Michael R. Mulvey

Methicillin-resistant Staphylococcus aureus in Canadian aboriginal people.

We describe 279 hospitalized Canadian aboriginals in whom methicillin-resistant Staphylococcus aureus (MRSA) was detected. They were identified in 38 Canadian hospitals from 1995 through 2002. Compared with nonaboriginals, aboriginals were more likely to be younger than 18 years of age (OR, 1.8; P<.0001), to have had an MRSA infection (OR, 3.8; P<.0001), and to have had MRSA isolated from specimens of skin or soft tissue (OR, 4.1; P=.016). The clinical features of MRSA infection in aboriginals are distinct from those in the general patient population with MRSA infection in Canadian hospitals, and the genetic background of MRSA isolates from aboriginals also varies from that of strains from the non-aboriginal population.

Genotypic investigation of Clostridium difficile in Prince Edward Island.

Clostridium difficile is an important cause of disease in Canada; however, little information is available about the disease in the Maritime provinces. The objective of the present study was to characterize C difficile isolates obtained from people hospitalized with C difficile infection in Prince Edward Island. One hundred twenty-six C difficile ELISA toxin-positive stool samples were obtained and cultured using an enrichment protocol. C difficile was isolated from 105 of 126 (83%) samples. Twenty-two different ribotypes were identified. The most common ribotype, ribotype W, was a North American pulsotype 2 (NAP2), toxinotype 0 strain, which represented 18% of isolates. The next most common ribotype was a NAP1, toxinotype III strain, which accounted for 11% of isolates. Ribotype 027/NAP1 only accounted for five (4.7%) isolates. Forty-five per cent of isolates possessed genes encoding production of binary toxin. Three different ribotypes, all NAP1, toxinotype III strains, had a frameshift mutation in the tcdC gene (Delta117), while one isolate (ribotype 078, NAP4, toxinotype V) had a truncating mutation (C184T) in the tcdC gene.