| 1. |
- Gylfe, Åsa, et al.
(författare)
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Mosquitoborne Sindbis Virus Infection and Long-Term Illness
- 2018
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Ingår i: Emerging Infectious Diseases. - : Centers for Disease Control and Prevention (CDC). - 1080-6040 .- 1080-6059. ; 24:6, s. 1141-1142
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Tidskriftsartikel (refereegranskat)abstract
- An unexpected human outbreak of the mosquitoborne Sindbis virus occurred in a previously nonendemic area of Sweden. At follow-up, 6-8 months after infection, 39% of patients had chronic arthralgia that affected their daily activities. Vectorborne infections may disseminate rapidly into new areas and cause acute and chronic disease.
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| 2. |
- Agerhäll, Martin, et al.
(författare)
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High prevalence of pharyngeal bacterial pathogens among healthy adolescents and young adults
- 2021
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : John Wiley & Sons. - 0903-4641 .- 1600-0463. ; 129:12, s. 711-716
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Tidskriftsartikel (refereegranskat)abstract
- The pharyngeal mucosa can be colonized with bacteria that have potential to cause pharyngotonsillitis. By the use of culturing techniques and PCR, we aimed to assess the prevalence of bacterial pharyngeal pathogens among healthy adolescents and young adults. We performed a cross-sectional study in a community-based cohort of 217 healthy individuals between 16 and 25 years of age. Samples were analyzed for Group A streptococci (GAS), Group C/G streptococci (SDSE), Fusobacterium necrophorum, and Arcanobacterium haemolyticum. Compared to culturing, the PCR method resulted in more frequent detection, albeit in most cases with low levels of DNA, of GAS (20/217 vs. 5/217; p < 0.01) and F. necrophorum (20/217 vs. 8/217; p < 0.01). Culturing and PCR yielded similar rates of SDSE detection (14/217 vs. 12/217; p = 0.73). Arcanobacterium haemolyticum was rarely detected (3/217), and only by PCR. Overall, in 25.3% (55/217) of these healthy adolescents and young adults at least one of these pathogens was detected, a rate that is higher than previously described. Further studies are needed before clinical adoption of PCR-based detection methods for pharyngeal bacterial pathogens, as our findings suggest a high incidence of asymptomatic carriage among adolescents and young adults without throat infections.
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| 3. |
- Bailey, Leslie, et al.
(författare)
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Small molecule inhibitors of type III secretion in Yersinia block the Chlamydia pneumoniae infection cycle
- 2007
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Ingår i: FEBS Letters. - : Elsevier. - 0014-5793 .- 1873-3468. ; 581:4, s. 587-595
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Tidskriftsartikel (refereegranskat)abstract
- Intracellular parasitism by Chlamydiales is a complex process involving transmission of metabolically inactive particles that differentiate, replicate, and re-differentiate within the host cell. A type three secretion system (T3SS) has been implicated in this process. We have here identified small molecules of a chemical class of acylated hydrazones of salicylaldehydes that specifically blocks the T3SS of Chlamydia. These compounds also affect the developmental cycle showing that the T3SS has a pivotal role in the pathogenesis of Chlamydia. Our results suggest a previously unexplored avenue for development of novel anti-chlamydial drugs.
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| 4. |
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| 5. |
- Bao, Xiaofeng, et al.
(författare)
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Benzylidene acylhydrazides inhibit chlamydial growth in a type III secretion- and iron chelation-independent manner
- 2014
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Ingår i: Journal of Bacteriology. - : American Society for Microbiology. - 0021-9193 .- 1098-5530. ; 196:16, s. 2989-3001
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Tidskriftsartikel (refereegranskat)abstract
- Chlamydiae are widespread Gram-negative pathogens of humans and animals. Salicylidene acylhydrazides, developed as inhibitors of type III secretion system (T3SS) in Yersinia spp., have an inhibitory effect on chlamydial infection. However, these inhibitors also have the capacity to chelate iron, and it is possible that their antichlamydial effects are caused by iron starvation. Therefore, we have explored the modification of salicylidene acylhydrazides with the goal to uncouple the antichlamydial effect from iron starvation. We discovered that benzylidene acylhydrazides, which cannot chelate iron, inhibit chlamydial growth. Biochemical and genetic analyses suggest that the derivative compounds inhibit chlamydiae through a T3SS-independent mechanism. Four single nucleotide polymorphisms were identified in a Chlamydia muridarum variant resistant to benzylidene acylhydrazides, but it may be necessary to segregate the mutations to differentiate their roles in the resistance phenotype. Benzylidene acylhydrazides are well tolerated by host cells and probiotic vaginal Lactobacillus species and are therefore of potential therapeutic value.
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| 6. |
- Bergqvist, Joakim, et al.
(författare)
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Detection and Isolation of Sindbis Virus from Mosquitoes Captured During an Outbreak in Sweden, 2013
- 2015
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 15:2, s. 133-140
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Tidskriftsartikel (refereegranskat)abstract
- Mosquito-borne alphaviruses have the potential to cause large outbreaks throughout the world. Here we investigated the causative agent of an unexpected Sindbis virus (SINV) outbreak during August-September, 2013, in a previously nonendemic region of Sweden. Mosquitoes were collected using carbon dioxide-baited CDC traps at locations close to human cases. The mosquitoes were initially screened as large pools by SINV-specific quantitative RT-PCR, and the SINV-positive mosquitoes were species determined by single-nucleotide polymorphism (SNP) analysis, followed by sequencing the barcoding region of the cytochrome oxidase I gene. The proportion of the collected mosquitoes was determined by a metabarcoding strategy. By using novel strategies for PCR screening and genetic typing, a new SINV strain, Lovanger, was isolated from a pool of 1600 mosquitoes composed of Culex, Culiseta, and Aedes mosquitoes as determined by metabarcoding. The SINV-positive mosquito Culiseta morsitans was identified by SNP analysis and sequencing. After whole-genome sequencing and phylogenetic analysis, the SINV Lovanger isolate was shown to be most closely similar to recent Finnish SINV isolates. In conclusion, within a few weeks, we were able to detect and isolate a novel SINV strain and identify the mosquito vector during a sudden SINV outbreak.
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| 7. |
- Dahlgren, Markus K, et al.
(författare)
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Statistical molecular design of a focused salicylidene acylhydrazide library and multivariate QSAR of inhibition of type III secretion in the Gram-negative bacterium Yersinia
- 2010
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Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier BV. - 0968-0896 .- 1464-3391. ; 18:7, s. 2686-2703
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Tidskriftsartikel (refereegranskat)abstract
- A combined application of statistical molecular design (SMD), quantitative structure-activity relationship (QSAR) modeling and prediction of new active compounds was effectively used to develop salicylidene acylhydrazides as inhibitors of type III secretion (T3S) in the Gram-negative pathogen Yersinia pseudotuberculosis. SMD and subsequent synthesis furnished 50 salicylidene acylhydrazides in high purity. Based on data from biological evaluation in T3S linked assays 18 compounds were classified as active and 25 compounds showed a dose-dependent inhibition. The 25 compounds were used to compute two multivariate QSAR models and two multivariate discriminant analysis models were computed from both active and inactive compounds. Three of the models were used to predict 4416 virtual compounds in consensus and eight new compounds were selected as an external test set. Synthesis and biological evaluation of the test set in Y. pseudotuberculosis and the intracellular pathogen Chlamydia trachomatis validated the models. Y. pseudotuberculosis and C. trachomatis cell-based infection models showed that compounds identified in this study are selective and non-toxic inhibitors of T3S dependent virulence.
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| 8. |
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| 9. |
- Engström, Patrik, 1982-, et al.
(författare)
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Mutations in hemG Mediate Resistance to Salicylidene Acylhydrazides, Demonstrating a Novel Link between Protoporphyrinogen Oxidase (HemG) and Chlamydia trachomatis Infectivity
- 2013
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Ingår i: Journal of Bacteriology. - Washington DC, USA : American Society for Microbiology. - 0021-9193 .- 1098-5530. ; 195:18, s. 4221-4230
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Tidskriftsartikel (refereegranskat)abstract
- Salicylidene acylhydrazides (SAHs) inhibit the type III secretion system (T3S) of Yersinia and other Gram-negative bacteria. In addition, SAHs restrict the growth and development of Chlamydia species. However, since the inhibition of Chlamydia growth by SAH is suppressed by the addition of excess iron and since SAHs have an iron-chelating capacity, their role as specific T3S inhibitors is unclear. We investigated here whether SAHs exhibit a function on C. trachomatis that goes beyond iron chelation. We found that the iron-saturated SAH INP0341 (IS-INP0341) specifically affects C. trachomatis infectivity with reduced generation of infectious elementary body (EB) progeny. Selection and isolation of spontaneous SAH-resistant mutant strains revealed that mutations in hemG suppressed the reduced infectivity caused by IS-INP0341 treatment. Structural modeling of C. trachomatis HemG predicts that the acquired mutations are located in the active site of the enzyme, suggesting that IS-INP0341 inhibits this domain of HemG and that protoporphyrinogen oxidase (HemG) and heme metabolism are important for C. trachomatis infectivity.
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| 10. |
- Enquist, Per-Anders, et al.
(författare)
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Derivatives of 8-hydroxyquinoline-antibacterial agents that target intra- and extracellular Gram-negative pathogens
- 2012
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Ingår i: Bioorganic & Medicinal Chemistry Letters. - : Elsevier. - 0960-894X .- 1464-3405. ; 22:10, s. 3550-3553
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Tidskriftsartikel (refereegranskat)abstract
- Small molecule screening identified 5-nitro-7-((4-phenylpiperazine-1-yl-)methyl)quinolin-8-ol INP1750 as a putative inhibitor of type III secretion (T3S) in the Gram-negative pathogen Yersinia pseudotuberculosis. In this study we report structure-activity relationships for inhibition of T3S and show that the most potent compounds target both the extracellular bacterium Y. pseudotuberculosis and the intracellular pathogen Chlamydia trachomatis in cell-based infection models.
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| 11. |
- Good, James A. D., 1985-, et al.
(författare)
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Thiazolino 2-Pyridone Amide Inhibitors of Chlamydia trachomatis Infectivity
- 2016
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 59:5, s. 2094-2108
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Tidskriftsartikel (refereegranskat)abstract
- The bacterial pathogen Chlamydia trachomatis is a global health burden currently treated with broad-spectrum antibiotics which disrupt commensal bacteria. We recently identified a compound through phenotypic screening that blocked infectivity of this intracellular pathogen without host cell toxicity (compound 1, KSK 120). Herein, we present the optimization of 1 to a class of thiazolino 2-pyridone amides that are highly efficacious (EC50 <= 100 nM) in attenuating infectivity across multiple serovars of C. trachomatis without host cell toxicity. The lead compound 21a exhibits reduced lipophilicity versus 1 and did not affect the growth or viability of representative commensal flora at 50 mu M. In microscopy studies, a highly active fluorescent analogue 37 localized inside the parasitiphorous inclusion, indicative of a specific targeting of bacterial components. In summary, we present a class of small molecules to enable the development of specific treatments for C. trachomatis.
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| 12. |
- Good, James A. D., et al.
(författare)
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Thiazolino 2-pyridone amide isosteres as inhibitors of Chlamydia trachomatis infectivity
- 2017
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 60:22, s. 9393-9399
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Tidskriftsartikel (refereegranskat)abstract
- Chlamydia trachomatis is a global health burden due to its prevalence as a sexually transmitted disease and as the causative agent of the eye infection trachoma. We recently discovered 3-amido thiazolino 2-pyridones which attenuated C. trachomatis infectivity without affecting host cell or commensal bacteria viability. We present here the synthesis and evaluation of nonhydrolyzable amide isosteres based on this class, leading to highly potent 1,2,3-triazole based infectivity inhibitors (EC50 ≤ 20 nM).
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| 13. |
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| 14. |
- Gylfe, Åsa, et al.
(författare)
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Isolation of Lyme disease Borrelia from puffins (Fratercula arctica) and seabird ticks (Ixodes uriae) on the Faeroe Islands
- 1999
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 37:4, s. 890-896
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Tidskriftsartikel (refereegranskat)abstract
- This is the first report on the isolation of Lyme disease Borrelia from seabirds on the Faeroe Islands and the characteristics of its enzootic cycle. The major components of the Borrelia cycle include the puffin (Fratercula arctica) as the reservoir and Ixodes uriae as the vector. The importance of this cycle and its impact on the spread of human Lyme borreliosis have not yet been established. Borrelia spirochetes isolated from 2 of 102 sampled puffins were compared to the borreliae previously obtained from seabird ticks, I. uriae. The rrf-rrl intergenic spacer and the rrs and the ospC genes were sequenced and a series of phylogenetic trees were constructed. Sequence data and restriction fragment length polymorphism analysis grouped the strains together with Borrelia garinii. In a seroepidemiological survey performed with residents involved in puffin hunting on the Faeroe Islands, 3 of 81 serum samples were found to be positive by two commonly used clinical tests: a flagellin-based enzyme-linked immunosorbent assay (ELISA) and Western blotting. These three positive serum samples also had high optical density values in a whole-cell ELISA. The finding of seropositive Faeroe Islanders who are regularly exposed to I. uriae indicate that there may be a transfer of B. garinii by this tick species to humans.
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| 15. |
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| 16. |
- Gylfe, Åsa, et al.
(författare)
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Melioidos : en viktig diagnos vid svår sjukdom efter utlandsresa
- 2017
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Ingår i: Läkartidningen. - : Sveriges Läkarförbund. - 0023-7205 .- 1652-7518. ; 114
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Tidskriftsartikel (refereegranskat)abstract
- Melioidosis, an important diagnosis in the severely ill traveler Melioidosis is a common tropical infection in Southeast Asia and is caused by the highly pathogenic soil bacterium Burkholderia pseudomallei. Diagnosis and treatment is often challenging due to variations in clinical presentation, limited antibiotic susceptibility and high risk of recurring infection. In this report, three cases with different clinical presentations are described.
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| 17. |
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| 18. |
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| 19. |
- Gylfe, Åsa, 1972-
(författare)
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Role of birds in the biology of Lyme disease Borrelia
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lyme disease is a tick-transmitted illness caused by Borrelia burgdorferi sensu lato (s.l.), a group of spirochetes with at least three human pathogenic species, B. burgdorferi sensu stricto, B. afzelii and B. garinii. These spirochetes cycle between vertebrate reservoirs, mainly rodents, and ixodid ticks. Both terrestrial birds and seabirds can be infected with B. burgdorferi s.l. but the function of birds as reservoirs is largely unknown, even though they are potentially important epidemiologically due to their ability to carry ectoparasites and microorganisms over long distances. This thesis describes the role of birds in Lyme disease Borrelia biology in general and Borrelia ecology and epidemiology in particular.B. burgdorferi s.l. has previously been detected in the seabird tick Ixodes uriae and an enzootic Borrelia cycle distinct from terrestrial Borrelia cycles has been described. In this study B. garinii was isolated from the proposed seabird reservoirs and the tick I. uriae infesting them. The strains isolated did not show evident differences from human pathogenic B. garinii strains, indeed 7/8 strains had an ospC allele associated with Borrelia causing disseminated Lyme disease.Antibodies against B. burgdorferi s.l. were detected in people frequently bitten by I. uriae. Thus the marine enzootic Borrelia cycle may be a risk for humans, either by direct transfer of the spirochete from /. uriae or via introduction of Borrelia into a terrestrial enzootic Borrelia cycle.In order to investigate the role of passerine (Passeriformes) birds as amplification hosts in the terrestrial Borrelia cycle, experimental infections of canary finches (Serinus canaria) and redwing thrushes (Turdus iliacus) were carried out. The result showed that B. burgdorferi s.l. can persist for several months in passerine birds and the infection in redwing thrushes can be reactivated in response to migration. Thus, birds may be more infectious to ticks during their migration and therefore important long-range disseminators of B. burgdorferi s.l.Migration in birds is associated with elevated stress hormones that in turn can cause reactivation of latent infections. Lyme disease in humans could perhaps be activated when the immune response is modulated by stress. Herein I describe a patient with a stress activated latent Borrelia infection, which supports this hypothesis.The seabird tick I. uriae has a circumpolar distribution in both the northern and southern hemispheres and in this study identical B. garinii flagellin gene (flaB) sequences were detected in I. uriae from these hemispheres, indicating a transequatorial transport of B. garinii. Parsimony analysis of I. uriae ITS2 and 16S rDNA sequences suggested that northern and southern I. uriae might be reproductively separated. Therefore passive transport of infected ticks between the polar regions is unlikely and instead seabirds probably carry an active Borrelia infection during their migration.In conclusion, this work shows that migrating seabirds and passerine birds probably are important for the long-range dispersal of B. burgdorferi s.l., and that this mechanism of dispersal could be important for the distribution of human Lyme disease.
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| 20. |
- Ivarsson, Lovisa, et al.
(författare)
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Changes in testing and incidence of Chlamydia trachomatis and Neisseria gonorrhoeae : the possible impact of the COVID-19 pandemic in the three Scandinavian countries
- 2022
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Ingår i: Infectious Diseases. - : Taylor & Francis. - 2374-4235 .- 2374-4243. ; 52:9, s. 623-631
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Tidskriftsartikel (refereegranskat)abstract
- Background: This study aimed to investigate what impact the COVID-19 pandemic and its associated restrictions had on Chlamydia trachomatis and Neisseria gonorrhoeae infections in Sweden, Denmark and Norway, countries with very different governmental strategies for handling this pandemic.Methods: Retrospective analysis of data collected via requests to Swedish regions and to health authorities in Denmark and Norway. The data were collected for the years 2018-2020 and the data from Sweden were more detailed.Results: When the pandemic restrictions were installed in 2020, the number of reported chlamydia cases decreased. The decline was most pronounced in Norway 10.8% (2019: n = 28,446; 2020: n = 25,444) while it was only 3.1% in Denmark (2019: n = 35,688; 2020: n = 34,689) and 4.3% in Sweden (2019: n = 34,726; 2020: n = 33,339). Nucleic acid amplifications tests for chlamydia decreased in Sweden (10%) and Norway (18%) in 2020 compared to 2019, while in Denmark a 21% decrease was noted in April 2020 but thereafter increased to a higher level than 2019. The number of reported gonorrhoea cases decreased in Sweden (17%) and in Norway (39%) in 2020 compared to 2019, while a 21% increase was noted in Denmark.Conclusions: Pandemic restrictions had an impact on the number of reported chlamydia infections in all three countries, but only temporarily and did not seem to be correlated to the restriction levels. The number of reported gonorrhoea infections in Sweden and Norway significantly decreased but not in Denmark. Pandemic restrictions appear to have had a limited effect on the spread of chlamydia and gonorrhoea.
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| 21. |
- Kauppi, Anna M., et al.
(författare)
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Metabolites in Blood for Prediction of Bacteremic Sepsis in the Emergency Room
- 2016
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Ingår i: PLOS ONE. - : Public Library Science. - 1932-6203. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- A metabolomics approach for prediction of bacteremic sepsis in patients in the emergency room (ER) was investigated. In a prospective study, whole blood samples from 65 patients with bacteremic sepsis and 49 ER controls were compared. The blood samples were analyzed using gas chromatography coupled to time-of-flight mass spectrometry. Multivariate and logistic regression modeling using metabolites identified by chromatography or using conventional laboratory parameters and clinical scores of infection were employed. A predictive model of bacteremic sepsis with 107 metabolites was developed and validated. The number of metabolites was reduced stepwise until identifying a set of 6 predictive metabolites. A 6-metabolite predictive logistic regression model showed a sensitivity of 0.91(95% CI 0.69-0.99) and a specificity 0.84 (95% CI 0.58-0.94) with an AUC of 0.93 (95% CI 0.89-1.01). Myristic acid was the single most predictive metabolite, with a sensitivity of 1.00 (95% CI 0.85-1.00) and specificity of 0.95 (95% CI 0.74-0.99), and performed better than various combinations of conventional laboratory and clinical parameters. We found that a metabolomics approach for analysis of acute blood samples was useful for identification of patients with bacteremic sepsis. Metabolomics should be further evaluated as a new tool for infection diagnostics.
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| 22. |
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| 23. |
- Kulén, Martina, et al.
(författare)
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Methyl sulfonamide substituents improve the pharmacokinetic properties of bicyclic 2-pyridone based Chlamydia trachomatis inhibitors
- 2019
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Ingår i: MedChemComm. - : Royal Society of Chemistry. - 2040-2503 .- 2040-2511. ; 10:11, s. 1966-1987
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Tidskriftsartikel (refereegranskat)abstract
- Chlamydia trachomatis infections are a global health problem and new approaches to treat C. trachomatis with drugs of high specificity would be valuable. A library of substituted ring fused 2-pyridones has been synthesized and evaluated for their ability to attenuate C. trachomatis infectivity. In vivo pharmacokinetic studies were performed, with the best candidates demonstrating that a C8-methylsulfonamide substituent improved pharmacokinetic properties important for oral administration. C8-Methyl sulfonamide analogue 30 inhibited C. trachomatis infectivity in low micromolar concentrations. Further pharmacokinetic evaluation at an oral dose of 10 mg kg(-1) showed an apparent bioavailability of 41%, compared to C8-cyclopropyl and -methoxy analogues which had negligible oral uptake. In vitro ADME (absorption, distribution, metabolism and excretion) testing of solubility and Caco-2 cell permeability revealed that both solubility and permeability is greatly improved with the C8-methyl sulfonamide 30, effectively moving it from BCS (Biopharmaceutical Classification System) class IV to II.
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| 24. |
- Lu, Sai San Moon, et al.
(författare)
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Antibiotics Use and Subsequent Risk of Colorectal Cancer : A Swedish Nationwide Population-Based Study
- 2022
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press. - 0027-8874 .- 1460-2105. ; 114:1, s. 38-46
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Antibiotics use may increase colorectal cancer (CRC) risk by altering the gut microbiota, with suggestive evidence reported. Our study aims to investigate antibiotics use in relation to subsequent CRC risk.METHODS: This is a nationwide, population-based study with a matched case-control design (first primary CRC cases and 5 matched, cancer-free controls). Complete-population data, extracted from Swedish national registers for the period 2005-2016, were used to calculate odds ratios and 95% confidence intervals.RESULTS: We included 40 545 CRC cases and 202 720 controls. Using the full dataset, we found a positive association between more frequent antibiotics use and CRC, excluding antibiotics prescribed within 2 years of diagnosis attenuated results toward the null. In site-specific analyses, excluding the 2-year washout, the positive association was confined to the proximal colon (adjusted odds ratio for very high use vs no use = 1.17, 95% confidence interval = 1.05 to 1.31). For rectal cancer, an inverse association, which appears to be driven by women, was observed. Quinolones and sulfonamides and/or trimethoprims were positively associated with proximal colon cancer, whereas a more general inverse association, across antibiotics classes, was observed for rectal cancer. We found no association between methenamine hippurate, a urinary tract antiseptic not affecting the gut microbiota, and CRC risk.CONCLUSIONS: This register-based study covering the entire population of Sweden found a robust association between antibiotics use and higher risk of proximal colon cancer and an inverse association with rectal cancer in women. This study strengthens the evidence from previous investigations and adds important insight into site-specific colorectal carcinogenesis.
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| 25. |
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