Epidemiology and Infection

Research Article

Sink flora in a long-stay hospital is determined by the patients' oral and rectal flora

Hendrik K. F. Van Saenea1, Jeannet C. Van Puttea2, Joris J. M. Van Saenea2, Thomas W. Van De Grondea3 and Eduard G. A. Van Warmerdama3

a1 Department of Medical Microbiology, University of Liverpoo, P.O. Box 147, Liverpool L69 3BX, UK

a2 Department of Pharmaceutical Technology and Dispensing, University of Groningen, Antonius Deusinglaan 2, 9713 AW Groningen, The Netherlands

a3 Long Stay Hospital Innersdyk, Ypemaheerd 2a, 9736 MA Groningen, The Netherlands


Sinks in a new long-stay hospital (LSH) were cultured weekly during 4 consecutive months to evaluate the microbial profile before and after occupancy of the hospital. From the elderly patients admitted to the patient care rooms oral and rectal specimens were collected to examine the contribution of the patients' flora to the sink contamination. Isolates were typed biochemically, serologically and by susceptibility pattern. Before occupancy Gram-negative bacilli were not isolated. Once the elderly patients, who were highly colonized on admission, occupied their rooms identical strains gradually contaminated the sinks. Escherichia coli, Klebsiella, Pseudomonas and Acinetobacter species were the major correlating strains. The mean concentration of the correlating isolates was higher in throat and intestines compared to the mean concentration of the non- correlating strains. These strains seem to have a greater chance to be shed and then transferred via the hands of personnel to sinks. This resport shows that the major route of environmental contamination is from patient carriers to sinks, and not the reverse way.

(Accepted August 25 1988)