Listeria monocytogenes: biofilm in food processing

Contamination of food by Listeria monocytogenes (L.m) frequently occurs in food processing environments, where cells persist due to their ability to attach to surfaces. L.m is able to attach and colonize environmental surfaces by producing a three-dimensional matrix of extracellular polymeric substances (EPS) called biofilm; such structures are dynamic systems. Once established, biofilms can serve as a source of product contamination. Moreover, L.m in the biofilm state shows a reduced susceptibility to antimicrobial agents. The present review focuses on L.m biofilms in food processing environments. In addition, some aspects of biofilm control and eradication are highlighted

Resistance Patterns, mcr-4 and OXA-48 Genes, and Virulence Factors of Escherichia coli from Apennine Chamois Living in Sympatry with Domestic Species, Italy

The aim of this study was to determine and characterize potential resistance mechanisms against selected Critically Important Antibiotics in Escherichia coli isolates collected from wild and domestic ruminants living in the Maiella National Park, in Central Italy. A total of 38 isolates were obtained from red deer, Apennine chamois, cattle, sheep, and goats grazing in lands with different levels of anthropic pressure. Antimicrobial susceptibility was determined by Minimal Inhibitory Concentration testing, showing phenotypic resistance to colistin, meropenem, or ceftazidime in 9 isolates along with one bacterial strain being resistant to three of the tested antibiotics. In addition, the biomolecular assays allowed the amplification of the genes conferring the colistin (mcr-4), the carbapenems (OXA-48), penicillins and cephalosporins (TEM, SHV, CMY-1, CMY-2) resistance. In order to describe the potential pathogenicity of isolates under study, virulence genes related to Shiga toxin-producing (STEC) and enteropathogenic (EPEC) pathovars were identified. This study is the first report of mcr-4 and OXA-48 genes in resistant E. coli harboring virulence genes in Italian wildlife, with special regard to Apennine chamois and red deer species. The multidisciplinary approach used in this study can improve the early detection of emerging antibiotic resistance determinants in human-animal-environment interfaces by means of wildlife monitoring

BIOMOLECULAR IDENTIFICATION OF METHICILLIN-RESISTANT STRAINS OF STAPHYLOCOCCUS AUREUS (MRSA) ISOLATED FROM MEAT AND MEAT PROCESSING ENVIRONMENTS

371 samples from meat and meat-environments were collected and examined for the detection of methicillin-resistant Staphylococcus aureus (MRSA). The structural gene for penicillin-binding protein 2a (mecA gene), was amplified by PCR and detected by agarose gel electrophoresis. 96 samples (25.8%), contained S. aureus and 2 of them (2.08%) were mecA positive. Further assays are necessary to evaluate the spread of MRSA in food and food-environments

Potential clinical implications of CD4+CD26high T cells for nivolumab treated melanoma patients

Background Nivolumab is an anti-PD1 antibody that has dramatically improved metastatic melanoma patients’ outcomes. Nevertheless, many patients are resistant to PD-1 inhibition, occasionally experiencing severe of-target immune toxicity. In addition, no robust and reproducible biomarkers have yet been validated to identify the correct selection of patients who will beneft from anti-PD-1 treatment avoiding unwanted side efects. However, the strength of CD26 expression on CD4+ T lymphocytes permits the characterization of three subtypes with variable degrees of responsiveness to tumors, suggesting that the presence of CD26-expressing T cells in patients might be a marker of responsiveness to PD-1-based therapies. Methods The frequency distribution of peripheral blood CD26-expressing cells was investigated employing multiparametric fow cytometry in 69 metastatic melanoma patients along with clinical characteristics and blood count parameters at baseline (W0) and compared to 20 age- and sex-matched healthy controls. Percentages of baseline CD4+CD26high T cells were correlated with the outcome after nivolumab treatment. In addition, the frequency of CD4+CD26high T cells at W0 was compared with those obtained after 12 weeks (W1) of therapy in a sub-cohort of 33 patients. Results Circulating CD4+CD26high T cells were signifcantly reduced in melanoma patients compared to healthy subjects (p=0.001). In addition, a signifcant association was observed between a low baseline percentage of CD4+CD26high T cells (<7.3%) and clinical outcomes, measured as overall survival (p=0.010) and progression-free survival (p=0.014). Moreover, patients with clinical beneft from nivolumab therapy had signifcantly higher frequencies of circulating CD4+CD26high T cells than patients with non-clinical beneft (p=0.004) at 12 months. Also, a higher pre-treatment proportion of circulating CD4+CD26high T cells was correlated with Disease Control Rate (p=0.014) and best Overall Response Rate (p=0.009) at 12 months. Interestingly, after 12 weeks (W1) of nivolumab treatment, percentages of CD4+CD26high T cells were signifcantly higher in comparison with the frequencies measured at W0 (p<0.0001), aligning the cell counts with the ranges seen in the blood of healthy subjects

baseline predictive factors for efficacy of anti pd1 used in first line in melanoma patients an italian melanoma intergroup study

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Safety of extended interval dosing immune checkpoint inhibitors: a multicenter cohort study

BACKGROUND: Real-life spectrum and survival implications of immune-related adverse events (irAEs) in patients treated with extended interval dosing (ED) immune checkpoint inhibitors (ICIs) are unknown. METHODS: Characteristics of 812 consecutive solid cancer patients who received at least 1 cycle of ED monotherapy (pembrolizumab 400 mg Q6W or nivolumab 480 mg Q4W) after switching from canonical interval dosing (CD; pembrolizumab 200 mg Q3W or nivolumab 240 mg Q2W) or treated upfront with ED were retrieved. The primary objective was to compare irAEs patterns within the same population (before and after switch to ED). irAEs spectrum in patients treated upfront with ED and association between irAEs and overall survival were also described. RESULTS: A total of 550 (68%) patients started ICIs with CD and switched to ED. During CD, 225 (41%) patients developed any grade and 17 (3%) G3 or G4 irAEs; after switching to ED, any grade and G3 or G4 irAEs were experienced by 155 (36%) and 20 (5%) patients. Switching to ED was associated with a lower probability of any grade irAEs (adjusted odds ratio [aOR] = 0.83, 95% confidence interval [CI] = 0.64 to 0.99; P = .047), whereas no difference for G3 or G4 events was noted (aOR = 1.55, 95% CI = 0.81 to 2.94; P = .18). Among patients who started upfront with ED (n = 232, 32%), 107 (41%) developed any grade and 14 (5%) G3 or G4 irAEs during ED. Patients with irAEs during ED had improved overall survival (adjusted hazard ratio [aHR] = 0.53, 95% CI = 0.34 to 0.82; P = .004 after switching; aHR = 0.57, 95% CI = 0.35 to 0.93; P = .025 upfront). CONCLUSIONS: Switching ICI treatment from CD and ED did not increase the incidence of irAEs and represents a safe option also outside clinical trials