Assessment of Composite Restorations and Their Unique Features in Forensic Identification of Unidentified Human Beings

Background: Dental identification mainly involves the comparison of antemortem and postmortem records. Keiser-Nielson (1980) recommended restored tooth surfaces as the smallest unit to consider in the comparison of dental restorations for identification purposes. Unique appearance of radiographic images of amalgam has led to their application in dental forensic. The present study aimed to investigate the value of composite restorations and their features in forensic identification.Methods: The antemortem sample included 40 periapical radiographs of anterior teeth with class III composite restorations which had been taken at least one year before the study. Ten randomly selected recent radiographs of the same subjects along with two radiographs from other patients were regarded as postmortem samples. Afterward, 12 dentally trained examiners were asked to match the 12 radiographs of group 2 with those of group 1 and to determine which features of the teeth (e.g. shape, contour, and surface) had helped them.Results: Ten examiners were able to correctly match all of the 12 images. According to kappa coefficient, the inter-rater agreement was high (0.8-1.0). The shape of the restoration was the most useful feature in identification.Conclusion: A composite restoration has a unique radiographic morphology that can be used for human identification. Therefore, if the antemortem radiograph of a single composite restoration is available, its comparison with a postmortem radiograph can help identify unidentified human beings

Extended-spectrum ß-lactamase, AmpC-producing, and fluoroquinolone-resistant Escherichia coli in retail broiler chicken meat, Italy

Background: Globally, antimicrobial drug-resistant Escherichia coli is among the most common etiological agents of invasive disease in humans. In Europe, increasing proportions of infections due to third-generation cephalosporins and/or fluoroquinolone-resistant extraintestinal pathogenic E. coli (ExPEC) strains are reported. E. coli from poultry are those more closely linked to human E. coli, but lack of reliable data makes it difficult to assess the attributable risk of different food sources. In the present study, our objective was to investigate the antimicrobial resistance profile, phylogenetic background, and virulence factors of E. coli isolates from broiler chicken meat sold at retail in Palermo, Italy. Materials and Methods: Isolation of multidrug resistant (MDR) E. coli was performed during April-December 2013 on a total of 163 chicken meat samples. Susceptibility to a panel of nine antimicrobial agents was determined. PCR assays were carried out to detect extended-spectrum β-lactamase (ESBL), plasmid-mediated AmpC β-lactamase, and plasmid-mediated quinolone resistance (PMQR) genes, phylogenetic group, and ExPEC-associated traits. A single nucleotide polymorphism (SNP) PCR was done to detect E. coli sequence type (ST)131. Results: One hundred thirty-four isolates from 109 meat samples were MDR. B1 was the most prevalent phylogenetic group (47.8%), followed by groups D (25.4%), A (22.3%), and B2 (4.5%). ESBLs and AmpC β-lactamases were detected by PCR in 132 (98.5%) and 15 (11.2%) isolates. PMQR determinants were detected in 122 (91%) isolates. Twenty-two MDR isolates met the molecular definition of ExPEC. SNP-PCR results confirmed that four B2 isolates were ST131. Enterobacterial Repetitive Intergenic Consensus sequence-PCR analysis showed a large heterogeneity with 55 unique profiles and 31 clusters including 2-4 isolates. Conclusions: An alarmingly high prevalence of MDR E. coli from broiler chicken meat is evident in our geographic area. The ongoing use of antimicrobial drugs in livestock should be urgently restricted, particularly in the poultry sector

Rapid, cost-effective, sensitive and quantitative detection of Acinetobacter baumannii from pneumonia patients

BACKGROUND AND OBJECTIVES: Pneumonia with Acinetobacter baumannii has a major therapeutic problem in health care settings. Decision to initiate correct antibiotic therapy requires rapid identification and quantification of organism. The aim of this study was to develop a rapid and sensitive method for direct detection of A. baumannii from respiratory specimens. MATERIALS AND METHODS: A Taqman real time PCR based on the sequence of bla(oxa-51) was designed and used for direct detection of A. baumannii from 361 respiratory specimens of patients with pneumonia. All specimens were checked by conventional bacteriology in parallel. RESULTS: The new real time PCR could detect less than 200 cfu per ml of bacteria in specimens. There was agreement between the results of real time PCR and culture (Kappa value 1.0, p value<0.001). The sensitivity, specificity and predictive values of real time PCR were 100%. The prevalence of A. baumannii in pneumonia patients was 10.53 % (n=38). Poly-microbial infections were detected in 65.71% of specimens. CONCLUSION: Acinetobacter baumannii is the third causative agent in nosocomial pneumonia after Pseudomonas aeroginosa (16%) and Staphylococcus aureus (13%) at Tehran hospitals. We recommend that 104 CFU be the threshold for definition of infection with A. baumannii using real time PCR

Development of a modified DNA extraction method for pulsed-field gel electrophoresis analysis of Staphylococcus aureus and enterococci without using lysostaphin

A modified pulsed-field gel electrophoresis (PFGE) protocol was developed and applied to clinical isolates of Staphylococcus aureus and enterococci to reduce the cost of using lysostaphin. This protocol reduces the expenses of PFGE typing of S. aureus and enterococci as it removes the use of lysostaphin during the spheroplast formation from these bacteria

Development of a new DNA extraction protocol for PFGE typing of Mycobacterium tuberculosis complex.

A modified pulsed-field gel electrophoresis (PFGE) protocol was developed and applied to clinical isolates of Mycobacterium tuberculosis complex to reduce the cost of using lyticase. This protocol reduces the expense of PFGE typing of Mycobacterium tuberculosis complex as it removes the use of lyticase during the spheroplast formation from these bacteri

Detection and quantification of Streptococcus pneumoniae from Iranian patients with pneumonia and individual carriers by real time PCR

The aim of this study was to develop a real time polymerase chain reaction (PCR) for quantitative detection of Streptococcus pneumoniae from clinical respiratory specimens. Initially, 184 respiratory specimens from patients with community acquired pneumonia (CAP) (n = 129) and 55 cases with hospital associated pneumonia (HAP) were bacteriologically investigated. To check the colonization status among the healthy individuals, 32 preschool and 31 adults were screened in parallel. All specimens were cultured on selective culture media to isolate S. pneumoniae, Legionella spp. and Mycoplasma spp. A 166 bp fragment corresponding to cbp A gene of S. pneumoniae was amplified from clinical specimens using Taqman probe real time PCR. Culture showed 14, but real time PCR showed 15 specimens as being positive for S. pneumoniae. The specificity and sensitivity of real time PCR was 99.14% and 100 respectively. Co-infections of S. pneumoniae with Legionella pneumophila, Chlamydophila pneumoniae, Mycoplasma pneumoniae and Staphylococcus aureus were observed in 5 cases (35.72%). S. pneumoniae was counted &lt;103 cfu/ml from the co-infected cases. Using real time PCR, a cutoff of 103cfu/ml is introduced to differentiate colonization from infection in respiratory tract. This is the first report on the prevalence CAP with S. pneumoniae in Iran (12.40%).Key words: Streptococcus pneumoniae, community acquired pneumonia (CAP), real time polymerase chain reaction (PCR), choline binding protein A (cbp A)

Single tube real time PCR for detection of Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydophila pneumoniae and Legionella pneumophila from clinical samples of CAP

We designed a multiplex real time PCR for rapid, sensitive and specific detection of Streptococcus pneumoniae, Legionella pneumophila, Chlamydophila pneumoniae and Mycoplasma pneumoniae. The study cases consisted of 129 patients with community acquired pneumonia (CAP). Bacteriological techniques were implemented for detection of the cultivable organisms. DNA were extracted from sputa, throat swabs, bronchoalveolar lavages and tracheal aspirates and used as templates in real time PCR. The primers and probes were designed for cbpA (S. pneumoniae), p1adhesin (M. pneumoniae), mip (L. pneumophila) and ompA (C. pneumoniae). After optimization of real time PCR for every organism, the experiments were continued in multiplex in a single tube. Of 129 CAP specimens, the positive cultures included 14 (10.85) for S. pneumoniae, 9 (6.98) for L. pneumophila and 3 (2.33) for M. pneumoniae. Four specimens (3.10) were positive for C. pneumoniae by real time PCR. The sensitivity of our real time PCR was 100 for all selected bacteria. The specificity of the test was 98.26, 98.34, 100 and 100 for S. pneumoniae, L. pneumophila, M. pneumoniae and C. pneumoniae, respectively. This is the first report on the use of multiplex real time PCR for detection of CAP patients in the Middle East. The method covers more than 90 of the bacterial pathogens causing CAP. © 2012 Akadémiai Kiadó, Budapest

Predicting the Impact of Multiwalled Carbon Nanotubes on the Cement Hydration Products and Durability of Cementitious Matrix Using Artificial Neural Network Modeling Technique

In this study the feasibility of using the artificial neural networks modeling in predicting the effect of MWCNT on amount of cement hydration products and improving the quality of cement hydration products microstructures of cement paste was investigated. To determine the amount of cement hydration products thermogravimetric analysis was used. Two critical parameters of TGA test are PHP loss and CH loss . In order to model the TGA test results, the ANN modeling was performed on these parameters separately. In this study, 60% of data are used for model calibration and the remaining 40% are used for model verification. Based on the highest efficiency coefficient and the lowest root mean square error, the best ANN model was chosen. The results of TGA test implied that the cement hydration is enhanced in the presence of the optimum percentage (0.3 wt%) of MWCNT. Moreover, since the efficiency coefficient of the modeling results of CH and PHP loss in both the calibration and verification stages was more than 0.96, it was concluded that the ANN could be used as an accurate tool for modeling the TGA results. Another finding of this study was that the ANN prediction in higher ages was more precise

Ancient and recent differences in the intrinsic susceptibility of Mycobacterium tuberculosis complex to pretomanid

OBJECTIVES: To develop a robust phenotypic antimicrobial susceptibility testing (AST) method with a correctly set breakpoint for pretomanid (Pa), the most recently approved anti-tuberculosis drug. METHODS: The Becton Dickinson Mycobacterial Growth Indicator Tube™ (MGIT) system was used at six laboratories to determine the MICs of a phylogenetically diverse collection of 356 Mycobacterium tuberculosis complex (MTBC) strains to establish the epidemiological cut-off value for pretomanid. MICs were correlated with WGS data to study the genetic basis of differences in the susceptibility to pretomanid. RESULTS: We observed ancient differences in the susceptibility to pretomanid among various members of MTBC. Most notably, lineage 1 of M. tuberculosis, which is estimated to account for 28% of tuberculosis cases globally, was less susceptible than lineages 2, 3, 4 and 7 of M. tuberculosis, resulting in a 99th percentile of 2 mg/L for lineage 1 compared with 0.5 mg/L for the remaining M. tuberculosis lineages. Moreover, we observed that higher MICs (≥8 mg/L), which probably confer resistance, had recently evolved independently in six different M. tuberculosis strains. Unlike the aforementioned ancient differences in susceptibility, these recent differences were likely caused by mutations in the known pretomanid resistance genes. CONCLUSIONS: In light of these findings, the provisional critical concentration of 1 mg/L for MGIT set by EMA must be re-evaluated. More broadly, these findings underline the importance of considering the global diversity of MTBC during clinical development of drugs and when defining breakpoints for AST

Expanding the Grading of Recommendations Assessment, Development, and Evaluation (Ex-GRADE) for Evidence-Based Clinical Recommendations: Validation Study

Clinicians use general practice guidelines as a source of support for their intervention, but how much confidence should they place on these recommendations? How much confidence should patients place on these recommendations? Various instruments are available to assess the quality of evidence of research, such as the revised Wong scale (R-Wong) which examines the quality of research design, methodology and data analysis, and the revision of the assessment of multiple systematic reviews (R-AMSTAR), which examines the quality of systematic reviews