[Prevalence of antibiotic resistant Enterococcus spp in waste waters in the north of Chile].
BACKGROUND
There is little information available in Chile on the distribution of Enterococcus spp in waste water and its implications in transmission of antibiotic resistance through the water cycle. Enterococcus spp are common in nosocomial infections and may spread antibiotic resistance through the food chain.


OBJECTIVE
To determine the presence of antibiotic resistant Enterococcus spp in the sewage of Antofagasta, Chile.


METHODS
Samples of sewage from two sewage treatment plants and from the Public Hospital of Antofagasta collector were obtained. Enterococcus spp were isolated on m-Enterococcus agar containing ampicillin, vancomycin and streptomycin. The isolates were identified and subjected to biochemical typing (PhPlate). Minimal inhibitory concentration determination was performed by agar dilution technique.


RESULTS
High counts of resistant Enterococcus spp were found on the streptomycin plates, lower on ampicillin and very low on vancomycin plates. A total of 63 Enterococcus spp strains were typed and the identification showed 5 different species; E faecalis (65%), E faecium (14%), E hirae (13%), E durans (6%) and E gallinarum (2%). The typing revealed a high diversity among the isolates. Two biochemical phenotypes were predominant, C1 (21 strains) and C6 (7 strains). Both were highly resistant to gentamycin and streptomycin; moderately resistant to ampicillin, chloramphenicol, tetracycline and ciprofloxacin, and with intermediate susceptibility to vancomycin. Both phenotypes were found in the sewage of the hospital collector and in the treatment plants.


CONCLUSIONS
In the sewage of Antofagasta we found dominating phenotypes of multiresistant Enterococcus spp. Sewage could be an important way of transmission of these microorganisms.
Silva
Juan
J
Departamento de Tecnología Médica, INDES, Universidad de Antofagasta, Chile. jsilva@uantof.cl
Loyola
Patricio
P
Galleguillos
Juan
J
Rodríguez
Yara
Y
Colque-Navarro
Patricia
P
Möllby
Roland
R
Kühn
Inger
I
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002677:Chile; D024881:Drug Resistance, Bacterial / Q000235:genetics; D016983:Enterococcus / Q000187:drug effects* / Q000302:isolation & purification; D005839:Gentamicins / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D012722:Sewage / Q000382:microbiology*; D013307:Streptomycin / Q000494:pharmacology; D014640:Vancomycin / Q000494:pharmacology; D014865:Waste Disposal, Fluid; D014871:Water Microbiology
D000900:Anti-Bacterial Agents; D005839:Gentamicins; D012722:Sewage; D014640:Vancomycin; D013307:Streptomycin