However, in their study only 11 bacterial clones from 3 different IC patients were analyzed and the bacterial sequences

were related to E.coli, Abiotrophia defectivus, Veillonella and Rothia dentocariosa. Except for Veillonella, these PND-1186 price bacteria were not detected in our study. All these 4 previously reported studies used different primer sets (likely to explain some of the differences in the results) and classical cloning strategies (explaining the very few sequences analyzed). In contrast, our study represents the first 16S rDNA amplicon high throughput sequencing approach on IC urine, increasing both the AZD0530 sensitivity and resolution of the investigation. Significance of Lactobacillus in IC urine Lactobacillus has not Tanespimycin only been indicated or shown in IC urine samples from females (100% of the cases in this study and as shown by others [6, 9, 39]) but also demonstrated in IC urine from a male subject [41]. In our study we also detected a significant increase in abundance

of this genus, considering its supposedly commensal presence in human urine from healthy subjects [16, 18, 19]. Lactobacillus is generally considered to be of low virulence, rarely causing infections in humans. It is best known for its presence in vaginal microflora, where it normally generates and maintains a physiological acidic environment, which prevents infections.

Because of these properties, Lactobacillus has been used in probiotics, and is thought to prevent or even treat urinary tract infection (UTI) [42]. However, there are increasing indications that specific Lactobacillus spp are of pathogenic relevance and may be involved in urinary tract infections [43, 44]. Many female patients with symptoms suggestive of UTI, but with culture-negative urines are often treated with antibacterial agents since their symptoms may be indistinguishable from those with a proven UTI [45]. It has been proposed that Lactobacillus, resistant to widely used antibiotics, may multiply during treatment, giving the genus an advantage over antibiotic-sensitive commensals, and allowing it to invade the proximal urethra why and paraurethral tissues causing inflammatory changes [45]. This organism has also been related to the presence of UTI symptoms in otherwise culture-negative urines [43, 44, 46]. In a study by Maskell et al. (1983) [46] antibacterial treatment was withheld over the course of 2 years from symptomatic women with culture-negative urine. During the course of the study Lactobacilli (detected by special culture techniques) gradually disappeared from the urine of most of the patients who also became symptom free. A similar association of Lactobacillus and urinary symptoms was reported by Darbro et al. (2009) [44].