Uropathogen profiles and their antimicrobial resistance patterns in patients: a three-year retrospective study in...

Urinary tract infection (UTI) is the most common infection requiring empiric antibiotic treatment. Due to the increased antibiotic resistance of uropathogens and their regional variation, monitoring pathogen distribution and antimicrobial susceptibility is important to ensure effective antibiotic therapy. This retrospective study analyzed the 3-year-long uropathogen profiles and their resistance from a single tertiary general hospital (single-center) and 28 hospitals (multi-center) to provide data allowing guidance for appropriate empiric antimicrobial treatment for UTI.

A total of 26,108 non-repetitive clinical urine isolates from the single-center during 2017-2019 and the multi-center in 2018 were collected, the pathogen and antimicrobial resistance profiles were analyzed.

Escherichia coli, Enterococcus faecium, Klebsiella pneumoniae, Enterococcus faecalis, and Pseudomonas aeruginosa were the top five bacterial pathogens for both the multi-center and single-center, while the proportion of Candida albicans was higher in the single-center. E. coli was the most resistant species, with resistance rates exceeding 50% for 13/30 of the antibiotics tested, even exceeding 80% for ampicillin, nalidixic acid and piperacillin. Particularly, the resistance rates of E. coli to cefazolin were 62.7% in the multi-center while exceeding 90% in the single-center. Similarly, the resistance rates of K. pneumoniae were approximately 40% ~ 60% to 16/29 of the antibiotics tested in the single-center, compared to 30% ~ 50% in the multi-center. In enterococci, E. faecium showed the resistance rates exceeding 90% for 6/10 of the antibiotics tested, while E. faecalis was highly resistant to erythromycin (> 66%) and tetracycline (> 81%). The main fungal pathogens were C. albicans, Candida tropicalis, and Candida glabrata, with the highest resistance rates exceeding 30% for C. tropicalis to fluconazole, itraconazole and voriconazole. The main extended-spectrum beta lactamase (ESBL)-producing isolates were E. coli (86.3%) and K. pneumoniae (11.3%), with resistance rates exceeding 60% for cephalosporins, sulfonamides, quinolones and tetracycline in the single-center.

Escherichia coli, E. faecium, K. pneumoniae, E. faecalis, P. aeruginosa and C. albicans were the main uropathogens in the southwestern region of China, while E. coli and E. faecium showed the highest antibiotic resistance. The high resistance of ESBL-producing isolates to cephalosporins, sulfonamides, quinolones and tetracycline in the tertiary general hospital suggests a greater challenge to their antibiotic administration and timely ESBL test, and the empirical antimicrobial therapy should greatly consider the updated local characteristics of the uropathogen resistance, and be more cautious in the tertiary general hospital where patients are more likely to harbor higher resistant pathogens.