Development and comparative evaluation of droplet digital PCR and quantitative PCR for the detection and quantification of Chlamydia psittaci.

Chlamydia psittaci is a zoonotic pathogen mainly transmitted by psittacine birds and poultry. The low shedding rate of the pathogen in the apparently healthy birds and human clinical cases may result in false-negative results. In the present study, a droplet digital PCR (ddPCR) assay was developed and compared with optimized quantitative PCR (qPCR) for the detection of C. psittaci from the clinical samples. The ddPCR assay was found to be comparatively more sensitive than the qPCR, wherein the limit of detection (LOD) of ddPCR was upto 2.4 copies of the DNA template, whereas, the qPCR could detect upto 38 copies of the DNA template in the reaction mixture. Overall, the developed ddPCR assay was found to be robust, specific, and could reliably quantify up to 17.8 copies of the DNA template. Finally, the applicability of the developed ddPCR assay was tested by screening the field samples (n = 124), comprising lung tissues from dead poultry and feral birds; pooled faecal samples from the free-living birds, commercial and backyard poultry farms; pharyngeal and cloacal swabs collected from the duck farms. Of these, a total of seven samples were found to be positive by the ddPCR, whereas, three samples could be detected as positive using the qPCR. The developed ddPCR could serve as a reliable screening tool, particularly in those clinical samples wherein the shedding of C. psittaci is substantially very low.

Effect of oxfendazole to control Taenia solium cysticercosis in pigs in Punjab state of India.

Taenia solium cysticercosis is a neglected zoonosis prevalent in developing countries including India. The disease has a substantial health impact in India. The control of this disease in pigs would benefit both veterinary and public health. In view of this, the current study was designed to know the effectiveness of oxfendazole against T. solium in pigs reared in Punjab, India. A randomized controlled trail was designed with two groups of treatment (T1 and T2) and a control group. Pigs from ten different litters were selected. Pigs (4 months of age) from the same litter were randomly assigned into these three groups. Treatment 1 (T1) group pigs received oxfendazole@30 mg/kg body weight at 4 months of age, treatment 2 (T2) received oxfendazole@30 mg/kg body weight treatment at 9 months of age and the control group (C) received placebo at 4 months of age. Blood samples were collected at three intervals at the age of 4, 9 and 12 months. Sandwich antigenic ELISA was performed to determine the serological status of disease in pigs. Three piglets in treatment 1 were found positive at 4 months but were recorded seronegative in subsequent samplings. One pig in the control group was positive at 9 and 12 months of age. Results showed promising effects of oxfendazole for the control of T. solium cysticercosis in pigs of Punjab, India.