L6 Enterobacteriales Part 3 RGutierrez Summer 2024-1 PDF

Escherichia coli: Part 3 ENTEROBACTERIACEAE Escherichia coli APEC: avian pathogenic E. coli POULTRY: Clinical manifestations : 1. 2. 3. 4. 5. 6. Neonatal colibacillosis Respiratory colibacillosis Egg yolk peritonitis Scabby hip/necrotic dermatitis Swollen head syndrome Coligranuloma Major pathogen w...

Escherichia coli: Part 3 ENTEROBACTERIACEAE Escherichia coli APEC: avian pathogenic E. coli POULTRY: Clinical manifestations : 1. 2. 3. 4. 5. 6. Neonatal colibacillosis Respiratory colibacillosis Egg yolk peritonitis Scabby hip/necrotic dermatitis Swollen head syndrome Coligranuloma Major pathogen within the poultry industry APEC strains: ST95 and ST131 or O1, O2, and O18 APEC are invasive strains Zoonotic potential ? (Human UPEC) ENTEROBACTERIACEAE Escherichia coli APEC: avian pathogenic E. coli POULTRY: Neonatal colibacillosis 1w old chicks Often after yolk sac infection and/or omphalitis Enlargement of the liver and spleen Increased fluid in body cavities Depression and anorexia Drooping of the head Septicemia -> Death 1 “Mushy chick” In severe cases, the body wall and overlying skin become affected and may undergo lysis, resulting in chicks that look dirty and wet. ENTEROBACTERIACEAE Escherichia coli Risk factors: exposure to ammonia and dust in the environment APEC: avian pathogenic E. coli APEC infection occurs via inhalation of feces-contaminated dust. Secondary infection – viral infection before… POULTRY: Respiratory colibacillosis 4-9 w old birds Depression Fever Mortality up to 20% Edema (histopathology) Airsacculitis with a serous to fibrinous exudate Then, general infection resulting in perihepatitis and/or pericarditis Septicemia (colisepticemia) -> death 2 Guabiraba & Schouler, 2015; FEMS Micr. Lett. ENTEROBACTERIACEAE Escherichia coli APEC: avian pathogenic E. coli POULTRY: Egg yolk peritonitis 21-80 w age chicken Diagnosed at necropsy Sporadic deaths in layers Fibrin or albumen-like material with a cooked appearance among the abdominal viscera E. coli is isolated as pure culture Serotypes: O166, O64, O111 3 Srinivasan et al., 2013; Asian Pac. J Trop Biomed ENTEROBACTERIACEAE Escherichia coli APEC: avian pathogenic E. coli POULTRY: Scabby hip/necrotic dermatitis Discoloration and thickening of the skin and inflammation of the subcutaneous tissues Loss of feathers Low mortality Dead birds decompose quickly Frequently also other bacteria present: C. perfringens, S. aureus 4 ENTEROBACTERIACEAE Escherichia coli APEC: avian pathogenic E. coli POULTRY: Swollen head syndrome Edematous swelling over the eyes of birds Lesions consisting of a gelatinous edema on the facial and periorbital tissues with caseous exudate Usually begins after an acute rhinitis caused by pneumovirus being followed by the invasion of the subcutaneous skin tissues by APEC 5 ENTEROBACTERIACEAE Escherichia coli APEC: avian pathogenic E. coli POULTRY: Coligranuloma Disease of old birds Chronic condition, possibly following a colisepticemia Characterized by multiple granulomas in liver, cecum, duodenum and mesentery Granuloma on the serosal surface Associated with lingering mortality (up to 75 % has been reported) 6 Sawale et al., 2017; Int J Livest Res ENTEROBACTERIACEAE Escherichia coli Example: ETEC in Piglets DIAGNOSIS - Varies by animal species, symptoms, age, feces type - Cultivation => in some cases results in almost pure cultures Luppi, 2017 ENTEROBACTERIACEAE Escherichia coli XLD agar Phenol red Bile salts H2S detector/ lysine Lactose/ Sucrose/xylose Peptones Brilliant green agar Phenol red brilliant green Lactose and Sucrose Peptones Neutral red Bile salts and crystal violet Lactose Peptones MacConkey agar ENTEROBACTERIACEAE Escherichia coli Serotyping methods DNA-amplification methods (colony PCR) Anti-F5 latex NC Enzyme-linked immunosorbent assays (ELISA) are available Salmonella: Part 1 ENTEROBACTERIACEAE Salmonella Characteristics Gram-negative rods (Enterobacteriaceae) Its reservoir is the intestinal tract of warm-blooded and cold-blooded animals (subclinical secretors) Remarkable ability to survive under adverse conditions Clinical disease is characterized by: - Systemic septicemia (also termed as typhoid) - Enteritis - Abortion Other less common clinical presentations include arthritis, respiratory disease, necrosis of extremities, and meningitis ENTEROBACTERIACEAE Salmonella spp. Classification S. enterica Subspecies: enterica (type) salamae arizonae diarizonae houtenae indica & >2600 serovars/serotypes/varieties (60% are subsp. enterica) S. bongori Cold-blooded animals Environmental Can infect humans 21 serotypes ENTEROBACTERIACEAE Salmonella enterica subsp. enterica LPS (O antigen) Flagella (H) Capsular polysaccharide (K / Vi) Kauffmann and White classification ENTEROBACTERIACEAE Salmonella enterica subsp. enterica https://www.msdvetmanual.com/ ENTEROBACTERIACEAE Salmonella enterica subsp. enterica Ecology Pathovars 2 1 Severe systemic disease Systemic infections involving the reproductive tract Acute enteritis or subclinical infections ENTEROBACTERIACEAE Salmonella enterica subsp. enterica Ecology Pathovars Host-restricted Host-specific Typhoid vs non-typhoid Salmonella Diverse genome Degraded genome No biofilm ENTEROBACTERIACEAE Salmonella enterica subsp. enterica Classification by ecology Associated mainly (aprox. 99%) with one host sp. Example: S. Typhi in humans S. Gallinarum in fowls S. Abortusovis in sheep ENTEROBACTERIACEAE Salmonella enterica subsp. enterica Classification by ecology Produce disease primarily in one host sp. (approx. 95%) but cause a small number of infections in other animals also Example: S. Dublin in cattle ENTEROBACTERIACEAE Salmonella enterica subsp. enterica Classification by ecology They can induce gastroenteritis in a broad range of unrelated host species Example: S. Typhimurium S. Enteritidis ENTEROBACTERIACEAE Salmonella enterica subsp. enterica Classification by pathovars 1. Severe systemic infections Transmission = via fecal–oral route / inhalation Bacterial multiplication primarily in the macrophage monocyte lineage GI colonization only in later stages of infection Examples: - S. Typhi – Humans - S. Gallinarum – poultry - S. Choleraesuis - pigs 2. Systemic infections/ reproductive tract Transmission = via fecal–oral route / inhalation Infection involves reproductive tract of pregnant or eggs lay Enteritis and systemic in young animals Most serovars persist after convalescence (epidemiology) Examples: - S. Abortusequi – Horses - S. Abortusovis – sheep - S. Dublin - cattle ENTEROBACTERIACEAE Salmonella enterica subsp. enterica Classification by pathovars 3. Non-systemic serovars Transmission = via fecal–oral route Vast majority of serovars Colonize the GI tract of healthy animals May cause enteritis or subclinical infections High levels of fecal shedding! (contamination of food chain) Some serovars can be associated with more than one pathovars, depending on the animal host: S. Enteritidis and S. Typhimurium ENTEROBACTERIACEAE Salmonella enterica subsp. enterica Pathogenesis Virulence Factors: Knodler & Elfenbein, 2019;Trends in Micr. Flagella Fimbriae Type III secretion systems (T3SSs) Toxins Two-component regulatory systems Vi capsular antigen (S. Typhi and S. Paratyphi only) ENTEROBACTERIACEAE Salmonella enterica subsp. enterica Pathogenesis Biphasic and monophasic salmonellae Salmonella serotypes can be biphasic, producing both phase 1 flagellin (FliC) and phase 2 flagellin (FljB) ENTEROBACTERIACEAE Salmonella enterica subsp. enterica Pathogenesis Sansonetti, 2004; Nature Rev. ENTEROBACTERIACEAE Salmonella enterica subsp. enterica Pathogenesis & Salmonella pathogenicity islands (SPIs) ENTEROBACTERIACEAE Salmonella enterica subsp. enterica Salmonella in cattle Worldwide distribution Serovars Dublin and Typhimurium (their distribution varies geographically) Others serovars only in