The so-called L-type bacteria is that lose part or all of the cell wall because of bacterial variation, also known as cell wall defective bacteria. In 1935 Klieneberger found that the first letter L of the Luister Institute, where he was named L-type bacteria, was successfully induced in 1960 in the study of S. elegans. The physical and chemical properties of L-type bacteria, biological traits, pathogenicity and sensitivity to drugs are different from the original bacteria, and most are associated with recurrent episodes of infection, especially after antibiotic treatment.
Some people think: 20% to 30% of patients with chronic pyelonephritis is caused by L-type bacteria, it is difficult for clinical diagnosis and treatment due to the negative culture of common urine bacteria. Cocci, bacilli, Vibrio and fungi can evolve into L-type under certain conditions. It is reported that urinary tract infection caused by type L- bacteria of urinary tract infection with gram positive cocci accounted for 75%, Gram-negative bacteria accounted for about 20% , among them, especially in Staphylococcus aureus is the most common, there are significant differences caused by this type of bacteria and pathogen distribution of urinary tract infection.
In clinical treatment, often this phenomenon, acute urinary tract infection in the treatment with antibiotics, often to chronic or recurrent, the mechanism may be related to some of the bacteria into the L-type. Such as the improper use of antibiotics, not only can not kill bacteria, but induced the formation of L-type bacteria, leading to the emergence of drug-resistant bacteria, which is one of the reasons for the persistent infection of urinary tract.
In addition, the body of antibodies, complement, lysozyme, renal medulla hypertonic, urine in the high concentration of urea, low pH can induce bacteria to L-type. L-type bacteria in the hypotonic or isotonic medium is not easy to grow, but in the renal medulla hypertonic environment to survive and return to the ancestors, causing urinary tract infection recurrence, so urine L-type bacterial culture is particularly important.