Valzano Felice, Beccia Elisa, La Bella Gianfranco, Marangi Marianna, Arena Fabio
Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.
Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy; Azienda Sanitaria Locale della Provincia di Foggia, Foggia, Italy.
J Glob Antimicrob Resist. 2025 Jun;43:242-247. doi: 10.1016/j.jgar.2025.04.028. Epub 2025 May 5.
To describe the phenotypic and genetic features of vancomycin-resistant Enterococci (VRE) isolates exhibiting resistance to tetracycline (TET), tigecycline (TGC), and eravacycline (ERV).
Between December 2023 and September 2024, 32 VRE were collected from clinical samples at the Policlinico Foggia, Italy. Bacterial identification was carried out by matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis. Antimicrobial susceptibility testing for vancomycin, TET, TGC, and ERV was performed by the reference broth microdilution method. Whole-genome sequencing was carried out to explore the content of tetracycline resistance determinants, and the phylogenetic relationship between isolates (in silico multilocus sequence typing [MLST] and single-nucleotide polymorphisms [SNPs] analysis).
Among the studied isolates, 30 and 2 were vancomycin-resistant Enterococcus faecium (VREfm) and vancomycin-resistant Enterococcus faecalis (VREfs), respectively. Overall, eight isolates (six VREfm and two VREfs) were resistant to TET (8/32, 25%), with four (all VREfm) being resistant to TGC and ERV (4/32, 12.5%), also. The two TET-resistant VREfs strains belonged to sequence type (ST)6 and carried the tet(M) gene only. All the TET-resistant VREfm were ST80 and carried the tet(L) and tet(M) genes. Among these, the four TGC-resistant and ERV-resistant strains showed an uncommon Y58D substitution in the ribosomal S10 protein (rpsJ gene). SNPs analysis revealed that Y58D-carrying strains formed a separate cluster, within ST80 VREfm.
In this study, we correlated the presence of the Y58D mutation in the rpsJ gene with resistance to TGC and ERV in a cluster of VREfm ST80 clinical strains. The Y58D mutation was invariably found in co-presence with the tet(L) and tet(M) genes.
描述对四环素（TET）、替加环素（TGC）和依拉环素（ERV）耐药的耐万古霉素肠球菌（VRE）分离株的表型和遗传特征。
2023年12月至2024年9月期间，从意大利福贾综合医院的临床样本中收集了32株VRE。通过基质辅助激光解吸电离飞行时间质谱分析进行细菌鉴定。采用参考肉汤微量稀释法对万古霉素、TET、TGC和ERV进行药敏试验。进行全基因组测序以探索四环素耐药决定因素的含量，以及分离株之间的系统发育关系（计算机多位点序列分型[MLST]和单核苷酸多态性[SNPs]分析）。
在所研究的分离株中，分别有30株和2株是耐万古霉素屎肠球菌（VREfm）和耐万古霉素粪肠球菌（VREfs）。总体而言，8株分离株（6株VREfm和2株VREfs）对TET耐药（8/32，25%），其中4株（均为VREfm）也对TGC和ERV耐药（4/32，12.5%）。两株对TET耐药的VREfs菌株属于序列类型（ST）6，仅携带tet（M）基因。所有对TET耐药的VREfm均为ST80，携带tet（L）和tet（M）基因。其中，4株对TGC耐药和对ERV耐药的菌株在核糖体S10蛋白（rpsJ基因）中出现罕见的Y58D替代。SNPs分析显示，携带Y58D的菌株在ST80 VREfm中形成一个单独的簇。
在本研究中，我们将rpsJ基因中Y58D突变的存在与一组VREfm ST80临床菌株对TGC和ERV的耐药性相关联。Y58D突变总是与tet（L）和tet（M）基因同时存在。
