Abstract:
Salmonella and Shigella species isolated from human faecal samples were examined for Beta-lactamase production and resistance to some antibiotic agents. Age distribution of sources of resistant isolates showed that Shigella isolates from Youths (18 - 30 years) were more resistant to Ampicillin (66.67%) and Augmentin (33.33%) than isolates from Infants (6 months - 4 years) which showed percentage resistance of 3% to Ampicillin and 0% to Augmentin. Salmonella species isolated from Adults (31 – above) were more resistant to Augmentin (45%) and Ampicillin (40%), than isolates from Youths (18- 31 years) which showed percentage resistance of 40% to Ampicillin and 36.67% to 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. Sex distribution of sources of resistant isolates showed that Shigella species isolated from males were more resistant to Ampicillin (100%) while isolates from Females were more resistant to Augmentin (50%). Salmonella species isolated from Males showed high percentage resistance to Augmentin (60%) while isolates from Females were more resistant to Ampicillin (57.14%). Salmonella species showed higher percentage resistance to commonly used antibiotic agents than Shigella species. The result showed that 8% of Shigella species and 21.5% of Salmonellaspecies were resistant to more than eight antibiotics with multiple antibiotic resistance (MAR) index ranging from 0.2-0.9. Presumptive results of resistance curing treatments showed that the resistance traits were plasmid borne. Agarose gel electrophoresis (AGE) showed plasmids with molecular weights clustered around 23.1kb for species of Salmonella and Shigella. Conjugative transfer of resistance determinants was demonstrated from Salmonella to E. coli and from Salmonella to Shigella but not from Shigella to E. coli or to Salmonella. Studies on Beta-lactamase production showed that 9 (81.82%) of Shigella species and 22 (61.11%) of Salmonella species were Beta-lactamase producers with 3 (27.27%) of Shigella species and 20 (55.56%) of Salmonella species producing extended spectrum Beta-lactamases (ESBLs). ESBLs production is an acknowledge threat to modern medicine which is antibiotic based.
