Presentation on theme: "Zoonosis Francisella Brucella Yersinia. ZOONOSIS A disease, primarily of animals, which is transmitted to humans as a result of direct or indirect contact."— Presentation transcript:
Zoonosis Francisella Brucella Yersinia
ZOONOSIS A disease, primarily of animals, which is transmitted to humans as a result of direct or indirect contact with the infected animal population
Brucella: Overview Primarily a disease of animals.Primarily a disease of animals. Common where significant disease among domestic animals.Common where significant disease among domestic animals. Common names- Undulant fever, Malta fever, Mediterranean remittent fever.Common names- Undulant fever, Malta fever, Mediterranean remittent fever. Brucella can go through intact skin.Brucella can go through intact skin. Facultative intracellular bacteriaFacultative intracellular bacteria
Morphology & Physiology Small gram-negative coccobacillusSmall gram-negative coccobacillus Grows slowly (7 days), at 37 0 C.Grows slowly (7 days), at 37 0 C. On subculture, a minimum of 48 h growthOn subculture, a minimum of 48 h growth Aerobic growth on Chocolate agar and Sheep blood agarAerobic growth on Chocolate agar and Sheep blood agar Will not grow on MacConkey or Eosin methylene blue (EMB) agarWill not grow on MacConkey or Eosin methylene blue (EMB) agar
Morphology & Physiology Non-pigmented and non-hemolyticNon-pigmented and non-hemolytic Non-motileNon-motile Oxidase: positiveOxidase: positive Catalase: positiveCatalase: positive Urease: strongly positive, less than 2 hours. Some species within 5 minutes.Urease: strongly positive, less than 2 hours. Some species within 5 minutes.
Microscopic Characteristics Brucella spp.Brucella spp. –poorly staining –small gram-negative coccobacilli –seen mostly as single cells –appearing like “fine sand”
Brucella melitensis colonies A. Grows slowly on most standard laboratory media. Usually not visible at 24h. B. Pinpoint, smooth, translucent, non- hemolytic at 48h.
Public Health Aspects Brucella: Sources Brucellosis caused by 1 of 4 Brucella species:Brucellosis caused by 1 of 4 Brucella species: 1.B. abortus Some strains require 5% CO 2 on initial isolation.
2. B. melitenus Goats Sheep Camels
B. suis 3. B. suis
B. canis 4. B. canis
2 patient populations 1.Individuals who work with unvaccinated animals B. abortus and B. suisB. abortus and B. suis Infections result from:Infections result from: direct contactdirect contact inhalationinhalation 2.Individuals who ingest unpasteurized dairy products B. melitensis is the most common agentB. melitensis is the most common agent
Host Animal - Brucellosis Asymptomatic or mild disease.Asymptomatic or mild disease. Predilection for organs rich in erythritol (breast, uterus, placenta, epididymis).Predilection for organs rich in erythritol (breast, uterus, placenta, epididymis). Causes sterility, abortions or carrier state in non- human animals.Causes sterility, abortions or carrier state in non- human animals.
Human - Brucellosis Symptoms Acute Phase Advanced Disease Chronic Form
Pathogenesis mucosal epithelium Transported to lymph nodes, spleen, liver and bone marrow. Brucella
Pathogenesis Phagosome Lysozome X
Pathogenesis No exotoxinsNo exotoxins LPS does not activate the alternative complement pathwayLPS does not activate the alternative complement pathway Acute lymphadenitisAcute lymphadenitis Granulocyte production in lymphatic tissue, spleen, liver, bone marrow, lymph nodes and kidneys.Granulocyte production in lymphatic tissue, spleen, liver, bone marrow, lymph nodes and kidneys. A potential bioterrorist agentA potential bioterrorist agent
Diagnosis Symptoms and historySymptoms and history Serological agglutination testsSerological agglutination tests CultureCulture –Blood and bone marrow cultures –Spleen, liver, joint fluid or abscesses
Treatment Tetracycline, doxycycline, or trimethoprimsulfamethoxazole in combination and rifampin or gentamicin for 6 weeks to prevent reoccurring infection. Tetracycline, doxycycline, or trimethoprimsulfamethoxazole in combination and rifampin or gentamicin for 6 weeks to prevent reoccurring infection.
Tularemia: (Francisella tularensis) Gram stain
Tularemia: Overview Primary reservoir in USPrimary reservoir in US –Rabbits and muskrats Insect vectorsInsect vectors –Ticks Infection viaInfection via –Insect bites –Handling contaminated animal tissues –Inhalation of aerosols –Ingestion of contaminated food or water –Exposure in a laboratory setting
Tularemia: Overview Gram-negative coccobacilli.Gram-negative coccobacilli. Low infectious doseLow infectious dose Two subspecies of F. tularensis:Two subspecies of F. tularensis: –subspecies tularensis (type A) –subspecies holarctica (type B)
Morphology & Physiology Tiny gram-negative coccobacillusTiny gram-negative coccobacillus Nonmotile, encapsulatedNonmotile, encapsulated Aerobic slow growing (48 hours) CAerobic slow growing (48 hours) C Fastidious organism requires sulfhydryl (cysteine, IsoVitaleX) supplementation for growthFastidious organism requires sulfhydryl (cysteine, IsoVitaleX) supplementation for growth Grows wells onGrows wells on –Chocolate agar –Buffered charcoal yeast extract agar
Colony Characteristics After 48 hours incubationAfter 48 hours incubation ColoniesColonies –Very small – white to gray to bluish- gray Will not grow on MacConkey or EMB plates.Will not grow on MacConkey or EMB plates. F. tularensis on chocolate agar 48 hours growth.
Microscopic Characteristics Tiny, faintly staining, pleomorphic gram-negative rods ( mcm X mcm) are noted; cells are smaller than those of Haemophilus species.
Grows slowly at CGrows slowly at C Oxidase-negativeOxidase-negative Weakly catalase-positive (may be negative)Weakly catalase-positive (may be negative) Urea-negativeUrea-negative Nitrate-negativeNitrate-negative Non-motileNon-motile Beta-lactamase-positiveBeta-lactamase-positive Satellite or XV test-negative (unlike Haemophilus)Satellite or XV test-negative (unlike Haemophilus) Phenotypic Characteristics
Tularemia: Public Health Modes of humans infectionModes of humans infection Bite of infected flies, or ticksBite of infected flies, or ticks Handling contaminated animal tissues or fluidsHandling contaminated animal tissues or fluids Direct contact with or ingestion of contaminated water, food, or soilDirect contact with or ingestion of contaminated water, food, or soil Inhalation of infective aerosols (most likely BT route)Inhalation of infective aerosols (most likely BT route)
Endemic in USEndemic in US –Majority of cases occur May – September (tick exposure) or winter (hunters). –Most in rural areas. –Arkansas, Missouri and Oklahoma Tularemia: Public Health
Symptoms Incubation period: 3-5 days (range 1-21 days)Incubation period: 3-5 days (range 1-21 days) Clinical presentation can be divided into groupsClinical presentation can be divided into groups –Ulceroglandular (45-85%) /glandular (10% to 25%) –Typhoidal –Pneumonic –Oculoglandular –Oropharyngeal/Gastrointestinal Prominent lymphadenopathyProminent lymphadenopathy Recovery followed by permanent immunityRecovery followed by permanent immunity
Tularemia Clinical Types Clinical presentation based on the route of infection
Pneumonic tularemia Entry into lungs viaEntry into lungs via –Aerosols –hematogenous Severe atypical pneumoniaSevere atypical pneumonia Likely BT presentationLikely BT presentation
Facultative intracellular pathogenFacultative intracellular pathogen Capsule protects against complement killingCapsule protects against complement killing Macrophage uptakeMacrophage uptake –bacterial surface polysaccharides –serum complement –complement C3 receptors LPS - O antigenLPS - O antigen –prevents maturation of the phagosome multiply to high levels in cytosolmultiply to high levels in cytosol Bacterial release via apoptosisBacterial release via apoptosis
Diagnosis Symptoms & HistorySymptoms & History Direct staining of clinical specimens with a fluorescein-labeled antibodies.Direct staining of clinical specimens with a fluorescein-labeled antibodies. Serum antibody titers of 1:160 or greaterSerum antibody titers of 1:160 or greater Culture on cysteine-rich mediaCulture on cysteine-rich media Notify Laboratory personnel if you suspect Francisella since it is HIGLY INFECTIOUSNotify Laboratory personnel if you suspect Francisella since it is HIGLY INFECTIOUS
Treatment of Tularemia Prompt removal of ticks and insect repellent can prevent disease.Prompt removal of ticks and insect repellent can prevent disease. AntibioticsAntibiotics –Streptomycin is the drug of choice
Overview: 3 species cause human disease Yersinia pestisYersinia pestis Yersinia enterocolyticaYersinia enterocolytica Yersinia pseudotuberculosisYersinia pseudotuberculosis
Overview: Plague Yersinia pestis; a gram-negative bacterium.Yersinia pestis; a gram-negative bacterium. Three forms of clinical illness; Three forms of clinical illness; –Bubonic –Septicemic –Pneumonic Pneumonic is the only one transmitted through aerosals.Pneumonic is the only one transmitted through aerosals.
Plague: Overview Natural disease of rodentsNatural disease of rodents Fleas that live on rodents transmit the bacteria to humans, in the bubonic form.Fleas that live on rodents transmit the bacteria to humans, in the bubonic form. This disease occurs in many areas of the world, including the United States.This disease occurs in many areas of the world, including the United States.
Plague: Overview U.S. averages 13 cases/yr (17 in 2006)U.S. averages 13 cases/yr (17 in 2006) Plague is endemic in the desert southwest.Plague is endemic in the desert southwest. Most cases occur in summer.Most cases occur in summer.
Microscopic Characteristics Y. pestis appear as single cells or short chains of plump, gram-negative rods.Y. pestis appear as single cells or short chains of plump, gram-negative rods.
Microscopic Characteristics Gram stain: –In direct smears, bacterial cells may be inside or outside of leukocytes. –The Gram smear morphology is suggestive but not specific for Y. pestis. Bipolar staining of a plague smear prepared from lymph aspirated from a bubo of plague patient.
Microscopic Characteristics Bipolar staining occurs when using Wayson, or Giemsa stain.Bipolar staining occurs when using Wayson, or Giemsa stain. CDC
Colony Characteristics Grows well on most standard laboratory media.Grows well on most standard laboratory media. Sheep Blood AgarSheep Blood Agar –Gray-white translucent colonies –Pinpoint, gray- white, non-hemolytic at 24 hours Blood agar plate of Yersinia pestis at 48 hours. CDC/Dr. Brodsky
Non-motileNon-motile Pleomorphic gram-negative bacillusPleomorphic gram-negative bacillus Urease, and oxidase negativeUrease, and oxidase negative Facultative anaerobeFacultative anaerobe Optimal growth at 28 o COptimal growth at 28 o C Facultative intracellular parasiteFacultative intracellular parasite Y. pestis: Physiology
Public Health Aspects of Plague Fleas carry Y. pestis in their intestinal tract.Fleas carry Y. pestis in their intestinal tract. When feeding the fleas regurgitate uncapsulated organisms.When feeding the fleas regurgitate uncapsulated organisms. Bacteria re-encapsulate and grow.Bacteria re-encapsulate and grow. Progeny are resistant to intracellular killingProgeny are resistant to intracellular killing
Bubonic Plague Regional lymphadenitis (Buboes)Regional lymphadenitis (Buboes) –Inguinal, axillary, or cervical lymph nodes most common –80% can become septic –60% mortality if untreated Cutaneous findingsCutaneous findings –Possible papule, vesicle, or pustule at inoculation site –Purpuric lesions - late
Bubo swollen inguinal lymph node or bubo.swollen inguinal lymph node or bubo. After the incubation period of 2-7 days, symptoms of the plague appear.After the incubation period of 2-7 days, symptoms of the plague appear.
Pneumonic Plague PneumonicPneumonic –From aerosol or septicemic spread to lungs. –Person-to-person transmission by respiratory droplet. –100% mortality untreated. Pneumonia progresses rapidly to dyspnea, cyanosis.Pneumonia progresses rapidly to dyspnea, cyanosis. Death from respiratory collapse/sepsis.Death from respiratory collapse/sepsis.
Primary or secondaryPrimary or secondary – Secondary from bubonic or pneumonic forms –100% mortality if untreated Severe endotoxemiaSevere endotoxemia Systemic inflammatory response syndromeSystemic inflammatory response syndrome Shock, Disseminated intravascular coagulopathy (DIC)Shock, Disseminated intravascular coagulopathy (DIC) Adult Respiratory Distress Syndrome (ARDS)Adult Respiratory Distress Syndrome (ARDS) Septicemic Plague
Y. pestis: Virulence Determinants 3 virulence encoded Plasmids3 virulence encoded Plasmids Virulence is up-regulated at 37°CVirulence is up-regulated at 37°C Capsule (F1 antigen)Capsule (F1 antigen)
Yersinia Outer Proteins (Yops) 11 different proteins11 different proteins AntiphagocyticAntiphagocytic Inhibit productionInhibit production –proinflammatory cytokines –tumor necrosis factor CytotoxinCytotoxin
Yops TargetsTargets –dendritic cells –macrophages –Neutrophils –does not target B and T lymphocytes
F-1 Antigen Glycoprotein capsule expressed at 37 0 CGlycoprotein capsule expressed at 37 0 C Not expressed in flea hostNot expressed in flea host AntiphagocyticAntiphagocytic Antibodies to F-1 are protectiveAntibodies to F-1 are protective
Plasminogen activator (fibrinolysin) and Coagulase Plasmid encoded proteinsPlasmid encoded proteins Promote dissemination of organisms from the clot at the bite sitePromote dissemination of organisms from the clot at the bite site Coagulase is produced at 28 0 C but not at 32 0 C.Coagulase is produced at 28 0 C but not at 32 0 C.
Diagnosis Examination of Bubo aspirate, blood, sputumExamination of Bubo aspirate, blood, sputum stained for bipolar stainingstained for bipolar staining Fluorescent-antibodyFluorescent-antibody Culture (hazardous)Culture (hazardous)
Plague Treatment Y. pestis is susceptible to a variety of antibiotics.Y. pestis is susceptible to a variety of antibiotics. –streptomycin, tetracycline, and doxycycline Peumonic plague is contageous and isolation is recommended.Peumonic plague is contageous and isolation is recommended.
Clinical Case 30 year old man from Colorado, went to a hospital emergency department with a 3- day history of fever, nausea, vomiting, and right inguinal lymphadenopathy.30 year old man from Colorado, went to a hospital emergency department with a 3- day history of fever, nausea, vomiting, and right inguinal lymphadenopathy. Patient was not a hunter nor had he been in the woods recently but he did have dogs.Patient was not a hunter nor had he been in the woods recently but he did have dogs. He was discharged home without treatment.He was discharged home without treatment.
Three days later, the man returned and was hospitalized with sepsis and bilateral pulmonary infiltrates.Three days later, the man returned and was hospitalized with sepsis and bilateral pulmonary infiltrates. One of the patient's dogs had serologic evidence of past Y. pestis infection.One of the patient's dogs had serologic evidence of past Y. pestis infection. Cultures of blood and a lymph node aspirate.Cultures of blood and a lymph node aspirate.