潜在致病性的弗氏枸橼酸杆菌的筛查

目的 筛查具有潜在致病性的弗氏枸橼酸杆菌。方法 对从河南省睢县分离到的36株弗氏枸橼酸杆菌进行黏附HEp-2细胞的检测,以及与HEp-2细胞(MOI: 100)作用10 h后的乳酸脱氢酶(LDH)释放情况分析。同时比较弗氏枸橼酸杆菌CF74(Citrobacter freundii 74)、CF72(Citrobacter freundii 72)、肠聚集性大肠埃希菌(Enteroaggregative E. coli,EAEC)、肠致病性大肠埃希菌(Enteropathogenic E. coli,EPEC)2348/69和HB101的黏附和细胞毒性差异。结果 16株弗氏枸橼酸杆菌几乎没有黏附性,黏附指数1;18株弗氏枸橼酸杆菌具有中等强度的黏附性,黏附指数100;2株弗氏枸橼酸杆菌CF74和CF65(Citrobacter freundii 65)具有强的黏附性。与HEp-2细胞作用10 h后,除了CF74(24.4%),其余的35株弗氏枸橼酸杆菌具有低的LDH释放量,LDH释放量与阴性对照HB101(5.02%)相似。说明除了CF74,其余的弗氏枸橼酸杆菌不具有细胞毒性。CF74具有和EAEC042一样的聚集性黏附类型,并且 CF74引起的LDH释放率明显高于CF72、2348/69和HB101(P0.01)而低于EAEC17-2。结论 作为潜在的致病菌,CF74具有强的黏附性和细胞毒性。     

一种鉴别与大肠埃希菌O157血清凝集的弗氏枸橼酸杆菌的PCR方法

目的利用基于O抗原翻转酶wzx基因的PCR方法,鉴别与大肠埃希菌O157血清凝集的弗氏枸橼酸杆菌和O157大肠埃希菌。方法用微生物鉴定仪对细菌进行生化鉴定,与O157血清凝集,同时扩增wzx基因。结果25株与大肠埃希菌O157血清凝集的弗氏枸橼酸杆菌及1株不与大肠埃希菌O157血清凝集的弗氏枸橼酸杆菌wzx基因扩增为阳性,8株与O157血清不凝集的弗氏枸橼酸杆菌wzx基因扩增为阴性,20株O157∶H7大肠埃希菌wzx基因扩增为阴性。结论对于可与O157血清发生强凝集的弗氏枸橼酸杆菌,基于O抗原翻转酶wzx基因的PCR方法是一种有效的快速鉴别方法。     

斯氏弓形杆菌基于基因组序列遗传特征分析

  目的  获得斯氏弓形杆菌的遗传特征,并对其耐药基因及毒力相关基因进行预测分析。  方法  对本实验室分离培养的8株斯氏弓形杆菌进行基因组测序并从NCBI和PATRIC数据库中下载全部已完成基因组测序的15株斯氏弓形杆菌的全基因组序列,应用生物信息学软件对23株不同地域、不同宿主来源的斯氏弓形杆菌进行遗传特征分析。  结果  23株斯氏弓形杆菌中仅3株菌携带耐药基因,且均为β-内酰胺类抗生素耐药基因。 所有菌株均含有与免疫逃避、侵袭及运动等相关的毒力基因。 与其他菌种弓形杆菌常见的10种毒力基因比对分析发现,本研究中所有斯氏弓形杆菌菌株均含有ciaB、tlyA、cj1349、pldA和mviN基因,2株菌（CNAS12-1和F28）含有iroE基因,均不携带另外4种毒力基因。 21.7%（5/23）的菌株包含Ⅵ型分泌系统（T6SS）基因簇,且其与弯曲菌属内的T6SS存在基因组成及排列的差异。  结论  斯氏弓形杆菌有较高的遗传多样性,部分菌株可能有潜在的耐药和致病特征。     

应用全基因组表达谱芯片研究特比奈芬诱导白念珠菌耐药前后基因的差异性表达

目的应用白念珠菌全基因组表达谱芯片比较特比萘芬体外诱导白念珠菌产生耐药性前后基因表达谱的差异,以了解白念珠菌对特比萘芬产生耐药性的相关基因。方法白念珠菌ATCC90028菌株在浓度倍增的特比萘芬诱导下形成耐药的白念珠菌ATCC90028-R株,应用白念珠菌全基因组表达谱芯片比较白念珠菌ATCC90028和ATCC90028-R株全基因组表达谱的差异。结果基因芯片共筛选出109个差异表达基因,与白念珠菌ATCC90028株比较,在ATCC90028-R株中有46个基因表达上调,有63个基因表达下调。结论白念珠菌对特比萘芬耐药性的产生可能与其分子转运和解毒相关基因表达的上调,以及有关蛋白质合成、能量生成、糖转运蛋白、细胞应激反应、金属离子平衡基因表达的下调密切相关。     

266株腹泻病原菌的分布及耐药性分析

目的：了解我院急、慢性腹泻病人的菌群分布及耐药性特征，为临床用药提供依据。方法：应用回顾性调查分析的方法，对我院近4年腹泻病人大便中分离的266株病原菌进行统计并对常见细菌耐药率进行分析。结果：急性腹泻病人最常见的是福氏志贺菌，食物中毒引起的腹泻最常见的是沙门氏菌和弗氏枸橼杆菌，慢性腹泻病人最常见的是弗氏枸橼酸杆菌，其次是变形杆菌、亚利桑那菌和白色念珠菌。分离菌株中耐药性以氨苄西林、头孢唑啉的耐药率最高，达(33％～92％)，对亚胺培南、第四代头孢菌素较敏感，敏感率在90％以上。弗氏枸橼酸杆菌产AmpC酸占33％。结论：腹泻病人的病原菌都有不同程度的耐药性，进行常规的耐药性监测，根据药敏试验合理应用抗菌素十分重要。     

弗氏枸橼酸杆菌TaqMan实时荧光定量-聚合酶链反应检测方法的建立

目的 建立针对弗氏枸橼酸杆菌的TaqMan实时荧光定量-聚合酶链反应(real time-PCR)检测方法。 方法 针对弗氏枸橼酸杆菌的特有序列设计引物和TaqMan探针,扩增目的基因建立标准曲线,确定检测方法的灵敏度;对20种其他肠道致病菌及院内感染中常见的致病菌进行检测,评价该检测方法的特异性;使用牛奶模拟标本评价方法在实际检测工作中应用性。 结果 TaqMan real time-PCR检测方法对弗氏枸橼酸杆菌重组质粒的检测灵敏度为1.0101拷贝／反应体系;该检测方法在检测30种其他肠道致病菌及院内感染中常见的致病菌时未出现特异性扩增。该检测方法对牛奶模拟样本中弗氏枸橼酸杆菌检测下限为1.0102cfu/ml的菌量;通过对1.0107、1.0105和1.0103三个浓度质粒标准品的重复检测,确定本方法的组内变异系数为1.90%~3.91%;组间变异系数为1.52%~1.69%。 结论 本研究建立的TaqMan real time-PCR检测方法可作为检测弗氏枸橼酸杆菌灵敏、特异、快速的方法。     

安徽省马鞍山市分离的枸橼酸杆菌的分子分型

目的 了解中国安徽省马鞍山市分离到的枸橼酸杆菌的分子流行病学特征。方法 2007-2011年从安徽省马鞍山市的腹泻患者粪便、食品和食品加工者肛拭分离到62株枸橼酸杆菌,包括13株弗氏枸橼酸杆菌、41株杨氏枸橼酸杆菌和8株布氏枸橼酸杆菌。所有菌株用Xba Ⅰ酶切进行脉冲场凝胶电泳（PFGE）分型和扩增7个管家基因的多位点序列分型（MLST）分析。结果 PFGE将62株枸橼酸杆菌分成43个带型（PTs）,MLST将其分成53个ST型别（STs）。CITX01.CN0039是PFGE的优势带型,由2007-2008年间从食品和腹泻患者粪便分离的7株杨氏枸橼酸杆菌组成。53个ST型别分成5个ST序列群,ST序列群39个优势菌株来自腹泻患者粪便、食品和食品加工者肛拭分离的枸橼酸杆菌。从腹泻患者粪便、食品和食品加工者肛拭分离得到的枸橼酸杆菌具有相同的PTs和STs。结论 在食品和人群中监测枸橼酸杆菌对预防和控制枸橼酸杆菌引起的腹泻是必要的。     

1株LpsB突变致多黏菌素B耐药鲍曼不动杆菌的全基因测序分析*

摘要:目的研究1 株多黏菌素B高水平耐药的多重耐药鲍曼不动杆菌的全基因组测序的分子特点。方法将1株分离自脑脓肿患者脑脊液标本的多黏茵素高水平耐药鲍曼不动杆菌Z198株作为目标研究菌，通过Nanopore PromethION和llumina No- vaSeq PE150测序平台对其进行全基因组测序,再通过各数据库进行比对分析检测菌株的多位点序列分型(MLST)、抗菌药物耐药基因、毒力基因,同时采用Circos软件对样品基因组组装和注释结果进行可视化分析。Z198基因组上交NCBI数据库。结果全基因组测序发现该菌株含有1 个染色体、1个固有质粒,11个基因岛、4个前噬菌体。通过数据库比对,本菌为ST2型,共携带高达34种抗菌药物耐药基因,主要为IpsB、blaoxA.23、blaox.6、blaxDc-.-3等,同时含有OmpA、磷脂酶C、包膜、溶血素、 生物膜调控系统等19 种主要毒力因子。结论本研究检出 1例LpsB四点突变导致多黏菌素B耐药的鲍曼不动杆菌。该菌株同时携带多重耐药基因及毒力因子。多黏菌素耐药鲍曼不动杆菌外膜脂质修饰的耐药机制及分子流行病学需高度持续关注。     

弗氏枸橼酸杆菌引起的急性坏死性小肠炎1例报道

1999年11月30日我们从1例患有急性坏死性小肠炎的女患者腹腔引流液及术后回肠、回盲部溃疡面积的分泌物中分离出C.freundii(弗氏枸橼酸杆菌).该菌在血平板,SS,麦康凯及巧克力等平皿上均生长,菌落呈灰白色,中等大小,湿润,SS平皿上产H2S.革兰染色为革兰阴性菌,周身鞭毛,氧化酶(-),将其接种肠杆菌科生化编码鉴定管,结果尿素(-),苯丙氨酸(-),硫化氢(+),发酵葡萄糖产酸产气,乳糖(+),赖氨酸脱羧酶(-),鸟氨酸脱羧酶(+),运动性(+),靛基质(-),柠檬酸盐(+),VP(-),DNA酶(-),甲基红(+),丙二酸盐(+),棉子糖(+),L-鼠李糖(-),麦芽糖(+),纤维二糖(-),硝酸盐还原(+),酒石酸盐(+),参照<全国临床检验操作规程>中肠杆菌科的鉴别及生化编码,此菌为弗氏枸橼酸杆菌.因其分解乳糖,且沙门氏菌血清型鉴定为阴性,从而将此菌与沙门菌区分开.     

有氧运动对老年慢性阻塞性肺病患者骨骼肌全基因组表达的影响*

目的：研究有氧运动对慢性阻塞性肺病患者骨骼肌全基因组表达的影响及其促进健康的分子机制。方法：6例COPD患者参加了有计划的太极拳训练,在训练前和训练12周后,分别对实验对象的骨骼肌进行针吸活组织采样,经处理后采用基因芯片进行全基因组表达检测。结果：本研究将全基因组表达芯片技术、BRB基因分析软件及DAVID在线搜索的生物信息学手段相结合,对基因芯片生物信息进行初步探索。筛选出差异表达基因55条（其中10条表达下调,45条表达上调）。进行生物信息学分析后,发现有氧运动使核糖体蛋白基因（包括PRL28、PRS19、SNRPF、RPS21、SNRPE）表达下调,内毒素抑制蛋白（CRI1）基因表达上调,与COPD患者炎症细胞的抑制有关。结论：PIK3R1基因表达上调可能是导致TNF-α基因表达下调的分子机制。在众多调节机制和代谢途径中,各条基因的表达变化都与PIK3R1基因表达上调有关。     

Cellular immune response from Chagasic patients to CRA or FRA recombinant antigens of Trypanosoma cruzi

We propose to analyze the relation between the cellular immune response of Chagas' disease patients after in vitro stimulation of peripheral blood mononuclear cells (PBMC) with recombinant antigens cytoplasmatic repetitive antigen (CRA) or flagellar repetitive antigen (FRA) of T. cruzi and the chronic clinical forms of disease. Cells were stimulated using phytohemagglutinin, CRA, FRA, or a soluble antigen of Epimastigota (Ag-Epi) for 24 hr, 72 hr, or 6 days. The proliferation of cells was evaluated after 6 days of culture by quantification of incorporated 3H-thymidine. Cytokines were measured in the supernatants obtained after 24 hr (tumor necrosis factor [TNF]-alpha and interleukin [IL]-4), 72 hr (IL-10), and 6 days (interferon [IFN]-gamma) using enzyme-linked immunosorbent assay (ELISA). Cells of the Chagas patients stimulated with the recombinant antigens exhibited higher proliferation responses compared with that of non-Chagas (NC) individuals. However, when proliferation was compared between patients with the cardiac form (CF) or indeterminate form (IF), it was not possible to establish a difference in the response. So far as the cytokines secreted in the culture supernatants after stimulation in vitro with T. cruzi antigens were concerned, the results showed that CRA, as well as Epi-Ag, were able to stimulate the production of TNF-alpha and IFN-gamma in Chagas patients as compared with NC individuals. However, the cytokine levels after stimulation with the T. cruzi antigens were not different between the patients with CF and IF. CRA was capable of inducing a T helper type 1 (Th1) immune response, with elevated production of TNF-alpha and IFN-gamma in Chagas patients that are carriers of CF and IF clinical forms.     

Azithromycin inhibits the formation of flagellar filaments without suppressing flagellin synthesis in Salmonella enterica serovar typhimurium

The present study shows that a sub-MIC of the macrolide antibiotic azithromycin (AZM) diminishes the virulence function of Salmonella enterica serovar Typhimurium. We first constructed an AZM-resistant strain (MS248) by introducing ermBC, an erythromycin ribosome methylase gene, into serovar Typhimurium. The MIC of AZM for MS248 exceeded 100 microg/ml. Second, we managed to determine the efficacy with which a sub-MIC of AZM reduced the virulence of MS248 in vitro. On the one hand, AZM (10 microg/ml) in the culture medium was unable to inhibit the total protein synthesis, growth rate, or survival within macrophages of MS248. On the other hand, AZM (10 microg/ml) reduced MS248's swarming and swimming motilities in addition to its invasive activity in Henle-407 cells. Electron micrographs revealed no flagellar filaments on the surface of MS248 after overnight growth in L broth supplemented with AZM (10 microg/ml). However, immunoblotting analysis showed that flagellin (FliC) was fully synthesized within the bacterial cells in the presence of AZM (10 microg/ml). In contrast, the same concentration of AZM reduced the export of FliC to the culture medium. These results indicate that a sub-MIC of AZM was able to affect the formation of flagellar filaments, specifically by reducing the amount of flagellin exported from bacterial cells, but it was not involved in suppressing the synthesis of flagellin. Unfortunately, AZM treatment was ineffective against murine salmonellosis caused by MS248.     

Cellular response of human cardiac fibroblasts to mechanically simulated aortic regurgitation

Myocardial fibrosis has been identified in biopsy specimens from catheterization and valve replacement surgery in patients with severe chronic aortic regurgitation (AR). While characterization of these extracellular matrix (ECM) alterations has been incomplete in humans, fibrosis also has been identified in chronic severe experimentally created AR, in which ECM composition features abnormal fibronectin/glycoprotein production, with normal collagen content. Virtually identical ECM variations have been induced when normal rabbit cardiac fibroblasts (CF) are subjected in culture to cyclic mechanical strain mimicking that found in the left ventricle (LV) in severe AR. To determine whether the changes seen experimentally can be extrapolated to humans, we exposed normal human CF in culture to the mechanical strain employed in the experimental model to simulate severe AR (n=3 replications from 1 patient). CF were isolated from epicardial biopsy distant from diseased coronary arteries in a 38-year-old man with normal LV function and without prior myocardial infarction who was undergoing elective coronary artery bypass grafting. Gelatin Sepharose affinity chromatography (GSAC) and Western analysis were used to compare fibronectin expression in strained versus nonstrained normal human CF in tissue culture; Western analysis was used to compare type I collagen production. In AR-strained CF, fibronectin synthesis nominally increased [av 38% (Western) and 45% (GSAC)] relative to control; type I collagen synthesis was virtually unchanged. These results simulate those found experimentally and suggest that human CF, like rabbit CF, manifest abnormal compositional distribution of ECM proteins in AR.     

Impairment of swimming motility by antidiarrheic Lactobacillus acidophilus strain LB retards internalization of Salmonella enterica serovar Typhimurium within human enterocyte-like cells

We report that both culture and the cell-free culture supernatant (CFCS) of Lactobacillus acidophilus strain LB (Lactéol Boucard) have the ability (i) to delay the appearance of Salmonella enterica serovar Typhimurium strain SL1344-induced mobilization of F-actin and, subsequently, (ii) to retard cell entry by S. Typhimurium SL1344. Time-lapse imaging and Western immunoblotting showed that S. Typhimurium SL1344 swimming motility, as represented by cell tracks of various types, was rapidly but temporarily blocked without affecting the expression of FliC flagellar propeller protein. We show that the product(s) secreted by L. acidophilus LB that supports the inhibitory activity is heat stable and of low molecular weight. The product(s) caused rapid depolarization of the S. Typhimurium SL1344 cytoplasmic membrane without affecting bacterial viability. We identified inhibition of swimming motility as a newly discovered mechanism by which the secreted product(s) of L. acidophilus strain LB retards the internalization of the diarrhea-associated pathogen S. enterica serovar Typhimurium within cultured human enterocyte-like cells.     

Etidronate inhibits human osteoblast apoptosis by inhibition of pro-apoptotic factor(s) produced by activated T cells

Humoral factors produced by activated T cells are thought to be important in the development of bone loss in patients with rheumatoid arthritis (RA). We investigated the inhibitory effect of etidronate disodium (EHDP) on apoptosis of human osteoblasts induced by supernatants from in vitro activated T cell cultures. Human osteoblastic cell line MG63 cells and human primary osteoblast-like cells were used in the present study as human osteoblasts. T cells were incubated with interleukin-2 and further activated with 1 2-o-tetradecanoyl-phorbol 13-acetate and ionomycin, either in the presence or absence of EHDP. After we carried out the cultivation, we examined the cytotoxicity of cultured T cell supernatants toward MG63 cells and human primary osteoblast-like cells. Supernatants from activated but not resting T cell cultures efficiently induced apoptosis of MG63 cells and primary osteoblast-like cells. Supernatants from activated T cell cultures, incubated with EHDP, exhibited significantly less cytotoxicity than did supernatants incubated in the absence of EHDP. In contrast, the cytotoxicity of activated T cell culture supernatants was not affected by direct treatment of human osteoblasts with EHDP. The concentration of soluble Fas ligand in activated T cell culture supernatants was actually increased by EHDP. However, EHDP did not influence soluble Fas and tumor necrosis factor-alpha concentrations in the supernatant. Furthermore, treatment of human osteoblasts with EHDP did not alter their expression of Bcl-2/Bcl-xL or their sensitivity to anti-Fas immunoglobulin M-induced apoptosis. Our results suggest that EHDP inhibits the production of soluble factor that induces apoptosis of human osteoblasts and thus exhibits a protective action toward human osteoblast apoptosis induced by activated T cell culture supernatants. Although the exact EHDP-regulated molecule that induces apoptosis of human osteoblasts is unknown at present, our study may explain part of the therapeutic action of bisphosphonates in RA complicated by bone loss.     

Whole-genome analysis of Salmonella enterica serovar Typhimurium T000240 reveals the acquisition of a genomic island involved in multidrug resistance via IS1 derivatives on the chromosome

Salmonella enterica serovar Typhimurium is frequently associated with life-threatening systemic infections, and the recent global emergence of multidrug resistance in S. enterica isolates from agricultural and clinical settings has raised concerns. In this study, we determined the whole-genome sequence of fluoroquinolone-resistant S. enterica serovar Typhimurium T000240 strain (DT12) isolated from human gastroenteritis in 2000. Comparative genome analysis revealed that T000240 displays high sequence similarity to strain LT2, which was originally isolated in 1940, indicating that progeny of LT2 might be reemerging. T000240 possesses a unique 82-kb genomic island, designated as GI-DT12, which is composed of multidrug resistance determinants, including a Tn2670-like composite transposon (class 1 integron [intI1, bla(oxa-30), aadA1, qacEΔ1, and sul1], mercury resistance proteins, and chloramphenicol acetyltransferase), a Tn10-like tetracycline resistance protein (tetA), the aerobactin iron-acquisition siderophore system (lutA and lucABC), and an iron transporter (sitABCD). Since GI-DT12 is flanked by IS1 derivatives, IS1-mediated recombination likely played a role in the acquisition of this genomic island through horizontal gene transfer. The aminoglycoside-(3)-N-acetyltransferase (aac(3)) gene and a class 1 integron harboring the dfrA1 gene cassette responsible for gentamicin and trimethoprim resistance, respectively, were identified on plasmid pSTMDT12_L and appeared to have been acquired through homologous recombination with IS26. This study represents the first characterization of the unique genomic island GI-DT12 that appears to be associated with possible IS1-mediated recombination in S. enterica serovar Typhimurium. It is expected that future whole-genome studies will aid in the characterization of the horizontal gene transfer events for the emerging S. enterica serovar Typhimurium strains.     

Interleukin 10 and interferon gamma regulation of experimental Trypanosoma cruzi infection

Studies were undertaken to determine whether interleukin 10, (IL-10) a cytokine shown to inhibit interferon gamma (IFN-gamma) production, was involved in Trypanosoma cruzi infections in mice. Exogenous IFN-gamma protects mice from fatal infection with T. cruzi. Furthermore, resistant B6D2 mice developed fatal T. cruzi infections when treated with neutralizing anti-IFN-gamma monoclonal antibody (mAb). Thus, endogenous as well as exogenous IFN-gamma is important in mediating resistance to this parasite. Because both T. cruzi-susceptible (B6) and -resistant (B6D2) mouse strains produced IFN-gamma during acute infection, we looked for the concomitant production of mediators that could interfere with IFN-gamma-mediated resistance to T. cruzi. We found that IL-10-specific mRNA was produced in the spleens of mice with acute T. cruzi infections. In addition, spleen cell culture supernatants from infected B6 mice, and to a lesser extent B6D2 mice, elaborated an inhibitor(s) of IFN-gamma production. This inhibitor(s) was neutralized by anti-IL-10 mAb. These experiments demonstrated the production of biologically active IL-10 during T. cruzi infection. In further studies in vitro, it was shown that IL-10 blocked the ability of IFN-gamma to inhibit the intracellular replication of T. cruzi in mouse peritoneal macrophages. Thus, in addition to its known ability to inhibit the production of IFN-gamma, IL-10 (cytokine synthesis inhibitory factor), may also inhibit the effects of IFN-gamma. These experiments demonstrate that IL-10 is produced during infection with a protozoan parasite and suggest a regulatory role for this cytokine in the mediation of susceptibility to acute disease.     

细菌Ⅳ型分泌系统的研究进展

革兰阴性细菌的分泌系统有Ⅰ~Ⅵ型,其中Ⅳ型分泌系统(Type Ⅳ Secretion System,T4SS)不但可以介导DNA的水平转移,还可以转运蛋白质及核糖核蛋白复合物等大分子物质。T4SS通过介导抗性基因或毒力基因水平转移有利于细菌进化或直接将效应蛋白分子转运至宿主细胞,参与细菌致病。本文除介绍T4SS的类型、结构、生物学功能等方面的研究进展外,还介绍了基于蛋白相互作用及生物信息学方法的T4SS分泌效应蛋白的识别方法。     

河弧菌AL536_RS29525基因功能研究

  目的  探讨河弧菌基因组中VflT6SS2核心基因簇上游paar基因簇中AL536_RS29525的序列特征、对VflT6SS2分泌功能和杀菌活性的影响以及可能的调控机制。  方法  利用Muscle、GeneDoc软件进行AL536_RS29525基因编码产物的序列特征分析;同源重组技术构建AL536_RS29525的缺失株,PCR扩增AL536_RS29525编码序列克隆于pSRKTc获得回补质粒pSR-29525,继而导入?AL536_RS29525得到回补株;Western Blot （WB）检测相应菌株中VflT6SS2 Hcp蛋白的表达和分泌,以大肠埃希菌为prey的细菌竞争/杀菌实验检测VflT6SS2介导的菌株杀菌能力;基于Lux报告基因的启动子融合系统冷光检测确定AL536_RS29525缺失对VflT6SS2核心基因簇启动子和hcp启动子活性的影响;荧光定量反转录聚合酶链式反应（qRT-PCR）检测hcp （tssD2）和vipA （tssB2） mRNA的相对表达水平。  结果  AL536_RS29525同源基因编码蛋白的结构和功能较为保守;缺失AL536_RS29525负性影响VflT6SS2 Hcp蛋白的表达及分泌,降低VflT6SS2介导的菌株杀菌能力,回补AL536_RS29525可恢复缺失株 Hcp 的表达、分泌和杀菌能力;缺失株?AL536_RS29525中hcp （tssD2）和vipA （tssB2）的mRNA表达量均低于野生株;而VflT6SS2的核心基因簇启动子和hcp启动子活性在?AL536_RS29525缺失株和野生株之间无显著差异。  结论  河弧菌AL536_RS29525基因较为保守,与霍乱弧菌以及弗尼斯弧菌的同源基因均具有较高的同源性。 AL536_RS29525基因是河弧菌VflT6SS2的重要组成部分,为其Hcp效应子的正常表达、分泌功能以及VflT6SS2介导的杀菌活性所必需。AL536_RS29525可能转录后水平影响VflT6SS2的功能表达。