Evaluation of the Hyplex®MBL ID multiplex PCR-ELISA system for direct detection of blaVIM and blaIMP genes in blood and other clinical material
Abstract number: P2000
Kraniotaki E., Avlami A., Bekris S., Ganteris G., Malamou-Lada E., Orfanidou M., Paniara O., Papagiannitsis C., Platsouka E., Stefanou I., Tzelepi E., Vagiakou E., Miriagou V.
Objectives: Hyplex®MBL ID Multiplex PCR-ELISA (BAG Health Care, Germany) is a new diagnostic method for the direct detection of metallo-b-lactamase (MBL) genes of the VIM and IMP types in clinical specimens. The method was tested in Greek hospitals, characterised by high prevalence of MBL-producing isolates.
Methods: The hyplex®MBL ID method involves amplification of blaVIM/blaIMP bacterial DNA by multiplex PCR and hybridisation of the PCR products to specific oligonucleotide probes in an ELISA-based format. The method was applied to 326 samples obtained during September 2007 in three Athens hospitals. These included 90 positive blood culture bottles containing at least one Gram-negative species and 236 consecutively collected samples including urine (n = 60), pus swabs (n = 91) and bronchial secretions (n = 85). Results were compared to those of a blaVIM/IMP PCR screening of the isolated Gram-negative bacteria.
Results: Nineteen of the 90 blood cultures were positive by the hyplex®MBL ID. blaVIM-1- or blaVIM-2-carrying isolates (8 Pseudomonas aeruginosa, 9 Klebsiella pneumoniae, 1 Providencia stuartii and 1 Enterobacter aerogenes) were isolated from all hyplex-positive samples. blaVIM-carrying isolates were not identified in any of the hyplex-negative samples (sensitivity and specificity 100%). Five of the urine samples containing blaVIM carriers (2 P. aeruginosa and 3 K. pneumoniae) were positive by the hyplex®MBL ID; MBL-positive organisms were not detected from 2 hyplex-positive samples. Eight of the 9 pus samples with VIM-producers (5 P. aeruginosa, 2 K. pneumoniae and 1 E. cloacae) were also positive by hyplex®MBL ID; one sample appeared hyplex-positive but MBL producers were not isolated; blaVIM was also identified in 1 hyplex-negative P. aeruginosa isolate. In respiratory samples the hyplex®MBL ID method classified as positive 40 samples containing VIM-producers; MBL producers were not isolated from 2 hyplex-positive respiratory samples. Sensitivity and specificity of the hyplex®MBL ID system for specimens other than blood were 98% and 97%, respectively.
Conclusion: The hyplex®MBL ID test can be reliably applied for the timely detection of blaVIM carriage by Gram-negative species in positive blood cultures in this setting. The assay is also efficient in detecting MBL genes in other clinical specimens however, the diagnostic utility of this approach remains to be evaluated.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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