scholarly journals Diversity of midgut bacteria in larvae and females of Aedes aegypti and Aedes albopictus from Gampaha District, Sri Lanka

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Koshila Ranasinghe ◽  
Nayana Gunathilaka ◽  
Deepika Amarasinghe ◽  
Wasana Rodrigo ◽  
Lahiru Udayanga
Keyword(s):  
Sri Lanka ◽  
Aedes Aegypti ◽  
Bacterial Species ◽  
Medical Officer ◽  
Pcr Amplification ◽  
Common Species ◽  
Lysinibacillus Sphaericus ◽  
Immune Priming ◽  
Pantoea Dispersa ◽  
Significant Difference

Abstract Background The midgut microbiota of mosquitoes maintain basal immune activity and immune priming. In recent years, scientists have focused on the use of microbial communities for vector control interventions. In the present study, the midgut bacteria of larvae and adults of Aedes aegypti and Ae. albopictus were assessed using both field-collected and laboratory-reared mosquitoes from Sri Lanka. Methods Adults and larvae of Ae. aegypti and Ae. albopictus were collected from three selected areas in Gampaha Medical Officer of Health area, Gampaha District, Western Province, Sri Lanka. Bacterial colonies isolated from mosquito midgut dissections were identified by PCR amplification and sequencing of partial 16S rRNA gene fragments. Results Adults and larvae of Ae. aegypti and Ae. albopictus harbored 25 bacterial species. Bacillus endophyticus and Pantoea dispersa were found more frequently in field-collected Ae. aegypti and Ae. albopictus adults, respectively. The midgut bacteria of Ae. aegypti and Ae. albopictus adults (X2 = 556.167, df = 72, P < 0.001) and larvae (X2 = 633.11, df = 66, P < 0.001) were significantly different. There was a significant difference among the bacterial communities between field-collected adults (X2 = 48.974, df = 10, P < 0.001) and larvae (X2 = 84.981, df = 10, P < 0.001). Lysinibacillus sphaericus was a common species in adults and larvae of laboratory-reared Ae. aegypti. Only P. dispersa occurred in the field-collected adults of Ae. aegypti and Ae. albopictus. Species belonging to genera Terribacillus, Lysinibacillus, Agromyces and Kocuria were recorded from Aedes mosquitoes, in accordance with previously reported results. Conclusions This study generated a comprehensive database on the culturable bacterial community found in the midgut of field-collected (Ae. aegypti and Ae. albopictus) and laboratory-reared (Ae. aegypti) mosquito larvae and adults from Sri Lanka. Data confirm that the midgut bacterial diversity in the studied mosquitoes varies according to species, developmental stage and strain (field vs laboratory). Graphical abstract

scholarly journals Population Dynamics and Breeding Preference of Aedes Aegypti and Ae. Albopictus Attributing to Dengue Threat in Kelaniya Medical Officer of Health Area in Sri Lanka

2021 ◽  
Author(s):  
L D Amarasinghe ◽  
P. V J. Nadeeka
Keyword(s):  
Population Dynamics ◽  
Sri Lanka ◽  
Aedes Aegypti ◽  
Medical Officer ◽  
Abundant Species ◽  
Mixed Population ◽  
Weather Factors ◽  
Dengue Transmission ◽  
Risk Areas ◽  
Indoor And Outdoor

Abstract Background Aedes aegypti and Ae. albopictus are the two species of dengue vector mosquitoes in Sri Lanka. Indoor and outdoor distribution of these species, their population dynamics and breeding preference are important factors determining the dengue transmission. Gampaha district in Sri Lanka reported to have frequent dengue epidemics from recent past, hence this study was conducted.Methods Ovitrap surveillance was conducted to determine the vector species distribution in indoor and outdoor in Kelaniya Medical Officer of Health (MOH) area of the Gampaha district. Larvae were reared in the laboratory until adults were emerged to identify species morphologically. Breeding preference of vector mosquitoes were carried out by physically observing the presence of mosquito larvae in water collected receptacles in the area. Results Aedes aegypti and Ae. albopictus were reported to distribute throughout Kelaniya MOH area as a mixed population. Ae. albopictus is the most abundant species both indoor and outdoor in Kelaniya MOH area compared to Ae. aegypti. Weather factors, rain days and wind positively correlated with Aedes population. Conclusions Aedes aegypti and Ae. albopictus are frequently present in Kelaniya MOH area as mixed population. High risk areas of the study area were identified.

scholarly journals Impact of haze events on airborne bacterial consortia–a case study

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
S. M. N. K. Thilakarathne ◽  
A. Ekanayake ◽  
P. S. Madamarandawala ◽  
W. B. C. P. Weerarathne ◽  
C. A. Thotawatthage ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Pathogenic Bacteria ◽  
Negative Impact ◽  
Anthropogenic Activities ◽  
Bacterial Species ◽  
Bacterial Load ◽  
Common Species ◽  
Burkholderia Multivorans ◽  
Bacterial Consortia ◽  
Haze Event

AbstractTransboundary haze events received a noticeable attention recently, due to their frequent occurrences. They are mainly, consequences of anthropogenic activities. Sri Lanka experienced a haze event parallel to India in November 2019, the first air pollution event in Sri Lanka linked to a haze event in India. Due to the limited availability of information on haze-related microorganisms, we conducted this study in Kandy, Sri Lanka, aiming to explore the airborne bacterial consortia during a haze event. The natural sedimentation method was used for air sampling. Bacterial identification and the total bacterial load were determined using Sanger sequencing and qPCR. Notably, the total bacterial load was elevated by ~ 40% with the haze and decreased with decreasing haze intensity. The highest bacterial load was reported during the day time of the most intense hazy day (1.89 × 106 cells/µl) compared to non-hazy days (lowest; 1.12 × 105 cells/µl). Twelve bacterial species were identified and the most abundant phylum was Proteobacteria. The most common species observed during haze was Acinetobacter modestus. The percentage of culturable bacterial species was also high during the haze event (75% during day time of the most intense hazy day compared to 25% on the control). Two human pathogenic bacteria Burkholderia multivorans and Chryseobacterium gleum were found only during the haze event. Therefore, haze events could be hazardous to humans by means of the presence and fluctuating amounts of pathogenic bacteria. Thus, these findings are important in developing policies and guidelines to monitor and minimize the negative impact of haze events.

scholarly journals A Challenge for a Unique Dengue Vector Control Programme: Assessment of the Spatial Variation of Insecticide Resistance Status amongst Aedes aegypti and Aedes albopictus Populations in Gampaha District, Sri Lanka

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Rasika Dalpadado ◽  
Nayana Gunathilaka ◽  
Deepika Amarasinghe ◽  
Lahiru Udayanaga
Keyword(s):  
Sri Lanka ◽  
Aedes Aegypti ◽  
Insecticide Resistance ◽  
Vector Control ◽  
Aedes Albopictus ◽  
Rural Areas ◽  
Medical Officer ◽  
Public Health Problem ◽  
World Health ◽  
Susceptibility Status

Background. To date, dengue is considered an important public health problem in Sri Lanka. Irrational use of insecticides without evidence-based applications has primed the development of resistance in mosquito vectors. Method. The present study investigated the resistance status of Aedes aegypti and Aedes albopictus to commonly used insecticides in three selected Medical Officer of Health (MOH) areas (i.e., Attanagalla, Dompe, and Negombo) in Gampaha District, Western Province of Sri Lanka. Entomological surveys were performed using ovitraps and larval collections. Larval bioassays were carried out to determine the LC50, LC90, and LC95 and susceptibility status for organophosphate temephos, whereas adult bioassays were performed to test the 0.03% deltamethrin and 0.8% malathion susceptibility. Results. The study revealed that the temephos concentrations required to control Ae. aegypti (13.7-17.7 times) and Ae. albopictus (4.6-7.6 times) are higher than the diagnostic concentration (0.012 mg/L) proposed by the World Health Organization. The highest resistance levels were observed for both Ae. aegypti ( 14 ± 1.87 ) and Ae. albopictus ( 36 ± 1.87 ) collected from the Negombo MOH area. Therefore, the WHO recommended diagnostic concentration is no longer effective in controlling Ae. aegypti and Ae. albopictus larvae in these areas. Both the dengue vectors have evolved a high level of insecticide resistance to malathion and deltamethrin in the Gampaha District except Ae. albopictus mosquitoes in rural areas. Further, vectors in rural areas are indicated susceptible (>98%) to pyrethroids and emergence of resistance (<97%) for organophosphate insecticides. Conclusion. The results of this study warrant the vector management authorities on the proper application of insecticides and rational use in vector control. The susceptibility status of vector mosquitoes should be continuously monitored especially in dengue-endemic areas parallel to the routine surveillance programme. Further molecular studies are strongly recommended to determine the Knockdown Resistance (kdr) mutations among Aedes populations.

Assessment of Bacterial Contamination of Orthodontic Arch wire

2019 ◽  
Vol 31 (1) ◽  
pp. 48-51
Author(s):  
Suha S Hassan ◽  
Nidhal H. Ghaib ◽  
Batool H Al-Ghurabi
Keyword(s):  
Bacterial Contamination ◽  
Microbial Contamination ◽  
Ethylenediaminetetraacetic Acid ◽  
Bacterial Species ◽  
Brain Heart Infusion ◽  
Control Groups ◽  
Dental Practitioners ◽  
Significant Difference ◽  
Bacillus Spp ◽  
Droplet Transmission

Background: The microorganisms can impend the life of health care professional and particularly the dental practitioners. They can be transmitted by different ways like airborne and droplet transmission. The current study was carried out to identify whether the arch wires that received from the manufactures are free from microbial contamination and to determine the bacterial species attached to the arch wires. Materials and Methods: This study involved eighty samples, consisted of two types of arch wires (nitinol and stainless-steel) from four companies (3M, G&H, Jiscop, OrthoTechnology). These wires inserted in a plane tube that contains 10 -ml of (Tris [tris(hydroxymethyl)aminomethane] and EDTA (ethylenediaminetetraacetic acid) tris-EDTA and brain heart infusion (BHI) broth. A 0.1 ml was withdrawn from the tube and spread on agar plates. The control groups consist of 16 plane tube (8 tubes with tris-EDTA and other 8 tubes with (BHI). Results: Microbial sampling yielded growth from 5 of the 80 arch wires. The predominant bacteria that isolated were Bacillus spp. No growth was recovered from 75 of the samples and from controls. The bacteria were isolated by BHI reagent and no growth was observed by tris-EDTA reagent with statistically significant difference (P<0.05). The Bacillus spp. found only in the G&H and Jiscop companies, however, no statistically significant difference was found among them (P>0.05). With regard to the presence and distribution of bacteria according to the types of wires, the present results clarified that cases of contamination with Bacillus spp. were found in the nitinol arch wires with statistically significant difference (P<0.05). Conclusions: The results of the current study revealed low count of bacterial contamination in the two types of companies (G&H and Jiscop). Not all materials that received from the manufactures are free from contamination and an effective sterilization regimen is needed to avoid cross-contamination.

scholarly journals Implementation of a deep learning model for automated classification of Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) in real time

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Song-Quan Ong ◽  
Hamdan Ahmad ◽  
Gomesh Nair ◽  
Pradeep Isawasan ◽  
Abdul Hafiz Ab Majid
Keyword(s):  
Deep Learning ◽  
Aedes Aegypti ◽  
Real Time ◽  
Aedes Albopictus ◽  
Automated Classification ◽  
Expert Performance ◽  
Deep Convolutional Neural Networks ◽  
Significant Difference ◽  
Set Up

AbstractClassification of Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) by humans remains challenging. We proposed a highly accessible method to develop a deep learning (DL) model and implement the model for mosquito image classification by using hardware that could regulate the development process. In particular, we constructed a dataset with 4120 images of Aedes mosquitoes that were older than 12 days old and had common morphological features that disappeared, and we illustrated how to set up supervised deep convolutional neural networks (DCNNs) with hyperparameter adjustment. The model application was first conducted by deploying the model externally in real time on three different generations of mosquitoes, and the accuracy was compared with human expert performance. Our results showed that both the learning rate and epochs significantly affected the accuracy, and the best-performing hyperparameters achieved an accuracy of more than 98% at classifying mosquitoes, which showed no significant difference from human-level performance. We demonstrated the feasibility of the method to construct a model with the DCNN when deployed externally on mosquitoes in real time.

scholarly journals Butanol Tolerance of Lactiplantibacillus plantarum: A Transcriptome Study

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 181
Author(s):  
Kaloyan Petrov ◽  
Alexander Arsov ◽  
Penka Petrova
Keyword(s):  
Bacterial Species ◽  
Transcriptional Regulators ◽  
Common Species ◽  
Glycerol Metabolism ◽  
Phosphotransferase System ◽  
Promising Alternative ◽  
Butanol Tolerance ◽  
Polysaccharide Biosynthesis ◽  
Major Factors ◽  
Butanol Stress

Biobutanol is a promising alternative fuel with impaired microbial production thanks to its toxicity. Lactiplantibacillus plantarum (L. plantarum) is among the few bacterial species that can naturally tolerate 3% (v/v) butanol. This study aims to identify the genetic factors involved in the butanol stress response of L. plantarum by comparing the differential gene expression in two strains with very different butanol tolerance: the highly resistant Ym1, and the relatively sensitive 8-1. During butanol stress, a total of 319 differentially expressed genes (DEGs) were found in Ym1, and 516 in 8-1. Fifty genes were upregulated and 54 were downregulated in both strains, revealing the common species-specific effects of butanol stress: upregulation of multidrug efflux transporters (SMR, MSF), toxin-antitoxin system, transcriptional regulators (TetR/AcrR, Crp/Fnr, and DeoR/GlpR), Hsp20, and genes involved in polysaccharide biosynthesis. Strong inhibition of the pyrimidine biosynthesis occurred in both strains. However, the strains differed greatly in DEGs responsible for the membrane transport, tryptophan synthesis, glycerol metabolism, tRNAs, and some important transcriptional regulators (Spx, LacI). Uniquely upregulated in the butanol-resistant strain Ym1 were the genes encoding GntR, GroEL, GroES, and foldase PrsA. The phosphoenolpyruvate flux and the phosphotransferase system (PTS) also appear to be major factors in butanol tolerance.

Effect of Type of Tissue on the Development of Chrysomya rufifacies (Diptera: Calliphoridae) in Sri Lanka

2021 ◽  
Author(s):  
Y T B Bambaradeniya ◽  
W A I P Karunaratne ◽  
J K Tomberlin ◽  
P A Magni
Keyword(s):  
Skeletal Muscle ◽  
Sri Lanka ◽  
Forensic Entomology ◽  
Development Time ◽  
Developmental Studies ◽  
Chrysomya Rufifacies ◽  
Significant Difference ◽  
The World ◽  
Significant Temperature ◽  
Domestic Swine

Abstract Chrysomya rufifacies (Macquart), the hairy maggot blow fly, is of great importance for the field of forensic entomology due to its habit as an early colonizer of decomposing vertebrate remains and myiasis producer. Development studies on this species have been conducted in scattered regions of the world, using types of tissue from several species of animals as a rearing medium. Despite the commonality of C. rufifacies in Sri Lanka, developmental studies have never been performed in this region. As well, the effects of diet on development have not been tested. In the current study, C. rufifacies immatures were reared on skeletal muscle, liver, and heart from domestic swine, with flies from colonies maintained at 25 and 28°C. The minimum time needed to complete each stage at 25°C on liver (224.14 h) was fastest followed by skeletal muscle (249.33 h) and heart (251.64 h) respectively, whereas at 28°C, fly development was quickest on heart muscle (178.27 h) followed by liver (178.50 h) and skeletal muscle (186.17 h) respectively. A significant difference in total development time was determined for temperature, while the rearing medium was not significant. Temperature also showed a significant effect on the length and the width of the larvae, while the type of tissue statistically impacted only the width.

Development of a Cavity Disinfectant Containing Antibacterial Monomer MDPB

2016 ◽  
Vol 95 (13) ◽  
pp. 1487-1493 ◽  
Author(s):  
N. Hirose ◽  
R. Kitagawa ◽  
H. Kitagawa ◽  
H. Maezono ◽  
A. Mine ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Bond Strength ◽  
Bacterial Species ◽  
Oral Bacteria ◽  
Resin Cement ◽  
Resin Cements ◽  
Adhesive Resin ◽  
Significant Difference ◽  
Adhesive Resin Cement

An experimental cavity disinfectant (ACC) that is intended to be used for various direct and indirect restorations was prepared by adding an antibacterial monomer 12-methacryloyloxydodecylpyridinum bromide (MDPB) at 5% into 80% ethanol. The antibacterial effectiveness of ACC and its influences on the bonding abilities of resin cements were investigated. To examine the antibacterial activity of unpolymerized MDPB, the minimum inhibitory and bactericidal concentrations (MIC and MBC) were determined for Streptococcus mutans, Lactobacillus casei, Actinomyces naeslundii, Parvimonas micra, Enterococcus faecalis, Fusobacterium nucleatum, and Porphyromonas gingivalis. Antibacterial activities of ACC and the commercial cavity disinfectant containing 2% chlorhexidine and ethanol (CPS) were evaluated by agar disk diffusion tests through 7 bacterial species and by MIC and MBC measurement for S. mutans. The effects of ACC and CPS to kill bacteria in dentinal tubules were compared with an S. mutans–infected dentin model. Shear bond strength tests were used to examine the influences of ACC on the dentin-bonding abilities of a self-adhesive resin cement and a dual-cure resin cement used with a primer. Unpolymerized MDPB showed strong antibacterial activity against 7 oral bacteria. ACC produced inhibition zones against all bacterial species similar to CPS. For ACC and CPS, the MIC value for S. mutans was identical, and the MBC was similar with only a 1-step dilution difference (1:2). Treatment of infected dentin with ACC resulted in significantly greater bactericidal effects than CPS ( P < 0.05, analysis of variance and Tukey’s honest significant difference test). ACC showed no negative influences on the bonding abilities to dentin for both resin cements, while CPS reduced the bond strength of the self-adhesive resin cement ( P < 0.05). This study clarified that the experimental cavity disinfectant containing 5% MDPB is more effective in vitro than the commercially available chlorhexidine solution to eradicate bacteria in dentin, without causing any adverse influences on the bonding abilities of resinous luting cements.

scholarly journals Slow Genetic Divergence of Helicobacter pylori Strains during Long-Term Colonization

2005 ◽  
Vol 73 (8) ◽  
pp. 4818-4822 ◽  
Author(s):  
Annelie Lundin ◽  
Britta Björkholm ◽  
Ilya Kupershmidt ◽  
Magnus Unemo ◽  
Peter Nilsson ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Genetic Divergence ◽  
Bacterial Species ◽  
Pcr Amplification ◽  
Genetic Change ◽  
Genetic Changes ◽  
Single Strain ◽  
Divergent Gene ◽  
Asymptomatic Adult ◽  
H Pylori

ABSTRACT The genetic variability of Helicobacter pylori is known to be high compared to that of many other bacterial species. H. pylori is adapted to the human stomach, where it persists for decades, and adaptation to each host results in every individual harboring a distinctive bacterial population. Although clonal variants may exist within such a population, all isolates are generally genetically related and thus derived from a common ancestor. We sought to determine the rate of genetic change of H. pylori over 9 years in two asymptomatic adult patients. Arbitrary primed PCR confirmed the relatedness of individual subclones within a patient. Furthermore, sequencing of 10 loci (∼6,000 bp) in three subclones per time and patient revealed only two base pair changes among the subclones from patient I. All sequences were identical among the patient II subclones. However, PCR amplification of the highly divergent gene amiA revealed great variation in the size of the gene between the subclones within each patient. Thus, both patients harbored a single strain with clonal variants at both times. We also studied genetic changes in culture- and mouse-passaged strains, and under both conditions no genetic divergence was found. These results suggest that previous estimates of the rate of genetic change in H. pylori within an individual might be overestimates.

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