New strain of MRSA discovered in patients in Ireland

June 3, 2011 – DUBLIN – A distinctly new type of methicillin resistant Staphylococcus aureus (MRSA) that is not detected by traditional genetic screening methods has been discovered in patients in Irish hospitals according to research to be published in the journal Antimicrobial Agents and Chemotherapy. These findings provide significant insights into how new MRSA strains emerge and highlight the potential for the transmission of infectious agents from animals to humans. MRSA is a significant cause of hospital- and community-acquired infection worldwide. MRSA strains are characterized by the presence of a mobile DNA cassette (known as SCCmec) encoding genes that confer resistance to beta-lactam antibiotics including methicillin and recombinase genes that allow the cassette to transfer into methicillin-susceptible S. aureus (MSSA). Scientists at the University of Dublin, the Irish National MRSA Reference Laboratory and the University of Dresden and Alere Technologies in Germany identified the new MRSA strain using high throughput DNA microarray screening. Complete genome sequencing revealed that this strain is distinctly different to previously described MRSA. It carries a new type of SCCmec encoding highly divergent genes that are very different to any described previously in MRSA or in any other organism. Consequently the new strain is not detected as MRSA by routine conventional and real time DNA-based polymerase chain reaction (PCR) assays commonly used to screen patients for MRSA. The MRSA strain was found to belong to the genetic lineage clonal complex 130 (CC130), which has previously only been associated with MSSA from cows and other animals, but not humans, strongly suggesting that the new MRSA originated in animals. –Medical Express

Scotland: Mutant strain of MRSA emerges in cow’s milk

E.coli update: BERLIN (Reuters) – Germany’s disease control center reported on Friday 199 new cases in the last two days of a rare, deadly strain of E. coli that has so far caused up to 17 deaths. The Robert Koch Institute said in a statement there had been 149 cases of E.coli infection and 50 of the hemolytic uremic syndrome (HUS) caused by E.coli. The latest numbers bring the total number of cases since May 1 to 1,733, it said. –Yahoo News