Sixteen goats either subjected to transport stress or without transport stress were treated with dexamethasone for 3 days prior to infection with P. haemolytica serotype A2 intranasally. The transport-stressed and dexamethasone-treated goats in the first group had various degrees of pulmonary lesions and the organism was re-isolated from the nasal cavity, lymph nodes and lungs. None of the goats treated with dexamethasone only were infected with P. haemolytica and had no lesions of pneumonic pasteurellosis. Treatment with dexamethasone alone failed to induce experimental infection by P. haemolytica except in combination with another stress factor.
Twenty transport-stressed goats were divided into two groups. The first group was further stressed with steroid. Pasteurella haemolytica was found at various sites in the nasal cavity of goats in this group as early as 2 weeks post-transportation. The successful isolations continued consistently with more goats having pure growth of P. haemolytica at later stages. Mild catarrh rhinitis, loss of epithelial cilia and erosions were the main lesions observed in the nasal cavity. Goats in the second group that were not given steroid injections had inconsistent bacterial isolation and less severe pathological lesions.
An experiment was designed to study the in vivo effect of Pasteurella haemolytica A2 infection on the phagocytosis activity of caprine broncho-alveolar macrophages and the extent of pneumonic lesions. Twelve healthy local Kacang goats, about 7 months of age, were divided into two groups of six. Goats in group 1 were inoculated intratracheally with 4 ml inoculum containing 2.8 x 10(9) colony-forming units (CFU)/ml of Staphylococcus aureus. Goats in group 2 were inoculated intratracheally with 4 ml of inoculum containing 9.5 x 10(8) CFU/ml of Pasteurella haemolytica A2 isolated earlier from pneumonic lungs of goat. At intervals of 3 and 7 days post-challenge five goats from each group were killed and the lungs were washed with sterile phosphate-buffered saline. Smears were prepared from the lung washing fluid and the number of macrophages with phagocytic activity was determined. At day 3 post-infection, goats of both groups showed a similar pattern of pneumonic lesion. The lung washing fluid of goats in group 2 was found to contain numerous neutrophils and macrophages. Goats in group 2 showed significantly (P < 0.05) higher extent of lung lesions than group 1. Similarly, the average extent of lung lesions was significantly (P < 0.05) more severe in group 2 at day 7 post-infection. The lung washing fluid contained mostly macrophages. The phagocytic activity following S. aureus infection was more efficient and significantly (P < 0.01) higher compared with infection by P. haemolytica A2. There were weak correlations between the extent of pneumonic lesion and the phagocytic activity. Thus, goats with poor phagocytic activity were likely to develop more extensive lung lesions.
A model of pneumonic pasteurellosis has been established in goats using Pasteurella multocida harvested from pneumonic lungs of goats (types A and D), rabbits (type A) and sheep (type D). The resultant infections were acute, subacute or chronic. The gross and histological lesions of the subacute and chronic infections were typical of pneumonic pasteurellosis. P. multocida type D produced significantly (P < 0.01) more severe lesions when compared with other isolates. There were strong correlations between the clinical signs and the severity of lesions.
Twenty goats of about 7 months of age were divided into five groups. The goats in groups 1 and 2 were exposed once, using an intranasal spray to 2 ml of an inoculum containing 10(6) colony-forming units/ml of living or dead Pasteurella haemolytica A2, respectively. The goats in groups 3 and 4 were similarly exposed twice at a 2-week interval. Group 5 was the untreated control. The number and size of the bronchus-associated lymphoid tissue (BALT) in goats exposed twice to either living or dead organisms were significantly (p < 0.05) increased compared with those exposed once and with the unexposed control. In vitro colonization by living P. haemolytica A2 onto the lung tissue in which the BALT had been stimulated by two exposures of either living or dead organisms was significantly (p < 0.05) reduced. The study indicates that stimulation of the respiratory mucosal immunity may prevent P. haemolytica A2 infection.
Matched MeSH terms: Pasteurellosis, Pneumonic/immunology*; Pasteurellosis, Pneumonic/prevention & control
Mannheimiosis or pneumonic pasteurellosis commonly occurs in small ruminants. Mannheimiosis is caused by Mannheimia haemolytica (M. haemolytica) a Gram-negative coccobacillus producing acute febrile and infectious condition resulting in death of animal if not diagnosed and treated promptly. M. haemolytica serotype A2 is a commensal of the nasopharynx, gaining access to the lungs when host defenses are compromised by stress or infection in small ruminants. Till date, there is a vast literature and research that has been conducted on the pathogenesis of M. haemolytica invariably on respiratory system and its related immune system and mechanisms. From the clinical point of view, infection or diseases involving vital organs will systemically affect the production and performance of the infected animal. Therefore, there is a huge gap of knowledge and research to answer the question whether there is any association between M. haemolytica infection with reproductive physiology and performance in small ruminants and how it affects the productivity level. This review will explore the possibilities of involvement and new potential research to be carried out to determine the involvement of male and female reproductive system with M. haemolytica infection among small ruminants.
Pasteurella multocida causes pneumonic pasteurellosis and hemorrhagic septicemia (HS) in large ruminants. In this study, we determined the complete genome sequence of P. multocida strain PMTB2.1 capsular serotype A isolated from buffaloes that died of septicemia.
The effectiveness of an oil adjuvant vaccine (OAV) incorporating locally isolated strains of Pasteurella haemolytica type 7 and Pasteurella multocida types A and D was compared with that of Carovax (Wellcome Laboratories) in imported cross-bred lambs. The criterion of efficacy was the ability of the vaccines to reduce the extent of pneumonic lesions in vaccinated as against unvaccinated control lambs. The OAV produced at this Institute significantly reduced the lung lesions at P less than 0.05 level compared with its control group when challenged with P. haemolytica alone. However, the vaccine was unsatisfactory against P. multocida or combined P. multocida P. haemolytica challenge. Carovax did not produce any significant reduction in the lung lesions caused by P. haemolytica and/or P. multocida.
The outer membrane proteins (OMP) were extracted from the P. haemolytica A2, A7 and A9 to determine their potential as immunogens and their capability for cross-protection. Sixty lambs of approximately 9 months old were divided into four main groups. Animals in Group 1 were vaccinated with 2ml vaccine containing 100microg/ml of the outer membrane proteins of P. haemolytica A2. Animals in Group 2 were similarly vaccinated with the OMPs of P. haemolytica A7 while Group 3 with OMPs of P. haemolytica A9. Animals in Group 4 were unvaccinated control. During the course of the study, serum was collected to evaluate the antibody levels toward each OMP. There appeared to be good immune responses. However, high antibody levels did not necessarily result in good protection of the animals, particularly against cross-infection with P. haemolytica A9 in animals vaccinated with the OMPs of P. haemolytica A2. It seemed that the antibody responses were more specific toward the homologous challenge but generally did not cross-protect against heterologous serotype challenge. However, the OMPs of P. haemolytica A7 produced good in vivo cross-protection and excellent correlations when good antibody responses against all serotypes led to successful reductions of the extent of lung lesions following homologous and heterologous challenge exposures. Thus, the OMPs of P. haemolytica A7 was effective in protecting animals against homologous and heterologous infection by live P. haemolytica A2, A7 and A9.
Pneumonic pasteurellosis is an economically important infectious disease in the small ruminant industry which causes sudden death and loss for farmers. Nonetheless, this disease is still a common sight in sheep and goats in Malaysia, probably due to the unpopular usage of pasteurellosis vaccine or inappropriate vaccination practices. The aim of this study was designed to classify the severity of pneumonia via the establishment of auscultation scoring method and to quantify the acute phase proteins and heat shock proteins responses from vaccinated and non-vaccinated goats. Goat farms, consist of vaccinated and non-vaccinated farms, were selected in this study: where 15 clinically normal healthy goats and 9 pneumonic goats were selected from vaccinated farms whereas 15 clinically normal healthy goats and 31 pneumonic goats from non-vaccinated farms were selected for this study. Crackle lung sounds were not detected in both vaccinated and non-vaccinated normal goats. However, vaccinated pneumonic goats showed mild crackle lung sound while non-vaccinated pneumonic goats exhibited moderate crackle lung sound. There were significant increases (p
A trial was conducted to observe the immediate and chronic effects in goats of dexamethasone administration on the bronchus-associated lymphoid tissue (BALT) response to intranasal administration of formalin-killed Pasteurella haemolytica A2. Twenty-four goats were divided into four groups. Those in group 1 were injected intramuscularly with 1 mg/kg dexamethasone on three consecutive days, followed by intranasal exposure to formalin-killed P. haemolytica A2 one day after the last dexamethasone treatment. The goats in group 2 were similarly injected with dexamethasone followed by intranasal exposure to formalin-killed P. haemolytica A2 21 days after the last dexamethasone treatment. The animals in group 3 were exposed intranasally to formalin-killed P. haemolytica A2 without prior dexamethasone treatment. The animals in group 4 were untreated controls. The intranasal exposures to formalin-killed P. haemolytica A2 were repeated 2 weeks later. Intranasal exposure to formalin-killed P. haemolytica 1 day after dexamethasone treatment further reduced the number and size of BALT compared to the untreated control. Significantly (p < 0.01) more reduction of BALT occurred in goats exposed to formalin-killed P. haemolytica A2 21 days after dexamethasone treatment. On the other hand, intranasal exposure of goats without prior dexamethasone treatment stimulated the BALT compared to the untreated controls.