Time Kill Kinetics Study of Commonly Used Disinfectants against Biofilm forming Pseudomonas aeruginosa in Federal Medical Centre, Umuahia-Nigeria | Biomedgrid

Background: Noncritical surfaces in hospital environment can serve as reservoirs of pathogenic bacteria. Among these pathogens, biofilms forming Pseudomonas species are among the leading cause of nosocomial infections frequently involved in hospital environment. Pseudomonas aeruginosa, an opportunistic and biofilm forming pathogen, is the cause of a wide range of hospital acquired infections and can survive for several days on inanimate objects and surfaces in clinical settings. These survival properties most likely play a significant role in its infection dissemination and antibiotic resistance in the hospital environment where hospital cleaners frequently use disinfectants to clean without recourse to concentration or frequency of the cleaning. Aim of study: To determine the antibacterial activities of commonly used disinfectants-Izal (Phenolic Compound), Savlon (Chlorhexidine cetrimide), and bleach (Hypochlorite) involving Time kill kinetics studies in Federal Medical Centre, Umuahia on biofilm forming Pseudomonas aeruginosa. Study volunteers and methods: Four hundred and fifty positive (450) samples from noncritical surfaces of six selected wards of the hospital from 1314 samples. Bacterial analysis was performed by using conventional microbiological techniques, biochemical tests and the Microbact 24E assay. The time- kill kinetics antibacterial study of antiseptics was done according to standard guide for assessment of antimicrobial activity using time-kill kinetics procedure of Antimicrobial Susceptibility Testing Method and Microbial population at the initiation and completion was determined by spectrometric and plate count methods at interval of 2h for 24h. Result: Pseudomonas aeruginosa resisted the disinfectants after 4 h of initiation time/application. The 2mg/ml concentration of Izal achieved total lethality after 12h; Savlon, bacteriostatic effect was 8h (i.e. from 3.0x106 +5.774 to 3.02x106 +5.773b and 4.2x106 +5.774a to 3.21x106 +5.773e respectively) but 2mg/ml of Savlon showed total lethality (bactericidal effect) after 10h from initiation time (i.e. 4.5x106+5.774a to 2.2x105+5.773d). At concentration of 2mg/ml, Bleach showed outright lethality after 4h of initiation time (i.e. from 4.2x106 +5.774a to 3.90x105 +5.775) after which there remained no organism i.e. total eradication throughout the 24h of incubation period. Conclusion: 2mg/ml is the best concentration for Pseudomonas aeruginosa lethality to be achieved using Izal, Savlon and Bleach as disinfectants in FMC Umuahia. Bleach is the most efficacious disinfectant in use in Federal Medical Center Umuahia having demonstrated maximum lethality (maximum bactericidal effect) at a shorter time of 4h than Savlon, 8h and Izal, 12h though there was steady sustenance of bactericidal and bacteriostatic activity by Izal for a very long period compared to others.