The objective of this experiment was to study contagious mastitis pathogen effects on Iranian white cheese properties. Iranian white brine cheeses (2 trials) were made by healthy and containing pathogen bulk tank milk. All types of cheese were ripened at 13 °C for 2 weeks and at 6 °C to the end of ripening period. Cheeses were analyzed for the composition, color, lipolysis and proteolysis. The cheese of each trial was sampled at 1 and 60 days during ripening. No significant differences were observed between the fat, protein, ash and moisture contents of manufactured cheeses. Color parameters, lipolysis and proteolysis indices were not significantly different in two cheese groups. Therefore, incidence of Staphylococcus aureus, Streptococcus agalactiae, Corynebacteria spp and Mycoplasma spp in bulk milk tank does not change the physicochemical properties of Iranian white cheese. Despite the potential of these pathogens to cause health problems for consumers, they do not alter the characteristics of the cheese. [ABSTRACT FROM AUTHOR]