European Antimicrobial Susceptibility Surveillance in Animals (EASSA): Results (2002/2003) for enteric bacteria from healthy cattle, pigs and chickens from 8 countries

Abstract number: 1732_20

Simjee S., de Jong A., McConville M., Bywater R., Chaton-Schaffner M., Deroover E., Klein U., Shryock T., Simmons R., Smets K., Stewart F., Thomas V., Valle M., Marion H.

Objectives: Antimicrobial susceptibility to human-use antibiotics was investigated among the commensal bacteria E. coli (Ec) and Enterococcus spp. (Ent) from healthy food animals at slaughter across the EU.

Methods: Colon or caecal content was randomly collected at 4 abattoirs per country (n = 5 per host). Each herd/flock was sampled once. Ec and Ent were isolated using standard methods. Antibiotic susceptibility testing was done by agar dilution (CLSI, M31-A2) against 9 (Ec) and 5 (Ent) antibiotics in a central laboratory. Resistance (CLSI, M100-S16) was assessed per drug/organism/country.

Results: A total 1465 Ec were recovered (cattle n = 490, pigs n = 494, chickens n = 481). Mean resistance (%) for Ec was: ampicillin (A) 3, 29, 53; cefepime 0, 0, 0; cefotaxime 0, 0, 0.4; ciprofloxacin 1, 0.4, 6; chloramphenicol 2, 16, 15; colistin 0, 0.4, 0; gentamicin (G) 1, 2, 2; tetracycline 8, 66, 65; and trimethoprim-sulfamethoxazole 4, 42, 52 respectively. For Ec, Italy and Spain consistently showed the highest resistance; Denmark showed the lowest. A total of 718 Ent isolates were recovered, comprising 356 E. faecium, 83 E. faecalis and 279 other species including E. durans, E. hirae and E. casseliflavus. All Ent but one bovine isolate, were susceptible to linezolid. For E. faecium resistance to A and G was 0–2%; vancomycin (V) resistance amounted to 1.9 to 3.5%, whereas resistance to quinupristin/dalfopristin (Q/D) combination varied: 8% (cattle), 19% (pigs) and 20% (chickens). Though low prevalence of E. faecalis limited conclusions, particularly in chickens (n = 6), G and V resistance was low in cattle and pigs (0–11%), resistance to Q/D was very high (46 and 83%, respectively). In the other Ent species, resistance among the 3 hosts to G and V was low (0–1.6%). Resistance to A was absent except in chickens: 9.8%. Q/D resistance was among the highest: 5–9% for livestock hosts; 26% in poultry. Striking differences among countries were absent for Ent.

Conclusion: This pan-EU survey, with uniform methodology, shows that antimicrobial resistance among enteric commensal bacteria at slaughter was variable. For Ec, prevalence of antimicrobial resistance varied for older antimicrobials and between countries but resistance to newer medically important antimicrobials was absent or very low. With respect to Ent, antimicrobial resistance rates varied for quinupristin/dalfopristin, but resistance was absent or very low for other antimicrobials including linezolid and vancomycin.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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