Vancomycin and nisin A are effective against biofilms of multi-drug resistant Staphylococcus aureus isolates from human milk.

Autor: Angelopoulou A; School of Microbiology, University College Cork, Cork, Ireland.; APC Microbiome Ireland, University College Cork, Cork, Ireland., Field D; School of Microbiology, University College Cork, Cork, Ireland.; APC Microbiome Ireland, University College Cork, Cork, Ireland., Pérez-Ibarreche M; APC Microbiome Ireland, University College Cork, Cork, Ireland., Warda AK; APC Microbiome Ireland, University College Cork, Cork, Ireland., Hill C; School of Microbiology, University College Cork, Cork, Ireland.; APC Microbiome Ireland, University College Cork, Cork, Ireland., Ross RP; School of Microbiology, University College Cork, Cork, Ireland.; APC Microbiome Ireland, University College Cork, Cork, Ireland.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2020 May 29; Vol. 15 (5), pp. e0233284. Date of Electronic Publication: 2020 May 29 (Print Publication: 2020).
DOI: 10.1371/journal.pone.0233284
Abstrakt: Human milk provides complete nutrition for infants and at the same time promotes the growth of specific bacteria in the infant gastrointestinal tract. Breastfeeding can often be discontinued due to mastitis which is an inflammation of the breast tissue. We isolated 18 Staphylococcus aureus strains from milk donated by healthy (n = 6), subclinical (n = 6), and mastitic (n = 6) mothers, two strains of which were VISA (Vancomycin Intermediate S. aureus). All tested strains (n = 12) were able to form biofilms. We then examined the impact of nisin A and vancomycin alone and in combination on biofilm formation and eradication of selected strains (n = 8). We observed strain-specific responses, with the combinatorial treatment at 1/4X MIC (for both singularly) significantly inhibiting biofilm formation for seven out of eight strains when compared with nisin A or vancomycin alone. None of the selected treatments were able to eradicate pre-formed biofilms. Finally, we selected two strains, namely a VISA (APC3814H) and a strong biofilm former (APC3912CM) and used confocal microscopy to evaluate the effects of the antimicrobial agents at 1X MIC on biofilm inhibition and eradication. All treatments inhibited biofilm formation of APC3814H but were ineffective in eradicating a pre-formed biofilm. Single treatments at 1X MIC against APC3912CM cells did not prevent biofilm formation whereas combination treatment caused increased death of APC3912CM cells. Finally, the combination treatment reduced the thickness of the pre-formed APC3912CM biofilm as compared with the single treatments.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Databáze: MEDLINE
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