[A multicenter study of the antimicrobial susceptibility of Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae, and Moraxella catarrhalis from community acquired infections in Saitama, Japan].

We examined regional surveillance of antimicrobial susceptibility of community acquired bacterial pathogens from patients in Saitama, Japan. The fourth-year survey was conducted in three of the period 2007-2010 (period I, 2007-2008; period II, 2008-2009; period III, 2009-2010). Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Japanese Society of Chemotherapy using maximum 13 antibacterial agents. Susceptibility testing was evaluable with 789 strains (227 Streptococcus pneumoniae, 148 Streptococcus pyogenes, 220 Haemophilus influenzae, and 194 Moraxella catarrhalis). Ratio of penicillin-susceptible S. pneumoniae (PSSP, MIC of benzylpenicillin ≤ 0.06 µg/mL) was 43.5% (period I), 43.5% (period II) and 55.8% (period III), and those of erythromycin-sensitive and azithromycin-sensitive S. pyogenes were 100% and 65.5% (period I), 47.9% and 47.9% (period II), 29.4%, and 29.4% (period III) , respectively. Among H. influenzae, ß-lactamase-nonproducing ampicillin-resistant isolates were 34.9% (period I), 25.8% (period II), and 17.1% (period III); however, ß-lactamase-nonproducing ampicillin-intermediately resistant isolates were 19.8% (period I), 26.9% (period II), and 29.3% (period III). Regarding M. catarrhalis, macrolides showed potent activities, with MIC90s of ≤ 0.25-0.5 µg/mL, and fluoroquinolones showed strong activities, with MIC90s ≤0.03-0.125 µg/mL. The result of this survey indicated that the trends observed were similar to the results of previous nationwide surveillance.

False positive of an immunochromatography kit for detection of norovirus in neonatal feces.

Norovirus was detected in the feces from five neonates in the growing care unit by a rapid immunochromatography (ICG) kit. However, confirmation using reverse transcription polymerase chain reaction (RT-PCR), RT-loop-mediated isothermal amplification (RT-LAMP), and nested RT-PCR methods showed negative results from all the feces. In addition, the ICG test for the detection of norovirus was positive for four cases out of the 16 feces from other asymptomatic neonates/infants. Only one feces out of the four samples was positive by RT-LAMP. In this study, among the factors related to false positives with the norovirus ICG kit, there were no differences regarding the commencement of feeding, nutrition, and sample collection methods. Since the false positive rate of ICG in the diagnosis of norovirus infection in neonates and early infancy is high, ICG is not an appropriate method, and it is necessary to confirm the results using reliable methods like RT-PCR.