UPDATED & FINAL Microbiology Polansky Cards, Clinical Laboratory Science Review (Micro), Clinical Microbiology Review - from Quick Review Cards for Medical Laboratory Science, 2nd Edition. Valerie Dietz Polansky, MEd, MLS (ASCP)

Cause Toxic Shock syndrome and food poisoning

S. aureus (cutaneous infections)

S. aureus is resistant to what antibiotic?

Penicillin

Common cause of hospital acquired UTI

Coagulase-negative staphylococci (CNS)

What is the hemolysis of S. aureus

Beta hemolytic

Novobiocin susceptible

S. epidermidis

Coagulase negative, Novobiocin Resistant Staphy

S. Saprophyticus

How does the catalase test work

Converts hydrogen peroxide to oxygen and water

Describe the pathogenicity of Group A Strep

Group A Strep (Strep Pyogenes)

1. Strep throat

2. Rheumatic fever

3. Glomerulonephritis

Oval GPC in chain and clusters

Streptococcus spp

Hemolysis of Group A Strep

Usually Beta heolytic ( wide zone)

What lysis RBCs, Platelets, and Neutrophiles in Group A Strep

Streptolysin O and Streptolysin S

To detect species that produce streptolysin O only, what must be done?

Stab into agar and place a coverslip over inoculum or incubate anaerobically

Group A is sensitive to what antibiotic?

Bacitracin

Group A is resistant and positive to?

Resistant to SXT and Positive to PYR

Most common cause of neonatal septicemia and meningitis

Group B Strep ( S. agalactiae)

Group B Strep:

Resistant to?

Positive?

Resistant to Bacitraacin/SXT

Positive for: Sodium Hippurate/CAMP

S. bovis is part of what Lancefield Group

Group D Streptococci

Group D Strep nonenterococci is normal ----and --- flora

fecal

oral

Lancefield group D

Enterococcus

Enterococcus are

80%-----E. ---

15%----E.----

80% E. faecalis

15% E. faecium

Enterococcus

Hydrolyze Esculin----

Growth in 6.5% NaCl---

PYR----

Hydrolyze Esculin----Positive

Growth in 6.5% NaCl---Yes

PYR----Positive

What are the pathogenicity of S. pneumoniae

1. Labor pneumonia

2. Otitis Media

3. Meningitis

Gram Stain: Football Shaped

S. pneumoniae

What is the hemolysis of S. pneumoniae

alpha-hemolytic

S. pneumoniae Key Characteristics:

1. Bile Solubility

2. Optochin

1.Bile Solubility---Positive

2. Optochin:-----Sensitive

What causes subacute bacterial endocarditis

Viridan streptococci

Viridan streptococci Key Characteristics:

1. Bile Solubility--

2. Optochin---

Key Characteristics:

1. Bile Solubility-Neg

2. Optochin-Resistant

Lysostaphin is used to differentiate Staphy from what other genus

Micrococcus

Fermentation of glucose (OF tube ) helps differentiate Staphy from?

Micrococcus

What other Staphy species in addition to S. aureus produces a coagulase positive result

S. intermedius

Slime production is associated with what Staphy species

S. epidermidis

What enzymes contribute to the virulence of Staphy?

Hyaluronidase: damages basement membrane of tissues

Beta-lactamase: produces strains that are able to inactivate penicillin and ampicillin

Acetoin production helps distinguish what two staphy strains

1. S. aureus (+)

2. S. intermedius (-)

Rhodotorula growth on SBA

Pink-orange/red pigment

Causative agent of pediatric tinea capitis but not in adults

Microsporum audouinii

Causes spontaneous abortions and meningitis in animals

Listeria Monocytogenes

What is the hemolysis of Listeria M

Beta Hemolytic

Translucent, gray

How does Listeria Monocytogenes look on CAMP

CAMP positive

-Shovel (not arrowhead)

Key Characteristics of L. monocytogenes

1. Catalase---

2. Esculin----

3. CAMP---

4. Motility on wet mount---

Key Characteristics of L. monocytogenes

1. Catalase---POS

2. Esculin----POS

3. CAMP---POS: Shovel

4. Motility on wet mount---Tumbling Motility

L. Monocytogenes: Growth difference at RT vs 35C

Umbrella growth in motility agar at RT but not at 35C

Motility of L. Monocytogenes diff from what

Diptheroids

Catalase test diff L. Monocytogene from what

Group B Strep

Diphtheriae is characterized by -------- formed by----- and ------ at the back of the throat

Diphtheriae is characterized by pseudomembrane formed by dead cells and exudate at the back of the throat

C. Diphtheria: Gray Black colonies with brown halos on what type of agar

Tindale agar

C. Diphtheria: Gray Black colonies what type of agar

Cystine tellurite

Loeffler medium stimulates growth and production of ------- granules in C. dihtheria

Metachromatic

Is C. diphtheria motile

No

Identifying characteristics on a gram stain of C. diphtheria

Chinese letters

The Elk test uses-----to detect ---- production for ------

anti-toxins, toxins, C. diphtheria

What is the pathogenecity of C. jeikeium

Hospital acquired

C. jeikeium is Rapid sucrose urea (RSU)?

Negative

What produces infections after prosthetic device implants?

C. jeikeium

Chopped meat broth is used for what organisms

Anaerobes

C. neoformans has a confirmatory growth on what type of agar

Niger seed (bird agar)

Cysticercosis is associated with what tapeworm?

Taenia solium.

What is the predominant anaerobic bacteria of the human colon

Bacteroides fragilis

What fungal infection causes chromomycosis

Phialophora verrucosum

Term "hydatid sand" is used in reference to what tapeworm

Echinococcus species

What is the historical medium of choice for Francisella

Cysteine blood glucose agar is the historical medium of choice for ----

What type of hemolysis does S. aureus have

Beta hemolytic

Gram positive bacteria has which acid in the cell wall

Lipoteichoic acid and Teichoic acid in the cell wall that prevents decolorization in the gram stain

Gram positive bacteria is stained by what dye?

Crystal violet

Gram negative bacteria is stained by what dye?

Safranin

List the 4 types of media

1. Supportive

2. Enrichment

3. Selective

4. Differential

Type of media: Supports growth of most non-fastidious bacteria

Supportive Media,

EX Nutrient Agar, TSA

Type of media: Contains added growth factors, e.g., blood, vitamins, yeast extract

Enrichment Media,

EX: SBA< Chocolate, Brain-Heart Infusion, Buffered charcoal-yeast extract agar

Type of Media: Formulated to provide distinct colonial appearances based on certain biochemical rxn (e.g., lactose fermentation, hydrogen sulfide [H2S] production)

Differential

EX: EMB, MacConkey, HE, XLD

Sheep blood agar (SBA)

Media: Most Non-fastidious bacteria

Chocolate agar (CHOC)

Media: Haemophilus and Neisseria

Columbia colistin-nalidixic acid agar (CNA)

Media: GP

Phenylethyl alcohol agar (PEA)

Media: GPC and anaerobic GNR

Group A-selective strep agar with 5% sheep blood (SSA)

Media: Group A Strep from respiratory source

Eosin methylene blue (EMB)

Media: Enteric GNR

MacConkey (MAC) agar

Media: Enteric Gram Negative Rods

Sorbitol MacConkey (SMAC) agar

Media: E. Coli 0157h7

Hektoen enteric (HE) agar

Salmonella & Shigellain stool

Xylose lysine deoxycholate (XLD)

Salmonella & Shigellain stool

Salmonella-Shigella (SS) agar

Salmonella & Shigellain stool

Gram-negative broth (GN)

Salmonella & Shigellafrom stools & rectal swabs

Deoxycholate-citrate agar

Salmonella & Shigella

Campylobacterbroth

Campylobacter from stool

Campylobacterblood agar (Campy BAP)

Campylobacter from stool

Causes suppurative cutaneous infections,

toxic shock syndrome, food poisoning

S. aureus

Opportunistic pathogen.

Commoncause of hospital acquired UTI

Coagulase-negative staphylococci (CNS)

UTI in young sexually active females, urethritis & prostatitis in males

S. saprophyticus

Usually nonpathogenic.

Found in environment & on skin, mucous membranes,

oropharynx

Micrococcus

Enzyme catalase converts 3% hydrogen peroxide (H2O2) to oxygen & water. Immediate bubbling.

Catalase Test

Staphylococci pos.

Streptococci & enterococci neg

Enzyme coagulase causes coagulation (tube test) or agglutination (slide test) in plasma.

Coagulase Test

S. aureus pos

Agglutination of latex beads coated with fibrinogen & abs to protein A (protein in cell wall of S. aureus).

Slide agglutination tests for S. aureus

S. aureus pos

Fermentation of mannitol results in color change from pink to yellow.

Mannitol salt agar (MSA)

-7.5% salt inhibits most organisms other than staph. All staph can grow on MSA. Rarely used for ID of

S. aureus today because other species ferment mannitol.

Organisms resistant to novobiocin grow to edge of disk.

Novobiocin susceptibility

-S. saprophyticus is resistant.

Other CNS susceptible

Causes 90% of strep infections.

Strep sore throat,

rheumatic fever,

glomerulonephritis,

scarlet fever (scarlatina),

erysipelas,

puerperal sepsis,

impetigo

Group A streptococci (GAS)

Sensitive to bacitracin.

Resistant to SXT. PYR pos

Most common is S. pyogenes.

Hemolysi due to O2-stable streptolysin S & O2-labile streptolysin O.

To detect species that produce streptolysin

O only, stab into agar, place coverslip over

inoculum, or incubate anaerobically

Normal flora of female genital tract.

Most common cause of neonatal septicemia & meningitis

Group B streptococci (GBS)

Resistant to SXT & bacitracin.

Sodium hippurate pos.

CAMP pos

S. agalactiae.

Vaginal & rectal swabs collected from pregnant women at 35-37 wk gestation.

Inoculated in selective

broth, e.g., LIM, GBS broth, StrepB Carrot Broth.

Normal in GI tract. Causes nosocomial

UTI, wound infections, bacteremia

Group D streptococci, nonenterococci

Hydrolyzes esculin

Most common is S. gallolyticus (formerly S. bovis).

Normal in mouth, GI tract, female genital tract. Causes nosocomial UTI, wound infections, bacteremia

Enterococcus

Hydrolyzes esculin.

Grows in 6.5% NaCl broth. PYR pos

Lancefield group D.

80% are E. faecalis,

15% E. faecium.

Normal in upper respiratory tract of some. Most

common cause of community acquired pneumonia.

Major cause of otitis media, meningitis in adults.

Infects sinuses, eyes

Streptococcus pneumoniae