Tracing the possible evolutionary trends of Morganella morganii: insights from molecular epidemiology and phylogenetic analysis.

Morganella morganii, encompassing two subspecies, subsp. morganii and subsp. sibonii, is a common opportunistic pathogen, notable for intrinsic resistance to multiple antimicrobial agents. Despite its clinical significance, research into the potential evolutionary dynamics of M. morganii remains limited. This study involved the analysis of genome sequences from 431 M. morganii isolates, comprising 206 isolates that cause host infections, obtained from this study and 225 from the NCBI genome data sets. A diverse array of antimicrobial resistance genes (ARGs) was identified in M. morganii isolates, including mcr-1, tet(X4), tmexCD-toprJ, and various carbapenemase genes. In addition, a novel blaKPC-2-bearing plasmid with demonstrated conjugative capability was discovered in M. morganii. The majority of virulence-related genes (VRGs), except for the hlyCABD gene cluster, were found in almost all M. morganii. Three novel genospecies of M. morganii were identified, designated as M. chanii, M. variant1, and M. variant2. Compared to M. sibonii, M. chanii genospecies possessed a greater number of flagellar-related genes, typically located within mobile genetic elements (MGEs), suggesting potential for better environmental adaptability. Phylogenetic analysis further disclosed that M. morganii was divided into 12 sequence clusters (SCs). Particularly, SC9 harbored an elevated abundance of ARGs and VRGs, mainly toxin-related genes, and was associated with a higher presence of MGEs compared to non-SC9 strains. The collective findings suggest that M. morganii undergoes evolution driven by the influence of MGEs, thereby significantly enhancing its adaptability to selective pressures of environmental changes and clinical antimicrobial agents.IMPORTANCEThe growing clinical significance of Morganella morganii arises from its abundant virulence factors and antimicrobial resistance genes, resulting in elevated infection rates and increased clinical scrutiny. However, research on the molecular epidemiology and evolutionary trends of M. morganii has been scarce. Our study established a list of virulence-related genes (VRGs) for M. morganii and conducted a large-scale epidemiological investigation into these VRGs. Based on genomic classification, three novel genotypes of M. morganii were identified, representing evolutionary adaptations and responses to environmental challenges. Furthermore, we discovered the emergence of a sequence cluster enriched with antimicrobial resistance genes, VRGs, and mobile genetic elements, attributed to the selective pressure of antimicrobial agents. In addition, we identified a novel conjugative plasmid harboring the blaKPC-2 gene. These findings hold significance in monitoring and comprehending the epidemiology of M. morganii.

Complete genome sequence of an extensively drug resistant (XDR) M. morganii SMM01 isolated from a patient with urinary and fecal incontinence.

OBJECTIVE: M. morganii is a gram-negative, non-lactose fermenting and an opportunistic pathogen frequently associated with nosocomial infections. Although first isolated in 1906 from a pediatric fecal sample, not many M. morganii isolates have been sequenced. The objective of this work is to determine the complete genome sequence of an XDR M. morganii strain (SMM01) isolated from the urine of a patient with urinary and fecal incontinence and to characterize its antimicrobial resistance profile. DATA DESCRIPTION: Here, we report the complete genome sequence of M. morganii SMM01 generated from the hybrid assembly of Illumina HiSeq X and Nanopore MinION reads. The assembly is 100% complete with genome size of 39,30,130 bp and GC content of 51%. Genomic features include 3617 CDS, 18 rRNAs, 78 tRNAs, 4 ncRNAs and 60 pseudogenes. Antimicrobial resistance profile was characterized by the presence of genes conferring resistance to aminoglycosides, ß-lactams, fluoroquinolones, chloramphenicol, and tetracyclines. Secondary metabolite biosynthetic gene clusters like NRPS, T1PKS, thiopeptide, beta-lactone, and bacteriocin were identified. The genome data described here would be the first complete genome of an Indian M. morganii isolate providing crucial information on antimicrobial resistance patterns, paving the way for further comparative genome analyses.

Glycan-dependent cell adhesion mechanism of Tc toxins.

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.

Whole genome sequencing provides genomic insights into three Morganella morganii strains isolated from bovine rectal swabs in Dhaka, Bangladesh.

Morganella morganii, a gram negative, facultative anaerobic bacterium belonging to the Proteeae tribe of the Morganellaceae family, is an unusual opportunistic pathogen mainly responsible for nosocomial and urinary tract infections. While cattle have long been established as a source of a few zoonotic pathogens, no such data has been recorded for M. morganii despite its ubiquitous presence in nature and a number of animal hosts. In this study, draft genomes were produced of three M. morganii isolates from Bangladeshi cattle. The three isolates, named B2, B3 and B5, possessed an average genome size of 3.9 Mp, a GC% of ∼51% and pan and core genomes of 4637 and 3812 genes, respectively. All strains were bearers of the qnrD1 carrying plasmid Col3M and possessed roughly similar virulence profiles and prophage regions. The strains also carried genes that were unique when compared with other publicly available M. morganii genomes. Many of these genes belonged to metabolic pathways associated with adaptation to environmental stresses and were predicted in silico to be borne in genomic islands. The findings of this study expand on the current understanding of M. morganii''s genomic nature and its adaptation in cattle.

Ringing bells: Morganella morganii fights for recognition.

OBJECTIVES: The global increase in rare opportunistic microbial infections is alarming. The current review was undertaken to study the diversified disease spectrum, pathogenicity, and resistance patterns of Morganella morganii. STUDY DESIGN: This study is a review of the diversified disease spectrum of M. morganii. METHODS: The articles used in this review were all extracted from PubMed and Google Scholar, using the terms 'M. morganii', 'prevalence', 'virulence factors', 'infections', 'resistance pattern', and 'genomics'. This review includes original articles, reviews, and case reports focusing on M. morganii, hospital-based prevalence studies, and studies on resistance in M. morganii published between 1906 and April 2019. Articles published in English, French, Spanish, and Chinese were reviewed. RESULTS: M. morganii has had a significant impact as a clinical pathogen and the pace of its occurrence and the increase in its resistance rates puts this bacterium on the path to becoming the next 'superbug'. These developments not only impact M. morganii, but as a result of gene and plasmid transfer evolution, other clinical pathogens have been able to acquire their diverse intrinsic and acquired virulence genes. Its vast host range raises concerns around its capacity to generate new infections through novel symbiotic relationships. CONCLUSIONS: M. morganii opportunism is being increasingly reported across the globe. This bacterium is accumulating intrinsic and acquired multidrug resistance genes, resulting in increased morbidity and mortality rates for M. morganii infections and complicating its treatment. M. morganii should be recognized as a clinically significant pathogen, and clinicians should place this microorganism in the list of causative possibilities during patient care. It is important for both the infection control activities in hospitals and in public health sector.

Draft genome sequencing and annotation of a low-virulence Morganella morganii strain CQ-M7, a multidrug-resistant isolate from the giant salamander in China.

OBJECTIVES: A multidrug-resistant Morganella morganii strain (CQ-M7), isolated from the kidney of a diseased Chinese giant salamander in China, was examined with whole genome sequencing to better understand drug tolerance and its pathogenicity. METHODS: The draft genome of the investigated strain was assembled using HGA assembler and annotated using Rapid Annotations Subsystems Technology (RAST) server. The contigs were annotated by the appropriate bioinformatics tools available on the National Center for Biotechnology Information (NCBI) website. Antibiotic resistance genes were detected by PCR. Pathogenicity of the isolate was performed on 30 healthy Chinese giant salamanders with different infection dosages. RESULTS: The CQ-M7 strain showed resistance to multiple antimicrobials, especially to aminoglycoside and ß-lactam antibiotics. Seventeen drug-resistance genes were detected, which were related to ß-lactams, aminoglycosides, fluoroquinolones, tetracyclines, peptide antibiotic, and fosfomycin resistance. Sequence analysis showed the assembled genome size to be 4 966 326bp with 51.16% of GC content, containing 4587 protein-coding genes, 71 pseudogenes, five rRNAs, 80 tRNAs, and five noncoding RNAs. The genome sequence was deposited in GenBank under accession number RQIJ00000000. Artificial infection results indicated that the CQ-M7 strain was a low-virulence strain for the Chinese giant salamander. CONCLUSION: It is believed that this is the first draft genome of Chinese giant salamander original Morganella morganii strain harbouring multiple antibiotic resistance genes in China. The reported genome sequence could provide insights into antibiotic resistance mechanisms and control strategies of Morganella morganii.

Considerations for Systemic and Topical Treatment of Morganella morganii Septicemia Arising from Maggot Infestation.

INTRODUCTION: Live maggot infestation (myiasis) of wounds can present a host of ailments. Loosely associated with maggot excreta, Morganella morganii is a widespread, gram-negative rod bacterium commonly found in the intestinal tracts of humans. M morganii has been observed as being pathogenic, particularly in nosocomial and postoperative environments, as well as in immunosuppressed and elderly populations. CASE REPORT: Herein, the authors present a rare, previously unreported case of M morganii septicemia (as confirmed by positive blood culture), secondary to myiasis of the lower extremities. The patient was successfully treated with both systemic and topical interventions. Posttreatment examination revealed resolution of myiasis and negative blood cultures. CONCLUSIONS: Myiasis can be invasive, leading to severe systemic infection. In these cases, a broad-spectrum antibiotic combined with systemic and topical antiparasitic therapy should be considered.

Genome analysis of NDM-1 producing Morganella morganii clinical isolate.

OBJECTIVE: To analyze the resistome and virulence genes of Morganella morganii F675, a multidrug-resistant clinical isolate using whole genome sequencing (WGS). METHODS: M. morganii F675 was isolated from a patient from Jerusalem, Israel. WGS was performed using both 454 and SOLiD sequencing technologies. Analyses of the bacterial resistome and other virulence genes were performed in addition to comparison with other available M. morganii genomes. RESULTS: The assembled sequence had a genome size of 4,127,528 bp with G+C content of 51%. The resistome consisted of 13 antibiotic resistance genes including blaNDM-1 located in a plasmid likely acquired from Acinetobacter spp. Moreover, we characterized for the first time the whole lipid A biosynthesis pathway in this species along with the O-antigen gene cluster, the urease gene cluster and several other virulence genes. CONCLUSION: The WGS analysis of this pathogen further provides insight into its pathogenicity and resistance to antibiotics.

PCR detection and identification of histamine-forming bacteria in filleted tuna fish samples.

UNLABELLED: Total of 14 filleted yellowfin tuna fish (Thunnus albacares) sold in wholesale fish market and supermarkets in Milan, Italy, were purchased and tested to determine microbial count, histamine level, histamine-forming bacteria, and their ability to produce histamine in culture broth. Although histamine level was less than 10 ppm, many samples showed high total viable bacterial and enterobacterial counts that reached dangerous levels after temperature abuse for short periods of time. A PCR assay targeting a 709-bp fragment of the histidine decarboxylase gene (hdc) revealed that 30.5% of the 141 enteric bacteria isolated from samples were positive and potentially able to produce histamine. The hdc positive strains were mainly isolated from fish bought at wholesale fish market, where we observed several possible risk factors, such as handling in poor and non-refrigerated conditions during fillet preparation. These positive strains were identified as Citrobacter koseri/Enterobacter spp. and Morganella morganii, by 16S/23S rRNA internal transcribed spacer amplification and 16S rRNA sequence analysis. The strains showed a variable ability of histamine production, with Morganella morganii being the most active histamine-producing species. A direct DNA extraction from fish and a PCR targeting the hdc gene showed a high degree of concordance with the results obtained through microbiological and chemical analyses, and could aid in the prompt detection of potentially contaminated fish products, before histamine accumulates. PRACTICAL APPLICATION: The use of methods for the early and rapid detection of bacteria producing biogenic amines is important for preventing accumulation of these toxic substances in food products. In this study, we used a molecular approach for the detection of histamine-forming bacteria in fish. PCR-based methods require expensive equipment and a high degree of training for the user, but are fast (< 24 h) and reliable. They now represent the best predictive methods to identify a potential risk factor in fish products during processing, storage, and marketing and can be used in the investigation of risk reduction strategies.

Whole-genome sequencing and identification of Morganella morganii KT pathogenicity-related genes.

BACKGROUND: The opportunistic enterobacterium, Morganella morganii, which can cause bacteraemia, is the ninth most prevalent cause of clinical infections in patients at Changhua Christian Hospital, Taiwan. The KT strain of M. morganii was isolated during postoperative care of a cancer patient with a gallbladder stone who developed sepsis caused by bacteraemia. M. morganii is sometimes encountered in nosocomial settings and has been causally linked to catheter-associated bacteriuria, complex infections of the urinary and/or hepatobiliary tracts, wound infection, and septicaemia. M. morganii infection is associated with a high mortality rate, although most patients respond well to appropriate antibiotic therapy. To obtain insights into the genome biology of M. morganii and the mechanisms underlying its pathogenicity, we used Illumina technology to sequence the genome of the KT strain and compared its sequence with the genome sequences of related bacteria. RESULTS: The 3,826,919-bp sequence contained in 58 contigs has a GC content of 51.15% and includes 3,565 protein-coding sequences, 72 tRNA genes, and 10 rRNA genes. The pathogenicity-related genes encode determinants of drug resistance, fimbrial adhesins, an IgA protease, haemolysins, ureases, and insecticidal and apoptotic toxins as well as proteins found in flagellae, the iron acquisition system, a type-3 secretion system (T3SS), and several two-component systems. Comparison with 14 genome sequences from other members of Enterobacteriaceae revealed different degrees of similarity to several systems found in M. morganii. The most striking similarities were found in the IS4 family of transposases, insecticidal toxins, T3SS components, and proteins required for ethanolamine use (eut operon) and cobalamin (vitamin B12) biosynthesis. The eut operon and the gene cluster for cobalamin biosynthesis are not present in the other Proteeae genomes analysed. Moreover, organisation of the 19 genes of the eut operon differs from that found in the other non-Proteeae enterobacterial genomes. CONCLUSIONS: This is the first genome sequence of M. morganii, which is a clinically relevant pathogen. Comparative genome analysis revealed several pathogenicity-related genes and novel genes not found in the genomes of other members of Proteeae. Thus, the genome sequence of M. morganii provides important information concerning virulence and determinants of fitness in this pathogen.

First reported fatal Morganella morganii infections in chickens.

Morganella morganii, a Gram-negative rod commonly found in the intestines of humans and other animals, is here confirmed to cause a fatal infection in chickens by isolation and identification of the bacteria, 16S rRNA gene sequencing, and experimental infection. This is the first case of M. morganii infection in chickens.

Identification of a modular pathogenicity island that is widespread among urease-producing uropathogens and shares features with a diverse group of mobile elements.

Pathogenicity islands (PAIs) are a specific group of genomic islands that contribute to genomic variability and virulence of bacterial pathogens. Using a strain-specific comparative genomic hybridization array, we report the identification of a 94-kb PAI, designated ICEPm1, that is common to Proteus mirabilis, Providencia stuartii, and Morganella morganii. These organisms are highly prevalent etiologic agents of catheter-associated urinary tract infections (caUTI), the most common hospital acquired infection. ICEPm1 carries virulence factors that are important for colonization of the urinary tract, including a known toxin (Proteus toxic agglutinin) and the high pathogenicity island of Yersinia spp. In addition, this PAI shares homology and gene organization similar to the PAIs of other bacterial pathogens, several of which have been classified as mobile integrative and conjugative elements (ICEs). Isolates from this study were cultured from patients with caUTI and show identical sequence similarity at three loci within ICEPm1, suggesting its transfer between bacterial genera. Screening for the presence of ICEPm1 among P. mirabilis colonizing isolates showed that ICEPm1 is more prevalent in urine isolates compared to P. mirabilis strains isolated from other body sites (P<0.0001), further suggesting that it contributes to niche specificity and is positively selected for in the urinary tract.

[Ability of opportunistic enterobacteria to adapt to different temperatures].

AIM: To study variability of enzymatic apparatus of opportunistic enterobacteria. MATERIALS AND METHODS: Clinical strains of Morganella morganii, Citrobacter freundii, Proteus mirabilis isolated from patients treated in Irkutsk Regional Hospital for Infectious Diseases. Activity of cellulase and lipase as well as amount of auxins and gibberellins was studied in these bacteria at different cultivation temperatures. RESULTS: It was shown that studied species isolated from humans enterobacteria are able to produce plant growth regulators amount of which depends from cultivation temperature and type of microorganism. Activity of cellulase sharply rises if temperature falls. CONCLUSION: Obtained results show high adaptation potential of opportunistic bacteria from Enterobacteriaceae family. Switch on saprophytic mechanism after fall of temperature to environment-corresponding values allows them to survive in soil and arrange different interactions with soil biota including plants.

Morganella morganii infections in a general tertiary hospital.

BACKGROUND: Morganella morganii is a commensal Gram-negative bacillus of the intestinal tract of humans and other mammals and reptiles. Few reports exist in the literature regarding infections caused by this organism. METHODS: A retrospective study at the 650-bed University Hospital of Heraklion, Crete, Greece was performed during a 4-year period (2001-2004) to identify and analyze infections caused by M. morganii. RESULTS: Twenty-four patients had M. morganii isolated from clinical specimens during the study period. Thirteen patients (54%) suffered from skin and soft tissue infections, five from pyelonephritis, three from female genital tract infections, one from pneumonia, one from gangrenous appendicitis, and one from tonsillitis. M. morganii was a constituent of polymicrobial infections in 14 patients (58%). The patients received various antibiotics, i.e., six patients received ciprofloxacin, four piperacillin/tazobactam, two amoxicillin/clavulanic acid, one ticarcillin/clavulanic acid, one ceftriaxone, one imipenem, and one cefuroxime monotherapy, whereas the remaining eight received antibiotic combinations. Two (both debilitated) of 24 patients (8%) died, despite antibiotic treatment. CONCLUSION: Skin and soft tissue infection was the commonest type of infection due to M. morganii in our series. M. morganii is commonly a part of polymicrobial infections and can rarely cause fatalities in debilitated patients.

Central nervous system infection caused by Morganella morganii.

Central nervous system (CNS) infection with Morganella morganii is very rare. We describe a 38-year-old female patient with frontal brain abscess caused by M morganii who was unsuccessfully treated. We also review all reported cases of Morganella CNS infections with an emphasis on treatment modalities and outcomes. Aggressive surgical management and appropriate antimicrobial therapy can lead to cure, but the mortality rate for these infections remains high.

[Morganella morganii and early-onset neonatal infection]. / Morganella morganii et infection maternofoetale.

UNLABELLED: Morganella morganii is an opportunistic gram-negative bacterium, resistant to ampicillin, and scarcely involved in early-onset neonatal sepsis. CASE REPORT: After a premature rupture of the membranes, a pregnant patient received prophylactic amoxicillin per os. She developed chorioamnionitis. Her infant was diagnosed with early-onset sepsis. Maternal and baby's blood cultures grew M. morganii. Both the mother and the infant were successfully treated with a third-generation cephalosporin and an aminoglycoside. DISCUSSION: The influence of a prior antibiotherapy on the emergence of M. morganii vertical infections is discussed.