Bacterial enteritides of poultry

Infection with intestinal spirochetes has recently been recognized as a cause of lost production in the poultry industry Little is known about these organisms, so a collection of 56 isolates originating from chickens in commercial flocks in Australia, the United States, The Netherlands, and the United Kingdom was examined Strength of beta-hemolysis on blood agar, indole production, API ZYM enzyme profiles, and cellular morphology were determined, and multilocus enzyme electrophoresis was used to analyze the extent of genetic diversity among the isolates The results were compared with those previously obtained for well-characterized porcine intestinal spirochetes The chicken isolates were genetically heterogeneous They were divided into 40 electrophoretic types distributed among six diverse genetic groups (groups b to g), with a mean genetic diversity of 0587 Strains in two groups (groups d and e) may represent new species of Serpulina, and the groups contained only strains isolated from chickens Three genetic groups contained isolates previously shown to be pathogenic for chickens These corresponded to the proposed species "Serpulina intermedius," to an unnamed group (group e), and to Serpulina pilosicoli Two of the chicken isolates (one "S intermedius" and one S pilosicoli isolate) were strongly beta-hemolytic, two (both "S intermedius") had an intermediate level of beta-hemolysis, and the rest were weakly beta-hemolytic Fourteen isolates of "S intermedius" produced indole, as did one isolate from group d Isolates identified as S pilosicoli resembled porcine isolates of this species, having four to six periplasmic flagella inserted subterminally in a single row at each end of the cell, and had tapered cell ends All other spirochetes were morphologically similar, having seven or more periplasmic flagella and blunt cell ends The identification of three genetic groups containing pathogenic isolates provides an opportunity for more detailed epidemiologic studies with these pathogens and for the development of improved diagnostic tests

Genetic and phenotypic characterization of intestinal spirochetes colonizing chickens and allocation of known pathogenic isolates to three distinct genetic groups

Strain C1T is an anaerobic spirochaete that causes intestinal disease in chickens. Multilocus enzyme electrophoresis analysis and 16S rRNA sequence comparisons have indicated that this spirochaete is a Serpulina strain. In these investigations, various phenotypic and genomic properties useful for establishing a taxonomic identity for strain C1T were studied. As determined by electron microscopy, cells of the spirochaete measured 8-11 x 0.22-0.34 mum and had a typical spirochaete ultrastructure. Each cell had 22-30 flagella. C1T cells formed weakly beta-haemolytic colonies on trypticase soy agar plates containing 5% bovine blood. The spirochaete reached maximum population densities of 10(9) cells ml-1 with a 2-4 h population doubling time in brain heart infusion broth containing 10% calf serum (BHIS broth). C1T cultures in BHIS broth were positive in tests for hippurate hydrolysis and negative for indole production. Glucosamine, N-acetyglucosamine, glucose, fructose, maltose and mannose were growth substrates for the spirochaete in heart infusion broth containing 7% calf serum (HS broth). During growth in HS broth beneath an O2/N2 (1:99) atmosphere, cells of the spirochaete consumed O2 and glucose and produced H2, CO2, acetate, butyrate and ethanol. Strain C1T DNA had a G+C content of 24.6 mol%. Based on DNA-DNA hybridization analyses, the DNA of strain C1T exhibited 24-39% relative reassociation with DNA of Serpulina hyodysenteriae, Serpulina innocens, Serpulina pilosicoli, Serpulina murdochii and Serpulina intermedia. These results indicate that chicken spirochaete strain C1T has many phenotypic properties common to Serpulina species and, based on DNA hybridization analysis, represents a unique Serpulina species. For this new species the name Serpulina alvinipulli is proposed, for which the type strain is C1T (= ATCC 51933T).

Serpulina alvinipulli sp. nov., a new Serpulina species that is enteropathogenic for chickens

One-day-old chicks were infected orally with two strains of weakly hemolytic spirochetes isolated from a human and a pig with intestinal spirochetosis. These spirochetosis both colonized birds, attached end-on to their cecal enterocytes, induced watery diarrhea, and significantly depressed growth rates. Cultures of Serpulina innocens failed to colonize the chicks.

/pdf/pathogenicity-of-human-and-porcine-intestinal-spirochetes-in-4imxmmqf0d.pdf

Pathogenicity of human and porcine intestinal spirochetes in one-day-old specific-pathogen-free chicks: an animal model of intestinal spirochetosis.

This paper presents an overview of intestinal spirochete infections of chickens. It focuses particularly on studies in Australia, where recent surveys of 136 layer and broiler breeder flocks have revealed a high rate of infection (>40%) with intestinal spirochetes. Infection was not detected in broiler flocks. Approximately 50% of isolates from infected flocks were Brachyspira (Serpulina) intermedia or B. pilosicoli, with the other isolates being B. innocens, B. murdochii or the proposed species ‘B. pulli’. No isolates of B. alvinipulli were found. Intestinal spirochetes were significantly associated with wet litter problems and/or reduced egg production. Experimental infection of point-of-lay birds with either B. intermedia or B. pilosicoli caused reduced egg production, and, with B. intermedia, a significant increase in fecal moisture content. Infection with B. innocens caused no significant changes. In-water treatment of a flock with a mixed spirochete infection using lincospectin resulted in a slimy diarrhea lasting for 2–3 weeks, followed by absence of spirochetes for 3 months. Birds treated with tiamulin remained healthy, and had a reduced level of infection with intestinal spirochetes (30%) for 3 months. Trials are under way to test the efficacy of antimicrobials in point-of-lay chickens experimentally infected with either B. intermedia or B. pilosicoli.

/pdf/intestinal-spirochete-infections-of-chickens-a-review-of-qjppn2awd4.pdf

Intestinal spirochete infections of chickens: a review of disease associations, epidemiology and control

Summary A weakly haemolytic spirochete was detected with an unabsorbed fluorescent antiserum to Treponema hyodysenteriae in smears and cultures of scrapings of caecal mucosa of laying hens with diarrhoea. Two groups of experimental chickens were fed a pure culture of this spirochete or homogenated intestinal contents of affected birds. Both groups showed clinical signs of disease such as increased water content of faecal material and slight retardation of growth. A non‐specific typhlitis which histologically resembled milder forms of swine dysentery was seen in the birds from which spirochetes were isolated. The isolate obtained differed in cultural, biochemical, anti‐genic and morphological characteristics from T. hyodysenteriae. The pathological significance of intestinal spirochetes and their possible epidemiological relation to swine dysentery are discussed.

https://www.tandfonline.com/doi/pdf/10.1080/03079458608436285

P.C. vanderValk

Papers

Infectious typhlitis in chickens caused by spirochetes.