Morgan’s Aspergillus is rare and the diagnosis and treatment are specific Morgan’s bacteria, a genus of Morgan’s bacteria in the family Enterobacteriaceae. Discovered by Morgan in 1906. In the past, it was called Morgan’s Aspergillus. In nature, it is widely distributed and often exists in the intestines of humans and animals. In recent years, with the development of biology, through the study of its DNA, it was found that the content of guanine and cytosine in the DNA molecule of Morgan’s Aspergillus is significantly higher than other Aspergillus. Therefore, it is now separated into a separate genus called Morganella. The following have been found: Morganella and Morganella biota. Morganella is a non-disperse growth of unicellular organisms. Gram-staining negative rod with blunt rounded ends. There are often variegated bodies, sometimes globular, sometimes long and curved or long filamentous bodies (10-30 μm). No pods and budding spores, powered, with circumferential flagella and mycorrhizal hairs. Its hemagglutination and adsorption is not inhibited by mannose. Morganella – culture and biochemical reactions Morganella is non-aerobic or partly anaerobic bacteria. The optimum growth temperature is 34-37℃, it can also develop between 10-45℃, and can be killed in 55℃ water for 1h. Culture requirements are not high. Good growth in ordinary medium, can grow in potassium cyanide (potassium cyanide) medium. Growth in broth medium is uniformly mixed and thick, with a film on the surface. Colonies on SS plates are round, flat and thin, translucent, easily confused with other intestinal pathogenic bacteria, Morganella cultures have a special odor, can hemolysis. Can produce indole. Positive for methyl red reaction, negative for VP reaction. Can rapidly hydrolyze urea, does not form hydrogen sulfide, does not liquefy gelatin. No lysine decarboxylase and arginine double hydrolase, can produce ornithine decarboxylase and phenylalanine deaminase. Does not ferment lactose, sucrose, mannitol, guaiac, salicin, lateral marigold alcohol, inositol, sorbitol, arabinose, cottonseed sugar and rhamnose, 80% of its strains produce gas when fermenting glucose. Morganella – antigens and typing Morganella has 34 “O” groups and 25 “H” antigens. There are 66 serotypes that can be classified by the antigenic group of the bacterium and then by the flagellar antigen. Morganella – Pathogenesis Morganella is a conditional pathogenic bacterium. It is not pathogenic in the human intestine, but can cause pneumonia when it leaves the intestine and enters the lungs. Its pathogenesis is related to its endotoxin and bacterial virulence. Animal experiments have shown that mice can be killed by intraperitoneal injection of 0.5 to 1.0 ml of a virulent strain of the bacterium. It is thought that the polysaccharide component may be the main relevant component of its virulence. In addition, Morganella can also secrete hemolysin and the bacterium has many cilia, and these may also have an important role in the respiratory tract. Morganella pneumonia is mostly a hospital-acquired infection and is most often seen in the elderly. Any condition that can lead to impaired immune function in the body may be a trigger for infection. The most common causes are serious underlying diseases such as cancer and diabetes mellitus; long-term application of corticosteroids, immunosuppressants, and chemotherapy and radiotherapy in tumor patients; certain invasive examinations and treatments such as catheterization, venipuncture, joint puncture, major surgery, and especially respiratory measures such as tracheal intubation, tracheotomy, mechanical ventilation, and nebulized inhalation. In addition, the long-term application of broad-spectrum antibiotics can lead to dysbiosis of the normal flora, which is conducive to the colonization of the upper respiratory tract by Morganella, and when the body’s resistance is reduced, it can enter the lower respiratory tract and cause disease, resulting in primary or secondary Morganella pneumonia. The pathological changes of Morganella pneumonia are lobar or segmental distribution of the lung, with destruction of alveolar tissue to form small abscesses. It may also present as bronchopneumonia.