Microbial diversity in biofilm infections of the urinary tract with the use of sonication techniques: Table 1

Abstract

Infections of the urinary tract account for >40% of nosocomial infections; most of these are infections in catheterized patients. Bacterial colonization of the urinary tract and catheters causes not only the particular infection but also a number of complications, for example blockage of catheters with crystallic deposits of bacterial origin, generation of gravels and pyelonephritis. Infections of urinary catheters are only rarely single-species infections. The longer a patient is catheterized, the higher the diversity of biofilm microbial communities. The aims of this study were to investigate the microbial diversity on the catheters and to compare the ability to form biofilm among isolated microbial species. The next aim was to discriminate particular causative agents of infections of the urinary tract and their importance as biofilm formers in the microbial community on the urinary catheter. We examined catheters from 535 patients and isolated 1555 strains of microorganisms. Most of the catheters were infected by three or more microorganisms; only 12.5% showed monomicrobial infection. Among the microorganisms isolated from the urinary catheters, there were significant differences in biofilm-forming ability, and we therefore conclude that some microbial species have greater potential to cause a biofilm-based infection, whereas others can be only passive members of the biofilm community.

Reclassification of the Candida haemulonii Complex as Candida haemulonii (C. haemulonii Group I), C. duobushaemulonii sp. nov. (C. haemulonii Group II), and C. haemulonii var. vulnera var. nov.: Three Multiresistant Human Pathogenic Yeasts

“…Final results were expressed as an average of three independent experiments Ϯ the standard deviation (SD) where biofilms of each strain tested were cultivated in four parallel wells. The presence of biofilms was evaluated according to the Co value calculated from the average optical density at 600 nm (OD 600 ) of the three measurements of the negative control plus 3 times the SD as suggested by Holá et al (14). Biofilm formation by each isolate was scored as negative (OD 600 ϭ Ͻ0.…”

The Formation of Poly-Microbial Biofilms on Urinary Catheters

“…The best way for isolation of wide spectrum of pathogens from urinary catheter biofilm, the sonication seems to be most appropriate method (Hola et al, 2010). The catheter must be aseptically withdrawn into empty sterile test tube and sent immediately for microbial examination.…”

“…Due to number of microbial species and their different growing speed, the immediate examination is of particular interest. Otherwise the results can be distorted by overgrowing of some fast-growing species (Hola et al, 2010).…”

“…The suspension is subsequently diluted 10-and 100-times and inoculated to solid media. This step is necessary for accurate quantification and isolation of individual strains (Hola et al, 2010). The set of solid media used in our laboratory comprises of Blood Agar, UriSelect 4 (BioRad), Endo Agar, Blood Agar with 10% of NaCl, Blood Agar with Amikacine (32mg/1L) and Sabouraud Agar with Vankomycine (5mg/1L) and Amikacine (20mg/1L).…”

Culture-Dependent and -Independent Investigations of Microbial Diversity on Urinary Catheters

“…Antibiotic usage, inappropriate culture conditions, and viable but nonculturable bacteria may also cause false-negative culture (51). To improve the recovery of the biofilm attached to the catheters, swabbing (32) and sonication (20) of the catheter have been used, and greater sensitivity was achieved by both approaches. In addition, pathogens can gain access to catheters extra-or intraluminally (42), and the microbial population on the two sides of the catheter can be different (15); hence, analyzing one side of the catheter or the catheter tip alone may be insufficient to detect all of the microbes on the catheter.…”