## 4 Discussion  
_Salmonella_ spp. are the main pathogens responsible for food zoonoses in both industrialized and developing countries [9, 21, 25, 26]. About 95% of salmonellosis affecting humans is attributable to the food vehicle; the spread is favored by the wide variety of infection reservoirs and the complexity of the agri-food production chains, both of animal and vegetable origin [27, 28]. Livestock has been implicated as a reservoir for antibiotic-resistant bacteria, and foods of animal origin can be vectors of transmission to humans [29]. The antibiotic resistance in _Salmonella_ spp. isolated from animal sources and from their meat has been widely demonstrated, even beyond the serovarities on which the attention of microbiologists and clinicians is focused [29]. In Italy, _Salmonella_ spp. strains showed higher resistance profiles than the European average, with sulfamethoxazole being ineffective in 44.9% of cases, followed by tetracycline (40.4%) and ampicillin (37.4%) [25]. Moreover, the latest EFSA report showed alarming values of resistance to the critically important antimicrobials, ciprofloxacin and cefotaxime and/or ceftazoline, of 18.9% and 23.5-31.6%, respectively [26]. The data gathered from the current survey showed that almost half of the serotypes of _Salmonella_ spp. isolated from biological samples showed resistance towards at least three antibiotics and, among the isolated serotypes, \(S\). Typhimurium, \(S\). Infantis, \(S\). Hadar, \(S\). Derby, and \(S\). Enteritidis showed the highest resistance. Noteworthy, 7 out of 10 _Salmonella_ \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & & & & & & & & \\ \hline _Salmonella_ serotypes & TEM & OXA & SHV & DHA & CTX-1 & CTX-2 & CTXM-4 & CMV-2 & EHXA \\ \hline \(S\). Typhimurium & + & - & - & - & - & - & - & - \\ \(S\). Corvallis & - & - & - & - & - & - & - & - \\ \(S\). Derby & + & - & - & - & - & - & - & - \\ \(S\). Hadar & + & - & - & - & - & - & - & - \\ \(S\). _salamae_ & + & - & - & - & - & - & - & - \\ \(S\). _houtenae_ & + & - & - & - & - & - & - & - \\ \(S\). Enteritidis & - & - & - & - & - & - & - & - \\ \(S\). Corvallis & - & - & - & - & - & - & - & - \\ \(S\). Infants & - & - & - & - & - & - & - & - \\ \(S\). Corvallis & - & - & - & - & - & - & - & - \\ \(S\). Derby & - & - & - & - & - & - & - & - \\ \(S\). Typhimurium & - & - & - & - & - & - & - & - \\ \(S\). Cardoner & + & - & - & - & - & - & - & - \\ \(S\). Veneziana & - & - & - & - & - & - & - & - \\ \(S\). Infants & - & - & - & + & - & - & - & - \\ \hline \hline \end{tabular}
\end{table} 
Table 3: ESBLs genotype of Salmonella strains. serotypes (i.e., _S._ Infants, _S._ Typhimuriumium (monophasic), _S._ Derby, _S._ Hadar, _S._ _salamae, S._ _houtenae, and S._ _Cardoner) were resistant to clinically important antibiotics such as sulfonamides, tetracyclines, diaminopyrimidines, penicillins, and quinolones, many of which are widely used in human and veterinary medicine. The decreased susceptibility to these conventional drugs suggests advising against their empirical use. Contrariwise, in agreement with previous studies [18; 30; 31], the third-generation cephalospororus herein tested (cefatoxime and ceftazidime) showed good effectiveness against _Salmonella_ spp., with a sensitivity of 100% in most investigated serotypes. In addition, high resistance was found in a less common _Salmonella_ serotype, namely the _S. enterica_ subspecies _salamae_, from pig farms, which showed resistance to five antibiotic classes, including ciprofloxacin. Although the use of ciprofloxacin in animal husbandry is reduced, the continuous evidence of the antimicrobial resistance of _Salmonella_ spp. towards this antibiotic are worrying. Worthy data gathered in the current study were the comparable antibiotic resistance profiles of some of the isolated _Salmonella_ serotypes. This finding seems to confirm the ability of bacteria to communicate, and therefore, to share information such as the ability to develop mechanisms to avoid the antibacterial action of certain molecules.