scholarly journals Multicenter Evaluation of the Modified Carbapenem Inactivation Method and the Carba NP for Detection of Carbapenemase-Producing Pseudomonas aeruginosa and Acinetobacter baumannii

2017 ◽  
Vol 56 (1) ◽  
Author(s):  
Patricia J. Simner ◽  
J. Kristie Johnson ◽  
William B. Brasso ◽  
Karen Anderson ◽  
David R. Lonsway ◽  
...  

ABSTRACT The purpose of this study was to develop the modified carbapenem inactivation method (mCIM) for the detection of carbapenemase-producing Pseudomonas aeruginosa (CP-PA) and carbapenemase-producing Acinetobacter baumannii (CP-AB) and perform a multicenter evaluation of the mCIM and Carba NP tests for these nonfermenters. Thirty P. aeruginosa and 30 A. baumannii isolates previously characterized by whole-genome sequencing from the CDC-FDA Antibiotic Resistance Isolate Bank were evaluated, including CP isolates (Ambler class A, B, and D), non-carbapenemase-producing (non-CP) carbapenem-resistant isolates, and carbapenem-susceptible isolates. Initial comparison of a 1-μl versus 10-μl loop inoculum for the mCIM was performed by two testing sites and showed that 10 μl was required for reliable detection of carbapenemase production among P. aeruginosa and A. baumannii. Ten testing sites then evaluated the mCIM using a 10-μl loop inoculum. Overall, the mean sensitivity and specificity of the mCIM for detection of CP-PA across all 10 sites were 98.0% (95% confidence interval [CI], 94.3 to 99.6; range, 86.7 to 100) and 95% (95% CI, 89.8 to 97.7; range, 93.3 to 100), whereas the mean sensitivity and specificity among CP-AB were 79.8% (95% CI, 74.0 to 84.9; range, 36.3 to 95.7) and 52.9% (95% CI, 40.6 to 64.9; range, 28.6 to 100), respectively. At three sites that evaluated the performance of the Carba NP test using the same set of isolates, the mean sensitivity and specificity of the Carba NP test were 97.8% (95% CI, 88.2 to 99.9; range, 93.3 to 100) and 97.8% (95% CI, 88.2 to 99.9; range, 93.3 to 100) for P. aeruginosa and 18.8% (95% CI, 10.4 to 30.1; range, 8.7 to 26.1) and 100% (95% CI, 83.9 to 100; range, 100) for A. baumannii. Overall, we found both the mCIM and the Carba NP test to be accurate for detection of carbapenemase production among P. aeruginosa isolates and less reliable for use with A. baumannii isolates.

2015 ◽  
Vol 53 (9) ◽  
pp. 3003-3008 ◽  
Author(s):  
Laurent Poirel ◽  
Patrice Nordmann

Performances of the Rapidec Carba NP test (bioMérieux) were evaluated for detection of all types of carbapenemases inEnterobacteriaceae,Acinetobacter baumannii, andPseudomonas aeruginosa. In less than 2 h after sample preparation, it showed a sensitivity and specificity of 96%. This ready-to-use test is well adapted to the daily need for detection of carbapenemase producers in any laboratory worldwide.


2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Lindsay M. Avery ◽  
Kamilia Abdelraouf ◽  
David P. Nicolau

ABSTRACT We evaluated the in vivo efficacy of human-simulated WCK 5222 (cefepime-zidebactam) against cefepime-resistant Acinetobacter baumannii strains (n = 13) in the neutropenic murine lung infection model. Twelve isolates were meropenem resistant. In control animals and those that received cefepime or zidebactam alone, the mean bacterial growth at 24 h was >2 log10 CFU/lung compared with 0-h controls (6.32 ± 0.33 log10 CFU/lung). WCK 5222 produced a decline in the bacterial burden for all isolates (mean reduction, −3.34 ± 0.85 log10 CFU/lung) and demonstrated remarkable potency.


2018 ◽  
Vol 62 (3) ◽  
Author(s):  
Shu-Chen Kuo ◽  
Wei-Cheng Huang ◽  
Tzu-Wen Huang ◽  
Hui-Ying Wang ◽  
Jui-Fen Lai ◽  
...  

ABSTRACT The rate of recovery of carbapenem-resistant Acinetobacter baumannii (CRAB) isolates has increased significantly in recent decades in Taiwan. This study investigated the molecular epidemiology of CRAB with a focus on the mechanisms of resistance and spread in isolates with bla OXA-23-like or bla OXA-24-like . All 555 CRAB isolates in our multicenter collection, which were recovered from 2002 to 2010, were tested for the presence of class A, B, and D carbapenemase genes. All isolates with bla OXA-23-like or bla OXA-24-like were subjected to pulsed-field gel electrophoresis, and 82 isolates (60 isolates with bla OXA-23-like and 22 isolates with bla OXA-24-like ) were selected for multilocus sequence typing to determine the sequence type (ST) and clonal group (CG) and for detection of additional β-lactamase and aminoglycoside resistance genes. The flanking regions of carbapenem and aminoglycoside resistance genes were identified by PCR mapping and sequencing. The localization of bla OXA was determined by S1 nuclease and I-CeuI assays. The numbers of CRAB isolates carrying bla OXA-23-like or bla OXA-24-like , especially those carrying bla OXA-23-like , increased significantly from 2008 onward. The bla OXA-23-like gene was carried by antibiotic resistance genomic island 1 (AbGRI1)-type structures located on plasmids and/or the chromosome in isolates of different STs (CG92 and novel CG786), whereas bla OXA-24-like was carried on plasmids in CRAB isolates of limited STs (CG92). No class A or B carbapenemase genes were identified. Multiple aminoglycoside resistance genes coexisted in CRAB. Tn 6180 -borne armA was found in 74 (90.2%) CRAB isolates, and 58 (70.7%) isolates had Tn 6179 upstream, constituting AbGRI3. bla TEM was present in 38 (46.3%) of the CRAB isolates tested, with 35 (92.1%) isolates containing bla TEM in AbGRI2-type structures, and 61% of ampC genes had IS Aba1 upstream. We conclude that the dissemination and spread of a few dominant lineages of CRAB containing various resistance island structures occurred in Taiwan.


2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Michael R. Jacobs ◽  
Ayman M. Abdelhamed ◽  
Caryn E. Good ◽  
Daniel D. Rhoads ◽  
Kristine M. Hujer ◽  
...  

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.


2016 ◽  
Vol 54 (7) ◽  
pp. 1700-1710 ◽  
Author(s):  
Thomas J. Gniadek ◽  
Karen C. Carroll ◽  
Patricia J. Simner

The non-glucose-fermenting Gram-negative bacilliPseudomonas aeruginosaandAcinetobacter baumanniiare increasingly acquiring carbapenem resistance. Given their intrinsic antibiotic resistance, this can cause extremely difficult-to-treat infections. Additionally, resistance gene transfer can occur between Gram-negative species, regardless of their ability to ferment glucose. Thus, the acquisition of carbapenemase genes by these organisms increases the risk of carbapenemase spread in general. Ultimately, infection control practitioners and clinical microbiologists need to work together to determine the risk carried by carbapenem-resistant non-glucose-fermenting Gram-negative bacilli (CR-NF) in their institution and what methods should be considered for surveillance and detection of CR-NF.


2020 ◽  
Vol 65 (1) ◽  
pp. e01726-20
Author(s):  
Yang Yang ◽  
Yan Guo ◽  
Dandan Yin ◽  
Yonggui Zheng ◽  
Shi Wu ◽  
...  

ABSTRACTThis study evaluated the in vitro activity of cefepime-zidebactam in comparison with that of ceftazidime-avibactam and other comparators against clinically significant Gram-negative bacillus isolates. A total of 3,400 nonduplicate Gram-negative clinical isolates were collected from 45 medical centers across China in the CHINET Program in 2018, including Enterobacterales (n = 2,228), Pseudomonas aeruginosa (n = 657), and Acinetobacter baumannii (n = 515). The activities of cefepime-zidebactam and 20 comparators were determined by broth microdilution as recommended by the Clinical and Laboratory Standards Institute. Cefepime-zidebactam demonstrated potent activity against almost all Enterobacterales (MIC50/90, 0.125/1 mg/liter) and good activity against P. aeruginosa (MIC50/90, 2/8 mg/liter). Among the 373 carbapenem-resistant Enterobacteriaceae isolates, 57.3% (213/373) and 15.3% (57/373) were positive for blaKPC-2 and blaNDM, respectively. Cefepime-zidebactam showed a MIC of ≤2 mg/liter for 92.0% (196/213) of blaKPC-2 producers and 79.7% (47/59) of blaNDM producers. Ceftazidime-avibactam showed good in vitro activity against Enterobacterales (MIC50/90, 0.25/2 mg/liter; 94.0% susceptible) and P. aeruginosa (MIC50/90, 4/16 mg/liter; 86.9% susceptible). Ceftazidime-avibactam was active against 9.1% of carbapenem-resistant Escherichia coli isolates (63.6% were blaNDM producers) and 84.6% of Klebsiella pneumoniae isolates (74.3% were blaKPC producers). Most (90.1%) blaKPC-2 producers were susceptible to ceftazidime-avibactam. Cefepime-zidebactam demonstrated limited activity (MIC50/90, 16/32 mg/liter) against the 515 A. baumannii isolates (79.2% were carbapenem resistant), and ceftazidime-avibactam was less active (MIC50/90, 64/>64 mg/liter). Cefepime-zidebactam was highly active against clinical isolates of Enterobacterales and P. aeruginosa, including blaKPC-2-positive Enterobacterales and blaNDM-positive Enterobacterales and carbapenem-resistant P. aeruginosa. And ceftazidime-avibactam was highly active against blaKPC-2-positive Enterobacterales and carbapenem-resistant P. aeruginosa.


2020 ◽  
Vol 58 (11) ◽  
Author(s):  
Niels Pfennigwerth ◽  
Sören G. Gatermann ◽  
Barbara Körber-Irrgang ◽  
Robert Hönings

ABSTRACT The objective of this study was to evaluate the Micronaut-S carbapenemase detection microtiter plate assay for the detection of carbapenemases and Ambler class determination. The Micronaut-S carbapenemase detection microtiter plate was tested using a challenging collection of 154 carbapenemase-producing and 150 carbapenemase-negative clinical strains of Enterobacterales and Pseudomonas aeruginosa. The Micronaut-S carbapenemase detection assay was able to detect 148/154 carbapenemase producers correctly, whereas 5/150 non-carbapenemase-producing isolates tested as false positive. This resulted in an overall sensitivity of 96% and a specificity of 97%. Regarding the detection of the carbapenemase class, the sensitivities and specificities were 93%/100%, 96%/100%, and 97%/99% for class A (n = 27), class B (n = 54), and class D (n = 73) carbapenemases, respectively. The Micronaut-S carbapenemase detection microtiter plate represents an easy-to-use and valuable tool for accurate and reliable detection of carbapenemases. In addition, it provides identification of the class of carbapenemase in most cases which can provide significant therapy guidance.


2013 ◽  
Vol 57 (8) ◽  
pp. 3775-3782 ◽  
Author(s):  
Jianhui Xiong ◽  
David C. Alexander ◽  
Jennifer H. Ma ◽  
Maxime Déraspe ◽  
Donald E. Low ◽  
...  

ABSTRACTPseudomonas aeruginosa96 (PA96) was isolated during a multicenter surveillance study in Guangzhou, China, in 2000. Whole-genome sequencing of this outbreak strain facilitated analysis of its IncP-2 carbapenem-resistant plasmid, pOZ176. The plasmid had a length of 500,839 bp and an average percent G+C content of 57%. Of the 618 predicted open reading frames, 65% encode hypothetical proteins. The pOZ176 backbone is not closely related to any plasmids thus far sequenced, but some similarity to pQBR103 ofPseudomonas fluorescensSBW25 was observed. Two multiresistant class 1 integrons and several insertion sequences were identified. TheblaIMP-9-carrying integron containedaacA4→blaIMP-9→aacA4, flanked upstream by Tn21 tnpMRAand downstream by a completetnioperon of Tn402and amermodule, named Tn6016. The second integron carriedaacA4→catB8a→blaOXA-10and was flanked by Tn1403-liketnpRAand asul1-type 3′ conserved sequence (3′-CS), named Tn6217. Other features include three resistance genes similar to those of Tn5, a tellurite resistance operon, and twopiloperons. The replication and maintenance systems exhibit similarity to a genomic island ofRalstonia solanacearumGM1000. Codon usage analysis suggests the recent acquisition ofblaIMP-9. The origins of the integrons on pOZ176 indicated separate horizontal gene transfer events driven by antibiotic selection. The novel mosaic structure of pOZ176 suggests that it is derived from environmental bacteria.


2016 ◽  
Vol 60 (4) ◽  
pp. 2513-2515 ◽  
Author(s):  
Soumia Brahmi ◽  
Abdelaziz Touati ◽  
Axelle Cadière ◽  
Nassima Djahmi ◽  
Alix Pantel ◽  
...  

ABSTRACTTo determine the occurrence of carbapenem-resistantAcinetobacter baumanniiin fish fished from the Mediterranean Sea near the Bejaia coast (Algeria), we studied 300 gills and gut samples that had been randomly and prospectively collected during 1 year. After screening on selective agar media, using PCR arrays and whole-genome sequencing, we identified for the first time two OXA-23-producingA. baumanniistrains belonging to the widespread sequence type 2 (ST2)/international clone II and harboring aminoglycoside-modifying enzymes [aac(6′)-Ib andaac(3′)-I genes].


2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Mojgan Sabet ◽  
Ziad Tarazi ◽  
David C. Griffith

ABSTRACTWe have evaluated the activity of meropenem-vaborbactam against clinical isolates ofPseudomonas aeruginosaandAcinetobacter baumanniiin a neutropenic mouse thigh infection model. Data show that meropenem-vaborbactam regimens equivalent to 3-h infusions every 8 h with 2 g meropenem and 2 g vaborbactam produced bacterial killing against strains with MICs of 2 to 16 mg/liter and suggests that this combination may have utility in the treatment of infections caused byP. aeruginosaandA. baumannii.


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