Etiology of Acute Diarrhea in Children and Adults in Tunis, Tunisia, with Emphasis on Diarrheagenic Escherichia coli: Prevalence, Phenotyping, and Molecular Epidemiology

Abstract

A total of 271 stool specimens were collected from children (diarrheagenic, n = 115 and control, n = 54) and adults (diarrheagenic, n = 73 and control, n = 29) from Tunis, Tunisia, and processed to detect bacterial enteropathogens, parasites, and viruses. Diarrheagenic Escherichia coli (DEC) were identified by their virulence genes (polymerase chain reaction) and adherence patterns (tissue culture assays). The most frequently isolated enteric pathogens from diarrheagenic children were enterotoxigenic E. coli (ETEC, 32.3%), enteroaggregative E. coli (EAEC, 11.3%), enteroinvasive E. coli (EIEC, (11.3%), adenovirus (10.4%), enterohemorrhagic E. coli (EHEC, 10.4%), and Salmonella spp. (9.5%). For children in the control group, ETEC (37%), EAEC (15%), EHEC (11.1%), and typical enteropathogenic E. coli (EPEC, 11.1%) were the most common enteric pathogens. In adults in the diarrheagenic group, Salmonella spp. (34.2%), ETEC (12.3%), adenovirus (7%), and Shigella spp. (4%) were the most common enteric pathogens. In adults in the control group, ETEC (31%) was the most common enteric pathogen. Multiple pathogens were recovered from 22% of the diarrheagenic children and 7% of the diarrheagenic adults. Escherichia coli strains showed high resistance rates to tetracycline, streptomycin, and beta-lactams. The most frequent combinations were ETEC-rotavirus and ETEC-adenovirus. Pulsed-field gel electrophoresis for DEC indicated a large number of DEC clones (five major clones) persistent in the community reservoir for a considerable period of time that caused diarrhea in the population. This suggests the confluence of small epidemics by clonally related DEC strains circulating in this region.

Enteroaggregative Escherichia coli in diarrheic children in Egypt: molecular characterization and antimicrobial susceptibility

“…A significant association of EAEC with diarrheic children one year of age or younger compared with diarrheic children older than one year of age (p < 0.03) was observed as part of this study. Al-Gallas et al in Tunisia reported similar findings [27]. Substantial proportions of DEC were isolated from breastfed children (76.5%) in this study.…”

“…In the present work, only EPEC, ETEC, and EAEC were detected in stool samples, with only EAEC being significantly found in diarrheic children (30.7%) compared with controls (9.3%) (p < 0.01). Compared with our findings, lower prevalence rates of EAEC from diarrheic children have been reported from Iraq (8%), Kuwait (2.6%), Libya (4.1%), and Tunisia (11.3%) [24][25][26][27].…”

Aetiology, epidemiology and clinical characteristics of acute moderate-to-severe diarrhoea in children under 5 years of age hospitalized in a referral paediatric hospital in Rabat, Morocco

“…A low number of parasitic infections have been described in studies of the aetiology of diarrhoea in the Maghreb area (Al-Gallas et al, 2007). This low prevalence was confirmed in our series, in which only two parasitic infections (G. intestinalis, Entamoeba histolytica) were detected, being lower than that observed in a previous study performed in the same hospital with identical methodologies, in which a total of 10 G. intestinalis isolates were detected in a series of 63 children (15.9 %) with stature-ponderal delay (Oudaïna et al 2009).…”

“…Although some data on the aetiological causes of diarrhoea in some North African countries are available (Al-Gallas et al, 2007;Hassine-Zaafrane et al, 2011SdiriLoulizi et al, 2009SdiriLoulizi et al, , 2011, little is known about the aetiology and epidemiology of diarrhoea in Morocco. The latest estimates suggest that diarrhoea may be responsible for the death of 36 per 1000 live births annually in Morocco (UNICEF/WHO, 2009).…”

In-vitro antimicrobial susceptibility testing of bacteria causing diarrhea in children at Khartoum StateSudan

“…Diarrhea is defined as an intestinal disorder characterized by abnormal fluidity and frequency of faecal evacuations, usually at least three times in a 24-hour period. Bloody diarrhea refers to any diarrhea episode in which the loose or watery stools contain visible red blood [1][2][3]. Compared with watery diarrhea, bloody diarrhea generally lasts longer, associated with more complications, more likely to adversely affect a child's growth, and has a higher case fatality rate [2][3][4].…”