Transcriptomic Responses of Mycoplasma bovis Upon Treatments of trans-Cinnamaldehyde, Carvacrol, and Eugenol

Saurav Ranjitkar; Jingyue Ellie Duan; Kanokwan Srirattana; Fahad Alqahtani; Edan R Tulman; Ion Mandoiu; Kumar Venkitanarayanan; Xiuchun Tian

doi:10.3389/fmicb.2022.888433

Transcriptomic Responses of Mycoplasma bovis Upon Treatments of trans-Cinnamaldehyde, Carvacrol, and Eugenol

Front Microbiol. 2022 Jun 6:13:888433. doi: 10.3389/fmicb.2022.888433. eCollection 2022.

Authors

Saurav Ranjitkar¹, Jingyue Ellie Duan¹, Kanokwan Srirattana¹, Fahad Alqahtani², Edan R Tulman³, Ion Mandoiu⁴, Kumar Venkitanarayanan¹, Xiuchun Tian¹

Affiliations

¹ Department of Animal Science, University of Connecticut, Storrs, CT, United States.
² National Center for Bioinformatics, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia.
³ Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT, United States.
⁴ Department of Computer Science and Engineering, University of Connecticut, Storrs, CT, United States.

Abstract

Mycoplasma bovis (M. bovis) is an insidious, wall-less primary bacterial pathogen that causes bovine pneumonia, mid-ear infection, mastitis, and arthritis. The economic losses caused by M. bovis due to culling, diminished milk production, and feed conversion are underestimated because of poor diagnosis/recognition. Treatment with common antibiotics targeting the cell wall is ineffective. Plant-derived antimicrobials (PDAs) such as food-grade trans-cinnamaldehyde (TC), eugenol (EU), and carvacrol (CAR) are inexpensive and generally regarded as safe for humans and animals yet possess strong anti-bacterial properties. In preliminary studies, we found that all three PDAs inhibited the growth of M. bovis in vitro. Through RNA sequencing, we report here that CAR affected the expression of 153 genes which included the downregulation of energy generation-related proteins, pentose phosphate pathway, and upregulation of ribosomes and translation-related proteins. Few differentially expressed genes were found when M. bovis was treated with TC, EU, or when the three PDAs were double or triple combined. Our results suggest that, as opposed to the effect of CAR, the growth-inhibitory effects of TC and EU at levels tested may be exerted through mechanisms other than gene expression regulations.

Keywords: Mycoplasma bovis; RNA; carvacrol; eugenol; trans-cinnamaldehyde.