RESUMEN
A polymerase chain reaction (PCR)-based diagnostic assay was developed that rapidly and reliably differentiates the sibling species of the Anopheles claviger complex, An. claviger s.s. and An. petragnani. The assay makes use of nucleotide differences in the internal transcribed spacer 2 ribosomal DNA sequences to generate PCR products of specific length for each of the two species. In evaluating the test, 580 of 592 field-collected An. claviger s.l. specimens were unambiguously identified as one of the two sibling species. Due to poor DNA quality, the remaining 12 specimens yielded no PCR product. Of the 592 mosquitoes, 407 larval specimens had been identified morphologically prior to species-specific DNA amplification, and in all instances PCR identification corroborated with morphologic identification. Mosquitoes identified as An. claviger s.s. came from various localities all over Europe and from Israel. Those identified as An. petragnani were collected in southern France and Spain. The species-diagnostic PCR assay would facilitate data collection on the temporal and spatial distribution of the two An. claviger sibling species because they represent possible vectors of disease in Europe, the Near and Middle East, and north Africa.
Asunto(s)
Anopheles/clasificación , Anopheles/genética , Insectos Vectores/clasificación , Insectos Vectores/genética , Malaria/transmisión , Reacción en Cadena de la Polimerasa/normas , Animales , Secuencia de Bases , Cartilla de ADN , ADN Ribosómico/genética , Europa (Continente) , Larva/genética , Datos de Secuencia Molecular , Alineación de SecuenciaRESUMEN
Prompted by four autochthonous cases of malaria in 1994 and 1995 in Evros Province, northern Greece, we conducted an entomological study between 1997 and 1999 in Nipsa and Chandras, rural locations where two of the four cases had occurred, and in Feres where two additional autochthonous malaria cases had been diagnosed in 1998. In Nipsa and Chandras, we identified 29 Anopheles breeding sites and characterized them by physicochemical parameters. Larvae were collected both at these sites and in a brackish water breeding site near Feres in the Evros River delta. Adults were caught in sheds at all three locations. Morphology was used to classify larvae and adults as A. superpictusor as species belonging to the A. claviger or A. maculipennis species complexes. The latter were further identified by PCR as being A. maculipennis s.s., A. melanoon and A. sacharovi. Of the A. maculipennis complex larvae collected inland, approximately 94% were A. maculipennis s.s. and 6% A. melanoon, whereas all larvae collected in the coastal region were A. sacharovi. In contrast, the A. maculipennis adults were A. maculipennis s.s. and A. melanoon (both 47%), and A. sacharovi (6%). In the coastal region, no A. maculipennis s.s. adults were caught. The ratio of A. melanoon adults collected to A. sacharovi was about 3:1. As shown by a bloodmeal ELISA, only 5 of 266 fed females (1.9%) had ingested human blood, whereas 232 (87%) had fed on goats. Of the mosquitoes containing human blood, two were A. melanoon, one A. sacharovi and one A. maculipennis s.s. One human blood specimen could no longer be assigned to a particular mosquito.