The North Carolina One Health
Intellectual Exchange Group was pleased to host Ricardo Maggi, MS, Ph.D., a
well-travelled and highly respected researcher of microbiology and vector borne
pathogens. Dr. Maggi earned his
Doctorate from the University
of Puerto Rico Milan , he now calls North Carolina home. Currently, Professor Maggi is Co-Director of
the Vector Borne Diseases Diagnostic Laboratory at North Carolina State
University’s College of Veterinary Medicine.
There Dr. Maggi and his team aim to develop and implement cutting edge
methods and technologies to improve the diagnosis of vector-borne
pathogens.
Dr. Maggi related with the audience
the importance of conducting research on hemotrophic mycoplasmas, and their
relevance in combating pathogenic potential in both animals and humans. Hemotrophic mycoplasmas are epierythrocytic
obligate bacteria, so evolutionary pressures have given these bacteria the
opportunity to spread with the employ of arthropods as vectors. While the ticks feed on their host, the
hemoplasmas have been provided a route to another more suitable host. Dr. Maggi explained to the Exchange Group how
infections with hemoplasmas are often regarded as chronic and largely asymptomatic,
so the optimal method of detecting infection would be through serology. Cytological examination of stained blood
smears under light microscopy had been the primary method of detecting hemoplasmas
in veterinary medicine, although there were limitations such as the proper categorization
of the many mycoplasma varieties. Dr.
Maggi and his research team have developed methods to categorize hemoplasmas
based on their genetic makeup. The
polymerase chain reaction (PCR), a biochemical technique used to amplify targeted
sections of DNA, has proven to be a viable analytical tool in the proper
identification of hemoplasmas.
The gene sequences recognized and
used by Dr. Maggi’s research team in the analysis and identification of
hemoplasma subclusters is 16S rRNA.
These sequences are present in the Mycoplasma
suis and Mycoplasma hemofelis
groups. This was an important step in
the organization of the bacteria because what was found was the tip of the
hemoplasma ice burg. Dr. Maggi then
explained to the Exchange how the M. suis
and M. haemofelis subcluster included
varietals that affected many animals that humans have established domestic or
other relationships with. Because of the
genetic similarities of the 16S rRNA gene sequence similarities within the members
of the two aforementioned subclusters, the bacteria may be best categorized by
the host that it has invaded.
Noting the breadth of research in
the proper analysis of mycoplasmas, Dr. Maggi spoke about the prevalence of the
bacterial infections in many species.
The test subjects were sourced from many regions of the world on
location. Some of these animals and
respective regions included dogs from Greece
and domestic cats from the United
States .
Although many animals did not display any signs of infection, in some
animals hemoplasma infection was associated with hemolytic anemia of variable
degrees of severity. Comparative
immunology was also evaluated between selected primates and humans. In all, research suggests that hemotrophic
mycoplasmas are very adaptable organisms.
They have the ability to change to fit the physiological profiles of
their respective hosts. For this reason
Dr. Maggi expressed the importance of recognizing mycoplasmas as emerging
zoonotic pathogens.
The challenge in researching the
pathogen lies in the lack of “respect” for these tick-borne pathogens in the
greater healthcare and government institutions.
Because ticks are largely isolated in heavily-wooded areas, the
potential for human infection is greatly reduced. This is especially so in urban areas, where
ticks typically do not inhabit except through the means of a travelling
host. Dr. Maggi stressed the importance
of educating the larger community of the dangers of tick-borne mycoplasmas, and
the role researchers in many disciplines may play in combating the
pathogen. This includes creative means
of attracting the proper funding to control the spread of the tick-borne
diseases. Ticks are very slow moving in
nature, and do not travel great distances from their native regions except by
latching on to a host or through other artificial transit modes.
Another important point brought up
in discussion was the growing trend to globalize markets. Many livestock and other goods are
transported to different countries, and a consequence may also be the transport
of ticks and other organisms carrying pathogens. The education of animal handlers and health
workers in the proper detection and removal of ticks is essential in combating
hemoplasmas. More importantly, once the
obvious obligate has been identified, it is essential to properly screen the
inhabitants for the presence of hemoplasmas.
Dr. Maggi concluded his discussion with the students of One Health with
a charge to expand on the research already done on mycoplasmas, a largely
underappreciated pathogen with the potential to harm many species. Perhaps comparative immunology may provide
perspective on a species that is resistant to the bacteria, and may provide a
vaccine. Perhaps there may be an
arthropod species that resists the invasion.
Dr. Maggi stresses the constant transparency and collaboration between
human and veterinary medical disciplines, along with the cooperation of
environmental and governmental agencies in identifying risk factors associated
with mycoplasmas, and measures to prevent infection of a silent pathogen.
Cedric Harvey
NCSU
Senior, Biological Sciences-Human Biology
