Co-occurrence of mycotoxins in stored maize from southern and southwestern Ethiopia.

Maize grain samples collected from 129 small-scale farmers' stores in southern and southwestern Ethiopia were analysed by LC-MS/MS for a total of 218 mycotoxins and other fungal metabolites of which 15% were regulated mycotoxins. Mycotoxins produced by Penicillium, Aspergillus, and Fusarium accounted for 31%, 17%, and 12% of the metabolites, respectively. Most of the current samples were contaminated by masked and/or emerging mycotoxins with moniliformin being the most prevalent one, contaminating 93% of the samples. Each sample was co-contaminated by 3 to 114 mycotoxins/fungal metabolites. Zearalenone, fumonisin B1, and deoxynivalenol were the dominant mycotoxins, occurring in 78%, 61%, and 55% of the samples with mean concentrations of 243, 429, and 530 µg/kg, respectively. The widespread co-occurrence of several mycotoxins in the samples may pose serious health risks due to synergistic/additional effects.

Multiple mycotoxins associated with maize (Zea mays L.) grains harvested from subsistence farmers' fields in southwestern Ethiopia.

Fifty-four maize grain samples freshly harvested from subsistence farmers' fields in southwestern Ethiopia were analyzed for multiple mycotoxins using liquid chromatography-tandem mass spectrometric (LC-MS/MS) method following extraction by acetonitrile/water/acetic acid on a rotary shaker. The grain samples were contaminated with a total of 164 metabolites, of which Fusarium and Penicillium metabolites were the most prevalent accounting for 27 and 30%, respectively. All the major mycotoxins and derivatives except one (citrinin) were of Fusarium origin. Zearalenone was the most frequent major mycotoxin occurring in 74% of the samples at concentrations of 0.32-1310 µg/kg. It was followed by nivalenol (63%), zearalenone-sulfate (44%), and fumonisin B1 (41%). Nivalenol, nivalenol glucoside, and fusarenon-X were detected at unusually high levels of 8-1700 µg/kg, 21-184 µg/kg, and 33-149 µg/kg, respectively. Deoxynivalenol and DON-3 glucoside contaminated 32% of the samples, each at levels of 15.9-5140 µg/kg and 10-583 µg/kg, respectively. Moniliformin and W493B occurred in 96 and 22% samples at levels of 3.27-4410 µg/kg and 3-652 µg/kg, respectively. Fumonisins were also detected in the samples at levels of 9-6770 µg/kg (B1), 16-1830 µg/kg (B2), 9.5-808 µg/kg (B3), and 1.3-128 µg/kg (A1). This study confirmed the presence of an array of mycotoxins contaminating maize grains right from the field. The effect of the co-occurring mycotoxins on consumers' health should be investigated along with that of the newly emerging ones. Results of the current study call for application of pre-harvest mycotoxin mitigation strategies to safeguard maize-based food and feed.

Evaluation of sorghum genotypes and influence of weather variables on anthracnose (Colletotrichum sublineolum) disease development under field conditions at Jimma, southwestern Ethiopia.

The severity and temporal dynamics of sorghum anthracnose on six and nine sorghum genotypes were evaluated on field plots during 2014 and 2015 cropping years in Southwestern Ethiopia, respectively. Anthracnose severity was assessed as the proportion of leaf area affected by the disease. 12 consecutive time point anthracnose severity assessments and their mean severity, disease progress rate, AUDPC, grain yield and yield related components were used to evaluate the response of the genotypes. In the year 2014 and 2015, the mean anthracnose severity was varying from 65 to 79 PSI and 54-82 PSI among six and nine sorghum genotypes, respectively. AUDPC varied from 5063 to 6113%-day and 4171 to 6383%-day in the year 2014 and 2015, respectively. BRC-378 and BRC-245 genotypes consistently had the lowest disease levels and highest grain yields during the two experimental years. The disease pressure was reduced, whereas grain yield and 1000-seed weight of the genotypes were increased in 2015 cropping year. Anthracnose severity was strongly correlated with weather variables and showed strong negative associations with grain yield of all tested sorghum genotypes.

Genetic Diversity and Population Structure of Didymella rabiei Affecting Chickpea in Ethiopia.

Ascochyta blight, also known as chickpea blight, which is caused by the fungal pathogen, Didymella rabiei, is an important disease affecting chickpea (Cicer arietinum L.) in many countries. We studied the genetic diversity and population structure of 96 D. rabiei isolates collected from three geographic populations in Ethiopia using simple sequence repeat (SSR) markers. We confirmed the genetic identity of 89 of the D. rabiei isolates by sequencing their rRNA internal transcribed spacer region genes. The chickpea blight pathogen isolates were genetically diverse, with a total of 51 alleles identified across 6 polymorphic SSR loci, which varied from 3 to 18 (average 8.5) alleles per SSR marker. The observed heterozygosity and expected heterozygosity ranged from 0.01 to 0.92 and 0.19 to 0.86, respectively. The mean polymorphic information content value of the D. rabiei populations was 0.58, with a mean gene diversity of 0.61 among loci. Gene flow (Nm = number of migrants) for the three populations of D. rabiei isolates ranged from 1.51 to 24.10 (average 6.2) migrants/cluster. However, the genetic variation between the D. rabiei populations was small (8%), with most of the variation occurring within populations (92%). Principal component analysis to visualize genetic variation showed that the D. rabiei isolates obtained from most of the chickpea samples formed roughly three groups on a two-dimensional coordinate plane. Similarly, the clustering of individuals into populations based on multi-locus genotypes (using Clumpak) grouped isolates into three clusters but with individual isolate admixtures. Hence, no clear geographic origin-based structuring of populations could be identified. To our knowledge, this is the first report of D. rabiei diversity in Ethiopia. Virulence studies should be conducted to develop chickpea varieties that are resistant to more aggressive pathogen populations.

Household food insecurity and mental distress among pregnant women in Southwestern Ethiopia: a cross sectional study design.

BACKGROUND: There are compelling theoretical and empirical reasons that link household food insecurity to mental distress in the setting where both problems are common. However, little is known about their association during pregnancy in Ethiopia. METHODS: A cross-sectional study was conducted to examine the association of household food insecurity with mental distress during pregnancy. Six hundred and forty-two pregnant women were recruited from 11 health centers and one hospital. Probability proportional to size (PPS) and consecutive sampling techniques were employed to recruit study subjects until the desired sample size was obtained. The Self Reporting Questionnaire (SRQ-20) was used to measure mental distress and a 9-item Household Food Insecurity Access Scale was used to measure food security status. Descriptive and inferential statistics were computed accordingly. Multivariate logistic regression was used to estimate the effect of food insecurity on mental distress. RESULTS: Fifty eight of the respondents (9%) were moderately food insecure and 144 of the respondents (22.4%) had mental distress. Food insecurity was also associated with mental distress. Pregnant women living in food insecure households were 4 times more likely to have mental distress than their counterparts (COR = 3.77, 95% CI: 2.17, 6.55). After controlling for confounders, a multivariate logistic regression model supported a link between food insecurity and mental distress (AOR = 4.15, 95% CI: 1.67, 10.32). CONCLUSION: The study found a significant association between food insecurity and mental distress. However, the mechanism by which food insecurity is associated with mental distress is not clear. Further investigation is therefore needed to understand either how food insecurity during pregnancy leads to mental distress or weather mental distress is a contributing factor in the development of food insecurity.

Isolation and characterisation of Ralstonia solanacearum strains from Solanaceae crops in Ethiopia.

Eighty one isolates of Ralstonia solanacearum -like bacteria on triphenyl tetrazolium chloride (TTC) medium were collected from different Solanaceae crops (i.e. potato, tomato and pepper plants and potato tubers) at various sites in Ethiopia. Of these, 62 strains were identified as R. solanacearum based on their cultural characteristics on TTC medium, tomato pathogenicity bioassay, carbon source utilisation patterns and a specific PCR-based assay. By Hayward's classification method, based on carbon source utilisation, 19 of the 62 R. solanacearum strains were identified as biovar I and 43 strains were identified as biovar II. The biovar I strains exhibited a high growth rate at high temperatures (37 degrees C). Whereas the growth rate of biovar II strains was greatest at lower temperatures (22 degrees C). Biovar I strains had broader host range than biovar II strains, which were limited to potato, tomato, and eggplant. To our knowledge, this is the first report of R. solanacearum biovar I in Ethiopia. The existence of biovar I strains in Ethiopia raises concerns because they have a broader host range than biovar II strains.