Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Compendium Microbiology > Micro Elsevier questions/answers > Flashcards

Micro Elsevier questions/answers Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What is the MIC

A

The lowest drug level that is bacteriostatic

Determined from serieal two-fold dilutions of each antibiotic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  • Recommended therapy for S pneumonia
  • Is a urinary antigen test available for S pneumonia?
  • Most virulent capsule type
  • Who is vaccine recommended for
A
  • penicillin G or 2nd or 3rd gen cephalosporin (must do susc because resistance is common)
  • Yes
  • Type 3
  • 23-polyvalent vaccine is available for patients > 65 and patients with chronic pulmonary, cardiac, liver, or renal disease, asplenia, sickle cell disease, diabetes, and immunocompromised
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What antibiotic is used to treat ESBL-producing bacteria

A

Carbapenems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Empiric therapy for G+ cocci in clusters

A

Vancomycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

serovars for lymphogranuloma venereum

A

L1, L2, L3 of C trachomatis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

virulence factors and treatment for listeria

A
  • Actins, hemolysins, and membrane proteins called internalins
  • Ampicillin (resistance is not common)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Quadrivalent menigococcal vaccine covers?

Recommended for?

A

A, C, Y, and W135 (C and W-135 are more common in industrialized countries); does not cover B because of poor immunogenicity

Recommended for military recruits, college freshmen, asplenic patients, children over 2 years, prisoners, and lab workers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Diagnosis of B henselae

Spectrum of diseases in people

Disease in cats

A
  • serology is best because it takes weeks to culture if it ever grows
  • cat scratch disease, endocarditis, bacillary angiomatosis, and neuroretinitis
  • intraRBC bacteremia in cats
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Shigella food born illness comes from what food

A

Contaminated water, vegetables

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Brucella

  • growth
  • oxidase result
  • urease result
A
  • no growth on MAC
  • takes 2 days to grow on BAP and chocolate
  • oxidase positive
  • urease positive

(also catalase positive)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

V vulnificus

  • lactose and sucrose fermentation
  • treatment
  • virulence factors
A
  • lactose fermenter; sucrose non-fermenter
  • tetracyclines or aminoglycosides
  • capsule, elastolytic protease, cytolysins, and collagenase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

gram-negative organisms contain large amounts of ____ which is degraded by acetone alcohol decolorization step in gram stain

A

lipopolysaccharide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Indole and ornithine decarboxylase positivity in Proteus species

Beta lactamase produced by which proteus species

A

P vulgaris is indole positive

P mirabilis is ODC positive

P vulgaris is intrinsically resistant to ampicillin due to chromosomal beta lactamase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

treatment for C diff

A

vancomycin or metronidazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Site of infection for whooping cough

A

nasopharynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does salmonella appear on XLD media

  • other agars used for salmonella
  • motility of salmonella
  • when to treat salmonella with abx
A

Black due to H2S

  • brillant green agar, HE agar
  • motile
  • treat with abx if infection spread beyond GI tract, if it is severe, or if patient is immunocompromised
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Staph lug

PYR and ODC status

methicillin resistance?

S schleiferi

A
  • PYR positive (unlike S aureus) and ODC positive (unlike other coagulase negative staph)
  • methicillin resistance is rare
  • S schleiferi is positive for PYR and negative for ODC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Acinetobacter baumanii

A
  • gram negative coccobacillus
  • non motile (although some research shows that they actually can be motile)
  • non lactose fermenter
  • oxidase negative
  • highly resistant to antimicrobial agents (multidrug resistance)
  • possible to treat with amikacin or tobramycin; polymyxin reserved for highly resistant isolates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Molecular strain typing methods in a hospital setting

A

(not MALDI-TOF; this only subtypes species)

  • used to determine if a cluster of infections in a unit is caused by the same strain
  • Methods:
    • pulsed-field gel electrophoresis with DNA fragments
    • random amplification of polymoprhic DNA
    • multilocus sequence typing
    • restriction fragment length polymorphisms
    • amplified fragment length polymorphism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

NAAT method

A

Uses PCR or transcription mediated amplification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Potential sequelae of bacterial vaginosis

A

Sequelae:

  • PID
  • cervicitis
  • endometritis
  • increased risk of HIV

Clinical diagnosis (need 3 of 4 of Amsel’s criteria):

  • clue cells
  • positive KOH amine testing
  • pH > 4.5
  • watery, fishy vaginal discharge

Shift in flora from mainly lactobacilli to bacteroides, prevotella,mobiluncus, gardnerella

Nugent gram stain is gold standard

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Biochemical differences between bacteroides, prevotella, and porphyromonas

A

Bacteroides is bile resistant

Prevotella is bile sensitive, pigmented, and saccharolytic

Porphyromonas is pigmented and asaccharolytic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Burkholderia cepacia complex

  • gram stain
  • biochemicals
A

slow growing nonlactose fermenting, gram negative bacillus

weakly positive oxidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

List of PYR positive staph

A

S haemolyticus

S lugdunensis

S saprophyticus

S schleiferi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Amp C

A

SPACE

Serratia

Proteus

Acinetobacter

Citrobacter

Enterobacter

Resistant to all beta lactam abx except carbapenems and cefepime (includes resistance to cefoxitin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

ESBL

A

Resistant to cephalosporins, but not cephamycins

E coli, Klebsiella, Proteus mirabilis

Clav acid inhibits ESBL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Strep dysgalactiae subspecies equisimilis

A

Common cause of pharyngitis in teens and young adults, as well as necrotizing fasciitis, cellulitis, and abscesses

Classification:

Large group C and G colonies have been reclassified as S dysgalactiae and the small group C and G colonies are classified as Strep anginosus, which can cause absesses

SDSE is VP negative, whereas the anginosus group is VP positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Carbapenemases

A

Grouped as molecular classes A, B, and D

Class A: KPC (K pneumoniae and other enterobacteriaceae including serratia); demonstrated with Hidge (clover leaf test): streak plate with carbapenem suscepitble E coli, place ertapenem disk in center and test organisms are streaked out from the disk; if KPC is present it will distort the zone of inhibition of E coli

Class B: metallo-beta-lactamases such as IMP, VIM, and SPM produced by pseudomonas, acinetobacter, stenotrophomonas maltophilia, and enterobacteriaceae

OXA carbapenamases are made by acintobacter baumannii

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Multiplex PCR assays detect what MRSA specific genetic regions

A

spa (Staphylococcal protein A)

SCCmec

mecA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Temperature at which P aeruginosa grows

A

42 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

CLSI requirements for susceptibility testing of bacteria

A

0.5 McFarland inoculum == 1-2 x 108 CFU/ml

Mueller Hinton agar

Ambient air incubation

If a new antibiotic is started, susc testing must be done for 20-30 days; if no more than 1/20 or 3/30 MICs for each antibiotic/organism is out of the acceptable range, then QC can be reduced to once per week

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Fusobacterium nucleatum colonies

A

white, rough, bread-crumb like

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Porphyromonas and prevotella colonies

A

black and fluoresce red

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Atmosphere for anaerobic incubation

A

85% N2, 10% H2, and 5% CO2

Need selective, enrichment, and nonselective media

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Anaerobes associated with brain abscesses

A

peptostreptococcus

fusobacterium

prevotella

porphyromonas

36
Q

If sexual abuse is suspected, what tests should be done?

A

NAAT for C trachomatis and N gonorrhoeae and serology for HIV

37
Q

Aerococcus viridans biochemicals

A

Can cause IE

alpha hemolytic

PYR positive

LAP negative

Susceptible to vanc

(other orgs in this group that are resistant to vanc include pediococcus, leuconostoc, globicatella)

38
Q

Closely related and possibly related outbreak strains with PFGE testing

A

If 2-3 bands differ, the strains are closely related

If 4-6 bands differ, the strains are possibly related

39
Q

MRSA can cause subcutaneous infections leading to necrotizing fasciitis with eschar

Community associated MRSA strains include USA300 and USA400

A
40
Q

Tests for detecting AFB directly in specimens

A

NAAT

Fluorochrome stain

41
Q

M marinum

chromogenicity

rate of growth

temperature of growth

A

Photochromogen, rapid grower at 30 degrees

42
Q

M haemophilum

chromogenicity

rate of growth

temperature of growth

A

Nonchromogenic

Slow growing

30 degrees

Needs iron

43
Q

M bovis and MAC

chromogenicity

rate of growth

temperature of growth

A

nonchromogenic

slow growing

37 degrees

44
Q

In a BCG vaccinated person, what test can be done to show that she is infected with TB

A

interferon-gamma release assay

45
Q

M Tb versus M bovis

A

M TB is niacin positive and bovis is negative

46
Q

M fortuitum versus M chelonae

A

Fortuitum uptakes iron and chelonae does not

Chelonae uses citrate and fortuitum does not

47
Q

Gold standard for molecular typing of M tuberculosis isolates

A

IS6110 (a transposable genetic element varying in location and number of repeats: 0-25) restriction length polymorphism analysis

(For strains with 6 or fewer copies of IS6110 spoligotyping can be done)

48
Q

Most common mycobacteria causing cervical lymphadenitis in children

A

MAC > M scrofulaceum (a scrotochromogen that is negative for niacin)

49
Q

Processing of mycobacterial specimens

A
  • All specimens must be procesed under a biologic safety cabinet (BSC) within a confined access facility
  • UV light is not required for sterilization or decontamination
  • There must be 6-12 negative air exchanges per hour
  • The BSC is in a controlled access area with the capacity to draw 75-100 linear feet of air per minute across the entire front opening for proper functioning of the HEPA filter
  • Annual fit testing for N95 or N100 mask
  • Skin testing or IGRAs are performed annually on technicians
  • Specimens must be centrifuged in aerosol-free safety cups with o-ring sealed closures for at least 15 minutes at 3000 g
50
Q

M xenopi

A

transmitted from water source or infected people

Pigmented, grow at 42-45 degrees and is arylsulfatase positive

51
Q

How is M avium transmitted

A

Inhalation or ingestion and NOT by person to person spread

52
Q

Pathogenicity of M gordonae

A

Non pathogenic

53
Q

M kansasii transmission and geographic distribution

A

Transmitted by inhaled aerosols, not person to person

Southern and Central US

2nd most common cause of non TB pulmonary disease (second to MAC)

Niacin negative

Nitrate positive

Catalase positive

54
Q
  • When can airborne isolation for possible TB patient be discontinued
  • who should be on airborne isolation
A
  • Another diagnosis is made that excludes TB and three sputum specimens are AFB smear negative and NAAT negative
  • Patients at high risk for TB should be on airborne isolation (i.e., negative pressure room with at least 12 exchanges/hour) and people entering the room should wear and N-95 mask
55
Q

When are DNA probe assays used on M TB?

NAAT testing in TB?

A

Probes are only used on cultured specimens and can identify to the species level

NAATs are never used to exclude TB as the definitive test; NAAT does not distinguish among the TB complex

56
Q

Agar that grows C gatii

A

canavanine glycine bromothymol blue agar turns blue

57
Q

Endothrix versus ectothrix hair invasion by fungi

A

Endothrix

T tonsurans; arthroconidia within hair shaft; does not fluoresce with wood lamp

Ectothrix

M canis and M gypseum; arthroconidia on hair shaft; does fluoresce with wood lamp

58
Q

Syncephalastrum racemosum

A

saprophytic fungus

45 degree dichotomous branching, but is pauciseptate and do not have phialides

59
Q

Use of a BSC is necessary for processing molds, not yeast

Tape or shrink seals are needed when using plated agar media; however, petri plates should not be used if C immitis is suspected

Negative pressure is not necessary for processing fungi

Do not do slide culture if dimorphic fundi is suspected

A
60
Q

Blood cultures are rarely positive in invasive aspergillosis infections

A
61
Q

A niger - otomycosis

A
62
Q

Risk factors for Malassezia infection

A

total parenteral nutrition (high in lipids)

skin diseases

63
Q

Most common dermatophyte in feet and nails

A

T rubrum

64
Q

testing for candida that can be performed directly on blood culture

A

PNA (peptide nucleic acid) FISH assay - targets 26S rRNA sequences

65
Q

HAART should be given to

A

HIV load of > 100,000 and should be tested 2-8 weeks following therapy, then 3-4 months after that

66
Q

P marnefii is inhibited by

A

cyclohexamide

67
Q

Liver injury in HBV is immune mediated (not from virus particles themselves)

A
68
Q

HIV qualitative PCR

A

used to diagnose, not follow HIV patient

used if ELISA is positive and Western blot is negative

69
Q

DFA is one method for detecting HSV (turn around is 2 hours)

A
70
Q

High-risk infants can get monthyl RSV prophylaxis via injected palivizumab

A
71
Q

Influenza treatment

A

Should start within 2 days of infection

Oseltamivir and zanamivir treat A and B (neuraminidase inhibitors)

Amantadine treats A only

72
Q

Differences in Influenza A and B

A

A and B differ by matrix (M) and nucleoprotein (NP)

A viruses are further classified by H and N proteins

A infects animals and humans whereas B only infects humans

73
Q

VZV vaccine

A

Live, attenuated

given at 1 year if not immunocompromised

given for adults > 50 yo

74
Q

Roseola rash

A

Starts on trunk and spread to extremities and face

75
Q

Norwalk virus is highly infectious and survives on fomites

A
76
Q

HPV cannot be cultured in vitro and transmission occurs through epithelium-epithelium contact (not fluids)

A
77
Q

Rapid antigen detection tests are available for C diff, Giardia, Cryptosporidium, E histolytica, rotavirus, adenovirus 40/41

A
78
Q

Amblyomma tick anal groove versus Ixodes

A

Amblyomma has posterior anal grove, and Ixodes has anterior anal groove

79
Q

EDTA tube used for specimen preservation in malariae diagnosis

A
80
Q

Acanthamoeba does not have a flagellated form, whereas naegleria does

A
81
Q

Symptoms of trichinella:

  • first GI
  • after 2 weeks: muscle pain, fever, facial swelling (e.g., periorbital edema)

All stages of T spiralis development occur in a single host

Ingest larvae that invade small bowel wall where they become adults that release more larvae a week later. The larvae then migrate to striated muscle and encyst.

A
82
Q

Malaria positive blood donors have to wait three years before they can donate again

A
83
Q

Oral chloroquine is a treatment for P falciparum in regions where it is not resistant

Resistant regions are in Africa, South America, and South East Asia

A
84
Q

Cysticercosis occurs with ingestion of T solium eggs

(T solium has 7-13 uterine branches, whereas T saginata has 15-20)

A
85
Q

Stool preservatives for permanent micro exam:

  • Polyvinyl alcohol
  • Refrigeration for up to 3 hours
  • Sodium acetate-acetic acid formalin (SAF)
  • merthiolate iodine formalin (MIF)

Do not use ethanol (this is used for DNA extraction and not for morphological exam)

Should examine three stools (one per day or every other day)

Liquid stool should be examined fresh within 30 minutes, soft stool within 1 hour, and formed stool within 1 day

A

Compendium Microbiology (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions