Immunization of sheep with a recombinant vaccine containing immunogenic nontoxic domains of Clostridium perfringens alpha and beta toxins.

Clostridium perfringens (types A and C) can cause several diseases by secreting alpha (CPA) and beta (CPB) exotoxins in the gastrointestinal tract. Although vaccination is the main measure of immunization against C. perfringens, available vaccines have limitations in terms of productivity and safety. Thus, recombinant vaccines are an important, more effective, practical, and safer strategy in the immunization of animals. In this study, we evaluated the immunization of sheep with recombinant Escherichia coli bacterins expressing CPA and CPB complete proteins (co-administered), the immunogenic nontoxic domains rCPA-C247-370 and rCPB-C143-311 co-administered or fused as a bivalent chimera (rCPBcAc). For this, in silico analysis was performed to design rCPBcAc, considering the stability of the mRNA (-278.80 kcal/mol), the degree of antigenicity (0.7557), the epitopes of the B cell ligand, and different physicochemical characteristics. All proteins were expressed in vitro. In vivo, animals vaccinated with the co-administered antigens rCPA + rCPB and rCPA-C+ rCPB-C (200 µg each) had mean CPA and CPB neutralizing antitoxin titers of 4, 10, 4.8, and 14.4 IU/mL, respectively, while those vaccinated with 200 µg of rCPBcAc chimera (approximately 100 µg of each antigen) had titers of <4 and 12 IU/mL of CPA and CPB antitoxins, respectively, 56 days after the administration of the first dose. In addition, the chimera was considered to be immunogenic for inducing antitoxin titers using the half dose. In this study, we presented a new recombinant antigen potentially applicable for vaccines against the CPA and CPB toxins for preventing diseases caused by Clostridium perfringens.

Sporotrichosis in dogs: epidemiological and clinical-therapeutic profile and the emergence of itraconazole-resistant isolates.

Sporotrichosis is a neglected and emerging mycosis caused by the traumatic implantation of Sporothrix propagules into the (sub)cutaneous tissues of humans and animals. We evaluated canine sporotrichosis's clinical-therapeutic, epidemiological profile, and in vitro susceptibility of isolates to itraconazole. The variables were evaluated by a chi-square test. A total of 69 dogs were infected with Sporothrix spp., and the molecular identification revealed an overwhelming occurrence of S. brasiliensis as the etiological agent. The epidemiological profile was male (56.5%), adults (4.9 ± 1.92 years old; 69.6%), and mongrels (53.6%). The clinical signs were 76.8%, ulcers, draining tracts, and nodules were predominant, mainly in the nasal region (82.2%). Dogs were diagnosed late with an evolution time of up to 3 months (34.8%). According to the prior therapeutic information, 52.2% received empirical therapy, 79.2% antibiotics, and had a 0.29 significantly greater chance of presenting lesion evolution time ˃ 3 months (P < .05; Odds Ratio [OR] 1/0.29). Additionally, 25 S. brasiliensis isolates recovered between 2006-2012 (n = 15; Minimal inhibitory concentration (MIC): 0.06-2 µg/ml) and 2013-2018 (n = 10; MIC: 2→16 µg/ml) were tested against itraconazole (ITZ). These findings highlighted the resistance to ITZ in clinical cases due to S. brasiliensis occurring after 2013, showing the temporal evolution of ITZ-resistance. We warn of the importance of accurate and early diagnosis in Sporothrix-affected areas, and we report the emergence of ITZ-resistant isolates in Southern Brazil.

Sporotrichosis is a fungal zoonosis. We investigated the clinical-therapeutic, epidemiological profile, and in vitro susceptibility of isolates to itraconazole (ITZ) in canine cases in Southern Brazil. Our study highlighted the emergence of ITZ-resistant Sporothrix brasiliensis and the main challenges for clinical control of this neglected disease.

Probiotic effect of Pichia pastoris X-33 produced in parboiled rice effluent and YPD medium on broiler chickens.

In a previous paper we showed that the yeast Pichia pastoris X-33 grown in parboiled rice effluent supplemented with glycerol byproduct from the biodiesel industry improved the quality of the effluent. In this paper we show the validation of this yeast (PPE) as probiotic for broilers. Its effect on feed efficiency and immunomodulation was compared with the same yeast grown in yeast peptone dextrose medium (PPY), with Saccharomyces boulardii (SBY) and with the controls fed unsupplemented feed (CON). One-day-old female chicks were vaccinated against infectious bursal disease (IBD) and the titers of anti-IBD antibodies were measured by ELISA. PPE group had the highest mean titres on days 14 and 28 (p<0,05), and at 28 days, 64% of the animals showed seroconvertion. The PPE group also showed the best weight gains at 42 days of age, that, on days 7, 14 and 21 were 19%, 15%, and 8.7% higher, respectively, than the control group. The best feed conversion, 8.2% higher than the control group, was obtained by PPY at 42 days. Histopathological studies did not detect any undesirable effects in the supplemented animals. We concluded that Pichia pastoris X-33 when grown in effluents of the rice parboiling industry supplemented with glycerol byproduct from the biodiesel has probiotic properties for poultry.

Bioremediation of parboiled rice effluent supplemented with biodiesel-derived glycerol using Pichia pastoris X-33.

This paper describes the use of Pichia pastoris X-33 as a bioremediator to reduce the chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), and phosphorus (P-PO(4) (3-)), after culture in parboiled rice effluent supplemented with p.a. glycerol or a glycerol by-product of the biodiesel industry. The greatest reduction in the COD (55%), TKN (45%), and P-PO(4) (3-) (52%) of the effluent was observed in cultures of P. pastoris X-33 supplemented with 15 g.L(-1) of biodiesel-derived glycerol. Furthermore, the overall biomass yield was 2.1 g.L(-1). These data suggest that biodiesel-derived glycerol is an efficient carbon source for the bioremediation of parboiled rice effluent and biomass production.

LTB-R1: an alternative to swine mycoplasmal pneumoniae control

Mycoplasmal pneumoniae is the main respiratory disease in swine. The most efficient way to control it is through the use of vaccines (bacterins), whose production cost is high. The objective of this work was to develop a new alternative for controlling Swine Mycoplasmal Pneumoniae, based on a recombinant subunit vaccine containing the R1 region of P97 adhesin of Mycoplasma hyopneumoniae fused to the B subunit of the heat-labile enterotoxin of Escherichia coli (rLTB-R1). In this work we report the amplification of the genes, genetic fusion between LTB and R1 coding sequences, cloning, construction of the expression vector, as well as expression and purification of rLTB-R1 in E. coli.

A Pneumonia Micoplásmica é a doença respiratória mais importante dos suínos. A forma mais eficaz de controlá-la é mediante a utilização de vacinas (bacterinas), cujo custo de produção é elevado. Uma nova alternativa para o controle desta doença, baseada em uma vacina de subunidade recombinante contendo a região R1 da adesina P97 de Mycoplasma hyopneumoniae fusionada a subunidade B da enterotoxina termolábel de Escherichia coli (rLTB-R1), foi o alvo deste trabalho. Nele abordou-se a amplificação dos genes, a fusão genética entre as seqüências codificadoras para LTB e R1, a clonagem, a construção do vetor de expressão, assim como a expressão em E. coli e purificação da rLTBR1.

Effect of the Kozak sequence on seroconversion of mice immunized with a DNA vaccine against swine colibacilosis

The neonatal diarrhea in swine caused by enterotoxigenic Escherichia coli (ETEC) is responsible for high mortality and low growth rate in pigs and it is mainly dependent on the capacity of E. coli to attach to the surface of the small intestine, a property mediated by fimbria. In this study the faeC gene, which codes for the minor fimbrial subunit of E. coli K88ab, was cloned in the eukaryotic expression vector pcDNA3, associated or not to the Kozak sequence. Plasmid DNA of the two versions of the vaccine candidate was inoculated in mice by the intramuscular route, in two doses, at 0 and 21 days. The animals that received the DNA vaccine containing faeC associated to the Kozak sequence presented seroconversion significantly higher (P 0.05) than the one vaccinated with pcDNA3/faeC without the Kozak sequence.

A diarréia neonatal em suínos causada por Escherichia coli produtora de enterotoxinas (ETEC) é responsável por alta mortalidade e baixa taxa de crescimento de leitões. A habilidade de tais cepas causar doença é dependente principalmente da capacidade de E. coli aderir-se a mucosa do intestino delgado, que é mediada por fímbrias. Neste estudo o gene faeC, que codifica a subunidade menor da fímbria de E. coli K88ab, foi clonado no vetor de expressão em eucariotos pcDNA3, associado ou não à seqüência de KozaK. DNA plasmidial das duas versões da vacina foi inoculado em camundongos via intra-muscular, em duas doses, nos dias 0 e 21. Os animais que receberam a vacina de DNA contendo o faeC associado a seqüência de Kozak apresentaram soroconversões significativamente maiores (p 0,05) que os vacinados com pcDNA3/faeC sem a seqüência de Kozak.