The Role of EDTA in Biofilm Eradication of Klebsiella pneumoniae Isolated from Wound Infections


Abstract: Klebsiella pneumoniae is one of the main pathogens which cause wound infections. Biofilm-producers of these bacteria have a high level of resistance to antibiotics and this leads to complications for the treatment of several infections. The study tested the effect of ethylenediaminetetraacetic acid (EDTA) on the biofilm formation by multidrug-resistant (MDR), strong biofilm producer K. pneumoniae isolates from Baghdad hospitals, Iraq. The Minimum Inhibitory Concentrations (MICs) by Microtiter Plate Assay with resazurin dye and the ability for in vitro biofilm formation by Microtiter plate assay using crystal violet were detected in MDR K. pneumoniae isolates in the presence of eight concentrations of EDTA (4 to 512 µg/ml). Out of 45 K. pneumoniae isolates, 35 (77.7 %) were Multi-Drug Resistant (MDR) and 25 (55.5%) were strong biofilm producers. It was found that all isolates of K. pneumoniae (100 %) were resistant to Ampicillin and Cephalexin, while these isolates exhibited a low-level resistance against Tigecycline, Meropenem and Imipenem. The results of Minimum Inhibitory Concentrations revealed that the effect of EDTA on the growth of K. pneumoniae isolates was recorded at concentrations (32-512 μg/ml). The highest antibiofilm activity by EDTA was demonstrated at the subinhibitory concentration (256 μg/ml) with biofilm eradication percent (94.28%), while at very low concentrations (8 μg/ml), it was found an obvious eradication effect on biofilm (82.11 %). The study suggests that EDTA plays an important role in the early stage of biofilm formation with a clear effect on the growth of MDR K. pneumoniae.