Molecular detection and genetic diversity of Leucocytozoon sabrazesi in chickens in Thailand

AbstractLeucocytozoon sabrazesi is the intracellular protozoa of leucocytozoonosis, which is transmitted by the insect vectors and affects chickens in most subtropical and tropical regions of the globe, except South America, and causing enormous economic losses due to decreasing meat yield and egg production. In this study, L. sabrazesi gametocytes have been observed in the blood smears, and molecular methods have been used to analyse the occurrence and genetic diversity of L. sabrazesi in blood samples from 313 chickens raised in northern, western and southern parts of Thailand. The nested polymerase chain reaction (nested PCR) assay based on the cytb gene revealed that 80.51% (252/313) chickens were positive of L. sabrazesi. The phylogenetic analysis indicated that L. sabrazesi cytb gene is conserved in Thailand, showed 2 clades and 2 subclades with similarity ranged from 89.5 to 100%. The diversity analysis showed 13 and 18 haplotypes of the sequences from Thailand and from other countries, respectively. The entropy analyses of nucleic acid sequences showed 26 high entropy peaks with values ranging from 0.24493 to 1.21056, while those of amino acid sequences exhibited 5 high entropy peaks with values ranging from 0.39267 to 0.97012. The results; therefore, indicate a high molecular occurrence of L. sabrazesi in chicken blood samples with the associated factors that is statistically significant (p < 0.05). Hence, our results could be used to improve the immunodiagnostic methods and to find appropriate preventive control strategies or vaccination programs against leucocytozoonosis in order to mitigate or eliminate the harmful impact of this infection on chicken industry.

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Genetic diversity and population structure of Plasmodium falciparum in Nigeria: insights from microsatellite loci analysis

Malaria Journal ◽

10.1186/s12936-021-03734-x ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Fehintola V. Ajogbasile ◽

Adeyemi T. Kayode ◽

Paul E. Oluniyi ◽

Kazeem O. Akano ◽

Jessica N. Uwanibe ◽

...

Keyword(s):

Genetic Diversity ◽

Plasmodium Falciparum ◽

Population Structure ◽

Microsatellite Loci ◽

Control Strategies ◽

Population Diversity ◽

Parasite Population ◽

Nested Polymerase Chain Reaction ◽

Public Health Burden ◽

Genetic Diversity And Structure

Abstract Background Malaria remains a public health burden especially in Nigeria. To develop new malaria control and elimination strategies or refine existing ones, understanding parasite population diversity and transmission patterns is crucial. Methods In this study, characterization of the parasite diversity and structure of Plasmodium falciparum isolates from 633 dried blood spot samples in Nigeria was carried out using 12 microsatellite loci of P. falciparum. These microsatellite loci were amplified via semi-nested polymerase chain reaction (PCR) and fragments were analysed using population genetic tools. Results Estimates of parasite genetic diversity, such as mean number of different alleles (13.52), effective alleles (7.13), allelic richness (11.15) and expected heterozygosity (0.804), were high. Overall linkage disequilibrium was weak (0.006, P < 0.001). Parasite population structure was low (Fst: 0.008–0.105, AMOVA: 0.039). Conclusion The high level of parasite genetic diversity and low population structuring in this study suggests that parasite populations circulating in Nigeria are homogenous. However, higher resolution methods, such as the 24 SNP barcode and whole genome sequencing, may capture more specific parasite genetic signatures circulating in the country. The results obtained can be used as a baseline for parasite genetic diversity and structure, aiding in the formulation of appropriate therapeutic and control strategies in Nigeria.

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Genetic Diversity and Population Structure of the Asian Tiger Mosquito (Aedes albopictus) in Vietnam: Evidence for Genetic Differentiation by Climate Region

Genes ◽

10.3390/genes12101579 ◽

2021 ◽

Vol 12 (10) ◽

pp. 1579

Author(s):

Cuong Van Duong ◽

Ji Hyoun Kang ◽

Vinh Van Nguyen ◽

Yeon Jae Bae

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Aedes Albopictus ◽

Disease Transmission ◽

Climatic Factors ◽

Control Strategies ◽

Geographic Distance ◽

Coi Gene ◽

Tropical Regions ◽

Climatic Regions

Aedes albopictus is a native mosquito to Southeast Asia with a high potential for disease transmission. Understanding how Ae. albopictus populations that develop in the species’ native range is useful for planning future control strategies and for identifying the sources of invasive ranges. The present study aims to investigate the genetic diversity and population structure of Ae. albopictus across various climatic regions of Vietnam. We analyzed mitochondrial cytochrome oxidase I (COI) gene sequences from specimens collected from 16 localities, and we used distance-based redundancy analysis to evaluate the amount of variation in the genetic distance that could be explained by both geographic distance and climatic factors. High levels of genetic polymorphism were detected, and the haplotypes were similar to those sequences from both temperate and tropical regions worldwide. Of note, these haplotype groups were geographically distributed, resulting in a distinct population structure in which northeastern populations and the remaining populations were genetically differentiated. Notably, genetic variation among the Ae. albopictus populations was driven primarily by climatic factors (64.55%) and to a lesser extent was also influenced by geographic distance (33.73%). These findings fill important gaps in the current understanding of the population genetics of Ae. albopictus in Vietnam, especially with respect to providing data to track the origin of the invaded regions worldwide.

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Genetic Diversity and Prevalence of Porcine Circovirus Type 2 in China During 2000-2019

Frontiers in Veterinary Science ◽

10.3389/fvets.2021.788172 ◽

2021 ◽

Vol 8 ◽

Author(s):

Ning Li ◽

Jing Liu ◽

Jiali Qi ◽

Feng Hao ◽

Lei Xu ◽

...

Keyword(s):

Genetic Diversity ◽

Wide Distribution ◽

Porcine Circovirus Type ◽

Porcine Circovirus Type 2 ◽

Amino Acid Sequences ◽

Porcine Circovirus ◽

Economic Losses ◽

Swine Industry ◽

Emerging Virus

As the major pathogen for porcine circovirus-associated disease (PCVAD), porcine circovirus type 2 (PCV2) is no longer treated as an emerging virus anymore. The wide distribution of PCV2 infection in China causes huge economic losses in the swine industry. Currently, it is generally believed that PCV2 has eight genotypes (PCV2a to PCV2h), with PCV2a, PCV2b, and PCV2d being widely distributed. To comprehensively explore the genetic diversity and prevalence of PCV2 in China, PCV-2 sequences submitted from China in the GenBank database were retrieved. With a total of 714 PCV2 strains were retrieved, we found that early-submitted PCV2 sequences were mainly collected from coastal provinces in the southeast part of China, which may indicate PCV2 was initially circulating in those regions. From 2002 to 2008, PCV2b was the dominant prevalent genotype in those retrieved sequences. From 2009, PCV2d became the dominant genotype in those sequences, dropping a hint that a potential shift of PCV2b to PCV2d might occur in 2009, which is similar to the patterns at the global level. In addition to the PCV2a, PCV2b, and PCV2d genotypes, novel strains were also characterized. We further revealed that the amino acid sequences consistency of PCV2a Cap is higher than those in other genotypes. Together, this study provided clues for the possible prevalent genotypes and dynamics of genetic diversity in China from 2000 to 2019.

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Epidemiology of Leishmania Carriers in Tan Chang County, Gansu Province, China

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2021.645944 ◽

2021 ◽

Vol 11 ◽

Author(s):

Shuai Han ◽

Sheng-bang Chen ◽

Zhang-hong Yang ◽

Yu Feng ◽

Wei-ping Wu

Keyword(s):

Clinical Symptoms ◽

Control Strategies ◽

Phylogenetic Analyses ◽

Gansu Province ◽

Diaphragm Muscle ◽

Serum Globulin ◽

Nested Polymerase Chain Reaction ◽

Blood Samples ◽

Source Of Infection ◽

Strip Test

BackgroundLeishmaniasis is a regional infectious disease caused by the bite of Leishmania-carrying sandflies. The clinical symptoms include prolonged fever, spleen enlargement, anemia, emaciation, leukopenia, and increased serum globulin levels. If not appropriately treated, patients may die of complications caused by leishmaniasis within 1–2 years after the onset of the illness. Therefore, further investigation of the mechanisms of infection by this pathogen is required. Here, an epidemiological study of Leishmania carriers was conducted. The potential mechanism of infection through domestic animals as carriers of the parasite was investigated to identify potential reservoir hosts for Leishmania.MethodsThe rK-39 strip test was performed on blood samples from previously infected patients. Blood samples were collected from the patients and their families. The blood, liver, spleen, and diaphragm muscle samples were collected from livestock. To perform nested polymerase chain reaction (PCR), DNA was extracted and the internal transcribed spacer sequence was used. The amplified products were then subjected to restriction fragment length polymorphism and phylogenetic analyses.ResultsAmong previously infected patients, 40% (12/30) showed positive results in the rK-39 strip test. The nested PCR positive rates for previously infected patients/relatives and livestock samples were 86% (77/90) and 80% (8/10), respectively. Moreover, the phylogenetic analysis showed that the pathogen was Leishmania infantum. Dogs, patients, and domesticated animals carrying Leishmania were found to be a potential source of infection for leishmaniasis.ConclusionsThe results of this study provide a basis for developing disease prevention and control strategies for leishmaniasis.

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Genetic Diversity and Population Structure of Plasmodium Falciparum in Nigeria: Insights From Microsatellites Loci Analysis

10.21203/rs.3.rs-90709/v1 ◽

2020 ◽

Author(s):

Fehintola Victoria Ajogbasile ◽

Adeyemi T. Kayode ◽

Kazeem O. Akano ◽

Paul E. Oluniyi ◽

Jessica N. Uwanibe ◽

...

Keyword(s):

Genetic Diversity ◽

Plasmodium Falciparum ◽

Control Strategies ◽

Population Diversity ◽

Parasite Population ◽

Fixation Index ◽

Parasite Diversity ◽

Nested Polymerase Chain Reaction ◽

Public Health Burden ◽

High Level

Abstract BackgroundMalaria remains a public health burden especially in Nigeria. To develop new malaria control and elimination strategies or refine existing ones, understanding parasite population diversity and transmission patterns is crucial. MethodsIn this study, we characterized parasite diversity and structure of Plasmodium falciparum isolates from 633 dried blood spot samples in Nigeria, using 12 microsatellite loci of P. falciparum. These microsatellites were amplified via semi-nested polymerase chain reaction (PCR) and fragments were analyzed using GeneMapper and GENALEX 6.5.ResultsEstimates of parasite diversity such as Mean complexity of infection (range: 1.71-2.66) and Expected heterozygosity (range: 0.76-0.82) were high, while parasite population sub-structuring was low (Analysis of molecular variance= 0.039, Fixation index= 0.038 and Linkage disequilibrium= 0.0219). Conclusion We conclude that the high level of genetic diversity and low population structuring in this study suggests that parasite populations circulating in Nigeria are homogenous. This implies that a uniform control strategy will be effective across the six geographical zones of Nigeria. The results obtained can be used as a baseline for parasite diversity and structure, aiding in the formulation of appropriate therapeutic and control strategies in Nigeria.

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High genetic diversity of Anaplasma marginale infecting dairy cattle in northeastern Brazil

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-29612021097 ◽

2021 ◽

Vol 30 (4) ◽

Author(s):

José Gomes Pereira ◽

Amanda Barbosa Garcia ◽

Luiz Ricardo Gonçalves ◽

Inalda Angélica de Souza Ramos ◽

Maria do Socorro Costa Oliveira Braga ◽

...

Keyword(s):

Genetic Diversity ◽

Dairy Cattle ◽

Anaplasma Marginale ◽

The State ◽

Amino Acid Sequences ◽

Surface Proteins ◽

Northeastern Brazil ◽

High Genetic Diversity ◽

Blood Samples ◽

Pcr Targeting

Abstract Anaplasma marginale is an obligate intracellular Gram-negative bacterium found in ruminants’ erythrocytes and is the etiological agent of bovine anaplasmosis. The bacterium’s genetic diversity has been characterized based on sequences of major surface proteins (MSPs), such as MSP1α. The aim of the present study was to investigate the genetic diversity of A. marginale in cattle in the state of Maranhão, northeastern Brazil. To this end, 343 blood samples were harvested and subjected to iELISA assays using the recombinant surface protein MSP5. Out of 343 blood samples, 235 (68.5%) were randomly chosen and submitted to DNA extraction, qPCR and conventional PCR targeting the msp1α gene to determine amino acid sequences and classify the genotypes. The iELISA results showed 81.34% seropositivity (279/343), whereas qPCR revealed 224 positive samples (95.32%). Among these qPCR-positive samples, 67.4% (151/224) were also positive in the cPCR. Among the 50 obtained sequences, 21 strains had not been previously reported. Regarding the genotypes, H (26/50) and E (18/50) were identified most often, while genotypes F and C were only identified twice each and B and G once each. In conclusion, high prevalence and genetic diversity for A. marginale were observed in dairy cattle herds in the state of Maranhão.

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GnRH-1, GnIH mRNA and Luteinizing Hormone in Domestic hens (Gallus gallus domesticus) Exposed to Different Wavelengths of light

International Journal of Bioassays ◽

10.21746/ijbio.2017.08.001 ◽

2017 ◽

Vol 6 (8) ◽

pp. 5446

Author(s):

Reddy I.J. ◽

Ashish Mishra ◽

Mondal S.

Keyword(s):

Luteinizing Hormone ◽

Mrna Expression ◽

Egg Production ◽

Experimental Period ◽

Treated Group ◽

Lower Number ◽

Gallus Gallus Domesticus ◽

Blood Samples ◽

Mrna Concentration ◽

Normal Spectrum

The objective of this study was to establish the effects of red spectrum of light (650nm, treated n=12) and normal spectrum of light (450nm control=12) on GnRH-I and GnIH mRNA expression, amplitude and frequency of luteinizing hormone (LH) and egg production from 42 to 52 weeks of age in white leghorn hens. Blood samples were collected at weekly interval from both the groups. At the 47th week of age blood samples from both the groups were collected at every 3 h for 36h to study the pulsatile secretion of LH surges. GnRH and GnIH mRNA expression pattern was studied between control and treated birds. Egg production and pause days were calculated between the two groups. LH concentration in the plasma was increased significantly (P<0.01) in hens exposed to red spectrum of light. Plasma LH concentration was higher (P<0.01) in treated birds with more number of LH surges. The amplitude and frequencies of LH were advanced in birds exposed to red spectrum of light during 36 h of sampling at 3h intervals. GnRH-I mRNA concentration was significantly (P<0.01) higher, whereas GnIH mRNA was significantly (P<0.01) lower in birds exposed to red spectrum of light compared to controls. It is hypothesized that exposure of birds to red spectrum of light enhanced (P<0.01) GnRH-I mRNA, along with LH required for ovulation and egg lay. During 77 days (42-52 weeks of age) of the experimental period, egg production was increased (p<0.01) with lower incidence of pause days in the treated group. It is concluded that low GnIH mRNA and higher levels of GnRH-I mRNA, LH, lower number of pause days enabled the birds to lay more eggs by stimulating GnRH through red spectrum of light.

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Estimating asymptomatic, undetected and total cases for the COVID-19 outbreak in Wuhan: a mathematical modeling study

BMC Infectious Diseases ◽

10.1186/s12879-021-06078-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Xi Huo ◽

Jing Chen ◽

Shigui Ruan

Keyword(s):

Disease Transmission ◽

Large Scale ◽

Transmission Rate ◽

Control Strategies ◽

Herd Immunity ◽

Antibody Prevalence ◽

Screening Process ◽

Vaccination Programs ◽

Prevalence Level ◽

The Impact

Abstract Background The COVID-19 outbreak in Wuhan started in December 2019 and was under control by the end of March 2020 with a total of 50,006 confirmed cases by the implementation of a series of nonpharmaceutical interventions (NPIs) including unprecedented lockdown of the city. This study analyzes the complete outbreak data from Wuhan, assesses the impact of these public health interventions, and estimates the asymptomatic, undetected and total cases for the COVID-19 outbreak in Wuhan. Methods By taking different stages of the outbreak into account, we developed a time-dependent compartmental model to describe the dynamics of disease transmission and case detection and reporting. Model coefficients were parameterized by using the reported cases and following key events and escalated control strategies. Then the model was used to calibrate the complete outbreak data by using the Monte Carlo Markov Chain (MCMC) method. Finally we used the model to estimate asymptomatic and undetected cases and approximate the overall antibody prevalence level. Results We found that the transmission rate between Jan 24 and Feb 1, 2020, was twice as large as that before the lockdown on Jan 23 and 67.6% (95% CI [0.584,0.759]) of detectable infections occurred during this period. Based on the reported estimates that around 20% of infections were asymptomatic and their transmission ability was about 70% of symptomatic ones, we estimated that there were about 14,448 asymptomatic and undetected cases (95% CI [12,364,23,254]), which yields an estimate of a total of 64,454 infected cases (95% CI [62,370,73,260]), and the overall antibody prevalence level in the population of Wuhan was 0.745% (95% CI [0.693%,0.814%]) by March 31, 2020. Conclusions We conclude that the control of the COVID-19 outbreak in Wuhan was achieved via the enforcement of a combination of multiple NPIs: the lockdown on Jan 23, the stay-at-home order on Feb 2, the massive isolation of all symptomatic individuals via newly constructed special shelter hospitals on Feb 6, and the large scale screening process on Feb 18. Our results indicate that the population in Wuhan is far away from establishing herd immunity and provide insights for other affected countries and regions in designing control strategies and planing vaccination programs.

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AI-Driven Framework for Recognition of Guava Plant Diseases through Machine Learning from DSLR Camera Sensor Based High Resolution Imagery

Sensors ◽

10.3390/s21113830 ◽

2021 ◽

Vol 21 (11) ◽

pp. 3830

Author(s):

Ahmad Almadhor ◽

Hafiz Tayyab Rauf ◽

Muhammad Ikram Ullah Lali ◽

Robertas Damaševičius ◽

Bader Alouffi ◽

...

Keyword(s):

Machine Learning ◽

High Resolution ◽

Color Difference ◽

Plant Diseases ◽

Economic Losses ◽

Production Loss ◽

Postharvest Diseases ◽

Tropical Regions ◽

Guava Fruit ◽

Tree Classifier

Plant diseases can cause a considerable reduction in the quality and number of agricultural products. Guava, well known to be the tropics’ apple, is one significant fruit cultivated in tropical regions. It is attacked by 177 pathogens, including 167 fungal and others such as bacterial, algal, and nematodes. In addition, postharvest diseases may cause crucial production loss. Due to minor variations in various guava disease symptoms, an expert opinion is required for disease analysis. Improper diagnosis may cause economic losses to farmers’ improper use of pesticides. Automatic detection of diseases in plants once they emerge on the plants’ leaves and fruit is required to maintain high crop fields. In this paper, an artificial intelligence (AI) driven framework is presented to detect and classify the most common guava plant diseases. The proposed framework employs the ΔE color difference image segmentation to segregate the areas infected by the disease. Furthermore, color (RGB, HSV) histogram and textural (LBP) features are applied to extract rich, informative feature vectors. The combination of color and textural features are used to identify and attain similar outcomes compared to individual channels, while disease recognition is performed by employing advanced machine-learning classifiers (Fine KNN, Complex Tree, Boosted Tree, Bagged Tree, Cubic SVM). The proposed framework is evaluated on a high-resolution (18 MP) image dataset of guava leaves and fruit. The best recognition results were obtained by Bagged Tree classifier on a set of RGB, HSV, and LBP features (99% accuracy in recognizing four guava fruit diseases (Canker, Mummification, Dot, and Rust) against healthy fruit). The proposed framework may help the farmers to avoid possible production loss by taking early precautions.

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Salmonella Bacterin Vaccination Decreases Shedding and Colonization of Salmonella Typhimurium in Pigs

Microorganisms ◽

10.3390/microorganisms9061163 ◽

2021 ◽

Vol 9 (6) ◽

pp. 1163

Author(s):

Eduarda Alexandra Gonçalves de Oliveira Moura ◽

Daniela Gomes da Silva ◽

Caio Henrique Turco ◽

Thainara Vitoria Carnevalli Sanches ◽

Gabriel Yuri Storino ◽

...

Keyword(s):

Salmonella Typhimurium ◽

Blood Count ◽

Control Strategies ◽

Control Group ◽

Blood Samples ◽

Commercial Vaccine ◽

Serum Igg ◽

And Control ◽

Experimental Group ◽

Over Time

Since the occurrence of swine salmonellosis has increased over time and control strategies other than biosecurity are highly recommended, the present study aimed to evaluate the efficacy of vaccination with Salmonella Choleraesuis and Salmonella Typhimurium bacterins in pigs. Two experimental groups were formed: G1, animals immunized with two doses of a commercial vaccine (n = 20); G2, control group (n = 20). After vaccination, all pigs were orally challenged (D0) with 108 CFU of Salmonella Typhimurium and evaluated for 40 days. Every 10 days after D0, five piglets from each experimental group were euthanized and submitted to the necroscopic examination, when organ samples were collected. Blood samples and rectal swabs were collected before the first dose of the vaccine (D−42), before the second dose (D−21), before the challenge (D0), and thereafter, every three days until D39. Blood count, serum IgG measurement by ELISA, and the excretion of Salmonella Typhimurium in feces were evaluated. While the results from blood count and serum IgG concentration did not differ, the detection and excretion of Salmonella between G1 and G2 differed (p < 0.05). Therefore, it was observed that this vaccine partially protected the animals against experimental infection with Salmonella Typhimurium, reducing the excretion of bacteria in feces.

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