Pasteurella multocida-associated septicaemia in a chital deer (Axis axis)

Zoonotic diseases appeared to be a major hurdle to successful deer farming in Bangladesh

Background and Aim

Due to the diversified lifestyle and fancy ecology associated with Chitra deer (Axis axis), deer farming has become popular in Bangladesh. Diseases may be the common constrain of successful deer farming. This study aims to investigate the pathological, bacteriological, and nucleic acid based technologies to identify specific causes of morbidity and mortality of captive deer.

Materials and Methods

Two deer farms and a park deer (designated as farm A, B, and C) entailing 87, 54, and 20 deer, respectively, showed illness and death constitute the study materials. A total of 42 deer died during this investigation. Following death, routine post-mortem examination, histopathology, impression smear staining, isolation, and identification of bacteria were carried out. Polymerase chain reaction (PCR) and reverse transcription PCR were carried out to safeguard the etiology.

Results

Clinically, farm A and B showed the acute phase of illness and park deer showed chronic illness. Case fatality rates were 90%, 92%, and 100% in farms A, B, and C deer, respectively. Pasteurella multocida and Streptococcus pneumoniae were identified from the visceral organs of farm A deer. Farm B deer was infected with Clostridium perfringens type A. Park deer was infected with Mycobacterium tuberculosis and hydatid cyst.

Conclusion

The infectivity in farm A deer was due to stress as induced by punishing weather. The infectivity in farm B deer was due to feeding a higher volume of protein in the diet. The park C deer may optate infection from companion man and animals living around. The diseases of captive deer identified mainly were zoonotic. It needs extensive veterinary services and specialized technologies to identify these diseases, monitor the infectivity and eliminate the public health important diseases at early onset.

Biological characterization of Pasteurella multocida present in the Saiga population

Background

This study provides biochemical and molecular genetic characteristics of P. multocida isolated from dead saigas in 1988, 2010–2015 on the territory of the Republic of Kazakhstan.

Results

Bacteriological samples taken from carcasses of saiga antelope during mortality events recorded in West Kazakhstan in both 2010 and 2011 and in Kostanay in 2012 and 2015 confirmed the presence of P. multocida, according to morphological and biochemical characterisation. Only in the event of 2015 was the agent proven to be the causative agent of the disease observed, haemorrhagic septicaemia. In the other mortality events it is not certain if the organism was a primary aetiology or an incidental finding as confirmatory pathological investigation was not undertaken. The implemented phylogenetic analysis of ribosomal RNA 16S gene allowed us to identify Pasteurella strains isolated in 2010–2015 as P. multocida subspecies multocida. Capsular typing by PCR showed that the studied strains isolated from dead saiga in 2010, 2011, 2012 and 2015 belonged to serotype B. MLST analysis showed that these strains of P. multocida are of the capsule type B and form one clonal grouping with isolates ST64, ST44, ST45, ST46, ST44, ST47 which isolated from cases of hemorrhagic septicemia of animals in Hungary, Burma, Sri Lanka, Pakistan and Spain. Sixteen virulence genes of the five strains of P. multocida, isolated from saigas were studied using multiplex PCR. ptfA, ompA, ompH, oma87, plpB, fimA, hsf-2, pfhA, exbB, tonB, hgbA, fur, nanB, nanH and pmHAS genes were detected in all strains. The toxA gene was not identified in the studied strains. The phylogenies of these isolates is compared across saiga populations and years and the 2015 isolate was compared to that of an isolate from a disease outbreak in 1988 and the findings suggest that these isolated bacteria are stable commensals, opportunistically pathogenic, being phylogenetically uniform with very little genetic variation notable over the last 4 decades.

Conclusion

Isolation, phenotypic and genetic characterization of the P. multocida isolates inform understanding of the epidemiology of infection in saigas and predict virulent potential of these opportunistic bacteria.