Guido Maria Grasso

Vibrio spp. infections still are a Public Health concern. Vibrio spp. can be found in marine, estuarine, and freshwater environments, and can be able to cause diseases in fish, shellfish, mammals, as well as in humans. Since '80 to date, the number of species within the genus increased from 21 to more than 100. The most important is Vibrio cholerae, the etiological agent of the cholera, responsible of seven pandemics; serotypes O1 and O139 can produce cholera toxin, while serotypes non-O1/non-O139 are generally associated with sporadic cholera cases and extraintestinal infections. Vibrio parahaemolyticus is an important cause of gastroenteritis associated with contaminated seafood consumption, whereas Vibrio vulnificus and V. alginolyticus can be related to wound infections or seafoodborne primary septicemia in immunocompromised patients. Disease prevention is mainly based on the application of proper individual or collective preventive measures.

Aims: In this study, 105 Listeria monocytogenes strains isolated from humans, foods and environmental samples were characterized using several typing methods. Moreover, serotyping procedure was evaluated, and a cost-effective methodological approach based on preliminary PCRs screening was proposed. Methods and Results: The isolates were analysed by conventional serotyping, multiplex-PCRs for serogroup and lineage identification and PCR–RFLP of inlA gene to identify potentially noninvasive L. monocytogenes. Among the strains, only the serotypes 1/2a, 1/2c, 1/2b, 4b and 3a were identified. The isolates were classified into serogroups I (58·10%), II (22·85%), III (12·38%) and IV (6·67%). Among clinical strains, lineage I was more represented (68·75%) than lineage II; whereas, lineage II was more associated with food (90·24%) and environmental (85·72%) isolates. Most of food (89·02%) and environmental (85·71%) isolates were classified into truncated InlA profiles, whereas the 93·75% of clinical strains were associated with a complete form of the protein. Conclusion: Molecular techniques were sensitive and specific for classifying strains into serogroup and lineage and in agreement with the serotyping. Moreover, a preliminary PCRs-based screening was proposed to select only the necessary antisera by a flow chart; this methodological approach allows cost saving up to 42%. Our results further suggest the role of InlA protein in human listeriosis, particularly in immunocompetent individuals, and a correlation between truncated protein and serotype. Significance and Impact of the Study: This study further validates molecular methods for L. monocytogenes analysis and proposed a new cost-effective approach for serotyping. It could help to improve a national surveillance network for L. monocytogenes infections in Italy.

We estimated the prevalence of Campylobacter spp. in retail meat (n = 352 samples; 104 chicken, 106 pork, and 142 beef) collected in Campobasso, Italy, comparing two microbiological methods. All the isolates were characterized by biomolecular techniques for epidemiological purposes. Campylobacter isolation was performed by selective culture and membrane filtration methods. Phenotypic and genotypic methods for genus and species identification were evaluated together with antimicrobial resistance and plasmid profiling. Sixty-nine (86.2%) samples were positive by selective culture, 49 (61.2%) by membrane filtration, and 38 (47.5%) by both methods. Only 74 of 80 strains were confirmed as Campylobacter spp. by PCR, and two Campylobacter coli were identified as Campylobacter jejuni . Chicken meat was more frequently contaminated than other meats. Selective culture was more sensitive than membrane filtration (85 versus 66%), and specificity of the methods was 98 and 100%, respectively. Among Campylobacter isolates from chicken meat, 86.5% were multidrug resistant. Resistance to ciprofloxacin (51.3%) and enrofloxacin (52.7%) was lower than to nalidixic acid (71.6%). C. coli strains showed the highest cross-resistance for quinolones (82.6%) and fluoroquinolones (60.9%) as well as a high resistance to tetracycline. Plasmids were isolated from six C. coli and two C. jejuni isolates, but no association was detected between antimicrobial resistance and plasmid DNA carriage. Selective culture is considered as the optimal method for Campylobacter isolation, although it was unable to detect all contaminated samples. Membrane filtration provided more specific results but with low sensitivity. A combination of both techniques may offer better results.

In this study, we compared and validated a nested ABC polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay to amplify Cryptosporidium parvum oocyst wall protein (COWP) gene fragment with a previous nested PCR-RFLP method. When RFLP of COWP gene did not provide clear results, we further analysed samples by cloning and sequencing for species and genotype identification. ABC-PCR was performed on DNA extracted from human faecal samples collected in England where Cryptosporidium was previously detected by conventional methods. COWP gene amplification was successful for all specimens; RFLP analyses using both RsaI and AluI enzymes recognised 54/55 restriction profiles. Among these, 40 (72.7%) characteristic patterns were generated for C. parvum and six (10.9%) for Cryptosporidium hominis; four (7.3%) showed species mixtures, while the remaining four samples (7.3%) showed atypical genotypes. Cloning and sequencing of mixtures and atypical genotypes identified one C. parvum, one C. hominis and three Cryptosporidium meleagridis. Indeed, molecular tools improved PCR-RFLP results. In conclusion, this study showed that ABC-PCR-RFLP technique was quick, simple and specific. Cloning and sequencing were helpful in characterising mixtures or previously uncharacterised RFLP patterns. All these epidemiological findings are useful information for any preventive intervention to control disease diffusion.

Aquaculture is becoming increasingly diffuse even in Italy. The increased production introduces new problems such as product quality control and process safety. This article presents the results of a research project, funded by the Ministry of the Environment, whose aim was to evaluate and promote aquaculture product quality and safety in an environmentally responsible way. Four intensive land-based and offshore aquaculture sites were monitored to evaluate microbiological, biological and chemical (i.e. polychlorinated biphenyls and endocrine disruptors) quality of water, products and fish feed. In total 154 samples were analysed, of which 66 were water samples, 55 product samples and 33 feed samples. Salmonella and other enteric pathogens were absent in products and the aquatic environment, while other environmental pathogens of the Vibrio species were detected. Bacterial load and fecal indicators were found to be higher in off-shore products and in mussels from all aquaculture sites. PCBs were detected in all products in concentrations below 2 microg/g fresh product (Food and Drug Administration), but on average, higher concentrations were detected in off-shore products. No estrogen mimetic activity was detected in fish feed, in contrast it was detected in offshore products and water. Product quality was found to be strictly correlated with the quality of the environment. Genetically modified organisms were detected in fish feed but no integration of genetic material in products occurred.

Alcohol consumption during pregnancy is a significant public health problem and is an established cause of serious birth defects and developmental delay collectively described as fetal alcohol syndrome (FAS). FAS is caused by congenital alcohol-induced damages and is a cause of mental retardation. It is characterised by facial abnormalities and growth deficiency. Infants affected by the syndrome show intellectual impairment, and difficulties in learning, memory, problem-solving, and attention as well as experiencing additional problems with mental health and social interactions. However, an absence of the characteristic facial defects and growth deficiency may result in a failure to identify children with prenatal alcohol exposure, which can further present as alcohol-related neurodevelopment disorder (ARND) or alcohol-related birth defects (ARBD). Estimates of prevalence of FAS in U.S.A. range between 0.3 to 2.2 per 1,000 live births, but much higher rates occurring in some communities. Harmonisation of the methodology used for epidemiological studies, with research activities that establishes real baseline prevalence of FAS and identification of women who are at highest risk of bearing a FAS-affected child, are an essential prerequisite to prevention. In addition, it is essential to assess different FAS preventive approaches through carefully controlled studies. Universal, selected, and indicated preventive strategies have been identified, targeting different kind of populations. Since FAS and other adverse effects of drinking during pregnancy are theoretically completely preventable, it is vital to make more efforts to improve the application of the most appropriate interventions. Although in Italy alcohol consumption has constantly increased, mainly amongst the young (including women of childbearing age), knowledge on FAS and alcohol-related effects is completely lacking. Because of the high cost for care of individuals with this syndrome, it is essential to apply appropriate interventions to prevent this problem.

The study was performed to estimate the prevalence and antimicrobial sensitivities of Listeria spp. in raw milk, feaces end environmental samples isolated from 10 dairy in Molise Region. A total of 454 samples were collected, which comprised 40 raw milk, 40 animal faeces and 374 environmental samples. Listeria monocytogenes was never isolated from raw milk specimens; one was isolated from faeces speciments and two were isolated from environmental samples. All isolates were resistant to two or more of antimicrobial agents tested (cephalotin, ampicillin, tetracycline, co-trimoxazole, erytromicin, clindamycin, gentamicin, oxacillin). One isolate of L. monocytogenes was susceptible to all antimicrobial agents tested except oxacillin. This study indicates that faeces, equipments and environment are important reservoirs of Listeria spp. in dairy farm, and can represent potential source of contamination of raw milk. However, the contamination of milk, and the risk of infection, can be effectively eliminated by pasteurisation process.

Recovery of Cryptosporidium parvum oocysts in a fecal suspension that experimentally contaminated onto lettuce leaves was investigated. Material recovered from the lettuce samples by washing in detergent solutions were concentrated by filtration using the Envirochek Sampling Capsule. Oocysts were concentrated by immunomagnetic separation (IMS) and detected by microscopy following modified Ziehl-Neelsen (MZN) staining. Cryptosporidal DNA was detected using a nested-PCR assay for amplification of a fragment of the Cryptosporidium oocyst wall protein (COWP) gene, which was applied to DNA extracted from both filtrates, and material recovered from MZN stained smears on glass slides after microscopy. No Cryptosporidium were detected by microscopy or by PCR of un-inoculated lettuce leaves. After IMS, means of 0-6.5% of the total numbers of oocysts inoculated were recovered and detected by microscopy. Detection by PCR was less sensitive than microscopy. There was a strong association between successful PCR amplification, the numbers of oocysts detected by microscopy and the numbers of oocysts in the inoculum. This study confirms that C. parvum oocysts can be recovered from contaminated lettuce using filtration and IMS, and detected by microscopy and PCR. However, further developments are required to improve recovery of this parasite.