Aerobic bacteria from mucous membranes, ear canals, and skin wounds of feral cats in Grenada, and the antimicrobial drug susceptibility of major isolates

In a 2-year period 54 feral cats were captured in Grenada, West Indies, and a total of 383 samples consisting of swabs from rectum, vagina, ears, eyes, mouth, nose and wounds/abscesses, were cultured for aerobic bacteria and campylobacters. A total of 251 bacterial isolates were obtained, of which 205 were identified to species level and 46 to genus level. A commercial bacterial identification system (API/Biomerieux), was used for this purpose. The most common species was Escherichia coli (N = 60), followed by Staphylococcus felis/simulans (40), S. hominis (16), S. haemolyticus (12), Streptococcus canis (9), Proteus mirabilis (8), Pasteurella multocida (7), Streptococcus mitis (7), Staphylococcus xylosus (7), S. capitis (6), S. chromogenes (4), S. sciuri (3), S. auricularis (2), S. lentus (2), S. hyicus (2), Streptococcus suis (2) and Pseudomonas argentinensis (2). Sixteen other isolates were identified to species level. A molecular method using 16S rRNA sequencing was used to confirm/identify 22 isolates. Salmonella or campylobacters were not isolated from rectal swabs. E. coli and S. felis/simulans together constituted 50% of isolates from vagina. S. felis/simulans was the most common species from culture positive ear and eye samples. P. multocida was isolated from 15% of mouth samples. Coagulase-negative staphylococci were the most common isolates from nose and wound swabs. Staphylococcus aureus, or S. intemedius/S. pseudintermedius were not isolated from any sample. Antimicrobial drug resistance was minimal, most isolates being susceptible to all drugs tested against, including tetracycline.     

A cross-seasonal comparison of active and total bacterial community composition in Arctic tundra soil using bromodeoxyuridine labeling

Arctic soil microorganisms remain active at ecologically relevant rates in frozen soils. We used bromodeoxyuridine (BrdU) labeling and terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA gene amplicons to examine active bacterial communities in two Alaskan tundra soils collected in summer and winter of 2005. Active community T-RFLP profiles were compared to total community profiles to determine if active bacteria were a subset of the total community. In shrub soils, active bacteria communities differed in composition between summer and winter, and winter-active bacterial taxa were not detected in the total community, suggesting that they are likely rare within the overall community. In contrast, tussock tundra soil contained more bacterial taxa that were active in both summer and winter and also represented a large portion of the total community. Using in silico digest of a sequence library from this site, we attempted to identify the dominant organisms in our samples. Our previous research suggested that the total microbial community was stable throughout the year, but this new study suggests that the active community is more dynamic seasonally. In general, only a subset of the total community was growing at a given time. This temporal niche partitioning may contribute to the high diversity of microbial communities in soils. Understanding which taxa contribute to microbial function under different conditions is the next frontier in microbial ecology and linking composition to biogeochemical cycling.     

重组溶菌酶质粒pcDNAKLYZ治疗泌乳期奶牛乳房炎

通过比较注射人溶菌酶重组质粒pcDNAKLYZ的隐性乳房炎奶牛注射前后的奶样中细菌计数结果,对重组溶菌酶基因工程质粒治疗奶牛乳房炎的效果进行分析。对乳房炎患牛的156个乳区治疗前后312份奶样进行细菌培养,其中在注射前的乳样的培养结果中,阴性率为0（0/156）,菌落数在50以内的比率为12.82%（20/156）,在51～100的比率为16.67%（26/156）,大于等于100的比率为70.51%（110/150）;在注射人溶菌酶的重组质粒pcDNAKLYZ后的奶牛乳样的培养结果中,阴性率为51.92%（81/156）,菌落数在50以内的比率为45.51%（71/156）,菌落数在51～100的比率为0%（0/156）,大于等于100的比率为2.56%（4/156）。因此,从细菌计数结果来看,重组质粒组的阴性及小于50的比率（97.44%）远高于治疗前（12.82%）,重组质粒的抑菌效果显著（P〈0.05）,该重组质粒对奶牛乳房炎具有较好的治疗效果。     

Studies on the mechanism of polyuria induced by cortisol excess in the dog

Summary

Water balance studies were performed in 7 experimental dogs before and during a period of cortisol‐induced polyuria and in one dog with spontaneous hyperadrenocorticism before and after removal of an adrenocortical carcinoma. Measurements of urine and plasma osmolality and plasma arginine vasopressin concentration were made at regular intervals during the water deprivation studies. The results indicate that cortisol does not block the release of vasopressin but interferes with its action in the kidney.     

抑真菌的乳酸菌在酸奶生产中的应用

为了提高酸奶的防霉效果,本研究采用抑真菌的乳酸菌进行酸奶发酵生产。通过对比保加利亚乳杆菌、嗜热链球菌的单菌发酵及添加抑真菌乳酸菌的混菌发酵发现,添加抑真菌乳酸菌的发酵酸奶,在凝乳时间、pH值、色泽、滋味和气味、组织状态等方面变化不显著(P>0.05);而在坚实度、稠度、黏度和黏性指数方面因菌株的不同而有所差异。向发酵后的酸奶中添加霉菌孢子悬液,结果发现添加抑真菌乳酸菌组的霉菌长出时间明显长于对照组。所以,将抑真菌乳酸菌应用于酸奶发酵,在不改变(或优化)原有酸奶特性的前提下可延长酸奶的保质期,但安全性方面还有待评估。     

耐高浓度铬(Ⅵ)细菌的分离筛选和鉴定

[目的]筛选耐高浓度Cr(Ⅵ)的细菌。[方法]以江苏某电镀厂排污口含Cr(Ⅵ)污泥为分离对象,采用选择压力法分离筛选出一批耐Cr(Ⅵ)细菌,测定分离得到的菌株耐不同浓度Cr(Ⅵ)的能力,并对9株高耐Cr(Ⅵ)细菌的分类地位进行了确定。[结果]从Cr污染土壤中筛选出26株能够耐受Cr(Ⅵ)的细菌,其中有9株细菌能够耐受300 mg/L及以上浓度的Cr(VI)。常规生理生化试验和16S rDNA测序结果表明,这9株细菌分别属于下列6个属:Arthrobacter、Bacillus、Ochrobactrum、Microbacterium、Amycolatopsis、Pusillimonas。[结论]这9株细菌在Cr(Ⅵ)污染生境的修复中存在潜在的应用价值。     

热生物处理法在奶牛场与牛奶加工厂废水COD指标处理效果

为了解热生物处理法在奶牛场与牛奶加工厂废水处理中的应用效果,通过利用在高温条件下发挥高效率的嗜热微生物与常温下具有活性的微生物组合,在相应的容器内进行曝气降解,对水质COD指标进行检测。结果显示:奶牛场和牛奶加工厂的污水经过热—温循环生物处理后,CODcr值明显下降,从初始的2896mg/L和2602 mg/L分别降至800.3 mg/L和870.3 mg/L。结果说明处理效果比较显著,对于牛奶加工厂洗涤用高温废水,尤为适用。     

中国林蛙皮肤抗菌肽的分离纯化及部分特性研究

从长白山林蛙养殖场购买林蛙 ,用冷水清洗林蛙 ,断头后迅速剥离皮肤 ,清洗血液后剪碎 ,经 80 %的甲醇抽提 3次 ;再经组织捣碎机捣碎 ,用 80 %的甲醇抽提 2次 ;再经葡聚糖凝胶过滤。实验结果表明 ,林蛙皮肤中小分子活性多肽经葡聚糖凝胶过滤得到纯度较高的抗菌活性肽 ;林蛙皮肤中小分子活性多肽对革兰氏阳性细菌、革兰氏阴性细菌都具有一定的抗菌作用 ;经醋酸纤维薄膜电泳 ,表明其具有较强的阳离子特征 ;SDS - -PAGE电泳分析表明为单一区带 ,林蛙皮肤中小分子抗菌活性多肽的相对分子量为 6 .2 8ku。     

Rangeland Monitoring: Water Quality and Riparian Systems

Ecological concepts serve as a foundation for developing a monitoring program to evaluate water quality and associated riparian systems. Ecological concepts used for developing a monitoring plan must be supported by scientific literature and related to streamflow dynamics and channel interactions. These interactions help determine natural or background habitat quality within and along river longitudinal and environmental gradients from mountains through basins in the western United States. In addition stream size, position in the watershed, and flow are related to sediment sorting, channel bank strength, and channel configuration. These relationships determine channel substrate habitat for aquatic organisms and population diversity. These habitat features may be modified by a channel's ability to store and transport sediment and associated pollutants within a watershed's drainage pattern. Sediment supply, delivery, and timing are altered by differences in snowmelt along elevation gradients, runoff from convective storms, water development history, and stream channel succession. Potential impairment of reference or background aquatic habitat in the western United States is generally sediment related and should be greater in basin river segments and during base flow conditions. Impairment sources can be shown to originate in the steep and first order tributaries of foothill and basin watersheds, and not from valley slopes where supply must cross established riparian zones. Water column, substrate disturbance, and channel bank disturbances may alter amount of sediment and bacteria pollution measured in basins and during base flow conditions.