Clinical and Molecular Epidemiology of Multidrug-Resistant P. aeruginosa Carrying aac(6')-Ib-cr, qnrS1 and blaSPM Genes in Brazil

Abstract

We described a comprehensive analysis of the molecular epidemiology of multidrug-resistant (MDR) P. aeruginosa. Molecular analysis included typing by Pulsed Field Gel Electrophoresis, identification of genes of interest through PCR-based assays and sequencing of target genes. Case-control study was conducted to better understand the prognostic of patients and the impact of inappropriate therapy in patients with bacteremia, as well as the risk factors of MDR infections. We observed a high rate of MDR isolates (40.7%), and 51.0% of them was independently associated with inappropriate antibiotic therapy. Bacteremia was detected in 66.9% of patients, and prolonged hospital stay was expressive in those resistant to fluoroquinolone. Plasmid-mediated quinolone resistance genes (PMQR), qnrS1 and aac(6’)Ib-cr, were detected in two different nosocomial isolates (5.3%), and the aac(6’)-Ib7 variant was detected at a high frequency (87.5%) in those negative to PMQR. The presence of mutations in gyrA and parC genes was observed in 100% and 85% of selected isolates, respectively. Isolates harboring PMQR genes or mutations in gyrA and parC were not closely related, except in those containing SPM (São Paulo metallo-β-lactamase) clone. In addition, there is no study published in Brazil to date reporting the presence of Pseudomonas aeruginosa isolates harboring both qnrS1 and aac(6’)Ib-cr genes, with alarming frequency of patients with inappropriate therapy.

Changes to the resistome of Pseudomonas aeruginosa clone ST308 associated with corneal infection over time

“…Strain 219 had also acquired the plasmid related fluoroquinolone resistance gene aac(6′)-Ib-cr [26] which can confer resistance to both fluoroquinolones and aminoglycosides [27]. Previously this gene was found responsible for the 16 to 128-fold higher MICs for ciprofloxacin in the transconjugants bacteria of family Enterobacteriaceae [28] and MIC of 64 µg/ml of ciprofloxacin to MDR P. aeruginosa isolates [29]. These additional resistance imposing elements to fluoroquinolones suggest that alternative treatments for keratitis other than fluoroquinolone monotherapy should be considered.…”

Pseudomonas infections among hospitalized adults in Latin America: a systematic review and meta-analysis

“…The literature search identified a total of 165 citations; of which, 98 full-text articles were retrieved and assessed for eligibility. The systematic review included 19 articles (6 articles for AIAT versus IIAT [12][13][14][15][16][17]; 17 articles for acquisition of resistant or multidrug-resistant P. aeruginosa [12,[14][15][16][18][19][20][21][22][23][24][25][26][27][28][29][30] and 4 articles reported both outcomes [12,[14][15][16]) that met final eligibility criteria ( Fig. 1).…”

“…Seven eligible studies (published in six articles) included 885 hospitalized adults with P. aeruginosa infections. Included studies were conducted between 2005 and 2012 in Brazil (5 studies [12,14,15,17,31]) and Colombia (1 study). One study was retrospective cohort and five studies were casecontrol designs ( Table 2).…”

“…One study was retrospective cohort and five studies were casecontrol designs ( Table 2). The underlying site of infection was bloodstream infection (3 studies [12,15,31]), respiratory (2 studies [13,17]) and information was not reported in one study [14]. The average age of patients among included studies ranged between 50 and 73 years.…”

Carbapenem-resistant Pseudomonas aeruginosa bloodstream infection: in vitro synergy, virulence and clinical outcome

“…Five clones named as A, B, C, D and E harboured SPM and belonged to ST277 were found by PFGE during the study period (table 1). ST277 is common in Brazil and has been described in several outbreaks including patients who travelled to the country (13–16). Interestingly, the six strains that co-harbored KPC were distributed in four clones, except the predominant clone named as clone A.…”