Ugwuanyi Chinonso Celestina, Chidebelu Paul Ekene, Nweze Emeka Innocent
Department of Microbiology, University of Nigeria, Nsukka, Nigeria.
Mycotoxin Res. 2025 Aug;41(3):415-423. doi: 10.1007/s12550-025-00590-5. Epub 2025 May 7.
Several commodities have been frequently reported to be contaminated by aflatoxins, but little is known about aflatoxin accumulation in tobacco snuff frequently consumed globally, especially in Nigeria. Ascertaining their aflatoxin content and by extension, the health implications on those who use these tobacco products are necessary. Snuff samples from 30 vendors in six randomly selected markets were screened for Aspergillus spp. DNA sequencing was used for molecular identification of isolated Aspergillus flavus by amplifying the ITS region of ribosomal DNA using ITS1 and ITS4 primers. The isolates were screened for aflatoxin biosynthesis genes such as ver-1, nor-1 and omt-1 genes. Aflatoxin production potentials of the isolates were analyzed using maize kernels and quantified using thin layer chromatography (TLC) technique. The tobacco snuff samples were also analyzed to detect aflatoxins and their accumulation. Forty-two Aspergillus species were recovered and identified. Aspergillus niger (24) was the most common species with an occurrence rate of 57%, followed by Aspergillus fumigatus (13), at 31% occurrence, while only five (12%) Aspergillus flavus were recovered. Out of the three selected genes screened, nor-1 gene was confirmed to be present in the five isolates, whereas ver-1 and omt-1 genes were absent. Aflatoxin B (AFB) and aflatoxin B (AFB) were detected in both snuff and maize samples, while aflatoxin G (AFG) and aflatoxin G (AFG) were absent in all samples. This study confirms that most snuff sold in markets are contaminated with toxigenic fungi. Proper production procedure and enhancement in the sanitary standards of markets and vendors will help reduce contaminations.
几种商品经常被报道受到黄曲霉毒素污染，但对于全球频繁消费的鼻烟中黄曲霉毒素的积累情况知之甚少，尤其是在尼日利亚。确定其黄曲霉毒素含量以及由此推断对使用这些烟草产品的人的健康影响是必要的。对从六个随机选择的市场的30个供应商处采集的鼻烟样品进行了曲霉菌属筛查。通过使用ITS1和ITS4引物扩增核糖体DNA的ITS区域，采用DNA测序对分离出的黄曲霉进行分子鉴定。对分离株进行黄曲霉毒素生物合成基因如ver-1、nor-1和omt-1基因的筛查。使用玉米粒分析分离株产生黄曲霉毒素的潜力，并采用薄层色谱（TLC）技术进行定量。还对鼻烟样品进行分析以检测黄曲霉毒素及其积累情况。共回收并鉴定出42种曲霉菌。黑曲霉（24种）是最常见的菌种，出现率为57%，其次是烟曲霉（13种），出现率为31%，而仅回收了5种（12%）黄曲霉。在所筛查的三个选定基因中，证实五个分离株中存在nor-1基因，而ver-1和omt-1基因不存在。在鼻烟和玉米样品中均检测到黄曲霉毒素B（AFB）和黄曲霉毒素B（AFB），而所有样品中均未检测到黄曲霉毒素G（AFG）和黄曲霉毒素G（AFG）。本研究证实，市场上销售的大多数鼻烟都受到产毒真菌的污染。适当的生产程序以及提高市场和供应商的卫生标准将有助于减少污染。
