scholarly journals In Vitro Activity of Ceftiofur and its Primary Metabolite, Desfuroylceftiofur, against Organisms of Veterinary Importance

1996 ◽  
Vol 8 (3) ◽  
pp. 332-336 ◽  
Author(s):  
Sarah A. Salmon ◽  
Jeffrey L. Watts ◽  
Robert J. Yancey
Keyword(s):  
Susceptibility Testing ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Salmonella Spp ◽  
Primary Metabolite ◽  
Highly Active ◽  
Veterinary Importance ◽  
Gram Negative Organisms ◽  
Serial Dilutions

Ceftiofur (XNL) and its primary metabolite, desfuroylceftiofur (DXNL), were evaluated for in vitro activity against 539 isolates from veterinary sources. Actinobacillus pleuropneumoniae, Pasteurella spp., Haemophilus somnus, Salmonella spp., Escherichia coli, staphylococci, and streptococci were tested. Overall, XNL and DXNL were equivalent in activity against the gram-negative organisms with all minimum inhibitory concentrations (MICs) within 1 serial dilution. Against the staphylococci, MIC differences of 2–3 serial dilutions were detected with an MIC90 for XNL and DXNL of 1.0 and 4.0–8.0 g/ml, respectively. Although the MIC90 obtained for Streptococcus suis for each compound was within 1 dilution, the MIC values against individual strains were 2–3 dilutions greater for DXNL than for XNL. The MICs obtained with the bovine and equine streptococci for DXNL (MIC90 = 0.03 g/ml) were 5 serial dilutions higher than those obtained for XNL (MIC90 £ 0.0019). Although DXNL was less active than XNL against the streptococci, these differences were not clinically important because both XNL and DXNL were highly active for these bacteria. Although these differences are of little importance with the streptococci, they may have important implications for susceptibility testing of the staphylococci. In conclusion, with the exception of the staphylococci, both XNL and DXNL were highly active against the organisms tested, with MICs for both compounds several fold lower than plasma levels achieved during dosing of XNL.

scholarly journals In Vitro Activity of Cefepime against Multidrug-Resistant Gram-Negative Bacilli, Viridans Group Streptococci andStreptococcus pneumoniaefrom a Cross-Canada Surveillance Study

1999 ◽  
Vol 10 (2) ◽  
pp. 122-127 ◽  
Author(s):  
Donald E Low ◽  
Joyce de Azavedo ◽  
Canadian Bacterial Surveillance Network ◽  
Ross Davidson
Keyword(s):  
Susceptibility Testing ◽  
Multidrug Resistant ◽  
Vitro Activity ◽  
Surveillance Study ◽  
National Committee ◽  
In Vitro Activity ◽  
Gram Negative ◽  
Resistance Rates ◽  
Viridans Group Streptococci

OBJECTIVE: To determine the in vitro activity of cefepime against multidrug-resistant Gram-negative bacilli and Gram-positive cocci obtained from an ongoing cross-Canada surveillance study.DESIGN: Clinical isolates of aerobic Gram-negative bacilli with inducible and constitutive chromosomally mediated cephalosporinases, viridans group streptococci andStreptococcus pneumoniaewere collected from laboratories serving hospitals, nursing homes and physician offices in the community from across Canada during 1996 and 1997. Laboratories were asked to submit only clinically relevant nonduplicate isolates for susceptibility testing. In vitro antimicrobial susceptibility testing was carried out on all isolates of Gram-negative and viridans group streptococci.S pneumoniaewere characterized as penicillin susceptible, intermediately resistant or highly resistant. Nonsusceptible isolates were defined as being intermediately or highly resistant (minimal inhibitory concentrations [MIC] greater than 0.06 mg/L). Only isolates ofS pneumoniaethat were nonsusceptible to penicillin were selected for further study. MICs were determined using a microbroth dilution technique according to the National Committee of Clinical Laboratory Standards.RESULTS: A total of 727 Gram-negative bacilli samples were collected. No resistance to cefepime was detected withCitrobacter freundii,Serratia marcescens,Morganella morganiiandEnterobacterspecies. Of these strains,Enterobacterspecies andC freundiiwere the most resistant to ceftazidime, cefotaxime and ceftriaxone with MIC90Sof 32 mg/L or greater and resistance rates of 6% or greater. Resistance rates ofPseudomonas aeruginosaandAcinetobacterspecies to cefepime were 4.8% and 3%, respectively. The two organisms had similar rates of resistance to ceftazidime. Less than 3% of the Gram-negative bacilli were resistant to imipenem and meropenem. There were 153 viridans group streptococci, of which 22 (14.4%) were resistant to penicillin. Of 1287S pneumoniaesamples, 193 (15%) were nonsusceptible to penicillin. Cefepime, ceftriaxone and cefotaxime had comparable activity against all isolates of viridans group streptococci andS pneumoniae.CONCLUSIONS: Cefepime demonstrated excellent in vitro activity against Gram-negative bacilli with inducible and constitutive chromosomally mediated cephalosporinases, and had equal or superior activity versus comparator beta-lactams against all isolates of viridans group streptococci andS pneumoniae.

In vitro activity of olorofim against clinical isolates of Scedosporium species and Lomentospora prolificans using EUCAST and CLSI methodologies

2020 ◽  
Vol 75 (12) ◽  
pp. 3582-3585
Author(s):  
Olga Rivero-Menendez ◽  
Manuel Cuenca-Estrella ◽  
Ana Alastruey-Izquierdo
Keyword(s):  
Amphotericin B ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Scedosporium Apiospermum ◽  
In Vitro Activity ◽  
Scedosporium Dehoogii ◽  
Scedosporium Species

Abstract Objectives To evaluate the in vitro activity of olorofim, a new broad-spectrum antifungal with a novel mechanism of action, against a collection of 123 Spanish clinical isolates belonging to five Scedosporium species and Lomentospora prolificans. Methods The activity of olorofim against Scedosporium apiospermum (n = 30), Scedosporium boydii (n = 30), Scedosporium ellipsoideum (n = 10), Scedosporium aurantiacum (n = 20), Scedosporium dehoogii (n = 3) and Lomentospora prolificans (n = 30) was compared with that of amphotericin B, voriconazole, isavuconazole and micafungin by performing EUCAST and CLSI reference methods for antifungal susceptibility testing. Results Amphotericin B and isavuconazole showed MICs ≥2 mg/L for all the species evaluated and voriconazole was moderately active (GM, MIC50 and MIC90 values ≤2 mg/L) against all of them except L. prolificans. Micafungin was effective against S. apiospermum complex strains, but exhibited elevated MECs for S. dehoogii and S. aurantiacum. Olorofim showed low MICs for all the Scedosporium strains tested (GM values were lower than 0.130 and 0.339 by the EUCAST method and the CLSI method, respectively, for all of the species), including those belonging to the MDR species L. prolificans, for which GM values were 0.115 and 0.225 mg/L by the EUCAST method and the CLSI method, respectively, while the GMs for the rest of the antifungals evaluated were higher than 3.732 mg/L using both methodologies. Conclusions Olorofim displayed promising in vitro activity against the Scedosporium and L. prolificans strains tested, some of which have reduced susceptibility to the antifungals that are currently in use.

In Vitro Activity of Tosufloxacin against Pseudomonas pseudomallei, Salmonella spp. and Other Enterobacteriaceae

Drugs ◽  
1995 ◽  
Vol 49 (Supplement 2) ◽  
pp. 260
Author(s):  
S. Srimuang ◽  
V. Fugpholngam ◽  
K. Asvanich ◽  
A. Chongchitmate ◽  
D. Tanphaichitra
Keyword(s):  
Vitro Activity ◽  
In Vitro Activity ◽  
Salmonella Spp ◽  
Pseudomonas Pseudomallei

scholarly journals In vitro activity of premafloxacin, a new extended-spectrum fluoroquinolone, against pathogens of veterinary importance.

1997 ◽  
Vol 41 (5) ◽  
pp. 1190-1192 ◽  
Author(s):  
J L Watts ◽  
S A Salmon ◽  
M S Sanchez ◽  
R J Yancey
Keyword(s):  
Antimicrobial Agents ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Gram Negative ◽  
Extended Spectrum ◽  
Veterinary Importance

The in vitro activity of premafloxacin against 673 veterinary pathogens was evaluated. Premafloxacin was equivalent to ciprofloxacin, enrofloxacin, and danofloxacin in activity against the gram-negative bacilli but was much more active (MIC for 90% of the strains tested [MIC90], 0.015 to 0.25 microg/ml) than the comparison antimicrobial agents (MIC90, 0.13 to 16.0 microg/ml) against the staphylococci, streptococci, and anaerobes tested.

scholarly journals In Vitro Activity of the Histatin Derivative P-113 against Multidrug-Resistant Pathogens Responsible for Pneumonia in Immunocompromised Patients

2005 ◽  
Vol 49 (3) ◽  
pp. 1249-1252 ◽  
Author(s):  
Andrea Giacometti ◽  
Oscar Cirioni ◽  
Wojciech Kamysz ◽  
Giuseppina D'Amato ◽  
Carmela Silvestri ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Vitro Activity ◽  
Immunocompromised Patients ◽  
In Vitro Activity ◽  
Beta Lactams ◽  
Gram Negative ◽  
Resistant Strains ◽  
Multidrug Resistant Pathogens ◽  
Gram Negative Organisms

ABSTRACT The in vitro activity of the histatin derivative P-113, alone or combined with eight antibiotics, was investigated against multidrug-resistant strains isolated from clinical specimens of immunocompromised patients with pneumonia. The gram-negative isolates were susceptible to P-113. S. aureus showed less susceptibility. Synergy was demonstrated when P-113 was combined with beta-lactams against gram-negative organisms.

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