鲆鲽类主要病原菌抗血清的制备及应用

用甲醛灭活8种鲆鲽类主要病原菌,鳗弧菌(Vibrio anguillarum)、创伤弧菌(Vibrio vulnificus)、哈维弧菌(Vibrio harveyi)、溶藻弧菌(Vibrio alginolyticus)、嗜水气单胞菌(Aeromonas hydrophila)、豚鼠气单胞菌(Aeromonas caviae)、迟缓爱德华菌(Edwardsiella tarda)、鮰爱德华菌(Edwardsiella ictaluri),制备成灭活疫苗后肌肉注射大菱鲆获得各病原菌抗血清。结果显示,抗鳗弧菌血清、抗哈维弧菌血清、抗豚鼠气单胞菌血清、抗鮰爱德华菌效价为1:6 400,抗创伤弧菌血清、抗溶藻弧菌血清、抗嗜水气单胞菌血清效价为1:12 800,抗迟缓爱德华菌血清效价为1:102 400。应用ELISA分析各抗血清与8种病原菌及迟缓爱德华菌蛋白的免疫交叉反应,结果显示,各病原菌与其本身的抗血清反应最为强烈,而与其他抗血清间有程度不等的交叉反应;菌蛋白与其相应的菌抗血清反应最为强烈,与其他病原菌抗血清反应较弱。本研究所制备的病原菌抗血清效价较高,且具有特异性,可应用于鲆鲽类病原菌的检测。     

Modelling and Prediction of Bacterial Attachment to Polymers

Infection by pathogenic bacteria on implanted and indwelling medical devices during surgery causes large morbidity and mortality worldwide. Attempts to ameliorate this important medical issue have included development of antimicrobial surfaces on materials, “no touch” surgical procedures, and development of materials with inherent low pathogen attachment. The search for new materials is increasingly being carried out by high throughput methods. Efficient methods for extracting knowledge from these large data sets are essential. Data from a large polymer microarray exposed to three clinical pathogens is used to derive robust and predictive machine‐learning models of pathogen attachment. The models can predict pathogen attachment for the polymer library quantitatively. The models also successfully predict pathogen attachment for a second‐generation library, and identify polymer surface chemistries that enhance or diminish pathogen attachment.     

Trends in microbial control techniques for poultry products

Fresh poultry meat and poultry products are highly perishable foods and high potential sources of human infection due to the presence of several foodborne pathogens. Focusing on the microbial control of poultry products, the food industry generally implements numerous preventive measures based on the Hazard Analysis and Critical Control Points (HACCP) food safety management system certification together with technological steps, such as refrigeration coupled to modified atmosphere packaging that are able to control identified potential microbial hazards during food processing. However, in recent years, to meet the demand of consumers for minimally processed, high-quality, and additive-free foods, technologies are emerging associated with nonthermal microbial inactivation, such as high hydrostatic pressure, irradiation, and natural alternatives, such as biopreservation or the incorporation of natural preservatives in packaging materials. These technologies are discussed throughout this article, emphasizing their pros and cons regarding the control of poultry microbiota and their effects on poultry sensory properties. The discussion for each of the preservation techniques mentioned will be provided with as much detail as the data and studies provided in the literature for poultry meat and products allow. These new approaches, on their own, have proved to be effective against a wide range of microorganisms in poultry meat. However, since some of these emergent technologies still do not have full consumer's acceptability and, taking into consideration the hurdle technology concept for poultry processing, it is suggested that they will be used as combined treatments or, more frequently, in combination with modified atmosphere packaging.     

The prevalence of Listeria, Salmonella, Escherichia coli and E. coli O157:H7 on bison carcasses during processing

Bison meat is a relatively new, emerging meat species gaining increased popularity in the US and European meat markets, but little is known of its microflora or pathogens that may be present. This study was carried out to determine the incidence of the foodborne pathogens Listeria, Salmonella, Escherichia coli/E. coli O157:H7 on slaughtered bison and to evaluate the bison slaughter process. Bison carcass sampling was carried out at monthly intervals over a period of 1 year at a Bison processing facility in the Midwestern United States. A total of 355 Bison carcasses were sampled by surface swabbing the carcasses at five points on the production line: pre-dehiding, post-evisceration, post-USDA inspection, post-washing and 24 h chilled carcass. Overall, the prevalence of Listeria spp., Salmonella spp., E. coli and E. coli O157:H7 was 18.3%, 3.94%, 38.3% and 1.13%, respectively. The prevalence of Listeria spp. at each sampling point tested was 42.24%, 18.1%, 6.03%, 1.72% and 3.77% while the prevalence of E. coli at each sampling point was: 88.79%, 73.28%, 52.59%, 56.89% and 11.3%, respectively. The data obtained suggests that current antimicrobial intervention strategies used at the plant are relatively effective in reducing Listeria and E. coli contamination on bison carcasses to some extent, however further study is required to determine the influence of current slaughter practices on carcass contamination. The data reported in this study to the authors’ knowledge is some of the first information reporting on the bacteriological status of Bison, and provides some useful baseline information for future research.     

2012—2020年江西省家庭食源性疾病暴发事件分析

目的 分析江西省家庭食源性疾病暴发事件的流行病学特征,为预防和有效控制家庭食源性疾病提供参考依据。方法 收集江西省2012—2020年食源性疾病暴发监测系统中报告的家庭食源性疾病暴发事件资料,采用描述性流行病学方法进行分析。结果 2012—2020年江西省共报告家庭食源性疾病暴发事件715起,累计发病2 608人,死亡35人,病死率为1.3%（35/2 608）。9年间暴发事件数整体呈上升趋势,事件集中发生在5~10月份。从致病因素和原因食品分析,野生蘑菇引起的事件数、发病人数和死亡人数最多,分别占总数的45.0%（322/715）、39.5%（1 029/2 608）和94.2%（33/35）,其次是微生物致病因素。从区域分析,家庭食源性疾病暴发事件主要发生在农村,报告的事件数、发病人数和死亡人数分别占总数的73.1%（527/715）、75.4%（1 966/2 608）和100.0%（35/35）。结论 江西省食源性疾病高发季节,应重点针对广大农村家庭开展食用野生蘑菇的危害性宣传,普及微生物性食源性疾病知识,减少家庭食源性疾病的发生,降低死亡率。     

The importance of lactic acid bacteria for the prevention of bacterial growth and their biogenic amines formation: A review

Foodborne pathogens (FBP) represent an important threat to the consumers' health as they are able to cause different foodborne diseases. In order to eliminate the potential risk of those pathogens, lactic acid bacteria (LAB) have received a great attention in the food biotechnology sector since they play an essential function to prevent bacterial growth and reduce the biogenic amines (BAs) formation. The foodborne illnesses (diarrhea, vomiting, and abdominal pain, etc.) caused by those microbial pathogens is due to various reasons, one of them is related to the decarboxylation of available amino acids that lead to BAs production. The formation of BAs by pathogens in foods can cause the deterioration of their nutritional and sensory qualities. BAs formation can also have toxicological impacts and lead to different types of intoxications. The growth of FBP and their BAs production should be monitored and prevented to avoid such problems. LAB is capable of improving food safety by preventing foods spoilage and extending their shelf-life. LAB are utilized by the food industries to produce fermented products with their antibacterial effects as bio-preservative agents to extent their storage period and preserve their nutritive and gustative characteristics. Besides their contribution to the flavor for fermented foods, LAB secretes various antimicrobial substances including organic acids, hydrogen peroxide, and bacteriocins. Consequently, in this paper, the impact of LAB on the growth of FBP and their BAs formation in food has been reviewed extensively.     

湖北省烟草靶斑病病原鉴定及其菌丝融合群遗传分化研究

2020—2021年湖北烟区爆发新型烟草叶部病害,本研究对病原菌进行分离培养、形态观察、镜检菌丝和科赫法则验证,并提取30个菌株的DNA使用通用引物ITS1/ITS4进行rDNA-ITS序列的PCR扩增,及MEGA-X软件进行基因序列比对及系统发育树构建,同时以Rs1F2/Rs2R1为引物,进行30个菌株的rDNA-ITS基因的PCR专化性鉴定。结果表明,该病害病原菌为立枯丝核菌（Rhizoctonia solani Kühn）,30个菌株序列都隶属于R. solani AG-3融合群且均具有AG-3融合群所特有的504 bp片段。因此,确定该病害为烟草靶斑病。这是首次从湖北省烟草产区分离鉴定到该病菌。     

Distribution of dimorphic yeast species in commercial extra virgin olive oil

Recent microbiological research has demonstrated the presence of a rich microflora mainly composed of yeasts in the suspended fraction of freshly produced olive oil. Some of the yeasts are considered useful as they improve the organoleptic characteristics of the oil during preservation, whereas others are considered harmful as they can damage the quality of the oil through the hydrolysis of the triglycerides. However, some dimorphic species can also be found among the unwanted yeasts present in the oil, considered to be opportunistic pathogens to man as they have often been isolated from immunocompromised hospital patients. Present research demonstrates the presence of dimorphic yeast forms in 26% of the commercial extra virgin olive oil originating from different geographical areas, where the dimorphic yeasts are represented by 3–99.5% of the total yeasts. The classified isolates belonged to the opportunistic pathogen species Candida parapsilosis and Candida guilliermondii, while among the dimorphic yeasts considered not pathogenic to man, the Candida diddensiae species was highlighted for the first time in olive oil. The majority of the studied yeast strains resulted lipase positive, and can consequently negatively influence the oil quality through the hydrolysis of the triglycerides. Furthermore, all the strains showed a high level of affinity with some organic solvents and a differing production of biofilm in “vitro” corresponded to a greater or lesser hydrophobia of their cells. Laboratory trials indicated that the dimorphic yeasts studied are sensitive towards some components of the oil among which oleic acid, linoleic acid and triolein, whereas a less inhibiting effect was observed with tricaprilin or when the total polyphenols extracted from the oil were used. The observations carried out on a scanning electron microscope (SEM), demonstrated the production of long un-branched pseudohyphae in all the tested dimorphic yeasts when cultivated on nutrient-deficient substrates.     

2014年中国大陆食源性疾病暴发事件监测资料分析

目的 分析2014年中国大陆食源性疾病暴发监测事件的致病因素、原因食品、发生场所和引发因素。方法 对全国食源性疾病暴发监测网收集的2014年食源性疾病暴发监测数据进行统计分析。结果 2014年,全国31个监测地区共上报食源性疾病暴发事件1 480起,累计发病17 651人,死亡111人。已知原因事件中,微生物性因素引起的事件起数和发病人数最多,分别占38.0%(437/1 151)和58.1%(8 181/14 093);毒蘑菇导致的死亡人数最多,占56.5%(61/108);已明确的原因食品(除误食毒蘑菇外)中,主要为肉类和蔬菜类食品,其事件起数分别占14.7%(186/1 265)和13.5%(171/1 265)。发生场所主要为餐饮服务场所,事件起数和发病人数分别占总数的37.1%(549/1 480)和51.0%(9 008/17 651)。引发因素明确的事件中,主要引发因素为误食误用和对食品的加工不当,事件起数分别占31.1%(348/1 118)和27.3%(305/1 118)。结论 微生物性食源性疾病是不容忽视的重要食品安全问题,家庭误食毒蘑菇是造成死亡的主要因素,宾馆饭店和集体食堂等餐饮服务场所对食品加工不当是引起暴发的常见原因,误食误用是食源性疾病暴发的高危因素。