In this study, molecular typing using Randomly Amplified Polymorphic DNA (RAPD-PCR) was conducted on 16 original isolates of
obtained from locusts (
ssp.
.) in Mexico (MX). The analysis included ...reference strains of the genus
sourced from various geographical regions. The isolates were identified by phenotypic (macro and micromorphology) and genotypic methods (RAPD-PCR and Amplified Fragment Length Polymorphisms (AFLP), through a multidimensional analysis of principal coordinates (PCoA) and a minimum spanning network (MST). Subsequently, Sequences-Characterized Amplified Region (SCAR) markers were developed for the molecular detection of
, these markers were chosen from polymorphic patterns obtained with 14 primers via RAPD-PCR. Phenotypic and genotypic characterization identified the MX isolates as
. Of all the polymorphic patterns obtained, only OPA04 and OPA05 were chosen, which presented species-specific bands for
, and further utilized to create SCAR markers through cloning and sequencing of the specific bands. The specificity of these two markers was confirmed via Southern hybridization. The SCAR markers (Ma-160
and Ma-151
) exhibit remarkable sensitivity, detecting down to less than 0.1 ng, as well as high specificity, as evidenced by their inability to cross-amplify or generate amplification with DNAs from other strains of
(as
) or different genera of entomopathogenic fungi (
and
). These SCAR markers yield readily detectable results, showcasing high reproducibility. They serve as a valuable tool, especially in field applications.
The atmosphere as a temporary habitat for airborne microbial communities is a valuable topic to explore, and it is through aerobiological studies that the diversity of biological particles and their ...release, emission, transport, deposition, and impact are assessed. Specific microorganisms are involved in meteorological processes, and phytosanitary and public health concerns. Airborne microbial composition is related to factors such as geographic region and weather conditions.
In this study a metagenomic approach was used to determine the composition of bacterial and fungal communities in the air of two different land-use areas (urban area and semi-rural area), during dry and rainy seasons in Mexico City. Air sampling was carried out with a Hirst-type spore trap, collecting the samples simultaneously in both study areas. Forty-two bioaerosol samples were collected, and the DNA obtained was sequenced using Next-Generation Sequencing. The results indicated that the bacterial communities were represented mainly by the phyla Actinobacteria, Proteobacteria, Firmicutes, Bacteroidetes, Cyanobacteria, and the fungal communities by the phyla Ascomycota followed by Basidiomycota. The evident changes in microbial composition were related more to seasonality than to locality, since both UA and SRA showed a high degree of urbanization, despite some differences in land use. Continuous monitoring of atmospheric bioaerosols is essential to determine the influence of meteorological factors on the composition of the aerial microbiota.
Display omitted
•Aerobiological studies should be considered in air quality monitoring.•Seasonal variations are the main factor related to changes in the composition of the bacterial and fungal communities.•The Semi-Rural Area showed greater airborne bacterial richness than the Urban Area.•The Urban Area showed greater airborne fungal richness than the Semi-Rural Area.•Airborne bacteria and fungi were represented mainly by Actinobacteria, Proteobacteria, Firmicutes, Bacteroidetes, Cyanobacteria and by Ascomycota and Basidiomycota.
Metarhizium is a genus of entomopathogenic fungi that was initially classified into three species and varieties. More recently, DNA sequencing has improved the phylogenetic resolution of Metarhizium ...which now includes 30 species. The insect host ranges vary within the genus and some species such as M. robertsii have broad host ranges, while others such as M. acridum show a narrow host range and are restricted to the order Orthoptera. Metarhizium spp. are ubiquitous naturally occurring soil inhabiting fungi, and some are rhizosphere colonisers and their diversity has been attributed to various selective factors (habitat type, climatic conditions, specific associations with plants and insect hosts). Metarhizium have been used for the biological control of insect pests that affect economically important agricultural crops and have been tested under laboratory and field conditions for the control of insect vectors of human disease, showing the effectiveness of the fungus against the target pest. In Mexico, Metarhizium species have been used for the control of insect pests such as the spittlebug (Hemiptera: Cercopidae), and locusts (Orthoptera) that affect crops such as corn, bean and sugarcane. Biosafety studies, such as dermal and intragastric tests in mammalian models have also been carried out to ensure safety to humans and other animals. Metarhizium shows great promise as an alternative to chemical insecticides that has relatively low impact on human health and the environment. Key features of Metarhizium for biocontrol of insects are outlined with special reference to their utility in Mexico.
Sporotrichosis is an endemic mycosis caused by the species of the
Sporothrix
genus, and it is considered one of the most frequent subcutaneous mycoses in Mexico. This mycosis has become a relevant ...fungal infection in the last two decades. Today, much is known of its epidemiology and distribution, and its taxonomy has undergone revisions. New clinical species have been identified and classified through molecular tools, and they now include
Sporothrix schenckii sensu stricto
,
Sporothrix brasiliensis
,
Sporothrix globosa
, and
Sporothrix luriei
. In this article, we present a systematic review of sporotrichosis in Mexico that analyzes its epidemiology, geographic distribution, and diagnosis. The results show that the most common clinical presentation of sporotrichosis in Mexico is the lymphocutaneous form, with a higher incidence in the 0–15 age range, mainly in males, and for which trauma with plants is the most frequent source of infection. In Mexico, the laboratory diagnosis of sporotrichosis is mainly carried out using conventional methods, but in recent years, several researchers have used molecular methods to identify the
Sporothrix
species. The treatment of choice depends mainly on the clinical form of the disease, the host’s immunological status, and the species of
Sporothrix
involved. Despite the significance of this mycosis in Mexico, public information about sporotrichosis is scarce, and it is not considered reportable according to Mexico’s epidemiological national system, the “Sistema Nacional de Vigilancia Epidemiológica.” Due to the lack of data in Mexico regarding the epidemiology of this disease, we present a systematic review of sporotrichosis in Mexico, between 1914 and 2019, that analyzes its epidemiology, geographic distribution, and diagnosis.
* The airborne bacteria of Mexico City are representative of urban environments. * Particle material<10 µm influenced the type and quantity of airborne bacteria. * The diversity and richness of ...bacteria were higher in the rainy season. * The emission & transport of airborne bacteria determine the atmosphere's microbiome. * Bacterias as Kocuria, Paracoccus, and Staphylococcus were in the air of Mexico City.
Bacteria in the air present patterns in space and time produced by different sources and environmental factors. Few studies have focused on the link between airborne pathogenic bacteria in densely populated cities, and the risk to the population's health. Bacteria associated with particulate matter (PM) were monitored from the air of Mexico City (Mexico). We employed a metagenomic approach to characterise bacteria using the 16S rRNA gene. Airborne bacteria sampling was carried out in the north, centre, and south of Mexico City, with different urbanisation rates, during 2017. Bacteria added to the particles were sampled using high-volume PM 10 samplers. To ascertain significant differences in bacterial diversity between zones and seasons, the Kruskal-Wallis, Wilcoxon tests were done on alpha diversity parameters. Sixty-three air samples were collected, and DNA was sequenced using next-generation sequencing. The results indicated that the bacterial phyla in the north and south of the city were Firmicutes, Cyanobacteria, Proteobacteria, and Actinobacteria, while in the central zone there were more Actinobacteria. There were no differences in the alpha diversity indices between the sampled areas. According to the OTUs, the richness of bacteria was higher in the central zone. Alpha diversity was higher in the rainy season than in the dry season; the Shannon index and the OTUs observed were higher in the central zone in the dry season. Pathogenic bacteria such as Kocuria, Paracoccus, and Micrococcus predominated in both seasonal times, while Staphylococcus, Corynebacterium, and Nocardioides were found during the rainy season, with a presence in the central zone.
In this study, molecular typing using Randomly Amplified Polymorphic DNA (RAPD-PCR) was conducted on 16 original isolates of Metarhizium acridum obtained from locusts (Schistocerca piceifrons ssp. ...piceifrons.) in Mexico (MX). The analysis included reference strains of the genus Metarhizium sourced from various geographical regions. The isolates were identified by phenotypic (macro and micromorphology) and genotypic methods (RAPD-PCR and Amplified Fragment Length Polymorphisms (AFLP), through a multidimensional analysis of principal coordinates (PCoA) and a minimum spanning network (MST). Subsequently, Sequences-Characterized Amplified Region (SCAR) markers were developed for the molecular detection of M. acridum, these markers were chosen from polymorphic patterns obtained with 14 primers via RAPD-PCR. Phenotypic and genotypic characterization identified the MX isolates as M. acridum. Of all the polymorphic patterns obtained, only OPA04 and OPA05 were chosen, which presented species-specific bands for M. acridum, and further utilized to create SCAR markers through cloning and sequencing of the specific bands. The specificity of these two markers was confirmed via Southern hybridization. The SCAR markers (Ma-160sub.OPA-05 and Ma-151sub.OPA-04) exhibit remarkable sensitivity, detecting down to less than 0.1 ng, as well as high specificity, as evidenced by their inability to cross-amplify or generate amplification with DNAs from other strains of Metarhizium (as Metarhizium anisopliae) or different genera of entomopathogenic fungi (Cordyceps fumosorosea and Akanthomyces lecanii). These SCAR markers yield readily detectable results, showcasing high reproducibility. They serve as a valuable tool, especially in field applications.
Infectious keratitis and sclerokeratitis caused by filamentous fungi prevail in agricultural regions with tropical and subtropical climates and are related mostly to mild abrasive corneal trauma ...especially after vegetable matter related injury. Biotechnological advances have introduced biological control agents in agriculture such as fungal-based biocontrol agents that use Beauveria and Metarhizium species as bioinsecticides. Keratitis and sclerokeratitis are the most frequent pathologies associated to Beauveria and Metarhizium infection that are the main entomopathogenic fungi used in biological control, although other clinical cases such as sinus, skin lesions, and disseminated infections have been reported. Search of publications was carried out using the databases: Scopus, Pubmed, ScienceDirect, MedLine Scielo. A total of 30 articles were retrieved from 1984 – 2021. From these, 17 keratitis and one sclerokeratitis clinical cases were related to Beauveria infection, while Metarhizium was linked to 13 keratitis cases and two sclerokeratitis clinical cases. Female sex predominated in both Metarhizium and Beauveria clinical cases, there was no significant difference in sclerokeratitis / keratitis by sex. Contact lenses use was a factor reported in 66.6% cases of infection with Metarhizium and 22.2% with Beauveria. The review of clinical cases of keratitis and sclerokeratitis related to Beauveria and Metarhizium suggests the need to consider entomopathogenic fungi in ocular pathologies and the risk that imply the misuse of contact lenses and agricultural/gardening activities.
Metarhizium
Sorokin is a wide spread entomopathogenic fungal genus that is also a root symbiont and some isolates may be potentially useful in agriculture applications. Physiological variations ...applicable in biological control have not been fully evaluated in Mexican strains. This study identified 30 strains from different insect hosts and states of Mexico selected because they represent the main sugar cane and corn plantations of the country. Their thermotolerance profiles (8, 15, 28 and 35 °C), insect virulence (LT50 in
Galleria mellonella
(Linnaeus) (Lepidoptera: Pyralidae) larvae), possible association with plant roots, and phylogenetic placement (using 5′TEF, IGS sequence information, and RFLP analysis) were assessed. Results showed no cold-active strains and most showed restricted growth at 35 °C. Insect virulence bioassays against
G. mellonella
showed highly virulent strains. Most of the strains showed an ability to associate with roots of
Phaseolus vulgaris
(Burkart) (Fabales: Fabaceae). RFLP analysis with 5′TEF and Pr1 revealed three distinct genetic groups. Phylogenetic analysis identified the 30 strains as
Metarhizium anisopliae.
(Metchnikoff) Sorokin,
M. robertsii
(J.F. Bisch., Rehner & Humber),
M. guizhouense
(Q. T. Chen & H. L. Guo), or
M. pinghaense
(Q.T. Chen & H.L. Guo), as well as two strains that belong to a new clade (
Metarhizium
sp. indet. 1). These data demonstrate the complexity of
Metarhizium
species and the need to study their physiological and phylogenetic aspects for a more adequate assessment of their potential use in agricultural systems.
Isaria fumosorosea (formerly Paecilomyces fumosoroseus) is an entomopathogenic fungus that has been proposed as a low risk environmental alternative to the use of chemical insecticides to control ...agricultural pests and disease vectors. Although there are some mycoinsecticides already being marketed in many countries, not all their biosafety protocols have been published. The acute dermal toxicity test in an animal model is one in a series of biosafety protocols that must be developed, in order to provide information on health hazards, while taking into consideration the periods that the workers are in direct contact with the microbial agent when applied for the control of pests. For this test, we used I. fumosorosea monospore culture EH-506/3, isolated in Mexico from the Bemisia tabaci whitefly, applying a dose of 2 g/kg of animal body weight, on the shaved skin of 16 New Zealand rabbits, with an exposure time of 24 h. Clinical observations were conducted to evaluate the presence of erythema, edema and other alterations in the skin, as well as the behavior and health of the animals, for a period of 14 days. None of the rabbits showed clinical signs of any disease and their body weight corresponded to the expected weight for a healthy rabbit. The test showed no inflammatory reactions in the skin, supporting the safety of a single dose of this fungus in dermal exposure. Therefore, these data support the safety of I. fumosorosea EH-506/3 when applied to the skin.
Abstract Metarhizium anisopliae is an anamorphic fungus widely studied due to its use as a biological control agent. In Mexico, it is mainly used as an integrated management strategy to control ...populations of spittlebugs (Hemiptera: Cercopidae) that affect sugarcane fields and cattle pastures. In this study, 13 strains isolated from Aeneolamia spp. (Hemiptera: Cercopidae) from the main areas of sugarcane production of Mexico and 11 reference strains of Metarhizium from different insect hosts and geographic origins were evaluated based on their conidial dimensions, thermotolerance at 15, 25, 30, and 35 ºC, random amplification of polymorphic DNA (RAPD) patterns using a combined analysis with 14 different oligonucleotides and diversity estimators, and a phylogenetic analysis with the ribosomal RNA internal transcribed spacer (ITS) region. All strains used in this study showed typical morphological characteristics corresponding to M. anisopliae and were able to grow at 25 and 30 ºC with restricted growth at low (15 ºC) and high temperatures (35 ºC). Polymorphism analysis clustered all strains from Aeneolamia sp. in one well-defined group with low variability among them. Phylogenetic relationships based on nuclear ribosomal ITS region sequences recovered a subclade within M. anisopliae formed by 10 of the Mexican strains.
PDF
