Characterisation of Staphylococci species from neonatal blood cultures in low- and middle-income countries

Abstract

AbstractBackgroundIn low- and middle-income countries (LMIC)Staphylococcus aureusis regarded as one of the leading bacterial causes of neonatal sepsis, however there is limited knowledge on the species diversity and antimicrobial resistance caused by Gram-positive bacteria (GPB).MethodsWe characterised GPB isolates from neonatal blood cultures from LMICs in Africa (Ethiopia, Nigeria, Rwanda, and South Africa) and South-Asia (Bangladesh and Pakistan) between 2015–2017. We determined minimum inhibitory concentrations and performed whole genome sequencing (WGS) on Staphylococci isolates recovered and clinical data collected related to the onset of sepsis and the outcome of the neonate up to 60 days of age.ResultsFrom the isolates recovered from blood cultures, Staphylococci species were most frequently identified. Out of 100S. aureusisolates sequenced, 18 different sequence types (ST) were found which unveiled two small epidemiological clusters caused by methicillin resistantS. aureus(MRSA) in Pakistan (ST8) and South Africa (ST5),both with high mortality (n = 6/17). One-third ofS. aureuswas MRSA, with methicillin resistance also detected inStaphylococcus epidermidis, Staphylococcus haemolyticusandMammaliicoccus sciuri.Through additional WGS analysis we report a cluster ofM. sciuriin Pakistan identified between July-November 2017.ConclusionsIn total we identified 14 different GPB bacterial species, however Staphylococci was dominant. These findings highlight the need of a prospective genomic epidemiology study to comprehensively assess the true burden of GPB neonatal sepsis focusing specifically on mechanisms of resistance and virulence across species and in relation to neonatal outcome.