Other Zoonotic Bact. I/II Flashcards
Shape of Leptospira?
small, thin, spiral shaped (question mark shaped)
Where do we find Leptospira and where does it go in the body?
endemic in tropical regions (Hawaii); associated with water sports/ swimming
travels through blood and infects various organs esp. kidney (high CK/ azotemia) and liver
Discuss the lab findings of Leptospira
Lab: Can be grown aerobically in appropriate media
Symptoms of Leptospira
Sx: Acute febrile illness with conjunctival suffusion (reddening with no pus) that may progress to jaundice and renal failure (Weil’s disease), pulmonary hemorrhage or meningitis.
Who are at risk for Leptospira
At risk: animal urine–> contaminated water→ Soldiers wading in water/streams during field exercises
Source of Lyme Disease? Discuss the life cycle of this thing,
Source: hard ticks (ixodes scapularis family) type: Deer ticks
Life cycle: White footed mouse= reservoir for larvae; white tailed deer = obligatory host for adult form (deer immune)
Who is at risk for Lyme Disease?
Risk: NE and midwest USA– Most common arthropod-borne infection in the U.S.
Nymph stage of the tick in the months of May - July is the most contagious.
How do we diagnose Lyme Disease
Dx: blood culture and PCR (Synovial fluid if they have arthritis), ELISA/western blot, Wright stain, Giemsa stain
Discuss the symptoms of Lyme Disease
Stage 1: 2-7 days: (localized infection) bull’s eye rash (w/in a month of bite), flu sx (fever+chills)
(Local spread) erythema migrans
Stage 2: weeks to months later:(disseminated infection) bilateral bell’s palsy, heart block caused by myocarditis, erythema migrans in other locations
Stage 3: months to years: (persistent infection) lyme encephalopathy (memory problems, meningitis or other CNS sx), migratory polyarthritis starting w/ large joints (like knee), acrodermatitis
FACE: facial nerve palsy, arthritis, cardiac block, erythema migrans
Lyme’s Disease is similar to STARI. What is STARI all about?
**similar to: STARI - Southern Tick-Associated Rash Illness - lyme-disease like rash seen in people residing in southeastern and south-central US; cause =the lone-star tick (Amblyomma americanum), but bacterial agent is unknown
Treatment of Lyme Disease
Tx: Doxycycline (stage 1), Ceftriaxone (stage 3)
Discuss the symptoms of Relapsing fevers
Sx: Relapsing fever - recurrent episodes of fever x3-5 days (+HA, myalgia, vomiting) separated by asymptomatic intervals.
incubation period ~6 days
initially: sudden chills, high fever, tachycardia, delirium, red macular rash on trunk and extremities (erythema multiforme)
relapse: fever, arthralgia, jaundice
can lead to: hepatosplenomegaly, myocarditis, heart failure
Louse born vs. Tick born relapsing fever
Louse(lice)-borne (Borrelia recurrentis)= transmitted from person to person with no animal reservoir (louse/lice is crushed on host and leaks Borrelia) = epidemic form
Tick-borne (Borrelia hermsii)= transmitted from animals to humans by soft ticks (Ornithodoros hermsi)= endemic form.
Who is at risk for Louse born vs. Tick born?
Louse: Risk:mountains in Africa/S. Ameria. war areas and refugee camps
Tick: Risk: western US in summer. Sleeping in rodent-infested cabins in the mountains
Treatment of Relapsing fever
Tx: doxy/ tetracycline or erythromycin
Discuss the lab and structure for Rickettsia
G(-) coccobacillus bacteria (ovoid shaped)
gram stains poorly (but can use Giemsa stain)
obligate intracellular (get NAD+ and CoA from eukaryotic cells for bacterial replication),
nonmotile (spread from cell to cell w/ actin polymerization), nonspore-forming
Discuss the symptoms of Ricketssia rickettsii
Rocky Mountain Spotted Fever
sx: spotted fever, n/v, red eyes, rash (small, flat pink macules on extremities)
later sx: rash becomes darker small spots and moves centrally
can lead to: renal failure, myalgia, skin necrosis, pneumonia, brain infarct, death
Pathogenesis of Ricketssia Rickettsii
patho: invades endothelial cells and induces cells to phagocytose more bacteria
Labs for RMSF (Rocky Mountain Spotted Fever)
labs: IgG or IgM antibodies on IF, PCR detects rickettiae DNA
Treatment for Rocky Mountain Spotted Fever
tx: doxycycline (side effect in children: teeth staining)
Talk about Rickettsialpox
Source: rodents → mites → humans
Sx:Rickettsialpox Rash like chicken pox (papulovesicular). Eschar at bite site
Seen in US
Discuss Rickettsia prowazeki
Source: body louse vector to squirrel reservoir
Sx: epidemic typhus
Not seen in US (seen in Somalia)
Discuss Rickettsia Typhi
Source: flea-borne vectors, rodent reservoir
Sx: endemic or murine typhus
Seen in the US and worldwide
Talk about Orienta Rickettsia
Source: mites, chiggers
Sx: scrub typhus
Not in US, in Vietnam
Talk about Anaplasmataceae:
G(-) small bacteria , intracellular (in cytoplasmic vacuoles of hematopoietic cells)
histo: morulae- basophilic and intracytoplasmic inclusions
What type of bacteria are Anaplasma phagocytophilum and where do they hide
G(-) small bacteria , intracellular (in granulocytes/neutrophils)
Discuss the source and transmission for Anaplasma phagocytophilum
Source: hard ticks (ixodes scapularis family) type: Deer ticks
cattle/sheep → ticks → humans
Discuss the symptoms for Anaplasma phagocytophilum
sx: similar to RMSF, but more abrupt fever, chills, HA, malaise,hemorrhagic gastroenteritis
Discuss the risk for Anaplasma Phagocytophilum and what it is associated with
risk: NE and mid-atlantic US
a/w: coinfection with lyme disease and babesiosis
Discuss the structure of Coxiella and the transmission of it
G(-) obligate intracellular (in phagolysosomes)
source: cattle/sheep → ticks → humans
spores spread through animal droppings: Spread to humans via aerosol transmission; often in farmers, veterinarians
Discuss the symptoms of Coxiella
sx: malaise, flu-sx, abrupt fever, profuse sweating, AMS, n/v/d, headache
can lead to: atypical pneumonia, ARDS, hepatitis, endocarditis
Discuss the symptoms of Coxiella
tx: cephalosporin (1st gen); often self limiting
Discuss the source and structure of Yersinia Pestis
Gm (-) rod, safety pin appearance
Source: flea vector, occurs naturally in southwestern US grasslands
Cycles through rodents (mainly prairie dogs) → domestic animals and humans (cats can transmit by resp. droplets)
Discuss the pathology of Yersinia Pestis and when we see outbreaks occur
Outbreak common in cool summers following wet winters.
Path: flea bites and regurgitates bacteria→ vesicular lesion→ phagocytosis by PMNs→ killed in PMNs or released→ can now resist further phagocytosis→ travel to lymphatics and localized to a lymph node (bubo) → stops here or disseminates
Discuss the symptoms of Yersinia Pestis
Sx: “black death” (acral gangrene), lymph node bubo, skin ulcers and eschar at bite site, pneumonia, septic shock, meningitis; systemic leading to organ abscess, DIC, necrosis
Virulence factors for Yersinia Pestis
Exotoxins
Yops (yersinia-associated outer proteins) secreted by
Type 3 secretion system: inhibit cytokine produce and phagocytosis
How do we diagnose and treat Yersinia Pestis
Dx: grows on McConkey agar, Wayson staining shows light blue bacilli with dark blue polar bodies
Tx: aminoglycosides (streptomycin) + tetracycline
Vaccine: killed vaccine
Discuss the structure of Tularemia
Gm (-) coccibacilli, facultative intracellular (grows in macrophages) -> depends on cell mediated immunity
Tularemia Source
Source: hard ticks (Ixodidae dermacentor), rabbits are main reservoir.
transmission: direct contact or aerosolized (terrorism threat)
Discuss symptoms of Tularemia
Sx: spectrum. general malaise, fever, HA
ulcers+glands: painful lesion at site of infection→ regional lymphadenopathy (granulomas with caseating necrosis of reticuloendothelial organs like lymph nodes)
eyes: conjunctiva infected
lungs: pneumonia
GI: typhoid fever sx
Discuss how we diagnose and treat Yersinia Pestis
Tx: aminoglycosides (streptomycin)
Dx: serum titers, culture (requires cysteine- chocolate agar or BCYE), faint gram stain, agglutination test
Discuss the structure of Brucella
G(-) small coccobacilli, facultative intracellular, non-encapsulated, flagellated, ability to survive in macrophages
Source of Brucella
source: no arthropod vector– contaminated foods (unpasteurized milk/cheese), direct infected animal contact (hogs, elk, moose), animal tissue high in erythritol
Who is at risk for Brucella
at risk: vets, hunters, meat-processing
targets RES organs (may or may not cause enlargement of these organs); causes cell lysis and spreads systemically; osteomyelitis
Symptoms of Brucella
sx: granulomas, bacteremia, undulating fever/chills/night sweats/weight loss. can lead to: hepatic lesions, arthritis, meningitis, endocarditis
Discuss the pathology of Brucella
Path: enter via mucous membranes/skin,GIT,inhalation→ eaten by PMN/macrophage→ lymph nodes→ replicate in macrophages→ phagocytic cells travel to reticuloendothelial system organs (spleen/liver/lymph nodes)–> either stops or forms granulomas with recurrent bacteremia
Discuss how we diagnose and treat Brucella
dx: serology
tx: doxycycline and rifampin
Discuss the source of Bartonella Henselae
immunocompetent pts→ cat-scratch fever
immunocompromised pts → bacillary angiomatosis (endothelial proliferation of raised red vascular lesions)
source: cats, ticks, fleas
Discuss the symptoms and diagnosis for Bartonella Henselae
sx: red, tender, swollen lymph node
diag: Warthin Starry stain (silver stain)
Discuss treatment for Bartonella Henselae
Tx: catch scratch is usually self limiting but can use azithromycin; bacillary angiomatosis: macrolides, doxycycline
What is Bartonella Quintana
trench fever
source: lice (body louse)
sx: 5 day fever, bacteremia
What is Bartonella Baciliformis
carrion’s disease
source: sand fly
sx:
- oroya fever (hemolytic anemia)
- verruga peruana
