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A Gallus gallus Model for Determining Infectivity of Zoonotic Campylobacter
Citation:
Lye, D., I. Struewing, T. Gruber, K. Oshima, E. Villegas, AND J. Lu. A Gallus gallus Model for Determining Infectivity of Zoonotic Campylobacter. Frontiers in Microbiology. Frontiers, Lausanne, Switzerland, 10:2292, (2019). https://doi.org/10.3389/fmicb.2019.02292
Impact/Purpose:
Understanding the role of waterfowl as reservoirs for zoonotic Campylobacter species in recreational waters has important public health implications, as Campylobacter are a major cause of zoonotic enteric infections commonly transmitted by ingestion of contaminated water, and fecal releases from wild birds have been reported to play a significant role in water quality impairment of recreational waters. We were able to develop a non-invasive chick model of infection that mimics the natural route of infection to assess infectivity of environmental Campylobacter isolates and use passive filter plating procedure to assess bacterial burden in animals following infection, including persistence of various Campylobacter species in a natural host. The techniques developed will be useful towards developing more accurate risk assessment models of waterfowl-derived Campylobacter spp. human infections in a recreational water exposure scenario, which is of concern to the general public, as well as local communities and regional partners.
Description:
To better understand public health implications of waterfowl as reservoirs for zoonotic sources of Campylobacter in recreational waters, we developed a Gallus gallus (chick) model of infection to assess pathogenicity of environmental isolates of Campylobacter. This method involved exposure of one-day-old chicks using the natural route of infection, through ingestion of water. Viable Campylobacter from laboratory infected animals were monitored using a modified non-invasive sampling of fresh chick excreta followed by a passive polycarbonate-filter migration culture assay. This method was used to evaluate infectivity of three laboratory strains of Campylobacter spp. (C. coli, C. jejuni, and C. lari), three clinical isolates of C. jejuni, and four environmental Campylobacter spp. isolated from California gulls (Larus californicus). Results revealed chicks were successfully infected with all laboratory and clinical isolates of Campylobacter spp. through ingestion of Campylobacter-spiked water with infection rates ranging from less than 10% to over 90% in a dose-dependent manner. More importantly, exposure of chicks with Campylobacter spp. isolated from Gallus gallus excretaalso resulted in a successful establishment of infection (up to 90%). Each Campylobacter spp. monitored contained at least 7.5 × 104 CFU g-1 of feces seven days post-exposure. These results suggest that Gallus gallus model can be used to assess infectivity of Campylobacter isolates including gull and human clinical isolates. Use of an avian animal model can be applied to assess the importance of birds, like the Gallus gallus, as potential contributors of waterborne-associated outbreaks of campylobacteriosis.
