265 research outputs found
Prevalence, Antibiotic-Resistance, and Replicon-Typing of Salmonella Strains among Serovars Mainly Isolated from Food Chain in Marche Region, Italy
Nontyphoidal salmonellosis (NTS) is the second most commonly reported gastrointesti nal infection in humans and an important cause of food-borne outbreaks in Europe. The use of
antimicrobial agents for animals, plants, and food production contributes to the development of
antibiotic-resistant Salmonella strains that are transmissible to humans through food. The aim of
this study was to investigate the presence and the potential dissemination of multidrug-resistant
(MDR) Salmonella strains isolated in the Marche Region (Central Italy) via the food chain. Strains
were isolated from different sources: food, human, food animal/livestock, and the food-processing
environment. Among them, we selected MDR strains to perform their further characterization in
terms of resistance to tetracycline agent, carriage of tet genes, and plasmid profiles. Tetracycline
resistance genes were detected by PCR and plasmid replicons by PCR-based replicon typing (PBRT).
A total of 102 MDR Salmonella strains were selected among the most prevalent serovars: S. Infantis
(n = 36/102), S. Derby (n = 20/102), S. Typhimurium (n = 18/102), and a monophasic variant of S.
Typhimurium (MVST, n = 28/102). Resistance to sulfisoxazole (86%) and tetracycline (81%) were
the most common, followed by ampicillin (76%). FIIS was the most predominant replicon (17%),
followed by FII (11%) and FIB (11%) belonging to the IncF incompatibility group. Concerning the
characterization of tet genes, tetB was the most frequently detected (27/89), followed by tetA (10/89),
tetG (5/89), and tetM (1/89). This study showed the potential risk associated with the MDR Salmonella
strains circulating along the food chain. Hence, epidemiological surveillance supported by molecular
typing could be a very useful tool to prevent transmission of resistant Salmonella from food to humans,
in line with the One Health approach
Extracellular embryo genomic DNA and its potential for genotyping applications
none8noBackground: Preimplantation genetic diagnosis (PGD) currently relies on biopsy of one or few embryo cells. Our aim was to evaluate the embryo extracellular matrices (spent medium and blastocoele fluid) as source of DNA for embryo genotyping. Results/methodology: We first evaluated the amplifiability and the amount of genomic DNA in spent embryo culture media from day 3 (n = 32) and day 5/6 (n = 54). Secondly, we evaluated the possibility to genotype the MTHFR polymorphism C677T from media at day 5/6 (n = 8) and blastocoele fluids (n = 9) by direct sequencing. The C677T polymorphism detection rate was 62.5 and 44.4% in medium and fluid, respectively. Conclusion: A noninvasive approach for embryo genotyping was possible, but still with limitations due to low detection rate and possible allele dropout.openGalluzzi, Luca; Palini, Simone; Destefani, Silvia; Andreoni, Francesca; Primiterra, Mariangela; Diotallevi, Aurora; Bulletti, Carlo; Magnani, MauroGalluzzi, Luca; Palini, Simone; Destefani, Silvia; Andreoni, Francesca; Primiterra, Mariangela; Diotallevi, Aurora; Bulletti, Carlo; Magnani, Maur
T Lymphocyte Subset Counts and Interferon-Gamma Production in Adults and Children with COVID-19: A Narrative Review
Adults and children exhibit a broad range of clinical outcomes from SARS-CoV-2 infection, with minimal to mild symptoms, especially in the pediatric age. However, some children present with a severe hyperinflammatory post-infectious complication named multisystem inflammatory syndrome in children (MIS-C), mainly affecting previously healthy subjects. Understanding these differences is still an ongoing challenge, that can lead to new therapeutic strategies and avoid unfavorable outcomes. In this review, we discuss the different roles of T lymphocyte subsets and interferon-? (IFN-?) in the immune responses of adults and children. Lymphopenia can influence these responses and represent a good predictor for the outcome, as reported by most authors. The increased IFN-? response exhibited by children could be the starting point for the activation of a broad response that leads to MIS-C, with a significantly higher risk than in adults, although a single IFN signature has not been identified. Multicenter studies with large cohorts in both age groups are still needed to study SARS-CoV-2 pathogenesis with new tools and to understand how is possible to better modulate immune responses
Evaluation of a kDNA-Based qPCR Assay for the Detection and Quantification of Old World Leishmania Species
none10noThe parasite protozoan Leishmania, the causative agent of leishmaniasis, includes two subgenera of medical interest: Leishmania (Leishmania) and Leishmania (Viannia). Parasite species detection and characterization is crucial to choose treatment protocols and to monitor the disease evolution. Molecular approaches can speed up and simplify the diagnostic process. In particular, several molecular assays target the mitochondrial DNA minicircle network (kDNA) that characterizes the Leishmania genus. We previously proposed a qPCR assay targeting kDNA, followed by high resolution melt (HRM) analysis (qPCR-ML) to distinguish L. (L.) infantum and L. (L.) amazonensis from L. Viannia species. Successively, this assay has been integrated with other qPCR assays, to differentiate L. (L.) infantum, L. (L.) amazonensis and L. (L.) mexicana. In this work, we tested the applicability of our qPCR-ML assay on L. (L.) donovani, L. (L.) major, L. (L.) tropica and L. (L.) aethiopica, showing that the qPCR-ML assay can also amplify Old World species, different from L. (L.) infantum, with good quantification limits (1 Ă— 10-4-1 Ă— 10-6 ng/pcr tube). Moreover, we evaluated 11 L. (L.) infantum strains/isolates, evidencing the variability of the kDNA minicircle target molecules among the strains/isolates of the same species, and pointing out the possibility of quantification using different strains as reference. Taken together, these data account for the consideration of qPCR-ML as a quantitative pan-Leishmania assay.openCeccarelli, Marcello; Buffi, Gloria; Diotallevi, Aurora; Andreoni, Francesca; Bencardino, Daniela; Vitale, Fabrizio; Castelli, Germano; Bruno, Federica; Magnani, Mauro; Galluzzi, LucaCeccarelli, Marcello; Buffi, Gloria; Diotallevi, Aurora; Andreoni, Francesca; Bencardino, Daniela; Vitale, Fabrizio; Castelli, Germano; Bruno, Federica; Magnani, Mauro; Galluzzi, Luc
Recent transmission clustering of HIV-1 C and CRF17_BF strains characterized by NNRTI-related mutations among newly diagnosed men in central Italy
Increased evidence of relevant HIV-1 epidemic transmission in European countries is being reported, with an increased circulation of non-B-subtypes. Here, we present two recent HIV-1 non-B transmission clusters characterized by NNRTI-related amino-acidic mutations among newly diagnosed HIV-1 infected men, living in Rome (Central-Italy)
Dysregulated Epstein-Barr virus infection in the multiple sclerosis brain
Epstein-Barr virus (EBV), a ubiquitous B-lymphotropic herpesvirus, has been associated with multiple sclerosis (MS), an inflammatory disease of the central nervous system (CNS), but direct proof of its involvement in the disease is still missing. To test the idea that MS might result from perturbed EBV infection in the CNS, we investigated expression of EBV markers in postmortem brain tissue from MS cases with different clinical courses. Contrary to previous studies, we found evidence of EBV infection in a substantial proportion of brain-infiltrating B cells and plasma cells in nearly 100% of the MS cases examined (21 of 22), but not in other inflammatory neurological diseases. Ectopic B cell follicles forming in the cerebral meninges of some cases with secondary progressive MS were identified as major sites of EBV persistence. Expression of viral latent proteins was regularly observed in MS brains, whereas viral reactivation appeared restricted to ectopic B cell follicles and acute lesions. Activation of CD8+ T cells with signs of cytotoxicity toward plasma cells was also noted at sites of major accumulations of EBV-infected cells. Whether homing of EBV-infected B cells to the CNS is a primary event in MS development or the consequence of a still unknown disease-related process, we interpret these findings as evidence that EBV persistence and reactivation in the CNS play an important role in MS immunopathology
Development and Application of a High Resolution Melt (HRM) based test for the Rapid Screening of Leishmania infantum Genotypes
INTRODUCTION
Leishmaniasis includes anthropo zoonotic infectious diseases caused by a protozoan of the Leishmania genus, associated with different clinical manifestations, affecting both humans and other vertebrates, including dogs The Mediterranean basin, including Italy, is considered an endemic area for both visceral and cutaneous leishmaniasis caused by L infantum The multi locus enzyme electrophoresis ( based on the electrophoretic mobility of several enzymes from promastigotes cultures, is considered the reference method for parasite typing Through this method, about 45 L infantum zymodemes (also termed MON) have been identified in humans in the Mediterranean basin 1 Among these, L infantum MON 1 is the most widespread, representing about 70 of all identified strains In Italy, canine infections showed a high prevalence of MON 1 91 with the remaining composed almost exclusively of MON 72 2 Since MLEE technique is cumbersome, time consuming and requires parasites isolation, several biomolecular approaches have been developed In particular, we identified the SNP 390 T>G in malic enzyme ( gene as a potential marker to differentiate the most common L infantum genotype, i e 390 T (corresponding to zymodemes MON 1 72 201 from all others.
AIMS
This study aimed to develop a Rapid Genotype Screening ( assay for L infantum genetic characterization in clinical samples using high resolution melt ( analysis, exploiting the polymorphism 390 T>G in the ME gene
High proliferation of Pseudo-nitzschia cf. arenysensis in the Adriatic Sea: ecological and morphological characterisation
The aim of the present study isto characterise the diatom Pseudo-nitzschia community during a bloom period together with environmental conditions. High proliferation of Pseudo-nitzschia spp. was observed in September 2017 at the shellfish breeding area in the Krka River estuary (Central eastern Adriatic Sea). The peak of abundance (1.8 x 106 cells L-1) was recorded at 7 m depth, and the increased abundance persisted for four weeks.Morphological analyses of field samples based on scanning electron microscopy (SEM) revealed that Pseudo-nitzschia cf. arenysensis was prevailing (94%) in the Pseudo-nitzschia assemblage. Several strains were successfully isolated from net samples in order to better define morphological features and phylogenetic characterisation. The isolated Pseudo-nitzschia strains corresponded morphologically to the P. cf. arenysensis from the field samples, based on our SEM observations. Phylogenetic analysis demonstrated that the Croatian strains grouped with P. arenysensis using the ITS and LSU rDNA sequences. Spearman rank correlation showed that salinity was an important environmental factor affecting the vertical distribution of Pseudo-nitzschia spp. in this highly variable area. Availability of increased concentration of orthophosphates and ammonium and low Si: TIN ratio may have promoted the bloom of P. cf. arenysensis in the estuary
Development and application of a MLST panel for the identification of informative polymorphisms in Leishmania infantum strains in the Mediterranean region
Background. Leishmaniasis is a zoonotic disease endemic in the Mediterranean region, where the causative agent of human and canine infection is Leishmania infantum. The spread of leishmaniasis is associated with population movements, ecology of phlebotomine vectors, and reservoir host. We used multilocus sequence typing (MLST) to explore the genetic variability of L. infantum strains in the Mediterranean region, including the borderline territory of Pantelleria island, and identify informative polymorphisms for rapid identification of genotypes through high-resolution melt (HRM)-based assays.
Material and Methods. A customized sequencing panel targeting 14 housekeeping genes was designed and MLST analysis was performed using the Ion Torrent S5 on 9 L. infantum strains/isolates: 5 canine isolates (3 from Pantelleria Island and 2 from central Italy), and 4 human isolates/strains from Tunisia, France, central and southern Italy. MLST results and in silico analysis of sequences available in Genbank allowed to select two informative polymorphisms on ME and GPI genes (390T/G and 1834A/G, respectively) used to develop two HRM-based assays for fast screening of 28 clinical samples.
Results. The MLST analysis identified a single L. infantum clonal complex regardless of the geographic origin or host (human or canine), except for the human isolate from central Italy that showed polymorphisms in 11 out of 14 housekeeping genes, and clustered independently in a molecular phylogenetic analysis. Successively, the screening through HRM-based assays of 28 clinical samples from central/south Italy and Pantelleria island allowed to identify 6 diploid sequence types (DSTs). Interestingly, the sequence type 390T/1834A was found only in Pantelleria island (prevalence 75%).
Conclusion. This study represents a description of the genetic variability of L. infantum through a first approach based on MLST and then by HRM analysis on selected polymorphisms. The HRM assays could be used as fast and cheap tools for epidemiological surveillance of L. infantum
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