Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt.
Department of Microbiology, Faculty of Veterinary Medicine, Alexandria University, Egypt.
Int J Food Microbiol. 2021 Aug 2;351:109268. doi: 10.1016/j.ijfoodmicro.2021.109268. Epub 2021 Jun 1.
The increase in multidrug-resistant Salmonella enterica and its spread from food to humans are considered a serious public health concern worldwide. Little is currently known about the prevalence of extended-spectrum β-lactamase (ESBL)-producing S. enterica in fish in Africa. Therefore, this study aimed to investigate the existence of ESBL-producing S. enterica in retail fish in Egypt. In total, 200 fish samples were collected randomly from various retail fish markets in Egypt. S. enterica were detected in 19 (9.5%; 95% CI: 5.8-14.4) of the fish samples analyzed. Of the 19 non-repetitive S. enterica isolates, 18 were serologically categorized into eight S. enterica serovars and a non-typable serovar. All 19 S. enterica isolates (100%) showed multidrug-resistant phenotypes to at least three classes of antimicrobials, and 11 (57.9%) exhibited an ESBL-resistant phenotype and harbored at least one ESBL-encoding gene. The ESBL-producing S. enterica serovars were as follows: Kentucky (3 isolates; 15.8%), Enteritidis (2 isolates; 10.5%), Typhimurium (2 isolates; 10.5%), and 1 isolate (5.3%) each of Infantis, Virchow, Paratyphi B, and Senftenberg. The identified β-lactamase-encoding genes included ESBL-encoding genes bla, bla, bla, bla, bla and bla; the AmpC β-lactamase-encoding gene bla; and the narrow-spectrum β-lactamase-encoding genes bla and bla. All S. enterica isolates were negative for carbapenemase-encoding genes. Molecular analysis of plasmid transferability and replicon typing revealed that most plasmids (with β-lactamase-encoding genes) were transferrable, and the most common incompatibility groups were IncI1, IncA/C, IncHI1, and IncN. To the best of our knowledge, this is the first report for molecular characterization of ESBL-producing S. enterica in fish in Egypt. The occurrence of ESBL-producing S. enterica in retail fish constitutes a potential public health threat with the possibility of transmission of these strains with resistance genes to humans. Such transmission would exacerbate the resistance to an important class of antibiotics commonly used in hospitals to treat typhoid and non-typhoidal Salmonella infections.
食源性多重耐药沙门氏菌的增加及其在全球范围内从食物传播到人类，被认为是一个严重的公共卫生问题。目前，人们对非洲鱼类中产超广谱β-内酰胺酶（ESBL）的沙门氏菌的流行情况知之甚少。因此，本研究旨在调查埃及零售鱼类中是否存在产 ESBL 的沙门氏菌。总共从埃及各地的零售鱼市场随机采集了 200 个鱼样本。在分析的 19 个非重复的沙门氏菌分离株中，有 19 个（9.5%；95%置信区间：5.8-14.4）在鱼样本中被检测到。19 个非重复的沙门氏菌分离株中有 18 个通过血清学分类为 8 个沙门氏菌血清型和一个不可分型血清型。所有 19 个沙门氏菌分离株（100%）对至少三类抗菌药物表现出多药耐药表型，11 个（57.9%）表现出 ESBL 耐药表型并携带至少一种 ESBL 编码基因。产 ESBL 的沙门氏菌血清型如下：肯塔基州（3 个分离株；15.8%）、肠炎沙门氏菌（2 个分离株；10.5%）、都柏林沙门氏菌（2 个分离株；10.5%）和婴儿沙门氏菌、沃氏沙门氏菌、乙型副伤寒沙门氏菌和森夫滕贝格沙门氏菌各 1 个分离株（5.3%）。鉴定出的β-内酰胺酶编码基因包括 ESBL 编码基因 bla、bla、bla、bla、bla 和 bla；AmpC β-内酰胺酶编码基因 bla；以及窄谱β-内酰胺酶编码基因 bla 和 bla。所有沙门氏菌分离株均为碳青霉烯酶编码基因阴性。质粒可转移性和复制子分型的分子分析表明，大多数质粒（带有β-内酰胺酶编码基因）是可转移的，最常见的不相容群是 IncI1、IncA/C、IncHI1 和 IncN。据我们所知，这是首次报道在埃及鱼类中对产 ESBL 的沙门氏菌进行分子特征描述。零售鱼类中产 ESBL 的沙门氏菌的存在对公共健康构成了潜在威胁，这些携带耐药基因的菌株有可能传播给人类。这种传播会加剧对医院常用的治疗伤寒和非伤寒沙门氏菌感染的一类重要抗生素的耐药性。
