Encephalitozoon cuniculi in Raw Cow's Milk Remains Infectious After Pasteurization

Abstract

This study describes the prevalence of Encephalitozoon cuniculi in raw cow's milk and evaluates the effect of different milk pasteurization treatments on E. cuniculi infectivity for severe combined immunodeficient (SCID) mice. Using a nested polymerase chain reaction approach, 1 of 50 milking cows was found to repeatedly shed E. cuniculi in its feces and milk. Under experimental conditions, E. cuniculi spores in milk remained infective for SCID mice following pasteurization treatments at 72 °C for 15 s or 85 °C for 5 s. Based on these findings, pasteurized cow's milk should be considered a potential source of E. cuniculi infection in humans.

A multidisciplinary review about Encephalitozoon cuniculi in a One Health perspective

“…2 ). Moreover, it is assumed that microsporidia can be transmitted to humans through food, such as milk (Kváč et al 2016 ), fermented meat products (Sak et al 2019 ), and products from crops (Thurston-Enriquez et al 2002 ).

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“…Kváč et al ( 2016 ) reported for the first time the presence of E. cuniculi in cow’s milk and showed that its spores remain infective even after a high-temperature short-time (HTST) pasteurization process (72 °C for 15 s or 85 °C for 5 s). Moreover, Sak et al ( 2019 ) recently suggested that fermented pork products may represent an additional possible source of infection, considering the results of their study that show the presence of spores in pork meat samples, using a nested PCR protocol, and that the fermentation process is not effective for spore inactivation, under experimental conditions.…”

“…Previous serological studies showed a percentage of seropositivity of 67.7% in goats (Abu-Akkada et al 2015a ), 52.2% in swine (Malčeková et al 2010 ), 46.4% in buffaloes (Abu-Akkada et al 2015a ), 2.4–28.1% in cattle (Malčeková et al 2010 ; Abu-Akkada et al 2015a ), and 8.6–13.6% in sheep (Halánová et al 2003 ; Malčeková et al 2010 ; Abu-Akkada et al 2015a ). E. cuniculi was also identified in urine and fecal samples of cattle (Abu-Akkada et al 2015a ; Kváč et al 2016 ) and swine (Reetz et al 2009 ; Sak et al 2019 ), through molecular surveys. According to Kvapil et al ( 2021 ), herbivores seem to be more likely to become infected with E. cuniculi than carnivores and omnivores.…”

Are molecular tools clarifying or confusing our understanding of the public health threat from zoonotic enteric protozoa in wildlife?

“…Most human infections are thought to result from faecal-oral transmission of spores. Encephalitozoon spores have been detected in various water sources (irrigation water, recreational water, drinking water, and wastewater) and food (Dowd et al, 1998; Fournier et al, 2000; Decraene et al, 2012; Kváč et al, 2016). In addition, spores can be aerosolized from disturbed excrement and could be inhaled by hosts as airborne particles (Graczyk et al, 2008).…”