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.

Detection of Drug Resistance in Escherichia coli Isolated from Animals and ERIC Analysis of Multidrug-resistant Strains

The drug resistance of Escherichia coli from animals was detected in Shandong Province in 2016,the gene mapping of Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR) of multidrug-resistant isolates were analyzed,and then the relationship between ERIC-PCR genotyping and drug resistance of highly-resistant E.coli with multidrug resistance was discussed.A total of 110 E.coli isolates were separated and identified from diseased swine and avian,and their resistance to 10 kinds of antimicrobials was determined by the agar dilution method.Twenty highly-resistant isolates with multidrug resistance were selected to carry on the ERIC-PCR,followed by cluster genetic analysis according to the DNA fingerprints.The swine-sourced E.coli isolates possessed serious resistance against several kinds of antimicrobial agents,for example,all isolates were tolerant to florfenicol,doxycycline and ampicillin (100%),but had a relative lower resistance rate to cefotaxime sodium (57.14%).The same situation was observed in the poultry-sourced E.coli isolates,which had a resistance rate of 95.51% against florfenicol,while the lowest rate of 61.80% appeared on ciprofloxacin.Analysis of ERTIC showed dispersive fingerprint patterns of highly-resistant and multidrug- resistant isolates which represented a multiple clone resources,and there were certain correlation between the B genotype and the drug-resistant characteristics.It indicated that the animal-sourced E.coli isolates had a high level of drug resistance and were multidrug-resistant,which meant there was severe antibiotic resistance against not only different kinds of antibiotics but also different drugs of the same kind.The highly-resistant E.coli isolates with multidrug resistance had no apparent species preference,while their spread and pervasion posed a potential threat to the development of animal husbandry and the public health security.

Isolation and Identification of Drug-resistant Escherichia coli Strains from Chickens

[Objective] This study aimed to isolate and identify the drug-resistant Es- cherichia coli strains from chickens. [Method] E. coli strains were isolated from the fecal samples collected from five chicken farms around Shangqiu City, and verified by biochemical and pathogenic assay. [Result] Among the 35 isolated E. coli stains, 11 E. coil stains were sensitive to florfenicol, amikacin, neomycin and gentamicin; 12 E. coli stains were moderately sensitive to ciprofloxacin, doxycycline and norfloxacin; 15 E. coil stains were resistant against erythromycin, penicillin and streptomycin. [Conclusion] Strengthening biosecurity measures, rationally using vaccine and choosing effective antibiotics are the most cost-efficient methods to control E. coli.

Antimicrobial Drug Resistance Pattern of <i>Escherichia coli</i>Isolated from Chickens Farms with Colibacillosis Infection

Colibacillosis refers to any localized or systemic infection caused entirely or partly by avian pathogenic Escherichia coli (APEC). Colibacillosis in mammals is most often a primary enteric or urinary tract disease, whereas colibacillosis in poultry is typically a localized or systemic disease occurring secondarily when host defenses have been impaired or overwhelmed by virulent E. coli strains. The purpose of this study was to investigate the antimicrobial drug resistance pattern of Escherichia coli isolated from broiler chickens farms with colibacillosis infection. Dead birds from commercial broiler chicken farms showing signs of colibacillosis were necropsied and swab samples were collected from internal organs and blood aseptically for the isolation of Escherichia coli. Pure colonies of the bacteria were isolated on solid media and the isolates were identified as E. coli based on morphological and biochemical characteristics. For determination of susceptibility to antibacterial agents, the disc diffusion method on Muller-Hinton agar was used. The following antimicrobial agents were tested: gentamycin, oxytetracyline, colistin, ciprofloxacin, doxycycline, nalidixic acid, co-trimoxazole (trimethoprim-sulfamethoxazole), norefloxacin, lincospectin and cefuroxime. The drug resistance patterns of the organisms were determined as a percentage and reported at three levels: susceptible, intermediate and resistant. All the isolates of Escherichia coli showed resistance to several antibiotics and a pattern of multiple drug resistance was observed. The highest rate of resistance was observed against nalidixic acid (100%) and the least rate of resistance was observed against gentamycin (17%). According to the results of this research care must be taken to avoid secondary infection (colibacillosis) in chicken farms and also avoid in careless antimicrobial consumption in food animals including chickens.

Comparison of extended spectrum β-lactamasesproducing Escherichia coli with non-ESBLsproducing E.coli:drug-resistance and virulence

The virulent factors of Escherichia coil （E.cofi） play an important role in the process of pathopoiesis. The study aimed to compare drug-resistant genes and virulence genes between extended spectrum β-1actamases （ESBLs）-producing E.coli and non-ESBLs-producing E.cofi to provide a reference for physicians in management of hospital infection. From October 2010 to August 2011,96 drug-resistant strains of E. coli isolated were collected from the specimens in Qingdao Municipal Hospital, Qingdao, China. These bacteria strains were divided into a ESBLs-producing group and a non-ESBLs-producing group. Drug sensitivity tests were performed using the Kirby-Bauer （K-B） method. Disinfectant gene, qacEAl-sull and 8 virulence genes （CNF2, hlyA, eaeA, VT1, est, bfpA, elt, and CNF1） were tested by polymerase chain reaction （PCR）. Among the 96 E.coli isolates, the ESBLs-producing E.coli comprised 46 （47.9%） strains and the non-ESBLs-producing E.cofi consisted of 50 （52.1%） strains. The detection rates of multiple drug-resistant strain, qacEAl-sull, CNF2, hlyA, eaeA,VT1, est, bfpA, elt, and CNF1 in 46 ESBLs-producing E.coli isolates were 89.1%, 76.1%, 6.5%, 69.6%, 69.6%, 89.1%, 10.9%, 26.1%, 8.7%, and 19.6%, respectively. In the non-ESBLs-producing E.cofi strains, the positive rates of multiple drug-resistant strain, qacEAl-sull, CNF2, hlyA, eaeA, VT1, est, bfpA, elt, and CNF1 were 62.0%, 80.0%, 16.0%, 28.0%, 64.0%, 38.0%, 6.0%, 34.0%, 10.0%, and 24.0%, respectively. The difference in the detection rates of multiple drug-resistant strain, hlyA and VT1 between the ESBLs-producing E.cofi strains and the non-ESBLs-producing E.cofi strains was statistically significant （P〈0.05）. The positive rate of multiple drug-resistant strains is higher in the ESBLs-producing strains than in the non-ESBLs-producing strains. The expression of some virulence genes hlyA and VT1 varies between the ESBLs-producing strains and the non-ESBLs-producing strains. Increased awareness of clinicians and enhanced testing by laboratories are required to reduce treatment failures and prevent the spread of multiple drug-resistant strains.

Analysis of the Drug Sensitivity of Escherichia coli Isolated from Sheep in Yangling,Shaanxi Province

This study was conducted to investigate the drug sensitivity of Escherichia coli isolated from sheep, providing data reference for clinical medication. Fifty-four samples were collected from a certain sheep farm in Yangling, Shaanxi Province for E. coli isolation and identification, and K-B disk diffusion method was used to carry out the dug sensitivity test of 40 E. coli to the eight antimicrobials of spectinomycin, amikacin, tobramycin, enrofloxacin, nalidixic acid, levofloxacin, salafloxacin and ciprofloxacin. The results showed that there were 40 positive E. coli strains and the isolation rate was 74.7%. The resistance rates of the 40 E. coli to spectinomycin, amikacin,tobramycin and nalidixic acid were 85%, 95%, 97.5% and 87.5%, respectively, while the resistance rate to enrofloxacin, levofloxacin, salafloxacin and ciprofloxacin were relatively low and the resistance rates were 35%, 20%, 25% and 17.5%, respectively. The isolates showed different levels of drug resistance to eight antimicrobials and the highest resistance rate was 97.5%. It reminds that the sheep farm should strictly control the dosage according to the antimicrobial sensitive data in clinic.

Multi-Drug Resistance Pattern of Lactose Non-Fermenting <i>Escherichia coli</i>as Causative Agent of Urine Tract Infections in Luanda, Angola

This prospective study was carried out to assess the sensitivity and resistance pattern of lactose non-fermenting Escherichia coli from July 2018 to December 2018 in the Laboratory of Microbiology at Luanda Medical Center, Angola. Out of 1170 patient, a total of 120 urine specimens infected with Escherichia coli (>105 CFU/ml) were collected according to the routine protocol of urinalysis. Among these 120 isolates, 25 (21%) isolates were determined as “atypical”, lactose non-fermenting E. colis trains. The twenty-five lactose non-fermenting Escherichia coli strains isolated from urine samples in Luanda Medical Center were declared as Multiple Drugs-Resistant strains with high resistance to Cefalexine (100%), Cefuroxime (100%), Ceftriaxone (92%), Gentamycin (92%), Ciprofloxacin (72%) and Amoxiciclin/Clavulanic (80%). The alarming resistance level to the first-choice drugs for the treatment of urinary tract infections caused by non-fermentative lactose E. coli was observed.

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.

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.

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.

Prevalence,serotyping and drug susceptibility patterns of Escherichia coli isolates from kidney transplanted patients with urinary tract infections

BACKGROUND Extended-spectrumβ-lactamase(ESBL)-producing Escherichia coli(E.coli)are among the main pathogens in urinary tract infections(UTIs)among kidney transplant patients(KTPs).AIM To estimate the prevalence of ESBL-producing E.coli in KTPs and to evaluate the most prevalent serotypes and antibacterial susceptibility patterns of isolated bacteria in Tehran,Iran.METHODS A total of 60 clinical isolates of uropathogenic E.coli were collected from 3 kidney transplant centers from April to May 2019.Antimicrobial susceptibility testing was performed by the disk diffusion method as recommended by the Clinical Laboratory and Standards Institute.The serotyping of E.coli isolates was performed by the slide agglutination method.The presence of blaTEM,blaSHV,and bla CTX-M genes was evaluated by polymerase chain reaction.RESULTS The frequency of ESBL-producing E.coli in KTPs was found to be 33.4%.All of the 60 E.coli isolates were found to be susceptible to doripenem(100%)and ertapenem(100%).High resistance rates to ampicillin(86%),cefotaxime(80%),and cefazolin(77%)were also documented.The most frequent serotypes were serotype I(50%),serotype II(15%),serotype III(25%),and serotype VI(10%).The gene most frequently found was blaTEM(55%),followed by blaCTX-M(51%)and blaSHV(41%).CONCLUSION Molecular analysis showed that blaTEM was the most common ESBL-encoding gene.The high resistance toβ-lactams antibiotics(i.e.,ampicillin,cefotaxime,and cefazolin)found in E.coli from KTPs with UTIs remains a serious clinical challenge.Further efforts to control ESBL-producing E.coli should include the careful use of all antibiotics as well as barrier precautions to reduce spread.

Study on the Resistance of Pathogenic Escherichia coli to Ceftiofur

[Objective] Ceftiofur was as the substrate to induce the standard strain of Escherichia coli（E.coli）to be the drug-resistance one.The resistant mechanism of E.coli to ceftiofur was studied.[Method] The sub-inhibitory concentration method was used to induce the standard strains C83907 and C83845.After they were induced for 10 generations,the double disc synergy test（DDST）,NCCLS（National Committee for Clinical Laboratory Standards）confirmatory test and PCR amplification were used to detect the extend spectrum β-lactamases（ESBLs）.The two fold dilution method was used to measure the minimal inhibitory concentration（MIC）of cetiofur to the strain which produced ESBLs.For the drug-resistance strain which produced ESBLs,the two fold dilution method was used to measure the minimal inhibitory concentrations of different proportions of cetiofur and tazobactam sodium.[Result] After they were induced 15 generations,MIC value of ceftiofur to the induced bacteria was during 8-10 μg/ml,and ESBLs was detected.MICs of cetiofur combining tazobactam sodium（the mass ratio was 1∶1-8∶1）to Escherichia coli produced ESBLs reduced 20-22 times than that of cetiofur.[Conclusion] The main mechanism of pathogenic Escherichia coli resistance to ceftiofur was that which produced ESBLs.

In vitro biofilm formation by uropathogenic Escherichia coli and their antimicrobial susceptibility pattern

Objective:To detect in vitro biofilm formation of uropathogenic Escherichia coli(E.coli)(UPEC) strains isolated from urine specimens and also to determine their antimicrobial susceptibility pattern using 13 commonly used antibiotics.Methods:The present study comprised of 166 urine specimens collected from tertiary care hospitals in and around Coimbatore.South India. All the specimens were subjected to gram staining,bacterial culture and the E.coli strains were screened for biofilm formation using Tube Method(TM),Congo Red Agar(CRA) and Tissue Culture Plate method(TCP) respectively.Subsequently,the antimicrobial susceptibility test was performed by Kirby Bauer-disk diffusion method for the biofilm and non-biofilm producing E. coli strains.Results:Of the 100(60.2%) E.coli strains,72 strains displayed a biofilm positive phenotype under the optimized conditions in the Tube Method and the strains were classified as highly positive(17,23.6%),moderate positive(19.26.3%) and weakly positive(36.50.0%). similarly under the optimized conditions on Congo Red agar medium,biofilm positive phenotype strains were classified as highly positive(23,23%).moderate positive(37.37%) and weakly positive(40,40%).While in TCP method,the biofilm positive phenotype strains were also classified as highly positive(6.6%),moderate positive(80.80%) and weakly positive(14,14%),it didn’t not correlate well with the tube method for detecting biofilm formation in E.coli.The rates of antibiotic resistance of biofilm producing E.coli were found to be 100%for chloramphenicol and amoxyclav(amoxicillin and clavulanic acid),86%for gentamicin and cefotaxime.84%for ceftazidime,83%for cotrimoxazole and piperacillin/tazobactam,75%for tetracycline and 70% for amikacin,Conclusions:This study reveals the prevalence and antimicrobial susceptibility pattern of biofilm and non-biofilm producing uropathogenic E.coli strains.

信阳地区鹅源大肠杆菌的分离鉴定、系统进化分群与耐药性分析

为了解信阳地区鹅源大肠杆菌的系统进化分群、毒力基因携带情况和耐药情况,试验从信阳地区部分养殖户送检的46只疑似大肠杆菌感染病鹅的肝脏、脾脏等组织中进行大肠杆菌的分离、鉴定,并对分离菌株进行系统进化分群、毒力基因检测、耐药性分析、耐药基因检测。结果表明:共分离到23株大肠杆菌,分别命名为GE1~GE23。23株大肠杆菌在4种系统进化群中均有一定比例的分布,其中A群有3株(GE11、GE12、GE19,占比为13.04%),B1群有3株(GE4、GE15、GE23,占比为13.04%),B2群有9株(GE1、GE2、GE8、GE10、GE14、GE16、GE17、GE20、GE21,占比为39.13%),D群有8株(GE3、GE5、GE6、GE7、GE9、GE13、GE18、GE22,占比为34.78%)。在毒力基因检测中,23株大肠杆菌marA、fimC、fyuA、iroN、iss、hlyF、ompT、iutA和irp2基因的检出率分别为100%、95.65%、52.17%、47.83%、43.48%、39.13%、34.78%、30.43%和17.39%。23株分离菌对阿莫西林/克拉维酸钾的耐药率最高,为65.22%;然后依次为磺胺甲口恶唑/甲氧苄啶、强力霉素、氟苯尼考、多黏毒素B、头孢噻呋和左氧氟沙星、环丙沙星,耐药率分别为56.52%、52.17%、47.83%、34.78%、17.39%和17.39%、8.70%。23株分离菌对亚胺培南的敏感率最高,为100%;然后依次为丁胺卡那、链霉素、新霉素、环丙沙星和左氧氟沙星、头孢噻呋、氟苯尼考、多黏菌素B、强力霉素、磺胺甲口恶唑/甲氧苄啶,敏感率分别为82.61%、82.61%、47.83%、47.83%和47.83%、34.78%、26.09%、21.74%、17.39%、8.70%。23株分离菌中有12株表现为多重耐药,其中6,7耐菌株各有1株,占比为4.35%;4,5耐菌株各有3株,占比为13.04%;3耐菌株有4株,占比为17.39%。在耐药基因检测中,tetA基因的检出率最高,为82.61%;然后依次为folR、sul2、aadA、bla_(TEM)、bla_(CTX-M)、aphA1、clmA、sul3、sul1、aphA2,检出率分别为73.91%、65.22%、56.32%、52.17%、47.83%、47.83%、43.48%、26.09%、13.04%和13.04%。说明信阳地区鹅源大肠杆菌B2群和D群占比较大,携带多种毒力基因和耐药基因,且多表现为多重耐药。

兔源肺炎克雷伯氏菌和大肠埃希氏菌的分离鉴定及小鼠感染试验

为确定某规模化兔场仔兔呼吸道感染合并腹泻引起死亡的原因,无菌采集病兔气管、肺、肝组织进行病毒和细菌检测。通过细菌分离培养、革兰氏染色、生化鉴定、16S rRNA序列同源性比对分析,确定分离菌株种属。通过药物敏感性试验、耐药基因检测及动物回归对分离菌株的耐药性和致病性进行分析。结果显示,病毒检测结果均为阴性;从同一只仔兔的肺脏、气管中分离得到2株肺炎克雷伯氏菌,分别将其命名为KF1、KQ2,从肝脏中分离得到1株大肠埃希氏菌并将其命名为EG3。药敏试验结果显示,菌株KF1、KQ2和EG3均对黏菌素和氨苄青霉素钠耐药,对阿米卡星和氟苯尼考敏感。3株菌均检出耐药基因mcr-1和bla TEM。动物致病性试验显示,KF1组小鼠5 h后死亡50%,24 h全部死亡;混合组小鼠12 h后全部死亡;KQ2和EG3组48 h全部死亡。以上研究表明,大肠埃希氏菌和肺炎克雷伯氏菌的混合感染是引起仔兔死亡的主要原因,3株分离株单独及混合感染均能引起试验小鼠死亡。

江苏部分地区鸡源大肠杆菌的分离鉴定及生物学特性研究

为研究江苏地区鸡源大肠杆菌的血清型、毒力基因分布、进化分群及耐药性等生物学特性,试验从江苏部分地区养鸡场的疑似大肠杆菌感染病例中,分离并鉴定出鸡大肠杆菌44株,采用平板凝集法检测分离菌O抗原血清型,PCR法检测分离菌的毒力基因分布、系统进化分类,Kirby-Bauer纸片扩散法检测分离菌的耐药情况。结果显示:44株分离菌中O抗原血清型菌株有38株,共有17种血清型,其中O138(15.8%)、O86(13.2%)、O54(10.5%)和O14(10.5%)为优势血清型;fimC、yijp检出率最高,均为100%(44/44)携带,其次为mat、iucD、ompA、iss,分别为97.73%(43/44)、84.09%(37/44)、79.55%(35/44)、59.09%(26/44),且分离菌全部同时含有3种或以上的毒力基因;分离菌主要属于A、D群,占比分别为38.64%和31.83%,少数为B1、B2群,占比分别为11.36%和18.18%;44株分离菌均对红霉素、克林霉素、万古霉素100%耐药,对四环素、复方新诺明的耐药率均为86.36%,且多重耐药现象明显。研究提示,江苏部分地区鸡源大肠杆菌血清型复杂多样,携带多种毒力基因,且耐药问题比较严重,应加强当地耐药菌的监测,从而选择合适的药物防治鸡大肠杆菌病。

2016—2023年上海市浦东新区和松江区畜禽源大肠埃希菌耐药性比较

为了调查2016—2023年上海市浦东新区和松江区(下文简称“两区”)畜禽源大肠埃希菌(E.coli)的耐药性变迁情况,本试验从两区畜禽养殖场分别采集401和490份畜禽肛拭子进行大肠埃希菌的分离鉴定,并调查养殖场的抗菌药物使用情况;采用微量肉汤稀释法测定分离的大肠埃希菌对10大类14种抗菌药物的敏感性。结果显示,两区不同养殖场的抗菌药物使用情况存在差异。两区分别分离到333和350株大肠埃希菌,分离率为83.04%和71.43%。两区分离菌株对四环素(87.09%,82.00%)、磺胺异噁唑(77.78%,82.00%)、氨苄西林(82.58%,70.30%)和复方新诺明(70.87%,76.90%)的耐药率较高,对头孢他啶(6.61%,6.90%)和黏菌素(0.90%,0.90%)较为敏感,未检测到美罗培南耐药菌株;多重耐药菌株占比分别为87.99%和81.71%。8年间,两区分离菌株对多数抗菌药物的耐药率、多重耐药菌株占比和耐药谱数量整体呈下降趋势,松江区下降趋势更明显。结果表明,浦东新区和松江区畜禽源大肠埃希菌对部分抗菌药物的耐药率高且多重耐药情况严重,在减抗背景下,两区耐药水平均有缓解,松江区缓解程度更大。

“黄金洗剂”逆转ESBLs+E.coli耐药性的体外实验研究

目的探讨中药“黄金洗剂”对产超广谱β-内酰胺酶的大肠埃希菌(ESBLs+E.coli)的体外抗菌效果及其逆转细菌耐药的部分机制。方法通过肉汤稀释培养法确定“黄金洗剂”对ESBLs+E.coli的最低抑菌浓度(MIC),然后应用改良Kirby-Bailer法分析“黄金洗剂”对ESBLs+E.coli耐药性的逆转效果,最后通过结晶紫染色分析生物膜形成能力和检测ESBLs酶活性来探讨“黄金洗剂”逆转细菌耐药的机制。结果“黄金洗剂”对ESBLs+E.coli的MIC为0.6 g/mL,其最佳抑菌条件是0.5 g/mL的药物浓度作用细菌24 h。此时“黄金洗剂”能够逆转细菌对第四代头孢菌素头孢吡肟的耐药性[(13.9±1.2)%],而对第三代头孢菌素头孢噻肟和头孢曲松的逆转率很低。进一步研究发现“黄金洗剂”能够逆转细菌耐药是因为该中药能够抑制生物膜形成,抑制ESBLs酶活性。结论“黄金洗剂”在0.5 g/mL条件下作用细菌24 h能够明显逆转细菌对头孢吡肟的耐药性,主要通过抑制细菌生物膜的形成和ESBLs的酶活性来实现。

鬼针草血清与抗菌药联合对耐药E.coli体外抑菌的研究

为了探讨鬼针草血清与抗菌药联合诱导细菌传代的体外抑菌活性,试验制备了鬼针草含药血清,采用二倍微量稀释法体外检测鬼针草血清与抗菌药联合诱导耐药大肠杆菌的抑菌传代情况。结果表明:鬼针草血清与抗菌药联合诱导细菌传代对耐药大肠杆菌有不同程度的抑菌活性。说明鬼针草血清可明显增强β-内酰胺类、氨基糖苷类和酰胺醇类抗菌药对耐药菌的抑制作用。

大肠埃希菌的临床分布、耐药性及碳青霉烯耐药株基因序列分析

目的分析大肠埃希菌的临床分布、耐药性及碳青霉烯耐药株基因序列。方法选取2021年1月至2023年12月山东省潍坊市中医院送检标本中分离的1837株大肠埃希菌为研究样本,分析大肠埃希菌的临床科室分布、样本类型分布、抗菌药物耐药情况、碳青霉烯类耐药情况以及碳青霉烯类耐药基因检测结果。结果1837株大肠埃希菌主要分布在泌尿外科(13.4%),主要样本类型为尿液(43.3%)。大肠埃希菌对阿米卡星、呋喃妥因、亚胺培南、美罗培南、哌拉西林/他唑巴坦、厄他培南的敏感性较高,对氨苄西林、环丙沙星、左氧氟沙星的耐药率较高。1038(56.5%)株为产超广谱β-内酰胺酶(ESBLs)阳性,有57株(3.1%)为耐碳青霉烯类大肠埃希菌(CREC)。基因序列分析发现,耐药基因存在碱基序列的缺失和/或增加,可能对菌株的抗菌药物敏感性产生影响。结论大肠埃希菌广泛分布于医院各科室,其对青霉素和β-内酰胺类抗菌药物呈现出一定的耐药性。