Molecular surveillance of methicillin-resistant Staphylococcus aureus by multiple-locus variable number tandem repeat fingerprinting (formerly multiple-locus variable number tandem repeat analysis) and spa typing in a hierarchic approach.
In this study, clonal relatedness of 202 Staphylococcus aureus (mostly methicillin-resistant) isolates recovered in 29 Polish hospitals was investigated by multiple-locus variable number tandem repeat fingerprinting (MLVF) and spa typing. Our analysis yielded 69 MLVF patterns and 34 spa types. Almost all isolates (97.4%) identical by MLVF were also indistinguishable by spa typing. Therefore, the MLVF method can be a cheap and fast screen before spa typing. Moreover, results obtained by MLVF suggest a set of simple criteria for grouping of spa types. The proposed algorithm groups isolates into the same cluster when spa sequences differ by a single mutation event: i) a single deletion or insertion of repeat unit(s) at the X region of the protein A gene or ii) a single nucleotide polymorphism within a repeat sequence. The combined use of these 2 methods, MLVF in local laboratories and spa typing of selected isolates in reference centers, can improve the monitoring of hospital-to-hospital strain transmission events and public health interventions on a huge scale.
Karynski
Michal
M
National Medicines Institute, Division of Clinical Microbiology and Infection Prevention, 00-725 Warsaw, Poland.
Sabat
Artur J
AJ
Empel
Joanna
J
Hryniewicz
Waleria
W
D000465:Algorithms; D015373:Bacterial Typing Techniques / Q000379:methods*; D016172:DNA Fingerprinting / Q000379:methods*; D030541:Databases, Genetic; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000235:genetics; D018598:Minisatellite Repeats; D011044:Poland / Q000453:epidemiology; D017422:Sequence Analysis, DNA / Q000379:methods; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*