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Gametocytes of Leucocytozoon mathisi (1-8) and Leucocytozoon buteonis (9-16) in fusiform host cells from the blood of Accipiter cooperii (1-4), Accipiter nisus (5-8), Buteo jamaicensis (9-12), and Buteo regalis (13-16). Macrogametocytes (1, 2, 5, 6, 9, 10, 13, 14). Microgametocytes (3, 4, 7, 8, 11, 12, 15, 16). Arrows: fusiform cytoplasmic processes of host cells. Giemsa-stained thin blood films. Bar 5 10 mm.
Source publication
The current taxonomy of leucocytozoids (Haemosporida, Leucocytozoidae) is based on the morphology of blood stages of the parasites and on limited information about their specificity. Recent molecular studies have revealed a remarkable genetic diversity of leucocytozoids, indicating that their taxonomic diversity may be greater than in the current c...
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Haemoproteus (Haemoproteus) jenniae n. sp. (Haemosporida: Haemoproteidae) is described from a Galapagos bird, the swallow-tailed gull Creagrus furcatus (Charadriiformes, Laridae), based on the morphology of its blood stages and segments of the mitochondrial cytochrome b (cyt b) gene. The most distinctive features of H. jenniae development are the c...
Citations
... Plasmodium, Haemoproteus and Leucocytozoon well known as avian haematozoan infections of domestic and wild birds that can be decreased their productivity with high mortality and maybe affects their population's dynamics (Mirzaei et al., 2020). Avian blood parasites that called leucocytozoids are infect a wide variety of avian hosts (Valkiünas et al., 2010;Zhao et al., 2014). All Leucocytozoids have a hostspecific pathogenicity in the levels of the order, family and occasionally species (Forrester and Greiner, 2009). ...
... Avian haemosporidian (Apicomplexa: Haemosporida) includes the genera Haemoproteus, Plasmodium, Fallisia and Leucocytozoon, and these are vector-borne parasites distributed worldwide, except Antarctica [1][2][3]. There are about 277 described species among 23 host orders [4][5][6][7]. ...
Avian malaria and leucocytozoonosis can cause fatal diseases, whereas avian trypanosomiasis is reported to be harmless in chickens. Backyard chickens can be infected by several pathogens, including blood parasites, that may shed to industrial poultry production, with a consequently higher economic impact. This study aimed to investigate the presence of several blood parasites (Plasmodium, Leucocytozoon and Trypanosoma) in backyard chickens raised in Southern Thailand, using PCR-based detection and microscopic methods. From June 2021 to June 2022, 57 backyard chickens were sampled. Fresh thin blood smears were prepared from 11 individuals, and buffy coat smears were prepared from 55 of them. Both thin blood smears and buffy coat smears were used for microscopic analysis. Two nested PCR protocols that amplify a fragment of cytochrome b (cytb) and small subunit rRNA (SSU rRNA) genes were used to identify Haemosporida and Trypanosoma parasites, respectively. The number of positive samples was higher with the application of nested PCR than when buffy coat smears were used. Three new Plasmodium lineages (GALLUS47-49) and thirteen Leucocytozoon lineages (GALLUS50-62) were found. Trophozoites, meronts and gametocytes of Plasmodium gallinaceum (GALLUS01) were present in one thin blood smear. All thin blood smears revealed Leucocytozoon infections, but only three samples were a single infection. These three samples revealed the presence of fusiform host cell–parasite complexes, of which the morphological features resembled those of Leucocytozoon macleani (possible synonym is Leucocytozoon sabrazesi), while the cytb showed that this parasite is closely related to the lineage GALLUS06-07, described as Leucocytozoon schouteni. The Trypanosoma prevalence was 33.33%; it was present in only one of the thin blood smears, and it resembles Trypanosoma calmettei. This study showed the prevalence of a high diversity of Plasmodium (64.91%) and Leucocytozoon (89.47%) in Thai chickens. Both nested-PCR and buffy coat smear can be used as the diagnostic tool for the testing of Plasmodium, Leucocytozoon and Trypanosoma for parasitic control in backyard chickens and poultry farms. The information on the parasite species that can be found in chickens raised in Southern Thailand was also considered as the baseline information for further study.
... Blood host cells inhabited by Leucocytozoon parasites were identified only for a few parasite species, with most studies not reporting this information in the parasite description or the host cell is just mentioned and images are not provided [5,[28][29][30][31][32][33][34][35][36]. This is not surprising, since the merozoites and young gametocytes of Leucocytozoon are not commonly observed in blood films of naturally infected wild birds. ...
... As a result, the description of new Leucocytozoon species is based on the morphological features of mature gametocytes [4,5], not considering the host cell infected by the parasite. Most described Leucocytozoon species seem to inhabit erythrocytes [5,16,35,37], fewer inhabit mononuclear leukocytes [5,16,28,28,34], and only two have been confirmed to inhabit thrombocytes [2,15]. The present study adds three lineages to the list of Leucocytozoon parasites that can develop in erythrocytes (STUR1, TURMER15, NEVE01), one lineage that can develop in lymphocytes (PARUS4), and two lineages that can develop in thrombocytes (WW6 and AFR205). ...
Leucocytozoon parasites remain poorly investigated in comparison to other haemosporidians. The host cell inhabited by their blood stages (gametocytes) remains insufficiently known. This study aimed to determine the blood cells inhabited by Leucocytozoon gametocytes in different species of Passeriformes and to test if this feature has a phylogenetic importance. We microscopically analyzed blood films stained with Giemsa from six different bird species and individuals and used PCR-based methods for parasite lineage identification. The DNA sequences obtained were applied for phylogenetic analysis. Leucocytozoon parasite from the song thrush Turdus philomelos (cytochrome b lineage STUR1), the blackbird Turdus merula (undetermined lineage), the garden warbler Sylvia borin (unknown lineage) inhabited erythrocytes, a parasite from the blue tit Cyanistes caeruleus (PARUS4) infects lymphocytes, while in the wood warbler Phylloscopus sibilatrix (WW6) and the common chiffchaff Phylloscopus collybita (AFR205) they were found inhabiting thrombocytes. Parasites infecting thrombocytes were closely related, while the parasites infecting erythrocytes were placed in three different clades, and the one found in lymphocytes was placed in a separate clade. This shows that the determination of host cells inhabited by Leucocytozoon parasites can be phylogenetically important and should be considered in future species descriptions. Noteworthy, phylogenetic analysis might be used for the prediction of which host cells parasite lineages might inhabit.
... 4 Both L. buteonis and L. mathisi belong to the L. toddi group [93]. The first two species are readily distinguishable from each other due to the different length and form of the host cell cytoplasmic processors, which are significantly shorter in L. mathisi (compare Figure 3c-f with Figure 3g-l) [125]. 5 Numerous Leucocytozoon lineages were found in owls (Strigiformes) worldwide [19], however, the molecular characterization of L. danilewskyi (synonym is L. ziemanni, see [168]) from its type vertebrate host Athene noctuae is absent. ...
... Examples are the parasite of ducks and geese, L. simondi (synonyms are L. anatis and L. anseris); the parasite of passerines, L. fringillinarum (synonyms are L. brimonti, L. bouffardi, L. cambournaci, L. chloropsidis, L. deswardti, L. dutoiti, L. enriquesi, L. gentili, L. icteris, L. molpastis, L. monardi, L. muscicapa, L. parulis, L. prionopis, L. pittae, L. roubaudi, L. thraupis, L. sturni, L. timallae, L. whitworthi), and others [4]. It is important to note that recent molecular studies suggest that some of these morphotypes might be groups of cryptic species, sometimes not even closely related to each other [125,171,174,228]. In other words, the interim grouping of morphotypes by parasite species with nomenclatural priority within a bird order helps to clearly define potentially synonymous parasite descriptions. ...
... For example, the parasites of diurnal raptors, Leucocytozoon mathisi and L. buteonis, belong to the L. toddi group and produce fusiform processes (Figure 3c-l). These species can be distinguished by the lengths and form of the processes [125], which are significantly shorter in L. mathisi (compare Figure 3c-f with Figure 3g-l). Different forms of fusiform processes in Leucocytozoon parasites are shown in Figure 3. ...
Blood parasites of the genus Leucocytozoon (Leucocytozoidae) only inhabit birds and represent a readily distinct evolutionary branch of the haemosporidians (Haemosporida, Apicomplexa). Some species cause pathology and even severe leucocytozoonosis in avian hosts, including poultry. The diversity of Leucocytozoon pathogens is remarkable, with over 1400 genetic lineages detected, most of which, however, have not been identified to the species level. At most, approximately 45 morphologically distinct species of Leucocytozoon have been described, but only a few have associated molecular data. This is unfortunate because basic information about named and morphologically recognized Leucocytozoon species is essential for a better understanding of phylogenetically closely related leucocytozoids that are known only by DNA sequence. Despite much research on haemosporidian parasites during the past 30 years, there has not been much progress in taxonomy, vectors, patterns of transmission, pathogenicity, and other aspects of the biology of these cosmopolitan bird pathogens. This study reviewed the available basic information on avian Leucocytozoon species, with particular attention to some obstacles that prevent progress to better understanding the biology of leucocytozoids. Major gaps in current Leucocytozoon species research are discussed, and possible approaches are suggested to resolve some issues that have limited practical parasitological studies of these pathogens.
... Currently, molecular tools have provided valuable information for species delimitation, leading to species differentiation with slightly different morphologies (Mantilla et al., 2016;Sehgal et al., 2006;Valkiūnas et al., 2010). Still, it is noteworthy that only 20% of the cyt b sequences of Haemoproteus deposited in Genbank are identified at the species level, only having one lineage identified to species level infecting Anseriformes: H. macrovacuolatus. ...
Currently, there are three recognized species of haemoproteids infecting Anseriformes: Haemoproteus nettionis, H. macrovacuolatus, and H. greineri. Unfortunately, genetic information associated with a morphotype is available only for H. macrovacuolatus. We recently found a parasite morphologically compatible with Haemoproteus gabaldoni, a species Bennet (1993) described in a Cairina moschata (Muscovy duck) from Venezuela. This species was synonymized to H. nettionis by Valkiunas (2005), arguing not enough morphological differentiation between them; it was even said that H. greineri could be as well a synonym of H. nettionis. In this study, we aimed to provide evidence to determine if Haemoproteus gabaldoni is a different species of H. nettionis and help to clarify other species status. We first performed morphological and morphometrical analyses and compared this information against the parahapantotypes of H. greineri, H. gabaldoni and material diagnosed as H. nettionis provided by the International Reference Centre for Avian Haematozoa (IRCAH), and H. macrovacuolatus from the Host-Parasite Relationship Study Group (GERPH, in Spanish Grupo de Estudio Relación Parásito Hospedero) biological collection. We used Principal Component Analysis (PCA) of dimensionless standard morphometrical variables from gametocytes. Furthermore, we amplified a small fragment of cytochrome b (cyt b) to compare the sequence with information in GenBank and Malavi through phylogenetic analyses and haplotype networks. PCA. analyses revealed the presence of three distinct groups in the samples studied, supported in the morphological traits of each parasite species analyzed; phylogenetic analyses grouped parasite lineages separately according to the host and continent of provenance. Such results indicate that, H. gabaldoni, is a different species from H. nettionis. One more time, it is demonstrated the importance of linking barcode surveys to morphological studies. Finally, it is highlighted the importance of biological collections as repositories of worldwide biodiversity.
... Clade L201 contains five sub-clades featuring similar lineages (L201a to L201f ). Sub-clade L201a contains lBUBT2 (29), lBUTBUT07 (6), lBUTBUT08 (2), lBUT-BUT09 (1), lBUTBUT10 (1), and lBUTJAM15 (1). Lineage lBUTJAM15 was found in Buteo jamaicensis (1) in the USA [10], the others mostly in Buteo buteo in Western Europe. ...
... Last, sub-clade L201f contains lCLAPOM02 and lCLAPOM03, which were detected in one specimen of the lesser spotted eagle Clanga pomarina in Austria. Based on a combined analysis of morphological and CytB sequence data, [29] linked lBUBT2 (L201a), lBUT-JAM10 (L201e), and lBUTREG01 (L201b) to Leucocytozoon buteonis. The latter three lineages belong to distinct sub-clades (L201, Fig. 4) and differ by 1.5 to 3.4% from each other in the CytB. ...
... Scale bars = 50 µm; insert scale bars = 20 µm in Circus aeruginosus (1) from Austria. Valkiūnas et al. [29] linked lACCOP01 and lACNI04 to Leucocytozoon mathisi based on the morphological similarity of their gametocytes and host cells. The two latter lineages fall into sub-clades L201a and L201b and differ by 4.6% in the CytB. ...
Background
The order Accipitriformes comprises the largest group of birds of prey with 260 species in four families. So far, 21 haemosporidian parasite species have been described from or reported to occur in accipitriform birds. Only five of these parasite species have been characterized molecular genetically. The first part of this study involved molecular genetic screening of accipitriform raptors from Austria and Bosnia-Herzegovina and the first chromogenic in situ hybridization approach targeting parasites in this host group. The aim of the second part of this study was to summarize the CytB sequence data of haemosporidian parasites from accipitriform raptors and to visualize the geographic and host distribution of the lineages.
Methods
Blood and tissue samples of 183 accipitriform raptors from Austria and Bosnia-Herzegovina were screened for Plasmodium , Haemoproteus and Leucocytozoon parasites by nested PCR, and tissue samples of 23 PCR-positive birds were subjected to chromogenic in situ hybridization using genus-specific probes targeting the parasites’ 18S rRNAs. All published CytB sequence data from accipitriform raptors were analysed, phylogenetic trees were calculated, and DNA haplotype network analyses were performed with sequences from clades featuring multiple lineages detected in this host group.
Results
Of the 183 raptors from Austria and Bosnia-Herzegovina screened by PCR and sequencing, 80 individuals (44%) were infected with haemosporidian parasites. Among the 39 CytB lineages detected, 18 were found for the first time in the present study. The chromogenic in situ hybridization revealed exo-erythrocytic tissue stages of Leucocytozoon parasites belonging to the Leucocytozoon toddi species group in the kidneys of 14 infected birds. The total number of CytB lineages recorded in accipitriform birds worldwide was 57 for Leucocytozoon , 25 for Plasmodium , and 21 for Haemoproteus .
Conclusion
The analysis of the DNA haplotype networks allowed identifying numerous distinct groups of lineages, which have not yet been linked to morphospecies, and many of them likely belong to yet undescribed parasite species. Tissue stages of Leucocytozoon parasites developing in accipitriform raptors were discovered and described. The majority of Leucocytozoon and Haemoproteus lineages are specific to this host group, but most Plasmodium lineages were found in birds of other orders. This might indicate local transmission from birds kept at the same facilities (raptor rescue centres and zoos), likely resulting in abortive infections. To clarify the taxonomic and systematic problems, combined morphological and molecular genetic analyses on a wider range of accipitriform host species are needed.
... Regarding the examined blood smears, oval or rounded gametocytes of L. caulleryi were found in the erythrocytes and leukocytes as previously reported by Valkiūnas (11), Taylor et al. (32), and Win et al. (33). Gametocytes can be differentiated according to the size and the usual haemosporidian sexual dimorphic characters (13,34,35). It was noticed that L. caulleryi gamonts induced a characteristic disappearance of the cell nucleus and resulted in structural dramatic structural changes in RBCs, including enlarged and elongated fusiform (formation of hornlike extensions tapering at both ends or spindle-shaped cells). ...
Despite the vast Egyptian poultry production, scanty information is available concerning the infection of haemprotozoan parasites as pathogens in commercial broilers. In the present study, we provided the first detection of leucocytozoonosis in five broiler chicken flocks in El-Beheira Egyptian governorate. Despite the low mortality rates in the affected flocks (0.3%-1% as a 5-day mortality), severe postmortem (hemorrhagic spots and scars) and histopathologic lesions appeared in different organs including skeletal muscles, liver, kidney, pancreas, abdominal cavity, and bursa of Fabricius. Evaluation of blood smears revealed gametocytes in erythrocytes and leukocytes. Conventional reverse transcriptase-PCR and partial sequence analysis of mitochondrial cytochrome oxidase b gene detected Leucocytozoon caulleryi. GenBank accession numbers of the five Egyptian L. caulleryi isolates were obtained. The five L. caulleryi were 99.9% identical to each other and 99.14% similar to the L. caulleryi mitochondrial DNA gene of Asian strains from India, Japan, Malaysia, South Korea, Taiwan, and Thailand.
... The intensity of infection was estimated as a percentage by counting the number of gametocyte host cells per 10,000 erythrocytes. The species of the genus Leucocytozoon was identified using the taxonomic keys following Valkiunas (2005) and Valkiunas et al. (2010). ...
... According to the morphological characteristics, the gametocytes could be considered as a species from the L. toddi group (Greiner and Kocan, 1977;Valkiunas, 2005). Based on pooled morphometric data, especially the length of the cytoplasmic processes and other features that depend on this character (Valkiunas et al., 2010), the species of Leucocytozoon was identified as L. buteonis. Morphometric data for macrogametocytes and host cells are given in Table 1. ...
Haemosporidian parasites are responsible for anemia, acute tissue degeneration, and depopulation in wild birds. This study aimed to investigate the prevalence of haemosporidians and also morphologic and molecular evaluation of tissue stages of Haemoproteus sp. in common buzzards (Buteo buteo). Eleven free-living common buzzards were referred to the Avian Clinic of Veterinary School of Lorestan University with lethargy, weight loss, and ataxia. Gametocytes of Leucocytozoon buteonis were found in blood smears of six (54.5 %) birds, while one had simultaneous infection with blood stages of Haemoproteus and Leucocytozoon. During histopathological examinations, exo-erythrocytic stages of the genus Haemoproteus were seen in the lung and kidney of a dead bird. This study is the first report of exo-erythrocytic infection of Haemoproteus in common buzzards. Molecular assays confirmed the infection of Haemoproteus sp. (lineage BUTBUT15) in tissue samples. Phylogenetic analysis using cytochrome b gene suggested that BUTBUT15 was more closely related to the lineages isolated from the family Falconidae in contrast to the Accipitridae.
... Leucocytozoon spp. cause a vector-borne disease carried by Simuliidae black flies, and also by biting midges [2,3]. Almost all species of these parasites are nonpathogenic in domestic and wild birds, but some species cause severe pathology, such as L. caulleryi Mathis and Leger, 1909 in domestic chickens [2,4]. ...
... Each smear was examined for 10-15 min at low magnification (× 400). The number of parasites per 10,000 red blood cells was counted at high magnification (× 1000) to estimate the level of infection [3,13]. ...
... All extracted DNA was screened for blood parasites, including Haemoproteus spp., Plasmodium spp., Leucocytozoon spp. and Trypanosoma spp., using nested PCR as previously described [3,15]. Some of these samples were previously analyzed for Haemoproteus spp., Plasmodium spp. ...
Introduction:
Leucocytozoon spp. causes a vector-borne disease that is nonpathogenic in domestic and wild birds. To date, there was no report of leucocytozoonosis in raptors from Thailand.
Methods:
This study was carried out to perform morphological and molecular analyses of Leucocytozoon in 400 raptors at a rehabilitation center at Kasetsart University, Thailand during a 7-year period. The nested PCR was used to amplify the cytochrome b gene of Leucocytozoon with primers HaemNF1 and HaemNR3 as the primary reaction.
Results:
The light microscopic examination revealed Leucocytozoon gametocytes in five raptors; three diurnal raptors [two Crested Goshawks (CGs, Accipiter trivirgatus) and one Eastern Imperial Eagle (EIE, Aquila heliaca)], and two nocturnal raptors (one Oriental Scops-Owl (OSO, Otus sunia,) and one Short-eared Owl, Asio flammeus) and two species were identified: Leucocytozoon danilewskyi in both owl species and L. californicus in two CGs. The PCR method revealed more infection rate (2.0%, 8/400) than the light microscopic method including one Barred Eagle-Owl (BEO, Bubo sumatranus), one Brown Hawk Owl (BHO, Ninox scutulata) and one OSO. A phylogeny revealed that sequences from one SEO and one OSO were clustered with L. danilewskyi and the three Leucocytozoon sequences from diurnal raptors were clustered with L. californicus. The other three sequences from a BHO, a BEO and an OSO were ambiguous.
Conclusion:
This study combined morphological, morphometric and molecular phylogenetic analyses to identify L. danilewskyi in two species of owls, L. californicus in three diurnal raptors, and unknown species in three other owls, representing the first records of leucocytozoon infection in raptors from Thailand.
... Leucocytozoids (Apicomplexa, Haemosporida, Leucocytozoidae) are avian blood parasites which infect numerous species of avian hosts (Valkiünas, 2005;Forrester and Greiner, 2009;Valkiünas et al., 2010;Zhao et al., 2014). The pathogenicity of all leucocytozoids is host-specific at the avian level of order, family and in some cases at the species level (Forrester and Greiner, 2009). ...
... A cytochrome b gene (cyt b) (Hellgren et al., 2004;Bernotienè et al., 2016) was the most commonly used gene, because it provides a slower molecular clock for these parasites than for their host cells (Bensch et al., 2013). Therefore, numerous data regarding this gene have been stored in Genbank and MalAvi (Bensch et al., 2009;Valkiünas et al., 2010). Recent molecular work using the cyt b gene has shown Leucocytozoon parasites to be highly diverse (Sehgal et al., 2006a;Valkiünas et al., 2010). ...
... Therefore, numerous data regarding this gene have been stored in Genbank and MalAvi (Bensch et al., 2009;Valkiünas et al., 2010). Recent molecular work using the cyt b gene has shown Leucocytozoon parasites to be highly diverse (Sehgal et al., 2006a;Valkiünas et al., 2010). All molecular diagnostic and microscopic examinations have their differences as well as their advantages and disadvantages. ...
Leucocytozoon infections are found in birds and chicken in Southeast Asia including Thailand. Although chicken Leucocytozoon infections are common in Thailand, the associated hematological and molecular studies are scarce. Blood samples were collected from 52 backyard birds (22 chickens, 16 fighting cocks (FCs), 13 ducks and 1 goose) from four provinces (Ayutthaya, Nakhon Pathom, Pathum Thani and Kanchanaburi) in Thailand and processed for complete blood cell counts. Polymerase chain reaction (PCR) was performed for a partial cytochrome b gene from Leucocytozoon. Microscopic examinations revealed that 8 chickens and 13 ducks (21/52, 40%) were negative for blood parasites but 9 chickens and 15 FCs (24/52, 46%) were positive for Leucocytozoon spp. Three chickens and 7 FCs had mixed infections with microfilaria, Plasmodium/Haemoproteus spp. and Trypanosoma spp. There were no significant differences in the extensive hematological values among low rate (< 0.01% Leucocytozoon parasites), high rate (> 0.01% Leucocytozoon parasites) and mixed infections, except for the packed cell volume, hemoglobin concentration and fibrinogen concentration that were lower and for punctate reticulocytes that were higher in the high rate infections (p < 0.05). The information based on gametocytes and their host cells identified L. sabrasezi. In total, 24 PCR positive samples (both chickens and FCs) were divided into five groups based on four positions of 462 base pair amplicons without primer regions. Phylogenetic analysis showed that groups I–III were 99.1–99.8% similar and also closely related (98.0% similarity) to leucocytozoids isolated from chicken in Malaysia. Microscopy and molecular studies revealed similar morphology and phylogenetic groups of Leucocytozoon in both chickens and FCs.
