Antibiotic Resistance Profile of Enterococcus faecalis and Enterococcus faecium Isolates from Urine and Pleural Fluid in Two Hospitals of Cameroon

Enterococcus faecalis and Enterococcus faecium rank among the leading causes of nosocomial bacteremia and urinary tract infections. They often persist on hospital surfaces due to their ability to withstand adverse environmental conditions (low or high temperatures, high pH, and high salinity). The global Enterococcus faecalis-Enterococcus faecium ratio is currently shifting towards Enterococcus faecium. Enterococci present variable levels of resistance to certain families of antibiotics. This is the case for aminoglycosides, beta-lactams and cephalosporins. In 2017, WHO ranked Enterococci among priority pathogens for research and development of new antibiotics. The objective of our study was to determine the antibiotic resistance profile of Enterococcus faecalis and Enterococcus faecium isolates from urine and pleural fluid in two hospitals in Cameroon. This cross-sectional and analytic study was carried out between June to August 2023 on hospitalized and day patients in which a cytobacteriological test of urine and pleural fluid was done. The samples were inoculated on CLED Agar for urine and on Chocolate + polyvitex and blood agar (prepared from Columbia agar) for pleural fluid samples and incubated at 37℃ for 18 to 24 hours. Identification of isolates was carried out using the API 20 STREP micro gallery (Biomerieux, France) and tested for antimicrobial susceptibility. The data on socio-demographical and potential risk factors were recorded using self-administered questionnaires and data from laboratory analyses of the specimen were collected in a data capture sheet. Potential risk factors associated with the presence of Enterococci, were evaluated using the logistic regression in univariate and multivariate analysis. P value < 0.05 was considered as significant. A total of 511 patients were recruited who were predominantly females. Enterococcus spp were isolated in 27.79% of our samples with Enterococcus faecalis mostly encountered. Enterococcus spp showed a high level of resistance to penicilline (99.3% to Ampicilline), macrolides (66.2% to Erythromycin) and cyclines (85.2% to Doxycycline). Hospitalisation, access to health facilities, contact with urine specimen and hand hygiene practices were risk factors related to infection with Enterococcus spp while hospitalisation, health facility and hand hygiene were related to glycopeptide resistant Enterococcus. Strict compliance with hygiene rules and appropriate antibiotic consumption could help in the fight against these infections.

Pretreatment with probiotics Enterococcus faecium NCIMB 11181 attenuated Salmonella Typhimurium-induced gut injury through modulating intestinal microbiome and immune responses with barrier function in broiler chickens

Background:Preventing Salmonella infection and colonization in young birds is key to improving poultry gut health and reducing Salmonella contamination of poultry products and decreasing salmonellosis for human consumption(poultry meat and eggs).Probiotics can improve poultry health.The present study was conducted to investigate the impact of a probiotics,Enterococcus faecium NCIMB 11181(E.faecium NCIMB 11181)on the intestinal mucosal immune responses,microbiome and barrier function in the presence or absence of Salmonella Typhimurium(S.Typh-imurium,ST)infection.Methods:Two hundred and forty 1-day-old Salmonella-free male broiler chickens(Arbor Acres AA+)were randomly allocated to four groups with 6 replicate cages of 10 birds each.The four experimental groups were follows:(1)nega-tive control(NC),(2)S.Typhimurium,challenged positive control(PC),(3)the E.faecium NCIMB 11181-treated group(EF),(4)the E.faecium NCIMB 11181-treated and S.Typhimurium-challenged group(PEF).Results:Results indicated that,although continuous feeding E.faecium NCIMB 11181 did not obviously alleviate growth depression caused by S.Typhimurium challenge(P>0.05),E.faecium NCIMB 11181 addition significantly blocked Salmonella intestinal colonization and translocation(P<0.05).Moreover,supplemental E.faecium NCIMB 11181 to the infected chickens remarkably attenuated gut morphological structure damage and intestinal cell apoptosis induced by S.Typhimurium infection,as evidenced by increasing gut villous height and reducing intes-tinal TUNEL-positive cell numbers(P<0.05).Also,E.faecium NCIMB 11181 administration notably promoting the production of anti-Salmonella antibodies in intestinal mucosa and serum of the infected birds(P<0.05).Addition-ally,16S rRNA sequencing analysis revealed that E.faecium NCIMB 11181 supplementation ameliorated S.Typhimu-rium infection-induced gut microbial dysbiosis by enriching Lachnospiracease and Alistipes levels,and suppressing Barnesiella abundance.Predicted function analysis indicated that the functional genes of cecal microbiome involved in C5-branched dibasic acid metabolism;valine,leucine and isoleucine biosynthesis;glycerolipid metabolism and lysine biosynthesis were enriched in the infected chickens given E.faecium NCIMB 11181.While alanine,asparate and glutamate metabolism;MAPK signal pathway-yeast;ubiquine and other terpenoid-quinore biosynthesis,protein processing in endoplasmic reticulum;as well as glutathione metabolism were suppressed by E.faecium NCIMB 11181 addition.Conclusion:Collectively,our data suggested that dietary E.faecium NCIBM 11181 supplementation could ameliorate S.Typhimurium infection-induced gut injury in broiler chickens.Our findings also suggest that E.faecium NCIMB 11181 may serve as an effective non-antibiotic feed additive for improving gut health and controlling Salmonella infection in broiler chickens.

粪肠球菌(Enterococcus faecalis)和屎肠球菌(Enterococcus faecium)产生物胺交互作用研究

粪肠球菌和屎肠球菌是发酵香肠中常检出的2种主要的产酪胺和苯乙胺微生物。将粪肠球菌和屎肠球菌按照不同比例进行混合接种培养,发现在48h连续培养过程中,当粪肠球菌和屎肠球菌以1∶9比例混和接种培养时,体系pH值、细菌数量和酪胺生成量均显著低于其他各处理组;粪肠球菌有很强的产苯乙胺能力而屎肠球菌产苯乙胺能力较弱,当两者混合接种培养时,各混合体系的产苯乙胺水平相当,屎肠球菌产苯乙胺能力不受影响,而粪肠球菌产苯乙胺能力显著降低。

Enterococcus faecium NCIMB 10415 administration improves the intestinal health and immunity in neonatal piglets infected by enterotoxigenic Escherichia coli K88

Background:This study aimed to investigate the effects of oral administration of Enterococcus faecium NCIMB10415(E.faecium)on intestinal development,immunological parameters and gut microbiota of neonatal piglets challenged with enterotoxigenic Escherichia coli K88(ETEC).A total of 961-day-old sow-reared piglets were randomly assigned to 2 groups,with 48 piglets in each group.The piglets were from 16 litters(6 piglets each litter),and 3 piglets each litter were allocated to the E.faecium-supplemented(PRO)group,while the other 3 piglets were allocated to the control(CON)group.After colostrum intake,piglets in the PRO group were orally administrated with 3×10~9 CFU E.faecium per day for a period of one week.On day 8,one piglet per litter from each group was challenged(CON+ETEC,PRO+ETEC)or not(CON-ETEC,PRO-ETEC)with ETEC in a 2×2 factorial arrangement of treatments.On day 10(2 days after challenge),blood and tissue samples were obtained from piglets.Results:Before ETEC challenge,there were no significant differences for the average daily gain(ADG)and fecal score between the two groups of piglets.After ETEC challenge,the challenged piglets had greater fecal score compared to the non-challenged piglets,whereas E.faecium administration was able to decrease the fecal score.Piglets challenged with ETEC had shorter villous height,deeper crypt depth,and reduced number of goblet cells in the jejunum and decreased m RNA abundance of claudin-1 in the ileum,whereas increased the percentage of lymphocytes,concentrations of IL-1βin the plasma and TNF-αin the ileal mucosa,as well as increased the m RNA abundances of innate immunity-related genes in the ileum tissue.These deleterious effects caused by ETEC were partly alleviated by feeding E.faecium.In addition,piglets in PRO-ETEC group had decreased the percentage of CD8^+T cells of the peripheral blood when compared to those in CON-ETEC group.Moreover,E.faecium administration increased Verrucomicrobia at phylum level and decreased Bilophila at genus level.Conclusions:These results suggest that oral administration of E.faecium alleviated the intestinal injury and diarrhea severity of neonatal piglets challenged by ETEC,partly through improving the intestinal microbiota and immune response.This offers a potential strategy of dietary intervention against intestinal impairment by ETEC in neonatal piglets.

Enterococcus faecium AS8及其胞外多糖对发酵乳流变学特性的影响

通过红外光谱、气相色谱-质谱联用和流变仪的检测,探究产自屎肠球菌(Enterococcus faecium)AS8的胞外多糖(exopolysaccharide,EPS)(AS8-EPS)的结构组成和流变性能。采用3种发酵乳作为样品,分别为Streptococcus thermophilus+Lactobacillus bulgaricus、EPS+S. thermophilus+L. bulgaricus和E. faecium AS8。结果表明,在贮藏期间,不同发酵乳样品具有不同的流变学性质。同时,补充添加EPS和原位EPS对发酵乳流变性能具有不同的影响。通过Sephadex G-100和Sephadex G-50的分离纯化,获得2种多糖,分别为AS8-1-EPS和AS8-2-EPS。AS8-1-EPS主要单糖组成为甘露糖、葡萄糖和半乳糖(分别占59.1%、26.8%、7.9%),还有含量很少的其他单糖;AS8-2-EPS主要单糖组成为甘露糖、葡萄糖、半乳糖和鼠李糖(分别占65.4%、21.3%、8.9%、4.4%)。红外光谱检测结果表明AS8-1-EPS和AS8-2-EPS均为杂多糖。

Effect of Bacillus subtilis,Enterococcus faecium,and Enterococcus faecalis supernatants on serotonin transporter expression in cells and tissues

BACKGROUND Bacillus subtilis(B.subtilis),Enterococcus faecium(E.faecium),and Enterococcus faecalis(E.faecalis)are probiotics that are widely used in the clinical treatment of irritable bowel syndrome(IBS).Whether the supernatants of these three probiotics can improve gastrointestinal sensation and movement by regulating the serotonin transporter(SERT)expression needs to be clarified.AIM To investigate whether B.subtilis,E.faecium,and E.faecalis supernatants can upregulate SERT expression in vitro and in vivo.METHODS Caco-2 and HT-29 cells were stimulated with probiotic culture supernatants for 12 and 24 h,respectively.A male Sprague-Dawley rat model of post-infectious irritable bowel syndrome(PI-IBS)was established and the rats were treated with phosphate-buffered saline(group A)and three probiotics culture supernatants(groups B,C,and D)for 4 wk.The levels of SERT were detected by quantitative PCR and western blotting.RESULTS The levels of SERT at post-treatment 12 and 24 h were significantly elevated in Caco-2 cells treated with B.subtilis supernatant compared with those in the control group(aP<0.05).Those levels were markedly upregulated in Caco-2 cells stimulated with E.faecium and E.faecalis supernatants at 24 h(aP<0.05).In addition,SERT expression in groups B,C,and D was significantly higher than that in group A in the 2nd wk(aP<0.05).Increased SERT expression was only found in group D in the 3rd wk(aP<0.05).However,there was no significant difference in SERT expression between the groups in the last week(P>0.05).CONCLUSION The supernatants of B.subtilis,E.faecium,and E.faecalis can upregulate SERT expression in intestinal epithelial cells and the intestinal tissues in the rat model of PI-IBS.

中草药提取物对蜜蜂屎肠球菌(Enterococcus faecium)的抑制作用研究

为了观察中草药对蜜蜂屎肠球菌(Enterococcusfaecium)的体外抑菌效果,选用14种中草药按常规法制备水提物,用纸片法和试管二倍稀释法检测中草药水提物对蜜蜂屎肠球菌的抑菌作用。试验结果表明,所选14种中草药中9种对蜜蜂屎肠球菌有中度以上抑菌作用,其中大青叶的抑菌作用最强,其次是黄连、金银花、黄芪、黄芩、大黄、板篮根、淫羊藿和青蒿。

Isolation of Enterococcus faecium with Feeding Attractant Function from Pacific White Shrimp (Litopenaeus vannamei) Intestine

In the present study,we isolated the lactic acid bacterium strain SC-01 from Pacific white shrimp(Litopenaeus vannamei)intestine.Using conventional and molecular methods,we identified the bacterium as Enterococcus faecium,and found it had the function of feeding attractant and could inhibit the development of Vibrio parahaemolyticus(zone of inhibition:14 mm).The attractant effect of its fermentation broth is significantly better than that of the chemical attractant trimethylamine oxide(TMAO)(P<0.05),and is equivalent to that of dimethyl-beta-propiothetin(DMPT)based on the feeding behavior of shrimp.High performance liquid chromatography(HPLC)analysis suggested that inosine-5’-monophosphate(IMP)may be a component of the attractant.A biosecurity evaluation revealed a negative result in hemolytic assays,and no shrimp mortality was resulted from SC-01 fermentation broth challenge.Feeding trials(60 days)indicated that the SC-01 fermentation broth(viable counts:5.7×109 cfu mL−1)could improve feed intake,weight gain rate(WGR)and specific growth rate(SGR),and decrease the count of Vibrio sp.in the intestine of shrimp.

Identification of a New Peptide Deformylase Gene From Enterococcus faecium and Establishment of a New Screening Model Targeted on PDF for Novel Antibiotics

Objective To identify a new peptide deformylase (PDF) gene (Genebank Accession AY238515) from Enterococcus faecium and to establish a new screening model targeted on PDF. Methods A new PDF gene was identified by BLAST analysis and PCR and was subsequently over-expressed in the prokaryotic expression host E.coli Bl21(DE3). Over-expressed protein was purified for enzymatic assay by metal affinity chromatography and a new screening model was established for novel antibiotics. Result A new PDF gene of Enterococcus faecium was identified successfully. Ten positive samples were picked up from 8000 compound library and the microbial fermentation broth samples. Conclusion A new PDF of gene Enterococcus faecium was first identified and the model had a high efficacy. Positive samples screened may be antibacterial agents of broad spectrum.

泡菜源屎肠球菌Enterococcus faecium R2的环境胁迫耐受性及安全性评价

屎肠球菌R2是分离于泡菜中的优势产酸菌,可高效利用豆腐黄浆水中的低聚糖产酸制备酸浆,可作为一种新型酸浆纯种发酵剂。该文通过毒力基因检测、万古霉素耐药基因筛查、有害代谢产物实验来评价屎肠球菌R2的安全性,并进一步研究该菌株对外界环境的耐受性,为生产一种新型酸浆纯种发酵剂奠定基础并为其实际生产应用提供科学基础。结果表明,屎肠球菌R2的毒力基因检测和万古霉素耐药基因筛查及有害代谢产物检测结果均为阴性,也不会产生溶血现象;该菌株对外界环境中的酸性、胆盐及高渗透压耐受性较好且具有一定的自聚集性和疏水性。由此可见屎肠球菌R2具有安全性。

屎肠球菌Enterococcus faecium R2的分离鉴定及其在酸浆豆干加工中的应用

为了获得黄浆水发酵优势菌种,通过平板涂布法和发酵培养法,以p H值和生物量为指标,从泡菜中分离筛选出1株可以高效利用黄浆水发酵产酸的菌株R2,对其进行菌株形态观察、生理生化鉴定及分子生物学鉴定,确定菌株R2属于屎肠球菌。对屎肠球菌R2的安全性及其发酵酸浆的品质特性进行分析,结果表明,屎肠球菌R2对几种常见抗生素敏感,具有一定的安全性;屎肠球菌R2纯种发酵制得的酸浆豆干与自然发酵酸浆豆干相比感官特性无显著差异,说明屎肠球菌R2可以作为一种新型酸浆纯种发酵剂进行开发利用。该研究可为黄浆水的高效开发利用及酸浆豆干(腐)的规范化生产提供理论依据。

肠道细菌Phascolarctobacterium/Phascolarctobacterium faecium与2型糖尿病中代谢紊乱的关联分析

目的寻找新发2型糖尿病(type 2 diabetes mellitus,T2DM)中的差异菌群,并初步评估差异核心菌群在疾病代谢紊乱中的重要作用。方法选取2020年9-11月在成都中医药大学附属医院内分泌科就诊的30名T2DM患者与体检中心的30名健康者为研究对象,构成T2DM组与对照组(NC组)。收集2组志愿者的血液标本和粪便标本,血液标本用于葡萄糖、胰岛素和血脂类指标的检测,粪便标本用于肠道菌群的16SrRNA检测,之后结合生物信息学分析、Pearson相关性分析等统计学方法,对不同组间的T2DM血液指标和差异菌种进行分析;使用RT-qPCR验证前期小RNA谱筛选结果,并将筛选的差异菌与早期实验的脂质代谢组、miRNAs谱基因组数据进行多组学关联分析,构建多参数的ROC曲线模型。结果T2DM具有特异性的肠道菌群特征,考拉杆菌属(Phascolarctobacterium)与粪考拉杆菌(Phascolarctobacterium faecium,P.faecium)在患病前后差异具有统计学意义。Pearson相关性分析提示,P.faecium与高密度脂蛋白(high-density lipoprotein,HDL)(r=-0.78,P<0.001)、低密度脂蛋白(low-density lipoprotein,LDL)(r=-0.89,P<0.001)、胰岛素(r=-0.71,P<0.01)具有较强的负相关性。Phascolarctobacterium则与胰岛素(r=-0.67,P<0.001)、体质量指数(body mass index,BMI)(r=-0.64,P<0.001)具有一定的负相关性,所构建的基于Phascolarctobacterium/P.faecium、脂肪酸α-linolenic acid、miR-122-5p的联合指标的ROC曲线模型,能够比较准确地将T2DM患者与健康者区分,曲线下面积(area under curve,AUC)分别为0.928(P=0.001)与0.934(P<0.001)。结论T2DM患者具有特异性的肠道菌群分布,其中,Phascolarctobacterium菌属和P.faecium菌与疾病的代谢紊乱密切相关,两类细菌理论上可作为T2DM的核心菌。

耳穴压豆联合枯草杆菌二联活菌颗粒在心脏瓣膜置换术后腹胀患者中的应用效果

目的探析耳穴压豆联合枯草杆菌二联活菌颗粒在心脏瓣膜置换术后腹胀患者中的应用效果。方法选取2022年1月至6月于南昌大学第二附属医院心脏大血管外科100例行瓣膜置换术后腹胀患者作为研究对象,根据随机数字表法分为对照组和观察组,每组50例。对照组接受多潘立酮常规干预,观察组加用耳穴压豆联合枯草杆菌二联活菌颗粒干预,两组均干预1周。比较两组的护理效果、胃肠道症状消失时间(排气时间、排便时间以及肠胀气消失时间)以及安全性。结果观察组患者的总有效率高于对照组,差异有统计学意义(P<0.05)。观察组患者术后首次排气、排便时间以及肠胀气消失时间均短于对照组,差异有统计学意义(P<0.05)。两组患者术后并发症总发生率比较,差异无统计学意义(P>0.05)。结论耳穴压豆联合枯草杆菌二联活菌颗粒在心脏瓣膜置换术后腹胀患者中应用价值良好,可有效缩短患者术后排气时间、排便时间以及肠胀气消失时间,安全性尚可。

Comparative antimicrobial activity in Murrah buffalo (Bubalus bubalis) Heifers’ urine and urine distillate

Background:Murrah buffalo is a breed of water buffalo(Bubalus bubalis)reared for milk and meat,especially in Northern India.There are so many studies on the antimicrobial potential of the cow(Bos indicus)urine but buffalo urine has rarely been studied.This study was aimed to evaluate the antimicrobial activity in whole buffalo urine and its distillate.Methods:Urine specimens were collected from seven Murrah buffalo heifers in the morning over three days from all seven heifers and distillated to prepare urine distillate(UD).The antimicrobial activity was determined through 96 well microplate method diluting(1:1)urine and UD in Mueller Hinton liquid medium against 919 microbial strains belonging to 148 species of 49 genera(Candia,11 genera of Gram+ve bacteria,37 genera of Gram-ve bacteria).The test strains were taken from the repository,revived and tested for purity before testing.The test strains were of clinical origin(372),environmental origin(496)and also from reference strain repositories(51).Results:Of the 919 test strains,a total of 57.89%and 56.04%of the tested strains were susceptible to UD and urine,respectively.There was a no significant(p>0.4)difference in the antimicrobial activity of UD and urine against 919 strains of microbes,regardless of their genus,species,and Gram staining reaction.Similarly,there was no significant(p>0.4)difference between the susceptibility of bacterial and Candida strains to UD or urine.However,strains of clinical origin were more often resistant to buffalo UD and urine(p<0.01)than strains isolated from environmental sources irrespective of their Gram staining characteristics(p>0.05).A significantly(p<0.01)higher proportion of reference strains was susceptible to UD and urine than microbial strains of clinical and environmental origin.For buffalo urine and UD,the most susceptible strains were Stenotrophomonas maltophilia(13/13)followed by Citrobacter freundii(8/10);Salmonella enterica ssp.enterica(21/27),Geobacillus stearothermophilus(23/30),Staphylococcus aureus(13/17),and Paenibacillus larvae(7/10)strains.The most resistant strains belonged to Acinetobacter calcoaceticus(15/20)species followed by strains of Paenibacillus alvei(11/16),Edwardsiella tarda(20/30),Bacillus megaterium(7/11)and Escherichia coli(59/110)species.There was insignificant(p,>0.05)difference in susceptibility of strains of different species of the same genus;however,among all the Bacillus species strains of B.coagulans were the most susceptible(66.7%)and strains of B.megaterium were the least susceptible(36.4%),similarly Enterococcus faecium strains were more susceptible(68.2%)than strains of Enterococcus faecalis(38.9%),70%strains of P.larvae were susceptible to urine and UD but only 31.3%of strains of P.alvei were susceptible.Strains of Klebsiella pneumoniae and Raoultella terrigena,earlier belonging to the same genus Klebsiella,had comparable susceptibility to buffalo urine and UD.Conclusion:The study concluded that buffalo urine may be a potential antimicrobial and may be explored further for identification of active antimicrobial compounds in buffalo urine.

广东省2019—2023年耐万古霉素屎肠球菌检出率升高的时空变迀研究

目的分析近年广东省耐万古霉素屎肠球菌(VR-Efm)临床分离株的时空分布,探寻VR-Efm检出率上升的原因。方法回顾性分析2019—2023年广东省4个区域(珠三角、粤东、粤西、粤北)的38所医疗机构上报至广东省细菌耐药监测系统中VR-Efm检出情况、患者人口学特征及科室和标本分布等资料,同步分析世界卫生组织重点关注的ESKAPE中其他5种细菌的检出情况。结果广东省VR-Efm检出率从2019年1.4%(63/4543)上升至2023年21.3%(1351/6345),呈明显上升趋势,2023年44.7%(17所)的医疗机构VR-Efm检出率>20%;广东省4个区域VR-Efm检出率普遍上升,以珠三角地区为中心向周围辐射增长。ESKAPE整体由2019年10.1%升至2023年10.8%,其余5种病原体中,耐碳青霉烯类肺炎克雷伯菌检出率从2019年8.0%上升至2023年15.0%,耐碳青霉烯类鲍曼不动杆菌、耐甲氧西林金黄色葡萄球菌、耐碳青霉烯类铜绿假单胞菌和耐碳青霉烯类肠杆菌属检出率分别从2019年的61.6%、34.4%、21.2%、7.9%下降至2023年的58.2%、31.9%、21.0%、7.6%,皆有不同程度下降。ICU VR-Efm检出率(12.2%)高于门急诊(9.4%)、内科(9.2%)和外科(7.0%)等非ICU科室(均P<0.05)。VR-Efm检出率较高标本分别为尿(9.8%)、血(9.1%),其余标本检出率介于6.9%~9.6%。青少年患者VR-Efm检出率(4.4%)低于中老年患者(>9.4%,P<0.05)。结论近5年广东省VR-Efm检出率明显上升,可能与社区和医院获得的优势克隆传播有关。有条件的医疗机构应对入院患者开展VR-Efm的筛查,并对检出VR-Efm的患者采取有效防控措施,以遏制VR-Efm检出率在该区域的上升。

育雏育成期饲粮添加益生菌对蛋鸡生长性能、血清指标、肠道健康及后续生产性能的影响

旨在研究育雏育成期饲粮中添加屎肠球菌(EF)和枯草芽孢杆菌(BS)对蛋鸡生长性能、血清生化和肠道健康的影响及育雏育成期饲喂效果对产蛋期生产性能的影响。试验选取528只1日龄罗曼粉蛋鸡,采用2×2试验设计,BS包括两个添加量即0或200 mg·kg^(-1)(BS活菌数为:3×10^(10)CFU·g^(-1)),EF包括两个添加量,即0或200 mg·kg^(-1)(EF活菌数为:2×10^(9)CFU·g^(-1)),共分4个处理,每个处理6个重复,每个重复22只鸡。试验期共30周,在育雏育成期1~20周进行试验处理,产蛋期21~30周所有组饲喂基础饲粮,不进行益生菌处理。结果表明:1)添加BS和EF对蛋鸡1~20周料肉比(F/G)存在显著交互作用,表现为两种益生菌联合添加提高了F/G(P<0.05)。2)添加BS有降低20周血清谷丙转氨酶含量的趋势(P=0.067)。BS和EF对蛋鸡20周血清生化存在交互效应,表现为两种菌联合添加降低了血清总蛋白、血清高密度脂蛋白和总胆固醇的含量(P<0.05)。3)添加EF有提高20周血清生长激素的趋势(P=0.078)。4)添加BS和EF均提高了回肠的相对长度(P<0.05);添加BS有提高空肠绒毛高度(P=0.051)和提高隐窝深(P=0.069)的趋势;添加EF显著提高了空肠绒毛高度(P<0.05),有提高空肠隐窝深度的趋势(P=0.072)。5)添加BS显著提高了空肠黏膜Occludin mRNA的相对表达量(P<0.05),有提高Claudin-1 mRNA相对表达量的趋势(P=0.081)。6)添加BS有提高平均蛋重的趋势(P=0.077)。综上,饲粮添加BS可以提高蛋鸡育雏育成期生长性能,改善血清生化指标及促进肠道健康,并且育雏育成期添加效果可以提高产蛋期生产性能,其效果优于EF和两种益生菌联用。

屎肠球菌F11.1G菌剂对断奶羔羊生长性能、营养物质表观消化率、屠宰性能、瘤胃发酵和瘤胃微生物区系的影响

本试验旨在探究饲粮中添加屎肠球菌(Enterococcus faecium)F11.1G菌剂对卡拉库尔羊断奶羔羊生长性能、营养物质表观消化率、屠宰性能、瘤胃发酵和瘤胃微生物区系的影响。试验选取20只健康、2月龄、体重(21.0±1.0)kg的卡拉库尔羊断奶羔羊,按体重配对原则分为对照组和试验组,每组10只。对照组饲喂基础饲粮,试验组每只羊每天在基础饲粮中添加2.0 g屎肠球菌F11.1G菌剂。试验期75 d,其中预试期15 d,正试期60 d。正试期第1天晨饲前称重记为初始体重,于正试期的第45~52天进行营养物质表观消化率的测定;正试期第60天,每组选取5只试验动物空腹称重后进行屠宰,测定屠宰性能、瘤胃发酵参数和瘤胃微生物区系。结果表明:试验组净增重和平均日增重(ADG)均极显著高于对照组(P<0.01),平均日采食量(ADFI)显著高于对照组(P<0.05),料重比(F/G)极显著低于对照组(P<0.01);试验组酸性洗涤纤维(ADF)表观消化率显著高于对照组(P<0.05);试验组宰前活重和胴体重显著高于对照组(P<0.05),肝脏指数、瘤胃指数、小肠指数和大肠指数显著或极显著高于对照组(P<0.05或P<0.01),皱胃指数显著低于对照组(P<0.05);从瘤胃发酵指标来看,饲粮中添加屎肠球菌F11.1G菌剂后,瘤胃中乙酸、丁酸浓度和乙酸/丙酸显著升高(P<0.05);从瘤胃微生物区系来看,饲粮中添加屎肠球菌F11.1G菌剂后,提高了瘤胃菌群操作分类单元(OTU)数目、拟杆菌门、厚壁菌门和纤维菌门相对丰度,理研菌科_RC9_肠道群相对丰度与ADG和pH、氨态氮(NH3-N)、乙酸、丙酸、丁酸、戊酸浓度呈正相关。综上所述,饲粮中添加2.0 g屎肠球菌F11.1G菌剂可以提高断奶羔羊生长性能、ADF表观消化率,通过增加瘤胃中乙酸和丁酸浓度改善瘤胃发酵,提高瘤胃细菌OTU数目,增加瘤胃细菌门水平中拟杆菌门、厚壁菌门和纤维菌门相对丰度,并且理研菌科_RC9_肠道群相对丰度与ADG和瘤胃发酵参数呈正相关。

屎肠球菌对五指山断奶仔猪肠道健康及微生物群落的影响

本试验旨在研究屎肠球菌对五指山断奶仔猪肠道健康及微生物群落的影响及对断奶应激的缓解作用。试验选取初始体重为(3.79±0.24) kg的33日龄五指山未断奶仔猪18头,随机分为对照组、断奶组和屎肠球菌组,每组6头(公母各占1/2)。对照组仔猪不进行断奶处理,在33日龄时灌喂20 mL磷酸盐缓冲液(PBS),并饲喂母乳至38日龄;断奶组仔猪33日龄时灌喂20 mL PBS,35日龄断奶,并饲喂饲粮至38日龄;屎肠球菌组仔猪33日龄时灌喂20 mL屎肠球菌(灌喂量为1×109CFU/kg BW),35日龄断奶,并饲喂饲粮至38日龄。38日龄时,将所有试验猪进行屠宰,并测定其肠道形态、酶活性及微生物群落。结果表明:1)在各组初始体重一致的情况下,断奶组仔猪终末体重出现下降,而对照组和屎肠球菌组仔猪终末体重均有所提高。2)与对照组相比,断奶组仔猪十二指肠、空肠和回肠绒毛高度、绒毛宽度和绒毛表面积均极显著降低(P<0.01),十二指肠隐窝深度显著提高(P<0.05),十二指肠绒毛高度/隐窝深度(V/C)值极显著降低(P<0.01)。与断奶组相比,屎肠球菌组仔猪十二指肠、空肠和回肠绒毛高度、绒毛宽度和绒毛表面积均极显著提高(P<0.01),十二指肠隐窝深度显著降低(P<0.05),十二指肠V/C值极显著提高(P<0.01)。3)与对照组相比,断奶组仔猪十二指肠和回肠β-半乳糖苷酶活性显著降低(P<0.05),屎肠球菌组空肠和回肠α-淀粉酶活性显著或极显著提高(P<0.05或P<0.01)。与断奶组相比,屎肠球菌组仔猪十二指肠β-半乳糖苷酶活性显著提高(P<0.05)。与对照组和断奶组相比,屎肠球菌组仔猪各肠段脂肪酶活性均极显著提高(P<0.01)。4)与断奶组相比,屎肠球菌组仔猪回肠Chao1指数显著提高(P<0.05)。与对照组相比,断奶组仔猪回肠中变形菌门相对丰度明显提高,回肠中厚壁菌门相对丰度明显降低。与断奶组相比,屎肠球菌组仔猪回肠中厚壁菌门和罗姆布茨菌属相对丰度明显提高,结肠中乳杆菌属相对丰度明显提高,结肠中拟杆菌门相对丰度明显降低。综上所述,断奶前灌喂屎肠球菌菌液可通过改善五指山断奶仔猪肠道形态及菌群结构,并通过提高其肠道相关酶活性,缓解断奶对仔猪的负面影响,进而促进断奶仔猪健康生长。

屎肠球菌细胞外囊泡对小鼠生长性能、肠道形态和粪便菌群的影响

【目的】探究屎肠球菌细胞外囊泡(Enterococcus faecium extracellular vesicles,Efm-EV)对小鼠生长性能、免疫、肠道形态和粪便菌群的影响,为屎肠球菌作为微生物饲料添加剂在动物生产中的推广应用提供理论依据。【方法】将20只雄性C57BL/6小鼠随机分为对照组和试验组,每组10个重复,每个重复1只小鼠。试验期为5 d,试验组小鼠每隔1 d灌胃含有500 μg的 Efm-EV悬液,每只灌胃150 μL;对照组小鼠灌胃等量PBS溶液。记录小鼠每天的采食量、试验开始和结束时的体重,计算小鼠的平均日增重、平均日采食量、料重比。【结果】与PBS处理相比,Efm-EV处理小鼠的终末体重 、平均日增重、平均日采食量、料重比没有显著变化。Efm-EV处理小鼠的血清IgA和IgG水平与PBS处理小鼠相比显著下降(P<0.05),而小鼠血清IL-10水平显著提升(P<0.05),TNF-α无显著变化。与PBS处理相比,Efm-EV处理小鼠十二指肠绒隐比显著提高(P<0.05),而小鼠十二指肠绒毛高度、隐窝深度,空肠和回肠的绒毛高度、隐窝深度、绒隐比无明显变化。灌胃Efm-EV处理小鼠粪便菌群在门水平上提高了厚壁菌门(Firmicutes)的细菌数量,降低了拟杆菌门(Bacteroidetes)的细菌数量;在科水平上提高了毛螺菌科(Lachnospiraceae)的丰度,降低了Muribaculaceae科的丰度;在属水平上显著提高了小鼠瘤胃球菌科UCG009 (Ruminococcaceae UCG 009)的丰度(P<0.05)。【结论】灌胃Efm-EV能够提高小鼠机体的抗炎水平,改善小鼠十二指肠形态结构,提高瘤胃球菌科UCG009的相对丰度。

大曲中产阿魏酸酯酶菌株的筛选及其特性分析

目的从浓香型白酒大曲中分离筛选出一株产阿魏酸酯酶的菌株。方法将大曲样品中筛选出的11株菌进行划线纯化培养,进一步挑选出产阿魏酸酯酶酶活较强的菌株并鉴定,分析其安全性及生物学特性,最后对发酵产酶条件进行优化。结果得到一株产阿魏酸酯酶酶活较强的菌株为L-7,经鉴定为屎肠球菌(Enterococcus faecium)。经毒力基因检测、有害代谢产物实验结果均为阴性;生物学特性研究实验结果为:在16 h时生物量达到最大,耐最低pH为4,最高为11,NaCl质量分数为8%的条件下仍能生长,耐受最高的乙醇体积分数为13%;具有较好的安全性且有耐乙醇、耐盐、广泛的pH耐受性等优良性能。通过发酵产酶条件优化,该菌株产阿魏酸酯酶最佳发酵条件为:接种量为6%体积分数、培养温度32℃、转速160r/min、培养时间96 h;此时该菌株产阿魏酸酯酶的酶活为(44.68±0.05)U/L,较优化前提高了57.05%。结论本研究结果可为产阿魏酸酯酶的菌株筛选提供参考,且筛选所得屎肠球菌在提高浓香型白酒及其他发酵食品中阿魏酸含量及风味具有应用潜力。