Dataset Information

High prevalence of bla _CTX-M-15 and nosocomial transmission of hypervirulent epidemic clones of Klebsiella pneumoniae at a tertiary hospital in Ethiopia.

ABSTRACT:

Background

Genomic epidemiology of antibiotic resistance is not sufficiently studied in low-income countries.

Objectives

To determine prevalence of ESBL production, and resistome and virulome profiles, of Klebsiella pneumoniae isolated at Jimma Medical Center, Ethiopia.

Methods

Strains isolated from patients with suspected infections between June and November 2016 were characterized by MALDI-TOF for species identification and disc diffusion for antimicrobial susceptibility testing. All K. pneumoniae isolates were characterized by double disc diffusion for ESBL production and all ESBL-producing strains (ESBL-KP) were subjected to WGS on the Illumina (HiSeq 2500) platform. DNA was extracted by automated systems (MagNA Pure 96). Genome assembly was performed using SPAdes (v. 3.9) and draft genomes were used for analysing molecular features of the strains. Maximum likelihood trees were generated using FastTree/2.1.8 based on SNPs in shared genomic regions to identify transmission clusters.

Results

Of the 146 K. pneumoniae strains isolated, 76% were ESBL-KP; 93% of the ESBL-KP strains showed resistance to multiple antimicrobial classes. bla _CTX-M-15 (84.4%) was the most prevalent ESBL gene. Resistance genes for aminoglycosides and/or fluoroquinolones [aac(6')-Ib-cr (65.1%)], phenicols [catB3 (28.4%)], sulphonamides [sul1 (61.2%) and sul2 (60.5%)], trimethoprim [dfrA27 (32.1%)], macrolides [mph(A) (12.8%)] and rifampicin [arr2/arr3 (39.4%)] were prevalent. Plasmids of the IncF and IncR families were prevalent among ST218, ST147, ST15 and ST39. KL64 and KL57 capsular types and O1 and O2 LPSs were prevalent. A high-risk clone, ST218-KL57 encoding rmpA1/rmpA2 and iutA, was detected. Phylogenetic analysis showed a cluster of clonally related strains from different units of the hospital.

Conclusions

Prevalence of ESBL-KP was high and bla _CTX-M-15 was the predominant ESBL gene. ESBL genes had spread through both clonal and polyclonal expansion of high-risk and hypervirulent clones. Nosocomial transmission of MDR strains between different units of the hospital was observed.

SUBMITTER: Sewunet T

PROVIDER: S-EPMC8210115 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:ObjectivesAlthough hypervirulent Klebsiella pneumoniae (hvKp) is an increasing public health problem, there remains limited epidemiological information regarding hvKp infections in children. Here, we conducted a clinical, molecular and phenotypic surveillance of hvKp strains in a pediatric population.MethodsNon-repetitive K. pneumoniae (Kp) strains consecutively collected during 2019-2020 were screened for hypervirulence genes (prmpA, prmpA2, iucA, iroB, and peg344) using PCR. Positive strains were further characterized by four phenotypic assays (string test, serum killing assay, siderophore production, Galleria mellonella lethality assay), followed by murine sepsis model to determine virulence in vitro and in vivo. Also, capsular types, sequence types, plasmid replicon types, antimicrobial resistance determinants and susceptibility were analyzed.ResultsA total of 352 isolates were collected, wherein 83 (23.6%) were hypervirulence genes-positive Kp (hgKp). A significant increase in KPC-2-producing KL47-ST11 among hgKp strains was observed, from 5.3% (1/19) in 2019 to 67.6% (25/37) in 2020 (P<.0001), suggesting the potential dissemination of the hybrid virulence and carbapenem-resistance encoding plasmid among children. Further, hgKp isolates were classified into hvKp (n = 27) and hgKp-low virulence (hgKp-Lv) (n = 56) based on virulence phenotypic assays. In hvKp, diverse genetic clones were observed and K1-ST23 or K2-ST25 strains with sensitivity to multiple antibiotics were prevalent (25.9%, 7/27). Compared with hgKp-Lv, hvKp infection had a higher propensity to involve severe pneumonia (22.2% vs. 12.5%) in elder children and significant higher mortality in mice (P = 0.0086). Additionally, either hvKp or hgKp-Lv infections were mostly healthcare-associated and hospital-acquired (74.1% vs. 91.9%).ConclusionsThese data suggest that K1-ST23 and K2-ST25 are high-risk clones of hvKp, and the genetic convergence of virulence and carbapenem-resistance is increasing among children. Control measures are needed to prevent the dissemination in clinical settings.

Project description:BackgroundCapsular serotype K2 Klebsiella pneumoniae of sequence type (ST) 65 has been recognized as a hypervirulent clone. Simultaneous presence of different bla CTX-M genes has never been reported in this clone. In the present study, the genetic characteristics and virulence phenotype of a CTX-M-3 and CTX-M-14 coproducing ST65 K. pneumoniae human isolate, KP_06, that caused an intracranial infection, are evaluated.MethodsThe potential virulence of KP_06 was assayed by in vitro and in vivo methods. The molecular biology and whole-genome sequencing technology were used to analyze the genomic features associated with the virulence of this strain.ResultsThe KP_06 exhibited typical features of hypervirulent K. pneumoniae (hvKP), showing hypermucoviscosity phenotype and belonging to K2 and ST65. Apart from virulence genes linked to hvKP, including rmpA, rmpA2, and clb cluster and genes encoding siderophores, it was found to harbor a ~170 kb pLVPK-like virulence plasmid. In contrast to most hvKP, KP_06 was resistant to cephalosporins and the coexistence of bla CTX-M-3 and bla CTX-M-14 was detected. Further experiments demonstrated that this strain was classified as a nonbiofilm producer and serum sensitivity (grade 1) and killed only 30% of Galleria mellonella inoculated with 1×106 colony-forming unit of the specimen within 48 hours, suggesting relatively low virulence. Comparative genomic analysis of KP_06 with five K2 hypermucoviscous K. pneumoniae (HMKP) revealed seven unique orthologies with varied function in this strain. Intriguingly, the virulence genes identified in KP-06 were unexpectedly more diverse than those observed in five other K2 HMKP strains.ConclusionOur data support the notion that neither virulence-associated genes (clusters) nor the pLVPK-like virulence plasmid is sufficient for the hypervirulence of K. pneumoniae. Future studies aiming to explore the virulence of K. pneumoniae should take genome-based profile together with experimental work. The detailed mechanism involving in the impaired virulence of KP_06 remains to be further explored.

Dataset Information

High prevalence of bla _CTX-M-15 and nosocomial transmission of hypervirulent epidemic clones of Klebsiella pneumoniae at a tertiary hospital in Ethiopia.

Background

Objectives

Methods

Results

Conclusions

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Dataset Information

High prevalence of bla CTX-M-15 and nosocomial transmission of hypervirulent epidemic clones of Klebsiella pneumoniae at a tertiary hospital in Ethiopia.

Background

Objectives

Methods

Results

Conclusions

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

High prevalence of bla _CTX-M-15 and nosocomial transmission of hypervirulent epidemic clones of Klebsiella pneumoniae at a tertiary hospital in Ethiopia.