scholarly journals Study of Symbiont Bacteria of Acropora digitifera Coral From Ciletuh Bay, Sukabumi by Using Culture and Molecular Approach

Omni-Akuatika ◽  
2019 ◽  
Vol 15 (2) ◽  
pp. 106
Author(s):  
Nurfitri Nurfitri ◽  
Fiddy Semba Prasetiya ◽  
Indah Riyantini ◽  
Yuniar Mulyani ◽  
Sulastri Arsad ◽  
...  

Bacteria are one of the prokaryotic microorganisms that are symbiotic with coral reefs. These microorganisms help corals in secreting mucus layers which are used as a place to live for bacteria and control the presence of pathogenic bacteria in corals. The purpose of this study was to determine the diversity of bacterial communities associated with Acropora digitifera corals in Ciletuh bay, West Java, by culture approach. Sampling was carried out at a depth of 4 meters. Morphology-based identification and molecular approach based on sequence of the small ribosomal unit (16S) rRNA gene were used to determine the bacterial species in the samples. A total of six pure isolates were identified based on morphological observation and the molecular DNA characteristics from three of them were identified with 16S rRNA gene sequences. The identification using 16S rRNA gene showed that the isolate ACD.P4.PH7.P had a close relationship with the BF strain and zb strain of Bacillus flexus (acc number MH569560.1) with a similarity of 85.44 %. While ACD.P4.PH9.P isolate has a close relationship with Bacillus sp. c234 (acc number FJ950647.1) with a similarity of 98.50 %. Additionally, ACD.P4.PH9.K isolates closely related to Bacillus sp. of strain 6RM1 (acc number MK134607.1) with a similarity of 94.78 %. This study also revealed that both microscopic identifications by morphological traits and molecular approach using 16S rRNA gene can be used in bacterial diversity assessment.

2008 ◽  
Vol 74 (13) ◽  
pp. 3969-3976 ◽  
Author(s):  
Jingrang Lu ◽  
Jorge W. Santo Domingo ◽  
Regina Lamendella ◽  
Thomas Edge ◽  
Stephen Hill

ABSTRACT In spite of increasing public health concerns about the potential risks associated with swimming in waters contaminated with waterfowl feces, little is known about the composition of the gut microbial community of aquatic birds. To address this, a gull 16S rRNA gene clone library was developed and analyzed to determine the identities of fecal bacteria. Analysis of 282 16S rRNA gene clones demonstrated that the gull gut bacterial community is mostly composed of populations closely related to Bacilli (37%), Clostridia (17%), Gammaproteobacteria (11%), and Bacteriodetes (1%). Interestingly, a considerable number of sequences (i.e., 26%) were closely related to Catellicoccus marimammalium, a gram-positive, catalase-negative bacterium. To determine the occurrence of C. marimammalium in waterfowl, species-specific 16S rRNA gene PCR and real-time assays were developed and used to test fecal DNA extracts from different bird (n = 13) and mammal (n = 26) species. The results showed that both assays were specific to gull fecal DNA and that C. marimammalium was present in gull fecal samples collected from the five locations in North America (California, Georgia, Ohio, Wisconsin, and Toronto, Canada) tested. Additionally, 48 DNA extracts from waters collected from six sites in southern California, Great Lakes in Michigan, Lake Erie in Ohio, and Lake Ontario in Canada presumed to be impacted with gull feces were positive by the C. marimammalium assay. Due to the widespread presence of this species in gulls and environmental waters contaminated with gull feces, targeting this bacterial species might be useful for detecting gull fecal contamination in waterfowl-impacted waters.


2017 ◽  
Vol 5 (1) ◽  
pp. 72-80
Author(s):  
Umesh Prasad Shrivastava

The rhizobacteria were isolated from rhizosphere of rice plant of different fields of 4 districts of Nepal and 5 districts of Bihar and Uttar Pradesh, adjoining states of India with Nepal. The DGGE analysis was performed for diversity analysis. For the construction of dendrogram, 16S rRNA gene was amplified by two different sets of primers. The DGGE ladder consisting of PCR amplified products of nine pure bacterial cultures were obtained. The first DGGE ladder was prepared by 400 bp fragment of 16S rDNA with GC clamp and the second DGGE ladder was prepared with 200 bp fragment of 16S rDNA with GC clamp. The perpendicular DGGE of these amplicons based on their melting behavior clearly demonstrated separation of different isolates. The 16S rDNA fragment amplified with primer set of V2-V3 regions with GC clamp showed separation between 40-60% of denaturant. The DGGE profile based on primer set F352T and 519r for various bacteria present in soil samples of 5 districts of India and 4 districts of Nepal revealed that the number of bands which might be specific for diazotrophic isolates varied from 2 to 11. The dendrogram constructed based on DGGE profile of various samples of 5 districts of India and 4 districts of Nepal showed that all the samples could be clustered in nine groups with 58-96% similarity to each other. Among all these 37 samples, only Var-4 and Var-5 showed 100% similarity, no other samples from any site showed 100% similarity. Int. J. Appl. Sci. Biotechnol. Vol 5(1): 72-80


2010 ◽  
Vol 56 (12) ◽  
pp. 1040-1049 ◽  
Author(s):  
Michal Slany ◽  
Martina Vanerkova ◽  
Eva Nemcova ◽  
Barbora Zaloudikova ◽  
Filip Ruzicka ◽  
...  

High-resolution melting analysis (HRMA) is a fast (post-PCR) high-throughput method to scan for sequence variations in a target gene. The aim of this study was to test the potential of HRMA to distinguish particular bacterial species of the Staphylococcus genus even when using a broad-range PCR within the 16S rRNA gene where sequence differences are minimal. Genomic DNA samples isolated from 12 reference staphylococcal strains ( Staphylococcus aureus , Staphylococcus capitis , Staphylococcus caprae , Staphylococcus epidermidis , Staphylococcus haemolyticus , Staphylococcus hominis , Staphylococcus intermedius , Staphylococcus saprophyticus , Staphylococcus sciuri , Staphylococcus simulans , Staphylococcus warneri , and Staphylococcus xylosus ) were subjected to a real-time PCR amplification of the 16S rRNA gene in the presence of fluorescent dye EvaGreen™, followed by HRMA. Melting profiles were used as molecular fingerprints for bacterial species differentiation. HRMA of S. saprophyticus and S. xylosus resulted in undistinguishable profiles because of their identical sequences in the analyzed 16S rRNA region. The remaining reference strains were fully differentiated either directly or via high-resolution plots obtained by heteroduplex formation between coamplified PCR products of the tested staphylococcal strain and phylogenetically unrelated strain.


Author(s):  
Chen Zheng-li ◽  
Peng Yu ◽  
Wu Guo-sheng ◽  
Hong Xu-Dong ◽  
Fan Hao ◽  
...  

Abstract Burns destroy the skin barrier and alter the resident bacterial community, thereby facilitating bacterial infection. To treat a wound infection, it is necessary to understand the changes in the wound bacterial community structure. However, traditional bacterial cultures allow the identification of only readily growing or purposely cultured bacterial species and lack the capacity to detect changes in the bacterial community. In this study, 16S rRNA gene sequencing was used to detect alterations in the bacterial community structure in deep partial-thickness burn wounds on the back of Sprague-Dawley rats. These results were then compared with those obtained from the bacterial culture. Bacterial samples were collected prior to wounding and 1, 7, 14, and 21 days after wounding. The 16S rRNA gene sequence analysis showed that the number of resident bacterial species decreased after the burn. Both resident bacterial richness and diversity, which were significantly reduced after the burn, recovered following wound healing. The dominant resident strains also changed, but the inhibition of bacterial community structure was in a non-volatile equilibrium state, even in the early stage after healing. Furthermore, the correlation between wound and environmental bacteria increased with the occurrence of burns. Hence, the 16S rRNA gene sequence analysis reflected the bacterial condition of the wounds better than the bacterial culture. 16S rRNA sequencing in the Sprague-Dawley rat burn model can provide more information for the prevention and treatment of burn infections in clinical settings and promote further development in this field.


Plant Disease ◽  
2021 ◽  
Author(s):  
Qi Wei ◽  
Jie Li ◽  
Shuai Yang ◽  
Wenzhong Wang ◽  
Fanxiang Min ◽  
...  

Common scab (CS) caused by Streptomyces spp. is a significant soilborne potato disease that results in tremendous economic losses globally. Identification of CS-associated species of the genus Streptomyces can enhance understanding of the genetic variation of these bacterial species and is necessary for the control of this epidemic disease. The present study isolated Streptomyces strain 6-2-1(1) from scabby potatoes in Keshan County, Heilongjiang Province, China. PCR analysis confirmed that the strain harbored the characteristic Streptomyces pathogenicity island (PAI) genes (txtA, txtAB, nec1, and tomA). Pathogenicity assays proved that the strain caused typical scab lesions on potato tuber surfaces and necrosis on radish seedlings and potato slices. Subsequently, the strain was systemically characterized at morphological, physiological, biochemical and phylogenetic levels. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 6-2-1(1) shared 99.86% sequence similarity with Streptomyces rhizophilus JR-41T, isolated initially from bamboo in rhizospheric soil in Korea. PCR amplification followed by Sanger sequencing of the 16S rRNA gene of 164 scabby potato samples collected in Heilongjiang Province from 2019 to 2020 demonstrated that approximately 2% of the tested samples were infected with S. rhizophilus. Taken together, these results demonstrate that S. rhizophilus is capable of causing potato CS disease and may pose a potential challenge to potato production in Heilongjiang Province of China.


Marine Drugs ◽  
2019 ◽  
Vol 17 (11) ◽  
pp. 635 ◽  
Author(s):  
Joko T. Wibowo ◽  
Matthias Y. Kellermann ◽  
Dennis Versluis ◽  
Masteria Y. Putra ◽  
Tutik Murniasih ◽  
...  

In order to minimize re-discovery of already known anti-infective compounds, we focused our screening approach on understudied, almost untapped marine environments including marine invertebrates and their associated bacteria. Therefore, two sea cucumber species, Holothuria leucospilota and Stichopus vastus, were collected from Lampung (Indonesia), and 127 bacterial strains were identified by partial 16S rRNA-gene sequencing analysis and compared with the NCBI database. In addition, the overall bacterial diversity from tissue samples of the sea cucumbers H. leucospilota and S. vastus was analyzed using the cultivation-independent Illumina MiSEQ analysis. Selected bacterial isolates were grown to high densities and the extracted biomass was tested against a selection of bacteria and fungi as well as the hepatitis C virus (HCV). Identification of putative bioactive bacterial-derived compounds were performed by analyzing the accurate mass of the precursor/parent ions (MS1) as well as product/daughter ions (MS2) using high resolution mass spectrometry (HRMS) analysis of all active fractions. With this attempt we were able to identify 23 putatively known and two previously unidentified precursor ions. Moreover, through 16S rRNA-gene sequencing we were able to identify putatively novel bacterial species from the phyla Actinobacteria, Proteobacteria and also Firmicutes. Our findings suggest that sea cucumbers like H. leucospilota and S. vastus are promising sources for the isolation of novel bacterial species that produce compounds with potentially high biotechnological potential.


2015 ◽  
Vol 65 (Pt_6) ◽  
pp. 1929-1934 ◽  
Author(s):  
Morgane Rossi-Tamisier ◽  
Samia Benamar ◽  
Didier Raoult ◽  
Pierre-Edouard Fournier

Modern bacterial taxonomy is based on a polyphasic approach that combines phenotypic and genotypic characteristics, including 16S rRNA sequence similarity. However, the 95 % (for genus) and 98.7 % (for species) sequence similarity thresholds that are currently recommended to classify bacterial isolates were defined by comparison of a limited number of bacterial species, and may not apply to many genera that contain human-associated species. For each of 158 bacterial genera containing human-associated species, we computed pairwise sequence similarities between all species that have names with standing in nomenclature and then analysed the results, considering as abnormal any similarity value lower than 95 % or greater than 98.7 %. Many of the current bacterial species with validly published names do not respect the 95 and 98.7 % thresholds, with 57.1 % of species exhibiting 16S rRNA gene sequence similarity rates ≥98.7 %, and 60.1 % of genera containing species exhibiting a 16S rRNA gene sequence similarity rate <95 %. In only 17 of the 158 genera studied (10.8 %), all species respected the 95 and 98.7 % thresholds. As we need powerful and reliable taxonomical tools, and as potential new tools such as pan-genomics have not yet been fully evaluated for taxonomic purposes, we propose to use as thresholds, genus by genus, the minimum and maximum similarity values observed among species.


2017 ◽  
Vol 33 (2) ◽  
pp. 309-318 ◽  
Author(s):  
Pilar Mediano ◽  
Leonides Fernández ◽  
Esther Jiménez ◽  
Rebeca Arroyo ◽  
Irene Espinosa-Martos ◽  
...  

Background: Lactational mastitis constitutes a significant cause of premature weaning. However, its etiology, linked to the presence of pathogenic microorganisms, has been scarcely reported. Research aim: The aim of this study was to describe the microbial diversity in milk samples from women suffering from lactational mastitis and to identify more accurately a collection of isolates belonging to coagulase-negative staphylococci, streptococci, and coryneform bacteria. Methods: This is a cross-sectional descriptive one-group study. A total of 5,009 isolates from 1,849 mastitis milk samples was identified by culture, biochemical, and/or molecular methods at the species or genus level. A more precise identification of a collection of 211 isolates was carried out by 16S rRNA gene sequencing. Results: Mean total bacterial count in milk samples was 4.11 log10 colony-forming units/ml, 95% confidence interval [4.08, 4.15]. Staphylococcus epidermidis was the most common species being isolated from 91.56% of the samples, whereas Staphylococcus aureus was detected in 29.74%. Streptococci and corynebacteria constituted the second (70.20%) and third (16.60%) most prevalent bacterial groups, respectively, found in this study. In contrast, Candida spp. was present in only 0.54% of the samples. Sequencing of the 16S rRNA gene revealed a high diversity of bacterial species among identified isolates. Conclusion: Many coagulase-negative staphylococci, viridans group streptococci, and corynebacteria, usually dismissed as contaminant bacteria, may play an important role as etiologic agents of mastitis. Proper diagnosis of mastitis should be established after performing microbiological testing of milk based on standardized procedures. A reliable analysis must identify the mastitis-causing pathogen(s) at the species level and its(their) concentration(s).


2007 ◽  
Vol 57 (10) ◽  
pp. 2221-2227 ◽  
Author(s):  
Sören Muurholm ◽  
Sylvie Cousin ◽  
Orsola Päuker ◽  
Evelyne Brambilla ◽  
Erko Stackebrandt

Five isolates that were related phylogenetically to members of the genus Pedobacter were isolated from freshwater of the hard-water creek Westerhöfer Bach, North Germany. The five strains (WB 2.1-25T, WB 2.3-71T, WB 3.3-3T, WB 3.3-22T and WB 2.3-45T) were Gram-negative and chemoheterotrophic, with rod-shaped cells. Most of their metabolic properties matched those given in the description of the genus Pedobacter. Consistent with the genus description, their fatty acids included mainly iso-C15 : 0 and summed feature 3 (C16 : 1 ω7c, iso-C15 : 0 2-OH or both); C16 : 1 ω5c, C16 : 0, iso-C15 : 0 3-OH, C16 : 0 3-OH and iso-C17 : 0 3-OH were present in smaller amounts. The major isoprenoid quinone was menaquinone 7. With one exception, binary similarity values of the almost complete 16S rRNA gene sequences determined among the isolates as well as between the isolates and type strains of Pedobacter species were lower than 98.5 %. The only exception was the close relationship between Pedobacter caeni DSM 16990T and strain WB 2.3-45T (99.2 % similarity). DNA–DNA reassociation values determined for this pair of strains was 29.8 %, indicating that strain WB 2.3-45T represents a unique genospecies. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains WB 2.1-25T and WB 2.3-71T form a group that is moderately related to P. caeni and strain WB 2.3-45T (98.5 % similarity). Strains WB 3.3-3T and WB 3.3-22T (98.5 % similarity) branched separately from these four organisms. The five phylogenetically isolated strains differed from each other as well as from the type strain of the type species (Pedobacter heparinus DSM 2366T) and some related representatives of the genus in several metabolic reactions and cultural parameters. On the basis of phenotypic and phylogenetic distinctiveness, five novel species are proposed: Pedobacter duraquae sp. nov., with WB 2.1-25T (=DSM 19034T=CIP 109481T) as the type strain; Pedobacter westerhofensis sp. nov., with WB 3.3-22T (=DSM 19036T=CIP 109479T) as the type strain; Pedobacter metabolipauper sp. nov., with WB 2.3-71T (=DSM 19035T=CIP 109480T) as the type strain; Pedobacter hartonius sp. nov., with WB 3.3-3T (=DSM 19033T=CIP 109468T) as the type strain; and Pedobacter steynii sp. nov., with WB 2.3-45T (=DSM 19110T=CIP 109507T) as the type strain.


2012 ◽  
Vol 62 (Pt_3) ◽  
pp. 632-637 ◽  
Author(s):  
Song-Ih Han ◽  
Hyo-Jin Lee ◽  
Hae-Ran Lee ◽  
Ki-Kwang Kim ◽  
Kyung-Sook Whang

Three exopolysaccharide-producing bacteria, designated strains DRP28T, DRP29 and DRP31, were isolated from the rhizoplane of Angelica sinensis from the Geumsan, Republic of Korea. Cells were straight rods, Gram reaction-negative, aerobic, non-motile, and catalase- and oxidase- positive. Flexirubin-type pigments were absent. Phylogenetic analysis of the 16S rRNA gene indicated that these bacteria belong to the genus Mucilaginibacter in the phylum Bacteroidetes. 16S rRNA gene sequence similarities to strains of recognized species of the genus Mucilaginibacter were 93.8–97.4 %. The major fatty acids were iso-C15 : 0 and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH). The strains contained MK-7 as the major isoprenoid quinone. Strains DRP28T, DRP29 and DRP31 formed a single, distinct genomospecies with DNA G+C contents of 41.9–42.7 mol% and DNA hybridization values of 82.6–86.8 %; the strains exhibited DNA–DNA hybridization values of only 20.4–41.3 % with related species of the genus Mucilaginibacter. On the basis of evidence presented in this study, strains DRP28T, DRP29 and DRP31 were considered to represent a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter polysacchareus sp. nov. is proposed. The type strain is DRP28T ( = KACC 15075T  = NBRC 107757T).


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