Performance of two methods of carbapenem-resistant Enterobacterales surveillance on a kidney transplant ward: selective culture of and real-time PCR directly from rectal swabs

Infection. 2022 Dec;50(6):1525-1533. doi: 10.1007/s15010-022-01839-2. Epub 2022 May 9.

Abstract

Background: Infection with carbapenem-resistant Enterobacterales (CRE) is associated with a high mortality rate in kidney transplant recipients, and colonization with CRE is one of the major risk factors for CRE infection. There is, therefore, a need to improve the capacity to detect colonization with CRE among inpatients.

Methods: In this prospective study, we compared the performance of real-time PCR for carbapenemase directly from rectal swabs with that of conventional CRE surveillance culture in all patients admitted to a kidney transplant ward between February 2019 and March 2020. Surveillance culture and real-time PCR were performed at admission and weekly until hospital discharge. Two perineum-rectal swabs were collected: one for culture and one for PCR.

Results: We collected 905 paired samples for CRE surveillance from 399 patients, of whom 347 (87.0%) were kidney transplant recipients and 52 were waiting list patients. CRE was detected by culture and/or PCR in 75 patients (18.8%). Positivity for CRE was identified by PCR in 62 (15.5%) of the 399 patients and by culture in 55 (13.8%); 20 (5.0%) of the patients tested positive only on PCR, and 13 (3.3%) tested positive only on culture. The most common carbapenemase and species were, respectively, blaKPC (in 85.5%) and Klebsiella pneumoniae (in 80.0%). Infection with CRE occurred in 21.6% of the colonized patients, those cases occurred only among kidney transplant recipients. None of the patients who tested negative on culture developed CRE infection.

Conclusion: In conclusion, the two methods are complementary and could be useful in a scenario of high CRE prevalence.

Keywords: Carbapenem resistance; Carbapenemase; Kidney transplant; Real time PCR; Risk factors; Surveillance.

MeSH terms

  • Anti-Bacterial Agents / therapeutic use
  • Carbapenem-Resistant Enterobacteriaceae* / genetics
  • Carbapenems / pharmacology
  • Enterobacteriaceae Infections* / diagnosis
  • Enterobacteriaceae Infections* / drug therapy
  • Enterobacteriaceae Infections* / epidemiology
  • Hospitals
  • Humans
  • Kidney Transplantation* / adverse effects
  • Prospective Studies
  • Real-Time Polymerase Chain Reaction

Substances

  • Carbapenems
  • Anti-Bacterial Agents