Morganella morganii

Updated : November 29, 2023

Mail Whatsapp PDF Image

The absence of a comprehensive global surveillance system has rendered the precise tally of Morganella morganii infections elusive. Nonetheless, certain studies have endeavored to unveil the incidence and prevalence of these infections across diverse regions and contexts. For instance, a study conducted in a Taiwanese hospital from 2002 to 2011 illuminated that M. morganii contributed to 0.6% of urinary tract infections.

Similarly, within the Indian healthcare landscape, another study spanning 2009 to 2013 identified Morganella morganii in 1.4% of blood cultures from a hospital, shedding light on its notable presence. In different geographic realms, the prevalence of Morganella morganii emerges with intriguing variations.

Notably, studies unveiled that the occurrence of this bacterium in urine samples from individuals grappling with urinary tract infections manifested as 0.8% in Turkey, 1.2% in Iran, and 2.4% in Saudi Arabia. Further insights from the Egyptian terrain indicated a prevalence of 3.7% in wound samples from patients afflicted with diabetic foot ulcers, accentuating the bacterium’s clinical implications.  

Seasonal nuances and geographical landscapes intricately interweave with Morganella morganii‘s prevalence. A study from Taiwan pinpointed a noteworthy surge in infections during the summer months, attributed to elevated temperatures and humidity levels. Contrastingly, an Indian investigation highlighted higher infection rates in rural enclaves than urban centers, potentially underscored by variances in hygiene standards and sanitation facilities. 

 

Kingdom: Bacteria 

Phylum: Proteobacteria 

Class: Gammaproteobacteria 

Order: Enterobacterales 

Family: Morganellaceae 

Genus: Morganella 

Species: Morganella morganii 

M. morganii is a gram-negative bacterium that appears as a straight rod with a typical diameter ranging from 0.6-0.7 μm. Its length measures 1.0-1.7 μm, contributing to its elongated morphology.

M. morganii is equipped with peritrichous flagella. These hair-like appendages emerge from various points along the cell surface, providing the bacterium with a flagellum covering.

 

Morganella morganii exhibits diverse antigenic types, numbering at least 17, designated as O1 to O17. These antigenic distinctions are discerned through molecular serotyping, a technique that harnesses specific genes within the O-antigen gene cluster (O-AGC). This genetic repertoire orchestrates synthesizing and modifying the O-antigen, a vital bacterial surface component.

The O-AGC region, nestled within the bacterial genome, houses the genetic instructions pivotal for the assembly and modulation of the O-antigen’s structural nuances. everal drug-resistant genes have been documented, like dha-1, dha-5, and pse-1 genes are resistant to b-lactams. catA1, catA2, catB3 resistant to Chloramphenicol. ereA2 resistant to Macrolides. Morganella morganii produce toxins like tccB3, hmpBA, tccA, xptC1, tcdB2, tccB, xptA1, tcdA4, and tcaC.  

Strains of M. morganii subsp. morganii: Notable strains with diverse characteristics originate from the M. morganii subspecies spectrum. M11, isolated from a patient suffering from summer diarrhea in 1906, is historically significant as a pioneering reference for the species. This strain is now used as a quality control standard for Sensititre products.

In a different scenario, the strain 2018-01-01 appears in a modern environment isolated from a patient’s urinary sample in China. The discovery of this strain highlights a worrying profile of resistance, displaying increased susceptibility to antibiotics such as cephalosporin, penicillin, quinolone, & tetracycline. Along with its resistance, strain 2018-01-01 carries several virulence factors, including hemolysin, urease, flagella, & biofilm formation genes, highlighting its clinical significance. 

M. morganii subsp. sibonii Strain:

A distinct entity within the M. morganii subspecies is strain 17-1 of M. morganii subsp. sibonii, harvested from cheese in Switzerland in 2017. This strain’s intriguing characterization extends beyond conventional boundaries, as it can generate biogenic amines, cadaverine, and putrescine, compounds with toxic implications upon excessive consumption. Notably, the strain harbors a novel gene cluster orchestrating the synthesis of lysine decarboxylase and a cadaverine-lysine antiporter, pivotal components in the intricate process of cadaverine formation from lysine.

Central to M. morganii‘s pathogenicity is its adeptness in adhesion and motility. Utilizing type IV pili, the bacterium adheres to host cells and creates biofilms, which offer protection and facilitate colonization. Its twitching motility, powered by these pili’s dynamic extension and retraction, aids in its movement toward host cells and evasion from immune detection. 

M. morganii produces urease, which plays a vital role in its pathogenesis. Urease is a protein enzyme that catalyzes the conversion of urea, a consequence of protein metabolism, into ammonia & carbon dioxide. This enzyme activity raises the pH of its surroundings, causing it to become more alkaline. In the setting of the urinary tract, this alkalinity can cause kidney stones to form & harm urinary tract tissues. Furthermore, urease-mediated pH increase promotes M. morganii survival and colonization within the urinary system, creating a suitable habitat for growth.

M. morganii‘s synthesis of hemolysin adds another layer to its pathogenic arsenal. Hemolysin is a highly toxic toxin that can rupture red blood cells and release hemoglobin into the surrounding environment. It can result in hemolytic anemia, defined by decreased functional red blood cells. Also, hemolysin’s cytotoxic characteristics break cell membranes and stimulate inflammatory responses, adding to tissue damage & immunological activation.

Notably, hemolysin has been found to play a role in various clinical settings, including postsurgical wound infections & urinary tract infections. M. morganii‘s ability to form biofilms is implicated in its capacity to establish persistent infections, particularly in medical devices like urinary catheters. Biofilms offer a protective environment that shields bacteria from immune responses and antimicrobial treatments.

 

The innate immune system comprises an array of specialized cells and molecules adept at recognizing and eliminating Morganella morganii. Essential components include phagocytes like neutrophils and macrophages, which engulf and destroy pathogens, while natural killer cells neutralize infected host cells.

The complement system, a cascade of proteins, contributes to pathogen elimination via opsonization and direct lysis. Additionally, inflammatory mediators orchestrate immune responses and create an inhospitable environment for Morganella growth. 

The adaptive immune system, an intricate defense, endows the host with specificity and memory against Morganella morganii. Lymphocytes, namely B and T cells, can recognize and target specific antigens associated with the pathogen. This response is bolstered by antibodies and cytokines that neutralize toxins, mark pathogens for destruction, and amplify immune activity. 

Toxin Neutralization: The immune system neutralizes harmful toxins like urease and hemolysin secreted by M. morganii. Antibodies and enzymes may bind or inactivate these toxins, mitigating their destructive impact. 

Opsonization and Phagocytosis: Antibodies and complement components collaborate to opsonize M. morganii, facilitating its recognition and engulfment by phagocytes, subsequently promoting clearance. 

 

Morganella morganii, although relatively uncommon, has been identified as a causative agent of a range of clinical manifestations in humans. Among these manifestations are urinary tract infections, nosocomial surgical wound infections, peritonitis, central nervous system infections, endophthalmitis, pneumonia, necrotizing fasciitis, neonatal sepsis, chorioamnionitis, pyomyositis, and arthritis.

Notably, nosocomial infections have been frequently associated with M. morganii, often occurring as postsurgical wound infections or urinary tract infections in healthcare settings. The patients most susceptible to developing severe infections, including bacteremia, are immunocompromised, elderly, diabetic, or possess underlying severe medical conditions.

While M. morganii has traditionally been considered an opportunistic pathogen with a relatively low level of inherent virulence, certain strains have been found to harbor “antibiotic-resistant plasmids.” These strains have been implicated in nosocomial outbreaks, raising concerns about their potential to cause severe infections in healthcare settings. 

 

Culture method: The definitive diagnostic method for Morganella morganii infections involves isolating and identifying the bacteria from the site of infection or blood. This process, known as culture, entails cultivating the pathogen on specific growth media like MacConkey or sheep blood agar.

Morganella morganii typically forms flat, colorless colonies on these media. Identification is achieved by recovering small, oxidase-negative, catalase, and indole-positive gram-negative rods from blood agar or MacConkey agar plates. 

Metabolic Characteristics:Morganella morganii exhibits distinct metabolic characteristics. It ferments glucose and mannose, while lactose fermentation is absent. The bacterium is motile, facultatively anaerobic, and lacks a capsule. It possesses the enzyme urease, facilitating urea hydrolysis, and can reduce nitrates. 

 

  • Rigorous adherence to infection control practices, including proper hand hygiene, sterilization of medical instruments, and maintaining a clean healthcare environment, is crucial to prevent the transmission of Morganella morganii. 
  • Using aseptic procedures during catheter insertion and proper maintenance can minimize the incidence of Morganella morganii infections in urinary tract infections caused by catheter use. 

 

Content loading

Latest Posts

Morganella morganii

Updated : November 29, 2023

Mail Whatsapp PDF Image



The absence of a comprehensive global surveillance system has rendered the precise tally of Morganella morganii infections elusive. Nonetheless, certain studies have endeavored to unveil the incidence and prevalence of these infections across diverse regions and contexts. For instance, a study conducted in a Taiwanese hospital from 2002 to 2011 illuminated that M. morganii contributed to 0.6% of urinary tract infections.

Similarly, within the Indian healthcare landscape, another study spanning 2009 to 2013 identified Morganella morganii in 1.4% of blood cultures from a hospital, shedding light on its notable presence. In different geographic realms, the prevalence of Morganella morganii emerges with intriguing variations.

Notably, studies unveiled that the occurrence of this bacterium in urine samples from individuals grappling with urinary tract infections manifested as 0.8% in Turkey, 1.2% in Iran, and 2.4% in Saudi Arabia. Further insights from the Egyptian terrain indicated a prevalence of 3.7% in wound samples from patients afflicted with diabetic foot ulcers, accentuating the bacterium’s clinical implications.  

Seasonal nuances and geographical landscapes intricately interweave with Morganella morganii‘s prevalence. A study from Taiwan pinpointed a noteworthy surge in infections during the summer months, attributed to elevated temperatures and humidity levels. Contrastingly, an Indian investigation highlighted higher infection rates in rural enclaves than urban centers, potentially underscored by variances in hygiene standards and sanitation facilities. 

 

Kingdom: Bacteria 

Phylum: Proteobacteria 

Class: Gammaproteobacteria 

Order: Enterobacterales 

Family: Morganellaceae 

Genus: Morganella 

Species: Morganella morganii 

M. morganii is a gram-negative bacterium that appears as a straight rod with a typical diameter ranging from 0.6-0.7 μm. Its length measures 1.0-1.7 μm, contributing to its elongated morphology.

M. morganii is equipped with peritrichous flagella. These hair-like appendages emerge from various points along the cell surface, providing the bacterium with a flagellum covering.

 

Morganella morganii exhibits diverse antigenic types, numbering at least 17, designated as O1 to O17. These antigenic distinctions are discerned through molecular serotyping, a technique that harnesses specific genes within the O-antigen gene cluster (O-AGC). This genetic repertoire orchestrates synthesizing and modifying the O-antigen, a vital bacterial surface component.

The O-AGC region, nestled within the bacterial genome, houses the genetic instructions pivotal for the assembly and modulation of the O-antigen’s structural nuances. everal drug-resistant genes have been documented, like dha-1, dha-5, and pse-1 genes are resistant to b-lactams. catA1, catA2, catB3 resistant to Chloramphenicol. ereA2 resistant to Macrolides. Morganella morganii produce toxins like tccB3, hmpBA, tccA, xptC1, tcdB2, tccB, xptA1, tcdA4, and tcaC.  

Strains of M. morganii subsp. morganii: Notable strains with diverse characteristics originate from the M. morganii subspecies spectrum. M11, isolated from a patient suffering from summer diarrhea in 1906, is historically significant as a pioneering reference for the species. This strain is now used as a quality control standard for Sensititre products.

In a different scenario, the strain 2018-01-01 appears in a modern environment isolated from a patient’s urinary sample in China. The discovery of this strain highlights a worrying profile of resistance, displaying increased susceptibility to antibiotics such as cephalosporin, penicillin, quinolone, & tetracycline. Along with its resistance, strain 2018-01-01 carries several virulence factors, including hemolysin, urease, flagella, & biofilm formation genes, highlighting its clinical significance. 

M. morganii subsp. sibonii Strain:

A distinct entity within the M. morganii subspecies is strain 17-1 of M. morganii subsp. sibonii, harvested from cheese in Switzerland in 2017. This strain’s intriguing characterization extends beyond conventional boundaries, as it can generate biogenic amines, cadaverine, and putrescine, compounds with toxic implications upon excessive consumption. Notably, the strain harbors a novel gene cluster orchestrating the synthesis of lysine decarboxylase and a cadaverine-lysine antiporter, pivotal components in the intricate process of cadaverine formation from lysine.

Central to M. morganii‘s pathogenicity is its adeptness in adhesion and motility. Utilizing type IV pili, the bacterium adheres to host cells and creates biofilms, which offer protection and facilitate colonization. Its twitching motility, powered by these pili’s dynamic extension and retraction, aids in its movement toward host cells and evasion from immune detection. 

M. morganii produces urease, which plays a vital role in its pathogenesis. Urease is a protein enzyme that catalyzes the conversion of urea, a consequence of protein metabolism, into ammonia & carbon dioxide. This enzyme activity raises the pH of its surroundings, causing it to become more alkaline. In the setting of the urinary tract, this alkalinity can cause kidney stones to form & harm urinary tract tissues. Furthermore, urease-mediated pH increase promotes M. morganii survival and colonization within the urinary system, creating a suitable habitat for growth.

M. morganii‘s synthesis of hemolysin adds another layer to its pathogenic arsenal. Hemolysin is a highly toxic toxin that can rupture red blood cells and release hemoglobin into the surrounding environment. It can result in hemolytic anemia, defined by decreased functional red blood cells. Also, hemolysin’s cytotoxic characteristics break cell membranes and stimulate inflammatory responses, adding to tissue damage & immunological activation.

Notably, hemolysin has been found to play a role in various clinical settings, including postsurgical wound infections & urinary tract infections. M. morganii‘s ability to form biofilms is implicated in its capacity to establish persistent infections, particularly in medical devices like urinary catheters. Biofilms offer a protective environment that shields bacteria from immune responses and antimicrobial treatments.

 

The innate immune system comprises an array of specialized cells and molecules adept at recognizing and eliminating Morganella morganii. Essential components include phagocytes like neutrophils and macrophages, which engulf and destroy pathogens, while natural killer cells neutralize infected host cells.

The complement system, a cascade of proteins, contributes to pathogen elimination via opsonization and direct lysis. Additionally, inflammatory mediators orchestrate immune responses and create an inhospitable environment for Morganella growth. 

The adaptive immune system, an intricate defense, endows the host with specificity and memory against Morganella morganii. Lymphocytes, namely B and T cells, can recognize and target specific antigens associated with the pathogen. This response is bolstered by antibodies and cytokines that neutralize toxins, mark pathogens for destruction, and amplify immune activity. 

Toxin Neutralization: The immune system neutralizes harmful toxins like urease and hemolysin secreted by M. morganii. Antibodies and enzymes may bind or inactivate these toxins, mitigating their destructive impact. 

Opsonization and Phagocytosis: Antibodies and complement components collaborate to opsonize M. morganii, facilitating its recognition and engulfment by phagocytes, subsequently promoting clearance. 

 

Morganella morganii, although relatively uncommon, has been identified as a causative agent of a range of clinical manifestations in humans. Among these manifestations are urinary tract infections, nosocomial surgical wound infections, peritonitis, central nervous system infections, endophthalmitis, pneumonia, necrotizing fasciitis, neonatal sepsis, chorioamnionitis, pyomyositis, and arthritis.

Notably, nosocomial infections have been frequently associated with M. morganii, often occurring as postsurgical wound infections or urinary tract infections in healthcare settings. The patients most susceptible to developing severe infections, including bacteremia, are immunocompromised, elderly, diabetic, or possess underlying severe medical conditions.

While M. morganii has traditionally been considered an opportunistic pathogen with a relatively low level of inherent virulence, certain strains have been found to harbor “antibiotic-resistant plasmids.” These strains have been implicated in nosocomial outbreaks, raising concerns about their potential to cause severe infections in healthcare settings. 

 

Culture method: The definitive diagnostic method for Morganella morganii infections involves isolating and identifying the bacteria from the site of infection or blood. This process, known as culture, entails cultivating the pathogen on specific growth media like MacConkey or sheep blood agar.

Morganella morganii typically forms flat, colorless colonies on these media. Identification is achieved by recovering small, oxidase-negative, catalase, and indole-positive gram-negative rods from blood agar or MacConkey agar plates. 

Metabolic Characteristics:Morganella morganii exhibits distinct metabolic characteristics. It ferments glucose and mannose, while lactose fermentation is absent. The bacterium is motile, facultatively anaerobic, and lacks a capsule. It possesses the enzyme urease, facilitating urea hydrolysis, and can reduce nitrates. 

 

  • Rigorous adherence to infection control practices, including proper hand hygiene, sterilization of medical instruments, and maintaining a clean healthcare environment, is crucial to prevent the transmission of Morganella morganii. 
  • Using aseptic procedures during catheter insertion and proper maintenance can minimize the incidence of Morganella morganii infections in urinary tract infections caused by catheter use. 

 

Latest Posts


Free CME credits

Both our subscription plans include Free CME/CPD AMA PRA Category 1 credits.

Digital Certificate PDF

On course completion, you will receive a full-sized presentation quality digital certificate.

medtigo Simulation

A dynamic medical simulation platform designed to train healthcare professionals and students to effectively run code situations through an immersive hands-on experience in a live, interactive 3D environment.

medtigo Points

medtigo points is our unique point redemption system created to award users for interacting on our site. These points can be redeemed for special discounts on the medtigo marketplace as well as towards the membership cost itself.
 
  • Registration with medtigo = 10 points
  • 1 visit to medtigo’s website = 1 point
  • Interacting with medtigo posts (through comments/clinical cases etc.) = 5 points
  • Attempting a game = 1 point
  • Community Forum post/reply = 5 points

    *Redemption of points can occur only through the medtigo marketplace, courses, or simulation system. Money will not be credited to your bank account. 10 points = $1.

All Your Certificates in One Place

When you have your licenses, certificates and CMEs in one place, it's easier to track your career growth. You can easily share these with hospitals as well, using your medtigo app.

Our Certificate Courses