Species composition and host preference of fleas (Insecta: Siphonaptera) on rodent and domestic animals in Tamil Nadu, India

The species composition and host preference of medically important fleas monitored in urban, semi-urban, and rural revealed 412(65%) and 222(35%) fleas. From urban and rural habitats 90 and 345 fleas were collected respectively. There was a significant difference between urban and rural habitats in flea abundance. From rodents and domestic animals 209 (33%) Xenopsylla cheopis, 203 (32%) X. astia and 222 (35%) Ctenocephalides felis fleas were recorded. Fleas were predominantly found on Rattus rattus 45(83.3%) and Canis familiaris 31(83.8%). Among the habitats, there was no significant difference in rodent flea positivity and dog/cat flea positivity.

Insecticidal Efficacy of Medicines During Cat Flea Infestations in Tyumen

From time immemorial people began to domesticate wild animals and throughout many generations, they are kept by people genetically isolated from external pathogens. In the prevailing era, every pet owner is trying to breed and protect his animal from contagious and noncontagious diseases. Having said that, lack and inadequacy of knowledge and mass media on simple preventive measures results in the widespread occurrence of infectious and invasive diseases, including flea, Ctenocephalides felis infestation among dogs as well as cats. The present paper primarily attempts to present the results of therapeutic efficiency of Komfortis, Foresto, and Fitoelita medical agents used during flea infestation among domestic cats. In order to meet the purpose of the study, research was carried out within the framework of study and analysis of the epizootic state of invasive diseases of agricultural and unproductive animals, bees, and birds. Studies of changes in the species composition, and bioecological patterns of the development cycle of parasites under shifting boundaries of their ranges were also done. For the study, the animals were divided into three groups of 10 animals each. Standard clinical and hematological research methods were used during the study. Blood sampling included three stages: before insecticide treatment, the intermediate interval of 15 days, and the final stage. Based on the results obtained, it was found that Komfortis and Foresto have 100% therapeutic efficacy at all stages of flea development and possess a long-lasting action duringa flea infestation. The morphological blood analysisshowed that the proposed medical agents have no toxic orsideeffects.

Melting curve analysis to differentiate Rickettsia spp. and Rickettsia felis

Rickettsiosis, caused by Rickettsia species, is one of the old arthropod-borne illness that commonly found in humans and animals. One of the barriers to rickettsiosis control is the intricacy and time-consuming nature of rickettsiosis laboratory diagnosis. This study aimed to establish quantitative real-time PCR targeting the gltA gene for the DNA differentiation of Rickettsia spp. and Ricketsia felis. The collection of cat flea was extracted to acquire the DNA of Rickettsia. Primers were designed based on the analysis of Rickettsia gltA gene sequences. The confirmation of R. felis was performed by sequencing of PCR product. BLAST analysis was done to confirm the closest similarity of the sequences. Results of this study highlighted the melting temperature was reached at 78,5 °C for Rickettsia spp. and 76.5+0.5 °C for Rickettsia felis. The melting peak temperatures were significantly different between Rickettsia spp. and R. felis (p<0.05). The findings of this work are crucial in the development of powerful diagnostic procedures for detecting and distinguishing Rickettsia spp. and R. felis species.

Arthropod Ectoparasites Have Potential to Bind SARS-CoV-2 via ACE

Coronavirus-like organisms have been previously identified in Arthropod ectoparasites (such as ticks and unfed cat flea). Yet, the question regarding the possible role of these arthropods as SARS-CoV-2 passive/biological transmission vectors is still poorly explored. In this study, we performed in silico structural and binding energy calculations to assess the risks associated with possible ectoparasite transmission. We found sufficient similarity between ectoparasite ACE and human ACE2 protein sequences to build good quality 3D-models of the SARS-CoV-2 Spike:ACE complex to assess the impacts of ectoparasite mutations on complex stability. For several species (e.g., water flea, deer tick, body louse), our analyses showed no significant destabilisation of the SARS-CoV-2 Spike:ACE complex, suggesting these species would bind the viral Spike protein. Our structural analyses also provide structural rationale for interactions between the viral Spike and the ectoparasite ACE proteins. Although we do not have experimental evidence of infection in these ectoparasites, the predicted stability of the complex suggests this is possible, raising concerns of a possible role in passive transmission of the virus to their human hosts.

What Is in a Cat Scratch? Growth of Bartonella henselae in a Biofilm

Bartonella henselae (B. henselae) is a gram-negative bacterium that causes cat scratch disease, bacteremia, and endocarditis, as well as other clinical presentations. B. henselae has been shown to form a biofilm in vitro that likely plays a role in the establishment and persistence of the bacterium in the host. Biofilms are also known to form in the cat flea vector; hence, the ability of this bacterium to form a biofilm has broad biological significance. The release of B. henselae from a biofilm niche appears to be important in disease persistence and relapse in the vertebrate host but also in transmission by the cat flea vector. It has been shown that the BadA adhesin of B. henselae is critical for adherence and biofilm formation. Thus, the upregulation of badA is important in initiating biofilm formation, and down-regulation is important in the release of the bacterium from the biofilm. We summarize the current knowledge of biofilm formation in Bartonella species and the role of BadA in biofilm formation. We discuss the evidence that defines possible mechanisms for the regulation of the genes required for biofilm formation. We further describe the regulation of those genes in the conditions that mimic both the arthropod vector and the mammalian host for B. henselae. The treatment for persistent B. henselae infection remains a challenge; hence, a better understanding of the mechanisms by which this bacterium persists in its host is critical to inform future efforts to develop drugs to treat such infections.

Dynamic gene expression in salivary glands of the cat flea during Rickettsia felis infection

ABSTRACT The cat flea, Ctenocephalides felis, is an arthropod vector capable of transmitting several human pathogens including Rickettsia species. Earlier studies identified Rickettsia felis in the salivary glands of the cat flea and transmission of rickettsiae during arthropod feeding. The saliva of hematophagous insects contains multiple biomolecules with anticlotting, vasodilatory and immunomodulatory activities. Notably, the exact role of salivary factors in the molecular interaction between flea-borne rickettsiae and their insect host is still largely unknown. To determine if R. felis modulates gene expression in the cat flea salivary glands, cat fleas were infected with R. felis and transcription patterns of selected salivary gland-derived factors, including antimicrobial peptides and flea-specific antigens, were assessed. Salivary glands were microdissected from infected and control cat fleas at different time points after exposure and total RNA was extracted and subjected to reverse-transcriptase quantitative PCR for gene expression analysis. During the experimental 10-day feeding period, a dynamic change in gene expression of immunity-related transcripts and salivary antigens between the two experimental groups was detected. The data indicated that defensin-2 (Cf-726), glycine-rich antimicrobial peptide (Cf-83), salivary antigens (Cf-169 and Cf-65) and deorphanized peptide (Cf-75) are flea-derived factors responsive to rickettsial infection.

Risk of SARS-CoV-2 Transmission from Humans to Pets and Vice Versa

Numerous studies have described human-to-human airborne and contact-based transmissions of SARS-CoV-2, the epidemiological agent of coronavirus disease 2019 (COVID-19). In this review article, we assess the COVID-19 reverse-zoonotic transmission from humans-to-household pets and zoonotic transmission from pets-to-humans, and animal-to-animal transmission between cohoused pets including cats, dogs, and ferrets. COVID-19 in mink, ducks, pigs, chickens, and ectoparasite of domestic pets such as cat flea are also discussed. Cats and ferrets were found highly susceptible to SARS-COV-2; dogs susceptible to a lower degree; and chickens, pigs, and ducks not susceptible. Reverse zoonotic SARS-COV-2 transmission in dogs and cats was found as confirmed by genetic analysis of virus strains isolated from pets and pet owners. Most studies show absence of clinical symptoms in infected dogs and cats. There is no evidence of zoonotic transmission of SARS-COV-2 from pets, although the possibility could not be ruled out. COVID-19 in mink farms showed both human-to-mink and subsequent mink-to-human (zoonotic) transmission raising concerns about mink becoming possible unexpected intermediate hosts of SARS-COV-2. Preventative and control measures limiting zoonotic and reverse zoonotic COVID-19 transmissions should be developed and enforced publicly to minimize virus spread. Our article is important for animal and pet management in COVID-19 pandemic. As there is no evidence of SARS-CoV-2 transmission from household pets to humans, the pets must not be abandoned. To avoid virus transmission from infected households and pet-to-pet, the pets must be quarantined and isolated similar to humans. Leaving pets roaming in the community will increase the chances of virus spread. The original source of the virus is still unknown therefore, pets and animal management is necessary to stop the current and future pandemic.