Methylobacterium mesophilicum

Methylobacterium mesophilicum is a Gram-negative rod bacterium that forms pink-pigmented colonies and belongs to the genus Methylobacterium. The pathogen is a biofilm former.

Methylobacterium mesophilicum causes - in predominantly immunocompromised patients - nosocomial infections. Mostly, mild clinical symptoms occur, such as fever. Cases with severe infections, including sepsis, peritonitis (inflammation of the peritoneum), and pneumonia, have also been reported.

Methylobacterium mesophilicum is found in the environment. The pathogen has been isolated from leaf surfaces, soil and wastewater.

Relevance of pathogen in transmission in endoscopy

  • Gastroenterology: Low

  • Pulmonology: High

  • Ear, nose, and throat: High

  • Urology: Not relevant

Relevance for endoscope surveillance

  • High concern organism

Transmission route

Most infections are acquired nosocomially. Central catheters are the most common point of entry.

Biofilm fragments can contaminate the water in healthcare facilities and lead to the spread of the pathogen. To prevent a recontamination of previously reprocessed endoscopes, the microbiological quality of the water used for final rinsing is of high importance.

Resistance to antibiotics

Methylobacterium mesophilicum frequently shows resistance to β-lactam antibiotics.

Sources and further readings

  1. Kovaleva J et al. Methylobacterium and Its Role in Health Care-Associated Infection, ASM Journals/ Journal of Clinical Microbiology / Vol. 52, No. 5., May 2014.

  2. Sanders JW et al. Methylobacterium mesophilicum Infection: Case Report and Literature Review of an Unusual Opportunistic Pathogen, Clinical Infectious Diseases Vol. 30, No. 6 (Jun., 2000), pp. 936–938.