Optimizing Mastitis Identification and Treatment

Determination of the microbial composition in human milk from mothers without mastitis by MALDTI-TOF and Illumina sequencing

In order to investigate if there is a particular microbial composition of the human milk that leads to mastitis, the microbial composition in human milk from mothers without mastitis will be assessed. The investigators will collect milk samples from all enrolled mothers at day 6-7 after birth. Milk samples will be stored at -20 until further processing. Mothers who develop mastitis will be further sampled as described in outcome 2. Samples will be analyzed using culture dependent and culture independent methods. Following culturing of the milk samples, colonies will be analysed by Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) to identify bacterial species. DNA will be isolated from the same milk sample.16S rRNA amplicon sequencing of DNA from milk samples will be performed using the Illumina technology, in order to get an overview of the total bacterial composition.

Determination of the microbial composition in human milk from mothers at onset of mastitis by MALDTI-TOF and Illumina sequencing

The investigators will investigate if the microbial composition in human milk changes at onset of mastitis. By analysing possible changes in microbial composition the investigators will assess if the mastitis symptoms are caused by microorganisms, or if the symptoms of mastitis are inflammatory. Milk samples will be collected by the mother at onset of mastitis, 24 hours after onset of symptoms and after resolution of symptoms. If the mastitis episode is treated with antibiotics, a new sample will be taken 24 hours after cessation of antibiotic treatment. Milk samples will be stored at -20 until further processing. Samples will be analyzed using culture dependent, and culture independent methods. Following culturing of the samples, colonies will be analysed by MALDI-TOF to identify bacterial species. 16S rRNA amplicon sequencing of DNA from milk samples will be performed using the Illumina technology, in order to get an overview of the total bacterial composition.

Assessment of the microbial composition on nipples of mothers without mastitis

It is no agreement on if mastitis causing bacteria originate from the breast nipple, or if they are part of the milk microbiome. We will sample the breast nipples in order to investigate if microorganisms colonizing the breast skin enter the mammary glands, and potentially cause mastitis. A skin swab of the nipple (both breasts) will be taken at day 6-7 after birth. Following culturing of the swab, bacterial colonies will be analysed by MALDI-TOF to identify bacterial species. The skin swabs will be collected at the same timepoints as collection of milk samples.

Assessment of the microbial composition on nipples of mothers with mastitis

It is no agreement on if mastitis causing bacteria originate from breast nipple, or if they are part of the milk microbiome. We will sample the breast nipples in order to investigate if microorganisms colonizing the breast skin enter the mammary glands, and potentially cause mastitis. When the mother experiences symptoms of mastitis the mother will collect a skin swab sample. Following culturing of the swab, bacterial colonies will be analysed by MALDI-TOF to identify bacterial species. The skin swabs will be collected at the same timepoints as collection of milk samples.The microbial composition on nipples of mothers with mastitis will also be compared to the nipple microflora of mothers without mastitis in order to see if there is a correlation between particular skin colonizing bacteria that cause mastitis.