Isolation and characterization of a conditional replication mutant of the antibiotic resistance factor R1 affected in the gene of the replication protein RepA

1989 ◽  
Vol 217 (1) ◽  
pp. 111-117 ◽  
Author(s):  
Sagrario Ortega ◽  
Gertrudis de Torrontegui ◽  
Ramón Díaz
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Factor ◽  
Replication Protein ◽  
Isolation And Characterization

scholarly journals Isolation and characterization of bacteriophages that infect Citrobacter rodentium, a model pathogen for investigating human intestinal diseases

2018 ◽  
Author(s):  
Carolina M. Mizuno ◽  
Tiffany Luong ◽  
Robert Cedarstrom ◽  
Mart Krupovic ◽  
Laurent Debarbieux ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Phage Therapy ◽  
Limit Of Detection ◽  
Lytic Cycle ◽  
Citrobacter Rodentium ◽  
E Coli ◽  
Isolation And Characterization ◽  
A New Species

AbstractEnteropathogenic Escherichia coli (EPEC) is a major etiology for diarrheal diseases among children. Antibiotics, when used appropriately, are effective; however, their overuse and misuse has led to the rise of antibiotic resistance worldwide. Thus, there are renewed efforts into the development of phage therapy. Due to the drawbacks of EPEC in vivo models, a surrogate is the mouse-restricted gut pathgoen Citrobacter rodentium. In this study, two new phages CrRp3 and CrRp10, which infect C. rodentium, were isolated and characterized. CrRp3 was found to be a new species within the genus Vectrevirus and CrRp10 is a new strain within the genus Tequatrovirus. Neither phage carries known genes associated with bacterial virulence, antibiotic resistance, or lysogeny. CrRp3 and CrRp10 appear to have independently evolved from E. coli phages. CrRp3 appears to be the more ‘potent’ being 24x more likely to find a host cell and has a shorter lytic cycle, while CrRp10 at MOI 0.001 was able to maintain bacterial density below the limit of detection after 18 h. We found that hypoxia (5% O2 and 5% CO2) inhibited CrRp3 ability to reverse exponential bacterial growth. It is unclear whether the subtle characteristic differences between CrRp3 and CrRp10 will influence treatment efficacy in future phage therapy in vivo investigations.

Isolation and characterization of antibiotic-resistance plasmids in thermophilic bacilli

1985 ◽  
Vol 31 (4) ◽  
pp. 339-345 ◽  
Author(s):  
Takayuki Hoshino ◽  
Takayuki Ikeda ◽  
Hiroyuki Narushima ◽  
Noboru Tomizuka
Keyword(s):  
Antibiotic Resistance ◽  
Southern Hybridization ◽  
Tetracycline Resistance ◽  
Restriction Endonuclease Analysis ◽  
Kanamycin Resistance ◽  
Isolation And Characterization ◽  
Thermophilic Bacilli ◽  
Resistance Plasmids ◽  
Endonuclease Analysis

Four antibiotic-resistance plasmids isolated from thermophilic bacilli were characterized in detail. Three tetracycline-resistance (Tcr) plasmids were designated as pTHT9 (7.7 kilobases (kb)), pTHT15 (4.5 kb) and pTHT22 (8.4 kb). From the results of restriction endonuclease analysis and the subsequent Southern hybridization, these were found to possess extensive genetic homology in the regions that include the replication origin and the Tcr gene. Detailed restriction maps of the smallest Tcr plasmid pTHT15 and a kanamycin-resistance (Kmr) plasmid pTHN1 (4.8 kb) were constructed. The positions of antibiotic-resistance loci and regions essential for plasmid replication were determined by cloning plasmid fragments in Bacillus subtilis. These four plasmids were found to replicate and express the resistance genes stably in both B. subtilis and B. stearothermophilus.

scholarly journals Bacteroides fragilis Transfer Factor Tn5520: the Smallest Bacterial Mobilizable Transposon Containing Single Integrase and Mobilization Genes That Function inEscherichia coli

1999 ◽  
Vol 181 (8) ◽  
pp. 2564-2571 ◽  
Author(s):  
Gayatri Vedantam ◽  
Thomas J. Novicki ◽  
David W. Hecht
Keyword(s):  
Antibiotic Resistance ◽  
Sequence Similarity ◽  
Shuttle Vector ◽  
Insertion Site ◽  
Bacteroides Fragilis ◽  
Open Reading Frames ◽  
Transfer Factors ◽  
E Coli ◽  
Isolation And Characterization

ABSTRACT Many bacterial genera, including Bacteroides spp., harbor mobilizable transposons, a class of transfer factors that carry genes for conjugal DNA transfer and, in some cases, antibiotic resistance. Mobilizable transposons are capable of inserting into and mobilizing other, nontransferable plasmids and are implicated in the dissemination of antibiotic resistance. This paper presents the isolation and characterization of Tn5520, a new mobilizable transposon from Bacteroides fragilis LV23. At 4,692 bp, it is the smallest mobilizable transposon reported from any bacterial genus. Tn5520 was captured from B. fragilis LV23 by using the transfer-deficient shuttle vector pGAT400ΔBglII. The termini of Tn5520 contain a 22-bp imperfect inverted repeat, and transposition does not result in a target site repeat. Tn5520 also demonstrates insertion site sequence preferences characterized by A-T-rich nucleotide sequences. Tn5520 has been sequenced in its entirety, and two large open reading frames whose predicted protein products exhibit strong sequence similarity to recombinase-integrase enzymes and mobilization proteins, respectively, have been identified. The transfer, mobilization, and transposition properties of Tn5520 have been studied, revealing that Tn5520mobilizes plasmids in both B. fragilis andEscherichia coli at high frequency and also transposes inE. coli.

scholarly journals Characterization of Acinetobacter spp. from raw goat Milk

2019 ◽  
Vol 49 (10) ◽  
Author(s):  
Gustavo Luis de Paiva Anciens Ramos ◽  
Janaína dos Santos Nascimento
Keyword(s):  
Antibiotic Resistance ◽  
Lipolytic Activity ◽  
Antibiotic Resistance Genes ◽  
Goat Milk ◽  
Isolation And Characterization ◽  
Goat’S Milk ◽  
Acinetobacter Spp ◽  
Goat's Milk

ABSTRACT: Goat’s milk has been suggested as an alternative to cow’s milk, being a better digestible and hypoallergenic option. However, the presence of contaminating bacteria may significantly affect the safety of the product. In this research, we reported the isolation and characterization of Acinetobacter spp. isolates from raw goat milk samples purchased in the state of Rio de Janeiro, Brazil. Twenty-one samples were analyzed and ten isolates of Acinetobacter spp. were obtained. Six were identified as A. guillouiae, three as A. ursingii, and one as A. bereziniae. These isolates were characterized and eight showed proteolytic activity, seven showed lipolytic activity, and five isolates were able to produce both enzymes. None of the isolates was biofilm producer. However, when the production of antibiotic resistance enzymes KPC and ESBL were investigated, all isolates presented ESBL-positive phenotype, while eight (80%) were KPC-positive. This research, therefore, demonstrated that raw goat’s milk can also be a source of Acinetobacter spp., which can produce important thermostable deteriorating enzymes and may play a role of reservoirs of antibiotic resistance genes.

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