Mosquito spiroplasmas from France and their ecology.

Spiroplasmas have been isolated previously from a number of blood-sucking arthropods, including ticks, horseflies, and deerflies. More recently, spiroplasmas were isolated from mosquitoes from the USA, France, and Taiwan. Spiroplasmas isolated from mosquitoes from France belong to at least three serogroups and are serologically different from one of the Taiwan isolates, Sp2. Our Ar 1343 strain is the prototype of a new serogroup (XIII). During 3 consecutive years (1983-85), the ecology of these spiroplasmas was studied in different biotopes near, and in, the Isère River Valley in Savoia, France. A total of 23 strains was isolated from four species or groups of mosquitoes (Aedes sticticus/vexans, Ae. cantans/annulipes, Ae. cinereus/geminus and Coquillettidia richiardii). Spiroplasmas were isolated only from female mosquitoes and only during June and July. An as yet unidentified virus was also isolated from three mosquito pools, one of which yielded spiroplasmas. Spiroplasma viruses were not detected. Antibody to our Ar 1357 isolate was found in 4 of 20 sera from cows living in the areas studied, but not in sera from wild rodents or in sera from rabbit or pigeon sentinels. Finally, preliminary results are presented on the effects of experimental infection of Ae. aegypti with the Ar 1357 isolated (serogroup XXII).

[Amphizoic stage of free amoebae, myth or reality (could oxygen be the limiting factor?)]. / L'amphizoïdie des amibes libres, mythe ou réalité (l'oxygène serait-il le facteur limitant?).

We did not succeed to show of true free living amoebic parasites in stools of 207 micromammals from Finistere area, while on the other side 17 stool cultures were positive. To explain this failure, we exposed A. culbertsoni to oxygen: the trophozoit stage offers astonishing resistance during 1 to 6 hours and under 1 to 36 ATA pressures. Thus the lack of intestinal amphizoic free living amoebae could be explained by their very high affinity for oxygen and their lack of growth in a medium without this gas.

[Hydrophilic contact lenses and pathogenic microorganisms]. / Lentilles cornéennes hydrophiles et microorganismes pathogènes.

A first study was conducted on 243 hydrophilic contact lenses: 65 were macroscopically abnormal and 100 were infected with fungi. Moreover on Sabouraud's medium with chloramphenicol, 30 bacterial strains were isolated of which 25 Pseudomonas sp. (10 Ps. cepacia) and 1 Serratia liquefaciens. Then a second study was conducted on 107 among the 243 lens solutions: the 50 of the B trade mark were spoiled with 12 X 10(7) bacteria/ml and the 57 of the C trade mark with 5 X 10(7) bacteria/ml. This quantitative bacterial difference was confirmed with a qualitative one: from B trade-mark 6 Pseudomonas aeruginosa strains were isolated and from C only one. The authors emphasize the importance of Ps. aeruginosa in corneal ulcers associated with contact lenses, of lens solution composition, and of preservative usefulness.

[Arbovirus serological survey among marine and non-marine birds of Brittany]. / Enquête sérologique arbovirus chez des oiseaux marins et non marins de Bretagne.

Sera from 215 seabirds (mainly gulls) and 74 landbirds (mainly starlings) from Brittany were studied by hemagglutination inhibition and complement fixation tests for antibody against 9 arboviruses among them 8 were previously isolated from ticks associated with seabirds. Among seabirds, 145 or 65% were found positive for flaviviruses and nairoviruses of the Hughes serogroup. Unexpected frequency of HI positive reactions for Tyuleniy virus indicate the possible circulation of this virus among seabirds colonies of Brittany in addition to the recently isolated Meaban flavivirus. Among landbirds, only one positive HI reaction for Tyuleniy virus was detected in a house sparrow (Passer domesticus) and it seems that landbirds may not play an important role in the dissemination of these arboviruses to man and to domestic animals.