Drug resistance pattern of Salmonella and Shigella species isolated from selected hospitals in Anyigba, Kogi State, Nigeria

This work was designed to assess the status of Salmonella and Shigella infections in Anyigba, Kogi State, Nigeria with a view to making informed statements that may guide policy makers and public health experts in the containment efforts against these infections. Salmonella and Shigella species isolated from human faecal samples were examined for resistance to some antibiotic agents using disc diffusion methods. Drug resistant isolates were analyzed for presence of plasmids by basic curing and transferability methods. Age distribution of sources of resistant isolates showed that Shigella isolates from Youths (18 - 30 years) were more resistant to Ampicilin (66.67%) and Augmentin (33.33%) than isolates from Infants (6 months - 4 years) (3% Ampicillin and 0% Augmentin). Salmonella species isolated from Adults (31 – above) were more resistant to Augmentin (45%) and Ampicillin (40%), than isolates from Youths (18- 31 years) (40% Ampicillin and 36.67% Augmentin). Salmonella isolated from Infants (6 months – 4 years) showed percentage resistance of 28.57% to Ampicillin and 14.29% to Augmentin while isolates from Children (5 - 17 years) showed percentage resistance of 25% to Ampicillin and 12.5% to Augmentin. Salmonella species showed higher percentage resistance to commonly used drugs than Shigella species. The result shows that 8% of Shigella species and 21.5% of Salmonella species were resistant to more than eight antibiotics with (MAR) index of between 0.2-0.9. Results of curing and agarose gel electrophoresis (AGE) presumptively showed that the resistance traits were plasmid borne. AGE showed plasmids of molecular weights 23.1 kb for both species of Salmonella and Shigella suggesting their possible exchange among them. This was substantiated by conjugative transfer of resistance determinants among few isolates. The results show convincing evidence of the presence of multidrug resistant Salmonella and Shigella spp. within the study population.