Yuzaoea gen. nov., a new biraphid diatom(Bacillariophyceae)genus and its phylogenetic significance

The flexed frustules in pennate diatoms are usually associated with monoraphid diatoms. Interestingly, we found a biraphid diatom species with flexed frustules in an offshore intertidal beach environment on Weizhou Island,Beihai City, Guangxi Zhuang Autonomous Region, China. Therefore, based on morphological characteristics, we described a new genus of diatoms Yuzaoea sinensis gen. et sp. nov. CH Li, HH Liu, YH Gao & CP Chen. The frustule of this genus is characterized by heterogeneous frustule with one concave valve and one convex valve,complete raphe on both valves, straight and moderately eccentric raphe, uniseriate striae and girdle bands with a single row of areolae. The most identifying feature of this genus was the flexed frustule, which is rare in biraphid diatoms and common in monoraphid diatoms. We compared the morphometric characteristics of genus Yuzaoea with genus Rhoikoneis and several genera within the family Rhoicospheniaceae, including Rhoicosphenia,Campylopyxis, and Cuneolus. Phylogenetic analyses based on SSU rRNA and rbc L showed that the genus Yuzaoea was the sister group to the clade of Rhoicosphenia with a high support value(bootstrap values = 100%), and the clade “Yuzaoea+Rhoicosphenia” was sister to the clade of monoraphid diatoms, in which the genera Achnanthidium, Planothidium and some Cocconeis with high support values(bootstrap = 100%).Morphologically, the genus Yuzaoea shares many morphological features with monoraphid diatoms like genera Achnanthidium and Planothidium and the members within the Rhoicospheniaceae. Therefore, based on a combined morphological studies and phylogenetic results we suggested that this branch may represented the evolution of one kind monoraphid diatoms, from biraphid diatoms(e.g. genus Yuzaoea), to incompleted biraphid diatoms(e.g. genera Rhoicosphenia, Campylopyxis), to monoraphid diatoms(e.g. genera Achnanthidium and Planothidium).

Responses of phytoplankton and its satellite bacteria to exogenous ethanol

The response of phytoplankton and its satellite bacteria to various concentrations(0.01%-10%v/v)of ethanol is studied.To elucidate the effect of ethanol,single-strains of phytoplankton(SSP)culture,pure strains of satellite bacteria isolated from nonaxenic SSP cultures,and Escherichia coli were screened.Results indicate that ethanol could promote the growth and photo synthetic efficiency(F_(v)/F_(m))of S SP at 0.01%and the growth of satellite bacteria at 0.01%-1%.Nevertheless,ethanol inhibited the growth and F_(v)/F_(m)of SSP at 0.1%-1%,and killed bacteria and SSP at 10% concentration.Further investigation on a satellite bacterium(Mameliella alba)revealed that ethanol promotes growth by serving as a growth stimulant rather than a metabolic carbon source.The 16 S rRNA gene amplicon indicated that all nonaxenic S SP cultures harbor distinct satellite bacteria communities where the SSP culture of Skeletonema costatum,Phaeodactylum tricornutum,and Dunaliella bardawil were dominated by bacteria genera of Marivita(~80%),Dinoroseobacter(~47%),and Halomonas(~87%),respectively,indicating that every SSP cultures have their own distinct satellite bacterial community.The bacteria family Rhodobacteraceae was dominant in the two marine diatoms,whereas Halomonadaceae was dominant in the saline green microalga.Compared to their respective controls,the supply of 0.5% ethanol to SSP cultures promoted the growth of the satellite bacteria but did not cause a significant difference in species composition of satellite bacteria.Therefore,a low concentration of ethanol can promote the growth of bacteria in a non-selective way.This study enriched our knowledge about the effect of ethanol on aquatic microbes and provided a baseline for basic and applied biotechnological re search in the aquatic environment in the future.

Distribution of phytoplankton in the East China Sea and the southern Yellow Sea in spring in relation to environmental variables and dimethylsulfide compounds

The coastal ecosystems are highly sensitive to climate change and are usually influenced by variations in phytoplankton communities and water physiochemical factors.In the present study,the phytoplankton community,chlorophyll a(Chl a)and their relationships with environmental variables and dimethylsulfide(DMS)and dimethylsulfoniopropionate(DMSP)were investigated in spring 2017(March 24 to April 16)in the East China Sea(26.0°-33.0°N,120.0°-128.0°E)and southern Yellow Sea(31.0°-36.0°N,120.0°-125.0°E).The spatial distributions of phytoplankton species composition and cell density were investigated by qualitative and quantitative methods and were compared with historical data to study phytoplankton species succession in the survey area.The results showed that there were 275 phytoplankton species belonging to 90 genera and 6 phyla in the survey area,of which 208 species belonged to 62 genera of Bacillariophyta and 56 species belonged to 20 genera of Pyrrophyta.The dominant phytoplankton species were Skeletonema dohrnii,Chaetoceros vanheurckii and Prorocentrum donghaiense.The phytoplankton cell densities ranged from 0.06×10^(4)cells/L to 418.73×10^(4)cells/L,with an average value of 21.46×10^(4)cells/L.In spring,the average ratio of Bacillariophyta/Pyrrophyta was41.13 for the entire study area.The areas with high phytoplankton cell density were mainly distributed in the northern South Yellow Sea and offshore waters of the East China Sea.According to a canonical correspondence analysis among phytoplankton and environmental parameters,the water Chl a concentrations were notably consistent with phytoplankton cell density(P<0.001),and both showed significant negative correlations with salinity and nitrite(P<0.05)and significant positive correlations with dissolved oxygen and pH(P<0.001).There was a significant positive correlation between diatom(both in cell density and in dominant species)and DMS(P<0.05),which indicated that diatoms play a greater role in DMS production in this investigated area.

Protoraphis Simonsen, a newly recorded marine epizoic diatom genus for China

Epizoic diatoms on marine copepods are common in nature and may have a special ecological relationship with their hosts.However,this special ecological group is not well known,and it has only rarely been studied in the China seas.To address this knowledge gap,the species diversity and classification of epizoic diatoms on planktonic copepods were studied with samples collected from the East China Sea.In the present study,a marine araphid diatom genus Protoraphis and its type species,Pr.hustedtiana,were observed and identified by light and electron microscopy,thus representing the first record of this genus and its type species in China.This genus is characterized by a median sternum strongly bent to opposite sides and terminate in two transapical grooves at the valve ends.Protoraphis hustedtiana was found to be epizoic on the posterior body appendages and segments of the marine calanoid copepod Candacia bradyi.An internal view shows a complex,ear-shaped process that is close to the apical slit field.The ecological habitats and geographical distributions of Protoraphis were also discussed,and,together with complementary morphological studies,our results have increased the number of records for marine epizoic diatoms to three genera with three species in China,including Pseudohimantidium and Pseudofalcula.

Relationship between toxic and harmful microalgae and environmental factors in typical mariculture areas of East China Sea

Toxic and harmful algal blooms are usually more frequent in mariculture areas due to the abundant trophic conditions.To investigate the relationship between toxic and harmful microalgae and environmental factors,we set up 12 stations near three mariculture regions(Gouqi Island,Sandu Bay,and Dongshan Bay)in the East China Sea.We collected samples from all four seasons starting from May 2020 to March 2021.We identifi ed 199 species belonging to 70 genera,of which 38 species were toxic and harmful,including 24 species of Dinophyceae,13 species of Bacillariophyceae,and 1 species of Raphidophyceae.The species composition of toxic and harmful microalgae showed a predominance of diatoms in the summer(August),and dinofl agellates in the spring(May),autumn(November),and winter(March).The cell densities of toxic and harmful microalgae were higher in summer(with an average value of 15.34×10^(3) cells/L)than in other seasons,3.53×10^(3) cells/L in spring,1.82×10^(3) cells/L in winter,and 1.0×10^(3) cells/L in autumn.Pseudo-nitzschia pungens,Prorocentrum minimum,Paralia sulcata,and Prorocentrum micans were the dominant species and were available at all 12 stations in the three mariculture areas.We selected 10 toxic and harmful microalgal species with frequency>6 at the survey stations for the redundancy analysis(RDA),and the results show that NO^(-)_(3),water temperature(WT),pH,DO,and NO^(-)_(2) were the main factors on distribution of toxic and harmful microalgae.We concluded that the rich nutrient conditions in the East China Sea mariculture areas increased the potential for the risk of toxic and harmful microalgal bloom outbreaks.

Chinia gen.nov.—the second diatom genus simonsenioid raphe from mangroves in Fujian,China

A new monotypic diatom genus Chinia gen.nov.from estuarine mangrove habitats in Fujian,China is described.Light,scanning and transmission electron microscopy observations of its morphology show that this diatom differs from any established raphid diatom genus.The new genus is distinguished by a strongly undulate valve face,eccentric raphe canal,and perforated copulae.Its distinctly elevated and perforated raphe canal,classifi ed as simonsenioid type,is supported by sparse infundibulum-like portulae,and the portulae are separated by large fenestrae.The valves of Chinia also have hymenate areolar occlusions and the raphe lacks a central nodule.However,unlike most Bacillariaceae with two plastids,including Simonsenia,Chinia has a single plastid similar to those in Entomoneis and Surirella.Despite the similarities to Simonsenia,Chinia features porous raphe canal and loose striation,which is different from those of Simonsenia that has a solid raphe canal and distinct rows of areolae.These distinctive cytological and morphological characters suggest an affinity of the new genus to the Bacillariaceae.

Erratum to:Chinia gen.nov.—the second diatom genus simonsenioid raphe from mangroves in Fujian,China

Erratum to:https://doi.org/10.1007/s00343-021-1067-0 The title of this article contains a few mistakes.The correct one is given below:Chinia gen.nov.—a second diatom genus with the simonsenioid raphe type from mangroves in Fujian Province,China*The online version of the original articles can be found at:https://doi.org/10.1007/s00343-021-1067-0.

Identification of Novel Bartonella washoensis Sequence Type 22 in Marmota himalayana-Jiuquan City,Gansu Province,China,2021–2022

Summary What is already known about this topic?The prevalence of rodent-adapted Bartonella species has been increasing significantly.However,the specific Bartonella species carried by Marmota himalayana(M.himalayana),a large rodent species,and the potential risk it poses to human populations remain unknown.What is added by this report?Bartonella washoensis(B.washoensis),associated with human endocarditis,was initially identified in M.himalayana,exhibiting a detection rate of approximately one-third and demonstrating a predilection for the heart and lungs.The discovery of the novel Sequence Type 22 has expanded both the isolation source and genetic lineage of B.washoensis.What are the implications for public health practice?Individuals residing within the M.himalayana plague focus are at an elevated risk for B.washoensis infection.Consequently,there is a pressing need for public health warnings and efficient clinical case identification in this population.

Epidemiological Characteristics of Plague in the Meriones unguiculatus Plague Focus--Inner Mongolia Autonomous Region,China,1950−2019

From 1950 to 2019,a total of 267 plague cases in humans were reported in the Inner Mongolia Autonomous Region with 133 deaths and 10,710 Yersinia pestis isolates;21 of these cases were reported from the Meriones unguiculatus(M.unguiculatus)plague focus with 6 deaths and 6,771 isolates.According to the plague situation in the Inner Mongolia Autonomous Region and the implementation of local preventive measures,the prevalence of plague in humans in the M.unguiculatus plague focus of the Inner Mongolia Autonomous Region could be divided into four stages.The first stage was the initial stage of plague prevention and control(1950–1959),with 0.80 cases annually and a case fatality rate of 37.50%.The second stage was the plague eradication stage(1960–1979),with 0.15 cases annually and a case fatality rate of 33.33%.The third stage was the plague surveillance stage(1980-1999),with 0.25 cases annually and a case fatality rate of 20.00%.The fourth stage is the comprehensive prevention and control stage under the emergency system(2000-2019),with 0.25 cases annually and a case fatality rate of 20.00%.The surveillance of rodent density(1981-2019)and studies on plague-related factors among M.unguiculatus have shown that the higher the M.unguiculatus density,the higher the nocturnal rodent capture rate(r=0.670,p<0.05)and the higher the indirect hemagglutination assay(IHA)positive rate of M.unguiculatus(r=0.344,p<0.05);the higher the percentage of hosts infected,the lower the M.unguiculatus density(r=-0.361,p<0.05)and the lower the IHA positive rate of M.unguiculatus(r=-0.337,p<0.05);the higher the percentage of nests infected with fleas,the lower the IHA positive rate of M.unguiculatus(r=-0.348,p<0.05).Together,these results suggest that it is necessary to simultaneously monitor the pathogens,serology,and vector index of M.unguiculatus to accurately reflect the plague prevalence among local animals.Although bubonic plague is the main plague type of the M.unguiculatus plague focus,severe pneumonic plague or septic plague may be secondary when the bubonic plague is misdiagnosed or not treated in time.In addition,the plague in animals is relatively virulent in the M.unguiculatus plague focus,and the risk of spreading to humans is higher.For plague in the Inner Mongolia Autonomous Region,comprehensive control efforts should be aimed at the M.unguiculatus focus,covering host animals,vector insects,and humans.

Wildlife-borne microorganisms and strategies to prevent and control emerging infectious diseases

China is one of the countries with the richest wildlife population.The large variety of widely distributed species act as natural or susceptible hosts for numerous infectious diseases.It is estimated that there are more than 1.2 million unknown virus species in China,and there might be 10,000–30,000 unknown bacteria in wild mammals on the Qinghai-Tibet Plateau alone.There are no less than 600,000 species of animal-borne parasites and approximately 2 million species of fungi worldwide.With rapid economic growth and globalization,humans and wildlife interact more frequently,which enhances the probability of wildlife-borne pathogens infecting humans.The occurrence of animal-borne infectious diseases will become the“new normal”we have to face in the future.Therefore,research should be carried out on wildlife-borne microorganisms and the prevention and control of emerging infectious diseases to establish an analytical framework and an evaluation technology system for risk assessment and early warning of potential animal-borne emerging infectious diseases.This will not only improve our understanding of wildlife-borne microbial communities but also enable in-depth analysis,discovery,early warning,and even prediction of major animal-borne emerging infectious diseases that might occur in the future.Furthermore,this research will reduce response times,minimize the social and economic impact and losses,enable interventions related to the emergence or spread of the disease as early as possible,and comprehensively improve our management of infectious disease outbreaks.