Publications by authors named "Ikuo Uchida"

44 Publications

Intramammary infection caused by Staphylococcus aureus increases IgA antibodies to iron-regulated surface determinant-A, -B, and -H in bovine milk.

Vet Immunol Immunopathol 2021 May 31;235:110235. Epub 2021 Mar 31.

Dairy Hygiene Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, 4 Hitsujigaoka, Toyohira, Sapporo, Hokkaido, 062-0045, Japan. Electronic address:

The aim of this study was to identify virulence factors that have high immunogenicity. An in vivo-expressed Staphylococcus aureus antigen was identified by probing bacteriophage expression libraries of S. aureus with antibodies in bovine mastitis milk. Eighteen clones were isolated, and their proteins were identified as 5 characterised proteins (IsdA, Protein A, IsdB, autolysin, and imidazole glycerol phosphate dehydratase) and 13 hypothetical proteins. We focused on IsdA, IsdB, and IsdH as virulence factors that have a high immunogenicity and are capable of inducing a specific humoral immune response in S. aureus-infected quarters. The optical density (OD) values of IsdA and IsdB IgA and IgG antibodies in milk affected by naturally occurring mastitis caused by S. aureus increased significantly compared to those in healthy milk. In the experimental infection study, the OD values of IsdA- and B-specific IgA and IgG antibodies were significantly increased from 2 to 4 weeks after S. aureus infection compared to day 0 (P < 0.05). On the other hand, we demonstrated that milk from natural and experimental intramammary infections caused by S. aureus are associated with significantly higher IgA levels against IsdH (P < 0.05), but no significant change in IgG levels. Our findings facilitated our understanding of the pathogenicity of S. aureus in bovine mastitis, as well as the mechanisms by which specific humoral immune responses to S. aureus infection are induced. In addition, the results obtained could provide insight into how bovine mastitis can be controlled, for example, through vaccination.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetimm.2021.110235DOI Listing
May 2021

Influence of SOS-inducing agents on the expression of ArtAB toxin gene in and .

Microbiology (Reading) 2020 08 24;166(8):785-793. Epub 2020 Jun 24.

Veterinary Bacteriology, Department of Pathobiology, School of Veterinary Medicine, Rakuno Gakuen University, 582, Bunkyodai-Midorimachi, EbetsuHokkaido, 069-8501, Japan.

subspecies serovar Typhimurium (. Typhimurium) definitive phage type 104 (DT104), subspecies serovar Worthington (. Worthington) and produce ArtA and ArtB (ArtAB) toxin homologues, which catalyse ADP-ribosylation of pertussis toxin-sensitive G protein. ArtAB gene () is encoded on prophage in DT104 and its expression is induced by mitomycin C (MTC) and hydrogen peroxide (HO) that trigger the bacterial SOS response. Although the genetic regulatory mechanism associated with expression is not characterized, it is thought to be associated with prophage induction, which occurs when the RecA-mediated SOS response is triggered. Here we show that subinhibitory concentration of quinolone antibiotics that are SOS-inducing agents, also induce ArtAB production in these strains. Both MTC and fluoroquinolone antibiotics such as enrofloxacin-induced and transcription and -encoding prophage (ArtAB-prophage) in DT104 and . Worthington. However, in , which harbours genes on incomplete prophage, transcription was induced by MTC and enrofloxacin, but prophage induction was not observed. Taken together, these results suggest that SOS response followed by induction of transcription is essential for ArtAB production. HO-mediated induction of ArtAB prophage and efficient production of ArtAB was observed in DT104 but not in . Worthington and . Therefore, induction of expression with HO is strain-specific, and the mode of action of HO as an SOS-inducing agent might be different from those of MTC and quinolone antibiotics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1099/mic.0.000939DOI Listing
August 2020

A long-term animal experiment indicating persistent infection of bovine coronavirus in cattle.

J Vet Med Sci 2018 Jul 18;80(7):1134-1137. Epub 2018 May 18.

Division of Pathology and Pathophysiology, National Institute of Animal Health, 4 Hitsujigaoka, Toyohira, Sapporo, Hokkaido 062-0045, Japan.

A long-term animal experiment involving inoculation with bovine coronavirus (BCoV) was conducted to verify its persistent infection in cattle. Three colostrum-deprived Holstein calves were housed separately in individual rooms of a high-containment facility and inoculated with the BCoV strain Kumamoto/1/07. Until the end of the experiment (1,085, 700 and 280 days, respectively), viral RNAs were detected sporadically by RT-PCR and nested PCR from plasma, nasal discharge, and feces. Seroconversion and titer changes were validated by hemagglutination inhibition tests and neutralization tests. Among the samples, nasal discharge showed a higher viral positivity than feces, which seemed to be associated with positive detection in the plasma. These data demonstrate the existence of persistent infection of BCoV in the respiratory tissues of cattle.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.18-0050DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6068295PMC
July 2018

Phylogenetic Characterization of Salmonella enterica Serovar Typhimurium and Its Monophasic Variant Isolated from Food Animals in Japan Revealed Replacement of Major Epidemic Clones in the Last 4 Decades.

J Clin Microbiol 2018 05 25;56(5). Epub 2018 Apr 25.

Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan

serovar Typhimurium ( Typhimurium) and its monophasic variant ( 4,[5],12:i:-) are the major causes of gastroenteritis in both humans and animals. Pulsed-field gel electrophoresis and multilocus variable-number tandem-repeat analysis have been used widely as subtyping methods for these pathogens in molecular epidemiological analyses, but the results do not precisely reflect phylogenetic information. In this study, we performed a phylogenetic analysis of these serovars using whole-genome sequencing data and identified nine distinct genotypic clades. Then, we established an allele-specific PCR-based genotyping method detecting a clade-specific single nucleotide polymorphism to rapidly identify the clade of each isolate. Among a total of 815 isolates obtained from cattle in Japan between 1977 and 2017, clades 1, 7, and 9 contained 77% of isolates. Obvious replacement of the dominant clone was observed five times in this period, and clade 9, which mostly contains 4,[5],12:i:-, is currently dominant. Among 140 isolates obtained from swine in Japan between 1976 and 2017, clades 3 and 9 contained 64% of isolates. Clade 9 is the latest clone as is the case in cattle isolates. Clade 9 is similar to an epidemic clone from Europe, which is characterized by sequence type 34 (ST34), chromosomal genomic island 3, and a composite transposon containing antimicrobial resistance genes. The increased prevalence of clade 9 among food animals in Japan might be a part of the pandemic of the European 4,[5],12:i:- clone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/JCM.01758-17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5925715PMC
May 2018

Characterization of pertussis-like toxin from Salmonella spp. that catalyzes ADP-ribosylation of G proteins.

Sci Rep 2017 06 1;7(1):2653. Epub 2017 Jun 1.

Bacterial and Parasitic Diseases Research Division, National Institute of Animal Health, Tsukuba, Ibaraki, 305-0856, Japan.

Salmonella Typhimurium definitive phage type (DT) 104 produces a pertussis-like toxin (ArtAB-DT104), which catalyzes ADP-ribosylation of pertussis toxin sensitive G proteins. However, the prevalence of ArtAB and its toxicity have not been established. We report here that, in addition to DT104, S. Worthington, and S. bongori, produce ArtAB homologs, designated ArtAB-SW and ArtAB-Sb, respectively. We purified and characterized these ArtAB toxins, which comprise a 27-kDa A subunit (ArtA) and 13.8-kDa pentameric B subunits (ArtB). While the sequence of the A subunit, which is ADP-ribosyltransferase, is similar to the A subunit sequences of other ArtABs, the B subunit of ArtAB-Sb is divergent compared to the B subunit sequences of other ArtABs. Intraperitoneal injection of purified ArtABs was fatal in mice; the 50% lethal doses of ArtAB-DT104 and ArtAB-SW were lower than that of ArtAB-Sb, suggesting that ArtB plays an influential role in the toxicity of ArtABs. ArtABs catalyzed ADP-ribosylation of G proteins in RAW 264.7 murine macrophage-like cells, and increased intracellular cyclic AMP levels. ArtAB-DT104 and ArtAB-SW, but not ArtAB-Sb, stimulated insulin secretion in mice; however, unlike Ptx, ArtABs did not induce leukocytosis. This disparity in biological activity may be explained by differences in ADP-ribosylation of target G proteins.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-017-02517-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5454059PMC
June 2017

Control of Pseudomonas mastitis on a large dairy farm by using slightly acidic electrolyzed water.

Anim Sci J 2017 Oct 18;88(10):1601-1605. Epub 2017 May 18.

Animal Health Unit, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan.

The disinfection effect of slightly acidic electrolyzed water (SAEW) use in a farm where Pseudomonas mastitis has spread was evaluated. Despite the application of antibiotic therapy and complete cessation of milking infected quarters, numerous new and recurrent Pseudomonas aeruginosa clinical mastitis infections (5.8-7.1% of clinical mastitis cases) occurred on the farm from 2003 to 2005. Procedural changes and equipment modifications did not improve environmental contamination or the incidence of Pseudomonas mastitis. To more thoroughly decontaminate the milking parlor, an SAEW system was installed in 2006. All milking equipment and the parlor environment were sterilized with SAEW (pH 5-6.5, available chlorine 12 parts per million) before and during milking time. After adopting the SAEW system, the incidence of clinical and subclinical Pseudomonas mastitis cases decreased significantly (P < 0.0001) and disappeared. These findings suggest that SAEW effectively reduced the incidence of mastitis in a herd contaminated by Pseudomonas species. This is the first report to demonstrate the effectiveness of disinfection by SAEW against mastitis pathogens in the environment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/asj.12815DOI Listing
October 2017

A case study on Salmonella enterica serovar Typhimurium at a dairy farm associated with massive sparrow death.

Acta Vet Scand 2016 Apr 26;58:23. Epub 2016 Apr 26.

Department of Pathobiology, School of Veterinary Science, Rakuno Gakuen University, 582 Bunkyodai-midorimachi, Ebetsu, 069-8501, Hokkaido, Japan.

Background: Salmonella enterica Typhimurium (S. Typhimurium) is the most common cause of bovine salmonellosis in Japan and where it is also cause of salmonellosis in wild birds. In 2008, a postpartum cow at a dairy farm developed diarrhea caused by S. Typhimurium. The herd was extensively surveilled for Salmonella sp. and we characterized bacterial isolates from this and other cows to determine the source of infection.

Results: Eight isolates of S. Typhimurium from cattle were identified as phage type DT40 and showed a 100 % similarity by pulsed-field gel electrophoresis and the same or similar multiple-locus variable-number tandem-repeat analysis profiles as those of S. Typhimurium isolated from dead sparrows (Passer montanus) collected at Asahikawa in 2006. S. Typhimurium DT40 was considered to be a major cause of high sparrow mortality in Hokkaido in 2005-2006 and 2008-2009, suggesting that DT40 maintained in sparrows was transmitted to cattle.

Conclusions: S. Typhimurium DT40 may be transmitted from sparrows to dairy cattle.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13028-016-0205-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4845370PMC
April 2016

Rapid detection of Salmonella enterica serovar Typhimurium DT104 strains by the polymerase chain reaction.

Acta Vet Scand 2015 Sep 25;57:59. Epub 2015 Sep 25.

Hokkaido Research Station, National Institute of Animal Health, 4 Hitsujigaoka, Toyohira, Sapporo, 062-0045, Japan.

Background: Infection with Salmonella enterica is a major public health concern in developed countries, and multidrug-resistant strains have become increasingly prevalent. S. enterica serovar Typhimurium DT104 (DT104) strains are prevalent in livestock in Japan and include numerous strains of multidrug-resistant S. enterica. Epidemiological analysis of these strains is critical for both agriculture and public health; however, diagnostic tests for these strains have yielded inconsistent results.

Results: We developed a rapid, simple, and inexpensive polymerase chain reaction test to detect multi-drug resistant DT104 strains. We designed primers specific to the prophage ST104 sequence encoded by DT104 strains and assessed the specificity of these primers by assaying a panel of 50 S. enterica isolates. Amplification products of the expected size were generated from the genomes of each of the DT104 strains; however, the ST104 primers failed to amplify products from non-DT104 strains of S. enterica serovar Typhimurium or other S. enterica serovars. Furthermore, a probe generated using the ST104 primers detected a restriction fragment encoding the ST104 region of DT104 by Southern hybridization.

Conclusions: The ST104 primers exhibit specificity to DT104 strains and are suitable for epidemiological applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13028-015-0143-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4583067PMC
September 2015

Extensive amplification of GI-VII-6, a multidrug resistance genomic island of Salmonella enterica serovar Typhimurium, increases resistance to extended-spectrum cephalosporins.

Front Microbiol 2015 10;6:78. Epub 2015 Feb 10.

Bacterial and Parasitic Disease Research Division, National Institute of Animal Health Ibaraki, Japan ; Graduate School of Life and Environmental Sciences, Osaka Prefecture University Osaka, Japan.

GI-VII-6 is a chromosomally integrated multidrug resistance genomic island harbored by a specific clone of Salmonella enterica serovar Typhimurium (S.Typhimurium). It contains a gene encoding CMY-2 β-lactamase (bla CMY-2), and therefore contributes to extended-spectrum cephalosporin resistance. To elucidate the significance of GI-VII-6 on adaptive evolution, spontaneous mutants of S. Typhimurium strain L-3553 were selected on plates containing cefotaxime (CTX). The concentrations of CTX were higher than its minimum inhibition concentration to the parent strain. The mutants appeared on the plates containing 12.5 and 25 mg/L CTX at a frequency of 10(-6) and 10(-8), respectively. No colonies were observed at higher CTX concentrations. The copy number of bla CMY-2 increased up to 85 per genome in the mutants, while the parent strain contains one copy of that in the chromosome. This elevation was accompanied by increased amount of transcription. The bla CMY-2 copy number in the mutants drastically decreased in the absence of antimicrobial selection pressure. Southern hybridization analysis and short-read mapping indicated that the entire 125 kb GI-VII-6 or parts of it were tandemly amplified. GI-VII-6 amplification occurred at its original position, although it also transposed to other locations in the genome in some mutants, including an endogenous plasmid in some of the mutants, leading to the amplification of GI-VII-6 at different loci. Insertion sequences were observed at the junction of the amplified regions in the mutants, suggesting their significant roles in the transposition and amplification. Plasmid copy number in the selected mutants was 1.4 to 4.4 times higher than that of the parent strain. These data suggest that transposition and amplification of the bla CMY-2-containing region, along with the copy number variation of the plasmid, contributed to the extensive amplification of bla CMY-2 and increased resistance to CTX.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2015.00078DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4322709PMC
February 2015

Molecular typing of Salmonella enterica serovar 4,[5],12:i:- isolates from humans, animals and river water in Japan by multilocus variable-number tandem repeat analysis and pulsed-field gel electrophoresis.

J Vet Med Sci 2015 May 25;77(5):609-13. Epub 2015 Jan 25.

Iwate Prefecture Central Livestock Hygiene Service Center, Takizawa, Japan.

Fifty-one Salmonella enterica serovar 4,[5],12:i:- (S. 4, [5],12:i:-) isolates (14 human strains, 34 animal strains and 3 river water strains) which are assumed to be monophasic variants of S. Typhimurium were analyzed using pulsed-field gel electrophoresis (PFGE) and multiple-locus variable-number tandem repeat analysis (MLVA) in order to investigate their genetic diversities and relationships. PFGE, MLVA and combination of them identified 28, 27 and 34 profiles (Simpson's diversity indices [DI]=0.94, 0.96 and 0.97), respectively. No correlations were detected between MLVA clustering and PFGE clustering or phage typing. These results suggested that S. 4,[5],12:i:- originated from multiple S. Typhimurium ancestors. Two cattle and one pig isolates showing identical phage types as well as PFGE and MLVA profiles to human isolates S. 4,[5],12:i:- suggested the existence of the links between human infections and animal reservoirs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.14-0465DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4478744PMC
May 2015

Characteristics of Salmonella enterica serovar 4,[5],12:i:- as a monophasic variant of serovar Typhimurium.

PLoS One 2014 5;9(8):e104380. Epub 2014 Aug 5.

Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Ibaraki, Japan; Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.

Salmonella enterica subspecies enterica serovar 4,[5],12:i:- (S. 4,[5]12:i:-) is believed to be a monophasic variant of S. enterica serovar Typhimurium (S. Typhimurium). This study was conducted to corroborate this hypothesis and to identify the molecular and phenotypic characteristics of the S. 4,[5]12:i:- isolates in Japan. A total of 51 S. 4,[5]12:i:- isolates derived from humans, cattle, swine, chickens, birds, meat (pork), and river water in 15 prefectures in Japan between 2000 and 2010 were analyzed. All the S. 4,[5],12:i:- isolates were identified as S. Typhimurium by two different polymerase chain reactions (PCR) for identification of S. Typhimurium. Of the 51 S. 4,[5],12:i:- isolates, 39 (76.5%) harbored a 94-kb virulence plasmid, which is known to be specific for S. Typhimurium. These data suggest that the S. 4,[5],12:i:- isolates are monophasic variants of S. Typhimurium. The flagellar phase variation is induced by three adjacent genes (fljA, fljB, and hin) in the chromosome. The results of PCR mapping of this region and comparative genomic hybridization analysis suggested that the deletion of the fljAB operon and its flanking region was the major genetic basis of the monophasic phenotype of S. 4,[5],12:i:-. The fljAB operon and hin gene were detectable in eight of the S. 4,[5],12:i:- isolates with common amino acid substitutions of A46T in FljA and R140L in Hin. The introduction of these mutations into S. Typhimurium isolates led to the loss of selectability of isolates expressing the phase 2 H antigen. These data suggested that a point mutation was the genetic basis, at least in part, of the S. 4,[5],12:i:- isolates. The results of phenotypic analysis suggested that the S. 4,[5],12:i:- isolates in Japan consist of multiple distinct clones. This is the first detailed characterization of the S. 4,[5],12:i:- isolates derived from various sources across Japan.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0104380PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4122451PMC
November 2015

Whole-Genome Sequence of CMY-2 β-Lactamase-Producing Salmonella enterica Serovar Typhimurium Strain L-3553.

Genome Announc 2014 Jul 24;2(4). Epub 2014 Jul 24.

Salmonella enterica serovar Typhimurium pulsed-field gel electrophoresis cluster VII has been isolated from cattle populations in Japan since the mid-2000s. Some cluster VII isolates exhibited extended-spectrum cephalosporin resistance defined by the blaCMY-2 gene located in a chromosomal genomic island, GI-VII-6. We determined the whole-genome sequence of strain L-3553 as the reference strain.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/genomeA.00711-14DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4110225PMC
July 2014

Molecular typing of Salmonella enterica serovar Enteritidis isolates from food-producing animals in Japan by multilocus variable-number tandem repeat analysis: evidence of clonal dissemination and replacement.

Acta Vet Scand 2014 May 13;56:31. Epub 2014 May 13.

Hokkaido Research Station, National Institute of Animal Health, 4 Hitsujigaoka, Toyohira, Sapporo 062-0045, Hokkaido, Japan.

Background: Salmonella enterica serovar Enteritidis is a zoonotic pathogen. Human infections are associated with contaminated eggs and egg products. In Japan, since 1989, the incidence of food-borne disease caused by S. Enteritidis has increased and a pandemic has occurred; however, little is known about changes that occurred before and after this pandemic event in the dominant lineage of isolates from food-producing animals. This study aimed to determine the S. Enteritidis lineages in Japan over the last few decades by using multilocus variable-number tandem repeat analysis (MLVA).

Findings: MLVA was used to analyse 79 S. Enteritidis isolates collected from chickens (n = 63), cattle (n = 12), pigs (n = 2), and goats (n = 2) during 1975-2009. The S. Enteritidis isolates showed 14 different MLVA allele combinations, which were classified into two major clusters (A and C) and a minor cluster (B). All the 62 isolates in cluster A were isolated after 1988, whereas 13 of the 17 isolates belonging to cluster B and C were isolated before 1989.

Conclusions: The MLVA results showed that cluster C was predominant before 1989, and isolates in cluster A disseminated since 1989 and replaced the previous dominant clone, suggesting that isolates of cluster A originated from imported S. Enteritidis infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/1751-0147-56-31DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4036731PMC
May 2014

Effects of fluoroquinolone treatment and group housing of pigs on the selection and spread of fluoroquinolone-resistant Campylobacter.

Vet Microbiol 2014 Jun 8;170(3-4):438-41. Epub 2014 Feb 8.

School of Veterinary Medicine, Rakuno Gakuen University, 582 Midorimachi, Bunkyodai, Ebetsu, Hokkaido, Japan. Electronic address:

There are concerns that the use of fluoroquinolones (FQs) and group housing of food animals may contribute to the development of bacterial FQ resistance. Here, we studied the effects of administering FQ to pigs on the selection of FQ-resistant Campylobacter. Fifteen pigs were randomly allocated to either a group treated with FQs (enrofloxacin or norfloxacin), or an untreated control group. The number of FQ-resistant Campylobacter in feces was determined using appropriate selective agar containing enrofloxacin. FQ-resistant Campylobacter from samples of both groups were observed on days 3 and 4. These bacteria persisted for up to 21 days after treatment was discontinued. To evaluate the effect of group housing on the transmission of FQ-resistant Campylobacter, five pigs infected with FQ-sensitive Campylobacter pigs and one pig infected with FQ-resistant Campylobacter were housed together. On day 3, FQ-resistant Campylobacter were isolated from all six pigs. Moreover, FQ-resistant Campylobacter were isolated from environmental samples from the pen. These results indicate that the treatment of pigs with FQs selects for and spreads FQ-resistant Campylobacter among the pen. Therefore, responsible and prudent use of FQs at pig farms is required to prevent the emergence and transmission of FQ-resistant Campylobacter.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetmic.2014.01.036DOI Listing
June 2014

Complete nucleotide sequences of virulence-resistance plasmids carried by emerging multidrug-resistant Salmonella enterica Serovar Typhimurium isolated from cattle in Hokkaido, Japan.

PLoS One 2013 14;8(10):e77644. Epub 2013 Oct 14.

Hokkaido Research Station, National Institute of Animal Health, Sapporo, Hokkaido, Japan.

In the present study, we have shown that virulence-resistance plasmids from emerging multidrug-resistant isolates of Salmonella enterica serovar Typhimurium were derived from a virulence-associated plasmid, essential for systematic invasiveness of S. Typhimurium in mice (pSLT), through acquisition of a large insert containing a resistance island flanked by IS1294 elements. A bla CMY-2-carrying plasmid from a cefotaxime-resistant isolate comprised a segment of Escherichia coli plasmid pAR060302 and the replication region (IncFIB) of a virulence-resistance plasmid. These results provide insights into the evolution of drug resistance in emerging clones of S. Typhimurium.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0077644PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3796477PMC
June 2014

Fluoroquinolone resistance mechanisms in an Escherichia coli isolate, HUE1, without quinolone resistance-determining region mutations.

Front Microbiol 2013 24;4:125. Epub 2013 May 24.

Laboratory of Food Microbiology and Food Safety, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University Ebetsu, Japan.

Fluoroquinolone resistance can cause major clinical problems. Here, we investigated fluoroquinolone resistance mechanisms in a clinical Escherichia coli isolate, HUE1, which had no mutations quinolone resistance-determining regions (QRDRs) of DNA gyrase and topoisomerase IV. HUE1 demonstrated MICs that exceeded the breakpoints for ciprofloxacin, levofloxacin, and norfloxacin. HUE1 harbored oqxAB and qnrS1 on distinct plasmids. In addition, it exhibited lower intracellular ciprofloxacin concentrations and higher mRNA expression levels of efflux pumps and their global activators than did reference strains. The genes encoding AcrR (local AcrAB repressor) and MarR (MarA repressor) were disrupted by insertion of the transposon IS3-IS629 and a frameshift mutation, respectively. A series of mutants derived from HUE1 were obtained by plasmid curing and gene knockout using homologous recombination. Compared to the MICs of the parent strain HUE1, the fluoroquinolone MICs of these mutants indicated that qnrS1, oqxAB, acrAB, acrF, acrD, mdtK, mdfA, and tolC contributed to the reduced susceptibility to fluoroquinolone in HUE1. Therefore, fluoroquinolone resistance in HUE1 is caused by concomitant acquisition of QnrS1 and OqxAB and overexpression of AcrAB-TolC and other chromosome-encoded efflux pumps. Thus, we have demonstrated that QRDR mutations are not absolutely necessary for acquiring fluoroquinolone resistance in E. coli.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2013.00125DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3662882PMC
June 2013

Antigenic variation among recent Japanese isolates of bovine coronaviruses belonging to phylogenetically distinct genetic groups.

Arch Virol 2013 May 27;158(5):1047-53. Epub 2012 Dec 27.

Exotic Disease Research Division, National Institute of Animal Health, 6-20-1 Josuihoncho, Kodaira, Tokyo 187-0022, Japan.

Bovine coronaviruses (BCoVs) isolated in Japan consist of four genetic groups, as determined by phylogenetic analysis using the polymorphic region (aa 456-592) of the S glycoprotein gene. Japanese field isolates of BCoV, reference Kakegawa strain, and vaccine strain 66/H were analyzed for their antigenic properties by indirect immunofluorescence and neutralization testing. There were no significant differences observed among these BCoVs in direct immunofluorescence tests. However, antigenic differences were observed between BCoVs in the neutralization tests, although there was no clear indication of a distinct serotype. A monoclonal antibody, 4H4, against the Kakegawa strain belonging to group 1 lacked significant neutralizing activity for viruses of groups 2, 3, and 4. Therefore, we speculate that the genetic differences between these groups may have altered their antigenicity. Analysis of mutant viruses resistant to neutralization by 4H4 revealed that the antigenic site of the Kakegawa strain maps to amino acid position 284 of the S glycoprotein. This site is not homologous to a known antigenic site (aa 528) of the Quebec strain belonging to group 1, and it is not located in the conformational domain comprising domain I (aa 351-403) and domain II (aa 517-621). This amino acid constitutes a neutralization epitope of BCoV, which is distinct from aa 528 of the Quebec strain. These results indicate antigenic evolution of BCoV between the genetic groups circulating in Japan.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00705-012-1587-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7086937PMC
May 2013

Molecular typing of Salmonella enterica serotype Typhimurium and serotype 4,5,12:i:- isolates from cattle by multiple-locus variable-number tandem-repeats analysis.

Vet Microbiol 2012 Nov 26;160(1-2):264-8. Epub 2012 May 26.

Soya Livestock Hygiene Service Center, 8-3 Midorigaoka, Hamatonnbetu-cho, Esashi-gun, Hokkaido 098-5738, Japan.

To evaluate the usefulness of multiple-locus variable-number tandem-repeats analysis (MLVA) as a tool for the epidemiological analysis of bovine Salmonellosis, Salmonella enterica serotype Typhimurium and serotype 4,5,12:i:- isolates (544 and 18, respectively) obtained from cattle in Hokkaido, Japan, between 1977 and 2009, were characterised by MLVA. MLVA identified 184 profiles versus 121 profiles identified by pulsed-field gel electrophoresis (PFGE). Cluster analysis of the MLVA profiles demonstrated 3 major clusters (A, B, and C) and 3 minor clusters (D, E, and F). Cluster A was associated with PFGE cluster I, which included isolates of definitive phage type 104 (DT104), while cluster C was associated with PFGE cluster VII, which has been disseminating among cattle since 2002. An isolate of serotype Typhimurium belonging to MLVA cluster F, in which 10 serotype 4,5,12:i:- isolates were included, was found to have an MLVA profile closely related to those of serotype 4,5,12:i:- isolates, suggesting that such a strain may be an ancestral candidate for serotype 4,5,12:i:-. Overall, the discriminatory power of MLVA was higher than that of PFGE, and MLVA differentiated between the isolates of the DT104 family, which appeared to be clonal by PFGE. However, this depended on PFGE clusters because PFGE allowed greater discrimination between isolates within PFGE cluster IV and VI than MLVA. The combination of PFGE and MLVA data allowed for improved subtype discrimination and enabled the identification of recently disseminated clones. Hence, MLVA can be used in combination with PFGE to effectively accelerate the molecular epidemiologic investigation of Salmonella.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetmic.2012.05.023DOI Listing
November 2012

Plasmid-mediated florfenicol resistance in Mannheimia haemolytica isolated from cattle.

Vet Microbiol 2012 Mar 7;155(2-4):444-7. Epub 2011 Oct 7.

Tohoku Research Station, Viral Disease and Epidemiology Research Division, National Institute of Animal Health, 31 Uminai, Shichinohe, Kamikita, Aomori 039-2586, Japan.

The aim of this study was to analyse a florfenicol-resistant Mannheimia haemolytica isolated from a calf to determine the genetic basis of its florfenicol-resistance. The antimicrobial susceptibility and plasmid content of the isolate were determined. A florfenicol resistant plasmid carrying the floR gene was identified by PCR and transformed into Escherichia coli JM109 and HB101 strains. The plasmid was then mapped and sequenced completely. The isolate was resistant to chloramphenicol, florfenicol, oxytetracycline, kanamycin, dihydrostreptomycin, nalidixic acid, ampicillin, and amoxicillin; it carried a floR plasmid of 7.7kb, designated pMH1405. The mobilisation and replication genes of pMH1405 showed extensive similarity to the 5.1-kb pDN1 plasmid from Dichelobacter nodosus and the 10.8-kb pCCK381 plasmid from Pasteurella multocida. An adjacent 2.4-kb segment was highly homologous to the TnfloR region of the E. coli BN10660 plasmid. A plasmid-mediated floR gene was responsible for florfenicol resistance in the bovine respiratory tract pathogen M. haemolytica. The pMH1405 plasmid is the smallest floR-carrying plasmid reported to date. To the best of our knowledge, this is the first report of a florfenicol-resistant gene in M. haemolytica.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetmic.2011.09.033DOI Listing
March 2012

Change in antimicrobial resistance pattern in Salmonella enterica serovar Typhimurium isolates detected in a beef cattle farm.

J Vet Med Sci 2012 Jan 23;74(1):93-7. Epub 2011 Aug 23.

Aizu Livestock Hygiene Service Center, Aizuwakamatsu, Fukushima, Japan.

Multidrug-resistant Salmonella enterica serovar Typhimurium (S. Typhimurium) isolates with four different antimicrobial resistance patterns obtained from a beef cattle farm were characterized to determine their clonality. Macrorestriction analysis of genomic DNA revealed that these four isolates are closely related to each other and can be classified as a newly emerged pulsed-field gel electrophoresis type among cattle: cluster VII. Three of the four isolates showed resistance to extended-spectrum cephalosporins (ESCs), and this resistance was mediated by AmpC β-lactamase encoded by the bla(CMY-2) gene in a 190-kbp IncA/C plasmid. Results of restriction analysis and IncA/C backbone PCR suggest that the three 190-kbp plasmids are identical and that a 70-kbp IncA/C plasmid of the ESC-susceptible isolate is derived from the 190-kbp plasmid by a deletion event. Three isolates harboured a virulence-resistance plasmid (165 or 180 kbp), and restriction analysis revealed that these plasmids were identical or closely related to each other. These results suggest that the four S. Typhimurium cluster VII isolates originate from a common ancestor that probably invaded the farm prior to the salmonellosis outbreak. Antimicrobial resistance patterns may not necessarily reflect the relationships of the isolates.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.11-0240DOI Listing
January 2012

Characterization of Salmonella enterica serovar Typhimurium isolates harboring a chromosomally encoded CMY-2 beta-lactamase gene located on a multidrug resistance genomic island.

Antimicrob Agents Chemother 2011 Sep 27;55(9):4114-21. Epub 2011 Jun 27.

Safety Research Team, National Institute of Animal Health, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan.

Since 2004, extended-spectrum cephalosporin (ESC)-resistant Salmonella enterica serovar Typhimurium (S. Typhimurium) isolates have been detected from cattle in the northern major island of Japan, Hokkaido. Resistance to ESCs was found to be mediated by CMY-2 type β-lactamase among 22 epidemiologically unrelated isolates showing indistinguishable pulsed-field gel electrophoresis patterns. Southern blot analysis using I-CeuI-digested genomic DNA demonstrated that the CMY-2 β-lactamase gene (bla(CMY-2)) was integrated in a 2.5-Mb chromosomal fragment. Genetic analysis of S. Typhimurium isolate L-3553 indicated that bla(CMY-2) was located on a unique 125-kb genomic island, GI-VII-6, which consists of 140 open reading frames. Pairwise alignment of GI-VII-6 and Escherichia coli plasmid pAR060302 (size, 167 kb) revealed that a large proportion of GI-VII-6 (99%) shows a high sequence similarity (>99%) with pAR060302. GI-VII-6 contains 11 antimicrobial resistance genes including sul1, qacEΔ1, aadA2, and dfrA12 in the aadA2 region; sugE1 and bla(CMY-2) in the bla(CMY-2) region; and sul2, strA, strB, tet(A), and floR in the floR region. Two directly repeated IS26 copies were present at both ends of GI-VII-6. Junction regions of GI-VII-6 were flanked by an 8-bp direct repeat, indicating that GI-VII-6 was acquired by transposition involving IS26 transposase. PCR scanning revealed that the overall structure of GI-VII-6 was almost identical in the 22 isolates. Phylogenetic analysis suggested that S. Typhimurium isolates harboring GI-VII-6 belong to a different genomic lineage than other whole-genome-sequenced S. Typhimurium strains. These data indicate that a particular clone of S. Typhimurium harboring GI-VII-6 has spread among the cattle population in Hokkaido, Japan.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/AAC.00560-11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3165313PMC
September 2011

Detection of a novel bovine papillomavirus type 11 (BPV-11) using xipapillomavirus consensus polymerase chain reaction primers.

Arch Virol 2011 Jul 22;156(7):1281-5. Epub 2011 Mar 22.

Hokkaido Research Station, National Institute of Animal Health, 4 Hitsujigaoka, Toyohira, Sapporo, 062-0045, Japan.

Polymerase chain reaction-based bovine papillomavirus (BPV) detection methods using a combination of two primer sets, subAup/subAdw and subBup/subBdw, have enabled the broad-spectrum detection of most characterized BPV types. These methods were used to detect the partial L1 nucleotide sequence of BPV types from 167 cutaneous warts in cattle. Three potentially new viruses were detected using subBup/subBdw primer sets. The partial nucleotide sequences of these viruses were most similar to BPV-4, -6 and -9. Whole genome sequencing of one sample defines a new BPV type in the genus Xipapillomavirus, designated BPV-11.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00705-011-0970-7DOI Listing
July 2011

Molecular epidemiology of Salmonella enterica serovar typhimurium isolates from cattle in hokkaido, Japan: evidence of clonal replacement and characterization of the disseminated clone.

Appl Environ Microbiol 2011 Mar 14;77(5):1739-50. Epub 2011 Jan 14.

Hokkaido Research Station, National Institute of Animal Health, 4 Hitsujigaoka, Toyohira, Sapporo, Hokkaido 062-0045, Japan.

The molecular epidemiology of 545 Salmonella enterica serovar Typhimurium isolates collected between 1977 and 2009 from cattle in Hokkaido, Japan, was investigated using pulsed-field gel electrophoresis (PFGE). Nine main clusters were identified from 116 PFGE patterns. Cluster I comprised 248 isolates, 243 of which possessed a sequence specific to definitive phage type 104 (DT104) or U302. The cluster I isolates were dominant in 1993 to 2003, but their numbers declined beginning in 2004. Beginning in 2002, an increase was observed in the number of cluster VII isolates, consisting of 21 PFGE patterns comprising 165 isolates. A total of 116 isolates representative of the 116 PFGE profiles were analyzed by multilocus variable-number tandem-repeat analysis (MLVA). Other than two drug-sensitive isolates, 19 isolates within cluster VII were classified in the same cluster by MLVA. Among the cluster VII isolates, an antibiotic resistance type showing resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, tetracycline, kanamycin, cefazolin, and sulfamethoxazole-trimethoprim and a resistance type showing resistance to ampicillin, streptomycin, sulfonamides, tetracycline, and kanamycin were found in 23 and 125 isolates, respectively. In the 19 isolates representative of cluster VII, the bla(TEM-1) gene was found on a Salmonella serotype Typhimurium virulence plasmid, which was transferred to Escherichia coli by electroporation along with resistance to two to four other antimicrobials. Genomic analysis by subtractive hybridization and plasmid analysis suggested that the bla(TEM-1)-carrying virulence plasmid has a mosaic structure composed of elements of different origin. These results indicate an emerging multidrug-resistant S. Typhimurium clone carrying a virulence-resistance plasmid among cattle in Hokkaido, Japan.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/AEM.01910-10DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3067258PMC
March 2011

Genetic variation among Staphylococcus aureus strains from bovine milk and their relevance to methicillin-resistant isolates from humans.

J Clin Microbiol 2010 Jun 14;48(6):2130-9. Epub 2010 Apr 14.

Research Team for Bacterial/Parasitic Diseases, Hokkaido Research Station, National Institute of Animal Health, 4 Hitsujigaoka, Toyohira-ku, Sapporo, Hokkaido 062-0045, Japan.

In genetic analysis of bovine Staphylococcus aureus isolates that are recognized as an important pathogenic bacterium in bovine mastitis, multilocus sequence typing (MLST) showed strong correlation to the results of pulsed-field gel electrophoresis, coa PCR-restriction fragment length polymorphism (RFLP), spa typing, and the coagulase serotyping method. According to MLST results, strains derived from sequence type 97 (ST97) and ST705 were suggested as not only dominant bovine S. aureus lineages in Japan but also pandemic bovine S. aureus lineages. Although both lineages seem to be distantly related to each other by phylogenetic analysis, both had common characteristics, i.e., lukM/lukF'-PV and coagulase serotype VI. These characteristics were very rare among minor bovine strains and human strains and may contribute to the host specificity of these lineages. Four methicillin-resistant S. aureus (MRSA) isolates were first confirmed from bovine milk in Japan; these isolates showed geno- and serotypes that were identical or similar to those of human MRSA isolates in Japan (ST5, staphylococcal cassette chromosome mec type II [SCCmec II], Spa type t002 or t375, and coagulase serotype II, and ST89, SCCmec IIIa, Spa type t5266, and coagulase serotype I). ST5 and ST89 are uncommon among bovine isolates in the world, whereas these STs are common among human MRSA isolates in Japan.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/JCM.01940-09DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2884479PMC
June 2010

Antimicrobial resistance and genetic characteristics of Salmonella Typhimurium isolated from horses in Hokkaido, Japan.

J Vet Med Sci 2009 Aug;71(8):1115-9

Equine Research Institute, Japan Racing Association, Tochigi, Japan.

In this study, we examined the antimicrobial susceptibility of 16 Salmonella Typhimurium isolates obtained from horses, and applied several genetic methods, namely polymerase chain reaction (PCR) for detecting class 1 integrons, multiplex PCR for detecting multidrug resistant S. Typhimurium definitive phage type 104 (MR-DT104), and fluorescent amplified-fragment length polymorphism (FAFLP). Seven isolates with an ampicillin, chloramphenicol, streptomycin, sulfonamide, and tetracycline (ACSSuT) type resistance pattern, harbored two class 1 integrons with sizes of 1.2 and 1.0 kb, and were identified as DT104 by bacteriophage typing. These isolates also showed a typical MR-DT104 amplification pattern, which was positive for flo(st), spvC, invA and int, in multiplex PCR. In the FAFLP analysis, the equine DT104 isolates and the previously reported ACSSuT-type resistant bovine isolates, which were also isolated in Hokkaido were included in the same genetic cluster. Our results retrospectively indicate that MR-DT104 infection has existed in horses in Japan at least since 1996, and it was suggested that there is a highly epidemiological relationship between the equine MR-DT104 isolates and certain multidrug resistant bovine isolates in the same area.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.71.1115DOI Listing
August 2009

Salmonella enterica serotype Typhimurium DT104 ArtA-dependent modification of pertussis toxin-sensitive G proteins in the presence of [32P]NAD.

Microbiology (Reading) 2009 Nov 20;155(Pt 11):3710-3718. Epub 2009 Aug 20.

National Institute of Animal Health, Tsukuba, Ibaraki 305-0856, Japan.

Salmonella enterica serotype Typhimurium (S. Typhimurium) definitive phage type (DT) 104 has become a widespread cause of human and other animal infections worldwide. The severity of clinical illness in S. Typhimurium DT104 outbreaks suggests that this strain possesses enhanced virulence. ArtA and ArtB - encoded by a prophage in S. Typhimurium DT104 - are homologues of components of pertussis toxin (PTX), including its ADP-ribosyltransferase subunit. Here, we show that exposing DT104 to mitomycin C, a DNA-damaging agent, induced production of prophage-encoded ArtA/ArtB. Pertussis-sensitive G proteins were labelled in the presence of [(32)P]NAD and ArtA, and the label was released by HgCl(2), which is known to cleave cysteine-ADP-ribose bonds. ADP-dependent modification of G proteins was markedly reduced in in vitro-synthesized ArtA(6Arg-Ala) and ArtA(115Glu-Ala), in which alanine was substituted for the conserved arginine at position 6 (necessary for NAD binding) and the predicted catalytic glutamate at position 115, respectively. A cellular ADP-ribosylation assay and two-dimensional electrophoresis showed that ArtA- and PTX-induced ADP-ribosylation in Chinese hamster ovary (CHO) cells occur with the same type of G proteins. Furthermore, exposing CHO cells to the ArtA/ArtB-containing culture supernatant of DT104 resulted in a clustered growth pattern, as is observed in PTX-exposed CHO cells. Hydrogen peroxide, an oxidative stressor, also induced ArtA/ArtB production, suggesting that these agents induce in vivo synthesis of ArtA/ArtB. These results, taken together, suggest that ArtA/ArtB is an active toxin similar to PTX.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1099/mic.0.028399-0DOI Listing
November 2009

Antimicrobial resistance and genetic characterization of fluoroquinolone-resistant Mannheimia haemolytica isolates from cattle with bovine pneumonia.

Vet Microbiol 2009 Oct 19;139(1-2):74-9. Epub 2009 Apr 19.

Tohoku Research Station, National Institute of Animal Health, Kamikita, Aomori, Japan.

Antimicrobial susceptibility and molecular characterization of quinolone-resistant Mannheimia haemolytica was conducted. The antimicrobial susceptibility of 229 M. haemolytica isolates which were obtained from cattle with bovine respiratory disease during the period 1984-2006, was determined using 14 antimicrobial agents. Of the 229 isolates, 114 (49.8%) were resistant to at least one agent and resistance rates ranged from 4.8% to 31.4%. Resistance rates for dihydrostreptomycin, oxytetracycline, doxycycline, ampicillin, amoxicillin, thiamphenicol, kanamycin chloramphenicol, nalidixic acid, enrofloxacin, and danofloxacin were 31.4%, 20.5%, 18.3%, 19.2%, 16.6%, 10.9%, 11.4%, 10.5%, 17.0%, 4.8% and 4.8%, respectively. The nucleotide sequences of the quinolone resistance-determining regions of the gyrA and parC genes of nalidixic acid-resistant M. haemolytica were determined. All nalidixic acid-resistant strains possessed at least one amino acid substitution in each of the GyrA and ParC fragments investigated. These results suggest that M. haemolytica require at least one amino acid substitution in both GyrA and ParC in order to attain significant levels of resistance to quinolones. All fluoroquinolone-resistant isolates belonged to serotype 6, and their genotype by PFGE analysis was identical. This result indicates that fluoroquinolone-resistant M. haemolytica strains have clonally expanded.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetmic.2009.04.020DOI Listing
October 2009

Phylogenetic studies of bovine coronaviruses isolated in Japan.

J Vet Med Sci 2009 Jan;71(1):83-6

Hokkaido Research Station, National Institute of Animal Health, 4 Hitsujigaoka, Toyohira, Sapporo, Hokkaido, Japan.

Molecular analysis of the polymorphic region of the bovine coronavirus (BCoV)-S gene using recent Japanese field isolates and reference strains revealed that the 148 isolates collected from 1999 to 2008 from 13 prefectures, covering all regions of Japan (Hokkaido, Tohoku, Kanto, Chubu, Kinki, Chugoku, Shikoku, and Kyusyu region) and divided into 3 clusters, show distinctive divergence from the prototype enteric BCoV strains. Almost all isolates after 2005 were clustered into group 4, and there was no regional specificity in these clusters. To differentiate the genotypes without sequencing, a simple technique-reverse transcriptase-polymerase chain reaction/restriction fragment length polymorphism analysis (RT-PCR/RFLP)-was developed. The availability of a simple and easy diagnostic assay will enable larger epidemiological studies of BCoV.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.71.83DOI Listing
January 2009

Bovine papillomavirus type 9 induces epithelial papillomas on the teat skin of heifers.

Vet Microbiol 2009 May 13;136(3-4):347-51. Epub 2008 Nov 13.

Hokkaido Research Station, National Institute of Animal Health, 4 Hitsujigaoka, Toyohira, Sapporo 062-0045, Japan.

Experiments were carried out to investigate whether papillomas could be induced on the teat skin of heifers by intradermal injection with bovine papillomavirus type 9 (BPV-9). Three heifers (#1 and 2, two 0.5-year-old Holsteins; #3, a 1.5-year-old Japanese Black) were injected with BPV-9 and one heifer (#4, a 0.5-year-old Holstein) was mock-infected. Viral DNA load in the inocula was quantified by real-time polymerase chain reaction assay and adjusted to 1.56x10(12) copies per injection. Papillomas appeared at the injection sites in the BPV-9-injected heifers #1, 2 and 3 and grew over the 8 (#1 and 2) and 4 (#3)mo observation period, respectively. However, no papillomas were found in the mock-infected heifer #4. The experimentally induced papillomas were excised and examined. Histologically, the lesions were characterized by hyperplasia of the epidermis with hyperkeratosis and marked acanthosis and were morphologically similar to naturally occurring lesions. BPV-9 DNA and bovine papillomavirus capsid antigen were abundant in the lesions. Therefore, we conclude that BPV-9 is an etiological agent causing epithelial papillomas on the teat skin of heifers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetmic.2008.11.003DOI Listing
May 2009