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Chitin, the most abundant bio-polymer in seawater, may be utilized by various microorganisms as a carbon source. Vibrios have been regarded as one of the main groups of chitin consumers in the marine carbon cycle and chitinase producers. The organisms are widely distributed in the aquatic environment. However, the co-working mechanism between their chitinases, and whether the chitinase’s diversity contributes to their adaption to the environment, needs to be further elucidated. Here, we obtained a chitinolytic strain, Vibrio harveyi WXL538 with eight putative chitinase-coding genes. Five of the genes, i.e., Chi4733, Chi540, Chi4668, Chi5174, and Chi4963, were overexpressed and validated, in which Chi4668, Chi4733 and Chi540 were purified and characterized. The result of Chi4668 was described in our previous study. Endo-chitinase Chi4733 degraded colloidal chitin to produce (GlcNAc)2 and minor (GlcNAc)3. The enzymatic activity of Chi4733 was 175.5 U mg−1 and Kcat/Km was 54.9 s−1 M−1. Chi4733 had its maximum activity at 50°C and pH 4–6, activated by Sr2+, Co2+, Ca2+, and Mg2+ and inhibited by Al3+, Zn2+, Cu2+, Ni2+, and SDS. Exo-chitinase Chi540 degraded colloidal chitin to (GlcNAc)2. The enzymatic activity of Chi540 was 134.5 U mg−1 and Kcat/Km was 54.9 s−1 M−1. Chi540 had its maximum activity at 60°C and pH 6–8, was activated by Sr2+, Ca2+, and Mg2+ but inhibited by K+, Ba2+, Zn2+, Cu2+, Ni2+, SDS and urea. Whole genome analysis of V. harveyi WXL538 and characterization of its chitinase can provide a better understanding of its adaptability to the changing marine environment.

Abstract Background PCV3 is a pathogen associated with porcine dermatitis and nephropathy syndrome (PDNS)-like clinical signs, reproductive failure, and cardiac and multiorgan inflammation, which was newly identified in 2016 in sows in USA. Recently, PCV3 has also been identified from several non-porcine species like (cattle, dog, wild boar, deer, mice and ticks). However, PCV3 infection in donkey is not well established. Since 2019, 300 blood samples were collected from female donkey, which was characterized by abortion and sterility, in Liaocheng city of China. Results In the present study, an investigation of PCV3 in donkey blood samples was undertaken employing by real time PCR. Positive rates of PCV3 in donkeys reach to 21.0 %. In addition, one full-length PCV3 genome sequence was obtained, and it had a highest identity with porcine circovirus 3 PCV3/CN/Nanjing2017 strain and is clustered to PCV3a genotype based on ORF2 sequences. Conclusions This is the first report of detection of PCV3 from female donkeys presenting reproductive failure in large-scale donkey farms, China. In addition, the PCV3 strain identified in this study shared the closest relationship with those from porcine, suggesting that PCV3 may be transmitted from pigs to donkeys. Totally, PCV3 infection in donkey should be concerned although the association between it and reproductive failure are not better understood.

Inadvertent intraoperative hypothermia (core temperature 2 h (OR = 3.44, 95% CI 1.90-6.22,), and intravenous un-warmed fluid (OR = 2.45, 95% CI 1.45-4.12) significantly increased the risk of hypothermia.The incidence of inadvertent intraoperative hypothermia in Beijing is high, and the rate of active warming of patients during operation is low. Concern for the development of intraoperative hypothermia should be especially high in patients undergoing major operations, requiring long periods of anesthesia, and receiving un-warmed intravenous fluids.