scholarly journals In VitroActivity of LYS228, a Novel Monobactam Antibiotic, against Multidrug-ResistantEnterobacteriaceae

2018 ◽  
Vol 62 (10) ◽  
Author(s):  
Johanne Blais ◽  
Sara Lopez ◽  
Cindy Li ◽  
Alexey Ruzin ◽  
Srijan Ranjitkar ◽  
...  

ABSTRACTLYS228 is a novel monobactam with potent activity againstEnterobacteriaceae. LYS228 is stable to metallo-β-lactamases (MBLs) and serine carbapenemases, includingKlebsiella pneumoniaecarbapenemases (KPCs), resulting in potency against the majority of extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistantEnterobacteriaceaestrains tested. Overall, LYS228 demonstrated potent activity against 271Enterobacteriaceaestrains, including multidrug-resistant isolates. Based on MIC90values, LYS228 (MIC90, 1 μg/ml) was ≥32-fold more active against those strains than were aztreonam, ceftazidime, ceftazidime-avibactam, cefepime, and meropenem. The tigecycline MIC90was 4 μg/ml against the strains tested. AgainstEnterobacteriaceaeisolates expressing ESBLs (n= 37) or displaying carbapenem resistance (n= 77), LYS228 had MIC90values of 1 and 4 μg/ml, respectively. LYS228 exhibited potent bactericidal activity, as indicated by low minimal bactericidal concentration (MBC) to MIC ratios (MBC/MIC ratios of ≤4) against 97.4% of theEnterobacteriaceaestrains tested (264/271 strains). In time-kill studies, LYS228 consistently achieved reductions in CFU per milliliter of 3 log10units (≥99.9% killing) at concentrations ≥4× MIC forEscherichia coliandK. pneumoniaereference strains, as well as isolates encoding TEM-1, SHV-1, CTX-M-14, CTX-M-15, KPC-2, KPC-3, and NDM-1 β-lactamases.

2018 ◽  
Vol 62 (8) ◽  
Author(s):  
M. Thwaites ◽  
D. Hall ◽  
D. Shinabarger ◽  
A. W. Serio ◽  
K. M. Krause ◽  
...  

ABSTRACT The next-generation aminoglycoside plazomicin, in development for infections due to multidrug-resistant (MDR) Enterobacteriaceae, was evaluated alongside comparators for bactericidal activity in minimum bactericidal concentration (MBC) and time-kill (TK) assays against MDR Enterobacteriaceae isolates with characterized aminoglycoside and β-lactam resistance mechanisms. Overall, plazomicin and colistin were the most potent, with plazomicin demonstrating an MBC50/90 of 0.5/4 μg/ml and sustained 3-log10 kill against MDR Escherichia coli, Klebsiella pneumoniae, and Enterobacter spp.


2019 ◽  
Vol 63 (8) ◽  
Author(s):  
Sandra Mikhail ◽  
Nivedita B. Singh ◽  
Razieh Kebriaei ◽  
Seth A. Rice ◽  
Kyle C. Stamper ◽  
...  

ABSTRACT Multidrug-resistant (MDR) Gram-negative organisms are a major health concern due to lack of effective therapy. Emergence of resistance to newer agents like ceftazidime-avibactam (CZA) further magnifies the problem. In this context, combination therapy of CZA with other antimicrobials may have potential in treating these pathogens. Unfortunately, there are limited data regarding these combinations. Therefore, the objective of this study was to evaluate CZA in combination with amikacin (AMK), aztreonam (AZT), colistin (COL), fosfomycin (FOS), and meropenem (MEM) against 21 carbapenem-resistant Klebsiella pneumoniae and 21 MDR Pseudomonas aeruginosa strains. The potential for synergy was evaluated via MIC combination evaluation and time-kill assays. All strains were further characterized by whole-genome sequencing, quantitative real-time PCR, and SDS-PAGE analysis to determine potential mechanisms of resistance. Compared to CZA alone, we observed a 4-fold decrease in CZA MICs for a majority of K. pneumoniae strains and at least a 2-fold decrease for most P. aeruginosa isolates in the majority of combinations tested. In both P. aeruginosa and K. pneumoniae strains, CZA in combination with AMK or AZT was synergistic (≥2.15-log10 CFU/ml decrease). CZA-MEM was effective against P. aeruginosa and CZA-FOS was effective against K. pneumoniae. Time-kill analysis also revealed that the synergy of CZA with MEM or AZT may be due to the previously reported restoration of MEM or AZT activity against these organisms. Our findings show that CZA in combination with these antibiotics has potential for therapeutic options in difficult to treat pathogens. Further evaluation of these combinations is warranted.


2016 ◽  
Vol 60 (8) ◽  
pp. 4770-4777 ◽  
Author(s):  
Mariana Castanheira ◽  
Rodrigo E. Mendes ◽  
Ronald N. Jones ◽  
Helio S. Sader

ABSTRACTAmong 15,588Enterobacteriaceaeisolates collected in 63 U.S. hospitals from 2012 to 2014, 2,129 (13.7%) displayed an extended-spectrum β-lactamase (ESBL) phenotype. These rates were similar over time (13.2 to 13.9%); however, differences amongEscherichia coli(12.7 and 15.1% in 2012 and 2014;P= 0.007) andKlebsiella pneumoniae(18.9 and 15.5% in 2012 and 2014;P= 0.006) were noted when comparing 2014 and 2012. Carbapenem-resistantEnterobacteriaceae(CRE) (2.3 and 1.8%) and carbapenem-resistantK. pneumoniae(6.8 and 5.1%;P= 0.003) rates were lower in 2014 than in 2012. Isolates carryingblaCTX-M-15-like genes were stable (42.1 to 42.4%), but a decrease amongE. coliisolates (59.1 and 49.7%;P= 0.008) and an increase amongK. pneumoniaeisolates (32.7 and 41.2%;P= 0.022) in 2014 were observed. Isolates carryingblaKPC(304) decreased over the years (16.5 and 10.9%;P= 0.008), mainly due to the decrease inK. pneumoniaeisolates harboringblaKPC(n= 285; 35.6 and 28.4%;P= 0.041) in hospitals in the Mid-Atlantic and South Atlantic regions, where these isolates were highly prevalent during 2012 and 2013. Isolates carryingblaCMY-2-like andblaCTX-M-14-like genes increased (8.2 and 11.9% and 9.1 and 12.9%, respectively;P= 0.04 for both), and those producingblaSHVESBL decreased (24.9 and 12.7%;P< 0.001) over the studied years, due to a decreased occurrence of the enzymes amongK. pneumoniaeisolates. Other enzymes were detected in smaller numbers of isolates, including fourK. pneumoniaeisolates carryingblaNDM-1metallo-β-lactamase (two in 2012 and two in 2014). Ceftazidime-avibactam, a recently approved β-lactamase inhibitor combination, was very active against the ESBL phenotype isolates (MIC50/90, 0.12 and 1 μg/ml; 99.7% susceptible) and CRE strains (MIC50/90, 0.5 and 2 μg/ml; 98.5% susceptible) that displayed elevated MIC values for many comparator agents. In conclusion, significant changes were noted in the frequencies of isolates harboring various β-lactamases among U.S. hospitals between 2012 and 2014 that will require continued monitoring.


2010 ◽  
Vol 54 (6) ◽  
pp. 2732-2734 ◽  
Author(s):  
Carl Urban ◽  
Noriel Mariano ◽  
James J. Rahal

ABSTRACT In vitro double and triple bactericidal activities of doripenem, polymyxin B, and rifampin were assessed against 20 carbapenem-resistant clinical isolates with different mechanisms of carbapenem resistance. Bactericidal activity was achieved in 90% of all bacteria assayed using combinations of polymyxin B, doripenem, and rifampin against five each of the carbapenem-resistant Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli isolates studied. Combinations with these antibacterials may provide a strategy for treatment of patients infected with such organisms.


2013 ◽  
Vol 58 (2) ◽  
pp. 1214-1217 ◽  
Author(s):  
Ying Zhang ◽  
Xiaofei Jiang ◽  
Yanyan Wang ◽  
Gang Li ◽  
Yueru Tian ◽  
...  

ABSTRACTFifty-seven carbapenem-resistantKlebsiella pneumoniaeisolates belonging to ST11 (50 isolates), ST423 (5 isolates), and two other sequence types were studied. All were positive forblaKPC-2,blaTEM-1, andblaCTX-M-14. SDS-PAGE analysis of six representative isolates demonstrated varied porin expression. Nevertheless, whenblaKPC-2was deleted, carbapenem resistance was markedly reduced. Additionally, SHV-12, DHA-1, and/or VIM-1 appeared to contribute to accessory carbapenemase activity. In contrast, OmpK35 and/or OmpK36 deficiency seemed to serve only as a minor cooperative factor.


2020 ◽  
Vol 6 (12) ◽  
Author(s):  
Katlego Kopotsa ◽  
Nontombi M. Mbelle ◽  
John Osei Sekyere

Carbapenem-resistant Klebsiella pneumoniae (CRKP) remains a major clinical pathogen and public health threat with few therapeutic options. The mobilome, resistome, methylome, virulome and phylogeography of CRKP in South Africa and globally were characterized. CRKP collected in 2018 were subjected to antimicrobial susceptibility testing, screening by multiplex PCR, genotyping by repetitive element palindromic (REP)-PCR, plasmid size, number, incompatibility and mobility analyses, and PacBio’s SMRT sequencing (n=6). There were 56 multidrug-resistant CRKP, having bla OXA-48-like and bla NDM-1/7 carbapenemases on self-transmissible IncF, A/C, IncL/M and IncX3 plasmids endowed with prophages, traT, resistance islands, and type I and II restriction modification systems (RMS). Plasmids and clades detected in this study were respectively related to globally established/disseminated plasmids clades/clones, evincing transboundary horizontal and vertical dissemination. Reduced susceptibility to colistin occurred in 23 strains. Common clones included ST307, ST607, ST17, ST39 and ST3559. IncFIIk virulent plasmid replicon was present in 56 strains. Whole-genome sequencing of six strains revealed least 41 virulence genes, extensive ompK36 mutations, and four different K- and O-loci types: KL2, KL25, KL27, KL102, O1, O2, O4 and O5. Types I, II and III RMS, conferring m6A (G A TC, G A TGNNNNNNTTG, CA A NNNNNNCATC motifs) and m4C (C C WGG) modifications on chromosomes and plasmids, were found. The nature of plasmid-mediated, clonal and multi-clonal dissemination of blaOXA-48-like and blaNDM-1 mirrors epidemiological trends observed for closely related plasmids and sequence types internationally. Worryingly, the presence of both bla OXA-48 and bla NDM-1 in the same isolates was observed. Plasmid-mediated transmission of RMS, virulome and prophages influence bacterial evolution, epidemiology, pathogenicity and resistance, threatening infection treatment. The influence of RMS on antimicrobial and bacteriophage therapy needs urgent investigation.


2020 ◽  
Vol 64 (12) ◽  
Author(s):  
Ana M. Rada ◽  
Elsa De La Cadena ◽  
Carlos Agudelo ◽  
Cesar Capataz ◽  
Nataly Orozco ◽  
...  

ABSTRACT Carbapenem-resistant Enterobacterales (CRE) pose a significant threat to global public health. The most important mechanism for carbapenem resistance is the production of carbapenemases. Klebsiella pneumoniae carbapenemase (KPC) represents one of the main carbapenemases worldwide. Complex mechanisms of blaKPC dissemination have been reported in Colombia, a country with a high endemicity of carbapenem resistance. Here, we characterized the dynamics of dissemination of blaKPC gene among CRE infecting and colonizing patients in three hospitals localized in a highly endemic area of Colombia (2013 and 2015). We identified the genomic characteristics of KPC-producing Enterobacterales recovered from patients infected/colonized and reconstructed the dynamics of dissemination of blaKPC-2 using both short and long read sequencing. We found that spread of blaKPC-2 among Enterobacterales in the participating hospitals was due to intra- and interspecies horizontal gene transfer (HGT) mediated by promiscuous plasmids associated with transposable elements that was originated from a multispecies outbreak of KPC-producing Enterobacterales in a neonatal intensive care unit. The plasmids were detected in isolates recovered in other units within the same hospital and nearby hospitals. The gene “epidemic” was driven by IncN-pST15-type plasmids carrying a novel Tn4401b structure and non-Tn4401 elements (NTEKPC) in Klebsiella spp., Escherichia coli, Enterobacter spp., and Citrobacter spp. Of note, mcr-9 was found to coexist with blaKPC-2 in species of the Enterobacter cloacae complex. Our findings suggest that the main mechanism for dissemination of blaKPC-2 is HGT mediated by highly transferable plasmids among species of Enterobacterales in infected/colonized patients, presenting a major challenge for public health interventions in developing countries such as Colombia.


mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Roberto Adamo ◽  
Immaculada Margarit

ABSTRACT Antibiotics and vaccines have greatly impacted human health in the last century by dramatically reducing the morbidity and mortality associated with infectious diseases. The recent challenge posed by the emergence of multidrug-resistant bacteria could possibly be addressed by novel immune prophylactic and therapeutic approaches. Among the newly threatening pathogens, Klebsiella pneumoniae is particularly worrisome in the nosocomial setting, and its surface polysaccharides are regarded as promising antigen candidates. The majority of Klebsiella carbapenem-resistant strains belong to the sequence type 158 (ST258) lineage, with two main clades expressing capsular polysaccharides CPS1 and CPS2. In a recent article, S. D. Kobayashi and colleagues (mBio 9:e00297-18, 2018, https://doi.org/10.1128/mBio.00297-18) show that CPS2-specific IgGs render ST258 clade 2 bacteria more sensitive to human serum and phagocytic killing. E. Diago-Navarro et al. (mBio 9:e00091-18, 2018, https://doi.org/10.1128/mBio.00091-18) generated two murine monoclonal antibodies recognizing distinct glycotopes of CPS2 that presented functional activity against multiple ST258 strains. These complementary studies represent a step toward the control of this dangerous pathogen.


2018 ◽  
Vol 62 (10) ◽  
Author(s):  
Thea Brennan-Krohn ◽  
Alejandro Pironti ◽  
James E. Kirby

ABSTRACTResistance to colistin, a polypeptide drug used as an agent of last resort for the treatment of infections caused by multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacteria, including carbapenem-resistantEnterobacteriaceae(CRE), severely limits treatment options and may even transform an XDR organism into one that is pan-resistant. We investigated the synergistic activity of colistin in combination with 19 antibiotics against a collection of 20 colistin-resistantEnterobacteriaceaeisolates, 15 of which were also CRE. All combinations were tested against all strains using an inkjet printer-assisted digital dispensing checkerboard array, and the activities of those that demonstrated synergy by this method were evaluated against a single isolate in a time-kill synergy study. Eighteen of 19 combinations demonstrated synergy against two or more isolates, and the 4 most highly synergistic combinations (colistin combined with linezolid, rifampin, azithromycin, and fusidic acid) were synergistic against ≥90% of strains. Sixteen of 18 combinations (88.9%) that were synergistic in the checkerboard array were also synergistic in a time-kill study. Our findings demonstrate that colistin in combination with a range of antibiotics, particularly protein and RNA synthesis inhibitors, exhibits synergy against colistin-resistant strains, suggesting that colistin may exert a subinhibitory permeabilizing effect on the Gram-negative bacterial outer membrane even in isolates that are resistant to it. These findings suggest that colistin combination therapy may have promise as a treatment approach for patients infected with colistin-resistant XDR Gram-negative pathogens.


2020 ◽  
Vol 64 (10) ◽  
Author(s):  
Po-Yu Liu ◽  
Yu-Lin Lee ◽  
Min-Chi Lu ◽  
Pei-Lan Shao ◽  
Po-Liang Lu ◽  
...  

ABSTRACT A multicenter collection of bacteremic isolates of Escherichia coli (n = 423), Klebsiella pneumoniae (n = 372), Pseudomonas aeruginosa (n = 300), and Acinetobacter baumannii complex (n = 199) was analyzed for susceptibility. Xpert Carba-R assay and sequencing for mcr genes were performed for carbapenem- or colistin-resistant isolates. Nineteen (67.8%) carbapenem-resistant K. pneumoniae (n = 28) and one (20%) carbapenem-resistant E. coli (n = 5) isolate harbored blaKPC (n = 17), blaOXA-48 (n = 2), and blaVIM (n = 1) genes.


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