Comparison of Lateral Flow Immunochromatography and Phenotypic Assays to PCR for the Detection of Carbapenemase-Producing Gram-Negative Bacteria, a Multicenter Experience in Mexico

Abstract

The identification of carbapenemase-producing Enterobacterales and Pseudomonas aeruginosa is important for treating and controlling hospital infections. The recommended methods for their identification require a long waiting time, technical training, and expertise. Lateral flow immunoassays such as NG-Test CARBA 5® overcome these needs. We analyzed 84 clinical isolates of carbapenem-resistant Enterobacterales and P. aeruginosa from four different hospitals in a two-year period. Antimicrobial resistance patterns were confirmed with the broth dilution method. Evaluation of KPC, VIM, NDM, IMP, and OXA-48-like enzymes was performed and compared to NG-Test CARBA 5 and phenotypic assays. Enterobacterales represented 69% of isolates and P. aeruginosa represented 31%. Carbapenemase-producing strains were 51 (88%) of Enterobacterales and 23 (88.4%) of P. aeruginosa; 20 (34%) and 23 (88%) were Class B ß-lactamases, respectively. The NG-Test CARBA 5® assay for Enterobacterales showed high sensitivity (98%), specificity (100%), and PPV (100%); however, it did not for P. aeruginosa. The Kappa concordance coefficient was 0.92 for Enterobacterales and 0.52 for P. aeruginosa. NG-Test CARBA 5® is a fast and easy-to-use assay. In Enterobacterales, we found excellent agreement in our comparison with molecular tests. Despite the low agreement in P. aeruginosa, we suggest that this test could be used as a complementary tool.

Carbapenem-Resistant Gram-Negative Bacilli Characterization in a Tertiary Care Center from El Bajio, Mexico

“…The use of point-of-care tests, such as NG-test CARBA-5 ® , is a good complementary option to guide antimicrobial therapy since they have shown excellent performances compared with molecular techniques and provide results within 15–30 min. However, it should be considered that they do not detect all types of carbapenemases, as seen with bla GES in our sample, and may not perform as well for P. aeruginosa [ 33 ].…”

“…To identify metallo ß-lactamase-producing strains, we used the mCIM variant, with EDTA (ethylenediaminetetraacetic acid) as a chelator (eCIM) [ 42 ]. Once the producer strain was identified, the next step was to identify the protein involved through NG-test CARBA-5 ® [ 33 ] (KPC, OXA-48, VIM, IMP, and NDM). (eCIM).…”

Replacement of the Double Meropenem Disc Test with a Lateral Flow Assay for the Detection of Carbapenemase-Producing Enterobacterales and Pseudomonas aeruginosa in Clinical Laboratory Practice

“…In recent years, rapid diagnostic testing using LFAs for the detection of enzymes associated with antimicrobial resistance have been widely developed as they demonstrate comparable performance with gold standard PCR-based methods and can be easily applied in clinical microbiology laboratories without requiring specialized personnel and excessive cost [ 21 , 22 , 23 , 24 , 25 ].…”

Antibiotic Resistance in Bacterial Pathogens

“…In terms of diagnosis, rapid tools focused on lateral flow systems are being developed, especially for betalactamases [ 9 ] and carbapenemases [ 10 ] detection.…”