The first case of detection of Listeria monocytogenes sequence types ST7, ST20, ST425 in wastewater during an investigation of water bodies in the Vologda region

Abstract

Introduction. Listeria monocytogenes is an important human pathogen causing various forms of listeriosis, including foodborne infections, meningitis, neonatal sepsis, and abortion. Listeria are common all over the world. The purpose of the study was to conduct microbiological monitoring of L. monocytogenes in water reservoirs near livestock premises in the Vologda district of the Vologda region. Materials and methods. Bacterial cultures were isolated using two methods, titration and filtration, followed by analysis using methods of conventional bacteriology, serotyping, and species identification by instrumental procedures such as whole genome sequencing, and bioinformatic analysis. Results. Three isolates of L. monocytogenes and one isolate of Listeria innocua were isolated from 12 analyzed water samples (wastewater 6, river water 4, and storm water 2 samples). whole genome sequencing of three L. monocytogenes strains attributed them to the evolutionary line II, and to three sequence types and two serogroups ST425(1/2a-3a), ST20(1/2a-3a), ST7 (4a-4c). The strains are shown to belong to multiple drug resistant ones conferring resistance to three functional groups of antibacterials such as tetracyclines, macrolides, and sulfonamides. Antibiotic resistance genes (fox, psp-like, lin,norB,sul), virulence Islands LIPI-1 and LIPI-2, and virulence genes inlABCJ, oatA, ami, gtcA, vip, and lisK in genomes of the strain were identified. Stress tolerance Island SSI-1 was identified in one strain. Conclusions. The data obtained indicate contamination of water sources near the livestock premises with L. monocytogenes strains possessing high pathogenic potentiality for outbreaks of listeriosis in humans. This shows the necessity of careful monitoring of water sources for the presence of the causative agent of listeriosis as well as the implementing of anti-epidemic measures.

Keywords

• listeria monocytogenes
• monitoring
• genetic lines
• sequence types
• virulence genes
• stress tolerance genes