Infection and Drug Resistance (Mar 2018)
Moxalactam is not more active on extended spectrum β-lactamase (ESBL) producing bacteria than on non-ESBL producers
Abstract
Bhoj R Singh Division of Epidemiology, ICAR-Indian Veterinary Research Institute, Izatnagar, IndiaIn a recently published article1 moxalactam has been claimed to be very effective on extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae, concluding “MOX demonstrated excellent bactericidal effect, which is worthy of further exploration to serve as an alternative therapeutic agent against ESBL-producing Enterobacteriaceae”. Similar claims have also been made earlier.2 Out of interest we examined antimicrobial sensitivity data with reference to sensitivity to moxalactam, carbapenem resistant, and extended-spectrum β-lactamase (EBSL) and metallo-β-lactamase (MBL) production, among clinically important bacteria from the last 6 years (2011–2017), available from the Division of Epidemiology at Indian Veterinary Research Institute, Izatnagar. The analysis (Figure 1) revealed that conclusions drawn earlier1,2 on the basis of a study on a few strains may not be valid. My analysis revealed that of the 3,242 bacteria tested in our laboratory, using Clinical and Laboratory Standards Institute3 guidelines, 50.6% were identified as ESBL producers. Observations further revealed that moxalactam was certainly a more effective antibiotic on clinically important bacteria than most of the extended spectrum β-lactam antibiotics but no significant difference was detected between ESBL and non-ESBL producer bacteria with respect to their sensitivity to carbapenem (meropenem, imipenem and ertapenem), moxalactam and aztreonam. However, non-ESBL producing bacteria were more often positive for MBL production (p <0.001) than ESBL producing bacteria. Therefore, it may be suggested that observations on a few strains should not be used to draw a generalized statement the moxalactam is more effective on ESBL producer strains. It may give false message for misuse or undue preferences for moxalactum use. View the original paper by Huang and colleagues.
