Prevalence of antibiotic resistance in commensal Escherichia coli among the children in rural hill communities of Northeast India

Abstract

Commensal bacteria are the representative of the reservoir of antibiotic resistance genes present in a community. The usage of antibiotics along with the demographic factors is generally associated with an increase in antibiotics resistance in pathogens. Northeast (NE) India is untapped with regard to antibiotic resistance prevalence and spread. In the current study, the prevalence of antibiotic-resistant commensal Escherichia coli in pre-school and school-going children (n = 550, 1-14 years old) from the rural areas of the state of Sikkim-an NE Indian state, with respect to associated demographic factors was investigated. A total of 550 fecal E. coli isolates were collected during July 2015 to June 2017. A structured questionnaire was used to collect data to ascertain the potential factors associated with the carriage of antibiotic resistance E. coli among the children. Statistical analysis along with a logistic regression identified potential external factors affecting the observed antibiotic resistance pattern. The data indicated a high prevalence of resistance to common antibiotics like ampicillin (92%), ceftazidime (90%), cefoxitin (88%), streptomycin (40%) and tetracycline (36%), but no resistance to chloramphenicol. The resistance to the combination of penicillin and quinolone group of antibiotics was observed in fifty-two percent of the isolates. A positive correlation between the harboring of antibiotics resistant E. coli with different demographic factors was observed such as, with children living in nuclear family (vs joint family 63.15%, OR 0.18, 95% CI:0.11-0.28, p < 0.01), below higher secondary maternal education (vs college graduates 59.27% OR 0.75, 95% CI:0.55-1.02, p < 0.02). A close association between different demographic factors and the high prevalence of antibiotic-resistant commensal E. coli in the current study suggests a concern over rising misuse of antibiotics that warrants a future threat of emergence of multidrug-resistant pathogen isolates.

Fig 1. Study design.

Informed written consent from parents/guardians were procured on the proforma (S1 File). Total 586 stool samples were collected from children of age group 1–14 years. Of the 586 stool samples, 36 stool samples were excluded as no definitive E. coli isolates could be cultured from those samples. A total of 550 E. coli isolates from 550 samples were used for the analysis.

Fig 2. Demographic details of community participants.

Demographic details of community participants and their families are represented as a percentage of the population against the total population (N = 550). a: ‘Nuclear family’ referred to those families having only parents and children living in one household premises and ‘Joint family’ referred to the families having parents, children and their relatives living in one household premises; b = Family below poverty line refers to those families having possession of “Below Poverty Line (BPL)’ card issued by Government of India (GOI); c = Scheduled castes, backward castes and scheduled tribes are special status groups of socially and economically deprived classes of people as defined by the GOI; I: Gender of Children; II: Family type; III: Economic status; IV: Caste; V: Number of family members; VI: Paternal education; VII: Maternal education; VIII: Maternal occupation; IX: Antibiotics used last month.

Fig 3. Resistance pattern of E. coli isolates against individual antibiotics.

Fig 4. Resistance pattern of E. coli isolates against a combination of antibiotics.

(Group A = Penicillin, B = Quinolones/Fluoroquinolones, C = Cephalosporin, D = Carbapenem, E = Aminoglycosides, F = Tetracycline, G = Polypeptide).

Fig 5. Association of the antibiotic resistance prevalence (%) in E. coli with demographic variables.

The data displays the observed antibiotic resistance in E. coli isolates from, (A) male and female, (B) children living in joint and nuclear families, (C) children with their mother having education up to graduate and higher secondary level and (D) children with prior antibiotic exposures. The potential association between demographic variables and antibiotic resistance pattern observed for the isolates was evaluated using chi-square analysis and multivariate logistic regression. *Statistically significant by chi-square analysis (p < 0.01); ** statistically significant by multivariate logistic regression.

Fig 6. Cluster analysis representing the relationship between demographic factors and pattern of antibiotic resistance.

It formed three distinct groups/clusters based on the antibiotic resistance pattern. Group 1 represents the E. coli isolates from male and female which showed similar resistance pattern. Group 2 represents the demographic factors which make children more prone to carry antibiotic-resistant commensal E. coli. Group 3 represents the demographic factor associated with least antibiotic resistance.