Carba np test method for rapid detection of pseudomonas aeruginosa isolates producing carbapenemase enzymes.

Masoumeh Beig,1,*



The increasing resistance to carbapenems is a global clinical worry. the carba np test is a biochemical test with high sensitivity and specificity, and much shorter than the methods based on the culture in detection of carbapenemase producer isolates. the purpose of this study is to evaluated of sensivity,specifity,ppv,npvof the carba np test to quickly recognize carbapenemase producing isolates.


A collection of 49 carbapenemase-producing pseudomonas aeroginosa. isolates (including 11 kpc,20 imp ,19 vim, 25ampc,35 oxa48 producers) and 48 non-cpe isolates as confirmed by the pcr methods were tested by the carbanp method .


The results of pcr showed that the highest gene prevalence was among the strains of the oxa48 gene (35.5%) and the least of them was kpc gene (11/34%). of the 49 (50/51%) that carbapenem genes were positive by pcr, 48 (48.49%) had positive carbanp assays and out of 48 (49/48%) that had negative pcr results for the carbapenem gene, 48 (49/48%) of their carbanp test were negative. therefore, the sensitivity,specifity,ppv and npv of this test was 100% ,96%,100 and 96% respectively.the specificity of the test was 96%.


The results of this study showed that a high percentage of p. aeruginosa was resistant to carbapenem antibiotics and the carbanp method was highly sensitive and specific for identification of such resistant isolates.


Pseudomonas aeruginosa, pcr, carbanp