Roberto Brerra

Clinical Isolates of Mycobacterium tuberculosis in Four European Hospitals Are Uniformly Susceptible to Benzothiazinones

ABSTRACT The new antitubercular drug candidate 2-[2-S-methyl-1,4-dioxa-8-azaspiro[4.5]dec-8-yl]-8-nitro-6-(trifluoromethyl)-4H-1,3-benzothiazin-4-one (BTZ043) targets the DprE1 (Rv3790) subunit of the enzyme decaprenylphosphoryl-β-d-ribose 2′-epimerase. To monitor the potential development of benzothiazinone (BTZ) resistance, a total of 240 sensitive and multidrug-resistant Mycobacterium tuberculosis clinical isolates from four European hospitals were surveyed for the presence of mutations in the dprE1 gene and for BTZ susceptibility. All 240 strains were susceptible, thus establishing the baseline prior to the introduction of BTZ043 in clinical trials.

Markers of local immunity in cervico-vaginal secretions of HIV infected women: implications for HIV shedding

Objectives: To link local proinflammatory cytokines with HIV related nucleic acids in cervico-vaginal secretions and the factors associated with them. Methods: An observational study on 60 HIV positive women attending the department of obstetrics and gynaecology, University of Pavia, Italy. HIV-1 RNA in plasma, proviral HIV-1-DNA, cell associated and cell free HIV-1 RNA in cervico-vaginal secretions were evaluated by competitive polymerase chain reaction (c-PCR) and reverse transcriptase PCR (cRT-PCR). IL-1β, IL-6, and TNF-α were measured by ELISA in cervico-vaginal lavages. Multiple regression analysis on ordinal categorical variables was used to test for the simultaneous associations of clinical and microbiological variables on quartiles of cytokine concentrations in lavage samples. Results: Proviral HIV-1 DNA, cell associated and cell free HIV-1 RNA were detected in 76.7% (46/60), 70% (42/60), and 71.7% (43/60) of the patients, respectively. IL-1β concentration was directly correlated with proviral HIV-DNA (Spearman rho = 0.35, p = 0.01) and cell associated HIV-RNA levels (Spearman rho = 0.263, p = 0.05). IL-1β concentration (153.9 pg/ml) was higher (p<0.05) among women with cytological squamous intraepithelial lesion (SIL) than negative controls (73.4 pg/ml). In women with vaginal infection both IL-1β (41.7 pg/ml) and IL-6 (10.2 pg/ml) were lower (p<0.05) in comparison to negative controls (144.9 pg/ml and 23.7 pg/ml, respectively). Women receiving stable antiretroviral therapy had significantly lower TNF-α (34.4 pg/ml versus 44.4 pg/ml, p = 0.04) and higher IL-6 (24.0 pg/ml versus 1.4 pg/ml, p = 0.004) levels in lavage samples compared to untreated women. The associations between the presence of SIL, antiretroviral treatment, vaginal infection and cytokine concentrations in cervico-vaginal secretions were confirmed in multiple regression analysis. Conclusions: Local immune activation may modulate HIV-1 shedding in cervico-vaginal secretion with possible influence on vaginal physiology and host defence. Pharmacological agents lowering HIV-1 replication cause a shift to a pattern of cytokine production which seems less favourable to the transmission of the disease.

Molecular epidemiology of KI and WU polyomaviruses in infants with acute respiratory disease and in adult hematopoietic stem cell transplant recipients

Polyomaviruses KI (KIPyV) and WU (WUPyV) were described recently in children with acute respiratory disease. The pathogenic potential of these human viruses has not been determined completely, but a correlation between immunosuppression and virus reactivation has been suggested. In the present study, the association between KI/WUPyV infection and immunosuppression was investigated using sequential nasopharyngeal aspirates from asymptomatic adult hematopoietic stem cell transplant recipients. In parallel, an investigation on the WU/KIPyV prevalence in children with acute respiratory disease was also carried out. Two of the 126 samples obtained from the 31 hematopoietic transplant recipients were positive for KIPyV (1 sample, 0.79%) and WUPyV (1 sample, 0.79%). Both samples were obtained 15 days after allogeneic transplantation and virus persistence was not observed in subsequent samples. In symptomatic children, 7 of the 486 nasopharyngeal aspirates were positive for WUPyV (1.4%) and 1 for KIPyV (0.2%). Single polyomavirus infection was detected in four patients, whereas the remaining patients were co‐infected with respiratory syncityal virus (three patients) or adenovirus (one patient). The results suggest that WU/KIPyVs have a limited circulation in Italy and a low pathogenic potential in young children. Brief and asymptomatic infection can occur in hematopoietic transplant recipients. J. Med. Virol. 82:153–156, 2010.

Quantitative assessment of cell-associated and cell-free virus in cervicovaginal samples of HIV-1-infected women

OBJECTIVE To examine the amount of cell-free and cell-associated virus in cervicovaginal secretions (CVS) of HIV-infected women. METHODS Paired cervicovaginal and blood samples from 61 seropositive women were quantitatively evaluated by competitive polymerase chain reaction (cPCR) and reverse transcription-PCR (cRT-PCR) for: (1) genomic RNA from plasma and cell-free CVS, and (2) unspliced (u/s) RNA transcripts and proviral DNA in cells from secretions. RESULTS HIV DNA was detected in 42.6%, u/s transcripts in 32.7% and cell-free HIV RNA in 31.1% of 61 cervicovaginal samples. The median copy numbers of HIV DNA, u/s transcripts, and cell-free RNA were 125 copies/10(5) cells, 40 copies/10(5) cells, and 300 copies/mL of secretion, respectively. Nineteen of 26 (73.1%) and 17 of 26 (65.3%) women positive for DNA were also positive for RNA transcripts and cell-free RNA, respectively (P<0.001). A significant correlation between the amounts of cell-free and u/s transcripts was also found (Spearman Rho 0.618, P=0.014). The prevalences of u/s transcripts and cell-free RNA were 42.6% and 53.8% respectively among patients with detectable blood RNA, and 22.9% (P=0.09) and 14.3% (P=0.0017) among patients with undetectable blood RNA. In stepwise logistic regression, cell-free RNA was independently associated with the presence of detectable blood viremia. The amount of HIV DNA was lower among subiects currently under treatment (50 copies/10(5) cells) than in untreated subjects (250 copies/10(5) cells) (P=0.037). CONCLUSIONS Both cell-free and cell-associated HIV could be detected and quantitated in CVS, providing a means to examine the level of viral activity in the female genital tract.

Influence of lingual bracket position on microbial and periodontal parameters in vivo

Objective Lingual orthodontics is becoming more popular in dental practice. The purpose of the present investigation was to compare plaque formation on teeth bonded with the same bracket onto buccal or lingual surface, with non-bonded control teeth, via an in vivo growth experiment over a 30-day period. Material and Methods A randomized controlled trial with split-mouth design was set up enrolling 20 dental students. Within each subject sites with buccal and lingual brackets and control sites were followed. Clinical periodontal parameters (periodontal pocket depth: PPD; bleeding on probing: BOP) were recorded at baseline and on days 1, 7 and 30. Microbiological samples were taken from the brackets and the teeth on days 1, 7 and 30 to detect colony-forming units (CFU). Total CFU, streptococci CFU and anaerobe CFU were measured. Results No significant differences (P>0.05) were found between buccal and lingual brackets in terms of clinical periodontal parameters and microbiological values. Conclusion Bracket position does not have significant impact on bacterial load and on periodontal parameters.

Epidemiological, molecular and clinical features of Enterovirus 109 infection in children and in adult stem cell transplant recipients

BackgroundA novel human enterovirus (HEV) type within the species HEV-C, named EV109, was discovered from cases of respiratory illness in Nicaragua in September 2010. The aim of this study, was to retrospectively examine the presence and the role of EV109 in respiratory samples from two patients populations; infants below the age of 2 years, hospitalized for acute respiratory diseases (ARDs) and adult hematopoietic stem cell transplantation recipients.ResultsA total of 1149 nasopharingeal aspirates were collected and tested for the presence of EV109 by reverse transcription-PCR (RT-PCR). In positive samples, the presence of the most common respiratory viruses was also assayed and clinical symptoms were evaluated. Samples from 2 of the 974 infants tested positive for EV109 RNA (0.2%) and belonged to patients with lower ARDs; co-infection with other viral pathogens under study was observed in both cases. In transplant recipients, one out of the 175 samples analyzed, from a patients with upper respiratory simptoms tested positive for HEV 109 in the absence of co-infecting viruses. Sequence analysis of amplified EV109 genomic regions, showed only a few nucleotide differences when compared with the Nicaraguan strains.ConclusionsOverall these results indicate that HEV109 variants have circulated and differentiated in different lineages worldwide. Although more cases and larger studies are needed, HEV109 infection may be associated to ARDs both in infants and in hematopoietic stem cell transplantation recipients. If these preliminary observations will be confirmed, improved molecular methods with a wider panel of potential pathogens will be useful for monitoring these categories of patients.

Infection and Coinfection of Human Rhinovirus C in Stem Cell Transplant Recipients

In 54 adult stem cell transplant recipients, the presence and persistence of human rhinoviruses (including the novel lineage C) were evaluated by molecular detection and phylogenetic analysis, independently from respiratory symptoms. In the same group of patients, the presence of other coinfecting respiratory pathogens, including the novel enterovirus 109, was also evaluated.

Immunogenicity of hepatitis A-inactivated vaccine administered to seronegative infants, and serological follow-up 12 months after second dose

Aim: To evaluate a) the safety and immunogenicity of anti‐HAV‐inactivated vaccine administered during the first year of life to anti‐HAV seronegative babies, and b) the antibody persistence in a low/intermediate endemic area. Methods: After having obtained informed written consent from mothers, 92 babies were vaccinated at 4 and 10 mo of age. All babies were seronegative at birth and did not present HAV‐RNA shedding in three serial stool samples taken at 1, 2 and 3 mo of age. Results: No general side effects (fever>38°C) were observed. After the first dose of vaccine, 70/82 (85.4%) babies developed anti‐HAV>10 mIU/ml and 36/82 (43.9%)>20 mIU/ml. After the second dose of vaccine, all babies developed a titre>20 mIU/ml, and GMT was 877 mIU/ml. After 1 y of follow‐up, the decreasing rate was similar to that reported for adult populations. Furthermore, three babies doubled the titre observed 1 mo after the second dose, indicating the possible spread of HAV even in a low/intermediate endemic area.