Validation of real-time PCR technique for detection of Mycobacterium bovis and Brucella abortus in bovine raw milk

High-Performance Detection of Mycobacterium bovis in Milk Using Recombinase-Aided Amplification-Clustered Regularly Interspaced Short Palindromic Repeat-Cas13a-Lateral Flow Detection

Mycobacterium bovis (M. bovis), the microorganism responsible for bovine tuberculosis (bTB), is transferred to people by the ingestion of unpasteurized milk and unprocessed fermented milk products obtained from animals with the infection. The identification of M. bovis in milk samples is of the utmost importance to successfully prevent zoonotic diseases and maintain food safety. This study presents a comprehensive description of a highly efficient molecular test utilizing recombinase-aided amplification (RPA)-clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein (Cas) 13a-lateral flow detection (LFD) for M. bovis detection. In contrast to ELISA, RPA-CRISPR-Cas13a-LFD exhibited greater accuracy and sensitivity in the detection of M. bovis in milk, presenting a detection limit of 2 × 100 copies/μL within a 2 h time frame. The two tests exhibited a moderate level of agreement, as shown by a kappa value of 0.452 (95%CI: 0.287-0.617, p < 0.001). RPA-CRISPR-Cas13a-LFD holds significant potential as a robust platform for pathogen detection in complex samples, thereby enabling the more dependable regulation of food safety examination, epidemiology research, and medical diagnosis.

A systematic analysis of and recommendations for public health events involving brucellosis from 2006 to 2019 in China

Brucellosis is a severe public health problem in China. However, analysis on related infection events is lacking. We performed a systematic analysis of brucellosis laboratory infection and vaccine infection events from 2006 to 2019 in China based on the published literatures. Our analysis showed that most laboratoryBrucellainfections in hospitals were found in Southern China. The identification and handling of suspected samples ofBrucellainfection without following the recommended biosafety protection was the main risk factor. It is important to strengthen the preventive awareness of clinical laboratory staff and physicians, while highlighting the compulsory handling and identification of suspectedBrucella-infected samples in biosafety facilities and following biosafety practices. However, a severe Brucella infection accident at the Northeast Agricultural University, with 28 positive cases, showed that strengthening the management in teaching experiments of students in the veterinary-related profession is essential. However, cluster S2 vaccine strain infection events caused by vaccination and production were mainly observed in Northern China. Strengthening vaccination skills, personal protection, and improving the biosafety management of vaccine production and implementing regular risk surveillance is mandatory. Our analysis provides helpful clues for control of public health events involving brucellosis, as well as implementing intervention strategies is urgent.

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.