Pathotyping and Antibiotic Resistance Profiling of Escherichia coli Isolates from Children with Acute Diarrhea in Amatole District Municipality of Eastern Cape, South Africa.

S A Omolajaiye,B C Iweriebor,K O Afolabi,Frederick D Quinn

doi:10.1155/2020/4250165

Abstract

Background Diarrhea has been reported as the leading cause of childhood mortality and morbidity globally but with disproportionate impacts in developing nations. Among bacterial etiologic agents of diarrhea, diarrheagenic Escherichia coli is the main cause of the disease among children under the age of 5 years. This study is aimed at determining the prevalence and antibiogram pattern of diarrheagenic Escherichia coli (DEC) pathotypes associated with diarrhea cases in the study area. Methods A total of 120 presumptive isolates of E. coli were obtained from diarrheal stool samples from male and female patients below 12 years of age using chromogenic agar. Confirmation of the isolates and screening for virulence genes were determined by polymerase chain reaction (PCR) while antimicrobial susceptibility testing was performed using the disk diffusion method. The presence of antibiotic resistance genes to chloramphenicol and tetracycline among the confirmed isolates was also profiled by PCR based on the observed phenotypic resistance pattern. Results Of the 120 presumptive isolates, 88.3% (106/120) were confirmed as E. coli through PCR. The molecular pathotyping of the confirmed isolates showed their distribution as 41% (43/106) of diffusely adhering E. coli (DAEC), 17% (18/106) of enterohemorrhagic E. coli (EHEC), 17% (18/106) of enteropathogenic E. coli (EPEC), and 10% (11/106) of enteroinvasive E. coli (EIEC), while enteroaggregative E. coli (EAEC) and enterotoxigenic E. coli (ETEC) were not detected, and the remaining 15% did not belong to any pathotype. Notably, high resistance of the isolates to commonly used antimicrobials was observed as follows: ampicillin (98%), chloramphenicol (94%), trimethoprim-sulfamethoxazole (96%), and tetracycline (90.6%), while a relatively low number of the confirmed isolates were resistant to ciprofloxacin (45%) and imipenem (36%). In addition, 94% of the isolates that exhibited phenotypic resistance against chloramphenicol harbored the catA1 resistance gene while 89% that showed resistance to tetracycline had tetA genes. Conclusions These findings showed that DEC could be considered as the leading etiologic bacterial agent responsible for diarrhea in the study community, and the observable high degree of resistance of the isolates to antimicrobial agents is of huge significance, calling for stakeholders to adopt and consolidate the existing antimicrobial stewardship scheme of the government, in order to ensure an uncompromised public health.

Highlights

Diarrhea has been described as one of the leading causes of illness and death in children under the age of 5 years, predominantly in underdeveloped countries [1]
A total of 120 presumptive isolates of E. coli were obtained from the diarrheal stool samples collected from both outpatients and inpatients attending or admitted in private and public hospitals in the Amatole District Municipality of Eastern Cape Province
Out of the 120 presumptive isolates, 106 were confirmed as E. coli through polymerase chain reaction (PCR) (Figure 1), representing 88.3% of the total presumptive isolates

Summary

Introduction

Diarrhea has been described as one of the leading causes of illness and death in children under the age of 5 years, predominantly in underdeveloped countries [1]. There has been a reduction in the childhood death rates worldwide in recent years as a result of oral rehydration therapy. The prevalence of this disease has been clearly associated with contributory factors such as untimely weaning of children from breast feeding, drinking of unsafe water, encouraging bottle-feeding, and malnutrition [3]. Among bacterial etiologic agents of diarrhea, diarrheagenic Escherichia coli is the main cause of the disease among children under the age of 5 years. These findings showed that DEC could be considered as the leading etiologic bacterial agent responsible for diarrhea in the study community, and the observable high degree of resistance of the isolates to antimicrobial agents is of huge significance, calling for stakeholders to adopt and consolidate the existing antimicrobial stewardship scheme of the government, in order to ensure an uncompromised public health

Objectives

Methods

Results

Conclusion