Detection of pigs epidemic diarrhea virus (PEDV) was conducted on 331 piglets diarrhea fecal samples collected in Nanning, Yulin and other 12 areas of Guangxi Province from January of 2011 to April of 2014 by the me...Detection of pigs epidemic diarrhea virus (PEDV) was conducted on 331 piglets diarrhea fecal samples collected in Nanning, Yulin and other 12 areas of Guangxi Province from January of 2011 to April of 2014 by the method of reverse transcription-polymerase chain reaction (RT-PCR). The results showed that the positive samples of PEDV were 210 and the positive rate was 63.44%. The clone and sequencing of M gene was carried out on 25 positive samples. PEDV reference strains were selected from GeneBank to conduct the sequence homology alignment analysis and the phylogenetic tree of M gene. The M gene homology and amino acid sequence identity between 25 isolated strains and 51 reference strains were 96.0% - 99.6% and 94.3% - 99.6%, respectively. The genetic variation anal- ysis of M gene showed that the genetic relationship of PEDV prevalent strains in Guangxi Province from 2013 to 2014 was close to that of the prevalent strains in Bei- jing, Anhui, Wuhan, Hebei and Guangdong from 2010 to 2013, and which were far from that of the Chinese early isolates CH/S (GenBank number: JN547228 ), vaccine strain CV777 (GenBank number: AF353511 ) and Attenuated DR13 (GenBank number: JQ023162). Indicating that the PEDV strains prevalent in Guan- gxi in recent years showed significant variation with the early isolates.展开更多
In the present study, FBL3 murine erythroleukemia cells were transfected with human OSM(hOSM) gene by recombinant adenovirus, then the immunological properties of hOSM genetransfected FBL3 cells(FBL3OSM+) were investi...In the present study, FBL3 murine erythroleukemia cells were transfected with human OSM(hOSM) gene by recombinant adenovirus, then the immunological properties of hOSM genetransfected FBL3 cells(FBL3OSM+) were investigated. 4 hours after transfection with hOSM gene, hOSM could be detected in the supernatant of FBL3OSM+ cells and hOSM secretion peaked at 24 h. The proliferation of FBL3OSM+ cells was inhibited markedly. The clonal formation of FBL3OSM+ cells was suppressed more obviously in comparison with wildtype FBL3 cells when analysed in clonal argar culture. Flow cytometry analysis showed that FBL3OSM+ cells expressed higher levels of Fas protein, B7 and ICAM1 molecules.FBL3OSM+ cells also expressed higher level of MHC class I molecules(H2Kb) but remained unchanged in expression of MHC class II molecules (Ia). CD14, which is a specific marker of monocyte/macrophage and not expressed on the wildtype FBL3 cells, was also detected on the surface of FBL3OSM+ cells. The results suggested that OSM gene transfer could increase the immunogenicity of FBL3 cells and promote their differentiation into macrophagelike cells. The data outline a promising approach to OSM gene therapy of leukemia mediated by recombinant adenovirus.展开更多
为了给深入研究猪繁殖与呼吸综合征病毒(porcine reproductive and respiratory syndromevirus,PRRSV)ORF6基因编码的M蛋白的生物学功能提供重要试验材料,本研究首先利用慢病毒包装系统构建了过表达PRRSVORF6基因的重组慢病毒质粒,将该...为了给深入研究猪繁殖与呼吸综合征病毒(porcine reproductive and respiratory syndromevirus,PRRSV)ORF6基因编码的M蛋白的生物学功能提供重要试验材料,本研究首先利用慢病毒包装系统构建了过表达PRRSVORF6基因的重组慢病毒质粒,将该质粒连同辅助质粒共同转染至HEK293T细胞获得重组慢病毒;之后将重组慢病毒感染MARC-145细胞,利用嘌呤霉素结合有限稀释法进行筛选,连续筛选3轮后建立了稳定表达PRRSVM蛋白的MARC-145ORF6细胞系;并使用CCK-8试验评估过表达PRRSVM蛋白对MARC-145细胞生长的影响。利用RT-PCR、蛋白免疫印迹(Westernblot)和间接免疫荧光(IFA)评估MARC-145ORF6细胞系的传代稳定性并鉴定M蛋白的亚细胞定位,进一步利用RT-qPCR评估过表达M蛋白对MARC-145细胞的干扰素及相关调节基因的影响;此外,还测定了PRRSV在MARC-145ORF6细胞系、MARC-145Flag细胞系和MARC-145细胞中的病毒滴度并绘制多步生长曲线以比较其差异。CCK-8试验结果表明,过表达PRRSVM蛋白对MARC-145细胞活力无显著影响;RT-qPCR、Westernblot和IFA等试验结果表明,MARC-145ORF6细胞系能够表达PRRSV的M蛋白且在传代过程中稳定。此外,稳定表达PRRSVM蛋白显著下调了细胞系的Ⅰ型干扰素及其相关调节基因;多步生长曲线表明,MARC-145ORF6细胞系促进PRRSV增殖,提高其病毒滴度。综上,本研究构建了可以稳定表达PRRSVM蛋白的MARC-145ORF6细胞系,发现其Ⅰ型干扰素水平显著下调且促进PRRSV复制。本研究构建的MARC-145ORF6细胞系将为M蛋白功能的深入研究提供重要生物材料。展开更多
This study was conducted to assess the occurrence and nature of extended-spectrum beta lactamase (ESBL) producing <em>Escherichia coli</em> and <em>Klebsiella pneumoniae</em> isolates from pati...This study was conducted to assess the occurrence and nature of extended-spectrum beta lactamase (ESBL) producing <em>Escherichia coli</em> and <em>Klebsiella pneumoniae</em> isolates from patients who presented with urinary tract infection at Federal Teaching Hospital Gombe. Isolates collected were recovered on MacConkey agar at 35<span style="white-space:nowrap;">°</span>C and were identified as members of Enterobacteriaceae, and further screened for antimicrobial susceptibility and resistance by disc diffusion method. Isolates resistant to oxyimino-cephalosporins were confirmed as ESBL producers using Double Disks Synergy Test (DDST). The study shows 66% resistance to ceftriaxone (30 μg) in <em>K. pneumoniae</em>, which was the highest value recorded and a 51% resistance to cefpodoxime (10 <em>μ</em>g) in <em>E. coli</em>. The sensitivity of <em>E. coli </em>and <em>K. pneumoniae</em> isolates to cefpodoxime (10 <em>μ</em>g) were 49% and 33.9% respectively. ESBLs were detected among 40% (40/100) of <em>E. coli</em> and 54.13% (59/109) of <em>K. pneumoniae</em> isolates. Molecular characterization of ESBL encoding genes among <em>E. coli</em> isolates using multiplex-PCR showed 10% prevalence of SHV gene and 5% prevalence for CTX-M gene while TEM gene was not detected. In <em>K. pneumoniae</em> isolates, 5% prevalence was recorded for each of the three genes screened. The study revealed a co-occurrence of SHV and CTX-M in 75% of the <em>E. coli</em> and 70% of the <em>K. pneumoniae</em> isolates;the occurrence of all the three genes was seen in 10% and 5% of <em>K. pneumoniae</em> and <em>E. coli</em> respectively. Multiplex-PCR method provided an efficient and rapid detection of ESBL related genes, hence could be used in epidemiological studies among ESBL isolates. Monitoring dissemination and transmissions of ESBL producers are highly recommended for optimum patient care and preventing the spread of multidrug resistant (MDR) pathogens.展开更多
[Objective] The aim of the study is to construct cDNA library of midgut tissue of wild silkworm and isolate the serine protease gene. [Method] The midgut tissue-specific cDNA library of wild silkworm was constructed v...[Objective] The aim of the study is to construct cDNA library of midgut tissue of wild silkworm and isolate the serine protease gene. [Method] The midgut tissue-specific cDNA library of wild silkworm was constructed via cDNA Library Construction Kit (TaKaRa), then the serine protease gene was cloned via sequencing of the yielded cDNA library. [Result] The titer of cDNA library reached 6.2×105 pfu/ml, average insert size was about 1.2 kb. The serine protease gene cDNA fragment was obtained from colony sequencing (Accession No: EU672968). The nucleotide sequence of the cloned 854 bp fragment encodes 284 amino acid residues. Homology analyses showed some homology between putative amino acid sequence of the cloned fragment and amino acid sequences of serine proteases from other ten insects. [Conclusion] The results may avail to reveal the resistance of silkworm and wild silkworm to exotic intrusion.展开更多
Endothelial PAS domain protein 1 gene (EPAS1) is a key transcription factor that activates the expression of oxygen-regu- lated genes. In this study, in order to better understand the effects of EPAS1 gene on hemato...Endothelial PAS domain protein 1 gene (EPAS1) is a key transcription factor that activates the expression of oxygen-regu- lated genes. In this study, in order to better understand the effects of EPAS1 gene on hematologic parameters in yak, we firstly quantified the tissue expression patterns for EPASl mRNA of yak, identified polymorphism in this gene and evaluated its association with hematologic parameters. Expression of EPAS1 mRNA was detected in all eight tissues (heart, liver, lung, spleen, pancreas, kidney, muscles and ovary). The expressions of EPAS1 in lung and pancreas were extremely higher than other tissues examined. Three novel single nucleotide polymorphisms (SNPs) (g.83052 C〉T, g.83065 G〉A and g.83067 C〉A) within the EPAS1 were identified and genotyped in Pali (PL), Gannan (GN) and Tianzhu White (TZW) yak breeds. Significant higher frequencies of the AA and GA genotypes and A allele of the g.83065 G〉A were observed in the PL and GN breeds than that in the TZW breed (P〈0.01). Association analysis of the PL breed indicated that the g.83065 G〉A polymorphism was significantly associated with hemoglobin (HGB) concentration in yaks (P〈0.05). Individuals with genotype AA had significantly higher HGB concentration (P〈0.05) than those with genotype GA and GG. All these results will help our further understanding of biological functional of yak EPAS1 gene in responding to hypoxia and also indicate EPAS1 might contribute to the hypoxia adaptation of the yak.展开更多
The full-length Mlo gene was obtained by reverse transcription polymerase chain reaction (RT-PCR) and RACE. The result of sequence analysis indicated that M/o gene from Pericallis hybrida B. Nord. contained about 12...The full-length Mlo gene was obtained by reverse transcription polymerase chain reaction (RT-PCR) and RACE. The result of sequence analysis indicated that M/o gene from Pericallis hybrida B. Nord. contained about 1296bp open reading frame and encoded 431 amino acids. According to the comparison of the exogenous gene sequences by BLAST analysis and phylogenetic analysis, Mlo gene shared over 85% nucleotide homology and 98% amino acid homology. Finally, through semi-quantitative-PCR and fluorescence quantitative analysis, we found that Mlo gene showed the highest expression levels in leaves and the lowest in roots after inoculated with powdery mildew pathogen for different days.展开更多
Bovine Respiratory Disease (BRD) causes a severe form of pneumonia in all age of cattle. This study was designed to investigate the distribution of capsular types, serotypes, and virulence-associated genes of the majo...Bovine Respiratory Disease (BRD) causes a severe form of pneumonia in all age of cattle. This study was designed to investigate the distribution of capsular types, serotypes, and virulence-associated genes of the major bacterial pathogens from BRD outbreak samples in Ethiopia. In this study 166 samples were collected from clinically sick (<i>n</i> = 107) and pneumonic lung tissue (<i>n</i> = 59). Laboratory assay confirmed isolation of <i>M. haemolytica</i> 37 (22.29%), <i>P. multocida</i> 25 (15.06%), <i>B. trehalosi</i> 12 (7.23%), and <i>H. somni</i> 15 (9.04%). PCR assay of <i>P. multocida</i> capsular typing revealed 21 (84.0%) cap A (<i>hyaD-hyaC</i>) and 4 (16.0%) cap D (<i>dcbF</i>) strains. <i>M. haemolytica</i> serotypes belonged to A: 1, A: 2, and A: 6 from 26 (70.27%), 4 (10.81%), and 7 (18.92%) isolates, respectively. <i>P. multocida</i> biotyping showed isolation of A: 1, A: 2, and A: 3 from 3 (14.29%), 2 (9.52%), and 16 (76.19%) isolates, respectively. <i>M. haemolytica</i> harbored more than 60% <i>ssa</i> gene, and 90.91% <i>sodA</i> while <i>FbpA</i>, <i>TbpA</i>, and <i>lktC</i> genes were found in all isolates. Likewise, all <i>P. multocida</i> exhibited <i>toxA</i>, <i>FbpA</i>, <i>TbpA</i>, and <i>pmSLP</i> genes. The current finding showed that <i>M. haemolytica</i> serotype A: 1 is frequently associated with BRD followed by <i>P. multocida</i> biotype A: 3. These two isolates harbored diverse virulence-associated genes and presented the pathogenic potential of the current isolates. Thus, investigation of pathogenic strains of BRD, virulence genes distribution, and molecular epidemiology of the disease from wider areas of the country are essential. Hence, continuous outbreak surveillance and molecular approaches are indispensable in designing efficient prevention strategies.展开更多
基金Supported by Scientific Research Project of Guangxi Bureau of Animal Husbandry&Veterinary Medicine(12049031)Systemic Research Subject of Guangxi Key Laboratory of Animal Vaccines and New Technology(12-071-28-A-5)Guangxi Basal Research Specific Fund(14-2)
文摘Detection of pigs epidemic diarrhea virus (PEDV) was conducted on 331 piglets diarrhea fecal samples collected in Nanning, Yulin and other 12 areas of Guangxi Province from January of 2011 to April of 2014 by the method of reverse transcription-polymerase chain reaction (RT-PCR). The results showed that the positive samples of PEDV were 210 and the positive rate was 63.44%. The clone and sequencing of M gene was carried out on 25 positive samples. PEDV reference strains were selected from GeneBank to conduct the sequence homology alignment analysis and the phylogenetic tree of M gene. The M gene homology and amino acid sequence identity between 25 isolated strains and 51 reference strains were 96.0% - 99.6% and 94.3% - 99.6%, respectively. The genetic variation anal- ysis of M gene showed that the genetic relationship of PEDV prevalent strains in Guangxi Province from 2013 to 2014 was close to that of the prevalent strains in Bei- jing, Anhui, Wuhan, Hebei and Guangdong from 2010 to 2013, and which were far from that of the Chinese early isolates CH/S (GenBank number: JN547228 ), vaccine strain CV777 (GenBank number: AF353511 ) and Attenuated DR13 (GenBank number: JQ023162). Indicating that the PEDV strains prevalent in Guan- gxi in recent years showed significant variation with the early isolates.
文摘In the present study, FBL3 murine erythroleukemia cells were transfected with human OSM(hOSM) gene by recombinant adenovirus, then the immunological properties of hOSM genetransfected FBL3 cells(FBL3OSM+) were investigated. 4 hours after transfection with hOSM gene, hOSM could be detected in the supernatant of FBL3OSM+ cells and hOSM secretion peaked at 24 h. The proliferation of FBL3OSM+ cells was inhibited markedly. The clonal formation of FBL3OSM+ cells was suppressed more obviously in comparison with wildtype FBL3 cells when analysed in clonal argar culture. Flow cytometry analysis showed that FBL3OSM+ cells expressed higher levels of Fas protein, B7 and ICAM1 molecules.FBL3OSM+ cells also expressed higher level of MHC class I molecules(H2Kb) but remained unchanged in expression of MHC class II molecules (Ia). CD14, which is a specific marker of monocyte/macrophage and not expressed on the wildtype FBL3 cells, was also detected on the surface of FBL3OSM+ cells. The results suggested that OSM gene transfer could increase the immunogenicity of FBL3 cells and promote their differentiation into macrophagelike cells. The data outline a promising approach to OSM gene therapy of leukemia mediated by recombinant adenovirus.
文摘为了给深入研究猪繁殖与呼吸综合征病毒(porcine reproductive and respiratory syndromevirus,PRRSV)ORF6基因编码的M蛋白的生物学功能提供重要试验材料,本研究首先利用慢病毒包装系统构建了过表达PRRSVORF6基因的重组慢病毒质粒,将该质粒连同辅助质粒共同转染至HEK293T细胞获得重组慢病毒;之后将重组慢病毒感染MARC-145细胞,利用嘌呤霉素结合有限稀释法进行筛选,连续筛选3轮后建立了稳定表达PRRSVM蛋白的MARC-145ORF6细胞系;并使用CCK-8试验评估过表达PRRSVM蛋白对MARC-145细胞生长的影响。利用RT-PCR、蛋白免疫印迹(Westernblot)和间接免疫荧光(IFA)评估MARC-145ORF6细胞系的传代稳定性并鉴定M蛋白的亚细胞定位,进一步利用RT-qPCR评估过表达M蛋白对MARC-145细胞的干扰素及相关调节基因的影响;此外,还测定了PRRSV在MARC-145ORF6细胞系、MARC-145Flag细胞系和MARC-145细胞中的病毒滴度并绘制多步生长曲线以比较其差异。CCK-8试验结果表明,过表达PRRSVM蛋白对MARC-145细胞活力无显著影响;RT-qPCR、Westernblot和IFA等试验结果表明,MARC-145ORF6细胞系能够表达PRRSV的M蛋白且在传代过程中稳定。此外,稳定表达PRRSVM蛋白显著下调了细胞系的Ⅰ型干扰素及其相关调节基因;多步生长曲线表明,MARC-145ORF6细胞系促进PRRSV增殖,提高其病毒滴度。综上,本研究构建了可以稳定表达PRRSVM蛋白的MARC-145ORF6细胞系,发现其Ⅰ型干扰素水平显著下调且促进PRRSV复制。本研究构建的MARC-145ORF6细胞系将为M蛋白功能的深入研究提供重要生物材料。
文摘This study was conducted to assess the occurrence and nature of extended-spectrum beta lactamase (ESBL) producing <em>Escherichia coli</em> and <em>Klebsiella pneumoniae</em> isolates from patients who presented with urinary tract infection at Federal Teaching Hospital Gombe. Isolates collected were recovered on MacConkey agar at 35<span style="white-space:nowrap;">°</span>C and were identified as members of Enterobacteriaceae, and further screened for antimicrobial susceptibility and resistance by disc diffusion method. Isolates resistant to oxyimino-cephalosporins were confirmed as ESBL producers using Double Disks Synergy Test (DDST). The study shows 66% resistance to ceftriaxone (30 μg) in <em>K. pneumoniae</em>, which was the highest value recorded and a 51% resistance to cefpodoxime (10 <em>μ</em>g) in <em>E. coli</em>. The sensitivity of <em>E. coli </em>and <em>K. pneumoniae</em> isolates to cefpodoxime (10 <em>μ</em>g) were 49% and 33.9% respectively. ESBLs were detected among 40% (40/100) of <em>E. coli</em> and 54.13% (59/109) of <em>K. pneumoniae</em> isolates. Molecular characterization of ESBL encoding genes among <em>E. coli</em> isolates using multiplex-PCR showed 10% prevalence of SHV gene and 5% prevalence for CTX-M gene while TEM gene was not detected. In <em>K. pneumoniae</em> isolates, 5% prevalence was recorded for each of the three genes screened. The study revealed a co-occurrence of SHV and CTX-M in 75% of the <em>E. coli</em> and 70% of the <em>K. pneumoniae</em> isolates;the occurrence of all the three genes was seen in 10% and 5% of <em>K. pneumoniae</em> and <em>E. coli</em> respectively. Multiplex-PCR method provided an efficient and rapid detection of ESBL related genes, hence could be used in epidemiological studies among ESBL isolates. Monitoring dissemination and transmissions of ESBL producers are highly recommended for optimum patient care and preventing the spread of multidrug resistant (MDR) pathogens.
文摘[Objective] The aim of the study is to construct cDNA library of midgut tissue of wild silkworm and isolate the serine protease gene. [Method] The midgut tissue-specific cDNA library of wild silkworm was constructed via cDNA Library Construction Kit (TaKaRa), then the serine protease gene was cloned via sequencing of the yielded cDNA library. [Result] The titer of cDNA library reached 6.2×105 pfu/ml, average insert size was about 1.2 kb. The serine protease gene cDNA fragment was obtained from colony sequencing (Accession No: EU672968). The nucleotide sequence of the cloned 854 bp fragment encodes 284 amino acid residues. Homology analyses showed some homology between putative amino acid sequence of the cloned fragment and amino acid sequences of serine proteases from other ten insects. [Conclusion] The results may avail to reveal the resistance of silkworm and wild silkworm to exotic intrusion.
基金supported by the Special Fund for Agro-scientific Research in the Public Interest,China (201003061)the Key Technologies R&D Program of China during the 12thFive-Year Plan period (2012BAD13B05)+1 种基金the Great Project of Science and Technology of Gansu Province in China (1102NKDA027)the National Natural Science Foundation of China (31101702)
文摘Endothelial PAS domain protein 1 gene (EPAS1) is a key transcription factor that activates the expression of oxygen-regu- lated genes. In this study, in order to better understand the effects of EPAS1 gene on hematologic parameters in yak, we firstly quantified the tissue expression patterns for EPASl mRNA of yak, identified polymorphism in this gene and evaluated its association with hematologic parameters. Expression of EPAS1 mRNA was detected in all eight tissues (heart, liver, lung, spleen, pancreas, kidney, muscles and ovary). The expressions of EPAS1 in lung and pancreas were extremely higher than other tissues examined. Three novel single nucleotide polymorphisms (SNPs) (g.83052 C〉T, g.83065 G〉A and g.83067 C〉A) within the EPAS1 were identified and genotyped in Pali (PL), Gannan (GN) and Tianzhu White (TZW) yak breeds. Significant higher frequencies of the AA and GA genotypes and A allele of the g.83065 G〉A were observed in the PL and GN breeds than that in the TZW breed (P〈0.01). Association analysis of the PL breed indicated that the g.83065 G〉A polymorphism was significantly associated with hemoglobin (HGB) concentration in yaks (P〈0.05). Individuals with genotype AA had significantly higher HGB concentration (P〈0.05) than those with genotype GA and GG. All these results will help our further understanding of biological functional of yak EPAS1 gene in responding to hypoxia and also indicate EPAS1 might contribute to the hypoxia adaptation of the yak.
基金Supported by Postdoctoral Scientifi c Research Foundation of Heilongjiang Province(LBH-Q10144)the Natural Science Foundation of Heilongjiang Province(C201112)Northeast Agricultural University Doctoral Research Fund(200830)
文摘The full-length Mlo gene was obtained by reverse transcription polymerase chain reaction (RT-PCR) and RACE. The result of sequence analysis indicated that M/o gene from Pericallis hybrida B. Nord. contained about 1296bp open reading frame and encoded 431 amino acids. According to the comparison of the exogenous gene sequences by BLAST analysis and phylogenetic analysis, Mlo gene shared over 85% nucleotide homology and 98% amino acid homology. Finally, through semi-quantitative-PCR and fluorescence quantitative analysis, we found that Mlo gene showed the highest expression levels in leaves and the lowest in roots after inoculated with powdery mildew pathogen for different days.
文摘Bovine Respiratory Disease (BRD) causes a severe form of pneumonia in all age of cattle. This study was designed to investigate the distribution of capsular types, serotypes, and virulence-associated genes of the major bacterial pathogens from BRD outbreak samples in Ethiopia. In this study 166 samples were collected from clinically sick (<i>n</i> = 107) and pneumonic lung tissue (<i>n</i> = 59). Laboratory assay confirmed isolation of <i>M. haemolytica</i> 37 (22.29%), <i>P. multocida</i> 25 (15.06%), <i>B. trehalosi</i> 12 (7.23%), and <i>H. somni</i> 15 (9.04%). PCR assay of <i>P. multocida</i> capsular typing revealed 21 (84.0%) cap A (<i>hyaD-hyaC</i>) and 4 (16.0%) cap D (<i>dcbF</i>) strains. <i>M. haemolytica</i> serotypes belonged to A: 1, A: 2, and A: 6 from 26 (70.27%), 4 (10.81%), and 7 (18.92%) isolates, respectively. <i>P. multocida</i> biotyping showed isolation of A: 1, A: 2, and A: 3 from 3 (14.29%), 2 (9.52%), and 16 (76.19%) isolates, respectively. <i>M. haemolytica</i> harbored more than 60% <i>ssa</i> gene, and 90.91% <i>sodA</i> while <i>FbpA</i>, <i>TbpA</i>, and <i>lktC</i> genes were found in all isolates. Likewise, all <i>P. multocida</i> exhibited <i>toxA</i>, <i>FbpA</i>, <i>TbpA</i>, and <i>pmSLP</i> genes. The current finding showed that <i>M. haemolytica</i> serotype A: 1 is frequently associated with BRD followed by <i>P. multocida</i> biotype A: 3. These two isolates harbored diverse virulence-associated genes and presented the pathogenic potential of the current isolates. Thus, investigation of pathogenic strains of BRD, virulence genes distribution, and molecular epidemiology of the disease from wider areas of the country are essential. Hence, continuous outbreak surveillance and molecular approaches are indispensable in designing efficient prevention strategies.