Survival and retention ofEschenchia coliO157:H7 andCampylobacterin contrasting soils from the Toenepi catchment

Abstract

The effect of soil type on transfer of zoonotic bacteria to rural streams was investigated using intact cores and turfs of Topehaehae gley soil and Kereone sandy loam. Simulated farm dairy effluent, containing laboratory grown Escherichia coli O157:H7 and Campylobacter, was added to cores and turfs that were stored at 10°C. Bacterial survival was measured in cores over 28 days. Simulated rainfall was applied at 25 and 50 mm h -1 to allow measurement of bacterial transfer to drainage (over 28 days) or surface runoff (at 7 days). Although both bacteria survived for 28 days, Campylobacter declined faster than E. coli O157:H7 with no differences identified for soil type. For Topehaehae soil there was little change in retention of E. coli O157:H7 over the 28 days for both rainfall rates, but there was an increase in retention over time for Kereone. In contrast there was an increase in retention of Campylobacter in both soils at either of the rainfall rates. When surface runoff was measured, less than 1% of each of the applied bacteria was recovered from either soil irrespective of rainfall rate. These findings suggest that rainfall will transfer faecal bacteria from gley soils bordering a stream to the water for at least 28 days after deposition.

Diversity and relatedness of Shiga toxin-producingEscherichia coliandCampylobacter jejunibetween farms in a dairy catchment

“…PFGE was used in this study to explore the genetic diversity of E. coli O26 isolates and their spatial separation or relatedness from separate farms. Water may represent an important transmission source for a number of zoonotic pathogens including STEC which have previously been isolated from various water sources in New Zealand [39]. Although our study did not have the power to explore the population structure of STEC between farms in detail, our data are consistent with a previous molecular epidemiological investigation of 163 STEC O157 isolates that indicated isolates from the same farms had similar molecular profiles compared to isolates from different farms indicating limited transmission of STEC O157 between farms [40].…”

Environmental monitoring of waterborne Campylobacter: evaluation of the Australian standard and a hybrid extraction-free MPN-PCR method

“…However, environmental sources, such as water used for recreational purposes and stormwater flows, represent an often overlooked source of disease transmission (Adak et al, 1995 ; Pond, 2005 ; Arnone and Walling, 2007 ); 3% of confirmed cases in the UK were reported as the direct result of contact with contaminated water supplies (Anonymous, 2000 ). Campylobacter survival within non-biological settings (i.e., water and soils) (Thomas et al, 1999 ; Ross and Donnison, 2006 ; Donnison and Ross, 2009 ; Rodríguez and Araujo, 2012 ), is dependent on numerous exogenous variables. Sensitivities to seasonal variations, temperature, sunlight exposure and dissolved nutrients have been observed to directly affect concentrations of the bacterium within water sources (Jones, 2001 ; Boyle et al, 2008 ; Maal-Bared et al, 2012 ; Rodríguez and Araujo, 2012 ).…”

Modeling the interannual variability of microbial quality metrics of irrigation water in a Pennsylvania stream

“…3a and 4, Chandrasekaran et al, 2015). Intense precipitation increases surface runoff and enhanced transport of indicator bacteria from pasture to streams (Castillo et al, 2004;Donnison and Ross, 2009;Liu et al, 2013).…”