海南地区类鼻疽伯克霍尔德菌PFGE分子分型及同源性分析

目的通过对海南地区类鼻疽伯克霍尔德菌分离株进行脉冲场电泳(PFGE)分子分型分析,探讨海南地区类鼻疽伯克霍尔德菌之间的同源性,了解海南地区类鼻疽流行和分布特征。方法对海南地区2006年7月~2013年4月临床分离的97株类鼻疽伯克霍尔德菌采用PFGE方法进行分子分型,用BioNumerics软件进行聚类分析和同源性比较。结果 97株类鼻疽伯克霍尔德菌分布于海南省18个市县中的14个市县,其中东方市所占比例最高,为17.5%;沿海地区占90.7%(88/97)。感染类型以败血症为主,占61.9%。分离菌的PFGE带型呈现多态性,相似性系数为67.8%。在85%相似度水平以上时,实验菌株分为20个PFGE基因型,其中PFGE12型所占比例最高,占29.8%(29/97),且在本型中有7株菌PFGE条带100%相似,占本型菌的24.1%(7/29)。分离菌中所占比例位于第二和第三的分别是PFGE-9(占18.5%)和PFGE-16型(占14.4%)。结论 PFGE分子分型可较好地对菌株进行同源性分析。海南地区流行的类鼻疽伯克霍尔德菌PFGE型别呈多态性,但存在一些克隆群优势流行。     

我国食品来源金黄色葡萄球菌种群结构分析

目的了解我国食源性金黄色葡萄球菌(金葡菌)的种群结构。方法通过全基因组测序方法对2006-2020年我国16个省份收集的763株食源性金葡菌进行多位点序列分型、葡萄球菌蛋白A编码基因(spa)和葡萄球菌染色体mec基因盒(SCCmec)分型, 使用BioNumerics 7.5软件创建基于ST类型的最小生成树。国外进口食品分离到的金葡菌31株被纳入基因组系统发育树的构建。结果 763株金葡菌共鉴定出90个ST型和160个spa型别, 其中20种为新ST型别。72个(72/90, 80.0%)ST型属于22个克隆群, 其中主要型别为CC7、CC1、CC5、CC398、CC188、CC59、CC6、CC88、CC15和CC25, 占82.44%(629/763)。其中优势克隆群中ST型和spa型别随着时间的变化呈多态性变化。耐甲氧西林金葡菌(MRSA)的阳性率为7.60%, 共鉴定出7种SCCmec型别, 以ST59-t437-Ⅳa(17.24%, 10/58)、ST239-t030-Ⅲ(12.07%, 7/58)、ST59-t437-Ⅴb(8.62%, 5/58)、ST338-t437-...     

世界卫生组织真菌重点病原清单的启示

世界卫生组织于2022年10月制定了首份真菌重点病原清单,旨在加强全球对真菌感染和抗真菌药物耐药性的响应,关注并推动进一步的研究和政策干预。该真菌重点病原清单及其制定过程对于我国病原真菌及侵袭性真菌病（IFD）工作具有新的重要的启示作用：应加强我国IFD的公共卫生干预措施;进一步提高我国IFD及病原真菌的实验室检测与临床监管能力;有针对性地增加投资与支持以用于IFD诊疗和防控的创新性研发。     

A bivalent outer membrane vesicle-based intranasal vaccine to prevent infection of periodontopathic bacteria

Periodontal disease has become a serious public health problem, not only causing tooth loss, but also inducing chronic disorders of extra-oral organs. The present study assessed an intranasal vaccine strategy to prevent periodontal disease using outer membrane vesicles (OMVs) of two major periodontopathic bacteria, Porphyromonas gingivalis (Pg) and Aggregatibacter actinomycetemcomitans (Aa). We compared the morphology, composition, and immune activity between OMVs of Pg strain ATCC 33277 and Aa strain Y4. Aa OMVs had a smoother surface and stronger lipid A activity compared to Pg OMVs. The in vitro immune activity elicited by Aa OMVs in macrophage-like cells was remarkably stronger than that of Pg OMVs. Intranasal immunization of mice with Aa OMVs alone resulted in robust, humoral immune responses in blood and saliva. Despites the intrinsically low mucosal immunogenicity of Pg OMVs alone, using Aa OMVs as a mucosal adjuvant strongly enhanced Pg-specific immune responses, resulting in both serum IgG and salivary IgA, both of which aggregated Pg and Aa cells. Furthermore, Aa OMVs were found to be a more potent mucosal adjuvant than Poly(I:C) in the context of enhancing the production of Pg-specific IgG (especially IgG2a) and IgA. In addition, in a randomized, blinded study, mice oral challenged with Pg and Aa after intranasal immunization with Pg OMVs and Aa OMVs had significantly decreased numbers of both microorganisms compared to mock-immunized mice. Furthermore, in an intracerebral injection mouse model, there were no serious adverse effects on the brain even after administrating a dose of OMVs as same as that used for intranasal administration. Taken together, the bivalent OMV intranasal vaccine may be effective in preventing colonization of periodontopathic bacteria in the oral cavity and related systemic disorders associated with periodontal diseases.     

Genetic Diversity,Antibiotic Resistance,and Pathogenicity of Aeromonas Species from Food Products in Shanghai,China

ObjectiveAeromonas has recently been recognized as an emerging human pathogen. Aeromonas-associated diarrhea is a phenomenon occurring worldwide. This study was designed to determine the prevalence, genetic diversity, antibiotic resistance, and pathogenicity of Aeromonas strains isolated from food products in Shanghai.MethodsAeromonas isolates (n = 79) collected from food samples were analyzed using concatenated gyrB-cpn60 sequencing. The antibiotic resistance of these isolates was determined using antimicrobial susceptibility testing. Pathogenicity was assessed using β-hemolytic, extracellular protease, virulence gene detection, C. elegans liquid toxicity (LT), and cytotoxicity assays.ResultsEight different species were identified among the 79 isolates. The most prevalent Aeromonas species were A. veronii [62 (78.5%)], A. caviae [6 (7.6%)], A. dhakensis [3 (3.8%)], and A. salmonicida [3 (3.8%)]. The Aeromonas isolates were divided into 73 sequence types (STs), of which 65 were novel. The isolates were hemolytic (45.6%) and protease-positive (81.0%). The most prevalent virulence genes were act (73.4%), fla (69.6%), aexT (36.7%), and ascV (30.4%). The results of C. elegans LT and cytotoxicity assays revealed that A. dhakensis and A. hydrophila were more virulent than A. veronii, A. caviae, and A. bivalvium. Antibiotic resistance genes [tetE, blaTEM, tetA, qnrS, aac(6)-Ib, mcr-1, and mcr-3] were detected in the isolates. The multidrug-resistance rate of the Aeromonas isolates was 11.4%, and 93.7% of the Aeromonas isolates were resistant to cefazolin.ConclusionThe taxonomy, antibiotic resistance, and pathogenicity of different Aeromonas species varied. The Aeromonas isolates A. dhakensis and A. hydrophila were highly pathogenic, indicating that food-derived Aeromonas isolates are potential risks for public health and food safety. The monitoring of food quality and safety will result in better prevention and treatment strategies to control diarrhea illnesses in China.     

Gene Knockdown in Human Rhinovirus 1B Using 2′-OMe-modified si RNAs Results in the Reactivation of the Interferon Response

正The aim of this study was to investigate the knockdown efficiency of 2’-O-methylated(2’-OMe)-modified small interfering RNAs(siR NAs)on human rhinovirus 1B(HRV1B)replication and the interferon response.Thus,24 2’-OMe-modified siR NAs were designed to target HRV1B.The RNA levels of HRV1B,Toll-like receptor 3,melanoma differentiation-associated gene 5,retinoic acid     

Rotavirus diarrhoea hospitalizations among children under 5 years of age in Nigeria, 2011–2016

BackgroundThe high burden of rotavirus acute gastroenteritis (AGE) is well documented among children under 5 years of age, with the majority of mortality occurring in developing countries. Nigeria ranked second worldwide in the number of rotavirus deaths in 2013. As Nigeria plans to introduce rotavirus vaccine soon, a pre-vaccine documentation of rotavirus disease burden is necessary to determine vaccine impact.MethodsRoutine rotavirus surveillance was conducted during 2011–2016 in 3 sentinel sites in Nigeria using the standard WHO protocol. Children under 5 years of age hospitalized for acute gastroenteritis were enrolled and demographic, clinical and outcome data were collected. A stool sample was subsequently obtained and tested for human rotavirus antigen using the Enzyme-linked immunosorbent assay (ELISA).Results2694 children with acute gastroenteritis were enrolled during January 2011 to December 2016; of these, 1242 (46%) tested positive for rotavirus. Among the rotavirus positive cases, 66% and 94% were younger than 12 months and 24 months respectively. Marked peaks in rotavirus positivity were seen in January of each year. Vomiting, and use of oral and intravenous fluids occurred more often in rotavirus positive cases as compared to rotavirus negative cases.ConclusionThe high prevalence of rotavirus disease highlights the need for urgent introduction of rotavirus vaccine in Nigeria. Additionally, this study provides pre-vaccine introduction disease-burden data that will serve as a baseline for rotavirus vaccine impact-assessment once vaccine has been introduced in the national immunization program.