RESUMEN
This study aims to investigate the development of secondary bacterial infection and risk factors associated with it in critical COVID-19 patients, and to identify the most common pathogen groups in them. All the cohort studies were retrieved from Scopus, Google Scholar, Web of Science, and MEDLINE from the inception of COVID-19 to 2022 for the following keywords: 'Klebsiella" AND "COVID-19". The most common comorbidities among the patients with COVID-19 were respiratory disease (33.62%), obesity (28.99%), and heart disease or cardiovascular disease (16.31%). We report 42.91% rate of Klebsiella spp co-infection in ICU admission patients, mostly related to K. pneumonia (26.81%), K. aerogenes (9.4%), and K. oxytoca (6.7%). The overall incidence of bacterial infection in hospitalized COVID-19 patients is estimated at 15.5% and in 32.5% of cases of co-infection patients deceased. The threat of carbapenem-resistant K. pneumoniae infections in patients with COVID-19 is imminent, therefore rational antibiotic therapy based on antibiotic sensitivity test should be implemented.