Seroprevalence of norovirus genogroup IV antibodies among humans, Italy, 2010-2011.

Noroviruses (NoVs) of genogroup IV (GIV) (Alphatron-like) cause infections in humans and in carnivorous animals such as dogs and cats. We screened an age-stratified collection of serum samples from 535 humans in Italy, using virus-like particles of genotypes GIV.1, circulating in humans, and GIV.2, identified in animals, in ELISA, in order to investigate the prevalence of GIV NoV-specific IgG antibodies. Antibodies specific for both genotypes were detected, ranging from a prevalence of 6.6% to 44.8% for GIV.1 and from 6.8% to 15.1% for GIV.2 among different age groups. These data are consistent with a higher prevalence of GIV.1 strains in the human population. Analysis of antibodies against GIV.2 suggests zoonotic transmission of animal NoVs, likely attributable to interaction between humans and domestic pets. This finding, and recent documentation of human transmission of NoVs to dogs, indicate the possibility of an evolutionary relationship between human and animal NoVs.

Effects of neonatal corticosterone and environmental enrichment on retinal ERK1/2 and CREB phosphorylation in adult mice.

Exposure to Stimulating Environments (SE) during development may improve neuroplasticity in central nervous system, protect against neurotoxic damage, and promote neuronal recovery in adult life. While biochemical mechanisms of SE-promoted neuronal plasticity are well known in the brain, much less is known on the signaling cascade governing plasticity and neuroprotection in the retina. In order to investigate if in the retina signaling molecules involved in neuronal plasticity are affected by SE, neonatal CD-1 mice were exposed to moderate corticosterone levels (NC), supplemented through maternal milk during the first postnatal week, or to environmental enrichment (EE) conditions (physical and social stimuli) from early adolescence. Our results showed that both NC and EE increased the phosphorylation level of Extracellularly Regulated Kinase 1/2 (ERK1/2) and cAMP response element-binding protein (CREB) in the adult retinal tissue. Furthermore, we observed that activated ERK1/2 was restricted to Müller cells, while pCREB was mostly present in the nuclei of retinal neurons. Neither NC, nor EE modified the expression of GFAP, a marker of Müller cells activation. In conclusion our results indicate that both NC and EE activate ERK1/2 and CREB in the retina and provide a biochemical background for the neuroprotective activity exerted by SE against retinal damage. Furthermore, they support the role of Müller glia as a key cell determinant of retinal neuroplasticity.

Genetic heterogeneity of bovine noroviruses in Italy.

By screening 104 faecal samples from asymptomatic calves in Italy, bovine norovirus RNA was detected with a prevalence rate of 10.5 % (11/104). A continuous sequence spanning the RdRp region and the 5' end of the capsid gene was generated for 7 of the 11 strains. Upon phylogenetic analysis, five strains were grouped with GIII.2 Newbury2-like viruses, and one strain was grouped with GIII.1 Jena-like noroviruses. Interestingly, one strain (80TE/IT) was genetically related to the GIII.1/Jena/80/De in the RdRp but resembled the GIII.2/Newbury2/76/UK in the capsid gene, suggesting a recombination event occurring in the ORF1/ORF2 junction region.

Molecular detection of Aichi virus in raw sewage in Italy.

Aichi virus (AiV) is suspected to play a role in viral gastroenteritis in humans. In this study, we assessed the presence of AiV in untreated influent sewage samples collected at four wastewater treatment plants in central Italy. AiV was detected in 6 (12.5 %) of the 48 specimens and in all plants. All of the Italian strains showed the highest nucleotide and amino acid sequence identity to genotype B AiV detected recently in Asia, especially in China.

Seroprevalence of St-Valerien-like caliciviruses in Italian swine.

St-Valérien-like viruses are newly recognized porcine caliciviruses recently detected in North America and Europe. In this study, baculovirus-expressed virus-like particles of the St-Valérien strain 25A/ITA were generated and used for the development of an antibody-detection ELISA kit to assess the seroprevalence of these novel caliciviruses in swine. Antibodies specific for St-Valérien-like virus were detected in 63 (10.3 %) of 614 serum samples tested with titres ranging from 1 : 50 (28.6 %) to 1 : 800 (40.7 %). These results indicate that St-Valérien-like infections are common among domestic pigs, italy.

Molecular detection of bovine kobuviruses in Italy.

Faecal samples obtained from either asymptomatic or diarrhoeic calves in Italy were screened for bovine kobuviruses (BKVs) using specific primers. BKV RNA was detected in 4.9 % of the samples, with higher positivity rates in diarrhoeic calves (5.3 %) than in asymptomatic animals (4.8 %), although the difference was not statistically significant. Upon sequence analysis, all of the Italian viruses formed a tight group along with BKV-like sequences previously detected in Thailand and Japan.

Analysis of Synchronous and Asynchronous In Vitro Infections with Homologous Murine Norovirus Strains Reveals Time-Dependent Viral Interference Effects.

Viral recombination is a key mechanism in the evolution and diversity of noroviruses. In vivo, synchronous single-cell coinfection by multiple viruses, the ultimate prerequisite to viral recombination, is likely to be a rare event and delayed secondary infections are a more probable occurrence. Here, we determine the effect of a temporal separation of in vitro infections with the two homologous murine norovirus strains MNV-1 WU20 and CW1 on the composition of nascent viral populations. WU20 and CW1 were either synchronously inoculated onto murine macrophage cell monolayers (coinfection) or asynchronously applied (superinfection with varying titres of CW1 at half-hour to 24-h delays). Then, 24 h after initial co-or superinfection, quantification of genomic copy numbers and discriminative screening of plaque picked infectious progeny viruses demonstrated a time-dependent predominance of primary infecting WU20 in the majority of viral progenies. Our results indicate that a time interval from one to two hours onwards between two consecutive norovirus infections allows for the establishment of a barrier that reduces or prevents superinfection.

In vitro inactivation of feline calicivirus (FCV) by chemical disinfectants: resistance variation among field strains.

Several commercial products commonly used for disinfection against feline calicivirus (FCV) have been validated using the vaccine strain F9. However, little information is available regarding the resistance of field strains of FCV to chemical inactivation. In this study, disinfection experiments were performed either on two laboratory-adapted strains or on seven field isolates using three alcohol mixtures and one containing a chlorine compound. For each biocide tested, considerable variability was found among the strains in their susceptibility to inactivation, demonstrating that the effectiveness of disinfection depends not only on the type of chemical compound and exposure time, but also on the FCV strain.

Detection of hepatitis E virus in slaughtered pigs in Italy.

The stools of slaughtered pigs were screened for hepatitis E virus (HEV). HEV RNA was detected in 7.3% of the samples. HEV strains were characterized as genotype 3 subtype c, a cluster previously not described in Italy. These findings provide evidence that slaughterhouse workers may be exposed to HEV infection.

Publisher Correction: Mice repeatedly exposed to Group-A ß-Haemolytic Streptococcus show perseverative behaviors, impaired sensorimotor gating, and immune activation in rostral diencephalon.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Bovine noroviruses: A missing component of calf diarrhoea diagnosis.

Noroviruses are RNA viruses that belong to the Genus Norovirus, Family Caliciviridae, and infect human beings and several animal species, including cattle. Bovine norovirus infections have been detected in cattle of a range of different ages throughout the world. Currently there is no suitable cell culture system for these viruses and information on their pathogenesis is limited. Molecular and serological tests have been developed, but are complicated by the high genetic and antigenic diversity of bovine noroviruses. Bovine noroviruses can be detected frequently in faecal samples of diarrhoeic calves, either alone or in association with other common enteric pathogens, suggesting a role for these viruses in the aetiology of calf enteritis.

Interaction between the endocannabinoid and serotonergic system in the exhibition of head twitch response in four mouse strains.

More than 10 % of children during school years suffer from a transient tic disorder, and 1 % has a particular type of tic disorder known as Tourette syndrome. At present, there is no available treatment that can improve tics without considerable side effects. Recent evidence indicates that tetrahydrocannabinol (THC), the principal psychoactive component of cannabis, reduced in mice the head twitch responses, a tic pharmacologically induced by the selective serotonin 5-HT2 receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI). THC has some considerable side effects that render its use problematic. In this view, cyclohexyl-carbamic acid 3'-carbamoyl-biphenyl-3-yl ester (URB597), an indirect cannabinoid agonist that enhances endogenous anandamide levels, can constitute a valid alternative to the use of direct CB1 receptor agonists. We investigated whether URB597 may reduce the exhibition of DOI-induced head twitch responses in mice. Moreover, to address whether the effects of URB597 on DOI-induced behavioral response constitute a general phenomenon, we evaluated four (ABH, C57BL/6N, SJL/J, CD-1) mouse strains. These strains have been selected in order to represent an ample spectrum of genetic background and phenotypic variation. Predictably, DOI induced consistent tic-like behaviors in all mice. While URB597 exerted slight sedation in C57BN/6L mice, this cannabinoid agonist remarkably mitigated the exhibition of DOI-induced head twitch in all strains. Present data may disclose novel avenues for the pharmacological treatment of tic disorders.

Mice repeatedly exposed to Group-A ß-Haemolytic Streptococcus show perseverative behaviors, impaired sensorimotor gating, and immune activation in rostral diencephalon.

Repeated exposure to Group-A ß-Haemolytic Streptococcus (GAS) may constitute a vulnerability factor in the onset and course of pediatric motor disturbances. GAS infections/colonization can stimulate the production of antibodies, which may cross the blood brain barrier, target selected brain areas (e.g. basal ganglia), and exacerbate motor alterations. Here, we exposed developing SJL male mice to four injections with a GAS homogenate and evaluated the following domains: motor coordination; general locomotion; repetitive behaviors; perseverative responses; and sensorimotor gating (pre-pulse inhibition, PPI). To demonstrate that behavioral changes were associated with immune-mediated brain alterations, we analyzed, in selected brain areas, the presence of infiltrates and microglial activation (immunohistochemistry), monoamines (HPLC), and brain metabolites (in vivo Magnetic Resonance Spectroscopy). GAS-exposed mice showed increased repetitive and perseverative behaviors, impaired PPI, and reduced concentrations of serotonin in prefrontal cortex, a brain area linked to the behavioral domains investigated, wherein they also showed remarkable elevations in lactate. Active inflammatory processes were substantiated by the observation of infiltrates and microglial activation in the white matter of the anterior diencephalon. These data support the hypothesis that repeated GAS exposure may elicit inflammatory responses in brain areas involved in motor control and perseverative behavior, and result in phenotypic abnormalities.

A behavioural test battery to investigate tic-like symptoms, stereotypies, attentional capabilities, and spontaneous locomotion in different mouse strains.

The preclinical study of human disorders associated with comorbidities and for which the aetiology is still unclear may substantially benefit from multi-strain studies conducted in mice. The latter can help isolating experimental populations (strains) exhibiting distinct facets in the parameters isomorphic to the symptoms of a given disorder. Through a reverse-translation approach, multi-strain studies can inform both natural predisposing factors and environmental modulators. Thus, mouse strains selected for a particular trait may be leveraged to generate hypothesis-driven studies aimed at clarifying the potential role played by the environment in modulating the exhibition of the symptoms of interest. Tourette's syndrome (TS) constitutes a paradigmatic example whereby: it is characterized by a core symptom (tics) often associated with comorbidities (attention-deficit-hyperactivity and obsessive-compulsive symptoms); it has a clear genetic origin though specific genes are, as yet, unidentified; its course (exacerbations and remissions) is under the influence of environmental factors. Based on these considerations, we tested four mouse strains (ABH, C57, CD1, and SJL) - varying along a plethora of behavioural, neurochemical, and immunological parameters - on a test battery tailored to address the following domains: tics (through the i.p. administration of the selective 5-HT2 receptor agonist DOI, 5mg/kg); locomotion (spontaneous locomotion in the home-cage); perseverative responding in an attentional set shifting task; and behavioural stereotypies in response to a single amphetamine (10mg/kg, i.p.) injection. Present data demonstrate that while ABH and SJL mice respectively exhibit selective increments in amphetamine-induced sniffing behaviour and DOI-induced tic-like behaviours, C57 and CD1 mice show a distinct phenotype, compared to other strains, in several parameters.

Prenatal corticosterone and adolescent URB597 administration modulate emotionality and CB1 receptor expression in mice.

RATIONALE: The central endocannabinoid system (eCB system) sustains the activity of the hypothalamus-pituitary-adrenal (HPA) axis in mediating individual emotional responses. Deviation in maturational trajectories of these two physiological systems, may persistently adjust individual behavioral phenotype. OBJECTIVE: We investigated, in outbred CD1 male mice, whether exposure to prenatal stress may influence short- and long-term emotional and neurochemical responses to a pharmacological stimulation of the eCB system during adolescence. METHODS: To mimic prenatal stress, pregnant mice were supplemented with corticosterone in the drinking water (33.3 mg/l); their adolescent male offspring received daily injections of the fatty acid amide hydrolase inhibitor, URB597 (0.4 mg/kg), in order to enhance eCB signaling. Mice were then tested for: locomotor activity during adolescence and locomotor activity, anxiogenic, and anhedonic profiles in adulthood. We analyzed the expression of CB1 receptors (CB1Rs) in prefrontal cortex, hippocampus, striatum, and cerebellum in adulthood. RESULTS: Corticosterone administration (PC group) resulted, in adolescence, in a reduction in body weight and locomotion, while in adulthood, in increased anxiety-related behavior and reduced CB1Rs expression in cerebellum. URB597 exposure reduced locomotor activity and increased anhedonia in adulthood. CB1Rs were up-regulated in striatum and hippocampus and down-regulated in the cerebellum. PC-URB597 mice failed to show reductions in locomotion; exhibited increased risk assessment behavior; and showed reduced CB1Rs expression within the prefrontal cortex. CONCLUSIONS: Present results provide support to the hypothesis that precocious manipulations mapping onto the HPA axis and eCB system may persistently adjust individual emotional responses and eCB system plasticity.

The Directive 2010/63/EU on animal experimentation may skew the conclusions of pharmacological and behavioural studies.

All laboratory animals shall be provided some form of environmental enrichment (EE) in the nearest future (Directive 2010/63/EU). Displacing standard housing with EE entails the possibility that data obtained under traditional housing may be reconsidered. Specifically, while EE often contrasts the abnormalities of consolidated disease models, it also indirectly demonstrates that their validity depends on housing conditions. We mimicked a situation in which the consequences of a novel pharmacological compound were addressed before and after the adoption of the Directive. We sub-chronically exposed standard- or EE-reared adolescent CD1 mice (postnatal days 23-33) to the synthetic compound JWH-018, and evaluated its short- and long-term potential cannabinoid properties on: weight gain, locomotion, analgesia, motor coordination, body temperature, brain metabolism ((1)H MRI/MRS), anxiety- and depressive-related behaviours. While several parameters are modulated by JWH-018 independently of housing, other effects are environmentally mediated. The transition from standard housing to EE shall be carefully monitored.

Canine kobuviruses in diarrhoeic dogs in Italy.

Canine kobuviruses (CaKVs) are newly recognized picornaviruses recently detected in dogs in the US. By molecular analysis of the whole genome, CaKV that appeared genetically closest to the murine kobuvirus (MuKV) and to the human Aichi virus (AiV), may be classified in the Kobuvirus genus as new genotype (CaKV type 1) within the species Aichivirus A. To date, there are no information on the epidemiology of these novel viruses in other continents. In this study, by screening a collection of 256 dog fecal samples either from diarrhoeic or asymptomatic animals, CaKV was identified in six specimens with an overall prevalence of 2.34% (6/256). All the positive dogs presented diarrhea and were found to be infected by CaKV alone or in mixed infections with canine coronavirus (CCoV) and/or canine parvovirus type 2 (CPV-2). By molecular analysis of the partial 3D gene, all the strains detected displayed a close relatedness with the CaKVs recently identified in the US. This study provides evidence that CaKVs circulate in diarrhoeic dogs in Italy and are not geographically restricted to the North American continent, where they were first signaled.

Molecular detection of porcine kobuviruses in Italian swine.

In this study, fecal specimens (n=260) collected from Italian healthy pigs aged between 6 and 10 months were screened by RT-PCR using generic kobuvirus primers. Porcine kobuviruses (PKVs) were detected in 3.85% of the samples tested. Based on the analysis of the partial 3D gene, the Italian sequences identified here were more closely related to PKVs previously identified in Japan, Thailand, Korea, China and Brazil than to the European PKVs recently detected in Hungary and in the Netherlands.

Behavioral responses to acute and sub-chronic administration of the synthetic cannabinoid JWH-018 in adult mice prenatally exposed to corticosterone.

Recent data indicate that both availability and consumption of synthetic and natural psychoactive substances, marketed under the name of "legal highs", has increased. Among them, the aminoalkylindole-derivative JWH-018 is widely distributed due to its capability of binding the cannabinoid receptors CB1 and CB2 thereby mimicking the effects of classical drug agonists. To address whether the behavioral effects of the synthetic compound JWH-018 are similar to those induced by classical cannabinoid agonists, we investigated, in outbred CD1 mice, the consequences of its acute and sub-chronic administration (0, 0.03, 0.1, or 0.3 mg/kg, IP) at the level of body temperature, pain perception, general locomotion, and anxiety. In order to address whether the exposure to precocious stressors-modified individual reactivity to this psychoactive substance, we also investigated its effects in adult mice previously exposed to prenatal stress in the form of corticosterone supplementation in the maternal drinking water (33 or 100 mg/L). In the absence of major effects on motor coordination, JWH-018-reduced body temperature, locomotion and pain reactivity, and increased indices of anxiety. Prenatal corticosterone administration-reduced individual sensitivity to the effects of JWH-018 administration in all the aforementioned parameters. This altered response is not due to variations in JWH-018 metabolism. Present data support the hypothesis that precocious stress may affect, in the long-term, the functional status, and reactivity of the endocannabinoid system.