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Jugsharan Singh Virdi - One of the best experts on this subject based on the ideXlab platform.
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The enigma of Yersinia enterocolitica Biovar 1A.
Critical reviews in microbiology, 2010Co-Authors: Neeru Bhagat, Jugsharan Singh VirdiAbstract:Yersinia enterocolitica, an important food- and water-borne enteropathogen causes acute diarrhea, terminal ileitis, and mesenteric lymphadenitis. It is represented by six Biovars (1A, 1B, 2-5). The Biovar 1A strains are generally regarded as avirulent as they lack pYV plasmid and major chromosomal virulence genes. Despite this, some Biovar 1A strains produce disease symptoms indistinguishable from that produced by known pathogenic Biovars (1B, 2-5). Suggested prospective studies to understand pathogenic potential of Biovar 1A should focus on role of insecticidal toxins, urease, protease, superoxide dismutase, and host responses. These studies should also take into account the clonal groups of Biovar 1A.
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Molecular and biochemical characterization of urease and survival of Yersinia enterocolitica Biovar 1A in acidic pH in vitro
BMC microbiology, 2009Co-Authors: Neeru Bhagat, Jugsharan Singh VirdiAbstract:Background Yersinia enterocolitica, an important food- and water-borne enteric pathogen is represented by six Biovars viz. 1A, 1B, 2, 3, 4 and 5. Despite the lack of recognized virulence determinants, some Biovar 1A strains have been reported to produce disease symptoms resembling that produced by known pathogenic Biovars (1B, 2-5). It is therefore imperative to identify determinants that might contribute to the pathogenicity of Y. enterocolitica Biovar 1A strains. Y. enterocolitica invariably produces urease and the role of this enzyme in the virulence of Biovar 1B and Biovar 4 strains has been reported recently. The objective of this work was to study genetic organization of the urease (ure) gene complex of Y. enterocolitica Biovar 1A, biochemical characterization of the urease, and the survival of these strains under acidic conditions in vitro.
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distribution of virulence associated genes in yersinia enterocolitica Biovar 1a correlates with clonal groups and not the source of isolation
Fems Microbiology Letters, 2007Co-Authors: Neeru Bhagat, Jugsharan Singh VirdiAbstract:Yersinia enterocolitica, an important food- and water-borne enteric pathogen, is represented by six Biovars viz. 1A, 1B and 2-5. Some Biovar 1A strains, despite lacking virulence plasmid (pYV) and chromosomal virulence genes, have been reported to cause symptoms similar to that produced by isolates belonging to known pathogenic Biovars. Virulence-associated genes viz. ail, virF, inv, myfA, ystA, ystB, ystC, tccC, hreP, fepA, fepD, fes, ymoA and sat were studied in 81 clinical and nonclinical strains of Y. enterocolitica Biovar 1A by PCR amplification. All strains lacked ail, virF, ystA and ystC genes. The distribution of other genes with respect to clonal groups revealed that four genes viz. ystB, hreP, myfA and sat were associated exclusively with strains belonging to clonal group A. The clonal groups A and B were differentiated previously based on rep (REP-/ERIC) - PCR genomic fingerprinting. The distribution of virulence-associated genes, however, did not differ significantly between clinical and nonclinical strains. In strains of Y. enterocolitica Biovar 1A, clonal groups seem to reflect virulence potential better than the source (clinical vs. nonclinical) of isolation.
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Molecular characterization of β‐lactamase genes blaA and blaB of Yersinia enterocolitica Biovar 1A
FEMS microbiology letters, 2006Co-Authors: Sachin Sharma, Shilpi Mittal, Sarita Mallik, Jugsharan Singh VirdiAbstract:The β-lactamase genes blaA and blaB were detected by PCR amplification in strains of Yersinia enterocolitica Biovar 1A isolated from India, Germany, France and the USA. Both genes were detected in all strains. Polymerase chain reaction-restriction fragment length polymorphism revealed genetic heterogeneity in blaA but not in blaB . Cluster analysis of blaA restriction profiles grouped the strains into three groups. The blaA gene of Y. enterocolitica Biovar 1A showed a high degree of sequence homology to that of Y. enterocolitica 8081 (Biovar 1B) and Y. enterocolitica Y-56 (Biovar 4), whereas homology was low with class A β-lactamase genes of other members of the family Enterobacteriaceae . The p I 8.7 of enzyme Bla-A of Y. enterocolitica Biovar 1A was similar to that of Biovars 2, 3 and 4. The enzyme Bla-B focused at 6.8 and 7.1, indicating that Biovar 1A strains produced a ‘B-like’ enzyme. This is the first study to have investigated the genetic heterogeneity of the β-lactamase genes of Y. enterocolitica .
Neeru Bhagat - One of the best experts on this subject based on the ideXlab platform.
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The enigma of Yersinia enterocolitica Biovar 1A.
Critical reviews in microbiology, 2010Co-Authors: Neeru Bhagat, Jugsharan Singh VirdiAbstract:Yersinia enterocolitica, an important food- and water-borne enteropathogen causes acute diarrhea, terminal ileitis, and mesenteric lymphadenitis. It is represented by six Biovars (1A, 1B, 2-5). The Biovar 1A strains are generally regarded as avirulent as they lack pYV plasmid and major chromosomal virulence genes. Despite this, some Biovar 1A strains produce disease symptoms indistinguishable from that produced by known pathogenic Biovars (1B, 2-5). Suggested prospective studies to understand pathogenic potential of Biovar 1A should focus on role of insecticidal toxins, urease, protease, superoxide dismutase, and host responses. These studies should also take into account the clonal groups of Biovar 1A.
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Molecular and biochemical characterization of urease and survival of Yersinia enterocolitica Biovar 1A in acidic pH in vitro
BMC microbiology, 2009Co-Authors: Neeru Bhagat, Jugsharan Singh VirdiAbstract:Background Yersinia enterocolitica, an important food- and water-borne enteric pathogen is represented by six Biovars viz. 1A, 1B, 2, 3, 4 and 5. Despite the lack of recognized virulence determinants, some Biovar 1A strains have been reported to produce disease symptoms resembling that produced by known pathogenic Biovars (1B, 2-5). It is therefore imperative to identify determinants that might contribute to the pathogenicity of Y. enterocolitica Biovar 1A strains. Y. enterocolitica invariably produces urease and the role of this enzyme in the virulence of Biovar 1B and Biovar 4 strains has been reported recently. The objective of this work was to study genetic organization of the urease (ure) gene complex of Y. enterocolitica Biovar 1A, biochemical characterization of the urease, and the survival of these strains under acidic conditions in vitro.
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distribution of virulence associated genes in yersinia enterocolitica Biovar 1a correlates with clonal groups and not the source of isolation
Fems Microbiology Letters, 2007Co-Authors: Neeru Bhagat, Jugsharan Singh VirdiAbstract:Yersinia enterocolitica, an important food- and water-borne enteric pathogen, is represented by six Biovars viz. 1A, 1B and 2-5. Some Biovar 1A strains, despite lacking virulence plasmid (pYV) and chromosomal virulence genes, have been reported to cause symptoms similar to that produced by isolates belonging to known pathogenic Biovars. Virulence-associated genes viz. ail, virF, inv, myfA, ystA, ystB, ystC, tccC, hreP, fepA, fepD, fes, ymoA and sat were studied in 81 clinical and nonclinical strains of Y. enterocolitica Biovar 1A by PCR amplification. All strains lacked ail, virF, ystA and ystC genes. The distribution of other genes with respect to clonal groups revealed that four genes viz. ystB, hreP, myfA and sat were associated exclusively with strains belonging to clonal group A. The clonal groups A and B were differentiated previously based on rep (REP-/ERIC) - PCR genomic fingerprinting. The distribution of virulence-associated genes, however, did not differ significantly between clinical and nonclinical strains. In strains of Y. enterocolitica Biovar 1A, clonal groups seem to reflect virulence potential better than the source (clinical vs. nonclinical) of isolation.
Bernd Wiedemann - One of the best experts on this subject based on the ideXlab platform.
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β-Lactamase expression in Yersinia enterocolitica Biovars 1A, 1B and 3
Journal of medical microbiology, 2000Co-Authors: Ingo Stock, Peter Heisig, Bernd WiedemannAbstract:Characteristic patterns of β-lactam susceptibility are associated with different Biovars of Yersinia enterocolitica. In a previous study differences in β-lactam susceptibility among Biovar 2, 4 and 5 strains were largely attributed to differences in expression of β-lactamase A (BlaA) and β-lactamase B (BlaB). The basis for differences in β-lactam susceptibility of strains of Biovars 1A, 1B and 3 is now considered. All the strains examined had blaB; nine of 31 Biovar 3 strains and two of 13 Biovar 1B strains had blaA, but PCR did not amplify blaA from Biovar 1A strains. Nevertheless, inhibition data indicated that the majority of uninduced Biovar 1A strains expressed BlaA and BlaB in similar amounts. Strong inducibility was seen in all these strains. Biovar 1B strains (which were less inducible than strains of Biovar 1A) predominantly produced BlaA without induction; ticarcillin-sensitive strains of Biovar 3 produced only BlaB but were not inducible; without induction Biovar 3 strains resistant to ticarcillin and amoxycillin/clavulanate produced either predominantly BlaA, predominantly BlaB or exclusively BlaB and induction was demonstrated except for strains producing BlaB alone; Biovar 3 strains resistant to ticarcillin but sensitive to amoxycillin/clavulanate predominantly produced BlaA without induction and were inducible for β-lactamase activity. After induction, nearly all strains predominantly or exclusively produced BlaB. Although PCR amplification fragments with primers specific for blaA were obtained only from some strains, the induction and inhibition data suggest that all Y. enterocolitica strains possess enzymes related to BlaA- as well as BlaB. Nevertheless, expression of the β-lactamase is regulated differently in different Biovars and varies within most Biovars. Failure to predict β-lactamase expression profiles from MIC data indicates the presence of additional mechanisms contributing to differences in susceptibility.
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Expression of β-lactamases in Yersinia enterocolitica strains of Biovars 2, 4 and 5
Journal of medical microbiology, 1999Co-Authors: Ingo Stock, Peter Heisig, Bernd WiedemannAbstract:Characteristic patterns of susceptibility to β-lactam antibiotics are associated with different Biovars of Yersinia enterocolitica. To elucidate the basis for these differences, the β-lactamases of strains of Y. enterocolitica Biovars 4 (n = 63), 2 (n = 12) and 5 (n = 10) were characterised. PCR fragments were generated from the β-lactamase A (blaA) and B (blaB) genes; in addition, β-lactamase induction tests were performed with imipenem as the inducer and β-lactamase inhibition assays were undertaken with aztreonam and clavulanic acid. All the strains yielded PCR amplification fragments with primers to blaA and blaB. Biovar 4 strains had uniform patterns of β-lactamase induction and inhibition: uninduced Biovar 4 strains predominantly expressed BlaA, but low-level expression of BlaB was also detected; after induction, Biovar 4 strains predominantly produced BlaB. β-Lactamase expression varied between and within Biovars 2 and 5: uninduced strains predominantly expressed either BlaA or BlaB, or exclusively BlaB; after induction BlaB was predominantly or exclusively expressed. Both the basal and induced levels of β-lactamase varied within Biovars 2 and 5. Some Biovar 5 strains were not inducible; these predominantly produced BlaA. The results of this study show that Biovar 2, 4 and 5 strains contain both blaA and blaB, but that the expression of the enzymes is regulated differently between the Biovars, and varies within Biovars 2 and 5. There was some correlation between antibiogram and the clusters defined from the β-lactamase induction and inhibition tests, but it was not possible to predict β-lactamase expression profiles from MIC data.
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identification and natural antibiotic susceptibility of morganella morganii
Diagnostic Microbiology and Infectious Disease, 1998Co-Authors: Ingo Stock, Bernd WiedemannAbstract:Our data should elucidate whether or not natural antibiotic susceptibility can be used as an aid for subspecies or Biovar discrimination of Morganella morganii (II). Furthermore, our goal was to create a database of the natural susceptibility of M. morganii (III) and we were interested in the relative frequency of the recently described subspecific taxa (I). On the basis of trehalose fermentation (TRE), ornithine decarboxylase (ODC), and lysine decarboxylase (LDC) activities, we determined the Biovar for 90 clinical isolates of M. morganii. Within these strains we examined the natural antibiotic susceptibility of 53 morganellae to 70 antibiotics by determination of the MICs with a microdilution procedure. (I): 80 strains (89%) of all morganellae belonged to M. morganii ssp. morganii (TRE-), with Biovar A (LDC-, ODC+) predominating (67 strains). The remaining strains of this subspecies were identified as Biovar B (LDC+, ODC+; 12 strains) and Biovar C (LDC-, ODC-, one strain). Ten strains of M. morganii ssp. sibonii (TRE+) were found: four strains belonged to Biovar F (LDC variable, ODC-) and six strains to Biovar G (LDC-, ODC). (II): With one exception we found no significant differences in antibiotic susceptibility between different Biovars. M. morganii ssp. morganii strains are more susceptible to tetracycline than strains of M. morganii ssp. sibonii, but there is no evidence that this parameter could be useful to differentiate Biovars within a subspecies. It could be shown that 8 of 30 strains of Biovar A and 2 of 12 strains of Biovar B were tetracycline resistant. However, one M. morganii ssp. sibonii strain was clinically susceptible to tetracycline according to French and American standards. (III): The natural population of M. morganii is primarily (naturally) resistant to certain penicillins like benzylpenicillin, oxacillin, and amoxicillin, first and second generation cephalosporins (excluding cefoxitin), cefpodoxime, all antibiotics of the ML group (macrolides and lincosamides), sulfamethoxazole, glycopeptides, fosfomycin, and fusidic acid, naturally sensitive to aminoglycosides, piperacillin, mezlocillin, ticarcillin, third and fourth generation cephalosporins, carbapenems, aztreonam, quinolones, trimethoprim, cotrimoxazole, and chloramphenicol. M. morganii is naturally resistant to a wide range of antibiotics. The natural resistance pattern is useful for validation of sensitivity tests. Susceptibility to antibiotics is an unsuitable parameter for the discrimination of the described subspecific taxa of M. morganii. M. morganii strains that do not belong to Biovar A are rare.
Hiroyuki Sawada - One of the best experts on this subject based on the ideXlab platform.
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draft genome sequences of 10 strains of pseudomonas syringae pv actinidiae Biovar 1 a major kiwifruit bacterial canker pathogen in japan
Microbiology Resource Announcements, 2020Co-Authors: Takashi Fujikawa, Hiroe Hatomi, Hiroyuki SawadaAbstract:Several groups (Biovars) of the kiwifruit bacterial canker pathogen Pseudomonas syringae pv. actinidiae are found in Japan. Here, we sequenced and compared 10 genome sequences of Biovar 1, a major group in Japan, which is known as the phaseolotoxin producer.
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draft genome sequences of 10 strains of pseudomonas syringae pv actinidiae Biovar 1 a major kiwifruit bacterial canker pathogen in japan
bioRxiv, 2020Co-Authors: Takashi Fujikawa, Hiroe Hatomi, Hiroyuki SawadaAbstract:Several groups (Biovars) of the kiwifruit bacterial canker pathogen, Pseudomonas syringae pv. actinidiae, are found in Japan. Here, we sequenced and compared the 10 genomes of Biovar 1, the major group in Japan, which is known as the phaseolotoxin producer. The kiwifruit bacterial canker pathogen, Pseudomonas syringae pv. actinidiae (Psa), was first described in Japan in 1989 (1). Subsequently, Psa was found in other kiwifruit-producing countries (2). Based on comparative analyses (2-4), Psa was categorized into several groups (Biovars). The first Japanese group was named Biovar 1 (Psa1), which was also later found in Italy and Korea. This Biovar produces phaseolotoxin (2), a phytotoxin that inhibits arginine biosynthesis in host plants and results in bacterial canker symptom development. On the Psa1 chromosome, a large number of genes involved in phaseolotoxin biosynthesis are accumulated in an approximately 23 kb region (argK-tox cluster), which is contained in an exogenous genomic island (tox island) that Psa1 acquired in the past (2). However, some Psa1 strains found in Ehime Prefecture, Japan (the Ehime isolates) do not produce phaseolotoxin, although they seem to possess the argK-tox cluster (5). On the other hand, several Psa1 strains preserved in the NARO Genebank (https://www.gene.affrc.go.jp/index_en.php) may lack this cluster (2). Here, we selected 10 strains (Table 1) that represent Psa1 diversity and conducted comparative genome analyses. O_TBL View this table: org.highwire.dtl.DTLVardef@f2cdbdorg.highwire.dtl.DTLVardef@a16c33org.highwire.dtl.DTLVardef@1c68baborg.highwire.dtl.DTLVardef@1fbb077org.highwire.dtl.DTLVardef@fe901e_HPS_FORMAT_FIGEXP M_TBL O_FLOATNOTable 1.C_FLOATNO O_TABLECAPTIONGenome data and accession numbers of 10 strains of Pseudomonas syringae pv. actinidiae Biovar 1. C_TABLECAPTION C_TBL
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Genome analysis of Pseudomonas syringae pv. actinidiae Biovar 6, which produces the phytotoxins, phaseolotoxin and coronatine
Nature Publishing Group, 2019Co-Authors: Takashi Fujikawa, Hiroyuki SawadaAbstract:Abstract The kiwifruit bacterial canker pathogen, Pseudomonas syringae pv. actinidiae (Psa), causes enormous economic damages in many kiwifruit producing countries. In 2015, Biovar 6, the novel Biovar of Psa, was found in Nagano Prefecture, Japan. The genomes of two representative strains of Biovar 6 (MAFF 212134 and MAFF 212141) were sequenced and analysed, indicating that their genomes are the most similar to that of Biovar 3 among the known Psa Biovars, based on average nucleotide identity analysis. Biovar 3 has neither the phaseolotoxin synthesis gene cluster nor the coronatine synthesis gene cluster, whereas Biovar 6 has both clusters and produces both phytotoxins. We found that Biovar 6 possesses 29 type III secreted effector (T3SE) genes, among which avrRps4 and hopBI1 are unique to Biovar 6. The expression of T3SE genes and two phytotoxin synthesis gene clusters of Biovar 6 during the early stages of host infection was investigated using RNA-Seq analysis, showing that these genes could be grouped into three categories: constantly expressed genes, constantly suppressed genes, and temporarily induced genes. A PCR assay was established to differentiate Biovar 6 strains from the other Psa Biovars and the closely related pathovar, pv. actinidifoliorum, by using avrRps4 as a Biovar 6-specific marker gene
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Genome analysis of the kiwifruit canker pathogen Pseudomonas syringae pv. actinidiae Biovar 5.
Scientific reports, 2016Co-Authors: Takashi Fujikawa, Hiroyuki SawadaAbstract:Pseudomonas syringae pv. actinidiae (Psa) is a destructive pathogen of kiwifruit bacterial canker disease, causing severe economic losses to kiwifruit industry worldwide. Biovar 5 is the most recently reported Biovar of Psa and is found in only a local area of Japan at present. There is not much information of genetic characteristics of Biovar 5. Thus, the genome of Biovar 5 was sequenced and analyzed to clarify its detailed genetic characteristics. Here, the genomes of strain MAFF 212056 and MAFF 212061 of Biovar 5 were estimated to be about 6.3 Mbp and 6.5 Mbp, respectively and their phylogenetic positions were proved to be near that of Biovar 2 in the phylogenetic tree. However, it was confirmed that Biovar 5 had neither the coronatine biosynthetic genes conserved in Biovar 2, its phylogenetic neighbor, nor the phaseolotoxin biosynthetic genes conserved in Biovar 1, Japanese native pathogen. In addition, 45 genes of type III secreted effectors were identified in Biovar 5 genomes, showing that their composition is different from that in the other Biovars. Moreover, some Biovar 5-specific regions were identified. Then, Biovar 5-specific PCR primers for targeting these regions were designed and proved to be applicable for detecting Biovar 5 specifically.
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construction of physical map and mapping of chromosomal virulence genes of the Biovar 3 agrobacterium rhizobium vitis strain k ag 1
Genes & Genetic Systems, 2006Co-Authors: Katsuyuki Tanaka, Hiroyuki Sawada, Henryk Urbanczyk, Hiroki Matsui, Katsunori SuzukiAbstract:Most plant pathogenic Agrobacterium strains have been classified into three Biovars, “Biovar 1 (A. tumefaciens; Rhizobium radiobacter), Biovar 2 (A. rhizogenes; R. rhizogenes) and Biovar 3 (A. vitis; R. vitis)”. The bacteria possess diverse types of genomic organization depending on the Biovar. Previous genomic physical maps indicated difference in location of rDNA and chromosomally-coded virulence genes between Biovar 1 and 2 genomes. In order to understand Biovar 3 genome and its evolution in relation to the Biovar 1, 2 and 3 genomes, we constructed physical map of a pathogenic Biovar 3 strain K-Ag-1 in this study. Its genome consisted of two circular chromosomes (3.6 and 1.1 Mbp in length), and three plasmids (560, 230 and 70 kbp). Gene mapping based on the physical map showed presence of two rDNA loci in the larger chromosome and at least one rDNA locus in the smaller chromosome. Six chromosomal virulence genes, namely chvA, chvD, chvE, glgP, exoC and ros were found in the larger chromosome and not in the smaller chromosome. The location of rDNA loci is similar with that of Biovar 1 genome, whereas the location of chromosomal virulence genes is similar with that of Biovar 2 genome despite of the closer 16S-rRNA based phylogenetic relation of Biovar 3 with Biovar 1 than with Biovar 2. Genomic PFGE RFLP analysis revealed that the K-Ag-1 strain, which was isolated on a kiwifruit plant in Japan, has the closest intra-species relation with two strains isolated from grapevine plants in Japan among eight Biovar 3 strains examined. This datum suggests that the line of the strain is a major one in Biovar 3 in Japan. Evolution of the genome of the strain is discussed based on the data.
Hai Jiang - One of the best experts on this subject based on the ideXlab platform.
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typing discrepancy between phenotypic and molecular characterization revealing an emerging Biovar 9 variant of smooth phage resistant b abortus strain 8416 in china
Frontiers in Microbiology, 2015Co-Authors: Hai Jiang, Guozhong Tian, Yaoxia Kang, Dongri Piao, Enhou Jia, Liang Lin, Buyun Cui, Yungfu Chang, Xiaokui GuoAbstract:A newly isolated smooth colony morphology phage-resistant (SPR) strain 8416 isolated from a 45-year-old cattle farm cleaner with clinical features of brucellosis in China was reported. The most unusual phenotype was its resistance to two Brucella phages Tbilisi and Weybridge, but sensitive to Berkeley 2, a pattern similar to that of B. melitensis Biovar 1. VITEK 2 biochemical identification system found that both strain 8416 and B. melitensis strains shared positive ILATk, but negative in other B. abortus strains. However, routine biochemical and phenotypic characteristics of strain 8416 were most similar to that of B. abortus Biovar 9 except CO2 requirement. In addition, multiple PCR molecular typing assays including AMOS-PCR, B. abortus special PCR (B-ab PCR) and a novel sub-Biovar typing PCR, indicated that strain 8416 may belong to either Biovar 3b or 9 of B. abortus. Surprisingly, further MLVA typing results showed that strain 8416 was most closely related to B. abortus Biovar 3 in the Brucella MLVA database, primarily differing in 4 out of 16 screened loci. Therefore, due to the unusual discrepancy between phenotypic (biochemical reactions and particular phage lysis profile) and molecular typing characteristics, strain 8416 couldn’t be exactly classified to any of the existing B. abortus Biovars and might be a new variant of B. abortus Biovar 9. The present study also indicates that the present phage typing scheme for Brucella spp. is subject to variation and the routine Brucella Biovar typing needs further studies.
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mlva genotyping of brucella melitensis and brucella abortus isolates from different animal species and humans and identification of brucella suis vaccine strain s2 from cattle in china
PLOS ONE, 2013Co-Authors: Hai Jiang, Heng Wang, Pei Xiao, Guozhong Tian, Liqing Xu, Guiying Hu, Dongdong Di, Jingchuan Mi, Ruiping Yu, Litao SongAbstract:In China, brucellosis is an endemic disease and the main sources of brucellosis in animals and humans are infected sheep, cattle and swine. Brucella melitensis (Biovars 1 and 3) is the predominant species, associated with sporadic cases and outbreak in humans. Isolates of B. abortus, primarily Biovars 1 and 3, and B. suis Biovars 1 and 3 are also associated with sporadic human brucellosis. In this study, the genetic profiles of B. melitensis and B. abortus isolates from humans and animals were analyzed and compared by multi-locus variable-number tandem-repeat analysis (MLVA). Among the B. melitensis isolates, the majority (74/82) belonged to MLVA8 genotype 42, clustering in the ‘East Mediterranean’ group. Two B. melitensis Biovar 1 genotype 47 isolates, belonging to the ‘Americas’ group, were recovered; both were from the Himalayan blue sheep (Pseudois nayaur, a wild animal). The majority of B. abortus isolates (51/70) were Biovar 3, genotype 36. Ten B. suis Biovar 1 field isolates, including seven outbreak isolates recovered from a cattle farm in Inner Mongolia, were genetically indistinguishable from the vaccine strain S2, based on MLVA cluster analysis. MLVA analysis provided important information for epidemiological trace-back. To the best of our knowledge, this is the first report to associate Brucella cross-infection with the vaccine strain S2 based on molecular comparison of recovered isolates to the vaccine strain. MLVA typing could be an essential assay to improve brucellosis surveillance and control programs.
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MLVA Genotyping of Brucella melitensis and Brucella abortus Isolates from Different Animal Species and Humans and Identification of Brucella suis Vaccine Strain S2 from Cattle in China. PLoS One 8: e76332
2013Co-Authors: Hai Jiang, Heng Wang, Pei Xiao, Weixing Fan, Guozhong Tian, Mengguang FanAbstract:In China, brucellosis is an endemic disease and the main sources of brucellosis in animals and humans are infected sheep, cattle and swine. Brucella melitensis (Biovars 1 and 3) is the predominant species, associated with sporadic cases and outbreak in humans. Isolates of B. abortus, primarily Biovars 1 and 3, and B. suis Biovars 1 and 3 are also associated with sporadic human brucellosis. In this study, the genetic profiles of B. melitensis and B. abortus isolates from humans and animals were analyzed and compared by multi-locus variable-number tandem-repeat analysis (MLVA). Among the B. melitensis isolates, the majority (74/82) belonged to MLVA8 genotype 42, clustering in the ‘East Mediterranean ’ group. Two B. melitensis Biovar 1 genotype 47 isolates, belonging to the ‘Americas ’ group, were recovered; both were from the Himalayan blue sheep (Pseudois nayaur, a wild animal). The majority of B. abortus isolates (51/70) were Biovar 3, genotype 36. Ten B. suis Biovar 1 field isolates, including seven outbreak isolates recovered from a cattle farm in Inner Mongolia, were genetically indistinguishable from the vaccine strain S2, based on MLVA cluster analysis. MLVA analysis provided important information for epidemiological trace-back. To the bes