Molecular characterization of multidrug resistant Enterobacterales strains isolated from liver and kidney transplant recipients in Spain

The objective of this study was to analyse the mechanisms of resistance to carbapenems and other extended-spectrum-beta-lactams and to determine the genetic relatedness of multidrug-resistant Enterobacterales (MDR-E) causing colonization or infection in solid-organ transplantation (SOT) recipients. Prospective cohort study in kidney (n = 142), liver (n = 98) or kidney/pancreas (n = 7) transplant recipients between 2014 and 2018 in seven Spanish hospitals. We included 531 MDR-E isolates from rectal swabs obtained before transplantation and weekly for 4-6 weeks after the procedure and 10 MDR-E from clinical samples related to an infection. Overall, 46.2% Escherichia coli, 35.3% Klebsiella pneumoniae, 6.5% Enterobacter cloacae, 6.3% Citrobacter freundii and 5.7% other species were isolated. The number of patients with MDR-E colonization post-transplantation (176; 71.3%) was 2.5-fold the number of patients colonized pre-transplantation (71; 28.7%). Extended-spectrum beta-lactamases (ESBLs) and carbapenemases were detected in 78.0% and 21.1% of MDR-E isolates respectively. In nine of the 247 (3.6%) transplant patients, the microorganism causing an infection was the same strain previously cultured from surveillance rectal swabs. In our study we have observed a low rate of MDR-E infection in colonized patients 4-6 weeks post-transplantation. E. coli producing bla(CTX-M-G1) and K. pneumoniae harbouring bla(OXA-48) alone or with bla(CTX-M-G1) were the most prevalent MDR-E colonization strains in SOT recipients.

Automated summary

The study aimed to analyze the mechanisms of resistance to carbapenems and other extended-spectrum-beta-lactams in solid-organ transplantation recipients, and to determine the genetic relatedness of multidrug-resistant Enterobacterales (MDR-E) causing colonization or infection. The findings showed that the number of patients colonized by MDR-E post-transplantation was significantly higher than pre-transplantation, with the presence of extended-spectrum beta-lactamases (ESBLs) and carbapenemases. The study observed a low rate of MDR-E infection in colonized patients 4-6 weeks post-transplantation.