Population Structure of Staphylococcus aureus from Remote African Babongo Pygmies

Abstract

BackgroundPandemic community-acquired methicillin-resistant Staphylococcus aureus isolates (CA-MRSA) predominantly encode the Panton-Valentine leukocidin (PVL), which can be associated with severe infections. Reports from non-indigenous Sub-Saharan African populations revealed a high prevalence of PVL-positive isolates. The objective of our study was to investigate the S. aureus carriage among a remote indigenous African population and to determine the molecular characteristics of the isolates, particularly those that were PVL-positive.Methodology/Principal FindingsNasal S. aureus carriage and risk factors of colonization were systematically assessed in remote Gabonese Babongo Pygmies. Susceptibility to antibiotics, possession of toxin-encoding genes (i.e., PVL, enterotoxins, and exfoliative toxins), S. aureus protein A (spa) types and multi-locus sequence types (MLST) were determined for each isolate. The carriage rate was 33%. No MRSA was detected, 61.8% of the isolates were susceptible to penicillin. Genes encoding PVL (55.9%), enterotoxin B (20.6%), exfoliative toxin D (11.7%) and the epidermal cell differentiation inhibitor B (11.7%) were highly prevalent. Thirteen spa types were detected and were associated with 10 STs predominated by ST15, ST30, ST72, ST80, and ST88.ConclusionsThe high prevalence of PVL-positive isolates among Babongo Pygmies demands our attention as PVL can be associated with necrotinzing infection and may increase the risk of severe infections in remote Pygmy populations. Many S. aureus isolates from Babongo Pygmies and pandemic CA-MRSA-clones have a common genetic background. Surveillance is needed to control the development of resistance to antibiotic drugs and to assess the impact of the high prevalence of PVL in indigenous populations.

Population structure and exotoxin gene content of methicillin-susceptible Staphylococcus aureus from Spanish healthy carriers

“…50%) [61,62]. Interestingly, the genetic background ST121, t159, agrIV (CC121) was found among isolates from healthy carriers in Asturias and from a remote African pygmy in Gabon, but the African isolate harboured lukPV [63]. Due to the common genetic background, there is a certain risk for European MSSA to acquire the PantoneValentine leukocidin genes.…”

Community-Associated Methicillin-Resistant Staphylococcus aureus Case Studies

“…Furthermore, it has been suggested that PVL + MSSA, often detected at high frequency in parts of Africa, may have acted as a reservoir for CA-MRSA [80, 81]. The emergence of methicillin-resistance is to not exclusively linked PVL-positive MSSA as for example USA300 appears to have evolved from a USA500 progenitor where the acquisition of PVL was one of the last steps in this process [82].…”

“…The nasal S. aureus carriage in the remote indigenous Gabonese Babongo Pygmies was about 30 % and no MRSA was detected [81]. ST30 was most common (24 %) among the ten diverse sequence types, which also included ST15, ST72, ST80, and ST88 (Table 2) and more than half of all isolates carried PVL.…”

Is Africa the origin of major Haitian Staphylococcus aureus lineages?

“…7 This further supports the 'out of Africa' hypothesis of certain pandemic S. aureus clones, which have been found in remote African Pygmy populations. 8,9 Indeed, the major European community-acquired PVL-positive methicillin-resistant S. aureus (ST80 CA-MRSA) most likely originated from Sub-Saharan Africa, as revealed by whole genome sequencing analyses. 10 In conclusion, the study by Rosenthal et al and our report point towards the significance of migration in the spread of certain pathogens such as S. aureus.…”