microbiology practicum (bacteria)

Staphpylococcus general features

Gram positive cocci, clusters

Facultative anaerobe

Beta hemolytic

Staphylococcus aureus diseases

Cutaneous(folliculitis, furuncle, carbuncle, impetigo)

Deep lesions (cellulitis, wound infections)

Scalded skin syndrome

Food poisoning

Toxic shock syndrome

Staphylococcus aureus testing

Mannitol salt agar (Ferments mannitol)

Catalase positive

Coagulate positive

Staphylococcus epidermidis diseases

Nosocomial infections

Bacteremia (tough to interpret)

Endocarditis

Stitch abscesses

Staphylococcus epidermidis testing

No hemolysis

Catalase positive

Coagulase negative

Novobiocin susceptible

Staphylococcus saprophyticus diseases

UTI in sexually active women

Urine cultures may be found in low numbers (clinically significant), high culture numbers may mean contamination

Staphylococcus saprophyticus testing

No hemolytsis

Catalase positive

coagulase negative

Novobiocin resistant

Streptococcus general features

Gram positive cocci, chains

Aerotolerant

Streptococcus pyogenes diseases

Pharyngitis, impetigo, erysipelas, pureperal fever

Scarlet fever

Toxin shock like syndrome

Acute rheumatic fever, acute glomeruloephritis

Streptococcus pyogenes testing

Beta hemolytic

Catalase negative

Bacitracin susceptible

Streptococcus agalactiae diseases

Leading cause of pneumonia, sepsis, meningitis during first 2 months of life

Streptococcus agalactiae testing

Beta hemolytic

Catalase negative

Hippurate hydrolysis

CAMP

Steptococcus pneumoniae diseases

Pneumonia (rusty pink sputum)

Most common cause of meningitis in elderly adults

URT infections

Streptococcus pneumoniae testing

Alpha hemolytic

Catalase negative

Optochin susceptible

Enterococcus and group D strep diseases

Opportunistic infections

Often associated with bacteremia

Wound and soft tissue infections

Endocarditis from prosthetic or in dwelling devices

Vividans strep diseases

Most common cause of subacute endocarditis

Endocarditis from dental procedures

Abscesses orofacial or brain

Viridans strep testing

Alpha hemolytic, some are non-hemolytic

Catalase negative

Optochin resistant

Cannot hydrolyze BE

Corynebacterium general features

Gram positive rods

Facultative anaerobe

Pleomorphic

Corynebacterium diphtheriae diseases

Diphtheria

Bullneck

Humans are the only reservoir

Corynebacterium diphtheriae testing

Beta hemolysis

Toxin detection

Arcanobacteria haemolytoicum

Gram positive rod

Catalase negative

Beta hemolysis(narrow zone)

Lipase and lecithinase positive

Rhodococcus equi

Found in soil

Partially acid fast

Does not ferment carbohydrates

Rothia

Gram positive rods, branching filaments

Nitrite positive

Urease negative

Listeria monocytogenes general features

Gram positive coccobacilli

Facultative anaerobe

Pleomorphic

Tumbling motility

Listeria monocytogenes diseases

Causes listeria

In late onset neonates most likely to manifest as meningitis

Listeria monocytogenes testing

Beta hemolytic

Catalase positive

Hippurate positive

Bile esculin positive

Positive camp

Erysipelothrix rhusiopathiae general features

Gram positive slender filamentous bacilli

Pigs are main reservoir

Brush pattern at 22 C in gelatin stab cultures

Eryispelothrix rhusippathiae diseases

Endocarditis

Eysipeloid

Septicemia

Erysipelothrix rhusiopathiae testing

Alpha hemolytic

Catalase negative

H2S production

VP negative

Lactobacillus acidophilus general features

Gram positive

Facultative anaerobe

Highly Pleomorphic

Natural flora of female urogenital tract

Lactobacillus acidophilus testing

Alpha hemolytic

Catalase negative

Bacillus general features

gram positive bacillus

aerobic

sopre forming

bacillus anthracis diseases

cutaneous (black scar, eschar, erythematous ring)

woolsorters diseases

bacillus anthracis testing

non-hemolytic

swirling projections (medusa head)

catalase positive

non motile

bacillus cereus diseases

food poisoning

opportunistic infections

bacillus cereus testing

beta hemolytic

motile

catalase positive

produces lechithinase

aerobic actinomycetes

branching filamentous hyphae

non spore forming

not commonly seen in US, but can cause significant human disease

Nocardia

gram positive rods

weakly acid fast

very slow growth

neisseria general features

gram negative diplococci

aerobic

usually intracellular

grows on CHOC, thayer martin, martin lewis

neisseria gonorrhoeae diseases

gonorrohea (genital, rectal, pharyngeal)

pelvic inflammatory disease

disseminated gonococcal infection

neisseria meningitidis diseases

meningitis

nasopharyngeal infections

bloodstream infections

moraxella catarrhalis general features

gram negative coccobacilli or diplococci

asaccharolytic

isolated only from humans

hockey puck apperance

kingella denitrificans

reduce nitrates

normal flora or URT

catalase negative

oxidase positive

haemophilus influenzae general features

gram negative coccobacilli

facultative anaerobe

ferments carbohydrates

satellitism

requires choc agar to grow

haemophilus influenzae diseases

acute meningitis in children

epiglottis in children 2-4 years old

pneumonia in older patients

haemophilus influenzae testing

catalase positive

reduce nitrates to nitrites

haemophilus ducreyi

not normal flora

causatuve agent of chancroid

grows best in 33 and requires media such as GC that contains vancomycin to reduce growth of normal flora

aggregatibacter actinomycetemcomitans general features

gram negative rods (mucoid)

slow gowth (2-3 days)

star formation in center of colony

aggregatibacter actinomycetemcomitans testing

fermenter with addition of serum to media

catalase positive

negative for urease, indole, esculin, citrate

cardiobacterium hominis general features

gram negative pleomorphic rods

slow growth

forms rosettes or swelling

do not grow on mac

cardiobacterium hominis testing

ferments but needs serum

oxidase positive

indole positive

negative for urease, nitrate, gelatin, esculin, and catalase

eikenella corrodens general features

gram negative

slow growth

odor of bleach

do not grow on MAC

eikenella corrodens testing

catalase negative

oxidase positive

asaccharolytic

capnocytophaga spp

gram negative rods

spreading colony morphology

oxidase negative

do not grow on MAC

pasteurella multocida

gram negative coccobacilli or rods

nonhemolytic

from animal scratch or bite

indole and ONPG positive

acid butt TSIA

brucella general features

gram negative coccobacilli

non spore forming

non motile

slow growth

brucellosis, undulant fever, malta fever

brucella testing

catalase and oxidase positive

nonfermentative

urease positive in 2 hours

H2S

franciesella tularensis

gram negative coccobacilli

category A bio agent

bipolar staining

tularemia, rabbit fever

will not grow on routine media

bordetella pertussis

gram negative coccobacilli

whooping ocugh

bordet gengou

does not ferment carbohydrates

legionella pneumophilia

gram negative coccobacilli

motile

legionnaires disease

growth on BYCE not BAP

salmonella

non-lactose fermenters

H2S production

indole, VP, PAD, urease negative

ingestion of contaminated food

shigella

not part of normal flora

causes bacillary dysentery

humans only known reservoir

low infective dose

yersinia pestis

short rod

non motile

methylene blue or wayson stain will show bipolar staining

bubonic plague

yersenia entercolitica

cold enrichment for better growth

motile at 25C but not 35C

most common yersinia species isolated from humans

mimics appendicitis

CIN media

klebsiella pneumoniae

nonmotile

most commonly isolated species

moist, mucoid colonies

lactose fermenter

urease positive, indole negative

enterobacter

lactose fermenter

DNase negative

motile

indole, methyl red negative

VP and citrate positive

serratia

opportunisitic pathogens associated with nosocomal infections

most are slow lactose fermenters (ONPG positive)

highly resistant to antimicrobials

citrobacter

ferment lactose and hydrolyze urea

growth on simmons citrate

positive methly red

C. freundii isolated from stool samples

H2S

Edwardsiella

negative for urea

growth on simmons citrate

positive for lysine decarboxylase

H2S

indole positive

proteus

swarming on blood agar

burnt chocolate odor

H2S and urease positive

morganella

PAD posititve

citrate negative

non lactose fermenter

UTI

providencia

highly resistant to antimicrobials

PAD and citrate positive

non lactose fermenter

escherichia coli

ferment glucose, lactose

indole and methly red positive

VP and citrate negative

uropathogenic (most common cause of UTI)

enterohemorragic (O157:H7)

Vibrio general features

facultative anaerobe

curved

oxidase positive

nitrate reduction

indole positive

gram negative

vibirostatic disk

vibrio cholerae

rice water stool

non-halophilic

sucrose fermenter

viribio parahaemolyticus

halophile (1-8% NaCl)

ingestion of raw seafood (oysters)

kanagawa phenomenon

vibrio vulnificus

halophile

lactose positive

predisposing risk factor: liver disease and high iron levels

ingestion of contaminated food (oysters)

vibrio alginolyticus

strict halophile (10% NaCl)

involved in eye, ear, and wound infections in contact with sea water

sucrose fermenter

aeromonas general features

grow at 4-42C

motile

season pattern: May through October

involves aquatic exposure

modified CIN agar

gram negative

aeromonas testing

oxidase positive

ferments glucose

resistant to vibriostat disk

pink on CIN agar

pseudomonas aeruginosa

beta hemolytic

grape odor

flat spreading colonies with metallic sheen

pseudomonas stutzeri

rare pathogen

non fluorescent

wrinkled, leathery that produce light yellow or brown pigment

acinetobacter

A. baumanii saccharolytic

A. lwoffi nonsaccharolytic

oxidase negative

catalase positive

purple hue on MAC

gram negative

stenotrophomonas maltophilia

gram negative

non normal flora but can colonize hospital patients respiratory tract

oxidase negative

catalase, esculin, DNase, gelatin hydrolysis positive

susceptible to SXT disc

burkholderia cepacia

weak positive oxidase

oxidize glucose

isolated from irrigation fluids, disinfectants, anesthetics, nebulizers, detergents

burkholderia mallei

glanders disease

bioterror agent A

rare disease that can cause pulmonary infections

burkholderia pseudomallei

white wrinkled colonies

melioidosis: agressive granulomatous disease

bioterror agent

flavobacteriaceae

not part of normal flora

DNase, indole, gelatin, oxidase positive

chryseobacterium inologenes (most commonly isolated)

elizabethkingia meningoseptica (most diseases)

shewanella

rarely pathogenic

colonizers

isolated from abscesses and traumatic ulcers

H2S

oxidase positive

moraxella

oxidase positive

biochemically inert, asaccharolytic

strictly aerobic

M. catarrhalis resembles neisseria

M. atlantae does not grow on MAC

clostridium tetani

tetanus

gram positive rod

anaerobic

lock jaw, spasms of jaw, neck, trunk

clostridium botulinum

gram positive rod

anaerobic

lipase positive

botulinum toxin

raw honey

clostridium perfringens

gram positive anaerobe

boxcar bacilli

lecithnase positive

nagler reaction

double zone of hemolysis

gas gangrene

clostridium difficile

pseudomembranous enterocolitis

gram positive anaerobe

peptostreptococcus

gram positive cocci

anaerobe

normal flora of mouth

brain abscesses

cardiovascular infections from poor oral hygiene

bacteroides fragilis

gram negative

always resistant to penicillin

esculin and catalase positive

urease and indole negative

prevotella

gram negative anaerobe

growth on KVLB agar

resistant to kanamycin and vancomycin

some produce protoporphyrin and begin to pigment

porphyromonas

susceptible to vancomycin

does not grow on KVLB

indole positive

for some, shining UV light will reveal brick red fluorescence prior to brown pigment

fusobacterium

resistant to vancomycin, susceptible to kanamycin and colistin

fluoresce chartreuse color

spindle shaped with tapered ends

campylobacter general features

gull winged shaped

motile, darting motility using handing drop

microaerophilic

oxidase positive

requires 48 hrs for visible colonies