P87 Daptomycin activity against a wide range of coagulase-negative staphylococci and assessment of agar dilution method for determination of daptomycin MICs

2009 ◽  
Vol 34 ◽  
pp. S54-S55
Author(s):  
M. John ◽  
S. Milburn ◽  
D. Diagre ◽  
B. Wilson ◽  
R. Lannigan ◽  
...  
2008 ◽  
Vol 3 (9) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Mehrdad Iranshahi ◽  
Abdolmajid Fata ◽  
Bahareh Emami ◽  
Bibi Mohadeseh Jalalzadeh Shahri ◽  
Bibi Sedigheh Fazly Bazzaz

The increase in dermatophytoses and the fact that some patients do not respond well to therapy make it necessary to find new antifungal agents. As part of our ongoing studies on medicinal plants from Iran, we studied antidermatophytic activities of Ferula latisecta essential oil, which had shown considerable antifungal activity in preliminary antimicrobial screening. Antifungal activity was evaluated by determination of MIC values using the agar dilution method on type strains of Candida albicans and dermatophytes. The composition of the oil was characterized by GC and GC/MS analyses. The essential oil was rich in polysulfides (75.2%) and exhibited good activity against Trichophyton rubrum and T. verrucosom for about three weeks, with a MIC value 96 μg/mL. The oil showed antifungal activity, especially against dermatophytes, and the activity is probably related to the sulfur-containing components of the oil. This study has identified that the polysulfides-rich essential oil of Ferula latisecta fruits has activity against a range of human pathogenic dermatophytes, justifying future clinical trials to validate its use as a therapeutic alternative for dermatophytosis.


2000 ◽  
Vol 38 (2) ◽  
pp. 752-754 ◽  
Author(s):  
Zafar Hussain ◽  
Luba Stoakes ◽  
Viki Massey ◽  
Deb Diagre ◽  
Viivi Fitzgerald ◽  
...  

The National Committee for Clinical Laboratory Standards has recently changed the oxacillin breakpoint from ≥4 mg/liter to ≥0.5 mg/liter to detect methicillin-resistant coagulase-negative staphylococci (CoNS) because the previous breakpoint lacked sensitivity. To determine the correlation between the new oxacillin breakpoint and the presence of themecA gene, 493 CoNS of 11 species were tested. The presence of the mecA gene was determined by PCR, and oxacillin susceptibility was determined by the agar dilution method with Mueller-Hinton agar containing 2% NaCl and oxacillin (0.125 to 4.0 mg/liter). The new breakpoint correctly classified all CoNS strains with mecA as methicillin resistant and strains ofStaphylococcus epidermidis, S. haemolyticus, and S. hominiswithout mecA as methicillin susceptible. The breakpoint of ≥0.5 mg/liter was not specific for S. cohnii, S. lugdunensis, S. saprophyticus, S. warneri, and S. xylosus, in that it categorized 70 of 74 strains of these species withoutmecA (94.6%) as methicillin resistant. The results of this study indicate that the new oxacillin breakpoint accurately identifies strains of CoNS with mecAbut is not specific for strains of certain species of CoNS withoutmecA.


2005 ◽  
Vol 49 (7) ◽  
pp. 2997-3000 ◽  
Author(s):  
K. Van den Bulck ◽  
A. Decostere ◽  
I. Gruntar ◽  
M. Baele ◽  
B. Krt ◽  
...  

ABSTRACT The susceptibilities of Helicobacter felis (15 strains), H. bizzozeronii (7 strains), and H. salomonis (3 strains) to 10 antimicrobial agents were investigated by determination of the MIC using the agar dilution method. No consistent differences were noticed between the different Helicobacter species, which were all highly susceptible to ampicillin, clarithromycin, tetracycline, tylosin, enrofloxacin, gentamicin, and neomycin, as demonstrated by low MICs. Higher MICs were obtained for lincomycin (up to 8 μg/ml) and spectinomycin (up to 4 μg/ml). Two H. felis strains showed a MIC of 16 μg/ml for metronidazole, suggesting acquired resistance to this antimicrobial agent.


2008 ◽  
Vol 1 (2) ◽  
pp. 139-146 ◽  
Author(s):  
M. dos Santos Oliveira ◽  
E. Badiale Furlong

The antifungal and antimycotoxigenic activities of extracts from edible plants were tested by the agar dilution method using the growth diameter of Aspergillus flavus as response and the determination of aflatoxins B1 and B2 in the culture medium. On the 7th incubation day, the greatest fungal inhibitions were reached by the extracts from potato peel; rice and wheat; lemon peel and pulp; eggplant peel; orange peel and pulp; and apple pulp. After the 14-day incubation, the extracts from banana (30 µg phenol/ml agar), eggplant (30 µg phenol/ml agar), and potato (50 and 67 µg phenol/ml agar) pulp reduced the production of aflatoxin B1 by 3.2%/µg phenol/ml agar, 2.9%/µg phenol/ml agar, 1.8%/µg phenol/ml agar and 0.85%/µg phenol/ml agar, respectively, in relation to the control. The extracts from the other vegetables fully inhibited the synthesis of the mycotoxin. These results point to the studied plants and their residues as potential sources of phenolic compounds that may have an inhibitory effect on fungal development and the production of mycotoxins in food.


1997 ◽  
Vol 41 (4) ◽  
pp. 841-843 ◽  
Author(s):  
S A Radford ◽  
E M Johnson ◽  
D W Warnock

The in vitro activity of voriconazole was compared with that of itraconazole. Eighty-six isolates of pathogenic molds belonging to 23 species were tested by an agar dilution method in High Resolution medium. Voriconazole was more active than itraconazole against a number of hyaline molds, including several Fusarium spp. and Scedosporium prolificans. Voriconazole and itraconazole showed comparable good activity against several hyaline molds, including Penicillium marneffei and Scedosporium apiospermum, and a number of dematiaceous molds, including Bipolaris australiensis, Cladophialophora bantiana, several Exophiala spp., and several Fonsecaea spp. Our results suggest that voriconazole could be effective against a wide range of mold infections in humans.


2006 ◽  
Vol 50 (8) ◽  
pp. 2680-2685 ◽  
Author(s):  
Olivier Denis ◽  
Ariane Deplano ◽  
Claire Nonhoff ◽  
Marie Hallin ◽  
Raf De Ryck ◽  
...  

ABSTRACT The in vitro activities of 22 antimicrobial agents, including ceftobiprole, daptomycin, and tigecycline, against 511 methicillin-resistant Staphylococcus aureus (MRSA) isolates from 112 Belgian hospitals were studied by using the CLSI agar dilution method. Isolates were characterized by pulsed-field gel electrophoresis (PFGE) analysis and by PCR detection of determinants of resistance to aminoglycosides, macrolides-lincosamides-streptogramins, and tetracyclines. A representative set of isolates with different PFGE genotypes was further characterized by multilocus sequence typing, determination of staphylococcal cassette chromosome mec (SCCmec) type, and multiplex PCR for toxic shock syndrome type 1 (TSST-1) and Panton-Valentine leukocidin genes. MRSA isolates belonged to nine epidemic MRSA clones, of which sequence type 45 (ST45)-SCCmec IV and ST8-SCCmec IV were predominant, accounting for 49 and 20% of isolates, respectively. The distribution of antimicrobial resistance and TSST-1 genes was strongly linked to clonal types. Ceftobiprole, daptomycin, and tigecycline showed high activity against all isolates of these sporadic and epidemic MRSA clones, as indicated by MIC90s of 2 mg/liter, 0.5 mg/liter, and 0.25 mg/liter, respectively. The MIC distribution of daptomycin and tigecycline was not different in isolates with decreased susceptibility to glycopeptides or tetracyclines, respectively. Ceftobiprole MICs were not correlated with oxacillin and cefoxitin MICs. These data indicate excellent activity of the newly developed agents ceftobiprole, daptomycin, and tigecycline against MRSA isolates recently recovered from hospitalized patients in Belgium, supporting their therapeutic potential for nosocomial MRSA infections.


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