scholarly journals Relation of the pdxB-usg-truA-dedA Operon and the truA Gene to the Intracellular Survival of Salmonella enterica Serovar Typhimurium

2019 ◽  
Vol 20 (2) ◽  
pp. 380 ◽  
Author(s):  
Xiaowen Yang ◽  
Jiawei Wang ◽  
Ziyan Feng ◽  
Xiangjian Zhang ◽  
Xiangguo Wang ◽  
...  

Salmonella is the genus of Gram-negative, facultative intracellular pathogens that have the ability to infect large numbers of animal or human hosts. The S. enterica usg gene is associated with intracellular survival based on ortholog screening and identification. In this study, the λ-Red recombination system was used to construct gene deletion strains and to investigate whether the identified operon was related to intracellular survival. The pdxB-usg-truA-dedA operon enhanced the intracellular survival of S. enterica by resisting the oxidative environment and the usg and truA gene expression was induced by H2O2. Moreover, the genes in this operon (except for dedA) contributed to virulence in mice. These findings indicate that the pdxB-usg-truA-dedA operon functions in resistance to oxidative environments during intracellular survival and is required for in vivo S. enterica virulence. This study provides insight toward a better understand of the characteristics of intracellular pathogens and explores the gene modules involved in their intracellular survival.

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Nicholas M. Thomson ◽  
Chuanzhen Zhang ◽  
Eleftheria Trampari ◽  
Mark J. Pallen

Abstract Background Gene doctoring is an efficient recombination-based genetic engineering approach to mutagenesis of the bacterial chromosome that combines the λ-Red recombination system with a suicide donor plasmid that is cleaved in vivo to generate linear DNA fragments suitable for recombination. The use of a suicide donor plasmid makes Gene Doctoring more efficient than other recombineering technologies. However, generation of donor plasmids typically requires multiple cloning and screening steps. Results We constructed a simplified acceptor plasmid, called pDOC-GG, for the assembly of multiple DNA fragments precisely and simultaneously to form a donor plasmid using Golden Gate assembly. Successful constructs can easily be identified through blue-white screening. We demonstrated proof of principle by inserting a gene for green fluorescent protein into the chromosome of Escherichia coli. We also provided related genetic parts to assist in the construction of mutagenesis cassettes with a tetracycline-selectable marker. Conclusions Our plasmid greatly simplifies the construction of Gene Doctoring donor plasmids and allows for the assembly of complex, multi-part insertion or deletion cassettes with a free choice of target sites and selection markers. The tools we developed are applicable to gene editing for a wide variety of purposes in Enterobacteriaceae and potentially in other diverse bacterial families.


2005 ◽  
Vol 73 (12) ◽  
pp. 8433-8436 ◽  
Author(s):  
A. A. Fadl ◽  
J. Sha ◽  
G. R. Klimpel ◽  
J. P. Olano ◽  
C. L. Galindo ◽  
...  

ABSTRACT We constructed Salmonella enterica serovar Typhimurium double-knockout mutants in which either the lipoprotein A (lppA) or the lipoprotein B (lppB) gene was deleted from an msbB-negative background strain by marker exchange mutagenesis. These mutants were highly attenuated when tested with in vitro and in vivo models of Salmonella pathogenesis.


Microbiology ◽  
2009 ◽  
Vol 155 (10) ◽  
pp. 3403-3410 ◽  
Author(s):  
G. K. Paterson ◽  
D. B. Cone ◽  
S. E. Peters ◽  
D. J. Maskell

The enzyme phosphoglucomutase (Pgm) catalyses the interconversion of glucose 1-phosphate and glucose 6-phosphate and contributes to glycolysis and the generation of sugar nucleotides for biosynthesis. To assess the role of this enzyme in the biology of the pathogen Salmonella enterica serovar Typhimurium we have characterized a pgm deletion mutant in strain SL1344. Compared to SL1344, SL1344 pgm had impaired growth in vitro, was deficient in the ability to utilize galactose as a carbon source and displayed reduced O-antigen polymer length. The mutant was also more susceptible to antimicrobial peptides and showed decreased fitness in the mouse typhoid model. The in vivo phenotype of SL1344 pgm indicated a role for pgm in the early stages of infection, most likely through deficient O-antigen production. Although pgm mutants in other pathogens have potential as live attenuated vaccine strains, SL1344 pgm was not sufficiently attenuated for such use.


2003 ◽  
Vol 185 (1) ◽  
pp. 98-106 ◽  
Author(s):  
Elizabeth Skovran ◽  
Diana M. Downs

ABSTRACT The isc genes function in the assembly of Fe-S clusters and are conserved in many prokaryotic and eukaryotic organisms. In most bacteria studied, the isc operon can be deleted without loss of cell viability, indicating that additional systems for Fe-S cluster assembly must exist. Several laboratories have described nutritional and biochemical defects resulting from mutations in the isc operon. Here we demonstrate that null mutations in two genes of unknown function, apbC and apbE, result in similar cellular deficiencies. Exogenous ferric chloride suppressed these deficiencies in the apbC and apbE mutants, distinguishing them from previously described isc mutants. The deficiencies caused by the apbC and isc mutations were additive, which is consistent with Isc and ApbC's having redundant functions or with Isc and ApbC's functioning in different areas of Fe-S cluster metabolism (e.g., Fe-S cluster assembly and Fe-S cluster repair). Both the ApbC and ApbE proteins are similar in sequence to proteins that function in metal cofactor assembly. Like the enzymes with sequence similarity to ApbC, purified ApbC protein was able to hydrolyze ATP. The data herein are consistent with the hypothesis that the ApbC and ApbE proteins function in Fe-S cluster metabolism in vivo.


2018 ◽  
Vol 9 (2) ◽  
pp. 192
Author(s):  
Cristiane Santos Silva e Silva Figueiredo ◽  
Patrícia Viera de Oliveira ◽  
Warlison Felipe De Silva Saminez ◽  
Roseana Muniz Diniz ◽  
João Francisco Silva Rodrigues ◽  
...  

Introdução: Cinamaldeído (CND) é o principal componente ativo do óleo essencial da canela (Cinnamomum sp) e tem sido amplamente utilizado em atividades biológicas e farmacológicas, tendo sido relatado atividade antimicrobiana, antioxidante, antidiabética, dentre outras. Objetivo: Devido os diversos relatos das propriedades farmacológicas do composto, esse foi escolhido para revisão de literatura. A seleção da bibliografia foi obtida a partir de bases de dados (google scholar, NCBI - National Center for Biotechnology Information, PubMed e Scielo - Scientific Electronic Library Online). Discussão: A composição química do CND tem compostos terpenóides que têm poderosa atividade antimicrobiana contra fungos, bactérias Gram-positivas e Gram-negativas tais como Aeromonas hydrophila, Enterococcus faecalis, Clostridium botulinum, Staphylococcus aureus, Escherichia coli O157: H7 e Salmonella enterica serovar Typhimurium. A atividade anti-inflamatória induz a apoptose e inibi a proliferação celular, nas respostas imunes mediadas por monócitos/macrófagos, além de diminuir a produção de óxido nítrico induzido por lipopolissacáridos de um modo dependente da dose. CND ao ser administrado por via oral em ratos diabéticos demonstrou melhora no conteúdo de glicogênio muscular e hepático aumentando a liberação de insulina. Além disso CND estimulou a angiogênese in vivo e in vitro, regulando positivamente o fator de crescimento endotelial vascular. Conclusão: A partir do que foi relatado constatou-se que o CND possui muitas atividades com potencial farmacológico, mas percebe-se que se faz necessário estudos sobre o(s) mecanismos(s) de ação dessas atividades a fim de se proporcionar o uso seguro e eficaz do cinamaldeído.


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