Clinical outcomes, molecular epidemiology and resistance mechanisms of multidrug-resistant <i>Pseudomonas aeruginosa</i> isolated from bloodstream infections from Qatar
Creators: name: Ahmed, Mazen A. Sid
name: Hamid, Jemal M.
name: Husain, Ahmed A.
name: Hadi, Hamad Abdel
name: Skariah, Sini
name: Sultan, Ali A.
name: Ibrahim, Emad Bashir
name: Al Khal, Abdul Latif
name: Soderquist, Bo
name: Jass, Jana
name: Omrani, Ali S.
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Genetics
subject: Environmental Sciences not elsewhere classified
subject: Immunology
subject: FOS: Clinical medicine
subject: Biological Sciences not elsewhere classified
subject: Cancer
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology
subject: Computational Biology

description: Bloodstream infections (BSIs) caused by multidrug-resistant (MDR)-<i>Pseudomonas aeruginosa</i> are associated with poor clinical outcomes, at least partly due to delayed appropriate antimicrobial therapy. The characteristics of MDR-<i>P. aeruginosa</i> bloodstream isolates have not been evaluated in Qatar. Our study aimed to examine <i>in vitro</i> susceptibility, clinical and molecular characteristics, and mechanisms of resistance of MDR-<i>P. aeruginosa</i> bloodstream isolates from Qatar. We included all MDR-<i>P. aeruginosa</i> isolated from blood cultures taken between October 2014 and September 2017. Blood cultures were processed using BD BACTEC™ FX automated system. BD Phoenix™ was used for identification, Liofilchem® MIC Test Strips for MIC determination. Whole-genome sequencing was performed using the Illumina-HiSeq-2000. Out of 362 <i>P. aeruginosa</i> bloodstream isolates, 16 (4.4%) were MDR. The median patient age was 55 years (range 43–81) and all patients presented with septic shock. Most patients received meropenem (12/16) and/or colistin (10/16). Clinical response was achieved in eight patients, and five patients died within 30-days. MDR-<i>P. aeruginosa</i> isolates belonged to 13 different sequence types. All isolates were non-susceptible to cefepime and ciprofloxacin. The most active agents were colistin (16/16) and aztreonam (10/16). Seven isolates produced <i>bla</i><sub>VIM,</sub> and four possessed genes encoding extended-spectrum β-lactamases. Aminoglycoside modifying enzymes were present in 15/16, transferable <i>qnr</i>-mediated quinolone resistance gene was detected in 3/16, and the novel ciprofloxacin modifying enzyme <i>CrpP</i>-encoding gene in one isolate. MDR-<i>P. aeruginosa</i> BSIs are relatively uncommon in Qatar but are highly resistant, harbour multiple resistance genes, and are commonly associated with unfavourable clinical outcomes. Colistin was the only agent with consistent activity against the study isolates.Key messagesMDR-<i>P. aeruginosa</i> constituted &lt;5% of <i>P. aeruginosa</i> blood isolates over three years.Typical risk factors for MDR infections were highly prevalent in the study population and overall clinical outcomes are consistent with those previously reported.Colistin was the only agent with consistent antibacterial activity against the study isolates. MDR-<i>P. aeruginosa</i> constituted &lt;5% of <i>P. aeruginosa</i> blood isolates over three years. Typical risk factors for MDR infections were highly prevalent in the study population and overall clinical outcomes are consistent with those previously reported. Colistin was the only agent with consistent antibacterial activity against the study isolates.