DOI: 10.5061/dryad.vq83bk3zw
title: Biofilm formation and plasmid-mediated quinolone resistance genes at varying quinolone inhibitory concentrations in quinolone-resistant bacteria superinfecting COVID-19 inpatients

description: The likelihood of treatment failure in COVID-19 patients with bacterial
 superinfection stems from phenotypic, viz., biofilms, and genotypic
 mechanisms. This cross-sectional study aimed to determine the inhibitory
 concentrations of quinolones—nalidixic acid, norfloxacin, ciprofloxacin,
 ofloxacin, and levofloxacin—in biofilm formers [minimum biofilm inhibitory
 concentration (MBIC)] and non-formers [minimum inhibitory concentration
 (MIC)] as well as correlate the quinolones’ folds with the presence of
 plasmid-mediated quinolone-resistance (PMQR) genes in quinolone-resistant
 bacteria isolated from COVID-19 inpatients. Quinolone-resistant isolates
 (n=193), verified through disc diffusion, were tested for quinolone
 inhibitory concentrations and biofilm formation with broth microdilution
 and microtiter plate methods, respectively. Polymerase chain reaction was
 used to detect PMQR genes. MIC to MBIC median increase in folds for
 ciprofloxacin, ofloxacin, and levofloxacin was 128 (2-8,192), 64
 (4-1,024), and 32 (4-512) in gram-positive cocci (GPC), respectively,
 while it was 32 (4-8,192), 32 (4-2,048), and 16 (2-1,024) in
 fermentative-gram-negative bacilli (F-GNB), and 16 (4-4,096), 64 (2-64),
 and 16 (8-512) in non-fermentative-gram-negative bacilli (NF-GNB).
 Biofilm-forming F-GNB (32/126) and NF-GNB (10/24)
 harbored qnrB [11/32 versus (vs.)
 3/10], aac(6')-Ib-cr (10/32 vs. 4/10),
 and qnrS (9/32 vs. 0/10) genes, respectively. A 32-fold
 median increase in ciprofloxacin was significantly associated
 with qnrA and qnrS in F-GNB and
 NF-GNB, respectively. F-GNB and NF-GNB biofilms were significantly
 associated with aac(6')-Ib-cr and qnrS genes,
 respectively. Nearly one-third of the superinfecting bacteria in
 COVID-19 patients formed biofilms, and had at least one PMQR gene,
 increasing the need for quinolone inhibitory concentrations.
description: Data on patients' demographics and laboratory findings,
 including microbiological analyses, were obtained using patient
 information sheets. Any missing or unclear records were clarified by
 communicating with involved healthcare professionals, patients, or
 families using the phone numbers listed in the patient information sheet.
 Subsequently, the study variables were recorded in Microsoft Excel,
 version 10.0. The patient information sheet data was
 entered into Microsoft Excel version 10.0. The extracted data was imported
 into Statistical Package for Social Science (SPSS), version 17.0 (SPSS
 Inc., Chicago, Illinois, USA), for conducting statistical
 analysis. Using descriptive statistics, the data were
 initially calculated as frequency (n) and percent (%). The quantitative
 variables were calculated as medians [interquartile range (IQR)].
 Statistical associations between the two groups were analyzed using
 independent student t-tests and Chi-square tests for quantitative and
 qualitative variables, respectively. A p-value of &lt;0.05 indicated a
 significant correlation between the variables at a 95% confidence
 interval. Statistical significance had to be determined
 for each bacterial category [fermentative-gram-negative bacteria (F-GNB),
 non-fermentative-gram-negative bacteria (NF-GNB), and gram-positive cocci
 (GPC)], considering the distinct testing protocols of quinolones utilized
 for AST, MIC, or MBIC. 
description: Microsoft Excel version 10.0 is required to open the data file of
 the manuscript.