ABSTRACT
AIMS: Alternaria alternata is a major contaminant of wine grapes, meaning a health risk for wine consumers due to the accumulation of toxic metabolites. To develop a successful biofungicide, the effectiveness of epiphytic wine grape yeasts against A. alternata growth and toxin production was assessed in vitro under temperature and aW conditions that simulate those present in the field. METHODS AND RESULTS: The effect of 14 antagonistic yeasts was evaluated on growth and alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) production by three A. alternata strains in a synthetic medium with composition similar to grape (SN) at three temperatures (15, 25 and 30°C). All Metschnikowia sp. yeast strains evaluated completely prevented A. alternata growth and mycotoxin production at all temperatures in SN medium. Meanwhile, the growth inhibition exerted by Starmerella bacillaris yeast strains was higher at 30°C, followed by 25 and 15°C, being able to show a stimulating or inhibiting effect. Hanseniaspora uvarum yeast strains showed a growth promoting activity higher at 15°C, followed by 25 and 30°C. Even at conditions where A. alternata growth was stimulated by the S. bacillaris and H. uvarum yeasts, high inhibitions of mycotoxin production (AOH, AME and TA) were observed, indicating a complex interaction between growth and mycotoxin production. CONCLUSION: There is a significant influence of temperature on the effectiveness of biocontrol against A. alternata growth and mycotoxin production. Metschnikowia sp. strains are good candidates to compose a biofungicide against A. alternata. SIGNIFICANCE AND IMPACT OF THE STUDY: Among the different antagonistic yeasts evaluated, only Metschnikowia sp. strains were equally effective reducing A. alternata growth and mycotoxin at different temperatures underlining the importance of considering environmental factors in the selection of the antagonists.
Subject(s)
Antibiosis , Mycotoxins , Vitis , Yeasts/physiology , Alternaria/pathogenicity , Fruit/microbiology , Hanseniaspora , Lactones/analysis , Mycotoxins/analysis , Saccharomycetales , Vitis/microbiology , WineABSTRACT
Abstract Mycotoxins are secondary metabolites produced by fungal species that mainly belong to Aspergillus, Fusarium, Penicillium and Alternaria, which can grow in a variety of crops including cereals, oilseeds and fruits. Consequently, their prevalence in foods and by-products not only affects human and animal health but also causes important losses in both domestic and international markets. This review provides data about toxigenic fungal species and mycotoxin occurrence in different crops commonly grown in Argentina. This information will be relevant to establish adequate management strategies to reduce the impact of mycotoxins on human food and animal feed chains and to implement future legislation on the maximum permitted levels of these fungal metabolites.
Resumen Las micotoxinas son metabolitos secundarios producidos por diferentes especies fúngicas pertenecientes, principalmente, a los géneros Aspergillus, Fusarium, Penicillium y Alternaria. Dichos microorganismos pueden crecer en una gran variedad de cultivos, entre los que se incluyen cereales, oleaginosas y frutas. La presencia de micotoxinas en alimentos y subproductos no sólo afecta la salud humana y animal, sino que también causa pérdidas importantes en los mercados nacionales e internacionales. Esta revisión proporciona datos sobre la prevalencia de especies fúngicas toxigénicas y de micotoxinas en diferentes cultivos y productos cosechados en Argentina. Dicha información será relevante para establecer estrategias de manejo adecuadas para reducir la entrada de las micotoxinas en las cadenas alimentarias del hombre y de los animales, así como para establecer futuras legislaciones sobre los niveles máximos permitidos de dichos metabolitos.
Subject(s)
Animals , Humans , Fusarium , Mycotoxins , Argentina , Food Contamination/analysis , FungiABSTRACT
We studied the epidemiologic triad-related factors influencing human papilloma virus (HPV) persistence in Mexican women with systemic lupus erythematosus (SLE). Patients aged ≥18 years with SLE (American College of Rheumatology criteria), with and without HPV persistence, were selected. Groups were analyzed by (1) host: clinical disease characteristics; (2) agent: (I) infectious (prevalence, incidence, HPV genotype and co-infections (≥2 HPV genotypes or mycoplasmas)), (II) chemical (contraceptives and immunosuppressive drugs) and (III) physical (vitamin D deficiency) and (3) environment. A total of 121 SLE patients were selected over a two-year period. (1) Host: mean age 45.8 years and disease duration 12.7 years. (2) Agent: (I) infectious. HPV infection prevalence in the second sample was 26.4%, high-risk HPV genotypes 21.5% and co-infections 7.4%. HPV infection incidence was 13.2%, persistence 13.2% and clearance 15.7%. (II) Chemical: use of oral hormonal contraceptives 5% and immunosuppressive treatment 97.5%. (III) Physical: Vitamin D levels were similar in both groups. (3) Environment: (I) natural. A total of 60.6% of patients were residents of Puebla City. (II) Social: The mean education level was 10.9. Poverty levels were: III degree 52.4%, IV degree 28% and II degree 17%. (III) Cultural behavioral: Onset of sexual life was 20.5 years, 10% had ≥3 sexual partners and 51.2% were postmenopausal. In conclusion, no factor of the epidemiologic triad was associated with HPV infection prevalence.
Subject(s)
Lupus Erythematosus, Systemic/complications , Lupus Erythematosus, Systemic/epidemiology , Papillomavirus Infections/epidemiology , Adult , Aged , Cohort Studies , Environment , Female , Humans , Mexico/epidemiology , Middle Aged , Papillomavirus Infections/complications , Papillomavirus Infections/virology , Young AdultABSTRACT
AIMS: To study the effects of water activity (aW ; 0·99, 0·98, 0·97, 0·96 and 0·95), temperature (15, 25 and 30°C), incubation time (7-28 days), and their interactions on mycelial growth and alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) mycotoxin production on a synthetic nutrient (SN) media similar to grape composition by three strains of Alternaria alternata isolated from wine grapes from Argentina. METHODS AND RESULTS: Interacting conditions of aW , temperature and time of incubation were used to examine growth and mycotoxin production. All strains were able to grow at 0·95 aW , but maximum growth rates were obtained at 0·99 aW and 25°C. Maximum levels of AOH, AME and TA were obtained at 0·99 aW and 25°C, but high amounts of TA were also obtained at 0·96 aW and 15 or 30°C. Production of AOH and AME was favoured over TA at 25°C. TA levels were more sustained than AOH and AME. CONCLUSION: The optimum and marginal conditions for growth and mycotoxin production by A. alternata on a SN media similar to grape composition were in agreement, but certain stressful conditions for growth evaluated also promote mycotoxin production. SIGNIFICANCE AND IMPACT OF THE STUDY: Temperature and aW conditions that allows growth and mycotoxin production are those normally found during wine grape ripeness in the field. Therefore, efforts should be made to prevent Alternaria presence and mycotoxin production in wine grapes.
Subject(s)
Alternaria/growth & development , Alternaria/metabolism , Mycotoxins/biosynthesis , Vitis/microbiology , Wine/microbiology , Argentina , Lactones/analysis , Temperature , Tenuazonic Acid/analysis , Water/chemistry , Wine/analysisABSTRACT
Dekkera/Brettanomyces bruxellensis is considered a major cause of wine spoilage, and 4-ethylphenol and 4-ethylguaiacol are the most abundant off-aromas produced by this species. They are produced by decarboxylation of the corresponding hydroxycinnamic acids (HCAs), followed by a reduction of the intermediate 4-vinylphenols. The aim of the present study was to examine coumarate decarboxylase (CD) and vinylphenol reductase (VR) enzyme activities in 5 native D. bruxellensis strains and determine their relation with the production of ethylphenols under 'wine-like' conditions. In addition, biomass, cell culturability, carbon source utilization and organic acids were monitored during 60 days. All strains assayed turned out to have both enzyme activities. No significant differences were found in CD activity, whilst VR activity was variable among the strains. Growth of D. bruxellensis under 'wine-like' conditions showed two growth phases. Sugars were completely consumed during the first growth phase. Transformation of HCAs into ethylphenols also occurred during active growth of the yeast. No statistical differences were observed in volatile phenol levels produced by the strains growing under 'wine-like' conditions, independently of the enzyme activity previously recorded. Furthermore, our results demonstrate a relationship between the physiological state of D. bruxellensis and its ability to produce ethylphenols. Inhibition of growth of D. bruxellensis in wine seems to be the most efficient way to avoid ethylphenol production and the consequent loss of wine quality.
Subject(s)
Carboxy-Lyases/metabolism , Dekkera/enzymology , Food Microbiology , Oxidoreductases/metabolism , Fermentation , Phenols/metabolism , Saccharomyces cerevisiae/metabolism , Wine/microbiologyABSTRACT
Fusarium proliferatum is a member of the Fusarium fujikuroi species complex (FFSC) involved in the maize ear rot together with Fusarium verticillioides, which is a very closely related species. Recently, different studies have detected natural fumonisin contamination in wheat kernels and most of them have shown that the main species isolated was F. proliferatum. Fusarium strains obtained from freshly harvested durum wheat samples (2008 to 2011 harvest seasons) from Argentina were characterized through a phylogenetic analysis based on translation elongation factor-1 alpha (EF-1α) and calmodulin (CaM) genes, determination of mating type alleles, and evaluation of fumonisin production capability. The strains were identified as F. proliferatum (72%), F. verticillioides (24%) and other Fusarium species. The ratio of mating type alleles (MAT-1 and MAT-2) obtained for both main populations suggests possible occurrence of sexual reproduction in the wheat fields, although this seems more frequent in F. proliferatum. Phylogenetic analysis revealed greater nucleotide variability in F. proliferatum strains than in F. verticillioides, however this was not related to origin, host or harvest year. The fumonisin-producing ability was detected in 92% of the strains isolated from durum wheat grains. These results indicate that F. proliferatum and F. verticillioides, among the fumonisin producing species, frequently contaminate durum wheat grains in Argentina, presenting a high risk for human and animal health.
Subject(s)
Fumonisins/metabolism , Fusarium/genetics , Genes, Fungal/genetics , Genetic Variation , Triticum/microbiology , Argentina , Calmodulin/genetics , Fumonisins/analysis , Fusarium/chemistry , Fusarium/classification , Fusarium/isolation & purification , Genes, Mating Type, Fungal/genetics , Peptide Elongation Factor 1/genetics , PhylogenyABSTRACT
The present study uses a probabilistic model to determine the growth/no growth interfaces of the spoilage wine yeast Dekkera bruxellensis CH29 as a function of ethanol (10-15%, v/v), pH (3.4-4.0) and free SO2 (0-50 mg/l) using time (7, 14, 21 and 30 days) as a dummy variable. The model, built with a total of 756 growth/no growth data obtained in a simile wine medium, could have application in the winery industry to determine the wine conditions needed to inhibit the growth of this species. Thereby, at 12.5% of ethanol and pH 3.7 for a growth probability of 0.01, it is necessary to add 30 mg/l of free SO2 to inhibit yeast growth for 7 days. However, the concentration of free SO2 should be raised to 48 mg/l to achieve a probability of no growth of 0.99 for 30 days under the same wine conditions. Other combinations of environmental variables can also be determined using the mathematical model depending on the needs of the industry.
Subject(s)
Dekkera/metabolism , Ethanol/metabolism , Food Microbiology , Models, Statistical , Sulfur Dioxide/metabolism , Wine/microbiology , Hydrogen-Ion ConcentrationABSTRACT
Knowledge and lessons from past accidental exposures in radiotherapy are very helpful in finding safety provisions to prevent recurrence. Disseminating lessons is necessary but not sufficient. There may be additional latent risks for other accidental exposures, which have not been reported or have not occurred, but are possible and may occur in the future if not identified, analyzed, and prevented by safety provisions. Proactive methods are available for anticipating and quantifying risk from potential event sequences. In this work, proactive methods, successfully used in industry, have been adapted and used in radiotherapy. Risk matrix is a tool that can be used in individual hospitals to classify event sequences in levels of risk. As with any anticipative method, the risk matrix involves a systematic search for potential risks; that is, any situation that can cause an accidental exposure. The method contributes new insights: The application of the risk matrix approach has identified that another group of less catastrophic but still severe single-patient events may have a higher probability, resulting in higher risk. The use of the risk matrix approach for safety assessment in individual hospitals would provide an opportunity for self-evaluation and managing the safety measures that are most suitable to the hospital's own conditions.
Subject(s)
Environmental Exposure/prevention & control , Patient Safety , Radiotherapy/adverse effects , Risk Assessment/methods , Humans , Likelihood FunctionsABSTRACT
The natural occurrence of alternariol (AOH) and alternariol monomethyl ether (AME) in soya beans harvested in Argentina was evaluated. Both toxins were simultaneously detected by using HPLC analysis coupled with a solid phase extraction column clean-up. Characteristics of this in-house method such as accuracy, precision and detection and quantification limits were defined by means of recovery test with spiked soya bean samples. Out of 50 soya bean samples, 60% showed contamination with the mycotoxins analyzed; among them, 16% were only contaminated with AOH and 14% just with AME. Fifteen of the positive samples showed co-occurrence of both mycotoxins analyzed. AOH was detected in concentrations ranging from 25 to 211 ng/g, whereas AME was found in concentrations ranging from 62 to 1,153 ng/g. Although a limited number of samples were evaluated, this is the first report on the natural occurrence of Alternaria toxins in soya beans and is relevant from the point of view of animal public health.
Subject(s)
Alternaria/metabolism , Food Contamination/analysis , Glycine max/chemistry , Lactones/analysis , Mycotoxins/analysis , Argentina/epidemiology , Chromatography, High Pressure Liquid/methods , Glycine max/microbiologyABSTRACT
Soybean (Glycine max L.), the main source of protein throughout the world, is used both as a food and a feedstuff. Currently, limited information about the occurrence of Fusarium species and mycotoxins in soybean grain and by-products is available. The aims of the present study were: (1) to identify toxigenic Fusarium species associated with soybean during crop reproductive stages; (2) to determine the occurrence of deoxynivalenol (DON) and nivalenol (NIV) in soybean seeds; (3) to determine the genotype and chemotype of selected Fg complex strains using molecular and chemical analysis, respectively; and (4) to characterize the strains using AFLP(s) markers. One soybean field located at Córdoba Province, Argentina, was monitored and samples of soybean tissue were harvested at three reproductive stages: flowering (R2), full seed (R6) and full maturity (R8). A total of 389 Fusarium strains F. equiseti (40%) was the most frequently species recovered followed by F. semitectum (27%) and F. graminearum (Fg) (11%). From the 40 soybean samples analysed, only two presented detectable DON levels. Based on DON occurrence on soybean seeds at ripening stages, the toxigenic ability of Fg complex strains isolated from soybean seeds, pods and flowers were analysed. The trichothecene genotype was determined by a multiplex PCR using primers based on Tri3, Tri5 and Tri7 toxin genes and then the chemotype was verified by chemical analysis. Most Fg complex strains showed 15-ADON genotype and five strains presented a DON/NIV; these also produced both toxins under in vitro culture. Neither the NIV nor the 3-ADON genotypes were detected among the members of the population evaluated. All the 15-ADON genotype strains were characterized as F. graminearum sensu stricto (lineage 7), while the strains presented a DON/NIV genotype were characterized as F. meridionale (lineage 2). The present study contributes new information on the occurrence of Fusarium species and trichothecenes toxins on soybean at the pre-harvest stages. Also, this is the first report on the chemotype, genotype and lineages among Fg complex isolated from soybean.
Subject(s)
Fusarium/genetics , Genotype , Glycine max/microbiology , Trichothecenes/chemistry , Trichothecenes/metabolism , Argentina , Fusarium/metabolism , Gene Expression Regulation, Fungal , Seeds/microbiologyABSTRACT
INTRODUCTION: Breast cancer is one of the most frequent diseases in women today, and its social impact is devastating. The risk factors focused on in recent research are mainly hormonal, genetic, and environmental though toxic habits, overweight, and obesity have also been studied. In contrast, protective factors against breast cancer include breastfeeding and daily exercise. OBJECTIVE: To ascertain the risk factors for the women with breast cancer in our study sample. MATERIAL AND METHODS: A study of cases and controls was performed on 115 women diagnosed with breast cancer and on 115 healthy women, who had been patients at the National Cancer Institute ISSEMYM in Mexico from January to December 2011. Information was collected from the women in the sample pertaining to their family history of cancer, personal background, life style, and body mass index (BMI). Breast cancer risk was estimated with multivariate logistic regression models and the chi-square test. RESULTS: It was found that there was a greater risk of breast cancer in overweight or obese women who did not do any physical exercise and either who had breastfed their children for a very short time or who had not breastfed them at all. No significant differences were found between breast cancer and toxic habits. CONCLUSIONS: The results of our study found a direct relation between breast cancer and overweight, obesity, and physical inactivity. Breastfeeding during the first months of the baby's life was found to be a protective factor against breast cancer.
Subject(s)
Breast Neoplasms/epidemiology , Adolescent , Adult , Aged , Body Mass Index , Breast Feeding , Child , Exercise/physiology , Female , Humans , Life Style , Logistic Models , Male , Mexico/epidemiology , Middle Aged , Obesity/epidemiology , Overweight/epidemiology , Puberty, Precocious/epidemiology , Risk Factors , Young AdultABSTRACT
UNLABELLED: Overweight, obesity, and breast cancer are three pathologies that are endemic in the world today and which have a great impact on society. Many research studies are currently trying to discover possible associations between these factors and to specify the links between them. OBJECTIVE: To verify whether there is a direct connection between overweight/obesity in women with breast cancer and its relation to age of diagnosis. MATERIALS AND METHODS: The sample population in this study was composed of 118 women (32-76 years of age) who had been diagnosed and treated for breast cancer in 2009-2011 at the Centro Oncológico Estatal ISSEMyM [National Cancer Institute of Mexico]. An observational, descriptive, and transversal study was performed in which a random sample of n = 60 women was divided into two groups. The first group was composed of women with breast cancer, but who were of normal weight. The second group was composed of women with breast cancer, but who were either overweight or obese. In both groups, the Patient-Generated Subjective Global Assessment (PG-SGA) was applied, and the BMI (weight and height) was determined as well as waist circumference. RESULTS: A statistically significant relation was found between age of diagnosis and weight (normal/overweight/obese) of the subjects (p < 0.05). CONCLUSIONS: The results obtained show that overweight and obesity are directly linked to breast cancer and age of diagnosis. Breast cancer was diagnosed earlier in women of normal weight.
Subject(s)
Breast Neoplasms/etiology , Obesity/complications , Overweight/complications , Adult , Age of Onset , Aged , Body Mass Index , Breast Neoplasms/epidemiology , Female , Humans , Mexico/epidemiology , Middle Aged , Obesity/epidemiology , Overweight/epidemiology , Risk , Waist CircumferenceABSTRACT
Toxoplasmosis is an infection caused by Toxoplasma gondii, an intracellular obligate parasite. Its transmission has usually been attributed to ingestion of undercooked or raw meat. The frequency of T. gondii in pork, the most common meat for human consumption in Jalisco, Mexico, is unknown; in Guadalajara city high prevalence of human toxoplasmosis has been documented. Forty-eight samples of pork meat from butcher shops in Ocotlán city were analyzed. Through bioassay, 50 g of tissue was homogenized in an acidic pepsin solution and inoculated subcutaneously to previously immunosuppressed mice. Blood samples from the mice tail vein were obtained before inoculation and 7, 14, 28, and 45 days postinoculation to analyze anti-Toxoplasma immunoglobulin (Ig) M and IgG antibody kinetics by indirect enzyme-linked immunosorbent assay. For histopathology, small fragments of the brain, lungs, heart, and skeletal muscle were extracted on day 45 and were stained with hematoxylin and eosin. Also, DNA was extracted from the pork meat for PCR amplification of the B1 gene. Even though all pork samples were negative by histopathology and PCR, IgG and IgM antibodies against T. gondii were detected in 1 of the 48 inoculated mice, reflecting a frequency of 2.1% positive pork meat, which is lower than expected but similar to that found in other regions.
Subject(s)
Food Contamination/analysis , Food Parasitology , Meat/parasitology , Toxoplasma/isolation & purification , Animals , Antibodies, Protozoan/blood , Biological Assay , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Mexico/epidemiology , Mice , Prevalence , Swine , Toxoplasma/immunology , Toxoplasmosis/prevention & control , Toxoplasmosis/transmission , Toxoplasmosis, Animal/immunology , Toxoplasmosis, Animal/parasitology , Toxoplasmosis, Animal/pathologyABSTRACT
The objective of this study was to determine the effect of water activity (a(w); 0.995, 0.98, 0.96, 0.94, 0.92, and 0.90), temperature (5, 18, 25, and 30 degrees C), incubation time (7 to 35 days), and their interactions on mycelial growth and alternariol (AOH) and alternariol monomethyl ether (AME) production. Two Alternaria alternata strains isolated from soybeans in Argentina were grown on 2% soybean extract agar. Maximum growth rates were obtained at the highest a(w) (0.995) and 25 degrees C, with growth decreasing as the water availability of the medium was reduced. Maximum amount of AOH was produced at 0.98 a(w) and 25 degrees C for both strains. Maximum AME production was obtained for both strains at 30 degrees C but different a(w) values, 0.92 and 0.94, for the strains RC 21 and RC 39, respectively. The concentrations of both toxins varied considerably depending on the a(w) and temperature interactions assayed. The two metabolites were produced from 5 to 30 degrees C and at a(w) values of 0.92 to 0.995. Although at 5 and 18 degrees C little mycotoxin was produced at a(w) lower than 0.94. Two-dimensional profiles of a(w) by temperature interactions were developed from these data to identify areas where conditions indicate a significant risk from AOH and AME accumulation on soybeans. All the conditions of a(w) and temperature that resulted in maximum production of both toxins are those found during soybean development in the field. Thus, field conditions are likely to be conducive to optimum A. alternata growth and toxin production.
Subject(s)
Alternaria/growth & development , Alternaria/metabolism , Food Contamination/analysis , Glycine max/microbiology , Mycotoxins/biosynthesis , Colony Count, Microbial , Consumer Product Safety , Lactones/metabolism , Temperature , Time Factors , Water/metabolismABSTRACT
AIMS: To determine the effects of water activity (a(W); 0.995-0.90), temperature (5, 18, 25 and 30 degrees C), time of incubation (7-35 days) and their interactions on tenuazonic acid (TA) production on 2% soybean-based agar by two Alternaria alternata strains isolated from soybean in Argentina. METHODS AND RESULTS: TA production by two isolates of A. alternata was examined under interacting conditions of a(W), temperature and time of incubation on 2% soybean-based agar. Maximum TA production was obtained for both strains at 0.98 a(W), but at 30 and 25 degrees C for the strains for RC 21 and RC 39, respectively. The toxin concentration varied considerably depending on a(W), temperature, incubation time and strain interactions. TA was produced over the temperature range from 5 to 30 degrees C and a(W) range from 0.92 to 0.995, however at 5 and 18 degrees C little TA was produced at a(W) below 0.94. Contour maps were developed from these data to identify areas where conditions indicate a significant risk for TA accumulation. CONCLUSIONS: The optimum and marginal conditions for TA production by A. alternata on soybean-based agar were identified. The results indicated that TA production by A. alternata is favoured by different temperatures in different strains. SIGNIFICANCE AND IMPACT OF THE STUDY: Data obtained provide very useful information for predicting the possible risk factors for TA contamination of soybean as the a(W) and temperature range used in this study simulate those occurring during grain ripening. The knowledge of TA production under marginal or sub-optimal temperature and a(W) conditions for growth are relevant as improper storage conditions accompanied by elevated temperature and moisture content in the grain can favour further mycotoxin production and lead to reduction in grain quality.
Subject(s)
Alternaria/metabolism , Temperature , Tenuazonic Acid/biosynthesis , Water , Argentina , Culture Media , Plant Extracts , Glycine max , Time FactorsABSTRACT
AIMS: To evaluate the mycobiota and natural levels of aflatoxins, fumonisins and zearalenone present in compound feed and home-corn grains intended for fattening pigs. METHODS AND RESULTS: Total fungi, Fusarium and Aspergillus species occurrence were examined. Aflatoxins and zearalenone were detected by thin-layer chromatography and fumonisins by high-pressure liquid chromatography. Fungal counts were generally higher than 1 x 10(5) colony forming units (CFU) ml(-1). Aspergillus flavus, Aspergillus parasiticus and Fusarium verticillioides were the most prevalent species. FB(1) and FB(2) were detected in all feed and corn samples. Aflatoxin B(1) was detected in 33.33% of initial and growing feed and in 44.44% of final feed samples. It was not detected in corn samples. All feed and corn samples were negative for AFB(2), AFG(1), AFG(2) and ZEA presence during all growing stages tested. CONCLUSIONS: Fungal counts at all growing periods exceeded the levels proposed as feed hygienic quality limits. Aflatoxin levels in all feeds and fumonisin levels in many samples were higher than the established regulations. SIGNIFICANCE AND IMPACT OF THE STUDY: The presence of mycotoxins indicates the existence of contamination. This fact requires periodic monitoring to prevent the occurrence of mycotoxicosis in animal production, to reduce the economic losses and to minimize hazards to human health.
Subject(s)
Animal Feed/microbiology , Aspergillus/isolation & purification , Fusarium/isolation & purification , Mycotoxins/analysis , Aflatoxins/analysis , Animal Feed/analysis , Animals , Argentina , Aspergillus/classification , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Edible Grain/microbiology , Food Contamination/analysis , Fumonisins/analysis , Fusarium/classification , Mycological Typing Techniques , Stem Cells , Swine , Zearalenone/analysisABSTRACT
Gibberella zeae (anamorph Fusarium graminearum) causes Fusarium head blight of wheat. The authors used amplified fragment length polymorphisms (AFLPs) to characterize the genetic structure of two G. zeae populations from commercial wheat fields. The working hypothesis was that sufficient genetic exchange occurs between local populations to prevent significant partitioning of allelic variation. We analysed 216 AFLP loci for 113 isolates collected during the 2002 harvest season. All strains had AFLP profiles typical of G. zeae lineage 7. Both populations were genotypically diverse but genetically similar and potentially part of a larger, randomly mating population, with significant genetic exchange probably occurring between the two subpopulations. Linkage disequilibrium was low, but higher than reported for many other populations of G. zeae, and about 20% of the alleles detected were specific to one of the two subpopulations - results consistent with limited gene exchange between the two subpopulations. This study extends previous work with populations of G. zeae to include those found in Argentina, one of the world's largest wheat growing countries.
Subject(s)
Amplified Fragment Length Polymorphism Analysis/methods , Fusarium/genetics , Genes, Fungal/genetics , Gibberella/genetics , Polymorphism, Restriction Fragment Length/genetics , Triticum/microbiology , Argentina , Food Contamination , Fusarium/isolation & purification , Gene Frequency/genetics , Genetic Variation/genetics , Gibberella/isolation & purification , Statistics as TopicABSTRACT
Intestinal parasites in Mexico are an endemic problem. A study was conducted in children, teenagers and adults in a rural community in Colima, Mexico to examine the prevalence and intensity of Ascaris lumbricoides infection and to evaluate the parasitological and clinical efficacy of nitazoxanide (NTZ). Two hundred and eighty children, teenagers and adults participated in this study. Parasitological diagnosis from faeces was confirmed by three consecutive stool samples using the floatation concentration Faust method. Egg counts were performed as described by the Kato-Katz technique before and after treatment. A questionnaire was systematically applied to obtain information about socio-economic status and hygienic habits. One hundred and six participants (38%) were diagnosed as harbouring intestinal parasites, and 86 of them (81%) were infected with A. lumbricoides. All patients with ascariasis infections underwent a complete physical examination before and after NTZ treatment. NTZ resolved 88% of the ascariasis cases, with a 89% clinical efficacy, and there was a 97.5% reduction in the levels of morbidity. The most intense infections for A. lumbricoides were found in housewives, and statistically significant associations were found between ascariasis and the absence of drainage and living in houses with dirt floors.
Subject(s)
Antiparasitic Agents/therapeutic use , Ascariasis/drug therapy , Ascaris lumbricoides , Intestinal Diseases, Parasitic/drug therapy , Thiazoles/therapeutic use , Adolescent , Adult , Animals , Ascariasis/epidemiology , Child , Humans , Intestinal Diseases, Parasitic/epidemiology , Mexico/epidemiology , Nitro Compounds , PrevalenceABSTRACT
A 7-year-old Mexican boy with end-stage cirrhosis underwent liver transplantation and was maintained with cyclosporine and prednisolone. No specific data about Toxoplasma gondii or cytomegalovirus (CMV) infections in the cadaver donor were available. The recipient was seronegative for Toxoplasma, but CMV-IgG positive before transplantation. Ganciclovir was administered for prophylaxis during 3 months, but 5 months later he presented with icterus and increased transaminases. Acute transplant rejection was ruled out by biopsy. A seroconversion for T. gondii IgM and IgG and a small increase in CMV-IgM antibodies were observed, although the CMV-polymerase chain reaction (PCR) was negative. Ganciclovir was re-started, and the patient improved, but 6 months later he relapsed, and chorioretinitis lesions compatible both with T. gondii and CMV infections appeared. Pyrimethamine, sulfadiazine, folinic acid, and ganciclovir were administered. The boy showed favorable clinical improvement and remained stable for 12 months. Then, new retinal CMV lesions appeared in both eyes and the PCR for CMV became positive; therefore, the patient received a new regimen of ganciclovir, and clinically improved. From these data we concluded that the child presented a reactivation of CMV and a primary infection with T. gondii after transplantation.
Subject(s)
Cytomegalovirus Infections/parasitology , Cytomegalovirus/isolation & purification , Liver Transplantation , Postoperative Complications/parasitology , Postoperative Complications/virology , Toxoplasma/isolation & purification , Toxoplasmosis/virology , Animals , Antiviral Agents/therapeutic use , Child , Cytomegalovirus Infections/drug therapy , Cytomegalovirus Infections/virology , Ganciclovir/therapeutic use , Humans , Male , Toxoplasmosis/parasitologyABSTRACT
The purpose of the present investigation was to assess the pharmacological properties of Tournefortia hartwegiana Steud (Boraginaceae), used in traditional medicine for the treatment of diabetes, diarrhea and kidney pain in Morelos, Mexico. Administration of methanol extract from aerial parts of Tournefortia hartwegiana (310 mg/kg body weight/day) for 10 days, to normoglycemic and alloxan-induced diabetic rats, significantly lowered their blood glucose levels (37 and 36%, respectively, p<0.05). The anti-diabetic and hypoglycemic activities due to the MeOH extract were similar to those produced by metformin at 120 mg/kg (positive control, p<0.05). In contrast, the hexane, dichloromethane and MeOH extracts from the same species showed no significant spasmolytic effect and did not have activity in antibacterial and Artemia salina toxicity bioassays.