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Ševčík R, Mahlerová K, Riera FA, Zárybnická M. Leucocytozoon Infection Does Not Influence the Survival of Boreal Owl Aegolius funereus Nestlings. Avian Dis 2024; 68:134-140. [PMID: 38885055 DOI: 10.1637/aviandiseases-d-23-00063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 04/04/2024] [Indexed: 06/20/2024]
Abstract
Leucocytozoon infection has been observed to impact the reproductive ecology and physiology of avian hosts, but its influence on nestling survival remains unclear. We investigated the effect of Leucocytozoon infection intensity, determined through triplicate PCR sample analyses, on the survival of 256 boreal owl (Aegolius funereus) nestlings during an 8-yr study. Contrary to our expectations, the survival probability of boreal owl nestlings was not influenced by their Leucocytozoon infection intensity. Nestling age and Leucocytozoon infection intensity in male and female parents also did not impact nestling survival. Instead, food abundance and hatching order were the key factors influencing nestling survival. Additionally, we observed a significantly higher Leucocytozoon infection intensity in male parents compared to female parents and nestlings. We suggest a distinct division of parental roles may lead females and nestlings staying within the nest boxes (cavities) to experience lower exposure to potential vectors transmitting blood parasites than their male counterparts. Our study shows that Leucocytozoon disease may not be lethal for boreal owl chicks, exhibiting a below-average infection intensity compared to their male parents.
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Affiliation(s)
- Richard Ševčík
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, 165 00, Czech Republic
- Forestry and Game Management Research Institute, 252 02 Jíloviště, Czech Republic
| | - Karolina Mahlerová
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, 165 00, Czech Republic
| | - Fernando A Riera
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, 165 00, Czech Republic
| | - Markéta Zárybnická
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, 165 00, Czech Republic,
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Yan WL, Sun HT, Zhao YC, Hou XW, Zhang M, Zhao Q, Elsheikha HM, Ni HB. Global prevalence of Plasmodium infection in wild birds: A systematic review and meta-analysis. Res Vet Sci 2024; 168:105136. [PMID: 38183894 DOI: 10.1016/j.rvsc.2024.105136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/28/2023] [Accepted: 01/01/2024] [Indexed: 01/08/2024]
Abstract
Avian malaria is a vector-borne parasitic disease caused by Plasmodium infection transmitted to birds by mosquitoes. The aim of this systematic review was to analyze the global prevalence of malaria and risk factors associated with infection in wild birds. A systematic search of the databases CNKI, WanFang, VIP, PubMed, and ScienceDirect was performed from database inception to 24 February 2023. The search identified 3181 retrieved articles, of which 52 articles met predetermined inclusion criteria. Meta-analysis was performed using the random-effects model. The estimated pooled global prevalence of Plasmodium infection in wild birds was 16%. Sub-group analysis showed that the highest prevalence was associated with adult birds, migrant birds, North America, tropical rainforest climate, birds captured by mist nets, detection of infection by microscopy, medium quality studies, and studies published after 2016. Our study highlights the need for more understanding of Plasmodium prevalence in wild birds and identifying risk factors associated with infection to inform future infection control measures.
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Affiliation(s)
- Wei-Lan Yan
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao 266109, Shandong Province, PR China; College of Life Science, Changchun Sci-Tech University, Shuangyang 130600, Jilin Province, PR China
| | - He-Ting Sun
- Center of Prevention and Control Biological Disaster, State Forestry and Grassland Administration, Shenyang 110034, Liaoning Province, PR China
| | - Yi-Chen Zhao
- Academy of Forestry Inventory and Planning, National Forestry and Grassland Administration, Beijing 100714, PR China
| | - Xin-Wen Hou
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao 266109, Shandong Province, PR China
| | - Miao Zhang
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao 266109, Shandong Province, PR China
| | - Quan Zhao
- College of Life Science, Changchun Sci-Tech University, Shuangyang 130600, Jilin Province, PR China.
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, UK.
| | - Hong-Bo Ni
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao 266109, Shandong Province, PR China
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Chagas CRF, Duc M, Gutiérrez-Liberato GA, Valkiūnas G. Host Cells of Leucocytozoon (Haemosporida, Leucocytozoidae) Gametocytes, with Remarks on the Phylogenetic Importance of This Character. Pathogens 2023; 12:pathogens12050712. [PMID: 37242382 DOI: 10.3390/pathogens12050712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/06/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
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.
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Affiliation(s)
| | - Mélanie Duc
- Nature Research Centre, 01109 Vilnius, Lithuania
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Valkiūnas G, Iezhova TA. Insights into the Biology of Leucocytozoon Species (Haemosporida, Leucocytozoidae): Why Is There Slow Research Progress on Agents of Leucocytozoonosis? Microorganisms 2023; 11:1251. [PMID: 37317225 DOI: 10.3390/microorganisms11051251] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 06/16/2023] Open
Abstract
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.
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