134株嗜血杆菌体外抗菌药物敏感性分析

目的　了解临床分离的嗜血杆菌对头孢噻肟等 1 7种抗菌药物的抗菌活性状况 ,指导临床合理用药控制嗜血杆菌的流行。方法　对从临床痰液标本分离出的 1 34株嗜血杆菌进行头孢噻肟等 1 7种抗菌药物的药敏试验和 β 内酰胺酶试验 ,利用WHONET4软件对试验数据进行处理和分析。 结果　在被检测的 5 0 0份标本中 ,分离到 1 34株嗜血杆菌 (35 % ) ,其中副流感嗜血杆菌 71株 ,流感嗜血杆菌 6 3株。研究发现流感嗜血杆菌对头孢噻肟的敏感性最高 ,为 1 0 0 % ,其次为阿莫西林 /克拉维酸 ,敏感性为 95 .2 %。 1 34株嗜血杆菌对复方磺胺甲唑、甲氧苄氨嘧啶都表现了较高的耐药性 ,耐药率 >6 5 % ,对喹诺酮类抗生素耐药率也较高。结论　治疗嗜血杆菌感染的最有效药物为头孢噻肟 ,其次为阿莫西林 /克拉维酸。     

湖北省随州市健康人群嗜血杆菌带菌率及其药物敏感性分析

目的了解湖北省随州市健康人群嗜血杆菌的带菌率和抗生素敏感性。方法分别于2011年和2016年采集湖北省随州市健康人群咽拭子，进行嗜血杆菌的分离培养，并采用玻片凝集和荧光PCR方法对流感嗜血杆菌（Hi）进行血清型和基因型鉴定。 采用K-B纸片扩散法对所有菌株进行体外药物敏感性试验。结果2011年和2016年湖北省随州市Hi、溶血嗜血杆菌（Hh）和副流感嗜血杆菌（Hp）的阳性检出率分别为11.90%、4.76%、2.86%和14.76%、13.81%、3.33%。 Hi对氨苄西林、头孢克洛、头孢克肟、阿奇霉素、阿莫西林/克拉维酸、环丙沙星和美罗培南的敏感率分别为35.71%、57.14%、83.93%、83.93%、87.50%、96.43%、96.43%，Hh的敏感率为41.03%、56.41%、94.87%、94.87%、76.92%、97.44%、92.31%，Hp 的敏感率为53.85%、76.92%、84.62%、100%、76.92%、53.85%、76.92%。 仅Hi和Hp对美罗培南（P＝0.015）和环丙沙星（P＜0.001）敏感性差异有统计学意义，其他差异均无统计学意义（P＞0.050）。 与2011年相比，2016年Hi对氨苄西林（P＝0.025）、头孢克洛（P＝0.044）、头孢克肟（P＝0.027）和阿奇霉素（P＝0.003）敏感性下降，差异具有统计学意义；Hh仅对阿莫西林/克拉维酸（P＝0.045）和阿奇霉素（P＝0.013）敏感性下降，差异具有统计学意义；Hp对7种抗生素差异均无统计学意义。结论不同嗜血杆菌对抗生素的敏感性存在差异。 随着时间推移，嗜血杆菌对部分抗生素的敏感性明显降低。     

732株嗜血杆菌对阿奇霉素敏感性分析

1999年 3月至 2 0 0 0年 12月 ,对南京军区南京总医院住院病人 ,门诊病人送检的痰液及咽拭标本中分离的 732株嗜血杆菌 ,采用Ｋ Ｂ纸片扩散法 ,对阿奇霉素做了药敏试验 ,并与其他 5种抗菌药物作了比较 ,报告如下。1　材料与方法1 1　菌种嗜血杆菌 732株 ,其中流感嗜血杆菌 30 2株 ,占41 3% ;副流感嗜血杆菌 430株 ,占 5 8 7%。1 2　培养基　巧克力培养基按《全国临床检验操作规程》(1997年第 2版 )由本室自制 ;血琼脂和Ｍ Ｈ琼脂 (Ｏｘｏｉｄ)作鉴定用 ;ＨＴＭ培养基 (Ｏｘｏｉｄ)作药敏用。1 3　药敏纸片　阿奇霉素、头孢噻肟、头孢呋辛、…     

51株克雷伯菌对常用抗菌药物敏感性分析

克雷伯杆菌是常见的机会致病菌，可引起典型的原发性肺炎，在正常人口咽部带菌率为1—6％，但在住院病人中可达20％，为医院感染的重要病原体之一。近年来，由该菌引起的免疫低下患者感染或医院感染不断增加，其对抗生素的耐药性也不断增加，为提高对该菌的耐药性认识，本人收集了51株克雷伯杆菌，测试其对14种抗生素的敏感性，以了解其耐药性。     

脑膜败血黄杆菌64株体外药物敏感性分析

目的:分析脑膜败血黄杆菌临床药物敏感性特点,指导临床合理选用抗生素.方法:采用ATB全自动鉴定及药敏测试仪测定脑膜败血黄杆菌及其药物敏感性.结果:药物敏感检测表明脑膜败血黄杆菌对哌拉西林一三唑巴坦(敏感率为96.9%)和哌拉西林(敏感率为79.7%)敏感,对其它抗生素普遍耐药.结论:脑膜败血黄杆菌耐药现象严重,治疗可选择哌拉西林一三唑巴坦、哌拉西林等抗生素.     

195株鲍曼不动杆菌的临床分布及药物敏感性分析

目的了解南京医科大学附属苏州市立医院临床分离的鲍曼不动杆菌属对15种抗菌药物的耐药性,为临床抗菌药物的选择和控制感染提供依据。方法收集南京医科大学附属苏州市立医院2009年10月至2010年11月所有临床分离的鲍曼不动杆菌,鉴定采用法国生物梅里埃公司ATB细菌鉴定仪,根据美国临床实验室标准化协会推荐的纸片扩散法做体外药敏试验。结果 195株鲍曼不动杆菌对米诺环素最为敏感,敏感率为80.5%,其次是美罗培南、亚胺培南和头孢哌酮/舒巴坦的敏感率分别为65.1%、63.6%和56.9%,对哌拉西林、庆大霉素、复方新诺明、环丙沙星、左氧氟沙星的耐药率分别为61.5%、59.0%、57.4%、51.8%和50.3%。结论鲍曼不动杆菌是医院感染的重要病原菌,耐药率高,部分菌株呈多重耐药,应根据药敏试验结果合理选用抗菌药物。     

鲍曼不动杆菌对常用抗菌药物的敏感性

目的 :测定自下呼吸道分离的鲍曼不动杆菌对常用抗菌药物敏感性。方法 :自下呼吸道分离的鲍曼不动杆菌 4 0株 ,采用ATB全自动鉴定及药敏测试仪测定此菌的体外药物敏感性。结果 :药敏监测表明此菌广泛耐药 ,敏感率 >5 0 %的抗生素仅有 :亚胺培南 ( 92 % )、哌拉西林 /三唑巴坦 ( 63 % )、头孢他啶 ( 5 5 % )、哌拉西林 ( 5 3 % )。结论 :下呼吸道感染中分离的鲍曼不动杆菌 ,耐药现象严重 ,抗菌药物的选择有赖于细菌培养和药物敏感结果     

重症监护病房鲍曼不动杆菌21株抗菌药物敏感性分析

目的 :了解重症监护病房 (ICU)鲍曼不动杆菌肺炎药物敏感性特点 ,为临床防治提供指导。方法 :鲍曼不动杆菌的分离和鉴定用ATB细菌鉴定仪 ,以琼脂稀释法对分离菌株进行药物敏感性测定。结果 :对于本次试验的 2 1株鲍曼不动杆菌 ,亚胺培南的抗菌活性最强 ,敏感率为 90 % ,其次是头孢哌酮 舒巴坦 ,敏感率为 81% ;阿米卡星、头孢吡肟、头孢他啶的敏感率在6 0 %左右 ;细菌对于头孢唑林及氨苄西林的敏感率 <5 %。结论 :ICU鲍曼不动杆菌肺炎经验治疗可选用亚胺培南、头孢哌酮 舒巴坦。合理应用抗生素及做好消毒隔离 ,规范操作等措施可有效防治ICU鲍曼不动杆菌肺炎     

196株阴沟肠杆菌对抗菌药物的敏感性分析

目的了解全身感染和尿液感染的阴沟肠杆菌对抗菌药物的敏感性,为临床提供治疗依据。方法采用微量稀释法对196株临床送检的血液、尿液及其他标本分离的阴沟肠杆菌进行药敏试验,测定其最低抑菌浓度值。结果阴沟肠杆菌对亚胺培南的敏感率为96.9%,对哌拉西林/他唑巴坦、左氧氟沙星、环丙沙星、庆大霉素、妥布霉素的敏感率为60%～80%,对头孢他啶、氨曲南、头孢曲松、哌拉西林的敏感率为40%～60%,对氨苄西林/舒巴坦的敏感率为14.3%,对氨苄西林和头孢唑啉的敏感率仅为3.6%和1.5%;分离自尿液的阴沟肠杆菌对氨苄西林/舒巴坦、头孢唑啉的敏感性高于血液分离菌,分离自尿液的阴沟肠杆菌对氨苄西林、头孢他啶、头孢曲松、环丙沙星、庆大霉素、亚胺培南、左氧氟沙星、氨曲南、哌拉西林、哌拉西林/他唑巴坦、妥布霉素的敏感性低于血液分离菌。结论阴沟肠杆菌对不同的抗菌药物的敏感性差异较大,治疗时应根据耐药特点及菌种间的耐药性差异选择相应的药物和方案,目前亚胺培南仍然是治疗阴沟肠杆菌感染的有效药物。     

基层医院嗜血杆菌检测方法及耐药性的研究应用

正嗜血杆菌引起人类机会性感染致病越来越受到临床关注,主要有流感嗜血杆菌(haemophilus influenzae,HI)和副流感嗜血杆菌(hemophilus parainfluenzae,HPI),国内对嗜血杆菌研究也有60年历史。嗜血杆菌初次培养对营养要求高,在血平板上不生长或易被革兰阳性球菌抑制,不易培养。在基层医院由于缺乏可培养菌的分离培养条件,如专用培养基、CO_2环境、     

阿奇霉素非敏感嗜血杆菌的分离及其药敏试验观察

目的 了解2008～2011年阿奇霉素非敏感嗜血杆菌的分离情况及药敏试验特点,为临床治疗提供依据.方法 统计分析2008～2011年本院临床送检呼吸道标本阿奇霉素非敏感嗜血杆菌分离情况,分析其对常用抗菌药物的药敏试验结果,并与阿奇霉素敏感菌株进行对比观察.结果 22 986份呼吸道标本,分离嗜血杆菌1 900株,其中阿奇霉素非敏感菌株共计389株,分离率为21.48%,4年间呈逐年上升趋势;阿奇霉素非敏感嗜血杆菌菌株构成以副流感嗜血杆菌为主,占79.18%,而流感嗜血杆菌只占20.82%.阿奇霉素非敏感流感嗜血杆菌对阿莫西林/克拉维酸、氨苄西林/舒巴坦、头孢呋辛3种抗菌药物的耐药率高于副流感嗜血杆菌,且两种嗜血杆菌对头孢曲松、头孢泊肟、氨曲南、美罗培南和左氧氟沙星均表现敏感性降低.2008～2011年间阿奇霉素非敏感嗜血杆菌对氨苄西林耐药率逐年增高;与敏感菌株相比,流感嗜血杆菌非敏感株对氨苄西林、氨苄西林/舒巴坦、头孢曲松、氨曲南、左氧氟沙星耐药率或非敏感率显著增高;而对于副流感嗜血杆菌,非敏感菌株对试验药物耐药率或非敏感率均显著增高.结论 嗜血杆菌阿奇霉素非敏感菌株逐年增加,其对常用抗菌药物的耐药率或非敏感率均高于阿奇霉素敏感株.     

Tolerance of Haemophilus influenzae to beta-lactam antibiotics.

Two hundred clinical isolates of Haemophilus influenzae were tested for tolerance (MBC/MIC greater than or equal to 32) to ampicillin and cefotaxime by broth dilution tests. Of 200 strains, 9 were tolerant to ampicillin, and 10 were tolerant to cefotaxime. Tolerant organisms were identified in both systemic and nonsystemic infections and among different biotypes and serotypes of H. influenzae. These tolerant isolates were compared with nontolerant isolates by broth dilution and killing curves with log-phase and stationary-phase inocula. Both tolerant and nontolerant bacteria in log phase were killed more rapidly by antibiotics than bacteria in stationary-phase growth. When tested against 11 different beta-lactams, several patterns of tolerance were observed. Six of the ten strains were tolerant to aztreonam, four were tolerant to cefuroxime, three were tolerant to cefamandole, and two were tolerant to cefoxitin. Strain H130 was tolerant to all beta-lactam antibiotics studied. None of the 10 tolerant H. influenzae isolates were tolerant to chloramphenicol, rifampin, tobramycin, ciprofloxacin, enoxacin, and trimethoprim-sulfamethoxazole. Although the clinical significance of tolerance is not determined, this study suggests that the bactericidal activity (MBC) of beta-lactam antibiotics against H. influenzae should be determined in cases of severe infections in which clinical response is slow or unsatisfactory.     

In vitro susceptibility of Haemophilus influenzae to eight antibiotics

Freshly isolated strains of Haemophilus influenzae type B were studied for their in vitro susceptibility to eight antibiotics with a low concentration inoculum. No organisms were identified as being resistant to ampicillin, but minimal inhibiting concentrations for that antibiotic were somewhat higher than reported previously for a similar method. Carbenicillin and ticarcillin resembled ampicillin in activity, and the three agents were more effective on a weight basis than the other agents tested.     

Susceptibility of Haemophilus influenzae to chloramphenicol and eight beta-lactam antibiotics

We examined the minimal inhibitory concentrations and minimal bactericidal concentrations of chloramphenicol, ampicillin, ticarcillin, cefamandole, cefazolin, cefoxitin, cefotaxime, ceforanide, and moxalactam for 100 isolates of Haemophilus influenzae, 25 of which produced beta-lactamase. Susceptibility was not influenced by the capsular characteristic of the organism. The mean minimal inhibitory concentrations of cefamandole, ticarcillin, and ampicillin for beta-lactamase-producing strains were 3-, 120-, and 400-fold higher than their respective mean minimal inhibitory concentrations for beta-lactamase-negative strains. No such difference was noted for the other antibiotics. We performed time-kill curve studies, using chloramphenicol, ampicillin, cefamandole, cefotaxime, and moxalactam with two concentrations of the antimicrobial agents (4 or 20 times the minimal inhibitory concentrations) and two inoculum sizes (10(4) or 10(6) colony-forming units per ml). The inoculum size had no appreciable effect on the rate of killing of beta-lactamase-negative strains. The rates at which beta-lactamase-producing strains were killed by chloramphenicol, cefotaxime, and moxalactam was not influenced by the inoculum size. Whereas cefamandole in high concentrations was able to kill at 10(6) colony-forming units/ml of inoculum, it had only a temporary inhibiting effect at low drug concentrations. Methicillin and the beta-lactamase inhibitor CP-45,899 were able to neutralize the inactivation of cefamandole by a large inoculum of beta-lactamase-producing H. influenzae.     

Comparative susceptibilities of ampicillin and chloramphenicol resistant Haemophilus influenzae to fifteen antibiotics

Eighty-three isolates of ampicillin and chloramphenicol resistant Haemophilus influenzae were tested for susceptibility to fifteen antibiotics by the agar dilution method. Fifty-four were from paediatric patients with H. influenzae disease and 29 from nasopharyngeal carriers (pre-school children). Twenty-five strains belonged to serotype b, one to serotype a, one to serotype c and the rest were non-typable. All strains produced beta-lactamase and inactivated chloramphenicol in a rapid bioassay, suggesting the production of chloramphenicol-acetyltransferase. The most active drugs were ceftriaxone, cefotaxime, latamoxef, aztreonam and desacetyl-cefotaxime (MIC90: 0.03, 0.06, 0.12, 0.25 and 0.25 mg/l, respectively). Cefuroxime, rifampicin and imipenem (MIC90 1 mg/l), and the combination of amoxycillin and clavulanic acid (MIC90 2:1 mg/l), also showed good activity. Cefaclor, erythromycin, tetracycline, trimethoprim, sulfamethoxazole and cotrimoxazole were the least active of the drugs studied. The excellent in-vitro activity of the new beta-lactam agents against H. influenzae resistant to ampicillin and chloramphenicol offers a therapeutic alternative in the treatment of serious infections caused by these micro-organisms.     

Susceptibility of Pseudomonas species to the novel antibiotics mureidomycins.

Strains of Pseudomonas aeruginosa, including imipenem- or ofloxacin-resistant clinical isolates, and some other species in the genus Pseudomonas were inhibited by novel antibiotics of the mureidomycin (MRD) group. On the other hand, almost all other gram-positive and gram-negative bacteria were resistant to MRDs, though the antibiotics potently inhibited the in vitro peptidoglycan synthesis of Escherichia coli and P. aeruginosa. All of the strains in the genus Pseudomonas that were inhibited by less than or equal to 200 micrograms of MRDs per ml were classified into the rRNA groups I and III, and none of the tested strains of rRNA group I were resistant to MRDs, suggesting that these two groups are closely related to each other evolutionary. Among group I strains, P. aeruginosa, P. mendocina, P. stutzeri, and P. alcaligenes were more susceptible than the others, suggesting a closer relationship among these species.     

Effect of inoculum size on the susceptibility of Haemophilus influenzae b to beta-lactam antibiotics.

The current prevalence of ampicillin-resistant Haemophilus influenzae b meningitis requires accurate knowledge of susceptibility to alternative antibiotics. One variable affecting susceptibility is inoculum size. We studied the susceptibility of 200 clinical isolates of H. influenzae b to ampicillin, carbenicillin, and cefamandole at inocula of 10(5) and 10(7) CFU by two techniques. Fifty ampicillin-susceptible and fifty ampicillin-resistant strains were tested for susceptibility to ampicillin by broth dilution while 100 of each were tested by agar dilution. An inoculum effect was found, being greatest with the ampicillin-resistant strains. The range of minimal inhibitory concentrations for the resistant strains was 25 to 800 microgram of ampicillin per ml at an inoculum of 10(5) and 2,000 to less than 6,000 microgram of ampicillin at 10(7); 1.0 to 150 microgram of carbenicillin per ml at 10(5) and 6.2 to 2,000 microgram of carbenicillin per ml at 10(7); 0.4 to 2.0 microgram of cefamandole at 10(5) and 1.0 to 125 microgram/ml at 10(7). Because of this inoculum effect, we would not recommend the use of carbenicillin or cefamandole for therapy of ampicillin-resistant H. influenzae meningitis.     

Beta-lactamase-positive strains of Haemophilus influenzae: susceptibility to and inactivation of beta-lactam antibiotics

Susceptibility and time-kill studies were done with low and high inocula of both beta-lactamase-positive and -negative strains of Haemophilus influenzae with cefamandole, ampicillin, cefoperazone, mezlocillin, moxalactam, and ceftriaxone. Bioassay was done to test for antibiotic inactivation by beta-lactamase-positive strains. All six antibiotics were highly active against the low inoculum (10(4) to 10(5) colony-forming units/ml) of beta-lactamase-negative strains; ceftriaxone, moxalactam, and cefoperazone were equally active against the same inoculum concentration of beta-lactamase-positive strains. In contrast, cefamandole, mezlocillin, and ampicillin were less active against the low inoculum of beta-lactamase-positive H influenzae. A marked inoculum effect occurred with the high inoculum (10(7) to 10(8) CFU/ml) with all six antibiotics, regardless of beta-lactamase production. In time-kill studies, marked differences in bacterial killing resulted after low and high inocula. Ampicillin, cefamandole, cefoperazone, and mezlocillin were rapidly inactivated by the high inoculum of beta-lactamase-positive H influenzae.     

Comparative activities of antibiotics against intracellular non-typeable Haemophilus influenzae

INTRODUCTION: Non-typeable Haemophilus influenzae (NTHi) is a major bacterial pathogen of community-acquired respiratory tract infection and is usually found extracellularly, although studies have revealed that NTHi may possess the ability to invade human epithelial cells where it is then protected against attack by the local immune system and partly against the effect of antibiotics. The aim of the present study was to assess the ability of ampicillin, azithromycin, telithromycin, ciprofloxacin and moxifloxacin, five antibiotics in common clinical use, to kill NTHi within bronchial epithelial cells. METHODS: Confluent human bronchial epithelial cells were infected with NTHi 77, a particularly invasive clinical strain. Extracellular bacterial cells were killed with gentamicin and the intracellular bacteria were incubated with antibiotics at concentrations of 1 mg/l or 10 mg/l for 4 h or 8 h. Viable intracellular bacteria were counted after lysis of the epithelial cells. RESULTS: With the exception of ampicillin, all the antibiotics caused significant reduction of intracellular bacteria at concentrations of 10 mg/l and exposure for 4 h or at 1 mg/l for 8 h. At 1 mg/l, moxifloxacin eliminated 94% of intracellular NTHi after 4 h and 98% after 8 h; ciprofloxacin, azithromycin and telithromycin only achieved killing indices below 75 after 4 h but 86-90% killing after 8 h. At 10 mg/l, moxifloxacin, ciprofloxacin, telithromycin and azithromycin were able to achieve 99.7%, 96.3%, 86.7% and 74.7% eradication of intracellular bacteria, respectively, after exposure for 4 h. CONCLUSION: These results demonstrate the rapid antibacterial efficacy of moxifloxacin against intracellular NTHi in vitro. Moxifloxacin, which combines high extracellular and intracellular activities, could be an important tool in the treatment of recurrent respiratory tract infections.