Publication details

No Correlation between Biofilm-Forming Capacity and Antibiotic Resistance in Environmental Staphylococcus spp.: In Vitro Results

Authors

DONADU Matthew Gavino FERRARI Marco MAZZARELLO Vittorio ZANETTI Stefania KUSHKEVYCH Ivan RITTMANN Simon K.-M. R. STÁJER Anette BARÁTH Zoltán SZABÓ Dóra URBÁN Edit GAJDÁCS Márió

Year of publication 2022
Type Article in Periodical
Magazine / Source Pathogens
MU Faculty or unit

Faculty of Science

Citation
Web https://www.mdpi.com/2076-0817/11/4/471
Doi http://dx.doi.org/10.3390/pathogens11040471
Keywords Congo red agar; crystal violet; microtiter plate assay; biofilm formation; Staphylococcus aureus; non-aureus staphylococci; methicillin resistance; multidrug resistance; MDR; phenotypic assay
Description The production of biofilms is a critical factor in facilitating the survival of Staphylococcus spp. in vivo and in protecting against various environmental noxa. The possible relationship between the antibiotic-resistant phenotype and biofilm-forming capacity has raised considerable interest. The purpose of the study was to assess the interdependence between biofilm-forming capacity and the antibiotic-resistant phenotype in 299 Staphylococcus spp. (S. aureus n = 143, non-aureus staphylococci [NAS] n = 156) of environmental origin. Antimicrobial susceptibility testing and detection of methicillin resistance (MR) was performed. The capacity of isolates to produce biofilms was assessed using Congo red agar (CRA) plates and a crystal violet microtiter-plate-based (CV-MTP) method. MR was identified in 46.9% of S. aureus and 53.8% of NAS isolates (p > 0.05), with resistance to most commonly used drugs being significantly higher in MR isolates compared to methicillin-susceptible isolates. Resistance rates were highest for clindamycin (57.9%), erythromycin (52.2%) and trimethoprim-sulfamethoxazole (51.1%), while susceptibility was retained for most last-resort drugs. Based on the CRA plates, biofilm was produced by 30.8% of S. aureus and 44.9% of NAS (p = 0.014), while based on the CV-MTP method, 51.7% of S. aureus and 62.8% of NAS were identified as strong biofilm producers, respectively (mean OD570 values: S. aureus: 0.779±0.471 vs. NAS: 1.053±0.551; p < 0.001). No significant differences in biofilm formation were observed based on MR (susceptible: 0.824 ± 0.325 vs. resistant: 0.896 ± 0.367; p = 0.101). However, pronounced differences in biofilm formation were identified based on rifampicin susceptibility (S: 0.784 ± 0.281 vs. R: 1.239 ± 0.286; p = 0.011). The mechanistic understanding of the mechanisms Staphylococcus spp. use to withstand harsh environmental and in vivo conditions is crucial to appropriately address the therapy and eradication of these pathogens.

You are running an old browser version. We recommend updating your browser to its latest version.

More info