Nutrition Spain , León, Wednesday, April 15 of 2015, 16:26

Cases of infection by Janibacter terrae in humans are published for the first time

The study published in the ‘Infection’ journal shows that this bacteria is not only present in the environment, as up to now it had been exclusively isolated from the soil

Cristina G. Pedraz/DICYT Researchers from the departments of Clinical Microbiology and Internal Medicine of the University Welfare Complex of León, the Institute of Biomedicine of the University of León (IBIOMED), the National Microbiology Centre of the Carlos III Health Institute, and the University School of Physiotherapy of the Spanish Organisation for the Blind (Organización Nacional de Ciegos Españoles, ONCE) of Madrid have published for the first time four cases of bacteremia (the presence of bacteria in the blood) owing to Janibacter terrae in humans.

The study published in the Infection journal shows that Janibacter terrae is not only present in the environment, as up to now it had been exclusively isolated from the soil.

The main author of the article, the researcher of the Department of Clinical Microbiology of the León Welfare Complex and of the IBIOMED Dr Isabel Fernández Natal, explains that up to now only two cases had been reported of the isolation of microorganisms belonging to the genus Janibacter from human samples. The first case was a bacteremia owing to an undescribed species of Janibacter in a patient diagnosed as suffering from myeloid leukaemia, and the second was a bacteremia caused by J. melonis in a patient with low-grade fever and without a base disease.

In this study the researchers provide exhaustive microbiological and clinical data on four fevered patients studied over a three-year period, during which J. terrae was isolated from blood cultures (bacteremia). The patients studied showed base pathologies such as chronic obstructive pulmonary disease with acute bronchitis, diabetes, non Hodgkin's lymphoma, and gastric cancer with hepatic metastasis. On the other hand, "it is the first time that antibiotic awareness data have been provided in this field”.

The isolations were obtained as from two consecutive blood samples from each patient. Phenotypic identification methods were used (commercial methods and conventional complementary tests) and genotypic ones (the amplification and sequencing of ADN fragments). All patients were treated with antibiotics; two of them evolved favourably and were subsequently cured while two others died, the latter having had a serious base pathology.

“This is the first publication of four cases of bacteremia owing to Janibacter terrae in humans, showing that it is not only present in the environment. Moreover, J. terrae can be considered to be an opportunist pathogen responsible for bacteremia in patients with a serious base pathology”, Fernández Natal indicates.

Characteristics of the bacteria

The species of the genus Janibacter are aerobic microorganisms, i.e. they need oxygen to live. Their colonies are humid, circular, and convex and range from white to yellow in colour. Optimum growth occurs between 23 and 35 degrees Centigrade.

The genus was described in 1997 from sewage and during its culture has a characteristic two-faced morphology such as the god Janus of Roman mythology (hence its name). This morphology is not however exclusive to this genus as it can also be seen in members of the genera Artrhrobacter and Brevibacterium.
Nine species have so far been described: J. limosus, J. terrae, J. indicus, J. melonis, J. anophelis, J. hoylei, J. corallicola, J. alkaliphilus, and J. cremeus. J. limosus and J. terrae have been isolated from soils contaminated with sewage and J. indicus from hydrothermal sediments of the Indian Ocean. J. corallicola and J. alkaliphilicus have been isolated on coral, and J. melonis, J. anophelis and J. hoylei on plants, insects, and air respectively.

This study has been financed by the Regional Health Management of the Regional Government of Castilla y León by means of Research Project GRS 698/A/2011.




Bibliographical reference:
Fernández-Natal, M. I., Sáez-Nieto, J. A., Medina-Pascual, M. J., Valdezate-Ramos, S., Guerra-Laso, J. M., Rodríguez-Pollán, R. H., y Soriano, F. (2015). “First report of bacteremia by Janibacter terrae in humans”. Infection, 43, 1, 103-106. DOI 10.1007/s15010-014-0672-7