Molecular Characterization and Antimicrobial Resistance of Pathogenic Escherichia coli Strains in Children from Wolaita Sodo, Southern Ethiopia

Abstract

Introduction: Pathogenic Escherichia coli strains cause diarrheal infection in children due to their virulence factors. A nonanalytical observational study followed by a purposive sampling technique was conducted from October 2017 to June 2018, to determine the antimicrobial susceptibility patterns and molecularly detect pathogenic Escherichia coli strains in under-five children at Wolaita Sodo town using molecular and the Kirby-Bauer disc diffusion method.

Result: In the current investigation, out of 110 stool samples, Escherichia coli was isolated in 68 (61.8%) (95% CI: 52.1-70.9%). Out of 68 Escherichia coli isolates, 61.9% of Escherichia coli isolates were resistant, 9.4% were intermediately resistant, and 28.7% were susceptible. Among the antimicrobial agents, 91.2% of Escherichia coli isolates were highly sensitive to ciprofloxacin followed by norfloxacin (86.8%). Virulence genes were detected in 55.9% (38/68) (95% CI 52.1%-70.9%) of isolates. The following genes were detected: stx1 (6 (8.8%)), stx2 (4 (5.9%)), eaeA (5 (7.4%)), eaat (14 (20.5%)), and St (4 (5.9%)). Out of 68 Escherichia coli isolates, 43 (63.2%) isolates had shown multidrug resistance patterns. Furthermore, 11.8% of Escherichia coli isolates had shown resistance to eight different drugs. The multidrug resistance index value of Diarrheagenic Escherichia coli pathotypes was greater than or equal to 0.4, which indicates the high risk of resistance.

Conclusion: This study demonstrated important pathogenic Escherichia coli strains and multidrug resistance in isolates containing virulence genes. Wise use of antimicrobials and improving the hygienic practices amongst parents of children reduce its occurrence. Therefore, appropriate usage of antimicrobial agents should also be highly practiced in hospitals.

Figure 1

Map of the study area.

Figure 2

Amplification of eae gene in Escherichia coli isolates from diarrheic children: M Marker (100 bp DNA ladder) P positive control, Lane No. h10 and h41 indicate positive samples, Lane No. h2-h5, and h43-h44 indicates negative samples and N negative control.

Figure 3

Amplification of stx1 gene in Escherichia coli isolates from diarrheic children: M Marker (100 bp DNA ladder) P positive control, Lane No. h23, h39, and h49 indicate positive samples, Lane No. h8, h40, h41, h47, h48, h49, h51, and h52 indicates negative samples and N negative control.

Figure 4

Amplification of stx2 gene in Escherichia coli isolates from diarrheic children: M Marker (100 bp DNA ladder) P positive control, Lane No. h5, and h10 indicates positive samples, Lane No. h3, h4, h6, h15, h16, and h20–h25 indicates negative samples and N negative control.

Figure 5

Amplification of dae gene in Escherichia coli isolates from diarrheic children: M marker (100 bp DNA ladder) P positive control, lane no. h23, and h25 indicates positive samples, lane no. h1, h2, and h26–h33 indicates negative samples and N negative control.