Rosalia Graffeo

Kaposi's Sarcoma Associated with Previous Human Herpesvirus 8 Infection in Kidney Transplant Recipients

ABSTRACT This study investigates the prevalence of human herpesvirus 8 (HHV-8) infection in kidney transplant patients, evaluating the risk of HHV-8 transmission via transplantation and the association between pre- and posttransplantation HHV-8 infection and the subsequent development of Kaposis sarcoma (KS). Immunofluorescence and an enzyme immunoassay were used to determine HHV-8 seroprevalence in 175 patients awaiting kidney transplantation and 215 controls who were attending our clinic for other reasons. All patients in the study came from central or southern Italy. Seroprevalence was similar in both groups (14.8 versus 14.9%), with no significant difference between the rates for male and female patients. Of the 175 patients, 100 were tested for anti-HHV-8 antibodies at various times during follow-up. During follow-up, seroprevalence increased from 12% on the date of transplantation to 26%. This increase was paralleled by an age-related increase in seroprevalence in the control group. During follow-up from 3 months to 10 years after transplantation, KS was diagnosed in seven patients (4.0%). Six of these patients were positive for HHV-8 prior to transplantation. Overall, 23.0% of patients who were HHV-8 positive before transplantation developed KS, whereas only 0.7% of seronegative patients developed the disease (relative risk, 34.4; 95% confidence interval, 4.31 to 274.0). This finding suggests that the key risk factor for KS is infection prior to transplantation and that antibody detection in patients awaiting transplantation could be useful in identifying patients at high risk for KS. In patients from geographic areas with a high prevalence of HHV-8, serological tests on donors may be less important.

Monoclonal antibody fragment from combinatorial phage display library neutralizes alpha-latrotoxin activity and abolishes black widow spider venom lethality, in mice

Alpha-latrotoxin (alpha-ltx), a component of the venom of black widow spiders (BWSV), binds to higher vertebrates presynaptic nerve terminals, stimulating massive neurotransmitter release. This neurotoxic protein is responsible for most of the symptoms elicited in men by the bite of black widow spider (BWS), i.e. a neurological syndrome named latrodectism. By reasoning that targeting this single component would abrogate most of the effect of BWS envenomation, we took advantage of the antibody phage display technology to generate monoclonal Fab fragments able to bind and neutralize the alpha-ltx. To this aim, we immunized Balb/c mice with purified toxin and cloned their antibody repertoire in the pCombIII phage display vector. By combining a high-stringency affinity selection with a sensitive 45Ca(2+) uptake assay, we isolated a Fab fragment (FM1) able to bind the alpha-ltx in the low nM range and neutralize its ionophore activity, in vitro and in vivo. After the onset of overt symptomatology, administration of FM1 to experimentally envenomed mice induced remission of symptoms and prevented lethality. Since alpha-ltx is the only molecule responsible for the great toxicity of BWS bites in mammals, the FM1 Fab, highly effective in neutralizing the toxin in vivo, represents a promising immunotherapy reagent for treating latrodectic patients.

A large spectrum of alpha and beta papillomaviruses are detected in human stool samples.

Human papillomaviruses (HPVs) have been detected in urban wastewaters, demonstrating that epitheliotropic viruses can find their way into sewage through the washing of skin and mucous membranes. Papillomavirus shedding through faeces is still an unexplored issue. The objective of the present study was to investigate the presence of HPVs in stool samples. We analysed 103 faecal specimens collected from hospitalized patients with diarrhoea using validated primers able to detect α, β and γ HPVs. PCR products underwent sequencing analysis and sequences were aligned to reference genomes from the Papillomavirus Episteme database. A total of 15 sequences were characterized from the faecal samples. Thirteen samples (12.6 %) were positive for nine genotypes belonging to the α and β genera: HPV32 (LR, α1), HPV39 (HR, α7), HPV44 (LR, α10), HPV8 (β1), HPV9, HPV23, HPV37, HPV38 and HPV120 (β2). Two putative novel genotypes of the β genus, species 1 and 2, were also detected. The tissue(s) of origin is unknown, since faeces can collect HPVs originating from or passing through the entire digestive system. To our knowledge, this is the first investigation on the occurrence and diversity of HPVs in faecal samples. Results from this study demonstrate that HPVs can find their way into sewage as a consequence of shedding in the faeces. This highlights the need for further studies aimed at understanding the prevalence of HPV in different water environments and the potential for waterborne transmission.

Conjunctival papilloma and human papillomavirus: identification of HPV types by PCR.

Purpose To report the identification of human papillomavirus types in four cases of conjunctival papillomas and to review the literature regarding human conjunctival papillomavirus (HPV). Methods Specimens from conjunctival papillomas of four patients were analyzed for the presence of HPV by polymerase chain reaction and subsequent filter hybridization. HPV types 6, 11, 16, 18, 31, and 33 were investigated. Histologic sections were analyzed for the presence of koilocytosis. Results Histologic examination confirmed HPV infection in all cases. HPV type 11 was detected in all specimens. Conclusions HPV is frequently implicated in the pathogenesis of proliferative squamous lesions. HPV type 11 was the most frequently found in benign conjunctival lesion in this study.

Detection of Rare G3P[19] Group A Rotavirus in Human Patient, Italy

Infection with a rare G3P[19] rotavirus A strain was identified in an immunosuppressed patient in Italy. The strain showed a P[19] viral protein 4 gene and a complete AU-1–like genomic constellation. Phylogenetic analyses showed high nucleotide identity between this strain and G3P[19] rotavirus A strains from Asia, indicating possible reassortment events.

Human Monoclonal Antibody Fragment Specific for Glycoprotein G in Herpes Simplex Virus Type 2 with Applications for Serotype-Specific Diagnosis

ABSTRACT A combinatorial library was used to select a human monoclonal antibody fragment (Fab) with high affinity for G glycoprotein in herpes simplex virus type 2 (HSV-2). Tests with 112 clinical specimens demonstrated successful discrimination between HSV-2 and HSV-1, showing the potential of Fab as a low-cost tool for HSV subtyping in clinical diagnosis.

In vitro effect of clarithromycin and alginate lyase against helicobacter pylori biofilm.

It is now established that the gastric pathogen Helicobacter pylori has the ability to form biofilms in vitro as well as on the human gastric mucosa. The aim of this study is to evaluate the antimicrobial effects of Clarithromycin on H. pylori biofilm and to enhance the effects of this antibiotic by combining it with Alginate Lyase, an enzyme degrading the polysaccharides present in the extracellular polymeric matrix forming the biofilm. We evaluated the Clarithromycin minimum inhibition concentration (MIC) on in vitro preformed biofilm of a H. pylori. Then the synergic effect of Clarithromycin and Alginate Lyase treatment has been quantified by using the Fractional Inhibitory Concentration index, measured by checkerboard microdilution assay. To clarify the mechanisms behind the effectiveness of this antibiofilm therapeutic combination, we used Atomic Force Microscopy to analyze modifications of bacterial morphology, percentage of bacillary or coccoid shaped bacteria cells and to quantify biofilm properties.

Entamoeba dispar: A Rare Case of Enteritis in a Patient Living in a Nonendemic Area

Entamoeba dispar, a common noninvasive parasite, is indistinguishable in its cysts and trophozoite forms from Entamoeba histolytica, the cause of invasive amebiasis, by microscopy. To differentiate the two species seems to be a problem for laboratory diagnosis. Recent experimental studies showed that  E. dispar can be considered pathogenic too. We present a rare case of enteritis due to E. dispar.