title: Antibiotic resistance patterns and beta-lactamase identification in Escherichia coli isolated from young children in rural Limpopo Province, South Africa: The MAL-ED cohort.
abstract: Antibiotic resistance is a growing problem worldwide. Mechanisms of resistance vary, and some can confer resistance to multiple classes of antibiotics.
  
  
  
  To characterise the antibiotic resistance profiles of Escherichia coli isolates obtained from stool samples of young rural children exposed or unexposed to antibiotics.
  
  
  
  The samples were collected from children aged 4 - 12 months who were participants in the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) project at the South Africa research site. We isolated 87 E. coli samples (clones) from 65 individual participants, all of which were subjected to disc diffusion assay to determine resistance. We characterised the minimum inhibitory concentration of antibiotics in a subset of strains as well as the mechanism by which these strains were resistant to beta-lactam antibiotics.
  
  
  
  Our results revealed high resistance rates to co-trimoxazole (54.0%), penicillin (47.1%) and tetracycline (44.8%) in our isolates, and indicated that the beta-lactamase TEM-1 is a prevalent source of beta-lactam resistance. We also identified two isolates with the extended-spectrum beta-lactamase CTX-M-14.
  
  
  
  This study identified antibiotic-resistant E. coli in children with and without prior exposure to antibiotics, with some isolates showing resistance to multiple classes of antibiotics. Clinicians should bear in mind that transmission of extended-spectrum beta-lactamase-resistant E. coli exists at the community level, and that children as young as 2 years may be harbouring these resistant phenotypes.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, Mass., USA; HIV/AIDS & Global Health Research Programme, Department of Microbiology, School of Mathematical and Natural Sciences, University of Venda, Thohoyandou, Limpopo, South Africa. aliciade10@gmail.com.
authors.forename: A S
authors.initials: AS
authors.lastname: DeFrancesco
authors.forename: N F
authors.initials: NF
authors.lastname: Tanih
authors.forename: A
authors.initials: A
authors.lastname: Samie
authors.forename: R L
authors.initials: RL
authors.lastname: Guerrant
authors.forename: P O
authors.initials: PO
authors.lastname: Bessong
mesh_terms: D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000453:epidemiology; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D012424:Rural Population; D013019:South Africa / Q000453:epidemiology; D018440:beta-Lactam Resistance; D001618:beta-Lactamases
chemical_list: C456080:beta-lactamase CTX-M-14; D001618:beta-Lactamases; C034413:beta-lactamase TEM-1