Recombinant cold shock domain containing protein is a potential antigen to detect specific antibody during early and late infections of Haemonchus contortus in goat

Abstract Background: Haemonchus contortus (H. contortus) is the most abundant nematode causing haemonchosis with major economic losses to the small ruminant industry farming worldwide. Effective prognosis and treatment depend upon the early diagnosis of H. contortus infection. To date, no widely-approved methods are available to identify prepatent H. contortus infection. The aim of this study was to evaluate the diagnostic potential of recombinant cold shock H. contortus protein (rHc-CS) during early and late infections of H .contortus in goat. Results: Purified rHc-CS exhibited a clear band, with a molecular weight about 38 kDa. No eggs of H. contortus were detected in feces collected at 14 days post infection. However, Specific anti rHc-CS antibodies were detectable in sera of all infected goats during early stage (2nd week of infection) and late stage (3rd to 14th week of infection) using immunoblotting assay. Furthermore, no cross reactivity was observed against most commonly found pathogens (Trichinella spiralis, Fasciola hepatica, and Toxoplasma gondii) and uninfected goats. The format variables for rHc-CS indirect-ELISA were optimized. The optimum antigen coating concentration was found 0.28μg/well at 37℃ 1h and overnight at 4°C. Optimum dilution ratio of serum and rabbit anti-goat IgG was recorded 1:100 and 1:4000 respectively. The best blocking buffer was 5% bovine serum albumin (BSA) and the best time for blocking, serum incubation and TMB reaction was recorded as 60, 120 and 10 minutes respectively. The cut-off value for positive and negative interpretation was determined as 0.352 (OD450). The diagnostic specificity and sensitivity of the rHc-CS, both were recorded 100%. Conclusion: These results demonstrated that rHc-CS is a potential immunodiagnostic antigen to detect specific antibodies at early and late H. contortus infections in goat.

Download Full-text

Recombinant cold shock domain containing protein is a potential antigen to detect specific antibody during early and late infections of Haemonchus contortus in goat

10.21203/rs.2.12443/v4 ◽

2020 ◽

Author(s):

Muhammad Ali-ul-Husnain Naqvi ◽

KaLiBiXiaTi Aimulajiang ◽

Muhammad Ali Memon ◽

Muhammad Waqqas Hasan ◽

Sana Zahra Naqvi ◽

...

Keyword(s):

Haemonchus Contortus ◽

Cold Shock ◽

Fasciola Hepatica ◽

Trichinella Spiralis ◽

Early Stage ◽

Cross Reactivity ◽

Antibody Detection ◽

Economic Losses ◽

Diagnostic Potential ◽

Specificity And Sensitivity

Abstract Background : Haemonchus contortus ( H. contortus ) is one of the most important parasites that cause huge economic losses to small ruminant industry worldwide. Effective prognosis and treatment depend upon the early diagnosis of H. contortus infection. To date, no widely-approved methods for the identification of prepatent H. contortus infection are available to identify prepatent H. contortus infection. The aim of this study was to evaluate the diagnostic potential of recombinant cold shock H. contortus protein (rHc-CS) during early and late infections of H. contortus in goat. Results : Purified rHc-CS exhibited a clear band, with a molecular weight about 38 kDa. H. contortus eggs were not detected by fecal egg count technique from feces collected at 0 to 14 days post infection (D.P.I). However, eggs were detected at 21, 28 and 35 D.P.I. Hence, results of immunoblotting assay showed specific anti rHc-CS antibody detection in all goat sera collected at early stage (14 D.P.I) and late stage (21-103 D.P.I) of H. contortus infection. Furthermore, no cross reactivity was observed against Trichinella spiralis , Fasciola hepatica and Toxoplasma gondii or uninfected goats. Among several evaluated rHc-CS indirect-ELISA format variables, favorable antigen coating concentration was found 0.28μg/well at 37℃ 1h and overnight at 4°C. Moreover, optimum dilution ratio of serum and rabbit anti-goat IgG was recorded as 1:100 and 1:4000, respectively. The best blocking buffer was 5% Bovine Serum Albumin (BSA) while the best time for blocking, serum incubation and TMB reaction were recorded as 60, 120 and 10 min, respectively. The cut-off value for positive and negative interpretation was determined as 0.352 (OD 450 ). The diagnostic specificity and sensitivity of the rHc-CS, both were recorded as 100%. Conclusion : These results validated that rHc-CS is a potential immunodiagnostic antigen to detect the specific antibodies during early and late H. contortus infections in goat.

Download Full-text

Recombinant cold shock domain containing protein is a potential antigen to detect specific antibody during early and late infections of Haemonchus contortus in goat

10.21203/rs.2.12443/v2 ◽

2019 ◽

Author(s):

Muhammad Ali-ul-Husnain Naqvi ◽

KaLiBiXiaTi Aimulajiang ◽

Muhammad Ali Memon ◽

Muhammad Waqqas Hasan ◽

Sana Zahra Naqvi ◽

...

Keyword(s):

Post Infection ◽

Haemonchus Contortus ◽

Cold Shock ◽

Fasciola Hepatica ◽

Trichinella Spiralis ◽

Early Stage ◽

Cross Reactivity ◽

Economic Losses ◽

Diagnostic Potential ◽

Specificity And Sensitivity

Abstract Background: Haemonchus contortus (H. contortus) is the most abundant nematode causing haemonchosis with major economic losses to the small ruminant industry farming worldwide. Effective prognosis and treatment depend upon the early diagnosis of H. contortus infection. To date, no widely-approved methods are available to identify prepatent H. contortus infection. The aim of this study was to evaluate the diagnostic potential of recombinant cold shock H. contortus protein (rHc-CS) during early and late infections of H .contortus in goat. Results: Purified rHc-CS exhibited a clear band, with a molecular weight about 38 kDa. Fecal egg count technique was unable to detect H. contortus eggs in feces collected between 0 and 14 days post infection. Eggs were detected at 21, 28 and 35 days post infection. However, Specific anti rHc-CS antibodies were detectable in sera of all infected goats during early stage (2nd week of infection) and late stage (3rd to 14th week of infection) using immunoblotting assay. Furthermore, no cross reactivity was observed against most commonly found helminths (Trichinella spiralis, Fasciola hepatica, and Toxoplasma gondii) and uninfected goats. The format variables for rHc-CS indirect-ELISA were optimized. The optimum antigen coating concentration was found 0.28μg/well at 37℃ 1h and overnight at 4°C. Optimum dilution ratio of serum and rabbit anti-goat IgG was recorded 1:100 and 1:4000 respectively. The best blocking buffer was 5% bovine serum albumin (BSA) and the best time for blocking, serum incubation and TMB reaction was recorded as 60, 120 and 10 minutes respectively. The cut-off value for positive and negative interpretation was determined as 0.352 (OD450). The diagnostic specificity and sensitivity of the rHc-CS, both were recorded 100%. Conclusion: These results demonstrated that rHc-CS is a potential immunodiagnostic antigen to detect specific antibodies at early and late H. contortus infections in goat.

Download Full-text

Recombinant cold shock domain containing protein is a potential antigen to detect specific antibody during early and late infections of Haemonchus contortus in goat

10.21203/rs.2.12443/v3 ◽

2019 ◽

Author(s):

Muhammad Ali-ul-Husnain Naqvi ◽

KaLiBiXiaTi Aimulajiang ◽

Muhammad Ali Memon ◽

Muhammad Waqqas Hasan ◽

Sana Zahra Naqvi ◽

...

Keyword(s):

Haemonchus Contortus ◽

Cold Shock ◽

Fasciola Hepatica ◽

Trichinella Spiralis ◽

Early Stage ◽

Cross Reactivity ◽

Antibody Detection ◽

Economic Losses ◽

Diagnostic Potential ◽

Specificity And Sensitivity

Abstract Background: Haemonchus contortus (H. contortus) is one of the most important parasites that cause huge economic losses to small ruminant industry worldwide. Effective prognosis and treatment depend upon the early diagnosis of H. contortus infection. To date, no widely-approved methods for the identification of prepatent H. contortus infection are available to identify prepatent H. contortus infection. The aim of this study was to evaluate the diagnostic potential of recombinant cold shock H. contortus protein (rHc-CS) during early and late infections of H. contortus in goat. Results: Purified rHc-CS exhibited a clear band, with a molecular weight about 38 kDa. H. contortus eggs were not detected by fecal egg count technique from feces collected at 0 to 14 days post infection (D.P.I). However, eggs were detected at 21, 28 and 35 D.P.I. Hence, results of immunoblotting assay showed specific anti rHc-CS antibody detection in all goat sera collected at early stage (14 D.P.I) and late stage (21-103 D.P.I) of H. contortus infection. Furthermore, no cross reactivity was observed against Trichinella spiralis, Fasciola hepatica and Toxoplasma gondii or uninfected goats. Among several evaluated rHc-CS indirect-ELISA format variables, favorable antigen coating concentration was found 0.28μg/well at 37℃ 1h and overnight at 4°C. Moreover, optimum dilution ratio of serum and rabbit anti-goat IgG was recorded as 1:100 and 1:4000, respectively. The best blocking buffer was 5% Bovine Serum Albumin (BSA) while the best time for blocking, serum incubation and TMB reaction were recorded as 60, 120 and 10 min, respectively. The cut-off value for positive and negative interpretation was determined as 0.352 (OD450). The diagnostic specificity and sensitivity of the rHc-CS, both were recorded as 100%. Conclusion: These results validated that rHc-CS is a potential immunodiagnostic antigen to detect the specific antibodies during early and late H. contortus infections in goat.

Download Full-text

Adhesion-Regulating Molecule from Haemonchus contortus: Potential Antigen for Diagnosis of Early Infection in Goats

Pathogens ◽

10.3390/pathogens9010034 ◽

2019 ◽

Vol 9 (1) ◽

pp. 34 ◽

Cited By ~ 3

Author(s):

Kalibixiati Aimulajiang ◽

Muhammad Ali-ul-Husnain Naqvi ◽

Wen Chu ◽

Mingmin Lu ◽

Xiaowei Tian ◽

...

Keyword(s):

Haemonchus Contortus ◽

Fasciola Hepatica ◽

Trichinella Spiralis ◽

Clinical Signs ◽

Serological Diagnosis ◽

Economic Losses ◽

Serum Samples ◽

Fecal Examination ◽

Diagnostic Potential ◽

Blood Sucking

Haemonchus contortus, a blood-sucking nematode of ruminants, causes large economic losses worldwide. Diagnosis of infection mainly depends on the evaluation of clinical signs and fecal examination. However, this has limitations for the diagnosis of early or light infections, where serological diagnosis seems to be more accurate and reliable. In this study, the recombinant H. contortus adhesion-regulating molecule protein (rHCADRM) was expressed and purified, and its diagnostic potential was evaluated. Serum samples from goats experimentally infected with H. contortus (n = 5) were collected at 0 (before infection, negative control), 7, 14, 21, 35, 49, 63, 85, and 103 days post-infection (DPI). The reactions between rHcADRM and goat serum were tested using Western blot (WB) analysis. The results show that rHcADRM can be recognized in the serum as early as 14 DPI, and the antibody against rHcADRM in infected goat could be maintained for over 89 days. No reaction was found between rHcADRM and antibodies against Trichinella spiralis, Fasciola hepatica, or Toxoplasma gondii. An indirect enzyme-linked immune sorbent assay (ELISA) was developed based on rHcADRM. The optimal coating antigen (279 ng of rHcADRM/well) and serum dilutions (1:50) were determined by checkerboard titration. A total of 64 serum samples, including 32 from H. contortus infection goats and 32 from helminth-free goats, were used to determine the positive (0.362) and negative (0.306) cut-off values for the ELISA. The results show this serological diagnosis method is highly sensitive (90.6%) and specific (93.75%). The coefficient of variation within run and between runs was less than 11%. To apply this indirect ELISA during field examination, 51 serum samples were randomly collected from goat farms and tested using this method. The result showed that 19.6% (10/51) of goats were infected with H. contortus, which was 100% consistent with the necropsy result, higher than that of fecal examination (15.7%, 8/51). These results indicate that rHcADRM could be a potential antigen for diagnosis of H. contortus infection in goats.

Download Full-text

Development and Potential Application of Ras Domain Containing Protein from Haemonchus contortus for Diagnosis of Goat Infection

Animals ◽

10.3390/ani10010138 ◽

2020 ◽

Vol 10 (1) ◽

pp. 138 ◽

Cited By ~ 2

Author(s):

Kalibixiati Aimulajiang ◽

Man Cao ◽

Shuyi Liao ◽

Muhammad Ali-ul-Husnain Naqvi ◽

Xiaowei Tian ◽

...

Keyword(s):

Haemonchus Contortus ◽

Indirect Elisa ◽

Fasciola Hepatica ◽

Trichinella Spiralis ◽

Clinical Signs ◽

Small Ruminants ◽

Gastrointestinal Nematode ◽

Enzyme Linked Immunosorbent Assay ◽

Fecal Examination ◽

Diagnostic Potential

Haemonchus contortus is an important gastrointestinal nematode of small ruminants that causes significant mortality in goats worldwide. Diagnosis of this infection mainly depends on the evaluation of clinical signs and fecal examination. However, limitations often occur in early or mild infections. For this purpose, serological diagnosis seems to be more accurate and reliable. Ras domain-containing protein (Ras) is one of H. contortus’s excretory and secretory products (ESPs) that can be isolated from different larval stages of the nematode. In this study, the recombinant H. contortus Ras domain-containing protein (rHcRas) was expressed and purified and its diagnostic potential was evaluated. Reactions between rHcRas and goat sera were tested using Western blotting (WB). The results showed that rHcRas could be recognized by sera as early as 14 days post infection (DPI), and antibodies against rHcRas in infected goats could be maintained for over 89 days. No reaction was found between rHcRas and antibodies against Trichinella spiralis, Fasciola hepatica, or Toxoplasma gondii. An indirect enzyme-linked immunosorbent assay (ELISA) was produced based on rHcRas. The optimal coating antigen (157 ng of rHcRas/well) and serum dilutions (1:50) were determined via checkerboard titration. Indirect ELISA based on rHcRas showed 87.5% sensitivity and 90.6% specificity. The cut-off values for this experiment were determined to be 0.324 (positive) and 0.273 (negative), respectively, and the variation coefficient (CV) was less than 15%. The results of the indirect ELISA in-field examination showed that 17.6% (9/51) of the goats were infected with H. contortus, higher than the fecal examination results (15.7%, 8/51). When compared the results of the indirect ELISA and necropsy testing, 98.0% (50/51) consistency was found. These results indicated that rHcRas was a potential antigen for the diagnosis of H. contortus infection in goats.

Download Full-text

Combined Use of Indirect ELISA and Western Blotting with Recombinant Hepatocellular Carcinoma-Associated Antigen 59 Is a Potential Immunodiagnostic Tool for the Detection of Prepatent Haemonchus contortus Infection in Goat

Animals ◽

10.3390/ani9080548 ◽

2019 ◽

Vol 9 (8) ◽

pp. 548 ◽

Cited By ~ 7

Author(s):

Muhammad Ali-ul-Husnain Naqvi ◽

Sana Zahra Naqvi ◽

Muhammad Ali Memon ◽

Kalibixiati Aimulajiang ◽

Muhammad Haseeb ◽

...

Keyword(s):

Western Blot ◽

Western Blotting ◽

Haemonchus Contortus ◽

Indirect Elisa ◽

Fasciola Hepatica ◽

False Negative ◽

Cross Reactivity ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Combined Use

Haemonchus contortus is recognized as one of the important health problems in small ruminants, leading to reduced production and economic loss for farmers worldwide. Prepatent diagnosis of H. contortus infection is crucial to improve control strategies as this helminth may remove up to one-fifth of total erythrocytes and may cause anemia, edema, diarrhea, and ultimately death in young animals. In this study, one of the excretory and secretory products, rHc-HCA59, was purified and used as antigen to detect specific antibodies in H. contortus infected goats during prepatent stage of infection using indirect enzyme linked immunosorbent assay (ELISA) as screening test. All goats (n = 38) were housed indoor, experimentally infected with 8000 infective larvae (L3) of H. contortus, and serum samples were collected prior to infection and at 14th day of infection. Immunoblotting was performed to confirm the results of indirect ELISA, evaluate the cross reactivity against rHc-HCA59 in sera of most common co-infecting parasites and rectify the false negative samples. Furthermore, three different batches of rHc-HCA59 were produced to evaluate the repeatability of ELISA. No eggs were detected in feces of all goats collected at 7th and 14th day of infection but, H. contortus eggs were detected at 21 days post infection in the feces. Indirect ELISA performed in this study showed 87% sensitivity and 100% specificity. The western blot analysis confirmed immunoreactivity in serum samples which scored positive in indirect ELISA and recognized the samples as negative which had OD450 lower than negative cut-off value in indirect ELISA. Furthermore, all false negative sera (n = 5) that had OD450 value between positive and negative cut-off value in rHc-HCA59 based ELISA were clearly positive in western blot. Moreover, no cross-reactivity was detected in ELISA and western blotting against rHc-HCA59 in positive sera of Toxoplasma gondii, Fasciola hepatica, and Trichinella spiralis. The results of this study concluded that combined use of indirect ELISA and western blotting with rHc-HCA59 is a potential immunodiagnostic tool for the detection of H. contortus infection during prepatent period in goats.

Download Full-text

Detection of Trichinella-specific IgE in human Trichinellosis: Creating a new test

Journal of the Serbian Chemical Society ◽

10.2298/jsc140402065d ◽

2014 ◽

Vol 79 (12) ◽

pp. 1477-1490 ◽

Cited By ~ 2

Author(s):

Marija Devic ◽

Alisa Gruden-Movsesijan ◽

Ljiljana Sofronic-Milosavljevic

Keyword(s):

Trichinella Spiralis ◽

Time Frame ◽

Specific Ige ◽

Elisa Test ◽

Cross Reactivity ◽

Clinical Criteria ◽

Negative Results ◽

Specificity And Sensitivity ◽

Test Specificity

Trichinellosis is a parasitic disease of humans caused by the nematode from the genus Trichinella, predominantly Trichinella spiralis (T. spiralis). If Trichinella infection is suspected, based on epidemiological link and clinical criteria within defined period of time, then finding of Trichinella-specific antibodies in the examined sera provides a definitive proof of the infection establishment. Detection of Trichinella-specific IgE that could precede, coincide or follow IgG seroconversion not only confirms the infection existence, but could narrow the time frame in which the infection took place to a year or even less. Since there are no commercially available tests for monitoring the Trichinella-specific IgE presence during the course of the disease, our work was aimed to establish this kind of ELISA test. Specificity and sensitivity of so far described Trichinella-specific IgE ELISAs are not satisfying enough; two major problems are poor discrimination between positive and negative results and cross reactivity with sera of patients with different parasitic diseases. In this study, we have developed Trichinella-specific IgE Capture ELISA that overcomes problems with specificity and sensitivity and enables determination of Trichinella-specific IgE.

Download Full-text

Studies on the specific immunodiagnosis of cystic echinococcosis in camels using enzyme-linked immunosorbent assay

BULGARIAN JOURNAL OF VETERINARY MEDICINE ◽

10.15547/bjvm.2136 ◽

2019 ◽

Vol 22 (3) ◽

pp. 305-313 ◽

Cited By ~ 3

Author(s):

O. Kandil ◽

N. Hassan ◽

D. Sedky ◽

E. Beshir Ata

Keyword(s):

Cystic Echinococcosis ◽

Haemonchus Contortus ◽

Indirect Elisa ◽

Cross Reactivity ◽

Economic Losses ◽

Enzyme Linked Immunosorbent Assay ◽

Hydatid Cysts ◽

Germinal Layer ◽

Lung Cysts ◽

Fasciola Spp

Cystic echinococcosis (CE) is of increasing public health and socio-economic concern because of the large morbidity rates and produced high economic losses in the livestock industry. The objective of the current research was to study the reliability of indirect ELISA in detecting CE, based on two dif-ferent types of crude antigens of camel origin; protoscolex and germinal layer antigens from hydatid cyst. Blood samples were collected from 284 (125 slaughtered and 159 live camels). Out of 125 slaughtered camels examined visually, 55 (44%) were found to have hydatid cysts. Of them, 52/125 (41.6%) and 3/125 (2.4%) harboured hydatid cysts in lungs and livers respectively. Fertile lung cysts were 32.8%; 26.9% were sterile, while 40.3% of lung and liver cysts were calcified. The sensitivity of ELISA was 83% and 46.5% when protoscolex and germinal layer antigens were used, respectively. The respective speciﬁcity of antigens of protoscolex and germinal layer was 70.3% and 41.7%. The protoscolex antigen showed higher accuracy (73.6%) compared to the germinal layer antigen (52.8%). The cross reactivity of these antigens were evaluated with antigens and hyperimmune sera of CE and Fasciola spp. and Haemonchus contortus using ELISA. The results showed also weak immunogenic potency of each antigen with Fasciola spp. hyperimmune sera at dilution 1:50 while hyperimmune sera of Haemonchus contortus did not bind any antigen.

Download Full-text

Integration of early disease-resistance phenotyping, histological characterization, and transcriptome sequencing reveals insights into downy mildew resistance in impatiens

Horticulture Research ◽

10.1038/s41438-021-00543-w ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Ze Peng ◽

Yanhong He ◽

Saroj Parajuli ◽

Qian You ◽

Weining Wang ◽

...

Keyword(s):

Disease Resistance ◽

Downy Mildew ◽

Transcriptome Sequencing ◽

Early Stage ◽

Economic Losses ◽

Potential Candidate ◽

Early Disease ◽

True Leaf ◽

Cotyledon Stage ◽

Wide Range

AbstractDowny mildew (DM), caused by obligate parasitic oomycetes, is a destructive disease for a wide range of crops worldwide. Recent outbreaks of impatiens downy mildew (IDM) in many countries have caused huge economic losses. A system to reveal plant–pathogen interactions in the early stage of infection and quickly assess resistance/susceptibility of plants to DM is desired. In this study, we established an early and rapid system to achieve these goals using impatiens as a model. Thirty-two cultivars of Impatiens walleriana and I. hawkeri were evaluated for their responses to IDM at cotyledon, first/second pair of true leaf, and mature plant stages. All I. walleriana cultivars were highly susceptible to IDM. While all I. hawkeri cultivars were resistant to IDM starting at the first true leaf stage, many (14/16) were susceptible to IDM at the cotyledon stage. Two cultivars showed resistance even at the cotyledon stage. Histological characterization showed that the resistance mechanism of the I. hawkeri cultivars resembles that in grapevine and type II resistance in sunflower. By integrating full-length transcriptome sequencing (Iso-Seq) and RNA-Seq, we constructed the first reference transcriptome for Impatiens comprised of 48,758 sequences with an N50 length of 2060 bp. Comparative transcriptome and qRT-PCR analyses revealed strong candidate genes for IDM resistance, including three resistance genes orthologous to the sunflower gene RGC203, a potential candidate associated with DM resistance. Our approach of integrating early disease-resistance phenotyping, histological characterization, and transcriptome analysis lay a solid foundation to improve DM resistance in impatiens and may provide a model for other crops.

Download Full-text

Early Detection of Encroaching Woody Juniperus virginiana and Its Classification in Multi-Species Forest Using UAS Imagery and Semantic Segmentation Algorithms

Remote Sensing ◽

10.3390/rs13101975 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1975

Author(s):

Lin Wang ◽

Yuzhen Zhou ◽

Qiao Hu ◽

Zhenghong Tang ◽

Yufeng Ge ◽

...

Keyword(s):

Early Detection ◽

Early Development ◽

Spatial Resolution ◽

Early Stage ◽

Semantic Segmentation ◽

Development Stage ◽

Unmanned Aircraft ◽

Economic Losses ◽

Juniperus Virginiana ◽

Segmentation Algorithms

Woody plant encroachment into grasslands ecosystems causes significantly ecological destruction and economic losses. Effective and efficient management largely benefits from accurate and timely detection of encroaching species at an early development stage. Recent advances in unmanned aircraft systems (UAS) enabled easier access to ultra-high spatial resolution images at a centimeter level, together with the latest machine learning based image segmentation algorithms, making it possible to detect small-sized individuals of target species at early development stage and identify them when mixed with other species. However, few studies have investigated the optimal practical spatial resolution of early encroaching species detection. Hence, we investigated the performance of four popular semantic segmentation algorithms (decision tree, DT; random forest, RF; AlexNet; and ResNet) on a multi-species forest classification case with UAS-collected RGB images in original and down-sampled coarser spatial resolutions. The objective of this study was to explore the optimal segmentation algorithm and spatial resolution for eastern redcedar (Juniperus virginiana, ERC) early detection and its classification within a multi-species forest context. To be specific, firstly, we implemented and compared the performance of the four semantic segmentation algorithms with images in the original spatial resolution (0.694 cm). The highest overall accuracy was 0.918 achieved by ResNet with a mean interaction over union at 85.0%. Secondly, we evaluated the performance of ResNet algorithm with images in down-sampled spatial resolutions (1 cm to 5 cm with 0.5 cm interval). When applied on the down-sampled images, ERC segmentation performance decreased with decreasing spatial resolution, especially for those images coarser than 3 cm spatial resolution. The UAS together with the state-of-the-art semantic segmentation algorithms provides a promising tool for early-stage detection and localization of ERC and the development of effective management strategies for mixed-species forest management.

Download Full-text