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The Lancet. Microbe Jun 2024Morganella spp are opportunistic pathogens involved in various infections. Intrinsic resistance to multiple antibiotics (including colistin) combined with the emergence... (Comparative Study)
Comparative Study
BACKGROUND
Morganella spp are opportunistic pathogens involved in various infections. Intrinsic resistance to multiple antibiotics (including colistin) combined with the emergence of carbapenemase producers reduces the number of active antimicrobials. The aim of this study was to characterise genetic features related to the spread of carbapenem-resistant Morganella spp.
METHODS
This comparative genomic study included extensively drug-resistant Morganella spp isolates collected between Jan 1, 2013, and March 1, 2021, by the French National Reference Center (NRC; n=68) and European antimicrobial resistance reference centres in seven European countries (n=104), as well as one isolate from Canada, two reference strains from the Pasteur Institute collection (Paris, France), and two colistin-susceptible isolates from Bicêtre Hospital (Kremlin-Bicêtre, France). The isolates were characterised by whole-genome sequencing, antimicrobial susceptibility testing, and biochemical tests. Complete genomes from GenBank (n=103) were also included for genomic analysis, including phylogeny and determination of core genomes and resistomes. Genetic distance between different species or subspecies was performed using average nucleotide identity (ANI). Intrinsic resistance mechanisms to polymyxins were investigated by combining genetic analysis with mass spectrometry on lipid A.
FINDINGS
Distance analysis by ANI of 275 isolates identified three groups: Morganella psychrotolerans, Morganella morganii subspecies sibonii, and M morganii subspecies morganii, and a core genome maximum likelihood phylogenetic tree showed that the M morganii isolates can be separated into four subpopulations. On the basis of these findings and of phenotypic divergences between isolates, we propose a modified taxonomy for the Morganella genus including four species, Morganella psychrotolerans, Morganella sibonii, Morganella morganii, and a new species represented by a unique environmental isolate. We propose that M morganii include two subspecies: M morganii subspecies morganii (the most prevalent) and M morganii subspecies intermedius. This modified taxonomy was supported by a difference in intrinsic resistance to tetracycline and conservation of metabolic pathways such as trehalose assimilation, both only present in M sibonii. Carbapenemase producers were mostly identified among five high-risk clones of M morganii subspecies morganii. The most prevalent carbapenemase corresponded to NDM-1, followed by KPC-2, and OXA-48. A cefepime-zidebactam combination was the most potent antimicrobial against the 172 extensively drug-resistant Morganella spp isolates in our collection from different European countries, which includes metallo-β-lactamase producers. Lipid A analysis showed that the intrinsic resistance to colistin was associated with the presence of L-ARA4N on lipid A.
INTERPRETATION
This global characterisation of, to our knowledge, the widest collection of extensively drug-resistant Morganella spp highlights the need to clarify the taxonomy and decipher intrinsic resistance mechanisms, and paves the way for further genomic comparisons.
FUNDING
None.
Topics: Bacterial Proteins; beta-Lactamases; Anti-Bacterial Agents; Genome, Bacterial; Microbial Sensitivity Tests; Humans; Phylogeny; Enterobacteriaceae Infections; Morganella; Genomics; Whole Genome Sequencing; Europe; Carbapenems; Drug Resistance, Multiple, Bacterial; Colistin
PubMed: 38677305
DOI: 10.1016/S2666-5247(23)00407-X -
Nature Communications Jun 2020Toxin complex (Tc) toxins are virulence factors of pathogenic bacteria. Tcs are composed of three subunits: TcA, TcB and TcC. TcA facilitates receptor-toxin interaction...
Toxin complex (Tc) toxins are virulence factors of pathogenic bacteria. Tcs are composed of three subunits: TcA, TcB and TcC. TcA facilitates receptor-toxin interaction and membrane permeation, TcB and TcC form a toxin-encapsulating cocoon. While the mechanisms of holotoxin assembly and pore formation have been described, little is known about receptor binding of TcAs. Here, we identify heparins/heparan sulfates and Lewis antigens as receptors for different TcAs from insect and human pathogens. Glycan array screening reveals that all tested TcAs bind negatively charged heparins. Cryo-EM structures of Morganella morganii TcdA4 and Xenorhabdus nematophila XptA1 reveal that heparins/heparan sulfates unexpectedly bind to different regions of the shell domain, including receptor-binding domains. In addition, Photorhabdus luminescens TcdA1 binds to Lewis antigens with micromolar affinity. Here, the glycan interacts with the receptor-binding domain D of the toxin. Our results suggest a glycan dependent association mechanism of Tc toxins on the host cell surface.
Topics: Animals; Bacterial Toxins; Binding Sites; Cell Adhesion; Cell Membrane; HEK293 Cells; Heparin; Humans; Insecta; Lewis X Antigen; Models, Molecular; Molecular Docking Simulation; Morganella morganii; Photorhabdus; Polysaccharides; Xenorhabdus
PubMed: 32483155
DOI: 10.1038/s41467-020-16536-7 -
Cureus Jun 2023Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae threaten infection treatment globally. This study aims to assess ESBLs-E prevalence and...
BACKGROUND
Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae threaten infection treatment globally. This study aims to assess ESBLs-E prevalence and multidrug-resistant organisms (MDR) in clinical specimens from Tabuk, KSA.
METHODS
A cross-sectional research was carried out in March-May 2023. A collective of 90 Enterobacteriaceae isolates were identified from clinical specimens. The specimen was identified by standard methods. The Enterobacteriaceae member was screed for ESBL production by screening and confirmatory as per the Clinical and Laboratory Standards Institute (CLSI).
RESULT
was the most common isolate, followed by , , , and . Among the sample, the majority of isolates were from urine (47.8%) followed by pus (25.6%) and the least from other body fluids (6.7%). The showed the highest average antibiotic resistance (73.7%) among all the antibiotics used followed by (70.4%), (70%), (69.8%), and (69.4% both), and (68.8%). There was a 41.2% average reduction in ESBL positivity from phenotypic to confirmatory test results. The highest reduction was observed among (66.7%) and the least was observed in (17.1%).
CONCLUSION
Most of the ESBL-producing isolates were found mainly in blood and urine samples. The most frequent ESBL-producing Enterobacteriaceae were and . The best options for treating Enterobacteriaceae that produce ESBL are Amoxicillin, Amikacin, and Cefoxitin. ESBL-producing isotopes showed a high resistance rate to cefepime and cefotaxime compared to non-ESBL producers. It is of utmost importance to implement reliable infection control measures in healthcare institutions nationwide.
PubMed: 37431354
DOI: 10.7759/cureus.40183 -
Antibiotics (Basel, Switzerland) May 2024Carbapenemase-producing spp. , , spp., and (CP-ESCPM) are increasingly identified as causative agents of nosocomial infections but are still not under systematic...
Carbapenemase-producing spp. , , spp., and (CP-ESCPM) are increasingly identified as causative agents of nosocomial infections but are still not under systematic genomic surveillance. In this study, using a combination of whole-genome sequencing and conjugation experiments, we sought to elucidate the genomic characteristics and transferability of resistance genes in clinical CP-ESCPM isolates from Bulgaria. Among the 36 sequenced isolates, NDM-1 (12/36), VIM-4 (11/36), VIM-86 (8/36), and OXA-48 (7/36) carbapenemases were identified; two isolates carried both NDM-1 and VIM-86. The majority of carbapenemase genes were found on self-conjugative plasmids. IncL plasmids were responsible for the spread of OXA-48 among , , and . IncM2 plasmids were generally associated with the spread of NDM-1 in and , and also of VIM-4 in . IncC plasmids were involved in the spread of the recently described VIM-86 in isolates. IncC plasmids carrying and were observed too. was also detected on IncX3 in and on IncT plasmid in . The significant resistance transfer rates we observed highlight the role of the ESCPM group as a reservoir of resistance determinants and stress the need for strengthening infection control measures.
PubMed: 38786183
DOI: 10.3390/antibiotics13050455 -
Antibiotics (Basel, Switzerland) Jul 2023NDM carbapenemase-encoding genes disseminate commonly among Enterobacterales through transferable plasmids carrying additional resistance determinants. Apart from the...
NDM carbapenemase-encoding genes disseminate commonly among Enterobacterales through transferable plasmids carrying additional resistance determinants. Apart from the intra-species dissemination, the inter-species exchange of plasmids seems to play an additional important role in the spread of . We here present the genetics related to the isolation of three species (, , and ) harboring the gene from a single patient in Greece. Bacterial identification and antimicrobial susceptibility testing were performed using the Vitek2. Whole genome sequencing and bioinformatic tools were used to identify resistance genes and plasmids. harboring plasmids were found in all three isolates. Moreover, the plasmid constructs of the respective incomplete or circular contigs showed that the and its neighboring genes form a cluster that was found in all isolates. Our microbiological findings, together with the patient's history, suggest the in vivo transfer of the -containing cluster through three different species in a single patient.
PubMed: 37508302
DOI: 10.3390/antibiotics12071206 -
Antimicrobial Agents and Chemotherapy Mar 2021
Topics: Enterobacteriaceae Infections; Genome, Bacterial; Genomic Islands; Humans; Morganella morganii
PubMed: 33468469
DOI: 10.1128/AAC.02524-20 -
Genes Jun 2023is a Gram-negative opportunistic pathogen inherently resistant to colistin. This species causes various clinical and community-acquired infections. This study...
is a Gram-negative opportunistic pathogen inherently resistant to colistin. This species causes various clinical and community-acquired infections. This study investigated the virulence factors, resistance mechanisms, functional pathways, and comparative genomic analysis of strain UM869 with 79 publicly available genomes. The multidrug resistance strain UM869 harbored 65 genes associated with 30 virulence factors, including efflux pump, hemolysin, urease, adherence, toxin, and endotoxin. Additionally, this strain contained 11 genes related to target alteration, antibiotic inactivation, and efflux resistance mechanisms. Further, the comparative genomic study revealed a high genetic relatedness (98.37%) among the genomes, possibly due to the dissemination of genes between adjoining countries. The core proteome of 79 genomes contains the 2692 core, including 2447 single-copy orthologues. Among them, six were associated with resistance to major antibiotic classes manifested through antibiotic target alteration (, ) and antibiotic efflux (, , ; ; ). Similarly, 47 core orthologues were annotated to 27 virulence factors. Moreover, mostly core orthologues were mapped to transporters ( = 576), two-component systems ( = 148), transcription factors ( = 117), ribosomes ( = 114), and quorum sensing ( = 77). The presence of diversity in serotypes (type 2, 3, 6, 8, and 11) and variation in gene content adds to the pathogenicity, making them more difficult to treat. This study highlights the genetic similarity among the genomes of and their restricted emergence, mostly in Asian countries, in addition to their growing pathogenicity and resistance. However, steps must be taken to undertake large-scale molecular surveillance and to direct suitable therapeutic interventions.
Topics: Virulence; Genome, Bacterial; Anti-Bacterial Agents; Virulence Factors; Drug Resistance, Multiple, Bacterial; Genomics
PubMed: 37372459
DOI: 10.3390/genes14061279 -
Cureus Sep 2023is an opportunistic Gram-negative bacillus commonly found in the human gastrointestinal tract and the environment. In adults, it is often associated with nosocomial...
is an opportunistic Gram-negative bacillus commonly found in the human gastrointestinal tract and the environment. In adults, it is often associated with nosocomial infections, primarily surgical wound infections, urinary tract infections, and hepatobiliary infections. It is a rare cause of early-onset neonatal sepsis, with fewer than 15 reported cases in the literature. The authors aim to present a case of a low birth weight preterm born at 28 weeks' gestation, who developed early-onset neonatal sepsis due to . We successfully treated the infection using a combination of third-generation cephalosporin and aminoglycoside, and in this report, we explain the rationale behind employing this antibiotic therapy.
PubMed: 37868540
DOI: 10.7759/cureus.45600 -
BMC Genomics Aug 2020M. morganii is a bacterium frequently associated with urinary infections in humans. While many human strains are sequenced, only the genomes of few poultry strains are...
BACKGROUND
M. morganii is a bacterium frequently associated with urinary infections in humans. While many human strains are sequenced, only the genomes of few poultry strains are available. Here, we performed a detailed characterization of five highly resistant Morganella morganii strains isolated in association with Escherichia coli from diseased domestic Austrian poultry flocks, namely geese, turkeys and chicken layers. Additionally, we sequenced the genomes of these strains by NGS and analyzed phylogenetic clustering, resistance and virulence genes in the context of host-specificity.
RESULTS
Two strains were identified to be Extended Spectrum Beta Lactamase (ESBL) and one as AmpC beta-lactamases (AMP-C) phenotype, while two were ESBL negative. By integrating the genome sequences of these five poultry strains with all the available M. morganii genomes, we constructed a phylogenetic tree that clearly separates the Morganella genus into two clusters (M1 and M2), which approximately reflect the proposed subspecies classification (morganii and sibonii). Additionally, we found no association between phylogenetic structure and host, suggesting interspecies transmission. All five poultry strains contained genes for resistance to aminocoumarins, beta-lactams, colistin, elfamycins, fluoroquinolones, phenicol, rifampin and tetracycline. A comparative genomics analysis of virulence genes showed acquisition of novel virulence genes involved in secretion system and adherence in cluster M2. We showed that some of these genes were acquired by horizontal gene transfer from closely related Morganellaceae species and propose that novel virulence genes could be responsible for expansion of tissue tropism in M. morganii. Finally, we detected variability in copy number and high sequence divergence in toxin genes and provided evidence for positive selection in insecticidal toxins genes, likely reflecting host-related adaptations.
CONCLUSIONS
In summary, this study describes i) the first isolation and characterization of M. morganii from goose and turkey, ii) a large-scale genetic analysis of M. morganii and an attempt to generate a global picture of the M. morganii intraspecific phylogenetic structure.
Topics: Animals; Anti-Bacterial Agents; Humans; Morganella morganii; Phylogeny; Poultry; Virulence; beta-Lactamases; beta-Lactams
PubMed: 32831012
DOI: 10.1186/s12864-020-07001-2 -
Surgical Neurology International 2024is a Gram-negative enteric rod found in the intestinal tracts of humans, mammals, and reptiles as normal flora. It is highly implicated in urinary tract infections,...
BACKGROUND
is a Gram-negative enteric rod found in the intestinal tracts of humans, mammals, and reptiles as normal flora. It is highly implicated in urinary tract infections, wound infections, and septicemia. The cerebral nervous system, especially brain abscess attributed to , remains extremely rare. To the best of the author's knowledge, only eight documented cerebral brain abscesses caused by have been reported in the literature.
CASE DESCRIPTION
A 48-year-old man presented with headache, fever, and irritability two months after endoscopic endonasal repair of the cranial base defect. Following imaging studies, a large left frontal abscess was found. The patient underwent a fine-needle aspiration through a burr hole following antimicrobial therapy.
CONCLUSION
We report this case to create awareness among neurosurgeons and microbiologists that , even though uncommon, is a cause of cerebral brain abscess. Prompt surgical management and appropriate antimicrobial therapy is the treatment of choice.
PubMed: 38344080
DOI: 10.25259/SNI_759_2023