BIOFILM FORMATION IN EGGSHELL BY Salmonella Gallinarum MULTIRESISTANT AND SUSCEPTIBLE TO BACTERIOPHAGE

Fowl typhoid is a systemic disease, occurring mainly in adult chickens, whose etiologic agent is Salmonella Gallinarum (SG). Transmitted by horizontal-transmission or transovarial routes, can be characterized by penetration through eggshell soon after laying, in laying nest, in litters or in hatcheries, for providing favorable environmental conditions to the pathogen. The research sought to evaluate the ability of SG to form biofilm in commercial breeders-eggshell, and also evaluate it removal by chemical disinfection. Multiresistant, biofilm former and susceptible to bacteriophage action SG sample was used. Ten commercially hygienized breeders-eggs were immersed in 107 UFC/mL bacterial suspension (SG) for 30 min, left to dry for 1 h and incubated at 36±1°C, 22±1°C and 42±1°C for 24 h in sterile sachets. Eggs were removed from planktonic cells by rinsing with AP 0.1%, packed in new sachets with 30 mL AP 0.1% and sonicated for 10 min for sessile cells removal, and SG were quantified by drop plate method. About 10 mL of disinfectant (hydrogenated potassium sulfate, sodium dodecylbenzene sulfonate, potassium monopersulfate, potassium sulfate, sulfamic acid), in concentration of 1.5%, was dispensed into five eggs for each temperature for 5 min. For planktonic cells removal, and cease disinfectant activity, 0.1% AP was used with neutralizing agents, and after, SG were quantified by the drop plate method. There was higher biofilm formation in eggshells at a temperature of 22°C (4.656 log10UFC/cm2), with a statistical difference when compared to biofilms formed at 36°C and 42°C. Hatching room and breeding farm remain in the temperature range of 22°C. Commercial disinfectant promoted biofilm removal only at 22°C, leading to a reduction of 3.125 log10. The higher biofilm formation at 22°C may be related to the adaptation of SG to this temperature, because in inhospitable conditions, biofilm formation capacity can guarantee its survival in the environment. At 42°C there is no need for SG to leave the planktonic form to sessile form, because this is body temperature in the chicken, being a factor that leads to a lower biofilm formation. This SG is multiresistant to antimicrobials, however, undergo lytic action by bacteriophages, leading us to a favorable path for the sanitary control of this microorganism.