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

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.

Characterization of Escherichia coli from Water and Food Sold on the Streets of Maputo: Molecular Typing, Virulence Genes, and Antibiotic Resistance

“…The bacterial species E. coli represents one of the main hazards in food and water sources [3,6,7]. However, not all E. coli cause diarrheal diseases [8].…”

“…Its association with the occurrence of diarrhea is based on the presence of genes that encode different virulence factors such as stx, eae, and ehxA in the Shiga toxin-producing E. coli or enterohemorrhagic E. coli (STEC/EHEC), bfp (bundle-forming pilus), and eae (intimin) [8,9]. The presence and/or association of these virulence factors determine the E. coli pathotypes that cause high morbidity and mortality worldwide and are collectively known as diarrheagenic E. coli (DEC) [6,9,10].…”

Real-time multiplex PCR assay reveals the increased prevalence of Campylobacter spp and diarrhoeagenic Escherichia coli in humans from Vellore, South India

“…Similarly, diarrhoeagenic Escherichia coli (DEC) remain another important cause of diarrhoea in developing countries though they are not routinely identified in clinical laboratories worldwide [22][23][24]. Nearly 40 % of diarrhoeal episodes among children <5 years of age are caused by members of the DEC pathotype in low-to middle-income countries [25].…”

Antimicrobial stewardship among Nigerian children: A pilot study of the knowledge, attitude, and practices of prescribers at two tertiary healthcare facilities in Bayelsa State

“…There are gaps in antimicrobial stewardship activities, generally for Nigeria and specifically for children. A review of the literature on AMS in Nigeria failed to show any studies on AMS in children (15)(16)(17)(18)(19)(20)(21).…”