RESUMEN
Aim: To define sensitivity and specificity of Vitek® 2 MICs as phenotypic screening method for carbapenemase-producing Pseudomonas aeruginosa. Materials & methods: We determined Vitek® 2 MICs of antipseudomonal antimicrobials in 130 unrelated carbapenemase-producing P. aeruginosa and 129 carbapenemase-negative P. aeruginosa isolates within a Dutch carbapenemase-surveillance database. We calculated test characteristics of single and combined antimicrobial MICs for carbapenemase production. Results: Vitek® 2 MIC above epidemiological cutoff of both imipenem and tobramycin or ciprofloxacin and tobramycin displayed a sensitivity of 96.2% and specificity of 89.6% for carbapenemase production in P. aeruginosa. Conclusion: Vitek® 2 MIC> epidemiological cut-off values seem sensitive and specific as a phenotypic screening strategy for carbapenemase-producing P. aeruginosa. Combining imipenem and tobramycin or ciprofloxacin and tobramycin performed best as a screening strategy for defining which P. aeruginosa isolates should undergo confirmatory tests for carbapenemase production.
Asunto(s)
Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa , Proteínas Bacterianas , Ciprofloxacina/farmacología , Imipenem/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/genética , Tobramicina/farmacología , beta-LactamasasRESUMEN
Aim: To show that a strain of Aeromonas hydrophila became resistant to carbapenems by interspecies transfer of a plasmid using long-read sequencing. Material & methods: Whole genome sequencing of the four isolates was done using Illumina Hiseq, while the plasmid was reconstructed using the MinION sequencer. The resistome was identified with ResFinder. Results: Whole genome sequencing and long-read sequencing showed that all isolates carried a blaVIM-1 gene located on a 165 kb incA/C plasmid. ResFinder confirmed that the resistome of the plasmid, comprising 13 resistance genes, was identical within all isolates. Discussion: Long-read sequencing using the MinION successfully reconstructed a plasmid that was identical in all isolates, providing evidence for horizontal gene transfer of this blaVIM-1 gene carrying plasmid within the patient.