Changes in the skin microbiome have been shown to promote cutaneous inflammation. The skin microbiome of patients with chronic plaque type psoriasis was analysed before and after treatment with narrowband ultraviolet B (UVB). Swab samples of the microbiome were taken from lesional and non-lesional skin of 26 patients. Microbiotas were characterized by sequencing 16S rRNA bacterial genes on the Illumina MiSeq platform. Lesional skin microbiome diversity correlated with psoriasis severity (measured with the Psoriasis Area and Severity Index; PASI). There was a significantly lower abundance of the phylum Firmicutes and the genus Staphylococcus in lesional skin compared with non-lesional skin before UVB treatment. Responders (> 75% target Psoriasis Severity Index (PSI) improvement) had significantly lower abundance of the phyla Firmicutes in lesional and non-lesional skin and lower abundance of the genera Staphylococcus, Finegoldia, Anaerococcus, Peptoniphilus, Gardnerella, Prevotella and Clostridium in lesional skin after UVB treatment. Pseudomonas significantly decreased in lesional and non-lesional skin of treatment responders. These results suggest that skin microbiome alterations after UVB treatment could be related to treatment and treatment response.

No abstract

Norovirus is now recognized as the leading cause of nonbacterial acute gastroenteritis in adults, causing numerous outbreaks worldwide. We have developed two novel light-upon-extension (LUX) real-time PCR assays for detection and quantification of norovirus genogroups I and II. The LUX system uses a fluorophore attached to one primer having a self-quenching hairpin structure, making it cost-effective and specific. The assays were evaluated against clinical stool specimens (n ‫؍‬ 103) from Sweden and Nicaragua and compared to established methods. The norovirus assay detected more positive stool specimens (47/103) than conventional PCR (39/103) and corresponded to a TaqMan real-time PCR, with the exception of one specimen. Furthermore, the assays correctly identified all (n ‫؍‬ 11) coded control specimens in a reference panel containing various genogroups and genotypes. Both LUX real-time PCR assays had a wide dynamic range, detecting from <10 1 to 10 7 genes per reaction, resulting in a theoretical lower limit of <ϳ20 000 viruses per gram of stool. No cross-reactivity was noticed with specimens containing other enteric viruses, and by using melting curve analysis we could differentiate between norovirus genogroups I and II.

No abstract

The distribution limit of Ixodes ricinus ticks in northwestern Europe (Brønnøy, Norway, 1° south of the Arctic Circle), has been known since the 1930s. To reconfirm this finding and extend studies in the areas adjacent to the Arctic Circle (66°33' N), ticks were collected from dogs and cats in 8 districts in northern Norway from 64°56' N to 68°48' N. We detected 549 I. ricinus, 244 (44%) of them in Brønnøy district, and 305 (range 6-87 ticks) in 7 districts in the northern part of the study area. The prevalence of Borrelia in these ticks was determined by real-time PCR. In the Brønnøy district (65°28' N, 12°12' E), 29% of the I. ricinus were Borrelia spp.-positive, and the species B. afzelii was nearly twice as prevalent as B. garinii and/or B. valaisiana. In the study area north of Brønnøy district, only 12 (4%) of the collected ticks contained Borrelia spp. In conclusion, tick occurrence and Borrelia prevalence are high in the Brønnøy district. In contrast, I. ricinus occurrence and Borrelia prevalence are low further north across the Arctic Circle in Norway.

Several studies indicate that chemokines play important roles in colorectal mucosal immunity by recruiting leukocytes into and out of the lamina propria adjacent to the epithelium. The chemokine CXCL5 which is expressed by epithelial cells within colorectal mucosa is a chemoattractant for neutrophils and has been implicated in Crohn's disease and ulcerative colitis. In addition, CXCL5 is one chemokine which promote angiogenesis related to cancer. The objective of this study was to determine by ELISA assay whether CXCL5 protein level is altered in colorectal cancer (CRC) tissues (n=80) compared with paired normal mucosa. Furthermore, the plasma CXCL5 levels from CRC patients (n=62) compared with controls (n=71) were also examined. Using a TaqMan system we screened for -156G¨C and +398G¨A CXCL5 gene variants in CRC patients (n=228) and a control group (n=231) to assess the role of CXCL5 genotype in CRC. The analyses showed that CXCL5 protein level in colorectal tumours was significantly (P<0.0001) higher than in normal tissue and was lower in plasma in CRC patients compared with controls (P=0.026). Immunohistochemistry revealed CXCL5 immunoreactivity mainly in epithelial cells of the colorectal carcinoma and in normal epithelial cells. Furthermore, patients who were -156C carriers had higher CXCL5 protein concentration compared with -156G carriers in normal tissue (P=0.027) and CXCL5 protein levels in cancerous tissue tended to be higher for the patient -156C carriers (P=0.059). To our knowledge this is the first report on the influence of CXCL5 gene variants and their relation to expression of CXCL5 protein in human CRC.

The up-regulated eotaxin-1 protein expression in cancer tissue may reflect an eotaxin-1 mediated angiogenesis and/or a recruitment of leukocytes with potential antitumourigenic role. We noticed a dominance of the G allele in rectal cancer patients compared with colon cancer patients that was independent of eotaxin-1 expression.

Norovirus contamination of drinking water sources is an important cause of waterborne disease outbreaks. Knowledge on pathogen concentrations in source water is needed to assess the ability of a drinking water treatment plant (DWTP) to provide safe drinking water. However, pathogen enumeration in source water samples is often not sufficient to describe the source water quality. In this study, the norovirus concentrations were characterised at the contamination source, i.e. in sewage discharges. Then, the transport of norovirus within the water source (the river Göta älv in Sweden) under different loading conditions was simulated using a hydrodynamic model. Based on the estimated concentrations in source water, the required reduction of norovirus at the DWTP was calculated using quantitative microbial risk assessment (QMRA). The required reduction was compared with the estimated treatment performance at the DWTP. The average estimated concentration in source water varied between 4.8×10(2) and 7.5×10(3) genome equivalents L(-1); and the average required reduction by treatment was between 7.6 and 8.8 Log10. The treatment performance at the DWTP was estimated to be adequate to deal with all tested loading conditions, but was heavily dependent on chlorine disinfection, with the risk of poor reduction by conventional treatment and slow sand filtration. To our knowledge, this is the first article to employ discharge-based QMRA, combined with hydrodynamic modelling, in the context of drinking water.