Tips for future prevention

As mould feeds, it produces enzymes which causes a chemical reaction and this can lead to staining. If heavy staining occurs, it is advisable to use a stain block paint and/or an anti-mould paint when redecorating.

Always remember to keep your property and belongings free of dust as much as possible, so any mould does not have sustenance, and as clean and dry as possible. The worst possible combination is dust landing on moisture, so if you can prevent that combination you'll be a long way towards preventing mould occurring.