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

Abstract

Background In low- and middle-income countries (LMIC) Staphylococcus aureus is 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). Methods We 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. Results From the isolates recovered from blood cultures, Staphylococci species were most frequently identified. Out of 100 S. aureus isolates sequenced, 18 different sequence types (ST) were found which unveiled two small epidemiological clusters caused by methicillin resistant S. aureus (MRSA) in Pakistan (ST8) and South Africa (ST5), both with high mortality (n = 6/17). One-third of S. aureus was MRSA, with methicillin resistance also detected in Staphylococcus epidermidis, Staphylococcus haemolyticus and Mammaliicoccus sciuri. Through additional WGS analysis we report a cluster of M. sciuri in Pakistan identified between July-November 2017. Conclusions In 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.

Association of multilocus sequencing types and antimicrobial resistance profiles of methicillin-resistant Mammaliicoccus sciuri in animals in Southern Thailand

“…Therefore, we suggest that this clone is of concern in Thailand. Another clone of concern is ST81, which has been reported in a neonatal infection in Bangladesh [ 6 ]. In this case, zoonotic infections must be classified and monitored to protect humans in Thailand.…”

“…Mammaliicoccus sciuri (or S. sciuri ) is a gram-positive and coagulase-negative cocci commonly found in the environment, humans, and animals [ 2 – 4 ]. Furthermore, it is an opportunistic bacterium capable of causing severe human infections [ 5 , 6 ]. Mammaliicoccus sciuri has been discovered in various healthy and unhealthy animals, particularly ruminants [ 3 – 5 , 7 , 8 ].…”

The Role of Coagulase-Negative Staphylococci Biofilms on Late-Onset Sepsis: Current Challenges and Emerging Diagnostics and Therapies

“…In high-income countries, the most frequent causative agents of LOS, especially in extremely and very low birth weight infants, are coagulase-negative staphylococci (CoNS) [ 21 , 26 , 27 , 28 , 29 , 30 ], accounting for 53 to 78% of the LOS cases [ 21 ]. In low- and middle-income countries, although CoNS are still responsible for about 35 to 47% of LOS, Staphylococcus aureus , Klebsiella pneumoniae and Escherichia coli show higher incidence [ 31 , 32 , 33 ]. However, the lack of studies in low- and middle-income countries makes accurate estimations difficult.…”