浣熊源粪肠球菌的分离鉴定与耐药性分析

为探究从四川某动物园1例病死浣熊肝脏中分离到的1株细菌的特性和耐药程度,本试验采用病原分离、革兰氏染色、生化鉴定、16S rRNA测序、致病性试验、药敏纸片扩散法及耐药基因扩增的方法对该分离株进行了形态学及生化鉴定、致病能力和耐药程度分析。结果显示,分离株在普通LB培养基上呈现表面光滑、圆形凸起、边缘整齐、针尖大小的半透明菌落。经革兰氏染色在油镜下观察到蓝紫色球菌,测序结果与GenBank登录号为KY003107.1粪肠球菌（Enterococcus faecalis）的同源性高达99.5%,形态学与生化鉴定特性与粪肠球菌特性相符。致病性试验表明,该菌可导致肝细胞肿胀、变性,具有一定的致病能力;药敏纸片和耐药基因扩增试验表明,该菌对14种常见的抗生素头孢西丁、头孢哌酮、头孢曲松、头孢吡肟、头孢噻肟、氨苄西林、卡那霉素、链霉素、奈替米星、丁胺卡那、阿奇霉素、红霉素、多西环素、四环素耐药,仅对万古霉素和庆大霉素中度敏感。四环素耐药基因tetC检测为阳性;tetM、tetA检测为阴性,氨基糖苷类耐药基因aac （6'）/aph（2″）检测为阳性,aph（3'）-Ⅲ、ant（6）-Ⅰ检测为阴性;大环内酯类耐药基因ermB检测为阳性,ermA、ermC检测为阴性;万古霉素耐药基因vanA、vanB和β-内酰胺类耐药基因TEM检测均为阴性。该试验从浣熊肝脏分离的粪肠球菌表现出多重耐药特性并具有一定的致病能力,结果可为动物园临床肠球菌感染的病例提供一定的药物选择参考,制定合理的感染防治方案。     

2株猪源益生性肠球菌对酸和胆盐及热的耐受性研究

为了筛选动物肠道中的有益优势菌,研究了2株分离自猪肠道的益生性屎肠球菌(E1,E7)的耐受特性。本试验设pH 2,2.5,3,4的4个处理组,以pH 7为对照组;设胆盐浓度分别为0.2%,0.4%,0.6%,0.8%,1%的5个处理组,以不含胆盐的培养液为对照组;温度设50,80,90℃,以37℃为对照,分别作用5,10,15,20 min,经该3种方法处理后各取100μL培养液用细菌稀释计数法测定活菌数。结果表明:E1,E7都有较强的耐酸能力,在pH 2时,作用2 h后仍能检测到活菌。胆盐浓度达到0.4%时,E1,E7仍有一定的耐受能力,随胆盐浓度升高至0.6%时,活菌数由108.2CFU/mL降到102.5CFU/mL。2菌株在不同温度下经不同作用时间处理后呈不同的生长态势。     

A DNA Hybridization Taxonomic Study of Enterococi from the Intestine of Silkworm

对健康桑蚕幼虫消化道内的部分分离细菌的ＤＮＡ碱基组成测定和ＤＮＡ－ＤＮＡ染色体杂交研究表明：这些分离细菌属于肠球菌属，并证实在健康桑蚕幼虫消化道内Ｅ．ｆａｅｃａｌｉｓ和Ｅ．ｃａｓ－ｓｅｌｉｆｌａｖｕｓ以及非乳糖发酵型Ｅ．ｆａｅｃａｌｉｓ菌菌株的存在     

阿鲁科尔沁草原牛乳中乳酸菌生物学特性的研究——肠球菌属等的鉴定（第2报）

本项研究从科尔沁草原的阿鲁科尔沁牧区南北4个苏木16个牧户中采集43个乳样。从43个乳样中分离到64株乳酸菌，对其中的47株进行鉴定，结果分离到肠球菌属（Enterococcus)13株，乳球菌属（Lactococcus)2株，片球菌属（Pedio-coccus)3株。对其中8株分离株进行了种的鉴定，结果为殊异肠球菌（E.dispar)1株，蒙特氏肠球菌（E.mundtii)1株，类鸟肠球菌（E.pseudoavium)1株，屎肠于菌（E.faecium)3株，乳球菌乳脂亚种（L.lactis subsp cremoris)1株，乳球菌乳亚种（L.lactis subsp Lactis)1株，嗜盐片球菌（P.halophilus)1株。通过研究发现，被鉴定菌株的生物学特性基本符合各属和种的鉴定标准，均属于中温性乳酸菌。     

Effect of probiotics, Enteroccus faecium, on tilapia (Oreochromis niloticus) growth performance and immune response

The aim of this study was to analyze the effect of a probiotic bacterium, Enterococcus faecium ZJ4 on growth performances and immune responses of tilapia (Oreochromis niloticus). The tilapias were treated with E. faecium ZJ4 at a final concentration of 1 × 10⁷ cfu ml^− 1 in aquaria water every 4 days. Six aquaria with three replicates for treated and controls were used. After 40 days, the tilapias supplemented with the probiotic showed significantly better final weight and daily weight gain (DWG) than those fed the basal diet (Control) (P < 0.05). There was no remarkable difference (P > 0.05) in the total serum protein, albumin content, globulin concentration and A/G ratio between the treated and control tilapias. The result of lysozyme activity assay was similar to these biochemical indexes. However, the complement component 3 content, myeloperoxidase (MPO) activity and the respiratory burst activity of blood phagocytes were higher (P < 0.05) in E. faecium treated tilapias (trial 1) than the controls.     

2株鸭源肠球菌的生物学特性的观察

对2株鸭源肠球菌临床分离株和1株粪肠球菌参考菌株的形态特征、培养特性、生理生化特性、对药物的敏感性等生物学特性进行了初步研究。结果表明,3个被检菌株在光学显微镜下呈球形、革兰氏阳性染色和链状排列方式,能在10℃、45℃和6.5%NaCl肉汤等条件下生长,能耐热60℃30min,其特性均符合肠球菌属的特征,各菌株生化反应特性均与粪肠球菌特性基本一致,3个菌株均可鉴定为粪肠球菌。药敏试验结果表明,3个菌株均对青霉素、万古霉素、庆大霉素、红霉素和氯霉素敏感而对四环素耐药。     

Comparison of Organic and Inorganic Fertilizers for the Pond Production of Walleye,Stizostedion vitreum

ABSTRACT

Walleye were stocked at 20 fry/m³ and raised for 45-47 days in earthen ponds that were fertilized with organic or inorganic fertilizers. Organically fertilized ponds received periodic doses of alfalfa meal and torrula yeast. Nitrogen and phosphorus levels of 600 ug/L and 30 ug/L, respectively, were maintained by twice-weekly additions of liquid fertilizers in ponds of the inorganic treatment. Growth, survival, and production offish were not affected by the fertilizer treatment. The use of inorganic fertilizers is recommended for the pond production of walleye because it is easier and less costly than traditional methods involving the use of organic fertilizers.     

湖南猪源粪肠球菌的分离鉴定及16S rDNA系统进化分析

从湖南各地送检至实验室的临床样本中分离到42株革兰氏染色阳性及过氧化氢酶阴性的球菌,其中78.6%来自于肺脏,菌落形态及染色镜检均与粪肠球菌参考株ATCC 29212相似,兰氏分群鉴定97.6%（41/42）为D群,生化特性符合粪肠球菌特征。16SrDNA测序鉴定显示：42个分离株与同步测序的ATCC 29212同源性在99.2%到100%之间,与所选择粪肠球菌参考序列的同源性在98.7%到100%之间,NCBI在线BLAST分析发现42株均与GeneBank收录的粪肠球菌序列同源性最高。湖南分离株16SrDNA序列与E.faecalis参考序列进化关系与地域分布无关,来源于不同宿主的菌株的16SrDNA变异并不大,而与E.faecium、E.canis、E.avium、E.hirae等4种肠球菌则有多处变异,这些变异区域在这4种肠球菌中却是保守的。     

肠球菌研究进展

肠球菌(Enterococcus)是革兰阳性、过氧化氢酶阴性球菌,是人和动物肠道内主要常存菌群.该菌可引起群体致病和医院交叉感染,临床上表现为尿路感染、菌血症、心内膜炎等,加之许多报道显示肠球菌对多种抗生素都有耐药性和具有较强的致病性,因此越来越受到人们的关注.论文从生物学特性、毒力因子、耐药性、流行病学、临床检测等方...     

Antimicrobial resistance in Swiss laying hens, prevalence and risk factors

Antimicrobial resistance is an emerging concern to public health, and food-producing animals are known to be a potential source for transmission of resistant bacteria to humans. As legislation of the European Union requires to ban conventional cages for the housing of laying hens on the one hand, and a high food safety standard for eggs on the other hand, further investigations about the occurrence of antimicrobial resistance in alternative housing types are required. In this study, we determined antimicrobial resistance in indicator bacteria from 396 cloacal swabs from 99 Swiss laying hen farms among four alternative housing types during a cross-sectional study. On each farm, four hens were sampled and exposure to potential risk factors was identified with a questionnaire. The minimal inhibitory concentration was determined using broth microdilution in Escherichia coli (n=371) for 18 antimicrobials and in Enterococcus faecalis (n=138) and Enterococcus faecium (n=153) for 16 antimicrobials. All antimicrobial classes recommended by the European Food Safety Authority for E. coli and enterococci were included in the resistance profile. Sixty per cent of the E. coli isolates were susceptible to all of the considered antimicrobials and 30% were resistant to at least two antimicrobials. In E. faecalis, 33% of the strains were susceptible to all tested antimicrobials and 40% were resistant to two or more antimicrobials, whereas in E. faecium these figures were 14% and 39% respectively. Risk factor analyses were carried out for bacteria species and antimicrobials with a prevalence of resistance between 15% and 85%. In these analyses, none of the considered housing and management factors showed a consistent association with the prevalence of resistance for more than two combinations of bacteria and antimicrobial. Therefore we conclude that the impact of the considered housing and management practices on the egg producing farms on resistance in laying hens is low.