Frecuencia y resistencia de Staphylococcus aureus a betalactámicos en pacientes de El Pangui, Zamora Chinchipe, Ecuador

Abstract

Introduction. The golden staphylococcus, Staphylococcus (S.) aureus, is a Gram-positive, pathogenic, and opportunistic bacterium whose resistance to β-lactams represents a global public health challenge. It is considered one of the most serious threats to public health and is the leading cause of bacterial mortality in 135 countries. Objective. The study aimed to determine the frequency of S. aureus and its β-lactam antibiotic resistance among ambulatory patients in the El Pangui Canton and to assess the distribution by sex and age. Materials and methods. A cross-sectional study using non-probabilistic convenience sampling was conducted, analyzing 422 oropharyngeal samples (the oropharynx is the oral cavity, located between the mouth and the pharynx). These samples were processed through a blood agar culture, biochemical tests for catalase and coagulase, Gram staining, and antibiotic susceptibility testing using the Kirby–Bauer disk diffusion method. Statistical analysis included the Chi-square test and the Odds Ratio, with a 95% confidence interval. Results. The frequency was 23% (96 of 422 patients); 66% (63 of 96) of the isolates were β-lactam-resistant, and 51% (32 of 63) exhibited simultaneous resistance. No significant association was found between frequency or resistance and sex or age (p > 0.05). Conclusions. The results showed a considerable frequency of S. aureus in oropharyngeal samples. This bacterium exhibited resistance to beta-lactam antibiotics, primarily penicillin, oxacillin and ceftriaxone. This finding confirms the studied community as a significant reservoir of the pathogen and highlights the risk of transmission, underscoring the importance of epidemiological surveillance.