Prophylactic application of antibiotics selects extended‐spectrum β‐lactamase and carbapenemases producing Gram‐negative bacteria in the oral cavity

Scientific paper - Original scientific paper

• Author: Vesna Bratić
• Author: Slobodan Mihaljević
• Author: Ž. Verzak
• Author: E. Pleško
• Author: A. Lukić
• Author: M. Ćaćić
• Author: Branka Bedenić
• Author's institution: University of Zagreb; School of Medicine; (Department of Medical Microbiology and Parasitology)
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Clinical Medical Sciences; Medical Microbiology

Abstract (english)

Prophylactic administration of broad-spectrum antibiotics in surgery can change the oral microbiome and induce colonization of oral cavity with Gram-negative bacteria including multidrug (MDR) or extensively drug resistant (XDR) organisms which can lead to lower respiratory tract infections. The aim of the study was to analyse the Gram-negative isolates obtained from oral cavity of the mechanically ventilated patients in ICUs, after prophylactic application of antibiotics and their resistance mechanisms and to compare them with the isolates obtained from tracheal aspirates from the same patients. The antibiotic susceptibility was determined by broth dilution method. PCR was applied to detect genes encoding β-lactamases. Marked diversity of Gram-negative bacteria and resistance mechanisms was found. High resistance rates and high rate of blaCTX-M and carbapenemase encoding genes (blaVIM-1 , blaOXA-48 ) were found among Klebsiella pneumoniae. Pseudomonas aeruginosa was found to harbour blaVIM and in one strain blaPER-1 gene, whereas Acinetobacter baumannii produced OXA-23-like and OXA-24/40-like oxacillinases and was XDR in all except one case. All XDR isolates belong to international clonal lineage II (IC II). The main finding of the study is that the prophlylactic application of antibiotics in surgery intensive care units (ICUs) is associated with the colonization of oral cavity and lower respiratory tract with Gram-negative bacteria. The identity of Gram-negative bacteria in oral cavity reflected those found in endotracheal aspirates leading to conclusion that oral swab as non-invasive specimen can predict the colonization of lower respiratory tract with resistant Gram-negative organisms and the risk for development of ventilator-associated pneumonia.

• Keywords (english): Acinetobacter baumannii / drug effects; Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents / pharmacology*; Antibiotic Prophylaxis*; Bacterial Proteins / genetics; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Gram-Negative Bacteria / drug effects*; Hospitalization; Humans; Intensive Care Units; Klebsiella pneumoniae / drug effects; Microbial Sensitivity Tests; Middle Aged; Mouth / microbiology*; Polymerase Chain Reaction; Pseudomonas aeruginosa / drug effects; Young Adult; beta-Lactamases / genetics
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review
• Publication version: Accepted version
• Journal title: Letters in Applied Microbiology
• Numbering: vol. 73, no. 2, pp. 206-219
• p-ISSN: 0266-8254
• e-ISSN: 1472-765X
• DOI: https://doi.org/10.1111/lam.13493
• URN:NBN: urn:nbn:hr:105:428680
• Publication: 2021-08
• Document URL: https://onlinelibrary.wiley.com/doi/10.1111/lam.13493
• Type of resource: Text
• Access conditions: Open access; Embargo expiration date: 2022-09-01
• Created on: 2021-11-26 09:28:35