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Epidemiological traits of the malaria-like parasite Polychromophilus murinus in the Daubenton's bat Myotis daubentonii.

Witsenburg F, Schneider F, Christe P - Parasit Vectors (2014)

Bottom Line: Yet most of these studies provide only snapshots in time of the parasites discovered.During one year, we additionally measured body temperature and haematocrit values.Confusion over the identities and nomenclature of malarial-like parasites requires that molecular barcodes are coupled to accurate morphological descriptions.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology and Evolution, University of Lausanne, Biophore, CH-1015, Lausanne, Switzerland. fardo.witsenburg@unil.ch.

ABSTRACT

Background: The great diversity of bat haemosporidians is being uncovered with the help of molecular tools. Yet most of these studies provide only snapshots in time of the parasites discovered. Polychromophilus murinus, a malaria-like blood parasite, specialised on temperate-zone bats is a species that is being 'rediscovered'. This study describes the infection dynamics over time and between host sex and age classes.

Methods: For three years we followed the members of three breeding colonies of Myotis daubentonii in Western Switzerland and screened them for the prevalence and parasitemia of P. murinus using both molecular tools and traditional microscopy. In order to identify more susceptible classes of hosts, we measured, sexed and aged all individuals. During one year, we additionally measured body temperature and haematocrit values.

Results: Juvenile bats demonstrated much higher parasitemia than any other age class sampled, suggesting that first exposure to the parasite is very early in life during which infections are also at their most intense. Moreover, in subadults there was a clear negative correlation between body condition and intensity of infection, whereas a weak positive correlation was observed in adults. Neither body temperature, nor haematocrit, two proxies used for pathology, could be linked to intensities of infection.

Conclusion: If both weaker condition and younger age are associated with higher infection intensity, then the highest selection pressure exerted by P. murinus should be at the juvenile stage. Confusion over the identities and nomenclature of malarial-like parasites requires that molecular barcodes are coupled to accurate morphological descriptions.

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Related in: MedlinePlus

Images ofPolychromophilus murinusgametocytes inMyotis daubentoniierythrocytes. (A-D) Different maturation stages of a gametocyte; (E) Mature male, microgametocyte with leucocyte; (F) Mature female, macrogametocyte; (G) Mature female, macrogametocyte, phase-contrast filter. Images A-F 600x magnification, image G 1000x magnification.
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Fig1: Images ofPolychromophilus murinusgametocytes inMyotis daubentoniierythrocytes. (A-D) Different maturation stages of a gametocyte; (E) Mature male, microgametocyte with leucocyte; (F) Mature female, macrogametocyte; (G) Mature female, macrogametocyte, phase-contrast filter. Images A-F 600x magnification, image G 1000x magnification.

Mentions: P. murinus gametocytes were detected in 58 blood smears (Figure 1). Gametocytes were large (Table 1), round to oval shaped, with a maximal diameter concurring with the described 6-8 μm [1]. Mature gametocytes would practically fill up the host cell, leaving mainly the edge of the host cell visible. This follows the description of Garnham [1], yet Landau et al. [17] mention that they do not completely fill up the host cell, but how much of the host lumen remains is not mentioned. The pigments are mouse-dropping shaped and of an irregular size, irregularly distributed across the cell; these clusters of pigments made counting them an ambiguous task and pigment numbers (Table 1) should therefore be taken with due caution.Figure 1


Epidemiological traits of the malaria-like parasite Polychromophilus murinus in the Daubenton's bat Myotis daubentonii.

Witsenburg F, Schneider F, Christe P - Parasit Vectors (2014)

Images ofPolychromophilus murinusgametocytes inMyotis daubentoniierythrocytes. (A-D) Different maturation stages of a gametocyte; (E) Mature male, microgametocyte with leucocyte; (F) Mature female, macrogametocyte; (G) Mature female, macrogametocyte, phase-contrast filter. Images A-F 600x magnification, image G 1000x magnification.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4269171&req=5

Fig1: Images ofPolychromophilus murinusgametocytes inMyotis daubentoniierythrocytes. (A-D) Different maturation stages of a gametocyte; (E) Mature male, microgametocyte with leucocyte; (F) Mature female, macrogametocyte; (G) Mature female, macrogametocyte, phase-contrast filter. Images A-F 600x magnification, image G 1000x magnification.
Mentions: P. murinus gametocytes were detected in 58 blood smears (Figure 1). Gametocytes were large (Table 1), round to oval shaped, with a maximal diameter concurring with the described 6-8 μm [1]. Mature gametocytes would practically fill up the host cell, leaving mainly the edge of the host cell visible. This follows the description of Garnham [1], yet Landau et al. [17] mention that they do not completely fill up the host cell, but how much of the host lumen remains is not mentioned. The pigments are mouse-dropping shaped and of an irregular size, irregularly distributed across the cell; these clusters of pigments made counting them an ambiguous task and pigment numbers (Table 1) should therefore be taken with due caution.Figure 1

Bottom Line: Yet most of these studies provide only snapshots in time of the parasites discovered.During one year, we additionally measured body temperature and haematocrit values.Confusion over the identities and nomenclature of malarial-like parasites requires that molecular barcodes are coupled to accurate morphological descriptions.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology and Evolution, University of Lausanne, Biophore, CH-1015, Lausanne, Switzerland. fardo.witsenburg@unil.ch.

ABSTRACT

Background: The great diversity of bat haemosporidians is being uncovered with the help of molecular tools. Yet most of these studies provide only snapshots in time of the parasites discovered. Polychromophilus murinus, a malaria-like blood parasite, specialised on temperate-zone bats is a species that is being 'rediscovered'. This study describes the infection dynamics over time and between host sex and age classes.

Methods: For three years we followed the members of three breeding colonies of Myotis daubentonii in Western Switzerland and screened them for the prevalence and parasitemia of P. murinus using both molecular tools and traditional microscopy. In order to identify more susceptible classes of hosts, we measured, sexed and aged all individuals. During one year, we additionally measured body temperature and haematocrit values.

Results: Juvenile bats demonstrated much higher parasitemia than any other age class sampled, suggesting that first exposure to the parasite is very early in life during which infections are also at their most intense. Moreover, in subadults there was a clear negative correlation between body condition and intensity of infection, whereas a weak positive correlation was observed in adults. Neither body temperature, nor haematocrit, two proxies used for pathology, could be linked to intensities of infection.

Conclusion: If both weaker condition and younger age are associated with higher infection intensity, then the highest selection pressure exerted by P. murinus should be at the juvenile stage. Confusion over the identities and nomenclature of malarial-like parasites requires that molecular barcodes are coupled to accurate morphological descriptions.

Show MeSH
Related in: MedlinePlus