Molecular typing of 12 Brucella strains isolated in Guizhou province in 2010-2013 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To identify and characterize the Brucella strains from Guizhou province in 2010-2013.</p><p><b>METHODS</b>A total of 12 strains of Brucella suspicious bacteria were isolated in Guizhou province from 2010 to 2013. Four strains (GZLL3, GZLL4, GZLL11 and SH2) were isolated from goat blood samples and eight strains (SH4, GZZY, GZSQ, GZZA, BR13001, BR13004, BR13005 and BR13006) were isolated from blood samples of patient 12 Brucella suspicious strains were identified and characterized using conventional methods. Brucella genus specific gene BCSP31-based PCR (BCSP31-PCR) was used to identify the genus of Brucella and IS711 insert sequence-based PCR (AMOS-PCR) was applied to identify the species of Brucella strains. Goats and patients originated Brucella strains were comparatively analysed using Pulse-field Gel Electrophoresis (PFGE).</p><p><b>RESULTS</b>Both of conventional methods and PCR identified the 12 Brucella suspicious strains as B. melitensis biotype 3. BCSP31-PCR identification results showed that a specific DNA bands (223 bp) were detected in all the 12 strains and positive control samples with no DNA band in negative samples. AMOS-PCR amplified a 731 bp-DNA bands in all the 12 strains, with 731 bp, 498 bp and 275 bp in M5, S2 and A19 strains, respectively, and no DNA band was detected in the negative control samples. PFGE analysis showed that 12 Brucella isolates from patients and goats showed consistent PFGE patterns with the digestion of restriction enzyme Xba I.</p><p><b>CONCLUSION</b>The epidemic species/type of Brucella in both human and animal in Guizhou province was B. melitensis biotype 3 and goat was the main animal source of infection of brucellosis in Guizhou province.</p>

A investigation of plague foci in Beipanjiang Basin, Guizhou Province / 中华地方病学杂志

Objective To survey the major host animal and media fleas of plague in Beipanjiang Basin,to gain insights into plague foci and to provide a basis for prevention and control of plague.Methods According to the epidemiological site survey methods,from 2008 to 2010 five villages in five townships (towns) in coastal watershed of Beipanjiang were selected.The methods of cage trapping and 5 meters thread clamp were used to capture rodents indoor and outdoor,respectively.After rats were anesthetized with ether anesthesia,rat body flea were combed and stored in sterile tubes.The liver and spleen of rodents were collected and stored in the test tube with preservation solution,and free body fleas on rats were collected with flea sticky paper and stored in sterile tubes.Blood specimens (5 ml) of indicating animal and normal people were collected,serum was separated and sent for laboratory test.The four-step method was utilized to isolate Yersinia pestis from rodents and fleas,the indirect hemagglutination (IHA) was used to test F1 antibodies on the blood of rodents filter,blood serum of humans and rodents.Results Totally 243 rodents were captured,202 indoor and 41 outdoor,the capture rate was 4.90％ and 1.15％,respectively.Rodents captured belong to 9 species,4 genera,1 family and 1 order,Rattus flavipectus and Mus pahari were dominant species.Five rodents had body flea,the dyed flea rate was 2.06％;53 fleas were captured,total flea index was 0.218 1.Rat fleas were classified in 2 families,2 genera and 2 species,and Cheopis was the dominant species.Yersinia pestis and plague F1 were not detected.Conclusion The epidemic indication has not been found in Beipanjiang Basin,but the nurturing conditions for Rattus flavipectus plague foci along the coast are exist.

Risk analysis of the plague in regions with large scale engineering construction project in Guizhou Province in 2000-2011 / 中华地方病学杂志

Objective To investigate the status of the plague natural focus and assess the risk of plague in regions with large scale engineering construction project,in order to provide a basis for plague prevention and control.Methods The survey was carried out in 14 regions with large scale engineering construction project of 40 counties in Guizhou Province in 2000-2011,2-3 towns were selected in each county and 2-3 villages in each town,the plague hosts and flea vectors in the residential houses and outdoors were investigated,the sera of 5 animals were collected in each village.The capture rate of hosts and flea index were calculated.Then the samples were cultured and serological tested for plague.Results The density of rodents was 1.14％-3.87％ in the reservoir region' residential building of hydro power station (Tianshengqiao,Pingban,Silin,Guangzhao,Sanbanxi,Dongqing,Qianzhong,Shatuo) and Xingyi airport,and Rattus flavipestus was the dominant species.The density of rodents was 0.00％-0.84％ in the reservoir region of hydro power station (Hongjiadu,Yingzidu,Goupitan,Longtan) and Jinyang district; the total flea index in Yinzidu,Pingban,Longtan reservoir regions of hydro power stations were 3.16,2.00,1.06,3.47 and 1.99,respectively.A total of 21 rodent and flea samples from Tianshengqiao hydro power station were tested positive for F1 antigen of the plague.Three strains of Yersiniapestis were isolated.Nine rat filter paper blood samples and 7 sera of indicative animals were tested plague F1 antibody positive.Other regions with large scale engineering construction project were tested negative.Conclusions The reservoir region of Tianshengqiao hydro power station is endemic areas of the plague,where belong to high risk areas.The density of Rattus flavipestus is higher than the controlling standard of the country in the reservoir region of hydro power station (Pingban,Silin,Guangzhao,Sanbanxi,Dongqing,Qianzhong,Shatuo),where belong to potential risk areas.The plague prevention and monitoring should be continually strengthened to reduce the risk of plague.

Analysis of plague monitoring results and epidemic trend from 2000 to 2012 in Guizhou Province / 中华地方病学杂志

Objective To master the prevalence of plague and its trend in Guizhou Province,and to analyze the plague monitoring results from 2000 to 2012.Methods The report of infectious disease,the information of plague natural focus and the epizootic monitoring data of Xingyi City,Anlong County and Dingxiao Distract of Guizhou Province from 2000 to 2012 were collected and the status of the plague natural focus was analyzed.Results There were 137 cases of gland plague in Xingyi City and Arlong county from 2000-2003,1 death,and mt plague occurred in 66 villages.Fifty-four strains of Yersiniapestis were detected and 49 rats were plague antigen F1 positive(49/160).No human plague occurred between 2004-2012.A total of 4 plague antigen F1 positive rats were detected in Dingxiao District and Xingyi City in 2005 and 2006.There was no Yersinia pestis and F1 antibody in 2007-2012.The epidemic stage of plague was from 2000-2003; the active stage was from 2004-2006; and the quiescent stage was from 2007-2012.The dominant species of the plague natural focus was Rattus flavipestus (42.83％,7 966/18 597),but was replaced by Rattus norvegicus at the epidemic stage (47.22％,1 480/3 134) and the active stage(35.35％,2 071/5 196).The density of rodents was 5.34％ at the epidemic stage,which was higher than that of the active stage (3.27％) and the quiescent stage (1.71％,x2 =2 286.15,P ＜ 0.01).Xenopsylla cheopis(56.34％,10 034/17 811) was the dominant species,and the index was 1.537 9,which was greater than those of the active stage(0.959 6) and the quiescent stage(0.540 4,x2 =492.68,P ＜ 0.01).Conclusions The plague of Guizhou Province is at the quiescent stage.Both the density of rodents and the Xenopsylla cheopis index are lower than the national standard of controlling.