Immunohistochemical investigations on Brucella ceti-infected, neurobrucellosis-affected striped dolphins (Stenella coeruleoalba)

Bacteria of the genus Brucella cause brucellosis, an infectious disease common to humans as well as to terrestrial and aquatic mammals. Since 1994 several cases of Brucella spp. infection have been reported in marine mammals worldwide. While sero-epidemiological data suggest that Brucella spp. infection is widespread globally, detecting Brucella spp.-associated antigens by immunohistochemistry (IHC) in tissues from infected animals is often troublesome. The present study was aimed at investigating, by means of IHC based upon the utilization of an anti-Brucella LPS monoclonal antibody (MAb), the central nervous system (CNS) immunoreactivity shown by B. ceti-infected, neurobrucellosis-affected striped dolphins. The aforementioned MAb, previously characterized by means of ELISA and Western Blotting techniques, was able to immunohistochemically detect smooth brucellae both within the CNS from B. ceti-infected striped dolphins and within a range of tissues from Brucella spp.-infected domestic ruminants. In conclusion, the results of the present study are of relevance both from the B. ceti infection's diagnostic and pathogenetic standpoints.

Evaluation of veterinary autogenous vaccines safety by an MTT in-vitro cytotoxicity assay

In Italy, veterinary autogenous vaccines manufacturing is regulated by the legislative decree of the Ministry of Health, March 17th, 1994, n. 287. The production is performed by the network of the 'Istituti Zooprofilattici Sperimentali' (IZSs), public health institutes scattered all over the Italian territory. The aim of this research was to evaluate the feasibility of an in vitro method to test the abnormal toxicity of autogenous bacterial vaccines as an alternative to animal models routinely employed. For this purpose, the Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise (IZSAM) in partnership with the Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna (IZSLER), evaluated the toxicity of 49 batches of autogenous bacterial vaccines, previously shown to be safe in guinea pigs and mice, on animal model, by means of the methyl tetrazolium (MTT) assay. All vaccines showed cytotoxic effects when tested 1:2 diluted and undiluted; overall, all vaccines lost toxicity at 1:128 dilution. As expected, these findings suggest a different susceptibility of this assay  compared to the laboratory animal model. On the other hand, these results do not clarify which components of the vaccines are responsible for the cytotoxic effect. Overall, more experiments are warranted in order to standardize the MTT assay which could be coupled with the trials in laboratory animals.

Assessment of hygienic quality of some types of cheese sampled from retail outlets

The authors evaluated the prevalence of Listeria monocytogenes, Escherichia coli O157:H7, Salmonella spp. and staphylococcal enterotoxin, in 2,132 samples selected from six types of cheese on the basis of recorded consumption in Italy in 2004. In L. monocytogenes-positive samples the precise level of contamination was determined. To define the physical-chemical characteristics of the selected natural cheeses, the pH values, water activity and sodium chloride content were determined. The results suggest that blue and soft cheeses (Brie, Camembert, Gorgonzola and Taleggio) are more likely to be contaminated with L. monocytogenes. The mean prevalence of L. monocytogenes in the six types of cheese was 2.4% (from 0.2% in Asiago and Crescenza to 6.5% in Taleggio), with contamination levels of up to 460 MPN/g. No presence of Salmonella spp. and E. coli O157 was found in any sample. Staphylococcus enterotoxin was found in 0.6% of the samples examined. Physical and chemical parameter values confirmed that all types of cheese are considered capable of supporting the growth of L. monocytogenes. The study confirmed the need to apply effective control at production and sales levels to reduce the probability of contamination by L. monocytogenes. This micro-organism can attain high levels of contamination in food products, such as cheeses that have a long shelf-life when associated with difficulties of maintaining appropriate storage temperatures in both sales points and in the home.

Polymerase chain reaction and bacteriological comparative analysis of raw milk samples and buffalo mozzarella produced and marketed in Caserta in the Campania region of Italy

To help identify an epidemiological link between the consumption of buffalo mozzarella prepared with raw milk (not heat-treated) and cases of human brucellosis, 80 samples of raw buffalo milk and 315 samples of mozzarella were tested for the presence of Brucella spp. Samples originated from Caserta, the province with the highest number of Brucella-positive buffalo herds in Campania, the region in which 96.02% of all cases of human brucellosis reported in 2000-2005 were recorded. To take into account possible seasonal variations, between February 2006 and March 2007, samples were purchased directly from 72 dairy outlets that were representative of the province. Samples were tested for Brucella spp. using the polymerase chain reaction (PCR) and bacterial isolation. Samples tested negative for Brucella using both methods. Spiked samples were then prepared and tested by PCR and bacterial isolation and the sensitivity, specificity, repeatability, reproducibility and limit of detection were determined. The PCR limit of detection was below 1 colony-forming unit (cfu)/g. The repeatability and reproducibility of the method were 100% (p = 0.95), the sensitivity was 96.7% (p = 0.95) and the specificity was 100% (p = 0.95).

Two cases of methemoglobinaemia caused by suspected sodium nitrite poisoning

Among the causes of acute methemoglobinaemia are the ingestion and inhalation of over 40 oxidising substances, including nitrite, nitrate, carbon monoxide, some medicines, chlorine. The authors describe a case of acute methemoglobinaemia in two people that most probably suffered from food poisoning resulting from the consumption of a preparation of a dish called turkey alla canzanese that contained significant amounts of sodium nitrite. Both subjects who were treated promptly with methylene blue and hyperbaric oxygen therapy room recovered fully. Epidemiological investigations performed to clarify the dynamics of the episode suggested that among the causes of contamination were the swapping of products at the time of sale and the non-compliance to rules for the preparation of foods for human consumption.

Surveillance system and rapid tracing of primary sources in food-borne outbreaks by Salmonella spp. Part II: Molecular characterisation of some strains of Salmonella enterica serovars Enteritidis and Typhimurium

Salmonella enterica serovars Enteritidis and Typhimurium are the serotypes most frequently isolated from human cases. Traditional surveillance systems, based on serological characterisation and epidemiology, are not able to identify these common strains that cause outbreaks in humans. Innovative techniques are therefore necessary to accurately characterise these serotypes and hence accelerate the identification of the primary sources. Within a larger study, the goal of which was to develop an active surveillance system for outbreaks of food-borne diseases, characterisation of 42 Salmonella strains was performed using molecular techniques (pulsed field gel electrophoresis [PFGE] and random amplified polymorphic DNA [RAPD]), together with the Kirby-Bauer antibiotic assay. Results showed that both techniques were unable to satisfactorily characterise the Enteritidis serotype, while only PFGE identified the Typhimurium serotype.

Surveillance system and rapid tracing of primary sources in foodborne outbreaks by Salmonella spp. Part I: Identification of outbreaks in the Abruzzo region of Italy

The determination of the origin of foodborne diseases is one of the top priorities for the world health community. Gastroenteritis caused by zoonotic Salmonella serovars is one of the major threats to human health. It is essential that surveillance systems are able to monitor the incidence of human cases and to provide useful data to plan and implement effective prevention strategies. Surveillance systems generate information that is of value both for the early detection of infection and for the identification of epidemiological trends and risk factors. The authors describe a surveillance system for the identification of the sources of infection foodborne disease outbreaks caused by Salmonella in the Abruzzo region of Italy between April 2000 and October 2002.

Hygienic quality and freshness of shell eggs collected at retail outlets in Italy

Shell eggs sampled at retail outlets in two large Italian cities were tested to assess their freshness, food safety and the presence of veterinary drug residues. Some samples were found to be irregular due to lack of compliance with freshness requirements or shells were tainted by micro-cracks and foreign material. The most severe case of non-compliance was due to the presence of veterinary drug residues that either exceeded either the maximum acceptable residue limits or drugs that were prohibited.