The molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in the Czech Republic.

OBJECTIVES: To gain data on the current molecular epidemiology and resistance of MRSA in the Czech Republic. METHODS: Between September 2017 and January 2018, a total of 441 single-patient MRSA isolates were collected from 11 Czech hospitals and analysed by spa typing, SCCmec typing, antibiotic susceptibility testing, detection of the PVL toxin and the arcA gene. RESULTS: Of all MRSA isolates, 81.41% (n = 359) belonged to the CC5-MRSA clone represented by the spa types t003 (n = 136), t586 (n = 92), t014 (n = 81), t002 (n = 20) and other spa types (n = 30); a majority of the CC5 isolates (n = 348, 96.94%) carried SCCmec type II. The occurrence of CC5-MRSA was more likely in older inpatients and associated with a healthcare origin (P < 0.001). The CC5-MRSA isolates were resistant to more antimicrobial drugs compared with the other MRSAs (P < 0.001). Interestingly, t586 was detected in blood samples more often than the other spa types and, contrary to other spa types belonging to CC5-MRSA, t586 was not associated with patients of advanced age. Other frequently found lineages were CC8 (n = 17), CC398 (n = 11) and CC59 (n = 10). The presence of the PVL was detected in 8.62% (n = 38) of the MRSA isolates. CONCLUSIONS: The healthcare-associated CC5-MRSA-II lineage (t003, t586, t014) was found to be predominant in the Czech Republic. t586 is a newly emerging spa type in the Czech Republic, yet reported rarely in other countries. Our observations stress the need for MRSA surveillance in the Czech Republic in order to monitor changes in MRSA epidemiology.

Insufficient repeatability and reproducibility of MALDI-TOF MS-based identification of MRSA.

Rapid identification of methicillin-resistant Staphylococcus aureus (MRSA) is essential for proper initial antibiotic therapy and timely set up of hygienic measures. Recently, detection of MRSA using MALDI-TOF mass spectrometer mediated by the peptide-phenol-soluble modulin (PSM-mec)-linked to the class A mec gene complex present in SCCmec cassettes types II, III, and VIII of MRSA strains, has been commercially available. We present here a multicentre study on MALDI-TOF MS detection of MRSA evincing a poor repeatability and reproducibility of the assay. The sensitivity of the assay varies between 50 and 90% in strains carrying psmMEC and psmδ genes encoding for PSM-mec and δ-toxin (a member of the PSM peptide family), respectively. No false positive results were found. The very major error calculation was 30% and the major error achieved 0%. Interlaboratory repeatability varies between 0 and 100%. No significant difference was observed with the use of different cultivation media. Our data showed a poor sensitivity of the method excluding it from the use in routine laboratory testing.

Antibiotic Resistance in Nosocomial Bacteria Isolated from Infected Wounds of Hospitalized Patients in Czech Republic.

Hospitalized patients with wounds face an increased risk of infection with multi-drug-resistant nosocomial bacteria. In this study, samples from almost 10,000 patients from big hospitals in Czech Republic with infected wounds were analyzed for the presence of bacterial pathogens. In 7693 patients (78.8%), bacterial etiological agents were identified. Members of the Enterobacterales (37.1%) and Staphyloccus aureus (21.1%) were the most prevalent pathogens. Staphyloccus aureus showed methicillin resistance in 8.6%. Almost half of the Klebsiella pneumoniae isolates were ESBL-positive and 25.6% of the Enterobacter spp. isolates were AmpC-positive. The third most prevalent Pseudomonas aeruginosa showed resistance to 19-32% of the antipseudomonal antibiotics tested. Based on the results, amoxicillin/clavulanic acid, ampicillin/sulbactam or piperacillin/tazobactam combined with gentamicin can be recommended for antibiotic treatment of infected wounds. Once the etiological agent is identified, the therapy should be adjusted according to the species and its resistance.

Epidemiological characteristics of methicillin-resistant Staphylococcus aureus isolates from bloodstream cultures at University Hospital in the Czech Republic.

The aim of this study was to trace the dynamic changes of methicillin-resistant Staphylococcus aureus (MRSA) lineages in the local hospital in both the national and international context. We describe genotypic and phenotypic characterization of 62 non-duplicate MRSA isolates collected during 2010-2016 at University Hospital in Hradec Kralove, Czech Republic. The isolates were characterized by multilocus sequence typing (MLST), spa typing, and staphylococcal cassette chromosome mec typing (SCCmec typing). Eight different genotypes were described; ST225-t003-II (32/62, 52%), ST5-t002-II (13/62, 22%), and ST225-t014-II (12/62, 21%) were constantly detected over the 7-year follow-up period. The genotypes ST225-t151-II, ST225-t1282-II, ST225-t1623-II, ST78-t2832-II, and ST225-t8799-II occurred only once in the period reported. The majority of the strains, represented by ST225, belonged to clonal complex 5 (CC5).

Methicillin-resistant Staphylococcus aureus in veterinary professionals in 2017 in the Czech Republic.

BACKGROUND: Cases of colonization or infection caused by Methicillin-resistant Staphylococcus aureus (MRSA) are frequently reported in people who work with animals, including veterinary personnel. The aim of this study was to determine the prevalence of MRSA colonization among veterinary professionals. A total of 134 nasal swabs from healthy attendees of a veterinary conference held in the Czech Republic were tested for presence of MRSA. The stains were further genotypically and phenotypically characterized. RESULTS: Nine isolated MRSA strains were characterized with sequence type (ST), spa type (t) and Staphylococcal Cassette Chromosome mec type. Five different genotypes were described, including ST398-t011-IV (n = 5), ST398-t2330-IV (n = 1), ST398-t034-V (n = 1), ST225-t003-II (n = 1) and ST4894-t011-IV (n = 1). The carriage of the animal MRSA strain was confirmed in 8 cases, characteristics of one strain corresponded to the possible nosocomial origin. Among animal strains were described three spa types (t011, t034, t2330) belonging into one dominating clonal complex spa-CC11. CONCLUSION: According to our results, the prevalence of nasal carriage of MRSA in veterinary personnel is 6.72%. Although we described an increase compared to the results of previous study (year 2008), the prevalence in the Czech Republic is still remaining lower than reported from neighboring countries. Our results also indicate that healthcare - associated MRSA strains are still not spread among animals.