Antifungal potential of extracts from four plants against Acremonium apii and Colletotrichum dematium, two major pathogens of celery (Apium graveolens L.) in Cameroon

In order to contribute to a sustainable control of plant diseases through the use of natural compounds, the antifungal potential of 11 extracts from 4 Cameroonian plants (Ageratum conyzoides, Callistemon citrinus, Cymbopogon citratus and Ocimum gratissimum) was evaluated in vitro against Acremonium apii and Colletotrichum dematium, respectively the causal agents of brown spots and anthracnose diseases of celery (Apium graveolens L.). Inhibition of fungi mycelial growth by essential oils, ethanol and aqueous extracts was assessed by using the supplemented media technique. Essential oils exhibited comparable activities against both fungi with minimum inhibitory concentration between 400 and 6000 ppm. Essential oil from O. gratissimum showed the highest inhibitory activity against both pathogens (400 ppm) followed by C. citratus (700 ppm and 800 ppm against A. apii and C. dematium, respectively), and then C. citrinus (6000 ppm). Ethanol extracts exhibited after the essential oils, the higher inhibitory activity against the two pathogens. Extract of C. citrinus was the most active with reductions of radial growth of 77.68% and 97.16% respectively against A. apii and C. dematium at 10000 ppm. Aqueous extracts at the same concentrations of ethanol extracts had little or no activity against both fungi. The fungitoxic potential of essential oils was higher than the one of the synthetic fungicide used as positive control. Our results suggest a promising potential of essential oils and ethanol extracts for botanicals control of celery fungal pathogens

Predictors of childhood severe malaria in a densely populated area: Douala, Cameroon

The physiopathology of malaria is complex. More understanding would be useful for a better management of the disease. This study was undertaken to describe clinical presentation and some biochemical parameters in childhood malaria in order to identify some factors of disease severity. Eighty six (86) children (0 to 15 years old) were recruited in Douala, clinical data recorded and blood sample collected. Thirty one (31) healthy children were also targeted to serve as control. Blood glucose, hemoglobin, transaminases and nitric oxide were determined by spectrophotometry. C reactive protein (CRP) was also investigated. The results confirmed that severe malaria significantly affects children under 5 years. Severe malaria was associated with hyperpyrexia and prostration. Coma, convulsions and unconsciousness were more indicative of cerebral malaria. Hemoglobin and blood glucose levels decreased significantly in severe malaria patients compared with uncomplicated malaria patients or controls (P < 0.001). On the contrary, blood transaminases and CRP levels increased significantly in malaria patients compared to controls (P < 0.001). From these results, it is clear that childhood severe malaria is associated with prostration, coma, unconsciousness, convulsions and hyperpyrexia. Low levels of haemoglobin and glycemia, as well as high levels of transaminases and CRP has been identified as predictor of malaria severity

Composition of four essential oils obtained from plants from Cameroon, and their bactericidal and bacteriostatic activity against Listeria monocytogenes, Salmonella enteritidis and Staphylococcus aureus

The composition of four essential oils (EOs) extracted by hydrodistillation from plants of common use in Cameroon (Curcuma longa, Xylopia aethiopica, Zanthoxylum leprieurii L., Zanthoxylum xanthoxyloides) was assessed by gas chromatography-mass. Their bactericidal and bacteriostatic activity was tested in vitro against three food borne pathogenic bacteria: Listeria monocytogenes, Salmonella enteritidis and Staphylococcus aureus. The bacteriostatic activities of this EOs on food borne bacteria were assessed in vitro through optical density measurements. The minimal bactericidal concentrations (MBC) were determined in broth combined with a spot plating method. Z. xanthoxyloides and Z. leprieurii showed a similar composition, with a prevalence of oxygenated monoterpenes (about 58%). The EO of Z. xanthoxyloides was the most effective against the microorganisms tested. Its higher concentration of geraniol could be linked to this higher activity. In almost all cases, the MBC was higher than the maximum concentration tested (3000 ppm). Notwithstanding their low bactericidal effect, the EOs studied showed interesting inhibiting activities against the tested food borne pathogens. S. enteritidis was the most resistant to the bacteriostatic effect of the four EOs. The knowledge of the antimicrobial potential of local plant EOs used in developing countries could help in their choice and their use to improve food safety and shelf-life