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Background: We aimed to determine the prevalence and genetic characteristics of extended-spectrum beta-lactamase (ESBL)- and carbapenemase-producing Enterobacteriaceae in stools from healthy infants and their mothers, and to determine the risk factors associated with their carriage. Methods & Materials: This study was nested within the Drakenstein Child Health Study, South Africa. Maternal and infant faecal samples were collected at birth and at two additional time-points from the infants. Samples were screened for ESBLs and carbapenemase-producing organisms using ChromID ESBL and ChromID CARBA media, respectively. Vitek 2 was used for antibiotic susceptibility testing and identification of suspect ESBL/carbapenemase-producing isolates. ESBL production was confirmed using the combination disc test, and carbapenemase production using the modified Hodge test. Selected ESBL and carbapenemase genes were characterized by singleplex polymerase chain reaction and Sanger sequencing. Results: Maternal faecal carriage of ESBL-producing bacteria was 4.4%; 4/90 (95% confidence interval (CI): 1.5%-10.2%), and that of infants at birth was 3.5%; 4/116 (95% CI: 1.2%-8.0%). The infant faecal carriage of ESBL-producing bacteria at 5-12 and 20- 28 weeks was 4.4%; 3/68 (95% CI: 1.3%-11.3%) and 5.7%; 2/35 (95% CI: 1.2%-17.1%), respectively. ESBL genes were detected in six K. pneumoniae (blaCTX-M-15), five E. cloacae (blaSHV-12 and blaSHV-5) and three E. coli (blaCTX-M-14) isolates. No carbapenemaseproducing bacteria were identified in this study. Pulsed-field gel electrophoresis showed heterogeneous clones of CTX-M-15-producing K. pneumoniae isolates. In contrast, in a mother-infant pair, we observed clonal relations among ESBL-producing E. cloacae isolates. In addition, one infant was persistently colonized by SHV- 12-producing E. cloacae. Univariate analysis showed that infants born to HIV-positive mother, via elective caesarean section, and medication use before discharge were positively associated with ESBL faecal carriage. In contrast, breastfeeding prior to discharge was negatively associated with ESBL carriage. Conclusion: This is the first study to detect ESBL-producing bacteria inhumanmeconiumsamples in Africa, and raises questions on the source of such isolates and implications for community transmission. Further research is required to determine the spread of ESBL- and carbapenemase-producing bacteria in community settings in South Africa. [ABSTRACT FROM AUTHOR]