Genetic polymorphism of Staphylococcus epidermidis strains in patients of the Neonatal Intensive Care Unit

About authors

1 Department of Microbiology and Clinical Pharmacology,
Kulakov Research Center for Obstetrics, Gynecology and Perinatology, Moscow, Russia

2 Department of Clinical and Molecular Genetics,
Kulakov Research Center for Obstetrics, Gynecology and Perinatology, Moscow, Russia

3 Department of Neonatology and Pediatrics,
Kulakov Research Center for Obstetrics, Gynecology and Perinatology, Moscow, Russia

Correspondence should be addressed: Alexey B. Gordeev
ul. Akademika Oparina, d. 4, Moscow, Russia, 117997; ur.sertorp.agev@weedrog

About paper

Funding: this study was supported by the Grant Agreement No. 14.607.21.0019 of the Ministry of Science and Education of the Russian Federation
dated June 5, 2014 (ID 2014-14-579-0001-065).

Contribution of the authors to this work: Gordeev AB — bioinformatics analysis of nucleotide sequences, analysis of literature, drafting of a manuscript; Lyubasovskaya LA — micribiological studies, analysis of literature, data interpretation, drafting of a manuscript; Rodchenko JV, Dubodelov DV — microbiological studies, drafting of a manuscript; Mukosey IS, Kochetkova TO — whole genome suquencing and genome assembling; Nikitina IV — research planning, data interpretation; Ionov OB, Zubkov VV — research planning, organization of biomaterial sampling; Trofimov DYu — research planning, organization of whole genome sequencing; Priputnevich TV — research planning, organization of microbiological studies, data interpretation, drafting of a manuscript. All authors participated in editing of the manuscript.

Received: 2017-02-02 Accepted: 2017-02-18 Published online: 2017-03-11

Staphylococcus epidermidis is a member of the normal bacterial flora of humans capable of causing potentially dangerous diseases in neonates with very or extremely low birth weight. The number of genes responsible for virulence and antibiotic resistance may vary in different S. epidermidis strains. We sequenced isolates of S. epidermidis to explore genetic diversity of 14 strains circulating in the Neonatal Intensive Care Unit of Kulakov Research Center for Obstetrics, Gynecology and Perinatology. Among the studied strains, 8 sequence types were identified, the most frequent being ST2 and ST59, both of which belong to the clonal complex CC2. Of 14 studied strains, 10 were of CC2 type. The studied strains revealed a variety of genes responsible for antibiotic resistance. We found 15 genes that provided resistance to aminoglycosides, beta-lactam antibiotics, fusidic acid, macrolides, lincosamides, streptogramin B, tetracycline, and trimethoprim. We identified a number of genes associated with virulence (aae, atlE, aap, embp), whose frequency in the studied isolates was varied. The insertion element IS256 was detected in 9 strains, and 7 strains revealed the presence of the ica-operon responsible for the biosynthesis of the biofilm matrix proteins.

Keywords: resistance, polymorphism, pathogenicity, Staphylococcus epidermidis, neonates, sequence type, whole genome sequencing