A multilocus sequence typing (MLST) system was developed for group B streptococcus (GBS). The system was used to characterize a collection (n ‫؍‬ 152) of globally and ecologically diverse human strains of GBS that included representatives of capsular serotypes Ia, Ib, II, III, V, VI, and VIII. Fragments (459 to 519 bp) of seven housekeeping genes were amplified by PCR for each strain and sequenced. The combination of alleles at the seven loci provided an allelic profile or sequence type (ST) for each strain. A subset of the strains were characterized by restriction digest patterning, and these results were highly congruent with those obtained with MLST. There were 29 STs, but 66% of isolates were assigned to four major STs. ST-1 and ST-19 were significantly associated with asymptomatic carriage, whereas ST-23 included both carried and invasive strains. All 44 isolates of ST-17 were serotype III clones, and this ST appeared to define a homogeneous clone that was strongly associated with neonatal invasive infections. The finding that isolates with different capsular serotypes had the same ST suggests that recombination occurs at the capsular locus. A web site for GBS MLST was set up and can be accessed at http://sagalactiae.mlst.net. The GBS MLST system offers investigators a valuable typing tool that will promote further investigation of the population biology of this organism.Streptococcus agalactiae, group B streptococcus (GBS), is an important human pathogen. It is the leading cause of neonatal sepsis in the United Kingdom (18) and the United States (23). It is regarded as an emerging pathogen in the elderly (13) and is a frequent cause of maternal sepsis. However, GBS is usually a commensal organism and can be isolated from the genitourinary and gastrointestinal tracts of up to 35% of healthy adults (1).Capsular serotyping has been one of the mainstays in the descriptive epidemiology of GBS. Nine capsular serotypes have been described (Ia, Ib, and II to VIII). Serotype III GBS strains are of particular importance, as they are responsible for the majority of infections, including meningitis, in neonates worldwide (22). Diverse lineages of serotype III strains can be distinguished with multilocus enzyme electrophoresis (12, 19), pulsed-field gel electrophoresis (20), and restriction digest pattern (RDP) analysis (2), and the lineages appear to vary in pathogenic potential.Multilocus sequence typing (MLST) is an unambiguous sequence-based typing method that involves sequencing approximately 500-bp fragments of seven housekeeping genes and has been used successfully to type strains and investigate the population structure of a number of human bacterial pathogens, including Neisseria meningitidis (16) and Streptococcus pneumoniae (9). MLST is particularly suitable for epidemiological studies because it provides data that can easily be compared between laboratories over the Internet.The primary aim of this study was to develop an MLST system for GBS. Secondary aims were to show that the system could be used on a di...

Phylogenetic relationships among Streptococcus agalactiae isolated from piscine, dolphin, bovine and human sources: a dolphin and piscine lineage associated with a fish epidemic in Kuwait is also associated with human neonatal infections in Japan Streptococcus agalactiae, commonly known as group B streptococcus (GBS), is a cause of infectious disease in numerous animal species. This study examined the genetic relatedness of piscine, dolphin and human GBS isolates and bovine GBS reference strains from different geographical regions using serological and molecular serotyping and multilocus sequence typing (MLST) techniques. Piscine isolates originating from Kuwait, Brazil, Israel and the USA were capsular serotype Ia, a serotype previously unreported in GBS isolated from fish. Sequence typing of piscine isolates produced six sequence types (ST-7, ST-257, ST-258, ST-259, ST-260 and ST-261), the latter five representing allelic designations and allelic combinations not previously reported in the S. agalactiae MLST database. Genomic diversity existed between dolphin and piscine GBS isolates from Kuwait and other geographical areas. Piscine GBS isolates from Brazil, Israel, Honduras and the USA appeared to represent a distinct genetic population of strains that were largely unrelated to human and bovine GBS. The Kuwait dolphin and piscine lineage (ST-7, Ia) was also associated with human neonatal infections in Japan. Comparative genomics of piscine, human and bovine GBS could help clarify those genes important for host tropism, the emergence of unique pathogenic clones and whether these hosts act as reservoirs of one another's pathogenic lineages.

Type III group B streptococci (GBS) isolated from Tokyo and Salt Lake City were classified according to the similarity of HindIII and Sse83871 restriction digest patterns (RDPs) of bacterial DNA. The bacteria were clustered into three RDP types, with excellent correlation between subtyping based on the two enzymes. The majority (91%) of invasive isolates obtained from neonates were RDP type III-3. The mean sialic acid content of the III-3 strains was higher than that of other type III strains. Closely related isolates were concordant for expression of the bacterial enzyme C5a-ase, but invasive strains were no more likely to be C5a-ase positive than were strains isolated from the genitourinary tract of pregnant women. These data indicate that a group of genetically related organisms with increased capsule production causes the majority of invasive type III GBS disease. Group B streptococci (GBS) 3) causes most serotype III neonatal sepsis, suggesting the RDP typing. DNA was extracted from GBS suspended in agarose existence of a genetically related subgroup of serotype III GBS gel plugs (InCert; FMC BioProducts, Rockland, ME) according to that are intrinsically more virulent than other serotype III strains the manufacturer's instructions except that mutanolysin and SDS con- [4]. The purpose of these studies was to determine whether taining proteinase K were used for digestion of the bacteria. DNA in invasive serotype III isolates from Salt Lake City, as well as the agarose gel plugs was digested with HindIII, extracted from the more recently isolated clinical isolates from Japan, are also agarose with phenol, and redigested with HindIII. The DNA sample RDP III-3. We also validated the HindIII typing by typing the was then subjected to electrophoresis in a conventional ethidium bromide-agarose gel. The similarity between densitometric RDPs from individual strains was expressed as a Pearson product moment correlation coefficient (PPMCC) and clustered by the unweighted

Advanced gastric cancer is often accompanied by metastasis to the peritoneum, resulting in a high mortality rate. Mechanisms involved in gastric cancer metastasis have not been fully clarified because metastasis involves multiple steps and requires a combination of altered expressions of many different genes. Thus, independent analysis of any single gene would be insufficient to understand all of the aspects of gastric cancer peritoneal dissemination. In this study, we performed a global analysis of the differential gene expression of a gastric cancer cell line established from a primary main tumour (SNU-1) and of other cell lines established from the metastasis to the peritoneal cavity (SNU-5, SNU-16, SNU-620, KATO-III and GT3TKB). The application of a high-density cDNA microarray method made it possible to analyse the expression of approximately 21 168 genes. Our examinations of SNU-5, SNU-16, SNU-620, KATO-III and GT3TKB showed that 24 genes were upregulated and 17 genes down-regulated besides expression sequence tags. The analysis revealed the following altered expression such as: (a) up-regulation of CD44 (cell adhesion), keratins 7, 8, and 14 (epitherial marker), aldehyde dehydrogenase (drug metabolism), CD9 and IP3 receptor type3 (signal transduction); (b) down-regulation of IL2 receptor g, IL4-Stat (immune response), p27 (cell cycle) and integrin b4 (adhesion) in gastric cancer cells from malignant ascites. We then analysed eight gastric cancer cell lines with Northern blot and observed preferential up-regulation and down-regulation of these selected genes in cells prone to peritoneal dissemination. Reverse transcriptase -polymerase chain reaction confirmed that several genes selected by DNA microarray were also overexpressed in clinical samples of malignant ascites. It is therefore considered that these genes may be related to the peritoneal dissemination of gastric cancers. The results of this global gene expression analysis of gastric cancer cells with peritoneal dissemination, promise to provide a new insight into the study of human gastric cancer peritoneal dissemination.

This study compares the phylogenetic lineages of invasive serotype III group B streptococci (GBS) to those of colonizing strains in order to determine lineages associated with invasive disease. Isolates from 29 infants with early-onset disease (EOD) and from 196 colonized infants, collected in a prospective, multicenter study, were assigned a sequence type (ST) by multilocus sequence typing. Overall, 54.5% of the isolates were in the ST-19 complex, and 40.4% were in the ST-17 complex. Invasive strains were more likely to be in the ST-17 complex than were colonizing strains (59% versus 38%, P ‫؍‬ 0.03). After we adjusted for potential confounders, the ST-17 complex was more likely to be associated with EOD than were other lineages (odds ratio ‫؍‬ 2.51, 95% confidence interval ‫؍‬ 1.02 to 6.20). These data support the hypothesis that ST-17 complex GBS are more virulent than other serotype III GBS.

The Japanese quail has several advantages as a laboratory animal for biological and biomedical investigations. In this study, the draft genome of the Japanese quail was sequenced and assembled using next-generation sequencing technology. To improve the quality of the assembly, the sequence reads from the Japanese quail were aligned against the reference genome of the chicken. The final draft assembly consisted of 1.75 Gbp with an N50 contig length of 11,409 bp. On the basis of the draft genome sequence obtained, we developed 100 microsatellite markers and used these markers to evaluate the genetic variability and diversity of 11 lines of Japanese quail. Furthermore, we identified Japanese quail orthologs of spermatogenesis markers and analyzed their expression using in situ hybridization. The Japanese quail genome sequence obtained in the present study could enhance the value of this species as a model animal.

Wall teichoic acid (WTA) of Staphylococcus aureus is a major cell envelope-associated glycopolymer that is a key molecule in promoting colonization during S. aureus infection. The complement system plays a key role in the opsonization and clearance of pathogens. We recently reported that S. aureus WTA functions as a ligand of human serum mannose-binding lectin (MBL), a recognition molecule of the lectin complement pathway. Intriguingly, serum MBL in adults does not bind to WTA because of an inhibitory effect of serum anti–WTA-IgG. In this study, serum anti–WTA-IgG was purified to homogeneity using a purified S. aureus WTA-coupled affinity column to examine the biological function of human anti–WTA-IgG. The purified anti–WTA-IgG contained the IgG2 subclass as a major component and specifically induced C4 and C3 deposition on the S. aureus surface in the anti–WTA-IgG–depleted serum, but not in C1q-deficient serum. Furthermore, the anti–WTA-IgG–dependent C3 deposition induced phagocytosis of S. aureus cells by human polymorphonuclear leukocytes. These results demonstrate that serum anti–WTA-IgG is a real trigger for the induction of classical complement-dependent opsonophagocytosis against S. aureus. Our results also support the fact that a lack of the lectin complement pathway in MBL-deficient adults is compensated by Ag-specific, Ab-mediated adaptive immunity.

The G protein-coupled receptor (GPCR) family is highly diversified and involved in many forms of information processing. SREB2 (GPR85) is the most conserved GPCR throughout vertebrate evolution and is expressed abundantly in brain structures exhibiting high levels of plasticity, e.g., the hippocampal dentate gyrus. Here, we show that SREB2 is involved in determining brain size, modulating diverse behaviors, and potentially in vulnerability to schizophrenia. Mild overexpression of SREB2 caused significant brain weight reduction and ventricular enlargement in transgenic (Tg) mice as well as behavioral abnormalities mirroring psychiatric disorders, e.g., decreased social interaction, abnormal sensorimotor gating, and impaired memory. SREB2 KO mice showed a reciprocal phenotype, a significant increase in brain weight accompanying a trend toward enhanced memory without apparent other behavioral abnormalities. In both Tg and KO mice, no gross malformation of brain structures was observed. Because of phenotypic overlap between SREB2 Tg mice and schizophrenia, we sought a possible link between the two. Minor alleles of two SREB2 SNPs, located in intron 2 and in the 3 UTR, were overtransmitted to schizophrenia patients in a family-based sample and showed an allele load association with reduced hippocampal gray matter volume in patients. Our data implicate SREB2 as a potential risk factor for psychiatric disorders and its pathway as a target for psychiatric therapy.gene manipulation ͉ memory ͉ SNPs T he SREB (superconserved receptor expressed in brain) family of SREB1 (GPR27), SREB2 (GPR85), and SREB3 (GPR173) is a unique subfamily of G protein-coupled receptor (GPCR) selectively expressed in neurons (1-5). Intriguing features of the SREB family include its high degree of sequence conservation throughout vertebrate evolution and its abundant expression in brain structures showing high levels of plasticity, for example the hippocampal dentate gyrus. Among these three members, SREB2 is the most conserved-the primary amino acid sequence is 100% identical among humans, rats, and mice. SREB1 and SREB3 are also highly conserved in mammals. Despite the extraordinary conservation rate in vertebrates, SREB orthologues are not encoded in the genome sequence of Caenorhabditis elegans or Drosophila melanogaster (3).The history of drug discovery has proven that GPCRs are excellent therapeutic targets (6, 7). Although efforts have been made to identify endogenous ligand(s) for SREB, they have been unsuccessful (3). Recent progress in understanding of GPCR physiology has, however, enabled screening of drug candidates for promising GPCRs without knowledge of their endogenous ligands, e.g., screening compounds by using constitutively active mutants (8) or ligand-induced conformational change (9). Thus, if their physiological function is clarified, and their link to the pathophysiology of diseases is demonstrated, then newly discovered GPCRs, even orphan GPCRs like SREB2, become promising drug targets. The distinct features of SREB2, namel...