-
Pathogens (Basel, Switzerland) Oct 2021(1) Background: () is a gram-negative bacillus of the Enterobacteriaceae family, which is uncommonly isolated from clinical specimens. is considered as an aquatic...
(1) Background: () is a gram-negative bacillus of the Enterobacteriaceae family, which is uncommonly isolated from clinical specimens. is considered as an aquatic opportunistic pathogen and most of the human infections are polymicrobial and usually occur in immunocompromised hosts. (2) Methods: In this retrospective study, we included all strains since the introduction of MALDI-TOF MS in the Microbiology Department of Hospital, France (from 1 March 2015 to 31 July 2019). We studied demographic characteristics, comorbidities, characteristics of the current infection and outcome as well as antimicrobial susceptibility testing in all isolates. (3) Results: A total of 8 samples were identified (in 6 patients (4M/2F), with a recurrent infection in 2 patients). The patients' mean age was 66.2 years (range: 19-84). All patients were considered as immunocompetent, except a peritoneal dialysis patient with kidney transplantation. An exposition to an aquatic environment was identified in one patient. The most prevalent clinical feature was catheter-associated male urinary tract infection (in 3 cases) followed by ventilator-associated pneumonia (in 2 cases). One of 6 patients presented bacteremia. was part of a polymicrobial infection in 4 patients. The isolates showed a high susceptibility to all tested antibiotics, except one strain, which was resistant to fosfomycin. All patients with infection were treated with antibiotics with a favorable outcome. (4) Conclusion: This study confirms the pathogenicity of , even in immunocompetent patients, with a high susceptibility to antibiotics.
PubMed: 34832555
DOI: 10.3390/pathogens10111399 -
Revista Chilena de Infectologia :... Jun 2022
Topics: Enterobacteriaceae; Enterobacteriaceae Infections; Humans
PubMed: 36156693
DOI: 10.4067/s0716-10182022000200319 -
Genetics and Molecular Biology 2021Plant growth-promoting bacteria are ecological alternatives for fertilization, mainly for gramineous. Since plant x bacteria interaction is genotype and strain...
Plant growth-promoting bacteria are ecological alternatives for fertilization, mainly for gramineous. Since plant x bacteria interaction is genotype and strain dependent, searching for new strains may contribute to the development of new biofertilizers. We aim to characterize plant growth-promoting capacity of Leclercia adecarboxylata strain Palotina, formerly isolated by our group in corn. A single isolated colony was taken and its genome was sequenced using Illumina technology. The whole genome was compared to other Leclercia adecarboxylata strains, and their biological and growth-promoting traits, such as P solubilization and auxin production, were tested. Following that, a 4.8 Mb genome of L. adecarboxylata strain Palotina was assembled and the functional annotation was carried out. This paper is the first to report the genes associated with plant growth promotion demonstrating in vitro indole acid production by this strain. These results project the endophyte as a potential biofertilizer for further commercial exploitation.
PubMed: 33503198
DOI: 10.1590/1678-4685-GMB-2020-0130 -
Microbial Cell Factories Dec 2022The biosynthesis of silver nanoparticles (AgNPs) is an area of interest for researchers due to its eco-friendly approach. The use of biological approaches provides a...
Extracellular biosynthesis, OVAT/statistical optimization, and characterization of silver nanoparticles (AgNPs) using Leclercia adecarboxylata THHM and its antimicrobial activity.
BACKGROUND
The biosynthesis of silver nanoparticles (AgNPs) is an area of interest for researchers due to its eco-friendly approach. The use of biological approaches provides a clean and promising alternative process for the synthesis of AgNPs. We used for the first time the supernatant of Leclercia adecarboxylata THHM under optimal conditions to produce AgNPs with an acceptable antimicrobial activity against important clinical pathogens.
RESULTS
In this study, soil bacteria from different locations were isolated and screened for their potential to form AgNPs. The selected isolate, which was found to have the ability to biosynthesize AgNPs, was identified by molecular methods as Leclercia adecarboxylata THHM and its 16S rRNA gene was deposited in GenBank under the accession number OK605882. Different conditions were screened for the maximum production of AgNPs by the selected bacteria. Five independent variables were investigated through optimizations using one variable at a time (OVAT) and the Plackett-Burman experimental design (PBD). The overall optimal parameters for enhancing the biosynthesis of AgNPs using the supernatant of Leclercia adecarboxylata THHM as a novel organism were at an incubation time of 72.0 h, a concentration of 1.5 mM silver nitrate, a temperature of 40.0 °C, a pH of 7.0, and a supernatant concentration of 30% (v/v) under illumination conditions. The biosynthesized AgNPs have been characterized by UV-visible spectroscopy (UV-Vis), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). The biosynthesized AgNPs showed an absorption peak at 423 nm, spherical shape, and an average particle size of 17.43 nm. FTIR shows the bands at 3321.50, 2160.15, and 1636.33 cm corresponding to the binding vibrations of amine, alkyne nitrile, and primary amine bands, respectively. The biosynthesized AgNPs showed antimicrobial activity against a variety of microbial pathogens of medical importance. Using resazurin-based microtiter dilution, the minimum inhibitory concentration (MIC) values for AgNPs were 500 µg/mL for all microbial pathogens except for Klebsiella pneumoniae ATCC13883, which has a higher MIC value of 1000 µg/mL.
CONCLUSIONS
The obtained data revealed the successful green production of AgNPs using the supernatant of Leclercia adecarboxylata THHM that can be effectively used as an antimicrobial agent against most human pathogenic microbes.
Topics: Humans; Metal Nanoparticles; Anti-Bacterial Agents; RNA, Ribosomal, 16S; Silver; Anti-Infective Agents; Bacteria
PubMed: 36581886
DOI: 10.1186/s12934-022-01998-9 -
Microbiology (Reading, England) Apr 2024is a member of Enterobacterales, often considered an opportunistic pathogen. Recent reports have highlighted as an emerging pathogen harbouring virulence and...
is a member of Enterobacterales, often considered an opportunistic pathogen. Recent reports have highlighted as an emerging pathogen harbouring virulence and resistance determinants. Little information exists on virulence and resistance determinants in strains isolated from environmental, food, and clinical samples. To determine the presence of resistance and virulence determinants and plasmid features in strains isolated from environmental, food, and clinical samples, as well as their phylogenetic relationship. All strains tested showed resistance to β-lactams and quinolones but were sensitive to aminoglycosides and nitrofurans. However, even though fosfomycin resistance is considered a characteristic trait of , the resistance phenotype was only observed in 50 % of the strains; was the most prevalent BLEE gene (70 %), while the quinolone gene was observed in 60 % of the strains. Virulence genes were differentially observed in the strains, with adhesion-related genes being the most abundant, followed by toxin genes. Finally, all strains carried one to seven plasmid bands ranging from 7 to 125 kbps and harboured several plasmid addiction systems, such as ParDE, VagCD, and CcdAB in 80 % of the strains. is an important emerging pathogen that may harbour resistance and virulence genes. Additionally, it has mobilizable genetic elements that may contribute to the dissemination of genetic determinants to other bacterial genera.
Topics: Anti-Bacterial Agents; Plasmids; Virulence; Microbial Sensitivity Tests; Enterobacteriaceae; Phylogeny; Virulence Factors; Humans; Enterobacteriaceae Infections; Phenotype; Drug Resistance, Bacterial; Quinolones; beta-Lactams; Drug Resistance, Multiple, Bacterial; Food Microbiology
PubMed: 38661713
DOI: 10.1099/mic.0.001457 -
World Journal of Clinical Cases Oct 2022Infective endocarditis (IE) is a rare disease with a high mortality rate. () is a movable Gram-negative bacillus of enterobacteriaceae, and it can rarely be a pathogen...
BACKGROUND
Infective endocarditis (IE) is a rare disease with a high mortality rate. () is a movable Gram-negative bacillus of enterobacteriaceae, and it can rarely be a pathogen which often affects immunodeficient patients. There are about three cases of immunocompetent patients with monomicrobial infection. There are only three reported cases of IE caused by in the world. The mitral valve is often affected in IE, and the prognosis for IE with mitral valve lesions is often poor.
CASE SUMMARY
A 51-year-old man was found to have moderate to severe mitral stenosis on echocardiography. He came to our Cardiothoracic Surgery Department for surgical management. A diastolic murmur was heard on auscultation of the heart in the mitral region. On the second day of hospitalisation, he presented with slurred speech, reduced muscle strength in the left limb, and acute cerebral infarction on cranial computed tomography. Surgical treatment was decided to postpone. On the ninth day of admission, the patient developed a sudden high fever and shock and was transferred to the Cardiac Intensive Care Unit, where echocardiogram revealed an anterior mitral valve leaflet vegetation. After empirical anti-infective treatment with vancomycin (1g q12h), an emergency valve replacement was performed. Bacterial culture identified . Anti-infective treatment with piperacillin-tazobactam (4.5g q8h) was added for 4 wk. Follow-up echocardiography showed normal bioprosthetic valve function after mitral valve replacement.
CONCLUSION
We report the first case of IE in China, and clinicians should pay attention to this pathogen.
PubMed: 36312476
DOI: 10.12998/wjcc.v10.i29.10670 -
Biology Nov 2021Drought or water stress is a limiting factor that hampers the growth and yield of edible crops. Drought-tolerant plant growth-promoting rhizobacteria (PGPR) can mitigate...
Drought or water stress is a limiting factor that hampers the growth and yield of edible crops. Drought-tolerant plant growth-promoting rhizobacteria (PGPR) can mitigate water stress in crops by synthesizing multiple bioactive molecules. Here, strain PAB19 recovered from rhizospheric soil was biochemically and molecularly characterized, and identified as sp./ (MT672579.1). Strain PAB19 tolerated an exceptionally high level of drought (18% PEG-6000) and produced indole-3-acetic acid (176.2 ± 5.6 µg mL), ACC deaminase (56.6 ± 5.0 µg mL), salicylic acid (42.5 ± 3.0 µg mL), 2,3-dihydroxy benzoic acid (DHBA) (44.3 ± 2.3 µg mL), exopolysaccharide (204 ± 14.7 µg mL), alginate (82.3 ± 6.5 µg mL), and solubilized tricalcium phosphate (98.3 ± 3.5 µg mL), in the presence of 15% polyethylene glycol. Furthermore, strain PAB19 alleviated water stress and significantly ( ≤ 0.05) improved the overall growth and biochemical attributes of (L.) R. Wilczek. For instance, at 2% PEG stress, PAB19 inoculation maximally increased germination, root dry biomass, leaf carotenoid content, nodule biomass, leghaemoglobin (LHb) content, leaf water potential (ΨL), membrane stability index (MSI), and pod yield by 10%, 7%, 14%, 38%, 9%, 17%, 11%, and 11%, respectively, over un-inoculated plants. Additionally, PAB19 inoculation reduced two stressor metabolites, proline and malondialdehyde, and antioxidant enzymes (POD, SOD, CAT, and GR) levels in foliage in water stress conditions. Following inoculation of strain PAB19 with 15% PEG in soil, stomatal conductance, intercellular CO concentration, transpiration rate, water vapor deficit, intrinsic water use efficiency, and photosynthetic rate were significantly improved by 12%, 8%, 42%, 10%, 9% and 16%, respectively. Rhizospheric CFU counts of PAB19 were 2.33 and 2.11 log CFU g after treatment with 15% PEG solution and 8.46 and 6.67 log CFU g for untreated controls at 40 and 80 DAS, respectively. Conclusively, this study suggests the potential of sp./ PAB19 to alleviate water stress by improving the biological and biochemical features and of under water-deficit conditions.
PubMed: 34827142
DOI: 10.3390/biology10111149 -
Journal of Global Antimicrobial... Jun 2023The aim of this study was to perform a genomic investigation of a multiple fluoroquinolone-resistant Leclercia adecarboxylata strain isolated from a synanthropic pigeon...
OBJECTIVES
The aim of this study was to perform a genomic investigation of a multiple fluoroquinolone-resistant Leclercia adecarboxylata strain isolated from a synanthropic pigeon in São Paulo, Brazil.
METHODS
Whole-genome sequencing was performed using an Illumina platform, and in silico deep analyses of the resistome were performed. Comparative phylogenomics was conducted using a global collection of publicly available genomes of L. adecarboxylata strains isolated from human and animal hosts.
RESULTS
L. adecarboxylata strain P62P1 displayed resistance to human (norfloxacin, ofloxacin, ciprofloxacin, and levofloxacin) and veterinary (enrofloxacin) fluoroquinolones. This multiple quinolone-resistant profile was associated with mutations in the gyrA (S83I) and parC (S80I) genes and the presence of the qnrS gene within an ISKpn19-orf-qnrS1-ΔIS3-bla module, previously identified in L. adecarboxylata strains isolated from pig feed and faeces in China. Genes associated with arsenic, silver, copper, and mercury resistance were also predicted. Phylogenomic analysis revealed clustering (378-496 single nucleotide polymorphism differences) with two L. adecarboxylata strains isolated from human and fish sources in China and Portugal, respectively.
CONCLUSIONS
L. adecarboxylata is a Gram-negative bacterium of the Enterobacterales order and is considered an emergent opportunistic pathogen. Since L. adecarboxylata has adapted to human and animal hosts, genomic surveillance is highly recommended, in order to identify the emergence and spread of resistant lineages and high-risk clones. In this regard, this study provides genomic data that can help clarify the role of synanthropic animals in the dissemination of clinically relevant L. adecarboxylata within a One Health context.
Topics: Humans; Animals; Swine; Fluoroquinolones; Columbidae; Brazil; DNA Gyrase; Microbial Sensitivity Tests; Genomics
PubMed: 37098384
DOI: 10.1016/j.jgar.2023.04.013 -
BMC Microbiology Dec 2022Acute Oak Decline (AOD) is a decline disease first reported on native oaks in the UK, but in recent years reports from further afield such as Europe and the Middle East,...
Description of a novel species of Leclercia, Leclercia tamurae sp. nov. and proposal of a novel genus Silvania gen. nov. containing two novel species Silvania hatchlandensis sp. nov. and Silvania confinis sp. nov. isolated from the rhizosphere of oak.
BACKGROUND
Acute Oak Decline (AOD) is a decline disease first reported on native oaks in the UK, but in recent years reports from further afield such as Europe and the Middle East, indicate that the distribution and host range is increasing at an alarming rate. The stem weeping symptoms of the disease partially develop due to polymicrobial-host interaction, caused by several members of the order Enterobacterales. While investigating the rhizosphere soil of AOD-unaffected trees, termed 'healthy' trees, and diseased oaks suffering from Acute Oak Decline (AOD), an enrichment method designed for enhanced recovery of Enterobacterales led to the recovery of several isolates that could not be classified as any existing species. These isolates showed a close relationship to the genus Leclercia, of which both species are of clinical importance, but the type species Leclercia adecarboxylata also displays plant growth-promoting properties in the rhizosphere.
RESULTS
Partial sequencing of four housekeeping genes revealed similarity to the genus Leclercia with varying degrees of relatedness. As such a complete polyphasic approach was used to determine the true taxonomic position of these isolates. This involved whole genome sequencing, phylogenomic analysis, phylogenetic analysis of both the 16S rRNA and four housekeeping gene sequences, combined with phenotypic testing and fatty acid analysis. Both the phylogenomic and phylogenetic analyses separated the isolates into four clusters, two of which were contained in the Leclercia clade. The remaining two clusters formed a separate lineage far removed from any currently defined species. Further investigation into the role of the isolates as plant growth-promoting bacteria as well as plant pathogens was investigated computationally, revealing a number of plant growth-promoting traits as well as virulence genes related to motility, adhesion and immune modulation.
CONCLUSION
Based on the genotypic and phenotypic data presented here, these isolates could be differentiated from each other and their closest neighbours. As such we propose the description of Leclercia tamurae sp. nov. (type strain H6S3 = LMG 32609 = CCUG 76176), Silvania gen. nov., Silvania hatchlandensis sp. nov. (type strain H19S6 = LMG 32608 = CCUG 76185) and Silvania confinis sp. nov. (type strain H4N4 = LMG 32607 = CCUG 76175). Due to their interesting protein annotations and alignments, these species warrant further investigation for their role in relation to plant health.
Topics: Quercus; Rhizosphere; Phylogeny; RNA, Ribosomal, 16S; Enterobacteriaceae; Gammaproteobacteria
PubMed: 36460957
DOI: 10.1186/s12866-022-02711-x -
The American Journal of Case Reports Mar 2021BACKGROUND Leclercia adecarboxylata is a gram-negative rod, which is normally found in water and food. It is an emerging pathogen that affects immunocompromised...
BACKGROUND Leclercia adecarboxylata is a gram-negative rod, which is normally found in water and food. It is an emerging pathogen that affects immunocompromised patients, including patients with hematological malignancies or those receiving chemotherapy. Generally, L. adecarboxylata is considered a low-virulence pathogen with an excellent susceptibility profile, but some strains may be resistant to multiple antibiotics, such as b-lactams. Moreover, L. adecarboxylata is usually isolated as a part of polymicrobial cultures in immunocompetent individuals, but there have been cases where it was the only isolate. CASE REPORT A 74-year-old woman who was non-immunosuppressed and had multiple comorbidities was admitted with acute decompensated heart failure due to pneumonia. She was treated with multiple courses of antibiotics including amoxicillin-clavulanate and ciprofloxacin for pneumonia, but her infection worsened, and she had cardiopulmonary arrest. After resuscitation, she was stable for several days but suddenly became confused and hypotensive. The septic screen showed L. adecarboxylata bacteremia without a clear source, which was treated successfully with meropenem for 14 days. After the meropenem course, the patient developed diarrhea and was found to have severe Clostridium difficile infection. She did not respond to oral vancomycin and intravenous metronidazole and died. CONCLUSIONS This case illustrated an infection in a non-immunosuppressed individual by an organism that is considered an opportunistic pathogen, mainly affecting immunocompromised patients. The patient's blood culture grew L. adecarboxylata, which was sensitive to all antibiotics but resolved with meropenem treatment. Owing to increasing L. adecarboxylata infections, we recommend further studies to understand the organism's pathogenesis, risk factors, and resistance pattern.
Topics: Aged; Anti-Bacterial Agents; Bacteremia; Enterobacteriaceae; Enterobacteriaceae Infections; Female; Humans; Immunocompromised Host
PubMed: 33782375
DOI: 10.12659/AJCR.929537