Salmonella isolated in sewage sludge traced back to human cases of salmonellosis.
OBJECTIVE
The main aim of this study was to investigate a possible connection between the Salmonella content in sewage sludge and human cases of salmonellosis. An additional aim was to survey the antimicrobial resistance situation in Salmonella isolated from Swedish sewage sludge.


RESULTS
The Salmonella strains were compared by restriction enzyme analysis combined with pulsed field gel electrophoresis and antimicrobial susceptibility testing. This study suggests a link between Salmonella isolated from sewage sludge and human Salmonella isolates.


CONCLUSIONS
This study demonstrates that Salmonella spp. isolated in sewage treatment plants (STP) originate from infected humans and survive treatment at STP. It also highlights the risk of spreading resistant Salmonella strains from sewage sludge to the environment.


CONCLUSIONS
As Salmonella spp. originating from infected humans can survive the treatment at STP, the risk of Salmonella spp. being spread with sewage sludge to the environment and then to people and animals is enhanced. The threat to society is even worse if the bacteria are resistant to antimicrobial agents.
Sahlström
L
L
National Veterinary Institute, Uppsala, Sweden. Leena.Sahlstrom@sva.se
de Jong
B
B
Aspan
A
A
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D008826:Microbial Sensitivity Tests; D012475:Salmonella / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D012480:Salmonella Infections / Q000453:epidemiology / Q000382:microbiology*; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000379:methods*
D000900:Anti-Bacterial Agents; D012722:Sewage