Andrea Brenciani1, Gianluca Morroni1, Simona Pollini2, Erika Tiberi1, Marina Mingoia1, Pietro E Varaldo3, Gian Maria Rossolini4, Eleonora Giovanetti5. 1. Unit of Microbiology, Department of Biomedical Sciences and Public Health, Polytechnic University of Marche Medical School, Ancona, Italy. 2. Department of Medical Biotechnologies, University of Siena, Siena, Italy. 3. Unit of Microbiology, Department of Biomedical Sciences and Public Health, Polytechnic University of Marche Medical School, Ancona, Italy pe.varaldo@univpm.it. 4. Department of Medical Biotechnologies, University of Siena, Siena, Italy Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy Clinical Microbiology and Virology Unit, Florence Careggi University Hospital, Florence, Italy. 5. Unit of Microbiology, Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy.
Abstract
OBJECTIVES: The objective of this study was to investigate the genetic environment of the cfr gene from two linezolid-resistant clinical isolates of Staphylococcus epidermidis from Italy. METHODS: The two strains (SP1 and SP2) were phenotypically and genotypically characterized. Transferability of cfr was assessed by electrotransformation and conjugation. The genetic contexts of cfr were investigated by PCR mapping, sequencing and comparative sequence analyses. RESULTS: SP1 and SP2 belonged to ST23 and ST83, respectively. In both strains, the cfr gene was located on a plasmid, which could be transferred to Staphylococcus aureus by transformation and conjugation. In isolate SP1, linezolid resistance mediated by mutations in 23S rRNA and the L3 ribosomal protein was also detected. pSP01, the cfr-carrying plasmid from strain SP1, had a larger number of additional resistance genes and was sequenced (76 991 bp). It disclosed a distinctive mosaic structure, with four cargo regions interpolated into a backbone 95% identical to that of S. aureus plasmid pPR9. Besides cfr, resistance genes distributed in the cargo regions included blaZ, lsa(B), msr(A) and aad, and a gene cluster for resistance to heavy metals. A closely related cfr plasmid (pSP01.1, ∼ 49 kb), differing from pSP01 by the lack of a large cargo region with some resistance genes, was detected in strain SP2. CONCLUSIONS: The conjugative multiresistance plasmid pSP01 is the first cfr-carrying plasmid to be sequenced in Italy. This is the first time cfr has been found: (i) in association with blaZ, msr(A) and heavy metal resistance genes; and (ii) in an S. epidermidis strain (SP2) belonging to ST83.
OBJECTIVES: The objective of this study was to investigate the genetic environment of the cfr gene from two linezolid-resistant clinical isolates of Staphylococcus epidermidis from Italy. METHODS: The two strains (SP1 and SP2) were phenotypically and genotypically characterized. Transferability of cfr was assessed by electrotransformation and conjugation. The genetic contexts of cfr were investigated by PCR mapping, sequencing and comparative sequence analyses. RESULTS:SP1 and SP2 belonged to ST23 and ST83, respectively. In both strains, the cfr gene was located on a plasmid, which could be transferred to Staphylococcus aureus by transformation and conjugation. In isolate SP1, linezolid resistance mediated by mutations in 23S rRNA and the L3 ribosomal protein was also detected. pSP01, the cfr-carrying plasmid from strain SP1, had a larger number of additional resistance genes and was sequenced (76 991 bp). It disclosed a distinctive mosaic structure, with four cargo regions interpolated into a backbone 95% identical to that of S. aureus plasmid pPR9. Besides cfr, resistance genes distributed in the cargo regions included blaZ, lsa(B), msr(A) and aad, and a gene cluster for resistance to heavy metals. A closely related cfr plasmid (pSP01.1, ∼ 49 kb), differing from pSP01 by the lack of a large cargo region with some resistance genes, was detected in strain SP2. CONCLUSIONS: The conjugative multiresistance plasmid pSP01 is the first cfr-carrying plasmid to be sequenced in Italy. This is the first time cfr has been found: (i) in association with blaZ, msr(A) and heavy metal resistance genes; and (ii) in an S. epidermidis strain (SP2) belonging to ST83.
Authors: Ilaria Baccani; Alberto Antonelli; Vincenzo Di Pilato; Marco Coppi; Tiziana Di Maggio; Michele Spinicci; Ana Liz Villagran; Carmen Revollo; Alessandro Bartoloni; Gian Maria Rossolini Journal: Antimicrob Agents Chemother Date: 2021-07-16 Impact factor: 5.191
Authors: Stefan Schwarz; Wanjiang Zhang; Xiang-Dang Du; Henrike Krüger; Andrea T Feßler; Shizhen Ma; Yao Zhu; Congming Wu; Jianzhong Shen; Yang Wang Journal: Clin Microbiol Rev Date: 2021-06-02 Impact factor: 50.129
Authors: Gianluca Morroni; Andrea Brenciani; Alberto Antonelli; Marco Maria D'Andrea; Vincenzo Di Pilato; Simona Fioriti; Marina Mingoia; Carla Vignaroli; Oscar Cirioni; Francesca Biavasco; Pietro E Varaldo; Gian Maria Rossolini; Eleonora Giovanetti Journal: Front Microbiol Date: 2018-09-11 Impact factor: 5.640