Hairballed bacteria stick to skin, triggering infection in preemies
Skin, the human body's largest organ, is an effective barrier against bacteria. But the extremely delicate skin of a premature baby can be the ultimate breeding ground for organisms, triggering certain infectious diseases. A Swedish team of researchers, writing in the journal of Pediatric Research, has discovered that a specific kind of staphylococcus can attach itself to the skin by using its tufted, self-adhesive hairballs and cause infection. The researchers from the Karolinska Institute explained that staphylococcus establishes itself on the child's skin and mucous membranes directly after birth. In general, no problems emerge between the bacteria and the host organism. However, troubles can occur for premature babies or sick adults, they said, adding that the bacteria can cause sepsis (blood poisoning). The researchers discovered that the bacteria's hairballs help them stick to the host's cells and that is when the infections kick in. 'Coagulase-negative staphylococci (CoNS) are major skin commensals in humans. Within the first few hours of life colonisation occurs and, by one day of age, 84% of all healthy neonates have their skin colonised,' the authors wrote in the paper. 'Among the CoNS, particular attention has been focused on Staphylococcus epidermidis (S. epidermidis) since it is the most common species responsible for infection, causing significant morbidity, mortality and incurring healthcare costs worldwide.' Based on the latest data, CoNS are considered as being some of the most significant pathogens that cause late-onset sepsis in infants with very low birth weight (LBW). CoNS are also connected with the origin and development of erythema toxicum, an immunological skin reaction commonly found in otherwise healthy newborns. The team discovered that the human cathelicidin peptide LL37, an antimicrobial substance, is capable of inhibiting bacterial growth and probably contributes to the stability of bacterial flora and curbs their uncontrolled proliferation. 'Here we identify, by negative staining transmission electron microscopy, two different types of pilus-like structures commonly expressed on S. epidermidis isolated from newborn infants,' they wrote. 'We also show that the cathelicidin antimicrobial peptide LL37, constitutively expressed in the skin barrier of the newborn, significantly inhibited growth of S. epidermidis indicating its importance for the ecological stability of the skin microbiota [the microorganisms that typically inhabit a bodily organ or part].' For her part, Professor Giovanna Marchini from the Karolinska Institute and senior physician at the Astrid Lindgren Children's Hospital neonatal section said: 'We wanted to conduct this research not only to learn more about the pathogenic potential of the bacteria, but also to understand how the child can protect itself from attack by, for instance, enhancing the body's own defences.' As time has passed, the ability of humans to co-exist with various microbes has evolved. Professor Marchini explained that bacteria are needed by the human body to ensure the development of an effective immune defence system. 'It's thought that the past decades' hunt for disease-causing bacteria means that we now live too cleanly, which has contributed to the sharp rise in allergies and other 'luxury diseases',' said Professor Marchini. 'Other than wanting to prevent infection in babies, we also think it's an exciting challenge to understand the conceivable health aspects of these tiny, round and tufted skin dwellers.' The researchers noted further studies are needed to clarify the molecular mechanisms of host-microbe interactions in order to maintain a mutually beneficial homeostatic relationship and to protect people against overt disease.
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