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 .
Aim: To determine the presence of
antibiotic resistant
Enterococcus spp in the
sewage of Antofagasta,
Chile . Material and
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 , cloramphenicol,
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.