High-Level Aminoglycoside Resistance in Human Clinical Klebsiella pneumoniae Complex Isolates and Characteristics of armA-Carrying IncHI5 Plasmids

Abstract

Aminoglycosides are important options for treating life-threatening infections. However, high levels of aminoglycoside resistance (HLAR) among Klebsiella pneumoniae isolates have been observed to be increasing frequently. In this study, a total of 292 isolates of the K. pneumoniae complex from a teaching hospital in China were analyzed. Among these isolates, the percentage of HLAR strains was 13.7% (40/292), and 15 aminoglycoside resistance genes were identified among the HLAR strains, with rmtB being the most dominant resistance gene (70%, 28/40). We also described an armA-carrying Klebsiella variicola strain KP2757 that exhibited a high-level resistance to all aminoglycosides tested. Whole-genome sequencing of KP2757 demonstrated that the strain contained one chromosome and three plasmids, with all the aminoglycoside resistance genes (including two copies of armA and six AME genes) being located on a conjugative plasmid, p2757-346, belonging to type IncHI5. Comparative genomic analysis of eight IncHI5 plasmids showed that six of them carried two copies of the intact armA gene in the complete or truncated Tn1548 transposon. To the best of our knowledge, for the first time, we observed that two copies of armA together with six AME genes coexisted on the same plasmid in a strain of K. variicola with HLAR. Comparative genomic analysis of eight armA-carrying IncHI5 plasmids isolated from humans and sediment was performed, suggesting the potential for dissemination of these plasmids among bacteria from different sources. These results demonstrated the necessity of monitoring the prevalence of IncHI5 plasmids to restrict their worldwide dissemination.

Synergistic Antibiofilm Efficacy of Thymol and Piperine in Combination with Three Aminoglycoside Antibiotics against Klebsiella pneumoniae Biofilms

“…However, the antimicrobial activity of piperine is higher against Grampositive bacteria as compared to that of Gram-negative bacteria [20]. Despite the high levels of aminoglycoside resistance among Klebsiella pneumoniae isolates observed in previous studies [21], all of K. pneumoniae planktonic cells isolates were susceptible to streptomycin, amikacin, and kanamycin in this study.…”

Whole Genome Sequence Analysis of Multidrug Resistant Escherichia coli and Klebsiella pneumoniae Strains in Kuwait

“…The mechanism of resistance to aminoglycosides mainly occurs due to the presence of aminoglycoside-modifying enzymes (AMEs) and their different ability to modify aminoglycosides. These enzymes include acetyltransferases (AACs), nucleotidyltransferases (ANTs), and phosphotransferases (APHs) were described in Enterobacterales [ 33 ]. In our findings, MICs for gentamicin and/or amikacin showed high-level resistance in 3 isolates expressing various aminoglycosides gene as E4-485, aac(6′)-Ib3 gene; E2-466, aad and aac(3)-IIa genes and K3-441, aac(6′)-Ib and aadA1 genes.…”

Co-Occurrence of Rare ArmA-, RmtB-, and KPC-2–Encoding Multidrug-Resistant Plasmids and Hypervirulence iuc Operon in ST11-KL47 Klebsiella pneumoniae

“…Although the 16S RMTase-encoding genes, especially rmtB and armA , were widely present in Enterobacteriaceae , the coexistence of two or more such genes was unusual. Previous studies found that the two copies of armA combined with six AME genes in one isolate could mediate an extremely high aminoglycosides resistance level (>1,024 mg/L) ( 13 ). These results indicated that the co-occurrence of multiple aminoglycosides resistance genes may result in a higher resistance phenotype.…”