This study aimed to evaluate in microcosm condition, the survival of Aeromonas hydrophila and Enteropathogenic Escherichia coli (EPEC), in the presence of M. oleifera aqueous seeds extract at concentrations varying from 1 to 40 g/L, and under 4 °C and 23 °C incubation temperature. It has been noted that cell abundances decrease gradually with the increasing in the seeds extract concentration. However, a marked cells regrowth was sometimes noted. In monospecies cell incubation condition, under 4 °C, the EPEC cells inhibition percentages (CIP) values varied from 52.12 to 99.84%. Those of A. hydrophila varied from 13.2 to 96%. The lowest CIPs were noted at the extract concentration 1g/L for EPEC and A. hydrophila. The highest CIP value was registered at 10 and 40 g/L for EPEC and at 15 g/L for A. hydrophila. Under 23 °C incubation, the EPEC CIPs values varied from 74.04 to 99.9% and those of A. hydrophila varied from 21.2 to 97.8%. For E. coli, the lowest and the highest CIP were recorded at the extract concentration 1g/L and 30 g/L, respectively. In bispecies cells incubation condition, the CIPs were relatively different. These results show the potential exploitation of M. oleifera extracts in the microbiological treatment of potable water.
A bacteriological and physicochemical study was conducted in the waters of farms in mountainous regions of Cameroon. The different water samples were collected during two campaigns in December 2018 and February 2019. Ten stations representing the drinking water supply points in our study area were identified. The results showed that these waters contained both pathogenic and commensal fecal bacteria. The highest abundances reached 10x103 CFU/100mL for Salmonella sp., 72x103 CFU/100mL for Staphylococcus aureus, 102x103 CFU/100mL for Brucella suis and 40x103 CFU/100mL for Brucella abortus. These abundances were subject to space-time fluctuations. Water contamination by tweezers was not general and was present only in surface waters (rivers and ponds). The water in the ponds, rivers and wells analyzed were all basic, with low mineralization on average. The dissolved oxygen ranged from 37.5 to 70.6%, nitrate from 3.7 to 19.8 mg/L and iron from 0.01 to 3.5 mg/L. Most of the physicochemical parameters were relatively stable during the two campaigns. The degree of correlation between the physicochemical parameters and the abundance dynamics of the isolated bacteria was heterogeneous. This was clearly more pronounced with Salmonella sp. and Brucella suis. This would be due to the fraction of metabolically active cells present when the bacteria are exposed to unfavorable conditions. Correlations with the abiotic factors were less marked with Staphylococcus aureus and Brucella abortus; this would be due to their tolerance to environmental stresses.
This study assessed the antibiotics susceptibility of Bacillus cereus, B. thuringiensis and B. subtilis strains isolated in wells and rainwater samples in Yaounde (Cameroon). Water samples in wells were collected monthly during a long dry season (LDS), a short dry season (SDS), a long rainy season (LRS) and a short rainy season (SRS), and during the LRS and the SRS for rainwater. The antibiotics considered included Imipenem, Amikacin, Gentamycin, Ciprofloxacin, Ofloxacin, Sulfamethazol, and Tetracycline. With strains from the groundwater, the antibiotic inhibition diameters varied from 9.13 mm (Sulfametazole during SDS) to 32.78 mm (Imipenem during LDS) with B. thuringiensis, from 8.2 mm (Sulfametazole during SDS) to 35.25 mm (Imipenem during LDS) with B. cereus, and from 5.05 mm (Ofloxacin during LRS) to 29.25 mm (Imipenem during LDS) with B. subtilis. With those from the rainwater, they varied from 4.55 mm (Sulfametazole during LRS) to 25.65mm (Imipenem during LRS) with B. thuringiensis, from 2.13 mm (Imipenem during LRS) to 20.05mm (Imipenem during SRS) with B. cereus, and from 5.03 mm (Gentamicin during SRS) to 25.15mm (Tetracycline during SRS) with B. subtilis. Bacillus strains isolated during LRS were multiresistant to the majority of antibiotics. The inhibition diameters of the most antibiotics varied significantly from one season to another (p<0.05).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.