Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-11 (of 11 Records) |
Query Trace: Dzuris N[original query] |
---|
Geographic heterogeneity in Anopheles albimanus microbiota is lost within one generation of laboratory colonization (preprint)
Dada N , Benedict AC , López F , Lol JC , Sheth M , Dzuris N , Padilla N , Lenhart A . bioRxiv 2020 2020.06.02.129619 Research on mosquito-microbe interactions may lead to new tools for mosquito and mosquito-borne disease control. To date, such research has largely utilized laboratory-reared mosquitoes that may lack the microbial diversity of wild populations. To better understand how mosquito microbiota may vary across different geographic locations and upon laboratory colonization, we characterized the microbiota of F1 progeny of wild-caught adult Anopheles albimanus from four locations in Guatemala using high throughput 16S rRNA amplicon sequencing. A total of 132 late instar larvae and 135 2-5day old, non-blood-fed virgin adult females were reared under identical laboratory conditions, pooled (3 individuals/pool) and analyzed. Larvae from mothers collected at different sites showed different microbial compositions (p=0.001; F = 9.5), but these differences were no longer present at the adult stage (p=0.12; F = 1.6). This indicates that mosquitoes retain a significant portion of their field-derived microbiota throughout immature development but shed them before or during adult eclosion. This is the first time the microbiota of F1 progeny of wild-caught mosquitoes has been characterized in relation to parental collection site, and our findings provide evidence that geographically associated heterogeneity in microbiota composition persists for a single generation, but only until the end of the larval stage. These findings advance our understanding of how the mosquito microbiota is altered upon first laboratory colonization, and raises considerations for how mosquito microbiome research may be extended beyond the laboratory to field settings.Competing Interest StatementThe authors have declared no competing interest. |
Pyrethroid exposure alters Anopheles albimanus microbiota and resistant mosquitoes harbor more insecticide-metabolizing bacteria (preprint)
Dada N , Lol JC , Benedict AC , Lopez F , Sheth M , Dzuris N , Padilla N , Lenhart A . bioRxiv 2019 537480 A deeper understanding of the mechanisms underlying insecticide resistance is needed to mitigate its threat to malaria vector control. Building upon our earlier identified associations between mosquito microbiota and insecticide resistance, we demonstrate for the first time, type-specific effects of pyrethroid exposure on internal and cuticle surface bacteria in adult progeny of field-collected Anopheles albimanus. In contrast, larval cuticle surface—but not internal—bacteria were affected by pyrethroid exposure. Being over five-folds more abundant in pyrethroid resistant adults, as compared to susceptible or non-insecticide-exposed mosquitoes, Klebsiella (alphacypermethrin), Pantoea and Asaia (permethrin) were identified as potential markers of pyrethroid resistance in An. albimanus. We also show for the first time that An. albimanus larvae and adult cuticles harbor more diverse bacterial communities than their internal microbial niches. Our findings indicate insecticide selection pressures on mosquito microbiota, and support the hypothesis of an undescribed microbe-mediated mechanism of insecticide metabolism in mosquitoes. |
Insecticide resistance levels and associated mechanisms in three Aedes aegypti populations from Venezuela
Rubio-Palis Y , Dzuris N , Sandi C , Vizcaino-Cabarrus RL , Corredor-Medina C , González JA , Lenhart AE . Mem Inst Oswaldo Cruz 2023 118 e220210 BACKGROUND: The massive use of insecticides in public health has exerted selective pressure resulting in the development of resistance in Aedes aegypti to different insecticides in Venezuela. Between 2010 and 2020, the only insecticides available for vector control were the organophosphates (Ops) fenitrothion and temephos which were focally applied. OBJECTIVES: To determine the state of insecticide resistance and to identify the possible biochemical and molecular mechanisms involved in three populations of Ae. aegypti from Venezuela. METHODS: CDC bottle bioassays were conducted on Ae. aegypti collected between October 2019 and February 2020 in two hyperendemic localities for dengue in Aragua State and in a malaria endemic area in Bolívar State. Insecticide resistance mechanisms were studied using biochemical assays and polymerase chain reaction (PCR) to detect kdr mutations. FINDINGS: Bioassays showed contrasting results among populations; Las Brisas was resistant to malathion, permethrin and deltamethrin, Urbanización 19 de Abril was resistant to permethrin and Nacupay to malathion. All populations showed significantly higher activity of mixed function oxidases and glutathione-S-transferases (GSTs) in comparison with the susceptible strain. The kdr mutations V410L, F1534C, and V1016I were detected in all populations, with F1534C at higher frequencies. MAIN CONCLUSION: Insecticide resistance persists in three Ae. aegypti populations from Venezuela even in the relative absence of insecticide application. |
Building the capacity of West African countries in Aedes surveillance: inaugural meeting of the West African Aedes Surveillance Network (WAASuN)
Dadzie SK , Akorli J , Coulibaly MB , Ahadji-Dabla KM , Baber I , Bobanga T , Boukhary Aoms , Canelas T , Facchinelli L , Gonalves A , Guelbeogo M , Kamgang B , Keita IK , Konan L , Levine R , Dzuris N , Lenhart A . Parasit Vectors 2022 15 (1) 381 Arboviral diseases such as dengue, Zika and chikungunya transmitted by Aedes mosquitoes have been reported in 34 African countries. Available data indicate that in recent years there have been dengue and chikungunya outbreaks in the West Africa subregion, in countries including Cte d'Ivoire, Burkina Faso, Gabon, Senegal, and Benin. These viral diseases are causing an increased public health burden, which impedes poverty reduction and sustainable development. Aedes surveillance and control capacity, which are key to reducing the prevalence of arboviral infections, need to be strengthened in West Africa, to provide information essential for the formulation of effective vector control strategies and the prediction of arboviral disease outbreaks. In line with these objectives, the West African Aedes Surveillance Network (WAASuN) was created in 2017 at a meeting held in Sierra Leone comprising African scientists working on Aedes mosquitoes. This manuscript describes the proceedings and discusses key highlights of the meeting. |
Comprehensive characterization of internal and cuticle surface microbiota of laboratory-reared F Anopheles albimanus originating from different sites.
Dada N , Benedict AC , López F , Lol JC , Sheth M , Dzuris N , Padilla N , Lenhart A . Malar J 2021 20 (1) 414 BACKGROUND: Research on mosquito-microbe interactions may lead to new tools for mosquito and mosquito-borne disease control. To date, such research has largely utilized laboratory-reared mosquitoes that typically lack the microbial diversity of wild populations. A logical progression in this area involves working under controlled settings using field-collected mosquitoes or, in most cases, their progeny. Thus, an understanding of how laboratory colonization affects the assemblage of mosquito microbiota would aid in advancing mosquito microbiome studies and their applications beyond laboratory settings. METHODS: Using high throughput 16S rRNA amplicon sequencing, the internal and cuticle surface microbiota of F(1) progeny of wild-caught adult Anopheles albimanus from four locations in Guatemala were characterized. A total of 132 late instar larvae and 135 2-5 day-old, non-blood-fed virgin adult females that were reared under identical laboratory conditions, were pooled (3 individuals/pool) and analysed. RESULTS: Results showed location-associated heterogeneity in both F(1) larval internal (p = 0.001; pseudo-F = 9.53) and cuticle surface (p = 0.001; pseudo-F = 8.51) microbiota, and only F(1) adult cuticle surface (p = 0.001; pseudo-F = 4.5) microbiota, with a more homogenous adult internal microbiota (p = 0.12; pseudo-F = 1.6) across collection sites. Overall, ASVs assigned to Leucobacter, Thorsellia, Chryseobacterium and uncharacterized Enterobacteriaceae, dominated F(1) larval internal microbiota, while Acidovorax, Paucibacter, and uncharacterized Comamonadaceae, dominated the larval cuticle surface. F(1) adults comprised a less diverse microbiota compared to larvae, with ASVs assigned to the genus Asaia dominating both internal and cuticle surface microbiota, and constituting at least 70% of taxa in each microbial niche. CONCLUSIONS: These results suggest that location-specific heterogeneity in filed mosquito microbiota can be transferred to F(1) progeny under normal laboratory conditions, but this may not last beyond the F(1) larval stage without adjustments to maintain field-derived microbiota. These findings provide the first comprehensive characterization of laboratory-colonized F(1) An. albimanus progeny from field-derived mothers. This provides a background for studying how parentage and environmental conditions differentially or concomitantly affect mosquito microbiome composition, and how this can be exploited in advancing mosquito microbiome studies and their applications beyond laboratory settings. |
Evaluation of the durability and use of long-lasting insecticidal nets in Nicaragua
Villalta EL , Soto Bravo AM , Vizcaino L , Dzuris N , Delgado M , Green M , Smith SC , Lenhart A , Macedo de Oliveira A . Malar J 2021 20 (1) 106 BACKGROUND: Vector control for malaria prevention relies most often on the use of insecticide-treated bed net (ITNs) and indoor residual spraying. Little is known about the longevity of long-lasting insecticidal nets (LLINs) in the Americas. The physical integrity and insecticide retention of LLINs over time were monitored after a bed net distribution campaign to assess community practices around LLIN care and use in Waspam, northeastern Nicaragua. METHODS: At least 30 nets were collected at 6, 12, 24, and 36 months post distribution. Physical integrity was measured by counting holes and classifying nets into categories (good, damaged, and too torn) depending on a proportionate hole index (pHI). Insecticide bioefficacy was assessed using cone bioassays, and insecticide content measured using a cyanopyrethroid field test (CFT). RESULTS: At 6 months, 87.3 % of LLINs were in good physical condition, while by 36 months this decreased to 20.6 %, with 38.2 % considered 'too torn.' The median pHI increased from 7 at the 6-month time point to 480.5 by 36 months. After 36 months of use, median mortality in cone bioassays was 2 % (range: 0-6 %) compared to 16 % (range: 2-70 %) at 6 months. There was a decrease in the level of deltamethrin detected on the surface of the LLINs with 100 % of tested LLINs tested at 12 months and 24 months crossing the threshold for being considered a failed net by CFT. CONCLUSIONS: This first comprehensive analysis of LLIN durability in Central America revealed rapid loss of chemical bioefficacy and progressive physical damage over a 36-month period. Use of these findings to guide future LLIN interventions in malaria elimination settings in Nicaragua, and potentially elsewhere in the Americas, could help optimize the successful implementation of vector control strategies. |
Symptom Duration and Risk Factors for Delayed Return to Usual Health Among Outpatients with COVID-19 in a Multistate Health Care Systems Network - United States, March-June 2020.
Tenforde MW , Kim SS , Lindsell CJ , Billig Rose E , Shapiro NI , Files DC , Gibbs KW , Erickson HL , Steingrub JS , Smithline HA , Gong MN , Aboodi MS , Exline MC , Henning DJ , Wilson JG , Khan A , Qadir N , Brown SM , Peltan ID , Rice TW , Hager DN , Ginde AA , Stubblefield WB , Patel MM , Self WH , Feldstein LR , IVY Network Investigators , CDC COVID-19 Response Team , Dorough Layne , Dzuris Nicole , Griggs Eric P , Kassem Ahmed M , Marcet Paula L , Ogokeh Constance E , Sciarratta Courtney N Siddula Akshita , Smith Emily R , Wu Michael J . MMWR Morb Mortal Wkly Rep 2020 69 (30) 993-998 Prolonged symptom duration and disability are common in adults hospitalized with severe coronavirus disease 2019 (COVID-19). Characterizing return to baseline health among outpatients with milder COVID-19 illness is important for understanding the full spectrum of COVID-19-associated illness and tailoring public health messaging, interventions, and policy. During April 15-June 25, 2020, telephone interviews were conducted with a random sample of adults aged ≥18 years who had a first positive reverse transcription-polymerase chain reaction (RT-PCR) test for SARS-CoV-2, the virus that causes COVID-19, at an outpatient visit at one of 14 U.S. academic health care systems in 13 states. Interviews were conducted 14-21 days after the test date. Respondents were asked about demographic characteristics, baseline chronic medical conditions, symptoms present at the time of testing, whether those symptoms had resolved by the interview date, and whether they had returned to their usual state of health at the time of interview. Among 292 respondents, 94% (274) reported experiencing one or more symptoms at the time of testing; 35% of these symptomatic respondents reported not having returned to their usual state of health by the date of the interview (median = 16 days from testing date), including 26% among those aged 18-34 years, 32% among those aged 35-49 years, and 47% among those aged ≥50 years. Among respondents reporting cough, fatigue, or shortness of breath at the time of testing, 43%, 35%, and 29%, respectively, continued to experience these symptoms at the time of the interview. These findings indicate that COVID-19 can result in prolonged illness even among persons with milder outpatient illness, including young adults. Effective public health messaging targeting these groups is warranted. Preventative measures, including social distancing, frequent handwashing, and the consistent and correct use of face coverings in public, should be strongly encouraged to slow the spread of SARS-CoV-2. |
Characteristics of Adult Outpatients and Inpatients with COVID-19 - 11 Academic Medical Centers, United States, March-May 2020.
Tenforde MW , Billig Rose E , Lindsell CJ , Shapiro NI , Files DC , Gibbs KW , Prekker ME , Steingrub JS , Smithline HA , Gong MN , Aboodi MS , Exline MC , Henning DJ , Wilson JG , Khan A , Qadir N , Stubblefield WB , Patel MM , Self WH , Feldstein LR , CDC COVID-19 Response Team , Kassem Ahmed M , Sciarratta Courtney N , Dzuris Nicole , Marcet Paula L , Siddula Akshita . MMWR Morb Mortal Wkly Rep 2020 69 (26) 841-846 Descriptions of coronavirus disease 2019 (COVID-19) in the United States have focused primarily on hospitalized patients. Reports documenting exposures to SARS-CoV-2, the virus that causes COVID-19, have generally been described within congregate settings, such as meat and poultry processing plants (1) and long-term care facilities (2). Understanding individual behaviors and demographic characteristics of patients with COVID-19 and risks for severe illness requiring hospitalization can inform efforts to reduce transmission. During April 15-May 24, 2020, telephone interviews were conducted with a random sample of adults aged >/=18 years who had positive reverse transcription-polymerase chain reaction (RT-PCR) test results for SARS-CoV-2 in outpatient and inpatient settings at 11 U.S. academic medical centers in nine states. Respondents were contacted 14-21 days after SARS-CoV-2 testing and asked about their demographic characteristics, underlying chronic conditions, symptoms experienced on the date of testing, and potential exposures to SARS-CoV-2 during the 2 weeks before illness onset (or the date of testing among those who did not report symptoms at the time of testing). Among 350 interviewed patients (271 [77%] outpatients and 79 [23%] inpatients), inpatients were older, more likely to be Hispanic and to report dyspnea than outpatients. Fewer inpatients (39%, 20 of 51) reported a return to baseline level of health at 14-21 days than did outpatients (64%, 150 of 233) (p = 0.001). Overall, approximately one half (46%) of patients reported known close contact with someone with COVID-19 during the preceding 2 weeks. This was most commonly a family member (45%) or a work colleague (34%). Approximately two thirds (64%, 212 of 333) of participants were employed; only 35 of 209 (17%) were able to telework. These findings highlight the need for screening, case investigation, contact tracing, and isolation of infected persons to control transmission of SARS-CoV-2 infection during periods of community transmission. The need for enhanced measures to ensure workplace safety, including ensuring social distancing and more widespread use of cloth face coverings, are warranted (3). |
Mosquito control activities during local transmission of Zika virus, Miami-Dade County, Florida, USA, 2016
McAllister JC , Porcelli M , Medina JM , Delorey MJ , Connelly CR , Godsey MS , Panella NA , Dzuris N , Boegler KA , Kenney JL , Kothera L , Vizcaino L , Lenhart AE , Mutebi JP , Vasquez C . Emerg Infect Dis 2020 26 (5) 881-890 In 2016, four clusters of local mosquitoborne Zika virus transmission were identified in Miami-Dade County, Florida, USA, generating "red zones" (areas into which pregnant women were advised against traveling). The Miami-Dade County Mosquito Control Division initiated intensive control activities, including property inspections, community education, and handheld sprayer applications of larvicides and adulticides. For the first time, the Mosquito Control Division used a combination of areawide ultralow-volume adulticide and low-volume larvicide spraying to effectively control Aedes aegypti mosquitoes, the primary Zika virus vector within the county. The number of mosquitoes rapidly decreased, and Zika virus transmission was interrupted within the red zones immediately after the combination of adulticide and larvicide spraying. |
Pyrethroid exposure alters internal and cuticle surface bacterial communities in Anopheles albimanus.
Dada N , Lol JC , Benedict AC , Lopez F , Sheth M , Dzuris N , Padilla N , Lenhart A . ISME J 2019 13 (10) 2447-2464 A deeper understanding of the mechanisms underlying insecticide resistance is needed to mitigate its threat to malaria vector control. Following previously identified associations between mosquito microbiota and insecticide resistance, we demonstrate for the first time, the effects of pyrethroid exposure on the microbiota of F1 progeny of field-collected Anopheles albimanus. Larval and adult mosquitoes were exposed to the pyrethroids alphacypermethrin (only adults), permethrin, and deltamethrin. While there were no significant differences in bacterial composition between insecticide-resistant and insecticide-susceptible mosquitoes, bacterial composition between insecticide-exposed and non-exposed mosquitoes was significantly different for alphacypermethrin and permethrin exposure. Along with other bacterial taxa not identified to species, Pantoea agglomerans (a known insecticide-degrading bacterial species) and Pseudomonas fragi were more abundant in insecticide-exposed compared to non-exposed adults, demonstrating that insecticide exposure can alter mosquito bacterial communities. We also show for the first time that the cuticle surfaces of both larval and adult An. albimanus harbor more diverse bacterial communities than their internal microbial niches. Together, these findings demonstrate how insecticide pressure could be selecting for certain bacteria within mosquitoes, especially insecticide-metabolizing bacteria, thus potentially contributing to insecticide resistance. |
Contrasting patterns of gene expression indicate differing pyrethroid resistance mechanisms across the range of the New World malaria vector Anopheles albimanus.
Mackenzie-Impoinvil L , Weedall GD , Lol JC , Pinto J , Vizcaino L , Dzuris N , Riveron J , Padilla N , Wondji C , Lenhart A . PLoS One 2019 14 (1) e0210586 Decades of unmanaged insecticide use and routine exposure to agrochemicals have left many populations of malaria vectors in the Americas resistant to multiple classes of insecticides, including pyrethroids. The molecular basis of pyrethroid resistance is relatively uncharacterised in American malaria vectors, preventing the design of suitable resistance management strategies. Using whole transcriptome sequencing, we characterized the mechanisms of pyrethroid resistance in Anopheles albimanus from Peru and Guatemala. An. albimanus were phenotyped as either deltamethrin or alpha-cypermethrin resistant. RNA from 1) resistant, 2) unexposed, and 3) a susceptible laboratory strain of An. albimanus was sequenced and analyzed using RNA-Seq. Expression profiles of the three groups were compared based on the current annotation of the An. albimanus reference genome. Several candidate genes associated with pyrethroid resistance in other malaria vectors were found to be overexpressed in resistant An. albimanus. In addition, gene ontology terms related to serine-type endopeptidase activity, extracellular activity and chitin metabolic process were also commonly overexpressed in the field caught resistant and unexposed samples from both Peru and Guatemala when compared to the susceptible strain. The cytochrome P450 CYP9K1 was overexpressed 14x in deltamethrin and 8x in alpha-cypermethrin-resistant samples from Peru and 2x in deltamethrin-resistant samples from Guatemala, relative to the susceptible laboratory strain. CYP6P5 was overexpressed 68x in deltamethrin-resistant samples from Peru but not in deltamethrin-resistant samples from Guatemala. When comparing overexpressed genes between deltamethrin-resistant and alpha-cypermethrin-resistant samples from Peru, a single P450 gene, CYP4C26, was overexpressed 9.8x (p<0.05) in alpha-cypermethrin-resistant samples. In Peruvian deltamethrin-resistant samples, the knockdown resistance mutation (kdr) variant alleles at position 1014 were rare, with approximately 5% frequency, but in the alpha-cypermethrin-resistant samples, the frequency of these alleles was approximately 15-30%. Functional validation of the candidate genes and the kdr mutation as a resistance marker for alpha-cypermethrin will confirm the role of these mechanisms in conferring pyrethroid resistance. |
- Page last reviewed:Feb 1, 2024
- Page last updated:May 06, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure