We determined the value of spa typing in combination with BURP (based upon repeat pattern) grouping analysis as a frontline tool in the epidemiological typing of Staphylococcus aureus, based on a random collection of 1,459 clinical isolates sent to the German Reference Centre for Staphylococci within a 6-month period. The application was found to be helpful for the classification of isolates into the particular clonal lineages currently prevalent in Germany. Due to its major advantages because of the ease of interpretation and the exchangeability of the results, the use of spa typing greatly simplifies communication between laboratories on both the national and the international levels. Thus, it is an excellent tool for national and international surveillance of S. aureus as well as for analysis of the short-term local epidemiology. However, to overcome the limitations of the BURP grouping method in terms of typing accuracy and discriminatory power, the results of the default BURP grouping method must be interpreted with caution. Additional markers, like staphylococcal chromosomal cassette mec, lineage-specific genes, or alternative DNA polymorphisms, are indispensable. They should be selected by dependence on the clonal lineage indicated by spa typing and subsequent BURP analysis as well as on the basis of the particular question to be addressed.Staphylococcus aureus is well known both as a commensal organism on the human skin and as a leading cause of human disease responsible for a variety of diseases ranging from superficial skin infections to serious infections like pneumonia, bacteremia, and endocarditis (20). The occurrence and spread of methicillin-resistant S. aureus (MRSA) soon after the introduction of methicillin in clinical practice finally led to the appearance of hospital-adapted multiresistant clones, which constitute a constantly growing problem as a major cause of nosocomial infections all over the world (2, 5, 42). Additionally, the appearance of MRSA in the community (communityacquired MRSA [caMRSA]) and the potential risk of its introduction into hospitals are matters of great concern (5,16,31,34).The use of efficient and accurate epidemiological typing methods is a prerequisite for monitoring and for limiting the occurrence and spread of epidemic clones within and between hospitals. Therefore, typing systems must enable the discrimination between unrelated isolates as well as the recognition of isolates belonging to the same clonal lineage in order to determine whether epidemiologically related isolates are also genetically related (36, 38). Historically, typing of S. aureus mostly relied on phenotypic strain characteristics (for example, susceptibility to bacteriophages or antibiotics), but over the past two decades a variety of molecular technologies have been developed. Among those technologies, SmaI macrorestriction analysis became the "gold standard" for S. aureus strain typing mainly because of its excellent discriminatory power, especially for analysis of the local short-term epidemi...

The aim of the present study was to investigate strains of methicillin-resistant Staphylococcus aureus (MRSA) for the presence of the lukS-lukF determinant of Panton-Valentine leukocidin and to further characterize strains found to contain the genes. During the past 2 years, MRSA containing the lukS-lukF genes for Panton-Valentine leukocidin, particularly those emerging outside of hospitals, have become of interest. MRSA strains sent to the national reference center in Germany were investigated for lukS-lukF by polymerase chain reaction (PCR). If the presence of lukS-lukF was demonstrated, strains were further characterized by molecular typing (determination of SmaI pattern, spa sequence, and multilocus sequence type), PCR demonstration of resistance genes, and characterization of the SCCmec element. Since the end of 2002, MRSA containing Panton-Valentine leukocidin genes have been demonstrated as the causative agent of 28 cases of infection (9 community-acquired cases, 19 sporadic nosocomial cases) in different areas of Germany. Twenty-seven of these 28 isolates exhibited a unique pattern of genomic typing: all exhibited multilocus sequence type 80, spa sequence type 44, and a SmaI macrorestriction pattern that corresponds to a community-acquired strain of MRSA from France and Switzerland. In addition to resistance to oxacillin, the strains exhibited resistance to ciprofloxacin, tetracycline (tetM), and fusidic acid, the last of which is encoded by the far-1 gene. The far-1 gene was shown to be located on the plasmid. One isolate corresponded to community MRSA (cMRSA) of multilocus sequence type 1 from the USA.

caMRSA ST80 still predominate; however, caMRSA ST8 exhibiting the characteristics of the 'USA300' clone became the second most frequent. Routine detection of this clone in clinical bacteriology can be easily performed by PCR.

Analysis of community-acquired methicillin-resistant Staphylococcus aureus (c-MRSA) from Germany producing the Panton-Valentine leukocidin revealed a unique SmaI-macrorestriction pattern, different from epidemic nosocomial strains. This molecular pattern corresponds to those shown in c-MRSA strains from other countries in the European Union. All isolates exhibited resistance to fusidic acid, which is coded by the far-1 gene. From data on geographical dissemination and time of occurrence, this strain appears to have emerged in Germany in the second half of 2002, and so an already wider dissemination is likely. The emergence of MRSA with resistance to fusidic acid is a first sign of the emergence of a PVL-positive MRSA clone.

This report describes a successful strategy for terminating the transmission of epidemic strains of S. aureus among a nonhospitalized population.