Author : H. Obayes, Mohammed
Molecular study of Methicillin Resistant Staphylococcus lugdunensis (MRSL) Isolates in Hilla city, Iraq
karbala journal of pharmaceutical sciences,
2013, Volume 4, Issue 6, Pages 117-126
Out of 690 clinical samples collected from different site (wound, burn, blood culture, sub axillary, urine, stool , sputum, throat, ear, skin lesion, high vaginal, and other different swabs), a total of 178 coagulase negative Staphylococci (CoNS) isolates were recovered. Based on phenotypic characteristics, CoNS were identified into 10 different species; 22 isolates were belonged to Staphylococcus lugdunensis. Two specific genes for S. lugdunensis were used (tanA gene and fbl gene) to confirm identification. Both of these specific genes were detected in 15 (68.1 %) of 22 isolates that identified phenotypically. The remaining 7 isolates (31.9 %) were re-identified as S. pseudolugdunensis. β-lactam resistance screening test showed that 11 (73.3 %) of S. lugdunensis isolates were ampicillin resistant. The results of oxacillin screening test and Oxacillin MIC showed that 7 of the 15 (46.6 %) S. lugdunensis isolates were oxacillin resistant; all these were resistant to ampicillin. The antibiotic susceptibility test by Disc Diffusion test and MIC to 16 antibiotics showed that resistance rates towards these antibiotics. Eight of fifteen S. lugdunensis isolates (53.3 %) were β-lactamase producer. All these isolates were Ampicillin resistant.
Results of mecA gene found that mec A gene was detected in 6 (40 %) of 15 S. lugdunensis. All of these 6 isolates (S1, S2, S3, S4, S5, and S6) were resistant to oxacillin. One isolate (S7) was resistant to Oxacillin but mecA was not detected in this isolates. This study is a first record of isolation and characterization of MRSL form clinical samples in Iraq.