50 research outputs found

    EFFICIENT PROPAGATION OF ARCHETYPE JC POLYOMAVIRUS IN COS-7 CELLS: EVALUATION OF REARRANGEMENTS WITHIN NCCR STRUCTURAL ORGANIZATION DURING TRANSFECTION.

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    John Cunningham virus (JCPyV) is an ubiqui-tous human pathogen that causes disease in immunocom-promised patients. The JCPyV genome is composed of an early region and a late region, which are physically sepa-rated by the non-coding control region (NCCR). The DNA sequence of the NCCR distinguishes two forms of JCPyV, the designated archetype and the prototype, which resulted from a rearrangement of the archetype sequence. To date, the cell culture systems for propagating JCPyV archetype have been very limited in their availability and robust-ness. Prior to this study, it was demonstrated that JCPyV archetype DNA replicates in COS-7 simian kidney cells expressing SV40 TAg and COS-7 cells expressing HIV-1 Tat. Based on these observations, the present study was conducted to reproduce an in vitro model in COS-7 cells transfected with the JCPyV archetype strain in order to study JCPyV DNA replication and analyze NCCR rear-rangements during the viral life cycle. The efficiency of JCPyV replication was evaluated by quantitative PCR (Q-PCR) and by hemagglutination (HA) assay after trans-fection. In parallel, sequence analysis of JCPyV NCCR was performed. JCPyV efficiently replicated in kidney-derived COS-7 cells, as demonstrated by a progressive increase in viral load and virion particle production after transfection. The archetypal structure of NCCR was maintained during the viral cycle, but two characteristic point mutations were detected 28 days after transfection. This model is a useful tool for analyzing NCCR rearrangements during in vitroreplication in cells that are sites of viral persistence, such as tubular epithelial cells of the kidne

    MALDI-TOF MS Versus VITEK®2: Comparison of Systems for the Identification of Microorganisms Responsible for Bacteremia

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    We evaluated the reliability and accuracy of the combined use of MALDI-TOF MS and classical ID VITEK2 to identify monomicrobial infection in blood culture bottles. In total, 70 consecutive positive blood cultures were included in this study. Positive blood culture bottles were subjected to Gram staining and subcultured on solid media. Isolates grown from such culture media were used for classical ID using VITEK2 system. In parallel, an aliquot was subjected to a lysing-centrifugation method and used for the identification with the MALDI-TOF system. Results evidenced the correct genus and species identification of 91.4 % of microorganisms responsible for bacteremia with an agreement to the species and the genus level. If compared with the standard method VITEK2, our simple and cost-effective sample preparation method would be very useful for rapid identification of microorganisms using blood culture bottles. In fact, the direct method showed rapid and reliable results, especially for the gram-negative group

    Yersinia enterocolitica in Italy. A case of septicemia and abdominal aortic aneurysm infection

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    We report a case of Yersinia enterocolitica septicemia in a 63-year-old patient admitted to the Vascular Surgery Department of Umberto I Hospital (Rome, Italy) for an abdominal aortic aneurysm. The microorganism, recovered from both peripheral blood cultures and aneurysmatic aortic wall specimens, was identified as Y. enterocolitica using matrix-assisted laser desorption ionization-time of flight analysis (MALDI-TOF MS) and 16S rDNA gene sequencing. The isolate responsible for septicemia belonged to the O:9 serotype (biogroup 2). A genetic screening of the isolate made it possible to detect the presence of both the yst and ail genes, encoding a heat-stable enterotoxin and a protein involved in invasion/adherence and serum resistance, respectively. Our case contributes in enriching epidemiological data concerning Y. enterocolitica infections, which might represent severe complications in patients suffering from cardiovascular diseases. Moreover, this study, together with the others, should be regarded as valuable and useful tools for monitoring the rate of infections worldwide

    Eubiosis and dysbiosis: the two sides of the microbiota

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    The microbial ecosystem of the gastrointestinal tract is characterized by a great number of microbial species living in balance by adopting mutualistic strategies. The eubiosis/dysbiosis condition of the gut microbiota strongly influences our healthy and disease status. This review briefly describes microbiota composition and functions, to then focus on eubiosis and dysbiosis status: the two sides of the microbiot

    Impact of clonally-related Burkholderia contaminans strains in two patients attending an Italian cystic fibrosis centre. A case report

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    Background: Burkholderia contaminans is one of the 20 closely related bacterial of the Burkholderia cepacia complex, a group of bacteria that are ubiquitous in the environment and capable of infecting people with cystic fibrosis (CF). This species is an emerging pathogen and it has been widely isolated from CF patients in Argentina, Spain, Portugal, Australia, Canada, USA with a low prevalence in Ireland, France, Russia, Switzerland, Czech Republic, and Italy. This is the first report of B. contaminans affecting two Italian CF patients attending the same CF Centre. We correlate B. contaminans colonisation with lung function decline and co-infection with other clinically relevant CF pathogens. Case presentation: B. contaminans was identified by Multi Locus Sequence Typing in routine sputum analysis of two Caucasian CF women homozygous for Phe508del CFTR mutation. Sequence Type 102 was detected in both strains. It is known that B. contaminans ST102 was isolated both from CF and non-CF patients, with an intercontinental spread across the world. Random Amplified Polymorphic DNA analysis revealed the genetic relatedness between the two strains. We examined their susceptibility to antimicrobial agents, comparing the latter with that recorded for other B. contaminans isolated from different countries. We also described key virulence factors possibly linked with a clinical outcome. Specifically, we attempted to correlate colonization with the incidence of acute exacerbation of symptoms and lung function decline. Conclusions: This case presentation suggests that acquisition of B. contaminans ST102 is not directly associated with a lung function decline. We retain that the presence of other CF pathogens (i.e. MRSA and Trichosporon) along with B. contaminans ST102 might have contributed to the worsening of clinical conditions in our CF patients. The circumstances leading to the establishment of B. contaminans ST102 infections are still unknown. We highlight the importance to proper detect and typing bacteria implicated in CF infection by using molecular techniques

    Klebsiella pneumoniae infections in COVID-19 patients: a two-month retrospective analysis in an Italian hospital

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    Italy has experienced one of the harshest and earliest COVID-19 epidemics, with the number of patients infected that followed, from the end of February up to the end of March, an exponential trend [1]. Between the 6 March and the 2 May, 394 patients were confirmed positive for SARS-CoV-2 at the University Hospital of Rome Policlinico Umberto I (PUI) [2]. At the PUI, 5 COVID-19 devoted wards were organized, including two brand new ICUs, counting 32 dedicated to COVID-19 patients: the first was the old general ICU converted into a dedicated COVID-19 ICU, while the second was created in the spaces of four operating rooms (new ICU). In the period of this study, a total of 80 COVID-19-affected patients were hospitalized in the two ICUs at PUI. Among them, 65 patients were screened for carbapenemase producing Enterobacterales (CPE) colonization (Brillianceâ„¢ CRE medium plates, Oxoid LTD, Basingstoke, UK): 41 out of 47 SARS-CoV-2 patients hospitalised in the old ICU and 24 out of 33 in the new one. Carbapenemase-producing K. pneumoniae were detected in 14/41 patients (34%) only in the old ICU. No CPE were detected from rectal swabs tested in patients hospitalized in the new ICU. In the same period, 11 CPEs were identified from the 39 rectal swabs out of 48 SARS-CoV-2-negative patients (28%) hospitalized in the non-COVID-ICU of the same hospital. Seven COVID-19 patients developed CPE co-infection (5 bronchoalveolar lavages and 2 blood cultures tested positives for carbapenemase-producing K. pneumoniae), while in the non-COVID-19 ICU 7 bloodstream infections (BSIs) also occurred (Table 1). Symptomatic patients were successfully treated with ceftazidime-avibactam

    Increased prevalence of Human Polyomavirus JC viruria in Chronic Inflammatory Rheumatic Diseases patients in treatment with anti-TNF α: a 18 month follow-up study.

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    Chronic inflammatory rheumatic diseases (CIRDs) are immune-mediated pathologies involving joints. To date, TNFα-blocking agents administration is the most promising therapy, although these treatments are associated with an increased Polyomavirus JC (JCPyV) reactivation, the etiological agent of the Progressive Multifocal Leukoencephalopathy (PML). The aim of this study was the recruitment and the analysis of a CIRDs cohort in order to investigate a possible correlation between JCPyV presence and the influence of anti-TNF-α agents on viral loads. Blood and urine samples were collected from 34 CIRDs subjects prior the first anti-TNF-α infusion (T0) and after 3 (T3), 6 (T6), 12 (T12), and 18 (T18) months. Results showed persistent JC viruria significantly higher than JC viremia throughout the 18 month follow-up study (p=0.002). In JCPyV positive samples, the non-coding control region (NCCR) was analyzed. Results evidenced archetypal structures (type II-S) in all isolates with the exception of a sequence isolated from a plasma sample, that corresponds to the type II-R found in PML subjects. Finally, the viral protein 1 (VP1) genotyping was performed and results showed the prevalence of the European genotypes 1A, 1B, and 4. Since only few studies have been carried out to understand whether there is a PML risk in CIRDs population infected by JCPyV, this study contributes to enrich literature insight on JCPyV biology in this cluster. Further investigations are necessary in order to recognize the real impact of biologics on JCPyV life cycle and to identify possible and specific viral variants related to increased virulence in CIRDs patient

    Differential Toll like receptor expression in cystic fibrosis patients' airways during rhinovirus infection

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    Objectives: Since an inappropriate and sustained activation of TLRs may contribute to a chronic inflammatory response resulting in detrimental effects in cystic fibrosis (CF) patients, we sought to examine whether HRV infection might alter the respiratory expression of TLRs according to the microbiological status of CF patients. Methods: Respiratory samples were collected from the respiratory tract of CF patients (n = 294) over a period of 12 months. In addition to the usual microbiological investigation, HRV-RNA detection and typing were performed by RT-PCR and sequencing. HRV viral load and TLRs levels were measured by RT-Real Time PCR. Results: HRV-RNA was detected in 80 out of 515 respiratory samples (15.5%) with a similar rate in all age groups (0–10 years, 11–24 years, ≥ 25 years). Patients infected with different HRV A, B and C species exhibited higher levels of TLR2, TLR4 and TLR8 as compared to HRV negative patients. Moreover, the expression level of TLR2, TLR4 and TLR8 correlated with high level of HRV viral load. HRV positive patients co-colonized by Staphylococcus aureus or Pseudomonas aeruginosa showed also enhanced amounts of TLR2 and TLR2/4-mRNAs expression respectively. In the case of presence of both bacteria, TLR2, TLR4, TLR8 and TLR9 levels are elevated in positive HRV patients. Conclusions: TLRs, especially TLR2 and TLR4, increased in HRV positive CF individuals and varies according to the presence of S. aureus, P. aeruginosa and both bacteria

    SARS-CoV-2 Entry Genes Expression in Relation with Interferon Response in Cystic Fibrosis Patients

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    The expression rate of SARS-CoV-2 entry genes, angiotensin-converting enzyme 2 (ACE2), the main viral receptor and the proteases, furin and transmembrane serine protease 2 (TMPRSS2) in cystic fibrosis (CF) individuals is poorly known. Hence, we examined their levels in upper respiratory samples of CF patients (n = 46) and healthy controls (n = 45). Moreover, we sought to understand the interplay of type I interferon (IFN-I) with ACE2, furin and TMPRSS2 by evaluating their gene expression with respect to ISG15, a well-known marker of IFN activation, in upper respiratory samples and after ex vivo IFNβ exposure. Lower ACE2 levels and trends toward the reduction of furin and TMPRSS2 were found in CF patients compared with the healthy controls; decreased ACE2 amounts were also detected in CF individuals with pancreatic insufficiency and in those receiving inhaled antibiotics. Moreover, there was a strong positive correlation between ISG15 and ACE2 levels. However, after ex vivo IFNβ stimulation of nasopharyngeal cells, the truncated isoform (dACE2), recently demonstrated as the IFN stimulated one with respect to the full-length isoform (flACE2), slightly augmented in cells from CF patients whereas in those from healthy donors, dACE2 levels showed variable levels of upregulation. An altered expression of SARS-COV-2 entry genes and a poor responsiveness of dACE2 to IFN-I stimulation might be crucial in the diffusion of SARS-CoV-2 infection in CF
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