Molecular Characterization of a Multidrug-Resistant Klebsiella pneumoniae Strain R46 Isolated from a Rabbit

Abstract

To investigate the mechanisms of multiple resistance and the horizontal transfer of resistance genes in animal pathogens, we characterized the molecular structures of the resistance gene-related sequences in a multidrug-resistant Klebsiella pneumoniae strain R46 isolated from a rabbit. Molecular cloning was performed to clone the resistance genes, and minimum inhibitory concentrations (MICs) were measured to determine the resistance characteristics of the cloned genes and related strains. A conjugation experiment was conducted to assess the transferability of the resistance plasmids. Sequencing and comparative genomic methods were used to analyze the structures of the resistance gene-related sequences. The K. pneumoniae R46 genome consisted of a chromosome and three resistance plasmids named pR46-27, pR46-42, and pR46-270, respectively. The whole genome encoded 34 antibiotic resistance genes including a newly identified chromosome-encoded florfenicol resistance gene named mdfA2. pR46-270, besides encoding 26 antibiotic resistance genes, carried four clusters of heavy metal resistance genes and several virulence-related genes or gene clusters. The plasmid-encoded resistance genes were mostly associated with mobile genetic elements. The plasmid with the most similarity to the floR gene-harboring plasmid pR46-27 was pCTXM-2271, a plasmid from Escherichia coli. The results of this work demonstrated that the plasmids with multidrug resistance genes were present in animal-derived bacteria and more florfenicol resistance genes such as mdfA2 could be present in bacterial populations. The resistance genes encoded on the plasmids may spread between the bacteria of different species or genera and cause the resistance dissemination.

The Two-Component System CopRS Maintains Subfemtomolar Levels of Free Copper in the Periplasm of Pseudomonas aeruginosa Using a Phosphatase-Based Mechanism

“…Although absent in Salmonella (6), many Enterobacteriaceae (e.g., Escherichia coli, Klebsiella pneumoniae, etc.) modulate periplasmic Cu 1 stress responses via the chromosomally encoded TCS CusRS and the plasmid-borne PcoRS (24)(25)(26)(27)(28)(29)(30). Instead, CopRS monitors extracytoplasmic Cu 1 accumulation in Corynebacterium glutamicum and Synechocystis (31)(32)(33).…”

Characterization and Plasmid Profile of Resistant Klebsiella pneumoniae Isolates in Patients with Urinary Tract Infection in Nasarawa State, Nigeria

“…The SHV and TEM both contributed to conferring resistance on the isolates which is transferable. The issues of Klebsiella pneumoniae resistance genes between human and animals have been raised by Wu et al (2019). The authors investigated the mechanism of multiple resistance and dissemination of resistance genes by the pathogen, and recommended proactive surveillance of florfenicol-resistant strains in animals.…”

Detection and prevalence of multidrug-resistant Klebsiella pneumoniae strains isolated from poultry farms in Blitar, Indonesia

“…Notably, the prevalence of antibiotic resistance is increasing among Enterobacteriaceae, including K. pneumoniae strains isolated from animals (Davis and Price 2016). Due to the extensive use of antibiotics in humans, veterinary medicine, and agricultural practice during the last few decades, the emergence of K. pneumoniae strains that harbor various resistance genes has increased considerably K. pneumoniae has acquired increasingly high levels of antimicrobial drug resistance (Wu et al 2019).…”