Analysis of drug resistance of food-borne Escherichia coli in Nanyang region of Henan Province

AIM: To explore the drug resistance of food-borne Escherichia coli (E. coli).

METHODS: The sensitivity of 288 E. colistrains isolated from 122 chicken, ready-to-eat food and other meat samples to ciprofloxacin (Cip), nalidixic acid (Nal), gentamicin (Gen), kanamycin (Kan), amikacin (Amk), streptomycin (Str), ampicillin (Amp), amoxicillin (Amx), cefoperazone (Cfp), cefoxitin (Cfx), chloramphenicol (Chl), and tetracycline (Tet) was determined. The drug resistance and drug-resistant multiplicity for E. coli strains from different sources were compared.

RESULTS: The rate of resistance to Tet was the highest (95.83%), and the most sensitive drug was Amk (8.68%). The rates of resistance to Tet were the highest for the bacteria from chicken, ready-to-eat food and other meat samples (99.34%, 96.30%, 89.02%), while the most sensitive drug was Cfx for the bacteria from chicken samples (15.13%) and Amk for the bacteria from ready-to-eat food and other meat samples (0.00%, 0.00%). Except for Tet, the rates of resistance to other 11 drugs for the bacteria from chicken samples were higher than those for the bacteria from ready-to-eat food and other meat samples (74.34% vs 25.93%, 77.63% vs 38.89%, 15.13% vs 11.11%, 40.13% vs 1.85%, 47.37% vs 7.41%, 53.95% vs 1.85%, 16.45% vs 0.00%, 65.13% vs 1.85%, 87.50% vs 14.81%, 67.11% vs 3.70%, 79.61% vs 48.15%, 74.34% vs 31.71%, 77.63% vs 37.80%, 15.13% vs 7.32%, 40.13% vs 3.66%, 47.37% vs 12.20%, 53.95% vs 15.85%, 16.45% vs 0.00%, 65.13% vs 7.32%, 87.50% vs 23.17%, 67.11% vs 4.88%, 79.61% vs 42.68%, P < 0.05). The bacteria isolated from chicken and ready-to-eat food samples were resistant to at least one agent. The bacteria isolated from other meat samples were sensitive to all of the 12 kinds of antibiotics. TheE. coli strains separated from chicken samples were mainly resistant to 9 (28 strains), 10 (23 strains) and 8 (20 strains) agents; those separated from ready-to-eat food samples were mainly resistant to 1 agent (15 strains), 2 (24 strains) and 3 agents (9 strains); those separated from other meat samples were mainly resistant to 1 agent (32 strains), 2 (15 strains) and 6 (11 strains) agents. The results showed that the drug resistance of E. coli strains separated from chicken were higher than that of E. coli strains separated from ready-to-eat food and other meat samples.

CONCLUSION: E. coli contamination occurred in the meat and ready-to-eat food samples tested. The rate of resistance of food-borne E. coli to Tet is the highest, and the most sensitive drug is Amk. The condition of multidrug resistance of E. coli strains from food samples, especially chicken, is serious.