Intestinal spirochaetes (genusBrachyspira) colonise wild birds in the southern Atlantic region and Antarctica

Abstract

IntroductionThe genus Brachyspira contains well-known enteric pathogens of veterinary significance, suggested agents of colonic disease in humans, and one potentially zoonotic agent. There are recent studies showing that Brachyspira are more widespread in the wildlife community than previously thought. There are no records of this genus in wildlife from the southern Atlantic region and Antarctica. Our aim was therefore, to determine whether intestinal spirochaetes of genus Brachyspira colonise marine and coastal birds in this region.MethodFaecal samples were collected from marine and coastal birds in the southern Atlantic region, including sub-Antarctic islands and Antarctica, in 2002, 2009, and 2012, with the aim to isolate and characterise zoonotic agents. In total, 205 samples from 11 bird species were selectively cultured for intestinal spirochaetes of genus Brachyspira. To identify isolates to species level, they were subjected to phenotyping, species-specific polymerase chain reactions, sequencing of partial 16S rRNA, NADH oxidase (nox), and tlyA genes, and phylogenetic analysis. Antimicrobial susceptibility tests were performed.ResultsFourteen unique strains were obtained from 10 birds of three species: four snowy sheathbills (Chionis albus), three kelp geese (Chloephaga hybrida subsp. malvinarum), and three brown skua (Stercorarius antarcticus subsp. lonnbergi) sampled on the Falkland Islands, Tierra del Fuego in Argentina, South Georgia, South Shetland Islands, and the Antarctic Peninsula. Five Brachyspira strains were closely related to potentially enteropathogenic Brachyspira sp. of chickens: B. intermedia (n=2, from snowy sheathbills), and B. alvinipulli (n=3, from a kelp goose and two snowy sheathbills). Three strains from kelp geese were most similar to the presumed non-pathogenic species ‘B. pulli’ and B. murdochii, whereas the remaining six strains could not be attributed to currently known species. No isolates related to human strains were found. None of the tested strains showed decreased susceptibility to tiamulin, valnemulin, doxycycline, tylvalosin, lincomycin, or tylosin.ConclusionsThis is the first report of intestinal spirochaetes from this region. Despite limitations of current diagnostic methods, our results, together with earlier studies, show that Brachyspira spp., including potentially pathogenic strains, occur globally among free-living avian hosts, and that this genus encompasses a higher degree of biodiversity than previously recognised.

Occurrence ofYersinia rohdeiamong feral reindeer (Rangifer t. tarandus) and kelp gulls (Larus dominicanus) on the Sub-Antarctic island South Georgia

“…High level of biosecurity was applied, to minimize the risk of introducing new microbes into these relatively pristine areas, and appropriate protective gear was used by the staff retrieving the samples. The samples were obtained with sterile cotton swabs, which were stored in Amies charcoaled medium (Copan Italia S.P.A.), and refrigerated at 5-10°C for a duration of 1-3 weeks until arrival at the laboratory in Sweden where they were cultured within 24 h [9].…”

“…All samples from all locations were analysed for presence of, among other microbes, bacteria of the genus Yersinia. For a list of locations and a complete list of avian species sampled within the entire study, please see Jansson and and co-workers [9].…”

“…Research on vertebrate-associated bacteria in these habitats is rare, but a couple of studies have focused on human-associated and zoonotic agents in wildlife and the environment around research stations [7,8] and also in more remote locations [9] .Yersinia spp have previously been isolated in samples from semidomesticated reindeer in Norway and Finland [10], and we therefore hypothesized that such microbes may be present also in the population on South Georgia.…”

“…The overall aim of this research expedition was to isolate and characterize zoonotic agents and screen for antibiotic resistant bacteria in marine birds [9], but samples were taken also from mammals, when possible. Our aim in this paper was to identify Yersina isolates to species level and to provide a description of the Yersinia strains found in such an isolated population as the South Georgian reindeer and in its habitat.…”

Aportaciones al diagnóstico y control de la disentería porcina = Contributions to the dianosis and control of swine dysentery

“…Sin embargo, mediante PCR y técnicas inmunohistoquímicas se ha identificado en biopsias de cerdos con colitis y también se ha aislado a partir de muestras de líquido sinovial procedentes de cerdos con cojera, demostrando su capacidad de propagación a nivel sistémico (Hampson et al 1999;Jensen et al 2010). También se ha aislado en granjas de ponedoras y de pollos de engorde así como de aves silvestres (Jansson et al 2015). Se ha asociado con problemas de cama húmeda en avicultura intensiva aunque existen dudas sobre su papel en la etiología de esta enfermedad debido que en todos los casos se ha tratado de infecciones múltiples con varias especies de Brachyspira implicadas (Stephens & Hampson 1999;Mappley et al 2014).…”