Group B streptococci (GBS) comprising three different sets of isolates (31 invasive, 36 noninvasive, and 24 colonizing isolates) were collected in Italy during the years 2002 to 2005. Clonal groups were established by pulsed-field gel electrophoresis (PFGE), and selected isolates were studied by multilocus sequence typing (MLST). GBS isolates were also characterized by classical and molecular techniques for serotyping and protein gene and antibiotic resistance profiling. Some serotypes were significantly associated with a particular isolate population: serotype Ia more frequently corresponded to invasive strains than other strains, serotype V was more frequently encountered among noninvasive strains, and nontypeable strains were more common among isolates from carriers. Four major clonal groups accounted for 52.7% of all isolates: PFGE type 1/clonal complex 1 (CC1) comprised mainly serotype V isolates carrying the alp3 gene, PFGE type 2/CC23 encompassed serotype Ia isolates with the alp1 or alpha gene, PFGE type 3/CC17 comprised serotype III isolates carrying the rib gene, and PFGE type 4/CC19 consisted mainly of serotype II isolates possessing the rib gene. The same serotypes were shared by isolates of different clonal groups, and conversely, isolates belonging to the same clonal groups were found to be of different serotypes, presumably due to capsular switching by the horizontal transfer of capsular genes. Erythromycin resistance (prevalence, 16.5%; 15 resistant isolates of 91) was restricted to strains isolated from patients with noninvasive infections and carriers, while tetracycline resistance was evenly distributed (prevalence, 68.1%; 62 resistant isolates of 91). Most erythromycin-resistant GBS strains were of serotype V, were erm(B) positive, and belonged to the PFGE type 1/CC1 group, suggesting that macrolide resistance may have arisen both by clonal dissemination and by the horizontal transfer of resistance genes.Streptococcus agalactiae (group B streptococcus [GBS]) is one of the leading causes of neonatal sepsis and meningitis (2,20,32). The colonization of the female genital tract with GBS is significantly associated with infections in neonates, and it should be carefully monitored. Moreover, GBS has also been recently recognized as an important pathogen in immunocompromised patients (12, 14, 37). The first-line agent against GBS infection is penicillin, and penicillin resistance among GBS strains has not been reported so far (5). However, for patients allergic to penicillin, macrolides (e.g., erythromycin) and lincosamides (e.g., clindamycin) are the alternative choices for the treatment of GBS infections. In the United States, the frequencies of resistance to erythromycin and clindamycin among GBS isolates have been reported to be approximately 37 and 17%, respectively (16).Two main mechanisms of erythromycin resistance in GBS isolates have been described previously (17,25). One mechanism is macrolide-specific efflux encoded by the mef(A)/mef(E) gene ( Capsular serotyping is the classic method fo...

Purpose: On the basis of stimulating data on animals reporting that weekly regimens of zoledronic acid (ZA) were effective in reducing skeletal tumor burden, we designed a study on humans to investigate the potential antiangiogenic role of a weekly low-dose therapy with ZA in patients with malignancies. Experimental Design: Twenty-six consecutive patients with advanced solid cancer and bone metastases received 1mg of ZA every week for four times (days1, 7, 14, and 21) followed by 4 mg of ZA with a standard 28-day schedule repeated thrice (days 28, 56, and 84). Patients were prospectively evaluated for circulating levels of vascular endothelial growth factor (VEGF) just before the beginning of drug infusion (0) and again at 7, 14, 21, 28, 56, and 84 days after the first ZA infusion. Results: The median VEGF basal value showed an early statistically significant (P = 0.038) decrease 7 days after the first 1-mg infusion of ZA.This effect onVEGF-circulating levels persisted also after the following 1-mg infusions at 14 (P = 0.002), 21 (P = 0.001), and 28 days (P = 0.008). Interestingly, the decrease of VEGF-circulating levels persisted also at each programmed time point during the second phase of the study (ZA 4 mg every 4 weeks). No significant differences were recorded in platelet levels,WBC count, or hemoglobin concentration before and after each ZA infusion. Conclusions: In the present study, we report that a repeated low-dose therapy with ZA is able to induce an early significant and long-lasting decrease of VEGF levels in cancer patients.Bisphosphonates are PP i analogues and differ from one another based on their substituted side chains (1). Nitrogencontaining bisphosphonates (N-BP), including pamidronate and zoledronic acid (ZA), inhibit protein prenylation, which in turn interferes with osteoclast function inducing apoptosis of osteoclasts as well as of myeloma and breast cancer cells in vitro (2 -4). Bisphosphonates have a widely recognized role in the treatment of patients with multiple myeloma and bone metastases secondary to breast cancer (5, 6). ZA recently received broad regulatory approval for the treatment of bone metastases secondary to all solid tumor types and bone lesions from multiple myeloma based on the results of three large, randomized, phase III clinical trials enrolling more than 3,000 patients (7,8). Compelling studies suggest that, besides the strong and well-known antiosteoclastic activity, the efficacy of such compounds in oncology could also be due to their antitumor effect, which is exerted at different levels (9). In detail, growing preclinical evidence supports that at least part of the antitumor activity of bisphosphonates may be attributed to an antiangiogenic effect (10). These findings have been confirmed in vivo; systemic administration of 3 Ag/kg ZA to mice resulted in a potent inhibition of angiogenesis induced by s.c. implants impregnated with h-fibroblast growth factor (11). ZA and ibandronate, but not clodronate, decreased revascularization of the ventral prostat...

BackgroundStenotrophomonas maltophilia is emerging as one of the most frequently found bacteria in cystic fibrosis (CF) patients. In the present study, phenotypic and genotypic traits of a set of 98 isolates of S. maltophilia obtained from clinical (CF and non-CF patients) and environmental sources were comparatively evaluated.ResultsS. maltophilia exhibited a high level of genomic diversity in both CF and non-CF group, thus possibly allowing this bacterium to expand its pathogenic potentials. Strains sharing the same pulsotype infected different patients, thus likely indicating the occurrence of clonal spread or acquisition by a common source. CF isolates differed greatly in some phenotypic traits among each other and also when compared with non-CF isolates, demonstrating increased mean generation time and susceptibility to oxidative stress, but reduced ability in forming biofilm. Furthermore, in CF isolates flagella- and type IV pili-based motilities were critical for biofilm development, although not required for its initiation. Sequential isogenic strains isolated from the same CF patient displayed heterogeneity in biofilm and other phenotypic traits during the course of chronic infection. CF and non-CF isolates showed comparable virulence in a mouse model of lung infection.ConclusionsOverall, the phenotypic differences observed between CF and non-CF isolates may imply different selective conditions and persistence (adaptation) mechanisms in a hostile and heterogeneous environment such as CF lung. Molecular elucidation of these mechanisms will be essential to better understand the selective adaptation in CF airways in order to design improved strategies useful to counteract and eradicate S. maltophilia infection.

SummaryIn the present study we investigated the potential role of Toll-like receptor 4 (TLR-4) Asp299Gly and Thr399Ile polymorphisms as risk factors in the development of gastric cancer. TLR-4 Asp299Gly and Thr399Ile polymorphisms were investigated in 171 Italian patients with sporadic gastric cancer and in 151 controls. Unconditional regression (odds ratio and 95% confidence intervals) were used to investigate the association of the studied polymorphisms with gastric cancer. TLR-4 Thr399Ile polymorphism is linked with an increased susceptibility to gastric cancer (P = 0·023 and hazard ratio = 3·62). No significant association for TLR-4 Asp299Gly polymorphism was found. In the subgroup of patients with intestinal-type gastric cancer, a significant risk of gastric cancer was associated with TLR-4 Thr399Ile genotype (P = 0·006). Our results demonstrated that TLR-4 Thr399Ile polymorphism is linked with an increased susceptibility to gastric cancer. An increased risk for intestinal gastric cancer in carriers of the TLR4 Thr399Ile allele was observed. Future epidemiological studies should consider the possible interactions between proinflammatory genotypes (such as TLR and interleukin-1R polymorphisms) and other risk factors for cancer such as dietary habits and/or exposure to environmental carcinogens.

The most common adverse event typically associated with bisphosphonate therapy is transient fever. The aim of this study was to define the role of the main cytokines of the acute-phase reaction interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) involved in the pathogenesis of zoledronic acid-induced fever. Eighteen consecutive cancer patients with bone metastases were treated, for the first time, with a single dose of 4 mg zoledronic acid infusion. They were prospectively evaluated for circulating TNF-alpha, interferon-gamma (IFN-gamma), and IL-6 levels at different times, just before and 1, 2, 7, and 21 days after diphosphonate infusion. Clinical and standard laboratory parameters were recorded at the same time points. TNF-alpha circulating levels increased significantly 1 and 2 days after zoledronic acid infusion (respectively, p = 0.002 and p < 0.001) and then decreased to levels similar to the basal levels. IL-6 levels increased significantly 1 day after the infusion (p = 0.007), returning to values similar to the median basal values 2 days after zoledronic acid administration. Moreover, in patients who experienced fever, the TNF-alpha and IL-6 increases were higher than in patients without fever. No statistically significant differences in IFN-gamma were identified at different time points in patients with and without fever. Our results show that zoledronic acid induces transient TNF-alpha and IL-6 increases and that these increases are higher in patients who have developed fever, suggesting that these cytokines could be responsible for fever pathogenesis. The sharp reduction in serum calcium levels observed in patients with fever may be related to zoledronic acid pharmacokinetic modifications.

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Enterococcal clinical isolates were investigated for the ability to form bio®lm on inert surfaces, as a measure of slime production, in an attempt to ®nd new possible virulence factors for these microorganisms. This property was commonly found among Enterococcus faecalis. Also E. faecium isolates were able to form bio®lm, although to a lesser extent; for this species, however, bio®lm formation seemed more frequently associated with isolates from infection rather than with environmental strains or isolates from healthy individuals. Bio®lm formation was strongly aected by the presence of an additional carbohydrate source in the medium, or by iron deprivation, indicating a role of slime for survival in stressful conditions. Slime-producing E. faecalis were able to survive inside peritoneal macrophages for extended periods compared to slimenegative strains or to slime-positive bacteria grown in conditions depressing slime production. In particular, slime-producing and slime-negative cells showed a decrease of 1 and 2 log units, respectively, at 1 h after infection; slime-negative cells were then rapidly killed, with clearance of bacterial cells at 24 h. Slime-producing bacteria persisted up to 48 h, which was the last time point examined, as after that time viability of both infected and non-infected macrophages started to decline. Scanning electron microscopy observations showed the presence of abundant amorphous extracellular material, of possible polysaccharide nature, embedding bacterial cells to form a multilayered bio®lm. Even in conditions not supporting bio®lm formation, bacterial cells appeared capsulated, suggesting that capsule and slime might represent dierent structures. Genes belonging to the epa locus or to a putative icaA homolog did not seem to be involved in synthesis and export of slime.

The proven antiangiogenic activity of zoledronic acid, a third-generation bisphosphonate widely used in bone metastatic cancer patients, led us to investigate if the vascular endothelial growth factor (VEGF)-related zoledronic acid modifications are correlated with survival advantages in advanced breast cancer patients. Forty-two consecutive breast cancer patients with scintigraphic and radiographic evidence of bone metastases were treated with a single infusion of 4 mg zoledronic acid before anticancer chemotherapy. The patients were prospectively evaluated for circulating levels of VEGF and interferon-gamma (IFN-gamma) just before and at 1, 2, 7, and 21 days after zoledronic acid infusion. Afterward, clinical outcome was prospectively monitored. The basal serum VEGF median levels were significantly decreased at each time point, but the major reduction was recorded 21 days after the infusion. In particular, 25 patients of 42 (59.5%) experienced a reduction of at least 25% in the VEGF circulating levels. In contrast, no statistically significant modifications of the IFN-gamma serum levels were recorded. We stratified patients on the basis of this VEGF reduction 21 days after the infusion. No differences in patient features were recorded between those with or without the VEGF reduction. The analysis of survival showed that patients with a reduction in the VEGF circulating levels had a longer time to first skeletal-related event (p = 0.0002), time to bone progression disease (p = 0.0024), and time to performance status worsening (p = 0.0352) than those without the VEGF reduction. No statistically significant differences were recorded in terms of overall survival and time to visceral progression. This study confirms that zoledronic acid could have an in vivo antiangiogenic property and that the VEGF modifications may represent a surrogate marker able to predict time to first skeletal-related event, time to bone progression disease, and time to worsening of performance status.