Salmonella Heidelberg is commonly reported in foodborne outbreaks around the world, and chickens and poultry products are known as important source of these pathogen. Multidrug-resistant S. Heidelberg strains are disseminated into poultry production chair, which can lead to severe clinical infections in humans and of difficult to treat. This study aimed at evaluating the β-lactam susceptibility and genotypic relatedness of Salmonella Heidelberg at Brazilian poultry production chain. Sixty-two S. Heidelberg strains from poultry production chain (poultry, poultry meat and poultry farm) were used. All strains were evaluated to antimicrobial susceptibility by diffusion disk test, as well as β-lactam resistance genes. Genotypic relatedness was assessed by Pulsed-Field Gel Eletrophoresis, using Xba1 restriction enzyme. Forty-one strains were characterized as multidrug-resistant according to phenotype characterization. The resistance susceptibility revealed 31 distinct profiles, with higher prevalence of streptomycin (61/62), nalidixic acid (50/62), tetracycline (43/62) and β-lactam drugs (37/62). bla_CMY-2 was the more frequent β-lactamase gene found (38/62); other resistance genes found were bla_CTX-M (2/62), bla_SHV (3/62) and bla_TEM-1 (38/62). No carbapenemase genes was found. The Pulsed-Field Gel Electrophoresis showed 58 different profiles. Strains with a larger number of antimicrobial resistance were grouped into ten major clusters apart from others. The spread of resistance by ampC continues to rise, thereby turning concern to public health, since the β-lactam antimicrobials are used as a therapeutic treatment in humans.

海德堡沙门氏菌在世界各地的食源性疫情中很常见，而鸡肉和家禽产品被认为是这些病原体的重要来源。多重耐药S .海德堡菌株传播到家禽生产椅中，可导致人类严重的临床感染且难以治疗。本研究旨在评估巴西家禽生产链中海德堡沙门氏菌的 β-内酰胺敏感性和基因型相关性。六十二S 。使用来自家禽生产链（家禽、家禽肉类和家禽养殖场）的海德堡菌株。通过扩散盘测试以及β-内酰胺耐药基因评估所有菌株的抗菌敏感性。使用Xba1限制性内切酶通过脉冲场凝胶电泳评估基因型相关性。根据表型特征，四十一个菌株被鉴定为具有多重耐药性。耐药敏感性揭示了 31 种不同的谱系，其中链霉素 (61/62)、萘啶酸 (50/62)、四环素 (43/62) 和 β-内酰胺类药物 (37/62) 的患病率较高。 bla _CMY-2是最常见的 β-内酰胺酶基因 (38/62)；发现的其他抗性基因有bla _CTX-M (2/62)、 bla _SHV (3/62) 和bla _TEM-1 (38/62)。未发现碳青霉烯酶基因。脉冲场凝胶电泳显示 58 种不同的曲线。具有较多抗菌素耐药性的菌株被分为十个主要簇。 由于 β-内酰胺类抗菌剂被用作人类的治疗方法， ampC耐药性的传播持续增加，从而引发了对公共健康的关注。