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Pharmaceutics Apr 2021Antimicrobial resistance (AMR), one of the greatest issues for humankind, draws special attention to the scientists formulating new drugs to prevent it. Great emphasis...
Antimicrobial resistance (AMR), one of the greatest issues for humankind, draws special attention to the scientists formulating new drugs to prevent it. Great emphasis on the biological synthesis of silver nanoparticles (AgNPs) for utilization in single or combinatorial therapy will open up new avenues to the discovery of new antimicrobial drugs. The purpose of this study was to synthesize AgNPs following a green approach by using an endophytic bacterial strain, , and to assess their antimicrobial potential against five pathogenic and four multidrug-resistant (MDR) microbes. UV-Vis spectroscopy, fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), and zeta potential (ζ) were used to characterize the synthesized AgNPs. Endophytic -mediated AgNPs (Eh-AgNPs) were represented by a strong UV-Vis absorbance peak at 418 nm within 5 min, forming spherical and polydispersed nanoparticles in the size range of 9.91 nm to 92.54 nm. The Eh-AgNPs were moderately stable with a mean ζ value of -19.73 ± 3.94 mV. The presence of amine, amide, and hydroxyl functional groups was observed from FTIR analysis. In comparison to conventional antibiotics, the Eh-AgNPs were more effective against (ATCC 10876) and (ATCC 10231), exhibiting 9.14 ± 0.05 mm and 8.24 ± 0.05 mm zones of inhibition (ZOIs), respectively, while displaying effective inhibitory activity with ZOIs ranging from 10.98 ± 0.08 to 13.20 ± 0.07 mm against the MDR bacteria. Eh-AgNP synthesis was rapid and eco-friendly. The results showed that Eh-AgNPs are promising antimicrobial agents that can be used in the development and formulation of new drugs to curb the menace of antimicrobial resistance in pathogenic and MDR microbes.
PubMed: 33917798
DOI: 10.3390/pharmaceutics13040511 -
Microbiology Spectrum Jun 2022Multidrug resistance (MDR) in Enterobacteriaceae including resistance to quinolones is rising worldwide. The plasmid-mediated quinolone resistance (PMQR) gene is...
Multidrug resistance (MDR) in Enterobacteriaceae including resistance to quinolones is rising worldwide. The plasmid-mediated quinolone resistance (PMQR) gene is prevalent in Enterobacteriaceae. However, the gene is rarely found in Enterobacter hormaechei (). Here, we reported one multidrug resistant strain M1 carrying the and genes. This study was to analyze the characteristics of MDR strain M1. The strain M1 was identified as Enterobacter cloacae complex by biochemical assay and 16S rRNA sequencing. The whole genome was sequenced by the Oxford Nanopore method. Taxonomy of the was based on multilocus sequence typing (MLST). The with the other antibiotic resistance genes were coexisted on IncF plasmid (pM1). Besides, the virulence factors associated with pathogenicity were also located on pM1. The gene was located between insertion element IS2A (upstream) and transposition element ISKra4 (downstream). The comparison result of IncF plasmids revealed that they had a common plasmid backbone. Susceptibility experiment revealed that the M1 showed extensive resistance to the clinical antimicrobials. The conjugation transfer was performed by filter membrane incubation method. The competition and plasmid stability assays suggested the host bacteria carrying had an energy burden. As far as we know, this is the first report that carrying was isolated from chicken feed. The chicken feed and poultry products could serve as a vehicle for these MDR bacteria, which could transfer between animals and humans through the food chain. We need to pay close attention to the epidemiology of and prevent their further dissemination. Enterobacter hormaechei is an opportunistic pathogen. It can cause infections in humans and animals. Plasmid-mediated quinolone resistance (PMQR) gene can be transferred intergenus, which is leading to increase the quinolone resistance levels in Enterobacteriaceae. Chicken feed could serve as a vehicle for the MDR . Therefore, antibiotic-resistance genes (ARGs) might be transferred to the intestinal flora after entering the gastrointestinal tract with the feed. Furthermore, antibiotic-resistant bacteria (ARB) were also excreted into environment with feces, posing a huge threat to public health. This requires us to monitor the ARB and antibiotic-resistant plasmids in the feed. Here, we demonstrated the characteristics of one MDR isolate from chicken feed. The plasmid carrying the gene is a conjugative plasmid with transferability. The presence of plasmid carrying antibiotic-resistance genes requires the maintenance of antibiotic pressure. In addition, the M1 belonged to new sequence type (ST). These data show the MDR M1 is a novel strain that requires our further research.
Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Anti-Bacterial Agents; Chickens; Enterobacter; Enterobacteriaceae; Microbial Sensitivity Tests; Multilocus Sequence Typing; Plasmids; Quinolones; RNA, Ribosomal, 16S
PubMed: 35467399
DOI: 10.1128/spectrum.02518-21 -
Frontiers in Cellular and Infection... 2022To explore the genetic characteristics of the IMP-4 and SFO-1 co-producing multidrug-resistant (MDR) clinical isolates, YQ13422hy and YQ13530hy.
PURPOSE
To explore the genetic characteristics of the IMP-4 and SFO-1 co-producing multidrug-resistant (MDR) clinical isolates, YQ13422hy and YQ13530hy.
METHODS
MALDI-TOF MS was used for species identification. Antibiotic resistance genes (ARGs) were tested by PCR and Sanger sequencing analysis. In addition to agar dilution, broth microdilution was used for antimicrobial susceptibility testing (AST). Whole-genome sequencing (WGS) analysis was conducted using the Illumina NovaSeq 6000 and Oxford Nanopore platforms. Annotation was performed by RAST on the genome. The phylogenetic tree was achieved using kSNP3.0. Plasmid characterization was conducted using S1-pulsed-field gel electrophoresis (S1-PFGE), Southern blotting, conjugation experiments, and whole genome sequencing (WGS). An in-depth study of the conjugation module was conducted using the OriTFinder website. The genetic context of and was analyzed using BLAST Ring Image Generator (BRIG) and Easyfig 2.3.
RESULTS
YQ13422hy and YQ13530hy, two MDR strains of ST51 harboring and , were identified. They were only sensitive to meropenem, amikacin and polymyxin B, and were resistant to cephalosporins, aztreonam, piperacillin/tazobactam and aminoglycosides, intermediate to imipenem. The genetic context surrounding was 5'CS--IS-In- -IS-. The integron of is In, which is the array of gene cassettes of 5'CS- . Phylogenetic analysis demonstrated that YQ13422hy and YQ13530hy belonged to the same small clusters with a high degree of homology.
CONCLUSION
This observation revealed the dissemination of the gene in in China. We found that and co-exist in MDR clinical isolates. This work showed a transferable IncN-type plasmid carrying the resistance gene in . We examined the potential resistance mechanisms of pYQ13422-IMP-4 and pYQ13422-SFO-1, along with their detailed genetic contexts.
Topics: Anti-Bacterial Agents; beta-Lactamases; Enterobacter; Phylogeny
PubMed: 36389152
DOI: 10.3389/fcimb.2022.998578 -
Infection and Drug Resistance 2020To investigate the occurrence and genetic characteristics of the -positive plasmid from a multidrug-resistant clinical isolate, L51.
PURPOSE
To investigate the occurrence and genetic characteristics of the -positive plasmid from a multidrug-resistant clinical isolate, L51.
METHODS
Species identification was determined by MALDI-TOF MS and Sanger sequencing. Antimicrobial susceptibility testing was performed by the agar dilution and broth microdilution. Whole-genome sequencing was conducted using Illumina HiSeq 4000-PE150 and PacBio Sequel platforms, and the genome was annotated by the RAST annotation server. The ANI analysis of genomes was performed using OAT. Phylogenetic reconstruction and analyses were performed using the Harvest suite based on the core-genome SNPs of 61 publicly available genomes.
RESULTS
The L51 genome consists of a 5,018,729 bp circular chromosome and a 343,918 bp conjugative IncHI2/2A plasmid pEHZJ1 encoding which surrounding genetic context was -ltrA-. A new sequence type (ST1103) was assigned for the isolate L51 which was resistant to cephalosporins, carbapenems, but sensitive to piperacillin-tazobactam, amikacin, tigecycline, trimethoprim-sulfamethoxazole and colistin. Phylogenetic analysis demonstrated that L51 belonged to the same subspecies as the reference strain SCEH020042, however 18,248 divergent SNP were identified. Resistance genes in pEHZJ1 including ' , , , , and .
CONCLUSION
In our study, we identified a conjugative IncHI2/2A plasmid carrying and in ST1103, a novel multidrug-resistant strain isolated from China, and describe the underlying resistance mechanisms of the strain and detailed genetic context of mega plasmid pEHZJ1.
PubMed: 32110070
DOI: 10.2147/IDR.S232514 -
Genomics Mar 2023Controlling eutrophication with algicidal bacteria is widely recognized as an effective solution. Here, an integrated transcriptomic and metabolomic approach was used to...
Controlling eutrophication with algicidal bacteria is widely recognized as an effective solution. Here, an integrated transcriptomic and metabolomic approach was used to elucidate the algicidal process of Enterobacter hormaechei F2, which exhibits substantial algicidal activity. At the transcriptome level, RNA sequencing (RNA-seq) identified 1104 differentially expressed genes in the algicidal process of the strain, thus indicating that amino acids, energy metabolism, and signaling-related genes were significantly activated during the algicidal process according to the Kyoto Encyclopedia of Genes and Genomes enrichment analysis. By analyzing the enriched amino acid and energy metabolism pathways using metabolomics, we identified 38 upregulated and 255 downregulated significantly changed metabolites in the algicidal process and an accumulation of B vitamins, peptides, and energy substances. The integrated analysis demonstrated that energy and amino acid metabolism, co-enzymes and vitamins, and bacterial chemotaxis are the most important pathways for the algicidal process of this strain, and metabolites from these pathways, such as thiomethyladenosine, isopentenyl diphosphate, hypoxanthine, xanthine, nicotinamide, and thiamine, all exhibited algicidal activity.
Topics: Transcriptome; Gene Expression Profiling; Metabolomics; Amino Acids
PubMed: 36796656
DOI: 10.1016/j.ygeno.2023.110586 -
Infection and Drug Resistance 2022With the spread of multiple drug-resistant bacteria, and have been detected in various bacteria worldwide. However, the simultaneous detection of and in has been...
PURPOSE
With the spread of multiple drug-resistant bacteria, and have been detected in various bacteria worldwide. However, the simultaneous detection of and in has been rarely reported. This study identified an strain carrying both and . We investigated the genetic characteristics of these two resistance genes in detail, elucidating various potential mechanisms by which they may be transmitted.
METHODS
Bacterial genomic features and possible origins were assessed by whole-genome sequencing (WGS) with Illumina and PacBio platforms and phylogenetic analysis. Subsequent investigations were performed, including antimicrobial susceptibility testing and multilocus sequence typing (MLST).
RESULTS
We isolated an strain DY1901 carrying both and from the sputum sample. Susceptibility testing showed that the isolate was multidrug-resistant. Multiple antibiotic resistance genes and virulence genes are widely distributed in DY1901. S1-PFGE, Southern blotting, and plasmid replicon typing showed that DY1901 carried four plasmids. The plasmid carrying was 259Kb in size and belonged to IncHI2, while the plasmid carrying was 45Kb in length and belonged to IncX3.
CONCLUSION
The strain isolated in this study has a broad antibiotic resistance spectrum, posing a challenge to clinical treatment. Plasmids carrying are fusion plasmids, and those taking NDM are widely disseminated in China, suggesting that we should conduct routine genomic surveillance on such plasmids to curb the spread of drug-resistant bacteria in the region.
PubMed: 36068833
DOI: 10.2147/IDR.S367073 -
Scientific Reports Jul 2023Persian walnut (Juglans regia) has a considerable economic importance worldwide. However, the vigor and vitality of walnut trees were heavily affected by bark canker...
Persian walnut (Juglans regia) has a considerable economic importance worldwide. However, the vigor and vitality of walnut trees were heavily affected by bark canker during the last few years. Irregular longitudinal cankers in the outer bark, stem tissue necrosis, and bleeding with black-colored exudates walnut trees were observed in Kermanshah, Hamedan, Markazi, Alborz, Isfahan, Qom, Semnan, and Razavi Khorasan provinces in western, central and eastern Iran during 2018 and 2019. A total of 150 symptomatic samples were collected from affected walnut trees in order to identify bacteria associated with walnut decline. Two-hundred sixty strains with a metallic green sheen were isolated on EMB-agar medium. The pathogenicity of all strains was proved by inoculating a suspension of the bacterial strains under the bark of immature walnut fruits cv. 'Hartley'. Ninety-five strains caused necrosis and a dark-colored region in the mesocarp around the inoculation site 14 days post-inoculation. Moreover, 12 representative strains induced necrotic and black-colored tissues in the bark of young green twigs of two-year old walnut seedling cv. 'Chandler'. The strains were classified into four categories based on conventional phenotypic characters confirmed with the 16S rRNA gene sequences. A phylogenetic tree based on the concatenated sequences of two housekeeping gene fragments, gyrB and infB, indicated that strains including I1, Q6, and S6 were grouped in a cluster with Gibbsiella quercinecans FBR97 as well as strains I2, I5, and KE6 were clustered with Rahnella victoriana FRB 225. Moreover, strains MR1, MR3, and MR5 were grouped with the Enterobacter hormaechei subsp. hoffmannii DSM 14563. The phylogenetic analyses based on the partial sequencing of housekeeping genes including fusA, pyrG, and leuS revealed that strains KH1, KH3, and KH7 belong to Citrobacter braakii species. To the best of our knowledge, this is the first report of C. braakii and E. hormaechei as plant pathogens and R. victoriana associated with walnut decline.
Topics: Juglans; Phylogeny; RNA, Ribosomal, 16S; Necrosis
PubMed: 37438442
DOI: 10.1038/s41598-023-38427-9 -
Journal of Applied Microbiology May 2014Enterobacter cloacae complex bacteria are of both clinical and environmental importance. Phenotypic methods are unable to distinguish between some of the species in this...
AIM
Enterobacter cloacae complex bacteria are of both clinical and environmental importance. Phenotypic methods are unable to distinguish between some of the species in this complex, which often renders their identification incomplete. The goal of this study was to develop molecular assays to identify Enterobacter hormaechei and Ent. cloacae genetic cluster III which are relatively frequently encountered in clinical material.
METHODS AND RESULTS
The molecular assays developed in this study are qPCR technology based and served to identify both Ent. hormaechei and Ent. cloacae genetic cluster III. qPCR results were compared to hsp60 sequence analysis. Most clinical isolates were assigned to Ent. hormaechei subsp. steigerwaltii and Ent. cloacae genetic cluster III. The latter was proportionately more frequently isolated from bloodstream infections than from other material (P < 0·05).
CONCLUSION
The qPCR assays detecting Ent. hormaechei and Ent. cloacae genetic cluster III demonstrated high sensitivity and specificity.
SIGNIFICANCE AND IMPACT OF THE STUDY
The presented qPCR assays allow accurate and rapid identification of clinical isolates of the Ent. cloacae complex. The improved identifications obtained can specifically assist analysis of Ent. hormaechei and Ent. cloacae genetic cluster III in nosocomial outbreaks and can promote rapid environmental monitoring. An association was observed between Ent. cloacae cluster III and systemic infection that deserves further attention.
Topics: Chaperonin 60; Enterobacter; Enterobacter cloacae; Real-Time Polymerase Chain Reaction; Sequence Analysis, DNA
PubMed: 24428402
DOI: 10.1111/jam.12439 -
Antimicrobial Agents and Chemotherapy Apr 2023We identified an ST133 extensively drug-resistant Enterobacter hormaechei, C210017, with increased virulence in the Galleria mellonella infection model. Genomic analysis...
We identified an ST133 extensively drug-resistant Enterobacter hormaechei, C210017, with increased virulence in the Galleria mellonella infection model. Genomic analysis suggested it carried antibiotic resistance genes and , and genes and encoding the virulence factor, siderophores. Comparative genomics of C210017 and the 178 ST133 strains in the database suggested they all belonged to serotype O3 and most strains (77.5%) carried the IncHI2 superplasmids associated with the resistance, virulence, and adaptation of the host strain.
Topics: Humans; Siderophores; Enterobacteriaceae Infections; Enterobacter; Anti-Bacterial Agents; Genomics
PubMed: 36920213
DOI: 10.1128/aac.01737-22 -
BMC Veterinary Research Jan 2022Enterobacter hormaechei is typically a opportunistic pathogenic bacterium in humans, and no pathological change of of Enterobacter hormaechei in diseased sheep has...
BACKGROUND
Enterobacter hormaechei is typically a opportunistic pathogenic bacterium in humans, and no pathological change of of Enterobacter hormaechei in diseased sheep has previously been documented.
CASE PRESENTATION
Three free-range, four-month-old female sheep were ill with respiratory disease and died three days after receiving treatment with ceftiofur sodium. A frozen lung sample of one sheep was studied using bacterium isolation, and lung samples of the other two sheep were collected and analyzed by histopathological examination and bacterium isolation. The 16S rRNA gene sequences and biochemical characteristics of the isolates were analyzed. All results showed the isolated strain to be Enterobacter hormaechei. Phylogenetic analysis of the 16S rRNA sequence showed three representative strains were most closely related to the strains isolated from calf. Antimicrobial sensitivity tests indicated that no sensitivity to the β-lactam antimicrobials involved in treatment of sheep respiratory disease in China. Detection of the genes responsible for β-lactam resistance showed that all three isolates from sheep harbor bla and bla Interstitial pneumonia, bronchial epithelial cells shedding, and massive mucous secretion were observed in the lung histopathological sections. Immunohistochemical staining showed that specific staining was mainly limited to the alveoli and alveolar septum.
CONCLUSIONS
This appears to be the first report of pathological changes in lungs of sheep with respiratory disease and death associated with Enterobacter hormaechei.
Topics: Animals; Anti-Bacterial Agents; Enterobacter; Enterobacteriaceae Infections; Fatal Outcome; Female; Microbial Sensitivity Tests; Phylogeny; RNA, Ribosomal, 16S; Sheep; Sheep Diseases
PubMed: 35081969
DOI: 10.1186/s12917-022-03157-z