Cockroaches could help combat MRSA and E.coli - Cockroaches are insects, which are found almost every where around the world. There are about 4,500 species of cockroach, of which 30 species are associated with human habitations and about four species are well known as pests. Scientists have discovered that cockroaches contain powerful antibiotic molecules in their brains that could be used to develop new treatments against MRSA and E-coli.