3类抗菌药物体外抗解脲脲原体和人型支原体的作用

目的比较四环素类、大环内酯类和喹诺酮类3类抗菌药物,对临床分离株解脲脲原体(Uu)和人型支原体(Mh)的抗菌作用,为临床用药提供参考依据.方法采用直接肉汤药盘法测定了临床标本中,195株Uu和1218株Mh对3类抗菌药物中的8种抗生素的敏感性.结果 195株Uu对四环素、多西环素、米诺环素、罗红霉素、阿齐霉素、交沙霉素、氧氟沙星和司帕沙星的敏感率,分别为21.0%、48.2%、39.5%、79.0%、88.7%、74.9%、28.2%和64.6%.118株Mh对四环素、多西环素、米诺环素、罗红霉素、阿齐霉素、交沙霉素、氧氟沙星、司帕沙星的敏感率分别为5.1%、33.9%、26.3%、0.0%、0.0%、89.8%、70.3%和64.4%.960例混合感染的Uu Mh,对交沙霉素最敏感(79.2%).结论泌尿生殖道支原体的药敏监测对指导临床治疗具有重要意义.     

Bacterial conjugation-based antimicrobial agents

A clear imperative exists to generate radically different antibacterial technologies that will reduce the usage of conventional chemical antibiotics. Here we trace one route into this new frontier of drug discovery, a concept that we call the bacterial conjugation-based technologies (BCBT). One of the objectives of the BCBT is to exploit plasmid biology for combating the rising tide of antibiotic-resistant bacteria. Specifically, the concept utilizes conjugationally delivered plasmids as antimicrobial agents, and it builds on the accumulated work of many scientists dating back to the discoveries of conjugation and plasmids themselves. Each of the individual components that comprise the approach has been demonstrated to be feasible. We discuss the properties of bacterial plasmids to be employed in BCBT.     

Sensitivity of environmental microorganisms to antimicrobial agents.

The sensitivity of different microorganisms, considered as typical representatives of the microflora of soil and water, was established to evaluate the influence of the nonmedical use of antimicrobial agents on bacterial ecology. Only seven strains, six chemoorganotrophs and one chemolithotroph, could be considered as relatively sensitive to the 21 antimicrobial compounds tested. The other 29 microorganisms may be regarded as resistant to most antimicrobial agents. Streptomyces were sensitive to high concentrations of active substances. Broad-spectrum antibiotics showed an effect on environmental bacteria similar to that on human pathogens. Cephalothin stimulated the growth of a Chlorella sp. From these experiments, it appears that spilled antimicrobial agents have little chance of causing an alteration in the microbial ecology.     

Sensitivity of scopulariopsis brevicaulis to some antimicrobial agents

Sensitivity tests were done against two isolates of Scopulariopsis brevicaulis, using amphotericin B in combination with chloramphenicol, Chloramphenicol alone, amphotericin B in combination with 5-fluorocytosine, and 5-fluorocytosine, myxin and clotrimazole alone. Results indicated that the effectiveness of amphotericin B was improved in the presence of chloramphenicol or 5-fluorocytosine. Growth inhibitory values recorded for chloramphenicol alone and combined with amphotericin B did not show much variation. Resistance of the fungus has been noticed to 5-fluorocytosine; but the organism's response was much better when tested against 5-fluorocytosine in the presence of amphotericin B. Both myxin and clotrimazole proved very effective and their ED50 was 50 and 2.5 ug/ml of the medium, respectively. Thus, clotrimazole may be the drug of choice in the cases of deep scopulariopsis.     

In vitro activity of three different antimicrobial agents against ESBL producing Escherichia coli and Klebsiella pneumoniae blood isolates

Extended spectrum beta-lactamases (ESBLs) usually associated with multiple drug resistance, including beta-lactam and non-beta-lactam antibiotics. This resistance can cause Limitation in the choice of drugs appropriate for using in clinical practice, especially in life-threatening infections. In this study we aimed to investigate in vitro activity of meropenem, ciprofloxacine and amikacin against ESBL-producing and non-producing blood isolates of Escherichia coli and Klebsiella pneumoniae strains. Fifty-eight E. coli (21 ESBL-producing, 37 non-ESBL producing) and 99 K. pneumoniae (54 ESBL-producing, 45 non-ESBL producing) strains were included in the study. The presence of ESBL was investigated by double disk synergy test and E-test methods. Antibiotic susceptibility test was done by microdilution method according to NCCLS guideline. In vitro susceptibilities of ESBL producing E. coli and K. pneumoniae strains were found as 100% for meropenem, 33.3% and 25.9% for ciprofloxacine, 94.5% and 83.3% for amikacin. It was observed that; meropenem was equally active agent in both ESBL-producing and non-producing strains, and its activity was not affected by ESBL production. Whereas amikacin activity was minimally affected and ciprofloxacine activity was markedly decreased by ESBL production. In conclusion, meropenem seems to be better choice of antibiotic should be used for ESBL positive life-threatening infections, because of remaining highest activity.     

In vitro susceptibility of staphylococci to linezolid and other antimicrobial agents

Linezolid is a member of the new class of antibacterial agents called oxazolidinones that are active against Gram positive organisms and exert their action by protein synthesis inhibition. In this study we investigated the in vitro activity of linezolid versus the other agent against clinical strains of staphylococci: Staphylococcus aureus (n = 82) and S. epidermidis (n = 32) collected in 2002 from hospitalized patients and healthy individuals, isolated from different biological samples. Agar dilution minimum inhibitory concentrations (MICs) were determined by using Mueller-Hinton agar according to the guidelines established by the National Committee for Clinical Laboratory Standards. Linezolid demonstrated excellent in vitro activity against all isolates tested, with MICs values in the range of susceptibility (< or = 8 microg/ml). No associated resistance between linezolid and other agents tested was observed. The resistance among Gram positive bacteria continues to spread and for many patients infected with these resistant organisms antimicrobial therapy is ineffective and linezolid may be a new alternative treatment.     

STD患者及性高危人群泌尿生殖道支原体感染状况研究

目的:探讨泌尿生殖道支原体在STD患者及性高危人群中的感染状况.方法:采用培养法对421例STD患者、84例性乱者和185例性病伴侣进行解脲脲原体(Uu)和人型支原体(Mh)的检测.结果:STD患者、性乱者和性病伴侣泌尿生殖道支原体感染率分别为42.28%、35.71%和40.0%,与健康人群(13.48%)比较,差异有显著性(x2=56.61、19.44、38.16,P＜0.005).前三者之间比较,差异无显著性(x2=1.25、0.28、0.45,P＞0.05).Uu感染率(15.22%)与Mh(5.22%)比较,前者明显高于后者(x2=37.61,P＜0.005).男性Uu和Mh感染率(分别为8.57%、2.08%)与女性(分别为23.61%、9.18%)比较,女性明显高于男性(x2=29.82、17.36,P＜0.005).Uu和Mh混合感染率(20.43%)明显高于Uu(15.22%)或Mh(5.22%)的单独感染率(x2=6.41、71.45,P值分别为P＜0.05、P＜0.005).结论:Uu和Mh在STD患者、性乱者和性病伴侣中流行、感染率高,在性病的防治和监测工作中应加以重视.     

聚合酶链反应在牛血清支原体检测中的应用

为了探讨聚合酶链反应在牛血清支原体检测上的应用价值,以支原体高度保守的rRNA操纵子(支原体基因组中16SrRNA的编码区序列)设计引物,采用碱裂解法提取牛血清中支原体DNA作为模板进行聚合酶链反应。结果表明,阳性、阴性和内控对照都扩增出了预期的条带,聚合酶链反应与支原体培养法比较,有灵敏、快速、特异性高的特点,可用于牛血清中支原体的常规检测。