobacter cause foodborne infections and intoxications with symptoms like diarrhea and vomiting. In developing countries, poor hygienic practices and lack of surveillance exacerbate the foodborne disease burden. Proper food safety practices and surveillance systems are needed to reduce illnesses and deaths from these preventable diseases.
This document is a thesis presented by Nikhil Taduka to fulfill the requirements for a Master of Science degree from the University of Wolverhampton. The thesis investigates the inhibitory efficacy of nisin, a bacteriocin produced by Lactococcus lactis, against various foodborne pathogens and spoilage microorganisms, including S. aureus, L. innocua, and E. coli. A variety of techniques are used to test nisin's efficacy at different concentrations, including minimum inhibitory concentration assays, Miles and Misra tests, well inhibition tests, spiral plating, and a Bioscreen C method. The results show that higher nisin concentrations are more effective against gram-positive bacteria, while gram-negative
Food poisoning can be caused by ingesting toxins or microorganisms through contaminated food. There are three main types - toxic, infective, and intermediate. Common causative agents include Staphylococcus aureus, Bacillus cereus, Clostridium perfringens. Diagnosis involves identifying the bacteria or toxins in food samples or patient stool/vomit. Treatment focuses on rest and hydration, while prevention centers on proper food handling and storage to avoid bacterial growth.
Staphylococcal food poisoning is one of the most common foodborne diseases worldwide, caused by ingesting toxins preformed in food by Staphylococcus aureus bacteria. The toxins are heat-stable and can survive cooking or pasteurization. Any food that supports Staphylococcus growth can cause illness. Symptoms include nausea, vomiting, diarrhea and abdominal cramping. While the illness is usually mild and self-limiting, it can occasionally require hospitalization for vulnerable groups. Effective control measures are needed due to its social and economic impacts.
Staphylococcal food poisoning is one of the most common foodborne diseases worldwide, caused by ingesting toxins preformed in food by Staphylococcus aureus bacteria. S. aureus can survive in food and produce heat-stable toxins. Foods that support S. aureus growth may cause illness if toxins are present after cooking. Humans and animals are the primary carriers and reservoirs of S. aureus. Symptoms include nausea, vomiting, diarrhea and other gastrointestinal distress.
This document discusses food safety and foodborne hazards. It defines food safety as handling, preparing, and storing food to prevent illness. There are three main food safety hazards: microbial, chemical, and physical. Several types of bacteria, viruses, parasites, and fungi that can cause foodborne illness are described in detail including their symptoms and how to prevent contamination. Proper food hygiene practices like cleaning, chilling, cooking, and storage temperatures are important to prevent the growth and spread of harmful microbes.
enumeration of bacteria from food borne vegetables (URBAS ASHIQ)Urbas Ashiq
Urbas Ashiq submitted a project report on enumerating bacteria from food-borne vegetables. The report discussed how bacteria commonly cause food poisoning due to improper food handling. It outlined several bacteria that often cause food-borne diseases like Campylobacter, Salmonella, E. coli, and norovirus. To prevent such diseases, the report recommended keeping food clean, separating raw and cooked food, storing food at safe temperatures, and using safe water. It also described treating food poisoning by replacing lost fluids and electrolytes.
Foodborne diseases pose a significant threat to public health worldwide. They can be caused by bacteria, viruses, parasites or toxins entering the body through contaminated food. Major pathogens like Salmonella, E. coli and Campylobacter cause foodborne infections and intoxications with symptoms like diarrhea and vomiting. In developing countries, poor hygienic practices and lack of surveillance exacerbate the foodborne disease burden. Proper food safety practices and surveillance systems are needed to reduce illnesses and deaths from these preventable diseases.
This document is a thesis presented by Nikhil Taduka to fulfill the requirements for a Master of Science degree from the University of Wolverhampton. The thesis investigates the inhibitory efficacy of nisin, a bacteriocin produced by Lactococcus lactis, against various foodborne pathogens and spoilage microorganisms, including S. aureus, L. innocua, and E. coli. A variety of techniques are used to test nisin's efficacy at different concentrations, including minimum inhibitory concentration assays, Miles and Misra tests, well inhibition tests, spiral plating, and a Bioscreen C method. The results show that higher nisin concentrations are more effective against gram-positive bacteria, while gram-negative
Food poisoning can be caused by ingesting toxins or microorganisms through contaminated food. There are three main types - toxic, infective, and intermediate. Common causative agents include Staphylococcus aureus, Bacillus cereus, Clostridium perfringens. Diagnosis involves identifying the bacteria or toxins in food samples or patient stool/vomit. Treatment focuses on rest and hydration, while prevention centers on proper food handling and storage to avoid bacterial growth.
This document discusses bacterial food poisoning, describing common causative agents, symptoms, pathogenesis, and methods of diagnosis. The major bacterial causes outlined are Staphylococcus aureus, Bacillus cereus, Clostridium perfringens, Salmonella, Clostridium botulinum, and Escherichia coli. Symptom onset times and clinical manifestations are provided for classifying different types of food poisoning. The document also covers food contamination and poisoning prevention methods.
Safety and toxicity evaluation of probiotics foodsSukhveerSingh31
Probiotics can also be defined as “Live microorganisms that when administered in adequate amounts confer a health benefit on the host” (Council for Agricultural Science and Technology).
Notes on food borne pathogens which cause food poisoning for consumers. it include the different types of microorganisms food intoxication, food infection and the difference between them.
73120 Learning OutcomesAfter reading this chapter, .docxtarifarmarie
731
20
Learning Outcomes
After reading this chapter, you will be able to:
20.1 Distinguish between foodborne infection and
foodborne intoxication and provide an example
of each.
20.2 Summarize strategies to prevent foodborne
illness in the home and when traveling.
20.3 Describe how the food supply is protected in
the United States.
20.4 Compare the risks and benefits of food
additives and the use of hormones, antibiot-
ics, and pesticides in both traditionally and
organically grown food.
20.5 Explain what constitutes a sustainable food
system.
20.6 Compare the benefits and risks of the use of
biotechnology in our current food system.
True or False?
1. Foods that contain pathogens that
cause foodborne illness always smell bad. T/F
2. Handwashing is more effective in
preventing food contamination than using a hand sanitizer. T/F
3. A kitchen sponge is a prime environment for the breeding and spread of bacteria. T/F
4. Freezing foods kills the harmful bacteria. T/F
5. Leftovers that have been stored in the fridge for a week are safe to eat. T/F
6. As long as the expiration date hasn’t passed, packaged food is always safe to eat. T/F
7. Food additives must demonstrate a “zero risk” of cancer to human beings in order to meet FDA approval. T/F
8. A diet consisting only of locally grown foods is a sustainable diet. T/F
9. Foods grown organically that carry the USDA organic seal are free of pesticides. T/F
10. Genetically engineered foods are
plentiful in the United States. T/F
See page 773–774 for the answers.
Food Safety,
Technology, and
Sustainability
732 Chapter 20 | Food Safety, Technology, and Sustainability
What Causes Foodborne Illness?
LO 20.1 Distinguish between foodborne infection and foodborne intoxication
and provide an example of each.
Foodborne illness is any disorder caused by consuming contaminated food. It is a major
preventable public health threat worldwide. Every year in the United States, 1 in 6 Ameri-
cans (or 48 million people) experience foodborne illness, and about 128,000 are hospital-
ized.1 Foodborne illness most commonly results in gastrointestinal symptoms such as
cramps, diarrhea, and nausea and vomiting, but in extreme circumstances it can result in
death. Approximately 3,000 Americans die of foodborne illness every year.2
Pathogens and Their Toxins Cause Most Foodborne Illness
The two types of foodborne illness are infection and intoxication. Consuming foods or
beverages that are contaminated with disease-causing organisms, known as pathogens,
causes foodborne infection. Once ingested, the pathogens multiply in the GI tract and
cause illness. Pathogens commonly implicated in foodborne infection include viruses,
bacteria, molds, parasites, and prions (Table 20.1).
Eating foods contaminated with a toxin causes foodborne intoxication. Viruses
and parasites do not cause foodborne intoxication. Certain species of bacteria, however,
do secrete toxins. These include Cl.
Microbiology is a branch of biology that deals with organisms too small to be seen without magnification. It is the study of microorganisms, which are organisms such as bacteria, parasites, viruses, yeasts, molds, etc. that are so small they can only be seen using a microscope. Food microbiology is concerned with the effects microbes or organisms can have on the quality and safety of food products. This paper presents a brief introduction on food microbiology. Matthew N. O. Sadiku | Tolulope J. Ashaolu | Sarhan M. Musa ""Food Microbiology"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-4 , June 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23951.pdf
Paper URL: https://www.ijtsrd.com/chemistry/food-science/23951/food-microbiology/matthew-n-o-sadiku
This document discusses food safety and foodborne illnesses. It provides information on common foodborne pathogens and illnesses, populations at high risk, safe food handling practices, and preventing food contamination. Regulations and standards like the FDA Food Code and HACCP are described. Challenges to food safety from changes in food production and emerging pathogens are also mentioned.
This document discusses foodborne diseases and provides information about staphylococcal food poisoning, botulism, and salmonellosis. It defines foodborne diseases as illnesses acquired through contaminated food consumption. The chapter aims to teach students about the definition, epidemiology, transmission, clinical presentation, diagnosis, treatment and prevention of common foodborne diseases. Specific details are provided about staphylococcal food poisoning caused by Staphylococcus aureus toxins, botulism caused by Clostridium botulinum toxin, and salmonellosis caused by Salmonella bacteria. Prevention focuses on proper food handling, sanitation, and avoiding temperature abuse during food storage and preparation.
Food safety in hospitals is important because patients have weakened immune systems and are at higher risk of foodborne illness. A review of hospital food poisoning outbreaks in Scotland from 1972-1977 found over 1,500 people were infected due to food prepared in hospitals. Food safety aims to prevent food hazards like biological, chemical, physical, and allergic contaminants that can cause health issues. Key aspects of food safety in hospitals include preventing cross-contamination, proper food temperature and storage, hygiene practices, and sanitation.
Food samples: African salad, fried yam, fried potato, fried plantain, bole and suya meat retailed in three locations along Choba, Aluu and Alakahia were analyzed for their microbial load. Analysis of the food samples revealed Total viable count ranging from 3.8×107 cfu/g to 5.2×107 cfu/g (African salad), 2.6×107 cfu/g to 3.3×107 cfu/g (Bole), 3.0×107 cfu/g to 3.4×107 cfu/g (Plantain), 3.4×107 cfu/g to 3.6×107 cfu/g (Potato), 2.9×107 cfu/g to 3.3×107 cfu/g (Yam) and 4.8×107 cfu/g to 5.1×107 cfu/g (Suya meat) from the various locations. The organism isolated includes, Staphylococcus aureus (25%), Escherichia coli (25%), Pseudomonas (15%), Streptococcus (15%), Bacillus cereus (12%) and Salmonella spp (8%). The TVC count in these food samples exceeds the standard set by International Commission for Microbiology Specification for Food (ICMSF) for ready-to-eat food which states that TVC count between 0-107 cfu/g is acceptable, 104 to 105 cfu/g is tolerable and >107 cfu/g is unacceptable. Therefore, these foods are not bacteriologically fit for consumption. The occurrence of these bacterial isolates in the foods constitutes public health risk to consumers as these pathogens have been associated with foodborne infections Therefore, government should enforce strong food safety regulations for street foods vendors. In addition, street food vendors need to be educated on food safety and hygienic practices
This document summarizes a study that examined the prevalence of Staphylococcus aureus and Escherichia coli in sun-cured meat (jerky/kilishi) from retail outlets in Sokoto, Nigeria. A total of 81 meat samples were collected from 10 areas and tested for the presence of S. aureus and E. coli using bacterial culture and biochemical tests. S. aureus was found in 68 samples at a prevalence of 83.9%, while E. coli was not found in any samples (0% prevalence). The contamination rate of S. aureus was highest (100% prevalence) in samples from 4 areas, while other areas had rates of 25%, 60%, and 80%. Due to the high occurrence
Calf Coccidiosis
General about coccidia- Structure- Life cycle- Environmental factors for survival
Eimeria in cattle- Prevalence- Clinical coccidiosis- Sub-clinical coccidiosis
Surveillance and control
What is Coccidiosis?
Enteric disease caused by the protozoan parasites Eimeria spp
The document discusses foodborne diseases of animal origin, including:
1. Bovine tuberculosis caused by Mycobacterium tuberculosis, which can infect humans through infected animal products.
2. Brucellosis caused by Brucella abortus and B. melitensis, which can cause undulant or Malta fever in humans through contact with infected animals or consumption of contaminated food.
3. Several other diseases are described such as anthrax, listeriosis, campylobacteriosis, and Q fever, which can infect humans through consumption of contaminated animal products like milk, meat, or dairy. Proper food handling and hygiene are important for preventing transmission of these zoonotic diseases.
Probiotics and medicinal plants in poultry nutrition: a reviewSubmissionResearchpa
The use of medicinal plants and probiotics has recently gained interest since the ban on the use of antibiotics as growth promoters by the European Union in 2006. They are new alternatives to bridge the gap between food safety and production. Medicinal plants are cheaper and loaded with several minerals, vitamins and phytochemicals such as: alkaloids, saponin, flavonoids, phenols, tannins etc. which allows them to perform multiple biological activities. Probiotics on the other hand, repopulates the gastro intestinal tracts (GIT) with beneficial bacteria which controls the action of pathogens and control their population, thereby reducing mortality and improving general performance of an animal by Akintayo - Balogun Omolere. M and Alagbe, J.O 2020. Probiotics and medicinal plants in poultry nutrition: a review. International Journal on Integrated Education. 3, 10 (Oct. 2020), 214-221. DOI:https://doi.org/10.31149/ijie.v3i10.730 https://journals.researchparks.org/index.php/IJIE/article/view/730/703 https://journals.researchparks.org/index.php/IJIE/article/view/730
Many different disease-causing microbes or pathogens can contaminate foods, so there are many different types of foodborne illnesses.
Most foodborne diseases are infections caused by a variety of bacteria, viruses, and parasites. Other diseases are poisonings caused by harmful toxins or chemicals that have contaminated food.
This document discusses the importance of bacterial culture methods compared to genomic analysis in food microbiology. It makes three key points:
1) Cultural methods are necessary for the detection and enumeration of bacteria in foods, as current genomic methods cannot achieve the high sensitivity required to detect potential pathogens at low levels. Cultural enrichment is required to amplify bacteria to detectable concentrations.
2) Only cultural methods can determine bacterial viability. Genomic analysis cannot distinguish between viable and non-viable cells as it only detects the presence of biomolecules.
3) While genomic analysis excels at bacterial identification and subtyping, it is less reliable for predicting phenotypic characteristics. Cultural methods are still needed to validate phenotype predictions from genomic data.
This document analyzes the relationship between food and the intestinal microbiota in humans. It discusses what intestinal microbiomes are, their roles, and their relationship with the host. The document explores how diet can modulate gut microbiome composition and influence enterotypes. It summarizes research studies that link long-term diet to enterotypes and show the gut microbiome of malnourished children remains immature. The conclusion is that food affects the gut flora, which in turn impacts health and development.
Training Slide which outlines measures that will
Assist food businesses achieve the requirements of the Food Safety Standards.
Provide food handlers with the necessary skills and knowledge of food safety and hygiene matters relevant to their work activities.
Raise the level of compliance with food legislation throughout the food industry.
Chapter 16 food safety and hygiene.pptxOsmanHassan35
This document provides an introduction to a training presentation on food safety and hygiene. It discusses the importance of food safety, highlighting increasing cases of food poisoning in Nigeria stemming from poor food handling and hygiene practices. The objectives of the training are to help food businesses meet food safety standards, provide food handlers with skills and knowledge on food safety matters, and increase compliance with food legislation. The training covers topics like food poisoning causes, bacteria, hygiene control, personal hygiene, pest control, temperature control, cleaning and disinfection, and food safety management systems.
Clinical immunology is the study of diseases caused by disorders of the immune system (failure, aberrant action, and malignant growth of the cellular elements of the system). It also involves diseases of other systems, where immune reactions play a part in the pathology and clinical features.
The training slide outlines food safety culture that will
Assist food businesses achieve the requirements of the Food Safety Standards.
Provide food handlers with the necessary skills and knowledge of food safety and hygiene matters relevant to their work activities.
Raise the level of compliance with food legislation throughout the food industry.
This presentation offers a general idea of the structure of seed, seed production, management of seeds and its allied technologies. It also offers the concept of gene erosion and the practices used to control it. Nursery and gardening have been widely explored along with their importance in the related domain.
This document discusses bacterial food poisoning, describing common causative agents, symptoms, pathogenesis, and methods of diagnosis. The major bacterial causes outlined are Staphylococcus aureus, Bacillus cereus, Clostridium perfringens, Salmonella, Clostridium botulinum, and Escherichia coli. Symptom onset times and clinical manifestations are provided for classifying different types of food poisoning. The document also covers food contamination and poisoning prevention methods.
Safety and toxicity evaluation of probiotics foodsSukhveerSingh31
Probiotics can also be defined as “Live microorganisms that when administered in adequate amounts confer a health benefit on the host” (Council for Agricultural Science and Technology).
Notes on food borne pathogens which cause food poisoning for consumers. it include the different types of microorganisms food intoxication, food infection and the difference between them.
73120 Learning OutcomesAfter reading this chapter, .docxtarifarmarie
731
20
Learning Outcomes
After reading this chapter, you will be able to:
20.1 Distinguish between foodborne infection and
foodborne intoxication and provide an example
of each.
20.2 Summarize strategies to prevent foodborne
illness in the home and when traveling.
20.3 Describe how the food supply is protected in
the United States.
20.4 Compare the risks and benefits of food
additives and the use of hormones, antibiot-
ics, and pesticides in both traditionally and
organically grown food.
20.5 Explain what constitutes a sustainable food
system.
20.6 Compare the benefits and risks of the use of
biotechnology in our current food system.
True or False?
1. Foods that contain pathogens that
cause foodborne illness always smell bad. T/F
2. Handwashing is more effective in
preventing food contamination than using a hand sanitizer. T/F
3. A kitchen sponge is a prime environment for the breeding and spread of bacteria. T/F
4. Freezing foods kills the harmful bacteria. T/F
5. Leftovers that have been stored in the fridge for a week are safe to eat. T/F
6. As long as the expiration date hasn’t passed, packaged food is always safe to eat. T/F
7. Food additives must demonstrate a “zero risk” of cancer to human beings in order to meet FDA approval. T/F
8. A diet consisting only of locally grown foods is a sustainable diet. T/F
9. Foods grown organically that carry the USDA organic seal are free of pesticides. T/F
10. Genetically engineered foods are
plentiful in the United States. T/F
See page 773–774 for the answers.
Food Safety,
Technology, and
Sustainability
732 Chapter 20 | Food Safety, Technology, and Sustainability
What Causes Foodborne Illness?
LO 20.1 Distinguish between foodborne infection and foodborne intoxication
and provide an example of each.
Foodborne illness is any disorder caused by consuming contaminated food. It is a major
preventable public health threat worldwide. Every year in the United States, 1 in 6 Ameri-
cans (or 48 million people) experience foodborne illness, and about 128,000 are hospital-
ized.1 Foodborne illness most commonly results in gastrointestinal symptoms such as
cramps, diarrhea, and nausea and vomiting, but in extreme circumstances it can result in
death. Approximately 3,000 Americans die of foodborne illness every year.2
Pathogens and Their Toxins Cause Most Foodborne Illness
The two types of foodborne illness are infection and intoxication. Consuming foods or
beverages that are contaminated with disease-causing organisms, known as pathogens,
causes foodborne infection. Once ingested, the pathogens multiply in the GI tract and
cause illness. Pathogens commonly implicated in foodborne infection include viruses,
bacteria, molds, parasites, and prions (Table 20.1).
Eating foods contaminated with a toxin causes foodborne intoxication. Viruses
and parasites do not cause foodborne intoxication. Certain species of bacteria, however,
do secrete toxins. These include Cl.
Microbiology is a branch of biology that deals with organisms too small to be seen without magnification. It is the study of microorganisms, which are organisms such as bacteria, parasites, viruses, yeasts, molds, etc. that are so small they can only be seen using a microscope. Food microbiology is concerned with the effects microbes or organisms can have on the quality and safety of food products. This paper presents a brief introduction on food microbiology. Matthew N. O. Sadiku | Tolulope J. Ashaolu | Sarhan M. Musa ""Food Microbiology"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-4 , June 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23951.pdf
Paper URL: https://www.ijtsrd.com/chemistry/food-science/23951/food-microbiology/matthew-n-o-sadiku
This document discusses food safety and foodborne illnesses. It provides information on common foodborne pathogens and illnesses, populations at high risk, safe food handling practices, and preventing food contamination. Regulations and standards like the FDA Food Code and HACCP are described. Challenges to food safety from changes in food production and emerging pathogens are also mentioned.
This document discusses foodborne diseases and provides information about staphylococcal food poisoning, botulism, and salmonellosis. It defines foodborne diseases as illnesses acquired through contaminated food consumption. The chapter aims to teach students about the definition, epidemiology, transmission, clinical presentation, diagnosis, treatment and prevention of common foodborne diseases. Specific details are provided about staphylococcal food poisoning caused by Staphylococcus aureus toxins, botulism caused by Clostridium botulinum toxin, and salmonellosis caused by Salmonella bacteria. Prevention focuses on proper food handling, sanitation, and avoiding temperature abuse during food storage and preparation.
Food safety in hospitals is important because patients have weakened immune systems and are at higher risk of foodborne illness. A review of hospital food poisoning outbreaks in Scotland from 1972-1977 found over 1,500 people were infected due to food prepared in hospitals. Food safety aims to prevent food hazards like biological, chemical, physical, and allergic contaminants that can cause health issues. Key aspects of food safety in hospitals include preventing cross-contamination, proper food temperature and storage, hygiene practices, and sanitation.
Food samples: African salad, fried yam, fried potato, fried plantain, bole and suya meat retailed in three locations along Choba, Aluu and Alakahia were analyzed for their microbial load. Analysis of the food samples revealed Total viable count ranging from 3.8×107 cfu/g to 5.2×107 cfu/g (African salad), 2.6×107 cfu/g to 3.3×107 cfu/g (Bole), 3.0×107 cfu/g to 3.4×107 cfu/g (Plantain), 3.4×107 cfu/g to 3.6×107 cfu/g (Potato), 2.9×107 cfu/g to 3.3×107 cfu/g (Yam) and 4.8×107 cfu/g to 5.1×107 cfu/g (Suya meat) from the various locations. The organism isolated includes, Staphylococcus aureus (25%), Escherichia coli (25%), Pseudomonas (15%), Streptococcus (15%), Bacillus cereus (12%) and Salmonella spp (8%). The TVC count in these food samples exceeds the standard set by International Commission for Microbiology Specification for Food (ICMSF) for ready-to-eat food which states that TVC count between 0-107 cfu/g is acceptable, 104 to 105 cfu/g is tolerable and >107 cfu/g is unacceptable. Therefore, these foods are not bacteriologically fit for consumption. The occurrence of these bacterial isolates in the foods constitutes public health risk to consumers as these pathogens have been associated with foodborne infections Therefore, government should enforce strong food safety regulations for street foods vendors. In addition, street food vendors need to be educated on food safety and hygienic practices
This document summarizes a study that examined the prevalence of Staphylococcus aureus and Escherichia coli in sun-cured meat (jerky/kilishi) from retail outlets in Sokoto, Nigeria. A total of 81 meat samples were collected from 10 areas and tested for the presence of S. aureus and E. coli using bacterial culture and biochemical tests. S. aureus was found in 68 samples at a prevalence of 83.9%, while E. coli was not found in any samples (0% prevalence). The contamination rate of S. aureus was highest (100% prevalence) in samples from 4 areas, while other areas had rates of 25%, 60%, and 80%. Due to the high occurrence
Calf Coccidiosis
General about coccidia- Structure- Life cycle- Environmental factors for survival
Eimeria in cattle- Prevalence- Clinical coccidiosis- Sub-clinical coccidiosis
Surveillance and control
What is Coccidiosis?
Enteric disease caused by the protozoan parasites Eimeria spp
The document discusses foodborne diseases of animal origin, including:
1. Bovine tuberculosis caused by Mycobacterium tuberculosis, which can infect humans through infected animal products.
2. Brucellosis caused by Brucella abortus and B. melitensis, which can cause undulant or Malta fever in humans through contact with infected animals or consumption of contaminated food.
3. Several other diseases are described such as anthrax, listeriosis, campylobacteriosis, and Q fever, which can infect humans through consumption of contaminated animal products like milk, meat, or dairy. Proper food handling and hygiene are important for preventing transmission of these zoonotic diseases.
Probiotics and medicinal plants in poultry nutrition: a reviewSubmissionResearchpa
The use of medicinal plants and probiotics has recently gained interest since the ban on the use of antibiotics as growth promoters by the European Union in 2006. They are new alternatives to bridge the gap between food safety and production. Medicinal plants are cheaper and loaded with several minerals, vitamins and phytochemicals such as: alkaloids, saponin, flavonoids, phenols, tannins etc. which allows them to perform multiple biological activities. Probiotics on the other hand, repopulates the gastro intestinal tracts (GIT) with beneficial bacteria which controls the action of pathogens and control their population, thereby reducing mortality and improving general performance of an animal by Akintayo - Balogun Omolere. M and Alagbe, J.O 2020. Probiotics and medicinal plants in poultry nutrition: a review. International Journal on Integrated Education. 3, 10 (Oct. 2020), 214-221. DOI:https://doi.org/10.31149/ijie.v3i10.730 https://journals.researchparks.org/index.php/IJIE/article/view/730/703 https://journals.researchparks.org/index.php/IJIE/article/view/730
Many different disease-causing microbes or pathogens can contaminate foods, so there are many different types of foodborne illnesses.
Most foodborne diseases are infections caused by a variety of bacteria, viruses, and parasites. Other diseases are poisonings caused by harmful toxins or chemicals that have contaminated food.
This document discusses the importance of bacterial culture methods compared to genomic analysis in food microbiology. It makes three key points:
1) Cultural methods are necessary for the detection and enumeration of bacteria in foods, as current genomic methods cannot achieve the high sensitivity required to detect potential pathogens at low levels. Cultural enrichment is required to amplify bacteria to detectable concentrations.
2) Only cultural methods can determine bacterial viability. Genomic analysis cannot distinguish between viable and non-viable cells as it only detects the presence of biomolecules.
3) While genomic analysis excels at bacterial identification and subtyping, it is less reliable for predicting phenotypic characteristics. Cultural methods are still needed to validate phenotype predictions from genomic data.
This document analyzes the relationship between food and the intestinal microbiota in humans. It discusses what intestinal microbiomes are, their roles, and their relationship with the host. The document explores how diet can modulate gut microbiome composition and influence enterotypes. It summarizes research studies that link long-term diet to enterotypes and show the gut microbiome of malnourished children remains immature. The conclusion is that food affects the gut flora, which in turn impacts health and development.
Training Slide which outlines measures that will
Assist food businesses achieve the requirements of the Food Safety Standards.
Provide food handlers with the necessary skills and knowledge of food safety and hygiene matters relevant to their work activities.
Raise the level of compliance with food legislation throughout the food industry.
Chapter 16 food safety and hygiene.pptxOsmanHassan35
This document provides an introduction to a training presentation on food safety and hygiene. It discusses the importance of food safety, highlighting increasing cases of food poisoning in Nigeria stemming from poor food handling and hygiene practices. The objectives of the training are to help food businesses meet food safety standards, provide food handlers with skills and knowledge on food safety matters, and increase compliance with food legislation. The training covers topics like food poisoning causes, bacteria, hygiene control, personal hygiene, pest control, temperature control, cleaning and disinfection, and food safety management systems.
Clinical immunology is the study of diseases caused by disorders of the immune system (failure, aberrant action, and malignant growth of the cellular elements of the system). It also involves diseases of other systems, where immune reactions play a part in the pathology and clinical features.
The training slide outlines food safety culture that will
Assist food businesses achieve the requirements of the Food Safety Standards.
Provide food handlers with the necessary skills and knowledge of food safety and hygiene matters relevant to their work activities.
Raise the level of compliance with food legislation throughout the food industry.
This presentation offers a general idea of the structure of seed, seed production, management of seeds and its allied technologies. It also offers the concept of gene erosion and the practices used to control it. Nursery and gardening have been widely explored along with their importance in the related domain.
SDSS1335+0728: The awakening of a ∼ 106M⊙ black hole⋆Sérgio Sacani
Context. The early-type galaxy SDSS J133519.91+072807.4 (hereafter SDSS1335+0728), which had exhibited no prior optical variations during the preceding two decades, began showing significant nuclear variability in the Zwicky Transient Facility (ZTF) alert stream from December 2019 (as ZTF19acnskyy). This variability behaviour, coupled with the host-galaxy properties, suggests that SDSS1335+0728 hosts a ∼ 106M⊙ black hole (BH) that is currently in the process of ‘turning on’. Aims. We present a multi-wavelength photometric analysis and spectroscopic follow-up performed with the aim of better understanding the origin of the nuclear variations detected in SDSS1335+0728. Methods. We used archival photometry (from WISE, 2MASS, SDSS, GALEX, eROSITA) and spectroscopic data (from SDSS and LAMOST) to study the state of SDSS1335+0728 prior to December 2019, and new observations from Swift, SOAR/Goodman, VLT/X-shooter, and Keck/LRIS taken after its turn-on to characterise its current state. We analysed the variability of SDSS1335+0728 in the X-ray/UV/optical/mid-infrared range, modelled its spectral energy distribution prior to and after December 2019, and studied the evolution of its UV/optical spectra. Results. From our multi-wavelength photometric analysis, we find that: (a) since 2021, the UV flux (from Swift/UVOT observations) is four times brighter than the flux reported by GALEX in 2004; (b) since June 2022, the mid-infrared flux has risen more than two times, and the W1−W2 WISE colour has become redder; and (c) since February 2024, the source has begun showing X-ray emission. From our spectroscopic follow-up, we see that (i) the narrow emission line ratios are now consistent with a more energetic ionising continuum; (ii) broad emission lines are not detected; and (iii) the [OIII] line increased its flux ∼ 3.6 years after the first ZTF alert, which implies a relatively compact narrow-line-emitting region. Conclusions. We conclude that the variations observed in SDSS1335+0728 could be either explained by a ∼ 106M⊙ AGN that is just turning on or by an exotic tidal disruption event (TDE). If the former is true, SDSS1335+0728 is one of the strongest cases of an AGNobserved in the process of activating. If the latter were found to be the case, it would correspond to the longest and faintest TDE ever observed (or another class of still unknown nuclear transient). Future observations of SDSS1335+0728 are crucial to further understand its behaviour. Key words. galaxies: active– accretion, accretion discs– galaxies: individual: SDSS J133519.91+072807.4
Sexuality - Issues, Attitude and Behaviour - Applied Social Psychology - Psyc...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Signatures of wave erosion in Titan’s coastsSérgio Sacani
The shorelines of Titan’s hydrocarbon seas trace flooded erosional landforms such as river valleys; however, it isunclear whether coastal erosion has subsequently altered these shorelines. Spacecraft observations and theo-retical models suggest that wind may cause waves to form on Titan’s seas, potentially driving coastal erosion,but the observational evidence of waves is indirect, and the processes affecting shoreline evolution on Titanremain unknown. No widely accepted framework exists for using shoreline morphology to quantitatively dis-cern coastal erosion mechanisms, even on Earth, where the dominant mechanisms are known. We combinelandscape evolution models with measurements of shoreline shape on Earth to characterize how differentcoastal erosion mechanisms affect shoreline morphology. Applying this framework to Titan, we find that theshorelines of Titan’s seas are most consistent with flooded landscapes that subsequently have been eroded bywaves, rather than a uniform erosional process or no coastal erosion, particularly if wave growth saturates atfetch lengths of tens of kilometers.
TOPIC OF DISCUSSION: CENTRIFUGATION SLIDESHARE.pptxshubhijain836
Centrifugation is a powerful technique used in laboratories to separate components of a heterogeneous mixture based on their density. This process utilizes centrifugal force to rapidly spin samples, causing denser particles to migrate outward more quickly than lighter ones. As a result, distinct layers form within the sample tube, allowing for easy isolation and purification of target substances.
JAMES WEBB STUDY THE MASSIVE BLACK HOLE SEEDSSérgio Sacani
The pathway(s) to seeding the massive black holes (MBHs) that exist at the heart of galaxies in the present and distant Universe remains an unsolved problem. Here we categorise, describe and quantitatively discuss the formation pathways of both light and heavy seeds. We emphasise that the most recent computational models suggest that rather than a bimodal-like mass spectrum between light and heavy seeds with light at one end and heavy at the other that instead a continuum exists. Light seeds being more ubiquitous and the heavier seeds becoming less and less abundant due the rarer environmental conditions required for their formation. We therefore examine the different mechanisms that give rise to different seed mass spectrums. We show how and why the mechanisms that produce the heaviest seeds are also among the rarest events in the Universe and are hence extremely unlikely to be the seeds for the vast majority of the MBH population. We quantify, within the limits of the current large uncertainties in the seeding processes, the expected number densities of the seed mass spectrum. We argue that light seeds must be at least 103 to 105 times more numerous than heavy seeds to explain the MBH population as a whole. Based on our current understanding of the seed population this makes heavy seeds (Mseed > 103 M⊙) a significantly more likely pathway given that heavy seeds have an abundance pattern than is close to and likely in excess of 10−4 compared to light seeds. Finally, we examine the current state-of-the-art in numerical calculations and recent observations and plot a path forward for near-future advances in both domains.
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...Creative-Biolabs
Neutralizing antibodies, pivotal in immune defense, specifically bind and inhibit viral pathogens, thereby playing a crucial role in protecting against and mitigating infectious diseases. In this slide, we will introduce what antibodies and neutralizing antibodies are, the production and regulation of neutralizing antibodies, their mechanisms of action, classification and applications, as well as the challenges they face.
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...Sérgio Sacani
Context. The observation of several L-band emission sources in the S cluster has led to a rich discussion of their nature. However, a definitive answer to the classification of the dusty objects requires an explanation for the detection of compact Doppler-shifted Brγ emission. The ionized hydrogen in combination with the observation of mid-infrared L-band continuum emission suggests that most of these sources are embedded in a dusty envelope. These embedded sources are part of the S-cluster, and their relationship to the S-stars is still under debate. To date, the question of the origin of these two populations has been vague, although all explanations favor migration processes for the individual cluster members. Aims. This work revisits the S-cluster and its dusty members orbiting the supermassive black hole SgrA* on bound Keplerian orbits from a kinematic perspective. The aim is to explore the Keplerian parameters for patterns that might imply a nonrandom distribution of the sample. Additionally, various analytical aspects are considered to address the nature of the dusty sources. Methods. Based on the photometric analysis, we estimated the individual H−K and K−L colors for the source sample and compared the results to known cluster members. The classification revealed a noticeable contrast between the S-stars and the dusty sources. To fit the flux-density distribution, we utilized the radiative transfer code HYPERION and implemented a young stellar object Class I model. We obtained the position angle from the Keplerian fit results; additionally, we analyzed the distribution of the inclinations and the longitudes of the ascending node. Results. The colors of the dusty sources suggest a stellar nature consistent with the spectral energy distribution in the near and midinfrared domains. Furthermore, the evaporation timescales of dusty and gaseous clumps in the vicinity of SgrA* are much shorter ( 2yr) than the epochs covered by the observations (≈15yr). In addition to the strong evidence for the stellar classification of the D-sources, we also find a clear disk-like pattern following the arrangements of S-stars proposed in the literature. Furthermore, we find a global intrinsic inclination for all dusty sources of 60 ± 20◦, implying a common formation process. Conclusions. The pattern of the dusty sources manifested in the distribution of the position angles, inclinations, and longitudes of the ascending node strongly suggests two different scenarios: the main-sequence stars and the dusty stellar S-cluster sources share a common formation history or migrated with a similar formation channel in the vicinity of SgrA*. Alternatively, the gravitational influence of SgrA* in combination with a massive perturber, such as a putative intermediate mass black hole in the IRS 13 cluster, forces the dusty objects and S-stars to follow a particular orbital arrangement. Key words. stars: black holes– stars: formation– Galaxy: center– galaxies: star formation
2. Introduction
• Gram positive bacteria (cocci shaped that
occur in clusters & member of Bacillota)
• Commensal bacteria in human microbiota.
• Opportunistic pathogen (common contributor
to skin diseases, sinusitis, and food poisoning)
Fig 1 – morphology of S. aureus under microscope
after gram staining (Ganguly, 2018)
Staphylococcal food-borne disease (SFP) results from the contamination of
food by S. aureus’s enterotoxins (SE). (Kadariya, Smith and Thapaliya, 2014)
Food intoxication (Staphyloenterotoxicosis)
• S. aureus bacteria is killed by cooking, but its toxins are resistant to heat
(withstand heat at 121°C for 10 min) and stomach enzymes
(proteases).
(M. Tallent, W. Bennett and M. Miller, 2022)
3. Symptoms and Incubation period
It is generally understood and accepted that S. aureus as a food
intoxicant presents a risk only when the growth to high numbers
occurs - >/= 100,000 CFU/g (>/= 1mg). (Rajkovic, 2016)
Primary symptoms: Vomiting, nausea, diarrhoea and
abdominal pain.
Secondary symptoms : dehydration, headache, myalgia and
fatigue
Incubation period: Symptoms generally occurs between 30
minutes to 8 hours (average of 3 hours) after ingestion.
Symptoms lasts 1-3 days. (CDC, 2018)
Images generated by (Bio render 2023
4. Food sources and transmissions
• Prefers to deposit their enterotoxins on poultry, meats, diary, bakery products and salads.
In raw foods, S. aureus does not compete effectively with indigenous bacteria. Source of contamination?
Air, dust, and food contact surfaces
can all act as carriers for S. aureus to
enter foods.
(Image by (WebstaurantStore, 2023)
.
Source: Argudín, Mendoza and Rodicio, 2010
Major source of contamination is poor
handling of cooked or processed foods
and followed by storage suitable.
(Image by blog.userve.com, 2022)
S. aureus is also found in dairy cattle
(cows), particularly those with
subclinical mastitis.
(Image by Webb, 2023)
5. Some Outbreaks
Table 1: some examples of outbreaks of Staphyloenterotoxicosis (Hennekinne, De Buyser and Dragacci, 2012)
Year Place, Country Food source Cases References
6. Pathogenesis/virulence & Mode of action (i)
Table 2: Main Staphylococcal enterotoxin (SE) of S. aureus involved in food (Pinchuk, Beswick and Reyes, 2010)
•After the consumption, enterotoxins are
absorbed in the abdomen and cause typical
gastroenteritis.
•Induces 5-hydroxytrytamine (5-HT) from mast
cells which stimulates the vomiting centre of the
brain
•Enterotoxins also cause damage to the
epithelial lining of the intestinal cells.
The genes for enterotoxin production are present in
pathogenicity islands in the chromosome (Arun K. Bhunia 2018)
Source: Dura, 2021
Fig 2: S. aureus enterotoxins in stomach
(Arun K. Bhunia 2018 citied in Dura, 2021)
Fig 3: S. aureus enterotoxins in intestinal
cells (Fisher E. L, et al. 2018)
7. Pathogenesis/virulence & Mode of action (ii)
• SEs are superantigens (SAgs) - stimulates many T-cells
• Enterotoxins form complex with MHC class II molecules on surface of antigen-
presenting cells
• Proliferates T-cells, producing a large amounts of inflammatory cytokines (IL-2, IFNγ,
IL-1, TNF-α).
• A high abundance of inflammatory cytokines stimulates the neuron receptors in the
intestinal tract and causes diarrhoea.
Source: Dura, 2021
Fig 4: SEs as superantigen (Fisher E. L, et al. 2018)
1. 15-year-old (healthy) boy presented with septic shock after eating meat from
a fast-food restaurant.
2. Developed food intoxication symptoms (diarrhoea) after 4 hours.
3. TSST-1 gene verified by real-time PCR analysis of the S.aureus strain.
Source: Goudsmit et al., 2021
• Food poising from S. aureus cause toxic shock syndrome, a SAgs called toxic
shock syndrome toxin 1 (TSST-1), is produced.
9. Prevention
• Prevent food from being held at an unsafe temperature
(between 4.4°C and 60°C) for more than 2 hours.
• Refrigerate as soon as possible (below 4 °C ).
• Food handlers practicing good hygiene.
• Avoid cross contamination (raw and cooked food).
• If reheating food, ensure the temperature reaches at least
74 °C .
Image by Evans, n.d shown in Pinterest n.d
10. References
• Argudín, M.Á., Mendoza, M.C. and Rodicio, M.R. (2010). Food Poisoning and Staphylococcus aureus Enterotoxins. Toxins, [online] 2(7), pp.1751–1773. doi:https://doi.org/10.3390/toxins2071751.
• blog.userve.com. (2022). Food Handler How-To: Handle Poultry Properly. [online] Available at: https://blog.userve.com/us/food-handler-how-to-handle-poultry-properly [Accessed 5 Nov. 2023].
• Centers for Disease Control and Prevention (2018). Staphylococcal (staph) food poisoning. [online] Centers for Disease Control and Prevention. Available at:
https://www.cdc.gov/foodsafety/diseases/staphylococcal.html.
• Ganguly, S. (2018). Photograph showing S. aureus grape cluster like morphology on Gram stain. 1000X. [Image] ResearchGate. Available at:
https://www.researchgate.net/publication/322243680_Molecular_Characterization_of_Staphylococcus_aureus_of_Camel_Camelus_dromedarius_Skin_Origin/figures?lo=1 [Accessed 30 Oct. 2023]
• Kadariya, J., Smith, T.C. and Thapaliya, D. (2014). Staphylococcus aureus and Staphylococcal food-borne disease: An ongoing challenge in public health. BioMed Research International, [online] 2014, pp.1–
9. doi:https://doi.org/10.1155/2014/827965
• Rajkovic, A. (2016). Staphylococcus: Food Poisoning. [online] , Ghent University, Ghent, Belgium & Belgrade University, Zemun-Belgrade, Serbia: Elsevier Ltd, pp.133–139. Available at:
https://elearning.unite.it/pluginfile.php/187875/mod_resource/content/0/rajkovic%2C2016-Staphylococcus-food%20poisoning.pdf [Accessed 2 Nov. 2023].
• Hennekinne, J.-A., De Buyser, M.-L. and Dragacci, S. (2012). Staphylococcus aureusand its food poisoning toxins: characterization and outbreak investigation. FEMS Microbiology Reviews, 36(4), pp.815–
836. doi:https://doi.org/10.1111/j.1574-6976.2011.00311.x.
• Pinchuk, I.V., Beswick, E.J. and Reyes, V.E. (2010). Staphylococcal Enterotoxins. Toxins, [online] 2(8), pp.2177–2197. doi:https://doi.org/10.3390/toxins2082177.
• Dura, S. (2021). Staphylococcal food poisoning (SFP)- Staphylococcus aureus enterotoxins. [online] Microbe Notes. Available at: https://microbenotes.com/staphylococcal-food-poisoning/ [Accessed 2 Nov.
2023].
• Fisher, E.L., Otto, M. and Cheung, G.Y.C. (2018). Basis of Virulence in Enterotoxin-Mediated Staphylococcal Food Poisoning. Frontiers in Microbiology, [online] 9(436), pp.1–18.
doi:https://doi.org/10.3389/fmicb.2018.00436.
• M. Tallent, S., W. Bennett , R. and M. Miller, W.B. (2023). BAM Chapter 13B - Staphylococcal Enterotoxins Detection Methods. FDA. [online] Available at: https://www.fda.gov/food/laboratory-methods-
food/bam-chapter-13b-staphylococcal-enterotoxins-detection-methods#:~:text=Staphylococcal%20enterotoxins%20(SEs)%20are%20pyrogenic [Accessed 3 Nov. 2023].
• Webb, B.H. (2023). Dairying. [online] Encyclopedia Britannica. Available at: https://www.britannica.com/topic/dairying.
• WebstaurantStore. (n.d.). WipesPlus 7" x 9" 100 Count No-Rinse Food Contact Surface Sanitizing Wipes. [online] Available at: https://www.webstaurantstore.com/wipesplus-7-x-9-food-contact-sanitizing-
wipes-canister/50033808.html [Accessed 5 Nov. 2023].
• Wu, S., Duan, N., Gu, H., Hao, L., Ye, H., Gong, W. and Wang, Z. (2016). A Review of the Methods for Detection of Staphylococcus aureus Enterotoxins. Toxins, [online] 8(7), p.176.
doi:https://doi.org/10.3390/toxins8070176.
Editor's Notes
2 secounds
30 secounds
Staphylococcus aureus, a natural inhabitant of the human and animal body and reside on either surface of the body or at mucosa without harming human health.
The best way to avoid food poisoning by Staph is to prevent food from being held at an unsafe temperature (between 4.4°C and 60°C) for more than 2 hours.
28
Salted food products, such as ham, have also been implicated, according to the capacity of S. aureus to grow at relatively low water activity (water activity = 0.86)
1m 20 secs
Bakery products, particularly cream-filled pastries and cakes, and sandwich fillings.
Food handlers carrying enterotoxin-producing S. aureus in their noses or on their hands are regarded as the main source of food contamination, via manual contact or through respiratory secretions
Concntrare d in diary
25 different prophage encoded enterotoxins, SEA – SEE are the major reported for food poisoning
Fig 2: the enterotoxin induces the release of 5-HT (5-hydroxytryptamine) from mast cells, which stimulates vagal nerves in the stomach lining and induces vomiting.
Fig 3: The enterotoxins transit through mucus-expelling goblet cells and epithelial cells in the intestinal epithelium to reach the lamina propria. Here, the enterotoxins can interact with mast cells to induce the release of 5-hydroxytryptamine (5-HT/serotonin precursor), which interacts with the vagus nerve to cause an emetic response. Additional cellular targets that may have possible roles in the induction of enterotoxigenic disease include different types of T cells.
Superantigens (SAgs) are a family of highly potent mitogens that share the ability to trigger excessive stimulation of human and other mammalian T lymphocytes. This leads to a massive release of T cell mediators and pro-inflammatory cytokines contributing to diseases such as toxic shock syndrome.
Along with SEs, S. aureus also produces another super antigenic toxin (TSST-1).
3 types of Immunoassays..
1)Optical detection techniques: Optical-based detection methods are widely applied in biomolecular analysis due to their ability to utilize various optical properties for detection, including light absorption, fluorescence/luminescence, chemiluminescence, Raman scattering, and refractive index changes. Optical immunoassays provide advantages such as speed, high sensitivity, real-time monitoring, and suitability for low sample concentrations and simplified sample preparation. These assays have found extensive use in the detection of SEs .
2) Electrochemical detection techniques: Electrochemical immunoassays offer a simple, sensitive, and cost-effective method for quantifying specific entities (SEs) based on changes in electric signals, including current, potential, impedance, and conductance. Researchers have developed various electrochemical detection methods for SEs, such as SEC1 and SEB, with low limits of detection. Signal amplification strategies have been employed to enhance sensitivity, including using polysilicon nanowires, horseradish peroxidase-nanosilica-doped multiwalled carbon nanotubes (HRPSiCNTs), and magnetosomes in combination with polydimethylimidazolium hexafluorophosphate ([D(n-C4)Im][PF6]) and polyaniline nano-gold composite (PANI/Au). These methods enable the detection of SEs at low concentrations, making them suitable for various applications, including the analysis of milk samples.
3) Mass detection techniques:
Mass-based immunoassays rely on detecting small changes in mass to quantify specific entities (SEs). Piezoelectric (PZ) devices, such as quartz crystal microbalances, are used in these assays. When the analyte binds to the adsorbent on the crystal's surface, it increases the mass, causing a decrease in resonance frequency. Researchers have developed piezoelectric immunosensors for SEB and SEC2 detection, with sensitivities down to 0.1 µg/mL. Additionally, magnetoelastic sensors, similar to piezoelectric sensors, detect changes in resonance frequency due to mass loading when an analyte binds to a receptor immobilized on their surface. A magnetoelastic immunosensor for SEB detection achieved a detection limit of 0.5 ng/mL without the need for additional labels. These mass-based sensors offer high sensitivity and quick response times while minimizing costs.
Drawback of immunoassays:
immunobioassays are a reliable and technology for SE detection, which exhibit high sensitivity, wide linear range and feasibility, they require high quality antibodies. The preparation of the antibodies via animal immunization experiments is tedious and time-consuming. Besides, the obtained antibodies may be unstable, and susceptible to modification issues