Severe infection caused by nymphs of Armillifer armillatus (Pentastomida, Porocephalidae) in a leopard, Panthera pardus, in the Kruger National Park, South Africa.

The necropsy of an adult male leopard, Panthera pardus, shot in the Kruger National Park, revealed the presence of large numbers of Armillifer armillatus nymphs in the intestine, liver, spleen, mesentery, peritoneal fold, mediastinum and lungs. The animal had been observed to be blind in the right eye and severely debilitated. The infection with A. armillatus clearly contributed to its emaciation and anaemia. Armillifer armillatus is a parasite of snakes, using mammals that form part of the snakes' prey as intermediate hosts. It is also one of the pentastomids with the highest zoonotic potential in Africa. It is unclear if the leopard's partial blindness and injuries of its extremities forced it to forego larger prey items for easier prey, such as snakes, and this in turn led to exposure to this unusual parasite, or if he had simply developed a preference for snakes. The incidental finding of A. armillatus in a large carnivore emphasises the importance of necropsies in expanding our knowledge on wildlife diseases.

Host-specific phenotypic variation of a parasite co-introduced with invasive Burmese pythons.

Invasive Burmese pythons (Python bivittatus Kuhl, 1820) have introduced a lung parasite, Raillietiella orientalis, (Hett, 1915) from the python's native range in Southeast Asia to its introduced range in Florida, where parasite spillover from pythons to two families and eight genera of native snakes has occurred. Because these novel host species present a diversity of ecological and morphological traits, and because these parasites attach to their hosts with hooks located on their cephalothorax, we predicted that R. orientalis would exhibit substantial, host-associated phenotypic plasticity in cephalothorax shape. Indeed, geometric morphometric analyses of 39 parasites from five host species revealed significant variation among host taxa in R. orientalis cephalothorax shape. We observed differences associated with host ecology, where parasites from semi-aquatic and aquatic snakes exhibited the greatest morphological similarity. Morphological analyses of R. orientalis recovered from invasive pythons, native pit vipers, and terrestrial snakes each revealed distinct shapes. Our results suggest R. orientalis can exhibit significant differences in morphology based upon host species infected, and this plasticity may facilitate infection with this non-native parasite in a wide array of novel squamate host species.

Preliminary report of histopathology associated with infection with tongue worms in Australian dogs and cattle.

Tongue worms utilise herbivorous mammals as intermediate hosts and reside in the nasopharynx of carnivores as their definitive hosts. A recent study in south eastern Australia showed an unexpectedly high infection (67%) of wild dogs with these parasites. The present study aimed at determining the pathogenicity of the parasite in both definitive (dog) and intermediate (cattle) hosts by histopathology. The definitive host showed multifocal haemorrhage of the interstitium of the nasal mucosa, multifocal mucosal erosion, congestion and haemorrhage, with haemosiderin laden macrophages present in those foci and distortion and destruction of the nasal mucosa. Histopathologic examination of lymph nodes from an infected cow showed diffuse eosinophilic granulomatous necrotising lymphadenitis and perinodal panniculitis with intralesional parasitic remnants and comparatively large numbers of eosinophils. A large, ~300-500 µm diameter, area of necrosis was also observed in one lymph node. This is the first time a study has been undertaken in Australia to determine the pathogenicity of tongue worms in both their definitive and intermediate hosts. This is a preliminary study and to properly estimate the health impact of infection with this pathogenic parasites on Australian production and companion animals more studies are necessary.

Infection rates of Linguatula serrata nymphs in mesenteric lymph nodes from water buffaloes in North India.

The literature pertaining to prevalence of Linguatula serrata in large ruminants is limited. In abattoir survey, the infection rate of L. serrata in 1440 mesenteric lymph nodes collected from 480 buffaloes from North India was investigated. Results revealed 88 (18.3%) buffaloes and 288 (20.0%) mesenteric lymph nodes having parasite's nymphs. Nonsignificant difference (P>0.05), between 1 and 3 years age (51.5%) and above three years of age (48.5%) groups was observed. Nonsignificant difference (P>0.05) between the infection rate of male (51.5%) and female (48.5%) was also observed. Infection in haemorrhagic (57.2%) and black-coloured (67.5%) nymph nodes were significantly (P<0.05) higher than normal-coloured nodes (8.8%). When compared based on consistency, the results showed soft lymph nodes (61.3%) were significantly (P<0.05) more infected than normal (12.8%) and hard (30.0%) lymph nodes. The intensity of infection in normal, haemorrhagic and black lymph nodes were 1.81 ± 0.21, 4.23 ± 0.0.62 and 5.12 ± 0.73, nymphs respectively. The mean numbers of parasites in haemorrhagic and black-coloured lymph nodes were significantly (P<0.0005) more than mean number of parasites in normal-coloured nodes. Again intensity of infection in normal, soft and hard lymph nodes was 2.31 ± 0.18, 5.84 ± 0.74 and 3.21 ± 0.68, respectively. When compared based on lymph nodes consistency, the soft lymph nodes were significantly (P<0.0005) more severely infected than normal and hard ones. The study has generated some vital data about the prevalence of this underreported disease amongst the bubaline intermediate hosts along with important gross changes in the affected lymph nodes.

Multi-host model-based identification of Armillifer agkistrodontis (Pentastomida), a new zoonotic parasite from China.

BACKGROUND: Pentastomiasis is a rare parasitic infection of humans. Pentastomids are dioecious obligate parasites requiring multiple hosts to complete their lifecycle. Despite their worm-like appearance, they are commonly placed into a separate sub-class of the subphylum Crustacea, phylum Arthropoda. However, their systematic position is not uncontested and historically, they have been considered as a separate phylum. METHODOLOGY/PRINCIPAL FINDINGS: An appraisal of Armillifer agkistrodontis was performed in terms of morphology and genetic identification after its lifecycle had been established in a multi-host model, i.e., mice and rats as intermediate hosts, and snakes (Agkistrodon acutus and Python molurus) as definitive hosts. Different stages of the parasite, including eggs, larvae and adults, were isolated and examined morphologically using light and electron microscopes. Phylogenetic and cluster analysis were also undertaken, focusing on the 18S rRNA and the Cox1 gene. The time for lifecycle completion was about 14 months, including 4 months for the development of eggs to infectious larvae in the intermediate host and 10 months for infectious larvae to mature in the final host. The main morphological difference between A. armillatus and Linguatula serrata is the number of abdominal annuli. Based on the 18S rRNA sequence, the shortest hereditary distance was found between A. agkistrodontis and Raillietiella spp. The highest degree of homology in the Cox 1 nucleic acid sequences and predicted amino acid sequences was found between A. agkistrodontis and A. armillatus. CONCLUSION: This is the first time that a multi-host model of the entire lifecycle of A. agkistrodontis has been established. Morphologic and genetic analyses supported the notion that pentastomids should be placed into the phylum Arthropoda.