Effect of cetrimide 2% with and without photodynamic therapy to reduce Streptococcus mutans burden in dentinal carious lesions.

To evaluate the use of cetrimide alone and combined with photodynamic therapy to reduce S. mutans burden in carious lesions. Sixty permanent third molars were sectioned and the coronal dentin exposed. A cariogenic challenge was performed using brain-heart infusion (BHI) medium supplemented and S. mutans ATCC 25175. Specimens were incubated in anaerobic jars at 37 °C for 15 days, with BHI renewed every 24 h. After 15 days, specimens were randomly divided into six groups (n = 10): C, control (no treatment); CHX, application of chlorhexidine 2%; CT, application of cetrimide 2%; CT+aPDT, application of cetrimide 2% followed by methylene blue dye and aPDT (antimicrobial photodynamic therapy: wavelength 660 nm, energy 4J, power 100 mW, spot size 0.0028 cm2, energy density 142 J/cm2 for 40 s); ES+aPDT, application of experimental solution (methylene blue dye with cetrimide) and aPDT; and aPDT alone. Carious tissue from each specimen was collected before and after the applications. Five decimal dilutions were performed, and the resulting solution was seeded in mitis-salivarius-bacitracin agar. Plates were incubated in anaerobic jars at 37 °C for 48 h. Analysis of variance (ANOVA) with post hoc Tukey's test was used to compare total S. mutans counts. Significant reductions in S. mutans were observed after application of CT+aPDT (0.30 (0.97), p < 0.0001) and ES+aPDT (0.52 (1.13), p < 0.0001). Cetrimide 2% with methylene blue dye, applied consecutively or as a mixture, can be used as a photosensitizing agent for aPDT to reduce S. mutans burden in dentinal caries.

Genome Sequence of Beauveria bassiana Strain ATCC 74040, a Widely Employed Insect Pathogen.

The broad-spectrum insecticidal activity of Beauveria bassiana strain ATCC 74040 is well documented. The whole-genome sequence of this strain is reported here, revealing a plethora of genes related to its insecticidal potential and providing new insights on the mechanism of action.

Phytoplasma SAP11 effector destabilization of TCP transcription factors differentially impact development and defence of Arabidopsis versus maize.

Phytoplasmas are insect-transmitted bacterial pathogens that colonize a wide range of plant species, including vegetable and cereal crops, and herbaceous and woody ornamentals. Phytoplasma-infected plants often show dramatic symptoms, including proliferation of shoots (witch's brooms), changes in leaf shapes and production of green sterile flowers (phyllody). Aster Yellows phytoplasma Witches' Broom (AY-WB) infects dicots and its effector, secreted AYWB protein 11 (SAP11), was shown to be responsible for the induction of shoot proliferation and leaf shape changes of plants. SAP11 acts by destabilizing TEOSINTE BRANCHED 1-CYCLOIDEA-PROLIFERATING CELL FACTOR (TCP) transcription factors, particularly the class II TCPs of the CYCLOIDEA/TEOSINTE BRANCHED 1 (CYC/TB1) and CINCINNATA (CIN)-TCP clades. SAP11 homologs are also present in phytoplasmas that cause economic yield losses in monocot crops, such as maize, wheat and coconut. Here we show that a SAP11 homolog of Maize Bushy Stunt Phytoplasma (MBSP), which has a range primarily restricted to maize, destabilizes specifically TB1/CYC TCPs. SAP11MBSP and SAP11AYWB both induce axillary branching and SAP11AYWB also alters leaf development of Arabidopsis thaliana and maize. However, only in maize, SAP11MBSP prevents female inflorescence development, phenocopying maize tb1 lines, whereas SAP11AYWB prevents male inflorescence development and induces feminization of tassels. SAP11AYWB promotes fecundity of the AY-WB leafhopper vector on A. thaliana and modulates the expression of A. thaliana leaf defence response genes that are induced by this leafhopper, in contrast to SAP11MBSP. Neither of the SAP11 effectors promote fecundity of AY-WB and MBSP leafhopper vectors on maize. These data provide evidence that class II TCPs have overlapping but also distinct roles in regulating development and defence in a dicot and a monocot plant species that is likely to shape SAP11 effector evolution depending on the phytoplasma host range.