Soto Beltran Marcela, Gerba Charles P, Porto Fett Anna, Luchansky John B, Chaidez Cristobal
a Department of Soil, Water and Environmental Science , University of Arizona , Tucson , AZ , USA.
Int J Environ Health Res. 2015;25(2):140-8. doi: 10.1080/09603123.2014.915016. Epub 2014 May 8.
Queso fresco (QF) is a handmade cheese consumed and produced in Latin America. In Mexico, QF production is associated with a microbiological risk. The aim of the study was to determine the incidence and characterization of Listeria monocytogenes, Salmonella spp., and Shiga toxin-producing Escherichia coli (STEC) in QF from retail markets of the north-western State of Sinaloa, Mexico, and to assess the effect of physicochemical parameters on Listeria presence. A total of 75 QF samples were obtained. L. monocytogenes, E. coli, and coliforms were detected in 9.3, 94, and 100%, respectively. Salmonella was not detected. STEC isolates showed virulence genes. Microbial loads were above the maximum values recommended by the Official Mexican Standards. Physicochemical parameters such as water activity (aw), moisture content, pH, and salinity played a role in Listeria prevalence in QF. Rigorous control in QF made in Culiacan, Mexico is needed to reduce the risk of foodborne pathogens.
新鲜奶酪（QF）是一种在拉丁美洲消费和生产的手工奶酪。在墨西哥，新鲜奶酪的生产存在微生物风险。本研究的目的是确定墨西哥锡那罗亚州西北部零售市场的新鲜奶酪中单核细胞增生李斯特菌、沙门氏菌和产志贺毒素大肠杆菌（STEC）的发生率和特征，并评估理化参数对李斯特菌存在的影响。共采集了75份新鲜奶酪样本。分别在9.3%、94%和100%的样本中检测到单核细胞增生李斯特菌、大肠杆菌和大肠菌群。未检测到沙门氏菌。产志贺毒素大肠杆菌分离株显示出毒力基因。微生物负荷高于墨西哥官方标准推荐的最大值。水分活度（aw）、水分含量、pH值和盐度等理化参数在新鲜奶酪中李斯特菌的流行中起作用。需要对墨西哥库利亚坎生产的新鲜奶酪进行严格控制，以降低食源性病原体的风险。
