In vitro biofilm formation by multidrug resistant clinical isolates of Pseudomonas aeruginosa

Sohana Al Sanjee,Mahamudul Hassan ,Ma Manchur

doi:10.3329/ajmbr.v4i1.36828

Sohana Al Sanjee, Mahamudul Hassan + Show 1 more

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https://doi.org/10.3329/ajmbr.v4i1.36828

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Abstract

In this study, 15 isolates of Pseudomonas aeruginosa were recovered in Cetrimide agar medium from aseptically collected swab samples. Antibiotic susceptibility test revealed highest resistance against Rifampicin (100%) followed by Penicillin (80%), Erythromycin (73.33%), Cephalosporin group (13.33-60%) and Aminoglycoside group (26.67%). The most effective group of antibiotic was Carbapenem with 6.67% resistance. Among 15 isolates, 3 were having highest Multiple Antibiotic Resistance (MAR) index were identified as Pseudomonas aeruginosa (P1, P2 and P3) by API®20NE microbial identification kit. Minimum inhibitory concentration (MIC) of the isolates P1, P2 and P3 was 3.05μg/mL, 0.76μg/mL and 3.05μg/mL for Meropenem whereas for Ceftriaxone it was 12.207μg/mL, 12.207μg/mL and 781.25μg/mL, respectively. Minimum bactericidal concentration (MBC) of Meropenem and Ceftriaxone was same for the isolates P1 and P2 i.e., 48.83μg/mL and 195.313μg/mL, respectively but in case of P3 it was 781.25μg/mL for both antibiotics. In case of 70% ethanol, the MIC and MBC was 1:4 dilutions (for isolate P3, MBC was 1:2 dilutions) whereas for Savlon®, MIC and MBC was 1% and 2% solution, respectively. All of the three isolates were biofilm former according to test tube assay and microtitre plate assay whereas modified congo red agar assay indicated only one isolate as biofilm former. The results suggest that post-operative wound infection may serve as a reservoir for multidrug resistant biofilm forming P. aeruginosa which may complicate the treatment regime unless proper treatment ensured based on antibiotic/antiseptic susceptibility test.Asian J. Med. Biol. Res. March 2018, 4(1): 105-116

Highlights

Post operative wound infections by multi-drug resistant (MDR) microorganisms are a global threat among the nosocomial infections leading to higher treatment expenditure, longer hospital stay, morbidity and mortality (Holzheimer et al, 2000; Pruitt et al, 1998; Naeem et al, 2006)
Isolation of P. aeruginosa and antibiogram profiling A total number of 15 P. aeruginosa isolates were recovered from post-operative wound infection on cetrimide agar medium following enrichment culture method and subjected to antibiotic susceptibility testing
The resistance and susceptibility pattern of the selected P. aeruginosa are shown in Table 1 and highest resistance was observed against Rifampicin (100%) followed by Ampicillin (80%), Erythromycin (73.33%) and Amoxiclave (53.33%)

Summary

Introduction

Post operative wound infections by multi-drug resistant (MDR) microorganisms are a global threat among the nosocomial infections leading to higher treatment expenditure, longer hospital stay, morbidity and mortality (Holzheimer et al, 2000; Pruitt et al, 1998; Naeem et al, 2006). The development of wound infection depends on the protective function of the skin which is a barrier of wound healing. Being most favorable site for biofilm formation, the wounds are considered as very high risk point for MDR microorganism infections. Post-operative wound infection is universal and the bacterial types present vary with geographic location, bacteria residing on the skin, clothing at the site of wound, time between wound and examination (Trilla, 1994).

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