Prevalence of multidrug-resistant phenotypes and antimicrobial resistance patterns in community-acquired respiratory pathogens in the Peruvian highlands during the cold season

Abstract

Background: The Andean cold season (friaje) increases the incidence of acute respiratory infections (ARIs), thereby increasing the risk of antimicrobial resistance (AMR) due to inappropriate antibiotic use. This study aimed to determine the prevalence of multidrug-resistant phenotypes and characterize AMR patterns in community-acquired respiratory pathogens among residents of the Peruvian highlands during the 2025 cold season.

Methods: An observational cross-sectional study was conducted in Huancayo, Peru (3,250 masl). Through non-probabilistic convenience sampling, 100 oropharyngeal swabs were collected from symptomatic patients. Isolates were identified using selective media, and susceptibility was assessed via the Kirby-Bauer disk diffusion method per CLSI M100 guidelines. Data on self-medication and treatment adherence were gathered through structured questionnaires. Statistical analyses, including Chisquare and Fisher’s exact tests (p < 0.05), were performed using IBM SPSS v.29.0. The protocol was approved by the UNCP Ethics Committee (Code: CEI–UNCP–N° 064–2025).

Results: Mixed microbiota was identified in 68% of samples. Primary pathogens included Haemophilus influenzae (11%), Staphylococcus aureus (10%), and Streptococcus pneumoniae (4%). Klebsiella pneumoniae and Pseudomonas aeruginosa were isolated, posing a risk for multidrug resistance (MDR). Although high rates of selfmedication (51.9%) and treatment non-adherence (48.1%) were observed among carriers of resistant isolates, no statistically significant association with AMR was found (p > 0.05).

Conclusion: The detection of key respiratory pathogens with high AMR potential during the Andean friaje represents a significant public health challenge. These findings underscore the necessity for localized microbiological surveillance and targeted educational interventions to optimize antibiotic stewardship in vulnerable high-altitude populations.