5/28/2023 0 Comments Pigeon role in goose goose duckAlthough reliable methods can identify human fecal contamination in water without cultivating indicator bacteria ( 7), tools for bird fecal source identification are less widely tested ( 12, 21, 26, 35– 37). The ability to rapidly identify and quantify fecal contamination from birds will improve our ability to estimate human health risk from contaminated waters. The relative human health risks of bird and human fecal contamination will be more amenable to measurement once reliable methods are developed to distinguish them quantitatively. For example, molecular evidence indicates that genotypes of certain parasites in birds, such as Giardia and Cryptosporidium, are host adapted and cannot cross-infect among different hosts ( 20, 57). Recently, because of avian influenza, concerns have risen about pathogen movement due to bird migration ( 8, 10, 17, 28, 30).Īlthough pathogens occur in bird feces, exposure to bird feces is considered less harmful to humans than exposure to other sources of fecal contaminants, especially that of humans ( 43, 51). Bird feces are also a source of antibiotic resistance genes ( 34, 39, 50). occur in bird feces ( 11, 18, 19, 42) and can infect domestic poultry and humans ( 27, 41) and contaminate shellfish ( 1). coli and Campylobacter, Salmonella, Giardia, and Cryptosporidium spp. Their feces are sources of fecal coliforms, enterococci, and Escherichia coli, and their presence is correlated with elevated fecal indicator bacteria (FIB) and beach closures ( 2, 22, 23, 38). Marker distributions across North America and in New Zealand suggest that they will have broad applicability in other parts of the world as well.Ĭontamination from gulls, Canada geese, ducks, and other birds negatively impacts water quality ( 5, 16, 24, 33a, 49, 56). These assays detected four important bird groups contributing to fecal contamination of waterways: gulls, geese, ducks, and chickens. In the United States, Canada, and New Zealand, the three markers differed in their geographic distributions but were found across the range tested. GFD was 100% avian specific and occurred in gulls, geese, chickens, and ducks. GFC cross-reacted with 35% of sheep samples but occurred at about 100,000 times lower concentrations in sheep. GFB and GFC were 97% and 94% specific to gulls, respectively. GFD detected down to 0.1 mg chicken feces/100 ml (corresponding to 13 Escherichia coli MPN/100 ml). GFC detected down to 0.1 mg gull feces/100 ml (corresponding to 2 gull enterococci most probable number /100 ml). Quantitative PCR assays for GFC and GFD were developed using SYBR green. Three PCR assays, designated GFB, GFC, and GFD, were based on recovered sequence fragments. Recovered sequences were related to Enterobacteriaceae (47%), Helicobacter (26%), Catellicoccus (11%), Fusobacterium (11%), and Campylobacter (5%). The subtracters were rRNA genes amplified from human, dog, cat, cow, and pig feces. We used subtractive hybridization of PCR-amplified gull fecal 16S RNA genes to identify avian-specific fecal rRNA gene sequences. Rapid identification and quantification of avian contamination would therefore be useful to prevent overestimation of human health risk. Avian feces contaminate waterways but contribute fewer human pathogens than human sources.
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