Toxigenic Species Aspergillus parasiticus Originating from Maize Kernels Grown in Serbia

In Serbia, aspergillus ear rot caused by the disease pathogen Aspergillus parasiticus (A. parasiticus) was first detected in 2012 under both field and storage conditions. Global climate shifts, primarily warming, favour the contamination of maize with aflatoxins in temperate climates, including Serbia. A five-year study (2012–2016) comprising of 46 A. parasiticus strains isolated from maize kernels was performed to observe the morphological, molecular, pathogenic, and toxigenic traits of this pathogen. The HPLC method was applied to evaluate mycotoxin concentrations in this causal agent. The A. parasiticus isolates synthesised mainly aflatoxin AFB1 (84.78%). The percentage of isolates synthesising aflatoxin AFG1 (15.22%) was considerably lower. Furthermore, the concentration of AFG1 was higher than that of AFB1 in eight isolates. The polyphase approach, used to characterise isolates, showed that they were A. parasiticus species. This identification was verified by the multiplex RLFP-PCR detection method with the use of restriction enzymes. These results form an excellent baseline for further studies with the aim of application in the production, processing, and storage of cereal grains and seeds, and in technological processes to ensure the safe production of food and feed.     

Distribution of Aspergillus Fungi and Recent Aflatoxin Reports,Health Risks,and Advances in Developments of Biological Mitigation Strategies in China

Aflatoxins (AFs) are secondary metabolites that represent serious threats to human and animal health. They are mainly produced by strains of the saprophytic fungus Aspergillus flavus, which are abundantly distributed across agricultural commodities. AF contamination is receiving increasing attention by researchers, food producers, and policy makers in China, and several interesting review papers have been published, that mainly focused on occurrences of AFs in agricultural commodities in China. The goal of this review is to provide a wider scale and up-to-date overview of AF occurrences in different agricultural products and of the distribution of A. flavus across different food and feed categories and in Chinese traditional herbal medicines in China, for the period 2000–2020. We also highlight the health impacts of chronic dietary AF exposure, the recent advances in biological AF mitigation strategies in China, and recent Chinese AF standards.     

真菌霉素诱发的小鼠肺腺癌组织发生的研究

目的　探讨真菌毒素诱发的NIH小鼠肺腺癌组织学来源及其可能致癌机理。方法　采用34例长期灌胃黄曲霉毒素G1(AFG1)和杂色曲霉素(ST)诱发的NIH小鼠实验性肺腺癌组织作为研究对象,同时以12例正常肺组织作为对照。采用免疫组化染色方法以肺Ⅱ型肺泡上皮细胞特异分化标志物SP C和Clara细胞特定分化标志物CC 10的表达情况确定肺腺癌的组织来源。同时以免疫组化方法分析本组实验性肺腺癌P5 3、Ras和PCNA的表达情况。结果　全部34例肺腺癌癌细胞均可见肺Ⅱ型肺泡上皮细胞特异分化标志物SP C蛋白的阳性表达,阳性表达率为10 .0 % ,而Clara细胞特定分化标志物CC 10均为阴性表达(P <0 .0 1)。肺腺癌细胞PCNA平均阳性标记指数为73 .32 % ,明显高于对照组2 2 . 4 3% (P <0 . 0 1) ,但肺腺癌细胞未见突变型抑癌基因P5 3和癌基因RasP2 1在蛋白水平上的表达。结论　真菌毒素诱发的实验动物肺腺癌组织来源于Ⅱ型肺泡上皮细胞,具有较高的增殖活性,但未见突变型P5 3和RasP2 1在蛋白水平的表达。     

淡豆豉炮制过程中不产毒黄曲霉菌的分布特征及其对产毒菌的拮抗作用

目的 明确淡豆豉Sojae Semen Praeparatum炮制中不产毒黄曲霉菌Aspergillus flavus的分布特征及其拮抗能力。方法 按实验室前期已建立的规范炮制工艺制备淡豆豉,获取淡豆豉炮制中9个不同时间点的样本,各样本用氯硝胺18%甘油培养基（DG-18）进行培养、分离纯化,经形态学初筛、分子生物学鉴定为黄曲霉菌。通过紫外荧光法初筛和超高效液相色谱-串联质谱法（ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS）测定黄曲霉菌产毒能力,确定为不产毒黄曲霉菌（简称：不产毒菌）。用平板对峙法检测不产毒菌及其代谢产物对产毒黄曲霉菌标准株（产毒菌）生长的影响。结果 从淡豆豉炮制过程中共筛选出21株不产毒菌,其中“黄衣上遍”过程中的第3、6天分别筛选出3、6株,“再闷”过程中的第3、6、9天分别筛选出2、7、3株,再闷第6天筛选到的不产毒菌最多。不产毒菌对产毒菌的生长抑制率在26.75%～36.69%,抑制效果最好的是F6-L8（指第1批在“黄衣上遍”阶段的发酵第6天样品中筛选到的...     

穿梭质粒pSP189/哺乳动物细胞系统在AFB_1诱变分子机理研究中的应用

ＡｆｌａｔｏｘｉｎＢ１（ＡＦＢ１）是食品中广泛存在的致癌性最强的霉菌毒素之一，本文将基于ＳＶ４０病毒的短暂复制型穿梭质粒ｐＳＰ１８９与非洲绿猴肾细胞（ＶｅｒｏＥ６细胞系）组成穿梭质粒／哺乳动物细胞诱变检测系统检测ＡＦＢ１的诱变性，并通过对靶基因ＳｕｐＦＴＲＮＡ的序列分析了解ＡＦＢ１在ＤＮＡ一级结构上的作用位点，类型及序列特异性等信息。结果表明：在体外采用大鼠肝微粒体与ＡＦＢ１和ｐＳＰ１８９直接作用形成ＡＦＢ１－ＤＮＡ加合物，再转染ＶｅｒｏＥ６细胞，随着ＡＦＢ１作用质粒ＤＮＡ时间的延长，经哺乳动物细胞内复制并在宿主菌中筛选得到的突变体逐渐增加，并呈明显的剂量－反应关系，检出的突变体经０．８％琼脂糖凝胶电泳分析大多为点突变，对其中５３个独立突变子的靶基因ＳｕｐＦＴＲＮＡ的序列分析结果表明：ＡＦＢ１诱发ｐＳＰ１８９靶基因ＳｕｐＴＩＲＮＡ的突变大多单碱基置换，占突变子总数的８４．９％，９５．２％的碱基置换发生在ＧＣ位点，其中以ＧＣ→ＴＡ的颠换占大多数，约为５３．３％，其次为ＧＣ→ＡＴ的转换，约为３５．６％；ＡＦＢ１诱发的突变在靶基因ＳｕｐＦＴＲＮＡ的分布并非是随机的，而是存在着一定的序列特异性，其特征序列为“５＇－?     

Ultrastructure of the Chlamydospore Growth Phase of Aspergillus parasiticus Associated with Higher Production of Aflatoxins

Summary: The ultrastructure of the chlamydospore growth phase of Aspergillus parasiticus associated with higher production of aflatoxin is fully described. The growth was obtained by growing the fungus on a synthetic liquid medium for 72 hours at 28° C under constant shaking.
Zusammenfassung: Die Ultrastruktur der Chlamydosporen-Wachstumsphase von Aspergillus parasiticus, die mit höherer Produktion von Aflatoxin einhergeht, wird beschrieben. Diese Wuchsform war durch Züchtung des Pilzes auf einem synthetischen flüssigen Nährboden für 72 Stunden bei 28°C unter ständigem Schütteln erzeugt worden.     

Risk of dietary and breastmilk exposure to mycotoxins among lactating women and infants 2–4 months in northern India

Mycotoxins are carcinogenic secondary metabolites of fungi that have been linked to infant growth faltering. In this study, we quantified co‐occurring mycotoxins in breast milk and food samples from Haryana, India, and characterized determinants of exposure. Deterministic risk assessment was conducted for mothers and infants. We examined levels of eight mycotoxins (Aflatoxin B₁, B₂, G₁, G₂, M₁, M₂; Ochratoxin A, B) in 100 breast milk samples (infants 2–4 months) using ultra‐high‐performance liquid chromatography tandem mass spectrometry. Aflatoxin B₁ (AFB₁), fumonisin B₁ (FB₁) and deoxynivalenol (DON) were detected in several food items (n = 298) using enzyme‐linked immunosorbent assays. We report novel data on the presence of mycotoxins in breast milk samples from India. Whereas breast milk concentrations (AFM₁ median: 13.7; range: 3.9–1200 ng/L) remain low, AFM₁ was detected above regulatory limits in 27% of animal milk samples. Additionally, 41% of infants were above provisional maximum tolerable daily intake (PMTDI) limits for AFM₁ due to consumption of breast milk (mean: 3.04, range: 0.26–80.7 ng kg⁻¹ bw day⁻¹). Maternal consumption of breads (p < 0.05) was associated with breast milk AFM₁ exposure. AFB₁ (μg/kg) was detected in dried red chilies (15.7; 0–302.3), flour (3.13; 0–214.9), groundnuts (0; 0–249.1), maize (56.0; 0–836.7), pearl millet (1.85; 0–160.2), rice (0; 0–195.6), wheat (1.9; 0–196.0) and sorghum (0; 0–63.5). FB₁ (mg/kg) was detected in maize (0; 0–61.4), pearl millet (0; 0–35.4) and sorghum (0.95; 0–33.2). DON was not detected in food samples. Mothers in our study exceeded PMTDI recommendations for AFB₁ due to consumption of rice and flour (mean: 75.81; range: 35.2–318.2 ng kg⁻¹ bw day⁻¹). Our findings show the presence of Aflatoxin B₁ and M₁ at various levels of the food chain and in breast milk, with estimated intakes exceeding PMTDI recommendations. Aflatoxins are known carcinogens and have also been linked to stunting in children. Their presence across the food system and in breast milk is concerning, thus warranting further research to replicate and expand on our findings and to understand implications for maternal and child health.     

Determination of aflatoxin and fumonisin levels through ELISA and HPLC,on tilapia feed in Nayarit,Mexico

A survey of fungal contamination and presence of aflatoxins (AFs) and fumonisins (FBs) in 30 feed samples collected from 10 tilapia farms during three seasons in Nayarit State, located in north-western Mexico, was carried out using ELISA as screening and High-Performance Liquid Chromatography (HPLC) as confirmatory method. Mycobiota included Aspergillus flavus and Fusarium spp. AFs were detected in 63.3% of samples using ELISA, but confirmation by HPLC revealed that all samples were under the detection limit. Regarding to FBs, positive samples were detected using both methods, with 19 positive samples (60% of total) by ELISA and 14 positive samples (46.6% of total) by HPLC and levels ranging from 0.148 to 2.587 mg/kg. Correlation was observed between both methods (r = 0.516, p = 0.004) for FBs results. No sample exceeded the European maximum levels for any of the mycotoxins. Water activity of samples ranged from 0.345 to 0.655, suggesting that mycotoxin occurrence is probably related to raw material contamination.     

稀释法结合LC-MS/MS检测在10种中药材污染黄曲霉毒素高通量筛查中的应用研究

该研究运用稀释法,克服了基质效应对10种中药材污染黄曲霉毒素B₁,B₂,G₁,G₂的液质联用检测的影响,高、中、低3个浓度水平的基质效应检测结果在80.23%~115.5%,符合准确定量的要求。为增强检测结果的特异性和准确性,研究结合保留时间窗、定量离子与定性离子的峰面积比值2个指标对83批中药材的检测进行色谱峰的辨认,并以苦杏仁为基质溶液配制的3个浓度的质控样品对检测体系的稳定性进行考察。检测结果显示医院和药店的药材污染率分别为13.89%和17.02%,其中以使君子和红枣的污染率较高。质控样品的RSD<6.6%,表明该分析方法可用于这10种中药材的高通量的筛查和检测,具有经济、快速的优点。     

检测黄曲霉毒素生物合成相关基因芯片的研制

目的 建立比较成熟的可用于分析黄曲霉毒素生物合成相关基因的芯片技术.方法 采用反转录PCR和芯片检测对比的方法.实验所用探针来源于寄生曲霉,待测样品选择黄曲霉菌株.结果 芯片点阵后依次通过温浴2 h,650 mJ/cm<'2>紫外交联30 S,80℃烘烤2 h,预杂交45 min,清洗,干燥等步骤,最后与待测样品在42℃杂交16 h,获得了低背景高质量的芯片.芯片扫描显示荧光信号稳定,与反转录PCR扩增结果一致,并且无背景干扰.结论 探针设计合理,实验方法可靠.初步建立了用芯片检测与黄曲霉毒素生物合成相关基因的技术平台.