scholarly journals Bacterial Communities of Bartonella-Positive Fleas: Diversity and Community Assembly Patterns

2008 ◽  
Vol 74 (5) ◽  
pp. 1667-1670 ◽  
Author(s):  
Ryan T. Jones ◽  
Katherine F. McCormick ◽  
Andrew P. Martin

ABSTRACT We investigated the bacterial communities of nine Bartonella-positive fleas (n = 6 Oropsylla hirsuta fleas and n = 3 Oropsylla montana fleas), using universal primers, clone libraries, and DNA sequencing. DNA sequences were used to classify bacteria detected in a phylogenetic context, to explore community assembly patterns within individual fleas, and to survey diversity patterns in dominant lineages.

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Young Kyung Kim ◽  
Keunje Yoo ◽  
Min Sung Kim ◽  
Il Han ◽  
Minjoo Lee ◽  
...  

Abstract Bacterial communities in wastewater treatment plants (WWTPs) affect plant functionality through their role in the removal of pollutants from wastewater. Bacterial communities vary extensively based on plant operating conditions and influent characteristics. The capacity of WWTPs can also affect the bacterial community via variations in the organic or nutrient composition of the influent. Despite the importance considering capacity, the characteristics that control bacterial community assembly are largely unknown. In this study, we discovered that bacterial communities in WWTPs in Korea and Vietnam, which differ remarkably in capacity, exhibit unique structures and interactions that are governed mainly by the capacity of WWTPs. Bacterial communities were analysed using 16S rRNA gene sequencing and exhibited clear differences between the two regions, with these differences being most pronounced in activated sludge. We found that capacity contributed the most to bacterial interactions and community structure, whereas other factors had less impact. Co-occurrence network analysis showed that microorganisms from high-capacity WWTPs are more interrelated than those from low-capacity WWTPs, which corresponds to the tighter clustering of bacterial communities in Korea. These results will contribute to the understanding of bacterial community assembly in activated sludge processing.


2016 ◽  
Vol 82 (11) ◽  
pp. 3225-3238 ◽  
Author(s):  
Laura Glendinning ◽  
Steven Wright ◽  
Jolinda Pollock ◽  
Peter Tennant ◽  
David Collie ◽  
...  

ABSTRACTSequencing technologies have recently facilitated the characterization of bacterial communities present in lungs during health and disease. However, there is currently a dearth of information concerning the variability of such data in health both between and within subjects. This study seeks to examine such variability using healthy adult sheep as our model system. Protected specimen brush samples were collected from three spatially disparate segmental bronchi of six adult sheep (age, 20 months) on three occasions (day 0, 1 month, and 3 months). To further explore the spatial variability of the microbiotas, more-extensive brushing samples (n= 16) and a throat swab were taken from a separate sheep. The V2 and V3 hypervariable regions of the bacterial 16S rRNA genes were amplified and sequenced via Illumina MiSeq. DNA sequences were analyzed using the mothur software package. Quantitative PCR was performed to quantify total bacterial DNA. Some sheep lungs contained dramatically different bacterial communities at different sampling sites, whereas in others, airway microbiotas appeared similar across the lung. In our spatial variability study, we observed clustering related to the depth within the lung from which samples were taken. Lung depth refers to increasing distance from the glottis, progressing in a caudal direction. We conclude that both host influence and local factors have impacts on the composition of the sheep lung microbiota.IMPORTANCEUntil recently, it was assumed that the lungs were a sterile environment which was colonized by microbes only during disease. However, recent studies using sequencing technologies have found that there is a small population of bacteria which exists in the lung during health, referred to as the “lung microbiota.” In this study, we characterize the variability of the lung microbiotas of healthy sheep. Sheep not only are economically important animals but also are often used as large animal models of human respiratory disease. We conclude that, while host influence does play a role in dictating the types of microbes which colonize the airways, it is clear that local factors also play an important role in this regard. Understanding the nature and influence of these factors will be key to understanding the variability in, and functional relevance of, the lung microbiota.


2021 ◽  
Author(s):  
Lixin Tian ◽  
Feifei Zhang ◽  
Pengliang Chen ◽  
Panpan Zhang ◽  
Zhijun Gao ◽  
...  

Abstract It is of great ecological significance to understand how the assembly processes of soil microbe communities respond to environmental change. However, the assembly processes of the rhizosphere bacterial communities in three minor grain crops (i.e., foxtail millet, proso millet, and sorghum) across agro-ecosystems are rarely investigated. Here, we investigated the environmental thresholds and phylogenetic signals for ecological preferences of rhizosphere bacterial communities of three minor grain crop taxa across complex environmental gradients to reflect their environmental adaptation. Additionally, we reported environmental factors affecting their community assembly processes based on a large-scale soil survey in agricultural fields across northern China using high-throughput sequencing.. The results demonstrated a narrower range of environmental thresholds and weaker phylogenetic signals for the ecological traits of rhizosphere bacteria in proso millet than in foxtail millet and sorghum fields, while proso millet rhizosphere community was the most phylogenetically clustered. The null model analysis indicated that homogeneous selection belonging to deterministic processes governed the sorghum rhizosphere community, whereas dispersal limitation belonging to stochastic processes was the critical assembly process in the foxtail and proso millet. Mean annual temperature was the decisive factor for adjusting the balance between stochasticity and determinism of the foxtail millet, proso millet, and sorghum rhizosphere communities. A higher temperature resulted in stochasticity in the proso millet and sorghum communities. For the foxtail millet community, the deterministic assembly increased with an increase in temperature. These results contribute to the understanding of root-associated bacterial community assembly processes in agro-ecosystems on a large scale.


2020 ◽  
Author(s):  
Kevin R. Theis ◽  
Roberto Romero ◽  
Andrew D. Winters ◽  
Alan H. Jobe ◽  
Nardhy Gomez-Lopez

ABSTRACTThe prevailing paradigm in obstetrics has been the sterile womb hypothesis. However, some are asserting that the placenta, intra-amniotic environment, and fetus harbor microbial communities. The objective of this study was to determine if the fetal and placental tissues of rhesus macaques harbor viable bacterial communities. Fetal, placental, and uterine wall samples were obtained from cesarean deliveries without labor (∼130/166 days gestation). The presence of viable bacteria in the fetal intestine and placenta was investigated through culture. The bacterial burden and profile of the placenta, umbilical cord, and fetal brain, heart, liver, and colon were determined through quantitative real-time PCR and DNA sequencing. These data were compared with those of the uterine wall, as well as to negative and positive technical controls. Bacterial cultures of fetal and placental tissues yielded only a single colony of Cutibacterium acnes. This bacterium was detected at a low relative abundance (0.02%) in the 16S rRNA gene profile of the villous tree sample from which it was cultured, yet it was also identified in 12/29 background technical controls. The bacterial burden and profile of fetal and placental tissues did not exceed or differ from those of background technical controls. In contrast, the bacterial burden and profiles of positive controls exceeded and differed from those of background controls. Among the macaque samples, distinct microbial signals were limited to the uterine wall. Therefore, using multiple modes of microbiologic inquiry, there was not consistent evidence of viable bacterial communities in the fetal and placental tissues of rhesus macaques.IMPORTANCEMicrobial invasion of the amniotic cavity (i.e. intra-amniotic infection) has been causally linked to pregnancy complications, especially preterm birth. Therefore, if the placenta and the fetus are typically populated by low biomass yet viable microbial communities, current understanding of the role of microbes in reproduction and pregnancy outcomes will need to be fundamentally reconsidered. Could these communities be of benefit by competitively excluding potential pathogens or priming the fetal immune system for the microbial bombardment it will experience upon delivery? If so, what properties (e.g. microbial load, community membership) of these microbial communities preclude versus promote intra-amniotic infection? Given the ramifications of the in utero colonization hypothesis, critical evaluation is required. In this study, using multiple modes of microbiologic inquiry (i.e. culture, qPCR, DNA sequencing) and controlling for potential background DNA contamination, we did not find consistent evidence for microbial communities in the placenta and fetal tissues of rhesus macaques.


Genetika ◽  
2021 ◽  
Vol 53 (2) ◽  
pp. 729-737
Author(s):  
Mohammad Vahedi ◽  
Masoud Sheidai

Azoospermia is one of the kinds of male infertility, with clinically the most severe phenotype as the natural conception cannot occur. It has been estimated to affect 0.1 to 1% of all men and 10-15% of men in infertile couples. TEX14 (Testis expressed 14, intercellular bridge forming factor) is a protein coding gene, which is located in human chromosome 17, (17q22). Tex14 gene appears to be crucial for perfect spermatogenesis and functional studies indicate the role of TEX14 in the intercellular bridges between developing male germ cells. The gene contains 32 exons and spans 137 kb. A heterogeneousresultis available on the association TEX14 gene and azoospermia. Therefore, it is suggested to investigate this gene in different populations. We analyzed about 200 men in two categories of azoospermia and healthy persons by RFLP as well as DNA sequencing to indicate an association between rs535296987 in TEX14 and its adjacent nucleotides to azoospermia. We found no significant association based on RFLP data and also by clustering of case and control specimens based on DNA sequencing. In general, a low level of nucleotide variability was observed in DNA sequences. Therefore, both eternity in the studied samples and low degree of mutations in this genetic region, may be the reason for heterogeneous reports on association of TEX14 and azoospermia.


2020 ◽  
Vol 730 ◽  
pp. 139116 ◽  
Author(s):  
Jinyu Hou ◽  
Longhua Wu ◽  
Wuxing Liu ◽  
Yanyan Ge ◽  
Tingting Mu ◽  
...  

2019 ◽  
Vol 67 (7) ◽  
pp. 571
Author(s):  
Zhihao Su ◽  
Liuqiang Wang ◽  
Li Zhuo ◽  
Xiaolong Jiang ◽  
Wenjun Li

Tamarix taklamakanensis is an endangered shrub endemic to the Tarim Basin and adjacent Kumtag Desert in north-western China. Here, we used two chloroplast DNA sequences, namely, psbA-trnH and trnS-trnG, to examine the genetic diversity patterns of this species across its entire covered range. A total of nineteen haplotypes were detected. The total gene diversity within the species is high. Genetic variation mainly occurred among populations, SAMOVA groups, and geographic regions. The test for isolation-by-distance showed a significant correlation between genetic and geographical distances, and the genetic landscape shape analysis showed a significant genetic divergence between the Tarim Basin and Kumtag Desert. T. taklamakanensis likely had a potential geographic range during the Last Glacial Maximum period that was much smaller than the present range predicted by ecological niche modelling. The cold and dry climate during the glacial periods of the Quaternary might be a driver of the genetic isolation and divergence detected within T. taklamakanensis, and climatic oscillations might account for the habitat fragmentation of the species. Within the inner of the basin, populations have a higher level of genetic diversity and harbor most of this genetic diversity, thus a nature reserves should be set up in this area for the in situ conservation. In addition, five genetically distinct groups within T. taklamakanensis should be treated as different management units (MUs) when implementing conservation activities.


2020 ◽  
Vol 96 (9) ◽  
Author(s):  
Ragnhild I Vestrum ◽  
Kari J K Attramadal ◽  
Olav Vadstein ◽  
Madeleine Stenshorne Gundersen ◽  
Ingrid Bakke

ABSTRACT Many studies demonstrate the importance of the commensal microbiomes to animal health and development. However, the initial community assembly process is poorly understood. It is unclear to what extent the hosts select for their commensal microbiota, whether stochastic processes contribute, and how environmental conditions affect the community assembly. We investigated community assembly in Atlantic cod larvae exposed to distinct microbial metacommunities. We aimed to quantify ecological processes influencing community assembly in cod larvae and to elucidate the complex relationship between the bacteria of the environment and the fish. Selection within the fish was the major determinant for community assembly, but drift resulted in inter-individual variation. The environmental bacterial communities were highly dissimilar from those associated with the fish. Still, differences in the environmental bacterial communities strongly influenced the fish communities. The most striking difference was an excessive dominance of a single OTU (Arcobacter) for larvae reared in two of the three systems. These larvae were exposed to environments with higher fractions of opportunistic bacteria, and we hypothesise that detrimental host–microbe interactions might have made the fish susceptible to Arcobacter colonisation. Despite strong selection within the host, this points to a possibility to steer the metacommunity towards mutualistic host–microbe interactions and improved fish health and survival.


2014 ◽  
Vol 58 (2) ◽  
pp. 79-85 ◽  
Author(s):  
Sona Jain ◽  
Giulia Marchioro ◽  
Lucyana Mendonça ◽  
Marcus Batista ◽  
Edilson Araujo

Abstract Propolis is produced by the honeybees by using resin and other plant secretions. Propolis from different geographical regions have different chemical compositions. This is because the chemical constituents of propolis depend on the vegetation surrounding the apiary. In this report we present a new approach using DNA barcoding for the identification of the botanical origin of propolis. Red propolis samples were collected at different times of the year from the state of Sergipe situated in Northeast Brazil. Extraction of the DNA from propolis was made using a CTA B method. Amplification was done using ITS 2 universal primers, followed by DNA sequencing. Sequence analysis confirmed the presence of Dalbergia ecastaphyllum in the Brazilian red propolis. Formononetin is a chemical marker for the Brazillian red propolis and D. ecastaphyllum. Propolis samples analysed by DNA sequencing, were also checked by Ultra-Fast Liquid Chromatography for the presence of formononetin. Peaks corresponding to formononetin were observed in all the analysed propolis samples. This is the first report of the botanical origin of propolis using DNA technology.


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