Bacteria associated with Circulartory System and Septic Shock VETERINARY BACTERIOLOGY AND MYCOLOGY (3142-304) 1 st semester 2012 Assistant Prof. Dr. Channarong Rodkhum Department of Veterinary Microbiology Faculty of Veterinary Science Chulalongkorn University E-mail : Channarong_CU@hotmail.com Channarong.R@Chula.ac.th
Animal circulartory systems 2
3 General concept No evidence of resident flora in circulatory system Infection comes into blood stream called septicemia Bacterial infection in blood stream called bacteremia
4 Defenses of circulatory system many kinds of defenses in circulatiory system - natural defense proteins (interferon, cytokine, lysozyme) - Cellular immunity - Humoral Immunity [Antibody or immunoglobulin(ig)]
Hemotrophic mycoplasma General characteristics Family Mycoplasmataceae Class Mollicutes Lack of cell wall synthyesis Resistant to -lactam antibiotics Gram stain is not a part of identification process Sensitive to digitonin (Deleterious effect on sterols) Widely distribute in humans, mammals, birds, repiles, and fish Associated mainly with circulatory system hemotrophic mycoplasma or hemoplasma (Erythrocytes s parasite) Hemotrophic mycoplasma : grow on surface of RBCs
Previously classified in order Rickettsiales Family Anaplasmataceae (Eperythrozoon and Haemobartonella) Re-classified as mycoplasma : 16S rrna sequence and electron microscopy Attach to and grow on the surface of RBCs Anemia due to RBCs damage, release autoimmune components Diagnosis : Blood smears stained (Romanovsky-type stain, Acridine orange staining), Fluorescent antibody test, PCR
Diseases : Mycoplasma (Eperythrozoon) ovis : Sheep, Goat ------Eperythrozoonosis Mycoplasma (Eperythrozoon) suis : Pigs------Porcine eperythrozoonois or icteroanemia Mycoplasma haemocanis (Haemobatonella canis) : Dogs------Canine haemobatonellosis Mycoplasma haemofelis (Haemobatonella felis) : Cats-------Feline haemobatonellosis
8 Hemoplasmas of Veterinary Importance Species Dogs Cats Pigs Cattle Sheep and goats Hemoplasma Mycoplasma haemocanis (formerly Haemobartonella canis) Mycoplasma haemofelis (formerly Haemobartonella felis) Mycoplasma (Eperythrozoon) suis Eperythrozoon parvum (yet to be renamed) Mycoplasma (Eperythrozoon) wenyonii Mycoplasma (Eperythrozoon) ovis
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10 Transmission may be transmitted by transfer of infected blood (blood transfusion or use of contaminated needles, surgical instruments, herd or flock management equipment) or via arthropod vectors such as lice, flies, ticks, and mosquitoes. Vertical transmission from mother to offspring has been reported in cats, and swine. Direct transmission associated with fighting is suspected in cats and supported by studies reporting presence of hemoplasma DNA in saliva, on gingiva, and on claw beds of infected cats.
Pathogenicity and Pathogenesis Damage host cells Virulence factors Cytadhesins : attaches to cilia of respiratory epithelial cells Hydrogen peroxide production : induce oxidative stress in host cells Membrane-bound phospholipases : release cytolytic lysophospholipids disrupting host cell membranes Modulins : induce cytokine synthesis inflammation Immune evasion : antigenic variation Chronicity
Diagnosis : Un-culturable Screening by blood smear staining (Romanovsky-type stain, Acridine orange staining) confirmation by Fluorescent antibody test, ELISA, PCR
13 Bartonella sp. Bartonella (formerly known as Rochalimaea) Gram negative bacteria family Bartonellaceae Facultative intracellular parasites Bartonella species can infect healthy people but are considered especially important as opportunistic pathogens. Bartonella are transmitted by insect vectors such as ticks, fleas, sand flies, and mosquitoes. Zoonoses Organism responsible for cat scratch disease
14 Bartonella henselae Bartonella quintana
Electron photomicrograph of intraerythrocytic B. henselae, illustrating the existence of a pore between the bacterium and the extracellular fluid space. Clin. Microbiol. Rev. July 2000 vol. 13 no. 3 428-438 15
16 Transmission Vector to animal (ex. Flea or louse bite) Animal to animal (ex. blood transfusion) Animal to human (ex. Animal scratch) Human to Human (ex. IV drug users are at high risk for Bartonella infections) : Bacillary angiomatosis
Common infection strategy of the bartonellae. 17 Harms A, Dehio C Clin. Microbiol. Rev. 2012;25:42-78
Species B. bacilliformis Reservoir B. quintana Reservoir Bartonella pathophysiology in humans Human reservoir or incidental host? Animal reservoir Pathophysiology Causes Carrion's disease (Oroya fever, Verruga peruana) Causes Trench fever, Bacillary angiomatosis, and endocarditis Distribution 18 Peru, Ecuador, and Colombia Worldwide B. clarridgeiae Incidental Domestic cat Cat-scratch Disease B. elizabethae Incidental Rat Endocarditis B. grahamii Incidental Mouse Endocarditis and Neuroretinitis Cat-scratch Disease, Bacillary angiomatosis, B. henselae Incidental Domestic cat Peliosis hepatis, Endocarditis, Worldwide Bacteremia with fever and Neuroretinitis B. koehlerae Incidental Domestic cat B. vinsonii Incidental Mouse, Dog, Domestic Cat B. washoensis Incidental Squirrel Myocarditis B. rochalimae Incidental Unknown Carrion's disease-like symptoms References: [11][12][13]
19 Parallel adaptive raditions of the genus Bartonella. http://www.biozentrum.unibas.ch/#
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21 Diagnosis of Bartonella sp. Culture : Sheep blood agar / 5% CO2 incubator Screening by blood smear staining (Romanovsky-type stain, Acridine orange staining) confirmation by Fluorescent antibody test, ELISA, PCR
Bartonellosis in cat 22
23 Ehrlichia sp. cocci small gram-negative pleomorphic cocci obligatory intracellular bacteria. stain dark blue to purple with Romanowsky stain. Ehrlichiae are generally round but sometimes highly pleomorphic. replicate in the membrane-bound vacuoles (parasitophorous vacuoles) in the cytoplasm of a specific type of host cells (granulocyte or monocyte) The relatedness of 16S rrna gene sequences of the genus Rickettsia to those of Ehrlichia, Cowdria, Anaplasma, and Wolbachia spp.
24 Ehrlichial organisms are vector-borne emerging human pathogens in the U.S. Human monocytic ehrlichiosis (HME), caused by Ehrlichia chaffeensis (discovered in 1986) E. ewingii which was previously known as a canine pathogen has been recognized as human pathogen. E. sennetsu (renamed to Neorickettsia sennetsu) is another monocytotropic Ehrlichia sp. and the first human pathogen discovered in Japan in the 1950 s and recently found in Malaysia
25 Infected host cells almost Ehrlichia infects monocytes and macrophages E. canis infects monocyte E. ewingii infects granulocytes E. ruminantium infects vascular endothelial cells and neutrophils.
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27 Host range Canine Ehrlichia canis Ehrlichia ewingii Ehrlichia chaffeensis Feline Ehrlichia spp. Human Ehrlichia chaffeensis Ehrlichia ewingii E. sennetsu (renamed to Neorickettsia sennetsu)
28 Transmission Vectors-borne
Diagnosis : 29 Un-culturable on bacterial media can be cultured in cell line Screening by blood smear staining (Romanovsky-type stain, Acridine orange staining) confirmation by Fluorescent antibody test, enzyme-linked immunosorbent assay (ELISA) (IDEXX 4Dx SNAP), PCR
30 Sepsis & Septic shock Septic shock is a medical condition as a result of severe infection andsepsis the microbe may be systemic or localized to a particular site. It can cause multiple organ dysfunction syndrome (formerly known as multiple organ failure) and death. Its most common victims are children, immunocompromised individuals, and the elderly. Frequently, patients suffering from septic shock are cared for in intensive care units (ICU).
31 Causes ( I ) When bacteria or viruses are present in the bloodstream, the condition is known as bacteremia or viremia. Most cases of septic shock (approximately 70%) are caused by endotoxin-producing Gram-negative bacilli If the organisms are particularly virulent, or the host is immunocompromised, then the host organism may develop a condition known as systemic inflammatory response syndrome (or SIRS). Sepsis is a constellation of symptoms secondary to infection due to microorganism toxins and enzymes that manifest as distruptions in heart rate, respiratory rate, temperature and WBC.
32 Cause ( II ) If sepsis worsens to the point of end-organ dysfunction (renal failure, liver dysfunction, altered mental status, or heart damage), then the condition is called severe sepsis. Once severe sepsis worsens to the point where blood pressure can no longer be maintained with intravenous fluids alone, septic shock. The precipitating infections which may lead to septic shock if severe enough include pneumonia, bacteremia, pyelonephritis, meningitis, and pancreatitis