Impact of Toxoplasma gondii human infections on blood lipid levels / 中国血吸虫病防治杂志

Objective To evaluate the impact of Toxoplasma gondii human infections on blood lipid levels. Methods A total of 1 000 healthy volunteers that were randomly sampled from a tertiary hospital during the period from December 2017 through December 2019 were enrolled, and assigned into the infection group and the control group according to the detection of serum anti-T. gondii antibody using enzyme-linked immunosorbent assay (ELISA). The serum levels of total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglyceride (TG) were detected and compared between the two groups. Results The seroprevalence of anti-T. gondii antibody was 8.40% in the study subjects, and there were no significant differences between the infection and control groups in terms of gender (χ2 = 1.29, P > 0.05) or age (χ2 = 1.41, P > 0.05). The mean serum LDL (t = 3.89, P < 0.05) and TC levels (t = 3.81, P < 0.05) were significantly higher in the infection group than in the control group, while no significant differences were seen between the two groups in terms of mean serum TG (t = 0.97, P > 0.05) or HDL levels (t = 0.75, P > 0.05). In addition, the proportions of abnormal LDL (χ2 = 9.69, P < 0.01) and TC levels (χ2 = 10.39, P < 0.01) were significantly greater in the infection group than in the control group, while no significant differences were found in the proportion of abnormal TG (χ2 = 0.02, P > 0.05) or HDL level (χ2 = 0.11, P > 0.05) between the two groups. Conclusion T. gondii human infections affect blood lipid levels, and the individuals sero-positive for anti-T. gondii antibody have higher mean serum LDL and TC, as well as higher proportions of abnormal TC and LDL than sero-negative individuals.

Seroprevalence of Toxoplasma gondii infections among patients with autoimmune diseases / 中国血吸虫病防治杂志

Objective To understand the seroprevalence of Toxoplasma gondii infections among patients with autoimmune diseases, so as to provide the scientific evidence for the management of toxoplasmosis in patients with autoimmune diseases. Methods A total of 237 patients with definitive diagnosis of autoimmune disease were selected as the study subjects, including 79 cases with systemic lupus erythematosus, 71 cases with rheumatoid arthritis and 87 cases with inflammatory bowel disease, while 237 healthy volunteers served as controls. The serum anti-T. gondii IgG antibody was detected using enzyme-linked immunosorbent assay (ELISA) in patients with autoimmune diseases and healthy controls, and the detection of serum IgG antibody against T. gondii was compared between the autoimmune disease patients and healthy controls. Results The seroprevalence of serum IgG antibody against T. gondii was significantly greater in patients with autoimmune diseases than in healthy controls (29.96% vs. 4.22%; χ2 = 55.41, P < 0.01), and the seroprevalence of T. gondii infection was all significantly higher in patients with systemic lupus erythematosus (31.65%), rheumatoid arthritis (23.94%) and inflammatory bowel disease (33.33%) than in healthy controls (χ2 = 45.25, 26.58 and 50.95; all P values < 0.01). Conclusion The seroprevalence of anti-T. gondii IgG antibody is significantly higher in patients with autoimmune diseases than in healthy controls, and T. gondii infection may be a potential risk factor for the development of systemic lupus erythematosus, rheumatoid arthritis and inflammatory bowel disease.

Molecular characteristics of the genome of G I of Japanese encephalitis virus isolated from the specimen collected from viral encephalitis case for the first time / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the molecular basis of pathogenicity of Japanese encephalitis virus (JEV) by sequencing of complete nucleotide sequence and analyze the characteristics of full-length genome of genotype I Japanese encephalitis virus strains (GZ56) which was isolated from the first cerebrospinal fluid (CSF) of Japanese encephalitis patients.</p><p><b>METHODS</b>The complete nucleotide sequence was obtained by RT-PCR and sequencing was performed directly. Bioinformatics was used to analyze the nucleic acid data, deduced amino acid sequence and phylogenetic trees.</p><p><b>RESULTS</b>The result of sequence analysis showed that the genome of GZ56 strains had 10 965 nucleotides, which coded for a 3432-amino acid polyprotein. Phyolngenetic analysis based on full-length genome showed that GZ56 strains and M-28 strains which were the first isolated from mosquitoes in Yunnan in 1977 were in the same evolutionary branch. GZ56 strains belongs to genotype I of Japanese encephalitis virus, the homology of genome ranged from 96.2% to 98.6% in nucleotide and from 98.2% to 99.7% in amino acid sequences respectively when compared with selected genotype I of JEV strains in GenBank. There were 11 amino acid divergences in E protein when compared with the JEV inactivated P3 strain but they are not the key virulence sites. However, there were 14 amino acid divergences in E protein when compared with the JEV live attenuated vaccine SA14-14-2 strain and 8 amino acid divergences were the key virulence sites.</p><p><b>CONCLUSION</b>This study indicated that the full length of genome GZ56 strains had no ignificant change. It can be hypothesized from genomic level that the currently available JEV vaccines(inactivated and live attenuated) can protect against GZ56 strains infection, meanwhile, the JEV live attenuated vaccine (SA14-14-2) formulation conferred higher levels of protection.</p>

Reevaluate the effect of G-480 point mutation that determines the neurovirulence of type I vaccine polioviruses / 病毒学报

Whole genome sequencing of 9 type I circulating vaccine-derived polioviruses (cVDPVs) isolated in Guizhou Province in China revealed that reverse mutations did not occur in G-480 and U-525 which are known as the most important neurovirulence determinate sites, while other known neurovirulence determinate sites such as A-2438, A-2795, C-6203 and G-7441 did revert to Mahoney type. 5 type I cVDPVs were selected for neurovirulence test on PVR-Tg21 transgenic mice which express human poliovirus receptor gene based on their different nucleotide sequences, they all showed higher neurovirulence than P1/Sabin strain, and the neurovirulence of CHN8184 and CHN8229-1. 1 were comparable to that of wild type P1/Mahoney. The neurovirulence of CHN8229-1.1, CHN8229-2 and CHN8229-3 presented a trend of decreasing, but still laid in high level. There were 7 nucleotide mutations between CHN8229-1.1 and CHN8229-2, and only 2 between CHN8229-2 and CHN8229-3 in their whole genomes, but the neurovirulence among them were relatively different, showing that there must be some unknown neurovirulence determinate sites among these mutations. Computer predicted RNA secondary structure of stem-loop V of the poliovirus 5' NCR of Guizhou type I cVDPVs was relatively stable. In the situation that no reverse mutation occurred in G-480, some type I cVDPVs already showed high neurovirulence nearly equal to P1/Mahoney, it meant that the effect of G-480 point mutation that determined neurovirulence of P1/Sabin strain has been overestimated, G-480 was not the only important site to determine neurovirulence in P1/Sabin strain, others also may play the very important role. More details are needed to elucidate the mechanism of attenuation in type I polioviruses.

Study on an epidemic caused by the vaccine-derived poliovirus circulation in Guizhou province, 2004 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the circulating vaccine-derived poliovirus (cVDPVs) that occurred in Zhenfeng county, Guizhou province in 2004 and to discover wild-poliovirus, vaccine-derived poliovirus (VDPVs) and other vaccine-associated poliovirus which could cause clinical poliomyelitis.</p><p><b>METHODS</b>Field epidemiological studies at the epidemic area and collecting acute flaccid paralysis (AFP) case and contact stool specimen for virus identification and nucleotide sequencing. Analysis on data related to annual reports on stool specimens surveillance which involved AFP case and contacts in the resent years in Zhenfeng county.</p><p><b>RESULTS</b>Type-I VDPVs had been isolated from 2 AFP cases and 3 contact stool specimen in Wanlan village of Zhenfeng. After the first cVDPVs case was identified, there were 3 cases identified of having other vaccine-associated poliovirus of type-I or type-II in the 5 case of AFP that met the criteria of clinical poliomyelitis. The result of virological surveillance on polio showed that the EV isolation rate (55.1%) of Zhenfeng county was higher than the rate from the whole province of the same year (23.2%). The poliovirus (PV) isolation rate (36.8%) was obviously higher in 2004 than in the previous years. In the 16 PVs strains, the type-I accounted for 43.8% which was significantly higher than the average level (18.3%) from the whole province.</p><p><b>CONCLUSIONS</b>Data indicated that the type-I VDPVs had been circulating (cVDPVs) in Zhenfeng county in Guizhou province. Clinical poliomyelitis was caused by non-VDPVs. The increased PV infection and the decreasing rate of vaccination in the general population were responsible for the epidemic of type-I cVDPVs at this time. Monitoring and evaluation on the rate of routine immunization program and prediction of the trend of epidemic should be strenthened.</p>