Background/Objectives: Antibiotic resistance is a serious public health problem threatening the treatment of infectious diseases caused by Escherichia coli, the main source of food contamination and responsible for many infectious diseases with high indices of AR profiles. Our objective was to study the presence of Escherichia coli in foods that are distributed and prepared on the street, characterizing its sensitivity profile and resistance to antibiotic drugs commonly prescribed in this geographical area. Methods: Standard procedures were performed to identify and isolate E. coli colonies from food samples collected during a three-year study. Susceptibility assays were conducted to determine the antibiotic resistance profile, and Colony PCR assays were performed to determine the pathogenic and antibiotic resistance genes. Results: A total of 189 food samples were collected, and 100% of the samples were positive for E. coli, with higher percentages of contamination for vegetables and fruits. ETEC (lt) and UPEC (vat, cnf1, hylA) genes were identified in 100% of the samples and DAEC (afa) in 27%. E. coli exhibited high percentages of resistance against ampicillin and amoxicillin/clavulanic acid (100%) and cephalexin (45%). The most effective antibiotics were tetracycline, TMP-SMX, polymyxin, and quinolones. The AR genes tetA, sul1, catA1, strA, qnrS, and floR were identified among the samples. Conclusions: Food prepared and marketed on the streets seriously threatens human health. Ampicillin and amoxicillin/clavulanic acid should not be used to treat infections caused by the multidrug-resistant ETEC and UPEC identified in this area. To our knowledge, this is the first study that explores the status of AR in this geographical area.

Background: Antibiotic drug resistance is a serious global health problem that threatens therapeutics against infectious diseases. As antibiotics become less effective every year, our objective was to evaluate the adjuvant activity of methanolic extracts of Moringa oleifera seed combined with antibiotics of clinical use against multidrug-resistant Escherichia coli isolated from street food samples searching for a new alternative to treat infectious diseases commonly treated with antibiotics. Methods: Secondary metabolites of M. oleifera seeds were obtained through maceration (methanol 80%) and detected following qualitative phytochemical assays. MIC, MBC and tolerance level were determined using microdilution tests. Antimicrobial activity was tested by sensitivity analysis, and the adjuvant activity was explored in combination with twelve antibiotics against the E. coli samples. Results: Alkaloids, phenolic compounds, flavonoids, and polyphenols were detected. MIC and MBC values ranged from 31.3 to 62 mg/mL and 62–125 mg/mL, respectively. The extract showed low antimicrobial activity against the multidrug-resistant E. coli, but the inhibitory capacity of ampicillin, cephalexin, and amoxicillin/clavulanic acid was significantly increased when combined with the plant extract. In contrast, the activity of ciprofloxacin, levofloxacin, tetracycline, polymyxin, and nalidixic acid decreased with the extract. Conclusion: Methanolic extracts of M. oleifera seeds represent a potential adjuvant for beta-lactams in the face of the growing problem of global antimicrobial resistance. This study represents the first steps in exploring the adjuvant capacity of plants against resistant environmental pathogens in Mexico.