scholarly journals Prevalence of Main Gram-Positive Pathogens Causing Bloodstream Infections in United States Medical Centers (2010–2015) and Analysis of Oritavancin In Vitro Activity

2016 ◽  
Vol 3 (suppl_1) ◽  
Author(s):  
Rodrigo E. Mendes ◽  
Helio S. Sader ◽  
Michael D. Huband ◽  
Robert K. Flamm
2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S323-S323
Author(s):  
Helio S Sader ◽  
Rodrigo E Mendes ◽  
Michael A Pfaller ◽  
Robert K Flamm

Abstract Background The management of endocarditis requires aggressive and prolonged antimicrobial treatment. Dalbavancin (DALBA) has demonstrated potent in vitro activity against Gram-positive (GP) organisms commonly responsible for endocarditis and is being evaluated for treatment of complicated bacteremia and infective endocarditis. Methods A total of 626 GP organisms were collected from patients with a diagnosis of bacterial endocarditis in the United States (n = 222) and Europe (n = 404) from 2007 to 2017 via the SENTRY Antimicrobial Surveillance Program and were tested for susceptibility (S) against DALBA and comparators by CLSI broth microdilution. Results The most common organisms were S. aureus (48.4%), E. faecalis (EF; 19.6%), and viridans group streptococci (VGS; 12.5%). DALBA and daptomycin (DAPTO) showed complete activity (100.0%S) against S. aureus, but DALBA MICs were 4- to 8-fold lower (table). Linezolid (LZD) and teicoplanin were also active against all SA; whereas vancomycin (VAN) and trimethoprim–sulfamethoxazole were active against 99.7% of isolates. Ceftaroline (CPT) exhibited potent activity against methicillin-susceptible S. aureus (MSSA; MIC90, 0.25 mg/L; 100.0%S) and inhibited 78.4% of methicillin-resistant S. aureus (MRSA) isolates at ≤1 mg/L. All EF isolates were S to ampicillin, DAPTO, and LZD, whereas 97.6% (120/123) of isolates were S to DALBA (MIC90, 0.06 mg/L) and 96.7%S to VAN (MIC90, 2 mg/L). Against EF, DALBA MIC values were 16- to 32-fold lower than DAPTO and VAN. All VGS and coagulase-negative staphylococcal (CoNS) isolates were S to DALBA, DAPTO, VAN, and LZD, and the highest CPT MICs were 0.5 mg/L for VGS and 4 mg/L for CoNS (93.5% inhibited at ≤1 mg/L). Against E. faecium (EFM), 65.7% of isolates were inhibited at ≤0.25 mg/L of DALBA and 62.9% were VAN-S. All EFM were S to DAPTO and LNZ. β-Hemolytic streptococci (BHS) was S to most antimicrobial agents, and only 66.7% of S. pneumoniae (SPN) isolates were PEN-S at ≤0.06 mg/L. Conclusion DALBA exhibited potent in vitro activity against a large collection of GP isolates recovered from patients with endocarditis in the United States and Europe medical centers. These results support further investigations to determine the role of DALBA in the treatment of infective endocarditis. Disclosures H. S. Sader, Allergan: Research Contractor, Research support. R. E. Mendes, Allergan: Research Contractor, Research support. M. A. Pfaller, Allergan: Research Contractor, Research support. R. K. Flamm, Allergan: Research Contractor, Research support.


2017 ◽  
Vol 23 (6) ◽  
pp. 718-726 ◽  
Author(s):  
Michael A. Pfaller ◽  
Helio S. Sader ◽  
Robert K. Flamm ◽  
Mariana Castanheira ◽  
Jennifer I. Smart ◽  
...  

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S414-S414 ◽  
Author(s):  
Susanne Paukner ◽  
Robert K Flamm ◽  
Steven P Gelone ◽  
Helio S Sader

Abstract Background LEF, the first pleuromutilin antibiotic for IV and oral use in humans, is in Phase 3 clinical trials for the treatment of CABP in adults. In the first of these to be completed, LEF demonstrated noninferiority to moxifloxacin ± linezolid. LEF inhibits bacterial translation by binding the 50S ribosomal subunit at the A- and P-sites in the peptidyl transferase center. CABP is a leading cause of infectious diseases in the United States and increasing antibacterial resistance complicates its treatment. This study investigated the in vitro activity of LEF and comparators against a contemporary set of bacterial respiratory pathogens collected in the United States. Methods Isolates (n = 1674, 1/patient) were collected from 32 medical centers in the United States as part of the SENTRY Surveillance Program. LEF and comparators were tested by CLSI broth microdilution methods, and susceptibility was determined using the CLSI (2018) breakpoints. Results LEF was the most active compound against Streptococcus pneumoniae (MIC50/90 of 0.12/0.12 µg/mL), and its activity was not affected by resistance to other antibiotic classes. S. pneumoniae isolates were susceptible to levofloxacin (99.1%) and ceftriaxone (97.7%), whereas only 53.9%, 63.9%, and 80.4% of isolates were susceptible to macrolides, penicillin (oral), and tetracycline, respectively. LEF also showed potent activity against Staphylococcus aureus (MIC50/90 of 0.06/0.12 µg/mL), including methicillin-resistant (MRSA) isolates (MIC50/90 of 0.06/0.12 µg/mL, 87.1% resistant to erythromycin), Haemophilus influenzae, (MIC50/90 of 0.5/1 µg/mL, 26.9% β-lactamase producing), and Moraxella catarrhalis (MIC50/90 0.06/0.06 µg/mL, 96.5% β-lactamase positive) (figure). Conclusion LEF displayed potent in vitro activity against a contemporary collection of respiratory pathogens from the United States. LEF was active regardless of resistance phenotype to other antibiotic classes including β-lactams, tetracyclines, or macrolides. These results further support the clinical development of lefamulin for the treatment of CABP or other respiratory tract infections. Disclosures S. Paukner, Nabriva: Employee and Shareholder, Salary. R. K. Flamm, Nabriva: Research Contractor, Research grant. S. P. Gelone, Nabriva Therapeutics: Employee, Equity, Shareholder and Salary. Achaogen: Shareholder, Equity, Shareholder. H. S. Sader, Nabriva Therapeutics: Research Contractor, Research support.


2009 ◽  
Vol 53 (5) ◽  
pp. 2171-2175 ◽  
Author(s):  
Helio S. Sader ◽  
Thomas R. Fritsche ◽  
Ronald N. Jones

ABSTRACT The in vitro activity of iclaprim, a novel diaminopyrimidine derivative, was evaluated against 5,937 recent gram-positive clinical isolates collected in the United States and Europe. Iclaprim demonstrated potent activity against Staphylococcus aureus (including methicillin-resistant S. aureus [MRSA]), beta-hemolytic Streptococcus spp., and Enterococcus faecalis strains tested. In addition, iclaprim exhibited bactericidal activity against all S. aureus strains tested, including MRSA.


2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S369-S369 ◽  
Author(s):  
Michael A Pfaller ◽  
Helio S Sader ◽  
Dee Shortridge ◽  
Robert K Flamm ◽  
Rodrigo E Mendes

Abstract Background Oritavancin (ORI) has documented in vitro activity against gram-positive (GP) isolates. This study analyzed ORI tested against organisms causing endocarditis in United States (US) and European (EU) sites. Methods A total of 424 organisms recovered from patients with a diagnosis of bacterial endocarditis at US and EU sites during the SENTRY Antimicrobial Surveillance Program (2008–2016) were included (see Table). Isolates were identified by standard biochemical algorithms and MALDI-TOF. Susceptibility (S) testing was performed by CLSI methods, and MICs were interpreted per CLSI and/or EUCAST criteria. Results Among the 424 isolates, 212 (50.0%) were S. aureus (SA; 31.6% methicillin-resistant [MRSA]), 47 (11.1%) were coagulase-negative staphylococci (CoNS), 81 (19.1%) were E. faecalis (EFC), 21 (5.0%) were E. faecium (EFM), 24 (5.7%) were BHS, and 39 (9.2%) were viridans group streptococci (VGS). ORI had similar MIC90 values (0.06 µg/mL) against SA and CoNS, inhibiting 98.8% of these isolates at ≤0.12 µg/mL. ORI MIC50 values were 8- to 32-fold lower than those for vancomycin (VAN), daptomycin (DAP), and ceftaroline (CPT) against staphylococci. ORI showed MICs against EFM (MIC50/90, 0.008/0.03 µg/mL) that were 2-fold lower than against EFC (MIC50/90, 0.015/0.03 µg/mL; 97.5%S against all or 100%S against indicated VAN-S isolates). ORI inhibited 98.0% of all enterococci, including VAN-resistant isolates at ≤0.12 µg/mL. VAN, DAP, ampicillin (MIC50/90, ≤1/2 µg/mL), and linezolid (LZD) (MIC50/90, 1/2 µg/mL) were similarly active against EFC, while DAP and LZD had coverage (100.0%S) against EFM. Overall, BHS were highly S to all agents tested, except for erythromycin (70.8%S) and tetracycline (43.5%S). ORI was the most active agent (MIC90, 0.12 µg/mL) tested against VGS. Conclusion ORI showed potent in vitro activity against isolates recovered from patients with endocarditis in US and EU sites. The data presented here warrant further investigations to determine whether ORI has a role for treating endocarditis. Disclosures M. A. Pfaller, The Medicines Company: Research Contractor, Research grant; H. S. Sader, The Medicines Company: Research Contractor, Research grant; D. Shortridge, The Medicines Company: Research Contractor, Research grant; R. K. Flamm, The Medicines Company: Research Contractor, Research grant; R. E. Mendes, The Medicines Company: Research Contractor, Research grant


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