| 1. |
- Kordasti, Shirin, 1975, et al.
(författare)
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Rotavirus infection is not associated with small intestinal fluid secretion in the adult mouse.
- 2006
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Ingår i: Journal of virology. - 0022-538X .- 1098-5514. ; 80:22, s. 11355-61
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Tidskriftsartikel (refereegranskat)abstract
- In contrast to humans, adult but not infant small animals are resistant to rotavirus diarrhea. The pathophysiological mechanism behind this age-restricted diarrhea is currently unresolved, and this question was investigated by studying the secretory state of the small intestines of adult mice infected with rotavirus. Immunohistochemistry and histological examinations revealed that rotavirus (strain EDIM) infects all parts of the small intestines of adult mice, with significant numbers of infected cells in the ilea at 2 and 4 days postinfection. Furthermore, quantitative PCR revealed that 100-fold more viral RNA was produced in the ilea than in the jejuna or duodena of adult mice. In vitro perfusion experiments of the small intestine did not reveal any significant changes in net fluid secretion among mice infected for 3 days or 4 days or in those that were noninfected (37 +/- 9 microl . h(-1) . cm(-1), 22 +/- 13 microl . h(-1) . cm(-1), and 33 +/- 6 microl . h(-1) . cm(-1), respectively) or in transmucosal potential difference (4.0 +/- 0.3 mV versus 3.9 +/- 0.4 mV), a marker for active chloride secretion, between control and rotavirus-infected mice. In vivo experiments also did not show any differences in potential difference between uninfected and infected small intestines. Furthermore, no significant differences in weight between infected and uninfected small intestines were found, nor were any differences in fecal output observed between infected and control mice. Altogether, these data suggest that rotavirus infection is not sufficient to stimulate chloride and water secretion from the small intestines of adult mice.
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| 2. |
- Pant, Neha, et al.
(författare)
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Lactobacilli expressing variable domain of llama heavy-chain antibody fragments (lactobodies) confer protection against rotavirus-induced diarrhea
- 2006
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Ingår i: Journal of Infectious Diseases. - 0022-1899 .- 1537-6613. ; 194:11, s. 1580-1588
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Tidskriftsartikel (refereegranskat)abstract
- Background. Rotavirus-induced diarrhea poses a worldwide medical problem in causing substantial morbidity and mortality among children in developing countries. We therefore developed a system for passive immunotherapy in which recombinant lactobacilli constitutively express neutralizing variable domain of llama heavy-chain (VHH) antibody fragments against rotavirus. Methods. VHH were expressed in Lactobacillus paracasei, in both secreted and cell surface-anchored forms. Electron microscopy was used to investigate the binding efficacy of VHH-expressing lactobacilli. To investigate the in vivo function of VHH-expressing lactobacilli, a mouse pup model of rotavirus infection was used. Results. Efficient binding of the VHH antibody fragments to rotavirus was shown by enzyme-linked immunosorbent assay and scanning electron microscopy. VHH fragments expressed by lactobacilli conferred a significant reduction in infection in cell cultures. When administered orally, lactobacilli-producing surface-expressed VHH markedly shortened disease duration, severity, and viral load in a mouse model of rotavirus-induced diarrhea when administered both fresh and in a freeze-dried form. Conclusions. Transformed lactobacilli may form the basis of a novel form of prophylactic treatment against rotavirus infections and other diarrheal diseases. © 2006 by the Infectious Diseases Society of America. All rights reserved.
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| 3. |
- Bucardo, F, et al.
(författare)
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Mutated G4P[8] rotavirus associated with a nationwide outbreak of gastroenteritis in Nicaragua in 2005
- 2007
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 45:3, s. 990-997
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Tidskriftsartikel (refereegranskat)abstract
- During February and March 2005, one of the largest national recorded outbreaks of severe acute gastroenteritis occurred in Nicaragua, affecting ≥64,000 individuals and causing ≥56 deaths, predominantly in children under 5 years of age. Through a nationwide laboratory-based study, stool samples were collected and investigated for rotavirus. Of 108 stool samples examined, 72 (67%) were positive for rotavirus. While 69% (50/72) of the positive samples were found in children less than 2 years of age, 50% (6/12) of the adult samples were positive. A mutated G4P[8] strain was the most commonly recognized strain (85%), followed by mixed G strains (8%) and G9P[8] (7%) strains. Phylogenetic analysis of the VP7 gene revealed that the G4 strains belonged to the emerging lineage Ic and was distantly related to the ST3 and VA70 G4 strains. Secondary structure predictions of the VP7 G4 protein revealed an insert of an asparagine residue in position 76, which, combined with additional mutations, surprisingly modified two downstream β-sheets at amino acid positions 80 to 85 and 115 to 119. The 2005 G4P[8] strain compared to a G4P[8] strain from 2002 had a substitution of an asparagine residue for threonine (Asn→Thr) at position 96 within antigenic region A, thus eliminating a potential glycosylation site. The mutated G4 virus was introduced in Nicaragua after 2002 and probably emerged from Brazil, Argentina, or Uruguay. Copyright © 2007, American Society for Microbiology. All Rights Reserved.
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| 4. |
- Claesson, Carina, 1970-, et al.
(författare)
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Susceptibility of staphylococci and enterococci to antimicrobial agents at different ward levels in four north European countries
- 2007
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 39:11-12, s. 1002-1012
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Tidskriftsartikel (refereegranskat)abstract
- A multicentre susceptibility study was performed on staphylococci and enterococci isolated from patients at 3 different ward levels: primary care centres (PCCs), general hospital wards (GHWs) and intensive care units (ICUs), in Denmark, Finland, Norway and Sweden. There was a markedly higher incidence of resistance among CoNS in ICUs compared to GHWs and PCCs. Resistance rates were low among S. aureus isolates and no differences were found between the ward levels. Oxacillin resistance was found among 1.6% of S. aureus and 47% of CoNS isolates. 14% of CoNS and 0.9% of S. aureus isolates were glycopeptide intermediate. The prevalence of E. faecium isolates in this study differed significantly between the ward levels with the lowest prevalence found at PCCs. High level gentamicin resistant (HLGR) enterococci occurred in 11-25% of E. faecium and 6-20% of E. faecalis isolates. The HLGR rate was significantly higher among E. faecalis from hospitalized patients (GHWs and ICUs) compared to patients at PCCs. For enterococcal isolates, no other significant differences in antimicrobial resistance were found between the ward levels. All enterococci were teicoplanin susceptible, but decreased susceptibility to vancomycin was found among 2.0% and 0.6% of the E. faecium and E. faecalis isolates, respectively.
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| 5. |
- Istrate, C, et al.
(författare)
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Bone marrow dendritic cells internalize live RF-81 bovine rotavirus and rotavirus-like particles (RF 2/6-GFP-VLP and RF 8*2/6/7-VLP) but are only activated by live bovine rotavirus
- 2007
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 65:6, s. 494-502
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Tidskriftsartikel (refereegranskat)abstract
- Dendritic cells (DC) represent the link between innate and adaptive immunity. They are classified as antigen-presenting cells (APC) and can initiate and modulate the immune response. To investigate the interaction with DCs, live RF-81 bovine rotavirus strain (RFV) and rotavirus-like particles (rota-VLP), RF 2/6-GFP-VLP and rota RF 8*2/6/7-VLP, were added in vitro to murine bone marrow-derived DCs (bmDCs). Live RFV, RF 2/6-GFP-VLP and RF 8*2/6/7-VLP all bound to bmDC and were internalized but only live RFV stimulated phenotypic maturation of the bmDCs as shown by the upregulation of the co-stimulatory molecule CD86. Even though bmDCs internalized RF 2/6-GFP-VLP and RF 8*2/6/7-VLP as efficiently as live RFV, these rota-VLP were not able to activate the cells. Supernatants derived from bmDC cultures treated with live RFV, RF 2/6-GFP-VLP or RF 8*2/6/7-VLP were examined for TNF-α production. At 6, 18 and 24 h post-infection, TNF-α concentrations were significantly increased in cultures treated with live RFV and rota-VLP compared with untreated cultures. In conclusion, this study showed that live RF-81 bovine rotavirus strain was internalized and induced bmDCs activation, whereas both RF 2/6-GFP-VLP and RF 8*2/6/7-VLP were internalized by bmDCs without triggering their activation. © 2007 The Authors.
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| 6. |
- Istrate, Claudia, 2000-, et al.
(författare)
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Parenteral administration of RF 8-2/6/7 rotavirus-like particles in a one-dose regimen induce protective immunity in mice
- 2008
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Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 26:35, s. 4594-4601
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Tidskriftsartikel (refereegranskat)abstract
- Rotavirus virus-like particles (RV-VLPs) represent a novel strategy for development of a rotavirus subunit vaccine. In this study, RF 8-2/6/7-VLPs with rotavirus VP8 protein (amino acid 1-241 of VP4) fused to the amino terminal end of a truncated VP2, were evaluated for their immunogenic and protective properties. A single intramuscular dose of, either 2 or 20 μg, RF 8-2/6/7-VLPs alone or combined with a potent adjuvant poly[di(carboxylatophenoxy)]phosphazene] (PCPP) induced rotavirus-specific serum IgG and IgA, fecal IgG titers that were enhanced 5-90-fold by adjuvant. Passive protective immunity was achieved in offspring to dams vaccinated with 2 and 20 μg RV-VLPs in presence of adjuvant and 20 μg RV-VLP without adjuvant. © 2008 Elsevier Ltd. All rights reserved.
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| 7. |
- Johansson, E., et al.
(författare)
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Amount of maternal rotavirus-specific antibodies influence the outcome of rotavirus vaccination of newborn mice with virus-like particles
- 2008
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Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 26:6, s. 778-785
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Tidskriftsartikel (refereegranskat)abstract
- In presence of low or high levels of rotavirus-specific maternal antibodies, the ability of newborn mice to respond to immunization with rotavirus RF 8*-2/6/7 VLPs, was evaluated. After parenteral vaccination, 100% of offspring born to low-antibody-titer dams developed rotavirus-specific IgG antibodies (n = 7). In contrast, only 25% of offsprings born to high-antibody-titer dams responded to parenteral immunization (n = 12). When comparing parenteral versus oral immunization in offspring to low-antibody-titer dams only 45% responded after oral immunization (n = 6). In conclusion, the response to parenteral immunization was not hampered by the presence of low levels of maternal antibodies induced by a natural infection while oral immunization was impaired. However, high levels of maternal antibodies impaired the response to parenteral immunization. © 2008 Elsevier Ltd. All rights reserved.
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| 8. |
- Kindberg, Elin, 1981-, et al.
(författare)
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A deletion in the chemokine receptor 5 (CCR5) gene is associated with tickborne encephalitis
- 2008
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Ingår i: Journal of Infectious Diseases. - : Oxford University Press (OUP). - 0022-1899 .- 1537-6613. ; 197:2, s. 266-269
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Tidskriftsartikel (refereegranskat)abstract
- Tickborne encephalitis (TBE) virus infections can be asymptomatic or cause moderate to severe injuries of the central nervous system. Why some individuals develop severe disease is unknown, but a role for host genetic factors has been suggested. To investigate whether chemokine receptor CCR5 is associated with TBE, CCR5Δ32 genotyping was performed among Lithuanian patients with TBE (n = 129) or with aseptic meningoencephalitis (n = 76) as well as among control subjects (n = 134). We found individuals homozygous for CCR5Δ32 (P = .026) only among patients with TBE and a higher allele prevalence among patients with TBE compared with the other groups studied. CCR5Δ32 allele prevalence also increased with the clinical severity of disease. © 2007 by the Infectious Diseases Society of America. All rights reserved.
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| 9. |
- Kindberg, Elin, 1981-, et al.
(författare)
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A nonsense mutation (428G→A) in the fucosyltransferase FUT2 gene affects the progression of HIV-1 infection
- 2006
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Ingår i: AIDS. - : Ovid Technologies (Wolters Kluwer Health). - 0269-9370 .- 1473-5571. ; 20:5, s. 685-689
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The human FUT2 gene encodes the α(1,2)fucosyltransferase that determines secretor status. Homozygous for the nonsense mutation are called non-secretors and are unable to express histo-blood group antigens in secretions and on mucosal surfaces. In this study we have investigated the importance of the FUT2 fucosyltransferase activity on the progress of HIV-1 infection. METHODS: Swedish blood donors (n = 276), 15 long-term non-progressors (LTNP) and 19 progressors were genotyped with respect to the nonsense mutation 428G→A in the FUT2 gene. In addition 265/276 blood donors and 19 progressors with rapid or expected progression rate were Δ32 CCR5 genotyped. RESULTS: Of 276 blood donors 218 (79%) were found to be secretor positive (se+), either homozygous (se+/+) wild type (30%) or heterozygous (se+/-) (49%) and 58 (21%) were homozygous non-secretors (se-/-). Five LTNP (33%) were found to be secretor-positive (se+/+, se+/-) and 10 (67%) se-/-. Of the 19 individuals with normal HIV-1 progression 15 (79 %) were found to be secretor positive and four (21%) were non-secretors. No frequency differences were found in the Δ32 CCR5 allele among the groups studied. CONCLUSION: Strong association (P < 0.001) was observed between the nonsense mutation 428G→A in the FUT2 gene and a slow disease progression of HIV-1 infection. © 2006 Lippincott Williams & Wilkins.
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| 10. |
- Kindberg, Elin, 1981-, et al.
(författare)
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Host genetic resistance to symptomatic norovirus (GGII.4) infections in Denmark
- 2007
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 45:8, s. 2720-2
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Tidskriftsartikel (refereegranskat)abstract
- A total of 61 individuals involved in five norovirus outbreaks in Denmark were genotyped at nucleotides 428 and 571 of the FUT2 gene, determining secretor status, i.e., the presence of ABH antigens in secretions and on mucosa. A strong correlation (P = 0.003) was found between the secretor phenotype and symptomatic disease, extending previous knowledge and confirming that nonsense mutations in the FUT2 gene provide protection against symptomatic norovirus (GGII.4) infections. Copyright © 2007, American Society for Microbiology. All Rights Reserved.
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