1,720,975 research outputs found
Applicazione della PCR per il riconoscimento di specie in prodotti preparati e trasformati della pesca. Nota 1
No full textAnalisi di mtDNA per l’identificazione di specie ittiche in prodotti congelati e trasformati
No full textValutazione della presenza di Escherichia coli e studio dell’antibiotico-resistenza in campioni di Mytilus galloprovincialis in Campania nel periodo giugno 2012 - agosto 2013
No full textAntimicrobial susceptibility testing for salmonella serovars isolated from food samples: Five-year monitoring (2015–2019)
Get PDFThe continuous collection and analysis of updated data on the antimicrobic resistance among bacterial strains represent the essential core for the surveillance of this problem. The present work aimed to investigate the occurrence of antimicrobial resistance among Salmonella serovars isolated in foods in 2015–2019. A total of 178 Salmonella strains belonging to 39 serovars were tested against 10 antimicrobials. High proportions of Salmonella isolates were resistant to tetracycline (n = 53.9%), ciprofloxacin (n = 47.2%), ampicillin (n = 44.4%), nalidixic acid (n = 42.7%), and trimethoprim-sulfamethoxazole (n = 38.8%). Different resistance rates were recorded among the different serotypes of Salmonella, and S. Infantis, exhibited the highest resistance to antibiotics. A high percentage of strains isolated from poultry, pork, and bovine were resistant to at least one or two antimicrobials. Resistant and multidrug-resistant (MDR) strains were also recorded among the isolates from molluscan shellfish; however, the occurrence of resistant Salmonella strains isolated from this source was significantly lower compared with those reported for poultry, pork, and bovine. The high levels of resistance reported in the present study indicate a potential public health risk. Consequently, additional hygiene and antibiotic stewardship practices should be considered for the food industry to prevent the prevalence of Salmonella in foods
Applicazione della PCR per il riconoscimento di specie in prodotti preparati e trasformati della pesca. Nota 1
No full textPresence of enteric bacterial pathogens in meat samples of wild boar hunted in Campania region, southern Italy
Get PDFWild boars can be infected with several foodborne pathogens which may be transmitted to humans through the consumption of their meat, but currently, data of their prevalence are still limited. The present study aimed to evaluate the presence of enteric pathogens in wild boar meat samples killed in the Campania region. Twenty-eight wild boar meat samples were analyzed for the detection of Salmonella spp, Y. ente-rocolitica, Campylobacter spp., and Shiga-Toxigenic E. coli. Salmonella spp. was detected and isolated in ten samples and after serotyping S. Veneziana, S. Kasenyi, S. Coeln, S. Manhattan, S. Thompson, and S. Stanleyville were identified. Twenty-one meat samples were found to be contaminated with Y. enterocolitica; in 6 samples the ystA and ystB genes were detected simulta-neously, while in 15 only the ystB gene, which characterizes the bacteria belonging to the biotype 1A, was present. Shiga-Toxin producing E. coli was detected in 12 while Campylobacter spp was never detected. In conclusion, due to t
Detection and quantification of campylobacter in foods: New analytic approaches to detect and quantify campylobacter spp. in food samples
Get PDFThe aim of the present study was to develop rapid qualitative and quantitative methods based on the use of Real-Time PCR and Droplet Digital PCR (ddPCR), in order to have reliable techniques to detect and quantify Campylobacter spp. in food samples. The gene 16S-rRNA was used as specific target for Campylobacter spp. Real-Time PCR evaluation assay and a not competitive internal control was ushered in it. To investigate the selectivity of the method, 26 Campylobacter strains and 40 non-Campylobacter strains were tested and in order to verify the application of Real-Time PCR method, 5 pork meat samples were experimentally inoculated with a Campylobacter jejuni strain. Subsequently, dilutions with a bacterial load of Campylobacter jejuni within 10-106 CFU/mL were chosen for the optimization of the ddPCR assay. Lastly, a total of 54 naturally contaminated foods samples were analyzed through molecular (Real-Time PCR and ddPCR) and traditional methods. The Real-Time PCR protocol demonstrated to amplify only the Campylobacter spp. strains and when Campylobacter jejuni was experimentally inoculated in meat samples the pathogen was always detected. The ddPCRs assay allowed to quantify a level of contamination of 10 CFU/mL, but it was unable to quantify levels of 105 – 106 CFU/mL. Lastly, Campylobacter spp. was never detected in the 54 samples tested. In conclusion, the novel analytic approach proposed, based on an initial screening of the samples with Real-Time PCR and then on quantification of Campylobacter spp. with a ddPCR on those positive, represents a quick monitoring tool and, if used correctly, it would allow the implementation of food safety
Hygiene evaluation and microbiological hazards of hunted wild boar carcasses
Get PDFWithin the European Union, different legal requirements must be applied in relation to the circumstances in which wild boar meat is supplied for human consumption. The present study performed from October to December 2019 in the Campania region aimed to monitor microbial contamination on 36 wild boar carcasses eviscerated in premises registered according to the EU Regulation 852/04 (19 animals) and hunters' private houses (17 animals). From each carcass, four areas (ham, back, jowl, and belly), were swabbed using cellulose sponges and analysed for the enumeration of mesophilic bacteria, Enterobacteriaceae and E. coli using the respective culture ISO methods. Real-time PCR was used for the detection of Salmonella spp., Yersinia enterocolitica, Campylobacter spp., and pathogenic E. coli. The presence of pathogenic bacteria was also evaluated in 36 meat samples to better understand the public health risks related to its consumption. Additionally, the presence of Y. enterocolitica was assessed on 36 tonsil samples since, in swine, this pathogen is frequently isolated in this organ. According to the limits settled by the EU Regulation 2073/2005 for pork, carcasses collected from registered premises resulted in more satisfactory mesophilic counts ( 0.05). The overall percentage of wild boars positive per at least one of the enteric pathogens tested was 79.0% (15 out of 19 animals) in registered premises and 82.4% (14 out of 17 animals) in private houses. Pathogenic E. coli was detected in 27 carcasses (75.0%), suggesting that wild boar could play a role as reservoir host and that the meat can cause public health concerns. In conclusion, in the present study an overall high bacterial level was observed on wild boar carcasses, and therefore the need for better slaughter hygiene was demonstrated. Based on the data, the meat resulting from private domestic slaughter may be of lower hygienic quality. The absence of a significant difference observed in the present study may be due to limited sample size and therefore further research should be performed
Determination of the microbiological contamination in minced pork by culture dependent and 16S amplicon sequencing analysis
No full textRoutine evaluation of bacterial contamination in minced pork is still mainly performed by the enumeration of indicator bacteria, including total aerobic colony count and E. coli, using standardized isolation methods. However, the bacterial community structure as well as the effect of the storage time and temperature on the aerobic plate count are largely unknown for this matrix. The aim of the study was to characterize the microbial community in minced pork by 16S rRNA amplicon sequencing compared to classical isolation methods combined with identification by Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI TOF MS) and 16S rRNA gene sequencing. Analysis of 14 unrelated samples showed that total aerobic counts determined at 30 °C and 7 °C showed no significant difference, but the richness was higher on PCA at 30 °C for 7 samples, equal in 5, and higher at 7 °C for 2 samples. Members of the genus Pseudomonas, along with the genera Brochothrix and Carnobacterium were commonly identified among both the mesophilic and psychrotrophic population. Comparing to 16S rRNA amplicon sequencing, some contrasting data were obtained. Except for Brochothrix spp. and Pseudomonas spp., that were abundant and always detected, genera obtained with the two methods in the same sample were not always the same. Comparison of different sample preparation techniques and DNA extraction methods demonstrated also in this matrix that different results on the microbial composition and complexity are obtained. Present data illustrate that the combined isolation and identification of isolates using MALDI TOF MS and 16S gene sequencing and overall community profiling using 16S rRNA amplicon sequencing provides complementary results and yields important insights into the complex relationship between microorganisms in a food
Yersinia enterocolitica detection in pork products: Evaluation of isolation protocols
Get PDFConventional methods for Yersinia enterocolitica detection in food samples are generally considered inadequate. Problems arise from the presence of the so-called “background flora”, coupled to the low contamination level of the pathogen. Since, data on the microbial ecology occurring in competitive microflora are still lacking, MALDI TOF MS was used for strains ‘identification after enrichment in PSB or ITC broths, and after plating on selective CIN medium at different incubation times. SYBR Green Real time PCR was used for the Y. enterocolitica strains’ detection (4/O:3, 1A/O:5) in experimentally contaminated foods, as well as in naturally contaminated samples. A higher number of different bacterial genera (10 on CIN and 18 on PCA) was recorded after enrichment in PSB, whilst enrichment in ITC led to recovery of 6 and 10 genera on CIN and PCA, respectively. Yersiniaceae was the dominant family on the first day of incubation, but on the second day the percentage of isolation considerably decreased. By testing experimentally contaminated samples, substantial difficulties were encountered. The biotype 1A was always detected, whereas strain 4/O:3 proved to be poorly competitive. Based on the data, the enrichment media PSB and ITC, currently proposed for Y. enterocolitica detection, need to be improved to promote a successful pathogen's recovery
- …
