Multi-drug resistant strains as etiological agents of urinary tract infections in patients after solid organ transplantation.

Introduction: Urinary tract infections (UTIs) caused by multi-drug resistant strains are a serious and growing problem in organ transplant (TX) recipients.

Aim of the study: The aim of the study was to assess the prevalence and risk factors of UTIs caused by multi-drug resistant strains in hospitalized patients after kidney or liver transplantation in a large transplant center.

Material and methods: 392 cases of UTIs in patients after kidney or liver TX hospitalized in 2014, 2015 and 2016 were analyzed. Among the assessed cases of UTIs, 66.07% occurred in women, 33.93% - in men, 80.1% - in kidney TX recipients and 19.9% - in liver TX recipients. The median age of the patients was 57.51 years and the median time since TX was 41.44 months.

Results: Most episodes of UTIs were observed during the first year after TX - 121 (30.78%) of cases. A total of 506 pathogens were cultured: 345 Gram-negative bacteria (68.182%), 146 Gram-positive bacteria (28.854%) and 15 fungi (2.964%). More than one pathogen was found in 25.51% of urine cultures. Among bacteria (n=491), a resistance mechanism was detected in 166 (33.81%) pathogens (133 Gram-negative and 33 Gram-positive). The most common etiological agents were: E. coli ESBL- (23.72%), K. pneumoniae ESBL+ (17.19%), E. faecalis (11.27%) and E. faecium (7.71%). Diabetes was present in 129 (35.46%) of patients, and the number of UTI cases was similar in the group with and without diabetes.

Conclusions: Compared to the general population, in hospitalized patients after kidney or liver transplantation UTIs occur more often in men and are more often caused by Gram-positive bacteria. In 33.81% of cases UTIs are caused by multi-drug resistant strains, predominantly Gram-negative bacteria.