Publications by authors named "Toshiro Kuroki"

37 Publications

Detection and molecular characteristics of Rhytidodoides sp. (Digenea: Rhytidodidae) from the gall bladder of green sea turtles (Chelonia mydas) in the Ogasawara Islands, Japan.

Parasitol Int 2021 May 7:102377. Epub 2021 May 7.

Laboratory of Parasitology, Faculty of Veterinary medicine, Okayama University of Science, 1-3 Ikoinooka, Imabari 794-8555, Japan.

Trematodes of the genus Rhytidodoides are parasitic in marine turtles. Of the already known species, Rhytidodoides similis Price, 1939, occurs especially in the gall bladder. In this study, we surveyed 73 green sea turtles (Chelonia mydas) in the Ogasawara Islands, Japan, and detected Rhytidodoides sp. from the gall bladders of 18 turtles. A detailed morphological analysis revealed that the forebody of Rhytidodoides sp. differed slightly in shape from that of R. similis. There has been no information on DNA sequences of the family Rhytidodidae. A molecular phylogeny based on 28S rDNA sequences of Rhytidodoides sp. and related taxa suggested that the Rhytidodidae is sister to the other families of Echinostomatoidea. The intraspecific diversity of Rhytidodoides sp. was examined by using DNA sequences of mitochondrial cytochrome c oxidase subunit 1 gene (COI). The population genetic features of the COI haplotypes demonstrated that Rhytidodoides sp. is highly diverse in the Ogasawara Islands. The DNA sequences determined in this study will contribute to the species identification of congeners and the taxonomic reconsideration of the Echinostomatoidea.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.parint.2021.102377DOI Listing
May 2021

Emergence and evolution of antimicrobial resistance genes and mutations in Neisseria gonorrhoeae.

Genome Med 2021 Mar 30;13(1):51. Epub 2021 Mar 30.

Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.

Background: Antimicrobial resistance in Neisseria gonorrhoeae is a global health concern. Strains from two internationally circulating sequence types, ST-7363 and ST-1901, have acquired resistance to third-generation cephalosporins, mainly due to mosaic penA alleles. These two STs were first detected in Japan; however, the timeline, mechanism, and process of emergence and spread of these mosaic penA alleles to other countries remain unknown.

Methods: We studied the evolution of penA alleles by obtaining the complete genomes from three Japanese ST-1901 clinical isolates harboring mosaic penA allele 34 (penA-34) dating from 2005 and generating a phylogenetic representation of 1075 strains sampled from 35 countries. We also sequenced the genomes of 103 Japanese ST-7363 N. gonorrhoeae isolates from 1996 to 2005 and reconstructed a phylogeny including 88 previously sequenced genomes.

Results: Based on an estimate of the time-of-emergence of ST-1901 (harboring mosaic penA-34) and ST-7363 (harboring mosaic penA-10), and > 300 additional genome sequences of Japanese strains representing multiple STs isolated in 1996-2015, we suggest that penA-34 in ST-1901 was generated from penA-10 via recombination with another Neisseria species, followed by recombination with a gonococcal strain harboring wildtype penA-1. Following the acquisition of penA-10 in ST-7363, a dominant sub-lineage rapidly acquired fluoroquinolone resistance mutations at GyrA 95 and ParC 87-88, by independent mutations rather than horizontal gene transfer. Data in the literature suggest that the emergence of these resistance determinants may reflect selection from the standard treatment regimens in Japan at that time.

Conclusions: Our findings highlight how antibiotic use and recombination across and within Neisseria species intersect in driving the emergence and spread of drug-resistant gonorrhea.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13073-021-00860-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8008663PMC
March 2021

Infection by and Molecular Features of (Digenea: Schistosomatoidea) in Green Sea Turtles () on the Ogasawara Islands, Japan.

J Parasitol 2019 08;105(4):533-538

3   Laboratory of Veterinary Parasitology, Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka 020-8550, Japan.

Price, 1934 , is a blood fluke found in sea turtles, and the adult fluke parasitizes the cardiovascular system of the host. In this study we surveyed 46 green sea turtles, , on the Ogasawara Islands, Japan, and blood flukes were detected in the heart and blood vessels of 26 turtles. The flukes were identified as based on a detailed morphological description. In addition, molecular identification and characterization of the parasite were performed. The nucleotide sequences of nuclear internal transcribed spacer 2 () regions were almost identical to those of reported previously, but not to those of spp., which is the closest related genus. The nucleotide sequences of the ribosomal DNA region formed a single clade with those of the reference in the phylogenetic tree, but not with those of spp. Therefore, the nucleotide sequences of and are robust markers for distinguishing from other species. The nucleotide sequences of the mitochondrial cytochrome oxidase subunit 1 () region were analyzed to evaluate the genetic variations in . The haplotypes revealed the extremely high genetic diversity of the species as well as the host turtles on the Ogasawara Islands. The haplotype frequency in the mitochondrial DNA of the green sea turtles on the Ogasawara Islands is known to be significantly different from those in other Pacific rookeries. Although the number of analyzed flukes is small in this study, no haplotype was close to that in other areas; on the basis of the data, we hypothesized that differentiated along with the host turtles on the Ogasawara Islands.
View Article and Find Full Text PDF

Download full-text PDF

Source
August 2019

Prevalence of Salmonella enterica Subspecies enterica in Red-Eared Sliders Trachemys scripta elegans Retailed in Pet Shops in Japan.

Jpn J Infect Dis 2019 Jan 28;72(1):38-43. Epub 2018 Sep 28.

Department of Pathology, School of Veterinary Medicine, Azabu University.

We investigated the prevalence of Salmonella in 227 small red-eared sliders (Trachemys scripta elegans) from 2006 to 2008. A total of 130 turtles (57.3%) tested positive for S. enterica subsp. enterica. Twenty-two serotypes including S. Montevideo, S. Newport, S. Pomona, S. Braenderup, S. Sandiego, and S. Litchfield were identified. Salmonella strains with closely related pulsed field gel electrophoresis (PFGE) patterns were isolated from several shops located in different areas from 2006 to 2008. Antimicrobial resistance was detected among strains of S. Montevideo, S. Newport, S. Braenderup, S. Sandiego, and S. Litchfield. The relatedness of antimicrobial resistance and PFGE profiles was not observed. The PFGE patterns of S. Poona strains isolated in 2006 and 2008 and the causative strains of turtle-associated salmonellosis in 2006 were identical. These results revealed a high prevalence of Salmonella enterica subsp. enterica in red-eared sliders retailed in Japan. In addition, genetically closely-related strains of turtle-associated Salmonella were repeatedly introduced into Japan over the study period and were distributed widely in Japan. These Salmonella strains present a risk of a widely disseminated outbreak of turtle-associated salmonellosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7883/yoken.JJID.2018.140DOI Listing
January 2019

Outbreak of Enterohemorrhagic Escherichia coli O157:H7 Infection Associated with Minced Meat Cutlets Consumption in Kanagawa, Japan.

Jpn J Infect Dis 2018 Nov 31;71(6):436-441. Epub 2018 Jul 31.

Department of Microbiology, Kanagawa Prefectural Institute of Public Health.

An outbreak of enterohemorrhagic Escherichia coli (EHEC) O157:H7 infection occurred in October 2016 in Kanagawa, Japan. A total of 61 patients and 17 asymptomatic cases of EHEC O157:H7 infection were confirmed by laboratory testing. Among them, 24 patients were hospitalized and 4 developed hemolytic-uremic syndrome. An epidemiological investigation revealed that this outbreak of EHEC O157:H7 infection was associated with the consumption of uncooked minced meat cutlets that were sold frozen at branches of a supermarket chain. The implicated uncooked meat cutlets were made of a mixture of minced beef, pork, onions, and eggs. All 40 meat cutlets tested from one particular batch were positive for EHEC O157:H7. The patterns observed on pulsed-field gel electrophoresis of strains isolated from the affected patients and meat cutlets were identical. The bacterial counts of EHEC O157:H7 and E. coli in meat cutlets ranged from 2.3 to 110 most-probable-number (MPN)/g and from 240 to 4,600 MPN/g, respectively. There are currently no national regulatory standards to ensure the safety of these types of meat products in Japan. Consumers should ensure that such products are cooked thoroughly and that safe food handling procedures are used to prevent infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7883/yoken.JJID.2017.495DOI Listing
November 2018

Genomic surveillance of Neisseria gonorrhoeae to investigate the distribution and evolution of antimicrobial-resistance determinants and lineages.

Microb Genom 2018 08 31;4(8). Epub 2018 Jul 31.

2​Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.

The first extensively drug resistant (XDR) Neisseria gonorrhoeae strain with high resistance to the extended-spectrum cephalosporin ceftriaxone was identified in 2009 in Japan, but no other strain with this antimicrobial-resistance profile has been reported since. However, surveillance to date has been based on phenotypic methods and sequence typing, not genome sequencing. Therefore, little is known about the local population structure at the genomic level, and how resistance determinants and lineages are distributed and evolve. We analysed the whole-genome sequence data and the antimicrobial-susceptibility testing results of 204 strains sampled in a region where the first XDR ceftriaxone-resistant N. gonorrhoeae was isolated, complemented with 67 additional genomes from other time frames and locations within Japan. Strains resistant to ceftriaxone were not found, but we discovered a sequence type (ST)7363 sub-lineage susceptible to ceftriaxone and cefixime in which the mosaic penA allele responsible for reduced susceptibility had reverted to a susceptible allele by recombination. Approximately 85 % of isolates showed resistance to fluoroquinolones (ciprofloxacin) explained by linked amino acid substitutions at positions 91 and 95 of GyrA with 99 % sensitivity and 100 % specificity. Approximately 10 % showed resistance to macrolides (azithromycin), for which genetic determinants are less clear. Furthermore, we revealed different evolutionary paths of the two major lineages: single acquisition of penA X in the ST7363-associated lineage, followed by multiple independent acquisitions of the penA X and XXXIV in the ST1901-associated lineage. Our study provides a detailed picture of the distribution of resistance determinants and disentangles the evolution of the two major lineages spreading worldwide.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1099/mgen.0.000205DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6159555PMC
August 2018

Characterization of Shiga toxin-producing Escherichia coli from feces of sika deer (Cervus nippon) in Japan using PCR binary typing analysis to evaluate their potential human pathogenicity.

J Vet Med Sci 2017 May 18;79(5):834-841. Epub 2017 Mar 18.

Laboratory of Veterinary Public Health, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa-shi, Kanagawa 252-0880, Japan.

This study examined the potential pathogenicity of Shiga toxin-producing Escherichia coli (STEC) in feces of sika deer by PCR binary typing (P-BIT), using 24 selected STEC genes. A total of 31 STEC strains derived from sika deer in 6 prefectures of Japan were O-serotyped and found to be O93 (n=12), O146 (n=5), O176 (n=3), O130 (n=3), O5 (n=2), O7 (n=1), O96 (n=1), O116 (n=1), O141 (n=1), O157 (n=1) and O-untypable (n=1). Of the 31 STEC strains, 13 carried both stx1 and stx2, 5 carried only stx1, and 13 carried one or two variants of stx2. However, no Stx2 production was observed in 3 strains that carried only stx2: the other 28 strains produced the appropriate Stx. P-BIT analysis showed that the 5 O5 strains from two wild deer formed a cluster with human STEC strains, suggesting that the profiles of the presence of the 24 P-BIT genes in the deer strains were significantly similar to those in human strains. All of the other non-O157 STEC strains in this study were classified with strains from food, domestic animals and humans in another cluster. Good sanitary conditions should be used for deer meat processing to avoid STEC contamination, because STEC is prevalent in deer and deer may be a potential source of STEC causing human infections.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.16-0568DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5447969PMC
May 2017

Outbreak of Legionnaire's Disease Caused by Legionella pneumophila Serogroups 1 and 13.

Emerg Infect Dis 2017 02;23(2):349-351

In Japan, hot springs and public baths are the major sources of legionellosis. In 2015, an outbreak of Legionnaires' disease occurred among 7 patients who had visited a spa house. Laboratory investigation indicated that L. pneumophila serogroup 1 and 13 strains caused the outbreak and that these strains were genetically related.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3201/eid2302.161012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5324795PMC
February 2017

Prevalence and Characteristics of Salmonella and Campylobacter in Retail Poultry Meat in Japan.

Jpn J Infect Dis 2017 May 31;70(3):239-247. Epub 2016 Aug 31.

Department of Microbiology, Kanagawa Prefectural Institute of Public Health.

This study was performed to determine the prevalence, antimicrobial susceptibility, and genetic relatedness of Salmonella enterica subsp. enterica and Campylobacter spp. in poultry meat, and to analyze the association of genetic types of these bacteria with their geographical distribution and antimicrobial resistance profiles. Salmonella and Campylobacter isolates have been detected, respectively, in 54 and 71 samples out of 100 samples tested. Nine Salmonella serotypes were found, including S. enterica subsp. enterica serovar Infantis (33%), Schwarzengrund (12%), Manhattan (9%), and others. Campylobacter jejuni and C. coli were detected in 64 (64%) and 14 (14%) samples, respectively. S. enterica subsp. enterica isolates were very frequently resistant to tetracycline (78.3%) and streptomycin (68.3%). Many C. jejuni and C. coli isolates were resistant to sulfamethoxazole/trimethoprim (90.5%), nalidixic acid (47.3%), ampicillin (45.9%), and ciprofloxacin (40.5%). Cluster analysis was performed for the Salmonella isolates using pulsed-field gel electrophoresis (PFGE) data. For Campylobacter isolates, the cluster analysis was based on both PFGE and comparative genomic fingerprinting. The molecular typing results were compared with the information about antimicrobial resistance and geographical locations in which the poultry meat was produced. This analysis revealed that C. jejuni strains with a particular genotype and antimicrobial resistance profile are spreading in specific areas of Japan.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7883/yoken.JJID.2016.164DOI Listing
May 2017

[Molecular Characterization of Salmonella enterica subsp. enterica Serovar 4: b: -].

Kansenshogaku Zasshi 2016 Sep;90(5):652-6

Salmonella is a major causative agent of food borne diseases. Recently, monophasic strains of Salmonella, such as S. enterica 4: i: -, have been frequently reported. Here, we investigated the genetic background of S. enterica 4: b: - using multilocus sequence typing (MLST) and pulsed-field gel electrophoresis. A total of 10 strains of S. enterica (I) 4: b: - were examined and compared with 34 strains including serovar Paratyphi B and Paratyphi B var Java, Schleissheim, and II b: -. All I 4: b: - strains were negative for hin which encodes an invertase that converts the H phases, and six were also negative for fljB, which encodes the second phase of the H antigen. An MLST analysis identified 12 sequence types (ST) and 6 ST complexes (STC) from the 44 strains. A clustering analysis of PFGE patterns almost corresponded to the STC. The monophasic I 4: b: - strains were assigned to 3 STCs (19, 32 and 155), corresponding to those of Paratyphi B var. Java or a monophasic strain according to the data of this and previous studies. These findings suggest that the monophasic strains examined in this study might have been derived from multiple clones of Paratyphi B var Java. This study shows the usefulness of molecular typing as complementation tools of the conventional serotyping system.
View Article and Find Full Text PDF

Download full-text PDF

Source
September 2016

Emergence and evolution of internationally disseminated cephalosporin-resistant Neisseria gonorrhoeae clones from 1995 to 2005 in Japan.

BMC Infect Dis 2015 Sep 17;15:378. Epub 2015 Sep 17.

National Institute of Infectious Diseases, Tokyo, Japan.

Background: Neisseria gonorrhoeae strains with resistance to extended-spectrum cephalosporins (ESCs), last options for first-line monotherapy of gonorrhoea, likely emerged and initially disseminated in Japan, followed by international transmission. In recent years, multi-locus sequence typing (MLST) ST1901 and N. gonorrhoeae multiantigen sequence typing (NG-MAST) ST1407 isolates with the mosaic penicillin-binding protein (PBP) 2 XXXIV have accounted for most ESC resistance globally. Our aim was to elucidate the initial emergence and transmission of ESC-resistant strains by detailed examination of N. gonorrhoeae isolates from 1995 to 2005 in Kanagawa, Japan.

Methods: N. gonorrhoeae isolates were examined phenotypically (n = 690) and genetically (n = 372) by agar dilution method (cefixime, ceftriaxone and ciprofloxacin), penA gene sequencing, MLST and NG-MAST.

Results: Already in 1995, one cefixime-resistant (CFM-R) isolate was found, which is the first CFM-R isolate described globally. After 1996, the prevalence of CFM-R and CFM-decreased susceptibility (CFM-DS) isolates significantly increased, with the peak resistance level in 2002 (57.1% CFM-R). In 1997-2002, the CFM-R MLST ST7363 strain type with the mosaic PBP 2 X was predominant among CFM-R/DS isolates. The first CFM-R/DS MLST ST1901 clone(s), which became the predominant CFM-R/DS strain type(s) already in 2003-2005, possessed the mosaic PBP 2 X, which was possibly originally transferred from the MLST ST7363 strains, and subsequently acquired the mosaic PBP 2 XXXIV. The first MLST ST1901 and NG-MAST ST1407 isolate was identified in Kanagawa already in 2003.

Conclusions: The two main internationally spread cefixime-resistant gonococcal clones, MLST ST7363 and ST1901 (NG-MAST ST1407 most frequent internationally) that also have shown their capacity to develop high-level ceftriaxone resistance (superbugs H041 and F89), likely emerged, evolved and started to disseminate in the metropolitan area, including Kanagawa, in Japan, which was followed by global transmission.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12879-015-1110-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4574456PMC
September 2015

Turtle-Associated Salmonella Infections in Kanagawa, Japan.

Jpn J Infect Dis 2015 13;68(4):333-7. Epub 2015 Mar 13.

Department of Microbiology, Kanagawa Prefectural Institute of Public Health.

In this paper, we examine 2 case reports for different reptile-related Salmonella enterica subspecies enterica serotypes. In case 1, a 5-year-old boy presented with gastroenteritis caused by S. enterica subspecies enterica serovar Poona. The suspected source of infection was a turtle kept at the patient's home. In case 2, a 4-year-old boy presented with gastroenteritis caused by S. enterica subspecies enterica serovar Abony. The Pulsed-field gel electrophoresis analysis suggested that a tortoise kept at the patient's home was the source of infection. This paper presents a review of the literature and an examination of cases regarding turtle-associated salmonellosis in Japan.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7883/yoken.JJID.2014.490DOI Listing
May 2016

Phylogenetic Clades 6 and 8 of Enterohemorrhagic Escherichia coli O157:H7 With Particular stx Subtypes are More Frequently Found in Isolates From Hemolytic Uremic Syndrome Patients Than From Asymptomatic Carriers.

Open Forum Infect Dis 2014 Sep 12;1(2):ofu061. Epub 2014 Aug 12.

Department of Bacteriology I , National Institute of Infectious Diseases , Tokyo , Japan.

Background: Enterohemorrhagic Escherichia coli (EHEC) O157:H7 infection causes severe diseases such as bloody diarrhea and hemolytic uremic syndrome (HUS). Although EHEC O157:H7 strains have exhibited high genetic variability, their abilities to cause human diseases have not been fully examined.

Methods: Clade typing and stx subtyping of EHEC O157:H7 strains, which were isolated in Japan during 1999-2011 from 269 HUS patients and 387 asymptomatic carriers (ACs) and showed distinct pulsed-field gel electrophoresis patterns, were performed to determine relationships between specific lineages and clinical presentation.

Results: Clades 6 and 8 strains were more frequently found among the isolates from HUS cases than those from ACs (P = .00062 for clade 6, P < .0001 for clade 8). All clade 6 strains isolated from HUS patients harbored stx2a and/or stx2c, whereas all clade 8 strains harbored either stx2a or stx2a/stx2c. However, clade 7 strains were predominantly found among the AC isolates but less frequently found among the HUS isolates, suggesting a significant association between clade 7 and AC (P < .0001). Logistic regression analysis revealed that 0-9 year old age is a significant predictor of the association between clade 8 and HUS. We also found an intact norV gene, which encodes for a nitric oxide reductase that inhibits Shiga toxin activity under anaerobic condition, in all clades 1-3 isolates but not in clades 4-8 isolates.

Conclusions: Early detection of EHEC O157:H7 strains that belonged to clades 6/8 and harbored specific stx subtypes may be important for defining the risk of disease progression in EHEC-infected 0- to 9-year-old children.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ofid/ofu061DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4281788PMC
September 2014

Prevalence of Salmonella in wild snakes in Japan.

Jpn J Infect Dis 2013 ;66(4):295-8

Department of Microbiology, Kanagawa Prefectural Institute of Public Health, Kanagawa, Japan.

A total of 87 wild snakes of 6 species in 2 families collected in Japan were examined for the presence of Salmonella. The prevalence of Salmonella was 58.6%, and that of Salmonella enterica subspecies I, which includes most human pathogenic serotypes, accounted for 12.6%. S. enterica subspecies I was isolated from Japanese grass snakes and Japanese four-striped snakes, and the isolates belonged to 6 serotypes: S. enterica subspecies enterica serotypes Eastbourne, Mikawashima, Narashino, Newport, Saintpaul, and Thompson. The prevalence of S. enterica subspecies IIIb was higher (41.4%) than that of S. enterica subspecies I, and it was isolated from 4 snake species. The prevalence of Salmonella enterica subspecies and isolation of serotypes that are commonly detected in reptiles and human salmonellosis suggest that wild snakes may become a source of Salmonella infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7883/yoken.66.295DOI Listing
February 2014

Multi-locus sequence typing of Salmonella enterica subsp. enterica serovar Enteritidis strains in Japan between 1973 and 2004.

Acta Vet Scand 2011 Jun 15;53:38. Epub 2011 Jun 15.

Division of Pathology and Bacteriology, Fukuoka Institute of Health and Environmental Sciences, 39 Mukaizano, Dazaifu, Fukuoka 818-0135, Japan.

Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) was responsible for a worldwide pandemic during the 1980s and 1990s; however, changes in the dominant lineage before and after this event remain unknown. This study determined S. Enteritidis lineages before and after this pandemic event in Japan using multilocus sequence typing (MLST). Thirty S. Enteritidis strains were collected in Japan between 1973 and 2004, consisting of 27 human strains from individual episodes, a bovine strain, a liquid egg strain and an eggshell strain. Strains showed nine phage types and 17 pulsed-field profiles with pulsed-field gel electrophoresis. All strains had homologous type 11 sequences without any nucleotide differences in seven housekeeping genes. These MLST results suggest that S. Enteritidis with the diversities revealed by phage typing and pulsed-field profiling has a highly clonal population. Although type 11 S. Enteritidis may exhibit both pleiotropic surface structure and pulsed-field type variation, it is likely to be a stable lineage derived from an ancestor before the 1980s and/or 1990s pandemic in Japan.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/1751-0147-53-38DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3126718PMC
June 2011

[Neisseria gonorrhoeae].

Nihon Rinsho 2010 Jun;68 Suppl 6:172-5

National Institute of Infectious Diseases.

View Article and Find Full Text PDF

Download full-text PDF

Source
June 2010

Spread of a chromosomal cefixime-resistant penA gene among different Neisseria gonorrhoeae lineages.

Antimicrob Agents Chemother 2010 Mar 22;54(3):1060-7. Epub 2009 Dec 22.

Department of Bacteriology, National Institute of Infectious Diseases, 1-23-1, Toyama, Shinjuku, Tokyo 162-8640, Japan.

In Neisseria gonorrhoeae, the mosaic type of penA, which encodes penicillin-binding protein 2 (PBP 2), is associated with reduced susceptibility to oral cephalosporins. To investigate the relatedness of N. gonorrhoeae clinical isolates with reduced susceptibility, we sequenced the penA genes of 32 isolates. Five different amino acid sequence types of PBP 2 were identified, but all seemed to be derivatives of pattern X of PBP 2 (PBP 2-X). However, multilocus sequence typing of the isolates showed that the isolates belonged to six different sequence types. As PBP 2-X was identified in three different sequence types, horizontal transfer of the penA allele encoding PBP2-X was suggested. We demonstrated that the penA gene could be transferred from an isolate with reduced susceptibility to a sensitive isolate by natural transformation. Comparison of the sequence of the penA-flanking regions of 12 transformants with those of the donor and the recipient suggested that at least a 4-kb DNA segment, including the penA gene, was transferred. During horizontal transfer, some of the penA alleles also acquired variations due to point mutations and genetic exchange within the allele. Our results provide evidence that the capacity for natural transformation in N. gonorrhoeae plays a role in the spread of chromosomal antibiotic resistance genes and the generation of diversity in such genes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/AAC.01010-09DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2826007PMC
March 2010

Amphibian chytridiomycosis in Japan: distribution, haplotypes and possible route of entry into Japan.

Mol Ecol 2009 Dec 13;18(23):4757-74. Epub 2009 Oct 13.

National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.

A serious disease of amphibians caused by the chytrid fungus Batrachochytrium dendrobatidis was first found in Japan in December 2006 in imported pet frogs. This was the first report of chytridiomycosis in Asia. To assess the risk of pandemic chytridiomycosis to Japanese frogs, we surveyed the distribution of the fungus among captive and wild frog populations. We established a nested PCR assay that uses two pairs of PCR primers to amplify the internal transcribed spacer (ITS) region of a ribosomal RNA cassette to detect mild fungal infections from as little as 0.001 pg (1 fg) of B. dendrobatidis DNA. We collected swab samples from 265 amphibians sold at pet shops, 294 bred at institutes and 2103 collected at field sites from northern to southwestern Japan. We detected infections in native and exotic species, both in captivity and in the field. Sequencing of PCR products revealed 26 haplotypes of the B. dendrobatidis ITS region. Phylogenetic analysis showed that three of these haplotypes were specific to the Japanese giant salamander (Andrias japonicus) and appeared to have established a commensal relationship with this native amphibian. Many other haplotypes were carried by alien amphibians. The highest genetic diversity of B. dendrobatidis was found in the American bullfrog (Rana catesbeiana). Some strains of B. dendrobatidis appeared to be endemic to Japanese native amphibians, but many alien strains are being introduced into Japan via imported amphibians. To improve chytridiomycosis risk management, we must consider the risk of B. dendrobatidis changing hosts as a result of anthropogenic disturbance of the host-specific distribution of the fungus.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1365-294X.2009.04384.xDOI Listing
December 2009

Bathwater-associated cases of legionellosis in Japan, with a special focus on Legionella concentrations in water.

Jpn J Infect Dis 2009 May;62(3):201-5

Department of Microbiology, Kanagawa Prefectural Institute of Public Health, Kanagawa 253-0087, Japan.

To evaluate the relationship between the incidence of legionellosis and Legionella concentrations in bathwater, we sent a questionnaire to 76 prefectural and municipal public health laboratories in Japan and found that 35 had encountered cases of legionellosis and had implemented investigations to determine the sources of the infections. Based on the results of the questionnaire, we were able to analyze various characteristics of the patients, of the facilities that were thought to be associated with the cases, and of the species and serogroups of the isolates and concentrations of Legionella. Ninety-six cases were included in this study. The median age was 67 years (range, 13-89 years). The most prevalent underlying medical condition among patients was diabetes, and the second most prevalent was high blood pressure. Concentrations of Legionella in bathwater ranged from 10 to 160,000 CFU/100 ml. Ten episodes were selected in which causative strains were found in the suspected source environment, and were then confirmed by pulsed-field gel electrophoresis analysis, enabling us to provide an estimated infectious concentration range of Legionella of 90 to 140,000 CFU/100 ml. It was thus suggested that the current Japanese regulatory safety level for Legionella in bathwater, which is set below the detection limit of culture techniques (10 CFU/100 ml), should be appropriate to prevent bathwater-associated legionellosis. In tandem with the above-mentioned research, a review of literature concerning bathwater-associated legionellosis and typical cases was undertaken.
View Article and Find Full Text PDF

Download full-text PDF

Source
May 2009

Isolation and characterization of Leptospira spp. from raccoons in Japan.

J Vet Med Sci 2009 Apr;71(4):425-9

Department of Bacteriology, National Institute of Infectious Diseases.

We investigated whether raccoons (Procyon lotor) carried leptospires in their kidneys in Japan. Leptospira was isolated from 2 of 71 raccoons captured in Kanagawa Prefecture and 1 of 53 raccoons at a zoological park in Nagasaki Prefecture. Anti-Leptospira antibodies were detected in 16 of 124 raccoons (12.9%) in Kanagawa and 33 of 53 raccoons (62.3%) in Nagasaki, respectively. The partial nucleotide sequences of their flaB genes suggested that the isolates belonged to L. interrogans. The serovars of the isolates were identified as Copenhageni/Icterohaemorrhagiae (1 strain in Kanagawa) and Hebdomadis (1 strain both in Kanagawa and Nagasaki) by reactivity with the reference antisera and restriction fragment length polymorphism (RFLP) analysis based on pulsed-field gel electrophoresis and cross-agglutination-absorption test, respectively. RFLP analysis on the serovars Hebdomadis strains revealed genetic diversity among serovar Hebdomadis. Although it is unclear if the raccoons carried leptospires in their kidneys at the time imported, there is no doubt that imported animals are a new reservoir animal of leptospires in Japan.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.71.425DOI Listing
April 2009

[Legionella contamination risk factors in non-circulating hot spring water].

Kansenshogaku Zasshi 2009 Jan;83(1):36-44

Ehime Prefectural Institute of Public Health and Environmental Science.

We examined water from 182 non-circulating hot spring bathing facilities in Japan for possible Legionella occurrence from June 2005 to December 2006, finding Legionella-positive cultures in 119 (29.5%) of 403 samples. Legionellae occurrence was most prevalent in bathtub water (39.4%), followed by storage tank water (23.8%), water from faucets at the bathtub edge (22.3%), and source-spring water (8.3%), indicating no statistically significant difference, in the number of legionellae, having an overall mean of 66 CFU/100mL. The maximum number of legionellae in water increased as water was sampled downstream:180 CFU/100 mL from source spring, 670 from storage tanks, 4,000 from inlet faucets, and 6,800 from bathtubs. The majority--85.7%--of isolated species were identified as L. pneumophila : L. pneumophila serogroup (SG) 1 in 22%, SG 5 in 21%, and SG 6 in 22% of positive samples. Multivariate logistic regression models used to determine the characteristics of facilities and sanitary management associated with Legionella contamination indicated that legionellae was prevalent in bathtub water under conditions where it was isolated from inlet faucet/pouring gate water (odds ratio [OR] = 6.98, 95% confidence interval [CI] = 2.14 to 22.8). Risk of occurrence was also high when the bathtub volume exceeded 5 m3 (OR = 2.74, 95% CI = 1.28 to 5.89). Legionellae occurrence was significantly reduced when the bathing water pH was lower than 6.0 (OR = 0.12, 95% CI = 0.02 to 0.63). Similarly, occurrence was rare in inlet faucet water or the upper part of the plumbing system for which pH was lower than 6.0 (OR = 0.06, 95% CI = 0.01 to 0.48), and when the water temperature was maintained at 55 degrees C or more (OR = 0.10, 95% CI = 0.01 to 0.77). We also examined the occurrence of amoeba, Mycobacterium spp., Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus in water samples.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.11150/kansenshogakuzasshi.83.36DOI Listing
January 2009

First report of spontaneous chytridiomycosis in frogs in Asia.

Dis Aquat Organ 2008 Nov;82(2):157-60

Laboratory of Veterinary Pathology, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 229-8501, Japan.

This is the first report of amphibian chytridiomycosis in Asia. We discovered a lethal outbreak in Japan, among 45 exotic frogs from 18 species kept for breeding by a private owner. Of these 45 frogs, 16 died and another 7 were found to be infected by chytrid fungus Batrachochytrium dendrobatidis (Bd) but survived after treatment. Bd was detected in frogs from 9 species (Lepidobatrachus laevis, Ceratophrys cornuta, C. cranwelli, C. ornata, C. calcarata, Chacophrys pierotti, Occidozyga lima, Leptodactylus pentadactylus and Plethodontohyla tuberata).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3354/dao02006DOI Listing
November 2008

Occurrence of Cryptosporidium sp. in snakes in Japan.

Parasitol Res 2008 Sep 13;103(4):801-5. Epub 2008 Jun 13.

Department of Microbiology, Kanagawa Prefectural Institute of Public Health, 1-3-1 Shimomachiya, Chigasaki, Kanagawa, 253-0087, Japan,

The aim of this study was to determine the prevalence of Cryptosporidium in snakes in Japan. Fecal samples or intestinal contents of 469 snakes, consisting of five species, were analyzed and Cryptosporidium oocysts were detected only from the Japanese grass snake Rhabdophis tigrinus. The mean prevalence of Cryptosporidium sp. in Japanese grass snakes was approximately 26% in the region studied. Histopathological observations revealed that the organism caused proliferative enteritis in the small intestine. Sequence analysis of a fragment of the small subunit rRNA gene has shown that the partial sequence of Cryptosporidium sp. isolated from the snakes was identical to that of the Cryptosporidium snake genotype W11 from New Guinea viper boa.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00436-008-1045-xDOI Listing
September 2008

[An outbreak of cryptosporidiosis associated with swimming pools].

Kansenshogaku Zasshi 2008 Jan;82(1):14-9

Nagano Prefectural Hokushin Health Center.

A waterborne outbreak of cryptosporidiosis occurred among visitors at a hotel with a swimming pool, gymnasium, and other sports facilities, in northern Nagano Prefecture. The outbreak began in late August, peaked on August 27 and 28, and tapered off at the beginning of September 2004. On August 30, 288 clinical cases with digestive symptoms, including watery diarrhea, vomiting, abdominal cramps and tenesmus, were reported to local authorities. Among case-patients who submitted stool samples, 74 were positive for Cryptosporidium. Descriptive epidemiology, environmental investigations, and laboratory tests suggested that a fecal accident in the swimming pool by swimmers infected before attending the summer training camp was thought to be the source of contamination, and case-patients were mostly among swimmers. Some other clinical-cases had no history of swimming in the pool during their stay and likely were infected through drinking contaminated self-made sports drinks dissolved in water from contaminated faucets and/or sinks nearby the gymnasium toilet. The sink was used to deal with the aftermath of a toilet accident at the entrance of the toilet by a swimming school attendee on August 21. This report is, to our knowledge, the first of a cryptosporidiosis outbreak associated with swimming pools in Japan.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.11150/kansenshogakuzasshi1970.82.14DOI Listing
January 2008

[Gonococcal infection].

Nihon Rinsho 2007 Mar;65 Suppl 3:423-7

Department of Bacteriology, National Institute of Infectious Diseases.

View Article and Find Full Text PDF

Download full-text PDF

Source
March 2007

Prevalence and genetic properties of Salmonella enterica serovar typhimurium definitive phage type 104 isolated from Rattus norvegicus and Rattus rattus house rats in Yokohama City, Japan.

Appl Environ Microbiol 2007 Apr 16;73(8):2624-30. Epub 2007 Feb 16.

Division of Bacteriology, Chiba Prefectural Institute of Public Health, 666-2 Nitona, Chuo, Chiba City, Chiba, Japan.

Salmonella enterica serovar Typhimurium was isolated from the intestinal contents of Rattus rattus and Rattus norvegicus house rats captured at two buildings, designated buildings J and YS, in Yokohama City, Japan. From October 1997 to September 1998, 52 of 339 (15.3%) house rats were found to carry Salmonella serovar Typhimurium definitive phage type 104 (DT104). In building J, 26 of 161 (16.1%) house rats carried DT104 over the 1-year study period, compared to 26 of 178 (14.6%) rats in building YS. The isolation rates of DT104 from R. rattus and R. norvegicus were similar in the two buildings. Most DT104 strains from building J (24 of 26) showed resistance to ampicillin, chloramphenicol, streptomycin, sulfisoxazole, and tetracycline and contained both the 1.0- and 1.2-kbp integrons, carrying genes pse1, pasppflo-like, aadA2, sulI, and tet(G). All DT104 strains from building YS were resistant to ampicillin and sulfisoxazole, and had the 1.2-kbp integron carrying pse1 and sulI. Cluster analysis of pulsed-field gel electrophoresis patterns of BlnI-digested DT104 DNAs showed that 22 of 26 DT104 strains from building J and 24 of 26 strains from building YS could be grouped into separate clusters each specific for the building origin. These results indicated that DT104 strains were prevalent in house rat colonies in each building and suggest that house rats may play an important role in the epidemiology of DT104.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/AEM.02465-06DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1855591PMC
April 2007

[Isolation of Neisseria meningitidis from healthy persons in Japan].

Kansenshogaku Zasshi 2005 Aug;79(8):527-33

Ishikawa Prefectural Institute of Public Health and Environmental Science.

Between September 2000 and March 2003 healthy subjects in 10 prefectures of Japan were investigated to identify carriers of Neisseria meningitidis. Twenty-five N. meningitidis strains were isolated from 5886 throat swab specimens collected from healthy persons, such as students, elderly, and foreigners. Of the 25 carriers, 9 were teenagers, 15 were in their twenties, and only one was in the fifties. The male-female ratio of the carriers was 17 to 8, showing male dominance. The serogroups of the 25 strains were B (9 strains), Y (4 strains) and non-groupable (12 strains). One of the strains was found to be deficient in gamma-glutamyl aminopeptidase activity, which is an identification marker for N. meningitidis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.11150/kansenshogakuzasshi1970.79.527DOI Listing
August 2005

[Diagnostic tests: Neisseria gonorrhoeae].

Nihon Rinsho 2005 Jul;63 Suppl 7:163-5

Department of Microbiology, Kanagawa Prefectural Institute of Public Health.

View Article and Find Full Text PDF

Download full-text PDF

Source
July 2005