Pathogenic parasites in ready-to-eat salads and berries sold on the Italian market

Among fresh produce, in recent years, the consumption of ready-to-eat (RTE) salads and berries has significantly increased in industrialized countries due to a trend towards faster and healthier eating habits. These products can be contaminated along the production food chain by several microorganisms, including pathogenic parasites that have been responsible of foodborne outbreaks worldwide. In Italy, while data on contamination of RTE salads require more-in-depth investigations there is a complete lack of data on berries, mostly imported from countries where some of these parasitic infections are endemic. The aim of this Ph.D. project was to investigate the occurrence of foodborne parasites as contaminants of imported and locally produced fresh produce sold on the Italian market. From January to December 2019, 648 packages of three brands of RTE mixed salads and three berry-types were bought from supermarkets. To estimate the prevalence, for each fresh produce, a pool size of nine packages each month and 72 pools per one year were processed. After washing, the pellets were examined by microscopy (FLOTAC) and subjected to different molecular techniques (conventional PCR, simplex or multiplex qPCR) and sequencing. By microscopy, Cyclospora-like oocysts and a taeniid egg were detected in a blueberry sample and in a RTE salad sample, respectively; Entamoeba and Giardia were also identified. Cyclospora cayetanensis and Entamoeba histolytica in imported blueberries and the Taeniid (Echinococcus multilocularis) in locally produced RTE salads were molecularly confirmed. Cryptosporidium ryanae, Cryptosporidium bovis, Cryptosporidium xiaoi and Cryptosporidium ubiquitum and Giardia duodenalis Assemblages A, B and E, most of them of zoonotic interest, were identified in both matrices. The overall prevalence of each parasite was 5.81% for Cryptosporidium spp., 4.63% for G. duodenalis, 0.15% for C. cayetanensis, 0.15% for E. multilocularis. Entamoeba spp. was also detected with a prevalence of 0.96%. Toxoplasma gondii was not found. Cryptosporidium spp. and G. duodenalis showed significant seasonal differences with higher values in winter and spring, respectively. In this study, most of the parasite species were detected for the first time on fresh produce. The results obtained, beside opening a new epidemiological scenario in Italy, highlight the improper management of fresh produce, both locally produced or imported, along the food chain and the potential consequences of such contamination on human health

Comparative evaluation of UNEX-based DNA extraction for molecular detection of Cyclospora cayetanensis, Toxoplasma gondii, and Cryptosporidium parvum as contaminants of berries

Abstract The potential public health impact of foodborne parasites transmitted via contaminated fresh produces indicates the necessity for robust and reliable laboratory methods for their detection and identification on this infection vehicle. Standardization of methods for detection of common FBP in fresh produce is to be expected and ensuring that the DNA extraction approach is most appropriate for the FBP of interest and for the matrix being analyzed is also important. Therefore, the aim of the present study was to compare the efficacy of two commercially available DNA extraction procedures, the UNEX-based method and DNeasy PowerSoil kit in the detection of three protozoan parasites, C. cayetanensis, C. parvum, and T. gondii, on contaminated berries. Oocysts of each parasite were spiked into the pellets of raspberry and blueberry washes. The spiked pellets were then randomly assigned to DNA extraction using either the PowerSoil or UNEX method, with DNA extraction with both methods performed by two independent analysts. The detection rate when berry washes were spiked with 20 oocysts of C. cayetanensis, T. gondii, and C. parvum was 95%, 85%, and 40%, respectively, when using the PowerSoil kit; whereas the equivalent results using the UNEX method were 55%, 60%, and 5%, respectively. In addition, significantly lower Cq values were achieved for each parasite in the samples spiked with 500 oocysts when the PowerSoil kit was used. Possible reasons for these results are discussed, and include the composition of both the beads and the buffers in each method

Global Emergence of Colistin-Resistant Escherichia coli in Food Chains and Associated Food Safety Implications: A Review

Antimicrobial resistance in bacteria represents one of the most important challenges for public health worldwide. Human infections from antimicrobial-resistant bacteria can be transmitted from person to person, via the environment (especially in the hospital environment), or via handling or eating contaminated foods. Colistin is well known as a last-resort antibiotic for the treatment of human infections; a recent study performed in the People's Republic of China has revealed that colistin resistance is also conferred by the plasmid-mediated mcr-1 gene in Escherichia coli. After that discovery, further plasmid-mediated, colistin resistance genes have been detected. However, to date, only reports on E. coli carrying the mcr-1 gene (E. coli mcr-1+) in foodstuff are available. E. coli mcr-1+ has been isolated from food of animal origin and vegetables; this discovery has opened a debate among food safety experts. This review aims to provide a critical overview of the currently available scientific literature on the presence of the plasmid-mediated, colistin resistance gene E. coli mcr-1 in foodstuffs, focusing on the main implications and future perspectives for food safety

Dermanyssus gallinae in non-avian hosts: A case report in a dog and review of the literature

Non-avian attacks of the worldwide distributed mite Dermanyssus gallinae are occasionally reported. However, it is widely accepted that their occurrence is underestimated. The present study aims to describe the first Italian case of dermanyssosis in a dog, to molecularly characterize the mites collected from the patient and the animal enclosure, where poultry and dog were confined, and to review the current literature on the non-avian attacks by D. gallinae. The dog was successfully treated with an oral sarolaner-based product, followed by a spot-on formulation of imidacloprid and moxidectin. The infestation source was likely attributable to poultry and confirmed by molecular identification of D. gallinae sensu strictu. Ten articles on non-avian D. gallinae attacks in domestic animals and wildlife were retrieved, pointing out the need for more awareness amongst practitioners. The therapeutic effect of available antiparasitic drugs, currently used off-label, should also be better explored in non-avian hosts

Final destination: The Mediterranean Sea, a vulnerable sea. The long journey of Giardia duodenalis cysts.

The Mediterranean Sea is considered a “litmus paper” of pollution risks for any parameter, including faecal contamination. Giardia duodenalis is one of the most important protozoan parasites responsible for diarrhoea in a wide range of hosts, including humans, domestic and wild animals, worldwide. The degree of contamination related to the protozoan’s resistant forms on land, and the consequent transport through rivers from point sources to the sea are important aspects to better understand the processes involved in the microbiological pollution of aquatic ecosystems. However, land-sea transfer routes and the complex transmission patterns often remain neglected. This contribution deals with the contamination by G. duodenalis of the Mediterranean Sea through its inhabitants (shellfish, marine mammals, fishes), and provides data on the origin of such contamination on land from humans and animals to soil, fresh produce and waters; this scenario allows to understand the long journey of the protozoan following the drainage basins (i.e., natural watersheds) from the mainland towards the final destination. The Mediterranean Sea contamination is also explained in the light of the Giardia survival in water and the effects of climatic change with the related consequences. Addressing faecal contamination threats in the Mediterranean Sea is a difficult task, but a number of mitigation measures need to be implemented and/or in some countries even applied. Effective management must become a priority in the agenda of policy makers of all Mediterranean Countries for the implementation of successful measures and can only be applied in the perspective of the One Health approach

Dermanysuss gallinae attacks humans. Mind the gap

ABSTRACTDermanyssus gallinae is a haematophagous ectoparasite primarily known as a pest of domestic and wild birds. It occasionally feeds on a range of mammals, and, more importantly, is of growing..

A Comparison of Copromicroscopic and Molecular Methods for the Diagnosis of Cat Aelurostrongylosis

The gold standard method for the diagnosis of cat aelurostrongylosis is the detection of Aelurostrongylus abstrusus first stage larvae with the Baermann's examination. Nevertheless, molecular assays have shown higher diagnostic performances compared to copromicroscopy. This study evaluated the usefulness of an A. abstrusus species-specific PCR on different biological samples collected in clinical settings from 100 privately-owned cats in Italy (n. 60) and Greece (n. 40). A fecal sample was collected from each animal and a pharyngeal swab was also obtained for cats from Italy. All stool samples were subjected to flotation and Baermann's test. The cats were categorized in three groups based on the results of copromicroscopy, i.e., Group A (n. 50 cats with A. abstrusus infection regardless of positivity for other helminths), Group B (n. 25 cats negative for A. abstrusus but positive for at least one of any other helminth), Group C (n. 25 cats negative for any helminth). DNA was extracted from individual aliquots of feces, flotation supernatant, Baermann's sediment and the pharyngeal swab and then subjected to a PCR specific for A. abstrusus. At least one fecal aliquot or the pharyngeal swab scored positive by the A. abstrusus-specific PCR for 48/50 (96%) cats enrolled in Group A; in particular, 38/50 (76%), 35/50 (70%), 41/50 (82%) and 21/25 (84%) DNA extracts from feces, flotation supernatant, Baermann's sediment and pharyngeal swabs were positive by PCR. These results confirm that molecular tools are highly sensitive and specific and indicate that pharyngeal swabs are the most suitable sample for molecular analysis in clinical settings

Habronematidosis in Equids: Current Status, Advances, Future Challenges

Over the past few decades, among equine parasitoses caused by gastrointestinal nematodes, habronematidosis has been discontinuously studied worldwide. Habronematidosis is a parasitic disease distributed all over the world. It is caused by Habronema microstoma, Habronema muscae, and Draschia megastoma (Spirurida, Habronematidae), and it is maintained in the environment by muscid flies which act as intermediate hosts. At larval and adult stages these species live in the stomach of domestic and wild equids. However, the larvae can also be found on the skin, causing lesions known as “summer sores”, and occasionally on other body areas, such as ocular and genital mucosa (muco-cutaneous habronematidosis) and lung, liver, brain parenchyma. Depending on the parasite's developmental stage and localization site, clinical signs vary from mild to severe. Habronematidosis is responsible for significant economic losses, mostly when sport horses are affected, because their performances are impaired and the infection can be unaesthetic. We used three on-line databases for searching the articles on habronematidosis according to the selected inclusion criteria; a total of 250 contributions, published between 1911 and 2020 were analyzed. This review summarizes the key features of pathogenesis, epizootiology, diagnosis, treatment, and control of habronematidosis, and highlights the current knownledge about its geographical distribution and spread. Anthelmintic drugs are the most widely-used tools against habronematidosis; given the known risk of anthelmintic resistance in some nematodes affecting horses, this aspect should also be explored for habronematidosis. Dedicated research is essential to fill gaps of knowledge and increase the understanding of habronematidosis to maximize equine health, reduce economic losses and sanitary impact associated with this parasitic infection

Methicillin-Resistant Staphylococcus aureus (MRSA) in Food of Animal Origin: A New Challenge in Food Safety?

Background: Methicillin-resistant Staphylococcus aureus (MRSA) causes a wide range of infections, sometimes fatal, and represents a major problem in both human and veterinary medicine. The global spread of intensive farming and the high and indiscriminate use of antimicrobials has favoured the selection and circulation of MRSA in livestock and, consequently, in food of animal origin. The presence of MRSA is well documented in foodstuff, such as, beef, pork, poultry and rabbit meat as well as fish, raw milk and table eggs. The strains mostly isolated from food are animal associated, i.e. CC398; however, human strains have also been isolated from foodstuff. Some of these MRSA strains are capable of synthesizing staphylococcal enterotoxins. : In this review, the origin and the significance of MRSA in food of animal origin are discussed from a food safety point of vie