宁夏地区腹泻犊牛产超广谱β-内酰胺酶大肠埃希氏菌的药敏试验及脉冲场凝胶电泳分型

为了解宁夏地区规模化牛场犊牛腹泻源产超广谱β-内酰胺酶(ESBLs)大肠埃希氏菌耐药和遗传变异情况，对分离得到的17株产ESBLs大肠埃希氏菌，采用K-B纸片法进行药物敏感性试验，采用脉冲场凝胶电泳进行分型研究。结果显示，17株分离株对试验药物多数呈耐药状态，对头孢拉定、四环素、阿莫西林3种药物完全耐药，其他药物的耐药性为70.24%～94.12%,只对阿米卡星、诺氟沙星敏感性较高。分离菌株可分为17个PFGE型，菌株间的相似度为67.5%～85.7%,无优势带型。宁夏地区犊牛腹泻源产ESBLs大肠埃希氏菌耐药性严重，遗传差异较大，但不同菌株存在着不同程度的亲缘关系。     

鸡源大肠杆菌的分离鉴定及药敏分析

为分析鸡源大肠杆菌的分子流行特点及其耐药情况,研究采用鸡源大肠杆菌分离培养、形态观察、微生物学鉴定、致病性分型鉴定、多重PCR进化分群鉴定(针对arpA、chuA、TspE4.C2和YjaA基因)、药敏分析等.结果 表明:分离出的菌株均为大肠埃希氏菌,属于肠产毒性大肠埃希氏菌(ETEC)、肠侵袭性大肠埃希氏菌(EIEC...     

东北地区鸡源大肠杆菌的毒力基因检测及PFGE分型研究

为了研究东北地区健康鸡源大肠杆菌毒力基因的携带分布以及PFGE分子分型情况,试验采用PCR技术对413株鸡源大肠杆菌的4种毒力基因进行检测,并运用XbaⅠ酶进行酶切后完成PFGE分析,利用软件分析菌株间的相关性和遗传关系。结果表明,在检测的413株菌株中,fimH毒力基因携带率为77.72%,iucD毒力基因的检出率为56.42%,强致病性毒力岛(HPI)的标志基因fyuA和irp2毒力基因携带率分别为44.07%和43.83%;29株大肠杆菌呈现出28种不同的PFGE型,每一株菌被XbaⅠ消化为14~20条带,菌株相似度为30%~100%;多数菌株携带毒力基因,且毒力基因的类型较为复杂,PFGE分型结果具有多样性和差异性。提示应加强鸡源大肠杆菌毒力基因的检测以及分子分型研究,为大肠杆菌病等防控提供参考。     

我国不同地区鸡源致病性大肠杆菌分离株的PFGE分子分型

为了解我国鸡源致病性大肠杆菌的分子流行病学状况,利用PFGE分子分型方法,对2017年分离自山东、吉林、新疆、西藏等7个代表性区域的130株大肠杆菌分离株进行了分子分型研究。结果显示:130株大肠杆菌共分为105个带型,其中33株菌株的图谱相似度在90%以上;不同来源菌株的PFGE带型差别较明显,即使是相同来源菌株,PFGE带型差异同样显著,显示了分离株菌株的遗传多样性。本研究为指导我国鸡群大肠杆菌病防控以及鸡源致病性大肠杆菌引发疾病或食品安全突发事件的追踪溯源提供了依据。     

沈阳某鸡场大肠埃希菌的分离鉴定及药敏试验

对沈阳市某肉鸡养殖场的85例病死鸡进行大肠埃希菌的分离鉴定及药物敏感性试验,结果分离到大肠埃希菌62株,分离率为72.9%,分离菌株对头孢氨苄全部耐药,对其余抗菌药物的耐药率在0~88.7%之间,多重耐药情况普遍。     

水禽源沙门菌的分离鉴定与PFGE分子分型

为了明确目前广东省水禽源沙门菌的优势血清型及其分子流行病学动态,采用细菌分离纯化、生化特性鉴定和PCR扩增从316份样品中分离鉴定出188株水禽源沙门菌;采用玻片凝集法将分离株分为4(B、D、C1、E1)个群别8种血清型;采用脉冲场凝胶电泳(PFGE)分型法对分离株进行分子分型,得到PFGE-XbaⅠ带型62种,菌株间相似度为54.1%~100.0%,分为A^I共9个聚类簇与11个单一基因型。结果表明,广东水禽源沙门菌优势血清型为鼠伤寒沙门菌,PFGE-XbaⅠ带型具多样化,其中11种PFGE-XbaⅠ带型在区域和年份小范围集中流行,32种带型跨区域与跨时间交叉分布呈散在"流行暴发",不同血清型分离株的PFGE-XbaⅠ带型差异较大,相同血清型的分离株PFGE-XbaⅠ带型一般具有相同图谱型或聚类在一起。本研究采用PFGE法进行分子分型分析具有流行病学意义,并探明了本地沙门菌分离株血清型与分子分型的关系。     

猪源分离大肠埃希菌产ESBLs的基因型及耐药性分析

为了解上海地区规模化猪场分离的大肠埃希菌产超广谱β-内酰胺酶（ESBLs）的分离率、耐药性和基因型,收集2010年9月-2011年3月从上海地区10个规模化养猪场分离的296株大肠埃希菌,采用微量肉汤稀释法进行药敏试验以及PCR技术分别检测TEM、CTX-M、OXA和SHV基因。在296株大肠埃希菌中,52株大肠埃希菌产ESBLs,产酶率为17．6％。在52株ESBLs菌株中,46株为TEM型,占88．5％;15株为CTX—M型,占28．8％;11株为同时携带TEM型和CTX—M型,占21．2％。大肠埃希菌产ESBLs株对10种常用抗菌药物的耐药性较为严重,而且存在多重耐药;上海地区猪源大肠埃希菌产ESBLs株流行的主要基因型为TEM型和CTX—M型。     

鸡源大肠埃希氏菌流行病学调查及耐药性分析

为了解广东韶关地区鸡源大肠埃希氏菌的流行病学及其耐药性特点,本研究通过2022年对采集自广东韶关地区41个规模养鸡场和28个土鸡散养场的鸡喉头、肛门粪便、病死鸡的肝脏、心血、脾、肠道内容物共737份样品进行细菌分离纯化、病原菌的生化鉴定和药敏试验,研究广东韶关地区鸡源大肠埃希氏菌的流行病学及其耐药性特点。结果显示,541份样品分离到大肠埃希氏菌,检出率73.41%,总体泄殖腔大肠埃希氏菌检出率87.78%,咽喉部大肠埃希氏菌检出率58.24%,死鸡病料大肠埃希氏菌检出率78.38%,规模场大肠埃希氏菌检出率为73.72%,散养场大肠埃希氏菌检出率为73.01%。分离菌株普遍对阿奇霉素、头孢噻肟、阿米卡星、氧氟沙星、诺氟沙星、环丙沙星、恩诺沙星敏感,对青霉素、氨苄西林、链霉素、卡那霉素、四环素、阿莫西林、氟苯尼考、泰乐菌素、林可霉素、克林霉素耐药,多重耐药比高达79.71%。规模场分离菌多重耐药比为97.56%,散养场多重耐药比为53.57%。本研究为广东韶关地区鸡源大肠杆菌病的防控提供了参考。     

宠物源大肠埃希菌的分离鉴定和耐药性研究

为调查长春地区宠物源大肠埃希菌耐药流行情况,从2家宠物医院采集135份宠物肛拭子样品,分离和鉴定大肠埃希菌并进行多重PCR分群。测定大肠埃希菌分离株对19种抗菌药物的耐药性,并鉴定超广谱β-内酰胺酶(ESBLs)表型。共分离鉴定获得95株宠物源大肠埃希菌,它们对氨苄西林和哌拉西林的耐药率最高(78.9%和76.8%);其次是四环素(61.6%);对头孢唑林、头孢噻肟、头孢吡肟、庆大霉素、复方新诺明、环丙沙星和左氧氟沙星的耐药率均超过了50%;所有分离株均对亚胺培南和美罗培南敏感。其中15个分离株对受试的抗菌药物全部敏感(15.8%),63株呈多重耐药表型(66.3%)。ESBLs型菌株占53.7%。本研究探明了长春地区宠物源大肠埃希菌的耐药流行情况,对宠物临床上用药具有指导价值。     

青岛地区鸡源大肠埃希氏菌的分离鉴定及耐药性分析

为调查青岛地区鸡源大肠埃希氏菌的流行性及耐药情况,从青岛部分规模化养殖场随机采集185份鸡泄殖腔拭子,通过选择性培养基和16S rRNA进行大肠埃希氏菌分离纯化和菌属鉴定,采用琼脂稀释法对11种抗菌药物进行药敏试验并应用PCR检测碳青霉烯类、β-内酰胺类、黏菌素类和四环素类耐药基因。结果显示共分离到173株大肠埃希氏菌,分离率为93.50%。药敏试验结果表明,分离菌株对阿莫西林、头孢氨苄、四环素等8种抗菌药物耐药率为61.27%～100.00%,对美罗培南、亚胺培南、替加环素耐药率为0.58%～30.06%。分离菌株均表现为多重耐药(3耐～10耐),以7耐～8耐为主。耐药基因检测显示,bla_CTX-M和tetA检出率为95.95%和90.75%,其他耐药基因的检出率为3.47%～37.90%。结果表明,山东省青岛地区鸡源大肠埃希氏菌耐药率较高,多重耐药情况严重,给食品安全及公共健康造成了潜在威胁。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -