The Occurrence of Photorhabdus-Like Toxin Complexes in Bacillus thuringiensis

Recently, genomic sequencing of a Bacillus thuringiensis (Bt) isolate from our collection revealed the presence of an apparent operon encoding an insecticidal toxin complex (Tca) similar to that first described from the entomopathogen Photorhabdus luminescens. To determine whether these genes are widespread among Bt strains, we screened isolates from the collection for the presence of tccC, one of the genes needed for the expression of fully functional toxin complexes. Among 81 isolates chosen to represent commonly encountered biochemical phenotypes, 17 were found to possess a tccC. Phylogenetic analysis of the 81 isolates by multilocus sequence typing revealed that all the isolates possessing a tccC gene were restricted to two sequence types related to Bt varieties morrisoni, tenebrionis, israelensis and toumanoffi. Sequencing of the ∼17 kb tca operon from two isolates representing each of the two sequence types revealed >99% sequence identity. Optical mapping of DNA from Bt isolates representing each of the sequence types revealed nearly identical plasmids of ca. 333 and 338 kbp, respectively. Selected isolates were found to be toxic to gypsy moth larvae, but were not as effective as a commercial strain of Bt kurstaki. Some isolates were found to inhibit growth of Colorado potato beetle. Custom Taqman® relative quantitative real-time PCR assays for Tc-encoding Bt revealed both tcaA and tcaB genes were expressed within infected gypsy moth larvae

Impact of Atraumatic Restorative Treatment (ART) on the treatment profile in pilot government dental clinics in Tanzania

\ud The predominant mode of treatment in government dental clinics in Tanzania has been tooth extraction because the economy could not support the conventional restorative care which depends on expensive equipment, electricity and piped water systems. Atraumatic Restorative Treatment (ART) was perceived as a suitable alternative. A 3.5-year study was designed to document the changes in the treatment profiles ascribed to the systematic introduction of ART in pilot government dental clinics. Dental practitioners who were working in 13 government dental clinics underwent a 7-day ART training. Treatment record data on teeth extracted and teeth restored by the conventional and ART approaches were collected from these clinics for the three study periods. The mean percentage of ART restorations to total treatment, ART restorations to total restorations, and total restorations to total treatments rendered were computed. Differences between variables were determined by ANOVA, t-test and Chi-square. The mean percentage of ART restorations to total treatment rendered was 0.4 (SE = 0.5) and 11.9 (SE = 1.1) during the baseline and second follow-up period respectively (ANOVA mixed model; P < 0.0001). The mean percentage of ART restorations to total restorations rendered at baseline and 2nd follow-up period was 8.4% and 88.9% respectively (ANOVA mixed model; P < 0.0001). The mean percentage of restorations to total treatment rendered at baseline and 2nd follow-up was 3.9% and 13.0%, respectively (ANOVA mixed model; P < 0.0001). Ninety-nine percent of patients were satisfied with ART restorations, 96.6% willing to receive ART restoration again in future, and 94.9% willing to recommend ART treatment to their close relatives. ART introduction in pilot government dental clinics raised the number of teeth saved by restorative care. Countrywide introduction of the ART approach in Tanzania is recommended\u

Deep sequencing-based transcriptome analysis of Plutella xylostella larvae parasitized by Diadegma semiclausum

Background: Parasitoid insects manipulate their hosts' physiology by injecting various factors into their host upon parasitization. Transcriptomic approaches provide a powerful approach to study insect host-parasitoid interactions at the molecular level. In order to investigate the effects of parasitization by an ichneumonid wasp (Diadegma semiclausum) on the host (Plutella xylostella), the larval transcriptome profile was analyzed using a short-read deep sequencing method (Illumina). Symbiotic polydnaviruses (PDVs) associated with ichneumonid parasitoids, known as ichnoviruses, play significant roles in host immune suppression and developmental regulation. In the current study, D. semiclausum ichnovirus (DsIV) genes expressed in P. xylostella were identified and their sequences compared with other reported PDVs. Five of these genes encode proteins of unknown identity, that have not previously been reported

Changes to the Fossil Record of Insects through Fifteen Years of Discovery

The first and last occurrences of hexapod families in the fossil record are compiled from publications up to end-2009. The major features of these data are compared with those of previous datasets (1993 and 1994). About a third of families (>400) are new to the fossil record since 1994, over half of the earlier, existing families have experienced changes in their known stratigraphic range and only about ten percent have unchanged ranges. Despite these significant additions to knowledge, the broad pattern of described richness through time remains similar, with described richness increasing steadily through geological history and a shift in dominant taxa, from Palaeoptera and Polyneoptera to Paraneoptera and Holometabola, after the Palaeozoic. However, after detrending, described richness is not well correlated with the earlier datasets, indicating significant changes in shorter-term patterns. There is reduced Palaeozoic richness, peaking at a different time, and a less pronounced Permian decline. A pronounced Triassic peak and decline is shown, and the plateau from the mid Early Cretaceous to the end of the period remains, albeit at substantially higher richness compared to earlier datasets. Origination and extinction rates are broadly similar to before, with a broad decline in both through time but episodic peaks, including end-Permian turnover. Origination more consistently exceeds extinction compared to previous datasets and exceptions are mainly in the Palaeozoic. These changes suggest that some inferences about causal mechanisms in insect macroevolution are likely to differ as well

ART integration in oral health care systems in Latin American countries as perceived by directors of oral health

The aim of this study was to carry out a situation analysis of: a) prevalence of ART training courses; b) integration of ART into the oral healthcare systems and; c) strengths and weaknesses of ART integration, in Latin American countries. MATERIALS AND METHODS: A structured questionnaire, consisting of 18 questions, was emailed to directors of national or regional oral health departments of all Latin American countries and the USA. For two countries that had not responded after 4 weeks, the questionnaire was sent to the Dean of each local Dental School. The questions were related to ART training courses, integration of ART in the dental curriculum and the oral healthcare system, barriers to ART implementation in the public health system and recommendations for ART implementation in the services. Factor analysis was used to construct one factor in the barrier-related question. Means and percentages were calculated. RESULTS: The response rate, covering 55% of all Latin American countries, was 76%. An ART training course had been given in all Latin American countries that responded, with more than 2 having been conducted in 64.7% of the respondent countries. ART was implemented in public oral health services in 94.7 % of the countries, according to the respondents. In 15.8% of the countries, ART was applied throughout the country and in 68.4%, in some areas or regions of a country. ART had been used for more, or less, than three years in 42.1% and 47.4% of the countries, respectively. Evaluation and monitoring activities to determine the effectiveness of ART restorations and ART sealants had been carried out in 42.1% of the countries, while evaluation training courses had taken place in only 3 countries (15.8%). Respondents perceived the "increase in the number of treated patients" as the major benefit of ART implementation in public oral health services. The major perceived barrier factors to ART implementation were "operator opinion" and "high patient load", followed by "lack in supplies of materials and instruments and operators" and "lack of ART training". Respondents recommended that the number of ART courses should be increased. CONCLUSIONS: The introduction of ART into the public oral health systems in Latin American countries has taken place but is still in its infancy. More ART training courses need to be organized if the approach is to be adopted in oral health service systems in these countries

Pay for performance: will dentistry follow?

<p>Abstract</p> <p>Background</p> <p>"Pay for performance" is an incentive system that has been gaining acceptance in medicine and is currently being considered for implementation in dentistry. However, it remains unclear whether pay for performance can effect significant and lasting changes in provider behavior and quality of care. Provider acceptance will likely increase if pay for performance programs reward true quality. Therefore, we adopted a quality-oriented approach in reviewing those factors which could influence whether it will be embraced by the dental profession.</p> <p>Discussion</p> <p>The factors contributing to the adoption of value-based purchasing were categorized according to the Donabedian quality of care framework. We identified the dental insurance market, the dental profession position, the organization of dental practice, and the dental patient involvement as structural factors influencing the way dental care is practiced and paid for. After considering variations in dental care and the early stage of development for evidence-based dentistry, the scarcity of outcome indicators, lack of clinical markers, inconsistent use of diagnostic codes and scarcity of electronic dental records, we concluded that, for pay for performance programs to be successfully implemented in dentistry, the dental profession and health services researchers should: 1) expand the knowledge base; 2) increase considerably evidence-based clinical guidelines; and 3) create evidence-based performance measures tied to existing clinical practice guidelines.</p> <p>Summary</p> <p>In this paper, we explored factors that would influence the adoption of value-based purchasing programs in dentistry. Although none of these factors were essential deterrents for the implementation of pay for performance programs in medicine, the aggregate seems to indicate that significant changes are needed before this type of program could be considered a realistic option in dentistry.</p