A model of catheter‐associated urinary tract infection initiated by bacterial contamination of the catheter tip

Abstract

extracted from selected patient catheter isolates and the DNA fragment of 16S ribosomal RNA was amplified by polymerase chain reaction and confirmed by DNA sequencing. The DNA sequences from the isolates obtained from different catheter sections and from urine in the same patient were compared. RESULTSAfter 1 day of catheterization there was significant bacterial growth on the outside of all the segments of patient catheters; there was significant growth on the inside of all segments by 4 days. Higher viable counts and a wider spectrum of genera were found on the outside than on the inside of these catheters. The same strains of bacteria, as determined by ≥ 98% similarity of the 16S ribosomal DNA sequence, were found on the outside and inside of catheters and in the urine. In the in vitro model, when the distal urethra was inoculated before inserting the catheter, the viable counts after incubation were variable along the outside of the catheter and the inside counts were uniformly high. By contrast, there was a different pattern after inoculating the inside of the distal end of the catheter, leading to an ascending biofilm on the inside. A smaller inoculum delayed but did not prevent infection in the model. CONCLUSIONThe present results are consistent with the hypothesis that contamination of the tip of the catheter while it is being inserted is a possible means by which bacteria gain access to the bladder.

Culture-Independent Microbiological Analysis of Foley Urinary Catheter Biofilms

“…At the species level, the most abundant phylotypes were representative of microorganisms that colonize and/or infect humans, including Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus epidermidis, Streptococcus pneumoniae , Escherichia coli, Enterococcus faecalis, and Propionibacterium acnes. A recent, culture-dependent analysis of catheter biofilms also reported the identification of similar microorganisms, including Staphylococcus epidermidis, Enterococcus faecalis, Pseudomonas spp, and Klebsiella spp [15]. Many taxa were identified in multiple catheters (prevalences ranged from 13%–63%).…”

“…Diverse microbial species have been identified from catheter biofilms by microbiological culture [5], [13], [14], [15]. However, Nickel et al [10] reported that although multiple morphological types were observed to colonize Foley urinary catheters, only a small fraction of the attendant microorganisms could be detected by traditional microbiological culture.…”

“…Barford et. al., [15]), we have used rRNA-based molecular-phylogenetic methods that do not require prior culture [16], [17] to comprehensively survey the types of microorganisms that colonize Foley urinary catheters.…”

Rethinking Suprapubic Cystostomy in Voiding Dysfunction: New Trial with Timed Drainage

“…Since the introduction of closed drainage systems, the incidence of catheter-associated UTI via ascending routes has been reduced. Barford et al reported in an experimental model that most bacteria gain access to the bladder along the outside of the catheter [16]. However, their study included data from a short period of up to 5 days.…”

Resistencia bacteriana de cultivos de orina en un hospital oncológico:seguimiento a diez años

“…1 Las IVU pueden complicarse con bacteriemia y sepsis, lo cual incrementa la morbimortalidad, los días de estancia hospitalaria y los costos relacionados. 2 En la última década se identificó un incremento en las cepas bacterianas resistentes en orina, tanto de pacientes de la comunidad como de pacientes hospitalizados. 3 Los pacientes con cáncer tienen mayor riesgo de infecciones debido a la inmunosupresión condicionada por la enfermedad per se, así como por el tratamiento, además de que algunos pacientes pueden presentar obstrucción anatómica del tracto urinario secundaria al tumor.…”