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Amaç: Bu çalışma, Niğde yöresi evcil ve yabani güvercinlerinde kan protozoonlarının prevalansının saptanması amacı ile yapılmıştır. Yöntemler: Çalışma materyalini Niğde yöresinde 105’i evcil (55 dişi, 50 erkek) ve 111’i yabani (53 dişi, 58 erkek) olmak üzere toplam 216 güvercin oluşturmuştur. Bu güvercinlerin kanat altı venasından (vena cutanea ulnaris) kan alınarak her güvercin için kan frotileri hazırlanmış ve mikroskopta kan protozoonları yönünden incelenmiştir. Bulgular: Muayenesi yapılan 216 güvercinin 107’si (%49,54) Haemoproteus columbae ile enfekte bulunmuştur. Mikroskobik incelemelerde, 105 evcil güvercinin 9’unda (%8,57) ve 111 yabani güvercinin 98’inde (%88,29) H. columbae saptanmıştır. Haemoproteus columbae enfeksiyonunun pozitifliği, istatistiksel olarak evcil ve yabani güvercinler arasında önemli bulunmuştur (p<0,01). Haemoproteus columbae ile enfekte 107 güvercinde ortalama parazitemi oranı %2,85 olarak tespit edilmiştir. Mikroskobik muayenesi yapılan kan frotilerinde Plasmodium, Leucocytozoon ve Trypanosoma türlerine rastlanmamıştır. Sonuç: Niğde yöresinde evcil ve yabani güvercinlerinde H. columbae varlığı ilk kez bu çalışma ile bildirilmiştir.

Host resistance against parasites depends on three aspects: the ability to prevent, control and clear infections. In vertebrates the immune system consists of innate and adaptive immunity. Innate immunity is particularly important for preventing infection and eradicating established infections at an early stage while adaptive immunity is slow, but powerful, and essential for controlling infection intensities and eventually clearing infections. Major Histocompatibility Complex (MHC) molecules are central in adaptive immunity, and studies on parasite resistance and MHC in wild animals have found effects on both infection intensity (parasite load) and infection status (infected or not). It seems MHC can affect both the ability to control infection intensities and the ability to clear infections. However, these two aspects have rarely been considered simultaneously, and their relative importance in natural populations is therefore unclear. Here we investigate if MHC class I genotype affects infection intensity and infection status with a frequent avian malaria infection Haemoproteus majoris in a natural population of blue tits Cyanistes caeruleus. We found a significant negative association between a single MHC allele and infection intensity but no association with infection status. Blue tits that carry a specific MHC allele seem able to suppress H. majoris infection intensity, while we have no evidence that this allele also has an effect on clearance of the H. majoris infection, a result that is in contrast with some previous studies of MHC and avian malaria. A likely explanation could be that the clearance rate of avian malaria parasites differs between avian malaria lineages and/or between avian hosts.

1. Understanding how parasites fill their ecological niches requires information on the processes involved in the colonization and exploitation of unique host species. Switching to hosts with atypical attributes may favour generalists broadening their niches or may promote specialization and parasite diversification as the consequence. 2. We analysed which blood parasites have successfully colonized hummingbirds, and how they have evolved to exploit such a unique habitat. We specifically asked (i) whether the assemblage of Haemoproteus parasites of hummingbirds is the result of single or multiple colonization events, (ii) to what extent these parasites are specialized in hummingbirds or shared with other birds and (iii) how hummingbirds contribute to sustain the populations of these parasites, in terms of both prevalence and infection intensity. 3. We sampled 169 hummingbirds of 19 species along an elevation gradient in Southern Ecuador to analyse the host specificity, diversity and infection intensity of Haemoproteus by molecular and microscopy techniques. In addition, 736 birds of 112 species were analysed to explore whether hummingbird parasites are shared with other birds. 4. Hummingbirds hosted a phylogenetically diverse assemblage of generalist Haemoproteus lineages shared with other host orders. Among these parasites, Haemoproteus witti stood out as the most generalized. Interestingly, we found that infection intensities of this parasite were extremely low in passerines (with no detectable gametocytes), but very high in hummingbirds, with many gametocytes seen. Moreover, infection intensities of H. witti were positively correlated with the prevalence across host species. 5. Our results show that hummingbirds have been colonized by generalist Haemoproteus lineages on multiple occasions. However, one of these generalist parasites (H. witti) seems to be highly dependent on hummingbirds, which arise as the most relevant reservoirs in terms of both prevalence and gametocytaemia. From this perspective, this generalist parasite may be viewed as a hummingbird specialist. This challenges the current paradigm of how to measure host specialization in these parasites, which has important implications to understand disease ecology.

Haemosporidians are a diverse group of vector-borne parasitic protozoa that includes the agents of human malaria; however, most of the described species are found in birds and reptiles. Although our understanding of these parasites’ diversity has expanded by analyses of their mitochondrial genes, there is limited information on these genes’ evolutionary rates. Here, 114 mitochondrial genomes (mtDNA) were studied from species belonging to four genera: Leucocytozoon, Haemoproteus, Hepatocystis, and Plasmodium. Contrary to previous assertions, the mtDNA is phylogenetically informative. The inferred phylogeny showed that, like the genus Plasmodium, the Leucocytozoon and Haemoproteus genera are not monophyletic groups. Although sensitive to the assumptions of the molecular dating method used, the estimated times indicate that the diversification of the avian haemosporidian subgenera/genera took place after the Cretaceous–Paleogene boundary following the radiation of modern birds. Furthermore, parasite clade differences in mtDNA substitution rates and strength of negative selection were detected. These differences may affect the biological interpretation of mtDNA gene lineages used as a proxy to species in ecological and parasitological investigations. Given that the mitochondria are critically important in the parasite life cycle stages that take place in the vector and that the transmission of parasites belonging to particular clades has been linked to specific insect families/subfamilies, this study suggests that differences in vectors have affected the mode of evolution of haemosporidian mtDNA genes. The observed patterns also suggest that the radiation of haemosporidian parasites may be the result of community-level evolutionary processes between their vertebrate and invertebrate hosts.

Haemosporidian parasites are prevalent worldwide and can cause economic losses in poultry production. These parasites are arousing interest in Thailand and are found in many avian species. There is insufficient information on the genetic diversity of these alveolates from the largest families - Plasmodidae, Haemoprotidae and Leucocytozoidae - specifically parasitising ducks, turkeys, and geese. Blood samples from 116 backyard poultry (60 ducks, 36 turkeys and 20 geese) in northeastern Thailand were investigated for spp., spp. and spp. infections using microscopic examination and molecular approaches. A total of 37/116 birds (31.9%) had confirmed infections. The prevalence was 69.4% (25/36) in turkeys, 18.3% (11/60) in ducks, and 5.0% (1/20) in geese. Of these 37 positives, 86.5% were sp., 10.8% were and 2.7% were . Sequence analysis based on the cytochrome gene identified seven lineages, of which two were new lineages in backyard poultry. This is the first report on the prevalence of haemosporidian parasites in backyard poultry in northeastern Thailand. The results provide important data for better understanding the molecular epidemiology of haemosporidian parasites infection in poultry in this region, which will be helpful in controlling these blood parasites.

Immunological capability shows a sexual dimorphism in diverse animal species. Females are generally more immunocompetent than males, leading to the higher susceptibility of males to infection compared to females and thus greater infection-related pathology in males. These sex-differences in immunity remain understudied in birds. Here, we compared the percentage of parasitemia of three different parasite lineages belonging to the morphological species Haemoproteus majoris (namely, PARUS1, PHSIB1 and WW2) in terms of the sex of birds living in a natural community. We found that parasitemia (percentage of erythrocytes infected with parasites) of WW2 lineage, but not of the other two lineages of H. majoris, is higher in male birds compared to female birds. Similarly, we showed that the total parasitemia of these three H. majoris lineages is higher in male birds compared to female birds. Our study points out that male birds at the community level may be more susceptible to infection by certain parasites than female birds. We propose that sexual dimorphism in parasitemia of certain parasites in host birds might be more common than previously thought, similar to what is observed in other species, influencing host population dynamics in a sex-specific manner. Therefore, it can be speculated that infection by certain parasites might differentially affect male and female birds, possibly resulting in a bias in survival rates between sexes due to infections, in certain contexts.

Background Haemoproteus is a sister genus to malaria parasites ( Plasmodium ), which both belong to the order Haemosporida (Apicomplexa). Parasites of both genera are flourishing in birds, however, Haemoproteus species are noticeably less investigated. This is unfortunate because knowledge about close relatives of malaria pathogens is important for better understanding the evolutionary origin and basic biological features of the entire group of haemosporidian infections. Moreover, recent findings show that Haemoproteu s species can cause severe damage of various bird organs due to megalomeronts and other exo-erythrocytic stages. These haemosporidians are remarkably diverse, but remain neglected partly due to difficulties in species identification. Hundreds of Haemoproteus genetic lineages have been reported in birds, and numerous new lineages are found each year, but most remain unidentified to the species level. Numerous new Haemoproteus pathogens were described during the past 20 years. However, keys for their identification are absent. Identification of Haemoproteus species remains a difficult task and is an obstacle for better understanding of the distribution and epidemiology of these parasites. This study aimed to develop comprehensive keys for the identification of described avian Haemoproteus species using morphological features of their blood stages (gametocytes). Methods Type and voucher preparations of avian Haemoproteus species were accessed in museums in Europe, Australia and the USA. Gametocytes of most described species were examined, and these data formed a background for this study. The data also were considered from published articles containing parasite species descriptions. The method of dichotomous keys was applied. The most difficult steps in the keys were accompanied with references to the corresponding parasite pictures. Results In all, 201 published articles were included in this review. Morphological diagnostic features of gametocytes of all described Haemoproteus species were analysed and compared. Illustrated keys for identification of these parasite species were developed. Available information about the molecular characterization of Haemoproteus parasites was provided. Conclusion This review shows that 177 described species of avian Haemoproteus can be distinguished and identified in blood films using morphological characters of their gametocytes and host cells. These species were incorporated in the keys. Information about possible morphologically cryptic parasites was provided. Molecular markers are available for only 42% of the described Haemoproteus parasites, calling for researchers to fill this gap.

Avian blood parasites have been intensively studied using morphological methods with limited information on their host specificity and species taxonomic status. Now the analysis of gene sequences, especially the mitochondrial cytochrome b gene of the avian haemosporidian species of Haemoproteus, Plasmodium, and Leucocytozoon, offers a new tool to review the parasite specificity and status. By comparing morphological and genetic techniques, we observed nearly the same overall prevalence of haemosporidian parasites by microscopy (19.8%) and polymerase chain reaction (PCR) (21.8%) analyses. However, in contrast to the single valid Leucocytozoon species (L. toddi) in the Falconiformes we detected 4 clearly distinctive strains by PCR screening. In the Strigiformes, where the only valid Leucocytozoon species is L. danilewskyi, we detected 3 genetically different strains of Leucocytozoon spp. Two strains of Haemoproteus spp. were detected in the birds of prey and owls examined, whereas the strain found in the tawny owl belonged to the morphospecies Haemoproteus noctuae. Three Plasmodium spp. strains that had already been found in Passeriformes were also detected in the birds of prey and owls examined here, supporting previous findings indicating a broad and nonspecific host spectrum bridging different bird orders.

Understanding why some parasites emerge in novel host communities while others do not has broad implications for human and wildlife health. In the case of haemosporidian blood parasites, epidemic wild bird mortalities on oceanic islands have been linked to Plasmodium spp., but not genera like Haemoproteus . Indeed, Haemoproteus is absent from many oceanic islands. By contrast, birds on continental islands share long coevolutionary histories with both Plasmodium and Haemoproteus , and are thus ideal model systems to elucidate eco-evolutionary endpoints associated with these parasites in oceanic islands. Here, we examine eco-evolutionary dynamics of avian haemosporidian in the Shola sky-island archipelago of the Western Ghats, India. Our analyses reveal that compared to Plasmodium , Haemoproteus lineages were highly host-specific and diversified via co-speciation with their hosts. We show that community structure of host-generalist Plasmodium was primarily driven by geographical factors (e.g. biogeographic barriers), while that of host-specialist Haemoproteus was driven by host species barriers (e.g. phylogenetic distance). Consequently, a few host species can harbour a high diversity of Plasmodium lineages which, in turn, are capable of infecting multiple host species. These two mechanisms can act in concert to increase the risk of introduction, establishment, and emergence of novel Plasmodium lineages in island systems.

Species of Haemoproteus (Haemoproteidae, Haemosporida) are common bird pathogens. Recent molecular studies combined with histopathology research have reported development of megalomeronts of these parasites in various organs, sometimes resulting in the death of the avian host. Five Common starlings (Sturnus vulgaris) were found naturally infected with Haemoproteus pastoris lineage hLAMPUR01. The parasite was identified using microscopic examination of blood films and DNA sequences. Infected bird organs were investigated histologically for (i) the presence of exo-erythrocytic stages and (ii) the patterns of development (morphology and localization) in different host individuals. For the first time, megalomeronts of Haemoproteus parasites were seen developing in the brain, while numerous others at different stages of maturation were found in the intestine, pancreas, kidneys, lungs, esophagus, spleen, gizzard, and trachea. Megalomeronts were predominantly roundish or oval, up to 800 μm, they were surrounded by a capsular-like wall and developed asynchronously in the same bird individual. After megalomeront maturation and rupture, a massive infiltration of blood cells occurred, indicating the hemorrhagic processes. Review of available data showed that different Haemoproteus species produce markedly different megalomeronts, morphology of which can probably be predicted using phylogenetic analysis based on partial sequences of cytochrome b gene.