Studies On Haemorrhagic Septicaemia In Cattle And Buffaloes In Peninsular Malaysia

Haemorrhagic septicaemia is an acute septicaemic disease caused by Pasteurella multocida types 6:B and 6:E. It affects mainly cattle and buffaloes and is characterised by a rapid course, loud stertorous breathing, oedematous swelling and petechial haemorrhages in the throat and brisket region. The disease is responsible for acute deaths causing severe economic losses to the farmers. Haemorrhagic septicaemia has long been present in the country and many attempts have been made to understand and control the disease. Currently, despite prophylactic vaccination, outbreaks of the disease continued to be reported. A review of the literature on HS indicates that there are gaps in our understanding of the disease in Malaysia. A retrospective study using questionnaires sent to all District Veterinary Officers showed that the disease is endemic in the East Coast states of Peninsular Malaysia (Kelantan, Terengganu and Pahang). The disease was observed to occur at any time of the year, contrary to the long-held belief that HS occurs during the monsoon season. Although the incidence can be higher during rainy seasons, the time series studies showed that rain per se did not influence the frequency of the disease. Six major outbreaks were investigated in the states of Perak, Melaka, Negeri Sembilan, Johor, Terengganu and Kelantan. Field and experimental observations suggest that buffaloes are more susceptible than cattle to the disease

Phenotypic characterisation of Pasteurella multocida obtained from poultry in Iran

Phenotypic patterns of twenty-five isolates of P. multocida strains isolated from northern provinces of Iran were determined by using different carbohydrates from hexoses, pentoses, disaccharides and polyhydric alcohols. The strains showed a high homogeneity. All strains were able to ferment sorbitol, mannitol, galactose, dextrose, fructose, glucose, mannose and sucrose. However none of them could produce acid from dulcitol, inositol, arabinose, salicine, raffinose and inoline. According to this pattern all of isolates belonged to subspecies multocida. The in-vitro sensitivity of isolates against 13 chemotherapeutic agents was determined by the paper disc method. Among the antibiotics tested, chloramphenicol, combination of sulfamethoxazine and trimethoprim and nitrofurantoin were found to be the most effective (100%) followed by tetracycline (96%), penicillin (88%), and gentamicin (76%). Strains showed 100% resistance to lincomycin and bacitracin followed by 84% and 68% resistance to furazolidone and colistin respectively. All P. multocida isolates identified as to capsular type A

Immuno-pathophysiological responses of mouse model to experimental infection with Brucella melitensis and its lipopolysaccharides via intraperitoneal route

Brucella melitensis is one of the major zoonotic pathogens with significant economic implications worldwide. The pathogenicity is complex and not always well understood. Lipopolysaccharide (LPS) remains the major virulent factor of B. melitensis and responsible for the mechanism by which the pathogen causes its deleterious effects. In this study, 84 mice of 6–8 weeks old of both sexes were divided equally into 3 groups; namely Brucella melitensis infected group, lipopolysaccharide (LPS) infected group and control group. The former two groups contained 36 mice each with equal gender distribution. The control group consisted of 12 mice only. Animals in B. melitensis infected group, a single inoculum of 0.4 ml containing 109 of B. melitensis were intraperitoneally challenged while animals in LPS group, a single dose of 0.4 ml containing LPS extracted from the B. melitensis were intraperitoneally inoculated. Animals in control group received intraperitoneally, a single dose of 0.4 ml phosphate buffered saline (PBS) of pH7. Animals that were infected intraperitoneally with B. melitensis demonstrated significant clinical presentation; gross and histo-pathological evidence than LPS infected group. However, both infected groups showed elevated levels of interleukins (IL-1β and IL6), antibody levels (IgM an IgG) as early as 3 days post-infection with predominance in LPS infected group. In contrast, low levels of sex related hormonal changes in which LPS infected group showed the least concentration were also detected throughout the experimental period. In conclusion, B. melitensis can be transmitted via gastrointestinal, respiratory and reproductive tract. Moreover, LPS stimulated significantly the innate and acquired immune system without significant systemic dysfunction, suggesting potentiality of the protective properties of this component as alternative vaccine for brucellosis infection

Herd immunity in buffaloes after intranasal live gdhA derivative P. multocida B:2 vaccine

The results of a live attenuated gdhA derivative P. multocida B:2 vaccine on immunity in buffalo herds is described. Three groups of 30 to 50 buffaloes selected from a haemorrhagic septicaemia-endemic and non-endemic area were used. Thirty percent of animals in each group were given intranasal 5 ml inoculum 106 cfu/mL live attenuated gdhA derivative P. multocida B:2. After exposure, vaccinated buffaloes were mingled with non-vaccinated animals of the same group. A booster dose was given 10 months after the first exposure. Serum samples were randomly collected from 30% of each group before vaccination and at 2-month intervals for 22 months to determine herd immune status by ELISA. Endemic or non-endemic herd status was compared with 15 non-vaccinated controls. Results revealed high herd antibody levels in endemic and non-endemic areas before vaccination. After vaccination, herd antibody levels in both areas gradually increased to peak values by the 6th month and then started to gradually decline until month 10. Following booster dose at 10th month, antibodies declined to levels similar to those in unvaccinated animal at 12 to 14 months. Antibody levels then recovered at 22-months (end of study). It was concluded that field vaccination using gdhA derivative P. multocida B:2 increased herd immunity for 8 to 10 months before a booster dose was required

Pathological changes in the organs of mice model inoculated with Corynebacterium pseudotuberculosis organism

Corynebacterium pseudotuberculosis is a facultative, gram positive intracellular small club-shaped rod which produces lesions similar to those of tuberculosis. It is known worldwide to cause caseous lymphadenitis (CLA) in sheep and goats. CLA is characterized by the abscess formation in lymph nodes and/or visceral organs. In the recent outbreak of CLA in the TPU farm in UPM, it was reported that the CLA lesions were found in the visceral organs. In the present investigation, attempts were made to study the ethiopathogenesis of CLA in mice models which involved a comparison of clinical signs, haemogram and biochemistry, and histopathological changes in visceral organs between the diseased and non-diseased group. As an overall summary of this project, CLA in mice resulted in clinical signs, such as huddling together, dejection, anorexia, pasty faeces and accompanied by a rapid and shallow respiration pattern. For the haemogram and serum biochemistry profile, it showed a significant difference in the mean value between the diseased group and non-diseased group which include lymphocyte, plasma protein, monocyte, eosinophil, total bilirubin, total protein and potassium. Finally, the most pronounced histopathological changes in the visceral organs were septicaemia, with severe congestion and increased vascularization, together with the presence of capsulated abscess, micro-abscesses formation, infiltration of neutrophils and macrophages, tubercule granulomas, necrosis and early signs of degeneration in majority of the infected mice

Fatal melioidosis in a captive elephant trunk snake (Acrochordus javanicus) in Kuala Lumpur, Malaysia

An adult female Elephant Trunk Snake (Acrochordus javanicus) was reported to have been weak and inappetent for five days. The following morning the snake found dead, while in the process of shedding its skin. On post mortem examination, there were multiple circumscribed caseous nodules of various sizes distributed all over the liver, along the respiratory tract and on the lungs. Bacteriological analysis of the lungs and liver swab samples yielded Burkholderia pseudomallei, which was confirmed by PCR amplification of specific 16S rRNA. The condition was diagnosed as melioidosis and the organism was genotypically characterized as sequence type 51, a genotype that has been previously characterized in humans in Malaysia. Antibiotic susceptibility by both Disc diffusion or Kirby Bauer and E-test minimum inhibitory concentration (MIC) showed that the organism exhibited susceptibility to meropenem, imipenem, ceftazidime, cotrimoxazole and co-amoxyclav; the antibiotics recommended in the treatment of melioidosis