KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 SECTION A Question 1 a) In the battle against foodborne disease, one of the most important things to do is to keep a close look out for any outbreaks of.
KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 SECTION A Question 1: a) In the battle against foodborne disease, one of the most important things to is to keep a close look out for any outbreaks of foodborne sickness Utilizing this technology will allow for the detection of a foodborne illness epidemic as well as the coordination of a response to such outbreak Campylobacter, Salmonella, Shigella, Escherichia coli that generates shiga toxin, Listeria monocytogenes, and hepatitis A are all examples of diseases that may be transmitted via food in Australia Because of the consistently rising incidence of these illnesses in Australia and the high mortality rate associated with them, there is a pressing need for ongoing surveillance in this country Bacteria such as Campylobacter spp., Cryptosporidium spp., Cyclospora cayetanensis, STEC O157 and STEC non-O157, Listeria monocytogenes, Salmonella spp., and S enterica are examples of pathogens that may cause foodborne illness In the United States, three of the most prevalent causes of foodborne disease are always being monitored: S enterica serotype Typhi, Shigella spp., and Enterobacter enterocolitica They are accountable for the great majority of cases of hospitalisation and fatalities that are caused by food-borne illnesses Because of the larger population and higher sickness rate in the United States, there are more infectious diseases being tracked there than there are in Australia This is due to the fact that the United States has more pathogens b) Both Australia and the United States share seven different pathogens Due to the fact that the frequency of foodborne diseases is often overstated by around 80 percent, it is more appropriate to classify them according to the rates of mortality and hospitalisation as opposed to categorising them based on the number of cases per 100,000 people - - - - Listeria monocytogenes : despite the fact that Listeria monocytogenes is a relatively uncommon foodborne pathogen, those who get it have a 91 percent chance of requiring hospitalization and a 16 percent chance of dying away Shiga-toxin producing E coli STEC O157: The production of Shiga toxin by E.coli STEC O157 was associated with a hospitalisation rate of 0.03 percent and mortality rate of 3.4 percent Salmonella (non-typloidal): Only 0.04 percent of people who have non-typhoidal Salmonella end up in the hospital, but 1.9 percent of those people end up dying away from infection Shigella spp.: There is a wide range of mortality and hospitalization rates associated with Shigella spp., ranging from 0.008 percent to 0.5 percent KLA 604 FOODBORNE PATHOGEN - - - PHU TIEN TRAN 557234 Shiga-toxin producing E coli STEC non-O157 : It is estimated that 0.2 percent of all fatalities are caused by E.coli STEC non-O157, which is capable of producing Shiga toxin Campylobacter spp.: Campylobacter spp has a mortality rate of 0.05 percent and a rate of hospitalisation of 0.009 percent in the United States Salmonella enteritidis typhi: It patients ìnected with Salmonella enteritidis typhi, hospitalisation occurs in approximately 10% of case, although fatalities occur in 0% of cases c) According to the CDC, an incorrect diagnosis of an illness that is transmitted by food happens in around eighty percent of instances This helps to explain why so many individuals who are experiencing diarrhoea not seek medical assistance when they should be The overwhelming majority of patients who go to the doctor not produce samples or submit themselves to testing in order for their ailments to be diagnosed As a consequence of this, the underestimating of the prevalence of food-borne diseases is a severe issue that has to be addressed immediately It might be difficult to determine the source of an illness due to the fact that the onset of foodborne infections can take anywhere from a few hours to many weeks As a consequence of this, individuals are unable to determine what they ate or drank before to experiencing symptoms of illness When an individual lives in a nation that has a sophisticated health care system, the likelihood that someone may get a laboratory diagnostic for a condition such as diarrhoea is increased It's possible that this will lead to varying quantities of data being gathered in various nations for the same illness Due to the fact that foodborne illness surveillance is dependent on the reporting of cases, hospitalizations, and fatalities, it is possible that an underestimation of foodborne diseases could lead to an inappropriate inclusion or exclusion from surveillance, in addition to an inaccurate evaluation of the disease's severity This is because an underestimation of foodborne diseases could lead to a lower number of cases being reported Question 3: Behavior factor Meals that can be prepared in advance, foods that are already prepared to eat, commodities that have longer shelf life, and items that need to be refrigerated are gaining in popularity Less food processing is something that consumers want to see Most of the money spent on food in rich nations goes towards meals that are cooked away from the house At the same time, the number of meals purchased from street vendors by city residents has been growing over the last several years As a direct consequence of this, the frequency of outbreaks of foodborne illness that can be traced back to food that was cooked outside of the house is increasing all over the globe Technological changes KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 The advancement of technology in the processing, packing, preserving, transporting, and storing of food has resulted in the creation of both new foods and new risks Because the bacteria now have ample time to proliferate above 100 CFU/g, Listeria monocytogenes has become more prevalent in ready-to-eat foods as a consequence of increasing refrigeration This is because the bacteria now have the opportunity to develop at a faster rate There is a potential for listeriosis to be transmitted by consumption of a wide variety of ready-to-eat items, such as smoked salmon, cheese, processed meat, and salad Climate impact Alterations to the climate, such as changes in precipitation, temperature, the warming of the ocean, and acidity, have an effect on the environment of bacteria, viruses, fungi, and parasites, which in turn increases the risk of foodborne disease There is little question that the incidence of food-borne illnesses will rise as a result of climate change The formation of bacteria in food is encouraged by a high temperature that is maintained for a prolonged period of time Another sign pointed to the possibility that changes in the seasons are connected to an increase in the number of cases of foodborne contamination and sickness In addition, during the summer months in Canada, there is an increase in the number of cases of salmonellosis, whereas the prevalence of salmonella infections in meat does not change This demonstrates that the human exposure component of the rise in Salmonellosis incidence is responsible for the trend Additionally, reservoir populations rise as a result of climate change, leading to an increase in the total number of disease vectors Foodborne diseases continue to challenge public health security despite improved hygiene, detection technology and in-depth knowledge of pathogens Despite an in-depth knowledge of pathogens, improved hygiene, and detection technology, foodborne diseases continue to be a burden on public health for a number of reasons, including those listed below: - The frequency of pathogens is on the rise For instance, Salmonella Typhimurium is replaced by Salmonella Enteriditis, which is linked to eggs, and the incidence of Trematode infection rises in tropical countries - Mutation and genetic rearrangement are the two mechanisms responsible for the emergence of new, more lethal disease strains - These strains have the potential to acquire resistance to food processing and preservation techniques as well as antibiotics - Pathogens may cause an upsurge in infectious illnesses in new populations They are able to grow or change in sensitive populations - A unique pathogen transmission mechanism has been uncovered For example, the usage of wood pallets may pose grave threats to KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 the safety of our food and medicines Both almonds and peanuts contain the bacterium salmonella There are several species that are unknown because they have not been investigated or suspected Human behaviour, moving demographics, climatic change, economic hardship, and insufficient public health monitoring are some of the other factors that contribute to the spread of viruses as foodborne diseases These factors could also have an effect on the presence or recurrence of bacteria that are responsible for food-borne diseases In summary, the adaptation and metamorphosis of illnesses result in an increase in the frequency and severity of the related public health problems Climate change, greater globalisation, and changes in human behaviour all contribute to the genesis of viruses The emergence of a new disease transmitted via food Consequently, foodborne illnesses continue to represent a concern to public health safety SECTION B Question 4: a) The microorganisms that make up this combination are Streptococcus pyogenes and Bacillus cereus It is feasible to test for the presence of S pyogenes by using blood agar that contains a proportion of sheep blood This kind of media is considered to be selective The existence of distinct clear zones reveals that beta-haemolysis on blood agar is produced by bacteria This may be seen since the clear zones are present It is possible to detect S pyogenes in clinical samples by using MC&S obtained from a throat swab RADT is able to identify carbohydrate antigens that belong to group A It is possible to test food for the presence of enterotoxin Nhe or haemolysin BL by using either a PCR kit or an immunoassay kit PEMBA, MYPA, and Chromogenic agar are all viable options for determining the presence of Bacillus cereus in food and clinical samples, respectively PEMBA contains ingredients that are known to suppress the development of bacteria, including sodium pyruvate, mannitol, and polymyxin B antibiotics MYPA, which is used to monitor the activity of lecithinase, contains the ingredients mannitol, the antibiotic polymyxin B, sodium pyruvate, and egg yolk B cereus will produce blue colonies and a clear zone when grown on chromogenic agar, but it will produce green or blue colonies with a clear zone when grown on brilliant agar b) Toxemia may manifest as enterotoxin, which targets the digestive tract, or neurotoxic, which targets the nervous system Gram-positive bacteria are the cause of enterotoxin formation in food and are transmitted by humans Enterotoxin is a superantigen that has a high heat tolerance and can withstand boiling for many minutes Within a few hours of ingestion, it KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 causes severe spells of stomach cramping, nausea, vomiting, and diarrhoea in addition to these other symptoms The neurotoxin is produced by the vegetative cells of the bacteria Clostridium botulinum, Escherichia coli, and Vibrio cholerae Neurotoxicity is the consequence of a neurotoxin's toxicity to the nerve tissue it impacts In conclusion, gram-positive bacteria produce toxins in street food, and since the food is not stored on hot surfaces or at temperatures above 60 degrees Celsius, nor is it refrigerated, it is relatively easy for people to absorb the toxins c) The food safety problem, which may result in diseases transmitted by food, is caused by a number of different factors Buying products of poor quality or those are beyond their prime and storing them in unsanitary conditions both have a negative impact on the quality of the meal The growth of bacteria is encouraged as a result of this Food handlers have the potential to be a cause of food contamination if they practise inadequate hygiene and manipulate food in an unsafe manner When preparing different kinds of food, such as meats and vegetables, the cutting board and knife must be utilised in a distinct manner each time In addition, many people may have trouble re-heating food to the point where it boils before ingesting it, which may lead to the consumption of unhealthy meals d) Identify hazards: As a rule, street food is not adequately kept, which increases the risk of contracting a number of illnesses that are transmitted via food Cross-contamination might occur in the food industry if employees did not practise proper hygiene Identify critical control points: Because street food is not stored in a facility that is either refrigerated or heated, germs have the potential to live for up to four hours after it has been prepared Because there is a lack of water and soap in many of the restaurants that serve street food, many of the employees in these restaurants not wash their hands after handling possibly contaminated raw materials or meat Establish critical limits: Consumption of the meal must take place either two hours after it has been cooked or if it has been kept at under or above 60 degrees Celsius Employees in the food industry are required to wash their hands with soap and water after processing raw ingredients and meats Set corrective actions: After the food has been made, the details of its preparation together with an estimate of the length of time it cannot be sold are required to be noted on a page In the working area, make sure there is a supply of water and soap for anyone who handle food Question 5: What was the basis of the infection problem associated with this person? Mary Mallon works in the kitchen of a New York City restaurant The typhoid fever she was sick with was undetectable to the naked eye Despite her illness, she continued to work and transmitted it to others by touching her KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 infected hands to other people or items This outbreak of salmonella typhoid led to the deaths of fifty people, the sickness of one hundred and seventyfive others, and the hospitalisation of about one thousand two hundred students from schools throughout the state What made the infection distinct in terms of the infectious agent compared to less virulent serotypes of the same species? This illness is caused by either Salmonella typhi or Salmonella paratyphi The presence of the O-antigen "Vi," which improves resistance to host peroxide and host complement, contributes to the bacteria's more aggressive nature compared to that of other stains It helps bacteria hide from antibodymediated opsonization, which is a process that kills germs The bacteria produce typhoid toxin, which causes damage to cells and may lead to prolonged fever and disease in a way that non-typhoid stains cannot However, other strains of Salmonella, such as S bongori, contain just four pathogenicity islands and lack SPI-2 Salmonella typhi has adequate five pathogenicity islands for virulence, including SPI-1, SPI-2, SPI-3, SPI-4, and SPI-5 In contrast to other stains, they may go through a process called phase variation, which might change the expression of proteins and provide tolerance against immune responses What specific traits of the infectious agent made the issue possible in the first place? This syndrome is characterised by a high prevalence of asymptomatic infections, and while only 1% to 3% of carriers are able to transmit the disease to others, this is a crucial factor that causes illness in others Salmonella typhi or paratyphi is very harmful since it is immune to the host's immune response and may thus cause illness Due to the fact that the pathogens may be transmitted by faeces and saliva, contaminated foods have the potential to cause the sickness Mary is at danger of developing a disease due to her contact with the faeces of a range of animals, including cattle, chickens, and other birds In addition, she spreads the illness to others since she interacts with a big number of people at her place of work and because she handles a significant number of food items Is it possible that “Typhoid Mary” was badly treated by the public, and history in general? I have no doubt in my mind that Mary Mallon is connected in some way to the recent typhoid epidemic Mary has been given an unjust reputation by both those who lived during her time and later historians The investigation suggested that Mary was likely to blame for the salmonella typhoid outbreak, and further evidence confirmed that Mary was aware that she was sick but continued to go to work despite the fact that she maintained a slovenly level of hygiene in the workplace These two pieces of evidence strongly suggested that Mary was responsible for what had happened On the other hand, we are aware that salmonella typhoid is often an asymptomatic sickness that may spread disease, and that the disease may also be KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 transferred between animals and humans This is something that we must take into consideration In addition, the typhoid salmonella virus is particularly dangerous to humans because of their very high susceptibility Question 6: Define prion disease Prion illness is caused by a mutant form of a protein that is normally found in the body (PrPc) The prion is an infectious protein that has a shape similar to a sheet It is also known as the prion protein scrapie related protein (PrP sc) It is found in the brain and is responsible for the neurodegenerative disease known as transmissible spongiform encephalopathy, which affects humans, as well as a variety of other life-threatening neurodegenerative conditions that affect animals The source and transmission of disease Human-to-human transmission is possible if tainted meat or other products obtained from cattle are consumed For example, the use of surgical equipment that have been contaminated with infectious material may lead to the spread of disease in people If a person has the PrP c gene mutation codon 129 homozygous for methionine, they are more likely to acquire this disorder Transmission and proliferation of prions When prion protein interacts with regular protein, heterodimers are formed between the two types of proteins These heterodimers eventually change into homodimers of aberrant protein and amyloid Therefore, when regular PrPc comes into contact with PrPsc, it causes the normal PrPc to convert into the PrPc form and causes disease The accumulation of PrPsc may be harmful to the brain since it can lead to the production of fibrils and plagues PrPsc is a hydrophobic, spherical protein that may cluster with both PrPc and itself PrPc is attached to the cell membrane by phosphatidylinositol glycan As a result of PrP sc's interaction with PrPc, PrPc is altered to become PrPc that has a sheet When cells produced new PrP c, a chain of prion protein was built along anionic glycosaminoglycan on the cell surface This was how prions spread from cell to cell After then, there will be a break in the chain, and PrPsc will be freed As a result, neuronal cells import and store PrPsc Prion diseases in human The bulk of those who die with Kura disease are women, children, and the elderly, and its incubation period is unusually protracted Those that participate in cannibalism are more susceptible to contracting this illness Creutzfeldt-Jakob disease is a kind of sporadic human encephalopathy characterised by memory loss, inability to sleep, progressive weight loss, and deteriorating muscular coordination Patients typically perish away after 4.5 months of disease, at which time they have an average onset age of 65 years Prion diseases in animals Animals that are fed meat and bone meal from animals that are infected with prions are more likely to develop bovine spongiform encephalothapy It KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 results in strange behaviours, such as wobbling and falling, as well as a loss of weight and mortality within days HACCP approach to prevent prion disease Identify hazards: Consumption of items generated from animals with bovine spongiform encephalopathy (BSE), commonly known as creutzfeldtJakob disease, may transmit the prion disease to humans In addition to vaccines and growth hormones, other mechanisms of prion transmission include the contamination of surgical instruments and the injection of growth hormones In addition, prions that cause prion disease may be transmitted by the consumption of gelatine, milk products, and other things containing gelatine; however, this form of transmission is very rare If a person's PrP c gene has two copies of the methionine variation at codon 129, their likelihood of developing the disease is enhanced Consumption of scrapie-infected sheep carcasses or cattle carcasses with an unknown transmissible spongiform encephalopathy may result in bovine spongiform encephalopathy (BSE) in cattle Sheep are susceptible to the transmissible spongiform encephalopathy known as scrapie BSE may be transmitted from a mother sheep to her lambs through both placental secretions and the placenta itself Due to their genetic makeup, sheep are more susceptible to illness than other animals Identify critical control points: In order to protect human health, BSE-infected animals need to be removed from the food chain sterilisation of instruments in preparation for surgical usage Investigate whether or not PrPsc is present in immunizations and in the growth hormone that is injected It is prohibited to feed carcasses from cattle infected with crappie to other cattle, and euthanasia is required for sheep suffering from prion disease Establish critical limits: Prior to their usage in food production, cattle must undergo monthly BSE screenings Surgical instruments are needed to be sterilised both before and after use Before being provided to patients, every growth hormone injection and immunisation must pass prion testing Set corrective actions: Countries have the ability to place import restrictions on live ruminants, items derived from ruminants, and imports from nations that have animals afflicted with BSE Implementing BSE monitoring and determining whether animals have a high risk of contracting BSE A nationwide drive to eradicate scrapie as quickly as possible, including active testing on live animals and killing of infected animals, animal identification and tracking, and cleaning up affected areas It is optional to participate in the flock certification programme for scrapiefree sheep, which validates the flock's lineage Question 7: a) Patient A KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 Patient Guillain-Barre Syndrome is a consequence of campylobacterosis, which is often caused by the bacterium Campylobacter jejuni Immunotherapy is essential to treat the patient, and the plasma must be replenished to eradicate potentially harmful antibodies The infection that causes illness in males may be transmitted by the consumption of contaminated food, such as chicken meat or unpasteurized milk Additionally, he contracted the sickness by the fecaloral route, which means he acquired it from others by coming into contact with their hands, which contained the germs, or by touching surface objects Patient B Clostridium botulinum was the pathogen responsible for the infant botulism that Patient B developed Antitoxin administered intravenously in the form of botulism immune globulin might be used to treat the patient Baby bottles that have been touched by the germs and bacteria that people carry on their hands have the potential to make newborns ill There is a risk that the infant may put his hands in his mouth after accidently touching bacteria-filled canned items b) Patient A Campylobacter jejuni may infect humans, chickens, birds, cattle, cats, dogs, minks, rabbits, and other animals, as well as insects Often asymptomatic carriers of the bacteria, animals serve as a reservoir for the infection Within a few hours, a sample is collected from the chicken's faeces and then examined There is no excessive oxygenation or chilling of the specimen First, the specimen is isolated from the remainder of the sample using a 0.45-micron filter, and then it is improved using selective medium using microscopy to examine for gull-wing appearance in gramme stain, darting motility in fresh faeces, and faecal leukocytes Incubation at 37 or 42 degrees Celsius in an atmosphere containing percent carbon dioxide, such as a candle jar or a gas-producing apparatus The C jejuni hippurate hydrolysis test is positive On campy CSM agar, C jejuni looks black, but on campy CVA agar containing sheep blood, it becomes red C jejuni may be identified by the presence of oxidase and catalase, the absence of urease, growth in percent glycine, and nitrate reduction Patient B Therefore, the formation of Clostridium botulinum may be encouraged by any diet since its sources could produce spores As a result of the lack of oxygen in this environment, canned items, such as vegetables and mushrooms, are particularly susceptible to spoilage Products made from poultry, processed meats, and marine goods like smoked and salted salmon are also susceptible to contamination from the infection KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 For the purpose of testing for Clostridium botulinum, selective media such as M911 agar and Tryptone-sulfite-cycloserine agar may be used The bacteria will degrade, which will lead to precipitation around colonies on M911 agar and the creation of huge, flat colonies with back centres on Tryptone-sulfite-cycloserine agar Both of these results may be seen on the agar plates In order to determine whether or not C botulinum is present, immunological tests such as ELISA, which make use of multiplex antibodies, are carried out This method is very sensitive, does not cost too much money, and can be completed in a short amount of time, but it does not test for toxicity Methods based on nucleic acids, such as reverse transcription-PCR (RTPCR) and RNA microarray, are used to investigate C botulinum These methods are not only fast, low-cost, and sensitive, but they also detect just genes or gene expression without any harm The toxicity of C botulinum may be determined using bioassays performed on mice; however, these tests are time-consuming and expensive SECTION C Question 8: Describe why Listeria monocytogenes is considered a risk for the food industry even though it is relatively rare L monocytogenes-caused infections have a high death rate, ranging from 20 to 25 percent in adults and 50 percent in newborns Neonatal patients, pregnant moms, and the elderly constitute a vulnerable group that must avoid foods with a high risk of listeria infection Raw milk, soft cheese, raw sprouts, deli meats, and rock melon are examples of these foods The cost of treating illness in Australia is projected to be between $2 billion and $3 billion In addition, the cost of keeping food safe from pathogens in Australia is expected to vary between $0.13 billion and $1.5 billion This cost comprises sample testing, equipment design, inspection and packaging of items, as well as the cleaning and sanitation programme L monocytogenes can survive and thrive at temperatures as low as -80 degrees Celsius, and it is also highly resistant to salt and acid The bacteria cannot be controlled since it can survive at temperatures as low as -180 degrees Celsius and grow at temperatures as low as -0.40 degrees Celsius In addition, the formation of biofilm by bacteria adds to the difficulty of cleaning within the food industry L monocytogenes may be found in several settings, such as soil, water, plant matter, agricultural stuff, fish, amphibians, birds, and other animals Describe features and capabilities Listeria monocytogenes strains possess that makes it a persistent risk in the supply chain KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 Eukaryotic cells may be attached to the surface of L monocytogenes by the proteins Ami, LapA, and Lap B In addition to this, it has FbpA, which has the ability to attach itself to fibronectin found on host cells, as well as internalin J, which has the ability to bind to mucin found in the mucus layer In particular, it causes internalin A to adhere to and penetrate the cells of the human gut Internalin A makes it possible for bacteria to enter host cells by affixing itself to E-cadherin, a receptor protein found on enterocytes in the gut This method is also known as the Zipper mechanism By activating Met signalling, initiating the endocytosis process, or binding to GAGs, which forces Met activation in the absence of internalin B, internalin B makes it easier for bacteria to enter a wide variety of different cell types This is accomplished by internalin B subverting cell junctional endocytosis L monocytogenes produces peptidoglycan deacetylase and peptidoglycan Oacetylase, two enzymes that assist in modifying the bacterial cell wall in order to circumvent the humoral defences of the host, such as lysozyme Internalin C, Internalin K, and Lnt are three more compounds that inhibit the immune response of the host Internalin C dampens immune system Internalin K blocks the identification of cells necessary for phagocytosis The production of interferon by the innate immune system is controlled by Lnt, which is a transcription factor The protein known as listeriolysin O (LLO) provides pathogens with a helping hand in their escape from the phagosome Together with phospholipases (PlcA and PlcB) and the enzyme metalloproteinase (Mpl), which activate PlcB to facilitate bacterial entrance into the cytoplasm, it performs the role of a pore-forming toxin Within the thick cytoplasm of host cells, the movement of actin, which is found in host cell, is helped along by a protein on the cell surface called ActA The actin tails cause the bacteria to travel in a direction that is determined by chance, make contact with the cell wall of the host, and then form a protrusion that moves the cell that is next to them The process of cell-to-cell communication triggers an immune reaction, which in turn causes organ damage There is a paucity of knowledge regarding Listeria monocytogenes among both food manufacturers and consumers During the food preparation process, this company is not employing the correct technique in an acceptable way, which should eradicate any potential pathogens Listeria monocytogenes is unlike other bacteria in that it can withstand up to 2.5 M NaCl, can grow at 10C and live up to 45oC, and can tolerate a pH of 4.2 This may be unexpected in their situation In addition, consumers were unable to properly store or re-heat the food to destroy harmful bacteria The bacteria's development of biofilm aids in their resistance to washing and disinfection and guarantees that they continue to infest food products In actuality, 0.3 percent of 272,000 samples had a positive result for the bacteria KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 The development of pathogenic components, such as those resulting from mutation, allows bacteria to grow more harmful while escaping the immune system Question 10: Indicate the names, physical features, and transmission modes of these viruses Norovirus: The particles of a norovirus are spherical and they are not enclosed Noroviruses have a positive sense and only have one strand of RNA It is a member of the family known as Caliciviridae The size of its genome is 7.5 kilobase pairs, and the diameter of its particles ranges from 27 to 38 nanometers Only human beings are susceptible to infection The faecal-oral route is the mode of transmission for norovirus, which includes the consumption of contaminated food and drink, direct contact between infected individuals, the touching of contaminated surfaces, such as toilets, and the inhalation of aerosolized particles Rotavirus: It is a type III virus with two RNA strands and a spherical, nonencapsulated particle It is a member of the Reoviridae family The genome is 18 kbp in size and consists of 11 segments; the diameter of the particle is between 70 and 80 nm It starts in insects and eventually spreads to humans Rotavirus may be transmitted from person to person through the faecal-oral route, including consumption of contaminated food and drink, contact with contaminated surfaces, and even aerosols It may survive in the environment for nine to nineteen days and is extremely contagious Hepatitis A virus: The Hepatitis A virus is a positive single-stranded RNA virus that is classified as a category IV virus Its particles are spherical and they not have an envelope This virus is a member of the Picornaviridae family Its genome is 7.5kbp in size and particle size is 27-29nm diameter Only human beings are susceptible to infection The norovirus may be passed from person to person by excrement to the mouth, as well as through contaminated food and water, most notably raw or undercooked seafood Describe the diseases these viruses cause and any distinctive properties relevant to human disease Norovirus-caused gastroenteritis normally lasts for 48 hours and develops two to three days following introduction to the virus The digestive tract and salivary glands are the principal targets Among the symptoms of this disorder are vomiting with force, stomach discomfort, nausea, weariness, loss of taste, muscle aches, weakness, and a low-grade temperature There is an association between consuming salads and seafood and contracting norovirus This sickness does not elicit a powerful immunological response, and survivors not establish long-lasting immunity Norovirus is recognised using PCR or RT-PCR kits since it cannot be produced in a culture Rotavirus-caused gastroenteritis is often mild and self-limiting, despite being the greatest cause of infant mortality in developing countries The damaged organ is the intestines This sickness is characterised by nausea, vomiting, watery diarrhoea, and a low-grade temperature Rotavirus genomeNSP4 is capable of cause diarrhoea by means of a mechanism known KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 as pushing gut cell Ca2+-dependent transepithelial secretion The virus is able to survive pasteurisation and is resistant to disinfectants Immunization is the most effective method of rotavirus infection prevention The progression of hepatitis caused by the hepatitis A virus may take up to six weeks, and the sickness can last for eight weeks or even six months The severity of the condition's symptoms increases as the sufferer ages The organ that will be damaged is the liver Symptoms of this disorder include jaundice, fever, watery diarrhoea, vomiting, nausea, and abdominal pain The virus is very resistant to chemical disinfectants, although UV light, chlorine, and other substances may make it harmless Due to the virus's reproductive characteristics, it is difficult to culture the virus A person who contracts the virus will be immune to it for the remainder of their life Vaccination and maintaining high standards of personal and public hygiene are both effective strategies of preventing and minimising the spread of the disease why food-borne pathogenic viruses are usually not under surveillance as notifiable pathogens Also describe means to mitigate such viral illnesses especially in light of the Covid-19 pandemic Vaccines are often effective against the deadly viruses that may be transferred via food As a result of the fact that many food-borne pathogenic viruses cause only mild sickness that clears up in a matter of days, almost all of these viruses not cause serious illness in people Even though coronavirus has been found in the faeces of infected persons in certain tests, researchers are still worried that uncontaminated food might become contaminated and cause the virus to spread to other people However, there is no evidence to imply that coronavirus is an infection that is transmitted by food Disinfecting surfaces may help prevent the spread of norovirus The vast majority of disinfectants containing chlorine are successful in killing the virus Alcohol has the potential to completely eradicate the virus Twenty percent of Caucasians are born without a functioning fucosyltransferase enzyme, which gives them the ability to resist the binding of viruses The majority of people have mild symptoms and get well within forty-eight hours Vaccinations are the most effective way to prevent rotavirus Through immunisation efforts, the frequency of Rotavirus has significantly reduced across the board, in both industrialised and poor countries alike Despite the fact that rotavirus does not affect adults, it is a major contributor to infant mortality in developing countries Rotavirus only affects newborns The Hepatitis A virus may be contained by the use of vaccines, the elimination of sewage contamination in areas where shellfish are produced, and through improved public hygiene in general Question 11: a) KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 Diarrhea and a number of other illnesses that are not limited to the digestive system may be brought on by E coli Pathovars and pathotypes of E coli are to blame for a broad range of illnesses and deaths across the world As a result of this, pathogenic E coli has been the focus of a significant amount of research Research is conducted on a wide variety of topics, including but not limited to humans, animals, food, and the environment It is possible for the same sickness to appear differently in terms of symptoms, start, and prognosis depending on which pathotypes are currently present in the intestinal mucosa at any one time Epidemics are common in industrialised countries as well as underdeveloped ones, and they may be lethal in any setting These illnesses only need to be present in trace amounts for them to be a danger to the public's health It's possible that different pathotypes have varying infectious dosages There are ways that may be used on both a national and international scale to identify and monitor E coli outbreaks There is a deficiency of monitoring in many of the world's most disadvantaged nations Even while not all pathotypes have the same impact on public health, they all pose a risk of disease transmission and impede efforts to improve health outcomes This is true despite the fact that not all pathotypes have the same effect In this article, we take a look at some of the most recent and significant contributions to our understanding of the intestinal pathotypes caused by E coli It places an emphasis on recent happenings b) The pathogenicity island of certain bacteria is 35,600 bytes It's known as the LOE (LEE) For instance, E coli strains that are both enterohemorrhagic as well as pathogenous are included in this list Because bacteria cling tightly to enterocytes in affixing lesions, a signalling cascade damages the brush border and microvilli in effacing lesions, and ions are lost, the two types of lesions are unique Frequently, lesions that heal on their own occur Diarrhea may be caused by any of these Intimin and its receptor, the translocated intimin receptor, are both encoded by one of the type three systems, which has 41 open reading frames and five major operons (Tir) Transcriptional and posttranscriptional regulators on and off the pathogenicity island control LEE expression Transcriptional feedback inhibition, activation, and repression have been linked to a number of drugs by scientists Quorum sensing and gene transcription and translation are controlled by these molecules To understand how this lesion's transcription and expression are controlled, we conducted a brief overview of the extensive regulatory network involved It is this network that regulates gene replication and use c) Escherichia coli is a bacterium that has several pathotypes that are responsible for a broad variety of diseases In addition to the fact that KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 Escherichia coli is a vital component of the normal intestinal microflora of animals, including humans, it is also a potent pathogen Enteric illnesses, including diarrhoea and dysentery, are caused by at least six main pathotypes Extraintestinal infections, such as urinary tract infections and meningitis, are caused by pathotypes other than those responsible for intestinal infections - E coli virulence factors are encoded on plasmids, bacteriophages, transposons, and pathogenicity islands These genetic components may be passed across strains, creating new virulence combinations - E coli virulence factors interfere with cell signalling, ion secretion, protein synthesis, mitosis, and cytoskeletal organisation - E coli pathotypes have a wonderful mosaic genomic structure K-12 strain lacks 2,000 genes over 247 islands, like one pathotype The K-12 pathotype lacks a similar pattern Pathogenic E coli may have less than 0.53 GB K-12 DNA It's possible - Pathogenic E coli virulence factor-encoding genes are controlled by pathotype-specific regulators and 'housekeeping' regulators Pathogenic E coli has pathotype-specific regulators Commensal E coli lacks pathotypespecific regulators E coli is one of the few microorganisms that has the ability to change its behaviour in response to a broad range of environmental factors E coli is not only an important component of the normal intestinal microflora of mammals, such as humans and other animals, but it has also been used extensively as a cloning host in the field of recombinant DNA technology This is due to the fact that E coli is able to successfully transfer genetic material from one organism to another Nevertheless, E coli is not just a worker in the laboratory or a harmless resident of the digestive system; it is also a highly adaptable pathogen that often causes fatalities There are many different strains of E coli, and they are all to blame for the wide variety of illnesses that affect the intestines and other parts of the body Virulence factors, which have an effect on a range of biological processes, are responsible for the development of many disorders d) In most cases, Escherichia coli may be found living in the digestive systems of people and other animals There are several strains of E coli that are suitable for human consumption, and some of them may even be beneficial to the digestive system If an E coli strain is pathogenic, for example, it has the potential to cause diarrhea and perhaps sickness in areas of the body other than the intestines Diarrhea-causing E coli strains may be KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 disseminated by any combination of the following three routes of transmission: direct contact with ill animals or humans; ingestion of contaminated water or food; or any combination of the two The E coli bacteria are a heterogeneous community consisting of several distinct types of microorganisms The many pathotypes of pathogenic E coli are categorized under the same umbrella The term "diarrheagenic E coli" refers to a collection of six distinct pathotypes of E coli that have each been associated with the sickness This strain of E coli is also known as an enterohemorrhagic E coli, often abbreviated as EHEC, and a verocytotoxinproducing strain of E coli, abbreviated as VTEC, EHEC When an outbreak of a foodborne illness takes place, the focus of the majority of the media's attention is directed around a certain pathotype ... of outbreaks of foodborne illness that can be traced back to food that was cooked outside of the house is increasing all over the globe Technological changes KLA 604 FOODBORNE PATHOGEN PHU TIEN... vectors Foodborne diseases continue to challenge public health security despite improved hygiene, detection technology and in-depth knowledge of pathogens Despite an in-depth knowledge of pathogens,... of 272,000 samples had a positive result for the bacteria KLA 604 FOODBORNE PATHOGEN PHU TIEN TRAN 557234 The development of pathogenic components, such as those resulting from mutation, allows