Degradation of polycyclic aromatic hydrocarbons in soil by a two-step sequential treatment

The objectives of this work were to isolate the microorganisms responsible for a previously observed degradation of polycyclic aromatic hydrocarbons (PAH) in soil and to test a method for cleaning a PAH-contaminated soil. An efficient PAH degrader was isolated from an agricultural soil and designated as Mycobacterium LP1. In liquid culture, it degraded phenanthrene (58%), pyrene (24%), anthracene (21%) and benzo(a)pyrene (10%) present in mixture (initial concentration 50 μg ml⁻¹ each) and phenanthrene (92%) and pyrene (94%) as sole carbon sources after 14 days of incubation at 30°C. In soil, Mycobacterium LP1 mineralised ¹⁴C-phenanthrene (45%) and ¹⁴C-pyrene (65%) after 10 days. The good ability of this Mycobacterium was combined with the benzo(a)pyrene oxidation effect obtained by 1% w/w rapeseed oil in a sequential treatment of a PAH-spiked soil (total PAH concentration 200 mg kg⁻¹). The first step was incubation with the bacterium for 12 days and the second step was the addition of the rapeseed oil after this time and a further incubation of 22 days. Phenanthrene (99%), pyrene (95%) and anthracene (99%) were mainly degraded in the first 12 days and a total of 85% of benzo(a)pyrene was transformed during the whole process. The feasibility of the method is discussed.     

Microbial production of optically active β-phenylalanine ethyl ester through stereoselective hydrolysis of racemic β-phenylalanine ethyl ester

The ability to produce (R)- or (S)-β-phenylalanine ethyl ester (3-amino-3-phenylpropionic acid ethyl ester, BPAE) from racemic BPAE through stereoselective hydrolysis was screened for in BPAE-assimilating microorganisms. Sphingobacterium sp. 238C5 and Arthrobacter sp. 219D2 were found to be potential catalysts for (R)- and (S)-BPAE production, respectively. On a 24-h reaction, with 2.5% (w/v) racemic BPAE (130 mM) as the substrate and wet cells of Sphingobacterium sp. 238C5 as the catalyst, 1.15% (w/v) (R)-BPAE (60 mM) with enantiomeric purity of 99% e.e. was obtained, the molar yield as to racemic BPAE being 46%. On a 48-h reaction, with 2.5% (w/v) racemic BPAE (130 mM) as the substrate and wet cells of Arthrobacter sp. 219D2 as the catalyst, 0.87% (w/v) (S)-BPAE (45 mM) with enantiomeric purity of 99% e.e. was obtained, the molar yield as to racemic BPAE being 35%. The enzyme stereoselectively hydrolyzing (S)-BPAE was purified to homogeneity from the cell-free extract of Sphingobacterium sp. 238C5. The enzyme was a monomeric protein with a molecular mass of about 42,000. The enzyme catalyzed hydrolysis of β-phenylalanine esters, while the common aliphatic and aromatic carboxylate esters were not catalyzed.     

Bupropion for Weight Loss: An Investigation of Efficacy and Tolerability in Overweight and Obese Women

Objective: On the basis of the clinical observations that bupropion facilitated weight loss, we investigated the efficacy and tolerability of this drug in overweight and obese adult women. Research Methods and Procedures: A total of 50 overweight and obese (body mass index: 28.0 to 52.6 kg/m²) women were included. The core component of the study was a randomized, double‐blind, placebo‐controlled comparison for 8 weeks. Bupropion or placebo was started at 100 mg/d with gradual dose increase to a maximum of 200 mg twice daily. All subjects were prescribed a 1600 kcal/d balanced diet and compliance was monitored with food diaries. Responders continued the same treatment in a double‐blind manner for an additional 16 weeks to a total of 24 weeks. There was additional single‐blind follow‐up treatment for a total of 2 years. Results: Subjects receiving bupropion achieved greater mean weight loss (last‐observation‐carried‐forward analysis) over the first 8 weeks of the study (p = 0.0001): 4.9% ± 3.4% (n = 25) for bupropion treatment compared with 1.3% ± 2.4% (n = 25) for placebo treatment. For those who completed the 8 weeks, the comparison was 6.2% ± 3.1% (n = 18) vs. 1.6% ± 2.9% (n = 13), respectively(p = 0.0002), with 12 of 18 of the bupropion subjects (67%) losing over 5% of baseline body weight compared with 2 of 13 in the placebo group (15%; p = 0.0094). In the continuation phase, 14 bupropion responders who completed 24 weeks achieved weight loss of 12.9% ± 5.6% with fat accounting for 73.5% ± 3.7% of the weight lost and no change in bone mineral density as assessed by DXA. Bupropion was generally well‐tolerated in this sample. Discussion: Bupropion was more effective than placebo in achieving weight loss at 8 weeks in overweight and obese adult women in this preliminary study. Initial responders to bupropion benefited further in the continuation phase.     

Oviposition and development of Drosophila modified by magnetic fields

Drosophila flies placed in a habitat with two lateral boxes demonstrated sensitivity to magnetic fields: Oviposition decreased by exposure to pulsated extremely low frequency (ELF) (100)Hz, 1.76 miliTesla (mT) and sinusosidal fields (50 Hz, 1 mT), while there was no initial effect of exposure to a static magnetic field (4.5 mT). Drosophila eggs treated for 48 h with the above described fields showed that (1) mortality of eggs was lower in controls than in eggs exposed to all tested magnetic fields; (2) mortality of larvae increased when a permanent magnet was used; (3) mortality of pupae was highest when a permanent magnet was used; and (4) general adult viability was highest in controls (67%) and diminished progressively when eggs were exposed to pulsated (55%), sinusoidal (45%), and static (35%) magnetic fields.     

Occurrence and distribution of Carangidae larvae (Teleostei,Perciformes) from the Southwest Atlantic Ocean,Brazil (12–23°S)

The objective of this study was to identify larvae species composition, distribution and abundance of carangids along the Brazilian coastal shelf area in order to provide background information on the reproductive community patterns. All carangid larvae used in this study are from the larval fish collection of the Zooplankton and Ichthyoplankton Integrated Laboratory of Federal University of Rio de Janeiro – Brazil (DZUFRJ). Carangid larvae were collected in 13 surveys (nine in the dry season and four during the rainy season) between 1998 and 2008, from Bahia (12°S) to Rio de Janeiro (23°S), comprising 158 sampling stations (45 coastal; 98 oceanic; 15 over seamounts). A bongo net with 330 and 500‐μm mesh size was towed at a speed of about two knots, obliquely (surface‐bottom‐surface) from a maximum depth of 200 m. Samples were collected both during the day and at night and combined in the analysis. A total of 1321 carangid larvae were identified representing 14 species: Decapterus punctatus (56.7%), Chloroscombrus chrysurus (16.8%), Caranx crysos (8.4%), Selar crumenophthalmus (6.3%), Trachurus lathami (6.3%), Caranx latus (2.4%), Carangoides bartholomaei (1.3%), Oligoplites spp. (0.6%), Pseudocaranx dentex (0.3%), Seriola dumerili (0.2%), Elagatis bipinnulata (0.2%), Selene setapinnis (0.2%), Trachinotus carolinus (0.2%) and Selene vomer (0.1%). There was no significant difference in carangid density (P = 0.17) or in species composition (P = 0.09) among the coastal, oceanic and seamount stations. Although there was a significant difference in larval densities between the dry and rainy periods (P = 0.000264), the community composition did not vary significantly (P = 0.47). Therefore, seasonality (rainy and dry periods) seems to be the main factor affecting carangid densities although the community composition is not influenced by sampling periods or by the gradient coast‐ocean.     

Feeding ecology of the vulnerable aoudad (Ammotragus lervia) in north-western Sahara

The feeding ecology of the aoudad (Ammotragus lervia) was investigated for the first time in north-western Sahara, Djebel Antar (Bechar province, Algeria), from autumn 2015 to summer 2016. Microhistological analyses of faeces revealed an annual diet composed of 23 identified taxa belonging to 16 plant families. The highest species diversity was recorded in spring and summer (23 species), despite a marked consumption of two species: Vachellia tortilis (17.7%) and Avena sterilis (14.0%); diet diversity was lower in autumn and winter (16 species), including mainly Teucrium polium (14.7%, 21.0%) and Gymnocarpos decander (19.7%, 10.0%). The main plant parts consumed during these seasons were stems (77.7%, 65.3%), while leaves and inflorescences were mostly consumed during spring and summer (54.7%, 52.3%). Forbs dominated the aoudad's diet, with 46.3% average relative abundance, including mainly T. polium, Limoniastrum feei, and Chrysanthemum macrocarpum. Woody plants including mainly V. tortilis and G. decander accounted for 33.3% (50.0% in autumn), and grasses including A. sterilis and H. murinum for 20.4% (32.0% in summer). Based on this diet, A. lervia can be classified as a “generalist mixed-feeder.”     

Geographical Distribution and Molecular Identification of Larval. Trombiculid Mites in Korea (2005∼2007)

A surveillance of trombiculid mites was conducted by collecting wild small mammals twice a year (spring and autumn seasons) at 24 localities in Korea from 2005 to 2007 to clarify the nationwide distribution of scrub typhus vectors. Among 783 trapped rodents, Apodemus agrarius accounted for 87.4% and the trapping rate at riverside was recorded the highest. A total of 67,325 mites representing 4 genera and 14 species were collected and their chigger index (C. I.) was 86.0. The predominant species were Leptotrombidium pallidum (52.6%), L. scutellare (27.1%), L. palpale (8.2%), L. orientale (5.6%), and Neotrombicula tamiyai (1.7%). However, the portion of L. scutellare in southern area including endemic provinces such as Jeollabuk‐Do (34.3%), Jeollanam‐Do (49.0%), and Gyeongsangnam‐Do (88%) were relatively higher than middle areas where L. pallidum was predominant in. Additionally, in autumn season, the density of L. scutellare was increased up to 42.0% while that of L. pallidum was decrease to 37.6%. Now we are performing a periodic surveillance again (2011～2013) and trying to develop a method to identify these trombiculid mites using molecular markers.     

ANALYSIS OF HELICOVERPA ARMIGERA SINGLE NUCLEOPOLYHEDROVIRUS IMMEDIATE EARLY 1 (IE‐1) GENE*

Abstract A 6.12 kb Xbal‐H fragment of the Helicoverpa armigem single nucleopolyhedrovirus (HaSNPV) gemone was cloned and the complete sequence of this fragment was sequenced by random sequencing method. Sequence comparison and analysis revealed an ORF13 which was homologous to ie‐1 of Auiographa California nucleopolyhedrovirus (AcMNPV). The homologous encoding gene is ie‐1. The total length of the encoding region of HaSNPV gene was 1986 bp and was predicted to encode 661 amino acid protein(IE‐1) with molecular weight of 76.5 kD. The alingment of putative HaSNPV IE‐1 amino acid sequence with those of other 9 reported baculoviruses IE‐Is showed that the HaSNPV IE‐1 was most closely related to Helicoverpa zea nucleopolyhedrovirus (HzNPV) IE‐1, with 97% amino acid identidy. But it showed a low degree of sequence similarity to those of AcMNPV, Bombyx mori nucleopolyhedrovirus (BmNPV), Choristoneura fumiferana nucleopolyhedrovirus (CfMNPV), Lymantria dispar nucleopolyhedrovirus (LdMNPV), Orgyia pseudotsugata nucleopolyhedrovirus (OpMNPV), Spodoptera exigua nucleopolyhedrovirus (SeMNPV), Plutella xylostella granulovirus(PxGV) and Xestia c‐nigrum granulovirus (XcGV), with 23%, 23%, 23%, 25%, 23%, 14%, 27% and 7% amino acid identity, respectively. A phylogenetic tree of ten baculoviruses IE‐1 was also given.     

Selective excretion of yolk-derived tocotrienols into the bile of the chick embryo

The aim of this study was to investigate the possibility of biodiscrimination between different forms of vitamin E during the development of the chick embryo. The vitamin E present in the initial yolk consisted of α-tocopherol (90%), (β+γ)-tocopherol (8%), α-tocotrienol (0.3%) and (β+γ)-tocotrienol (1.3%). In marked contrast, the vitamin E recovered from the bile of the day-16 embryo contained much higher proportions of α-tocotrienol (10%) and especially of (β+γ)-tocotrienol (42%). By the time of hatching, 56% of the vitamin E present in the bile was in the form of (β+γ)-tocotrienol. The residual yolk of the newly-hatched chick contained far greater proportions of α-tocotrienol (2.6%) and (β+γ)-tocotrienol (10%) than were present in the initial yolk. The results suggest that the liver of the embryo may selectively excrete tocotrienols as components of bile, whilst retaining the tocopherols within the hepatocytes. The increased proportions of tocotrienols in the residual yolk may result from the recycling of bile from the gall bladder to the yolk. The liver of the day-old chick contained α-tocopherol as the main form of vitamin E (90%) with only a small proportion (0.2%) of (β+γ)-tocotrienol. The α-tocopherol form was also the main vitamin E component in the brain (85%), heart (79%), lung (82%) and adipose tissue (91%) of the day-old chick. The present study suggests the occurrence of a high degree of biodiscrimination between tocopherols and tocotrienols during the development of the chick embryo.     

Chemical Composition of the Essential Oil and Diethyl Ether Extract of Trinia glauca (L.) Dumort. (Apiaceae) and the Chemotaxonomic Significance of 5‐O‐Methylvisamminol

Analyses by GC, GC/MS, and NMR spectroscopy (1D‐ and 2D‐experiments) of the essential oil and Et₂O extract of Trinia glauca (L .) Dumort . (Apiaceae) aerial parts allowed a successful identification of 220 constituents, in total. The major identified compounds of the essential oil were (Z)‐falcarinol (10.6%), bicyclogermacrene (8.0%), germacrene D (7.4%), δ‐cadinene (4.3%), and β‐caryophyllene (3.2%), whereas (Z)‐falcarinol (47.2%), nonacosane (7.4%), and 5‐O‐methylvisamminol (4.0%) were the dominant constituents of the extract of T. glauca. One significant difference between the compositions of the herein and the previously analyzed T. glauca essential oils (only two reports) was noted. (Z)‐Falcarinol was the major constituent in our case, whereas germacrene D (14.4 and 19.6%) was the major component of the previously studied oils. Possible explanations for this discrepancy were discussed. 5‐O‐Methylvisamminol, a (furo)chromone identified in the extract of T. glauca, has a limited occurrence in the plant kingdom and is a possible excellent chemotaxonomic marker (family and/or subfamily level) for Apiaceae.     

Pollen analysis of honeys of Melipona (Michmelia) seminigra merrillae and Melipona (Melikerria) interrupta (Hymenoptera: Apidae) bred in Central Amazon,Brazil

The pollen present in honey in colonies of Melipona seminigra merrillae and Melipona interrupta bred in Manaus was analysed. Between August and October 2012, honey samples were collected from the Sucupira meliponary, located in Manaus, Amazonas, Brazil. We identified a total of 70 pollen types belonging to 35 botanical families. In the samples from Melipona seminigra merrillae, the most represented pollen types were: Miconia-type (Melastomataceae) was the dominant pollen (DP) in August (51.19%), September (76.83%) and October (58.33%); Triplaris-type (Polygonaceae) was an accessory pollen (AP) in August (20.5%); and the remaining pollen types were classified as isolated pollen (IP), with Talisia macrophylla (Sapindaceae) exhibiting the highest percentage in August (12.92%). For Melipona interrupta, the most frequent pollen types were as follows: Miconia-type was the DP in August (59.33%) and October (61.33%) and an AP in September (37.5%); and Triplaris-type was an AP in August (35.83%), September (34.16%) and October (23.33%). The diversity of pollen types was not significantly different between the bees in the months evaluated. However, there was a large significant niche overlap in the months studied, August (O_ik = 0.95), October (O_ik = 0.89) and September (O_ik = 0.69), revealing that of the 70 pollen types found in the samples, 22 were shared by the two bee species in large proportions, 28 were exploited exclusively by Melipona seminigra merrillae and 20 were collected only by Melipona interrupta.     

Microbial diversity and composition in acidic sediments of freshwater finfish culture ponds fed with two types of feed: a metagenomic approach

Microbial community profile associated with acidic pond sediments (APS) (pH = 3·0–4·5) of freshwater finfish aquaculture ponds (n = 8) was investigated. Sediment DNA extracted from the eight APS were subjected to high-throughput sequencing of V3 and V4 regions which yielded 7236 operational taxonomic units (OTUs) at a similarity of 97%. Overall results showed higher proportion of bacterial OTUs than archaeal OTUs in all the APS. Euryarchaeota (23%), Proteobacteria (19%), Chloroflexi (17%), Crenarchaeota (5·3%), Bacteroidetes (4·8%), Nitrospirae (3·2%), Nanoarchaeaeota (3%) which together constituted 75% of the microbial diversity. At the genus level, there was high preponderance of methanogens namely Methanolinea (5·4%), Methanosaeta (4·5%) and methanotrops, Bathyarchaeota (5%) in APS. Moreover, the abundant phyla in the APS were not drastically affected by the administration of chicken slaughter waste (R-group ponds) and commercial fish feed (C-group ponds), since 67% of the OTUs generated remained common in the APS of both the groups of ponds. There was a minimal difference of 24–26% of OTUs between C-group and R-group ponds, suggesting the existence of a core microbial community in these ponds driven by acidic pH over the years. This study concludes that microbial diversity in pond sediment was influenced to a lesser extent by the addition of chicken slaughter waste but was majorly driven by acidic nature of the pond.     

Species diversity and population dynamics of rodents in a farm‐fallow field mosaic system in Central Tanzania

A Capture‐Mark‐Recapture study was undertaken in Central Tanzania to compare variations in community structure and population dynamics of rodents in two types of habitats. The study was conducted in fallow field mosaic habitat dominated by perennial and annual grasses (grid BEA) and a more heterogeneous habitat (grid BEB) which was previously woodland cleared of most trees with vegetation dominated by shrubs, bushes, scattered trees and perennial grass. The relative abundance of rodents in BEA was: Mastomys natalensis (73.5%) > Aethomys chrysophilus (8.9%) > Gerbilliscus vicina (7.3%) > Arvicanthis neumanni (6.1%) > Acomys spinosissimus (4.1%) and for grid BEB: M. natalensis (67.6%) > G. vicina (11.2%) > A. neumanni (10.3%) > A. chrysophilus (7.6%) > A. spinosissimus (2.9%). Graphiurus sp., Mus minutoides, Saccostomus mearnsi, Lemniscomys striatus and L. griselda were rare and only occasionally trapped in BEB. Spatial variations in population density were non‐significant except for A. chrysophilus. Significant temporal variations within grids were observed, with synchrony of population peaks for some species. The rare species boosted species richness of grid BEB rather artificially, without significantly contributing to higher species diversity. Temporal variations in Simpson’s Diversity indices between grids were non‐significant except for three out of twenty‐one trapping sessions.     

Poly(3-hydroxyalkanoate) polymerase synthesis and in vitro activity in recombinant Escherichia coli and Pseudomonas putida

We tested the synthesis and in vitro activity of the poly(3-hydroxyalkanoate) (PHA) polymerase 1 from Pseudomonas putida GPo1 in both P. putida GPp104 and Escherichia coli JMU193. The polymerase encoding gene phaC1 was expressed using the inducible PalkB promoter. It was found that the production of polymerase could be modulated over a wide range of protein levels by varying inducer concentrations. The optimal inducer dicyclopropylketone concentrations for PHA production were at 0.03% (v/v) for P. putida and 0.005% (v/v) for E. coli. Under these concentrations the maximal polymerase level synthesized in the E. coli host (6% of total protein) was about three- to fourfold less than that in P. putida (20%), whereas the maximal level of PHA synthesized in the E. coli host (8% of total cell dry weight) was about fourfold less than that in P. putida (30%). In P. putida, the highest specific activity of polymerase was found in the mid-exponential growth phase with a maximum of 40 U/g polymerase, whereas in E. coli, the maximal specific polymerase activity was found in the early stationary growth phase (2 U/g polymerase). Our results suggest that optimal functioning of the PHA polymerase requires factors or a molecular environment that is available in P. putida but not in E. coli.     

Distribution of overwintering mosquitoes (Diptera: Culicidae) in grassy fields in the Republic of Korea, 2007–2008

Overwintering mosquitoes in a grassy field were surveyed at 13 different localities from December 2007 to February 2008 in the Republic of Korea (ROK). Mosquitoes were collected by putting a white colored tent on the grass, without the base, and heating the inside of the tent. A total of 784 female adults comprising seven species were collected during the study period, including 395 (45.6%) Anopheles pullus, 338 (43.2%) An. sinensis, 21 (2.7%) An. belenrae, 2 (0.3%) An. kleini, 43 (5.5%) Culex tritaeniorhynchus, 20 (2.5%) Cx. inatomii, and 1 (0.3%) Cx. pipiens complex. The mosquitoes showed different overwintering distributions by temperature zone and locality. Predominant species, the malaria vectors An. pullus and An. sinensis, showed different overwintering distributions. Anopheles pullus had a 90.9% collection rate except for Youngju and an average – 0.6°C temperature between December and February. Anopheles pullus showed >50% collection rate in most regions maintained below an average of ?1.4°C, and the rate of An. sinensis showed more than 50% collection rate in all regions maintained at an average above ?1.1°C. Other species showed regional characteristics; An. belenrae was distributed in the northwest part of the ROK, and An. kleini was collected rarely at one locality in the middle part of ROK. Culex tritaeniorhynchus, a Japanese encephalitis virus vector, was distributed in the southern and costal region and maintained at an above average of ?1.0°C. Culex inatomii was collected on the coastal region of the ROK.     

Biotransformations of Bile Acids with Bacteria from Cayambe Slaughterhouse (Ecuador): Synthesis of Bendigoles

The biotransformations of cholic acid ( 1a ), deoxycholic acid ( 1b ), and hyodeoxycholic acid ( 1c ) to bendigoles and other metabolites with bacteria isolated from the rural slaughterhouse of Cayambe (Pichincha Province, Ecuador) were reported. The more active strains were characterized, and belong to the genera Pseudomonas and Rhodococcus. Various biotransformation products were obtained depending on bacteria and substrates. Cholic acid ( 1a ) afforded the 3‐oxo and 3‐oxo‐4‐ene derivatives 2a and 3a (45% and 45%, resp.) with P. mendocina ECS10, 3,12‐dioxo‐4‐ene derivative 4a (60%) with Rh. erythropolis ECS25, and 9,10‐secosteroid 6 (15%) with Rh. erythropolis ECS12. Bendigole F ( 5a ) was obtained in 20% with P. fragi ECS22. Deoxycholic acid ( 1b ) gave 3‐oxo derivative 2b with P. prosekii ECS1 and Rh. erythropolis ECS25 (20% and 61%, resp.), while 3‐oxo‐4‐ene derivative 3b was obtained with P. prosekii ECS1 and P. mendocina ECS10 (22% and 95%, resp.). Moreover, P. fragi ECS9 afforded bendigole A ( 8b ; 80%). Finally, P. mendocina ECS10 biotransformed hyodeoxycholic acid ( 1c ) to 3‐oxo derivative 2c (50%) and Rh. erythropolis ECS12 to 6α‐hydroxy‐3‐oxo‐23,24‐dinor‐5β‐cholan‐22‐oic acid ( 9c , 66%). Bendigole G ( 5c ; 13%) with P. prosekii ECS1 and bendigole H ( 8c ) with P. prosekii ECS1 and Rh. erythropolis ECS12 (20% and 16%, resp.) were obtained.     

青檀叶片内生和附生真菌组成及生态分布

对我国古老特有植物青檀叶片进行内生和附生真菌的研究,以了解青檀叶片内生和附生真菌的组成特点和探讨内生和附生真菌菌群之间的可能联系,为研究真菌资源多样性、植物附生和内生真菌的相互演化关系及真菌与宿主植物协同进化等提供有益参考资料。研究结果表明,从健康的青檀叶片获得可培养内生真菌839株,附生真菌1857株,共计2696株,鉴定其分属于4目,5科,43属。在目的分类水平上,内生和附生真菌均以丛梗孢目Moniliales为优势菌群,分别占90.23%和92.51%;在科的水平上,内生真菌以暗梗孢科Dematiaceae和丛梗孢科Moniliaceae为优势菌群,分别占47.56%和42.67%,附生真菌以丛梗孢科Moniliaceae和暗梗孢科Dematiaceae为优势菌群,分别占67.04%和25.47%;在属的水平上,内生真菌以黑团孢属Periconia和青霉属Penicillium为优势菌群,分别占31.47%和10.73%,附生真菌以小球霉属Glomerularia、膝葡孢属Gonatobotrys和青霉属Penicillium为优势菌群,分别占20.03%、13.95%和12.22%。青檀叶片内生真菌和附生真菌均存在的菌群数量达到23个属,占53.49%。内生真菌特有的属有6个,共分离19株,占0.70%,附生真菌特有的属有14个,共分离120株,占4.45%。内生真菌的Shannon-Wiener index(H')多样性指数(2.44)和Margalef index(R)丰富度指数(2.88)分别小于附生真菌ShannonWiener index(H')多样性指数(2.57)和Margalef index(R)丰富度指数(3.32),但两者的Evenness index(E)均匀度指数几乎相等。青檀叶片内生和附生真菌菌群组成具有较高的相似性,相似性系数达0.70。通过Fisher's exact test分析表明青檀叶片内生和附生真菌菌群组成无明显差异(P=0.072)。     

Prevalence of trypanosomes,salivary gland hypertrophy virus and Wolbachia in wild populations of tsetse flies from West Africa

Background

Tsetse flies are vectors of African trypanosomes, protozoan parasites that cause sleeping sickness (or human African trypanosomosis) in humans and nagana (or animal African trypanosomosis) in livestock. In addition to trypanosomes, four symbiotic bacteria Wigglesworthia glossinidia, Sodalis glossinidius, Wolbachia, Spiroplasma and one pathogen, the salivary gland hypertrophy virus (SGHV), have been reported in different tsetse species. We evaluated the prevalence and coinfection dynamics between Wolbachia, trypanosomes, and SGHV in four tsetse species (Glossina palpalis gambiensis, G. tachinoides, G. morsitans submorsitans, and G. medicorum) that were collected between 2008 and 2015 from 46 geographical locations in West Africa, i.e. Burkina Faso, Mali, Ghana, Guinea, and Senegal.

Results

The results indicated an overall low prevalence of SGHV and Wolbachia and a high prevalence of trypanosomes in the sampled wild tsetse populations. The prevalence of all three infections varied among tsetse species and sample origin. The highest trypanosome prevalence was found in Glossina tachinoides (61.1%) from Ghana and in Glossina palpalis gambiensis (43.7%) from Senegal. The trypanosome prevalence in the four species from Burkina Faso was lower, i.e. 39.6% in Glossina medicorum, 18.08%; in Glossina morsitans submorsitans, 16.8%; in Glossina tachinoides and 10.5% in Glossina palpalis gambiensis. The trypanosome prevalence in Glossina palpalis gambiensis was lowest in Mali (6.9%) and Guinea (2.2%). The prevalence of SGHV and Wolbachia was very low irrespective of location or tsetse species with an average of 1.7% for SGHV and 1.0% for Wolbachia. In some cases, mixed infections with different trypanosome species were detected. The highest prevalence of coinfection was Trypanosoma vivax and other Trypanosoma species (9.5%) followed by coinfection of T. congolense with other trypanosomes (7.5%). The prevalence of coinfection of T. vivax and T. congolense was (1.0%) and no mixed infection of trypanosomes, SGHV and Wolbachia was detected.

Conclusion

The results indicated a high rate of trypanosome infection in tsetse wild populations in West African countries but lower infection rate of both Wolbachia and SGHV. Double or triple mixed trypanosome infections were found. In addition, mixed trypanosome and SGHV infections existed however no mixed infections of trypanosome and/or SGHV with Wolbachia were found.

     

Prevalence and distribution of Borrelia and Babesia species in ticks feeding on dogs in the U.K.

Ticks were collected during March–July 2015 from dogs by veterinarians throughout the U.K. and used to estimate current prevalences and distributions of pathogens. DNA was extracted from 4750 ticks and subjected to polymerase chain reaction and sequence analysis to identify Borrelia burgdorferi sensu lato (Spirochaetales: Spirochaetaceae) and Babesia (Piroplasmida: Babesiidae) species. Of 4737 ticks [predominantly Ixodes ricinus Linneaus (Ixodida: Ixodidae)], B. burgdorferi s.l. was detected in 94 (2.0%). Four Borrelia genospecies were identified: Borrelia garinii (41.5%); Borrelia afzelli (31.9%); Borrelia burgdorferi sensu stricto (25.5%), and Borrelia spielmanii (1.1%). One Rhipicephalus sanguineus Latreille (Ixodida: Ixodidae), collected from a dog with a history of travel outside the U.K., was positive for B. garinii. Seventy ticks (1.5%) were positive for Babesia spp. Of these, 84.3% were positive for Babesia venatorum, 10.0% for Babesia vulpes sp. nov., 2.9% for Babesia divergens/Babesia capreoli and 1.4% for Babesia microti. One isolate of Babesia canis was detected in a Dermacentor reticulatus (Ixodida: Ixodidae) tick collected from a dog that had recently travelled to France. Prevalences of B. burgdorferi s.l. and Babesia spp. did not differ significantly between different regions of the U.K. The results map the widespread distribution of B. burgdorferi s.l. and Babesia spp. in ticks in the U.K. and highlight the potential for the introduction and establishment of exotic ticks and tick‐borne pathogens.