Clostridium (C.) perfringens is the causative agent of several diseases and enteric infections in animals and humans. The pathogenicity of the bacterium is largely mediated by the production of a wide range of toxins. Individual C. perfringens strains produce only subsets of this toxin repertoire, which permits the classification in seven toxinotypes (A–G). In addition, a variety of minor toxins further characterizes the single strains. The aim of this work was to evaluate, using Polymerase Chain Reaction (PCR) assays, the diversity of 632 C. perfringens strains isolated in Italy over 15 years. The genotyped strains were analyzed to determine the presence of major and minor toxins (cpe, consensus, and atypical cpb2), their geographical origins, and the source of isolation (animal species or food). Our study shows that toxinotype A had the greatest representation (93%) and correlated mainly with consensus cpb2 in a variety of animal species, as well as with atypical cpb2 in the five food samples. Type D, associated with cpe and atypical cpb2 minor toxins, was identified in 3% of the cases, and type F was identified in 2.5%. Seven type C isolates (1.1%) were detected in cattle, whereas the only type B atypical cpb2 isolated in Italy was detected in a goat, and one type E cpe+atypical cpb2 was detected in a sheep. Type G was not detected.
Tuberculin skin test based on in vivo intradermal inoculation of purified protein derivative from Mycobacterium bovis (bPPD) is the diagnostic test for the control and surveillance of bovine tuberculosis (bTB). Proteomic analysis was performed on different bPPD preparations from M. bovis, strain AN5. Proteins were precipitated from bPPD solutions by TCA precipitation. The proteome of bPPD preparations was investigated by bottom-up proteomics, which consisted in protein digestion and nano-LC–MS/MS analysis. Mass spectrometry analysis was performed on a Q-exactive hybrid quadrupole-Orbitrap mass spectrometer coupled online to an Easy nano-LC1000 system. Three hundred and fifty-six proteins were identified and quantified by at least 2 peptides (99% confidence per peptide). One hundred and ninety-eight proteins, which had not been previously described, were detected; furthermore, the proteomic profile shared 80 proteins with previous proteomes from bPPDs from the United Kingdom and Brazil and 139 protein components from bPPD from Korea. Locus name of M. bovis (Mb) with orthologs from M. tuberculosis H37Rv, comparative gene and protein length, molecular mass, functional categories, gene name and function of each protein were reported. Ninety-two T cell mycobacterial antigens responsible for delayed-type hypersensitivity were detected, fifty-two of which were not previously reported in any bPPD proteome. Data are available via ProteomeXchange with identifier PXD005920. This study represents the highest proteome coverage of bPPD preparations to date. Since proteins perform cellular functions essential to health and/or disease, obtaining knowledge of their presence and variance is of great importance in understanding disease states and for advancing translational studies. Therefore, to better understand Mycobacterium tuberculosis complex biology during infection, survival, and persistence, the reproducible evaluation of the proteins that catalyze and control these processes is critically important. More active and more specific tuberculins would be desirable. Indeed, many antigens contained within bPPD are currently responsible for the cross-reactivity resulting in false-positive results as they are shared between non-tuberculous and tuberculous mycobacteria.
Tuberculins purified protein derivatives (PPDs) are obtained by precipitation from heat treated mycobacteria. PPDs are used in diagnosis of mycobacterial infections in humans and animals. Bovine PPD (PPDB) is obtained from Mycobacterium bovis (Mycobacterium tuberculosis complex), while Avian PPD (PPDA) and Johnin PPD (PPDJ) are extracted, respectively, from Mycobacterium avium and M. avium subsp. paratuberculosis (M. avium complex). PPDB and PPDA are used for bovine tuberculosis diagnosis, while PPDJ is experimentally used in the immunodiagnosis of paratuberculosis. Although PPDs date back to the 19th Century, limited knowledge about their composition is currently available. The goal of our study was to evaluate Fourier Transform InfraRed (FTIR) spectroscopy as a tool to differentiate PPDB, PPDA, and three PPDJs. The results highlighted that the three PPDs have specific profiles, correlated with phylogenetic characteristics of mycobacteria used for their production. This analysis is eligible as a specific tool for different PPDs batches characterization and for the assessment of their composition. The entire PPD production may be efficiently controlled, since the N content of each preparation is related to IR spectra, with a reference spectrum for each PPD and a standardized analysis protocol.
Background: Veterinary autogenous vaccines, similar to all injectable pharmaceutical products, must be tested to assess endotoxin concentrations. The Limulus Amebocyte Lysate Test (LAL test) is widely used in in vitro quality control assays for endotoxin detection, although it presents some ethical issues related to the production of reagents and is also characterized by a low specificity due to other contaminants that can activate the reaction. For all these reasons, a new recombinant factor C LAL test was developed. Aim: In this study, we described the comparison between two LAL test methods for in vitro quality control of veterinary autogenous vaccines, with the aim of evaluating the most suitable method and establishing an endotoxin concentration range for two different matrices. Methods: Two hundred batches of two different vaccine matrices were tested using the kinetic chromogenic LAL test and recombinant factor C endotoxin detection assay commercial kits. Results and Conclusions: Statistical analysis conducted after the validation of the recombinant factor C test exhibited a statistically significant correlation between the two methods and for both vaccine matrices, suggesting that the animal-free assay can be used as a routine quality control test for veterinary autogenous vaccines.
Adipose-derived mesenchymal stromal cells (MSCs) are extensively studied in both human and veterinary medicine. Their isolation is usually performed by collagenase digestion followed by filtration and removal of nonadherent tissue remnants 48 h after seeding. We observed that waste tissue fragments contain cells that adhere belatedly to the plastic. We aimed to investigate their basic properties to speculate on the possible existence of MSC subpopulations. Adipose tissue from three dogs was enzymatically digested. Three cell populations that adhered to the culture plastic 48, 96, and 144 h after seeding were obtained. After expansion, they were analyzed by flow cytometry for MSC-positive (CD90, CD44, and CD29) and -negative (CD14, MHCII, and CD45) markers as well as for endothelial, pericyte, and smooth muscle cell markers (CD31, CD146, and alpha-SMA). Furthermore, cells were assessed for viability, doubling time, and trilineage differentiation ability. No significant differences were found between the three subpopulations. As a result, this procedure has proven to be a valuable method for dramatically improving MSCs yield. As a consequence of cell recovery optimization, the amount of tissue harvested could be reduced, and the time required to obtain sufficient cells for clinical applications could be shortened. Further studies are needed to uncover possible different functional properties.