Antibiotic resistance in Escherichia coli causing generalized infections in chickens in the UK in 1982: the relationship between the results of in vitro and in vivo furazolidone sensitivity tests

Compared with a similar survey conducted ten years previously, a survey conducted in 1982, eleven years after the implementation of legislation forbidding the routine use of feeds containing 'therapeutic' antibiotics, revealed a decreased incidence of resistance to tetracyclines, furazolidone and sulphonamides in Escherichia coli strains causing generalized infections in chickens in the UK; the decrease was particularly marked in the case of tetracycline resistance, 17.9% of strains in 1982 being resistant to this antibiotic compared with 31.2% in 1972. Giving furazolidone to groups of chickens inoculated intramuscularly with O2:K1 strains of E. coli of differing degrees of furazolidone sensitivity indicated that great care is required in the performance and interpretation of laboratory tests for sensitivity to this antibiotic. Infections caused by strains that required as little as 1.25 micrograms/ml of furazolidone to inhibit their multiplication in laboratory tests responded poorly to furazolidone treatment; those that were inhibited by less responded well, better than to treatment with tetracycline, chloramphenicol, ampicillin or trimethoprim.     

Antibiotic resistance in Escherichia coli causing generalized infections in chickens in the UK in 1982: the relationship between the results of in vitro and in vivo furazolidone sensitivity tests.

Compared with a similar survey conducted ten years previously, a survey conducted in 1982, eleven years after the implementation of legislation forbidding the routine use of feeds containing ''therapeutic'' antibiotics, revealed a decreased incidence of resistance to tetracyclines, furazolidone and sulphonamides in Escherichia coli strains causing generalized infections in chickens in the UK; the decrease was particularly marked in the case of tetracycline resistance, 17.9% of strains in 1982 being resistant to this antibiotic compared with 31.2% in 1972. Giving furazolidone to groups of chickens inoculated intramuscularly with O2:K1 strains of E. coli of differing degrees of furazolidone sensitivity indicated that great care is required in the performance and interpretation of laboratory tests for sensitivity to this antibiotic. Infections caused by strains that required as little as 1.25 micrograms/ml of furazolidone to inhibit their multiplication in laboratory tests responded poorly to furazolidone treatment; those that were inhibited by less responded well, better than to treatment with tetracycline, chloramphenicol, ampicillin or trimethoprim.     

Occurrence of quinolone resistance in Staphylococcus aureus from nosocomial infection.

Among 63 Staphylococcus aureus isolates (one isolate per one patient) counted from infections (from August to November 1991) in hospital T., eight exhibited resistance to fluoroquinolones. Seven of these quinolone-resistant isolates were multiply- and methicillin-resistant S. aureus (QR-MRSA). The results of phage-, plasmid- and genotyping (pulsed field electrophoresis) revealed that six different strain-clones of these MRSA were spread in the hospital. In vitro spontaneous mutants resistant to fluoroquinolones are 10-100-fold more frequent in MRSA than in other S. aureus when selected on isosensitest-agar containing 1 microgram/ml of ciprofloxacin. However, the same mutant frequencies were found in strain 8325-4 with and without the mecA-determinant. The resistance phenotype was stable over 30 generations of subculture in nutrient broth as well in natural quinolone resistant MRSA as in mutants of other types of S. aureus selected in vitro. The phenotypic association of quinolone resistance and MRSA is rather likely due to a higher frequency of spontaneous resistant mutants which are present in natural populations of MRSA. Data of chemotherapy prior to the isolation of S. aureus show that three of seven patients from whom QR-MRSA were isolated were treated with a quinolone. In eight cases of infections with non-MRSA and quinolone treatment the isolated S. aureus strains were in vitro sensitive to quinolones.     

Escherichia coli resistant to tetracyclines and to other antibiotics in the faeces of U.K. chickens and pigs in 1980.

A survey conducted in 1980, 9 years after the banning of the use of tetracyclines as feed additives in the U.K., indicated that table chickens and pigs were still a large reservoir of tetracycline-resistant Escherichia coli; the incidence of transferable tetracycline resistance was greater in chicken E. coli strains (68%) than in pig E. coli strains (20%). Large amounts of sulphonamide-resistant and of furazolidone-resistant E. coli were found in the faeces of chickens; E. coli resistant to both sulphonamides and streptomycin were common in the faeces of chickens and pigs. E. coli with transferable or mobilizable trimethoprim resistance were present in the faeces of most pigs and in the faeces of 10% of chickens.     

The effect of antibiotic therapy on the faecal excretion of Salmonella typhimurium by experimentally infected chickens.

Chickens in groups of 40 were infected orally with a nalidixic acid-resistant mutant of Salmonella typhimurium and then fed continuously on diets containing ampicillin, chloramphenicol, furazolidone, neomycin, oxytetracycline, polymixin, spectinomycin, streptomycin or a mixture of trimethoprim and sulphadiazine. The amount of S. typhimurium excreted in their faeces was estimated at intervals by culture on brilliant green agar containing sodium nalidixate, both direct and after enrichment in selenite broth; the amount of Escherichia coli excreted was estimated by culture on MacConkey agar. The feeding of diets containing 500 mg./kg. of ampicillin, furazolidone, neomycin, polymixin, spectinomycin or streptomycin or 100 mg./kg. of trimethoprim and 500 mg./kg. of sulphadiazine for 46 days reduced to a varying degree the amount of S. typhimurium and E. coli excreted, the greatest reduction in S. typhimurium being brought about by the last treatment. The effect was less obvious when the concentration of the antibiotics in the food was decreased fivefold. An important reason for the very limited effect of some of the antibiotics was the emergence of antibiotic-resistant populations of S. typhimurium and E. coli. High concentrations of antibiotic-resistant organisms also arose in the faeces of the chickens fed diets containing tetracyclines and chloramphenicol, treatments which had no apparent effect on the amount of S. typhimurium and E. coli excreted. Much of the antibiotic resistance encountered was determined by R factors, a particular R factor usually being found in the E. coli populations of individual chickens before it was found in their S. typhimurium populations. No S. typhimurium or E. coli were isolated that possessed R factors determining resistance to polymixin, furazolidone or trimethoprim. No S. typhimurium or E. coli were isolated that were polymixin-resistant and no S. typhimurium that were furazolidone-resistant. The few trimethoprim-resistant S. typhimurium isolated were thymine-dependent. The feeding of diets containing the higher concentrations of trimethoprim/sulphadiazine, neomycin, furazolidone or ampicillin for 9 days reduced the amount of S. typhimurium excreted. After the withdrawal of these diets, the amount of S. typhimurium excreted increased to the numbers found in chickens given ordinary diets throughout; the chickens that had been given trimethoprim/sulphadiazine or furazolidone did not remain faecal excreters of S. typhimurium longer than the chickens that had been given ordinary diets. Similar results were obtained with trimethoprim/sulphadiazine when the start of the 9-day treatment period was delayed for an extra 9 days or when it was extended to 18 days.     

Erythromycin and anaerobes: in vitro aspects.

Anaerobic organisms are being increasingly recognised as important causes of serious infection in man. Sampling procedures, transport of specimens and laboratory techniques need to be constantly monitored and improved if the causative organisms are to be consistently recovered from clinical specimens. Once the organisms have been isolated, their susceptibility to antibiotics should be determined so that the clinician can base his antibiotic therapy on reliable laboratory results. There are many variables in the sensitivity testing of anaerobes--these may account for the difficulty reported by some workers in obtaining consistently reliable results with some antibiotics, including erythromycin. These problems can be largely overcome if a standardised procedure is adopted. It is clear from the published data that erythromycin has considerable in vitro activity against many strains of anaerobic bacteria, both sporing and non-sporing. There is a broad spectrum of activity with some strains being very sensitive and a few strains being resistant. M.I.C. values range from 0.04 microgram./ml. to 20 microgram./ml. or more. Further studies are now needed to assess the role of erythromycin in the treatment of anaerobic infections in vivo.     

Factors affecting the incidence and anti-salmonella activity of the anaerobic caecal flora of the young chick.

Thirty-two different types of anaerobic bacteria isolated from chickens have been tested for anti-salmonella activity in vitro. Under the conditions of the test only Bacteroides hypermegas and a Bifidobacterium sp. were shown to inhibit the salmonellas and this was attributed to the production of volatile fatty acids (VFA's) coupled with a low pH. When these organisms were tested in newly hatched chicks no inhibition of S. typhimurium occurred. Possible explanations for this observation are considered. The pH value and concentration of VFA's in the caecal material were determined in chicks from 0-84 days. In vitro tests with S. typhimurium indicated that, whilst the organism would be able to multiply at the pH and concentration of VFA's found during the first few days after hatching, the rapid increase in VFA concentration during the first 21 days would make this increasingly difficult. The significance of the developing caecal flora in relation to VFA production and pH is discussed. Because certain feed additives are known to influence the carriage of salmonellas, the sensitivity of various caecal anaerobes to these compounds was determined in vitro, generally at 1, 10 and 100 microgram/ml. The additives tested included flavomycin, furazolidone, nitrovin, tetracyline, tylosin, sulphaquinoxaline, virginiamycin and zinc bacitracin. All the organisms tested were inhibited by 100 microgram/ml furazolidone; none were inhibited by 500 microgram/ml sulphaquinoxaline. Changes occurring in the VFA concentration, pH value and microflora of the caeca of chicks fed for 49 days or longer on a normal starter diet or the same diet containing 10 or 100 mg/kg nitrovin have been compared. When the chicks were fed on the diet containing 100 mg/kg nitrovin, the Gram-negative non-sporing anaerobes were eliminated as a significant part of the caecal flora. However, the VFA concentration combined with a low pH in chicks from 2 weeks onwards was still sufficient to inhibit salmonella multiplication. Other possibly interrelated factors which might lead to an increased salmonella carrier rate in the nitrovin-treated chickens are discussed.     

儿童产超广谱β 内酰胺酶细菌感染耐药性研究 FREE

目的比较儿童送检标本分离的产超广谱β 内酰胺酶(Extended spectrum beta lactamase, ESBLs)细菌的耐药性,为临床抗ESBLs菌株感染治疗提供参考依据。方法抽取山西省儿童医院2007年1月-2009年4月各类送检标本分离的ESBLs阳性和阴性菌株各100株进行耐药性比较。结果200株菌株对亚胺培南全部敏感;而对其他11种抗菌药物的耐药性,ESBLs阳性菌株均高于ESBLs阴性菌株（P≤0.001）。其中ESBLs阳性菌株除对头孢哌酮/舒巴坦的耐药率较低（13.00%）外,对其余头孢类抗生素的耐药率均＞98%;对庆大霉素和环丙沙星的耐药率分别高达69.07%和59.18%。结论儿童分离的ESBLs阳性菌对碳青霉烯类或加酶抑制剂复合抗菌药物（如头孢哌酮/舒巴坦）较敏感。     

Isolation of Neisseria meningitidis strains with increase of penicillin minimal inhibitory concentrations

We report the isolation and characterization of ten strains showing an increase in the minimal inhibitory concentrations to penicillin (MICs greater than 0.1 microgram/ml), and describe the epidemiological, clinical and microbiological features. The susceptibility of 3432 meningococcal strains isolated from patients in the recent epidemic wave (1978-86) in Spain, to several antimicrobial agents used in the treatment and chemoprophylaxis of meningococcal infection has been tested. Most were resistant to sulphadiazine but sensitive to other antibiotics. The possible existence of a new pattern of behaviour of meningococcal to penicillin is discussed.     

The Kenyan Saradidi community malaria project: I. Response of Plasmodium falciparum isolates to chloroquine in 1981 and 1982

In 1981, 41 schoolchildren from Saradidi, Kenya, infected with Plasmodium falciparum were treated with chloroquine. All 41 infections were sensitive in vivo: parasitaemia cleared by day 3 and remained absent through day 7. All 17 (of 27) isolates successfully tested for chloroquine sensitivity in vitro were sensitive in the Rieckmann macro test: greater than 1% schizont development did not occur at chloroquine concentrations of greater than 1.25 nmol per ml of blood. In 1982 in the same area 20 P. falciparum infections were sensitive in vivo: parasitaemia cleared by day 5 and did not recur through day 7. Two of the 20 isolates were resistant in vitro with persistent schizont development at greater than 1% of control values at chloroquine concentrations of 1.5 and 3.0 nmol/ml in the macro test and 16 and 32 pmol/well in the Rieckmann micro test (compared with inhibition at less than or equal to 1.25 nmol/ml and less than or equal to 5.7 pmol/well, respectively, for sensitive isolates). In a modified 48-hour test, growth of two additional isolates was not inhibited until chloroquine concentration of 0.06 nmol per ml of medium, a pattern intermediate between that observed with known chloroquine-sensitive (less than or equal to 0.03 nmol/ml) and resistant (greater than or equal to 0.1 nmol/ml) P. falciparum isolates. The results demonstrate a changing pattern of the in vitro response of P. falciparum isolates in Saradidi to chloroquine.     

胆道感染细菌学检验与耐药性分析

目的 了解胆道感染病原菌的种类及其对抗菌药物的耐药性,以指导临床用药.方法 调查医院2009年9月-2011年9月收治的170例胆道感染患者,所有患者均通过抽取病变胆囊内胆汁4～6 ml进行细菌培养以及药敏试验.结果 170例患者共培养出病原菌120株,检出率为70.6％;其中革兰阳性菌42株占35.0％;革兰阴性菌78株占65.0％;革兰阳性菌对青霉素类和喹喏酮类敏感率均＞80.0％,对万古霉素敏感率为100.0％;革兰阴性菌对亚胺培南的敏感率为100.0％.结论 胆道感染病原菌以革兰阴性菌为主,普通感染可选用喹喏酮类或氨基糖苷类抗菌药物,中、重度感染可选用头孢哌酮/舒巴坦或哌拉西林/他唑巴坦,严重感染可选用亚胺培南.     

The virulence of trimethoprim-resistant thymine-requiring strains of Salmonella.

A thymine-requiring (thy-), trimethoprim-resistant (tmpr) mutant isolated from the faeces of chickens experimentally infected with salmonella typhimurium and treated with mixture of trimethoprim and sulphadiazine was less virulent for chickens than the parent strain and a thy+tmps revertant prepared in vitro from the mutant. The difference in chicken-virulence was more noticeable when the strains were administered orally than when they were administered subcutaneously. All tmpr mutants prepared in vitro from four other salmonella strains were also thy-; those tested were less virulent for chickens and mice than their parent strains. After oral infection, thy- salmonella organisms were found much less commonly in the alimentary tract of chickens then were thy+ organisms. This was especially so in the caeca, the principal site of colonization of both the thy+ and thy- organisms. Relatiely high concentrations of thymine or related compounds were found in the contents of all regions of the alimentary tract of chickens except the caeca; the caeca usually contained low or undetectable concentrations. The thy- salmonella strains would not grow on one brand of briliant green agar because of its deficiency in thymine; their colonial and appearance on other kinds of media used for isolating salmonellae from clinical material was often 'un-salmonella-like'.     

神经外科术后患者脑脊液中革兰阳性菌的分布及耐药性分析

目的 了解2011-2015年神经外科术后脑脊液培养阳性患者的革兰阳性菌临床分布情况与耐药性.方法 对2011年1月至2015年12月首都医科大学附属北京天坛医院神经外科术后患者脑脊液培养阳性的革兰阳性菌进行分析,且分别对临床诊断真感染的凝固酶阴性葡萄球菌(CoNS)、金黄色葡萄球菌、粪肠球菌与屎肠球菌的耐药情况进行分析.结果 2011-2015年,神经外科术后分离出革兰阳性菌共1 284株,分离率为4.53％,其中表皮葡萄球菌、人葡萄球菌和金黄色葡萄球菌的分离率最高,依次为38.32％、12.31％和10.75％;共分离出987株CoNS,其中真感染210株(21.28％).药敏试验结果显示,革兰阳性菌对万古霉素、利奈唑胺与替考拉宁敏感度最高均大于90.00％;真感染CoNS对万古霉素与利奈唑胺无法达到100.00％敏感率,对阿米卡星与利福平的敏感率大于90.00％;金黄色葡萄球菌对苯唑西林和四环素耐药率较高,肠球菌对多种药物均有较高耐药率.结论 神经外科术后革兰阳性菌感染问题较为严重,由于CoNS的感染不确定性,以及金黄色葡萄球菌与肠球菌感染的严重性,临床治疗时需特别注意.万古霉素、替考拉宁与利奈唑胺治疗神经外科术后革兰阳性菌感染较有效.     

下肢动脉急性缺血患者手术部位感染的病原菌分布及耐药性分析

目的分析下肢动脉急性缺血患者手术部位感染(surgical site infections,SSI)的病原菌分布及耐药性,为制订有效的抗感染治疗方案提供研究依据。方法选取2015年1月-2019年1月天津医院的91例下肢动脉急性缺血合并SSI患者作为研究对象,采集其切口分泌物样本,培养分离病原菌并进行药敏试验,对病原菌分布和耐药性进行回顾性分析。结果在71例患者的分泌物样本中检出病原菌,检出率为78.02%,共检出71株病原菌,其中,53株为革兰阳性菌占74.65%,以金黄色葡萄球菌、表皮葡萄球菌、溶血葡萄球菌为主,18株为革兰阴性菌占25.35%,以大肠埃希菌、肺炎克雷伯菌为主。金黄色葡萄球菌、表皮葡萄球菌、溶血葡萄球菌对青霉素G、氨苄西林、磺胺甲噁唑/甲氧苄啶、红霉素、克拉霉素的耐药株数较多,对利福平、庆大霉素的耐药株数较少。大肠埃希菌、肺炎克雷伯菌对氨苄西林、磺胺甲噁唑/甲氧苄啶、头孢唑林、环丙沙星的耐药株数较多,对头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、丁胺卡那的耐药株数较少。结论革兰阳性菌是导致下肢动脉急性缺血患者SSI的主要病原菌,这些病原菌对多种抗菌药物具有较高的耐药性,临床医生应选取敏感性抗菌药物进行抗感染治疗。     

呼吸科住院病例医院感染影响因素及病原菌耐药性分析

目的 探讨呼吸科住院病例医院感染病原菌分布及耐药性。方法 通过查阅住院病历的方法,回顾性分析2018年3月至2020年1月郑州市某医院呼吸科接受治疗的982例住院病例资料。统计发生医院感染情况、感染病原菌分布及耐药性,采用单因素和多因素Logistic回归分析呼吸科住院病例医院感染发生的影响因素。结果 共纳入住院病例982例,发生医院感染59例,感染率为6.01％,以下呼吸道感染为主（22例,37.29%）。共培养分离病原菌86株,其中革兰阴性菌41株（47.67%）,革兰阳性菌12株（13.96%）,真菌33株（38.37%）。革兰阴性菌以铜绿假单胞菌和肺炎克雷伯菌为主（20株,23.26%）,革兰阳性菌以金黄色葡萄球菌为主（9株,10.47%）,真菌感染以白色念珠菌为主（22株,25.58%）。铜绿假单胞菌对氨苄西林、氨苄西林/舒巴坦和替加环素的耐药率为100%,对头孢唑啉、头孢曲松和头孢替坦的耐药率均在80.00%以上,对妥布霉素敏感。肺炎克雷伯菌对常用抗菌药物的耐药率为12.50%~25.00%。金黄色葡萄球菌对青霉素G的耐药率为 83.33%,对红霉素的耐药率为50.00%,对利福平、利奈唑胺、万古霉素、四环素和替加环素均敏感。白色念珠菌对氟康唑、伊曲康唑、两性霉素B和伏立康唑均敏感。单因素分析显示,年龄、合并基础疾病、有侵入性操作、抗生素应用不合理、住院时间、激素与免疫抑制剂应用与呼吸科住院病例医院感染发生有关（均P<0.05）;多因素Logistic回归分析结果显示,年龄为61~78岁（OR=2.115）、住院时间≥15 d（OR=2.895）、合并基础疾病（OR=1.636）、有侵入性操作（OR=3.267）均是呼吸科住院病例医院感染发生的危险因素。结论 呼吸科住院病例医院感染多发生在下呼吸道,以革兰阴性菌和真菌为主,对多数药物均具有一定的耐药性,而年龄61~78岁、住院时间≥15 d、合并基础疾病、有侵入性操作均是呼吸科住院病例医院感染发生的独立危险因素。     

产ESBLs及AmpC大肠埃希菌耐药性分析

目的调查对头孢菌素耐药的大肠埃希菌的耐药机制及对15种抗生素的耐药性与耐药特点。方法对华中科技大学同济医学院附属同济医院检验科2004年1~12月临床分离的468株大肠埃希菌采用琼脂二倍稀释法测定15种抗生素的最低抑菌浓度(MIC),标准纸片扩散法检测超广谱β-内酰胺酶(ESBLs),改良三维试验检测头孢菌素酶(AmpC)。结果468株大肠埃希菌中检出ESBLs153株,检出率32.7%(153/468),AmpC酶7株,检出率1.5%(7/468)。产ESBLs大肠埃希菌对二代头孢耐药率大于90%,对三代头孢耐药率为30.4%(头孢他啶)和55.4%(头孢噻肟),对四代头孢(头孢吡肟)耐药率为58.9%,对酶抑制剂联合制剂阿莫西林/克拉维酸和头孢哌酮/舒巴坦的耐药率为92.9%和80.4%,对环丙沙星的耐药率为83%,对庆大霉素的耐药率为73.3%,对四环素的耐药率为88%。产AmpC酶大肠埃希菌表现出更高的耐药性,对二、三代头孢、四环素、环丙沙星和庆大霉素100%耐药,对四代头孢(头孢吡肟)的耐药率达71.4%,对酶抑制剂联合制剂阿莫西林/克拉维酸和头孢哌酮/舒巴坦的耐药率为100%和71.4%,对单环酰胺类的氨曲南耐药率为85.7%。非产ESBLs和AmpC大肠埃希菌的耐药率明显低于产酶者,碳青霉烯类的亚胺培南对所有测试菌株的耐药率为0,MIC50为0.5mg/L。结论(1)对头孢菌素耐药的大肠埃希菌的耐药机制主要是产生ESBLs。(2)产AmpC酶大肠埃希菌比ESBLs耐药更严重,仅亚胺培南对其有效。(3)在临床抗感染治疗中应依据药物敏感试验合理选择抗生素,尽量少选具有诱导细菌产酶的抗生素。     

Campylobacter species and drug resistance in a north Indian rural community

Campylobacter species are known as agents of enteritis worldwide. However, rural community-based studies on Campylobacter infections are lacking. We carried out a prospective case-control study from July to December 2002 to investigate the prevalence and socio-epidemiological determinants of Campylobacter infection in a rural community in north India and the drug resistance of Campylobacter strains isolated from the community. Stool specimens from 348 subjects with diarrhoea and 351 age- and gender-matched asymptomatic controls were cultured for Campylobacter, Salmonella and Shigella. All Campylobacter strains were identified and tested for antibiotic susceptibility. Campylobacter species were isolated from 47 (13.5%) subjects with diarrhoea and 2 (0.6%) asymptomatic controls respectively (P<0.001). Campylobacter infection was significantly higher in children aged less than 5 years, families engaged in agriculture and persons who did not wash their hands with soap after peri-anal washing following defaecation. Campylobacter infections were more frequent than combined Salmonella and Shigella infections (47/348 vs. 15/351; P<0.001) in subjects with diarrhoea. Only two Campylobacter-infected individuals with diarrhoea had bloody stools. Antibiotic resistance of Campylobacter species was as follows: ampicillin 81.6%, ciprofloxacin 71.4%, tetracycline 26.5%, furazolidine 14.3%, gentamicin 10.2% and erythromycin 6.1%; 30.6% of strains were multidrug resistant. Increased quinolone resistance and multidrug resistance pose major risks for treatment failure.     

Increasing antimicrobial resistance of Vibrio cholerae OI biotype E1 tor strains isolated in a tertiary-care centre in India

The antimicrobial susceptibility patterns are on constant change with the recent emergence of multidrug-resistant strains of most bacteria. Results of recent studies in India showed that most isolates of Vibrio cholerae O1 were resistant to the commonly-used antibiotics. The study was conducted to determine the antibiotic susceptibility patterns of V. cholerae O1 isolated during 2008-2010 at the hospital of the Jawaharlal Nehru Institute of Post Graduate Medical Education and Research, Puducherry, India. In total, 154 strains of V. cholerae O1 from 2,658 stool specimens were reported during January 2008-December 2010--34 in 2008, 2 in 2009, and 118 in 2010. The isolates of V. cholerae O1 were subjected to antimicrobial susceptibility testing using the Kirby-Bauer method. The antibiotic disks tested were tetracycline (30 microg), furazolidone (100 microg), ampicillin (10 microg), ceftriaxone (30 microg), and ciprofloxacin (5 microg). Escherichia coli ATCC 25922 was used as the control organism. The minimum inhibitory concentrations (MICs) of ceftriaxone, ciprofloxacin, and tetracycline were determined using the agar dilution method for all the strains. The E-test method was used for the strains which had either intermediate resistance or were resistant to the antibiotics by the agar dilution method. The results of the agar dilution corroborated the results of the E-test. The MIC of ceftriaxone in 151 strains was <2 microg/mL while it was 16 microg/mL in three strains; the latter three strains were resistant to ceftriaxone by the disc-diffusion test. The MIC of ciprofloxacin in 150 strains was <0.5 microg/mL while the MIC of tetracycline was <1 microg/mL. In the remaining four strains, the MIC of tetracycline was >32 microg/mL, and the MIC of ciprofloxacin was >8 microg/mL. These four strains were resistant to both tetracycline and ciprofloxacin by the disc-diffusion test and were exclusive of the three ceftriaxone-resistant strains. The majority of the isolates were obtained from children aged 0-5 year(s)-70.3% (83 of 118) and 41.2% (14 of 34) were reported in 2010 and 2008 respectively. Since treating severe cases of cholera with antibiotics is important, the continuing spread of resistance in V. cholerae to the most important agents of therapy is a matter of concern. Also, chemoprophylaxis with antimicrobial agents is likely to become even more difficult.     

医院感染铜绿假单胞菌的耐药性变迁及临床对策

目的 探讨铜绿假单胞菌(PAE)医院感染的耐药性及其变迁,为临床合理用药提供依据.方法 对医院2008年1月-2010年12月住院患者各种标本中分离到的铜绿假单胞菌175株,采用13种抗菌药物进行药敏试验.结果 痰液中PAE检出率最高占65.7％,其次是脓液标本占17.1％,尿液标本占10.3％;PAE对头孢他啶、头孢吡肟、环丙沙星、左氧氟沙星耐药率均＜20.0％,对头孢噻肟、头孢曲松的耐药率均＞40.0％,最敏感的是阿米卡星、妥布霉素,对亚胺培南/西司他丁的耐药率为21.3％.结论 医院感染铜绿假单胞菌的临床检出率呈逐年上升趋势,且对多种抗菌药物具有耐药性,临床抗感染治疗应根据体外药敏试验结果选用抗菌药物.     

Correlation between electrophoretic types B1 and B2 of carboxylesterase B and sex of patients in Escherichia coli urinary tract infections

One hundred and sixty-eight strains of Escherichia coli isolated from 84 men and 84 women who had urinary tract infections (134 cases) or bacteremia of urinary tract origin (34 cases) were assessed for their carboxylesterase B electrophoretic types B1 and B2, alpha-haemolysin production, the presence of mannose resistant haemagglutinin (MRHA) and antibiotic susceptibility. Electrophoretic type B2 was phenotypically linked with alpha-haemolysin and MRHA productions. The strains isolated from males were more frequently of type B2, haemolytic and both haemolytic and haemagglutinating than those isolated from females. The strains isolated during bacteremia were more frequently haemolytic and haemagglutinating than those obtained from urinary tract infections. Type B1 strains were more frequently resistant to antimicrobial agents than type B2 strains. The results reinforced the distinction, in terms of virulence and antibiotic sensitivity, between B1 and B2 strains and demonstrated the influence of the sex of patients on the host-parasite interaction during urinary tract infections.