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Abstract:A study was carried out in two villages and one marketplace of the Batibo subdivision in North-West Cameroon to determine the prevalence of porcine cysticercosis. The results showed that 4.44% of 383 pigs were positive at tongue examination whereas ELISA detected circulating antigens in 27.7% of 271 pig sera. A questionnaire survey in 140 pig raising households indicated that 59.3% of them lacked latrines while in 75.7% of the households members defecated directly into pigpens. The seroprevalence of porcine cysticercosis was significantly higher in households without latrines than in those with latrines. Similarly, significantly more seropositive pigs were present in households that defecated in the pig pens (35.5%) than in those that did not (14.4%). Although 91.4% of pig raising households did know of pig cysticercosis, only 28.6% were aware of the link with human taeniasis and only 10.7% were aware of human cysticercosis.

Abstract:The frequency of Taenia solium cysticercosis was studied in a series of 504 epileptic patients from 3 rural localities in the West and North-west provinces of Cameroon using ELISA both for circulating antigen (Ag-Elisa) and antibody detection (Ab-Elisa). T. solium antigens were detected in the sera of 1.2% of the epileptics whereas specific antibodies against the parasite were present in 44.6% of patients. Significantly more seropositives in Ab-Elisa were recorded in Batibo than in Bandjoun and Batibo whereas a borderline significant difference was recorded with increasing age. Furthermore, 50% of patients with late-onset epilepsy showed antibodies against cysticercosis. T. solium cysticercosis appears to be an important cause of epilepsy in Cameroon.

A partir d’août 2002 jusqu’à juillet 2003, une enquête sérologique a été conduite à l’abattoir de Dschang (Ouest Cameroun) afin de déterminer la prévalence de la brucellose bovine. Huit cent quarante sérums bovins ont été examinés par l’Elisa indirect (iElisa) et le test au rose bengale (TRB). La séroprévalence de la brucellose a été de 9,64 et 4,88 p. 100 en utilisant respectivement l’iElisa et le TRB. Quatre-vingt et un sérums positifs avec iElisa et 50 sérums sélectionnés aléatoirement parmi les sérums qui ont été négatifs en iElisa et TRB ont été examinés par le test de fixation du complément (TFC) et le test d’agglutination lente de Wright avec Edta (SAW-Edta). Tous les échantillons négatifs en TRB/iElisa ont été confirmés comme étant négatifs par les autres tests, suggérant que le TRB et l’iElisa montraient une haute spécificité dans la population testée. Parmi les sérums iElisa positifs, 37,8 p. 100 ont été classés positifs par SAW-Edta, TRB et TFC, 39,2 p. 100 ont été classés négatifs par SAW-Edta, TRB et TFC, et 23,0 p. 100 ont été classés positifs dans un ou deux des trois tests de confirmation. Etant donné le manque de sensibilité des tests de confirmation, en particulier lors d’infections chroniques dans des systèmes d’élevage extensifs (pastoralisme), la meilleure estimation de la prévalence réelle de la brucellose a été basée sur les résultats en iElisa et a été de l’ordre de 10 p. 100.

Copper is required for aerobic respiration by Mycobacterium tuberculosis and its human host, but this essential element is toxic in abundance. Copper nutritional immunity refers to host processes that modulate levels of free copper to alternately starve and intoxicate invading microbes. Bacteria engulfed by macrophages are initially contained within copper-limited phagosomes, which fuse with ATP7A vesicles that pump in toxic levels of copper. In this report, we examine how CtpB, a P-type ATPase in M. tuberculosis, aids in response to nutritional immunity. In vitro, the induced expression of ctpB in copper-replete medium inhibited mycobacterial growth, while deletion of the gene impaired growth only in copper-starved medium and within copper-limited host cells, suggesting a role for CtpB in copper acquisition or export to the copper-dependent respiration supercomplex. Unexpectedly, the absence of ctpB resulted in hypervirulence in the DBA/2 mouse infection model. As ctpB null strains exhibit diminished growth only in copper-starved conditions, reduced copper transport may have enabled the mutant to acquire a “Goldilocks” amount of the metal during transit through copper-intoxicating environments within this model system. This work reveals CtpB as a component of the M. tuberculosis toolkit to counter host nutritional immunity and underscores the importance of elucidating copper-uptake mechanisms in pathogenic mycobacteria.

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