Chapter 1 - Bacteriology Flashcards
1
Q
Fermentation end-products are often used to aid the identification of bacteria. Fermentation results in:
A
Conversion of glucose to pyruvate
2
Q
The exchange of cellular DNA between two living bacterial cells that involves an intercellular bridge is called
A
Conjugation
3
Q
End-products of aerobic respiration
A
Carbon dioxide and water
4
Q
This mechanism involves cell-to-cell contact, a series of complex chemical signals between cells, and usually the formation of a BRIDGE or SEX PILUS
A
Conjugation
5
Q
This mechanism involves the uptake of free DNA by a recipient cell
A
Transformation
6
Q
This mechanism involves the acquisition of DNA through the action of a BACTERIOPHAGE.
> mediated by VIRUSES, by which DNA from two bacteria may come together in one cell, RECOMBINATION
A
Transduction
7
Q
A mordant that is applied after the primary stain to chemically bond the alkaline dye to bacterial cell wall
A
Gram’s iodine
8
Q
Bacteria considered as important pathogens when reading gram-stained smears of SOFT TISSUE ABSCESS
A
Staphylococcus aureus
9
Q
3% to 5% CO2
A
Aerobes
10
Q
5% O2, 10% CO2, 85% N
A
Microaerophilic
11
Q
85% N2, 10% H2, 5% CO2
A
Anaerobic
12
Q
This medium is very selective for enteric pathogens and is differential for Salmonella and Shigella
A
Hektoen Enteric Agar
13
Q
HEA: Yellow-orange colonies
A
Lactose fermenters (E. Coli)
14
Q
HEA: colorless/green colonies with unchanged medium
A
Non-lactose fermenter (Shigella, Providencia)
If w/ Black colonies: h2s production (Salmonella)
15
Q
Coagulase bound to the surface of the cell
A
Clumping factor
16
Q
The slide coagulase test is a rapid screening tesr for the production of
A
Free coagulase
17
Q
The Staphylococcus sp. that is more likely to cause uncomplicated urinary tract infections in nonhospitalized hosts, especially sexually active young women
A
Staphylococcus saprophyticus
18
Q
Toxic Shocks syndrome toxin-1 is an important virulence factor in staphylococcal disease. This toxin is classified into which group of toxins
A
Enterotoxin
19
Q
Mannitol Salt Agar is selective and differential for which organism
A
Staphylococcus
20
Q
The toxins of this organism are preformed in contaminated food
> the organism doesnt need to grow in the host and therefore the action is very rapid
A
Staphylococcus aureus
21
Q
Susceptible to bile and optochin, a-hemolytic, and major cause of bacterial meningitis, often carrying an antiphagocytic capsule
A
Streptococcus pneumoniae
22
Q
Susceptible to penicillin and bacitracin, B-hemolytic, PYR positive, major cause of bacterial pharyngitis, and often carrying an antiphagocytic M protein
A
Streptococcus pyogenes
23
Q
Hippurate hydrolysis-positive, B-hemolytic, a major cause of neonatal meningitis and sepsis, producer of CAMP factor
A
Streptococcus agalactiae
24
Q
Appearance of a Green band of RBCs around a colony (conversion of hemoglobin to methemoglobin)
A
Alpha hemolysis
25
A pathogenic, gram-positive bacilli that grows well at Refrigerator temperature
Listeria monocytogenes
26
This organism grows on tellurite medium, grows as black colonies with brown halos in Tinsdale medium, and shows gram-positive bacilli in irregular clublike shapes
Corynebacterium diphteriae
27
Clinical disease that shows gray pseudomembrane covering the oropharynx
Diptheria
28
Gram-positive bacillus, catalase-negative, H2S producer, nonmotile, nonsporeformer that can be found in a skin lesion
Erysipelothrix spp.
29
CAMP test positive, H2S negative and esculin negative
Listeria spp.
30
CAMP test negative, H2S positive, Esculin positive
Erysipelothrix spp
31
This is used in decontaminating sputum samples for the successful isolation of Mycobacterium tuberculosis
N-acetyl-L-cysteine (NALC)- NaOH mixture
32
This Mycoplasma organism is AFB positive but potentially noncultivable
Mycoplasma leprae
33
Mycoplasma tuberculosis complex consists of these 4 organisms:
1) M. tuberculosis
2) M. Bovis (in cattle)
3) M. bovis BCG (vaccine strain for the BCG vaccine)
4) M. africanum (in Western Africa and clinically similar to M. tuberculosis)
34
Runyon group that is slow growing, and produce a yellow-orange pigment when exposed to light
Runyon 1- Photocromogens
35
Runyon group that is slow growing, and produces a yellow-orange pigment in LIGHT or in DARK
Runyon 2- Scotochromogens
36
Runyon group that is slow growing, and do not produce pigment. Although some may produce very pale yellow, buff or tan pigment but do not intensify upon light exposure
Runyon 3- Nonchromogenic
37
Runyon group consisting of rapid growers
Runyon 4
38
The Tween 80 test involves Lipase that is able to hydrolyze _____ _____ _____ into ____ _____ and ______ _____
Polysorbate 80 ➡️ Oleic Acid + polyoxyethylated sorbitol
39
Ph Indicator of Tween 80 test
Phenol red
40
They are resistant to heat, cold, drying, most chemicals and boiling
Spores
41
The gram negative bacillus that can be described as oxidase-negative, nitrate-positive, indole-negative, citrate -positive, methyl red-positive, urease-negative, and H2S-positive
Salmonella enteritidis
42
The swarming gram-negative bacillus that can be described as oxidase-negative, nitrate-positive,indole-negative, and H2S-positive (SIM: + - +)
Proteus mirabilis
43
Profuse water diarrhea "rice water stools", leading to dramatic fluid loss, severe dehydration, and hypotension that frequently leads to death, is the hallmark of what toxin?
Cholera toxin
44
The selective medium thiosulfate citrate bile salts sucrose (TCBS) agar is especially formulated for isolating which pathogen from stool cultures?
Vibrio spp.
45
The majority of human infections with Campylobacter spp. are caused by?
Contamination of food, milk or water with animal feces
46
In the test for urease production, the presence of the enzyme hydrolyzes urea to ___ and ____
ammonia + CO2
47
A cytotoxin that causes inflammation and ulcerative lesions, destroys epithelial cells, and results in bloody, mucous-laden stools
Shiga Toxin
48
One of the most common causes of food-borne, human bacterial gastroenteritis in the US.
Campylobacter jejuni
49
This organism grows well on XLD agar and is a nonfermenting organism that produces H2S, resulting in black pigment
Salmonella enteritidis
50
This organims appears as clear colonies on XLD agar
Shigella sonnei
51
Both of these organisms are lactose fermenting and appear as yellow colonies on XLD agar
Serratia and Klebsiella
52
Decarboxylation of the amino acids lysi\ne, ornithine, and arginine results in the formation of what end-products
amines
53
```
Identify the organism:
TSI reaction:
K/A
H2s - negative
Gas - not produced
```
Shigella spp.
54
The best specimen for the isolation of bordetella pertussis
Nasopharyngeal swabs
55
Gram-stain morphology of Brucella spp.
Gram - negative coccobacilli
56
this organism is seen on patients with pneumonia and this requires specialized medium for growth, 35*C, CO2, and extended incubation, hold for 2 weeks
Legionella pneumophila
57
Whic medium provides the NAD necessary for the growth of Haemophilus spp.
Chocolate agar (has X and V factors required for growth of Haemophilus spp.)
58
Growth around the only the X and V factor disks on the agar surface in FactorRequirement Test supports the identification of what species
Haemophilus
59
One of the HACEK group of bacteria known to cause subacute bacterial endocarditis. It is asaccharolytic, oxidase- positive bacilli that do not grow on MacConkey Agar and produces a BLEACH-LIKE odor. It is often assoc. with wounds of the mouth or teeth
Eikenella corrodens
60
The bacterial species that can be described as oxidase-positive, glucose-positive, maltose-positive, sucrose-negative, lactose-negative, and a major cause of bacterial meningitis
Neisseria meningitidis
61
The bacterial species that can be described as oxidase-positive, glucose-positive, maltose-negative, sucrose-negative, lactose-negative, and a major cause of venereal disease
Neisseria gonorrhea
62
Gram stained appearance of the genus Neisseria
Gram-negative diplococci
63
The Hugh-Leifson oxidative fermentative (OF) test shows a pH shift in the open glucose tube and no pH in the closed tube. this indicates this organism is an:
Oxidizer or Nonoxidizer?
Oxidizer
64
This is a critical test when attempting to identify nonfermenting gram-negative bacilli
Oxidase Test
65
The oxidase test is designed to determine the presence of this enzyme. This enzyme is also a part of the energy transfer cascade of intermediate metabolism.
Cytochrome oxidase
66
The blood culture of a patient with a central venous catheter yielded a gram- negative bacillus (NLF) growing on MacConkey agar, green-lavender or yellow pigment on chocolate agar and blood agar, oxidase (-), catalase (+), and esculin (+). This organism strongly oxidizes maltose but only weakly oxidizes glucose
Stenotrophomonas maltophila
67
This organism is associated with Meliodosis
Burkholderia pseudomallei
68
Differentiation of Stenotrophomonas maltophila and Burkholderia cepacia is best accomplished by which test?
Oxidase test
Stenotrophomonas: Oxidase (-)
Burkholderia: Oxidase (+)
69
The respiratory culture of a patient with cystic fibrosis yielded a gram-negative bacillus, Oxidase (+), Soluble green pigment on TSA slant, Motility (+)
Pseudomonas aeruginosa
70
Which test group best differentiates Acinetobacter baumannii from Pseudomonas aeruginosa
Oxidase, Motility, Nitrate reduction
Pseudomonas: Oxidase (+), Motile
Acinetobacter: Oxidase (-), Nonmotiel
71
Cystic tryptic Agar (CTA) sugar reactions are used to differentiate Neisseria spp. If Moraxella catarrhalis is tested in this system, the isolate will be
Glucose, Maltose, Lactose, and Sucrose NEGATIVE
72
A soluble, bright green pigment produced by Pseudomonas aeruginosa is known as
Pyocyanin
73
A small portion of a colony of a gram-negative bacilli was smeared onto a filter paper test system. One percent tetramethyl-p-phenylenediamine dihydrochloride was added. At 10 secs, a dark purple color developed. What does this test result exhibit?
Positive oxidase Test
74
Characteristics of both Mycoplasma and Ureaplasma genera
They only have a cell membrane with no cell wall
75
What organism causes Nongonococcal Urethritis (NGU)
Ureaplasma urealyticum
76
This is the most sensitive method for the diagnosis of Chlamydia trachomatis
Nucleic Acid amplification
77
This is the most common rickettsial disease in US and characterized by abrupt onset of fever headache and muscle aches, rash beginning on hands and feet spreading toward the trunk. Diagnosis includes fluorescent antibody or PCR
Rocky Mountain spotted fever
78
Which stage of venereal syphilis is characterized by the appearance of a chancre that typically heals within 6 weeks?
Primary syphilis
79
It is nontreponemal serologic test in which soluble antigen particles are coalesced to form larger particles that are visible as clumps when they are aggregated by antibody?
Venereal Disease Research Laboratory (VDRL) test
80
Lyme disease with signs of partial facial paralysis and painful joints is caused by which infectious agent
Borrelia burgdorferi
81
A lesion in the groin area, lack of demonstable organism in the lesion by gramstained smear, and reactive in RPR test can be diagnosed as syphilis caused by?
Treponema pallidum
82
Under anaerobic incubation conditions, it grew as smooth, white nonhemolytic colonies. This organism was not inhibited by colistin, kanamycin, or vancomycin, and hydrolyzed esculin.
Bacteroides fragilis
83
Pseudomembranous colitis caused by Clostridium difficile is best confirmed by what laboratory finding?
Presence of the toxin in stool
84
Lecithinase production, double zone hemolysis on SBA and gram-stained morphology are all useful criteria in the identification of?
Clostridium perfringens
85
The most common way to confirm that an anaerobic system has the correct gas mixture
Change in color of the methylene blue indicator.
86
In a clinical specimen from neck, mouth or resp tract, the presence of sulfur granules strongly indicates the presence of which anaerobic bacterium?
Actinomyces spp.
87
These are a common element between using the E test and agar disk diffusion (Kirby-Bauer) for antimicrobial susceptibility testing
Both establish an antibiotic gradient in agar
88
What clinical condition would most benefit from having quantitative (MIC) testing rather than quantitative (Sensitive, Intermediate, Resistant categories) data from the laboratory?
Bacterial meningitis (from CNS)
89
The lowest concentration of an antibiotic in dilution series that inhibits growth
Minimium Inhibition Concentration
90
The higher the MIC of the drug for that organism; The _____ is the zone of inhibition
The larger is the zone of inhibition
91
Infection and/or inflammation of the terminal portion of the lower urinary tract
Urethritis
92
Strptococcus pneumoniae commonly associated with Otitis Media is positive with
Optochin
93
Organism most often responsible for Impetigo
Streptococcus pyogenes
94
How do staphylococci spread so easily when infecting the skin?
They produce Hyaluronidase, which hydrolyzes hyaluronic acid in the intracellular ground substance that makes up connective tissue
95
Routine culture media for use with a specimen of CSF should include whic sets of media?
5% SBA, Chocolate Agar Thioglycolate broth
96
Clinical symptoms include fever, intense headache, stiff neck, sensitivity to light and low WBCs. This is diagnosed as meningitis. What tests hould be ordered next?
CSF Gram Stain and culture
97
What cells are found in bacterial vaginosis?
Clue cells
98
Which term is used to describe an increase of lymphocytes and other mononuclear cells (pleocytosis) in the CSF and negative bacterial and fungal cultures?
Aseptic meningitis
99
The culture of which sample routinely uses quantitation or the counting of bacterial cells present to assist in the interpretation? This is done to aid the differentiation of true infection from contamination
Urine
100
These practices are done to ensure that the test results are accurate.
Quality Control
101
The overall process of ensuring the quality of the results reported by the laboratory and includes quality control, employee training, and certification.
Quality Assurance
102
Substances known or reasonably expected to contain pathogens
Infectious substances
103
An example of inappropriate specimen or condition that would warrant rejection for microbiology culture
A 24-hr urine sample for bacteriology culture
