scholarly journals Evaluation of the EDTA-Modified Carbapenem Inactivation Method for Detecting Metallo-β-Lactamase-Producing Pseudomonas aeruginosa

2020 ◽  
Vol 58 (6) ◽  
Author(s):  
Christian M. Gill ◽  
Maxwell J. Lasko ◽  
Tomefa E. Asempa ◽  
David P. Nicolau

ABSTRACT The prevalence of carbapenem-resistant Pseudomonas aeruginosa is increasing. Identification of carbapenemase-producing P. aeruginosa will have therapeutic, epidemiological, and infection control implications. This study evaluated the performance of the EDTA-modified carbapenem inactivation method (eCIM) in tandem with the modified carbapenem inactivation method (mCIM) against a large collection of clinical P. aeruginosa isolates (n = 103) to provide clinicians a phenotypic test that not only identifies carbapenemase production but also distinguishes between metallo-β-lactamase and serine-carbapenemase production in P. aeruginosa. The mCIM test was performed according to Clinical and Laboratory Standards Institute guidelines, while the eCIM was conducted as previously described for Enterobacteriaceae. Test performance was compared to the genotypic profile as the reference. mCIM testing successfully categorized 91% (112/123) of P. aeruginosa isolates as carbapenemases or non-carbapenemase producers, with discordant isolates being primarily Guiana extended-spectrum (GES)-type producers. To increase the sensitivity of the mCIM for GES-harboring isolates, a double inoculum, prolonged incubation, or both was evaluated, with each modification improving sensitivity to 100% (12/12). Upon eCIM testing, all Verona integrin-encoded metallo-β-lactamases (VIM; n = 27) and New Delhi metallo-β-lactamases (NDM; n = 13) tested had 100% concordance to their genotypic profiles, whereas all Klebsiella pneumoniae carbapenemase (KPC; n = 8) and GES (n = 12) isolates tested negative, as expected, in the presence of EDTA. The eCIM failed to identify all imipenemase (IMP)-producing (n = 22) and Sao Paulo metallo-β-lactamase (SPM)-producing (n = 14) isolates. KPC-, VIM-, and NDM-producing P. aeruginosa were well defined by the conventional mCIM and eCIM testing methods; additional modifications appear required to differentiate GES-, IMP-, and SPM-producing isolates.

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.


2013 ◽  
Vol 58 (3) ◽  
pp. 1763-1767 ◽  
Author(s):  
L. V. Perdigão-Neto ◽  
M. S. Oliveira ◽  
C. F. Rizek ◽  
C. M. D. M. Carrilho ◽  
S. F. Costa ◽  
...  

ABSTRACTFosfomycin may be a treatment option for multiresistant Gram-negative bacteria. This study compared susceptibility methods using 94 multiresistant clinical isolates. With agar dilution (AD), susceptibilities were 81%, 7%, 96%, and 100% (CLSI) and 0%, 0%, 96%, and 30% (EUCAST), respectively, forAcinetobacter baumannii,Pseudomonas aeruginosa,Klebsiella pneumoniae, andEnterobacterspp. Categorical agreement between Etest and AD forEnterobacteriaceaeandA. baumanniiwas ≥80%. Disk diffusion was adequate only forEnterobacter. CLSI criteria for urine may be adequate for systemic infections.


2021 ◽  
Vol 70 (12) ◽  
Author(s):  
Taalin R. Hoj ◽  
Bradley McNeely ◽  
Kylie Webber ◽  
Evelyn Welling ◽  
William G. Pitt ◽  
...  

Introduction. Antibiotic resistance, particularly in cases of sepsis, has emerged as a growing global public health concern and economic burden. Current methods of blood culture and antimicrobial susceptibility testing of agents involved in sepsis can take as long as 3–5 days. It is vital to rapidly identify which antimicrobials can be used to effectively treat sepsis cases on an individual basis. Here, we present a pentaplex, real-time PCR-based assay that can quickly identify the most common beta-lactamase genes ( Klebsiella pneumoniae carbapenemase (KPC); New Delhi metallo-beta-lactamase (NDM); cefotaximase-Munich (CTX-M); cephamycin AmpC beta-lactamases (CMY); and Oxacillinase-48 (OXA-48)) from pathogens derived directly from the blood of patients presenting with bacterial septicemia. Aim. To develop an assay which can rapidly identify the most common beta-lactamase genes in Carbapenem-resistant Enterobacteriaceae bacteria (CREs) from the United States. Hypothesis/Gap Statement. Septicemia caused by carbapenem-resistant bacteria has a death rate of 40–60 %. Rapid diagnosis of antibiotic susceptibility directly from bacteria in blood by identification of beta-lactamase genes will greatly improve survival rates. In this work, we develop an assay capable of concurrently identifying the five most common beta-lactamase and carbapenemase genes. Methodology. Primers and probes were created which can identify all subtypes of Klebsiella pneumoniae carbapenemase (KPC); New Delhi metallo-beta-lactamase (NDM); cefotaximase-Munich (CTX); cephamycin AmpC beta-lactamase (CMY); and oxacillinase-48 (OXA-48). The assay was validated using 13 isolates containing various PCR targets from the Centre for Disease Control Antimicrobial Resistance Isolate Bank Enterobacterales Carbapenemase Diversity Panel. Blood obtained from volunteers was spiked with CREs and bacteria were separated, lysed, and subjected to analysis via the pentaplex assay. Results. This pentaplex assay successfully identified beta-lactamase genes derived from bacteria separated from blood at concentrations of 4–8 c.f.u. ml−1. Conclusion. This assay will improve patient outcomes by supplying physicians with critical drug resistance information within 2 h of septicemia onset, allowing them to prescribe effective antimicrobials corresponding to the resistance gene(s) present in the pathogen. In addition, information supplied by this assay will lessen the inappropriate use of broad-spectrum antimicrobials and prevent the evolution of further antibiotic resistance.


2018 ◽  
Vol 62 (7) ◽  
Author(s):  
Safa S. Almarzoky Abuhussain ◽  
Joseph L. Kuti ◽  
David P. Nicolau

ABSTRACT The role of inhalational combination therapy when treating carbapenem-resistant Pseudomonas aeruginosa and Klebsiella pneumoniae with newer beta-lactam/beta-lactamase inhibitors has not been established. Using a 72-h in vitro pharmacodynamic chemostat model, we simulated the human exposures achieved in epithelial lining fluid (ELF) following intravenous treatment with ceftazidime-avibactam (CZA) 2.5 g every 8 h (q8h) alone and in combination with inhaled amikacin (AMK-I) 400 mg q12h, a reformulated aminoglycoside designed for inhalational administration, against three P. aeruginosa isolates (CZA [ceftazidime/avibactam] MICs, 4/4 to 8/4 μg/ml; AMK-I MICs, 8 to 64 μg/ml) and three K. pneumoniae isolates (CZA MICs, 1/4 to 8/4 μg/ml; AMK-I MICs, 32 to 64 μg/ml). Combination therapy resulted in a significant reduction in 72-h CFU compared with that of CZA monotherapy against two of three P. aeruginosa isolates (−4.14 log 10 CFU/ml, P = 0.027; −1.42 log 10 CFU/ml, P = 0.020; and −0.4 log 10 CFU/ml, P = 0.298) and two of three K. pneumoniae isolates (0.04 log 10 CFU/ml, P = 0.963; −4.34 log 10 CFU/ml, P < 0.001; and −2.34 log 10 CFU/ml, P = 0.021). When measured by the area under the bacterial growth curve (AUBC) over 72 h, significant reductions were observed in favor of the combination regimen against all six isolates tested. AMK-I combination therapy successfully suppressed CZA resistance development in one K. pneumoniae isolate harboring bla KPC-3 that was observed during CZA monotherapy. These studies suggest a beneficial role for combination therapy with intravenous CZA and inhaled AMK when treating pneumonia caused by carbapenem-resistant Gram-negative bacteria.


2018 ◽  
Vol 56 (4) ◽  
Author(s):  
Yi Li ◽  
Qiao-ling Sun ◽  
Yingbo Shen ◽  
Yangjunna Zhang ◽  
Jun-wen Yang ◽  
...  

ABSTRACTThe global spread of carbapenem-resistantEnterobacteriaceae(CRE) is one of the most severe threats to human health in a clinical setting. The recent emergence of plasmid-mediated colistin resistance genemcr-1among CRE strains greatly compromises the use of colistin as a last resort for the treatment of infections caused by CRE. This study aimed to understand the current epidemiological trends and characteristics of CRE from a large hospital in Henan, the most populous province in China. From 2014 to 2016, a total of 7,249Enterobacteriaceaeisolates were collected from clinical samples, among which 18.1% (1,311/7,249) were carbapenem resistant. Carbapenem-resistantKlebsiella pneumoniaeand carbapenem-resistantEscherichia coliwere the two most common CRE species, withKlebsiella pneumoniaecarbapenemases (KPC) and New Delhi metallo-β-lactamases (NDM), respectively, responsible for the carbapenem resistance of the two species. Notably, >57.0% (n= 589) of theK. pneumoniaeisolates from the intensive care unit were carbapenem resistant. Furthermore,blaNDM-5andmcr-1were found to coexist in oneE. coliisolate, which exhibited resistance to almost all tested antibiotics. Overall, we observed a significant increase in the prevalence of CRE isolates during the study period and suggest that carbapenems may no longer be considered to be an effective treatment for infections caused byK. pneumoniaein the studied hospital.


2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Silva Tafaj ◽  
Floriana Gona ◽  
Célia F. Rodrigues ◽  
Perlat Kapisyzi ◽  
Fatmir Caushi ◽  
...  

Isolation of metallo-β-lactamase-producing, carbapenem-resistant, Pseudomonas aeruginosa strains is increasingly being documented worldwide; their presence constitutes a public health threat. Here, we report draft genome sequences of two New Delhi metallo-β-lactamase-1-producing, multidrug-resistant, P. aeruginosa strains of sequence type 235 that were isolated from the surgical wound of two patients hospitalized in the same ward.


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.


Author(s):  
Jaffar A Al-Tawfiq ◽  
Ali A Rabaan ◽  
Justin V Saunar ◽  
Ali M Bazzi

Abstract Background The molecular epidemiology of resistance of carbapenem-resistant Enterobacteriaceae (CRE) and Pseudomonas aeruginosa are important in the study of multidrug-resistant bacteria. We evaluate the prevalence of the different mechanisms of CRE in a hospital in Saudi Arabia. Methods Carbapenem non-susceptible isolates of Enterobacteriaceae and Pseudomonas aeruginosa were tested by real-time PCR for the detection of genes responsible for beta-lactam resistance. Results There were a total of 200 isolates with carbapenem non-susceptibility and these were Klebsiella pneumoniae (n=96, 48%), Escherichia coli (n=51, 25.5%) and Pseudomonas aeruginosa (n=45, 22.5%). The detected carbapenemases were oxacillinase-48 (OXA-48) (n=83, 41.5%), New Delhi metallo-β-lactamase (NDM) (n=19, 2.5%) and both NDM and OXA-48 (n=5, 2.5%). The other carbapenemases were imipenemase (n=1, 0.5%), Verona integrin encoded metallo-β-lactamase (n=6, 3%) and Klebsiella pneumoniae carbapenemase (n=1, 0.5%), but none were detected in 86 isolates (43%). Conclusion The most common carbapenemases were OXA-48 and a significant percentage had no detectable genes. These data will help in the selection of new antimicrobial therapies.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S88-S88
Author(s):  
Samuel Simon ◽  
Rosanna Li ◽  
Yu Shia Lin ◽  
Suri Mayer ◽  
Edward Chapnick ◽  
...  

Abstract Background Carbapenem-resistant gram-negative organisms are a continuously mounting threat, underscoring the need for effective antimicrobial stewardship interventions to improve the use of carbapenems. We sought to implement several multidisciplinary antimicrobial stewardship interventions beginning in January 2019 in an effort to reduce unnecessary meropenem use and the incidence of carbapenem-resistant gram-negatives. Methods Prospective audit and feedback was utilized daily in combination with weekly stewardship rounds between an Infectious Diseases pharmacist and physician in the Intensive Care Units. A second Infectious Diseases physician attended weekly interdisciplinary rounds on meropenem high-use units. Meropenem Days of Therapy (DOT) per 1,000 patient days and the incidence of meropenem resistant Pseudomonas aeruginosa and Klebsiella pneumoniae were compared by the chi-square test of proportions. Results Between 2018 and 2019 the institution’s meropenem DOT per 1,000 patient days decreased 33%, from 57 to 38 days per 1,000 patient days (difference, 19 days per 1,000 patient days; p&lt; 0.001). In the hospital antibiogram, the meropenem susceptibility of Pseudomonas aeruginosa over the same time period increased from 71% to 77% of isolates (difference, 6%; p = 0.009). A non-significant decrease in the susceptibility of meropenem to Klebsiella pneumoniae was also observed from 92 to 90% (difference, 2%: p = 0.1658). Conclusion These data support the need for antimicrobial stewardship efforts targeting broad-spectrum antimicrobials such as meropenem. In the setting of a sustained decrease in meropenem use over 12 months, we observed a significant improvement in the percent susceptibility rate of Pseudomonas aeruginosa to meropenem for the first time in five years. Disclosures All Authors: No reported disclosures


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