| 1. |
- Blomqvist, Maria, et al.
(författare)
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Chlamydia psittaci in birds of prey, Sweden
- 2012
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Ingår i: Infection Ecology and Epidemiology. - 2000-8686. ; 2, s. 8435-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chlamydia psittaci is an intracellular bacterium primarily causing respiratory diseases in birds but may also be transmitted to other animals, including humans. The prevalence of the pathogen in wild birds in Sweden is largely unknown. Methods: DNA was extracted from cloacae swabs and screened for C. psittaci by using a 23S rRNA gene PCR assay. Partial 16S rRNA and ompA gene fragments were sequence determined and phylogenies were analysed by the neighbour-joining method. Results and conclusion: The C. psittaci prevalence was 1.3% in 319 Peregrine Falcons and White-tailed Sea Eagles, vulnerable top-predators in Sweden. 16S rRNA and ompA gene analysis showed that novel Chlamydia species, as well as novel C. psittaci strains, are to be found among wild birds.
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| 2. |
- Blomqvist, Maria, et al.
(författare)
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Chlamydophila psittaci in birds of prey, Sweden
- 2012
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Ingår i: Infection Ecology & Epidemiology. - : Informa UK Limited. - 2000-8686. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chlamydia psittaci is an intracellular bacterium primarily causing respiratory diseases in birds but may also be transmitted to other animals, including humans. The prevalence of the pathogen in wild birds in Sweden is largely unknown.Methods: DNA was extracted from cloacae swabs and screened for C. psittaci by using a 23S rRNA gene PCR assay. Partial 16S rRNA and ompA gene fragments were sequence determined and phylogenies were analysed by the neighbour-joining method.Results and conclusion: The C. psittaci prevalence was 1.3% in 319 Peregrine Falcons and White-tailed Sea Eagles, vulnerable top-predators in Sweden. 16S rRNA and ompA gene analysis showed that novel Chlamydia species, as well as novel C. psittaci strains, are to be found among wild birds.
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| 3. |
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| 4. |
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| 5. |
- Blomqvist, Maria, et al.
(författare)
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Chlamydia psittaci in Swedish Wetland Birds : A Risk to Zoonotic Infection?
- 2012
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Ingår i: Avian diseases. - 0005-2086 .- 1938-4351. ; 56:4, s. 737-740
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Tidskriftsartikel (refereegranskat)abstract
- Chlamydia psittaci in birds may be transmitted to humans and cause respiratory infections, sometimes as severe disease. Our study investigated the C. psittaci prevalence in migratory birds in Sweden by real-time PCR. Fecal specimens or cloacal swabs were collected from 497 birds from 22 different species, mainly mallards (Anas platyrhynchos), at two bird observatories in Sweden. DNA from C. psittaci was found in six (1.2%) birds from three different species. Five of the positive specimens were infected with four novel strains of C. psittaci, based on sequencing of partial 16S rRNA gene and ompA gene, and the sixth was indentified as a recently described Chlamydiaceae-like bacterium. Considering exposure to humans it is concluded that the risk of zoonotic infection is low.
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| 6. |
- Christerson, Linus, et al.
(författare)
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A novel Chlamydiaceae-like bacterium found in faecal specimens from sea birds from the Bering Sea
- 2010
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Ingår i: Environmental Microbiology Reports. - : Wiley. - 1758-2229. ; 2:4, s. 605-610
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Tidskriftsartikel (refereegranskat)abstract
- The family Chlamydiaceae contains several bacterial pathogens of important human and veterinary medical concern, such as Chlamydia trachomatis and Chlamydophila psittaci. Within the order Chlamydiales there are also an increasing number of chlamydia-like bacteria whose biodiversity, host range and environmental spread seem to have been largely underestimated, and which are currently being investigated for their potential medical relevance. In this study we present 16S rRNA, rnpB and ompA gene sequence data congruently indicating a novel chlamydia-like bacterium found in faecal specimens from opportunistic fish-eating sea birds, belonging to the Laridae and Alcidae families, from the Bering Sea. This novel bacterium appears to be closer to the Chlamydiaceae than other chlamydia-like bacteria and is most likely a novel genus within the Chlamydiaceae family.
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| 7. |
- Christerson, Linus, 1985-
(författare)
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High Resolution Genotyping of Chlamydia trachomatis
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chlamydia trachomatis is an obligate intracellular bacterium of major human health concern, causing urogential chlamydia infections, lymphogranuloma venereum (LGV) and trachoma. Chlamydia is one of the most common sexually transmitted infections worldwide and can cause infertility. In the first four papers described herein we used a high resolution multilocus sequence typing (MLST) system to investigate the epidemiology of C. trachomatis, and showed that MLST is superior to conventional ompA genotyping with respect to resolution. In the fifth paper we simplified the methodology by developing and validating a multilocus typing (MLT) DNA microarray based on the MLST system. In more detail, MLST analysis of consecutive specimens from 2006 in Örebro County in Sweden, and comparison to specimens from 1999-2000, showed that the new variant C. trachomatis (nvCT) is monoclonal and likely has appeared in recent years. MLST analysis of LGV specimens from men who have sex with men (MSM) showed that the increase of LGV in Europe in the last decade indeed was a clonal outbreak, contrary to the USA where LGV might have been present all along. In the third paper, clinical symptoms could not be correlated with the MLST genotypes, suggesting, together with the combined results of all previous studies, that bacterial factors, if important, need to be understood in the context of host factors. MLST analysis of specimens from a high incidence C. trachomatis area in North Norway revealed interesting epidemiological details concerning unusual genetic variants, the nvCT and MSM, but found no significant difference in genetic diversity compared to two other geographic areas in Norway. Lastly, we developed a MLT array that provides high resolution while being rapid and cost-effective, which makes it an interesting alternative for C. trachomatis genotyping. In conclusion, the MLST system and the MLT array have proven to be useful tools and should now be applied in further investigations to improve our understanding of C. trachomatis epidemiology.
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| 8. |
- Fedirko, V., et al.
(författare)
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Prediagnostic circulating vitamin D levels and risk of hepatocellular carcinoma in European populations: A nested case-control study
- 2014
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Ingår i: Hepatology. - : Ovid Technologies (Wolters Kluwer Health). - 0270-9139 .- 1527-3350. ; 60:4, s. 1222-1230
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Tidskriftsartikel (refereegranskat)abstract
- The association between vitamin D status and hepatocellular carcinoma (HCC) has not been well investigated, despite experimental evidence supporting an important role of vitamin D in liver pathophysiology. Our objective was to investigate the association between prediagnostic circulating 25-hydroxyvitamin D [25(OH)D] serum levels and the risk of HCC in a prospective, nested case-control study among 520,000 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Each case (n=138) diagnosed between 1992 and 2010 was matched to one control by age, sex, study center, date and time of blood collection, and fasting status. Serum baseline levels of 25(OH)D were measured by liquid chromatography/tandem mass spectrometry. Multivariable incident rate ratios (IRRs) of HCC associated with continuous (per 10 nmol/L) or categorical levels (tertiles or a priori-defined categories) of prediagnostic 25(OH)D were calculated using conditional logistic regression. Higher 25(OH)D levels were associated with a 49% reduction in the risk of HCC (highest versus lowest tertile: multivariable IRR=0.51, 95% confidence interval [CI], 0.26 to 0.99; Ptrend=0.04; per 10 nmol/L increase: IRR=0.80, 95% CI, 0.68-0.94). The finding did not vary substantially by time from enrolment to diagnosis, and did not change after adjustment for biomarkers of preexisting liver damage, nor chronic infection with hepatitis B or C viruses. The findings were not modified by body size or smoking status. Conclusion: In this prospective study on western European populations, serum levels of 25(OH)D were inversely associated with the risk of HCC. Given the rising incidence of this cancer in low-risk developed countries and the strong public health interest surrounding the potentially cancer-protective roles of vitamin D, additional studies in different populations are required. © 2014 by the American Association for the Study of Liver Diseases.
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| 9. |
- Gonzalez-Acuna, Daniel, et al.
(författare)
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Health evaluation of wild gentoo penguins (Pygoscelis papua) in the Antarctic Peninsula
- 2013
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Ingår i: Polar Biology. - : Springer Science and Business Media LLC. - 0722-4060 .- 1432-2056. ; 36:12, s. 1749-1760
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Tidskriftsartikel (refereegranskat)abstract
- Historically wildlife conservation was based on habitat protection and exploitation control. Only recently have diseases been considered an important issue. However, pathogens are usually described during or after disease outbreaks, but to determine which pathogens may be emerging, surveys of wildlife health are critical in a given time. This study deals with the health status of gentoo penguins Pygoscelis papua in two localities at the Antarctica Peninsula and one at Ardley Island off the South Shetland Islands. Cloacal swaps, fresh fecal samples, ectoparasites, and blood smears were collected. We examined and dissected 14 penguin corpses found dead. Fecal samples were positive for Campylobacter, Escherichia coli and in the carcasses four endoparasitic species were found: Diphyllobothrium sp. and Parorchites zederi, Corynosoma shackletoni and Stegophorus adeliae. The tick Ixodes uriae occurred in five of the examined penguins, and the louse Austrogoniodes gressitti on six birds. From the colony grounds, we collected 1,184 I. uriae. We recorded antibiotic-resistant bacteria, such as E. coli, in ecosystems where gentoo penguins breed. Cloacal samples (300) were negative for Chlamydia, as well as for Salmonella, Campylobacter, E. coli, Newcastle and Influenza viruses.
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| 10. |
- Gunnarsson, Gunnar, et al.
(författare)
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Zero Prevalence of Influenza A Virus in Two Raptor Species by Standard Screening
- 2010
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Ingår i: Vector-borne and zoonotic diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 10:4, s. 387-390
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Tidskriftsartikel (refereegranskat)abstract
- Disease can have sever impact on animal populations, especially in rare species. Baseline data for atypical host species are missing for a range of infectious diseases, although such hosts are potentially more affected than the normal vectors and reservoir species. If highly pathogenic avian influenza strikes rare birds of prey, this may have crucial impact on the predator species itself, but also on the food web in which it interacts. Here we present the first large-scale screening of raptors that regularly consume birds belonging to the natural reservoir of influenza A viruses. Influenza A virus prevalence was studied in two rare raptors, the white-tailed sea eagle (Haliaetus albicilla) and the peregrine falcon (Falco peregrinus). Nestlings were screened for active (181 white-tailed sea eagles and 168 peregrine falcons) and past (123 white-tailed sea eagles and 6 peregrine falcons) infection in 2006-2007, and an additional 20 succumbed adult white-tailed sea eagles were sampled in 2003-2006. Neither high- nor low-pathogenic influnza infections were found in our sample, but this does not rule out that the former may have major impact on rare raptors and their food webs.
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| 11. |
- Rehn, M., et al.
(författare)
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Unusual increase of psittacosis in southern Sweden linked to wild bird exposure, January to April 2013
- 2013
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Ingår i: Eurosurveillance. - 1025-496X .- 1560-7917. ; 18:19, s. 13-20
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Tidskriftsartikel (refereegranskat)abstract
- Free-living wild birds worldwide act as reservoir for Chlamydia psittaci, but the risk of transmission to humans through contact with wild birds has not been widely documented. From 12 January to April 9 2013, a total of 25 cases of psittacosis were detected in southern Sweden, about a threefold increase compared with the mean of the previous 10 years. A matched case-control study investigating both domestic and wild bird exposure showed that cases were more likely than controls to have cleaned wild bird feeders or been exposed to wild bird droppings in other ways (OR: 10.1; 95% CI: 2.1-47.9). We recommend precautionary measures such as wetting bird feeders before cleaning them, to reduce the risk of transmission of C. psittaci when in contact with bird droppings. Furthermore, C. psittaci should be considered for inclusion in laboratory diagnostic routines when analysing samples from patients with atypical pneumonia, since our findings suggest that psittacosis is underdiagnosed.
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| 12. |
- Accinelli, Cesare, et al.
(författare)
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Dissipation and removal of oseltamivir (Tamiflu) in different aquatic environments
- 2010
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 79:8, s. 891-897
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Tidskriftsartikel (refereegranskat)abstract
- The antiviral drug oseltamivir (Tamiflu) has received recent attention due to the potential use as a first-line defense against H5N1 and H1N1 influenza viruses. Research has shown that oseltamivir is not removed during conventional wastewater treatments, thus having the potential to enter surface water bodies. A series of laboratory experiments investigated the fate and the removal of oseltamivir in two surface water ecosystems of Japan and in a municipal wastewater treatment plant located in Northern Italy. Persistence of oseltamivir in surface water ranged from non-detectable degradation to a half-life of 53 d. After 40 d, <3% of radiolabeled oseltamivir evolved as (CO2)-C-14. The presence of sediments (5%) led to a significant increase of oseltamivir degradation and mineralization rates. A more intense mineralization was observed in samples of the wastewater treatment plant when applying a long incubation period (40 d). More precisely, 76% and 37% of the initial radioactivity applied as C-14-oseltamivir was recovered as (CO2)-C-14 from samples of the biological tank and effluent water, respectively. Two bacterial strains growing on oseltamivir as sole carbon source were isolated and used for its removal from synthetic medium and environmental samples, including surface water and wastewater. Inoculation of water and wastewater samples with the two oseltamivir-degrading strains showed that mineralization of oseltamivir was significantly higher in both inoculated water and wastewater, than in uninoculated controls. Denaturing gradient gel electrophoresis and quantitative PCR analysis showed that Tamiflu would not affect the microbial population of surface water and wastewater.
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| 13. |
- Antonodimitrakis, Pantelis, et al.
(författare)
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Fulminant hemophagocytic lymphohistiocytosis secondary to a reactivated EBV infection : A case report
- 2013
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Ingår i: Upsala Journal of Medical Sciences. - : Uppsala Medical Society. - 0300-9734 .- 2000-1967. ; 118:1, s. 42-45
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Tidskriftsartikel (refereegranskat)abstract
- Hemophagocytic lymphohistiocytosis (HLH) is an aggressive inflammatory syndrome that results from inappropriate activation of the immune system. HLH has a high mortality if not treated. We describe a case of a fulminant HLH, associated with a reactivation of an EBV infection. The patient responded well to steroid treatment.
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| 14. |
- Ardiles-Villegas, Karen, et al.
(författare)
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Antibiotic resistance patterns in fecal bacteria isolated from Christmas shearwater (Puffinus nativitatis) and masked booby (Sula dactylatra) at remote Easter Island
- 2011
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Ingår i: Avian diseases. - 0005-2086 .- 1938-4351. ; 55:3, s. 486-489
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Tidskriftsartikel (refereegranskat)abstract
- Antibiotic use and its implications have been discussed extensively in the past decades. This situation has global consequences when antibiotic resistance becomes widespread in the intestinal bacterial flora of stationary and migratory birds. This study investigated the incidence of fecal bacteria and general antibiotic resistance, with special focus on extended spectrum beta-lactamase (ESBL) isolates, in two species of seabirds at remote Easter Island. We identified 11 species of bacteria from masked booby (Sula dactylatra) and Christmas shearwater (Puffinus nativitatis); five species of gram-negative bacilli, four species of Streptococcus (Enterococcus), and 2 species of Staphylococcus. In addition, 6 types of bacteria were determined barely to the genus level. General antibiotic susceptibility was measured in the 30 isolated Enterobacteriaceae to 11 antibiotics used in human and veterinary medicine. The 10 isolates that showed a phenotypic ESBL profile were verified by clavulanic acid inhibition in double mixture discs with cefpodoxime, and two ESBL strains were found, one strain in masked booby and one strain in Christmas shearwater. The two bacteria harboring the ESBL type were identified as Serratia odorifera biotype 1, which has zoonotic importance. Despite minimal human presence in the masked booby and Christmas shearwater habitats, and the extreme geographic isolation of Easter Island, we found several multiresistant bacteria and even two isolates with ESBL phenotypes. The finding of ESBLs has animal and public health significance and is of potential concern, especially because the investigation was limited in size and indicated that antibiotic-resistant bacteria now are distributed globally.
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| 15. |
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| 16. |
- Axelsson Olsson, Diana, et al.
(författare)
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Amoebae and algae can prolong the survival of Campylobacter species in co-culture
- 2010
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Ingår i: Experimental parasitology. - : Elsevier BV. - 0014-4894 .- 1090-2449. ; 126:1, s. 59-64
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Tidskriftsartikel (refereegranskat)abstract
- Several species of free-living amoebae can cause disease in humans. However, in addition to the direct pathogenicity of e.g. Acanthamoebae and Naegleria species, they are recognized as environmental hosts, indirectly involved in the epidemiology of many pathogenic bacteria. Although several studies have demonstrated intracellular survival of many different bacteria in these species, the extent of such interactions as well as the implications for the epidemiology of the bacterial species involved, are largely unknown and probably underestimated. In this study, we evaluated eight different unicellular eukaryotic organisms, for their potential to serve as environmental hosts for Campylobacter species. These organisms include four amoebozoas (Acanthamoeba polyphaga, Acanthamoeba castellanii, Acanthamoeba rhysodes and Hartmanella vermiformis), one alveolate (Tetrahymena pyriformis), one stramenopile (Dinobryon sertularia), one eugoenozoa (Euglena gracilis) and one heterolobosea (Naegleria americana). Campylobacter spp. including Campylobacter jejuni, Campylobacter coli and Campylobacter lari are the most common cause of gastroenteritis in the western world. Survival and replication of these three species as well as Campylobacter hyointestinalis were assessed in co-cultures with the eukaryotic organisms. Campylobacter spp. generally survived longer in co-cultures, compared to when incubated in the corresponding growth media. The eukaryotic species that best promoted bacterial survival was the golden algae D. sertularia. Three species of amoebozoas, of the genus Acanthamoeba promoted both prolonged survival and replication of Campylobacter spp. The high abundance in lakes, ponds and water distribution networks of these organisms indicate that they might have a role in the epidemiology of campylobacteriosis, possibly contributing to survival and dissemination of these intestinal pathogens to humans and other animals. The results suggest that not only C. jejuni, but a variety of Campylobacter spp. can interact with different eukaryotic unicellular organisms.
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| 17. |
- Axelsson Olsson, Diana, et al.
(författare)
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Increase in Acid Tolerance of Campylobacter jejuni through Coincubation with Amoebae
- 2010
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Ingår i: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 76:13, s. 4194-4200
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Tidskriftsartikel (refereegranskat)abstract
- Campylobacter jejuni is a recognized and common gastrointestinal pathogen in most parts of the world. Human infections are often food borne, and the bacterium is frequent among poultry and other food animals. However, much less is known about the epidemiology of C. jejuni in the environment and what mechanisms the bacterium depends on to tolerate low pH. The sensitive nature of C. jejuni stands in contrast to the fact that it is difficult to eradicate from poultry production, and even more contradictory is the fact that the bacterium is able to survive the acidic passage through the human stomach. Here we expand the knowledge on C. jejuni acid tolerance by looking at protozoa as a potential epidemiological pathway of infection. Our results showed that when C. jejuni cells were coincubated with Acanthamoeba polyphaga in acidified phosphate-buffered saline (PBS) or tap water, the bacteria could tolerate pHs far below those in their normal range, even surviving at pH 4 for 20 h and at pH 2 for 5 h. Interestingly, moderately acidic conditions (pH 4 and 5) were shown to trigger C. jejuni motility as well as to increase adhesion/internalization of bacteria into A. polyphaga. Taken together, the results suggest that protozoa may act as protective hosts against harsh conditions and might be a potential risk factor for C. jejuni infections. These findings may be important for our understanding of C. jejuni passage through the gastrointestinal tract and for hygiene practices used in poultry settings.
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| 18. |
- Bengtsson, Daniel, et al.
(författare)
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Movements, Home-Range Size and Habitat Selection of Mallards during Autumn Migration
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:6
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Tidskriftsartikel (refereegranskat)abstract
- The mallard (Anas platyrhynchos) is a focal species in game management, epidemiology and ornithology, but comparably little research has focused on the ecology of the migration seasons. We studied habitat use, time-budgets, home-range sizes, habitat selection, and movements based on spatial data collected with GPS devices attached to wild mallards trapped at an autumn stopover site in the Northwest European flyway. Sixteen individuals (13 males, 3 females) were followed for 15-38 days in October to December 2010. Forty-nine percent (SD = 8.4%) of the ducks' total time, and 85% of the day-time (SD = 28.3%), was spent at sheltered reefs and bays on the coast. Two ducks used ponds, rather than coast, as day-roosts instead. Mallards spent most of the night (76% of total time, SD = 15.8%) on wetlands, mainly on alvar steppe, or in various flooded areas (e.g. coastal meadows). Crop fields with maize were also selectively utilized. Movements between roosting and foraging areas mainly took place at dawn and dusk, and the home-ranges observed in our study are among the largest ever documented for mallards (mean = 6,859 ha; SD = 5,872 ha). This study provides insights into relatively unknown aspects of mallard ecology. The fact that autumn-staging migratory mallards have a well-developed diel activity pattern tightly linked to the use of specific habitats has implications for wetland management, hunting and conservation, as well as for the epidemiology of diseases shared between wildlife and domestic animals.
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| 19. |
- Bonnedahl, Jonas, 1970-
(författare)
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Antibiotic Resistance in Enterobacteriaceae Isolated from Wild Birds
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The presence and spread of clinically important antibiotic-resistant bacteria in reservoirs from natural environments are not well studied compared to the clinical environments. The overall aim of this project was to study the presence of clinically important antibiotic-resistant bacteria in a reservoir from natural environments. Wild birds were chosen not only as indicators of the level of antibiotic resistance in surrounding natural bacterial populations, but also since birds can act as vectors of several potential pathogens including enteropathogens and because they by migration have an ability to spread these pathogens across geographical regions. The studies in this thesis showed that wild birds carry antibiotic-resistant enterobacteriaceae. The levels and spectrum of antibiotic resistance varies between different bird populations and geographical regions. In bird populations without interaction with human activities throughout the year, antibiotic resistance is lacking. Antibiotic-resistant bacteria could however probably be dispersed to remote regions by bird migration. Extended-spectrum beta-lactamases (ESBLs) and especially CTX-M types are found in comparable high levels in gull populations considering the recent emergence of these resistance genes in clinical settings. The CTX-M types found in wild birds are the same types that are found in clinical settings and in food producing animals from the same regions. ESBL-producing E. coli isolated from Yellow-legged Gulls are genetically heterogenous, reflecting that these resistance genes are present across the full E. coli genetic diversity. In wild birds CTX-M are found both in E. coli strains with previously known “human signature” as well as “novel” strains. This indicates that these genes are indeed very mobile and rapidly dispersing both through horizontal gene transfer and through successful clones. The findings in this thesis indicate that bird colonies could act as melting pots and reservoirs for new resistance types and that wild birds could act as important indicators of the level of antibiotic resistance dispersal in natural environments.
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| 20. |
- Bonnedahl, Jonas, et al.
(författare)
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Characterization, and comparison, of human clinical and black-headed gull (Larus ridibundus) extended-spectrum beta-lactamase-producing bacterial isolates from Kalmar, on the southeast coast of Sweden
- 2010
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Ingår i: Journal of Antimicrobial Chemotherapy. - : Oxford University Press (OUP). - 0305-7453 .- 1460-2091. ; 65:9, s. 1939-1944
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Tidskriftsartikel (refereegranskat)abstract
- Antibiotic resistance is one of the great challenges for modern healthcare. In Gram-negative bacteria, CTX-M-type extended-spectrum beta-lactamases (ESBLs) have been rapidly spreading through Europe since the early 2000s. In Sweden, ESBL-producing Escherichia coli are still rare, but a 3-fold increase has been seen from 2004 to 2007. Enterobacteria and normal flora of wild animals, with or without antibiotic resistance traits, constitute a potential source of human infection and colonization. We studied wild birds with the aim to understand the environmental dissemination of antibiotic resistance and, focusing on clinically relevant resistance types, we made comparisons with human clinical samples. In this study, ESBL-producing human clinical isolates and isolates from juvenile black-headed gulls from Kalmar County hospital and the city of Kalmar, respectively, on the southeast coast of Sweden, were characterized and compared. Despite a low frequency of antibiotic resistance among the isolates from gulls, ESBL-producing E. coli isolates were found, two with bla(CTX-M-14) and one with bla(CTX-M-15). The same CTX-M types were dominant among human ESBL isolates. In addition, gull isolates were dispersed among the human samples in the PhenePlate (TM) clustering system, indicating that they neither differ from the human isolates nor form any separate clonal clustering. The finding of CTX-M-type ESBLs in E. coli isolated from black-headed gulls in Sweden, where 'background resistance' is low, is consistent with an ongoing environmental spread of these plasmid-borne resistance genes. The results indicate that a potential for transfer between the human population and environment exists even in countries with a low level of antibiotic resistance.
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| 21. |
- Bonnedahl, Jonas, et al.
(författare)
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Characterization, and comparison, of human clinical and black-headed gull (Larus ridibundus) extended-spectrum β-lactamase-producing bacterial isolates from Kalmar, on the southeast coast of Sweden
- 2010
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Ingår i: Journal of Antimicrobial Chemotherapy. - : Oxford University Press (OUP). - 0305-7453 .- 1460-2091. ; 65:9, s. 1939-1944
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Tidskriftsartikel (refereegranskat)abstract
- Antibiotic resistance is one of the great challenges for modern healthcare. In Gram-negative bacteria, CTX-M-type extended-spectrum beta-lactamases (ESBLs) have been rapidly spreading through Europe since the early 2000s. In Sweden, ESBL-producing Escherichia coli are still rare, but a 3-fold increase has been seen from 2004 to 2007. Enterobacteria and normal flora of wild animals, with or without antibiotic resistance traits, constitute a potential source of human infection and colonization. We studied wild birds with the aim to understand the environmental dissemination of antibiotic resistance and, focusing on clinically relevant resistance types, we made comparisons with human clinical samples. In this study, ESBL-producing human clinical isolates and isolates from juvenile black-headed gulls from Kalmar County hospital and the city of Kalmar, respectively, on the southeast coast of Sweden, were characterized and compared. Despite a low frequency of antibiotic resistance among the isolates from gulls, ESBL-producing E. coli isolates were found, two with bla(CTX-M-14) and one with bla(CTX-M-15). The same CTX-M types were dominant among human ESBL isolates. In addition, gull isolates were dispersed among the human samples in the PhenePlate (TM) clustering system, indicating that they neither differ from the human isolates nor form any separate clonal clustering. The finding of CTX-M-type ESBLs in E. coli isolated from black-headed gulls in Sweden, where 'background resistance' is low, is consistent with an ongoing environmental spread of these plasmid-borne resistance genes. The results indicate that a potential for transfer between the human population and environment exists even in countries with a low level of antibiotic resistance.
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| 22. |
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| 23. |
- Bröjer, Caroline, et al.
(författare)
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Pathobiology and virus shedding of low-pathogenic avian influenza virus (A/H1N1) infection in mallards exposed to oseltamivir
- 2013
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Ingår i: Journal of Wildlife Diseases. - : Wildlife Disease Association. - 0090-3558 .- 1943-3700. ; 49:1, s. 103-113
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Tidskriftsartikel (refereegranskat)abstract
- Low-pathogenic avian influenza (LPAI) viruses in wild birds are important as they can constitute the basis for the development of highly pathogenic avian influenza viruses or form part of human-adapted strains with pandemic potential. However, the pathogenesis of LPAI viruses is not well characterized in dabbling ducks, one of the natural reservoirs of LPAI viruses. Between 21 September 2009 and 21 December 2009, we used real-time reverse transcriptase polymerase chain reaction (q-PCR), histopathology, and immunohistochemistry (IHC) to study Mallards (Anas platyrhynchos) infected with an influenza A/H1N1 virus isolated from a wild Mallard in Sweden. The ducks were either inoculated intraesophageally ("artificial infection") or infected by virus shed by other ducks in the experiment ("contact infection"). The ducks were subjected to three low concentrations (80 ng/L, 1 mu g/L, and 80 mu g/L) of the active metabolite of oseltamivir (Tamiflu (R)), oseltamivir carboxylate (OC), which resulted in the development of the viral resistance mutation H274Y at 1 and 80 mu g/L. The LPAI virus infection was localized to the intestinal tract and cloacal bursa except in one Mallard. The exception was a duck euthanized 1 day postinoculation, whose infection was located solely in the lung, possibly due to intratracheal deposition of virus. The intestinal infection was characterized by occasional degenerating cells in the lamina propria and presence of viral antigen as detected by IHC, as well as positive q-PCR performed on samples from feces and intestinal contents. Histopathologic changes, IHC positivity, and viral shedding all indicated that the infection peaked early, around 2 days postinfection. Furthermore, more viral antigen and viral RNA were detected with IHC and q-PCR in the proximal parts early in the infection. There was no obvious difference in the course of the infection in artificial versus contact infection, when the level of OC was increased from 80 ng/L to 1 mu g/L (based on IHC and q-PCR), when the level of OC was increased to 80 mu/L, or when the resistance mutation H274Y developed (based on q-PCR).
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| 24. |
- Chryssanthou, E., et al.
(författare)
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Occurrence of yeasts in faecal samples from Antarctic and South American seabirds
- 2011
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Ingår i: Mycoses. - : Wiley. - 0933-7407 .- 1439-0507. ; 54:6, s. E811-E815
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Tidskriftsartikel (refereegranskat)abstract
- During an expedition to the Southern Argentinean town of Ushuaia, the Antarctic Peninsula, Antarctic Islands and the Falkland Islands, we collected 94 faecal specimens from wild birds to screen for yeast within the different bird species. The yeast species were identified by morphological features and commercial characterisation kits. From 54% of the specimens, we isolated 122 strains representing 29 yeast species. Debaryomyces hansenii, Candida lambica and Candida krusei were the most frequently isolated species. We found a plethora of yeasts in birds living in proximity to humans, whereas birds living in more remote areas were colonised with a lower number of fungal species.
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| 25. |
- De Marco, Marina, et al.
(författare)
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Mitral annular calcification and incident ischemic stroke in treated hypertensive patients : the LIFE study
- 2013
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Ingår i: American Journal of Hypertension. - : Oxford University Press (OUP). - 0895-7061 .- 1941-7225. ; 26:4, s. 567-573
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND Fibro-calcification of the mitral annulus (MAC) has been associated with increased risk of ischemic stroke in general populations. This study was performed to assess whether MAC predicts incidence of ischemic stroke in treated hypertensive patients with left ventricular hypertrophy (LVH).METHODS Baseline and follow-up clinical and echocardiographic parameters were assessed in 939 hypertensive patients with electrocardiogram (ECG) LVH participating in the Losartan Intervention for Endpoint reduction in hypertension (LIFE) echocardiography substudy (66 +/- 7 years; 42% women; 11% with diabetes) who did not have aortic or mitral valve stenosis or prosthesis.RESULTS MAC was found in 458 patients (49%). Patients with MAC were older (68 +/- 7 vs. 65 +/- 7 years); were more often women (47% vs. 37%); had higher baseline systolic blood pressure (BP) (175 +/- 14 vs. 172 +/- 15 mm Hg), left atrial diameter (4.0 +/- 0.5 vs. 3.8 +/- 0.6 cm), and left ventricular mass index (58 +/- 13 vs. 55 +/- 12 g/m(2.7)) and included more patients with proteinuria (30% vs. 21%; all P < 0.01). During a mean follow-up of 4.8 years, 58 participants had an ischemic stroke. Risk of incident ischemic stroke was significantly related to presence of MAC (log rank = 9; P < 0.01). In multivariable Cox regression analysis models, MAC was associated with increased risk of ischemic stroke (hazard ratio = 1.78-2.35), independent of age, baseline or time-varying systolic BR prevalence or incidence of atrial fibrillation, history of previous cerebrovascular disease, and other well-recognized confounders, such as sex, time-varying left ventricular mass, left atrial diameter, and urinary albumin/creatinine ratio (all P < 0.05).CONCLUSIONS MAC is common in treated hypertensive patients with ECG LVH and is an independent predictor of incident ischemic stroke.
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