Evaluation of Reduced Susceptibility to Quaternary Ammonium Compounds and Bisbiguanides in Clinical Isolates and Laboratory-Generated Mutants of Staphylococcus aureus

The MICs and minimum bactericidal concentrations (MBCs) for the biocides benzalkonium chloride and chlorhexidine were determined against 1,602 clinical isolates of Staphylococcus aureus. Both compounds showed unimodal MIC and MBC distributions (2 and 4 or 8 mg/liter, respectively) with no apparent subpopulation with reduced susceptibility. To investigate further, all isolates were screened for qac genes, and 39 of these also had the promoter region of the NorA multidrug-resistant (MDR) efflux pump sequenced. The presence of qacA, qacB, qacC, and qacG genes increased the mode MIC, but not MBC, to benzalkonium chloride, while only qacA and qacB increased the chlorhexidine mode MIC. Isolates with a wild-type norA promoter or mutations in the norA promoter had similar biocide MIC distributions; notably, not all clinical isolates with norA mutations were resistant to fluoroquinolones. In vitro efflux mutants could be readily selected with ethidium bromide and acriflavine. Multiple passages were necessary to select mutants with biocides, but these mutants showed phenotypes comparable to those of mutants selected by dyes. All mutants showed changes in the promoter region of norA, but these were distinct from this region of the clinical isolates. Still, none of the in vitro mutants displayed fitness defects in a killing assay in Galleria mellonella larvae. In conclusion, our data provide an in-depth comparative overview on efflux in S. aureus mutants and clinical isolates, showing also that plasmid-encoded efflux pumps did not affect bactericidal activity of biocides. In addition, current in vitro tests appear not to be suitable for predicting levels of resistance that are clinically relevant.     

Longitudinal evaluation of mycophenolic acid pharmacokinetics in pediatric kidney transplant recipients. The role of post-transplant clinical and therapeutic variables

Abstract:  This longitudinal study assessed the influence of post-transplant clinical and therapeutic variables in 50 kidney transplant recipients aged 2–19 yr receiving a triple immunosuppressive regimen consisting of cyclosporine microemulsion (CsA), steroids and MMF (300–400 mg/m² body surface area twice daily), the full pharmacokinetic profile (10 points) of which was investigated on post-transplant days 6, 30, 180 and 360. Total plasma MPA was measured by Enzyme Multiplied Immunoassay Technique. CsA therapeutic drug monitoring (TDM) was performed via C2 blood monitoring, while MPA TDM via C0. MPA Cmax, tmax, AUC0-12 and AUC0-4 pharmacokinetic profile changed significantly during the first post-transplant year. C0 was a poor predictor of the total MPA exposure [as measured by the area under the concentration-time curve AUC)], while a truncated AUC was a good surrogate of the 12-h profile (r = 0.91; p < 0.001) Graft function and cyclosporine therapy influenced MPA pharmacokinetics, as shown by the univariate and multivariate analyses. We conclude that because after transplantation MPA exposure varied over time, a strict TDM is advisable in the pediatric population.     

Difficulties in the mutation analysis of plasminogen gene: a study in two patients with ligneous conjunctivitis.

The absence or very low levels of plasminogen cause a rare disabling disease called ligneous conjunctivitis, characterized by the growth of fibrin-rich pseudomembranes in the conjunctiva and on other mucosal surfaces. Several mutations have been detected in the plasminogen gene of patients affected with ligneous conjunctivitis. The human plasminogen gene, located on chromosome 6, has a marked homology with the genes belonging to the plasminogen-apo(a) family, and with a number of pseudogenes and plasminogen-like genes located on chromosome 2. This work describes a series of nucleotide variations related to genes other than the plasminogen one, found during the genetic characterization of plasminogen defect in two unrelated patients with ligneous conjunctivitis. The results of automated sequences of each exon and intron-exon boundaries were compared with those of the human plasminogen gene from the NCBI gene bank. In particular, a co-amplified gene on chromosome 2 mimicking a 14 bp deletion in exon 5 of the plasminogen gene was identified by sequencing two different bands obtained from a long run of the PCR exon 5 product in NuSieve agarose gel, and by PstI restriction enzyme analysis of the same amplicons. Moreover, 21 single nucleotide exchanges due to plasminogen-like genes co-amplification were observed, namely one in exon 1, two in exon 4, three in exons 3, 5 and 16, four in exon 13, and five in exon 17. In conclusion, these data confirm the difficulty of plasminogen genetic analysis and may help researchers to better identify the true plasminogen gene mutations causing molecular defects.     

Pre-Menopausal Breast Fat Density Might Predict MACE During 10 Years of Follow-Up: The BRECARD Study

ObjectivesThis study sought to determine whether the breast gland adipose tissue is associated with different rates of major adverse cardiac events (MACEs) in pre-menopausal women.BackgroundTo our knowledge, no study investigated the impact of breast adipose tissue infiltration on MACEs in pre-menopausal women.MethodsProspective multicenter cohort study conducted on pre-menopausal women >40 years of age without cardiovascular disease and breast cancer at enrollment. The study started in January 2000 and ended in January 2009, and the end of the follow-up for the evaluation of MACEs was in January 2019. Participants underwent mammography to evaluate breast density and were divided into 4 groups according to their breast density. The primary endpoint was the probability of a MACE at 10 years of follow-up in patients staged for different breast deposition/adipose tissue deposition.ResultsThe propensity score matching divided the baseline population of 16,763 pre-menopausal women, leaving 3,272 women according to the category of breast density from A to D. These women were assigned to 4 groups of the study according to baseline breast density. At 10 years of follow-up, we had 160 MACEs in group 1, 62 MACEs in group 2, 27 MACEs in group 3, and 16 MACEs in group 4. MACEs were predicted by the initial diagnosis of lowest breast density (hazard ratio: 3.483; 95% confidence interval: 1.476 to 8.257). Further randomized clinical trials are needed to translate the results of the present study into clinical practice. The loss of ex vivo breast density models to study the cellular/molecular pathways implied in MACE is another study limitation.ConclusionsAmong pre-menopausal women, a higher evidence of adipose tissue at the level of breast gland (lowest breast density, category A) versus higher breast density shows higher rates of MACEs. Therefore, the screening mammography could be proposed in overweight women to stage breast density and to predict MACEs. (Breast Density in Pre-menopausal Women Is Predictive of Cardiovascular Outcomes at 10 Years of Follow-Up [BRECARD]; NCT03779217)     

Numerical Activities of Daily Living – Financial: a short version

Neurological Sciences - Financial capacity is the ability to manage money and finances according to a person’s values and self-interests. In Italy, the first instrument specifically designed...     

Orbital volume and surface after Le Fort III advancement in syndromic craniosynostosis

There are no quantitative standards for the volumetric measurements of the orbital cavity after Le Fort III advancement. Computed tomography (CT) scan images have given the opportunity to compare with accuracy the real anatomic changes and potentially the functional improvements that resulted after a surgical treatment.Three-dimensional CT scan images processed by DICOM files in Dolphin 3D Software were used to assess orbital volume and surface in 12 subjects affected by craniofacial syndromic malformations treated with Le Fort III advancement. The preoperative (T0) and postoperative (T1: 6 months after surgery) three-dimensional craniofacial CT scans of the subjects were collected and retrospectively analyzed. Image segmentation of the anatomic orbital cavity and the three-dimensional graphic rendering were done by using the Dolphin Imaging Plus 11.0 software.The orbital volume was increased after surgery, with statistical significance, from 22,267 to 22,706.3 mm(3) in the right eye and from 26,511 mm(3) to 26,256.4 mm(3) in the left eye. The surface of both bony orbits had an expansion, which is statistically significant. In conclusion, this study showed that the orbital advancement in white subjects after Le Fort III advancement was significant and produced a significant augmentation of the orbital volume and surface area with correction of the ocular bulb proptosis.