J Glob Antimicrob Resist. 2021 Sep 1:S2213-7165(21)00196-X. doi: 10.1016/j.jgar.2021.08.004. Online ahead of print.
ABSTRACT
INTRODUCTION: The discharge of drug-resistant, biofilm-forming pathogens from hospital effluent water into municipal wastewater treatment plants poses a public health concern. The present study examined the relationship between antibiotic resistance levels and biofilm formation of Acinetobacter baumannii strains isolated from hospital effluents.
METHODS: Antibiotic susceptibility of 71 A. baumannii isolates was evaluated using the Kirby Bauer disc diffusion method. The minimum inhibitory concentration was performed by the agar dilution method, while the minimum biofilm eradication concentration was performed by the broth dilution method. Genotyping was performed with plasmid DNA. Biofilm formation was evaluated by the microtitre plate method and quantified using crystal violet. P-values < 0.05 were regarded as statistically significant in all the tests conducted.
RESULTS: The extended spectrum resistant (XDR) strains made up 58% of the isolates while MDR and pan drug resistance (PDR) were observed in 50% of the isolates from the final effluent. The MBEC of ciprofloxacin increased by 255-fold while that of ceftazidime was as high as 63-1310-fold compared to their respective MICs. Isolates were classified into four plasmid pattern groups and no significance difference exists between biofilm formation and plasmid type (P = 0.0921). The degree of biofilm formation was independent of the level of antibiotic resistance, although MDRs, XDRs and PDRs produced significant biofilm biomass (P = 0.2580).
CONCLUSION: The results suggest that hospital effluent is a potential risk for multidrug-resistant biofilm-forming A. baumannii strains. Appropriate treatment and disposal for effluents are essential to prevent presence of drug resistance pathogens in waste water.
PMID:34481121 | DOI:10.1016/j.jgar.2021.08.004
