Comparison of FTD SARS-CoV-2 Assay and RealStar RT-PCR kit 1.0 for the detection of SARS-CoV-2.

The aim of the study was to evaluate the clinical performance of FTD SARS-CoV-2 compared to the RealStar RT-PCR kit 1.0. The analysis of 100 nasopharyngeal swabs showed an overall agreement of 88 %. The positive percentage agreement was 85.6 % and the negative percentage agreement was 91 %. In conclusion we observed a substantial agreement among the two methods, with discrepancies mainly observed in specimens with relatively low amount of viral RNA.

SARS-CoV-2 diagnostics in the virology laboratory of a University Hospital in Rome during the lockdown period.

Italy was one of the most affected nations by coronavirus disease 2019 outside China. The infections, initially limited to Northern Italy, spread to all other Italian regions. This study aims to provide a snapshot of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) epidemiology based on a single-center laboratory experience in Rome. The study retrospectively included 6565 subjects tested for SARS-CoV-2 at the Laboratory of Virology of Sapienza University Hospital in Rome from 6 March to 4 May. A total of 9995 clinical specimens were analyzed, including nasopharyngeal swabs, bronchoalveolar lavage fluids, gargle lavages, stools, pleural fluids, and cerebrospinal fluids. Positivity to SARS-CoV-2 was detected in 8% (527/6565) of individuals, increased with age, and was higher in male patients (P < .001). The number of new confirmed cases reached a peak on 18 March and then decreased. The virus was detected in respiratory samples, in stool and in pleural fluids, while none of gargle lavage or cerebrospinal fluid samples gave a positive result. This analysis allowed to gather comprehensive information on SARS-CoV-2 epidemiology in our area, highlighting positivity variations over time and in different sex and age group and the need for a continuous surveillance of the infection, mostly because the pandemic evolution remains unknown.

Detection of SARS-COV N2 Gene: Very low amounts of viral RNA or false positive?

BACKGROUND: The detection of a low amount of viral RNA is crucial to identify a SARS-CoV-2 positive individual harboring a low level of virus, especially during the convalescent period. However, the detection of one gene at high Cycle threshold (Ct) has to be interpreted with caution. In this study we address this specific issue and report our real-life experience. STUDY DESIGN: A total of 1639 nasopharyngeal swabs (NPS) were analyzed with Xpert® Xpress SARS-CoV-2. Positive samples showing high Ct values (Ct>35) were concentrated by centrifugation and re-tested with Cepheid or other methods (RealStar SARS-CoV2 RT-PCR, Altona Diagnostics; GeneFinder COVID-19 Plus RealAmp Kit, Elitech). RESULTS: 1599 (97.5%) negative samples, 36 (2.3%) positive samples and 4 (0.2%) presumptive positive samples were detected. In 17 out of 36 positive patients, very low viral RNA copies were suspected since positivity was detected at high Ct. We confirmed positivity for patients who showed both E and N genes detected and for patients with only N detected but with Ct <39. On the contrary, samples with only gene N detected with Ct values >39 were found negative. NPS taken 24 hours after the first collection confirmed the negativity of the 12 samples. Clinical data sustained these results since only 2 of these 12 patients showed COVID-19-like symptoms. CONCLUSIONS: These data support our consideration that detection of the N2 gene at high Ct needs to be interpreted with caution, suggesting that collaboration between virologists and clinicians is important for better understanding of results.

Redondovirus DNA in human respiratory samples.

BACKGROUND: Redondovirus (ReDoV) is a recently discovered circular, Rep-encoding single-stranded DNA (CRESS-DNA) virus in humans. Its pathogenesis and clinical associations are still completely unknown. METHODS: The presence of ReDoV DNA was investigated in biological specimens of 543 Italian subjects by in-house developed PCR assays. RESULTS: The overall ReDoV prevalence was about 4% (23 of 543 samples). The virus was detected in 22 of 209 (11 %) respiratory samples. One stool sample was also ReDoV positive. Viral DNA was not found in blood samples from immunocompetent and immunosuppressed subjects and cerebrospinal fluids from patients with neurological diseases. Genomic nucleotide differences were detected among the ReDoV isolates by sequencing a 582-nucleotide fragment of the capsid gene of the viral genome. CONCLUSIONS: The results demonstrate that ReDoV is mainly present in the respiratory tract of infected people. Further investigations are needed to reveal possible clinical implications of this new CRESS-DNA virus in humans.

Seroprevalence of group B Coxsackieviruses: Retrospective study in an Italian population.

Group B Coxsackieviruses (CVB) include six serotypes (B1-6) responsible for a wide range of clinical diseases. Since no recent seroepidemiologic data are available in Italy, the study aim was to investigate CVB seroprevalence in a wide Italian population. The study retrospectively included 2459 subjects referring to a large academic hospital in Rome (Italy) in the period 2004-2016. Seroprevalence rates and neutralizing antibodies (nAb) titers were evaluated in relation to years of observation and subjects' characteristics. Positivity for at least one serotype was detected in 69.1% of individuals. Overall, the prevalent serotype was B4, followed by B3 (33.3%), B5 (26.2%), B1 (12.7%), B2 (11.0%), and B6 (1.7%). For B2, a significant decrease in seroprevalence over years was observed. Positivity to at least one virus was 25.2% in children aged 0 to 2 years, but significantly increased in preschool (3-5 years) (50.3%) and school (6-10 years) children (70.4%). Higher nAb responses for B3 and B4 were observed in children aged 3 to 5 years. A high overall CVB prevalence was found. Type-specific variations in prevalence over time probably reflect the fluctuations in circulation typical of Enteroviruses. Children are at greater risk for CVB infection given the high number of seronegative subjects aged 0 to 10 years.

Low prevalence of Gemycircularvirus DNA in immunocompetent and immunocompromised subjects.

Gemycircularviruses (GemyCV) are a vast array of viruses belonging to the Genomoviridae family. Prevalence and pathogenesis in humans are still poorly understood. Different GemyCV species were investigated in 661 Italian subjects by species-specific PCRs. Only the GemyCV-C1c species was detected, with low prevalence and the highest rate in HIV immunosuppressed patients.

Interferon lambda4 polymorphism is not associated with human papillomavirus infection outcome.

Interferon (IFN) lambdas are important specific components of the mucosal innate immune response. The IFN lambda 4 (IFNL4) dinucleotide polymorphism (ΔG/TT) determines the IFN lambdas and related Interferon-stimulated genes activation, in HCV and other chronic infections. Our group first reported that IFN Lambda response was impaired in high-risk Human Papillomavirus (HPV) cervical infections and in precancerous lesions. Accordingly, we sought to evaluate the possible role of the IFNL4 polymorphism in determining HPV infection outcome. The ΔG/TT alleles were not differently distributed in 221 women with high- or low-risk HPV infection, with HPV infection clearance or persistence, and with abnormal cytology.

Enhancement of viniferin production in Vitis vinifera L. cv. Alphonse Lavallée Cell suspensions by low-energy ultrasound alone and in combination with methyl jasmonate.

This study examined for the first time the effect of low-energy ultrasound (US), used alone or in combination with methyl jasmonate (MeJA), on viniferin production in cell cultures of Vitis vinifera L. cv Alphonse Lavallée. Cell suspensions were exposed for 2 min to US (power 30, 60, and 90 mW cm(-3)). The highest viniferin production was obtained at 30 mW cm(-3). When sonication was performed twice, the effect on viniferin production was negligible, whereas triple sonication slightly increased production. US treatment at 30 mW cm(-3) for 5 min decreased viniferin production and induced cellular death. The combined use of MeJA and US (2 min) increased the production of δ-viniferin, the dominant stilbene, more than each elicitor used alone. These results suggest that low-energy US, alone and in combination with MeJA, can act as a physical elicitor to stimulate viniferin production in V. vinifera cell cultures.