*3.1. Pulsed-Field Gel Electrophoresis Typing*

A total of 75 Salmonella isolates were typable, and 15 PTs were identified (Figure 1) and the PFGE banding pattern of all isolates were included in a dendrogram as the Supplementary Materials (Figure S2). The 10 nontypable (NT) isolates belonged to different serotypes; Salmonella Bolton (*n* = 1), *S.* Newport (*n* = 3), *S.* Typhimurium (*n* = 1), *S.* Hadar (*n* = 4), and *S.* Heidelberg (*n* = 1). For the majority of the typable isolates, there was a complete association between serotype and PT. The 21 typable *S.* Newport isolates all belonged to PT (H), but were isolated from several farms in all districts (Figure 1). Ciprofloxacin resistant isolates were the majority and most diverse in terms of serotypes, pulsotypes and geographic distribution. Four *S.* Mbandaka isolates were characterized by the same PT (N) and phenotypic resistance pattern, but were isolated from three different farms in two districts. A similar distribution pattern was also observed for 10 *S.* Aberdeen isolates of PT (F); these were isolated from nine different farms from all districts. However, the isolates were fully sensitive in the disc diffusion test. The exceptions from the serotype-PT associations were *S.* Hadar and *S.* Heidelberg. A total of seven *S.* Hadar isolates were typable. Four of them with identical PT originated from the same district, but from two farms, and had same phenotypic resistance towards three antimicrobials. The other three *S.* Hadar isolates had three different PTs, however, two of these isolates were similar with only one band difference (Figure S2). The typable *S.* Heidelberg isolates consisted of two different PTs; one PT (A) with two isolates from the same district and one PT (B) with seven isolates from the other two districts. The isolates in PT (A) were fully susceptible in the disc diffusion test, while all in PT (B) expressed ciprofloxacin resistance and two also expressed sulfonamide resistance.
