Publications by authors named "Jun Kawase"

10 Publications

  • Page 1 of 1

Bacterial Distribution and Community Structure in Beef Cattle Liver and Bile at Slaughter.

J Food Prot 2021 Nov 24. Epub 2021 Nov 24.

National Institute of Health Sciences 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, JAPAN Kanagawa 210-9501 +81442706563.

In this study, the distribution of hygienic indicator bacteria in cattle livers and bile was examined at slaughterhouses. First, 127 cattle livers with gallbladders were carefully eviscerated from the carcasses at 10 slaughterhouses. Microbiological examination showed that 9 bile (7.1%) and 19 liver parenchyma (15.0%) samples were positive for the family Enterobacteriaceae (EB) with means ± SD of 3.68 ± 4.63 log CFU/mL and 1.59 ± 2.47 log CFU/g, respectively; thus, bacterial contamination was apparent even at the postevisceration stage. Subsequently, 70 cattle livers were obtained at the postprocessing/storage stage from 7 of the ten slaughterhouses; microbiological analysis revealed greater means of EB in the liver parenchyma (means ± SD of 3.00 ± 3.89 log CFU/g, P =0.011) than those at postevisceration stage, suggesting that bacterial dissemination and/or replication occurred in the liver parenchyma during processing and storage. According to 16S rRNA ion semiconductor sequencing analysis of representative samples from 12 cattle, Proteobacteria , Firmicutes , and Actinobacteria were dominant in both the parenchyma and bile, in which EB/ Escherichia coli were predominate among EB-rich livers. These results suggest that bile plays a role as a vehicle for bacterial transmission to the liver parenchyma. This is the first study to demonstrate bacterial distribution and community structure in the liver and biliary microecosystem of cattle at slaughter. Our data provide possible implication of EB testing in bile to screen cattle livers contaminated with high levels of fecal indicator bacteria.
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http://dx.doi.org/10.4315/JFP-21-288DOI Listing
November 2021

Long-Term Grow-Out Affects Colonization Fitness in Coincidence With Altered Microbiota and Lipid Composition in the Cecum of Laying Hens.

Front Vet Sci 2021 18;8:675570. Epub 2021 Jun 18.

Department of Animal Hygiene, Tokyo University of Agriculture, Atsugi City, Japan.

is one of the leading causes of gastrointestinal illness worldwide and is mainly transmitted from chicken through the food chain. Previous studies have provided increasing evidence that this pathogen can colonize and replicate in broiler chicken during its breeding; however, its temporal kinetics in laying hen are poorly understood. Considering the possible interaction between and gut microbiota, the current study was conducted to address the temporal dynamics of in the cecum of laying hen over 40 weeks, with possible alteration of the gut microbiota and fatty acid (FA) components. Following oral infection with 81-176, inocula were stably recovered from ceca for up to 8 weeks post-infection (.). From 16 weeks ., most birds became negative for and remained negative up to 40 weeks . 16S rRNA gene sequencing analyses revealed that most of the altered relative rRNA gene abundances occurred in the order , in which increased relative rRNA gene abundances were observed at >16 weeks . in the families , and . Lipidome analyses revealed increased levels of sterols associated with bile acid metabolisms in the cecum at 16 and/or 24 weeks . compared with those detected at 8 weeks ., suggesting that altered microbiota and bile acid metabolism might underlie the decreased colonization fitness of in the gut of laying hens.
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http://dx.doi.org/10.3389/fvets.2021.675570DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8249580PMC
June 2021

Phylogeny, Prevalence, and Shiga Toxin (Stx) Production of Clinical Escherichia coli O157 Clade 2 Strains Isolated in Shimane Prefecture, Japan.

Curr Microbiol 2021 Jan 23;78(1):265-273. Epub 2020 Oct 23.

Division of Biomedical Food Research, National Institute of Health Sciences, Tonomachi 3-25-26, Kawasaki-ku, Kawasaki City, Kanagawa, 210-9501, Japan.

This study investigated the genetic and pathogenic variation of the subgroups of clade 2 strains of Shiga toxin (Stx)-producing Escherichia coli (STEC) O157. A total of 111 strains of STEC O157 isolated in Shimane prefecture, Japan, were classified in clade 2 (n = 39), clade 3 (n = 16), clade 4/5 (n = 3), clade 7 (n = 14), clade 8 (n = 17), and clade 12 (n = 22) by single-nucleotide polymorphism analysis and lineage-specific polymorphism assay-6. These results showed a distinct difference from our previous study in which clade 3 strains were the most prevalent strains in three other prefectures in Japan, indicating that the clade distribution of O157 strains was different in different geographic areas in Japan. Phylogenetic analysis using insertion sequence (IS) 629 distribution data showed that clade 2 strains formed two clusters, designated 2a and 2b. Stx2 production by cluster 2b strains was significantly higher than by cluster 2a strains (P < 0.01). In addition, population genetic analysis of the clade 2 strains showed significant linkage disequilibrium in the IS629 distribution of the strains in clusters 2a and 2b (P < 0.05). The Φ values calculated using the IS629 distribution data indicated that strains in clusters 2a and 2b were genetically different (P < 0.001). Cluster 2b strains are a highly pathogenic phylogenetic group and their geographic spread may be a serious public health concern.
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http://dx.doi.org/10.1007/s00284-020-02252-4DOI Listing
January 2021

Microbiological Quality Assessment of Game Meats at Retail in Japan.

J Food Prot 2017 Dec;80(12):2119-2126

8 Department of Animal Hygiene, Kitasato University, Higashi 23-35-1, Towada, Aomori 034-8628, Japan.

In this study, we examined the prevalence of Shiga toxin-producing Escherichia coli and Salmonella spp. and the distribution of indicator bacteria in 248 samples of game meats (120 venison and 128 wild boar) retailed between November 2015 and March 2016 in Japan. No Salmonella spp. were detected in any of the samples, whereas Shiga toxin-producing Escherichia coli serotype OUT:H25 (stx, eae) was isolated from one deer meat sample, suggesting a possible source for human infection. Plate count assays indicated greater prevalence of coliforms and E. coli in wild boar meat than in venison, whereas their prevalence in processing facilities showed greater variation than in animal species. The 16S rRNA ion semiconductor sequencing analysis of 24 representative samples revealed that the abundances of Acinetobacter and Arthrobacter spp. significantly correlated with the prevalence of E. coli, and quantitative PCR analyses in combination with selective plate count assay verified these correlations. To our knowledge, this is the first report to characterize the diversity of microorganisms of game meats at retail in Japan, together with identification of dominant microbiota. Our data suggest the necessity of bottom-up hygienic assessment in areas of slaughtering and processing facilities to improve microbiological safety.
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http://dx.doi.org/10.4315/0362-028X.JFP-17-137DOI Listing
December 2017

Rapid and Accurate Diagnosis Based on Real-Time PCR Cycle Threshold Value for the Identification of Campylobacter jejuni, astA Gene-Positive Escherichia coli, and eae Gene-Positive E. coli.

Jpn J Infect Dis 2018 Jan 31;71(1):79-84. Epub 2017 Oct 31.

Shimane Prefectural Institute of Public Health and Environmental Science.

We previously developed a multiplex real-time PCR assay (Rapid Foodborne Bacterial Screening 24 ver.5, [RFBS24 ver.5]) for simultaneous detection of 24 foodborne bacterial targets. Here, to overcome the discrepancy of the results from RFBS24 ver.5 and bacterial culture methods (BC), we analyzed 246 human clinical samples from 49 gastroenteritis outbreaks using RFBS24 ver.5 and evaluated the correlation between the cycle threshold (CT) value of RFBS24 ver.5 and the BC results. The results showed that the RFBS24 ver.5 was more sensitive than BC for Campylobacter jejuni and Escherichia coli harboring astA or eae, with positive predictive values (PPV) of 45.5-87.0% and a kappa coefficient (KC) of 0.60-0.92, respectively. The CTs were significantly different between BC-positive and -negative samples (p < 0.01). All RFBS24 ver.5-positive samples were BC-positive under the lower confidence interval (CI) limit of 95% or 99% for the CT of the BC-negative samples. We set the 95% or 99% CI lower limit to the determination CT (d-CT) to discriminate for assured BC-positive results (d-CTs: 27.42-30.86), and subsequently the PPVs (94.7%-100.0%) and KCs (0.89-0.95) of the 3 targets were increased. Together, we concluded that the implication of a d-CT-based approach would be a valuable tool for rapid and accurate diagnoses using the RFBS24 ver.5 system.
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http://dx.doi.org/10.7883/yoken.JJID.2017.151DOI Listing
January 2018

An Improved Multiplex Real-Time SYBR Green PCR Assay for Analysis of 24 Target Genes from 16 Bacterial Species in Fecal DNA Samples from Patients with Foodborne Illnesses.

Jpn J Infect Dis 2016 May 10;69(3):191-201. Epub 2015 Jul 10.

Shimane Prefectural Institute of Public Health and Environmental Science.

Here, we developed a new version of our original screening system (Rapid Foodborne Bacterial Screening 24; RFBS24), which can simultaneously detect 24 genes of foodborne pathogens in fecal DNA samples. This new version (RFBS24 ver. 5) detected all known stx2 subtypes, enterotoxigenic Escherichia coli (STh genotype), and Vibrio parahaemolyticus (trh2), which were not detected by the original RFBS24 assay. The detection limits of RFBS24 ver. 5 were approximately 5.6 × 10(-2)-5.6 × 10(-5) (ng DNA)/reaction, significantly lower (10- to 100-fold) than those of the original RFBS24 for the 22 target genes analyzed here. We also tested the new assay on fecal DNA samples from patients infected with Salmonella, Campylobacter, or enterohemorrhagic E. coli. The number of bacterial target genes detected by RFBS24 ver. 5 was greater than that detected by RFBS24. RFBS24 ver. 5 combined with an Ultra Clean Fecal DNA Isolation Kit showed adequate performance (sensitivity and specificity 89% and 100%, respectively, for Salmonella spp. and 100% and 83%, respectively, for Campylobacter jejuni) in terms of rapid detection of a causative pathogen during foodborne-illness outbreaks. Thus, RFBS24 ver. 5 is more useful than the previous assay system for detection of foodborne pathogens and offers quick simultaneous analysis of many targets and thus facilitates rapid dissemination of information to public health officials.
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http://dx.doi.org/10.7883/yoken.JJID.2015.027DOI Listing
May 2016

[Current status of bacteriological studies at prefectural and municipal public health institutes in Japan].

Nihon Saikingaku Zasshi 2015 ;70(2):309-18

Ehime Prefectural Institute of Public Health and Environmental Science.

Prefectural and municipal public health institutes are located in prefectures and ordinance-designated cities in Japan, and play a vital role in the regional surveillance of infectious diseases and foodborne illnesses. These institutes, in close cooperation with national institutes such as the National Institute of Infectious Diseases and the National Institute of Health Sciences, construct the national surveillance network for infectious diseases and their causative agents. Bacteriological examinations and studies on a variety of infectious diseases and foodborne illnesses are core activities of prefectural and municipal public health institutes, through which novel and important bacteriological findings have been acquired. In this article, we report the latest findings regarding bacteriological examinations/studies and interesting cases at these institutes, especially concerning foodborne illnesses, tuberculosis, and antimicrobial resistances.
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http://dx.doi.org/10.3412/jsb.70.309DOI Listing
August 2016

Comparison of two methods of bacterial DNA extraction from human fecal samples contaminated with Clostridium perfringens, Staphylococcus aureus, Salmonella Typhimurium, and Campylobacter jejuni.

Jpn J Infect Dis 2014 ;67(6):441-6

Shimane Prefectural Institute of Public Health and Environmental Science.

In this study, 2 methods of DNA extraction were evaluated for use in conjunction with the screening system Rapid Foodborne Bacterial Screening 24 (RFBS24), which employs multiplex real-time SYBR Green polymerase chain reaction (SG-PCR) and can simultaneously detect 24 target genes of foodborne pathogens in fecal DNA samples. The QIAamp DNA Stool mini kit (Qkit) and Ultra Clean Fecal DNA Isolation Kit (Ukit) were used for bacterial DNA extraction from fecal samples artificially inoculated with Clostridium perfringens, Staphylococcus aureus, Salmonella Typhimurium, and Campylobacter jejuni. SG-PCR and simplex real-time quantitative PCR (S-qPCR) analyses revealed higher copy numbers (8-234 times) of DNA in samples obtained using Ukit compared with those obtained using Qkit, resulting in lower cycle threshold values for the Ukit samples of the 4 bacteria on SG-PCR analysis. Fecal DNA samples from patients infected during foodborne outbreaks of Salmonella and Campylobacter were also prepared by Qkit and Ukit methods and subjected to RFBS24 analyses. Higher numbers of RFBS24 bacterial target genes were detected in DNA samples obtained using Ukit compared with those obtained using Qkit. Thus, the higher DNA extraction efficiency of the Ukit method compared with Qkit renders the former more useful in achieving improved detection rates of these 4 bacteria in fecal samples using SG-PCR.
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http://dx.doi.org/10.7883/yoken.67.441DOI Listing
July 2015

Yersinia enterocolitica bacteremia and enterocolitis in a previously healthy 20-month-old girl.

J Infect Chemother 2012 Oct;18(5):756-9

Department of Pediatrics, Hino Municipal Hospital, 4-3-1Tamadaira, Hino, Tokyo 191-0062, Japan.

Yersinia enterocolitica is a gram-negative bacillus that can cause illness ranging from a self-limiting enterocolitis to life-threatening bacteremia. Y. enterocolitica biotype 1B, serotype O:8 (1B/O:8), is the most pathogenic of the Yersinia species because of the presence of the high-pathogenicity island and the Yersinia virulence plasmid (pYV). Here, we report a pediatric case of Y. enterocolitica 1B/O:8 bacteremia and enterocolitis. A 20-month-old girl was admitted to hospital with fever,pharyngitis, and abdominal pain on day 2. Blood culture on admission was positive for Y. enterocolitica 1B/O:8. Stool culture on day 5 after cefotaxime treatment was also positive for Y. enterocolitica 1B/O:8, but only after cold enrichment at 4°C for 3 weeks. PCR assays identified the pYV only in stool specimens, indicating that strains from routine blood culture at 37°C lacked the pYV. The present case showed the usefulness of stool culture with cold enrichment and agglutination test for the diagnosis of Y. enterocolitica infection. We would therefore like to emphasize the importance of collection and preservation of stool specimens for the identification of pYV. To our knowledge, this is the first reported pediatric case of Y. enterocolitica 1B/O:8 bacteremia.
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http://dx.doi.org/10.1007/s10156-011-0353-8DOI Listing
October 2012

Simultaneous Screening of 24 Target Genes of Foodborne Pathogens in 35 Foodborne Outbreaks Using Multiplex Real-Time SYBR Green PCR Analysis.

Int J Microbiol 2010 28;2010. Epub 2010 Sep 28.

Shimane Prefectural Institute of Public Health and Environmental Science, 582 Nishihamasada, Matsue, Shimane 690-0122, Japan.

A set of 8 multiplex real-time SYBR Green PCR (SG-PCR) assays including 3 target primers and an internal amplification control (IAC) primer was simultaneously evaluated in 3 h or less with regard to detection of 24 target genes of 23 foodborne pathogens in 7 stool specimens of foodborne outbreak using a 96-well reaction plate. This assay, combined with DNA extraction (QIAamp DNA Stool Mini kit), offered detection of greater than 10(3)-10(4) foodborne pathogens per g in stool specimens. The products formed were identified using melting point temperature (Tm) curve analysis. This assay was evaluated for the detection of foodborne pathogens in 33 out of 35 cases of foodborne outbreak, using 4 different PCR instruments in 5 different laboratories. No interference from the multiplex real-time SG-PCR assay, including IAC, was observed in stool specimens in any analysis. We found multiplex real-time SG-PCR assay for simultaneous detection of 24 target genes of foodborne pathogens to be comprehensive, rapid, inexpensive, accurate, of high selectivity, and good for screening probability.
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http://dx.doi.org/10.1155/2010/864817DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2948901PMC
July 2011
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