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Background: Streptococcus pneumoniae and Haemophilus influenzae infections in children with influenza have been noted because of the severity of co-infection. In Japan, vaccination against S. pneumoniae and H. influenzae infections has been listed in the vaccine program in 2008, but the characteristics of the two organisms, colonizing at the initial stage of influenza infection, have not been investigated in detail. Methods: Nasopharyngeal swabs from children with influenza (flu+) ( n= 236; mean age, 6.2 years) were examined for bacterial pathogens, including S. pneumoniae and H. influenzae. They were then examined for serotypes, drug susceptibilities, and resistance genes (or gene mutations). As a reference, children with upper respiratory tract infection (URTI+, flu-; n = 189; mean age, 6.2 years) were also examined. Results: S. pneumoniae, β-streptococci (groups A, B, and G), methicillin-susceptible and -resistant S. aureus, Moraxella catarrhalis, and H. influenzae were isolated. For S. pneumoniae, nine serotypes were detected with prevalent types of 3, 6, 19 and 23. Penicillin resistance was detected in types 19 and 23, while resistance to macrolide and clindamycin was found in various types. For H. influenzae, only b serotype was detected, with marked ampicillin resistance. The majority was non-typeable. Very similar results were obtained even in URTI+ (flu-) cases. Conclusion: Multiple drug-resistant S. pneumoniae with major serotypes, for example, 19 and 23 and H. influenzae with serotype b were already present at the initial stage of influenza infection, similar to URTI+ flu- cases. They could be prevented by current vaccines, but drug-resistant non-typeable H. influenzae is troubling. [ABSTRACT FROM AUTHOR]

Abstract: Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) with Panton-Valentine leukocidin (PVL) genes is increasing worldwide. Nosocomial outbreak-derived (hospital-acquired) MRSA (HA-MRSA) in Japan in the 1980s was also largely PVL+. PVL+ HA-MRSA and CA-MRSA shared the same multi-locus sequence type (ST30) and methicillin resistance cassette (SCCmecIV), but were divergent in oxacillin resistance, spa typing, PFGE analysis or clfA gene analysis. PVL+ HA-MRSA, which probably originated in PVL+ S. aureus ST30, was highly adhesive (carrying cna and bbp genes), highly-toxic (carrying luk PV and sea genes) and highly drug-resistant. PVL+ HA-MRSA was once replaced by other PVL− HA-MRSA (e.g., ST5), and is re-emerging as CA-MRSA. [Copyright &y& Elsevier]

The major methicillin-resistant Staphylococcus aureus(MRSA) distributed among hospitals in Japan is New York/Japan clone [multilocus sequence type 5 (ST5), agr type 2 and methicillin resistance locus type (SCC mec) II] which possesses both the toxic shock syndrome toxin 1 gene (tst) and staphylococcal enterotoxin C gene (sec). In this study, we collected 245 MRSA strains from four hospitals during 2001 to 2005 in Niigata, Japan, and analyzed tst and sec genes and SCC mec type among them. A total of 13 strains were further examined for their genotypes, virulence gene patterns and drug resistance. Among the 245 strains four tst sec genes patterns were observed; tst(+) sec(+) strains represented a majority of 86.5% and 9.4% were tst(-) sec(-). SCCmec typing revealed that 91.4% had type II, 4.1% type IV and 4.1% type I. Multilocus sequence typing (MLST) revealed that 10 of the 13 typed strains belonged to clonal complex 5 (7 had ST5 while 3 were single locus variants of ST5) with similar characteristics to the New York/Japan clone and possessed multi-drug resistance with high virulence gene content. The remaining 3 strains were ST8 (n=2) and ST91 (n=1). The ST91 strain had SCC mec IV and seemed to originate in the community, while ST8 strains exhibited SCC mec type I, which is distinct from community type IV. The data suggest that MRSA in hospitals in Niigata now mainly includes the New York/Japan clone (undergoing genomic divergence and clonal expansion) and other minor types (e.g. ST8) as well as the community type.