da Cruz Cabral Lucía, Rodriguero Marcela, Stenglein Sebastián, Fog Nielsen Kristian, Patriarca Andrea
Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Laboratorio de Microbiología de Alimentos, Buenos Aires, Argentina.
Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA - CONICET/UBA), Grupos de Investigación en Filogeografía y Filogenias Moleculares, Buenos Aires, Argentina.
Int J Food Microbiol. 2017 Sep 18;257:206-215. doi: 10.1016/j.ijfoodmicro.2017.06.026. Epub 2017 Jun 27.
Small-spored Alternaria have been isolated from a wide variety of food crops, causing both economic losses and human health risk due to the metabolites produced. Their taxonomy has been discussed widely, but no scientific consensus has been established in this field to date. Argentina is a major exporter of agricultural products, so it is essential to thoroughly understand the physiological behaviour of this pathogen in a food safety context. Thus, the objective of this work was to characterize small-spored Alternaria spp. obtained from tomato fruits, pepper fruits, wheat grains and blueberries from Argentina by a polyphasic approach involving metabolomic and phylogenetic analyses based on molecular and morphological characters. Morphological analysis divided the population studied into three groups; A. arborescens sp.-grp., A. tenuissima sp.-grp., and A. alternata sp.-grp. However, when these characters were simultaneously analysed with molecular data, no clearly separated groups were obtained. Haplotype network and phylogenetic analysis (both Bayesian and maximum parsimony) of a conserved region yielded the same result, suggesting that all isolates belong to the same species. Furthermore, no correlation could be established between morphological species-groups and a metabolite or group of metabolites synthesized. Thus, the whole set of analyses carried out in the present work supports the hypothesis that these small-spored Alternaria isolates from food belong to the same species. Identification at species level through classical morphology or modern molecular techniques does not seem to be a useful tool to predict toxicological risk in food matrices. The detection of any small-spored Alternaria from Section Alternaria (D.P. Lawr., Gannibal, Peever & B.M. Pryor 2013) in food implies a potential toxicological risk.
小孢子链格孢已从多种粮食作物中分离出来，由于其产生的代谢产物，会造成经济损失并带来人类健康风险。其分类学已得到广泛讨论，但迄今为止该领域尚未达成科学共识。阿根廷是主要农产品出口国，因此在食品安全背景下全面了解这种病原体的生理行为至关重要。因此，本研究的目的是通过一种多相方法对从阿根廷的番茄果实、辣椒果实、小麦籽粒和蓝莓中分离得到的小孢子链格孢进行特征描述，该方法包括基于分子和形态特征的代谢组学和系统发育分析。形态学分析将所研究的群体分为三组；即树木链格孢种组、细极链格孢种组和链格孢种组。然而，当将这些特征与分子数据同时分析时，并未得到明显分开的组。对一个保守区域的单倍型网络和系统发育分析（贝叶斯分析和最大简约法）得出了相同的结果，表明所有分离株都属于同一物种。此外，形态学物种组与合成的一种代谢物或一组代谢物之间无法建立相关性。因此，本研究中进行的所有分析都支持这样的假设，即这些从食物中分离得到的小孢子链格孢分离株属于同一物种。通过经典形态学或现代分子技术在物种水平上进行鉴定似乎并不是预测食品基质中毒理学风险的有用工具。在食品中检测到链格孢组（D.P. Lawr.、Gannibal、Peever & B.M. Pryor 2013）中的任何小孢子链格孢都意味着潜在的毒理学风险。
