In vitro susceptibilities of clinical isolates of Staphylococcus aureus

In vitro susceptibilities of 350 strains of Staphylococcus aureus to ampicillin (ABPC), methicillin (DMPPC), cloxacillin (MCIPC), cefazolin (CEZ), cefmetazole (CMZ), cefmenoxime (CMX), latamoxef (LMOX) and 5 non-beta-lactam antimicrobial agents were determined according to the standard method of Japan Society of Chemotherapy. Frequencies of the appearance of resistant organisms (MIC greater than or equal to 12.5 micrograms/ml) to beta-lactam antibiotics were 45% for ABPC, 27% for DMPPC, 11% for MCIPC, 24% for CEZ, 15% for CMZ, 36% for CMX and 51% for LMOX. To non-beta-lactam antimicrobial agents, resistant strains appeared at 31% to gentamicin, 15% to amikacin, 0.6% to minocycline (MINO), 1% to norfloxacin (NFLX) and 65% to fosfomycin (FOM). More than 80% of DMPPC-resistant strains were also resistant to LMOX, CMX, ABPC, FOM, and CEZ, but most of those were susceptible to MINO and NFLX. Incidence of DMPPC-CEZ resistant S. aureus was 23% of the 350 strains tested. As stated above, multiply resistant strains of S. aureus are present throughout different hospitals in Okinawa.     

In vitro antimicrobial susceptibilities of oxacillin-resistant coagulase negative staphylococci

Minimum inhibitory (broth microdilution) and bactericidal concentrations determined on 101 oxacillin-resistant coagulase-negative staphylococci against netilmicin, oxacillin, vancomycin, Lauricidin and minoxidil. All isolates were susceptible to vancomycin. Netilmicin was the next most active agent, inhibiting 90% of the strains at 8 mcg/ml.     

莫西沙星对224株凝固酶阴性葡萄球菌的体外抗菌活性观察

目的观察莫西沙星对224株表皮葡萄球菌、溶血葡萄球菌和里昂葡萄球菌等凝固酶阴性葡萄球菌（CNS）的体外抗菌活性。方法用二倍琼脂稀释法测定其最低抑菌浓度（MIC）。结果莫西沙星对表皮葡萄球菌、溶血葡萄球菌等CNS的抑菌效果较好，对124株表皮葡萄球菌的MIC50和MIC90分别为≥0．063和0．25μg／ml；对42株溶血葡萄球菌和14株里昂葡萄球菌的MIC90分别为2和0．5μg／ml。结论莫西沙星对表皮葡萄球菌、溶血葡萄球菌、里昂葡萄球菌和人葡萄球菌的抗菌效果好，敏感率分别为96．77％、85．71％、100％和100％；对35株耳葡萄球菌等的敏感率为100％。     

Hospital and district differences in susceptibilities to antibiotics of main clinical isolates

A nationwide survey of susceptibilities of Staphylococcus aureus, Escherichia coli, Klebsiella sp. and Proteus mirabilis initiated in 1980 was continued in 1986. This report documents differences in susceptibilities of clinical isolates of the above microorganisms to ampicillin (ABPC), cefazolin (CEZ), cefmetazole (CMZ) and gentamicin (GM) among general hospitals throughout Japan. Clinical isolates of each species of microorganisms which were collected in 24 hospitals made up each study group and were collected at the Kosei General Hospital, Tokyo, from April 1980 to March 1986. We compared the variability in the resistant rates (MIC greater than or equal to 25 micrograms/ml) and MICs of each antibiotic for 50% and 80% of the isolates among the hospitals. MICs were determined by the serial 2 fold agar plate dilution method, standardized by the Japan Society of Chemotherapy, with an inoculum of approximately 10(6) CFU/ml or 10(8) CFU/ml. Susceptibility patterns of S. aureus to ABPC, CEZ and GM, of E. coli to ABPC, of Klebsiella sp. to CEZ and GM and of P. mirabilis to ABPC, CEZ and GM varied from hospital to hospital. On the other hand, the differences in the susceptibility patterns among the 6 districts of Japan were not obvious, because the differences were affected by different susceptibility patterns of each hospital located in each district.     

In vitro activities of carbapenem antibiotics against the various clinical isolates

The annual changes of antibacterial activities of beta-lactam antibiotics, mainly carbapenem antibiotics, were investigated against 5 bacterial species, S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosa, which had been isolated from the clinical materials at Toho University Omori Hospital during the period of 1995 to 1997. In addition, antibacterial activities against other main bacterial strains isolated from the clinical materials during 1997 were also determined. The five bacterial species on which annual changes of the sensitivity were investigated did not show any remarkable trend to increase in resistance to the carbapenem antibiotics tested. The antibacterial activities of the carbapenem antibiotics against MRSA were weak, and MIC90 values were between 25 and 50 micrograms/ml. In S. marcescens and P. aeruginosa on which high resistance by the production of metallo-beta-lactamase has become a problem in recent years, there were no remarkable changes in annual changes of sensitivities. Especially, MIC90 valuses of the carbapenem antibiotics against P. aeruginosa were between 12.5 and 25 micrograms/ml, 4 to 8 times better than that of PIPC, like the case of CAZ. Furthermore, the carbapenem antibiotics showed strong antibacterial activities against clinically important 16 bacterial species, from Gram-positive to Gram-negative bacteria.     

国产头孢硫脒对224株凝固酶阴性葡萄球菌的体外抗菌活性研究

目的观察头孢硫脒对表皮葡萄球菌、溶血葡萄球菌等凝固酶阴性葡萄球菌的体外抗菌活性。方法采用琼脂稀释法对头孢硫脒进行224株表皮葡萄球菌、溶血葡萄球菌等凝固酶阴性葡萄球菌的最低抑菌浓度(MIC)测定。结果头孢硫脒对100株耐甲氧西林的凝固酶阴性葡萄球菌和124株甲氧西林敏感的凝固酶阴性葡萄球菌的MIC50,MIC90分别为0．5、128、≤0．125和2μg／ml。对甲氧西林敏感的表皮葡萄球菌(MSSE)、溶血葡萄球菌(MSSH)和里昂葡萄球菌(MSSL)的MIC90分别为0．5、2．0和2．0μg／ml。结论头孢硫脒对124株甲氧西林敏感的凝固酶阴性葡萄球菌具有较强的抑菌力。     

致细菌性阴道病的凝固酶阴性葡萄球菌体外抗菌活性分析

目的：研究凝固酶阴性葡萄球菌（CNS）的 耐药性及其与细菌性阴道病的关系。方法：采用高效甘露醇平板进行细菌的分离，肉汤稀释法检测得最小抑菌浓度（MIC）。结果：分离出18株CNS，分离率为42％，对氨苄西林低水平耐药，对克林霉素和洛美沙星中度耐药，对红霉素和大观霉素高度耐药。结论：CNS耐药性的改变，为其致细菌性阴道病的原因之一。     

In vitro activities of levofloxacin and other antibiotics against fresh clinical isolates

In this study, the in vitro activity of levofloxacin (LVFX) against 1,020 fresh bacterial clinical isolates was compared with the activities of a range of ofloxacin, ciprofloxacin (CPFX), ampicillin (ABPC), cefaclor, cefpodoxime, methicillin and benzylpenicillin. The clinical isolates except Vibrio cholerae were collected in Japan during 1998 from patients with infectious diseases. MICs were determined using the agar dilution method according to the recommendations by the Japan Society of Chemotherapy. Some isolates of methicillin resistant Staphylococcus aureus (MRSA) and coagulase negative Staphylococcus were resistant to fluoroquinolones, but the MIC50 of LVFX against MRSA was 6.25 micrograms/ml. LVFX was the most active against MRSA among the antibiotics tested. Most of Staphylococcus epidermidis strains were susceptible to the fluoroquinolones. LVFX showed greater activity against all streptococci strains compared with fluoroquinolones tested. In particular, all Streptococcus pneumoniae strains including PRSP were susceptible to LVFX at < or = 1.56 micrograms/ml. Among Enterococcus, ABPC showed superior activity against Enterococcus faecalis but many isolates of Enterococcus species were resistant to ABPC. LVFX was more active against to these Enterococcus species compared with other fluoroquinolones. On the other hand, LVFX and CPFX showed similar activity against isolates of Enterobacteriaceae. CPFX had an MIC50/90 of 0.20, 0.39 microgram/ml and LVFX showed an MIC50/90 of 0.78, 1.56 micrograms/ml against Pseudomonas aeruginosa. LVFX (MIC50/90 0.10, 0.20 microgram/ml) was more active against Acinetobacter species than CPFX (MIC50/90 0.10, 0.39 microgram/ml). Haemophilus influenzae, Branhamella (Moraxella) catarrhalis and V. cholerae were inhibited by low concentration of the fluoroquinolones tested. The MIC90 of LVFX and CPFX were < or = 0.10 microgram/ml against above three species. Some isolates of Neisseria gonorrhoeae and Campylobacter species were moderately resistant to the fluoroquinolones tested but the MIC50 of LVFX and CPFX were < or = 0.39 microgram/ml. Among anaerobes, Propionibacterium acnes was more susceptible than Peptostreptococcus species, and the MIC90 of beta-lactams and fluoroquinolones tested were < or = 0.78 microgram/ml. In conclusion, this study, performed on large number of strains, confirmed an excellent and wide spectrum antibacterial activity of LVFX compared with the fluoroquinolones and beta-lactams tested. And our results suggest that LVFX may be useful in the treatment of various bacterial infections.     

In vitro activity of daptomycin against clinical isolates with reduced susceptibilities to linezolid and quinupristin/dalfopristin

An initiative was taken to determine the in vitro activity of daptomycin against 85 Gram-positive isolates with reduced susceptibilities to linezolid and quinupristin/dalfopristin. Daptomycin had potent activity against all strains, with a Staphylococcus spp. minimum inhibitory concentration (MIC) < or =2 microg/mL and an Enterococcus spp. MIC < or =8 microg/mL. Resistance to linezolid and quinupristin/dalfopristin appears to be independent of reduced susceptibility to daptomycin.     

4种β-内酰胺类抗生素对临床分离致病菌的体外抗菌活性

目的 对比研究头孢呋辛、头孢克洛、头孢噻肟和阿莫西林等4种β-内酰胺类抗生素对随机选取的临床分离致病菌的体外抗菌活性。方法 随机收集2006-2007年解放军总医院微生物科和空军总医院感染控制科分离的部分临床致病菌，采用琼脂平板稀释法测定最低抑菌浓度（MIC）。结果 头孢呋辛对金葡菌、表葡菌的敏感率分别为45％和83．33％，抗菌活性显著强于头孢克洛，对肺炎克雷伯菌、大肠埃希菌、阴沟肠杆菌及不动杆菌的敏感率分别为38．10％、30．77％、0、0，高于阿莫西林，弱于头孢噻肟。结论 第二代头孢菌素目前对大部分革兰阳性菌仍具有较强的抗菌活性，但对革兰阴性菌的抗菌活性明显弱于第三代头孢菌素。     

In vitro antimicrobial susceptibilities of 349 methicillin-resistant Staphylococcus aureus isolates from veterans

Three hundred and forty-nine methicillin resistant Staphylococcus aureus (MRSA) isolates from veterans were tested (by disc agar diffusion) for their in vitro activity against 18 antimicrobial agents. At least 90% of the isolates were susceptible to bacitracin, nitrofurantoin, hydrogen peroxide, novobiocin, netilmicin and vancomycin. We feel that the aminoglycoside, netilmicin, might provide an alternative agent (to intravenously administered vancomycin) for treating multiply-antimicrobial resistant MRSA. In addition, hydrogen peroxide exhibited very good activity against the test isolates and may have some use as a topical agent for reduction of MRSA on skin and some mucous membranes. This study suggests that further evaluation of netilmicin and hydrogen peroxide (topical only) might be useful.     

6种抗生素对临床分离406株革兰氏阴性杆菌体外抗菌活性比较

１９９３年２月于１９９４年２月，从我院住院患者分离４０６株革兰氏阴性杆菌，细菌鉴定，ＭＩＣ测定由本院微生物实验室Ｖｉｔｅｋ－全自动微生物分析系统完成，统计４种第三代头孢菌素，亚胺培南，环丙沙星的ＭＩＣ５０，ＭＩＣ９０，ＭＩＣｎｏｄｅ，ＭＩＣｒａｎｇｅ，并比较其体外抗菌活性，结果表明：亚胺培南对分离的４０６株革兰氏阴性杆菌显示出强大的体外抗菌活性，头孢他啶，环丙沙星对绿脓假单胞菌依然保持了较强的体外     

In vitro susceptibility of bacterial isolates from patients with respiratory tract infections to beta-lactam antibiotics

In vitro susceptibilities of bacterial pathogens to beta-lactam antibiotics were determined. Bacterial pathogens examined included various isolates from the patients of respiratory tract infections at the hospitals of Kyoto-Shiga area in 1981 and 1983. Major organisms isolated from clinical specimens were Haemophilus spp., Klebsiella spp., Pseudomonas spp., S. aureus and Streptococcus spp. An increase in the isolation frequency of P. aeruginosa, a decrease in the isolation frequency of H. influenzae and no change in the isolation frequency of the other organisms were observed between the years 1981 and 1983. Data from susceptibility tests of clinical isolates confirmed that cefazolin (CEZ) and cefotiam (CTM) showed good antibacterial activity against S. aureus and cefmenoxime (CMX) was highly effective on Streptococcus spp., but that the susceptibilities of both organisms to CEZ, CTM, and cefmetazole (CMZ) in 1983 were lower than in 1981. Although CMX also showed good antibacterial activity against Klebsiella spp., there were no changes in the effectiveness of CTM, CMZ, and CEZ between the years 1981 and 1983. The in vitro antibacterial activities of CMX and cefoperazone against Haemophilus spp. were superior to those of the other beta-lactams tested, but there was a decline in the efficacy for CEZ. Although cefsulodin and piperacillin were highly active against Pseudomonas spp., declines in their effectiveness was observed between the years 1981 and 1983.     

帕珠沙星对临床分离致病菌的体外抗菌活性研究

目的评价帕珠沙星的体外抗菌活性。方法采用琼脂二倍稀释法，测定帕珠沙星与左氧氟沙星对342株临床分离菌株的最低抑菌浓度（MIC）。结果帕珠沙星对革兰阴性菌和革兰阳性菌的MIC90分别为0．06～4和1～16μg／ml。对大肠埃希菌、阴沟肠杆菌、变形菌、铜绿假单胞菌、不动杆菌和链球菌的MIC90为0．06～4μg／ml，是左氧氟沙星的1／2～1／8;对肺炎克雷伯菌、金葡菌和表葡菌与左氧氟沙星抗菌作用相当，MIC90分别为0．5、1、1μg／ml；对流感嗜血杆菌、黏膜炎莫拉菌和粪肠球菌的MIC90为0．5、1、16μg／ml，高于左氧氟沙星（0．25、0．5、8μg／ml）。结论帕珠沙星对革兰阴性菌和革兰阳性菌均具有广谱的抗菌作用，对革兰阴性菌的抗菌活性优于革兰阳性菌。     

In vitro antibacterial activities of carbapenems against clinical isolates

Antibacterial activities of four carbapenems, imipenem, panipenem, meropenem, and biapenem, were determined using 353 strains belonging to 18 bacterial species which were isolated from clinical materials at Ehime University Hospital. The MIC values of these carbapenems against MRSA were widely distributed between 0.1 and 100 micrograms/ml, and MIC90 values of these 4 carbapenems were 25-50 micrograms/ml. Any of these carbapenems prevented the bacterial growth of enterobacteriaceae of 8 bacterial species excluding S. macrescens at concentrations of 1 microgram/ml or less. The MIC values against P. aeruginosa showed relatively wide distribution, being 0.39-25 micrograms/ml for imipenem, 0.2-25 micrograms/ml for panipenem, 0.1-12.5 micrograms/ml for meropenem, and 0.2-12.5 micrograms/ml for biapenem. From those results, it was confirmed that any of the carbapenems tested had a wide antibacterial spectrum and strong antibacterial activities.     

替比培南匹伏脂的体外抗菌作用研究

目的 评价替比培南匹伏脂的体外抗菌作用.方法 用琼脂对倍稀释法测定替比培南匹伏脂对519株临床分离菌的体外抗菌活性.结果 对革兰阳性球菌中的肺炎链球菌、化脓性链球菌及对甲氧西林敏感的金葡菌和凝固酶阴性的葡萄球菌,替比培南匹伏脂均显示良好的抗菌活性.尤其是对青霉素不敏感肺炎链球菌,替比培南匹伏脂的MIC50最低,为0.25 mg·L-1.本品对流感嗜血杆菌、卡他莫拉菌、产ESBLs和不产ESBLs的肺炎克雷伯菌和大肠埃希菌、易产诱导酶的阴沟肠杆菌、产气肠杆菌、枸橼酸杆菌、粘质沙雷菌的MIC50为≤0.03～5.00 mg· L-1,低于其他5种抗菌药物.结论 替比培南匹伏脂对社区感染中常见病原菌有较好的抗菌活性.     

泌尿生殖道沙眼衣原体体外药物敏感性测定

目的　检测泌尿生殖道沙眼衣原体对 6种常用抗菌药米诺环素、阿奇霉素、克拉霉素、司帕沙星、氟罗沙星、左氧氟沙星的药物敏感性。方法　用 Mc Coy细胞培养法 ,以加入抗菌药后沙眼衣原体在细胞内不生长的最低浓度为最小抑菌浓度 (MIC) ,复板后在无抗菌药情况下仍不生长的最低浓度为最小杀菌浓度(MBC)。结果　米诺环素 MIC90 =0 .0 16 mg/ L,MBC90 =0 .0 32 mg/ L;阿奇霉素 MIC90 =0 .5 mg/ L,MBC90 =1.0 mg/ L ;克拉霉素 MIC90 =0 .0 32 mg/ L ,MBC90 =0 .12 8mg/ L ;司帕沙星 MIC90 =0 .0 32 mg/ L ,MBC90 =0 .0 6 3mg/ L ;氟罗沙星 MIC90 =2 .0 mg/ L ,MBC90 =8.0 mg/ L ;左氧氟沙星 MIC90 =0 .5 mg/ L ,MBC90 =2 .0 mg/L。结论　实验中未发现对这 6种抗菌药产生耐药的菌株 ,但氟罗沙星的 MIC90 与 MBC90 已在较高水平。此外 ,米诺环素的抑菌浓度已较以前报道升高。