Biological Effects of Chlamydiaphage phi CPG1 Capsid Protein Vp1 on Chlamydia Trachomatis In Vitro and In Vivo

The researches on chlamydia in recent years show that chlamydia bacteriophage may be a potential and effective means to solve the clinical infection of chlamydia trachomatis（Ct）. We investigated the biological effect of chlamydiaphage phi CPG1 capsid protein Vp1 on Ct both in Mc Coy cells and genital tract of mice. Different concentrations of Vp1 were co-incubated with Ct E serotype strain in Mc Coy cells. Female BALB/c mice were used to establish Ct E strain-induced urogenital infection model. They were randomly divided into five groups and given different treatments on the fifth day after Ct inoculation. Animals in groups 1 and 2 were given 30 μL different concentrations of Vp1 in the genital tract respectively, those in group 3 were intramuscularly injected with 30 μL Vp1, those in the infected group did not receive any intervention, and those in the control group received 30 μL PBS in the genital tract. The vaginal discharge was collected to identify the live chlamydia by cell culture and gene fragment by real time PCR different days after infection. Inhibition rate of 100 μg/m L and 50 μg/m L Vp1 proteins against Ct E strain in the Mc Coy cell cultures was 91% and 79% respectively. The number of intracellular Ct inclusion in the Mc Coy cells co-cultured with vaginal discharge of group 1 and group 2 was less than in the infected group, and that in group 1 was less than in group 2, on the 7th day after Ct inoculation. Real-time PCR showed that chlamydia concentration of the vaginal discharge in group 2 was lower than in the infected group, and that in group 1 was lower than in group 2 on the 10 th day. It was suggested that Vp1 capsid proteins had inhibitory effect on the proliferation of Ct serovar E strain in cell culture and mouse genital tract.

A review of trachoma history in China: research, prevention, and control

Trachoma is one of the most widespread blinding eye diseases, which is harmful to human visual health. The efforts to prevent and control trachoma in China can be divided into three periods, i.e., highly epidemic period, research on pathogenesis and control of trachoma, and blinding trachoma elimination and epidemiological evaluation. In 1956, Prof. Feifan Tang and Xiaolou Zhang first discovered and isolated Chlamydia trachomatis, which clarified the cause of trachoma, and kick-started a fresh chapter in trachoma research, prevention, and control around the world. Although, the prevalence of trachoma differed in different areas, the average prevalence once exceeded 50% and was as high as 90% in some areas before and at early liberation of China. Therefore, the government-led efforts were made to comprehensively prevent and control trachoma, including development of National Plan for the Prevention and Control of Trachoma, nationwide screening and treatment of trachoma, implementation of National Patriotic Health Campaign and improvement of water supply and lavatories. After decades of effort, China reached the goal of eliminating blinding trachoma in 2015. China has gained remarkable achievements in the prevention and treatment of trachoma, making outstanding contributions toward the goal of eliminating trachoma worldwide. The research, prevention, and control of trachoma in China were reviewed in this paper.

Elimination of blinding trachoma in China: why is further study necessary?

Sixty years ago,Prof.Feifan Tang and Xiaolou Zhang first discovered and isolated Chlamydia trachomatis,a finding that clarified the cause of trachoma and marked the beginning of a fresh chapter on trachoma research,prevention,and control worldwide（Tang et al.,1956;Tang et al.,1957a;Tang et al.,1957b）.