Neutralization of the Staphylococcus aureus Panton-Valentine leukocidin by African and Caucasian sera

Abstract

Background The prevalence of Staphylococcus aureus isolates carrying the Panton-Valentine leukocidin (PVL) gene is higher in Africa (≈50%) compared to Europe (< 5%). The study aimed to measure anti-PVL-antibodies in Africans and Germans in a multi-center study and to test whether detected antibodies can neutralize the cytotoxic effect of PVL on polymorphonuclear leukocytes (PMNs). Methods Sera from asymptomatic Africans ( n = 22, Nigeria, Gabon) and Caucasians ( n = 22, Germany) were used to quantify antibody titers against PVL and α-hemolysin (in arbitrary units [AU]) by ELISA. PMNs from one African and German donor were exposed to 5 nM recombinant PVL to measure the neutralizing effect of serial dilutions of pooled sera from African and Caucasian participants, or donor sera at 0.625 and 2.5% (v/v). Results Anti-PVL-antibodies were significantly higher in Africans than in Germans (1.9 vs. 0.7 AU, p < 0.0001). The pooled sera from the study participants neutralized the cytotoxic effect of PVL on African and German PMNs in a dose dependent manner. Also, neutralization of PVL on PMNs from the African and German donors had a stronger effect with African sera (half-maximal inhibitory concentration (IC 50 ) = 0.27 and 0.47%, respectively) compared to Caucasian sera (IC 50 = 3.51 and 3.59% respectively). Conclusion Africans have higher levels of neutralizing anti-PVL-antibodies. It remains unclear if or at what level these antibodies protect against PVL-related diseases. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-022-02636-5.

Microbial keratitis in Southern Malawi: a microbiological pilot study

“…50 PVL is associated with poorer clinical outcomes in MK 50 and is known to be high among clinical S. aureus strains in Africa (74% of methicillin-susceptible S. aureus isolates) compared with Europe (0.2%) and the USA (11.5%). [51][52][53][54] Further investigation into the role of virulence factors in MK pathogenesis in Malawi is warranted.…”