Do human mycoplasmas rely on iron?

A review article published in the Computational and Structural Biotechnology Journal describes the putative iron-enzymes, transporters, and metalloregulators of four relevant human mycoplasmas and questions the use of iron by these minimal organisms.

Alex Perálvarez-Marín, et al., Computational and Structural Biotechnology Journal, 2021.
Metal utilization in genome-reduced bacteria: do human mycoplasmas rely on iron??


Mycoplasmas are parasitic bacteria with streamlined genomes and complex nutritional requirements. Although iron is vital for almost all organisms, its utilization by mycoplasmas is controversial. Despite its minimalist nature, mycoplasmas can survive and persist within the host, where iron availability is rigorously restricted through nutritional immunity. In this review, we describe the putative iron-enzymes, transporters, and metalloregulators of four relevant human mycoplasmas. This work brings in light critical differences in the mycoplasma-iron interplay. Mycoplasma penetrans, the species with the largest genome (1.36 Mb), shows a more classic repertoire of iron-related proteins, including different enzymes using iron-sulfur clusters as well as iron storage and transport systems. In contrast, the iron requirement is less apparent in the three species with markedly reduced genomes, Mycoplasma genitalium (0.58 Mb), Mycoplasma hominis (0.67 Mb) and Mycoplasma pneumoniae (0.82 Mb), as they exhibit only a few proteins possibly involved in iron homeostasis. The multiple facets of iron metabolism in mycoplasmas illustrate the remarkable evolutive potential of these minimal organisms when facing nutritional immunity and question the dependence of several human-infecting species for iron. Collectively, our data contribute to better understand the unique biology and infective strategies of these successful pathogens.

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Mycoplasma agalactiae: The Sole Cause of Classical Contagious Agalactia?

A recent commentary by Migliore at al. (2021) recommends that contagious agalactia (CA) should only be diagnosed and confirmed when M. agalactiae is detected either by isolation or molecular methods. The other three mycoplasmas classically associated with CA (M. mycoides subsp. capri, M. capricolum subsp. capricolum and M. putrefaciens) should removed from the OIE Manual of Diagnostic Tests and Vaccines in Terrestrial Animals and associated sources.


For over thirty years, contagious agalactia has been recognized as a mycoplasma disease affecting small ruminants caused by four different pathogens: Mycoplasma agalactiae, Mycoplasma mycoides subsp. capri, Mycoplasma capricolum subsp. capricolum and Mycoplasma putrefaciens which were previously thought to produce clinically similar diseases. Today, with major advances in diagnosis enabling the rapid identification by molecular methods of causative mycoplasmas from infected flocks, it is time to revisit this issue. In this paper, we discuss and argue the reasons to support Mycoplasma agalactiae infection as the sole cause of contagious agalactia.

Migliore S, Puleio R, Nicholas RAJ, Loria GR. Mycoplasma agalactiae: The Sole Cause of Classical Contagious Agalactia? Animals. 2021; 11(6):1782.

A review of mycoplasma diagnostics in cattle

Journal of Veterinary Internal Medicine

The article by Parker et al., published in the Journal of Veterinary Internal Medicine provides an overview of the development and use of different diagnostic methods to identify mycoplasma species relevant to cattle, with a particular focus on Mycoplasma bovis.



Alysia M. Parker, Paul A. Sheehy, Mark S. Hazelton, Katrina L. Bosward and John K. House


Mycoplasma species have a global distribution causing serious diseases in cattle worldwide including mastitis, arthritis, pneumonia, otitis media and reproductive disorders. Mycoplasma species are typically highly contagious, are capable of causing severe disease, and are difficult infections to resolve requiring rapid and accurate diagnosis to prevent and control disease outbreaks. This review discusses the development and use of different diagnostic methods to identify Mycoplasma species relevant to cattle, with a particular focus on Mycoplasma bovis. Traditionally, the identification and diagnosis of mycoplasma has been performed via microbial culture. More recently, the use of polymerase chain reaction to detect Mycoplasma species from various bovine samples has increased. Polymerase chain reaction has a higher efficiency, specificity, and sensitivity for laboratory diagnosis when compared with conventional culture-based methods. Several tools are now available for typing Mycoplasma spp. isolates, allowing for genetic characterization in disease outbreak investigations. Serological diagnosis through the use of indirect ELISA allows the detection of antimycoplasma antibodies in sera and milk, with their use demonstrated on individual animal samples as well as BTM samples. While each testing method has strengths and limitations, their combined use provides complementary information, which when interpreted in conjunction with clinical signs and herd history, facilitates pathogen detection, and characterization of the disease status of cattle populations.

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Mycoplasmology: the big issues

logo oatSome  of  the  most  important  diseases  of  livestock  are  caused  by  mycoplasmas. The article by Nicholas et al., published in Animal Husbandry, Dairy and Veterinary Science provides a comprehensive overview of some of the important issues in animal mycoplasmology:

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