ABSTRACT
Red foxes (Vulpes vulpes) are found throughout the United Kingdom (UK), and can reach high population densities in urban areas. They are often infested with ticks which may carry tick-borne pathogens, leading to a risk of transmission to domestic animals and humans. This study investigated the prevalence of tick-borne pathogens in ticks sourced from red fox carcasses across Great Britain between 2018 and 2022. Tick species were identified using morphological keys and molecular barcoding, followed by specific pathogen testing using PCR. In total, 227 ticks were collected from 93 foxes. Pooling (n = 2) was undertaken for unengorged nymphs from the same tick species and fox host, with 203 homogenates tested in total (24 pools and 179 individual ticks). Ixodes hexagonus was the most abundant tick species sampled (73 %), of which 59 % were nymphs and 41 % were females. Less common were Ixodes ricinus (12 %) and Ixodes canisuga (15 %), the majority of which were females (73 % and 91 %, respectively). One Ixodes sp. larva was identified. Babesia DNA was identified in seven individual ticks and once in pooled ticks (n = 2); seven detections were in I. hexagonus and one in I. canisuga, with an overall detection rate of 7 % (95 % CI: 6 - 8 %). Sequence analysis confirmed that all Babesia detections in I. hexagonus were Babesia vulpes, with detection of Babesia Badger Type A in I. canisuga. Screening for Anaplasma phagocytophilum DNA through amplification of the msp2 gene yielded an overall detection rate of 4 % (detected in I. hexagonus only). Louping ill virus was not detected by qRT-PCR in any tick RNA tested. The majority of pathogen detections were in ticks from red foxes in rural areas of the UK, although a small number of Babesia detections were in ticks collected from semi-rural or urban red foxes. Additionally, B. vulpes was detected in GB red fox tissues, suggesting a potential role as a reservoir host. This study confirms the detection of tick-borne pathogens in ticks infesting UK red foxes and highlights the involvement of GB tick species in animal or human disease transmission.
ABSTRACT
Rhythmic theta frequency (~5-12 Hz) oscillations coordinate neuronal synchrony and higher frequency oscillations across the cortex. Spatial navigation and context-dependent episodic memories are represented in several interconnected regions including the hippocampal and entorhinal cortices, but the cellular mechanisms for their dynamic coupling remain to be defined. Using monosynaptically-restricted retrograde viral tracing in mice, we identified a subcortical GABAergic input from the medial septum that terminated in the entorhinal cortex, with collaterals innervating the dorsal presubiculum. Extracellularly recording and labeling GABAergic entorhinal-projecting neurons in awake behaving mice show that these subcortical neurons, named orchid cells, fire in long rhythmic bursts during immobility and locomotion. Orchid cells discharge near the peak of hippocampal and entorhinal theta oscillations, couple to entorhinal gamma oscillations, and target subpopulations of extra-hippocampal GABAergic interneurons. Thus, orchid cells are a specialized source of rhythmic subcortical GABAergic modulation of 'upstream' and 'downstream' cortico-cortical circuits involved in mnemonic functions.