Brucella Six species of Brucella B.melitensis, B.abortus, B.suis, B.canis Sir David Bruce...
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Transcript of Brucella Six species of Brucella B.melitensis, B.abortus, B.suis, B.canis Sir David Bruce...
BrucellaBrucella
Six species of Six species of BrucellaBrucella B.melitensis, B.abortus, B.suis, B.melitensis, B.abortus, B.suis,
B.canisB.canis Sir David Bruce Sir David Bruce [brucellosis][brucellosis], ,
Bernhard Bang Bernhard Bang [Bang's disease][Bang's disease] Undulant fever, Malta fever, Undulant fever, Malta fever,
Mediterranean remittent fever Mediterranean remittent fever
BrucellaBrucella
small (0.5 × 0.6 to 1.5 μm), nonmotile, small (0.5 × 0.6 to 1.5 μm), nonmotile, nonencapsulated, gram-negative nonencapsulated, gram-negative coccobacilli coccobacilli
grows slowly grows slowly strictly aerobic strictly aerobic does not ferment carbohydrates does not ferment carbohydrates
BrucellaBrucella
endotoxin is less toxic endotoxin is less toxic intracellular parasite intracellular parasite the organisms are phagocytosed by the organisms are phagocytosed by
macrophages and monocytes macrophages and monocytes phagocytosed bacteria are carried to the phagocytosed bacteria are carried to the
spleen, liver, bone marrow, lymph nodesspleen, liver, bone marrow, lymph nodes the bacteria secrete proteins that induce the bacteria secrete proteins that induce
granuloma formation granuloma formation
BrucellaBrucella
Intracellular pathogen that is resistant to Intracellular pathogen that is resistant to killing in serum and by phagocytes killing in serum and by phagocytes
Smooth colonies associated with Smooth colonies associated with virulence virulence
goats and sheep goats and sheep (Brucella melitensis)(Brucella melitensis) cattle cattle (Brucella abortus)(Brucella abortus) swine (Brucella suis)swine (Brucella suis) dogs, foxes (Brucella canis)dogs, foxes (Brucella canis)
BrucellaBrucella
Latin America, Africa, the Mediterranean Latin America, Africa, the Mediterranean basin, the Middle East, and Western Asia basin, the Middle East, and Western Asia
More than 500,000 documented cases More than 500,000 documented cases Vaccination of animals Vaccination of animals Direct contact with the organism (e.g., a Direct contact with the organism (e.g., a
laboratory exposure), ingestion (e.g., laboratory exposure), ingestion (e.g., consumption of contaminated food consumption of contaminated food products), or inhalation products), or inhalation
BrucellaBrucella
BrucellaBrucella causes mild or asymptomatic causes mild or asymptomatic disease in the natural host disease in the natural host
Erythritol (breast, uterus, placenta)Erythritol (breast, uterus, placenta) Brucellae are shed in high numbers in Brucellae are shed in high numbers in
milk, urine, and birth products milk, urine, and birth products B.melitensisB.melitensis is the most common spp is the most common spp
BrucellaBrucella-Clinical diseases-Clinical diseases
Brucellosis:Brucellosis: Initial nonspecific Initial nonspecific symptoms of malaise, chills, sweats, symptoms of malaise, chills, sweats, fatigue, myalgias, weight loss, fatigue, myalgias, weight loss, arthralgias, and fever; can be intermittent arthralgias, and fever; can be intermittent (undulant fever)(undulant fever)
can progress to systemic involvement can progress to systemic involvement (gastrointestinal tract, bones or joints, (gastrointestinal tract, bones or joints, respiratory tract, other organs) respiratory tract, other organs)
BrucellaBrucella-Clinical diseases-Clinical diseases
Incubation period 1-6 weeksIncubation period 1-6 weeks Fever rises in the afternoonFever rises in the afternoon Falling at night by drenching sweatFalling at night by drenching sweat Lymph nodes enlarge, SMLymph nodes enlarge, SM Hepatitis, steomyelitisHepatitis, steomyelitis Generalized infection subsides usuallyGeneralized infection subsides usually A chronic state may occurA chronic state may occur
BrucellaBrucella-Diagnosis-Diagnosis
grow slowly grow slowly most enriched blood agars most enriched blood agars microscopic and colonial morphology microscopic and colonial morphology positive oxidase and urease reactions positive oxidase and urease reactions B. abortusB. abortus and and B. melitensis, B. abortus,B. melitensis, B. abortus,
and and B. suisB. suis will react with antisera will react with antisera prepared against prepared against B. abortusB. abortus or or B. B. melitensismelitensis
Brucella-SerologyBrucella-Serology
IgM, IgG, IgAIgM, IgG, IgA Four fold increase or 1/80 indicate active Four fold increase or 1/80 indicate active
infection infection If agglutination negative “blocking If agglutination negative “blocking
antibodies” add antihumanglobulinantibodies” add antihumanglobulin
BrucellaBrucella-Treatment-Treatment
Doxycycline+rifampinDoxycycline+rifampin Trimethoprim-sulfamethoxazole for Trimethoprim-sulfamethoxazole for
pregnant women and for children pregnant women and for children younger than 8 years younger than 8 years
6 weeks or longer 6 weeks or longer Fluoroquinolones, macrolides, penicillins, Fluoroquinolones, macrolides, penicillins,
and cephalosporins either ineffective or and cephalosporins either ineffective or have unpredictable activity. have unpredictable activity.
FrancisellaFrancisella
Two species, Two species, Francisella tularensisFrancisella tularensis and and Francisella philomiragiaFrancisella philomiragia
the causative agent of the causative agent of tularemiatularemia (also (also called called glandular fever, rabbit fever, tick glandular fever, rabbit fever, tick fever,fever, and and deer fly feverdeer fly fever) in animals and ) in animals and humans humans
very small (0.2 × 0.2 to 0.7 μm), faintly very small (0.2 × 0.2 to 0.7 μm), faintly staining, gram-negative coccobacillus staining, gram-negative coccobacillus
nonmotile nonmotile thin lipid capsule thin lipid capsule fastidious requirements (most strains fastidious requirements (most strains
require cysteine for growth)require cysteine for growth) strictly aerobic and requires 3 or more strictly aerobic and requires 3 or more
days days
Gram stain of Gram stain of Francisella tularensisFrancisella tularensis isolated in culture; note the extremely small coccobacilli isolated in culture; note the extremely small coccobacilli
Antiphagocytic capsule Antiphagocytic capsule Intracellular pathogen resistant to killing in Intracellular pathogen resistant to killing in
serum and by phagocytes serum and by phagocytes Wild mammals, domestic animals, birds, fish, Wild mammals, domestic animals, birds, fish,
and blood-sucking arthropods are reservoirs; and blood-sucking arthropods are reservoirs; rabbits and hard ticks are most common hosts; rabbits and hard ticks are most common hosts; humans are accidental hosts humans are accidental hosts
Worldwide distribution Worldwide distribution The infectious dose is very small The infectious dose is very small
Human tularemia is acquired most often from Human tularemia is acquired most often from the bite of an infected "hard-shell" tick (e.g., the bite of an infected "hard-shell" tick (e.g., Ixodes, Dermacentor, AmbylommaIxodes, Dermacentor, Ambylomma spp.) spp.)
or from contact with an infected animal or or from contact with an infected animal or domestic pet domestic pet
F. tularensisF. tularensis requires as few as 10 organisms requires as few as 10 organisms when exposure is by an arthropod bite when exposure is by an arthropod bite
Ulceroglandular tularemia:Ulceroglandular tularemia: Painful papule develops Painful papule develops at the site of inoculation that progresses to ulceration; at the site of inoculation that progresses to ulceration; localized lymphadenopathy localized lymphadenopathy
Oculoglandular tularemia:Oculoglandular tularemia: Following inoculation into Following inoculation into the eye (e.g., rubbing eye with a contaminated finger), the eye (e.g., rubbing eye with a contaminated finger), painful conjunctivitis develops with regional painful conjunctivitis develops with regional lymphadenopathy lymphadenopathy
Pneumonic tularemia:Pneumonic tularemia: Pneumonitis with signs of Pneumonitis with signs of sepsis develops rapidly after exposure to contaminated sepsis develops rapidly after exposure to contaminated aerosols; high mortality unless promptly diagnosed and aerosols; high mortality unless promptly diagnosed and treated treated
Ulceroglandular tularemia is the most common Ulceroglandular tularemia is the most common manifestation manifestation
FrancisellaFrancisella-Diagnosis-Diagnosis
F. tularensisF. tularensis are hazardous for both the physician and are hazardous for both the physician and the laboratory worker the laboratory worker
Microscopy is insensitive due yo small size and faintly Microscopy is insensitive due yo small size and faintly stainingstaining
Fluorescein-labeled antibodiesFluorescein-labeled antibodies PCRPCR F. tularensisF. tularensis can grow on chocolate agar or buffered can grow on chocolate agar or buffered
charcoal yeast extract (BCYE) agar, media charcoal yeast extract (BCYE) agar, media supplemented with cysteine supplemented with cysteine
a fourfold or greater increase in the titer of antibodies a fourfold or greater increase in the titer of antibodies during the illness or a single titer of 1:160 or greater during the illness or a single titer of 1:160 or greater