This study aimed to determine the prevalence and diversity of extended-spectrum β-lactamase (ESBL)-producing and multidrug-resistant (MDR) Escherichia coli and Klebsiella pneumoniae isolates from 136 broiler livers randomly purchased in 136 retail markets in Djelfa (Algeria). Isolation was performed on Hektoen agar and bacterial identification was carried out by API20E system and Maldi-TOF-MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry). Antimicrobial susceptibility was tested by the disk diffusion and agar dilution methods. Detection of ESBLs and other resistance and integron genes, phylogenetic grouping, and molecular typing was performed by PCR and sequencing. Seventy-eight isolates (one per positive sample) were recovered: 73 E. coli and 5 K. pneumoniae. Among E. coli, 86.3% of isolates were MDR. ESBL activity was revealed in eight E. coli and five K. pneumoniae isolates (rates of 5.9% and 3.7% in analyzed samples, respectively). ESBL genes detected among E. coli were as follows (number of isolates): bla_CTX-M-15 (3), bla_CTX-M-1 (3), bla_CTX-M-55 (1), and bla_SHV-12 (1); all ESBL-producing K. pneumoniae isolates carried the bla_CTX-M-15 gene. ESBL-producing E. coli isolates were assigned to lineages (phylogroup/sequence type and number of isolates in parenthesis): A/ST48 (1), B1/ST6448 (1), B1/ST5087 (3), B1/ST23 (1), and B2/ST131 (two bla_CTX-M-15E. coli isolates). K. pneumoniae isolates were ascribed to sequence types ST2010 and ST3483. Regarding the 65 non-ESBL E. coli isolates, the most observed resistance genes were as follows: tet(A) (75%), bla_TEM (57.1%), and sul2 (43.5%). Class1 integrons were revealed in seven non-ESBL E. coli isolates (10.7%) and two gene-cassette arrays were identified: dfrA1 and aadA1+dfrA1. Our study provides evidence that broiler-derived food from Center of Algeria constitutes a source of ESBL and/or MDR-producing Enterobacteriaceae, with detection of relevant ESBL genes and epidemic clones.

中文翻译：

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来自阿尔及利亚中部肉鸡肝脏的产超广谱 β-内酰胺酶的大肠杆菌和肺炎克雷伯菌，检测大肠杆菌中的 CTX-M-55 和 B2/ST131-CTX-M-15

本研究旨在确定产超广谱 β-内酰胺酶 (ESBL) 和多重耐药 (MDR) 的大肠杆菌和肺炎克雷伯菌分离株的流行率和多样性，这些分离株来自在 Djelfa（阿尔及利亚）的 136 个零售市场随机购买的 136 只肉鸡肝脏。在Hektoen琼脂上进行分离，通过API20E系统和Maldi-TOF-MS（基质辅助激光解吸/电离飞行时间质谱）进行细菌鉴定。通过圆盘扩散和琼脂稀释方法测试抗菌敏感性。ESBLs 和其他抗性和整合子基因、系统发育分组和分子分型的检测通过 PCR 和测序进行。回收了 78 个分离株（每个阳性样本一个）：73 个大肠杆菌和 5 K. 肺炎。在大肠杆菌中，86.3% 的分离株是 MDR。ESBL 活性在 8株大肠杆菌和 5株肺炎克雷伯菌e 菌株中被发现（在分析样品中的比率分别为 5.9% 和 3.7%）。在大肠杆菌中检测到的 ESBL 基因如下（分离株数）：bla _CTX-M-15 (3)、bla _CTX-M-1 (3)、bla _CTX-M-55 (1) 和bla _{SHV- 12} (1); 所有产 ESBL 的肺炎克雷伯菌分离株都带有bla _CTX-M-15基因。产 ESBL 的大肠杆菌分离株被分配到谱系（系统群/序列类型和括号中的分离株数）：A/ST48 (1)、B1/ST6448 (1)、B1/ST5087 (3)、B1/ST23 (1) 和 B2/ST131 （两个bla _CTX-M-15大肠杆菌分离株）。肺炎克雷伯菌分离株归属于序列类型 ST2010 和 ST3483。对于 65 个非 ESBL大肠杆菌分离株，观察到的最多的抗性基因如下：tet (A) (75%)、bla _TEM (57.1%) 和sul2 (43.5%)。在 7 个非 ESBL大肠杆菌分离株（10.7%）中发现了 Class1 整合子，并确定了两个基因盒阵列：dfrA 1 和aadA 1+dfrA 1. 我们的研究提供的证据表明，来自阿尔及利亚中心的肉鸡衍生食品构成了产生 ESBL 和/或 MDR 的肠杆菌科的来源，并检测了相关的 ESBL 基因和流行性克隆。