LasR and NdvB genes of Pseudomonas aeruginosa posed resistance against different antibiotic concentration and develop anti-biofilm properties against certain disinfectants level.

Abstract

Antibiotic resistance has become one of the most common problems that threaten the world and increases the mortality rate. Pseudomonas aeruginosa is reported to be one of commonest multi-drug resistant (MDR), which is responsible for 10 to 15% of nosocomial infection worldwide and high death rates ranging from 18 to 61%. We investigate the anti-biofilm activity of different disinfectants on MDR Pseudomonas aeruginosa. Two hundred two water environmental isolates were collected from different hospitals in Cairo, Egypt. Microbact™ Gram-negative system used for identification. That is showed 41.3% of isolates were Pseudomonas aeruginosa. Antibiotic susceptibility test revealed that 34.7% of the isolates were MDR. Biofilm production was determined by Congo red assay (CRA) and Microtitre plate (MTP) method. CRA showed 89% as biofilm producers. MTP method showed 87% were biofilm-forming. MIC of Carbapenems was determined by the broth macrodilution method. It showed that 50% of isolates were resistant. (MIC) Minimum Inhibitory Concentration of 7 disinfectants against 10-selected MDR strong biofilm Pseudomonas isolates was determined using the broth microdilution method. It showed that the most effective disinfectants with the lowest MICs were the Sodium hypochlorite 5% and Povidone-Iodine 10%. The Real-time PCR was done on lasR and ndvb genes for the selected isolate (E20) before and after exposure to both effective disinfectants. The sample E20 showed a significant down regulation for lasR and ndvb genes with both effective disinfectants. Our study showed that Povidone-iodine 10 % at appropriate concentrations at less than 30 minutes has significant anti-biofilm activity against MDR Pseudomonas aeruginosa.