Enteric Bacterial Pathogens in Children with Diarrhea in Niger: Diversity and Antimicrobial Resistance

Abstract

BackgroundAlthough rotavirus is the leading cause of severe diarrhea among children in sub-Saharan Africa, better knowledge of circulating enteric pathogenic bacteria and their antimicrobial resistance is crucial for prevention and treatment strategies.Methodology/Principal FindingsAs a part of rotavirus gastroenteritis surveillance in Maradi, Niger, we performed stool culture on a sub-population of children under 5 with moderate-to-severe diarrhea between April 2010 and March 2012. Campylobacter, Shigella and Salmonella were sought with conventional culture and biochemical methods. Shigella and Salmonella were serotyped by slide agglutination. Enteropathogenic Escherichia coli (EPEC) were screened by slide agglutination with EPEC O-typing antisera and confirmed by detection of virulence genes. Antimicrobial susceptibility was determined by disk diffusion. We enrolled 4020 children, including 230 with bloody diarrhea. At least one pathogenic bacterium was found in 28.0% of children with watery diarrhea and 42.2% with bloody diarrhea. Mixed infections were found in 10.3% of children. EPEC, Salmonella and Campylobacter spp. were similarly frequent in children with watery diarrhea (11.1%, 9.2% and 11.4% respectively) and Shigella spp. were the most frequent among children with bloody diarrhea (22.1%). The most frequent Shigella serogroup was S. flexneri (69/122, 56.5%). The most frequent Salmonella serotypes were Typhimurimum (71/355, 20.0%), Enteritidis (56/355, 15.8%) and Corvallis (46/355, 13.0%). The majority of putative EPEC isolates was confirmed to be EPEC (90/111, 81.1%). More than half of all Enterobacteriaceae were resistant to amoxicillin and co-trimoxazole. Around 13% (46/360) Salmonella exhibited an extended-spectrum beta-lactamase phenotype.ConclusionsThis study provides updated information on enteric bacteria diversity and antibiotic resistance in the Sahel region, where such data are scarce. Whether they are or not the causative agent of diarrhea, bacterial infections and their antibiotic resistance profiles should be closely monitored in countries like Niger where childhood malnutrition pre-disposes to severe and invasive infections.

Antibiotic Susceptibility Profile of Escherichia coli and Salmonella Causing Childhood Diarrhoea in Awka Municipality, South-eastern Nigeria

“…In line with our results, similar sensitive response to the flouroqunolones was equally reported by Eseigbe et al [24]. Contrary to our results, in Niger Langendorf et al, [26] reported that most of the diarrheic E. coli and Salmonella were sensitive to antibiotics tested except amoxicillin and co-trimoxazole. Guerra et al [27] also reported no resistance to ceftriaxone, ceftazidime and cefepime by Enterotoxigenic Escherichia coli clinical isolates from Northern Colombia.…”

“…In line with our finding, a similar high ESBL-producing was recorded of Escherichia coli isolated from Children with Acute Diarrhoea in Wrocław, Poland [31]. The high prevalence of ESBL-producing among the E. coli isolates is a big concern as they might show a false sensitive zone of inhibition in the Kirby-Bauer disk diffusion method and often remain undetected by routine susceptibility tests [26,32]. The prevalence of ESBL producing E. coli varies from country to country and from center to center.…”

Diarrheagenic Escherichia coli

“…However, other studies still report tEPEC being more prevalent than aEPEC as a cause of diarrhea 116 . In addition, in some less developed areas (Africa and Asia), tEPEC are still some of the most important enteropathogens 117, 118, 119, 120, 121, 122. Based on the recently completed Global Enteric Multicenter Study (GEMS) involving children less than 5 years of age from seven sites in Africa and Asia, tEPEC was significantly associated with moderate to severe diarrhea in children under 2 years of age in Kenya, whereas aEPEC was not associated with this type of diarrhea 118 …”

Clinical and Laboratory Characteristics of Pediatric Campylobacter spp. Acute Gastroenteritis

“…Viruses, bacteria, and parasites are the three main groups of agents that produce AGE in children, with viruses accounting for over 80% in this population (2). The most common bacteria responsible for AGE in children are Escherichia coli, Shigella, Salmonella, and Campylobacter, and they can cause serious gastrointestinal and non-gastrointestinal complications despite their lower incidence than viral factors (6,7).…”