Soft rot and blackleg, caused by Pectobacterium and Dickeya species, are destructive diseases that affect potato crops worldwide, resulting in significant economic losses. These pathogens can cause blackleg in plants and induce soft rot in tubers. Managing these diseases is challenging due to a lack of effective control methods and the high susceptibility of most potato cultivars. Biological control presents a promising alternative. However, some antagonistic microorganisms may be potential plant pathogens or interact synergistically with pathogenic bacteria or fungi. Understanding these complex interactions is crucial for developing effective strategies to enhance potato health and yield. These pathogens serve as valuable models for studying the interactions between pathogens. This study examined microbial interactions on two potato cultivars, La Strada and Red Scarlet, under controlled in vitro conditions. Potatoes were inoculated with bacterial strains Dickeya dianthicola (F014), Pectobacterium brasiliense (F126), Pseudomonas syringae (Ps3004), Serratia marcescens (Sm2018), and Escherichia coli (EcM14), both separately and in pairs. A 0-9 scoring system was used to assess the effects on potato health. Results showed distinct interaction patterns, identifying both beneficial (synergistic) and harmful (antagonistic) relationships. For instance, co-inoculation of F126 with either Ps3004 or Sm2018 positively influenced potato response. When F126 and Ps3004 were combined, the disease score was high at 8.00, indicating a synergistic effect. Conversely, strong antagonistic interactions were also observed. F014 displayed antagonism with Ps3004, Sm2018, and EcM14. F014 and Ps3004 pair, being the most severe, had a score of only 1.00. The study also found that potato cultivars responded differently to bacterial combinations. Red Scarlet had a disease score of 4.00 when inoculated with Sm2018 alone, while La Strada scored 0.00, indicating low susceptibility. These findings are crucial for developing targeted biological control agents, enabling the use of beneficial microbial combinations and avoiding harmful ones to enhance crop resilience and production.