Activity of moxifloxacin against clinical isolates of Streptococcus pneumoniae from England and Wales

The activity of moxifloxacin was assessed against 1269 isolates of Streptococcus pneumoniae, comprising 462 isolates referred from UK hospitals, primarily for confirmation of resistance to first line agents, and 807 isolates from an enhanced surveillance of invasive infections. Resistance rates to penicillin, erythromycin, tetracycline and chloramphenicol were 88.7% (32.6% intermediate and 56.1% fully resistant), 50, 48 and 22.7%, respectively, for the former, and 8.0 (4.5% intermediate and 3.5% fully resistant), 14.7, 9.0 and 0.6% for the latter. Ninety-four per cent of the referred isolates and 99% of the surveillance isolates were susceptible to moxifloxacin at 相似文献   

Activity of oral agents against pediatric isolates of Streptococcus pneumoniae

An in vitro study of the activity of 10 oral agents against 153 pediatric isolates of Streptococcus pneumoniae identified moxifloxacin and levofloxacin as the most active agents regardless of penicillin or macrolide susceptibility. Moxifloxacin inhibited all strains at 0.25 microg/ml and was 8- to 16-fold more potent than levofloxacin.     

In-vitro activity of 29 antimicrobial agents against penicillin-resistant and -intermediate isolates of Streptococcus pneumoniae.

Antibiotic resistance among isolates of Streptococcus pneumoniae is increasing worldwide. Optimal therapy, though unknown, should be guided by in-vitro susceptibility testing. Currently, vancomycin is the only approved antibiotic that is universally active against multiresistant S. pneumoniae. In-vitro activities were determined for 29 antimicrobial agents against 22 penicillin-intermediate S. pneumoniae (PISP) and 16 penicillin-resistant S. pneumoniae (PRSP) isolates. MICs were determined in cation-adjusted Mueller-Hinton broth with 3% lysed horse blood in microtitre trays. Antimicrobial classes tested included cephalosporins, penicillin, aminopenicillins, macrolides, quinolones, carbapenems and other antimicrobial agents. Among the classes of antimicrobial agents tested, wide differences in susceptibility were demonstrated for both PISP and PRSP. Of the cephalosporins, ceftriaxone and cefotaxime demonstrated the best in-vitro activity for both PISP and PRSP. Of the quinolones, clinafloxacin and trovafloxacin showed the greatest in-vitro activity. Rifampicin and teicoplanin demonstrated excellent in-vitro activity. Promising in-vitro results of newer agents, such as quinupristin/dalfopristin, ramoplanin, teicoplanin and linezolid may justify further evaluation of these agents in clinical trials.     

Moxifloxacin: a comparison with other antimicrobial agents of in-vitro activity against Streptococcus pneumoniae

Two hundred representative isolates, including 26 strains of Streptococcus pneumoniae with intermediate resistance to penicillin, were selected from a collection obtained from blood cultures of patients with bacteraemic pneumococcal pneumonia. The MICs of moxifloxacin (BAY 12-8039), grepafloxacin, sparfloxacin, levofloxacin, ofloxacin, ciprofloxacin, erythromycin, tetracycline and penicillin G were determined by a standard agar dilution technique. Moxifloxacin had the highest in-vitro activity against S. pneumoniae (MIC90 = 0.25 mg/L; MIC range 0.06-0.25 mg/L). The MIC90 values were one dilution lower than those obtained with sparfloxacin and grepafloxacin, three dilutions lower than those obtained with levofloxacin, and four dilutions lower than those of ofloxacin and ciprofloxacin.     

莫西沙星等13种抗菌药物对呼吸道常见感染致病菌体外抗菌活性的研究

目的比较莫西沙星与其他12种抗菌药物对临床常见致病菌的体外抗菌活性。方法采用琼脂稀释法测定对411株临床分离菌株的最低抑菌浓度。结果金黄色葡萄球菌(MRSA)和肺炎链球菌(包括PISP和PRSP)对万古霉素的敏感性最高，敏感率为95．8％-100％，对莫西沙星、加替沙星的敏感性较高，对大环内酯类药物则比较耐药。流感嗜血杆菌、卡他莫拉菌对莫西沙星、加替沙星等4种氟喹诺酮类和5种头孢菌素类及阿奇霉素比较敏感。肺炎克雷伯菌(包括产ESBL菌株)对莫西沙星等4种氟喹诺酮类和头孢美唑很敏感；非产ESBL菌株对8种抗菌药物均敏感，但产ESBL菌株对第二、三代头孢菌素则显示了较高的耐药率。大肠埃希菌(包括产ESBLs菌株)对氟喹诺酮类敏感率在40％左右，非产ESBL菌株对5种头孢菌素均较敏感，但产ESBL菌株除对头孢美唑敏感外，对其他头孢菌素类耐药率较高。结论莫西沙星与其他12种抗菌药物比较，对革兰阳性菌作用增强，对肺炎克雷伯菌(包括产ESBL菌株)抗菌活性较强，大肠埃希菌对莫西沙星与其他氟喹诺酮类有一定的交叉耐药性。     

Comparative in vitro activities of carbapenem antimicrobial agents against 264 penicillin-resistant Streptococcus pneumoniae isolates from Korea

We compared in vitro activities of carbapenems against 264 penicillin-resistant Streptococcus pneumoniae (PRSP) isolates. The MIC(50)/MIC(90) (microg/mL) values of imipenem, meropenem, ertapenem, and panipenem were 1/1, 0.25/0.25, 0.25/0.5, and 0.125/0.25, respectively. The susceptibility rates to imipenem, meropenem, and ertapenem were 0%, 85.2%, and 99.6%, respectively. Compared with imipenem and meropenem, ertapenem and panipenem had better in vitro activities against PRSP.     

Activity of faropenem against resistant isolates of Streptococcus pneumoniae.

An in vitro study of the activity of 9 agents against 181 US pediatric isolates of Streptococcus pneumoniae identified imipenem and faropenem as the most active agents. Overall, faropenem was the most potent oral agent inhibiting 98% of isolates at 1 microg/mL.     

In vitro activities of retapamulin and 16 other antimicrobial agents against recently obtained Streptococcus pyogenes isolates

Retapamulin in vitro activity against 400 Streptococcus pyogenes clinical isolates obtained from skin, pharynx, ear fluid, and blood samples recovered from 2007 to 2009 was studied. The isolates belonged to 26 different emm types, including isolates nonsusceptible to erythromycin (n=187), tetracycline (n=99), ciprofloxacin (n=59), and bacitracin (n=43). Results were compared to the activities of 16 other antibiotics for topical and systemic use. Retapamulin MICs ranged from ≤0.015 to 0.12 μg/ml, showing the highest intrinsic activity among the topical antimicrobial drugs studied.     

In-vitro activity of ten antimicrobial agents against penicillin-resistant Streptococcus pneumoniae.

The minimum inhibitory concentrations (MICs) of ten antibiotics were determined by the agar dilution method for 40 strains of penicillin-resistant Streptococcus pneumoniae, all of which were clinical isolates from this laboratory. The antibiotics tested were clarithromycin, erythromycin, teicoplanin, vancomycin, ceftriaxone, cefodizime, azithromycin, ramoplanin, ciprofloxacin and MDL 62873. Of these agents, clarithromycin, vancomycin, teicoplanin, ceftriaxone, ramoplanin and MDL 62873 were the most active. The role of these antibiotics as alternatives to penicillin for the treatment of infections caused by penicillin-resistant S. pneumoniae is discussed.     

Activity of daptomycin against recent North American isolates of Streptococcus pneumoniae

Daptomycin MICs at which 50% of isolates were inhibited (MIC(50)s) and MIC(90)s determined by the NCCLS broth microdilution method were both 0.25 microg/ml (range, 0.06 to 2 microg/ml) for 350 pneumococcal isolates. MICs determined by E test strips on commercially prepared Mueller-Hinton sheep blood agars with different calcium contents were 2 to 3 dilutions higher than those determined by strips that contained daptomycin plus calcium. Daptomycin zone diameters varied little on the same media.     

Comparative in vitro activities of several new fluoroquinolones and beta-lactam antimicrobial agents against community isolates of Streptococcus pneumoniae.

The in vitro susceptibilities of 551 community isolates of Streptococcus pneumoniae from the Canadian province of Ontario to several new fluoroquinolones and beta-lactam antimicrobial agents were determined by a broth microdilution technique. Eight (1.5%) of these isolates were moderately susceptible (MICs, greater than or equal to 0.12 and less than or equal to 1.0 microgram/ml) to penicillin; none was resistant. Temafloxacin, ciprofloxacin, and ofloxacin (MICs for 90% of strains tested, between 1 and 2 micrograms/ml) were the most active fluoroquinolones tested, and BMY-28100 (MIC for 90% of strains tested, 0.25 microgram/ml) was the most active of the new beta-lactams tested.     

Activity of pefloxacin and thirteen other antimicrobial agents in vitro against isolates from hospital and genitourinary infections

The in-vitro activity of the quinolone derivative pefloxacin was compared with that of three other quinolones, five beta-lactam antibiotics and three aminoglycosides against 367 isolates from hospital patients and from out-patients with genitourinary infections. MIC90 of pefloxacin and norfloxacin for each strain was the same; that of ciprofloxacin was a little lower. All strains except Escherichia coli were resistant to nalidixic acid. Pefloxacin was highly active against Staphylococcus aureus (39 strains; MIC90 1.0 mg/l) and most strains of coagulase-negative staphylococci (56; 4 mg/l), Esch. coli (50; 0.25 mg/l), other enterobacteria (33; 1.0 mg/l) and Pseudomonas aeruginosa 6; 0.25 mg/l). With Bacteroides spp. (total 78; 64 mg/l), the fragilis group (23) and the fusobacteria (19) were resistant, but the melaninogenicus-oralis group (31; range 0.06- greater than 64 mg/l) and B. ureolyticus (22; 0.125- greater than 64 mg/l) gave variable results. Amongst genitourinary isolates, Neisseria gonorrhoeae (15) and Haemophilus ducreyi (34) were sensitive (less than 0.06 mg/l) but Gardnerella vaginalis (25) and Mobiluncus spp. (11) were resistant (32 mg/l). Pefloxacin was more active than ceftazidime, cefotaxime, ceftizoxime, latamoxef and piperacillin against S. aureus and coagulase-negative staphylococci and than gentamicin, tobramycin and amikacin against coagulase-negative staphylococci. No enterobacteria or pseudomonads were resistant to pefloxacin or other quinolones, whereas some were resistant to beta-lactams and aminoglycosides.     

Pharmacodynamics of moxifloxacin, levofloxacin and sparfloxacin against Streptococcus pneumoniae

An in vitro pharmacokinetic model (IVPM) was used to simulate the human serum pharmacokinetics of moxifloxacin, levofloxacin and sparfloxacin, and to compare their pharmacodynamics against Streptococcus pneumoniae exhibiting a wide range of susceptibilities to fluoroquinolones. Logarithmic-phase cultures were exposed to peak concentrations achieved in human serum of moxifloxacin, levofloxacin or sparfloxacin with oral doses of 400, 500 and 200 mg, respectively. Human elimination pharmacokinetics were simulated, and viable bacterial counts were measured at 0, 1, 2, 4, 6, 8, 24 and 36 h. Moxifloxacin was rapidly bactericidal (>3 logs of killing) against all 10 S. pneumoniae strains, with 99.9% kills of eight strains occurring within 1-3 h after dosing. Maximum kills ranged from 5 to >6 logs. Moxifloxacin eradicated seven strains from the IVPM within 8 h of the first dose, and eradicated two other strains within 24 h. Although levofloxacin and sparfloxacin were also bactericidal against all 10 S. pneumoniae strains, the rates of killing were somewhat slower, with sparfloxacin exhibiting the slowest rate of kill. In summary, moxifloxacin's increased anti-pneumococcal potency compared with levofloxacin and its more favourable pharmacokinetics compared with sparfloxacin provided enhanced pharmacodynamic activity against some S. pneumoniae strains when maximum doses were simulated in an IVPM.     

In vitro activity of gemifloxacin compared with other antimicrobial agents against recent clinical isolates of streptococci

This study investigated the in vitro activity of gemifloxacin (SB-265805) against 50 recent clinical isolates of Streptococcus pyogenes, Streptococcus agalactiae and viridans streptococci using the microdilution method. This activity was compared with that of the quinolone agents ofloxacin, ciprofloxacin, levofloxacin, trovafloxacin and grepafloxacin, and with that of penicillin, ampicillin, clarithromycin and azithromycin. Gemifloxacin was significantly more potent than the other quinolones tested. Its potency was equal to that of penicillin for S. agalactiae, and superior to that of penicillin for viridans streptococci. The MIC(50) of gemifloxacin for S. pyogenes (0.015 mg/L) was equal to that of penicillin, with an MIC(90) of 0.03 mg/L. Gemifloxacin was also active against isolates of S. agalactiae (MIC = 0.03-0.06 mg/L) and S. pyogenes (MIC = 0.03- 0.06 mg/L) with reduced susceptibility to ofloxacin (MIC = 4-8 mg/L) and grepafloxacin (MIC = 4 mg/L). These preliminary observations indicate that gemifloxacin is a promising antimicrobial agent for clinical use.     

In vitro activity of cefditoren and other antimicrobial agents against 288 Streptococcus pneumoniae and 220 Haemophilus influenzae clinical strains isolated in Zaragoza, Spain

In vitro cefditoren antimicrobial activity was tested against 288 Streptococcus pneumoniae and 220 Haemophilus influenzae clinical strains isolated in our hospital from January 2005 to May 2006 by agar dilution and broth microdilution method, respectively. MICs were also determined for 13 and 10 comparison drugs, respectively. The pneumococci tested comprised 113 (39.2%) penicillin susceptible, 91 (31.6%) penicillin intermediate, and 84 (29.2%) penicillin resistant. Cefditoren was the most active drug on the basis of the MICs (MIC(90)=0.5 microg/mL), followed by ceftriaxone and levofloxacin (MIC(90)=1 microg/mL). Cefditoren MICs ranged from 0.25 to 1 microg/mL for ceftriaxone-resistant isolates, with a modal MIC of 0.5 microg/mL and an MIC(90) of 1.0 microg/mL. No S. pneumoniae isolates evaluated in this study showed MICs to cefditoren higher than 1 microg/mL (MIC range, 4 microg/mL). Against H. influenzae (Hi beta+), the rank order of intrinsic activity (MIC(90), microg/mL) was cefditoren (0.03) < cefixime (0.06)8.0).     

In vitro activities of five fluoroquinolone compounds against strains of Streptococcus pneumoniae with resistance to other antimicrobial agents.

Ciprofloxacin, clinafloxacin, PD 131628, sparfloxacin, and trovafloxacin were tested against 236 strains of Streptococcus pneumoniae, most of which were resistant to other agents. Resistance to multiple antibiotics did not affect the organism's susceptibility to the fluoroquinolones. The fluoroquinolones with in vitro antipneumococcal activity might be particularly useful against strains that are resistant to the more traditional therapeutic agents.     

The activity of levofloxacin and comparator agents against clinical isolates of Streptococcus pneumoniae collected worldwide during 1999 and 2000

BACKGROUND: Increases in penicillin-resistant Streptococcus pneumoniae have been documented worldwide. METHODS: During 1999 and 2000, 5,015 S. pneumoniae isolates were collected from 13 countries on five continents and tested for antimicrobial susceptibility. RESULTS: Penicillin resistance rates were as follows: South Korea, 70.1%; Hong Kong, 50.3%; Thailand, 39.3%; France, 28.7%; Spain, 24.8%; Mexico, 18.1%; Ireland, 11.8%; South Africa, 11.1%; Italy, 9.4%; United Kingdom, 3.1%; Brazil, 2.9%; China, 2.3%, and Germany, 0.7%. Resistance to azithromycin, clarithromycin and trimethoprim-sulfamethoxazole was commonly associated with penicillin resistance. Levofloxacin-resistant isolates were detected in 8 of 13 countries: Germany (0.2%), France (0.4%), Thailand (0.5%), South Korea (0.9%), Mexico (1.5%), Spain (1.6%), China (3.3%) and Hong Kong (8.0%). Multidrug resistance (resistance to >/=3 antimicrobial classes) occurred in 626/5,015 isolates (12.5%). Levofloxacin was active against 96.0% (601/626) of the multidrug-resistant (MDR) isolates and 99.7% (4,374/4,389) of the non-MDR isolates. CONCLUSION: Although relatively high levels of levofloxacin resistance were detected in China and Hong Kong, overall, levofloxacin remained active against >99% of clinical isolates of S. pneumoniae despite their resistance to other agents. Continued surveillance of S. pneumoniae will track any changes in levofloxacin activity, should they occur.     

Activity of the new quinolones WCK 771, WCK 1152 and WCK 1153 against clinical isolates of Streptococcus pneumoniae and Streptococcus pyogenes

Objectives and methods: The new fluoroquinolones WCK 771, WCK 1152 and WCK 1153 were developed to overcome quinolone resistance in Gram-positive bacteria. The activity of these new quinolones was tested against 159 clinical isolates of Streptococcus pneumoniae and 52 clinical isolates of Streptococcus pyogenes using the microbroth dilution method. RESULTS: MIC50/MIC90 values (mg/L) of WCK 771, WCK 1152 and WCK 1153 for quinolone-susceptible S. pneumoniae (n = 119; 54 penicillin G-susceptible, 53 penicillin G-intermediate, and 12 penicillin G-resistant strains) were 0.25/0.5, 0.03/0.06 and 0.016/0.03, respectively. MIC50/MIC90 values (mg/L) for quinolone-resistant pneumococci (n = 40) increased to 4/16, 0.25/1 and 0.125/0.5, respectively. Against S. pyogenes, WCK 771, WCK 1152 and WCK 1153 were also highly active with MIC50/MIC90 values (mg/L) of 0.25/0.25, 0.03/0.06 and 0.03/0.03, respectively. CONCLUSIONS: Overall, WCK 771 was highly active against quinolone-susceptible, but not against quinolone-resistant S. pneumoniae, whereas WCK 1152 and WCK 1153 were more potent and were able to overcome quinolone resistance in both S. pneumoniae and S. pyogenes.     

Activity of newer beta-lactam agents against clinical isolates of Bacteroides fragilis and other Bacteroides species.

The in vitro activities of beta-lactam antibiotics against Bacteroides fragilis and B. fragilis group isolates are presented. Clinical isolates from 1986 were compared with strains from 1979 to 1982. Imipenem, ticarcillin-clavulanic acid, and ceftizoxime were the most active agents. Cefotetan was equivalent to cefoxitin against B. fragilis but less active against B. fragilis group isolates. Enhancement of cefotaxime by its desacetyl metabolite was minimal.