Investigation of biofilm formation among clinical isolates ofKlebsiella pneumoniae in Bushehr province, Iran.

Background and Aim : Klebsiella pneumoniae is a Gram-negative bacte rium belonging to thefamily Enterobacteriaceae. K. pneumoniae causes a wide range of infections, includingpneumonia, urinary tract infections, bacteremia, and liver abscesses. Biofilm formation on thesedevices is important in the pathogenesis of these bacteria. It is a com plex process characterizedinto stages involving early attachment, microcolony formation, mature biofilm development andrelease of planktonic bacteria from the biofilm. This study aimed to investigate biofilm formationamong clinical isolates of K. pneumoniae in Bushehr province.Methods : : In this study, ۱۱۳ isolates of K. pneumoniae were obtained from various samplesreferred to seven hospitals in Bushehr province in ۲۰۱۸. Biofilm was assessed phenotypicallyusing microtitre plate assay. Briefly, ۲۰۰μl of overnight broth culture was transferred ontomicrotiter plates. Following ۲۴ hours incubation, ۲۵ μl of ۱% crystal violet was added to each welland incubated for ۱۵ minutes. Wells were washed three times with phosphate-buffered saline, andthen ethanol was added to dissolve the strain. OD values were taken at ۵۴۰ nm and interpretationswere made.Results : The results revealed that ۷۶.۹% of K. pneumoniae isolates were biofilm producers, with۴ (۳.۵%), ۳۳ (۲۹.۲%), and ۵۰ (۴۴.۲%) isolates as strong, moderate and weak biofilm producers,respectively.Conclusion : In the present study most of the K. pneumoniae isolates were biofilm producers.Biofilms have great significance for public health, because biofilm formation is one of theimportant features, particularly in chronic and recurrent nosocomial infections. In addition,biofilm-associated microorganisms exhibit dramatically decreased susceptibility to antimicrobialagents.

کلیدواژه ها:

klebsiella pneumoniae-virulance factor-biofilm