ANTIMICROBIAL RESISTANCE PROFILE OF BACTERIAL ISOLATES FROM VENTILATOR-ASSOCIATED PNEUMONIA PATIENTS IN AN ECUADORIAN TERTIARY HOSPITAL.

Ventilator-associated pneumonia is one of the most common nosocomial infections in patients receiving mechanical ventilation for more than 48 hours. This study aimed to characterize the antimicrobial susceptibility profile of microorganisms isolated from patients with Ventilator-associated pneumonia in a hospital in Ecuador. A descriptive, retrospective, cross-sectional study was conducted between April 2020 and April 2021. A total of 132 positive bronchial secretion samples obtained from patients diagnosed with VAP were analyzed. Bacterial identification was performed using the Phoenix M50 automated system, and antimicrobial susceptibility testing was carried out according to Clinical and Laboratory Standards Institute guidelines. Isolates resistant to meropenem were further evaluated by phenotypic methods and molecular confirmation of the blaKPC gene. The study period coincided with the COVID-19 pandemic, during which a substantial proportion of ICU admissions were related to severe SARS-CoV-2 pneumonia requiring prolonged mechanical ventilation. Klebsiella pneumoniae was the predominant pathogen (61.4%), including 33 extended-spectrum β-lactamase producing strains and 42 KPC-producing isolates. In Escherichia coli, the ESBL phenotype predominated, and one KPC-producing isolate was identified. KPC-producing strains were also detected in Enterobacter cloacae and Klebsiella aerogenes, with molecular confirmation of the blaKPC gene. The high prevalence of multidrug-resistant pathogens, together with the pandemic context and the associated high mortality, highlights the urgent need to strengthen microbiological surveillance, infection control measures, and therapeutic strategies in intensive care units.