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Journal of Food Protection Jul 2023The purpose of the study was to investigate the mechanism of inactivation of Serratia liquefaciens by different treatments, namely corona discharge plasma (CDP),...
The purpose of the study was to investigate the mechanism of inactivation of Serratia liquefaciens by different treatments, namely corona discharge plasma (CDP), ε-polylysine (ε-PL), and corona discharge plasma combined with ε-polylysine (CDP plus ε-PL). The results showed that the combined treatment of CDP and ε-PL exhibited significant antibacterial effects. The total number of colonies of S. liquefaciens dropped by 0.49 log CFU/mL following 4 min of CDP treatment, 4MIC ε-PL treatment for 6 h alone decreased the amounts of colonies by 2.11 log CFU/mL, and 6 h of treatment with 4MIC ε-PL after the bacterium was treated with CDP could decrease the number of colonies by 6.77 log CFU/mL. Scanning electron microscopy images showed that the combined treatment of CDP and ε-PL caused the most serious damage to the cell morphology. Electrical conductivity, nucleic acid, and PI staining indicated that the combined treatment dramatically enhanced the permeability of the cell membrane. In addition, the combined treatment led to a significant decrease in SOD and POD enzyme activities in S. liquefaciens, which prevented energy metabolism. Finally, the determination of free and intracellular ε-PL concentrations confirmed that the treatment of CDP could cause the bacteria to bind more ε-PL and exert more significant bacterial inhibition. Therefore, CDP and ε-PL had a synergistic effect in the inhibition of S. liquefaciens.
Topics: Polylysine; Serratia liquefaciens; Anti-Bacterial Agents; Cell Membrane; Microscopy, Electron, Scanning
PubMed: 37295216
DOI: 10.1016/j.jfp.2023.100078 -
Frontiers in Microbiology 2019Various chemical compounds emerged including kraft lignin (KL) during the processes of papermaking. These chemical compounds in effluent of the paper industry have...
Various chemical compounds emerged including kraft lignin (KL) during the processes of papermaking. These chemical compounds in effluent of the paper industry have hazardous environmental impacts. KL is liable for causing pollution of aquatic and water bodies; hence, it must be minimized in order to maintain a healthy and sustainable environment. In the present study, KL degradation was performed with ligninolytic bacterium and we confirmed biotransformation of KL to various less polluted or harmless compounds. KL being degraded as 1000 mg/L concentration with incubating 30°C for 72, 168, and 240 h, shaking at 120 rpm under laboratory conditions. We found 65% maximum degradation of KL and 62% decolorization by the treatment with for 240 h (10 days). After being the treatment of KL, clear changes were observed in its morphology (using scanning electron microscopy and stereo microscopy), hydrodynamic size (using dynamic light scattering), and the functional groups [using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR)]. Biotransformation of KL monitored by Gas Chromatography-Mass Spectrometry (GC-MS) revealed formation of various metabolites. In addition to degradation of KL, detoxification (involving biotransformation into various metabolites) was assessed using cytotoxicity assays 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide [MTT and calcein-acetoxymethyl (AM) assays] using a human kidney cell line (NRK-52E), which indicated improved cell survival rates (74% for the bacteria-treated KL solution treated for 240 h) compared to the control (27%). Thus, the present study suggests that bacteria ciens might be useful in reducing the pollution of KL by transforming it into various metabolites along with cytotoxicity reduction for environmental protection.
PubMed: 31824434
DOI: 10.3389/fmicb.2019.02364 -
The New England Journal of Medicine Jan 2017
Topics: Adult; Female; Humans; Mycobacterium Infections, Nontuberculous; Mycobacterium marinum; Nose; Nose Diseases; Serratia Infections; Serratia liquefaciens
PubMed: 28099826
DOI: 10.1056/NEJMicm1604459 -
Transactions of the Royal Society of... Oct 2018Human infections with Serratia spp. are generally limited to Serratia marcescens and the Serratia liquefaciens complex. There is little data regarding the infections...
BACKGROUND
Human infections with Serratia spp. are generally limited to Serratia marcescens and the Serratia liquefaciens complex. There is little data regarding the infections caused by the remaining Serratia spp., as they are seldom isolated from clinical specimens.
METHODS
In this health care setting in Kathmandu, Nepal routine blood culture is performed on all febrile patients with a temperature >38°C or when there is clinical suspicion of bacteremia. During 2015 we atypically isolated and identified several Serratia spp. We extracted clinical data from these cases and performed whole genome sequencing on all isolates using a MiSeq system (Ilumina, San Diego, CA, USA).
RESULTS
Between June and November 2015, we identified eight patients with suspected bacteremia that produced a positive blood culture for Serratia spp., six Serratia rubidaea and five Serratia marcescens. The S. rubidaea were isolated from three neonates and were concentrated in the neonatal intensive care unit between June and July 2015. All patients were severely ill and one patient died. Whole genome sequencing confirmed that six Nepalese S. rubidaea sequences were identical and indicative of a single-source outbreak.
CONCLUSIONS
Despite extensive screening we were unable to identify the source of the outbreak, but the inferred timeline suggested that these atypical infections were associated with the aftermath of two massive earthquakes. We speculate that deficits in hygienic behavior, combined with a lack of standard infection control, in the post-earthquake emergency situation contributed to these unusual Serratia spp. outbreaks.
Topics: Cross Infection; Earthquakes; Humans; Infant, Newborn; Infant, Premature; Infection Control; Intensive Care Units, Neonatal; Microbial Sensitivity Tests; Nepal; Serratia; Serratia Infections; Serratia marcescens
PubMed: 30107587
DOI: 10.1093/trstmh/try077 -
Scientific Reports Nov 2019Serratia liquefaciens strain FG3 (SlFG3), isolated from the flower of Stachytarpheta glabra in the Brazilian ferruginous fields, has distinctive genomic, adaptive, and...
Serratia liquefaciens strain FG3 (SlFG3), isolated from the flower of Stachytarpheta glabra in the Brazilian ferruginous fields, has distinctive genomic, adaptive, and biotechnological potential. Herein, using a combination of genomics and molecular approaches, we unlocked the evolution of the adaptive traits acquired by S1FG3, which exhibits the second largest chromosome containing the largest conjugative plasmids described for Serratia. Comparative analysis revealed the presence of 18 genomic islands and 311 unique protein families involved in distinct adaptive features. S1FG3 has a diversified repertoire of genes associated with Nonribosomal peptides (NRPs/PKS), a complete and functional cluster related to cellulose synthesis, and an extensive and functional repertoire of oxidative metabolism genes. In addition, S1FG3 possesses a complete pathway related to protocatecuate and chloroaromatic degradation, and a complete repertoire of genes related to DNA repair and protection that includes mechanisms related to UV light tolerance, redox process resistance, and a laterally acquired capacity to protect DNA using phosphorothioation. These findings summarize that SlFG3 is well-adapted to different biotic and abiotic stress situations imposed by extreme conditions associated with ferruginous fields, unlocking the impact of the lateral gene transfer to adjust the genome for extreme environments, and providing insight into the evolution of prokaryotes.
Topics: Acclimatization; Biological Evolution; Brazil; Extreme Environments; Extremophiles; Flowers; Genes, Bacterial; Genomic Islands; Genomics; Lamiales; Phylogeny; Plasmids; Serratia liquefaciens
PubMed: 31784663
DOI: 10.1038/s41598-019-54601-4 -
Microorganisms Jun 2022Histamine is a toxic biogenic amine commonly found in seafood products or their derivatives. This metabolite is produced by histamine-producing bacteria (HPB) such as ,... (Review)
Review
Histamine is a toxic biogenic amine commonly found in seafood products or their derivatives. This metabolite is produced by histamine-producing bacteria (HPB) such as , , , , , , , , spp., , , , , , , , , , spp., , , , , , and In this review, the role of these bacteria in histamine production in fish and seafood products with consequences for human food poisoning following consumption are discussed. In addition, methods to control their activity in countering histamine production are proposed.
PubMed: 35744715
DOI: 10.3390/microorganisms10061197 -
Frontiers in Microbiology 2022Fish disease surveillance methods can be complicated and time consuming, which limits their value for timely intervention strategies on aquaculture farms. Novel...
Fish disease surveillance methods can be complicated and time consuming, which limits their value for timely intervention strategies on aquaculture farms. Novel molecular-based assays using droplet digital Polymerase Chain Reaction (ddPCR) can produce immediate results and enable high sample throughput with the ability to multiplex several targets using different fluorescent dyes. A ddPCR tetraplex assay was developed for priority salmon diseases for farmers in New Zealand including New Zealand -like organism 1 (NZ-RLO1), NZ-RLO2, , and . The limit of detection in singleplex and tetraplex assays was reached for most targets at 10 ng/μl with, respectively, NZ-RLO1 = 0.931 and 0.14 copies/μl, NZ-RLO2 = 0.162 and 0.21 copies/μl, 0.345 and 0.93 copies/μl, while the limit of detection for was 10 with 1.0 copies/μl and 0.7 copies/μl. While specificity of primers was demonstrated in previous studies, we detected cross-reactivity of with some strains of and with , respectively. The tetraplex assay was applied as part of a commercial fish disease surveillance program in New Zealand for 1 year to demonstrate the applicability of tetraplex tools for the salmonid aquaculture industry.
PubMed: 35531301
DOI: 10.3389/fmicb.2022.885585 -
Life (Basel, Switzerland) May 2021is a cold-adapted facultative anaerobic astrobiology model organism with the ability to grow at a Martian atmospheric pressure of 7 hPa. Currently there is a lack of...
is a cold-adapted facultative anaerobic astrobiology model organism with the ability to grow at a Martian atmospheric pressure of 7 hPa. Currently there is a lack of data on its limits of growth and metabolic activity at sub-zero temperatures found in potential habitable regions on Mars. Growth curves and nano-scale secondary ion mass spectrometry (NanoSIMS) were used to characterize the growth and metabolic threshold for ATCC 27,592 grown at and below 0 °C. Cells were incubated in Spizizen medium containing three stable isotopes substituting their unlabeled counterparts; i.e., C-glucose, (NH)SO, and HO; at 0, -1.5, -3, -5, -10, or -15 °C. The isotopic ratios of C/C, N/N, and O/O and their corresponding fractions were determined for 240 cells. NanoSIMS results revealed that with decreasing temperature the cellular amounts of labeled ions decreased indicating slower metabolic rates for isotope uptake and incorporation. Metabolism was significantly reduced at -1.5 and -3 °C, almost halted at -5 °C, and shut-down completely at or below -10 °C. While growth was observed at 0 °C after 5 days, samples incubated at -1.5 and -3 °C exhibited significantly slower growth rates until growth was detected at 70 days. In contrast, cell densities decreased by at least half an order of magnitude over 70 days in cultures incubated at ≤ -5 °C. Results suggest that , if transported to Mars, might be able to metabolize and grow in shallow sub-surface niches at temperatures above -5 °C and might survive-but not grow-at temperatures below -5 °C.
PubMed: 34065549
DOI: 10.3390/life11050459 -
Antibiotics (Basel, Switzerland) Mar 2022The periodontal microbiota is ecologically diverse and may facilitate colonization by bacteria of enteric origin (, ) and co-infections with , possibly producing...
The periodontal microbiota is ecologically diverse and may facilitate colonization by bacteria of enteric origin (, ) and co-infections with , possibly producing subgingival biofilms with high antimicrobial tolerance. This retrospective surveillance study followed periodontitis-associated superinfection profiles in a large patient sample. From 2008 to 2015, biofilm samples from deep periodontal pockets were collected from a total of 16,612 German adults diagnosed with periodontitis. The presence of selected , , and was confirmed in overnight cultures. Antimicrobial susceptibility of these clinical isolates was tested by disk diffusion with antibiotics routinely used for treatment of oral infections, e.g., amoxicillin (AML), amoxicillin/clavulanic acid (AMC), doxycycline (DO), and ciprofloxacin (CIP). The mean annual prevalence of patients harboring in periodontal plaques was 11.5% in total and ranged from 2.5% for to 3.6% for , 1.1% for , 2.8% for , and 1.5% for . In comparison, the mean detection rates for microbiota typically found in the oral cavity were higher, e.g., 5.6% for spp. and 21.8% for . Among the , species harboring intrinsic resistance to AML ( spp., spp., spp.) were predominant. Non-susceptibility to AMC was observed for spp. and . By contrast, spp. only showed non-susceptibility to DO and CIP. Trends for increasing resistance were found to AML in and to DO in spp. Trend analysis showed decreasing resistance to AMC in and ; and to DO in , and . This study confirms the low but consistent presence of and among the subgingival microbiota recovered from periodontitis specimen. Although their pathogenetic role in periodontal lesions remains unclear, their presence in the oral cavity should be recognized as a potential reservoir for development and spread of antibiotic resistance in light of antibiotic usage in oral infections.
PubMed: 35326848
DOI: 10.3390/antibiotics11030385 -
International Journal of Molecular... Oct 2018High salinity mitigates crop productivity and quality. Plant growth-promoting soil rhizobacteria (PGPR) improve plant growth and abiotic stress tolerance via mediating...
High salinity mitigates crop productivity and quality. Plant growth-promoting soil rhizobacteria (PGPR) improve plant growth and abiotic stress tolerance via mediating various physiological and molecular mechanisms. This study investigated the effects of the PGPR strain KM4 on the growth and physiological and molecular responsiveness of maize ( L.) plants under salinity stress (0, 80, and 160 mM NaCl). High salinity significantly reduced plant growth and biomass production, nutrient uptake, leaf relative water content, pigment content, leaf gas exchange attributes, and total flavonoid and phenolic contents in maize. However, osmolyte content (e.g., soluble proteins, proline, and free amino acids), oxidative stress markers, and enzymatic and non-enzymatic antioxidants levels were increased in maize under high salinity. On the other hand, KM4 inoculation significantly reduced oxidative stress markers, but increased the maize growth and biomass production along with better leaf gas exchange, osmoregulation, antioxidant defense systems, and nutrient uptake under salt stress. Moreover, it was found that all these improvements were accompanied with the upregulation of stress-related genes (, , , , , , , and ), and downregulation of the key gene in ABA biosynthesis (). Taken together, the results demonstrate the beneficial role of KM4 in improving plant growth and salt stress tolerance in maize by regulating ion homeostasis, redox potential, leaf gas exchange, and stress-related genes expression.
Topics: Gene Expression Regulation, Plant; Homeostasis; Oxidation-Reduction; Plant Leaves; Plant Transpiration; Rhizosphere; Salt Tolerance; Serratia liquefaciens; Zea mays
PubMed: 30355997
DOI: 10.3390/ijms19113310