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1.
PLoS Negl Trop Dis ; 15(1): e0008812, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33497377

RESUMO

BACKGROUND: An effective syphilis vaccine should elicit antibodies to Treponema pallidum subsp. pallidum (T. p. pallidum) surface antigens to induce pathogen clearance through opsonophagocytosis. Although the combination of bioinformatics, structural, and functional analyses of T. p. pallidum genes to identify putative outer membrane proteins (OMPs) resulted in a list of potential vaccine candidates, still very little is known about whether and how transcription of these genes is regulated during infection. This knowledge gap is a limitation to vaccine design, as immunity generated to an antigen that can be down-regulated or even silenced at the transcriptional level without affecting virulence would not induce clearance of the pathogen, hence allowing disease progression. PRINCIPAL FINDINGS: We report here that tp1031, the T. p. pallidum gene encoding the putative OMP and vaccine candidate TprL is differentially expressed in several T. p. pallidum strains, suggesting transcriptional regulation. Experimental identification of the tprL transcriptional start site revealed that a homopolymeric G sequence of varying length resides within the tprL promoter and that its length affects promoter activity compatible with phase variation. Conversely, in the closely related pathogen T. p. subsp. pertenue, the agent of yaws, where a naturally-occurring deletion has eliminated the tprL promoter region, elements necessary for protein synthesis, and part of the gene ORF, tprL transcription level are negligible compared to T. p. pallidum strains. Accordingly, the humoral response to TprL is absent in yaws-infected laboratory animals and patients compared to syphilis-infected subjects. CONCLUSION: The ability of T. p. pallidum to stochastically vary tprL expression should be considered in any vaccine development effort that includes this antigen. The role of phase variation in contributing to T. p. pallidum antigenic diversity should be further studied.

2.
Sci Total Environ ; 754: 141970, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32920387

RESUMO

Integrating a network perspective into multiple-stressor research can reveal indirect stressor effects and simultaneously estimate both taxonomic and functional community characteristics, thus representing a novel approach to stressor paradigms in rivers. Using six years of data from twelve streams of Columbus, Ohio, USA, the effects of nutrients (N:P), impervious surface (%IS), and sedimentation on network properties were quantified. Variability in the strength and distribution of trophic interactions was assessed by incorporating biomass into networks. All stressors impacted some properties of network topology - linkage density (average number of links per species), connectance (fraction of all possible links realized in a network), and compartmentalization (degree to which networks contain discrete sub-webs), including synergistic interactive effects between sedimentation and stream size. We also found support for antagonistic effects between (1) sedimentation and %IS and between %IS and N:P on the weighted index mean link weight, which represents the magnitude of trophic interactions among species in a network, and (2) %IS and stream size on strength standard deviation, a measure of the distribution of total magnitude of all trophic interactions per species in a network. Overall, our results point to the potential for urban stressors such as impervious surfaces and sedimentation - alone and as interactions - to decrease network complexity, compartmentalization, and stability, likely through homogenizing habitat and limiting food resources. The observation that larger streams often buffered the negative effects of these stressors suggests that restoration and other management approaches might be most beneficial in smaller headwater streams of urban catchments.


Assuntos
Peixes , Rios , Animais , Ecossistema , Ohio
4.
BMC Genet ; 21(Suppl 2): 134, 2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33339513

RESUMO

BACKGROUND: Area-wide integrated pest management programs (AW-IPM) incorporating sterile insect technique (SIT) have been successful in suppressing populations of different fruit fly species during the last six decades. In addition, the development of genetic sexing strains (GSS) for different fruit fly species has allowed for sterile male-only releases and has significantly improved the efficacy and cost effectiveness of the SIT applications. The South American Fruit Fly Anastrepha fraterculus (Diptera: Tephritidae) is a major agricultural pest attacking several fruit commodities. This impedes international trade and has a significant negative impact on the local economies. Given the importance of sterile male-only releases, the development of a GSS for A. fraterculus would facilitate the implementation of an efficient and cost-effective SIT operational program against this insect pest species. RESULTS: For potential use in a GSS, three new morphological markers (mutants) were isolated in a laboratory strain of A. fraterculus sp. 1, including the black pupae (bp) gene located on chromosome VI. The black pupa phenotype was used as a selectable marker to develop genetic sexing strains by linking the wild type allele (bp+) to the Y-chromosome -via irradiation to induce a reciprocal Y-autosome translocation. Four GSS were established and one of them, namely GSS-89, showed the best genetic stability and the highest fertility. This strain was selected for further characterization and cytogenetic analysis. CONCLUSIONS: We herein report the development of the first genetic sexing strain of a major agricultural pest, A. fraterculus sp. 1, using as a selectable marker the black pupae genetic locus.

5.
Rev Panam Salud Publica ; 44: e130, 2020.
Artigo em Espanhol | MEDLINE | ID: mdl-33165370

RESUMO

The Health Equity Network of the Americas (HENA) is a multidisciplinary network that promotes knowledge sharing and intersectoral action for equity in health and human rights in the Americas. The objectives of HENA are: 1) to share successful experiences in the development of interventions, considering the social determinants and determination of health, to achieve participatory and community-based health responses; 2) to analyze the health, social, political, environmental and economic impacts of the COVID-19 pandemic; 3) to identify the effects of pandemic care on populations most at risk because of their age and pre-existing health conditions; 4) examine the situation at borders and population movements in the spread of the pandemic and its effects on migrant populations; 5) propose strategies to ensure access to comprehensive care for pregnant women in order to reduce maternal and neonatal suffering, morbidity, and mortality; and 6) analyze violations of human rights and the right to health of historically marginalized populations, including street dwellers and other communities that depend on public spaces and the street for survival. The analytical and intervention models for health equity at HENA are based on various approaches, including social medicine, social epidemiology, medical anthropology, human ecology, and One health.

6.
J Econ Entomol ; 113(6): 2688-2694, 2020 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-33020821

RESUMO

The genetic sexing strain (GSS) of the Mediterranean fruit fly (Ceratitis capitata (Wiedemann)) Vienna 8D53- is based on a male-linked translocation system and uses two selectable markers for male-only production, the white pupae (wp) and the temperature sensitivity lethal (tsl) genes. In this GSS, males emerge from brown pupae and are resistant to high temperatures while females emerge from white pupae, are sensitive to high temperatures. However, double homozygous females (wp tsl/wp tsl) exhibit a slower development rate compared to heterozygous males (wp+tsl+/wp tsl) during the larval stage, which was attributed to the pleiotropic effects of the tsl gene. We present the first evidence that this slower development is due to a different gene, here namely slow development (sd), which is closely linked to the tsl gene. Taking advantage of recombination phenomena between the two loci, we report the isolation of a novel temperature sensitivity lethal strain using the wp mutation as a morphological marker, which showed faster development (wp tsl FD) during the larval stage and increased in its temperature sensitivity compared with the normal tsl strain. Moreover, the introgression of this novel wp tsl FD combined trait into the Vienna 8D53- GSS, resulted in a novel Vienna 8D53- FD GSS, where females showed differences in the thermal sensibility, larval development speed, and productivity profiles. The modification of these traits and their impact on the mass rearing of the GSS for sterile insect technique applications are discussed.

7.
Artigo em Espanhol | PAHO-IRIS | ID: phr-52947

RESUMO

[RESUMEN]. La Red de las Américas para la Equidad en Salud (RAES) es una red multidisciplinaria que promueve el intercambio de conocimientos y la acción intersectorial para la equidad en salud y los derechos humanos en las Américas. Los objetivos de la RAES consisten en: 1) compartir experiencias exitosas en el desarrollo de intervenciones, considerando la determinación y los determinantes sociales, para lograr respuestas participativas y comunitarias en salud; 2) analizar los impactos sanitarios, sociales, políticos, ambientales y económicos de la pandemia de COVID-19; 3) identificar los efectos de la atención de la pandemia en las poblaciones de mayor riesgo por su edad y las condiciones de salud preexistentes; 4) examinar la situación de las fronteras y de los movimientos de población en la propagación de la pandemia y de sus efectos en las poblaciones migrantes; 5) proponer estrategias para asegurar el acceso a la atención integral de las mujeres gestantes, con el fin de reducir el sufrimiento, la morbilidad y la mortalidad materna y neonatal; y 6) analizar vulneraciones de derechos humanos y del derecho a la salud de poblaciones históricamente marginalizadas, incluyendo habitantes en situación de calle y otras comunidades que dependen de los espacios públicos y de la calle para sobrevivir. Los modelos analíticos y de intervención para la equidad en salud de la RAES se desarrollan desde varios enfoques, como la medicina social, la epidemiologia social, la antropología médica, la ecología humana y el de Una salud.


[ABSTRACT]. The Health Equity Network of the Americas (HENA) is a multidisciplinary network that promotes knowledge sharing and intersectoral action for equity in health and human rights in the Americas. The objectives of HENA are: 1) to share successful experiences in the development of interventions, considering the social determinants and determination of health, to achieve participatory and community-based health responses; 2) to analyze the health, social, political, environmental and economic impacts of the COVID-19 pandemic; 3) to identify the effects of pandemic care on populations most at risk because of their age and pre-existing health conditions; 4) examine the situation at borders and population movements in the spread of the pandemic and its effects on migrant populations; 5) propose strategies to ensure access to comprehensive care for pregnant women in order to reduce maternal and neonatal suffering, morbidity, and mortality; and 6) analyze violations of human rights and the right to health of historically marginalized populations, including street dwellers and other communities that depend on public spaces and the street for survival. The analytical and intervention models for health equity at HENA are based on various approaches, including social medicine, social epidemiology, medical anthropology, human ecology, and One health.


Assuntos
Equidade em Saúde , Saúde Única , Colaboração Intersetorial , Determinantes Sociais da Saúde , América , Equidade em Saúde , Saúde Única , Colaboração Intersetorial , Determinantes Sociais da Saúde , América
8.
BMC Infect Dis ; 20(1): 444, 2020 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-32576149

RESUMO

BACKGROUND: The syphilis epidemic continues to cause substantial morbidity and mortality worldwide, particularly in low- and middle-income countries, despite several recent disease control initiatives. Though our understanding of the pathogenesis of this disease and the biology of the syphilis agent, Treponema pallidum subsp. pallidum has improved over the last two decades, further research is necessary to improve clinical diagnosis and disease management protocols. Additionally, such research efforts could contribute to the identification of possible targets for the development of an effective vaccine to stem syphilis spread. METHODS: This study will recruit two cohorts of participants with active syphilis infection, one with de novo infection, one with repeat infection. Whole blood specimens will be collected from each study participant at baseline, 4, 12, 24, 36, and 48 weeks, to track specific markers of their immunological response, as well as to compare humoral reactivity to Treponema pallidum antigens between the two groups. Additionally, we will use serum specimens to look for unique cytokine patterns in participants with early syphilis. Oral and blood samples, as well as samples from any syphilitic lesions present, will also be collected to sequence any Treponema pallidum DNA found. DISCUSSION: By furthering our understanding of syphilis pathogenesis and human host immune response to Treponema pallidum, we will provide important data that will help in development of new point-of-care tests that could better identify active infection, leading to improved syphilis diagnosis and management. Findings could also contribute to vaccine development efforts.


Assuntos
Vacinas Bacterianas/uso terapêutico , Sífilis/epidemiologia , Sífilis/prevenção & controle , Treponema pallidum/imunologia , Vacinação , Antígenos de Bactérias/imunologia , Sequência de Bases , Estudos de Coortes , Citocinas/análise , DNA Bacteriano/genética , Seguimentos , Humanos , Tipagem Molecular , Peru/epidemiologia , Sífilis/sangue , Sífilis/imunologia , Treponema pallidum/genética
9.
Sex Transm Dis ; 47(8): 549-555, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32541611

RESUMO

BACKGROUND: The syphilis epidemic continues to cause substantial morbidity worldwide and is worsening despite ongoing control efforts. Syphilis remains an important public health problem among 3 key populations: men who have sex with men (MSM), transgender women, and female sex workers. METHODS: We conducted a retrospective chart review of patients that received rapid point-of-care treponemal antibody tests from January 2019 to July 2019 in 4 sexually transmitted infection (STI) clinics in Lima, Peru. We assessed patient medical records for human immunodeficiency virus (HIV) infection, history of STIs, as well as sociodemographic and behavioral characteristics. Cross-sectional descriptive analyses were used to determine factors associated with treponemal positivity. RESULTS: We included 401 patient records in our analyses: 252 MSM, 31 transgender women, and 118 female sex workers. The overall median age of patients was 29.0 years (interquartile range, 24.0-36.0 years). Positivity on the treponemal test was 28.9% (95% confidence interval [CI], 24.3%-33.3%) overall, 37.7% (95% CI, 31.7%-44.0%) for MSM, 54.8% (95% CI, 36.0%-72.7%) for transgender women, and 3.4% (95% CI, 0.9%-8.5%) for female sex workers. In the bivariate analysis, treponemal positivity was also associated with receptive anal sex in the last 6 months in MSM (P < 0.01). Additionally, treponemal positivity increased with age (P = 0.0212) and varied by socioeconomic status (P < 0.01). Multivariate Least Absolute Shrinkage and Selection Operator logistic regression showed that treponemal positivity was highly associated with HIV coinfection (adjusted odds ratio, 5.42) and previous STI other than HIV or syphilis (adjusted odds ratio, 1.54). CONCLUSIONS: A review of the medical records of members of 3 key populations who had recently received a rapid point-of-care treponemal test in Lima, Peru, revealed that lifetime prevalence of syphilis was high among MSM and transgender women, but low among female sex workers. Those results may indicate a need for more frequent, regular testing among MSM and transgender women-possibly in conjunction with HIV testing, and appropriate treatment of those shown to be positive.

10.
J Int AIDS Soc ; 23 Suppl 1: e25495, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32562365

RESUMO

INTRODUCTION: Among men who have sex with men (MSM) and transgender women (TW), stimulant use is high and has been associated with an increased risk of HIV infection, suicide and cardiovascular disease (CVD) mortality. We used epidemic modelling to investigate these intersecting health harms among MSM/TW in Lima, Peru and assess whether they could be mitigated by prioritizing HIV pre-exposure prophylaxis (PrEP) and harm reduction interventions among MSM/TW who use stimulants. METHODS: We adapted a dynamic model of HIV transmission among MSM/TW in Lima to incorporate stimulant use and increased HIV risk, suicide and CVD mortality. Among 6% to 24% of MSM/TW using stimulants (mostly cocaine), we modelled an increased risk of unprotected anal sex (RR = 1.35 [95%CI: 1.17 to 1.57]) obtained from local data, and increased risk of suicide (SMR = 6.26 [95%CI: 2.84 to 13.80]) and CVD (SMR = 1.83 [95%CI: 0.39 to 8.57]) mortality associated with cocaine use based on a global systematic review. We estimated the proportion of health harms occurring among MSM/TW who use stimulants in the next year (01-2020/01-2021). We also investigated the 10-year impact (01-2020/01-2030) of: (1) PrEP prioritization for stimulant-using MSM/TW compared to random allocation, and (2) integrating PrEP with a theoretical intervention halving stimulant-associated risk. RESULTS: MSM/TW in Lima will experience high HIV incidence, suicide mortality and CVD mortality (1.6/100 py, and 0.018/100 py, 0.13/100 py respectively) in 2020. Despite stimulant using MSM/TW comprising an estimated 9.5% (95%CI: 7.8 to 11.5) of all MSM/TW, in the next year, 11% 95%CI (i.e. 2.5% to 97.5% percentile) 10% to 13%) of new HIV infections, 39% (95%CI: 18% to 60%) of suicides and 15% (95%CI: 3% to 44%) of CVD deaths could occur among this group. Scaling up PrEP among all stimulant using MSM/TW could prevent 19% (95%CI: 11% to 31%) more HIV infections over 10 years compared to random allocation. Integrating PrEP and an intervention to halve stimulant-associated risks could reduce new HIV infections by 20% (95%CI: 10% to 37%), suicide deaths by 14% (95%CI: 5% to 27%) and CVD deaths by 3% (95%CI: 0% to 16%) over a decade. CONCLUSIONS: MSM/TW who use stimulants experience a disproportionate burden of health harms. Prioritizing PrEP based on stimulant use, in addition to sexual behaviour/gender identity criteria, could increase its impact. Integrated substance use, harm reduction, mental health and HIV care among MSM/TW is needed.

11.
Parasit Vectors ; 13(1): 198, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32303257

RESUMO

BACKGROUND: Radiation induced sterility is the basis of the Sterile Insect Technique, by which a target insect pest population is suppressed by releasing artificially reared sterile males of the pest species in overflooding numbers over a target site. In order for the sterile males to be of high biological quality, effective standard irradiation protocols are required. Following studies investigating the effects of mosquito pupae irradiation in water versus in air, there is a need to investigate the oxy-regulatory behavior of mosquito pupae in water to better understand the consequences of irradiation in hypoxic versus normoxic conditions. METHODS: Pupae of Aedes aegypti, Ae. albopictus, and Anopheles arabiensis were submerged in water inside air-tight 2 ml glass vials at a density of 100 pupae/ml and the dissolved oxygen (DO) levels in the water were measured and plotted over time. In addition, male pupae of Ae. aegypti (aged 40-44 h), Ae. albopictus (aged 40-44 h) and An. arabiensis (aged 20-24 h) were irradiated in a gammacell220 at increasing doses in either hypoxic (water with < 0.5% O2 content) or normoxic (in air) conditions. The males were then mated to virgin females and resulting eggs were checked for induced sterility. RESULTS: All three species depleted the water of DO to levels under 0.5% within 30 minutes, with An. arabiensis consuming oxygen the fastest at under 10 minutes. Following irradiation, the protective effect of hypoxia was observed across species and doses (P < 0.0001), increasing at higher doses. This effect was most pronounced in An. arabiensis. CONCLUSIONS: The consumption of dissolved oxygen by pupae submerged in water was significantly different between species, indicating that their oxy-regulatory capacity seems to have possibly evolved according to their preferred breeding site characteristics. This needs to be considered when sterilizing male mosquitoes at pupal stage in water. Depending on species, their DO consumption rates and their density, irradiation doses needed to achieve full sterility may vary significantly. Further assessments are required to ascertain optimal conditions in terms of ambient atmosphere during pupal irradiation to produce competitive sterile males, and temperature and density dependent effects are expected.


Assuntos
Aedes/efeitos da radiação , Anopheles/efeitos da radiação , Hipóxia , Pupa/efeitos da radiação , Esterilização/métodos , Animais , Feminino , Infertilidade Masculina , Masculino , Controle de Mosquitos/métodos , Mosquitos Vetores/efeitos da radiação , Água/química
12.
J Infect Dis ; 222(4): 690-694, 2020 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-32189000

RESUMO

To investigate the role of serum cytokine assays to distinguish between active from treated syphilis among serofast patients, we recruited individuals into a prospective cohort study. Participants underwent routine syphilis screening. We selected specimens from a majority cohort of serofast participants with treated and active syphilis. We analyzed specimens with a 62-cytokine multiplex bead-based enzyme-linked immunosorbent assay. Cytokines, brain-derived neurotrophic factor and tumor necrosis factor ß, were most predictive. We built a decision tree that was 82.4% accurate, 100% (95% confidence interval, 82%-100%) sensitive, and 45% (18%-75%) specific. Our decision tree differentiated between serum specimens from serofast participants with treated syphilis versus active syphilis.

15.
BMC Microbiol ; 19(Suppl 1): 288, 2019 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-31870292

RESUMO

BACKGROUND: Insect species have established sophisticated symbiotic associations with diverse groups of microorganisms including bacteria which have been shown to affect several aspects of their biology, physiology, ecology and evolution. In addition, recent studies have shown that insect symbionts, including those localized in the gastrointestinal tract, can be exploited for the enhancement of sterile insect technique (SIT) applications against major insect pests such as the Mediterranean fruit fly (medfly) Ceratitis capitata. We previously showed that Enterobacter sp. AA26 can be used as probiotic supplement in medfly larval diet improving the productivity and accelerating the development of the VIENNA 8 genetic sexing strain (GSS), which is currently used in large scale operational SIT programs worldwide. RESULTS: Enterobacter sp. AA26 was an adequate nutritional source for C. capitata larvae, comprising an effective substitute for brewer's yeast. Incorporating inactive bacterial cells in the larval diet conferred a number of substantial beneficial effects on medfly biology. The consumption of bacteria-based diet (either as full or partial yeast replacement) resulted in decreased immature stages mortality, accelerated immature development, increased pupal weight, and elongated the survival under stress conditions. Moreover, neither the partial nor the complete replacement of yeast with Enterobacter sp. AA26 had significant impact on adult sex ratio, females' fecundity, adults' flight ability and males' mating competitiveness. The absence of both yeast and Enterobacter sp. AA26 (deprivation of protein source and possible other important nutrients) from the larval diet detrimentally affected the larval development, survival and elongated the immature developmental duration. CONCLUSIONS: Enterobacter sp. AA26 dry biomass can fully replace the brewer's yeast as a protein source in medfly larval diet without any effect on the productivity and the biological quality of reared medfly of VIENNA 8 GSS as assessed by the FAO/IAEA/USDA standard quality control tests. We discuss this finding in the context of mass-rearing and SIT applications.


Assuntos
Ceratitis capitata/fisiologia , Enterobacter/fisiologia , Controle Biológico de Vetores/métodos , Ração Animal , Animais , Biomassa , Ceratitis capitata/microbiologia , Feminino , Masculino , Probióticos/administração & dosagem , Comportamento Sexual Animal , Simbiose
16.
Sci Rep ; 9(1): 18319, 2019 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-31797888

RESUMO

The South American fruit fly, Anastrepha fraterculus, is clearly undergoing a speciation process. Among others, two of their morphotypes, the Brazilian-1 and Peruvian, have accumulated differences in pre- and post-zygotic mechanisms resulting in a degree of reproductive isolation. Both harbor a different strain of Wolbachia, which is a widespread endosymbiotic bacterium among many invertebrates producing a range of reproductive effects. In this paper, we studied the role of this bacterium as one of the factors involved in such isolation process. Infected and cured laboratory colonies were used to test pre- and post-zygotic effects, with special emphasis in uni- and bi-directional cytoplasmic incompatibility (CI). We showed that Wolbachia is the only known reproductive symbiont present in these morphotypes. Wolbachia reduced the ability for embryonic development in crosses involving cured females and infected males within each morphotype (uni-directional CI). This inhibition showed to be more effective in the Peruvian morphotype. Bi-directional CI was not evidenced, suggesting the presence of compatible Wolbachia strains. We conclude that Wolbachia is not directly involved in the speciation process of these morphotypes. Other mechanisms rather than CI should be explored in order to explain the reduced mating compatibility between the Brazilian-1 and Peruvian morphotypes.


Assuntos
Isolamento Reprodutivo , Simbiose , Tephritidae , Wolbachia/fisiologia , Animais , Desenvolvimento Embrionário , Feminino , Especiação Genética , Masculino , Reprodução , Tephritidae/microbiologia , Tephritidae/fisiologia
17.
Insects ; 10(12)2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31842459

RESUMO

Drosophila suzukii (Diptera: Drosophilidae) is an invasive pest of a wide range of commercial soft-skinned fruits. To date, most management tactics are based on spraying of conventional and/or organic insecticides, baited traps, and netting exclusion. Interest has been expressed in using the sterile insect technique (SIT) as part of area-wide integrated pest management (AW-IPM) programs to control D. suzukii infestations. Mass-rearing protocols are one of the prerequisites for successful implementation of the SIT. To establish mass-rearing methods for this species, two different egg-collection systems were developed and compared with respect to the number of eggs produced, egg viability, pupa and adult recovery, adult emergence rate, and flight ability. Female flies kept in cages equipped with a wax panel produced significantly more eggs with higher viability and adult emergence rate, as compared to the netted oviposition system. The wax panel system was also more practical and less laborious regarding the collection of eggs. Furthermore, the wax panel oviposition system can be adapted to any size or design of an adult cage. In conclusion, this system bears great promise as an effective system for the mass production of D. suzukii for SIT.

18.
BMC Biotechnol ; 19(Suppl 2): 88, 2019 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-31847902

RESUMO

BACKGROUND: Symbiotic bacteria contribute to a multitude of important biological functions such as nutrition and reproduction and affect multiple physiological factors like fitness and longevity in their insect hosts. The melon fly, Zeugodacus cucurbitae (Coquillett), is an important agricultural pest that affects a variety of cultivated plants belonging mostly to the Cucurbitaceae family. It is considered invasive and widespread in many parts of the world. Several approaches are currently being considered for the management of its populations including the environmentally friendly and effective sterile insect technique (SIT), as a component of an integrated pest management (IPM) strategy. In the present study, we examined the effect of diet and radiation on the bacterial symbiome of Z. cucurbitae flies with the use of Next Generation Sequencing technologies. RESULTS: Melon flies were reared on two diets at the larval stage, an artificial bran-based diet and on sweet gourd, which affected significantly the development of the bacterial profiles. Significant differentiation was also observed based on gender. The effect of radiation was mostly diet dependent, with irradiated melon flies reared on the bran diet exhibiting a significant reduction in species diversity and richness compared to their non-irradiated controls. Changes in the bacterial symbiome of the irradiated melon flies included a drastic reduction in the number of sequences affiliated with members of Citrobacter, Raoultella, and Enterobacteriaceae. At the same time, an increase was observed for members of Enterobacter, Providencia and Morganella. Interestingly, the irradiated male melon flies reared on sweet gourd showed a clear differentiation compared to their non-irradiated controls, namely a significant reduction in species richness and minor differences in the relative abundance for members of Enterobacter and Providencia. CONCLUSIONS: The two diets in conjunction with the irradiation affected significantly the formation of the bacterial symbiome. Melon flies reared on the bran-based artificial diet displayed significant changes in the bacterial symbiome upon irradiation, in all aspects, including species richness, diversity and composition. When reared on sweet gourd, significant changes occurred to male samples due to radiation, only in terms of species richness.


Assuntos
Bactérias/classificação , Cucurbitaceae/parasitologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Tephritidae/microbiologia , Ração Animal , Animais , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/efeitos da radiação , Feminino , Controle de Insetos , Masculino , Filogenia , Análise de Sequência de DNA , Simbiose , Tephritidae/fisiologia
19.
BMC Biotechnol ; 19(Suppl 2): 90, 2019 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-31847833

RESUMO

BACKGROUND: Enterobacter sp. AA26 was recently isolated from the midgut of Ceratitis capitata (Wiedemann) and it was shown to have positive effects in rearing efficiency when used as larval probiotics. In this study, biomass production was carried out in bench-scale bioreactors to elucidate the biokinetic properties of Enterobacter sp. AA26 and its nutritional value. RESULTS: Strain AA26 is a psychrotolerant, halotolerant, facultatively anaerobic bacterium with broad pH range for growth (pH 4 to 10.2), which possessed the typical biochemical profile of Enterobacter spp. The specific oxygen uptake rate (SOUR) was calculated as 63.2 ± 1.26 and 121 ± 1.73 mg O2 g- 1 VSS h- 1, with the yield coefficients in acetate and glucose being equal to 0.62 ± 0.03 and 0.67 ± 0.003 g biomass produced/g substrate consumed, respectively. The maximum specific growth rate (µmax) of strain AA26 grown in fill-and-draw bioreactors at 20 °C and 35 °C was 0.035 and 0.069 h- 1, respectively. Strain AA26 grew effectively in agro-industrial wastewaters, i.e. cheese whey wastewater (CWW), as alternative substrate for replacing yeast-based media. Biomass of strain AA26 could provide all the essential amino acids and vitamins for the artificial rearing of C. capitata. Greater intracellular α- and ß-glucosidase activities were observed during growth of strain AA26 in CWW than in yeast-based substrate, although the opposite pattern was observed for the respective extracellular activities (p < 0.01). Low protease activity was exhibited in cells grown in yeast-based medium, while no lipase activities were detected. CONCLUSIONS: The ability of strain AA26 to grow in agro-industrial wastes and to provide all the essential nutrients can minimize the cost of commercial media used for mass rearing and large scale sterile insect technique applications.


Assuntos
Aminoácidos Essenciais/metabolismo , Reatores Biológicos/microbiologia , Ceratitis capitata/microbiologia , Enterobacter/crescimento & desenvolvimento , Vitaminas/metabolismo , Acetatos/metabolismo , Animais , Técnicas de Cultura Celular por Lotes , Biomassa , Ceratitis capitata/fisiologia , Enterobacter/metabolismo , Enterobacter/fisiologia , Glucose/metabolismo , Resíduos Industriais , Probióticos/administração & dosagem , Águas Residuárias/microbiologia
20.
BMC Biotechnol ; 19(Suppl 2): 96, 2019 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-31847836

RESUMO

BACKGROUND: Wolbachia pipientis is a widespread, obligatory intracellular and maternally inherited bacterium, that induces a wide range of reproductive alterations to its hosts. Cytoplasmic Incompatibility (CI) is causing embryonic lethality, the most common of them. Despite that Wolbachia-borne sterility has been proposed as an environmental friendly pest control method (Incompatible Insect Technique, IIT) since 1970s, the fact that Wolbachia modifies important fitness components of its hosts sets severe barriers to IIT implementation. Mass rearing of Mediterranean fruit fly, Ceratitis capitata (medfly), is highly optimized given that this pest is a model species regarding the implementation of another sterility based pest control method, the Sterile Insect Technique (SIT). We used the medfly-Wolbachia symbiotic association, as a model system, to study the effect of two different Wolbachia strains, on the life history traits of 2 C. capitata lines with different genomic background. RESULTS: Wolbachia effects are regulated by both C. capitata genetic background and the Wolbachia strain. Wolbachia infection reduces fertility rates in both C. capitata genetic backgrounds and shortens the pre-pupa developmental duration in the GSS strain. On the other hand, regardless of the strain of Wolbachia (wCer2, wCer4) infection does not affect either the sex ratio or the longevity of adults. wCer4 infection imposed a reduction in females' fecundity but wCer2 did not. Male mating competitiveness, adults flight ability and longevity under water and food deprivation were affected by both the genetic background of medfly and the strain of Wolbachia (genotype by genotype interaction). CONCLUSION: Wolbachia infection could alter important life history traits of mass-reared C. capitata lines and therefore the response of each genotype on the Wolbachia infection should be considered toward ensuring the productivity of the Wolbachia-infected insects under mass-rearing conditions.


Assuntos
Infecções por Anaplasmataceae/veterinária , Ceratitis capitata/fisiologia , Wolbachia/patogenicidade , Animais , Ceratitis capitata/classificação , Ceratitis capitata/genética , Ceratitis capitata/microbiologia , Feminino , Fertilidade , Genótipo , Masculino , Comportamento Sexual Animal , Simbiose , Wolbachia/classificação , Wolbachia/genética
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