Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
Department of Pharmacology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
J Vet Med Sci. 2022 Jul 1;84(7):890-897. doi: 10.1292/jvms.22-0018. Epub 2022 May 6.
This study was organized to investigate the prevalence, antibiotic and disinfectant resistance phenotypes and genotypes as well as plasmid profiles of Shigella species isolated from raw cow milk and milk products in Egypt. Genotypic analysis was performed to determine the presence of β-lactamase encoding genes (bla, bla, bla and bla), tet(A) and qacE∆. Forty-two (7%) Shigella isolates (S. dysenteriae, S. flexneri, and S. sonnei) were recovered, with S. dysenteriae as the predominant type. Antibiotic sensitivity tests showed that 71.4% of Shigella isolates were resistant to three or more antibiotic classes (multidrug-resistant). High resistance rates were observed against tetracyclines (100%), ampicillin, amoxicillin-clavulanate (90.5%, each) and cefaclor (66.7%), while no resistance was detected against imipenem, sulfamethoxazole/trimethoprim, and azithromycin. Disinfectant susceptibility test of Shigella isolates revealed resistance to phenolic compound (vanillic acid), while 85.7% of the Shigella isolates were resistant to benzalkonium chloride. Uniplex PCR analysis declared the existence of β-lactamase encoding genes (bla in all isolates and bla in 28.6% of isolates) and, tet(A) in all isolates and 85.7% of the isolates were positive for qacE∆1, while all isolates were negative for bla and bla. All Shigella extended spectrum β-lactamases (ESBL) producers (12, 100%) were positive for the bla, bla, and qacE∆1 genes. Furthermore, plasmid profiling revealed seven distinct plasmid patterns (P1-P7), ranging from 1.26 to 33.61 kb, among all the Shigella strains; S. dysenteriae exhibited the greatest variance. The co-transfer of β-lactamase genes (bla and bla) and qacE∆1 genes was observed by conjugation from all ESBL producers to a recipient strain. These findings indicate the emergence of Shigella species in Egypt that exhibited multi-resistance to either antibiotics (particularly ESBL producer strains) or disinfectants. Thus, the resistance of Shigella species should regularly be monitored and appropriate measures should be taken to manage this problem.
本研究旨在调查埃及生牛乳和乳制品中分离的志贺菌属的流行率、抗生素和消毒剂耐药表型和基因型以及质粒图谱。进行基因分析以确定是否存在β-内酰胺酶编码基因（bla、bla、bla 和 bla）、tet(A)和 qacEΔ1。共分离出 42 株（7%）志贺菌属（志贺痢疾杆菌、志贺福氏菌和志贺索氏菌），其中志贺痢疾杆菌为主要类型。抗生素敏感性试验显示，71.4%的志贺菌属分离株对三种或三种以上抗生素类别（多药耐药）具有耐药性。对四环素（100%）、氨苄西林、阿莫西林-克拉维酸（90.5%，各）和头孢克洛（66.7%）的耐药率较高，而对亚胺培南、磺胺甲恶唑/甲氧苄啶和阿奇霉素没有耐药性。志贺菌属分离株的消毒剂敏感性试验显示对酚类化合物（香草酸）有耐药性，而 85.7%的志贺菌属分离株对苯扎氯铵有耐药性。单重 PCR 分析显示所有分离株均存在β-内酰胺酶编码基因（bla 在所有分离株中，bla 在 28.6%的分离株中）和 tet(A)，85.7%的分离株对 qacEΔ1 呈阳性，而所有分离株均对 bla 和 bla 呈阴性。所有产超广谱β-内酰胺酶（ESBL）的志贺菌属（12 株，100%）均对 bla、bla 和 qacEΔ1 基因呈阳性。此外，质粒图谱显示，在所有志贺菌菌株中存在 7 种不同的质粒图谱（P1-P7），大小为 1.26-33.61kb；志贺痢疾杆菌表现出最大的差异。通过接合，所有 ESBL 产生菌都将β-内酰胺酶基因（bla 和 bla）和 qacEΔ1 基因转移到受体菌株中。这些发现表明，埃及出现了对抗生素（特别是 ESBL 产生菌）或消毒剂具有多药耐药性的志贺菌属。因此，应定期监测志贺菌属的耐药性，并采取适当措施来管理这一问题。
