Gastro-entérites en milieux des réfugiés au Tchad

Les réfugiés et déplacés de guerre sont des personnes vulnérables. C’est pourquoi, nous avons entrepris une étude des gastro-entérites dans leurs milieux au Sud et à l’Est du Tchad. Cette étude a concerné 53 patients dans les camps du Sud dont 28,30% sont des enfants de 0 à 5 ans. Elle a été couplée d’une enquête sur l’état nutritionnel de 205 réfugiés dans les deux zones. L’isolement et l’identification des entéropathogènes dans les selles ont été réalisés au laboratoire de l’Hôpital Général de Référence Nationale (HGRN), en utilisant les milieux Hektoen, Mueller-Hinton, EMB, Saboraud Chloramphénicol et la galerie API® 20 E. La microscopie, les tests de filamentation et biochimiques ont permis de caractériser et de déterminer les taux des infestations parasitaires, fongiques et d’infections bactériennes qui sont respectivement de 18,86%, 11,32% et 24,52%. La caractérisation de la sensibilité des agents bactériens Salmonella, Shigella et Escherichia coli a montré une résistance de 85% aux bêta-lactamines. En revanche, 98% des germes sont sensibles aux fluoroquinolones. Cette étude nous a permis non seulement de connaître les caractéristiques des diarrhées liées à l’état nutritionnel des réfugiés, mais également, de mettre en évidence une antibiothérapie efficace permettant la mise en place d’un programme de prévention contre les maladies diarrhéiques et d’amélioration de leur état nutritionnel dans les milieux confinés. L’amélioration de l’état nutritionnel des enfants pourrait comporter : la distribution régulière et complète des aliments riches en vitamines ; l’extension des programmes d’alimentation d’appoint et le logement adéquat pour les réfugiés.Mots clés: Diarrhée, entéropathogènes, nutritionnel, antibiotique, HGRN

Profil de résistance des agents étiologiques des diarrhées isolés au Tchad

La résistance aux antibiotiques des entéropathogènes impliqués dans les maladies diarrhéiques est une préoccupation d’ampleur mondiale. C’est pourquoi la présente étude était entreprise en vue de tester la sensibilité de ces microorganismes aux antibiotiques couramment utilisés au Tchad. Les selles des patients ont été prélevées dans des flacons stériles et analysées selon les procédures standards de microbiologie dans le laboratoire de Bactériologie de l’Hôpital Général de Référence Nationale de N’Djamena (HGRN). L’isolement et l’identification des entéropathogènes dans les selles étaient réalisés, en utilisant les milieux Hektoen, EMB (éosine bleu de méthylène), TCBS (thiosulfate, citrate, bile, saccharose) (BioRad) et la galerie API® 20E et API® 20 NE (BioMérieux). L’antibiogramme a été effectué selon la méthode de Kirby Bauer en utilisant le milieu Mueller-Hinton. Le test antigénique était réalisé conformément aux instructions de Kaufmann-White. Au total, les selles de 1164 patients ont été analysées, desquelles 275 entéropathogènes étaient isolés, identifiés et testés aux antibiotiques. Parmi les souches d’entérobactéries étudiées, les Escherichia coli étaient résistants de 70% aux Bêta-lactamines. Les Vibrio cholerae O 1 en particulier ont exprimé un taux de résistance de 15,30% à l’ampicilline, 100% à l’amoxicilline + acide clavulanique et triméthoprime/cotrimoxazole, 98,90% à l’acide nalidixique et 12,56% à la ceftriaxone. Ces résultats attestent de la circulation des entéropathogènes résistants aux antibiotiques usuels au Tchad.Mots clés : Diarrhée, entéropathogène, antibiotique, résistance, HGRN, Tchad

Derivation and characterisation of a quinapyramine-resistant clone of Trypanosoma congolense

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN204508 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Cross-resistance phenotypes associated with induction of resistance to isometamidium chloride and quinapyramine sulphate in Trypanosoma congolense

Isometamidium chloride (Samorin Trypamidium), diminazene aceturate (Berenil, Veriben), homidium chloride (Novidium), homidium bromide (Ethidium) and the salts of quinapyramine (Trypacide, Triquin) are all anti-trypanosomal compounds that are routinely used in domestic livestock. However, the salts of quinapyramine are restricted to use in horses and camels. All four compounds have been used in the field for at least 35 years and the incidence of resistance to each compound appears to be increasing. Furthermore, in some instances, multiple-drug resistance has been Reported and is a particular threat to livestock production. Because isometamidium, homidium, diminazene and quinapyramine are chemically closely related, cross-resistance has been suggested to occur between a number of these compounds and may therefore contribute to the multiple-drug resistance phenotypes observed in the field. However a clear definition of the cross-resistance relationships has not been possible due to the lack of trypanosome populations in which resistance to individual trypanocides has been unequivocally induced. Trypanosoma congolense IL 1180 is a cloned population that expressed a high level of sensitivity to isometamidium chloride, quinapyramine sulphate, homidium chloride and diminazene aceturate; the dose required to cure 50 percent of infected mice (CD 50 value) are 0.018 mg/kg body weight (b.w.), 0.23 mg/kg b.w., 0.37 mg/kg b.w. and 2.3 mg/kg b.w., respectively. In the work described here repeated subcurative treatment of infected Swiss white mice with either isometamidium chloride (Samorin) or quinapyramine sulphate (Trypacide) was used to independently increase the resistance of T. congolense IL 1180 to these two compounds. In the first experiment the resistance of T. congolense IL 1180 to isometamidium was increased to a CD 50 of 1.7 mg/kg b.w. over an 11-month period of drug selection to produce a population designated t. congolense IL 3343. Trypanosoma congolense IL 3341 and T. congolense IL 3342 were intermediate populations produced after 5 and 7 months drug selection, respectively. In order to determine whether Development of resistance to isometamidium resulted in cross-resistance to other anti-trypanosomal compounds, T. congolense IL 3343 was characterised in mice for its sensitivity to diminazene aceturate, homidium chloride and quinapyramine sulphate and had CD 50 values of 7.8 mg/kg b.w., 12.1 mg/kg b.w., respectively. Thus, a 94-fold increase in resistance to isometamidium chloride was associated with a 3-fold increase in resistance to diminazene, a 33-fold increase in resistance to homidium, and a 4-fold increase in resistance to quinapyramine. Values for T. congolense IL 3341 and T. congolense IL 3342 were intermediate between those of T. congolense IL 1180 and T. congolense IL 3343. In a second study, resistance to quinapyramine sulphate was induced in T. congolense IL 1180 over a 7-month period of drug selection, resulting in a population designated T. congolense IL 1180/Stabilate 12. This population had a quinapyramine sulphate CD 50 of > 9.6 mg/kg b.w., and diminazene aceturate, homidium chloride and isometamidium chloride CD 50 values of 12.7 mg/kg b.w., 10.g mg/kg b.w. and 0.10 mg/kg b.w., respectively (Table 2). Thus, an approximately 40-fold increase in resistance to quinapyramine was associated with a 6-fold increase in resistance to isometamidium, 1 28-fold increase in resistance to homidium and a 6-fold increase in resistance to diminazene. In summary, these data indicate that Development of resistance to isometamidium in T. congolense IL 1180 was associated with a high level of cross-resistance to homidium, but low levels of cross-resistance to diminazene and quinapyramine. In contrast, the present data and those from goats indicate that Development of resistance to quinapyramine in the same trypanosome clone was associated with relatively high levels of cross-resistance to isometamidium, homidium and diminazene. These data therefore confirm the rationale for using isometamidium and diminazene as a "sanative" combination, and indicate that the use of quinapyramine in cattle, sheep and goats is contra-indicated since Development of resistance to the compound results in relatively high levels of cross-resistance to all three anti-trypanosomal compounds recommended for use in these livestock species. Finally, since resistance to diminazene is difficult to induce experimentally with diminazene, and such resistance usually occurs in the field as part of a multiple-resistance phenotype (Peregrine, 1994)

Determination des valeurs usuelles des parametres sanguins chez le tchadien du sexe masculin

No Abstract. Journal de la Recherche Scientifique de l\'Universite du Benin Vol. 4 (2) 2000: pp. 265-26

Sensitivity of Kirdimi and Sahelian goats of Chad to <em>Trypanosoma congolense</em> infection

Sahelian and Kirdimi goats of Chad were studied in an experimental farm for trypanotolerance. Fifty-five (55) animals, 28 Sahelians and 27 Kirdimis, whose hemoglobin types had been determined, were experimentally infected, each one with 10^6 trypanosomes (Trypanosoma congolense IL1180 stock, savanna type). The animals were regularly monitored for six months for clinical symptoms, bodyweight, hematological and biochemical parameters. The infection induced sudden significant weight loss in Sahelian goats. On the other hand, no significant weight variations were observed in Kirdimis. The average prepatent period was 7 and 12 days for Sahelian and Kirdimi goats, respectively. Parasitemia appeared to develop quickly in Sahelian goats (within a month). It was well under control in Kirdimis throughout the experimental period, and some self-cure cases were even observed. Sahelian goats, apparently more susceptible to the infection, displayed during the acute phase of the disease lack of appetite, pale ocular membranes, watering eyes, staggering movements and occasional diarrheas. The packed cell volume was stable in Kirdimis. It dropped rapidly in Sahelian goats and often reached the critical point of 15%. At that threshold the animals were unable to stand up and died unless a trypanocide treatment was applied. The T. congolense trypanosomosis evolution was mainly associated in Sahelian goats and at different levels with important changes in hematological and biochemical parameters. This study shows that Kirdimi goats control T. congolense infections better than Sahelian goats