溶磷细菌Enterobacteria sp EnHy-401对盐渍土壤中小麦生长的影响(英文)

盆栽试验结果表明,溶磷菌Enterobacteria sp.EnHy-401能较好地在盐渍土壤中定植,并对小麦的生长和矿质营养的吸收有促进作用。与对照相比,生长在经接菌处理盐渍土中的小麦,其地上部分和根系的干重增加了28.1%和14.6%,植株中对磷、钙、钾和镁的吸收率分别提高了34.4%、36.3%、31.5%、6.3%。该菌株所表现出来的对盐渍土壤中磷素有效性的提高、对小麦吸收K+、Ca2+、Mg2+、P等矿质营养的促进作用以及小麦生长与矿质营养元素吸收之间高度的相关性表明,溶磷菌株Enterobacteria sp.EnHy-401对盐胁迫下小麦生长的促进效应主要是通过改善盐渍土中部分矿质营养的供应,增强植株对P、Ca,Mg、K等营养元素的选择性吸收而实现,该效应受到土壤盐分和营养基质的影响。

Dominance of Enterobacteria among Histamine-Producing Bacteria Isolated from Indian Mackerel

Histamine fish poisoning (HFP) is a major illness occurring throughout the world due to the consumption of quality of deteriorated fish containing pre-formed histamine from bacterial activities. In the study reported here, the histamine-producing bacteria were isolated from the muscle, gills and the gut of 19 samples of Indian mackerel (Rastrelliger kanagurta) from Mumbai, India. The isolates from modified Niven’s medium (MNM) were confirmed for their ability to produce histamine by using 4 different pH-indicator media, followed by HPLC analyses. Out of 202 isolates, 63 isolates produced considerable amounts of histamine on at least 3 out of 4 media used in this study. The histamine formers were identified by biochemical tests followed by sequencing of their 16SrDNA gene, which showed that 89% of the isolates belonged to 13 different genera of the family Enterobacteriaceae. The non-enterobacterial histamine-producing bacteria belonged to the genera Staphylococcus, Alkaligenes, Shewanella and Psychrobacter.

Enterobacteria and Vibrio from Macrobrachium amazonicum prawn farming in Fortaleza,Ceará,Brazil

Objective:To investigate the isolation of enterobacteria associated with Macrobrachium amazonicum(M.amazonicum) farming and evaluate the in vitro antimicrobial susceptibility of Vibrio strains.Methods:Strains were isolated from female M.amazonicum prawns and environmental and hatchery water.Biochemical assays were used to identify bacterial genera and those belonging to the genus Vibrio were submitted to further analyses for species identification,through Vitek 2 automated system and scrotyping.Susceptibility test was performed according to Clinical Laboratory Standards Institute.Results:The following genera of enlerobacteria were recovered:Enterobacter(n=11),Citrobacter(n=10),Proteus(n=2),Serratia(n=2),Kluyvera(n=2),Providencia(n=2),Cedecea(n=1),Escherichia(n=1).Edwardsiella(n=1) and BulliauxeUa(n=1).As for Vibrio,three species were identified:Vibrio cholerae non-O1/non-O139(n=4).Vibrio vulnificus(V.vulnificus)(n=1) and Vibrio mimicus(n=1).Vibrio spp.showed minimum inhibitory concentrations values within the susceptibility range established by Clinical Laboratory Standards Institute for almost all antibiotics,except for V.vulnificus,which presented intermediate profile to ampicillin.Conclusions:Enterobacteria do not seem to be the most important pathogens associated with M.amazonicum farming,whereas the recovery of Vibrio spp.from larviculture,with emphasis on Vibrio cholerae and V.vulnificus,deserves special attention due to their role as potentially zoonotic aquaculture-associated pathogens.Furthermore,the intermediate susceptibility of V.vulnificus to ampicillin reflects the importance of monitoring drug use in prawn farming.

Enterobacterial Infections Diagnosed at the Clinic of Infectious Diseases of Fann Hospital (2013-2014) Dakar, Senegal

Introduction: Entero bacteria are mainly found in the gut of man and animals. The frequent acquisition of antibiotic resistance mechanisms explains why they are the bacteria most often implicated in human infectious pathology. It is estimated to be involved in 50% of sepsis, 60% of enteritis, 70% of urinary tract infection case. Objective: To determine the prevalence of enterobacterial infections diagnosed at Fann Infectious Diseases Clinic, and describe their epidemiological, clinical, therapeutic and evolutionary aspects. Patients and Methods: This is a retrospective and descriptive study, on patients hospitalized from January 2013 to December 2014, at Fann Infectious Diseases Clinic, with bacteriological confirmation of an enterobacteria infection. Results: A total of 129 cases were collected during the study period. The average age was 41 years, and female were predominant (60%) with a sex ratio of 0.67. Comorbidity was found in 88.4% of the cases, most of which were HIV infection. The most common clinical signs were infectious syndrome (53.49%) and general impairment (40.31%). The main gateway was urinary (55.8%). Samples were monomicrobial in 76.7% of cases. Klebsiella and Escherichia were the most common and 68.7% of the subjects had probabilistic treatment. Most enterobacterial strains were resistant to third generation cephalosporins (C3G), aminoglycosides to ciprofloxacin and cotrimoxazole. Aside from 4% of them, all were sensitive to imipenem. Conclusion: The advent of antibiotics has brought hope in the treatment of enterobacterial infections. However, an increase in their resistance to the usual antibiotics has been noted in recent years. As a result, the fight against antibiotic resistance must be a priority.

Phenotypic and Genotypic Characterization of Metallo-Beta-Lactamase and Extended-Spectrum Beta-Lactamase among Enterobacteria Isolated at National Public Health Laboratory of Brazzaville

The improper use of antimicrobials against infectious diseases has allowed microorganisms to develop defense mechanisms that give them insensitivity to these agents. All bacteria are concerned by this phenomenon. This work aimed to assess prevalence of beta-lactamase produced by enterobacterial isolates. Then, disc diffusion, double disc synergy test (DDST) and combined disc test (CDT) were respectively used for antimicrobial resistance, detection of Extended-Spectrum Beta-Lactamases (ESBL) and Metallo-Beta-Lactamases (MBL). bla genes were detected by PCR. A total of 132 enterobacterial strains were studied. Resistance to antibiotic families was observed with a greater frequency than 50%. Gentamicin was the least active beta-lactam antibiotic, with a resistance rate of 88%. 40.9% of strains show an ESBL phenotype and 16.6% were MBL. An overall prevalence of 74% (40/54) and respectively rates of 29.6%, 27.7% and 16.7% for blaSHV, blaCTX and blaTEM genes were observed. SHV, CTX, CTX/SHV/TEM, CTX/TEM, SHV/TEM and CTX/SHV were different ESBL genotypes observed. ESBL-producing enterobacteria isolation worried about the future of antimicrobial therapy in the Republic of Congo. This is a public health problem that requires careful monitoring and implementation of a policy of rational antibiotics use.

肠杆菌Enterobacteria sp.X57富集铀(Ⅵ)的初探

为开发可用于铀污染环境修复的优势微生物,本文考察了一株从铀污染场所分离的新型肠杆菌Enterobacter sp. X57在不同的环境因素下对铀的富集行为,并结合相关的表征探索了可能的生物富集机理。结果表明,Enterobacter sp. X57对铀的富集依赖于细菌的代谢活性,且受接触时间、pH值、温度、初始铀(Ⅵ)浓度以及共存离子等多种因素的共同影响。在铀初始浓度100 mg/L、温度303 K、pH=7.00条件下,Enterobacter sp. X57对铀的最大富集量约为175.52 mg/g(干重)。动力学研究结果表明,Enterobacter sp. X57富集铀的过程存在化学吸附、粒内扩散等多个阶段。傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能谱(EDS)以及X射线衍射(XRD)结果表明,溶液中的铀(Ⅵ)与细胞中的羧基、氨基、磷酰基等官能团发生络合,并同时扩散至胞内的细胞质膜上形成铀-磷酸盐矿物。上述结果表明,Enterobacter sp. X57对铀的富集是通过生物吸附和生物沉积矿化的协同作用实现的。

溶磷细菌Enterobacteria sp EnHy-401对盐渍土壤中小麦生长的影响

盆栽试验结果表明,溶磷菌Enterobacteria sp EnHy-401能较好地在盐渍土壤中定植,并对小麦的生长和矿质营养的吸收有促进作用。与对照相比,生长在经接菌处理盐渍土中的小麦,其地上部分和根系的干重增加了28.1%和14.6%,植株中对磷、钙、钾和镁的吸收率分别提高了34.4%3、6.3%、31.5%6、.3%。该菌株所表现出来的对盐渍土壤中磷素有效性的提高、对小麦吸收K+、Ca2+、Mg2+、P等矿质营养的促进作用以及小麦生长与矿质营养元素吸收之间高度的相关性表明,溶磷菌株Enterobacteria sp.EnHy-401对盐胁迫下小麦生长的促进效应主要是通过改善盐渍土中部分矿质营养的供应,增强植株对P、Ca,Mg、K等营养元素的选择性吸收而实现,该效应受到土壤盐分和营养基质的影响。

大黄乌梅汤保留灌肠治疗轻微肝性脑病的临床观察与机制研究

目的:探讨大黄乌梅汤保留灌肠治疗轻微肝性脑病的临床疗效与机制研究。方法:将34例确诊轻微肝性脑病且中医辨证湿热内蕴兼脾虚证的患者随机分为实验组和对照组各17例,两组均采用常规中西医综合基础治疗,实验组加用大黄乌梅汤保留灌肠;对照组加用利福昔明口服,共治疗两周。比较各组患者治疗前后的NCT-A评分、DST评分、IL-6、IL-1β、TNF-α、血氨、中医证候积分;收集治疗前后的新鲜粪便进行16S rDNA高通量焦磷酸测序检测。结果:两组患者治疗前后NCT-A评分、DST评分、IL-6、IL-1β、TNF-α、血氨、中医证候积分差异具有统计学意义(P<0.05)。与对照组相比,实验组患者治疗后中医证候改善、血氨降低、NCT-A评分、DST评分,IL-6和IL-1β降低差异具有统计学意义(P<0.05)。实验组患者治疗后Shannon指数升高(P=0.036)。结论:大黄乌梅汤保留灌肠能调节轻微肝性脑病患者的肠道菌群、减少促炎因子分泌、降低血氨、改善神经认知功能。

Pangenome analysis of Enterobacteria reveals richness of secondary metabolite gene clusters and their associated gene sets

In silico genome mining provides easy access to secondary metabolite biosynthetic gene clusters(BGCs)encoding the biosynthesis of many bioactive compounds,which are the basis for many important drugs used in human medicine.However,the association between BGCs and other functions encoded in the genomes of producers have remained elusive.Here,we present a systems biology workflow that integrates genome mining with a detailed pangenome analysis for detecting genes associated with a particular BGC.We analyzed 3,889 enterobacterial genomes and found 13,266 BGCs,represented by 252 distinct BGC families and 347 additional singletons.A pangenome analysis revealed 88 genes putatively associated with a specific BGC coding for the colon cancer-related colibactin that code for diverse metabolic and regulatory functions.The presented workflow opens up the possibility to discover novel secondary metabolites,better understand their physiological roles,and provides a guide to identify and analyze BGC associated gene sets.

耐盐解磷菌筛选鉴定及生理特性研究

磷是植物生长所必需营养元素,但磷元素利用效率较低,在盐碱土中表现更为突出。施用耐盐解磷微生物是提高盐碱地中磷利用率的有效方式。从黑龙江省齐齐哈尔市盐碱土壤中筛选耐盐碱解磷细菌,利用蒙金娜(PVK)培养基和溶菌肉汤(LB)培养基稀释涂布法,经多次分离纯化获得53株细菌,结合化学测定,最终获得一株解磷能力较强菌株P-W13,经透射电镜和分子生物学鉴定确定解磷细菌P-W13为肠杆菌属(Enterobacter sp.)。该菌株在培养144 h时解磷能力最强,为89.86 mg·L^(-1);该菌株可产生富马酸、丁二酸和丙酸,其中丙酸含量最高,其解磷能力与发酵液pH及菌株生长量之间存在极显著相关性,菌株P-W13在10%NaCl盐分浓度和pH为10时仍表现较强解磷能力;菌株P-W13产生吲哚乙酸(IAA)和胞外多糖含量分别为42.10和72.55 mg·L^(-1);此外,菌株PW13发酵液处理的种子发芽率、芽长、根长相比对照分别提高5.68%、68.35%、94.10%。研究筛选得到的肠杆菌属P-W13菌株具有较强解磷能力、耐盐碱性和植物促生作用,研究为盐碱地改良提供微生物菌种资源。

Biological properties of essential oil emphasized on the feasibility as antibiotic substitute in feedstuff

The discovery and application of antibiotics in animal feeds have boomed the development of intensive animal husbandry in the last century,until the emergence of antibiotics-resistant bacteria.To alleviate the risks aroused by antibiotics-resistant bacteria,effective antibiotic substitutes are urgently needed to replace antibiotics.Essential oils(EOs)derived from plants are illustrated as the promising antibiotic substitutes used in animal feeds,as same as their current views for poultry and livestock industries in the future.It has been widely demonstrated that the phytochemicals in EOs show multiple biofunctionability and are less likely to induce resistance in bacteria.The beneficial effects of EOs feed supplementation on the intestinal inflammation,intestinal flora,immunity,digestion,and growth performances have been already extensively examined.However,the cost-effectiveness,odor,volatility,instability and bioavailability are the challenges in effectively utilizing EOs in animal intestines.Based on previous researches,and these challenges can partially be resolved by microencapsulation and nanotechnology are promising techniques to deal with these challenges.This article presents the feasibility and foundation of EOs application as antibiotic substitutes in animal feeds,and illustrates the mechanisms,functional performances and superiority of EOs compared with antibiotics.

Novel Mannich Bases of Benzimidazole Derivatives: An Antibacterial Study of Environmental Bacterial Strains

A previous study was conducted on the synthesis and antibacterial evaluation of Mannich bases of 2-(thioalkyl)-1H-methylbenzimidazole derivatives. The results of this study showed that certain 2-(thioalkyl)-1H-methylbenzimidazole and 2-(thioalkyl)-methyl-1-(piperidin-1-ylmethyl)benzimidazole derivatives possess antibacterial activities against clinical strains, such as Escherichia coli, Klebsiella pneumonia (Gram-negative bacteria), Staphylococcus aureus and Pseudomonas aeruginosa (Gram-positive bacteria). Following these favorable results, we extended the antibacterial evaluation of this series of molecules to environmental strains. The aim of this study was to assess the impact of the methyl-piperidine group fixed at position-1 of this new series of benzimidazoles on the antibacterial activity of environmental strains. In addition, we first evaluated the antibacterial activity of four 2-(thioalkyl)methylbenzimidazole derivatives and then that of five 2-(thioalkyl)-methyl-1-(piperidin-1-ylmethyl) benzimidazole derivatives. This study allowed us to show that compounds 1d and 1e could inhibit bacterial growth in vitro of the Enterobacteria P1 strain with inhibition diameters of 17.3 ± 0.6 mm and 10 ± 0.0 mm, respectively. However, addition of methyl-piperidinyl in this series showed that five (5) of 2-(thioalkyl)-methyl-1-(piperidin-1-ylmethyl) benzimidazole derivatives had an inhibitory effect on the in vitro growth of bacterial strains used except on Enterobacteria P2 with inhibition diameters between 10.0 ± 0.8 mm and 27.9 ± 1.4 mm. The introduction of the methyl-piperidinyl group at the 1-position of 2-(thioalkyl)-1H-methylbenzimidazole derivatives greatly improved the antibacterial activity against environmental bacteria such as Escherichia coli A1, A2, A3, and A4 and two Enterobacteria P1.

Neonatal Thrombocytopenia at Dakar Principal Hospital

Neonatal thrombocytopenia accounts for 20% of neonates hospitalized in the neonatal intensive care unit (NICU) at DPH. The etiologies are multiple, but bacterial infection is the third leading cause of neonatal mortality worldwide. We therefore set out to assess the frequency of neonatal thrombocytopenia associated or not with bacterial infection in the NICU. We conducted a retrospective and prospective study with the DPH NICU, over 10 months (August 2018 and April 2019). Thrombocytopenia encountered in the NICUs, were the subject of research into bacteriological, inflammatory, and epidemiological parameters using Inlog laboratory data processing software. During this period, 1280 babies were hospitalized, 94 of whom underwent thrombocytopenia, corresponding to 7.34%, with a sex ratio of 0.92. The number of babies presenting with thrombocytopenia during the first week of hospitalization was 72, accounting for 76.6%. The clinical context was usually low birth weight in 30.8% of cases and perinatal asphyxia (25%). Thrombocytopenia ranged from 2000 to 137,000 with an average of 69,520/mm3. Among these thrombocytopenias, 64 cases (68%) were below 100,000 mm3 and 44 cases had a CRP >5 mg/l. A total of 30 bacteria were isolated, including 23 Enterobacteria, 2 Streptococci, and 1 Acinetobacter. Among these enterobacteria, 14 were multidrug-resistant (MDR). Thrombocytopenia associated with a multidrug-resistant bacterial infection is a real challenging management.

传统香肠中产生物胺肠细菌和乳酸菌分离方法的研究

研究建立了单层培养,双层显色分离产生物胺肠细菌和乳酸菌的方法,并分离到96株产生物胺肠细菌和58株产生物胺乳酸菌。经变性凝胶梯度电泳分析(PCR-DGGE)和PCR扩增测序后与Genebank数据库比对得知,这154株产胺菌属于5种菌,分别为屎肠球菌、粪肠球菌、阴沟肠杆菌、大肠埃希杆菌和产气肠杆菌。并采用特异性引物证明了产生物胺基因的存在。

温和灸腹部募穴对实验性大鼠肠道菌群失调的影响

目的通过温和灸关元、天枢两个腹部募穴,观察其对肠道菌群失调的影响。方法清洁级Wistar大鼠50只,雌雄各半,体重(200±20)g,采用随机对照方法分为正常组(A)、模型组(B)、药物组(C)、关元组(D)、天枢组(E),每组10只。用大量盐酸林可霉素灌胃造模,造模成功后,分别进行药物治疗和温和灸法治疗。1个疗程后,各组大鼠均被迫采取新鲜粪便0.1 g,应用双歧杆菌(BS)、乳酸杆菌(LBS)、肠杆菌(EMB)、肠球菌(EC)选择性培养基进行细菌培养,生化鉴定管和比浊法检测不同菌落生长情况和各组菌落数量。结果温和灸关元穴使BS、LBS数量有所增加,温和灸天枢穴使EMB、EC数量有所增加。结论温和灸不同部位的募穴可以选择性调整肠道优势益生菌群,从而治疗肠道菌群失调症。

大蒜对干发酵香肠中肠道菌的抑制作用研究

本文以植物乳杆菌6003作为乳酸菌发酵剂,以大肠菌O139和鼠伤寒沙门氏菌代表肠道菌,添加于模拟干发酵香肠肉汤中,通过不同浓度的大蒜对模拟肉汤影响研究,表明0.05%大蒜和0.1%大蒜即分别能有效延缓模拟肉汤中鼠伤寒沙门氏菌的增殖及大肠菌O139的增殖,1%的大蒜能完全阻止二种肠道菌在发酵期间的增殖。1%浓度大蒜对乳酸菌发酵剂没有抑制作用。

微量量热法研究左金丸与反左金丸对肠道菌群生长代谢的影响

目的从生物热动力学角度研究左金丸、反左金丸对肠道菌群生长代谢的影响,验证其客观差异性,探讨类方研究的新方法。方法采用微量量热法测定小鼠肠道菌群在不同浓度的左金丸、反左金丸作用下的生长代谢热谱曲线,以特征参数生长速率常数(k)、最大发热功率(Pmax)及达峰时间(Tp)、总产热量(Qt)和细菌抑制率(I)为指标,综合评价左金丸与反左金丸的活性差异。结果左金丸与反左金丸作用下的肠道菌群,随着药液浓度的增加,达峰时间Tp均延长;而左金丸与反左金丸对肠道细菌生长速率常数k值的影响却不同,与空白对照组比较,二者作用下的k值均减小,即两者均抑制肠道细菌的生长;由抑制率I可知,左金丸抑菌活性大于反左金丸。结论左金丸与反左金丸的抑菌活性存在客观差异性;微量量热法具有实时、在线、灵敏的特点,可快速、准确地评价类方的活性差异。

哺乳母猪肠杆菌PMQR基因的检测

【目的】探讨广东集约化猪场哺乳母猪肠杆菌质粒介导喹诺酮类耐药(PMQR)基因的存在情况及其与Ⅰ类整合子的流行相关性。【方法】通过PCR测序对分离自哺乳母猪的74株大肠杆菌和20株沙门氏菌进行PMQR(qnrA,qnrB,qnrS,aac(6')-Ib-cr,qepA)基因检测。对PMQR基因阳性株进行Ⅰ类整合酶intⅠ基因PCR检测。采用琼脂平皿二倍稀释法测定PMQR阳性株对14种抗菌药物的MIC值。【结果】在94株被测菌中,共检出PMQR阳性菌14(14.9%)株,其中qnrB阳性菌2株,qnrS阳性菌11株,aac(6')-Ib-cr阳性菌4株,有1株沙门氏菌Salmonella14同时携带qnrB,qnrS,aac(6')-Ib-cr3种PMQR基因,1株大肠杆菌E.coli2同时携带qnrB和aac(6')-Ib-cr。qnrA和qepA未有检测出。14株PMQR阳性菌均携带Ⅰ类整合子且耐药性普遍较为严重。【结论】哺乳母猪源的肠杆菌存在PMQR基因的流行,且以qnrS的检出率为最高。Ⅰ类整合子与PMQR基因同时存在,是导致哺乳母猪肠杆菌多重耐药的重要因素。

气相色谱-质谱法分析肠杆菌细胞脂肪酸

用气相色谱-质谱法分析了15种肠杆菌的全细胞酸性水解物,对结果中近30种脂肪酸初步化学定名13种,即 C_(11:0)、C_(12:0)、C_(13:0)、C_(14:0)、C_(15:0)、2OH-C_(14:0)、3OH-C_(14:0)、C_(16:1)、C_(16:0)、aC_(17:0)、△C_(17:0)、C_(18:1)和 D_(18:0),其中含量较高者为 C_(16:0)、C_(1(?):1)、C_(15:0)、C_(14:0)、C_(14:1)、C_(13:0)、3OH-C_(14:0)和 C_(1(?):0。肠杆菌细胞脂肪酸成分特征是以直链饱和和不饱和脂肪酸为主,C_(16:0)含量最高,而且均含有一定量的 3OH-C_(14:0),沙雷氏菌含2OH-C_(14:0),其他未知成分也具有一定特征。本结果为肠杆菌的化学分类学和分子细菌学研究提供了资料。

林麝肠道乳酸菌及肠杆菌多态性分析及耐药性研究

为研究林麝肠道中乳酸菌和肠杆菌基因型及表型多样性并对其耐药性进行分析,本研究从10头健康成年林麝粪便样品中分离到22株乳酸菌和16株肠杆菌,通过16S rDNA进化分析和生理生化测定对分离菌株进行了鉴定,采用脉冲场凝胶电泳(PFGE)技术分析了分离菌株的基因型并利用药敏纸片法进行了分离菌株的耐药性研究。本研究共分离到了11种细菌,分别为大肠杆菌Escherichia coli、阴沟肠杆菌Enterobacter cloaca、河生肠杆菌E.amnigenus、肺炎克雷伯氏菌Klebsiella pneumoniae、蒙氏肠球菌Enterococcus mundtii、耐久肠球菌E.durans、明串球菌Leuconostoc fallax、植物乳杆菌Lactobacillus plantarum、嗜酸乳杆菌L.acidipiscis、屎肠球菌E.faecium和食窦魏斯氏菌Weissella cibaria。其中大肠杆菌(n=11,28.9%)是林麝肠道中的优势菌群,肠球菌(n=10,26.3%)是林麝肠道中的优势乳酸菌群。PFGE分型结果表明肠杆菌分为7个基因型,乳酸菌分为9个基因型。本研究首次分析了林麝肠道中可培养细菌的基因型及表型并且对其耐药性进行了测定,结果表明林麝肠道中的原生菌群多态性明显,并且对目前常用的抗生素敏感,未检测到耐药菌株。