New potent vaccine adjuvants are desirable for increasing the efficacy of novel vaccine modalities such as DNA and peptides. We therefore tested if syngeneic erythrocytes could serve as delivery vectors for selected HIV peptides and compared the potency of these constructs to immunization with peptides in phosphate buffered saline or in incomplete Freunds adjuvant Immunization of mice with peptides in a low dose (5 ng) coupled to erythrocytes induced a weak immune response in mice. These peptides alone (5 μg) gave no immune responses, while formulating the peptides (50 μg) in IFA induced strong homologous immunity as well as prominent cross reactivity to a related mutant epitope. Thus, vaccine delivery using syngeneic erythrocytes, although attractive for clinical use, might be of limited value due to the low amount of antigen that can be loaded per erythrocyte.

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.

The immune response to HIV-1 virus-like particles (VLPs), presenting a clade A Ugandan gp120, has been evaluated in a mouse model by intra-nasal (i.n.) administration by a VLP + VLP homologous or a DNA + VLP heterologous prime-boost immunization protocol, including a HIV-1 DNA gp160/rev plasmid. Furthermore, the effect of the Eurocine lipid-based mucosal L3 adjuvant on the VLP immunogenicity has been assessed as well. The designed heterologous protocol is able to increase the env-specific humoral and cellular immune response, compared to the homologous protocol, which is to some extent increased by the administration of L3-adjuvanted VLP boosting dose. The anti-gag response is statistically increased in both homologous and heterologous protocols, particularly when the VLP boosting dose is adjuvanted. Immune sera from immunized animals exhibit >50% ex vivo neutralizing activity against heterologous A and B-clade viral isolates. An envelope B-cell epitope mapping shows an enhanced response against V3 epitopes all across the C2-V5 region in the heterologous prime-boost immunization strategy. The induction of humoral immunity at mucosal sites, which represents the main port of entry for the HIV-1 infection, is extremely relevant. In this framework, the DNA-VLP heterologous prime-boost protocol appears a promising preventive vaccine approach which can significantly benefit from specific mucosal adjuvants, as the Eurocine L3. © 2007 Elsevier Ltd. All rights reserved.

Assembly of human immunodeficiency virus type 1 (HIV-1) is directed by the viral core protein Pr55gag. Depending on the cell type, Pr55 gag accumulates either at the plasma membrane or on late endosomes/multivesicular bodies. Intracellular localization of Pr55 gag determines the site of virus assembly, but molecular mechanisms that define cell surface or endosomal targeting of Pr55gag are poorly characterized. We have analyzed targeting of newly synthesized Pr55 gag in HeLa H1 cells by pulse-chase studies and subcellular fractionations. Our results indicated that Pr55gag was inserted into the plasma membrane and, when coexpressed with the viral accessory protein Vpu, Pr55gag remained at the plasma membrane and virions assembled at this site. In contrast, Pr55gag expressed in the absence of Vpu was initially inserted into the plasma membrane, but subsequently endocytosed, and virus assembly was partially shifted to internal membranes. This endocytosis of Pr55gag required the host protein Tsg101. These results identified a previously unknown role for Vpu and Tsg101 as regulators for the endocytic uptake of Pr55gag and suggested that the site of HIV-1 assembly is determined by factors that regulate the endocytosis of Pr55gag. Copyright © 2006, American Society for Microbiology. All Rights Reserved.

More focused research on a mucosal HIV-1 vaccine is needed urgently. An increasing amount of collected data, using heterologous multimodality prime-booster strategies, suggest that an efficient and protective HIV-1 vaccine must generate broad, long-lasting HIV-specific CD8+ cytotoxic T-lymphocyte and neutralizing antibody responses. In the mucosa, these responses would be most effective if a preferential stimulus of HIV-1 neutralizing secretory immunoglobulin A and G were obtained. The attractive property of mucosal immunization is the obtained mucosal and systemic immunity, whereas systemic immunization induces a more limited immunity, predominantly in systemic sites. These objectives will require new vaccine regimens, such as multiclade HIV DNA and protein vaccines (nef, tat, gag and env expressed in DNA plasmids) delivered onto mucosal surfaces with needle-free delivery methods, such as nasal drop, as well as oral and rectal/vaginal delivery, and should merit clinical trials. © 2007 Future Drugs Ltd.

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.

We have explored the Drosophila S2 cell line for expression of Ig molecules isolated as Fab or scFv cDNA from phage-displayed libraries. We present a series of vectors for inducible expression and secretion of human Ig heavy (HC) and light chains (LC), both on separate plasmids and in combination constructs. Both HC (tested as human γ1) and LC (human κ) could be expressed separately and were secreted into the medium, confirming previous reports. When the combination vector carrying both the HC and LC cDNA, as well as when the HC and LC vectors were co-transfected, complete IgG1 was found in the medium. Transient transfection resulted in production levels of 0.5-1 mg/l. Stable cell lines could be established within 2-3 weeks. After 10-12 days of expression from such cell lines, Ig molecules accumulated and the medium contained typically 5-35 mg/l of IgG1. The IgG in these preparations was purified to more than 90% purity on protein G columns. Binding characteristics for IgG of the same clone expressed in S2 cells or mammalian cells were indistinguishable. The main advantages with this system compared to mammalian expression were its robustness and the much faster establishment of stable, high level producing cell lines. © 2006 Elsevier B.V. All rights reserved.

OBJECTIVE: To test the efficacy of an immunoconjugate against HIV-1. DESIGN: A murine monoclonal antibody against the envelope antigen of HIV (P4/D10) was conjugated with the conventional anticancer drug, doxorubicin, and tested against infectious virus and infected cells, both in vitro and in vivo. METHODS: P4/D10 antibody was incubated with free virus (neutralization) or HIV-infected cells (inhibition) and the resulting infection was measured by a p24 capture enzyme-linked immunosorbent assay. In an HIV-1/MuLV murine challenge model, the ability of the conjugate to inhibit infection in vivo was measured. RESULTS: Doxorubicin-conjugated P4/D10 neutralized HIV-1IIIB and eliminated intercellular spread and HIV replication in infected Jurkat cells in vitro. The conjugate also protected mice from challenge with HIV-1IIIB/MuLV at an eightfold lower concentration than needed for free antibody, whereas no effects were observed for comparable doses of free drug or irrelevant conjugate controls. CONCLUSION: This indicates that doxorubicin is concentrated to HIV-infected cells by the P4/D10 antibody, significantly (P = 0.0001) contributing to HIV elimination. This concept could also be adapted to eradicate remaining antigen-expressing T cells in patients treated with antiretroviral therapy. © 2006 Lippincott Williams & Wilkins.

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.

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.

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 μl · h -1 · cm-1, 22 ± 13 μl · h -1 · cm-1, and 33 ± 6 μl · 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. Copyright © 2006, American Society for Microbiology. All Rights Reserved.

Background and aims: The mechanisms underlying intestinal secretion in rotavirus diarrhoea remain to be established. We previously reported that rotavirus evokes intestinal fluid and electrolyte secretion by activation of the enteric nervous system. We now report that antagonists for the 5-hydroxytryptamine 3 receptor (5-HT3) and vasoactive intestinal peptide (VIP) receptor, but not antagonists for 5-hydroxytryptamine 4 receptor or the muscarinic receptor, attenuate rotavirus induced diarrhoea. Methods: Neurotransmitter antagonists were administered to wild-type or neurokinin 1 receptor knockout mice infected with homologous (EDIM) or heterologous (RRV) rotavirus. Results: While RRV infected mice had diarrhoea for 3.3 (0.2) days (95% confidence interval (CI) 3.04-3.56), the 5-HT3 receptor antagonist (granisetron) and the VIP receptor antagonist (4Cl-D-Phe 6,Leu17)-VIP both reduced the total number of days of RRV induced diarrhoea to 2.1 (0.3) (95% CI 1.31-2.9) (p<0.01). EDIM infected mice treated with granisetron had a significantly shorter duration of diarrhoea (5.6 (0.4) days) compared with untreated mice (8.0 (0.4) days, p<0.01). Experiments with neurokinin 1 receptor antagonists suggest that this receptor may possibly be involved in the secretory response to rotavirus. On the other hand, rotavirus diarrhoea was not attenuated in the neurokinin 1 receptor knockout mice. Conclusions: Our results suggest that the neurotransmitters serotonin and VIP are involved in rotavirus diarrhoea, observations that could imply new principles for treatment of this disease with significant global impact.

Following an acute foodborne gastroenteritis outbreak in southern Sweden, stool specimens from five of nine ill patients were found positive for norovirus using reverse transcriptase polymerase chain reaction. Epidemiological data pointed to raspberry cakes as the source of the outbreak. Using a combination of generic and patient-specific primers and novel food analysis methodology (with extraction efficiency control and inhibitor removal), norovirus strains from two different genogroups were directly identified in the contaminated raspberries.

Noroviruses have emerged as a major cause of acute gastroenteritis in humans of all ages. Despite high infectivity of the virus and lack of long-term immunity, volunteer and authentic studies has suggested the existence of inherited protective factors. Recent studies have shown that histo-blood group antigens (HBGAs) and in particular secretor status controlled by the α1,2fucosyltransferase FUT2 gene determine susceptibility to norovirus infections, with nonsecretors (FUT2-/-), representing 20% of Europeans, being highly resistant to symptomatic infections with major strains of norovirus. Moreover, the capsid protein from distinct strains shows different HBGA specificities, suggesting a host-pathogen co-evolution driven by carbohydrate-protein interactions. © 2006.

Background Highly publicised outbreaks of norovirus gastroenteritis in hospitals in the UK and Ireland and cruise ships in the USA sparked speculation about whether this reported activity was unusual. Methods We analysed data collected through a collaborative research and surveillance network of viral gastroenteritis in ten European countries (England and Wales were analysed as one region). We compiled data on total number of outbreaks by month, and compared genetic sequences from the isolated viruses. Data were compared with historic data from a systematic retrospective review of surveillance systems and with a central database of viral sequences. Findings Three regions (England and Wales, Germany, and the Netherlands) had sustained epidemiological and viral characterisation data from 1995 to 2002. In all three, we noted a striking increase in norovirus outbreaks in 2002 that coincided with the detection and emergence of a new predominant norovirus variant of genogroup II4, which had a consistent mutation in the polymerase gene. Eight of nine regions had an annual peak in 2002 and the new genogroup II4 variant was detected in nine countries. Also, the detection of the new variant preceded an atypical spring and summer peak of outbreaks in three countries. Interpretation Our data from ten European countries show a striking increase and unusual seasonal pattern of norovirus gastroenteritis in 2002 that occurred concurrently with the emergence of a novel genetic variant. In addition to showing the added value of an international network for viral gastroenteritis outbreaks, these observations raise questions about the biological properties of the variant and the mechanisms for its rapid dissemination.

The rotavirus genome encodes two glycoproteins, one structural (VP7) and one non-structural (NSP4), both of which mature and remain in the endoplasmic reticulum (ER). While three amino acids in the N terminus have been proposed to function as a retention signal for VP7, no information is yet available on how NSP4 remains associated with the ER. In this study, we have investigated the ER retention motif of NSP4 by producing various C-terminal truncations. Deleting the C terminus by 52 amino acids did not change the intracellular distribution of NSP4, but an additional deletion of 38 amino acids diminished the ER retention and resulted in the expression of NSP4 on the cell surface. Brefeldin A treatment prevented NSP4 from reaching the cell surface, suggesting that C-terminal truncated plasma membrane NSP4 is transported through the normal secretory pathway. On the basis of these results, we propose that the region between amino acids 85 and 123 in the cytoplasmic region of NSP4 are involved in ER retention.

Pre-weaning diarrhoea is a well-known problem in mink farming in Europe, causing morbidity that varies between farms, regions and season. Different causalities for the disease have been proposed, but only most recently has a novel astrovirus been identified as an important risk factor. In this report, the molecular characterization, origin and evolution of this novel astrovirus of mink are discussed. The polyadenylated, positive-stranded RNA genome was sequenced and found to contain 6610 nt, organized into three ORFs and two short UTRs. A ribosomal frameshift sequence links the 5' two ORFs, containing sequence motifs for a serine protease (ORF1a) and an RNA-dependent RNA polymerase (ORF1b). The structural proteins are encoded by ORF2 and, presumably, are expressed as a polyprotein precursor to be cleaved into the mature capsid proteins. These results indicate that mink astrovirus (MiAstV) has all of the features typical of members of the Astroviridae. Phylogenetic analyses revealed that MiAstV is distantly related to established astroviruses, showing less than 67 % similarity at the nucleotide level with its closest relative, ovine astrovirus, and even lower identities at the predicted amino acid level. Nevertheless, sequence analysis of MiAstV isolates from geographically distinct Swedish and Danish farms showed much less diversity. This suggests either the spread in the mink population of a virus that has evolved a long time ago or the recent introduction of an ancient virus into a new host species.

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.

In Mycobacterium tuberculosis (Mtb)-infected individuals cells of the innate immune system accumulate in the spleen and in granulomas, but how this relates to the protection against Mtb or in the pathogenesis is unknown. Mtb is internalized in the lung by phagocytic cells, such as neutrophils (PMNs), dendritic cells (DCs) and macrophages. PMNs undergo accelerated apoptosis after internalization of the bacterium and are subsequently sequestered by neighbouring phagocytes. Removal of aged apoptotic cells is an immunologically silent process and the aim of this study was to clarify the interaction between Mtb-induced apoptotic PMNs and DCs, and evaluate if this interaction induced functional maturation of the DCs. In fact,  Mtb-induced apoptotic PMNs induced DC maturation, whereas exposure to spontaneous apoptotic PMNs had no effect on DCs maturation status. We found that the cell fraction contained almost all stimulatory capacity, suggesting that the cell-cell interaction is crucial for DC activation. Inhibitory studies showed that this cell contact-dependent activation required binding of the PMN Mac-1 (CD11b/CD18) to the DC via DC-SIGN and endocytic activity. Taken together, this study proves that the DCs can distinguish between normal and infected apoptotic PMNs via cellular cross talk, where the DCs can sense the presence of danger on the Mtb-infected PMNs and modulate their response accordingly.

The pathophysiological mechanisms behind rotavirus-induced diarrhoea still remain incomplete. Current views suggest that the non-structural protein 4 (NSP4) of rotavirus and the enteric nervous system (ENS) participate in water secretion and diarrhoea. In the present work the role of nitric oxide (NO) in rotavirus infection and disease has been studied in vitro, mice and humans. Incubation of human intestinal epithelial cells (HT-29) with purified NSP4 but not with infectious virus produced NO2/NO3 accumulation in the incubation media. The NSP4-induced release of NO metabolites occurred within the first minutes after the addition of the toxin. Mice infected with murine rotavirus (strain EDIM) accumulated NO2/NO3 in the urine at the onset for diarrhoea. Following rotavirus infection, inducible nitric oxide synthetase (iNOS) mRNA was upregulated in ileum, but not in duodenum or jejunum of newborn pups within 5 days post-infection. A prospective clinical study including 46 children with acute rotavirus infection and age-matched controls concluded that rotavirus infection stimulates NO production during the course of the disease (P < 0.001). These observations identify NO as an important mediator of host responses during rotavirus infection. © 2006 Wiley-Liss, Inc.

A DNA plasmid encoding human immunodeficiency virus type 1 (HIV-1) env, nef and tat genes was used in mice in a prime-boost immunization regimen with the corresponding recombinant proteins. The genetic immunogen was delivered with a gene gun and the proteins were injected intramuscularly together with the adjuvant AS02A. Immunizations were followed by experimental challenge with pseudotyped HIV-1 subtype A or B virus. In an initial experiment in which animals were challenged four weeks after the final immunization, all single modality and prime-boost vaccinations resulted in a significant level of protection as compared to control animals. There was a trend for DNA-alone immunization yielding the highest protection. In a subsequent study, a late challenge was performed 19 weeks after the final immunization. All groups having received the DNA vaccine, either alone or in combination with adjuvanted protein, exhibited strong protection against HIV replication. The subtype-specific protection against the experimental HIV challenge was significantly stronger than the cross-protection. Cellular and humoral immune responses were assessed during immunization and after challenge, but without clear correlation to protection against HIV replication. The data suggest that either DNA or protein antigens alone provide partial protection against an HIV-1/MuLV challenge and that DNA immunization is essential for achieving very high levels of efficacy in this murine HIV-1 challenge model. While prime-boost combinations were more immunogenic than DNA alone, they did not appear to provide any further enhancement over DNA vaccine mediated efficacy. The DNA immunogen might prime low levels of CD8+ T cells responsible for virus clearance or possibly a yet unidentified mechanism of protection. © 2006 Elsevier Ltd. All rights reserved.

Rotavirus is a major cause of acute gastroenteritis. By examining 1,517 stool samples collected in 2001 and 2002 from Swedish adults with acute diarrhea, rotavirus was found in 3.2%, with the emerging G9P[8] serotype being the one most commonly identified (42.9%). This is the first documentation of G9 infections in adults in Europe. Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Noroviruses (formerly Norwalk-like viruses) are a major cause of acute gastroenteritis worldwide and are associated with a significant number of nosocomial and food-borne outbreaks. In this study we show that the human secretor FUT2 gene, which codes for an a(1,2)-fucosyltransferase synthesizing the H-type 1 antigen in saliva and mucosa, is associated with susceptibility to norovirus infections. Allelic polymorphism characterization at nucleotide 428 for symptomatic (n = 53) and asymptomatic (n = 62) individuals associated with nosocomial and sporadic norovirus outbreaks revealed that homozygous nonsense mutation (428G→A) in FUT2 segregated with complete resistance for the disease. Of all symptomatic individuals, 49% were homozygous (SeSe) and 51% heterozygous (Sese428) secretors, and none were secretor negative (Se428Se428), in contrast to 20% nonsecretors (se 428se428) among Swedish blood donors (n = 104) (P < 0.0002) and 29% for asymptomatic individuals associated with nosocomial outbreaks (P < 0.00001). Furthermore, saliva from secretor-positive and symptomatic patients but not from secretor-negative and asymptomatic individuals bound the norovirus strain responsible for that particular outbreak. This is the first report showing that the FUT2 nonsecretor (se428se 428) genotype is associated with resistance to nosocomial and sporadic outbreaks with norovirus. Copyright © 2005, American Society for Microbiology. All Rights Reserved.

The incidence of norovirus-associated gastroenteritis and the molecular epidemiology of norovirus strains were studied during three seasons (2000-2001, 2001-2002, and 2002-2003) among patients of all ages, mainly from the Stockholm region in Sweden. A total of 3,252 fecal samples were analyzed by reverse transcription-PCR. The incidences of norovirus infection among adults were 23, 26, and 30% during the three seasons studied and 18,11, and 15% among children 0 to 15 years of age. During the first season, all norovirus strains detected by PCR were typed either by reverse line blot hybridization or nucleotide sequence analysis. During the two successive seasons, a total of 60 norovirus-positive strains from the beginning, peak, and end of the seasons were selected for nucleotide sequence analysis. We identified two dominant noroviras variants over the seasons: a new norovirus variant, recently described as the GGIIb genetic cluster, dominated among children during the first season, and during the following two seasons, a GGII-4 variant dominated. Our data suggest that norovirus infections are common, not only among adults, but also among children, and that some strains may predominantly affect children. Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Penguin blood samples collected at Bird Island, sub-Antarctic South Georgia, and faecal samples taken from penguins at several localities along the Antarctic Peninsula were analysed in order to investigate if influenza A virus is present in penguin populations in the South Atlantic Antarctic region. Serology was performed on the blood samples while the faecal samples were screened by a RT-PCR method directed at the matrix protein gene for determining the presence of influenza A virus. All faecal samples were negative by PCR, but the blood samples gave serologic indications that influenza A virus is present amongst these penguin species, confirming previous studies, although the virus has still not been isolated from any bird in the Antarctic region.