scholarly journals Emergence of ciprofloxacin heteroresistance in foodborne Salmonella enterica serovar Agona

2020 ◽  
Vol 75 (10) ◽  
pp. 2773-2779
Author(s):  
Chuan-Zhen Zhang ◽  
Yan Zhang ◽  
Xiao-Min Ding ◽  
Xiao-Ling Lin ◽  
Xin-Lei Lian ◽  
...  

Abstract Background Bacterial heteroresistance has been increasingly identified as an important phenomenon for many antibiotic/bacterium combinations. Objectives To investigate ciprofloxacin heteroresistance in Salmonella and characterize mechanisms contributing to ciprofloxacin heteroresistance. Methods Ciprofloxacin-heteroresistant Salmonella were identified by population analysis profiling (PAP). Target mutations and the presence of PMQR genes were detected using PCR and sequencing. Expression of acrB, acrF and qnrS was conducted by quantitative RT–PCR. Competition ability and virulence were also compared using pyrosequencing, blue/white screening, adhesion and invasion assays and a Galleria model. Two subpopulations were whole-genome sequenced using Oxford Nanopore and Illumina platforms. Results PAP identified one Salmonella from food that yielded a subpopulation demonstrating heteroresistance to ciprofloxacin at a low frequency (10−9 to 10−7). WGS and PFGE analyses confirmed that the two subpopulations were isogenic, with six SNPs and two small deletions distinguishing the resistant from the susceptible. Both subpopulations possessed a T57S substitution in ParC and carried qnrS. The resistant subpopulation was distinguished by overexpression of acrB and acrF, a deletion within rsxC and altered expression of soxS. The resistant population had a competitive advantage against the parental population when grown in the presence of bile salts but was attenuated in the adhesion and invasion of human intestinal cells. Conclusions We determined that heteroresistance resulted from a combination of mutations in fluoroquinolone target genes and overexpression of efflux pumps associated with a deletion in rsxC. This study warns that ciprofloxacin heteroresistance exists in Salmonella in the food chain and highlights the necessity for careful interpretation of antibiotic susceptibility.

2012 ◽  
Vol 153 (52) ◽  
pp. 2051-2059 ◽  
Author(s):  
Zsuzsanna Gaál ◽  
Éva Oláh

MicroRNAs are a class of small non-coding RNAs regulating gene expression at posttranscriptional level. Their target genes include numerous regulators of cell cycle, cell proliferation as well as apoptosis. Therefore, they are implicated in the initiation and progression of cancer, tissue invasion and metastasis formation as well. MicroRNA profiles supply much information about both the origin and the differentiation state of tumours. MicroRNAs also have a key role during haemopoiesis. An altered expression level of those have often been observed in different types of leukemia. There are successful attempts to apply microRNAs in the diagnosis and prognosis of acute lymphoblastic leukemia and acute myeloid leukemia. Measurement of the expression levels may help to predict the success of treatment with different kinds of chemotherapeutic drugs. MicroRNAs are also regarded as promising therapeutic targets, and can contribute to a more personalized therapeutic approach in haemato-oncologic patients. Orv. Hetil., 2012, 153, 2051–2059.


Author(s):  
Mona Hussein ◽  
Rehab Magdy

AbstractMicroRNAs (miRNAs) are a class of short, non-coding, regulatory RNA molecules that function as post transcriptional regulators of gene expression. Altered expression of multiple miRNAs was found to be extensively involved in the pathogenesis of different neurological disorders including Alzheimer’s disease, Parkinson’s disease, stroke, epilepsy, multiple sclerosis, amyotrophic lateral sclerosis, and Huntington’s disease. miRNAs are implicated in the pathogenesis of excitotoxicity, apoptosis, oxidative stress, inflammation, neurogenesis, angiogenesis, and blood–brain barrier protection. Consequently, miRNAs can serve as biomarkers for different neurological disorders. In recent years, advances in the miRNA field led to identification of potentially novel prospects in the development of new therapies for incurable CNS disorders. MiRNA-based therapeutics include miRNA mimics and inhibitors that can decrease or increase the expression of target genes. Better understanding of the mechanisms by which miRNAs are implicated in the pathogenesis of neurological disorders may provide novel targets to researchers for innovative therapeutic strategies.


2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Amir Hossein Hasani Fard ◽  
Hanieh Jalali ◽  
Homa Mohseni Kouchesfehani

Background: Cholestasis is a pathophysiological condition, significantly reducing spermatozoa production. MiR-34c is highly expressed in adult male testicles and controls different stages of spermatogenesis. Objectives: Here, we aimed to investigate miR-34c expression in the testes of rat models of cholestasis. The expressions of THY-1, FGF-2, and CASP-3 genes, that are targeted by mirR-34c were also investigated. Methods: Cholestasis was induced in six adult rats via bile duct ligation. Four weeks after cholestasis induction, sera and testicular tissues were collected for further examinations. The levels of liver enzymes were measured using the ELISA. The structure of the testes was evaluated by histological examination. Total RNA was extracted from testes using a special kit and converted to cDNA. The expressions of miR-34c-5p, THY-1, FGF-2, and CASP-3 genes were determined by Real-Time PCR. Results: The serum levels of ALP, AST, and ALT were significantly elevated in the rat models of cholestasis (P < 0.001). Real-Time PCR revealed that the expressions of miR-34c-5p, THY-1, and FGF-2 genes decreased while CASP-3 gene was upregulated in the testes of cholestatic animals (all differences were significant at P < 0.05). Conclusions: Our study indicated that cholestasis was associated with reduced expression of miR-34c and altered expression of its target genes in the testis. Our results highlight the potential effects of cholestasis, a hepatobiliary disease, on testicular tissue function and male fertility.


2003 ◽  
Vol 47 (3) ◽  
pp. 923-931 ◽  
Author(s):  
Takaji Fujimura ◽  
Yoshinori Yamano ◽  
Isamu Yoshida ◽  
Jingoro Shimada ◽  
Shogo Kuwahara

ABSTRACT The in vitro antibacterial activity of S-3578, a new parenteral cephalosporin, against clinical isolates was evaluated. The MICs of the drug at which 90% of the isolates were inhibited were 4 μg/ml for methicillin-resistant Staphylococcus aureus (MRSA) and 2 μg/ml for methicillin-resistant Staphylococcus epidermidis, which were fourfold higher than and equal to those of vancomycin, respectively. The anti-MRSA activity of S-3578 was considered to be due to its high affinity for penicillin-binding protein 2a (50% inhibitory concentration, 4.5 μg/ml). In time-kill studies with 10 strains each of MRSA and methicillin-susceptible S. aureus, S-3578 caused more than a 4-log10 decrease of viable cells on the average at twice the MIC after 24 h of exposure, indicating that it had potent bactericidal activity. Furthermore, in population analysis of MRSA strains with heterogeneous or homogeneous resistance to imipenem, no colonies emerged from about 109 cells on agar plates containing twice the MIC of S-3578, suggesting the low frequency of emergence of S-3578-resistant strains from MRSA. S-3578 was also highly active against penicillin-resistant Streptococcus pneumoniae (PRSP), with a MIC90 of 1 μg/ml, which was comparable to that of ceftriaxone. S-3578 also had antibacterial activity against a variety of gram-negative bacteria including Pseudomonas aeruginosa, though its activity was not superior to that of cefepime. In conclusion, S-3578 exhibited a broad antibacterial spectrum and, particularly, had excellent activity against gram-positive bacteria including methicillin-resistant staphylococci and PRSP. Thus, S-3578 was considered to be worthy of further evaluation.


Development ◽  
1992 ◽  
Vol 116 (2) ◽  
pp. 335-346 ◽  
Author(s):  
M. Freeman ◽  
B.E. Kimmel ◽  
G.M. Rubin

In order to identify potential target genes of the rough homeodomain protein, which is known to specify some aspects of the R2/R5 photoreceptor subtype in the Drosophila eye, we have carried out a search for enhancer trap lines whose expression is rough-dependent. We crossed 101 enhancer traps that are expressed in the developing eye into a rough mutant background, and have identified seven lines that have altered expression patterns. One of these putative rough target genes is rhomboid, a gene known to be required for dorsoventral patterning and development of some of the nervous system in the embryo. We have examined the role of rhomboid in eye development and find that, while mutant clones have only a subtle phenotype, ectopic expression of the gene causes the non-neuronal mystery cells to be transformed into photoreceptors. We propose that rhomboid is a part of a partially redundant network of genes that specify photoreceptor cell fate.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Prithvi Raj ◽  
Ran Song ◽  
Honglin Zhu ◽  
Linley Riediger ◽  
Dong-Jae Jun ◽  
...  

Abstract Background Systemic lupus erythematosus (SLE) is a clinically heterogeneous autoimmune disease characterized by the development of anti-nuclear antibodies. Susceptibility to SLE is multifactorial, with a combination of genetic and environmental risk factors contributing to disease development. Like other polygenic diseases, a significant proportion of estimated SLE heritability is not accounted for by common disease alleles analyzed by SNP array-based GWASs. Death-associated protein 1 (DAP1) was implicated as a candidate gene in a previous familial linkage study of SLE and rheumatoid arthritis, but the association has not been explored further. Results We perform deep sequencing across the DAP1 genomic segment in 2032 SLE patients, and healthy controls, and discover a low-frequency functional haplotype strongly associated with SLE risk in multiple ethnicities. We find multiple cis-eQTLs embedded in a risk haplotype that progressively downregulates DAP1 transcription in immune cells. Decreased DAP1 transcription results in reduced DAP1 protein in peripheral blood mononuclear cells, monocytes, and lymphoblastoid cell lines, leading to enhanced autophagic flux in immune cells expressing the DAP1 risk haplotype. Patients with DAP1 risk allele exhibit significantly higher autoantibody titers and altered expression of the immune system, autophagy, and apoptosis pathway transcripts, indicating that the DAP1 risk allele mediates enhanced autophagy, leading to the survival of autoreactive lymphocytes and increased autoantibody. Conclusions We demonstrate how targeted sequencing captures low-frequency functional risk alleles that are missed by SNP array-based studies. SLE patients with the DAP1 genotype have distinct autoantibody and transcription profiles, supporting the dissection of SLE heterogeneity by genetic analysis.


2020 ◽  
Vol 2 ◽  
Author(s):  
Ayako Nishizawa-Yokoi ◽  
Masafumi Mikami ◽  
Seiichi Toki

Homologous recombination-mediated genome editing, also called gene targeting (GT), is an essential technique that allows precise modification of a target sequence, including introduction of point mutations, knock-in of a reporter gene, and/or swapping of a functional domain. However, due to its low frequency, it has been difficult to establish GT approaches that can be applied widely to a large number of plant species. We have developed a simple and universal clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated DNA double-strand break (DSB)-induced GT system using an all-in-one vector comprising a CRISPR/Cas9 expression construct, selectable marker, and GT donor template. This system enabled introduction of targeted point mutations with non-selectable traits into several target genes in both rice and tobacco. Since it was possible to evaluate the GT frequency on endogenous target genes precisely using this system, we investigated the effect of treatment with Rad51-stimulatory compound 1 (RS-1) on the frequency of DSB-induced GT. GT frequency was slightly, but consistently, improved by RS-1 treatment in both target plants.


Open Medicine ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. 83-86 ◽  
Author(s):  
Defeng Peng ◽  
Lin Fu ◽  
Guoping Sun

AbstractThe TGF-β/SMAD signaling pathway is found to play pivotal roles in cell growth, differentiation and tumorigenesis. Its target genes are closely related to the biological behaviors of some malignancies. The aim of this study was to analyze the expression of the target genes of this pathway, including growth-related c-myc, p21, p15, and metastasis-related Snail, ZEB1 and Twist1 in the adenocarcinomas of esophagogastric junction (AEJ) tissues. Clinical esophagogastric junction tissues from 25 cases of AEJ patients and 10 cases of non-tumorous tissues from the same site were collected. Quantitative real-time poly chain reactions were carried out to analyze the expression of the above referred target genes of TGF-β/SMAD pathway. A notable up-regulation in the mRNA expression of p15, Snail, ZEB1, down-regulation of c-myc, was found whereas there were no significant change of p21 and Twist1. The findings suggests that the TGF-β/SMAD pathway might be abnormally activated in AEJ since most of the target genes of this pathway exhibited altered expression at mRNA level.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4950-4950
Author(s):  
Christian Bastard ◽  
Christophe Fruchart ◽  
Gregory Raux ◽  
Francoise Parmentier ◽  
Dominique Vaur ◽  
...  

Abstract Four chromosomal defects associated with prognosis have been identified in CLL patients, namely deletions of the 13q13-q14, 11q22 and 17p13 regions and trisomy 12. Due to the low proliferation index of these tumors and to the fact that some defects can be cryptic, the detection of these abnormalities by conventional cytogenetics is difficult. Therefore, the resulting aneuploidies are usually evaluated by fluorescent in situ hybridisation (FISH). As probes are expensive and FISH time consuming, we aimed to compare a quantitative PCR method - quantitative PCR of short fluorescent fragments (QMPSF) - with FISH for the detection of these acquired aneuploidies in a series of 110 patients with Binet stage A CLL. Genes located in the deleted or gained regions were selected as target genes - DLEU2 at 13q14, ATM at 11q22, p53 at 17p13, POU6F1 and MDM2 at 12q13 and 12q15 respectively - and amplified using a method based on the simultaneous amplification of short fluorescent genomic fragments under quantitative conditions. A chromosomal imbalance involving one or several of the four loci was detected in 76 patients (69%) either by FISH or QMPSF or both. A deletion of chromosome 13 was found in 61 patients (55%). A 11q22 deletion was present in 9 patients (8%), a trisomy 12 in 9 (8%) and a 17p deletion in one. The rather low frequency of the three latter defects reflects the fact that only patients with stage A CLL at diagnosis were studied, and neither stage B or C CLL. The 13q deletion was isolated in 53 patients and associated with a second defect in 8: these were six of the 11q22 deletions, one trisomy 12 and the 17p deletion. When the 13q deletion was associated with either a 11q deletion or a trisomy 12 both abnormalities were present in the same proportion of cells. This was not the case for the 17p deletion which appeared to be a secondary event, since, as evaluated by FISH, it was present in 24% of cells whereas the 13q deletion was present in 85% of interphase nuclei. FISH and QMPSF results were identical for 103 of 110 patients. The secondary 17p deletion was not detected whereas all other discrepancies could be explained. This study demonstrates that a single multiplex PCR can replace FISH in CLL patients. However, whereas QMPSF is perfectly adapted to the detection of primary defects, care should be taken when searching for minor clonal evolutions present in a small proportion of tumor cells.


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