Non-B HIV type 1 subtypes among men who have sex with men in Rome, Italy.

An increase in the circulation of HIV-1 non-B subtypes has been observed in recent years in Western European countries. Due to the lack of data on the circulation of HIV-1 non-B subtypes among European HIV-1-infected men who have sex with men (MSM), a biomolecular study was conducted in Rome, Italy. HIV-1 partial pol gene sequences from 111 MSM individuals (76 drug naive and 35 drug experienced) were collected during the years 2004-2006. All these sequences were analyzed using the REGA HIV-1 Subtyping Tool, and aligned using CLUSTAL X followed by manual editing using the Bioedit software. A BLAST search for non-B subtype sequences was also performed. Twenty-six (23.4%) MSM were not Italians. Eight individuals (7.2%) were diagnosed as HIV infected before 1991, 20 (18.0%) between 1991 and 1999, and 83 (74.8%) from 2000 to 2006. Fifteen (15/111, 13.5%) individuals were infected with the non-B subtype. The percentage of infection with HIV-1 non-B subtypes was 8.2% (7/85) among Italian MSM and 30.8% (8/26) among the non-Italians (OR = 4.95 95% IC: 1.40-17.87). Individuals infected with the non-B subtype were significantly younger than those infected with the HIV-1 B subtype (28 years vs. 34 years, p = 0.003). The CRFs were more prevalent (8.1%) than pure subtypes (5.4%), which were distributed as follows: subtype C (2.6%), subtype A1 (1.7%), and subtype F1 (0.9%). Major mutations conferring resistance to antiretroviral drugs (ARV) were not found among HIV-1 non-B subtype drug-naive patients but were found in two ARV-experienced individuals. The data show that viral diversity is likely increasing in a population group that had been previously characterized by the circulation of HIV-1 subtype B.

Amino acid changes in the attachment G glycoprotein of human respiratory syncytial viruses (subgroup A) isolated in Italy over several epidemics (1997-2006).

The human respiratory syncytial virus (HRSV) is the most important cause of admission to hospital for acute lower respiratory tract infections in infants and young children worldwide. Only few studies have investigated the molecular evolution of HRSV, and none has been conduct ed in Italy. The genetic diversity of the G glycoprotein of 59 subgroup A strains obtained from two clinical centers located in Northern and Central Italy was studied, during seven nonconsecutive epidemic seasons (1997-2006). The nucleotide sequences encompassing 624 bp, at the carboxy terminus of the G glycoprotein gene, were compared to sequences representative of previously defined HRSV genotypes. Phylogenetic analysis indicated that most Italian group A isolates clustered into two different lineages (GA2 and GA5), whereas only few isolates grouped into the other known lineages. Eight positively selected sites were found and it was predicted that serine and threonine of positively selected sites 117 and 262 (respectively) are O-glycosilated. The presence of multiple identical sequences in three lineages (GA1, GA5, and BE/A1) suggests that certain strains are predominant in a given epidemic season. Although most of the sites of the G glycoprotein gene of HRSV-A strains seem invariable because of strong purifying selection, some evolutionary "hot spots" may be present. Since the G glycoprotein is a major target (together with the F glycoprotein) of the HRSV humoral immune response, it is important to provide information about its genetic heterogeneity in order to address better both therapeutic and vaccine strategy.