Experimental evolution alters the rate and temporal pattern of population growth in Batrachochytrium dendrobatidis,a lethal fungal pathogen of amphibians

Virulence of infectious pathogens can be unstable and evolve rapidly depending on the evolutionary dynamics of the organism. Experimental evolution can be used to characterize pathogen evolution, often with the underlying objective of understanding evolution of virulence. We used experimental evolution techniques (serial transfer experiments) to investigate differential growth and virulence of Batrachochytrium dendrobatidis (Bd), a fungal pathogen that causes amphibian chytridiomycosis. We tested two lineages of Bd that were derived from a single cryo‐archived isolate; one lineage (P10) was passaged 10 times, whereas the second lineage (P50) was passaged 50 times. We quantified time to zoospore release, maximum zoospore densities, and timing of zoospore activity and then modeled population growth rates. We also conducted exposure experiments with a susceptible amphibian species, the common green tree frog (Litoria caerulea) to test the differential pathogenicity. We found that the P50 lineage had shorter time to zoospore production (T_min), faster rate of sporangia death (d_s), and an overall greater intrinsic population growth rate (λ). These patterns of population growth in vitro corresponded with higher prevalence and intensities of infection in exposed Litoria caerulea, although the differences were not significant. Our results corroborate studies that suggest that Bd may be able to evolve relatively rapidly. Our findings also challenge the general assumption that pathogens will always attenuate in culture because shifts in Bd virulence may depend on laboratory culturing practices. These findings have practical implications for the laboratory maintenance of Bd isolates and underscore the importance of understanding the evolution of virulence in amphibian chytridiomycosis.     

Temperature alters reproductive life history patterns in Batrachochytrium dendrobatidis,a lethal pathogen associated with the global loss of amphibians

Understanding how pathogens respond to changing environmental conditions is a central challenge in disease ecology. The environmentally sensitive fungal pathogen Batrachochytrium dendrobatidis (Bd), which causes the amphibian disease chytridiomycosis, has spread globally causing amphibian extirpations in a wide variety of climatic regions. To gain an in‐depth understanding of Bd's responses to temperature, we used an integrative approach, combining empirical laboratory experiments with mathematical modeling. First, we selected a single Bd isolate and serially propagated two lineages of the isolate for multiple generations in two stable thermal conditions: 4°C (cold‐adapted lineage) and 23°C (warm‐adapted lineage). We quantified the production of infectious zoospores (fecundity), the timing of zoospore release, and zoospore activity in reciprocal temperature transplant experiments in which both Bd lineages were grown in either high or low temperature conditions. We then developed population growth models for the Bd lineages under each set of temperature conditions. We found that Bd had lower population growth rates, but longer periods of zoospore activity in the low temperature treatment (4°C) compared to the high temperature treatment (23°C). This effect was more pronounced in Bd lineages that were propagated in the low temperature treatment (4°C), suggesting a shift in Bd's response to low temperature conditions. Our results provide novel insights into the mechanisms by which Bd can thrive in a wide variety of temperature conditions, potentially altering the dynamics of chytridiomycosis and thus, the propensity for Bd to cause amphibian population collapse. We also suggest that the adaptive responses of Bd to thermal conditions warrant further investigation, especially in the face of global climate change.     

Composition of symbiotic bacteria predicts survival in Panamanian golden frogs infected with a lethal fungus

Symbiotic microbes can dramatically impact host health and fitness, and recent research in a diversity of systems suggests that different symbiont community structures may result in distinct outcomes for the host. In amphibians, some symbiotic skin bacteria produce metabolites that inhibit the growth of Batrachochytrium dendrobatidis (Bd), a cutaneous fungal pathogen that has caused many amphibian population declines and extinctions. Treatment with beneficial bacteria (probiotics) prevents Bd infection in some amphibian species and creates optimism for conservation of species that are highly susceptible to chytridiomycosis, the disease caused by Bd. In a laboratory experiment, we used Bd-inhibitory bacteria from Bd-tolerant Panamanian amphibians in a probiotic development trial with Panamanian golden frogs, Atelopus zeteki, a species currently surviving only in captive assurance colonies. Approximately 30% of infected golden frogs survived Bd exposure by either clearing infection or maintaining low Bd loads, but this was not associated with probiotic treatment. Survival was instead related to initial composition of the skin bacterial community and metabolites present on the skin. These results suggest a strong link between the structure of these symbiotic microbial communities and amphibian host health in the face of Bd exposure and also suggest a new approach for developing amphibian probiotics.     

Altitudinal distribution of chytrid (Batrachochytrium dendrobatidis) infection in subtropical Australian frogs

The disappearance of amphibian populations from seemingly pristine upland areas worldwide has become a major focus of conservation efforts in the last two decades, and a parasitic chytrid fungus, Batrachochytrium dendrobatidis, is thought to be the causative agent of the population declines. We examined the altitudinal distribution of chytrid infections in three stream‐dwelling frog species (Litoria wilcoxii, L. pearsoniana and L. chloris) in southeast Queensland, Australia, and hypothesized that if B. dendrobatidis were responsible for the disappearance of high‐altitude frog populations, infection prevalence and intensity would be greatest at higher altitudes. Overall, 37.7% of the 798 adult frogs we sampled were infected with B. dendrobatidis, and infections were found in all the populations we examined. Contrary to our initial hypothesis, we found no consistent evidence that high‐altitude frogs were more likely to be infected than were lowland frogs. Further, the intensity of fungal infections (number of zoospores) on high‐altitude frogs did not differ significantly from that of lowland frogs. Batrachochytrium dendrobatidis appears to be capable of infecting frogs at all altitudes in the subtropics, suggesting that all populations are at risk of decline when conditions favour disease outbreaks. We did find evidence, however, that chytrid infections persist longer into summer in upland as compared with lowland areas, suggesting that montane amphibian populations remain susceptible to disease outbreaks for longer periods than do lowland populations. Further, we found that at high altitudes, temperatures optimal for chytrid growth and reproduction coincide with frog metamorphosis, the life‐stage at which frogs are most susceptible to chytrid infections. While these altitudinal differences may account for the differential population‐level responses to the presence of B. dendrobatidis, the reason why many of southeast Queensland's montane frog populations declined precipitously while lowland populations remained stable has yet to be resolved.     

Global and endemic Asian lineages of the emerging pathogenic fungus Batrachochytrium dendrobatidis widely infect amphibians in China

Aim Panzootic chytridiomycosis caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd) is the proximate cause of rapid amphibian declines across diverse biomes. While the origin of Bd remains unclear, increasingly the global trade in amphibians is associated with the spread of the infection. Global samples of Bd genotypes from previously unsampled regions are essential to test this hypothesis. In this paper, we present a study of the prevalence and phylogeny of Bd in both invasive and native amphibian species in markets and in the wild in ten provinces of China. Location China. Method We used a nested PCR assay to amplify the ribosomal internal transcribed spacer region of Bd followed by sequencing. Result Our results showed 246 of 2734 amphibians testing positive for Bd, with 157 positive samples in the wild (7.6%) and 89 in markets (13.5%). 30 haplotypes of Bd were identified, including 20 first detections. Introduced Lithobates catesbeianus had the highest prevalence of infection and the largest number of Bd haplotypes in both the wild and markets. Phylogenetic analysis based on 73 haplotypes (57 from Asia and 16 from other continents) showed that a unique, well‐supported, basal haplotype is present in Asia. Phylogeographical analyses revealed that some geographical structure exists amongst a subset of global haplotypes. Main conclusions Strains of the basal haplotype infected Babina pleuraden, an amphibian that is endemic to China, and Andrias japonicus, endemic to Japan, showing that Southeast Asia harbours a novel endemic lineage of amphibian‐associated Bd. Our data suggest that Bd in Asia pre‐dates the expansion of a globalized lineage of Bd, a finding that is indicative of a broader association of amphibians and chytrids than has previously been recognized. More genetic data from Bd isolates are needed to reveal the phylogenetic relationship of Bd in China compared to that found elsewhere.     

Known and estimated distribution in Mexico of Batrachochytrium dendrobatidis,a pathogenic fungus of amphibians

Chytridiomycosis caused by fungus Batrachochytrium dendrobatidis (Bd) is one of the decline global causes of amphibians. Currently, it is distributed throughout a broad range of climates and ecosystems around the world. An epidemic wave of chytridiomycosis began in North America, resulting in population decline and local extinction of many species, reconfiguring species composition of amphibian communities in the Americas. In Mexico, Bd has caused an amphibian population decrease, and its potential distribution area has not been determined. We reviewed the number of species infected, obtaining Bd frequency of infection by land use and vegetation type, and by elevation range. We examined the known distribution of Bd, estimated the potential distribution, and obtained the bioclimate variables relevant for Bd. Our results indicate that in Mexico, Bd has been detected in 78 species of amphibians in 10 families, from 29 different land use and vegetation types, with cloud forest having the highest number of cases (139) and infected species (15). Bd occurs over an elevation range of 1–3,300 m asl and is most frequent at 1,200–1,500 m asl (36%). In addition to the regions previously described as suitable for Bd, our model included desert, coastal, and tropical forest regions, revealing an increase in the area where amphibians could be at risk of infection. Distribution of Bd is mainly associated with temperature of the wettest quarter and potential evapotranspiration of the warmer quarter. We offer an estimate of the ideal conditions for Bd in Mexico, also information for future studies on Bd and the conservation of amphibians. Abstract in Spanish is available with online material.     

Current and predicted distribution of the pathogenic fungus Batrachochytrium dendrobatidis in Colombia,a hotspot of amphibian biodiversity

Global amphibian declines have been attributed to several factors including the chytrid fungal pathogen, Batrachochytrium dendrobatidis (Bd), that infects hosts’ skin and causes death by inhibiting immune response and impairing osmoregulatory function. Here, we integrate extensive new field data with previously published locality records of Bd in Colombia, a megadiverse and environmentally heterogeneous country in northwestern South America, to determine the relative importance of environmental variables and reproductive mode for predicting the risk of Bd infection in amphibians. We surveyed 81 localities across Colombia and sampled 2876 individual amphibians belonging to 14 taxonomic families. Through a combination of end‐point PCR and real‐time PCR analyses, Bd was detected in 338 individuals (12%) representing 43 localities (53%) distributed from sea level to 3200 m. We found that annual mean temperature and variables related with seasonality in precipitation and temperature appeared to define the most suitable areas for the establishment of the pathogen. In addition, prevalence of infection appeared to be higher in species with a terrestrial reproductive mode. Our study provides the first large‐scale study of the current and potential distribution of Bd in the biodiversity hotspot centered on Colombia. We hope the newly provided information on the extent of the distribution of the pathogen and the potential areas where Bd may impact the amphibian fauna will inform decision making by environmental authorities and future conservation action.     

Persistence of the emerging pathogen Batrachochytrium dendrobatidis outside the amphibian host greatly increases the probability of host extinction

Pathogens do not normally drive their hosts to extinction; however, Batrachochytrium dendrobatidis, which causes amphibian chytridiomycosis, has been able to do so. Theory predicts that extinction can be caused by long-lived or saprobic free-living stages. The hypothesis that such a stage occurs in B. dendrobatidis is supported by the recent discovery of an apparently encysted form of the pathogen. To investigate the effect of a free-living stage of B. dendrobatidis on host population dynamics, a mathematical model was developed to describe the introduction of chytridiomycosis into a breeding population of Bufo bufo, parametrized from laboratory infection and transmission experiments. The model predicted that the longer that B. dendrobatidis was able to persist in water, either due to an increased zoospore lifespan or saprobic reproduction, the more likely it was that it could cause local B. bufo extinction (defined as decrease below a threshold level). Establishment of endemic B. dendrobatidis infection in B. bufo, with severe host population depression, was also possible, in agreement with field observations. Although this model is able to predict clear trends, more precise predictions will only be possible when the life history of B. dendrobatidis, including free-living stages of the life cycle, is better understood.     

Identification and antimicrobial susceptibility of porcine bacteria that inhibit the growth of Brachyspira hyodysenteriae in vitro

Aims: To identify bacilli, lactic acid bacteria and bifidobacteria that inhibit the growth of Brachyspira hyodysenteriae. Methods and Results: A total of 80 isolates were obtained from various porcine intestinal compartments using selective conditions and grouped into 15 similarity clusters based on whole‐cell protein profiles. Random amplified polymorphic DNA PCR patterns identified 24 genotypes. 16S rDNA sequencing assigned all genotypes, except eight aerobes, to established species (Bacillus subtilis, Enterococcus faecium, Lactobacillus salivarius, Lactobacillus mucosae, Lactobacillus reuteri, Lactobacillus amylovorus, Bifidobacterium thermophilum). According to their minimum inhibitory concentrations, four strains (Ent. faecium, Lact. reuteri, Lact. amylovorus, Bif. thermophilum) were susceptible to all clinically relevant antibiotics. Two lactobacilli showing multiresistance harboured the erm(B) determinant. A cross‐section of eight representative strains was examined for growth suppression of two strains of Brach. hyodysenteriae, the aetiological agent of swine dysentery, and compared with intestinal strains derived from other animal sources. The Brachyspira strains were inhibited by strains of Lact. salivarius, Bif. thermophilum, Ent. faecium and B. subtilis. Conclusions: Three porcine strains of Ent. faecium, Bif. thermophilum and B. subtilis were found to be suitable as probiotic candidates because of their well‐established identity, antibiotic susceptibility and antagonistic activity. Significance and Impact of the Study: For the first time, antagonistic activity of well‐characterized porcine strains against Brach. hyodysenteriae is presented. These findings suggest that certain intestinal strains might have a potential as probiotic feed additives for prevention of swine dysentery.     

Predicting the Distribution of the Amphibian Pathogen Batrachochytrium dendrobatidis in the New World1

One application of ecological niche modeling is predicting suitable areas for the establishment of invasive species. Herein, I model the fundamental niche of the chytrid fungus Batrachochytrium dendrobatidis, a pathogen linked to amphibian declines on several continents. Niche models were generated with the Genetic Algorithm of Rule‐Set Prediction using point distribution data of the pathogen and digital maps of environmental variables integrated in a GIS environment. The distribution of regions suitable for B. dendrobatidis in the New World is extensive and includes significant portions of: (1) Sierra Madre Occidental pine‐oak forest; (2) Sonoran and Sinaloan dry forest; (3) Veracruz moist forest; (4) Central America east from the Isthmus of Tehuantepec; (5) Caribbean Islands; (6) temperate forest in Chile and western Argentina south of latitude 30°S; (7) Andes above 1000 m of altitude in Venezuela, Colombia, and Ecuador; (8) eastern slopes of the Andes in Peru and Bolivia; (9) Brazilian Atlantic forest; (10) Uruguay, Paraguay, and northeastern Argentina; (11) southwestern and Madeira‐Tapajós Amazonian tropical rainforests. The regions with the highest suitability for B. dendrobatidis include habitats that contain the world's most diverse amphibian faunas. Models were built with New World localities, but also showed strong predictability for B. dendrobatidis localities in the Old World. Out of a total of 59 reported Old World localities for B. dendrobatidis, 56 occurred within regions with high predicted suitability. I also present analyses of the environmental envelope of B. dendrobatidis and discuss the implications of the results for the conservation of amphibians in the neotropics.     

Proteomic and phenotypic profiling of the amphibian pathogen Batrachochytrium dendrobatidis shows that genotype is linked to virulence

Population genetics of the amphibian pathogen Batrachochytrium dendrobatidis ( Bd ) show that isolates are highly related and globally homogenous, data that are consistent with the recent epidemic spread of a previously endemic organism. Highly related isolates are predicted to be functionally similar due to low levels of heritable genetic diversity. To test this hypothesis, we took a global panel of Bd isolates and measured (i) the genetic relatedness among isolates, (ii) proteomic profiles of isolates, (iii) the susceptibility of isolates to the antifungal drug caspofungin, (iv) the variation among isolates in growth and phenotypic characteristics, and (v) the virulence of isolates against the European common toad Bufo bufo . Our results show (i) genotypic differentiation among isolates, (ii) proteomic differentiation among isolates, (iii) no significant differences in susceptibility to caspofungin, (iv) differentiation in growth and phenotypic/morphological characters, and (v) differential virulence in B. bufo . Specifically, our data show that Bd isolates can be profiled by their genotypic and proteomic characteristics, as well as by the size of their sporangia. Bd genotypic and phenotypic distance matrices are significantly correlated, showing that less-related isolates are more biologically unique. Mass spectrometry has identified a set of candidate genes associated with inter-isolate variation. Our data show that, despite its rapid global emergence, Bd isolates are not identical and differ in several important characters that are linked to virulence. We argue that future studies need to clarify the mechanism(s) and rate at which Bd is evolving, and the impact that such variation has on the host–pathogen dynamic.     

Genetic evidence for a high diversity and wide distribution of endemic strains of the pathogenic chytrid fungus Batrachochytrium dendrobatidis in wild Asian amphibians

Population declines and extinctions of amphibians have been attributed to the chytrid fungus Batrachochytrium dendrobatidis (Bd), especially one globally emerging recombinant lineage (‘Bd‐GPL’). We used PCR assays that target the ribosomal internal transcribed spacer region (ITS) of Bd to determine the prevalence and genetic diversity of Bd in South Korea, where Bd is widely distributed but is not known to cause morbidity or mortality in wild populations. We isolated Korean Bd strains from native amphibians with low infection loads and compared them to known worldwide Bd strains using 19 polymorphic SNP and microsatellite loci. Bd prevalence ranged between 12.5 and 48.0%, in 11 of 17 native Korean species, and 24.7% in the introduced bullfrog Lithobates catesbeianus. Based on ITS sequence variation, 47 of the 50 identified Korean haplotypes formed a group closely associated with a native Brazilian Bd lineage, separated from the Bd‐GPL lineage. However, multilocus genotyping of three Korean Bd isolates revealed strong divergence from both Bd‐GPL and the native Brazilian Bd lineages. Thus, the ITS region resolves genotypes that diverge from Bd‐GPL but otherwise generates ambiguous phylogenies. Our results point to the presence of highly diversified endemic strains of Bd across Asian amphibian species. The rarity of Bd‐GPL‐associated haplotypes suggests that either this lineage was introduced into Korea only recently or Bd‐GPL has been outcompeted by native Bd strains. Our results highlight the need to consider possible complex interactions among native Bd lineages, Bd‐GPL and their associated amphibian hosts when assessing the spread and impact of Bd‐GPL on worldwide amphibian populations.     

Screening from pickled vegetables the potential probiotic strains of lactic acid bacteria able to inhibit the Salmonella invasion in mice

Aims: To screen from pickled vegetables the potential probiotic lactic acid bacteria (LAB) strains with antagonistic activity against Salmonella invasion in host. Methods and Results: Probiotic properties including acid and bile tolerance as well as inhibition on pathogenic bacteria were used for screening of LAB strains from pickled vegetables. Two strains, i.e Pediococcus pentosaceus MP12 and Lactobacillus plantarum LAP6, were selected and further assayed for their activities against Salmonella invasion in mouse liver and spleen. For these two LAB strains, strain LAP6 was able to adhere to the mouse intestinal epithelium cells. Conclusions: In screening of the probiotic strains able to inhibit the Salmonella invasion in host, factors other than the adherence to host intestinal epithelium may contribute some roles. Significance and Impact of the Study: Probiotic LAB strains with activity against Salmonella invasion in host could be isolated from vegetable origins. These strains may be used for vegetable processing.     

石磺海牛共附生细菌的分离和活性菌株筛选

[目的]研究深圳大鹏半岛海域石磺海牛中可培养的共附生细菌的数量和种类,并对分离获得菌株的代谢产物进行活性筛选.[方法]通过R2A平板培养、分离纯化和16S rRNA测序,分析鉴定石磺海牛中5个部位可培养细菌;使用分离菌株的菌液及发酵液上清,测定对群体感应信号分子降解的活性和抗生物膜活性.[结果]从石磺海牛中共分离到21...     

气体环境对厌氧益生菌乳双歧杆菌V9菌株生长影响的研究

<正>乳双歧杆菌(Bifidobacterium lactis)V9菌株分离自健康蒙古族儿童肠道,已被广泛应用于开发各类益生菌产品[1]。由于双歧杆菌为厌氧菌[2],因此培养和保存时的气体环境会影响其活菌数量和益生功效,也成为该菌实现产业化道路上必须关注的重要环节。本刊于2012年第7期刊登了其木格苏都、张和平等的文章"不同气体环境对益生菌Bifidobacterium lactis V9生长的影响"[3]。作者对该菌在不同气体环境中的生长代谢特性进行了系统研究,明确了在有微量二氧化碳和氧气存在的环境下更有利于其生长。该研究为提高乳双歧     

Diversity in growth patterns among strains of the lethal fungal pathogen <Emphasis Type="Italic">Batrachochytrium dendrobatidis</Emphasis> across extended thermal optima

The thermal sensitivities of organisms regulate a wide range of ecological interactions, including host–parasite dynamics. The effect of temperature on disease ecology can be remarkably complex in disease systems where the hosts are ectothermic and where thermal conditions constrain pathogen reproductive rates. Amphibian chytridiomycosis, caused by the pathogen Batrachochytrium dendrobatidis (Bd), is a lethal fungal disease that is influenced by temperature. However, recent temperature studies have produced contradictory findings, suggesting that our current understanding of thermal effects on Bd may be incomplete. We investigated how temperature affects three different Bd strains to evaluate diversity in thermal responses. We quantified growth across the entire thermal range of Bd, and beyond the known thermal limits (T _max and T _min). Our results show that all Bd strains remained viable and grew following 24 h freeze (?12 °C) and heat shock (28 °C) treatments. Additionally, we found that two Bd strains had higher logistic growth rates (r) and carrying capacities (K) at the upper and lower extremities of the temperature range, and especially in low temperature conditions (2–3 °C). In contrast, a third strain exhibited relatively lower growth rates and carrying capacities at these same thermal extremes. Overall, our results suggest that there is considerable variation among Bd strains in thermal tolerance, and they establish a new thermal sensitivity profile for Bd. More generally, our findings point toward important questions concerning the mechanisms that dictate fungal thermal tolerances and temperature-dependent pathogenesis in other fungal disease systems.     

Production of the antifungal compounds phenazine and pyrrolnitrin from Pseudomonas chlororaphis O6 is differentially regulated by glucose

Aims: To determine whether glucose in growth medium affects secondary metabolite production and biocontrol efficacy of Pseudomonas chlororaphis O6. Methods and Results: The secondary metabolites pyrrolnitrin and phenazines antagonize phytopathogenic fungi. The expression of the prnA gene encoding tryptophan halogenase, the first step in pyrrolnitrin biosynthesis, required the stationary‐phase sigma factor, RpoS. Mutations in rpoS and prnA in Ps. chlororaphis O6 eliminated antifungal activity against Rhizoctonia solani and Fusarium graminearum. Pyrrolnitrin production was reduced by glucose in growth media, whereas phenazine levels were increased. The efficacy of Ps. chlororaphis O6 in the biocontrol of tomato late blight was reduced by addition of glucose to the growth medium. Conclusions: Regulation by glucose of pyrrolnitrin production influenced the efficacy of the biocontrol of tomato leaf blight. Significance and Impact of the Study: The nutritional regulation of secondary metabolite production from a soil pseudomonad may account, at least in part, for the variability of biocontrol under field conditions.     

New antifungal agents that inhibit the growth of Candida Species: Dichlorinated 8-quinolinols

Five dichlorinated 8-quinolinols (2,5- 5,6-, 3,5-, 3,7-, and 4,5-dichloro-8-quinolinol) were tested against Candida albicans and C. Tropicalis in Sabouraud dextrosebroth with and without bovine serum. The 5,6-, 3,5-, and 3,7-dichloro-8-quinolinols proved to be more effective than the control, 5-fluorocytosine. In cytotoxicity tests employing baby hamster kidney (BHK) cells, all test agents proved to be more cytotoxic than the control. However, the minimum inhibitory concentration (MIC) of 3,5-dichloro-8-quinolinol to both fungi was only one tenth the cytotoxic dose,suggesting that the compound may be useful as a topical or systemic antifungal agent.This revised version was published online in October 2005 with corrections to the Cover Date.     

Fengycin antibiotics isolated from B-FS01 culture inhibit the growth of Fusarium moniliforme Sheldon ATCC 38932

Strain B-FS01, isolated from rape (Brassica napus) stem infected by Slerotinia sclerotiorum and identified as Bacillus subtilis, exhibited predominantly antagonistic activities against Fusarium moniliforme Sheldon ATCC 38932. Antifungal active compounds (AAC) were isolated and purified from the cultures of strain B-FS01 against ATCC 38932. The HPLC/electron spray ionization/collision-induced dissociation mass spectrum of AAC revealed a cluster of fengycin homologues containing fengycins A, fengycins B and a new type of fengycin. Further toxic assay of AAC in vitro against F. moniliforme indicated that AAC could strongly inhibit the growth of both mycelia and spores. In addition, treatment with AAC significantly modified the maize seed infection by ATCC 38932.