Drug Susceptibility Test of Volatile Oil of Artemisiaargyi to Avian Pathogenic Escherichia coli

The volatile oil of Artemisia argyi was extracted by ultrasonic assisted extraction, and the extraction rate of volatile oil was 0.68%. Thevolatile oil of A. argyi was emulsified with 1% Tween-80, and drug susceptibility test was conducted with avian Escherichia coli. The results showedthat the volatile oil of A. argyi had antibacterial effect against avian E. coli, and the minimal inhibitory concentration was 50 mg/mL. Taking sixcommon antibiotics as the control, drug susceptibility test was conducted with volatile oil of A. argyi. The results showed that 10 strains of E. coliwere sensitive to the volatile oil of A. argyi, three of which had different degrees of resistance and one had the tendency of resistance.

Isolation, Identification and Drug Sensitivity Test of a Pathogenic Escherichia coli Strain from Minks with Diarrhea

[Objectives] The study aimed to identify the pathogen that causes diarrhea in minks. [Methods] Liver tissues were aseptically collected from dead minks with diarrhea. By bacterial isolation and culture,morphological observation,biochemical test and pathogenicity test,the isolated strain was identified as pathogenic E. coli. [Results]The pathogen causing diarrhea in minks was confirmed as a pathogenic E. coli strain. Drug sensitivity test indicated that the isolated pathogenic E. coli strain was highly sensitive to ceftazidime,cefotaxime,enrofloxacin,florfenicol and cephradine,moderately sensitive to ampicillin,ciprofloxacin,amikacin,doxycycline,lincomycin and gentamycin,and resistant to amoxycillin,neomycin,spectinomycin,polymyxin and penicillin. [Conclusions] This study provided reference for the prevention and control of abortion in female minks in Qinhuangdao region.

Isolation, Identification and Drug Susceptibility Test of a Strain of Escherichia coli Causing Fox Pneumonia

[Objective] The paper was to determine the pathogen causing fox pneumonia in a breeding factory in Changli County.[Method]Through autopsy, a dominant strain was isolated from the lung of dead foxes, which was then performed Gram staining, 16 S rRNA sequence analysis and biochemical identification.[Result] The strain was negative in Gram staining, and was identified as E. coli through 16 S rRNA sequence analysis and biochemical identification. Drug susceptibility test was conducted using 15 kinds of drug susceptibility papers. The E. coli was sensitive to florfenicol, enrofloxacin, ceftriaxone, norfloxacin;intermediately sensitive to amikacin, gentamicin;and strongly resistant to penicillin, ampicillin,cefradine, sulfamethoxazole, lincomycin, streptomycin and amoxicillin.[Conclusion] It is difficult to treat E. coli causing fox pneumonia with traditional antibiotics clinically.

Field Assessment of the Level of Protection Conferred by a Newly Prepared Combined Inactivated Vaccine against E. coli and P. multocida in Rabbit in Egypt

Pasteurellosis is the most prevalent, extremely contagious bacterial disease among domestic rabbits and is considered the leading cause of deaths in rabbits, resulting in enormous economic losses to the rabbit industry. Screening for bacterial agents causing mortalities in rabbits revealed the presence of Enterobacteriacae species in approximately 42% of studied cases, with E. coli the most commonly isolated organism. The present study was designed to evaluate the immune response of rabbits vaccinated with a locally prepared, combined inactivated vaccine of Pasteurella multocida and E. coli, adjuvanated with Montanide ISA70. A total of 370 rabbits, aged 2 - 3 weeks, were divided into four groups: (G1) vaccinated with a polyvalent P. multocida vaccine, (G2) vaccinated with a polyvalent E. coli vaccine, (G3) vaccinated with a combined inactivated Montanide ISA70 vaccine of P. multocida and E. coli, and (G4) kept as a non-vaccinated control group. All rabbits received two doses of 0.5 ml of the prepared vaccines, administered one month apart, and were then challenged with virulent strains of P. multocida and E. coli three weeks after the second vaccination. The prepared vaccines were evaluated by determining humoral immunity using indirect haemagglutination (IHA) test and ELISA. The potency of the vaccines was assessed through challenge and determination of LD50. Experimental findings on the prepared polyvalent combined inactivated P. multocida and E. coli vaccine indicated that it is a potent vaccine, producing the highest antibody titers and a 90% protection rate against challenges with virulent strains of P. multocida type A, D2, and E. coli types O157, O151 and O125. Thus, this vaccine is promising in addressing both P. multocida and E. coli problems in rabbits, farms, providing significant protection, and we recommend its commercial production to help rabbit producers control these two major bacterial infections.

一株致多发性浆膜炎猪源肠外E.coli的分离与鉴定

无菌采集多发性浆膜炎病猪的心血、肝脏,进行细菌分离培养,并对分离菌株进行染色镜检、生化试验、PCR鉴定、小鼠致病性试验和药敏试验。结果显示,分离菌株为肠外致病性大肠杆菌;分离菌株对庆大霉素、恩诺沙星、强力霉素、氨苄西林、磺胺类药物、头孢噻肟等均耐药,对阿米卡星、多粘菌素、美罗培南、亚胺培南敏感。本研究为致多发性浆膜炎的猪大肠杆菌病的诊断与防治提供了参考依据。

河南省76株E.Coli O_(157):H_7菌株药物敏感性研究

目的探讨我省E.ColiO157:H7菌株的药物敏感性特点。方法美国疾病预防控制中心和WHO非洲区合作编写的“痢疾和霍乱流行的实验室诊断方法”中介绍的琼脂平板扩散法。结果76株E.ColiO157:H7菌株对庆大霉素、头抱噻甲羧肟、多粘菌素B、氯霉素、氟哌酸、阿莫西林六种抗生素的耐药率均<5%。有毒力菌株与无毒力菌株对庆大霉素、强力霉素、复方新诺明、氯霉素、四环素的耐药率差别有统计学意义,无毒力菌株的耐药率高于有毒力菌株。结论实验结果显示临床治疗可参考使用头抱类、喹诺酮类和氯霉素类抗生素。

秦皇岛地区貂源大肠杆菌(E. coli)的分离鉴定及药敏试验分析

为了确定秦皇岛地区貂源大肠杆菌(E. coli)流行情况及耐药性。本试验从秦皇岛地区不同水貂养殖场采集腹泻水貂的肠内容物及粪便57份,通过细菌的分离培养,形态学观察、生化鉴定等方法,分离鉴定出42株E.coli。致病性试验表明,34株为致病性E.coli。药敏试验结果表明,该菌仅对头孢克肟、头孢曲松、氟苯尼考等4种药物高度敏感;该菌具有很强的耐药性,耐药率达到40.4%～100%;该菌存在多重耐药现象,最高耐15种药物,且均耐8种药物以上。本研究为该地区水貂大肠杆菌病防治提供研究基础。

大肠埃希氏菌(Escherichia coli)用于食品检验培养基质量控制的研究

通过研究测试菌株大肠埃希氏菌(Escherichia coli)CICC 24176和CICC 24652在不同培养基上的生长特性,以评价其质控食品微生物学检验培养基的可行性。依据GB 4789.28—2013中定量、半定量及定性方法,ATCC 25922作为对照菌株,确认2株测试菌株在非选择性分离和计数固体培养基、选择性分离和计数固体培养基、选择性增菌培养基、选择性液体计数培养基和鉴定培养基上共6类58种培养基上的生长率、选择性及特异性。结果表明,菌株CICC 24176和CICC 24652在分离和计数固体培养基上生长率均>0.7,在选择性液体计数培养基上的生长情况良好,在选择性固体培养基和悬浮培养基上生长被有效抑制,在特异性培养基上均具有典型生化特征;菌株CICC 24176在除SC液体培养基外的8种选择性增菌培养基上被有效抑制,而CICC 24652在所有选择性增菌培养基上均被有效抑制;菌株CICC 24176在18种鉴定培养基上具有典型生化特征,而菌株CICC 24652在16种鉴定培养基上具有典型生化特征,SIM(hydrogen sulfide indole motility)动力培养基及缓冲动力硝酸盐培养基上动力呈阴性。综上,2株测试菌株可分别用于相应培养基微生物性能指标的质量评价。

Isolation and Identification of a Pathogenic E.coli Strain Causing Diarrhea in Foxes

[Objectives] The study aimed to identify the pathogenic E. coli strain that caused diarrhea in foxes and to analyze its drug sensitivity.[Methods] A pathogenic E. coli strain was isolated from dead foxes with diarrhea. By conventional bacterial isolation and culture, morphological observation, pathogenicity test and K-B disc method, the isolated strain was identified as pathogenic E. coli .[Results] The isolated pathogen was highly sensitive to ceftriaxone, cefotaxime, ciprofloxacin and lincomycin, moderately sensitive to enrofloxacin, neomycin, gentamycin, spectinomycin, florfenicol, amikacin and polymyxin, and resistant to ampicillin, amoxicillin and doxycycline.[Conclusions] This study provided reference for the prevention and control of diarrheal diseases in foxes in Qinhuangdao region.

Characterization of toxin from Verocytotoxigenic Ecscherichia coli(VTEC) strains isolated from neonatal calves in India

Objective:The present study has characterized dialyzed toxin from non-0157 VTEC E.coli isolates by vero cell toxicity assay and pathogenecity in mice model.Methods:Toxins from non-0157 verocytotoxic Escherichia coli isolated from neonatal calves were characterized.Dialyzed toxin from E.coli 026,0111 and 0103 serotypes were prepared and characterized by verocell toxicity assay and pathogenicity in mice model.E.coli 0157:H7 considered as positive control for this study.Results:Cytopathic effects in vero cell line first rounding of vero cells,followed by clumping of cells and finally disintegrated,blackened,shriveled cell line within 16 to 72 hrs.Phenotypic markers such as hind limb paralysis and reddening of tail were prominent in all the toxicated mice.Extensive histopathological study was conducted for multiple organ involvement.Conclusion: Several methods for toxin assay were developed based on biological,immunological and detection of virulence genes related to toxin production but each test has draw back.Therefore,it is likely that future effort will be focused on the development of assay,which is fast,reliable,specific and sensitive methods based on mice model.

Monitoring and Analysis on Multi Drug Resistance of Escherichia coli from Captive Population Amur Tiger

In order to investigate the multi drug resistance to Escherichia coli from captive population Amur tiger,E. coli strains were isolated from the fecal samples of tiger in Heilongjiang Amur Tiger Park in Harbin. The sensitivity of E. coli isolates to 14 antibiotics was determined by scrip diffusion method. The results indicated that all the isolates varied in drug resistance to different antibiotics; the isolates gave high resistance to ampicillin,with a drug fast rate of 100%; over80% of the isolates were resistant to tetracycline and Paediatric Compound Sulfamethoxazole Tablets(SMZ- TMP),and over 70% of the isolates were sensitive to aztreonam,amoxicillin /potassium clavulanate. Most of the isolates had high sensitive to aztreonam and amoxicillin / clavulanate acid.

Antimicrobial Susceptibility Profiles among <i>Escherichia coli</i>Strains Isolated from Athi River Water in Machakos County, Kenya

Antimicrobial use in agriculture, livestock and human health has increased over the years leading to the increase in antimicrobial resistance that can also find its way to the aquatic environment. Rivers can act as reservoirs of highly resistant strains and facilitate the dissemination of multidrug resistant (MDR) strains to animals and humans using water. A total of 318 water samples were collected from six different sampling points along Athi River and E. coli isolates were subjected to Kirby-Bauer diffusion method for antimicrobial susceptibility testing. The total mean coliform count of the sampled sites was 2.7 × 104 (cfu/mL). E. coli isolates were most resistant to ampicillin (63.8%) and most susceptible to gentamicin (99.4%). MDR strains (resistance to ≥3 classes of antibiotics) accounted for 65.4% of all the isolates. The site recorded to have human industrial and agricultural zone activities had strains that were significantly more resistant to ampicillin, cefoxitin, amoxicillin/clavulanic acid (P ≤ 0.05) than isolates from the section of the river traversing virgin land and land with minimum human activities. This study indicates that E. coli strains isolated from Athi River were highly MDR and most resistant to some antimicrobial classes (ampicillin and cefoxitin) which constitute a potential risk to human and animal health.

Isolation and Characterization of E. Coli O157 : H7 from Infected Newborn Calves in Northeast China

Escherichia coli O157 : H7 is a foodborne pathogen that poses a major threat to public health. Epidemiologic investigations have identified dairy cows, especially calves, are the principal reservoir of E. coli O157 : H7. In this study, based on the results, E. coli O157 : H7 was the main cause of E. coli disease outbreak in late October, 2015, and more than 90% of newborn calves died of serious diarrhea. Through further experiments, the drug sensitivity and resistance of the strain, the expression of the virulence gene and virulence pathogenicity were studied. E. coli O157 : H7 isolates were resistant to 12 antibiotics including penicillin, tetracycline and ampicillin, and were sensitive to eight antibiotics including cefoperazone, ceftazidime and amikacin. Resistance genes included tetB, strB, aadB, aphA, floR, TEM and virulence genes included stx1, eaeA and hlyA. Using specific pathogen free mice, the result showed that the isolate was pathogenic with a median lethal dose of 7.9×107 CFU · mL-1. This study described the pathogenesis and clinical manifestations of E. coli O157 : H7 infection. These results guided the use of antibiotics in prevent and control of bacterial infections in the future.

某医院近10年大肠埃希菌分离率和耐药率的变迁情况

目的总结近10年中国医科大学附属第一医院大肠埃希菌的分离率和耐药率,为临床抗感染经验治疗提供依据。方法数据来自2013年至2022年间从中国医科大学附属第一医院就诊患者中分离的大肠埃希菌,使用VITEK 2和VITEK MS进行菌种鉴定,使用VITEK2和KB法进行药物敏感性试验,采用WHONET 5.6软件进行分析。结果2013年至2022年共分离6845株菌株,其中80.5%来自住院患者,19.5%来自门诊和急诊患者。常见标本类型为尿液(57.8%)、血液(15.0%)、分泌物(9.2%)、引流液(8.1%)。大肠埃希菌超广谱β-内酰胺酶(ESBL)分离率为57.2%(54.3%~61.5%)。大肠埃希菌对碳青霉烯类抗菌药物的耐药率较低,仅为1.2%(0.2%~2.6%)。结论大肠埃希菌仍是临床感染的重要病原菌,对多种抗菌药物存在不同程度的耐药,且耐药率有上升趋势,临床医师应给予足够的关注。

Antibiogram of Extended-Spectrum <i>β</i>-Lactamase (ESBL) Producing <i>Escherichia coli</i>

Background: Extended-spectrum β-lactamases (ESBLs) are enzymes capable of hydrolyzing extended-spectrum cephalosporins, penicillins and monobactams but inactive against cephamycins and carbapenems. The ESBL-producing organisms are a breed of multidrug-resistant pathogens. Objectives: This study was aimed to determine the susceptibility pattern of ESBL-producing Escherichia coli to ciprofloxacin, amikacin and imipenem. Methods: A total of 75 ESBL-producing E. coli, were obtained from the tertiary care hospitals of Bangladesh and were studied for susceptibility pattern from October, 2010 to December, 2011. These isolates were identified by double disc synergy test (DDST) and were confirmed phenotypically as ESBL-producer by phenotypic confirmatory disc diffusion test (PCDDT). Minimum inhibitory concentrations (MICs) of ciprofloxacin, amikacin and imipenem among ESBL-producing E. coli were determined using agar dilution method. Results: Out of 75 DDST positive ESBL-producing E. coli, 71 (94.67%) were also positive by PCDDT. All ESBL-producing E. coli, were susceptible to imipenem. About 92.95% ESBL-producing E. coli were susceptible to amikacin but only 14.08% were susceptible to ciprofloxacin. Conclusion: In this study, ESBL-producing E. coli, showed high resistance to ciprofloxacin. Imipenem and amikacin were most effective against ESBL positive strains.

2015-2021年CHINET尿液分离菌分布和耐药性变迁

目的了解2015-2021年CHINET细菌耐药监测网中尿液分离菌的分布和耐药性。方法收集CHINET细菌耐药监测网51家医疗机构2015-2021年所有尿液标本临床分离菌的耐药监测数据资料,采用WHONET 5.6软件进行统计分析。结果2012-2021年尿液标本共分离细菌261893株,其中革兰阳性菌62219株,占23.8%,革兰阴性菌199674株占76.2%。常见的分离菌依次为大肠埃希菌(46.7%)、屎肠球菌(10.4%)、肺炎克雷伯菌(9.8%)、粪肠球菌(8.7%)、奇异变形杆菌(3.5%)、铜绿假单胞菌(3.4%)、无乳链球菌(2.6%)和阴沟肠杆菌(2.1%)。上述细菌主要分离自住院患者,女性多见于男性,成人多见于儿童。大肠埃希菌、肺炎克雷伯菌和奇异变形杆菌中产超广谱β内酰胺酶(ESBL)菌株分别占53.2%、52.8%和37.0%。耐碳青霉烯类的大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌和鲍曼不动杆菌中检出率分别为1.7%、18.5%、16.4%和40.3%。粪肠球菌对氨苄西林、呋喃妥因、利奈唑胺、万古霉素、替考拉宁和磷霉素的耐药率<10%,屎肠球菌对氨苄西林、左氧氟沙星、红霉素的耐药率>90%,对万古霉素、利奈唑胺和替考拉宁的耐药率<2%。ICU住院患者分离的大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌和鲍曼不动杆菌对大部分抗菌药物的耐药率明显高于门诊患者和非ICU住院患者。结论尿液标本临床分离菌主要以大肠埃希菌、肠球菌和肺炎克雷伯菌为主,不同人群尿液标本中分离的细菌种类和耐药性不尽相同,应重视细菌耐药监测,减少抗菌药物的不合理使用。

水源热泵回灌中大肠杆菌阻塞迁移沉积特性参数试验研究

以地下水源热泵回灌过程中大肠杆菌堵塞作为研究对象,通过自主研发的砂层颗粒迁移-沉积试验系统观察大肠杆菌在多孔介质孔隙孔道内的运移、沉积。以3种不同长度的试验箱体开展大肠杆菌在多孔介质里的运移沉积规律,通过试验得出:1)石英石颗粒内部的内摩擦力有利于大肠杆菌的沉积,流动速度对大肠杆菌引起的微生物堵塞起到关键作用:2)3种(60、80、100 cm)不同长度的试验箱体在流速作用下以100和80 cm为对象,其沉积率提高了57.1%;以80和60 cm为对比对象,其沉积率提高了27.3%;3)大肠杆菌的恢复率与流体速度也成正相关作用,其堵塞原理类似沉积率特性。

基于紫胶红素的靶标有色化免疫层析试纸条联检大肠杆菌O157∶H7和沙门氏菌

为摆脱免疫层析试纸条对配对抗体的依赖,文章设计了一种新型靶标有色化免疫层析试纸条,使用紫胶红素和十二合水硫酸铝钾媒染剂,通过先媒后染的方法,实现了免疫层析试纸条的“可视化”。验证结果显示,该试纸条对大肠杆菌O157∶H7和沙门氏菌的检测限均达到了106 CFU/mL;同时,与常见食源性致病菌间不存在交叉反应,在鸡胸肉、鸡蛋、牛奶等食品基质中能够在增菌9 h内检出。文章成功设计了一种操作简单、检测成本低,更易国产化的快速检测免疫层析试纸条,为后续免疫层析试纸条的设计提供了新思路。

秦皇岛地区鸡源大肠杆菌分离鉴定及药敏试验

试验旨在了解河北省秦皇岛地区养殖场鸡源大肠杆菌耐药情况,为该地区鸡大肠杆菌病的用药方案提供参考。采集秦皇岛市部分地区鸡场疑似感染大肠杆菌的病死鸡病料,采用细菌分离培养、革兰氏染色法和PCR鉴定对分离株进行鉴定,并进行药敏试验。结果显示:共检测出18株大肠杆菌,分离株对庆大霉素、丁胺卡那敏感;对哌拉西林、头孢哌酮、羧苄西林和头孢曲松呈中度耐药,耐药率为33.33%~50.00%;对青霉素、头孢他啶、苯唑西林、红霉素、头孢拉定和头孢氨苄高度耐药,耐药率为94.44%~100.00%。研究表明,应不定时检测当地鸡源大肠杆菌对常用抗生素药物的敏感性,以便及时快速地调整用药,避免造成耐药性。