MICRO – Microbiology Test Answers – Flashcards
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| What are characteristics of pathogenic strains of Neisseria that are useful for identifying them in the laboratory? |
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| diplococcus with oxidase enzyme activity and fastidious growth requirements |
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| Lipid A causes what symptoms? |
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| fever and disseminated intravascular coagulation (DIC) |
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| Neisseria is |
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| the only genus of Gram-negative cocci that regularly causes disease in humans |
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| What is TRUE about Neisseria gonorrhoeae? |
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infected woman are often asymptomatic; the gonococci stick to epithelial cells via fimbriae and capsules; it causes disease in humans only; the gonococci secrete a protease that destroys secretory IgA. |
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| Among the areas of the female genital tract, what is NEVER infected with Neisseria gonorrheae? |
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| the vagina |
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| The major damage caused by Neisseria meningitidis is a result of? |
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| the release of the Lipid A component of lipooligosaccharide(LOS) into the tissues, triggering serious symptoms. |
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| what is a diagnostic for Neisseria meningitidis? |
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| the presence of Gram-Negative diplococci in phagocytes of the CNS |
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| Members of the Enterobacteriaceae can be distinguished from each other by? |
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| motility and the ability to ferment lactose |
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| What virulence factors do all proteobacteria share? |
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| Lipid A |
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| What is TRUE about Neisseria meningitidis? |
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| humans are the only natural carriers, up to 40% of the population ar carriers, it often causes meningitis, transmission is via respiratory droplets. |
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| a lung specimen from a pneumonia patient contains Gram-negative bacilli. Laboratory test results on the bacteria show they are nonmotile coliforms with a capsule. Which pathogen is the likely cause of the pneumonia? |
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| Klebsiella |
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| What coliform is the most common cause of non-nosocomial UTI's? |
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| Escherichia coli |
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| Serratia is a coliform that? |
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| produces red pigment when grown at room temp |
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which of the following pairs are mismatched? a)coliform Enterobacteriaceae- rapid lactose fermenters b)noncoliform opportunistic Enterobacteriaceae- Proteus, Morganella c)noncoliform Enterobacteriaceae- non-lactose-fermenters d)nonpathogenic Enterobacteriaceae- Salmonella, Shigella e)coliform Enterobacteriaceae- opportunistic pathogens |
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| d)nonpathogenic Enterobacteriaceae- Salmonella, Shigella |
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| Several cases of severe, nonbloody diarrhea with fever and abdominal pain have occurred among a number of people who ate at the same restaurant. Public health officers find a food sample containing noncoliform, nonmotile Gram-negative bacteria capable of metabolizing urea. The "food poisoning" resulted from contamination with? |
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| Yersinia |
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| Shigellosis can be differentiated from salmonellosis by? |
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| the presence of nonmotile noncolifroms in bloody diarrhea |
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| what is the causative pathogen for bubonic and pneumonic plague? |
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| Yersinia pestis |
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| What bacteria requires heme for its growth? |
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| Haemophilus |
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| a young woman has a pelvic infection. a specimen contains bacilli that are bile salt tolerant, as shown by growth on a bile-esculin agar plate. Her infection is likely caused by? |
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| Bacteroides fragilis |
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| What is true about Pasteurella? |
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| it is fastidious in its growth and must be cultivated on blood or chocolate agar, it is nonmotile, it is oxidase positive, and humans are typically infected via animal bites |
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| Cat scratch disease is caused by? |
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| Bartonella henselae |
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| Bordetella pertussis, the pathogen responsible for whooping cough, causes diseases by? |
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| interfering with the action of the ciliated epithelial cells of the trachea |
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| Rsistance of Pseudomonas to a wide range of antibacterial agents is partly due to its? |
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| ability to form biofilms |
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| What disease can be prevented by vaccination? |
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| typhoid fever |
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| Legionnaires' disease is diagnosed by? |
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| fluorescent antibody or other serological diagnostic procedures |
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| What is true about Coxiella? |
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| it prefers an acid environment, it was once thought to be a virus, it produces an infective body similar in structure and function to endospores produced by some Gram- positive species, it is an obligate intracellular parasite that grows within phagolysosomes. |
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| What is FALSE regarding Coxiella? |
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| it must use its host's ribosomes. |
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| Wh is the causative pathogen of Q fever? |
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| Coxiella burnetii |
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| How do Prevotella differ from Bacteroides? |
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| They are sensitive to bile |
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| What toxins produce by Bordetella pertussis results in the accumulation of excess mucus in the trachea? |
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| pertussis toxin and adenylate cyclase toxin |
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| Hemolytic uremic syndrome is caused by? |
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| Escherichia coli O157:H7 |
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| A cystic fibrosis pt develps a severe respiratory infection that resists treatment with standard ABX. A specimen from the lungs is greenish in color and contains aerobic motile Gram-negative bacilli. The patient is probably infected with? |
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| Pseudomonas aeruginosa |
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| What is the characteristic lesion of Yersinia pestis? |
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| a bubo |
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| What is the antimicrobial agent of choice for treating Bacteriodes infections? |
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| metronidazole |
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| What bacteria was formerly classified in the same family as Neisseria? |
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| Moraxella |
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| What organism produces concentric wavelike patterns due to swarming cells when it is cultured on agar? |
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| Proteus |
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| Q fever? |
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| inhalation of dried bodily fluids of infected animals |
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| UTI with kidney stones? |
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| Proteus |
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| Meningitis in infants 3-18 months old |
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| Haemophilus influenzae |
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| Chancroid or soft chancre? |
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| Haemophilus ducreyi |
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| Abortion in infected goats and sheep, but not in infected humans? |
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| Brucella |
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| Pelvic inflammatory disease (PID) |
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| Sexually transmitted |
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| Legionnaires' disease |
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| inhalation of bacteria in aerosols |
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| Bubonic plague |
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| the bite of an infected flea |
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| Salmonellosis? |
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| contamination of food by inoculation from cracking an egg |
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| Trench Fever? |
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| transmitted by human body lice |
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| T/F Some scientists believe that Shigella may actualy be a strain fo E. coli that has become oxidase positive? |
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| FALSE |
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| T/F Humans are the sole hosts of Salmonella typhi. |
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| True |
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| T/F Lipid A causes disseminated intravenous coagulation (DIC) |
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| TRUE |
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| T/F Enterobacteriaceae are rarely pathogenic. |
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| FALSE |
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| T/F Gonococcal infections result in lifelong immunity against Neisseria gonorrhoeae? |
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| FALSE |
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| T/F Intravenous ceftriaxone is the drug of choice for treating meningococcal meningitis? |
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| TRUE |
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| T/F By controlling the geneticexpression of Vi and H antigens, Salmonella evades the host's immune system and manages to survive.. |
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| TRUE |
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| T/F MacConkey agar is selective for Haemophilus influenzae. |
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| FALSE |
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| T/F Haemophilus ducreyi is transmitted sexually. |
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| TRUE |
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| T/F Moraxella is a common cause of bacteremia. |
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| FALSE |
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| T/F Coxiella burnetii is transmitted to humans mainly via the bite of infected tick vectors. |
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| FALSE |
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| T/F Neisseria meningitidis is able to survive inside macrophages and be transported throughout the body in them. |
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| TRUE |
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| Untreated gonorrhea in women can lead to a condition known as ______. |
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| PID |
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| Neisseria is distinguished from many other Gram-negative pathogens by being ____ positive. |
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| oxidase |
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| Because of the existence of ______ carriers, the eradication of meningococcal disease is unlikely. |
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| healthy asymptomatic carriers |
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| Infection with _____ can frequently be diagnosed by the presence of blue-green discoloration of tissues. |
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| Pseudomonas aeruginosa |
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| The ____ in enteric bacteria allows them to form channels through which bacterial proteins are introduced into the host cell, helping them evade immune surveillance. |
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| type III secretion system |
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| Antimicrobial therapy in individuals infected with Enterobacteriaceae may worsen the prognosis b/c of the release of large amounts of ______. |
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| Lipid A |
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| The pleomorphic bacterium ____ is an intracellular parasite that can lead to respiratory disease when inhaled in aerosols from moist environments. |
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| Legionella |
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| Pneumonia caused by ____ often involves the destruction of alveoli and the production of bloody sputum. |
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| Klebsiella pneumoniae |
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| Of all the types of Proteus, ______ is the most common species associated with disease in humans. |
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| P. mirabilis |
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| Scientists have identified over 2000 unique serotypes of Salmonella, but DNA analysis indicates that they belong to a single species: _______. |
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| S. enterica |
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| ________, caused by Yersinia pestis, is not spread from person to person. |
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| Bubonic plague |
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| ____ are gammaproteobacteria that are oxidase positive and require cytochromes or heme as part of their growth requirements. |
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| Pasteurellaceae |
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| The zoonosis _____ can be acquired by humans in a variety of ways, including inset bites and ingestion of infected animals. |
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| tularemia |
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| Dermonecrotic toxin is produced by _____ and causes localized constriction and hemorrhage of blood vessels, resulting in cell death and tissue destruction. |
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| Bordetella pertussis |
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| _____ is a medical puzzle b/c even though it expresses a wide range of virulence factors, it rarely causes disease. |
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| Pseudomonas aeruginosa |
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| Why is treatment with antimicrobial drugs NOT encouraged in patients with diarrhea caused by enteric bacteria? |
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| Antimicrobial treament of enteric diarrhea can worsen the prognosis by killing many bacteria at once, releasing large amounts of lipid A. The release of lipid A from these bacteria causes fever, vasodilation, inflammation, shock, and DIC, potentially leading to death. In addition, the diarrhea is normally self-limiting, and the expulsion of the organisms from the body is often more effective than antimicrobial phagocytes. |
