Multicenter study on spreading of the tet(M) gene in tetracycline-resistant Streptococcus group G and C isolates in Argentina

A prospective multicenter study on invasive infections caused by beta-hemolytic streptococci was performed over 6 months and involved 42 centers from 16 cities in Argentina. Among 33 isolates recovered, 9 group G Streptococcus isolates (39.1%) and 2 group C Streptococcus isolates (20%) exhibited resistance to tetracycline and harbored the tet(M) gene. Genealogical analysis revealed that tetracycline resistance has a polyclonal origin in Argentina.

Survival of Acinetobacter baumannii on bed rails during an outbreak and during sporadic cases

Genotypic methods showed Acinetobacter baumannii biotype 9 genotype I to be the epidemic strain on an outbreak in an intensive care unit (ICU) which lasted from January to April of 1996. A cohort was established during March in which hospital personnel were assigned exclusively to A. baumannii infected or colonized patients. New patients were not admitted to the ICU until the last infected patient was discharged. However, strain I was isolated during April and vectors other than human carriage were suspected. The ICU comprised four sections; patients and beds were moved within them according the severity of diseases. Strain I was isolated from a bed rail nine days after the infected patient was discharged. This dry vector may explain the transmission of the epidemic strain between sections. The following July, four new infected patients were identified and three different strains, including the epidemic one, were recovered. The two other strains were also isolated from a bed rail. Although this environmental source does not explain by itself the transmission of an epidemic strain, it illustrates that dry vectors can be secondary reservoirs where A. baumannii can survive.