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Dive into the research topics where Silvia Ortu is active.

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Featured researches published by Silvia Ortu.


The Journal of Pediatrics | 2008

Performance of QuantiFERON-TB Testing in a Tuberculosis Outbreak at a Primary School

Paola Molicotti; Alessandra Bua; Graziella Mela; Paolina Olmeo; Renzo Delogu; Silvia Ortu; Leonardo Antonio Sechi; Stefania Anna Lucia Zanetti

This study compared the effectiveness of the QuantiFERON-TB Gold (QFT) assay with the Mantoux tuberculin skin test to detect Mycobacterium tuberculosis infection in 29 children during a school outbreak of tuberculosis. Of the 21 children with M. tuberculosis infection, 11 had a radiograph suggestive of the infection. The QFT assay was positive in all 21 of the children, and the Mantoux test was negative at first testing in 2 children (1 of whom was the sentinel case). The findings demonstrate that the QFT test is extremely useful in accurately identifying infected and uninfected children, permitting rapid intervention.


Acta Veterinaria Hungarica | 2008

Identification of mycobacterial infections in wild boars in Northern Sardinia, Italy

Stefania Anna Lucia Zanetti; Alessandra Bua; Paola Molicotti; Giovanni Delogu; Antonio Mura; Silvia Ortu; Leonardo Antonio Sechi

During a six-month period a region of Northern Sardinia was monitored to check the presence of mycobacterial infections in wild boars. Forty-eight serum and 229 biopsy samples were collected from different animals and examined by both traditional diagnostic techniques (culture, bacterioscopic and molecular tests) and enzyme-linked immunosorbent assay (ELISA). The latter was used to determine the antibody response against both methylated and nonmethylated Heparin-Binding Haemagglutinin (HBHA) protein. Nine mycobacterial strains were isolated: three M. avium ssp. paratuberculosis (Map), three M. avium, one M. interjectum and two M. scrofulaceum strains. By PCR, only one animal was positive for M. bovis, whereas 10 animals were positive for Map. Out of the 48 sera tested, 19 showed a good humoral response to methylated HBHA and 17 to nonmethylated HBHA. Our data provide new information on the prevalence of mycobacterial infection among wild boars in Northern Sardinia and suggest that a more effective program should be developed to monitor mycobacterial infections in the wild animal population.


Annals of Clinical Microbiology and Antimicrobials | 2006

In vitro activities of antimycobacterial agents against Mycobacterium avium subsp. paratuberculosis linked to Crohn's Disease and Paratuberculosis

Stefania Anna Lucia Zanetti; Paola Molicotti; Sara Cannas; Silvia Ortu; Niyaz Ahmed; Leonardo Antonio Sechi

Crohns disease, a human disease similar to paratuberculosis in animals is the most painful and devastating disease that may involve infection with M. avium subsp. paratuberculosis (MAP), different genetic polymorphisms and an immune dysregulation syndrome. Treatment of Crohns disease is most commonly based on 5-aminosalicylic acid (5-ASA) compounds, corticosteroids, and immunosuppressive agents. Recently, biological therapies using monoclonal antibodies against inflammatory cytokines have shown some positive results. However, all these therapies treat the symptoms not the cause of the disease.


Journal of The European Academy of Dermatology and Venereology | 2005

Cutaneous Mycobacterium chelonae I infection extending in the lower extremities in a renal transplanted patient

Pasquale Ena; Leonardo Antonio Sechi; Paola Molicotti; Silvia Ortu; Stefania Anna Lucia Zanetti

This study shows the case of one 50-year-old man patient infected by cutaneous Mycobacterium chelonae I.


Journal of Medical Virology | 2017

DNMT1 modulation in Chronic Hepatitis B patients and hypothetic influence on Mitochondrial DNA methylation status during long-term Nucleo(t)side Analogues Therapy.

Giordano Madeddu; Silvia Ortu; Giovanni Garrucciu; Ivana Maida; M. Melis; Alberto A. Muredda; Maria Stella Mura; Sergio Babudieri

Inhibition of viral replication is the most important goal in patients with Hepatitis B virus chronic infection (CHB). Currently, five oral nucleo(t)side analogs (NAs), including Lamivudine, Adefovir, Telbivudine, Entecavir, and Tenofovir, have been approved for treatment. The widespread use of NAs has also been linked with a progressive growth of unlikely anomaly attributable to mitochondrial dysfunctions, not previously recognized. Here, we explore the hypothesis that NAs may cause persistent epigenetic changes during prolonged NAs therapy in CHB patients. We obtained peripheral blood mononuclear cells (PBMC) from whole blood samples of consecutive patients with chronic HBV infection, 18 receiving NAs and 20 untreated patients. All patients were Caucasian and Italians. Epigenetic analysis was performed by Bisulphite sequencing PCR to search the existence of methylated cytosine residues in the Light (L)‐strands of mitochondrial DNA control region (D‐loop). Gene expression analysis of DNA methyltransferases 1 was performed by a quantitative relative Real‐Time Polymerase Chain Reaction (PCR). DNMT1 expression was significantly (P < 000001) higher in NA treated patients (4.09, IQR 3.52‐5.15) when compared with HBV naives (0.61, IQR 0.34‐0.82). Besides, DNMT1 expression was significantly correlated with NA therapy duration (Spearman Rho = 0.67; P < 0.05). Furthermore, NA therapy duration was the only significant predictor of DNMT1 expression at multivariate analysis (Beta = 0.95, P < 0.0000001). Bisulphite PCR sequencing showed that methylation of cytosine residues occurred in a higher percentage in patients treated with NAs in comparison with untreated patients and healthy controls. Our data showed a DNMT1 overexpression significantly correlated to NA therapy duration and an higher regional mtDNA hypermethylation. This might suggest an epigenetic alteration that could be involved in one of the possible mechanisms of mitochondrial gene regulation during NAs therapy.


International Dairy Journal | 2007

Identification and functional characterization of Lactobacillus strains isolated from milk and Gioddu, a traditional Sardinian fermented milk

Silvia Ortu; Giovanna E. Felis; Marta Marzotto; Antonella Deriu; Paola Molicotti; Leonardo Antonio Sechi; Franco Dellaglio; Stefania Anna Lucia Zanetti


Vaccine | 2006

Immunization with DNA vaccines encoding different mycobacterial antigens elicits a Th1 type immune response in lambs and protects against Mycobacterium avium subspecies paratuberculosis infection

Leonardo Antonio Sechi; Laura Mara; Pietro Cappai; Richard Frothingam; Silvia Ortu; Antonio Leoni; Niyaz Ahmed; Stefania Anna Lucia Zanetti


New Microbiologica | 2006

In vitro efficacy of Linezolid on clinical strains of Mycobacterium tuberculosis and other mycobacteria.

Paola Molicotti; Silvia Ortu; Alessandra Bua; Sara Cannas; Leonardo Antonio Sechi; Stefania Anna Lucia Zanetti


New Microbiologica | 2006

Rapid detection and identification of Mycobacterium tuberculosis by Real Time PCR and Bactec 960 MIGT

Silvia Ortu; Paola Molicotti; Leonardo Antonio Sechi; Pietro Pirina; Franca Saba; Cono Vertuccio; Antonella Deriu; Ivana Maida; Maria Stella Mura; Stefania Anna Lucia Zanetti


Infection, Genetics and Evolution | 2007

Genome and transcriptome scale portrait of sigma factors in Mycobacterium avium subsp. paratuberculosis.

Leonardo Antonio Sechi; Giovanna E. Felis; Niyaz Ahmed; Daniela Paccagnini; Donatella Usai; Silvia Ortu; Paola Molicotti; Stefania Anna Lucia Zanetti

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Niyaz Ahmed

Centre for DNA Fingerprinting and Diagnostics

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Giovanni Delogu

Catholic University of the Sacred Heart

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Giovanni Fadda

Catholic University of the Sacred Heart

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