Evaluation of a rapid Loop Mediated Isothermal Amplification (LAMP) test for the laboratory diagnosis of sexually transmitted infections

Sexually transmitted infections (STIs) have seen a considerable increase in the last years and given the health burden they may represent from both a personal and community perspective, they require surveillance and prevention programmes based on a timely and decentralized diagnosis. In this context, user-friendly rapid molecular tests may represent a good trade-off between diagnostic accuracy, accessibility and affordability. In this study we evaluated the diagnostic performance of a new real-time LAMP (Loop Mediated Isothermal Amplification) method for the rapid detection and differentiation of 7 major sexually transmissible pathogens by analysing real clinical samples (genital and extra-genital matrices) from individuals with suspected STIs. The assay showed good overall diagnostic performances in terms of sensitivity, specificity and concordance with a gold-standard PCR-based molecular method. This assay, not requiring specialised laboratory technicians or expensive instrumentation, but nonetheless capable of guaranteeing accurate results, is within the reach of outpatient settings, obstetrics, and gynaecology clinic, hence ensuring on-field access to early diagnosis.

The Global Evolutionary History of Orf Virus in Sheep and Goats Revealed by Whole Genomes Data

Orf virus (ORFV) belongs to the genus Parapoxvirus (Poxviridae family). It is the causative agent of contagious ecthyma (CE) that is an economically detrimental disease affecting small ruminants globally. Contagious ecthyma outbreaks are usually reported in intensive breeding of sheep and goats but they have also been reported in wildlife species. Notably, ORFV can infect humans, leading to a zoonotic disease. This study aims to elucidate the global evolutionary history of ORFV genomes in sheep and goats, including the first genomes from Central America in the analyses. In comparison to the last study on ORFV whole genomes, the database now includes 11 more sheep and goat genomes, representing an increase of 42%. The analysis of such a broader database made it possible to obtain a fine molecular dating of the coalescent time for ORFV S and G genomes, further highlighting the genetic structuring between sheep and goat genomes and corroborating their emergence in the latter half of 20th century.

Evaluation of Biofilm Production and Antifungal Susceptibility to Fluconazole in Clinical Isolates of Candida spp. in Both Planktonic and Biofilm Form

Candida spp. are an important opportunistic pathogen that can represent a possible cause of severe infections, especially in immunocompromised individuals. The clinical impact of Candida spp. depends, in part, on the ability to form biofilms, communities of nestled cells into the extracellular matrix. In this study, we compared the biofilm formation ability of 83 strains of Candida spp. isolated from blood cultures and other materials, such as respiratory samples, urine, and exudate, and their sensitivity to fluconazole (FLZ). Strains were divided into tertiles to establish cut-offs to classify isolates as low, moderate, or high biofilm producers (<0.26, 0.266-0.839, >0.839) and biofilms with low, moderate, or high metabolic activity (<0.053, 0.053-0.183, >0.183). A non-linear relationship between biofilm production and metabolic activity was found in C. glabrata and C. tropicalis. In addition, the increase in minimum biofilm eradication concentrations (MBEC50) compared to the Minor Inhibitory Concentration (PMIC) of the planktonic form in Candida spp. confirms the role of biofilm in the induction of resistance to FLZ.

Identification of asymptomatic Leishmania infection in patients undergoing kidney transplant using multiple tests

OBJECTIVES

In immunocompromised patients, asymptomatic Leishmania infection can reactivate, and evolve to severe disease. To date, no test is considered the gold standard for the identification of asymptomatic Leishmania infection. A combination of methods was employed to screen for Leishmania infection in patients undergoing kidney transplant (KT).

METHODS

We employed polymerase chain reaction for the detection of parasitic DNA in peripheral blood, Western blot to identify serum immunoglobulin G and whole blood assay to detect cytokines/chemokines after stimulation of whole blood with parasitic antigen.

RESULTS

One-hundred twenty patients residing in Italy were included in the study at the time of KT. Each patient that tested positive to at least one test was considered as Leishmania positive. Fifty out of 120 patients (42%) tested positive for one or more tests. The detection of specific cell-mediated response (32/111, 29%) was the most common marker of Leishmania infection, followed by a positive serology (24/120, 20%). Four patients (3%) harbored parasitic DNA in the blood.

CONCLUSION

Our findings underline the high prevalence of asymptomatic Leishmania infection in patients undergoing KT in Italy, who are potentially at-risk for parasite reactivation and can benefit from an increased vigilance. Understanding the clinical relevance of these findings deserves further studies.

Circular Health: exploiting the SDG roadmap to fight AMR

Circular Health is a novel approach to address complex health issues that is based on the expansion of the One Health Paradigm. Circular health recognizes the need for a multidisciplinary convergence effort to complement the biomedical dimension of health. Antimicrobial resistance (AMR) is one of the greatest global concerns for public health that is likely on the rise, given the extensive use of antibiotics during the early Covid-19 years. Prior to the Covid-19 pandemic, an expert group chaired by Jim O'Neill published "The Review on Antimicrobial Resistance", which contains a final report and recommendations on how to tackle AMR. The report, for the first time, considers AMR from a multi-perspective viewpoint highlighting how it cannot be successfully addressed unless there is a converging approach encompassing many dimensions of the problem. In this perspective, we propose to include the recommendations from that seminal report and other more recent reviews which include the lessons learnt from the Covid-19 pandemic, into the operational framework of the sustainable development goals (SDGs). AMR represents a perfect case study to explore how the SDG roadmap has the potential of becoming the driving force and implementation tool to address complex health issues by pursuing the optimization of resources and actions via a convergent and multi-stakeholder approach. The implementation of health-related policies through the whole spectrum of the SDGs could be both a novel and a well-established framework to inform multi-dimensional policies for more sustainable health in the future.

Are Parapoxvirus zoonotic diseases doomed to remain neglected?

Parapoxvirus (PPV) infections are considered neglected zoonoses because their incidence is often unknown or greatly underestimated despite being endemic globally. Here, we report the comprehensive diagnostic workflow that led to the identification of two cases of persistent PPV infections. The results obtained underline the importance of adopting a "One Health" approach and cross-sectoral collaboration between human and veterinary medicine for precise aetiological diagnosis and correct management of patients affected by zoonotic diseases.

Updated diagnosis and graft involvement for visceral leishmaniasis in kidney transplant recipients: a case report and literature review

Purpose

Visceral leishmaniasis (VL) has become a rising concern to transplantation teams, being associated with graft dysfunction and reduced survival of renal transplant recipients. Here, we describe a case of VL occurring in a kidney transplant (KT) recipient in Italy, a country in which Leishmania infantum is endemic and we reviewed the literature on the clinical course and diagnosis of VL in KT recipients residing or travelling to southern Europe.

Results

The VL case was diagnosed 18 months after transplant and 28 days after the onset of symptoms by quantitative PCR (qPCR) on peripheral blood. A graft biopsy showed renal involvement, and PCR performed on graft tissue displayed the presence of Leishmania DNA. The retrospective confirmation of Leishmania-positive serology in a serum sample collected before transplantation, as well as the absence of anti-Leishmania IgG in the graft donor strongly suggest that reactivation of a latent parasitic infection caused VL in the current case.

Conclusion

VL is often underdiagnosed in transplant recipients, despite the presence of latent Leishmania infection being reported in endemic countries. This case report, as well as the literature review on leishmaniasis in KT recipients, underline the importance of rapid VL diagnosis to promptly undergo treatment. Serology is scarcely sensitive in immunocompromised patients, thus molecular tests in peripheral blood should be implemented and standardized for both VL identification and follow-up.

Test combination to detect latent Leishmania infection: A prevalence study in a newly endemic area for L. infantum, northeastern Italy

Background

Most people infected with Leishmania remain asymptomatic, which is a common element that may promote the resurgence of clinically evident leishmaniasis in individuals with impaired cell-mediated immune responses. Unfortunately, there is no universally accepted assay to identify asymptomatic infection. This cross-sectional study focuses on the employment of three methods targeting different features of the parasitic infection to be used in combination for the screening of latent leishmaniasis in a newly endemic area of northeastern Italy.

Methodology/principal findings

The selected methods included highly sensitive Real-Time PCR for detection of parasitic kinetoplast (k)DNA in peripheral blood, Western Blot (WB) for detection of specific IgG, and Whole Blood stimulation Assay (WBA) to evaluate the anti-leishmanial T-cell response by quantifying the production of IL-2 after stimulation of patients’ blood with Leishmania specific antigens. Among 145 individuals living in a municipality of the Bologna province, northeastern Italy, recruited and screened for Leishmania infection, 23 subjects tested positive (15.9%) to one or more tests. Positive serology was the most common marker of latent leishmaniasis (15/145, 10%), followed by the detection of specific cell-mediated response (12/145, 8%), while only few individuals (6/145, 4%) harbored parasitic DNA in the blood.

Conclusions/significance

Combining different tests substantially increased the yield of positivity in detecting latent Leishmania infection. The test combination that we employed in this study appears to be effective to accurately identify latent leishmaniasis in an endemic area.

After infection with Leishmania infantum cutaneous or visceral leishmaniasis can develop, but in most cases the host becomes an asymptomatic carrier of the parasite. This key population of individuals with latent leishmaniasis can undergo reactivation of the infection with severe outcome in case of immunosuppression and can contribute to disease transmission.

The public health impact of leishmaniasis is currently underestimated in Europe, despite Leishmania infection is endemic in the Mediterranean countries and outbreaks of human leishmaniasis have been reported in the last decades, including northeastern Italy. One of the causes contributing to this neglect is that the available diagnostic tests exhibit scarce sensitivity in identification of latent leishmaniasis.

In this study, we identified latent Leishmania infection in a newly endemic area of northeastern Italy by using three different diagnostic methods; serological, molecular and immunological tests. Sixteen percent of individuals residing in the selected area were shown to be positive to at least one of the three tests, which indicates a previous contact with the parasite. This study highlights the importance of test combination to enhance the ability to identify latent Leishmania infection.

Organic Electrochemical Transistors as Versatile Tool for Real-Time and Automatized Viral Cytopathic Effect Evaluation

In-vitro viral studies are still fundamental for biomedical research since studying the virus kinetics on cells is crucial for the determination of the biological properties of viruses and for screening the inhibitors of infections. Moreover, testing potential viral contaminants is often mandatory for safety evaluation. Nowadays, viral cytopathic effects are mainly evaluated through end-point assays requiring dye-staining combined with optical evaluation. Recently, optical-based automatized equipment has been marketed, aimed at the real-time screening of cell-layer status and obtaining further insights, which are unavailable with end-point assays. However, these technologies present two huge limitations, namely, high costs and the possibility to study only cytopathic viruses, whose effects lead to plaque formation and layer disruption. Here, we employed poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (Pedot:Pss) organic electrochemical transistors (OECTs) for the real-time, electrical monitoring of the infection of cytolytic viruses, i.e., encephalomyocarditis virus (EMCV), and non-cytolytic viruses, i.e., bovine coronavirus (B-CoV), on cells. OECT data on EMCV were validated using a commercially-available optical-based technology, which, however, failed in the B-CoV titration analysis, as expected. The OECTs proved to be reliable, fast, and versatile devices for viral infection monitoring, which could be scaled up at low cost, reducing the operator workload and speeding up in-vitro assays in the biomedical research field.

Asymptomatic Leishmania infantum infection in blood donors living in an endemic area, northeastern Italy

OBJECTIVES

Human leishmaniasis can be severe and fatal, yet in the Mediterranean region only a small percentage of infections progress to clinical disease. We evaluated the percentage of asymptomatic Leishmania infection in the Bologna province, northeastern Italy.

METHODS

We examined the presence of specific antibodies by Western Blot (WB) and parasitic DNA by real time PCR in peripheral blood of 240 blood donors residing in the Bologna province.

RESULTS

Anti-Leishmania IgG were detected by WB in 27 subjects (11.2%, 95% CI 7%-15%), while Leishmania kinetoplast DNA was detected in peripheral blood specimens of 4 out of 240 donors (1.7%, 95% CI 0.2%-3.2%). Overall, the prevalence of Leishmania infection in the blood donor cohort was 12.5%, thus indicating an elevated cumulative exposure to the Leishmania parasite in the examined municipality.

CONCLUSIONS

Our results suggest that a surveillance system for monitoring Leishmania infection in blood donors and/or strategies of protozoan inactivation in whole blood should be taken into consideration in areas with circulation of the Leishmania parasite.