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Bacterial Toxins Active against Mosquitoes: Mode of Action and Resistance. Toxins (Basel) 2021; 13:toxins13080523. [PMID: 34437394 PMCID: PMC8402332 DOI: 10.3390/toxins13080523] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/18/2021] [Accepted: 06/19/2021] [Indexed: 12/25/2022] Open
Abstract
Larvicides based on the bacteria Bacillus thuringiensis svar. israelensis (Bti) and Lysinibacillus sphaericus are effective and environmentally safe compounds for the control of dipteran insects of medical importance. They produce crystals that display specific and potent insecticidal activity against larvae. Bti crystals are composed of multiple protoxins: three from the three-domain Cry type family, which bind to different cell receptors in the midgut, and one cytolytic (Cyt1Aa) protoxin that can insert itself into the cell membrane and act as surrogate receptor of the Cry toxins. Together, those toxins display a complex mode of action that shows a low risk of resistance selection. L. sphaericus crystals contain one major binary toxin that display an outstanding persistence in field conditions, which is superior to Bti. However, the action of the Bin toxin based on its interaction with a single receptor is vulnerable for resistance selection in insects. In this review we present the most recent data on the mode of action and synergism of these toxins, resistance issues, and examples of their use worldwide. Data reported in recent years improved our understanding of the mechanism of action of these toxins, showed that their combined use can enhance their activity and counteract resistance, and reinforced their relevance for mosquito control programs in the future years.
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Rasli R, Cheong YL, Che Ibrahim MK, Farahininajua Fikri SF, Norzali RN, Nazarudin NA, Hamdan NF, Muhamed KA, Hafisool AA, Azmi RA, Ismail HA, Ali R, Ab Hamid N, Taib MZ, Omar T, Wasi Ahmad N, Lee HL. Insecticide resistance in dengue vectors from hotspots in Selangor, Malaysia. PLoS Negl Trop Dis 2021; 15:e0009205. [PMID: 33755661 PMCID: PMC7987141 DOI: 10.1371/journal.pntd.0009205] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 02/03/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND In Malaysia, dengue remains a top priority disease and usage of insecticides is the main method for dengue vector control. Limited baseline insecticide resistance data in dengue hotspots has prompted us to conduct this study. The present study reports the use of a map on the insecticide susceptibility status of Aedes aegypti and Aedes albopictus to provide a quick visualization and overview of the distribution of insecticide resistance. METHOD AND RESULTS The insecticide resistance status of Aedes populations collected from 24 dengue hotspot areas from the period of December 2018 until June 2019 was proactively monitored using the World Health Organization standard protocol for adult and larval susceptibility testing was conducted, together with elucidation of the mechanisms involved in observed resistance. For resistance monitoring, susceptibility to three adulticides (permethrin, deltamethrin, and malathion) was tested, as well as susceptibility to the larvicide, temephos. Data showed significant resistance to both deltamethrin and permethrin (pyrethroid insecticides), and to malathion (organophosphate insecticide) in all sampled Aedes aegypti populations, while variable resistance patterns were found in the sampled Aedes albopictus populations. Temephos resistance was observed when larvae were tested using the diagnostic dosage of 0.012mg/L but not at the operational dosage of 1mg/L for both species. CONCLUSION The present study highlights evidence of a potential threat to the effectiveness of insecticides currently used in dengue vector control, and the urgent requirement for insecticide resistance management to be integrated into the National Dengue Control Program.
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Affiliation(s)
- Rosilawati Rasli
- Medical Entomology Unit, Infectious Disease Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
| | - Yoon Ling Cheong
- Biomedical Epidemiology Unit, Special Resource Centre, Institute for Medical Research, Ministry of Health, Kuala Lumpur, Malaysia
| | - M. Khairuddin Che Ibrahim
- Biomedical Research, Strategic & Innovation Management Unit, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
| | - Siti Futri Farahininajua Fikri
- Medical Entomology Unit, Infectious Disease Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
| | - Rusydi Najmuddin Norzali
- Medical Entomology Unit, Infectious Disease Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
| | - Nur Ayuni Nazarudin
- Medical Entomology Unit, Infectious Disease Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
| | - Nur Fadillah Hamdan
- Medical Entomology Unit, Infectious Disease Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
| | - Khairul Asuad Muhamed
- Medical Entomology Unit, Infectious Disease Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
| | - Afiq Ahnaf Hafisool
- Medical Entomology Unit, Infectious Disease Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
| | - Ruziyatul Aznieda Azmi
- Medical Entomology Unit, Infectious Disease Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
| | - Harith Aswad Ismail
- Medical Entomology Unit, Infectious Disease Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
| | - Roziah Ali
- Medical Entomology Unit, Infectious Disease Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
| | - Nurulhusna Ab Hamid
- Medical Entomology Unit, Infectious Disease Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
| | - Mohd Zainuldin Taib
- Biomedical Museum Unit, Special Resource Centre, Institute for Medical Research, Ministry of Health, Kuala Lumpur, Malaysia
| | - Topek Omar
- Federal Territory Health Department of Kuala Lumpur and Putrajaya, Ministry of Health, Kuala Lumpur, Malaysia
| | - Nazni Wasi Ahmad
- Medical Entomology Unit, Infectious Disease Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
| | - Han Lim Lee
- Medical Entomology Unit, Infectious Disease Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health, Selangor, Malaysia
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Bharati M, Saha D. Insecticide susceptibility status and major detoxifying enzymes' activity in Aedes albopictus (Skuse), vector of dengue and chikungunya in Northern part of West Bengal, India. Acta Trop 2017; 170:112-119. [PMID: 28254583 DOI: 10.1016/j.actatropica.2017.02.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 02/13/2017] [Accepted: 02/13/2017] [Indexed: 10/20/2022]
Abstract
Mosquitoes belonging to Aedes genus, Aedes aegypti and Aedes albopictus transmit many globally important arboviruses including Dengue (DENV) and Chikungunya (CHIKV). Vector control with the use of insecticide remains the suitable method of choice to stop the transmission of these diseases. However, vector control throughout the world is failing to achieve its target results because of the worldwide development of insecticide resistance in mosquitoes. To assess the insecticide susceptibility status of Aedes albopictus from northern part of West Bengal, the susceptibility of eight different Aedes albopictus populations were tested against a commonly used larvicide (temephos) and some adulticides (malathion, deltamethrin and lambda cyhalothrin) along with the major insecticide detoxifying enzymes' activity in them. Through this study, it was revealed that most of the populations were found susceptible to temephos except Nagrakata (NGK) and Siliguri (SLG), which showed both a higher resistance ratio (RR99) and a lower susceptibility, thereby reflecting the development of resistance against temephos in them. However, all tested adulticides caused 100% mortality in all the population implying their potency in control of this mosquito in this region of India. Through the study of carboxylesterase activity, it was revealed that the NGK population showed a 9.6 fold higher level of activity than susceptible population. The same population also showed a lower level of susceptibility and a higher resistance ratio (RR99), indicating a clear correlation between susceptibility to temephos and carboxylesterase enzymes' activity in this population. This preliminary data reflects that the NGK population is showing a trend towards resistance development and with time, there is possibility that this resistance phenomenon will spread to other populations. With the recurrence of dengue and chikungunya, this data on insecticide susceptibility status of Aedes albopictus could help the authorities engaged in vector control programmes to formulate effective measures against this mosquito in this region.
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Vitorino LC, Bessa LA. Technological Microbiology: Development and Applications. Front Microbiol 2017; 8:827. [PMID: 28539920 PMCID: PMC5423913 DOI: 10.3389/fmicb.2017.00827] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/24/2017] [Indexed: 12/22/2022] Open
Abstract
Over thousands of years, modernization could be predicted for the use of microorganisms in the production of foods and beverages. However, the current accelerated pace of new food production is due to the rapid incorporation of biotechnological techniques that allow the rapid identification of new molecules and microorganisms or even the genetic improvement of known species. At no other time in history have microorganisms been so present in areas such as agriculture and medicine, except as recognized villains. Currently, however, beneficial microorganisms such as plant growth promoters and phytopathogen controllers are required by various agricultural crops, and many species are being used as biofactories of important pharmacological molecules. The use of biofactories does not end there: microorganisms have been explored for the synthesis of diverse chemicals, fuel molecules, and industrial polymers, and strains environmentally important due to their biodecomposing or biosorption capacity have gained interest in research laboratories and in industrial activities. We call this new microbiology Technological Microbiology, and we believe that complex techniques, such as heterologous expression and metabolic engineering, can be increasingly incorporated into this applied science, allowing the generation of new and improved products and services.
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Affiliation(s)
- Luciana C. Vitorino
- Laboratory of Agricultural Microbiology, Goiano Federal InstituteGoiás, Brazil
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Malik A, Yasar A, Tabinda AB, Zaheer IE, Malik K, Batool A, Mahfooz Y. Assessing spatio-temporal trend of vector breeding and dengue fever incidence in association with meteorological conditions. ENVIRONMENTAL MONITORING AND ASSESSMENT 2017; 189:189. [PMID: 28353206 DOI: 10.1007/s10661-017-5902-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 03/16/2017] [Indexed: 06/06/2023]
Abstract
Th aim of this study is to investigate spatio-temporal trends of dengue vector breeding and epidemic (disease incidence) influenced by climatic factors. The spatio-temporal (low-, medium-, and high-intensity periods) evaluation of entomological and epidemiological investigations along with climatic factors like rainfall (RF), temperature (Tmax), relative humidity (RH), and larval indexing was conducted to develop correlations in the area of Lahore, Pakistan. The vector abundance and disease transmission trend was geo-tagged for spatial insight. The sufficient rainfall events and optimum temperature and relative humidity supported dengue vector breeding with high larval indices for water-related containers (27-37%). Among temporal analysis, the high-intensity period exponentially projected disease incidence followed by post-rainfall impacts. The high larval incidence that was observed in early high-intensity periods effected the dengue incidence. The disease incidence had a strong association with RF (r = 0.940, α = 0.01). The vector larva occurrence (r = 0.017, α = 0.05) influenced the disease incidence. Similarly, RH (r = 0.674, α = 0.05) and average Tmax (r = 0.307, α = 0.05) also induced impact on the disease incidence. In this study, the vulnerability to dengue fever highly correlates with meteorological factors during high-intensity period. It provides area-specific understanding of vector behavior, key containers, and seasonal patterns of dengue vector breeding and disease transmission which is essential for preparing an effective prevention plan against the vector.
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Affiliation(s)
- Afifa Malik
- Sustainable Development Study Center, Government College University, Katchery Road, Lahore, 54000, Pakistan.
| | - Abdullah Yasar
- Sustainable Development Study Center, Government College University, Katchery Road, Lahore, 54000, Pakistan
| | - Amtul Bari Tabinda
- Sustainable Development Study Center, Government College University, Katchery Road, Lahore, 54000, Pakistan
| | - Ihsan Elahi Zaheer
- Department of Environmental Sciences and Engineering, Government College University, Allama Iqbal Road, Faisalabad, 38000, Pakistan
| | - Khalida Malik
- Department of Statistics, Government College University, Katchery Road, Lahore, 54000, Pakistan
| | - Adeeba Batool
- Sustainable Development Study Center, Government College University, Katchery Road, Lahore, 54000, Pakistan
| | - Yusra Mahfooz
- Sustainable Development Study Center, Government College University, Katchery Road, Lahore, 54000, Pakistan
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Rahim J, Ahmad AH, Kassim NFA, Ahmad H, Ishak IH, Rus AC, Maimusa HA. Revised Discriminating Lethal Doses For Resistance Monitoring Program on Aedes albopictus Against Temephos and Malathion in Penang Island, Malaysia. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2016; 32:210-216. [PMID: 27802400 DOI: 10.2987/16-6556.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Dengue vector control still heavily relies on the use of chemical insecticides, and the widespread use of insecticides has led to resistance in mosquitoes. The diagnostic dose is a key part of resistance monitoring. The present study corroborates the discriminating lethal doses of temephos and malathion based on dose-response of known susceptible strain of Aedes albopictus following the World Health Organization (WHO) diagnostic test procedure. Late 3rd and early 4th instars were tested with a range of larvicides to determine the lethal concentrations (LC50 and LC99) values. A slightly higher diagnostic dose of 0.020 mg/liter as compared with the WHO-established value of 0.012 mg/liter was observed for temephos. Meanwhile, a malathion diagnostic dose of 0.200 mg/liter is also reported here since there are no such reported values by WHO. Doubling the LC99 values of susceptible strains, 3 of the 5 wild-collected populations showed resistance to temephos and 2 showed incipient resistance; all 5 populations showed incipient resistance to malathion. The revised and established lethal diagnostic dose findings from the current work are crucial to elaborate on the variation in susceptibility of Ae. albopictus in future resistance monitoring programs in Malaysia.
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