51121813 All Bacteria

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ALL BACTERIA

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BACTERIA CHARACTERISTICS DISEASE RESERVOIR / TRANSMISSION VIRULENCE / PATHOGENESIS CLINICAL DIAGNOSIS TREATMENT

R E S P IR A T O R Y

normal flora β-lactamase

diphtheria humans only tuberculosis normal flora asymptomatic carriers Moraxella Catarrhalis gram (-) aerobic diplococcus. Oxidase (+) otitis media, sinusitis in children respiratory

droplets bronchitis or pneumonia in pts with underlying chronic lung disease mostly skipped, blood or chocolate agar

penicillin + β lactamase inhibitor (amoxicillin-clavulanic acid), 2nd, 3rd gen cephalosporin, TMP-SMX, macrolide Streptococcal pyogenes (group A antigen) gram (+)coccus in chains or pairs. catalase (-), lactose (+) Strep throat → rheumatic fever, acute post-streptococcal glomerulonephritis normal flora, infected persons respiratory droplets

LTA, surface proteins F and M, hyaluronic acid capsule, streptolysin,

exo-enzymes, pyrogenic exotoxins

acute inflammation of pharynx and tonsils, sore throat, fever, exudative tonsillitis, anterior cervical lymphadenopathy, scarlatiniform rash

or fever β-hemolysis on blood agar, bacitracin sensitive treat to prevent acute rheumatic fever: penicillin Corynebacterium diphtheriae gram (+) club-shaped rods, aerobe normal flora,

humans only respiratory droplets

Heat-labile A-B exotoxin, ADP ribosyl transferase (blocks protein syn), diphtheria toxin is invasive exotoxin → cell death, necrosis

pseudomembrane → obstruction and suffocation, sore throat and pharyngitis, low grade fever, regional lymph nodes swollen - bull neck. Toxin: myocarditis & cardiac dysfunction, laryngeal nerve palsy, lower limb

polyneuritis

Loeffler medium, selective tellurite medium (- extra flora)

--> black colonies with dark halo. Toxin

detection: Eleck immunodiffusion test antitoxin serum therapy + antibiotics (penicillin or macrolides: erythromycin) DTaP vaccine Bordetella pertussis gram (-) cocco-bacillus, strict aerobe, mucosal surface pathogen whooping cough -

pertussis respiratory droplets

attachment, immobilization, destruction (murein) of cilia, Fha, Ptx (AB toxin - ↑ cAMP), pertactin,

pili

Catarrhal stage: 1-2 wk, highly communicable, paroxysmal stage: 2-4 wk,

paroxysmal cough, whoop. Convalescent stage: wks to mn charcoal-blood agar (Bordet-gengou potato agar) , pearl-like colonies, direct fluorescence antibody test erythromycin DTaP vaccine Mycobacterium tuberculosis ACID-FAST, rod shaped, obligate aerobe, very slow growth, facultative intracellular reservoir - infected humans Inhalation of infectious aerosols

Mycolic acid, sulfolipids, cord factor, tuberculin + mycolic acid - DAMAGE DONE BY HOST IMMUNE

SYSTEM

primary TB: Ghon complex, progressive primary (active) TB, latent dormant TB, secondary (reactivation) TB: apex. Productive cough - bloody sputum, fever,

weight low, night sweats

CXR, PPD: >5mm = (+) in HIV, >10mm = (+) in high-risk. >15mm = (+) in low-risk, ziehl-Neelson stain, Lowenstein-Jensen medium isoniazid, rifampin (4m), pyrazinamide (2m), ethambutol BCG Vaccine, isoniazid prophylaxis Haemophilus influenzae (non-encapsulated) gram (-) pleomorphic rod, small, facultative anaerobe. requires growth factor X (hemin) and V (NAD, NADP) otitis media, sinusitis, bronchitis

lipopolysaccharides, IgA protease, polysaccharide capsule

infants: passive maternal protection, poor response first 2 years, > 5 - disease

uncommon

chocolate agar (X and V factors), satellite phenomenon, latex agglutination test - PRP amoxicillin + clavulanic acid Haemophilus influenzae (Hib) epiglottitis, pneumonia, meningitis, septic arthritis, cellulitis 3rd gen cephalosporin Hib conjugate vaccine Streptococcus pneumoniae (pneumococcus) lancet-shaped, gram (+) diplococcus or in chains, fermentation metabolism community-acquired pneumonia, OM, adult meningitis normal flora,

humans only respiratory droplets

polysaccharide capsule, autolysin, pneumolysin O, peptidoglycan/ teichoic acids, adhesins, GOOD AT

PICKING UP DNA

rusty sputum, typical lobar pneumonia

α-hemolytic on blood agar, not typeable

(A/B), Optochin-sensitive, bile soluble,

surface capsule OM: amoxicillin + clavulanic acid. Pneumonia/meningiti s: 3rd gen cephalosporin + vancomycin PPV, PCV7 vaccine Mycoplasma pneumoniae smallest free-living bacteria, NO CELL WALL, pleomorphic, no gram stain "walking pneumonia", tracheobronchitis human respiratory tract aerosol droplets

p1 adhesin, toxic metabolic products: hydrogen peroxide and

superoxide radicals

hacking cough, dry → productive, slow resolution Eaton's media (sterols), serological tests tetracycline or macrolide Chlamydophila species small obligate INTRACELLULAR pathogen, gram (-),

not seen on gram stain, cell wall lacks peptidoglycan layer, unable ot make ATP -

energy parasites

pneumonia or

bronchitis humans infected respiratory droplets 2 stages: elementary body (EB): infectious, survive outside, non reproductive. Reticulate body (RB):

noninfectious, intracytoplasmic, reproductive form

asymptomatic to pneumonia or bronchitis, complications: atherosclerotic vascular

diseases serological tests, isolation is difficult macrolides (azithromycin) or tetracyclines (doxycycline) Chlamydophila psittaci parrot fever, psittacosis, ornithosis, pneumonia zoonotic pathogen, mainly birds inhalation of dried secretions from birds serodiagnosis by complement fixation test tetracycline or erythromycin

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R E S P IR A T O R Y R E S P IR A T O R Y mucoid colonies

unknown resembles TB - abscesses and granulomas

pneumonia, wound infections, UTI, sepsis case-by-case

Bacillus anthracis anthrax ubiquitous, zoonotic

U R IN A R Y T R A C T IN F E C T IO N S

Escherichia coli motile, lactose (+) normal flora

catheters capsule, pili, endotoxin

Proteus mirabilis normal flora MacConkey agar: clear

Enterobacter lactose (+), motile adhesins, capsule, endotoxin

lactose (+) adhesins, capsule, endotoxin brick-red colonies

U R IN A R Y T R A C T IN F E C T IO N

S endogenous adhesin, inflammation response

normal flora

adhesins, toxins, enzymes Legionella pneumophila weakly gram (-) rods, water organisms (45C), complex nutritional requirements, aerobic, motile pneumonia, Legionnaire's disease and Pontiac fever biofilms in water sources inhalation of contaminated aerosols, no person-to-person transmissions

low virulence, biofilms, prevents

phagosome-lysosome fusion, lung

damage and inflammatory response

fever, chills, non-productive cough, chest pain, HA, mental confusion, diarrhea

BYCE (buffered charcoal yeast extract), requires L-cys, Fe, pH 6-9, slow

growth 2-5 days, SILVER STAIN

macrolides (erythromycin), Pontiac fever -

self-limiting Klebsiella

pneumoniae

enterobacteriaceae family, gram(-) rod,

lactose (+)

pneumonia, UTI,

septicemia human colon and URT, from own flora

capsule, endotoxin - necrotic destruction of alveolar spaces, abscesses, resistance plasmids

hacking cough, dry → productive, slow

resolution. DM at high risk cephalosporins3rd gen

Pseudomonas aeruginosa gram(-) rod, aerobic, motile, minimal nutritional requirements opportunistic

pathogen ubiquitous in environment

respiratory secretions, direct contact,

fomites

pili, capsule, endotoxin: lipopolysaccharide, tissue damage:

exotoxin A (AB - ↓ protein syn), exoenzyme S, elastase, alkaline protease, cytotoxin, hemolysin

fever, productive cough, weight loss, breathing difficulties and cyanosis, complications: malignant otitis externa (DM), colonization

of cystic fibrosis patients

blue-green colonies, pyocyanin,

polyverdin, or fluorescein (green), fruity aroma, mucoid,

UV light antipseudomonal PNC (carbenicillin) + aminoglycoside (tobramycin) Burkholderia pseudomallei gram (-), aerobic rod melioidosis, acute pneumonia soil, ponds, rice paddies, zoonotic inhalation, inoculation β-lactams or tetracyclines, high mortality if untreated Burkholderia cepacia opportunistic pathogen - same as P. aeruginosa, causes serious infections Acinetobacter spp gram (-) coccobacilli nosocomial infections in immunodeficient pt

soil, water, sewage, animals, normal skin, GI tract of pts or

health care workers aerobic gram (+),

spore forming, nonmotile

polypeptide capsule, spore, exotoxin: EF, LF, PA (adenyl

cyclase)

dermal, respiratory, GI anthrax, possible

sepsis nonhemolytic coloniesbox car chains, large

fluoroquinolones (ciprofloxacin) cell-free vaccine - used

in high-risk E n te ro b a c te ri a c e ae g ra m ( -) r o d s , f a cu lta tiv e a n a e ro b e s, ca ta la se ( + ), o xi d a se ( -) , n itr ite ( + ) UTI, diarrheas/ dysentery, Neonatal meningitis, septicemia

FimH (cystitis) - FIMBRIAL ANTIGEN, P-pilus (nephritis), capsule, hemolysin, aerobactin, LPS

acute uncomplicated UTI, acute uncomplicated pyelonephritis, complicated UTIs, asymptomatic bacteriuria, renal abscess

MacConkey agar: lactose (+) - pink, EMB

agar - LACTOSE (+): blue-black colonies TMP/SMX - UTIs in hospital and community, Fluoroquinolone - complicated UTI, Cephalosporin - pregnancy Klebsiella

pneumoniae non-motile, lactose (+)

UTIs, Lower respiratory tract infection (lobar pneumonia) MacConkey agar, mucoid highly motile, lactose (-), urease (+) community/hospita l UTIs, pneumonia, septicemia, wound infections

peritrichous flagella - swarming, adhesins, endotoxin common cause

of nosocomial infections

normal flora and environment Serratia

(marcescens)

nosocomial infections

normal flora and environment Staphylococcus Saprophyticus gram (+) cocci, clusters, catalase (+), coagulase (-) UTIs sexually active young women γ-hemolysis, novobiocin resistant Enterococcus faecalis (80%) gram (+) diplococci or short chains, catalase (-), Lancefield's group D antigen nosocomial infections, UTI, endocarditis (pt with damaged heart valves), wound infections, bacteremia γ or α hemolytic, resistant to 40% bile salts, 6.5% to NaCl, bacitracin and Optochin.

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U R IN A R Y T R A C T IN F E C T IO N S normal flora

adhesins, toxins, enzymes

ubiquitous in environment C A R D IO V A S C U L A R IN F E C T IO N S normal flora

normal flora biofilm vancomycin

normal flora, dental caries

normal intestinal flora

normal intestinal flora associated with colon cancer

ubiquitous in environment C A R D IO V A S C U L A R IN F E C T IO N S

subacute IE (5%), complications may include massive arterial emboli and congestive heart failure gram (+) diplococci or short chains, catalase (-), Lancefield's group D antigen nosocomial infections, UTI, endocarditis (pt with damaged heart valves), wound infections, bacteremia

acute uncomplicated UTI, acute uncomplicated pyelonephritis, complicated UTIs, asymptomatic bacteriuria, renal abscess

γ or α hemolytic, resistant to 40% bile salts, 6.5% to NaCl, bacitracin and Optochin. TMP/SMX - UTIs in hospital and community, Fluoroquinolone - complicated UTI, Cephalosporin - pregnancy Enterococcus faecium (20%) Pseudomonas aeruginosa aerobic gram (-) rod, motile, oxidase (+), lactose (-) opportunistic infections

polysaccharide capsule, endotoxin, adhesin, exotoxins

UV light CARDIOVASCUL AR INFECTIONS Staphylococcus aureus gram (+) cocci, clusters, catalase (+), coagulase (+), salt tolerant, mannitol (+) infective endocarditis, etc… Protein A - (-) phagocytosis. Fibrinogen-binding protein - clumping factor. Coagulase - fibrin clot. Cytotoxic toxins - pore-forming

toxins. Enterotoxins A-E: gastroenteritis, TSST-1, Exfoliations -

skin infections

complications: embolization from infective endocarditis to parietal lobe, to lung

M u lti p le ( + ) b lo o d c u ltu re s (3 -5 s et s ta ke n) , i f (+ ) fo r sa m e o rg a n is m s e ns iti vi ty t e st in g. C u ltu re ( -) : re ce n t a n tib io tic u se , fa st id io u s o rg a n is m s, f un g i. E ch oc a rd io g ra ph y - ve g e ta tio ns mannitol-salt agar: yellow colonies, β-hemolysis N a ti v e v a lv e I E : P N C + g e n ta m yc in . I V d ru g u s e : n a fc ill in + g e n ta m ic in . P ro s th e ti c v a lv e I E : va n co m yc in + g e n ta m ic in methicillin resistant, some vancomycin emerging Staphylococcus epidermidis gram (+) cocci, clusters, catalase (+), coagulase (-) catheter and prosthetic device infections, IE in IV drug users and prosthetic valve IE

Subacute IE: w/n 2 weeks of dental or other procedure, low grade fever and chills, fatigue,

anorexia weight loss, new or changing heart murmurs, skin lesions. Acute IE: acute onset of high-grade fever and chills, rapid onset of

CHF, murmurs can be absent

no hemolysis, NOVOBIOCIN sensitive Viridans Streptococci (many, do not need to identify) gram (+) cocci, chains, catalase (-), lack capsule and

lancefield antigens, no serologic group most common cause of subacute IE in pts with abnormal or damaged heart valves

low virulence, dextran-mediated adherence - biofilm → damaged heart valve surfaces, FimA surface

adhesin, lack capsule

α-hemolytic, Optochin resistant, not bile

soluble Enterococcus faecalis (was classified as streptococcus) gram (+) cocci, single cells, diplococci or short chains, catalase (-), lancefield antigen: group D nosocomial infections, UTIs, wound infections, bacteremia, endocarditis in pts with damaged heart valves

not bile soluble, growth in 6.5% NaCl, α or γ-hemolysis major resistant problems for antibiotic problems Streptococcus Bovis gram (+) cocci, chain, catalase (-), lancefield antigen: group D, also named non enterococcal group D organisms subacute infective endocarditis

not bile soluble, no growth in 6.5% NaCl, α or γ-hemolysis sensitive to penicillin Pseudomonas aeruginosa aerobic gram (-) motile rod, oxidase

(+)

IE in IV drug users and patients with

prosthetic heart valves. no fermentation, produces pigments - BLUE-GREEN O T H E R G R A M ( -) O R G A N IS M S : H A C E K Haemophilus _aphrophilus

fastidious organisms; requires 5-10% carbon dioxide for growth + 3 wks

incubation Actinobacillus actinomycetemco mitans Cardiobacterium hominis

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C A R D IO V A S C U L A R IN F E C T IO N S

subacute IE (5%), complications may include massive arterial emboli and congestive heart failure

Kingella kingae

B. quintana most commonly involved homeless males with poor hygiene, must be considered in cases of culture-negative endocarditis among individuals whoa re homeless Polymicrobial IE observed in cases of IV drug users IE, the cardiac surgery mortality rate is twice that associated with single-agent IE.

S K IN IN F E C T IO N S

β-hemolysis penicillin, macrolide

ubiquitous

acid fast bacillus Leprosy reservoir: humans

Bacillus anthracis anthrax

W O U N D IN F E C T IO N S A N A E R O B IC G R A M ( + )

ubiquitous in soil, flora

actinomycosis low O T H E R G R A M ( -) O R G A N IS M S : H A C E K

fastidious organisms; requires 5-10% carbon dioxide for growth + 3 wks

incubation N a ti v e v a lv e I E : P N C + g e n ta m yc in . IV d ru g u s e: n a fc ill in + g e n ta m ic in . P ro s th e ti c v a lv e I E : va n co m yc in + g e n ta m ic in Eikenella corrodens Bartonella species

most common combo: Pseudomonas + enterococci

Fungal

endocarditis_SKIN Generally found in IV drug users and intensive care unit patients who receive broad spectrum antibiotics, blood cultures often negative, causes subacute IE. Most common organisms of both fungal valve IE and fungal prosthetic valve IE are: Candida spp, and Aspergillus spp. INFECTIONS Staphylococcus aureus gram (+) cocci, clusters, catalase (+), coagulase (+), salt tolerant, mannitol (+) folliculitis, furuncles, carbuncles, impetigo, scalded skin syndrome, toxi shock syndrome human skin

and mucosa person-to-person

fibronectin-binding proteins, collagen binding proteins, clumping factors (A, B), teichoic acids, capsule, protein A - binds Fc, prevents complement,

enzymes, exotoxins, inflammatory response, superantigen: TSST-1, enterotoxins, ETA, ETB, exfolatins

produce bullae

Furuncles, carbuncles - neck, face, axillae, buttocks. NTSS associated with tampons, scalded skin syndrome in neonates, bullous

impetigo is localized form.

β-hemolysis, mannitol salt agar, 7.5% NaCl

MSSA: nafcillin, MRSA: vancomycin, VRSA: linezolid, Synercid, daptomycin Streptococcus pyogenes gram (+), chain forming cocci and

diplococci impetigo, erysipelas, cellulitis, necrotoxic fasciitis - gangrene, scarlet fever normal flora, infected persons respiratory droplets

M-protein, F-protein and lipoteichoic acid, hyaluronic acid capsule, streptococcal pyrogenic exotoxins, superantigens, streptolysin S + O, exoenzymes, peptidoglycan + teichoic

acids

HONEY CRUSTED LESIONS - involves dermal lymphatics, pain and systemic manifestation, necrotizing fascitis "flesh-eating bacteria", scarlet fever: strawberry

tongue, diffuse erythematous rash, TSS

Pseudomonas aeruginosa

aerobic gram (-) motile rod, oxidase

(+)

"Hot tub: folliculitis, burn

wounds

capsule, biofilm, lipopolysaccharide and lipid A, A-B toxin, exoenzymes,

pili

blue-green pus, grape-like odor, inflamed follicles from neck down, shallow puncture

wound through tennis shoe sole

UV light antipseudomonal penicillin (carbenicillin) + aminoglycoside (tobramycin) Mycobacterium Leprae

obligate intracellular parasite of macrophages and Schwann cells. DAMAGE FROM HOST RESPONSE

Paucibacillary (tuberculoid) leprosy: central healing, low infectivity, few rods, DTH to lepromin. Multibacillary (lepromatous) leprosy: infectious, many rods, (-) lepromin

no growth on medium or tissue culture paucibacillary/tuberc uloid: Dapsone + rifampin ~6 months. Multibacillary/leprom atous: Dapsone + rifampin + clofazimine ~2 years

gram (+) rod, spore ubiquitous, zoonotic, lives in soil, causes anthrax in animals and humans

vegetative form, dormant spore,

polypeptide capsule, PA, EF, LF cutaneous anthrax: erythematous papule, black eschar surrounded by edema

"box car chains" culture: large colonies;

NON-HEMOLYTIC,

M'Fadyean methylene blue stain or DFA

fluoroquinolones (ciprofloxacin) WOUND INFECTIONS Clostridium perfringens large gram (+) rods, spore, strict anaerobes, lactose

(+) only

myonecrosis "GAS GANGRENE",

cellulitis

necrotizing and hemolytic toxins: LECITHINASE ~ PHOSPHOLIPASE

C ~ ALPHA TOXIN - splits phospholipid molecles., enterotoxins, DNase, hyaluronidase

marked gas formation, "crepitance in tissue", systemic signs: fever, hemolysis, hypotension,

renal failure, shock, death

culture under anaerobic conditions,

Iron Milk Medium @ 45ºC → stormy fermentation, blood agar - characteristic double zone of hemolysis surgery, amputation, penicillin, hyperbaric O2 chamber Actinomyces (israelii) gram (+) rods, facultative or strict anaerobes

part of oral, intestinal and vaginal human flora

granulomatous lesions, suppurative, abscesses, sulfur granules: YELLOW PUS,

dental extraction or trauma

anaerobic conditions, sulfur granules. long branching filaments, slow growth ~2 weeks,

white colonies: molar tooth appearance

surgical drainage, penicillin or

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W O U N D IN F E C T IO N S A N A E R O B IC G R A M ( + ) endogenous

animal bites systemic infection in immunocompromised pts

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Vibrio vulnificus necrotic cellulitis found in salt water, oysters polar flagella, polysaccharide capsule

S Y S T E M IC IN F E C T IO N S

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Rickettsialpox

Rats Rat flea

Scrub typhus

Pepto-streptococcus gram (+) cocci, anaerobic

infection at normally sterile

sites

part of normal human flora; oral, GI, GU, skin

brain abscesses, sinusitis, endocarditis, osteomyelitis, intraabdominal infections, pelvic

infections, skin and soft tissue infections

anaerobic conditions, gram (+) in pairs or chains, rich media for

culture, long incubation time 5-7 days penicillin + broad spectrum A N A E R O B IC G R A M ( -) Bacteroides fragilis, Fusobacterium nucleatum, Prevotella melaninogenica pleomorphic anaerobic gram (-) rods

mixed, skin and soft-tissue infections

normal

human flora capsule, fimbriae, succinic acid, extracellular enzymes

illness when native host defenses and anatomical barriers are altered, progress to

myonecrosis

anaerobic culture, foul

odor metronidazole, surgery

Pasteurella multocida gram (-) coccobacilli, small, facultative anaerobes localized cellulitis

and lymphadenitis animals flora of lactam inhibitoramoxicillin +

β-Bartonella

henselae short, aerobesgram (-) rods, cat-scratch disease reservoir: animals

cat scratches, bites, contact

with fleas

cutaneous papules or pustules at inoculation site → painful regional lymphadenopathy,

Bacillary angiomatosis in IC - pts

rods in lymph nodes, culture usually negative, definitive dx by serologic tests antibiotics not indicated gram (-) rods, curved, facultative anaerobe, oxidase (+)

wound infections after exposure to contaminated seawater - necrotic cellulitis,

gastroenteritis and septicemia after consumption of raw oysters

culture: requires salt for growth media: Thiosulfate citrate bile salts sucrose agar (TCBS), ID - biochemical tests tetracycline (doxycycline) SYSTEMIC INFECTIONS Rickettsia rickettsii (Spotted fever group)

small gram(-) rods; take gram staining

weakly; obligate INTRACELLULAR pathogens; zoonotic pathogens Rocky mountain spotted fever (April → Sept) Wild rodents, domestic animals (dogs), ticks Tick (Dermacentor), American dog tick (eastern US), Rocky Mt wood tick (western US) Infect vascular endothelial cells → (1) induced endocytosis (2) lysis of phagosome membrane - phospholipase A (3) replication in host cell cytoplasm (4) lysis of host cell → vascular damage (hemorrhage, edema), LPS - weak endotoxin activity, vasculitis and thrombosis (around all the

body). IMMUNITY: both humoral and cell

mediated important - after recovery - solid and lasting immunity Mortality: 5-7% delayed therapy to 2nd week, ~25% if untreated.

5-10 days incubation. EARLY: Flu-like symptoms; LATER: petechial-hemorrhagic rash (first on extremities → spread to entire body); various organs failures (2nd & 3rd febrile day). Fever + Rash + Previous tick

bite

Clinical presentation + Serologic tests (indirect immuno-fluorescence assay) (high Ig titers by the 7th day of illness); PCR

(most rapid and specific); Immuno-staining (70%) Tetracycline (doxycycline) Rickettsia akari (Spotted fever group) Wild rodents,

rodent mites (transovarian)Mouse mite benign, self-limited disease, not fatal

Phase1: (~1 wk) local proliferation → eschar at bite site; Phase2: (~3-7d) dissemination → flu-like symptoms + fever + generalized rash (randomly distributed, papulovesicular →

eschar, exanthem ~ chicken pox)

Clinical presentation + Serologic tests, typhus (indirect fluorescent antibody test, latex agglutination tests). NO STAIN - INTRACELLULAR Tetracycline (doxycycline) + chloramphenicol can speed recovery (benign) Rickettsia prowazekii (Typhus group) Epidemic typhus, Brill-Zinsser disease (Recrudescent typhus) Humans; flying squirrels Human body louse

exit: cell lysis Mortality: 10-60%

if untreated

(~8d) Flu-like symptoms; maculopapular rash (first on trunk → spread to extremities);

complications: myocarditis, CNS dysfunction; Recrudescent typhus = (10-40 yrs later) endogenous secondary infection by

R. prowazekii persisting in reticuloendothelial cells

Tetracycline (doxycycline) or chloramphenicol, vaccine for high-risk

pop Rickettsia typhi

(Typhus group) Endemic typhus (Murine typhus)

mortality rate - rare even with

untreated

(1-2 wk) Same as Epidemic typhus but milder; rash not always present

Tetracycline (doxycycline) and chloramphenicol Orientia tsutsugamushi (Scrub typhus group) Rodents, rodent mites Mite larva (chigger) (transovarian) mortality ~30% in untreated

(1-3 wks) Necrotizing eschar at bite site; flu-like symptoms; maculopapular rash (first on trunk → spread to extremities) + generalized

lymphadenopathy

Tetracycline (doxycycline) or chloramphenicol

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S Y S T E M IC IN F E C T IO N S

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Deer, dogs Lone star tick

Ehrlichia ewingii Dogs, ticks Lone star tick

Coxiella burnetii S Y S T E M IC IN F E C T IO N S

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Yersinia pestis Streptomycin small gram(-) rods;

take gram staining weakly; obligate INTRACELLULAR pathogens; zoonotic pathogens Ehrlichia chaffeensis Human Monocytic

Ehrlichiosis Infect leukocytes → (1)

phagocytosis (2) Inhibition of phagosome-lysosome fusion + multiplication in cytoplasmic vacuoles - Morula (3) Host cell + phagosome lyses mononuclear leukocytes (monocytes,

macrophages) Similar to RMSF but generally without rash, 5-10 days, leukopenia, thrombocytopenia, elevated liver enzymes. Severe: prolonged fever, renal failure, disseminated intravascular

coagulopathy, meningoencephalitis, adult respiratory distress syndrome, seizures, coma.

Mortality ~2-3%

Clinical presentation + Microscopy: Giemsa

stain. (Morulae) + Serologic tests: IFA (high IgM or IgG titers

by the 2nd _{wk of} illness), PCR Tetracycline (doxycycline) Anaplasma phagocytophila Human Granulocytic Ehrlichiosis Sheep, cattle, rodents, bisons, deer… Black legged tick (Ixodes) granulocytes (neutrophils > eosinophils) (higher morality ~ 10%) same - pts with underlying immuno-suppression Small gram(-) pleomorphic rod; intracellular pathogen with extracellular "spore-like" form; zoonotic pathogen Q. fever; Chronic Q fever (Endocarditis) Sheep, goats, cattle (excreted in milk, urine, feces, amniotic fluids and placenta Inhalation of dust containing pathogen Infect macrophages=> (1) phagocytosis (2) phagosome-lysosome fusion; but bacteria survive and multiply inside acidic phagolysosome (3) Host cell + phagolysosome lyses resistant to heat and drying, Proliferation in respiratory tract then dissemination to other organs

Flu-like symptoms, rarely rash; pneumonia; hepatitis; endocarditis (Chronic form - 1-20

y, high mortality ~65%)

Serologic tests - antigenic variation =>

acute disease: high titer of phase II antigen; chronic disease: high titers of

phase I and II antigens; PCR Acute: tetracycline (doxycycline); Chronic: (doxycycline + quinolones for 4 yrs

or doxycycline + hydroxy-chloroquine 1.5 to 3 yrs), vaccine for high

risk pop Gram(-) rod, lactose (-), oxidase (-), catalase (+), coagulase (+), nonmotile, bipolar staining; facultative intracellular pathogen; zoonotic pathogen Plague: Bubonic, Pneumonic & Septicemic Wild rodents (Sylvanic cycle); Urban rats (Urban cycle) Flea bite; direct contact; respiratory droplets (only pneumonic plague)

Virulence plasmids; Changes in genes expression in response to environmental changes (1) Changes

in flea behavior: yersinia murine toxin (survival), low T - fibrinolysin &

phospholipase (agglutination); (2) Survival in human body: Capsule (F1

protein), plasminogen activator: prevents opsonization, important for dissemination (3) Damage: Type III secretion system (Yop proteins:

Lcr, Ysc) suppress cytokine production, cytotoxic effect; endotoxin (septic shock); yersiniabactin (obtain iron from

host); intracellular grow in reticuloendothelial cells

Bubonic plague: flu-like symptoms; Multiplication of bacteria in regional lymph node => suppurative lymphadenitis = "Bubo" (~70% M untreated); Pneumonic plague: flu-like symptoms + cough, bloody sputum, dyspnea and cyanosis (2-3rd day death due to septic shock); Septicemic plague: bacteremia

without buboes => flu-like symptoms+ bleeding into skin and other organs => dark

discoloration (40% M in treated, 100% in untreated)

Serologic tests: direct immunofluorescence test (rapid, presence of

F1); microscopy: gram stain or Giemsa - bipolar staining, culture: highly infectious Streptomycin, tetracycline, and chloramphenicol, isolation for 72 hours

Francisella tularensis

Small gram(-) rod,

aerobe, require cysteine, facultative intracellular pathogen; zoonotic pathogen, oxidase (-), urease (-), nonmotile, thin lipid

capsule

Tularemia (rabbit or deer fly fever)

Wild animals, ticks, deer

fly

Tick or fly bite, direct contact, inhalation, ingestion of contaminated food or water

Infects reticuloendothelial organs: multiplication in macrophages, hepatocytes and endothelial cells => necrosis and granuloma production in areas of multiplication; Survival: inhibition of phagosome-lysosome fusion; antiphagocytic lipid capsule

Ulceroglandular form: 75% painful ulcerating lesion at site of infection; Oculoglandular

form: 1% purulent conjunctivitis + lymphadenopathy; also Pneumonic, Gastrointestinal & Septicemic forms

(10-15%, more severe). Untreated ~5-30% M

Serologic tests; PCR, gram stain unsuccessful, requires

cysteine-glucose blood agar - tiny transparent colonies,

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S Y S T E M IC IN F E C T IO N S Brucellosis

Humans, lice Erythromycin

S

p

ir

o

c

h

e

te

s

in

fe

c

ti

o

n

s

Lyme disease Tick bite

Tick Tick bite

Leptospirosis G I I N F E C T IO N S W a te ry D ia rr h e a S m a ll in te s ti n e d is e a s e N o in v a s io n , n o in fl a m m a ti o n

Fecal-oral Watery diarrhea, abdominal cramps Immunoassays

F lu id + e le c tr o ly te r e p la c e m e n t Brucella spp. (abortus, melitensis, suis)

Small gram(-) rods, strict aerobes, facultative intracellular pathogens, zoonotic pathogens, no capsule, no spore Domestic livestock Direct contact, inhalation, ingestion of unpasteurized dairy products Multiply in macrophages in reticuloendothelial system => granulomas => septicemia Inhibit phagosome-lysosome fusion; impair cytokine production; endotoxin

Flu-like symptoms; night sweats (undulant fever); Chronic illness: body aches, headache,

anorexia, depression… few physical findings unless enlargement of reticuloendothelial

organs. (M is low <25)

Serologic tests, microscopy: insensitive, culture: difficult and hazardous.

B abortus - needs CO2, antigen A, (-) by dye thionine, B. Melitensis - antigen M, B. Suis - (-) by fuchsine Doxycycline + rifampin (for 6 weeks) Bartonella quintana

Small gram(-) rod;

aerobe, zoonotic pathogen Trench fever, bacillary angiomatosis, subacute endocarditis Contaminated louse feces (scratching)

Prolonged bacteremia, WWI, now amongst homeless, little is known, biopsy of skin does not reveal

organisms

4 fever patterns: (1) asymptomatic with 1 episode; (2) 3-5 days single febrile episode; (3) multiple recurrent febrile episodes "5-day fever"; (4) persistent fever for 2-6 weeks.

Serologic tests; PCR, fastidious growth requirements, difficult

culture, blood of chocolate agar, 5% CO2 with high humidity

for 4 weeks

Borrelia burgdorferi

Spiral morphology, large; motile; slow growth; gram(-), zoonotic pathogens, hard to isolate in culture, complex nutritional needs, flexible peptidoglycan cell wall around which several axial endoflagella are wound Black legged tick (Ixodes) Antigenic variation - escape immune clearance, modulation of host immune system - inhibition of mononuclear and

natural kill cell function,

anti-OspA has autoimmune

activities

OspA (in tick), OspC (in mammals); toxic LPS; downregulation of immune functions; possible autoimmune response

Stage1 (localized infect.): erythema migrans (bull's eye appearance) + flu-like symptoms; Stage2 (disseminated infect.): cardiac and

neurologic (nerve palsies) abnormalities; Stage3 (persistent infection): fluctuating

arthritis.

CDC:ELISA or IFA then Western blot, serologic - later stages, culture - not rec, OCT -

not standardized Tetracycline (doxycycline), amoxicillin, or cefuroxime, Vaccine no longer available Borrelia

recurrentis Relapsing FeverEpidemic Human body louse

Crushing infected louse + scratching Endotoxin (febrile illness); Recurrent episodes of fever + septicemia separated by afebrile periods; new set of surface antigens at each relapse

High fever, headache, muscle pain, weakness. 2-4 days between relapses; 2-3 relapse

cycles; possible myocarditis.

Microscopy (during febrile period) Giemsa or Wright staining; Serologic tests unhelpful (because of antigenic variation) Tetracycline (doxycycline) or erythromycin other Borrelia

spp. Relapsing FeverEndemic

Leptospira interrogans

Spiral morphology; motile; slow growth; gram(-) but not seen on gram stain;

zoonotic pathogen, tight terminal hooks Shed in urine of infected animals Direct contact with urine, blood or tissues of infected animals; Contact with contaminated water

Multiply in blood and tissues; damage endothelium of small blood vessels;

no virulent factors known

both febrile: Septicemic phase: flu-like symptoms; Immune phase: anicteric form (possible meningitis), icteric form or Weil's disease (jaundice, renal + pulmonary dysfunctions, subconjunctival hemorrhage)

Culture: from blood, CSF during septicemic

phase; from urine during immune phase;

slow growth, special media, PCR - not widely available. Serologic tests: agglutination test Penicillin or Doxycycline ETEC EnteroToxigenic E. coli Enterobacteriacea e; Motile; lactose(+) Traveler's

Diarrhea Human's intestine

Cfa (colonization factor antigen) - adherence; ST (heat stable toxin) -

guanylate cyclase activation → ↑ [cGMP]; LT (heat labile toxin, AB toxin) - ADP ribosylates G protein →

activation of adenylate cyclase → [↑cAMP]; High cGMP or cAMP → hypersecretion of H2O and Cl; ↓ in Na

reabsorption

Fluoroquinolon es (ciprofloxacin),

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G I I N F E C T IO N S W a te ry D ia rr h e a S m a ll in te s ti n e d is e a s e N o in v a s io n , n o in fl a m m a ti o n

Watery diarrhea Immunoassays

F lu id + e le c tr o ly te r e p la c e m e n t

Chronic diarrhea Fecal-oral Immunoassays

Fecal-oral Stool culture at 25°C

Watery diarrhea Enterotoxin - chloride secretion Watery diarrhea, abdominal cramps, nausea Self-limiting

W a te ry t o B lo o d y D ia rr h e a L a rg e In te s ti n e F lu id + e le c tr o ly te r e p la c e m e n t Dysentery Fecal-oral

Ruffles, invasion, inflammation Enterobacteriacea e; Motile; lactose(+) EPEC EnteroPathogenic E. coli Human's intestine Fecal-oral, LOW in infants (person-to-person); high in adults Bfp (Bundle-forming pilus) - adherence; Type III secretion system → cytoskeleton proteins modification in host cell; Attaching and effacing lesions → changes in microvilli →

malabsorption

Watery diarrhea, abdominal cramps (INFANTS) Fluoroquinolon es (ciprofloxacin), TMP/SMX EAEC EnteroAggregativ e E. coli Human's intestine Bfp (Bundle-forming pili) → autoagglutination "stacked-brick" arrangement + biofilm → malabsorption

Chronic watery diarrhea (in AIDS patients), abdominal cramps, dehydration in infants and

children ~ growth retardation

Fluoroquinolon es (ciprofloxacin), TMP/SMX Yersinia enterocolitica (Y. pseudotuberculosi s - uncommon) Enterobacteriacea e; Bipolar staining; lactose (-), zoonotic Watery diarrhea, gastroenteritis Animal's intestine

Invade M cells: Yops and Type III secretion system; gene expression

under Ca and T control, virulence genes, spread Æ microabscesses in

lymph nodes

Watery diarrhea, abdominal cramps, fever; mesenteric lymphadenitis (mimics acute appendicitis) other: arthritis, intra-abdominal

abscess, septicemia, osteomyelitis

Fluoroquinolon es or doxycycline + gentamycin Vibrio Cholerae (serogroups O1 and O139) Curved gram(-) rods; facultative anaerobes, oxidase(+), motile (polar flagella) Cholera and gastroenteritis Warm costal water, asymptomati c carriers Ingestion of contaminated water or shellfish

Tcp (toxin coregulated pilus) - adherence; Ctx (cholera toxin, AB-toxin, on lysogenic CTXФ phage) - ADP ribosylates G protein → constant

activation of adenylate cyclase → ↑cAMP → hypersecretion of H2O and

Cl; decrease in Na reabsorption

Profuse watery diarrhea; "rice-water" stools; severe dehydration → hypovolemic shock

TCBS (Thiosulfate citrate bile salts sucrose agar) - yellow

colonies Ciprofloxacin or doxycycline Vibrio parahaemolyticus Warm costal water (marine life) Ingestion of contaminated seafood TCBS - blue-green colonies; Halophilic EHEC EnteroHemorrhag ic E. coli (O157:H7) Enterobacteriaceae; Motile; lactose(+), sorbitol(-) - "spinach outbreak" Hemorrhagic Colitis; Hemolytic Uremic Syndrome (HUS) Intestine of cattle Fecal-oral, LOW → person-to-person transmission

Attaching & Effacing lesions (no invasion); Shiga toxin (AB toxin) - cleaves rRNA → blocks protein synthesis → cell death; circulating shiga toxin can bind to renal tissue →

renal failure (HUS)

Bloody diarrhea (no leucocytes), abdominal cramps, vomiting; oliguria+renal failure (HUS)

Culture on MacConkey agar (sorbitol(-)); Immunoassays Antibiotic therapy not recommended; dialysis in HUS cases EIEC EnteroInvasive E. coli Enterobacteriaceae;

Motile; lactose(+) Human's intestine

Invasion and destruction of colonic epithelium, virulent plnv genes,

INACTIVATE RIBOSOMAL SUBUNITS

Bloody diarrhea with pus, fever, abdominal cramps, nausea Immunoassays, sorbitol (-), glucuronidase (-) Fluoroquinolon es (ciprofloxacin), TMP/SMX Shigella spp. (S. sonnei) Enterobacteriaceae; Non-motile; lactose(-) Dysentery, shigellosis (gastroenteritis) Human's intestine Fecal-oral, LOW → person-to-person transmission

Invasion of colonic mucosa through M cells; Invade basal surface of

enterocytes → cell death + inflammation, focal ulcer; shiga-toxin,

cleaves rRNA - HUS (see above), acid resistant, endotoxin

Bloody diarrhea with pus, fever, abdominal cramps, nausea (first watery then blood

mucoid stools)

Hektoen enteric agar: lac(-), H2S(-) → green colonies Fluoroquinolon es (ciprofloxacin), TMP/SMX Salmonella enterica (enteritidis & typhimurium) Enterobacteriaceae; Motile; lactose(-) Dysentery-like diarrhea; possible bacteremia Intestinal tracts of animals and humans Fecal-oral; ingestion of contaminated food (eggs, poultry) or water; direct contact with reptiles

Bloody diarrhea with pus, fever, abdominal cramps, nausea

Hektoen enteric agar: lac(-), H2S(+) → blue colonies with dark

center Fluoroquinolon es (ciprofloxacin), TMP/SMX Campylobacter jejuni

Thin gram(-) rods; spiral shape; microaerophile;

oxydase(+),

Dysentery-like

diarrhea Animal's intestine

Fecal-oral; ingestion of contaminated food (poultry), milk or water; direct contact with pets, LOW

Invasion of intestinal mucosa; virulence factors poorly defined

Bloody diarrhea with pus, fever, abdominal pain; Complications: Guillain-Barre

syndrome, Reactive arthritis

Culture (microaerophilic conditions - ↑ T - 42°C, blood or charcoal media) Fluoroquinolon es (ciprofloxacin) or erythromycin

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G I I N F E C T IO N S

Salmonella typhi Typhoid fever

Bacillus cereus Ubiquitous Ubiquitous C lo s tr id iu m s p p & G I i n fe c ti o n s difficile Watery diarrhea

Profuse diarrhea, abdominal cramps, fever

Watery diarrhea Watery diarrhea + abdominal cramps Self-limiting

Penicillin

Clinical

Infant botulism "floppy baby"

C N S IN F E C T IO N S B a c te ri a l M e n in g it is C S F : W B C s , ↑ p ro te in s , ↓ g lu c o s e Enterobacteriaceae; Non-motile; lactose(-) Humans only Fecal-oral; Mod-low (possible person-to-person trans)

Invasion of M cells; Multiply in macrophages; bacteremia and invasion of RES (mesenteric lymph

node, liver, spleen); infection of gallbladder (carrier state); Capsule (Vi

polysaccharide); endotoxin

Sustained fever and headache; possible rash and/or diarrhea; persistent bacteremia → myocarditis, encephalopathy…constipation

more common, diarrhea = late in disease

Culture from blood or feces, Hektoen enteric agar: → blue colonies

with dark center

Fluoroquinolones (ciprofloxacin), TMP/SMX Helicobacter pylori Gram(-) rods; bacillary or spiral shape; microaerophile; oxydase(+); urease (+) Gastritis, peptic ulcer, gastric adenocarcinoma, lymphomas Stomach of humans and animals Fecal-oral; oral-oral

Mucous layer invasion (Mucinase, phospholipase, flagella) + Alteration

of gastric acid production (urease -> ammonium production) → Inflammation of gastric mucosa →

Tissue destruction

Biopsy=> microscopy, culture, urease test;

Stool antigen test; Urea breath test; PCR

Proton pump inhibitor + clarithromycin + amoxicillin or metronidazole Gram(+) rods, motile; spore forming Emetic gastroenteritis Ingestion of preformed toxin (rice)

Heat-stable enterotoxin (if spore survive cooking → germination + toxin

production in non-refrigerated food)

Onset <6h after ingestion - Vomiting, nausea,

abdominal cramps Isolation of organism from implicated food, β-hemolysis on blood agar Self-limiting; Fluid + electrolyte replacement Diarrheal gastroenteritis Ingestion of food contaminated with spore

Heat-labile enterotoxin (germination of spore + toxin production in

intestinal tract)

Incubation time >6h - Watery diarrhea, nausea, abdominal cramps

Staphylococcus aureus Gram(+) cocci in cluster, catalase(+); coagulase(+) Staphylococcal food poisoning Normal human flora Ingestion of preformed toxin (potato salad, custard…)

Heat stable enterotoxin → acute inflammation of gastric mucosa, small

intestine

Onset <6h after ingestion - Vomiting, nausea, abdominal cramps and watery diarrhea

Isolation of toxin producing bacteria (mannitol salt agar)

Self-limiting; Fluid + electrolyte replacement Large gram(+) rods; Spore forming; Strict anaerobes Antibiotic-associated diarrhea Vegetative form: human carrier; Spore in environment (hospital rooms) Endogenous infection Exposure to antibiotics → overgrowth of C. difficile (endogenous); Toxin A - Enterotoxin: disrupts tight junctions

between enterocytes + induces inflammation → watery diarrhea; Toxin B - cytotoxin: modification of enterocyte cytoskeleton → cell death

Immunoassays (toxins detection); colonoscopy (pseudomembrane) Discontinue implicated antibiotic; vancomycin Antibiotic-associated pseudomembrano us colitis Clostridium

perfringens human colonSoil and

Ingestion of spore or bacteria

Enterotoxin: alteration of membrane

permeability in enterocytes _{Culture; Immunoassay}

(enterotoxin detection) Necrotizing

enteritis β-toxin (lethal toxin): necrotizing destruction of jejunum

Bloody diarrhea; abdominal pain; vomiting, peritonitis Clostridium botulinum Botulism, neuromuscular paralysis Spores in soil and dust Ingestion of preformed toxin, LOW

Botulinum toxin=AB neurotoxin → blocks release of acetylcholine from peripheral nerves → flaccid paralysis

Weakness, dizziness, then neurological features: blurred vision, drooping eyelids… respiratory paralysis. THREE Ds: DIPLOPIA,

DYSPHAGIA, DYSPHONIA trivalent botulinum

Antitoxin Spores in soil and dust Ingestion of spore (honey), LOW

Germination of spores in colon → multiplication of vegetative form →

neurotoxin production Clinical + C. botulinum found in feces Streptococcus pneumoniae lancet-shaped, gram (+) cocci, chain or diplo, catalase (-) pneumococcal meningitis in adults throat & nasopharynx person-to-person via respiratory droplets

nasopharynx → infection of lung or eustachian tube → inflammation or OM → bacteremia, meningitis.

Polysaccharide capsule: antiphagotic, pneumolysin: transmembrane pore-forming toxin, IgA protease, others: teichoic acid, peptidoglycan fragment, hydrogen

peroxide h ig h f e v e r, H A , s ti ff n ec k . In fa n ts : s lo w -a p p e a ri n g , i rr it ab le , v o m it in g , o r p o o r fe e d in g

acute onset, complications: mental retardation, learning disabilities,

deafness gram stain: WBCs + gram(+) cocci, Culture: mucoid, α-hemolytic, Optochin sensitive, bacitracin resistant, bile solubility (+), capsule (+) quellung vancomycin + 3rd gen cephalosporin (ceftriaxone or cefotaxime), Prompt txt of OM and respiratory infections. VACCINES: 7-valent conjugated vaccine, 23-valent polysaccharide vaccine.

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C N S IN F E C T IO N S B a c te ri a l M e n in g it is nasopharynx C S F : W B C s , ↑ p ro te in s , ↓ g lu c o s e C N S IN F E C T IO N S C A M P t e s t E. coli O th e r h ig h f e v e r, H A , s ti ff n ec k . In fa n ts : s lo w -a p p e a ri n g , i rr it ab le , v o m it in g , o r p o o r fe e d in g Neisseria meningitidis aerobic gram (-) diplococci, polysaccharide capsule (A, B, C, Y, W135), flattened adjacent sides meningococcal

meningitis respiratory droplets

initial infection of upper resp tract → attachment to non-ciliated cells of

nasopharynx: pili, IgA protease (colonization), capsule → invasion

into bloodstream → brain. Diffuse vascular damage: endotoxins (LPS,

LOS)

hemorrhagic skin rash (petechiae). Waterhouse-Friderichsen syndrome (ADRENALS), complications: 11-19%

permanent hearing loss, mental retardation, etc

gram stain of CSF, culture: Thayer-Martin agar (mod chocolate agar) + 5% CO2. MALTOSE & GLUCOSE (+) cefotaxime or ceftriaxone (10-15% fatal, 100% if untreated), antimicrobial chemoprophylaxis: rifampin or ciprofloxacin, VACCINES: MPSV4, MCV4 Haemophilus influenzae type b gram (-) pleomorphic coccobacillus, capsule serovar b Haemophilus meningitis and sepsis human nasopharynx direct contact with respiratory droplets. Risk: infants - young children nasopharynx → invasion → bacteremia → CNS. Pili, IgA protease, polysaccharide capsule:

type-b: poly-ribitol-phosphate, endotoxin (LPS) - inflammation

initially: runny nose, low grade fever, HA, complications: 20% - hearing loss, delayed language development or

mental retardation culture: chocolate agar, X and V factors, gram (-) coccobacilli or rods. Antigen detection, latex test cefotaxime or ceftriaxone, Hib conjugate vaccine. Rifampin prophylaxis B a c te ri a l M e n in g it is i n N e o n a te s Streptococcus agalactiae (Group B hemolytic streptococcus) gram (+) cocci in short chains, β-hemolytic or nonhemolytic, group B lancefield capsular antigen, bile resistant, polysaccharide capsule meningitis in

neonates GI tract, vagina

infection during delivery, nosocomial transmission

capsule rich in sialic acid, peptidase

- inactivates C5a, hydrolytic enzymes nonspecific: fever, feeding difficulty, vomiting, diarrhea, respiratory distress,

irritability alternating with lethargy

PCR, latex particle agglutination test of urine: rapid, CSF and blood cultures, CSF: difficult in neonates. Bacterial culture from mother. antiviral (acyclovir) + antibacterial (ampicillin + cefotaxime) gram (-) rod, K1 polysaccharide capsule

capsule (sialic acid, ~ meningococcus), pili Listeria monocytogenes gram (+) rods, catalase (+), β-hemolysis host-dependent: listerosis, sepsis, meningitis, fetal loss intestine of animals and humans ingestion of contaminated food, transplacental , during delivery

pathogenic serotypes have unique teichoic acid, facultative intracellular pathogen: growth in cells, internalins:

attachment and entry, listeriolysin O: pore-forming exotoxin, ActA: actin polymerization: motile comet tails

Bacteremia: occult, proliferate in placenta. Neonatal: early onset sepsis - "granulomatosis infantisepticum", late-onset

meningitis: via vaginal transmission. CNS: meningitis, encephalitis, brain abscess in

10%. Febrile gastroenteritis (IC+), (IC- and old: sepsis and meningitis, pregnant: flu-like

illness, fetal loss.

broad T range, motile at 25˚C - "TUMBLING",

non-motile at 37˚C, microscopy - wet mount, culture: blood

agar, β-hemolytic, CSF: pleocytosis, ↑ protein, ↓ glucose ampicillin + gentamicin Mycobacterium tuberculosis obligate aerobe, rod shaped, facultative intracellular pathogen, acid-fast bacteria tuberculous meningitis reservoir - infected humans. Inhalation of infectious aerosols

Mycolic acid, sulfolipids, cord factor,

tuberculin + mycolic acid anorexia → brain abscesses, spinal TBgradual onset (weeks), malaise, apathy,

CXR, PPD skin test, Ziehl-Neelsen stain = acid fast stain. Culture

confirms dx. Lowenstein-Jensen medium = lipid rich

ACTIVE: combo: isoniazid, rifampin (4m), pyrazinamide

(2m), ethambutol. LATENT: isoniazid.

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C N S IN F E C T IO N S C lo s tr id iu m S p p

Clostridium tetani clinical

E Y E IN F E C T IO N S B a c te ri a l C o n ju n c ti v it is : p u ru le n t d is c h a rg e , c o n ju n c ti v a l h y p e re m ia Direct contact gram (+) rods, strict anaerobes, no capsule, motile, spore-forming - drumstick appearance tetanus: generalized, localized, cephalic, neonatal spores: ubiquitous

enter body via wound, developing countries: non-sterile techniques, umbilical stump → neonatal tetanus

spore: survival in environment, tetanolysin (not sig), tetanospasmin: heat labile AB

neurotoxin, blocks release of inhibitory NTs (GLYCINE)→ constant contraction (spasms), highly toxic. Anaerobic conditions

→ germination of spores, local bacterial multiplication, toxin production → enters nervous system peripherally → carried to

CNS

severe painful spasms and rigidity of voluntary muscles, early = lockjaw, exg reflexes,

muscle rigidity → apnea, fractures, dislocations, death from respiratory failure

neutralization of unbound toxins (toxin binding is irreversible), supportive, metronidazole to eliminate bacteria in wound, Vaccine Clostridium botulinum gram (+) rods, fastidious, spore forming, strict anaerobes botulism: foodborne, infant, wound, neuroparalytic illness soil, contaminate d foods spores survive sterilizing process and improper canning procedures

spore, botulinum toxin: heat labile AB-neurotoxins, blocks release of Ach

from peripheral nerves → flaccid paralysis, type A most significant in US, highly toxic. Path: ingestion of

preformed toxin

weakness, dizziness, dryness of mouth (N and V), neuro: B/L flaccid paralysis and motor and autonomic nerves, blurred/double vision, drooping eyelids, difficulty swallowing, speech,

descending weakness, respiratory paralysis

mainly clinical, mouse bioassay

trivalent botulinum antitoxin (A, B, E),

respiratory support, elimination of bacteria: gastric lavage, metronidazole or PNC Streptococcus pneumoniae gram (+) diplococci or chains, catalase (-) Acute Bacterial Conjunctivitis

polysaccharide capsule, autolysin, pneumolysin O

burning, irritation, tearing, mucopurulent discharge

α-hemolytic on blood agar - large mucoid

colonies, Optochin sensitive, bacitracin resistant, bile soluble

Empiric txt w/ topical antibiotics,

Gati/levo/ moxifloxacin Hemophilus

influenzae pleomorphic rodgram (-)

pili, lipopolysaccharides, IgA-specific protease, polysaccharide

capsule

chocolate agar (X & V factors) Staphylococcus aureus gram (+) cocci, clusters, catalase (+), coagulase (+)

protein A (inhibits phagocytosis), fibrinogen-binding protein (clumping factor), coagulase,

cytotoxic toxins

β-hemolysis, mannitol-salt agar, yellow

colones Chlamydia trachomatis small obligate INTRACELLULAR, no PG layer; elementary & reticulate bodies trachoma, urogenital infections (Sero A-C)

Direct contact; hand to eye, contaminated clothing,

flies

Direct contact/newborn via birth canal → tropism for epithelial cells of conjunctiva; intracellular pathogen

(evades host defense, killing host cell); LPS (inflammation) → severe

inflam response → necrosis, fibrosis, scarring

Trachoma: leading cause of blindness in world, mostly children, ~ poor hygiene. Chronic, inflam granulomatous dz of eye surface → corneal ulceration, scarring, pannus

formation → blindness

from conjunctival fluid or surface scrapings; gram stain/culture;

immuno-fluorescence, cytologic exam (I)

azithromycin or doxycycline, erythromycin (newborn). inclusion conjunctivitis (sero D-K) ocular-genital contact, acquired from infected mom

Adult: acute infections --> mucopurulent d/c, infiltrates, corneal scarring in chronic form; sexually active - preceded by genital infection. Newborn: swelling of eyelids, copious purulent

d/c

lymphogranuloma venereum (sero L1 - L3)