The Triceptide Maturase OscB Catalyzes Uniform Cyclophane Topology and Accepts Diverse Gly-Rich Precursor Peptides.

Triceptides are a class of ribosomally synthesized and post-translationally modified peptides defined by an aromatic C(sp2) to Cß(sp3) bond. The Gly-rich repeat family of triceptide maturases (TIGR04261) are paired with precursor peptides (TIGR04260) containing a Gly-rich core peptide. These maturases are prevalent in cyanobacteria and catalyze cyclophane formation on multiple Ω1-X2-X3 motifs (Ω1 = Trp and Phe) of the Gly-rich precursor peptide. The topology of the individual rings has not been completely elucidated, and the promiscuity of these enzymes is not known. In this study, we characterized all the cyclophane rings formed by the triceptide maturase OscB and show the ring topology is uniform with respect to the substitution at Trp-C7 and the atropisomerism (planar chirality). Additionally, the enzyme OscB demonstrated substrate promiscuity on Gly-rich precursors and can accommodate a diverse array of engineered sequences. These findings highlight the versatility and implications for using OscB as a biocatalyst for producing polycyclophane-containing peptides for biotechnological applications.

Substrate Promiscuity of the Triceptide Maturase XncB Leads to Incorporation of Various Amino Acids and Detection of Oxygenated Products.

Triceptides are cyclophane-containing ribosomally synthesized and post-translationally modified peptides. The characteristic cross-links are formed between an aromatic ring to Cß on three-residue Ω1X2X3 motifs (Ω1 = aromatic). Here, we explored the promiscuity of the XYE family triceptide maturase, XncB from Xenorhabdus nematophila DSM 3370. Single amino acid variants were coexpressed with XncB in vivo in Escherichia coli, and we show that a variety of amino acids can be incorporated into the Phe-Gly-Asn cyclophane. Aromatic amino acids at the X3 position were accepted by the enzyme but yielded hydroxylated, rather than the typical cyclophane, products. These studies show that oxygen can be inserted but diverges in the final product formed relative to daropeptide maturases. Finally, truncations of the leader peptide showed that it is necessary for complete modification by XncB.

Protocol for generating mouse morula-like cells resembling 8- to 16-cell stage embryo cells.

Generating cell types with properties of embryo cells with full developmental potential is of great biological importance. Here, we present a protocol for generating mouse morula-like cells (MLCs) resembling 8- to 16-cell stage embryo cells. We describe steps for induction, via increasing Stat3 activation, and the isolation of MLCs. We then detail procedures for segregating MLCs into blastocyst cell fates and how to create embryo-like structures from them. This system provides a stem-cell-based embryo model to study early embryo development. For complete details on the use and execution of this protocol, please refer to Li et al.1.

Functional and Promiscuity Studies of Three-Residue Cyclophane Forming Enzymes Show Nonnative C-C Cross-Linked Products and Leader-Dependent Cyclization.

Enzymes catalyzing peptide macrocyclization are important biochemical tools in drug discovery. The three-residue cyclophane-forming enzymes (3-CyFEs) are an emerging family of post-translational modifying enzymes that catalyze the formation of three-residue peptide cyclophanes. In this report, we introduce three additional 3-CyFEs, including ChlB, WnsB, and FnnB, that catalyze cyclophane formation on Tyr, Trp, and Phe, respectively. To understand the promiscuity of these enzymes and those previously reported (MscB, HaaB, and YxdB), we tested single amino acid substitutions at the three-residue motif of modification (Ω1X2X3, Ω1 = aromatic). Collectively, we observe that substrate promiscuity is observed at the Ω1 and X2 positions, but a greater specificity is observed for the X3 residue. Two nonnative cyclophane products were characterized showing a Phe-C3 to Arg-Cß and His-C2 to Pro-Cß cross-links, respectively. We also tested the leader dependence of selected 3-CyFEs and show that a predicted helix region is important for cyclophane formation. These results demonstrate the biocatalytic potential of these maturases and allow rational design of substrates to obtain a diverse array of genetically encoded 3-residue cyclophanes.

Association between latent classes of dietary patterns and depressive symptoms among firstgrade students from multi ethnic middle schools in Yunnan Province / 中国学校卫生

Objective@#To determine the latent class of dietary patterns and their association with depressive symptoms among first grade students from multi ethnic middle schools in Yunnan Province, so as to provide a reference basis for promoting mental health among border middle school students.@*Methods@#A cluster random sampling involving 8 500 first grade middle school students from 11 counties in Yunnan Province was conducted by a questionnaire survey between October to December 2022. The Children s Depression Inventory (CDI) was used to assess the depressive symptoms and the Food Frequency Questionnaire was used to collect eating behavior data. The latent profile analysis model was used to fit the latent class of dietary patterns among students. The association between the dietary pattern latent class and depressive symptoms was analyzed by Logistic regression.@*Results@#The depressive symptom detection rate among firstgrade middle school students was 28.3%. Prevalence of depressive symptom in girls (30.9%) was higher than boys (25.5%) with a statistically significant difference ( χ 2=29.83, P <0.01). The dietary patterns among first grade middle school students were classified into four latent classes, as follows:class 1 (low consumption of all dietary components), class 2 (high consumption of fruit, milk and dairy products), class 3 (high consumption of vegetables and meat, and low consumption of processed foods) and class 4 (low consumption of milk, dairy products and eggs, and high consumption of processed foods). After adjusting for confounding variables, the class 3 dietary pattern was negatively correlated with depressive symptoms ( OR=0.62, 95%CI =0.52-0.74) and the class 4 dietary pattern was positively correlated with depressive symptoms ( OR= 1.28 , 95%CI =1.05-1.57) ( P <0.05), compared with the class 1 dietary pattern.@*Conclusions@#Multi ethnic first grade middle school students in Yunnan Province follow various dietary patterns. Unhealthy dietary patterns increase the risk of depressive symptoms. The dietary patterns of multi ethnic middle school students in Yunnan Province should be adjusted to promote the establishment of healthy dietary patterns and reduce the risk of depression symptoms in middle school students.

In vitro generation of mouse morula-like cells.

Generating cells with the molecular and functional properties of embryo cells and with full developmental potential is an aim with fundamental biological significance. Here we report the in vitro generation of mouse transient morula-like cells (MLCs) via the manipulation of signaling pathways. MLCs are molecularly distinct from embryonic stem cells (ESCs) and cluster instead with embryo 8- to 16-cell stage cells. A single MLC can generate a blastoid, and the efficiency increases to 80% when 8-10 MLCs are used. MLCs make embryoids directly, efficiently, and within 4 days. Transcriptomic analysis shows that day 4-5 MLC-derived embryoids contain the cell types found in natural embryos at early gastrulation. Furthermore, MLCs introduced into morulae segregate into epiblast (EPI), primitive endoderm (PrE), and trophectoderm (TE) fates in blastocyst chimeras and have a molecular signature indistinguishable from that of host embryo cells. These findings represent the generation of cells that are molecularly and functionally similar to the precursors of the first three cell lineages of the embryo.

Physical fitness evaluation results among students in Yunnan Province in 2019 / 中国学校卫生

Objective@#To analyze physical fitness of students aged 6-22 years old from seven ethnic groups in Yunnan Province, and to provide reference for physical fitness intervention measures.@*Methods@#The nationality, gender, grade, body shape, vital capacity, exercise quality of students were derived from the 2019 Yunnan Student Physical Health Survey Database. Comprehensive physical fitness score was calculated according to the National Student Physical Fitness Standards(revised in 2014). t test, ANOVA, and χ 2 test were used to analyze physical fitness score and level among students with different ethnic groups, gender, and school stages.@*Results@#The average comprehensive score of physical fitness among students from 7 ethnic groups in Yunnan Province was (70.02±9.69）, with the pass rate being 88.91%. The proportion of excellent was 0.93%, good was 17.90%, pass 70.09 %, and failed was 11.09%. Physical fitness score was highest in BMI (94.99 points), followed by 50 meter running (74.13 points), sitting forward bend (72.63 points), endurance running (70.43 points), standing long jump (67.77 points), sit ups ( 65.71 points) , 1 minute skipping rope (65.25 points), vital capacity (62.97 points), pull up (29.04 points). Physical fitness score and pass rate and evaluation level varied significantly by ethnicity and school stage( F =293.53，452.85， χ 2/ χ 2 trend =466.65， 412.57 ； 1 553.22 ，1 045.36， P <0.01).@*Conclusion@#The excellent rate of physical fitness among students in Yunnan Province is relatively low. Physical fitness promotion requires specific guidance and training based on ethnicity and school stage.

Discriminante analysis of risk factors Nomograms of myopia in children and adolescents in Yunnan Province / 中国学校卫生

Objective@#To explore the related factors of myopia among children and adolescents in Yunnan Province, and to predict and evaluate the influencing factors, so as to provide a scientific theoretical basis for the prevention and control of myopia.@*Methods@#From March 9 to 14, 2023, 848 students from 6 primary and secondary schools in Dali and Lijiang of Yunnan Province were selected by multi stage stratified random cluster sampling method for visual acuity detection and questionnaire survey on myopia related factors. Multivariate Logistic regression analysis was used to establish a Nomogram prediction model for the selected influencing factors.@*Results@#The overall myopia rate of the respondents was 68.3%, the myopia rate of boys (63.4%) was lower than that of girls (72.9%), and the myopia rate of primary school students (46.7%) was lower than that of junior high school students (81.1%), and the difference was statistically significant（ χ 2=8.71, 108.07, P <0.05). Daily eye exercises, activities outside the teaching building during recess, having daily sleep time of 7-9 and >9 h, having both parents without myopia were negatively correlated with the occurrence of myopia in children and adolescents in Yunnan Province ( OR=0.64, 0.63, 0.56, 0.28, 0.48, P < 0.05 ). The reading and writing time after school ≥3 h per day and parents unrestricted time to play video games were positively correlated with myopia ( OR=1.94, 1.78, P <0.05). Based on the influencing factors, a Nomogram prediction model was established to quantitatively evaluate the risk of myopia. The results showed that greater risk for myopia was associated with sleep duration, parental history of myopia, and the time spent reading and writing after school every day.@*Conclusion@#Both genetic factors and environmental factors are related to myopia in children and adolescents. The prediction model of nomogram is beneficial for screening high risk factors of myopia and taking corresponding prevention and treatment measures.

Secular trends of the prevalence of emaciation, overweight, and obesity among school-aged children in Yunnan province, 1985-2019: A serial cross-sectional surveillance study in China.

Objective: To understand the trends of nutrition in children and adolescents, which may further help to prevent and control chronic diseases in younger ages. Methods: The Chinese National Surveys on Students' Constitution and Health (CNSSCH) in Yunnan is a survey of growth conditions, physical fitness, and health status of students in Yunnan and uses a series of complex multistage stratified sampling of seven prefectures consisting of 16 counties. Sampling schools were held constant over 35 years. The participants were randomly selected among 7-18 aged students. We used data from 1985, 1991, 2000, 2005, 2010, 2014, and 2019 CNSSCH of Yunnan. According to body mass index (BMI) criteria of National Working Group for Obesity in China (WGOC-BMI criteria), a participant's nutrition (emaciation, overweight or obesity) was defined. This study is based on survey data from 129,520 participants in 1985 (n = 14,683), 1991 (n = 4,894), 1995 (n = 6,673), 2000 (n = 9,751), 2005 (n = 23,461), 2010 (n = 22,889), 2014 (n = 23,003) and 2019 (24,166). Results: Since 1985, the trends of emaciation over 35 years were decreasing. Regardless of gender, area, and age, the prevalence of obesity and overweight were increased. The average annual growth rate of overweight and obesity was quicker in rural areas and boys than in urban areas and girls. In Yunnan, emaciation, overweight, and obesity disparity in children were common phenomena, with differences in areas and gender. Conclusion: Children in Yunnan faced the triple burden of malnutrition (emaciation, overweight, and obesity). We should take comprehensive policies and effective intervention measures to decrease the rate of nutrition deficiencies in school-aged children.

[Relationship between sugary food intake and myopia in 11-14 years old Chinese children in 2019-2021].

OBJECTIVE: To investigate the relationship between the intake of sugary foods and the occurrence and development of myopia in children aged 11-14 in China. METHODS: In the 28 urban and rural survey sites in 14 provinces that implemented the "China Children's Nutrition and Health System Survey and Application for 0-18 Years Old" project, a multi-stage stratified random cluster sampling method was adopted, and finally 12 397 adolescent children aged 11 to 14 were selected in the analysis. Demographic characteristics, myopia information and the intake of sugary food(cakes, preserved fruits, candies, chocolates and ice cream) were collected through questionnaires. Multifactor Logistic regression was used to analyze the relationship between sugary food intake and myopia in children. RESULTS: The median daily intake of sugary foods(cakes, preserved fruits, candies, chocolates and ice cream)of 11-14 year old boys and girls in China was 11.4 g and 11.2 g respectively, 33.9% of boys and 34.2% of girls consumed ≥22 g of sugary food every day. The myopia rates of boys with intakes of <2 g, 2-21 g and ≥22 g were 36.0%, 39.2% and 41.6%, and girls' myopia rates were 45.9%, 51.8% and 55.1%. The result of Logistic regression analysis showed that after controlling for confounding factors such as age, gender, region, weekly high-intensity physical activity time, daily screen time, daily sleep time and daily intake of sugary beverages, compared with boys whose daily intake of sugary food was less than 2 g, the risk of myopia for boys whose daily intake of sugary food reached 2-21 g and ≥22 g was 1.18 and 1.23 times, for girls whose daily intake was less than 2 g, the risk of myopia was 1.27 times and 1.38 times for girls whose intake reached 2-21 g and ≥22 g(P<0.05). No matter whether confounding factors were controlled or not, there was no correlation between the intake of sugary foods and the degree of myopia(P>0.05). CONCLUSION: The consumption of sugary food such as cakes, preserved fruits, candies, chocolates and ice cream among children aged 11 to 14 in China is common, and there is a certain degree of positive correlation with the prevalence of myopia, but no correlation is observed with the degree of myopia.

Two Birds with One Stone: Concurrent Ligand Removal and Carbon Encapsulation Decipher Thickness-Dependent Catalytic Activity.

A carbon shell encapsulating a transition metal-based core has emerged as an intriguing type of catalyst structure, but the effect of the shell thickness on the catalytic properties of the buried components is not well known. Here, we present a proof-of-concept study to reveal the thickness effect by carbonizing the isotropic and homogeneous oleylamine (OAm) ligands that cover colloidal MoS2. A thermal treatment turns OAm into a uniform carbon shell, while the size of MoS2 monolayers remains identical. When evaluated toward an acidic hydrogen evolution reaction, the calcined MoS2 catalysts deliver a volcano-type activity trend that depends on the calcination temperature. Rutherford backscattering spectrometry and depth-profiling X-ray photoelectron spectroscopy consistently provide an accurate quantification of the carbon shell thickness. The same variation pattern of catalytic activity and carbon shell thickness, aided by kinetic studies, is then persuasively justified by the respective limitations of electron and proton conductivities on the two branches of the volcano curve.

Epidemiological and clinical characteristics of the largest COVID-19 outbreak along the China-Myanmar border in Ruili City, Yunnan Province, China.

Background: Imported COVID-19 patients posed great challenges to border areas' COVID-19 control. However, research was scarce to reveal epidemiological characteristics of COVID-19 in border areas. This study aimed to explore the detailed transmission chains, and reveal epidemiological and clinical characteristics of the largest COVID-19 outbreak caused by Delta variant of concern (VOC) occurred in the China-Myanmar border area. Methods: During the outbreak from July to September, 2021 in Ruili City, Yunnan Province, China, epidemiological investigation data and clinical-related data pertaining to confirmed COVID-19 patients were collected. Patients' contact history data and viral gene sequencing were used for inference of transmission chains. Sociodemographic and epidemiological characteristics, cycle threshold (Ct) value, and antibodies level were compared between patients who were vaccinated against COVID-19 or not. Results: A total of 117 COVID-19 patients were confirmed during the outbreak, among which 86 (73.5%) were breakthrough infections. These patients evenly split between Chinese and Myanmar people (50.4% vs. 49.6%). Most of these patients were mild (45.3%) or moderate (48.7%) infections with no death reported. Multi-source of infection led to 16 transmission chains with a maximum of 45 patients in one chain. Patients vaccinated against COVID-19 before infection had relatively higher antibodies (IgM and IgG) levels and more rapid response to infection than non-vaccinated patients (p < 0.05). Conclusion: Land border areas have greater risks of imported COVID-19 and more complicated epidemics. It should be cautious in formulating entry and exit requirements for border areas. The immune effect of COVID-19 vaccines and related mechanism should be further explored.

Evaluation of stroke health education for primary school students in Dali, China.

Objectives: To provide us with some evidence to develop more targeted stroke intervention strategies, improve the health awareness of stroke among children, and advocate the health promotion campaign of "small hands holding big hands" among parents and children, we have conducted a health education program on stroke among primary school students in Dali. Methods: This study has applied stratified random cluster sampling in Dali of Yunnan, China. We compared the improvement of students' knowledge of stroke before and after our health education program in primary school students of Dali in October 2020. Data were collected through 3 rounds of survey by using the same questionnaire. Results: There were 215 participants aged 7-8 years old sampled in the first phase of the study and 145 participants in the follow-up study. The knowledge of stroke among the participants was relatively low in the pre-intervention survey. After the health education, all the indicators on stroke knowledge were improved. The correct rates in stroke definition, sequelae, and "1-2-0" identification were increased from 0 to 66.05%, to 53.95% and 64.19%, respectively, in both pre-intervention and post-intervention surveys. The correct rate of stroke knowledge was about 4.83-92.41% 3 months after the intervention. The mean score of the questionnaire was 4.25 ± 0.19 in the pre-intervention survey, and that was 15.85 ±0.27 in the post-intervention one. The mean score was 14.02 ± 0.28 post-3-month test. The score in the 3-month survey after the intervention was 11.55% lower than that in the post-intervention score. Conclusions: The effect of stroke-related knowledge in the health education program for children is improved significantly and this can last for 3 months but it also had attenuation. We should repeat pertinent health education among students.

Exploring the Bridge Cases' Role in the Transmission of the SARS-CoV-2 Delta Variant - Ruili City, Yunnan Province, China, July-September 2021.

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant has proved to have increased transmissibility, and mutations that can cause partial immune escape, which makes its transmission more insidious. WHAT IS ADDED BY THIS REPORT?: This study showed that probable cases who had negative results in nucleic acid testing but had positive IgM test result and/or IgG test value of over 20 S/CO in antibodies testing, might serve as bridges in the Delta variant's transmission chain. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?: In border inspection and quarantine, tests for SARS-CoV-2 IgM and IgG antibodies should be strengthened alongside nucleic acid tests to prevent probable cases with transmission potential from crossing the land border into China. In contact tracing investigations, the bridging role of probable cases should be considered to reconstruct the transmission chain.

Prevalence trends of hypertension among 9-17 aged children and adolescents in Yunnan, 2017-2019: a serial cross-sectional surveillance survey.

BACKGROUND: We aim to describe the prevalence and trends of hypertension among 9-17 school-aged students from 2017 to 2019 in Yunnan, China. METHODS: We conducted a cross-sectional study by using data from the Students' Health Surveillance Surveys of 2017, 2018 and 2019 in Yunnan. The Students' Health Surveillance Surveys in Yunnan collected date on physical fitness and health status of students in Yunnan through multistage-stratified sampling in 3 prefectures. In each prefecture, the study population were classified by gender and region (urban or rural), and each group had an equal size. Diagnosing criteria of hypertension was set with reference to Chinese age-specific and height-specific blood pressure (BP), to identify the abnormal status of boys and girls separately. ANOVA test was adopted to measure the differences in the mean BP stratified by gender, age, prefecture and area, and Chi-square test was used to compare the percentages of hypertension in different areas. For comparability, the age-standard and gender-standard population prevalence was calculated by directly using China Census in 2010 as a standard population. Totally 24,890 participants aged 9-17 years were included in this study. RESULTS: From 2017 to 2019, there were 24,872 students completed physical examinations and included in the analysis, of which 3288 were diagnosed with hypertension. The total prevalence of hypertension was 13.72, 12.49 and 13.45% among 9-17 years school-aged population in Yunnan, respectively. The total age-standardized hypertension prevalence trended to decrease from 13.82 to 13.48%. For urban population, the age-standardized hypertension prevalence decreased slightly from 11.24 to 10.13%. While, for rural population, it increased from 17.58 to 19.16%. The average annual growth rate in rural population was 0.53%. CONCLUSIONS: From 2017to 2019, there was a significant and continuous increase in the prevalence of hypertension in 9-17 years school-aged population in Yunnan. Hypertension is epidemic among children and adolescents in Yunnan. We should take effective and comprehensive intervention measures to reduce its prevalence among school-aged children.

[Study on malnutrition status among Wa ethnicity children and adolescents in Lingcang prefecture, Yunnan province].

OBJECTIVE: To analyze the malnutrition status among children and adolescents of Wa ethnicity in Lincang prefecture, Yunnan province from 2005 to 2014, and to provide evidence for the improvement of the situation. METHODS: From 2005 to 2014, children and adolescents aged 7 to 18, from 19 primary and secondary schools in Cangyuan county of Lincang prefecture, Yunnan province, were chosen, using the multistage-stratified-random cluster sampling method, to receive physic examination. WHO-2006 standard was used. Situation related to the rate of growth retardation and malnutrition among students was analyzed, from 2005 to 2014. Data was from the National Student Physical Health Research Project. From 2000 to 2014, trends on nutrition development among these students were also studied. RESULTS: The rates related to growth retardation among 7-18 years-old Wa boys in 2005, 2010 and 2014 were 45.61%, 52.36% and 35.85%, with the rates of thinness as 1.44%, 0.76% and 1.36% , respectively. Rates on malnutrition were 52.35% , 56.01% and 41.13% , respectively. Rates related to growth retardation among 7-18 years-old Wa girls were 42.03%, 47.41% and 33.06%, respectively, with rates of thinness as 0.91%, 0.68% and 0.83%, respectively. The rates on malnutrition were 46.13%, 49.77% and 35.56%, respectively. From year 2005 to 2014, spurt on height growth of boys and girls were among the 13-14 years-old and 9-10 years-old, respectively. Girls were 4 years earlier, entering the sudden increase in the peak age than boys. Sex difference on height among the 18 years-old Wa youngsters were 11.99, 9.34 and 11.38 cm in 2005, 2010 and 2014, respectively. CONCLUSION: Malnutrition status of retardation on growth among Wa children and adolescents remained quite serious.

Rural residents in China are at increased risk of exposure to tick-borne pathogens Anaplasma phagocytophilum and Ehrlichia chaffeensis.

As emerging tick born rickettsial diseases caused by A. phagocytophilum and E. chaffeensis, anaplasmosis and ehrlichiosis have become a serious threat to human and animal health throughout the world. In particular, in China, an unusual transmission of nosocomial cases of human granulocytic anaplasmosis occurred in Anhui Province in 2006 and more recent coinfection case of A. phagocytophilum and E. chaffeensis was documented in Shandong Province. Although the seroprevalence of human granulocytic anaplasmosis (former human granulocytic ehrlichiosis, HGE) has been documented in several studies, these data existed on local investigations, and also little data was reported on the seroprevalence of human monocytic ehrlichiosis (HME) in China. In this cross-sectional epidemiological study, indirect immunofluorescence antibody assay (IFA) proposed by WHO was used to detect A. phagocytophilum and E. chaffeensis IgG antibodies for 7,322 serum samples from agrarian residents from 9 provinces/cities and 819 urban residents from 2 provinces. Our data showed that farmers were at substantially increased risk of exposure. However, even among urban residents, risk was considerable. Seroprevalence of HGA and HME occurred in diverse regions of the country and tended to be the highest in young adults. Many species of ticks were confirmed carrying A. phagocytophilum organisms in China while several kinds of domestic animals including dog, goats, sheep, cattle, horse, wild rabbit, and some small wild rodents were proposed to be the reservoir hosts of A. phagocytophilum. The broad distribution of vector and hosts of the A. phagocytophilum and E. chaffeensis, especially the relationship between the generalized susceptibility of vectors and reservoirs and the severity of the disease's clinical manifestations and the genetic variation of Chinese HGA isolates in China, is urgently needed to be further investigated.

Anaplasma phagocytophilum infection in domestic animals in ten provinces/cities of China.

A nationwide epidemiologic investigation of domestic animal infections has been conducted in nine provinces and one city during 2007-2010. Serum samples from a total of 707 goats, 433 cattle, and 219 dogs were collected for detecting Anaplasma phagocytophilum IgG antibody by immunofluorescence assays and the average seroprevalences were 10.05% for dogs, 3.82% for goats, and 0.69% for cattle, respectively. A total of 472 goats, 201 cattle, 102 dog blood clots, and 1,580 ticks were collected for polymerase chain reaction (PCR) amplifying A. phagocytophilum 16S rRNA genes and the PCR-positive rates were 26.69% for goats, 23.38% for cattle, and 10.89% for dogs. Six species were identified and the average PCR-positive rates were 58.3% for Dermacentor silvarum, 43.9% for Haemaphysalis longicornis, 12.5% for Ixodes persulcatus, 7.5% (3 of 40) for Boophilus microplus, and 5.2% for Rhipicephalus sanguineus, respectively. The evidence in the study indicated the zoonotic Rickettsia is highly prevalent in China.

Spotted fever group Rickettsia in Yunnan Province, China.

Information about spotted fever group (SFG) rickettsiae in southern China remains sparse. A specific and sensitive real-time PCR assay for detection of SFG rickettsiae was established and used to detect the prevalence rate of SFG rickettsiae in Yunnan Province, China. The limit of detection (LOD) of our real-time PCR was 200 copies per reaction, which is more sensitive than the previously developed nested PCR assays for Rickettsia. We tested 265 blood samples (127 goats, 78 dogs, and 60 cattle) collected from Yunnan Province using the real-time PCR assay and revealed that the prevalence of SFG rickettsiae among dogs, cattle, and goats were 14.10%, 23.33%, and 24.41%, respectively. The SFG rickettsiae detected in animals in Yunnan Province were classified into two genotypes: a unique group that is different from all known SFG rickettsiae species, and R. heilongjiangensis.