Investigating the potential use of an Antarctic variant of Janthinobacterium lividum for tackling antimicrobial resistance in a One Health approach

Andreea Baricz,Amalia Dascălu,Adela Teban,Maria Nica,Corina Oprișan,Anca Farkas,Cristian Coman,Edina Szekeres,Cecilia Maria Chiriac,Paris Lavin

doi:10.1038/s41598-018-33691-6

Abstract

The aim of this paper is to describe a new variant of Janthinobacterium lividum - ROICE173, isolated from Antarctic snow, and to investigate the antimicrobial effect of the crude bacterial extract against 200 multi-drug resistant (MDR) bacteria of both clinical and environmental origin, displaying various antibiotic resistance patterns. ROICE173 is extremotolerant, grows at high pH (5.5–9.5), in high salinity (3%) and in the presence of different xenobiotic compounds and various antibiotics. The best violacein yield (4.59 ± 0.78 mg·g−1 wet biomass) was obtained at 22 °C, on R2 broth supplemented with 1% glycerol. When the crude extract was tested for antimicrobial activity, a clear bactericidal effect was observed on 79 strains (40%), a bacteriostatic effect on 25 strains (12%) and no effect in the case of 96 strains (48%). A very good inhibitory effect was noticed against numerous MRSA, MSSA, Enterococci, and Enterobacteriaceae isolates. For several environmental E. coli strains, the bactericidal effect was encountered at a violacein concentration below of what was previously reported. A different effect (bacteriostatic vs. bactericidal) was observed in the case of Enterobacteriaceae isolated from raw vs. treated wastewater, suggesting that the wastewater treatment process may influence the susceptibility of MDR bacteria to violacein containing bacterial extracts.

Highlights

IntroductionSince their discovery (e.g., penicillin in 1928), antibiotics have changed the face of medicine, saving millions of lives from deadly infections
Since their discovery, antibiotics have changed the face of medicine, saving millions of lives from deadly infections
The majority of multi-drug resistant (MDR) strains tested in these studies were clinical isolates, with a special attention given to methicillin-resistant Staphylococcus aureus (MRSA), limiting the perspectives for application of violacein/bacterial extracts with violacein

Summary

Introduction

Since their discovery (e.g., penicillin in 1928), antibiotics have changed the face of medicine, saving millions of lives from deadly infections. Antarctica has proven to be a rich source of novel microbial species with increased potential for various applications, including the discovery of antimicrobial compounds[8,9,10]. Specific objectives were set: (i) to characterize a new variant of J. lividum, isolated from Antarctica and investigate its phenotypic and phylogenetic traits, together with the violacein yield; (ii) to test the violacein-containing extract against 200 MDR bacteria isolated from clinical and raw/treated wastewater samples, with different AMR patterns; (iii) to discuss the strain’s biotechnological potential in designing new strategies to reduce the burden of antibiotic resistance in a One Health approach, aimed at improving both human and environmental health

Objectives

Methods

Results