Mycoplasma is an atypical bacterial genus which main characteristic is that naturally lacks cells walls and are the smallest and simplest self-replicating bacteria. The presence of sterols in the plasma membrane helps in regulation of membrane fluidity and protects from osmotic lysis so they don’t need a wall. Some mycoplasma species are pathogenic in humans and animals, being Mycoplasma pneumoniae the major human pathogen.
Mycoplasma infection in humans
The most common disease caused by mycoplasma infection, especially in children, is respiratory infections, causing upper respiratory illness. After contact with Mycoplasma pneumoniae, the bacterium can attach itself to the lung tissue and multiply until a full infection develops.
Symptoms often include sore throat, fever, cough and, in more severe cases, pneumonia, a more serious lung infection, which may require hospital care.
Mycoplasma pneumoniae spread from person to person by small respiratory droplets in the air that are generated by people carrying the bacteria in their nose or throat when coughing or sneezing.
Other mycoplasma pathogenic species are pathogens of the genitourinary tract, including Mycoplasma genitalium,Mycoplasma parvum and Mycoplasma hominis.
Mycoplasma in the laboratory
Mycoplasma are everywhere! It is estimated that around 35% of the cell cultures currently used in research around the world may be infected with mycoplasma. This is due to the fact that given their lack of a cell wall, mycoplasma are resistant to penicillin and streptomycin, the main antibiotics used in laboratories.
In addition, detecting contamination with mycoplasma is not straightforward, as it cannot be visualised under the microscopy due to lack of the turbidity typically associated with bacterial or fungal contamination.
Consequences of mycoplasma contamination are very important, as mycoplasma compete with host cells for nutrients and also trigger different mechanisms against pathogens, including interferon expression and activation of the NF-kB pathway.
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