Introduction: Multi Drug Resistant Organisms (MDROs) pose a major threat in health care facilities across the globe as most of these bugs are recalcitrant to therapy. Polymyxins emerged as a lifesaving option to treat invasive infections with MDROs. However, in the recent past the CLSI - EUCAST joint recommendations are for the use of broth microdilution (BMD) for susceptibility testing for polymyxins. However, the procedure of BMD for polymyxins is tedious. To limit the use of polymyxins, selective reporting is done excluding polymyxins in reports.
Methods: This retrospective study was conducted at a tertiary care facility in South India over a period of two years from January 2017 to December 2018.2200Gram negative isolates were included, among which 15.8% of Multi Drug Resistant Gram negatives were further tested. Susceptibility to Chloramphenicol, Doxycycline, Tigecycline, Minocycline, Fosfomycin by Kirby Bauer disk diffusion or E-test for MIC determination was performed. Results were entered into WHONET software (2016 version) for further analysis and susceptibility pattern was determined.
Results: Among theEnterobacteriaceae,76.7% were susceptible to Fosfomycin, 32.4% to Doxycycline, 29.2% to Tigecycline, 29.1% to Chloramphenicol, 15.45% to Minocycline. Among Acinetobacterbaumanniiisolates,65% were susceptible to Minocycline, 63.6% to Tigecycline, 41.9% to Doxycycline.
Conclusion: Since there are few newer antimicrobials in the pipeline, it is wise to keep polymyxins as reserve drugs.Multidrug resistant bugs including A.baumannii show good susceptibility to the above mentioned antibiotics. Variation in species specific susceptibility was observed.Hence they can be used as alternatives to polymyxins based on their susceptibility and patient condition.
