Analysis of Antibiotic Resistance and Virulence Traits (Genetic and Phenotypic) in Klebsiella pneumoniae Clinical Isolates from Pakistan: Identification of Significant Levels of Carbapenem and Colistin Resistance

Abstract

Background:The emergence of carbapenem-resistant and hypervirulent hypermucoviscous Klebsiella pneumoniae strains poses a significant public health challenge. We determined the MDR profiles, antibiotic resistance factors, virulence gene complement, and hypermucoviscous features of 200 clinical K. pneumoniae isolates from two major tertiary care hospitals in Islamabad and Rawalpindi, Pakistan. Methods: Susceptibility profiling and phenotypic analysis were performed according to the CLSI guidelines. Genetic determinants of antibiotic resistance and virulence were detected by PCR. Biofilm formation analysis was performed by microtiter plate assay. Results: The isolates displayed a high degree of antibiotic resistance: 36% MDR-CRKP; 38% carbapenem resistance; 55% gentamicin resistance; 53% ciprofloxacin resistance; and 59% aztreonam resistance. In particular, the level of resistance against fosfomycin (22%) and colistin (15%) is consistent with previous reports of increased resistance levels. Combined resistance to carbapenem and colistin was 7%. Genetic factors associated with colistin resistance (mcr-1 and mcr-2 genes) were detected in 12 and 9% of the isolates, respectively. Significant differences in resistance to gentamicin and levofloxacin were observed between the 200 isolates. Many of the isolates harbored genes specifying extended-spectrum and/or carbapenem-resistant β-lactamases: bla CTX-M-15 (46%), bla NDM-1 (39%), and bla OXA-48 (24%). The prevalence of the hypermucoviscous phenotype was 22% and 13% of the MDR isolates carried the rmpA gene (regulator for mucoid phenotype). Key virulence factor genes detected include those encoding: porins (ompK35 and ompK36; at 56 and 55% prevalence, respectively); adhesins (fimH, mrkD, and ycfM; at 19, 18, and 22% prevalence, respectively); and the polysaccharide regulator, bss, at 16% prevalence. Conclusion: This report highlights carbapenem-resistant K. pneumoniae (CRKP) prevalence, emerging resistance to fosfomycin, and the presence of mcr-1 and mcr-2 in colistin-resistant isolates. Further, the detection of rmpA signifies the prevalence of the hypermucoviscous trait in CRKP clinical isolates from Pakistan.

Occurrence of Hypervirulent Klebsiella pneumoniae in Clinical Settings and Lytic Potential of Bacteriophages Against the Isolates

“…Additionally, nearly 40% resistance was determined against carbapenems, namely meropenem and imipenem. The minimum resistance was determined against colistin which was about 15%; however, 22% colistin resistance was determined in isolates collected in the present study (45). In comparison to the previous study conducted in Pakistan during 2010, this study reported 50% resistance to carbapenems which means a 50% MDR prevalence ratio, higher than previously noted (46).…”

Effective Photodynamic Therapy with Ir(III) for Virulent Clinical Isolates of Extended-Spectrum Beta-Lactamase Klebsiella pneumoniae

“…In the K. pneumoniae population, the median and IQR (25-75%) of the MIC were determined and expressed in mg/L in a log 2 box plot. As shown in Figure 1B, the bacterial population was mainly susceptible to Amk with a median (IQR) of 8 (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). Similar to Amk, the population was mainly susceptible to carbapenem, Imp, and Mer with a median of 1 (0.5-1) and 1 (0.5-2), respectively.…”

“…The high MDR shown by strains of K. pneumoniae does not fully explain its notable success as one of the most important agents of HAIs, suggesting the participation of other factors [ 9 ]. An increasing number of authors suggest that increased bacterial survival during infections is related to virulence factors [ 1 , 3 , 9 , 10 , 11 , 12 , 13 , 14 ].…”

Effective Photodynamic Therapy with Ir(III) for Virulent Clinical Isolates of Extended-Spectrum Beta-lactamase <em>Klebsiella pneumoniae</em>

“…In the K. pneumoniae population, the median and IQR (25-75%) of the MIC were determined and expressed in mg/L in a log2 box plot. As shown in Figure 1B, the bacterial population was mainly susceptible to Amk with a median (IQR) of 8 (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). Similar to Amk, the population was mainly susceptible to carbapenem, Imp, and Mer with a median of 1 (0.5 -1) and 1 (0.5 -2), respectively.…”

“…The high MDR shown by strains of K. pneumoniae does not fully explain its notable success as one of the most important agents of HAIs, suggesting the participation of other factors [9]. An increasing number of authors suggest that increased bacterial survival during infections is related to virulence factors [1,3,[9][10][11][12][13][14].…”