Vibrio vulnificus

Vibrio vulnificus er en bakterie som trives i saltvann over 20 grader og som kan gi sykdom hos personer med sår eller nedsatt immunforsvar (såkalt opportunistisk infeksjon). Alvorlige sykdom forekommer oftest nær Taiwan, Sør-Korea, Japan og i Mexicogolfen. I senere år er det rapportert flere tilfeller med alvorlige infeksjon med Vibrio vulnificus hos personer som har badet i nordiske kystområder. I løpet av den varme sommeren 2018 var det sju personer som ble alvorlig syke med denne infeksjonen i Norge. Det ble også registrert flere mindre alvorlige tilfeller. Vibrio vulnificus er bakterien som forårsaker de fleste sjømat-assosierte dødsfall i verden. Bakterien har evnen til å overleve i det krevende miljøet i mage-tarm-systemet, og kan derfor forårsake infeksjon her. Bakterien kan også trenge inn i åpne sår og dermed føre til hudinfeksjon. Trenger bakterien dypere ned i det underliggende vevet vil den kunne komme over i blodbanen og medføre sepsis (blodforgiftning). Dette er en tilstand med høy dødelighet, også kalt «badsårsfeber»

Candida auris

Candida auris (C. auris) er en gjærsopp som kan forårsake alvorlige infeksjoner hos mennesker. Infeksjoner med Candida auris forekommer i hovedsak i helseinstitusjoner og rammer som regel alvorlig syke pasienter. I tillegg er behandling vanskelig fordi soppen ofte er resistent/motstandsdyktig mot de vanligste medikamentene som brukes ved Candida-infeksjon

Host and microbe determinants that may influence the success of S. aureus colonization

Staphylococcus aureus may cause serious skin and soft tissue infections, deep abscesses, endocarditis, osteomyelitis, pneumonia, and sepsis. S. aureus persistently colonizes 25–30% of the adult human population, and S. aureus carriers have an increased risk for infections caused by the bacterium. The major site of colonization is the nose, i.e., the vestibulum nasi, which is covered with ordinary skin and hair follicles. Several host and microbe determinants are assumed to be associated with colonization. These include the presence and expression level of bacterial adhesins, which can adhere to various proteins in the extracellular matrix or on the cellular surface of human skin. The host expresses several antimicrobial peptides and lipids. The level of β-defensin 3, free sphingosine, and cis-6-hexadecenoic acid are found to be associated with nasal carriage of S. aureus. Other host factors are certain polymorphisms in Toll-like receptor 2, mannose-binding lectin, C-reactive protein, glucocorticoid-, and vitamin D receptor. Additional putative determinants for carriage include genetic variation and expression of microbial surface components recognizing adhesive matrix molecules and their interaction partners, as well as variation among humans in the ability of recognizing and responding appropriately to the bacteria. Moreover, the available microflora may influence the success of S. aureus colonization. In conclusion, colonization is a complex interplay between the bacteria and its host. Several bacterial and host factors are involved, and an increased molecular understanding of these are needed

Comunicazione italiana nel mondo: interviste a distanza. Prove d'Europa a Radio Colonia

L’Europa è di casa a Radio Colonia, l’emittente italiana del WDR, Westdeutscher Rundfunk, l’ente radiotelevisivo pubblico del Land Nord Reno-Westfalia, che il primo dicembre scorso ha celebrato il mezzo secolo di vita. Il suo direttore, Tommaso Pedicini, ricorda i motivi che portarono alla nascita della Radio, nel 1961, in un periodo in cui esplodeva il fenomeno dell’emigrazione italiana in Germania ed i Gastarbeiter (“lavoratori ospiti”) italiani avevano bisogno di una voce amica. Da allora molti sono stati i cambiamenti, ma Radio Colonia è rimasta la finestra italiana nel panorama radiofonico tedesco, impegnata in particolare, dopo l’avvio nel 1999 della Funkhaus Europa, a coltivare i temi del plurilinguismo e dell’integrazione degli immigrati

Circulating sex-steroids and Staphylococcus aureus nasal carriage in a general female population

Objective: Staphylococcus aureus is a major human pathogen, and nasal carriers have an increased risk for infection and disease. The exploration of host determinants for nasal carriage is relevant to decrease infection burden. Former studies demonstrate lower carriage prevalence in women and among users of progestin-only contraceptives. The aim of this study was to investigate the possible associations between circulating sex-steroid hormones and nasal carriage of Staphylococcus aureus in a general population. Methods: In the population-based sixth Tromsø study (2007–2008) nurses collected nasal swab samples from 724 women aged 30–87 not using any exogenous hormones, and 700 of the women had a repeated nasal swab taken (median interval 28 days). We analysed a panel of serum sex-steroids by liquid chromatography tandem mass spectrometry, and collected information about lifestyle, health and anthropometric measures. Multivariable logistic regression was used to study the association between circulating sex-steroids and Staphylococcus aureus carriage (one swab) and persistent carriage (two swabs), while adjusting for potential confounding factors. Women in luteal phase were excluded in the analysis of androgens. Results: Staphylococcus aureus persistent nasal carriage prevalence was 22%. One standard deviation increase in testosterone and bioavailable testosterone was associated with lower odds of persistent nasal carriage, (OR = 0.57; 95% CI = 0.35–0.92 and OR = 0.52, 95% CI = 0.30–0.92) respectively. Analysis stratified by menopause gave similar findings. Persistent carriers had lower average levels of androstenedione and DHEA, however, not statistically significant. Conclusion: This large population-based study supports that women with lower levels of circulating testosterone may have increased probability of Staphylococcus aureus persistent carriage

Local Variants of Staphylococcal Cassette Chromosome mec in Sporadic Methicillin-Resistant Staphylococcus aureus and Methicillin-Resistant Coagulase-Negative Staphylococci: Evidence of Horizontal Gene Transfer?

The mecA gene in Staphylococcus aureus is located on the genetic element staphylococcal cassette chromosome (SCC). Different SCCmecs have been classified according to their putative recombinase genes (ccrA and ccrB) and overall genetic composition. Clinical isolates of coagulase-negative staphylococci (CoNS; n = 39) and S. aureus (n = 20) from Norway, India, Italy, Finland, the United States, and the United Kingdom were analyzed by pulsed-field gel electrophoresis, which showed that most isolates were genetically unrelated. Cluster analyses of 16S rRNA gene and pta sequences confirmed the traditional biochemical species identification. The mecI, mecR1, mecA, and ccrAB genes were detected by PCRs, identifying 19 out of 20 S. aureus and 17 out of 39 CoNS isolates as carriers of one of the three published ccrAB pairs. New variants of SCCmec were identified, as well as CoNS isolates containing ccrAB genes without the mec locus. ccrAB and mec PCRs were verified by hybridization. Sequence alignments of ccrAB genes showed a high level of diversity between the ccrAB alleles from different isolates, i.e., 94 to 100% and 95 to 100% homology for ccrAB1 and ccrAB2, respectively. All of the ccrAB3 genes identified were identical. Genetically unique and sporadic methicillin-resistant S. aureus (MRSA) contained local variants of ccrAB gene pairs identical to those found in MR-CoNS but different from those in MRSA from other regions. Allelic variants of ccrAB in isolates from the same geographic region showed sequence conservation independent of species. The species-independent sequence conservation found suggests that there is a closer genetic relationship between ccrAB2 in Norwegian staphylococci than between ccrAB2 sequences in international MRSA and Norwegian MRSA. This might indicate that different staphylococcal species acquire these genes locally by horizontal gene transfer

Genetic variability in the sdrD gene in Staphylococcus aureus from healthy nasal carriers

Background: Staphylococcus aureus cell wall anchored Serine Aspartate repeat containing protein D (sdrD) is a member of the microbial surface component recognising adhesive matrix molecules (MSCRAMMs). It is involved in the bacterial adhesion and virulence. However the extent of genetic variation in S. aureus sdrD gene within isolates from healthy carriers are not known. The aim of this study was to evaluate allelic variation of the sdrDgene among S. aureus from healthy nasal carriers. Results: The sdrD A region from 48 S. aureus isolates from healthy carriers were analysed and classified into seven variants. Variations in the sdrD A region were concentrated in the N2 and N3 subdomains. Sequence analysis of the entire sdrD gene of representative isolates revealed variations in the SD repeat and the EF motifs of the B repeat. In silico structural modelling indicates that there are no differences in the sdrD structure of the 7 variants. Variable amino acid residues mapped onto the 3D structure revealed that the variations are surface located, exist within the groove between the N2-N3 subdomains and distributed mainly on the N3 subdomain. Comparison of adhesion to keratinocytes in an in vitro cell adhesion assay, using NCTC 8325–4∆sdrD strains expressing the various sdrD gene variants, indicated a significant difference between only two complements while others showed no major difference in their adhesion. Conclusions: This study provides evidence of sequence variations across the different domains of sdrD from S. aureus isolated from healthy nasal carriers. Proper understanding of these variations is necessary in the study of S. aureus pathogenesis