Genetic diversity of Streptococcus suis clinical isolates from pigs and humans in Italy (2003-2007).

Streptococcus suis, a major porcine pathogen, is emerging as a zoonotic agent capable of causing severe invasive disease in humans exposed to pigs or pork products. S. suis infection is rare in industrialised countries and usually arises as sporadic cases, with meningitis the most common clinical presentation in humans. Recent reports of two cases of meningitis in Sardinia and northeastern Italy prompted this first characterisation of Italian S. suis isolates. Fifty-nine S. suis strains, the two recent human strains and 57 swine clinical isolates collected between 2003 and 2007 from different Italian herds and regions, were tested for antimicrobial susceptibility, PCR-screened for virulence and antibiotic resistance genes, and subjected to molecular typing. Phenotypic and genotypic analysis demonstrated an overall high genetic diversity among isolates, the majority of which were resistant to macrolides (78%) and tetracyclines (90%). The erm(B), tet(O), mosaic tet(O/W/32/O), tet(W), and tet(M) genes were detected. The tet(O/W/32/O) gene, the most frequent tet gene after tet(O), had never been described in the genus Streptococcus before. In addition, a virulent cps2, erm(B) tet(O) clone, belonging to sequence type 1 (ST1) of the ST1 complex, was found to be prevalent and persistent in Italian swine herds. Finally, the two human isolates (both ST1) carrying cps2, erm(B) and tet(W) were seen to be closely related to each other.

Lactobacillus rhamnosus GG inhibits invasion of cultured human respiratory cells by prtF1-positive macrolide-resistant group A streptococci.

AIMS: This study was designed to determine whether the probiotic strain Lactobacillus GG, which is extensively used in the treatment and prevention of intestinal disorders, is able to inhibit invasion of cultured human respiratory cells by macrolide-resistant group A streptococci (GAS) carrying the prtF1 gene, which encodes the fibronectin (Fn)-binding invasin F1. METHODS AND RESULTS: Eight prtF1-positive erythromycin-resistant GAS strains were used to infect A549 monolayers in competition and displacement assays with Lactobacillus GG. Live (L-LGG) and heat-killed (HK-LGG) lactobacilli and their spent culture supernatant (SCS) significantly reduced (P < 0.001) GAS invasion efficiency in both assays. No antibacterial activity of Lactobacillus GG against GAS was detected. Both L-LGG and HK-LGG and all prtF1-positive GAS induced a strong agglutination reaction using Fn-coated particles. CONCLUSIONS: Lactobacillus GG exerts an antagonistic action against GAS by inhibiting cell invasion. Competitive binding of Lactobacillus GG and GAS to Fn might be involved in the inhibition process. SIGNIFICANCE AND IMPACT OF THE STUDY: The finding that Lactobacillus GG can prevent in vitro invasion of respiratory cells by GAS suggests new applications for this probiotic strain and warrants further studies of its capacity to prevent GAS throat infections.

[The polycentric multiple arc complanar technic, or telebrachytherapy. A 4-year experience (an innovative way for the local control of solid neoplasms)]. / La tecnica complanare "policentrica ad archi multipli", ovvero la telebrachiterapia. Quattro anni di esperienza (una via innovativa per il controllo locale delle neoplasie solide).

The coplanar polycentric multiple 180 degrees single arc and narrow beams technique (PMA) allows high radiation doses to be delivered to the target, with similar dose distribution to that of brachytherapy. Since 1990, more than 100 patients have been treated: 80 had NSCLC, 12 had epidermoid head and neck (oral cavity and oropharynx) cancers, 8 brain tumors, 4 esophageal cancers and, sporadically, other patients had many other kinds of tumors, e.g., Hodgkin's and non-Hodgkin's lymphomas and sarcomas. X photons of a 12-MV Linac have always been used. NSCLC patients are assessable for local control, toxicity and survival, while the other patients only for local control and/or toxicity. As for 31 stage I-II lung cancer patients, CR has been observed in 82.8% of them and PR in 13.8%; the response was always assessed with chest radiography, CT, FBS, cytology and/or histology. The overall actuarial survival rate is 71% at 40 months, the disease-free survival rate is 75% and the local progression-free survival rate is 94%. As for 49 stage-III patients, CR has been observed in 40% of them and PR in 56%. The overall disease-free survival is 10% at 28 months (median survival: 14.37 +/- 0.6 months). The disease-free survival rate is 23%. The local progression-free survival rate is similar to the overall survival rate, which seems to prove the very high metastatic spread of this disease in advanced stages. Twelve head and neck cancer patients have been treated, 5 of them in stage II and 7 in stage IV. CR has been observed in all the patients in lower stages (100%), in 4/7 patients in stage IV (57%) and in 4/5 patients (80%) in the T4N0 subgroup. The response of brain tumors treated with the PMA technique is difficult to assess because radiographic, CT and MR images are difficult to correlate with patients clinical status. The patients in our series are still alive, with a medium follow-up of 7 months (range: 2-16 months). A longer follow-up is necessary before any other considerations on the effectiveness of this method can be made. This technique was used on the patients who were not eligible for the other techniques with high doses delivered to the tumor, because of its volume and/or shape. Four esophageal cancers were treated with palliative intent, because of absolute dysphagia, in alternative to HDR brachytherapy. All these patients have obtained symptom remission.(ABSTRACT TRUNCATED AT 400 WORDS)

[Brachytherapy of epistaxis in Rendu-Osler disease. Indications, technic, results]. / La brachiterapia dell'epistassi nel morbo di Rendu-Osler. Indicazioni, tecnica, risultati.

Rendu-Osler disease is a clinical form characterized by skin, mucous and bowel teleangiectasias causing repeated bleeding, especially in the nasal region. Repeated epistaxis is controlled, however transiently, with electrocoagulation, laser therapy, embolization, mucous transplants and external radiotherapy or, more frequently, brachytherapy. The authors report on a Curietherapy technique based on the use of 192Iridium wires. The wires, which cannot be placed in parallel lines, must be positioned in three places after a fan-wise pattern: the first one on the floor, the second one along the anterior wall and the third one in between. The three wires are inserted into plastic tubes during fluoroscopy. The length of the wires is differentiated for greater dose distribution homogeneity. The dose given to the reference isodose--which is probably in contact with the mucosa--is 30 Gy. We performed 9 maneuvers in 6 patients and three of them were also treated in the contralateral nostril. Complete remission was seen in 4 patients. In 2 patients the response has lasted 18 and 32 months and 2 others have a shorter follow-up. In 5 patients we obtained a good response (mean: 58 months). Our results are in agreement with those in brachytherapy literature. Few trials are reported of external irradiation but in our personal experience, its results are poor. Brachytherapy effect is limited in time but yields major clinical benefits to the patient. Brachytherapy cannot replace other treatment methods and must therefore be considered as a palliative treatment which can improve patient's quality of life in time.

[Quality assurance in diagnostic radiology using an automated system. Experience and results]. / Garanzia di qualità in radiodiagnostica con l'impiego di un sistema automatico. Esperienza e risultati.

The authors report their personal experience with the use of an integrated quality control system in the radiology department. The system we used was the RTI DIGI-X Plus, a Swedish-made product, allowing a wide range of parameters to be measured on diagnostic X-ray units for general radiography, mammography and fluoroscopy. Data can be retrieved with a minimum number of measurements. The "oRTIgo" software improves the quality assurance system and ensures document compliance with international recommendations. The equipment consists of a detector unit, a processor and a display unit. The detector consists of a rotating holder with 12 combinations of metal filters of various thickness mounted in front of two photo-diodes covered with identical X-ray intensifying gadoliniumoxysulfide screens. This unit is connected to a data acquisition system controlled by a microcomputer. Peak tube voltage and total tube filtration are derived from the ratio of detector signals. The relationship between this ratio and the measured quantity is determined by a calibration procedure. Furthermore, exposure time "mAs" value, "mAs" linearity and exposure (or kerma in air) can be measured. Digital storage can be performed and input signals displayed. A serial interface is used to communicate with a PC for QC management purposes. An error propagation model is used to determine the inaccuracy of peak tube voltage measurements. With the DIGI-X Plus system, measurements can be carried out in a shorter time and the stored data reprocessed later on. After QA testing on 20 X-ray units in the radiology department, in vivo doses were measured using a TLD Harshaw 100 on 46 randomly selected patients undergoing chest examinations. The results are reported and analyzed following the NRPB protocol and show high agreement with the recommended values.

[Brachytherapy in choroid tumors]. / Brachiterapia dei tumori coroidei.

Even though brachytherapy has been used for many years to treat choroidal tumors, it is not a widespread technique because it requires much organization and operators skills. The most common methods use 60Cobalt and 106Rutenium plaques, or custom-made plaques with 125Iodine loaded seeds. Another, less common, technique uses 192Iridium wires loaded on custom-made plaques. The technique we used to treat 4 retinoblastomas and 2 choroidal melanomas uses 192Iridium wires loaded on custom-made plaques. The applicator is made of a quick drying paste poured over a sphere the same size as the eye-ball: plastic tubes are inserted, according to preliminary dosimetric measurements, to house the Iridium wires. The applicator is positioned on the eye-ball corresponding to tumor site by surgery. The Iridium sources are inserted into the plastic tubes at the end of surgical placement: this afterloading technique guarantees maximal staff protection. 192Iridium (320 keV gamma emitter) allows the dose to be transmitted deeper than with 125Iodine (30 keV gamma-emitter) and 106Rutenium (3540 keV beta-emitter). Therefore, with Iridium, the dose delivered is lower on the eye-ball surface for the same tumor dose. On the other hand, the use of 60Cobalt (1250 keV gamma-emitter) gives the healthy surrounding tissues higher doses. To conclude, this method allows us to customize the application to every single case, to reach posterior sites, to ensure radioactive protection to staff thanks to afterloading and to obtain a good depth to surface dose ratio.