TY - JOUR
T1 - Carriage and fecal counts of cefotaxime M-producing Escherichia coli in pigs
T2 - a longitudinal study
AU - Hansen, Katrine Hartung
AU - Damborg, Peter Panduro
AU - Andreasen, Margit
AU - Nielsen, Søren Saxmose
AU - Guardabassi, Luca
PY - 2013/2
Y1 - 2013/2
N2 - Current knowledge on extended-spectrum beta-lactamases (ESBLs) in animals is based largely on cross-sectional studies and qualitative data. The aim of this longitudinal study was to elucidate carriage proportions and fecal counts of ESBL-producing Escherichia coli in pigs during the production cycle. At each of three ESBL-positive single-sited farrow-to-finisher pig farms (farms A, B, and C) included in the study, individual fecal samples were taken from 17 to 20 sows 1 week before farrowing and from 2 piglets of each sow's litter four times from birth to slaughter (as piglets, weaners, and finishers). Cefotaxime (CTX)-resistant coliforms in feces were counted on MacConkey agar containing 2 μg/ml CTX and characterized for the presence of ESBLencoding genes by PCR and sequencing. CTX-M-positive pigs were detected in all age groups at farms A (blaCTX-M-9 group, compatible with blaCTX-M-14/17) and B (blaCTX-M-1 group, compatible with blaCTX-M-1/61), whereas only three weaners were positive at farm C (blaCTX-M-1 group, compatible with blaCTX-M-1/61). A significant decrease in carriage was detected during the production cycle, with on average 50% carriage immediately after birth, 58% just before weaning, 29% during weaning, and 12% during finishing. The observed reduction in numbers of CTX-M-positive pigs was accompanied by a significant reduction in mean fecal counts of CTX-resistant coliforms from~107 CFU/g in piglets to~103 CFU/g in finishers (P<0.001). These findings provide novel information about the epidemiology of ESBLs at the farm level and have important implications for assessments of risks of meat contamination during slaughter.
AB - Current knowledge on extended-spectrum beta-lactamases (ESBLs) in animals is based largely on cross-sectional studies and qualitative data. The aim of this longitudinal study was to elucidate carriage proportions and fecal counts of ESBL-producing Escherichia coli in pigs during the production cycle. At each of three ESBL-positive single-sited farrow-to-finisher pig farms (farms A, B, and C) included in the study, individual fecal samples were taken from 17 to 20 sows 1 week before farrowing and from 2 piglets of each sow's litter four times from birth to slaughter (as piglets, weaners, and finishers). Cefotaxime (CTX)-resistant coliforms in feces were counted on MacConkey agar containing 2 μg/ml CTX and characterized for the presence of ESBLencoding genes by PCR and sequencing. CTX-M-positive pigs were detected in all age groups at farms A (blaCTX-M-9 group, compatible with blaCTX-M-14/17) and B (blaCTX-M-1 group, compatible with blaCTX-M-1/61), whereas only three weaners were positive at farm C (blaCTX-M-1 group, compatible with blaCTX-M-1/61). A significant decrease in carriage was detected during the production cycle, with on average 50% carriage immediately after birth, 58% just before weaning, 29% during weaning, and 12% during finishing. The observed reduction in numbers of CTX-M-positive pigs was accompanied by a significant reduction in mean fecal counts of CTX-resistant coliforms from~107 CFU/g in piglets to~103 CFU/g in finishers (P<0.001). These findings provide novel information about the epidemiology of ESBLs at the farm level and have important implications for assessments of risks of meat contamination during slaughter.
U2 - 10.1128/AEM.02399-12
DO - 10.1128/AEM.02399-12
M3 - Journal article
C2 - 23160131
SN - 0099-2240
VL - 79
SP - 794
EP - 798
JO - Applied and Environmental Microbiology
JF - Applied and Environmental Microbiology
IS - 3
ER -