From the Research
The CLSI does not recommend the I + EDTA method for metallo-beta-lactamase (mbl) gene detection because this methodology has not been validated for reliable and accurate detection of the mbl gene. The combination of iodine and EDTA can interfere with the molecular testing processes typically used for gene detection, potentially leading to false results. Standard molecular techniques such as polymerase chain reaction (PCR), real-time PCR, or sequencing are the preferred methods for gene detection as they provide higher sensitivity and specificity, as seen in studies such as 1 and 2. Additionally, the I + EDTA method may cause chemical interactions that degrade DNA quality, making it unsuitable for precise genetic analysis. For proper mbl gene detection, laboratories should follow validated molecular diagnostic protocols that include appropriate DNA extraction methods, specific primers for the mbl gene, and controls to ensure accurate results. Some studies, like 3 and 2, have evaluated the use of EDTA in combination with other methods for detecting metallo-beta-lactamase production, but these do not support the use of I + EDTA for gene detection. The most recent and highest quality studies, such as 2, emphasize the importance of using validated molecular techniques for accurate detection of the mbl gene. Therefore, the use of standard molecular techniques is recommended over the I + EDTA method for mbl gene detection. Key considerations in choosing a detection method include the need for high sensitivity and specificity, as well as the potential for chemical interactions to interfere with test results, as discussed in 1 and 4. By prioritizing validated molecular diagnostic protocols, laboratories can ensure accurate and reliable detection of the mbl gene.