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Clinical Microbiology and Infection :... Jun 2022To characterize Alcaligenes faecalis metallo-β-lactamase (MBL) AFM-2 and AFM-3 from clinical Pseudomonas aeruginosa isolates NDTH10366, NDTH9845 and WTJH17.
OBJECTIVES
To characterize Alcaligenes faecalis metallo-β-lactamase (MBL) AFM-2 and AFM-3 from clinical Pseudomonas aeruginosa isolates NDTH10366, NDTH9845 and WTJH17.
METHODS
Clinical isolates were whole-genome sequenced using the Illumina and Oxford Nanopore platforms. MICs of clinical isolates and transformants containing MBL genes were determined using broth microdilution methods. Kinetic parameters of purified AFM and NDM-1 were measured using a spectrophotometer. The AFM structure was modelled with SWISS-MODEL.
RESULTS
NDTH10366 and NDTH9845 were extensively drug-resistant (XDR) isolates carrying bla and multiple copies of bla, whereas WTJH17 was an XDR isolate carrying bla. The plasmid-borne bla and bla genes are associated with a novel ISCR element, ISCR29. AFM-2 and AFM-3, differing from AFM-1 by one amino acid substitution each, shared 86.2% and 86.6% amino acid sequence identity with NDM-1, respectively. Phylogenetic analysis confirmed the close relationship between AFM and NDM. Expression of AFM and NDM-1 under their native promoters in DH5α and PAO1 led to elevated MICs for all tested β-lactams except aztreonam. Comparable catalytic abilities were observed for AFM and NDM-1 when hydrolysing nitrocefin, cefepime, imipenem and biapenem, whereas for other tested β-lactams AFM displayed weaker enzymatic activities. Modelling AFM structure revealed a characteristic αβ/βα fold with two zinc-binding active sites.
CONCLUSIONS
AFM from clinical P. aeruginosa isolates demonstrated β-lactamase activity comparable to NDM-1. Co-carriage of bla and bla renders clinical P. aeruginosa isolates non-susceptible to all antipseudomonal β-lactams. The association of bla genes with translocatable genetic elements and plasmids highlights their concerning potential for dissemination.
Topics: Alcaligenes faecalis; Anti-Bacterial Agents; Humans; Microbial Sensitivity Tests; Phylogeny; Pseudomonas Infections; Pseudomonas aeruginosa; beta-Lactamases; beta-Lactams
PubMed: 34826621
DOI: 10.1016/j.cmi.2021.11.012 -
International Immunopharmacology Apr 2023Alcaligenes faecalis was previously identified as an intestinal lymphoid tissue-resident commensal bacteria, and our subsequent studies showed that lipopolysaccharide...
Alcaligenes faecalis was previously identified as an intestinal lymphoid tissue-resident commensal bacteria, and our subsequent studies showed that lipopolysaccharide and its core active element (i.e., lipid A) have a potent adjuvant activity to promote preferentially antigen-specific Th17 response and antibody production. Here, we compared A. faecalis lipid A (ALA) with monophosphoryl lipid A, a licensed lipid A-based adjuvant, to elucidate the immunological mechanism underlying the adjuvant properties of ALA. Compared with monophosphoryl lipid A, ALA induced higher levels of MHC class II molecules and costimulatory CD40, CD80, and CD86 on dendritic cells (DCs), which in turn resulted in strong T cell activation. Moreover, ALA more effectively promoted the production of IL-6 and IL-23 from DCs than did monophosphoryl lipid A, thus leading to preferential induction of Th17 and Th1 cells. As underlying mechanisms, we found that the ALA-TLR4 axis stimulated both MyD88- and TRIF-mediated signaling pathways, whereas monophosphoryl lipid A was biased toward TRIF signaling. These findings revealed the effects of ALA on DCs and T cells and its induction pattern on signaling pathways.
Topics: Lipid A; Myeloid Differentiation Factor 88; Toll-Like Receptor 4; Antigen Presentation; Alcaligenes; Signal Transduction; Adjuvants, Immunologic; Cell Differentiation; Adaptor Proteins, Vesicular Transport; Dendritic Cells
PubMed: 36806039
DOI: 10.1016/j.intimp.2023.109852 -
Pediatric Emergency Care Jul 2017Alcaligenes faecalis is a gram-negative organism that is commonly found in the environment and may also be a part of normal fecal flora in humans. Although various... (Review)
Review
Alcaligenes faecalis is a gram-negative organism that is commonly found in the environment and may also be a part of normal fecal flora in humans. Although various infections with this bacteria have been described in the pediatric population, it has not been previously identified in infections as the pathogen after a dog bite. A case of a 19-month-old boy is presented with a cellulitis secondary to a dog bite, which failed oral antibiotic therapy, and progressed to worsening fever and swelling. The patient ultimately required hospitalization, intravenous antibiotics, and incision and drainage. The wound culture grew A. faecalis, whose identity was confirmed through recombinant DNA sequence analysis. Although it has been identified in cat bite wounds, A. faecalis has not been cited in the literature before in an infection after a dog bite.
Topics: Alcaligenes faecalis; Animals; Anti-Bacterial Agents; Bites and Stings; Cellulitis; Dogs; Humans; Infant; Male
PubMed: 26760830
DOI: 10.1097/PEC.0000000000000645 -
Environmental Science and Pollution... Oct 2022EPS (extracellular polymeric substance) production is a self-protection mechanism by which microorganisms slow or eliminate adverse effects in unfavorable environments....
EPS (extracellular polymeric substance) production is a self-protection mechanism by which microorganisms slow or eliminate adverse effects in unfavorable environments. In this study, Pseudomonas aeruginosa and Alcaligenes faecalis were selected to explore changes in EPS components, especially protein components, under stress caused by different concentrations of Cd(II). The results showed that the protein content in EPS was the highest. The two strains achieved maximum EPS production levels of 109.17 and 214.96 mg/g VSS at Cd(II) stress concentrations of 20 and 50 mg/L, which were increased by 52.07% and 409.69% compared with the levels exhibited before stress, respectively. The protein content correlated very well with data from adsorption experiments. Furthermore, FTIR, 3D-EEM, and XPS results illustrated that after Cd(II) stress, C-N, C=O/-COOH, and R-NO moieties were formed in substantial quantities, and the stress effects of Pseudomonas aeruginosa were significantly higher than those of Alcaligenes faecalis. The results of this study showed that addition of Cd(NO) effectively regulated the components of EPS, especially the protein content, and improved the adsorption capacity, which has application prospects for prevention and control of heavy metals.
Topics: Adsorption; Alcaligenes faecalis; Cadmium; Extracellular Polymeric Substance Matrix; Metals, Heavy; Nitrogen Dioxide; Pseudomonas aeruginosa
PubMed: 35665452
DOI: 10.1007/s11356-022-21114-z -
Journal of Hazardous Materials Jul 2023Phosphorus-rich biochar (PBC) has been extensively studied due to its significant adsorption effect on U(VI). However, the release of phosphorus from PBC into solution...
Phosphorus-rich biochar (PBC) has been extensively studied due to its significant adsorption effect on U(VI). However, the release of phosphorus from PBC into solution decreases its adsorption performance and reusability and causes phosphorus pollution of water. In this study, Alcaligenes faecalis (A. faecalis) was loaded on PBC to produce a novel biocomposite (A/PBC). After adsorption equilibrium, phosphorus released into solution from PBC was 2.32 mg/L, while it decreased to 0.34 mg/L from A/PBC (p < 0.05). The U(VI) removal ratio of A/PBC reached nearly 100%, which is 13.08% higher than that of PBC (p < 0.05), and it decreased only by 1.98% after 5 cycles. When preparing A/PBC, A. faecalis converted soluble phosphate into insoluble metaphosphate minerals and extracellular polymeric substances (EPS). And A. faecalis cells accumulated through these metabolites and formed biofilm attached to the PBC surface. The adsorption of metal cations on phosphate further contributed to phosphorus fixation in the biofilm. During U(VI) adsorption by A/PBC, A. faecalis synthesize EPS and metaphosphate minerals by using the internal components of PBC, thus increasing the abundance of acidic functional groups and promoting U(VI) adsorption. Hence, A/PBC can be a green and sustainable material for U(VI) removal from wastewater.
Topics: Phosphorus; Wastewater; Alcaligenes faecalis; Adsorption; Minerals; Charcoal; Phosphates; Uranium; Kinetics
PubMed: 37156195
DOI: 10.1016/j.jhazmat.2023.131484 -
Toxins Aug 2022Ochratoxin A (OTA) is one of the most prevalent mycotoxins that threatens food and feed safety. Biodegradation of OTA has gained much attention. In this study, an...
Ochratoxin A (OTA) is one of the most prevalent mycotoxins that threatens food and feed safety. Biodegradation of OTA has gained much attention. In this study, an strain named ANSA176, with a strong OTA-detoxifying ability, was isolated from donkey intestinal chyme and characterized. The strain ANSA176 could degrade 97.43% of 1 mg/mL OTA into OTα within 12 h, at 37 °C. The optimal levels for bacterial growth were 22-37 °C and pH 6.0-9.0. The effects of ANSA176 on laying hens with an OTA-contaminated diet were further investigated. A total of 36 laying hens were assigned to three dietary treatments: control group, OTA (250 µg/kg) group, and OTA + ANSA176 (6.2 × 10 CFU/kg diet) group. The results showed that OTA decreased the average daily feed intake (ADFI) and egg weight (EW); meanwhile, it increased serum alanine aminopeptidase (AAP), leucine aminopeptidase (LAP), β2-microglobulin (β2-MG), immunoglobulin G (IgG), tumor necrosis factor-α (TNF-α), and glutathione reductase (GR). However, the ANSA176 supplementation inhibited or attenuated the OTA-induced damages. Taken together, OTA-degrading strain ANSA176 was able to alleviate the immune injury and inflammation induced by OTA.
Topics: Alcaligenes faecalis; Animal Feed; Animals; Chickens; Female; Inflammation; Ochratoxins
PubMed: 36006231
DOI: 10.3390/toxins14080569 -
Journal of Environmental Management Mar 2021Alcaligenes faecalis strain WT14 is heterotrophic nitrification and aerobic denitrification bacterium, newly isolated from a constructed wetland, and its feasibility in...
Alcaligenes faecalis strain WT14 is heterotrophic nitrification and aerobic denitrification bacterium, newly isolated from a constructed wetland, and its feasibility in nitrogen removal was investigated. The result showed sodium citrate was more readily utilized by WT14 as a carbon source. The response surface methodology model revealed the highest total nitrogen removal by WT14 occurred at 20.3 °C, 113.5 r·min, C/N 10.8, and pH 8.4. Under adapted environmental conditions, up to 55.9 mg·L·h of ammonium nitrogen (NH-N) was removed by WT14, and its NH-N tolerance ability reached 2000 mg·L. In addition to the reported high NH-resistance of Alcaligenes faecalis, WT14 multiplied fast and had strong nitrate or nitrite removal capacity when high strength nitrate or nitrite was provided as the single nitrogen source; which differed from other Alcaligenes faecalis species. These results show WT14 is a novel strain of Alcaligenes faecalis and its nitrogen removal pathway will be carried out in the further study.
Topics: Aerobiosis; Alcaligenes faecalis; Ammonium Compounds; Bacteria; Denitrification; Heterotrophic Processes; Nitrification; Nitrites; Nitrogen
PubMed: 33465711
DOI: 10.1016/j.jenvman.2021.111961 -
Microbiology Resource Announcements Apr 2022Alcaligenes faecalis is an opportunistic pathogen exhibiting drug resistance. Here, the 35,451-bp genome of phage Piluca is described. Piluca is not closely related to...
Alcaligenes faecalis is an opportunistic pathogen exhibiting drug resistance. Here, the 35,451-bp genome of phage Piluca is described. Piluca is not closely related to any isolated phages in the NCBI database. Piluca possesses genes encoding CI-like and Cro-like repressors and a tyrosine integrase, suggesting its temperate lifestyle.
PubMed: 35289650
DOI: 10.1128/mra.00124-22 -
Applied and Environmental Microbiology Mar 2022Ammonia oxidation is an important process in both the natural nitrogen cycle and nitrogen removal from engineered ecosystems. Recently, a new ammonia oxidation pathway...
Ammonia oxidation is an important process in both the natural nitrogen cycle and nitrogen removal from engineered ecosystems. Recently, a new ammonia oxidation pathway termed Dirammox (ect onia idation, NH→NHOH→N) has been identified in . However, whether Dirammox is present in other microbes, as well as its genetic regulation, remains unknown. In this study, it was found that the metabolically versatile bacterium Alcaligenes faecalis strain JQ135 could efficiently convert ammonia into N via NHOH under aerobic conditions. Genetic deletion and complementation results suggest that is responsible for the ammonia oxidation to N in this strain. Strain JQ135 also employs aerobic denitrification, mainly producing NO and trace amounts of N, with nitrite as the sole nitrogen source. Deletion of the and genes, which are essential for denitrification, did not impair the capability of JQ135 to oxidize ammonia to N (i.e., Dirammox is independent of denitrification). Furthermore, it was also demonstrated that (which encodes pyruvic oxime dioxygenase) was not involved in Dirammox and that (which was previously annotated as ammonia monooxygenase and is widespread in heterotrophic bacteria) was not an ammonia monooxygenase. The MocR-family transcriptional regulator DnfR was characterized as an activator of the operon with the binding motif 5'-TGGTCTGT-3' in the promoter region. A bioinformatic survey showed that homologs of genes are widely distributed in heterotrophic bacteria. In conclusion, this work demonstrates that, besides A. ammonioxydans, Dirammox occurs in other bacteria and is regulated by the MocR-family transcriptional regulator DnfR. Microbial ammonia oxidation is a key and rate-limiting step of the nitrogen cycle. Three previously known ammonia oxidation pathways (i.e., nitrification, anaerobic ammonia oxidation [Anammox], and complete ammonia oxidation [Comammox]) are mediated by autotrophic microbes. However, the genetic foundations of ammonia oxidation by heterotrophic microorganisms have not been investigated in depth. Recently, a previously unknown pathway, termed direct ammonia oxidation to N (Dirammox), has been identified in the heterotrophic bacterium HO-1. This paper shows that, in the metabolically versatile bacterium Alcaligenes faecalis JQ135, the Dirammox pathway is mediated by genes, which are independent of the denitrification pathway. A bioinformatic survey suggests that homologs of genes are widely distributed in bacteria. These findings enhance the understanding of the molecular mechanisms of heterotrophic ammonia oxidation to N.
Topics: Aerobiosis; Alcaligenes faecalis; Ammonia; Denitrification; Ecosystem; Nitrification; Nitrites; Nitrogen
PubMed: 35108103
DOI: 10.1128/aem.02261-21 -
Scientific Reports Sep 2022Pectin is one of the main structural components in fruits and an indigestible fiber made of D-galacturonic acid units with α (1-4) linkage. This study investigates the...
Pectin is one of the main structural components in fruits and an indigestible fiber made of D-galacturonic acid units with α (1-4) linkage. This study investigates the microbial degradation of pectin in apple waste and the production of bioactive compounds. Firstly, pectin-degrading bacteria were isolated and identified, then pectinolytic activity was assessed by DNS. The products were evaluated by TLC and LC-MS-ESI. The antioxidative effects were investigated using DPPH and anti-cancer effects and cytotoxicity were analyzed by MTT and flow cytometry. In this study two new bacterial isolates, Alcaligenes faecalis AGS3 and Paenibacillus polymyxa S4 with the pectinolytic enzyme were introduced. Structure analysis showed that the products of enzymatic degradation include unsaturated mono, di, tri, and penta galacturonic acids with 74% and 69% RSA at 40 mg/mL for A. faecalis and P. polymyxa S4, respectively. The results of anti-tumor properties on MCF-7 cells by MTT assay, for products of AGS3 and S4 at 40 mg/mL after 48 h, showed 7% and 9% survival, respectively. In the flow cytometric assessment, the compounds of AGS3 at 40 mg/mL were 100% lethal in 48 h and regarding S4 isolate caused 98% death. Cytotoxicity evaluation on L-929 cells showed no significant toxicity on living cells.
Topics: Alcaligenes faecalis; Hexuronic Acids; Malus; Paenibacillus; Paenibacillus polymyxa; Pectins; Polygalacturonase
PubMed: 36138114
DOI: 10.1038/s41598-022-20011-2