Many Arctic biomes, which are populated with abundant and diverse microbial life, are under threat: climate change and warming temperatures have raised concerns about diversity loss and possible emergence of pathogenic microorganisms. At present, there is little information on the occurrence of Arctic virulence-associated phenotypes. In this study we worked with 118 strains of bacteria (from 10 sampling sites in the Arctic region, located in Greenland and the Svalbard Archipelago) isolated using R2A medium. These strains belong to 4 phyla and represent 36 different bacterial genera. Phenotypic resistance to 8 clinically important antimicrobials (ampicillin, chloramphenicol, ciprofloxacin, cefotaxime, erythromycin, imipenem, kanamycin, and tetracycline) and thermotolerance range were determined. In addition, a screening of all isolates on blood agar media and erythrocytes suspension of bovine and sheep erythrocytes for virulence-linked hemolytic activity was performed. Although antimicrobial resistance profiles varied among the isolates, they were consistent within bacterial families and genera. Interestingly, a high number of isolates (83/104) were resistant to the tested concentration of imipenem (4 mg/L). In addition, one third of the isolates showed hemolytic activity on blood agar, however, in only 5% of the isolates hemolytic activity was also observed in the cell extracts when added to erythrocyte suspensions for 60 min. The observed microbial phenotypes contribute to our understanding of the presence of virulence-associated factors in the Arctic environments, while highlighting the potential risks associated with changes in the polar areas in the light of climate change.

Infections with pathogenic Escherichia coli can lead to different animal- and human-associated diseases. E. coli infections are common in intensive poultry farming, and important economic losses can be expected during infections with avian pathogenic E. coli (APEC) strains followed by colibacillosis. Loop-mediated isothermal amplification (LAMP) assays were developed for rapid detection of 3 APEC-associated virulence genes: sitA, traT, and ompT. All 3 LAMP assays are shown to be specific, repeatable, and reproducible. High sensitivities of the assays are shown, where as few as 1,000 bacterial cells/mL can be detected in different matrices. On-site applicability of this LAMP method is demonstrated through testing of different sample types, from animal swabs and tissues, and from environmental samples collected from 6 commercial poultry farms. All 3 virulence genes were detected at high rates (above 85%) in samples from layer and broiler chickens with clinical signs and, interestingly, high prevalence of those genes was detected also in samples collected from clinically healthy broiler flock (above 75%) while lower prevalence was observed in remaining 3 clinically healthy chicken flocks (less than 75%). Importantly, these virulence genes were detected in almost all of the air samples from 11 randomly selected poultry houses, indicating air as an important route of E. coli spread. Three LAMP assays that target APEC-associated virulence genes are shown to be sensitive and robust and are therefore applicable for rapid on-site testing of various sample types, from animal swabs to air. This on-site LAMP testing protocol offers rapid diagnostics, with results obtained in <35 min, and it can be applied to other important microorganisms to allow the required prompt measures to be taken.