MALDI-TOF MS Andromas strategy for the routine identification of bacteria, mycobacteria, yeasts, Aspergillus spp. and positive blood cultures

Clin Microbiol Infect 2012; 18: 1117-1125 ABSTRACT: All organisms usually isolated in our laboratory are now routinely identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) using the Andromas software. The aim of this study was to describe the use of this strategy in a routine clinical microbiology laboratory. The microorganisms identified included bacteria, mycobacteria, yeasts and Aspergillus spp. isolated on solid media or extracted directly from blood cultures. MALDI-TOF MS was performed on 2665 bacteria isolated on solid media, corresponding to all bacteria isolated during this period except Escherichia coli grown on chromogenic media. All acquisitions were performed without extraction. After a single acquisition, 93.1% of bacteria grown on solid media were correctly identified. When the first acquisition was not contributory, a second acquisition was performed either the same day or the next day. After two acquisitions, the rate of bacteria identified increased to 99.2%. The failures reported on 21 strains were due to an unknown profile attributed to new species (9) or an insufficient quality of the spectrum (12). MALDI-TOF MS has been applied to 162 positive blood cultures. The identification rate was 91.4%. All mycobacteria isolated during this period (22) were correctly identified by MALDI-TOF MS without any extraction. For 96.3% and 92.2% of yeasts and Aspergillus spp., respectively, the identification was obtained with a single acquisition. After a second acquisition, the overall identification rate was 98.8% for yeasts (160/162) and 98.4% (63/64) for Aspergillus spp. In conclusion, the MALDI-TOF MS strategy used in this work allows a rapid and efficient identification of all microorganisms isolated routinely.     

Isolated skin recurrence following salvage mastectomy for intramammary recurrence (after initial breast conservation therapy): is it a fatal event?

Aims

The authors analyzed the outcome of patients with Isolated Skin Recurrence After Salvage Mastectomy (ISRASM) performed after conservative treatment for breast carcinoma, taking into account initial tumor characteristics, intramammary recurrence (first recurrence) characteristics, local skin recurrence (second recurrence) characteristics, and the type of treatment at each stage of the breast cancer continuum.

Methods

Forty-two patients who had ISRASM between 1976 and 2007 were included in this retrospective study. Twenty-six factors were studied in univariate and multivariate analyses.

Results

Mean Overall Survival (OS) was 70.3 (±4.1) months. The 5-year OS rate was 66.6%. 31% of patients did not present any recurrence, 52% had locoregional recurrence and 14% metastatic recurrence following ISRASM. Univariate analysis showed that 4 prognostic factors were significantly related to OS and/or Disease-Free Survival (DFS): (1) initial chemotherapy after primary breast cancer (P = 0.09 and 0.01 respectively), (2) presence of emboli at the site of intramammary recurrence (first recurrence) (P = 0.02 and 0.03), (3) interval between first and second surgery of less than 3 years (P = 0.09 and 0.0003), and (4) inflammatory skin involvement at ISRASM (P = 0.005 and 0.17). Multivariate analysis showed that presence of emboli at the site of intramammary recurrence was significantly related to OS and that an interval between first and second recurrence of less than 3 years was significantly related to DFS.

Conclusion

Our results show that ISRASM affects a group of breast cancer patients with predominantly local rather than metastatic disease. Prognostic factors depend on characteristics at initial breast cancer, first recurrence and second recurrence. Evidence-based guidelines are still required for ISRASM management.     

Cell culture medium composition and translational adult bone marrow-derived stem cell research

For most therapeutic strategies using MSC, the preliminary amplification is carried out in media containing fetal calf serum (FCS). The theoretical health risk of using a xenogenic serum, a recent practice for which we have limited data, cannot be underestimated, while amplification using human serum (HS) remains controversial. At present, the available information on multipotentiality, self-renewal, and transplantability does not permit the selection of FCS rather than HS. Cellular modifications observed during cell passage seem to indicate a gradual impairment of cells in relation to native MSC, suggesting the making of short cell cultures without necessarily trying to reinfuse a high number of MSC in patients. With this approach, the volume of HS required would remain limited. While clinical studies have already started, many problems remain, such as evaluating the quality of the initial mesenchymal compartment and the biological properties of the cell suspension with FCS compared to those with HS, and depending on culture time.     

Solid-Solid Transformation in Racemic Ibuprofen

Purpose

To clarify the polymorphism of racemic Ibuprofen and to determine the kinetic of the phase transformation that follows crystallisation of phase II.

Methods

Differential Scanning Calorimetry (DSC), X-ray powder diffraction and Hot Stage Microscopy are complementarily used to perform a kinetic investigation of the particular temperature range where competition between the occurrence of phases I and II is suspected.

Results

Experiments performed with the three techniques reveal that at 273?K the crystallisation to phase II is then followed by a solid-solid transition towards phase I. This transformation is exothermic (conversion enthalpy of 8.0?±?0.5?kJ/mol), which proves that the two phases form a monotropic set. The kinetics of conversion deduced from X-Ray experiments follows a Johnson-Mehl-Avrami equation and the Hot Stage Microscopy allows us to establish that the transformation proceeds by the growth of some nuclei of phase I probably formed at lower temperature.

Conclusions

These results allow us to precise the stability pattern of racemic Ibuprofen and to establish the kinetic conditions of appearance and interconversion of the different phases. Therefore such real time resolved investigations would help if applied in the screening of polymorphs when competitive crystallisations occur.