Dados do Trabalho

Título

EXPLORING THE COEXISTENCE OF PATHOGENIC AND SPOILAGE MICROORGANISMS WITH THE POTENTIAL FOR MULTISPECIES ADHESION

Introdução

The complex community of microbial biofilms is adapted to develop and disperse in hostile environments and to adhere to industrial surfaces. The concerning fact is that these communities develop considerable resistance to bactericidal and bacteriostatic agents used in the food industry. Given the urgent need to elucidate the biofilm-producing ability and synergism of multispecies biofilms, the present study aimed to evaluate the effect of pathogenic and spoilage microorganisms co-culture on planktonic growth and adhesion ability.

Material e Métodos

Therefore, binary combinations (n=28) were evaluated between Bacillus cereus ATCC 14579 (BC); Cronobacter sakazakii P4496; Escherichia coli ATCC 25922; Listeria monocytogenes ATCC 19114 (LM); Pseudomonas aeruginosa ATCC 27853 (PA); Salmonella Enteritidis ATCC 13076; and Staphylococcus aureus ATCC 25923 (SA). Monocultures and combined cultures were inoculated (10⁶ CFU/mL) in TSB broth and incubated at 33 °C for 24 hours. All measurements were carried out in triplicate. Planktonic growth was evaluated using the turbidimetric method (600 nm), while the adhesion ability was measured using the crystal violet microtiter plate assay (570 nm). The experiment was conducted in two independent replicates and the bacterial adhesion potential in co-culture was compared to monocultures using the t-test (p<0.05).

Resultados e Discussão

When comparing OD₆₀₀ values of monocultures (0.08 to 1.34) with co-cultures (0.64 to 1.69), cooperation in planktonic growth was confirmed in all binary combinations, except between LM-SA, demonstrating significant interspecies synergism. Regarding adhesion, all binary co-cultures showed superior results when compared to the respective monocultures. Nonetheless, the BC-LM and BC-PA combinations were the only ones that showed a significant increase when compared to monocultures, this being of 5.2 and 2.4 times, respectively. It is also noteworthy that the BC-LM and BC-PA potential for adhesion did not differ significantly from each other (p=0.794). The concomitant presence of different microorganisms can facilitate the formation of robust biofilms that can increase tolerance to sanitizers, favoring their survival and persistence, with consequent compromise of food quality and safety throughout processing.

Conclusão

The bacterial combinations with greater synergism found in this study can be applied in subsequent biofilm eradication trials and, thus, in the development of more efficient sanitization protocols.