## 4 Discussion  
_Salmonella_ Typhimurium, _Salmonella_ Newport, _Salmonella_ Enteritidis, and _Salmonella_ Javiana are some pathogens that were identified as the cause of fresh-produce-related outbreaks of foodborne diseases [2, 28]. In addition, _Salmonella_ serotypes have the ability to generate biofilms within the food industry [14, 29]. However, certain serotypes have developed resistance to current antibiotics [7, 30]. Therefore, understanding the mechanism of resistance and tolerance to antibiotics allows the development of more efficient therapeutic treatments for the removal of a biofilm [31]. In our study, 49.45% of _Salmonella_ serotypes isolated from fruits were multidrug resistant to ampicillin, carbenicillin, amikacin, and ciprofloxacin (Table 1). From previous research, it is evident that _Salmonella_ serotypes have different resistance profiles or antimicrobial susceptibility. [PERSON] and [PERSON] [32] showed 100% resistance to ampicillin and susceptibility to amikacin, carbenicillin, ciprofloxacin, cefotaxime, and gentamicin in _Salmonella_ spp. isolated from salad vegetables, fruits, and sprouts. [PERSON] et al. [33] showed high (67.5%) multidrug resistance to ciprofloxacin, sulfamethoxazole-trimethoprim, ampicillin, and streptomycin in _Salmonella_ spp. isolated from chicken. However, this study differs in the data for resistance and/or susceptibility to antimicrobials such as amikacin, carbenicillin, ciprofloxacin, cefotaxime, gentamicin, and sulfamethoxazole-trimethoprim. The heterogeneity in antimicrobial resistance patterns observed among _Salmonella_ serotypes could be related to the long-term use of antibiotics as growth promoters in animals, the protection of crops, and poor hygiene practices, which have contributed to antimicrobial resistance [30, 34, 35]. Additionally, 95.6% of the _Salmonella_ serotypes were strong biofilm producers and 4.39% were weak biofilm producers; however, the _Salmonella_ strains (five serotypes) had differences in their biofilm formation on polystyrene (\(p<0.05\)) in this study. Similarly, other studies have reported high biofilm formation (66.3-67.5%) by _Salmonella_ spp. isolated from humans, animals, or food [5, 33]. [PERSON] et al. [36] reported that 50% of _Salmonella_ spp. isolated from different fruits and vegetables were strong biofilm producers/ while the rest were found to be moderate or weak biofilm producers. [PERSON] et al. [37] showed that _S._ Heidelberg and _Salmonella_ Typhimuriumurium (turkey isolate) produced less biofilms than _Salmonella_ Typhimurium (chicken isolate) did in 1/10 TSB at 30 \({}^{\circ}\)C on polystyrene. Likewise, [PERSON] et al. [38] reported significantly greater biofilm formation at 22 \({}^{\circ}\)C in comparison to 37 \({}^{\circ}\)C by monophasic _Salmonella_ Typhimurium and _Salmonella_ Typhimuriumurium isolated from pig feces, feed, water, and the farm environment, including floors, walls, water drinkers, and troughs. However, [PERSON] et al. [39] showed that _Salmonella_ serotypes  
Figure 3: Scanning electron microscopy (SEM) micrographs of mono-species biofilm development on polypropylene type B (PP). Biofilms were developed at 35 \({}^{\circ}\)C for 240 h with replacement of culture medium (TSBS or TSBA) at 120 h. (**A**): TSBS organic matter on PP; (**B**): TSBS organic matter and EPS on PP; (**C**): biofilms of _Salmonella_ Newport-6 on PP in TSBS; (**D**): biofilms of _Salmonella_ Rubislaw-1 on PP in TSBS. produced stronger biofilms as the temperature of incubation increased from 10 to 37 \({}^{\circ}\)C in 1/20 TSB (\(p>0.05\)). Consequently, the low correlation (0.121) between _Salmonella_ strains (five serotypes) forming a biofilm and multidrug resistance in our study may be related to the serotype, the source from which strains were isolated (such as water, type of food, farm environment, etc. ), the biofilm formation ability, or the excessive use of antibiotics.