Bioaccumulation Dynamic by Crassostrea gigas Oysters of Viruses That Are Proposed as Surrogates for Enteric Virus Contamination in Environmental Samples.

Oysters are filter-feeders and retain sewage-derived pathogens in their organs or tissues. Since most enteric viruses involved in outbreaks cannot grow in cell culture, studies using viral surrogate models are essential. Some species are proposed as surrogates for enteric viruses in environmental samples, including in bivalve mollusk samples, such as murine norovirus type 1 (MNV-1) and somatic (as φX) or F-specific coliphages (as MS2) bacteriophages. This study evaluated the tissue distribution of viral surrogates for enteric virus contamination after their bioaccumulation by Crassostrea gigas. Oyster tissues were analyzed for the distribution of viral surrogates (MNV-1, φX-174, and MS2) in digestive tissue (DT), gills (GL), and mantle (MT) after 4, 6, and 24 h of experimental bioaccumulation. MNV-1 had higher counts at 6 h in DT (1.2 × 103 PFU/g), followed by GL and MT (9.5 × 102 and 3.8 × 102 PFU/g, respectively). The bacteriophage φX-174 had a higher concentration in the MT at 4 and 6 h (3.0 × 102 PFU/g, in both) and MS2 in the GL after 24 h (2.2 × 102 PFU/g). The bioaccumulation pattern of MNV-1 by oysters was similar to the other enteric viruses (more in DT), while that of phages followed distinct patterns from these. Since the MNV-1 is bioaccumulated by C. gigas and is adapted to grow in cell culture, it is an important tool for bioaccumulation and viral inactivation tests in oysters. Although bacteriophage bioaccumulation was not similar to enteric viruses, they can be indicated for viral bioaccumulation analysis, analyzing MT and GL, since they do not bioaccumulate in DT.

Lactoferrin affects rhinovirus B-14 entry into H1-HeLa cells.

Lactoferrin is part of the innate immune system, with antiviral activity against numerous DNA and RNA viruses. Rhinoviruses, the leading cause of the common cold, are associated with exacerbation of respiratory illnesses such as asthma. Here, we explored the effect of bovine lactoferrin (BLf) on RV-B14 infectivity. Using different assays, we show that the effect of BLf is strongest during adhesion of the virus to the cell and entry. Tracking the internalisation of BLf and virus revealed a degree of colocalisation, although their interaction was only confirmed in vitro using empty viral particles, indicating a possible additional influence of BLf on other infection steps.

Human coronavirus alone or in co-infection with rhinovirus C is a risk factor for severe respiratory disease and admission to the pediatric intensive care unit: A one-year study in Southeast Brazil.

OBJECTIVE: We aimed to assess the profile of respiratory viruses in young children hospitalized for acute lower respiratory tract infection (ALRI) and its association with disease severity, defined as need for pediatric intensive care unit (PICU) admission. DESIGN: Prospective observational cohort study. SETTING: A tertiary-care university hospital in Brazil. PATIENTS: Children younger than three years attending the pediatric emergency room with ALRI who were admitted to the hospital. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Nasopharyngeal aspirates were collected from patients from June 1st, 2008 to May 31st, 2009within the first 48 hours of hospitalization. Nasopharyngeal aspirates were tested for 17humanrespiratory viruses by molecular and immunofluorescence based assays. Simple and multiple log-binomial regression models were constructed to assess associations of virus type with a need for PICU admission. Age, prematurity, the presence of an underlying disease and congenital heart disease were covariates. Nasopharyngeal aspirates were positive for at least one virus in 236 patients. Rhinoviruses were detected in 85.6% of samples, with a preponderance of rhinovirus C (RV-C) (61.9%). Respiratory syncytial virus was detected in 59.8% and human coronavirus (HCoV) in 11% of the samples. Co-detections of two to five viruses were found in 78% of the patients. The detection of HCoV alone (adjusted relative risk (RR) 2.18; 95% CI 1.15-4.15) or in co-infection with RV-C (adjusted RR 2.37; 95% CI 1.23-4.58) was independently associated with PICU admission. CONCLUSIONS: The detection of HCoV alone or in co-infection with RV-C was independently associated with PICU admission in young children hospitalized for ALRI.

Presence of enteric viruses, bioaccumulation and stability in Anomalocardia brasiliana clams (Gmelin, 1791).

Bivalve mollusks are filter feeders and may accumulate human pathogens in their tissues. Many studies demonstrated human diseases associated with bivalve consumption, especially oysters. Anomalocardia brasiliana clams are distributed along the Brazilian coastal area and are an exotic ingredient for some typical dishes in Brazil. Even though there are several reports describing the contamination of oysters and mussels with human pathogens, there is a lack of studies reporting contamination of A. brasiliana with human pathogens. An evaluation of natural microbiological contamination in A. brasiliana samples over a period of 18months (November 2014 to April 2016) showed that the bacteria indices were in accordance with Brazilian regulations (E. coli<230MPN and Salmonella sp. absent in 25g of meat). However, the enteric viruses evaluated were detected throughout the analysis period, with the highest result for the hepatitis A virus (HAV); followed by Rotavirus-A (RVA); Human Adenovirus (HAdV) and Norovirus GI (NoV GI). The bioaccumulation of enteric viruses by A. brasiliana during a period of 24h was performed using NoV GI and GII, HAV, RVA and HAdV as models. Interestingly the mollusk demonstrated different uptake behaviors in relation to these viruses throughout the time period. NoV GI was the most adsorbed virus after 24h. HAV concentration was <1% at 3h, but it increased to <10% at 8h, remaining unchanged until 12h, and decreasing to <3% at 24h; HAdV reached its highest concentration at 12h, being released by the animals and lowering to <3% at 24h. RVA bioaccumulation was unstable over time, reaching its highest values after 24h (<5%); NoV GII bioaccumulation remained <1%. Thermal inactivation of HAdV-2 in A. brasiliana was also evaluated. After the usual gentle cooking procedure using different times (0, 1, 1.5, 3 and 5mins), viral infectivity was evaluated using ICC-et-RT-qPCR. The temperature inside the DT remained <80°C over time and after 5min of cooking the HAdV reached a decay of 90% (1 log10). The results showed a real warn to the consumers that can be exposed to infectious human viruses if they eat these clams improperly cooked. HAV was the most detected virus in these animals, which may lead to outbreaks. A. brasiliana exhibited distinct behavior in NoV GI bioaccumulation and persistence, pointing to the need for further studies about the cellular ligands used by these viruses to become attached to these clams.

Toll-like receptor 3 (TLR3) and the development of type 1 diabetes mellitus.

Type 1 diabetes mellitus (T1DM) is a chronic, progressive autoimmune disease characterized by metabolic decompensation often leading to dehydration and ketoacidosis. Viral agents seem to play an important role in triggering the autoimmune destruction that leads to the development of T1DM. Among several viral strains investigated so far, the enterovirus family has been consistently associated with the onset of T1DM in humans. One of the mediators of viral damage is the double-stranded RNA (dsRNA) generated during replication and transcription of viral RNA and DNA. The Toll-like receptor 3 (TLR3) gene codes for an endoplasmic receptor of the pattern-recognition receptors (PRRs) family that recognizes dsRNA, plays an important role in the innate immune response triggered by viral infection. Binding of dsRNA to the TLR3 triggers the release of proinflammatory cytokines, such as interferons, which exhibit potent antiviral action; thus, protecting uninfected cells and inducing apoptosis of infected ones. Therefore, the TLR3 gene is a good candidate for the development of T1DM. Within this context, the objective of the present review was to address the role of the TLR3 gene in the development of T1DM.

Toll-like receptor 3 (TLR3) and the development of type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) is a chronic, progressive autoimmune disease characterized by metabolic decompensation often leading to dehydration and ketoacidosis. Viral agents seem to play an important role in triggering the autoimmune destruction that leads to the development of T1DM. Among several viral strains investigated so far, the enterovirus family has been consistently associated with the onset of T1DM in humans. One of the mediators of viral damage is the double-stranded RNA (dsRNA) generated during replication and transcription of viral RNA and DNA. The Toll-like receptor 3 (TLR3) gene codes for an endoplasmic receptor of the pattern-recognition receptors (PRRs) family that recognizes dsRNA, plays an important role in the innate immune response triggered by viral infection. Binding of dsRNA to the TLR3 triggers the release of proinflammatory cytokines, such as interferons, which exhibit potent antiviral action; thus, protecting uninfected cells and inducing apoptosis of infected ones. Therefore, the TLR3 gene is a good candidate for the development of T1DM. Within this context, the objective of the present review was to address the role of the TLR3 gene in the development of T1DM. Arch Endocrinol Metab. 2015;59(1):4-12.

Evidence for nonpoliovirus enterovirus multiplication in L20B cells.

Stool specimens collected from 1 515 healthy children following a mass vaccination campaign in Cuba were tested for poliovirus excretion using L20B cell lines. In spite of the selectivity of this cell line for polioviruses (117/129; 90.7%) some other nonpolio enteroviruses (12/129: 9.3%), such as coxsackie A virus types 4, 8 and 10, can grow in L20B cells.

[Silent circulation of poliovirus demonstrated by interference against non-polio enterovirus]. / Circulación silenciosa de poliovirus demostrada por interferencia a los enterovirus no polio.

Fecal samples were weekly obtained from children under 3 years of age to isolate non-polio poliovirus and enterovirus and to expand the knowledge on circulation of vaccine-derived viruses during mass campaigns. The steady vaccination schedules allow the circulation of these viruses for long periods of time. The interference of non-polio enterovirus by vaccine poliovirus was demonstrated in children. However, the low percentages of non-polio enterovirus did not show significant differences whereas these differences were significant in high percentages of vaccine poliovirus isolated in children under one year-old in comparison with those of 1 and 2 years of age. Based on this contradiction, mathematical calculations estimated the silent circulation of poliovirus that in turn made it possible to draw simulated curves. The results were later confirmed in another research work by using immunological methods.

Ultrastructural and immunocytochemical study on the infection of enterovirus 71 (EV 71) in rhabdomyosarcoma (RD) cells.

Rhabdomyosarcoma monolayers were inoculated with enterovirus 71 (EV 71) at 73 degrees C, sampled at intervals during the replicative cycle, and examined in thin sections by electron microscopy, using routine and immunoelectronmicroscopy with polyclonal antibodies against EV 71. The location of EV 71 or its precursors was followed during the viral replicative cycle. The earliest samples (3 h postinoculation) showed a cell shape change, from elongated to rounded. At 6 h postinoculation, the presence of early virus-induced vesicles developing within the cytoplasm was pointed out, although no virus particles were observed at these stages. At 12 and 20 h postinoculation, virus particles appeared in the cytoplasm. They were found free or in clusters in the cytoplasmic matrix, between the virus-induced vesicles. EV 71 particles were also occasionally observed in the form of paracrystalline arrays situated in the vesiculated areas. The immunolabel (gold beads) was found, initially, over dense cytoplasmic areas and in more advanced process at the vesiculated area and over the virus particles. Therefore the main cellular alterations observed in this infection were the shape change of the cell and the appearance of electron-dense areas (viroplasm) and smooth walled vesicles which are probably the site of the virus replication.

[Epidemic neuropathy. An etiopathogenetic hypothesis]. / Neuropatía epidémica. Hipótesis etiopatogénica.

An etiopathogenic hypothesis is explained taking into consideration the most significant results of the research performed on neuropathy as well as the latest knowledge about the infections produced by Enterovirus. The hypothesis allows to make a logical interpretation of these results; however, the new aspects included make it controversial in the light of the present knowledge to pathogeny by Enterovirus. Further research is needed to confirm this hypothesis.

[Mechanism of Enterovirus participation in epidemic neuropathy. Physiopathological hypothesis]. / Mecanismo de participación de los Enterovirus en la neuropatía epidémica. Hipótesis fisiopatológicas.

During the epidemic neuropathy occurred in Cuba from 1992 to 1993, viral isolations antigenically connected with Coxsackie viruses were obtained from the cerebrospinal fluid of patients. Virological, epidemiological, toxicologic, nutritional, immunological and histopathological investigations were made. Though the disease was related to toxic and nutritional factors, it has been impossible to identify the cause of the epidemic. Taking into consideration the results of the different investigations, we have formulated a comprehensive and multifactorial hypothesis to explain the physiopathological mechanism of the participation of the isolated viruses as mediators in a process of autoimmunity of the pathogeny of the disease.

Enteroviruses as a possible cause of myocarditis, pericarditis and dilated cardiomyopathy in Belém, Brazil

We attempted to assess the role of enteroviruses in the etiology of myocarditis (MC), pericarditis (PC) and dilated cardiomyopathy (DCM) among 15 in-patients at a public hospital in Belém, Brazil, from November 1992 to December 1993. We obtained stool specimens and throat swabs from each patient (particularly acute cases) and, when possible, acute and convalescent serum samples for both isolation and serological procedures. MC, PC and DCM ocurred in 10, 2 and 3 patients, respectively, mostly in the 0- to 10- year age group. Neutralizing antibody seroconversions were detected as follows: one for Coxsackievirus (Cox) B2 in one patient suffering from MC, and two for Cox B4, in patients with DCM and MC. In addition, antibody titers of 1/320 against Cox B2 and Cox B4 were noted in two other patients, one suffering from PC and the other presenting MC. Isolation of echovirus (ECHO) serotype 1 was recorded ina a patient with MC, without either seroconversion or high antibody levels for Cox B 1 to 6. These results indicate that enteroviruses may be involved in the etiology of MC, PC and DCM in the Amazon region.

[Inhibition of the multiplication of a Coxsackie A9 strain isolated from a patient with epidemic neuropathy by the interferons alfa and gamma]. / Inhibición de la multiplicación de la cepa de Coxsackie A9 aislada de un paciente con neuropatía epidémica frente a los interferones alfa y gamma.

We present the results of the in vitro action of alpha and gamma interferons and of Intacglobin and Igegam against the 47/93/IPK (Coxsackie A9) strain isolated from the cerebrospinal fluid of a patient with epidemic neuropathy. The in vitro studies showed that the two interferons inhibited the replication of this agent; they also showed the presence of antibodies to it in the Intacglobin and Igegam. The results attained demonstrated that the use of these compounds could be effective for the treatment of this entity.