Whole genome sequencing of resistance and virulence genes in multi-drug resistant Pseudomonas aeruginosa.

BACKGROUND: Pseudomonas aeruginosa is an opportunistic bacterium that causes serious hospital-acquired infections. To assess the risk of clinically isolated P. aeruginosa to human health, we analyzed the resistance and virulence mechanisms of a collection of clinical isolates. METHODS: This was a retrospective study in which P. aeruginosa isolates collected from January 1, 2018 to August 31, 2019 were analyzed using phenotypic and whole-genome sequencing (WGS) methods. The analysis included 48 clinical samples. Median patient age was 54.0 (29.5) years, and 58.3% of patients were women. Data from the microbiology laboratory database were reviewed to identify P. aeruginosa isolates. All unique isolates available for further testing were included, and related clinical data were collected. Infections were defined as hospital acquired if the index culture was obtained at least 48 h after hospitalization. RESULTS: High-risk P. aeruginosa clones, including sequence types (STs) ST235 and ST111, were identified, in addition to 12 new STs. The isolates showed varying degrees of biofilm formation ability when evaluated at room temperature, along with reduced metabolic activity, as measured by metabolic staining, suggesting their ability to evade antimicrobial therapy. Most isolates (77.1%) were multidrug resistant (MDR), with the highest resistance and susceptibility rates to beta-lactams and colistimethate sodium, respectively. CONCLUSIONS: The MDR phenotypes of the examined isolates can be explained by the high prevalence of efflux-mediated resistance- and hydrolytic enzyme-encoding genes. These isolates had high cytotoxic potential, as indicated by the detection of toxin production-related genes.

A prospective cohort study comparing achieved anti-factor Xa peak levels in pregnant and non-pregnant patients receiving therapeutic-dose low-molecular-weight heparin.

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in pregnant women. Enoxaparin is a low-molecular-weight heparin used during pregnancy to treat or prevent VTE. In this study, we compare anti-factor Xa peak levels in pregnant and non-pregnant women, and explore the association between anti-factor Xa (AFXa) peak levels and possible predictive parameters. Pregnant and non-pregnant patients received a therapeutic dose of enoxaparin every 12 h and three steady-state AFXa peak levels at 4-week intervals were collected. Sixty-eight patients (36 pregnant and 32 non-pregnant women) were enrolled. AFXa peak levels within therapeutic range (0.6-1.0 IU/ml) were achieved in the first measurement in 14 (38.9%) pregnant women compared to 21 (65.6%) non-pregnant women (p = 0.028). In the second anti-factor Xa measurement, 20 (55.6%) compared to 25 (78.1%) were within the reference interval (p = 0.008). Similar results were seen with the third measurement 20 (55.6%) compared to 26 (81.3%) (p = 0.003). In a mixed-effect repeated-measures model, pregnancy was associated with AFXa peak level (Mean difference = - 0.177; 95% CI - 0.349 to - 0.005, p = 0.044). These findings suggest that further evaluation of a strategy involving more frequent monitoring of achieved AFXa levels could result in more effective anticoagulation.