Antimicrobial Resistant Escherichia Coli Genes In Children Aged Below Five Years Presenting With Diarrhoea At Thika Level 5 Hospital, Kiambu County, Kenya

ABSTRACT

Diarrhoea is one of the leading causes of illness and death among children in

developing countries, where an estimated 1.3 billion episodes and 4 to 10 million

deaths occur each year in children less than 5 years of age. The study envisioned to

determine the genetic basis of extended spectrum β-lactam (ESBL) resistance in E.

coli isolated from children aged below 5 years attending Thika Level 5 Hospital

Kiambu County in Kenya. Faecal samples were obtained from 384 children

presenting with diarrhoea. A questionnaire was used to collect data concerning the

age of the child, gender and additional information recorded included on history of

hospitalization and antibiotic use. Samples were sub-cultured on MacConkey agar

and suspect E. coli isolates identified. Antimicrobial susceptibility profiles were

determined for the most common antimicrobials against Gram-negative bacteria.

The types and prevalence of Extended-Spectrum βeta-Lactamases were also

determined. Polymerase Chain Reaction methods were used for detection of the

Extended-Spectrum βeta-Lactamases genes and carriage of integrons. Conjugation

experiments were performed to determine the potential of horizontal transfer of

resistance genes. The plasmid content for defining diversity of plasmid replicon

types was also determined among donors and transconjugants. Approximately

25% of all isolates were resistant to ampicillin, tetracycline, chloramphenicol,

streptomycin, amikacin sulphamethoxazole-trimethoprim and amoxicillinclavulanic

acid (p=0.0051; OR=2.27; 95% CI: 2.01-2.33). Isolates (50%) had a

Minimum Inhibitory Concentration mode50 value within the resistance range

except for ceftazidime, Gentamicin, chloramphenicol, Nalidixic acid, Ciproflocin

and Kanamycin. Factors identified to predispose children to carry highly resistant

isolates included recent history of hospitalization and antimicrobial use and having

acute diarrhoea (p=0.0026; OR=4.21; 95% CI: 3.76-4.98 ) There was no

significant difference in antimicrobial resistance patterns for isolates from rural

and urban children (p=0.049). Carriage of a combination of blaCTX-M+ blaTEM or a

combination of blaCTX-M+blaOXA genes was highly associated with resistance to

multiple β-lactams (p=0.00015; OR=2.31; 95% CI: 1.99-2.65). Isolates with

multiple β-lactamases were also likely to carry integrons encoding resistance to

other antimicrobials. Plasmids that mediated resistance to most antimicrobials

belonged to incL/M, HI2 and F-type. In conclusion, most of isolates recovered

from these children were resistant to first line treatment for diarrhoea and therefore

a need to revise the existing empiric treatment of E. coli infections. Resistance was

transferrable via conjugation and integrons were significantly implicated in

resistance dispersion hence increase in the prevalence of multidrug resistant

isolates (p=0.0017; OR: 4.03; 95% CI: 3.81- 4.04). There is a need to encourage

parents and doctors to follow the treatment guidelines for diarrhoea in which case,

the oral re-hydration therapy zinc and vitamin C rather than antibiotics should be

administered in cases of watery bacillary diarrhoea, implement proper

antimicrobial use polices and launch national surveillance programs to monitor emergence and spread of MDR isolates.