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42 Cards in this Set
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Salmonella
general features G: shape: oxygen: lactose? motile by: important: Habitat: |
Salmonella
general features G: - shape: rod oxygen: facultatively anaerobic lactose? nonlactose fermenters motile by: peritrichous flagella important: zoonotic pathogen Habitat: intestinal tract of vertebrates including fish, reptiles and mammals |
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Salmonella Characterics
3 types, and characteristics |
Salmonella Characterics
3 types, and characteristics 1)0(Somatic) antigen - LPS 9endotoxin), ehat stable, designated by Arabic numerals, may have more than 1, classified in to 50 groups A-Z and 51-65, majority B,C,D,E 2) H (Flagellar) antigens: heat labile, lower case alphabet P phase 1, Arabic numbers H phase 2 3) Vi (Virulence or Capsular) antigens: heat stable, composed of polysaccharide, not for erotyping only 3 types have: S Typhi, S Hersfeldii, and S. Dublin |
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example Salmonella typhimurium it1, 4, [5], 12: i: 1,2
explain |
example Salmonella typhimurium it1, 4, [5], 12: i: 1,2
it1, 4, [5], 12 are O antigens, it means present due to phage conversion, [] means present or absent, i isflagellar antigen, 1,2, capsular antigens |
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Salmonella Classification
2 species, and subspecies |
Salmonella Classification
2 species, and subspecies 1) S. Enterica subspecies: enterica, salmae, arizonae, diarizonae, indica, & houtenae 2) S. bongori - non pathogenic |
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Salmonella should be called by:
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Salmonella should be called by:
species, subspecies and serovar commpon practice, serovar as species: S. Typhimurium |
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Salmonella species
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Salmonella species
over 2,300- species or sero-varities (serotypes) |
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Species nomenclature:
named for: (2 with examples) |
Species nomenclature:
named for: (2 with examples) disease syndrom cause: S. Pullorum S. Abortusequi S. Abortusovis S. Abortusbovis location first isolated S. Manhattan S. Sandiego S. Texas S. Arizona |
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Host adaptation
Grouped according to association with hosts |
Host adaptation
Grouped according to association with hosts Group 1 human host, S. Typhi, S.Parathypi, S. Schottmulleri, S. Hirchfeldii, S. Sendai Group II Cattle - S. Dublin Swine, Sheep, Horse, Poultry (poultry strains only affect poultry) Group III Unadapted - Most species S. Typhimurium |
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Salmonella
Mode of infection (4) |
Salmonella
Mode of infection (4) 1) oral transmission via feces, animalfeeds and animal protein supplements 2) transovarian transmission 3) contaminated milk and milk products 4) Flies - carry on body surface or in digestive tract |
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Salmonella Predisposing Factors
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Salmonella Predisposing Factors
Stress, e.g. shipping, cold, crowding Horse - stress of hospitalization or surgery Many animals asymptomatic carriers, with stress infection develops 2 sources: clinically affected animals and asymptomatic carriers |
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Salmonella Virulence Factors (5)
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Salmonella Virulence Factors (5)
1) Enterotoxins 2) Cytoxins 3) LPS 4) Sideorpores 5) Heat-Shock Proteins |
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Salmonella
Virulence Factors Enterotoxins (3 Properties) |
Salmonella
Virulence Factors Enterotoxins 1) Cholera toxin-like 2) Structurally and functionally similar to enterotoxin of E. coli 3) Heat labile |
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Salmonella
Virulence Factors Cytotoxins #? damage: |
Salmonella
Virulence Factors Cytotoxins # 3 damage: to intestinal epithelial cell |
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Salmonella
Virulence factors LPS cause: (2) proof |
Salmonella
Virulence factors LPS cause: (2) 1) vascular damage and thrombosis in intestine 2) systemic changes (fever, disseminated intravascular coagulation, circulatory collapse, shock proof: mutants with defect inLPS are less virulent |
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Salmonella
Virulence factors Flagella role: |
Salmonella
Virulence factors Flagella role: motility increases chance of organism coming into contact with epithelial cells |
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Salmonella
Virulence factors Siderophores What are they? Who makes them? What do they do? E.g. |
Salmonella
Virulence factors Siderophores What are they? iron chelatorsthat have a high affinitiy for iron Who makes them? bacteria What do they do? capture iron in host fluids and return to bacteria through specific outer membrane E.g. S. Typhimurium makes enterochelin - phenolate siderophore |
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Salmonella
Virulence factors Heat-Shock Proteins produced: Essential for: |
Salmonella
Virulence factors Heat-Shock Proteins produced: in response to stress of bact Essential for: for survival in macrophages |
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Salmonella
Pathogenesis Intestinal infections (3) |
Salmonella
Pathogenesis Intestinal infections (3) 1) Colonization of intestine a)organizms reach intestine b)adhere to enterocytes c) adhere to receptors on epithelial cells d) invade and dmage intestinal epithelium e) stimulate fluid production and excretion f) stress allows attachment KEY FEATURE: Ability to survive & multiply inside macrophages 2)Invasion of intestinal epithelium a) involves ileum villous tips b) ability of Salmonella organisms to srvie and multiply inside cells is critical to the outcome of the infection: Iable to resist destructive processes II bacterium protected from antibiotics, antibodies and complement c) enteritis results in a shortening and distortionof villik degeneration and abnormal extrusion of enterocytes, increased emptying of goblet cells (increased mucus production ) and neutrophilic infiltration and migration into the lumen (neutrophil shedding in feces) 3) Stimulation of fluid production and excretion a) net secretion of water, bicarbonate,and chloride into the lumen b) loss of epithelial cells results in impaired absorption |
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Salmonella
Pathogenesis Intestinal Infections Colonization of intestine |
Salmonella
Pathogenesis Intestinal infections 1) Colonization of intestine a)organizms reach intestine b)adhere to enterocytes c) adhere to receptors on epithelial cells d) invade and dmage intestinal epithelium e) stimulate fluid production and excretion f) stress allows attachment KEY FEATURE: Ability to survive & multiply inside macrophages |
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Salmonella
Pathogenesis Intestinal Infections Invasion of intestinal epithelium |
Salmonella
Pathogenesis Intestinal Infections Invasion of intestinal epithelium 2)Invasion of intestinal epithelium a) involves ileum villous tips b) ability of Salmonella organisms to srvie and multiply inside cells is critical to the outcome of the infection: Iable to resist destructive processes II bacterium protected from antibiotics, antibodies and complement c) enteritis results in a shortening and distortionof villik degeneration and abnormal extrusion of enterocytes, increased emptying of goblet cells (increased mucus production ) and neutrophilic infiltration and migration into the lumen (neutrophil shedding in feces) |
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Salmonella
Pathogenesis Intestinal Infections Stimulation of fluid production and excretion |
Salmonella
Pathogenesis Intestinal Infections Stimulation of fluid production and excretion 3) Stimulation of fluid production and excretion a) net secretion of water, bicarbonate,and chloride into the lumen b) loss of epithelial cells results in impaired absorption |
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Salmonella
systemic infections pathway (3) |
Salmonella
systemic infections (3) 1) Free Salmonella in mucosa or submucosa are transported via lymphatics to regional lymph nodes 2) From lymph noedes S travel via efferent lymph vessels, drain into blood circulation 3) Bacteria are filtered out of circulation by RE system particularly in spleen and liver |
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Salmonella
Key virulence factor: |
Salmonella
Key virulence factor: LPS (endotoxin) |
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Salmonella
what causes septicemic disesease? septicemic disease & host |
Salmonella
septicemic disease & host host adapted produce septicemic disease S. Typhi in humans --> typhoid, S. choleraesuis in pigs. S. Dublin in cattle --> abortion, S. Abortusovis in sheep, S. Abortusequi in horse --> abortion |
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Salmonella diseases(4)
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Salmonella diseases(4)
1) enteritis (diarrhea) 2) Septicemia - systemic salmonellosis 3) abortion 4) food piosoning in humans (actually an infection) 24 hr diarrhea |
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Salmonella
Bovine Salmonellosis 2 important seroypes: symptoms |
Salmonella
Bovine Salmonellosis 2 important seroypes: S. Dublin - host adapted S. Typhimurium symptoms Adult cattle: fever, depression, severe diarrhea with blood and mucus in feces, abortion common sequel |
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Salmonella
Calf Abortion mechanisms |
Salmonella
Abortion mechanisms culture positive cases: bacterimia in dam results in infection of placenta and/or fetus -- resulting fetal death culture negative case: bactereimia release of prostaglandin (PGF2alpha) subsequent lysis of corpus luteum, aborition follows in 2-3 days, placenta culture negative |
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Equine Salmonellosis
Serotypes Symptoms |
Equine Salmonellosis
Serotypes S. Typhimurium - most common S. Newport S. Enteritidis S. Heidelberg S. abortusequi - disappeared in US Symptoms acute form: fever, anorexia, depression and diarrhea Foals-septicemia; highly fatal infection animals that survive acute form have diarrhea for months |
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Swine Salmonellosis
Serotypes Symptoms |
Swine Salmonellosis
Serotypes S. Choleraesuis, S Typhimurium Symptoms: primarily diarrhea S. Choleraesuis - purplish areas in ears, rump, abdomen, high fever, death 1-3 days |
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Ovine Salmonellosis
Serotypes: symptoms |
Ovine Salmonellosis
Serotypes: S. Abortusovis - host adapted - causes abortion usually during last 2 months of pregnancy S Typhimurium and S Dublin cause enteritis, septicemia and abortion (dublin - abortion) symptoms |
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Can ine and Feline Salmonellosis
prevalence: in greyhounds: |
Can ine and Feline Salmonellosis
prevalence: clinical disease not common in greyhounds: fromcontaminated raw meat |
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Avian Salmonellosis
Serotypes Symptoms what type of disease? Who does it affect? How transmitted? |
Avian Salmonellosis
Serotypes S. pullorum causes Pullorum disease or "Bacillary White Diarrhea" S. gallinarum causes Fowl Typhoid both host adapted what type of disease? septicemic Who does it affect? primarily chickens and turkeys, rare in commercial poultry How transmitted? through egg by transovarian infection |
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Avian Salmonellosis
S. pullorum mortality: young v old maintain orgainsm in? Transmission? Infection by? - causes? Detect disease how? |
Avian Salmonellosis
S. pullorum mortality: young v old highly fatal in young chicks, older chicks more resistant, older birds carriers maintain orgainsm in? ovaries Transmission? transovarian Infection by? - causes? inhalation highly infective: - caseous areas in lungs, ingestion - caseous areas in gizzard Detect disease how? serologic tests |
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Avian Salmonellosis
S. gallinarum causes: Oranism maintained: Transmitted: (2) Signs: Lesions: |
Avian Salmonellosis
S. gallinarum causes: fowl typhoid in chicken and turkeys Oranism maintained: in ovary of carrier birds and Transmitted: (2) vertically (egg) or horizontally (feces or broken eggs), also by tick Signs:inhalation leads to acute septicemic disease, weakens, hyperexcitability, paresis and diarrhea Lesions: meningitis - multiple small necrotic areas in liver and heart |
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Avian Salmonellosis
National Eradication Program outbreaks (3 steps) |
Avian Salmonellosis
National Eradication Program outbreaks (3 steps) 1) Pullorum and Fowl typhoid mandatory reportable in US 2) outbreaks placed under quarantine 3) periodic testing 4) esp in breeding flocks |
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Avian Salmonellosis
S. Typhimurium Signs: Significant: |
Avian Salmonellosis
S. Typhimurium Signs: often clinically inapparent, enteritis, diarrhea and septicemia in severe cases Significant: is from subsequent contamination of chicken meat |
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Avian Salmonellosis
S. Anatum causes: |
Avian Salmonellosis
S. Anatum causes: Keel disease in ducks |
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Salmonella
Diagnosis: ID: Immunity (2): Vaccines (2): Treatment: Resistance? Control Measures (3) |
Salmonella
Diagnosis significance: Any time S. isolated, important either as cause of immediate problem or potential one ID: of serotype : useful in poultry, exam blood or serum for presence of antibody Immunity (2): humoral and cell mediated IgA - local imunity Serum IgG anbs against O-specidfic polysaccharide of LPS Vaccines (2): 1) live, stimulate more effective cell0mediated immune response 2) Mutants using molecular techniques - e.g. auxotrophic mutants Treatment: Abx valuable Resistance? multible abx resistance common - must conduct sensitivity test Tx of enteric disease with abx that S. is resistant to may result in production of systemic disease, and may increase lenght of time animal will shed organism and possibly result in a carrier animal Control Measures (3) 1) reduce contamination of environment 2) eliminate source of infection 3) minimize stresses |
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Salmonellosis in Humas
3 syndroms (symptoms) MDR Salmonella 2 serotypes importance: |
Salmonellosis in Humas
3 syndroms (symptoms) 1) Typhoid fever - caused by S. Typhi, humans only reservoir, infrequent disease in US 2) Enteric fever - caused by S. Paratyphi A, S. Schottmuelleri and S. Hirschfeldii 3) Most common Gastroenteritis - contracted mainly through the consumption of raw or undercooked contaminated food of animal origin (meat, chicken, eggs and milk) symptoms: diarrhea, abdominal pain 2 most common serotypes involved: S. Typhimurium and s. Enteritidis MDR Salmonella: Multi-drug resistant Salmonella - major health concern 2 serotypes importance: DT104 and Newport - common in cattle and causing growing share of infection in humans DT104 resistant to ampcillin, chloramphenicol, streptomycin, sulfonamides and tetracyclin, in last 100 years, killed 40% infected cattle, ground meat main source DT104: beef, Newport: dairy Newport - resistant: beta-lactam aintmicrobial agents: amoxicillin/clavulanate, ampicillin, cefoxitin, ceftiofur ceftriaxone, cephalothin, - attributable to plasmid, associated with dairy farms |
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Salmonella Summary
Species: G? Shape? O2? Lactose fermenter? Antigens: Serogroups: Serotypes: |
Salmonella Summary
Species: S. enterica (subsp, enterica) G? - Shape? rod O2? facultative Lactose fermenter? nonlactose fermenter Antigens: O,H, and Vi Serogroups: 50 groups (O antigen) Serotypes: >2,300(O and H antigen) |
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Salmonella Summary
Serotypes adapted to: Mode of infection: Important predisposing factor: Virulence factors: Survives in: Infections: |
Salmonella Summary
Serotypes adapted to: host Mode of infection: oral, transovarian in Chickens Important predisposing factor: stress Virulence factors: enterotoxins and endotoxin Survives in: phagocytic cells Infections: Intestinal (enterotoxins) and Systemic (endotoxin) |
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Salmonella Summary
Diseases: (4) Treatment: (important aspect) MDR Salmonella: |
Salmonella Summary
Diseases: Salmonellosis (4) 1) enteritis 2) septicemia 3) abortion 4) food poisoning Treatment: (important aspect) antibiotics (susceptibility testing needed) MDR Salmonella: DT104 and Newport |