Open AccessBiofilm formation in trimethoprim/sulfamethoxazole-susceptible and trimethoprim/sulfamethoxazole-resistant uropathogenic Escherichia coli
Author(s) -
Nitis Smanthong,
Ratree Tavichakorntrakool,
Phitsamai Saisud,
Vitoon Prasongwatana,
Pipat Sribenjalux,
Aroonlug Lulitad,
Orathai Tunkamnerdthai,
Chaisiri Wongkham,
Patcharee Boonsiri
Publication year - 2015
Publication title -
asian pacific journal of tropical biomedicine/asian pacific journal of tropical biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 61
eISSN - 2588-9222
pISSN - 2221-1691
DOI - 10.1016/j.apjtb.2015.03.006
Subject(s) - sulfamethoxazole , microbiology and biotechnology , biofilm , escherichia coli , trimethoprim , biology , bacterial growth , bacterial cell structure , bacteria , incubation , antibiotics , biochemistry , genetics , gene
ObjectiveTo 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.MethodsA 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 electron microscope 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.ResultsThe 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) μm, P < 0.05)], whereas the bacterial colony size and mid-log phase of the growth curve were not significantly different.ConclusionsThe present study indicated that biofilm formation and phenotypic change of uropathogenic E. coli can be attributed to the mechanism of E. coli SXT resistance