Giulia Lorino

Toll-like receptor 4 Asp299Gly and Thr399Ile polymorphisms in gastric cancer of intestinal and diffuse histotypes.

In 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.

Routine molecular identification of enterococci by gene-specific PCR and 16S ribosomal DNA sequencing.

ABSTRACT For 279 clinically isolated specimens identified by commercial kits as enterococci, genotypic identification was performed by two multiplex PCRs, one with ddlE. faecalis andddlE. faecium primers and another withvanC-1 and vanC-2/3 primers, and by 16S ribosomal DNA (rDNA) sequencing. For 253 strains, phenotypic and genotypic results were the same. Multiplex PCR allowed for the identification of 13 discordant results. Six strains were not enterococci and were identified by 16S rDNA sequencing. For 5 discordant and 10 concordant enterococcal strains, 16S rDNA sequencing was needed. Because many supplementary tests are frequently necessary for phenotypic identification, the molecular approach is a good alternative.

Group A Streptococcal Genotypes from Pediatric Throat Isolates in Rome, Italy

ABSTRACT In a study assessing genetic diversity, 114 group A streptococcus (GAS) isolates were recovered from pediatric pharyngitis patients in Rome, Italy. These isolates comprised 22 different M protein gene (emm) sequence types, 14 of which were associated with a distinct serum opacity factor/fibronectin binding protein gene (sof) sequence type. Isolates with the same emmgene sequence type generally shared a highly conserved chromosomal macrorestriction profile. In three instances, isolates with dissimilar macrorestriction profiles had identical emm types; in each of these cases multilocus sequence typing revealed that isolates with the same emm type were clones having the same allelic profiles. Ninety-eight percent of the pharyngeal isolates hademm types previously found to be highly associated withmga locus gene patterns commonly found in pharyngeal GAS isolates.

Erythromycin-Resistant Pharyngeal Isolates of Streptococcus pyogenes Recovered in Italy

ABSTRACT Three classes of macrolide resistance phenotypes and three different erythromycin resistance determinants were found among 127 erythromycin-resistant group A streptococcal (GAS) isolates recovered from 355 (35.8%) pediatric pharyngitis patients in Rome, Italy. According to emm and sof sequence typing results, erythromycin-resistant isolates comprised 11 different clonal types. Remarkably, 126 of the 127 macrolide-resistant isolates were serum opacity factor (sof) gene positive. These data suggest a strong association between macrolide resistance and the presence of sof among GAS isolates recovered from Italian pediatric pharyngitis patients.

Macrolide resistance genotypes and phenotypes among erythromycin-resistant clinical isolates of Staphylococcus aureus and coagulase-negative staphylococci, Italy.

One hundred macrolide-resistant staphylococcal isolates from clinically relevant infections in Italy during a 19-month period were studied. Four distinct resistance phenotypes were observed using the triple-disk induction test (erythromycin, clindamycin, telithromycin): the cMLS(B) phenotype (24 isolates); the iMLS(B) phenotype (41 isolates); the MS phenotype (three isolates); and the iMTS phenotype (erythromycin-induced telithromycin resistance) (32 isolates). ermC and ermA genes predominated within erythromycin-resistant Staphylococcus aureus isolates with iMLS(B) phenotype and cMLS(B) phenotype, respectively. Among erythromycin-resistant CoNS isolates, half of the strains showed the iMTS or MS/msrA association, and ermC gene predominated among isolates with MLS(B) phenotype. By pulsed-field gel electrophoresis, high genetic heterogeneity was observed among the isolates studied. Both independent acquisition of macrolide resistance genes and spread of specific resistant clones were observed. Association between certain clonal types and specific types of infection could be detected. To our knowledge, this is the first report on characterization of erythromycin-resistant staphylococci in Italy.

NOD2/CARD15 polymorphisms impair innate immunity and increase susceptibility to gastric cancer in an Italian population.

In the present case-control study we investigated the potential role of CARD15 R702W, G908R, and 1007fs polymorphisms in Italian gastric cancer patients. The study population consisted of 170 gastric cancer patients and 156 controls. Unconditional regression (odds ratios and 95% confidence interval) was used to investigate the association of the studied polymorphisms with gastric cancer. Higher allele frequencies of R702W and 1007fs polymorphisms were observed in patients with gastric cancer compared with controls (8.53 vs 2.3 and 9.4 vs 0.7, respectively). CARD15 R702W and 1007fs polymorphisms were significantly correlated with gastric cancer incidence (p < 0.0001, p < 0.0001, respectively). No correlation was found upon analyzing the G908R single nucleotide polymorphism (SNP). Our study reports an increased susceptibility to gastric cancer in Italian populations when R702W and 1007fs polymorphisms in the coding region of CARD15 are present. The interaction between NOD-induced proinflammatory cytokines on gastric mucosa and environmental carcinogens could represent one of the mechanisms by which CARD15 polymorphisms increase the susceptibility to gastric cancer. Meta-analyses of these SNPs and further analyses of additional polymorphisms/haplotypes in NOD genes will help determine their role in carcinogenesis.

Genotypes of invasive pneumococcal isolates recently recovered from Italian patients.

ABSTRACT We examined 73 recent invasive pneumococcal isolates within selected areas of Italy for genotypic variability. Thirty-three genomic macrorestriction types were found, three of which represented multiple serotypes. Restriction fragment patterns of pbp2b, pbp2x, and pspA were conserved within the majority of isolates that shared macrorestriction types. Of the nine macrorestriction types found among the 22 penicillin-nonsusceptible Streptococus pneumoniae (PNSP) isolates, seven comprised isolates with allelic profiles showing five to seven allelic matches to profiles in the multilocus sequence typing database (www.mlst.net ); however, three of the seven profiles represented serotypes not previously associated with these clonal clusters. Two PNSP macrorestriction types represented new clones with unique allelic profiles. Allelic profiles obtained from isolates of 3 of the 25 macrorestriction types found among the 51 penicillin-susceptible S. pneumoniae (PSSP) isolates were closely related to previously described profiles. One PSSP isolate was a novel type 24F isolate related to the multiresistant clone France9V-3. This work reports new PNSP strains and new serotype-clone associations.

Detection of antibodies to hepatitis C virus in dialysis patients.

Dialysis patients are at risk for infection by a variety of blood-borne agents trasmitted within dialysis units.The development of the hepatitis C virus (HCV) screening test prompted many studies on the prevalence of anti-HCV among dialysis patients.The authors have evaluated the prevalence of anti-HCV in 405 hemodialysis patients both by Elisa screening and 4-RIBA test system with a follow-up of two years.The study showed a difference in the incidence of antibodies to HCV by year. In 1990, 15.2% were positive with an increase to 20.8% in 1991. There was an increase of 5% in dialysis patients and only 1.9% in the personnel working in the dialysis ward.Another control group of volunteers did not show any positivity. In addition, the correlations of the antibodies against HCV with markers of hepatitis B virus (HBV) and history of transfusion were evaluated.These findings suggest that the patients found to be positive should be dialyzed on separate machines and special precautions must be undertaken to reduce the risk of transmission.

Analysis of methods commonly used for glycopeptide and oxazolidinone susceptibility testing in Enterococcus faecium isolates

The susceptibility to teicoplanin, vancomycin and linezolid of 30 clinical isolates of Enterococcus faecium was tested by Vitek 2, Phoenix, Etest, broth microdilution and disc diffusion tests. The vanA and vanB resistance genes and the 23S rRNA gene G2576T mutation were detected by PCR and PCR-RFLP, respectively. Resistance rates to teicoplanin ranged from 3% for Vitek 2 to 57.6% for the Phoenix test, and those to vancomycin ranged from 56.7% for Vitek 2 to 86.7% for the Phoenix test. Only two out of 25 strains carrying the vanA gene were univocally recognized as the VanA phenotype. The only strain with the G2576T mutation did not carry the vanA gene and showed resistance to linezolid by the disc diffusion, Vitek 2 and broth dilution methods (MIC>8 microg ml(-1)), but was susceptible when tested with the Phoenix test and Etest (MIC<or=4 microg ml(-1)). Therefore, the resistance to glycopeptides and linezolid was not univocally detected by the susceptibility testing methods used in this study.

Diagnostic Value of Cytokine Assays in Cerebrospinal Fluid in Culture-Negative, Polymerase Chain Reaction-Positive Bacterial Meningitis

Abstract Analysis of bacterial DNA using a polymerase chain reaction performed with broad-range eubacterial 16S rDNA primers may yield a diagnosis of bacterial meningitis in cases where Gram staining of cerebrospinal fluid (CFS), antigen detection techniques or culture fail. Since this PCR technique occasionally gives false-positive results due to contamination of samples or laboratory reagents, a study was performed to establish the diagnostic value of assaying concentrations of tumour necrosis factor-α (TNF-α) and interleukin-10 (IL-10) in 90 CSF samples. A high correlation was found between a positive PCR result and the concentrations of TNF-α and IL-10, indicating that cytokine assays may be used as a confirmatory test. The findings suggested that a combination of the PCR technique, amplicon sequencing and assay of TNF-α and IL-10 concentrations in CSF is a reliable and cost-effective procedure for diagnosis of culture-negative bacterial meningitis.