Contamination of Bovine, Sheep and Goat Meat with Brucella Spp.

A study was conducted in order to evaluate the contamination by Brucella spp. of meat from animals slaughtered because they had resulted positive for brucellosis at some time during their life. After slaughter and before delivery to market outlets, swab samples were taken from 307 carcasses of infected animals: 40 cattle, 60 sheep and 207 goats. The swabs were subsequently analysed by means of polymerase chain reaction (PCR) tests. In addition, bacteriological tests were carried out on the lymph nodes and internal organs of the same animals. Brucella spp. was detected by means of PCR in 25/307 carcasses (8%): 1 bovine (2.5%), 9 sheep (15%) and 15 goats (7.2%) and was isolated by means of a cultural method in 136/307 carcasses (44%). Moreover, additional analysis, performed on lymph nodes from the same carcasses that had proved positive by PCR, allowed highlighting type 3 Brucella abortus in the bovine carcass and type 3 Brucella melitensis in the sheep and goat carcasses. The study shows that cattle, sheep and goats meat of animals slaughtered because they had tested positive for brucellosis may be contaminated by Brucella spp. As this could constitute a real risk of transmission to both butchery personnel and consumers, the meat of animals infected by Brucella spp. should be analysed before being marketed. In this respect, PCR technique performed on swabs proved to be more useful, practical and faster than the traditional bacteriological method.

Microbiological Stability of Canned Tuna Produced in Italy and in Non-European Countries.

The results of a study on the microbiological stability of canned tuna produced by Italian companies and similar canned products manufactured in countries outside Europe are reported herein. The study involved 38 samples of canned tuna of various brands, of which 14 were produced by companies outside Europe and 24 by Italian companies. Qualitative and quantitative microbiological tests were conducted for the following parameters: bacterial colony counts at 30°C, total coliforms, total Enterobacteriaceae, sulphite-reducing anaerobes, Salmonella spp., Bacillus cereus, Escherichia coli, Staphylococcus aureus, yeasts and molds. Bacterial loads and mold contamination were respectivelyin found in 8/14 (57%) samples from outside EU and 7/24 (29%) Italian samples. The bacterial flora was represented by Gram-positive bacteria (Staphylococcus warneri, Staphylococcus lentus, Streptococcus mitis, Enterococcus faecalis, Leuconostoc mesenteroides), Gram-negative bacteria (Sphingomonas paucimobilis, Acinetobacter iwoffii, Rhizobium radiobacter), spore-forming bacteria (Bacillus vallismortis), while the fungal species was represented by Penicillium spp., Rhizopus spp., Rhodotorula spp. and Alternaria spp. Excluding anomalies in the thermal treatment process of products and any contamination after treatment, the contaminations encountered in both cases were most likely due to insufficient production quality standards and the quality of the raw material used. These results may require a redefinition of the concept of commercial stability as hitherto stated.

Isolation of Cronobacter spp. (Enterobacter Sakazakii) from Artisanal Mozzarella.

Cronobacter spp. (Enterobacter sakazakii) is an opportunistic bacterial pathogen capable of causing disease and even fatalities in newborn infants within the first weeks of life if consumed as part of the diet. Premature and immunocompromised newborn infants are at particular risk. The microorganism has been isolated from a variety of foods including contaminated infant milk formula powder and milk powder substitute. The study aimed to evaluate the level of microbiological contamination in 47 samples of mozzarella cheese made with cow's milk collected from artisan cheese producers in Southern Italy. Samples were collected from commercial sales points and underwent qualitative and quantitative microbiological analyses to test for the bacterial contaminants most commonly found in milk and cheese products. The 47 samples underwent qualitative and quantitative microbiological tests according to ISO UNI EN standards. Analyses focused on Staphylococcus aures, Salmonella spp., Listeria monocytogenes, Pseudomonas spp., E. coli, Yersinia spp., total coliforms and Cronobacter sakazakii. The ISO/TS 22964:2006 method was used to investigate possible contamination by C. sakazakii. Biochemical identification was carried out using an automated system for identification and susceptibility tests. None of the samples examined resulted positive for Salmonella spp. or Listeria spp. Only one sample resulted positive for Staphylococcus aureus. Pseudomonas spp. was isolated in 10 (21%) of 47 samples. High levels of total coliforms were found in 10 of 47 samples. Cronobacter spp. (Enterobacter sakazakii) was isolated in one sample. This is the first study to confirm isolation of C. sakazakii in artisan mozzarella cheese made from cow's milk. The presence of C. sakazakii could be related to external contamination during the phases of production or to the use of contaminated milk. Since mozzarella is recommended in the diet of children and adults of all ages, this present study helps define it as a potential vehicle for C. sakazakii in subjects at particular risk.