Food Microbiology Finale

Campylobacter Pathogenesis

-As few as 500 cells CFUs may cause disease -Incubation period: 3-5 days -Duration of illness: 2-7 days; host cell invasion, mucosal damage and inflammation -Gastroenteritis, abdominal pain, bloody diarrhea, malaise, headache, fever -Motility and chemotaxis are essential virulence attributes -Pathogenesis still poorly understand-lack of good animal models

The fact that STEC Stx1 and Stx2 are encoded by phages makes treatment with antibiotics difficult because:

Antibiotics effective against STEC frequently induce the phage to go into the lytic cycle and result in increased expression of Stx genes, with higher levels of the toxins being produced (even when the pathogen is inactivated) making symptoms worse!!

Infectious dose estimates have been done in cattle. What is the estimated infectious dose for cattle?

As little as 1 microgram of brain tissue from a BSE-infected cow was needed to transmit the disease to a healthy cow

Virulence genes can vary in E. coli

Plasmids, Lysogenic bacteriophages, and Pathogenicity islands

How would you describe prions as infectious agents for Transmissible Spongiform Encephalopathies (TSE)?

Prions are normal mammalian cell proteins, commonly found all over the body but especially in nervous tissue. They play a role in long-term memory and maintaining normal nerve-cell physiology. When a normal cellular prion comes in contact with a disease-causing prion, its shape is induced to misfold. Now it can move on and misfold a different, healthy cell. Thus, the disease is amplified.

What have been the measures taken by governments to reduce vCJD?

Prohibitions on feeding rendered cattle by-products to cattle have been very effective

_______, a product in the production of Tempeh, was tested in the April 2012 outbreak of Salmonella, indicating it was the source of the pathogen

Rhizopus Starter culture

Reservoir for STEC/O157:H7 is

Ruminants, especially cattle

3 E. coli pathotypes

STEC (enterohaemorrhagic E. coli) EPEC (enteropathogenic E. coli) EAEC (enteroaggregative E. coli) ---EPEC and EAEC are common causes of diarrheal disease worldwide, causing persistent diarrhea in infants and AIDS patients

Two Outbreaks in 2015 associated with eating at Chipotle was caused by

STEC O26 This was a multistate Outbreak

What organism is primarily responsible for such beer (ale), what characteristics of the fermenting organism made this beer a popular drink even as far back as Ancient Egypt? Any disadvantage(s)?

Saccharomyces cerevisiae -Pronounced malty sweetness (somewhat to very bitter) -Low carbonation, Spoils easily -Top fermenting -Room Temperatures -High Metabolic rate -Good flocculation -Significant affect on flavor

Which microbe is primarily responsible for lager beer (the most popular beer style worldwide)? What are its key microbiological attributes that differentiate it from the one primarily responsible for ale?

Saccharomyces pastorianus -Dry and smooth, low to medium bitterness -High carbonation, good stability -Bottom fermenting -Cellar temperatures -Slow metabolic rate -Less flocculent -Less affect on flavor

Which vehicle was implicated in the Cyclospora outbreak in Iowa? Would one be surprised, based on what is known about vehicles for this agent?

Salad Mix imported from Mexico. Previous outbreaks in the U.S. have been associated with fruits and raw vegetables

What pathogen is responsible for the most foodborne deaths each year?

Salmonella (nontyphoidal)

What pathogen is responsible for the most foodborne hospitalizations each year?

Salmonella (nontyphoidal)

In April of 2012, _____ was identified in ______ food samples due to their indistiguishable Paratyphi B PFGE patterns. This pathogen caused ______

Salmonella Paratyphi B; Tempeh; Gastroenteritis

These Salmonella infections were linked to small turtles (NC was part of outbreak 1)

Salmonella Sandiego; Salmonella Pomona; Salmonella Poona

Transmission of Rotavirus

Spreads easily among infants and young children; fecal-oral route; Hands, objects, food, and water

Tempeh

Tender, white cake that is firm or chewy with a yeasty aroma Made of soybeans, grains, legumes, or seeds Fermented with Rhizopus starter culture Pasteurized b4 distribution Cooked and used as meat substitute

What is taking place during the maturation stage of brewing? What conditions are employed, and why?

The flavor and aroma mature for periods between 2 and 12 weeks Temp is reduced, and the yeast is "cropped" off the bottom or top of the fermenter

At the level of ingredients and microbiology, what are key similarities between beer and sake fermentations?

Use of Saccaromyces Cervisiae

As one of the papers describes, pregnant women who become ill with cholera have enhanced likelihood of fetal loss. What mediates fetal loss, and how does this differ from fetal loss that accompanies diseases via other ingested pathogens, such as listeriosis?

Dehydration leading to fetal hypoxia and acidosis

In investigating cholera outbreaks, which key route of transmission / landscape feature is one examining with special interest? Was this done in the Mexico outbreak?

Fecal-Oral, AKA drinking water

Symptoms of Salmonellosis

Fever Diarrhea Nausea and vomiting Abd cramps HA

Symptoms of Norovirus infection

Fever Watery diarrhea N/V Abd cramps HA Incubation period of 24-48 hours after ingestion

vCJD is extremely rare worldwide. About how many cases are reported (worldwide? in the US?) in this 2012 FDA report? When was the first case?

First Case was in 1996, since then only 217 ppl in the world have gotten the disease

Symptoms of Hep A

Flu-like illness Jaundice Severe Stomach Pains and diarrhea (in children) (3-6 deaths per 1000)

Symptoms of Toxaplasmosis

Flu-like symptoms; can be passed from mother to child; Usually only immunocompromised ppl show symptoms

Cronobacter sakazakii

Gram negative Extremely tolerant of dehydration Vehicle: dried infant formula At risk: neonates (esp. premature babies) Symptoms: sepsis, meningitis, necrotizing enterocolitis

Campylobacter is an antecedent to what syndrome>

Guillain Barre Syndrome (GBS) (paralysis)

What are some recommendations and policies implemented because of foodborne outbreaks?

HANDWASHING Moving where livestock go Being more careful with animals in open exhibits Better Maintenance

Vibrio spp

Halophiles Sensitive to temperature and salt concentration changes (causes them to change shape) Often die in the cold

What is the FDA "Bad Bug Book"?

Handbook of foodborne pathogenic microorganisms and natural toxins; Provides current information about the major known agents that cause foodborne illness; Intended for practical use, not a comprehensive scientific or clinical reference

What are the different types of Classic CJD?

Iatrogenic (acquired) - is the only transmissible form (through unintended exposure to infected tissue during medical events) ***Rare. Spontaneous - Accounts for ~85% of CJD cases, occuring in ppl with no obv. risk factors Familial - Disease passed down from parents to offspring (~10% of cases)

What pathogen caused an outbreak linked to Blue Bell Creameries Products

Listeriosis!

What is the most common setting for Norovirus outbreak

Long-term care facilities

Those with a defective FUT2 gene are termed

secretor-negative, making them resistant to the common GII.4 strain (but they can still be infected with other Norovirus strains)

Reservoir for EPEC and EAEC is

Humans

Salmonella is transmitted via what route

Ingestion via fecal-oral route

How is E. Coli O157:H7 transmitted?

Ingestion via fecal-oral route of fecally contaminated foods

Transmission of Norovirus

Ingestion via fecal-oral route: fecally contaminated foods, water, fomites, person-to-person, Particles can become aerosolized during vomiting episodes and contaminate surfaces (where the virus can remain infectious for weeks)

Foodborne Pathogens transmitted via food:

#1 - NoV #2 - Campy #3 - Salmonella #4 - C. perfringens #5 - Giardia

Clostridium perfringens

- Gram Positive spore former -Obligate anaerobe - Abundant in animal guts - Spore survive in cooked meat and poultry dishes - Require warmth and protein to grow - Has one virulence factor: CPE (C. perfringens enterotoxin) causes food poisoning

Some factors complicating Norovirus vaccine development

-Few human studies -Unknown duration of protective immunity -Lack of appropriate model systems -Antigenic variation among genogroups and genotypes -Antigenic variation within some genotypes -Unknown effects of pre-exposure history

Bacillus cereus

-Gram Positive Spore former - Psychrotroph -Can cause food poinsoning (diarrhea and vomiting) -Emetic syndrome caused by ingestion of starchy foods like potatoes and rice. but must grow in the food first. Onset begins within 30 minutes to 6 hours -Diarrheal syndrome onset takes 6 to 15 hours - Sickness only lasts for ~24 hours

STEC infections are complicated by

-Hemorrhagic Colitis -Severe renal and neurological sequelae, including Hemolytic uremic syndrome (HUS)

Campylobacter

-Obligate Microaerophile -Spiral Shaped, Gram Neg -Very fast -Grows between 32 and 43 C -Super sensitive to dehyrdation (Doesn't like air and drying out (survives longer in fridge) -Zoonotic agent (often infects chickens, turkeys, swine, cattle, sheep, water, milk) but favorite reservoir are birds Sporadic disease (4th most common foodborne disease in US) -Makes infected feel incredibly ill (gastroenteritis) Rarely causes death though. Antibodies against Campy also attack the myelin sheath of your peripheral nerves which can cause paralysis. Commonly infects young males Very low infectious dose (500) HUMANS ARE A DEAD END, DON'T OFTEN INFECT ONE TO ANOTHER!! Although, little reduction in number infections has occured

There have been how many outbreaks of vCJD

1, which is still ongoing (217 cases since 1996)

Steps to making Cheese

1. Homogenize & Pasteurize 2. Add starter culture 3. Coagulate casein micelles (at 32-33 C) Acidification Using lactic acid bacteria 4. Teat curds to separate whey (Rennet is added to milk to complete proteolysis) 5. Ripen/Cure Curds

2011 Cleveland County Fair E. coli O157:H7 outbreak

106 Cases (7 with HUS) 1 Death 11 Hospitalizations Due to environmental causes

NC State Fair petting zoo O157:H7 Outbreak 2004

108 cases (41 STEC) 15 cases of HUS

"Reinheitsgebot" or "German Beer Purity Law" is a very early (if not the first) example of precisely articulated food regulation. When about was this law implemented, and what does this entail?

1447; Made requirements for barley, hops, and water in making beer

How large (approximately) are the particles of norovirus? How would this compare to, say the size of an "average" bacterium?

20-40 nm Compared to the avg bacterium, which is around 2000 nm (2 micrometers)

E. Coli O157:H7 outbreak 2011 NC State Fair

27 reported cases (6 with HUS)

What is the case fatality rate for vCJD?

ALWAYS FATAL

What facility was the Iowa Cyclospora outbreak in 2013 traced to?

Taylor Farms de Mexico

How was the 2012 multistate outbreak of Campylobacter first detected? What does this suggest for outbreak detection (and control)?

A family contracted it (C. Jejuni) and it was detected in their stool

CaliciNet

A foodborne disease surveillance site Participants are Public health labs and food regulatory labs Typing of Norovirus by sequence analysis of Region B (2004-2006) and Region C & D (2007 - present)

Vibrio vulnificus (Vv)

95% of all seafood-related deaths Present in 50% of oysters in summer No correlation btw Vv and fecal coliform levels Infectious dose: >1000 CFU/g Illness: Septicemia, Gastroenteritis, Wound infections Increased risk with liver disease and alcoholism

Cyclospra

A cyst-forming, unicellular, coccidian parasite -Transmitted via fecal-oral route, but needs time after being passed in a bowel movement to become infectious (making it unlikely that it is passed from person to person directly) -causes prolonged and relapsing watery diarrhea (can last several weeks to months***) called cyclosporiasis -Time between infection and sickness is ~1 week

Dr. Sheppard differentiated between "viability" and "vitality" (or "brewing fitness") of the yeasts responsible for brewing beer. What do these terms reflect and how would they be measured? What other examples of "fitness" have we seen that are highly relevant in food microbiology?

A viable cell is capable of growth and reproduction under favorable conditions A Vital cell is a viable cell that demonstrates a strong and active metabolism A non-vital cell is a viable cell in a dormant, damaged, or injured state

In order to be infected with Norovirus, an individual must have

A functional Alpha-1, 2-fucosyltransferase (FUT2) gene, designated as secretor-positive

Steps to PFGE

A manner of surveying foodborne disease by: 1. Taking bacterial cells from agar plates 2. Preparing/digesting DNA plugs 3. Perform gel elctrophoresis 4. Gel staining so that DNA is visible under UV light, digital photo taken 5.DNA Fingerprint uploading to PulseNet 6. PulseNet search results are provided to the Enteric Microbiology Lab and the NC Communicable Disease Branch

Varient CJD

A progressively debilitating neurodegenerative disease, it Is the only CJD transmitted through food (Caused by the same agent as mad cow disease)

PulseNet

A type of foodborne disease surveillance that utilizes international molecular subtyping network for foodborne disease surveillance Participants subtype isolates by pulsed-field gel electrophoresis (PFGE) and multiple-locus variable-number tandem repeat analysis (MLVA) Participants include: State and local public health labs; CDC; USDA-FSIS; and FDA

Campylobacter infections can cause:

Autoimmune sequelae (e.g. reactive arthritis "Reiter's disease" - "patient can't see, can't pee, can't climb a tree")

What pathogen was associated with a kindergarten outbreak in Berlin, Germany, in 2007, causing food poisoning (emetic syndrome) after consuming rice pudding?

B. cereus (emetic toxin) Do to inadequate food handling

Causes of foodborne illness can be:

Bacteria, viruses, parasites, poisonous chemicals, or other toxins

Symptoms of O157:H7 infection

Bloody diarrhea Abd cramps Fever Symptoms w/in 2-4 days following exposure Hemolytic Uremic Syndrome (HUS) can lead to serious kidney damage and even death

STEC infections result in

Bloody or non-bloody diarrhea, and are caused by O157:H7 and other serotypes

Thermophilic Campylobacters

C. jejuni or C. coli, which are happiest in environments around 42 Centigrade

What way does the CDC use to track norovirus strains? What tool and approach is employed?

CaliciNet

Human Norovirus Statistics

Caliciviridae family Small - only 23 to 40 nm Nonenveloped RNA virus Segregated into 6 genogroups (most outbreaks are caused by GII.4 Strain) AKA Norwalk-like virus, Stomach flu

Most commonly identified pathogen in unpasteurized dairy product-associated foodborne outbreaks in the US?

Campylobacter

What is the implicated food source of vCJD? How is it believed to become contaminated?

Cattle Meat contaminated with BSE; contaminated by the feeding of cattle with rendered by-products of BSE-infected cattle

Yersiniosis

Caused by Yersinia enterocolitica -Psychrotrophic (tolerates cold and freeze-thaw) Resevoir: mostly pigs Most pts are children Symptoms: Fever, abd pn, diarrhea (often bloody) Incubation: 4-7 days Duration: 1-3 weeks Older children and adults have pn in LRQ resembling appendicitis Ass. joint pains, skin rash, bacteremia

What is the heat-stable peptide toxin that causes emetic syndrome and what microorganism produces it?

Cereulide; Bacillus cereus

Disinfectant registered as effective against NoV by EPA

Chlorine Bleach solution (5-10% solution)

First person reported to isolate and culture in pure form the lager yeast species named Saccharomyces carlsbergensis

Christian Hansen

When it comes to food and water, what can we (you, I, people in our community) do to minimize the risk for illness from these viruses?

Clean up surfaces; Disinfect surfaces; and Wash hands thoroughly with soap and water

How is Hepatitis A Virus (HAV) transmitted

Close personal contact; Consuming food or water containing HAV

The implicated dairy in the 2012 multistate outbreak of Campylobacter outbreak had a state (PA Dept of Agriculture)-granted permit to sell raw milk within the state (PA) . What special microbiological requirements were in place for such a permit? Based on the findings, would you suggest additional or alternative testing requirements?

Coliforms and standard plate counts and biannual milk culturing for bacterial pathogens

In order to inactivate NoV and other superbugs

Copper touch surfaces reduce hospital acquired infection rates

How to diagnose salmonella

Culture (Blood, MacConkey, XLD, Brilliant Green) Biochemical assays (Triple sugar iron agar slants; Lysine Iron agar slants; M broth and malonate; Jordon's tartrate) Molecular Serotyping PFGE MLVA upon request

What role does the NCSLPH have in foodborne outbreak investigations?

Detecting a possible outbreak with surveillance; and Laboratory testing of samples

Mechanisms of transmission of Salmonella Paratyphi B gastroenteritis

Direct consumption Cross-contamination in kitchens Person-to-person

What is foodborne illness?

Disease caused by consuming contaminated foods or beverages

ETEC

Enterotoxigenic E. Coli - massively contributes to diarrheal disease, and is leading cause of traveler's diarrhea

Where are the potential neutralization sites on Norovirus GII.4?

Epitope A, Epitope D, and Epitope E

Transmission of Toxaplasma Gondii

Foodborne (Meat in particular) Fecal-Oral

Vibrio parahaemolyticus (Vp) and Vibrio vulnificus (Vv)

Found in seafood, especially oysters (cause they are filter-feeders) (think raw oysters) Can cause rather unpleasant diarrhea Vv can kill those who already have liver disease or other conditions Both have a wide array of virulence factors, making them formidable killers Climate change is great for them! common in copepods, which feed on phytoplankton **Killed by cooking, steaming, and high pressure processing

The key to E. coli's versatility

Genetic heterogeneity -There are distinct sets of virulence genes in the different pathotypes- pathotypes differ from each other and from commensals

What pathogen is the leading cause of foodborne illness in the U.S. per year?

Norovirus (Nov)

For which of the three foodborne viruses of the greatest public health concern in the US are there vaccines? How efficient are these and who typically receives them?

Hepatitis A - Anyone 1 year old or older traveling to high incidence countries (at least a month before traveling); Children ages 2 - 18 yo who live in states where routine vaccination has been implemented due to high disease incidence; Men who have sex with men; People who use street drugs; ppl with chronic liver disease; ppl who work with HAV infected primates; members of households planning to adopt a child from a country where HAV is common

Norovirus is _______ to many sanitizers and disinfectants like alcohol based hand sanitizers, quaternary ammonium compounds, and bleach

Highly resistant

Human Noroviruses recognize:

Histo-blood group antigens (HBGAs) that are expressed on the surface of mucosal epithelial cells

Shigellosis

Incubation 1-2 days Initial symptoms of abd pn, watery diarrhea, and fever progresses into bloody diarrhea, fever, and pain Duration: 3 days to 2 weeks Infections localized to the colon (outermost intestinal wall, where it is at the surface, and is controlled) -Comet tail actin manipulation

Vibrio cholerae

Indigenous to marine and estuarine waters (halophile) Often colonizes zooplankton (copepods) There have been 8 pandemics since 1817 (most recent was 1996) Second leading cause of seafood related bacterial gastroenteritis in US Toxin-coregulated pilus = Cell clumping in intestine triggers production of Cholera Toxin - thanks to a filamentous, ssDNA bacteriophage

Transmission of Listeria Monocytogenes

Ingestion via environmentally contaminated foods Transplacental transfer

The toxin gene in Shigella dysenteriae:

Is not on a phage, like in STEC. It is designated STx, whereas the toxin in STEC are designated Stx. I know, big difference.

How did social media contribute to the investigation of the Cyclospora outbreak in Iowa outbreak? Did other media also contribute and if so, how?

It brought the issue to the forefront of the public's attention

Human foodborne prion disease is called variant "Creutzfeldt‐Jakob disease," or vCJD. Is this the only known form of human prion disease?

Kuru and CJD are the only human-specific TSE's that can be transmitted between ppl (Kuru is spread by eating brains :O So it's no longer transmitted)

Study of NoV has been hampered by:

Lack of efficient cell culture system

What foods are Norovirus associated with?

Leafy vegetables, fruits/nuts, or molluscs

Whey

Liquid runoff from cheese

In the CDC web site on hepatitis A vaccination (mentioned above), under "Who should get hepatitis A vaccine and when?" you will see that one category is "Men who have sex with men"—a true risk category for the CDC, often abbreviated MSM. Incidentally, MSM are also at relatively high risk for another food (water)borne pathogen with low infectious dose, Shigella (a Gram-negative bacterium closely related to E. coli; look it up under "Pathogen CV, Shigella"). What is going on?

MSM often engage in unprotected sex since there is no risk of pregnancy.

During Beer Primary fermentation

Maltose and amino acids ---> Yeast, ethanol, and CO2

First documented outbreak of STEC

Michigan 1982 in hamburger meat, the predominant serotype was O157:H7

Symptoms of listeriosis

Mild flu-like symptoms Fever Sepsis Meningitis Stillbirths, abortions

The Mexican cholera outbreak was contained relatively fast (first 13 weeks). What appears to have contributed to this?

More informed citizens, higher degree of seeking medical attention when signs were obvious. Also, there was a mobile microbiology lab used in the area to quickly diagnose and treat patients, interrupting transmission

Is there a vaccine for Norovirus?

NO

Who performed and published this investigation on the risk factors for fetal loss among pregnant women with cholera in Haiti? Anything unusual about the affiliation of the first author and several others?

National Bioethical committee of the Ministry of Public Health and Population of Haiti

NORS

National outbreak reporting system - Helps to assess the national burden and temporal trends of outbreaks; Aids in identifying priority settings and population for interventions; Assisted in characterizing outbreaks (pathogen, setting, mode of transmission)

Affected populations (with cholera) in the La Huasteca region included indigenous tribes with their own languages. What was done for effective public health & water safety outreach to these populations?

National radio messages on prevention of diarrhea are being carried out in multiple languages

Transmissible spongiform encephalopathies (TSES)

Neurodegenerative diseases, leading to a sponge-like appearance of the brain tissue

Changes at the NC State fair due to E. Coli O157:H7 outbreak 2011 NC State Fair

New traffic patterns that effect where livestock are housed and shown Location of animals w/in buildings changed Entrances and Exits Food vendor locations Signs More HAND WASHING STATION SIGNS Nighttime lighting

Are there methods for detection of the agent in food products?

No

What pathogen is responsible for the most foodborne illnesses each year?

Norovirus

What are common pathogens of foodborne illness?

Norovirus Salmonella C. perfringens Campylobacter S. aureus

Would you expect tissues such as cattle brain, eyes, spinal cord and small intestine to be diverted as "offal" for pet foods?

Not anymore due to laws regulating rendered by-products from being sold as offal

Cholera Toxin

One A subunit (responsible for adenylate cyclase activation = increases intracellular cAMP, leading to diarrheal symptoms) 5 B subunits (bind to G protein receptors on mucosal cells)

What was the evidence that the V. cholerae strains from the Mexico outbreak were similar to those from Haiti and other Caribbean outbreaks?

PFGE and virulence gene amplification demonstrated the strains were identical to the strain causing outbreaks in Haiti, DR, and Cuba

How is vCJD detected in humans? Are there methods for early detection?

Patient history, clinical symptoms, EEG's, MRI's But the most definitive way of diagnosing any TSE is microscopic examination of brain tissue (but this is a postmortem procedure)

What is the blue in blue cheese?

Penicillium roqueforti (a fungus)

The paper mentions that in PA raw milk dairies increased from 26 in 2002 to 153 in 2013. What are the possible reasons, and how do you think the food safety community should respond?

People are freaked out by pasteurized milk, think it is bad for their imm. system

What laboratory tools does the NCSLPH utilize in foodborne outbreak investigations?

PulseNet- PFGE & MLVA CaliciNet - Norovirus typing by sequence analysis

It is mentioned that only 23% of the patients in the Mexico outbreak required hospitalization; this plus other disease metrics (e.g. incidence of severe dehydration, death) suggested milder disease than observed in Haiti and other Caribbean outbreaks, even though the strains were quitter similar. What may be going on?

Quicker access to resources/ faster diagnosis and more awareness of the disease

What type of nucleic acid do these viruses have? What does this mean for PCR-based detection?

RNA; So there must be retrotranscription step before realtime PCR can happen and amplify the DNA

Aedin's Law (Due to NC State Fair petting zoo O157:H7 Outbreak 2004)

Regulations for exhibitions housing animals intended for physical contact with the public, regarding: -Permitting -Education -Enhanced maintenance of animal facilities -Transitional entrances and exits -HAND WASHING STATIONS

Vibrio cholerae

Relies on toxin produced by CTXf bacteriophage to cause cholera. Can exist without it, causing diarrhea. Grows in victim's gut Shed in abudance to make others sick wihen sewage gets into drinking water

What were the major symptoms in the cholera outbreak, Mexico (La Huasteca region) 2013?

Severe dehyrdation or death from acute watery diarrhea

Symptoms of Rotavirus infection

Severe watery diarrhea, vomiting, fever, abd pn, dehydration

STEC

Shiga Toxin producing E. Coli (type O157:H7 and other serotypes) - Has impressive acid tolerance (helps pass through the stomach) - Can infect ruminants without making them sick - Has low infectious dose for humans - Called "hamburger E. coli" but uses all kinds of vehicles - Uses Shiga toxin - Transmitteed via fecal-oral route - Toxin causes HUS in 5 to 10% of those who get ill (creating life long kidney damage)

Indian Shigella

Shigella boydii

Shigella species that produces Shiga toxin, causing bacillary dysentery

Shigella dysenteriae (worked with by Dr. Kyoshi Shiga)

Shigella species that predominates developing nations

Shigella flexneri

African Shigella

Shigella flexneri -Leads to Reiter syndrome (Reactive arthritis)

Shigella species that predominates industrialized nations

Shigella sonnei

In infected cattle, which parts of the animal are most likely to contain the agent?

Skull Brain Trigeminal ganglia Eyes Tonsils Spinal Cord Dorsal root ganglia Distal ileum

Two types of shiga toxins found in STEC

Stx1 (99% identical to STx of Shigella dysenteriae) -Has 3 subtypes that differ in toxicity (Stx1a is wild phenotype) Stx2 (only 55% of amino acid sequence shared with STx) -Has 7 subtypes (Stx2a is wild phenotype) -More frequently implicated in hemolytic uremic syndrome (HUS)

What are the key points from the brief posted file "Cryptosporidum blog item and update"?

The parasite Cryptosporidium was responsible for the U.S.'s biggest waterborne outbreak ever, forcing utilities nationwide to make improvements in water treatment and monitoring. The thing is, that crypto still lurks in ponds, streams, day care centers, and swimming pools, still occasionally making waves of diarrhea victims. Once pooped out, a tough outer shell allows them to survive in dirt, water, and food for 18 months or longer. Once contracted, there exists no drug to simply make it go away. Babies and immunocompromised are at large risk

How did the pathogen's (Cyclospora) unusual attributes contribute to the investigation of the outbreak? What would have been different if, for instance, Salmonella or STEC were involved?

The persistence of symptoms (watery diarrhea for weeks) allowed for eventual detection and treatmetnt for many patients. If it had been Salmonella or STEC, symptoms would have gotten much worse much quicker

Several prions responsible for TSEs in animals (including meat animals) are known. How is the prion responsible for vCJD related to prions causing "mad cow" disease (BSE), chronic wasting disease in elk and deer, and scrapie of sheep and goats? For which of these agents is there evidence of TSE transmission to humans?

They are all TSEs that exist in animals, while vCJD and BSE (mad cow) seem to be caused by the same agent. Chronic wasting disease in elk/deer, and scrapie of sheep/goats is not transmissible to humans

Curds

Thick cheese

Shigella

Unicellular, rod shaped, faculative intracellular pathogen that gets inside an infected intestinal cell in a vacuole, then escape into the cytoplasm and multiply by manipulating actin filaments into polymerizing around it (making a comet tail) moving it around the cell, to the edge, and into another cell. (Listeria does this too) Low infectious dose Acid tolerant Human reservoir Virulence plasmid necessary to make you ill (lost readily in lab, which sucks cause resistance to antibiotics is often on the same plasmid) Symptoms: Days of diarrhea (possibly bloody), fever, and cramps (but will rarely kill you) Attacks refuge camps and day care centers All Ready to eat foods are possible vehicles Water and person to person routes too

Successful culture of HuNoV was accomplished in 2016 by:

Using enteroid cells (Epithelial cells that develop crypt-villus differentiation)

Vibrio parahaemolyticus (Vp)

Vehicles: Seafood (raw oysters) Uses Thermostable direct hemolysin to form pores, leading to fluid loss and ion efflux Leading cause of shellfish-associated illness in US Most common in Japan and SE Asia In response to external stress, goes into viable but nonculturable (VBNC) state, metabolizing cells, but forms no colonies. Symptoms: Watery diarrhea, Abd. cramps, N/V, HA, fever, chills Incubation: within less than 24 hours of ingestion Duration: 2.5 days Infectious dose: >10E+06 microbes, but dose can be lowered by antacid consumption!!!!!! Serious infections found in immunocompromised pts (septicemia)

VBNC state

Viable but nonculturable state - Occurs in response to external stresses -Altered cell morphology (coccoid cells) -Intact membranes and metabolizing cells, but no colonies -Resuscitation MAY be achieved

FDA requirements to inspect salad mix, iceberg lettuce, romaine lettuce, green leaf lettuce, red cabbage, green cabbage and carrots

Voluntary action in response to Cyclospora outbreak in Iowa

Basic beer ingredients

Water Malted Barley Hops Yeast

Investigators can use _____ to get more detailed info about the DNA fingerprints of pathogenic strains

Whole Genome Sequencing

What is the future/present of foodborne outbreak investigations?

Whole Genome Sequencing

Norovirus occurs more frequently among:

older adults, young children, and immunocompromised patients

Incubation period, time course, symptoms of vCJD?

~10 years incubation period Avg age of onset is 28 yrs old for vCJD Avg age of onset is 68 yrs old for Classic CJD Duration: Median 14 months for vCJD Median 4.5 months for Classic CJD Symptoms: Psychiatric problems - depression Progressive neuro signs like unpleasant sensations, difficulty with coordination, forgetfulness (late), diff. speaking (late). Pts are increasingly unable to care for themselves until death occurs