eISSN: 2672-7226 © Penerbit UMT Journal of Sustainability Science and Management Volume 17 Number 4, April 2022: 49-56 INHIBITION OF CORYNEBACTERIUM PSEUDOTUBERCULOSIS BIOFILM BY DNA SYNTHESIS AND PROTEIN SYNTHESIS INHIBITORS SYAIDA ANATI ABD RASHID¹, MOHAMAD FAKHRI YAACOB¹, MOHD SHAFIQ AAZMI¹, FAEZ FIRDAUS ABDULLAH JESSE² AND MOHD FAKHARUL ZAMAN RAJA YAHYA¹ , ³* 1 Faculty of Applied Sciences, Universiti Teknologi MARA Shah Alam, 40450 Shah Alam, Malaysia. 2 Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Malaysia. 3 Molecular Microbial Pathogenicity Research Group, Pharmaceutical and Life Sciences Community of Research, Universiti Teknologi MARA. *Corresponding author: fakharulzaman@uitm.edu.my Submitted fnal draft: 11 November 2021 Accepted: 29 November 2021 Introduction Corynebacterium pseudotuberculosis is a Gram- positive bacterium and one of the signifcant veterinary pathogens. The bacterium not only causes caseous lymphadenitis (CLA) in small ruminants but also causes other chronic diseases such as ulcerative lymphangitis in horses and bovine mastitis. CLA is well known to affect sheep and goats leading to the decrease in wool production, weight loss and carcass condemnation thus causing great economic loss to livestock industry (Dorellaa et al., 2006; Shi et al., 2019). C. pseudotuberculosis can survive several weeks in environment and spread within the fock or herd. The contamination of superfcial wounds which may be caused by several procedures such as shearing, ear tagging and castration often increases the probability of the transmission among the animals. The formation of the abscess in superfcial lymph nodes and subcutaneous tissue is the common external form of CLA. Meanwhile, the visceral form of CLA is shown by the abscess formation in internal organ such as kidney, spleen, liver and lungs. The uses of antibiotic in controlling the CLA infection is a hard task as the bacteria stay protected inside the abscess which encapsulated it (Ilhan, 2020). Bioflm represents a major bacterial growth mode. Extracellular matrix which contains a wide variety of proteins, glycoproteins and glycolipids that surrounds the bioflm cells plays role in cellular attachment to surface, stabilization of the overall bioflm structure and protection against the antimicrobial regime. Development of bioflm begins with attachment of bacteria to the surfaces, followed by the formation of microcolony, bioflm maturity and fnally bioflm dispersion (Johari et al., 2020). It has been established that diffculty in Abstract: Corynebacterium pseudotuberculosis represents the causative factor of caseous lymphadenitis, a ruminant disease that contributes to major economic loss in most sheep farming countries. The present study was performed to determine the effcacy of DNA synthesis (nalidixic acid) and protein synthesis inhibitors (streptomycin and tetracycline) on C. pseudotuberculosis bioflm. Bioflm of C. pseudotuberculosis clinical isolate was developed in the fat-bottom microplate. Field-emission scanning electron microscope and resazurin assay were used to investigate the structure and antimicrobial susceptibility of C. pseudotuberculosis bioflm, respectively. All test inhibitors were evaluated in the range between 3.125 µg/ml and 100 µg/ml. Results demonstrated that C. pseudotuberculosis bioflm formed a three dimensional and heterogeneous structure on the surface. The highest bioflm percentage inhibition shown by nalidixic acid, streptomycin and tetracycline were 71.57%, 87.44% and 74.73%, respectively. Signifcant (p<0.05) correlation of antibioflm susceptibility between these inhibitors and other antimicrobials were also demonstrated herein. The fndings of the present study suggest the potential use of streptomycin for the control of caseous lymphadenitis. Keywords: Corynebacterium pseudotuberculosis, bioflm, caseous lymphadenitis, antibioflm susceptibility. http://doi.org/10.46754/jssm.2022.4.004