Progress in probiotics for treating Clostridioides difficile infection / 中华微生物学和免疫学杂志

Clostridioides difficile infection (CDI) is an infectious disease with fever, abdominal pain and diarrhea as the main clinical manifestations. At present, CDI is mainly treated with antibiotics and faecal microbiota transplantation. As recurrent and refractory CDI continues to increase, it is important to seek a more effective alternative therapy. However, many of the studies on the prevention and control of CDI by probiotics are still in the early stage. This paper summarized the research on the types, mechanisms and technical means of probiotics in the treatment of CDI.

Initial exploration of discordance in public health standards in China / 中华流行病学杂志

Discordance, such as overlap, repetition and inconsistent, of standards is one of the major problems in current standardization affair in China. Therefore, improving the unity and authority of standards through reduction of overlap, repetition and inconsistency has become the main goal of deepening standardization reform in China. This paper summarizes the discordance in public health standards in China, analyzes the major reasons and provides specific strategic suggestions through case analysis of public health standards in the ways of comparisons of same kind standards of other deparments and standards in administration documents and guidelines or technical specifications of academic associations or societies.

Interpretation of policies for group standards and the practice of group standardizations in Chinese Preventive Medicine Association / 中华流行病学杂志

Recent years, national laws and government policies were published as series to encourage the development of group standardizations. The updated Standardization Law of the People's Republic of China, implemented on January 1st, 2018, stipulates that group standard is a part of the Chinese standard system. Under the current supportive circumstances, more institutes and organizations have joined in the writing and releasing procedures of group standards’. Despite the rapid development of group standardization to publish, we are still at the phase of exploring and regulating group standardizations. This review summarizes the development and practice on the development group standardization in the Chinese Preventive Medicine Association and analyzes current condition and deficiency of the work in China, in order to develop suggestions and strategies to improve and regulate group standardization.

Standardization and application on ribotyping library of Clostridioides difficile in China / 中华流行病学杂志

Objective@#To establish a standard operation procedure (SOP) for ribosome genotyping (ribotyping) on Clostridioides (C.) difficile, supplement and verify ribotyping typing library, so as to improve the comparability of data between different laboratories and to develop surveillance network of C. difficil in China.@*Methods@#Molecular typing of 54 reference strains from the United States and Europe of C. difficile were performed by using the SOP referencing correspondence from abroad and from our laboratory with a BioNumerics 7.6 software to estimate the reference library of types of C. difficile. Identification of 374 clinical and animal isolates of C. difficile from 13 cities in China between 2010 and 2018, to supplement the library information. Kappa test was used to evaluate the consistency.@*Results@#Results of capillary electrophoresis of reference strains appeared clear and stable, which guaranteed the clustering results being fast and accurate. Results from the supplementary typing showed that there were 84 types of isolates, of which 25 RT types were consistent with reference strains from abroad, while 58 RT types were different from referenced types. In the 40 referenced types, 15 RT types were not found in this study. In the consistency evaluation, the Kappa value was 0.891 and (P<0.01), showing the two Molecular typing as consistent and with close resemblance.@*Conclusions@#The result of capillary electrophoresis by applying SOP for ribotyping on C. difficile base on QIAxcel capillary electrophoresis system, appeared clear and stable. The standardized library seemed more easily used for comparability and data sharing between the laboratories.

Association between distribution of bacillary dysentery and meteorological factors in Beijing, 2004-2015 / 中华流行病学杂志

Objective To analyze the distribution characteristics of bacillary dysentery in Beijing during 2004-2015 and evaluate the influence of meteorological factors on the temporal and spatial distribution of bacillary dysentery.Methods The incidence data of bacterial dysentery and meteorological data in Beijing from 2004 to 2015 were collected.Descriptive epidemiological analysis was conducted to study the distribution characteristics of bacterial dysentery.Linear correlation analysis and multiple linear regression analysis were carried out to investigate the relationship between the incidence of bacillary dysentery and average precipitation,average air temperature,sunshine hours,average wind speed,average air pressure,gale and rain days.Results A total of 280 704 cases of bacterial dysentery,including 36 deaths,were reported from 2004 to 2015 in Beijing,the average annual incidence was 130.15/100 000.The annual incidence peak was mainly between May and October,the cases occurred during this period accounted for 80.75％ of the total,and the incidence was highest in age group 0 year.The population distribution showed that most cases were children outside child care settings and students,and the sex ratio of the cases was 1.22 ∶ 1.The reported incidence of bacillary dysentery was positively associated with average precipitation,average air temperature and rain days with the correlation coefficients of 0.931,0.878 and 0.888,but it was negatively associated with the average pressure,the correlation coefficient was-0.820.Multiple linear regression equation for fitting analysis of bacillary dysentery and meteorological factors was Y=3.792 + 0.162X1.Conclusion The reported incidence of bacillary dysentery in Beijing was much higher than national level.The annual incidence peak was during July to August,and the average precipitation was an important meteorological factor influencing the incidence of bacillary dysentery.

Association between distribution of bacillary dysentery and meteorological factors in Beijing, 2004-2015 / 中华流行病学杂志

Objective To analyze the distribution characteristics of bacillary dysentery in Beijing during 2004-2015 and evaluate the influence of meteorological factors on the temporal and spatial distribution of bacillary dysentery.Methods The incidence data of bacterial dysentery and meteorological data in Beijing from 2004 to 2015 were collected.Descriptive epidemiological analysis was conducted to study the distribution characteristics of bacterial dysentery.Linear correlation analysis and multiple linear regression analysis were carried out to investigate the relationship between the incidence of bacillary dysentery and average precipitation,average air temperature,sunshine hours,average wind speed,average air pressure,gale and rain days.Results A total of 280 704 cases of bacterial dysentery,including 36 deaths,were reported from 2004 to 2015 in Beijing,the average annual incidence was 130.15/100 000.The annual incidence peak was mainly between May and October,the cases occurred during this period accounted for 80.75％ of the total,and the incidence was highest in age group 0 year.The population distribution showed that most cases were children outside child care settings and students,and the sex ratio of the cases was 1.22 ∶ 1.The reported incidence of bacillary dysentery was positively associated with average precipitation,average air temperature and rain days with the correlation coefficients of 0.931,0.878 and 0.888,but it was negatively associated with the average pressure,the correlation coefficient was-0.820.Multiple linear regression equation for fitting analysis of bacillary dysentery and meteorological factors was Y=3.792 + 0.162X1.Conclusion The reported incidence of bacillary dysentery in Beijing was much higher than national level.The annual incidence peak was during July to August,and the average precipitation was an important meteorological factor influencing the incidence of bacillary dysentery.

Progress in Application of Measuring Skeleton by CT in Forensic Anthropology Research / 法医学杂志

Individual identification by m easuring the hum an skeleton is an im portant research in the field of forensic anthropology. C om puted tom ography (C T ) technology can provide high-resolution im age of skeleton. Skeleton im age can be reform ed by softw are in the post-processing w orkstation. D ifferent skele-ton m easurem ent indexes of anthropology, such as diam eter, angle, area and volum e, can be m easured on section and reform ative im ages. M easurem ent process is barely affected by hum an factors. T his paper review s the literatures at hom e and abroad about the application of m easuring skeleton by C T in foren-sic anthropology research for individual identification in four aspects, including sex determ ination, height infer, facial soft tissue thickness m easurem ent and age estim ation. T he m ajor technology and the applica-tion of C T in forensic anthropology research are com pared and discussed, respectively.

Study on virulence factors of Candida tropicalis isolated from clinical samples / 中华流行病学杂志

Objective To determine the in vitro production of virulence factors for Candida (C.) tropicalis,including aspartyl proteinases,phospholipases and hemolytic activities,describe the regulation of virulence factors varying with time in C.tropicalis,and analyze the differences in aspartyl proteinases and hemolytic activities of C.tropicalis isolated from anatomically distinct sites.Methods A total of 64 C.tropicalis strains were spot-inoculated onto bovine albumin agar,egg yolk agar and sheep blood agar plates,respectively.Then the plates were incubated for 24,48 and 72 hour at 37 ℃,respectively.The aspartyl proteinases,phospholipase and hemolytic activities were determined at each time point,respectively.Results All the C.tropiclais isolates showed positive aspartyl proteinases and hemolytic activities at each time point,but no phospholipases activity was detected in C.tropicalis.On comparison of aspartyl proteinases and hemolytic activities at different time points,aspartyl proteinases activity at 48 and 72 hour was higher than that at 24 hour.During 72 hour,hemolytic activity of C.tropicalis increased.No statistical significant differences in aspartyl proteinases and hemolytic activities of C.tropicalis were observed among different infection sites (P=0.368 and 0.985).Conclusion The C.tropicalis clinical isolates in China have aspartyl proteinases activity,hemolytic activity,but have no phospholipase activity.

Study on genotype and virulence of Cryptococcus neoformans and Cryptococcus gattii clinical isolates in Guigang, Guangxi Zhuang Autonomous Region / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the species, genotypes and mating types of Cryptococcus neoformans and Cryptococcus gattii isolated from clinical samples in Guigang, Guangxi Zhuang Autonomous Region.</p><p><b>METHODS</b>A total of 20 Cryptococcus strains were isolated from clinical samples in Guigang from 2009 to 2012. The biological identification was conducted by polymerase chain reaction (PCR) to amplify internal transcribed spacer (ITS) sequences. The serotypes and mating types of C. neoformans and C. gattii were identified by PCR with serotype-specific and mating type-specific primers. The genotype was characterized by PCR fingerprinting and URA5 gene restriction fragment length polymorphism (URA5-RFLP). Phenotype study included growth test at 37 °C, melanin production test and urease test.</p><p><b>RESULTS</b>Among the 20 strains, 19 (95%) were identified as C. neoformans varieties (var.) grubii (serotype A, mating type α, genotype VN I), and only 1 was identified as C. gattii (mating type α, genotype VG I). The results of virulence test showed that all the strains grew well at 37 °C and positive in both urease test and melanin production test.</p><p><b>CONCLUSION</b>C. neoformans var. grubii (serotype A, genotype VN I and mating type α) was the predominant pathogen causing cryptococcosis in Guigang, and C. gattii strain was also detected.</p>

Establishment of multiplex PCR for the rapid identification and toxin detection of Clostridium difficile strains / 中华微生物学和免疫学杂志

Objective To design a multiplex PCR for simultaneous identification and toxigenic type characterization of Clostridium difficile isolates. MethodsThree pairs of primers were designed for the amplification of a species-specific internal fragment of the tpi( triose phosphate isomerase) gene, an internal fragment of the tcdB ( toxin B) gene, and an internal fragment of the tcdA ( toxin A) gene. Twenty-one standard strains including Clostridium difficile ATCC 9689 and 47 isolates of Clostridium difficile were applied for the assessment of detection limit, specificity and detections of the multiplex PCR, respectively. Toxin A and Toxin B of 47 isolates were analyzed by ELISA. ResultsThe detection limit for DNA concentration of the multiplex PCR was 0.5 pg/μl. The specificity was determined to be 100％. Among the results of 47 isolates detected by multiplex PC R, 37 strains were tpi ( + )/tcdA (+)/tcdB ( + ), 10 strains were tpi ( + )/tcdA (-)/tcdB ( - ). Tpi ( + )/tcdA ( - )/tcdB ( + ) was not found. The toxin detection of 47 isolates by ELISA showed that 20 isolates were positive and 27 isolates were negative. Twenty isolates of toxin (+) by ELISA were all tpi( +)/tcdA( +)/tcdB(+) by multiplex PCR. ConclusionThe multiplex PCR method combined diagnosis and toxigenic type characterization contributes to the diagnosis for Clostridium difficile infection.

Primary study on the gene typing, molecular characteristics of virulence and resistance associated gene of 12 Clostridium difficile clinical isolates in China / 中国人兽共患病学报

To investigate the gene typing, molecular characteristics of virulence and resistance associated gene of Clostridium difficile from clinical isolates in China, the genes tcdA,tcdB of toxin A and B, cdtA,cdt B of binary-toxin, and erm B of clindamycin resistance were detected by conventional PCR. Genotyping of toxic C. difficile were conducted by means of analysis of 16s-23s internal spacer region polymorphism with PCR assay. Then the antibiotic resistance of toxic C. difficile to ampiciline, clindamycin, metronidazole and vancomycin was conducted with E-test. It was found that 8 toxic C. difficile strains were demonstrated out of 12 clinical isolates, in which 5 strains were tcdA+ and tcdB+, and 3 strains tcdA- and tcdB+, accounting for 62.5% and 37.5% respectively. Binary-toxin genes detection were negative in all the strains. Clindamycin resistance associated gene ermB was positive in 4 out of 8 toxic C. difficile strains, accounting for 50%. 8 toxic isolates were typed into 4 gene types, the dominant type was ZR I,accounting for 62.5%. Resistance rate of 8 toxic C. difficile strains against ampiciline(AC), clindamycin(CM), metronidazole(MZ) and vancomycin(VA) was 37.5%,87.5%,12.5%, and 0 respectively. No isolates belonged to ribotype 027 or 078. Isolation rate of toxic C. difficile is high to 66.7%. There is obvious gene polymorphism in clinical isolates of Chinese toxic C.difficite, and ZR I is preponderant genotype in 4 genotypes. C. difficile shows some resistance to ampiciline, clindamycin, metronidazole, but susceptive to vancomycin.

Research on Clostridium Difficile Infection in Clinic Patients Feces Specimen / 中华医院感染学杂志

OBJECTIVE This study was to investigate the carrier and infection of Clostridium difficile in clinic feces specimen,to analyze clinic characteristics,and to improve isolation rate and to provide basis on efficient prevention.METHODS C.difficile toxin A&B kit and anaerobic culture was conducted in 20 cases with diarrhea.Colonies suspected to be C.difficile,on the basis of their macroscopic appearance and characteristic odor,oxygen tolerance experiment,were confirmed by their biochemical characteristics(API 20A,bioMerieux).RESULTS After C.difficile selective culture,8 suspected colonies from 20 feces specimen were conducted by feces smear and oxygen tolerance experiment.6 of 8 was G+ rod bacteria with positive oxygen tolerance experiment.4 stains of C.difficile were identified by API 20A,positive rate was 20%;toxin detect was positive in 1 specimen(5%).CONCLUSIONS Infection of C.difficile Is associated with the basic disease.Watery feces specimen was prone to culture positive.