Molecular detection and genetic diversity of Leucocytozoon sabrazesi in chickens in Thailand

Abstract

Leucocytozoon sabrazesi is the intracellular protozoa of leucocytozoonosis, which is transmitted by the insect vectors and affects chickens in most subtropical and tropical regions of the globe, except South America, and causing enormous economic losses due to decreasing meat yield and egg production. In this study, L. sabrazesi gametocytes have been observed in the blood smears, and molecular methods have been used to analyse the occurrence and genetic diversity of L. sabrazesi in blood samples from 313 chickens raised in northern, western and southern parts of Thailand. The nested polymerase chain reaction (nested PCR) assay based on the cytb gene revealed that 80.51% (252/313) chickens were positive of L. sabrazesi. The phylogenetic analysis indicated that L. sabrazesi cytb gene is conserved in Thailand, showed 2 clades and 2 subclades with similarity ranged from 89.5 to 100%. The diversity analysis showed 13 and 18 haplotypes of the sequences from Thailand and from other countries, respectively. The entropy analyses of nucleic acid sequences showed 26 high entropy peaks with values ranging from 0.24493 to 1.21056, while those of amino acid sequences exhibited 5 high entropy peaks with values ranging from 0.39267 to 0.97012. The results; therefore, indicate a high molecular occurrence of L. sabrazesi in chicken blood samples with the associated factors that is statistically significant (p < 0.05). Hence, our results could be used to improve the immunodiagnostic methods and to find appropriate preventive control strategies or vaccination programs against leucocytozoonosis in order to mitigate or eliminate the harmful impact of this infection on chicken industry.

Molecular Identification of Host Blood Meals and Detection of Blood Parasites in Culicoides Latreille (Diptera: Ceratopogonidae) Collected from Phatthalung Province, Southern Thailand

“…Haemosporidian infections in domestic hens and wild birds have been expanding in Thailand [ 39 , 40 , 41 , 42 ]. In the study by Pramual et al, [ 21 ] it was demonstrated that C. mahasarakhamense , C. guttifer , and C. huffi were infected with Leucocytozoon and two of P .…”

Insights into the Biology of Leucocytozoon Species (Haemosporida, Leucocytozoidae): Why Is There Slow Research Progress on Agents of Leucocytozoonosis?

“…The slow progress in understanding the biology of leucocytozoids is unfortunate. Species of Leucocytozoon , the agents of avian leucocytozoonosis, are not only cosmopolitan, but, contrary to haemoproteids (Haemoproteidae) and malaria parasites (Plasmodiidae), they are actively transmitted in countries with not only warm climates [ 3 , 4 , 5 , 10 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ], but cold climates [ 7 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ] and high mountains [ 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ]. In other words, birds are under the threat of leucocytozoonosis nearly globally.…”

Molecular genetic diversity and bioinformatic analysis of Leucocytozoon sabrazesi based on the mitochondrial genes cytb, coxI and coxIII and co-infection of Plasmodium spp.

“…There have been studies of genetic diversity of Leucocytozoon sp. based on the mitochondrial gene sequences in several countries, and almost all of these studies focused on the cytb gene [ 8 , 18 , 29 , 44 ]. However, there has been no information available regarding the genetic diversity and phylogeny of L. sabrazesi mitochondrial genes in Thailand until now.…”