Skin lesion caused by ST398 and ST1 methicillin-resistant Staphylococcus aureus in a young girl in Spain and MRSA nasal colonisation study in their family members

Abstract number: P1569

Aspiroz C., Lozano C., Vindel A., Lasarte J.J., Zarazaga M., Torres C.

A 12 years old Ecuadorian girl, living close to a pig farm where her father was working, presented an skin lesion on her chin (June 2008), firstly assumed as a case of Tinea but dermathopytes could not be recovered, and this diagnosis was later discarded. Two types of MRSA were the unique organisms that could be recovered from the lesion and they were characterised by MLST, SCCmec and spa typing and were identified as ST398-SCCmecV-t011 and ST1-SCCmecII-t127, being both isolates negative for the Panton Valentine leukocidin. The ST398 strain showed resistance to penicillin, oxacillin, tetracycline, erythromycin, clindamycin and telithromycin and contained the mecA, tetK, ermA, and ermC genes. The ST1 strain showed the above mentioned resistances and genes, and in addition included gentamicin, tobramycin, kanamycin, ciprofloxacin, levofloxacin and trimethoprim-sulphamethoxazole resistances and msrA, ermB, tetL, ant(4')(4"), aph(2")-aac(6') genes, as well as a Ser84Leu amino acid change in GyrA and a Ser80Phe change in ParC protein. The skin lesion was resolved after topical treatment with mupirocin during ten days. An epidemiological study was started in order to know the nasal colonisation status of the family members, using nasal swabs that were streaked in ORSAB medium (Oxoid) for MRSA recovery and obtained isolates where characterised by MLST, SCCmec and spa typing. The following family members turned out to be colonised by MRSA: patient girl (ST398-SCCmecV-t108), father (ST398-SCCmecV-t108), mother (ST398-SCCmecV-t108 and ST1-SCCmecII-t127), and brother (ST398-SCCmecV-t011). Most of ST398 nasal isolates presented the phenotype of resistance that included b-lactams, macrolides, clindamycin, telithromycin and tetracycline. The nasal ST1-t127 isolate recovered from the mother showed the same phenotype and genotype of resistance that ST1-t127 strain recovered in the skin lesion of the girl. All isolates were negative for TSST, ETA-a y ETA-b toxins.

Conclusion: The first case of an skin lesion associated with ST398-t011 and ST1-t127 MRSA isolates is reported in Spain in the daughter of a pig farmer. Of special interest is the multiresistant-phenotype showed by the ST1-t127 MRSA clinical isolate. Nasal colonisation by different ST398 genetic lineages of MRSA seems to be frequent in persons that live close to pig farms. Dissemination of ST398-MRSA in humans, associated with animals, is an emerging problem that should be tracked in the future.