[Differentiation of spa types and staphylococcal cassette chromosome mec (SCCmec) in clinical methicillin-resistant Staphylococcus aureus isolated in medical sites of Gdansk region]. / Zrónicowanie typów spa i kaset SCCmec u klinicznych szczepów Staphylococcus aureus opornych na metycyline izolowanych w osrodkach regionu gdanskiego.

INTRODUCTION: Methicillin-resistant Staphylococcus aureus bacteria are one of the key etiological factors of hospital-acquired and community-acquired infections. MRSA strains have an ability of causing a broad spectrum infections: from a relatively mild skin infections to severe life-threatening systemic infections. They are characterized by multi-drug resistance, virulence of a number of factors, may clonally spread within the hospitals and between hospitals. METHODS: The study embraced a number of 75 isolates of MRSA isolated from patients of 7 medical sites of the Gdansk region within the period of six months (June to December 2013). Strains have derived from various clinical materials, both of hospitalized patients (n=59) and outpatient (n=16). The isolates were tested for the susceptibility to antimicrobial agents accordance with the guidelines EUCAST. To estimate of the variability of occurrence of S. aureus clones used were standard spa gene, consisting in the amplified polymorphic region of the X gene encoding the protein A gene (spa). After receiving the results, a spa types were identified using international database Ridom Spa Server (www.spaserver.ridom.de). To determine the polymorphism cassette carrying the inecA gene from MRSA strains, used typing five major chromosomal cassette SCCmec (I-V) by multiplex PCR. RESULTS: MRSA population genetic analysis carried out on the basis of typing SCCmec cassettes and spa gene has showed a predominance of strains with SCCmec type II casette (46.7%) and SCCmec IV casette (38.7%). Less frequently detected were strains containing SCCmec I cassette (12.0%) and SCCmec III cassette (2.6%). Spa typing revealed the presence of 13 gene types in MRSA. The most frequently observed spa types were: t151 (24.0%), t003 (16.0%) in strains of the SCCmec II cassette and t437 (16.0%) and t008 (14.8%) in the isolates with SCCmec cassette IV, whereas staphylococcus with the type of spa t011 (12.0%) had SCCmec cassette I. CONCLUSIONS: In our population most frequent strains cassette SCCmec II (46.7%), in most representing types of spa t151 (51.4%) and t003 (34.3%), generally resistant not only to ß-lactam antibiotics, but as erythromycin, clindamycin and norfloxacin (82.8%), the more frequently they were isolated from patients than a hospital outpatient centers. The strains SCCmec IV that represent the majority of outpatient centers (68.8%), the most represented type t437 (41.4%) and often occurred in hospital centers.

Clonal distribution of bone sialoprotein-binding protein gene among Staphylococcus aureus isolates associated with bloodstream infections.

Staphylococcus aureus is a leading cause of bloodstream infections (BSI) and diseases that may be caused by hematogenous spread. The staphylococcal adhesin, for which the association with the infections emerging as a complication of septicemia has been well documented, is a bone sialoprotein-binding protein (Bbp). The aim of the study was to assess the prevalence of a bbp gene in S. aureus bloodstream isolates associated with BSI and to investigate to what degree the distribution of this gene is linked to the clonality of the population. Spa typing, used in order to explore the genetic population structure of the isolates, yielded 29 types. Six spa clusters and seven singletons were identified. The most frequent was spa clonal complex CC021 associated with MLST CC30 (38%). The bbp gene was found in 47% of isolates. Almost all isolates (95%) clustered in spa clonal complex CC021 were positive for this gene. All isolates carrying the bbp gene were sensitive to methicillin, and if clustered in the spa CC021, belonged to agr group III. Our study shows that Bbp is not strictly associated with BSI. However, one may conclude that for clonally related S. aureus strains most commonly causing BSI, the risk of Bbp-mediated complications of septicemia is expected to be higher than for other strains.

[Spa types and antibiotic resistance of Staphylococcus aureus bloodstream isolates obtained form patients of the University Clinical Center in Gdansk]. / Typy spa i lekoopornosc szczepów Staphylococcus aureus izolowanych z krwi pacjentów Uniwersyteckiego Centrum Klinicznego w Gdansku.

INTRODUCTION: Staphylococcus aureus is a leading cause of bloodstream infections. For epidemiological investigations of this bacteria spa genotyping is used as the method which has a high discriminatory power and gives results that can be easily compared between laboratories. In contrast to methicillin-resistant S.aureus (MRSA), relatively little is known about spa types among methicillin-susceptible strains (MSSA). We used spa typing and antibiotic resistance patterns analysis for retrospective study of S.aureus bloodstream isolates population from the University Clinical Centre (UCC) in Gdansk. METHODS: The study was performed on 53 isolates from patients of 19 different units/ departments of the UCC. The isolates were tested for the susceptibility to antimicrobial agents. Spa typing was performed on the basis of the sequence analysis of the polymorphic X region of the protein A gene (spa) amplified form the isolates. Spa types were determined by Ridom Staph Type software and were clustered into spa-CCs (clonal complexes) using the algorithm BURP-based upon repeat pattern. MLST (Multilocus Sequence Typing) clonal complexes were predicted from BURP analysis by the Ridom SpaServer database. In MRSA the staphylococcal chromosomal casette (SCC) mec was determined, RESULTS: Spa-typing yielded 26 types. Six spa-CC and seven singletons were identified. The most frequent was spa-CC021involving 38% of isolates. The CC021 consisted of 7 spa types and the most common was t021 corresponding with MLST-CC30. The second frequent was singleton, related to MLST-CC1, with only one type t127. There were 3 MRSA isolates in the population. The MRSA strains were identified as different spa types: t003/ SCCmecII, t008/SCCmecIV and clonally related to MSSA t032/SCCmecIV. No one MRSA strains belonged to spa-CC021. CONCLUSIONS: The spa clonal cluster corresponding with widely distributed among invasive S.aureus strains in Europe MLST-CC30 was found as the most frequent among S.aureus bloodstream isolates from the UCC. Occurrence of spa types which had a genetic background common to well known MRSA clonal lineages was observed.

The use of spa and phage typing for characterization of clinical isolates of methicillin-resistant Staphylococcus aureus in the University Clinical Center in Gdansk, Poland.

The emergence of spa types and spa-clonal complexes (CC) among clinical methicillin-resistant Staphylococcus aureus isolates collected from the University Clinical Center in Gdansk between 2008 and 2009 were investigated. Phage typing was used as the initial screening in the study. The basic set of phages and the additional set of phages were used. Most of the isolates (56 %) belonged to the phage group III. With the additional set of phages, eight types were found, with predominant one MR8 (50 %). Sixteen distinct spa types were observed. The most frequent were t003 (22 %), t151 (16 %), and t008 (12 %). The spa types were clustered into two spa-CC and eight singletons. The predominant CC010 (50 %) consisted of six types, with the most common t003 (36.7 %) and t151(26.7 %), and in 80 % was identified as staphylococcal chromosomal casette mec (SCCmec) type II. The second cluster has no founder (12 %) with only two spa types: t037 belonging to SCCmec type III and t029. In the most frequent singleton, spa type t008 alone was clustered in 12 % of the isolates. All singletons correspond to SCCmec type IV. The CC010 was distributed in most of the hospital wards, corresponded to Multilocus sequence typing type ST5/ST225 and was constantly present throughout the observed period. The isolates of CC010 generally belonged to the phage group III, and most of them (53.3 %) were resistant to erythromycin, clindamycin, and ciprofloxacin. The concordance between spa-clone and phage type was very high, but the same phage type MR8 was observed within different spa types of the predominant clone.