Prevalence of Escherichia coli in Under-Five Children with Diarrhea in Ethiopia: A Systematic Review and Meta-Analysis

Occurrence, molecular characterization, and antimicrobial susceptibility of sorbitol non-fermenting Escherichia coli in lake water, fish and humans in central Oromia, Ethiopia

Contaminated lake water and fish can be sources of bacterial pathogens of public health concern, including pathogenic E. coli. Within Ethiopia, specifically, Central Oromia, raw fish consumption is a common practice. Although there are few reports on occurrence of E. coli O157 in fish destined for human consumption and children under five years, information on the transmission pathways of E. coli O157 and other sorbitol non-fermenting (SN-F) E. coli from water-to-fish-to-human, and their virulence factors and antimicrobial resistant determinants along the fish supply chain is lacking. The study aimed to investigate the occurrence, molecular characteristics, and antimicrobial susceptibility of E. coli O157 and other SN-F E. coli strains in fish, lake water and humans in central Oromia, Ethiopia. A total of 750 samples (450 fish samples, 150 water samples, 150 human stool samples) were collected from five lakes and three health facilities. The samples were processed following the standard protocol recommended by European Food Safety Authority and Kirby-Bauer disc diffusion method for detection of the bacteria, and antimicrobial susceptibility tests, respectively. Molecular characterization of presumptive isolates was performed using Whole-Genome Sequencing (WGS) for serotyping, determination of virulence factors, antimicrobial resistance traits, and genetic linkage of the isolates. Overall, 3.9% (29/750) of the samples had SN-F E. coli; of which 6.7% (n = 10), 1.8% (n = 8) and 7.3% (n = 11) were retrieved from water, fish, and diarrheic human patients, respectively. The WGS confirmed that all the isolates were SN-F non-O157: H7 E. coli strains. We reported two new E. coli strains with unknown O-antigen from fish and human samples. All the strains have multiple virulence factors and one or more genes encoding for them. Genetic relatedness was observed among strains from the same sources (water, fish, and humans). Most isolates were resistant to ampicillin (100%), tetracycline (100%), cefotaxime (100%), ceftazidime (100%), meropenem (100%), nalidixic acid (93.1%) and sulfamethoxazole/trimethoprim (79.3%). Majority of the strains were resistant to chloramphenicol (58.6%) and ciprofloxacin (48.3%), while small fraction showed resistance to azithromycin (3.45%). Isolates had an overall MDR profile of 87.5%. Majority, (62.1%; n = 18) of the strains had acquired MDR traits. Genes encoding for mutational resistance and Extended-spectrum beta-lactamases (ESBL) were also detected. In conclusion, our study revealed the occurrence of virulent and MDR SN-F E. coli strains in water, fish, and humans. Although no genetic relatedness was observed among strains from various sources, the genomic clustering among strains from the same sources strongly suggests the potential risk of transmission along the supply chain at the human-fish-environment interface if strict hygienic fish production is not in place. Further robust genetic study of the new strains with unknown O-antigens, and the epidemiology of SN-F E. coli is required to elucidate the molecular profile and public health implications of the pathogens.

Risk factors for diarrheagenic Escherichia coli infection in children aged 6-24 months in peri-urban community, Nairobi, Kenya

Escherichia coli commonly inhabits the gut of humans and animals as part of their microbiota. Though mostly innocuous, some strains have virulence markers that make them pathogenic. This paper presents results of a cross-sectional epidemiological study examining prevalence of diarrheagenic E. coli (DEC) pathotypes in stool samples of asymptomatic healthy children (n = 540) in Dagoretti South subcounty, Nairobi, Kenya. E. coli was cultured and pathotyped using PCR to target specific virulence markers associated with Shiga-toxin, enteropathogenic, enterotoxigenic, enteroaggregative, entero-invasive and diffusely adherent E. coli. Overall prevalence of DEC pathotypes was 20.9% (113/540) with enteropathogenic E. coli being the most prevalent (34.1%), followed by enteroaggregative E. coli (23.5%) and Shiga-toxin producing E. coli (22.0%) among positive samples. We found evidence of co-infection with multiple pathotypes in 15% of the positive samples. Our models indicated that at the household level, carriage of DEC pathotypes in children was associated with age group [12-18 months] (OR 1.78; 95%CI 1.03-3.07; p = 0.04), eating matoke (mashed bananas) (OR 2.32; 95%CI 1.44-3.73; p = 0.001) and pulses/legumes (OR 1.74; 95%CI 1.01-2.99; p = 0.046) while livestock ownership or contact showed no significant association with DEC carriage (p>0.05). Our findings revealed significant prevalence of pathogenic DEC circulating among presumptive healthy children in the community. Since there has been no previous evidence of an association between any food type and DEC carriage, unhygienic handling, and preparation of matoke and pulses/legumes could be the reason for significant association with DEC carriage. Children 12-18 months old are more prone to DEC infections due to exploration and hand-to-mouth behavior. A detailed understanding is required on what proportion of positive cases developed severe symptomatology as well as fatal outcomes. The co-infection of pathotypes in the rapidly urbanizing environment needs to be investigated for hybrid or hetero-pathotype circulation that have been implicated in previous infection outbreaks.

Prevalence and drug resistance patterns of Gram-negative enteric bacterial pathogens from diarrheic patients in Ethiopia: A systematic review and meta-analysis

Background

Diarrhoea is the leading cause of morbidity and mortality in the world particularly in developing countries and among vulnerable groups of the population. Gram-negative enteric bacterial pathogens (GNEBPs) are a group of organisms that reside mainly in the intestine and induce diarrhoea. Antimicrobial agents are usually the part of their treatment regimen. The therapeutic effect of antimicrobials is hindered by the emergence and spread of drug-resistant strains. The information regarding the prevalence and antimicrobial resistance patterns of GNEBPs in Ethiopia is limited and found in a scattered form.

Objectives

This study was designed to determine the pooled prevalence and drug resistance patterns of GNEBPs by meta-analysis of data from diarrhoeic patients in Ethiopia.

Method

A comprehensive literature search was conducted through internet searches using Google Scholar, PubMed, Science Direct, HINARI databases, and reference lists of previous studies. Published articles were included in the study based on priorly set inclusion and exclusion criteria. Results were presented in the forest plot, tables, and figures with a 95% confidence interval (CI). The inconsistency index (I²) test statistics was used to assess heterogeneity across studies. The pooled prevalence estimate of GNEBPs and their drug resistance patterns were computed by a random-effects model. Software for Statistics and Data Science (STATA) version 14 statistical software was used for the analysis.

Result

After removing those articles which did not fulfil the inclusion criteria, 43 studies were included in the analysis. Studies were conducted in 8 regions of the country and most of the published articles were from the Amhara region (30.23%) followed by Oromia (18.60%) and Southern Nations, Nationalities, and Peoples’ region (SNNP) (18.60%). The pooled prevalence of GNEBPs was 15.81% (CI = 13.33–18.29). The funnel plot indicated the presence of publication bias. The pooled prevalence of GNEBPs in Addis Ababa, Amhara, SNNP, and Oromia regions were 20.08, 16.67, 12.12, and 11.61%, respectively. The pooled prevalence was 14.91, 18.03, and 13.46% among studies conducted from 2006–2010, 2011–2015, and 2016–2021, respectively and it was the highest (20.35%) in children having age less than or equal to 15 years. The pooled prevalence of Escherichia coli, Campylobacter spp., Shigella spp., and Salmonella enterica were 19.79, 10.76, 6.24, and 5.06%, respectively. Large proportions (60–90%) of the isolates were resistant to ampicillin, amoxicillin, tetracycline, and trimethoprim-sulphamethoxazole. The pooled prevalence of multidrug resistance (MDR) was 70.56% (CI = 64.56–76.77%) and MDR in Campylobacter spp., Shigella spp., E. coli, and S. enterica. were 80.78, 79.08, 78.20, and 59.46%, respectively.

Conclusion

The pooled estimate showed a high burden of GNEBPs infections and a high proportion of drug resistance characters to commonly used antimicrobial agents in Ethiopia. Therefore, performing drug susceptibility tests, establishing an antimicrobial surveillance system and confirmation by molecular techniques are needed.