Mycoplasma - Morphology, Characteristics, Biochemical reaction

Classification of Mycoplasma

The classification of Mycoplasma is achieved as follows:

Domain: Bacteria

Phylum: Mycoplasmatota

Class: Mollicutes

Order: Mycoplasmatales

Family: Mycoplasmataceae

Genus: Mycoplasma

Morphology of Mycoplasma

Unlike other bacteria, Mycoplasma spp. these prokaryotes lack a cell wall and have a unique cell membrane that contains sterols. Although they are gram-negative, they are hardly stained by the procedure. The cell membrane is three-layered and supported by the cytoskeleton of the protein network

Morphologically, Mycoplasma is small in cell size (0.3 x 0.8 μm) and have a small genome. Filtrate through a 0.45 μm filter. The bacterium is highly fastidious, and slow-growing and most are facultative anaerobes that require nucleic acid precursor molecules, fatty acids, and sterols such as cholesterol for growth.

Mycoplasma spp. is pleomorphic- occurs as a granular or filamentous formation.

• Granules may be coccoid, ballon, disc, or ring shared

• Filamentous are of varying length and show true branching

Characteristics of Mycoplasma

Mycoplasma spp. is the smallest living free-living form. The genus contains pathogens that use glucose or arginine but not urea. Mycoplasma contains over 90 species (commensals, pathogens, parasites). Some pathologically important species are:

• Mycoplasma pneumoniae – RTI, primary atypical pneumonia

• Mycoplasma hominis – PID, postpartum fever

• Mycoplasma genitalium – genital infection

• Mycoplasma fermentans – opportunistic infection in HIV patients

• Mycoplasma pirum – septicemia in HIV patients

• Mycoplasma salivarium

• Mycoplasma orale

Biochemical reaction of Mycoplasma

The biochemical reactions of different species of Mycoplasma includes:

• Mycoplasma pneumoniae, Mycoplasma fermentans, Mycoplasma genitalium, Mycoplasma agalactiae – utilize glucose and other carbohydrates as the major source of energy; also utilizes arginine

• Mycoplasma salivarium, Mycoplasma orale, Mycoplasma hominis, Mycoplasma fementans – utilize arginine as the major source of energy

• They are chemo-organotrophs and metabolism is fermentative while other species may be non-fermentative

• requires cholesterol and other sterols as growth factors

Mycoplasma genitalium

Mycoplasma genitalium causes non-gonococcal urethritis in men while in females it is associated with cervicitis and endometritis. It can also cause Pelvic Inflammatory Disease (PID) in untreated cases.

Transmission of Mycoplasma genitalium may occur from sexual contact or from mother to fetus (vertical transmission).

In fact, it is a pathogen of the genital tract but can cause occasional infection in the genitourinary and respiratory tract. The isolation of the bacteria by culture is very difficult as its Incubation period is more than 2-4 months.