In vitro antibacterial activity and acute toxicity studies of aqueous-methanol extract of Sida rhombifolia Linn. (Malvaceae)

<p>Abstract</p> <p>Background</p> <p>Many bacteria among the Enterobacteria family are involved in infectious diseases and diarrhoea. Most of these bacteria become resistant to the most commonly used synthetic drugs in Cameroon. Natural substances seem to be an alternative to this problem. Thus the aim of this research was to investigate the <it>in vitro </it>antibacterial activity of the methanol and aqueous-methanol extracts of <it>Sida rhombifolia </it>Linn (Malvaceae) against seven pathogenic bacteria involved in diarrhoea. Acute toxicity of the most active extract was determined and major bioactive components were screened.</p> <p>Methods</p> <p>The agar disc diffusion and the agar dilution method were used for the determination of inhibition diameters and the Minimum Inhibitory Concentration (MICs) respectively. The acute toxicity study was performed according WHO protocol.</p> <p>Results</p> <p>The aqueous-methanol extract (1v:4v) was the most active with diameters of inhibition zones ranging from 8.7 - 23.6 mm, however at 200 μg/dic this activity was relatively weak compared to gentamycin. The MICs of the aqueous-methanol extract (1v:4v) varied from 49.40 to 78.30 μg/ml. <it>Salmonella dysenteriae </it>was the most sensitive (49.40 μg/ml). For the acute toxicity study, no deaths of rats were recorded. However, significant increase of some biochemical parameters such as aspartate amino-transferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and creatinine (CRT) were found. The phytochemical analysis of the aqueous methanol extract indicated the presence of tannins, polyphenols, alkaloids, glycosides, flavonoids and saponins</p> <p>Conclusion</p> <p>The results showed that the aqueous-methanol extract of <it>S. rhombifolia </it>exhibited moderate antibacterial activity. Some toxic effects were found when rats received more than 8 g/kg bw of extract.</p> <p><it>Antibacterial; Enterobacteria; Acute toxicity; Phytochemical analysis</it></p

Genetic pattern of the ST 61 cluster of the Cameroon family among Mycobacterium tuberculosis complex strains collected during the CANTAM I project in Cameroon

Tuberculosis (TB) remains one of the most outstanding diseases in global health concern. It is caused by Mycobacterium tuberculosis Complex (MTBC) strains. ST 61, a cluster of the LAM10_CAM family has been shown to be the most prevalent cluster implicated in TB transmission in Cameroon. The present study is aimed at revealing the most discriminative loci applied to this cluster and investigating the genetic pattern in the ST 61 cluster clinical samples. This was a 12 month cross- sectional study that included 45 randomly selected clinical specimens previously collected during the CANTAM 1 project. Following DNA extraction, amplification of 12-locus Mycobacterial Interspersed Repetitive Unit-Variable Tandem Repeat (MIRU-VNTR) analysis (MIRU 40, ETR A, QUB 26, Mtub 39, QUB 4156, MIRU26, MIRU 31, MIRU 16, MIRU 02, MIRU 04, MIRU 23, and MIRU 27) PCR assay and gel electrophoresis were performed. The amplicon sizes, the allele assignations, the allelic pattern and the technic discriminative potential were determined using MIRU-VNTR plus web application and a dendogram was generated. 45% genetic pattern, and 66,6% clustering rate were reported. Overall, ETR A, MIRU 4, MIRU 16, MIRU 23, MIRU 27 revealed as the most discriminating loci applied to the cluster ST 61. The identification of the most discriminative locus ETRA, MIRU 4, MIRU 16, MIRU 23, and MIRU 27 applied to a precise cluster is a safe economic and time gain option to enhance the difference between strains at the cluster level.</jats:p