The Role of Staphylococcus aureus in Mastitis

Abstract

Background: Breastfeeding women are at risk of developing mastitis during the lactation period. Staphylococcus aureus has emerged as the community-acquired pathogen responsible for virulence (methicillin resistance and Panton-Valentine leukocidin toxin producing). Research aim: The aim was to compare the microorganisms responsible for mastitis and breast abscesses during breastfeeding. Methods: This observational study was conducted with a sample of women ( N = 60) admitted to our hospital between 2016 and 2018. Participants affected by mastitis and breast abscess were studied and cared for by a multidisciplinary working group. A diagnostic breast ultrasound identified the pathology. Results: Twenty-six participants (43.3%) were affected by mastitis and 34 (56.7%) by breast abscess. The most common microorganism identified was Staphylococcus aureus ( S. aureus; mastitis, n = 13; abscesses, n = 24). Methicillin resistance was identified in 21 (44.7%) S. aureus strains: 17 (80.9%) cases of abscess and four (19.1%) cases of mastitis. The median number of months of breastfeeding was smaller in the methicillin-resistant S. aureus (MRSA) cases (median = 3, range = 1–20 months) than in the methicillin-sensitive S. aureus (MSSA) cases (median = 6.5, range = 3–21 months). The Panton-Valentine leukocidin toxin gene was detected in 12 (25.5%) cases (MRSA, n = 8, 66.7%; MSSA, n = 4, 33.3%). Hospitalization was required more frequently in MRSA ( n = 8, 38%; five Panton-Valentine leukocidin positive) than in MSSA cases ( n = 5, 19%; one Panton-Valentine leukocidin positive). Four women out of the eight MRSA cases (50%) that were Panton-Valentine leukocidin positive stopped breastfeeding during mammary pathologies, three (37.5%) participants continued breastfeeding until the follow-up recall, and one case was lost at follow-up. Conclusion: Clinical severity was probably complicated by the presence of the Panton-Valentine leukocidin toxin, which required hospitalization more frequently.

Clinical characteristics of lactational breast abscess caused by methicillin-resistant Staphylococcus aureus: hospital-based study in China

“…In recent years, the detection rate of MRSA in lactating patients has gradually increased [ 2 , 3 , 5 ]. Whether the patients with MRSA-infected breast abscesses are more serious than those infected with MSSA or whether MRSA increases the difficulty of breast abscess treatment remains unclear.…”

“…Staphylococcus aureus is the most common pathogenic bacteria among breast abscesses during lactation. It is a gram-positive bacteria with strong pathogenicity and can cause skin, soft-tissue, bone, joint, and systemic organ infections [ 2 – 5 ]. In 1961, the world’s first case of methicillin-resistant Staphylococcus aureus (MRSA) was isolated by Jevons [ 6 ].…”

“…The infection and isolation rates of MRSA have been increasing worldwide, and it has become one of the primary pathogens of nosocomial and community-acquired infections [ 7 ]. In recent years, the detection rate of MRSA in the breast milk and pus of lactating patients has gradually increased [ 2 , 3 , 5 ]. MRSA is characterized by high-level drug resistance and a complex drug resistance mechanism, which can increase infection-caused mortality, prolong the length of the hospital stay and increase medical expenses [ 8 ].…”

Identifying the cause of breast and nipple pain during lactation

“…One in five breastfeeding women are diagnosed with mastitis,12 and the usual organism is S aureus 13. Signs and symptoms are similar to a blocked duct but women usually also have systemic illness (figs 6, 7).…”

The Association between Infant Colic and the Multi-Omic Composition of Human Milk

“…Indeed, strains of Staphylococcus epidermidis in human milk display marked similarity to those found in the stool of breastfeeding infants, suggesting the potential for mother–infant transfer [ 56 ]. Although not all strains of Staphylococcus are pathogenic, Staphylococcus aureus , in particular, has been associated with pathologic conditions in both the mammary glands and the infant gut [ 57 , 58 ].…”