Background
Carbapenem -resistant
Pseudomonas aeruginosa (CRPA)
infection after
kidney transplantation (KT) is associated with high
mortality .
Methods We analysed an outbreak of
infection /colonization with
IMP -1-producing CRPA on a KT ward, conducting a
case-control study . Cases were identified through routine
surveillance culture and
real-time polymerase chain reaction (
PCR ) for carbapenemase performed directly from rectal swab samples. Controls were randomly selected from
patients hospitalized on the same ward during the same period, at a ratio of 31.
Strain clonality was analysed through
pulsed-field gel electrophoresis (PFGE), and whole-
genome sequencing was performed for additional
strain characterization. Results CRPA was identified in 37
patients , in 51.4% through
surveillance cultures and in 49.6% through clinical
cultures . The median persistence of
culture positivity was 42.5 days. Thirteen
patients (35.1%) presented a total of 15
infections , of which 7 (46.7%) were in the
urinary tract , among those, 30-day mortality rate was 46.2%. PFGE
analysis showed that all of the
strains shared the same pulsotype.
Multilocus sequence typing analysis identified the sequence type as ST446.
Risk factors for CRPA acquisition were
hospital stay > 10 days, re-
transplantation , urological surgical re-intervention after KT, use of
carbapenem or
ciprofloxacin in the last three months and low median
lymphocyte count in the last three months. Conclusions KT recipients remain colonised by CRPA for long periods and could be a source of nosocomial
outbreaks . In addition, a high proportion of such
patients develop
infection . During an outbreak,
urine culture should be added to the
screening protocol for KT recipients.