The biology of malarial parasite in the mosquito: a review

Simonetti, Amauri Braga

doi:10.1590/s0074-02761996000500001

Cited by 27 publications

(36 citation statements)

References 255 publications

(235 reference statements)

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“…Sporozoites are released from mature oocysts located between the midgut epithelium and the basal lamina, over a 3-4 day period, usually occurring between 10 and 14 days after the mosquitoes have received an infective bloodmeal ( [1]). During this time, the parasites [2] and their major surface protein [3] are found adherent to salivary glands as well as to the mid and hindgut, alary muscles, ovaries, Malpighian tubules, and the crop.…”

Section: Introductionmentioning

confidence: 99%

Anopheles stephensi salivary glands bear receptors for region I of the circumsporozoite protein of Plasmodium falciparum

Sidjanski

Vanderberg

Sinnis

1997

Molecular and Biochemical Parasitology

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In the mosquito, Plasmodium sporozoites rupture from oocysts found on the midgut wall, circulate in the hemolymph and invade salivary glands where they wait to be injected into a vertebrate host during a bloodmeal. The mechanisms by which sporozoites specifically attach to and invade salivary glands are not known but evidence suggests that it is a receptor-mediated process. Here we show that the major surface protein of sporozoites, the circumsporozoite protein (CS), binds preferentially to salivary glands when compared to other organs exposed to the circulating hemolymph. In addition, we show that a peptide encompassing region I, a highly conserved sequence found in all rodent and primate Plasmodium CS proteins, inhibits binding of CS to mosquito salivary glands.

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Section: Introductionmentioning

confidence: 99%

Anopheles stephensi salivary glands bear receptors for region I of the circumsporozoite protein of Plasmodium falciparum

Sidjanski

Vanderberg

Sinnis

1997

Molecular and Biochemical Parasitology

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“…To identify and evaluate each factor controlling these processes is a challenge that could lead to a better understanding of this complex biologic event. These factors have been reviewed recently [10][11][12][13] and have updated some older reviews. [14][15][16] Clearly, one of these factors is antimalarial drugs.…”

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confidence: 99%

Gametocytemia and infectivity to mosquitoes of patients with uncomplicated Plasmodium falciparum malaria attacks treated with chloroquine or sulfadoxine plus pyrimethamine.

Robert¹,

Awono-Ambene²,

Hesran³

et al. 2000

The American Journal of Tropical Medicine and Hygiene

105

102

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Abstract. Plasmodium falciparum gametocytemia and its related infectivity for mosquitoes was studied in 115 patients (median age ϭ 18 years, range ϭ 4-45) with simple malaria attacks who lived in the hypoendemic area of Dakar, Senegal. Patients were included in a 28-day in vivo sensitivity test after treatment with chloroquine (CQ, n ϭ 82) or sulfadoxine plus pyrimethamine (SP, n ϭ 33). The prevalence of resistant infections was 58.5% in those treated with CQ and 0% in those treated with SP. The gametocytemia peaked at day 7 after treatment. The maximal gametocyte prevalence was 38.2% in the CQ-sensitive infection group, 89.6% in the CQ-resistant group, and 97.0% in those treated with SP. The maximal geometric mean gametocytemia was 2.19/l in the CQ-sensitive infection group, 29.12/l in the CQ-resistant group and 85.55/l in those treated with SP. The period between appearance of the first clinical symptom and treatment was positively related to gametocyte prevalence at days 0 and 2. Experimental infection of wild Anopheles arabiensis using membrane feeders was performed at days 0 and 7, and mosquito infectivity was measured by oocyst detection on the midgut. At day 0, 14.1% of the patients had infected at least 1 mosquito, and at day 7, this value was 38.5%. The mean percentage of infected mosquitoes was 3.2% at day 0 and 12.6% at day 7. At day 7 after treatment with CQ, the relative risk for patients with resistant infections of infecting anophelines was 4.07 higher than in those with sensitive infections. No difference was observed in infectivity for mosquitoes between RI-type resistance and the RII ϩ RIII-type resistance. A sporonticidal effect of SP was observed at day 7 after treatment. These data show that P. falciparum gametocytes and their infectivity for mosquitoes were differentiated according to the drug used, its efficacy, and the duration of symptoms before treatment; they were not dependent on the density of asexual stages. Prompt treatment of malaria cases performed at the beginning of symptoms could limit the spread of resistant parasites.The factors that trigger and regulate the switch from asexual to sexual development of the malaria parasite remain largely mysterious, 1,2 but may involve both genetic mechanisms 3 and environmental mechanisms, 4 especially when conditions deteriorate. Completion of Plasmodium falciparum gametocytogenesis (from merozoite to morphologically mature gametocyte) takes 10-12 days in vivo, 5,6 an estimate that is consistent with the 10 days observed in vitro. 7 In the peripheral blood stream, the mature gametocyte has a halflife of 2.4 days and 1 gametocyte generation may persist for up to 3 weeks. 8 In continuous culture, the progeny of a single schizont is either only asexual parasites or only gametocytes, indicating a commitment to 1 or the other path of development prior to the merozoite stage. 9 The passage of the malaria parasite from humans to the mosquito vector is characterized by one word: variability. This intriguing phenomenon has been observed by many inv...

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“…Moreover, sporozoites need to pass through several biological processes inside the salivary glands in order to reach the salivary duct (Pimenta et al 1994). Although there are few thousands of sporozoites stocked up in the salivary gland, only a small number is ready to be injected by the mosquito bites (Simonetti 1996). Certainly, not all sporozoites obtained from the salivary gland by the isolation procedure are able to stay alive and develop infection in the skin host.…”

Section: Discussionmentioning

confidence: 99%

Effect of the Aedes fluviatilis saliva on the development of Plasmodium gallinaceum infection in Gallus (gallus) domesticus

Rocha

Braga

Araújo

et al. 2004

Mem. Inst. Oswaldo Cruz

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Effect of Aedes fluviatilis saliva on the development of Plasmodium gallinaceum experimental infection inSaliva components from haematophagous arthropods may modulate the host immune system and would represent an adaptation to evolution related with the blood feeding behavior (Ribeiro et al. 1984, Ribeiro 1987, 1989, James & Rossignol 1991. Several substances in saliva from different vectors such as ticks, phlebotomine, and mosquitoes prevent host homeostasis at the bite site during the blood ingestion. Such components may show different activities such as anti-homeostatic, vasodilator, anti-inflammatory, immune-suppressor, and many others (review in Kamhawi et al. 2000).The effect of saliva substances on the pathogen infectivity to vertebrates was firstly demonstrated by Titus and Ribeiro (1988) in phlebotomine followed by Junes and collaborators (1993) in ticks. Nowadays, the importance of saliva for blood feeding and pathogen infections has been extensively analyzed in several arthropod vectors (review in Gillespie et al. 2000). Therefore, there are few studies about the effect of mosquito saliva on infectivity of Plasmodium parasites. Early studies showed some protection against infection by P. berghei sporozoites when mice were previously immunized with mosquito salivary gland homogenate (Alger et al. 1972, Alger & Harant 1976). In addition, Vaughan et al. (1999) suggested that saliva was one of the factors that could contribute to a more efficient rodent infection when the parasites were injected by mosquito vector bites. In the current study, we evaluate the role of Aedes fluviatilis saliva in the experimental infections of chicken Gallus (gallus) domesticus with P. gallinaceum, the causative agent of avian malaria and its immunogenic potential to control parasitemia. MATERIALS AND METHODSMosquitoes -Ae. fluviatilis were obtained from a colony established and kept in the Laboratory of Medical Entomology, Centro de Pesquisas René Rachou-Fiocruz in the state of Minas Gerais. The mosquitoes were kept in an acclimated insectary with average temperature between 26-28 o C and relative air humidity around 70-80%, in a cycle of 12 h in the dark and 12 h in the light (Consoli & Williams 1978). The mosquitoes were provided with 10% glucose solution and water until the time of the experiments.Mosquito infection -Groups of 4 to 6 day-old female mosquitoes were allowed to feed on the skin of P. gallinaceum infected chickens (parasitaemia levels ranging from 3.5 to 10%). The infection evaluation was carried out 7 to 9 days after the infective blood meal by the presence of ookinetes in dissected midguts, which were dissected in PBS (phosphate buffer solution) and stained with 2% mercury chrome in order to visualize the parasites. The percentage of infected mosquitoes and the number of ookinetes per midgut were recorded through optical microscopic examination. All mosquitoes used to infect chickens were also previously examined for the presence of sporozoites 14 days after the infection (Ozaki et al.1984).Chickens -New...

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The biology of malarial parasite in the mosquito: a review

Cited by 27 publications

References 255 publications

Anopheles stephensi salivary glands bear receptors for region I of the circumsporozoite protein of Plasmodium falciparum

Anopheles stephensi salivary glands bear receptors for region I of the circumsporozoite protein of Plasmodium falciparum

Gametocytemia and infectivity to mosquitoes of patients with uncomplicated Plasmodium falciparum malaria attacks treated with chloroquine or sulfadoxine plus pyrimethamine.

Effect of the Aedes fluviatilis saliva on the development of Plasmodium gallinaceum infection in Gallus (gallus) domesticus

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