Production of citreoviridin byPenicillium citreonigrumstrains associated with rice consumption and beriberi cases in the Maranhão State, Brazil

Abstract

The aim of this study was to determine the levels of Penicillium citreonigrum and citreoviridin present in rice samples from Maranhão State, Brazil, where an outbreak of beriberi was reported and 32 deaths occurred (7% of the notified cases died in 2006). The ability of P. citreonigrum to produce citreoviridin was assessed, and a total of 420 samples of 21 different kinds of rice were collected. Mycobiota isolation and identification, the ability of citreoviridin strains to produce toxin, and the natural occurrence of citreoviridin were established. Rice samples were found to have high fungal counts and showed increasing levels from 2004 to 2007 harvest years. The most frequent genus was Aspergillus followed by Penicillium and Cladosporium. Ten out of eleven strains of P. citreonigrum were able to produce citreoviridin. Three rice samples had levels of citreoviridin ranging from 12 to 96.7 ng g(-1), and two bran samples had levels of 128 and 254 ng g(-1). These samples contaminated with P. citreonigrum and citreoviridin were involved in the beriberi cases from Maranhão State. Monitoring rice for mycotoxins in areas where this substrate is the basic food is crucial to prevent outbreaks like the one reported in this study, to improve management practice, and to diminish exposure risk of humans to these harmful toxins.

Outbreak of Beriberi among African Union Troops in Mogadishu, Somalia

“…Elimination of beriberi in Japan was attributed to improvements in rice quality. Recent investigations of cases of beriberi in Brazil have supported a link to rice, and led to additional calls for improving rice quality [18], but the role of citreoviridin in these cases is disputed [19]. In Mogadishu, we did not note any discoloration of the stored rice, although we did not evaluate fungal colonization of rice samples.…”

Occurrence of Penicillium brocae and Penicillium citreonigrum, which Produce a Mutagenic Metabolite and a Mycotoxin Citreoviridin, Respectively, in Selected Commercially Available Rice Grains in Thailand

“…As beriberi disease did not occur in Japan after World War II, this yellowed rice toxic syndrome was largely forgotten. However, in 2006 to 2008, an outbreak occurred in Brazil due to the consumption of CTV-contaminated rice [18]. This incident reminded us of past issues associated with yellowed rice in Japan.…”

“…As these two Penicillium species are not common air-borne fungi, our untreated approach seems to have been useful for the isolation of uncommon Penicillium species, possibly due to their susceptibility to the disinfecting agents compared with the common field or storage fungi of Aspergillus , Bipolaris , Colletotrichum , Curvularia , Mucor , Phoma , and Rhizopus [19]. This may explain why previous studies on mycoflora in rice failed to find any P. citreonigrum or P. brocae , except in the case of the P. citreonigrum responsible for food poisoning in Brazil [18]. …”

Purification and full characterisation of citreoviridin produced byPenicillium citreonigrumin yeast extract sucrose (YES) medium

“…In May 2006, an outbreak of beriberi was reported in the state of Maranhão, Brazil, and by 2008, 1207 cases of the disease were reported, with 40 deaths (Padilha et al 2011). Rice samples collected in the outbreak region were highly infested with many fungal species, including P. citreonigrum, with some samples being positive for citreoviridin (Rosa et al 2010). Cases of beriberi are still being reported in the region, but its association with the consumption of rice contaminated with citreoviridin is not yet clear (Alves et al 2010).…”