Seroprevalences of Rickettsia conorii, Ehrlichia canis and Coxiella burnetii in Dogs from Montenegro

The first serological survey of C. Burnetii in domestic animals in Poland

BACKGROUND

• Q fever, known as coxiellosis in animals, represents a global zoonotic threat caused by the intracellular bacterium Coxiella burnetii (C. burnetii). The disease affects many animal species, including those considered significant reservoirs, such as cattle, sheep and goats. Transmission of the pathogen to other domestic animals, including companion animals, and then to humans has also been observed, highlighting the importance of understanding the epidemiology and prevalence of C. burnetii among companion animals. The present study aimed to determine the frequency of seroreagents for C. burnetii within pet dogs, cats and rabbits from urban Poland areas and identify possible risk factors for these animals.

RESULTS

• In total, serum samples from 491 dogs, 427 cats and 93 rabbits were used in the study. The seroprevalence of anti-C. burnetii antibodies in dogs and cats reached 0.61% (3/491; 95% CI: 0.21-1.78) and 0.23% (1/427; 95% CI: 0.04-1.31), respectively. No significant differences in seroprevalence across species and different subpopulations (age group, gender, exhibited symptoms, or sampling location) were found. All 93 samples from rabbits were negative for anti-C.burnetii antibodies.

CONCLUSIONS

• The seroprevalence rates of C. burnetii in dogs and cats were low; however, our results confirm that pet dogs and cats in Poland can be exposed to C. burnetii and may exhibit serological reactions. It has been reported that people who come into contact with secretions and excretions from the reproductive systems of dogs and cats (such as breeders, veterinarians, and veterinary clinic staff) may be at risk of contracting C. burnetii. Based on the findings, it is advised to be particularly cautious, especially when assisting with dogs and cats giving birth. Coxiellosis should be considered a potential cause of reproductive disorders in these animals. The results indicate that rabbits are probably less important in the circulation of the C. burnetii in the present study. This is the first serological survey of C. burnetii in pet dogs, cats and rabbits in Poland.

First Evidence of Rickettsia conorii Infection in Dogs in Northern Tunisia

A cross-sectional study was carried out, between April 2021 and June 2022, to understand the role of dogs in the circulation of rickettsiosis in Tunisia. The presence of specific IgG antibodies against Rickettsia conorii was analyzed by indirect immunofluorescence test. By qPCR, blood and ticks were collected from 136 dogs examined at the Canine Department of National School for Veterinary Medicine of Tunisia. These dogs were also analyzed to detect Rickettsia DNA. The rate of Rickettsia seropositivity in 136 dogs was 55.14%. A total of 51 (53%) seropositive dogs showed clinical and biological signs such as fever and anorexia as well as thrombocytopenia and anemia. By qPCR, targeting the mitochondrial 16S rRNA gene, no Rickettsia DNA was detected in the blood. On the other hand, qPCR followed by sequencing revealed the presence of R. conorii subsp. raoultii in 7 tick pools of the 51 pools composed of the 227 ticks collected. A One Health approach to raise the awareness of dog owners to control tick infestations is imperative, given the dangers of canine zoonoses.

Serological and molecular survey of Q fever in the dog population of the Campania region, southern Italy

Q fever is a re-emerging zoonosis whose epidemiological cycle in ruminants is well defined, while the role of other species (including pets) is still debated. In this study, the serological and molecular prevalence of Coxiella burnetii in a sample of dogs in the Campania region, southern Italy was evaluated. A seroprevalence of 5.97 % (16/268) was observed using a commercial multispecies ELISA, compared to only 2.7 % (5/197) at the molecular level. No risk factors correlated with higher levels of exposure except for the size of the animal (small dogs showed significantly higher seroprevalence). Positive samples were further evaluated for reactivity to phase I and II antigens using IFA and phase-specific ELISAs (for specific IgG detection). Two animals showed antibodies against both phases of infection, suggesting that Coxiella burnetii seroconversion in dogs follows similar dynamics to those observed in ruminants. One of the five samples that showed positive results in real-time PCR was confirmed at the PCR endpoint and showed similarity with other Coxiella spp. strains detected in tick and dog samples when sequenced. In this study, we demonstrated exposure to Coxiella burnetii for different categories of dogs in southern Italy, including pet dogs living indoors. Since reports of transmission of infection from pets to humans have been described in both rural and urban areas, careful surveillance of these species is also necessary. In the lack of additional information, comprehending the risk to humans requires monitoring of wild and domestic animal populations.

Serosurvey of Coxiella burnetii in Police Officers and Working Dogs in Brazil: Case Report and One Health Implications

BACKGROUND

Although the Coxiella burnetii infection has been investigated in dogs, its role in human transmission remains to be fully established, particularly in close and daily human-dog contact settings, such as in Police K-9 Units.

METHODS

Accordingly, this study aimed to assess anti-C. burnetii antibodies in clinically healthy police officers by an in-house indirect immunofluorescence assay (IFA), and working dogs by a commercial IFA Kit, from the State Special Operations Battalion, Paraná, Southern Brazil.

RESULTS

Overall, 1/18 (5.5%) police officers and 9/30 (30.0%; CI 95% 16.66-47.88) dogs tested seropositive to anti-C. burnetii IgG antibodies.

CONCLUSIONS

To date, this is the highest prevalence of Q fever seropositivity among military dogs worldwide. Despite the low sampling rate, a statistically significant association was found between seropositivity and female dogs (p = 0.0492). Further studies with larger sample sizes should be conducted to establish the prevalence of Q Fever in other Brazilian K-9 Units. In summary, this study is the first to conduct a concomitant serosurvey of police officers and working dogs, and its findings should be considered a warning for cross-exposure and transmission of Coxiella burnetii among Police K-9 Units in Brazil and worldwide.

Ixodid ticks and zoonotic tick-borne pathogens of the Western Balkans

Ixodid ticks are distributed across all countries of the Western Balkans, with a high diversity of species. Many of these species serve as vectors of pathogens of veterinary and medical importance. Given the scattered data from Western Balkan countries, we have conducted a comprehensive review of available literature, including some historical data, with the aim to compile information about all recorded tick species and associated zoonotic pathogens in this region. Based on the collected data, the tick fauna of the Western Balkans encompasses 32 tick species belonging to five genera: Ixodes, Haemaphysalis, Dermacentor, Rhipicephalus and Hyalomma. A range of pathogens responsible for human diseases has also been documented, including viruses, bacteria and parasites. In this review, we emphasize the necessity for integrated surveillance and reporting, urging authorities to foster research by providing financial support. Additionally, international and interdisciplinary collaborations should be encouraged that include the exchange of expertise, experiences and resources. The present collaborative effort can effectively address gaps in our knowledge of ticks and tick-borne diseases.

Ehrlichia canis and Rickettsia conorii Infections in Shelter Dogs: Seropositivity and Implications for Public Health

A cross-sectional study was conducted to gain insight into the epidemiology of canine ehrlichiosis and rickettsiosis in northern Portugal. Specific IgG antibodies to Ehrlichia canis were analysed using a commercial enzyme-linked immunosorbent assay (ELISA), and antibodies to Rickettsia conorii were analysed using a commercial indirect immunofluorescence antibody test (IFAT). A total of 113 dogs from two different shelters were sampled, and seroprevalence values of 0.9% (95% confidence (CI): 0.2-4.8%) for E. canis and 9.7 (95% CI: 5.5-16.6%) for R. conorii were found. Multiple logistic regression investigated risk factors for seropositivity. The odds ratios (ORs) of R. conorii seropositivity were higher for female dogs (OR = 6.429; 95% CI: 1.201-34.407). Dogs seropositive for co-infection (E. canis + R. conorii) were more frequently observed among females (OR = 7.606; CI 95%: 1.478-39.132) and in Shelter 2 (OR = 18.229; 95% CI: 2.190-151.756). These findings show that shelter dogs in northern Portugal are exposed to E. canis and R. conorii, which can affect both canines and humans. It is imperative to adopt a One Health approach to educate the public about the hazards of canine zoonoses and develop legislation and procedures to control their spread and preserve public health.

Development of a Large-Scale Pathogen Screening Test for the Biosafety Evaluation of Canine Mesenchymal Stem Cells

BACKGROUND

The action of mesenchymal stem cells (MSCs) is the subject of intense research in the field of regenerative medicine, including their potential use in companion animals, such as dogs. To ensure the safety of canine MSC batches for their application in regenerative medicine, a quality control test must be conducted in accordance with Good Manufacturing Practices (GMP). Based on guidance provided by the European Medicines Agency, this study aimed to develop and validate a highly sensitive and robust, nucleic acid-based test panel for the detection of various canine pathogens. Analytical sensitivity, specificity, amplification efficiency, and linearity were evaluated to ensure robust assessment. Additionally, viable spike-in controls were used to control for optimal nucleic acid extraction. The conventional PCR-based and real-time PCR-based pathogen assays were evaluated in a real-life setting, by direct testing MSC batches.

RESULTS

The established nucleic acid-based assays displayed remarkable sensitivity, detecting 100-1 copies/reaction of template DNA. They also exhibited high specificity and efficiency. Moreover, highly effective nucleic acid isolation was confirmed by the sensitive detection of spike-in controls. The detection capacity of our optimized and validated methods was determined by direct pathogen testing of nine MSC batches that displayed unusual phenotypes, such as reduced cell division or other deviating characteristics. Among these MCS batches of uncertain purity, only one tested negative for all pathogens. The direct testing of these samples yielded positive results for important canine pathogens, including tick-borne disease-associated species and viral members of the canine infectious respiratory disease complex (CIRDC). Notably, samples positive for the etiological agents responsible for enteritis (CPV), leptospirosis (Leptospira interrogans), and neosporosis (Neospora caninum) were also identified. Furthermore, we conducted biosafety evaluation of 12 MSC batches intended for therapeutic application. Eleven MSC batches were found to be free of extraneous agents, and only one tested positive for a specific pathogen, namely, canine parvovirus.

CONCLUSION

In this study, we established and validated reliable, highly sensitive, and accurate nucleic acid-based testing methods for a broad spectrum of canine pathogens.

First report on tick-borne pathogens detected in ticks infesting stray dogs near butcher shops

Public health is a major concern for several developing countries due to infectious agents transmitted by hematophagous arthropods such as ticks. Health risks due to infectious agents transmitted by ticks infesting butcher-associated stray dogs (BASDs) in urban and peri-urban regions have been neglected in several developing countries. To the best of the authors' knowledge, this is the first study assessing public health risks due to ticks infesting BASDs in Pakistan's urban and peri-urban areas. A total of 575 ticks (390 from symptomatic and 183 from asymptomatic BASDs) were collected from 117 BASDs (63 symptomatic and 54 asymptomatic); the ticks belonged to 4 hard tick species. A subset of each tick species' extracted DNA was subjected to polymerase chain reaction (PCR) to amplify the 16S rDNA and cox1 sequences of the reported tick species, as well as bacterial and protozoal agents. The ticks' 16S rDNA and cox1 sequences showed 99-100% identities, and they were clustered with the sequence of corresponding species from Pakistan and other countries in phylogenetic trees. Among the screened 271 ticks' DNA samples, Anaplasma spp. was detected in 54/271 (19.92%) samples, followed by Ehrlichia spp. (n = 40/271, 14.76%), Rickettsia spp. (n = 33/271, 12.17%), Coxiella spp. (n = 23/271, 4.48%), and Hepatozoon canis (n = 9/271, 3.32%). The obtained sequences and phylogenetic analyzes revealed that the pathogens detected in ticks were Ehrlichia minasensis, Ehrlichia sp., Hepatozoon canis, Coxiella burnetii, Coxiella sp., Anaplasma capra, Anaplasma platys, Anaplasma sp., Rickettsia massiliae, "Candidatus Rickettsia shennongii" and Rickettsia aeschlimannii. Tick-borne pathogens such as E. minasensis, H. canis, A. capra, A. platys, and R. aeschlimannii, were detected based on the DNA for the first time in Pakistan. This is the first report on public health risks due to ticks infesting BASDs. These results not only provided insights into the occurrence of novel tick-borne pathogens in the region but also revealed initial evidence of zoonotic threats to both public health and domestic life.

Coxiella burnetii in Dogs and Cats from Portugal: Serological and Molecular Analysis

Dogs and cats are potential sources of infection for some zoonotic diseases such as Q fever, caused by Coxiella burnetii, a multiple host pathogen. Q fever outbreaks in dogs and cats have been related with parturition and abortion events, and ticks have a potential role in the transmission of this pathogen. This study aimed to screen for C. burnetii in dogs and cats, and in ticks collected from infested animals. An observational descriptive study was conducted in Portugal at two time points nine years apart, 2012 and 2021. Sera obtained from dogs and cats (total n = 294) were tested for C. burnetii antibodies using a commercial ELISA adapted for multi-species detection. C. burnetii DNA was screened by qPCR assay targeting IS1111 in uterine samples and in ticks. A decrease in the exposure to C. burnetii was observed in cats from 17.2% (95% CI: 5.8−35.8%) in 2012 to 0.0% in 2021, and in dogs from 12.6% (95% CI: 7.7−19.0%) in 2012 to 1.7% (95% CI: 0.3−9.1%) in 2021 (p < 0.05). Overall, and despite differences in the samples, rural habitat seems to favour the exposure to C. burnetii. The DNA of C. burnetii was not detected in ticks. The low seropositivity observed in 2021 and the absence of C. burnetii DNA in the tested samples, suggest that dogs and cats from Portugal are not often exposed to the pathogen. Nevertheless, the monitoring of C. burnetii infection in companion animals is an important tool to prevent human outbreaks, considering the zoonotic potential for owners and veterinarians contacting infected animals, mainly dogs and cats from rural areas which often come into contact with livestock.

Ticks, Fleas, and Harboured Pathogens from Dogs and Cats in Cyprus

Ticks and fleas are blood-sucking ectoparasites that cause irritation and anaemia to their hosts and act as vectors of pathogens (vector-borne pathogens, VBPs) of relevance for animal and human health. In the present study, tick and flea species in dogs and cats from Cyprus were recorded and VBPs were detected in the collected specimens. Ectoparasites were collected from 220 animals (161 dogs and 59 cats), and a questionnaire including demographic, clinical, and other information was filled out for each animal. The ectoparasites were morphologically identified and the detection of VBPs was performed by PCR-coupled sequencing. Rhipicephalus sanguineus sensu lato was found on 108 dogs and 13 cats, and Ixodes gibbosus on 2 dogs. Ctenocephalides felis was the predominant flea species (on 62 dogs and 45 cats), while one dog and one cat were infested by Ctenocephalides canis and Echidnophaga gallinacea, respectively. The VBPs in ticks were Anaplasma platys, Rickettsia massiliae, Rickettsia conorii, Rickettsia felis, Hepatozoon felis and Hepatozoon canis, while Rickettsia felis, Rickettsia sp., Bartonella koehlerae, Bartonella clarridgeiae, and Bartonella henselae were recorded in fleas. Statistical analysis (chi-square test and multiple univariate generalized linear model) showed that animals up to 6 months of age were less likely to be infested with ticks than older animals, but more likely to be infested with fleas. Ticks were more prevalent in sheltered than in owned animals, while the odds ratio of flea presence was higher in owned animals than those living in shelters. The present study is the first investigation on the occurrence of ticks and fleas in dogs and cats from Cyprus, showing the presence of different VBPs in these important ectoparasites. The results point out the importance of systematic ectoparasite control in dogs and cats.

Canine and Feline Parasitology: Analogies, Differences, and Relevance for Human Health

Cats and dogs are treated as family members by most pet owners. Therefore, a high quality of veterinary care and preventive medicine is imperative for animal health and welfare and for the protection of humans from zoonotic pathogens. There is a general perception of cats being treated as "small dogs," especially in the field of clinical parasitology. As a result, several important differences between the two animal species are not taken into proper consideration and are often overlooked. Dogs and cats are profoundly different under evolutionary, biological, ethological, behavioral, and immunological standpoints. These differences impact clinical features, diagnosis, and control of canine and feline parasites and transmission risk for humans. This review outlines the most common parasitoses and vector-borne diseases of dogs and cats, with a focus on major convergences and divergences, and discusses parasites that have (i) evolved based on different preys for dogs and cats, (ii) adapted due to different immunological or behavioral animal profiles, and (iii) developed more similarities than differences in canine and feline infections and associated diseases. Differences, similarities, and peculiarities of canine and feline parasitology are herein reviewed in three macrosections: (i) carnivorism, vegetarianism, anatomy, genetics, and parasites, (ii) evolutionary adaptation of nematodes, including veterinary reconsideration and zoonotic importance, and (iii) behavior and immune system driving ectoparasites and transmitted diseases. Emphasis is given to provide further steps toward a more accurate evaluation of canine and feline parasitology in a changing world in terms of public health relevance and One Health approach.

Seroprevalence of Anaplasma spp. and Ehrlichia spp. and molecular detection of Anaplasma phagocytophilum and Anaplasma platys in stray dogs in Bosnia and Herzegovina

Stray dogs may be highly exposed to vector-borne pathogens (VBPs), including zoonotic agents, and therefore may pose a high risk of spreading infections to other animals and humans. Among the Anaplasmataceae, Anaplasma phagocytophilum, A. platys and Ehrlichia canis are commonly identified species in dogs in Europe; however, information on the occurrence of these pathogens in canine populations from Bosnia and Herzegovina (B&H) is still lacking. Thus, the aim of this study was to determine the seroprevalence of Anaplasma spp. and Ehrlichia spp. in stray dogs in the Sarajevo region of B&H and to identify A. phagocytophilum, A. platys, E. canis and E. ewingii by molecular techniques. A total of 903 blood samples of stray dogs were screened by SNAP 4Dx Plus Test for the presence of antibodies against A. phagocytophilum/A. platys and E. canis/E. ewingii. Real-time PCR assays were performed for the detection of Anaplasmataceae, A. phagocytophilum, A. platys, E. canis and E. ewingii in seropositive dogs. Antibodies to A. phagocytophilum/A. platys and/or E. canis/E. ewingii were detected in 187 (20.7%) samples. Seroprevalence was highest for A. phagocytophilum/A. platys (184/903, 20.4%). Two dogs had antibodies to E. canis/E. ewingii, while one dog was found to have antibodies to A. phagocytophilum/A. platys and to E. canis/E. ewingii. Forty-eight (25.7%) of the 187 seropositive dogs examined by Real-time PCR were positive for Anaplasmataceae. A. phagocytophilum was detected in 45 (24%) samples, while one sample was positive for A. phagocytophilum and A. platys. Two samples positive for Anaplasmataceae tested negative in the species-specific PCRs. E. canis or E. ewingii could not be detected in any of the Ehrlichia-seropositive dogs. These findings highlight the need for dog health monitoring, improving the health and welfare of stray dog population, and establishment of effective surveillance systems to combat VBDs.