Table 1 - uploaded by Tian Tang
Content may be subject to copyright.
Source publication
Domestic ducks remain a major source of zoonotic Salmonella enterica infections for man worldwide and approaches to protection should include vaccine-mediated immunity. With this in mind we developed several genetically defined mutants in a virulent duck Salmonella typhimurium isolate TT-1. From initial tests for virulence in day-old ducks, ΔrpoS,...
Contexts in source publication
Context 1
... bacterial strains used in this study are listed in Table 1. Strains TH4702 (LT2 pKD46) and TH6701 (LT2araBAD925::tetRA) were kind gifts from Prof. Kelly T. Hughes at the University of Utah. ...
Context 2
... construction of tetRA insertion mutants and marker- less deletions followed protocols described previously [43]. The resulting insertion (TT-1 to TT-9) and deletion (TT-11 to TT- 16) derivatives are shown in Table 1. Strain TH6701 was used as template for PCR amplifying tetRA. ...
Context 3
... of ducks with 1.2 × 10 10 CFU of the TT-1 parental strains resulted in all birds dying. The results are shown in Table 1. ...
Context 4
... the assessments for virulence and persistence above, the phoPQ (TT-12), ompR (TT-13), clpP (TT-16), and ssrB (TT- 11) mutants were evaluated as live vaccines against challenge with the virulent parent strain TT-1. As shown in Table 1, ducks vacci- nated orally with 1.2 × 10 6 or 1.2 × 10 8 CFU of phoPQ or ompR mutant strain showed complete protection against lethal challenge. Groups of birds immunized with 1.2 × 10 8 cells of clpP or ssrB mutant strains showed partial protection (16/20 and 17/20 sur- vival, respectively). ...
Citations
... All bacterial strains used in this study were isogenic derivatives of Salmonella enterica serovar typhimurium (S. typhimurium) wild-type strain TT-1 or LT2 (Tang et al., 2015). Cells were routinely cultured in Luria-Bertani (LB) broth or on LB agar. ...
... In brief, the plasmid pKD46 was transformed into TT-5 (ΔphoPQ::tetRA TT-1) to generate TT-51 (ΔphoPQ::tetRA pKD46 TT-1). The forward primer #1011 combined with TT-1 This study TT-52 ΔphoP TT-1 This study TT-61 ΔaraBAD::tetRA ΔphoP TT-1 This study TT-80 ΔaraBAD TT-1 This study TT-81 ΔaraBAD ΔphoP TT-1 This study TT-82 ΔaraBAD::phoP ΔphoP TT-1 This study TT-92 ΔaraBAD::phoP-HA ΔphoP TT-1 This study the reverse primer #1012 was used to amplify the phoQ gene using the wild-type Salmonella TT-1 as a template (Tang et al., 2015). The PCR fragment was subsequently used to replace the tetRA gene in TT-51 (ΔphoPQ::tetRA pKD46 TT-1) via electroporation, selecting for fusaric acid resistance (Way et al., 1984). ...
Introduction
Previous reports revealed the role played by Salmonella PhoP–PhoQ system in virulence activation, antimicrobial tolerance and intracellular survival, the impact of PhoP–PhoQ on cell metabolism has been less extensively described.
Objectives
The aim of this study is to address whether and how the PhoP–PhoQ system affects the cell metabolism of Salmonella.
Methods
We constructed a Salmonella phoP deletion mutant strain TT-81 (PhoP-OFF), a Salmonella PhoP constitutively expressed strain TT-82 (PhoP-ON) and a wild-type Salmonella PhoP strain TT-80 (PhoP-N), using P22-mediated generalized transduction or λ Red-mediated targeted mutagenesis. We then measured the in vitro growth kinetics of all test strains and determined their metabolomic and transcriptomic profiles using gas chromatography coupled with tandem mass spectrometry (GC–MS/MS) and RNA-seq technique, respectively.
Results
Low-Mg²⁺ conditions impaired the growth of the phoP deletion mutant strain TT-81 (PhoP-OFF) dramatically. 42 metabolites in the wild-type PhoP strain TT-80 (PhoP-N) and 28 metabolites in the PhoP constitutively expressed strain TT-82 (PhoP-ON) changed by the absence of phoP. In contrast, the level of 19 compounds in TT-80 (PhoP-N) changed comparing to the PhoP constitutively expressed strain TT-82 (PhoP-N). The mRNA level of 95 genes in TT-80 (PhoP-N) changed when phoP was disrupted, wherein 78 genes downregulated and 17 genes upregulated. 106 genes were determined to be differentially expressed between TT-81 (PhoP-OFF) and TT-82 (PhoP-ON). While only 16 genes were found to differentially expressed between TT-82 (PhoP-ON) and TT-80 (PhoP-N).
Conclusion
Our findings confirmed the impact of PhoP–PhoQ system on lipopolysaccharide (LPS) modification, energy metabolism, and the biosynthesis or transport of amino acids. Most importantly, we demonstrated that the turnover of a given metabolite could respond differentially to the level of phoP. Taken together, the present study provided new insights into the adaptation of Salmonella to the host environment and helped to characterize the impact of the PhoP–PhoQ system on the cell metabolism.
... However, in the presence of the synthesized AgNPs and wild ginger extracts, the antibacterial activity was seen in the form of clear zones of inhibition. The antibacterial susceptibilities of MDR strains of different bacteria using ginger extracts were previously reported in different studies [11,41,42], including S. aureus [10]. It could be possible that the Ag component of AgNPs confers antimicrobial properties. ...
Antibiotic resistance rate is rising worldwide. Silver nanoparticles (AgNPs) are potent
for fighting antimicrobial resistance (AMR), independently or synergistically. The purpose of this study was to prepare AgNPs using wild ginger extracts and to evaluate the antibacterial efficacy of these AgNPs against multidrug-resistant (MDR) Staphylococcus aureus, Streptococcus mutans, and Enterococcus faecalis. AgNPs were synthesized using wild ginger extracts at room temperature through different parameters for optimization, i.e., pH and variable molar concentration. Synthesis of AgNPs was confirmed by UV/visible spectroscopy and further characterized by scanning electron
microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy analysis (EDXA), and Fourier-transform infrared spectroscopy (FTIR). Disc and agar well diffusion techniques were utilized to determine the in vitro antibacterial activity of plant extracts and AgNPs. The surface plasmon resonance peaks in absorption spectra for silver suspension showed the absorption maxima in the range of 400–420 nm. Functional biomolecules such as N–H, C–H, O–H, C–O, and C–O–C were present in Zingiber zerumbet (Z. zerumbet) (aqueous and organic extracts) responsible for the AgNP
formation characterized by FTIR. The crystalline structure of ZZAE-AgCl-NPs and ZZEE-AgCl-NPs was displayed in the XRD analysis. SEM analysis revealed the surface morphology. The EDXA analysis also confirmed the element of silver. It was revealed that AgNPs were seemingly spherical in morphology. The biosynthesized AgNPs exhibited complete antibacterial activity against the tested MDR bacterial strains. This study indicates that AgNPs of wild ginger extracts exhibit potent antibacterial activity against MDR bacterial strains.
... A wide variety of Salmonella serovers in different hosts like fowl, duck, pigeon remain as significant problem with importance to public health all over the world (Tabaraie et al., 1994). Salmonellosis is considered one of the important diseases which affected duckling from one to two weeks from its age causing significance level from morbidities and mortalities (Tang et al., 2015). Despite, older ducks can carry Salmonella germs even if they look healthy and clean. ...
... The S. typhimurium wild-type (WT) strain TT-1 and slyA deletion mutant TT-15 (ΔslyA) used in this study were described previously. 10 Strains were routinely cultured in M9 broth or on M9 agar at 37°C. For metabolite extraction, 250 μL of overnight culture of TT-1 or TT-15 was transferred into a 250 mL sterile flask containing 25 mL of fresh M9 broth. ...
SlyA is an important transcriptional regulator in Salmonella Typhimurium (S. typhimurium). Numerous reports have indicated the impact of SlyA on the virulence of S. typhimurium. Less information regarding the role of SlyA in cell metabolism of S. typhimurium is available. To close this gap, we compared the growth kenitics of a S. typhimurium wild type strain to a slyA deletion mutant strain. The data suggested that the cell growth of S. typhimurium was impaired when slyA abolished, indicating that SlyA might affect the cell metabolism of S. typhimurium. To determine the role of SlyA in cell metabolism, we analyzed the metabolite profiles of S. typhimurium in the presence or absence of slyA, using gas chromatography coupled with tandem mass spectrometry (GC-MS-MS). With the aim of appropriately interpreting the results obtained from metabolomics, a transcriptomic analysis on both the wildtype S. typhimurium and the slyA deletion mutant was performed. The metabolome data indicated that several glycolysis and lipid metabolism-associated pathways, including the turnover of glycerolipid, pyruvate, butanoate and glycerophospholipid, were affected in the absence of slyA. In addition, the mRNA levels of several genes associated with glycolysis and lipid turnover were downregulated when slyA was deleted, including pagP, fadL, mgtB, iacp and yciA. Collectively, these evidences suggested that SlyA affects the glycolysis and lipid turnover of S. typhimurium at transcriptional level. The raw data of metabolomics is available in Metabolights database with access number of MTBLS1858. The raw data of transcriptome is available in SRA database with access number of PRJNA656165.
... Unless otherwise stated, all chemicals used were chromatography grade. The S. typhimurium wild-type strain TT-1 used in this study was described previously [13]. Strains were inoculated into 1 mL of M9 liquid broth (2.56 g/L Na 2 PO 4 ·7H 2 O, 0.6 g/L KH 2 PO 4 , 0.1 g/L NaCl, 0.2 g/L NH 4 Cl, 2 mM MgSO 4 , 0.1 mM CaCl 2 , and 0.4% glucose), and shaken at 180 rev/min at 37 °C for 15 h. ...
Salmonella enterica serovar typhimurium (S. typhimurium) causes food poisoning in human and animals. Its infection rate is the highest among all salmonella serotypes. Metabolomics is a potential way to study the pathogenesis of S. typhimurium via analysis of various small molecular substances. Due to the lack of a uniform protocol for the extraction of metabolites, we evaluated five commonly used extraction methods including cold methanol (CM), hot ethanol (HE), chloroform–methanol cocktail (CMC), perchloric acid (PCA), and alkali (AL) for their efficacy in extracting the intracellular metabolites of S. typhimurium. Samples were quenched in 60% methanol at − 40 °C, and then the five methods were used to extract the metabolites. After derivatization, all samples were analyzed on a gas chromatography–triple quadrupole mass spectrometry (GC–MS/MS). Our results suggest that CM and HE extraction methods provide the best compromise allowing identification of 98 and 95 metabolites in a single analysis. For targeted metabolome analysis, the optimal extraction method for alcohols and organic acids is HE. CMC preferentially extracted lipid metabolites. PCA is suitable for extraction of small molecular carbohydrates. The optimal extraction method for macromolecular carbohydrates is the CM method.
... Generally studies addressing the success of vaccination against non-host-specific Salmonella serovars in poultry have yielded differing and sometimes conflicting results [5]. For chickens (reviewed by [24]) and ducks [25] live vaccines have been reported to confer protection against Salmonella infection. ...
Objective:
Human Salmonellosis continues to be one of the most important foodborne zoonoses worldwide, although a decrease in case numbers has been noted in recent years. It is a foodborne zoonotic infection most commonly associated with the consumption of raw egg products but also with meat consumption including the consumption of poultry products. Turkey flocks in Europe have been reported to be affected by Salmonella infection, too. The present study examines the efficacy of a newly licensed Salmonella life vaccine in reducing infections with the Salmonella serovars Typhimurium and Enteritidis in turkeys. Turkeys were vaccinated the first day of life and at the age of 6 and 16 weeks. Groups of birds which had received different numbers of vaccinations were then submitted to challenge trials with either SE or ST.
Results:
In vaccinated birds Salmonella counts in liver and spleen and, less effectively, in caecum were reduced compared to unvaccinated birds. In several groups serum antibody-titers were statistically significantly higher in vaccinated turkeys than in non-vaccinated ones at day seven post infection, but only in one out of six groups at day 14 post infection.
... Duck meat has traditionally been an important source of animal protein in many Asian countries; world production was approximately 4.4 million tons in 2013 [1]. Infectious diseases are therefore of increasing interest to the duck industry. ...
Background
Riemerella anatipestifer (RA), the causative agent of duck infectious serositis, leads to high mortality in duck flocks and great economic losses in duck industry. Previous studies on RA are largely focused on its detection, virulence factors, serology, epidemiology as well as antibiotic resistance. Neither drug tolerant persisters nor the persister level under the treatment of antibiotics has been revealed. The persisters are non-growing or dormant cells within an isogenic bacterial population; they play important roles in recurrent infection and formation of drug resistant mutants. The aim of this study is to detect the drug tolerant persisters from the exponentially grown population of RA reference strain (RA 11845) or RA clinical isolate (RA TQ3), and address whether a single antibiotic or a combination of two or three antimicrobials can eradicate the persisters at respective maximum serum/plasma concentration (Cmax).
Result
With the concentration of a test antibiotic increased, a small fraction of cells in the exponentially grown culture of RA reference strain (RA 11845) or RA clinical isolate (RA TQ3) always survived, irrespective of treatment time, indicating the presence of drug tolerant presisters. A single antibiotic cannot eradicate the persisters of both RA strains at respective Cmax, except that the Cmax of ceftiofur wiped out the population of the reference strain (RA 11845). Besides, the clinical isolate RA TQ3 presented a higher tolerance to ceftiofur in comparison to that of the reference strain (RA 11845). Combination of any two or three antimicrobials eliminated the drug tolerant persisters of RA TQ3 completely at respective Cmax.
Conclusion
A sub-community of drug tolerant persisters was present in RA population. Persisters of RA TQ3 are single drug tolerant and not multidrug tolerant persisters.
... In a previous study, we showed that the S. Typhimurium ompR mutant presents a growth advantage over the wild-type strain [19]. This unusual phenomenon prompts us to hypothesize a role of OmpR/EnvZ in cell metabolism. ...
The OmpR-EnvZ system which consists of a histidine kinase EnvZ and a response regulator OmpR is a global regulator in most gram-negative bacteria. In Salmonella Typhimurium (S. Typhimurium), OmpR-EnvZ directs the expression of hundreds of genes that are associated with virulence, porin formation, flagellum assembly and curli biosynthesis. In a previous report, we have shown that ompR inactivation promotes the growth rate of S. Ty-phimurium in vitro. This unusual phenomenon prompts us to investigate the role of OmpR-EnvZ in cell metabolism. By performing gas chromatography (GC) coupled with mass spectrometry (MS), we analyzed the extracellular and intracellular metabolite profiles of a S. Typhimurium wild-type (TT-1) strain and an ompR deletion mutant (TT-13). A total of 35 extracellular and 34 intracellular substances were identified in both strains, wherein, the levels of 16 extracellular compounds including L-leucine, L-methionine, L-aspartic acid, L-ornithine, L-phenylalanine, L-glutamic acid, L-lysine, L-tryptophan, glycolic acid, butanedioic acid, malic acid, phosphoric acid, citric acid, decanedioic acid, glycylglycine, myo-inositol and uridine were changed in an ompR mutant (TT-13) (P<0.05). Besides, ompR disruption also affects the intracellular biochemical reaction and results in accumulation or overconsumption of 11 endogenous substances, such as L-threonine, D-arabinose, glyceric acid, hexanedioic acid, ethanolamine, uracil, 6-hydroxypurine, serine, citric acid, cadaverine and putrescine. These evidences suggest a great impact of OmpR-EnvZ system on metabolite profile of S. Typhimurium.
... Although the function of ClpXP proteolytic system on protein degradation has been extensively studied, its role in regulation of cell metabolism requires considerable investigation given that clpP disruption severely impairs the growth kinetics of several bacterial species, including S. typhimurium (Thomsen et al. 2002;Knudsen et al. 2014;Tang et al. 2015), E. coli (Damerau and St John 1993), Staphylococcus (Wang et al. 2007), Pseudomonas (De Bruijn and Raaijmakers 2009), and Streptococcus (Kajfasz et al. 2011). A recent report indicated that introduction of a second rpoS deletion can restore the growth of a S. typhimurium clpP mutant to the wild-type level (Knudsen et al. 2014), prompting us to hypothesize that ClpXP affects the cell metabolism of S. typhimurium in an RpoS-dependent manner. ...
... The S. typhimurium wild-type strain TT-1 and its isogenic derivatives TT-7 (ΔrpoS::tetRA TT-1), TT-14 (ΔrpoS TT-1), and TT-16 (ΔclpP TT-1) used in this study were described previously (Tang et al. 2015). To construct a clpP ropS double deletion mutant, we performed a two-step phage transduction assay. ...
... clpP inactivation severely impairs the growth of S. typhimurium in vitro (Thomsen et al. 2002;Knudsen et al. 2014;Tang et al. 2015). Knudsen et al. observed that the growth of a S. typhimurium clpP mutant is restored to the wildtype level upon the deletion of rpoS (Knudsen et al. 2014). ...
Introduction
ClpXP protease is an important proteolytic system in Salmonella enterica serovar typhimurium (S. typhimurium). Inactivation of ClpXP by deletion of clpP resulted in overproduction of RpoS and a growth defect phenotype. Only one report has indicated that deleting rpoS can restore the growth of a S. typhimurium clpP mutant to the wild-type level. Whether overproduction of RpoS is responsible for the growth deficiency resulting from clpP disruption and how ClpXP affects the cell metabolism of S. typhimurium remain to be elucidated.
Objectives
The aim of this study is to investigate the effect of ClpXP on cell metabolism of S. typhimurium and explore the possible co-effect of RpoS associated with ClpXP in cell metabolism.
Method
We constructed a clpP rpoS double deletion mutant TT-19 (ΔclpP ΔrpoS TT-1) using a two-step phage transduction technique. We then compared the metabolite fingerprints of Salmonella rpoS deletion mutant TT-14 (ΔrpoS TT-1), clpP deletion mutant TT-16 (ΔclpP TT-1), and clpP rpoS double deletion mutant TT-19 (ΔclpP ΔrpoS TT-1) with those of the wild-type strain TT-1 by using gas chromatography coupled with mass spectrometry (GC–MS).
Results
Deletion of rpoS recovered only a part of the growth of Salmonella clpP mutant. Further metabolome analysis indicated that clpP disruption changed the levels of 16 extra- and 19 intracellular substances, while the extracellular concentrations of 4 compounds (serine, l-5-oxoproline, l-glutamic acid, and l-tryptophan) and intracellular concentrations of 10 compounds (l-isoleucine, glycine, serine, l-methionine, l-phenylalanine, malic acid, citric acid, urea, putrescine, and 6-hydroxypurine) returned to their wild-type levels when rpoS was also deleted.
Conclusion
ClpXP affects the cell metabolism of S. typhimurium partially in an RpoS-dependent manner.
... Moreover, Shigella species were detected in 2 (0.25%) of previously examined chicken samples (Ahmed and Shimamoto, 2014). Isolation of Salmonella serovars from ducks has been also recorded from many countries including Egypt (Osman et al., 2014;Tang et al., 2015). In addition, previously examined raw duck meat has been shown to be a reservoir of Salmonella species, especially S. typhimurium (Adzitey et al., 2012). ...
... In the present study, all the isolated Salmonella and Shigella strains were multidrug resistance pathogens as summarized inTable 1. The administration of antibiotic for treatment of Salmonella or as growth promoters resulted in development of varying degree of Salmonella resistant strains as recorded byCarrique-Mas et al. (2008), Osman et al. (2014; andTang et al. (2015). A multidrug-resistant (MDR) Salmonella have been previously recorded (Tsai and Hsiang, 2005;Cha et al., 2013;Chang et al., 2014;Tang et al., 2015). ...
... The administration of antibiotic for treatment of Salmonella or as growth promoters resulted in development of varying degree of Salmonella resistant strains as recorded byCarrique-Mas et al. (2008), Osman et al. (2014; andTang et al. (2015). A multidrug-resistant (MDR) Salmonella have been previously recorded (Tsai and Hsiang, 2005;Cha et al., 2013;Chang et al., 2014;Tang et al., 2015). This study presents a pilot study to answer how to overcome antibiotic-resistant Salmonella and Shigella. ...
The main objective of the present study is to find an appropriate in-vitro therapy to overcome clinically isolated
antibiotic-resistant Salmonella and Shigella species from cases of layer poultry farms suffering from purulent
dysentery and diarrhea. The present study demonstrated chemical synthesis of silver nanoparticles (AgNPs) via
chemical reduction method and investigation for their antibacterial effect against the isolated bacteria by
determining their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Of
32 examined samples, 8 (25%) antibiotic-resistant isolates were isolated and identified including: Shigella
flexneri, Salmonella typhimurium (two), Salmonella poona, Shigella boydii, Salmonella montevideo, Shigella
sonnei, Salmonella enteritidis. Spherical AgNPs of 10-25 nm in size were synthesized and the AgNPs at a
concentration of 16 μgml-1 were found to have both bacteriostatic and bactericidal effects in the case of
Salmonella montevideo (layer chicken egg), Shigella sonnei (layer chicken feces), Salmonella enteritidis (layer
duck egg) however the AgNPs at a concentration of 8 μgml-1 were found to have both bacteriostatic and
bactericidal effects in the case of Salmonella poona (layer chicken feces), Shigella boydii (layer chicken feces),
Salmonella typhimurium (layer chicken feces).
