Isolation and Identification of Pathogenic Bacteria Causing Bovine Subclinical Mastitis in Eastern Hebei Province

In this study, the milk samples of 1 021 cows in eight dairy farms in Eastern Hebei Province were collected and detected with LMT reagent and somatic cell count for subclinical mastitis. Pathogenic bacteria in subclinical mastitis positive milk samples were isolated and identified.The results showed that 60.63%（619/1 021） of the sampled cows were diagnosed with subclinical mastitis, and mixed infections accounted for 88.21%（546/619） of the cases. In addition, 82 strains of 14 species were isolated from the subclinical mastitis positive milk samples, including 36 strains of Staphylococcus（43.90%）, 33 strains of Streptococcus（40.24%）, 8 strains of Enterobacteriaceae（9.76%） and 5 strains of Corynebacterium（6.10%）, respectively. The results proved that Staphylococcus aureus and Streptococcus agalactiae are the main pathogenic bacteria causing bovine subclinical mastitis in Eastern Hebei Province.

Isolation and Identification of Pathogenic Fungi Causing Decayin Luotian Chestnut during Late Storage Period and Research on Pathogenicity

In order to explore moldy mechanism of chestnut from Luotian County in storage process,the strains of pathogenic fungi were isolated from chestnuts after storage at room temperature for 70d.Six genera of fungi were found in chestnut through experimental identification,which were Ozoniumsp.,Fusarium sp.,Aspergillus sp.,Penicilliumsp.,Rhiopus sp.and Stachybotrys sp.,respectively.The re-inoculation tests had been conducted on pathogenic fungi whose isolating rate was greater than 10%.The result showed that the rest genera of fungi generally had no pathogenicity except Penicilliumsp.could infect non-injured chestnut with a lower moldy rate and lighter symptoms;but the moldy rate of strains was above 60% in injured inoculation and they showed heavy symptoms,among which the moldy rate of Ozoniumsp.and Aspergillus sp.were higher than 80%.The experimental results showed that injured chestnut were more likely to decay.Ozoniumsp.and Aspergillus sp.were important pathogenic fungi causing decay during storage process of chestnut.

Pathogenicity Assay and Molecular Identification of Fungi and Bacteria Associated with Diseases of Tomato in Malaysia

This study was conducted in order to determine the fungi and bacteria associated with tomato plants at Cameron Highlands Malaysia. The fungi which have been isolated and detected from tomato plants were: Fusarium oxysporum, F. solani, F. acuminatum, Rhizoctonia solani, Colletotrichum boninense, C. acutatum and Phoma destructiva. The bacteria which have been isolated and detected from tomato plants were: Ralstonia solanacearum, Xanthomonas vesicatoria, X. gardneri and Pseudomonas syringae. While the most pathogenic fungi were C. boninense, P. destructive and F. oxysporum with the disease incidence (89.6%, 86.6%, 85.6%) respectively, the most pathogenic bacteria were X. vesicatoria and R. solanacearum with the disease incidence (96.6% and 87.6%) respectively.

Characterization of Highly Pathogenic Avian Influenza H5N1 Viruses Isolated from Domestic Poultry in China

The highly pathogenic avian influenza （HPAI） H5N1 virus has caused several outbreaks in domestic poultry. Despite great efforts to control the spread of this virus, it continues to evolve and poses a substantial threat to public health because of a high mortality rate. In this study, we sequenced whole genomes of eight H5N1 avian influenza viruses isolated from domestic poultry in eastern China and compared them with those of typical influenza virus strains. Phylogenetic analyses showed that all eight genomes belonged to clade 2.3.2.1 and clade 7.2, the two main circulating clades in China. Viruses that clustered in clade 2.3.2.1 shared a high degree of homology with H5N1 isolates located in eastern Asian. Isolates that clustered in clade 7.2 were found to circulate throughout China, with an east-to-west density gradient. Pathogenicity studies in mice showed that these isolates replicate in the lungs, and clade 2.3.2.1 viruses exhibit a notably higher degree of virulence compared to clade 7.2 viruses. Our results contribute to the elucidation of the biological characterization and pathogenicity of HPAI H5N1 viruses.