First report of invasive Pomacea snails in Shandong Province / 中国血吸虫病防治杂志

Objective To characterize the species of invasive Pomacea snails that were discovered for the first time in Shandong Province. Methods Pomacea snails samples were collected in the field of Jining City, Shandong Province on October 2021 for morphological identification. Pomacea snails were randomly sampled and genomic DNA was extracted from foot muscle tissues of Pomacea snails for multiplex PCR amplification. The PCR amplification product was sequenced. Then, the sequence was aligned and a phylogenetic tree was created using the software MegAlign 7.1.0. In addition, Angiostongylus cantonensis infection was detected in Pomacea snails with the lung microscopy. Results A total of 104 living Pomacea snails were collected, and all were characterized as Pomacea spp. based on morphological features. Of 12 randomly selected adult Pomacea snails, multiplex PCR assay and sequencing identified eleven snails as P. canaliculata and one as P. maculata. No A. cantonensis infection was detected in 104 Pomacea snails. Conclusion This is the first report of invasive Pomacea snails in Shandong Province, where P. canaliculata and P. maculata are found.

Distribution and suitable habitats of ticks in the Yangtze River Delta urban agglomeration / 中国血吸虫病防治杂志

Objective To investigate the current distribution of ticks and predict the suitable habitats of ticks in the Yangtze River Delta urban agglomeration in 2017, so as to provide insights into tick control and management of tick-borne diseases in these areas. Methods All publications pertaining to tick and pathogen distribution in the Yangtze River Delta urban agglomeration were retrieved, and the geographical location of tick distribution was extracted. The effects of 19 climatic factors on the distribution of ticks were examined using the jackknife method, including the mean temperature of the wettest quarter, precipitation of the coldest quarter, mean temperature of the driest quarter, maximum temperature of the warmest month, precipitation of the driest month, minimal temperature of the coldest month, annual precipitation, mean daily temperature range, precipitation seasonality, annual temperature range, temperature seasonality, annual mean temperature, mean temperature of the warmest quarter, precipitation of the wettest quarter, isothermality, mean temperature of the coldest quarter, precipitation of the wettest month, precipitation of the driest quarter and precipitation of the warmest quarter. The distribution of ticks was analyzed in 2020 using the maximum entropy (MaxEnt) model, and the potential suitable habitats of ticks were predicted in 2070 using the MaxEnt model based on climatic data. Results A total of 380 Chinese and English literatures were retrieved, and 148 tick distribution sites were extracted, with 135 sites included in the subsequent analysis. There were 7 genera (Haemaphysalis, Rhipicephalus, Ixodes, Dermacentor, Boophilus, Hyalomma and Amblyomma) and 27 species of ticks detected in the Yangtze River Delta urban agglomeration. The climatic factors affecting the distribution of ticks in the Yangtze River Delta urban agglomeration mainly included the mean temperature of the wettest quarter and the precipitation of the coldest quarter, with 26.1% and 23.6% contributions to tick distributions. The high-, medium- and low-suitable habitats of ticks were 20 337.08, 40 017.38 km2 and 74 931.43 km2 in the Yangtze River Delta urban agglomeration in 2020, respectively. The climate changes led to south expansion of the suitable habitats of ticks in the Yangtze River Delta urban agglomeration in 2070, and the total areas of suitable habitats of ticks was predicted to increase by 18 100 km2. In addition, the high-, medium- and low-suitable habitats of ticks were predicted to increase to 24 317.84, 45 283.02 km2 and 83 766.38 km2 in the Yangtze River Delta urban agglomeration in 2070, respectively. Conclusions Multiple tick species are widespread in the Yangtze River Delta urban agglomeration, and the future climate changes may lead to expansion of tick distribution in these areas.

Population genetics of invasive Pomacea spp. in Hangzhou City, Zhejiang Province / 中国血吸虫病防治杂志

Objective To investigate the distribution and identify the genetic genetics of invasive Pomacea species in Xihu District, Hangzhou City, so as to understand the spread tendency of Pomacea species. Methods The specimens of Pomacea species were collected from five sites in water systems (lakes, rivers and wetlands) and its costal lands in Xihu District, Hangzhou City in 2017 for morphological identification. Total DNA was isolated from the foot tissues of adult snails for amplification of the COI gene, and haplotype diversity and nucleic acid diversity analyses were performed. In addition, a phylogenetic tree was created based on the haplotype captured from GenBank and those from this study to investigate the phylogenetic relationships. Results Pomacea specimens, which were preliminarily characterized as Pomacea, were found in ponds, rivers and wetlands in Xihu District of Hangzhou City. A total of 16 sequences were captured from the DNA samples of Pomacea specimens, which belonged to 3 haplotypes, including Hap1, Hap2 and Hap3. A high frequency was seen in Hap1 and Hap3, and a low frequency was found in Hap2. The Pomacea specimens collected from the 5 sites in Xihu Districts included P. canaliculata and P. maculate. The Pomacea specimens with a Hap1 had a close genetic relationship with the P. canaliculata from Argentina, Guangdong Province and Hong Kong Special Administrative Region of China, and the Pomacea specimens with a Hap2 had a close genetic relationship with the P. canaliculata from Argentina, Japan and Guangzhou City of Guangdong Province, China, while the Pomacea specimens with a Hap2 had a close genetic relationship with the P. maculate from Argentina and Brazil. Conclusions P. canaliculata and P. maculata are present in Xihu District of Hangzhou City. P. maculata may spread to Xihu District through multiple introductions or water flow.

[Quantitative analysis of gene expression in Pomacea canaliculata infected with Angiostrongylus cantonensis and α - tubulin gene expression in various tissues].

OBJECTIVE: To investigate the expression of some genes in Pomacea canaliculata infected with Angiostrongylus cantonensis, so as to provide insight into the preliminary understanding of the interactions between Angiostrongylus cantonensis and its intermediate host Pomacea canaliculata. METHODS: P. canaliculata was fed with rat faces containing the first-stage larvae of A. cantonensis. Three to five P. canaliculata was sampled 1, 10 days and 20 days after feeding, and the hemolymph, hepatopancreas, kidney, intestinal tract, head-foot and gill tissues were collected, while uninfected P. canaliculata served as controls. Total RNA was extracted from various tissues of P. canaliculata at different time points post-infection, and transcribed reversely into cDNA. Based on previous transcriptome sequencing results, 10 genes associated with immune defense, signal transduction, cell growth and metabolism, stress response were selected, and the gene expression was determined in the hemolymph tissues of P. canaliculata 1, 10 days and 20 days post-infection with A. cantonensis using real-time fluorescent quantitative PCR assay, and the α-tubulin gene expression was quantified in the hepatopancreas, kidney, head-foot, intestinal tract and gill tissues of P. canaliculata infected with A. cantonensis. RESULTS: Higher CELA1 gene expression was detected in the infection group than in the control group 1 (t = 12.32, P < 0.05), 10 days (t = 23.51, P < 0.05) and 20 days post-infection (t = 34.92, P < 0.05), and the CELA1 expression increased with the time of infection. The GST gene expression was (7.26 ± 1.80) times higher in the infection group than in the control group 1 day post-infection, and was significantly lower in the infection group than in the control group 10 days (t = 23.89, P < 0.05) and 20 days post-infection (t = 19.83, P < 0.05). Higher ferritin gene expression was found in the infection group than in the control group 10 days post-infection (t = 32.76, P < 0.05), and higher CRT gene expression was seen in the infection group than in the control group 1 (t = 7.23, P < 0.05), 10 days (t = 5.78, P < 0.05) and 20 days post-infection (t = 6.32, P < 0.05). In addition, the greatest α-tubulin gene expression was observed in the the hepatopancreatic tissues of P. canaliculata (F = 17.58, P < 0.05), and the α-tubulin gene expression altered in various tissues of P. canaliculata post-infection with A. cantonensis, with the most remarkable reduction of α - tubulin gene expression seen in the hepatopancreatic tissues (P < 0.05). CONCLUSIONS: Following A. cantonensis infection in P. canaliculata, the expression of multiple genes is altered, and the expression of α-tubulin gene is inhibited in multiple tissues. The findings provide a basis for the further elucidation of the interactions between P. canaliculata and A. cantonensis.

Quantitative analysis of gene expression in Pomacea canaliculata infected with Angiostrongylus cantonensis and α - tubulin gene expression in various tissues / 中国血吸虫病防治杂志

Objective To investigate the expression of some genes in Pomacea canaliculata infected with Angiostrongylus cantonensis, so as to provide insight into the preliminary understanding of the interactions between Angiostrongylus cantonensis and its intermediate host Pomacea canaliculata. Methods P. canaliculata was fed with rat faces containing the first-stage larvae of A. cantonensis. Three to five P. canaliculata was sampled 1, 10 days and 20 days after feeding, and the hemolymph, hepatopancreas, kidney, intestinal tract, head-foot and gill tissues were collected, while uninfected P. canaliculata served as controls. Total RNA was extracted from various tissues of P. canaliculata at different time points post-infection, and transcribed reversely into cDNA. Based on previous transcriptome sequencing results, 10 genes associated with immune defense, signal transduction, cell growth and metabolism, stress response were selected, and the gene expression was determined in the hemolymph tissues of P. canaliculata 1, 10 days and 20 days post-infection with A. cantonensis using real-time fluorescent quantitative PCR assay, and the α-tubulin gene expression was quantified in the hepatopancreas, kidney, head-foot, intestinal tract and gill tissues of P. canaliculata infected with A. cantonensis. Results Higher CELA1 gene expression was detected in the infection group than in the control group 1 (t = 12.32, P < 0.05), 10 days (t = 23.51, P < 0.05) and 20 days post-infection (t = 34.92, P < 0.05), and the CELA1 expression increased with the time of infection. The GST gene expression was (7.26 ± 1.80) times higher in the infection group than in the control group 1 day post-infection, and was significantly lower in the infection group than in the control group 10 days (t = 23.89, P < 0.05) and 20 days post-infection (t = 19.83, P < 0.05). Higher ferritin gene expression was found in the infection group than in the control group 10 days post-infection (t = 32.76, P < 0.05), and higher CRT gene expression was seen in the infection group than in the control group 1 (t = 7.23, P < 0.05), 10 days (t = 5.78, P < 0.05) and 20 days post-infection (t = 6.32, P < 0.05). In addition, the greatest α-tubulin gene expression was observed in the the hepatopancreatic tissues of P. canaliculata (F = 17.58, P < 0.05), and the α-tubulin gene expression altered in various tissues of P. canaliculata post-infection with A. cantonensis, with the most remarkable reduction of α - tubulin gene expression seen in the hepatopancreatic tissues (P < 0.05). Conclusions Following A. cantonensis infection in P. canaliculata, the expression of multiple genes is altered, and the expression of α-tubulin gene is inhibited in multiple tissues. The findings provide a basis for the further elucidation of the interactions between P. canaliculata and A. cantonensis.

Quantitative analysis of gene expression in Pomacea canaliculata infected with Angiostrongylus cantonensis and α - tubulin gene expression in various tissues / 中国血吸虫病防治杂志

Objective To investigate the expression of some genes in Pomacea canaliculata infected with Angiostrongylus cantonensis, so as to provide insight into the preliminary understanding of the interactions between Angiostrongylus cantonensis and its intermediate host Pomacea canaliculata. Methods P. canaliculata was fed with rat faces containing the first-stage larvae of A. cantonensis. Three to five P. canaliculata was sampled 1, 10 days and 20 days after feeding, and the hemolymph, hepatopancreas, kidney, intestinal tract, head-foot and gill tissues were collected, while uninfected P. canaliculata served as controls. Total RNA was extracted from various tissues of P. canaliculata at different time points post-infection, and transcribed reversely into cDNA. Based on previous transcriptome sequencing results, 10 genes associated with immune defense, signal transduction, cell growth and metabolism, stress response were selected, and the gene expression was determined in the hemolymph tissues of P. canaliculata 1, 10 days and 20 days post-infection with A. cantonensis using real-time fluorescent quantitative PCR assay, and the α-tubulin gene expression was quantified in the hepatopancreas, kidney, head-foot, intestinal tract and gill tissues of P. canaliculata infected with A. cantonensis. Results Higher CELA1 gene expression was detected in the infection group than in the control group 1 (t = 12.32, P < 0.05), 10 days (t = 23.51, P < 0.05) and 20 days post-infection (t = 34.92, P < 0.05), and the CELA1 expression increased with the time of infection. The GST gene expression was (7.26 ± 1.80) times higher in the infection group than in the control group 1 day post-infection, and was significantly lower in the infection group than in the control group 10 days (t = 23.89, P < 0.05) and 20 days post-infection (t = 19.83, P < 0.05). Higher ferritin gene expression was found in the infection group than in the control group 10 days post-infection (t = 32.76, P < 0.05), and higher CRT gene expression was seen in the infection group than in the control group 1 (t = 7.23, P < 0.05), 10 days (t = 5.78, P < 0.05) and 20 days post-infection (t = 6.32, P < 0.05). In addition, the greatest α-tubulin gene expression was observed in the the hepatopancreatic tissues of P. canaliculata (F = 17.58, P < 0.05), and the α-tubulin gene expression altered in various tissues of P. canaliculata post-infection with A. cantonensis, with the most remarkable reduction of α - tubulin gene expression seen in the hepatopancreatic tissues (P < 0.05). Conclusions Following A. cantonensis infection in P. canaliculata, the expression of multiple genes is altered, and the expression of α-tubulin gene is inhibited in multiple tissues. The findings provide a basis for the further elucidation of the interactions between P. canaliculata and A. cantonensis.

[Analysis of research status and hotspots of snail intestinal flora based on bibliometrics].

OBJECTIVE: To understand the current research focus and trends in the field of snail intestinal flora. METHODS: The literature focusing on snail intestinal flora and published from 1998 to 2017 were retrieved from the core database of Web of Science. The quantitative analysis of literature was then conducted by using CiteSpace software based on the bibliometricsmethod.The research trends were then summarized systematically, and the potential research fronts and focuses were explored. RESULTS: Totally 139 articles were identified in the field of snail intestinal flora. The top three countries with highest publications included the United States of American, Brazil, and South Korea; while the top three institutions were Kyung Hee University, Osvaldo Cruz Foundation, and Oxford University. Five terms were identified as the key words in this field, including diversity, cellulose, Achatina fulica, lignocelluloses, and species nova. Meanwhile, 5 critical papers with the citation frequency over 15 were recognized, and 5 study clusters were formed including the application, diversity, and function of intestinal flora, difference of snail source and flora, and newly discovered bacteria in the snail intestine. CONCLUSIONS: The current research focuses on intestinal flora of snails include the diversity, function and application of intestinal flora.

[Quantitative determination of biogenic amine from Biomphalaria glabrata nervous system by UPLC MS/MS].

OBJECTIVE: To establish a method for the quantitative determination of serotonin and dopamine in the nervous system of Biomphalaria glabrata by using ultra high performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC MS/MS) . METHODS: The B. glabrata nervous system was broken in the pure methanol solution after obtaining it by dissecting with microscope. Then, the supernatant containing the target substance after twice high speed centrifugation was got. The extraction was separated on an ACQUITY UPLC BEH Amide column with Waters TQ-XS series mass spectrometry detector, with ESI source and positive electrospray ionization mode when the machine testing. RESULTS: The detection limit of serotonin was 0.03 ng/ml and the limit of quantification was 0.1 ng/ml. The detection limit of dopamine was 0.05 ng/ml and the limit of quantification was 0.15 ng/ml. The recoveries of serotonin ranged from 90.68% to 94.72% over the range of 1 to 40 ng/ml. The recoveries of dopamine ranged from 91.68% to 96.12% over the range of 1.0 ng/ml to 40 ng/ml. CONCLUSIONS: The established UPLC MS/MS method is simple, stable and reproducible. It can be used for the quantitative analysis of serotonin and dopamine in the nervous system of B. glabrata snails.

Analysis of research status and hotspots of snail intestinal flora based on bibliometrics / 中国血吸虫病防治杂志

Objective To understand the current research focus and trends in the field of snail intestinal flora. Methods The literature focusing on snail intestinal flora and published from 1998 to 2017 were retrieved from the core database of Web of Science. The quantitative analysis of literature was then conducted by using CiteSpace software based on the bibliometricsmethod.The research trends were then summarized systematically, and the potential research fronts and focuses were explored. Results Totally 139 articles were identified in the field of snail intestinal flora. The top three countries with highest publications included the United States of American, Brazil, and South Korea; while the top three institutions were Kyung Hee University, Osvaldo Cruz Foundation, and Oxford University. Five terms were identified as the key words in this field, including diversity, cellulose, Achatina fulica, lignocelluloses, and species nova. Meanwhile, 5 critical papers with the citation frequency over 15 were recognized, and 5 study clusters were formed including the application, diversity, and function of intestinal flora, difference of snail source and flora, and newly discovered bacteria in the snail intestine. Conclusion The current research focuses on intestinal flora of snails include the diversity, function and application of intestinal flora.

Analysis of research status and hotspots of snail intestinal flora based on bibliometrics / 中国血吸虫病防治杂志

Objective To understand the current research focus and trends in the field of snail intestinal flora. Methods The literature focusing on snail intestinal flora and published from 1998 to 2017 were retrieved from the core database of Web of Science. The quantitative analysis of literature was then conducted by using CiteSpace software based on the bibliometricsmethod.The research trends were then summarized systematically, and the potential research fronts and focuses were explored. Results Totally 139 articles were identified in the field of snail intestinal flora. The top three countries with highest publications included the United States of American, Brazil, and South Korea; while the top three institutions were Kyung Hee University, Osvaldo Cruz Foundation, and Oxford University. Five terms were identified as the key words in this field, including diversity, cellulose, Achatina fulica, lignocelluloses, and species nova. Meanwhile, 5 critical papers with the citation frequency over 15 were recognized, and 5 study clusters were formed including the application, diversity, and function of intestinal flora, difference of snail source and flora, and newly discovered bacteria in the snail intestine. Conclusion The current research focuses on intestinal flora of snails include the diversity, function and application of intestinal flora.

Quantitative determination of biogenic amine from Biomphalaria glabrata nervous system by UPLC MS/MS / 中国血吸虫病防治杂志

Objective To establish a method for the quantitative determination of serotonin and dopamine in the nervous sys-tem of Biomphalaria glabrata by using ultra high performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC MS/MS). Methods The B.glabrata nervous system was broken in the pure methanol solution after obtaining it by dis-secting with microscope.Then,the supernatant containing the target substance after twice high speed centrifugation was got.The extraction was separated on an ACQUITY UPLC BEH Amide column with Waters TQ-XS series mass spectrometry detector, with ESI source and positive electrospray ionization mode when the machine testing. Results The detection limit of serotonin was 0.03 ng/ml and the limit of quantification was 0.1 ng/ml.The detection limit of dopamine was 0.05 ng/ml and the limit of quantification was 0.15 ng/ml.The recoveries of serotonin ranged from 90.68% to 94.72% over the range of 1 to 40 ng/ml.The re-coveries of dopamine ranged from 91.68% to 96.12% over the range of 1.0 ng/ml to 40 ng/ml. Conclusion The established UPLC MS/MS method is simple,stable and reproducible.It can be used for the quantitative analysis of serotonin and dopamine in the nervous system of B.glabrata snails.

[Diffusion, population dynamics and potential distribution of Armigeres subalbatus].

OBJECTIVE: To investigate the diffusion trend of Armigeres subalbatus and analyze its potential geographic distribution in China. METHODS: The trend analysis of diffusion and population dynamics were carried out based on three aspects including literature reports, information of museum specimens and new collection records from our field survey. To compare the potential geographic distribution, two ecological niche models were constructed by Maxent software based on the geographic presence occurrence data and 20 environmental variables. The final models were evaluated with the receiver operating characteristics curve (ROC). The analyses of variable contributions were confirmed by using the Jackknife method. RESULTS: The populations in Weifang and Weihai, Shandong Province were reported for the first time. The results showed that this species was spread to the Palaearctic Northern Region and reached 42° north latitude regions. In some areas, it gradually developed into a dominant species. A total of 294 georeferenced occurrence points of A. subalbatus were found out. Two predictions of Maxent models were established based on the presence occurrence data in 2000 and 2016, respectively. The results showed that the current distribution range of A. subalbatus had been significantly northward expanded compared with 2000. It means that the potential suitable area gradually spread northward. The ROC analysis results showed the AUC values were 0.980 and 0.982, and it indicated that the models had a high reliability. The Jackknife method displayed that the precipitation of warmest quarter, precipitation of wettest month and precipitation of wettest quarter were the dominant environmental variables that mainly contributed to the distribution of A. subalbatus. CONCLUSIONS: A. subalbatus distribution gradually spreads northward, and climate warming is probably the main reason for the diffusion. It could affect the local mosquito species composition and increase the risk of mosquito-borne disease transmission.

[Identification of two Bithynia species from Heng County, Guangxi Zhuang Autonomous Region, China by using morphological and DNA barcoding methods].

OBJECTIVE: To distinguish two Bithynia species, Bithynia fuchsiana and Bithynia robusta collected from Heng County, Guangxi Zhuang Autonomous Region, by using morphological and DNA barcoding methods. METHODS: The adult B. fuchsiana and B. robusta were collected from the biotope such as rivers, ditches and ponds in Heng County of Guangxi Zhuang Autonomous Region, China. The two species specimens were identified by measuring shell morphological parameters, comparing the characters of the male reproductive system, and using the COI gene barcoding technique and building phylogenetic tree. RESULTS: B. fuchsiana and B. robusta were similar morphologically in the shell appearance; they had the similar snail height, snail width, shape and male reproductive structure. The DNA sequence analysis showed that the COI gene of the two Bithynia species had low sequence divergence with 11 variation sites among 22 sequences. The length of the COI gene segment was 517 bp and no insertion sites and deletion loci after sequence edited. All individuals of the two species gathered to one clade in the phylogenetic tree based on COI gene. CONCLUSIONS: According to the evidence of morphology and COI gene coding sequence, B. fuchsiana and B. robusta from Heng County, Guangxi Zhuang Autonomous Region, are likely to be the same species.