ABSTRACT
Three recombinant outer membrane proteins (rOmps) from the Haemophilus parasuis Nagasaki strain (serovar 5 reference strain), rOmpP2, rOmpP5 and rOmpD15, which have previously shown protection against H. parasuis infection in mice, were cloned, expressed and evaluated as vaccine antigens in colostrum-deprived pigs. When these animals were immunized with these rOmps and were later challenged intratracheally with 108 CFUs of the Nagasaki strain, no protection was seen in terms of survival, clinical signs, pathological results and recovery of H. parasuis. We hypothesized that a possible explanation for this lack of protection could be the low number of epitopes accessible to the immune system as a consequence of their poor exposure on the bacterial surface so that the immune response would not be able to protect against experimental infection by H. parasuis when a fully susceptible animal model, such as pigs, was used.
Subject(s)
Haemophilus Infections/veterinary , Haemophilus Vaccines/immunology , Haemophilus parasuis/immunology , Swine Diseases/immunology , Animals , Antibodies, Bacterial , Colostrum , Female , Haemophilus Infections/immunology , Haemophilus Infections/prevention & control , Mice , Pregnancy , Swine , Swine Diseases/prevention & controlABSTRACT
ABSTRACT The efficacy of 28 individual or blended disinfectants against avian Salmonella enterica serovar Enteritidis and Escherichia coli strains was determined. An in vitro test in the presence and absence of serum as source of organic material was conducted. Povidone-iodine (releasing 1% available iodine), 1% potassium permanganate, 70% ethanol, 2% chlorhexidine digluconate and three commercial formulations based on quaternary ammonium compounds + formaldehyde or cresol derivates were the most effective against all strains tested and reduced bacterial counts by more than 106 times (6-log10) regardless of the presence of organic matter. These commercial compounds as well as ethanol and chlorhexidine among the individual substances tested might be helpful in the adoption of environmental control measures against these two enterobacteria in poultry industry.
RESUMO: A eficácia de 28 desinfetantes individuais ou combinados sobre cepas de Salmonella enterica serovar Enteritidis e Escherichia coli foi determinada. Um teste in vitro em presença e ausência de soro como fonte de matéria orgânica foi realizado. Iodopovidona (contendo 1% de iodo ativo), permanganato de potássio a 1%, etanol a 70%, digliconato de clorexidina e três formulações comerciais, baseadas em compostos de amônia quaternária + formaldeído ou em derivados de cresóis, foram mais eficazes contra as cepas bacterianas testadas, reduzindo em mais 106 vezes (6-log) a contagem bacteriana, independente da presença de matéria orgânica. Esses compostos comerciais, bem como o etanol e a clorexidina entre as substâncias químicas individuais avaliadas, podem ser úteis para a implementação de medidas de controle ambiental contra estas duas enterobacterias de importância para a indústria aviária.
