Characterization of multi-resistant Shigella species isolated from raw cow milk and milk products

Rasha Elkenany; Rasha Eltaysh; Mona Elsayed; Mohamed Abdel-Daim; Radwa Shata

doi:10.1292/jvms.22-0018

Characterization of multi-resistant Shigella species isolated from raw cow milk and milk products

J Vet Med Sci. 2022 Jul 1;84(7):890-897. doi: 10.1292/jvms.22-0018. Epub 2022 May 6.

Authors

Rasha Elkenany¹, Rasha Eltaysh², Mona Elsayed³, Mohamed Abdel-Daim^{4

5}, Radwa Shata⁶

Affiliations

¹ Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
² Department of Pharmacology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
³ Department of Hygiene and Zoonoses, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
⁴ Department of Pharmaceutical Sciences, Pharmacy Program, Batterjee Medical College, Jeddah, Saudi Arabia.
⁵ Pharmacology Department, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, Egypt.
⁶ Department of Food Hygiene and Control, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.

Abstract

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_TEM, bla_CTX-M, bla_OXA-1 and bla_SHV), 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_TEM in all isolates and bla_CTX-M 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_OXA-1 and bla_SHV. All Shigella extended spectrum β-lactamases (ESBL) producers (12, 100%) were positive for the bla_TEM, bla_CTX-M, 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_TEM and bla_CTX-M) 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.

Keywords: Shigella species; antibiotic resistance; dairy product; qacE∆1 gene; β-lactamase encoding gene.

MeSH terms

Animals
Anti-Bacterial Agents / pharmacology
Cattle
Disinfectants
Egypt
Female
Microbial Sensitivity Tests / veterinary
Milk* / microbiology
Shigella* / drug effects
Shigella* / genetics
beta-Lactamases / genetics

Substances

Anti-Bacterial Agents
Disinfectants
beta-Lactamases