Plasmid-encoded resistance to arsenic compounds in Gram-negative bacteria isolated from a hospital environment in Venezuela.
Resistance to arsenic compounds was examined among amikacin resistant Gram-negative bacteria isolate from a hospital environment. Arsenite resistance (Ars(r)) was found in a high proportion of isolates ( >60%) being frequently associated with resistance to tellurite (40%), and to other antimicrobial agents. Ars determinants (27%) were found to be transferable to E. coli K12 strains from which large plasmid DNA molecules were isolated and characterized by agarose gel electrophoresis. Plasmids were identified by both classical incompatibility tests, and by replicon typing using DNA specific probes. Most of the amikacin-arsenite (Ak-Ars) conjugative plasmids belong to the H incompatibility group. These results suggest that Ak-Ars resistance linked to IncH plasmids is wide spread in Gram-negative bacteria.
Pedroza
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R
Instituto de Medicina Experimental (IME), Facultad de Medicina, Universidad Central de Venezuela, Apartado 50 587, Venezuela.
Ramírez
A
A
Alonso
G
G
Rodríguez Lemoine
V
V