scholarly journals In Vitro Susceptibilities of Aerobic and Facultative Non-Spore-Forming Gram-Positive Bacilli to HMR 3647 (RU 66647) and 14 Other Antimicrobials

1998 ◽  
Vol 42 (5) ◽  
pp. 1028-1033 ◽  
Author(s):  
Francisco Soriano ◽  
Ricardo Fernández-Roblas ◽  
Raquel Calvo ◽  
Gloria García-Calvo
Keyword(s):  
Vitro Activity ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Glycopeptide Antibiotics ◽  
Erysipelothrix Rhusiopathiae ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Corynebacterium Striatum ◽  
Corynebacterium Pseudodiphtheriticum

ABSTRACT The comparative in vitro activity of the ketolide HMR 3647 (RU 66647) and those of structurally related macrolide-lincosamide-streptogramin compounds (erythromycin, roxithromycin, azithromycin, clarithromycin, josamycin, lincomycin, pristinamycin, and quinupristin-dalfopristin) as well as those of benzylpenicillin, doxycycline, vancomycin, teicoplanin, levofloxacin, and rifapentine against 247 aerobic and facultative non-spore-forming gram-positive bacilli were determined by an agar dilution method. The ketolide was active against most organisms tested exceptCorynebacterium striatum, coryneform CDC group I2, andOerskovia spp. The frequency of resistance to erythromycin and other macrolides as well as that to lincomycin was high. Pristinamycin and, to a lesser extent, quinupristin-dalfopristin were very active, but resistance to these agents was present in some strains of Rhodococcus equi, Listeria spp., C. striatum, Erysipelothrix rhusiopathiae, andOerskovia spp. HMR 3647 was very active against all erythromycin-sensitive and many erythromycin-nonsusceptible strains, especially Corynebacterium minutissimum,Corynebacterium pseudodiphtheriticum, Corynebacterium amycolatum, and Corynebacterium jeikeium. In vitro resistance to benzylpenicillin was common, but doxycycline, vancomycin, and teicoplanin were very active against most organisms tested exceptE. rhusiopathiae, against which glycopeptide antibiotics were not active. The in vitro activity of levofloxacin was remarkable, but resistance to this agent was common for C. amycolatum,Corynebacterium urealyticum, C. jeikeium, andOerskovia spp. strains. Rifapentine was also very active in vitro against many organisms, but resistance to this agent was always present in E. rhusiopathiae and was very common in C. striatum and C. urealyticum.

In vitro activity of a novel antibacterial agent, levonadifloxacin, against clinical isolates collected in a prospective, multicentre surveillance study in India during 2016–18

2019 ◽  
Vol 75 (3) ◽  
pp. 600-608 ◽  
Author(s):  
Boppe Appalaraju ◽  
Sujata Baveja ◽  
Shrikala Baliga ◽  
Suchitra Shenoy ◽  
Renu Bhardwaj ◽  
...  
Keyword(s):  
Therapeutic Option ◽  
Tertiary Care ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Surveillance Study ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
In Vitro Activity ◽  
Broth Microdilution Method

Abstract Background Levonadifloxacin is a novel antibiotic belonging to the benzoquinolizine subclass of fluoroquinolones with potent activity against MRSA and quinolone-resistant Staphylococcus aureus. IV levonadifloxacin and its oral prodrug alalevonadifloxacin have recently been approved in India for the treatment of acute bacterial skin and skin structure infections (ABSSSIs) including diabetic foot infections. Objectives To investigate the in vitro activity of levonadifloxacin against contemporary clinical isolates collected from multiple tertiary care hospitals across India in the Antimicrobial Susceptibility Profiling of Indian Resistotypes (ASPIRE) surveillance study. Methods A total of 1376 clinical isolates, consisting of staphylococci (n = 677), streptococci (n = 178), Enterobacterales (n = 320), Pseudomonas aeruginosa (n = 140) and Acinetobacter baumannii (n = 61), collected (2016–18) from 16 tertiary hospitals located across 12 states in India, were included in the study. The MICs of levonadifloxacin and comparator antibiotics were determined using the reference agar dilution method and broth microdilution method. Results Levonadifloxacin exhibited potent activity against MSSA (MIC50/90: 0.5/1 mg/L), MRSA (MIC50/90: 0.5/1 mg/L) and levofloxacin-resistant S. aureus (MIC50/90: 1/1 mg/L) isolates. Similarly, potent activity of levonadifloxacin was also observed against CoNS including MDR isolates (MIC50/90: 1/2 mg/L). Against Streptococcus pneumoniae, levonadifloxacin (MIC50/90: 0.5/0.5 mg/L) showed superior activity compared with levofloxacin (MIC50/90: 1/2 mg/L). Among levofloxacin-susceptible Enterobacterales, 80.6% of isolates were inhibited at ≤2 mg/L levonadifloxacin. Conclusions Levonadifloxacin displayed potent activity against contemporary MRSA and fluoroquinolone-resistant staphylococcal isolates, thus offering a valuable IV as well as an oral therapeutic option for the treatment of ABSSSIs. Furthermore, levonadifloxacin exhibited a broad-spectrum activity profile as evident from its activity against streptococci and levofloxacin-susceptible Gram-negative isolates.

scholarly journals Time-Kill and Synergism Studies of Ceftobiprole against Enterococcus faecalis, Including β-Lactamase-Producing and Vancomycin-Resistant Isolates

2007 ◽  
Vol 51 (6) ◽  
pp. 2043-2047 ◽  
Author(s):  
Cesar A. Arias ◽  
Kavindra V. Singh ◽  
Diana Panesso ◽  
Barbara E. Murray
Keyword(s):  
Enterococcus Faecalis ◽  
Vitro Activity ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
In Vitro Activity ◽  
Inoculum Concentration ◽  
High Inoculum ◽  
Vancomycin Resistant ◽  
Time Kill

ABSTRACT Ceftobiprole (BAL9141) is an investigational cephalosporin with broad in vitro activity against gram-positive cocci, including enterococci. Ceftobiprole MICs were determined for 93 isolates of Enterococcus faecalis (including 16 β-lactamase [Bla] producers and 17 vancomycin-resistant isolates) by an agar dilution method following the Clinical and Laboratory Standards Institute recommendations. Ceftobiprole MICs were also determined with a high inoculum concentration (107 CFU/ml) for a subset of five Bla producers belonging to different previously characterized clones by a broth dilution method. Time-kill and synergism studies (with either streptomycin or gentamicin) were performed with two β-lactamase-producing isolates (TX0630 and TX5070) and two vancomycin-resistant isolates (TX2484 [VanB] and TX2784 [VanA]). The MICs of ceftobiprole for 50 and 90% of the isolates tested were 0.25 and 1 μg/ml, respectively. All Bla producers and vancomycin-resistant isolates were inhibited by concentrations of ≤1 and ≤4 μg/ml, respectively, at the standard inoculum concentration. Ceftobiprole MICs at a high inoculum concentration for a subset of five Bla+ E. faecalis isolates were ≤1 μg/ml. Bactericidal activity was observed against four isolates tested at concentrations as low as 1 μg/ml regardless of the production of β-lactamase or vancomycin resistance. A combination of ceftobiprole (0.5 μg/ml) and streptomycin (25 μg/ml) was synergistic against Bla+ TX0630 and TX5070. Ceftobiprole (0.5 μg/ml) plus gentamicin (10 μg/ml) was synergistic against VanB isolate TX2484 and showed enhanced killing, but not synergism, against TX2784 (VanA), despite the absence of high-level resistance to gentamicin. In conclusion, ceftobiprole exhibited good in vitro activity against E. faecalis, including Bla+ and vancomycin-resistant strains, and exhibited synergism with aminoglycosides against selected isolates.

scholarly journals In Vitro Activity of Moxifloxacin against 923 Anaerobes Isolated from Human Intra-Abdominal Infections

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 ◽  
...  
Keyword(s):  
Bacteroides Fragilis ◽  
Vitro Activity ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Species Variation ◽  
In Vitro Activity ◽  
Resistant Species ◽  
Agar Dilution ◽  
Abdominal Infections

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.

scholarly journals Comparative In Vitro Activities of Retapamulin (SB-275833) against 141 Clinical Isolates of Propionibacterium spp., Including 117 P. acnes Isolates

2006 ◽  
Vol 50 (1) ◽  
pp. 379-381 ◽  
Author(s):  
Ellie J. C. Goldstein ◽  
Diane M. Citron ◽  
C. Vreni Merriam ◽  
Yumi A. Warren ◽  
Kerin L. Tyrrell ◽  
...  
Keyword(s):  
Active Agent ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
In Vitro Activity ◽  
Agar Dilution ◽  
Multiresistant Strains

ABSTRACT Using the NCCLS agar dilution method, we studied the in vitro activity of retapamulin (SB-275833) against 141 clinical isolates of Propionibacterium species, including seven multiresistant strains, and found retapamulin to be the most active agent among those tested with MICs of ≤1 μg/ml against all isolates.

scholarly journals Comparison of in vitro activity of various macrolides against Helicobacter pylori

2018 ◽  
Vol 20 (3) ◽  
pp. 192-197
Author(s):  
Natalya N. Dekhnich ◽  
Nataly V. Ivanchik ◽  
Roman S. Kozlov
Keyword(s):  
Vitro Activity ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
In Vitro Activity ◽  
Minimal Inhibitory Concentrations ◽  
Biopsy Specimens ◽  
Agar Dilution ◽  
H Pylori ◽  
Comparison Of The Results

Objective. Compare the in vitro activity of clarithromycin, erythromycin, azithromycin and josamycin against the collection of H. pylori strains isolated in 2010–2017 in Smolensk. Materials and Methods. H. pylori strains were collected prospectively from biopsy specimens of the gastric mucosa. Antimicrobial susceptibility testing of H. pylori was performed by the agar dilution method. Interpretation of the results of the susceptibility determination for clarithromycin was carried out in accordance with the recommendations of EUCAST (v 8.0) 2018. The resistance breakpoints for erythromycin, azithromycin, and josamycin were all set at ≥1.0 mg/L. For comparison of the results, the value of the minimal inhibitory concentrations of the tested antibiotic inhibiting the growth of 50% (MIC50) and 90% (MIC90) of H. pylori strains was used. Results. A total of 276 H. pylori strains were tested. 90% of the MIC values of clarithromycin were in the range from 0.015 to 0.125 mg/l. The percentages of resistance were as follows: clarithromycin 5.1%, azithromycin 7.5%, erythromycin 8%, josamycin 23.2%. Clarithromycin demonstrated significantly higher activity in suppressing the growth of H. pylori strains than azithromycin, erythromycin, and josamycin. Conclusions. Among the tested macrolide antibiotics maximal anti-H. pylori activity in vitro was observed in clarithromycin.

scholarly journals In Vitro Activities of Daptomycin, Vancomycin, Quinupristin- Dalfopristin, Linezolid, and Five Other Antimicrobials against 307 Gram-Positive Anaerobic and 31 Corynebacterium Clinical Isolates

2003 ◽  
Vol 47 (1) ◽  
pp. 337-341 ◽  
Author(s):  
Ellie J. C. Goldstein ◽  
Diane M. Citron ◽  
C. Vreni Merriam ◽  
Yumi A. Warren ◽  
Kerrin L. Tyrrell ◽  
...  
Keyword(s):  
Anaerobic Bacteria ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Gram Positive ◽  
Cyclic Lipopeptide ◽  
Highly Active ◽  
Mueller Hinton Agar ◽  
Vancomycin Resistant ◽  
Corynebacterium Pseudodiphtheriticum

ABSTRACT The activities of daptomycin, a cyclic lipopeptide, and eight other agents were determined against 338 strains of gram-positive anaerobic bacteria and corynebacteria by the NCCLS reference agar dilution method with supplemented brucella agar for the anaerobes and Mueller-Hinton agar for the corynebacteria. The daptomycin MICs determined on Ca2+-supplemented (50 mg/liter) brucella agar plates were one- to fourfold lower than those determined in unsupplemented media. Daptomycin was highly active (MICs, ≤2 μg/ml) against many strains including 36 of 37 peptostreptococci, 37 of 48 isolates of the Eubacterium group, and all strains of Propionibacterium spp., Clostridium perfringens, Clostridium difficile, and other Clostridium spp. It was fourfold or greater more active than vancomycin against Clostridium innocuum and 16 of 34 strains of vancomycin-resistant lactobacilli. Three strains of C. difficile for which quinupristin-dalfopristin and linezolid MICs were >8 μg/ml were inhibited by <1 μg of daptomycin per ml. Daptomycin MICs were ≥4 μg/ml for most strains of Clostridium clostridioforme, Clostridium paraputrificum, Clostridium tertium, and Clostridium ramosum; the isolates were generally more resistant to other antimicrobials. Daptomycin was two- to fourfold less active against Actinomyces spp. than vancomycin, quinupristin-dalfopristin, or linezolid. Twenty-nine of 31 strains of Corynebacterium spp., including Corynebacterium jeikeium, Corynebacterium amycolatum, and Corynebacterium pseudodiphtheriticum, were inhibited by ≤0.25 μg of daptomycin per ml. For two strains of “Corynebacterium aquaticum,” 8 μg of daptomycin per ml was required for inhibition. Daptomycin demonstrated very good activities against a broad range of gram-positive organisms including vancomycin-resistant C. innocuum and lactobacillus strains and quinupristin-dalfopristin- and linezolid-resistant C. difficile strains.

scholarly journals Comparative In Vitro Activity of Ceftobiprole against Staphylococci Displaying Normal and Small-Colony Variant Phenotypes

2005 ◽  
Vol 49 (10) ◽  
pp. 4372-4374 ◽  
Author(s):  
Christof von Eiff ◽  
Alexander W. Friedrich ◽  
Karsten Becker ◽  
Georg Peters
Keyword(s):  
Staphylococcus Aureus ◽  
Vitro Activity ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
In Vitro Activity ◽  
Small Colony Variant ◽  
Antistaphylococcal Activity ◽  
Agar Dilution ◽  
Small Colony

ABSTRACT The antistaphylococcal activity of ceftobiprole was compared with those of cefuroxime, linezolid, and moxifloxacin by using the agar dilution method. Apart from three strains with small-colony variant phenotypes, all Staphylococcus aureus isolates tested were inhibited by ≤2 μg/ml of ceftobiprole. This compound exhibited an excellent antistaphylococcal activity, comparable to that of linezolid.

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