Diversity, Antibiotic Resistance, and Biofilm-Forming Ability of Enterobacteria Isolated from Red Meat and Poultry Preparations

A total of 44 samples of beef, pork, and poultry preparations were tested. Average counts (log cfu/g) of enterobacteria were 1.99 &plusmn
0.99 (beef preparations), 1.96 &plusmn
1.44 (pork), 2.09 &plusmn
0.92 (chicken), and 2.17 &plusmn
1.06 (turkey) (p &gt
0.05). Two hundred enterobacterial strains were identified and 13 genera (21 species) were distinguished, including species that are a significant cause of infection. The most common genera were Escherichia (32.5% of strains), Serratia (17.0%), Hafnia (12.5%), and Salmonella (12.0%). Isolates were screened by disc diffusion for susceptibility to 15 antibiotics. A total of 126 strains (63% of the isolates) were multirresistant (having resistance to two or more antibiotics), 46 (23%) were resistant to one antibiotic, and 28 (14%) were sensitive to all antibiotics. The average number of resistances per strain was 2.53 &plusmn
2.05. A higher (p &lt
0.05) average number of resistances was observed in strains from turkey (3.14 &plusmn
2.55) than in strains from beef (2.15 &plusmn
1.22), pork (2.16 &plusmn
1.39), or chicken (2.44 &plusmn
2.22). At least 50% of strains showed resistance or reduced susceptibility to ampicillin, cefotaxime, ceftazidime, or streptomycin, considered to be &ldquo
critically important&rdquo
antimicrobial agents in human medicine. Seventy-nine strains (39.5%), 60 strains (30.0%), and 46 strains (23.0%) were weak, moderate, and strong biofilm producers (crystal violet assay), respectively. This investigation provides evidence that bacteria from red meat and poultry preparations pose major potential risk to consumers.