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Access Microbiology 2023This study aimed to characterize the virulence factors and antimicrobial resistance of , an opportunistic pathogen that causes human infections. We examined 45 isolates...
This study aimed to characterize the virulence factors and antimicrobial resistance of , an opportunistic pathogen that causes human infections. We examined 45 isolates of both genotypically and phenotypically by studying their adherence to HeLa cells, biofilm formation, cytotoxicity and antimicrobial resistance, and analysed their genomes for putative virulence and resistance genes. This study found that most isolates possessed multiple virulence genes, including A, A, A, A, A and A, and were cytotoxic to Vero cells. All the isolates were resistant to amoxicillin plus clavulanic acid, levofloxacin and sulfamethoxazole plus trimethoprim, and most were resistant to ceftriaxone and cefepime. All isolates harboured extended-spectrum beta-lactamase coding genes such as and 23/45(51.11 %) of them also harboured . The gene KPC-2 (carbapenemase) was detected in 8/45(17.77 %) isolates. This study also found clonality among the isolates, indicating the possible spread of the pathogen among patients at the hospital. These results have significant clinical and epidemiological implications and emphasize the importance of a continued understanding of the virulence and antimicrobial resistance of this pathogen for the prevention and treatment of future infections.
PubMed: 37970084
DOI: 10.1099/acmi.0.000652.v4 -
Frontiers in Microbiology 2023Ticks and fleas, as blood-sucking arthropods, carry and transmit various zoonotic diseases. In the natural plague foci of China, monitoring of has been continuously...
INTRODUCTION
Ticks and fleas, as blood-sucking arthropods, carry and transmit various zoonotic diseases. In the natural plague foci of China, monitoring of has been continuously conducted in and other host animals, whereas other pathogens carried by vectors are rarely concerned in the Qinghai-Tibet Plateau.
METHODS
In this study, we investigated the microbiota of ticks and fleas sampling from in the Plateau, China by metataxonomics combined with metagenomic methods.
RESULTS
By metataxonomic approach based on full-length 16S rDNA amplicon sequencing and operational phylogenetic unit (OPU) analyses, we described the microbiota community of ticks and fleas at the species level, annotated 1,250 OPUs in ticks, including 556 known species and 492 potentially new species, accounting for 48.50% and 41.71% of the total reads in ticks, respectively. A total of 689 OPUs were detected in fleas, consisting of 277 known species (40.62% of the total reads in fleas) and 294 potentially new species (56.88%). At the dominant species categories, we detected the (OPU 421) and potentially pathogenic new species of , and . Using shotgun sequencing, we obtained 10 metagenomic assembled genomes (MAGs) from vector samples, including a known species ( DFT2), and six new species affliated to four known genera, i.e., , and . By the phylogenetic analyses based on full-length 16S rRNA genes and core genes, we identified that ticks harbored pathogenic . Moreover, these potentially pathogenic novel species were more closely related to subsp. , and , respectively. The OPU 422 Ehrlichia sp1 was most related to and . The OPU 230 sp1 and spp. (DTF8 and DTF9) was clustered with . The OPU 427 sp1 was clustered with .
DISCUSSION
The findings of the study have advanced our understanding of the potential pathogen groups of vectors in marmot () in the Qinghai-Tibet Plateau.
PubMed: 37415819
DOI: 10.3389/fmicb.2023.1188155 -
Scientific Reports Oct 2018In this study, a novel gene for Glutamine synthetase was cloned and characterized for its activities and stabilities from a marine bacterium Providencia vermicola...
In this study, a novel gene for Glutamine synthetase was cloned and characterized for its activities and stabilities from a marine bacterium Providencia vermicola (PveGS). A mutant S54A was generated by site directed mutagenesis, which showed significant increase in the activity and stabilities at a wide range of temperatures. The K values of PveGS against hydroxylamine, ADP-Na and L-Glutamine were 15.7 ± 1.1, (25.2 ± 1.5) × 10 and 32.6 ± 1.7 mM, and the k were 17.0 ± 0.6, 9.14 ± 0.12 and 30.5 ± 1.0 s respectively. In-silico-analysis revealed that the replacement of Ser at 54th position with Ala increased the catalytic activity of PveGS. Therefore, catalytic efficiency of mutant S54A had increased by 3.1, 0.89 and 2.9-folds towards hydroxylamine, ADP-Na and L-Glutamine respectively as compared to wild type. The structure prediction data indicated that the negatively charged pocket becomes enlarged and hydrogen bonding in Ser54 steadily promotes the product release. Interestingly, the residual activity of S54A mutant was increased by 10.7, 3.8 and 3.8 folds at 0, 10 and 50 °C as compared to WT. Structural analysis showed that S54A located on the loop near to the active site improved its flexibility due to the breaking of hydrogen bonds between product and enzyme. This also facilitated the enzyme to increase its cold adaptability as indicated by higher residual activity shown at 0 °C. Thus, replacement of Ala to Ser54 played a pivotal role to enhance the activities and stabilities at a wide range of temperatures.
Topics: Ammonium Compounds; Binding Sites; Cloning, Molecular; Detergents; Enzyme Stability; Glutamate-Ammonia Ligase; Hydrogen-Ion Concentration; Indicators and Reagents; Kinetics; Ligands; Metals; Molecular Docking Simulation; Mutagenesis, Site-Directed; Mutant Proteins; Providencia; Structural Homology, Protein; Temperature
PubMed: 30353099
DOI: 10.1038/s41598-018-34022-5 -
Microorganisms Apr 2022is a highly social pathogen responsible for nosocomial chronic urinary tract infections. The bacterium indeed forms floating communities of cells (FCC) besides and...
is a highly social pathogen responsible for nosocomial chronic urinary tract infections. The bacterium indeed forms floating communities of cells (FCC) besides and prior-to canonical surface-attached biofilms (SAB). Within FCC, cells are riveted one to another owing to by self-interactions between its porins, viz. Omp-Pst1 and Omp-Pst2. In pathophysiological conditions, is principally exposed to high concentrations of urea, ammonia, bicarbonate, creatinine and to large variations of pH, questioning how these environmental cues affect socialization, and whether formation of SAB and FCC protects cells against those. Results from our investigations indicate that FCC and SAB can both form in the urinary tract, endowing cells with increased resistance and fitness. They additionally show that while Omp-Pst1 is the main gateway allowing penetration of urea, bicarbonate and ammonia into the periplasm, expression of Omp-Pst2 enables resistance to them.
PubMed: 35630346
DOI: 10.3390/microorganisms10050901 -
Journal of Environmental Sciences... Oct 2024Tri (2-chloropropyl) phosphate (TCPP) was an emerging contaminant of global concern because of its frequent occurrence, potential toxic effects, and persistence in the...
Tri (2-chloropropyl) phosphate (TCPP) was an emerging contaminant of global concern because of its frequent occurrence, potential toxic effects, and persistence in the environment. Microbial degradation might be an efficient and safe removal method, but limited information was available. In this study, Providencia rettgeri was isolated from contaminated sediment and showed it could use TCPP as unique phosphorus source to promote growth, and decompose 34.7% of TCPP (1 mg/L) within 5 days. The microbial inoculation and the initial concentration of TCPP could affect the biodegradation efficient. Further study results indicated that TCPP decomposition by Providencia rettgeri was mainly via phosphoester bond hydrolysis, evidenced by the production of bis (2-chloropropyl) phosphate (CHClPO) and mono-chloropropyl phosphate (CHClPO). Both intracellular and extracellular enzymes could degrade TCPP, but intracellular degradation was dominant in the later reaction stage, and the presence of Cu ions had a promoting effect. These findings developed novel insights into the potential mechanism of TCPP microbial degradation.
Topics: Providencia; Biodegradation, Environmental; Phosphates; Water Pollutants, Chemical
PubMed: 38802235
DOI: 10.1016/j.jes.2023.07.023 -
International Journal of Molecular... Mar 2023The gut microbiota is increasingly considered to play a key role in human immunity and health. The aging process alters the microbiota composition, which is associated...
The gut microbiota is increasingly considered to play a key role in human immunity and health. The aging process alters the microbiota composition, which is associated with inflammation, reactive oxygen species (ROS), decreased tissue function, and increased susceptibility to age-related diseases. It has been demonstrated that plant polysaccharides have beneficial effects on the gut microbiota, particularly in reducing pathogenic bacteria abundance and increasing beneficial bacteria populations. However, there is limited evidence of the effect of plant polysaccharides on age-related gut microbiota dysbiosis and ROS accumulation during the aging process. To explore the effect of Eucommiae polysaccharides (EPs) on age-related gut microbiota dysbiosis and ROS accumulation during the aging process of Drosophila, a series of behavioral and life span assays of Drosophila with the same genetic background in standard medium and a medium supplemented with EPs were performed. Next, the gut microbiota composition and protein composition of Drosophila in standard medium and the medium supplemented with EPs were detected using 16S rRNA gene sequencing analysis and quantitative proteomic analysis. Here, we show that supplementation of Eucommiae polysaccharides (EPs) during development leads to the life span extension of Drosophila. Furthermore, EPs decreased age-related ROS accumulation and suppressed , , and in aged Drosophila. Increased , , and in the indigenous microbiota might induce age-related gut dysfunction in Drosophila and shortens their life span. Our study demonstrates that EPs can be used as prebiotic agents to prevent aging-associated gut dysbiosis and reactive oxidative stress.
Topics: Humans; Animals; Aged; Drosophila; Reactive Oxygen Species; Dysbiosis; RNA, Ribosomal, 16S; Proteomics; Polysaccharides; Aging; Enterobacteriaceae; Life Expectancy
PubMed: 36982954
DOI: 10.3390/ijms24065881 -
Cell Reports Mar 2022Diet is a key regulator of metabolism and interacts with the intestinal microbiome. Here, we study the role of the Drosophila intestinal stem cell (ISC)-specific biotin...
Diet is a key regulator of metabolism and interacts with the intestinal microbiome. Here, we study the role of the Drosophila intestinal stem cell (ISC)-specific biotin transporter Smvt in midgut homeostasis, infection-induced regeneration, and tumorigenesis. We show that Smvt-transported biotin in ISCs is necessary for ISC mitosis. Smvt deficiency impairs intestinal maintenance, which can be rescued by the human Smvt, encoded by SLC5A6. ISC-specific, Smvt-silenced flies exhibit microbial dysbiosis, whereby the growth of Providencia sneebia, an opportunistic pathogen, is favored. Dysbiosis correlates with increased Nox expression, reactive oxygen species (ROS), and enterocyte apoptosis. Flies acquire biotin from their diet and microbiota. We show that, when dietary biotin is scarce, biotin-producing commensals, e.g., E. coli, can rescue reduced ISC mitosis. Smvt and commensals also control intestinal tumor growth. Our findings suggest that direct modification of the gut microbiome by biotin can serve as an approach for the treatment of dysbiosis-promoted diseases and tumorigenesis control.
Topics: Biotin; Carcinogenesis; Dysbiosis; Escherichia coli; Gastrointestinal Microbiome; Humans; Mitosis; Stem Cells
PubMed: 35263602
DOI: 10.1016/j.celrep.2022.110505 -
International Journal of Antimicrobial... May 2024Providencia species are important opportunistic pathogens for humans and are associated with several infectious diseases. In this study, we found three clinical strains...
Providencia species are important opportunistic pathogens for humans and are associated with several infectious diseases. In this study, we found three clinical strains belonging to a novel Providencia species, namely Providencia huashanensis, including strains CRE-3FA-0001, CRE-138-0026, and CRE-138-0111. These strains were recovered from three patients, and all of them were associated with nosocomial infections, including incision infection, urinary tract infection, and intracranial infection. The three strains showed high-level resistance to many types of antimicrobials, including amikacin, aztreonam, ceftazidime, cefepime, ciprofloxacin, colistin, polymyxin B, imipenem, meropenem, ceftazidime-avibactam, imipenem-relebactam. Investigation of the resistance mechanism revealed that acquired resistance genes such as bla, bla, bla, bla, aac, ant, and qnrD, played an important role in the multidrug-resistant phenotype for the three strains. The phylogenetic trees were reconstructed based on the 16S rRNA gene sequences, multi-locus sequence analysis, and core single nucleotide polymorphisms. The genome sequence of the strains had a range of 83.5%-85.8% average nucleotide identity and 21%-25.5% in silico DNA-DNA hybridization scores with other Providencia type strains. The average nucleotide identity and in silico DNA-DNA hybridization values and the phylogenetic trees indicated that the strains CRE-3FA-0001, CRE-138-0026, and CRE-138-0111 strains should be considered as a novel species of the genus Providencia, for which the name P. huashanensis sp. nov. is proposed. The type strain is CRE-3FA-0001 = China Center for Type Culture Collection AB 2023186 = Korean Collection for Type Cultures 8373.
PubMed: 38795927
DOI: 10.1016/j.ijantimicag.2024.107211 -
BMC Microbiology Oct 2023This study aimed to investigate the clinical infection characteristics and analyze the resistance gene carrying status of carbapenem-resistant Providencia rettgeri via...
OBJECTIVE
This study aimed to investigate the clinical infection characteristics and analyze the resistance gene carrying status of carbapenem-resistant Providencia rettgeri via whole genome sequencing (WGS).
METHODS
Carbapenem-resistant P. rettgeri were collected from clinical patients between January 2020 and December 2021, and their susceptibility to 19 antimicrobial drugs was determined using the VITEK 2 Compact system and Kirby-Bauer (KB) disk diffusion method. The Illumina platform was used to perform WGS of the P. rettgeri isolates, and the resistance genes carried by the Carbapenem-resistant P. rettgeri strains were detected via ABRicate software. The phylogenetic tree was constructed by thirty-four strains including twenty-eight strains downloaded from NCBI database and the carbapenem-resistant six P. rettgeri strains in this study. Which based on genomic single nucleotide polymorphism (SNP) to understand the affinities of the carbapenem-resistant P. rettgeri strains.
RESULTS
Six carbapenem-resistant P. rettgeri strains were isolated from five different clinical departments using the blood, urine, sputum, and secretion specimens. These infected patients are middle-aged and elderly people with a history of severe trauma, tumors, hypertension, and various other underlying diseases, and invasive procedures. Antimicrobial sensitivity testing showed that all strains presented resistance to ampicillin-sulbactam, ceftazidime, ciprofloxacin, levofloxacin, and ertapenem, whereas they exhibited full susceptibility to cefepime and amikacin. Most strains demonstrated high resistance to β-lactams, aminoglycosides, and sulfonamides. Thirty-five resistance genes were identified by ABRicate. All carbapenem-resistant P. rettgeri strains carried aminoglycoside, fluoroquinolone, chloramphenicol, rifampicin, sulfonamide, and β-lactam resistance genes, and most importantly, all strains possessed the carbapenem resistance gene bla. The six P. rettgeri strains in this study and the 28 carbapenem-resistant P. rettgeri strains from the NCBI database were divided into four evolutionary groups. The WF3643, WF3849, WF3822, and WF3821 strains in this study were in the same evolutionary group (clade A), while the closely related WF3099 and WF3279 strains were in different evolutionary groups (clade B and clade D), respectively. The WF3099 strain was distantly related to the other five strains.
CONCLUSION
Carbapenem-resistant P. rettgeri strains were mostly isolated from middle-aged and older patients with a history of surgery or serious underlying diseases, and they were found to cause multisystem infections. All Carbapenem-resistant P. rettgeri strains in this study carried bla and multiple antimicrobial drug resistance genes. Furthermore, the P. rettgeri strains in this study were closely related, suggesting the possibility of nosocomial infections. Therefore, our study highlights the need for research on P. rettgeri to control the spread of these nosocomial infections.
Topics: Middle Aged; Aged; Humans; beta-Lactamases; Phylogeny; Anti-Bacterial Agents; Carbapenems; Aminoglycosides; Whole Genome Sequencing; Cross Infection; Microbial Sensitivity Tests
PubMed: 37789331
DOI: 10.1186/s12866-023-03032-3 -
Animals : An Open Access Journal From... Nov 2023This work aimed to determine the presence of bacterial pathogens in fish with a clinical picture suggestive of infectious disease in Nile tilapia reared in Chiapas,...
This work aimed to determine the presence of bacterial pathogens in fish with a clinical picture suggestive of infectious disease in Nile tilapia reared in Chiapas, Mexico. Blood and viscera samples were taken from healthy and diseased animals from commercial farms. Clinical and pathological examinations of each individual were performed and samples were collected for bacteriological studies. The bacterial isolates were identified and characterized by culture, biochemical tests, antibiogram, challenge tests and 16S rRNA sequencing. and were isolated from various diseased organisms. The clinical picture caused by was characterized by appetite disorders, neurological signs, nodulation or ulceration in different areas and congestion or enlargement of internal organs. Providenciosis in juvenile specimens caused a characteristic picture of hemorrhagic septicemia. Challenge tests performed in healthy organisms revealed that both infections caused higher mortality rates in fish ( < 0.05) compared with non-infected specimens, with 100% survival. There was 100% mortality for animals infected with after three days post infection and 45% for those infected with . The isolation and identification of two pathogens involved in an infection process were achieved and cataloged as potential causal agents of disease outbreaks in tilapia farming in Mexico. This is the first report of possible bacterial infection caused by and in tilapia farms, which are two uncommon but potentially emerging pathogens for the species.
PubMed: 38067066
DOI: 10.3390/ani13233715