Impact of the pneumococcal conjugate vaccine on serotype distribution of adult non-invasive Streptococcus pneumoniae isolates in Tokai region, Japan, 2008-2016.

The introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in February 2010 markedly reduced the burden of invasive pneumococcal disease and changed serotype distribution in Japan. In November 2013, PCV7 was replaced by the 13-valent pneumococcal conjugate vaccine (PCV13). We investigated the serotype distribution and susceptibility trends of non-invasive Streptococcus pneumoniae isolates collected from adult patients. A total of 504 pneumococcal isolates were collected during 4 periods between 2008 and 2016 (Period 1; between June 2008 and April 2009, Period 2; between September 2010 and March 2011, Period 3; between October 2011 and March 2012, Period 4; between August 2015 and January 2016). The coverage of PCV7 and PCV13 significantly decreased from 38.6% and 60.5% in Period 1 to 6.6% and 31.1% in Period 4. This change was mainly due to a large decrease in the frequency of serotype 19F, 6B, and 14. Serotype 3 was the most frequently isolated, and gradually increased. Additionally, non-PCV13 serotypes 11A, 33F, and 35B significantly increased. Most of the PCV7 serotypes 19F, 23F, 6B, and 14 had mutations of penicillin-binding protein genes and macrolide resistance genes, and these serotypes showed low susceptibilities to cefdinir and clarithromycin. On the other hand, a significant change in susceptibility to various antimicrobial agents was not observed throughout the study period, except for decreased susceptibility to carbapenems. Continuous surveillance studies of pneumococcal serotype changes and drug susceptibility are necessary in future.

[Sensitivity surveillance of Streptococcus pneumoniae isolates for several antibacterial agents in Gifu and Aichi prefectures (2011-2012)].

We investigated the susceptibility to antibacterial agents, genotype of penicillin-binding protein (PBP) genes and macrolide resistant genes, and the serotypes against 270 strains of Streptococcus pneumoniae isolated from medical facilities in Gifu and Aichi prefectures between October 2011 and April 2012. These results were compared with those against S. pneumoniae isolated in 2008-2009 and 2010-2011. The number of gPSSP with 3 normal PBP genes, gPISP with 1 or 2 normal PBP genes and gPRSP with 3 abnormal genes isolated in 2011-2012 was 15 (5.6%), 162 (60.0%) and 93 (34.4%) strains, respectively. Compared with those isolated in 2008-2009 and 2010-2011, the numbers of gPRSP were decreasing. On the other hand, the isolates with no macrolide-resistant gene, only mefA, only ermB, and both mefA and ermB were 16 (5.9%), 75 (27.8%), 153 (56.7%) and 26 (9.6%). Compared with those isolated in 2008-2009 and 2010-2011, the numbers of isolates with ermB, which was usually associated with high-level resistance, were increasing. The prevalent pneumococcal serotypes in children were type 3 (14.4%), following by type 15 and 19F (9.3%). The coverages of 7-valent pneumococcal conjugate vaccine (PCV7) and 13-valent pneumococcal conjugate vaccine (PCV13) were calculated as 22.9% and 49.2%, respectively. The coverages of PCV7 and PCV13 in gPRSP isolated from children were 47.7% (21/44 strains) and 72.7% (32/44 strains). The MIC90 of each antibacterial agent was as follows; 0.125pg/mL for imipenem, panipenem and garenoxacin, 0.25 µg/mL for meropenem and doripenem, 0.5 µg/mL for cefditoren, moxifloxacin and tosufloxacin, 1 µg/mL for amoxicillin, clavulanic acid/amoxicillin, cefteram, cefcapene and ceftriaxone, 2 µg/mL for benzylpenicillin, ampicillin, sulbactam/ampicillin, piperacillin, tazobactam/piperacillin and levofloxacin, 4 µg/mL for cefdinir, flomoxef and pazufloxacin, 16 µg/mL for minocycline, > 64 µg/mL for clarithromycin and azithromycin, and these MIC90s were about the same as those in 2010-2011.

Structural analysis of cerebrosides from Aspergillus fungi: the existence of galactosylceramide in A. oryzae.

Glucosylceramide and galactosylceramide were detected in three Aspergillus species: Aspergillus oryzae, Aspergillus sojae and Aspergillus. awamori, using borate-coated TLC. The cerebrosides from A. oryzae were further purified by ion exchange and iatrobeads column chromatographies with or without borate, and determined the composition of sugar, fatty acid and sphingoid base by GC/MS, MALDI-TOF/MS and (1)H-NMR. We identified them as ß-glucosylceramide and ß-galactosylceramide. The ceramide moiety of both cerebrosides consisted mainly of 2-hydroxystearic acid and either 9-methyl-octadeca-4, 8-sphingadienine or octadeca-4, 8-sphingadienine. To our knowledge, this is the first study to provide evidence for the presence of ß-galactosylceramide in A. oryzae.

Impact of the pneumococcal conjugate vaccine on serotype distribution and susceptibility trends of pediatric non-invasive Streptococcus pneumoniae isolates in Tokai, Japan over a 5-year period.

Introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in February 2010 markedly reduced the burden of invasive pneumococcal disease (IPD) and changed serotype distribution in Japan. We investigated the serotype distribution and susceptibility trends of non-invasive Streptococcus pneumoniae isolates collected from pediatric patients. A total of 564 pneumococcal isolates were collected over a 5-year period between 2008 and 2012. The coverage of PCV7 significantly decreased throughout the study period, from 49.3% in period 1 (between June 2008 and April 2009) to 23.4% in period 4 (between October 2011 and March 2012). This change was mainly due to a large decrease in the frequency of 19F (from 20.6% to 9.9%) and 6B (from 10.3% to 2.7%) and an increase in serotype 3 (from 5.1% to 13.5%) and serogroup 15 (from 4.4% to 9.0%). According to serotype replacement, the susceptible ratios of S. pneumoniae to ß-lactams increased slightly while macrolide resistance remained high. The high frequency of macrolide-resistant pneumococcal isolates may continue because of the high frequency of erm(B) in replace serotypes such as serotype 3 and serogroup 15. The continuous surveillance study is essential following the introduction of a second generation 13-valent pneumococcal conjugate vaccine (PCV13).

Novel neogala-series glycosphingolipids with terminal mannose and glucose residues from Hirsutella rhossiliensis, an aureobasidin A-resistant ascomycete fungus.

Hirsutella rhossiliensis, a nematophagous fungus belonging to the Ascomycota, is resistant to aureobasidin A (AbA). In this fungus, the biosynthetic pathway leading to mannosylinositolphosphoceramides, which is inhibited by AbA, was not detected. Instead, this fungus contains neutral complex glycosphingolipids (GSLs) and monoglycosylceramides. Except for monoglycosylceramides, neutral GSLs share a neogala-series core structure, Galbeta1-6Galbeta1-Cer. Among the GSLs of H. rhossiliensis, three novel GSLs with terminal Man and Glc residues on the sugar chain were elucidated. We analyzed GSL structure using compositional sugar, fatty acid, and sphingoid analyses, methylation analysis, matrix-assisted laser desorption ionization time-of-flight/mass spectrometry (MALDI-TOF MS), and (1)H nuclear magnetic resonance spectroscopy (NMR). The following structures were determined: Manalpha1-3Galbeta1-6Galbeta1-6Galbeta1-Cer; Glcalpha1-2Galbeta1-6Galbeta1-6Galbeta1-Cer; and Manalpha1-3Galbeta1-6(Glcalpha1-4)Galbeta1-6Galbeta1-Cer. In the ceramides, the fatty acids were predominantly saturated h24:0-acids and the sphingoids were predominately t18:0- or t18:1-sphingoids. In contrast, the ceramides of Glcbeta1-Cer contained d18:2- and d19:2-sphingoids. These findings indicate the presence of a novel biosynthetic pathway of neogala-series GSLs in fungi.