First cases of infections caused by community-associated methicillin-resistant Staphylococcus aureus in Bulgaria
Abstract number: 1733_1081
Nashev D., Bizeva L., Toshkova K., Alexiev I., Beshkov D.
Objectives: We report first cases of skin infections caused by Panton-Valentine leukocidin (PVL) positive cMRSA strains in Bulgaria.
Methods: During 2005 and 2006 five cases of infection caused by MRSA with unusual susceptibility patterns and community onset were documented in our institution. The patients were young people with no history of previous MRSA isolation, no history of hospitalisation or invasive manipulations in the past year and without permanent medical devices. The skin infections were represented by furunculosis in 4 patients and cutaneous abscesses in one patient. MRSA were isolated from skin lesions as well as from anterior nares of 4 patients with furunculosis. Antibiotic susceptibility testing was performed according to CLSI. Methicillin-resistance was confirmed by latex agglutination test for PBP 2a and PCR detection of mecA gene. The presence of PVL genes (lukS-PV-lukF-PV) were assessed by PCR. The isolates were further analysed by spa-sequence typing, spa types were designated using Ridom Staphtype software®.
Results: All isolates in the present study were found positive for PVL genes. MRSA isolates from 4 patients belonged to spa type t008 and from one patient to spa type t044. In all 4 cases caused by t008 strain, nasal carriage of the strain with the same spa type was detected. The isolates belonging to t008 showed resistance to erythromycin, kanamycin, tetracycline and ciprofloxacin and were susceptible to fusidic acid. The isolate belonging to t044 were resistant to kanamycin, tetracycline as well as to fusidic acid. The existing sequence databases for spa types allowed specific spa types to be associated with particular MLST sequence type (ST). The isolates belonging to spa type t044 represent the major European cMRSA clone ST 80. MRSA isolates with spa type t008 are frequently associated with ST8. However, cMRSA isolates belonging to ST8 cannot be discriminated from hospital MRSA isolates of this lineage by spa sequence typing alone; they also exhibit t008. All patients were succefully treated with clindamycin or trimethoprim-sulfamethoxazole in combination with rifampin. Nasal carriage was supressed with intranasal mupirocin, but 3 months later in one patient recolonisation with the same t008, PVL positive strain occurred.
Conclusion: The appearance of the first cMRSA strains should raise a great concern about diagnosis and treatment of these infections in Bulgaria.
|Session name:||European Society of Clinical Microbiology and Infectious Diseases|
|Location:||ICC, Munich, Germany|
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