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Similar to the inltration patterns seen in the intestinal submucosa,
mesenterial lymph nodes also exhibit lymphoplasmacytic and
macrophage inltrations. However, the inammation’s intensity in
the lymph nodes has been described variably across studies, with
some reporting severe manifestations and others indicating milder
presentations [18, 23]. In the present investigation, the observed
patterns aligned with those from prior research. Additionally, it was
ascertained that the multibacillary form was present in almost all
studied animals, with lesions in the lymph nodes appearing less severe.
Cellular damage underpins the majority of diseases, and there’s a
prevailing theory that pathogens may directly or indirectly inict DNA
damage, especially in the case of infections [24, 25]. While various
studies have delved into the pathogenesis of MAP infection, the
complete understanding of its pathogenesis remains elusive. In an
attempt to elucidate this, past research on MAP infections in cattle,
sheep, goats, and camels primarily focused on proinammatory
cytokines, acute phase proteins, and oxidative stress parameters
[23, 26, 27]. Yet, there seems to be a gap in the literature regarding
DNA damage assessment in MAP infection.
In the present study, showcased the expression of γ–H2AX, a
biomarker indicative of double–stranded DNA breaks, in the case
of MAP infection. There is limited research utilizing γ–H2AX as a
biomarker in animals. For instance, Nakamura et al. [28] applied this
biomarker to identify DNA breaks in bovine lymphocytes post the
Fukushima disaster. Toyoda et al. [29] highlighted the DNA damage
in genotoxic urinary bladder cancers using γ–H2AX expression. Both
Fradet–Turcotte et al. [30] and Sakakibara et al. [31] postulated
that papilloma viruses induce DNA damage as evidenced by γ–
H2AX expression. Drawing parallels with previous studies, in the
this research underscores that MAP indeed induces DNA breaks in
affected tissues, as evidenced by γ–H2AX expression.
Infection–induced tissue damage triggers inflammation,
subsequently activating phagocytic cells. This activation gives rise to
the production of free radicals. These reactive oxygen species amplify
the extent of tissue damage. In the case of MAP infection, oxidative
stress markers such as Superoxide Dismutase (SOD), Malondialdehyde
(MDA), Glutathione (GSH), Nitric Oxide (NO), and Thiobarbituric Acid
Reactive Substances (TBARS) have been examined across various
animal species [23, 27, 32]. Yet, research pinpointing DNA oxidation
in MAP infection remains absent. The modern biomarker, 8–Ohdg, has
been employed to elucidate DNA oxidation in certain animal species
and varied diseases. For example, Karakurt et al. highlighted DNA
damage in ovine pulmonary adenocarcinoma using 8–Ohdg [33].
In a separate study, Karakurt underscored DNA oxidation in bovine
papilloma and bropapilloma via 8–Ohdg expression [34]. In the made
study, the occurrence of DNA oxidation in the case of MAP infection
was depicted through 8–Ohdg expression.
CONCLUSION
To effectively combat any disease and establish an impactful
treatment regimen, a thorough understanding of its pathogenesis
is imperative. Given the signicance of MAP infection, perceived as
a global threat affecting both animal and human health and resulting
in economic loss, this study illuminates that the causative agent
induces DNA breaks and oxidation in infected tissues. In made been
this research has pioneered the elucidation of the DNA damage
mechanism in MAP infection, marking a signicant contribution to
the global scientic community. In addition, this is the rst study
reported in the world to show the expression of γ–H2AX, a current
DNA damage marker, and 8–Ohdg, an important DNA oxidation
biomarker, in natural infection of Mycobacterium avium subspecies
paratuberculosis in goats.
Conict of interests
No conicts of interest for all authors are declared.
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