Comparison of the clinical characteristics of community-acquired acute pyelonephritis between male and female patients

Clinical and microbiological characteristics of female patients with acute pyelonephritis who experienced urinary tract infections within the previous year

BACKGROUND

This study aimed to examine the clinical and microbiological characteristics of female patients with recurrent acute pyelonephritis (APN).

METHODS

A retrospective cohort study was conducted at a tertiary care hospital in South Korea from July 2019 to December 2021. All female patients aged ≥ 19 years who were diagnosed with community-acquired APN on admission were enrolled. The recurrent group included patients with APN who experienced urinary tract infections within the previous year. The clinical characteristics, types of causative organisms, major antibiotic resistance, and molecular characteristics of Escherichia coli strains were compared between the recurrent and non-recurrent groups.

RESULTS

A total of 285 patients with APN were analyzed, including 41 (14.4%) in the recurrent group. Compared to the non-recurrent group, the recurrent group had a higher Charlson Comorbidity Index (1.8 ± 2.1 vs. 1.1 ± 1.5; P = 0.01) and a higher proportion of bladder abnormalities, such as neurogenic bladder (12.2% vs. 2.0%; P = 0.001) and urinary catheterization (12.2% vs. 1.6%; P < 0.001). Escherichia coli was the most common causative organism in both groups. The proportion of Klebsiella pneumoniae (17.1% vs. 4.7%; P = 0.007) and Pseudomonas aeruginosa (5.7% vs. 0.5%; P = 0.014) as a causative organism was higher in the recurrent group. Regarding the microbiological characteristics of Escherichia coli, there were no significant differences in the proportion of antibiotic resistance, phylogenetic groups, resistance genes, and virulence factors between the two groups. Multivariable analysis showed that neurogenic bladder and a history of admission or antibiotic use during 1 year prior to inclusion were significantly associated with recurrent APN.

CONCLUSIONS

The proportion of causative organisms except Escherichia coli was higher in the recurrent group than in the non-recurrent group. Neurogenic bladder and a history of admission or antibiotic use during 1 year prior to inclusion were risk factors for recurrent APN.

Comparison of the Clinical and Genotypic Characteristics of Uropathogenic Escherichia coli Strains According to Sex in Korea

In this study, we compared the microbiological, genotypic, and antibiotic resistance characteristics of uropathogenic Escherichia coli (UPEC) strains in patients with pyelonephritis in Korea according to sex based on data corresponding to the February 2015 to June 2018 period. Based on Escherichia coli phylogenetic group analysis, gene virulence detection, and subgroup analyses by sex, we observed that the antibiotic resistance percentages and proportions corresponding to extended-spectrum beta-lactamase producing UPEC were higher in males than in females. In addition, phylogenetic group B2 showed predominance in both the male and female groups, which further showed similar adhesion molecule distributions. Toxin-associated factors, hlyA and cnf1, were more common in males. In clinical presentations, urinary predisposing factors, complicated urinary tract infections (UTIs), concomitant bacteremia, and persistent fever were also more common with males. Although females and males showed UPEC genotypic differences, there were no differences between them with respect to poor outcomes. Persistent fever was associated with community-acquired infection and bacteremic UTI and relapsed UTI within 3 months was associated with urinary tract stone. In future, it will be necessary to conduct multicenter studies, involving more cases on UPEC to validate our results.