A cyclic dipeptide for salinity stress alleviation and the trophic flexibility of endophyte provide insights into saltmarsh plant-microbe interactions.

In response to climate change, the nature of endophytes and their applications in sustainable agriculture have attracted the attention of academics and agro-industries. This work focused on the endophytic halophiles of the endangered Taiwanese salt marsh plant, Bolboschoenus planiculmis, and evaluated the functions of these isolates through in planta salinity stress alleviation assay using Arabidopsis. The endophytic strain Priestia megaterium BP01R2, which can promote plant growth and salinity tolerance, was further characterized through multi-omics approaches. The transcriptomics results suggested that BP01R2 could function by tuning hormone signal transduction, energy-producing metabolism, multiple stress responses, etc. In addition, the cyclodipeptide cyclo(L-Ala-Gly), which was identified by metabolomics analysis, was confirmed to contribute to the alleviation of salinity stress in stressed plants via exogenous supplementation. In this study, we used multi-omics approaches to investigate the genomics, metabolomics, and tropisms of endophytes, as well as the transcriptomics of plants in response to the endophyte. The results revealed the potential molecular mechanisms underlying the occurrence of biostimulant-based plant-endophyte symbioses with possible application in sustainable agriculture.

Spatial distribution and habitat suitability of Biomphalaria straminea, intermediate host of Schistosoma mansoni, in Guangdong, China.

BACKGROUND: Biomphalaria straminea is an invasive vector in China, posing a significant threat to public health. Understanding the factors affecting the establishment of this snail is crucial to improve our ability to manage its dispersal and potential risk of schistosomiasis transmission. This study sought to determine the spatial distribution of B. straminea in mainland China and whether environmental factors were divergent between places with and without B. straminea. METHODS: A malacological survey of B. straminea was conducted in Guangdong Province, China. Snails were identified using anatomical keys. Water and sediment samples were taken, and their physicochemical properties were analyzed using national standard methods. Landscape and climatic variables were also collected for each site. We compared the environmental characteristics between sites with and without B. straminea using Mann-Whitney U test. We further used generalized linear mixed models to account for seasonal effects. RESULTS: B. straminea was found at six sites, including one in Dongguan and five in Shenzhen. Probability map found a hot spot of B. straminea distribution at Shenzhen and Hong Kong. Sites occupied by B. straminea were characterized by higher median altitude, mean annual precipitation and moderate temperature. Water with snails had higher median concentrations of total nitrogen, nitrate and nitrites, ammoniacal nitrogen, calcium, zinc and manganese but lower dissolved oxygen and magnesium. Sediments with snails had higher median copper, zinc and manganese. B. straminea was associated with maximum temperature of the warmest month (pMCMC < 0.001) and sediment zinc (pMCMC < 0.001). CONCLUSIONS: B. straminea is distributed in Shenzhen and its surrounding areas in Guangdong, China. Sites with and without B. straminea differed in the maximum temperature of the warmest month and sediment zinc. Surveillance should be continued to monitor the dispersal of this snail in China.

[Distribution and schistosomiasis transmission risks of Biomphalaria straminea in inland China].

Biomphalaria straminea, the intermediary host of Schistosoma mansoni, was found by survey in local areas of Shenzhen City in 1981, which was the first finding of the snail in inland China. By 2013, the snail had spread in large range of Shenzhen City and overspread to the surrounding regions, Dongguan City and Huizhou City. Due to the facts that Shenzhen City has many international communications and is a key area of labor export, with high population mobility, while the reports of S. mansoni infection in the returnees of our country from Africa have been increasing recently, it must be paid a high attention to whether the epidemic or transmission of schistosomiasis mansoni may happen under the present circumstance. This paper initially discusses the finding, distribution, spreading and overspreading and transmission risk of B. straminea in inland China and puts forward some related control suggestions.

[Survey of distribution of Enterobius vermicularis infection of children in Huadu District, Guangzhou City].

OBJECTIVE: To understand the status of Enterobius vermicularis infection of children in Huadu District, Guangzhou City so as to provide the evidence for improving the control work. METHODS: In 2012, 24 kindergartens and 24 primary schools were selected as survey sites by the stratified random sampling method and 200 or more children aged below 10 years per site were investigated for the Enterobius vermicularis infection by the cellophane tape method. The relevant influencing factors (environment conditions, sanitary facilities and management system, and health habits of families and individuals) were surveyed with questionnaire, and all the data were analyzed statistically with the Excel software. RESULTS: From September to December, 2012, totally 9 777 children were investigated and 760 ones were detected with Enterobius vermicularis infection (7.77%). With a school as the unit, the highest infection rate reached to 33.82% (69/204). The infection rate in urban areas was 4.63% (195/ 4 213), and the rate in villages was 10.15% (760/5 546) ( chi2 =102.126, P <0.01). The infection rate of preschool children was 3.51% (1 70/4 840) and the rate of school children was 11.95% (590/4 973), and the latter was much higher than the former (chi2 =242.732, P < 0.01). The infection rates of the male and the female were 7.44% (412/5 537) and 8.21% (348/4, 240) respectively ( chi2 = 1.969, P > 0.05). The survey of relevant influencing factors showed that the conditions of the kindergartens were better than those in the primary schools, and the conditions in the urban areas were better than those in the villages. CONCLUSIONS: The Enterobius vermicularis infection of children in Huadu District is high. The control key points should be put on the schools with poor sanitary facilities and environment conditions in villages and urban areas.

First provincial survey of Angiostrongylus cantonensis in Guangdong Province, China.

The rat lungworm Angiostrongylus cantonensis is a zoonotic nematode with a wide distribution. We report the first provincial survey of the prevalence of A. cantonensis infection among wild rodents and snails in Guangdong Province, China. A total of 2929 Pomacea canaliculata and 1354 Achatina fulica were collected from fields in 22 survey sites with a larval infection rates ranging from 0-26.6% to 0-45.4%. In addition, 114 Cipangopaludina sp and 252 Bellamya sp were bought from markets; larvae were found only in Bellamya snails from two survey sites with an infection rate of 1.4% (1/70) and 3.3% (3/91), respectively. Four hundred and ninety-one rodents were captured in nine sites (Rattus norvegicus, R. flavipectus, Suncus murinus, Mus musculus, Bandicota indica, R. losea and R. rattus). Adult worms were found in R. norvegicus, R. flavipectus and Bandicota indica. Our survey revealed a wide distribution of A. cantonensis and its intermediate hosts P. canaliculata and A. fulica in Guangdong. The prevalence of A. cantonensis in wild snails and rats poses a substantial risk for angiostrongyliasis in humans.

[Advances in research on harm and control of Enterobius vermicularis infection in children].

In China, the infection rate of Enterobius vermicularis in children is still relatively high. Because the development and spread of worm eggs is fast, it is easy to treat but difficult to control the disease, and the control effect is also difficult to be consolidated. The long-term repeated Enterobius vermicularis infection may cause the damage on children's body and mind in different degrees. This paper offers an overview on the current status, harm and prevention and control of Enterobius vermicularis infection.

[Strategy of solidification and surveillance for schistosomiasis in transmission-interrupted provinces in China].

In schistosomiasis transmission-interrupted provinces in China, the endogenous source of infection has been basically cleared, and the exogenous source of infection is considered as a major threat. The residual snail area has been increasing in different degrees, and imported snails are regarded as a potential risk. So the possibility of schistosomiasis recrudescence still remains. According to the endemic characteristics, the integrated solidification strategy with emphasis on control of residual snails and imported cases should be taken in the future.

[Endemic situation of schistosomiasis in Guangdong Province from 2004 to 2009].

OBJECTIVE: To understand the endemic situation of schistosomiasis in Guangdong Province. METHODS: The surveillance of Oncomelania hupensis snails and infectious sources was carried out in the former endemic areas, and the surveillance data were statistically analyzed from 2004 to 2009 according to the national and provincial surveillance protocols. RESULTS: From 2004 to 2009, an area of 927.45 hm2 was surveyed and no living snails were found, and 287 out of 12 345 young people living in the endemic areas showed serum positive with the DIGFA, but none of schistosomiasis patients were found. A total of 28 766 mobile population were involved in the DIGFA examination, and 417 persons were positive, among them, 52 chronic patients were found, and 6 patients had eggs in their stools. Through the passive surveillance, 281 cases were reported from 2003 to 2009, and 4 acute cases were reported from 2004 (1 case) to 2005 (3 cases). A total of 9 064 head of cattle were surveyed and none of them was infected with Schistosoma japonicum by stool examination. CONCLUSIONS: The achievements of schistosomiasis control are solidified in Guangdong Province. However, the risk of schistosomiasis transmission still remains. The surveillance should be continued, especially of imported infectious sources and snails.

[Investigation on Angiostrongylus cantonensis infection in rodents in Guangdong Province].

OBJECTIVE: To investigate the natural infection of Angiostrongylus cantonensis in Guangdong Province, and to provide the scientific evidence for control measures. METHODS: The investigation was carried out in 56 villages of 28 towns of 28 counties/districts in East Guangdong, West Guangdong, the mountain area of North Guangdong and Peal River Delta of the Province from 2005 to 2010. The rodents were captured with live trap and the species identified. Angiostrongylus cantonensis adult worms were collected from the hearts and lungs of rodents, examined, counted and the sex of worms identified. RESULTS: The rodents were captured from 2005 to 2010, belonged to 2 orders, 2 families (subfamily), 4 genera and 10 species. Seven species of the rodents were found infected with Angiostrongylus cantonensis in all 28 counties/districts. Totally 5 820 rats were examined and 496 infected ones were identified, with a mean infection rate of 8.52%. The infection rate of rodents was highest in the Peal River Delta, reaching 9.8% (205/2084) (chi2=15.25, P<0.01). Rattus norvegicus had the highest infection rate of 16.9% (310/1 835) (chi2=240.91, P<0.01). The mean intensity of infection was 6.1 worms/rat. 1 125 female and 1064 male worms were found respectively (chi2=1.75, P>0.05). CONCLUSION: Natural infection of Angiostrongylus cantonensis in rodents has been found in all the 56 villages selected from the 4 regions of Guangdong Province.

[Survey on the focus of Angiostrongylus cantonensis in Guangdong Province].

OBJECTIVE: To understand the distribution of Angiostrongylus cantonensis foci in Guangdong Province for making surveillance program. METHODS: Survey sites were chosen by strata sampling according to different geographic locations. Totally 22 survey sites were selected in four regions: East Guangdong, West Guangdong, North Guangdong and the Pearl River Delta. One or two administrative villages in each site were randomly selected for the investigation. Pomacea canaliculata and Achatina fulica collected from fields and other species of freshwater or terrestrial snails obtained in the restaurants and wet markets were examined for the third stage larvae by tissue grinding or lung examination. Rats were captured in the fields, and their hearts and lungs were dissected for adult worms. Rat feces were also collected for the detection of first stage larvae by water precipitation. RESULTS: Large number of P. canaliculata was found in all sites. A. fulica was found in most surveyed sites. Totally 2929 P. canaliculata and 1354 A. fulica were collected with a larva infection rate of 5.9% (172/2929) and 16.5% (223/1354), respectively (P<0.01). The average prevalence among the regions was different (P<0.01) with the highest prevalence in Pearl River Delta (15.6%, 152/975), especially in Dongguan City of the Delta (34.7%, 78/225). 114 Cipangopaludina sp. and 252 Bellamya sp. were bought from wet markets of 9. sites. Larvae were found only in Bellamya snails from Luoding and Kaiping cities with an infection rate of 1.4% (1/70) and 3.3% (3/91), respectively. Totally 491 rats were captured in 9 sites including Rattus norvegicus, R. flavipectus, Suncus murinus, Mus musculus, Bandicota indica, R. losea and R. rattus, with an average infection rate of 11.4% (56/491). Adult worms were found in R. norvegicus, R. flavipectus and B. indica with a prevalence of 19.8% (52/263), 2.5% (3/118) and 10.0% (1/10), respectively. Thirty-four rodent fecal samples were collected in 7 sites and examined with a larva positive rate of 44.1% (15/34). CONCLUSION: Foci of Angiostrongylus cantonensis are widely distributed in Guangdong Province as natural infection has been found in its intermediate and definitive hosts.

[Follow-up survey on the imported cases of lymphatic filariasis in Guangdong Province].

OBJECTIVE: To make a survey on the possible imported cases with microfilaremia from a recently identified outbreak focus in Fuchuan County of Guangxi Region. METHODS: Moving people as temporary laborers from Guangxi and periphery residents were screened by thick blood smears for microfilariae and ELISA for specific IgG4 in Sept 2007. RESULTS: 989 persons in cities/districts of Nansha, Panyu, Shantou and Zhongshan were investigated. Among 150 persons from Changtang administrative village of Guangxi, 47 were from two outbreak focuses, Ganshang and Yinshan natural villages in Changtang. Three cases with microfilaremia were found, with a microfilaraemia density of 24, 20 and 2 per 120 microl blood, respectively. The 3 cases were all from the 2 natural villages, with a microfilaraemia positive rate of 6.4% (3/47). Meanwhile, anti-filaria IgG4 was detected for other 1 501 persons, including those from the outbreak focuses, from surr-founding areas and from non-endemic area as control, fifteen cases were found with IgG4 positive. Of the 15 positive cases, 12 were from the 2 outbreak natural villages, with a positive rate of 25.5%, higher than those of others (chi2=295.83, P < 0.01). The cases with IgG4 positive but microfilaremia negative were reexamined by ICT kit and all showed negative. CONCLUSION: It is suggested that no further transmission occurs although microfilaremia cases have been imported from the outbreak focus of Guangxi.