Respiratory Route Research Articles

Rapid control of pandemic H1N1 influenza by targeting NKT-cells.

Swine influenza A viruses (IAV) are a major cause of respiratory disease in pigs and humans. Currently approved anti-influenza therapies directly target the virus, but these approaches are losing effectiveness as new viral strains quickly develop drug resistance. To over come this challenge, there is an urgent need for more effective antiviral drugs. Here we tested the anti-influenza efficacy of the invariant natural killer T (NKT) cell superagonist, α-galactosylceramide (α-GalCer), which stimulates a wide array of anti-viral immune responses. We show that intranasal but not systemic administration of α-GalCer to piglets infected with pandemic A/California/04/2009 (CA04) H1N1 IAV ameliorated disease symptoms and resulted in the restoration of weight gain to the level of uninfected pigs. Correspondingly, viral titers in the upper-and lower-respiratory tract were reduced only in piglets that had received intranasal α-GalCer. Most significantly, lung inflammation as a consequence of virus persistence was largely prevented when NKT-cells were targeted via the respiratory route. Thus, targeting mucosal NKT-cells may provide a novel and potent platform for improving the course of disease in swine infected with seasonal and pandemic influenza viruses, and leads to the suggestion that this may also be true in humans and therefore deserves further study.

Homing pigeons as a biomonitor for atmospheric PAHs and PCBs in Guangzhou, a megacity in South China

The occurrence of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyl (PCBs) in urban atmosphere in Guangzhou, China were assessed using homing pigeons as a biomonitor. Contaminant concentrations in lung were significantly higher than those in liver and fat, indicating chemical uptake was mainly through respiratory route. Tricyclic PAHs and low chlorinated PCBs dominated composition of PAHs and PCBs in homing pigeons, similar as their composition in local atmosphere. Different age-dependent bioaccumulation patterns were noted for PAHs and PCBs. For 1-year old homing pigeons, higher levels of PAHs and PCBs in lung and liver tissues were probably ascribed to more intense flying than 5- and 10-year groups. Fat concentrations of PCBs were greater in aged pigeons than 1-year old pigeons, but PAH concentrations in fat slightly decreased in aged pigeons because of relatively fast biotransformation. Overall, homing pigeons could serve as a suitable biomonitor for urban atmospheric contaminants in coastal cities. CapsuleHoming pigeons could serve as a good biomonitor for PAHs and PCBs in urban atmosphere, yet different biotransformation potential of the chemicals caused different bioaccumulation patterns in pigeon fat.

Francisella Tularensis Clades B.FTN002-00 and B.13 Are Associated With Distinct Pathology in the European Brown Hare (Lepus europaeus).

Tularemia is a severe disease caused by Francisella tularensis This bacterium has a major pathogenic potential in countless animal species as well as in humans. Despite the relatively significant body of literature available on this microorganism, many questions are still open concerning its biological cycle in the environment, the pathology and pathogenesis of the disease, the possible routes of infection in animals, and the pathologic and ecological relevance of the distinct phylogenetic clusters of F. tularensis In order to address these questions, we have thoroughly characterized the pathology and microbiology of terminally ill European brown hares (Lepus europaeus) infected with F. tularensis subsp. holarctica, collected in Switzerland from 2012 to 2014. F tularensis isolates were typed by defining their phylogenetic clusters. We showed that the pathology associated with F. tularensis subsp. holarctica belonging to the clade B.FTNF002-00 is different from that previously reported to be associated with the clade B.13. In particular, strains of the clade B.FTNF002-00 were almost invariably associated with splenitis and hepatitis and not with the polyserositis affecting pleura, pericardium, and kidney reported in the literature for infections caused by the clade B.13. We describe findings suggesting that the ports of entry for the bacteria might be the respiratory and digestive routes.

Genomic and functional analysis of the host response to acute simian varicella infection in the lung.

Varicella Zoster Virus (VZV) is the causative agent of varicella and herpes zoster. Although it is well established that VZV is transmitted via the respiratory route, the host-pathogen interactions during acute VZV infection in the lungs remain poorly understood due to limited access to clinical samples. To address these gaps in our knowledge, we leveraged a nonhuman primate model of VZV infection where rhesus macaques are intrabronchially challenged with the closely related Simian Varicella Virus (SVV). Acute infection is characterized by immune infiltration of the lung airways, a significant up-regulation of genes involved in antiviral-immunity, and a down-regulation of genes involved in lung development. This is followed by a decrease in viral loads and increased expression of genes associated with cell cycle and tissue repair. These data provide the first characterization of the host response required to control varicella virus replication in the lung and provide insight into mechanisms by which VZV infection can cause lung injury in an immune competent host.

Lipid core peptide/poly(lactic-co-glycolic acid) as a highly potent intranasal vaccine delivery system against Group A streptococcus

Rheumatic heart disease represents a leading cause of mortality caused by Group A Streptococcus (GAS) infections transmitted through the respiratory route. Although GAS infections can be treated with antibiotics these are often inadequate. An efficacious GAS vaccine holds more promise, with intranasal vaccination especially attractive, as it mimics the natural route of infections and should be able to induce mucosal IgA and systemic IgG immunity. Nanoparticles were prepared by either encapsulating or coating lipopeptide-based vaccine candidate (LCP-1) on the surface of poly(lactic-co-glycolic acid) (PLGA). In vitro study showed that encapsulation of LCP-1 vaccine into nanoparticles improved uptake and maturations of antigen-presenting cells. The immunogenicity of lipopeptide incorporated PLGA-based nanoparticles was compared with peptides co-administered with mucosal adjuvant cholera toxin B in mice upon intranasal administration. Higher levels of J14-specific salivary mucosal IgA and systemic antibody IgG titres were observed for groups immunized with encapsulated LCP-1 compared to LCP-1 coated nanoparticles or free LCP-1. Systemic antibodies obtained from LCP-1 encapsulated PLGA NPs inhibited the growth of bacteria in six different GAS strains. Our results show that PLGA-based lipopeptide delivery is a promising approach for rational design of a simple, effective and patient friendly intranasal GAS vaccine resulting in mucosal IgA response.

Respiratory and oral vaccination improves protection conferred by the live vaccine strain against pneumonic tularemia in the rabbit model.

Tularemia is a severe, zoonotic disease caused by a gram-negative bacterium, Francisella tularensis We have previously shown that rabbits are a good model of human pneumonic tularemia when exposed to aerosols containing a virulent, type A strain, SCHU S4. We further demonstrated that the live vaccine strain (LVS), an attenuated type B strain, extended time to death when given by scarification. Oral or aerosol vaccination has been previously shown in humans to offer superior protection to parenteral vaccination against respiratory tularemia challenge. Both oral and aerosol vaccination with LVS were well tolerated in the rabbit with only minimal fever and no weight loss after inoculation. Plasma antibody titers against F. tularensis were higher in rabbits that were vaccinated by either oral or aerosol routes compared to scarification. Thirty days after vaccination, all rabbits were challenged with aerosolized SCHU S4. LVS given by scarification extended time to death compared to mock-vaccinated controls. One orally vaccinated rabbit did survive aerosol challenge, however, only aerosol vaccination extended time to death significantly compared to scarification. These results further demonstrate the utility of the rabbit model of pneumonic tularemia in replicating what has been reported in humans and macaques as well as demonstrating the utility of vaccination by oral and respiratory routes against an aerosol tularemia challenge.

Serological evaluation of Bordetella pertussis infection in adults with prolonged cough

Pertussis is a vaccine-preventable disease that is transmitted from infected to susceptible individuals by respiratory route. Bordetella pertussis infection may occur at any age as neither vaccine nor natural infection induced immunity lasts life-long. This study was planned to demonstrate the serological evidence of infection among adults, to raise awareness among clinicians and to provide data for the development of strategies to protect vulnerable infants. A total of 538 patients (345 female, 193 male) ages between 18-87 years who had a complain of prolonged cough for more than two weeks were included in the study. Anti-pertussis toxin (PT) IgG and anti-filamentous hemagglutinin (FH) IgG levels from single serum samples were measured by an in-house ELISA test which was standardized and shown to be efficient previously. Anti-PT IgG antibody levels of ≥ 100 EU/ml were considered as acute/recent infection with B.pertussis. In our study, 9.7% (52/538) of the patients had high levels of anti-PT IgG (≥ 100 EU/ml) and among those patients 43 (43/52; 82.7%) also had high (≥ 100 EU/ml) anti-FHA IgG levels. There were no statistically significant differences in terms of age, gender, education level, DPT (diphtheria-pertussis-tetanus) vaccination history, smoking history or average daily cigarette consumption (p> 0.05) between the cases with high antibody levels (n= 52). When the symptoms and the presence of cases with high antibody levels were evaluated, it was detected that no one parameter was significantly different from others, except that 24.1% of the cases with inspiratory whooping had high anti-PT levels. There was also no statistically significant difference between high anti-PT levels ≥ 100 EU/ml and the patients with risk factors [smoking (21/200; 10.5%), presence of disease that cause chronic cough and/or drug usage (19/171; %11.1), and whole factors which cause chronic cough (32/306; %10.5)] and without risk factors (p= 0.581; p= 0.357; p= 0.249, respectively). The distribution of anti-PT IgG geometric mean titer (GMT) according to the age groups, was as follows; 32.41 in 18-30 years; 36.28 in 31-50 years; 36.82 in 51-70 years and 31.15 in ≥ 71 years. Our results indicated that B.pertussis infections are also present among adult population with a frequency not to be underestimated (9.7%) and the results also emphasized that since typical whooping cough symptoms may not be seen in adults, pertussis infection should be considered as a differential diagnosis in adults with prolonged cough, even if there are some other underlying factors of cough. The data obtained from this study was also considered to be helpful in the development of adult vaccination policies for the protection of infants who have not completed the vaccination schedule yet.

Measles Virus Host Invasion and Pathogenesis.

Measles virus is a highly contagious negative strand RNA virus that is transmitted via the respiratory route and causes systemic disease in previously unexposed humans and non-human primates. Measles is characterised by fever and skin rash and usually associated with cough, coryza and conjunctivitis. A hallmark of measles is the transient immune suppression, leading to increased susceptibility to opportunistic infections. At the same time, the disease is paradoxically associated with induction of a robust virus-specific immune response, resulting in lifelong immunity to measles. Identification of CD150 and nectin-4 as cellular receptors for measles virus has led to new perspectives on tropism and pathogenesis. In vivo studies in non-human primates have shown that the virus initially infects CD150+ lymphocytes and dendritic cells, both in circulation and in lymphoid tissues, followed by virus transmission to nectin-4 expressing epithelial cells. The abilities of the virus to cause systemic infection, to transmit to numerous new hosts via droplets or aerosols and to suppress the host immune response for several months or even years after infection make measles a remarkable disease. This review briefly highlights current topics in studies of measles virus host invasion and pathogenesis.

Jaagsiekte Sheep Retrovirus Can Reach Peyer's Patches and Mesenteric Lymph Nodes of Lambs Nursed by Infected Mothers.

Ovine pulmonary adenocarcinoma (OPA) is a contagious lung cancer of sheep caused by jaagsiekte sheep retrovirus (JSRV). It is generally accepted that transmission by the respiratory route occurs under natural conditions. However recent studies strongly indicate that JSRV can also be transmitted to lambs perinatally via colostrum and milk (C/M). The aim of this work was to confirm that C/M can transmit JSRV infection to lambs under natural conditions and investigate the initial events associated with this transmission route. We have analyzed the presence of JSRV in C/M samples from 22 naturally infected, asymptomatic ewes throughout a lactation period, and in various tissues collected from a group of 36 of their lambs that were fed naturally. The lambs were euthanized at 12, 24, 48, and 72 hours and at 5 and 10 days after birth. We detected JSRV-provirus by PCR in the somatic C/M cells from 10/22 ewes (45.45%). The virus was also detected in 9/36 lambs (25%). JSRV-infected cells, with lymphoreticular-like morphology, were observed by immunohistochemistry (IHC) and in situ hybridization (ISH) in Peyer's patches (PP) from the small intestine of the youngest lambs and in mesenteric lymph nodes (MLN) from lambs older than 72 hours. The virus was also detected by PCR in white blood cells (WBC) in 2/36 lambs (5.5%). These results confirm colostral transmission of JSRV to lambs under natural conditions. Infected lymphoreticular cells contained in C/M appear to be involved. These cells can cross the intestinal barrier of newborn lambs, reach the MLN and enter into circulation.

The influence of lung surfactant liquid crystalline nanostructures on respiratory drug delivery

The respiratory route increasingly has been used for both local and systemic drug delivery. Although drug is absorbed rapidly after respiratory delivery, the role of lung surfactant in drug delivery is not well understood. The human lung contains only around 15mL of surface lining fluid spread over ∼100m2 surface. The fluid contains lung surfactant at a concentration of 8–24mg/kg/body weight; the lung surfactant which is lipo-protein in nature can form different liquid crystalline nanostructures. After a brief overview of the anatomy of respiratory system, the review has focused on the current understanding of lung surface lining fluid, lung surfactants and their composition and possible self-assembled nanostructures. The role of lung surfactant in drug delivery and drug dissolution has been briefly considered.Lung surfactant may form different liquid crystalline phases which can have an active role in drug delivery. The hypotheses developed in this review focuses on the potential roles of surface epithelial fluid containing liquid crystalline nanostructures in defining the dissolution mechanism and rate. The hypotheses also focus an understanding how liquid crystalline nanostructures can be used to control dissolution rate and how the nanostructures might be changed to influence delivery and induce toxicity.

Fullerenes: Characteristics of the substance, biological effects and occupational exposure levels

Fullerenes are molecules composed of an even number of carbon atoms of a spherical or an ellipsoidal, closed spatial structure. The most common fullerene is the C60 molecule with a spherical structure - a truncated icosahedron, compared to a football. Fullerenes are widely used in the diagnostics and medicine, but also in the electronics and energy industry. Occupational exposure to fullerene may occur during its production. The occupational concentrations of fullerenes reached 0.12-1.2 μ/m3 for nanoparticles fraction (< 100 nm), which may evidence low exposure levels. However, fullerene mostly agglomerates into larger particles. Absorption of fullerene by oral and respiratory routes is low, and it is not absorbed by skin. After intravenous administration, fullerene accumulates mainly in the liver but also in the spleen and the kidneys. In animal experiments there was no irritation or skin sensitization caused by fullerene, and only mild irritation to the eyes. Fullerene induced transient inflammation in the lungs in inhalation studies in rodents. Oral exposure does not lead to major adverse effects. Fullerene was not mutagenic, genotoxic or carcinogenic in experimental research. However, fullerene may cause harmful effects on the mice fetus when administered intraperitoneally or intravenously. Pristine C60 fullerene is characterized by poor absorption and low toxicity, and it does not pose a risk in the occupational environment. The authors of this study are of the opinion that there is no ground for estimating the maximum allowable concentration (NDS) of pristine fullerene C60. Fullerene derivatives, due to different characteristics, require separate analysis in terms of occupational risk assessment. Med Pr 2016;67(3):397-410.

Effect of respiratory vaccine components and route of delivery on weight gain and inflammatory response in suckling beef calves

Two randomized studies of Angus beef calves (n = 110) from 2 Iowa locations were used to determine the effect of vaccine type and route of administration on weight gain and inflammatory response. The first vaccine contained avirulent-live Mannheimia haemolytica (type A1) and Pasteu- rella multocida (type A3), and was administered intranasally (IN group). The second vaccine contained an adjuvanted M. haemolytica (type Al) toxoid and was administered subcutaneously (SC group). Control calves (CON) were given the same volume (2 mL) of sterile saline SC as other calves. At the time of vaccination (day 0), calf body weight (BW) and body temperature (BT) were recorded, and a blood sample was collected for serum haptoglobin analysis. Blood collection and BT measurement were repeated on days 1, 2, and 3 while BW was recorded on days 3 and 21 (location 1) or 24 (location 2) after vaccination. A final BW was taken at weaning at both locations. Changes in BW among calves during the first 3 days after vaccination were not significantly different across treatment groups. At location 1, calves given SC vaccine had a higher average BT compared to IN-vaccinated calves (P &lt; 0.01). Body temperature also tended to be higher in SC-vaccinated calves (P = 0.08) compared to CON calves. At location 2, BT was not different between vaccinated groups, but vaccinated calves had higher BT compared to CON calves (P&lt; 0.01). Over the 21-day trial period at location 1, average daily gain (ADG) in calves given SC vaccine was lower compared to CON calves (P = 0.04). At location 2, ADG was not significantly different among treatments, but IN calves had heavier final weights compared to other treatment groups (P &lt; 0.01). Serum haptoglobin levels were higher for SC calves compared to IN and CON calves on days 1, 2, and 3 following vaccination (P &lt; 0.01). Mean weight gain and ADG from vaccination through weaning tended to be greater (P = 0.06) for IN calves at location 1, but were not different at location 2.

English

With the increased demand for high quality maize seeds, the market absorbs innovations that add speed and reliability in the tests that enable differentiation of potential performance of seed lots. This study aims to evaluate the combination of the physiological tests with the expression of enzymes of respiratory route for differences in vigor levels in lots of hybrid seed corn. The percentage of germination, germination first count, emergence on tray, index of emergency speed, accelerated aging and respiration rate were evaluated by Pettenkoffer and Titulation method. Furthermore, the expression of alpha amylase, alcohol dehydrogenase, malate dehydrogenase and pyruvate decarboxylase was analyzed. With the results, it is determined that the vigor tests analyzed, together with the tests of enzymatic expressions of respiratory route were efficient to detect different levels of force in hybrid seed corn. Lot 1 had higher physiological quality while lot 2 had the lowest vigor compared to the other lots. With the vigor tests and expression of enzymes, it was possible to differentiate the quality of the seeds and therefore it can be recommended as reliable tests for defining the quality of seed lots. Key words: Respiration, enzyme expression, vigor, viability.

The Emergence of Enterovirus-D68

Enterovirus-D68 (EV-D68) is a unique enterovirus, similar to human rhinoviruses, spread via the respiratory route and primarily causing respiratory disease. Increasing clusters of EV-D68 associated respiratory disease have been reported since 2008, with the largest reported outbreak occurring in North America in 2014. Epidemiologic data and biological plausibility support an association of EV-D68 with the neurologic condition, acute flaccid myelitis. Diagnosis requires EV-D68 specific PCR or viral sequencing of respiratory specimens. Treatment consists of supportive care, as there are no currently available effective vaccines or antiviral therapies. Further research is needed to prepare for future EV-D68 outbreaks of respiratory or neurologic disease.

Recombinant Newcastle disease virus expressing H9 HA protects chickens against heterologous avian influenza H9N2 virus challenge

In order to produce an efficient poultry H9 avian influenza vaccine that provides cross-protection against multiple H9 lineages, two Newcastle disease virus (NDV) LaSota vaccine strain recombinant viruses were generated using reverse genetics. The recombinant NDV-H9Con virus expresses a consensus-H9 hemagglutinin (HA) that is designed based on available H9N2 sequences from Chinese and Middle Eastern isolates. The recombinant NDV-H9Chi virus expresses a chimeric-H9 HA in which the H9 ectodomain of A/Guinea Fowl/Hong Kong/WF10/99 was fused with the cytoplasmic and transmembrane domain of the fusion protein (F) of NDV. Both recombinant viruses expressed the inserted HA stably and grew to high titers. An efficacy study in chickens showed that both recombinant viruses were able to provide protection against challenge with a heterologous H9N2 virus. In contrast to the NDV-H9Chi virus, the NDV-H9Con virus induced a higher hemagglutination inhibition titer against both NDV and H9 viruses in immunized birds, and efficiently inhibited virus shedding through the respiratory route. Moreover, sera collected from birds immunized with either NDV-H9Con or NDV-H9Chi were able to cross-neutralize two different lineages of H9N2 viruses, indicating that NDV-H9Con and NDV-H9Chi are promising vaccine candidates that could provide cross-protection among different H9N2 lineage viruses.

Characterization of Immune Responses to an Inactivated Avian Influenza Virus Vaccine Adjuvanted with Nanoparticles Containing CpG ODN.

Avian influenza virus (AIV), a mucosal pathogen, gains entry into host chickens through respiratory and gastrointestinal routes. Most commercial AIV vaccines for poultry consist of inactivated, whole virus with adjuvant, delivered by parenteral administration. Recent advances in vaccine development have led to the application of nanoparticle emulsion delivery systems, such as poly (d,l-lactic-co-glycolic acid) (PLGA) nanoparticles to enhance antigen-specific immune responses. In chickens, the Toll-like receptor 21 ligand, CpG oligodeoxynucleotides (ODNs), have been demonstrated to be immunostimulatory. The objective of this study was to compare the adjuvant potential of CpG ODN 2007 encapsulated in PLGA nanoparticles with nonencapsulated CpG ODN 2007 when combined with a formalin-inactivated H9N2 virus, through intramuscular and aerosol delivery routes. Chickens were vaccinated at days 7 and 21 posthatch for the intramuscular route and at days 7, 21, and 35 for the aerosol route. Antibody-mediated responses were evaluated weekly in sera and lacrimal secretions in specific pathogen-free chickens. The results indicate that nonencapsulated CpG ODN 2007 in inactivated AIV vaccines administered by the intramuscular route generated higher antibody responses compared to the encapsulated CpG ODN 2007 formulation by the same route. Additionally, encapsulated CpG ODN 2007 in AIV vaccines administered by the aerosol route elicited higher mucosal responses compared to nonencapsulated CpG ODN 2007. Future studies may be aimed at evaluating protective immune responses induced with PLGA encapsulation of AIV and adjuvants.

NUMERICAL ANALYSIS OF FLOW CHARACTERISTICS FOR THE NORMAL HUMAN UPPER AIRWAY

Based on the data from the spiral Computerized Tomography (CT) images, three dimensional models consisting of the airway from nasal cavity, pharynx and trachea to triple bifurcation are built. Computational fluid dynamics (CFD) method is applied to study the respiratory air flow dynamics within the upper respiratory tract of human body. The influence of different respiratory routes on airway resistance and within the respiratory air flow characteristics is studied under the respiration of the nose and mouth. The influence of the different respiratory route on the characteristics of airflow and the airway resistance were studied at the work of nasal and oral. When only a small amount of air flow is inhaled and exhaled through the oral, the distribution law of airflow in the airways is similar to that of breathing process only through the nose. With the increase of mouth breathing air flow rate, the airway of the highest airflow velocity and the total pressure drop are reduced. Except for the nasal cavity, where the airway resistance was decreased, the airway resistance of other parts was increased with increasing mouth breathing. When the airflow exchanged with the outside world mainly through mouth, the distribution of airflow in the airways were obviously different, especially in the nose, mouth and throat, which brought the new allocation of the airway resistance and the great reduction of nasal resistance. The airway resistance mainly concentrated in the oral cavity and the following airway. The results of numerical simulation are useful for studying the pathogenesis and diagnosing the diseases related to the anatomical structure and function of upper airway.

Co-housing of Rift Valley Fever Virus Infected Lambs with Immunocompetent or Immunosuppressed Lambs Does Not Result in Virus Transmission.

Rift Valley fever virus (RVFV) is transmitted among susceptible animals by mosquito vectors. Although the virus can be isolated from nasal and oral swabs of infected animals and is known to be highly infectious when administered experimentally via oral or respiratory route, horizontal transmission of the virus is only sporadically reported in literature. We considered that immunosuppression resulting from stressful conditions in the field may increase the susceptibility to horizontally transmitted RVFV. Additionally, we reasoned that horizontal transmission may induce immune responses that could affect the susceptibility of contact-exposed animals to subsequent infection via mosquito vectors. To address these two hypotheses, viremic lambs were brought into contact with sentinel lambs. One group of sentinel lambs was treated with the immunosuppressive synthetic glucocorticosteroid dexamethasone and monitored for signs of disease and presence of virus in the blood and target organs. Another group of contact-exposed sentinel lambs remained untreated for three weeks and was subsequently challenged with RVFV. We found that none of the dexamethasone-treated contact-exposed lambs developed detectable viremia, antibody responses or significant increases in cytokine mRNA levels. Susceptibility of immunocompetent lambs to RVFV infection was not influenced by previous contact-exposure. Our results are discussed in light of previous findings.

Evaluation of the Gastrointestinal Tract as Potential Route of Primary Polyomavirus Infection in Mice

BackgroundDetection of Polyomavirus (PyV) DNA in metropolitan rivers worldwide has led to the suggestion that primary viral infection can occur by the oral route. The aim of this study was to test this notion experimentally.MethodsMouse PyV (MPyV) was used to infect C57BL/6J mice by the nasal or intragastric route. Viral load kinetics was studied 3, 7, 10, 14, 21 and 28 days post-infection (dpi) using quantitative PCR.ResultsFollowing nasal infection, MPyV DNA was readily detected in many organs including lung, heart, aorta, colon, and stool with viral loads in the range of 103–106 copies/mg wet weight that peaked 7–10 dpi. Complete viral clearance occurred in the serum and kidney by 28 dpi, while clearance in other organs was partial with a 10–100 fold decrease in viral load. In contrast, following intragastric infection peak detection of PyV was delayed to 21 dpi, and viral loads were up to 3 logs lower. There was no detectable virus in the heart, colon, or stool.ConclusionsThe intragastric route of MPyV infection is successful, not as efficacious as the respiratory route, and associated with delayed viral dissemination as well as a lower peak MPyV load in individual organs.

High circulation of non-polio enteroviruses among hospitalized children with acute gastroenteritis in Belém, Pará State, Northern Brazil

Enteroviruses are transmitted by fecal-oral and respiratory routes and can be associated with sporadic cases and outbreaks of gastroenteritis. A causative agent in approximately 40% of diarrheal cases still remains undiagnosed. Non-polio enteroviruses were detected in 46 (26%) of 176 diarrhea stool specimens by both real-time RT-PCR (rRT-PCR) and semi-nested RT-PCR assays. This study presents a high circulation of enteroviruses in children with acute gastroenteritis in the City of Belem, Para State, Brazil.