Comparing the Biofilm Formation Properties of S. Maltophilia Isolates Obtained From the Pulmonary and Extrapulmonary Samples

Abstract

Objective: Stenotrophomonas maltophilia is commonly a nosocomial pathogen with multiple drug resistance, although it has been reported in communityacquired infections. Trimethoprim-sulfamethoxazole is prefered as the first antibiotic in the treatment of S. maltophilia infections. In hospitalized patients, the respiratory tract is the body area that it is most frequently isolated. Although it is known about the bacteria that it causes the formation of biofilms due to its ability to attach to plastic surfaces, relatively little is known in terms of virulence factors. The aim of our study is to compare the property of biofilm formation of pulmonary and extrapulmonary isolates of S. maltophilia. Methods: A total of 78 S. maltophilia isolates isolated from 37 pulmonary and 41 extrapulmonary specimens were included in the study. The identfication of the isolates were performed in Vitek MS (bioMérieux, Fransa) automated system. In addition, antibiotic susceptibility was tested using the disc diffusion method. All isolates were investigated for biofilm formation by microtitration plate method. The relation of the pulmonary or extrapulmonary specimens with the biofilm formation was statistically investigated. Results: All of the isolates were found susceptible to trimetoprim-sulphametaxozole. Biofilm formation was detected in 68 of 78 (87.2%) S. maltophilia isolates. Biofilm formation of S. maltophilia isolates that isolated from pulmonary and extrapulmonary specimens were detected as 35/37 (94.6%), 33/41 (80.5%), respectively. There was no statistical relationship between pulmonary or extrapulmonary samples and biofilm forming capability. Conclusion: It was observed that a significant part (87.2%) of all strains included in the study were formed biofilms. It was seen that the biofilm activity of the pulmonary specimens was proportionally higher than extrapulmonary specimens. However, there was no significant difference in terms of biofilm formation between the strains isolated from pulmonary and extrapulmonary specimens. It was also detected that there was no development of resistance to trimethoprimsulfamethoxazole. New comprehensive studies on this subject may contribute to a better understanding of the virulence mechanisms of S. maltophilia. © 2021. All Rights Reserved.