Filippo Canducci

The effect of oral administration of Lactobacillus GG on antibiotic‐associated gastrointestinal side‐effects during Helicobacter pylori eradication therapy

One‐week triple therapy is currently considered the golden standard against Helicobacter pylori. However, gastrointestinal side‐effects are among the major pitfalls in such regimens. Probiotic supplementation might help to prevent or reduce such drug‐related manifestations.

A lyophilized and inactivated culture of Lactobacillus acidophilus increases Helicobacter pylori eradication rates

Acid suppression plus two antibiotics is considered the reference anti‐Helicobacter pylori treatment. Reported eradication rates are around 65–80%. Human Lactobacillus acidophilus shows an in vitro inhibitory effect on the attachment of H. pylori to gastric epithelial cell lines. Culture supernatant of this bacillus seems to decrease the in vitro viability of H. pylori.

Effect of Lactobacillus GG Supplementation on Antibiotic-Associated Gastrointestinal Side Effects during Helicobacter pylori Eradication Therapy: A Pilot Study

Background: One-week triple therapy is currently regarded as the reference of anti-Helicobacter pylori treatment. However, antibiotic-associated gastrointestinal side effects are among the major pitfalls of such regimens. Probiotic supplementation may be regarded as a therapeutic tool to prevent or reduce these troublesome drug-related manifestations. Aim: To determine whether the addition of the probiotic Lactobacillus GG to an anti-H. pylori standard triple therapy could help to prevent or minimize the occurrence of gastrointestinal side effects. Methods: One hundred and twenty healthy asymptomatic subjects screened positive for H. pylori infection and deciding to receive eradication therapy were randomized either to 1-week pantoprazole (40 mg b.i.d.), clarithromycin (500 mg b.i.d.), tinidazole (500 mg b.i.d.) or to the same regimen supplemented with Lactobacillus GG for 14 days. Patients filled in validated questionnaires during follow-up to determine the type and severity of side effects and to judge overall tolerability. Results: Bloating, diarrhea and taste disturbances were the most frequent side effects during the eradication week and were significantly reduced in the Lactobacillus GG-supplemented group (RR = 0.4, CI 0.2–0.8; RR = 0.3, CI 0.1–0.8; RR = 0.3, CI 0.1–0.7, respectively). The same pattern was observed throughout the follow-up period. Overall assessment of treatment tolerability showed a significant trend in favor of the Lactobacillus GG-supplemented group (p = 0.03). Conclusions:Lactobacillus GG supplementation beneficially affects H. pylori therapy-related side effects and overall treatment tolerance.

Two‐year prospective study of single infections and co‐infections by respiratory syncytial virus and viruses identified recently in infants with acute respiratory disease

A prospective 2‐year analysis including 322 infant patients with acute respiratory disease (ARD) hospitalized in a pediatric department in northern Italy was carried out to evaluate the role as respiratory pathogens or co‐pathogens of recently identified viruses. The presence of respiratory syncitial virus (RSV), human Metapneumoviruses (hMPVs), human Bocaviruses (hBoVs), and human Coronaviruses (hCoVs) was assayed by molecular detection and clinical symptoms evaluated. Nasopharyngeal aspirates from 150 of the 322 infants (46.6%) tested positive for at least one pathogen. Ninety samples (28.0%) tested positive for RSV RNA (61.5% genotype A and 38.5% genotype B), 46 (14.3%) for hMPV RNA (71.7% subtype A and 28.3% subtype B), 28 (8.7%) for hCoV RNA (39.3% hCoV‐OC43, 35.7% hCoV‐NL63, 21.4% hCoV‐HKU1, and 3.6% hCoV‐229E), and 7 (2.2%) for hBoV DNA (of the 6 typed, 50% subtype 1 and 50% subtype 2); 21/150 samples revealed the presence of 2 or more viruses. Co‐infection rates were higher for hMPVs, hCoVs, and hBoV (38.3%, 46.4%, and 57.1%,) and lower for RSV (23.3%). RSV was associated with the presence of complications (P < 0.001) and hypoxia (P < 0.015). When the presence of RSV alone and the RSV‐hMPV co‐infections were considered, RSV mono‐infected patients resulted to have longer hospitalization and higher hypoxia (P < 0.001). The data highlight that (i) RSV has a central role as a respiratory pathogen of infants, (ii) the wide circulation of recently identified viruses does not reduce the clinical and epidemiological importance of RSV, and that (iii) recently identified agents (hMPVs, hBoVs, and hCoVs) act as primary pathogens or co‐pathogens. J. Med. Virol. 80:716–723, 2008.

Use of Genotype MTBDR Assay for Molecular Detection of Rifampin and Isoniazid Resistance in Mycobacterium tuberculosis Clinical Strains Isolated in Italy

ABSTRACT Mycobacterium tuberculosis is one of the leading causes of death worldwide, and multidrug-resistant tuberculosis (MDR-TB) is associated with a high case fatality rate. Rapid identification of resistant strains is crucial for the early administration of appropriate therapy, for prevention of development of further resistance, and to curtail the spread of MDR strains. The Genotype MTBDR (Hain Lifescience, Nehren, Germany) is a reverse hybridization line probe assay designed for the rapid detection of rpoB and katG gene mutations in clinical isolates. The ability of this technique to correctly identify resistant and MDR-TB strains was tested on 206 isolates from the Italian drug resistance surveillance system. This panel included the majority of MDR strains isolated in Italy in the past 3 years. The results of the test were compared to conventional drug susceptibility test performed on isolated strains and verified by sequencing the regions of interest of the bacterial genome. The rate of concordance between the results of the MTBDR and those obtained with “in vitro” sensitivity was 91.5% (130 of 142) for rifampin and 67.1% (116 of 173) for isoniazid. We also applied this test directly to a panel of 36 clinical specimens collected from patients with active TB. The MTBDR correctly identified the two cases of MDR-TB included in the panel. These results show that the MTBDR test is useful in the detection and management of tuberculosis when MDR disease is suspected.

Cross-resistance Profile of the Novel Integrase Inhibitor Dolutegravir (S/GSK1349572) Using Clonal Viral Variants Selected in Patients Failing Raltegravir

Novel integrase inhibitors are in advanced clinical development, and cross-resistance data are needed to consider the possibility to plan a sequential usage within this class of antiretroviral drugs. Ex vivo phenotypic assays were conducted on 11 wild-type and 27 fully replicating recombinant viruses obtained from 11 patients failing previous raltegravir-containing regimens. Dolutegravir maintained its activity in vitro on viruses with mutations in position 143 and 155. However, viruses with mutation Q148R associated with secondary mutations and the combination Q148H+G140S were instead associated with a reduced level of susceptibility to dolutegravir in vitro.

Persistent Symptomless Human Metapneumovirus Infection in Hematopoietic Stem Cell Transplant Recipients

Sequential nasopharyngeal aspirates from patients without respiratory symptoms undergoing hematopoietic stem cell transplantation (HSCT) were tested for genomic RNA of human metapneumovirus (hMPV). Persistent hMPV infection was documented in most of them and confirmed by virus isolation. hMPV infection etiology was also evaluated during the same period in samples from pediatric patients with acute respiratory diseases (ARDs). Sequence analysis of hMPV in HSCT recipients documented infection by hMPV genotype A and strong interhost similarity; this pattern differs from that observed in pediatric patients with ARDs. The data indicate that HSCT recipients may frequently develop symptomless hMPV infection.

Dynamic patterns of human immunodeficiency virus type 1 integrase gene evolution in patients failing raltegravir-based salvage therapies.

Objective:Evaluate HIV-1 subtype B integrase gene evolution in patients failing raltegravir (RAL)-based savage regimens by clonal analysis of the replicating viral quasispecies. Design:Seven triple class failure HIV-1 (subtype B)-infected patients, followed at San Raffaele Hospital and enrolled in the RAL Expanded Access Program (MK0518-023), were evaluated. Patients were followed up for 24–48 weeks and due to the absence of other active drugs, RAL was maintained in their regimens even if resistance mutations were detected. Methods:Immunologic and virologic parameters were recorded every 4 weeks, and amplification and clonal analysis of viral populations were performed at baseline and every 4–12 weeks in all patients. Results:Resistance to RAL appeared initially associated with selection of single variants (Y143R, Q148R N155H) in the majority of patients; however, in three patients, complex patterns of viral mutations were observed. The clonal analysis of viral quasispecies allowed to describe the evolution of each viral population and the progressive accumulation of RAL resistance-associated mutations and polymorphisms associated with therapy failure. Conclusion:The complex patterns of resistance mutations observed, including novel variants evolved under continuous RAL pressure, suggesting that they are the result of the equilibrium between drug resistance and enzyme function. Despite the efficacy of this compound, our data discourage its use in a functional monotherapy and maintaining RAL even in presence of RAL resistance-associated mutations may lead to the progressive formation of viral reservoirs with multiple integrase inhibitor-resistant variants that may limit the future efficacy of other integrase inhibitors due to cross-resistance.

The role of infections and coinfections with newly identified and emerging respiratory viruses in children

Acute respiratory infections are a major cause of morbidity in children both in developed and developing countries. A wide range of respiratory viruses, including respiratory syncytial virus (RSV), influenza A and B viruses, parainfluenza viruses (PIVs), adenovirus, rhinovirus (HRV), have repeatedly been detected in acute lower respiratory tract infections (LRTI) in children in the past decades. However, in the last ten years thanks to progress in molecular technologies, newly discovered viruses have been identified including human Metapneumovirus (hMPV), coronaviruses NL63 (HcoV-NL63) and HKU1 (HcoV-HKU1), human Bocavirus (HBoV), new enterovirus (HEV), parechovirus (HpeV) and rhinovirus (HRV) strains, polyomaviruses WU (WUPyV) and KI (KIPyV) and the pandemic H1N1v influenza A virus. These discoveries have heavily modified previous knowledge on respiratory infections mainly highlighting that pediatric population is exposed to a variety of viruses with similar seasonal patterns. In this context establishing a causal link between a newly identified virus and the disease as well as an association between mixed infections and an increase in disease severity can be challenging. This review will present an overview of newly recognized as well as the main emerging respiratory viruses and seek to focus on the their contribution to infection and co-infection in LRTIs in childhood.

Monoclonal antibodies isolated from human B cells neutralize a broad range of H1 subtype influenza A viruses including swine-origin Influenza virus (S-OIV)

The new H1N1 swine-origin influenza virus (S-OIV) strain is a global health problem. The elucidation of the virus-host relationship is crucial for the control of the new infection. Two human monoclonal antibody Fab fragments (HMab) neutralizing the novel H1N1 influenza strain at very low concentrations were cloned before the emergence of S-OIV from a patient who had a broad-range H1N1 serum neutralizing activity. The two HMabs neutralized all tested H1N1 strains, including S-OIV and a swine strain with IC(50) ranging from 2 to 7 microg/ml. Data demonstrate that infection with previously circulating H1N1 strains can elicit antibodies neutralizing S-OIV. Finally, the human genes coding for the neutralizing HMabs could be used for generating full human monoclonal IgGs that can be safely administered being potentially useful in the prophylaxis and the treatment of this human infection.