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1.
Forty-four serologically and biochemically typable Haemophilus influenzae isolates from clinical specimens in Taiwan were subjected to analysis in their relationship with source of isolation and age distribution. It was found that all isolates from blood and cerebrospinal fluid were serotype b, biotype I, and all were in children less than 4 years of age. Serotypes b and e, biotypes I and III were encountered to have the highest incidence of infection caused by H. influenzae in this area. All H. influenzae isolates were further tested for susceptibility to several selected antibiotics. All strains of this organism were susceptible to erythromycin and chloramphenicol. All but two strains were susceptible to tetracycline, whereas more strains were resistant to carbenicillin, gentamycin, keflin, and penicillin. Thirty-four percent strains were found to be resistant to ampicillin and all were beta-lactamase producer. No direct correlation between ampicillin resistance and serotypes or biotypes was recognized.  相似文献   

2.
A hamster was inoculated with the SI-1 strain of Borrelia burgdorferi and subsequently served as a host to larval Ixodes scapularis Say. Approximately 68% of the nymphs resulting from the fed larvae were infected. Nymphs from this group were fed on uninfected hamsters, and 3 of 4 males and 6 of 6 females became infected. The infected hamsters were allowed to mate with uninfected partners to test for venereal transmission. Six infected females were mated with 6 uninfected males, whereas 3 infected males were mated with 6 uninfected females. None of the uninfected hamsters became infected after mating. Two protocols were used to determine if transplacental transmission of B. burgdorferi occurred. One group included 6 nonpregnant infected females that were subsequently mated and became pregnant. Three of the females were allowed to carry to full term, whereas the other 3 were killed prior to parturition. All fetuses and offspring were negative for B. burgdorferi based on cultures and monoclonal antibody assays. Another group of 6 females was infected via tick bite after becoming pregnant; those females were allowed to carry fetuses to birth and all were negative. Attempts at contact transmission of B. burgdorferi from 2 infected females to 2 uninfected male and 2 uninfected female hamsters and from 2 infected males to 2 uninfected male and uninfected female hamsters via urine or feces failed.  相似文献   

3.
Adult rabbits were trapped in the spring on an area of grass and broom in the east of Scotland. They were ear-tagged and a sample of males and females were fitted with radio-collars. These were followed for two months to see whether they used burrows or ground cover for shelter during the day. Rabbits found on the surface were disturbed to see whether they bolted to burrows or stayed on the surface. The population was then re trapped to measure the population density, which was estimated to be 12.6 adults/ha in March, allowing for an apparent trapping bias against older females. One hundred and twelve burrow entrances/ha were counted from random quadrats. Males were more likely to be found on the surface than females, and rabbits that were more often on the surface were less likely to bolt to burrows when disturbed. Even when rabbits did bolt to burrows they frequently left them shortly afterwards and returned to the cover of the broom. Males that were most often found on the surface were lighter in weight than those found in burrows. This was not the case for females.  相似文献   

4.
为了进一步扩大我国稻种资源,丰富水稻育种材料,引进了165份国际水稻研究所在非洲进行穿梭育种的水稻新株系,于2011年和2012年在湖北生态条件下进行稻瘟病抗性、白叶枯病抗性和褐飞虱抗性的评价。评价结果表明,在165份新株系中有14份株系在宜昌和恩施2个稻瘟病病圃鉴定均表现抗或中抗稻瘟病,有40份株系同时高抗或抗白叶枯病菌株ZHE173和GD1358,有19份株系抗或中抗褐飞虱,有7份株系同时抗白叶枯病和稻瘟病,有8份株系同时抗白叶枯病和褐飞虱,有1份株系同时中抗稻瘟病、褐飞虱和白叶枯病。部分材料正在作为中间材料用于水稻育种。  相似文献   

5.
2003年6月至2004年5月,通过底拖网作业收集鱼类标本对广西合浦儒艮国家级自然保护区及其邻近水域鱼类种数进行了调查,并走访当地鱼市进行实地调查.共记录到保护区及其邻近水域的鱼类14目41科57种,其中55种为硬骨鱼类,占总数的96.49%,另有2种软骨鱼类,占总数的3.51%.有41种为暖水性鱼类,占总数的71.93%.生态类型中底层鱼类共37种,占总数64.91%.区系特征以北太平洋和印度太平洋区系为主.掠夺性获取和开发以及环境污染是目前这一水域鱼类资源面临的最大威胁,针对以上威胁提出了相应的保护对策.  相似文献   

6.
A total of 520 Vibrio anguillarum strains, isolated from fish and the environment, were tested for their sensitivity to 20 different antibiotics. Most isolates were of European origin. The results were compared with data on the O-serogroup and plasmid contents. All strains were sensitive to neomycin, spectinomycin, nitrofurantoin, flumequine and oxolinic acid, while most strains were sensitive to streptomycin, Oxytetracycline, chloramphenicol, sulphonamides, trimethoprim, sulphonamides with trimethoprim, nalidixan, rifampicin, novobiocin and O/129. A major part of the strains were resistant to the macrolides, spiramycin and lincomycin. For ampicillin, cephalothin, and Colistin marked differences were recorded with respect to O-serogroup. Most O1 strains were resistant to Colistin and sensitive to ampicillin and cephalothin, while most O2 strains were sensitive to Colistin but resistant to ampicillin and cephalothin. Some antibiotic resistant strains carried plasmids but no conjugation experiments were carried out to detect possible R factors.  相似文献   

7.
Species of Enterobacter and Serratia were examined for deoxyribonucleic acid relatedness to Klebsielleae, to atypical erwiniae, and to other members of Enterobacteriaceae. Deoxyribonucleic acid hybridization and then hydroxyapatite chromatography was the technique used to assess relatedness. Strains of Enterobacter cloacae formed two separate hybridization groups that correlate with the presence or absence of yellow pigment. Pigmented E. cloacae were 75-100% related, but they were only 40-50% related to unpigmented strains. Conversely, unpigmented strains were 70% or more related but were only 40-50% related to the pigmented strains. Both pigmented and unpigmented E. cloacae were 40-45% related to Enterobacter aerogenes and klebsiellae, and 20-30% related to Serratia species and Enterobacter hafniae. Atypical erwiniae were highly related to E. cloacae. Serratia marcescens strains formed one closely related group. Serratia liquefaciens strains formed a single, more disperse, relatedness group, as did isolates of Serratia rubidaea. These species were related throughout a substantial portion of their genomes. A group of lysine-positive "Citrobacter-like" strains were 40-50% related to Serratia species. Only four E. hafniae strains were tested. Two of these were highly related, while the other two were only 50% related to the reference strain. Enterobacter hafniae was only 15-20% related to other Enterobacteriaceae.  相似文献   

8.
The level of susceptibility of 90 different Staphylococcus aureus strains to chosen quaternary ammonium compounds: cetyltrimethyl ammonium bromide, benzalkonium chloride and benzethonium chloride as well as to chlorhexidine digluconate were examined. The examined strains consist of three groups: hospital originated MRSA, hospital originated MSSA and non-hospital MSSA. The significant differences between these groups were observed in they susceptibility to the investigated disinfectants. The obtained MIC values showed that the most resistant were hospital MRSA strains, where 55% was estimated as resistant to cetyltrimethyl ammonium bromide, 72% were resistant to benzalkonium chloride and benzethonium chloride and 7% were resistant to chlorhexidine digluconate. Among hospital originated MSSA 3% of strains were resistant to cetyltrimethyl ammonium bromide and 6% were resistant to benzalkonium chloride and benzethonium chloride. 14% non-hospital S. aureus strains were resistant to benzalkonium chloride and benzethonium chloride. None were resistant to chlorhexidine digluconate or cetyltrimethyl ammonium bromide.  相似文献   

9.
THE TAXONOMY OF THE PSYCHROPHILIC MEAT-SPOILAGE BACTERIA: A REASSESSMENT   总被引:9,自引:9,他引:0  
SUMMARY: A study was made of selected properties of 189 psychrophilic bacteria isolated from chilled beef and associated sources. Of these, 182 were Gram-negative and 7 were Gram-positive. Of the former, 128 were typical pseudomonads with polar flagella. They were resistant to penicillin and oxidized glucose to acid. There were 52 non-motile Gram-negative bacteria of which 42 were judged to be pseudomonads on the basis of penicillin resistance and the oxidation of glucose to acid. Flagellar characters were associated with the production of green pigment, with the production of acid from lactose and with resistance to several antibiotics.  相似文献   

10.
大豆种质对SMV成株和种粒斑驳抗性的SSR标记辅助鉴定   总被引:1,自引:0,他引:1  
对186份大豆种质资源进行了成株和种粒斑驳抗性鉴定,并利用与成株抗性及种粒斑驳抗性分别相关的SSR标记验证抗病毒分子辅助选择的可行性。结果表明:接种SMV1,选出成株和种粒双抗种质38份,成株抗病种质149份,种粒抗病种质45份,成株和种粒双感种质26份。利用与成株抗性相关的SSR标记Sat_229、Sat_317、Satt335、Satt160、Satt516、Sat_309进行检测,抗病毒资源筛选的准确率分别达到68.9%、74.3%、71.1%、69.8%、77.4%和68.2%。利用与种粒斑驳抗性相关的SSR标记Sat_297、Sat_229、Sat_317、Satt335、Set_188、Satt160、Satt516、Sat_133进行检测,Sat_317标记准确率达79.1%,标记Sat_229、Satt335、Satt516和Sat_133抗病毒资源筛选的准确率均达70%以上,可以用作抗病毒分子辅助育种的选择标记。  相似文献   

11.
Hypothetical clinical cases were used to investigate surgical decision-making in relation to surgical rates across Ontario. Six procedures were studied (cholecystectomy, colectomy, inguinal herniorrhaphy, hysterectomy, cesarean section and tonsillectomy-adenoidectomy), and substantial differences of opinion regarding the choice of surgical or nonsurgical treatment were recorded. The decision to operate, however, was not made more frequently in Ontario counties with high operative rates, and none of the demographic variables studied were correlated with the decision to operate. Other variables that might have affected operative rates were not taken into account. There were also differences of opinion in referral decisions, but generally internists and pediatricians were less likely to refer the hypothetical cases to surgeons than were family physicians.  相似文献   

12.
13.
A total of 361 Escherichia coli O157 isolates, recovered from humans, cattle, swine, and food during the years 1985 to 2000, were examined to better understand the prevalence of antimicrobial resistance among these organisms. Based on broth microdilution results, 220 (61%) of the isolates were susceptible to all 13 antimicrobials tested. Ninety-nine (27%) of the isolates, however, were resistant to tetracycline, 93 (26%) were resistant to sulfamethoxazole, 61 (17%) were resistant to cephalothin, and 48 (13%) were resistant to ampicillin. Highest frequencies of resistance occurred among swine isolates (n = 70), where 52 (74%) were resistant to sulfamethoxazole, 50 (71%) were resistant to tetracycline, 38 (54%) were resistant to cephalothin, and 17 (24%) were resistant to ampicillin. Based on the presence of Shiga toxin genes as determined by PCR, 210 (58%) of the isolates were identified as Shiga toxin-producing E. coli (STEC). Among these, resistance was generally low, yet 21 (10%) were resistant to sulfamethoxazole and 19 (9%) were resistant to tetracycline. Based on latex agglutination, 189 (52%) of the isolates were identified as E. coli O157:H7, among which 19 (10%) were resistant to sulfamethoxazole and 16 (8%) were resistant to tetracycline. The data suggest that selection pressure imposed by the use of tetracycline derivatives, sulfa drugs, cephalosporins, and penicillins, whether therapeutically in human and veterinary medicine or as prophylaxis in the animal production environment, is a key driving force in the selection of antimicrobial resistance in STEC and non-STEC O157.  相似文献   

14.
This study was designed to determine conception rates in dairy cows after timed-insemination and simultaneous treatment with gonadotrophin releasing hormone (GnRH) and/or prostaglandin F2 alpha (PGF2alpha). A total of 2352 cows was randomly assigned to six groups. Cows in Groups 1 to 5 were palpated per rectum to determine the presence of a corpus luteum (CL) on the ovary, and blood samples were obtained for the determination of plasma progesterone (P4) concentrations. Cows with a CL and P4 concentrations >1 ng/ml were treated (Day 0) with PGF2alpha (25 mg, i.m.) and were observed for estrus. Cows in estrus prior to 72 hours after treatment (Group 5, n = 106) were bred, but were not treated. Cows not observed in estrus by 72 hours were divided into four remaining groups, were bred between 72 and 80 hours and were assigned as follows: Cows in Group 1 (n = 203) were not treated; Cows in Group 2 (n = 200) were treated with GnRH (100 ug, i.m.); Cows in Group 3 (n = 201) were treated with PGF2alpha (25 mg, i.m.); and cows in Group 4 (n = 202) were treated with both GnRH and PGF2alpha. Cows in Group 6 (n = 1440) were not treated with PGF2alpha on Day 0 and were estrual cows that were bred on days when cows in Groups 1 to 5 were time-inseminated. The percentage of cows in all groups pregnant at 45 to 50 days after one insemination was compared using analysis of variance (P<0.05). The conception rate of cows in Group 2 was significantly higher than that of cows in Groups 1 to 4. There was a significant group-by-season interaction. Cows treated with GnRH during the spring had a higher conception rate than at other times of the year. Conception rates of cows in Groups 1 to 4 that were inseminated during the summer were low and not significantly different from each other. Conception rates of cows in Groups 5 and 6 inseminated during the summer were not significantly different from each other, but were significantly higher than that of cows in Groups 1 to 4 that were inseminated during the summer.  相似文献   

15.
Staphylococcus aureus FDA 209P cells when suspended in 24% (w/v) NaCl were rendered osmotically fragile by exposure to lysostaphin for time intervals ranging from 2 to 60 min. Such cells were analyzed chemically and serologically for evidence of residual cell wall material, were plated in hypertonic sucrose medium to determine revertibility to normal, and were subjected to manometric studies to determine metabolic capabilities. Most of the cells (95%) which were exposed to lysostaphin (0.5 or 1.0 unit/ml) for 2 min, although osmotically fragile, retained their cell wall hexosamine and were capable of reverting to osmotically normal cells when plated in hypertonic medium. Cells exposed to lysostaphin for 5 and 10 min also retained much of their cell wall hexosamine, but lost their ability to revert to normal staphylococci. Cells exposed to lysostaphin for 2 to 10 min continued to react with staphylococcus anti-k antiserum. Complete removal of cell wall hexosamine was attained only after exposure to lysostaphin for 20 min or more; these cells failed to react with k antiserum. Lysostaphin-induced L-type colonies were extremely rare in our experiments, even if incubation times and media were optimal for their detection. Lysostaphin-induced staphylococcal protoplasts were as active metabolically in manometric studies as were untreated staphylococci.  相似文献   

16.
To catalog polypeptides that were specific to developing hearts, we separated 35S-methionine-labeled 9.5 day mouse embryos into cardiac and noncardiac (carcass) components. Two-dimensional gels were then used to analyze the polypeptides synthesized in these two fractions. As a result, we were able to distinguish polypeptides that were specific to or increased in the heart as well as those polypeptides that were specific to or increased in the embryo minus the dissected heart. Using this analysis, there were two polypeptides that were cardiac-specific and 17 that were expressed at increased levels by at least twofold in the heart. The cardiac-specific polypeptides may be used in further studies to identify early cardiac tissue. Conversely, there were 26 polypeptides unique to noncardiac structures and an additional 15 that were increased in the carcass more than twofold relative to the heart. The noncardiac-specific polypeptides may be used to define contamination of putative cardiac tissue with noncardiac material. Two of the polypeptides expressed more abundantly in the carcass appeared to correspond to known proteins in the mouse fibroblast database, cyclin and tropomyosin 4. Thus the heart at 9.5 days of murine development can be distinguished readily from the remainder of the embryonic mouse both macroscopically and on two-dimensional gels.  相似文献   

17.
Laboratory-reared Lymnaea catascopium snails (1–269 days old) were exposed individually to different numbers of Schistosomatium douthitti miracidia. Increasing the exposure dosage from 3 to 10 miracidia generally increased infection rates, in some age classes up to 100%. Successful re-exposure of snails not infected after a primary exposure was possible. Neonatal snails were least likely to become infected, primarily because miracidia were not attracted to them. Snails 12–55 days old were most susceptible to infection. Miracidia were readily attracted to these snails, and many were ingested and subsequently penetrated the host esophageal wall. Miracidial penetration of external snail surfaces was rare. Susceptibility of older snails (65–269 days) progressively declined with age. Many miracidia were entangled and immobilized in mucus produced by these snails, and fewer were ingested. No conspicuous host cellular responses to mother sporocysts were observed in any of the snails sectioned. A comparison of susceptibility of deliberately stunted snails and comparably aged controls of normal size indicated that the former were more susceptible.  相似文献   

18.
长江流域棉区棉花新品种抗病虫性研究   总被引:1,自引:1,他引:0  
2003年,对长江流域棉区15份新材料进行了抗红铃虫鉴定,结果有8份材料高抗红铃虫,占鉴定材料的53.33%;4份材料抗红铃虫,占26.67%;3份材料中抗红铃虫,占20.00%.对55份新材料进行抗枯萎病鉴定,结果有27份材料抗枯萎病,占鉴定材料的49.09%;26份材料耐枯萎病,占47.27%;2份感枯萎病,占3.64%.对59份材料进行抗黄萎病鉴定,结果有8份材料抗黄萎病,占鉴定材料的13.56%;43份材料耐黄萎病,占72.88%;8份材料感黄萎病,占13.56%.  相似文献   

19.
In 2002, a field survey was initiated on French apiaries to monitor weakness of honey bee, Apis mellifera L., colonies. Apiaries were evenly distributed in five sites located on continental France. Five colonies were randomly selected in each apiary, leading to a total of 125 studied honey bee colonies. For 3 yr (starting in autumn 2002), colonies were visited four times per year: after winter, before summer, during summer, and before winter. Pollen loads from traps were collected at each visit. Multiresidue analyses were performed in pollen to search residues of 36 different molecules. Specific analyses were conducted to search fipronil and metabolites and also imidacloprid and metabolites. Residues of 19 searched compounds were found in samples. Contamination by pesticides ranged from 50 to 0%. Coumaphos and tau-fluvalinate residues were the most concentrated of all residues (mean concentrations were 925.0 and 487.2 microg/kg, respectively). Fipronil and metabolite contents were superior to the limit of detection in 16 samples. Residues of fipronil were found in 10 samples. Nine samples contained the sulfone compound, and three samples contained the desulfinyl compound. Residues of imidacloprid and 6-chloronicotinic acid were found in 69% of samples. Imidacloprid contents were quantified in 11 samples with values ranging from 1.1 to 5.7 microg/kg. 6-Chloronicotinic acid content was superior to the limit of quantification in 28 samples with values ranging from 0.6 to 9.3 microg/kg. Statistical tests showed no difference between places of sampling with the exception of fipronil. Possible origins of these contaminations, concentration and toxicity of pesticides, and the possible consequences for bees are discussed.  相似文献   

20.
目的了解人工饲养树[鼠句]肠道菌群感染情况及其各种细菌对药物的敏感性。方法通过肠道细菌采样、培养、分离和菌落生长特性观察,并经革兰氏染色、氧化酶试验、触酶试验、生化编码鉴定管试验和9种药敏试验分析,初步鉴定了107例人工饲养树[鼠句]肠道感染细菌的种类和这些细菌对药物的敏感程度。结果本次细菌培养共从树[鼠句]肠道中培养分离出5株细菌,其中革兰氏阳性菌2株,革兰氏阴性菌3株,以大肠杆菌和葡萄球菌最为多见。同时确定了菌株的药敏情况为:(1)大肠杆菌对头孢类药头孢哌酮最为敏感,对药物磺胺甲嚼唑/甲氧苄定、氧氟沙星、左氧氟沙星、呋喃妥因、诺氟沙星、氨苄西林高敏;(2)沙门氏菌对阿米卡星最为敏感,对药物头孢哌酮青霉素G高敏;(3)链球菌对试验药物氨苄西林、头孢哌酮、呋喃妥因显示为中敏;(4)葡萄球菌对头孢类药头孢哌酮、磺胺类磺胺甲晤唑/甲氧苄定、沙星类诺氟沙星、左氧氟沙星、氧氟沙星、呋喃妥因和氨苄西林最为敏感,对其它药物均为中敏;(5)假单胞菌对药物左氧氟沙星最为敏感,对大多数药物都显示高敏。结论大肠杆菌和葡萄球菌可能是树鼢肠道中正常寄生的主要菌群,同时其它菌群也有寄生。用药敏实验筛选出的药物可为临床用药和动物的生物净化提供指导依据。  相似文献   

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