The bacterial community associated with the leechMyzobdella lugubrisLeidy 1851 (Hirudinea: Piscicolidae) from Lake Erie, Michigan, USA

Abstract

Summary:Leeches are widespread in the Great Lakes Basin, yet their potential to harbor disease-causing agents has not been investigated. The purpose of this study was to identify the bacterial community of the commonly occurring leech, Myzobdella lugubris, within the Lake Erie Watershed. Leech samples were collected from the pectoral fins of channel catfish, Ictalurus punctatus, and freshwater drum, Aplodinotus grunniens, from Lake Erie in commercial trap nets and pooled into two samples based on host attachment. Bacteria from within the viscera of M. lugubris were identified by sequencing their 16S rRNA (rDNA) gene of amplified community bacterial DNA extracted from pooled leech homogenate samples and were checked for similarity in two public databases: the Ribosomal Database Project and BLAST. Bacteria belonging to the phylum Bacteroidetes, β-proteobacteria, Verrucomicrobia, and unclassified Bacteria were present in the leech samples. A large number of bacteria found within leeches attached to channel catfish consisted of sequences that could not be classified beyond the Domain Bacteria. However, many of these sequences were homologous (< 45 %) to the phylum Bacteroidetes. One of the five genera detected in the leech homogenates was Flavobacterium psychrophilum, a serious fish pathogen that causes Bacterial Cold Water Disease. While the occurrence of genera varies, bacteria associated with the two fish species were similar.The bacTerial communiTy associaTed wiTh The leech Myzobdella lugubris leidy 1851 (hirudinea: Piscicolidae) from lake erie, michigan, usa

High prevalence of buccal ulcerations in largemouth bass,Micropterus salmoides(Centrarchidae) from Michigan inland lakes associated withMyzobdella lugubrisLeidy 1851 (Annelida: Hirudinea)

“…The tissue damage caused by this leech compromises the integrity of bass buccal mucosa and allows for potential invasion by pathogenic bacteria and viruses. In this context, recent studies from the authors’ laboratory have demonstrated that M. lugubris carries the Viral Hemorrhagic Septicemia Virus (Faisal & Schulz, 2009), a disease that has devastated important fish stocks in the Laurentian Great Lakes; and Flavobacterium psychrophilum , the causative agent of both Bacterial Coldwater Disease and Rainbow Trout Fry Syndrome, which can cause high mortalities in salmonids (Schulz & Faisal, 2010). Other species of leeches are well known for functioning as vehicles for transmission of infectious agents in fish (Dombrowski, 1952; Ahne, 1985; Cusack & Cone, 1986; Kruse et al ., 1989; Jones & Woo, 1992; Zintl et al ., 2000; Kikuchi et al ., 2002; Hemmingsen et al ., 2005; Kikuchi & Fukatsu, 2005).…”

Feeding duration of Myzobdella lugubris leech on largemouth bass (Micropterus salmoides)

“…al, 1975). M. lugubris attachment points may become superficially infected (Faisal et al., 2011; Noga et al., 1990; Pomposini et al., 2019) and can facilitate pathogen entry, potentially including viral haemorrhagic septicaemia virus (VHSV) in the Laurentian Great Lakes (Faisal & Schulz, 2009; Schulz & Faisal, 2010; Schulz et al., 2011). In the oral cavity, detachment of M. lugubris results in circular mucosal depressions (MD).…”

Hirudo verbana is a source of fungal isolates potentially pathogenic to humans

“…Leeches feeding on the blood of numerous aquatic animals such as fishes, amphibians, water birds and mammals (including humans) are a source of pathogens for successive hosts. Additionally various microorganisms living in the natural water reservoir can colonize the leeches (Eroglu et al, 2001;Schulz and Faisal, 2010). More than 650 species of leech have been identified, but only 15 of them are used medically and are classified as medicinal leeches.…”