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Ibrahim I, Ayariga JA, Xu J, Adebanjo A, Robertson BK, Samuel-Foo M, Ajayi OS. CBD resistant Salmonella strains are susceptible to epsilon 34 phage tailspike protein. Front Med (Lausanne) 2023; 10:1075698. [PMID: 36960333 PMCID: PMC10028193 DOI: 10.3389/fmed.2023.1075698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 02/15/2023] [Indexed: 03/09/2023] Open
Abstract
The rise of antimicrobial resistance is a global public health crisis that threatens the effective control and prevention of infections. Due to the emergence of pandrug-resistant bacteria, most antibiotics have lost their efficacy. Bacteriophages or their components are known to target bacterial cell walls, cell membranes, and lipopolysaccharides (LPS) and hydrolyze them. Bacteriophages being the natural predators of pathogenic bacteria, are inevitably categorized as "human friends", thus fulfilling the adage that "the enemy of my enemy is my friend". Leveraging on their lethal capabilities against pathogenic bacteria, researchers are searching for more ways to overcome the current antibiotic resistance challenge. In this study, we expressed and purified epsilon 34 phage tailspike protein (E34 TSP) from the E34 TSP gene, then assessed the ability of this bacteriophage protein in the killing of two CBD-resistant strains of Salmonella spp. We also assessed the ability of the tailspike protein to cause bacteria membrane disruption, and dehydrogenase depletion. We observed that the combined treatment of CBD-resistant strains of Salmonella with CBD and E34 TSP showed poor killing ability whereas the monotreatment with E34 TSP showed considerably higher killing efficiency. This study demonstrates that the inhibition of the bacteria by E34 TSP was due in part to membrane disruption, and dehydrogenase inactivation by the protein. The results of this work provides an interesting background to highlight the crucial role phage protein such as E34 TSP could play in pathogenic bacterial control.
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Affiliation(s)
- Iddrisu Ibrahim
- The Microbiology Program, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL, United States
| | - Joseph Atia Ayariga
- The Industrial Hemp Program, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL, United States
- *Correspondence: Joseph Atia Ayariga,
| | - Junhuan Xu
- The Industrial Hemp Program, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL, United States
| | - Ayomide Adebanjo
- The Industrial Hemp Program, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL, United States
| | - Boakai K. Robertson
- The Microbiology Program, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL, United States
| | - Michelle Samuel-Foo
- The Industrial Hemp Program, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL, United States
| | - Olufemi S. Ajayi
- The Industrial Hemp Program, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL, United States
- Olufemi S. Ajayi,
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Chicas-Mosier AM, Balusu RR, Ajayi OS, Kafle BD, Morawo T, Mertoglu G, Smith CM, Warsi S, Fadamiro HY. Kudzu Bug (Megacopta cribraria) and Associated Egg Parasitoids Emergence Rates in Alabama are Predicted by Weather Indices. Environ Entomol 2022; 51:1113-1119. [PMID: 36346638 DOI: 10.1093/ee/nvac082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Indexed: 06/16/2023]
Abstract
The kudzu bug, Megacopta cribraria (Fabricius) (Hemiptera: Plataspidae), is a major economic pest of soybean in the southeastern United States. With climate warming, this pest is expected to move northward and cause additional crop damage. Parasitoid biocontrol is a potential method of integrated pest management for kudzu bug. Two species of egg parasitoid wasps have been observed emerging from kudzu bug egg masses in the southeastern United States: Paratelenomus saccharalis (Dodd) (Hymenoptera: Platygastridae) and Ooencyrtus nezarae (Ishii) (Hymenoptera: Encyrtidae). This paper used egg mass emergence data collected between 2018 and 2020 in Alabama soybean fields and compared the data to weather indices. Indices included the number of days with minimum temperatures below zero, accumulated rainfall (mm m-2), as well as species specific metrics of accumulated growing degree days, accumulated daily minimum temperature (°C), and accumulated daily maximum temperature (°C). Emergence of the generalist parasitoid, O. nezarae, was highly correlated with kudzu bug nymph abundance, accumulated degree day, accumulated daily temperatures, and precipitation. Ooencyrtus nezarae emergence was predicted in a stepwise regression equation by aggregated degree day and date of collection, which indicates that seasonality may be a predictor of its presence. In contrast, collections of the specialist parasitoid, P. saccharalis, were near-zero throughout the collection period, suggesting that this species may no longer be a usable biocontrol agent in the southeastern United States as a result of external limiting factors.
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Affiliation(s)
- Ana M Chicas-Mosier
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA
| | - Rammohan R Balusu
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA
- BASF Agricultural Products Group, Research Triangle, NC 27709, USA
| | - Olufemi S Ajayi
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA
- Alabama State University Department of Biological Sciences, Montgomery, AL 36104, USA
| | - Basu D Kafle
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA
- Texas A&M University Department of Entomology, College Station, TX 77843, USA
| | - Tolulope Morawo
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA
- United States Navy Environmental and Preventive Medicine Unit Five, San Diego, CA 92136, USA
| | - Gamze Mertoglu
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA
- Biological Control Research Institute, Adana, 01321, Turkey
| | - Chelsea M Smith
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA
| | - Sanower Warsi
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA
| | - Henry Y Fadamiro
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA
- Texas A&M University Department of Entomology, College Station, TX 77843, USA
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Ibrahim I, Syamala S, Ayariga JA, Xu J, Robertson BK, Meenakshisundaram S, Ajayi OS. Modulatory Effect of Gut Microbiota on the Gut-Brain, Gut-Bone Axes, and the Impact of Cannabinoids. Metabolites 2022; 12:metabo12121247. [PMID: 36557285 PMCID: PMC9781427 DOI: 10.3390/metabo12121247] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/30/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
The gut microbiome is a collection of microorganisms and parasites in the gastrointestinal tract. Many factors can affect this community's composition, such as age, sex, diet, medications, and environmental triggers. The relationship between the human host and the gut microbiota is crucial for the organism's survival and development, whereas the disruption of this relationship can lead to various inflammatory diseases. Cannabidiol (CBD) and tetrahydrocannabinol (THC) are used to treat muscle spasticity associated with multiple sclerosis. It is now clear that these compounds also benefit patients with neuroinflammation. CBD and THC are used in the treatment of inflammation. The gut is a significant source of nutrients, including vitamins B and K, which are gut microbiota products. While these vitamins play a crucial role in brain and bone development and function, the influence of gut microbiota on the gut-brain and gut-bone axes extends further and continues to receive increasing scientific scrutiny. The gut microbiota has been demonstrated to be vital for optimal brain functions and stress suppression. Additionally, several studies have revealed the role of gut microbiota in developing and maintaining skeletal integrity and bone mineral density. It can also influence the development and maintenance of bone matrix. The presence of the gut microbiota can influence the actions of specific T regulatory cells, which can lead to the development of bone formation and proliferation. In addition, its metabolites can prevent bone loss. The gut microbiota can help maintain the bone's equilibrium and prevent the development of metabolic diseases, such as osteoporosis. In this review, the dual functions gut microbiota plays in regulating the gut-bone axis and gut-brain axis and the impact of CBD on these roles are discussed.
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Affiliation(s)
- Iddrisu Ibrahim
- The Microbiology Program, Department of Biological Sciences, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL 36104, USA
| | - Soumyakrishnan Syamala
- Departments of Medicine, SUNY Downstate Health Sciences University, Brooklyn, NY 11203, USA
| | - Joseph Atia Ayariga
- The Industrial Hemp Program, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL 36104, USA
- Correspondence: (J.A.A.); (O.S.A.)
| | - Junhuan Xu
- The Industrial Hemp Program, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL 36104, USA
| | - Boakai K. Robertson
- The Microbiology Program, Department of Biological Sciences, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL 36104, USA
| | - Sreepriya Meenakshisundaram
- Department of Microbiology and Biotechnology, JB Campus, Bangalore University, Bangalore 560 056, Karnataka, India
| | - Olufemi S. Ajayi
- The Industrial Hemp Program, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL 36104, USA
- Correspondence: (J.A.A.); (O.S.A.)
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Gildea L, Ayariga JA, Xu J, Villafane R, Robertson BK, Samuel-Foo M, Ajayi OS. Cannabis sativa CBD Extract Exhibits Synergy with Broad-Spectrum Antibiotics against Salmonella enterica subsp. Enterica serovar typhimurium. Microorganisms 2022; 10:microorganisms10122360. [PMID: 36557613 PMCID: PMC9784314 DOI: 10.3390/microorganisms10122360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/21/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022] Open
Abstract
New generation antibiotics are needed to combat the development of resistance to antimicrobials. One of the most promising new classes of antibiotics is cannabidiol (CBD). It is a non-toxic and low-resistance chemical that can be used to treat bacterial infections. The antibacterial activity of Cannabis sativa L. byproducts, specifically CBD, has been of growing interest in the field of novel therapeutics. As research continues to define and characterize the antibacterial activity that CBD possesses against a wide variety of bacterial species, it is important to examine potential interactions between CBD and common therapeutics such as broad-spectrum antibiotics. In this study it is demonstrated that CBD-antibiotic (combination of CBD and antibiotic) co-therapy can effectively fight Salmonella typhimurium (S. typhimurium) via membrane integrity disruption. This research serves to examine the potential synergy between CBD and three broad-spectrum antibiotics (ampicillin, kanamycin, and polymyxin B) for potential CBD-antibiotic co-therapy. In this study, it is revealed that S. typhimurium growth is inhibited at very low dosages of CBD-antibiotic. This interesting finding demonstrates that CBD and CBD-antibiotic co-therapies are viable novel alternatives to combating S. typhimurium.
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Affiliation(s)
- Logan Gildea
- The Microbiology Program, Department of Biological Sciences, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL 36104, USA
| | - Joseph Atia Ayariga
- The Industrial Hemp Program, Department of Biological Sciences, Alabama State University, Montgomery, AL 36104, USA
- Correspondence: (J.A.A.); (O.S.A.)
| | - Junhuan Xu
- The Industrial Hemp Program, Department of Biological Sciences, Alabama State University, Montgomery, AL 36104, USA
| | - Robert Villafane
- The Microbiology Program, Department of Biological Sciences, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL 36104, USA
| | - Boakai K. Robertson
- The Microbiology Program, Department of Biological Sciences, College of Science, Technology, Engineering, and Mathematics (C-STEM), Alabama State University, Montgomery, AL 36104, USA
| | - Michelle Samuel-Foo
- The Industrial Hemp Program, Department of Biological Sciences, Alabama State University, Montgomery, AL 36104, USA
| | - Olufemi S. Ajayi
- The Industrial Hemp Program, Department of Biological Sciences, Alabama State University, Montgomery, AL 36104, USA
- Correspondence: (J.A.A.); (O.S.A.)
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Ajayi OS, Samuel-Foo M. Hemp Pest Spectrum and Potential Relationship between Helicoverpa zea Infestation and Hemp Production in the United States in the Face of Climate Change. Insects 2021; 12:insects12100940. [PMID: 34680709 PMCID: PMC8541464 DOI: 10.3390/insects12100940] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 10/06/2021] [Accepted: 10/12/2021] [Indexed: 11/20/2022]
Abstract
Simple Summary Cultivation of industrial hemp Cannabis sativa in the United States is now being expanded due to the recent legalization of the crop. Multiple insect pests attack the crop. One of the common pests is the corn earworm Helicoverpa zea that causes extensive damage to the marketable parts of hemp. Changing global climate may lead to expansion of the geographic range of insect pests. Thus, growers of this crop in the United States have to face new and intense pest problems now and in the years to come. Here, we assess the potential relationship between corn earworm infestation and hemp production in the US in the face of climate change. We also provide an update on the arthropods associated with hemp cultivation across the US. Climate change can affect aspects of interactions between hemp and corn earworm. Temperature and photoperiod affect the development and diapause process in H. zea. Drought leads to a reduction in hemp growth. Overall, our assessment suggests the selection of varieties resistant to stresses from climate and insects. Host plant diversity may prevent populations of corn earworm from reaching outbreak levels. Ongoing research on effective management of H. zea on hemp is critical. Abstract There has been a resurgence in the cultivation of industrial hemp, Cannabis sativa L., in the United States since its recent legalization. This may facilitate increased populations of arthropods associated with the plant. Hemp pests target highly marketable parts of the plant, such as flowers, stalks, and leaves, which ultimately results in a decline in the quality. Industrial hemp can be used for several purposes including production of fiber, grain, and cannabidiol. Thus, proper management of pests is essential to achieve a substantial yield of hemp in the face of climate change. In this review, we provide updates on various arthropods associated with industrial hemp in the United States and examine the potential impact of climate change on corn earworm (CEW) Helicoverpa zea Boddie, a major hemp pest. For example, temperature and photoperiod affect the development and diapause process in CEW. Additionally, drought can lead to a reduction in hemp growth. Host plant diversity of CEW may prevent populations of the pest from reaching outbreak levels. It is suggested that hemp varieties resistant to drought, high soil salinity, cold, heat, humidity, and common pests and diseases should be selected. Ongoing research on effective management of CEW in hemp is critical.
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Isinkaye MO, Ajilu FS, Ibikunle SB, Ajayi OS. COMMITTED EFFECTIVE DOSE FROM NATURAL RADIONUCLIDES IN FARM-RAISED AND WILD CATFISH IN IBADAN, NIGERIA. Radiat Prot Dosimetry 2021; 193:1-7. [PMID: 33646293 DOI: 10.1093/rpd/ncab011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 06/12/2023]
Abstract
There is extensive contamination of the aquatic environment when rivers and streams flow through areas of high human activities such as industrial cities and major towns. These contaminations may include enhanced background levels of naturally occurring radioactive materials resulting from rapid urbanization and other human activities. The natural radionuclides (40K, 238U (226Ra) and 232Th (228Ra)) contents of farm-raised and wild catfish in five fish farms and three major rivers within Ibadan metropolis have been studied using gamma spectrometry. The results indicate that the average committed effective doses from the ingestion of the two sets of catfishes are 104 ± 37 and 104 ± 32 μSv/y for farm-raised and wild catfish, respectively. It can be concluded that the consumption of the catfishes poses no immediate radiological hazards to the population of the study area.
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Affiliation(s)
- M O Isinkaye
- Department of Physics, Ekiti State University, PMB 5363 Ado Ekiti, Nigeria
| | - F S Ajilu
- Department of Physics, The Federal University of Technology, PMB 504 Akure, Nigeria
| | - S B Ibikunle
- Department of Physics, The Federal University of Technology, PMB 504 Akure, Nigeria
| | - O S Ajayi
- Department of Physics, The Federal University of Technology, PMB 504 Akure, Nigeria
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Ajayi OS, Chen L, Fadamiro HY. Host preference in parasitic phorid flies: response of Pseudacteon curvatus and P. obtusus to venom alkaloids of native and imported Solenopsis fire ants. CHEMOECOLOGY 2020. [DOI: 10.1007/s00049-020-00313-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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8
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Ajayi OS, Aderogba MA, Obuotor EM, Majinda RRT. Acetylcholinesterase inhibitor from Anthocleista vogelii leaf extracts. J Ethnopharmacol 2019; 231:503-506. [PMID: 30415061 DOI: 10.1016/j.jep.2018.11.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/26/2018] [Accepted: 11/05/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Anthocleista vogelii (Planch) is used in folk medicine in conditions related to inflammation and oxidative stress. This suggests that some of its constituents could possess ability to reduce oxidative damage to cells and ameliorate inflammatory conditions which are two prominent features in the brain of a person suffering from Alzheimer's disease. AIM OF STUDY The leaf extracts were investigated for their bioactive constituents in our quest for novel compounds for the management of Alzheimer's disease. MATERIALS AND METHODS Anthocleista vogelii crude leaf extract obtained from 80% methanol was successively partitioned with n-hexane, dichloromethane (DCM), ethyl acetate (EtOAc) and n-butanol. This gave four solvent fractions of the crude extract. These fractions and isolated compound were subjected to acetylcholinesterase (AChE) inhibitory activity test using the microplate assay method. The structure of the isolated compound was determined using spectroscopic methods (1D and 2D NMR, and MS). RESULTS The results of the acetylcholinesterase inhibitory assay revealed that n-BuOH and ethyl acetate fractions had the best activity with IC50 of 564.58 and 727.63 µg/mL respectively. Activity directed fractionation of each of these fractions led to the isolation of the same compound identified as a C-glucosylflavone; isovitexin-7-O-methyl ether (swertisin). This rare C-glucosylflavone co-exist as two rotamers and exhibited duplication of NMR signals. It is reported from this plant for the first time. Swertisin displayed better acetylcholinesterase inhibitory activity with IC50 of 32.09 µg/mL than physostigmine (eserine) with IC50 of 56.09 µg/mL used as a standard. CONCLUSIONS This study reports isolation and characterization of a rare C-glycosylflavone; isovitexin-7-O-methyl ether (swertisin). Isolated compound exhibited duplication of NMR signals and better acetylcholinesterase inhibitory activity than eserine used as a standard. The activity exhibited by this compound suggests that it could be useful in the management of Alzheimer's disease.
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Affiliation(s)
- O S Ajayi
- Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria; Department of Chemistry, University of Botswana, Gaborone, Botswana
| | - M A Aderogba
- Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria.
| | - E M Obuotor
- Department of Biochemistry, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - R R T Majinda
- Department of Chemistry, University of Botswana, Gaborone, Botswana
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Hu L, Balusu RR, Zhang WQ, Ajayi OS, Lu YY, Zeng RS, Fadamiro HY, Chen L. Intra- and inter-specific variation in alarm pheromone produced by Solenopsis fire ants. Bull Entomol Res 2018; 108:667-673. [PMID: 29223179 DOI: 10.1017/s0007485317001201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Some fire ants of the genus Solenopsis have become invasive species in the southern United States displacing native species by competition. Although the displacement pattern seems clear, the mechanisms underlying competitive advantage remain unclear. The ability of ant workers to produce relatively larger amount of alarm pheromone may correspond to relative greater fitness among sympatric fire ant species. Here we report on quantitative intra-specific (i.e. inter-caste) and inter-specific differences of alarm pheromone component, 2-ethyl-3,6-dimethylpyrazine (2E36DMP), for several fire ant species. The alarm pheromone component was extracted by soaking ants in hexane for 48 h and subsequently quantified by gas chromatography-mass spectrometry at single ion monitoring mode. Solenopsis invicta workers had more 2E36DMP than male or female alates by relative weight; individual workers, however, contained significantly less pyrazine. We thus believe that alarm pheromones may serve additional roles in alates. Workers of Solenopsis richteri, S. invicta, and hybrid (S. richteri × S. invicta) had significantly more 2E36DMP than a native fire ant species, Solenopsis geminata. The hybrid fire ant had significantly less 2E36DMP than the two parent species, S. richteri and S. invicta. It seems likely that higher alarm pheromone content may have favored invasion success of exotic fire ants over native species. We discuss the potential role of inter-specific variation in pyrazine content for the relationship between the observed shifts in the spatial distributions of the three exotic fire ant species in southern United States and the displacement of native fire ant species.
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Affiliation(s)
- L Hu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents,Institute of Zoology, Chinese Academy of Sciences,Beijing 100101,PR China
| | - R R Balusu
- Department of Entomology & Plant Pathology,Auburn University,Auburn, Alabama 36849,USA
| | - W-Q Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents,Institute of Zoology, Chinese Academy of Sciences,Beijing 100101,PR China
| | - O S Ajayi
- Department of Entomology & Plant Pathology,Auburn University,Auburn, Alabama 36849,USA
| | - Y-Y Lu
- College of Agriculture, South China Agricultural University,Guangzhou 510642,PR China
| | - R-S Zeng
- College of Agriculture, South China Agricultural University,Guangzhou 510642,PR China
| | - H Y Fadamiro
- Department of Entomology & Plant Pathology,Auburn University,Auburn, Alabama 36849,USA
| | - L Chen
- State Key Laboratory of Integrated Management of Pest Insects and Rodents,Institute of Zoology, Chinese Academy of Sciences,Beijing 100101,PR China
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Xu M, Lu Z, Lu YY, Balusu RR, Ajayi OS, Fadamiro HY, Appel AG, Chen L. Cuticular hydrocarbon chemistry, an important factor shaping the current distribution pattern of the imported fire ants in the USA. J Insect Physiol 2018; 110:34-43. [PMID: 30130492 DOI: 10.1016/j.jinsphys.2018.08.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 08/17/2018] [Accepted: 08/17/2018] [Indexed: 06/08/2023]
Abstract
Two sibling species, Solenopsis richteri and S. invicta, were both introduced into the southern USA from South America in the early 20th century. Today, S. richteri occupies higher latitudes and colder areas, while S. invicta occupies lower latitudes. Between the distributions of the two species, there is a large area of viable hybrid (S. richteri × S. invicta) populations. This study aimed to characterize the forces driving this distribution pattern and the underlying mechanisms. Cuticular hydrocarbons (CHCs) of freshly killed workers of S. invicta, hybrids, and S. richteri were removed using hexane. Both intact and CHCs-extracted workers were subjected to a constant rate of increasing temperature from 10 to 60 °C to obtain relative water loss and the water loss transition temperature (Tc-ant). Mass loss and Tc-ant were both significantly increased with CHCs removal. We then examined the CHC composition of three species. CHC profiles of S. richteri are characterized by significant amounts of short-chain (C23-C27) saturated and unsaturated hydrocarbons. In contrast, profiles of S. invicta consist primarily of long-chain (C27-C29) saturated hydrocarbons; unsaturated alkenes are completely lacking. Hybrid fire ants show intermediate profiles of the two parent species. We measured the melting point (Tm) and water-loss transition temperature of CHC blends (Tc-CHC) of different ant species colonies using differential scanning calorimetry (DSC) and an artificial membrane system, respectively. There were 3-5 Tms of each CHCs sample of different ant colonies due to their complex chemistry. The highest Tms (Tm-maxs) of CHCs samples from S. invicta and the hybrid were significantly higher than that from S. richteri. The correlation between Tc-CHC and Tm-max obtained from the same CHCs sample was highly significant. These results reveal that species having higher Tc and Tm-max retain more water under relatively higher temperature, and consequently are able to occupy warmer environments. We conclude that CHC chemistry plays a role in shaping current distribution patterns of S. richteri, S. invicta and their hybrid in the United States.
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Affiliation(s)
- Meng Xu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China
| | - ZeKuan Lu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China
| | - Yong-Yue Lu
- Red Imported Fire Ant Research Centre, South China Agricultural University, Guangzhou 510642, PR China
| | - Rammohan R Balusu
- Department of Entomology & Plant Pathology, Auburn University, Auburn, AL 36849, USA
| | - Olufemi S Ajayi
- Department of Entomology & Plant Pathology, Auburn University, Auburn, AL 36849, USA
| | - Henry Y Fadamiro
- Department of Entomology & Plant Pathology, Auburn University, Auburn, AL 36849, USA
| | - Arthur G Appel
- Department of Entomology & Plant Pathology, Auburn University, Auburn, AL 36849, USA.
| | - Li Chen
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China.
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Ajayi OS, Achuka J. Radioactivity in drilled and dug well drinking water of Ogun state Southwestern Nigeria and consequent dose estimates. Radiat Prot Dosimetry 2009; 135:54-63. [PMID: 19482882 DOI: 10.1093/rpd/ncp095] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Activity concentrations of (40)K, (226)Ra, (228)Ac and (235)U were measured in 11 dug and 9 drilled well water samples from 3 large cities in Ogun state, Southwestern Nigeria, consumed by the population living in the cities. The measurement was done using co-axial type high-purity germanium (HPGe) detector (Canberra Industries Inc.). The measured activity concentrations in the water samples ranged from 1.74 +/- 1.83 to 4.69 +/- 0.17 Bq l(-1); 2.89 +/- 0.62 to 7.79 +/- 7.22 Bq l(-1); 0.35 +/- 0.07 to 1.17 +/- 0.40 Bq l(-1) and 0.18 +/- 0.05 to 4.77 +/- 0.34 Bq l(-1) for (40)K, (226)Ra, (228)Ac and (235)U, respectively. Total annual effective dose rates from the ingestion of these radionuclides in the untreated wells were estimated using measured activity concentrations in the radionuclides and their ingested dose conversion factors. Estimated annual effective dose rates ranged from 0.04 to 6.82; 0.01 to 1.36 and 0.01 to 1.49 mSv y(-1) for age groups <1, 2-7 and > or =17 y, respectively. Committed dose for age group > or =17 y ranged from 8.8 x 10(-4) to 8.9 x 10(-2) Sv. The calculated annual effective dose values due to the ingestion of (226)Ra in the Awujale, Ake, Saboab, Alagbon, Alapora and Totoro samples exceeded International Commission on Radiological Protection limit of 1.0 mSv y(-1) for individual public exposure. These wells are recommended for treatment that would remove radium from their waters.
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Affiliation(s)
- O S Ajayi
- Department of Physics, Federal University of Technology, P.M.B. 704, Akure, Ondo State, Nigeria
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Ajayi OS, Ibikunle SB, Ojo TJ. An assessment of natural radioactivity of soils and its external radiological impact in southwestern Nigeria. Health Phys 2008; 94:558-566. [PMID: 18469589 DOI: 10.1097/01.hp.0000309766.12663.1d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Soil samples collected from five states in the southwestern part of Nigeria have been analyzed for activity concentration of gamma-ray emitters. The States were Oyo, Lagos, Ondo, Ogun, and Osun. Activity concentration measurement was carried out using a co-axial type high purity germanium (HPGe) detector. Spectral analyses were performed using spectrometry software. The activity concentration measured ranged from 0.03 +/- 0.2 Bq kg(-1) for 137Cs to 1,358.6 +/- 28.5 Bq kg(-1) for (40)K. (40)K accounted for most of the activity. The calculated absorbed dose rates in air at 1.0 m above the ground ranged from 6 to 303 nGy h(-1) with a mean and standard deviation of 60.5 nGy h(-1) and 63.2 nGy h(-1), respectively. Estimated annual outdoor effective dose equivalent varied from 8 to 370 mSv y(-1). The calculated collective dose equivalent values for the five states ranged from 87,000 person-Sv to 600,000 person-Sv. The estimated annual outdoor effective values were considerably higher than the world soil average value of 70 microSv y(-1) reported by the International Commission on Radiological Protection.
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Affiliation(s)
- O S Ajayi
- Department of Physics, Federal University of Technology, Akure, Ondo State, Nigeria.
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Ajayi OS, Owolabi TP. Determination of natural radioactivity in drinking water in private dug wells in Akure, Southwestern Nigeria. Radiat Prot Dosimetry 2007; 128:477-484. [PMID: 17921510 DOI: 10.1093/rpd/ncm429] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Gamma spectrometry of well water was done to measure the activity concentrations of gamma-emitters 226Ra and 228Ra from 238U and 232Th series, respectively, and 40K in their waters. Measurements were done using high-purity (HPGe) co-axial detectors (Canberra, GC 2018-7500 ) coupled to Canberra Multichannel Analyser system. Activity concentrations ranged from 0.57 to 26.86, 0.20 to 60.06 and 0.35 to 29.01 Bq l(-1) for 226Ra, 228Ra and 40K, respectively. Activity concentrations were compared with data from other parts of the world and used to estimate annual effective dose for three age groups. Total annual effective doses from the intake of these radionuclides in the waters ranged from 0.02 to 76.84, 0.02 to 38.80 and 0.05 to 481.60 mSv y(-1) for age group <1, 2-7 and > or =17 y, respectively. These values are considerably higher than both the World Health Organisation and the International Commission on Radiological Protection limits.
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Affiliation(s)
- O S Ajayi
- Department of Physics, Federal University of Technology, P.M.B. 704, Akure, Nigeria.
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Ajayi OS. Evaluation of absorbed dose rate and annual effective dose equivalent due to terrestrial gamma radiation in rocks in a part of Southwestern Nigeria. Radiat Prot Dosimetry 2002; 98:441-444. [PMID: 12120673 DOI: 10.1093/oxfordjournals.rpd.a006736] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The average outdoor absorbed dose rate in air and the average annual effective dose equivalent due to terrestrial gamma radiation from 40K, 238U and 232Th in rocks in Ondo and Ekiti States, Southwestern Nigeria have been evaluated from measurements of the concentrations of these radionuclides in this environmental material. The concentration measurements were obtained using a very sensitive gamma spectroscopic system consisting of a 7.6 cm x 7.6 cm NaI(Tl) scintillation detector coupled to a computerised ACCUSPEC installation. The average absorbed dose rate and average annual effective dose equivalent was found to be 8.33 +/- 2.76 nGy x h(-1) and 8.7 +/- 2.9 microSv x y(-1) respectively.
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Affiliation(s)
- O S Ajayi
- Department of Physics, Federal University of Technology, Akure, Ondo State, Nigeria
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Abstract
The natural radioactivity in some rock samples in Ikogosi-Ekiti, Southwestern Nigeria, has been measured using a very sensitive gamma spectroscopic system consisting of a 76 mm x 76 mm NaI(TI) scintillation detector system coupled to a versatile Canberra Series 10 plus multichannel analyzer. The average concentrations of natural radioisotopes 238U, 232Th, and 40K are 57.9 +/- 28.1 Bq kg-1, 81.6 +/- 23.8 Bq kg(-1) and 1203.1 +/- 687.2 Bq kg(-1), respectively. These average values give rise to a mean absorbed dose rate of 0.128 +/- 0.051, microGy h(-1) at a height of 1.0 m and an effective dose equivalent of 156.90 microSv (y-1). The results indicate no radiological anomaly. The data presented here will serve as a baseline survey for primordial radionuclide concentrations in rocks of the area.
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Affiliation(s)
- O S Ajayi
- Department of Physics, Federal University of Technology, Akure Ondo State, Nigeria
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