细菌素抗菌作用机理及其应用

细菌素是微生物在代谢过程中通过核糖体途径合成的一类具有抗菌活性的多肽物质,对细菌素产生菌自身没有抑制作用。细菌素在自然界中普遍存在,30%~99%的细菌和古生菌可以产生至少一种     

简讯

1.Ent35-MccV,一种可广谱性地抑制革兰氏阳性和阴性细菌的新型细菌素细菌素和小菌素是核糖体合成的对亲缘关系很近的种属有抑制作用的一种抗菌肽。因此,细菌素对革兰氏阳性菌有抑制作用,而小菌素对革兰氏阴性菌有作用。作为临床药物或食品防腐剂,乳酸菌细菌素较窄的抑菌谱限制了这些肽的应用。阿根廷和意大利学者研制了一种新型的将enterocinCRL35和microcinV重组杂交结合起来的抑菌物质,命名为Ent35-MccV。在致病菌中,这种细菌素显示对肠出血性大     

葡萄球菌素及其应用研究进展

细菌素是由某些细菌产生的、由核糖体合成的一类对其他细菌有抑杀活性的蛋白类或多肽类物质,细菌素产生菌株同时进化了一套对自身细菌素有免疫的保护系统,使其不受自身细菌素的作用。葡萄球菌是医学和兽医学一种很重要的革兰阳性菌,由葡萄球菌产生的细菌素统称为葡萄球菌素。由于葡萄球菌素对其他微生物有广谱活性,并且在食品和农业方面具有潜在的应用价值,使其在近些年来逐渐成为研究热点。本文对葡萄球菌素的研究进展及其潜在应用前景加以论述。     

中药有效成分对细菌溶血素的抑制作用

在防制细菌性疾病方面,抗菌药物起着非常重要的作用,但是随着抗菌药物在临床上的广泛应用,细菌的耐药问题日益突出,给临床治疗带来极大困难。近年来,以中药抑制细菌毒力因子控制细菌感染的治疗策略已引起国内外学者的广泛关注。细菌溶血素是细菌产生的主要毒力因子之一,随着研究的不断深入,开发溶血素抑制剂成为解决细菌感染问题的关键。现针对中药对细菌溶血素的抑制作用进行综述,以期为临床治疗细菌性疾病提供理论依据。     

黏杆菌素在动物中的研究与应用

黏杆菌素是一类老的阳离子型药物,可以干扰细菌的细胞膜造成细菌死亡。其主要用于治疗革兰阴性菌引起的感染,对多重耐药革兰阴性菌的抗菌活性亦非常显著。目前,黏杆菌素在兽医临床上有比较广泛的应用。本文旨在对黏杆菌素的化学、药效学、药动学、治疗应用及耐药等方面进行综述,对该药的选择和合理应用提供参考。     

植物提取物对细菌毒力因子抑制作用研究进展

抗菌药物在防治细菌性疾病方面具有重要作用,但是抗生素的广泛使用而导致的耐药性给细菌性疾病的治疗带来了极大的困难。近年来,以毒力因子为作用靶部位的抗感染药物在控制细菌感染方面受到人们重视,特别是植物提取物对细菌毒力因子具有多方面的抑制作用而受到国内外研究学者的广泛关注。论文就植物提取物在抑制细菌内毒素、溶血素、肠毒素、神经氨酸酶以及与侵袭力相关的毒力因子方面的研究进展进行综述,以期为开发新型抗细菌性感染的植物成分提供理论基础。     

抗生素替代品的研发概况

<正>研究开发新型抗生素替代产品以减少抗生素的使用是一条可行之路。抗生素替代产品按作用方式可分为两类:一类是具有杀灭病菌作用、可直接替代抗生素的产品,如抗菌肽、细菌素、溶菌酶以及一些中药制剂等;一类是通过提高机体免疫力或破坏病     

抗生素替代品的研发概况

<正>研究开发新型抗生素替代产品以减少抗生素的使用是一条可行之路。抗生素替代产品按作用方式可分为两类:一类是具有杀灭病菌作用、可直接替代抗生素的产品,如抗菌肽、细菌素、溶菌酶以及一些中药制剂等;一类是通过提高机体免疫力或破坏病     

产细菌素猪链球菌的筛选及其基因簇功能分析

以猪链球菌的细菌素为研究目标,采用琼脂扩散法筛选出27株产类细菌素猪链球菌菌株,其中CZJYW024菌株的细菌素抑菌活性最强。使用细菌素检测引物(nisin A和scn A)对产类细菌素菌株进行检测,scn A和nisin A的携带率分别为33.3%和14.8%。初步纯化CZJYW024菌株的抑菌物质,提取物对马链球菌兽疫亚种ATCC35246的抑菌环直径达(23.30±0.20)mm,经有机酸、过氧化氢干扰试验及质谱鉴定,证实该抑菌物质属于羊毛硫细菌素家族,对热、pH和蛋白酶稳定,命名为suicin024。抑菌试验证实该基因缺失株抑菌活性消失,进一步分析发现suicin024包含10个开放阅读框,由scz基因簇编码。CZJYW024菌株经BALB/c小鼠模型证实为无毒株。本研究为该细菌素在动物制药和食品原料加工等抗生素替代品的研究和开发上提供理论依据。     

细菌胞外囊泡与宿主的互作机制研究进展

细菌胞外囊泡（BEVs）是一类由细菌分泌的可携带和转运各种物质的纳米级颗粒,在母源细菌与宿主互作中发挥重要作用。研究发现,BEVs可携带母源细菌源抗原成分参与免疫反应信号通路,实现对宿主的免疫调节作用,为疫苗开发提供了新思路;肠道中的BEVs可刺激黏蛋白产生,增强肠道屏障效应、降低肠道炎症,既能作为修复肠炎患者肠道屏障功能的潜在药物,也可作为评估肠道损伤情况的标志物;BEVs还可通过调节糖和脂质代谢的信号通路调节宿主代谢。反过来,宿主也能影响细菌及其BEVs的分泌。本文综述了BEVs的组成及其在宿主免疫调节、肠道屏障功能和代谢过程中作用机制,以期为BEVs在临床和生产应用中提供参考。     

Production of a bacteriocin‐like inhibitory substance by Leuconostoc mesenteroides subsp. dextranicum 213M0 isolated from Mongolian fermented mare milk,airag

Strain 213M0 was selected with productivity of a bacteriocin‐like inhibitory substance (BLIS) among 235 strains of lactic acid bacteria (LAB) isolated from Mongolian fermented milk ‘airag’. Strain 213M0 was species‐identified as Leuconostoc mesenteroides subsp. dextranicum by morphological observation, carbohydrate fermentation profiling and sequencing the 16S rRNA gene. Incubation temperature proper to produce the BLIS was 25°C rather than 30 and 37°C, and the production actively proceeded during the exponential growth phase of the producer cells. Antibacterial effect of BLIS 213M0 was limited to all nine strains of Listeria sp. bacteria and seven strains of LAB cocci among 53 tested strains, which corresponds to a typical feature of the class IIa pediocin‐like bacteriocins. BLIS 213M0 was not inactivated in every broad pH range solution (pH 2.0‐11.0), and was stable against storage at 25°C for 1 week and heating at 121°C for 15 min under pH 4.5. Peptide frame of BLIS 213M0 was confirmed by inactivation with some peptidases, and then its molecular weight was estimated to be 2.6‐3.0 kDa using an in situ activity assay following sodium dodecyl sulfate polyacrylamide gel electrophoresis. The estimated size was different from the other Leuconostoc bacteriocins already reported. These results suggest that BLIS 213M0 would be a novel listericidal bacteriocin.     

传统乳制品中-产细菌素乳酸乳球菌的筛选

采用平板挖井扩散法对从内蒙古传统乳制品中分离鉴定的34株乳酸菌的细菌素产生特性进行研究。在排除有机酸和过氧化氢的干扰后发现，一株乳酸乳球菌CB20—2的发酵上清液对革兰氏阳性60乳酸菌和非乳酸菌显示出抑菌活性，但对革兰氏阴性菌无抑菌作用。其蛋白特性及广谱抑菌性表明乳酸乳球菌CB20—2产生的抗菌物质是一种细菌素。     

抑制奶牛乳房炎源金黄色葡萄球菌的乳酸菌的筛选

为获得抑制奶牛乳房炎源金黄色葡萄球菌(S. aureus)的乳酸菌(LAB),本研究从新疆巴音布鲁克牧区鲜牛乳和哈萨克族乳制品奶疙瘩样品中分离培养LAB,通过传统的分离鉴定与16S rDNA基因序列测序相结合的方法鉴定LAB种类,同时以临床奶牛乳房炎源金黄色葡萄球菌S. aureus N2为指示菌,采用双层琼脂扩散法检测分离株的抑菌能力。通过测定生长曲线确定分离株的生长稳定期,进而利用硫酸铵沉淀法透析提取稳定期内分离株的细菌素,并检测其细菌素抑菌效价。结果显示:从样品中筛选获得5株能够抑制指示菌生长的LAB,分别为希氏乳杆菌、干酪乳杆菌、粪肠球菌、戊糖片球菌和乳酸乳球菌亚种。生长规律曲线表明20 h^30 h为5株LAB的稳定期,此期培养液pH值维持在3.8~4.5。从培养20 h的5株LAB上清液中提取到了细菌素,经检测其具有抑菌活性,抑菌效价分别为457 IU/mL、1 023 IU/mL、676 IU/mL、1 862 IU/mL和1 023 IU/mL。本研究结果表明5株LAB通过在生长稳定期内维持较低酸性环境(pH<4.5),代谢产生细菌素对乳房炎源S. aureus发挥抑制生长作用。本研究为S. aureus性奶牛乳房炎的生物防治提供了实验依据。     

Study on Physicochemical Properties of Lactobacillus plantarum DSM20174 Bacteriocin from Koumiss

To study the physicochemical properties extracted from koumiss of Lactobacillus plantarum DSM20174 bacteriocin,we purified the Lactobacillus plantarum DSM20174 bacteriocins and got the bacteriocin crude extractions after ammonium sulfate precipitation and dialysis.After purification with Sephadex G-100 gel column chromatography,bacteriocin specific activity apparently increased,reaching 154.70 AU/mL,yield was 43.5%.We detected the effects of purified Lactobacillus plantarum DSM20174 bacteriocin on bacteriostatic action of wild bovine pathogenic E.coli O78 by Oxford cup method under 3 different treatments.The results showed that:①In five groups of temperature treatments,the bacteriostatic action decreased with the increase of temperature,bacteriostatic actions of all groups were significantly different (P<0.05).Even after treatment at 121 ℃ 30 min,antimicrobial diameter was 14.90 mm.② After Lactobacillus plantarum DSM20174 bacteriocin were treated with pH 2.0 to pH 12.0,the higher of pH,the smaller of antibacterial diameter.The inhibitory effect of groups were significantly different (P<0.05) except pH 9.0 and pH 10.0.③Lactobacillus plantarum DSM20174 bacteriocins were treated by trypsin,pepsin and papain,antibacterial diameter apparently changed,bacteriostatic action was significantly different (P<0.05) before and after treatment.The results suggested that Lactobacillus plantarum DSM20174 bacteriocins were better antibacterial substances,but not thermal stability substances.It had a relatively wide pH range,and the smaller of pH,the stronger of its antibacterial activity,the antibacterial activity had been enhanced at optimum growth pH.It was not protease stability substances.     

酸马奶提取植物乳杆菌DSM20174细菌素的理化特性研究

为研究从酸马奶中提取的植物乳杆菌DSM20174细菌素的理化特性,本试验提纯植物乳杆菌DSM20174细菌素,经过硫酸铵沉淀、透析后得到细菌素粗提液,再利用SephadexG-100凝胶柱层析进行纯化后,细菌素的比活力明显增加,达到154.70 AU/mL,得率为43.5%.采用牛津杯法测定纯化的植物乳杆菌DSM20174细菌素在3种不同方式处理下对牛源野生致病性大肠杆菌O78抑菌效果的影响.结果显示:①植物乳杆菌DSM20174细菌素在5组温度处理下,随着温度的升高抑菌作用降低,各组抑菌作用差异显著(P<0.05).即使121 ℃处理30 min后,抑菌直径仍达14.90 mm.②植物乳杆菌DSM20174细菌素在pH 2.0~12.0由低到高的11组酸碱处理下,pH越大抑菌直径越小,且除了pH 9.0和pH 10.0之间差异不显著(P>0.05)外,其余各组抑菌作用均差异显著(P<0.05). ③植物乳杆菌DSM20174细菌素经胰蛋白酶、胃蛋白酶、木瓜蛋白酶3种酶处理后抑菌直径变化明显,处理前后抑菌作用均差异显著(P<0.05).结果表明植物乳杆菌DSM20174细菌素是较好的抑菌活性物质,但不是热稳定性物质;具有较广泛的pH适用范围,且pH越小时其抑菌活性越强,在最适生长pH时抑菌活性有所增强;不是蛋白酶稳定性物质.     

Bacteriocin production of probiotic Lactobacillus gasseri LA39 isolated from human feces in milk-based media

The use of bacteriocins from Lactobacillus gasseri , a probiotic lactic acid bacterium, as bio-preservatives in the food industry and animal formulations has been limited because few strains of Lb. gasseri are cultivated and produce a bacteriocin in natural media such as milk and milk-based media. By the determination of the growth-supplements to milk among the 47 nutrients, Lb. gasseri JCM1131^T, LA39 and LA158 isolated from human feces were successfully cultured in reconstituted skim milk and cheese whey using proteose peptone as a nutrient supplement, where Lb. gasseri LA39 produced a useful bacteriocin, gassericin A, with effective growth-inhibiting activity against Gram-positive food-borne pathogens. The data suggest these developed low-cost safe media supporting enough production of bacteriocins by the probiotic Lb. gasseri LA39 could be used to improve the safe bio-preservation of foods and therapy of bovine mastitis, and extra cheese whey produced by cheese making industry is reused in the cultivation for probiotics effectively.     

Detection of genes encoding virulence factors and bacteriocins in fecal enterococci of poultry in Portugal

Seventy-six Enterococcus isolates (43 E. faecalis, 30 E. faecium, two E. durans, and one E. hirae) recovered from fecal samples of poultry in a slaughterhouse (one isolate per fecal sample and one fecal sample per lot of animals) were studied for bacteriocin production and for the presence of genes encoding bacteriocins and virulence factors. The presence of genes encoding virulence factors (cpd, geE, fsr, ace, agg, and esp) and bacteriocins (entA, entB, entP, entQ, entAS-48, entL50A/B, cyl, and bac31) were studied by polymerase chain reaction in all enterococci. At least two virulence genes were detected in all 43 E. faecalis isolates, cpd and gelE being the most frequently detected genes (97.7%) followed by ace (62.8%), agg (39.5%), fsr (27.9%), and esp (2.3%). No virulence genes were detected in the other enterococcal species with the exception of one E. faecium and one E. durans isolates that harbored the gelE gene. Antimicrobial activity against eight indicator bacteria (including Listeria monocytogenes) was assayed in the enterococci, and 23 (30.3%) showed inhibitory activity against L. monocytogenes, the other 22 enterococci showing activity against indicator bacteria other than L. monocytogenes. Only the entA, entB, and cyl genes were detected in our study (entA + entB in nine E. faecium isolates and the cyl gene in seven E. faecalis isolates). A wide variety of virulence genes have been detected in fecal E. faecalis isolates from poultry, but not in the other enterococcal species. However, the presence of known bacteriocin structural genes is associated more with the E. faecium species.     

Production of bacteriocins by coagulase-negative staphylococci involved in bovine mastitis

In the present study, 188 coagulase-negative Staphylococcus (CNS) strains were isolated from bovine mastitis cases from 56 different Brazilian dairy herds, located in the Southeast region of the country, and were tested for antimicrobial substance production. Twelve CNS strains (6.4%) exhibited antagonistic activity against a Corynebacterium fimi indicator strain. Most antimicrobial substances were sensitive to proteolytic enzymes suggesting that they might be bacteriocins (Bac). Amongst the CNS producers, six were identified as S. epidermidis, two as S. simulans, two as S. saprophyticus, one as S. hominis and one as S. arlettae. Plasmid profile analysis of these strains revealed the presence of at least one plasmid. The Bac(+) strains presented either no or few antibiotic resistance phenotypes. Three strains were shown to produce a bacteriocin either identical or similar to aureocin A70, a bacteriocin previously isolated from an S. aureus strain isolated from food. The remaining Bac(+) strains produce antimicrobial peptides that seem to be distinct from the best characterised staphylococcal bacteriocins described so far. Some of them were able to inhibit Listeria monocytogenes, an important food-borne pathogen, and several strains of Streptococcus agalactiae associated with bovine mastitis, suggesting a potential use of these bacteriocins either in the prevention or in the treatment of streptococcal mastitis.     

细菌素作为绿色饲料添加剂的潜在性思考

细菌素是由细菌的核糖体产生的一类蛋白质或多肽类物质。由于细菌素可以对一些病原菌产生抑菌或杀菌的作用,所以可以考虑将其作为饲料添加剂用于提高动物免疫力,调整动物胃肠道菌群微生态平衡。文中从细菌素药效和毒性等多方面阐述了其作为绿色饲料添加剂的前景,并提出了仍需解决的问题。     

Update on the development of a novel dry cow therapy using a bismuth-based intramammary teat seal in combination with the bacteriocin lacticin 3147

: Public concerns over the widespread prophylactic use of antibiotics have led to a search for alternatives to dry cow therapy for the prevention of intramammary infections. A popular alternative is to infuse a teat seal at drying-off. The teat seal is a viscous non-antibiotic formulation and when it is infused into the teat canal and the teat sinus it forms an internal seal that provides a physical barrier to invasion by mastitis-causing pathogens. Enhancement of teat seal formulations may be achieved using non-antibiotic additives such as bacteriocins, potent proteins produced by some bacteria that have the ability to kill other microorganisms. This paper traces the history of investigations at Moorepark Research Centre into the efficacy of teat seal plus lacticin 3147, a bacteriocin produced by Lactococcus lactis DPC3147, in the prevention of intramammary infections in dry cows. Indications from on-going investigations are that a dry cow formulation combining the two products has considerable potential as a non-antibiotic prophylactic product.