Etiología y epidemiología de las mastitis humanas

Abstract

Infectious mastitis is a common condition during lactation and constitutes one of the main causes of undesired weaning. This condition should be considered as a relevant Public Health issue, since it deprives the mother-infant pair from the wide range of health benefits that breastfeeding provides. Nevertheless, human mastitis remains to date widely underestimated because human milk cultures are not routinely performed and only acute mastitis cases with local and systemic symptoms are usually reported. It has been addressed that human mastitis is characterized by a dysbiosis process in the mammary gland, leading to an overgrowth of certain bacterial species present in human milk. However, the etiology of this condition has been scarcely investigated, and the role of some bacterial pathogens remains unclear. In this study, the microbiological analysis of 1,849 milk samples obtained from women with infectious mastitis has revealed that genus Staphylococcus was the most frequently isolated bacterial group. Staphylococcus epidermidis was the most common species (91.56% of the samples) while Staphylococcus aureus was detected in 29.74% of them. Streptococci and corynebacteria constituted the second (70.20%) and third (16.60%) most prevalent bacterial groups, respectively, in this study. These results show that coagulase-negative staphylococci, viridans group streptococci (VGS) and corynebacteria, usually dismissed as contaminant bacteria, may play an important role as etiological agents of mastitis. Therefore, microbiological analysis of human milk, identifying the disease-causing pathogens at the species level, should be the only method for determining the etiology of mastitis and establishing an efficient treatment of this condition ...