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 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.     

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.     

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.     

长沙地区1409例泌尿生殖道支原体感染者的感染状况及药敏分析

目的了解长沙地区普通人群泌尿生殖道支原体感染的现状及药敏情况,为临床合理用药提供依据。方法收集并回顾性分析湖南省人民医院1 409例门诊泌尿生殖道感染者的支原体培养鉴定结果及其药物敏感试验结果。结果 1 409例门诊样本中,支原体总阳性率为15.3%(215/1409);其中,解脲脲原体(Uu)和人型支原体(Mh)阳性率为11.5%和6.2%,单独感染Uu、单独感染Mh和混合感染Uu+Mh阳性率分别为9.1%、3.8%和2.4%;女性支原体阳性率为22.3%,明显高于男性的3.3%(χ~2=92.378,P0.01);药物敏感性较高的为强力霉素、美满霉素和交沙霉素,耐药性较高的有喹诺酮类和罗红霉素;女性感染者对交沙霉素和壮观霉素的敏感性高于男性,对其他药物的敏感性则明显低于男性。单独Uu感染者对各抗菌药物(环丙沙星和壮观霉素除外)的敏感性均高于单独Mh感染者,而混合Uu+Mh感染者则为药物敏感性最低的一组(对大部分药物的敏感性低于40%)。结论长沙地区普通人群泌尿生殖道支原体感染的阳性率总体较低,但耐药问题依然突出,临床用药时可把四环素类药物和交沙霉素纳入首选,同时依据感染者的性别、感染类型等选择适宜药物进行治疗。     

Correlation of in vitro and in vivo resistance development to antimicrobial agents

Preclinical in vitro and in vivo determinations of the likelihood of an antibiotic to develop resistance can and has proven predictive of their likelihood of resistance development in patients. Problematic antibiotic/bacterial species combinations are often associated with high frequencies of single-step resistance development in that species. Thus, treatment of organisms with rapid in vitro emergence of drug resistance should be monitored carefully. In vitro studies, however, are limited in predicting resistance mediated through acquisition of a resistance plasmid.The frequency of resistance development to a drug is dependent on factors such as the drug used for selections, the concentration (i.e., dosing) of the drug, the bacterium, and the site of infection. Organisms intrinsically less susceptible to an antibiotic develop resistance rapidly due to their low therapeutic ratios. Since cross-resistance often occurs within an antibiotic class, it may be desirable to initiate therapy with a drug with low resistance-selecting potential. Optimal dosing regimens are especially critical when treating bacterial species likely to develop drug resistance. Though combination drug therapies have proven affective in experimental animal infections and in man, they do not prevent resistant variants from emerging. Understanding of drug-resistance development will contribute to our management of infectious diseases.     

Sensitivity to antimicrobial agents of some mercury-sensitive and mercury-resistant strains of Gram-negative bacteria

The sensitivity and resistance of some Gram-negative mercury (Hg²⁺)-sensitive and-resistant strains to chemotherapeutic agents and to disinfectants and preservatives are described.Escherichia coli andPseudomonas aeruginosa strains harboring plasmid pUB 1351 [pUB 367:Tn 501] andE. coli bearing R100-1 were resistant to inorganic mercury and to various antibiotics, but were not more resistant to organic mercury and other preservatives and disinfectants than plasmidless strains.     

In vitro susceptibilities of Aeromonas genomic species to 69 antimicrobial agents

A total of 217 strains representing all 14 currently described genomic species in the genus Aeromonas were tested for susceptibility to 69 antimicrobial agents by a microdilution method. All species were susceptible to tetracyclines, quinolones, chloramphenicol, and most of the aminoglycosides and the cephalosporins, but were resistant to lincosamides, vancomycin, teicoplanin and some penicillins. In general, no significant differences were found that correlated with the taxonomic designation or the origin of the isolates tested. The microdilution method proved to be easy to perform allowing susceptibility testing of extensive strain collections for a large number of antimicrobial agents.