mCIM test as a reliable assay for the detection of CRE in the Gulf region

Abstract

Introduction. Carbapenem resistant Enterobacterales (CRE) are one of the leading causes of systemic and nosocomial infections and are multidrug-resistant organisms producing different carbapenemases. There are many genotypic and phenotypic methods for detecting the carbapenemases; however, there is a limitation for each. Modified carbapenem inactivation method (mCIM) assay is a recent phenotypic method which has been published by the Clinical and Laboratory Standards Institute. Hypothesis / Gap Statement. mCIM assay could provide a reliable method for the detection of carbapenemases in CRE. Aim. Evaluation of the mCIM assay performance for the detection of carbapenemases in Enterobacterales and the identification of the common carbapenemase genes at Eastern Province of Saudi Arabia and Kingdom of Bahrain. Methodology. A collection of 197 non-duplicate carbapenem resistant Enterobacterales clinical isolates, were evaluated with the mCIM test comparing its performance to multiplex PCR. The minimum inhibitory concentration susceptibility testing was done by the Etest method for imipenem, meropenem, and ertapenem. Results. The sensitivity of the mCIM assay was 94 % (95 % CI, (89.3–97.1)). In Saudi Arabia and Bahrain, OXA-48 was the most prevalent carbapenemase gene followed by NDM. Coexistence of multiple carbapenemase genes is reported in eleven cases. Conclusion. These findings indicate that the mCIM test is a reliable and simple assay for detecting the activity of carbapenemase in Enterobacterales , especially in resource-limited laboratories.

Predictive role of culture-based MIC testing vs. genotyping for carbapenem-resistant Enterobacterales in a non-universal screening, highly resourced setting

“…Whilst new β-lactam-β-lactamase inhibitor combinations such as ceftazidime-avibactam, and meropenem-vaborbactam can be potential therapeutic agents for infections caused by the serine carbapenemases, they do not offer coverage for metallo-carbapenemases such as NDM or IMP. Earlier studies in the Arabian Gulf Peninsula have consistently shown the predominance of the OXA-48 family among CRE, which support the current findings shown in Figure 1 [40][41][42]. This is in contrast to the USA, where another serine-carbapenemase "KPC" has been described as the most frequent genotype in K. pneumoniae [43][44][45].…”