Folia Parasitologica 49[1] 73-77 (2002) | DOI: 10.14411/fp.2002.014

Bacterial colonisation in the gut of Phlebotomus duboscqi (Diptera: Psychodidae): transtadial passage and the role of female diet

Petr Volf¹, Alena Kiewegová¹, Alexandr Nemec²

¹ Department of Parasitology, Charles University, Viničná 7, 128 44 Prague 2, Czech Republic

² National Institute of Public Health, Šrobárova 48, 100 42 Prague 10, Czech Republic

Bacteria isolated from the gut of different developmental stages of Phlebotomus duboscqi Neveu-Lemaire, 1906 belonged almost all to aerobic or facultatively anaerobic gram-negative rods. In females, the highest bacterial counts were observed two days after bloodfeeding; seven days after bloodfeeding the bacterial counts returned to pre-feeding levels. Most isolates were identified phenotypically as Ochrobactrum sp. The distinctiveness and homogeneity of the phenotypic and genotypic characteristics of Ochrobactrum isolates indicated that they belonged to a single strain (designated AK). This strain was acquired by larvae from food and passaged transtadially: it was isolated from the guts of fourth-instar larvae shortly before pupation, from pupae as well from newly emerged females. Most other bacteria found in females were acquired from the sugar solution fed to adults. To determine if the midgut lectin activity may serve as antibacterial agent females were membrane-fed on blood with addition of inhibitory carbohydrates. No significant differences in bacterial infections were found between experimental and control groups and we suppose that the lectin activity has no effect on gram-negative bacteria present in sandfly gut.

Keywords: sandfly, bacteria, Ochrobactrum, Leishmania, lectin, transtadial transmission

Received: January 16, 2001; Accepted: June 13, 2001; Published: March 1, 2002  Show citation