First evidence for development of Plasmodium relictum (Grassi and Feletti, 1891) sporozoites in the salivary glands of Culex modestus Ficalbi, 1889

• Published in: Parasitology research (1987) Vol. 122; no. 7; pp. 1689 - 1693
• Main Authors: Dimitrov, Dimitar, Bobeva, Aneliya, Marinov, Martin P., Ilieva, Mihaela, Zehtindjiev, Pavel
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-07-2023; Springer; Springer Nature B.V
• Subjects: Analysis; Biomedical and Life Sciences; Biomedicine; Birds; Brief Report; Carbon dioxide; Culex modestus; Culicidae; Disease transmission; Ethylenediaminetetraacetic acid; Host-parasite interactions; Immunology; Infection; Malaria; Medical Microbiology; Microbiology; Mosquitoes; Oocysts; Parasites; Plasmodium relictum; Salivary gland; Scientific equipment and supplies industry; Sporogony; Sporozoites; Vectors; Zygotes; United States; Avian malaria; Competent vector; Blood parasites; SGS1; Transmission; Parus major
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-023-07853-z

The competence of insect vectors to transmit diseases plays a key role in host-parasite interactions and in the dynamics of avian malaria and other haemosporidian infections (Apicomplexa, Haemosporida). However, the presence of parasite DNA in the body of blood-sucking insects does not always constitute evidence for their competence as vectors. In this study, we investigate the susceptibility of wild-caught mosquitoes (
Culex
spp.) to complete sporogony of
Plasmodium relictum
(
cyt b
lineage SGS1) isolated from great tits (
Parus major
L., 1758). Adult female mosquitoes were collected with a CO
2
bait trap overnight. A set of 50 mosquitoes was allowed to feed for 3 h at night on a single great tit infected with
P. relictum
. This trial was repeated on 6 different birds. The bloodfed mosquitoes that survived (
n
= 68) were dissected within 1–2 days (for ookinetes,
n
= 10) and 10–33 days post infection (for oocysts and sporozoites,
n
= 58) in order to confirm the respective parasite stages in their organs. The experiment confirmed the successful development of
P. relictum
(
cyt b
lineage SGS1) to the stage of sporozoites in
Culex pipiens
L., 1758 (
n
= 27) and in
Culex modestus
(
n
= 2). Our study provides the first evidence that
C. modestus
is a competent vector of
P. relictum
isolated from great tits, suggesting that this mosquito species could also play a role in the natural transmission of avian malaria.