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Frontiers in Microbiology 2022The development of biofilm on the biotic and abiotic surfaces is the greatest challenge for health care sectors. At present times, oral infection is a common concern...
The development of biofilm on the biotic and abiotic surfaces is the greatest challenge for health care sectors. At present times, oral infection is a common concern among people with an unhealthy lifestyle and most of these biofilms-associated infections are resistant to antibiotics. This has increased a search for the development of alternate therapeutics for eradicating biofilm-associated infection. Nanobiotechnology being an effective way to combat such oral infections may encourage the use of herbal compounds, such as bio-reducing and capping agents. Green-synthesis of ZnO nanoparticles (ZnO NP) by the use of the floral extract of , a traditionally used medicinal plant, showed stability for a longer period of time. The NPs as depicted by the TEM image with a size of 10 nm showed excitation spectra at 360 nm and were found to remain stable for a considerable period of time. It was observed that the NPs were effective in the eradication of the oral biofilm formed by the major tooth attacking bacterial strains namely and , by bringing a considerable reduction in the extracellular polymeric substances (EPS). It was observed that the viability of the and was reduced by NP treatment to 87.89 ± 0.25% in comparison to that of amoxicillin. The results went in agreement with the findings of modeling performed by the use of response surface methodology (RSM) and artificial neural network (ANN). The microscopic studies and FT-IR analysis revealed that there was a considerable reduction in the biofilm after NP treatment. The studies further confirmed that the ZnO NPs showed considerable interactions with the biofilm-forming proteins. Hence, this study showed that ZnO NPs derived from can be used as an effective alternative therapeutic for the treatment of biofilm associated oral infection.
PubMed: 36262331
DOI: 10.3389/fmicb.2022.939390 -
Research in Microbiology 2023Alcaligenes faecalis D334 was determined in this study as a salt-tolerant bacterium isolated from mangrove sediment. In response to 6% (w/v) NaCl, strain D334 produced...
Phenotypic and genomic characterization provide new insights into adaptation to environmental stressors and biotechnological relevance of mangrove Alcaligenes faecalis D334.
Alcaligenes faecalis D334 was determined in this study as a salt-tolerant bacterium isolated from mangrove sediment. In response to 6% (w/v) NaCl, strain D334 produced the highest ectoines of 14.14 wt%. To understand adaptive features to mangrove environment, strain D334 was sequenced using Pacific BioScience platform, resulting in a circular chromosome of 4.23 Mb. Of note, D334 genome harbored 81 salt-responsive genes, among which two membrane-associated genes ompc and eric were absent in 3 selected A. faecalis genomes. Apart from that, a complete pathway for ectoine and 5-hydroxyectoine synthesis was predicted. To resist 40 mM HO, 46 genetic determinants contributing to oxidative stress response were employed. Moreover, two operons involved in polyhydroxyalkanoate (PHA) production were identified in the D334 genome, resulting in maximum PHA content of 5.03 ± 0.04 wt% and PHA concentration of 0.13 ± 0.001 g/L. A large flagellar biosynthesis operon contributing to swimming motility was found to be conserved in D334 and 8 other A. faecalis genomes. These findings shed light for the first time on the high versatility of A. faecalis D334 genome to adapt to mangrove lifestyle and the possibility to develop D334 as an industrial platform for PHA and 5-hydroxyectoine production.
Topics: Alcaligenes faecalis; Hydrogen Peroxide; Base Sequence; Adaptation, Physiological; Genomics
PubMed: 36240959
DOI: 10.1016/j.resmic.2022.103994 -
Biology Sep 2022Toxic shock caused by the discharge of biocide-contaminated fecal sludge (FS) from chemical toilets to conventional wastewater treatment plants (WWTP) can be a major...
Didecyldimethylammonium Chloride- and Polyhexamethylene Guanidine-Resistant Bacteria Isolated from Fecal Sludge and Their Potential Use in Biological Products for the Detoxification of Biocide-Contaminated Wastewater Prior to Conventional Biological Treatment.
Toxic shock caused by the discharge of biocide-contaminated fecal sludge (FS) from chemical toilets to conventional wastewater treatment plants (WWTP) can be a major problem in activated sludge operation. It is necessary to develop new environmental approaches to mitigate the toxicity of biocides in order to avoid degrading the performance of WWTP. "Latrina", a chemical toilet additive containing didecyldimethylammonium chloride and polyhexamethylene guanidine, is widely used in environmentally safe toilet complexes (ESTC) on Russian railway trains to deodorize FS and control microbial activity. In this work, seven biocide-resistant bacterial strains were isolated and identified from the FS of ESTC. The values of the minimum inhibitory and bactericidal concentrations of biocides for the isolated strains were 4.5-10 times higher than for the collection microorganisms. The bacterium DOS7 was found to be particularly resistant to "Latrina", the minimum inhibitory concentration of which was almost 30 times higher than recommended for ESTC. Biological products based on isolated bacterial strains proved to be effective for FS biodegradation under both aerobic and anaerobic conditions. The results of the biochemical oxygen demand test and the newly developed disk-diffusion bioassay confirmed that isolated strains contribute to reducing toxicity of biocidal agents in FS. Hyper-resistance, non-pathogenicity, and potential plant growth-promoting ability make DOS7 promising for use in various biological products for wastewater treatment and bioremediation of soils contaminated with biocides, as well as in agriculture to increase plant productivity.
PubMed: 36138811
DOI: 10.3390/biology11091332 -
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 -
Biology Jun 2022Brain natriuretic peptide (BNP) is secreted by the ventricles of the heart during overload to signal heart failure. Slight bilateral skin itching induced by BNP has been...
Brain natriuretic peptide (BNP) is secreted by the ventricles of the heart during overload to signal heart failure. Slight bilateral skin itching induced by BNP has been associated with response activity of the skin microbiota. In this work, we studied the effect of 25-250,000 pg BNP/mL on the growth, long-term survival, and stress (HO, antibiotics, salinity, heat and pH shock) resistance of human symbiont bacteria: Gram-positive C01 and Gram-negative DOS7. The effect of BNP turned out to be dose-dependent. Up to 250 pg BNP/mL made bacteria more stress resistant. At 2500 pg BNP/mL (heart failure) the thermosensitivity of the bacteria increased. Almost all considered BNP concentrations increased the resistance of bacteria to the action of tetracycline and ciprofloxacin. Both bacteria survived 1.3-1.7 times better during long-term (up to 4 months) storage. Our findings are important both for clinical medical practice and for practical application in other areas. For example, BNP can be used to obtain stress-resistant bacteria, which is important in the collection of microorganisms, as well as for the production of bacterial preparations and probiotics for cosmetology, agriculture, and waste management.
PubMed: 36101364
DOI: 10.3390/biology11070984 -
Case Reports in Medicine 2022() is a Gram-negative rod rarely isolated as an infective bacterium worldwide. The first cases of infections caused by this microorganism, such as pneumonia, soft...
() is a Gram-negative rod rarely isolated as an infective bacterium worldwide. The first cases of infections caused by this microorganism, such as pneumonia, soft tissue infections, urinary tract infections, bacteremia, and meningitis, date back more than 40 years and are almost entirely in newborns and immunosuppressed hosts. Optimal antibiotic therapy for has not been well established in the literature. We report a case of an immunocompetent patient in Colombia who had meningitis due to after a dental procedure. It is important to know about this microorganism that nowadays could be considered a potentially emerging pathogen in immunocompetent adults.
PubMed: 36092309
DOI: 10.1155/2022/1559360 -
Microorganisms Aug 2022Several diseases affect the productivity of olive trees, including root rot disease caused by genera. Chemical fungicides, which are often used to manage this disease,...
Several diseases affect the productivity of olive trees, including root rot disease caused by genera. Chemical fungicides, which are often used to manage this disease, have harmful side effects on humans as well as environmental components. Biological management is a promising control approach that has shown its great potential as an efficient eco-friendly alternative to treating root rot diseases. In the present study, the antagonistic activity of ten bacterial isolates was tested both in vitro and in planta against , the causal agent of olive root rot disease. These bacterial isolates belonging to the genera , , , , and were chosen for their potential antimicrobial effects against many pathogens. Results of the in vitro confrontation bioassay revealed a high reduction of mycelial growth exceeding 80%. The antifungal effect of the volatile organic compounds (VOCs) was observed for all the isolates, with mycelial inhibition rates ranging from 28.37 to 70.32%. Likewise, the bacterial cell-free filtrates showed important inhibition of the mycelial growth of the pathogen. Overall, their efficacy was substantially affected by the nature of the bacterial strains and their modes of action. A greenhouse test was then carried out to validate the in vitro results. Interestingly, two bacterial isolates, ACBC1 and SF14, were the most successful in managing the disease. Our findings suggested that these two antagonistic bacterial isolates have promising potential as biocontrol agents of olive root rot disease.
PubMed: 36014053
DOI: 10.3390/microorganisms10081635 -
Microorganisms Aug 2022Releasing multi-walled carbon nanotubes (MWCNTs) into ecosystems affects the biofilm formation and metabolic activity of bacteria in aquatic and soil environments....
Releasing multi-walled carbon nanotubes (MWCNTs) into ecosystems affects the biofilm formation and metabolic activity of bacteria in aquatic and soil environments. Pristine (pMWCNTs), oleophilic (oMWCNTs), hydrophilic (hMWCNTs), and carboxylated (cMWCNTs) carbon nanotubes were used to investigate their effects on bacterial biofilm. A pronounced probiofilm effect of modified MWCNTs was observed on the Gram-negative bacteria of C2, 11 h, and 2. None of the studied nanomaterials resulted in the complete inhibition of biofilm formation. The complete eradication of biofilms exposed to MWCNTs was not observed. The functionalization of carbon nanotubes was shown to change their probiofilm and antibiofilm effects. Gram-negative bacteria were the most susceptible to destruction, and among the modified MWCNTs, oMWCNTs had the greatest effect on biofilm destruction. The number of living cells in the biofilms was assessed by the reduction of XTT, and metabolic activity was assessed by the reduction of resazurin to fluorescent resorufin. The biofilms formed in the presence of MWCNTs reduced tetrozolium to formazan more actively than the control biofilms. When mature biofilms were exposed to MWCNTs, dehydrogenase activity decreased in 4-1, 11 h, and 2 in the presence of pMWCNTs and hMWCNTs, as well as in 11 h exposed to cMWCNTs. When mature biofilms were exposed to pMWCNTs, hMWCNTs, and cMWCNTs, the metabolism of cells decreased in most strains, and oMWCNTs did not have a pronounced inhibitory effect. The antibiofilm and probiofilm effects of MWCNTs were strain-dependent.
PubMed: 36014045
DOI: 10.3390/microorganisms10081627 -
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 -
Microbiology Spectrum Oct 2022Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is a pathogen of global concern due to the fact that therapeutic drugs are limited. Metallo-β-lactamase...
Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is a pathogen of global concern due to the fact that therapeutic drugs are limited. Metallo-β-lactamase (MBL)-producing P. aeruginosa has become a critical part of CRPA. Alcaligenes faecalis metallo-β-lactamase (AFM) is a newly identified subclass B1b MBL. In this study, 487 P. aeruginosa strains isolated from patients and the environment in an intensive care unit were screened for AFM alleles. Five AFM-producing strains were identified, including four AFM-2-producing strains (ST262) and one AFM-4-producing strain (ST671). AFM-2-producing strains were isolated from rectal and throat swabs, and AFM-4-producing strains were isolated from the water sink. The carrying plasmids belonged to the IncP-2 type, while the carrying plasmid pAR19438 was a pSTY-like megaplasmid. Plasmid pAR19438 was acquired by the integration of the Tn-like transposon. All genes were embedded in an IS- unit core module flanked by class 1 integrons. The core module of was IS-Δ---Δ-ΔIS, while the core module of was IS-Δ---Δ-IS-----ΔIS. The flanking sequences of IS- units also differed. The expression of AFM-2 and AFM-4 in DH5α and PAO1 illustrated the same effect for the evaluation of the MICs of β-lactams, except for aztreonam. Identification of AFM-4 underscores that the quick spread and emerging development of mutants of MBLs require continuous surveillance in P. aeruginosa. Acquiring metallo-β-lactamase genes is one of the important carbapenem resistance mechanisms of P. aeruginosa. Alcaligenes faecalis metallo-β-lactamase is a newly identified metallo-β-lactamase, the prevalence and genetic context of which need to be explored. In this study, we identified AFM-producing P. aeruginosa strains among clinical isolates and found a new mutant of AFM, AFM-4. The carrying plasmid pAR19438 was a pSTY-like megaplasmid, unlike the plasmids encoding other alleles. The genetic context of was also different. However, AFM-2 and AFM-4 had the same impacts on antibiotic susceptibility. The presence and transmission of AFM alleles in P. aeruginosa pose a challenge to clinical practice.
Topics: Humans; Alleles; Anti-Bacterial Agents; Aztreonam; beta-Lactam Resistance; beta-Lactamases; Carbapenems; Microbial Sensitivity Tests; Plasmids; Pseudomonas aeruginosa; Pseudomonas Infections
PubMed: 36000902
DOI: 10.1128/spectrum.02035-22