| Sažetak | Tema ovoga rada je bakterija Staphylococcus aureus rezistentna na meticilin (MRSA). Obrađivat će se mikrobiološke karakteristike MRSA, epidemiološke karakteristike, genski profil, rezistencija na antibiotike i terapijske opcije općenito, te usporedba istih specifičnosti MRSA za Hrvatsku. Za izradu rada korišteno je stotinu i šezdeset sedam izolata prikupljenih u razdoblju od 1.11. do 31.12. 2014. godine te dostavljenih u Klinički bolnički centar Zagreb, Klinički zavod za kliničku i molekularnu mikrobiologiju. Uzorci iz kojih je izolirana MRSA potječu iz različitih sustava: 57 iz respiratornog sustava (trahealni aspirat, bronhoalveolarni lavat, nos, ždrijelo..), 60 uzoraka iz rana, 6 hemokultura, i 39 ostalih, među kojima 16 iz uzoraka urina. Identifikacija izolata kao SA potvrđena je korištenjem uređaja MALDI TOF MS firme Bruker Daltonics. Testiranje osjetljivosti na antimikrobne lijekove provedeno je prema EUCAST standardima, i to na sljedeće antibiotike: penicilin, cefoksitin, klindamicin, eritrocimin, gentamicin, amikacin, ciprofloksacin, ko-trimoksazol, tetraciklin, rifampicin, linezolid, mupirocin i vankomicin, a testiranje na ceftarolin je provedeno određivanjem minimalne inhibitorne koncentracije putem E-testa. Provedeno je molekularno testiranje na mecA gena, SCCmec tipizacija, detekcija Pantone Valentine toksina (PVL). Svi sojevi osjetljivi su na linezolid, vankomicin, i teikoplanin, 3 izolata bila su rezistentna na ko-trimoksazol, rezistencija na ciprofloksacin zabilježena je u 87,4 % izolata. Profili rezistencije za 12 izolata ukazivali su na tipične izvanbolničke MRSA (CA MRSA). Sojevi nisu bili multirezistentni jer su osjetljivi na sve testirane antibiotike, osim cefoksitina, pa i eritromicin i klindamicin. Od ispitanih sojeva, 7 od 12 bilo je osjetljivo na ciprofloksacin. Nemultirezistentni MRSA sojevi su tipizirani kao SCCmec IV i V, predominantno spa t008, te t005, t1139, t011 i t355. Također, 5 od 12 ne-multirezistentnih bilo je PVL pozitivno, a PVL pozitivni izolati su imali spa tip t008 , osim jednoga koji je bio t355. Godine 2014, prevalencija CA MRSA bila je 7,4 %, što je značajno više u usporedbi s 2004. godinom, kad smo imali 1,61 % CA MRSA u Hrvatskoj. Dominantni SCCmec tipovi su tip II i I, kao i SCCmecIV. Rezultat veće prevalencije objašnjavamo time da je moguće došlo do transfera CA MRSA iz zajednice u bolničku sredinu, tipičnim skupinama bolesnika koji su se uglavnom povezivali s HA MRSA. |
| Sažetak (engleski) | The topic of this paper is a bacterium called methicillin-resistant Staphylococcus aureus (MRSA). We will discuss MRSA’s microbiological characteristics, epidemiological characteristics, genetic profile, antibiotic resistance and therapeutic options in general and then compare these with the same properties of MRSA found in Croatia. For the purpose of writing this paper, 167 isolates were collected and delivered to the University Hospital Centre in Zagreb, Department of Clinical and Molecular Microbiology in the period from 1 November to 31 December 2014. The samples from which MRSA was isolated had come from various systems: 57 from the respiratory tract (tracheal aspirate, bronchoalveolar lavage, nose, pharynx, etc.) 60 from wound samples, 6 from blood culture and 39 from other sources, 16 of which had been from urine. Identification of isolates as S.aureus was carried out by using the Bruker Daltonics MALDI TOF machine. EUCAST standards were used for antimicrobial drug sensitivity testing, and the antibiotics tested were as follows: penicillin, cefoxitin, clindamycin, erythromycin, gentamicin, amikacin, ciprofloxacin, co-trimoxazole, tetracycline, rifampicin, linezolid, mupirocin and vancomycin, while ceftaroline testing was performed by determining minimum inhibitory concentrations with the help of the Etest. Molecular tests for the mecA gene, SCCmec type determination, and Panton Valentine toxin (PVL) were also carried out. All strains were sensitive to linezolid, vancomycin and tetracycline, 3 isolates were resistant to co-trimoxazole, and ciprofloxacin resistance was observed in 87,4% of the isolates. The resistance profiles of 12 isolates were proved to be community-associated MRSA (CA MRSA) strains. The strains were non-multiresistant because of their sensitivity to all of the tested antibiotics, even to clindamycin and erythromycin, except to cefoxitin. Out of those 12 strains, 7 were sensitive to ciprofloxacin. Non-multiresistant MRSA strains were classified as SCCmec types IV i V, predominantly as spa t008, t005, t1139, t011 and t355. Furthermore, 5 out of 12 non-multiresistant strains were PVL positive, and those PVL positive isolates were spa type t008, except for one, which was t355. In 2014, the CA MRSA prevalence was 7,4%, which is significantly higher in comparison to 2004, when the prevalence of CA MRSA in Croatia was 1,61%. The dominant SCCmec types were type II and IV. The higher prevalence might be a result of transmission of CA MRSA from the community to hospital environments, to typical hospital patients that were generally HA MRSA positive. |
