Hemorrhagic Septicemia In Cattle Research Articles

Identification of genes transcribed by Pasteurella multocida in rabbit livers through the selective capture of transcribed sequences

Pasteurella multocida, a Gram-negative nonmotile coccobacillus, is the causative agent of fowl cholera in poultry, hemorrhagic septicemia in cattle, atropic rhinitis in swine, and snuffles in rabbits. The differentially expressed gene profile of P.multocida in infected rabbit livers was identified and compared with that from in vitro culture by selective capture of transcribed sequences. A total of 31 genes were identified, of which 28 encoded enzymes for amino acid biosynthesis and metabolism, intermediary metabolism, and energy metabolism, or proteins for regulatory adaptive responses, general microbial stress response, transport proteins, and secreted proteinases. Three were unknown, novel genes. Five genes representing different categories were chosen randomly and verified by real-time reverse transcriptase-polymerase chain reaction analysis. All were upregulated by P.multocida in infected rabbit livers, with changes ranging from 1.61- to 13.55-fold when compared with in vitro cultures. This study has identified genes of P.multocida that are upregulated during infection of rabbit livers when compared with in vitro growth conditions. The genes will provide a molecular basis for further study of the pathogenesis of P.multocida.

A review of hemorrhagic septicemia in cattle and buffalo

Hemorrhagic septicemia (HS), an acute, fatal and septicemic disease of cattle and buffaloes caused by Pasteurella multocida, is important in tropical regions of the world, especially in African and Asian countries. The prevalence of disease has been well documented with predominant isolation of P. multocida serotypes B:2 and E:2. Conventional methods of identification such as serotyping, biotyping, antibiogram determination and pathogenicity as well as molecular methods (P. multocida-specific polymerase chain reaction (PCR), a serogroup B-specific PCR assay, multiplex capsular typing system and loop-mediated isothermal amplification techniques) and characterization (restriction endonuclease analysis, randomly amplified polymorphic DNA analysis, repetitive extragenic palidromic PCR and enterobacterial repetitive intergenic consensus PCR analysis) are applied in parallel for rapid epidemiological investigations of HS outbreaks. Although several vaccine formulations including alum precipitated, oil adjuvant and multiple emulsion vaccines are commercially available, the quest for suitable broadly protective HS vaccines with long-lasting immunity is on the upsurge. Concurrently, attempts are being made to unravel the mysteries of the pathogen and its virulence factors, pathogenesis and determinants of protective immunity as well as diversity among strains of P. multocida. This review highlights the advances in these various aspects of HS.

Haemolytic and cytotoxic activities of the Tween 80-extracted putative haemolysin of Pasteurella multocida B:2

The objective of this study was to investigate the haemolytic and cytotoxic activity of Pasteurella multocida B:2 strains, originally from cases of haemorrhagic septicaemia in cattle. All six P. multocida B:2 strains were non-haemolytic on sheep blood agar (SBA) and horse blood agar (HBA) when grown aerobically and on SBA anaerobically but they were haemolytic on HBA when grown anaerobically. No haemolytic activity against horse red blood cells was detected in culture supernates from aerobically or anaerobically grown cultures and only very weak haemolytic activity was obtained in supernates or pellet fractions from sonicated cells. However, after repeated extraction of sonicated cells with Tween 80, haemolytic activity was found in various cell fractions, both Tween-soluble and -insoluble. The Tween-extracted putative haemolysin and other bacterial fractions were also cytotoxic for mouse macrophage-like J774.2 cells. Further characterisation of the putative haemolysin revealed it to be a heat-labile, non-pore-forming protein of molecular weight >10kDa whose activity was completely destroyed by trypsin and greatly reduced with protease and proteinase K treatment. Congo red also reduced the haemolytic activity. Non-denaturing gel-electrophoresis and RBC agar overlay revealed clear haemolytic zones but suggested that Tween was bound to some component of the P. multocida B:2 fractions and was responsible, to some extent, for the haemolytic activity observed. However, the effect of heat and other reagents on the Tween-extracted fractions and the lack of haemolytic activity in different Tween-extracted cell fractions of organisms other than P. multocida suggested that some proteinaceous component of the organism could indeed act as a haemolysin. This putative haemolysin may be one of the virulence attributes of P. multocida, but its characterisation and role in pathogenesis require further study.

Mechanisms of bacterial pathogenesis in respiratory processes: pasteurellosis

Pasteurella multocida is a multispecies pathogen that causes serious diseases in wild and laboratory animals and in human beings. This bacteria is the etiologic agent of diseases such as fowl cholera in chicken and turkey, hemorrhagic septicemia in cattle, athrofic rhinitis in swine and infections in humans by cat and dog bites. This agent is responsible for annual losses of hundreds of millions of dollars in animal production, only in United States. In the rabbit P. multocida can be a virulent fatal pathogen inducing septicemia, pneumonia, chronic rhinitis, otitis as well as abscesses. In this species a respiratory syn-drome appears in which frequently Bortetella bronchi-septica is also isolated. However the role of each of these bacteria or some of their virulence factors, like LPS, in the induction of the disease has not been determined. P. multocida is a Gram negative cocobacilo with several identified virulence factors, like capsule, sialidasa, fila-mentous hemagglutinin, flagelum, neuraminidasa, some porins, dermonecrotic toxin, termolabil toxin (PMT), outer membrane proteins (OMP) and LPS. The lack of effective prevention and control of this type of diseases makes a research of the pathogenesis of the bacteria and its interactions with the host necessary.

Cloning and characterisation of theahpagene ofPasteurella multocidaserogroup b:2 (strain p52): Short communication

Pasteurella multocida B:2 is responsible for haemorrhagic septicaemia in cattle and buffaloes, causing severe economic losses in the developing countries. In the present study, the ahpA gene of P. multocida B:2 (P52) was cloned, sequenced and compared with the previously reported ahpA gene sequence in P. multocida A:1, which is responsible for its haemolytic phenotype. E. coli DH5a cells were further transformed with recombinant plasmid carrying the ahpA gene from P. multocida B:2 (P52) but SDS-PAGE analysis failed to show the expression of haemolysin protein. Slight haemolysis was albeit observed in horse blood agar plates streaked with recombinant E. coli carrying the ahpA gene. Our study indicates that there is 99.6% similarity and 0.4% divergence between ahpA gene of P. multocida B:2 (P52) and P. multocida A: 1, while membrane topology analysis has predicted that ahpA is an inner membrane protein with two strong hydrophobic regions at the N and C terminals. The presence of significant homology in ahpA sequence in A: 1 and B:2 perhaps suggests a common mechanism of pathogenesis in different species of animals.

A Case of pasteurella multocida pleural empyema

Pasteurella multocida, a Gram-negative coccobacillus, is part of the normal oral flora of many types of animals, including domestic dogs and cats. It is the etiologic agent of a variety of infectious diseases, such as hemorrhagic septicemia in cattle or fowl cholera in chicken. Although this is a primary pathogen in the animal world, infection due to Pasteurella multocida in man has been described with increasing frequency recently. The majority of individuals with Pasteurella multocida pulmonary infection possess some underlying pulmonary diseases, most commonly bronchiectasis or COPD. With a review of literature, We report a young man who developed the empyema caused by Pasteurella multocida.

Development of a PCR test based on a gene region associated with the pathogenicity of Pasteurella multocida serotype B:2, the causal agent of Haemorrhagic Septicaemia in Asia

We have developed a PCR assay to detect Pasteurella multocida serotype B:2, the causal agent of Haemorrhagic Septicaemia (HS) in Asia. Nucleotide sequence determination of a 16S rRNA–23S rRNA PCR product unique to B:2 strains was shown to share amino acid sequence homology with a bacteriophage Mu protein. Primers designed from this sequence when tested against a panel of isolates recovered from a wide geographical area and representing a large range of bacterial genera and species, were found to specifically amplify DNA from P. multocida, serotype B:2. Southern hybridisation confirmed the presence of this sequence in only the B:2 serotype of P. multocida, suggesting an association between bacterial virulence and the presence of bacteriophage genes in the bacterial genome. The results of this study demonstrate the potential application of PCR to the diagnosis of HS in cattle and buffalo in Asia. Application of PCR to support diagnosis of HS will greatly improve accuracy, laboratory response time, and will facilitate rational deployment of resources for controlling this disease.

Passive immune cross-protection in mice produced by rabbit antisera against different serotypes of Pasteurella multocida

Haemorrhagic septicaemia (HS) and fowl cholera (FC) are specific diseases caused by certain serotypes of Pasteurella multocida. Strains that usually cause HS in cattle and water buffalo do not produce FC in avian species, and strains that cause FC do not produce HS in cattle and water buffalo. A variety of P. multocida serotypes, including unusual strains which can cause HS in wild ruminants, were evaluated in passive immune protection studies to determine the immunological relationship between strains associated with HS and FC. Various degrees of cross-protection were seen among the strains. Antiserum against a serotype B:3,4 strain protected against strains capable of causing HS (serotypes B:1, B:2, B:3,4, B:4 and E:2) and FC (serotypes A:1, A:3 and A:5). Antiserum against an FC strain (serotype A:5) similarly protected against strains capable of causing HS and FC. Antigenic analyses indicated that cross-protection was not necessarily induced by serotype-specific capsular (beta) or somatic (gamma) antigens or major porin protein. SDS-PAGE and immunoblots of whole cell lysates of the different HS and FC strains showed many protein-staining bands with similar mobilities and antigenic activity. These cross-reactive antigenic bands occurred in the 20- to 120-kDa range. Adsorption of antiserum with a heterologous serotype removed its reactivity with most of these bands, as well as its ability to cross-protect.

Pasteurella multocida infections in mice with reference to haemorrhagic septicaemia in cattle and buffalo

Haemorrhagic septicaemia (HS) is an infectious disease of cattle and buffalo caused by particular serotypes of Pasteurella multocida and is one of the most economically important livestock diseases in South-East Asia. While HS has been recognized for many years, very little is understood about the disease, primarily because of the expense of cattle and a lack of suitable animal models. The suitability of using mice to study HS was assessed using parameters such as the critical pathogenic dose, kinetics of infection, pathology of disease and resistance to reinfection. Pasteurella multocida M1404, the type strain for Carter group B, the serotype responsible for Asian HS, was injected intraperitoneally into BALB/c mice. As few as 20 colony forming units produced an overwhelming septicaemia in mice in less than 30 h. The kinetics of infection demonstrated a very rapid in vivo multiplication rate. There was no evidence of inhibition of bacterial cell growth by natural host defence mechanisms, even with the very small inocula used. The gross pathology of the disease in mice was characterized by splenomegaly, lymphadenopathy and petechial haemorrhages similar to that observed in cattle and buffalo with HS. Mice were found to develop a short-lived resistance to reinfection following a primary infection which had been successfully treated with antibiotics. The mouse would seem to provide an ideal tool by which to study HS, but warrant further studies in order to be able to critically assess it as a model for this economically important disease.

Haemorrhagic septicaemia in cattle and buffaloes

Haemorrhagic septicaemia in cattle and buffaloes