Bites by the noble false widow spider Steatoda nobilis can induce Latrodectus-like symptoms and vector-borne bacterial infections with implications for public health: a case series

Abstract

Context: In recent years, the Noble false widow spider Steatoda nobilis (Thorell, 1875) has expanded its range globally and may represent a potential threat to native ecosystems and public health. Increasing numbers in synanthropic habitats have led to more human encounters and envenomations. Steatoda nobilis bites were previously classed as medically significant with similarities to bites from true black widows of the genus Latrodectus but deemed milder in onset, with symptoms generally ranging from mild to moderate. Case details: In this manuscript we present 16 new cases of S. nobilis envenomations bringing the total number of confirmed cases reported in the literature to 24. We report new symptoms and provide discussion on the contributing factors to pathology following bites by S. nobilis. Discussion: We report a range of pathologies including necrosis, Latrodectus-like envenomation symptoms that include debilitating pain, tremors, fatigue, nausea, hypotension, and vectored bacterial infections including cellulitis and dermatitis. Symptoms ranged from mild to severe, requiring hospitalisation in some cases.

Webslinger vs. Dark Knight: First record of a false widow spider Steatoda nobilis preying on a pipistrelle bat in Britain

“…The noble false widow spider Steatoda nobilis originates from the Macaronesian archipelagos and has recently colonized parts of Europe, including Ireland and Great Britain (Bauer et al, 2019; Dugon et al, 2017; Dunbar, Schulte, et al, 2018; Hambler, 2019; Snazell & Jones, 1993), Western Asia (Türkeş & Mergen, 2007; Zamani et al, 2015), North America (Vetter et al, 2015; Vetter & Rust, 2012), and South America (Bauer et al, 2019; Faúndez et al, 2018; Faúndez et al, 2020; Faúndez & Téllez, 2016; Porras‐Villamil et al, 2020; Taucare‐Ríos et al, 2016). The species is notable for its potential medical importance (Dunbar, Afoullouss, et al, 2018; Dunbar et al, 2021; Dunbar, Khan, et al, 2020; Warrell et al, 1991). Additionally, its venom shares many characteristics with the venom of true black widows of the genus Latrodectus , such as the highly potent α‐latrotoxin that can affect the nervous system of vertebrates (Dunbar, Fort, et al, 2020), and allows them to immobilize and feed on small vertebrates (Dunbar, Ennis, et al, 2018).…”

Bacterial Adaptation to Venom in Snakes and Arachnida

“…Likewise, E. faecalis isolates were the most common aerobic Gram-positive isolates in N. naja oral swabs (n = 6) (45). Postenvenomation cellulitis and dermatitis, presumed bacterial in nature, were additionally observed in 25% of a 16-case series of Steatoda nobilis (false widow spider) envenomations in the United Kingdom and Ireland: one of these required intravenous penicillin and flucloxacillin treatment after hospital admission (46). S. nobilis chelicerae were previously found to harbor 11 bacterial taxa and 22 separate bacterial species, including class 2 pathogens; 3 of these 22 species showed multidrug resistance (47).…”

Comment on Dunbar et al. (2022) “Webslinger vs. Dark Knight: First record of a false widow spider Steatoda nobilis preying on a pipistrelle bat in Britain”

“…Some Latrodectus spiders have been reported to catch and consume mice (Nyffeler and Vetter, 2018). In conclusion, the specific silk properties together with the specific behavioural strategies combined with the potent venom found in the Latrodectus and Steatoda species studied thus far (Dunbar et al, 2022b;Garb and Hayashi, 2013) render it likely that these spiders do prey on vertebrates, including capture, killing, and consumption at least occasionally. Nevertheless, the flightless newborn bat neither walked under nor flew into the web and killing was not documented, nor were bite marks, envenomation, or eating reported.…”