Current trends in colistin susceptibility testing methods in enteric Gram-negative bacilli and other non-fermentative pathogens

Abstract

Polymyxins, an age-old sort of cationic polypeptide antibiotic, are regarded as final-resort drugs in handling infections caused by multidrug-resistant Gram-negative bacteria. An exact assessment of colistin susceptibility is crucial due to increasing colistin resistance and absence of other antibiotics in curing multidrug resistance pathogens. Both Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing have investigated colistin broth microdilution and offer particular recommendations, but this method has a challenging perform in routine daily practice. It is time consuming and requires ≥48 h. In this issue, several alternative rapid tests are developed such as ResaPolymyxin Acinetobacter/Pseudomonas NP. The sensitivity and specificity of 100% for the Rapid ResaPolymyxin Acinetobacter/Pseudomonas NP test to Enterobacterales have been reported. Colistin broth disk elution test and colistin agar test are another novel potential methods that were validated by the Clinical laboratory standard institutes subcommittee for colistin screening in the Enterobacterales and Pseudomonas aeruginosa. In addition, recently, Rapid flow cytometry (FASTinov) method was introduced which requires only 2 h compared with conventional methods. This review will take a look at current trends on methods for colistin resistance measurements.