Bacterial Diversity Associated with Anastrepha obliqua Males Change Under Mass-Rearing Conditions and with Irradiation.

Recent advances in understanding the symbiotic interactions between bacteria and fruit flies have shown that they are relevant for mass rearing and the sterile insect technique (SIT). SIT involves mass production and release of sterile insects that would copulate with their wild conspecifics and thus decrease the population growth rate. The irradiation process used to sterilize mass-reared flies can modify the diversity and structure of the midgut bacterial communities, which could affect sterile male survival, flight capacity, and sexual competitiveness. Our aim was to compare bacterial communities in the midgut of wild and mass-reared Anastrepha obliqua (Macquart) males irradiated at 0, 60, and 80 Gy. After adult's emergence, their midguts were dissected, DNA was extracted, and high-throughput sequencing of the V3-V4 region of the 16S rDNA gene was performed. A total of 11 phyla, 17 classes, 47 families, and 52 genera of bacteria were identified. The most representative phylum was Proteobacteria and the predominant family was Enterobacteriaceae. We found that wild males had a different intestinal bacterial community from mass-reared males. In addition, irradiation at 60 and 80 Gy caused changes in the diversity and structure of the midgut microbiota of these sterile males, suggesting that mass rearing and irradiation cause artificial selection of the bacterial communities in the gut of A. obliqua males.

UBA2 variants underlie a recognizable syndrome with variable aplasia cutis congenita and ectrodactyly.

PURPOSE: The human chromosome 19q13.11 deletion syndrome is associated with a variable phenotype that includes aplasia cutis congenita (ACC) and ectrodactyly as specific features. UBA2 (ubiquitin-like modifier-activating enzyme 2) lies adjacent to the minimal deletion overlap region. We aimed to define the UBA2-related phenotypic spectrum in humans and zebrafish due to sequence variants and to establish the mechanism of disease. METHODS: Exome sequencing was used to detect UBA2 sequence variants in 16 subjects in 7 unrelated families. uba2 loss of function was modeled in zebrafish. Effects of human missense variants were assessed in zebrafish rescue experiments. RESULTS: Seven human UBA2 loss-of-function and missense sequence variants were detected. UBA2-phenotypes included ACC, ectrodactyly, neurodevelopmental abnormalities, ectodermal, skeletal, craniofacial, cardiac, renal, and genital anomalies. uba2 was expressed in zebrafish eye, brain, and pectoral fins; uba2-null fish showed deficient growth, microcephaly, microphthalmia, mandibular hypoplasia, and abnormal fins. uba2-mRNAs with human missense variants failed to rescue nullizygous zebrafish phenotypes. CONCLUSION: UBA2 variants cause a recognizable syndrome with a wide phenotypic spectrum. Our data suggest that loss of UBA2 function underlies the human UBA2 monogenic disorder and highlights the importance of SUMOylation in the development of affected tissues.

Brevipalpus mites associated with coffee plants (Coffea arabica and C. canephora) in Chiapas, Mexico.

Tenuipalpid mites of the genus Brevipalpus are of significant economic and quarantine importance in agriculture. They can damage and vector phytopathogenic viruses in coffee plantations and other crops. In this study, we focused on: identification of the Brevipalpus species, assessment of the spread of Brevipalpus-associated viruses (CoRSV, CiLV-N, CiLVC and CiLVC2), and mite population fluctuations over the course of 1 year. The study was conducted in coffee plantations in Soconusco, a coffee-producing region in Chiapas, Mexico. The collected mites of the Brevipalpus phoenicis sensu lato species complex (635) were identified as Brevipalpus papayensis (80.2%) and B. yothersi (19.8%) based on morphological and molecular characteristics. Their population abundance was low and there were no indications for virosis. The highest mite abundance was recorded in August-September and the lowest in February-March. An interaction was observed between mite abundance and coffee species in open-growth and shaded cultivation at various altitudes. Brevipalpus papayensis was most abundant in Coffea arabica var. Bourbon, in shaded (80%) growing conditions at an altitude of 1300 m above sea level. In C. canephora (in open-growth cultivation conditions at low altitude), B. yothersi was more abundant than in C. arabica, and as abundant as B. papayensis. We are of the opinion that, at this moment, B. papayensis and B. yothersi do not present risks to the production of coffee for the studied plantations. However, as the coffee-producing regions of Mexico are ecologically diverse, it will be important to continue examining the status of Brevipalpus mite populations in other regions in Mexico.

Identification of mutations in the S gene of hepatitis B virus in HIV positive Mexican patients with occult hepatitis B virus infection.

INTRODUCTION AND AIM: Occult hepatitis B virus infection (OBI) is characterized by the presence of replication-competent hepatitis B virus (HBV) DNA in the liver and/or serum of patients with undetectable levels of the HBV surface antigen (HBsAg). Due to the shared infection routes HIV positive patients are at higher risk of developing OBI, thus, the aim of this study was to determine the frequency of OBI in Mexican HIV-infected patients and to identify mutations in the HBV S gene that could be associated to the development of OBI. MATERIALS AND METHODS: Plasma samples from 50 HIV-infected patients with undetectable levels of the HBsAg were obtained and analyzed. The Core, PreS and S genes were amplified by nested PCR and sequenced by the Sanger method. To analyze HBV diversity in the OBI-positive patients, ten sequences of 762bp from the HBV S gene were selected, cloned, and subsequently sequenced for mutational analyses. RESULTS: OBI infection was found with a frequency of 36% (18/50). All the HBV sequences corresponded to the H genotype. The most common mutations were: C19Y, Q129H, E164D, and I195M, with a frequency of 44%, 36%, 39% and 48% respectively. CONCLUSIONS: In this study, we report the presence of OBI in a cohort of Mexican HIV-infected patients with an overall prevalence of 36%. Mutational analyses revealed that four non-silent mutations were frequent in different regions of the HBsAg gene, suggesting that they might be associated to the development of OBI in this population, nevertheless, further studies are required to determine their role in the pathogenesis of OBI.

Variation in the cuticular hydrocarbons of the Mexican fruit fly Anastrepha ludens males between strains and age classes.

In this study cuticular hydrocarbons (CHCs) were characterized from wings of individual unmated males of different Anastrepha ludens (Loew) mass-reared strains of different ages (3 and 19-day-old): (a) a standard mass-reared colony (control), (b) a genetic sexing strain, (c) a selected strain, (d) a hybrid strain, and (e) wild males. We found that the hydrocarbon profiles in all males included two n-alkanes, five monomethyl alkanes, and two alkenes. CHCs ranged from C26 to C31 . The most prominent peaks were 2-methyloctacosane (2-Me-C28), n-nonacosene (C29:1), 2-methyltriacontane (2-Me-C30), and n-hentriacontene (C31:1). Significant variations in the CHC amounts of the mass-reared strains were observed from Day 9 and thereafter. Comparison of CHCs using multivariate and canonical analyses across ages and among mass-reared strains and wild males revealed qualitative and quantitative differences. The relative amounts of C29:1 and 2-Me-C30 were significantly higher across age groups in the mass-reared strains than those in the wild males. In contrast, amounts of n-nonacosane (C29) significantly increased in wild males as they aged. Through statistical analyses, we inferred that CHC amounts vary with age. Wild males differed significantly from the mass-reared strains in the amount of C29, and the genetic sexing strain Tap-7 had significantly higher values for 2-methylhexacosane (2-Me-C26). In contrast the selected and control strain differed from the other strains in amounts of C29:1 and 2-Me-C30. We suggest that differential profiles in hydrocarbon composition among the strains may be mainly due to environmental pressures.

Bacillus subtilis with endocellulase and exocellulase activities isolated in the thermophilic phase from composting with coffee residues.

The goal of this study was to isolate, select and characterize bacteria with cellulolytic activity from two different coffee residue composting piles, one of which had an internal temperature of 57°C and pH 5.5 and the other, a temperature of 61°C, and pH 9.3. Culture media were manipulated with carboxymethylcellulose and crystalline cellulose as sole carbon sources. The enzyme activity was assessed by hydrolysis halo formation, reducing sugar production and zymograms. Three out of twenty isolated strains showed higher enzymatic activity and were identified as Bacillus subtilis according to their morphological, physiological, biochemical characteristics and based on the sequence analysis of 16S rDNA regions. The enzymatic extracts of the three selected strains showed exocellulase and endocellulase maximum activity of 0.254 and 0.519 U/ml, respectively; the activity of these enzymes was maintained even in acid pH (4.8) and basic (9.3) and at temperatures of up to 60°C. The enzymatic activities observed in this study are within the highest reported for cellulose produced by bacteria of the genus Bacillus. Endocellulase activity was shown in the zymograms from 24h until 144h of incubation. Furthermore, the pH effect on the endocellulase activity is reported for the first time by zymograms. The findings in this study entail the possibility to use these enzymes in the procurement of fermentable substrates for the production of energy from the large amount of residues generated by the coffee agroindustry.

[Ligninolytic enzyme production by white rot fungi during paraquat (herbicide) degradation]. / Producción de enzimas ligninolíticas durante la degradación del herbicida paraquat por hongos de la pudrición blanca.

Paraquat is a widely used herbicide in agriculture. Its inappropriate use and wide distribution represents a serious pollution problem for soil and water. White rot fungi are capable of degrading pollutants having a similar structure to that of lignin, such as paraquat. This study evaluated the degradation effect of paraquat on the production of ligninolytic enzymes by white rot fungi isolated from the South of Mexico. Six fungal strains showed tolerance to the herbicide in solid culture. Three of the six evaluated strains showed levels of degradation of 32, 26 and 47% (Polyporus tricholoma, Cilindrobasidium laeve and Deconica citrispora, respectively) after twelve days of cultivation in the presence of the xenobiotic. An increase in laccase and manganese peroxidase (MnP) activities was detected in the strains showing the highest percentage of degradation. Experiments were done with enzyme extracts from the extracellular medium with the two strains showing more degradation potential and enzyme production. After 24hours of incubation, a degradation of 49% of the initial paraquat concentration was observed for D. citrispora. These results suggest that paraquat degradation can be attributed to the presence of extracellular enzymes from white rot fungi. In this work the first evidence of the biodegradation potential of D. citrispora and Cilindrobasidium leave is shown.

Proteomic and morphometric study of the in vitro interaction between Oncidium sphacelatum Lindl. (Orchidaceae) and Thanatephorus sp. RG26 (Ceratobasidiaceae).

Orchidaceae establish symbiotic relationships with fungi in the Rhizoctonia group, resulting in interactions beneficial to both organisms or in cell destruction in one of them (pathogenicity). Previous studies have focused mostly on terrestrial species with a few, preliminary studies, on epiphytes. To further our understanding of the molecular mechanisms involved in these symbioses, we evaluated the interaction between Oncidium sphacelatum Lindl. and the mycorrhizal fungus Thanatephorus sp. strain RG26 (isolated from a different orchid species) in vitro using morphometric and proteomic analyses. Evidence from the morphometric and microscopic analysis showed that the fungus promoted linear growth and differentiation of orchid protocorms during 98 days interaction. On day 63, protocorm development was evident, so we analyzed the physiological response of both organisms at that moment. Proteome results suggest that orchid development stimulated by the fungus apparently involves cell cycle proteins, purine recycling, ribosome biogenesis, energy metabolism, and secretion that were up-regulated in the orchid; whereas in the fungus, a high expression of proteins implicated in stress response, protein-protein interaction, and saccharides and protein biosynthesis were found in the symbiotic interaction. This is the first work reporting proteins differentially expressed in the epiphytic orchid-fungus interaction and will contribute to the search for molecular markers that will facilitate the study of this symbiosis in both wild orchids and those in danger of extinction.

Antifungal performance of extracellular chitinases and culture supernatants of Streptomyces galilaeus CFFSUR-B12 against Mycosphaerella fijiensis Morelet.

The tropical and mycoparasite strain Streptomyces galilaeus CFFSUR-B12 was evaluated as an antagonist of Mycosphaerella fijiensis Morelet, causal agent of the Black Sigatoka Disease (BSD) of banana. On zymograms of CFFSUR-B12 culture supernatants, we detected four chitinases of approximately 32 kDa (Chi32), 20 kDa (Chi20), and two with masses well over 170 kDa (ChiU) that showed little migration during denaturing electrophoresis at different concentrations of polyacrylamide. The thymol-sulphuric acid assay showed that the ChiU were glycosylated chitinases. Moreover, matrix assisted laser desorption ionization time-of-flight MS analysis revealed that the ChiU are the same protein and identical to a family 18 chitinase from Streptomyces sp. S4 (gi|498328075). Chi32 was similar to an extracellular protein from Streptomyces albus J1074 (gi|478687481) and Chi20 was non-significantly similar to chitinases from five different strains of Streptomyces (P > 0.05). Subsequently, Chi32 and Chi20 were partially purified by anion exchange and hydrophobic interaction chromatography and tested against M. fijiensis. Chitinases failed to inhibit ascospore germination, but inhibited up to 35 and 62% of germ tube elongation and mycelial growth, respectively. We found that crude culture supernatant and living cells of S. galilaeus CFFSUR-B12 were the most effective in inhibiting M. fijiensis and are potential biocontrol agents of BSD.

[Clinical skills of Chilean general practitioners for the management of depressive disorders]. / Habilidades clínicas para el manejo de trastornos depresivos en médicos generales en Santiago de Chile.

BACKGROUND: Diverse and sustained efforts have been developed to improve the management of depression by general practitioners (GPs), but they have not improved treatment coverage and quality of services. AIM: To explore the level of knowledge and clinical skills to diagnose and treat depression by GPs in Primary Health Care (PHC) in the Metropolitan Area of Santiago de Chile (RM). MATERIAL AND METHODS: Theoretical knowledge (TK), diagnostic skills (DS) and treatment skills (TS) were evaluated in 56 GPs of the RM with a battery of specially designed instruments. RESULTS: In TK there were significant differences between GPs aged 31 years or less and their older counterparts and between Chilean and foreign doctors. Five percent of observed differences in TK were explained by age and nationality, respectively. Chilean GPs achieved higher scores in recognition of symptoms (RS), one of the dimensions of DS. No significant differences by age or nationality were observed for DS and TS. CONCLUSIONS: Achievement of GPs on tests measuring TK, DS, and TS was generally below 50%. This deficiency should be improved.

Reexamining Nonlinear Structural Equation Modeling Procedures: The Effect of Parallel and Congeneric Measures.

The current study examines the performance of the extended unconstrained approach (EXUC) and the latent moderated structural equation modeling procedure (LMS) in situations where quadratic and interaction terms are tested simultaneously and investigates their limitations with regard to the employment of parallel and congeneric measures, relatively low indicator reliabilities, and relatively large numbers of indicators. By means of a Monte Carlo study, we found LMS to be the best option for testing multiple nonlinear effects given sufficient sample size (n ≥ 500) and normally distributed exogenous variables. Its advantages became more prominent when indicator reliabilities were heterogeneous and small. The EXUC was a viable option for estimating the model when indicators were parallel and exhibited large indicator reliabilities. An empirical example of the results is provided, and the relevance of measurement model characteristics to assess nonlinear relationships is discussed.

Potentiation of the synergistic activities of chitinases ChiA, ChiB and ChiC from Serratia marcescens CFFSUR-B2 by chitobiase (Chb) and chitin binding protein (CBP).

With the goal of understanding the chitinolytic mechanism of the potential biological control strain Serratia marcescens CFFSUR-B2, genes encoding chitinases ChiA, ChiB and ChiC, chitobiase (Chb) and chitin binding protein (CBP) were cloned, the protein products overexpressed in Escherichia coli as 6His-Sumo fusion proteins and purified by affinity chromatography. Following affinity tag removal, the chitinolytic activity of the recombinant proteins was evaluated individually and in combination using colloidal chitin as substrate. ChiB and ChiC were highly active while ChiA was inactive. Reactions containing both ChiB and ChiC showed significantly increased N-acetylglucosamine trimer and dimer formation, but decreased monomer formation, compared to reactions with either enzyme alone. This suggests that while both ChiB and ChiC have a general affinity for the same substrate, they attack different sites and together degrade chitin more efficiently than either enzyme separately. Chb and CBP in combination with ChiB and ChiC (individually or together) increased their chitinase activity. We report for the first time the potentiating effect of Chb on the activity of the chitinases and the synergistic activity of a mixture of all five proteins (the three chitinases, Chb and CBP). These results contribute to our understanding of the mechanism of action of the chitinases produced by strain CFFSUR-B2 and provide a molecular basis for its high potential as a biocontrol agent against fungal pathogens.

Occult Hepatitis B Virus Infection in Hepatic Diseases and Its Significance for the WHO's Elimination Plan of Viral Hepatitis.

Liver damage can progress through different stages, resulting in cirrhosis or hepatocellular carcinoma (HCC), conditions that are often associated with viral infections. Globally, 42% and 21% of cirrhosis cases correlate with HBV and HCV, respectively. In the Americas, the prevalence ranges from 1% to 44%. The WHO has the goal to eliminate viral hepatitis, but it is important to consider occult HBV infection (OBI), a clinical condition characterized by the presence of HBV genomes despite negative surface antigen tests. This review aims to provide an overview of recent data on OBI, focusing on its role in the development of hepatic diseases and its significance in the WHO Viral Hepatitis Elimination Plan. Specific HBV gene mutations have been linked to HCC and other liver diseases. Factors related to the interactions between OBI and mutated viral proteins, which induce endoplasmic reticulum stress and oxidative DNA damage, and the potential role of HBV integration sites (such as the TERT promoter) have been identified in HCC/OBI patients. Health initiatives for OBI research in Latin American countries are crucial to achieving the WHO's goal of eradicating viral hepatitis by 2030, given the difficulty in diagnosing OBI and its unclear association with hepatic diseases.

Unlocking cellular traffic jams: olive oil-mediated rescue of CNG mutant channels.

One of the reasons to suggest olive oil consumption for a healthy life is its potential to induce robust lipidomic remodeling through membrane modification by dietary lipids. This remodeling might, in turn, modulate essential lipid-protein interactions while maintaining accurate transmembrane protein/domain orientation. Oleic acid, the primary compound in olive oil, has been suggested as a modulator of ion channel function. In this study, we explored whether this lipid could rescue the trafficking of mutated transmembrane proteins. In our initial approach, we supplemented the cell culture medium of HEK-293 cells expressing cyclic nucleotide channels tagged using green fluorescent protein (CNG-GFP) with olive oil or oleic acid. In addition to wild-type channels, we also expressed R272Q and R278W mutant channels, two non-functional intracellularly retained channels related to retinopathies. We used fluorescence microscopy and patch-clamp in the inside-out configuration to assess changes in the cell localization and function of the tested channels. Our results demonstrated that olive oil and oleic acid facilitated the transport of cyclic nucleotide-gated R272Q mutant channels towards the plasma membrane, rendering them electrophysiologically functional. Thus, our findings reveal a novel property of olive oil as a membrane protein traffic inductor.

Cupiennius spiders (Trechaleidae) from southern Mexico: DNA barcoding, venomics, and biological effect.

Background: Members of the genus Cupiennius Simon, 1891 are categorized as wandering spiders and are part of the family Trechaleidae. The genomics and proteomics of Cupiennius spiders from North America remain uncharacterized. The present study explores for the first time molecular data from the endemic species Cupiennius chiapanensis Medina, 2006, and also presents new data for Cupiennius salei (Keyserling, 1878), both collected in southern Mexico. Methods: In total, 88 Cupiennius specimens were collected from southern Mexico and morphologically identified. DNA was extracted and the mitochondrial COI fragment was amplified. COI sequences were analyzed, and a phylogenetic tree was inferred for species from the Americas. Genetic diversity was analyzed using haplotype networks and gene distances. Venom was obtained from C. chiapanensis and C. salei by electrostimulation. The venom was separated by HPLC, visualized using SDS-PAGE, and quantified for use in toxicity bioassays in mice and insects. Results: Analysis of COI sequences from C. chiapanensis showed 94% identity with C. salei, while C. salei exhibited 94-97% identity with sequences from Central and South American conspecifics. The venom from C. chiapanensis exhibited toxic activity against crickets. Venoms from C. chiapanensis and C. salei caused death in Anastrepha obliqua flies. Analysis of venom fractions from C. salei and C. chiapanensis revealed molecular masses of a similar size as some previously reported toxins and neurotoxic components. We determined the amino acid sequences of ChiaTx1 and ChiaTx2, toxins that are reported here for the first time and which showed toxicity against mice and insects. Conclusion: Our work is the first to report COI-based DNA barcoding sequences from southern Mexican Cupiennius spiders. Compounds with toxic activity were identified in venom from both species.

Inequalities by sex on remaining teeth in adults: A decomposition analysis.

OBJECTIVE: To identify which social determinants of health explain the gap in the remaining teeth between men and women. METHODS: A secondary analysis of data from the Chilean National Health Survey (CNHS) 2016-2017 was performed on the number of remaining teeth in adults. The explanatory variables were organized into structural and intermediate social determinants of health according to the WHO framework. The contribution of both groups and the contribution of each individual explanatory variable to the remaining teeth gap was estimated using the Blinder-Oaxaca decomposition analysis. RESULTS: The predicted average number of remaining teeth for men was 23.4 and 21.0 for women, thus a mean difference of 2.4 teeth. 49.8% of the inequality between men and women was due to the different distribution (endowments) of the predictors in the model. Among them, structural determinants of health, namely education level (15.8%) and employment status (17.8%), contributed the most. Intermediate determinants had no relevant contribution to explain the gap. CONCLUSIONS: Results revealed that the difference in the mean number of remaining teeth between men and women was mainly explained by two structural determinants: education level and employment status. The lack of explanatory power of intermediate determinants and the large explanatory power of structural determinants means that tackling oral health inequity in Chile requires strong political commitment. The role of intersectoral and intersectional public policies to address gender inequalities in oral health in Chile is discussed.

Transcriptome analysis of the spider Phonotimpus pennimani reveals novel toxin transcripts.

Background: Phonotimpus pennimani (Araneae, Phrurolithidae) is a small-sized (3-5 mm) spider endemic to the Tacaná volcano in Chiapas, Mexico, where it is found in soil litter of cloud forests and coffee plantations. Its venom composition has so far not been investigated, partly because it is not a species of medical significance. However, it does have an important impact on the arthropod populations of its natural habitat. Methods: Specimens were collected in Southeastern Mexico (Chiapas) and identified taxonomically by morphological characteristics. A partial sequence from the mitochondrial gene coxI was amplified. Sequencing on the Illumina platform of a transcriptome library constructed from 12 adult specimens revealed 25 toxin or toxin-like genes. Transcripts were validated (RT-qPCR) by assessing the differential expression of the toxin-like PpenTox1 transcript and normalising with housekeeping genes. Results: Analysis of the coxI-gene revealed a similarity to other species of the family Phrurolithidae. Transcriptome analysis also revealed similarity with venom components of species from the families Ctenidae, Lycosidae, and Sicariidae. Expression of the toxin-like PpenTox1 gene was different for each developmental stage (juvenile or adult) and also for both sexes (female or male). Additionally, a partial sequence was obtained for the toxin-like PpenTox1 from DNA. Conclusion: Data from the amplification of the mitochondrial coxI gene confirmed that P. pennimani belongs to the family Phrurolithidae. New genes and transcripts coding for venom components were identified.

Broad-Spectrum Antifungal, Biosurfactants and Bioemulsifier Activity of Bacillus subtilis subsp. spizizenii-A Potential Biocontrol and Bioremediation Agent in Agriculture.

In this study, the antifungal, biosurfactant and bioemulsifying activity of the lipopeptides produced by the marine bacterium Bacillus subtilis subsp. spizizenii MC6B-22 is presented. The kinetics showed that at 84 h, the highest yield of lipopeptides (556 mg/mL) with antifungal, biosurfactant, bioemulsifying and hemolytic activity was detected, finding a relationship with the sporulation of the bacteria. Based on the hemolytic activity, bio-guided purification methods were used to obtain the lipopeptide. By TLC, HPLC and MALDI-TOF, the mycosubtilin was identified as the main lipopeptide, and it was further confirmed by NRPS gene clusters prediction based on the strain's genome sequence, in addition to other genes related to antimicrobial activity. The lipopeptide showed a broad-spectrum activity against ten phytopathogens of tropical crops at a minimum inhibitory concentration of 400 to 25 µg/mL and with a fungicidal mode of action. In addition, it exhibited that biosurfactant and bioemulsifying activities remain stable over a wide range of salinity and pH and it can emulsify different hydrophobic substrates. These results demonstrate the potential of the MC6B-22 strain as a biocontrol agent for agriculture and its application in bioremediation and other biotechnological fields.

Production of prodigiosin and chitinases by tropical Serratia marcescens strains with potential to control plant pathogens.

The potential of three Serratia marcescens strains (CFFSUR-B2, CFFSUR-B3 and CFFSUR-B4) isolated from tropical regions in Mexico to inhibit the mycelial growth and conidial germination of Colletotrichum gloeosporioides, causal agent of fruit anthracnose, was evaluated. The ability of these strains to produce prodigiosin and chitinases when cultivated in oil seed-based media (peanut, sesame, soybean and castor bean) and in Luria-Bertani medium was determined. All of the strains exhibited similar fungal antagonistic activities and inhibited myceliar growth by more than 40% while inhibiting conidial germination by 81-89% (P = 0.01). The highest level of prodigiosin (40 µg/ml) was produced in the peanut-based medium while growth in soybean-based medium allowed the highest production of chitinases (56 units/ml), independent of the strain used. Strain CFFSUR-B2 grown in peanut medium was used to evaluate the effect of inoculum density and initial pH on metabolite production. The amount of prodigiosin produced increased with greater inoculum densities, with an initial density of 1 × 10(12) resulting in the highest production (60 µg/ml). Prodigiosin production was not affected by pH. The strains studied have the advantage of being adapted to tropical climates and are able to produce chitinases in the absence of chitin induction in vitro. These characteristics suggest their potential as biocontrol agents for fungal pathogens in tropical regions of the world.

Effect of a Probiotic-Enriched Diet on Sexual Competitiveness, Pheromone Emission, and Cuticular Hydrocarbons of Sterile and Fertile Anastrepha ludens (Diptera: Tephritidae).

The sterile insect technique has been used for the eradication or control of numerous tephritid fruit flies. However, mass-rearing and sterilization can affect the microbiota and sexual performance of male tephritid fruit flies. Despite the addition of postteneral protein food which contributes to the enhancement of the sexual performance of mass-reared males, in some cases, they are less competitive than their wild counterparts. Alternatively, the addition of probiotics may improve the sexual performance of mass-reared sterile males. In this study, we evaluated the effect of a postteneral Lactobacillus casei-enriched diet on the sexual competitivity, pheromone emission, and cuticular hydrocarbons of mass-reared sterile and fertile Anastrepha ludens (Loew) (Diptera: Tephritidae) males. Flies were fed either with sugar, standard diet (sugar and protein, 3:1), sugar + probiotic, or standard diet + probiotic. The addition of the probiotic improved the sexual competitivity of fertile and sterile males that were devoid of protein but led to a negative effect on males fed with a standard diet. As compared to males that were fed with the standard diet + probiotic/only sugar, the males fed with the standard diet or those fed on sugar + probiotic displayed a higher number of mating instances. Sterile males that fed on sugar + probiotic had a higher relative amount of anastrephine, epianastrephine, n-methyl octacosane, and 2-methyl triacontane than those fed on sugar only. Overall, these compounds were common in the treatments where males had the best sexual performance. Our results suggest that the probiotics offer nutritional advantages to males whose food lacks protein.