Identification and molecular characterization of a S. agalactiae strain lacking the capsular locus.

During a national surveillance program on Group B streptococci (GBS) maternal carriage and neonatal infections, a GBS strain isolated from a pregnant woman's vagino-rectal swab was non typable by either serological or molecular methods. Further molecular characterization demonstrated that the strain lacked the entire capsular locus, possibly by a recombination event that excised a 14,1 Kbase pairs genomic fragment extending from the regulatory protein cpsX gene to the neuA gene. The natural loss of the capsular locus by GBS isolated from a human has never been described so far. Such an event, while possibly a dead-end from the evolutionary point of view, leaves a still able-to-colonize organism unrecognizable by the vaccines currently under development.

Invasive neonatal GBS infections from an area-based surveillance study in Italy.

During an area-based study, 75 group B streptococcus (GBS) strains isolated both from early-onset disease (EOD, 37 strains) and from late-onset disease (LOD, 38 strains) were analysed for serotype, pulsed field gel electrophoresis (PFGE) and multilocus sequence typing profiles, protein markers and antibiotic resistance. Serotype III, possessing the rib gene, was the most frequent (54 strains, 72%) and responsible for 89.5% and 54% of LOD and EOD, respectively. Forty-six serotype III strains belonged to the same PFGE type and clonal complex 17, already described as an over-represented clone in neonatal invasive GBS infections. Other serotypes were Ia (9.3%), II (6.7%), Ib (5.3%), V (5.3%) and IV (1.3%). Seventeen PFGE groups were identified comprising strains with related sequence types; conversely, strains displaying the same sequence type could belong to different PFGE groups. When both neonate and maternal strains from vaginorectal swabs and/or milk were available (eight cases), they were indistinguishable. Resistance to erythromycin (12%) was associated with a constitutive resistance to clindamycin in five cases (four carrying the erm(B) gene and one both the erm(B) and mef(E) genes) and with an inducible clindamycin resistance in two cases (one possessing the erm(A) gene, the other the erm(T) gene). Two isolates displayed the M phenotype (mef(E) gene). All strains but five were resistant to tetracycline, mostly mediated by the tet(M) gene (97.1%). The study underlined the importance of an active surveillance system for the elucidation of a GBS population structure causing neonatal infections and allowed the detection of rare antibiotic resistance determinants [erm(T)].

Hydrogeological studies for radiological monitoring of shallow groundwater in the Eurex plant of Saluggia (Vercelli, Italy).

In 2004, contaminated water was found inside the safety interspace around the spent fuel pool; therefore, an ample monitoring programme of the structure, soils and shallow groundwater was started in order to detect any radioactive leakage into the environment. A first group of piezometers was installed. In the one nearest to the pool, an anomalous activity of (90)Sr ( approximately 10(-2) Bq l(-1)) was found, calling for the following actions: gradual enlarging of the monitoring network, implementation of in situ permeability tests and groundwater tracer test and study of groundwater mobility of the main radionuclides contained in the pool water: (90)Sr, (137)Cs, (241)Am and (239/240)Pu. Because (90)Sr is the only artificial radionuclide detected in groundwater, this study mainly focused on this one. All the investigations demonstrated that (90)Sr coming from the pool is not detectable any longer just some tens of metres from the building and allow the correlation of (90)Sr concentration to flow and water-table fluctuations. Moreover, such a wide mass of hydrogeological and radiological data allows the estimation of an environmental value for environmental radiological significance.

Effect of HSV-2 infection on the expression of HPV 16 genes in CaSki cells.

Human papillomaviruses (HPVs) have been proposed to be the most important etiological factors for cervical cancer although different agents may act in conjunction. Herpes simplex virus type 2 (HSV-2) infection is considered as a possible cofactor to malignant transformation. To examine the influence of HSV-2 infection on the HPV genes expression, CaSki cells bearing 60 to 600 copies of HPV-16 DNA per cell were used as a model system. Twenty hours post HSV-2 infection the mRNA transcripts for HPV-16 early (E1, E2 and E6) and late (L1) genes were analysed by RT-PCR assay. Results indicated that the level of transcription of E1, E2 and E6 genes was up to 3-fold enhanced in HSV-2 infected CaSki cells suggesting that HSV-2 infection could increase the risk of cervical cancer by overexpression of both HPV regulatory and oncogenic genes.

Detection of viral and bacterial infections in women with normal and abnormal colposcopy.

Signs and symptoms of sexually-transmitted diseases (STD) do not allow any etiological diagnosis in women. Colposcopic findings are seldom pathognomic. Consequently, the microbiology laboratory with the recent availability of molecular diagnostic tools is required to detect the infectious bacterial and/or viral agents involved in STD. In cervical samples of women submitted to gynaecological screening for past or present signs and symptoms of inflammation and with different colposcopic findings, we searched by molecular approaches Chlamydia trachomatis, Mycoplasma genitalium, herpes simplex virus type 1 and 2, adenovirus and 45 genotypes of papillomaviruses and, by cultural methods Mycoplasma hominis and Ureaplasma urealyticum. Colposcopy permitted us to divide the studied population into three groups: 48 women had negative colposcopic findings, 50 presented signs of flogosis and 100 resulted positive for an abnormal transformation zone (ANTZ) and/or for HPV colposcopic findings. Results obtained by microbiological assays indicated that the prevalence of infectious agents did not always correlate with colposcopy. Double and triple infections were found in groups 2 and 3, with mycoplasmas being the most common microrganisms present in association and quite almost copresent with papillomaviruses.

The detection of human papillomavirus DNA in skin tags.

Human papillomavirus (HPV) is associated with benign cutaneous or mucosal lesions and with malignant tumours, but none of the HPV types has so far been related to skin tags. Skin biopsy specimens from 49 Caucasian patients suffering from the presence of multiple soft fibromas were analysed by means of dot blot hybridization and by polymerase chain reaction assays aimed at detecting all known HPV types. The results revealed the presence of HPV DNA type 6/11 in 88% of the skin tags examined. This result supports the hypothesis that HPV plays a part in the progression of cutaneous soft fibromas, as previously reported for laryngeal papillomas.