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1.
Background
Salmonella spp. have been isolated from a wide range of wild animals. Opportunistic wild carnivores such as red foxes (Vulpes vulpes) and badgers (Meles meles) may act as environmental indicators or as potential sources of salmonellosis in humans. The present study characterizes Salmonella spp. isolated from the intestinal contents of hunted or dead red foxes (n?=?509) and badgers (n?=?17) in northern Italy.Findings
Thirty-one strains of Salmonella belonging to 3 Salmonella enterica subspecies were isolated. Fourteen different serovars of S. enterica subsp. enterica were identified, among which were serovars often associated with human illness.Conclusions
Wild opportunistic predators can influence the probability of infection of both domestic animals and humans through active shedding of the pathogen to the environment. The epidemiological role of wild carnivores in the spread of salmonellosis needs to be further studied.2.
3.
Pei Han Yong Huang Yumin Xie Wu Yang Wenying Xiang Peter J. Hylands Cristina Legido-Quigley 《Metabolomics : Official journal of the Metabolomic Society》2018,14(7):91
Introduction
In spite of advances in antibiotics, urinary tract infection (UTI) is still among the most common reasons for antibiotic medication worldwide. Persicaria capitata (Buch.-Ham. ex D. Don) H.Gross (P. capitata) is a herbal medicine used by the Miao people in China to treat UTI. However studies of its mechanism are challenging, owing to the complexity of P. capitata with multiple constituents acting on multiple metabolic pathways.Objective
The objective of this study was to explore the working mechanism of P. capitata on urinary tract infection.Methods
Relinqing® granule, which is solely made from aqueous extracts of the whole P. capitata plant, was used in this study. Urine metabolomics based on gas chromatography-mass spectroscopy was employed to assess the metabolic changes caused by administration of Relinqing® granule in a UTI mouse model. Female specific-pathogen-free Kunming mice were divided into control group (mock infection, saline treatment), model group (E.coli infection, saline treatment), Relinqing® group (E.coli infection, Relinqing® granule treatment), ciprofloxacin group (E.coli infection, ciprofloxacin treatment), and sham-Relinqing® group (no surgery, Relinqing® granule treatment).Results
The results showed that after the treatments, urine levels of itaconic acid in Relinqing® group increased by 4.9 fold and 11.3 fold compared with model and ciprofloxacin groups respectively. Itaconic acid is an endogenous antibacterial metabolite produced by macrophages, which also functions as a checkpoint for metabolic reprogramming of macrophage.Conclusion
Our findings suggest that this herbal medicine can cure urinary tract infection through modulation of immune system.4.
Lae-seung Jung Tian Ding Juhee Ahn 《Annals of clinical microbiology and antimicrobials》2017,16(1):66
Background
The emergence of antibiotic-resistant bacteria can cause serious clinical and public health problems. This study describes the possibility of using bacteriophages as an alternative agent to control multidrug-resistant Salmonella Typhimurium.Methods
The potential lytic bacteriophages (P22-B1, P22, PBST10, PBST13, PBST32, and PBST 35) were characterized by morphological property, heat and pH stability, optimum multiplicity of infection (MOI), and lytic activity against S. Typhimurium KCCM 40253, S. Typhimurium ATCC 19585, ciprofloxacin-induced antibiotic-resistant S. Typhimurium ATCC 19585, and S. Typhimurium CCARM 8009.Results
P22-B1 and P22 belong to Podoviridae family and PBST10, PBST13, PBST32, and PBST 35 show a typical structure with polyhedral head and long tail, belonging to Siphoviridae family. Salmonella bacteriophages were highly stable at the temperatures (< 60 °C) and pHs (5.0–11.0). The reduction rates of host cells were increased at the MOI-dependent manner, showing the highest reduction rate at MOI of 10. The host cells were most effectively reduced by P22, while P22-B1 showed the least lytic activity. The ciprofloxacin-induced antibiotic-resistant S. Typhimurium ATCC 19585, and clinically isolated antibiotic-resistant S. Typhimurium CCARM 8009 were resistant to ciprofloxacin, levofloxacin, norfloxacin, and tetracycline. P22 showed the highest lytic activity against S. Typhimurium KCCM 40253 (> 5 log reduction), followed by S. Typhimurium ATCC 19585 (4 log reduction) and ciprofloxacin-induced antibiotic-resistant S. Typhimurium ATCC 19585 (4 log reduction).Conclusion
The results would provide vital insights into the application of lytic bacteriophages as an alternative therapeutics for the control of multidrug-resistant pathogens.5.
Thijs Welle Anna T. Hoekstra Ineke A. J. J. M. Daemen Celia R. Berkers Matheus O. Costa 《Metabolomics : Official journal of the Metabolomic Society》2017,13(7):83
Introduction
Swine dysentery caused by Brachyspira hyodysenteriae is a production limiting disease in pig farming. Currently antimicrobial therapy is the only treatment and control method available.Objective
The aim of this study was to characterize the metabolic response of porcine colon explants to infection by B. hyodysenteriae.Methods
Porcine colon explants exposed to B. hyodysenteriae were analyzed for histopathological, metabolic and pro-inflammatory gene expression changes.Results
Significant epithelial necrosis, increased levels of l-citrulline and IL-1α were observed on explants infected with B. hyodysenteriae.Conclusions
The spirochete induces necrosis in vitro likely through an inflammatory process mediated by IL-1α and NO.6.
Ying-ge Wang Jin-mei Cheng Hai-bo Ding Xi Lin Guo-hao Chen Mei Zhou Sheng-nan Ye 《Mycopathologia》2018,183(3):551-558
Objective
To improve the diagnosis and treatment of Penicilliosis marneffei without human immunodeficiency virus infection.Methods
Analyze and review the clinical features, diagnosis and treatment of six cases of P. marneffei without human immunodeficiency virus infection at The First Affiliated Hospital of Fujian Medical University.Results
Two cases were diagnosed in the ENT Department, three cases in the respiratory department and one case in the dermatological department. Penicillium marneffei infection was confirmed by sputum culture, blood culture and tissue biopsy. After definite diagnosis, one refused further treatment, and others showed significant improvement.Conclusion
Penicilliosis marneffei is insidious onset and easy to be escaped and misdiagnosed. To achieve early diagnosis and appropriate treatment, doubtful cases should be alerted for the diagnoses as P. marneffei.7.
David F. Duneau Hannah C. Kondolf Joo Hyun Im Gerardo A. Ortiz Christopher Chow Michael A. Fox Ana T. Eugénio J. Revah Nicolas Buchon Brian P. Lazzaro 《BMC biology》2017,15(1):124
Background
Host sexual dimorphism is being increasingly recognized to generate strong differences in the outcome of infectious disease, but the mechanisms underlying immunological differences between males and females remain poorly characterized. Here, we used Drosophila melanogaster to assess and dissect sexual dimorphism in the innate response to systemic bacterial infection.Results
We demonstrated sexual dimorphism in susceptibility to infection by a broad spectrum of Gram-positive and Gram-negative bacteria. We found that both virgin and mated females are more susceptible than mated males to most, but not all, infections. We investigated in more detail the lower resistance of females to infection with Providencia rettgeri, a Gram-negative bacterium that naturally infects D. melanogaster. We found that females have a higher number of phagocytes than males and that ablation of hemocytes does not eliminate the dimorphism in resistance to P. rettgeri, so the observed dimorphism does not stem from differences in the cellular response. The Imd pathway is critical for the production of antimicrobial peptides in response to Gram-negative bacteria, but mutants for Imd signaling continued to exhibit dimorphism even though both sexes showed strongly reduced resistance. Instead, we found that the Toll pathway is responsible for the dimorphism in resistance. The Toll pathway is dimorphic in genome-wide constitutive gene expression and in induced response to infection. Toll signaling is dimorphic in both constitutive signaling and in induced activation in response to P. rettgeri infection. The dimorphism in pathway activation can be specifically attributed to Persephone-mediated immune stimulation, by which the Toll pathway is triggered in response to pathogen-derived virulence factors. We additionally found that, in absence of Toll signaling, males become more susceptible than females to the Gram-positive Enterococcus faecalis. This reversal in susceptibility between male and female Toll pathway mutants compared to wildtype hosts highlights the key role of the Toll pathway in D. melanogaster sexual dimorphism in resistance to infection.Conclusion
Altogether, our data demonstrate that Toll pathway activity differs between male and female D. melanogaster in response to bacterial infection, thus identifying innate immune signaling as a determinant of sexual immune dimorphism.8.
Background
Tuberculosis, the disease due to Mycobacterium tuberculosis, is an important cause of morbidity and mortality in the elderly. Use of mouse models may accelerate insight into the disease and tests of therapies since mice age thirty times faster than humans. However, the majority of TB research relies on inbred mouse strains, and these results might not extrapolate well to the genetically diverse human population. We report here the first tests of M. tuberculosis infection in genetically heterogeneous aging mice, testing if old mice benefit from rapamycin.Findings
We find that genetically diverse aging mice are much more susceptible than young mice to M. tuberculosis, as are aging human beings. We also find that rapamycin boosts immune responses during primary infection but fails to increase survival.Conclusions
Genetically diverse mouse models provide a valuable resource to study how age influences responses and susceptibility to pathogens and to test interventions. Additionally, surrogate markers such as immune measures may not predict whether interventions improve survival.9.
10.
Jinguo Liu Lin Yu Cuicui Chen Jian Zhou Xin Gong Dandan Li Dongni Hou Yuanlin Song Changzhou Shao 《Mycopathologia》2018,183(2):337-348
Background
C-type lectin receptors (CLRs), Toll-like receptors (TLRs), and Nod-like receptors (NLRs) have the ability to recognize Aspergillus fumigatus (A. fumigates) and induce innate immune response. Dectin-1 is a well-described CLR, while interleukin-1 receptor-associated kinase 1 (Irak1) and receptor-interacting protein 2 (Rip2) are pivotal adaptor proteins of TLRs and NLRs signaling pathways, respectively.Objectives
Our primary aim is to elucidate whether Dectin-1 regulates the expression of Irak1 and Rip2, and confirm that CLRs, TLRs, and NLRs pathways act synergistically in response to A. fumigatus infection.Methods
Pulmonary infection mouse models were established. Myeloid cells were differentiated in cell culture and examined by inverted microscopy, flow cytometry, and scanning electron microscopy. The relative mRNA levels were determined by qRT-PCR. The protein expression levels were determined by immunohistochemistry and Western blot.Results
The expression of Dectin-1, Irak1, Rip2, and phosphorylation level of nuclear factor (NF)-κB p65 were induced by conidia in immunocompetent mice, while their expression and phosphorylation level were inhibited in immunocompromised mice after the administration of conidia. Conidia increased the expression of Dectin-1, Irak1, and Rip2 in myeloid cells, while Dectin-1 silencing significantly reduced their expression.Conclusion
Our findings demonstrate that Dectin-1, Irak1, and Rip2 are involved in response to A. fumigatus infection. Dectin-1 modulates the expression of Irak1 and Rip2. Additionally, these three signaling pathways are interconnected, and CLRs pathway plays a dominant role against A. fumigatus invasion.11.
Wenyi Sun Xiaobing Yang Xueying Wang Xiang Jiao Sufang Zhang Yushi Luan Zongbao K. Zhao 《Biotechnology letters》2018,40(6):933-940
Objectives
To establish a recombinase flippase (FLP) and flippase recognition target (FRT) system-mediated protocol for post-integration excision of exogenous DNA fragments in the oleaginous yeast Rhodosporidium toruloides.Results
Binary vectors were constructed to harbor FLP expressing cassette together with the hygromycin-resistance marker. Results showed that R. toruloides transformants produced FLP, but failed to mediate removal of the bleomycin-resistance marker within two FRT sites. When FLP was fused with a native nuclear localization signal (NLS) peptide, the system was found functional. Moreover, R. toruloides recombinant strains expressing the NLS-fused FLP under the control of PADH2, an promoter of alcohol dehydrogenase 2 gene (RHTO_03062), were obtained to realize homologous recombination upon growing in glucose-deficient medium.Conclusions
We have devised a homologous recombination method for R. toruloides based on the FLP/FRT system, which may facilitate further metabolic engineering and designing advanced cell factories for value-added chemicals.12.
Nicholas J. Bond Albert Koulman Julian L. Griffin Zoe Hall 《Metabolomics : Official journal of the Metabolomic Society》2017,13(11):128
Introduction
Mass spectrometry imaging (MSI) experiments result in complex multi-dimensional datasets, which require specialist data analysis tools.Objectives
We have developed massPix—an R package for analysing and interpreting data from MSI of lipids in tissue.Methods
massPix produces single ion images, performs multivariate statistics and provides putative lipid annotations based on accurate mass matching against generated lipid libraries.Results
Classification of tissue regions with high spectral similarly can be carried out by principal components analysis (PCA) or k-means clustering.Conclusion
massPix is an open-source tool for the analysis and statistical interpretation of MSI data, and is particularly useful for lipidomics applications.13.
Background
The occurrence of Salmonella enterica subspecies diarizonae serovar 61: k: 1, 5, (7) (SASd) and other Salmonella organisms in sheep in the German federal state of Thuringia was examined for the first time. Pooled faecal samples from 90 flocks located in this state were monitored.Results
Only SASd was detected in 74 (82.2%) out of the 90 sheep herds, other Salmonella serovars were not identified. A positive correlation was found between the flock size and the detection probability of SASd. Despite the agent’s high prevalence, clinical symptoms of a disease exclusively due to SASd have not been observed. The SASd strains were characterised by macrorestriction analysis, antimicrobial testing and the biochemical profile. All strains were sensitive to 13 out of 14 antimicrobial substances and resistant to only sulfamethoxazole. The high number of macrorestriction groups of SASd strains indicated a low clonality of the serovar.Conclusions
Data from sheep derived foods and public health data in Germany strongly suggest that the significance of SASd for public health is considerably lower than that of serovars belonging to Salmonella enterica subspecies enterica. For this reason and because of the low disease-causing potential of SASd in sheep, it is worthwile to consider a reduction in ongoing activities from combating to monitoring serovar 61: k: 1, 5, (7) in the sheep population.14.
Wenyi Sun Xiaobing Yang Xueying Wang Xinping Lin Yanan Wang Sufang Zhang Yushi Luan Zongbao K. Zhao 《Biotechnology letters》2017,39(7):1001-1007
Objectives
To target a carotenoid biosynthetic gene in the oleaginous yeast Rhodosporidium toruloides by using the Agrobacterium-mediated transformation (AMT) method.Results
The RHTO_04602 locus of R. toruloides NP11, previously assigned to code the carotenoid biosynthetic gene CRTI, was amplified from genomic DNA and cloned into the binary plasmid pZPK-mcs, resulting in pZPK-CRT. A HYG-expression cassette was inserted into the CRTI sequence of pZPK-CRT by utilizing the restriction-free clone strategy. The resulted plasmid was used to transform R. toruloides cells according to the AMT method, leading to a few white transformants. Sequencing analysis of those transformants confirmed homologous recombination and insertional inactivation of CRTI. When the white variants were transformed with a CRTI-expression cassette, cells became red and produced carotenoids as did the wild-type strain NP11.Conclusions
Successful homologous targeting of the CrtI locus confirmed the function of RHTO_04602 in carotenoids biosynthesis in R. toruloides. It provided valuable information for metabolic engineering of this non-model yeast species.15.
Ayman A. Elshayeb Abdelazim A. Ahmed Marmar A. El Siddig Adil A. El Hussien 《Annals of clinical microbiology and antimicrobials》2017,16(1):73
Background
Enteric fever has persistence of great impact in Sudanese public health especially during rainy season when the causative agent Salmonella enterica serovar Typhi possesses pan endemic patterns in most regions of Sudan - Khartoum.Objectives
The present study aims to assess the recent state of antibiotics susceptibility of Salmonella Typhi with special concern to multidrug resistance strains and predict the emergence of new resistant patterns and outbreaks.Methods
Salmonella Typhi strains were isolated and identified according to the guidelines of the International Standardization Organization and the World Health Organization. The antibiotics susceptibilities were tested using the recommendations of the Clinical Laboratories Standards Institute. Predictions of emerging resistant bacteria patterns and outbreaks in Sudan were done using logistic regression, forecasting linear equations and in silico simulations models.Results
A total of 124 antibiotics resistant Salmonella Typhi strains categorized in 12 average groups were isolated, different patterns of resistance statistically calculated by (y = ax ? b). Minimum bactericidal concentration’s predication of resistance was given the exponential trend (y = n ex) and the predictive coefficient R2 > 0 < 1 are approximately alike. It was assumed that resistant bacteria occurred with a constant rate of antibiotic doses during the whole experimental period. Thus, the number of sensitive bacteria decreases at the same rate as resistant occur following term to the modified predictive model which solved computationally.Conclusion
This study assesses the prediction of multi-drug resistance among S. Typhi isolates by applying low cost materials and simple statistical methods suitable for the most frequently used antibiotics as typhoid empirical therapy. Therefore, bacterial surveillance systems should be implemented to present data on the aetiology and current antimicrobial drug resistance patterns of community-acquired agents causing outbreaks.16.
Paul Wigley Scott Hulme Claire Powers Richard Beal Adrian Smith Paul Barrow 《BMC veterinary research》2005,1(1):1-6
Background
Salmonella enterica serovar Gallinarum (S. Gallinarum) is the causative agent of fowl typhoid, a severe systemic disease of chickens that results in high mortality amongst infected flocks. Due to its virulence, the immune response to S. Gallinarum is poorly characterised. In this study we have utilised infection by the live attenuated S. Gallinarum 9R vaccine strain in inbred chickens to characterise humoral, cellular and cytokine responses to systemic salmonellosis. 相似文献17.
Izabela Szulc-Kielbik Jakub Pawelczyk Michal Kielbik Laurent Kremer Jaroslaw Dziadek Magdalena Klink 《Microbial cell factories》2017,16(1):217
Background
Although mycobacterial glycolipids are among the first-line molecules involved in host–pathogen interactions, their contribution in virulence remains incomplete. Mycobacterium marinum is a waterborne pathogen of fish and other ectotherms, closely related to Mycobacterium tuberculosis. Since it causes tuberculosis-like systemic infection it is widely used as a model organism for studying the pathogenesis of tuberculosis. It is also an occasional opportunistic human pathogen. The M. marinum surface-exposed lipooligosaccharides (LOS) are immunogenic molecules that participate in the early interactions with macrophages and modulate the host immune system. Four major LOS species, designated LOS-I to LOS-IV, have been identified and characterized in M. marinum. Herein, we investigated the interactions between a panel of defined M. marinum LOS mutants that exhibited various degrees of truncation in the LOS structure, and human-derived THP-1 macrophages to address the potential of LOSs to act as pro- or avirulence factors.Results
A moderately truncated LOS structure did not interfere with M. marinum invasion. However, a deeper shortening of the LOS structure was associated with increased entry of M. marinum into host cells and increased elimination of the bacilli by the macrophages. These effects were dependent on Toll-like receptor 2.Conclusion
We provide the first evidence that LOSs inhibit the interaction between mycobacterial cell wall ligands and appropriate macrophage pattern recognition receptors, affecting uptake and elimination of the bacteria by host phagocytes.18.
Background
Mycobacterium smegmatis, a rapidly growing non-tuberculosis mycobacterium, is a good model for studying the pathogenesis of tuberculosis because of its genetic similarity to Mycobacterium tuberculosis (Mtb). Macrophages remove mycobacteria during an infection. Macrophage apoptosis is a host defense mechanism against intracellular bacteria. We have reported that endoplasmic reticulum (ER) stress is an important host defense mechanism against Mtb infection.Results
In this study, we found that M. smegmatis induced strong ER stress. M. smegmatis-induced reactive oxygen species (ROS) play a critical role in the induction of ER stress-mediated apoptosis. Pretreatment with an ROS scavenger suppressed M. smegmatis-induced ER stress. Elimination of ROS decreased the ER stress response and significantly increased the intracellular survival of M. smegmatis. Interestingly, inhibition of phagocytosis significantly decreased ROS synthesis, ER stress response induction, and cytokine production.Conclusions
Phagocytosis of M. smegmatis induces ROS production, leading to production of proinflammatory cytokines. Phagocytosis-induced ROS is associated with the M. smegmatis-mediated ER stress response in macrophages. Therefore, phagocytosis plays a critical role in the induction of ER stress-mediated apoptosis during mycobacterial infection.19.
Christa?Pfeifhofer-Obermair Karin?Albrecht-Schgoer Sebastian?Peer Manfred?Nairz Kerstin?Siegmund Victoria?Klepsch David?Haschka Nikolaus?Thuille Natascha?Hermann-Kleiter Thomas?Gruber Günter?Weiss Gottfried?Baier