An outbreak of Aspergillus species in response to environmental conditions in Serbia

Abstract

SUMMARYThe frequency and incidence of A. flavus and A. niger on barley, maize, soybean, sunflower and wheat grain, the abundance of European corn borer (Ostrinia nubilalis) moths and their interaction depending on weather conditions in the 2008-2012 period were studied. Under the agroecological conditions of Serbia, the species A. niger is more frequent than A. flavus, and concerning the crop species, its frequency is highest in kernels of sunflower, than soybean, maize, barley and wheat. A. flavus was extremely dominant on all plant species in 2012 regarding its frequency: 100% on soybean, 95.3% on maize, 65.2% on barley, 57.1% on sunflower and 45.8% on wheat. Furthermore, the incidence of A. flavus was higher in 2012 than in previous years. The uncommonly high frequency and incidence of A. flavus infestation of maize grain in 2012 were caused by extremely stressful agrometeorological conditions, high temperatures and drought over the period from flowering to waxy maturity of maize. The precipitation factor (Pf = precipitation sum / average monthly temperature) showed that 2012 was extremely arid in June (Pf = 0.57), July (Pf = 1.45), August (Pf = 0.15) and September (Pf = 1.42). European corn borer (ECB) was a second factor causing intensive occurrence of A. flavus on maize grain in 2012. The maximum flight of ECB moths was recorded as early as in July (5,149) and, as a result of this, high damage and numerous injuries were detected at harvest. Those injuries were covered by visible olive-green powdery colonies typical of A. flavus. In the chronology of A. flavus occurrence, these are the first data on its very high frequency and incidence under the agroecological conditions of Serbia. As intensive infections with A. flavus were rare in the past 50 years, the level of aflatoxins in maize grain was low.

Overview on the Mycotoxins Incidence in Serbia in the Period 2004–2016

“…in Serbia show low incidence frequency and low levels in grain in previous years. Over the period 1967–2008 the frequency varied from 1.0 to 23.1% [28]. This probably provides a rationale on why only a few studies of AFs occurrence were conducted in Serbia prior to 2012.…”

Impact of climate change on aflatoxin M1 contamination of raw milk with special focus on climate conditions in Serbia

“…According to a report by the Republic Hydrometeorological Service of Serbia, climate change resulted in specific extreme conditions in the period from 2011 to 2018, producing years with characteristics which had not occurred previously in Serbia. Prolonged periods of extremely high air temperatures during the summer of 2012 (daily temperatures near 40 °C) were associated with precipitation deficit and resulted in the highest average frequency of Aspergillus spp., particularly A. flavus (which is xerophilic) and Aspergillus niger , on analyzed grain (95.3%) . Consequently, several Rapid Alert System on Food and Feed (RASFF) notifications related to AF levels above the MPLs in maize from countries from South‐East Europe were issued at the end of 2012 and continued on in the first months of 2013 .…”

“…Considering that mycotoxins are climate‐dependent, preharvest (plant pathogenic) and storage‐associated (saprophytic fungi) problems, climate change and variability will lead to a slight shift from traditional occurrence areas for Aspergillus and Fusarium species to optimum climatic conditions they require for growth, distribution and mycotoxin production. As a result of the very hot and dry seasons during the last 15 years, Aspergillus flavus and related ‘higher‐temperature mycotoxins’ became a significant problem as the predominant toxigenic fungal infection of maize in several countries where this had previously been uncommon, including Serbia . Global temperature trends in the future predict continuous warming by up to +2 °C at mid‐century, which may result in further aflatoxin (AF) contamination of maize, resulting in high levels of aflatoxin M1 (AFM1) in the milk of animals fed this maize .…”

Effects of caraway and juniper essential oils on aflatoxigenic fungi growth and aflatoxins secretion in polenta

“…A. parasiticus CBS 260.67 was obtained from the Centralbureau voor Schimmelcultures (CBS, Utrecht, The Netherlands) (Table ). On the other hand, in our climate area, due to climate change, the presence of aflatoxigenic molds and aflatoxins in corn and other cereals has been sporadically in recent years (Kos et al, ; Lević et al, ). This was another reason for investigation of these strains.…”