scholarly journals Regulation of polyphosphate kinase gene expression in Acinetobacter baumannii 252

Microbiology ◽  
1999 ◽  
Vol 145 (10) ◽  
pp. 2931-2937 ◽  
Author(s):  
Julie-Ann Gavigan ◽  
Leonard M. Marshall ◽  
Alan D. W. Dobson
Author(s):  
Elham Abbasi ◽  
Hossein Goudarzi ◽  
Ali Hashemi ◽  
Alireza Salimi Chirani ◽  
Abdollah Ardebili ◽  
...  

AbstractA major challenge in the treatment of infections has been the rise of extensively drug resistance (XDR) and multidrug resistance (MDR) in Acinetobacter baumannii. The goals of this study were to determine the pattern of antimicrobial susceptibility, blaOXA and carO genes among burn-isolated A. baumannii strains. In this study, 100 A. baumannii strains were isolated from burn patients and their susceptibilities to different antibiotics were determined using disc diffusion testing and broth microdilution. Presence of carO gene and OXA-type carbapenemase genes was tested by PCR and sequencing. SDS-PAGE was done to survey CarO porin and the expression level of carO gene was evaluated by Real-Time PCR. A high rate of resistance to meropenem (98%), imipenem (98%) and doripenem (98%) was detected. All tested A. baumannii strains were susceptible to colistin. The results indicated that 84.9% were XDR and 97.9% of strains were MDR. In addition, all strains bore blaOXA-51 like and blaOXA-23 like and carO genes. Nonetheless, blaOXA-58 like and blaOXA-24 like genes were harbored by 0 percent and 76 percent of strains, respectively. The relative expression levels of the carO gene ranged from 0.06 to 35.01 fold lower than that of carbapenem-susceptible A. baumannii ATCC19606 and SDS – PAGE analysis of the outer membrane protein showed that all 100 isolates produced CarO. The results of current study revealed prevalence of blaOXA genes and changes in carO gene expression in carbapenem resistant A.baumannii.


Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 471
Author(s):  
Camila Pimentel ◽  
Casin Le ◽  
Marisel R. Tuttobene ◽  
Tomas Subils ◽  
Jasmine Martinez ◽  
...  

Acinetobacter baumannii is a nosocomial pathogen capable of causing serious infections associated with high rates of morbidity and mortality. Due to its antimicrobial drug resistance profile, A. baumannii is categorized as an urgent priority pathogen by the Centers for Disease Control and Prevention in the United States and a priority group 1 critical microorganism by the World Health Organization. Understanding how A. baumannii adapts to different host environments may provide critical insights into strategically targeting this pathogen with novel antimicrobial and biological therapeutics. Exposure to human fluids was previously shown to alter the gene expression profile of a highly drug-susceptible A. baumannii strain A118 leading to persistence and survival of this pathogen. Herein, we explore the impact of human pleural fluid (HPF) and human serum albumin (HSA) on the gene expression profile of a highly multi-drug-resistant strain of A. baumannii AB5075. Differential expression was observed for ~30 genes, whose products are involved in quorum sensing, quorum quenching, iron acquisition, fatty acid metabolism, biofilm formation, secretion systems, and type IV pilus formation. Phenotypic and further transcriptomic analysis using quantitative RT-PCR confirmed RNA-seq data and demonstrated a distinctive role of HSA as the molecule involved in A. baumannii’s response.


1983 ◽  
Vol 3 (4) ◽  
pp. 643-653
Author(s):  
G M Santangelo ◽  
C N Cole

Fragments of African green monkey (Cercopithecus aethiops) DNA (3.5 to 18.0 kilobases) were inserted downstream from the thymidine kinase (TK, tk) coding region in pTK206/SV010, a gene construct which lacks both copies of the hexanucleotide 5'-AATAAA-3' and contains a simian virus 40 origin of replication, allowing it to replicate in Cos-1 cells. No polyadenylated tk mRNA was detected in Cos-1 cells transfected by pTK206/SV010. The ability of simian DNA fragments to restore tk gene expression was examined by measuring the incorporation of [125I]iododeoxycytidine into DNA in Cos-1 cells transfected by pTK206/SV010 insertion derivatives. tk gene expression was restored by the insertion in 56 of the 67 plasmids analyzed, and the level of expression equaled or exceeded that obtained with the wild-type tk gene in 30 of these. In all plasmids examined that showed restoration of tk gene expression, polyadenylated tk mRNA of discrete size was detected. The sizes of these tk mRNAs were consistent with the existence of processing and polyadenylation signals within the inserted DNA fragments. The frequency with which inserted fragments restored tk gene expression suggests that the minimal signal for processing and polyadenylation is a hexanucleotide (AAUAAA or a similar sequence). LTK- cells were biochemically transformed to TK+ with representative insertion constructs. pTK206/SV010 transformed LTK- cells at a very low frequency; the frequency of transformation with insertion derivatives was 40 to 12,000 times higher.


2016 ◽  
Vol 60 (6) ◽  
pp. 3415-3418 ◽  
Author(s):  
Esther Zander ◽  
Harald Seifert ◽  
Paul G. Higgins

Different physiological conditions, such as NaCl, low pH, and sodium salicylate, have been shown to affect antibiotic resistance determinants inAcinetobacter baumanniiisolates. Therefore, the aim of this study was to investigate the effects of NaCl, sodium salicylate, and low pH on the susceptibility ofA. baumanniito carbapenem. We cloned genes encoding oxacillinases (OXA) of different subclasses, with their associated promoters, from carbapenem-resistantA. baumanniiisolates into the same vector and transferred them to theA. baumanniireference strains ATCC 19606 and ATCC 17978. Carbapenem MICs were determined at least in triplicate by agar dilution under standard conditions, as well as in the presence of 200 mM NaCl or 16 mM sodium salicylate, or at pH 5.8. OXA-58-like gene expression was determined by reverse transcription-quantitative PCR (qRT-PCR). Under some experimental conditions, significant MIC reductions were shown for some transformants but not for others. Only in one instance were all transformants harboring the same OXA affected by the same condition: at pH 5.8, the imipenem and meropenem MICs for strains expressing OXA-58-like enzymes decreased from a resistant level (32 to 64 mg/liter) to an intermediate-susceptible level (8 mg/liter). However,blaOXA-58-likegene expression remained the same. MICs for both wild-type reference strains were not affected by the conditions tested. Our results indicate that the effects of the experimental conditions tested on OXAin vivoare mostly strain dependent. MICs were not reduced to wild-type levels, suggesting that the conditions tested do not lead to complete OXA inhibition in the bacterial cell.


1986 ◽  
Vol 6 (6) ◽  
pp. 2262-2266 ◽  
Author(s):  
J A Lewis ◽  
D A Matkovich

We have constructed a chimeric thymidine kinase (TK) minigene, pHe delta 6Ha, which combines the complete coding and 3' noncoding regions of a Chinese hamster TK cDNA with the promoter region and 5' untranslated region of the TK gene of herpes simplex virus type 1. We have transformed rat 4 cells to Tk+ with this gene and analyzed the pattern of TK gene expression in these transformants under various conditions of in vitro cell culture. We find that TK gene expression in these Tk+ transformants is growth phase dependent, responsive to adenovirus 5 infection, and indistinguishable in character under a variety of cell culture conditions from the pattern of TK gene expression in rat 4 cells transformed to Tk+ with the genomic Chinese hamster TK gene clone lambda HaTK.5. We are led to the conclusion that the genetic elements which mediate growth phase-dependent TK gene expression are contained entirely within the sequences of the mature cytoplasmic hamster TK mRNA.


2018 ◽  
Vol 7 (4) ◽  
pp. 236
Author(s):  
Ramdan Panigoro ◽  
Fadhal M. Ahmad ◽  
Uni Gamayani ◽  
Neni Anggraeni ◽  
Rini Widyastuti ◽  
...  

Iron is essential and needed in a very small amount. When iron exceeds normal need, metabolic alteration occurs, causing hepatosteatosis. The mechanism of iron inducing hepatosteatosis remains unclear. Glycerol kinase, the enzyme responsible in triglyceride synthesis initiation, is assumed to have a role in the pathomechanism of hepatosteatosis. This study aimed to investigate the gene expression of glycerol kinase in an acute iron overload condition. This study was conducted in Animal Laboratory Faculty of Medicine and Central Laboratory Universitas Padjadjaran from May to June 2017. Three groups of mice were divided by the dose of iron dextran injection (0, 0.1, 0.3 mg/day/mice). After 19 days, mice were terminated, liver weight was measured and glycerol kinase gene expression in the liver was determined by semi-qualitative PCR. Quantification of PCR result was calculated by ImageJ software. There was a significant change in liver weight of the mice in a dose-dependent manner of iron injection. The expression of glycerol kinase tended to decrease, but statistically insignificant. Acute iron dextran injection increases liver weight and tends to reduce glycerol kinase gene expression in mice liver.Keywords: Glycerol kinase, hepatosteatosis, iron overload Efek Zat Besi Dosis Tinggi Akut dalam Meningkatkan Berat Organ dan Menurunkan Ekspresi Gliserol Kinase HeparAbstrakZat besi merupakan nutrien esensial dan diperlukan dalam jumlah yang sangat kecil. Ketika kadar zat besi melebihi kadar normal dalam tubuh, terjadi perubahan metabolisme yang menyebabkan hepatosteatosis. Mekanisme zat besi dalam menyebabkan hepatosteatosis masih belum diketahui secara pasti. Gliserol kinase, enzim yang menginisiasi sintesis trigliserida, diduga berperan dalam patomekanisme hepatosteatosis. Penelitian ini bertujuan untuk meneliti ekspresi gen gliserol kinase pada hepar pada kondisi tinggi zat besi akut. Penelitian ini dilakukan di Laboratorium Hewan Fakultas Kedokteran dan Laboratorium Sentral Universitas Padjadjaran dari bulan Mei sampai dengan Juni 2017. Tiga kelompok mencit dibagi berdasarkan dosis injeksi iron dextran intraperitoneal (0, 0,1, 0,3 mg/hari/ekor). Setelah 19 hari, mencit diterminasi, berat hepar ditimbang dan ekspresi gen gliserol kinase diukur dengan metode semi-kualitatif PCR. Kuantifikasi hasil PCR dilakukan dengan menggunakan aplikasi ImageJ. Terdapat peningkatan berat hepar secara signifikan yang sejalan dengan dosis ijeksi zat besi. Ekspresi gen gliserol kinase cenderung menurun, meskipun secara statistik tidak signifikan. Keadaan tinggi kadar zat besi yang akut meningkatkan berat hepar dan cenderung menurunkan ekspresi gen gliserol kinase pada hepar mencit.Kata kunci: Gliserol kinase, hepatosteatosis, zat besi berlebih


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