scholarly journals High incidence of erythromycin-resistant streptococci in Taiwan.

1997 ◽  
Vol 41 (4) ◽  
pp. 844-846 ◽  
Author(s):  
J J Wu ◽  
K Y Lin ◽  
P R Hsueh ◽  
J W Liu ◽  
H I Pan ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Streptococcal Infections ◽  
Broth Microdilution ◽  
Erythromycin Resistance ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
High Incidence ◽  
Group B ◽  
Viridans Group Streptococci

The activities of nine antimicrobial agents against 247 isolates of group B, C, F, and G streptococci and viridans group streptococci were studied by the broth microdilution method. Erythromycin resistance was found in 29.7, 41.7, 81.8, 23.5, and 53.3% of the strains of group B, C, F, and G streptococci and viridans group streptococci tested, respectively. Macrolides are not considered an optimal alternative to penicillin in the treatment of streptococcal infections, at least empirically, in Taiwan.

scholarly journals Determination of CEM-101 Activity Tested against Clinical Isolates of Neisseria meningitidis from a Worldwide Collection

2010 ◽  
Vol 54 (9) ◽  
pp. 4009-4011 ◽  
Author(s):  
Douglas J. Biedenbach ◽  
Mariana Castanheira ◽  
Ronald N. Jones
Keyword(s):  
Neisseria Meningitidis ◽  
Meningococcal Disease ◽  
Antimicrobial Agents ◽  
Clinical Isolates ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method

ABSTRACT The activity of CEM-101, a fluoroketolide, was compared to those of 11 other antimicrobial agents using the reference broth microdilution method tested against 103 Neisseria meningitidis strains, including ciprofloxacin-nonsusceptible isolates with confirmed gyr A (T91I) mutations. Among the tested isolates, 79.6% were serogroup B or C and all isolates were susceptible to ceftriaxone, azithromycin, minocycline, and rifampin. However, penicillin-nonsusceptible strains were observed (15.5%) and susceptibility to trimethoprim-sulfamethoxazole was only 50.5%. CEM-101 was the most active macrolide-like compound (MIC90, ≤0.015 μg/ml) compared with MIC90s of telithromycin (MIC90, 0.03 μg/ml), azithromycin and clarithromycin (MIC90, 0.12 μg/ml), and erythromycin (MIC90, 0.25 μg/ml). CEM-101 could provide a potent alternative for the prophylaxis of meningococcal disease.

scholarly journals Antimicrobial and modulation effects of selected Ghanaian medicinal plants

2017 ◽  
Vol 36 (3) ◽  
pp. 1-7
Author(s):  
E. Ekuadzi ◽  
R. A. Dickson ◽  
T. C. Fleischer ◽  
S. O. Dapaah ◽  
E. O. Reynolds ◽  
...  
Keyword(s):  
Medicinal Plants ◽  
Plant Extracts ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Checkerboard Assay ◽  
Ethanol Extracts ◽  
Antibiotic Discovery

The alarming rise in the incidences of multidrug-resistant microorganisms and the decline innew antibiotic discovery make the search for new antimicrobial agents or efforts at restoring the activity of older antibiotics to which the microbes have developed resistance very necessary. The aim of the present study is to investigate the antimicrobial and modulation effects of the 70% ethanol extracts of Lannea schimperi, Commelina nudiflora and Piliostigma reticulatum against usceptible strains of microorganisms. Using the broth microdilution method, the minimum inhibitory concentrations (MICs) of the extracts were determined. The checkerboard assay was used to determine the modulation effects when sub-inhibitory concentrations of plant extracts were combined with the standard antibiotics. All three plants extracts possessed weak antimicrobial effects. For the modulation experiments, fifteen of the twenty-seven combinatorial casesyielded biologically significant effects. The ethanol extracts of the three plants studied here are good modulators as they reduced the MIC of ciprofloxacin and ketoconazole by factors that are comparable to that of reserpine. However the exact compounds and their exact mechanism of modulation require further investigation.Keywords: Anti-infective, modulation, Lannea schimperi, Commelina nudiflora, Piliostigmareticulatum, ethnomedicine

scholarly journals Comparison of Broth Microdilution Method UsingHaemophilus Test Medium and Agar Dilution Method for Susceptibility Testing of Eikenella corrodens

1998 ◽  
Vol 36 (8) ◽  
pp. 2386-2388 ◽  
Author(s):  
Luis Alcalá ◽  
Fernando García-Garrote ◽  
Emilia Cercenado ◽  
Teresa Peláez ◽  
Gema Ramos ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Broth Microdilution ◽  
Test Medium ◽  
Eikenella Corrodens ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Agar Dilution

Susceptibility testing of Eikenella corrodens is usually performed by a Mueller-Hinton sheep blood agar dilution (AD) method. However, this method is impractical for testing only a few strains. We compared AD with the broth microdilution method usingHaemophilus test medium (HTM) in order to determine the susceptibility of 36 clinical isolates of E. corrodens to eight antimicrobial agents. MICs obtained by the HTM method yielded 95.5 and 84% agreement (within 2 and 1 log2 dilutions, respectively) with those obtained by AD. The HTM method with incubation in CO2 for 48 h was highly reproducible and constitutes an easy alternative for antimicrobial susceptibility testing of E. corrodens.

scholarly journals Susceptibility of bacteria of the Enterococcus genus isolated on Lithuanian poultry farms

2010 ◽  
Vol 54 (No. 12) ◽  
pp. 583-588 ◽  
Author(s):  
M. Ruzauskas ◽  
R. Siugzdiniene ◽  
V. Spakauskas ◽  
J. Povilonis ◽  
V. Seputiene ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Broth Microdilution ◽  
Diagnostic Systems ◽  
Microtitre Plate ◽  
Predominant Species ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Poultry Farms ◽  
Clinical Breakpoints

The aim of this study was to test and analyse the antimicrobial susceptibility of <I>Enterococcus</I> isolates from Lithuanian poultry farms. Investigations were carried out during the years 2008–2009. The sampling sites, located all over the country, included eight poultry farms of large capacity. All samples were collected from broilers. <I>Enterococcus</I> spp. were isolated from intestines immediately after slaughtering. A total of 160 samples were collected, 20 samples from each farm. The MICs (Minimum Inhibitory Concentrations) of eleven antimicrobial agents were determined for each of the isolates using the broth microdilution method with specific microtitre plate panels (Trek Diagnostic Systems, Inc.). Susceptibility according to clinical breakpoints of chloramphenicol, linezolid, erythromycin, penicillin, quinupristin/dalfopristin, tetracycline, vancomycin, ciprofloxacin and nitrofurantoin was evaluated. One hundred and forty seven samples (92%) from a total of 160 tested samples were positive for <I>Enterococcus</I> spp., however, only 74 strains were selected as non-duplicate isolates. The most predominant species were identified as <I>E. faecium</I> (38%), <I>E. faecalis</I> (17.5%), <I>E. gallinarum</I> (12%) and <I>E. casseliflavus</I> (12%). The most frequent resistance properties were resistances to tetracycline (75.6%), erythromycin (56.8%) and ciprofloxacin (41.9%). No strains resistant to vancomycin and linezolid were found. High percentages of susceptibility to chloramphenicol (82.4%) and penicillin (71.6%) were also observed. A high MIC of tigecycline (≥ 1 mg/l) to 12.2% of enterococci was determined during this study. 44.6% of tested strains had a high MIC (≥ 64 mg/l) to tylosin. There was no significant correlation found between resistances of different species to different antimicrobial agents <I>in vitro</I>.

scholarly journals Antimicrobial Susceptibility of Bacteria Isolated from Orthopedic Implants following Revision Hip Surgery

1998 ◽  
Vol 42 (11) ◽  
pp. 3002-3005 ◽  
Author(s):  
Michael M. Tunney ◽  
Gordon Ramage ◽  
Sheila Patrick ◽  
James R. Nixon ◽  
Philip G. Murphy ◽  
...  
Keyword(s):  
Bone Cement ◽  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Orthopedic Implants ◽  
Hip Surgery ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Revision Hip Surgery

The susceptibilities of 49 isolates recovered from orthopedic implants to seven antimicrobial agents were evaluated by the broth microdilution method. Ciprofloxacin and vancomycin were more active than gentamicin, representing aminoglycosides which are routinely incorporated into bone cement, and also more active than the peroperative antimicrobial agents cefamandole and erythromycin. The use of ciprofloxacin and vancomycin in vivo, therefore, warrants further evaluation.

In vitro activities of acetylmidecamycin and other antimicrobials against human macrolide-resistant Mycoplasma pneumoniae isolates

2020 ◽  
Vol 75 (6) ◽  
pp. 1513-1517 ◽  
Author(s):  
Na Wang ◽  
Yunheng Zhou ◽  
Hong Zhang ◽  
Yang Liu
Keyword(s):  
Mycoplasma Pneumoniae ◽  
Antimicrobial Agents ◽  
Mycoplasma Hominis ◽  
Clinical Isolates ◽  
Mycoplasma Species ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Ureaplasma Spp

Abstract Objectives To assess the in vitro activities of acetylmidecamycin, a 16-membered macrolide, and 11 other antimicrobial agents against human mycoplasmas. Methods A total of 187 clinical isolates, Mycoplasma pneumoniae (n = 110), Mycoplasma hominis (n = 26) and Ureaplasma species (n = 51), were included in this study. The MICs of 12 antimicrobial agents, including acetylmidecamycin, thiamphenicol, chloramphenicol and some other macrolides, fluoroquinolones and tetracyclines, for these clinical isolates were determined by the broth microdilution method. Results For M. pneumoniae, the MIC90 values of the tested macrolides were: acetylmidecamycin (1 mg/L)&lt;josamycin (4 mg/L)&lt;midecamycin (8 mg/L)&lt;azithromycin (16 mg/L)&lt;erythromycin (&gt;128 mg/L). Thiamphenicol and chloramphenicol had the same MIC90 (2 mg/L). For Ureaplasma species, the MIC90 values were: acetylmidecamycin (0.25 mg/L)&lt;josamycin (0.5 mg/L)=midecamycin&lt;azithromycin (1 mg/L)=erythromycin. Chloramphenicol had a lower MIC90 (2 mg/L) than that of thiamphenicol (4 mg/L). For M. hominis, the MIC90 values were: acetylmidecamycin (0.25 mg/L)&lt;josamycin (0.5 mg/L)&lt;midecamycin (2 mg/L)&lt;azithromycin (&gt;128 mg/L)=erythromycin. The MIC90 values of chloramphenicol and thiamphenicol were 2 and 4 mg/L, respectively. Conclusions The results indicated that acetylmidecamycin and thiamphenicol are active in vitro against the most common mycoplasma species infecting humans, including those resistant to macrolides and fluoroquinolones. Acetylmidecamycin and thiamphenicol might be a promising option for clinicians to treat infections caused by Mycoplasma and Ureaplasma spp., particularly macrolide-resistant M. pneumoniae in paediatrics and fluoroquinolone-resistant M. hominis in adults. Further investigation of their clinical roles in treating infections caused by these organisms is warranted.

scholarly journals Comparison of the Susceptibilities of Burkholderia pseudomallei to Meropenem and Ceftazidime by Conventional and Intracellular Methods

2004 ◽  
Vol 48 (8) ◽  
pp. 2999-3005 ◽  
Author(s):  
T. J. J. Inglis ◽  
F. Rodrigues ◽  
P. Rigby ◽  
R. Norton ◽  
B. J. Currie
Keyword(s):  
Clinical Outcomes ◽  
Burkholderia Pseudomallei ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Bacterial Count ◽  
In Vitro Test ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method

ABSTRACT The effect of the two antibiotics ceftazidime and meropenem on a collection of 46 Burkholderia pseudomallei isolates representing clinical and environmental sources across northern Australia was investigated by using a series of in vitro test methods. The susceptibility testing methods used included Kirby-Bauer disk diffusion, Etest MIC, broth microdilution MIC, and a modification of the microdilution method in which Acanthamoeba cells were added to simulate the effect of a professional phagocytic cell on test outcome. In a semiquantitative validation coculture series, the majority of bacteria were intracellular up to a multiplicity of infection of 10 bacteria to one ameba. The optical density and bacterial count (log10 CFU/ml) correlated across the range tested (r 2 = 0.77; P < 0.0001). Susceptibility test results were compared against clinical outcomes. The MICs of ceftazidime were consistently higher than those of meropenem by all three methods. The MICs of both agents were significantly higher when Acanthamoeba trophozoites were added to the broth microdilution method. Conventional and intracellular MIC results were consistent for clinical isolates from the Western Australian outbreak cluster despite the wide variety of clinical outcomes. Further development of the intracellular MIC method is expected to help assess the efficacy of antimicrobial agents on this bacterial species in an intracellular setting.

Antimicrobial Essential Oil Combinations to Combat Foot Odour

Planta Medica ◽  
2018 ◽  
Vol 84 (09/10) ◽  
pp. 662-673 ◽  
Author(s):  
Ané Orchard ◽  
Alvaro Viljoen ◽  
Sandy van Vuuren
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oil ◽  
Essential Oils ◽  
Antimicrobial Efficacy ◽  
Juniperus Virginiana ◽  
Broth Microdilution ◽  
Synergistic Interactions ◽  
Microdilution Method ◽  
Broth Microdilution Method

AbstractFoot odour (bromodosis) is an embarrassing and perplexing condition mostly caused by bacteria of the Brevibacterium species. Essential oils are a credible option as an affordable treatment of odour and contribute towards antimicrobial efficacy. Therefore, this study sets out to investigate the antimicrobial activity of essential oil combinations against odour-causing bacteria. The broth microdilution method was used to investigate the antimicrobial activity of 119 essential oil combinations, and the fractional inhibitory index was calculated to determine the interactive profile. Combinations that resulted in synergy in 1 : 1 ratios were further evaluated in different concentrations, and isobolograms were plotted to determine the influence of the ratio on overall activity. Numerous combinations could be identified as having synergistic interactions against the Brevibacterium spp. and no antagonism was observed. The combination of Juniperus virginiana (juniper) and Styrax benzoin (benzoin) demonstrated synergy against all three Brevibacterium spp. tested and J. virginiana was the essential oil responsible for the majority of the synergistic interactions. The results reported here confirm the promising potential of the majority of these oils and selected combinations in treating and controlling bromodosis.

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