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Background: The porcine circovirus-like agent P1 is a newly discovered DNA virus with a single-stranded circular genome that is highly homologous to that of porcine circovirus type 2. P1 infection can cause symptoms resembling postweaning multisystemic wasting syndrome. This study aims to develop a rapid, sensitive and specific method to detect P1., Results: A pair of primers was designed and used to amplify a 119 bp DNA fragment to generate a recombinant plasmid which was served as the standard. A SYBR I qPCR protocol was established using the P1 recombinant plasmid standard and the sensitivity, specificity and stability of this method was analyzed. The results demonstrate a strong correlation with P1 recombinant plasmid titers when virus DNA copy numbers fall in between 10(0) ~ 10(9) copies/μL. This method doesn't detect pseudo rabies, porcine parvovirus or porcine reproductive and respiratory syndrome virus; moreover it can distinguish porcine circovirus type 2 from P1 by melting temperature analysis. Coefficient of variation for each batch of reaction is less than 5%. The serum virus titers of P1 positive in this study were measured by this protocol to be 10(3) to 10(7) copies/mL., Conclusions: The established qPCR is sensitive, specific, and reliable, which could be a useful tool when applied to quantification of P1 in a variety of samples from infected pigs.

Canine influenza virus (CIV) is an emerging pathogen that causes acute respiratory disease in dogs. The aim of this study was to investigate the pathogenicity of A/canine/Jiangsu/06/2010 (H3N2) virus isolated in China. Nine dogs were inoculated intranasally with 107.95 of 50% egg infectious dose (EID50) of the virus. The onset of clinical signs and virus shedding was observed on day 1 post-infection (p.i.). The peak clinical score occurred between days 4 and 6 p.i. The experimentally infected dogs were found to shed virus not only via the respiratory tract but also via the digestive tract. Viral RNA could be detected in multiple organs including the trachea, lung, liver, spleen, kidney, brain and duodenum. All the sampled organs from infected dogs showed significant lesions and viral antigen staining. The results differed from those reporting using previous CIV strains; the Chinese isolate could induce extrapulmonary infection and cause extensive lesions in dogs.

The objective of this study was to determine the association between phenotypic resistance, genotypic resistance and virulence genes of Escherichia coli isolates in Jiangsu province, China and Punjab province Pakistan. A total of 62 E. coli isolates were characterized for phenotypic resistance, genotypic resistance and virulence factor genes. The anti-microbial resistance phenotype and genotypes in relation to virulence factor genes were assessed by statistical analysis. Of 20 tested virulence genes, twelve were found and eight were not found in any isolates. sitA and TspE4C2 were the most prevalent virulence genes. Of the 13 anti-microbial agents tested, resistance to ampicillin, sulphonamide and tetracycline was the most frequent. All isolates were multiresistant, and 74% were resistant to trimethoprim and sulphamethaxazole. Phenotypically, tetracycline-, cefotaxime- and trimethoprim-resistant isolates had increased virulence factors as compared with susceptible isolates. Genotypically, resistant genes Tem, ctx-M, Tet, Sul 1, dhfr1, Cat2 and flo-R showed the association with the virulence genes. Almost all classes of anti-microbial-resistant genes have a high association with virulence. Resistant isolates have more virulent genes than the susceptible isolates., (© 2012 Blackwell Verlag GmbH.)

A canine influenza virus (CIV) strain of avian origin designated A/Canine/Jiangsu/06/2010 (H3N2) was isolated from dogs exhibiting severe respiratory disease in Jiangsu, China. We announce the complete genome sequence of this viral strain and report major findings from the genomic analysis. This sequence will help us understand the molecular characteristics and evolutionary of H3N2 CIV in China.

Serratia marcescens jn01 was employed as the host for the isolation of phages from environmental sewage. One strain of phage named SmPjn was purified by picking transparent plaque with 2mm diameter and clear edge on the double-layer agar repeatedly. Electron micrographs indicated that the phage head was icosahedral with head size and tail length of (58 +/- 2.16) x (55 +/- 0.47) nm and (7 +/- 1.25) nm, respectively. On the basis of the morphology, this phage belongs to the family Podoviridae. Host-range determination revealed that the phage was capable of infecting the other two isolates of S. marcescens, P25 and CMCC41002. The optimal multiplicity of infection was 1. A one-step growth curve of SmPjn indicated that the latent period and burst size were estimated at 50 min and 1,125 pfu/cell, respectively . Genomic DNA of SmPjn was above 27kb in size and could be digested by Hind Ill and EcoR I into 11 and 9 visible fragments after electrophoresis, respectively. A novel Podoviridae-phage infecting S. marcescens was firstly reported in China.

Aeromonas hydrophila is a gram-negative bacterium that can infect a variety of aquatic and terrestrial animals. It is essential to develop a vaccine to reduce the economic losses caused by this bacterium in aquaculture worldwide. Here, an immunoproteomic assay was used to identify the immunogenic extracellular proteins of the Chinese vaccine strain J-1. Ten unique immunogenic proteins were identified from the two-dimensional electrophoresis immunoblot profiles by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) or MALDI-TOF-TOF-MS. One protein of interest, Omp38, was detected by antisera on two-dimensional immunoblots, suggesting that it might be located both extracellularly and in the membrane. In exploring the potential of Omp38 as a vaccine candidate in fish, we found the omp38 gene to be prevalent by PCR among different (36/48) A. hydrophila isolates. The recombinant Omp38 induced a strong antibody response in rabbits, and the polyclonal antibody could recognize a band of approximately 38 kDa in the immunoblots of outer membrane protein extracts from most (24/40) of the A. hydrophila strains, including different predominant serotypes in China. These results indicated that the outer membrane antigen identified in this study could be developed as a vaccine candidate to induce protective immunity against A. hydrophila infection.

Three influenza H1N1 viruses were isolated in 2005 from pigs with respiratory disease on a farm in eastern China. The three isolates were characterized to determine their probable origin. Each of the eight genes of the isolates was most closely related to the corresponding gene from the classical swine H1N1 virus. Also, phylogenetic analysis further confirmed that each of the eight genes of the isolates was closely related to the classical swine H1N1 viruses, especially those isolated in China. The HA1 proteins of the three isolates were identical to that of A/Swine/Guangdong/ 1/01, a virus isolated in 2001 in China, even though three nucleotide differences were observed. These results further support the concept that swine can serve as a reservoir of genetically stable influenza viruses.

Objective: To determine the prevalence of Streptococcus suis and major pathogenic serotypes in middle part of Jiangsu province., Methods: Tonsillar specimens from 303 slaughtered pigs aged 6 to 8 months were investigated for the presence of Streptococcus suis and major pathogenic serotypes by polymerase chain reaction (PCR) method. Bacteriological examination compared with molecular genetics identification for three Streptococcus suis isolates were also done., Results: The overall carrier rate of Streptococcus suis was up to 88.0%, with the percentages of serotype 1(14), 2(1/2), 7 and 9 were 9.6%, 8.5%, 11.3% and 29.5% respectively in 2005. While in 2006, the prevalence of Streptococcus suis was 82.5%, with capsular types 1 (14), 2 (1/2), 7 and 9 were accounted for 17.6%, 2.4%, 25.8% and 20.0% of all the specimens. All the three isolates belonged to Streptococcus suis serotype 2,named 2a, 2f and 14e, which exhibiting the virulent phenotype cps2+/gdh+/mrp-/lepf-/sly-/fbps+/orf2+/89k-, cps2+/lgdh+/mrp-/epf-/sly-/fbps-/orf2-/89k- and cps2+/gdh+/mrp-/epf-/sly-/fbps/orf2-/ respectively. These isolates were all susceptible to amoxicillin, ampicillin, penicillin and resistant to amikacin and tetraycline. Clinical signs were not noted in BALB/c mice and rabbit., Conclusion: Prevalence of the Streptococcus suis among the healthy herds in the areas was very high, with various capsule types of Streptococcus suis involved in the same herds, and the virulent phenotype of these 3 isolates were very different from those prevalent Streptococcus suis serotype 2 virulent isolates frequently discovered from the epidemic areas.

Streptococcus suis type 2 (SS2) is a porcine zoonotic pathogen with worldwide distribution, and lacking suitable vaccine and virulent maker were bottleneck to control this infection. An immunoproteomic assay was used to identify antigenic proteins from the total extracellular proteins of the virulent Chinese SS2 strain ZY05719. The convalescent serum of a specific pathogen free (SPF) mini-pig recognized nine protein spots on PVDF membrane. Antigenic proteins on a duplicate gel, as well as those with a similar placement of extracellular proteins from another virulent strain (HA9801) and an avirulent strain (T15) on 2-D gels, were excised and identified by MALDI-TOF-MS. PMF of the protein spots were performed using the MASCOT server. Two proteins were found in all three strains. Comparative proteomic analysis between the two virulent strains and the avirulent strain revealed nine differential proteins, eight of which were successfully identified. Genes for six of the differentially expressed proteins were found in both virulent strains, and of those were present in the avirulent stain.

According to the conservative sequence in the epitaxial variable region of Thailand strain of WSSV published in GenBank,a pair of primers were designed to amplify the variable region genes of 5 local WSSV strains (ZHSH, ZHJ, HN, QD1, QD2) by PCR and then cloned. In accordance with the CN, the results indicated that the number of nucleotide of 5 strains were deleted more than 591bp of the TW and TH strains. The ZHSH and HN strains that deleted 591bp at the 3' end, and 454 bp at the 5' end of variable gene was highly homologous with CN strain about 99.3%. 229bp of ZHJ strain at the 5' end was homologous with CN about 99.3%, and deleted of 816bp at the 3' end. 97bp at the 5' end and 171bp at the 3' end of QD1 and QD2 strains were homologous with CN strain about 99.3%, and about 777bp were absent in the middle. The above data showed that the variable region genes of WSSV had mutated more in China. The variable region gene of QD2 strain was coincidence with that of QD1 after propagating 10 generations in crayfish. The results indicated that the crayfish inoculation did not result in mutation of variable region genes of WSSV.

Immunoproteomic approaches were undertaken to study the immunogenicity of the membrane-associated proteins of the Streptococcus suis type 2 (SS2) China vaccine strain HA9801. The membrane-associated proteins were enriched using the Triton X-114 extraction protocol and were analysed by two-dimensional gel electrophoresis (2-DE) and subsequent immunoblotting using the hyperimmune serum of SS2-HA9801-immunized specific pathogen free (SPF) minipigs. A total of 11 proteins were recognized, and the corresponding spots on a duplicate gel were excised and identified by MALDI-TOF MS.

In December 2004, three influenza H1N2 viruses were isolated from lung samples of pigs that had died from respiratory disease on a farm in southeastern China. To determine the genetic characterization and probable origin, one of the three isolates, A/Swine/Zhejiang/1/2004 (Sw/ZJ/1/2004), was genetically analyzed. Sw/ZJ/1/2004 was a reassortant with an NA gene most closely related to the corresponding gene from a human-like H3N2 virus circulating in 1995. The remaining seven genes were most closely related to those from the classical swine H1N1 virus. Sw/ZJ/1/2004 appeared to be a novel reassortant H1N2 virus that was genetically distinguishable from other H1N2 viruses found in pigs worldwide. The isolation of Sw/ZJ/1/2004 provided further evidence for pigs serving as a "mixing vessel" for the generation of new reassortant genotypes of influenza viruses and emphasizes the importance of reinforcing influenza virus surveillance in pigs in China.

The general distribution of monogenean parasites of aquatic vertebrates inhabiting Chinese inland waters is summarised. Five hundred and seventy-two out of a total of 581 species of monogeneans were discovered on fish, while only nine species were found on Amphibia and Reptilia. Most dactylogyrids and diplozoids parasitise cyprinids, while ancyrocephalids occur on silurids and cyprinids, and gyrodactylids are found mainly on cyprinids and cobitids. Analyses of host-specificity and host-diversity suggests that the family Ancyrocephalidae should be divided into several families parallel with the Dactylogyridae. Of 12 subfamilies of the Cyprinidae, only the Gobiobotinae was found to be free of infection with monogeneans, and the genus Dactylogyrus has more species than any other monogenean genus associated with every cyprinid subfamily.

Seventy-six serum samples of Chinese soft-shelled turtles (Trionyx sinensis) were collected at Jiangsu Province, China. The neutralization test (NT) was performed with the sera, Testudo herpesvirus (THV) and turtle heart cells (THC). Neutralizing antibodies were detected in five of 76 samples and the titres were 1:10-1:20. Having optimized the conditions, the dot-enzyme-linked immunosorbent assay (Dot-ELISA) was developed and eight serum samples exhibited positive results. Five samples were positive by both NT and Dot-ELISA. The percentage of positive samples was only 6.6% (NT) and 11% (ELISA). It is suggested that THV infection is not a serious problem for the Chinese soft-shelled turtle culture in this region.

Neonatal calf diarrhea is a significant health problem in dairy industry in the whole world. Although the aetiological agents of neonatal diarrhea are diverse, it is obvious that viruses play an important role. One of them is bovine coronavirus (BCV). Since BCV was discovered (MEBUS et al., 1969), there have been many published reports describing the virus and its importance in calves. In China, we first investigated the seroepidemiological status of BCV infections in cattle (YAO et al., 1990). The results showed that the incidence of infections with BCV in cattle in different chinese regions are high. Further work on direct diagnosis of BCV as a causative agent of diarrhea was therefore necessary. In the last years we have developed diagnostic methods including a monoclonal antibody-based ELISA to detect BCV and other diarrheal viruses. In this study, the diagnosis of an outbreak of BCV in chinese dairy cattle is described.