Extended-spectrum beta-lactamase and AmpC beta-lactamase-producing Enterobacteriaceae in turkey fattening farms: a cross-sectional study

Extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase (AmpC)-producing Enterobacteriaceae are found in companion and farm animals worldwide. For turkeys, however, limited data exist. A cross-sectional study of 48 conventional turkey fattening farms was, therefore, conducted throughout Germany. Rearing as well as fattening flocks within the same farms were studied by investigating pooled faeces, boot swabs and dust samples. In total, 70.8% (34/48) of all farms were positive for ESBL/AmpC-producing Enterobacteriaceae and 60.4% (29/48) for ESBL/AmpC-producing Escherichia coli (E. coli). When comparing the ESBL/AmpC status of rearing and fattening flocks no significant differences were found. The use of antibiotics was documented, however, no obvious impact could be found. The highest detection rates of the resistant bacteria appeared in boot swabs (46.7% for ESBL/AmpC-producing Enterobacteriaceae, 39.1% for ESBL/AmpC-producing E. coli) followed by pooled faeces (38.8% and 30.4%, respectively) and dust samples (25% and 18.5%, respectively). Isolates were tested for common ESBL genes (bla(CTX-M), bla(SHV), bla(TEM)) and CIT-type AmpC beta-lactamase encoding genes including the common bla(CMY-2). Genes encoding for CTX-M type were found most frequent (88.3%, 121/137), with CTX-M-1 most often (41.6%) followed by CTX-M-14 (20.7%), CTX-M-15 (17.3%), CTX-M-32 (7.4%), CTX-M-27 (6.6%) and CTX-M-55 (0.8%). Also other ESBL encoding genes such as SHV-2, SHV-12 and TEM-52 as well as the AmpC beta-lactamase CMY-2 encoding gene were found sporadically. ESBL/AmpC-producing E. coli occur regularly in German turkey fattening farms, however, with lower prevalences compared to other animal species.