Identification and characterization of a spreadable IncI1 plasmid harbouring a blaCTX-M-15 gene in an Italian human isolate of Salmonella serovar Napoli.

Salmonella enterica subsp. enterica serovar Napoli (S. Napoli) ranks among the top serovars causing human infections in Italy, although not common in other European countries. Isolates are generally pan-susceptible or resistant to aminoglycosides only, however data on antimicrobial resistance genes in strains of S. Napoli are limited. Recently an isolate encoding resistance to third generation cephalosporins was reported. This study aimed to characterize plasmid-encoded cephalosporin resistance due to the blaCTX-M-15 gene in a human S. Napoli isolate in Italy, and to investigate plasmid stability over time. S. Napoli 16/174478 was confirmed to be ESBL-producing. The blaCTX-M-15 gene was shown to be located on an IncI1α plasmid of 90,272 bp (50.03 GC%) encoding for 107 coding sequences (CDS). The plasmid was successfully transferred by conjugation to an E. coli 1816 recipient strain (conjugation frequency 3.9 × 10-2 transconjugants per donor). Transconjugants were confirmed to carry the IncI1α plasmid, and to be ESBL-producing strains as well. Moreover, transconjugant colonies maintained the plasmid for up to 10 passages. The identification of S. Napoli isolates able to produce ESBLs is of great concern, as this pathogen is frequently associated with invasive infections and a higher risk of bacteraemia, and its reservoir has not yet been clearly identified.

The challenging task to select Salmonella target serovars in poultry: the Italian point of view.

According to the European Food Safety Authority (EFSA) and European Centre for Disease Prevention and Control (ECDC) annual report, human salmonellosis is mostly related to consumption of contaminated poultry products. Since 2003 in Europe, the Salmonella serovars considered relevant for human health and subject to control in breeding hens of Gallus gallus are: S. Enteritidis, S. Typhimurium (including the monophasic variant), S. Infantis, S. Hadar and S. Virchow. Herein, we investigated the Italian epidemiological situation from 2016 to 2018, comparing Salmonella serovar distributions in humans and poultry, in order to identify the target Salmonella serovars that, if controlled, would potentially have the largest public health impact in Italy. The results showed that control of S. Virchow and S. Hadar does no longer seem to be a priority in Italy and that S. Napoli and S. Derby, which are not included in the group of EU target serovars, are among the most frequent serovars isolated from humans in Italy. While S. Derby has its main reservoir in pigs, S. Napoli does not have a specific reservoir. However, because this serovar is frequently isolated from breeding poultry flocks and is characterised by causing severe human illness, it is a potential target Salmonella serovar in breeding hens of Gallus gallus in Italy.

Comparative genomic analysis reveals high intra-serovar plasticity within Salmonella Napoli isolated in 2005-2017.

BACKGROUND: Salmonella enterica subsp. enterica serovar Napoli (S. Napoli) is among the top serovars causing human infections in Italy, although it is relatively uncommon in other European countries; it is mainly isolated from humans and the environment, but neither the reservoir nor its route of infection are clearly defined. This serovar is characterized by high genomic diversity, and molecular evidences revealed important similarities with typhoidal serovars. RESULTS: 179 S. Napoli genomes as well as 239 genomes of typhoidal and non-typhoidal serovars were analyzed in a comparative genomic study. Phylogenetic analysis and draft genome characterization in terms of Multi Locus Sequence Typing (MLST), plasmid replicons, Salmonella Pathogenicity Islands (SPIs), antimicrobial resistance genes (ARGs), phages, biocide and metal-tolerance genes confirm the high genetic variability of S. Napoli, also revealing a within-serovar phylogenetic structure more complex than previously known. Our work also confirms genomic similarity of S. Napoli to typhoidal serovars (S. Typhi and S. Paratyphi A), with S. Napoli samples clustering primarily according to ST, each being characterized by specific genomic traits. Moreover, two major subclades of S. Napoli can be clearly identified, with ST-474 being biphyletic. All STs span among isolation sources and years of isolation, highlighting the challenge this serovar poses to define its epidemiology and evolution. Altogether, S. Napoli strains carry less SPIs and less ARGs than other non-typhoidal serovars and seldom acquire plasmids. However, we here report the second case of an extended-spectrum ß-lactamases (ESBLs) producing S. Napoli strain and the first cases of multidrug resistant (MDR) S. Napoli strains, all isolated from humans. CONCLUSIONS: Our results provide evidence of genomic plasticity of S. Napoli, highlighting genomic similarity with typhoidal serovars and genomic features typical of non-typhoidal serovars, supporting the possibility of survival in different niches, both enteric and non-enteric. Presence of horizontally acquired ARGs and MDR profiles rises concerns regarding possible selective pressure exerted by human environment on this pathogen.

metaSPARSim: a 16S rRNA gene sequencing count data simulator.

BACKGROUND: In the last few years, 16S rRNA gene sequencing (16S rDNA-seq) has seen a surprisingly rapid increase in election rate as a methodology to perform microbial community studies. Despite the considerable popularity of this technique, an exiguous number of specific tools are currently available for proper 16S rDNA-seq count data preprocessing and simulation. Indeed, the great majority of tools have been developed adapting methodologies previously used for bulk RNA-seq data, with poor assessment of their applicability in the metagenomics field. For such tools and the few ones specifically developed for 16S rDNA-seq data, performance assessment is challenging, mainly due to the complex nature of the data and the lack of realistic simulation models. In fact, to the best of our knowledge, no software thought for data simulation are available to directly obtain synthetic 16S rDNA-seq count tables that properly model heavy sparsity and compositionality typical of these data. RESULTS: In this paper we present metaSPARSim, a sparse count matrix simulator intended for usage in development of 16S rDNA-seq metagenomic data processing pipelines. metaSPARSim implements a new generative process that models the sequencing process with a Multivariate Hypergeometric distribution in order to realistically simulate 16S rDNA-seq count table, resembling real experimental data compositionality and sparsity. It provides ready-to-use count matrices and comes with the possibility to reproduce different pre-coded scenarios and to estimate simulation parameters from real experimental data. The tool is made available at http://sysbiobig.dei.unipd.it/?q=Software#metaSPARSimand https://gitlab.com/sysbiobig/metasparsim. CONCLUSION: metaSPARSim is able to generate count matrices resembling real 16S rDNA-seq data. The availability of count data simulators is extremely valuable both for methods developers, for which a ground truth for tools validation is needed, and for users who want to assess state of the art analysis tools for choosing the most accurate one. Thus, we believe that metaSPARSim is a valuable tool for researchers involved in developing, testing and using robust and reliable data analysis methods in the context of 16S rRNA gene sequencing.

Different Resolution Power of Multilocus Variable-Number Tandem Repeat Analysis and Whole-Genome Sequencing in the Characterization of S. 1,4,[5],12:i:- Isolates.

Salmonella enterica serovar 1,4,[5],12:i:- has emerged over the last two decades as one of the most common serovars causing human salmonellosis in Europe. It is supposed to originate from Salmonella enterica serovar Typhimurium due to antigenic and genotypic similarities between the two serovars. Due to the high level of similarity, the multilocus variable-number tandem repeat analysis (MLVA) protocol designed for Salmonella Typhimurium routine typing is commonly used also for the characterization of S. 1,4,[5],12:i. Nevertheless, the Salmonella Typhimurium-based MLVA protocol often shows poor discriminatory power for S. 1,4,[5],12:i. Indeed, only a limited number of MLVA profiles have been described for S. 1,4,[5],12:i:-. Moreover, based on the MLVA clustering, S. 1,4,[5],12:i:- is supposed to display high clonality. The aim of the present work was to assess whether the five loci of Salmonella Typhimurium investigated by MLVA are sufficiently accurate to correctly assign S. 1,4,[5],12:i:- isolates. For this purpose, 38 epidemiologically unrelated S. 1,4,[5],12:i:- were subjected to whole-genome sequencing. Isolates were selected among a collection of monophasic strains isolated in Italy from different sources over the period 2014-2016 and belonging to the five most commonly detected MLVA profiles. Results confirmed the possible clonality for S. 1,4,[5],12:i:- serovar in the light of the scarce difference observed in terms of single-nucleotide polymorphisms (SNPs) among investigated isolates. Nevertheless, unrelated isolates on the basis of the difference of SNP number were characterized as indistinguishable by MLVA profile, thus suggesting an insufficient resolution of MLVA. Hence, we can conclude that MLVA-based approach does not seem a valuable proxy to deepen into the epidemiological relationship among S. 1,4,[5],12:i:- isolates. These evidences can be useful to avoid incorrect assignment especially when surveillance data are used for outbreak investigations.

State of art of nanotechnology applications in the meat chain: A qualitative synthesis.

BACKGROUND: Nanotechnology is a promising area in industry with a broad range of applications including in the agri-food sector. Several studies have investigated the potential benefits deriving from use of nanomaterials in the context of the whole food chain drawing scenarios of benefits but also potential for concerns. Among the agri-food sector, animal production has potential for nanomaterial application but also for safety concerns due to the possibility of nanomaterial accumulation along the farm-to-fork path. Scope and Approach: The aim of this work was to define the state of the art of nanomaterial applications in the animal production sector by assessing data belonging to recently publishes studies. To do this, a qualitative synthesis approach was applied to build a fit-for-purpose framework and to summarise relevant themes in the context of effectiveness, feasibility and health concerns. Key findings and conclusions: Nanomaterials have potential for use in a wide range of applications from feed production and farming to food packaging, including several detection tools designed for the benefit of consumer protection. The current high degree of variability in nanomaterials tested and in study designs impairs external validation of research results. Further research is required to clearly define which safe nanomaterial applications have the potential to reach the market.

Toxoplasma gondii infection and food consumption: A systematic review and meta-analysis of case-controlled studies.

BACKGROUND: Toxoplasmosis is a zoonotic disease causing severe symptoms in pregnant women and immunocompromised individuals. On average, worldwide, around 30% of people are seropositive. The oral transmission route is of great significance and food, particularly meat, is an important transmission vehicle for T. gondii. However, the role of different food matrices is debated. OBJECTIVES: The aim of this review was to assess the risk of humans developing acute T. gondii infection via the foodborne route. STUDY ELIGIBILITY CRITERIA: Case-control studies including acute cases of T. gondii infection were included after literature searches, without time limits, in several databases. All studies estimating the risk of acquiring T. gondii infection after consumption of specific food categories were included. RESULTS: Three risk factors proved to be significantly associated with acute T. gondii infection in humans: consumption of raw/undercooked meat, Odds Ratio (OR) 3.44 (1.29-9.16), consumption of raw/undercooked beef, OR 2.22 (1.57-3.12), and consumption of raw/undercooked sheep meat, OR 3.85 (1.85-8.00). Consumption of raw/undercooked pork, raw eggs, and unpasteurized milk proved to be non-significant risk factors. LIMITATIONS: Limitations in the present review and meta-analysis are due to the low number of case-control studies available for analysis and the lack of a search strategy targeting gray literature. CONCLUSION: Consumption of raw/undercooked beef and sheep meat are important risk factors for T. gondii infection. Their consumption should be avoided in order to prevent toxoplasmosis, particularly by those in at-risk categories, including pregnant women. The review protocol is registered in PROSPERO database (CRD42016043295).

Undeclared animal species in dry and wet novel and hydrolyzed protein diets for dogs and cats detected by microarray analysis.

BACKGROUND: Although the European Pet Food Industry Federation (FEDIAF) stated that labels must be accurate and provide detailed information on the ingredients, mislabeling of pet food has been documented by several authors. This phenomenon is of particular concern when related to products used as elimination diets for the diagnosis of adverse food reaction (AFR) in dogs and cats because the presence of undeclared ingredients may negatively interfere with the trial and prevent the veterinarian from making an appropriate diagnosis. The aim of this study was to shed light upon the problem of contamination and mislabeling in both dry and wet novel protein diets (NPDs) and hydrolyzed protein diets (HPDs) using a microarray-based commercial kit which tests for the presence of 19 animal species. RESULTS: Of the 40 analyzed products (9 dry NPDs, 22 wet NPDs, 6 dry HPDs and 3 wet HPDs), ten presented a content that correctly matched the label, while five did not contain the declared animal species, twenty-three revealed the presence of undeclared animal species, and two had a vague label that did not allow the evaluation of its accuracy. The most frequently contaminants identified in both dry and wet pet foods were pork, chicken and turkey. The presence of undeclared animal species was higher in dry than wet pet foods; furthermore, a lower number of contaminating animal species was identified in HPDs than NPDs (4 vs 10), and a lower number of contaminated HPDs (6 out of 9, 67%) than contaminated NPDs was detected (24 out of 31, 77%). Thirteen out of 14 brands tested presented at least one mislabeled product. CONCLUSIONS: Mislabeling seems to be a widespread issue in pet foods used as elimination diets. Contamination can occur in all types of products used for the purpose, although dry NPDs are the main issue. Due to the high risk of contamination, particular attention should be given to both the selection of raw material suppliers and the production process.

Comparison between Salmonella enterica Serotype Enteritidis Genotyping Methods and Phage Type.

A quantitative comparison between discriminatory indexes and concordance among multilocus variable-number tandem-repeat analysis (MLVA), pulsed-field gel electrophoresis (PFGE), automated ribotyping, and phage typing has been performed, testing 238 Salmonella enterica serotype Enteritidis isolates not epidemiologically correlated. The results show that MLVA is the best choice, but each typing method provides a piece of information for establishing clonal relationships between the isolates.

Food safety and hygiene lessons in the primary school: implications for risk-reduction behaviors.

OBJECTIVE: This study describes an effective educational program to improve children's knowledge about characteristics of microorganisms and food contamination, and their personal hygiene behaviors. MATERIALS AND METHODS: Between November 2011 and March 2012, a health campaign, targeted at fifth-grade students of 12 public primary compulsory schools, was conceived. Participants were divided into two classes, a theoretical class and a practical class based on two different teaching approaches. To address children's knowledge and behaviors on the program topics and to monitor the effectiveness of the health campaign on changing pre-existent concepts and habits, pre- and post-intervention questionnaires were administered both to students and parents. Poisson and binomial mixed models were performed. RESULTS: Two hundred forty-nine children were enrolled. Results show an overall improvement in children's knowledge both for the practical and theoretical classes (incident risk ratios [IRRs]: 1.2, 95% confidence interval (CI) 1.1-1.2, p<0.001 and 1.1, 95% CI 1.0-1.1, p<0.001, post- versus pre-intervention). The same effect was observed for children's behavior, comparing post- versus pre-intervention for both groups (IRRs were 3.4, 95% CI 2.2-5.2, p<0.001 and 3.2 95% CI 1.9-5.5, p<0.001). CONCLUSION AND APPLICATIONS: The methodology described in this article might be usefully adopted to conduct food safety classes, contributing to the amelioration of children's awareness on food related risks and leading to significant benefit for primary prevention.

Molecular characterization of Salmonella enterica serovar 4,[5],12:i:- DT193 ASSuT strains from two outbreaks in Italy.

Salmonella enterica subsp. enterica serovar 4,[5],12:i:- DT193 is recognized as an emerging monophasic variant of Salmonella Typhimurium in many European countries. Resistance to ampicillin, streptomycin, sulphonamides, and tetracycline (R-type ASSuT) is described as one of the most common profiles of resistance within this clone. Recently, strains presenting such features were isolated from two unrelated outbreaks in Italy. Strains were characterized by pulsed-field gel electrophoresis (PFGE), performed with XbaI, BlnI, and SpeI, and multiple-locus variable-number tandem repeat analysis (MLVA). XbaI-PFGE showed strains related to the two outbreaks as indistinguishable. Conversely, both BlnI-PFGE and MLVA characterized the strains related the two outbreaks as different. XbaI-PFGE identified two profiles, differing by one band, within strains isolated from one of the two outbreaks. Also BlnI-PFGE and MLVA generated different profiles among the strains related to that outbreak. Combining the PFGE profiles obtained by XbaI and BlnI and comparing them with the MLVA profiles, the two methods grouped the same isolates based on identity. Moreover, genomic deletions of the genes included in the operon fljAB, the flanking iroB gene, and the closely located STM2757 gene were investigated. For all strains, the same profile of deletion characterized by the absence of fljA, fljB, and hin genes and the presence of STM2757 and iroB genes was identified. This profile of deletion represents a mixture between two profiles of Salmonella 4,[5],12:i:- described as the "Spanish" and the "U.S." clones. This study demonstrated that although strains of Salmonella 4,[5],12:i:- DT193 ASSuT are highly clonal, minor differences between strains may be seen during the same outbreak by using in parallel PFGE with different restriction enzymes, MLVA, and the analysis of molecular markers related to the operon fljAB. The combination of these different molecular approaches was essential to clarify the epidemiological relationship among the strains.

Molecular characterization of "inconsistent" variants of Salmonella Typhimurium isolated in Italy.

Salmonella 4,[5],12:i:- is a variant of Salmonella Typhimurium, which lacks the expression of phase-2 flagellar antigen, generally associated with the deletion of the fljB gene. Additional mechanisms involving the fljAB operon ( fljA, fljB, and hin genes) lead to the lack of expression of phase-2 flagellar antigens also in Salmonella strains harboring the fljB gene. For 20 S. 4,[5],12:i:- strains, defined as "inconsistent" Salmonella Typhimurium variants since they had phenotypically behaved as monophasic, even though the fljB gene was conserved, the fljAB operon was characterized in order to explain the ineffective expression of the phase-2 flagellar antigen. The monophasic phenotype for a first group of strains (9) was likely due to the absence of the hin gene, leading to the inhibited switch between the expression of phase-1 and phase-2 flagellar genes. For a second group of strains (5), the monophasic phenotype could be attributed to nonconservative point mutations identified in fljA and hin genes, which could hamper the proper expression of invertase gene and the fljA, acting as repressor of the phase-1 flagellar gene. Finally, for a last group of inconsistent strains (6), a plausible reason for their monophasic phenotype was not found, since the genes involved in the expression of phase-2 flagellar antigen were fully conserved. Moreover, the collection of inconsistent Salmonella Typhimurium isolates investigated were characterized by distinct molecular profiles, as demonstrated by multiple-locus variable-number tandem repeat analysis, and phenotype variability, as demonstrated by phage-typing. This study highlights the usefulness of investigating the entire fljAB operon when a definitive identification of the monophasic or biphasic status of Salmonella Typhimurium strains is needed (for instance, in the context of epidemiological investigations aimed to identify the relatedness among strains).

Effect of TiO2 Nanoparticle on Bioaccumulation of ndl-PCBs in Mediterranean Mussels (Mitilus galloprovincialis).

The interaction of nanomaterials with pollutants in the marine environment might alter bioavailability, as well as toxicity, of both nanomaterials and pollutants, representing a risk, not only for marine organisms, but also for consumers through the marine food chain.The aim of this study was to evaluate the effect of titanium dioxide nanoparticles (TiO2NPs) in terms of bioaccumulation and toxicity on Mediterranean mussels (Mytilus galloprovincialis) exposed to six-indicator non-dioxin-like polychlorinated biphenyls (ndl-PCBs). Mussels were exposed to ndl-PCBs (20 µg/mL) (groups 3-4) or to a combination of ndl-PCBs (20 µg/mL) and TiO2NPs (100 µg/mL) (groups 5-6) for four consecutive days. TiO2NPs was detected in groups 5-6 (3247 ± 567 and 1620 ± 223 µg/kg respectively), but their presence did not affect ndl-PCBs bioaccumulation in mussels. In fact, in groups 3-4, the concentration of ndl-PCBs (ranging from 3818.4 ± 166.0-10,176 ± 664.3 µg/kg and 2712.7 ± 36.1-9498.0 ± 794.1 µg/kg respectively) was not statistically different from that of groups 5-6 (3048.6 ± 24.0-14,635.9 ± 1029.3 and 5726.0 ± 571.0-9931.2 ± 700.3 µg/kg respectively). Histological analyses showed alterations to the structure of the gill tissue with respect to the control groups, with more severe and diffuse dilatation of the central hemolymphatic vessels of the gill lamellae in groups 5-6 (treated with TiO2NPs and ndl-PCBs concurrently) compared to groups 3-4 (ndl-PCBs only). Finally, in mussels submitted to a seven-day depuration process, most TiO2NPs were eliminated, and NPs had a synergistic effect on ndl-PCBs elimination; as a matter of fact, in groups 5-6, the percentage of concentration was statically inferior to the one observed in groups 3-4. In any case, consumers might be exposed to TiO2NPs and ndl-PCBs (both concurrently and separately) if edible mussels, harvested in a contaminated environment, are consumed without a proper depuration process.

Assessing the mechanisms of multi-drug resistant non-typhoidal Salmonella (NTS) serovars isolated from layer chicken farms in Nigeria.

BACKGROUND: In Nigeria, there have been reports of widespread multiple antimicrobial resistance (AMR) amongst Salmonella isolated from poultry. To mitigate the impact of mortality associated with Salmonella on their farms, farmers resort to the use of antimicrobials without sound diagnostic advice. We conducted this study to describe the AMR patterns, mechanisms and genetic similarities within some Salmonella serovars isolated from different layer farms. METHOD: We determine the AMR profiles of two hundred Salmonella isolates, selected based on frequency, serovar, and geographical and sample type distribution. We also assessed the mechanisms of multi-drug resistance for specific genetic determinants by using PCR protocols and gene sequence analysis. Pulsed-field gel electrophoresis (PFGE) was conducted on seven selected serovars to determine their genetic relatedness. RESULTS: Of 200 isolates, 97 (48.5%) revealed various AMR profiles, with the multiple antibiotic resistance (MAR) index ranging from 0.07-0.5. Resistance to ciprofloxacin was common in all the multi-drug resistant isolates, while all the isolates were susceptible to cefotaxime, ceftazidime, and meropenem. Genotypic characterization showed the presence of resistance genes as well as mutations in the nucleotide genes with subsequent amino acid substitutions. Fifteen isolates (43%) of S. Kentucky were indistinguishable, but were isolated from four different states in Nigeria (Ogun, n = 9; Kaduna, n = 6; Plateau, n = 3, and: Bauchi, n = 2). PFGE revealed 40 pulsotype patterns (Kentucky, n = 12; Larochelle, n = 9; Virchow, n = 5; Saintpaul, n = 4; Poona, n = 3; Isangi, n = 2, and; Nigeria, n = 2). CONCLUSION: This study recorded strictly related but diversely distributed Salmonella serovars with high AMR rates in poultry. We recommend strict regulation on antimicrobial use and regular monitoring of AMR trends among bacteria isolated from animals and humans to inform public policy.

Characterization of intestinal microbiota in normal weight and overweight Border Collie and Labrador Retriever dogs.

Obesity in dogs is an emerging issue that affects canine health and well-being. Its development is ascribed to several factors, including genetic predisposition and dietary management, and recent evidence suggests that intestinal microbiota may be involved as well. Previous works have shown obesity to be linked to significant changes in gut microbiota composition in humans and mice, but only limited information is available on the role played by canine gut microbiota. The aim of this exploratory study was to investigate whether composition of canine faecal microbiota may be influenced by overweight condition and breed. All the enrolled companion dogs were young adults, intact, healthy, and fed commercial extruded pet food; none had received antibiotics, probiotics or immunosuppressant drugs in the previous six months. Labrador Retriever (LR) and Border Collie (BC) were chosen as reference breeds and Body Condition Score (BCS) on a 9-point scale as reference method for evaluating body fat. The faecal microbial communities of 15 lean (BCS 4-5/9; 7 LRs and 8 BCs) and 14 overweight (BCS > 5/9; 8 LRs and 6 BCs) family dogs were analysed using 16S rRNA gene sequencing. Moreover, for each dog, the daily intake of energy (kcal/d) and dietary macronutrients (g/d) were calculated according to an accurate feeding history collection. Firmicutes and Bacteroidetes resulted the predominant phyla (51.5 ± 10.0% and 33.4 ± 8.5%, respectively) in all dogs. Bioinformatic and statistical analysis revealed that no bacterial taxon differed significantly based on body condition, except for genus Allisonella (p < 0.05); BC gut microbiota was richer (p < 0.05) in bacteria belonging to phyla Actinobacteria (family Coriobacteriaceae in particular) and Firmicutes (Allobaculum and Roseburia genera). No remarkable differences were recorded either for diversity indices (i.e., alpha diversity, p > 0.10) or for divergence within the sample set (i.e., beta diversity, p > 0.05). PERMANOVA tests performed on single factors demonstrated the tendency of dietary protein to influence the recruited dogs' microbiota beta-diversity at amplicon sequence variant level (p = 0.08). In conclusion, the faecal microbiota of dogs involved in this exploratory study showed no major variations based on body condition. However, our findings suggested that certain bacterial taxa previously acknowledged in obesity-related studies may be detected in dissimilar amounts depending on canine breed.

Investigation of levels of perfluoroalkyl substances in freshwater fishes collected in a contaminated area of Veneto Region, Italy.

The bioaccumulation of 12 perfluoroalkyl substances (PFASs) in 107 freshwater fishes collected during 2017 in waterbodies of a contaminated area in Veneto Region (Italy) was evaluated. The contamination had been previously ascribed to a fluorochemical manufacturing plant that discharged mainly perfluorooctanoic acid (PFOA), among other PFASs, into the surrounding environment. Perfluorooctane sulfonate (PFOS) was the most abundant compound, detected in almost 99% of the fish with an average concentration of 9.23 µg/kg wet weight (w/w). Other detected compounds were perfluoroundecanoic acid (PFUnA) (98%, 0.55 µg/kg w/w), perfluorodecanoic acid (PFDA) (98%, 2.87 µg/kg w/w), perfluorododecanoic acid (PFDoA) (93%, 1.51 µg/kg w/w), and PFOA (79%, 0.33 µg/kg w/w). Bioaccumulation of PFASs was species related, with Italian barbel being the most contaminated, followed by chub, wels catfish, and carp, reflecting animals' habitat use and feeding behavior. A significant negative linear relation between PFAS concentration and fish weight was observed no matter the considered species, with smaller fish having proportionally higher bioaccumulation. PFOS concentrations were strongly correlated with the concentrations of other PFASs, suggesting a similar source of contamination or a contamination from ubiquitous sources. Correlation analysis showed PFOA likely originated from a separated source, unlinked to other PFASs. Although the fishes studied are not usually consumed by local people, with the likely exception of freshwater anglers (and relatives), their consumption has been banned by Veneto Authority since the time this study was conducted. In fact, the study suggests that a medium/high consumption frequency (superior to 1 portion per month) of fish from the investigated area might result in a high exposure to PFASs.

A rapid and sensitive method to identify and differentiate Salmonella enterica serotype Typhimurium and Salmonella enterica serotype 4,[5],12:i:- by combining traditional serotyping and multiplex polymerase chain reaction.

Salmonella enterica subspecies enterica serotype 4,[5],12:i:- is an emerging serovar considered as a monophasic variant of Salmonella enterica serotype Typhimurium. The antigenic and genetic similarity between Salmonella 4,[5],12:i:- and Salmonella Typhimurium suggests that they may behave in a similar way and represent a comparable threat to public health. As serotyping alone does not necessarily provide for identification of Salmonella 4,[5],12:i:- and its differentiation from Salmonella Typhimurium, a method that combines traditional serotyping and a multiplex polymerase chain reaction has been tested on 208 strains serotyped as Salmonella 4,[5],12:i:-, Salmonella Typhimurium, and similar serovars of serogroup B sharing the same phase-1 antigen "i." For 191 strains, the combined method fully confirmed the results provided by traditional serotyping, whereas for 17 strains of Salmonella 4,[5],12:i:- and Salmonella Typhimurium some inconsistencies emerged between the two methods. The combined method resulted in a more accurate and faster identification of these two relevant serovars.