title: Analysis of nosocomial Staphylococcus haemolyticus by MLST and MALDI-TOF mass spectrometry.
abstract: Coagulase-negative staphylococci (CoNS) are a major component of normal human skin and mucosae flora. However, some species of CoNS can lead to infections in immunocompromised patients and premature newborns. The choice of a rapid and reliable typing method is one of the major problems in the epidemiological monitoring of CoNS, especially Staphylococcushaemolyticus isolates. In this study, we have tested 71 isolates of S. haemolyticus obtained from newborns using the multilocus sequence typing (MLST) and the direct bacterial MALDI-TOF mass spectrometry profiling approaches. To date, there is no standard MLST scheme for investigating the diversity of S. haemolyticus strains. The novel variant of MLST scheme including the tpiA, pta, sh1200, rphE, tphK, mvaK1, and arc loki was tested. The discriminatory power was estimated by the Hunter-Gaston discriminatory index (D) as 0.95. The Composition Correlation Index Matrix (CCI matrix) was calculated to typing the isolates through the analysis of mass spectra; also, the values of the correlation index for different groups of isolates were evaluated. Closely related isolates obtained from the same hospital are characterized by increased values of correlation indices in comparison with these values of isolates collected from various hospitals. The data obtained by both methods allow to describe a clonal structure of S. haemolyticus population and to designate the presence of endemic clones of S. haemolyticus.
authors.affiliation: Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia. Electronic address: kornienkomariya@gmail.com.
authors.forename: Maria
authors.initials: M
authors.lastname: Kornienko
authors.affiliation: Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia.
authors.forename: Elena
authors.initials: E
authors.lastname: Ilina
authors.affiliation: Federal State Budget Institution Research Center for Obstetrics, Gynecology and Perinatology, Moscow, Russia.
authors.forename: Ludmila
authors.initials: L
authors.lastname: Lubasovskaya
authors.affiliation: Federal State Budget Institution Research Center for Obstetrics, Gynecology and Perinatology, Moscow, Russia.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Priputnevich
authors.affiliation: Ulyanovsk State Technical University, Ulyanovsk, Russia.
authors.forename: Oksana
authors.initials: O
authors.lastname: Falova
authors.affiliation: Federal State Budget Institution Research Center for Obstetrics, Gynecology and Perinatology, Moscow, Russia.
authors.forename: Gennadiy
authors.initials: G
authors.lastname: Sukhikh
authors.affiliation: Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia.
authors.forename: Vadim
authors.initials: V
authors.lastname: Govorun
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques / Q000379:methods; D003428:Cross Infection / Q000382:microbiology*; D014644:Genetic Variation; D006801:Humans; D007231:Infant, Newborn; D058885:Multilocus Sequence Typing / Q000379:methods*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013203:Staphylococcal Infections / Q000175:diagnosis*; D041162:Staphylococcus haemolyticus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins
keywords: Coagulase-negative staphylococci; MALDI-MS; MLST; Staphylococcus haemolyticus; Typing method