scholarly journals In Vitro Activities of a New Des-Fluoro(6) Quinolone, Garenoxacin, against Clinical Anaerobic Bacteria

2003 ◽  
Vol 47 (11) ◽  
pp. 3667-3671 ◽  
Author(s):  
A. Liebetrau ◽  
A. C. Rodloff ◽  
J. Behra-Miellet ◽  
L. Dubreuil

ABSTRACT The antimicrobial activities of garenoxacin and eight other antibiotics against 641 anaerobic isolates were evaluated with the NCCLS agar dilution method. Overall, the MICs of garenoxacin for 50 and 90% of the strains tested (in micrograms per milliliter) were as follows: Bacteroides fragilis group, 0.5 and 2; Prevotella spp., 0.25 and 2; Fusobacterium spp., 0.25 and 0.5; Porphyromonas spp., 0.125 and 0.25; Bilophila wadsworthia, 0.5 and 1; Veillonella spp., 0.25 and 0.5; Clostridium spp., 0.25 and 1; Clostridium difficile, 2 and >64; Bifidobacterium spp., 1 and 2; Eggerthella lenta, 0.25 and 1; Propionibacterium spp., 0.5 and 0.5; gram-positive cocci, 0.125 and 0.25.

2003 ◽  
Vol 47 (7) ◽  
pp. 2334-2338 ◽  
Author(s):  
D. M. Citron ◽  
C. V. Merriam ◽  
K. L. Tyrrell ◽  
Y. A. Warren ◽  
H. Fernandez ◽  
...  

ABSTRACT By using an agar dilution method, the in vitro activities of ramoplanin, teicoplanin, vancomycin, linezolid, and five other agents were determined against 300 gram-positive and 54 gram-negative strains of intestinal anaerobes. Ramoplanin was active at ≤2 μg/ml against 287 of 300 (95.7%) gram-positive organisms, including 18 strains of Clostridium difficile for which MICs of ramoplanin were 0.25 to 0.5 μg/ml; for 3 of these, linezolid MICs were 8 to 16 μg/ml. Nineteen Clostridium innocuum strains for which the vancomycin MIC at which 90% of strains were inhibited was 16 μg/ml were susceptible to ramoplanin at 0.06 to 0.25 μg/ml and to teicoplanin at 0.125 to 1.0 μg/ml. All strains of Eubacterium, Actinomyces, Propionibacterium, and Peptostreptococcus spp. were inhibited by ≤0.25 μg of ramoplanin per ml and ≤1 μg of vancomycin per ml. Ramoplanin was also active at ≤4 μg/ml against 15 of 22 of the Prevotella and Porphyromonas strains tested, but ramoplanin MICs for all 31 strains of the Bacteroides fragilis group, the Fusobacterium mortiferum-Fusobacterium varium group, and Veillonella spp. were ≥256 μg/ml. Ramoplanin displays excellent activity against C. difficile and other gram-positive enteric anaerobes, including vancomycin-resistant strains; however, it has poor activity against most gram-negative anaerobes and thus potentially has a lesser effect on the ecological balance of normal fecal flora.


2006 ◽  
Vol 50 (8) ◽  
pp. 2728-2731 ◽  
Author(s):  
Kerin L. Tyrrell ◽  
Diane M. Citron ◽  
Yumi A. Warren ◽  
Helen T. Fernandez ◽  
C. Vreni Merriam ◽  
...  

ABSTRACT Daptomycin has in vitro activity against gram-positive anaerobic bacteria, although limited numbers of species have been tested. We studied the in vitro activities of daptomycin, vancomycin, and penicillin against more than 100 strains each of Clostridium difficile, C. perfringens, Finegoldia magna, and Propionibacterium acnes. Daptomycin Etest MICs and results from time-kill studies were determined for selected strains. For 392 of 421 strains (93%), daptomycin was inhibitory at ≤1 μg/ml, including 15 of 16 strains of C. difficile with elevated linezolid MICs of 8 and 16 μg/ml, all 32 strains with moxifloxacin MICs of ≥4 μg/ml, and all 16 strains resistant to clindamycin. Daptomycin MICs were also ≤1 μg/ml for all 16 F. magna strains resistant to clindamycin and all 32 strains resistant to tetracycline. Only one strain, a C. perfringens strain, had a MIC of >2 μg/ml to daptomycin. Eighty-five and 92.5% of the Etest MICs were within 1 dilution of the agar dilution method for all drugs at 24 and 48 h, respectively. In time-kill studies, a C. difficile strain was inhibited by both daptomycin and vancomycin at 1, 2, 4, 8, and 24 h; colony counts were decreased by 2.3 to 2.9 log at 24 h. Vancomycin was not bactericidal for C. perfringens; however, daptomycin showed bactericidal activity as early as 1 h at four and eight times the MIC and at 2 and 4 h at two and four times the MIC.


2005 ◽  
Vol 49 (1) ◽  
pp. 408-413 ◽  
Author(s):  
Ellie J. C. Goldstein ◽  
Diane M. Citron ◽  
C. Vreni Merriam ◽  
Yumi A. Warren ◽  
Kerin L. Tyrrell ◽  
...  

ABSTRACT A comparative study of the in vitro activities of XRP 2868, a new oral streptogramin, against 266 anaerobic gram-positive clinical isolates using the agar dilution method showed that the XRP 2868 MICs for 95% (254 of 266) of isolates were ≤0.5 μg/ml. XRP 2868 MICs for only two strains, one being Clostridium clostridioforme (MIC, 16 μg/ml) and the other being Clostridium difficile (MIC, 32 μg/ml), were >2 μg/ml. Depending on its pharmacokinetics and pharmacodynamics, XRP 2868 has potential for use against infections with gram-positive anaerobes and deserves further clinical evaluation.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Séverine Boisard ◽  
Anne-Marie Le Ray ◽  
Anne Landreau ◽  
Marie Kempf ◽  
Viviane Cassisa ◽  
...  

During this study, thein vitroantifungal and antibacterial activities of different extracts (aqueous and organic) obtained from a French propolis batch were evaluated. Antifungal activity was evaluated by broth microdilution on three pathogenic strains:Candida albicans, C. glabrata, andAspergillus fumigatus. Antibacterial activity was assayed using agar dilution method on 36 Gram-negative and Gram-positive strains includingStaphylococcus aureus. Organic extracts showed a significant antifungal activity againstC. albicansandC. glabrata(MIC80between 16 and 31 µg/mL) but only a weak activity towardsA. fumigatus(MIC80= 250 µg/mL). DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially againstS. aureus(SA) and several of its methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains (MIC10030–97 µg/mL). A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study.


2015 ◽  
Vol 59 (10) ◽  
pp. 6262-6265 ◽  
Author(s):  
Ko-Hung Chen ◽  
Yu-Tsung Huang ◽  
Chun-Hsing Liao ◽  
Wang-Hui Sheng ◽  
Po-Ren Hsueh

ABSTRACTTedizolid is a novel, expanded-spectrum oxazolidinone with potent activity against a wide range of Gram-positive pathogens. A total of 425 isolates of Gram-positive bacteria were obtained consecutively from patients with acute bacterial skin and skin structure infections (ABSSSIs) or pneumonia. These isolates included methicillin-susceptibleStaphylococcus aureus(MSSA) (n= 100), methicillin-resistantStaphylococcus aureus(MRSA) (n= 100),Streptococcus pyogenes(n= 50),Streptococcus agalactiae(n= 50),Streptococcus anginosusgroup (n= 75),Enterococcus faecalis(n= 50), and vancomycin-resistant enterococci (VRE) (Enterococcus faecium) (n= 50). The MICs of tedizolid and linezolid were determined by the agar dilution method. Tedizolid exhibited betterin vitroactivities than linezolid against MSSA (MIC90s, 0.5 versus 2 μg/ml), MRSA (MIC90s, 0.5 versus 2 μg/ml),S. pyogenes(MIC90s, 0.5 versus 2 μg/ml),S. agalactiae(MIC90s, 0.5 versus 2 μg/ml),Streptococcus anginosusgroup (MIC90s, 0.5 versus 2 μg/ml),E. faecalis(MIC90s, 0.5 versus 2 μg/ml), and VRE (MIC90s, 0.5 versus 2 μg/ml). The tedizolid MICs againstE. faecalis(n= 3) and VRE (n= 2) intermediate to linezolid (MICs, 4 μg/ml) were 1 μg/ml and 0.5 μg/ml, respectively. The tedizolid MIC90s against S. anginosus,S. constellatus, andS. intermediuswere 0.5, 1, and 0.5 μg/ml, respectively, and the rates of susceptibility based on the U.S. FDA MIC interpretive breakpoints to the isolates were 16%, 28%, and 72%, respectively. Tedizolid exhibited 2- to 4-fold betterin vitroactivities than linezolid against a variety of Gram-positive cocci associated with ABSSSIs and pneumonia. The lower susceptibilities of tedizolid against isolates ofS. anginosusandS. constellatusthan against those ofS. intermediusin Taiwan were noted.


2000 ◽  
Vol 44 (2) ◽  
pp. 283-286 ◽  
Author(s):  
Haruaki Tomioka ◽  
Katsumasa Sato ◽  
Hiroko Kajitani ◽  
Tatsuya Akaki ◽  
Shinji Shishido

ABSTRACT WQ-3034 is a newly synthesized acidic fluoroquinolone. We assessed its in vitro activity against Mycobacterium tuberculosisand M. avium complex using levofloxacin (LVFX), ciprofloxacin (CPFX), sparfloxacin (SPFX), and KRM-1648 (KRM) as reference drugs. The MICs of these agents were determined by the agar dilution method with 7H11 medium. The MICs at which 50 and 90% of the test strains were inhibited (MIC50s, and MIC90s, respectively) for the test quinolones for rifampin (RMP)-susceptible M. tuberculosis strains were in the order SPFX < LVFX ≦ WQ-3034 ≦ CPFX, while those for RMP-resistant M. tuberculosis strains were in the order SPFX ≦ WQ-3034 ≦ LVFX < CPFX. The MICs of KRM for RMP-susceptible M. tuberculosis were much lower than those of the test quinolones, while the MIC90 of KRM for RMP-resistant M. tuberculosis strains was higher than those of the quinolones. The MIC50s and MIC90s of the test drugs for M. avium were in the order KRM < SPFX < CPFX ≦ WQ-3034 ≦ LVFX, while those forM. intracellulare were in the order KRM < SPFX < WQ-3034 ≒ LVFX ≦ CPFX. Next, we compared the antimicrobial activities of the test drugs against M. tuberculosisorganisms residing in cells of the Mono Mac 6 macrophage (Mφ)-like cell line (MM6-Mφs) and of the A-549 type II alveolar cell line (A-549 cells). When drugs were added at the concentration that achieves the maximum concentration in blood, progressive killing or inhibition of the M. tuberculosis organisms residing in MM6-Mφs and A-549 cells was observed in the order KRM > SPFX ≧ LVFX > WQ-3034 > CPFX. The efficacies of all quinolones against intracellular M. tuberculosis organisms were significantly lower in A-549 cells than in MM6-Mφs. WQ-3034 at the MIC caused more marked growth inhibition of intramacrophage M. tuberculosis than did LVFX. These findings indicate that the in vitro anti-M. tuberculosis activity of WQ-3034 is greater than that of CPFX and is comparable to that of LVFX.


2011 ◽  
Vol 8 (3) ◽  
pp. 1120-1123 ◽  
Author(s):  
Bahram Letafat ◽  
Negar Mohammadhosseini ◽  
Ali Asadipour ◽  
Alireza Foroumadi

In the present study we report the synthesis and antibacterial activity of a new series 2-(1-methyl-4-nitro-1H-imidazol-5-ylsulfonyl)-1,3,4-thiadiazoles (6a-c). Compounds6a-cwere testedin vitroby the conventional agar dilution method against a panel of microorganisms including gram-negative and gram-positive bacteria. Compound6bwith 5-(5-nitrofuran-2-yl)-residue on 1,3,4-thiadiazole scaffold have shown promising antibacterial activities against gram-positive bacteria includingStaphylococcus aureus, Staphylococcus epidermidisandBacillus subtilis.


2003 ◽  
Vol 47 (6) ◽  
pp. 1968-1971 ◽  
Author(s):  
Ellie J. C. Goldstein ◽  
Diane M. Citron ◽  
C. Vreni Merriam ◽  
Yumi Warren ◽  
Kerin Tyrrell ◽  
...  

ABSTRACT Dalbavancin is a novel semisynthetic glycopeptide with enhanced activity against gram-positive species. Its comparative in vitro activities and those of nine comparator agents, including daptomycin, vancomycin, linezolid, and quinupristin-dalfopristin, against 290 recent gram-positive clinical isolates strains, as determined by the NCCLS agar dilution method, were studied. The MICs of dalbavancin at which 90% of various isolates tested were inhibited were as follows: Actinomyces spp., 0.5 μg/ml; Clostridium clostridioforme, 8 μg/ml; C. difficile, 0.25 μg/ml; C. innocuum, 0.25 μg/ml; C. perfringens, 0.125 μg/ml; C. ramosum, 1 μg/ml; Eubacterium spp., 1 μg/ml; Lactobacillus spp., >32 μg/ml, Propionibacterium spp., 0.5 μg/ml; and Peptostreptococcus spp., 0.25 μg/ml. Dalbavancin was 1 to 3 dilutions more active than vancomycin against most strains. Dalbavancin exhibited excellent activity against gram-positive strains tested and warrants clinical evaluation.


2006 ◽  
Vol 50 (1) ◽  
pp. 148-155 ◽  
Author(s):  
Ellie J. C. Goldstein ◽  
Diane M. Citron ◽  
Yumi A. Warren ◽  
Kerin L. Tyrrell ◽  
C. Vreni Merriam ◽  
...  

ABSTRACT The in vitro activity of moxifloxacin against 923 recent anaerobic isolates obtained from pretreatment cultures in patients with complicated intra-abdominal infections was studied using the CLSI M11-A-6 agar dilution method. Moxifloxacin was active against 87% (96 of 110) Bacteroides fragilis strains at ≤1 μg/ml and 87% (79 of 90) B. thetaiotaomicron strains at ≤2 μg/ml. Species variation was seen, with B. uniformis, B. vulgatus, Clostridium clostridioforme, and C. symbiosum being least susceptible and accounting for most of the resistant isolates; excluding the aforementioned four resistant species, 86% (303 of 363) of Bacteroides species isolates and 94% (417 of 450) of all other genera and species were susceptible to ≤2 μg/ml of moxifloxacin. Overall, moxifloxacin was active against 763 of 923 (83%) of strains at ≤2 μg/ml, supporting its use as a monotherapy for some community-acquired intra-abdominal infections.


2001 ◽  
Vol 45 (7) ◽  
pp. 1977-1981 ◽  
Author(s):  
Herin Oh ◽  
Nagwa El Amin ◽  
Todd Davies ◽  
Peter C. Appelbaum ◽  
Charlotta Edlund

ABSTRACT Mutations in the gyrA gene contribute considerably to quinolone resistance in Escherichia coli. Mechanisms for quinolone resistance in anaerobic bacteria are less well studied. TheBacteroides fragilis group are the anaerobic organisms most frequently isolated from patients with bacteremia and intraabdominal infections. Forty-four clinafloxacin-resistant and-susceptible fecal and clinical isolates of the B. fragilis group (eightBacteroides fragilis, three Bacteroides ovatus, five Bacteroides thetaiotaomicron, six Bacteroides uniformis, and 22 Bacteroides vulgatus) and six ATCC strains of the B. fragilis group were analyzed as follows: (i) determination of susceptibility to ciprofloxacin, levofloxacin, moxifloxacin, and clinafloxacin by the agar dilution method and (ii) sequencing of the gyrA quinolone resistance-determining region (QRDR) located between amino acid residues equivalent to Ala-67 through Gln-106 in E. coli. Amino acid substitutions were found at hotspots at positions 82 (n = 15) and 86 (n = 8). Strains with Ser82Leu substitutions (n = 13) were highly resistant to all quinolones tested. Mutations in other positions of gyrA were also frequently found in quinolone-resistant and -susceptible isolates. Eight clinical strains that lacked mutations in their QRDR were susceptible to at least two of the quinolones tested. Although newer quinolones have good antimicrobial activity against the B. fragilis group, quinolone resistance in B. fragilisstrains can be readily selected in vivo. Mutational events in the QRDR of gyrA seem to contribute to quinolone resistance inBacteroides species.


Sign in / Sign up

Export Citation Format

Share Document