scholarly journals Possible Origins of CTnBST, a Conjugative Transposon Found Recently in a Human Colonic Bacteroides Strain

2007 ◽  
Vol 73 (13) ◽  
pp. 4226-4233 ◽  
Author(s):  
David J. Schlesinger ◽  
Nadja B. Shoemaker ◽  
Abigail A. Salyers
Keyword(s):  
Mobile Element ◽  
Coding Region ◽  
Positive Bacterium ◽  
Gram Positive ◽  
High Sequence Identity ◽  
Conjugative Transposon ◽  
Gram Positive Bacteria ◽  
Hybrid Element ◽  
Arcanobacterium Pyogenes ◽  
Bacteroides Strain

ABSTRACT A previous survey of Bacteroides isolates suggested that the ermB gene entered Bacteroides spp. recently. Previously, ermB had been found almost exclusively in gram-positive bacteria. In one Bacteroides strain, ermB was located on 100-kb conjugative transposon (CTn) CTnBST. To assess the possible origin of this CTn, we obtained the full DNA sequence of CTnBST and used this information to investigate its possible origins. Over one-half of CTnBST had high sequence identity to a putative CTn found in the genome of Bacteroides fragilis YCH46. This included the ends of the CTn and genes involved in integration, transfer, and excision. However, the region around the ermB gene contained genes that appeared to originate from gram-positive organisms. In particular, a 7-kb segment containing the ermB gene was 100% identical to an ermB region found in the genome of the gram-positive bacterium Arcanobacterium pyogenes. A screen of Bacteroides isolates whose DNA cross-hybridized with a CTnBST probe revealed that several isolates did not carry the 7-kb region, implying that the acquisition of this region may be more recent than the acquisition of the entire CTnBST element by Bacteroides spp. We have also identified other Bacteroides isolates that carry a slightly modified 7-kb region but have no other traces of CTnBST. Thus, it is possible that this 7-kb region could itself be part of a mobile element that has inserted in a Bacteroides CTn. Our results show that CTnBST is a hybrid element which has acquired a portion of its coding region from gram-positive bacteria but which may originally have come from Bacteroides spp. or some related species.

Influence of Cell Wall Composition on the Fossilisation of Bacteria and the Implications for the Search for Early Life Forms

1997 ◽  
Vol 161 ◽  
pp. 491-504 ◽  
Author(s):  
Frances Westall
Keyword(s):  
Cell Wall ◽  
Life Forms ◽  
Cation Binding ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Transmission Electron ◽  
Hydrothermal Sediments ◽  
Identification Of Bacteria ◽  
The Difference

AbstractThe oldest cell-like structures on Earth are preserved in silicified lagoonal, shallow sea or hydrothermal sediments, such as some Archean formations in Western Australia and South Africa. Previous studies concentrated on the search for organic fossils in Archean rocks. Observations of silicified bacteria (as silica minerals) are scarce for both the Precambrian and the Phanerozoic, but reports of mineral bacteria finds, in general, are increasing. The problems associated with the identification of authentic fossil bacteria and, if possible, closer identification of bacteria type can, in part, be overcome by experimental fossilisation studies. These have shown that not all bacteria fossilise in the same way and, indeed, some seem to be very resistent to fossilisation. This paper deals with a transmission electron microscope investigation of the silicification of four species of bacteria commonly found in the environment. The Gram positiveBacillus laterosporusand its spore produced a robust, durable crust upon silicification, whereas the Gram negativePseudomonas fluorescens, Ps. vesicularis, andPs. acidovoranspresented delicately preserved walls. The greater amount of peptidoglycan, containing abundant metal cation binding sites, in the cell wall of the Gram positive bacterium, probably accounts for the difference in the mode of fossilisation. The Gram positive bacteria are, therefore, probably most likely to be preserved in the terrestrial and extraterrestrial rock record.

scholarly journals Distribution of the ermG Gene among Bacterial Isolates from Porcine Intestinal Contents

2005 ◽  
Vol 71 (8) ◽  
pp. 4930-4934 ◽  
Author(s):  
Yanping Wang ◽  
Gui-Rong Wang ◽  
Nadja B. Shoemaker ◽  
Terence R. Whitehead ◽  
Abigail A. Salyers
Keyword(s):  
Insertion Sequence ◽  
Bacillus Sphaericus ◽  
Gram Positive ◽  
Sequence Element ◽  
Conjugative Transposon ◽  
Gram Positive Bacteria ◽  
First Finding ◽  
Intestinal Contents ◽  
Porcine Feces ◽  
Insertion Sequence Element

ABSTRACT The ermG gene was first found in the soil bacterium Bacillus sphaericus. More recently, it was found in several human intestinal Bacteroides species. We report here the first finding of ermG genes in gram-positive bacteria isolated from porcine feces and from under-barn manure pits used to store porcine wastes. The porcine ermG sequences were identical to the sequence of the B. sphaericus ermG gene except that six of the seven ermG-containing strains contained an insertion sequence element insertion in the C-terminal end of the gene. The porcine ermG genes were found in three different gram-positive genera, an indication that it is possible that the gene is being spread by horizontal gene transfer. A segment of a Bacteroides conjugative transposon that carries an ermG gene cross-hybridized with DNA from six of the seven porcine isolates, but the restriction patterns in the porcine strains were different from that of the Bacteroides conjugative transposon.

scholarly journals ppGpp negatively impacts ribosome assembly affecting growth and antimicrobial tolerance in Gram-positive bacteria

2016 ◽  
Vol 113 (12) ◽  
pp. E1710-E1719 ◽  
Author(s):  
Rebecca M. Corrigan ◽  
Lauren E. Bellows ◽  
Alison Wood ◽  
Angelika Gründling
Keyword(s):  
Stringent Response ◽  
Ribosome Assembly ◽  
Bacterial Survival ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Guanosine Tetraphosphate ◽  
Target Proteins ◽  
Gram Positive Bacteria ◽  
Ribosome Inactivation

The stringent response is a survival mechanism used by bacteria to deal with stress. It is coordinated by the nucleotides guanosine tetraphosphate and pentaphosphate [(p)ppGpp], which interact with target proteins to promote bacterial survival. Although this response has been well characterized in proteobacteria, very little is known about the effectors of this signaling system in Gram-positive species. Here, we report on the identification of seven target proteins for the stringent response nucleotides in the Gram-positive bacteriumStaphylococcus aureus. We demonstrate that the GTP synthesis enzymes HprT and Gmk bind with a high affinity, leading to an inhibition of GTP production. In addition, we identified five putative GTPases—RsgA, RbgA, Era, HflX, and ObgE—as (p)ppGpp target proteins. We show that RsgA, RbgA, Era, and HflX are functional GTPases and that their activity is promoted in the presence of ribosomes but strongly inhibited by the stringent response nucleotides. By characterizing the function of RsgA in vivo, we ascertain that this protein is involved in ribosome assembly, with anrsgAdeletion strain, or a strain inactivated for GTPase activity, displaying decreased growth, a decrease in the amount of mature 70S ribosomes, and an increased level of tolerance to antimicrobials. We additionally demonstrate that the interaction of ppGpp with cellular GTPases is not unique to the staphylococci, as homologs fromBacillus subtilisandEnterococcus faecalisretain this ability. Taken together, this study reveals ribosome inactivation as a previously unidentified mechanism through which the stringent response functions in Gram-positive bacteria.

Inhibition of Aspergillus flavus and Selected Gram-positive Bacteria by Chelation of Essential Metal Cations by Polyphosphates

1991 ◽  
Vol 54 (5) ◽  
pp. 360-365 ◽  
Author(s):  
S.J. KNABEL ◽  
H.W. WALKER ◽  
P.A. HARTMAN
Keyword(s):  
Aspergillus Flavus ◽  
Binding Sites ◽  
Iron Supplementation ◽  
Cation Binding ◽  
Gram Negative Bacteria ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Tetrasodium Pyrophosphate ◽  
Gram Positive Bacteria ◽  
And Staphylococcus Aureus

A simple well-plate technique was utilized to determine the effect of various metals on the growth of microorganisms in media containing different polyphosphates. Aspergillus flavus and four gram-positive bacteria were completely inhibited by media containing 1% of various alkaline polyphosphates, whereas four gram-negative bacteria were not. Significant differences were observed between the type of polyphosphate added, the type of metal added, and the species of gram-positive bacterium inhibited. The addition of Mg2+ stimulated growth of A. flavus and Bacillus cereus in the presence of tetrasodium pyrophosphate, whereas Mn2+ permitted growth of A. flavus and Staphylococcus aureus in the presence of sodium hexametaphosphate. Iron supplementation allowed the growth of S. aureus and Listeria monocytogenes on media containing 1 % tetrasodium pyrophosphate. A method for determining the amount of calcium and magnesium in water was modified to detect free Mg2+ by replacing EDTA with phosphate. The addition of free Mg2+, but not Mg2+ chelated by tetrasodium pyrophosphate, permitted the growth of B. cereus on a medium containing tetrasodium pyrophosphate. It is speculated that polyphosphates specifically inhibited A. flavus and gram-positive bacteria by removing essential metals from cation-binding sites located within their cell walls.

scholarly journals A synthetic 5,3-cross-link in the cell wall of rod-shaped Gram-positive bacteria

2021 ◽  
Vol 118 (11) ◽  
pp. e2100137118
Author(s):  
David A. Dik ◽  
Nan Zhang ◽  
Emily J. Sturgell ◽  
Brittany B. Sanchez ◽  
Jason S. Chen ◽  
...  
Keyword(s):  
Cell Wall ◽  
Building Blocks ◽  
Cross Link ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Novel Approach ◽  
Cross Links ◽  
Link Formation ◽  
Cell Wall Architecture

Gram-positive bacteria assemble a multilayered cell wall that provides tensile strength to the cell. The cell wall is composed of glycan strands cross-linked by nonribosomally synthesized peptide stems. Herein, we modify the peptide stems of the Gram-positive bacterium Bacillus subtilis with noncanonical electrophilic d-amino acids, which when in proximity to adjacent stem peptides form novel covalent 5,3-cross-links. Approximately 20% of canonical cell-wall cross-links can be replaced with synthetic cross-links. While a low level of synthetic cross-link formation does not affect B. subtilis growth and phenotype, at higher levels cell growth is perturbed and bacteria elongate. A comparison of the accumulation of synthetic cross-links over time in Gram-negative and Gram-positive bacteria highlights key differences between them. The ability to perturb cell-wall architecture with synthetic building blocks provides a novel approach to studying the adaptability, elasticity, and porosity of bacterial cell walls.

scholarly journals Contemporary threats of bacterial infections in freshwater fish

2018 ◽  
Vol 62 (3) ◽  
pp. 261-267 ◽  
Author(s):  
Agnieszka Pękala-Safińska
Keyword(s):  
Bacterial Infections ◽  
Clinical Signs ◽  
Freshwater Ecosystems ◽  
Streptococcus Iniae ◽  
Gram Negative Bacteria ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Fish Pathology ◽  
Dynamic Variations

AbstractChanges occurring in freshwater ecosystems seem to be fundamental in the development of all microorganisms, including those pathogenic to fish. This has been especially evident in recent years during which dynamic variations in bacterial fish pathology have been observed. Gram-negative bacteria commonly known to be pathogenic to fish, likeAeromonasspp.,Flavobacteriumspp.,Pseudomonasspp., andShewanella putrefaciensare replaced by other species, which until now have not been known to be virulent or even conditionally pathogenic to fish. Nowadays, among these other speciesAcinetobacterspp.,Plesiomonas shigelloides,Sphingomonas paucimobilis, andStenotrophomonas maltophiliaare the most frequently isolated from fish exhibiting clinical signs of disease. Two Gram-positive bacteria have become pathogens of particular importance in fish pathology in Poland:Lactococcus garviaeandStreptococcus iniae. In addition, infections caused by the Gram-positive bacteriumKocuria rhizophilahave appeared in recent years. This bacterium has not been known until now to be pathogenic to fish. Therefore, this infection could be called an emergent disease.

scholarly journals A New Bacteroides Conjugative Transposon That Carries an ermB Gene

2003 ◽  
Vol 69 (11) ◽  
pp. 6455-6463 ◽  
Author(s):  
Anamika Gupta ◽  
Hera Vlamakis ◽  
Nadja Shoemaker ◽  
Abigail A. Salyers
Keyword(s):  
Antibiotic Resistance Genes ◽  
Open Reading Frames ◽  
Rrna Gene ◽  
Erythromycin Resistance ◽  
Gram Positive ◽  
Amino Acid Sequence Level ◽  
Conjugative Transposon ◽  
Pulsed Field ◽  
Gram Positive Bacteria ◽  
Ermb Gene

ABSTRACT The erythromycin resistance gene ermB has been found in a variety of gram-positive bacteria. This gene has also been found in Bacteroides species but only in six recently isolated strains; thus, the gene seems to have entered this genus only recently. One of the six Bacteroides ermB-containing isolates, WH207, could transfer ermB to Bacteroides thetaiotaomicron strain BT4001 by conjugation. WH207 was identified as a Bacteroides uniformis strain based on the sequence of its 16S rRNA gene. Results of pulsed-field gel electrophoresis experiments demonstrated that the transferring element was normally integrated into the Bacteroides chromosome. The element was estimated from pulsed-field gel data to be about 100 kb in size. Since the element appeared to be a conjugative transposon (CTn), it was designated CTnBST. CTnBST was able to mobilize coresident plasmids and the circular form of the mobilizable transposon NBU1 to Bacteroides and Escherichia coli recipients. A 13-kb segment that contained ermB was cloned and sequenced. Most of the open reading frames in this region had little similarity at the amino acid sequence level to any proteins in the sequence databases, but a 1,723-bp DNA segment that included a 950-bp segment downstream of ermB had a DNA sequence that was virtually identical to that of a segment of DNA found previously in a Clostridium perfringens strain. This finding, together with the finding that ermB is located on a CTn, supports the hypothesis that CTnBST could have entered Bacteroides from some other genus, possibly from gram-positive bacteria. Moreover, this finding supports the hypothesis that many transmissible antibiotic resistance genes in Bacteroides are carried on CTns.

A group II intron in a conjugative transposon from the gram-positive bacterium, Clostridium difficile

Gene ◽  
1996 ◽  
Vol 174 (1) ◽  
pp. 145-150 ◽  
Author(s):  
Peter Mullany ◽  
Mark Pallen ◽  
Mark Wilks ◽  
John R. Stephen ◽  
Soad Tabaqchali
Keyword(s):  
Clostridium Difficile ◽  
Group Ii Intron ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Conjugative Transposon ◽  
Group Ii

scholarly journals Clinical and Bacteriological Study of Subcutaneous abscesses caused by gram positive bacteria in cow and sheep in Al-Qadissiyia province

2012 ◽  
Vol 11 (2) ◽  
pp. 80
Author(s):  
Y. I. Kh. AL-Tuffyli And M. I. Shekhan
Keyword(s):  
Staphylococcus Aureus ◽  
Fruit Size ◽  
Corynebacterium Pseudotuberculosis ◽  
Gram Positive ◽  
Bacteriological Study ◽  
Anatomical Distribution ◽  
Gram Positive Bacteria ◽  
Two Samples ◽  
Causative Agents ◽  
Arcanobacterium Pyogenes

In spite of the fact that subcutaneous abscesses is occur in sporadical cases and cause low morbidity, A total of 79 (56 and 23) abscesses of cattle and sheep respectively were examined during 12 month from November 2010 to October 2011 for determined an anatomical distribution of subcutaneous abscesses with identification of clinical features and isolation of causative agents that cause these abscesses in cow and sheep in Al-Qadissiyia province. The head was most commonly affected, followed by (glutcal &neck) and chest regions at percentages 80.36%,10.71% and 8.92% respectively in cattle, and 82.6%, 13.03%, and 4.34% respectively in sheep. Also the results demonstrated that there are four types of subcutaneous abscesses vary in size (from a nutmeg fruit size up to a muskmelon).Fifty four samples out 56 abscesses samples of cattle were demonstrated gram positive bacteria only which presented by Staphylococcus aureus, S. epidermidis, S. hycus, Arcanobacterium pyogenes, and Corynebacterium pseudotuberculosis at percentage (33.9 %), (17.8%), (12.6%), (23.2%) and (7.1%) as well as one sample (1.8%) revealed undifferentiated bacteria, the rest two samples (3.6%) don't showed any bacterial growth during culture. In sheep the 23 samples the result showed that Staphylococcus aureus was predominant bacterial isolates followed by Arcanobacterium pyogenes ,and Corynebacterium pseudotuberculosis , S. epidermidis, at percentage (30.4%), (26%), (21.7%) and (17.4%) as well as one sample (4.4%) didn’t revealed any growth.

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