原料乳和临床乳房炎金黄色葡萄球菌毒力基因检测及药敏分析

对临床乳房炎（57株）和原料乳（44株）金黄色葡萄球菌菌株,用PCR方法检测mecA基因、PVL基因、ETs基因、SEs基因和TSST-1基因;采用CLSI指导说明执行琼脂稀释法药敏性试验。结果显示原料乳菌株中,84.09%携带有毒素基因,其中PVL的检出率为84.09%,肠毒素的检出率为52.27%,主要流行的肠毒素基因为sea（56.82%）,均未检测到携带mecA、ETs、TSST-1、sei和sej基因的菌株;同时得到10种毒素基因型,其主要流行的毒素基因型为PVL＋sea（29.55%）和PVL（27.27%）。临床菌株中,78.95%携带有毒素基因,其中PVL的检出率为28.07%,肠毒素的检出率为77.19%,主要流行的肠毒素基因为sea（47.37%）,没有检测到携带ETs、TSST-1和seh基因菌株;同时得到25种毒素基因型,其主要流行的毒素基因型为sea（19.30%）,其次是seb（7.02%）,sea＋sed＋sej（3.51%）和PVL＋sea＋seb＋sec＋seg＋sei（3.51%）。6株（10.53%）携带有mecA基因菌株均含有较多毒素基因。原料乳分离株对甲氧苄啶和头孢西丁的耐药率较高,分别为100%和86.36%,其次对氯霉素、红霉素、苯唑西林、头孢哌酮和庆大霉素的耐药率分别为11.36%、4.55%、2.27%、2.27%和6.82%,所有原料乳菌株均对环丙沙星敏感,同时得到8种耐药谱,多重耐药率达22%;临床乳房炎菌株对红霉素和甲氧苄啶的耐药率较高,分别为100%和71.93%,其次对氯霉素、庆大霉素、环丙沙星、头孢西丁和苯唑西林的耐药率分别为28.07%、26.07%、24.56%、19.30%和7.02%,临床乳房炎菌株对头孢哌酮和四环素的敏感率为100%,同时得到13种耐药谱,多重耐药率达77.19%。所有原料乳和临床乳房炎菌株均对万古霉素和阿米卡星敏感。临床乳房炎菌株携带的毒素基因和多重耐药率比原料奶菌株高,同时在临床乳房炎乳中检测到MRSA菌株,提示我们应加强乳及其乳制品的管理,并对奶牛乳房炎加以重视。     

雏鸡葡萄球菌病的调查及其防治

于2012年对新镇十一个典型发病鸡群存栏的三万多只鸡进行了较为系统的调查.通过调查,基本上摸清了本病在新镇发生、发展规律、病原、传播途径以及发病有很大关系的外界各种因素,为防止本病在新镇的广泛流行,为我们提供了行之有效的综合防治方法.     

牛源金黄色葡萄球菌的分离鉴定及药敏试验

研究金黄色葡萄球菌的耐药性状况,指导兽医临床用药。采用高盐甘露醇进行纯化培养,梅里埃全自动微生物分析系统对葡萄球菌鉴定板进行鉴定,纸片扩散法进行药敏实验。从阳性乳房炎样品中分离纯化并鉴定了样品中的金黄色葡萄球菌2株,测定了其耐药性。在选取的5种药物中,青霉素对分离病原菌的抗菌活性较高,其次是恩诺沙星和庆大霉素,而链霉素和磺胺嘧啶钠对分离病菌的抗菌活性较低。     

动物源性耐甲氧西林葡萄球菌耐药表型及基因型鉴定

通过耐药表型及基因型检测对临床分离的41株葡萄球菌进行了鉴定，鉴定出耐甲氧西林金黄色葡萄球菌（MRSA）16株，耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)4株。耐甲氧西林葡萄球菌（MRS）阳性率达到48.8%，这提示兽医临床必须提高对MRS的重视，并为临床鉴定MRS提供了可借鉴的方法。     

PCR扩增Nuc基因检测奶牛乳腺炎致病性金黄色葡萄球菌

为建立奶牛乳腺炎金黄色葡萄球菌致病菌株的检测方法,依据金黄色葡萄球菌耐热核酸酶Nuc基因序列,设计合成特异性引物,通过聚合酶链式反应扩增Nuc基因,并将扩增基因克隆入T载体,进行序列测定,对所分离的奶牛乳腺炎病原菌进行鉴定.结果显示:金黄色葡萄球菌扩增出特异性条带,大小为694bp;其他菌株未出现条带.敏感性检测的最低浓度为1.25×103 cfu/mL.本试验所建立的方法具有特异性强、敏感度高的特点.     

仔猪渗出性皮炎灭活疫苗的研制与应用

从发病猪场采集仔猪渗出性皮炎病料,分离培养,鉴定出病菌为猪葡萄球菌,制备成铝胶灭活疫苗,免疫于产前1个月母猪2次,免疫效果明显。     

乳源耐甲氧西林葡萄球菌的耐药性、 产毒性与生物膜形成能力检测

从安徽省合肥地区奶牛隐性乳房炎生乳中分离鉴定24株耐甲氧西林金黄色葡萄球菌(MRSA)。采用E-test方法测定12种抗菌药物对乳源MRSA合肥分离株的最小抑菌浓度,微量板半定量法测定乳源MRSA合肥分离株形成生物膜的能力,PCR方法检测这些分离株携带耐药基因、毒力基因和生物膜形成相关基因的情况。结果显示受试MRSA分离株对苯唑西林、克林霉素、甲氧苄胺嘧啶、红霉素、利福平、头孢噻肟、庆大霉素、环丙沙星、四霉素、丁胺卡那、替考拉宁和万古霉素的耐药率依次为100%、75%、54.2%、50%、45.8%、45.8%、33.3%、29.2%、25%、20.8%、4.2%和0%,且83.3%分离株呈现多重耐药;受试MRSA分离株携带耐药基因mec A、blatem-1、aac(6’)/aph(2")、Erm B、tet M和qac A基因的检出率分别为100%、54.2%、70.8%、33.3%、41.7%和50%,而毒力基因Clf A、Fn BPA、SEA、PVL、TSST、Hla、Ca L和Nuc的携带率分别为33.3%、83.3%、79.2%、37.5%、58.3%、87.5%、100%和100%;受试MRSA分离株中生物膜形成能力强、中等、弱以及不能形成生物膜的细菌分别占37.5%(9/24)、12.5%(3/24)、25%(6/24)和25%(6/24),生物膜形成相关基因ica A、ica D、agr、Sig B和Sar A基因的检出率分别为50%、50%、50%、91.7%和83.3%。结果表明,乳源MRSA合肥分离株均为产毒性和多重耐药性MRSA,且75%分离株具有生物膜形成能力。     

In vitro efficacy and pharmacodynamic profiles of four polyether ionophores against methicillin-resistant Staphylococcus spp.

The objective of this study was to determine the minimum inhibitory concentrations (MICs) and pharmacodynamic profiles of four ionophores (lasalocid, monensin, narasin and salinomycin) against staphylococcal isolates from clinical cases of human and veterinary staphylococcal infections, and to determine the effect of methicillin resistance on the antimicrobial activity of ionophores. Broth microdilution MIC testing was used to determine antimicrobial activity against 156 staphylococcal isolates of human and veterinary origin. Pharmacodynamic profiles were examined using time-kill kinetics profiles against an ATCC type strain of Staphylococcus aureus and a clinical isolate of methicillin-resistant Staphylococcus pseudintermedius. All tests were performed in accordance with CLSI guidelines. All four ionophores demonstrated antimicrobial activity against methicillin-resistant staphylococci at concentrations similar to those observed for methicillin-susceptible isolates of the same species. Testing of human and veterinary MRSA isolates also showed that MIC values were not influenced by the host origin of the isolates. Pharmacodynamic profiles were similar for both isolates tested across all four ionophores, with similar reductions in viable cell counts being observed over an 18- to 24-hr period. Lasalocid, monensin, narasin and salinomycin all demonstrated antimicrobial activity against staphylococcal isolates of human and veterinary origins, with activity being unaffected by methicillin resistance status, although some Staphylococcus species-specific effects were observed that require further investigation.     

Determination of staphylococcal exotoxins, SCCmec types, and genetic relatedness of Staphylococcus intermedius group isolates from veterinary staff, companion animals, and hospital environments in Korea

The Staphylococcus (S.) intermedius group (SIG) has been a main research subject in recent years. S. pseudintermedius causes pyoderma and otitis in companion animals as well as foodborne diseases. To prevent SIG-associated infection and disease outbreaks, identification of both staphylococcal exotoxins and staphylococcal cassette chromosome mec (SCCmec) types among SIG isolates may be helpful. In this study, it was found that a single isolate (one out of 178 SIG isolates examined) harbored the canine enterotoxin SEC gene. However, the S. intermedius exfoliative toxin gene was found in 166 SIG isolates although the S. aureus-derived exfoliative toxin genes, such as eta, etb and etd, were not detected. SCCmec typing resulted in classifying one isolate as SCCmec type IV, 41 isolates as type V (including three S. intermedius isolates), and 10 isolates as non-classifiable. Genetic relatedness of all S. pseudintermedius isolates recovered from veterinary staff, companion animals, and hospital environments was determined by pulsed-field gel electrophoresis. Strains having the same band patterns were detected in S. pseudintermedius isolates collected at 13 and 18 months, suggesting possible colonization and/or expansion of a specific S. pseudintermedius strain in a veterinary hospital.     

獭兔金黄色葡萄球菌和波氏杆菌混合感染的诊治

四川某獭兔养殖场2001年2月～3月底爆发一种以呼吸道症状为主的疾病,表现为流鼻涕、鼻塞、喷嚏、咳嗽,严重者流脓性鼻液,采食量长期低于正常水平,但没有死亡,发病率85%～90%,兔消瘦,被毛粗糙.以病兔鼻液、气管黏液、肺组织为病料分离细菌,经过对分离细菌镜下形态、培养特性和生化试验,确认为葡萄球菌和波氏杆菌的混合感染,经药敏实验筛选敏感药物氧氟沙星、红霉素配合治疗,取得较好疗效.