Variable-number tandem repeats as molecular markers for biotypes of Pasteuria ramosa in Daphnia spp

Variable-number tandem repeats (VNTRs) have been identified in populations of Pasteuria ramosa, a castrating endobacterium of Daphnia species. The allelic polymorphisms at 14 loci in laboratory and geographically diverse soil samples showed that VNTRs may serve as biomarkers for the genetic characterization of P. ramosa isolates.     

Variable-Number Tandem Repeats as Molecular Markers for Biotypes of Pasteuria ramosa in Daphnia spp.

Variable-number tandem repeats (VNTRs) have been identified in populations of Pasteuria ramosa, a castrating endobacterium of Daphnia species. The allelic polymorphisms at 14 loci in laboratory and geographically diverse soil samples showed that VNTRs may serve as biomarkers for the genetic characterization of P. ramosa isolates.     

Hypoxia enhances buffalo adipose-derived mesenchymal stem cells proliferation,stemness, and reprogramming into induced pluripotent stem cells

Adipose tissue-derived mesenchymal stem cells (ASCs) from livestock are valuable resources for animal reproduction and veterinary therapeutics. Previous studies have shown that hypoxic conditions were beneficial in maintaining the physiological activities of ASCs. However, the effects of hypoxia on buffalo ASCs (bASCs) remain unclear. In this study, the effects of hypoxia on proliferation, stemness, and reprogramming into induced pluripotent stem cells (iPSCs) of bASCs were examined. The results showed that the hypoxic culture conditions (5% oxygen) enhanced the proliferation and colony formation of bASCs. The expression levels of proliferation-related genes, and secretion of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) were significantly enhanced in hypoxia. Hypoxic culture conditions activated hypoxia-inducible factor-1α (HIF-1α), thereby contributing to the secretion of bFGF and VEGF, which in turn enhanced the expression of HIF-1α and promoted the proliferation of bASCs. Furthermore, in hypoxic culture conditions, bASCs exhibited the main characteristics of mesenchymal stem cells, and the expression levels of the pluripotent markers OCT4, NANOG, C-MYC, and the differentiation capacity of bASCs were significantly enhanced. Finally, bASCs were more efficiently and easily reprogrammed into iPSCs in hypoxic culture conditions and these iPSCs exhibited some characteristics of naïve pluripotent stem cells. These findings provide the theoretical guidance for elucidating the detailed mechanism of hypoxia on physiological activities of bASCs including proliferation, stemness maintenance, and reprogramming.     

Antifungal Susceptibility Profile of Candida Albicans Isolated from Vulvovaginal Candidiasis in Xinjiang Province of China

We investigated the antifungal susceptibility profiles of 207 independent Candida albicans strains isolated from patients with vulvovaginal candidiasis (VVC) in Xinjiang Province of China. Using CLSI M27-A3 and M27-S4 guidelines, anidulafungin and micafungin were the most active drugs against C. albicans showing an MIC₅₀/MIC₉₀ corresponding to 0.016/0.0313 µg/mL, followed by caspofungin (0.25/0.25 µg/mL), posaconazole (0.125/0.5 µg/mL), ravuconazole (0.063/1 µg/mL), itraconazole (0.125/1 µg/mL), amphotericine B (0.5/1 µg/mL), isavuconazole (0.063/2 µg/mL), 5-flucytosine (1/2 µg/mL), voriconazole (0.125/4 µg/mL), and fluconazole (0.5/4 µg/mL). 96.1% (199)–100.0% (207) isolates were sensitive to the three echinocandins tested, amphotericine B and 5-flucytosine. The in vitro activity of triazoles against all isolates tested was variable; itraconazole and voriconazole had reduced the activity to almost half of the isolates (55.1% (114) and 51.2% (106) susceptible, respectively). Fluconazole was active against 76.3% (158) isolates tested. The new triazoles ravuconazole, isavuconazole and posaconazole showed good in vitro potency against 89.9% (186)–95.2% (197) of isolates with the geometric mean MIC (µg/mL) of 0.10, 0.12 and 0.14 µg/mL, respectively. In conclusion, our study indicates that for effective management of systemic candidiasis in Xinjiang Province of China, it is important to determine the susceptibility profiles of isolated C. albicans from patients with VVC.

     

289株VVC致病菌的菌种分布和对9种抗真菌药物敏感性

外阴阴道念珠菌病（vulvovaginal candidiasis,VVC）是女性的常见病。本研究收集了2018年1月-12月苏州地区VVC患者分离的289株念珠菌进行了病原学鉴定和包括棘白菌素类、新三唑类药物在内的9种抗真菌药物体外敏感性分析。本文采用核糖体RNA的D1/D2基因进行念珠菌菌种鉴定。参照M27-A3方法检测其对9种抗真菌药物（包括棘白菌素类及新三唑类药物）的体外敏感性。结果表明,289株VVC念珠菌菌株中,白念珠菌259株、光滑念珠菌14株、克柔念珠菌10株、热带念珠菌4株、近平滑念珠菌2株。259株VVC白念珠菌对棘白菌素类体外敏感性好,对米卡芬净敏感性高于另外两种棘白菌素类;对两性霉素B、5-氟胞嘧啶、氟康唑敏感性好;但对伊曲康唑、伏立康唑敏感性差;对泊沙康唑敏感性好。光滑念珠菌株和克柔念珠菌分离株对卡泊芬净敏感性差,但对米卡芬净、阿尼芬净敏感性好;光滑念珠菌株对两性霉素B、5-氟胞嘧啶体外敏感性好,对伊曲康唑敏感性差,对泊沙康唑敏感性好;伏立康唑对光滑念珠菌分离株MIC₅₀/₉₀为0.5/1μg/mL;克柔念珠菌对伊曲康唑、伏立康唑50%耐药;4株热带念珠菌对伊曲康唑50%耐药,对卡泊芬净、氟康唑、伏立康唑100%耐药,对其余5种抗真菌药物敏感。近平滑念珠菌对9种抗真菌药物均敏感。白念珠菌仍为苏州地区VVC的主要病原菌,其次是光滑念珠菌和克柔念珠菌,它们对临床常用药物伊曲康唑、伏立康唑、卡泊芬净敏感性差。研究结果提示对VVC病人常规进行分泌物培养、菌种鉴定,对苏州地区临床医生制定VVC治疗方案具有重要参考价值。尽管棘白菌素类、两性霉素B、5-氟胞嘧啶、新三唑类药物尚未应用到VVC的临床治疗中,但是这些药物对VVC病原体总体敏感性较好,未来有望成为氟康唑、咪唑类药物治疗失败患者的新选择。     

Aspidistra longgangensis sp. nov. (Asparagaceae) from limestone areas in Guangxi,China

Aspidistra longgangensis C. R. Lin, Y. S. Huang & Yan Liu, a new species of Asparagaceae from the limestone areas in Guangxi, China, is described and illustrated. It is similar to A. guangxiensis S. C. Tang & Yan Liu in the shape of the flower, but differs by leaf blade pachyphyllous and bigger; the perianth lobes with appendages at base, appendage oblong, 3–5 mm long, apex incurved; stigma upper surface white, with 4(3) radial, bifurcate lines in the center. The new species is currently known only from Longgang National Natural Reserve, situated in southwestern Guangxi, China, near the border with northern Vietnam.     

Acaricidal properties of an Ailanthus altissima bark extract against Psoroptes cuniculi and Sarcoptes scabiei var. cuniculi in vitro

The potential acaricidal properties of an Ailanthus altissima bark extract were assessed against two common species of animal ectoparasitic mites, Psoroptes cuniculi and Sarcoptes scabiei var. cuniculi, in vitro. A. altissima bark extract was obtained by ethanol thermal circumfluence and tested at four concentrations (1.0, 0.5, 0.25 and 0.125 g/ml) on mites collected from rabbits. Compared to the fenvalerate treatment group, the A. altissima bark exhibited significant acaricidal properties for both mite species treated. The extract of concentrations of 1.0, 0.5 and 0.25 g/ml killed all tested S. scabiei within 7 h, however, only 1.0 and 0.5 g/ml of extract killed all treated P. cuniculi. The median lethal time (LT₅₀) values at 1, 0.5 and 0.25 g/ml were 0.60, 0.78, 1.48 h for S. scabiei and 0.74, 1.29, 3.33 h for P. cuniculi. The median lethal concentration (LC₅₀) for P. cuniculi was approximately 1.6 times that for S. scabiei var. cuniculi at 4 h. The extract showed stronger toxicity against S. scabiei than against P. cuniculi. Mortality rates increased with increasing concentration of extract administered and with increasing time post-treatment, indicating that the acaricidal activity of A. altissima bark extract is both time-dependent and dose-dependent. This is the first report on acaricidal activity of A. altissima against P. cuniculi and S. scabiei var. cuniculi. It indicates that A. altissima contain potential acaricidal compounds. Our study is the first step to develop potentially novel compounds from A. altissima for the effective control of mites in livestock.     

Comparative genomic analysis of clinical and environmental strains provides insight into the pathogenicity and evolution of Vibrio parahaemolyticus

Background

Vibrio parahaemolyticus is a Gram-negative halophilic bacterium. Infections with the bacterium could become systemic and can be life-threatening to immunocompromised individuals. Genome sequences of a few clinical isolates of V. parahaemolyticus are currently available, but the genome dynamics across the species and virulence potential of environmental strains on a genome-scale have not been described before.

Results

Here we present genome sequences of four V. parahaemolyticus clinical strains from stool samples of patients and five environmental strains in Hong Kong. Phylogenomics analysis based on single nucleotide polymorphisms revealed a clear distinction between the clinical and environmental isolates. A new gene cluster belonging to the biofilm associated proteins of V. parahaemolyticus was found in clincial strains. In addition, a novel small genomic island frequently found among clinical isolates was reported. A few environmental strains were found harboring virulence genes and prophage elements, indicating their virulence potential. A unique biphenyl degradation pathway was also reported. A database for V. parahaemolyticus (http://kwanlab.bio.cuhk.edu.hk/vp) was constructed here as a platform to access and analyze genome sequences and annotations of the bacterium.

Conclusions

We have performed a comparative genomics analysis of clinical and environmental strains of V. parahaemolyticus. Our analyses could facilitate understanding of the phylogenetic diversity and niche adaptation of this bacterium.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-1135) contains supplementary material, which is available to authorized users.     

A Systematic Review of Scope and Quality of Health Economic Evaluation Studies in Vietnam

Introduction

The application of health economic evaluation (HEE) evidence can play an important role in strategic planning and policy making. This study aimed to assess the scope and quality of existing research, with the goal of elucidating implications for improving the use of HEE evidence in Vietnam.

Methods

A comprehensive search strategy was developed to search medical online databases (Medline, Google Scholar, and Vietnam Medical Databases) to select all types of HEE studies except cost-only analyses. Two researchers assessed the quality of selected studies using the Quality of Health Economic Studies (QHES) instrument.

Results

We selected 26 studies, including 6 published in Vietnam. The majority of these studies focused on infectious diseases (14 studies), with HIV being the most common topic (5 studies). Most papers were cost-effectiveness studies that measured health outcomes using DALY units. Using QHES, we found that the overall quality of HEE studies published internationally was much higher (mean score 88.7+13.3) than that of those published in Vietnam (mean score 67.3+22.9). Lack of costing perspectives, reliable data sources and sensitivity analysis were the main shortcomings of the reviewed studies.

Conclusion

This review indicates that HEE studies published in Vietnam are limited in scope and number, as well as by several important technical errors or omissions. It is necessary to formalize the process of health economic research in Vietnam and to institutionalize the links between researchers and policy-makers. Additionally, the quality of HEE should be enhanced through education about research techniques, and the implementation of standard HEE guidelines.