scholarly journals Enzymatically-crosslinked gelatin hydrogels containing paenipeptin and clarithromycin against carbapenem-resistant pathogen in murine skin wound infection

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sun Hee Moon ◽  
Yihong Kaufmann ◽  
Ryoichi Fujiwara ◽  
En Huang
Keyword(s):  
Wound Infection ◽  
Multidrug Resistant ◽  
Skin Wound ◽  
Drug Resistant ◽  
Wound Infections ◽  
Log Reduction ◽  
Carbapenem Resistant ◽  
Infected Wounds ◽  
Localized Delivery

Abstract Background The recent rise and spread of carbapenem-resistant pathogens pose an urgent threat to public health and has fueled the search for new therapies. Localized delivery of topical antibiotics is an alternative for the treatment of infected wounds caused by drug-resistant pathogens. In this study, we aimed to develop antimicrobial-loaded hydrogels for topical treatment of wound infections in a murine skin wound infection. Results Paenipeptin analogue 1, a linear lipopeptide, potentiated clarithromycin against multidrug-resistant Acinetobacter baumannii, Enterobacter cloacae, Escherichia coli, and Klebsiella pneumoniae. Enzymatically-crosslinked gelatin hydrogels were developed to encapsulate paenipeptin analogue 1 and clarithromycin. The encapsulated antimicrobials were gradually released from hydrogels during incubation, reaching 75.43 and 53.66% for paenipeptin and clarithromycin, respectively, at 24 h. The antimicrobial-loaded hydrogels containing paenipeptin and clarithromycin synergistically resulted in 5-log reduction in carbapenem-resistant A. baumannii within 6 h in vitro. Moreover, the antimicrobial-loaded hydrogels reduced 3.6- and 2.5-log of carbapenem-resistant A. baumannii when treated at 4 or 20 h post infection, respectively, in a murine skin wound infection. Conclusions Enzymatically-crosslinked gelatin hydrogels loaded with paenipeptin analogue 1 and clarithromycin exhibited potent therapeutic efficacy against carbapenem-resistant A. baumannii in murine skin wound infection.

scholarly journals New β-Lactam–β-Lactamase Inhibitor Combinations

2020 ◽  
Vol 34 (1) ◽  
Author(s):  
Dafna Yahav ◽  
Christian G. Giske ◽  
Alise Grāmatniece ◽  
Henrietta Abodakpi ◽  
Vincent H. Tam ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Treatment Option ◽  
Clinical Data ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Class D ◽  
Lactamase Inhibitor

SUMMARY The limited armamentarium against drug-resistant Gram-negative bacilli has led to the development of several novel β-lactam–β-lactamase inhibitor combinations (BLBLIs). In this review, we summarize their spectrum of in vitro activities, mechanisms of resistance, and pharmacokinetic-pharmacodynamic (PK-PD) characteristics. A summary of available clinical data is provided per drug. Four approved BLBLIs are discussed in detail. All are options for treating multidrug-resistant (MDR) Enterobacterales and Pseudomonas aeruginosa. Ceftazidime-avibactam is a potential drug for treating Enterobacterales producing extended-spectrum β-lactamase (ESBL), Klebsiella pneumoniae carbapenemase (KPC), AmpC, and some class D β-lactamases (OXA-48) in addition to carbapenem-resistant Pseudomonas aeruginosa. Ceftolozane-tazobactam is a treatment option mainly for carbapenem-resistant P. aeruginosa (non-carbapenemase producing), with some activity against ESBL-producing Enterobacterales. Meropenem-vaborbactam has emerged as treatment option for Enterobacterales producing ESBL, KPC, or AmpC, with similar activity as meropenem against P. aeruginosa. Imipenem-relebactam has documented activity against Enterobacterales producing ESBL, KPC, and AmpC, with the combination having some additional activity against P. aeruginosa relative to imipenem. None of these drugs present in vitro activity against Enterobacterales or P. aeruginosa producing metallo-β-lactamase (MBL) or against carbapenemase-producing Acinetobacter baumannii. Clinical data regarding the use of these drugs to treat MDR bacteria are limited and rely mostly on nonrandomized studies. An overview on eight BLBLIs in development is also provided. These drugs provide various levels of in vitro coverage of carbapenem-resistant Enterobacterales, with several drugs presenting in vitro activity against MBLs (cefepime-zidebactam, aztreonam-avibactam, meropenem-nacubactam, and cefepime-taniborbactam). Among these drugs, some also present in vitro activity against carbapenem-resistant P. aeruginosa (cefepime-zidebactam and cefepime-taniborbactam) and A. baumannii (cefepime-zidebactam and sulbactam-durlobactam).

scholarly journals Antimicrobial Activity of Aztreonam-Avibactam and Comparator Agents Tested against Contemporary (2016) Clinical Enterobacteriaceae Isolates

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S376-S377
Author(s):  
Helio S Sader ◽  
Rodrigo E Mendes ◽  
Dee Shortridge ◽  
Robert K Flamm ◽  
Mariana Castanheira
Keyword(s):  
Multidrug Resistant ◽  
Coli Strain ◽  
Sequencing Analysis ◽  
Drug Resistant ◽  
Medical Centers ◽  
Carbapenem Resistant ◽  
Class D ◽  
Encoding Genes ◽  
Research Grant

Abstract Background Avibactam (AVI) is a non-β-lactam β-lactamase (BL) inhibitor that inhibits Ambler class A, C, and some class D enzymes (eg, ESBL, KPC, and AmpC), and aztreonam (ATM) is a monobactam stable to hydrolysis by metallo-β-lactamases (MBL). Methods A total of 10,451 Enterobacteriaceae(ENT) consecutively collected from 84 United States (US) medical centers and 250 carbapenem-resistant ENT (CRE) collected from 38 centers in 25 other countries (ex-US) were tested for susceptibility (S) by reference broth microdilution methods in a central monitoring laboratory (JMI Laboratories). CRE strains were screened for the presence of carbapenemase (CBP)-encoding genes using whole genome sequencing analysis. Results All ENT isolates from US (MIC50/90, ≤0.03/0.12 μg/mL), except for 1 Escherichia coli strain with an ATM-AVI MIC of 8 μg/mL, and all ex-US CRE isolates (MIC50/90, 0.25/0.5 μg/mL) were inhibited at ATM-AVI MIC of ≤4 µg/mL (CLSI S breakpoint for ATM). Among US isolates, ATM-AVI was also very active against CRE (n = 120; MIC50/90, 0.12/0.5 μg/mL; highest MIC, 4 μg/mL), multidrug-resistant (MDR; n = 876; MIC50/90, 0.06/0.25 μg/mL), extensively drug-resistant (XDR; n = 111; MIC50/90, 0.12/0.5 μg/mL), pan-drug resistant (n = 2; MICs ≤0.03 and 0.12 μg/mL), and ceftazidime-non-S Enterobacter cloacae (MIC50/90, 0.25/1 μg/mL) isolates. Meropenem was very active against US ENT overall (MIC50/90, 0.03/0.06 μg/mL; 98.8%S per CLSI), but showed limited activity against MDR (86.2%S) and XDR (30.6%S) isolates. Amikacin and colistin were active against 74.2% and 81.7% of US CRE, 93.4% and 58.3% US MDR, 65.8% and 57.7% of US XDR, and 58.0% and 79.2% of ex-US CRE isolates, respectively. A total of 106 CBPs were detected in 106 US CRE isolates, including 102 KPC-like, 2 SME-4, 1 NDM-1, and 1 IMP-27. Also, 248 CBPs were identified on 241 ex-US CRE isolates, including 124 KPC-like, 64 OXA-like, 50 NDM-like, 7 VIM-1, 2 IMP-4, and 1 SME-4. All CRE isolates, including all CBP-producing ENT (US and ex-US), were inhibited at ATM-AVI MIC of ≤4 μg/mL. Conclusion ATM-AVI demonstrated potent in vitro activity against a large collection of contemporary (2016) ENT isolated from patients in US hospitals and CRE isolates collected worldwide, including NDM, KPC, OXA, VIM, and SME producers. Disclosures H. S. Sader, Allergan: Research Contractor, Research grant; R. E. Mendes, Allergan: Research Contractor, Research grant; D. Shortridge, Allergan: Research Contractor, Research grant; R. K. Flamm, Allergan: Research Contractor, Research grant; M. Castanheira, Allergan: Research Contractor, Research grant

scholarly journals Antibiotic Susceptibility of NDM-Producing Enterobacterales Collected in the United States in 2017 and 2018

2020 ◽  
Vol 64 (9) ◽  
Author(s):  
Joseph D. Lutgring ◽  
Rocío Balbuena ◽  
Natashia Reese ◽  
Sarah E. Gilbert ◽  
Uzma Ansari ◽  
...  
Keyword(s):  
United States ◽  
Antibiotic Susceptibility ◽  
Treatment Options ◽  
The United States ◽  
Multidrug Resistant ◽  
New Delhi ◽  
Drug Resistant ◽  
Carbapenem Resistant ◽  
Extensively Drug Resistant

ABSTRACT The treatment of infections caused by carbapenem-resistant Enterobacterales, especially New Delhi metallo-β-lactamase (NDM)-producing bacteria, is challenging. Although less common in the United States than some other carbapenemase producers, NDM-producing bacteria are a public health threat due to the limited treatment options available. Here, we report on the antibiotic susceptibility of 275 contemporary NDM-producing Enterobacterales collected from 30 U.S. states through the Centers for Disease Control and Prevention’s Antibiotic Resistance Laboratory Network. The aims of the study were to determine the susceptibility of these isolates to 32 currently available antibiotics using reference broth microdilution and to explore the in vitro activity of 3 combination agents that are not yet available. Categorical interpretations were determined using Clinical and Laboratory Standards Institute (CLSI) interpretive criteria. For agents without CLSI criteria, Food and Drug Administration (FDA) interpretive criteria were used. The percentage of susceptible isolates did not exceed 90% for any of the FDA-approved antibiotics tested. The antibiotics with breakpoints that had the highest in vitro activity were tigecycline (86.5% susceptible), eravacycline (66.2% susceptible), and omadacycline (59.6% susceptible); 18.2% of isolates were susceptible to aztreonam. All NDM-producing isolates tested were multidrug resistant, and 116 isolates were extensively drug resistant (42.2%); 207 (75.3%) isolates displayed difficult-to-treat resistance. The difficulty in treating infections caused by NDM-producing Enterobacterales highlights the need for containment and prevention efforts to keep these infections from becoming more common.

scholarly journals 1542. The Evaluation of the In Vitro Synergy of Colistin in Combination with Meropenem and Tigecycline against 50 Multi-Drug-resistant Acinetobacter baumannii strains

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S562-S563
Author(s):  
Jacinda Abdul-Mutakabbir ◽  
Juwom Yim ◽  
Logan Nguyen ◽  
Razieh Kebriaei ◽  
Kyle Stamper ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Bactericidal Activity ◽  
Single Agent ◽  
Resistance Mechanisms ◽  
Drug Resistant ◽  
Initial Inoculum ◽  
Log Reduction ◽  
Carbapenem Resistant ◽  
Time Kill

Abstract Background Acinetobacter baumannii possess inherent and acquired antibiotic resistance mechanisms that have rendered most antibiotics, including carbapenems, inactive. Colistin (COL) has risen as salvage therapy against these organisms due to its retained activity against A. baumannii. However, COL monotherapy is often met with suboptimal outcomes. Recently, combination therapy with COL and meropenem (MEM) or tigecycline (TGC) has been shown to be effective in eradicating multi-drug-resistant A. baumannii infections. The objective of this study was to further evaluate the efficacy of COL in combination with MEM or TGC against 50 multi-drug-resistant A. baumannii strains. Methods Fifty carbapenem-resistant A. baumannii strains were evaluated using combination minimum inhibitory concentration (MIC) testing and time-kill analysis (TKA). Single-drug MIC testing was performed for each strain by broth microdilution. Combination MIC testing was performed for COL+MEM and COL+TGC. Each strain was evaluated via 24-hour TKA to assess the synergistic capabilities of COL+MEM, and COL+TGC. Synergy was defined as a ≥ 2-log reduction CFU/mL in either combination from the most active single agent, while bactericidal activity was defined as a ≥ 3-log reduction CFU/mL of either combination from the initial inoculum. Results All 50 strains were resistant to MEM and TGC with MICs ≥ 64 µg/mL and ≥ 4 µg/mL respectively; while 3 strains were resistant to COL, MICs ≥ 2 µg/mL. MEM and TGC MIC values were reduced as much as 128-fold (median 2-fold) and 32-fold (median 2-fold),, respectively, in the presence of subinhibitory COL. COL MIC values were reduced as much as 512-fold (median 4-fold) from baseline in the presence of subinhibitory MEM, and as high as 16-fold (median 2-fold) in the presence of TGC. In TKAs, COL+MEM was synergistic in 45/50 (90%) strains and bactericidal against 43/50 (86%) strains. COL+TGC TKAs revealed synergy in 32/50 (64%) strains, and bactericidal activity against 28/50 (56%) strains. Conclusion The combinations of COL+MEM and COL+TGC demonstrate promise in combating highly resistant A. baumannii. Further research is mandated to explore other combinations that are capable of eradicating multi-drug-resistant A. baumannii. Disclosures All authors: No reported disclosures.

scholarly journals Antimicrobial Activity of Ceftazidime-Avibactam Tested against Multidrug-Resistant Enterobacteriaceae and Pseudomonas aeruginosa Isolates from United States (US) Medical Centers (2013–2016)

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S376-S376
Author(s):  
Helio S Sader ◽  
Mariana Castanheira ◽  
Dee Shortridge ◽  
Rodrigo E Mendes ◽  
Robert K Flamm
Keyword(s):  
Multidrug Resistant ◽  
Drug Resistant ◽  
In Vitro Activity ◽  
Negative Results ◽  
Medical Centers ◽  
Carbapenem Resistant ◽  
Extensively Drug Resistant ◽  
Genes Encoding ◽  
Research Grant

Abstract Background The in vitro activity of ceftazidime-avibactam (CAZ-AVI) and many comparator agents were tested against various resistant subsets of organisms selected among 36,380 Enterobacteriaceae and 7,868 P. aeruginosa isolates. Methods Isolates were consecutively collected from 94 US hospitals in 2013–2016 and tested for susceptibility by reference broth microdilution methods in a central monitoring laboratory (JMI Laboratories) as part of the International Network for Optimal Resistance Monitoring (INFORM) program. Enterobacteriaceae strains with elevated CAZ-AVI MIC values (≥16 μg/mL) were evaluated for the presence of genes encoding extended-spectrum β-lactamases, KPC, NDM, and transferable AmpC enzymes. Results CAZ-AVI inhibited >99.9% of all Enterobacteriaceae at the susceptible (S) breakpoint of ≤8 μg/mL and was active against multidrug-resistant (MDR; n = 2,953; MIC50/90, 0.25/1 μg/mL; 99.2%S, extensively drug-resistant (XDR; n = 448; MIC50/90, 0.5/2 μg/mL; 97.8%S), and carbapenem-resistant isolates (CRE; n = 513; MIC50/90, 0.5/2 μg/mL; 97.5%S). Only 82.2% of MDR Enterobacteriaceae and 64.2% of ceftriaxone-nonsusceptible (NS) Klebsiella pneumoniae (n = 1,063) were meropenem-S. Among Enterobacter cloacae (n = 3,740; 22.2% ceftazidime-NS), 99.8% of isolates, including 99.3% of ceftazidime-NS isolates, were CAZ-AVI-S. Only 22 of 36,380 Enterobacteriaceae (0.06%) isolates were CAZ-AVI-NS, including 8 MBL-producers (0.02%) and 2 KPC-producing strains with porin alteration; the remaining 12 strains showed negative results for all β-lactamases tested. CAZ-AVI showed potent activity against P. aeruginosa (n = 7,868; MIC50/90, 2/4 μg/mL; 97.1% S), including meropenem-NS (n = 1,471; MIC50/90, 4/16 μg/mL; 87.2%S) and MDR (n = 1,562; MIC50/90, 4/16 μg/mL; 86.5%S) isolates, and inhibited 71.8% of isolates NS to meropenem, piperacillin-tazobactam, and ceftazidime (n = 628). Conclusion CAZ-AVI demonstrated potent activity against a large US collection (n = 44,248) of contemporary gram-negative bacilli, including organisms resistant to most currently available agents, such as CRE and meropenem-NS P. aeruginosa. Disclosures H. S. Sader, Allergan: Research Contractor, Research grant; M. Castanheira, Allergan: Research Contractor, Research grant; D. Shortridge, Allergan: Research Contractor, Research grant; R. E. Mendes, Allergan: Research Contractor, Research grant; R. K. Flamm, Allergan: Research Contractor, Research grant

scholarly journals Comparison of In Vitro Activity and MIC Distributions between the Novel Oxazolidinone Delpazolid and Linezolid against Multidrug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosis in China

2018 ◽  
Vol 62 (8) ◽  
Author(s):  
Zhaojing Zong ◽  
Wei Jing ◽  
Jin Shi ◽  
Shu'an Wen ◽  
Tingting Zhang ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Novel Mutation ◽  
Multidrug Resistant ◽  
23S Rrna ◽  
Drug Resistant ◽  
Content Type ◽  
Extensively Drug Resistant ◽  
Significant Difference ◽  
Mdr Tb

ABSTRACT Oxazolidinones are efficacious in treating mycobacterial infections, including tuberculosis (TB) caused by drug-resistant Mycobacterium tuberculosis. In this study, we compared the in vitro activities and MIC distributions of delpazolid, a novel oxazolidinone, and linezolid against multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) in China. Additionally, genetic mutations in 23S rRNA, rplC, and rplD genes were analyzed to reveal potential mechanisms underlying the observed oxazolidinone resistance. A total of 240 M. tuberculosis isolates were included in this study, including 120 MDR-TB isolates and 120 XDR-TB isolates. Overall, linezolid and delpazolid MIC90 values for M. tuberculosis isolates were 0.25 mg/liter and 0.5 mg/liter, respectively. Based on visual inspection, we tentatively set epidemiological cutoff (ECOFF) values for MIC determinations for linezolid and delpazolid at 1.0 mg/liter and 2.0 mg/liter, respectively. Although no significant difference in resistance rates was observed between linezolid and delpazolid among XDR-TB isolates (P > 0.05), statistical analysis revealed a significantly greater proportion of linezolid-resistant isolates than delpazolid-resistant isolates within the MDR-TB group (P = 0.036). Seven (53.85%) of 13 linezolid-resistant isolates were found to harbor mutations within the three target genes. Additionally, 1 isolate exhibited an amino acid substitution (Arg126His) within the protein encoded by rplD that contributed to high-level resistance to linezolid (MIC of >16 mg/liter), compared to a delpazolid MIC of 0.25. In conclusion, in vitro susceptibility testing revealed that delpazolid antibacterial activity was comparable to that of linezolid. A novel mutation within rplD that endowed M. tuberculosis with linezolid, but not delpazolid, resistance was identified.

A renewed look at silver dressings for wound infections: Ag Oxysalts technology

2021 ◽  
Vol 26 (Sup9) ◽  
pp. S26-S36
Author(s):  
Luxmi Dhoonmoon ◽  
Hayley Turner-Dobbin ◽  
Karen Staines
Keyword(s):  
Wound Healing ◽  
Wound Infection ◽  
Case Studies ◽  
Healing Process ◽  
Systemic Toxicity ◽  
Wound Healing Process ◽  
Wound Infections ◽  
Infected Wounds ◽  
Long Time

Wound infection is an important complicating factor in the wound healing process, and infections can be even more complex and difficult to manage in the case of wounds with biofilms. Silver has been used to treat infected wounds for a long time now, and the strength of the product depends on the number of Ag ions, where the greater the number of ions, the higher and faster the reactivity is. Ag Oxysalts technology—used in 3M Kerracontact Ag dressing—has three times more ions than standard silver dressings. The technology also does not show the typical disadvantages of silver, such as cytotoxicity and systemic toxicity. This article discusses the use of Ag Oxysalts technology for infected wounds and presents case studies to support the efficacy of this product in promoting wound healing.

scholarly journals In Vitro Activity of the Novel Pleuromutilin Lefamulin (BC-3781) and Effect of Efflux Pump Inactivation on Multidrug-Resistant and Extensively Drug-Resistant Neisseria gonorrhoeae

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Susanne Jacobsson ◽  
Susanne Paukner ◽  
Daniel Golparian ◽  
Jörgen S. Jensen ◽  
Magnus Unemo
Keyword(s):  
Efflux Pump ◽  
Multidrug Resistant ◽  
Cross Resistance ◽  
Drug Resistant ◽  
The Novel ◽  
Extensively Drug Resistant ◽  
Optimal Dosing ◽  
And Performance ◽  
Reference Strains

ABSTRACT We evaluated the activity of the novel semisynthetic pleuromutilin lefamulin, inhibiting protein synthesis and growth, and the effect of efflux pump inactivation on clinical gonococcal isolates and reference strains (n = 251), including numerous multidrug-resistant and extensively drug-resistant isolates. Lefamulin showed potent activity against all gonococcal isolates, and no significant cross-resistance to other antimicrobials was identified. Further studies of lefamulin are warranted, including in vitro selection and mechanisms of resistance, pharmacokinetics/pharmacodynamics, optimal dosing, and performance in randomized controlled trials.

scholarly journals In Vitro Properties of BAL30072, a Novel Siderophore Sulfactam with Activity against Multiresistant Gram-Negative Bacilli

2010 ◽  
Vol 54 (6) ◽  
pp. 2291-2302 ◽  
Author(s):  
Malcolm G. P. Page ◽  
Clothilde Dantier ◽  
Eric Desarbre
Keyword(s):  
Multidrug Resistant ◽  
Unusual Property ◽  
Gram Negative ◽  
Penicillin Binding Proteins ◽  
High Affinity ◽  
Class A ◽  
Carbapenem Resistant ◽  
Lactam Antibiotic ◽  
Resistant Strains

ABSTRACT BAL30072 is a new monocyclic β-lactam antibiotic belonging to the sulfactams. Its spectrum of activity against significant Gram-negative pathogens with β-lactam-resistant phenotypes was evaluated and was compared with the activities of reference drugs, including aztreonam, ceftazidime, cefepime, meropenem, imipenem, and piperacillin-tazobactam. BAL30072 showed potent activity against multidrug-resistant (MDR) Pseudomonas aeruginosa and Acinetobacter sp. isolates, including many carbapenem-resistant strains. The MIC90s were 4 μg/ml for MDR Acinetobacter spp. and 8 μg/ml for MDR P. aeruginosa, whereas the MIC90 of meropenem for the same sets of isolates was >32 μg/ml. BAL30072 was bactericidal against both Acinetobacter spp. and P. aeruginosa, even against strains that produced metallo-β-lactamases that conferred resistance to all other β-lactams tested, including aztreonam. It was also active against many species of MDR isolates of the Enterobacteriaceae family, including isolates that had a class A carbapenemase or a metallo-β-lactamase. Unlike other monocyclic β-lactams, BAL30072 was found to trigger the spheroplasting and lysis of Escherichia coli rather than the formation of extensive filaments. The basis for this unusual property is its inhibition of the bifunctional penicillin-binding proteins PBP 1a and PBP 1b, in addition to its high affinity for PBP 3, which is the target of monobactams, such as aztreonam.

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