Béjaoui Awatef, Gharbi Manel, Bitri Sarra, Nasraoui Dorsaf, Ben Aziza Wassim, Ghedira Kais, Rfaik Maryem, Marzougui Linda, Ghram Abdeljelil, Maaroufi Abderrazek
Laboratory of Epidemiology and Veterinary Microbiology, Group of Bacteriology and Biotechnology Development, Institut Pasteur de Tunis, University of Tunis El Manar (UTM), Tunis 1002, Tunisia.
Laboratory of Bioinformatics, Biomathematics and Biostatistics, Institut Pasteur de Tunis, University of Tunis El Manar (UTM), Tunis 1002, Tunisia.
Antibiotics (Basel). 2022 Jun 21;11(7):830. doi: 10.3390/antibiotics11070830.
Antibiotic resistance in foodborne pathogens is an emergent global health concern. The objectives of this study were to assess antimicrobial resistance (AMR) in isolates from chicken carcasses and to investigate the AMR molecular mechanisms as well as the presence of virulence determinants. The study was performed on 257 samples collected from abattoirs and retail shops in northeastern Tunisia. Forty-eight isolates were recovered and identified as (n = 33) and (n = 15). Antibiotic resistance was tested against eight antibiotics and high resistance rates were observed against tetracycline (100%), erythromycin (97.9%), ciprofloxacin (73%), nalidixic acid (85.4%), ampicillin (83.3%), amoxicillin/clavulanic acid (22.9%), chloramphenicol (75%), and gentamicin (27.1%). All isolates were multidrug-resistant, and 22 resistance patterns were found. All isolates were screened for AMR genes ((), (), (), (), , , , and ), and for point mutations in (C257T substitution) and (A2075G/A2074C) genes. All screened AMR genes, as well as the C257T and the A2075G mutations, were detected. The virulence genotypes were also determined, and all isolates carried the motility () and invasion () genes. Most of them also harbored the , , and genes, encoding the toxin. The screening of the and the genes, involved in Guillain-Barré Syndrome expression, revealed the presence of the in 21.2% of strains, whereas none of them carried the gene. Our findings highlight the emergence of strains simultaneously harboring several virulence and AMR determinants, which emphasizes the risk of transmission of MDR strains to humans via the food chain. Hence, controlling the dissemination of foodborne pathogens "from the farm to the fork" as well as restricting the use of antimicrobials in husbandry are mandatory to prevent the risk for consumers and to mitigate the dissemination of MDR pathogens.
食源性病原体中的抗生素耐药性是一个新出现的全球健康问题。本研究的目的是评估鸡胴体分离株中的抗菌药物耐药性（AMR），并研究AMR分子机制以及毒力决定因素的存在情况。该研究对从突尼斯东北部屠宰场和零售店收集的257份样本进行。共分离出48株菌株，鉴定为肠炎沙门氏菌（n = 33）和鼠伤寒沙门氏菌（n = 15）。对8种抗生素进行了抗生素耐药性测试，观察到对四环素（100%）、红霉素（97.9%）、环丙沙星（73%）、萘啶酸（85.4%）、氨苄西林（83.3%）、阿莫西林/克拉维酸（22.9%）、氯霉素（75%）和庆大霉素（27.1%）的高耐药率。所有分离株均为多重耐药，共发现22种耐药模式。对所有分离株进行AMR基因（blaTEM、blaSHV、blaCTX-M、qnrA、qnrB、qnrS、aac(6’)-Ib-cr和tet(A)）筛查，以及gyrA基因（C257T替换）和parC基因（A2075G/A2074C）中的点突变筛查。检测到所有筛查的AMR基因以及C257T和A2075G突变。还确定了毒力基因型，所有分离株均携带运动性（flhDC）和侵袭性（invA）基因。大多数分离株还携带编码志贺毒素的stx1、stx2和eae基因。对参与格林-巴利综合征表达的gt1和gt2基因进行筛查，发现21.2%的肠炎沙门氏菌菌株中存在gt1基因，而它们均未携带gt2基因。我们的研究结果突出了同时携带多种毒力和AMR决定因素的肠炎沙门氏菌菌株的出现，这强调了多重耐药菌株通过食物链传播给人类的风险。因此，控制食源性病原体“从农场到餐桌”的传播以及限制畜牧业中抗菌药物的使用对于预防消费者风险和减轻多重耐药病原体的传播是必不可少的。
