THE EVALUATION OF BACTERIAL COLONIZATION ON DOUBLE-J URETERAL STENTS

Abstract

Abstract

Introduction: Urological infections and bacteriuria are most commonly observed complications after

double-j stent applications. In this study we aimed to compare the relationship between the colonization of the

bladder urine and the colonization on the double-j stents which had been inserted for various reasons.

Materials and Methods: The average age of 39 patients (21 male, 18 female) in whom silicone double-j

stents were applied, was 41 (range 18-78) years. The average period of time with the double-j stents was 75 (30-

210) days. 2-3 cm pieces from the top, mid and bottom parts of the removed stents together with the patients’

urine was taken for bacteriological investigation. 100 ml of broth was taken separately from tubes containing

non-diluted and 1/100 diluted samples and were inoculated on to Blood Agar and Eosin Methylene Blue

(EMB) agar. Microorganisms which grew on the agar were quantitatively evaluated (growth of >1000 CFU/ml

was considered meaningful). Bacteria were identified via the conventional method.

Results: Bacterial colonization was observed in 53.8% of the 39 stents which we removed from our

patients. The most frequently isolated microorganisms from the stents were found to be E. coli (n=6) and

enterococci (n=6). No relationship was observed with gender and stent colonization. While 20% colonization

was observed in stents in the first 30 days, rapid increase of colonization formed after the 61st day (85.7%).

However, after 91 days, all the stents were observed to be colonized. The presence of colonization was observed

to increase meaningfully as the presence of the stent increased (p<0.05).

When the bladder urine was investigated, growth was identified in 9 patients (23%). While E. coli (n=4)

was founded to be the microorganism which grew the most, Enterococci (n=4) was found to be the bacteria

which most frequently colonized the stents. In cases where growth was observed in both the bladder urine and

the double-j stents, a more intense colonization was observed on the double-j stents rather than the bladder

urine. The type of bacteria which colonized in the bladder urine and on the double-j stent was observed to be

of the same type. When growth was present in the bladder urine, growth was definitely present on the double-j

stent. However, growth was not observed in the bladder urine of 3 patients who had growth on the double-j

stent.

Conclusion: As a result, double-j stents cause widespread bacterial colonization. Urine cultures are not

always a determinant factor in identifying this. Colonization starts on the first day and reaches 100% in

permanent stents. Because fluoroquinolones, which are antibiotics widely used in urological practices, have a

short durational effect on the biofilm layer and because of the occurrence of the reformation of the biofilm

layer after 1-2 weeks has shown us that routine antibiotic use in stents should be abandoned. Taking

advantage of the increased use of catheters coated with antibiotic or bactericidal agents in recent years, in

order to avoid or to minimize stent colonization, it is reasonable to expect the modification of these stents

according to these principles.