Bartonella henselaeandRickettsia felisDetected in Cat Fleas (Ctenocephalides felis) Derived from Eastern Austrian Cats

Advancements in understanding the molecular and immune mechanisms of Bartonella pathogenicity

Bartonellae are considered to be emerging opportunistic pathogens. The bacteria are transmitted by blood-sucking arthropods, and their hosts are a wide range of mammals including humans. After a protective barrier breach in mammals, Bartonella colonizes endothelial cells (ECs), enters the bloodstream, and infects erythrocytes. Current research primarily focuses on investigating the interaction between Bartonella and ECs and erythrocytes, with recent attention also paid to immune-related aspects. Various molecules related to Bartonella's pathogenicity have been identified. The present review aims to provide a comprehensive overview of the newly described molecular and immune responses associated with Bartonella's pathogenicity.

Current Data on Rickettsia felis Occurrence in Vectors, Human and Animal Hosts in Europe: A Scoping Review

Rickettsia felis is an emerging pathogen with increasing reports of human cases and detection in arthropod and animal host species worldwide. In this scoping review we record the newest data reported for R. felis in Europe: the vector and host species found to be infected, and the geographical distribution and prevalence of R. felis infection in vectors and hosts. A total of 15 European countries reported the occurrence of R. felis in hosts and vectors during 2017−2022. The vectors found to be infected by R. felis were flea, tick and mite species; Ctenocephalides felis and Ixodes ricinus were the dominant ones. The hosts found to be infected and/or exposed to R. felis were humans, cats and small mammals. Physicians should be aware of the epidemiology and include illness caused by R. felis in the differential diagnosis of febrile disease. Veterinarians should keep training pet owners on the need for effective year-round arthropod control on their pets, especially for fleas.

Molecular Survey of Bartonella Species in Stray Cats and Dogs, Humans, and Questing Ticks from Portugal

Bartonella spp. comprises emergent and re-emergent fastidious Gram-negative bacteria with worldwide distribution. Cats are the main reservoir hosts for Bartonella henselae and dogs represent opportunistic hosts for the bacteria. Even though ticks may also play a role in transmission, their competence as vectors for Bartonella spp. has not been totally understood. Considering only a few studies had a focus on screening Bartonella in animals, humans and ectoparasites in Portugal, this study aimed to address the molecular occurrence of Bartonella sp. in 123 stray cats, 25 stray dogs, 30 humans from Lisbon and 236 questing ticks within the country. Using a qPCR targeting the nuoG gene, it was possible to detect Bartonella sp. DNA on 20.32% of cat samples (25/123). From these positive samples, 13 sequences were characterized as B. henselae, 11 as B. clarridgeiae and 1 presented co-infection with both species. The absolute quantification of nuoGBartonella DNA in sampled cats ranged from 2.78 × 10 to 1.03 × 10⁵ copies/µL. The sampled dogs, humans and ticks were negative. These results showed that B. henselae and B. clarridgeiae are circulating in stray cats from Lisbon. Additional and more extended studies should be conducted to determine the impact of such infections on humans, particularly those in constant and direct contact with cats.

Fleas (Siphonaptera) of domestic and wild animals in extreme northeastern Algeria: first inventory, hosts, and medical and veterinary importance

Fleas are an important member of the North African entomofauna. An understanding of the risks of flea-borne diseases to public and veterinary health can be gained with surveys of their abundance, distribution, and hosts. The aims of this study were to make an initial assessment of flea (Siphonaptera) species collected from a selected number of mammalian hosts in Algeria and debate their medical and veterinary importance. To do so, an entomological survey was conducted on several animal species (goats, dogs, cats, rabbits, hedgehogs, and mongooses) in six localities of El Tarf region located in extreme northeastern Algeria. During the survey, flea specimens were collected from hosts, stored in alcohol, and identified using a taxonomic key. More than 1,200 specimens were collected and identified; including four species: Ctenocephalides felis, Ctenocephalides canis, Pulex irritans, and Archaeopsylla erinacei (s.l.). Goats and dogs were the most infested animals, followed by cats and hedgehogs. Ctenocephalides felis was the most prevalent flea among all infested animals, with 631 collected specimens, followed by Pulex irritans with 433 samples. Overall, this study is an initial assessment of flea species recovered from selected common mammals in northeastern Algeria.

Bartonella Infections in Cats and Cat Fleas in Lithuania

Bartonella are vector-borne parasitic bacteria that cause zoonotic infections in humans. One of the most common infections is cat-scratch disease caused by Bartonella henselae and Bartonella clarridgeiae. Cats are the major reservoir for these two species of bacteria, while cat fleas are vectors for the transmission of infection agents among cats. The aim of the present study was to investigate the presence of Bartonella infections in stray and pet cats and in cat fleas in Lithuania. Blood samples were taken from 163 cats presented in pet clinics and animal shelters. A total of 102 fleas representing two species, Ctenocephalides felis and Ctenocephalides canis, were collected from 12 owned cats that live both outdoors and indoors. Bartonella DNA in samples was detected using a nested PCR targeting the 16S–23S rRNA intergenic spacer (ITS) region. Bartonella DNA was detected in 4.9% (8/163) of the cats and 29.4% (30/102) of the fleas. Sequence analysis of the ITS region showed that the cats and fleas were infected with B. henselae, B. clarridgeiae and Bartonella sp., closely related to B. schoenbuchensis. This study is the first report on the prevalence and molecular characterization of Bartonella spp. in cats and cat fleas in Lithuania.

Flea-borne pathogens in the cat flea Ctenocephalides felis and their association with mtDNA diversity of the flea host

Flea-borne pathogens were screened from 100 individual cat fleas using a PCR approach, of which 38 % were infected with at least one bacterium. Overall, 28 % of the flea samples were positive for Bartonella as inferred from ITS DNA region. Of these, 25 % (7/28) were identified as Bartonella clarridgeiae, 42.9 % (12/28) as Bartonella henselae consisted of two different strains, and 32.1 % (9/28) as Bartonella koehlerae, which was detected for the first time in Malaysia. Sequencing of gltA amplicons detected Rickettsia DNA in 14 % of cat flea samples, all of them identified as Rickettsia asembonensis (100 %). None of the flea samples were positive for Mycoplasma DNA in 16S rRNA gene detection. Four fleas were co-infected with Bartonella and Rickettsia DNAs. Statistical analyses reveal no significant association between bacterial infection and mtDNA diversity of the cat flea. Nevertheless, in all types of pathogen infections, infected populations demonstrated lower nucleotide and haplotype diversities compared to uninfected populations. Moreover, lower haplotype numbers were observed in infected populations.