Antibiotics, disinfectants and bacteria resistant to them have been detected in environmental compartments such as waste water, surface water, ground water, sediments and soils. Antibiotics are released into the environment after their use in medicine, veterinary medicine and their employment as growth promoters in animal husbandry, fish farming and other fields. There is increasing concern about the growing resistance of pathogenic bacteria in the environment, and their ecotoxic effects. Increasingly, antibiotic resistance is seen as an ecological problem. This includes both the ecology of resistance genes and that of the resistant bacteria themselves. Little is known about the effects of subinhibitory concentrations of antibiotics and disinfectants on environmental bacteria, especially with respect to resistance. According to the present state of our knowledge, the impact on the frequency of resistance transfer by antibacterials present in the environment is questionable. The input of resistant bacteria into the environment seems to be an important source of resistance in the environment. The possible impact of resistant bacteria on the environment is not yet known. Further research into these issues is warranted.

Resistance in the Environment

Toxoplasmosis in sheep--the last 20 years.

Background Meat is a perishable product and during storage, the actions of microorganisms and endogenous enzymes result in chemical compositional changes. Total volatile basic nitrogen (TVB-N) is often used as a biomarker of protein and amine degradation. The broad adoption of TVB-N to interpret meat freshness is somewhat restricted. This is the result of limited or inconsistent knowledge pertaining to the association between TVB-N and other freshness parameters, for beef, sheep/goat meat, pork, chicken and other types of meat, especially when compared to fish. Current meat studies have failed to address the mechanisms between TVB-N generation and production, processing and preservation strategies. Scope and approach Etiology of spoilage and freshness indicators in fresh meat are discussed and various mechanisms contributing to meat spoilage are highlighted. Further, the use and application of TVB-N for understanding the freshness of different meat types has been comprehensively reviewed with the aim of establishing its usefulness as a freshness marker. Key Findings and Conclusions TVB-N increases with meat storage and is aligned with other biomarkers of spoilage (i.e. function of duration, temperature, packaging, etc.). But these increases are not always consistent. There are different recommendations of TVB-N limits for meat freshness. These are primarily for fish and seafood products and therefore inappropriate for other meat types, are species specific, arbitrary, or have an element of ambiguity (e.g. an intermediary ‘stale’ classification between fresh and spoilt states). The selection of TVB-N limits can therefore introduce inaccuracy and subjectivity into the appraisal of meat freshness. Several destructive and non-destructive methods have been used to determine TVB-N, however, their capacity is limited to the differential between spoilt and non-spoilt samples through chemometric classification systems based on predefined TVB-N guidelines. Further reference populations and investigations of red meat types are required.

Total volatile basic nitrogen (TVB-N) and its role in meat spoilage: A review

Surface hygiene is commonly measured as a part of the quality system of food processing plants, but as the bacteria present are commonly not identified, their roles for food quality and safety are not known. Here, we review the identity of residential bacteria and characteristics relevant for survival and growth in the food industry along with potential implications for food safety and quality. Sampling after cleaning and disinfection increases the likelihood of targeting residential bacteria. The increasing use of sequencing technologies to identify bacteria has improved knowledge about the bacteria present in food premises. Overall, nonpathogenic Gram-negative bacteria, especially Pseudomonas spp., followed by Enterobacteriaceae and Acinetobacter spp. dominate on food processing surfaces. Pseudomonas spp. persistence is likely due to growth at low temperatures, biofilm formation, tolerance to biocides, and low growth requirements. Gram-positive bacteria are most frequently found in dairies and in dry production environments. The residential bacteria may end up in the final products through cross-contamination and may affect food quality. Such effects can be negative and lead to spoilage, but the bacteria may also contribute positively, as through spontaneous fermentation. Pathogenic bacteria present in food processing environments may interact with residential bacteria, resulting in both inhibitory and stimulatory effects on pathogens in multispecies biofilms. The residential bacterial population, or bacteriota, does not seem to be an important source for the transfer of antibiotic resistance genes to humans, but more knowledge is needed to verify this. If residential bacteria occur in high numbers, they may influence processes such as membrane filtration and corrosion.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/1541-4337.12283

Residential Bacteria on Surfaces in the Food Industry and Their Implications for Food Safety and Quality

Bacterial diversity in typical Italian salami at different ripening stages as revealed by high-throughput sequencing of 16S rRNA amplicons.

All hosts, including humans, can be infected by any one of the three forms of the parasite Toxoplasma gondii that correspond to three morphological stages: tachyzoite, bradyzoite, and sporozoite form. Felids are definitive hosts for T. gondii, which is an intracellular pathogen that infects a wide range of warm-blooded intermediate hosts. Toxoplasmosis is a disease where the interest of the diverse medical and veterinary specialties converge. Awareness needs to be increased that toxoplasmosis can induce clinical disease not only in immunocompromised patients or through congenital infections, but also in healthy patients. This is a review article that aims at illustrating why toxoplasmosis should be regarded a veterinary public health issue and how veterinary practitioners can contribute in controlling the infection.

/pdf/toxoplasma-in-animals-food-and-humans-an-old-parasite-of-new-1a0jrkdrb4.pdf

Toxoplasma in animals, food, and humans: an old parasite of new concern.

The shelf-life of a product is the period of time during which the food retains its qualitative characteristics. Bacteria associated with meat spoilage produce unattractive odours and flavours, discolouration, gas and slime. There are several neglected alterations that deserve more attention from food business operators and competent authorities. Ropy slime is a typical alteration of the surface of vacuum and modified atmosphere packed cooked meat products, that causes major economic losses due to the increasingly sophisticated consumer requirements. This is a review article that aims at raising awareness of an old problem of new concern, in the light of new advances and trends for understanding the aetiology of the phenomenon, the origins of contamination and the prevention measures.

Meat Spoilage: A Critical Review of a Neglected Alteration Due to Ropy Slime Producing Bacteria

Enterotoxin production by Staphylococcus aureus isolated from mastitic cows.

Religious slaughter: evaluation of current practices in selected countries

Serum samples from 600 sheep were collected from 5 different provinces randomly chosen in South Africa. Two sheep abattoirs (representing formal slaughter of sheep) and 1 rural location (representing informal slaughter of sheep) per province were also selected randomly. The serum samples were tested for anti-Toxoplasma gondii IgG antibodies using 2 different serological tests : an indirect fluorescent antibody (IFA) test and an enzyme-linked immunosorbent assay (ELISA) test available as a commercial kit. This study provides the first published data on seroprevalence of toxoplasmosis in sheep in South Africa, although positive titres have been found previously in wild felids, ferrets, chinchillas and a dog. Data on seroprevalence in sheep is considered important because consumption of mutton is universally considered to be a source of zoonotic transfer to humans. Seroprevalence in humans in South Africa was previously found to be 20% and it is postulated that this may be linked to the informal slaughter and consumption of mutton. During this study, the overall national seroprevalence per province in sheep was found to be 5.6 % (IFA) and 4.3 % (ELISA), respectively. This is lower than in other countries, possibly because South Africa has an arid climate. Differences in seroprevalence in different areas studied suggested an association with the climate and a significant correlation (P > 0.05) was detected between the prevalence of T. gondii and the minimum average temperature. The seroprevalence was found to be significantly higher (P < 0.01) in sheep originating from commercial farms (7.9 %) than in rural sheep in the informal sector (3.4 %). Also, sheep managed extensively had a seroprevalence of 1.8 %, which was significantly lower (P < 0.05) than the seroprevalence in sheep under semi-intensive or intensive management systems (5.3 %). An incidental finding of interest was the considerable movement of sheep to abattoirs and mutton after slaughter. The highest consumption of mutton was in the Western Cape Province (29.9 %) while the highest concentration of sheep is found in the Eastern Cape Province (30.1 %).

/pdf/seroprevalence-of-toxoplasmosis-in-sheep-in-south-africa-4ojqhuaqda.pdf

Beniamino T. Cenci-Goga

Papers

Toxoplasma in animals, food, and humans: an old parasite of new concern.

Meat Spoilage: A Critical Review of a Neglected Alteration Due to Ropy Slime Producing Bacteria

Enterotoxin production by Staphylococcus aureus isolated from mastitic cows.

Religious slaughter: evaluation of current practices in selected countries

Seroprevalence of toxoplasmosis in sheep in South Africa