microbio summary

Azhar Gangat (ASUMS) 1

Organism Characteristics

Reservoir/ Transmission (T)/Predisposing Factors (PF)

Virulence Factors (VF)/ Pathogenesis (TX)

ClinicalFindings

Diagnosis

Staphaureus

G+

cocci

β hemolytic

catalase +

coagulase +

salt tolerant

mannitol fermenter

NF: nasal mucosa,skin

T: hands, sneezing, ham/canned meat, custard pastries, potato salad

PF: surgery, break in skin, foreign body (eg. tampons, sutures), neutropenia,IV drug abuse, CGD

1

VF: protein A,surface receptors (eg. teichoic acid), microcapsule, PG layer

2TX:enterotoxin,TSST,exfoliatin,leukocidins (α toxin,P-V leukocidin),enzymes

3

PYOGENIC (abscess):skin infections (+otits externa),sepsis,endocarditis, osteomyelitis,arthritis, post-surgical wound infections, pneumonia,abscess in any organ

TOXIGENIC (superantigen):food poisoning (1-8 hrs), toxic shock syndrome, scalded skin syndrome

4the most common cause of skin infections, food poisoning, osteomyelitis, 2nd for otits externa

blood agar

mannitol-salt agar

Staph epidermidis

G+

cocci

catalase +

coagulase –

novobiocin sensitive

NF:skin,mucous membranes

PF: prosthetic heart valves and joints, intravenous catheters

nosocomial

VF:glycocalyx

endocarditis (within 2 months of surgery, after→ S. viridans)arthritis,osteomyelitis,sepsis in neonates,peritonitis in renal failure

produce β lactamase

Staph saprophytics

G+

cocci

catalase +

coagulase –

novobiocin

community acquired

urinary tract infections (especially in sexually active young women)

2nd to E. coli in causing community acquired UTI


resistant

Strep pyogenes

G+

cocci

catalase –

group A

β hemolytic (clear zone)

bacitracin sensitive

NF:human throat,skin

T:respiratory droplets,direct contact

Antigens:

M Protein(SPAM)Strep. Pyogenes Antibody to M Prtn,

C Carbohydrate,polysaccharide capsule

16

Enzymes:hyaluronidase,streptokinse,DNase

17TX:erythrogenic toxin,pyrogenic toxin A,exotoxin B,streptolysin O,streptolysin S

18

PYOGENIC:phrayngitis,impetigo,Invasivenecrotizing fasciitis,cellulitis,erysipelas,sepsis, puerperal fever

TOXIGENIC:scarlet fever,toxic shock

IMMUNE-MEDIATED (non-suppurative):rheumatic fever,acute glomerulonephritis

19

2nd most common cause of skin infections after S. aureus

Strep agalactiae

G+

cocci

catalase –

group B

β hemolytic(clear zone)

bacitracin resistant

hydrolyze hippurate

Colonization:human vagina

PF:prolonged (>18 hrs) rupture of membranes in women who are colonized with this bacteria,<37 wk gestation, children of mothers lacking antibody to group B strep.,diabetes

T:

neonatal septicemia

meningitis (in 1st month)

24

the most common cause of neonatal sepsis and neonatalmeningitis, E. coli is 2nd

S. pneumonia: adult meningitis


cAMP test + newborns infected during birth

Strep pneumoniae

(pneumococcus)

G+

cocci lacent-shaped diplococci

catalase –

polysac.capsulated

α-hemolytic(green zone, caused by pneumolysin)

optochin sensitive

bile soluble

Colonization:human respiratory tract (no animal)

T:respiratory droplets

PF:CASMIRCirculatory problemsAlcoholismaSplenia Measles infectionInfluenza infectionRespiratory problems

VF:polysac. capsule,lipoteichoic acid,pneumolysin,IgA protease

25

pneumonia(with bloody rusty sputum)jelly-like sputum in Klebsiella,

26otitis media in children,sinusitis in children,meningitis in adults

Strep. pneumoniae is the most common cause of:pneumonia,adult meningitis,otitis media in children,sinusitis in childrenpneumonia in alcoholics

S. agalactiae: nenonatal meningitis

Also:purulent bronchitis,corneal ulcer (purulent discharge in conjunctivitis),pericarditis, sepsis

quelling reaction + (test for swelling of capsule)

blood agar

Strep viridians

S. sanguisS. mutans

G+

catalase –

α-hemolytic(green zone)

optochin resistant

bile insoluble

N F:human oropharynx

PF:damaged heart valves,dental surgery,poor oral hygiene

S. mutans:dental plaque

dextran:leads to dental caries

infective endocarditis (oral route):fever, heart murmur, anemia, embolic events, malaise , fatigue , anorexia, night sweats & weight lossurological instrument route: S. faecalis

after 2 months of surgery, before→ S. epidermitidis

dental caries

blood agar

Enetrococcus faecalis

G+

catalase –

group D

NF:human colon

R:urethra,female genital tract

UTI:dysuria (painful urination),burning urine,↑fear of urination, fever,discharge of ulcer


γ-hemolytic (no hemolysis)

growth in 6.5% NaCl or bile, pH 9, 45˚C

PF:GI or urinary tract surgery,indwelling urinary catheters,urinary tract instruments,

mostly nosocomial

Also:endocarditis (urological instrument route): during medical procedures on GI or U tract: E. faecalis→ blood stream→ previously damaged heart valves→ endocarditisoral route: S. viridans

can cause intra-abdominal and pelvic infection with S.bovis

S. bovis G+

Catalase-

group D

γ-hemolytic (no hemolysis)

no growth in 6.5% NaCl

NF:human colon

PF:carcinoma of colon

endocarditis:especially in patients with colonic carcinoma

Neisseria meningitidis

G -

oxidase +

kidney bean shaped diplococci

capsulated

maltose fermenter

Colonization:human nasopharyngeal area


VF:polysac. capsule,IgA protease,LPS

32

13 different serotypes (polysac. capsule):eg. A, B, Y, W-135

meningitis,(the most common cause between the ages of 2 & 18)

meningococcemia (Waterhouse-Friderichsen syndrome)

33

chocolate agar(37˚C, 5% CO₂)

Neisseria gonorrheae

(gonococcus)

G –

oxidase +

coffee/kidney bean shaped diplococci

R:human genital tract(sensitive to dehydration and cool conditions)

T:sexual contact,Infection of

VF:pili,LOS,IgA

Other VF’s:OPAPORRMP

gonorrhea:

Male:urethritis,proctitis,epididymitis

Female:cervicitis,

Thayer-Martin medium (chocolate agar containing antibiotics)


pili

glucose fermenter

newborns during birth

-dissemination also possible → septic arthritis

FBPLIP

salpingitis,PID→ sterility & ectopic pregnancy

37

Newborn:(2-5 days onset)purulent conjunctivitis (opthalmia neonatorum),→ blindness

Dissemination:the most common cause of septic arthritis in sexually active adults

Moraxella catarrhalis

G –

diplococci

close relative of Neisseria

NF:upper respiratory tract

otitis media,bronchitis,bronchopneumonia (elderly with COPD-chronic obstructive pulmonary disease)

Bacillus anthracis

G +

square-ended rod

spore formation

aerobe

capsulated

nonmotile

R:spores in:soil,animal skin,animal products (eg. wool, hair),contaminated meat

T:skin,mucous membrane,respiratory tract

VF:capsule(D-glutamase, not polysac.)

TX:exotixins:edema factor,lethal factor,protective antigen

47

anthrax:cutaneous (95%),pulmonary (4%),GI (1%)

48

not communicable person-to-person (ie. through respiratory droplets)

blood agar,

mediastinal widening in x-ray

Bacillus cereus

G +

rod

spore formation

aerobic

motile

R:rice,other grains

PF:Reheated fried rice (Chinese restaurants),Held warm (not hot) for long periods

TX:enterotoxins:emetic type,diarrheal type

emetic (1-6 hrs) -fried rice -S. aureus type -vomiting -abdominal pain

diarrheal (18 hrs) -meats, sauces -E. coli/ Clostridial type -watery diarrhea


Affect:GI tract

may cause:eye infections

2nd most common cause of food poisoning after S. aureus

Clostridium tetani

G +

rod(tennis racket/drum stick shaped)

spore formation

anaerobic

R:soil

PF:wound,skin breakage,skin-popping,infected mother may infect the newborn

poor blood supply in the necrotic tissue helps its growth

TX:Tetanospasmin (exotoxin): -blocks inhibitory mediators (eg. glycine, GABA, glutamic acid)

tetanus: -spastic paralysis -locked jaw (trismus) -violent muscle spasms -grimace(risus sardonicus) -increased reflexes -respiratory failure →death

neonatal tetanus: -enter through contaminated umbilicus or circumcision wound

difficult to culture

Clostridium botulinum

G +

rod

spore formation

anaerobic

R:soil,dust

T:canned/vacuum packed food without sterilization,green beans,peppers,mushrooms,smoked fish,drug abuse skin-popping ,honey for infants

TX:-preformed in can-labile (ie. inactivated by heating)

-blocks release of Ach

Adult (2-3 hours):wound botulism: -toxins produced at the side of the wound-weakness, dizziness, blurry vision, flaccid paralysis

Infant (2-3 days):Infant botulism (honey):-toxins produced in the gut-diplopia,-dysphagia,-respiratory muscle failure,-flaccid paralysis

not cultured,mouse protection tests

Clostridium perfringes

G +

rod

spore formation

anaerobic

R:soil

NF:colon, vagina

T:war wounds, automobile/motor

TX:lecithinase(α-toxin):-gas production-cell membrane damage→ hemolysis

wound infections:-pain,-edema, -cellulitis,-crepitation (gas presence)

also:hemolysis, jaundice, blood-tinged exudates

blood agar: double zone of hemolysis

egg-yolk agar: lecithinase presence


accidents,septic abortions,

food contamination

PF:reheated food, especially meat dishes

→shock & death

Food Poisoning (8-16 hours):watery (non-inflammatory) diarrhea, little vomiting

3rd most common cause of food poisoning after S. aureus and B. cereus

Clostridium difficile

G +

rod

spore formation

anaerobic

R:human colon

T:fecal-oral route

PF:antibiotics,chemotherapy

especially nosocomial

TX:exotoxin Aexotoxin B

(add glucose to G protein involved in actin filament polymerization→ depolymerization of actin→ death of enterocyte)

pseudomembranous colitis(presence of yellow-white plaques on colonic mucosa),

bloody/nonbloody diarrhea(the most common nosocomial cause of diarrhea)

ELISA tests

Listeria monocytogenes

G +

rod

arranged in V or L shapes

tumbling motility

facultative intracellular parasite

cold growth

loves lysosomes

β hemolytic(narrow clear zone)

R:animals,plants,soil

T:unpasteurized milk,contaminated vegetables,animal contact

Cold Growth:cheese, cabbage

PF:placenta/delivery,renal transplant,↓ cell mediated immunity

TX:listerolysin O: -similar to streptolysin O -degrades cell membranes

actin rockets:cell to cell movement

sepsis (granulomatosis infantiseptica),

acute meningitis (after 1-4 weeks),

gastroenteritis: -watery diarrhea, fever, headache, abdominal pain, little vomiting -caused by contaminated dairy products & undercooked meats

sepsis & meningitis in immunosuppressed,abortion,premature delivery

the most common cause of sepsis and meningitis in renal transplant patients and adults with cancer

blood agar

Corynebacteria diphtheriae

G +

rod (beaded

R:human upper respiratory tract

TX:diphtheria toxin:-inhibits protein

diphtheria: -inflammation of throat -thick, grey

volutin granules stain


appearance)

aerobic

non-motile

V or L shapes

T:air-borne droplets

PF:skin lesion,poor skin hygiene

synthesis by ADP-ribosylation of EF-2 (elongation factor)this toxin is also present in Pseudomonas

pseudomembrane (bull neck) -can lead to: -tracheal/ tracheal extension→ airway obstruction -myocarditis→ arrhythmia -recurrent laryngeal nerve palsy

metachromat-ically

blood agar

potassium tellurite agar

Actinomyces israelii

G +

rod (long branching filaments)

anaerobe

sulfur granules (hard, yellow coloured)

NF:gingival crevices(oral cavity),female genital tract

PF:upper body lesions/trauma (especially face & neck),intrauterine device retention for a long period of time

non-communicable

hard, non-tender swelling drains pus through sinus tracts

actinomycosis:

cervicofaical (lumpy jaw): -dental trauma, poor oral hygiene

pelvic form: -intrauterine contraceptive device (IUCD)

thoracic: -aspiration (removal) with contagious spread

abdominal: -surgery or bowel trauma

Nocardia asteroides

G +

rod (thin branching filaments)

aerobic

weakly acid-fast

R:soil,dust

T:airborne,trauma

non-communicable

nocaridiosis (pulmonary infections):

bronchopulmonary: -cough -fever -dyspnea -begins as pulmonary infection and may spread as abscess/ sinus tracts -immunocompromized: may spread to brain, skin, kidneys

cutaneous/subcutaneous: -cellulitis -granuloma -ulcer -swelling -starts with trauma

Mycobacterium tuberculosis

acid-fast(mycolic acids)

R:human lungs

-no toxin production

TB: -any part of the body could be affected except teeth

Lowenstein- Jensen medium


rod

aerobic

facultative intracellular

typical mycobacteria

slow growth

UV sensitive

pathogenic for guinea pigs


VF:lipid content,phosphatides,cord factor,sulfatides,PPD

73PF:poverty,HIV infection,IV drug abuse

-causes infection of macrophages and other RE-cells

-exported repetitive protein→ prevents fusion of phagosome and lysosome

-transmission through lymphatics→ lymphadenopathy (matty palpation)

low grade fever (no chill),night sweat,weight loss,cough with hemoptysis,other signs depending on the organ involved (ie. pneumonia-like symptoms if the lungs are involved) also:scrofula

Auramin-Rhodamine stain

tuberculin test

Mycobacterium kansasii

Mycobacterium marinum

atypical mycobacteria

non-pathogenic guinea pigs

photochromogens (yellow-orange pigments when exposed to light)

T:soil,water

T:water (fresh/salt), swimming pool, aquarium,

PF:scuba divers,skin abrasion

lung disease

swimming-pool granuloma (fish-tank granuloma): -granulomatous, ulcerating lesion in the skin

Mycobacterium scrofulaceum



scototochromogens (pigments in dark)

T:Oropharynx

infection of draining lymph nodes

scrofula: -granulomatous cervical lymphadenitis -usually in children


Mycobacteriumavium

Mycobacteriumintracellulare

MAI



nonchromogens (no pigments)

T:soil,water

PF:AIDS,cancer,immuno-compromized

chronic pulmonary diseases

MAI:the most common bacterial infection in AIDS patients

Mycobacteriumfortuitum

Mycobacteriumchelonei



rapid growth

T:soil,water

PF:immune- compromised,prosthetic heart valves and joints

rarely occurring infection:skin, soft tissue infections

Mycobacteriumleprae

acid-fast

rod

obligate intracellular

slow growth

optimal growth at cool temperature (30˚C)

R:human mucosal membrane,skin,superficial nerves

T:nasal discharge from untreated leprosy patients

leprosy:

tuberculoid:-fewer lesions-macular (flat)-nerve enlargement (claw hand)

lepromatous:-numerous lesions-nodular-loss of eyebrows-destruction of nasal sputum-paraesthesia (abnormal sensation)-leonine facies (ridges & furrows)

+ lepromine test

- lepromine test

Pseudomonasaeruginosa

G –

rod

aerobic

oxidase +

nonfermente

R:water

T:water aerosols,raw vegetables,flowers

PF:

LPS:exotoxin A: -tissue necrosis (especially liver) -inhibits protein synthesis by ADP-ribosylation of EF-2 (elongation factor)

in normal people:loose stool,folliculitis,eye ulcers

burnt patients:skin infections,ecthyma gangrenosum (black necrotic centre,

MacConkey’s/ EMB agar


r

pyocyanin -blue colour in pus

pyoverdin (fluorescein) -yellow-green colour

odour:grape-like/corn nacho

nosocomial,extensive burns,chronic respiratory disease (cystic fibrosis),catheterized,immunosuppresed,anesthesia injections/CSF sampling, swimmers,gym goers,contact lenses

-this toxin is also present in C. diphtheria

pyocyanin:-damages cilia and mucosal cells of respiratory tract

elastase, protease: -help in invasion -histotoxic

erythematous-red-margin),eschar,cellulitis (blue-green pus),septicemia (also in AIDS pt’s)

in catheterized patients:UTI

in cystic fibrosis patients:recurrent pneumonias,septicemia

after CSF sampling/ anesthesia injection: meningitis

swimmers:otitis externa (most common casue),neck down (hot tub) follicles

gym shoes:osteochondritis

contact lens users:corneal infections

sepsis caused by P. aeruginosa has >50% mortality rate

Campylobacterjejuni

G –

rod (curved: comma/S shaped)

polar flagella

microaero-cephalic

grows well at 40˚C

motile

oxidase +

R:cattle, sheep, cat, dog,intestinal tract of humans

T:fecal-oral route

PF:improperly cooked chicken,raw eggs,poultry products,meat,milk

TX:enterotoxin: -destruction of mucosal surfaces of colon → blood and pus in stool

inflammatory diarrhea: >10 stools/day -bloody -abdominal pain -malaise -fever-lasts 3-5 days

most common cause of inflammatory diarrhea,2nd most common is salmonella

predisposes to Guillain-Barré syndrome: -autoimmune disease -demyelination

blood agar


urease -Helicobacterpylori

G –

rod (curved)

polar flagella

microaero-cephalic

grows well at 37˚C

oxidase +

urease +

R:human stomach

T:fecal-oral route,oral-oral (communicable),clustered families

attachment to mucosa→ urease → ammonia formation + inflammation →damage to mucosa ↓this damage predisposes to peptic ulcer and gastritis

ammonia helps bacterium survive by neutralizing acid

ammonia breath

gastritis,peptic ulcers,severe upper abdominal pain

helicobacter infection: predisposing factor for gastric cancer

blood agar

Legionellapneumophila

G – (weakly)

rod (pleomorphic)

R:water: -air conditioners -water coolers -rivers -streams

PF:Renal transplantAlcoholicCancerOld ageSmokerAIDS

T:aerosol from contaminated A/C

non-communicable

LPS Legionnaire’s disease(atypical pneumonia) with: -confusion -non-bloody diarrhea -proteinuria -hematuria -cough -resolves in 7-10 days

hyponatremia (↓Na)

Pontiac fever: -flu (fever, soar throat) -no pneumonia

charcoal-yeast agar

iron & cystein required

Bordetella pertussis

G –

rod

encapsulated

R:humans -10 years after vaccination, humans serve as reservoirs

hemagglutinin (FHA)

TX:pertussin(adenylate

pertussis (whooping cough):

catarrhal stage (1-2 weeks)

paroxysmal stage (2-4 weeks)

Bordet-Gengou medium



cyclase),

tracheal cytotoxin

98

E. coli: ADP ribosylation is by Gs protein

Gi protein in B. pertussis

convalescence (>3 weeks)

Francisella tularensis

G –

rod (pleomorphic)

facultative intracellular

R:wild animals:rabbits,deer,rodents

T:tick bite,aerosols (rabbit-skinning),ingestion (contaminated water, infected meat)

non-communicable

tularemia (endemic in the US):

tick bite:ulceroglandular type: -fever -ulcer at bite site -regional lymph node enlargement

skinning rabbits:pneumonia

ingestion:typhoidal tularemia

Brucella

melitensis(goats)

abortus(cattle)

suis(pig)

G –

rod

zoonotic

R:goats,sheep,cattle,pigs

T:unpasteurized dairy products (goat milk),direct contact to animals,slaughterhouse workers

localization in reiculoendothelial system -lymph nodes -liver -spleen -bone marrow

brucellosis (undulant fever): acute (cepticemia):

chronic (in older people):

102

Escherichia coli

G –

rod (motile)

NF:colon,vagina,urethra

TX:K polysaccharide (capsule),O antigen (cell

UTI:the most common cause of UTI is E. coli, S. saprophyticus is 2nd

blood agar

EMB (green)


facultative anaerobe

lactose fermenter

glucose fermenter

oxidase –

nitrates to nitrites reduction

PF (UTI):strinctures, stones, abnormal urine flow,indwelling urinary catheters

PF (watery diarrhea):poor sanitization of water,fruits/ vegetables contaminated with human feces

PF (bloody diarrhea):undercooked hamburgers,raw milk,fallen apples (apple juice)

wall) -serologic typing,H antigen (flagella)

TX:heat labile toxin,heat stable toxinE. coli: ADP ribosylation is by Gs protein,Gi protein in B. pertussis

verotoxin:

104

neonatal sepsis & meningitis:2nd most common cause after S. agalactiae

Enterotoxigenic (ETEC): -traveler’s diarrhea (watery) -diarrhea in <3 years old

Enteropathogenic (EPEC): -2nd most common cause of infantile diarrhea after rotavirus

Enteroinvasive (EIEC): -actin (Jet trails) -bloody/ watery diarrhea

Enterohemorrhagic (EHEC): -bloody diarrhea -hemolytic uremic syndrome -hemorrhagic colitis -no fever (present in shigellosis)

Enteroaggressive (EaggEC): -persistent diarrhea -vomiting

105

MacConkey’s agar (pink)

Shigella

disenteriae(severe)

sonnei(common)

G –

rod


glucose fermenter

oxidase –


R:human colon(no animals)

T:fecal-oral route

fingersfoodfecesflies

communicable-low quantity needed to cause an infection

TX:O antigen (cell wall) -serologic typing

invasion of the cells of distal ileum and colon

dysentery: -fever (>101˚F) -lower abdominal pain -tenesmus (spasms of urogenital region) -first watery, then bloody diarrhea -shallow ulcers

shigellosis:-the most severe form of diarrhea (10-15 episodes/day)

blood agar

EMB/ MacConkey’s agar -colourless colonies

Klebsiella G – R: TX: pneumonia: blood agar


rod

large capsule


lactose fermenter

glucose fermenter

oxidase –


human colon,upper respiratory tract

T:from own flora in low immunity,respiratory droplets,catheters (nosocomial)

PF:diabetes,alcoholism,old age,chronic respiratory disease

K polysaccharide (capsule) -antiphagocytic

O antigen (cell wall) -serologic typing

LPS: -fever -inflammation -shock

-abscess -thick, bloody, jelly-like sputum

UTI: -nosocomial (catheters)

septicemia: -in immunocompromized

EMB/ MacConkey’s agar -pink colonies

Salmonella

typhi

enteritidistyphimuriumcholeraesuis

G –

rod (motile)


produce H2S

glucose fermenter

oxidase –


R:humans (no animals)

T:fecal-oral route from human carriers (gall bladder)

PF:↓ stomach acid

R:enteric tracts of humans, chickens, turtles

T:raw chicken, egg

PF:sickle cell anemia

PF:

TX:K polysaccharide (capsule)

O antigen (cell wall) -serologic typing

H antigen (flagella)

Vi antigen (typoid)

-invasion of epithelium of SI & LI(enteric fever)

typhoid fever/ enteric fever ( S . typhi/ S. paratyphi): -rose spots -constipation -gallbladder inflammation -Vi antigen:multiplication in Payer’s patches→ spread to phagocytes of liver, gall bladder, & spleen → leading to bacteremia-constipation followed by diarrhea

enterocolitis /gastroenteritis(6-8 hours): -inflammation -loose bloody stool -2nd most common cause of inflammatory diarrhea, after Campylobacter

septicemia: -in very young/ elderly

blood agar

EMB/ MacConkey’s agar -colourless colonies

widal test


sickle cell anemia

PF:aortic aneurysms, infarcts

osteomyelitis/ arthritis: -followed by pneumonia, meningitis -the most common cause of osteomyelitis in patients with sickle cell disease

metastatic abscess: -abscess away from primary origin

Aerobes: Negging Pests Must Breath

Nocardia

Pseudomonas aeruginosa

Mycobacterium TB

Bacillus

Anaerobes: A - B – C

Actinomyces

Bacteroides

Clostridium

Capsulated: Some Bacteria Have An Effective Paste Surrounding Membrane Yielding Pseudo Fort, Bypassing Killing

Strep. pneumonia

Bordetella, Bacteroides

H. influenza

Anthracis (Bacillus)

E. coli


Pasteurella

Salmonella

Meningitidis (Neisseria)

Yersinia

Pseudomonas

Francisella

Brucella

Klebsiella

Pneumonia (most common causes):

Type OrganismMost common (bloody-rusty sputum) S. pneumonia Thick, bloody, jelly-like sputum KlebsiellaIn alcoholics S. pneumoniaIn cystic fibrosis patients (recurrent) Pseudomonas aeruginosaAtypical pneumonia (Legionnaire’s disease) Legionella pneumophiliaAfter rabbit-skinning Francisella tularensisSequel to osteomyelitis non-typhoid SalmonellaPyogenic infection S. aureus

Meningitis (most common causes):

Type OrganismNeonatal S. agalactiae

E. coliAdult S. pneumoniaeBetween ages 2 & 18 Neisseria meningitidisIn renal transplant & cancer patients Listeria monocytogenesAfter CSF sampling/ anesthesia injection Pseudomonas aeruginosaSequel to osteomyelitis non-typhoid Salmonella

Gastroenteritis:

Transmission Vomiting Diarrhea OrganismMost Common:custard pastries, potato salad

more than diarrhea

watery S. aureus


after 1-8 hours2nd Most Common:reheated fried rice/ Chinese restaurant

after 1-6 hours wateryafter 18 hours

B. cereus

Most Common Nosocomial bloody/ non-bloody Clostridium difficileUnpasteurized, contaminated dairy products, undercooked meats

little watery Listeria monocytogenes

Most Common Inflammatory:cattle, sheep, dogsorimproperly cooked chicken, raw eggs, poultry products, meat, milk

bloody Campylobacter jejuni

2nd Most Common Inflammatory:from humansorraw chicken, egg

bloodyafter 6-8 hours

Salmonella

A/C, water cooler contaminationwith atypical pneumonia

non-bloody Legionella pneumophila

Traveler’s Diarrhea:poor sanitization of water, contaminated fruits & vegetables

watery E. coli (Enterotoxigenic)

2nd Most Common cause of Infantile diarrhea after rotavirus

watery E. coli (Enteropathogenic)

watery/ bloody E. coli (Enteroinvasive)

Undercooked hamburgers/ fallen apples (juice)

bloody E. coli (Enterohemorrhagic)

vomiting persistent E. coli (Enteroaggressive)

Most Severe Formwith fever & tenesmus (dysentery)

first watery, then bloody

Shigella

microbio summary

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