Cutaneous Microbiota at the General Hospital of Zone No. 3, Navojoa, Sonora (2022–2025)

The use of topical antibiotics is a common practice in dermatology; however, their impact on the cutaneous microbiota and the risk of antimicrobial resistance remains a concern. The objective of this study was to evaluate the changes in the cutaneous microbiota associated with the use of topical antibiotics in patients treated at the General Hospital of Zone No. 3 in Navojoa, Sonora, between 2022 and 2025. A retrospective analysis of microbiological cultures obtained before and after treatment was conducted, recording demographic data, type of antibiotic used, changes in microbial composition, and resistance patterns. A total of 100 patients were included. Those who received topical antibiotics showed a decrease in microbiota diversity (from 100% to 72%) and an increase in the isolation of Staphylococcus aureus after treatment (from 28% to 52%), in addition to an increase in antimicrobial resistance, which rose from 20% to 40%. In contrast, the group without antibiotic treatment maintained a stable commensal flora and a low frequency of resistant microorganisms. These findings suggest that topical antibiotics can significantly alter the cutaneous ecosystem and promote the emergence of resistant pathogens, emphasizing the need to strengthen rational antimicrobial use policies in dermatology and to develop prospective studies to better understand their long-term effects.