The epidemiology and molecular characteristics of linezolid-resistant Staphylococcus capitis in Huashan Hospital, Shanghai

Abstract

Introduction. Linezolid-resistant (LZR) Staphylococcus capitis has recently emerged in our hospital, and its potential resistance mechanisms are still not clear. Aim. This study aimed to investigate the epidemiology, clinical and genetic characteristics, resistance mechanisms and biofilm formation capacity of LZR S. capiti s isolated from patients at Huashan Hospital, Shanghai, PR China between 2012 and 2018. Methodology. Strains were subjected to antimicrobial susceptibility testing (AST) with antibiotics using the broth microdilution method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. The presence of cfr, optrA and poxtA, as well as mutations in the 23S ribosomal (r)RNA and ribosomal proteins, was investigated using PCR and sequencing techniques. The genetic relationship between isolates was analysed using pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing (WGS). Biofilm biomasses were detected by using crystal violet staining. Results. Twenty-one LZR S. capitis strains displayed MICs of 32–512 μg ml−1. All LZR strains showed G2576T and C2104T mutations in the 23S rRNA V region. Besides G2576T and C2104T, no base mutations were detected in the V region. The cfr was detected in 12 strains, while optrA and poxtA were not amplified in 21 S . capitis strains. PFGE showed that the LZR S. capitis strains belonged to a single clone. The phylogenetic tree showed that 20 LZR S. capitis strains were highly similar to LNZR-1, isolated from Harbin (located in the north of China) in 2013, which showed resistance to linezolid. Conclusions. In this research, cfr-negative strains displayed linezolid MICs of 32 μg ml−1. In comparison, cfr-positive strains exhibited linezolid MICs of 128–512 μg ml−1, indicating that high levels of linezolid resistance appear to be related to the presence of cfr. The outbreak of LZR S. capitis in our hospital needs to be monitored closely.

Linezolid Resistance in Tanta University Hospitals: a Cross-sectional Study

“…In this study, the two linezolid-resistant isolates were both optrA-negative and poxtA-negative. These results were in partial agreement with Ding et al 25 who detected 21 linezolid-resistant staphylococcal isolated; 12 of them were positive for cfr, while all were optrA and poxtA negative.…”

Development of a novel core genome MLST scheme for tracing multidrug resistant Staphylococcus capitis

“…Using breseq, we mapped the genome reads to the 23S rRNA reference sequence and calculated the mutation proportion of each base. The mutation detection result indicated that the L clone is characterized by multiple copies of C2576G and C2104T mutations, in accordance with the findings of a previous study 17 . Based on this evidence, we inferred that the L clone might have been previously exposed to anti-ribosomal drugs such as linezolid or florfenicol, which are often used in the ICU.…”

“…To evaluate the applicability of the S. capitis cgMLST scheme for outbreak analysis, we reanalyzed the published genomic data of S. capitis isolates from an outbreak in Shanghai 17 and another independent outbreak in Sir Run Run Shaw Hospital in Hangzhou as well as two sporadic cases, one in Harbin and one in Hangzhou. All genomes included are listed in Supplementary Table 1 .…”

“…The need for a standardized typing method is urgent, considering the emergence of multidrug-resistant clones, especially clones resistant to linezolid 17 – 19 . Linezolid-resistant S. capitis (LRSC) poses a serious threat to clinical practice.…”

Increase in linezolid resistance in staphylococci in the private sector in Western Cape Province, South Africa

“…More recently, linezolid-resistant clones have been described in adult ICUs in Europe [4] and in China. [5] Further investigation is required to determine whether the linezolid-resistant S. capitis isolates in the Western Cape and other provinces are clonally related or not, and to elucidate the underlying mechanism(s) of resistance.…”