Shiga toxin-producing E. coli (STEC) is an important foodborne pathogen causing diarrhea, hemorrhagic colitis and hemolytic-uremic syndrome in humans. STEC is an implicated in the vast majority of outbreaks, widely via consumption of STEC contaminated beef, as important vehicle of transmission of this organism to human. The E. coli O157:H7 serotype is traditionally identified by serological identification of the somatic antigen (O157) and structural flagella (H7). In this study, the bacteria were identified as STEC serotype O157:H7 with three primer pairs that amplified fragments of secD, rfbE and fliC genes in PCR assays. These primer pairs specifically amplified different sizes of target genes: a 244bp region of the E. coli diagnostic marker gene (secD); a 317bp region of the O157 lipopolysacharide (LPS) gene (rfbE); and a 381bp region of the H7 flagellin gene (fliC). The singleplex, duplex and triplex PCR assay developed in this study have a sensitivity limit at 2.8 x 103, 2.8 x 105 and 2.8 x 107 CFU/ml of E. coli O157:H7, respectively. Sensitivity to detect trace amount of E. coli O157:H7 DNA was reduced as the number of primer used was increased for competing to the same DNA template.
Telosticta fugispinosa sp. nov. (holotype male, from Borneo, Sabah, West Coast division, Crocker Range National Park, Inobong, Kimamabang waterfall stream system, 21 ix 2012, deposited in RMNH) is described from Kinabalu National Park and Crocker Range National Park in Sabah, Malaysian Borneo. It is distinguished from all other species of Telosticta by the form of the male anal appendages.
Tropical mountains are hot spots of biodiversity and endemism, but the evolutionary origins of their unique biotas are poorly understood. In varying degrees, local and regional extinction, long-distance colonization, and local recruitment may all contribute to the exceptional character of these communities. Also, it is debated whether mountain endemics mostly originate from local lowland taxa, or from lineages that reach the mountain by long-range dispersal from cool localities elsewhere. Here we investigate the evolutionary routes to endemism by sampling an entire tropical mountain biota on the 4,095-metre-high Mount Kinabalu in Sabah, East Malaysia. We discover that most of its unique biodiversity is younger than the mountain itself (6 million years), and comprises a mix of immigrant pre-adapted lineages and descendants from local lowland ancestors, although substantial shifts from lower to higher vegetation zones in this latter group were rare. These insights could improve forecasts of the likelihood of extinction and 'evolutionary rescue' in montane biodiversity hot spots under climate change scenarios.