Microbiology

gram +
cocci - grape like clusters
faculatative anaerobes
produce catalase
resistant to drying and heat
transmitted mostly by human to human contact

aureus (normal flora), epidermidis (skin), saprophyticus (skin, periurethra), lugdunesis (skin), haemolyticus (skin)

capsular polysaccharide
teichoic acid - aureus, epidermidis
petidoglycan - elicits humoral and cellular response
protein A - S. aureus - binds to fc protion of IgG - prevents phagocytosis
clumping factor - coagulase - s aureus
Altered pcn binding protein - mecA reduced ability to bind pcn

coagulase - s. aureus
catalase - all - convert h202 to water and oxygen
Hyaluronidase - s. aureus - spread through connective tissue
staphylokinase - digests fibrin clots
lipase
nuclease - aureus
penicillinase

alpha toxin - hemolytic and necrotic
beta - tissue destruction
delta - affects cell membrane
leukocidin - s ureous - attacks PMN
exfoliative - SSSS
Enterotoxins - A-E
TSST

beta hemolysis - yellowish and goldish - aura = yellow

coagulase +

s epidermidis and s. saprophyticus are non pigmented

Localized cutaneous - impetigo, furuncle, folliculities
SSS
TSS
food poinsoning
wound infections
Bacteremia, endocarditis, pneumonia, osteomylitis

Endocarditis
prosthetics and shunt infection

UTI - resistant to novobiocin - used to clinically dx

native valve endocarditis

gram + cocci in pairs or chains

lactic acid producing

most virulent
superficial and invasive infections and post infectious sequelae

capsule - antiphagocytic but not antigenic

bacitracin sensitive
B hemolytic
M protein - antiphagocytic
lipoteichoic acid - adhesion

streptolysin ) - lyses RBC

streptokinase - degrades fibrin
streptodornase - degrades dna
hyaluronidase
pyrogenic exotoxins
C5a peptidase
protease

A, B, C- includes erythrogenic toxin -> scarlet fever- phage mediated

pharyngitis - if phage gene expressed leads to scarlet fever

Impetigo -

puerperal sepsis - obstetrical infection

erysipelas and necrotizing fascitis

lymphangitis

streptococal sepsis and toxic shock syndrome

acute post streptococcal glomerulonephritis - due to immune complex formation in glomeruls - can either be from pharyngitis or impetigo

acute rheumatic fever - from pharyngitis - arhritis, carditis,

Beta hemolytic

CAMP test to identify

#1 cause of neonatal sepsis and meningitis and maternal obstetric infection

normal flora of intestine

gamma hemolytic

bile esculin - can tolerate small intestinal environment

6.5 nacl can grow

uti, peritonitis, subacute bacterial endocarditis

difficult b/c resistant - VRE

resistant to cephalosporins

alpha hemolytic

normal flora of upper respiratory tract

most common cause of subacute bacterial endocaridtis

dental work

both alpha hemolytic - pneumo is bile soluble and is clear

pneumo is optochin sensitive

most people harbor in oral cavity

lancet shaped diplococci

capsule is major virulence

to determine what type of capsule

lobar pneumonia
otitis media - most common cause
sepsis -
menigitis - most important cause

gram - cocci

aerobic non motile, non spore forming

oxidase positive

gonorrhoeae - production of acid from glucose
menigitidis - glucose and maltose
lactamica - glucose, maltose, lactose
sicca - glucose, maltose, lactose, sucrose

diplococcus

polysaccharide capsule

pilli

lipooligosaccharide, outer membrane proteins

bacteremia w/out sepsis

meningococcemia w/out meningitis

meningitis

septicemai with menigitis

grows on chocolate agar

thayer martin medium - contains vancomycin, colistin, nystatin

do not have polysaccharide capsule

have pilli

lipooligosaccharide

gram positive rod
aerobic
spore forming
produce exotoxins
only bacteria with PROTEIN capsule

A - active component - toxic

B - binding component - a component cannot enter the cell without it.

protective antigen (PA) - the b component

Lethal factor - binds and cleaves intracellular sinaling leading ot cell death. induces secretion of pro inflammatory cytokines TNF,

Edema factor - elevated intracellular cAMP - electrocyte loss

sores - most common route - papule progresses to an ulcer - surrounding tissue edema

GI - very rare in US - begins with ulcer -> sepsis

inhalation - initial flu like symptoms, mediastinal lymphadenopthy, edema sepsis shock - mortality 80%

emetic toxin - rice - heat stable, 1-6 hour onset, resolves quickly

diarrheal toxin - meat and veggies- heat labile - bacteria formed after ingestion - onset 18-24 hours later

not part of the normal flora

filamentous

aerobic

urease positive

catalase positive

bronchopulmonary caused by inhalation - usually immunocomprimised - brain absesses

cutaneous lesions

filamentous

non spore forming

sulfur granules in tissues

found in normal flora of female genital tract, respiratory

abscesses connected by sinus tracts

cervicofacial

pelvic

gram + rod

aerobic

grows on loefflers or potassium tellurite media

non invasive - needs lysogenic beta phage

inhibits protein synthesis, affects the heart, nerves tubular necrosis

bacteremic disease in cancer patients

cavitary pneumonia in patients with immune suppression

coccobacillus gram+

no spores
aerobic

beta hemolysis
+CAMP

listeriolysin O

meningitis in the elderly

menigitis in newborns

septicemia in pregnant women

gram - bacillus

aerobic

cysteine and iron

pneumonia - lobar - slow progressing

pontiac fever

gram - coccobacillus

aerobic

intracellular pathogen - survive inside macrophages

acute and chronic diseases

fever, liver, spleen, CNS, bone

milk products

abattoir workers

igM, igG titers rise

gram - rod

capsular antigen F1

v/w antigen

gram - rod

cysteine

rabbit reservoir

lesion develops at point of entry, lymph nodes, blood stream, liver/spleen/lungs

in contaminated food - hides in monocytes makes tx with antibiotics difficult

normal flora resp tract of animals and birds - humans can become infected after bite

faculatative gram - rods

ferment glucose

generally oxidase negative

proteus - UTI
e - enterbacter - abdominal absesses
s - shigella
c - citrobacter
k - klebsiella - UTI, abdominal absess, pneumonia
y - yersinia - diarrhea

e - e coli - diarrhea
s - serratia
s - salmonella - diarrhea

ecoli, shigella, salmonella, yersinia

klebsiella, ecoli, enterobacter

proteus, e coli

klebsiella

o antigen - somatic antigen
k - capuslar
h - flagellar

cytotoxins, enterotoxins, endotoxins, capsules, plasmids

travelers diarrhea
uti
neonatal menigitis

enterotoxigenic ETEC - watery travelers diarrhea

enterinvasive EIEC - febrile, severe diarrhea - similar to shigella

enterohemmorrhagic - afebrile, blood

never part of normal flora

does not ferment lactorse - produce h2s

similar to EIEC - invade and release shiga toxin

proteus - UTI
e - enterbacter - abdominal absesses
s - shigella
c - citrobacter
k - klebsiella - UTI, abdominal absess, pneumonia
y - yersinia - diarrhea

e - e coli - diarrhea
s - serratia
s - salmonella - diarrhea

ecoli, shigella, salmonella, yersinia

klebsiella, ecoli, enterobacter

proteus, e coli

klebsiella

o antigen - somatic antigen
k - capuslar
h - flagellar

cytotoxins, enterotoxins, endotoxins, capsules, plasmids

travelers diarrhea
uti
neonatal menigitis

enterotoxigenic ETEC - watery travelers diarrhea

enterinvasive EIEC - febrile, severe diarrhea - similar to shigella

enterohemmorrhagic - afebrile, blood

never part of normal flora

does not ferment lactorse - produce h2s

similar to EIEC - invade and release shiga toxin

vi factor = k antigen

never part of normal flora

typhoid fever

carrier state

sepsis

gastroenteritis

acid fast

aerobic

acid fast stain of sputum

- most rapidly fast destroyed - usually takes 8 weeks to culture

media - lowenstein - egg yolk and malchalite green

INH, rifampin, pyrazinamide

very common cause of infection in patients with hiv

fevers, diarrhea, weight loss

tuberculoid - low infectivity, few skin plaques, patients make a th1 response

lepromatous - high infectivity, disfiguring, make th2 response

gram + rod
spore forming
anaerobic
exotoxins

mycobacteria
bacillus

gas gangrene, tetani, botulism, difficile

gas gangrene, anaerobic cellulitis, food poinsoning

alpha toxin - lecithinase - disrupts cell membranes

theta toxin - hemolytic

enterotoxin - food poinsoning

incubation 4 days to 3 weeks

generalized muscle spasms

tetanospasmin

intracellular neurogenic toxin, heat labile, antigenic

tennis raquet shaped, gram + rods, anaerobic

incubation 18-96 hours

flaccid paralysis

infant - injest spores and they proliferate in non immune competant digestive tract - adults - contaminated food

heat labile - destroyed rapidly

resistant to gi enzymes

eight serological toxins A, B, E

usually in normal flora

usually after given antibiotics in hospital setting

A - enterotoxin - damages intestinal mucosa

B cytotoxin - inhibits protein synthesis

gram - rod, found in normal gut flora

filamentes gram + rod, normal oral flora

gram + mrod, normal skin flora, infection of prosthetic joints

gram + coccus - normal flora

pleuropulmonary disease, brain absesses, and obstetric and gynecological infections

gram - rods
aerobic
non spore
flagella
oxidase +

most common

water bug

produces exotoxin and endotoxin

common cause of hospital infections after leukemia, burns, cystic fibrosis

pneumonia, chronic cellulitis, whirlpool folliculitis, cornea lesions

gram - coccobacillary

capsules - 6 types a-f (most invasive is type b)

requires NAD and hematin to grow

satellite test - can grow around staph aureus on blood agar plate, releases x and v

normal respiratory reserve

meningitis - used to be most common cause before vaccination

epiglottis - has become more rare

bronchitis and otitis media- non capsulated strains

pneumonia - cause in young children

conjuntivitis

soft chancre - veneral disease

non specific vaginitis - clue cells

all produce respiratory syndromes

gram - coccobacillus
aerobe
encapsulated

elicits lymphocytes (unusual for bacteria)**

promotes attachment to respiratory epithelium

sensitizes to histamine - over response

1st phase - low grade fever
progressive cough
highly infectious - lasts 1-2 weeks
organism most easily isolated

2nd stage - eplosive cough with whoop
infectious
lymphocytosis
organism harder to isolate
lasts 2-4 weeks

4-8 weeks
gradual decline in cough
lifelong immunity
least infectious
organism seldom isolated

helical gram - bacteria

Treponema, borrelia, leptospira

syphilis - sexual contact or across placental

humans are only natural host

extremely labile

enters through minor abrasions on skin, 3 week incubation period

primary - development of painless chancre

spirochetes enter the blood and lymphatics

chancre disappears 3-6 weeks

2weeks after chancre heals

flu like - lymphadenopathy

rash or lesions on entire body - highly contagious

organisms replicate in lymph nodes, joints, liver, muscles, skin

rash disappears 2-10 weeks

warty lesions around anus condylomatalata

diffuse chronic inflammation seenin 30% of cases - non infectious

gummas - granulomas in bone, skin

neurosyphilis - demylination of post columns

cardiovascular syphilis - heart failure

fetus susceptible after 4 monhth gestation

cv syph, hutchinson teeth, multi organ failure, abn facial shape

darkfield microscopy
RPR, VDRL

cannot culture on artificial medium

found in developing countries with poor hygiene, crowded

T pallidum endencium - oral cavity

pertenue, skin papillomatous

t carateum m- skin papule

can be cultured

flagella

lyme disease

primary lesion at site 3-30 days after bite - fever, muscle, joint pains - symptoms for months

5-15% nervous system and heart

non destructive arthritis with or without fever - may last several years - chronic CNS symptoms

elisa - w/ western blot for confirmation

relapsing fever

louse or tick

intermittant fever, headaches, myalgia, recur due to endotoxin

org found in blood - visualize directly in blood stream

Weils disease

L interrogans - urine of infected wild and domestic animals

initially flu like

can be isolated from blood in the first week - then in the urine

small gram - rods
intracellular parasites

endothelial cells - blood vessels always targeted

suck out ATP survive poorly in environment on own

s. eastern us - n carolina caused by R rickettsiae

2-4 days incubation
fever headache myalgia, rash

rash starts on extremities and works centrally

epidemic typhus

transmitted by louse

fever, headache, chills

rash first appears on trunk and moves inward

unsanitary crowded condition - wars

relapse of typhus after first attack due to fading immunity, lesser severity

IgG not igM

Coxiella burnetti

cells resistant to heat, cold, sunlight

reservoirs in sheep, goats, cattle - no reservoir - inhalation of contaminated soil

respiratory infection - intersitial pneumonia - no rash

can cause endocarditis

Bortonella henselae

smallest self repricating, no cell wall

in humans most are part of normal flora- adhere to mucousal surfaces

pnuemoniae, hominis, ureaplasma urealyticom

complex media needed fatty acids and chlosterol - can grow extracellulary

primary atypical pneumonia

8-15% pneumonia in school aged children

year round

u urealyticum and m hominis - aquired by sexual contact

might be linked to premature delivery and neonatal lung disease

usually clinical - specific antibiodies - not usually positive until 2-3 weeks

cold agglutinins - igM antibiodies agglutinate RBC at low temps usually positive

obligate intracellular parasite

similar to gram - bacilli but no peptidoglycan layer

based on elementary bodies - infectious extraclelular partcles and reticulate bodies

leading cause of blindness in developing countries

serotypes a, b ba, and c

transmission by flies, fingers, fomites

serotypes d-k

serotypes l1, l2, l3

inguinal lymphadenopathy

psittaci - pet shop employees - bird keepers - mild pneumonia

bronchitis, pneumonia, sinusitis