|Meinersmann, Richard - Rick
|BRADSHAW, J - Environmental Protection Agency (EPA)
|MOLINA, M - Environmental Protection Agency (EPA)
|SNYDER, B - Environmental Protection Agency (EPA)
Submitted to: Letters in Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/18/2019
Publication Date: N/A
Interpretive Summary: Campylobacter species are a major cause of diarrheal disease in humans, commonly contracted from poultry products. It is not clear how poultry become infected with the organism. The objective of this study was to determine if environmental sampling methods can skew the type of bacteria that is recovered, resulting in loss of traceability of the bacterial lineage. River water was collected for isolation of Campylobacter by three methods (filtering of free-catch water, sediment grab samples, and placement of large cotton swabs in the water) and the recovered organisms were compared by a molecular genetic typing method based on DNA sequence. The highest rate of recovery was by filtering of free-catch water. Types of bacteria that were isolated correlated with the characteristics of the environment surrounding the sample site (such as cattle in a pasture) but the three methods were not different in the types that were recovered. Thus the choice of method can be based on sensitivity without creating a bias of the population that is recovered.
Technical Abstract: It is not clear how best to sample streams to detect Campylobacter that may be introduced from agricultural or community land use. Sixteen sites in the watershed of the South Fork of the Broad River (SFBR) in Northeastern Georgia, USA, were sampled in three seasons. Seven sites were classified as mostly influenced by forest, six sites mostly pasture, and two sites were downstream from waste water pollution control plants (WPC). Collections were made at or near base-flow rate. Sampling was repeated twice in the fall of 2012 and three times in the spring and fall of 2013 at two or more week intervals for a total of 126 samples. Free-catch water and sediment grab samples were taken at each site; Moore’s swabs were placed for up to three days at most sites. A total of 56 isolates of thermophilic Campylobacter were recovered; Thirteen samplings were positive by two or three methods and 26 samplings were positive by only one method; once by Moore’s swab only and 25 times by free-catch water only. Campylobacter was detected at 58% of cattle pasture sites, 30% of forested sites and 81% of WPC sites. Free-catch water samples were more efficient than Moore’s swabs or sediment samples for recovery of Campylobacter, which was more likely to be detected in streams near cattle pastures and human communities than in forested land.