COMMON HOUSE SPIDERS can carry harmful bacteria that is susceptible to infect people and can be transmitted through bites, new research by Irish-based scientists has found.

Research carried out by scientists at NUI Galway has also found that the Noble False Widow spider also carries harmful strains of bacteria that are resistant to common antibiotic treatments.

The study was published in the international journal Scientific Reports, and explains a range of symptoms experienced by victims bitten by the invasive Noble False Widow spider in Ireland and Britain over the past decade.

It shows that spiders carry harmful bacteria and that their germs can be transmitted when a spider uses its fangs to bite.

Rare “skin-eating” conditions after seemingly harmless European and North American spider bites had previously been thought to be the result of secondary infections caused by the victim scratching and probing the bite site with contaminated fingers.

Dr John Dunbar of the Ryan Institute’s Venom System Lab in NUI Galway explained that only around ten species of spiders common in North-western Europe have fangs strong enough to pierce human skin and deliver venom

However, he said only one of these – the Noble False Widow spider – is considered of medical importance.

“Most of the time, a spider bite results in some redness and pain,” Dunbar said.

“In some cases, however, victims seem to develop long lasting infections for which strong antibiotic treatment – and sometimes a hospital stay – are necessary.

“It is this increasing range expansion and massive rise in dense populations of false widow spiders around urbanised areas across Ireland and Britain that has seen a rise in bites with some severe envenomation symptoms but also infections, which in some cases proved even difficult to treat with antibiotics.”