Oral colonization of Acinetobacter baumannii in intensive care units: Risk factors, incidence, molecular epidemiology, association with the occur of pneumonia and sepsis, and infection control measures

Objective(s): Oral colonization of Acinetobacter baumannii can lead to infections such as pneumonia and sepsis. We aimed to evaluate oral colonization of hospitalized patients in ICUs and to examine risk factors for oral colonization, molecular epidemiology, and incidence of pneumonia and sepsis. Materials and Methods: The study began in February 2021. Oral cultures were taken. The microorganisms were identified by a Maldi-tof MS mass spectrometry device. Colistin resistance genes were investigated by polymerase chain reaction. Clonal relationships were determined by pulsed-field gel electrophoresis. Results: A. baumannii was found in 21 of 96 patients' oral cultures. Pneumonia and sepsis due to A. baumannii were detected in 14 and 5 patients, respectively. The mean growth time of A. baumannii from oral cultures was 11.8 days, and the meantime for the occurrence of pneumonia after oral growth was 5.2 days. We determined a plasmid mediated mcr-2 colistin resistance gene in a colistin susceptible A. baumannii strain. It is the first report of the plasmid mediated mcr-2 colistin resistance gene in our country. In total, fourteen different A. baumannii genotypes were determined in PFGE. It was determined that the effects of antibiotic use, oral motor dysfunction, mechanical ventilation, intubation, orogastric tube use, and total parenteral nutrition intake on oral colonization were statistically significant. Conclusion: Oral colonization of A. baumannii is a significant concern in ICUs. We believe that it is important to take oral cultures and follow the risk factors and take infection control measures to prevent oral colonization of resistant isolates in ICUs.

Automated summary

This study aimed to evaluate the oral colonization of Acinetobacter baumannii in ICU patients and investigate the associated risk factors, molecular epidemiology, and incidence of pneumonia and sepsis. The results showed that A. baumannii was detected in the oral cultures of 21 out of 96 patients. Pneumonia and sepsis caused by A. baumannii were found in 14 and 5 patients, respectively. The presence of plasmid-mediated mcr-2 colistin resistance gene in a colistin susceptible A. baumannii strain was also identified. The findings highlight the significance of oral colonization of A. baumannii in ICUs and emphasize the need for infection control measures to prevent the colonization of resistant isolates.