scholarly journals In VitroSusceptibility of Characterized β-Lactamase-Producing Strains Tested with Avibactam Combinations

2014 ◽  
Vol 59 (3) ◽  
pp. 1789-1793 ◽  
Author(s):  
Henry Li ◽  
Mark Estabrook ◽  
George A. Jacoby ◽  
Wright W. Nichols ◽  
Raymond T. Testa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Broad Spectrum ◽  
Enterobacter Cloacae ◽  
Gram Negative ◽  
Content Type ◽  
Extended Spectrum ◽  
Lactamase Inhibitor

ABSTRACTAvibactam, a broad-spectrum β-lactamase inhibitor, was tested with ceftazidime, ceftaroline, or aztreonam against 57 well-characterized Gram-negative strains producing β-lactamases from all molecular classes. Most strains were nonsusceptible to the β-lactams alone. Against AmpC-, extended-spectrum β-lactamase (ESBL)-, and KPC-producingEnterobacteriaceaeorPseudomonas aeruginosa, avibactam lowered ceftazidime, ceftaroline, or aztreonam MICs up to 2,048-fold, to ≤4 μg/ml. Aztreonam-avibactam MICs against a VIM-1 metallo-β-lactamase-producingEnterobacter cloacaeand a VIM-1/KPC-3-producingEscherichia coliisolate were 0.12 and 8 μg/ml, respectively.

scholarly journals Extended-Spectrum β-Lactamases in the 21st Century: Characterization, Epidemiology, and Detection of This Important Resistance Threat

2001 ◽  
Vol 14 (4) ◽  
pp. 933-951 ◽  
Author(s):  
Patricia A. Bradford
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
21St Century ◽  
Broad Spectrum ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Significant Percentage ◽  
Extended Spectrum ◽  
The World

SUMMARY β-Lactamases continue to be the leading cause of resistance to β-lactam antibiotics among gram-negative bacteria. In recent years there has been an increased incidence and prevalence of extended-spectrum β-lactamases (ESBLs), enzymes that hydrolyze and cause resistance to oxyimino-cephalosporins and aztreonam. The majority of ESBLs are derived from the widespread broad-spectrum β-lactamases TEM-1 and SHV-1. There are also new families of ESBLs, including the CTX-M and OXA-type enzymes as well as novel, unrelated β-lactamases. Several different methods for the detection of ESBLs in clinical isolates have been suggested. While each of the tests has merit, none of the tests is able to detect all of the ESBLs encountered. ESBLs have become widespread throughout the world and are now found in a significant percentage of Escherichia coli and Klebsiella pneumoniae strains in certain countries. They have also been found in other Enterobacteriaceae strains and Pseudomonas aeruginosa. Strains expressing these β-lactamases will present a host of therapeutic challenges as we head into the 21st century.

scholarly journals Comparison of the Superpolymyxin and ChromID Colistin R Screening Media for the Detection of Colistin-Resistant Enterobacteriaceae from Spiked Rectal Swabs

2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Delphine Girlich ◽  
Thierry Naas ◽  
Laurent Dortet
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Confidence Interval ◽  
Enterobacter Cloacae ◽  
Bacterial Isolates ◽  
Colistin Resistance ◽  
Gram Negative ◽  
Content Type ◽  
Rectal Swabs ◽  
Stool Samples

ABSTRACT The dissemination of carbapenemase-producing Enterobacteriaceae (CPE) has led to the increased use of colistin, which has resulted in the emergence of colistin-resistant Enterobacteriaceae worldwide. One of the most threatening scenarios is the dissemination of colistin resistance in CPE, particularly the plasmid-encoded resistance element MCR. Thus, it has now become mandatory to possess reliable media to screen for colistin-resistant Gram-negative bacterial isolates, especially Enterobacteriaceae. In this study, we evaluated the performances of the Superpolymyxin medium (ELITechGroup) and the ChromID Colistin R medium (bioMérieux) to screen for colistin-resistant Enterobacteriaceae from spiked rectal swabs. Stool samples were spiked with a total of 94 enterobacterial isolates (Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Enterobacter cloacae), including 53 colistin-resistant isolates. ESwabs (Copan Diagnostics) were then inoculated with those spiked fecal suspensions, and culture proceeded as recommended by both manufacturers. The sensitivity of detection of colistin-resistant Enterobacteriaceae was 86.8% (95% confidence interval [95% CI] = 74.0% to 94.0%) using both the Superpolymyxin medium and the ChromID Colistin R plates. Surprisingly, the isolates that were not detected were not the same for both media. The specificities were high for both media, at 97.9% (95% CI = 87.3% to 99.9%) for the Superpolymyxin medium and 100% (95% CI = 90.4% to 100%) for the ChromID Colistin R medium. Both commercially available media, ChromID Colistin R and Superpolymyxin, provide useful tools to screen for colistin-resistant Enterobacteriaceae from patient samples (rectal swabs) regardless of the level and mechanism of colistin resistance.

scholarly journals Ceftazidime-Avibactam Resistance Mediated by the N346Y Substitution in Various AmpC β-Lactamases

2020 ◽  
Vol 64 (6) ◽  
Author(s):  
Fabrice Compain ◽  
Agathe Debray ◽  
Pauline Adjadj ◽  
Delphine Dorchêne ◽  
Michel Arthur
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Resistance Mechanism ◽  
Enterobacter Cloacae ◽  
Common Mechanism ◽  
Citrobacter Freundii ◽  
Content Type ◽  
Hydrogen Interaction ◽  
Y Substitution ◽  
Lactamase Inhibitor

ABSTRACT Chromosomal and plasmid-borne AmpC cephalosporinases are a major resistance mechanism to β-lactams in Enterobacteriaceae and Pseudomonas aeruginosa. The new β-lactamase inhibitor avibactam effectively inhibits class C enzymes and can fully restore ceftazidime susceptibility. The conserved amino acid residue Asn346 of AmpC cephalosporinases directly interacts with the avibactam sulfonate. Disruption of this interaction caused by the N346Y amino acid substitution in Citrobacter freundii AmpC was previously shown to confer resistance to the ceftazidime-avibactam combination (CAZ-AVI). The aim of this study was to phenotypically and biochemically characterize the consequences of the N346Y substitution in various AmpC backgrounds. Introduction of N346Y into Enterobacter cloacae AmpC (AmpCcloacae), plasmid-mediated DHA-1, and P. aeruginosa PDC-5 led to 270-, 12,000-, and 79-fold decreases in the inhibitory efficacy (k2/Ki) of avibactam, respectively. The kinetic parameters of AmpCcloacae and DHA-1 for ceftazidime hydrolysis were moderately affected by the substitution. Accordingly, AmpCcloacae and DHA-1 harboring N346Y conferred CAZ-AVI resistance (MIC of ceftazidime of 16 μg/ml in the presence of 4 μg/ml of avibactam). In contrast, production of PDC-5 N346Y was associated with a lower MIC (4 μg/ml) since this β-lactamase retained a higher inactivation efficacy by avibactam in comparison to AmpCcloacae N346Y. For FOX-3, the I346Y substitution did not reduce the inactivation efficacy of avibactam and the substitution was highly deleterious for β-lactam hydrolysis, including ceftazidime, preventing CAZ-AVI resistance. Since AmpCcloacae and DHA-1 display substantial sequence diversity, our results suggest that loss of hydrogen interaction between Asn346 and avibactam could be a common mechanism of acquisition of CAZ-AVI resistance.

scholarly journals Inactivation of the Pseudomonas -Derived Cephalosporinase-3 (PDC-3) by Relebactam

2018 ◽  
Vol 62 (5) ◽  
Author(s):  
Melissa D. Barnes ◽  
Christopher R. Bethel ◽  
Jim Alsop ◽  
Scott A. Becka ◽  
Joseph D. Rutter ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Gram Negative ◽  
Content Type ◽  
Life Threatening ◽  
Lactamase Inhibitor

ABSTRACT Pseudomonas aeruginosa is a prevalent and life-threatening Gram-negative pathogen. Pseudomonas -derived cephlosporinase (PDC) is the major inducible cephalosporinase in P. aeruginosa . In this investigation, we show that relebactam, a diazabicyclooctane β-lactamase inhibitor, potently inactivates PDC-3, with a k 2 / K of 41,400 M −1 s −1 and a k off of 0.00095 s −1 . Relebactam restored susceptibility to imipenem in 62% of multidrug-resistant P. aeruginosa clinical isolates, while only 21% of isolates were susceptible to imipenem-cilastatin alone. Relebactam promises to increase the efficacy of imipenem-cilastatin against P. aeruginosa .

scholarly journals National Surveillance of Antimicrobial Susceptibility of Bacteremic Gram-Negative Bacteria with Emphasis on Community-Acquired Resistant Isolates: Report from the 2019 Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART)

2020 ◽  
Vol 64 (10) ◽  
Author(s):  
Po-Yu Liu ◽  
Yu-Lin Lee ◽  
Min-Chi Lu ◽  
Pei-Lan Shao ◽  
Po-Liang Lu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Gram Negative Bacteria ◽  
National Surveillance ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Carbapenem Resistant

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.

Susceptibility of Gram-negative bacteria to the synergistic bactericidal action of serum and polymyxin B nonapeptide

1986 ◽  
Vol 32 (1) ◽  
pp. 66-69 ◽  
Author(s):  
Petri Viljanen ◽  
Helena Käyhty ◽  
Martti Vaara ◽  
Timo Vaara
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Enterobacter Cloacae ◽  
Polymyxin B ◽  
Gram Negative Bacteria ◽  
Bactericidal Action ◽  
Gram Negative ◽  
Degree Of Sensitization ◽  
Normal Human ◽  
Klebsiella Spp

Polymyxin B nonapeptide was able to sensitize Escherichia coli strains and strains of Salmonella typhimurium, Klebsiella spp., Enterobacter cloacae, Pseudomonas aeruginosa, and Haemophilus influenzae to the bactericidal action of fresh normal human serum. The degree of sensitization varied significantly within the strains. Strains of Proteus mirabilis, Neisseria gonorrhoeae, and N. meningitidis remained resistant.

scholarly journals Surfing Motility: a Conserved yet Diverse Adaptation among Motile Bacteria

2018 ◽  
Vol 200 (23) ◽  
Author(s):  
Evelyn Sun ◽  
Sijie Liu ◽  
Robert E. W. Hancock
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Broad Spectrum ◽  
Proteus Mirabilis ◽  
Salmonella Enterica ◽  
Bacterial Species ◽  
Content Type ◽  
Adaptive Resistance ◽  
Sensing Systems

ABSTRACTBacterial rapid surfing motility is a novel surface adaptation ofPseudomonas aeruginosain the presence of the glycoprotein mucin. Here, we show that other Gram-negative motile bacterial species, includingEscherichia coli,Salmonella enterica,Vibrio harveyi,Enterobacter cloacae, andProteus mirabilis, also exhibit the physical characteristics of surfing on the surface of agar plates containing 0.4% mucin, where surfing motility was generally more rapid and less dependent on medium viscosity than was swimming motility. As previously observed inPseudomonas aeruginosa, all surfing species exhibited some level of broad-spectrum adaptive resistance, although the antibiotics to which they demonstrated surfing-mediated resistance differed. Surfing motility inP. aeruginosawas found to be dependent on the quorum-sensing systems of this organism; however, this aspect was not conserved in other tested bacterial species, includingV. harveyiandS. enterica, as demonstrated by assaying specific quorum-sensing mutants. Thus, rapid surfing motility is a complex surface growth adaptation that is conserved in several motile bacteria, involves flagella, and leads to diverse broad-spectrum antibiotic resistance, but it is distinct in terms of dependence on quorum sensing.IMPORTANCEThis study showed for the first time that surfing motility, a novel form of surface motility first discovered inPseudomonas aeruginosaunder artificial cystic fibrosis conditions, including the presence of high mucin content, is conserved in other motile bacterial species known to be mucosa-associated, includingEscherichia coli,Salmonella enterica, andProteus mirabilis. Here, we demonstrated that key characteristics of surfing, including the ability to adapt to various viscous environments and multidrug adaptive resistance, are also conserved. Using mutagenesis assays, we also identified the importance of all three known quorum-sensing systems, Las, Rhl, and Pqs, inP. aeruginosain regulating surfing motility, and we also observed a conserved dependence of surfing on flagella in certain species.

scholarly journals Post-β-Lactamase-Inhibitor Effect of Tazobactam in Combination with Ceftolozane on Extended-Spectrum-β-Lactamase-Producing Strains

2014 ◽  
Vol 58 (4) ◽  
pp. 2434-2437 ◽  
Author(s):  
Helio S. Sader ◽  
Paul R. Rhomberg ◽  
Ronald N. Jones
Keyword(s):  
Escherichia Coli ◽  
Postantibiotic Effect ◽  
Content Type ◽  
Extended Spectrum ◽  
Time Kill ◽  
Lactamase Inhibitor

ABSTRACTThe post-β-lactamase-inhibitor effect (PBLIE) of tazobactam combined with ceftolozane was evaluated by time-kill assays on two clinicalEscherichia colistrains producing CTX-M-15 with or without TEM-1. The organisms were exposed (2 h) to 4 μg/ml/4 μg/ml of ceftolozane-tazobactam (4× MIC), 4 μg/ml of ceftolozane, and medium containing no drug, washed, and resuspended in medium alone or medium containing ceftolozane-tazobactam or ceftolozane. The PBLIE was determined as 1.3 to 2.1 h, and a postantibiotic effect was measured as 0.8 to 0.9 h.

scholarly journals In VitroActivities of 21 Antimicrobial Agents Alone and in Combination with Aminoglycosides or Fluoroquinolones against Extended-Spectrum-β-Lactamase-Producing Escherichia coli Isolates Causing Bacteremia

2015 ◽  
Vol 59 (9) ◽  
pp. 5834-5837 ◽  
Author(s):  
Min Kyeong Cha ◽  
Cheol-In Kang ◽  
So Hyun Kim ◽  
Sun Young Cho ◽  
Young Eun Ha ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Therapy ◽  
Antimicrobial Agents ◽  
Empirical Therapy ◽  
Gram Negative ◽  
Content Type ◽  
South Korean ◽  
Extended Spectrum ◽  
High Prevalence

ABSTRACTWe evaluated thein vitroactivity of various antimicrobials alone and in combination against 291 extended-spectrum-β-lactamase-producingEscherichia coli(ESBL-EC) isolates causing bacteremia in South Korean hospitals. Ceftazidime, cefepime, and piperacillin-tazobactam in combination with amikacin showed greater activity than found in combination with ciprofloxacin. In settings with a high prevalence of ESBL-producing pathogens, combination aminoglycoside antimicrobial therapy, especially with amikacin, may be considered for empirical therapy against suspected Gram-negative sepsis as a carbapenem-saving strategy.

scholarly journals ARGONAUT-I: Activity of Cefiderocol (S-649266), a Siderophore Cephalosporin, against Gram-Negative Bacteria, Including Carbapenem-Resistant Nonfermenters and Enterobacteriaceae with Defined Extended-Spectrum β-Lactamases and Carbapenemases

2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Michael R. Jacobs ◽  
Ayman M. Abdelhamed ◽  
Caryn E. Good ◽  
Daniel D. Rhoads ◽  
Kristine M. Hujer ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acinetobacter Baumannii ◽  
Stenotrophomonas Maltophilia ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Extended Spectrum ◽  
Mueller Hinton ◽  
Mueller Hinton Broth

ABSTRACT The activity of the siderophore cephalosporin cefiderocol is targeted against carbapenem-resistant Gram-negative bacteria. In this study, the activity of cefiderocol against characterized carbapenem-resistant Acinetobacter baumannii complex, Stenotrophomonas maltophilia, Pseudomonas aeruginosa, and Enterobacteriaceae strains was determined by microdilution in iron-depleted Mueller-Hinton broth. The MIC90s against A. baumannii, S. maltophilia, and P. aeruginosa were 1, 0.25, and 0.5 mg/liter, respectively. Against Enterobacteriaceae, the MIC90 was 1 mg/liter for the group harboring OXA-48-like, 2 mg/liter for the group harboring KPC-3, and 8 mg/liter for the group harboring TEM/SHV ESBL, NDM, and KPC-2.

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