Comparison of biofilm formation and efflux pumps in ESBL and carbapenemase producing Klebsiella pneumoniae

Abstract

Introduction: Klebsiella pneumoniae is an opportunistic pathogen that causes a range of diseases. The appearance of extended-spectrum β-lactamase -and carbapenemase-producing strains, in addition to the biofilm-forming phenotype, is a major problem in the clinical environment.
 Methodology: A total of 33 clinical K. pneumoniae isolates were used in this study. Antimicrobial susceptibilities were assessed by a disc diffusion assay. Biofilm formation was determined by a microtiter plate assay, staining with 1% crystal violet and measuring absorbance after destaining. Moreover, expression of acrA, kdeA, ketM, kpnEF, and kexD efflux associated genes was measured by qRT-PCR.
 Results: Isolates displayed high resistance to β-lactams such as cefazolin, cefuroxime, ceftriaxone, cefepime, piperacillin-tazobactam, imipenem, and meropenem and decreased resistance to gentamicin, amikacin, ciprofloxacin, and levofloxacin. ESBL-producing isolates formed more biofilm than carbapenemase-producing isolates. The mRNA expression levels in KPC isolates for acrA (2-fold), kdeA (2.7-fold), ketM (2.2-fold), and kpnEF (3.4-fold) were significantly increased compared to ESBL-producing isolates. There was no significant difference in kexD expression level.
 Conclusions: Under the conditions used here ESBL-producing isolates formed more biofilm than KPC postive isolates; this was associated with virulence determinants which were also transferred by plasmids together with ESBLs enzymes. Moreover, the upregulation of acrA, kdeA, ketM, and kpnEF efflux pumps was seen in carbapenemase-producing isolates demonstrating that high expression of efflux pumps alone could not confer resistance but may act as a physiological determinant such as bacterial pathogenicity and virulence, and cell-to-cell communication for bacteria.

Characterization of β-lactam resistance in K. pneumoniae associated with ready-to-eat processed meat in Egypt

“…showed that 51% of collected K . pneumoniae were ESBL-producers, 49% of them were carbapenemase-producers [ 8 ]. These results may be attributed to the excessive use of these antibiotics.…”

“…Japoni-Nejad et al showed that 12 isolates were carbapenemases-producers and 8 of them were AmpC-producers [34]. Besides, Yazgan et al showed that 51% of collected K. pneumoniae were ESBL-producers, 49% of them were carbapenemase-producers [8]. These results may be attributed to the excessive use of these antibiotics.…”

“…Antibiotics are ejected from the cell, thus decreasing antibiotic concentrations inside the cell. Efflux pumps are classified into five major families: the resistance-nodulation-division (RND) family, the major facilitator superfamily (MFS), the ATP (adenosine triphosphate)-binding cassette (ABC) superfamily, the small multidrug resistance (SMR) family, and the multidrug and toxic compound extrusion (MATE) family [8]. ERICs are repetitive intergenic sequences of the Enterobacteriaceae family comprising of 126 base pairs.…”

Emergence of tigecycline-resistant Klebsiella pneumoniae ST11 clone in patients without exposure to tigecycline

“…However, in recent years, resistance to tigecycline has emerged in multidrug-resistant (MDR) strains of various pathogens, in particular, Acinetobacter baumannii, Klebsiella pneumoniae and Enterobacteriaceae. In recent decades, various strains of tigecycline-resistant pathogenic bacteria have been reported from the USA, UK, France, Saudi Arabia, Greece, Spain, Germany and Taiwan [3,4]. Most of them changed from tigecyclinesensitive to tigecycline-resistant during treatment, with the highest reported minimum inhibitory concentration (MIC) of tigecycline being 24 µg/mL.…”

Analysis of antibiotic resistance and virulence patterns inKlebsiella pneumoniaeisolated from human urinary tract infections in India

“…Biofilm formation is another crucial virulence mechanism of this organism responsible for its nosocomial importance. Biofilm is a group of microorganisms that are attached to living and non-living surface and plays a protective role against antibiotics and macrophages (Yazgan et al 2018). Ever since the first report of biofilm formation phenomenon in K. pneumoniae emerged in 1988, many research works have suggested a strong association between biofilm formation, virulence and multidrug resistance (MDR) mechanisms (Nirwati et al 2019).…”