الفهرس 
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Abstract
After the discovery of antibiotics, it was thought that the battle against microorganisms was won. However, it was found that bacteria can develop a resistance structure referred as biofilms.
Staphylococcus aureus, especially drug resistant ones such as MRSA is one of the most common bacteria found on human epidermis and it can disseminate to other areas of the body. Once, it is transmitted to the circulatory system, planktonic growth and up regulation of adherence factors occurs. Moreover, domestic pets, livestocks, wild birds, and other animals have recently been identified as carriers of MRSA in several countries and settings. Staphylococcus aureus represent also one of the causative agents of food infection as it is responsible of intoxication.
For all these reasons, understanding S. aureus biofilm production is necessary in order to evaluate and apply new strategies to inhibit or eradicate biofilm formation.
Therefore, the main objective of this study was to evaluate the effects of zinc oxide nanoparticles, proteinase K enzyme and HAM compound as various modalities of anti-biofilm approaches on the biofilm matrices of clinical MDR and MRSA isolates.
Out of 200 analyzed samples, 156 were contaminated with Staphylococcus species (78%), 111 (55.5%) isolates were S. aureus and the other 45 (22.5%) were CoNs. Animal samples were highly impured with S. aureus than human samples (89 and 67%, respectively) and sputum exhibited the highest contamination rate of S. aureus (71.43%).
All the recovered isolates were confirmed phenotypically using standard microbiological techniques. Phenotypic characterization of slime production among all recovered S. aureus isolates revealed that 27.03% yielded strong black colonies, 68.47% exhibited black colonies and 4.50% demonstrated red colonies onto CRA and via MTP method, the isolates exhibited 3 adherence levels; strong, moderate and weak with percentages of 27.02, 42.34 and 26.13%, respectively.