Background: Sheep caseous lymphadenitis (CLA), caused byCorynebacterium pseudotuberculosis(Cp), is associated with direct economic losses and presents significant zoonotic potential. Despite the importance of the disease, a satisfactory vaccine model has not been developed. Thus, this study aimed to investigate the association between haptoglobin (Hp) and IgM levels and the clinical progression of CLA in primarily infected sheep and in sheep immunized with Cp- secreted antigens adjuvanted withQuillaja saponariasaponins. These animals were kept with CLA-positive sheep to simulate natural exposure that occurs in field conditions. During the experiment, the Hp and IgM levels were monitored for 21 days, and the development of internal CLA lesions was investigated through necropsies on day182 post-immunization.Results: Primarily infected sheep in Group 2 (inoculated with 2x10⁵Cp virulent strain) had higher Hp values between the first and ninth days post inoculation (PI) than sheep in Group 1 (control; P < 0.05). Immunized animals in Group 3 had significantly higher Hp values between the third and seventh days PI, compared with the control group (P < 0.01). Binary logistic regression (BLR) analysis of primarily infected sheep indicated an association between Hp concentration and CLA clinical progression: animals with high Hp values had 99.9% less risk of having CLA abscesses than animals with low Hp levels (Odds ratio = 0.001, P < 0.05). Both experimental groups had significantly higher IgM titers than the control group around the ninth and eleventh days PI (P < 0.05). The BLR analysis for immunized sheep indicated an association between IgM levels and clinical progression: sheep with high IgM titers had 100.0% less risk of having CLA abscesses than animals with low IgM levels (Odds ratio = 0.000, P < 0.05).Conclusions: Resistance toC. pseudotuberculosisinfection is supported by the early acute phase response, in which up-regulation of Hp and IgM were predictive of a lower risk of CLA lesion development. Because the immunogen used in this study induced a high production of both Hp and IgM,Q. saponariasaponin should be considered a promising candidate in vaccine formulations against sheep CLA.

Caseous lymphadenitis (LC) is a chronic contagious disease caused by Corynebacterium pseudotuberculosis, which mainly affects goats and sheep. Vaccination is an effective but not yet well-established method, partly due to a lack of knowledge surrounding the most effective immunoprotective components. The present study aimed to quantify and compare the in vivo expression of genes pld (phospholipase D), cpp (CP40), nanH (neuraminidase H), sodC (superoxide dismutase C) and spaC (adhesin) using qRT-PCR, with the respective expression in vitro. Caseous material of abscesses removed from five animals was cultured, with colonies suggestive of C. pseudotuberculosis identified. RNA extraction was performed on these samples, as well as on the respective pellets derived from liquid cultures brain heart infusion. After evaluating RNA integrity, complementary DNA was synthesized, followed by the relative quantification each of the genes of interest. Mean mRNA expression of the five genes found in abscesses and in cultures differed significantly, with respective values of: nanH 811.50 ± 198.27 and 359.35 ± 75.45 (p = 0.009); cpp 856.31 ± 385.11 and 154.54 ± 94.34 (p = 0.0039); plD 922.70 ± 450.73 and 212.41 ± 153.10 (p = 0.016); sodC 1,293.53 ± 564.75 and 223.63 ± 145.58 (p = 0.016); spaC 1,157.10 ± 525.13 and 214.26 ± 125.70 (p = 0,016). Expression was observed to be 6–8 times higher in abscesses than in cultures, Indicative that is a genetic expression of the in vitro bacterium exists, yet in vivo has a greater magnitude corroborating to one of these virulence factors in the pathogenesis of LC.

Previous works defining antigens that might be used as vaccine targets against Corynebacterium pseudotuberculosis, which is the causative agent of sheep and goat caseous lymphadenitis, have focused on secreted proteins produced in a chemically defined culture media. Considering that such antigens might not reflect the repertoire of proteins expressed during infection conditions, this experiment aimed to investigate the membrane-associated proteins with pathogenic potential expressed by C. pseudotuberculosis grown directly in animal serum. Its membrane-associated proteins have been extracted using an organic solvent enrichment methodology, followed by LC–MS/MS and bioinformatics analysis for protein identification and classification. The results revealed 22 membrane-associated proteins characterized as potentially pathogenic. An interaction network analysis indicated that the four potentially pathogenic proteins ciuA, fagA, OppA4 and OppCD were biologically connected within two distinct network pathways, which were both associated with the ABC Transporters KEGG pathway. These results suggest that C. pseudotuberculosis pathogenesis might be associated with the transport and uptake of nutrients; other seven identified potentially pathogenic membrane proteins also suggest that pathogenesis might involve events of bacterial resistance and adhesion. The proteins herein reported potentially reflect part of the protein repertoire expressed during real infection conditions and might be tested as vaccine antigens.

As espécies do gênero Lippia (Verbenaceae) possuem diversas moléculas bioativas, oriundas do seu metabolismo secundário, que apresentam atividade antimicrobiana, analgésica, antifúngica e imunomoduladora. Este estudo teve como objetivo avaliar a atividade antimicrobiana in vitro do extrato metanólico das folhas de L. alnifolia, L. origanoides, L. insignis e L. thymoides frente a microrganismos de importância clínica. Foi realizada uma triagem fitoquímica dos extratos das plantas e a avaliação da atividade antimicrobiana pelo método de difusão em disco, além da determinação da concentração inibitória mínima (MIC) frente às bactérias Bacillus subtilis, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa, Staphylococcus aureus e Salmonella choleraesuis, e os fungos Candida albicans e Candida glabrata. A presença de saponinas, terpenos, esteroides, cumarinas, ácidos fenólicos e flavonoides foi observada na análise fitoquímica. Os extratos metanólicos das folhas de L. alnifolia, L. origanoides e L. insignis apresentaram atividade antimicrobiana contra todas os microrganismos testados. O extrato metanólico da L. thymoides apresentou atividade antimicrobiana frente aos microrganismos M. luteus, P. aeruginosa, S. aureus, C. albicans e C. glabrata. A maioria dos extratos apresentou atividade bacteriostática e todos os extratos apresentaram atividade fungistática para C. albicans e fungicida para C. glabrata. A utilização dos extratos de Lippia pode ser uma alternativa viável no tratamento de doenças infecciosas de origem bacteriana e fúngica.

Leprosy reactions are immune processes that cause neural damage in individuals with leprosy. As periodontitis is an infectious disease related to its development, specific antibodies to periodontal pathogens must be evaluated to better understand the humoral mechanisms underlying this relationship. Therefore, the objective of this study was to standardize an immunoassay to measure IgA specific to P. gingivalis antigens in the saliva of individuals with leprosy. An ELISA checkerboard titration was performed. A validation test involving 53 individuals with leprosy, 24 with and 19 without periodontitis, was conducted and a ROC curve constructed to calculate sensitivity and specificity. The coefficient of the optical densities was 2.21 and 2.66 for P. gingivalis crude extract and the recombinant protein HmuY, respectively. Sensitivity and specificity for the P. gingivalis crude extract were 66.7% and 73.7%, respectively, and for HmuY, were 62.5% and 52.6%, respectively. Specific recognition of P. gingivalis occurred predominantly in individuals with periodontitis, which validates the use of this test for studying periodontitis in individuals with leprosy.Trial registration CAEE 64476117.3.0000.0049, 21/07/2017, retrospectively registered