Triton Hodge Test for Detection of Metallo-Β-Lactamases Producing Pseudomonas Aeruginosa Isolates from Egyptian Patients with Infected Diabetic Foot

Abstract

Background: One of the dreadful complications of diabetes is infected diabetic foot. Accurate detection of carbapenemase-producing Pseudomonas aeruginosa, in the form of metallo-beta-lactamases (MBLs) is necessary to determine the antibiotics for its treatment. Objectives: This study was designed to evaluate the efficacy of Triton Hodge Test (THT) versus MHT for detection of MBLs-producing P. aeruginosa isolates from infected diabetic foot patients. Methodology: Samples were collected from 500 infected diabetic footpatients. They were processed and P. aeruginosa isolates were identified. Then, carbapenem resistant P. aeruginosa (CRPA)isolates weredetected. Modified Hodge test (MHT) and Triton Hodge Test (THT) were used for detectionof MBLs. Furthermore, bla IMP , bla VIM and bla NDM MBLs genes were detected by multiplex and uniplex PCR. Resistance pattern of CRPA isolates was determined. Results: Isolation rate of P. aeruginosa from infected diabetic foot patients was 90/500 (18.00%). CRPA isolates were 16/90 (17.78%). In these isolates, the detection rate of bla NDM , bla VIM and bla IMP genes was (2/16, 12.5%), (10/16,62.5%) and (6/16,37.5%); respectively. The sensitivity, specificity and accuracy of THT in detection of NDM, VIM and IMP carbapenemases are 100 %. On the other hand, the sensitivity of MHT in detection of the studied types are 0.0%, 30.0% and 50.0%; respectively. Its specificity is 100% for all types and its accuracy is 87.5%, 56.3% and 83.1% in detection of these types. No resistance to tigecycline and colistin was detected among CRPA isolates. Conclusion: the THT is a more sensitive and accurate phenotypic test in comparison to MHT for detection of NDM, VIM and IMP carbapenemases in CRPA isolates.