Molecular characterisation of extended-Spectrum-Beta-lactamase-producing Klebsiella pneumoniae among children and chicken in the rural Korogwe District, Tanzania

Klebsiella pneumoniae expressing Extended-Spectrum-Beta-Lactamases (ESBLs) are a significant global public health challenge, affecting humans and livestock. However, the molecular epidemiology and relatedness between isolates from human and livestock reservoirs in Tanzania have not been well studied. This study aimed to address this knowledge gap by conducting a cross-sectional analysis in the Korogwe district, Tanzania. Klebsiella pneumoniae complex isolates were collected from children with and without diarrhoea and from chickens in commercial and smallholder farms. ESBL-positive isolates were subsequently tested for phenotypic resistance and analysed by whole-genome sequencing. ESBL-positive K. pneumoniae complex isolates were encountered from children with diarrhoea, 14% (n/ N = 37/259), and 7% (n/ N = 17/258) without diarrhoea. For chicken isolates, 10% (n/ N = 38/371) of the commercial and 5% (n/ N = 21/406) of the smallholder farms were ESBL-positive. The sequenced ESBL-positive isolates from humans and chickens comprised 73% (n/ N = 69/95) K. pneumoniae , 14% (n/ N = 13/95) K. quasipneumoniae subsp. quasipneumoniae , 13% (n/ N = 12/95) K. quasipneumoniae subsp. similipneumoniae , and 1% (n/N = 1/95) K. quasivariicola . A broad variety of sequence types was observed, with 15 clusters of clonal identity identified, mostly in chickens from the same farm. Our findings also showed 68 isolates with 44 distinct capsular types. bla CTX-M-15 was the most commonly identified ESBL-expressing gene. In conclusion, the study highlights the possibility of interspecies transmission of ESBL-positive K. pneumoniae complex isolates between humans and chickens in the study area, emphasising the need for integrated One Health strategies to mitigate the spread of antimicrobial resistance in Tanzania.