Assessment of Prevalence and Diversity of Antimicrobial Resistant <i>Escherichia coli</i> from Retail Meats in Southern California

• Main Authors: Katie Yen Lee (Author), Kurtis Lavelle (Author), Anny Huang (Author), Edward Robert Atwill (Author), Maurice Pitesky (Author), Xunde Li (Author)
• Format: Book
• Published: MDPI AG, 2023-04-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/antibiotics12040782; 2079-6382
• Keywords: <i>Escherichia coli</i>; antimicrobial resistance (AMR); retail meat; phenotype; whole-genome sequencing (WGS); resistance genes; Therapeutics. Pharmacology; RM1-950
• Source: Antibiotics, Vol 12, Iss 4, p 782 (2023)

Retail meat products may serve as reservoirs and conduits for antimicrobial resistance, which is frequently monitored using <i>Escherichia coli</i> as indicator bacteria. In this study, <i>E. coli</i> isolation was conducted on 221 retail meat samples (56 chicken, 54 ground turkey, 55 ground beef, and 56 pork chops) collected over a one-year period from grocery stores in southern California. The overall prevalence of <i>E. coli</i> in retail meat samples was 47.51% (105/221), with <i>E. coli</i> contamination found to be significantly associated with meat type and season of sampling. From antimicrobial susceptibility testing, 51 isolates (48.57%) were susceptible to all antimicrobials tested, 54 (51.34%) were resistant to at least 1 drug, 39 (37.14%) to 2 or more drugs, and 21 (20.00%) to 3 or more drugs. Resistance to ampicillin, gentamicin, streptomycin, and tetracycline were significantly associated with meat type, with poultry counterparts (chicken or ground turkey) exhibiting higher odds for resistance to these drugs compared to non-poultry meats (beef and pork). From the 52 <i>E. coli</i> isolates selected to undergo whole-genome sequencing (WGS), 27 antimicrobial resistance genes (ARGs) were identified and predicted phenotypic AMR profiles with an overall sensitivity and specificity of 93.33% and 99.84%, respectively. Clustering assessment and co-occurrence networks revealed that the genomic AMR determinants of <i>E. coli</i> from retail meat were highly heterogeneous, with a sparsity of shared gene networks.