In vitro activity of imazalil against Penicillium expansum: Comparison of the CLSI M38-A broth microdilution method with traditional techniques

2009 ◽  
Vol 129 (1) ◽  
pp. 26-29 ◽  
Author(s):  
R CABANAS ◽  
M ABARCA ◽  
M BRAGULAT ◽  
F CABANES
1997 ◽  
Vol 41 (5) ◽  
pp. 1156-1157 ◽  
Author(s):  
O Uzun ◽  
S Kocagöz ◽  
Y Cetinkaya ◽  
S Arikan ◽  
S Unal

The in vitro activity of LY303366, a new echinocandin derivative, was evaluated with 191 yeast isolates by a broth microdilution method. The MICs at which 50% of the isolates were inhibited were 0.125 microg/ml for Candida albicans and C. tropicalis, 0.25 microg/ml for C. krusei, C. kefyr, and C. glabrata, and 2.0 microg/ml for C. parapsilosis.


2019 ◽  
Author(s):  
H. Selcuk Ozger ◽  
Tugba Cuhadar ◽  
Serap Suzuk Yildiz ◽  
Zehra Demirbas Gulmez ◽  
Murat Dizbay ◽  
...  

AbstractThe synergistic activity of eravacycline in combination with colistin on carbapenem-resistant A.baumannii (CRAB) isolates was evaluated in this study. Minimum inhibitory concentrations (MICs) of eravacycline and colistin were determined by the broth microdilution method. MICs values ranged between 1 to 4 mg and 0,5 to 128 mg/L for eravacycline and colistin, respectively. In-vitro synergy between eravacycline and colistin was evaluated by using the chequerboard methodology. Synergistic activity was found in 10 % of the strains, and additive effect in 20 %. No antagonism was detected. Similar activity was also observed in colistin resistant CRAB isolates. The result of this study indicates that eravacycline and colistin combination may be a potential therapeutic option for the treatment of CRAB related infections.


2000 ◽  
Vol 44 (1) ◽  
pp. 226-229 ◽  
Author(s):  
Francesco Barchiesi ◽  
Daniela Arzeni ◽  
Annette W. Fothergill ◽  
Luigi Falconi Di Francesco ◽  
Francesca Caselli ◽  
...  

ABSTRACT A broth microdilution method performed in accordance with the National Committee for Clinical Laboratory Standards guidelines was used to compare the in vitro activity of the new antifungal triazole SCH 56592 (SCH) to that of fluconazole (FLC), itraconazole (ITC), and ketoconazole (KETO) against 257 clinical yeast isolates. They included 220 isolates belonging to 12 different species of Candida, 15 isolates each of Cryptococcus neoformans andSaccharomyces cerevisiae, and seven isolates ofRhodotorula rubra. The MICs of SCH at which 50% (MIC50) and 90% (MIC90) of the isolates were inhibited were 0.06 and 2.0 μg/ml, respectively. In general, SCH was considerably more active than FLC (MIC50 and MIC90 of 1.0 and 64 μg/ml, respectively) and slightly more active than either ITC (MIC50 and MIC90 of 0.25 and 2.0 μg/ml, respectively) and KETO (MIC50 and MIC90 of 0.125 and 4.0 μg/ml, respectively). Our in vitro data suggest that SCH has significant potential for clinical development.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S310-S311 ◽  
Author(s):  
Olga Lomovskaya ◽  
Jill Lindley ◽  
Debora Rubio-Aparicio ◽  
Kirk J Nelson ◽  
Mariana Castanheira

Abstract Background QPX7728 (QPX) is a novel broad-spectrum boron-containing inhibitor of serine- and metallo-β-lactamases (MBLs). We evaluated the in vitro activity of QPX combined with several β-lactams against carbapenem-resistant AB (CRAB) and PSA clinical isolates with varying β-lactam resistance mechanisms. Methods A total of 503 CRAB (meropenem [MEM] MIC ≥8 µg/mL) and 762 PSA clinical isolates were tested by the reference broth microdilution method against β-lactams alone and combined with QPX (4 µg/mL and 8 µg/mL). PSA isolates were selected to represent the normal distribution of MEM, ceftazidime–avibactam (CAZ-AVI), and ceftolozane-tazobactam (TOL-TAZ) resistance according to 2017 surveillance data (representative panel). Additionally, 262 PSA isolates that were either nonsusceptible (NS) to MEM (MIC, ≥4 µg/mL) or to TOL-TAZ (MIC, ≥8 µg/mL), or resistant (R) to CAZ-AVI (MIC, ≥16 µg/mL) (challenge panel) were also tested. Within this 262 strain challenge set, 56 strains carried MBLs and the majority also had nonfunctional OprD. Results Against CRAB, QPX at 4 and 8 µg/mL increased the potency of all β-lactams tested. MEM-QPX was the most potent combination (table) displaying MIC50/MIC90 at 1/8 and 0.5/4 µg/mL with QPX at fixed 4 and 8 µg/mL, respectively. Susceptibility (S) to MEM was restored in >95% of strains. Against the 500 PSA from the representative panel, S for all QPX combinations was >90%. For the challenge panel, TOL-QPX and piperacillin (PIP)-QPX were the most potent combinations, restoring S in 76–77% of strains. TOL-QPX and MEM-QPX or cefepime (FEP)-QPX restored the MIC values to S rates when applying the CLSI breakpoint for the compound alone (comparison purposes only) in ~90% and ~75% of non-MBL-producing strains, respectively, vs. 60–70% for TOL-TAZ and CAZ-AVI. PIP-QPX reduce the MIC values to S values for PIP-TAZ in ~60% of MBL-producing strains vs. 20–30% and 3–7% for other QPX combinations and non-QPX tested combinations, respectively. Conclusion Combinations of QPX with various β-lactam antibiotics displayed potent activity against CRAB and resistant PSA isolates and warrant further investigation. Disclosures All authors: No reported disclosures.


1996 ◽  
Vol 40 (9) ◽  
pp. 2142-2146 ◽  
Author(s):  
K V Singh ◽  
T M Coque ◽  
B E Murray

The in vitro activity of the trinem sanfetrinem (formerly GV104326) (GV) was compared with that of vancomycin, ampicillin, and/or nafcillin against 287 gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and multiresistant enterococci, by the agar and microbroth dilution methods. GV demonstrated 2 to 16 times more activity than ampicillin and nafcillin against the majority of these organisms. The MIC range of GV was 16 to 64 micrograms/ml for 19 Enterococcus faecium strains that were highly resistant to ampicillin (ampicillin MIC range, 64 to 512 micrograms/ml) and vancomycin resistant and 0.25 to 32 micrograms/ml for resistant Rhodococcus spp. Similar activities (+/-1 dilution) were observed by either the agar or the broth microdilution method. GV demonstrated bactericidal activity against a beta-lactamase-producing Enterococcus faecalis strain and against two methicillin-susceptible Staphylococcus aureus strains in 10(5)-CFU/ml inocula. Synergy between GV and gentamicin was observed against an E. faecalis strain that lacked high-level gentamicin resistance. The activity of GV suggests this compound warrants further study.


2017 ◽  
Vol 62 (1) ◽  
Author(s):  
Meredith A. Hackel ◽  
Olga Lomovskaya ◽  
Michael N. Dudley ◽  
James A. Karlowsky ◽  
Daniel F. Sahm

ABSTRACT Vaborbactam (formerly RPX7009) is a novel inhibitor of serine β-lactamases, including Ambler class A carbapenemases, such as KPCs. The current study evaluated the in vitro activity of the combination agent meropenem-vaborbactam against a global collection of 991 isolates of KPC-positive Enterobacteriaceae collected in 2014 and 2015 using the Clinical and Laboratory Standards Institute (CLSI) standard broth microdilution method. The MIC90 of meropenem (when tested with a fixed concentration of 8 μg/ml of vaborbactam) for isolates of KPC-positive Enterobacteriaceae was 1 μg/ml, and MIC values ranged from ≤0.03 to >32 μg/ml; 99.0% (981/991) of isolates had meropenem-vaborbactam MICs of ≤4 μg/ml, the U.S. FDA-approved MIC breakpoint for susceptibility to meropenem-vaborbactam (Vabomere). Vaborbactam lowered the meropenem MIC50 from 32 to 0.06 μg/ml and the MIC90 from >32 to 1 μg/ml. There were no differences in the activity of meropenem-vaborbactam when the isolates were stratified by KPC variant type. We conclude that meropenem-vaborbactam demonstrates potent in vitro activity against a worldwide collection of clinical isolates of KPC-positive Enterobacteriaceae collected in 2014 and 2015.


2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S374-S375 ◽  
Author(s):  
Helio S Sader ◽  
Mariana Castanheira ◽  
Jennifer M Streit ◽  
Leonard R Duncan ◽  
Robert K Flamm

Abstract Background Zidebactam (ZID), a bicyclo-acyl hydrazide, is a β-lactam enhancer with a dual mechanism of action involving selective and high binding affinity to Gram-negative (GN) PBP2 and β-lactamase inhibition. We evaluated the in vitro activity of cefepime (FEP) combined with ZID against GN organisms causing bloodstream infections (BSI) in hospitals worldwide. Methods A total of 2,094 isolates from 105 medical centers were evaluated. Isolates were collected from Europe (1,050), USA (331), Latin America (LA; 200) and the Asia-Pacific region (AP; 393) in 2015, and China (120) in 2013 by the SENTRY Program. Susceptibility (S) testing was performed by reference broth microdilution method against FEP-ZID (1:1 ratio) and comparators. The collection included 1,809 Enterobacteriaceae (ENT), 170 P. aeruginosa (PSA) and 115 Acinetobacter spp. (ASP). Results FEP-ZID was very active against ENT (MIC50/90 of ≤0.03/0.12 μg/mL) with 99.9 and 100.0% of isolates inhibited at ≤4/4 and ≤8/8 μg/mL, respectively, and retained potent activity against carbapenem-resistant (CRE; n = 44; MIC50/90, 1/4 μg/mL), multidrug-resistant (MDR), and extensively drug-resistant (XDR) isolates (Table). Amikacin (AMK; MIC50/90, 2/4 μg/mL; 97.7% S) was also very active against ENT, and colistin (COL; MIC50/90, 0.12/>8 μg/mL) inhibited only 87.3% of isolates at ≤2 μg/mL. FEP-ZID was highly active against PSA, including isolates resistant to other antipseudomonal β-lactams, MDR (MIC50/90, 4/8 μg/mL) and XDR (MIC50/90, 4/8 μg/mL) isolates. Among the comparators, COL (MIC50/90 of ≤0.5/1 μg/mL; 100.0% S) and AMK (MIC50/90, 4/16 μg/mL; 91.2% S) were the most active agents against PSA. FEP-ZID (MIC50/90, 16/32 μg/mL) was 4-fold more active than FEP against ASP. Conclusion FEP-ZID (WCK 5222) exhibited potent in vitro activity against a large worldwide collection of GN isolates from BSI, including MDR and XDR isolates. These results support further clinical development of WCK 5222 for treating BSI. Disclosures H. S. Sader, Wockhardt Bio Ag: Research Contractor, Research grant; M. Castanheira, Wockhardt Bio Ag: Research Contractor, Research grant; J. M. Streit, Wockhardt Bio Ag: Research Contractor, Research grant; L. R. Duncan, Wockhardt Bio Ag: Research Contractor, Research grant; R. K. Flamm, Wock: Research Contractor, Research support


2003 ◽  
Vol 47 (12) ◽  
pp. 3760-3763 ◽  
Author(s):  
James H. Jorgensen ◽  
Sharon A. Crawford ◽  
Cynthia C. Kelly ◽  
Jan E. Patterson

ABSTRACT The increasing prevalence of vancomycin-resistant enterococcal (VRE) infections and the limited number of antimicrobial agents for their treatment emphasize a need for new, more effective agents. In this study, the in vitro activity of daptomycin was determined against a collection of 156 VRE from seven different institutions. Van types were characterized by PCR, and pulsed-field gel electrophoresis was performed to exclude isolates with >85% relatedness by dendrogram. Included were 126 Enterococcus faecium (109 vanA, 17 vanB) isolates, 5 Enterococcus faecalis (3 vanA, 2 vanB) isolates, 2 Enterococcus avium (vanA) isolates, 1 Enterococcus durans (vanA) isolate, 10 Enterococcus gallinarum (vanC1) isolates, and 12 Enterococcus casseliflavus (vanC2) isolates. MICs of daptomycin and five additional agents were determined by the NCCLS broth microdilution method with Mueller-Hinton (MH) broth containing supplemental calcium. MICs were also determined using two investigational E-test strip formulations, and disk diffusion testing was performed by the standard NCCLS method. The MIC of daptomycin at which 50% of the isolates tested were inhibited for this isolate collection was 4 μg/ml, and the MIC at which 90% of the isolates tested were inhibited was 8 μg/ml. Two isolates of vanA E. faecium were resistant to linezolid, and one isolate was resistant to quinupristin-dalfopristin. MICs of daptomycin determined by the E test with and without added calcium varied by 8- to 16-fold, and disk diffusion zones varied by 3 to 6 mm according to the calcium content of the commercial MH agar lots used in the study. This study has shown daptomycin to have good activity against a diverse collection of contemporary VRE isolates. However, improved standardization of the calcium content of MH agar will be important for reliable testing of daptomycin by clinical laboratories using either the E test or disk diffusion methods.


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