Resistance in bacteria and indirect beta-lactamase detection in E. coli isolated from Culex pipiens detected by matrix-assisted laser desorption ionization time of flight mass spectrometry

ABSTRACT

The aim of this study was detections of antibiotic resistance and resistance mechanism in bacteria isolated from mosquitos (Culex pipiens) living near humans. Therefore, antibiotic resistance in bacteria isolated from Culex pipiens was investigated by disk diffusion test and MIC E-test in this study. MALDI-TOF mass spectrometry was used for detection of resistant mechanism. In this study, hydrolytic breakdown products after a few hours of incubation of the bacteria isolated from Culex pipiens were detected. Results show that enzymatic destruction of ampicillin by beta-lactamases is able to be detected by MALDI-TOF mass spectrometry from wild strains of potential pathogens. The MALDI-TOF mass spectrometry is useful method for routine detection of beta-lactamases resistant mechanism, but overnight incubation of pure culture is necessary. The results are important for proper and fast intervention to limit the spread of beta-lactamase-producing wild bacteria and provide information for appropriate initial therapy of the infections caused by these microbes.

KEYWORDS:

• Ampicillin
• antibiotic resistance
• Culex pipiens
• MALDI-TOF MS

Funding

The research leading to these results has received funding from the European Community under project no 26220220180 and the Building Research Centre “AgroBioTech,” by grant of VEGA 1/0611/14.