Spreading of AbaR-type genomic islands in multidrug resistance Acinetobacter baumannii strains belonging to different clonal complexes.

In order to determine the occurrence of AbaR-type genomic island in multidrug resistant Acinetobacter baumannii (MDRAb) strains circulating in Argentina, Uruguay, and Chile, we studied 51 MDRAb isolates recovered from several hospitals over 30 years. AbaR-type genomic resistance islands were found in 36 MDRAb isolates since 1986 till now. MLST technique allowed us to identify the presence of four different Clonal Complexes (109, 104, 119, 113) among the positive AbaR-type island positive strains.

First report of qacG, qacH and qacJ genes in Staphylococcus haemolyticus human clinical isolates.

Objectives: To investigate phenotypically and genotypically the presence of MDR efflux pumps in 21 clinical isolates of Staphylococcus haemolyticus collected over a period of 10 years.

Methods: MICs of different antibiotics and biocides were determined by the broth dilution method in the presence/absence of carbonyl cyanide-m-chlorophenylhydrazone (CCCP), an efflux pump inhibitor. PCR followed by sequencing was performed to detect the qac genes that encode for antiseptic resistance.

Survey of molecular determinants in Gram-positive cocci isolated from hospital settings in Argentina.

Background: In order to study the resistance mechanisms to aminoglycosides, tetracyclines and erythromycin, we investigated the genetic determinants on 85 Streptococcus spp., Staphylococcus spp., and Enterococcus spp.

Molecular characterization of methicillin-resistant Staphylococcus aureus isolates reveals the spreading of a new clone in Buenos Aires City.

We performed a hospital-acquired methicillin-resistant Staphylococcus aureus molecular study in Buenos Aires city. Four clones were found harboring the transposable elements Tn4001 and Tn5405 and the erythromycin resistance determinants ermA and mef(E). Of the isolates, 73% belonged to a clone found previously in the city of Córdoba, which showed an epidemic behavior initially attributed to the widely disseminated South American clone.