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Background: Obesity is highly prevalent worldwide. More and more studies have been conducted on the relationship between H. pylori infection and obesity or overweight. But the relationship between them is controversial in the literatures and there is no comprehensive evidence for the correlation. Aim: To evaluate the prevalence of H. pylori infection in Chinese adult subjects who received routine physical examinations and the relationship between H. pylori and obesity. Methods: Literatures on H. pylori infection and obesity in Chinese population were searched in online databases. Relevant data were extracted independently by two researchers and meta-analysis was performed by using Review manager 5.3 software. Results: 22 articles were selected with a total sample size of 178033. The pooled prevalence of H. pylori was 42% (95%CI: 37% to 47%) and mean difference of BMI between subjects with and without H. pylori infection was 0.94 (95%CI: -0.04 to 1.91). 9 eligible studies with 27111 subjects were used to calculated pooled OR value because they contained obesity groups. The OR value showed that H. pylori-positive subjects tended to be obese at a risk of 1.20 (95% CI: 1.13 to 1.28). Conclusion: In China, obesity has association with H. pylori infection. H. pylori infection may be one of the risk factors for obesity. [ABSTRACT FROM AUTHOR]

Leeches are frequently used in traditional Chinese medicine. However, they are potentially hazardous to human and animal health by transmitting several pathogens. Studies of diseases transmitted by leeches are scarce. The purpose of this study was to analyze the pathogens carried in pond-farmed medicinal leech in China. Leeches were collected from 6 farms in Hubei Province in central China. DNA was extracted from the internal organ of leeches to analyze the origin of blood meal. Leech genera were confirmed through amplification of 18S rRNA and mitochondrial gene cytochrome oxidase I (COI) gene by PCR and host animal species were identified through amplification of mitochondrial cytochrome b gene. Species of Ehrlichia in the leech specimens were screened with PCR using specific primers. PCR amplification and DNA sequencing showed that 620 leeches were Hirudinaria sp. Ehrlichia DNA was detected in 39 specimens from 2 farms. We obtained a total of 65 sequences of the cytB gene from 620 leech internal organ samples including sequences of human (n = 5), rat (n = 1), domestic pig (n = 10), duck (n = 23), goose (n = 12) and buffalo (n = 14). Phylogenetic analysis of the rrs and groEL gene sequences showed that Ehrlichia detected in the study were closely related to Ehrlichia sp. in ticks from Korea and Japan. To the best of our knowledge, this is the first report on Ehrlichia DNA being detected from leeches. Our findings provided new data on Ehrlichia spp. and farmed leech species in China. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to describe the patients’ reasons for encounter (RFE) and health problems managed by general practitioners (GPs) in the rural areas of Beijing to provide evidences for health services planning and GPs training. Methods: This study was conducted at 14 community health service centers (CHSCs) in 6 suburban districts of Beijing, using a multistage sampling method. A total of 100 GPs was selected from the study sites. A self-designed data collection form was developed on the basis of Subjective-Objective-Assessment-Plan (SOAP), including patient characteristics, RFEs, health problems, interventions, and consultation length. Each GP recorded and coded their 100 consecutive patients’ RFEs and health problems with the International Classification of Primary Care, 2nd version (ICPC-2). Descriptive statistics were employed to describe the distribution of RFE and health problems. Student t-test and analysis of variance were used to compare the differences of mean number of RFE or health problems per encounter by patient characteristics. Results: A total of 10,000 patient encounters with 13,705 RFEs and 15,460 health problems were recorded. The RFEs and health problems were mainly distributed in respiratory, circulatory, musculoskeletal, endocrine, metabolic and nutritional, and digestive systems. Cough and hypertension were the most common RFE and health problem, respectively. With increased ages, the mean number of RFEs decreased and the mean number of health problems increased. Patients with Beijing medical insurance had less RFEs and more health problems than those in other cities (p<0.001). Patients who had visited the CHSC previously and signed contracts with the GP team had more health problems than those who had not (p<0.001). Conclusions: These findings present a view of patients’ demands and work contents of GPs in Beijing rural areas and can provide reference for health services planning and GPs training. [ABSTRACT FROM AUTHOR]

Equine hepacivirus (EqHV), equine pegivirus (EPgV) and Theiler’s disease-associated virus (TDAV) are three novel equine viruses in the family Flaviviridae. EqHV and EPgV have been identified to circulate in the equine population worldwide, whereas TDAV has not been detected in equines since the first reported case. To date, no studies have focused on investigating EqHV, EPgV and TDAV in commercial equine sera or equine blood products in China. Considering the potential threat of EqHV, EPgV and TDAV to biosecurity and considering their possible influences on research results, equine sera for cell culture propagation and pregnant mare serum gonadotropin (PMSG) were purchased from different companies in China and investigated for EqHV, EPgV and TDAV in this study. By performing nested PCR or two rounds of PCR targeting the viral NS3 gene, four serum samples were confirmed to be EqHV-, EPgV-, or TDAV-RNA positive; all of the PMSG samples were negative for these three viruses. Subsequent sequencing results indicated that the serum samples contained multiple viral variants of EqHV, EPgV or TDAV, and a genetic analysis based on the partial NS3 gene of the three equine viruses was performed. Our study is the first to confirm the presence of EqHV, EPgV and TDAV in equine sera for cell culture propagation that is commercially available in China and provides the first demonstration of the presence of TDAV in China. [ABSTRACT FROM AUTHOR]

In China, food safety problems have occurred frequently in the past ten years, causing great concern for the public. Adolescents, with higher exposure to problematic food, represent a unique target for interventions aimed at risk reduction. To understand their food safety knowledge, attitude and practice, a cross-sectional survey using paper questionnaire was carried out among 4,220 students (median age of 14 years, 50.3% females) from nine secondary schools in 3 districts of Beijing. The findings showed that the majority of respondents (42.0%) had a high knowledge level. Significant association was found between food safety knowledge score (median = 11, IQR:9–13) and demographic characteristics of region, school type, residence type, habit of smoking and alcohol use, academic record and parents’ education background. In terms of attitude and practice, only 17% of those surveyed regarded China’s food safety situation as good, 53.6% regarded it as worrying; almost all students (96.5%) did pay attention to food safety; 95.3% of the students had worried about the safety of the food provided by the small restaurants and street peddlers, but in reality, as many as 69.4% often or occasionally bought food from peddlers around their campuses and nearly half continued the consumption of such food in spite of worrying about its safety problems. Overall, the food safety knowledge among Beijing secondary school students was relatively good. They did not show much confidence in the country’s food safety situation, but many aware of the safety issues did not bother to change or take action. The study suggests that more systematic and targeted education on food safety is necessary for this age group. [ABSTRACT FROM AUTHOR]

Ureaplasma spp. have gained increasing recognition as pathogens in both adult and neonatal patients with multiple clinical presentations. However, the clonality of this organism in the male population and infertile couples in China is largely unknown. In this study, 96 (53 U. parvum and 43 U. urealyticum) of 103 Ureaplasma spp. strains recovered from genital specimens from male patients and 15 pairs of infertile couples were analyzed using multilocus sequence typing (MLST)/expanded multilocus sequence typing (eMLST) schemes. A total of 39 sequence types (STs) and 53 expanded sequence types (eSTs) were identified, with three predominant STs (ST1, ST9 and ST22) and eSTs (eST16, eST41 and eST82). Moreover, phylogenetic analysis revealed two distinct clusters that were highly congruent with the taxonomic differences between the two Ureaplasma species. We found significant differences in the distributions of both clusters and sub-groups between the male and female patients (P < 0.001). Moreover, 66.7% and 40.0% of the male and female partners of the infertile couples tested positive for Ureaplasma spp. The present study also attained excellent agreement of the identification of both Ureaplasma species between paired urine and semen specimens from the male partners (k > 0.80). However, this concordance was observed only for the detection of U. urealyticum within the infertile couples. In conclusion, the distributions of the clusters and sub-groups significantly differed between the male and female patients. U. urealyticum is more likely to transmit between infertile couples and be associated with clinical manifestations by the specific epidemic clonal lineages. [ABSTRACT FROM AUTHOR]

Delayed diagnosis of HIV infection is associated with advanced immunosuppression and increased risk of onward transmission. Little data exists regarding factors associated with diagnostic delays among patients presenting with advanced HIV disease in China. Medical records of patients with HIV/AIDS hospitalized at a 2000-bed tertiary hospital in Beijing, China between 1997 and 2012 were retrospectively reviewed. Demographic and clinical data of patients newly diagnosed with HIV at the hospital were abstracted. Patient characteristics, disease parameters, and the time interval between the first medical visit and the visit leading to HIV diagnosis were compared among three periods: 1997–2002, 2003–2008 and 2009–2012. Chi-square, Kruskal-Wallis and logistic regression analyses were used as appropriate. A quarter of patients (72/279) were newly diagnosed with HIV at the hospital, consisting of 11, 29 and 32 patients in 1997–2002, 2003–2008 and 2009–2012 respectively. The median time delay between the first medical visit and the visit leading to HIV diagnosis decreased over time from 91 days among patients diagnosed before 2002, to 75 days between 2003 to 2008, and 39 days after 2009 (p = 0.036). However, the median CD4+T cell count at diagnosis was 26 cells/μL [interquartile range 3–132 cells/μL] in 1997–2002, and remained unchanged across time intervals. Forty-one (57%) patients had AIDS-defining conditions and Pneumocystis jiroveci pneumonia was the most common opportunistic infection (31 cases). These results reveal persistent missed opportunities for timely HIV testing among patients with advanced disease. Strategies for promoting early HIV testing in healthcare settings are needed in China. [ABSTRACT FROM AUTHOR]

The increasing complexity and diversity of the human immunodeficiency virus-1 (HIV-1) infections challenge the disease control and anti-retrovirus treatment in China. The infection stages and molecular characteristics of HIV-1 from infected Chinese blood donors were examined to shed light on the HIV genotype distribution and the status of drug resistance mutations (DRMs) in the changing HIV epidemic in China. Western blot (WB) confirmed HIV-1 positive plasma samples were collected from blood donors at five Chinese blood centers from April 16, 2012, through June 30, 2014. The HIV infection stages were determined using the Lag-avidity assay. HIV Pol regions including whole protease and partial reverse transcriptase (RT) were amplified and sequenced to establish the profile of genotype distribution and drug resistance mutations (DRMs). Viral loads were determined using the ROCHE COBAS system. Of the 259 HIV-1 positive samples tested by the Lag-avidity assay, 23.6% (61/259) were identified as recent infections. A total of 205 amplified sequences displayed the following genotype distributions: circulating recombinant form (CRF) 07_BC (61.5%), CRF08_BC (8.3%), CRF01_AE (20%), B (6.3%), and 01B (3.9%). There was no significant difference in genotype distribution between recent and long-term infections. 31 DRMs were identified from 27 samples including four protease inhibitors (PIs) accessory DRMs, two PIs major DRMs (M46I), two nucleoside RT inhibitors DRMs (K219R and K70Q), and 23 nonnucleoside RT inhibitors DRMs. 27 samples had DRMs, yielding a drug resistance prevalence of 13.2% (27/205). Our findings provide important information for developing strategies for comprehensive HIV control and improving anti-retroviral treatment in China. [ABSTRACT FROM AUTHOR]

Objective: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by a novel bunyavirus-SFTSV. The seroprevalence of anti-SFTSV antibodies including immunoglobulin G (IgG) and immunoglobulin M (IgM), specific to SFTSV in the general population has been investigated in various epidemiological studies with inconsistent results. Here, we clarify this discrepancy and reach a more comprehensive result by mean of a meta-analysis. Methods: All relevant articles were searched in the electronic databases (PubMed, Web of science, Embase, Chinese National Knowledge Infrastructure database, Chinese Wanfang database) up to November 2016. The pooled seroprevalence and 95% confidence intervals (95% CIs) were calculated by random- or fixed- model on the basis of heterogeneity. Results: In total, 21 studies containing 23,848 blood samples from 7 provinces were included in this meta-analysis. The minimum and maximum reported seroprevalences of SFTSV among humans in China were 0.23% and 9.17%, respectively. The overall pooled seroprevalence of SFTSV antibodies was 4.3% (95%CI: 3.2%-5.5%). The pooled prevalence was 5.9% (95%CI: 4.7%-7.0%) in Zhejiang province, 4.9% (95%CI: 4.1–5.8%) in Anhui province, 3.9% (95%CI: 1.3%-6.4%) in Shandong province, and 0.7% (95%CI: 0.2%-1.1%) in Jiangsu province. Stratified by occupation, the pooled prevalence of farmer was 6.1% (95%CI: 3.4%-8.9%) and others (mainly are students) was 3.3% (95%CI: 2.4%-4.2%). Additionally, seroprevalence of SFTSV in people who lived in the same village with the patient were higher than that of people who lived in a different village. Seropositive rates in sampling years after 2012 were higher than that before 2012. The prevalence of SFTSV did not differ by age or gender. Sensitive analysis by omitting one study at a time indicated the results of the pooled seroprevalence were robust. Conclusions: Seroprevalence of SFTSV among healthy population in central and eastern China is high. Surveillance efforts on mild or asymptomatic infections among endemic persons are needed. [ABSTRACT FROM AUTHOR]

Bartonella species are emerging human pathogens. Bats are known to carry diverse Bartonella species, some of which are capable of infecting humans. However, as the second largest mammalian group by a number of species, the role of bats as the reservoirs of Bartonella species is not fully explored, in term of their species diversity and worldwide distribution. China, especially Northern China, harbors a number of endemic insectivorous bat species; however, to our knowledge, there are not yet studies about Bartonella in bats in China. The aim of the study was to investigate the prevalence and genetic diversity of Bartonella species in bats in Northern China. Bartonella species were detected by PCR amplification of gltA gene in 25.2% (27/107) bats in Mengyin County, Shandong Province of China, including 1/3 Rhinolophus ferrumequinum, 2/10 Rhinolophus pusillus, 9/16 Myotis fimbriatus, 1/5 Myotis ricketti, 14/58 Myotis pequinius. Phylogenetic analysis showed that Bartonella species detected in bats in this study clustered into ten groups, and some might be novel Bartonella species. An association between Bartonella species and bat species was demonstrated and co-infection with different Bartonella species in a single bat was also observed. Our findings expanded our knowledge on the genetic diversity of Bartonella in bats, and shed light on the ecology of bat-borne Bartonella species. [ABSTRACT FROM AUTHOR]

Introduction: China is amidst a sexual revolution, with changing sexual practices and behaviors. Sex–seeking mobile phone applications (gay apps) that allow multiple people to meet up quickly may facilitate group sex. This study was therefore undertaken to evaluate group sex among Chinese MSM and to better understand factors associated with group sex. Methods: An online survey was conducted from September-October 2014, collecting data on socio-demographics, sexual behaviors, use of gay apps and occurrence of group sex among Chinese MSM. Univariate and multivariable logistic regressions were used to compare group sex and non-group sex participants. Results: Of the 1,424 MSM, the majority were under 30 years old (77.5%), unmarried (83.9%), and were gay apps users (57.9%). Overall, 141 (9.9%) participants engaged in group sex in the last 12 months. Multivariate analyses showed that men living with HIV, engaged in condomless anal intercourse with men, and used gay apps were more likely to engage in group sex, with adjusted ORs of 3.74 (95% CI 1.92–7.28), 2.88 (95% CI 2.00–4.16) and 1.46 (95% CI: 1.00–2.13), respectively. Among gay app users, the likelihood of group sex increases with the number of sex partners and the number of sex acts with partners met through a gay app. Conclusions: Chinese MSM who engage in group sex are also more likely to engage in other risky sexual behaviors, and gay app use may facilitate group sex. Further research is needed among MSM who engage in group sex in order to target interventions and surveillance. [ABSTRACT FROM AUTHOR]

Noroviruses (NoVs) are the leading cause of gastroenteritis outbreaks in humans worldwide. Since late 2012, a new GII.4 variant Sydney 2012 has caused a significant increase in NoV epidemics in several countries. From November of 2012 to January of 2013, three gastroenteritis outbreaks occurred in two social welfare homes (Outbreaks A and B) and a factory (Outbreak C) in Shenzhen city of China. Feces and swabs were collected for laboratory tests for causative agents. While no bacterial pathogen was identified, all three outbreaks were caused by NoVs with detection rates of 26.2% (16/61) at Outbreak A, 35.2% (38/108) at Outbreak B), and 59.3% (16/27) at Outbreaks C. For Outbreak B, 25 of the 29 symptomatic individuals (86.2%) and 13 of the 79 asymptomatic individuals (16.5%) were found NoV-positive. For Outbreak C, an asymptomatic food handler was NoV-positive. All thirteen NoV sequences from the three outbreaks were classified into genogroup II and genotype 4 (GII.4), which we identified to be the GII.4 Sydney 2012 variant. The genome of two isolates from Outbreaks A and B were recombinant with the opening reading frame (ORF) 1 of GII.4 Osaka 2007 and ORF2 and 3 of the GII.4 New Orleans. Our study indicated that the GII.4 Sydney 2012 variant emerged and caused the outbreaks in China. [ABSTRACT FROM AUTHOR]

The objective of this study was to extend our previous research and to further characterize the humoral immune responses against HIV-1 p24, gp41 and the specific peptides carrying the immunodominant epitopes (IDEs) that react with human serum samples from HIV-1-infected individuals in China. We found that the majority (90.45%, 180/199) of the samples did not react with any of the three HIV-1 p24 peptides carrying IDEs, but did react with the recombinant full-length p24, suggesting that these samples tested in China were primarily directed against the conformational epitopes of HIV-1 p24. In contrast, 84.54% (164/194) of the samples reacted with at least one HIV-1 linear gp41 peptide, in particular the gp41-p1 peptide (amino acids 560–616). Both recently and long-term HIV-1-infected individuals displayed similar humoral immune responses against the recombinant gp41. However, samples from long-term HIV-1-infected subjects but not from recently infected subjects, showed a very strong reaction against the gp41-p1 peptide. The different response patterns observed for the two groups against the gp41 and the peptide gp41-p1 were statistically significant (P<0.01, Chi-square test). These results have direct relevance and importance for design of improved HIV-1 p24 detection assays and the gp41- based immunoassay that can be used to reliably distinguish recent and long-term HIV-1 infection. [ABSTRACT FROM AUTHOR]

Background: Antiretroviral therapy (ART) and condom use have been proven to reduce the risk of sexual transmission of human immunodeficiency virus (HIV) among HIV sero-different couples, but its full implementation remains a challenge. This study aims to assess HIV seroconversion rate of HIV-negative spouse and its associated risk factors among HIV sero-different couples in rural China. Methods: An open cohort of HIV sero-different couples enrolled in 30 counties in China between October 1, 2010, and September 30, 2012, and followed-up to December 31, 2012, was constructed retrospectively. A nested case-control study of risk factors of HIV seroconversion among sero-different couples was conducted in April and May of 2013, based on the open cohort. Sero-different couples with the HIV-negative spouse seroconverting at least 3 months after the previous negative diagnosis during cohort observation period were labeled as “case couples”. The “control couples” were selected randomly from the same cohort that did not have the HIV-negative spouse seroconversion during the same period. The “case couples” and “control couples” were matched on gender, age, and region of residence. Sexual behaviors among HIV sero-different couples before and after the index spouses notifying their HIV infection status to their HIV-negative spouses were collected via face-to-face interview. Univariate and multivariate logistic regression models were used to assess factors associated with HIV seroconversion among HIV sero-different couples. Results: Of 4481 HIV sero-different couples, a total of 53 seroconversions were observed within 5218 person-years of follow-up. The incidence rate was 1.02 (95%CI: 0.76–1.33) per 100 person-years. Forty “case couples” confirmed HIV-negative spouse seroconversions infected via marital sexual transmission, were matched to 80 “control couples”. Of the 120 couples, 81(67.5%) were receiving ART, and 70 (58.3%) reported consistently used condoms during intercourse after the index spouse was diagnosed HIV infection. Multivariate conditional logistic regression analysis showed that the desire to conceive a child (OR = 5.18, 95% CI: 1.19–22.58) significantly increased the odds of HIV seroconversion. Protective factors of spousal HIV seroconversion were currently receiving ART (OR = 0.09, 95% CI: 0.01–0.67) and consistent condom use (OR = 0.05, 95% CI: 0.01–0.28). Conclusions: Intention to conceive a child is the most important risk factor for HIV seroconversion among sero-different couples. Specific efforts on scientific use of ART to assist sero-different couples to achieve their wish to conceive a healthy child are needed to minimize the risk of HIV transmission. [ABSTRACT FROM AUTHOR]

In 2013, the first case of human infection with an avian influenza A virus (H7N9) was reported in China, and the human infection with this virus has continued as of 2016. At the request of the WHO, we have successfully developed candidate reassortant vaccine virus using A/Anhui/1/2013 and the high egg-growth master virus A/PR/8/1934. Recent plans regarding influenza vaccine production include using cell-cultured systems in Japan and several other countries. However, egg-based vaccine viruses are not always suitable for cell-cultured vaccine production due to potential issues with growth, protein yield and antigenic stability. Therefore, in this study, we have developed a high-growth master virus (hg-PR8) adapted to qualified NIID-MDCK cells that are competent for vaccine production. The virus hg-PR8 was obtained after 20 serial passages of A/Puerto Rico/8/1934 (PR8) in NIID-MDCK cells. The viral titer of hg-PR8 was 108.6 plaque-forming units per milliliter (PFU/mL). Seven amino acid substitutions were identified in the amino acid sequences of PB2, PB1, PA, NA, M and NS of hg-PR8 compared to the sequence of the original PR8 (org-PR8) strain. The growth capacities of the reassortant viruses, which possess heterologous internal genes from hg-PR8 or org-PR8, indicated that the amino acid changes in PB2 and NS2 similarly affected growth capacity in NIID-MDCK cells. To assess the suitability of hg-PR8 as a master virus, we generated 6:2 reassortant viruses possessing the HA and NA segments from A/Anhui/1/2013 (H7N9) and the remaining segments from hg-PR8. The virus titers of the reassortant strains were 107−108 PFU/mL. The antigenicity of the viruses was stable during ten passages of the viruses in NIID-MDCK cells. In comparison with the egg-based reassortant vaccine viruses with identical HA and NA segments, the hg-PR8-based viruses showed 1.5- to 2-fold higher protein yields in NIID-MDCK cells. [ABSTRACT FROM AUTHOR]

The grass carp (Ctenopharyngodon idella) is an important commercial farmed herbivorous fish species in China, but is susceptible to Aeromonas hydrophila infections. In the present study, we performed de novo RNA-Seq sequencing of spleen tissue from specimens of a disease-resistant family, which were given intra-peritoneal injections containing PBS with or without a dose of A. hydrophila. The fish were sampled from the control group at 0 h, and from the experimental group at 4, 8, 12, 24, 48 and 72 h. 122.18 million clean reads were obtained from the normalized cDNA libraries; these were assembled into 425,260 contigs and then 191,795 transcripts. Of those, 52,668 transcripts were annotated with the NCBI Nr database, and 41,347 of the annotated transcripts were assigned into 90 functional groups. 20,569 unigenes were classified into six main categories, including 38 secondary KEGG pathways. 2,992 unigenes were used in the analysis of differentially expressed genes (DEGs). 89 of the putative DEGs were related to the immune system and 41 of them were involved in the complement and coagulation cascades pathway. This study provides insights into the complement and complement-related pathways involved in innate immunity, through expression profile analysis of the genomic resources in C. idella. We conclude that complement and complement-related genes play important roles during defense against A. hydrophila infection. The immune response is activated at 4 h after the bacterial injections, indicating that the complement pathways are activated at the early stage of bacterial infection. The study has improved our understanding of the immune response mechanisms in C. idella to bacterial pathogens. [ABSTRACT FROM AUTHOR]

The Panton-Valentine leukocidin (PVL) genes of methicillin-resistant Staphylococcus aureus (MRSA) have previously been associated with severe infections. Here, the impact of the PVL genes on severity of disease and clinical outcome of patients with hospital-acquired pneumonia (HAP) or ventilator-associated pneumonia (VAP) due to MRSA was investigated in a single center observational study in a hospital in China. HAP due to MRSA was diagnosed in 100 patients and 13 of the patients were PVL positive, while VAP was diagnosed in 5 patients and 2 were PVL positive. The PVL positive patient group showed a significantly higher Acute Physiology and Chronic Health Evaluation (APACHE) II score (14.3 ±7.8 vs. 10.1 ±4.7, P = 0.005) and significantly more patients with CRP levels >80 mg/L (8/15 vs. 12/90, P = 0.006) or WBC counts >15x109/L (7/15 vs. 12/90, P = 0.006), indicating that the severity of disease is affected by the presence of the PVL genes. The outcome of the study was defined by 30-day mortality. Four (27%) of the PVL positive patients and four (4%) of the PVL negative patients died within 30 days (P = 0.01, Fisher exact test). Kaplan-Meier survival curves were generated for the PVL positive and PVL negative patient groups, which differed significantly (P = 0.003). Among the patients that died, the mean interval between diagnosis and death was shorter for the PVL positive patients (9.3 ±5.6 vs. 40.8 ±6.6 days, P = 0.013). Further analysis within the HAP and VAP patient groups showed that the presence of PVL in MRSA impacted the severity of disease and clinical outcome of HAP, but for VAP the number of patients included in the study was too low. In conclusion, in this single center study in a Chinese hospital the presence of the PVL genes in MRSA impacted the severity of disease and clinical outcome in patients with HAP due to MRSA. [ABSTRACT FROM AUTHOR]

The objectives of this study were to estimate the herd prevalence of major mastitis pathogens in bulk tank milk (BTM) in China dairy herds, to determine the relationship between the presence of mastitis pathogens and bulk tank milk somatic cell counts (BTSCC), and to investigate the impact of different dairy cattle farming modes and region on bacterial species. BTM samples collected from 894 dairy herds in China were examined for the presence of mastitis pathogens. The Flinders Technology Associates (FTA) cards were used for BTM sample collection, storage, and transportation and bacterial DNA amplification by real-time PCR. Among contagious pathogens, Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae were detected in 50.1, 92.2, and 72.3% of the 894 BTM samples, respectively. Among environmental pathogens, E. coli, Streptococcus uberis, Enterococcus spp., Klebsiella spp., Serratia marcescens, Corynebacterium bovis, and Arcanobacterium pyogenes were detected in 28.6, 8.9, 35.7, 20.0, 1.3, 17.0, and 67.2% of the BTM samples, respectively. Staphylococcal β-lactamase gene was detected in 61.7% of the BTM samples. The presence of Staphylococcus aureus and Arcanobacterium pyogenes were significantly associated with high BTSCC, respectively. Significant differences were found in presence of Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae in BTM sampled from the small household farms, dairy-farming communities, and large-scaled dairy farms. There were significant differences in the presence of Streptococcus agalactiae, Streptococcus dysgalactiae, Arcanobacterium pyogenes, staphylococcal β-lactamase gene, Staphylococcus spp., Klebsiella spp., Enterococcus spp., and Streptococcus uberis in BTM among Inner Mongolia, Heilongjiang, and Hebei province. In conclusion, contagious mammary pathogens are predominated among pathogens in BTM samples in China. [ABSTRACT FROM AUTHOR]

In China, B. burgdorferi, B.garinii, B. afzelii and B. yangtze sp. nov have been reported; B.garinii and B. afzelii are the main pathogenic genotypes. But until now only one Chinese strain was reported with whole genome sequence. In order to further understand the genomic characteristics and diversity of Chinese Borrelia strains, 5 isolates from China were sequenced and compared with the whole genome sequences of strains in other areas. The results showed a high degree of conservation within the linear chromosome of Chinese strains, whereas plasmid showed a much larger diversity according to the majority genomic information of plasmids. The genome sequences of the five Chinese strains were compared with the corresponding reference strains, respectively, according to the genospecies. Pairwise analysis demonstrates that there are only 70 SNPs between the genomes of CS4 and B31. However, there are many more SNPs between the genomes of QX-S13 and VS116, PD91 and PBi, FP1 and PKo, R9 and Pko, respectively. Gene comparison showed some important different genes. OspA was one of the important different genes. Comparative genomic studies have found that OspA gene sequences of PD91 and R9 had great differences compared with the sequence of B31. OspA gene sequence of R9 had a 96bp deletion; OspA gene of PD91 had two deletions: 9bp and 10 bp. To conclude, we showed the genomic characteristics of four genotype Chinese B. burgdorferi strains. The genomic sequence of B. yangtze sp. nov and differences from B. valaisiana were first reported. Comparative analysis of Chinese strains with the different Borrelia species from other areas will help us to understand evolution and pathogenesis of Chinese Borrelia burgdorferi strains. [ABSTRACT FROM AUTHOR]

Background: Our long-term field survey revealed that the Cardinium infection rate in Bemisia tabaci Q (also known as biotype Q) population was low in Shandong, China over the past few years. We hypothesize that (1) the Cardinium-infected (C+) B. tabaci Q population cannot efficiently compete with the Cardinium-uninfected (C−) B. tabaci Q population; (2) no reproductive isolation may have occurred between C+ and C−; and (3) the C− population has higher fitness than the C+ population. Methodology and Results: To reveal the differences in competitive ability and fitness between the two introduced populations (C+ and C−), competition between C+ and C− was examined over several generations. Subsequently, the reproductive isolation between C+ and C− was studied by crossing C+ with C− individuals, and the fitnesses of C+ and C− populations were compared using a two-sex life table method. Our results demonstrate that the competitive ability of the C+ whiteflies was weaker than that of C−. There is that no reproductive isolation occurred between the two populations and the C− population had higher fitness than the C+ population. Conclusion: The competitive ability and fitness differences of two populations may explain why C− whitefly populations have been dominant during the past few years in Shandong, China. However, the potential role Cardinium plays in whitefly should be further explored. [ABSTRACT FROM AUTHOR]