Evidence for transmission between humans and the environment of a nosocomial strain of Enterococcus faecium.
An ampicillin- and ciprofloxacin-resistant Enterococcus faecium (ARE) strain, named FMSE1, with a characteristic biochemical phenotype, was in a recent study found to dominate among faecal ARE isolates from patients in several Swedish hospitals. In the present study, the prevalence of this strain among 9676 enterococcal isolates from healthy children, hospital sewage, urban sewage, surface water, slaughtered animals (broilers, pigs and cattle) and pig faeces and manure was investigated. Enterococcal isolates having the same biochemical phenotype as the FMSE1 were most common in samples of hospital sewage (50%), surface water (35%), treated sewage (28%) and untreated sewage (17%), but rare in samples from healthy children (0.8%) and animals (2%). PFGE typing of FMSE1-like isolates from hospital sewage indicated that they were closely related to the nosocomial FMSE1 strain. Thus, this study indicated a possible transmission route for nosocomial E. faecium from patients in hospitals to hospital sewage and urban sewage, and further via treatment plants to surface water and possibly back to humans. This proposed route of circulation of drug-resistant enterococci might be further amplified by antibiotic usage in human medicine. In contrast, such transmission from food animals seems to play a negligible role in Sweden.
Iversen
Aina
A
Microbiology and Tumor Biology Center, Karolinska Institutet, SE-171 77 Stockholm, Sweden. aina.iversen@mtc.ki.se
Kühn
Inger
I
Rahman
Mokhlasur
M
Franklin
Anders
A
Burman
Lars G
LG
Olsson-Liljequist
Barbro
B
Torell
Erik
E
Möllby
Roland
R
D000668:Ampicillin Resistance; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D002353:Carrier State / Q000382:microbiology; D002417:Cattle; D002645:Chickens / Q000382:microbiology; D002939:Ciprofloxacin / Q000494:pharmacology; D003428:Cross Infection / Q000382:microbiology*; D016172:DNA Fingerprinting; D024881:Drug Resistance, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D016984:Enterococcus faecium / Q000302:isolation & purification* / Q000502:physiology*; D005243:Feces / Q000382:microbiology; D005618:Fresh Water / Q000382:microbiology; D005838:Genotype; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D010641:Phenotype; D012722:Sewage / Q000382:microbiology; D013552:Swine / Q000382:microbiology
D000890:Anti-Infective Agents; D012722:Sewage; D002939:Ciprofloxacin