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Environmental samples, raw materials and fermented sausages produced in sardinia (Italy) were analysed in order to investigate the prevalence and enumeration of L. monocytogenes. Isolates were identified by single PCR and characterised by multiplex PCR-based serogrouping. the contamination routes of L. monocytogenes in the plants were traced using PFGE. In addition, a quantitative assessment of the in vitro biofilm formation was carried out. Fermented sausages seem to be regularly contaminated with L. monocytogenes: results showed the ability of the pathogen to overcome the hurdles of the manufacturing process and adapt to the processing plant environments, forming biofilms. [ABSTRACT FROM AUTHOR]

Quantitative assessment of in vitro biofilm formation by 40 Salmonella enterica isolates isolated in pig abattoirs from animal and environmental sources (surfaces in contact and not in contact with meat) and classified in eight seroytpes was carried out by using a microtiter plate assay with spectrophotometric reading (optical density at 620 nm). Biofilm-forming ability was statistically correlated with the temperature of incubation (22 and 35°C), the source of the isolates, and the antimicrobial resistance profile. After incubation at 35°C, 9 isolates (22.5%) were classified as weak biofilm producers. After incubation at 22°C, 25 isolates (62.5%) were classified as weak producers and 3 (7.5%) as moderate producers. The quantity of biofilm formed after incubation at 22°C was significantly higher (P < 0.01) than at 35°C. This result is notable because 22°C is a common temperature in meat processing facilities and in slaughterhouses. At 35°C, isolates detected from surfaces in contact with meat showed significantly higher (P < 0.1) optical density values compared to isolates from other samples, highlighting the risk of cross-contamination for carcasses and offal. No correlation was detected between quantity of biofilm and serotype or between biofilm formation and resistance to antimicrobials.

Listeriosis is a foodborne disease caused by Listeria monocytogenes and is considered as a serious health problem, due to the severity of symptoms and the high mortality rate. Recently, other Listeria species have been associated with disease in human and animals. The aim of this study was to develop a multiplex polymerase chain reaction (PCR) in order to simultaneously detect six Listeria species (L. grayi , L. welshimeri , L. ivanovii , L. monocytogenes , L. seeligeri , L. innocua) in a single reaction. One hundred eighteen Listeria spp . strains, isolated from meat products (sausages) and processing plants (surfaces in contact and not in contact with meat), were included in the study. All the strains were submitted to biochemical identification using the API Listeria system. A multiplex PCR was developed with the aim to identify the six species of Listeria . PCR allowed to uniquely identify strains that had expressed a doubtful profile with API Listeria The results suggest that the multiplex PCR could represent a rapid and sensitive screening test, a reliable method for the detection of all Listeria species, both in contaminated food and in clinical samples, and also a tool that could be used for epidemiological purposes in food-borne outbreaks. A further application could be the development of a PCR that can be directly applied to the pre-enrichment broth., Competing Interests: the authors declare no potential conflict of interest.

Persistence of Listeria monocytogenes strains in food processing environments remains relatively common but is difficult to control. Understanding the basis for such persistence represents an important step in the potential control or eradication of this pathogen from these environments. In this study, reverse transcription PCR was used to determine the relative and absolute expression of selected gene targets (pocR, eutJ, and qacH) among five persistent and four presumed nonpersistent L. monocytogenes strains. The quantification of these genes as markers for the persistent phenotype and the effect of benzethonium chloride (BZT) on their expression was investigated. Although no markers correlated with the ability of strains to persist in food processing facilities were found, expression of pocR was upregulated in three of the five persistent strains, in contrast to the four presumed nonpersistent strains, which showed down-regulation of this gene. These results provide further knowledge of the differential expression of genes of persistent and presumed nonpersistent strains of L. monocytogenes grown in the presence or absence of BZT and identifies upregulation of pocR as a potential response of persistent strains of L. monocytogenes to exposure to BZT.

Mislabelling and species substitution are major concerns for fishery products marketed in the EU. The present survey aimed to investigate the correct enforcement of the Community and National rules on the labelling and marketing of fishery products retailed in Sardinia (Italy) between 2009 and 2014. A total of 3000 labels for fresh unpacked fishery products have been considered. A total of 900 labels (30%) presented non-compliance concerning the wrong trade name, the wrong or missing information about the catch area and the production method. The highest percentage of mislabelling and species substitution has been detected in open-air markets (65%) and small-scale retail shops (40%) compared with the big supermarket chains (10%). The high percentage of non-compliances with the European and Italian legislation highlights the need to improve the essential information demanded by consumers on fishery products marketed in open-air markets and small-scale retail shops. While there are laws in place, it is unclear how effective they are and what type of penalties food business operators of open-air markets and small-scale retail shops may incur.

The slaughtering procedures at agritourism farms must be carried out in accordance with the general and hygiene requirements of Regulations (EC) No 852 and 853/2004. In addition, regional laws define minimum requirements allowing some flexibility. Piglets and finishing pigs are the most frequently slaughtered animal in Sardinian agritourism farms. The aim of the present survey was to evaluate: the general and hygiene requirements of outbuilding slaughterhouses in agritourisms; the animal welfare indicators; the microbial contamination of piglets and finishing pigs carcasses. Six agritourisms outbuilding slaughterhouses - EU-approved - were investigated. General and hygiene requirements of outbuilding slaughterhouses and animal welfare indicators of 68 piglets and 5 finishing pigs were evaluated by mean of a checklist. The following parameters were determined on 45 piglets and 5 finishing pigs carcasses: i) pH 1 and 24 h after slaughter, and ii) carcass surface microbial contamination by non destructive method (sponge) on the following sampling sites: ham; back (adults); belly; jowl (adults). Aerobic colony count (ACC; ISO 4833:2003), Enterobacteriaceae (EB; ISO 21528-2:2004), Salmonella spp. (ISO 6579:2002), Listeria monocytogenes (ISO 11290-1:1996 and 11290-2:1998) were also tested. All the plants except one have two separate rooms, for clean and dirty zones, stunning and bleeding operations being frequently carried out on open air. The piglet scalding was carried out in hot water bowls, and hair removal by singeing. Animal welfare signs revealed the following aspects: handling: hoisting prior to stunning, vocalizations (41%); stunning: not individual access to box, repeated shocks (4%), mean voltage 135.6 V, mean current for head-only electrical stunning 0.78 A; indicators of not effective stunning: palpebral reflex (24.2%), corneal reflex (12.8%), vocalizations (15.4%); bleeding: conscious and sensitive animal shackling (53.8%). Results of carcass evaluation showed, for piglets and adult pig respectively: i) pH: pH1=6.21±0.25 and 6.18±0.22; pH24=5.66±0.17 and 5.49±0.11; ii) ACC: 4.11±0.64 and 4.63±0.42 (log10 CFU/cm2, mean±standard deviation); iii) Enterobacteriaceae prevalence of 81.6% (2.55±0.80) in piglets and 100% (3.22±0.90) in adults. Salmonella spp. and Listeria monocytogenes were not detected in any of the samples. General requirements of outbuilding slaughterhouses in agritourisms are suitable to produce meat in compliance with hygienic rules, considering the low risk level. Results of Enterobacteriaceae levels of finishing pig carcasses were not in compliance with the EC Regulation No 2073/2005. Training of personnel is compulsory and can improve the stunning and bleeding procedures., Competing Interests: the authors declare no potential conflict of interest.

Healthy pigs carrying pathogenic to human Yersinia enterocolitica strains are the main source of entry into slaughterhouse, where cross-contamination of carcasses can happen. The aim of this work was to determine Y. enterocolitica prevalence in slaughtered pigs, investigating the presence of carriers in relation to carcass contamination. A total of 132 pig samples (tonsils, mesenteric lymph nodes, colon content, carcass surface) were collected from 4 Sardinian slaughterhouses. All the samples were examined by the ISO 10273:2003 method, and the prevalence was also determined by direct plating on CIN Agar. Moreover, to detect the ail positive Y. enterocolitica strains in enrichment broths and isolates a real-time polymerase chain reaction (PCR) was applied. Y. enterocolitica prevalence was 19% with direct plating and 12% with enrichment methods. Carcass surfaces and tonsils prevalence was 5.30% by direct plating, and 5.3% and 2.2%, respectively, by enrichment method. Tonsil samples showed an average contamination level of 3.2×103 CFU/g, while the mean value on carcass was 8.7×102 CFU/g. An overall prevalence of 9.8% of ail positive Y. enterocolitica broths was detected by RT-PCR, that found a higher prevalence in tonsils (7.5%) with respect to cultural methods, confirming the greater sensitivity of this technique when applied for tonsils and faeces samples. The results show a relatively low pathogenic Y. enterocolitica prevalence in pigs slaughtered in Sardinia. Good hygiene measures should be applied at slaughterhouse in order to prevent the entry of carriers and control carcass contamination., Competing Interests: the authors declare no potential conflict of interest.

In seven EC swine abattoirs Salmonella prevalence (ISO 6579/2002) and serotypes of 25 piglets, 61 finishing pigs (lymph nodes, colon content, carcass and liver surface) and slaughterhouse environments (scalding water, surfaces in contact with meat and not in contact with meat) were investigated. Moreover, aerobic colony count [total viable count (TVC); ISO 4833] and Enterobacteriaceae (ISO 21528-2) of piglets and finishing pigs' carcasses were evaluated, and the results compared with EU process hygiene criteria (Reg. EC 2073/2005). Salmonella was not isolated in any of the piglets samples. Prevalence differed between slaughterhouses (P<0.5), and Salmonella was isolated from 39 of 244 samples of finishing slaughtered pigs (15.9%) and from 4 of 45 environmental samples (8.9%). In pig samples, carcasses showed the highest prevalence (18%) followed by colon content (14.8%), lymph nodes (13%) and liver (1.6%). S . Anatum was the most prevalent serotype (71.8%), followed by S . Derby (33.3%), S . Bredeney (5%) and S . Holcomb (2.5%). Between environmental samples, S . Anatum (50%), S . Bredeney and S . Derby (25%) were identified. Total viable mean counts (log 10 CFU/cm 2 ) of carcass surfaces ranged from 4.6 and 5.7 for piglets, and from 4.6 and 5.9 for finishing pigs, while Enterobacteriaceae ranged between 1.1 and 5 for piglets and between 2.1 and 5.3 for finishing pigs. These results were not in compliance with EU performance criteria. Total aerobic viable counts and Enterobacteriaceae mean levels of environmental samples appeared critical, particularly referred to surfaces in contact with meat (splitting equipment) and indicated an inadequate application of good manufacturing and hygiene practices during slaughtering and sanitisation., Competing Interests: the authors declare no potential conflict of interests.

Bivalve molluscs are a well documented source of viral infection. Further data on shellfish viral contamination are needed to implement European Regulations with sanitary measures more effective against viral pathogens. To this aim, 336 samples of bivalve molluscs (185 mussels, 66 clams, 23 oysters and 62 samples from other species) collected in harvesting areas of class A and B of four Italian Regions were analyzed for qualitative and quantitative determination of hepatitis A virus (HAV) and Norovirus (NoV) GI and GII, using real time RT-PCR. The results showed a wide diffusion of viral contamination in the shellfish production areas considered. HAV prevalence was low (0.9%) with contamination levels that varied from 5 to 7 × 10(2)copies/g. On the contrary, NoV showed a high prevalence (51.5%), with a large variability according to the group considered (e.g. 47.8% for Crassostrea in Veneto, 79.7% for Mytilus in Campania, 84.6% for Tapes in Sardinia). NoV contamination affected class A and class B production areas to a different extent, with a statistically significant difference in both contamination prevalence (22.1% vs. 66.3%; p<0.0001) and quantity (average contamination level of 3.1 × 10(2) vs. 1.9 × 10(3) copies/g; p<0.05). The different species analyzed from class B harvesting areas (Mytilus, Tapes/Ruditapes and Crassostrea) showed a NoV prevalence respectively of 70.3%, 66.0% and 47.8% but comparable NoV contamination levels (between 8.4 × 10(2) and 4.9 × 10(3)copies/g). Other two bivalve species considered in the study (Donax spp. and Solen spp.) showed a relevant NoV presence (40.0% and 34.4% of samples). Finally, samples analyzed before and after commercial purification treatment showed a decrease of contamination prevalence after the treatment, but inconsistent results were recorded on NoV levels. The data obtained, together with other quantitative information to estimate consumer exposure, in association with studies on dose-response and on the effectiveness of post-harvest treatments, will provide a useful tool for the definition of microbiological criteria related to the different shellfish species., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Vibrio parahaemolyticus is a marine microorganism, recognized as an important cause of foodborne illness particularly in Asia, South America and United States. Outbreaks are rarely reported in Europe, but they can occur unexpectedly in relation, among other reasons, to the spread of highly virulent strains. It is known that the risk is proportional to exposure levels to pathogenic V. parahaemolyticus (i.e. carrying the tdh and/or the trh genes) but currently there is a lack of occurrence data for pathogenic V. parahaemolyticus in shellfish production areas of the Member States. In this study a total of 147 samples of bivalve molluscs, from harvesting areas of two Italian regions (Sardinia and Veneto) were analyzed for Escherichia coli and salmonella, according to Reg 2073/2005, and for detection and enumeration of total and toxigenic V. parahaemolyticus strains using a new DNA colony hybridization method. Environmental parameters (water temperature and salinity) were also recorded. Results of E. coli were consistently in agreement with the legislation limits for the harvesting class of origin and Salmonella was detected only in one sample. The average contamination levels for total V. parahaemolyticus were 84 and 73 CFU/g respectively for Sardinia and Veneto, with the highest value reaching 8.7 × 10(3)CFU/g. Nineteen samples (12.9%) resulted positive for the presence of potentially pathogenic V. parahaemolyticus strains, with levels ranging between 10 and 120 CFU/g and most of the positive samples (n=17) showing values equal or below 20 CFU/g. A significant correlation (r=0.41) was found between water temperature and V. parahaemolyticus levels, as well as with isolation frequency. The data provided in this study on contamination levels of total and potentially pathogenic V. parahaemolyticus, seasonal distribution and correlation with water temperature, will help in defining appropriate monitoring programs and post-harvest policies for this hazard, improving the management of the harvesting areas and the safety of bivalve molluscs., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The aim of the present study was to investigate the occurrence of Listeria monocytogenes in ten Sardinian fermented sausage processing plants. A total of 230 samples were collected and 40 L. monocytogenes isolates were obtained and subjected to serotyping and investigated for the presence of ten virulence-associated genes using multiplex PCR assays. The isolates were further subjected to PFGE and investigated for their adhesion abilities in polystyrene microtiter plates. L. monocytogenes was found in 6% of food contact surfaces, in sausages at the end of acidification (3%) and ripening (8%). Serotyping revealed the presence of four serovars: 1/2c (37.5%), 1/2b (27.5%), 4b (22.5%) and 1/2a (12.5%). All virulence-associated genes were detected in 67.5% of the isolates. Isolates from processing environment, semi-processed and finished products showed high pulsotype diversity and the majority of isolates presented weak adhesion capability. The detection of the pathogen in fermented sausages confirms the ability of L. monocytogenes to overcome the hurdles of the manufacturing process., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Listeria monocytogenes is of major concern in the fermented meat products and is able to persist in their processing environments. The aim of the present work was to evaluate the virulence profile and the persistence capacity of L. monocytogenes strains isolated in Sardinian fermented sausages processing plants. Food (ground meat, sausages at the end of acidification and ripening stage) and environmental samples (a total of n. 385), collected from 4 meat processing plants located in Sardinia (Italy), were examined to detect L. monocytogenes presence. All the L. monocytogenes isolates were identified by polymerase chain reaction (PCR) method. A subset of strains was also characterised by multiplex PCR-based serogrouping, using the lmo0737 , lmo1118 , ORF2819 and ORF2110 genes. Three different multiplex PCRs were used to obtain the virulence profiles by the rrn , hlyA , actA , prfA , inlA , inlB , iap , plcA , plcB and mpl marker genes. Furthermore, in vitro biofilm forming ability and resistance to disinfectants were carried out on microtiter plate. The overall prevalence was 31.5% in food, and 68.5% in environmental samples. The prevalent serotype resulted 1/2c (43%), followed by 1/2a (40%), 4b (8.6%), and 1/2b (8.6%). The amplification products of the virulence genes were found in all the isolates with the following prevalence: 77.1% hlyA ; 100% rrn ; 100% prfA ; 97.1% iap ; 65.7% inlB ; 88.6% inlA ; 100% plcA ; 100% plcB and 74.3% mpl . As for biofilm forming ability, 37.1% of the strains were positive and resulted weak producer, but all the isolates were sensible to disinfectants showing a reduction of L. monocytogenes growth after each incubation time. More appropriate technologies and application of measures of hygienic control should be implemented to prevent the L. monocytogenes growth and cross-contamination in salsiccia sarda processing plants., Competing Interests: the authors declare no potential conflict of interests

Reverse transcription combined with the polymerase chain reaction (RT-PCR) is a viable method widely used to quantify gene expression. There are two ways to quantify gene expression by real-time PCR: relative quantification and absolute quantification. Relative quantification relates the PCR signal of the target gene to a control gene, normally a housekeeping gene. Absolute quantification determines the input copy number, usually by relating the PCR signal to a standard curve. Here we describe both methods from RNA extraction to its quantification by real-time PCR.

In a 3-year study (2008 to 2011) to estimate the prevalence and the contamination sources of Listeria monocytogenes in pork meat in Sardinia, Italy, 211 samples were collected from five Sardinian swine slaughterhouses: 171 samples from slaughtered pigs and 40 from the slaughterhouse environment. Fifty L. monocytogenes isolates were characterized by PCR-based serotyping, presence of virulence-associated genes, and pulsed-field gel electrophoresis restriction analysis. The overall prevalence of L. monocytogenes was 33% in swine carcasses, 7% in cecal material, 23% on meat contact surfaces, and 25% on noncontact surfaces. Only two serotypes were detected: 1/2c (78%) and 1/2a (22%). In all, based on the presence of virulence-associated genes, eight pathogenic profiles were detected. Only 42% of all isolates carried the full complement of virulence-associated genes and were allotted to profile 1. Six pulsed-field gel electrophoresis profiles persisted in the slaughterhouses; restriction profiles appeared to be specific to each plant.

The aim of the present study was to investigate the sources of Listeria monocytogenes contamination in a cold smoked salmon processing environment over a period of six years (2003-2008). A total of 170 samples of raw material, semi-processed, final product and processing surfaces at different production stages were tested for the presence of L. monocytogenes. The L. monocytogenes isolates were characterized by multiplex PCR for the analysis of virulence factors and for serogrouping. The routes of contamination over the six year period were traced by PFGE. L. monocytogenes was isolated from 24% of the raw salmon samples, 14% of the semi-processed products and 12% of the final products. Among the environmental samples, 16% were positive for L. monocytogenes. Serotyping yielded three serovars: 1/2a, 1/2b, 4b, with the majority belonging to serovars 1/2a (46%) and 1/2b (39%). PFGE yielded 14 profiles: two of them were repeatedly isolated in 2005-2006 and in 2007-2008 mainly from the processing environment and final products but also from raw materials. The results of this longitudinal study highlighted that contamination of smoked salmon occurs mainly during processing rather than originating from raw materials, even if raw fish can be a contamination source of the working environment. Molecular subtyping is critical for the identification of the contamination routes of L. monocytogenes and its niches into the production plant when control strategies must be implemented with the aim to reduce its prevalence during manufacturing., (Copyright © 2012 Elsevier B.V. All rights reserved.)

In order to improve the knowledge about the presence of Salmonella in pork meat in Sardinia (Italy), the prevalence and the sources of Salmonella at 5 pig slaughterhouses (slaughtered pigs and environment) were investigated and the isolates were characterised. A total of 462 samples were collected, 425 from pigs at slaughter and 41 from the slaughterhouse environment. Salmonella was isolated from 26/85 (30.5%) mesenteric lymph nodes, 14/85 (16.4%) colon contents, and from 12/85 (14.1%) carcasses and livers. Salmonella prevalence was 38% (8/21) in samples from surfaces not in contact with meat, and 35% (7/20) in those from surfaces in contact with meat. Thirty-one pigs were identified as carriers of Salmonella in lymph nodes and/or colon content, but of these, only 8 carcasses were positive. A total of 103 Salmonella isolates were serotyped and genotyped. Eight different serotypes were detected; the most common were S. Derby (44/103, 42.7%) and S. Typhimurium (24/103, 23.3%). The most prevalent S. Typhimurium phage type was DT193. Thirty-two isolates were found to be resistant to more than one antimicrobial (MDR). Pulse-field gel electrophoresis (PFGE) permitted the resolution of XbaI macrorestriction fragments of the Salmonella strains into 20 distinct pulsotypes. Combined application of a plasmid profiling assay (PPA) and PFGE gave useful additional information to assist in tracing the routes of Salmonella contamination in abattoirs. To reduce Salmonella prevalence some preventive measures should be encouraged: the origin of infected slaughter animals should be identified and direct and cross-contamination of carcasses should be avoided by adhering to HACCP principles in association with good hygiene procedures (GHP)., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The aims of the present study were: (a) to investigate the prevalence and the enumeration of Listeria monocytogenes in 200 samples of ready to eat (RTE) foods of animal and vegetal origin collected from different outlets and processing plants in Sardinia; (b) to characterize the isolates by phenotypical and molecular methods; (c) to analyze a subset of 42 L. monocytogenes by automated EcoRI ribotyping in order to predict the strain's potential virulence for humans. The strains were isolated from: smoked fish products, cooked marinated products, meat products and pre-packaged mixed vegetable salads. Of the samples tested, 22% were positive for Listeria spp. The prevalence of L. monocytogenes was 9.5%, while the level of L. monocytogenes in the positive samples was <10 cfu/g in 94.7% of cases. EcoRI ribotyping differentiated the isolates into 16 distinct ribotypes (similarity>93%), belonging to 17 different DuPont Identification Library Codes (DUP-IDs) clones. The Simpson's numerical index of discrimination was 0.911. Cluster analysis pointed out a high similarity among strains isolated from meat, fish, and vegetables of different origin. These results confirmed the existence of a widespread population of L. monocytogenes, characterized by highly related strains existing in different geographical areas. 65% of these strains belonged to lineage II (serotypes 1/2a and 1/2c), subtypes known to be associated with sporadic human listeriosis outbreaks. The remaining 35% of the isolates (serotypes 1/2b, 3b and 4b) were allocated to lineage I and belong to distinct clonal groups (DUP-ID 1038 and 1042), which again have been associated with several outbreaks of human listeriosis. Neither atypical profiles nor lineage III strains were found. EcoRI ribotyping was confirmed as a rapid and reliable method for L. monocytogenes typing, providing useful data for epidemiologic and clonality surveys of L. monocytogenes strains isolated from RTE foods.

The total lipids of the longissimus dorsi muscle were analyzed from commercial adult Sarda sheep in Sardina taken from local abattoirs, and in the subsequent year from three local farms in the Sassari region that provided some information on the amount and type of supplements fed to the pasture-fed sheep. The complete lipid analysis of sheep meat included the fatty acids from O-acyl and N-acyl lipids, including the trans- and conjugated linoleic acid (CLA) isomers and the alk-1-enyl ethers from the plasmalogenic lipids. This analysis required the use of a combination of acid- and base-catalyzed methylation procedures, the former to quantitate the O-acyl, N-acyl and alkenyl ethers, and the latter to determine the content of CLA isomers and their metabolites. A combination of gas chromatographic and silver-ion separation techniques was necessary to quantitate all of the meat lipid constituents, which included a prior separation of the trans-octadecenoic acids (18:1) and a separation of fatty acid methyl esters and the dimethylacetals (DMAs) from the acyl and alk-1-enyl ethers, respectively. The alk-1-enyl moieties of the DMAs were analyzed as their stable cyclic acetals. In general, about half of the meat lipids were triacylglycerols, even though excess fat was trimmed from the meat. The higher fat content in the meat appears to be related to the older age of these animals. The variation in the trans-18:1 and CLA isomer profiles of the Sarda sheep obtained from the abattoirs was much greater than in the profiles from the sheep from the three selected farms. Higher levels of 10t-18:1, 7t9c-18:2, 9t11c-18:2 and 10t12c-18:2 were observed in the commercial sheep meat, which reflected the poorer quality diets of these sheep compared to those from the three farms, which consistently showed higher levels of 11t-18:1, 9c11t-18:2 and 11t13c-18:2. In the second study, sheep were provided with supplements during the spring and summer grazing season, which contributed to higher levels of 11t-18:1 and 9c11t-18:2. The farm that provided a small amount of supplements during the spring had the better lipid profile at both time periods. The polyunsaturated fatty acid (PUFA) content was higher in the meat from Sarda sheep from the three farms than in the meat from those sheep obtained from commercial slaughter operations. The plasmalogenic lipid content ranged from 2 to 3% of total lipids, the alk-1-enyl ethers consisted mainly of saturated and monounsaturated moieties, and the trans-18:1 profile was similar to that of the FA. The n-6 (6-8%) and n-3 PUFA (2-3%) contents, the n-6/n-3 ratio (3:1), as well as the saturated fatty acid (SFA) content (42-45%) and the SFA to PUFA ratio (4:1 to 5:1) of the Sarda sheep from the three farms were comparable to sheep meat lipids found in similar commercial operations in Europe. Inclusion of small amounts of supplements for the grazing Sarda sheep resulted in improved quality of sheep meat lipids.

The authors report the results of an experimental infection of 20 chickens with L.m. in order to verify if they became affected by Listeriosis and to individuate the degree of contamination of the meat and parenchymas and eggs. Despite the high infecting dose (160 x 10(7) micro-organism in group 1, 51 x 10(8) + cortisone in group 2, 130 x 10(8) in group 3), no signs of the disease were found in any of the animals; besides, L.m. was isolated in the faeces of only 3 subjects for 1 day post-infection and in the organs of 4 subjects for a maximum of 15 days post-infection. From a histopathological point of view only simple lymphocytic-macrophagic and eosinophilic proliferations localized in the liver and, to a lesser extent, in other parenchymas were observed. The authors advance the hypothesis that the frequent isolations of L.m. in chicken meat and eggs can be attributed to exogenous contamination in stages of slaughtering and marketing of the product.

Sensitivity of Bacillus subtilis BGA and Bacillus stearothermophilus var. calidolactis disc assays to 53 chemio-antibiotics was tested. Test-microorganisms were sown in two different mediums: PM Indicator Agar, Difco U.S.A., and Standard II Nutrient Agar, Merck Germany, modified according to Nouws. The mediums were used with or without addition of Trimethoprim (at a concentration of 0.12 or 0.024 mcg/ml of medium for B. subtilis and for B. stearothermophilus respectively). B. stearothermophilus did not grow in Standard II. However, the B. subtilis assay gave the best results with Standard II, apart for aminoglycosides. The B. stearothermophilus disc assay was the most sensitive to penicillins (Minimum Inhibiting Concentration in mcg/ml, MIC, between 0.001 and 0.004), cephalosporins (MIC between 0.003 and 0.09, apart from Ceftazidime, 0.3) and aminoglycosides (MIC between 0.03 and 0.6). The B.subtilis disc assay showed better sensitivity to quinolines (MIC between 0.05 and 4) and to some tetracyclines (oxytetracycline and chlortetracycline, MIC 0.03). Trimethoprim, where added, determined a higher sensitivity to sulfonamides (MIC between 0.025 and 0.25).