| 1. |
- Artursson, Karin, et al.
(författare)
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Foodborne pathogens in unpasteurized milk in Sweden
- 2018
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Ingår i: International Journal of Food Microbiology. - : Elsevier BV. - 0168-1605 .- 1879-3460. ; 284, s. 120-127
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Tidskriftsartikel (refereegranskat)abstract
- Raw milk may be a risk for public health if it is contaminated with zoonotic pathogens. To study the prevalencein unpasteurized milk from Swedish farms, bovine and small ruminant dairy farms were sampled. Since thesampling method and transport conditions may influence the outcome of analyses, efforts were made to optimizethe methodology. Culturing of bacteria was done from in-line milk filters collected from the milk pipe at thepoint where it enters the milk bulk tank at the farms and this way of sampling was compared to sampling bulktank milk (BTM) directly. Analysing milk filters were found to be superior to analysing BTM directly. Conditionsfor transport of milk filter samples were further improved by the addition of Cary Blair transport medium, whichsignificantly increased the number of positive samples for pathogenic bacteria. The isolation of several foodbornepathogens from milk filters was demonstrated. The prevalence of samples with Staphylococcus aureus was71% and 64%, and Listeria spp. 21% and 29% from dairy cow and goat/sheep farms, respectively. Campylobacterjejuni, Yersinia enterocolitica and verotoxigenic Escherichia coli (VTEC) O157 were detected in 9%, 2% and 2% ofsamples from bovine milk, respectively.We conclude that the choice of sampling method and sample handling influence the results of bacterialculturing. From the results of this study, we strongly recommend to sample in-line milk filters instead of BTMdirectly and to use Cary Blair medium during transport, especially if the samples are to be analysed forCampylobacter spp. and/or Listeria spp. The findings also show that unpasteurized milk from Swedish farmsoccasionally contain bacteria with zoonotic potential.
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| 2. |
- Davidsson, Anette, et al.
(författare)
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Influence of reconstruction algorithms on image quality in SPECT myocardial perfusion imaging
- 2017
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Ingår i: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 37:6, s. 655-662
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: We investigated if image- and diagnostic quality in SPECT MPI could be maintained despite a reduced acquisition time adding Depth Dependent Resolution Recovery (DDRR) for image reconstruction. Images were compared with filtered back projection (FBP) and iterative reconstruction using Ordered Subsets Expectation Maximization with (IRAC) and without (IRNC) attenuation correction (AC).MATERIALS AND METHODS: Stress- and rest imaging for 15 min was performed on 21 subjects with a dual head gamma camera (Infinia Hawkeye; GE Healthcare), ECG-gating with 8 frames/cardiac cycle and a low-dose CT-scan. A 9 min acquisition was generated using five instead of eight gated frames and was reconstructed with DDRR, with (IRACRR) and without AC (IRNCRR) as well as with FBP. Three experienced nuclear medicine specialists visually assessed anonymized images according to eight criteria on a four point scale, three related to image quality and five to diagnostic confidence. Statistical analysis was performed using Visual Grading Regression (VGR).RESULTS: Observer confidence in statements on image quality was highest for the images that were reconstructed using DDRR (P<0·01 compared to FBP). Iterative reconstruction without DDRR was not superior to FBP. Interobserver variability was significant for statements on image quality (P<0·05) but lower in the diagnostic statements on ischemia and scar. The confidence in assessing ischemia and scar was not different between the reconstruction techniques (P = n.s.).CONCLUSION: SPECT MPI collected in 9 min, reconstructed with DDRR and AC, produced better image quality than the standard procedure. The observers expressed the highest diagnostic confidence in the DDRR reconstruction.
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| 3. |
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| 4. |
- De Geer, Jakob, et al.
(författare)
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Large variation in blood flow between left ventricular segments, as detected by adenosine stress dynamic CT perfusion.
- 2015
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 35:4, s. 291-300
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Dynamic cardiac CT perfusion (CTP) is based on repeated imaging during the first-pass contrast agent inflow. It is a relatively new method that still needs validation.PURPOSE: To evaluate the variation in adenosine stress dynamic CTP blood flow as compared to (99m) Tc SPECT. Secondarily, to compare manual and automatic segmentation.METHODS: Seventeen patients with manifest coronary artery disease were included. Nine were excluded from evaluation for various reasons. All patients were examined with dynamic stress CTP and stress/rest SPECT. CTP blood flow was compared with SPECT on a per segment basis. Results for manual and automated AHA segmentation were compared.RESULTS: CTP showed a positive correlation with SPECT, with correlation coefficients of 0·38 and 0·41 for manual and automatic segmentation, respectively (P<0·0001). There was no significant difference between the correlation coefficients of the manual and automated segmentation procedures (P = 0·75). The average per individual global CTP blood flow value for normal segments varied by a factor of 1·9 (manual and automatic segmentation). For the whole patient group, the CTP blood flow value in normal segments varied by a factor of 2·9/2·7 (manual/automatic segmentation). Within each patient, the average per segment blood flow in normal segments varied by a factor of 1·3-2·0/1·2-2·1 (manual/automatic segmentation).CONCLUSION: A positive but rather weak correlation was found between CTP and (99m) Tc SPECT. Large variations in CTP blood flow suggest that a cut-off value for stress myocardial blood flow is inadequate to detect ischaemic segments. Dynamic CTP is hampered by a limited coverage.
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| 5. |
- Ellström, Patrik, et al.
(författare)
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Lipooligosaccharide locus classes and putative virulence genes among chicken and human Campylobacter jejuni isolates
- 2016
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Ingår i: BMC Microbiology. - : Springer Science and Business Media LLC. - 1471-2180. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Background: Campylobacter cause morbidity and considerable economic loss due to hospitalization and post infectious sequelae such as reactive arthritis, Guillain Barr-and Miller Fischer syndromes. Such sequelae have been linked to C. jejuni harboring sialic acid structures in their lipooligosaccharide (LOS) layer of the cell wall. Poultry is an important source of human Campylobacter infections but little is known about the prevalence of sialylated C. jejuni isolates and the extent of transmission of such isolates to humans. Results: Genotypes of C. jejuni isolates from enteritis patients were compared with those of broiler chicken with pulsed-field gel electrophoresis (PFGE), to study the patterns of LOS biosynthesis genes and other virulence associated genes and to what extent these occur among Campylobacter genotypes found both in humans and chickens. Chicken and human isolates generally had similar distributions of the putative virulence genes and LOS locus classes studied. However, there were significant differences regarding LOS locus class of PFGE types that were overlapping between chicken and human isolates and those that were distinct to each source. Conclusions: The study highlights the prevalence of virulence associated genes among Campylobacter isolates from humans and chickens and suggests possible patterns of transmission between the two species.
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| 6. |
- Griekspoor, Petra, et al.
(författare)
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Genetic diversity and host associations in Campylobacter jejuni from human cases and broilers in 2000 and 2008
- 2015
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 178:1-2, s. 94-98
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Tidskriftsartikel (refereegranskat)abstract
- Campylobacter jejuni is an important food-borne pathogen, with a global distribution. It can colonize numerous host species, including both domestic and wild animals, but is particularly associated with birds (poultry and wild birds). For human campylobacteriosis, poultry products are deemed the most significant risk factor for acquiring infection. We conducted a genotyping and host attribution study of a large representative collection of C. jejuni isolated from humans and broilers in Sweden in the years 2000 and 2008. In total 673 broiler and human isolates from 10 different abattoirs and 6 different hospitals were genotyped with multilocus sequence typing. Source attribution analyses confirmed the strong linkage between broiler C. jejuni and domestic human cases, but also indicated a significant association to genotypes more commonly found in wild birds. Genotype distributions did not change dramatically between the two study years, suggesting a stable population of infecting bacteria.
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| 7. |
- Hansson, Ingrid, et al.
(författare)
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Knowledge gaps in control of Campylobacter for prevention of campylobacteriosis
- 2018
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Ingår i: Transboundary and Emerging Diseases. - : Hindawi Limited. - 1865-1674 .- 1865-1682. ; 65, s. 30-48
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Tidskriftsartikel (refereegranskat)abstract
- Campylobacteriosis is an important, worldwide public health problem with numerous socio-economic impacts. Since 2015, approximately 230,000 cases have been reported annually in Europe. In the United States, Australia and New Zealand, campylobacteriosis is the most commonly reported disease. Poultry and poultry products are considered important sources of human infections. Poultry meat can become contaminated with Campylobacter during slaughter if live chickens are intestinal carriers. Campylobacter spp. can be transferred from animals to humans through consumption and handling of contaminated food products, with fresh chicken meat being the most commonly implicated food type. Regarding food-borne disease, the most important Campylobacter species are Campylobacter jejuni and Campylobacter coli. In humans, clinical signs of campylobacteriosis include diarrhoea, abdominal pain, fever, headache, nausea and vomiting. Most cases of campylobacteriosis are sporadic and self-limiting, but there are post-infection complications, for example, Guillain-Barres syndrome. This review summarizes an analysis undertaken by the DISCONTOOLS group of experts on campylobacteriosis. Gaps were identified in: (i) knowledge of true number of infected humans; (ii) mechanisms of pathogenicity to induce infection in humans; (iii) training to prevent transfer of Campylobacter from raw to ready-to-eat food; (iv) development of effective vaccines; (v) understanding transmission routes to broiler flocks; (vi) knowledge of bacteriocins, bacteriophages and antimicrobial peptides as preventive therapies; (vii) ration formulation as an effective preventive measure at a farm level; (viii) development of kits for rapid detection and quantification of Campylobacter in animals and food products; and (ix) development of more effective antimicrobials for treatment of humans infected with Campylobacter. Some of these gaps are relevant worldwide, whereas others are more related to problems encountered with Campylobacter in industrialized countries.
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| 8. |
- Johansson, Håkan, 1972-, et al.
(författare)
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Characterization of Campylobacter spp. isolated from wild birds in the Antarctic and Sub-Antarctic
- 2018
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 13:11
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Tidskriftsartikel (refereegranskat)abstract
- A lack of knowledge of naturally occurring pathogens is limiting our ability to use the Antarctic to study the impact human-mediated introduction of infectious microorganisms have on this relatively uncontaminated environment. As no large-scale coordinated effort to remedy this lack of knowledge has taken place, we rely on smaller targeted efforts to both study present microorganisms and monitor the environment for introductions. In one such effort, we isolated Campylobacter species from fecal samples collected from wild birds in the Antarctic Peninsula and the sub-Antarctic island of South Georgia. Indeed, in South Georgia, we found Campylobacter lari and the closely related Campylobacter peloridis, but also distantly related human-associated multilocus sequence types of Campylobacter jejuni. In contrast, in the Antarctic Peninsula, we found C. tart and two closely related species, Campylobacter subantarcticus and Campylobacter volucris, but no signs of human introduction. In fact, our finding of human-associated sequence types of C. jejuni in South Georgia, but not in the Antarctic Peninsula, suggests that efforts to limit the spread of infectious microorganisms to the Antarctic have so far been successful in preventing the introduction of C. jejuni. However, we do not know how it came to South Georgia and whether the same mode of introduction could spread it from there to the Antarctic Peninsula.
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