Abstract
The presence of adhesins is arguably an important determinant of pathogenicity for Uropathogenic Escherichia coli (UPEC). Antimicrobial susceptibilities were tested by agar dilution method, fifteen adhesin genes were detected by polymerase chain reaction, and multilocus sequence typing (MLST) was analyzed in 70 UPEC isolates and 41 commensal E. coli strains. Extended-spectrum β-lactamase (ESBL) was determined with confirmatory test. The prevalence of ESBL-producers in UPEC (53%, 37/70) was higher than the commensal intestinal isolates (7%, 3/41), and 97% (36/37) of the ESBL-producing UPEC harbored bla CTX-M genes. afa was present in 36% (10/28) UPEC isolates from recurrent lower urinary tract infection (UTI), and none in the acute pyelonephritis, acute uncomplicated cystitis or commensal strains (P<0.0001). papG was detected in 28% (20/70) of UPEC isolates, while 5% (2/41) of the commensal strains were papG positive (P = 0.0025), and the prevalence of papG was significantly higher in acute pyelonephritis group (71%) than the other two UTI groups (P<0.0001). The prevalence of flu, yqi, yadN and ygiL was significantly higher in UPEC isolates than in the commensal strains. ESBL-producing UPEC showed a lower prevalence of adhesin genes compared with non-ESBL-producing strains. The MLST profiles were different between UPEC and commensal strains, with ST131 (19%, 13/70) and ST10 (20%, 8/41) being the most common MLSTs, respectively. This study demonstrated that several adhesin genes were more prevalent in UPEC isolates than in commensal E. coli, and afa may be associated with recurrent lower UTI whereas papG is more frequently associated with acute pyelonephritis.
Highlights
Urinary tract infection (UTI) is one of the most common bacterial infections, and it is estimated that the overall lifetime prevalence of UTI in women is greater than 50% [1]
Thirty-seven (53%) of 70 Uropathogenic Escherichia coli (UPEC) isolates, while 3 (7%) out of 41 intestinal commensal isolates were Extended-spectrum b-lactamase (ESBL)-producing (P,0.001). blaCTX-M genes were present in 97% (36/37) ESBL-producing isolates, and of these, 58% (21/36) carried blaCTX-M-1-group ESBL genes while 42% (15/36) belonged to blaCTX-M-9-group
Prevalence of adhesin genes (1) Afa/Dr adhesin family member genes. afa was present only in 10 UPEC isolates that belonged to the recurrent lower UTIs group (10/28, 36%)
Summary
Urinary tract infection (UTI) is one of the most common bacterial infections, and it is estimated that the overall lifetime prevalence of UTI in women is greater than 50% [1]. Uropathogenic Escherichia coli (UPEC) is the causative pathogen in 70–95% community-acquired UTI and over 50% nosocomial UTI [3]. The presence of adhesins is arguably the most important determinant of the pathogenicity for UPEC [4]. Adhesive organelles, including type 1, P, S/F1C, M, G and curli fimbriae, along with Afa/Dr adhesins, as well as temperature sensitive haemagglutinin (TSH), promote both bacterial attachment to and invasion of host tissues within the urinary tract [4,5,6]
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