Frequency and Spatial Distribution of Environmental Campylobacter spp

Abstract

Humans are exposed to Campylobacter spp. in a range of sources via both food and environmental pathways. For this study, we explored the frequency and distribution of thermophilic Campylobacter spp. in a 10-by 10-km square rural area of Cheshire, United Kingdom. The area contains approximately 70, mainly dairy, farms and is used extensively for outdoor recreational activities. Campylobacter spp. were isolated from a range of environmental samples by use of a systematic sampling grid. Livestock (mainly cattle) and wildlife feces and environmental water and soil samples were cultured, and isolates were presumptively identified by standard techniques. These isolates were further characterized by PCR. Campylobacter jejuni was the most prevalent species in all animal samples, ranging from 11% in samples from nonavian wildlife to 36% in cattle feces, and was isolated from 15% of water samples. Campylobacter coli was commonly found in water (17%) and sheep (21%) samples, but rarely in other samples. Campylobacter lari was recovered from all sample types, with the exception of sheep feces, and was found in moderate numbers in birds (7%) and water (5%). Campylobacter hyointestinalis was only recovered from cattle (7%) and birds (1%). The spatial distribution and determinants of C. jejuni in cattle feces were examined by the use of model-based spatial statistics. The distribution was consistent with very localized within-farm or within-field transmission and showed little evidence of any larger-scale spatial dependence. We concluded that there is a potentially high risk of human exposure to Campylobacter spp., particularly C. jejuni, in the environment of our study area. The prevalence and likely risk posed by C. jejuni-positive cattle feces in the environment diminished as the fecal material aged. After we took into account the age of the fecal material, the absence or presence of rain, and the presence of bird feces, there was evidence of significant variation in the prevalence of C. jejuni-positive cattle feces between grazing fields but no evidence of spatial clustering beyond this resolution. The spatial pattern of C. jejuni is therefore consistent with that for an organism that is ubiquitous in areas contaminated with cattle feces, with a short-scale variation in infection intensity that cannot be explained solely by variations in the age of the fecal material. The observed pattern is not consistent with large-scale transmission attributable to watercourses, wildlife territories, or other geographical features that transcend field and farm boundaries.

Application of Pulsed-Field Gel Electrophoresis To Identify Potential Outbreaks of Campylobacteriosis in New Zealand

“…The suggested association of this cluster with recreational water contact is interesting, since C. coli is often associated with water (7,13,19). Pigs and sheep have also been identified to have relatively higher prevalence of C. coli (7).…”

“…Species of Campylobacter can be carried by a range of animal species including farm animals, wild birds, and pets (6,7,9,29) and spread via contaminated food, milk, water, and even flies (11). An increasing awareness has emerged of the importance of, first, identifying Campylobacter to the species level (17) and second, applying appropriate subtyping methodology (35).…”

Campylobacter sequence typing databases: applications and future prospects

“…Two features of Campylobacter infection have hindered investigations into the epidemiology of human campylobacteriosis: (i) human disease is most commonly sporadic (Gormley et al, 2011), and (ii) the bacterium can be readily isolated from intestines of many different animals and environmental sources such as water and soil (Brown et al, 2004). Accurate isolate characterization is consequently essential to this endeavour, but the early application of serological methods, which were effective for typing organisms such as Salmonella, was ineffective for Campylobacter.…”

Merging Wildlife and Environmental Monitoring Approaches with Forensic Principles: Application of Unconventional and Non-Invasive Sampling in Eco- Pharmacovigilance

“…Consequently, the presence of NSAID residues and other relevant harmful compounds -and their persistence in fecal matter -should be better established. Sampling, preservation and study protocols involving feces must reflect that the fecal matter itself and the incorporated compounds could degrade or be modified over time due to weathering by rain and temperature-induced degradation, among other environmental factors [187].…”