Detection of Biofilm Formation of Klebsiella Pneumoniae Isolated from Medical Devices at the University Hospital of Tlemcen, Algeria

Abstract

Background: Klebsiella pneumoniae is a major cause of community-acquired and nosocomial infections. This germ is responsible for acute and chronic infections, most of which are due to its ability to adhere to medical implants and form a biofilm. The objective of this work is to study the interaction between clinical isolates of K. pneumoniae and abiotic surfaces (medical devices) and some factors influencing biofilm formation. Methods: Over a period of 2 years, 115 strains of K. pneumoniae were isolated from medical devices CHU Tlemcen, most of which had a high level of resistance to cephalosporins 1 st , 2 nd , and 3 rd generation. Their capacity to form biofilm was assessed using 3 techniques: TCP, TP, and RCA. We determined in vitro the effects of three antimicrobial agents against planktonic and biofilm forms of K. pneumoniae. The presence of MrkD genes was detected by polymerase chain reaction (PCR). Results: According to the studied (TCP, TP, RCA) strains of K .pneumoniae isolated from urinary catheters have proved very good, forming the biofilm to those isolated from other medical devices. 24 of 115 isolated strains showed a clear difference in antibiotic susceptibility between planktonic populations and biofilm populations. They were 10-20 times higher. All strains presented a highly hydrophilic character and adhesion 2-10 times greater in PVC with respect to glass support. The MrkD gene (detected by PCR) responsible for biofilm formation was found in 22 strains of K. pneumoniae, which may explain their adhesion and therefor their pathogenicity. Conclusion:Our results show the great ability of K.pneumoniae strains to form a biofilm on medical devices, and the isolates were at least 10 times more resistant than their planktonic counterparts. In addition, we showed that the presence of type 3-encoding gene mrkD was associated with high adhesion indexes.

The influence of biofilm formation on carbapenem resistance in clinicalKlebsiella pneumoniaeinfections: phenotype vs genome-wide analysis

“…The MBEC assay also confirms the findings, as C3, C5, C6 and C8 strains showed an increase from MICs of ≤ 0.03 µg/ml (planktonic cells) to 2, 32, 128 and 4 µg/ml, respectively for biofilms. These susceptibility results of carbapenem on the fully-grown biofilm structure were consistent with the previous reports for gentamicin, cefotaxime and ciprofloxacin, amikacin and piperacillin in K. pneumoniae [18,19] . MBEC assays further revealed that the planktonic cells released from biofilm structure exhibited the same MICs as the biofilm cells, which might possibly be a mechanism for establishment of mobile resistant population in vivo causing clinical failure.…”

Characterization of Silver Carbonate Nanoparticles Biosynthesized Using Marine Actinobacteria and Exploring of Their Antimicrobial and Antibiofilm Activity

“…The strain used in this experience was isolated from urinary catheter and endotracheal tubes from the services of Intensive Care, Urology, and Neurology, at the University Hospital of Tlemcen. This strain was a high biofilm producer on inert surfaces as described previously by [78].…”

Biofilm Production by Uropathogens like Klebsiella spp and Pseudomonas spp and their Antibiotic Susceptibility

“…Gram nega ve isolates were further iden fied by different biochemical tests like oxidase, catalase, mo lity, indole and H S produc on, MR-VP, citrate u liza on, urea hydrolysis, 2 triple sugar iron u liza on tests. The iden ty of bacteria was, thus, established based as described in the book of 13 Cheesbrough.…”