Open Access1014. Effect of Levofloxaclin and Trimethoprim-sulfamethoxazole on Planktonic and Biofilm Cells of Stenotrophomonas maltophilia Isolates Obtained from Blood and Respiratory Samples
Author(s) -
José Mauricio Del Río-Chacón,
Fabián RojasLarios,
Verónica Villarreal-Salazar,
Paola Bocanegra Ibarías,
Oscar Newton-Sánchez,
Adrián Camacho-Ortíz,
Samantha Flores-Treviño
Publication year - 2021
Publication title -
open forum infectious diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.546
H-Index - 35
ISSN - 2328-8957
DOI - 10.1093/ofid/ofab466.1208
Subject(s) - stenotrophomonas maltophilia , biofilm , microbiology and biotechnology , sulfamethoxazole , levofloxacin , trimethoprim , medicine , antibiotics , antimicrobial , bacteria , biology , pseudomonas aeruginosa , genetics
Background Stenotrophomonas maltophilia is a non-fermenting Gram-negative pathogen, which causes healthcare-associated infections and exhibits increasing drug resistance rates. In this study, we compared the effect of levofloxacin and trimethoprim-sulfamethoxazole on planktonic and biofilm cells of S. maltophilia isolates obtained from blood and respiratory samples. Methods S. maltophilia isolates were recollected from patients older than 18 years from 2018-2020 from Hospital Universitario Dr. Jose Eleuterio Gonzalez, a tertiary care hospital from Nuevo Leon, Mexico. Bacteria were dentified by MALDI-TOF MS. Biofilm formation was determined using the crystal violet staining method.Antimicrobial susceptibility in planktonic cells and biofilm cells were determined by the broth microdilution and the Calgary device, respectively. Results During the 3-year study period, 44 S. maltophilia isolates were identified, 28.8% of which were biofilm producers. Of those, 69.2% were obtained from blood cultures. Isolates were obtained from several wards: 25% infectious diseases ward, 18% nephrology, 18% intensive care units, 14% geriatric ward, 7% plastic surgery, and 18% from other wards. The majority of the studied subjects were men (34.6%), and the mean age was 41 years. The majority of the isolates were susceptible to levofloxacin (94.1%) and to trimethoprim-sulfamethoxazole (76.4%) in planktonic assays. All the isolates were resistant to both antibiotics when analyzing biofilm cells. Levofloxacin resistance was at least four-fold higher in biofilm cells compared to planktonic cells. Trimethoprim-sulfamethoxazole resistance was at least ten-fold higher in biofilm cells compared to planktonic cells. Conclusion The majority of S. maltophilia clinical isolates causing blood infections in a hospital in Mexico were able to produce biofilm. The production of biofilm in S. maltophilia strains enhanced resistance to levofloxacin and trimethoprim-sulfamethoxazole. Disclosures All Authors: No reported disclosures