| 1. |
- Björn, Camilla, et al.
(författare)
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Efficacy and safety profile of the novel antimicrobial peptide PXL150 in a mouse model of infected burn wounds
- 2015
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Ingår i: International Journal of Antimicrobial Agents. - : Elsevier BV. - 0924-8579 .- 1872-7913. ; 45:5, s. 519-524
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Tidskriftsartikel (refereegranskat)abstract
- The urgent need to develop novel antimicrobial therapies has stimulated interest in antimicrobial peptides as therapeutic candidates for the treatment of infectious diseases. The aim of this study was to evaluate the anti-infectious effect of the synthetic antimicrobial peptide PXL150, formulated in hydroxypropyl cellulose (HPC) gel, on Pseudomonas aeruginosa in vitro and in an in vivo mouse model of infected burn wounds as well as to assess the in vivo safety profile of PXL150 in rats and rabbits. Minimal microbicidal concentration analysis showed prominent efficacy of PXL150 against P. aeruginosa in vitro, which was further enhanced in formulating the peptide in HPC gel. Application of 1.25, 2.5, 5, 10 and 20 mg/g PXL150 in HPC gel twice daily for four consecutive days significantly reduced bacterial counts in the burn wounds compared with non-treated or placebo-treated controls. Continuous bioluminescence measurements of the bacteria revealed a pronounced anti-infective effect already at the first day post infection by PXL150 in concentrations of >= 2.5 mg/g. In the non-clinical safety studies, PXL150 showed a favourable safety profile following repeated administration systemically and locally in rats and rabbits, respectively. In conclusion, these data support that PXL150 has the potential to be an effective and safe drug candidate for the treatment of infected burn wounds. The findings encourage the progression of PXL150 as a novel topical treatment of microbial infections.
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| 2. |
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| 3. |
- Bunikis, J, et al.
(författare)
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Surface exposure and species specificity of an immunoreactive domain of a 66-kilodalton outer membrane protein (P66) of the Borrelia spp. that cause Lyme disease
- 1996
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Ingår i: Infection and Immunity. - 0019-9567 .- 1098-5522. ; 64:12, s. 5111-5116
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Tidskriftsartikel (refereegranskat)abstract
- A chromosomally encoded 66-kDa protein (P66) of Borrelia spp. that cause Lyme disease has previously been shown to be associated with the spirochetal outer membrane. A topological model of P66 predicts a surface-exposed fragment which links the N- and C-terminal intramembranous domains of the protein (J. Bunikis, L. Noppa, and S. Bergström, FEMS Microbiol. Lett. 131:139-145, 1995). In the present study, an immunogenic determinant of P66 was identified by a comparison of the immunoreactivities of different fragments of P66 generated either by proteolytic treatment of intact spirochetes or as recombinant proteins expressed in Escherichia coli. The immune response to P66 during natural infection was found to be directed against the predicted surface domain which comprises amino acids at positions 454 through 491. A sequence comparison revealed considerable polymorphism of the surface domains of P66 proteins of different Lyme disease-causing Borrelia species. Five sequence patterns of this domain were observed in the B. garinii strains studied. In contrast, sequences of the relevant part of P66 of the B. afzelii and B. burgdorferi sensu stricto isolates studied were identical within the respective species. In immunoblotting, 5 of 17 (29.4%) sera from North American patients with early disseminated or persistent Lyme disease reacted against P66 of B. burgdorferi sensu stricto B31. These sera, however, failed to recognize P66 of B. afzelii and B. garinii, as well as an analog of P66 in the relapsing fever agent, B. hermsii. In conclusion, the topological model of P66 is supported by the demonstration of an apparent surface localization of an immunoreactive domain of this protein. Furthermore, analogous to the plasmid-encoded borrelial outer surface proteins, the predicted surface-exposed portion of chromosomally encoded P66 appears to be antigenically heterogenous.
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| 4. |
- Forslund, Anna-Lena, 1964-, et al.
(författare)
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Direct repeat-mediated deletion of a type IV pilin gene results in major virulence attenuation of Francisella tularensis
- 2006
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Ingår i: Molecular Microbiology. - : Wiley-Blackwell. - 0950-382X .- 1365-2958. ; 59:6, s. 1818-1830
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Tidskriftsartikel (refereegranskat)abstract
- Francisella tularensis, the causative agent of tularaemia, is a highly infectious and virulent intracellular pathogen. There are two main human pathogenic subspecies, Francisella tularensis ssp. tularensis (type A), and Francisella tularensis ssp. holarctica (type B). So far, knowledge regarding key virulence determinants is limited but it is clear that intracellular survival and multiplication is one major virulence strategy of Francisella. In addition, genome sequencing has revealed the presence of genes encoding type IV pili (Tfp). One genomic region encoding three proteins with signatures typical for type IV pilins contained two 120 bp direct repeats. Here we establish that repeat-mediated loss of one of the putative pilin genes in a type B strain results in severe virulence attenuation in mice infected by subcutaneous route. Complementation of the mutant by introduction of the pilin gene in cis resulted in complete restoration of virulence. The level of attenuation was similar to that of the live vaccine strain and this strain was also found to lack the pilin gene as result of a similar deletion event mediated by the direct repeats. Presence of the pilin had no major effect on the ability to interact, survive and multiply inside macrophage-like cell lines. Importantly, the pilin-negative strain was impaired in its ability to spread from the initial site of infection to the spleen. Our findings indicate that this putative pilin is critical for Francisella infections that occur via peripheral routes.
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| 5. |
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| 6. |
- Jaenson, Thomas G. T., et al.
(författare)
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The ecology of lyme borreliosis in Sweden
- 1994. - 1
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Ingår i: Lyme borreliosis. - New York : Springer-Verlag New York. - 9781461524151 ; , s. 113-115
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The geographical distribution of Lyme borreliosis (Lb) in the North European countries appears to coincide with the geographical distribution of the principal vector, the common tick Ixodes ricinus. We have found that in Sweden this tick species occurs in the southern and south-central parts of the country and along the coast of northern Sweden. This area corresponds with the distributional area of Lyme borreliosis. I. ricinus, and thus also Borrelia burgdorferi s.l., are in general not present in the interior of North Sweden, presumably because the climate is too harsh for the vector.
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| 7. |
- Jonsson, Maria, et al.
(författare)
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Heterogeneity of outer membrane proteins in Borrelia burgdorferi : comparison of osp operons of three isolates of different geographic origins.
- 1992
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Ingår i: Infection and Immunity. - : American Society for Microbiology. - 0019-9567 .- 1098-5522. ; 60:5, s. 1845-53
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Tidskriftsartikel (refereegranskat)abstract
- Biochemical and immunochemical studies of the outer membrane proteins of Borrelia burgdorferi have shown that the OspA and OspB proteins from strains of different geographic origins may differ considerably in their reactivities with monoclonal antibodies and in their apparent molecular weights. To further characterize this variation in Osp proteins between strains, the osp operons and deduced translation products from two strains, one from Sweden (ACAI) and one from eastern Russia (Ip90), were studied. Polyacrylamide gel electrophoresis and Western blot (immunoblot) analyses confirmed differences between ACAI, Ip90, and the North American strain B31 in their Osp proteins. The sequences of the ospA and ospB genes of ACAI and Ip90 were compared with that of the previously studied osp operon of B31 (S. Bergström, V. G. Bundoc, and A. G. Barbour, Mol. Microbiol. 3:479-486, 1989). The osp genes of ACAI and Ip90, like the corresponding genes of B31, were found on plasmids with apparent sizes of about 50 kb and are cotranscribed as a single unit. Pairwise comparisons of the nucleotide sequences revealed that the ospA genes of ACAI and Ip90 were 85 and 86% identical, respectively, to the ospA gene of strain B31 and 86% identical to each other. The ospB sequences of these two strains were 79% identical to the ospB gene of B31 and 81% identical to each other. There was significantly greater similarity between the ospA genes of the three different strains than there was between the ospA and ospB genes within each strain. These studies suggest that the duplication of osp genes in B. burgdorferi occurred before the geographical dispersion of strains represented by ACAI, Ip90, and B31.
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