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Foods (Basel, Switzerland) Jun 2022is a typical spoilage bacteria organism in seafood. The adhesion ability of three strains (HR-15, JR-18, HC-71) isolated from putrefied tilapia were evaluated by mucus...
is a typical spoilage bacteria organism in seafood. The adhesion ability of three strains (HR-15, JR-18, HC-71) isolated from putrefied tilapia were evaluated by mucus adhesion in vitro and intestinal adhesion in vivo. The results of the spoilage of the inoculated fish fillets and spoilage of the refrigerated fish both showed that the adhesion ability of was positively correlated with the spoilage ability. High-throughput sequencing and GC-MS results showed that with high adhesion ability also significantly changed the intestinal flora of fish, causing an increase in the intestinal bacteria such as , and , which then led to the increase in volatile substances such as low-grade aldehydes, alcohols, and ketones in the fish, serious fatty acid oxidation, and excitement of the fishy smell.
PubMed: 35804729
DOI: 10.3390/foods11131913 -
Virulence Dec 2022The genus consists of Gram-negative proteobacteria that are ubiquitously distributed in environment. As the members of this genus have rapidly increased within the past... (Review)
Review
The genus consists of Gram-negative proteobacteria that are ubiquitously distributed in environment. As the members of this genus have rapidly increased within the past decade, several species have become emerging pathogens worldwide, attracting the attention of the medical community. These species are also associated with severe community- and hospital-acquired infections. Patients infected with spp. had experiences of occupational or recreational exposure; meanwhile, the process of infection is complex and the pathogenicity is influenced by a variety of factors. Here, an exhaustive internet-based literature search was carried out in PUBMED using terms "," "," "" and "" to search literatures published between 1978 and June 2022. We provided a comprehensive review on the epidemiology, clinical features and pathogenicity of , which will contribute a better understanding of its clinical aetiology, and facilitate the timely diagnosis and effective treatment of infection for clinicians and public health professionals.
Topics: Cross Infection; Gram-Negative Bacterial Infections; Humans; Shewanella; Shewanella putrefaciens; Virulence
PubMed: 36065099
DOI: 10.1080/21505594.2022.2117831 -
Molecules (Basel, Switzerland) Jan 2021The demand for reduced chemical preservative usage is currently growing, and natural preservatives are being developed to protect seafood. With its excellent...
The demand for reduced chemical preservative usage is currently growing, and natural preservatives are being developed to protect seafood. With its excellent antibacterial properties, linalool has been utilized widely in industries. However, its antibacterial mechanisms remain poorly studied. Here, untargeted metabolomics was applied to explore the mechanism of cells treated with linalool. Results showed that linalool exhibited remarkable antibacterial activity against , with 1.5 µL/mL minimum inhibitory concentration (MIC). The growth of was suppressed completely at 1/2 MIC and 1 MIC levels. Linalool treatment reduced the membrane potential (MP); caused the leakage of alkaline phosphatase (AKP); and released the DNA, RNA, and proteins of , thus destroying the cell structure and expelling the cytoplasmic content. A total of 170 differential metabolites (DMs) were screened using metabolomics analysis, among which 81 species were upregulated and 89 species were downregulated after linalool treatment. These DMs are closely related to the tricarboxylic acid (TCA) cycle, glycolysis, amino acid metabolism, pantothenate and CoA biosynthesis, aminoacyl-tRNA biosynthesis, and glycerophospholipid metabolism. In addition, linalool substantially affected the activity of key enzymes, such as succinate dehydrogenase (SDH), pyruvate kinase (PK), ATPase, and respiratory chain dehydrogenase. The results provided some insights into the antibacterial mechanism of linalool against and are important for the development and application of linalool in seafood preservation.
Topics: Acyclic Monoterpenes; Anti-Bacterial Agents; Bacterial Proteins; Gene Expression Regulation, Bacterial; Gram-Negative Bacterial Infections; Insecticides; Metabolome; Shewanella putrefaciens
PubMed: 33466475
DOI: 10.3390/molecules26010245 -
Frontiers in Microbiology 2023is a model dissimilatory iron-reducing bacterium that can use Fe(III) and O as terminal electron acceptors. Consequently, it has the ability to influence both aerobic...
is a model dissimilatory iron-reducing bacterium that can use Fe(III) and O as terminal electron acceptors. Consequently, it has the ability to influence both aerobic and anaerobic groundwater systems, making it an ideal microorganism for improving our understanding of facultative anaerobes with iron-based metabolism. In this work, we examine the bioenergetics of O and Fe(III) reduction coupled to lactate oxidation in CN32. Bioenergetics were measured directly via isothermal calorimetry and by changes to the chemically defined growth medium. We performed these measurements from 25 to 36°C. Modeling metabolism with macrochemical equations allowed us to define a theoretical growth stoichiometry for the catabolic reaction of 1.00 O:lactate and 1.33 Fe(III):lactate that was consistent with the observed ratios of O:lactate (1.20 ± 0.23) and Fe(III):lactate (1.46 ± 0.15) consumption. Aerobic growth showed minimal variation with temperature and minimal variation in thermodynamic potentials of incubation. Fe(III)-based growth showed a strong temperature dependence. The Gibbs energy and enthalpy of incubation was minimized at ≥30°C. Energy partitioning modeling of Fe(III)-based calorimetric incubation data predicted that energy consumption for non-growth associate maintenance increases substantially above 30°C. This prediction agrees with the data at 33 and 35°C. These results suggest that the effects of temperature on CN32 are metabolism dependent. Gibbs energy of incubation above 30°C was 3-5 times more exergonic with Fe(III)-based growth than with aerobic growth. We compared data gathered in this study with predictions of microbial growth based on standard-state conditions and based on the thermodynamic efficiency of microbial growth. Quantifying the growth requirements of CN32 has advanced our understanding of the thermodynamic constraints of this dissimilatory iron-reducing bacterium.
PubMed: 37601367
DOI: 10.3389/fmicb.2023.1234598 -
Clinical Microbiology and Infection :... May 2005The occurrence of the two Shewanella species found in clinical specimens, Shewanella algae and Shewanella putrefaciens, correlates with the temperature and salinity of... (Comparative Study)
Comparative Study Review
The occurrence of the two Shewanella species found in clinical specimens, Shewanella algae and Shewanella putrefaciens, correlates with the temperature and salinity of seawater. This means that Shewanella infections occur in warm climates or during especially warm summers in temperate climates. The infections described most commonly involve ears, skin and soft tissue, with or without bacteraemia. Primary bacteraemia with a fulminant course is also seen in immunocompromised patients. Important differential characteristics between the two species include the ability of S. algae to produce mucoid colonies with beta-haemolysis on sheep blood agar, to grow at 42 degrees C and in NaCl 6% w/v, and to reduce nitrite, and an inability to produce acid from maltose, all of which are in contrast to the characteristics of S. putrefaciens. Automated identification systems fail to differentiate between S. algae and S. putrefaciens, as S. algae is not included in the databases of these systems. Presumably for this reason, most Shewanella infections reported during recent years have been attributed to S. putrefaciens. However, when extensive phenotypic characterisation is performed, most human infections are seen to be caused by S. algae. As the two species seem to have different pathogenic potential for humans, correct identification is important, and this is possible in routine clinical microbiology laboratories.
Topics: Animals; Anti-Bacterial Agents; Ear Diseases; Gram-Negative Bacterial Infections; Humans; Microbial Sensitivity Tests; Phenotype; Seawater; Shewanella; Shewanella putrefaciens; Skin Diseases, Bacterial; Temperature
PubMed: 15819859
DOI: 10.1111/j.1469-0691.2005.01108.x -
Frontiers in Cellular and Infection... 2022is a gramnegative, facultatively anaerobic, rod shaped bacterium. It belongs to the class of the and was first described in 1931. is part of the marine microflora and... (Review)
Review
is a gramnegative, facultatively anaerobic, rod shaped bacterium. It belongs to the class of the and was first described in 1931. is part of the marine microflora and especially present in moderate and warm climates. The bacterium is a rare oppurtonistic human pathogen associated mainly with intra-abdominal as well as skin and soft tissue infections. However, it has also been reported in association with more severe diseases such as pneumonia, intracerebral and ocular infections and endocarditis. In these cases the clinical courses are often associated with underlying, predisposing diseases and risk factors. For successful treatment of , a combination of appropriate local therapy, e.g. surgical treatment or drainage, and antibiotic therapy should be performed. Since multiple resistances to antibiotics are described, the results of the antimicrobial susceptibility testing must be considered for effective therapy as well. Furthermore, a main challenge in clinical practice is the accurate microbiological identification, and especially the correct differentiation between and . Under certain circumstances, -infections can have severe, sometimes even fatal consequences. Therefore, we decided to present the current state of knowledge as well as further aspects with regard to future diagnostics, therapy and research.
Topics: Humans; Shewanella putrefaciens; Gram-Negative Bacterial Infections; Anti-Bacterial Agents; Shewanella; Soft Tissue Infections
PubMed: 36817694
DOI: 10.3389/fcimb.2022.1033639 -
Frontiers in Microbiology 2022The diversity of the genus and their roles across a variety of ecological niches is largely unknown highlighting the phylogenetic diversity of these bacteria. From a...
The diversity of the genus and their roles across a variety of ecological niches is largely unknown highlighting the phylogenetic diversity of these bacteria. From a food safety perspective, species have been recognized as causative spoilage agents of vacuum-packed meat products. However, the genetic basis and metabolic pathways for the spoilage mechanism are yet to be explored due to the unavailability of relevant strains and genomic resources. In this study, whole-genome sequencing of 32 strains isolated from vacuum-packaged refrigerated spoiled lamb was performed to examine their roles in meat spoilage. Phylogenomic reconstruction revealed their genomic diversity with 28 spp. strains belonging to the same putative novel species, two strains (SM77 and SM91), NZRM825, and DSM 50426 (ATCC 8072) isolated from butter. Genome-wide clustering of orthologous gene families revealed functional groupings within the major cluster but also considerable plasticity across the different species. Pan-genome analysis revealed conserved occurrence of spoilage genes associated with sulfur and putrescine metabolism, while the complete set of trimethylamine metabolism genes was observed in only sp. SM74, SM77 and SM91 strains. Through comparative genomics, some variations were also identified pertaining to genes associated with adaptation to environmental cues such as temperature, osmotic, salt, oxidative, antimicrobial peptide, and drug resistance stresses. Here we provide a reference collection of draft genomes for subsequent species descriptions and future investigations into the molecular spoilage mechanisms for further applications in the meat industry.
PubMed: 36238595
DOI: 10.3389/fmicb.2022.976152 -
Molecules (Basel, Switzerland) Oct 2019ε-Polylysine (ε-PL) was studied for the growth inhibition of (). The minimal inhibitory concentration (MIC) of ε-PL against was measured by the broth dilution...
ε-Polylysine (ε-PL) was studied for the growth inhibition of (). The minimal inhibitory concentration (MIC) of ε-PL against was measured by the broth dilution method, while the membrane permeability and metabolism of were assessed after ε-PL treatment. Additionally, growth curves, the content of alkaline phosphatase (AKP), the electrical conductivity (EC), the UV absorbance and scanning electron microscope (SEM) data were used to study cellular morphology. The impact of ε-PL on cell metabolism was also investigated by different methods, such as enzyme activity (peroxidase [POD], catalase [CAT], succinodehydrogenase [SDH] and malic dehydrogenase [MDH]) and cell metabolic activity. The results showed that the MIC of ε-PL against was 1.0 mg/mL. When was treated with ε-PL, the growth of the bacteria was inhibited and the AKP content, electrical conductivity and UV absorbance were increased, which demonstrated that ε-PL could damage the cell structure. The enzyme activities of POD, CAT, SDH, and MDH in the bacterial solution with ε-PL were decreased compared to those in the ordinary bacterial solution. As the concentration of ε-PL was increased, the enzyme activity decreased further. The respiratory activity of was also inhibited by ε-PL. The results suggest that ε-PL acts on the cell membrane of , thereby increasing membrane permeability and inhibiting enzyme activity in relation to respiratory metabolism and cell metabolism. This leads to inhibition of cell growth, and eventually cell death.
Topics: Anti-Bacterial Agents; Cell Membrane; Energy Metabolism; Microbial Sensitivity Tests; Microbial Viability; Models, Molecular; Polylysine; Shewanella putrefaciens
PubMed: 31623152
DOI: 10.3390/molecules24203727 -
Journal of Food Science and Technology Sep 2018The aims of this study were to observe the antimicrobial effect and mechanism of cinnamon oil combined with gamma radiation on Gamma radiation increased the... (Review)
Review
The aims of this study were to observe the antimicrobial effect and mechanism of cinnamon oil combined with gamma radiation on Gamma radiation increased the antimicrobial activity of cinnamon oil, and the relative radiation sensitivity of gamma radiation on was increased by cinnamon oil. Gamma radiation significantly increased the changes of bacterial morphology, intra-adenosine 5'-triphosphate (intra-ATP) and extra-ATP concentrations and pH value of treated cinnamon oil. Although, gamma radiation used alone didn't damage the bacterial morphology and ATP concentrations significantly. Gamma radiation assisted cinnamon oil to damage the cell permeability and integrity of thus the combination of cinnamon oil and gamma radiation showed a better antimicrobial activity than used alone.
PubMed: 30150793
DOI: 10.1007/s13197-018-3297-5 -
Frontiers in Cellular and Infection... 2022is a Gram-negative bacterium that can cause seafood spoilage under low-temperature conditions. The bacterium easily forms biofilms to enhance its survival in...
is a Gram-negative bacterium that can cause seafood spoilage under low-temperature conditions. The bacterium easily forms biofilms to enhance its survival in challenging environments. Our previous research revealed that the biofilm formed by WS13 under the low temperature (4 °C) has larger biomass and tighter structure than at an optimum growth temperature (30 °C). In this study, comparative transcriptome analysis was further performed to get insights into the global-level of gene expression in the biofilm formed by WS13 under the refrigerating and optimal temperatures using Illumina RNA-Sequencing technique. The results revealed that a total of 761 genes were differentially expressed, of which 497 were significantly up-regulated and 264 were significantly down-regulated (<0.05). The qRT-PCR results of randomly selected differentially expressed genes (DEGs) confirmed the RNA sequencing results. Comparison of transcriptome data revealed 28 significantly changed metabolic pathways under the cold stress, including the down-regulated chemotaxis, and motility, and up-regulated tryptophan metabolism, histidine biosynthesis, and quorum sensing, which benefited the biofilm formation of WS13 under the adverse circumstance. This study provided useful data for better understanding of the biofilm formation of , and also laid a theoretical foundation for novel vaccine and drug targets against the severe spoilage bacterium under the cold stress.
Topics: Biofilms; Cold-Shock Response; Gene Expression Profiling; Shewanella putrefaciens; Transcriptome
PubMed: 35811677
DOI: 10.3389/fcimb.2022.851521