A new role for PGRP-S (Tag7) in immune defense: lymphocyte migration is induced by a chemoattractant complex of Tag7 with Mts1

PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4⁺ and CD8⁺ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.     

Antimicrobial Resistance, Virulence Genes, and Genetic Lineages of Staphylococcus pseudintermedius in Healthy Dogs in Tunisia

Nasal swabs of 100 healthy dogs were obtained in 2011 in Tunisia and tested for Staphylococcus pseudintermedius recovery. Antimicrobial resistance profile and virulence gene content were determined. Multilocus-sequence-typing (MLST) and SmaI-pulsed-field gel electrophoresis (PFGE) were investigated. S. pseudintermedius was recovered in 55 of the 100 tested samples (55 %), and one isolate per sample was further studied. All 55 S. pseudintermedius isolates were susceptible to methicillin (MSSP) but showed resistance to the following antimicrobials (% resistant isolates/resistance gene): penicillin (56.4/blaZ), tetracycline (40/tetM), trimethoprim-sulfamethoxazole (23.7), fusidic acid (9), kanamycin (3.7/aph(3´)-Ia), erythromycin-clindamycin (1.8/erm(B)), streptomycin (1.8/ant(6)-Ia), chloramphenicol (1.8) and ciprofloxacin (1.8). The following toxin genes were identified (% of isolates): lukS/F-I (98.2), expA (5.5), se-int (98.2), sec _canine (1.8), siet (100), sea (5.5), seb (3.6), sec (10.9), sed (54.5), sei (5.5), sej (29.1), sek (3.6), ser (9.1), and hlg _v (38.2). Ten different sequence-types were detected among 11 representative MSSP isolates: ST20, ST44, ST69, ST70, ST78, ST100, ST108, ST160, ST161, and ST162, the last three ones revealing novel alleles or allele combinations. Eleven different PFGE-patterns were identified in these isolates. The nares of healthy dogs could be a reservoir of antimicrobial resistant and virulent MSSP, highlighting the presence of the recently described exfoliating gene expA and several enterotoxin genes.     

Comparison of Media for the Isolation of Haemophilus species from Cases of Seasonal Conjunctivitis Associated with Severe Endemic Trachoma

Media for isolation of Haemophilus sp. from the conjuctiva were compared in an oasis in southern Tunisia where severe trachoma and seasonal epidemic purulent conjunctivitis are common. Of 89 children tested, IsoVitaleX-supplemented chocolate agar yielded Haemophilus in 87%, plain chocolate agar in 75%, sheep blood agar with a stab of Staphylococcus epidermidis in 74%, and Fildes medium in 58%. Since other microbial pathogens are easily identified in the modified blood agar, it was the most useful single medium.     

Toward multimodality oral cancer diagnosis in the XXI century: Blending cutting edge imaging and genomic/proteomic definition of suspicious lesions

If emergent genomic and proteomic approaches to early oral cancer detection are to be successful, a means of reliably and comprehensively identifying high-risk tissue sampling sites constitutes an essential step in the oral cancer screening process. Recent studies have determined that in vivo Optical Coherence Tomography (OCT) is a quick and user-friendly tool for detecting and mapping oral lesions, and that it can enhance diagnostic accuracy when using high resolution diagnostic techniques such as in vivo microscopy. Therefore OCT can potentially provide a means of improving the clinical usefulness of novel diagnostic approaches such as proteomics by identifying sites that need to be sampled.     

Identification of signature and primers specific to genus <Emphasis Type="Italic">Pseudomonas</Emphasis> using mismatched patterns of 16S rDNA sequences

Background

Pseudomonas, a soil bacterium, has been observed as a dominant genus that survives in different habitats with wide hostile conditions. We had a basic assumption that the species level variation in 16S rDNA sequences of a bacterial genus is mainly due to substitutions rather than insertion or deletion of bases. Keeping this in view, the aim was to identify a region of 16S rDNA sequence and within that focus on substitution prone stretches indicating species level variation and to derive patterns from these stretches that are specific to the genus.

Results

Repeating elements that are highly conserved across different species of Pseudomonas were considered as guiding markers to locate a region within the 16S gene. Four repeating patterns showing more than 80% consistency across fifty different species of Pseudomonas were identified. The sub-sequences between the repeating patterns yielded a continuous region of 495 bases. The sub-sequences after alignment and using Shanon's entropy measure yielded a consensus pattern. A stretch of 24 base positions in this region, showing maximum variations across the sampled sequences was focused for possible genus specific patterns. Nine patterns in this stretch showed nearly 70% specificity to the target genus. These patterns were further used to obtain a signature that is highly specific to Pseudomonas. The signature region was used to design PCR primers, which yielded a PCR product of 150 bp whose specificity was validated through a sample experiment.

Conclusions

The developed approach was successfully applied to genus Pseudomonas. It could be tried in other bacterial genera to obtain respective signature patterns and thereby PCR primers, for their rapid tracking in the environmental samples.

     

Epidemiological and clinical studies of ovine caseous lymphadenitis

A field survey was undertaken, to determine epidemiological, clinical and biological data on Ovine Caseous Lymphadenitis disease in 54 flocks originated from Sfax area in Tunisia. The mean morbidity rate of the cutaneous form was 5.1%. This form affected sheep over 3 months and under 2 years old. On the other hand, the mean morbidity rate of the visceral form, encountered in abattoirs, was 11.02%. The clinical aspect of the superficial (or cutaneous) form was often corresponding to one abscess, located particularly in the lymphatic nodes of the animal's head; while visceral (or internal) form of the disease was represented by the presence of a unique abscess found in the pulmonary lymphatic nodes. The macroscopic aspect of lesions showed that the size of abscess was comprised between 4 and 10 cm in diameter. At the cut, colour of the pus was white yellowish to yellow greyish with a fluid or a thick aspect like onion peels; pus was microscopic. Lesions were characterised by a fibrous shell, a pyogenic membrane and a necrotic center. Bacteriological research revealed that Corynebacterium pseudotuberculosis was the pathogen the most frequently isolated, followed by Staphylococcus aureus subsp anaerobius which was particularly found in sheep aged between 3 months and 2 years old.     

Meiotic analysis of four cross-pollinated generations in a synthetic autotetraploid population of husk tomato (<i>Physalis ixocarpa</i>)

The cultivated husk tomato (Physalis ixocarpa) (2n = 2x = 24) is native from Mexico and Central America and shows a wide genetic variation. Presently, it is the fourth horticultural crop in cultivation surface in Mexico. The working team of this research previously developed an autotetraploid population by using colchicine. The objectives of the present work were to analyze the ploidy level and meiotic behavior of the subsequent generations (C3, C4, C5, C6) from the original (C2) composed only by plants with the duplicated genome from the Rendidora cultivar, and to determine pollen viability. As a diploid control the cultivar Rendidora of P. ixocarpa was used. Ploidy level was determined by flow citometry and meiotic analysis. For the meiotic study, the microsporocytes were prepared by the squash method, stained with carmin and analyzed in diakinesis. Pollen viability was evaluated through 0.01% Buffalo Black staining. The tetraploid condition prevailed through four cross-pollinating generations, maintaining a constant chromosome number 2n = 4x = 48. In diakinesis, the chromosomes of the diploid cultivar were associated into bivalents, whereas in tetraploid plants the chromosomes associated into univalents, bivalents and trivalents. Highly significant differences in bivalent pairing were detected between autotetraploid plants and between generations. Pollen viability did not show significant differences between generations and allowed reproduction. These results indicate that it is possible to develop an autotetraploid cultivar, because the polyploid state is naturally maintained and the plants are fertile. Furthermore, given the differences in bivalent pairing between plants and generations, a response to selection toward meiotic stability is expected.     

Toward multimodality oral cancer diagnosis in the XXI century: Blending cutting edge imaging and genomic/proteomic definition of suspicious lesions

If emergent genomic and proteomic approaches to early oral cancer detection are to be successful, a means of reliably and comprehensively identifying high-risk tissue sampling sites constitutes an essential step in the oral cancer screening process. Recent studies have determined that in vivo Optical Coherence Tomography (OCT) is a quick and user-friendly tool for detecting and mapping oral lesions, and that it can enhance diagnostic accuracy when using high resolution diagnostic techniques such as in vivo microscopy. Therefore OCT can potentially provide a means of improving the clinical usefulness of novel diagnostic approaches such as proteomics by identifying sites that need to be sampled.     

An asymmetric approach to preserve common intervals while sorting by reversals

Background  

The reversal distance and optimal sequences of reversals to transform a genome into another are useful tools to analyse evolutionary scenarios. However, the number of sequences is huge and some additional criteria should be used to obtain a more accurate analysis. One strategy is searching for sequences that respect constraints, such as the common intervals (clusters of co-localised genes). Another approach is to explore the whole space of sorting sequences, eventually grouping them into classes of equivalence. Recently both strategies started to be put together, to restrain the space to the sequences that respect constraints. In particular an algorithm has been proposed to list classes whose sorting sequences do not break the common intervals detected between the two inital genomes A and B. This approach may reduce the space of sequences and is symmetric (the result of the analysis sorting A into B can be obtained from the analysis sorting B into A).