Culture independent assessment of human milk microbial community in lactational mastitis

Shriram H Patel,Chaitanya G Joshi,Yati H Vaidya,Anju P Kunjadiya,Reena J Patel,Ramesh J Pandit

doi:10.1038/s41598-017-08451-7

Shriram H Patel, Chaitanya G Joshi + Show 4 more

Open Access

https://doi.org/10.1038/s41598-017-08451-7

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Abstract

Breastfeeding undoubtedly provides important benefits to the mother-infant dyad and should be encouraged. Mastitis, one of the common but major cause of premature weaning among lactating women, is an inflammation of connective tissue within the mammary gland. This study reports the influence of mastitis on human milk microbiota by utilizing 16 S rRNA gene sequencing approach. We sampled and sequenced microbiome from 50 human milk samples, including 16 subacute mastitis (SAM), 16 acute mastitis (AM) and 18 healthy-controls. Compared to controls, SAM and AM microbiota were quite distinct and drastically reduced. Genera including, Aeromonas, Staphylococcus, Ralstonia, Klebsiella, Serratia, Enterococcus and Pseudomonas were significantly enriched in SAM and AM samples, while Acinetobacter, Ruminococcus, Clostridium, Faecalibacterium and Eubacterium were consistently depleted. Further analysis of our samples revealed positive aerotolerant odds ratio, indicating dramatic depletion of obligate anaerobes and enrichment of aerotolerant bacteria during the course of mastitis. In addition, predicted functional metagenomics identified several gene pathways related to bacterial proliferation and colonization (e.g. two-component system, bacterial secretion system and motility proteins) in SAM and AM samples. In conclusion, our study confirmed previous hypothesis that mastitis women have lower microbial diversity, increased abundance of opportunistic pathogens and depletion of commensal obligate anaerobes.

Highlights

Breastfeeding gives a unique opportunity for improving infant health, at the same time, maternal health[1]
We and others have previously demonstrated higher abundance of Staphylococcus aureus and Staphylococcus epidermidis, a species considered as common colonizer of skin and mucosa, together with bacteria belonging to the genus Streptococci, Corynebacterium, Pseudomonas, Klebsiella and Enterococcus form mastitis samples[15, 21,22,23]
We show that women having subacute mastitis (SAM) and acute mastitis (AM) had distinct microbial community profile, reduced microbial diversity and higher abundance of opportunistic pathogens compared to healthy-controls

Summary

Introduction

Breastfeeding gives a unique opportunity for improving infant health, at the same time, maternal health[1]. To the results obtained from culture dependent studies, Staphylococcus (S. aureus in acute and S. epidermidis in subacute mastitis) and Pseudomonas were the predominant genus in subacute and acute mastitis cases. They found that SAM and AM women had decreased microbial diversity and higher sequences related to presumptive etiological agents compared to control[16]. In this context, we first time report influence of SAM and AM on human milk microbiome through amplicon sequencing approach. We show that women having SAM and AM had distinct microbial community profile, reduced microbial diversity and higher abundance of opportunistic pathogens compared to healthy-controls

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Results

Conclusion