High abundance and diversity of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in faeces and tonsils of pigs at slaughter

• Published in: Veterinary microbiology 2017-09, Vol.208, p.190-194
• Main Authors: Van Damme, I., Garcia-Graells, C., Biasino, W., Gowda, T., Botteldoorn, N., De Zutter, L.
• Format: Article
• Language: English
• Subjects: Abundance; Agar; Animals; Anti-Bacterial Agents - pharmacology; Bacteria; beta-Lactamases - metabolism; Bile; Carcasses; Cefotaxime; Cefotaxime resistance; Contamination; Drug Resistance, Bacterial; E coli; Enumeration; Escherichia coli; Escherichia coli - drug effects; Escherichia coli - enzymology; Escherichia coli - metabolism; Escherichia coli Infections - microbiology; Escherichia coli Infections - veterinary; Exposure; Feces; Feces - microbiology; Hogs; Palatine Tonsil - microbiology; Pig; Pork; Slaughter; Studies; Suidae; Swine; Swine Diseases - microbiology; Throat; Tonsil; β Lactamase
• ISSN: 0378-1135; 1873-2542
• DOI: 10.1016/j.vetmic.2017.08.009

•Cefotaxime resistant E. coli (CREC) were studied in 96 pigs during slaughter.•CREC were detected in 75% of faecal samples and 47% of tonsil samples.•Numbers up to 5.5 and 5.6log10 CFU/g were found in faeces respectively tonsils.•Around 1/10,000 E. coli in both faeces and tonsils were cefotaxime-resistant.•Up to 5 different combinations of ESBL genes were found in isolates from one sample. This cross-sectional study investigates the abundance of cefotaxime-resistant Escherichia coli (CREC) in the faeces and tonsils of 96 pigs during slaughter. Moreover, different isolates from a selected number of pigs were tested to study the diversity of blaESBL genes within E. coli isolates from one pig. Cefotaxime-resistant bacteria (based on enumeration results on MacConkey agar supplemented with 1mg/L cefotaxime) were found in the faeces of 77 pigs (80%; 95% CI: 70–87%) and the tonsils of 91 pigs (95%; 95% CI: 88%–98%). Cefotaxime-resistant E. coli (based on enumeration results on Tryptone Bile X-glucuronide agar supplemented with 1mg/L cefotaxime) were detected in 72 faecal samples (75%; 95% CI: 64–83%) and 45 tonsil samples (47%; 95% CI: 35–59%), in numbers up to 5.5 and 5.6log10 CFU/g, respectively. On average, around 1/10,000 E. coli in both faeces and tonsils were cefotaxime-resistant, though large variations were observed between pigs. Within one sample, CREC isolates with up to five different combinations of ESBL genes were observed. In three out of 16 faecal samples and six out of 14 tonsil samples, only one ESBL gene profile was found. The high numbers of CREC that are occasionally found in the faeces and tonsils of pigs during slaughter may represent an important source of contamination of carcasses and subsequently pork.