scholarly journals TRANSFORMASI PLASMID YANG MENGANDUNG GEN merB PADA BAKTERI Escherichia coli TOP-10

PHARMACON ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 290
Author(s):  
Sarah Rotinsulu ◽  
Fatimawali Fatimawali ◽  
Trina E. Tallei

ABSTRACT DNA transformation is the process of inserting recombinant DNA into host cells via vector plasmid. The host cell that is often used is TOP-10 Escherichia coli. The transformation method is widely used to transfer plasmids containing genetic material. This study aimed to evaluate the results of plasmid transformation containing the merB gene in the Escherichia coli TOP-10 bacteria. This study initiated with identification of the microbiology of host cells to be used, namely Escherichia coli TOP-10. Escherichia coli TOP-10 host cells were made into competent cells by transforming plasmids containing merB gene into Escherichia coli TOP-10 host cells using the heat shock method. The transformation results were evaluated by observing at the growth of Escherichia coli TOP-10 colonies on agar LB media containing ampicillin antibiotics. Plasmids on Escherichia coli TOP-10 were isolated and analyzed by 1% agarose gel electrophoresis. The results showed that the transformation of plasmids containing merB in Escherichia coli TOP-10 bacteria was successfully carried out as indicated by the growth of Escherichia coli TOP-10 bacteria on LB media agar containing ampicillin and the visualization on agarose gel resulted that the plasmid which carried the merB gene could be transformed in to the E. coli TOP-10 bacteria cell. Keywords: Transformation, Plasmids, merB genes, heat shocks, E. coli TOP-10ABSTRAK Transformasi DNA merupakan proses memasukkan DNA kedalam sel bakteri. Metode transformasi dipakai secara luas untuk mantransfer plasmid yang mengandung bahan genetika. Penelitian ini bertujuan untuk mengevaluasi hasil transformasi plasmid yang mengandung gen merB pada bakteri Escherichia coli TOP-10. Penelitian ini didahului dengan identifikasi secara mikrobiologi bakteri Escherichia coli TOP-10. Bakteri Escherichia coli TOP-10 dibuat menjadi sel kompeten yang digunakan sebagai inang. Selanjutnya dilakukan transformasi plasmid yang mengandung gen merB kedalam sel inang E. coli TOP-10 menggunakan metode heatshock. Hasil transformasi dievaluasi dengan melihat adanya koloni E. coli TOP-10 pada media LB agar yang mengandung antibiotik ampisilin. Plasmid pada E. coli TOP-10 diisolasi dan dianalisis dengan elektroforesis gel  agarose 1%. Hasil penelitian menunjukkan bahwa transformasi plasmid yang mengandung gen merB pada bakteri Escherichia coli TOP-10 berhasil dilakukan, ditunjukkan dengan adanya pertumbuhan bakteri E. coli TOP-10 pada media LB agar yang mengangandung ampisilin dan hasil visualisasi pada agarose gel terlihat bahwa plasmid yang membawa gen merB dapat ditransformasikan ke dalam sel bakteri E. coli TOP-10. Kata kunci : Transformasi, Plasmid, gen merB, heatshock, E. coli TOP-10 

PHARMACON ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 196
Author(s):  
Zefanya G Bernadus ◽  
Fatimawali Fatimawali ◽  
Beivy Kolondam

ABSTRACTDNA transformation is one of the methods for inserting DNA into bacterial cells. The current transformation method is widely used to transfer plasmids containing genetic material. This study aims to evaluate the results of plasmid transformation containing merB gene in Escherichia coli BL21(DE3) bacteria. The stages of the research carried out were preceded by the microbiological identification of the E. coli BL21(DE3) bacteria used as hosts. Then the plasmid transformation containing merB gene into the E. coli BL21(DE3) host cell using the heat shock method was carried out. The transformation results were evaluated by observing at the presence of E. coli BL21(DE3) colonies on agar Luria Bertani (LB) media containing ampicillin antibiotics. Plasmids in E. coli BL21(DE3) were isolated and analyzed by 1% agarose gel electrophoresis. The results showed the success of the transformation indicated by the growth of E. coli BL21(DE3) bacteria in agar LB media containing ampicillin and the visualization on agarose gel resulted that the plasmid which carried the merB gene could be transformed in to the E. coli BL21(DE3) bacteria.Keywords : Plasmids, merB genes, heat shock, Escherichia coli BL21(DE3)ABSTRAKTransformasi DNA merupakan salah satu metode untuk memasukkan DNA ke dalam sel bakteri. Metode transformasi saat ini dipakai secara luas untuk mentransfer plasmid yang mengandung bahan genetika. Penelitian ini bertujuan untuk mengevaluasi hasil transformasi plasmid yang mengandung gen merB pada bakteri Escherichia coli BL21(DE3). Tahapan penelitian didahului dengan identifikasi secara mikrobiologi bakteri E. coli BL21(DE3) yang digunakan sebagai inang. Selanjutnya dilakukan transformasi plasmid yang mengandung gen merB kedalam sel inang E. coli BL21(DE3) menggunakan metode heat shock. Hasil transformasi dievaluasi dengan melihat adanya koloni E. coli BL21(DE3) pada media agar Luria Bertani (LB) yang mengandung antibiotik ampisilin. Plasmid pada E. coli BL21(DE3) diisolasi dan dianalisis dengan elektroforesis gel agarose 1%. Hasil penelitian menunjukkan keberhasilan transformasi dengan adanya pertumbuhan bakteri E. coli BL21(DE3) pada media LB yang mengandung ampisillin dan hasil visualisasi pada agarose gel terlihat bahwa plasmid yang membawa gen merB dapat ditransformasikan ke dalam bakteri E. coli BL21(DE3).Kata Kunci : Plasmid, gen merB, heat shock, Escherichia coli BL21(DE3)


1998 ◽  
Vol 64 (12) ◽  
pp. 4862-4869 ◽  
Author(s):  
Jörg F. Rippmann ◽  
Michaela Klein ◽  
Christian Hoischen ◽  
Bodo Brocks ◽  
Wolfgang J. Rettig ◽  
...  

ABSTRACT Recently it has been demonstrated that L-form cells ofProteus mirabilis (L VI), which lack a periplasmic compartment, can be efficiently used in the production and secretion of heterologous proteins. In search of novel expression systems for recombinant antibodies, we compared levels of single-chain variable-fragment (scFv) production in Escherichia coliJM109 and P. mirabilis L VI, which express four distinct scFvs of potential clinical interest that show differences in levels of expression and in their tendencies to form aggregates upon periplasmic expression. Production of all analyzed scFvs in E. coli was limited by the severe toxic effect of the heterologous product as indicated by inhibition of culture growth and the formation of insoluble aggregates in the periplasmic space, limiting the yield of active product. In contrast, the L-form cells exhibited nearly unlimited growth under the tested production conditions for all scFvs examined. Moreover, expression experiments with P. mirabilis L VI led to scFv concentrations in the range of 40 to 200 mg per liter of culture medium (corresponding to volume yields 33- to 160-fold higher than those with E. coli JM109), depending on the expressed antibody. In a translocation inhibition experiment the secretion of the scFv constructs was shown to be an active transport coupled to the signal cleavage. We suppose that this direct release of the newly synthesized product into a large volume of the growth medium favors folding into the native active structure. The limited aggregation of scFv observed in the P. mirabilis L VI supernatant (occurring in a first-order-kinetics manner) was found to be due to intrinsic features of the scFv and not related to the expression process of the host cells. The P. mirabilis L VI supernatant was found to be advantageous for scFv purification. A two-step chromatography procedure led to homogeneous scFv with high antigen binding activity as revealed from binding experiments with eukaryotic cells.


2020 ◽  
Vol 44 (1) ◽  
Author(s):  
E. L. Mejía-Argueta ◽  
J. G. Santillán-Benítez ◽  
M. M. Canales-Martinez ◽  
A. Mendoza-Medellín

Abstract Background To test the antimicrobial potential of clove essential oil that has been less investigated on antimicrobial-resistant organisms (extended-spectrum β-lactamase-ESBL-producing Escherichia coli), we collected 135 ESBL-producing Escherichia coli strains given that E. coli is the major organism increasingly isolated as a cause of complicated urinary and gastrointestinal tract infections, which remains an important cause of therapy failure with antibiotics for the medical sector. Then, in this study, we evaluated the relationship between the antibacterial potential activity of Syzygium aromaticum essential oil (EOSA) and the expression of antibiotic-resistant genes (SHV-2, TEM-20) in plasmidic DNA on ESBL-producing E. coli using RT-PCR technique. Results EOSA was obtained by hydrodistillation. Using Kirby-Baüer method, we found that EOSA presented a smaller media (mean = 15.59 mm) in comparison with chloramphenicol (mean = 17.73 mm). Thus, there were significant differences (p < 0.0001). Furthermore, EOSA had an antibacterial activity, particularly on ECB132 (MIC: 10.0 mg/mL and MBC: 80.0 mg/mL), and a bacteriostatic effect by bactericidal kinetic. We found that the expression of antibiotic-resistant gene blaTEM-20 was 23.52% (4/17 strains) and no expression of blaSHV-2. EOSA presented such as majority compounds (eugenol, caryophyllene) using the GC–MS technique. Conclusions Plant essential oils and their active ingredients have potentially high bioactivity against a different target (membranes, cytoplasm, genetic material). In this research, EOSA might become an important adjuvant against urinary and gastrointestinal diseases caused by ESBL-producing E. coli.


Genetics ◽  
1990 ◽  
Vol 125 (4) ◽  
pp. 691-702 ◽  
Author(s):  
B L Berg ◽  
V Stewart

Abstract Formate oxidation coupled to nitrate reduction constitutes a major anaerobic respiratory pathway in Escherichia coli. This respiratory chain consists of formate dehydrogenase-N, quinone, and nitrate reductase. We have isolated a recombinant DNA clone that likely contains the structural genes, fdnGHI, for the three subunits of formate dehydrogenase-N. The fdnGHI clone produced proteins of 110, 32 and 20 kDa which correspond to the subunit sizes of purified formate dehydrogenase-N. Our analysis indicates that fdnGHI is organized as an operon. We mapped the fdn operon to 32 min on the E. coli genetic map, close to the genes for cryptic nitrate reductase (encoded by the narZ operon). Expression of phi(fdnG-lacZ) operon fusions was induced by anaerobiosis and nitrate. This induction required fnr+ and narL+, two regulatory genes whose products are also required for the anaerobic, nitrate-inducible activation of the nitrate reductase structural gene operon, narGHJI. We conclude that regulation of fdnGHI and narGHJI expression is mediated through common pathways.


2010 ◽  
Vol 78 (9) ◽  
pp. 4068-4076 ◽  
Author(s):  
Jennifer Hwang ◽  
Lisa M. Mattei ◽  
Laura G. VanArendonk ◽  
Philip M. Meneely ◽  
Iruka N. Okeke

ABSTRACT Enteroaggregative Escherichia coli (EAEC) strains are important diarrheal pathogens. EAEC strains are defined by their characteristic stacked-brick pattern of adherence to epithelial cells but show heterogeneous virulence and have different combinations of adhesin and toxin genes. Pathoadaptive deletions in the lysine decarboxylase (cad) genes have been noted among hypervirulent E. coli subtypes of Shigella and enterohemorrhagic E. coli. To test the hypothesis that cad deletions might account for heterogeneity in EAEC virulence, we developed a Caenorhabditis elegans pathogenesis model. Well-characterized EAEC strains were shown to colonize and kill C. elegans, and differences in virulence could be measured quantitatively. Of 49 EAEC strains screened for lysine decarboxylase activity, 3 tested negative. Most notable is isolate 101-1, which was recovered in Japan, from the largest documented EAEC outbreak. EAEC strain 101-1 was unable to decarboxylate lysine in vitro due to deletions in cadA and cadC, which, respectively, encode lysine decarboxylase and a transcriptional activator of the cadAB genes. Strain 101-1 was significantly more lethal to C. elegans than control strain OP50. Lethality was attenuated when the lysine decarboxylase defect was complemented from a multicopy plasmid and in single copy. In addition, restoring lysine decarboxylase function produced derivatives of 101-1 deficient in aggregative adherence to cultured human epithelial cells. Lysine decarboxylase inactivation is pathoadapative in an important EAEC outbreak strain, and deletion of cad genes could produce hypervirulent EAEC lineages in the future. These results suggest that loss, as well as gain, of genetic material can account for heterogeneous virulence among EAEC strains.


2011 ◽  
Vol 80 (2) ◽  
pp. 493-505 ◽  
Author(s):  
Patrick D. Vigil ◽  
Travis J. Wiles ◽  
Michael D. Engstrom ◽  
Lev Prasov ◽  
Matthew A. Mulvey ◽  
...  

ABSTRACTUropathogenicEscherichia coli(UPEC) is responsible for the majority of uncomplicated urinary tract infections (UTI) and represents the most common bacterial infection in adults. UPEC utilizes a wide range of virulence factors to colonize the host, including the novel repeat-in-toxin (RTX) protein TosA, which is specifically expressed in the host urinary tract and contributes significantly to the virulence and survival of UPEC.tosA, found in strains within the B2 phylogenetic subgroup ofE. coli, serves as a marker for strains that also contain a large number of well-characterized UPEC virulence factors. The presence oftosAin anE. coliisolate predicts successful colonization of the murine model of ascending UTI, regardless of the source of the isolate. Here, a detailed analysis of the function oftosArevealed that this gene is transcriptionally linked to genes encoding a conserved type 1 secretion system similar to other RTX family members. TosA localized to the cell surface and was found to mediate (i) adherence to host cells derived from the upper urinary tract and (ii) survival in disseminated infections and (iii) to enhance lethality during sepsis (as assessed in two different animal models of infection). An experimental vaccine, using purified TosA, protected vaccinated animals against urosepsis. From this work, it was concluded that TosA belongs to a novel group of RTX proteins that mediate adherence and host damage during UTI and urosepsis and could be a novel target for the development of therapeutics to treat ascending UTIs.


2018 ◽  
Vol 86 (4) ◽  
Author(s):  
Maarten F. de Jong ◽  
Neal M. Alto

ABSTRACT The enteric attaching and effacing (A/E) pathogens enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC) and the invasive pathogens enteroinvasive E. coli (EIEC) and Shigella encode type III secretion systems (T3SS) used to inject effector proteins into human host cells during infection. Among these are a group of effectors required for NF-κB-mediated host immune evasion. Recent studies have identified several effector proteins from A/E pathogens and EIEC/ Shigella that are involved in suppression of NF-κB and have uncovered their cellular and molecular functions. A novel mechanism among these effectors from both groups of pathogens is to coordinate effector function during infection. This cooperativity among effector proteins explains how bacterial pathogens are able to effectively suppress innate immune defense mechanisms in response to diverse classes of immune receptor signaling complexes (RSCs) stimulated during infection.


1986 ◽  
Vol 69 (3) ◽  
pp. 531-536
Author(s):  
Walter E Hill ◽  
Barry A Wentz ◽  
William L Payne ◽  
James A Jagow ◽  
Gerald Zon ◽  
...  

Abstract The genes that encode several of the enterotoxins produced by Escherichia coli have been cloned by recombinant DNA techniques. When the nucleotide sequence of these genes is determined, defined sequence oligonucleotides that include a part of these genes may be synthesized. A 22-base DNA hybridization probe was produced for each of 2 heatstable E. coli enterotoxin (ST) genes: STH, from strains originally isolated from humans; and STP, from strains first found in pigs. For this study, 32P end-labeled DNA probes, sonicated calf thymus DNA, and 3 known and 20 unknown (10 ST-positive and 10 ST-negative) strains were sent to each of 23 collaborators. Cultures were spotted onto an agar-based medium and grown into colonies, which were transferred by blotting to cellulose filters, lysed by alkali and steam, and used for DNA colony hybridization with the ST DNA probes. Strains containing an ST gene were recognized as dark spots on an autoradiogram. Of the 460 samples analyzed, 440 (95.7%) were correctly classified by the collaborators. The method has been adopted official first action.


2019 ◽  
Vol 87 (10) ◽  
Author(s):  
Tracy H. Hazen ◽  
David A. Rasko

ABSTRACT Enteropathogenic Escherichia coli (EPEC) is a leading cause of moderate to severe diarrhea among young children in developing countries, and EPEC isolates can be subdivided into two groups. Typical EPEC (tEPEC) bacteria are characterized by the presence of both the locus of enterocyte effacement (LEE) and the plasmid-encoded bundle-forming pilus (BFP), which are involved in adherence and translocation of type III effectors into the host cells. Atypical EPEC (aEPEC) bacteria also contain the LEE but lack the BFP. In the current report, we describe the complete genome of outbreak-associated aEPEC isolate E110019, which carries four plasmids. Comparative genomic analysis demonstrated that the type III secreted effector EspT gene, an autotransporter gene, a hemolysin gene, and putative fimbrial genes are all carried on plasmids. Further investigation of 65 espT-containing E. coli genomes demonstrated that different espT alleles are associated with multiple plasmids that differ in their overall gene content from the E110019 espT-containing plasmid. EspT has been previously described with respect to its role in the ability of E110019 to invade host cells. While other type III secreted effectors of E. coli have been identified on insertion elements and prophages of the chromosome, we demonstrated in the current study that the espT gene is located on multiple unique plasmids. These findings highlight a role of plasmids in dissemination of a unique E. coli type III secreted effector that is involved in host invasion and severe diarrheal illness.


2020 ◽  
Vol 8 (2) ◽  
pp. 201
Author(s):  
Anja Klančnik ◽  
Ivana Gobin ◽  
Barbara Jeršek ◽  
Sonja Smole Možina ◽  
Darinka Vučković ◽  
...  

The aim of this study was to evaluate Campylobacter jejuni NTCT 11168 adhesion to abiotic and biotic surfaces when grown in co-culture with Escherichia coli ATCC 11229 and/or Listeria monocytogenes 4b. Adhesion of C. jejuni to polystyrene and to Caco-2 cells and Acanthamoeba castellanii was lower for at least 3 log CFU/mL compared to E. coli and L. monocytogenes. Electron micrographs of ultrathin sections revealed interactions of C. jejuni with host cells. In co-culture with E. coli and L. monocytogenes, adhesion of C. jejuni to all tested surfaces was significantly increased for more than 1 log CFU/mL. There was 10% higher aggregation for C. jejuni than for other pathogens, and high co-aggregation of co-cultures of C. jejuni with E. coli and L. monocytogenes. These data show that C. jejuni in co-cultures with E. coli and L. monocytogenes present significantly higher risk than C. jejuni as mono-cultures, which need to be taken into account in risk evaluation. C. jejuni adhesion is a prerequisite for their colonization, biofilm formation, and further contamination of the environment. C. jejuni survival under adverse conditions as a factor in their pathogenicity and depends on their adhesion to different surfaces, not only as individual strains, but also in co-cultures with other bacteria like E. coli and L. monocytogenes.


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