Theileria orientalis outbreak in an organized cattle breeding farm

Acute Respiratory Syndrome Mimicking Shipping Sickness in Theileria buffeli Infected Buffalo Calf

Benign theileriosis, caused by the members of the Theileria orientalis complex, can develop fatal clinical outbreaks characterized by acute respiratory manifestation in stressful conditions. This report describes the molecular diagnosis and clinical management of a recently transported buffalo calf with severe Theileria buffeli infection and associated acute pneumonia. A five-month-old male buffalo calf having an inter-state travel history three days back was presented with pyrexia, anorexia, weakness, mucoid rhinorrhoea, dyspnoea and diarrhoea from the day of procurement. The history and physical examination revealed a clinical presentation similar to shipping fever. Whereas, severe parasitemia of Theileria spp. with anaemia, thrombocytopenia and granulopenia were evident on laboratory investigation. The Theileria spp. infection was confirmed by PCR method using specific primers and the authentication was made by detailed sequence analysis. The small subunit rRNA was amplified using universal apicomplexan primers and the phylogenetic analysis was carried out for further characterisation. The animal was stabilized by steroid nebulization therapy and the specific chemotherapy was instigated using buparvaquone and sulphamethoxazole-trimethoprim combination. Supportive medications like non-steroidal anti-inflammatory drugs, antihistamines, antidiarrhoeals and vitamins were provided symptomatically. The animal showed a good response to therapy and recovered from parasitemia by day 10 and the molecular clearance was later confirmed on day 70 of therapy. The present case of Theileria buffeli infected buffalo calf with acute respiratory signs points towards the possible hemoparasitic outbreaks in transport-stressed animals with the signs of shipping fever-associated syndrome.

Multiplex PCR for rapid differential diagnosis of co-prevalent species of Theileria (Theileria annulata and Theileria orientalis) in cattle

Theileriosis is a tick-borne disease that causes enormous losses in the dairy industry. There are several species of Theileria that can infect bovines. Generally, more than one species are prevalent in any geographical area; thus, chances of co-infections are high. Differentiation of these species may not be possible by microscopic examination or serological tests. Therefore, in this study, a multiplex PCR assay was standardized and evaluated for rapid and simultaneous differential detection of two species of Theileria viz., Theileria annulata and Theileria orientalis. Species-specific primers were designed to target the merozoite piroplasm surface antigen gene (TAMS1) of T. annulata and the major piroplasm surface protein gene of T. orientalis, yielding specific amplicon of 229 bp and 466 bp, respectively. The sensitivity of multiplex PCR was 10² and 10³ copies for T. annulata and T. orientalis, respectively. The simplex and multiplex PCRs were specific and showed no cross-reactivity with other hemoprotozoa for either primer. For comparative evaluation, blood samples from 216 cattle were tested by simplex and multiplex PCR for both species. Using multiplex PCR, 131 animals were found infected for theileriosis, of which 112 were infected with T. annulata, five were infected with T. orientalis, and 14 had mixed infections. This is the first report of T. orientalis from Haryana, India. Representative sequences of T. annulata (ON248941) and T. orientalis (ON248942) were submitted in GenBank. The standardized multiplex PCR assay used in this study was specific, sensitive, for the screening of field samples.

Theileria infection in bullfighting cattle in Thailand

Background and Aim

An apicomplexan protozoan parasite, namely, Theileria, primarily causes theileriosis in cattle worldwide. The virulence of the disease has been neglected because of it's low pathogenicity. However, the disease can have a substantial effect, depending on the virulence of the species, low host immunity, and coinfection. In Thailand, the molecular detection of Theileria infection in bullfighting cattle and its hematological alterations have not been reported. Thus, this study aimed to identify Theileria species in bullfighting cattle in Thailand.

Materials and Methods

Blood samples were collected from bullfighting cattle presented at the Prince of Songkla University Animal Hospital and were determined on the basis of hematological evaluation and DNA extraction. Molecular detection using the 18s rRNA and merozoite surface antigen genes was conducted for Theileria spp. and Theileria orientalis, respectively. In addition, bidirectional sequencing of the positive samples was performed. Hematological alterations between Theileria infected and uninfected groups were statistically evaluated.

Results

The levels of Theileria spp. and T. orientalis infection in bullfighting cattle were 44.62% (58/130) and 41.54% (54/130), respectively. Theileria orientalis, Theileria sinensis, and Theileria spp. infections were identified in bullfighting cattle samples. Hematological evaluation indicated that the red blood cell (RBC) level was significantly lower in Theileria-infected cattle.

Conclusion

This study was the first to use molecular techniques in the identification of Theileria infection in bullfighting cattle in Thailand, with nearly one-half of the study population infected. Theileria infection in bullfighting cattle altered the RBC level, resulting in anemia. Therefore, tick control measures should be promoted.