Epidemiological study of hemotropic mycoplasmas (hemoplasmas) in cats from central Spain

Feline leishmaniasis in an animal shelter in northeastern Brazil: Clinical aspects, coinfections, molecular detection, and serological study of a new recombinant protein

Infection and clinical cases of leishmaniasis caused by Leishmania infantum in cats have been increasingly reported in several countries, including Brazil. In this study, we used an enzyme-linked immunosorbent assay (ELISA) and an immunochromatographic test (ICT) based on a recombinant antigen (rKDDR-plus) to detect anti-Leishmania antibodies in cats from an animal shelter in northeastern Brazil. We compared the results with an ELISA using L. infantum crude antigen (ELISA-CA). We also investigated the presence of Leishmania DNA in blood or ocular conjunctival samples as well as the association between Leishmania PCR positivity and serological positivity to feline immunodeficiency virus (FIV), feline leukemia virus (FeLV) and Toxoplasma gondii. Concerning serological assays, a higher positivity was detected using the ICT-rKDDR-plus (7.5%; 7/93) as compared to ELISA-rKDDR-plus (5.4%; 5/93) and ELISA-CA (4.3%; 4/93). Upon PCR testing, 52.7% (49/93) of the ocular conjunctival swabs and 48.3% (44/91) of the blood samples were positive. Together, PCR and serological testing revealed overall positivities of 73.1% (68/93) and 12.9% (12/93), respectively. Among PCR-positive samples, 45.5% (31/68) showed co-infection with FIV, 17.6% (12/68) with FeLV, and 82.3% (56/68) with T. gondii. More than half of the PCR-positive cats showed at least one clinical sign suggestive of leishmaniasis (58.8%; 40/68) and dermatological signs were the most frequent ones (45.5%; 31/68). Both tests employing the recombinant antigen rKDDR-plus (i.e., ICT-rKDDR-plus and ELISA-rKDDR-plus) detected more positive cats than the ELISA-CA but presented low overall accuracy. PCR testing using either blood or ocular conjunctival samples detected much more positive cats than serological tests.

A case of mistaken identity: a systematic review, meta-analysis, and reinvestigation of hemotropic Mycoplasma spp. infection in Ctenocephalides felis (cat flea)

BACKGROUND

Feline-associated hemotropic Mycoplasma (hemoplasmas) are believed to be transmitted by two primary mechanisms: (1) direct transmission via fighting and (2) vector-borne transmission by the cat flea (Ctenocephalides felis). While the efficiency of transmission by C. felis appears low, most manuscripts focus on the prevalence of hemoplasmas in wild-caught fleas and report either a very low (< 3%) or a high (> 26%) prevalence. Therefore, we aimed to assess the influence of sample processing and PCR methods on C. felis hemoplasma infection prevalence.

METHODS

A systemic review of PubMed articles identified 13 manuscripts (1,531 fleas/flea pools) that met the inclusion criteria (performed PCR for >1 hemoplasma on C. felis collected from cats). Risk of bias was assessed utilizing the ROBINS-E tool. Meta-analysis performed in R of these manuscripts found that not washing samples and a common set of 16S rRNA primers first published in Jensen et al. 2001 were associated with increased hemoplasma prevalence. To evaluate the influence of washing on newly collected fleas, we assessed the hemoplasma status of 20 pools of 5 C. felis each, half of which were washed and half not washed.

RESULTS

Flea washing did not influence the detection of hemoplasma but instead amplified Spiroplasma. To assess non-specific amplification with the Jensen et al. 2001 primers, 67 C. felis samples (34% previously reported hemoplasma infected) were subject to PCR and sequencing. By this method, hemoplasma was detected in only 3% of samples. In the remaining "hemoplasma infected" fleas, PCR amplified Spiroplasma or other bacteria.

CONCLUSIONS

Therefore, we concluded that hemoplasma infection in C. felis is rare, and future flea prevalence studies should sequence all positive amplicons to validate PCR specificity. Further investigation of alternative methods of feline-associated hemoplasma transmission and the ability of C. felis to maintain hemoplasma infection is necessary.

Molecular survey on vector-borne pathogens in clinically healthy stray cats in Zaragoza (Spain)

BACKGROUND

In Europe, feline vector-borne infections are gaining importance because of the changing climate, expanding habitats of potential vectors and expanding pathogen reservoirs. The main objective of this study was to assess the prevalence of vector-borne pathogens (VBPs) in stray cats in Zaragoza, Spain, and to investigate potential risk factors for infection, including feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV).

METHODS

Blood samples from stray cats presented to the veterinary faculty in Zaragoza between February 2020 and 2022 were tested by polymerase chain reaction (PCR) for the presence of Anaplasma phagocytophilum, Anaplasma platys, Bartonella henselae, Ehrlichia canis, Rickettsia spp., haemotropic Mycoplasma spp., Hepatozoon spp., Leishmania infantum, piroplasms and microfilariae at the LABOKLIN laboratory. The cats were also tested for FeLV and FIV by PCR.

RESULTS

Nearly half of the cats (158/332, 47.6%) were positive for at least one VBP. Hepatozoon spp. were detected in 25.6%, haemotropic Mycoplasma spp. in 22.9%, B. henselae in 9.3% and L. infantum in 2.1% of the cats. Male sex had a statistically significant association with test results for haemotropic Mycoplasma spp. (odds ratio 1.38 [1.21;1.57]); regionality with Hepatozoon spp., B. henseale and FIV; and seasonality with Hepatozoon spp., haemotropic Mycoplasma spp., L. infantum and FeLV (P ≤ 0.05 each). A strong positive correlation was reported for the amount of rainfall and the number of cats that tested positive for Hepatozoon spp. (ρ = 753, P = 0.05). None of the cats tested positive for A. phagocytophilum, A. platys, E. canis, Rickettsia spp., piroplasms, or microfilariae. Co-infections with multiple VBPs were detected in 56 out of 332 cats (16.9%). Thirty-one of the 332 cats included in the study (9.3%) tested positive for FeLV (6.9%) and for FIV (3.6%). In 20/31 cats (64.5%) that tested positive for FeLV/FIV, coinfections with VBP were detected (P = 0.048, OR 2.15 [0.99; 4.64]).

CONCLUSIONS

VBPs were frequently detected in stray cats in Zaragoza. In particular, regionality and seasonality had a statistically significant association with PCR results for most VBPs included in the study.

Companion Vector-Borne Pathogens and Associated Risk Factors in Apparently Healthy Pet Animals (Dogs and Cats) in Khukhot City Municipality, Pathum Thani Province, Thailand

Pet animals (dogs and cats) can be infected with several companion vector-borne pathogens (CVBPs). Morbidity and mortality have been reported in pet animals due to CVBP infections. Pet animals living in close proximity to humans are able to transmit zoonotic pathogens. This study used molecular techniques to investigate the prevalence of CVBPs in apparently healthy pet animals (dogs and cats) from Khukhot City Municipality, Pathum Thani province, Thailand. In total, 210 blood samples were randomly collected from 95 dogs and 115 cats for the detection of seven companion vector-borne pathogens (Anaplasma, Babesia, Bartonella, Ehrlichia, Hepatozoon, Mycoplasma, and Rickettsia) using polymerase chain reaction. The results showed that 10.5% (22/210) of apparently healthy pet animals were infected with at least one pathogen, comprising 6 dogs (6.3% of all dogs tested) and 16 cats (13.9% of all cats tested). Ehrlichia (6.3%) was present only in dogs; furthermore, 1.1% of the dogs were positive for Anaplasma. There was one dog case co-infected with two pathogens (1.1%). In cats, Mycoplasma (9.6%) was the predominant CVBP, followed by Rickettsia (4.4%). The DNA sequences of all positive animals were 97–99% homologous to those found in the GenBank™ database for all CVBPs identified, namely Ehrlichia canis, Anaplasma platys, Rickettsia felis, Mycoplasma haemofelis, and Candidatus Mycoplasma haemominutum. Additionally, the risk of infection with CVBPs in pets was significantly associated with age, with young dogs more likely to be infected with CVBPs than adult dogs (OR 8.5, 95% CI 1.4–50.1, p = 0.006), while adult cats were more likely to be infected with CVBPs than young cats (OR 3.8, 95% CI 1.0–14.0, p = 0.038). The detection of CVBPs demonstrated the potential risk of infection that may occur in apparently healthy pet animals in Pathum Thani province. These results confirmed that apparently healthy pet animals may still be at risk of vector-borne infections and could maintain the infection cycle in pet populations. Furthermore, sampling a greater number of apparently healthy pet animals may disclose predictors of CVBP positivity in domesticated animals in this area.

Molecular detection of feline hemoplasmas and retroviruses in free-roaming and shelter cats within a university campus

Objectives

The aim of the present study was to assess the frequency of hemoplasma, feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) infections in cats living in an on-campus shelter and free-roaming cats within a university campus in Brazil.

Methods

Blood samples were tested using quantitative PCR for hemoplasma, FIV and FeLV. Positive hemoplasma samples were sequenced. Associations between hemoplasma detection and living situation, sex, flea and/or tick parasitism, and coinfection with FIV and FeLV, were assessed using Fisher's exact test and the respective odds ratios were calculated.

Results

Overall, 6/45 (13.3%) cats tested positive: four (8.9%) were infected with 'Candidatus Mycoplasma haemominutum' and two (4.4%) with Mycoplasma haemofelis. All positive samples were from free-roaming cats (6/15; 40.0%) and had statistically significantly lower packed cell volumes (P = 0.037). Although 5/23 (21.7%) males and 1/22 (4.6%) females were positive, no statistically significant association between sex and hemoplasma infection was found (P = 0.19). Viral quantitative PCR (qPCR) was performed on 43/45 samples, among which 2/43 (4.7%) were positive for FIV and none for FeLV. Only one cat (2.3%) was coinfected with hemoplasma and FIV (P = 0.26). In addition, 4/6 (66.7%) cats that tested positive for hemoplasmas were infested by fleas (P = 0.0014) and/or ticks (P = 0.25).

Conclusions and relevance

These results show that even if the free-roaming cat population is clinically healthy and has adequate access to food, it may present flea infestation and hemoplasma infection with lower packed cell volume values.

Occurrence and bacterial loads of Bartonella and haemotropic Mycoplasma species in privately owned cats and dogs and their fleas from East and Southeast Asia

Bartonella spp. and haemoplasmas are pathogens of veterinary and medical interest with ectoparasites mainly involved in their transmission. This study aimed at molecular detection of Bartonella spp. and haemoplasmas in cats (n = 93) and dogs (n = 96), and their related fleas (n = 189) from countries in East and Southeast Asia. Ctenocephalides felis was the dominant flea species infesting both cats (97.85%) and dogs (75%) followed by Ctenocephalides orientis in dogs (18.75%) and rarely in cats (5.2%). Bartonella spp. DNA was only detected in blood samples of flea‐infested cats (21.51%) (p < .0001, OR = 27.70) with Bartonella henselae more frequently detected than Bartonella clarridgeiae in cat hosts (15.05%, 6.45%) and their associated fleas (17.24%, 13.79%). Out of three Bartonella‐positive fleas from dogs, two Ct. orientis fleas carried Bartonella vinsonii subsp. berkhoffii and Bartonella clarridgeiae, while the 3rd flea (Ct. felis) carried Candidatus Bartonella merieuxii. Felines represented a risk factor for Bartonella spp. infections, where fleas collected from cats (32.25%) presented an increased likelihood for Bartonella spp. occurrence (p < .0001, OR = 14.76) than those from dogs (3.13%). Moreover, when analysing infectious status, higher Bartonella spp. DNA loads were detected in fleas from bacteraemic cats compared to those from non‐bacteraemic ones (p < .05). The haemoplasma occurrence was 16.13% (15/93) and 4.17% (4/96) in cat and dog blood samples from different countries (i.e. Indonesia, Malaysia, the Philippines, Taiwan and Thailand), with cats more at risk of infection (p < .01, OR = 5.96) than dogs. Unlike Bartonella spp., there was no evidence for flea involvement in the hemoplasmas' transmission cycle, thus supporting the hypothesis of non‐vectorial transmission for these pathogens. In conclusion, client‐owned cats and dogs living in East and Southeast Asia countries are exposed to vector‐borne pathogens with fleas from cats playing a key role in Bartonella spp. transmission, thus posing a high risk of infection for humans sharing the same environment.

Prospective serological and molecular cross-sectional study focusing on Bartonella and other blood-borne organisms in cats from Catalonia (Spain)

Background

There is limited clinical or epidemiological knowledge regarding Bartonella infection in cats, and no serological studies have compared the presence of antibodies against different Bartonella species. Moreover, there are limited feline Bartonella studies investigating co-infections with other vector-borne pathogens and the associated risk factors. Therefore, the objective of this study was to investigate Bartonella spp. infections and co-infections with other pathogens in cats from Barcelona (Spain) based on serological and/or molecular techniques and to determine associated risk factors.

Methods

We studied colony and owned cats (n = 135). Sera were tested for Bartonella henselae-, Bartonella quintana-, and Bartonella koehlerae-specific antibodies using endpoint in-house immunofluorescence antibody assays. Bartonella real-time PCR (qPCR) and conventional PCR (cPCR) were performed. In addition, cPCR followed by DNA sequencing was performed for other pathogenic organisms (Anaplasma, Babesia, Cytauxzoon, Ehrlichia, Hepatozoon, hemotropic Mycoplasma, and Theileria spp.).

Results

From 135 cats studied, 80.7% were seroreactive against at least one Bartonella species. Bartonella quintana, B. koehlerae, and B. henselae seroreactivity was 67.4, 77.0, and 80.7%, respectively. Substantial to almost perfect serological agreement was found between the three Bartonella species. Colony cats were more likely to be Bartonella spp.-seroreactive than owned cats. Moreover, cats aged ≤ 2 years were more likely to be Bartonella spp.-seroreactive. Bartonella spp. DNA was detected in the blood of 11.9% (n = 16) of cats. Cats were infected with B. henselae (n = 12), B. clarridgeiae (n = 3), and B. koehlerae (n = 1). Mycoplasma spp. DNA was amplified from 14% (n = 19) of cat blood specimens. Cats were infected with Mycoplasma haemofelis (n = 8), Candidatus M. haemominutum (n = 6), Candidatus Mycoplasma turicensis (n = 4), and Mycoplasma wenyonii (n = 1). Anaplasma, Babesia, Cytauxzoon, Ehrlichia spp., Hepatozoon, and Theileria spp. DNA was not amplified from any blood sample. Of the 16 Bartonella spp.-infected cats based on PCR results, six (37%) were co-infected with Mycoplasma spp.

Conclusions

Bartonella spp. and hemoplasma infections are prevalent in cats from the Barcelona area, whereas infection with Anaplasma spp., Babesia, Cytauxzoon, Ehrlichia spp., Hepatozoon, and Theileria infections were not detected. Co-infection with hemotropic Mycoplasma appears to be common in Bartonella-infected cats. To our knowledge, this study is the first to document M. wenyonii is infection in cats.

Graphical Abstract

Hemotropic Mycoplasma and Bartonella Species Diversity in Free-Roaming Canine and Feline from Luanda, Angola

Free-roaming dogs and cats represent potential reservoirs for zoonotic vector-borne pathogens shedding to the human population. Given the health impact of these pathogens, we searched free-roaming dogs and cats included in an animal population control program from Luanda, Angola, for Bartonella and hemotropic mycoplasma infection. We report the detection of Bartonella henselae (2/66; 3%), Candidatus Mycoplasma haemominutum (5/66; 7.5%) and Mycoplasma haemofelis (1/66; 1.5%) in cats. One dog was found positive for Mycoplasma haemocanis (1/20; 5%). This is the first report of Bartonella henselae infections in stray cats and of hemotropic mycoplasmas in cats and dogs from Angola. Despite the relatively small sample size, our results sustain the hypothesis of uncontrolled circulation of these agents in highly mobile synanthropic animal populations of Luanda. Population and vector control could contribute to reducing the likelihood for animal-to-animal and animal-to-human transmission.

Prevalence of hemotropic mycoplasmas and coinfection with feline leukemia virus and feline immunodeficiency virus in cats in the Moscow region, Russia

Feline haemoplasma infection studies are lacking in Russia. This retrospective study was conducted to estimate the prevalence of feline haemoplasmas in domestic cats in the Moscow region, Russia. A risk of haemoplasma coinfection with feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) was also determined. qPCR analysis for feline haemoplasmas was performed on EDTA blood samples from 753 cats from the Moscow region, Russia. Subsets of these samples were tested also for FIV and FeLV by qPCR. Of the 753 blood samples, 104 (13.8 %) were positive for one of the Mycoplasma species. The prevalence of 'Candidatus Mycoplasma haemominutum' (CMhm), Mycoplasma haemofelis (Mhf), and 'Candidatus Mycoplasma turicensis' (CMt) was 7.6 %, 5.5 %, and 0.7 %, respectively. One sample (0.1 %) was simultaneously infected with two haemoplasmas, namely, Mhf and CMt. Haemoplasma positive cats were more likely to be infected with FIV than haemoplasma negative (17.6 % vs 6.7 %), but these differences were not statistically significant. The prevalence of FeLV was comparable among haemoplasma positive and negative cats (23.5 % vs 25.7 %) All three known species of feline haemoplasma were detected, confirming their presence in Russia. The overall and species-specific rates of haemoplasma infections in Russian cats are generally similar to the rates in the countries of central Europe. This report documents for the first time the prevalence of feline hemotropic mycoplasmas in domestic cats not only in Russia but also in eastern Europe.

Evaluation of hematological alteration of vector-borne pathogens in cats from Bangkok, Thailand

Background

Cats can be carriers of infected arthropods and be infected with several vector-borne pathogens (VBPs) but there is limited knowledge about their pathogenic role in cats. This study aimed to assess the prevalence of some feline vector-borne agents by molecular technique and to characterize the hematological findings associated with these infections in a cat population from Bangkok Thailand.

Results

PCR was positive with at least one pathogen in 237 out of 372 subjects (63.7%), with prevalence of 39.5% (147/372) for Babesia spp., 36.9% (137/372) for hemoplasmas and 3.2% (12/372) for Hepatozoon spp. The cats older than 1 year were at significantly greater risk for VBPs infection (P = 0.001; OR = 1.43; 95% CI: 1.12 – 1.81) and hemoplasmas infection (χ2 = 10.8, df = 1; P < 0.0001; OR = 2.45; 95% CI: 1.49 – 4.01). A significant association between hematological findings and hemoplasma infection were identified in the present study. Besides, VBPs infection revealed more frequent in male cats (χ2= 6.38, df = 1, P = 0.01). Macrocytic hypochromic type of anemia was observed in cats infested with blood-sucking arthropods compared to the non-infested cats presented.

Conclusions

The current study confirmed that Babesia, Hepatozoon and hemoplasmas had infected semi-domesticated cats in Bangkok, Thailand, with Babesia and hemoplasmas being dominant in prevalence. Some hematological findings were significantly associated with cats infected with vector-borne pathogens in this study including leukocyte count and platelets count that may help support veterinary technicians in diagnosis and appropriate treatment. Campaigns of VBPs monitoring in Bangkok emphasizing on the investigation of vectors and possible routes of the infection in animals should be conducted to prevent the transmission of the pathogens.

Molecular detection of hemotropic mycoplasmas (hemoplasmas) in domestic cats (Felis catus) in Romania

BACKGROUND

The hemotropic mycoplasmas (hemoplasmas) of the genus Mycoplasma are recognized as important bacteria that parasitize red blood cells, causing hemolytic anemia in many mammalian species, including cats. No information is available concerning the presence of feline hemoplasma infections in cats in Romania. Thus, the objective of the present study was to provide data on the occurrence and molecular characterization of hemotropic mycoplasmas in client-owned cats in Romania.

METHODS

Blood samples from 51 unhealthy cats, originating from Timişoara Municipality, Romania, were screened for the presence of hemoplasmas using conventional polymerase chain reaction (PCR) targeting the 16S rRNA gene and sequencing assays. PCR-positive samples were subsequently analyzed by phylogenetic and population genetic analysis.

RESULTS

Molecular analysis revealed 11 (21.6%) positive samples, consisting of 8 (72.7%) Candidatus Mycoplasma haemominutum and 3 (27.3%) Mycoplasma haemofelis confirmed positives. Candidatus Mycoplasma turicensis was not detected, and no co-infections were registered. No significant associations (p > 0.05) were found between the hemoplasma infection status and age, gender, breed, presence of ectoparasites, feline leukemia virus/feline immunodeficiency virus positivity of cats, or the sampling season. However, outdoor access was positively associated (p = 0.049) with infection and could be considered a risk factor (OR = 4.1) in acquiring feline hemotropic mycoplasmas. Phylogenetic analysis revealed that our sequences clustered with those selected from the GenBank database in two distinct clades. The registered population genetic indices were strongly supportive of the great variance in sequences between the recorded Mycoplasma species.

CONCLUSIONS

The findings support the occurrence of feline hemoplasma infections in previously uninvestigated territories of Europe, providing useful information for small animal practitioners. To our knowledge, the present survey is the first reported molecular evidence of feline hemoplasma infections in Romania.

Role of vector-borne pathogens in the development of fever in cats: 1. Flea-associated diseases

PRACTICAL RELEVANCE

There has been increasing identification of vector-borne pathogens in cats presented to veterinary clinics around the world for evaluation of fever and the associated secondary effects, such as signs of depression and loss of appetite.

AIM

The aim of this article is to summarize the clinically relevant information concerning fever in cats that is associated with pathogens known or suspected to be vectored by fleas, with an emphasis on presenting clinical abnormalities and optimal diagnostic, treatment and prevention strategies. Fever in cats that is associated with pathogens vectored by ticks or sandflies is discussed in Part 2 of this article series.

Genetic characterization and risk factors for feline hemoplasma infection in semi-domesticated cats in Bangkok, Thailand

Background and Aim:

Stray cats are a reservoir for various zoonotic diseases relevant to public health in Thailand. The vector-borne infection, hemoplasmosis, also known as infectious anemia, is one such disease carried by domestic and wild felids. This study focuses on molecular characterization and phylogenetic analysis of hemoplasma in semi-domesticated cats in Bangkok, Thailand.

Materials and Methods:

In total, 473 blood samples were collected from 53 temple communities in 34 metropolitan districts and assayed using polymerase chain reaction (PCR) to amplify partial 16S rRNA genes for hemoplasma detection. Risk factors for hemoplasma infection (gender, age, free-roaming, and ectoparasite exposure) were analyzed using Chi-square tests, logistic regression, and odds ratios (OR) with 95% confidence intervals (95% CI) using R software (version 3.6.1). A phylogenetic tree was established from genetic characterization of hemoplasmas.

Results:

In total, 180 samples (38.05%) were positive for hemoplasma. Of half of the positive sequenced samples, 83.33% were infected with Candidatus Mycoplasma haemominutum (CMhm), 13.33% with Mycoplasma haemofelis (Mhf), and 3.33% with Candidatus Mycoplasma turicensis (CMt). Cats over 5 years old were more likely to be infected than younger cats (p<0.005, OR=3.8, 95% CI=1.64-4.78). Cats were diagnosed as positive based on PCR assays in 97% (33/34) of districts surveyed. The phylogenetic tree showed two majority clusters with three clades of feline hemotropic mycoplasma.

Conclusions:

Overall, the survey shows the prevalence (38.05%) and distribution of feline hemoplasma in semi-domesticated cats. This information will contribute to effective prevention and control strategies to minimize infections by feline vector-borne pathogens in Thailand.

Detection of Flea-Borne Pathogens from Cats and Fleas in a Maltese Shelter

In a sanctuary located on the island of Malta, 23 clinically healthy cats randomly selected were sampled for blood and fleas. Only fleas were collected from 35 cats. All fleas were identified as Ctenocephalides felis, except for one specimen of Ctenocephalides canis. To the best of the authors' knowledge, this may be the first time to establish the occurrence of Bartonella koehlerae and B. clarridgeiae, as well as of Candidatus Mycoplasma haemominutum in the blood samples of 11 cats (47.82% [95% CI: 29.33-67.04]) with conventional PCR assays. One or more pathogens were found in 54 (96.42% [95% CI: 86.74-99.70]) out of 56 pooled flea samples, the most prevalent was Rickettsia felis. The DNA of Bartonella henselae, the commonest etiological agent of cat scratch disease, was detected first time in a pooled flea sample of a cat.