Detection on antiserum of Yersinia pestis phage in Marmota himalayana blood in the natural plague foci of Qinghai-Tibet Plateau / 中国热带医学

@#Abstract: Objective　To detect and analyze the antiserum of Yersinia pestis phage in Marmota himalayana blood from the natural plague foci of Qinghai-Tibet Plateau by micro-bolus technique, to provide a theoretical basis for interaction between phages and mammalian immunology, phage therapy and interaction between bacteriophage and ecology in future. Methods　Using diagnostic Yersinia pestis phage and 3 wild plague phages from Qinghai-Tibet Plateau Natural Plague Foci as antigens, 847 serums of Marmota Himalayana blood, from Tongde, Guinan, Gonghe, Xinghai, Tianjun foci counties in Qinghai Plateau, were collected from July to September in 2020, 2021 and determined on antiserum of Yersinia pestis phage by microplate method and double agar plate method. Results　The neutralization reaction experiment lasted for 24 hours between 4 phage and 847 serums by microplate method independently. These mixtures were tested by double agar plate method. All results were negative on antiserum of Yersinia pestis bacteriophage. Conclusions　The positive antiserum of Yersinia pestis phage in Marmota himalayana were not found the natural plague foci of Qinghai-Tibet Plateau, which agreed with plague epidemiology in 5 foci counties in Qinghai plateau from 2020-2021, that was a characteristic of the resting period. In other words, it was in the absence of plague pathogen. It also showed indirectly that the absence or weak presence of Yersinia pestis bacteriophage in the plague foci. It showed a lower frequency on host animals coming into contact with phages naturally. The antiserum of Yersinia pestis phage may be related to the form of plague infection and the intensity of the disease.

Murine enteroids culture system and Marmota Himalayana Hepatovirus replication by the enteroids / 中华实验和临床病毒学杂志

Objective@#To establish mouse intestinal tissue and its application in the proliferation of Marmota Himalayana hepatovirus (MHHAV).@*Methods@#The intestinal crypts of Balb/C mice were digested with EDTA at a high concentration, cultured in Matrigel and passaged into frozen intestinal enteroids. The monolayers were inoculated on 96-well plates and infected with MHHAV. Real-time qPCR virus concentrations at different time points were compared with those of a number of cell lines routinely used to develop hepatitis A virus.@*Results@#The mouse intestinal tissue culture system was successfully established. MHHAV did not proliferate in the cell lines commonly used for the culture of hepatitis A virus, but proliferated well in the intestinal tissues of mice. The virus multiplied about 3 700 fold in 4 days.@*Conclusions@#Mice intestinal enteroids can be used for the isolation and culture of MHHAV.

Survey on the internal parasites infection and control technique in albinism Marmota himalayana / 中国比较医学杂志

Objective To investigate the internal parasites infection in albino Marmota himalayan,and to provide a basis for seting up the quality standard of Marmota himalayana.Methods 21 wild albinism and 30 wild nomal Marmota himalayana from the same origin were detected by method as intestinal parasites in stool examination and serological testing, toxoplasma gondii and echinococcosis parasite infections of each animal, then detected the internal parasites and eggs under platoscope and microscope.Results The natural infectious rate of the roundworm in wild albinism and nomal Marmota Himalayana were respectively 71.4% (15 /21) and 66.7% (20 /30), using the exact probability method of inspection, there was no significant difference in the roundworm infection rate between two groups marmota; antibody test results of Serum toxoplasma gondii and Echinoocosis were negative.Application of albendazole and Ivermectin injection drug expelling and purification, effect to be trusted.Conclusions Monitoring results and the cure method can be used as an albino Himalayan marmot displacement experiment of animal parasite quality monitoring index and purification method.

Study on the natural foci of Marmota himalayana plague in Sichuan province / 中华流行病学杂志

Objective To explore the existence of natural loci on Marmota himalayana plague in Sichuan province and to provide basis for prevention and control of the disease. Methods Both epidemiological investigation and laboratory tests were used to provide the host animal and fleas of the vectors with Yersinia pestis carriers. Results 30 species of animals were found to belong to 10 orders. Ochotona curzoniae and M.himalayana were the most common ones while 7 species of the fleas belonged to 7 genera and 3 families. M.himalayana was the main reservoirs while Callopsylla dolabris and Oropsylla silantiewi served as vectors. The 13 Y.pestis were identified from 43 Marmota samples. 8 samples were identified under IHA, with the highest titer of herding-dogs serum as 1 : 10 240. 19 samples were F1 antigen positive using RIHA and the highest titer of M.himalayana serum was 1:409 600. The major foci was 4545 km2, distributed at Dege county in Sichuan province. Conclusion We have confirmed the existence of natural foci on M. Himalayana plague in Sichuan province.