Prevalence, antimicrobial susceptibility, and genetic characteristics of Staphylococcus aureus from retail ready-to-eat foods and vegetables in some regions of China
Acta Microbiologica Sinica,Vol 58,No. 02
【Abstract】 [Objective] To investigate the prevalence, antimicrobial susceptibility, and genetic characteristics of Staphylococcus aureus from ready-to-eat foods (stewed meat, roast, salad and pasteurized milk) and vegetables from 15 representative cities of China and to provide baseline information for effective tracing S. aureus source and controlling food contamination. [Methods] All samples were subjected to qualitative and most probable number (MPN) analysis for S. aureus according to the National Food Safety Standard-Food Microbiological Examination: S. aureus. Antimicrobial susceptibility of all isolates was evaluated using the Kirbye-Bauer disk diffusion and mecA-positive isolates was obtained by PCR. The sequence types of S. aureus were performed via multilocus sequence typing (MLST). [Results] In all the 540 food samples, 9.3% (50/540) were tested positive for S. aureus, of which the most polluted food was stewed meat (16.3%, 30/184), followed by roast (9.2%, 6/65), and vegetable showed the lowest prevalence (4.0%, 6/150). Most probable number (MPN) analysis showed that 62.0% samples ranged from 0.3 to 1 MPN/g, and three samples exceeded 110 MPN/g. A total of 82.0% isolates were resistant to ampicillin and penicillin G, and 64.0% isolates were multi-drug resistant. In addition, the mecA-positive isolates both belonged to the SCCmec IVa subtype using staphylococcal cassette chromosome mec (SCC mec) typing. Furthermore, 14 sequence types (STs) were obtained by MLST, including two novel STs (ST3595 and ST3847). [Conclusion] The general multi-drug resistance exhibited by S. aureus was still the most serious issue of common concern, which posed a health risk for consumers. In addition, the antimicrobial susceptibility of S. aureus was highly associated with STs. Therefore, it is necessary to provide scientific data for further analysis of epidemic trends and risk assessment of bacteria prevalent in foods.
Chinese Journal of Biotechnology,Vol 34,No. 08
【Abstract】 World Health Organization has recognized that antibiotic resistance is one of the serious threats to public health and food safety in the 21st century. Recently, the antibiotic resistance gene (ARG) has been widely considered as a new pollutant. Now, many studies suggest that animal farm is one of the major reservoirs of ARGs. Antibiotic resistant bacteria and ARGs enter the environment along with animal excrement, accelerating the spread of ARGs in the environment. In the livestock and poultry breeding environment, ARGs and antibiotic resistant bacteria could be transmitted to humans through the food chain, water or air, posing a great threat to public health. This review highlights the prevalence of antibiotic resistant bacteria and ARGs in livestock-breeding environment, the retention and spread of ARGs and the method used to study the antibiotic resistance, which will provide certain support for risk assessment of antimicrobial resistance in food animal breeding environment.
Finance & Trade Economics,Vol 39,No. 08
【Abstract】 In recent years, China’s food imports have increased substantially. This is a new issue that cannot be fully explained only from the perspective of supply side, and a satisfactory explanation cannot be given from the perspective of agricultural trade liberalization. In this paper, the dynamic panel system GMM estimation was applied in the empirical analysis to explore the impact of the overlapping income distributions between China and import source countries on the varieties of China’s imported food. The study found that under the premise of controlling per capita income in China, the degree of overlap in the distribution of income between China and the country of importation has a significant positive impact on the diversification of China’s imported food. In addition, the study also found that the impact of the degree of overlap in the distribution of income between China and the import partner on the number of varieties of China’s imported food largely differed from country to country. Although Chinese consumers prefer to imported food products from developed countries, the increase in the overlapping degree of income distribution has a greater impact on the growth of the variety of imported food from developing countries than that from developed countries. This paper proposes creating conditions for importing more varieties of food from countries which have a high degree of income distribution overlap with China, and make a point of importing high-quality food from developed countries and importing varieties of food from developing countries.