Source identification of airborne Escherichia coli of swine house surroundings using ERIC-PCR and REP-PCR

Abstract

Evidence is mounting that microorganisms originating from livestock impact the air quality of the animal houses themselves and the public in the surrounding neighborhoods. The aim of this study was to develop efficient bacterial source tracking capabilities to identify sources of Escherichia coli aerosol pollution caused by pigs. Airborne E. coli were isolated from indoor air, upwind air (10 and 50 m away) and downwind air samples (10, 50, 100, 200 and 400 m away) for five swine houses using six-stage Andersen microbial samplers and Reuter-Centrifugal samplers (RCS). E. coli strains from pig fecal samples were also collected simultaneously. The enterobacterial repetitive intergenic consensus polymerize chain reaction (ERIC-PCR) and the repetitive extragenic palindromic (REP-PCR) approaches were used to study the genetic variability and to determine the strain relationships among E. coli isolated from different sites in each swine house. Results showed that 35.1% (20/57) of the bacterial DNA fingerprints from the fecal isolates matched with the corresponding strains isolated from indoor and downwind air samples (similarity > or = 90%). E. coli strains from the indoor and downwind air samples were closely related to the E. coli strains isolated from feces, while those isolated from upwind air samples (swine house C) had low similarity (61-69%). Our results suggest that some strains isolated from downwind and indoor air originated in the swine feces. Effective hygienic measures should be taken in animal farms to prevent or minimize the downwind spread of microorganism aerosol.

Genetic heterogeneity of Escherichia coli isolated from pasteurized milk in State of Paraná, Brazil

“…Other authors have used ERIC-PCR to compare E. coli isolates from humans and animals (Leung et al, 2004;Sabate et al, 2008;Tramuta et al, 2011;De la Fé Rodriguez et al, 2012). Moreover, Casarez, Pillai, Di Giovanni, (2007), Duan et al (2009), andWan et al (2011) showed that ERIC-PCR could discriminate E. coli from water and environmental samples. Knowledge about the epidemiology of diarrheagenic E. coli in food is important for understanding its distribution and transmission, besides developing and implementing control measures in food production.…”

Use of a culture-independent approach to characterize aerosolized bacteria near an open-freestall dairy operation

“…A decreasing airborne microorganism concentration with increasing downwind distance is the general trend also documented by researchers at CAFOs (Chinivasagam et al, 2010;Dungan et al, 2010;Green et al, 2006). In recent study by Duan et al (2009), airborne E. coli were recovered at distances up to 100 m from swine houses, which were closely related to isolates obtained from indoor air and fecal samples. While the above mentioned studies do suggest a decreased risk for exposure to bioaerosols as distance from the source is increased, some pathogenic microorganisms can be transported long distances (Brown and Hovmøller, 2002;Gloster et al, 1982).…”

Antimicrobial resistance and integrons of ESBL-producing thermotolerant coliforms from a water reservoir in Tai'an, China

“…As described previously, enterobacterial repetitive intergenic consensus sequence polymerase chain reaction (ERIC-PCR) was used to determine clonal relatedness of ESBL-TC [22]. Briefly, amplification was conducted as follows: an initial denaturation (94℃, 5 minutes), followed by 35 cycles of denaturation (94℃, 1 minute), annealing (42℃, 1 minute), and extension (65℃, 8 minutes) with a single final extension (65℃, 16 minutes).…”