scholarly journals Isolation and characterization of the M.EaeI modification methylase

1986 ◽  
Vol 238 (2) ◽  
pp. 613-616 ◽  
Author(s):  
D Jacobs ◽  
N L Brown
Keyword(s):  
Restriction Endonuclease ◽  
Enterobacter Aerogenes ◽  
Recognition Site ◽  
Cytosine Residue ◽  
Isolation And Characterization ◽  
The Family ◽  
Modification Enzyme

The modification enzyme (M.EaeI) corresponding to the restriction endonuclease EaeI was partially purified from Enterobacter aerogenes PW201. The M.EaeI enzyme methylates the innermost cytosine residue in each strand of the family of related sequences that constitute the EaeI recognition site to give: 5′-Y-G-G-5mC-C-R-3′ where 5mC is 5-methylcytosine. M.EaeI protects these sites against cleavage by HaeIII, and protects overlapping 5′-C-C-G-G-3′ sites against cleavage by both HpaII and MspI.

scholarly journals Isolation and characterization of a bacteriophage F20 virulent to Enterobacter aerogenes

2012 ◽  
Vol 93 (10) ◽  
pp. 2310-2314 ◽  
Author(s):  
Charitra Kumar Mishra ◽  
Tae Jin Choi ◽  
Sun Chul Kang
Keyword(s):  
Room Temperature ◽  
Enterobacter Aerogenes ◽  
Oral Solution ◽  
Isolation And Characterization ◽  
Animal Trials ◽  
Physico Chemical ◽  
The Family ◽  
Linear Dsdna ◽  
Ph Range

An aquatic phage, designated F20, was characterized and its physico-chemical characteristics studied. F20 was specifically virulent to only two strains of Enterobacter aerogenes (ATCC 13048 and the multi-drug-resistant strain K113) among other species tested (n = 15). It was classified in the family Siphoviridae of T1-like viruses and contained a linear dsDNA genome estimated to be 51.5 kbp enclosed by an isometric capsid of 50±2 nm in diameter and a tail of 150±3 nm in length. F20 was able to survive in a broad pH range between 4 and 11, showed potential for future animal trials using oral solution and resisted chloroform and ethanol. It exhibited remarkable stability between room temperature and 70 °C for up to 150 min, and even up to 6 months at room temperature. Knowledge of this phage belonging to the widespread T1-like viruses might be helpful for adopting therapeutic strategies against E. aerogenes.

Isolation and characterization of a newly identified type II restriction endonuclease from a local streptomyces sp. in Taiwan

1998 ◽  
Vol 73 (2-3) ◽  
pp. 231-241
Author(s):  
Kuang-Yu Hu ◽  
Jia-An Wuu ◽  
Ming-Ching Kao ◽  
Yu-Tien Liu ◽  
Shou-Hsiung Pai
Keyword(s):  
Restriction Endonuclease ◽  
Type Ii ◽  
Streptomyces Sp ◽  
Isolation And Characterization

scholarly journals Isolation and Characterization of Two Klebsiella pneumoniae Phages Encoding Divergent Depolymerases

2020 ◽  
Vol 21 (9) ◽  
pp. 3160 ◽  
Author(s):  
Pilar Domingo-Calap ◽  
Beatriz Beamud ◽  
Lucas Mora-Quilis ◽  
Fernando González-Candelas ◽  
Rafael Sanjuán
Keyword(s):  
Klebsiella Pneumoniae ◽  
Multidrug Resistant ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Isolation And Characterization ◽  
The Family ◽  
Important Challenge ◽  
Tail Spike ◽  
Reference Strains

The emergence of multidrug-resistant bacteria is a major global health concern. The search for new therapies has brought bacteriophages into the spotlight, and new phages are being described as possible therapeutic agents. Among the bacteria that are most extensively resistant to current antibiotics is Klebsiella pneumoniae, whose hypervariable extracellular capsule makes treatment particularly difficult. Here, we describe two new K. pneumoniae phages, πVLC5 and πVLC6, isolated from environmental samples. These phages belong to the genus Drulisvirus within the family Podoviridae. Both phages encode a similar tail spike protein with putative depolymerase activity, which is shared among other related phages and probably determines their ability to specifically infect K. pneumoniae capsular types K22 and K37. In addition, we found that phage πVLC6 also infects capsular type K13 and is capable of striping the capsules of K. pneumoniae KL2 and KL3, although the phage was not infectious in these two strains. Genome sequence analysis suggested that the extended tropism of phage πVLC6 is conferred by a second, divergent depolymerase. Phage πVLC5 encodes yet another putative depolymerase, but we found no activity of this phage against capsular types other than K22 and K37, after testing a panel of 77 reference strains. Overall, our results confirm that most phages productively infected one or few Klebsiella capsular types. This constitutes an important challenge for clinical applications.

Isolation and Characterization of Soil Myxobacteria from Nepal

2019 ◽  
Vol 24 (2) ◽  
pp. 7-16
Author(s):  
Nabin Rana ◽  
Saraswoti Khadka ◽  
Bishnu Prasad Marasini ◽  
Bishnu Joshi ◽  
Pramod Poudel ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Antimicrobial Properties ◽  
Antimicrobial Activities ◽  
Rrna Gene ◽  
Isolation And Characterization ◽  
The Family ◽  
Global Concern ◽  
Bacteria And Fungi ◽  
Antimicrobial Metabolites

 Realizing myxobacteria as a potential source of antimicrobial metabolites, we pursued research to isolate myxobacteria showing antimicrobial properties. We have successfully isolated three strains (NR-1, NR-2, NR-3) using the Escherichia coli baiting technique. These isolates showed typical myxobacterial growth characteristics. Phylogenetic analysis showed that all the strains (NR-1, NR-2, NR-3) belong to the family Archangiaceae, suborder Cystobacterineae, and order Myxococcales. Furthermore, 16S rRNA gene sequence similarity searched through BLAST revealed that strain NR-1 showed the closest similarity (91.8 %) to the type strain Vitiosangium cumulatum (NR-156939), NR-2 showed (98.8 %) to the type of Cystobacter badius (NR-043940), and NR-3 showed the closest similarity (83.5 %) to the type of strain Cystobacter fuscus (KP-306730). All isolates showed better growth in 0.5-1 % NaCl and pH around 7.0, whereas no growth was observed at pH 9.0 and below 5.0. All strains showed better growth at 32° C and hydrolyzed starch, whereas casein was efficiently hydrolyzed by NR-1 and NR-2. Besides, preliminary antimicrobial tests from crude extracts showed activities against Gram-positive, Gram-negative bacteria, and fungi. Our findings suggest that the arcane soil habitats of Nepal harbor myxobacteria with the capability to produce diverse antimicrobial activities that may be explored to overcome the rapidly rising global concern about antibiotic resistance.

Cloning and expression of DiT33 from Dirofilaria immitis: a specific and early marker of heartworm infection

Parasitology ◽  
1996 ◽  
Vol 112 (3) ◽  
pp. 331-338 ◽  
Author(s):  
X. Q. Hong ◽  
J. Santiago Mejia ◽  
S. Kumar ◽  
F. B. Perler ◽  
C. K. S. Carlow
Keyword(s):  
Dirofilaria Immitis ◽  
Cloning And Expression ◽  
E Coli ◽  
Spliced Leader ◽  
Isolation And Characterization ◽  
The Family ◽  
Heartworm Infection ◽  
High Level ◽  
Control And Management

SUMMARYDirofilaria immitis is an important filarial parasite of dogs and cats, and a useful model for human filariasis. Current diagnostic tests for heartworm infection in animals rely on the presence of fecund female worms (usually found 6·5 months post-infection or later) and therefore fail to detect pre-patent infections. Putative pepsin inhibitors from 2 filarial parasites of humans namely Onchocerca volvulus (Ov33, Oc3.6, OvDSB) and Brugia malayi (Bm33), have been shown to be useful in diagnosis of onchocerciasis and lymphatic filariasis, respectively. Previous studies have suggested that a homologue exists in D. immitis (DiT33), which may have potential in diagnosis of heartworm infection. In this study, the isolation and characterization of a cDNA clone encoding DiT33 is described.‡ This cDNA contains 12 bases of the nematode-specific 22 nucleotide spliced leader sequence and encodes a 26·4 kDa-protein with a high level of similarity (87–89%) to other filarial members of the family. DJT33 was over-expressed in E. coli as a fusion with the maltose-binding protein and serological analysis was performed using a panel of clinically defined dog sera. The findings of this study indicate that DiT33 is a promising antigen for the early detection of D. immitis and may be a valuable tool in the control and management of heartworm infection.

Isolation and characterization of microsatellites inNeogobius kessleri(Perciformes, Gobiidae) and cross-species amplification within the family Gobiidae

2007 ◽  
Vol 7 (4) ◽  
pp. 701-704 ◽  
Author(s):  
MARTINA VYSKOČILOVÁ ◽  
MARKÉTA ONDRAČKOVÁ ◽  
ANDREA ŠIMKOVÁ ◽  
JEAN-FRANÇOIS MARTIN
Keyword(s):  
Isolation And Characterization ◽  
The Family

Isolation and characterization of bacteriophages specific to hydrogen-sulfide-producing bacteria

2013 ◽  
Vol 59 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Chao Gong ◽  
Spencer Heringa ◽  
Randhir Singh ◽  
Jinkyung Kim ◽  
Xiuping Jiang
Keyword(s):  
Hydrogen Sulfide ◽  
Lag Phase ◽  
Restriction Enzyme Digestion ◽  
Isolation And Characterization ◽  
The Family ◽  
Processing Plants ◽  
Specific Bacteriophage ◽  
Myoviridae Family ◽  
Restriction Enzyme Digestion Analysis

The objectives of this study were to isolate and characterize bacteriophages specific to hydrogen-sulfide-producing bacteria (SPB) from raw animal materials, and to develop a SPB-specific bacteriophage cocktail for rendering application. Meat, chicken offal, and feather samples collected from local supermarkets and rendering processing plants were used to isolate SPB (n = 142). Bacteriophages (n = 52) specific to SPB were isolated and purified from the above samples using 18 of those isolated SPB strains as hosts. The host ranges of bacteriophages against 5 selected SPB strains (Escherichia coli, Citrobacter freundii, and Hafnia alvei) were determined. Electron microscopy observation of 9 phages selected for the phage cocktail revealed that 6 phages belonged to the family of Siphoviridae and 3 belonged to the Myoviridae family. Restriction enzyme digestion analysis with endonuclease DraI detected 6 distinguished patterns among the 9 phages. Phage treatment prevented the growth of SPB for up to 10 h with multiplicity of infection ratios of 1, 10, 100, and 1000 in tryptic soy broth at 30 °C, and extended the lag phase of SPB growth for 2 h at 22 °C with multiplicities of infection of 10, 100, and 1000. These results suggest that the selected bacteriophage cocktail has a high potential for phage application to control SPB in raw animal materials destined for the rendering process.

scholarly journals Isolation and Characterization of an Arterivirus Defective Interfering RNA Genome

2000 ◽  
Vol 74 (7) ◽  
pp. 3156-3165 ◽  
Author(s):  
Richard Molenkamp ◽  
Babette C. D. Rozier ◽  
Sophie Greve ◽  
Willy J. M. Spaan ◽  
Eric J. Snijder
Keyword(s):  
Rna Virus ◽  
Equine Arteritis Virus ◽  
Reading Frame ◽  
Isolation And Characterization ◽  
The Family ◽  
Defective Interfering Rna ◽  
Rna Genome ◽  
Interfering Rna ◽  
Discontinuous Transcription

ABSTRACT Equine arteritis virus (EAV), the type member of the family Arteriviridae, is a single-stranded RNA virus with a positive-stranded genome of approximately 13 kb. EAV uses a discontinuous transcription mechanism to produce a nested set of six subgenomic mRNAs from which its structural genes are expressed. We have generated the first documented arterivirus defective interfering (DI) RNAs by serial undiluted passaging of a wild-type EAV stock in BHK-21 cells. A cDNA copy of the smallest DI RNA (5.6 kb) was cloned. Upon transfection into EAV-infected BHK-21 cells, transcripts derived from this clone (pEDI) were replicated and packaged. Sequencing of pEDI revealed that the DI RNA was composed of three segments of the EAV genome (nucleotides 1 to 1057, 1388 to 1684, and 8530 to 12704) which were fused in frame with respect to the replicase reading frame. Remarkably, this DI RNA has retained all of the sequences encoding the structural proteins. By insertion of the chloramphenicol acetyltransferase reporter gene in the DI RNA genome, we were able to delimitate the sequences required for replication/DI-based transcription and packaging of EAV DI RNAs and to reduce the maximal size of a replication-competent EAV DI RNA to approximately 3 kb.

scholarly journals New Member of the V1V2-Directed CAP256-VRC26 Lineage That Shows Increased Breadth and Exceptional Potency

2015 ◽  
Vol 90 (1) ◽  
pp. 76-91 ◽  
Author(s):  
Nicole A. Doria-Rose ◽  
Jinal N. Bhiman ◽  
Ryan S. Roark ◽  
Chaim A. Schramm ◽  
Jason Gorman ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Broadly Neutralizing Antibodies ◽  
New Members ◽  
Isolation And Characterization ◽  
The Family ◽  
Clade C ◽  
Potential Clinical Utility ◽  
Hiv 1 ◽  
Viral Isolates

ABSTRACT The epitopes defined by HIV-1 broadly neutralizing antibodies (bNAbs) are valuable templates for vaccine design, and studies of the immunological development of these antibodies are providing insights for vaccination strategies. In addition, the most potent and broadly reactive of these bNAbs have potential for clinical use. We previously described a family of 12 V1V2-directed neutralizing antibodies, CAP256-VRC26, isolated from an HIV-1 clade C-infected donor at years 1, 2, and 4 of infection (N. A. Doria-Rose et al., Nature 509:55–62, 2014, http://dx.doi.org/10.1038/nature13036 ). Here, we report on the isolation and characterization of new members of the family mostly obtained at time points of peak serum neutralization breadth and potency. Thirteen antibodies were isolated from B cell culture, and eight were isolated using trimeric envelope probes for differential single B cell sorting. One of the new antibodies displayed a 10-fold greater neutralization potency than previously published lineage members. This antibody, CAP256-VRC26.25, neutralized 57% of diverse clade viral isolates and 70% of clade C isolates with remarkable potency. Among the viruses neutralized, the median 50% inhibitory concentration was 0.001 μg/ml. All 33 lineage members targeted a quaternary epitope focused on V2. While all known bNAbs targeting the V1V2 region interact with the N160 glycan, the CAP256-VRC26 antibodies showed an inverse correlation of neutralization potency with dependence on this glycan. Overall, our results highlight the ongoing evolution within a single antibody lineage and describe more potent and broadly neutralizing members with potential clinical utility, particularly in areas where clade C is prevalent. IMPORTANCE Studies of HIV-1 broadly neutralizing antibodies (bNAbs) provide valuable information for vaccine design, and the most potent and broadly reactive of these bNAbs have potential for clinical use. We previously described a family of V1V2-directed neutralizing antibodies from an HIV-1 clade C-infected donor. Here, we report on the isolation and characterization of new members of the family mostly obtained at time points of peak serum neutralization breadth and potency. One of the new antibodies, CAP256-VRC26.25, displayed a 10-fold greater neutralization potency than previously described lineage members. It neutralized 57% of diverse clade viral isolates and 70% of clade C isolates with remarkable potency: the median 50% inhibitory concentration was 0.001 μg/ml. Our results highlight the ongoing evolution within a single antibody lineage and describe more potent and broadly neutralizing members with potential clinical utility, particularly in areas where clade C is prevalent.

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