Discrepancies in susceptibility testing to colistin in Acinetobacter baumannii: The influence of slow growth and heteroresistance.

The increasing use of polymyxins as last-resort drugs for managing infections by Acinetobacter baumannii has led to the emergence of resistance. This study aimed to determine the resistance mechanisms in Acinetobacter baumannii isolates with colistin MIC ≥ 4 mg/L and to relate the mechanisms of resistance with the difficulties in detecting them. Absolute agreement among the different methodologies (Phoenix automatized system, broth and agar dilution, and a rapid colorimetric test) in the 140 colistin-susceptible isolates was observed; whereas in the 25 resistant isolates, the performance varied according to the colistin MIC value.

[Genotyping of Cryptococcus neoformans/Cryptococcus gattii complex clinical isolates from Hospital "Dr. Julio C. Perrando", Resistencia city (Chaco, Argentina)].

Cryptococcosis is a fungal infection caused by yeast species of Cryptococcus genus, particularly Cryptococcus neoformans/Cryptococcus gattii species complex. The knowledge of the cryptococcosis casuistic in northeastern Argentina is scarce and there is no information about the molecular types circulating in this area. The aim of this study was to genotyping C.