A novel circovirus called porcine circovirus type 3 (PCV3) was recently reported to exist in the USA. This circovirus is associated with porcine dermatitis, nephropathy syndrome and reproductive failure. This study reports on the first identification, widely epidemic, different phylogenetic clusters, potential role in sow reproductive failure and possible origins of PCV3 in China.

Forty-seven strains of H9 subtype avian influenza viruses identified by specific reverse transcription-PCR method were isolated from the chicken and duck flocks in different areas of China during the 2002 to 2009 epizootic period. Hemagglutinin (HA) genes of these strains were sequenced and analyzed with the representative strains published in GenBank. The results indicated that the HA genes of these strains and the vaccine strains displayed nucleotide homologies ranging from 91.7 to 96.6% and amino acid homologies ranging from 92.3 to 95.7%, respectively. Analysis of the mature peptide sequences of these HA genes showed that the presence of leucine at position 216 (corresponding to residue 226 in H3 numbering) indicated a preference to the binding of alpha (2-6) sialic acid receptors, which was the same as human isolates. Extra potential glycosylation sites appeared in the HA genes of most tested isolations compared with the vaccine strains. The HA cleavage sites of most of the strains were the 335PSRSSR downward arrow GLF341, but all of the strains met the characteristics of low-pathogenic avian influenza. The results of phylogenetic analysis indicated that all 47 strains and the current vaccine strains belong to the same phylogenetic lineage h9.4.2, but they had some genetic deviation in the last decade. Compared with the vaccine strains, 7 mutations were found in the antigen epitope region of the HA genes of the field strains. These results suggested that the commercial vaccine might not induce satisfactory prevention against infection of H9N2 avian influenza virus.

This study was conducted to determine the effects of dietary cellulase addition on improving the nutritive value of Chlorella for juvenile crucian carp Carassius auratus (initial body weight: 2.99 ± 0.02 g, mean ± SEM). Five isonitrogenous and isoenergetic experimental diets were formulated to contain 0.0 (control), 0.5, 1.0, 1.5 and 2.0 g kg−1 cellulase, respectively. Each experimental diet was randomly assigned to triplicate groups with 25 juvenile fish per fibreglass tank for 8 weeks. The results showed that weight gain, specific growth rate, feed intake and the trypsin activity in the anterior intestine increased with increasing dietary cellulase to 1.5 g kg−1 and then declined with further addition. However, the mRNA expression levels of Mrf4 and Myf5, the apparent digestibility coefficients for dry matter, protein, energy and the majority of amino acids, and the activity of lipase in the anterior intestine were highest in fish fed the 1.0 g kg−1 cellulase diet, and then tended to decline with further cellulase supplementation. In conclusion, the optimal dietary cellulase supplementation level was 1.0–1.5 g kg−1, which can improve growth performance, digestive activities and nutrient digestibility in crucian carp.

Aim:  To study effects of cyclic adenosine monophosphate (cAMP) on development and secondary metabolites of Monascus ruber M‐7. Methods and Results:  Plate culture, liquid‐state fermentation (LSF) and solid‐state fermentation (SSF) were used to evaluate effects of cAMP on colonial growth, spore formation and polyketide production of Strain M‐7. The results revealed that the variation trends of colonial sizes, numbers of sexual spores and red pigment contents of M‐7 were in a dose‐dependent manner. And generally they increased and decreased with cAMP concentrations in the ranges of low cAMP concentrations and high cAMP concentrations, respectively. But the variation trends of numbers of asexual spores and citrinin production in both LSF and SSF were opposite to those of colonial sizes, sexual sporulation and red pigment. Conclusions:  The regulation of cAMP on development and secondary metabolites in Strain M‐7 was in a dose‐dependent pattern. And red pigment might convert to citrinin under changing cAMP concentrations. Significance and Impact of the Study:  The effects of cAMP on Strain M‐7 in SSF give a new clue to enhance beneficial polyketides and reduce citrinin produced by M. ruber.