Microbiological Quality and Analysis of Escherichia coli Resistance to Antibiotics in Beaches: Evaluating Anthropic Influence in Surface Waters in Brazil

ABSTRACT Antimicrobial resistance is a problem for public health. We sought to assess the multiple antibiotic resistance analyses by searching for resistant microorganisms in five Brazilian beaches. The analyses showed pH (5.2–8.5), temperature (21.2°C–27.5°C), and dissolved oxygen (DO) (4.0–8.5 mg L −1 ). Bacterial indicators peaked during the high season, notably at Beach 5 (4.60 × 10 2 ± 1.71 × 10 2 MPN.100 mL −1 ), although Beaches 1 ( p 0.056) and 2 ( p 0.097) showed significant seasonal coliform variation ( p < 0.10). Overall, 83.3% of isolated Escherichia coli strains were resistant to at least one antibiotic, mainly strains resistant to imipenem (45.0%) and cefazolin (35.0%). Multivariate analysis explained 86.70% of the variance, which resulted in high antibiotic resistance index‐IRAp (e.g., IRAp Beach5 0.818, IRAp Beach1 0.273) and multiple antibiotic resistance (MAR Beach2 = 0.60). Significant anthropogenic pressure‐driven by untreated wastewater, proximity to the continent, ports, industrial complexes, and overpopulation contributed to the proliferation of resistant microorganisms, whereas rainfall leakage contributed to resilience in the area.