Objective:To study the phenotype and genotype distribution of Yersinia pestis ( Y. pestis) in different natural foci of plague in China, so as to provide scientific basis for plague prevention and control. Methods:A total of 2 184 strains of Y. pestis isolated from different time periods, regions, hosts and vectors in 11 plague natural foci of China since 1943 were selected for biochemical type identification, glycolysis test, virulence factor test [capsule antigen (F1), pesticin Ⅰ (Pst Ⅰ), virulence antigen factor (VWa), pigmentation factor (Pgm)], different region (DFR) typing and clustered regularly interspaced short palindromic repeats (CRISPR) typing. Results:There were 16 biochemical types of Y. pestis in the natural foci of plague in China, and each biochemical type showed obvious regional distribution in each foci. Most strains were positive for ass hide glue glycolysis (89.79%, 1 961/2 184), maltose (80.13%, 1 750/2 184), glycerol (94.23%, 2 058/2 184), and denitrification (82.78%, 1 808/2 184), and negative for rhamnose (88.78%, 1 939/2 184) and melibiose (85.62%, 1 870/2 184). Virulence factor test results showed that 99.95% (2 183/2 184) of Y. pestis were F1 positive; 99.73% (2 178/2 184) of Y. pestis can produce Pst Ⅰ; 73.31% (1 601/2 184) of Y. pestis were VWa positive and 26.69% (583/2 184) were VWa negative; Pgm positive strains accounted for 72.62% (1 586/2 184), Pgm negative strains accounted for 21.52% (470/2 184), and Pgm mixed type strains accounted for 5.86% (128/2 184). According to DFR typing results, there were 52 genotypes in 2 184 strains of Y. pestis, of which 19 were major genotypes and 33 were minor genotypes. CRISPR typing revealed 16 major genotypes, of which 7 were newly discovered. Conclusion:The phenotypes and genotypes of Y. pestis in various natural foci of plague in China are diverse and have geographical distribution characteristics.

Objective:To understand whether there are drug resistant and disinfectant resistant Yersinia pestis strains in China, and to provide accurate information for clinical treatment of plague. Methods:A total of 2 753 Yersinia pestis strains isolated from 10 natural plague foci in China from 1943 to 2016 were collected. According to National Center for Biotechnology Information (NCBI) released sequences of aminoglycoside streptomycin resistant genes strA, strB, β-lactam antibiotics resistant genes TEM, SHV and CTX-M, sulfamilamide resistant genes sul1, sul2 and sul3, and disinfectant resistant gene qacE△1-sul1, a pair of primers of each gene was designed for above-mentioned genes. Genomic DNA of 2 753 strains of Yersinia pestis was extracted, and the 9 target genes of all DNA samples were amplified by PCR. Results:Negative and positive controls of PCR detection were established. No corresponding target bands of aminoglycoside streptomycin resistant genes strA, strB, β-lactam antibiotics resistant genes TEM, SHV and CTX-M, sulfamilamide resistant genes sul1, sul2 and sul3, and disinfectant resistant gene qacE△1-sul1 were found in the DNA samples of 2 753 strains of Yersinia pestis.Conclusion:The above-mentioned genes of drug resistance and disinfectant resistance have not been detected in Yersinia pestis of China, but the monitoring of drug resistance of Yersinia pestis still needs to be carried out continuously.

Objective:To analyze the pathogenic characteristics of Yersinia pestis in a plague natural foci in Qinghai-Tibet Plateau. Methods:In this study, 1 378 strains of Yersinia pestis isolated from different regions, hosts and vectors in Qinghai-Tibet Plateau from 1954 to 2016 were taken as the research objects. Phenotypic characteristics, plasmid spectrum and genotype of the strains were studied by using conventional techniques and molecular biological techniques. The etiology and geographical distribution of the plague were studied. Results:There were 6 biochemical types of Yersinia pestis in Qinghai-Tibet Plateau, namely Qinghai-Tibet Plateau, Qilian Mountain, Gangdis Mountain, Kunlun Mountain A, Kunlun Mountain B and Chuanqing Plateau. This study found that the Qinghai-Tibet Plateau type strain was not only distributed in north Tibet Plateau, but also distributed in south Tibet, and the distribution of Gangdis Mountain type strain extended to south Tibet. Four virulence factors (capsule antigen, yersinin, virulence antigen and pigmentation factor) were found in 79.97% (1 102/1 378) Yersinia pestis. The results also showed that there were 12 kinds of plasmids carried by Yersinia pestis strains in Qinghai-Tibet Plateau, which constituted 17 kinds of plasmid spectrum. There were 3 kinds of the largest plasmids with taxonomic properties, forming their respective relatively independent distribution areas. The study of different regions (DFR) type showed that 5, 8, 14, 19, 32 and 44 of 1 378 strains were the main genotypes, and the main genome types had obvious geographical distribution. Conclusions:All the tested strains have the characteristics of plague pathogen in Qinghai-Tibet Plateau. The polymorphism of the main hosts, vectors and the ecological landscape of plague geography in the plague foci in Qinghai-Tibet Plateau may lead to the diversity of biochemical characters, plasmid spectrum and geno types of Yersinia pestis.

Objective:To establish the minimum inhibitory concentration (MIC) detection method of Yersinia pestis by determining MIC of 11 kinds of antibiotics against Yersinia pestis, to master the inhibition range of common antibiotics on Yersinia pestis, and provide baseline data for clinical treatment of plague. Methods:According to Clinical Labor Standard Institution (CLSI), the agar plate dilution method was used to determine the MIC of 11 kinds of antibiotics against 118 strains of Yersinia pestis, including ofloxacin, ciprofloxacin, trimethoprim-sulfamethoxazole, kanamycin, streptomycin, ceftriaxone, ampicillin, chloramphenicol, spectinomycin, cefuroxime and tetracycline. MIC 50 and MIC 90 (the minimum concentration of drug which could inhibit 50% and 90% of bacterial growth) were calculated. The consistency was observed by comparing the results with those of the disk diffusion method. One hundred and eighteen strains of Yersinia pestis were isolated from natural plague foci of Qinghai Province and preserved by Qinghai Institute for Endemic Disease Prevention and Control. Results:Among 118 strains of Yersinia pestis tested, no single or multiple strains of Yersinia pestis resistant to 11 kinds of antibiotics were found, which was consistent with the results of the disk diffusion method. The MIC 50 and MIC 90 of 11 kinds of antibiotics against 118 strains of Yersinia pestis were obtained. Conclusions:The MIC detection method of Yersinia pestis is successfully established. This method can be used to measure the MIC of antibiotics against Yersinia pestis in high throughput and evaluate the sensitivity of Yersinia pestis to antibiotics. It is an efficient, economical and practical experimental method.

Objective: Tracking the information on 1.69 million fetal cases across Guangxi Zhuang Autonomous Region (Guangxi) so as to study the occurrences of total and major birth defects in order to evaluate the ability on related prevention and control programs in Guangxi. Methods: Using the self-developed "Gui Women’s System" to establish a database of 1.69 million fetal cases in Guangxi and to analyze the distribution of time, space and population, as well as the outcomes of pregnancy, using the big data. Results: During the 29 months of observation, the overall live birth rate was 99.25%, with stillbirth rate during pregnancy as 0.44%, stillbirth rate during birth as 0.02%, and the 0-6 days mortality rate as 0.14%. The total detection rate on birth defects was 197.63/10 000; the incidence rate was 103.04/10 000, the birth rate was 102.55/10 000. The overall discovery rate of major birth defects was 48.33/10 000, with the incidence rate as 783 000, the birth rate as 0.58/10 000. The discovery rates of major birth defects in 14 cities were between 35 and 68/10 000, and the birth rate dropped significantly to less than 1.00 in 10 000. Nationalities showed that the number of pregnant women with birth defects more than 50 000 would include Hui (9.68/10 000), Yao (9.57/10 000), and Jing (9.37/10 000). With the increasing age of gestation, number of birth defects, incidence of major birth defects also increased. Ninety-five percent of the major birth defects were found within <28 weeks and with the top 5 kinds of major birth defects as complicated congenital heart disease (9.11/10 000), alpha thalassemia (8.36/10 000), and 21-trisomy syndrome (7.85/10 000), beta thalassemia (5.32/10 000) and fetal edema syndrome (4.92/10 000). The top 5 major birth defects appeared as complicated congenital heart disease (9.11/10 000), alpha thalassemia (8.36/10 000), and 21-trisomy syndrome (7.85/10 000), beta thalassemia (5.32/10 000) and fetal edema syndrome (4.92/10 000). Conclusion Programs leading to increase the rate on discovery of major birth defects were fundamental in effectively reducing the major birth defects.

Objective: To investigate the distribution and related factors of birth weight of live births and full-term infants in Guangxi Zhuang Autonomous Region of China. Methods: Based on Guangxi women and children information system from 2016 to 2018, a large real-time database about maternal and live-birth information was established. It covered 1 712 midwifery institutions in Guangxi. A total of 2 394 240 cases of live births were collected and 2 243 129 cases of which were full-term infants. The multivariate logistic regression model was used to analyze the related factors of low birth weight. Results: The birth weight of 2 394 240 live births, (3 123.49±461.08) g, in Guangxi was approximately normal distribution with a peak distribution to the left. The incidence of low birth weight was 8.05%, and the incidence of macrosomia was 2.07%. The incidence of low birth weight was 10.92% for the puerpera with body mass index (BMI, kg/m²) <18.5, 16.82% for the puerpera with height <145 cm, 8.92% for the puerpera with age <20 years old, 7.67% for the puerpera with age ≥35 years old, and 54.65% for the puerpera with premature birth. The birth weight of 2 243 129 full-term infants, (3 176.01±400.78) g, was approximately normal distribution with a peak distribution to the right. The incidence of low birth weight was 2.97%, and the incidence of macrosomia was 2.19%. The incidence of low birth weight was 4.73% for puerpera with BMI<18.5, 8.17% for puerpera with height<145 cm, 4.83% for puerpera with age <20 years old, and 3.05% for puerpera with age ≥35 years old. The risks of low birth weight [OR (95%CI) value] of pregnant women aged <20, 25-29 and 30-34 years old were 1.31 (1.28-1.35), 0.88 (0.86-0.90) and 0.89 (0.87-0.91) times of those aged ≥35 years old. The risks of low birth weight [OR (95%CI) value] of pregnancy BMI <18.5 and 18.5-23.9 kg/m² group were 1.98 (1.94-2.03) and 1.20 (1.18-1.23) times of those pregnancy BMI ≥24 kg/m². The risks of low birth weight [OR (95%CI) value] of pregnant women′s height (cm)<145, 145-154, 155-159 and 160-164 cm were 4.67 (4.39-4.97), 2.36 (2.29-2.44), 1.58 (1.53-1.63) and 1.22 (1.18-1.26) times of those heights ≥165 cm group. The risks of low birth weight [OR (95%CI) value] of pregnant women′s gestational age <28, 28-31 and 32-36 years old were 136.65 (124.33-150.20), 1 704.37 (1 509.02-1 925.02) and 33.45 (32.98-33.94) times of those gestational age ≥37 years old. Conclusion The incidence of low birth weight of live births was higher in Guangxi from 2016 to 2018. There is a higher risk of low birth weight for younger, older, low height, low BMI and preterm women in Guangxi from 2016 to 2018.

According to the literature review, no cyst of the hip ligamentum teres has been reported. In this study, a 50?year?old female patient was admitted to the hospital because of sprained left hip pain with movement restriction for 15 months. The unilateral hip joint MRI showed cyst of the hip ligamentum teres, which was diagnosed as left hip joint cyst in the outpatient de?partment. Thus, the patient was admitted to the hospital. Physical examination showed that the left hip joint movement was slightly restricted with positive FADDIR test and FABER test. Arthroscopic surgical examination revealed a 1.5 cm×1.0 cm cyst at the lo?cation of the round ligament which was then cleared with a planer knife and radiofrequency. The treatment results were satisfacto?ry. The present study reviewed the literature about anatomical and biomechanical physicochemical properties of the ligamentum teres. The function of the ligamentum teres is important for the hip joint. In diagnosis of hip disease, unilateral hip MRI plays an important role in accurate diagnosis of such diseases. The hip arthroscopy provide a minimal invasive technique in treating cyst of the hip ligamentum teres. With the application of the hip arthroscopy, it will undoubtedly improve the diagnosis and treatment of hip diseases.

Objective To analyze the biological characteristics of Yersinia pestis strains in Haixi Prefecture,Qinghai Province,in order to provide a scientific basis for plague prevention and control in future.Methods Totally 181 strains were separated from variety kinds of host in Haixi Prefecture,Qinghai Province from 1957 to 2011,and these strains were conducted biochemical test,virulence factor evaluation,plasmid analysis,different region (DFR) genotyping,drug and disinfectant resistant genes detection;79 of the 181 strains were examined by toxicity test and classified according to the criteria (minimum lethal dose:MLD≤ 10 000 was velogenic strain,10 000 ＜ MLD ＜ 100 000 was moderate virulence strain,MLD ≥ 100 000 was hypovirulent strain).Results According to six biochemical typing about gelatin candy,rhamnose,maltose,melibiose,glycerin and denitrification,the 181 strains of Yersinia pestis were antique biovar and Qing-Tibet Plateau ecotype.Aproportion of 81.22％ (147/181) of Yersiniapestis strains contained all the four virulence factors (F1,Pst Ⅰ,VW,Pgm).Totally 63.54％ (115/181) of the strains contained 3 kinds of plasmid-6 × 106,45 × 106,and 52 × 106;31.49％ (57/181) of the strains contained 3 kinds of plasmid-6 × 106,45 × 106,and 65 × 106.The strains had 8 genomovars,and were given priority to genomovar 8 (109 strains),secondly,genomovar 32 (33 strains),genomovar 5 (20 strains),genomovar 1b(i4 strains),genomovar 44 (2 strains),genomovar 7 (1 strain),genomovar 37 (1 strain),and genomovar 49 (1 strain).Among the 181 Yersinia pestis strains,strains with genes related to streptomycin resistance,sulfanilamide resistance,beta lactam resistance and disinfectant resistance were not found;and 75 of 79 strains were velogenic strains by toxicity test (MLD ≤ 10 000),accounted for 94.94％ (75/79).Conclusion The strains separated in Haixi Prefecture,Qinghai Province have the characteristics of Qinghai-Tibet Plateau plague's pathogen and have strong toxicity;all strains don't have the characteristics of drug and disinfectant resistance genes.

Objective To establishment a method for detection of multiple drug resistance gene of Yersina pestis using polymerase chain reaction(PCR), to provide a guidance for treatment of plague. Methods According to National Center for Biotechnology Information (NCBI) released sequences of aminoglycoside resistant genes of streptomycin resistant,strB,strA,beta lactam antibiotics resistant genes tem,shv,and ctx-m,sulfamilamide resistant genes sul1, sul2, and sul3, a pair of primers of each gene was designed. DNAs of 282 strains isolated from plague natural foci in Qinghai Province were amplified by PCR using every pair of primers. The products were separated using gel electrophoresis, and the results were visualized through a gel imaging system. The susceptibility of 282 Yersina pestis to streptomycin, sulfamethoxazole and ceftriaxone was tested by drug sensitivity test. Results The PCR amplification results of all samples were negative,and strains with streptomycin,sulfamilamide and beta lactam antimicrobial drug resistance genes were not found. Drug sensitivity test showed that 282 strains were highly sensitive to streptomycin,sulfamethoxazole and ceftriaxone sodium.The diameter of bacteriostasis ring>19,17,21 mm, respectively. Conclusions It is a feasible method to use PCR technology to detect the multiple drug resistance genes of Yersinia pestis. Using this method to systematically monitor the resistance gene of Yersinia pestis is an efficient, economical and practical experimental method, which can provide guidance for the treatment of plague disease.

Objective In order to acquaint with the prevalence of Tibetan sheep plague in this area, we conducted a serum epidemiological investigation of Tibetan sheep plague in Qinghai Province. Methods Indirect hemagglutination assay (IHA) and colloidal gold immunochromatography (GICA) were applied to test serum samples of Tibetan sheep and whole blood samples from jugular vein of Tibetan sheep were collected in 8 Prefectures of Qinghai Province from 2013 to 2016. Results A total of 86 positive Tibetan sheep serum samples with plague F1 antibody were detected by both methods, and the positive rate was 0.68％ (86/12710), the samples collected in Xinghai County Hainan Prefecture had the highest positive rate, which was 5.20％ (27/519). The Haixi Prefecture and Yushu Prefecture were historical epidemic areas, the positive rates were 0.65％(15/2313) and 0.26％(6/2293), respectively. Hainan Prefecture, Guoluo Prefacture and Huangnan Prefecture were newly confirmed epidemic areas, the positive rates were 1.61％ (28/1741), 1.01％ (15/1481), and 1.44％(19/1316), respectively. The antibody titers were 1:20 to 1:5120, the samples collected in Maqin County Guoluo Prefecture had the highest titer, namely 1 :5120. Conclusions In Qinghai Province, Tibetan sheep plague is endemic, and there are outbreaks in some regions. So we have to enhance the Tibetan sheep plague monitoring especially in Marmot plague epidemic area.