Evaluation of Immunomagnetic Separation–Polymerase Chain Reaction in Direct Detection ofBrucella abortusandBrucella melitensisfrom Cheese Samples

Recovery of Brucella in raw milk Minas artisanal cheese approved for consumption by official inspection agency in Brazil: assessment of prevalence and risk factors through One Health integrated approaches

BACKGROUND

Minas artisanal cheese (MAC) from the Serro region is a Brazilian intangible cultural heritage. Produced from raw milk, it may carry zoonotic pathogens such as Brucella. This study included a randomized survey for the prevalence of Brucella-positive MAC and its associated factors.

METHODS

MAC samples (n=55), each one from a different rural family-based cheese-processing agroindustry, were analysed for Brucella by direct polymerase chain reaction (PCR) species-specific DNA detection and cultivation-based approaches.

RESULTS

Among 55 MACs that were analysed, we found 17 Brucella DNA-positive samples (30.9% [95% confidence interval {CI} 18.7 to 43.1]) by PCR and, for the first time, from one MAC (1.8% [95% CI 0.5 to 9.7]), viable Brucella abortus was recovered by cultivation. Higher values for two variables, the number of lactating cows per herd (p=0.043) and daily milk production per herd (p=0.043), were each associated with Brucella-positive MAC, which concentrated in three high-risk and one low-risk spatial clusters.

CONCLUSIONS

MAC may be a source of Brucella for humans, since the positive samples were from batches that were sold by cheesemakers. This should be of concern and encourage cooperation between the health and agriculture sectors in order to mitigate this public health risk through One Health integrated approaches.

Comparative Review of Brucellosis in Small Domestic Ruminants

Brucella melitensis and Brucella ovis are the primary etiological agents of brucellosis in small domestic ruminants. B. melitensis was first isolated in 1887 by David Bruce in Malta Island from spleens of four soldiers, while B. ovis was originally isolated in Australia and New Zealand in early 1950's from ovine abortion and rams epididymitis. Today, both agents are distributed worldwide: B. melitensis remains endemic and associated with an extensive negative impact on the productivity of flocks in -some regions, and B. ovis is still present in most sheep-raising regions in the world. Despite being species of the same bacterial genus, B. melitensis and B. ovis have extensive differences in their cultural and biochemical characteristics (smooth vs. rough colonial phases, serum and CO2 dependence for in vitro growth, carbohydrate metabolism), host preference (female goat and sheep vs. rams), the outcome of infection (abortion vs. epididymitis), and their zoonotic potential. Some of these differences can be explained at the bacterial genomic level, but the role of the host genome in promoting or preventing interaction with pathogens is largely unknown. Diagnostic techniques and measures to prevent and control brucellosis in small ruminants vary, with B. melitensis having more available tools for detection and prevention than B. ovis. This review summarizes and analyzes current available information on: (1) the similarities and differences between these two etiological agents of brucellosis in small ruminants, (2) the outcomes after their interaction with different preferred hosts and current diagnostic methodologies, (3) the prevention and control measures, and (4) alerting animal producers about the disease and raise awareness in the research community for future innovative activities.

Detection of Potential Microbial Contaminants and Their Toxins in Fermented Dairy Products: a Comprehensive Review

Fermented dairy products are dominant constituents of daily diets around the world due to their desired organoleptic properties, long shelf life, and high nutritional value. Probiotics are often incorporated into these products for their health and technological benefits. However, the safety and possible contamination of fermented dairy products during the manufacturing process could have significant deleterious health and economic impacts. Pathogenic microorganisms and toxins from different sources in fermented dairy products contribute to outbreaks and toxicity cases. Although the health and nutritional benefits of fermented dairy products have been extensively investigated, safety hazards due to contamination are relatively less explored. As a preventive measure, it is crucial to accurately identify and determine the associated microbiota or their toxins. It is noteworthy to highlight the importance of detecting not only the pathogenic microbiota but also their toxic metabolites so that putative outbreaks can thereby be prevented or detected even before they cause harmful effects to human health. In this context, this review focuses on describing techniques designed to detect potential contaminants; also, the advantages and disadvantages of these techniques were summarized. Moreover, this review compiles the most recent and efficient analytical methods for detecting microbial hazards and toxins in different fermented dairy products of different origins. Causative agents behind contamination incidences are also discussed briefly to aid in future prevention measures, as well as detection approaches and technologies employed. Such approach enables the elucidation of the best strategies to control contamination in fermented dairy product manufacturing processes.

Microbial safety status of Serro artisanal cheese produced in Brazil

Considering the growing consumption of artisanal foods worldwide, we aimed to evaluate the microbial safety of Serro artisanal cheese (SAC), produced in Minas Gerais State, Brazil. This cheese is produced with raw milk using 1 of 2 natural starter cultures: "pingo" and "rala." A total of 53 SAC samples (pingo = 8; rala = 45) were obtained from different farmers and subjected to conventional and molecular assays to detect and enumerate Listeria monocytogenes, Salmonella spp., coagulase-positive staphylococci (CPS), diarrheagenic Escherichia coli, Mycobacterium tuberculosis, and Brucella abortus. The SAC samples were also subjected to an ELISA to detect classical staphylococcal enterotoxins (CSE: SEA, SEB, SEC, SED, SEE) and to PCR assays to detect staphylococcal enterotoxin-related genes (sea, seb, sec, sed, see). Coagulase-positive staphylococci isolates were obtained and tested by the same assays to detect their potential in CSE production and presence of CSE-related genes. None of the SAC samples showed any of the screened food-borne pathogens and zoonotic agents, and none showed the presence of CSE by phenotypic and genotypic approaches. Despite the absence of microbial hazards, mean counts of CPS in SAC samples were 5.2 log cfu/g (pingo starter) and 4.6 log cfu/g (rala starter), indicating poor hygiene practices during production. None of the tested CPS isolates (n = 116) produced CSE or presented CSE-related genes. Despite the relative microbial safety, hygienic conditions during SAC production must be improved to meet official guidelines established in Brazil.

Brucella abortus detected in cheese from the Amazon region: differentiation of a vaccine strain (B19) from the field strain in the states of Pará, Amapá and Rondônia, Brazil

Abstract: Brucellosis is an infectious-contagious disease responsible for significant economic losses to the meat and milk supply chain, because it causes reproductive disorders in animals and is a chronic anthropozoonosis. This study was designed to detect the DNA of Brucella spp. in cheese and to differentiate between a vaccine strain (B19) and the field strain. Sixty-six samples of different cheeses which are produced and marketed in three states of the Brazilian Amazon region (Amapá [5 samples], Pará [55 samples] and Rondônia [6 samples]) were evaluated. Thirty-nine of these samples were from cheeses made from cow's milk, and 27 were from cheeses made from buffalo milk. Four of the 66 samples were from cheeses produced in milk processing plants regulated by the Federal Inspection Service (Serviço de Inspeção Federal); nine of the samples were from cheeses produced in processing plants regulated by the State Inspection Service (Serviço de Inspeção Estadual); five of the samples were from artisanal cheeses; and the remaining 48 samples were from informally produced cheese. DNA was obtained from the samples following a DNA extraction protocol, and PCR was conducted using primers B4 and B5 to detect Brucella spp. Primers eri1 and eri2 were used to differentiate the field strain from the B19 vaccine strain. The results showed that 21.21% (14/66) of the samples were positive for Brucella spp., of which 21.43% (3/14) were positive for the B. abortus field strain, and 7.14% (1/14) were identified as harboring vaccine strain B19. These results demonstrate that it is possible to identify Brucella spp. in cheese from the Amazon region using the PCR technique and to differentiate the B. abortus field strain from the B19 vaccine strain.

Brucellosis in Turkey -- an overview

Although almost a century has gone by since its first description in the country, Turkey has not been able to eradicate brucellosis, which remains a major public health problem. In this review, we give an overview of the epidemiological and epizootic status of brucellosis in Turkey. Although little readily accessible data concerning the epidemiology of brucellosis in Turkey are available, the limited official and published data were analyzed. Despite being endemic in Turkey, brucellosis remains under-diagnosed and under-reported. Adherence to traditional farming practices and lifestyles and the consumption of fresh dairy produce contribute to the high incidence of brucellosis. The successful implementation of a national brucellosis control program requires strong political will, good funding, and collaboration, especially between the public health and veterinary sectors. Primary healthcare workers should always keep the symptoms of acute and chronic brucellosis in mind when treating patients.