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Journal of Agricultural and Food... Aug 2022is one of the major food-spoilage bacteria and can survive under cold stress. In this study, the membrane composition, membrane permeability, and energy transduction of...
is one of the major food-spoilage bacteria and can survive under cold stress. In this study, the membrane composition, membrane permeability, and energy transduction of XY27 cultured at 4 and 30 °C were examined comparatively by flow cytometry combined with liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. The Na/KATPase activity, alkaline phosphatase and ATPase activity, fluorescence intensity, and cell viability in XY27 increased with the decrease in cultivation temperature. The polyunsaturated fatty acid and monounsaturated fatty acids have a higher content in XY27 cultured at 4 °C compared to that cultured at 30 °C, in which the contents of methyl palmitoleate, methyl myristoleate, and methyl oleate increased dramatically with decreasing temperature. Comparative proteomics analysis revealed that 31 proteins were downregulated and 4 proteins were upregulated, in which catalase-peroxidase 1 and cold shock proteins as biomarker proteins could effectively control during cold adaptation.
Topics: Acinetobacter; Adenosine Triphosphatases; Animals; Biomarkers; Membrane Proteins; Proteomics; Tuna
PubMed: 35919963
DOI: 10.1021/acs.jafc.2c03303 -
Microbiology Spectrum Aug 2022Several studies have suggested a role for gut mucosa-associated microbiota in the development of obesity, but the mechanisms involved are poorly defined. Here, the...
Several studies have suggested a role for gut mucosa-associated microbiota in the development of obesity, but the mechanisms involved are poorly defined. Here, the impact of the gut mucosa-associated microbiota on obesity and related metabolic disorders was evaluated in a metabolic syndrome (MetS) porcine model. Body composition was determined among male Wuzhishan minipigs consuming a high-energy diet (HED) and compared to that of those consuming a normal diet (ND), and gut segments (duodenum, jejunum, ileum, cecum, colon, and rectum) were sampled for paired analysis of mucosa-associated microbiota and transcriptome signatures with 16S rRNA gene and RNA sequencing, respectively. Our data indicated that long-term HED feeding significantly increased body weight and visceral fat deposition and aggravated metabolic disorders. Specially, HED feeding induced mucosa-associated microbiota dysbiosis and selectively increased the abundance of the families , , and in the upper intestine. The association analysis indicated that specific bacteria play key roles in adiposity, e.g., Lactobacillus johnsonii in the duodenum, Actinobacillus indolicus in the jejunum, Acinetobacter johnsonii in the ileum, Clostridium butyricum in the cecum, Haemophilus parasuis in the colon, and bacterium NLAEzlP808, , and sp. JNUH029 in the rectum. Transcriptome data further revealed intestinal lipid metabolism and immune dysfunction in the MetS individuals, which may be associated with obesity and related metabolic disorders. Our results indicated that gut mucosa-associated microbiota dysbiosis has the potential to exacerbate obesity, partially through modulating systemic inflammatory responses. Obesity is a major risk factor for metabolic syndrome, which is the most common cause of death worldwide, especially in developed countries. The link between obesity and gut mucosa-associated microbiota is unclear due to challenges associated with the collection of intestinal samples from humans. The current report provides the first insight into obesity-microbiome-gut immunity connections in a metabolic syndrome (MetS) porcine model. The present results show that dysbiosis of mucosal microbiota along the entire digestive tract play a critical role in the proinflammatory response in the host-microbial metabolism axis, resulting in obesity and related metabolic disorders in the MetS model.
Topics: Animals; Bacteria; Dysbiosis; Humans; Male; Metabolic Syndrome; Microbiota; Mucous Membrane; Obesity; RNA, Ribosomal, 16S; Swine; Swine, Miniature; Transcriptome
PubMed: 35862956
DOI: 10.1128/spectrum.00717-22 -
Journal of Hazardous Materials Aug 2022Soil serves as a major reservoir of both antibiotic resistance genes (ARGs) and microplastics. However, the characteristics of the antibiotic resistome in the soil...
Soil serves as a major reservoir of both antibiotic resistance genes (ARGs) and microplastics. However, the characteristics of the antibiotic resistome in the soil plastisphere remain largely unknown. In this study, we used metagenomic approaches to reveal the changing patterns of ARGs and the bacterial community and their associations in response to three types of microplastics (light density polyethylene, LDPE; polypropylene, PP; polystyrene, PS) using particles 550 µm or 75 µm in diameter. The total ARG abundances significantly increased in the plastisphere and varied across plastic types. The LDPE plastisphere had the highest ARG total abundance and lowest Shannon diversity index, indicating that this plastic had the most severe negative impact on soil bacterial diversity. The PP plastisphere contained higher relative abundances of the pathogenic bacteria Acinetobacter johnsonii and Escherichia coli, demonstrating the higher pathogenic risk of the microbial communities enriched in the plastisphere. Specifically, multidrug resistance genes (ceoB and MuxB) co-existed with more than four microbial taxa, increasing the potential risk of ARG spread in pathogenic bacteria. These findings implied that the plastisphere acts as a hotspot for acquiring and spreading antibiotic resistance and may have long-term negative effects on the soil ecosystem and human health.
Topics: Anti-Bacterial Agents; Bacteria; Drug Resistance, Microbial; Genes, Bacterial; Humans; Microbiota; Microplastics; Plastics; Polyethylene; Soil
PubMed: 35739766
DOI: 10.1016/j.jhazmat.2022.129247 -
Environmental Research Oct 2022Most bacteria in the natural environment have a biofilm mode of life, which is intrinsically tolerant to antibiotics. While until now, the knowledge of biofilm formation...
Most bacteria in the natural environment have a biofilm mode of life, which is intrinsically tolerant to antibiotics. While until now, the knowledge of biofilm formation by Acinetobacter johnsonii is not well understood. In this study, the characteristics and the effect of a sub-inhibitory concentration of antibiotic on A. johnsonii biofilm and planktonic cells were determined. We discovered a positive relationship between biofilm formation and tetracycline resistance, and biofilms rapidly evolve resistance to tetracycline they are treated with. Persister cells commonly exist in both planktonic and biofilm cells, with a higher frequency in the latter. Further transcriptomic analysis speculates that the overexpression of multidrug resistance genes and stress genes were mainly answered to sub lethal concentration of tetracycline in planktonic cells, and the lower metabolic levels after biofilm formation result in high resistance level of biofilm cells to tetracycline. Altogether, these data suggest that A. johnsonii can adjust its phenotype when grown as biofilm and change its metabolism under antibiotic stress, and provide implications for subsequent biofilm control.
Topics: Acinetobacter; Anti-Bacterial Agents; Biofilms; Microbial Sensitivity Tests; Plankton; Tetracycline; Transcriptome
PubMed: 35718162
DOI: 10.1016/j.envres.2022.113714 -
Journal of Applied Microbiology Sep 2022The role of a Acinetobacter johnsonii strain, isolated from a soil sample, in the biotransformation of bile acids (BAs) was already described but the enzymes responsible...
AIMS
The role of a Acinetobacter johnsonii strain, isolated from a soil sample, in the biotransformation of bile acids (BAs) was already described but the enzymes responsible for these transformations were only partially purified and molecularly characterized.
METHODS AND RESULTS
This study describes the use of hybrid de novo assemblies, that combine long-read Oxford Nanopore and short-read Illumina sequencing strategies, to reconstruct the entire genome of A. johnsonii ICE_NC strain and to identify the coding region for a 12α-hydroxysteroid dehydrogenase (12α-HSDH), involved in BAs metabolism. The de novo assembly of the A. johnsonii ICE_NC genome was generated using Canu and Unicycler, both strategies yielded a circular chromosome of about 3.6 Mb and one 117 kb long plasmid. Gene annotation was performed on the final assemblies and the gene for 12α-HSDH was detected on the plasmid.
CONCLUSIONS
Our findings illustrate the added value of long read sequencing in addressing the challenges of whole genome characterization and plasmid reconstruction in bacteria. These approaches also allowed the identification of the A. johnsonii ICE_NC gene for the 12α-HSDH enzyme, whose activity was confirmed at the biochemical level.
SIGNIFICANCE AND IMPACT OR THE STUDY
At present, this is the first report on the characterization of a 12α-HSDH gene in an A. johnsonii strain able to biotransform cholic acid into ursodeoxycholic acid, a promising therapeutic agent for several diseases.
Topics: Acinetobacter; Bile Acids and Salts; Genome, Bacterial; High-Throughput Nucleotide Sequencing; Hydroxysteroid Dehydrogenases
PubMed: 35686660
DOI: 10.1111/jam.15657 -
Frontiers in Microbiology 2022Salt-tolerant plant growth-promoting rhizobacteria (PGPR) can improve soil enzyme activities, which are indicators of the biological health of the soil, and can overcome...
Salt-tolerant plant growth-promoting rhizobacteria (PGPR) can improve soil enzyme activities, which are indicators of the biological health of the soil, and can overcome the nutritional imbalance in plants. A pot trial was executed to evaluate the effect of inoculation of different salt-tolerant PGPR strains in improving soil enzyme activities. Three different salinity levels (original, 5, and 10 dS m) were used and maize seeds were coated with the freshly prepared inocula of ten different PGPR strains. Among different strains, inoculation of SUA-14 () caused a maximum increment in urease (1.58-fold), acid (1.38-fold), and alkaline phosphatase (3.04-fold) and dehydrogenase (72%) activities as compared to their respective uninoculated control. Acid phosphatase activities were found to be positively correlated with P contents in maize straw ( = 0.96) and grains ( = 0.94). Similarly, a positive correlation was found between alkaline phosphatase activities and P contents in straw ( = 0.77) and grains ( = 0.75). In addition, urease activities also exhibited positive correlation with N contents in maize straw ( = 0.92) and grains ( = 0.91). Moreover, inoculation of caused a significant decline in catalase (39%), superoxide dismutase (26%) activities, and malondialdehyde contents (27%). The PGPR inoculation improved the soil's biological health and increased the uptake of essential nutrients and conferred salinity tolerance in maize. We conclude that the inoculation of salt-tolerant PGPR improves soil enzyme activities and soil biological health, overcomes nutritional imbalance, and thereby improves nutrient acquisition by the plant under salt stress.
PubMed: 35633670
DOI: 10.3389/fmicb.2022.901865 -
Foods (Basel, Switzerland) Mar 2022This study aimed to investigate the antibacterial properties and mechanisms of a high-voltage static electric field (HVEF) in which were assessed from the perspective...
This study aimed to investigate the antibacterial properties and mechanisms of a high-voltage static electric field (HVEF) in which were assessed from the perspective of biochemical properties and stress-related genes. The time/voltage-kill assays and growth curves showed that an HVEF decreased the number of bacteria and OD600 values. In addition, HVEF treatment caused the leakage of cell contents (nucleic acids and proteins), increased the electrical conductivity and amounts of reactive oxygen substances (ROS) (16.88 fold), and decreased the activity of Na+ K+-ATPase in . Moreover, the changes in the expression levels of genes involved in oxidative stress and DNA damage in the treated cells suggested that HVEF treatment could induce oxidative stress and DNA sub-damage. This study will provide useful information for the development and application of an HVEF in food safety.
PubMed: 35407042
DOI: 10.3390/foods11070955 -
Food Chemistry Sep 2022Chilled surimi has become increasingly popular owing to its superior texture and freshness. In this study, changes in the microbiota and gel properties during chilled...
Chilled surimi has become increasingly popular owing to its superior texture and freshness. In this study, changes in the microbiota and gel properties during chilled surimi storage, and the contributions of dominant bacteria to the physicochemical properties of chilled surimi were investigated. The results showed that Pseudomonas gessardii, Aeromonas media, and Acinetobacter johnsonii were the dominant bacteria during chilled surimi storage. P. gessardii was the key bacteria that degraded protein in the process of surimi spoilage, which led to high total volatile base nitrogen (TVB-N), trichloroacetic acid (TCA)-soluble peptides as well as poor gel properties. Both P. gessardii and A. media were high putrescine producers, whereas only A. media produced cadaverine. In this study, spoilage microorganisms in chilled surimi were investigated for the first time, and it was found that P. gessardii had the greatest influence on surimi quality, which provides a research basis for in-depth study on the mechanism of microbial spoilage and the preservation of chilled surimi.
Topics: Animals; Cadaverine; Carps; Food Storage; Microbiota; Nitrogen; Putrescine
PubMed: 35405557
DOI: 10.1016/j.foodchem.2022.132847 -
Microbiology Resource Announcements Apr 2022Here, we report the complete genome sequence of a rare pigment-producing strain of Acinetobacter johnsonii. The genome consists of a 3,360,823-bp circular chromosome...
Here, we report the complete genome sequence of a rare pigment-producing strain of Acinetobacter johnsonii. The genome consists of a 3,360,823-bp circular chromosome (G+C content, 41.56%) and an 8,887-bp plasmid (G+C content, 33.71%). It possesses 3,038 coding gene sequences, 19 rRNA genes, 87 tRNA genes, and 4 noncoding RNA (ncRNA) genes.
PubMed: 35377178
DOI: 10.1128/mra.00025-22 -
Klinicka Mikrobiologie a Infekcni... Sep 2021One of the most common cancers is esophageal carcinoma. The basic therapeutic approach is esophagectomy, one of the most extensive procedures in general surgery,...
One of the most common cancers is esophageal carcinoma. The basic therapeutic approach is esophagectomy, one of the most extensive procedures in general surgery, potentially leading to serious postoperative complications, in particular respiratory complications. The objective was clinical and microbiological characterization of patients after the surgical removal of the esophagus for carcinoma. In 2020, a total of 14 patients underwent the surgery. Respiratory complications occurred in 57 % of them, with pneumonia leading to respiratory failure and acute respiratory distress syndrome being noted in 21 %. The identified bacterial pathogens were strains of Acinetobacter johnsonii, Enterobacter cloacae, Serratia marcescens, Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Enterococcus faecium. In one case, the patient's condition was complicated by fungal infection caused by Candida krusei. The study results warrant the need for close collaboration between the physician caring for a particular patient and a microbiologist that must be continuous and based on daily assessment of both microbiology test results and the patient's clinical condition.
Topics: Enterococcus faecium; Esophageal Neoplasms; Humans; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Stenotrophomonas maltophilia
PubMed: 35170744
DOI: No ID Found