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Revista de Biología Tropical, ISSN: 2215-2075, Vol. 69(2): 615-625, April-June 2021 (Published May 14, 2021)

Do blood parasites increase immature erythrocytes

and mitosis in amphibians?

Leydy P. González

Carolina M. Vargas-León

Gustavo Andrés Fuentes-Rodríguez

Martha L. Calderón-Espinosa

Nubia E. Matta*

1. Departamento de Biología, Facultad de Ciencias, Universidad Nacional de Colombia, Grupo caracterización genética

e inmunología Sede Bogotá, Carrera 30 No 45-03, Bogotá, Colombia; lpgonzalezca@unal.edu.co,

gafuentesr@unal.edu.co, nemattac@unal.edu.co (Correspondence*)

2. Departamento de Microbiología. Facultad de Medicina, Universidad Nacional de Colombia, Sede Bogotá, Carrera 30

No 45-03, Bogotá, Colombia; cmvargasl@unal.edu.co

3. Instituto de Ciencias Naturales, Facultad de Ciencias, Universidad Nacional de Colombia, Sede Bogotá, Carrera 30

No 45-03, Bogotá, Colombia; mlcalderone@unal.edu.co

These authors contributed equally.

Received 18-I-2021. Corrected 22-IV-2021. Accepted 28-IV-2021.

Abstract. Introduction: In amphibians, blood may act as a hematopoietic tissue. However, the knowledge con-

cerning hematological features is scarce, there is not much information that allows an analysis about the possible

explanations of this physiological feature. Objective: This study aimed to evaluate the relationship between

immature red blood cells (RBCs) mitosis and the presence of blood parasites in amphibians. Methods: We

sampled 116 amphibians (31 species) in six Colombian localities. Blood was taken by cardiac puncture or maxil-

lary vein puncture. Smears were prepared, fixed, and Giemsa stained for microscopical analysis. The variables

analyzed were the percentage of immature RBCs, mitotic cells in peripheral blood, and blood parasite infection.

Data were analyzed using Wilcoxon’s rank test and exact Fisher statistical tests. Results: Sixty-two individu-

als showed mitosis in peripheral blood, and these mitotic RBCs shared morphological features with immature

RBCs. Overall, parasite prevalence was 30.1 %, distributed as follows: Trypanosoma (24.1 %), Hepatozoon-like

(6 %), Dactylosoma (4.3 %), Karyolysus-like (0.9 %), and Filarioidea (2.6 %). A positive association between

the percentage of immature RBCs and the presence of mitotic RBCs was found, and also between the blood

parasite infection and the percentage of immature RBCs. Conclusions: In this study, we found that the presence

of blood parasites, immature RBCs, and RBCs mitosis are frequent events in amphibians’ peripheral blood, and

our analysis suggests an association between those features. Thus, the release of immature RBCs and the mitosis

of those cells in peripheral blood may be a physiological response to blood parasite infection. Further studies

characterizing hematology in amphibians and wildlife, in general, are desirable.

Key words: anemia; Colombia; erythropoiesis; hemoparasites; RBC; peripheral blood.

González, L.P., Vargas-León, C.M., Fuentes-Rodríguez, G.A.,

Calderón-Espinosa, M.L., & Matta, N.E. (2021). Do blood

parasites increase immature erythrocytes and mitosis in

amphibians? Revista de Biología Tropical, 69(2), 615-625.

https://doi.org/10.15517/rbt.v69i2.45459

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Revista de Biología Tropical, ISSN: 2215-2075 Vol. 69(2): 615-625, April-June 2021 (Published May 14, 2021)

Amphibia is composed of three orders:

Caudata (salamanders and newts), Gymnophi-

ona (caecilians), and Anura (frogs and toads);

each has different organs associated with the

hematopoietic process. In Gymnophiona (like

Ichthyophis kohtaoensis), erythropoiesis and

thrombopoiesis are restricted to the spleen, and

granulocytopoiesis occurs in the liver (Zapata,

Gomariz, Garrido, & Cooper, 1982). For sala-

manders, information about the source of the

red blood cells is poor; bone marrow, at least

during their adult life, and organs like the liver

may act as secondary hematopoietic organs

(Arikan & Çiçek, 2014). In frogs and toads,

there is no consensus about the hematopoietic

organs. Nonetheless, the liver, spleen, kidney,

thymus, and bone marrow are suggested as the

main hematopoietic organs (Jordan & Speidel

1930; Glomski, Tamburlin, Hard, & Chainani,

1997; Cumano & Godin, 2007; Akulenko,

2012). During the tadpole stage, the kidney is

the organ involved in the hematopoiesis pro-

cess (Jordan & Speidel, 1930; Arikan & Cicek,

2014). This characteristic may be species-

dependent and could be associated with meta-

morphosis and the environmental shift during

their life-time. In Xenopus laevis, the aquatic

toad, vascularization in bone marrow is rudi-

mentary. In this species, erythropoiesis occurs

in the liver (Nogawa-Kosaka et al., 2011; Okui

et al., 2013), and myelopoiesis is restricted to

the bone marrow (Yaparla, Reeves, & Grayfer,

2020). In terrestrial amphibians, as Lithobates

catesbeianus, the bone marrow vasculariza-

tion is more complex, similar to mammalian

vascularization (Tanaka, 1976). In this species,

erythropoiesis does not occur in the liver or

spleen (Cumano & Godin, 2007) but in bone

marrow, and the kidney (de Abreu Manso, de

Brito-Gitirana, & Pelajo-Machado, 2009).

Amphibian red blood cells (RBCs) are

nucleated, as in fish, reptiles, and birds.

Amphibian RBCs’ lifespans range from 200

to 1 400 days (Altland & Brace, 1962); their

RBCs (mainly in salamanders) are the largest

among vertebrates, e.g., Amphiuma tridactylum

RBCs sizes are approximately 70 μm length

and 40 μm width. In contrast, frogs and toads,

have the smallest RBCs of amphibians, 22

μm length and 15 μm width on average (Mit-

suru, 1981; Claver & Quaglia, 2009; Arikan &

Cicek, 2014).

Red blood cell maturation in peripheral

blood has been reported in other vertebrates

such as Cyclostomi, Chondrichthyes, Teleosts

(Glomski et al., 1997), as well as in amphib-

ians like Pelophylax saharicus, Bufo bufo,

Epidalea calamita, Bufotes viridis, and Xeno-

pus laevis (Plum, 1953; Thomas & Maclean,

1974; Bouhafs, Berrebbah, Devaux, Rouabhi,

& Djebar, 2009). This could be accompa-

nied by mitosis of immature RBCs (Dawson,

1930), but it is an unusual phenomenon that

has been barely reported in some amphibians,

reptiles, and occasionally in birds. Seasonal

changes and heavy metal contamination can

induce RBC maturation in peripheral blood

and immature RBCs’ mitosis (Bouhafs et al.,

2009; Akulenko, 2012; González-Mille et al.,

2019). Other factors that may be related to the

increase of immature RBCs in peripheral blood

are the reduction of oxygen levels due to ane-

mia, hemolysis, or hypoxia; these conditions

promote a regenerative physiological response

that increases the RBCs count (Martinho, 2012;

Maceda-Veiga et al., 2015; Dissanayake et

al., 2017). Thomas and Maclean (1974) and

Nogawa-Kosaka et al. (2011) showed that, after

anemia induction, Xenopus laevis increases the

immature RBCs in peripheral blood by raising

the erythropoietin levels, and in newts (Fam-

ily: Salamandridae), spleen ablation could be

a triggering factor for this too (Dawson, 1933).

Amphibians are commonly infected by

intracellular blood parasites like Dactylosoma,

Hepatozoon, Hemolivia, or Karyolysus (Petit,

Landau, Baccam, & Lainson, 1990; Barta,

1991; Haklová-Kočíková et al., 2014; Nether-

lands, Cook, & Smit, 2014) and extracellular

blood parasites such as Filarioidea and Try-

panosoma (Desser, 2001; Žičkus 2002; Ferreira

et al., 2015; Nguete, Wondji, Pone, & Mpoame,

2019). Parasitic infection by Plasmodium and

Hepatozoon, among others, may induce ane-

mia in reptiles, birds, and amphibians (Schall,

2002; Vardo-Zalik & Schall, 2008; Saggese,

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2009; Motz, Lewis, & Vardo-Zalik, 2014;

Forzán, Heatley, Russell, & Horney, 2017;

Stijlemans, De Baetselier, Magez, Van Ginder-

achter, & De Trez, 2018).

In this study, we describe the presence

of mitosis in the peripheral blood of amphib-

ians from different Colombian localities and

evaluate the possible association of this pro-

cess with the increase of immature RBCs in

peripheral blood and the presence of blood

parasites. We hypothesize that infection by

blood parasites may influence the presence of

mitosis in peripheral blood since some blood

parasites could induce anemia in their hosts,

triggering an increase of immature RBCs in

the peripheral blood where they mature and

carry out mitosis. This is the first study about

the potential influence of blood parasites on

hematopoiesis in peripheral blood in several

wild species of anurans occurring in Andean,

pacific and Amazonian regions in Colombia.

Besides, it is the study, around this topic, with

the largest number of species sampled in the

world. Not leaving aside, that this topic has not

been treated for several years.

MATERIALS AND METHODS

Sampling: A total of 116 amphibians (31

species) blood smears were analyzed (Table 1).

Blood was withdrawn by maxillary vein punc-

ture or by cardiac puncture just after euthana-

sia (American Veterinary Medical Association,

2020), carried out for taxonomic purposes.

Blood smears (two or three replicas per indi-

vidual) were fixed with methanol for five

minutes and stained with 4 % Giemsa (pH 7.2)

for 45 minutes (Valkiūnas, 2005). Six localities

in Colombia were sampled: San José del Gua-

viare-Guaviare (N = 6 individuals sampled),

Tumaco-Nariño (N = 8), Santa María-Boyacá

(N = 8), Medina-Cundinamarca (N = 51), San

Gil-Santander (N = 15) and the campus of the

Universidad Nacional de Colombia-Bogotá (N

= 28), all sampled individuals are specified

in the Digital Appendix. Smears were depos-

ited into the biological collection GERPH of

the Universidad Nacional de Colombia. All

animal procedures were conducted with the

Bioethics Committee’s approval, Fundación

Universitaria Internacional del Trópico Amer-

icano-Unitrópico (Act May 18, 2020), and the

Science Faculty’s Ethics Committee, Univer-

sidad Nacional de Colombia (Act 06, 2019).

This investigation was developed following

the Colombian Congress’ 84 th law of 1989,

which is the current national statute for animal

protection, and the resolution 8 430 of 1993

from the Ministry of Health, which regulates

the biomedical investigation with animals.

Blood smear examination: smears were

examined and photographed using an Olym-

pus CX41 microscope (Olympus Corporation,

Tokyo, Japan), equipped with an integrat-

ed camera and a Leica DM750e microscope

(Leica Microsystems, Heerbrugg, Switzerland),

equipped with a Leica EC3 digital camera. The

parasites identified were classified as extra-

and intracellular and identified to the genus

level. There is no established protocol for the

estimation of immature RBCs in amphibians.

We obtained the percentage of immature RBCs

by counting 50 ideal fields at x400 magnifica-

tion; each field had an average of 100 RBCs

for approximately 5 000 RBCs; it represents a

modification of the method described by Col-

licutt, Grindem, and Neel (2012). For parasite

detection the whole blood smear and all rep-

licas were screened, then the parasitemia was

estimated as the number of parasites on 10 000

RBCs, for intracellular parasites, and for extra-

cellular parasites as the number of parasites on

100 fields (Valkiūnas, 2005; Benedikt, Barus,

Capek, Havlicek, & Literak, 2009).

Statistical analysis: Statistical analysis

was carried out using the R commander (Fox &

Bouchet-Valat, 2019) package for R software

(R Core Team, 2020). Variables evaluated were:

the presence or absence of mitosis in peripheral

blood, the percentage of immature RBCs, the

presence or absence of blood parasites, and the

type of parasite. A Kolmogorov-Smirnov test

was used to evaluate the normal distribution of

the data. A common feature of the data was a

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non-normal distribution, so a Wilcoxon’s rank

test for two variables was calculated to com-

pare quantitative variables, and a Fisher exact

test was used to compare qualitative variables.

For the hypothesis test, P values less than 0.05

were considered significant.

RESULTS

A total of 116 amphibia were analyzed;

53.5 % of the samples showed mitotic cells in

different phases in the peripheral blood (Fig.

1). The mitotic index observed was low; over-

all, less than two mitotic cells per thousand

RBCs. The prevalence of blood parasites in the

sample was 30.1 %, being 70.3 % with single

infections and 29.7 % with mixed infections.

The identified blood parasites were Trypanoso-

ma 24.1 % (28/116), Hepatozoon-like (Named

as Hepatozoon-like and Karyolysus-like due to

the lack of molecular diagnosis that does not

allow accurate classification of those parasites)

TABLE 1

Amphibian species included in this study, common name, sampling location,

and N (number of individuals sampled per species) are depicted

Family Species English name N

Microhylidae

Elachistocleis ovalis (Schneider, 1799)

Narrow-mouthed frog

Ranidae

Lithobates palmipes (Spix, 1824)

Amazon Waterfrog

Brachycephaloidea

Pristimantis cf. savagei (Pyburn & Lynch, 1981)

Pyburn’s Robber Frog

Pristimantis vilarsi (Melin, 1941)

Rio Uaupes Robber Frog

Pristimantis sp.

Rhaebo glaberrimus (Günther, 1868)

Cundinamarca Toad

Rhinella gr. margaritifera (Laurenti, 1768)

Rhinella beebei (Gallardo, 1965)

North Coastal Granular Toad

Rhinella marina (Linnaeus, 1758)

3, 4

South American Cane Toad

Hylidae

Boana lanciformis (Cope, 1870)

Rocket Treefrog

Boana boans (Linnaeus, 1758)

Giant Gladiator Treefrog

Boana xerophylla (Duméril & Bibron, 1841)

Emerald-eyed Treefrog

Boana maculateralis (Caminer and Ron, 2014)

Stained Treefrog

Boana pellucens (Werner, 1901)

Palm Treefrog

Boana rosenbergi (Boulenger, 1898)

Rosenberg’s Gladiator Frog

Dendropsophus minutus (Peter 1872)

Lesser Treefrog

Scinax elaeochroa (Cope, 1875)

Olive Snouted Treefrog

Scinax quinquefasciatus (Fowler, 1913)

Fowler’s Snouted Treefrog

Scinax rostratus (Peters, 1863)

Caracas Snouted Treefrog

Scinax ruber (Laurenti, 1768)

Common Snouted Treefrog

Smilisca phaeota (Cope, 1862)

New Granada Cross-banded Treefrog

Sphaenorhynchus lacteus (Daudin, 1800)

Orinoco Lime Treefrog

Trachycephalus jordani (Stejneger & Test, 1891)

Jordan’s Casque-headed Treefrog

Dendropsophus molitor (Schimdt, 1857)

Green Dotted Treefrog

Leptodactylidae

Adenomera hylaedactyla (Cope 1868)

Napo Tropical Bullfrog

Physalaemus fischeri (Boulenger, 1890)

Fischer’s Dwarf Frog

Engystomops pustulosus (Cope, 1864)

Túngara Frog

Leptodactylus colombiensis (Heyer, 1994)

Leptodactylus fuscus (Schneider, 1799)

Rufous frog

Leptodactylus ventrimaculatus (Boulenger, 1902)

Spotted-vented Thin-toed Frog

Lithodytes lineatus (Schneider, 1799)

Painted Antnest Frog

Sampling location:

Guaviare,

Boyacá,

Cundinamarca,

Santander,

Nariño.

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6 % (7/116), Dactylosoma 4.3 % (5/116),

Karyolysus-like

0.9 % (1/116), and Filarioidea

2.6 % (3/116) (Fig. 2; Digital Appendix). The

percentage of immature RBCs in individu-

als with mitosis ranged between 0.86-80.08

% (15.76 ± 15.99), while individuals without

mitosis had percentages less than 8.98 % (2.1

± 2.3) (Digital Appendix). All the infected

samples had parasitemias that ranged between

0.01 and 3 %, except for one Rhinella beebei

whose parasitemia for Dactylosoma sp. was 16

% (Digital Appendix). Given that most of the

samples were collected at low altitudes (75.9

% of the samples were collected between 0 and

1 117 m.a.s.l; Digital Appendix) and some spe-

cies have a low number of individuals sampled

(e.g., Lithodytes lineatus N = 2), there was no

possibility to statistically analyze a tendency

of parasitic altitudinal distribution nor the

host species and its association with mitosis in

peripheral blood.

Percentage of immature RBCs and

mitosis: By carrying out a morphological com-

parison between cells in mitosis and immature

RBCs, some standard features were found:

both cell types showed a roundish form and

a basophilic cytoplasm, as demonstrated by

the Giemsa stain (Fig. 1). Due to these mor-

phological similarities and literature reports,

we propose that those mitotic processes may

be occurring in immature cells, thereby, an

increase in the percentage of immature RBCs

in peripheral blood could be related to the pres-

ence of mitotic cells. Comparing samples that

show mitosis with those without mitosis, using

a Wilcoxon’s rank test, a significant difference

in the percentage of immature cells in periph-

eral blood was found (P < 0.0001).

Percentage of immature RBCs and

blood parasites: The comparison of the per-

centage of immature RBCs between samples

with a positive and negative diagnosis for blood

parasites also showed a significant difference

(Wilcoxon’s rank test, P < 0.001). However, the

percentage of parasitemia and immature RBCs

did not correlate (data not shown).

Mitosis and blood parasites: An asso-

ciation between mitosis and blood parasites

were assessed; 25 out of 35 infected samples

show mitosis, and by applying a Fisher exact

test, we identified an association between the

Fig. 1. Phases of mitosis and immature RBCs observed in peripheral blood smears of Colombian amphibians included in

the study. A. Mitotic cell in prophase; B. Mitotic cell in metaphase; C. Mitotic cell in anaphase; D. Mitotic cell in telophase;

E-H. Immature Red blood cells at different maturation stages. Giemsa stain. Scale bar: 10 μm.

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infection by blood parasites and the presence

of mitosis in peripheral blood (χ

= 12.46 and

P < 0.0001); although, there is no association

between parasitemia and presence of mitosis

(Wilcoxon’s rank test, P > 0.05).

DISCUSSION

There are limited reports on erythrocyt-

ic mitosis in amphibian’s peripheral blood

(Thomas & Maclean, 1974; Glomski et al.,

1997). This is the first report of this subject in

Colombia and for the species analyzed here; it

also represents the study of erythrocytic mitosis

in the largest sample of amphibians. Our results

evidentiate how often this phenomenon occurs

in amphibians and discuss its possible causes.

Previous reports have shown that mitotic

RBCs in peripheral blood occur in immature

RBCs, but not in mature RBCs (Chegini,

Aleporou, Bell, Hilder, & Maclean, 1979).

Our results also show that mitosis is present

in immature RBCs due to the association evi-

denced between the presence of mitosis and

the percentage of immature RBCs in peripheral

blood and the morphological features shared

between them (Fig. 1). The presence of a high

number of immature RBCs at different stages

of maturation (as determined by their baso-

philic cytoplasm, roundish form, nucleus occu-

pying the best part of the cellular body, and the

less condensed chromatin) (Fig. 1) is an indica-

tor of active erythropoiesis (Crouch & Kaplow,

1985) that can be triggered by respiratory stress

or anemia (Nogawa-Kosaka et al., 2011).

The presence of blood parasites has been

associated with physiological conditions, such

as anemia (Saggese, 2009), and a regenerative

Fig. 2. Blood parasites infecting Colombian amphibians analyzed in the study A-C. Trypanosoma; D. Microfilaria; E-G.

Hepatozoon-like; H-I. Karyolysus-like; J-L. Dactylosoma. Giemsa stain. Scale bar: 10 μm; Differences in the sizes of RBCs

are due to their belonging to different host species.

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response to this stress induces the early release

of immature RBCs to peripheral blood. Our

results suggest that this phenomenon is accom-

panied by mitosis of these immature RBCs in

peripheral blood in amphibians. Regenerative

anemia has been shown to induce increased

immature RBCs in birds (Campbell, 2004),

reptiles (Saggese, 2009), and fish (Clauss,

Dove, & Arnold, 2008). The data obtained here

do not allow us to determine the presence of

anemia in the sampled animals because of the

absence of a physical evaluation of them and

the lack of hemoglobin data concentrations.

Nonetheless, the high percentage of immature

RBCs found in the organisms allows us to con-

sider that perhaps anemia was present in the

individuals sampled since the presence of such

cells in peripheral blood and anemia have been

correlated before (Thomas & Maclean, 1974;

Saggese, 2009).

Blood parasites were found infecting 30.1

% of the sampled individuals with parasit-

emias ranged between 0.01 and 16 % (Digital

Appendix). Trypanosoma was the most preva-

lent genus found, infecting 24.1 % of the ani-

mals sampled, while Filarioidea was the less

prevalent type of parasite (2.6 %). It is also

important to highlight the diversity of intra-

cellular parasites found, parasites tentatively

belonging to the genus Hepatozoon, Dactylo-

soma, and Karyolisus, which were diagnosed

by microscopic analysis. Amphibians are a

group of vertebrates highly infected by para-

sites, bacteria, fungus, and viruses; due to their

habits, which often combine terrestrial and

aquatic environments, they are usually exposed

to different conditions that ease those infec-

tions. Additionally, their habits, for example,

promote the interaction with hematophagous

insects and leeches, both vectors for the trans-

mission of different blood parasites (Ferreira,

Perles, Machado, Prado, & André, 2020). This

study presents some insights regarding blood

parasite prevalence and diversity in Colombian

amphibians, although it is important to com-

plement this information reported by micro-

scopic analysis with molecular approaches

that allow a complete characterization of the

parasites found.

Some reports in lizards show the pres-

ence of high numbers of immature RBCs in

peripheral blood associated with blood parasite

infections (Martínez-Silvestre, Mateo, Silveira,

& Bannert, 2001; Martinez-Silvestre & Arri-

bas, 2014). Intracellular blood parasites, like

Hepatozoon, Dactylosoma, Karyolysus, and

Plasmodium, may be related to anemia due to

the disruption of the RBCs caused by some

of the parasites’ life stages. This phenomenon

has been reported in several species like Sce-

loporus occidentalis and other lizards (Schall

1982; Barta, 1991; Peirce & Adlard, 2004).

Extracellular parasites, like Trypanosoma or

Filarioidea, are associated with a decrease in

RBCs count, hematocrit and hemoglobin levels

(Maqbool & Ahmed, 2016), inflammation, and

tissue degeneration of skeletal heart muscle in

Australian mammals (Thompson, Godfrey, &

Thompson, 2014). Trypanosoma experimen-

tal infection has been associated with food

refusal resulting in death in European green

frogs and Canadian frogs (Reichenbach-Klink

& Elkan, 1965). Extracellular hemoparasitic

infections have also been associated with ane-

mia (Amole, Clarkson, & Shear 1982; Silva,

Herrera, Domingos, Ximenes, & Dávila, 1995;

Stijlemans et al., 2018).

Our possible explanation for the pres-

ence of mitotic cells in peripheral blood in

an infected organism is that those parasitic

organisms could induce anemia in their host.

As a response, immature RBCs are released to

the peripheral blood. Those cells would finish

their maturation in the peripheral blood and

could divide to increase the number of RBCs

to offset anemia. This explanation could be

supported by the association found between the

presence of mitotic RBCs and the percentage of

immature RBCs in peripheral blood, and by the

association between the percentage of imma-

ture RBCs and the presence of blood parasites.

Further research based on experimental

trials is needed to confirm the hypothesis here

proposed and to evaluate other factors that can

also induce similar physiological responses to

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heavy metal pollutants, antifungals, or other

toxic agents (Preetpal, 2014).

Ethical statement: authors declare that

they all agree with this publication and made

significant contributions; that there is no con-

flict of interest of any kind; and that we fol-

lowed all pertinent ethical and legal procedures

and requirements. All financial sources are

fully and clearly stated in the acknowledge-

ments section. A signed document has been

filed in the journal archives.

ACKNOWLEDGMENTS

This study was supported by the “Min-

isterio de Ciencia, Tecnología e Innovación”,

previously named “Colciencias”, by the proj-

ect code No 1101-776-57872, and the special

cooperation agreement No 80740-287-2019.

The authors wish to thank the members of

the GERPH group, especially Andres Felipe

Aponte, for fieldwork, and Juan José Rubio

for the statistical orientation. We also want to

extend our acknowledgment to the anonymous

reviewers of this paper, because of their valu-

able comments that contributed to the article.

RESUMEN

¿Causan los parásitos sanguíneos un aumento en los

eritrocitos inmaduros y la mitosis en los anfibios?

Introducción: En anfibios, la sangre puede actuar

como un tejido hematopoyético. Sin embargo, el cono-

cimiento acerca de las características hematológicas es

escaso y no hay información que permita un análisis acerca

de las posibles explicaciones a este rasgo fisiológico Obje-

tivo: La intención de este estudio fue evaluar la relación

entre la presencia de eritroblastos, mitosis de glóbulos rojos

(GRs) y la infección por hemoparásito en sangre periférica

de anfibios. Métodos: Se muestrearon 116 anfibios (31

especies) en seis localidades de Colombia. Se tomaron

muestras de sangre mediante punción cardiaca o punción

a la vena maxilar. Se prepararon extendidos sanguíneos,

se fijaron y tiñeron con Giemsa para su posterior análisis

por microscopía. Se analizaron variables como porcentaje

de GRs inmaduros, células mitóticas en sangre periférica e

infección por hemoparásitos. Los datos fueron analizados

mediante el test de rango de Willcoxon y el test exacto de

Fisher. Resultados: sesenta y dos individuos evidenciaron

mitosis en sangre periférica y dichas mitosis compartían

características morfológicas con GRs inmaduros. La pre-

valencia general de parásitos fue del 30.1 %, distribuido de

la siguiente forma: Trypanosoma (24.1 %), Hepatozoon-

like (6 %), Dactylosoma (4.3 %), Karyolysus-like (0.9

%), y Filarioidea (2. 6 %). Hay una asociación positiva

entre el porcentaje de GRs inmaduros y la presencia de

células mitóticas, también se encontró una relación entre

la infección por hemoparásitos y el porcentaje de GRs

inmaduros. Conclusiones: En este estudio encontramos

que la presencia de parásitos sanguíneos, GRs inmaduros y

mitosis de GRs son eventos frecuentes en sangre periférica

de anfibios, y nuestros resultados sugieren una asociación

entre dichas características. Por tanto, la liberación de GRs

inmaduros y la mitosis de estas células en sangre periférica

podría ser una respuesta fisiológica a infecciones parasita-

rias. Posteriores estudios que caractericen la hematología

en anfibios y en vida silvestre en general, son deseables.

Palabras clave: anemia; Colombia; eritropoyesis; hemo-

parásitos; glóbulos rojos; sangre periférica.

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