[First cases of keratitis caused by free-living amoebas of the genus Acanthamoeba diagnosed in Mali]. / Premiers cas de kératites a amibes libres du genre Acanthamoeba diagnostiqués au Mali.

The authors present the first three cases of keratitis with Acanthamoeba sp. which have been diagnosed in healthy persons. Two of them are children and in two cases there had been a local traumatism.

[Amoebic keratitis caused by Acanthamoeba sp. May HSV1 infection play a role?]. / Kératite amibienne à Acanthamoeba sp. L'infection par HSV1 aurait-elle un rôle?

Many cases of human keratitis with Acanthamoeba sp. have a pseudo-herpetic appearance. The authors therefore evaluated the importance of co-infection with this virus in the onset of amoebic cornean lesions. After herpetic and amoebic co-infection rabbits showed severe cornean lesions, the viral aspect of cornea received a specific treatment. The amoebic co-infection progressed unchecked with severe lesions until day 37 p.i., in which trophozoites and cysts were numerous. The possible favourising role of HSV1 and Acanthamoeba sp. co-infection may exist in humans, just as it certainly exists in the rabbit.

[Acanthamoeba keratitis in subjects with contact lenses]. / Kératite amibienne à Acanthamoeba chez le porteur de lentilles cornéennes.

A new case of Acanthamoeba keratitis in a young woman using contact lenses is reported. Although the patient strictly complied with decontamination rules, she developed a huge corneal abscess invading the anterior chamber. After a misleading initial phase, the diagnosis was suspected on clinical grounds and was confirmed by parasitologists. The infection followed a favourable course, thereby avoiding surgery and its unpredictable consequences, but an opaque speck remained in the centre of the cornea. This case illustrates a pathology which is getting less and less exceptional, even in France where such pathogens can be found in the water for normal household use. Subjects wearing contact lenses and who are particularly exposed should be warned of the risk of infection they incur. Doctors should be taught to bear this diagnosis in mind in order to guide parasitological investigations and to obtain confirmation as early as possible.

[Acanthamoeba keratitis. Epidemiologic and parasitologic study]. / Kératite amibienne á Acanthamoeba. Etude épidémiologique et parasitologique.

The amebic keratitis with Acanthamoeba are until now rare, but however increasing as their diagnosis is better, and the contact lens wearers more numerous. The authors present the clinical and parasitological features of cases they did diagnose since 1986. In the immunological sphere, the T4 lymphocytes were 20% less than the normal for the first patient, and the third one had a very low level of immunoglobulins A. In the evolution sphere, the first one did received a keratoplasty; the second one has been successfully treated with propamidine isethionate; for the third one, the treatment with propamidine isethionate was nonuseful and a keratoplasty which was finally performed did show off numerous amebic cysts. In the parasitologic sphere, Acanthamoeba polyphaga was isolated from the first case, Acanthamoeba quina from the second one and Acanthamoeba lugdunensis from the last one. These last two cases are the first which did permit to isolate these amoebae, morphologically near to the first species.

[In vitro study of propamidine isethionate: value in the follow-up of Acanthamoeba amebic keratitis]. / Etude in vitro de l'iséthionate de propamidine: intérêt dans le suivi des kératites amibiennes à Acanthamoeba.

Propamidine isethionate eye drops is one of the treatments which are used against amebic keratitis with Acanthamoeba. Several strains of Acanthamoeba, having been tested with this drug during several weeks, did show off a resistance. The authors come to the conclusion that in vitro sensitivity must be examined and therapy must be perfect since the beginning.

[The experimental pathogenic effect of Spiroplasma isolated from mosquitoes on the hatching of Aedes aegypti ova and the growth of larva hatched from these eggs]. / Etude de l'effet pathogène expérimental des spiroplasmes isolés à partir de moustiques sur l'éclosion d'oeufs d'Aedes aegypti et le devenir des larves issues de ces oeufs.

The authors did study the experimental effects on Aedes aegypti ova of different Spiroplasma strains, isolated from mosquitoes in French Savoy and in Taiwan. The SP7 strain, from Armigeres subalbatus (Taiwan), demonstrates a true pathogenic effect on the larval evolution, without sex ratio modifications, nor bacterial transmission to the adult mosquitoes. The authors present their results and emphasize the difficult use of Spiroplasmas sp.

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).

Sanitary study of surface water and of the beach of a water sports and leisure complex.

This report presents the parasitological, bacteriological, mycological and physicochemical data obtained from both surface water and beach sand of a lake used for water sports. These show that the lake is contaminated in both winter and spring by water which overflows from the River Maine, and is self-purified by a mechanism of 'lagunage'. In summer signs of pollution are at their lowest level although use of the complex is at its peak. Conversely, the amoebic flora, which is independent of the usual criteria of pollution, predominates in summer, and serves as a marker for the need for increased surveillance. The sand of the beaches does not appear to show any infectious hazard. Environmental pressure will doubtless change these data over a period of time, and it is planned to monitor this.

[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.

[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.

[Effects of hydrostatic pressure per se and of inert gases on a Limax-type free-living amoeba: Acanthamoeba culbertsoni]. / Effets de la pression hydrostatique per se et des gaz inertes sur une amibe libre du type Limax: Acanthamoeba culbertsoni.

The authors investigated the high hydrostatic and gas (nitrogen and helium) pressure effects on the morphology, missing encysting process and mortality rate of Acanthamoeba culbertsoni trophozoïtes. These studies have been performed by the means of scanning electron microscopy (SEM). It has been possible to show that the modulus of dissolving of both gas in water and oil is insufficient to explain the very important volumetric changes. Thereafter it appears that there is clathrate compounds formation.

[Little savage mammalians: free-living amoebae vectors? (author's transl)]. / Les petits mammifères sauvages: vecteurs d'amibes libres?

We tried to prove the part of the little savage mammalians as active intermediate hosts to the intestine level for some free-living limax amoebae of limax group. For this we participated to several trapping-season in Britanny and in Tunisia. From 273 samplings, we studied 224 with the results thereafter: the rodents are the first (213/224) and the 3 most frequent species are also the most often hosts: 20/128 A. sylvaticus, 9/58 C. glareolus and 4/16 M. spretus. There must be a double positive factor: life in burrow near the earth and meal type. The 78 samplings for which we checked the free-living amoebae by stool examination, are the most poor by culture: 2/78 (2.5 p. 100). This lack explains the negative stool examination. The isolated amoebae belong for 31/34 to the genus Acanthamoeba, of one potentially pathogenic: A. hatchetti. Moreover the Finistere biotop appears particularly poor (2.5 p. 100 carriers in front of 21 p. 100 in Ille-et-Vilaine and 24 p. 100 in Tunisia).

[Free-living Amoebae in fresh water. Study of the water supply of the town of Poitiers (France) (author's transl)]. / Recherche des amibes libres dans l'eau. Etude du réseau d'alimentation en eaux de la ville de Poitiers.

46 out of 76 samples of water originating from the water supply of the town of Poitiers, and concerning each stage of it, were found positive to free-living amoebae. 3/4 of the isolated strains belonged to the genus Acanthamoeba only 2 to the genus Naegleria, and the remaining to the genus Hartmanella. All the strains are insensible to 5-Fluoro-cytosin and Amphotericin B at concentrations compatible with human use. No experimental pathogen power could be demonstrated by inoculation to laboratory mice.

[Taxonomy-trial of the free-living amoebae belonging to the genus Acanthamoeba (Protozoa, Amoeba) by means of the cyst-features in scanning electron microscopy (author's transl)]. / Essai de taxonomie des amibes libres du genre Acanthamoeba (Protozoa, Amoebida) par l'analyse des caractères kystiques en microscopie électronique à balayage.

In order to verify the contribution of scanning electron microscopy to the taxonomic study of free-living amoebae, the authors studied at the encysted stage 21 strains of free-living amoebae representing 20 species (1 Naegleria gruberi, 1 Tetramitus rostratus and 18 Acanthamoeba sp). The method utilized is satisfactory for distinguishing the different genera. Using optical methods, it is possible to differentiate three groups (I, II, III) of Acanthamoeba, including 3, 10 and 5 species, respectively. The results obtained with scanning electron microscopy, however, are less precise. In particular, group II can be divided into only four sub-groups and group III into only two sub-groups and one species, A. culbertsoni. The method remains valid for group I.