Microbiology - Chp. 15: Foodborne & Waterborne Bacterial Diseases

digestive system is composed of

gastrointestinal (GI) tract; oral cavity, pharynx, esophagus, stomach, small intestine, and large intestine & accessory digestive organs; salivary gland, liver, gallbladder, and pancreas

digestive system defenses

chewing – dislodges microbes from epidermal and tooth surfaces, mucins, lysozyme, lactoferrin, IgA, and defesins, low pH in stomach

digestive system defenses in the intestines

mucus that traps bacterial cells, IgA antibody, shed surface epithelium, peyer’s patches, MALT (mucosa-associated lymphatic tissue)

appendix

resupply the lost microbial species needed to repopulate the colon

digestive system varies in the ________ and _______ of bacterial species present throughout its length

numbers, diversity

species number and diversity

very high in the oral cavity, drop to low  in the stomach, increase again in the small intestines, explode in the colon

the digestive system’s microbiotas is _____ and ______

large, diverse

the roles of the gut microbiome

digest fibers, influence multiple physiological functions, optimize immune reactions, influence brain development, affect the body’s response to medical treatments such as cancer chemotherapy

________ or ____ can alter bacterial species and numbers

medications, diet

dysbiosis

iinduce anxieties and depression, alter the risk of developing asthma or diabetes, trigger inflammatory bowel diseases, initiate colorectal cancer, influence how fat or thin an individual might be

_____ _____ causes pain and tooth loss in affected individuals

dental caries; streptococcus and Corynebacterium colonize on the enamel surface of tooth to form a biofilm, a succession of highly organized gram-positive and negative species interact to form dental plaque

plaque bacteria, such as Streptococcus mutans, S. sobrinus, and Lactobacillus ferment sugar to

produce acid that attack minerals in the tooth’s enamel – demineralization, tooth abscess by white blood cells to fight infections inside the tooth

caries

susceptible tooth with a buildup of plaque, dietary carbohydrates, usually in the form of sucrose, acidogenic bacteria, streptococcus mutans, S. sobrinus

__________ _______ can arise from bacteria in dental plaque

periodontal disease

periodontal disease

if dental plaque is left on the teeth from a lack of proper oral hygiene, the biofilm below the gumline can result in swollen and tender gums (gingiva)

gingivitis

caused by porphyromonas gingivalis; secretes toxins and enzymes capable of directly or indirectly injuring the tissues surrounding and supporting the teeth, preventable and treatable through professional cleaning to remove the plaque

periodontitis

caused by Treponema denticola, Tannerella forsythia, and Fusobacterium nucleatum, bone resorption, periodontal ligament loss occur; loosen the teeth and tooth loss

periodontitis complication;

infective endocarditis, cardiovascular disease, infective arthritis, premature babies

choose a WRONG match

dental caries: demineralization of tooth by acid secreted from bacteria

gingivitis: direct invasion of the gingival tissue

periodontitis: occurs bone resorption and loss of periodontal ligament

all of the above are correct

gingivitis: direct invasion of the gingival tissue

mumps

by mumps virus under paramyxoviridae, enlarged jaw tissues arising from swollen salivary glands, the parotid glands, spread by respiratory droplets and contacts with contaminated objects (fomites), less contagious than measles or chickenpox

orchitis;

sterility is not common, MMR vaccine only available for prevention

an inflammation of the GI tract

intoxications are illnesses in which bacterial toxins are ingested with food and water, infections are illnesses in which live bacterial pathogens are ingested and grow in the body

the incubation period is the time between:

consumption of contaminated material & appearance of symptoms

____ _________ can be the result of enterotoxins

food poisoning

staphylococcal food poisoning

the result of enterotoxins, a key reservoir; nasal sneeze by a food handler, boils and abscesses on the skin, organisms are identified by mannitol salt agar and Gram staining

staphylococcal food poisoning symptoms

abdominal cramps, nausea, vomiting, prostration, and diarrhea, incubation period:1-6 hours

toxins are often consumed in protein-rich foods;

meat and fish, dairy products – cream-filled pastries, or salads such as egg salad, refrigeration is not a safeguard against growth of S. aureus with temperature range of 8^oC to 45^oC

the enterotoxin

causes gastroenteritis for several hours, the most heat resistant exotoxin

Tx

supportive treatment for dehydration and electrolyte replacement

_______ can be a life-threatening foodborne intoxication

botulism

botulism caused by

clostridium botulinum; spore-forming, obligately anaerobic, gram-positive bacillus mostly in home canned foods, type E is associated with most cases of foodborne transmission

flaccid paralysis

symptoms develop 12 to 72 hours after ingesting the food, blurred vision, slurred speech, respiratory arrest, neurotoxin that inhibits the release of the neurotransmitter acetylcholine, preventing the contraction of muscles

botulism treated by

antitoxins and life-support systems like ventilators; antibiotics are of no value, prevented by heating foods before eating them for at least 10 minutes over 90ºC

wound botulism

occurs when toxins are produced in anaerobic tissue of wounds with C. botulinum; treated by penicillin

infant botulism

most common form of botulism in the US; it occurs when infants ingest endospores, commonly with honey causing floppy baby syndrome – lethargy, poor muscle tone, mechanical assisted ventilation, treated by Penicillin

botulinum toxin

used in botox; dystonia as in strabismus, blepharospasm, stuttering, unrelieved blinking, musician’s cramp, temporary relief of facial wrinkles and frown lines

bacillus cereus food poisoning

heat-stable toxin; common in cooked grains, like rice, cause substantial vomiting 0.5 to 6 hours after ingestion, recover after 2 days, fluid replacement is standard treatment

bacillus cereus food poisoning causes

diarrhea or vomiting, infections usually occur from eating contaminated cooked grains, the spore-forming, gram positive rod, enterotoxin; meat, poultry, or vegetables, cause watery diarrhea but little vomiting 6 to 15 hours after ingestion, vomit 6 to 15 hours after ingestion

flaccid paralysis can be caused by ___

clostridium perfringens

bacillus cereus

clostridium botulinum

staphylococcus aureus

clostridium botulinum

inflammatory gastroenteritis

diarrhea, vomiting, a fever but no blood in the stool

invasive gastroenteritis

fever, diarrhea or vomiting, dysentery; the passage of blood and mucus in the feces

bacterial gastroenteritis often produces an inflammatory condition;

cholera, E. coli diarrhea, clostridium difficile infections, vibriosis, intestinal anthrax

cholera caused by

vibrio cholerae; motile, aerobic, gram-negative curved rods, enter the intestinal tract in contaminated food, such as raw oysters, or in contaminated water, extremely susceptible to stomach acid, most infections are asymptomatic

if high numbers of cholera are ingested,

enough survive to colonize the small intestines, noninvasive cells secrete cholera toxin; rice-water stools, dehydration causes blood thickened, anuria, and the sluggish blood flow to the brain leads to shock and coma

cholera treatment

antibiotics, oral rehydration, vaccines using dead V. cholerae are available, preventable by clean water and food

E. coli diarrhea

a facultative anaerobic, gram-negative rod, follows the fecal-oral route

enterotoxigenic E. coli (ETEC)

cells adhere to the epithelium of the small intestines

ETEC produces

2 enterotoxins; heat-labile enterotoxin similar to cholera toxin, heat-stable enterotoxin, causes traveler’s diarrhea, common symptoms; vomiting, cramps, nausea, and a low-grade fever

enteropathogenic E. coli (EPEC) & enteroaggregative E. coli (EAEC);

potentially fatal form of diarrhea in infants, where sanitation conditions are poor, watery diarrhea resulted from effacement of microvilli caused by the binding of E. coli cells to the mucosa, fluid replacement is critical

pseudomembranous colitis;

clostridium difficile; anaerobic, spore-forming, G(+) rod, at risk – older adults and people who take antibiotic, clindamycin that inhibit normal flora, which hypercolonize C. difficile

pseudomembranous colitis toxins

enterotoxin: causes fluid loss and diarrhea, cytotoxin: causes mucosal injury to pseudomembranous colitis, which leads to toxic megacolon and rupture

pseudomembranous colitis Tx;

stop the antibiotics, fluid replacement, metronidazole, vancomycin, fecal transplantation

choose a WRONG match

cholera: rice water stools

ETEC: Traveler’s diarrhea

EPEC: effacement of microvilli

pseudomembranous colitis: overuse of antibiotics to hypercolonize C. botulinum

pseudomembranous colitis: overuse of antibiotics to hypercolonize C. botulinum

parahemolyticus Vibriosis;

vibrio infections by species other than Vibrio cholerae, the leading cause of seafood-associated gastroenteritis along the Atlantic Coast; vibrio parahemolyticus, curved, gram-negative, halophilic rod in warm ocean water

parahemolyticus vibriosis

enterotoxin after 24-hour incubation period, causes acute abdominal pain, vomiting, watery diarrhea, and nausea – self limited

vulnificus Vibriosis by V. vulnificus

the most virulent to people who consumed oysters and clams along the Gulf coast; fever, nausea, severe abdominal cramp, at risk; immunocompromised patients, liver disease, low stomach acid

vulnificus Vibriosis by V. vulnificus exposure of an open wound to contaminated water;

become systemic and necrotic skin lesions and cellulitis, prompt treatment; empirical antibiotics, aggressive debridement, and general supportive care

choose a WRONG match

listeriosis: dairy food to cause meningitis

parahemolyticus vibriosis: sea-food associated gastroenteritis

vulnificus vibriosis: primary sepsis in the liver disease patients

all of the above are correct

all of the above are correct

invasive Gastroenteritis

typhoid fever, salmonellosis, shigellosis, hemorrhagic colitis, campylobacteriosis, listeriosis, yersiniosis

typhoid fever

salmonella enterica serotype typhi; a motile, nonspore-forming, facultative anaerobic, gram-negative rod, humans are only host, remain alive for long periods in water, sewage, and certain foods exposed to contaminated water

salmonella enterica serotype typhi transmitted by

flies, food, fingers, feces, and fomites (non-living objects) acid resistant, which survives even in stomach, incubation period: 5-21 day

typhoid fever invades

submucosa in the small intestine, causing deep ulcers, bloody stools, abdominal pain, rose spot, macrophages engulf the organisms and spread to a systemic illness

typhoid Fever recoverers are

carriers and continue to harbor and shed the organisms for a year or more; food handlers can be carriers of disease, 15% fatal, vaccination needed if travels to the endemic area

nontyphoidal salmonellosis

several nontyphoidal serotypes of S. enterica associated with a gastrointestinal disease, S. enterica serotype enteritidis, S. enterica serotype tyhphimurium

nontyphoidal salmonellosis common with

beef, poultry, eggs after incubation of 6-48 hours, fever, nausea, vomiting, diarrhea, abdominal cramping, and dehydration but no blood invasion, self-limited after 3-7 days, antibiotics not recommended

shigellosis

shigella sonnei; gram (-) rods, outbreaks in daycare centers

shigella dysenteriae; deadly epidemic dysentery in developing country, humans are primary reservoir

100 cells enough to

infect via Fecal-oral route, person to person, transmitted by flies, water, eggs, vegetables, shellfish, and dairy products, bacterial dysentery is fatal; fever, abdominal pain, and bloody mucoid stools

shigellosis recoverers are

carriers for a month or more, oral replacement needed, clean hygiene essential, antibiotics for shigellosis reserved for severe cases

enterohemorrhagic E. coli (EHEC)

produces a toxin called Shiga toxin that blocks protein synthesis, another name is Shiga toxin producing E. coli (STEC) – acid tolerant

another name for enterohemorrhagic E. coli (EHEC)

shiga toxin producing E. coli (STEC) – acid tolerant; E. coli O157:H7, naturally exist in the intestines of healthy   cattle as a reservoir, contaminated fresh, bagged spinach, normal flora in healthy cattle as a reservoir

enterohemorrhagic E. coli (EHEC) transmitted form

contaminated produce and undercooked ground beef, soils, and water, swimming in contaminated water parks, drinking water inadequately chlorinated, acid-tolerant, 100 cells enough to infect

enterohemorrhagic E. coli (EHEC) symptoms

incubation period: 1-8 days, hemorrhagic colitis, diarrhea, abdominal cramps, mild fever, and bloody diarrhea, common in young children and elderly

enterohemorrhagic E. coli (EHEC) hemolytic uremic syndrome (HUS)

5 – 10% of patients with STEC in children, life-threatening, toxin-containing cells clog the glomerulus in the kidney, which induce kidney failure, caused by O157, O26, O104

hemolytic uremic syndrome (HUS) supportive care only

fluid rehydration; rbc transfusions, kidney dialysis, but no antibiotics due to risk to increase HUS

campylobacteriosis; ampylobacter jejuni

microaerophilic, curved, gram-negative rod, reservoir; intestines of warm-blooded animals including dairy cattle, chickens, and turkeys

cmpylobacter jejuni transmitted via

the fecal-oral route through contact or exposure to contaminated foods (unpasteurized dairy products, or raw milk) or water, incubation period: 2-7 days

campylobacteriosis invasion of the mucosa leads to

inflammation, invasive disease, and occasional mild ulceration, broad spectrum of symptoms from mild diarrhea due to production of an enterotoxin to severe gastroenteritis with bloody diarrhea due to a cytotoxin

guillain-Barre syndrome

complication of campylobacteriosis – 1/1,000, a rare immunoreactive sequela after the diarrhea, paralysis by peripheral nerve damage

listeriosis; listeria monocytogenes

a facultative anaerobic, Gram-positive rod, normally found in animal GI, in soil and water, psychrotrophs – grow in refrigerators, contaminated with delicatessen cold cuts, cheese, milk, poultry, and seafood, incubation period: 2 to 6 weeks

listeriosis invasive infection & clinical presentation

healthy individuals – no symptoms, pregnant women – miscarriage, stillbirth, listerial meningitis – 20% fatal; high fever, headache, stiff neck, confusion, loss of balance, or convulsions

listeriosis treatment and prevention

appropriate antibiotics, prevent by thoroughly cooking raw food from animal sources and washing hands, knives, and cutting boards

yersiniosis; yersinia enterocolitica

motile at room temperature, gram-negative rods, pigs are asymptomatic carriers, transmitted by consuming food that came in contact with infected domestic animals, raw or undercooked pork products, or by ingesting contaminated water or raw milk

yersiniosis; yersinia enterocolitica incubation period

1-2 day, symptoms: fever, diarrhea, and abdominal pain, lasts 1 to 3 weeks, antibiotics unnecessary unless the illness becomes systemic

_____ _____ ______ can be spread person to person

peptic ulcer disease

vastric ulcer disease; helicobacter pylori

microaerophilic, gram-negative curved rod, gastric ulcer disease in 2% out of half the world’s population who are infected with

helicobacter pylori produces

urease, which in turn produces ammonia, ammonia neutralizes acid in that area of the stomach, allowing the bacteria to survive, the ammonia, and an H. pylori cytotoxin destroy mucous-secreting cells, producing gastritis

helicobacter pylori; 1% of infected individuals develop

stomach cancer, treatment; amoxicillin, tetracycline, or clarithromycin, along with omeprazole

choose a WRONG match

typhoid fever: rose spot on the skin

shigellosis: bacterial dysentery

hemorrhagic colitis: E. coli O157:H7

campylobacteriosis: raw milk

yersiniosis: Yersinia pestis

helicobacter pylori: can cause gastric cancer

yersiniosis: Yersinia pestis

rotavirus gastroenteritis

naked, circular-shaped ds RNA virion, the deadliest form in children, occur in oct to april in US, einter diarrhea, transmitted by fecal-oral route, diarrhea, vomiting, and chills, infection does not guarantee immunity treated with oral hydration and electrolytes, vaccine; rotateq, rotarix

norovirus infection

the most common nonbacterial gastroenteritis in adults, naked, icosahedral +ss RNA virus in Caliciviridae family, transmitted by fecal oral route, occur in summer as “summer diarrhea,” incubation period 15-48 hours

enterovirus infections

small, +ss RNA virions of picornaviridae, coxsackie virus, hand, foot, and mouth disease; affects infants and young children in spring to fall, fever, poor appetite, malaise, and a sore throat, a rash on palms and soles, recover in 7 to 10 days, no treatments available

enterovirus infections;

enteric, cytopathogenic, human host, and orphan (a virus without a famous disease), infantile diarrhea

hepatitis A virus

nonenveloped +ss RNA virus of Picornaviridae, transmitted by the fecal-oral route, raw shellfish – clams, oysters, primarily replicates in the gastrointestinal tract then transported to the liver for its major replication

hepatitis A virus

jaundice, relapse commonly occur in up to 20% of cases, life-long immunity acquired, no chronic infections

if exposed to HAV,

administer hepatitis A immune globulin within 2 weeks of infection, no treatments available except rest, vaccines; havrix, vaqta, twinex – both HAV & HBV

hepatitis E virus

+ss RNA virus, transmitted by fecal-oral route, affects immunocompromised individuals and pregnant women, 30 % mortality, no evidence of chronic infection, no treatments available

choose a CORRECT match

hepatitis A virus: relapse common in 20% of cases

HAV: vaccines available

HEV: affects pregnant women

HEV: 30% mortality

all of the above are correct

all of the above are correct

hepatitis B virus

a partially double stranded DNA virus, consists of hepatitis B core antigen (HBcAg), hepatitis B envelope antigen (HBeAg), hepatitis B surface antigen (HBsAg), transmission; contact with blood, semen, saliva, sexually transmitted

hepatitis B virus symptoms

fever, fatigue, appetite loss, nausea, vomiting and dark urine, jaundice, 10% of patients develop chronic infection; cirrhosis, hepatocellular carcinoma, immunized by hepatitis B vaccine especially for health professionals

hepatitis B virus treated with

interferon alpha, HBV immune globulin for needle-stick exposure