112,255 research outputs found
Il relitto tardo-antico di Mandriola-A
No full textNel contributo viene data notizia preliminare delle prime indagini archeologiche subacquee condotte presso il relitto di Mandriola 1, già noto prima dell'inizio delle indagini condotte nel 2005 ma di cui era stata data solo notizia. La prima campagna ha permesso in particolare di circoscrivere l'area di dispersione dei reperti e il loro inquadramento cronologico: i numerosi frammenti di anfore presenti nel contesto si riferiscono ad Almagro 51 C, corrispondenti al tipo XXIII della classificazione del Keay, e soprattutto ad anfore cilindriche del Basso Impero / Keay XXV, le prime di produzione iberica, le altre africane, entrambi databili tra la metà del IV e la metà del V secolo d.C.
Con il relitto di Mandriola si ripresenta quindi il problema, considerando l’associazione di anfore africane e anfore iberiche con le medesime cronologie, dell’esistenza di porti dove avveniva una ridistribuzione di merci con svariata provenienza : nel nostro caso possiamo ragionevolmente ipotizzare che i porti dove potevano essere smistate merci africane e prodotti provenienti dalle province iberiche possano individuarsi nelle Insulae Baliares, o in alternativa proporre che gli alcuni porti sardi potessero assolvere alla stessa funzione.
Il nostro relitto ripropone dunque l’esistenza di rotte che nell’antichità si muovevano dalla penisola iberica verso Occidente, rotte dirette soprattutto verso i porti centroitalici che servivano direttamente il mercato di Roma ma che non escludevano altri scali, tra cui quelli della Sardegna. A conferma di ciò sta la grossa quantità di anfore dell’Iberia recuperati in diversi centri costieri della Sardegna: si citano ad esempio i contesti di Turris Libisonis e dell’area paleocristiana di Columbaris, presso la città di Cornus, nei quali, tra i contenitori iberici si attesta una maggiore presenza proprio di anfore Almagro 51 C
Multidrug resistant and Methicillin Resistant Staphylococcus aureus (MRSA) isolated from raw sheep’s milk
No full textMultidrug resistant (MDR) and Methicillin Resistant Staphylococcus aureus (MRSA) contamination in milk and dairy products can origin from animals, farm environment, from human in contact with animals or food handlers. Therefore, milk and dairy products could represent a potential source of antibiotic resistant S. aureus strains that could reach human through the food chain. Most of the reports on the occurrence and characterization of MDR S. aureus and MRSA refer to dairy cows, while little information is cu ently available on st ains isolated f om s eep’s milk. T e aim of t e p esent study was to evaluate the presence of MDR S. aureus and MRSA harboring mecA and mecC genes in aw s eep’s milk. enotypic esistance to antibiotics and t e p esence of t e genetic determinants were also investigated. Bulk tank milk samples and milking machines filters were collected from 17 Sardinian dairy sheep farms. In addition, 3 filters from one cheese-making plant collecting milk from the investigated farms were sampled. The detection of Coagulase Positive Staphylococci was performed according to ISO 6888-
1:1999 and the potential presence of MRSA assessed using ChromID MRSA Smart agar plates. Isolates were submitted to PCR for species identification. Minimum Inhibitory Concentration (MIC) for Ampicillin (AM), Cephalothin (CEF), Cefoxitin (FOX), Erythromycin (E), Oxacillin (OX), Penicillin (P), Tetracycline (TE) and Vancomycin (VA) was determined using broth microdilution method (CLSI M07,M100, 2015). The detection of the genes mecA, mecC, blaZ, ermA-B-C, vanA, tetK-M-S-W encoding antibiotic resistance was performed as previously described (Spanu et al., 2014). In this study, 118
S. aureus strains were collected, 65 strains from 17 positive milk filters, 38 from 7 bulk tank milk samples and 15 from cheese-making plant filters. Twelve strains (10.2%) were resistant at least to one of the β-lactam antibiotics tested and 6 isolates showed multiple resistance against AM, FOX, OX and/or P. Among these, 3 strains were identified as MRSA with MIC values of 16-32 μg/mL for OX and 64 μg/mL for FOX. Interestingly, 2 out of 3 MRSA were also resistant to E (8 μg/mL), despite only 1 strain carried blaZ, mecA, mecC and ermB-C genes. All the isolates were susceptible to CEF and VA and did not carry the correspondent resistant genes. On the other hand, although resistance to TE was not found, 15 and 7 S. aureus strains carried tetM and tetK genes, respectively. The results of the present study suggest the emergence of MDR S. aureus also in small ruminants dairy chain which pose a potential public health hazard for the spreading of MRSA strains
Lucerne da Antinoupolis. Scavi della necropoli nord 1965-1966.
No full textIl volume prende in rassegna 567 lucerne pertinenti agli scavi condotti negli anni 1965 e 1966 dall’Istituto Papirologico «G. Vitelli» di Firenze presso la Necropoli Nord di Antinoupolis, diretti da S. Bosticco e da M. Manfredi. Si tratta di un repertorio praticamente unico nella storia degli studi per il periodo compreso tra il V ed il VII sec. d.C
PREVALENCE AND IDENTIFICATION OF VIBRIO SPP. ISOLATED ON AQUACULTURED GILTHEAD SEA BREAM
No full textThe aim of the study was to investigate the prevalence of Vibrio spp isolated from gilthead sea bream (Sparus aurata) farmed on sea cages and to identify and characterize the pathogen by molecular techniques. Eighty fish were collected from two hatcheries located on the North-Est Sardinian Mediterranean coast, and microbiological analysis were performed on different body parts such as skin, gills, muscle and intestinal tract. Subsequently 100 pure colonies with typical morphology and phenotypic characteristics were selected and submitted to the molecular identification. The analysis on the prevalence of Vibrio spp showed the effect of the hatchery rearing system (P<0.001), of the date of sampling (P<0.001), and of the body part (P<0.001). All the strains selected were confirmed to be members of the genus Vibrio spp by the molecular method/techinique/identification, whereas the rpoA gene sequence analyses allowed to identify 89 strains belonging to the species Vibrio harveyi, 6 to V. diabolicus, 2 to V. parahaemolyticus and 1 to V. mediterranei
Le grandi ville aristocratiche tardoantiche nella Gallia Belgica. Problemi di acculturazione e di innovazione delle élites gallo-romane (III - V secolo d.C.)
No full textLa ricerca nasce con l’obiettivo di fornire una visione d’insieme delle grandi ville aristocratiche tardoantiche della Gallia Belgica e, in modo specifico, dell’area trevera e mediomatrice. Il lavoro ha previsto il censimento sistematico delle ville note attraverso la bibliografia esistente (a cui si sono aggiunti civitates, mausolei, santuari, fana, vici connessi alle ville stesse), parallelamente è stata predisposta un’apposita piattaforma Q-GIS finalizzata alla contestualizzazione topografica dei siti e alla loro analisi distributiva. Sempre nella stessa piattaforma le informazioni sono state caricate in un database relazionale che ha consentito una più agile gestione dei dati. La ricerca ha riguardato 104 siti (62 sono ville - di cui 46 inserite nel presente catalogo cartaceo -, i restanti siti sono stati archiviati nel database Q-GIS) suddivisi nei moderni Stati di Francia, Germania, Granducato del Lussemburgo, Belgio e Olanda e collocati in un arco cronologico che va dalla fine del III agli inizi del V secolo d.C
Antibiotic Resistance Traits and Molecular Subtyping of Staphylococcus aureus Isolated from Raw Sheep Milk Cheese
No full textThe main objective of the present research was to evaluate the antibiotic resistance profiles of Staphylococcus aureus isolated from raw sheep milk cheese. A total of 150 strains were isolated from curd cheese samples and identified as S. aureus. The survey on antibiotic resistance was carried out on 47 strains, selected among isolates showing differences in the banding pattern after Pulsed Field Gel Electrophoresis (PFGE) screening or, belonging at the same pulsotype but isolated from different cheese samples. On selected strains antimicrobial resistance against ampicillin, penicillin, cloxacillin, tetracycline, erythromycin and vancomycin was assessed by broth microdilution method. The presence of the genes coding for antibiotic resistance and virulence factors (agr alleles, sea-see and tst) was also investigated by PCR. Thirty-one isolates belonging to agrI and agrIII groups carried at least one gene coding for enterotoxins or toxic shock syndrome toxin. Approximately 60% of the selected strains were susceptible to the tested antibiotics. Twelve out of 47 isolates showed multiple resistance against ampicillin and penicillin. Only one strain, represented by a unique PFGE profile showed simultaneous resistance to ampicillin, penicillin and cloxacillin. Single resistance against tetracycline was found in 5 isolates belonging to 2 different pulsotypes. The results of the present study suggest that the recovery of S. aureus resistant strains in raw milk cheese samples is quite common but it is limited to few antibiotic classes, mainly beta-lactams and tetracyclines. None of the strains showed resistance to erythromycin and vancomyci
Prevalenza di Staphylococcus aureus in formaggi ovini a latte crudo e profilo enterotossigenico
No full textOccurrence and traceability of Listeria monocytogenes strains isolated from sheep’s milk cheese-making plants environment
No full textThe aim of the study was to conduct an extensive survey on Listeria monocytogenes and Listeria spp. environmental contamination in 13 cheese-making plants. A total of 409 environmental and food samples were collected during years 2011–2013. Listeria spp. contamination was observed in all the facilities, while L. monocytogenes was recovered from 12 facilities with a prevalence ranging between 3.0% and 22.6%. Floor drains were the most contaminated sampling sites (48.8% of positive samples), serving as harbourage site for subsequent contamination. Out of 616 isolates, 277 (45.0%) were Listeria innocua, 274 (44.5%) L. monocytogenes, 41 (6.6%) Listeria ivanovii, 14 (2.3%) Listeria welshimeri and 10 (1.6%) Listeria gravyi. Serotyping carried out by PCR and agglutination method for L. monocytogenes revealed that 169 strains (61.7%) were serotype 1/2a, 65 (23.7%) 4b, 20 (7.3%) 1/2b, 10 (3.6%) 3a, 7 (2.5%) 1/2c and 3 (1.1%) 3b. PFGE conducted on L. monocytogenes isolates using AscI and ApaI restriction enzymes, yielded 6 clusters. Two predominant PFGE clusters were observed including respectively 36 and 32 strains. Within cheese-making plants, L. monocytogenes showed wide variability with strains distributed up to 4 different clusters. Pulsotypes isolated from raw milk filter were never detected in the processing environment, indicating that the contamination originated from sources other than raw milk. The isolation of strains with similar profile from different sampling sites, within and among cheese-making plants, indicated the possible transfer of L. monocytogenes contamination along production lines and from one facility to another. Strains recovered from food were confirmed as originating from the processing environment
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