Microbiology Final Review Quiz, Microbiology Module 6, Microbiology Module 5, Microbiology Module 3, Microbiology Module 2, Microbiology Module 1

When microbiologists set up a biochemical identification using a commercial system on a suspected pathogen from a culture, they must: a. Observe the culture after 18 to 24 hours of incubation. b. Use quality control organisms to ensure the identification of the organism is correct. c. Correlate colony characteristics with the suspected identification of the organism. d. Recognize the colony characteristics of the pathogen.

*** not observe the culture after 18 to 24 hours of incubation

An elderly patient in a nursing home is recovering from bacterial pneumonia. The patient has been on a lengthy regiment of antibiotics to kill the organism causing the disease. A few days later, the patient is diagnosed with pseudomembranous colitis. What organism is the most likely cause?

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What disease does Clostridium botulinum cause?

...

What disease does Clostridium perfringens cause?

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What disease does Clostridium tetani cause?

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What organism mostly commonly causes gas gangrene?

...

In any susceptibility system, variables that can affect the results include the following: 1. Antibiotic potency 2. Inoculum concentration 3. Bactericidal level 4. pH 5. Anion content

1, 2, and 4 are correct

This reagent is used to demonstrate a positive phenylalanine deaminase test. a. a-Naphthol b. 40% sodium hydroxide c. 10% ferric chloride d. Methyl red

10% ferric chloride

A test is performed on a group of 10 patients. Six patients have a disease, and four are free of the disease. If six patients (all known to have the disease) of this group test positive for the disease, we say that the clinical sensitivity of this test is:

100%

Under what conditions should inoculated plates for Neisseria gonorrhoeae culture be incubated?

35° C and 3% to 5% carbon dioxide

The two reagents used in the Voges-Proskauer Test are: a. 40% KOH and a-naphthol b. o-Nitrophenol and a-naphthol c. 40% KOH and methyl red d. Methyl red and acetoin

40% KOH and a-naphthol

What temperature is an optimal growth temperature for Campylobacter jejuni?

42° C

Diphtheria is a disease produced by Corynebacterium diphtheriae. However, not all C. diphtheriae bacteria produce the toxin that causes this disease. To produce the toxin, the bacteria must first become infected with a bacteriophage. The process by which bacterial genes are transferred to new bacteria by the bacteriophage is called:

Transduction

What amino acid is the substrate in indole test broth? a. Arginine b. Leucine c. Tryptophan d. Ornithine

Tryptophan

Using two disinfectants to clean an area may actually do more harm than good. Why?

Two disinfectants may inactivate one another's activity against microorganisms.

What disease produced by a salmonellae species is a severe form of enteric fever?

Typhoid fever

What enables the microbiologist to select the correct media for primary culture and optimize the chance of isolating a pathogenic organism?

Understanding the growth requirements of a particular bacterium

What is a major cause of pelvic inflammatory disease in women?

Untreated gonococcal cervicitis

All of the following are characteristics of Shigella spp. EXCEPT:

Urea positive

Gonococcal infections occur primarily in all the following sites EXCEPT:

Uterus

What is the name of the organism that causes the disease cholera?

V. cholerae

If a female is symptomatic, what are the symptoms of Neisseria gonorrhoeae infection in women?

Vaginal discharge and dysuria

Aeromonads are generally susceptible to all these antibiotics EXCEPT:

Vancomycin

All of the following statements are true about viruses EXCEPT: a. Viruses do not need host cells to survive. b. Viruses are acellular but are surrounded by a protein coat. c. Viruses can infect bacteria, plants, and animals. d. Viruses consist of DNA or RNA but not both.

Viruses do not need host cells to survive.

This system provides rapid identification of gram-negative bacteria through the use of cards. a. MicroScan b. Sherlock Microbial Identification system c. Vitek AutoMicrobic system d. BD Phoenix 100

Vitek AutoMicrobic system

An example of an emerging disease is:

West Nile virus

Notations from the macroscopic (gross) examination of a specimen should include all the following EXCEPT: a. Stool consistency b. Blood or mucus present c. What type of container the specimen was collected in d. Swab or aspirate

What type of container the specimen was collected in

The decarboxylase tests determine: a. Whether the bacteria can further metabolize the acids formed during fermentation to 2,3 butanediol b. Whether the bacteria possess enzymes capable of removing the carboxyl group of specific amino acids in the test medium c. To see if a-naphthol can be broken down into its constituent parts: acetoin and diacetyl KOH d. If bacteria can maintain an acid pH if only sucrose is present in the media

Whether the bacteria possess enzymes capable of removing the carboxyl group of specific amino acids in the test medium

When plating a nonroutine culture on primary culture media, the tech should ask all the following questions EXCEPT: a. Are the organisms to be found in this specimen likely to be fastidious or nonfastidious? b. Is the specimen likely to contain low numbers or high numbers of organisms? c. What anaerobic bacteria will be present in this specimen? d. Are any normal florae presently associated with the specimen?

Are the organisms to be found in this specimen likely to be fastidious or nonfastidious?

Skin or pyodermal infections with group A streptococci result in all the following syndromes EXCEPT:

Bullous impetigo

Which plant pathogen may be mistaken for Burkholderia cepacia?

Burkholderia gladioli

The direct microscopic examination is a useful tool for all the following reasons EXCEPT: a. It can give the microbiology technologist and the physician an indication of the infectious process involved. b. It can dictate the need for nonroutine or additional testing. c. It can tell the physician what type of normal flora is present on the smear and if it is anaerobic or aerobic. d. It can be used to determine the quality of the specimen.

It can tell the physician what type of normal flora is present on the smear and if it is anaerobic or aerobic.

What is the name of the test used to presumptively identify group B streptococci?

CAMP

What organism may play a role in Guillain-Barré syndrome (GBS)?

Campylobacter

Escherichia coli strains are associated with all the following properties EXCEPT:

Can use citrate as a sole carbon source

What organisms often are involved in septicemia in the granulocytopenic patient?

Capnocytophaga

All of the following are normal inhabitants of the human oral cavity EXCEPT:

Capnocytophaga fusofurium

To which category does Neisseria spp. belong?

Capnophilic

This bacterial state occurs when a host harbors a disease-causing organism, but does not show signs of disease.

Carrier

What test differentiates staphylococci from streptococci?

Catalase

What is the drug of choice for treating a life-threatening illness caused by H. influenzae?

Ceftriaxone

What are the confirmatory tests performed at a state laboratory for Bacillus anthracis?

Cell-wall polysaccharide and a capsule antigen

The three proteins that make up the anthrax toxin include all the following EXCEPT:

Cellular factor

If a Gram stain of urethral discharge from a male has more than four polymorphonuclear leukocytes per field but no bacteria, what organism is suspected of causing the infection?

Chlamydia trachomatis

What organism is an opportunistic pathogen that strikes the immunocompromised patient with neutrophil deficits and produces a violet pigment on nonselective agar?

Chromobacterium violaceum

What antibiotic, in 2000, was approved by the Food and Drug Administration (FDA) for post exposure inhalation anthrax?

Ciprofloxacin

The HACEK group includes all of the following EXCEPT:

Clostridium difficile

What is the most common causative agent of gas gangrene? a. Staphylococcus aureus b. Haemophilus influenzae c. Clostridium perfringens d. Neisseria gonorrhea

Clostridium perfringens

All the following are general characteristics of the genus Bacillus EXCEPT:

Cocci

Where are most Salmonella serotypes found?

Cold-blood animals (fish)

In an outbreak investigation and in the collection of routine surveillance data, what sorts of activities are critical?

Collecting, processing, reporting, and reviewing pertinent cultures

Colony morphology is defined as: a. Colony constitution and environmental conditions b. Colony smell and shape c. Colony size and color d. Colony characteristics and form

Colony characteristics and form

Oxidative/fermentative (O/F) basal medium is a medium that will test the oxidative and fermentative capabilities of a microbe. The pH indicator is _____. a. Sudan IV b. Bromcresol green c. Phenolphthalein d. Bromthymol blue

Bromthymol blue

Campy-BAP contains:

Brucella agar base, 10% sheep red blood cells, vancomycin, trimethoprim, polymyxin B, amphotericin B, and cephalothin

How is cholera treated?

Copious amounts of intravenous fluids

What organism displays Babès-Ernst granules on a Gram stain?

Corynebacterium diphtheriae

Because infections can be encountered via the air, _____ can cause transmission of some pathogens.

Coughing

Staphylococcus aureus food poisoning is most commonly caused by these two enterotoxins.

A and D

Parasitism is:

A biologic relationship in which one species gains benefits at the expense of the host

Plesiomonas spp. cause all of the following clinical types of gastroenteritis EXCEPT:

A hemorrhagic diarrhea

The three regions of the lipopolysaccharide include all the following EXCEPT:

Mycolic acid

Name the two reagents that are needed to visualize nitrite in the nitrate reduction test. a. Sulfuric acid and a-naphthol b. N,N-dimethyl-a-naphthylamine and sulfanilic acid c. Sulfanilic acid and 40% sodium hydroxide d. N,N-dimethyl-a-naphthylamine and sulfuric acid

N,N-dimethyl-a-naphthylamine and sulfanilic acid

Nonpathogenic commensal Neisseria spp. include all the following EXCEPT:

N. meningitidis

What Neisseria spp. can be found as part of the transient flora of the upper respiratory tract?

N. meningitidis

Diagnostic schemes in the microbiology laboratory typically analyze each unknown bacterium's metabolic processes for all the following EXCEPT: a. Production of specific end products from specific substrates b. Production of an acid or alkaline pH in the test medium c. Energy utilization for metabolic processes d. Utilization of a variety of substrates as carbon sources

Energy utilization for metabolic processes

Quality control is designed to:

Ensure the medical reliability of lab data

What substance, when produced by Salmonella spp. that cause gastroenteritis, has been implicated as a significant virulence factor?

Enterotoxin

Staphylococcal enterotoxin B is linked to:

Enterotoxin B has been linked to staphylococcal pseudomembranous enterocolitis, although the mechanism is not understood.

The primary reservoir for staphylococci is:

Nares

What is the specimen of choice for Bordetella species?

Nasopharyngeal swabs

What is the drug of choice for treating Bordetella infections?

Erythromycin

What is the drug of choice to treat group A streptococci when the patient cannot tolerate penicillin?

Erythromycin

What disease is produced by group A streptococci that is characterized by a rapidly progressing inflammation and necrosis of the skin, subcutaneous fat, and fascia?

Necrotizing fasciitis

The most common route of infection of laboratory workers with hepatitis B virus (HBV) and human immunodeficiency virus (HIV) is:

Needlestick

Which organism is the most common cause of urinary tract infections (UTIs) in humans?

Escherichia coli

Many materials in hospitals that must be sterilized cannot withstand steam sterilization. Gas sterilization is used instead, using this gas.

Ethylene oxide

The virulence factors for Neisseria spp. include all the following EXCEPT:

Exotoxin

How can Nocardia spp. be presumptively identified?

Filamentous, branching organisms with a carbolfuchsin acid-fast stain with a weak acid decolorizer, but not a Kinyoun acid-fast stain

Three levels of laboratories outlined in the Laboratory Response Network (LRN) include all the following EXCEPT: a. First responder b. National responder c. Sentinel d. Reference

First responder

What are the primary antigens used in serologic grouping of salmonellae?

Flagellar H antigen and somatic O antigen

What disease can newborns acquire through a birth canal infected with Neisseria gonorrhoeae?

Ophthalmia neonatorum

Despite all its virulence factors, what type of pathogen is Pseudomonas aeruginosa?

Opportunistic

This process results in enhanced phagocytosis by neutrophils.

Opsonization

Media that do not need to be retested by the hospital laboratory must still undergo observation for all of the following EXCEPT: a. Organism colony characteristics b. Breakage c. Sterility d. Moisture

Organism colony characteristics

Common schemes to classify streptococci include all the following EXCEPT:

Flagellar antigens

Specimens such as blood, bone marrow, and synovium are mixed with anticoagulants right after collection. Why should this occur?

Organisms become bound up in the clotted material and are difficult to isolate.

A clinical laboratory scientist is working on the bench, reading plates, and notices that a culture has both a unicellular form and a filamentous form. What type of organism exhibits these forms?

Fungi

Elizabethkingae (Chryseobacterium) meningosepticum causes all the following diseases EXCEPT:

Gastroenteritis

Lysogeny occurs when:

Genes present in the bacteriophage DNA are incorporated into the bacteria's genome.

All the following tests should be performed by sentinel laboratories to rule out the possibility of Bacillus anthracis from an isolate EXCEPT:

Glucose fermentation

The tech needs to sterilize a piece of equipment that cannot be autoclaved or gas sterilized because the equipment contains lenses, metal, and rubber components. What solution should be used to sterilize this piece of equipment?

Glutaraldehyde

What is the name of the genus whose members are called nocardioforms?

Gordonia

When differentiating colony size on the culture plates, what organisms generally have the larger colonies by comparison? a. Gram-positive rods b. Gram-positive cocci c. Gram-negative rods d. Gram-negative diplococci

Gram-negative rods

What Haemophilus species is called the Koch-Weeks bacillus?

H. aegyptius

What organism causes Brazilian purpuric fever (BPF)?

H. influenzae biogroup aegyptius

You are working in a microbiology laboratory and receive a sputum for culture. You perform a Gram stain on the sputum and get the following results: 3+ gram-positive cocci, greater than 25 epithelial cells/10 field, less than 10 neutrophils/10 field, and heavy mucus. What do these results indicate? a. An unacceptable specimen that should be worked up with definitive identification for all bacteria present b. An acceptable specimen and workup that should be limited to the basic identification of bacteria c. An unacceptable specimen and workup that should be limited to basic identification of bacteria d. An acceptable specimen that should be worked up with definitive identification for all bacteria present

An unacceptable specimen and workup that should be limited to basic identification of bacteria

What organisms, which are gram-negative coccobacilli, can appear as gram-positive cocci in smears made from blood culture bottles?

Acinetobacter spp.

Nosocomial infections are:

Acquired at hospitals

What is the purpose of a capsule?

Act as a virulence factor in helping the pathogen evade phagocytosis

If an organism fermented glucose only and utilized peptones, what would the triple sugar iron (TSI) reaction be? a. Alkaline/alkaline b. Acid/alkaline c. Acid/acid d. Alkaline/acid

Alkaline/acid

Characteristics of Moraxella include:

All of the above

Which species are associated with infections in humans?

All of the above

Where are the viridans streptococci constituents of the normal florae?

All of the above The viridans streptococci are constituents of the normal florae of the upper respiratory tract, the female genital tract, and the gastrointestinal tract. The term viridans means green.

Bacterial growth requirements for oxygen and carbon dioxide can be divided into all the following categories EXCEPT: Answer a. Anaerobic (0% O2) b. Capnophilic (about 15% O2 and 5% to 10% CO2) c. Ambient air (95% O2 and 5% CO2) d. Microaerophilic (5% O2 )

Ambient air (95% O2 and 5% CO2)

Members of the Alcaligenes are usually susceptible to all the following antibiotics EXCEPT:

Aminoglycosides

A bacterial DNAase is: a. An oligonucleotide formed from a native RNA b. An endonuclease that cleaves internal phosphodiester bonds, resulting in smaller subunits of DNA c. A proteolytic enzyme that forms extracellular DNA in the bacterial cell d. An oligonucleotide formed from a native DNA

An endonuclease that cleaves internal phosphodiester bonds, resulting in smaller subunits of DNA

Diabetics may sometimes be infected with their own resident florae. This type of infection is called:

An opportunistic infection

What is an anaerobe?

An organism that does not require oxygen to live

What is an obligate anaerobe?

An organism that grows only in the absence of molecular oxygen

This type of bacteria is able to live in the colon with little to no oxygen and is the predominant organism.

Anaerobes

When performing tests in the microbiology laboratory, the detection limit of a test refers to the _____ of that test.

Analytic sensitivity

A subsequent exposure to the same antigen elicits a(n) _____, characterized by a rapid increase in IgG antibody associated with higher levels, a prolonged elevation, and a more gradual decline in antibody levels.

Anamnestic immune response

All of the following are poor prognostic factors associated with Pseudomonas aeruginosa bacteremia EXCEPT:

Anemia

Who was considered the father of protozoology and bacteriology?

Anton van Leeuwenhoek

All of the following include disadvantages of nucleic acid probes for Neisseria gonorrhoeae EXCEPT:

Are able to identify all N. gonorrhoeae isolates, including beta-lactamase-positive strains

This test determines if an organism is a delayed lactose-fermenter. a. Nitrate b. Dihydroxylase c. b-Galactosidase d. Ortho-Nitrophenyl-b-D-galactopyranoside (ONPG) test

Ortho-Nitrophenyl-b-D-galactopyranoside (ONPG) test

What antibiotic is used for detection of methicillin resistance?

Oxacillin

What biochemical test will differentiate nonfermenters from Enterobacteriaceae (except Plesiomonas)?

Oxidase

All of the following are biochemical characteristics of Vibrio spp. EXCEPT:

Oxidase negative

All of the following characteristics describe the genus Plesiomonas EXCEPT:

Oxidase negative

Bacteria can utilize carbohydrates by: a. Induction b. Oxidation c. Reduction d. Synthesis

Oxidation

A tech is working the night shift and receives a CSF specimen on an infant. The tech makes a Gram stain of the spinal fluid then reads the smear under the microscope. The report the tech sends to the physician reads as follows: "gram-negative bacillus, small and pleomorphic." What bacteria are being implied as the infecting agent? a. Legionella pneumophila b. Staphylococcus aureus c. Escherichia coli d. Haemophilus influenzae

Haemophilus influenzae

A microbiologist is reading a sputum culture when she notices tiny, translucent colonies growing closely around a b-hemolytic colony on sheep blood agar (SBA). In fact, the colonies are growing in the area where the blood has been hemolyzed. What is the probable identity of the organism that is growing closely to the b-hemolytic organism, and why are they growing in the hemolyzed area?

Haemophilus spp., because they need the factor V in this area

A microbiologist is reading the plates from a sputum culture. On the sheep blood agar (SBA), she sees flat spreading colonies with a metallic sheen. On cetrimide agar, she sees a fluorescent green color in the media with clear colonies. On MacConkey, she sees medium clear colonies that have a fruity or grape-like odor. What is the most likely organism?

P. aeruginosa

Chemosterilizers exert their killing effect through all the following mechanisms EXCEPT: a. Denaturation of cellular proteins b. Inactivating enzyme substrates c. Reactions with components of the cytoplasmic membrane d. Damage of RNA and DNA

Inactivating enzyme substrates

A test can have both a positive and negative predictive value. All the following elements are needed to compute the positive and negative predictive value of a test EXCEPT: a. Incidence of the disease being tested b. Specificity of a test c. Sensitivity of a test d. Prevalence of the disease being tested

Incidence of the disease being tested

Healthy people are colonized by many different bacteria in many different sites. These bacteria are referred to as:

Indigenous florae

All of the following are characteristics of nonfermenters EXCEPT:

Indole positive

What form of anthrax is found among animal workers and has been dubbed woolsorter's disease?

Inhalation

Streptococcus agalactiae is a significant cause of?

Invasive disease of the newborn

What technique is used to isolate bacterial colonies when streaked onto an agar plate?

Isolation streaking

What are the effects of the b-hemolysin produced by Staphylococcus aureus?

It acts on sphingomyelin in the plasma membrane of red blood cells.

What organism causes pulmonary disease among individuals with cystic fibrosis?

P. aeruginosa

What is the most frequently isolated Pasteurella species?

P. multocida

This is a leukocidin that is lethal to leukocytes and produced by staphylococci.

Panton-Valentine

The ability of an organism to produce disease in a susceptible individual is called:

Pathogenicity

All of the following organisms are found on the skin EXCEPT:

Peptostreptococcus

Commonly encountered polymicrobial infections are: a. Infant meningitis b. Food poisoning c. Indwelling catheter infections d. Perirectal abscesses

Perirectal abscesses

After perforation of the colon, surgeons must guard against infection in the _____ because of leakage of the contents of the colon.

Peritoneal cavity

Why is laboratory-acquired infection an obvious hazard for personnel working in a microbiology lab?

Personnel deal with a variety of infections agents: viral, fungal, parasitic, and bacterial.

This test is useful in the initial differentiation of Proteus, Morganella, and Providencia species from the rest of the Enterobacteriaceae. a. Amino acid decarboxylase b. Oxidation-fermentation c. Methyl red d. Phenylalanine deaminase

Phenylalanine deaminase

Which of the following descriptions will directly facilitate identification of bacteria? a. Environmental growth temperature b. Colony color c. Environmental growth atmosphere d. Physical characteristics of colony morphology

Physical characteristics of colony morphology

What do aeromonad colonies look like on cefsulodin-irgasan-novobiocin (CIN) agar?

Pink colonies

A night tech is working in microbiology when a cerebrospinal fluid (CSF) specimen comes in. Almost simultaneously, the tech is called to the emergency department to draw blood on seriously injured car accident victims. How would the tech store the CSF until time permits to work on the CSF specimen?

Place the specimen in a 35° C incubator for 6 hours.

What structure is a phospholipid bilayer embedded with proteins and cholesterol that regulates the amount of chemicals that pass in and out of a cell?

Plasma membrane

Genes that code for antibiotic resistance are often found on extracellular, small, circular pieces of DNA. These DNA pieces are called:

Plasmids

The technician in the laboratory has received a specimen that is rejected. The technician calls the physician and tells the physician the specimen is unacceptable and the reason why. The physician insists that the culture needs to be performed on this unacceptable culture. What should the technician do?

Plate the culture, but include a comment explaining the potentially compromised test results.

Aeromonads have been implicated in all of the following diseases EXCEPT:

Pneumonia

The elevation of bacterial colonies is described by all the following EXCEPT: a. Umbilicate b. Raised c. Pointed d. Convex

Pointed

Category A bioterrorism agents:

Pose the highest threat because they are easily transmitted and highly infectious

After attachment to host cells, a pathogen uses all the following mechanisms to establish itself and cause disease EXCEPT: a. Circumvents host antibodies by shifting key cell-surface antigens b. Produces lysozyme to kill the host cell c. Uses lactoferrin for iron d. Produces an IgA protease that degrades the IgA at mucosal surfaces

Produces lysozyme to kill the host cell

The symptoms of inhalation anthrax include all of the following EXCEPT:

Productive cough

The most concentrated forms of ethanol and isopropyl alcohol are less bactericidal than the diluted forms of these alcohols. Why?

Proteins are not denatured readily in the absence of water.

The lysine iron agar (LIA) slant is also useful in differentiating: a. Proteus, Morganella, and Providencia b. Klebsiella and Enterobacteriaceae c. Escherichia, Salmonella, and Campylobacter d. Acinetobacter and Alcaligenes

Proteus, Morganella, and Providencia

The function of a cell wall is to:

Provide rigidity and strength to the exterior of the cell.

Using Möeller's decarboxylase base medium, what color is a positive reaction and what causes this color to be produced? a. Yellow, alkaline environment produced b. Purple, acid environment produced c. Purple, alkaline environment produced d. Yellow, acid environment produced

Purple, alkaline environment produced

What is the specimen of choice in males for genital infections?

Purulent discharge

These disinfectants are cationic, surface-activated agents that work by reducing the surface tension of molecules in a liquid, resulting in the disruption of the cellular membrane of microbes.

Quaternary ammonium compounds

The classic example of a bite-wound infection is:

Rabies

How is Neisseria meningitidis spread?

Respiratory droplets

These are enzymes that cut the bacterial DNA at specific locations.

Restriction enzymes

The following are provisions of CLIA 88 EXCEPT: a. Verify employee competency upon employment. b. Reverify the employee's competency monthly. c. Reverify the employee's competency annually. d. Determine an employee's competency.

Reverify the employee's competency monthly.

What organism shows diphtheroid gram-positive rods with traces of branching on a Gram stain?

Rhodococcus equi

Prokaryotic cells have which the following structures in their cytoplasm?

Ribosome

The symptoms of gastrointestinal anthrax include all the following EXCEPT:

Rice water stools

What organism is a member of the human oropharyngeal flora, but has been isolated from people with endocarditis? .

Rothia dentocariosa

A laboratory professional is testing a new antimicrobial soap. The tech washes her forearm, then does a culture of the skin. Which organisms should she expect to find growing in the culture?

S. epidermidis and Propionibacterium

The two most common species of coagulase-negative staphylococci are:

S. epidermidis and S. saprophyticus

A woman in her 20s goes to her physician complaining of burning upon urination, frequency, and general malaise. Her physician does a urine culture, and it grows out 25,000 colony-forming units (CFU)/mL of a catalase-positive, coagulase-negative, novobiocin-resistant gram-positive cocci. What is the most likely pathogen?

S. saprophyticus

What organism possesses the Vi antigen?

Salmonella serotype Typhi

What is benchmarking?

Seeking an industry's or profession's best practices to imitate and improve

In the laboratory, the clinical microbiologist is responsible for all the following EXCEPT: a. Isolating microorganisms b. Selecting treatment for patients c. Identifying microorganisms d. Analyzing bacteria that cause disease

Selecting treatment for patients

What type of medium is used in the motility test? a. Peptone gel b. Sabouraud dextrose c. Semisolid d. Cornmeal

Semisolid

What genus of bacteria is considered an opportunistic pathogen associated with nosocomial outbreaks?

Serratia

When choosing a test to perform in your laboratory, an in-house verification is always performed. Verification of a test:

Serves to establish that the performance parameters of the test are satisfactory

Because cell wall-damaged bacteria, antibiotic-treated bacteria, or dead bacteria may appear falsely gram-negative, what are "critical cocharacteristics"? a. Growth characteristics b. Color and cell wall composition c. Shape and size d. Size and color

Shape and size

A positive test for motility: a. Will turn blue after the addition of the indicator bromthymol blue b. Turns the motility media blue c. Appears as a scum on the top of the media d. Shows hazy appearance throughout or movement away from a stab

Shows hazy appearance throughout or movement away from a stab

Anaerobes outnumber aerobes in all of the following locations EXCEPT:

Skin

Three types of specimens can be batch processed, including all the following EXCEPT: a. Specimens for acid-fast bacillus (AFB) cultures b. Specimens for Neisseria gonorrhea (GC) cultures c. Stool specimens for ova and parasite tests that are collected in preservatives d. Specimens for viral culture collected in viral transport media

Specimens for Neisseria gonorrhea (GC) cultures

What is unique about the Sphingobacterium spp.?

Sphingophospholipids in the cell wall

What type of bacteria are those in the genus Clostridium?

Spore-forming anaerobic bacilli

This infection occurs secondary to influenza A virus, has a high mortality rate, and occurs among the infants and immunocompromised patients.

Staphylococcal pneumoniae

What is the most common causative agent of pyoderma? a. Staphylococcus aureus b. Haemophilus influenzae c. Clostridium perfringens d. Neisseria gonorrhea

Staphylococcus aureus

What causes the red spreading rash in scarlet fever?

Streptococcal pyrogenic exotoxins

A technician is reading a vaginal culture on the bench. There is growth on the sheep blood agar (SBA) and chocolate (CHOC) plates, but no growth on the MacConkey (MAC) plate. The colonies growing on the SBA have produced a narrow, diffuse zone of b-hemolysis around and under the colonies. What organism could this be? a. Streptococcus pneumoniae b. Escherichia coli c. Streptococcus agalactiae d. Streptococcus pyogenes

Streptococcus agalactiae

What organism on sheep blood agar (SBA) has colonies that are small and transparent, surrounded by a wide zone of b-hemolysis?

Streptococcus pyogenes

When looking at a tube of thioglycollate broth, streamers or vines and puffballs are visible. What organism grows like this in thioglycollate? a. Pseudomonas spp. b. Gram-negative rods (Enterobacteriaceae) c. Streptococcus spp. d. Yeast

Streptococcus spp.

Some pathogens will not grow in culture and are usually unsuspected. This pathogen can be seen in the sputum and bronchoalveolar fluid of patients with a hyperinfestation syndrome. The name of this pathogen is: a. Giardia lamblia b. Strongyloides stercoralis c. Klebsiella pneumoniae d. Staphylococcus aureus

Strongyloides stercoralis

What are the sugars present in triple sugar iron (TSI)? a. Sucrose, glucose, rhamnose b. Mannitol, lactose, arabinose c. Sucrose, glucose, lactose d. Lactose, sucrose, raffinose

Sucrose, glucose, lactose

What substances do organisms that use oxygen have to protect themselves from superoxide anions?

Superoxide dismutase and catalase

Colony characteristics for Staphylococcus aureus on blood agar after 18 to 24 hours incubation at 35° C include all the following EXCEPT:

Swarming

All of the following steps should be used to prepare a smear from thick, granular, or mucoid materials EXCEPT: a. If the material is still too thick, repeat the first three steps with another (third) glass slide. b. Take an additional swab and rub it back and forth on the two glass slides to ensure the material is thin enough to read once it is stained. c. Once the material is flattened and sufficiently thinned, pull the glass slides smoothly away from each other to produce two smears. d. Place a portion of the sample on the labeled slide, and press a second slide onto the sample to flatten or crush the components.

Take an additional swab and rub it back and forth on the two glass slides to ensure the material is thin enough to read once it is stained.

All of the following characteristics are used to describe bacterial colony characteristics EXCEPT: a. Temperature b. Elevation c. Hemolysis d. Color

Temperature

What test presumptively differentiates b-hemolytic group A streptococci and nonhemolytic group D enterococci from other streptococcal species?

The PYR hydrolysis test provides a high probability for the presumptive differentiation of the b-hemolytic group A streptococci and the nonhemolytic group D enterococci from the other streptococcal species.

When bacteria are growing, they go through a log phase when:

The bacteria numbers usually double with each generation time

The Biosafety Levels were categorized using all the following criteria EXCEPT: a. The bacterial load necessary to cause infection b. Whether there is treatment available for an infection c. The organism's mode of transmission d. The organism's ability to cause serious illness

The bacterial load necessary to cause infection

The relative concentration of bacteria on culture plates is directly proportional to: a. The environment in which the bacteria is grown b. The concentration in which they are present in the clinical specimen c. The amount of bacteria isolated from the initial inoculation on the plate d. The amount of nutrients in the culture plates

The concentration in which they are present in the clinical specimen

If a test is not considered appropriate for the specimen, the following should happen:

The laboratory needs to communicate with the physician to determine exactly what needs to be done.

Why can't direct microscopy be used to provide a presumptive identification of the enteric bacteria?

The microscopic characteristics are indistinguishable from other gram-negative bacteria

The principle of the citrate test includes all the following EXCEPT: a. Bacteria able to use citrate will use the ammonium salts releasing ammonia. b. The alkaline pH that results from use of the ammonium salts changes the pH indicator. c. The pH indicator changes from red to bright yellow. d. The pH indicator changes from green to blue.

The pH indicator changes from red to bright yellow.

Information that the microbiology laboratory can provide to infection control practitioners includes:

The prevalence of a particular pathogen

Data generated by the laboratory is directly influenced by:

The quality of the specimen and its condition when received

How is culture media selected for specimen plating?

The selection of media to inoculate is based on the type of specimen submitted for culture and the organisms likely to be

What is the mechanism by which toxic shock syndrome toxin-1 (TSST-1) causes toxic shock syndrome (TSS)?

The toxin is a superantigen that stimulates T-cell proliferation with production of large amounts of cytokines.

When using disinfectants, it is important to follow the manufacturer's instructions for diluting the product because if it is not diluted properly:

There may not be enough free chemicals to kill the organisms.

For the most effective microbial killing, all iodophors must be properly diluted because:

There must be enough free iodine to kill the microorganisms.

Infections with Vibrio spp. can be contracted in all of the following situations EXCEPT:

They are found in water environments and can contaminate fish and shellfish Not the answer: Increased use of recreational water facilities

What advantage do the methods based on enzyme substrates have over conventional methods? a. They use fluorogenic substrates. b. They reduce the amount of substrate needed for the reactions. c. They do not require growth of the organism in the system. d. They use filter paper as the structure to hold the bacteria.

They do not require growth of the organism in the system.

How do staphylococci spread so easily when infecting the skin?

They produce hyaluronidase, which hydrolyzes hyaluronic acid present in the intracellular ground substance that makes up connective tissue.

When performing the oxidative/fermentative (O/F) test, one tube is covered with mineral oil and one tube is left uncovered. Why is one tube covered with mineral oil? a. To create an anaerobic (fermentative) environment b. To create an aerobic (oxidative) environment c. To create a reductive environment d. To create an asaccharolytic environment

To create an anaerobic (fermentative) environment

A laboratory technician is working with tissue infected with Mycobacterium tuberculosis that has been preserved in formalin for a couple years. After dissecting the tissue, how should the worker sterilize the work area?

Wipe down the work area with a 10% bleach solution

How should specimen collection instructions be given to the patient to ensure collection of a good specimen for culture?

Written, using simple language (in several languages) and pictures to help the patient understand the procedure as it is verbally explained

A technician is reading a vaginal culture. She sees the very white colonies that are g-hemolytic on a blood agar plate but appear to have feet. What organism could this possibly be? a. Haemophilus influenzae b. Yeast c. Gram-positive cocci d. Gram-negative rods

Yeast

Physiologic classification of streptococci divide the species into all the following groups EXCEPT:

b-Hemolytic streptococci

The Vitek AutoMicrobic System is manufactured by: a. bioMériux b. Dade Behring c. Abbott d. Becton Dickinson

bioMériux

How does the Department of Transportation (DOT) define an infectious substance?

A material known to contain or suspected of containing a pathogen that causes disease in humans or animals

What is the colony morphology of A. haemolyticum on sheep blood agar (SBA)?

A narrow zone of b-hemolysis and a black opaque dot is seen when the colony is scraped away.

How is Helicobacter pylori presumptively identified?

A rapid urease test done on a gastric biopsy

The specimen of choice for detecting gastrointestinal pathogens is:

A stool specimen

What is pulsed-field gel electrophoresis?

A strain-typing technique that can be an important adjunct to epidemiologic investigations

Customers of a laboratory include all the following EXCEPT: a. Accrediting organizations b. Doctors c. Patients d. Insurers

Accrediting organizations

If bacteria utilize various carbohydrates for growth, it is usually detected by:

Acid production and change of color from the pH indicator

In what staining procedure does carbolfuchsin penetrate the bacterial cell wall through heat or detergent treatment?

Acid-fast stain

What is the name of the genus of organisms that colonized 45% of all tracheotomy patients?

Acinetobacter spp.

Automated antimicrobial susceptibility testing methods are not reliable in detecting these resistant staphylococci. What antibiotic are the bacteria resistant to?

Automated antimicrobial susceptibility testing methods are not reliable in detecting these isolates. Screening using a vancomycin agar plate as described by the Clinical and Laboratory Standards Institute (CLSI) performance guidelines should enhance detection of vancomycin-intermediate Staphylococcus aureus (VISA) and vancomycin-resistant Staphylococcus aureus (VRSA). Detection of these isolates should be confirmed by a reference method or laboratory, and reporting should follow Centers for Disease Control and Prevention (CDC) guidelines.

What is the name of the Bacillus species that causes anthrax in cattle?

B. anthracis

What other gram-positive rod is similar to Bacillus anthracis?

B. cereus

What organism causes melioidosis?

B. pseudomallei

What is the name of the species that, before the onset of bioterrorism and immunocompromised patients, was considered a common laboratory contaminant?

Bacillus

What Bacillus sp. is a relatively common cause of food poisoning and opportunistic infection in susceptible hosts?

Bacillus cereus

Local materials that may be added in the criteria for accepting or rejecting a respiratory specimen include all the following EXCEPT: a. Bacterial ropes b. Mucus c. Macrophages d. Ciliated columnar cells

Bacterial ropes

What two tests are used to presumptively identify Enterococcus?

Bile esculin and 6.5% NaCl broth

What two tests have been mainstays in identification schemes for the non-b-hemolytic, catalase-negative, gram-positive cocci?

Bile esculin and salt tolerance

Interferon is a substance produced by the body that inhibits viral replication. Interferon accomplishes this task by:

Binding to surface receptors that stimulate the cell to synthesize enzymes that inhibit viral replication over several days

The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) requires the following safety training to be documented in an employee's record EXCEPT: a. Proper storage of gases b. Blood-borne pathogen training c. Hazardous materials management d. Biosafety level training

Biosafety level training

A young adult goes to the emergency room complaining of headache, dizziness, stiff neck, and purpura with a petechial skin rash. What two tests should the physician immediately perform?

Blood and cerebrospinal fluid (CSF) culture

Processing of patient specimens and handling of actively growing cultures of microorganisms puts an employee at risk of potential contact with the infectious agent through all the following routes EXCEPT: a. Blood splashed onto intact skin b. Inhalation of aerosols c. Mucous membranes d. Accidental ingestion

Blood splashed onto intact skin

What organism causes the disease called whooping cough?

Bordetella pertussis

All of the following are members of the Citrobacter genus EXCEPT:

C. asteroides

What genus has the following characteristics: negative for urea, positive for lysine decarboxylase, positive for hydrogen sulfide, positive for indole, and does not grow on Simmon's citrate?

Edwardsiella

Why does the Möeller decarboxylase base medium contain glucose if it is testing the decarboxylation of amino acids? a. To get the energy needed to take the carboxyl group off the amino acid, the bacteria must have glucose b. When glucose is fermented, one of the by-products is acetoin. This acetoin is part of the mechanism that cleaves the carboxyl group from the specific amino acid. c. The decarboxylation of the amino acids takes place during the glucose metabolic pathway. Once glucose is broken down into pyruvic acid, then the amino acid is modified. d. Decarboxylases are inducible enzymes produced in an acid pH.

Decarboxylases are inducible enzymes produced in an acid pH.

Alcohols use this mechanism to inactivate microorganisms.

Denature proteins

In the United States, 15 to 20 outbreaks annually owing to waterborne pathogens cause this illness and affect several thousand people.

Diarrhea

MacConkey agar is used to: a. Differentiate between hemolytic and nonhemolytic gram-negative rods. b. Show the clear, pinpoint colonies of Haemophilus influenzae. c. Demonstrate the large, pink colonies of Neisseria meningitidis. d. Differentiate between lactose fermenters and lactose nonfermenters.

Differentiate between lactose fermenters and lactose nonfermenters.

When microbiologists encounter a sputum specimen, they know that the upper respiratory tract contains many indigenous organisms and to identify every organism in the culture would be a time-consuming, cost-prohibitive, and insurmountable task. So microbiologists must: a. Differentiate the potential pathogens from the "usual" inhabitants of the upper respiratory tract and direct the diagnostic workup only to potential pathogens. b. Work quickly with commercially available kits to identify all organisms present in a sputum specimen for the best quality patient care available. c. Be able to ascertain whether the results generated by a commercial or automated system correlate with the suspected organism. d. Work up only the gram-negative rods present in the culture.

Differentiate the potential pathogens from the "usual" inhabitants of the upper respiratory tract and direct the diagnostic workup only to potential pathogens.

Preventive maintenance on an instrument includes all the following EXCEPT: a. Disinfecting the surface of the instrument b. Oiling and cleaning the instrument c. Recalibrating instruments d. Replacing filters

Disinfecting the surface of the instrument

After using the phone, the laboratory tech sprayed the receiver with a chemical spray. This process will kill a defined scope of microorganisms. What is this process called?

Disinfection

A specimen that is spread on a smear and appears to have a homogenous constitution is said to: a. Contain normal florae b. Be clumped at different areas on the slide c. Have material spread evenly throughout the slide d. Contain pathogens only in one visual field

Have material spread evenly throughout the slide

Autoclaves use this method to sterilize inanimate objects.

Heat under steam pressure

Waterborne illnesses that may be associated with contaminated drinking water or recreation water include all the following EXCEPT: a. Hepatitis B b. Pseudomonas skin infection c. Legionellosis d. Hepatitis A

Hepatitis B

This class of antibodies is a pentamer.

IgM

Aerobes are bacteria that grow:

In ambient air

A cytocentrifuge is an excellent method for preparing nonviscous fluids because: a. It deposits cellular elements and microorganisms from the specimen onto the surface of a glass slide as a monolayer. b. The sediment is mixed with 70% albumin before spreading it on the surface of a slide. c. It concentrates the protein evenly throughout the slide surface. d. The cytocentrifuge not only spreads the specimen over the surface of a slide but also stains the specimen.

It deposits cellular elements and microorganisms from the specimen onto the surface of a glass slide as a monolayer.

All the following principles of specimen collection are fundamental to ensuring appropriate specimen management EXCEPT: a. It is acceptable to delay transport of the specimen to the laboratory if in transport media. b. Collect the appropriate quantity of specimen. c. Label the specimen accurately with the specific anatomic site and the patient information. d. Select the correct anatomic site to collect the specimen.

It is acceptable to delay transport of the specimen to the laboratory if in transport media.

The comprehensive safety program for the microbiology laboratory needs to fulfill all the following provision EXCEPT: a. It must teach correct techniques for lifting and moving heavy objects and patients (where applicable). b. It is specific to the hospital and does not need to conform to state, local, and federal regulations. c. It must address biologic hazards. d. It must describe the safe handling, storage, and disposal of chemicals.

It is specific to the hospital and does not need to conform to state, local, and federal regulations.

What are the effects of the a-hemolysin produced by Staphylococcus aureus?

It lyses red blood cells, damages platelets and macrophages, and can cause severe tissue damage.

What enteric organism may produce a blue-violet pigment on non-blood-containing media?

Kluyvera

After 24 hours, a sheep blood agar (SBA) from a vaginal culture is read. The SBA has a-hemolytic, pinpoint, rough colonies all over the plate. A catalase test is performed, and it is negative. What organisms do these characteristics fit?

Lactobacillus and viridans streptococci

In the medical microbiology laboratory, a gram-negative bacterium's ability to ferment this sugar is the first step in its identification.

Lactose

The initial screening of gram-negative rods is done by testing for the utilization of this carbohydrate. a. Sucrose b. Glucose c. Mannitol d. Lactose

Lactose

What organism produces a community-acquired pneumonia, with symptoms different than a Streptococcus pneumoniae pneumonia, leading to the designation of atypical pneumonia?

Legionella pneumophila

What work practice have microbiologists incorporated to keep laboratory testing cost effective while providing optimum patient care?

Limited identification procedures

Even though hypochlorites are inexpensive and have a broad range of microbes that they kill, they are not used as sterilants because of:

Long exposure time for sporicidal action

These are low-molecular-weight proteins secreted by T cells.

Lymphokines

Why does a fecal sample for culture need to be collected in a leak-proof, nonsterile container?

Many types of bacteria call the intestinal tract home; the specimen cannot become contaminated.

Colonies of Bacillus anthracis are described as: a. Medusa's heads b. Flower like c. Curschmann's spiral d. Mickey Mouse ears

Medusa's heads

Organisms that represent public health concerns can be recovered from patients in an acute care hospital. All of the following isolates are considered significant or major public health concerns that are reportable to public health jurisdictions to follow up as a potential outbreak EXCEPT: a. Neisseria meningitis b. Methicillin-resistant Staphylococcus aureus c. Encephalitis viruses d. West Nile virus

Methicillin-resistant Staphylococcus aureus

This system is widely used in microbiology laboratories today. a. API 20E b. MicroScan c. Enterotube d. Mueller-Hinton

MicroScan

Staphylococci are catalase-positive, gram-positive cocci that resemble other bacteria that are members of this family.

Micrococcaceae

All the following activities must occur for phagocytosis to take place and be effective in host defense EXCEPT: a. Attachment of the particle to the phagocyte b. Ingestion c. Migration of lymphocytes to the area of infection (chemotaxis) d. Killing

Migration of lymphocytes to the area of infection (chemotaxis)

The nuclear membrane in prokaryotes is:

Missing

The methyl red test detects metabolic by-products from what pathway? a. Citrate pathway b. Butylene glycol pathway c. Mixed acid fermentation pathway d. Clark and Lubs pathway

Mixed acid fermentation pathway

Streptococcus-like organisms that resemble enterococci and viridans streptococci include all the following EXCEPT:

Moraxella

What organism is a commensal of the upper respiratory tract and has become an opportunistic pathogen causing upper respiratory tract infections in otherwise healthy children and the elderly?

Moraxella catarrhalis

What is the most common member of the genus Moraxella isolated in the clinical laboratory?

Moraxella nonliquefaciens

This genus has one species associated with it that has been implicated in urinary tract infections. What is the name of this species?

Morganella morganii

Patients in both extended care facilities and home care settings are frequently immunosuppressed by disease or therapy and often need intravascular or other device-related care. The microbes identified in these patients are often opportunistic pathogens and include all the following EXCEPT: a. Candida b. Acinetobacter c. Neisseria meningitis d. Pseudomonas aeruginosa

Neisseria meningitis

What is the name of the iron-chelating compound produced by Nocardia spp.?

Nocobactin

These bacteria are unable to ferment either lactose or glucose, but they can degrade the peptones present in the triple sugar iron (TSI) agar or Kligler's iron agar (KIA) aerobically or anaerobically, resulting in the production of alkaline by-products in the slant or deep, respectively, changing the indicator to a deep red color. What kind of bacteria cannot ferment lactose or glucose? a. Nonenteric bacilli b. Anaerobic bacilli c. Gram-positive cocci d. Gram-positive rods

Nonenteric bacilli

In what single setting does Stenotrophomonas maltophilia produce all its disease?

Nosocomial

What species of Aeromonas is the most frequently associated with gastrointestinal infections?

Not the answer: A. caviae

What Vibrio species is most infrequently isolated in the laboratory?

Not the answer: V. parahaemolyticus, cholera

What two biochemical tests help distinguish Aeromonas species from other enterics?

Not the answer: Voges-Proskauer (VP) and indole, Oxidase and Simmon's citrate

How is Staphylococcus saprophyticus presumptively identified?

Novobiocin susceptibility

An iatrogenic infection is one that is:

Occurs as a result of medical treatment

A physician notices that several patients are infected with Clostridium difficile, but only a few of the patients are symptomatic for disease. The reason for this discrepancy is:

Only those strains of the organism carrying the extrachromosomal DNA coding for the toxin gene will produce toxin and cause the individuals to be symptomatic.

When performing a Gram stain on a gram-negative organism, the crystal violet is absorbed into this outer cell wall layer then washed away with the acid alcohol. What is the main component of the outer layer of the cell wall?

lipopolysaccharide