A
study coordinated by researchers from Universidad
CEU San Pablo, from the Virology and Innate Immunity Groups (VII), and
MICROAMB-Environmental Bacterial Biotechnology, together with researchers from
the Geneva Center of Inflammation
Research, the School of Medicine at the University of Geneva and the Icahn School of Medicine at Mount Sinai
Hospital in New York have published a paper in the American Association for
Microbiology's journal Microbiology Spectrum demonstrating
that infection with the influenza A virus changes the lung and gut microbiota.
This, in turn, affects its resistance to common antibiotics such as those used
for ear or throat infections.
The
analysis also reveals that, during the first days after infection, the ability
of the gut microbiota to metabolise sugars is reduced, something that is
recovered five to seven days later. As one of the main authors, virologist Estanislao Nistal, explains that: “We have analysed changes related to
antibiotic resistance in gut bacterial communities of mice infected with a flu
virus. It has been observed that resistance to families of antibiotics as
common as cephalosporins that are used for ear and throat infections,
pneumonia, or meningitis, among other diseases, temporarily increases in the gut
microbiota”.
“Traditionally, the study of antibiotic
resistance is carried out using populations of bacteria isolated from a
patient. Our approach studies this resistance in bacterial communities, in
which many bacteria together determine the resistance of the community. This
strategy would allow a better choice of antibiotics in more individualised
treatments. Knowing the behaviour of a microbial community (such as gut
bacteria) could allow us to anticipate therapeutic failure due to the
application of an ineffective antibiotic for a patient”, explains Pedro Jiménez, co-lead author of the
study.
Knowledge
of antibiotic resistance in bacterial communities has been limited due to the
complexity associated with its interpretation. Resistance to a given antibiotic
can vary depending on which bacteria and which resistance mechanisms are
present in a community. This study shows that influenza infections not only
alter the composition of the gut microbiota, but also its metabolic capacity
and response to certain antibiotics. Diseases affecting the gut microbiota can
alter its activity and metabolic function, including resistance to orally
administered antibiotics. “Functional
characterization of these complex communities is essential, although currently
it is largely limited to taxonomic descriptions. Knowing the functional changes
could significantly influence treatment strategies, especially in infections
caused by several microbes at the same time,” explain Marina Robas and Jesús Presa,
first signatories of the study.
Some
organs in our body host a complex and dynamic microscopic world known as the
microbiota, where bacteria play a key role. “Thanks
to advanced genomic sequencing techniques, we can now identify the bacteria
present in our body, even those that are difficult to study in the laboratory
due to their resistance to being cultured; in
this study we propose techniques to study their 'group response', beyond their
traditional use
”, states Nistal.
This
advance has served to improve the treatment of inflammatory bowel diseases such
as Crohn's disease and ulcerative colitis, and is transforming our
understanding of dysbiosis and its relationship with conditions such as
neurological diseases and cancer, among others. However, despite being able to
know which bacteria are present, most research does not focus on what
determines their group behaviour and its consequences. This study goes a step
further by trying to understand how bacteria behave in groups, something that
remains a challenge, especially when trying to interpret the relationship
between such behaviour and its connection to different diseases and the
way to treat them.
More information:
Robas M, Presa J, Arranz-Herrero J, Yildiz S,
Rius-Rocabert S, Llinares-Pinel F, Probanza A, Schmolke M, Jiménez PA,
Nistal-Villan E. Influenza A virus infection alters the resistance profile of
gut microbiota to clinically relevant antibiotics. Microbiol Spectr. 2023 Dec 5:e0363522. doi:
10.1128/spectrum.03635-22. Epub ahead of print. PMID:
38051056.