BACKGROUND: The protozoan Haemoproteus belongs to the Phylum Apicomplexa, Class Sporozoa, and Order Haemosporina. Avian haemosporidian are protozoan parasites that use birds as hosts around the world. Many species of wild and domestic doves are natural hosts of different species of Haemoproteus. Blood-sucking arthropods are the main vectors of these blood parasites.OBJECTIVES: The aim of this study was the microscopic and molecular investigation of the protozoan Haemoproteus columbae in the blood of infected pigeons in Torkaman County, Iran.METHODS: Blood samples and tubes containing ethylenediaminetetraacetic acid (EDTA) anticoagulant were collected from 96 domestic pigeons randomly from 14 pigeon lofts and different parts of Torkaman County.Pigeons were also inspected for infection with the host-vector Pseudolynchia canariensis. In the next step, blood smears were stained with Giemsa and examined microscopically. Also, blood tubes containing EDTA were tested by PCR method on the cytochrome b gene.RESULTS: Microscopic and molecular examination of peripheral blood showed that 62 (64.58 %) and 73 (76.04 %) of the investigated pigeons were contaminated, respectively. Of the 62 infected pigeons infected with the Haemoproteus, 28 pigeons (66.66 %) were male, and 34 (62.96 %) were female. Also, the infestation with Pseudolynchia canariensis was observed in 4 (28.57 %) pigeon lofts.CONCLUSIONS: The preliminary investigation shows the high rate of Haemoproteus infection in pigeons in Torkaman County. Further studies to determine the prevalence and accurate identification of the species infecting pigeons in this region require PCR testing and sequencing of infected blood samples.

BACKGROUND: Salmonellosis is a dangerous disease that can threaten the health of humans and animals. This disease can lead to economic losses annually; therefore, many studies have been conducted to prevent this disease.OBJECTIVES: The current study aims to design a recombinant chimera protein HBHA-Omp28 as a vaccine against Salmonella typhimurium.METHODS: The nucleotide and amino acid sequences of Omp28 and HBHA proteins were first extracted from the NCBI database. Then, the recombinant chimera of HBHA-Omp28 was bioinformatically assembled using a rigid linker. Epitope prediction of T and B cells, antigenicity, allergenicity, and physicochemical features assessments of HBHA-Omp28 were done using Immune Epitope Database (IEDB), ABCpred, VaxiJen, AllerTOP and ProtParam online servers, respectively. To assess the secondary and tertiary structures, the Self-Optimized Prediction Method with Alignment (SOPMA) and the Iterative Threading ASSEmbly Refinement (I-TASSER) server were used, respectively. Molecular docking between recombinant chimera and TLR4/MD2 receptor was assessed by ClusPro server. Finally, after codon optimization of nucleotide sequence of recombinant chimera to express in Escherichia Coli k-12 strain, the cloning of recombinant chimera in pET21-a (+) vector was examined.RESULTS: The designed recombinant chimera was classified as an antigenic and non-allergenic protein with molecular weight of 34.19 kDa. According to the results of molecular docking study, the HBHA-Omp28 protein was able to bind to TLR4/MD2 receptor using 9 hydrogen bonds. The results of cloning study demonstrated that HBHA-Omp28 successfully cloned into pET21-a (+).CONCLUSIONS: The designed recombinant chimera can be an appropriate vaccine against salmonella bacteria.