25 research outputs found
Prevalence and predictors of Lymphogranuloma venereum in a high risk population attending a STD outpatients clinic in Italy
We evaluated LGV prevalence and predictors in a high risk population attending a STI Outpatients Clinic in the North of Italy. METHODS: A total of 108 patients (99 MSM and 9 women), with a history of unsafe anal sexual intercourses, were enrolled. Anorectal swabs and urine samples were tested for Chlamydia trachomatis (CT) DNA detection by Versant CT/GC DNA 1.0 Assay (Siemens Healthcare Diagnostics Terrytown, USA). RFLP analysis was used for CT molecular typing. RESULTS: L2 CT genotype was identified in 13/108 (12%) rectal swabs. All LGV cases were from MSM, declaring high-risk sexual behaviour and complaining anorectal symptoms. Patients first attending the STI Outpatient Clinic received a significant earlier LGV diagnosis than those first seeking care from general practitioners or gastroenterologists (P\u2009=\u20090.0046). LGV prevalence and characteristics found in our population are in agreement with international reports. Statistical analysis showed that LGV positive patients were older (P\u2009=\u20090.0008) and presented more STIs (P\u2009=\u20090.0023) than LGV negative ones, in particular due to syphilis (P\u2009<\u20090.001), HIV (P\u2009<\u20090.001) and HBV (P\u2009=\u20090.001).Multivariate logistic regression analysis revealed that HIV and syphilis infections are strong risk factors for LGV presence (respectively, P\u2009=\u20090.001 and P\u2009=\u20090.010). CONCLUSIONS: Even if our results do not provide sufficient evidence to recommend routine screening of anorectal swabs in high-risk population, they strongly suggest to perform CT NAAT tests and genotyping on rectal specimens in presence of ulcerative proctitis in HIV and/or syphilis-positive MSM. In this context, CT DNA detection by Versant CT/GC DNA 1.0 Assay, followed by RFLP analysis for molecular typing demonstrated to be an excellent diagnostic algorithm for LGV identification
Evaluation of the Versant CT/GC DNA 1.0 assay (kPCR) for the detection of extra-genital Chlamydia trachomatis and Neisseria gonorrhoeae infections.
Screening for extra-genital Chlamydia trachomatis and Neisseria gonorrhoeae infections is a crucial component for sexually transmitted diseases management, even if at present days no commercial methods have been approved for use on pharyngeal and rectal specimens by the US FDA or have received the conformity CE marking. Here we report the analytical sensitivities of the Versant CT/GC 1.0 assay (Siemens Healthcare Diagnostics, Tarrytown, NY, USA) on rectal and pharyngeal swabs, and an evaluation about the suitability for this assay with two widely used swab collection devices (E-Swab and eNAT, Copan, Brescia, Italy). The limits of detection for rectal and pharyngeal specimens with the Versant assay were 10 copies/ml and 1.0 copies/ml, for C. trachomatis and N. gonorrhoeae, respectively. False positive results due to the presence of non-gonococcal Neisseria species were excluded when clinical rectal and pharyngeal samples containing organisms identified as N. meningitidis, N. sicca, N. flavescens and N. subflava were tested. Due to its sensitivity and specificity, the Versant assay represents a good choice for the diagnosis of chlamydial and/or gonococcal infections not only in genito-urinary samples, but also on rectal and pharyngeal swabs
NUOVI APPROCCI PER L\u2019IDENTIFICAZIONE DI SPECIE DI LATTOBACILLI: RUOLO DELLA SPETTROMETRIA DI MASSA MALDI-TOF E DELLA METABOLOMICA
I lattobacilli rappresentano un vasto genere di microrganismi che colonizzano diverse sedi dell\u2019organismo umano, dove svolgono un ruolo chiave nel mantenimento dell\u2019omeostasi microbica. Sebbene il loro ruolo come microrganismi \u2018health-promoting\u2019 sia ben riconosciuto, la loro identificazione a livello di specie pone ancora numerose difficolt\ue0 e si basa sulla combinazione di approcci fenotipici e genotipici.
Scopo del presente studio \ue8 stato quello di comparare diverse metodiche per l\u2019identificazione specie-specifica di 40 ceppi di lattobacilli isolati da campioni clinici (tamponi vaginali/orali, feci) o presenti in formulazioni di probiotici. In particolare, il classico approccio basato sul sequenziamento del gene 16s rRNA \ue8 stato confrontato con un\u2019analisi proteomica ribosomale mediante spettrometria di massa MALDI-TOF e con lo studio dei metaboliti batterici tramite spettroscopia di risonanza magnetica nucleare (1H-RMN).
Il sequenziamento del gene 16s rRNA ha portato alle seguenti identificazioni: 7 L. crispatus, 7 L. gasseri, 5 L. acidophilus, 5 L. delbrueckii, 2 L. vaginalis, 2 L. reuteri, 6 L. plantarum, 1 L. pentosus, 2 L. rhamnosus, 2 L. casei/paracasei e 1 L. brevis. Il relativo albero filogenetico \ue8 stato costruito mediante software MEGA.
L\u2019analisi spettrometrica \ue8 stata condotta dopo estrazione proteica con acido formico/acetonitrile a partire da un pellet batterico di 6x109 cfu. I campioni sono stati analizzati con lo strumento Bruker MicroFlex MALDI-TOF MS e l\u2019identificazione di specie \ue8 stata ottenuta confrontando lo spettro proteico con un database dedicato. Inoltre, a partire dallo spettro medio di ogni ceppo batterico, \ue8 stato costruito un dendrogramma, tramite il software Biotyper 3.1.
L\u2019analisi metabolica in 1H-RMN \ue8 stata eseguita con lo spettrometro AVANCE III (Bruker) sia sull\u2019intero set di metaboliti intracellulari, dopo opportuna lisi batterica, sia sul gruppo di metaboliti extracellulari, a seguito di una crescita batterica di 18-24 ore in brodo MRS.
La spettrometria di massa MALDI-TOF si \ue8 dimostrata altamente affidabile nell\u2019identificazione specie-specifica dei diversi lattobacilli, come dimostrato dall\u2019assoluta sovrapponibilit\ue0 del dendrogramma proteomico con quello genomico basato sul gene 16s rRNA.
L\u2019analisi metabolomica invece non ha consentito un raggruppamento filogenetico delle varie specie, ma ha permesso di identificare metaboliti marker caratteristici, che potrebbero chiarire i meccanismi che stanno alla base dell\u2019effetto protettivo svolto da alcune specie
Novel approaches for the taxonomic and metabolic characterization of lactobacilli: Integration of 16S rRNA gene sequencing with MALDI-TOF MS and 1H-NMR.
Lactobacilli represent a wide range of bacterial species with several implications for the human host. They play a crucial role in maintaining the ecological equilibrium of different biological niches and are essential for fermented food production and probiotic formulation. Despite the consensus about the 'health-promoting' significance of Lactobacillus genus, its genotypic and phenotypic characterization still poses several difficulties. The aim of this study was to assess the integration of different approaches, genotypic (16S rRNA gene sequencing), proteomic (MALDI-TOF MS) and metabolomic (1H-NMR), for the taxonomic and metabolic characterization of Lactobacillus species. For this purpose we analyzed 40 strains of various origin (intestinal, vaginal, food, probiotics), belonging to different species. The high discriminatory power of MALDI-TOF for species identification was underlined by the excellent agreement with the genotypic analysis. Indeed, MALDI-TOF allowed to correctly identify 39 out of 40 Lactobacillus strains at the species level, with an overall concordance of 97.5%. In the perspective to simplify the MALDI TOF sample preparation, especially for routine practice, we demonstrated the perfect agreement of the colony-picking from agar plates with the protein extraction protocol. 1H-NMR analysis, applied to both culture supernatants and bacterial lysates, identified a panel of metabolites whose variations in concentration were associated with the taxonomy, but also revealed a high intra-species variability that did not allow a species-level identification. Therefore, despite not suitable for mere taxonomic purposes, metabolomics can be useful to correlate particular biological activities with taxonomy and to understand the mechanisms related to the antimicrobial effect shown by some Lactobacillus species
Cycle threshold values.
<p>Cycle threshold values of mock and reference specimens obtained by the Versant CT/GC DNA 1.0 Assay, when suspensions containing 10 copies/ml of <i>C</i>. <i>trachomatis</i> (Part A) and 1.0 copies/ml of <i>N</i>. <i>gonorrhoeae</i> (Part B) were tested. Error bars represent standard deviations (SD).</p
Contribution of a comparative western blot method to early postnatal diagnosis of congenital syphilis
Serology has a pivotal role in the diagnosis of congenital syphilis (CS), but problems arise because of the passive transfer of IgG antibodies across the placenta. The aim of this study was to assess the diagnostic value of a comparative Western blot (WB) method finalized to match the IgG immunological profiles of mothers and their own babies at birth in order to differentiate between passively transmitted maternal antibodies and antibodies synthesized by the infants against Treponema pallidum. Thirty infants born to mothers with unknown or inadequate treatment for syphilis were entered in a retrospective study, conducted at St. Orsola-Malpighi Hospital, Bologna, Italy. All of the infants underwent clinical, instrumental, and laboratory examinations, including IgM WB testing. For the retrospective study, an IgG WB assay was performed by blotting T. pallidum antigens onto nitrocellulose sheets and incubating the strips with serum specimens from mother-child pairs. CS was diagnosed in 11 out of the 30 enrolled infants; 9/11 cases received the definitive diagnosis within the first week of life, whereas the remaining two were diagnosed later because of increasing serological test titers. The use of the comparative IgG WB testing performed with serum samples from mother-child pairs allowed a correct CS diagnosis in 10/11 cases. The CS diagnosis was improved by a strategy combining comparative IgG WB results with IgM WB results, leading to a sensitivity of 100%. The comparative IgG WB test is thus a welcome addition to the conventional laboratory methods used for CS diagnosis, allowing identification and adequate treatment of infected infants and avoiding unnecessary therapy of uninfected newborns
Acute Fitz-Hugh-Curtis Syndrome in a Man due to Gonococcal Infection
BACKGROUND:
Fitz-Hugh-Curtis syndrome is a rare extra-pelvic complication of genital infection involving the perihepatic capsule. Most cases have been described in women in association with pelvic inflammatory disease; in rare cases it has been reported in men. Because the main symptom is acute abdominal pain, and laboratory and imaging findings are frequently nonspecific, the differential diagnosis, considering other gastrointestinal or renal diseases, can be difficult in the early stage of the syndrome, leading to frequent misdiagnosis and mismanagement.
CASE REPORT:
We report a case of Fitz-Hugh-Curtis syndrome in a 26-year-old man who first presented to the emergency department with acute abdominal pain, vomiting, and fever. Diagnosis was possible on the basis of clinical signs of orchiepididymitis, abnormal ultrasound findings, and specialist consultation with the Sexually Transmitted Infection Clinic. An acute gonoccocal infection was revealed, which was complicated by a collection of free perihepatic fluid and a subcapsular hypoechoic focal lesion. Prompt antibiotic therapy was established, with complete resolution of the symptoms within a few days. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Awareness of the clinical presentation, imaging, and laboratory findings during the acute phase of Fitz-Hugh-Curtis syndrome could help emergency physicians to make an early diagnosis and to correctly manage such patients. Improved diagnostic skills could prevent chronic complications that are especially a risk in the case of delayed or minor genitourinary symptoms
Surveillance of Antifungal Resistance in Candidemia Fails to Inform Antifungal Stewardship in European Countries
Background: The increasing burden of candidemia and the emergence of resistance, especially among non-Candida albicans strains, represent a new threat for public health. We aimed to assess the status of surveillance and to identify publicly accessible resistance data in Candida spp. blood isolates from surveillance systems and epidemiological studies in 28 European and 4 European Free Trade Association member states. Methods: A systematic review of national and international surveillance networks, from 2015 to 2020, and peer-reviewed epidemiological surveillance studies, from 2005 to 2020, lasting for at least 12 consecutive months and with at least two centers involved, was completed to assess reporting of resistance to amphotericin B, azoles, and echinocandins in C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei, and C. auris. Results: Only 5 (Austria, Italy, Norway, Spain, and United Kingdom) of 32 countries provided resistance data for Candida spp blood isolates. Among 322 surveillance studies identified, 19 were included from Belgium, Denmark, Iceland, Italy, Portugal, Spain, Sweden, Switzerland, and United Kingdom. C. albicans and C. glabrata were the most monitored species, followed by C. parapsilosis and C. tropicalis. C. krusei was not included in any national surveillance system; 13 studies assessed resistance. No surveillance system or study reported resistance for C. auris. Fluconazole, voriconazole, caspofungin, and amphotericin B resistance in C. albicans, C. glabrata, and C. parapsilosis were the most common drug-species combination monitored. Quality of surveillance data was poor, with only two surveillance systems reporting microbiological methods and clinical data. High heterogeneity was observed in modalities of reporting, data collection, and definitions. Conclusion: Surveillance of antifungal resistance in Candida spp blood-isolates is fragmented and heterogeneous, delaying the application of a translational approach to the threat of antifungal resistance and the identification of proper targets for antifungal stewardship activities. International efforts are needed to implement antifungal resistance surveillance programs in order to adequately monitor antifungal resistance
Phylogenetic tree based on lactobacilli 16S rRNA sequences.
<p>The Neighbor-Joining method was used to infer evolutionary history. The evolutionary distances were computed using the Maximum Likelihood method based on Tamura-Nei model [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0172483#pone.0172483.ref032" target="_blank">32</a>]. The tree is drawn to scale, with branch lengths measured in number of substitutions per site. The bootstrap values inferred from 1000 replicates is shown next to the branches. The analysis involved 40 nucleotides sequences. All positions containing gaps and missing data were eliminated. The tree was obtained by using MEGA 6 software.</p
Novel approaches for the taxonomic and metabolic characterization of lactobacilli: Integration of 16S rRNA gene sequencing with MALDI-TOF MS and <sup>1</sup>H-NMR
<div><p>Lactobacilli represent a wide range of bacterial species with several implications for the human host. They play a crucial role in maintaining the ecological equilibrium of different biological niches and are essential for fermented food production and probiotic formulation. Despite the consensus about the ‘health-promoting’ significance of <i>Lactobacillus</i> genus, its genotypic and phenotypic characterization still poses several difficulties. The aim of this study was to assess the integration of different approaches, genotypic (16S rRNA gene sequencing), proteomic (MALDI-TOF MS) and metabolomic (<sup>1</sup>H-NMR), for the taxonomic and metabolic characterization of <i>Lactobacillus</i> species. For this purpose we analyzed 40 strains of various origin (intestinal, vaginal, food, probiotics), belonging to different species. The high discriminatory power of MALDI-TOF for species identification was underlined by the excellent agreement with the genotypic analysis. Indeed, MALDI-TOF allowed to correctly identify 39 out of 40 <i>Lactobacillus</i> strains at the species level, with an overall concordance of 97.5%. In the perspective to simplify the MALDI TOF sample preparation, especially for routine practice, we demonstrated the perfect agreement of the colony-picking from agar plates with the protein extraction protocol. <sup>1</sup>H-NMR analysis, applied to both culture supernatants and bacterial lysates, identified a panel of metabolites whose variations in concentration were associated with the taxonomy, but also revealed a high intra-species variability that did not allow a species-level identification. Therefore, despite not suitable for mere taxonomic purposes, metabolomics can be useful to correlate particular biological activities with taxonomy and to understand the mechanisms related to the antimicrobial effect shown by some <i>Lactobacillus</i> species.</p></div