IJAA Editor's Choice

Two articles have been selected as 'Editor's Choice' for the December issue of IJAA.

1. Repurposing the Veterinary Antiprotozoal Drug Ronidazole for the Treatment of Clostridioides difficile Infection (AbdelKhalek and Seleem)

Editor's comment:
Clostridium difficile infections are a major cause of death worldwide, mostly healthcare-associated infections. This infection has been monitored epidemiologically by the US Centers for Disease Control and Prevention (CDC) for several years, with this organization alerting to the increase in cases of C. difficile colitis. Treatment is based on the use of vancomycin, fidaxomicin or metronidazole. The use of fecal transplantation, to restore a healthy fecal flora, is also a therapeutic option. However, the development of new molecules is necessary due to the high price of the first two molecules and the moderate efficacy of metronidazole. The authors of this work applied the molecular repositioning method and screened 3,200 FDA-approved drugs against C. difficile. They thus demonstrated the efficacy of ronidazole, another nitroimidazole used for its antiprotozoal properties in veterinary medicine. Ronidazole showed superior efficacy to metronidazole in in vitro and in vivo animal studies but was inferior to vancomycin. This work shows the interest of molecular repositioning for the treatment of severe infections.

2. Immunomodulatory Effects of Colistin on Host Responses against Carbapenem-resistant Klebsiella pneumoniae Biofilms (Geladari et al)

Editor's comment:
The authors of this work explored the recently shown in vitro antibiofilm action of colistin at subinhibitory concentrations. They were particularly interested in the interactions between colistin and immune cells in a model of carbapenemase-producing K. pneumoniae infection, focusing on the antibiofilm action of this association. The results showed an additive effect of colistin and human neutrophils on biofilm disruption. Colistin, at a concentration of 0.5 mg/L, decreases the pro-inflammatory cytokine production (IL-1b, TNFa, IL-8, IL-6) induced by K. pneumoniae. On the other hand, at higher concentrations, it increases the production of anti-inflammatory cytokines IL-10. This work provides new data on the immunomodulatory effect of colistin.