## 3 Results  
The 15 isolates were assigned to the species _Salmonella enterica_ and to the subspecies _enterica_ (13 isolates), (one isolate), (one isolate). Antigenic profiles were identified for _S. salamae_ (O:1,23,22;-) and _S. houtenae_ (O:43:z4,z23). Different serovars belonged to the 13 Salmonella of subspecies enterica: Typhimurium (two isolates), Corvallis (three isolates), Derby (two isolates), Hadar, Enteritidis, Infants (two isolates), Cardoner, Veneziana. Table 2 shows the Salmonella serotypes, the host, and the source from which they were collected.  
\begin{table}
\begin{tabular}{l l l l l} \hline \hline  & **Target Gene** & **Primer Sequence (5\({}^{\prime}\)\(\rightarrow\) 3\({}^{\prime}\))** & **Amplicon Size (bp)** & **Ref** \\ \hline \multirow{10}{*}{Set 1} & CTX-M IV F & GACAAAGAGAGTGCAACGGATG & & \\  & CTX-M IV R & TCAGTGCGATCCAGAGAGA & & 501 & \\  & TEM F & AGTGCTATCCCATGAGGTG & & \\  & TEM R & CTGACTCCC GTGCGTGTAGATA & & 431 & \\  & OXA F & ATTATCATACAGAGCGCGCAG & & [23] \\  & OXA R & TGCATCCAGCTTTG & & 296 & \\  & SHV F & ATTATCTACAGCGGCCCAGTG & & \\  & SHV R & CGCTGTATCGCTCATG & & 214 & \\ \hline \multirow{10}{*}{Set 2} & CMV II F & AGCGATCCGGTCACGAAATA & & \\  & CMY II R & CCCGTTTATG CACCCATGA & 695 & \\  & CTX M I F & TCCAGAATAAGGAAATCCGGG & & \\  & CTX M I R & TGCTTATCCAGGGTCAGAT & & [23] \\  & CTX M II F & ACCGCGGAATATTGCGCAGAT & & \\  & CTX M II R & GATATCGTTGGTGGCATA & & 588 & \\  & DHA F & GTGGGTGGACAGCACCATAAA & & \\  & DHA R & CCTGCGGATAGGTCCAGAT & & 314 & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Target gene, sequence, and amplicon size of forward and reverse primers used for the two separate multiplex PCR reactions (Set 1 detecting \(\beta\)-lactamases blaCTX-M IV, TEM, OXA, and SHV; Set 2 detecting the \(\beta\)-lactamases blaCMY II, CTX-M I, CTX-M II, and DHA).  
The antibiotic sensitivity test showed that the _Salmonella_ strains isolated from the analyzed biological samples were all resistant to a variable degree. All 15 resistant strains showed resistance to at least two classes of antibiotics and 14 (93.3%) strains were multiresistant, i.e., resistant to more than three classes of antibiotics, particularly the serotypes \(S\). Typhimurium, \(S\). Infantis, \(S\). Hadar, \(S\). Derby, \(S\). Enteritidis, \(S\). _houtenae_, \(S\). _salamae_, and \(S\). Cardoner. Moreover, seven serotypes showed high resistance values (100-47%) to the following molecules: sulfonamides, tetracyclines, diaminopyrimidines, penicillins, macrolides, and quinolones (Table 2).  
The overall incidence of ESBLs-producing isolates was 46.66% (7/15) (Table 3). All isolates that tested positive for ESBLs were also resistant to more than four antibiotics (multi-drug resistance). Molecular analyses showed that the gene for \(\beta\)lactamase, blaTEM, was present in six serotypes of _Salmonella_, in particular \(S\). Typhimurium (monphasic) and \(S\). Derby, isolated from swine meat and feces samples; \(S\). Hadar isolated from insects; \(S\). _salamae_ isolated from an abrasive sponge on swine skin; \(S\). _houtenae_ isolated from chicken skin; and \(S\). Cardoner isolated from chicken meat. Meanwhile, blaCTX-M 1 was found in \(S\). Infantis isolated from chicken meat.