Molecular epidemiology and antimicrobial susceptibility of diarrheagenic Escherichia coli isolated from children under age five with and without diarrhea in Central Ethiopia

BACKGROUND

Diarrhea is a serious health problem in children, with the highest mortality rate in sub-Saharan Africa. Diarrheagenic Escherichia coli (DEC) is among the major bacterial causes of diarrhea in children under age five. The present study aims to determine molecular epidemiology and antimicrobial resistance profiles of DEC and identify contributing factors for acquisition among children under age five in Central Ethiopia.

METHODS

A health facility-centered cross-sectional study was conducted in Addis Ababa and Debre Berhan, Ethiopia, from December 2020 to August 2021. A total of 476 specimens, 391 from diarrheic and 85 from non-diarrheic children under age five were collected. Bacterial isolation and identification, antimicrobial susceptibility, and pathotype determination using polymerase chain reaction (PCR) were done.

RESULTS

Of the 476 specimens analyzed, 89.9% (428/476) were positive for E. coli, of which 183 were positive for one or more genes coding DEC pathotypes. The overall prevalence of the DEC pathotype was 38.2% (183/476). The predominant DEC pathotype was enteroaggregative E. coli (EAEC) (41.5%, 76/183), followed by enterotoxigenic E. coli (21.3%, 39/183), enteropathogenic E. coli (15.3%, 28/183), enteroinvasive E. coli (12.6%, 23/183), hybrid strains (7.1%, 13/183), Shiga toxin-producing E. coli (1.6%, 3/183), and diffusely-adherent E. coli (0.6%, 1/183). DEC was detected in 40.7% (159/391) of diarrheic and 28.2% (24/85) in non-diarrheic children (p = 0.020). The majority of the DEC pathotypes were resistant to ampicillin (95.1%, 174/183) and tetracycline (91.3%, 167/183). A higher rate of resistance to trimethoprim-sulfamethoxazole (58%, 44/76), ciprofloxacin (22%, 17/76), ceftazidime and cefotaxime (20%, 15/76) was seen among EAEC pathotypes. Multidrug resistance (MDR) was detected in 43.2% (79/183) of the pathotypes, whereas extended spectrum ß-lactamase and carbapenemase producers were 16.4% (30/183) and 2.2% (4/183), respectively.

CONCLUSION

All six common DEC pathotypes that have the potential to cause severe diarrheal outbreaks were found in children in the study area; the dominant one being EAEC with a high rate of MDR.

Frequency of five Escherichia Coli pathotypes in Iranian adults and children with acute diarrhea

Background

Knowledge about the distribution of Escherichia Coli (E. coli) pathotypes in Iran is limited. This nation-wide survey aims to provide a comprehensive description of the distribution of five pathogenic E. coli in Iran.

Methods

Stool samples were collected from 1,306 acute diarrhea cases from 15 provinces (2013–2014). E. coli-positive cultures underwent PCR testing for the detection of STEC, ETEC, EPEC, EAEC, and EIEC pathotypes. Pathotype frequency by province, age-group, and season was estimated.

Results

979 diarrhea samples (75.0%) were culture-positive for E. coli (95% CI: 72.6, 77.3%), and 659 (50.5%) were pathogenic E. coli (95% CI: 47.8, 53.2%). STEC was the most frequent pathotype (35.4%). ETEC (14.0%) and EPEC (13.1%) were the second and the third most frequent pathotypes, respectively. EAEC (4.3%) and EIEC (0.3%) were not highly prevalent. Fars (88.7%) and Khorasan-e-Razavi (34.8%) provinces had the highest and lowest frequencies, respectively. E. coli pathotypes were more frequent in warmer than cooler seasons, showed the highest frequency among children under five years of age (73%), and had no significant association with participants’ gender.

Conclusions

Diarrheagenic E. coli may be an important cause of acute diarrhea in adults and children in Iran. STEC and ETEC seem to be widespread in the country with a peak in warmer seasons, impacting the recommended use of seasonal STEC and ETEC vaccines, especially in high-risk groups. Monitoring the incidence of E. coli pathotypes, serotypes, and antibiotic resistance over time is highly recommended for evaluation of interventions.

Characterization and Antibiotic Susceptibility Profiles of Pathogenic Escherichia Coli Isolated from Diarrhea Samples within the Buffalo City Metropolitan Municipality, Eastern Cape, South Africa

Objectives:

Developing countries like South Africa are still faced with numerous challenges such as poor environmental sanitation, lack of clean drinking water and inadequate hygiene which have contributed largely to diarrheal infections and deaths in children. This study was aimed at investigating the prevalence of pathotypes, antimicrobial resistance and drug resistance determinants among Escherichia coli (E. coli) isolates from diarrhea stool samples within Buffalo City Municipality, Eastern Cape, South Africa.

Methods:

Fresh diarrheal stool samples were collected from 140 patients attending public health centres within the Municipality and presumptive E. coli isolates were obtained from the stool samples using E. coli chromogenic agar while PCR amplification methods were used to confirm the presumptive isolates as well as delineate them into pathotypes based on the presence of certain virulence genes. In addition, antimicrobial susceptibility and screening of some of the antimicrobial resistant determinants were performed on all the confirmed isolates.

Results:

A total of 394 presumptive E. coli isolates from 140 diarrhea stool samples were subjected to polymerase chain reaction amplification, of which 265 were confirmed positive as E. coli. Pathotypes delineation of the positive E. coli isolates validated the presence of ETEC 106 (40%), EAEC 48 (18%), DAEC 37 (14%), and EPEC 31 (11%) while no EIEC pathotype was detected. All E. coli isolates exhibited maximum susceptibility to gentamicin (95%), amikacin (91%), nitrofurantoin (91%), meropenem (90%), chloramphenicol (91%) norfloxacin (84%) and imipenem (83%). However, the isolates showed multidrug resistance to penicillin G, ampicillin, trimethoprim, tetracycline, doxycycline, and erythromycin, with over 71% of the isolates resistant to the drugs. The prevalence and distribution of the five resistance determinants assessed were as follow; sulphonamides; sulII (12%), beta lactams; [ampC (22%); blaTEM, (25%)], and tetracyclines (tetA (35%).

Conclusion:

The results from this study suggest the probable involvement of E. coli pathotypes as an etiologic agent of diarrhea in the study area and revealed high levels of multidrug resistance among the isolates, which could be a major health burden.

Diarrhoeagenic Escherichia coli in mother-child Pairs in Ile-Ife, South Western Nigeria

Background

Diarrhoeagenic Escherichia coli (DEC) pathotypes are among the most common bacterial causes of morbidity and mortality in young children. These pathogens are not sought routinely and capacity for their detection is limited in Africa. We investigated the distribution and dissemination of DEC in 126 children paired with their mothers in a Nigerian community.

Methods

A total of 861 E. coli were isolated from 126 children with diarrhoea and their mothers. Antimicrobial susceptibility of each isolate was determined by Kirby-Bauer disc diffusion technique. All the isolates were screened for DEC markers by multiplex PCR. Genetic relatedness of DEC strains was determined by flagellin typing and Insertion element 3 (IS3)-based PCR.

Results

DEC were identified from 35.7 % of individuals with the most common pathotype being shiga toxin-producing E. coli (42, 16.7 %). Identical pathotypes were found in 13 (10.3 %) of the mother-child pairs and in three of these strains from mothers and their children showed identical genetic signatures. Over 90 % of DEC isolates were resistant to ampicillin, sulphonamide, tetracycline, streptomycin or trimethoprim, but only 9 (7.2 %) were ciprofloxacin resistant

Conclusion

The data suggest that healthy mothers are asymptomatic reservoirs of multiply-resistant strains that are pathogenic in their children and there are instances in which identical strains are found in mother-child pairs.