-
Frontiers in Microbiology 2023High hydrostatic pressure (HHP) regulated gene expression is one of the most commonly adopted strategies for microbial adaptation to the deep-sea environments....
High hydrostatic pressure (HHP) regulated gene expression is one of the most commonly adopted strategies for microbial adaptation to the deep-sea environments. Previously we showed that the HHP-inducible trimethylamine N-oxide (TMAO) reductase improves the pressure tolerance of deep-sea strain QY27. Here, we investigated the molecular mechanism of HHP-responsive regulation of TMAO reductase TorA. By constructing and deletion mutants, we demonstrated that the two-component regulator TorR and sensor TorS are responsible for the HHP-responsive regulation of . Unlike known HHP-responsive regulatory system, the abundance of and was not affected by HHP. Complementation of the Δ mutant with TorS altered at conserved phosphorylation sites revealed that the three sites were indispensable for substrate-induced regulation, but only the histidine located in the alternative transmitter domain was involved in pressure-responsive regulation. Taken together, we demonstrated that the induction of TMAO reductase by HHP is mediated through the TorRS system and proposed a bifurcation of signal transduction in pressure-responsive regulation from the substrate-induction. This work provides novel knowledge of the pressure regulated gene expression and will promote the understanding of the microbial adaptation to the deep-sea HHP environment.
PubMed: 38029070
DOI: 10.3389/fmicb.2023.1291578 -
Complete genomic sequence of strain IDH5335 isolated from a patient with diarrhea in Kolkata, India.Microbiology Resource Announcements Dec 2023We isolated a strain (IDH5335) from a stool sample collected from a patient with diarrhea. In this announcement, we report the complete genomic sequence of this...
We isolated a strain (IDH5335) from a stool sample collected from a patient with diarrhea. In this announcement, we report the complete genomic sequence of this organism, which was obtained by combining Illumina and Oxford Nanopore sequencing data.
PubMed: 37943041
DOI: 10.1128/MRA.00707-23 -
Journal of Global Antimicrobial... Dec 2023
Topics: Genomic Islands; Salmonella; beta-Lactamases
PubMed: 37748579
DOI: 10.1016/j.jgar.2023.09.014 -
Chembiochem : a European Journal of... Dec 2023Furan-based amines are highly valuable compounds which can be directly obtained via reductive amination from easily accessible furfural, 5-(hydroxymethyl)furfural (HMF)...
Furan-based amines are highly valuable compounds which can be directly obtained via reductive amination from easily accessible furfural, 5-(hydroxymethyl)furfural (HMF) and 2,5-diformylfuran (DFF). Herein the biocatalytic amination of these carbonyl derivatives is disclosed using amine transaminases (ATAs) and isopropylamine (IPA) as amine donors. Among the different biocatalysts tested, the ones from Chromobacterium violaceum (Cv-TA), Arthrobacter citreus (ArS-TA), and variants from Arthrobacter sp. (ArRmut11-TA) and Vibrio fluvialis (Vf-mut-TA), afforded high levels of product formation (>80 %) at 100-200 mM aldehyde concentration. The transformations were studied in terms of enzyme and IPA loading. The pH influence was found as a key factor and attributed to the imine/aldehyde equilibrium that can arise from the high reactivity of the carbonyl substrates with a nucleophilic amine such as IPA.
Topics: Aldehydes; Amines; Furans; Hydrogen-Ion Concentration
PubMed: 37737725
DOI: 10.1002/cbic.202300514 -
Cureus Jul 2023is a pathogenic Gram-negative bacillus typically resulting in gastroenteritis in humans. It has recently been identified as a growing concern for public health. The...
is a pathogenic Gram-negative bacillus typically resulting in gastroenteritis in humans. It has recently been identified as a growing concern for public health. The case presented is an uncommon case of causing bacteremia, as well as hemorrhagic skin lesions. Other reported cases have also highlighted unexpected manifestations, such as cerebritis, bacterial peritonitis, and otitis externa. These atypical presentations can happen in immunocompromised individuals. There are no established guidelines currently for the treatment of bacteremia. This case presents bacteremia that improved with doxycycline without the need for incision and drainage of the patient's lower extremity lesions.
PubMed: 37521591
DOI: 10.7759/cureus.42612 -
Chembiochem : a European Journal of... Oct 2023An enzyme cascade was established previously consisting of a recycling system with an l-amino acid oxidase (hcLAAO4) and a catalase (hCAT) for different α-keto acid...
An enzyme cascade was established previously consisting of a recycling system with an l-amino acid oxidase (hcLAAO4) and a catalase (hCAT) for different α-keto acid co-substrates of (S)-selective amine transaminases (ATAs) in kinetic resolutions of racemic amines. Only 1 mol % of the co-substrate was required and l-amino acids instead of α-keto acids could be applied. However, soluble enzymes cannot be reused easily. Immobilization of hcLAAO4, hCAT and the (S)-selective ATA from Vibrio fluvialis (ATA-Vfl) was addressed here. Immobilization of the enzymes together rather than on separate beads showed higher reaction rates most likely due to fast co-substrate channeling between ATA-Vfl and hcLAAO4 due to their close proximity. Co-immobilization allowed further reduction of the co-substrate amount to 0.1 mol % most likely due to a more efficient H O -removal caused by the stabilized hCAT and its proximity to hcLAAO4. Finally, the co-immobilized enzyme cascade was reused in 3 cycles of preparative kinetic resolutions to produce (R)-1-PEA with high enantiomeric purity (97.3 %ee). Further recycling was inefficient due to the instability of ATA-Vfl, while hcLAAO4 and hCAT revealed high stability. An engineered ATA-Vfl-8M was used in the co-immobilized enzyme cascade to produce (R)-1-(3-ethoxy-4-methoxyphenyl)-2-(methylsulfonyl)ethanamine, an apremilast-intermediate, with a 1,000 fold lower input of the co-substrate.
Topics: Amines; Transaminases; L-Amino Acid Oxidase; Enzymes, Immobilized; Catalase; Keto Acids
PubMed: 37368451
DOI: 10.1002/cbic.202300425 -
Journal of Tropical Medicine 2023The noncholera spp. which cause vibriosis are abundantly found in our water ecosystem. These bacteria could negatively affect both humans and animals. To date, there is...
BACKGROUND
The noncholera spp. which cause vibriosis are abundantly found in our water ecosystem. These bacteria could negatively affect both humans and animals. To date, there is a paucity of information available on the existence and pathogenicity of this particular noncholera spp. in Malaysia in comparison to their counterpart, .
METHODS
In this study, we extracted retrospective data from Malaysian surveillance database. Analysis was carried out using WHONET software focusing noncholera spp. including , , , , (), , , and .
RESULTS
Here, we report the first distribution and prevalence of these species isolated in Malaysia together with the antibiotic sensitivity profile based on the species. We found that is the predominant species isolated in Malaysia. Noticeably, across the study period, is becoming more prevalent, as compared to . In addition, this study also reports the first isolation of pathogenic from stool in Malaysia.
CONCLUSION
These data represent an important step toward understanding the potential emergence of noncholera spp. outbreaks.
PubMed: 37274080
DOI: 10.1155/2023/2716789 -
Archives of Microbiology Apr 2023The type VI secretion system (T6SS) is important for interbacterial competition and virulence in Vibrio species. It is generally agreed that T6SS provides a fitness...
The type VI secretion system (T6SS) is important for interbacterial competition and virulence in Vibrio species. It is generally agreed that T6SS provides a fitness advantage to Vibrios. Some Vibrio species possess one, while others possess two T6SSs. Even within the same Vibrio species, different strains can harbor a variable number of T6SSs. Such is the case in V. fluvialis, an opportunistic human pathogen, that some V. fluvialis strains do not harbor T6SS1. This study found that Amphritea, Marinomonas, Marinobacterium, Vibrio, Photobacterium, and Oceanospirillum species have genes encoding V. fluvialis T6SS1 homologs. The cladogram of T6SS1 genes suggested that these genes appeared to be horizontally acquired by V. fluvialis, V. furnissii, and some other Vibrio species, when compared with the species tree. Codon insertions, codon deletions, nonsense mutations, and the insertion sequence are found in many genes, such as clpV1, tssL1, and tssF1, which encode structure components of T6SS1 in V. furnissii and V. fluvialis. Codon deletion events are more common than codon insertion, insertion sequence disruption, and nonsense mutation events in genes that encode components of T6SS1. Similarly, codon insertions and codon deletions are found in genes relevant to T6SS2, including tssM2, vgrG2 and vasH, in V. furnissii and V. fluvialis. These mutations are likely to disable the functions of T6SSs. Our findings indicate that T6SS may have a fitness disadvantage in V. furnissii and V. fluvialis, and the loss of function in T6SS may help these Vibrio species to survive under certain conditions.
Topics: Humans; DNA Transposable Elements; Vibrio; Genomics; Mutation
PubMed: 37101014
DOI: 10.1007/s00203-023-03557-1 -
Foods (Basel, Switzerland) Mar 2023Previous research has shown that freshwater edible fish imported into Australia are not compliant with Australian importation guidelines and as a result may be high risk...
Previous research has shown that freshwater edible fish imported into Australia are not compliant with Australian importation guidelines and as a result may be high risk for bacterial contamination. In the present study, the outer surface of imported freshwater fish were swabbed, cultured, confirmatory tests performed and antimicrobial patterns investigated. Channidae fish (Sp. A/n = 66) were contaminated with zoonotic sp./ (n = 1/66) and other bacteria implicated in cases of opportunistic human infection, these being sp. (including . and (n = 34/66)); sp. (n = 32/66); (n = 27/66) and (n = 3/66). Pangasiidae fish (Species B/n = 47) were contaminated with zoonotic (n = 10/47); sp. (n = 6/47) and environmental bacteria sp. (n = 3/47). One sample was resistant to all antimicrobials tested and is considered to be Methicillin Resistant . Mud, natural diet, or vegetation identified in Sp. A fish/or packaging were significantly associated with the presence of spp. The study also showed that visibly clean fish (Sp. B) may harbour zoonotic bacteria and that certain types of bacteria are common to fish groups, preparations, and contaminants. Further investigations are required to support the development of appropriate food safety recommendations in Australia.
PubMed: 36981215
DOI: 10.3390/foods12061288 -
Fish & Shellfish Immunology May 2023In recent years, the widespread use of antibiotics in intensive grouper mariculture has resulted in the ineffectiveness of antibiotic treatment, leading to an increasing...
Screening of host gut-derived probiotics and effects of feeding probiotics on growth, immunity, and antioxidant enzyme activity of hybrid grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂).
In recent years, the widespread use of antibiotics in intensive grouper mariculture has resulted in the ineffectiveness of antibiotic treatment, leading to an increasing incidence of diseases caused by bacteria, viruses, and parasites, causing serious economic losses. Hence, it is crucial to develop alternative strategies to antibiotics for healthy and sustainable development of the mariculture industry. Here, we aimed to screen host gut-derived probiotics and evaluate its effects on growth and immunity of grouper. In this study, 43 bacterial strains were isolated from the intestine of the hybrid grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂), and a potential probiotic strain G1-26, which can efficiently secrete amylase, protease, and lipase, was obtained using different screening mediums. Based on 16S rDNA sequencing, the potential probiotic strain G1-26 was identified as Vibrio fluvialis. The results of a biological characteristic evaluation showed that V. fluvialis G1-26 could grow at 25-45 °C, pH 5.5-7.5, salinity 10-40, and bile salt concentration 0-0.030%, and produce amylase, lipase, and protease under different culture conditions. Additionally, V. fluvialis G1-26 is sensitive to many antibiotics and does not exhibit aquatic biotoxicity. Subsequently, hybrid groupers were fed diets containing V. fluvialis G1-26 at different concentrations (0, 10, 10, and 10 CFU/g) for 60 d. The results showed that V. fluvialis G1-26 at 10 CFU/g did not significantly affect the growth performance of the hybrid grouper (P > 0.05). V. fluvialis G1-26 supplementation at 10 and 10 CFU/g significantly promoted the relative expression of immune-related genes in hybrid groupers (TLR3, TLR5, IL-1β, IL-8, IL-10, CTL, LysC, TNF-2, and MHC-2) and improved the activities of alkaline phosphatase, acid phosphatase, total superoxide dismutase, and total protein in the liver. In conclusion, V. fluvialis G1-26, a potential probiotic strain isolated from the intestine of the hybrid grouper, can be used as an effective immunopotentiator at an optimal dose of 10 CFU/g diet. Our results provide a scientific basis for the development and utilization of probiotics in the grouper mariculture industry.
Topics: Animals; Antioxidants; Bass; Diet; Probiotics; Peptide Hydrolases; Amylases; Lipase; Animal Feed
PubMed: 36966895
DOI: 10.1016/j.fsi.2023.108700