RESUMO
Objective To analyze the epidemic characteristics of the hand-foot-mouth disease (HFMD) in four years before and after EV71 vaccine inoculation, and to provide a basis for better EV71 vaccination and prevention and control of HFMD. Methods The descriptive epidemiology method was used to analyze the monitoring data of HFMD from 2013 to 2020 and EV71 vaccination from 2017 to 2020 in Xinwu District of Wuxi City. Results A total of 9 589 HFMD cases including 104 severe cases (accounting for 1.08%) were reported in four years before EV71 vaccination, and the reported average annual incidence rate was 431.15/100 000. A total of 7 396 HFMD cases including 21 severe cases (accounting for 0.28%) were reported in four years after vaccine inoculation, and the reported average annual incidence rate was 325.28/100,000. Annual incidence rate and severe illness rate decreased significantly before and after vaccine inoculation. The HFMD incidences displayed two epidemic peaks, from May to June and from October to November. The three streets with the highest average annual incidence were Jiangxi, Meicun, and Shuofang. The HFMD cases were mainly children under 5 years old, and there were more men than women. A total of 394 samples were sent for examination from 2013-2020, and 231 were positive, with a total positive rate of 58.63%. There were significant changes in the etiological composition before and after vaccine inoculation. The composition of EV71 virus decreased significantly (χ2=69.70, P2=22.35, P<0. 05). From 2017 to 2020, a total of 12 472 people were inoculated with EV71 vaccine in Xinwu District of Wuxi City, with estimated annual vaccination rates of 3.78%, 10.96%, 8.40% and 7.63%, respectively. Conclusion There is no significant change in time, region and population distribution of HFMD before and after EV71 vaccination in Xinwu District of Wuxi City, but the annual incidence rate and severe illness rate show a decreasing trend, and the dominant intestinal pathogens have changed. It is suggested to strengthen the use of EV71 vaccine and the development of multivalent HFMD-related vaccine.
RESUMO
The objective of the study was to clone avian beta-defensin (AvBD) 5 gene from pigeon bone marrow tissues and liver tissues, to express the recombinant AvBD5 protein in E. coli, and to determine its antimicrobial activity. The mRNA of duck AvBD5 was cloned from pigeon bone marrow tissues and liver tissues by RT-PCR. In addition, phylogenetic relationships between amino acid sequence of the pigeon AvBD5, AvBDs from other avian species, and some mammalian beta-defensin-5 were analyzed. The cDNA of pigeon AvBD5 was sub-cloned into pGEX-6p-1 vector to construct recombinant plasmid pGEX-pigeon AvBD5. The recombinant protein was expressed into E. coli and purified. Antimicrobial activity and physical-chemical stability of the recombinant fusion protein were measured in vitro. The complete nucleotide sequence of both cDNAs contained 201 bp nucleotides, encoding a polypeptide of 66 amino acids. Both beta-defensins have six conserved cysteines. Phylogenetic relationships were analyzed. Both pigeon AvBDs shared the highest amino acid homology (87.9% and 78.8%) with duck AvBD5. So it was named as pigeon AvBD5alpha (bone marrow) and AvBD5beta (liver). Both recombinant plasmids were transformed into E. coli BL21 and the bacteria were induced with Isopropyl beta-D-1-Thiogalactopyranoside (IPTG). After purification, antibacterial activity of the purified was investigated. In addition, effect of ionic strength on the antibacterial activity, and hemolytic recombinant protein activity of the purified recombinant protein were investigated. A 32 kDa protein was highly expressed. Both purified recombinant pigeon AvBD5alpha and AvBD5beta exhibited extensive antimicrobial activities against 12 bacteria, including Gram-positive and Gram-negative. In high salt ions concentrations, antibacterial activity of both recombinant proteins was decreased. In addition, the hemolysis activity of recombinant protein was extremely low.