Moderate Production of Biofilm by Clinical isolates of E. coli and Pseudomonas spp in Burkina Faso

Author(s): Albert Oueremi, Abdoul Karim Ouattara, Amana Mètuor Dabiré, Rahimatou Yasmine Wendkuni Tiemtoré, Serge Sougué, Jacques Simpor

Background: Infections caused by biofilm-producing microbes are associated with common human illnesses that are difficult to treat due to antibiotic resistance, especially when the bacteria also produce beta-lactamases. The aim of the present study was to evaluate the ability of clinical strains of Escherichia coli and Pseudomonas spp that produce beta-lactamases to produce biofilm.

Methods: The study involved two clinical strains of Escherichia coli and Pseudomonas spp that produce beta-lactamases and were isolated from pus samples at the Centre Hospitalier Universitaire Pédiatrique Charles de Gaulle of Ouagadougou, Burkina Faso. Biofilm production was assessed using the microtiter plate-based crystal violet assay, with the PA01 WT strain used as a positive control for biofilm production. Biofilm was quantified by measuring optical densities with a spectrophotometer.

Results: The E. coli strain was resistant to cefotaxime, ceftriaxone, and ceftazidime, while in addition to these antibiotics, Pseudomonas spp was resistant to imipenem. Both strains were beta-lactamase producers confirmed by the detection of blaNDM and blaIMP genes in E. coli and blaNDM, blaCTX and blaSHV in Pseudomonas spp. Optical density measurements after crystal violet staining showed that both strains were moderate biofilm producers.

Conclusions: This study highlights that clinical isolates of E. coli and Pseudomonas spp, which are responsible for human infections and produce beta-lactamases, are also moderate biofilm producers. This is a real public health concern requiring surveillance efforts and investigations to prevent and effectively combat this form of resistance.