Investigating the Resistance of Klebsiella Pneumoniae Clinical Isolates Producing Carbapenemase and ESBL Enzymes to Colistin and Fosfomycin Antibiotics

A Klebsiella pneumoniae bacterium, which is the most important species of the Klebsiella genus, mainly causes hospital infections. Moreover, it has a high resistance to most of the available antibiotics, which has caused concern among doctors all over the world. Therefore, the amount of antibiotic resistance and the effect of these antibiotics on Klebsiella pneumoniae isolates producing carbapenemase and ESBL enzymes with multi-drug resistance are investigated in this research.

Methods and Materials:

 Different strains of Klebsiella pneumoniae bacteria were identified and isolated from different clinical samples during 4 months (September 1400 to late December 1400) from hospitals and laboratories in Tehran. After determining the identity using biochemical tests, the isolates were investigated and re-identified by molecular method. Antibiotic resistance was determined by disk diffusion method. Then, the production of ESBL and carbapenemase were performed using the respective discs and checking the diameter of the inhibition zone. The ELISA test was repeated three times in order to investigate the creation of biofilm in strains with multiple resistances. Molecular testing was used again to identify fosA3, mcr1 and mcr2 genes. At the end, the results were evaluated using the software.

Out of 127 samples, 112 (88٪) isolates were of Klebsiella genus, and 80 (63٪) samples of Klebsiella pneumoniae were isolated using molecular tests.61 (76٪) samples had multidrug resistance. The lowest resistance was reported to amikacin (AN), gentamicin (GM) and meropenem (MEN) with 0, 1 and 3 resistant samples, respectively. Furthermore, the highest resistance to ampicillin (AM), piperacillin (PIP) and chloramphenicol (CL) were reported with 79, 66 and 67 resistant samples, respectively. By examining the diameter of the inhibition zone, among 80 Klebsiella pneumoniae strains, 51 (63.75٪) were beta-lactamaseproducing isolates and 29 (36.25٪) were carbapenemase-producing isolates.Out of 61 (76٪) samples with multiple resistance, 56 samples formed biofilm.The results of molecular tests for ESBL genes showed only the expression of mcr2 and the amplification of carbapenemase genes was only expressed for mcr2 and fosA3.

The frequency of Klebsiella pneumoniae isolates that produce biofilm, ESBL and carbapenemase with the expression of mcr-2 and fosA genes are increasing in hospitals.