Virulence factors and integrons are associated with MDR and XDR phenotypes in nosocomial strains of Pseudomonas aeruginosa in a Venezuelan university hospital

Abstract

Multidrug resistance (MDR), virulence and transferable elements potentiate Pseudomonas aeruginosa 's role as an opportunistic pathogen creating a high risk for public health. In this study, we evaluated the possible association of multidrug resistance, virulence factors and integrons with intrahospital P. aeruginosa strains isolated from patients at Cumana hospital, Venezuela. Relevant clinical-epidemiological data were collected to study 176 strains (2009-2016) isolated from different hospital units. Bacterial resistance was classified as susceptible, low-level resistant (LDR), multidrug resistant (MDR) and extensively drug-resistant (XDR). Most strains produced pyoverdine, DNase, gelatinase and hemolysin. Around 73% of the strains showed some type of movement. MDR and XDR strains increased from 2009 (24.2% and 4.8%, respectively) to 2016 (53.1% and 18.8%); while LDR decreased from 64.5% to 6.3%. The exo U and exo S genes were found in a significant number of strains (38.1 and 7.4%, respectively). Class I integrons were detected in 35.8% of the strains and the frequency was associated with resistance (42.9, 22.4, 41.4 and 61.9%, for susceptible, LDR, MDR and XDR, respectively). The MDR/XDR strains were positively associated with hemolysins and exo U, but negatively associated with bacterial twitching. MDR/XDR phenotypes were also associated with the Intensive Care Unit (ICU), septicemia, bronchial infection and diabetic foot ulcers, as well as long hospital stay (≥10 days) and previous antimicrobial treatment. High frequency of MDR/XDR strains and their association with class I integrons and virulence factors can increase the infection potential, as well as morbidity and mortality of patients attending this hospital and could spread infection to the community, creating a health risk for the region.

<p>Virulence Factors Of Carbapenem-Resistant <em>Pseudomonas aeruginosa</em> In Hospital-Acquired Infections In Mansoura, Egypt</p>

“…Additionally, many authors described a significant positive correlation between MBL and AmpC β-lactamase production and biofilm formation 35. In contrast to our results, other studies found no significant difference in the association of biofilm formation and the presence of multidrug resistance 22,36. Also, no statistical significance was found between MBL and biofilm formation 31…”

“…The same finding was previously reported 23,29. This high rate of imipenem resistance may be due to uncontrolled carbapenem use in hospital infections 22. Carbapenem resistance among P. aeruginosa isolates is attributed mainly to carbapenemase production 5.…”

“…Furthermore, more than half of these MDR and XDR isolates were carbapenem resistant. A similar rate was reported in Venezuela in which MDR and XDR P. aeruginosa increased to 71.9% in 2016 22. Also, Rossi Goncalves23 concluded a high rate of MDR (73.9%).…”

<p>Virulence Constitution of Multi-Drug-Resistant <em>Pseudomonas aeruginosa</em> in Upper Egypt</p>

“…30 We found a high frequency of exoU in our isolates indicating that more than half of the isolates display the cytotoxic phenotype, 31 which is associated with more pulmonary damage than invasive phenotypes. 32 This finding is consistent with Rodulfo et al, 33 who found a high frequency of exoU in MDR P. aeruginosa isolates. On the other hand, exoS was detected in a relatively similar frequency as exoU; with 17 isolates (43%) harboring exoS gene alone and 3 isolates possessing both genes (7.6%).…”

It’s Not Easy Being Green: A Narrative Review on the Microbiology, Virulence and Therapeutic Prospects of Multidrug-Resistant Pseudomonas aeruginosa

“…In addition to the presence of Car-R/Ceph-S isolates (reported to be~13% of the overall pool of isolates), their report highlighted the continuous increase in resistance rates to β-lactam antibiotics and class I integrons between 2009 and 2016 (37.1% vs. 50.0% for piperacillin-tazobactam, 32.3% vs. 50% for ceftazidime, 33.9% vs. 50% for cefepime, 38.7% vs. 65.6% for imipenem, and 37.1% vs. 59.4% for meropenem). They have also found a positive association between the MDR/XDR phenotype and the presence of hemolysin, the exoU gene, and integrase I [243]. In the study of Khan et al, the resistance characteristics of keratitis-causing P. aeruginosa isolates, originating from Australia and India, were compared [73].…”