Bacteria Flashcards
Listeria Monocytogenes
- Motile
- Fac anaerobe
- Catalase +
*Grows at cold temp
Transmission: - Vertical
- Food borne (dairy products, soft cheeses, deli meats, contaminated veggies)
- Immunosuppressed (transplant, steroid, cancer/chemo) & old/young
Disease: - Most virulent (20-30% result in death of high risk pts)
- Pregnant mothers: influenza-like symptoms; HA, malaise, fever, backache, nausea, chills, diarrhea
- infects placenta & fetus
- can cause premature labor
*Adult: Self limited GI illness (24 hr after ingestion) or invasive disease (30 days after); sepsis and/or meningitis
Neonatal Listeriosis:
* Early onset (< 5d): sepsis or meningitis
*Late onset (>5d): purulent meningitis
* Microabscesses/granulomas in organs
* Most have underlying immunodeficiency
Diagnosis: Blood culture, CSF, skin lesion cultures
Treatment: Ampicillin + Gentamicin
Gram pos rods
Bacillus anthrasis
*Spore forming
*Fac anaerobe
* Non-motile
* Protein capsule (Glu)
*Boxcar shape (spore in center)
Transmission:
* Animals or animal products
* Exotoxins (A-B)
* Cutaneous, inhalation & GI
Virulence Factors:
* Anthrax toxin –> Edema
Disease:
* Painless papule at entry site –> eschar
*Bacteria can spread via lymphatics causing severe disease & death
*Airborne exposure to spores –> pneumonia, mediastinal hemorrhage, bloodstream infection, death
Diagnosis:
* Skin/blood culture
*PCR
Treatment:
* Ciprofloxacin (penicillin & doxycycline)
*Systemic antibiotic if cutaneous anthrax (20% chance of dissemination)
Vaccine:
*Vaccine exists
Gram pos rods
Bacillus cereus
”* Spore forming
* Motile
B-hemolytic
* Fac anaerobe”
Transmission:Reheated rice
Virulence Factors:” Pre-formed enterotoxin: heat-stable, water soluble exotoxin; forms pores in cell membranes of cells lining intestine; inactivated when heated to 133’F
Cereulide: toxin that is NOT heat inactivated; leads to emetic form (vomiting)”
Disease:” Food poisoning: Spores germinate in food that sits out exposed to environment & cause N/V 1-6 hr after and diarrheal toxin 8-16 hr after ingestion
* Excessive amt of toxin can mimic sepsis”
Diagnosis:
Treatment:
Gram pos rods
Corneybacterium diphtheria
”* V shape
* Pleomorphic
Non-motile
* Fac anaerobe
* Catalase +”
Transmission:
Virulence Factors: “ Diphtheria toxin (A-B toxin)
*Exotoxin encoded by bacteriophage that inactivates EF-2, inhibiting protein synthesis”
Disease: “Diphteria:
* sore throat, swollen glands, difficulty breathing, fever, malaise
*Bull’s neck
Pseudomembranous pharyngitis (grey-white membrane) with lymphadenopathy, myocarditis, arrhythmias”
Diagnosis:
Treatment: “Diptheria antitoxin (DAT)
*Erythromycin or penicillin”
* DTaP vaccine
Gram pos rods
Clostridium tetani
”* Club shaped
* Terminal spore
* Ob anaerobe
Motile
B-hemolytic”
Transmission: “ Spores persist for months
* NOT transmitted btw pts”
Virulence Factors: “ Tetanus toxin (A-B toxin)
* Tetanospasmin: neurotoxin”
Disease: “Tetanus
* Binds gangliosides at neural junction of skeletal muscles & neuronal membranes in spinal cord –> inhibits release of inhibitory neurotransmitters (GABA)
* Spastic paralysis, muscle rigidity, lockjaw”
Diagnosis:
Treatment:
”* DTaP vaccine
*10 yr booster shots”
Gram pos rods
Clostridium difficile
”* Club shaped
* Terminal spore
* Ob anaerobe
* Motile
* capsule”
Transmission:
Virulence Factors: * Enterotoxin A & B
Disease: Pseudomembranous colitis
Diagnosis:
Treatment:
Gram pos rods
Clostridium botulinum
”* Club shaped
* Terminal spore
* Ob anaerobe
* Motile
* B-hemolytic”
Transmission: *Home canned food containing toxins
Virulence Factors: * Botulinum toxin (A-B toxin): absorbed from gut & blocks neurotransmission at peripehral nerve synapses
Disease: Botulism
* Flaccid paralysis, muscle weakness, resp arrest, descending paralysis
*neuro sx 12-36 after toxin ingestion
* NO fever & pt remains responsive
Infant Botulism: Flaccid paralysis with ingestion of honey containing spores
Wound Botulism: contamination of open wound w spores; same presentation,
Diagnosis:
Treatment: “* Antitoxin
*Supportive care
* Spontaneous recovery can take up to 100 days
* Wound: debridement, penicillin + antitoxin”
Gram pos rods
Clostridium perfringens
”* Club shaped
* Terminal spore
* Ob anaerobe
* B-hemolytic
* Non-motile”
Transmission: Preformed toxin in gravies/meats
Virulence Factors: * Alpha toxin
Disease: “ Gas gangrene
* Food poisoning: watery, foul smelling diarrhea 8-16 hr after ingestion due to spore or preformed toxin contaminating food (possibly bloody)”
Diagnosis:
Treatment:
Gram pos rods
Streptococci
- Catalase neg
Transmission:
Virulence Factors:
Disease:
Diagnosis:
Treatment:
Gram pos cocci
S. mitis (viridans)
”* A-hemolytic
* Fac anaerobe
* Optochin R”
Transmission: *Oral microbiota
Virulence Factors:
Disease: *Endocarditis (synthesizes dextran from glucose & use to adhere to fibrin-plt aggregates on damaged heart valves)
Diagnosis:
Treatment:
Gram pos rods
S. mutans (viridans)
”* A-hemolytic
* Fac anaerobe
Optochin R”
Transmission:
Virulence Factors:
Disease: “ Dental carries
*Endocarditis (synthesizes dextran from glucose & use to adhere to fibrin-plt aggregates on damaged heart valves)”
Diagnosis:
Treatment:
Gram pos rods
S. pneumoniae
”* A-hemolytic
* Fac anaerobe
* Capsule
* Lancet shaped diplococci
* Optochin S”
Transmission: “* Resp transmission
* Risk factors: asplenia, smoker, CSF leak, cochlear implant, SCD, HIV, day care”
Virulence Factors: * Capsule
Disease: “* Most common cause of pneumonia & bacteria meningitis
* C-MOPS: conjunctivitis, meningitis, otitis media, pneumonia (lobar), sinusitis, septicemia”
Diagnosis:
Treatment:
”* PPSV23 (Pneumovax): polysaccharide vaccine
- > 65 yo & > 2 yo if at increased risk
- Not for < 2 yo
- Less effective in preventing pneumonia
* PCV13: Conjugated to diphtheria toxin
- infants & adults > 65 yo”
Gram pos rods
S. pyogenes (GAS)
”* B-hemolytic
* Fac anaerobe
* Capsule
* Chains
* Bacitracin S
* Pyogenic (pus)”
Transmission: * Usually children 4-8 yo
Virulence Factors: “* Erythogenic exotoxin A (produced when infected w certain bacteriphage; skin rash/fever of scarlet fever & superantigen that causes proliferation of T cells & cytokines –> shock)
SpeA, SpeB (TSS)
* Streptolysin O/S (hemolysis)”
Disease: “ Pharyngitis (strep throat), cellulitis, PSGN, necrotizing fasciitis, rheumatic fever
* Scarlet Fever: pharyngitis, fever then diffuse palpable, sandpaper-like eruption starting on abdomen & disseminates (4-8 yo), strawberry tongue, normal conjunctiva/lips, desquamation during recovery
*Toxic Shock Syndrome (SpeA & SpeB) –> erythroderma (sunburn-like diffuse reddening of skin)
Compared to Staph: 20-50 yo, equal sex, severe pain common, erytheroderma (sunburn like reddening of skin) less common, higher bacteremia, tissue necrosis more common, cuts/burns predispose pt, higher mortality rate”
Diagnosis:
Treatment: “* Penicillin
*IVIG”
Gram pos rods
S. agalactiae (GBS)
”* B-hemolytic
* Fac anaerobe
* Capsule
* Chains
* Bacitracin R”
Transmission: “GI/GU microbiota
* Acquired during vaginal birth (50% w/o intrapartum abx)”
Virulence Factors:
Disease: “Adults: UTIs, skin/soft tissue infections, osteomyelitis, meningitis, endocarditis
Neonatal Infection:
* Early onset (< 7 days): septicemia, pneumonia, meningitis
* Late onset (7-89 days): Bacteremia w/o focus, meningitis, osteomyelitis, pyogenic arthritis, cellulitis, adenitis
*Major cause of bacterial neonatal sepsis, pneumonia, meningitis”
Diagnosis:
Treatment:
Gram pos rods
S. bovis (GDS)
”* y-hemolytic
* Oxidase neg
* Doesn’t grow on NaCl”
Transmission: “* GI microbiota
* Cattle feces”
Virulence Factors:
Disease: “* Endocarditis, sepsis, UTIs
* rarely neonatal sepsis & meningitis”
Diagnosis:
Treatment:
Gram pos rods
Enterococcus faecalis & faecium
”* y-hemolytic
* Fac anaerobe
* Oxidase neg
* Bile R
* Grows in NaCl
* Yellow on mannitol (faecalis)”
Transmission: “* Persist on fomites
* E. faecalis is more common
* E. faecium is more likely to be VRE (ESKAPE pathogen)”
Virulence Factors:
Disease: * UTIs, peritonitis (abdominal swelling/tenderness, fever), wound infections, bacteremia
Diagnosis:
Treatment:
Gram pos rods
Staphylococcus aureus
“Catalase +
B-hemolytic
* Fac anaerobe
*Coagulase +
* Capsule”
Transmission: “ Skin flora (ESKAPE pathogen)
* Contaminated high protein foods, creat or egg based dishes”
Virulence Factors: “ A-toxin (hemolysis)
*B-toxin (sphingomyelinase)
* Hemolysin (hemolysis)
* Leukocidin (destroys leukocytes)
* Enterotoxins (heat-stable, food poisoning)
TSST-1 (superantigen, release of cytokines -> TSS)
* Epidermolytic/exfoliative (epithelial cell lysis, scalded skin syndrome)”
Disease: “ Inflammation –> pus, tissue necrosis, boil/abscess formation
* Minor skin infections (pimples, impetigo, boils, cellulitis, abscesses)
* Serious: osteomyelitis, pneumonia, meningitis, gastroenteritis, endocarditis, bacteremia
*TSS: Diffuse inflammatory response with fever, rash, hypotension & multi-organ involvement (TSST-1); erythroderma in 24-48 hr
* Scalded Skin Syndrome: Exfoliative toxins A & B act at remote site targeting desmoglein-1 (cell-cell attachment in epidermis); low grade fever followed by skin peeling & red/tender areas; rash spreads to other parts of body; desquamation during crescendo phase
- Nikolsky Sign: cleavage of stratum granulosum layer of epidermis
*Food poisoning: N/V 3-4 hr after ingestion that resolves within 24 hr (NOT diarrhea which IS seen w Bacillus cereus & Clostridium perfringens)
Compared to GAS: Mainly 15-35 yo, women more often, rarely severe pain, erytherodema (sunburn like reddening of skin) very common, low bacteremia, tissue necrosis rarely, tampons/varicella predispose pt, low mortality rate”
Diagnosis:
Treatment:
Gram pos rods
S. epidermidis & saprophyticus (CoNS)
”* Catalase +
* y-hemolytic
* Fac anaerobe
* Coagulase neg
* Forms biofilm”
Transmission:
Virulence Factors:
Disease: “* Endocarditis, UTIs, osteomyelitis
* S epidermidis: intravascular device, prosthetic joints, catheter, wound infections; produces polysaccharide adhesin that aids in attachment to surfaces
*S saprophyticus: Most common gram + cause of UTIs (novobiocin R)”
Diagnosis:
Treatment:
Gram pos rods
Nocardia spp
“*Aerobe
*Catalase +
Partially acid fast”
Transmission: “Soil
*Oral microbiome”
Virulence Factors:
Disease: * Nardiosis: pulmonary virulent form of pneumonia or meningitis in immuncompromised
Diagnosis:
Treatment:
Gram Pos Branching
Actinomyces isrealii
”* Oblgate anaerobe
* Catalase variable
* NOT acid fast”
Transmission: “* Vaginal, oral or GI microbiome
*Soil”
Virulence Factors:
Disease: * Actinomycosis: formation of abscesses in mouth, lungs or GI tract in immunocompromised
Diagnosis:
Treatment:
Gram Pos Branching
Neisseria meningitidis
”* Aerobe
* Capsule
Catalase +
Oxidase +
* Serogroups based on capsule”
Transmission: “Nasopharynx of some
* Resp transmission
* Risk factors: sub-Saharan Africa, terminal comp def, asplenia, Properiden def, HIV, Eculizumab”
Virulence Factors: “Direct contact, resp trasmission
* Risk factors: late comp deficiency, asplenia, close contact”
Disease: “* Meningitis & meningococcemia
*Abrupt onset w fever, chills, malaise, myalgia, limb pain, prostration, rash
* Maculopapular rash –> petechial –> purpura
* Purpura fulminans: cutaneous hemorrhage & tissue necrosis, hypotension, DIC, sepsis
Most invasive serogroups: A, B, C, Y, W-135”
Diagnosis:
Treatment: “ Rifampin, Ciprofloxacin or Ceftriaxone: PPX for close contacts
*3rd gen cephalosporin”
Vaccine: “Do NOT protect against Men B:
* Quad Men Conjugate Vaccine (MCV4, Menactra, Menveo): Polysaccharide conjugated to diptheria toxoid that targets A, C, Y, W-135 (2 mo-55 yo)
- 11-12 yo + booster at 16 yo
* MENHIBRIX: Men C/Y, HiB, tetanus toxoid conjugate vaccine (6wk-18mo)
Men B Protection:
*Bexsero/Trumenba: 16-18 yo; used in those at increased risk at > 10 yo; many colleges require it”
Gram Neg Diplococci
Neisseria gonorrhoeae
”* Aerobe
*Non-motile
* Non spore forming
* Oxidase +
*Kidney bean shape”
Transmission:
Virulence Factors: *Varies surface antigens (evades immune system)
Disease: “Gonorrhea:
* Women more asymptomatic than men
* Can cause disseminated disease
* Urethritis: discharge, dysuria, pruritus
*Cervicitis: discharge, intermenstrual bleeding”
Diagnosis: Cervicitis: gram stain, wet mount, NAAT, culture, PCR
Treatment: “ Ceftriaxone (uncomplicated GC of cervix, urethra, rectum)
*Doxyclcine for chlamydia if not excluded”
Gram Neg Diplococci
Bordetella pertussis
“Aerobe
* Catalase +
* Oxidase +
* B-hemolytic
* Capsule”
Transmission: “ Resp transmission
* Incubation period = 5-10 days”
Virulence Factors: “* Adhesion: fimbrae, adhesins (petractin, filamentous hemagglutinin)
*Exotoxins: Tracheal cytotoxin, pertussis toxin (A-B toxin), adenylate cyclase toxin”
Disease: “Whooping cough:
* Catarrhal stage: URI (1-2 wk) –> Paroxysmal stage: inspiratory whoop w vomiting (1-6 wk)–> Convalescent stage: symptoms wane (wk-mo)
* Pertussis toxin inhibits Gi proteins –> overactive adenylate cyclase –> high cAMP causing impaired recruitment of neutrophils
* Bacteria attach to cilia of resp epithelial cells
* Complications in young: apnea, pneumonia, seizures, death, encephalopathy
* Complications in adults: pneumonia, rib fracture, weight loss, hernia, urinary incontinence”
Diagnosis:
Treatment:
”* DTaP vaccine (acellular vaccine)
* Every pregnancy to protect fetus”
Gram Neg Coccobacilli
Haemophilus influenzae
”* Chocolate agar (Requires factor 5-NAD, 10-hematin)
* Fac anaerobe
Capsule
Oxidase +
* Coccobacillary”
Transmission: “ Aerosol transmission
Risk factors: < 4 yo, SCD/asplenia, HIV, Native American”
Virulence Factors:
Disease: “Type B strains are most invasive; non-typable strains cause mucosal infections (OM, bronchitis)
* EMOP: Epiglottitis, Meningitis, OM, Pneumonia
* Causes severe infection in infants: bacteremia, septic arthritis, cellulitis, purulent pericarditis
* Unencapsulated strains cause OM, conjunctivitis, sinusitis in children (unaffected by vaccine)
* Does NOT cause flu”
Diagnosis:
Treatment: “ Rifampin: PPX for close contact
*Amoxicillin for mucosal infections??? (Sketchy)”
* HiB vaccine: contains type B capsular polysaccharide (PRP) conjugated to diptheria toxoid or another protein
Gram Neg Coccobacilli
Haemophilus ducreyi
“*Fastidious
Fac anaerobe
* Choc agar only”
Transmission:
Virulence Factors:
Disease: Chancroid: PAINFUL genital ulcer & tender suppurative inguinal lymphadenopathy
Diagnosis: “ Microscopy/Ag detection are NOT sensitive nor specific &PCR is NOT FDA approved
All of the following met:
1+ painful ulcers
* Darkfield & serology negative for syphilis
* Negative HSV (ulcer exudate)
* Clinical presentation of genital ulcer + adenopathy”
Treatment:
“ Azithromycin, ceftriaxone, ciprofloxacin, erythromycin
* Sex partners should be examined & treated if sexual contact w pt 10 days preceding onset of symptoms”
Gram Neg Coccobacilli
Acinetobacter baumanii
”* Aerobe
*Non-motile
*Catalase +
*Oxidase neg
y-hemolytic”
Transmission: “ Soil/water
*ESKAPE pathogen”
Virulence Factors:
Disease: * VAP, UTIs, sepsis, meningitis
Diagnosis:
Treatment:
Gram Neg Zoonotic
Francisella tularensis
”* Aerobe
*Coccobacillus
*Non-motile
VERY small
* Difficult to culture”
Transmission: “ Rabbits or tick bite from rabbit
* Enters macrophages –> caseating granuloma”
Virulence Factors:
Disease: “Tularemia: form depends on portal of entry
*Ulceroglandular - skin lesion & LN
* Oculoglandular - eye & cervical LNs
*Glandular - LNs
Typhoidal - fever, sepsis
* Pneumonic - severe w sepsis
* Oropharyngeal/GI disease (after ingestion, RARE)”
Diagnosis: “ Serology
Culture (choc agar, but high risk of spread to lab personnel)”
Treatment: “ Streptomycin
* Gentamicin
* Doxycycline or cipro for milder infections”
Gram Neg Zoonotic
Brucella melitensis
”* Fac anaerobe
Coccobacillus
Non-motile
*Oxidase +
*Catalase +”
Transmission: “ Sheep, goats, etc. (shed in milk, urine, feces)
* Inhalation or ingestion of unpasteurized milk”
Virulence Factors:
Disease: “Brucellosis:
* Enters LNs/bloodstream
* Chronic granulomatous infection (can survive for long periods in liver, spleen, bone marrow, LNs)
* Undulant fevers, enlarged LNs, hepatitis, osteomyelitis, endocarditis (rare)
* Chronic Infection: fatigue, intermittent fever/ symptoms”
Diagnosis: “Blood culture (bone marrow or LN)
* Serology: IgM in acute, IgG/IgA in chronic”
Treatment: * Doxycycline, streptomycin or TMP-SMX
Gram Neg Zoonotic
Chlamydia psittaci
”* Aerobe
*Coccoid
*Non-motile
*Ob Intracellular”
Transmission: * Parrots & other birds
Virulence Factors:
Disease: “Psittacosis:
* Atypical interstitial pneumonia
*Aseptic meningitis & sepsis”
Diagnosis: * Serology: CF testing of acute and convalescent sera
Treatment: * Doxycycline or macrolide
Gram Neg Zoonotic
Bartonella henselae
”* Aerobe
Coccobacillus
Non-motile
*Oxidase neg”
Transmission: “ Cats & fleas
* OI: HIV < 200”
Virulence Factors:
Disease: “ Cat scratch disease: regional lymphadenopathy with dissemination possible to liver, spleen, CNS
*Bacillary angiomatosis in immunocompromised; vascular proliferative nodules in skin, liver or spleen
* Bacteremia & endocarditis
*B. quintana: Transmitted by lice, no animal reservoir, trench fever & infection in HIV pts (bacillary angiomatosis, bacteremia, endocarditis)
B. bacciliformis: Andes/S America, transmitted via sandfly bite; causes fever, hemolytic anemia w cutaneous nodules that can persist for yrs”
Diagnosis: “Blood culture (endocarditis, may be + w BA)
*Culture skin/LN (BA)
*Serology (cat scratch)”
Treatment:
* Doxycycline or macrolide (endocarditis or BA)
Gram Neg Zoonotic
Coxiella burnetti
”* Ob intracellular
* Microaerophilic
*Coccobacillus
Small
* Rickettsia”
Transmission: “ Many animals (lots in placenta & urine) or ingestion of unpasteurized dairy
* Persists in soil”
Virulence Factors:
Disease: “Q fever:
*Acute: atypical pneumonia, fever, HA, hepatitis
Chronic: culture neg endocarditis, osteomyelitis”
Diagnosis: “PCR (early illness)
Serology (>1 wk): IgG”
Treatment: “ Acute: tetracyclines
* Chronic: Rifampin + Doxycycline or TMP-SMX”
Gram Neg Zoonotic
Escherichia coli
”* LF
Fac anaerobe
* Motile
* Oxidase neg”
Transmission: “ Lower intestine (can infect newborn)
* Fecal oral transmission”
Virulence Factors:
Disease: “* Enterohemorrhagic (EHEC): shiga-like toxin; bloody diarrhea; acute renal failure, anemia w hemolysis, thrombocytopenia (HUS)
- O157:H7 most common (associated with beef)
* Enterotoxigenic (ETEC): Heat stable/labile toxins increase fluid secretion into gut –> water diarrhea (““Traveler’s diarrhea””)
*Enteropathogenic (EPEC): Type III secretion system to inject effector proteins into epithelial cells; infantile diarrhea
*Enteroaggregative (EAEC): Plasmid encoded toxin (Pet), heat stable toxin (EAST1), shigella enterotoxin 1 (ShET1); watery diarrhea (acute or persistent)
*Enteroinvasive: Attach in lg intestine and invade mucosal cells causing diarrhea that may contain blood & mucus (7-10 days); self limiting
*Uropathogenic (UPEC): a-toxin & hemolysin; UTIs
Neonatal Infection:
*Bacteremia and/or meningitis (K1 capsular antigen strain)
* Risk factors: intrapartum infection, maternal Abx use, GA < 37 wk, low BW
*Galactosemia, fetal hypoxia, GI/GU abnormalities, detects in skin/mucosal surfaces (myelomeningocele)”
Diagnosis: *EHEC: Detection of toxin in stool culture
Treatment: *No Abx
Gram Neg Rods
Klebsiella pneumoniae
”* Fac anaerobe
* Non-motile
*LF
*Oxidase neg
Catalase +
* Capsule
* Mucoid colonies”
Transmission: “Oral, skin, intestinal microbiome
* Soil
*ESKAPE pathogen”
Virulence Factors:
Disease: * UTIs, sepsis, surgical wound site infections
Diagnosis:
Treatment:
Gram Neg Rods
Klebsiella granulomatis
”* Intracellular
* Difficult to culture
*Donovan bodies”
Transmission: * Endemic to tropical & developing areas
Virulence Factors:
Disease: “Granuloma Inguinale (Donovanosis): PAINLESS, slowly progressive ulcers on genitals or perineum without regional lymphadenopathy
* Subcutaneous granulomas (pseudouboes)
* Highly vascular lesions that bleed easily
*Can present as hypertrophic, necrotic or sclerotic
*Extragenital extension to pelvis, intra-abdominal organs, bones, mouth”
Diagnosis: * Visualization of Donovan bodies on crush specimen or biopsy
Treatment: *Azithromycin, doxcycline, cipro, erythro, TMP-SMX for at least 3 wk
Gram Neg Rods
Enterobacter species
”* Fac anaerobe
* Motile
*LF
Oxidase neg
* Catalase +”
Transmission: “ Intestinal micrbiome
* Soil, water, sewage
*ESKAPE pathogen”
Virulence Factors:
Disease: * eye/skin infections, meningitis, bacteremia, pneumonia, UTIs
Diagnosis:
Treatment:
Gram Neg Rods
Serratia marcescens
“*Red pigment
* Fac anaerobe
* Motile
*LF (slowly)
*Oxidase neg
catalase +”
Transmission: “ Opportunistic
* Showers/toilets”
Virulence Factors:
Disease: *Bacteremia, UTIs, surgical wound infections, meningitis
Diagnosis:
Treatment:
Gram Neg Rods
Pseudomonas aeruginosa
“Non LF
Aerobe
*Motile
*Capsule
*Oxidase +
*Catalase +
*Blue-green color
*Grape odor”
Transmission: “ Environment
* Skin flora
* ESKAPE pathogen”
Virulence Factors:
Disease: “ Immunocompromised, severe burns, CF pts
*Inflammation (lungs, kidney, skin, etc) & sepsis
*Chronic infections present in biofilms (difficult to treat)”
Diagnosis: *Stool culture
Treatment: fluoroquinolones
Gram Neg Rods
Shigella dysenteriae
”* Non LF
*Fac anaerobe
*Non-motile
*Oxidase neg
* No SH2
*Low infectious dose”
Transmission: “*Fecal oral
Daycare outbreaks common”
Virulence Factors: * Shiga toxin (A-B)
Disease: “ Shigellosis: bloody diarrhea, fever & abdominal pain (S sonnei causes watery diarrhea)
* Hemolytic Uremic Syndrome: thrombocytopenia, anemia, renal failure”
Diagnosis:
Treatment:
Gram Neg Rods
Shigella sonnei
”* Non LF
*Fac anaerobe
*Non-motile
*Oxidase neg
* No SH2
*Low infectious dose”
Transmission: “*Fecal oral
*Daycare outbreaks common”
Virulence Factors: * Shiga toxin (A-B)
Disease: * Food poisoning: watery diarrhea
Diagnosis: *Stool culture
Treatment:
Gram Neg Rods
Yersinia enterocolitica
”* Aerobe
*Non LF
*Motile
*catalase +
*Oxidase -
Urease +
* Safety pin shape
* No SH2”
Transmission: “Pigs, undercooked meat
Contaminated water, milk, meat
* More common in colder climates”
Virulence Factors:
Disease: “ Acute gastroenteritis
*Yersinosis: fever, abdominal pain, diarrhea (16-48 hr after ingestion)
- diarrhea more in younger & may be absent in older
- Large mesenteric LN can develop
- mimics appendicitis”
Diagnosis:
Treatment:
Gram Neg Rods
Yersinia pestis (Plague)
”* Fac anaerobe
*Non-motile
*Catalase +
*Capsule
* No SH2
Safety pin/bipolar”
Transmission: “Rodents (reservoir)
* Transmitted via fleas”
Virulence Factors: * Type III secretion system
Disease: “Plague
* Septicemia: fever, hypotension
*Bubonic: fever, swollen axillary/groin LNs, followed by generalized spread & multisystem illness
*Pneumonia: severe bronchopneumonia
* High mortality without tx”
Diagnosis: Stain of LN aspirate or sputum (Giemsa, gram)
Treatment: “ Streptomycin
*Doxycycline”
- Vaccine exists
Gram Neg Rods
Salmonella enterica
”* Fac anaerobe
*Motile
* Non LF
*Oxidase neg
*Produces SH2
*Encapsulated
Lot of serotypes”
Transmission: “ Fecal oral
*Undercooked meat, milk, eggs (dairy/poultry), pet reptiles (turtles)
Incubation period = 36-72 hr”
Virulence Factors:
Disease: “ Salmonellosis: Gastroenteritis with fever, N/V, bloody/inflammatory diarrhea
* Invasive disease in immunocompromised: septicemia, osteomyelitis, mycotic aneurysms
* Typhi serovar –> typhoid fever”
Diagnosis: * Culture from stool
Treatment: * Supportive
Gram Neg Rods
Salmonella typhi
”* Fac anaerobe
*Motile
* Non LF
*Oxidase neg
*Produces SH2
*Encapsulated
Lot of serotypes”
Transmission: “ Poor sanitation & contaminated water
*Chronically carried in human gallbladder”
Virulence Factors:
Disease: “Typhoid Fever (5-21 d incubation) differs from typhus which is vector-borne (lice)
*Week 1: Step-wise fever & relative bacteremia
Week 2: Bradycardia (unusual w fever), abdominal pain, rose spots (pea soup diarrhea?)
* Week 3: hepatosplenomegaly, intestinal bleed/perf, sepsis”
Diagnosis: * Blood, stool or bone marrow culture
Treatment: “Fluoroquinoones, cephalosporin or azithromycin
*Susceptibility testing”
“PPx pre-travel:
*Live vaccine 1 wk prior (boost 5 yr)
*Inactivated vaccine 2 wk prior (boost 2 yr)”
Gram Neg Rods
Proteus species
”* Fac anaerobe
*Motile
*non LF
*Oxidase neg
*Urease +
*Produces SH2
Bulls eye/swarms”
Transmission: “ Decomposing animals, sewage, manure soil
GI microbiome”
Virulence Factors:
Disease: “ Mirabalis: Second most common cause of UTIs
* Vulgaris: Wound infections, pneuomnia, septicemia”
Diagnosis:
Treatment:
Gram Neg Rods
Vibrio cholera
“*Fac anaerobe
*Motile
*Oxidase +
Catalase +
* 3% NaCl”
Transmission: “ Contaminated water
*Thailand?”
Virulence Factors: *Cholera toxin (A-B): constituitively activates cAMP –> increased Cl- loss
Disease: “Cholera: LARGE volume of watery diarrhea –>
*Dehydration, acidosis, hypotension (indicates severe vol loss), profound shock, weight loss
*Greater volume loss than with ETEC”
Diagnosis: *Culture
Treatment: *Supportive tx (oral rehydration)
* Vaxchora: live oral vaccine for 18-64 yo traveling to high risk area
Gram Neg Curved Rods
Vibrio vulnificus
6% NaCl
Transmission: “Marine environments
Shellfish/oysters”
Virulence Factors: * Cytolysin, hemolysin, MARTX toxin
Disease: “ Acute gastroenteritis, necrotizing wound infections, invasive species (immunocompromised)
* Systemic illness in those w liver disease or iron storage disorder; Fever, hypotension, bullous skin lesions”
Diagnosis:
Treatment: “* Surgery
*Tetracycline”
Gram Neg Curved Rods
Vibrio parahaemolyticus
10% NaCl
Transmission: “Salt water
* fecal oral
*ingestion of undercooked/raw seafood/oysters”
Virulence Factors: Kanagawa hemolysin
Disease: “ Watery or bloody diarrhea with vomiting & fever
Diagnosis:
Treatment:
Gram Neg Curved Rods
Helicobacter pylori
”* Microaerophile
* Motile
*catalase +
* Oxidase +
urease +”
Transmission: “GI microbiome
* infections common in low SEC”
Virulence Factors:
Disease: * Gastritis, peptic/gastric ulcers
Diagnosis:
Treatment:
Gram Neg Curved Rods
Campylobacter jejuni
”* Microaerophile
* Motile
catalase +
* Oxidase +
Grows well at 42”
Transmission: “Chickens & cattle, unpasteurized milk
* Household pets can become infected”
Virulence Factors:
Disease: “ Most common cause of gastroenteritis in the world
*Linked to development of reactive arthritis & Guillian-Barre syndrome (autoimmune attack on nerves)”
Diagnosis:
Treatment:
Gram Neg Curved Rods
Borrelia burgdorferi
”* Microaerophile
*No LPS
* Motile
Survives w/o Fe
* Spirochete”
Transmission: “ Ixodes tick from white footed mouse (reservoir)
* Tick must be attached for 48+ h
*Nymphs/adults spread disease
* NE/central US”
Virulence Factors:
Disease: “Lyme disease
*1 (early localized): erythema migrans (not painful or pruritic)
2 (early disseminated): neurologic Bell’s palsy, carditis
* 3 (late): intermittent/persistent arthritis”
Diagnosis: “ If no erythema migrans, serum lyme Ab
if positive, western blot”
Treatment: “ Early: doxycycline (amoxicillin, cefuroxime)
* Heart block/arthritis: IV ceftriaxone”
Gram neg spirochetes
Leptospira interrogans
”* Aerobe
Motile
* 3 mo to grow
* Spirochete”
Transmission: “ Infects dogs, rates, mice
* Transmitted via urine/wet environment”
Virulence Factors:
Disease: “*Leptospirosis: flu-like symptoms, hepatitis, jaundice, renal failure, aseptic meningitis, conjunctival or scleral hemorrhage (biphasic)
Weil’s Disease: severe w hemorrhage, kidney & liver failure”
Diagnosis: “Bacteria can be isolated from blood, CSF, urine
*PCR
* Serology: agglutinating Ab”
Treatment: * Penicillin or doxycycline if started early in course
Gram neg spirochetes
Treponema pallidum (Syphilis)
”* Microaerophile
No LPS
Motile
*Cannot be cultured
* Slow growth rate”
Transmission: “STI or congenital
* Incubation period = 3-90 days (med 3 wk)”
Virulence Factors:
Disease: “ Primary: single chancre that heals within 3-6 wk (painful w secondary infection), reg lymphadenopathy
*Secondary: (2-6 mo after primary infection or 2-10 wk after primary chancre) generalized lymphadenopathy, iritis, optic neuritis, uveitis, recurrent eruptions, maculopapular rash, condyloma lata
* Latent: Positive Ab test, but no clinical symptoms
- Early (< 1 yr): infectious, relapse can occur
- Late (>1 yr): resistance to reinfection, but can pass on to fetus or via transfused blood
* Tertiary/Late: inflammatory disease that can affect any organ 1-20 yr after initial infection; NOT infectious
- CV: Aneurysm of ascending aorta
- Gummatous: gummas form
- Leutic periostitis: inflammation of periosteum
*Early Neurosyphilis: first year after infection; HA, confusion, stiff neck, impaired vision, meningovascular
* Late Neurosyphilis: Decades later; paresis (loss of voluntary movement), dementia, tabes dorsalis, incontinence”
Diagnosis: “Direct Visualization
* Darkfield microscopy
* Immunofluorescent stain of lesions (not oral, naturally occuring bacteria can cause false pos)
Serology
* RPR (non-treponemal)
* VDRL: Measures IgM/IgG against Ag complex; Ab titers correlate with disease activity (non-treponemal)
* FTA-Abs/TP-PA: measures Ab against T pallidum Ag; used to verify non-trep tests; pts usually remain pos for life”
Treatment:
“*Penicillin (IV form to treat neurosyphilis)
* Doxycycline (if allergic to penicillin)
Tx of partner
*Within 90 days of diagnosis: tx with penicillin even w neg result (same w late latent disease but high titer in partner)
*> 90 days: no tx with neg result
* Long term partners of those with late latent: evaluate serologically & clinically
F/U
*Titers should show 4 fold decrease in 6-12 mo”
Gram neg spirochetes
Chlamydophilia pneumoniae
”* Aerobe
*No peptidoglycan
*Non-motile
*Ob intracellular
* Giemsa stain”
Transmission: Droplet transmission
Virulence Factors:
Disease: “ Atypical pneumonia
* Sore throat, laryngitis, headache”
Diagnosis:
Treatment:
Gram indeterminant
Mycoplasma pneumoniae
”* Smallest
*Intracellular
*No cell wall
*Related to GP
* Fried egg on culture”
Transmission: *Droplet transmission
Virulence Factors: CARDS toxin (CA resp distress syndrome)
Disease: “CARDS toxin causes inflammation & airway destruction
* Atypical walking pneumonia
* Sore throat, ear ache, headache”
Diagnosis:
Treatment:
Gram indeterminant
Legionella pneumophila
”* Aerobe
*Coccobacillus
*Motile
*catalase +
Reduced LPS
* Dieterle stain”
Transmission: “ Freshwater
*Amoeba (host)
*Aerosol transmission (A/C)”
Virulence Factors:
Disease: * Legionnaire’s Disease: severe form of atypical pneumonia with myalgia, headache, high fever, dry cough, chills, pleuritic chest pain, vomiting, diarrhea, confusion & delirium
Diagnosis:
Treatment: macrolides (azithromycin and clarithromycin) and fluoroquinolones (levofloxacin)
Gram indeterminant
Chlamydia trachomatis
”* Aerobe
*No peptidoglycan
*Non-motile
Ob intracellular
* Giemsa stain”
Transmission:
Virulence Factors:
Disease: “ Most common cause of infectious blindness (trachoma) & bacteria STI
*GU symptoms: discharge, bleeding, itchiness, painful urination
* Ocular symptoms: redness, swelling, eye discharge, conjunctivitis
* Complications:PID, ectopic pregnancy, infertility
Lymphogranuloma Venereum (LGV): L1, L2, L3
*Self-limited papule/ulcer
* Inguinal or femoral lymphadenopathy (unilateral)
* Rectal exposure can result in proctocolitis
- Urethritis: discharge, dysuria, pruritus
Cervicitis: discharge, intermenstrual bleeding”
Diagnosis: “ Genital/LN specimens can be cultured, direct immunofluorescence, NAAT
Serology”
Treatment: “LGV: Doxycycline - Urethritis:Azithromycin or doxycycline
*Pregnant: Azithromycin only”
Gram indeterminant
Rickettsiae
”* Ob intracellular
*Gram neg
* little peptidoglycan (stains poorly)
*Pleiomorphic
* cannot be cultured in artificial media”
Transmission: Incubation period = 7-14d
Virulence Factors:
Disease: “R rickettsii: RMSF
* R akari: Rickettsialpox
*R prowazekii: EPIdemic typhus
* R typhus: lice (vector) ENdemic typhus
*Orientia tsutsugamushi: Scrub typhus
Main symptoms: fever, rash, HA”
Diagnosis: *Ab detection
Treatment: *Doxycycline
- Typhoid Vaccine: inactivated injection OR oral live attenuated
Gram indeterminant
Rickettsiae ricketsii
Transmission:”* Dermacentor tick or lone star tick (must be on person for 6+ hrs)
* Most common in South/Central US
* Most cases Apr-Oct
* Incubation period = 2-14d”
Virulence Factors: * OmpA: outer membrane protein that helps it adhere to endothelial cells causing leaky blood vessels & disease
Disease: “Rocky Mtn Spotted Fever:
Prodrome: Fever, nausea, vomiting, HA, malaise, photophobia
* Bacteria replicate in endothelial cells of vessels, disseminating in blood -> thrombosis & capillary leak -> edema & petechia
* Rash with blanching macules/papules on wrists & ankles -> petechia (2-5 days post-exposure); spreads centrally (spares face)
* Complications: renal failure, pulmonary failure, neuro manifestations, cardiac abnormalities, rapidly fatal”
Diagnosis: “Ab detection
*PCR on skin biopsy”
Treatment: * Doxycycline (do NOT wait for definitive diagnosis or rash bc can be rapidly fatal; not contraindicated for kids under emergent settings)
Gram indeterminant
Rickettsiae akari
Transmission:“*Rodents –> mites
* Urban areas”
Virulence Factors:
Disease: “Rickettsialpox (biphasic)
* Papule forms into eschar (1 wk) –>
*Systemic spread causing high fever, severe HA, chills, sweats, myalgia, photophobia –>
*Papulovesicular rash with vesicles & crust (2-3 d)”
Diagnosis:
Treatment: * Doxycycline
Gram indeterminant
Anaplasma phagocytophilum
Transmission: “* Ixodes deer tick
* Infects granulocytes
* NE/midwest”
Virulence Factors:
Disease: “Human Granulocytic Anaplasmosis (HGA): Fever, myalgia, HA, malaise
*Rash & CNS involvement are RARE
*Transaminitis, leukopenia, thrombocytopenia (more severe)”
Diagnosis:
Treatment: * Doxycycline
Gram indeterminant
Ehrlichia chaffeensis
Transmission: “* Lone star tick
*Infects monocytes
*SE/mid-Atlantic/midwest”
Virulence Factors:
Disease: “Human Monocytic Ehrlichosis (HME): Fever, myalgia, occasional rash
*CNS involvement more severe
* Transaminitis, leukopenia, thrombocytopenia (less severe)”
Diagnosis:
Treatment: * Doxycycline
Gram indeterminant
Mycobacterium avum (MAC, NTB)
”* Acid fast
*Rod shaped
*Non-motile
catalase +”
Transmission: “Inhalation or ingestion
OI: CD4 < 50”
Virulence Factors:
Disease: “ Lung infection similar to TB symptoms
* Insidious onset of fever, weight loss, night sweats, diarrhea (several wks)
Disseminates into bone marrow (anemia, neutropenia, elevated alkaline phosphatase-high turnover of bone marrow) & LNs (lymphadenopathy, hepatosplenomegaly)”
Diagnosis: “ Blood culture (takes up to 8 wk to grow)
* Biopsy affected organ with culture & pathology”
Treatment: *2-3 drug combo including at least 1 macrolide (clarithromycin)
Acid Fast Bacteria
Mycobacterium laprae (NTB)
”* Acid fast
*Rod shaped
*Non-motile
*Ob intracellular”
Transmission:
Virulence Factors:
Disease: * Leprosy: chronic disease that damages peripheral nerves & targets skin, eyes, nose, muscles; skin sores, nerve damage, muscle weakness (can take up to 40 yrs to present w symptoms)
Diagnosis:
Treatment:
Acid Fast Bacteria
Mycobacterium tuberculosis
”* Acid fast
Transmission: *OI: HIV pts at any CD4 count
Virulence Factors:
Disease: “Pulmonary TB: cavitary
Miliary TB: hematogenous seeding of lung tissue
- bone marrow/LN: pancytopenia
- brain, bone, peritoneum, pericardium, etc.”
Diagnosis:
Treatment:
Acid Fast Bacteria
