scholarly journals Genetic Manipulation of Chlamydia trachomatis: Chromosomal Deletions

2019 ◽  
pp. 151-164
Author(s):  
Katerina Wolf ◽  
Mostafa Rahnama ◽  
Kenneth A. Fields
Keyword(s):  
Chlamydia Trachomatis ◽  
Genetic Manipulation ◽  
Chromosomal Deletions

scholarly journals Development of a Plasmid Shuttle Vector System for Genetic Manipulation of Chlamydia psittaci

mSphere ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Kensuke Shima ◽  
Mary M. Weber ◽  
Christiane Schnee ◽  
Konrad Sachse ◽  
Nadja Käding ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Genetic Manipulation ◽  
Shuttle Vector ◽  
Chlamydia Psittaci ◽  
Zoonotic Transmission ◽  
Vector System ◽  
Multiple Cloning Site ◽  
Host Pathogen Interactions ◽  
Content Type ◽  
Host Pathogen

ABSTRACT The obligate intracellular bacterium Chlamydia psittaci is a known avian pathogen causing psittacosis in birds and is capable of zoonotic transmission. In human pulmonary infections, C. psittaci can cause pneumonia associated with significant mortality if inadequately diagnosed and treated. Although intracellular C. psittaci manipulates host cell organelles for its replication and survival, it has been difficult to demonstrate host-pathogen interactions in C. psittaci infection due to the lack of easy-to-handle genetic manipulation tools. Here, we show the genetic transformation of C. psittaci using a plasmid shuttle vector that contains a controllable gene induction system. The 7,553-bp plasmid p01DC12 was prepared from the nonavian C. psittaci strain 01DC12. We constructed the shuttle vector pCps-Tet-mCherry using the full sequence of p01DC12 and the 4,449-bp fragment of Chlamydia trachomatis shuttle vector pBOMB4-Tet-mCherry. pCps-Tet-mCherry includes genes encoding the green fluorescent protein (GFP), mCherry, and ampicillin resistance (AmpR). Target genes can be inserted at a multiple cloning site (MCS). Importantly, these genes can be regulated by a tetracycline-inducible (tet) promoter. Using the pCps-Tet-mCherry plasmid shuttle vector, we show the expression of GFP, as well as the induction of mCherry expression, in C. psittaci strain 02DC15, which belongs to the avian C. psittaci 6BC clade. Furthermore, we demonstrated that pCps-Tet-mCherry was stably retained in C. psittaci transformants. Thus, our C. psittaci plasmid shuttle vector system represents a novel targeted approach that enables the elucidation of host-pathogen interactions. IMPORTANCE Psittacosis, caused by avian C. psittaci, has a major economic impact in the poultry industry worldwide and represents a significant risk for zoonotic transmission to humans. In the past decade, the tools of genetic manipulation have been improved for chlamydial molecular studies. While several genetic tools have been mainly developed in Chlamydia trachomatis, a stable gene-inducible shuttle vector system has not to date been available for C. psittaci. In this study, we adapted a C. trachomatis plasmid shuttle vector system to C. psittaci. We constructed a C. psittaci plasmid backbone shuttle vector called pCps-Tet-mCherry. The construct expresses GFP in C. psittaci. Importantly, exogeneous genes can be inserted at an MCS and are regulated by a tet promoter. The application of the pCps-Tet-mCherry shuttle vector system enables a promising new approach to investigate unknown gene functions of this pathogen.

Metabolic engineering of CHO cells to prepare glycoproteins

2018 ◽  
Vol 2 (3) ◽  
pp. 433-442 ◽  
Author(s):  
Qiong Wang ◽  
Michael J. Betenbaugh
Keyword(s):  
Metabolic Engineering ◽  
Cho Cells ◽  
Genetic Manipulation ◽  
Chinese Hamster ◽  
Post Translational Modification ◽  
Effector Functions ◽  
Recombinant Glycoproteins ◽  
Production Platform ◽  
Chemical Inhibitors ◽  
Amino Acid Mutations

As a complex and common post-translational modification, N-linked glycosylation affects a recombinant glycoprotein's biological activity and efficacy. For example, the α1,6-fucosylation significantly affects antibody-dependent cellular cytotoxicity and α2,6-sialylation is critical for antibody anti-inflammatory activity. Terminal sialylation is important for a glycoprotein's circulatory half-life. Chinese hamster ovary (CHO) cells are currently the predominant recombinant protein production platform, and, in this review, the characteristics of CHO glycosylation are summarized. Moreover, recent and current metabolic engineering strategies for tailoring glycoprotein fucosylation and sialylation in CHO cells, intensely investigated in the past decades, are described. One approach for reducing α1,6-fucosylation is through inhibiting fucosyltransferase (FUT8) expression by knockdown and knockout methods. Another approach to modulate fucosylation is through inhibition of multiple genes in the fucosylation biosynthesis pathway or through chemical inhibitors. To modulate antibody sialylation of the fragment crystallizable region, expressions of sialyltransferase and galactotransferase individually or together with amino acid mutations can affect antibody glycoforms and further influence antibody effector functions. The inhibition of sialidase expression and chemical supplementations are also effective and complementary approaches to improve the sialylation levels on recombinant glycoproteins. The engineering of CHO cells or protein sequence to control glycoforms to produce more homogenous glycans is an emerging topic. For modulating the glycosylation metabolic pathways, the interplay of multiple glyco-gene knockouts and knockins and the combination of multiple approaches, including genetic manipulation, protein engineering and chemical supplementation, are detailed in order to achieve specific glycan profiles on recombinant glycoproteins for superior biological function and effectiveness.

Screening auf Chlamydia trachomatis Infektion in der Schwangerschaft

2008 ◽  
Vol 68 (S 01) ◽  
Author(s):  
TM Weissenbacher ◽  
A Gingelmaier ◽  
M Kupka ◽  
F Kainer ◽  
K Friese ◽  
...  
Keyword(s):  
Chlamydia Trachomatis

Drug-Induced Agranulocytosis: A Mini Review

2016 ◽  
Vol 2 (1) ◽  
pp. 57-59
Author(s):  
Pavithra D ◽  
Praveen D ◽  
Vijey Aanandhi M
Keyword(s):  
Bone Marrow ◽  
Complete Blood Count ◽  
Genetic Manipulation ◽  
White Blood Cells ◽  
Deep Infection ◽  
Morbidity Rate ◽  
Drug Induced ◽  
Serious Adverse Event ◽  
Mortality And Morbidity ◽  
The Individual

Agranulocytosis is also known to be granulopenia, causing neutropenia in circulating blood streams .The destruction of white blood cells takes place which leads to increase in the infection rate in an individual where immune system of the individual is suppressed. The symptoms includes fever, sore throat, mouth ulcers. These are commonly seen as adverse effects of a particular drug and are prescribed for the common diagnostic test for regular monitoring of complete blood count in an admitted patient. Drug-induced agranulocytosis remains a serious adverse event due to occurrence of severe sepsis with deep infection leading to pneumonia, septicaemia, and septic shock in two/third of the patient. Antibiotics seem to be the major causative weapon for this disorder. Certain drugs mainly anti-thyroid drugs, ticlopidine hydrochloride, spironolactone, clozapine, antileptic drugs (clozapine), non-steroidal anti-inflammatory agents, dipyrone are the potential causes. Bone marrow insufficiency followed by destruction or limited proliferative bone marrow destruction takes place. Chemotherapy is rarely seen as a causative agent for this disorder. Genetic manipulation may also include as one of the reason. Agranulocytosis can be recovered within two weeks but the mortality and morbidity rate during the acute phase seems to be high, appropriate adjuvant treatment with broad-spectrum antibiotics are prerequisites for the management of complicated neutropenia. Drugs that are treated for this are expected to change as a resistant drug to the patient. The pathogenesis of agranulocytosis is not yet known. A comprehensive literature search has been carried out in PubMed, Google Scholar and articles pertaining to drug-induced agranulocytosis were selected for review.

Udział atypowego patogenu Chlamydia trachomatis w zapaleniach cewki moczowej

2016 ◽  
Vol 7 (6) ◽  
pp. 425-428
Author(s):  
Magdalena Frej-Mądrzak ◽  
Jolanta Sarowska ◽  
Agnieszka Jama-Kmiecik ◽  
Dorota Teryks-Wołyniec ◽  
Irena Choroszy-Król
Keyword(s):  
Chlamydia Trachomatis

Improvement of effectiveness in maize breeding

2006 ◽  
Vol 54 (3) ◽  
pp. 351-358 ◽  
Author(s):  
P. Pepó
Keyword(s):  
Recurrent Selection ◽  
Genetic Manipulation ◽  
Field Testing ◽  
Tissue Cultures ◽  
Maize Breeding ◽  
Breeding Programmes ◽  
Speed Up ◽  
Selection For

Plant regeneration via tissue culture is becoming increasingly more common in monocots such as maize (Zea mays L.). Pollen (gametophytic) selection for resistance to aflatoxin in maize can greatly facilitate recurrent selection and the screening of germplasm for resistance at much less cost and in a shorter time than field testing. In vivo and in vitro techniques have been integrated in maize breeding programmes to obtain desirable agronomic attributes, enhance the genes responsible for them and speed up the breeding process. The efficiency of anther and tissue cultures in maize and wheat has reached the stage where they can be used in breeding programmes to some extent and many new cultivars produced by genetic manipulation have now reached the market.

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