ABSTRACT
Objective: To compare biofilm formation in trimethoprim/sulfamethoxazole (SXT)- susceptible Escherichia coli (E. coli) (SSEC) and SXT-resistant E. coli (SREC) isolated from patients with urinary tract infections, and study the motile ability and physical characteristics of the isolates. Methods: A total of 74 E. coli isolates were tested for antimicrobial susceptibility with the disc diffusion assay. Based on the SXT-susceptibility test, the E. coli isolates were divided into SSEC (N = 30) and SREC(N = 44) groups. All E. coli isolates were examined for motile ability by using a motility test medium, and for checking biofilm formation a scanning electronmicroscope was used. Bacterial colony size was measured with a vernier caliper and bacterial cell length was measured under a light microscope. The bacterial growth rate was studied by plotting the cell growth (absorbance) versus the incubation time. Results: The frequencies of non-motility and biofilm formation in the SREC group were significantly higher than that in the SSEC group (P < 0.01). The SREC bacterial cell length was shorter than that in the SSEC group [(1.35 ± 0.05) vs. (1.53 ± 0.05) mm, P < 0.05)], whereas the bacterial colony size and mid-log phase of the growth curve were not significantly different. Conclusions: The present study indicated that biofilm formation and phenotypic change of uropathogenic E. coli can be attributed to the mechanism of E. coli SXT resistance.
ABSTRACT
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ABSTRACT
This study was aimed to observe the effects of an oxalate-rich vegetable, Cha Plu (Paper sarmentosum), on risk of urinary stone formation. Sixty rats were used as experimental animal models and were divided into 3 equal groups. While group 1 was fed with normal food without the vegetable, group 2 and group 3 were fed with food containing 1% and 5% dry vegetable leaves, respectively. Twenty-four-hour urine specimens were collected and analyzed for calcium, oxalate, phosphate and creatinine. The analysis was carried out once every fortnight for 26 consecutive weeks. The rats were killed and urinary tract examination for the existence of stone was performed on the 26th week. The results showed that the patterns of growth, food and water intake, collected urine volume as well as urine composition among the 3 groups of rat were similar. In urinary tract exploration, a one-millimeter-size stone was found in renal pelvis of one rat in group 3 Chemical analysis, however, reealed that the stone was not the calcium stone type (calcium oxalate and/or calcium phosphate as the main components). If absorption processess are similar between the rats and the men, our results are not consistent with the propose that ingestion of oxalate-rich vegetable posts a high risk to urinary stone formation.