Microbiology GI – Flashcards

Unlock all answers in this set

Unlock answers
question
Anaerobic Normal flora of the upper respiratory tract
answer
Peptostreptococcus
question
Anaerobic Normal flora of the upper respiratory tract
answer
Veillonella
question
Anaerobic Normal flora of the upper respiratory tract
answer
Actinomyces
question
Anaerobic Normal flora of the upper respiratory tract
answer
Fusobacterium
question
Aerobic Normal flora of the upper respiratory tract
answer
Streptococcus pyogenes
question
Aerobic Normal flora of the upper respiratory tract
answer
Streptococcus pneumoniae
question
Aerobic Normal flora of the upper respiratory tract
answer
Staphylococcus aureus
question
Aerobic Normal flora of the upper respiratory tract
answer
Neisseria meningitidis
question
Aerobic Normal flora of the upper respiratory tract
answer
Haemophilus Influenzae
question
Aerobic Normal flora of the upper respiratory tract
answer
Moraxella catarrhalis
question
Aerobic Normal flora of the upper respiratory tract
answer
Members of enterobacteriaceae
question
Oral cavity normal flora associated with acute endocarditis
answer
HACEK
question
Oral cavity normal flora associated with subacute endocarditis
answer
Viridans Streptococcus
question
Normal flora of the stomach
answer
Helicobacter
question
Normal flora of the stomach
answer
Lactobacillus
question
Normal flora of the stomach
answer
Streptococcus
question
Normal flora of the small intestine
answer
Peptostreptococcus
question
Normal flora of the small intestine
answer
Porphyromonas
question
Normal flora of the small intestine
answer
Prevotella
question
Major reservoir of bacteria in the body
answer
Large intestine
question
Normal flora of the large intestine
answer
Bacteroides
question
Normal flora of the large intestine
answer
Bifidobacterium (probiotic bacterium)
question
Normal flora of the large intestine
answer
Clostridium
question
Normal flora of the large intestine
answer
Eubacterium
question
Normal flora of the large intestine
answer
Enterococcus
question
Normal flora of the large intestine
answer
Escherichia coli
question
Cariogenic biofilm formation and lactic acid production can lead to dissolution of tooth enamel known as a dental caries, which bacteria is mainly responsible
answer
Streptococcus mutans
question
Swelling, erythema, gum recession, bone resorption
answer
Periodontal disease
question
Early colonizers of periodontal biofilm formation
answer
Gram + bacteria
question
late colonizers of periodontal biofilm formation
answer
Gram - bacteria (Tannerella forsythus, Aggregatibacter actinomycetemcomitans, Porphyromonas, Fusobacterium, Treponema)
question
Bacterial products leading to inflammatory response in periodontal disease
answer
Endotoxins and volatile sulfur products
question
Necrotizing ulcerative gingivitis and periodontitis (trench mouth, vincents angina)is caused by what bacteria
answer
Synergistic infection involving: Treponema vincentii, Prevotella intermedia, Fusobacterium nucleatum
question
This bacteria causes gastritis and gastric ulcers
answer
Helicobacter pylori
question
Sharp burning pain emanating from the abdomen
answer
Gastritis
question
Gram (-), vibrio with 6 polar-sheathed flagella (highly motile)
answer
Helicobacter pylori
question
Contains urease
answer
Helicobacter pylori
question
Provides alkaline environment by converting urea into ammonia
answer
Helicobacter pylori
question
Acting as an antigen patients show elevated levels of IgA and IgG
answer
Urease, H. pylori
question
Uses flagella to move through mucus to stomach lining and resist effects of peristaltic flushing
answer
Helicobacter pylori
question
Adherence to epithelial cells using an adhesin which is the same molecule found on human O type RBC
answer
Helicobacter pylori
question
Humans are primary reservoir, person to person transmission through fecal oral or oral fecal, worldwide incidence is high
answer
Helicobacter pylori
question
Diagnosis using endoscopic exam for lesions and biopsy specimen
answer
Helicobacter pylori
question
Diagnosis using noninvasive urea breathe test (UBT)
answer
Helicobacter pylori
question
Can Diagnosis through ELISA but endoscopy may be required for confirmation
answer
Helicobacter pylori
question
Treat with antibiotics plus acid suppressors
answer
Helicobacter pylori
question
Bacteria causing acute bacterial diarrhea
answer
Salmonella, Shigella, Escherichia, Campylobacter, Yersinia, Clostridium difficile, Vibrio cholerae,
question
Frequent loose, watery stools, abdominal cramps and pain, fever, bleeding, dizziness from dehydration
answer
Acute bacterial diarrhea
question
Transmitted by contaminated food, treatment is variable, most cases are self limiting
answer
Acute bacterial diarrhea
question
Gram (-) bacilli with flagella, member of enterobacteriaceae
answer
Salmonella
question
More than 200 serotypes based on O and H antigens
answer
Salmonella
question
Obstruction of small intestine leads to colonization of bacterium from the large intestine
answer
Blind loop syndrome
question
Cause most cases of salmonellosis
answer
variants Paratyphi, Hirschefeldii, Typhimurium
question
Salmonella in reptiles
answer
Variant Arizona hinawii
question
Salmonella responsible for typhoid fever
answer
Variant typhi
question
Ability to grow in M cells of pyers patches and nonactivated macrophages
answer
Salmonella
question
Pathogenicity islands contain adhesins responsible for entry and possible systemic spread, also contains an endotoxin
answer
Salmonella
question
Ingestion of organism>absorbed to epithelial cells in terminal SI>penetrate cells and migrate to lamina propria>multiply in lymphoid follicles>PMNs confine infection to GI>inflammtion causes release of prostaglandins>hypothalamus>Inc cAMP>fluid secretion resulting in diarrhea
answer
Salmonellosis, Salmonella
question
Spread of bacteria not confined to GI leading to prolonged disease and focal infections (osteomyelitis, pneumonia, pulmonary abscess, menigitis)
answer
Septicemia, Salmonella
question
First week of infection contains no diarrhea>2nd week contains intracellular replication and prolonged bacteremia>Weeks 3-5 include includes infection of biliary system, rose colored spots and diarrhea
answer
Typhoid fever, Salmonella
question
Complications include intestinal perforation, bleeding, and pneumonia
answer
Typhoid fever, Salmonella
question
One of the more common bacterial diseases in the US, caused by contaminated food (beef, poultry, eggs, dairy)
answer
Salmonellosis, Salmonella
question
Large animal reservoir of: cattle, chickens, rodents, reptiles
answer
Salmonellosis, Salmonella
question
Large number of bacteria are required for symptomatic disease so person to person transmission is not common
answer
Salmonellosis, Salmonella
question
Human carriers (gall bladder) are the only known reservoir
answer
Typhoid fever, Salmonella
question
Major route of transmission is through water contaminated with human feces, low infectious dose so person to person spread is common, usually acquired in endemic areas of developing countries
answer
Typhoid fever, Salmonella
question
Diagnosis from isolation of fecal matter, serological tests determines O antigen, differentiate from shigella includes: motile, bile resistant, H2S and gas production from fermentation
answer
Salmonellosis, Salmonella
question
Blood cultures during first 2 weeks of illness
answer
Septicemia and Typhoid fever, Salmonella
question
Treatment includes: replenish fluid loss, antibiotics are not used because they prolong the carrier state and do not shorten course of illness
answer
Salmenollosis, Salmonella
question
Unlike salmonellosis treatment involves use of antibiotics
answer
Septicemia and Typhoid fever, Salmonella
question
Vaccine for poultry is used and has reduced incidence
answer
Salmonella
question
Vaccine available and effective, especially in children in locations where incidence is high
answer
Typhoid fever, Salmonella
question
Salmonella and typhoid fever are reportable diseases
answer
True
question
Non motile, no H2S or gas production during fermentation, inhibited by high concentrations of bile
answer
Shigella
question
H. pylori is a member of Enterobacteriaceae
answer
False
question
Salmonella is a member of Enterobacteriaceae
answer
True
question
Shigella is a member of Enterobacteriaceae
answer
True
question
Well known species of Shigella
answer
S. dysenteriae
question
Well known species of Shigella
answer
S. flexneri
question
Well known species of Shigella
answer
S sonnei
question
Virulence factor contains a shiga toxin, ability to induce phagocytosis grow within and kill host
answer
Shigella
question
Shiga toxin is an enterotoxin
answer
True
question
Demonstrates both cytotoxic and neurotoxic activity
answer
Shiga toxin
question
A-B toxin (A binds to ribosome inhibiting protein synthesis) damaging the mucosa and villi leading to bleeding and heavy secretion of mucus
answer
Shiga toxin
question
Lesions develop in the intestinal tract in stages: penetrate>spread>kill>histology shows micro ulcers or gross ulcers with sloughing epithelium
answer
Shigella
question
Symptoms vary from asymptomatic to severe with abdominal cramps, blood and pus in stool. Disease runs its course in about 10 days
answer
Shigellosis-bacillary dysentery, Shigella
question
Humans are natural host, low infectious dose with high communicability, spread by direct fecal oral or mechanical route. Majority of cases occur in children 1-10 yoa
answer
Shigella
question
In the US and other developed countries this is the most common spp of Shigella
answer
S. sonnei
question
Diagnosis by loose stool containing mucus and bright red blood
answer
Shigella
question
Fresh passed stool specimens for isolating bacterium, if stored too long, acid in feces will inhibit growth
answer
Shigella
question
Negative Triple iron sugar test (TSI)
answer
Shigella
question
Treat dehydration and fever, all infections treated with antibiotics
answer
Shigella
question
Shigella is a reportable disease
answer
True
question
Member of Enterobacteriaceae, normal flora of intestinal tract, cause many opportunistic and nosocomial infections
answer
Escherichia
question
Small gram (-) rod with fimbriae and flagella
answer
Escherichia
question
O, H, K antigen determined for epidemiological studies
answer
Escherichia
question
Infects small intestine, 2 plasmid enterotoxins causing fluid and electrolyte loss, similar to cholera toxin
answer
ETEC
question
Primary cause of travelers disease
answer
ETEC
question
Aka shiga toxin
answer
EHEC
question
Infects the large intestine producing 2 cytotoxins, type III secretion system introduces bacterial products directly into gut epithelial cells
answer
EHEC
question
Verocytotoxins
answer
EHEC
question
May cause a variety of illness including watery diarrhea followed by bloody diarrhea with little or no fever and Hemolytic uremic syndrome
answer
EHEC
question
Most common serotype causing HUS
answer
O157:H7
question
Acute renal failure and thrombocytopenia with highest incidence in children <5 yoa
answer
HUS
question
Foods of animal origin are probably the major source of human infection, mainly hamburgers
answer
EHEC
question
Epidemic infantile diarrhea with non blood stool
answer
EPEC
question
Dysentery with scant, blood stools with mucus and PMNs like shigella, however, does not produce a toxin
answer
EIEC
question
Infection occurs in adults and nosocomial infections in infants
answer
Escherichia
question
Transmission is not person to person, rather via contaminated food or water
answer
Escherichia
question
Most common strains of Escherichia producing disease in developing countries
answer
EHEC
question
In addition to ground beef, infection includes contaminated water, unpasteurized milk, fruit juice, uncooked vegetables, fruits
answer
EHEC
question
If suspected diagnosis stool cultures on MacConkey-sorbitol agar
answer
HUS
question
diagnostic test used to differentiate EHEC from normal flora Escherichia
answer
MacConkey-sorbitol agar
question
This medium contains bile salts that inhibit growth of gram (+) bacteria, pH indicator reveals fermentation of sorbitol
answer
MacConkey-sorbitol agar
question
Does not ferment sorbitol
answer
EHEC
question
Assay for enterotoxins or presence of toxin genes on plasmids, serology and pulse field gel electrophoresis for epidemiology
answer
Escherichia
question
Antibiotic resistance is a problem, spread of R factors is common among strains of species
answer
Escherichia
question
Treatment for short term illness does not recommend antibiotics, long term illness does and infants (except for one strain) do recommend antibiotics
answer
Escherichia
question
Antibiotics increase risk of developing HUS
answer
EHEC
question
Most common cause of bacterial diarrhea in the US
answer
Campylobacter jejuni
question
Gram (-), vibrio like, wings of a seagull
answer
Campylobacter
question
Includes LPS, enterotoxin, flagella; bacteremia in some patients.ulcerated, edematous, and bloody invasion of mucosal surface, infiltration of lamina propria with neutrophils, eosinophils, and mononuclear cells
answer
Campylobacter
question
Infection varies from asymtomatic to acute gastroenteritis with liquid and/or bloody diarrhea. In older compromised individuals disease may appear as acute bactermia with inflammatory bowel and cause death
answer
Campylobacter
question
20-40% of Guillain-Barre syndrome (GBS) cases are preceded by this bacteria
answer
Campylobacter
question
Unknown mechanism causing acute paralysis
answer
Guillain-Barre syndrome
question
Flora of mammals (pigs, cattle, dogs, cats, rabbits, and birds including poultry), contaminated water and other foods cause large outbreaks especially in developed countries
answer
Campylobacter
question
Campylobacter is a reportable disease
answer
False
question
Individuals at risk are those who are exposed to a large number of organisms and lack gastric acids
answer
Campylobacter
question
Fecal oral and person to person transmission occur but it is unlikely to be transmitted by food handlers
answer
Campylobacter
question
Diagnosis: Use dark field microscopy and Campy BAP
answer
Campylobacter
question
Specialized media containing antibiotics to inhibit other fecal organisms
answer
Campy BAP
question
Grow best at reduced oxygen and 42C
answer
Campylobacter
question
Treatment includes rehydration with electrolytes for mild cases, antibiotics for more sever cases
answer
Campylobacter
question
Causes GI tract disease found in cooler areas of the US
answer
Yersinia enterocolitica, Yersinia pseudotuberculosis
question
Causes sever abdominal pain sometimes mistaken for appendicitis
answer
Yersinia enterocolitica, Yersinia pseudotuberculosis
question
Gram (+), endospore forming, obligate anerobe
answer
Clostridium difficile
question
The use can clindomycin, ampicilin, and cephalosprins may lead to pseudomembranous colitis
answer
Clostridium difficile
question
May be resistant to antibiotic, gastric acid inhibitors may predispose over growth of bacterium
answer
Clostridium difficile
question
2 enterotoxins, A and B, cause necrosis in the wall of the intestine
answer
Clostridium difficile
question
source of infecting strain can be endogenous or exogneous, risk factors include antibiotic exposure, old age, female, and impaired intestinal motility
answer
Clostridium difficile
question
Incidence varies with degree of hospital incidence with bacterial spores
answer
Clostridium difficile
question
Other than Clostridium difficile, this bacteria may cause antibiotic resistant colitis
answer
Staphylococcus aureus
question
Use a combination of test for presumptive diagnosis
answer
Clostridium difficile
question
Treatment includes avoiding drugs that slow intestinal motility or broad antibiotics and substitute antibiotics
answer
Clostridium difficile
question
Probiotics and donor stool translplants are attempted
answer
Clostridium difficile
question
Large number of spores shed in stool, especially in hospital environment
answer
Clostridium difficile
question
Short, gram (-) curved rod with polar flagella
answer
Vibrio cholerae
question
Natural habitat is marine or brackish water but can survive in fresh water
answer
Vibrio cholerae
question
A-B type ADP ribosylating toxin with 5 B and 2 A subunits
answer
Vibrio cholerae
question
TCBS agar
answer
Vibrio cholerae
question
Toxin binds Gm1 gangliosides on host mucosal cells allowing A1 subunit to inhibit systhensis of G1 protein used to regulate adenylate cyclase which controlls cAMP levels. This leads to electrolyte imbalance and diarrhea
answer
Vibrio cholerae
question
Rice water diarrhea
answer
Vibrio cholerae
question
Fecal oral transmission, human spread is increased by the bacterias ability to survive in fresh water as well as salt water
answer
Vibrio cholerae
question
Human caries serve as reservoirs (2 type): convalescent sheds for several months after illness, chronic carrier is usually an older individual carrying the organism in the gall bladder with intermittent shedding
answer
Vibrio cholerae
question
Theory of permanent reservoir in estuaries and marshes in tropical and subtropical areas of the world (India, bangladesh, gulf coast of US)
answer
Vibrio cholerae
question
Most cases involve contaminated seafood from gulf waters
answer
Vibrio cholerae
question
killed, whole cell vaccine does not provide long term immunity but is effective for travelers
answer
Vibrio cholerae
question
Vibrio cholerae is a reportable disease
answer
True
question
Acute bacterial diarrhea with vomiting (food poisoning)
answer
Staphylococcus aureus, Bacillus cereus, Clostridium perfringens
question
Found in: custards, sauces, cream pastries, processed meats, chicken salad, ham that have been contaminated and left unrefrigerated for a few hours, heating food after toxin prevention may not prevent disease
answer
Staphylococcus aureus
question
2 clinical forms of food poisoning producing to enterotoxins: 1 emetic form and 1 diarrheal form
answer
Bacillus cereus
question
Incubation period of ~4 hr. Heat stable enterotoxin found in fried rice and vegetables.
answer
Emetic form, Bacillus cereus
question
Incubation of ~16-18 hours. Heat-labile enterotoxin associated with abdominal cramps and diarrhea. Found in contaminated meat and vegetables
answer
question
Gram (+) spore forming, naturally present in soil
answer
Bacillus cereus
question
Non enveloped with a double layered protein capsid resistant to drying, detergents, and pH
answer
Rotavirus
question
Virus has a wheel like appearance
answer
Rotavirus
question
One of the proteins contains a viral enterotoxin. Group A are the major cause of of this virus worldwide
answer
Rotavirus
question
Viral disease severe in infants <2 yoa
answer
Rotavirus
question
Major cause of death in children <5 yoa
answer
Rotavirus
question
Cause of infant diarrhea (Human Infantile Gastroenteritis)
answer
Rotavirus
question
Watery diarrhea, vomiting, fever, abdominal pain. Asymptomatic in adults
answer
Rotavirus
question
Cell culture is not performed because it is difficult to cultivate virus from clinical specimen
answer
Rotavirus
question
Virus spread primarily by fecal oral route. Asymptomatic shedding may occur, fomites can remain infectious at room temp for many months
answer
Rotavirus
question
Outbreaks in N America occur in fall, winter, spring. Worldwide occur throughout the year
answer
Rotavirus
question
Immunity after infection of this virus only lessens severity of subsequent infection. Protective immunity requires IgA in the gut lumen
answer
Rotavirus
question
Virus is inactivated by chlorine and contains to live oral vaccines
answer
Rotavirus
question
The initial vaccine for this virus was taken off the market due to intussesception
answer
Rotavirus
question
No anti viral treatment available. Replenish fluid and electrolytes. Do not give fruit juices or soda due to high glucose content
answer
Rotavirus
question
This virus has been known to bind blood group antigens in animal excretions
answer
Norovirus
question
More data is needed to conclusively call this a zoonotic virus
answer
Norovirus
question
Most important non bacterial cause of acute gastroenteritis for all ages, worldwide
answer
Norovirus
question
Sometimes referred to as stomach flu, although not related to influenza
answer
Norovirus
question
Many different strains of this virus prevent lifelong immunity. Dehydration occurs in the very young, elderly, and weakened immune systems
answer
Norovirus
question
Cruise ships are particularly vulnerable due to crowding, frequent passenger changes, and difficult decontamination in short time periods
answer
Norovirus
question
Highly contagious virus spread through fecal oral, fomites, inhalation, direct contact. Day cares are a major source of infection
answer
Norovirus
question
There is a vaccine and antiviral drugs for Norovirus
answer
False
question
Star like morphology
answer
Astroviruses
question
Of the 8 types of this virus, Type 1 is most commonly seen worldwide
answer
Astroviruses
question
Infection is seen primarily in children <1 yoa suggesting lack of maternal antibodies. Incidence mostly in tropical climates during winter months
answer
Astroviruses
question
There is a vaccine and antiviral drugs for Astroviruses
answer
False
question
Symptoms include release of liver enzymes and classic icteric symptoms: jaundince, dark urine, and clay colored stool
answer
Hepatitis
question
Most common cause of acute hepatitis
answer
HAV
question
Most common cause of chronic hepatitis
answer
HCV
question
Waterborne hepatitis viruses
answer
HAV, HEV
question
Blood borne hepatitis viruses
answer
HBV, HCV, HDV
question
Blood borne hepatitis viruses
answer
HBV, HCV, HDV
question
Blood borne hepatitis viruses
answer
HBV, HCV, HDV
question
Hepatitis that persists >6 mth is termed chronic
answer
True
question
Liver damage due to hepatitis is not due to cytopathic effect bur rather immune mediated attack on infected hepatocytes
answer
True
question
There is only 1 serotype of HAV
answer
True
question
Complete recovery from this form of hepatitis is seen 99% of the time
answer
HAV
question
Complete recovery from this form of hepatitis is seen 99% of the time
answer
HAV
question
Lab diagnosis of this virus is done by ELISA with early detection of anti___ IgM
answer
HAV
question
Transmission of this virus is through fecal oral route (fresh or salt water in shellfish or contaminated sewage), sharing utensils, sexual, poor hygiene, and overcrowding
answer
HAV
question
Virus causes mild disease in children, abrupt onset in adults, worldwide incidence with no seasonal incidence
answer
HAV
question
Virus contains a protease that cleaves an important component of the IFN signaling pathyway reducing type 1 interferon respone
answer
HAV
question
Antibody protection for HAV is lifetlong
answer
True
question
If HAV vaccine is given within 2 weeks of exposure to illness there is an 80% efficacy in prevention
answer
True
question
There is no antiviral treatment, however, Ig given within 2 weeks of exposure can prevent clinical illness
answer
HAV
question
Chlorine treatment does not kill HAV
answer
False
question
Viral core contains DNA, RT, core antigen, and a specific glycoprotein
answer
HBV
question
Dane particle
answer
HBV
question
Viral envelope contains an immunogenic surface antigen which binds and block the action of neutralizing antibodies
answer
HBV
question
Serological diagnosis by profile of antibodies against core or surface antigens
answer
HBV
question
Histological hallmark is a ground-glass hepatocyte cytopathology
answer
HBV
question
Presence of this antigen indicates an active HBV infection
answer
HBeAg
question
Key diagnostic test for HBV infection is detection of this antigen
answer
HBsAg
question
Appearance of this indicates decreased HBV replication
answer
Anti-HBe
question
Transmission for this virus includes: neonatal from mothers blood, sexual activity, IV drug use. At risk regions include China, Alaska, Africa, Pacific Islands
answer
HBV
question
In the USA prevalence of this virus is highest in asians, african americans, and native americans
answer
HBV
question
Single serotype, vaccine includes the surface antigen
answer
HBV
question
Requires HBVsAg to cause infection
answer
HDV
question
Smallest human pathogen known so far
answer
HDV
question
Viral RNA has ribozyme activity
answer
HDV
question
Transmission through blood, semen, vaginal secretion. May lead to chronic infection including enchephalopathy and massive hepatic necrosis
answer
HDV
question
No Ig or vaccine available but HBV vaccine will indirectly prevent against this virus
answer
HDV
question
Acute infection is usually asymptomatic and may go undiagnosed. This sets up a chronic infection and predisposes the liver to cirrhosis and carcinoma
answer
HCV
question
Long term consequences are more severe than HBV
answer
HCV
question
Transmission: blood, needles, tattoo, piercing, circumcision, less frequently sex and perinatal
answer
HCV
question
Treat with alpha-2 interferon alone or in combination with Ribavirin for large increases in ALT serum levels
answer
HCV
question
Hemolytic anemia is a side effect of Ribavirin, therefore Hg levels should be monitored
answer
HCV
question
Identified as the causative agent for non-A, non-B hepatitis
answer
HCV
question
Enteric non-A, non-B
answer
HEV
question
Spread through fecal oral route and contaminated water, cases in Japan resulted in consumption of deer or pig meat
answer
HEV
question
Mortality rate higher than HAV especially for pregnant women in 3rd trimester
answer
HEV
question
Most problematic in developing countries: India, pakistan, nepal, burma, north africa, mexico
answer
HEV
question
Infection clinically indistinguishable from HAV and self limiting. Recently there has been development of an ELISA for Igm
answer
HEV
question
Diarrhea, cramps, fever, leukocytosis, inflammation, necrosis
answer
Clostridium difficile
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New