Attempted transmission of Candidatus Mycoplasma haemominutum and Mycoplasma haemofelis by feeding cats infected Ctenocephalides felis

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.

Prevalence and Diversity of Haemotropic Mycoplasma Species in Cats and Their Ectoparasites (Fleas and Ticks)

Mycoplasma spp. pathogens frequently cause chronic and acute diseases in cats. The aim of the present study was to investigate the presence and genetic diversity of Mycoplasma spp. in cats and their ectoparasites using PCR and sequence analysis of the 16S rRNA gene. Blood samples were collected from 541 domestic and stray cats in Lithuania. Ectoparasites (153 fleas and 321 ticks) were collected from owned domestic cats that live both outdoors and indoors. Mycoplasma spp. were detected in 7.2% of cat blood samples and 4.4% of Ctenocephalides felis fleas. The sequence analysis revealed the presence of Mycoplasma haemofelis in 1.1% of cats and 'Candidatus Mycoplasma haematominutum' in 4.8% of cats. Ct. felis fleas harboured M. haemofelis. To the best of the authors' knowledge, this is the first report on the prevalence and molecular characterisation of Mycoplasma bacteria in cats in Lithuania and cat fleas in the Baltic States.

The association of host and vector characteristics with Ctenocephalides felis pathogen and endosymbiont infection

Surveillance of the fleas and flea-borne pathogens infecting cats is important for both human and animal health. Multiple zoonotic Bartonella and Rickettsia species are known to infect the most common flea infesting cats and dogs worldwide: Ctenocephalides felis, the cat flea. The ability of other flea species to transmit pathogens is relatively unexplored. We aimed to determine cat host and flea factors independently associated with flea Bartonella and Rickettsia infection. We also assessed flea and cat infection by flea-host pair and location. To accomplish these aims, we performed qPCR for the detection of Bartonella, hemotropic Mycoplasma, Rickettsia, and Wolbachia DNA using paired cat and flea samples obtained from free-roaming cats presenting for spay or neuter across four locations in the United States. A logistic regression model was employed to identify the effect of cat (sex, body weight, geographic location, and Bartonella, hemotropic Mycoplasma, and Rickettsia spp., infection) and flea (clade and Rickettsia and Wolbachia infection) factors on C. felis Bartonella clarridgeiae infection. From 189 free roaming cats, we collected 84 fleas: Ctenocephalides felis (78/84), Cediopsylla simplex (4/84), Orchopeas howardi (1/84), and Nosopsyllus fasciatus (1/84). Ctenocephalides felis were phylogenetically assigned to Clades 1, 4, and 6 by cox1 gene amplification. Rickettsia asembonensis (52/84) and B. clarridgeiae (16/84) were the most common pathogenic bacteria detected in fleas. Our model identified host cat sex and weight as independently associated with B. clarridgeiae infection in fleas. Rickettsia asembonensis (52/84), Rickettsia felis (7/84) and Bartonella henselae (7/84) were detected in specific clades: R. felis was detected only in Clades 1 and 6 while B. henselae and R. asembonensis were detected only in Clade 4. Wolbachia spp., also displayed clade specificity with strains other than Wolbachia wCfeT only infecting fleas from Clade 6. There was poor flea and host agreement for Bartonella spp., infection; however, there was agreement in the Bartonella species detected in cats and fleas by geographic location. These findings reinforce the importance of considering reservoir host attributes and vector phylogenetic diversity in epidemiological studies of flea-borne pathogens. Widespread sampling is necessary to identify the factors driving flea-borne pathogen presence and transmission.

Molecular analysis of blood-associated pathogens in European wildcats (Felis silvestris silvestris) from Germany

European wildcats (Felis silvestris silvestris) have not been investigated in large numbers for blood-associated pathogens in Germany, because wildcats, being a protected species, may not be hunted, and the collection of samples is therefore difficult. Thus, spleen tissue and whole blood from 96 wildcats from Germany found as roadkill or dead from other causes in the years 1998–2020 were examined for the prevalence of blood associated pathogens using molecular genetic tools. PCR was used to screen for haemotrophic Mycoplasma spp., Hepatozoon spp., Cytauxzoon spp., Bartonella spp., Filarioidea, Anaplasmataceae, and Rickettsiales, and positive samples were subsequently sequenced. Phylogenetic analyses were performed for Mycoplasma spp. and Hepatozoon spp. by calculating phylogenetic trees and DNA haplotype networks. The following pathogens were found: Candidatus Mycoplasma haematominutum (7/96), Mycoplasma ovis (1/96), Hepatozoon silvestris (34/96), Hepatozoon felis (6/96), Cytauxzoon europaeus (45/96), and Bartonella spp. (3/96). This study elucidates the prevalence of blood-associated pathogens in wildcats from Germany.

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European wildcats from Germany carry different blood-associated pathogens.

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Pathogens can also affect domestic cats.

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Transmision by vectors or other transmisison routes are possible.

Prevalence and Risk Factors for Bartonella spp. and Haemoplasma Infections in Cats from Greece

Simple Summary

Bartonellosis and haemoplasmosis are diseases with global impact on the health of domestic cats and of zoonotic importance. This is the first study investigating the risk factors for Bartonella spp. and haemoplasma species infections in cats from Greece. In addition, this study determined the serologic and molecular prevalence of Bartonella spp. and haemoplasma species infections in different populations of cats living in different regions of Greece. A total of 452 cats were enrolled into the study. Blood was collected from each cat for the serological detection of Bartonella henselae antibodies and the molecular detection of Bartonella spp. and haemoplasma species infections. Overall, the seroprevalence of B. henselae was 35.4%, while the molecular prevalence of Bartonella spp. and haemoplasma species was 2.9% and 19%, respectively. The results of this study indicate that cats with partial or exclusive outdoor access and cats with flea infestation are at the greatest risk for B. henselae seropositivity. Furthermore, cats living in warmer regions such as Attica and Crete are at the greatest risk. Lack of ectoparasiticide use was identified as a risk factor for haemoplasma species infection. This suggests that the use of ectoparasiticides in cats may be an effective means of preventing haemoplasma species infection in cats.

Abstract

Bartonellosis and haemoplasmosis are vector-borne diseases with global impact on the health of domestic cats and of zoonotic importance. The aim of this study was to describe the epidemiological aspects of various populations of cats infected with Bartonella spp. or haemoplasma species. The populations evaluated included client-owned cats, stray cats and cats that live in breeding catteries in Greece. A total of 452 cats were prospectively enrolled into the study. A commercially available indirect immunofluorescence antibody testkit was used for the detection of Bartonella henselae IgG antibodies in serum. PCRs for the detection of Bartonella spp. and haemoplasma species DNA in the blood were also performed in a subgroup of 242 of the 452 cats. Risk factors for B. henselae seropositivity and infection with the haemoplasma species were determined using multivariable analysis. Overall, 160 (35.4%) of the 452 cats were seropositive for B. henselae. Seven (2.9%) and 46 (19%) of the 242 cats were PCR-positive for Bartonella spp. and haemoplasma species, respectively. The factors associated with B. henselae seropositivity, based on multivariate analysis, included older age, outdoor access, living region and flea infestation. Non-administration of ectoparasiticides was associated with haemoplasma species infection. This study shows a high prevalence of seropositivity for B. henselae and a relatively high prevalence of infection with haemoplasma species. Therefore, it is necessary to establish optimal strategies for the prevention of Bartonella spp. and haemoplasma species infections, considering the high-risk groups of cats identified in this study.

Prevalence of Vector-Borne Pathogens in Reproductive and Non-Reproductive Tissue Samples from Free-Roaming Domestic Cats in the South Atlantic USA

Reservoir to multiple species of zoonotic pathogens, free-roaming cats (FRCs) interact with domestic and wild animals, vectors, and humans. To assess the potential for feline vector-borne pathogens to be vertically transmitted, this study surveyed ear tip and reproductive tissues of FRCs from two locations in the South Atlantic United States for Anaplasma, Bartonella, Ehrlichia, hemotropic Mycoplasma, and Rickettsia species. We collected ovary (n = 72), uterus (n = 54), testicle (n = 74), and ear tip (n = 73) tissue from 73 cats, and fetal (n = 20) and placental (n = 19) tissue from 11 queens. Pathogen DNA was amplified utilizing qPCR, confirmed by sequencing. Cats were more frequently Bartonella henselae positive on reproductive tissues (19%, 14/73) than ear tip (5%, 4/73; p = 0.02). B. henselae was amplified from fetus (20%, 4/20) and placenta samples (11%, 2/19). Bartonella spp. infection was more common in cats from North Carolina (76%, 26/34) than Virginia (13%, 5/39; p < 0.0001). Fourteen percent (10/73) of both ear tip and reproductive tissues were positive for hemotropic Mycoplasma spp. Anaplasma, Ehrlichia, and Rickettsia spp. DNA was not amplified from any cat/tissue. These findings suggest that B. henselae preferentially infected cats' reproductive tissue and reinforces the importance of investigating the potential for B. henselae vertical transmission or induction of reproductive failure.

Zoonotic and vector-borne pathogens in tigers from a wildlife safari park, Italy

Infectious diseases by pathogens, including those of zoonotic concern, may act as a primary or contributory cause of threat to wildlife conservation and may represent a risk for human health, mainly for people working at, or visiting the zoological parks. Given the paucity of data on pathogens infecting wild tigers, we investigated the occurrence of infectious agents in this animal species, with a special focus on those of zoonotic concern. Blood and serum samples from tigers (n = 20) living in a wildlife safari park of southern Italy were screened by serological and molecular tests. All animals scored positive for antibodies against Toxoplasma gondii (100%), whereas they displayed different prevalence of seropositivity for Rickettsia conorii (30%), Bartonella henselae (15%) and Leptospira interrogans sv Icterohaemorrhagiae and/or Leptospira kirschneri sv Grippotyphosa (15%). No antibodies against Coxiella burnetii were detected. In addition, 8 tigers (40%) tested molecularly positive to "Candidatus Mycoplasma haemominutum", and 3 (15%) to Hepatozoon canis. No DNA of R. conorii, Bartonella spp., Ehrlichia/Anaplasma spp. and piroplasmids was amplified. The occurrence of tiger infections by bacteria and parasites may represent a risk for morbidity and, in some circumstances, mortality in this endangered species and a source of infection for other animals, including humans. These findings indicate that the circulation of zoonotic pathogens such as T. gondii, R. conorii, L. interrogans sv Icterohaemorrhagiae, "Candidatus Mycoplasma haemominutum" and B. henselae in given environments may represent a relevant health issue considering the close association among animals and humans visiting, or working at, the wildlife safari park. Preventative measures are advocated in order to control ectoparasites and other sources of infection (e.g., small rodents), thus for minimizing the risk of infection for animals as well as for humans.

Update on Feline Hemoplasmosis

"The wall-less, hemotropic, mycoplasma species Mycoplasma haemofelis, "Candidatus Mycoplasma turicensis" and, to a lesser extent, "Candidatus Mycoplasma haemominutum" have the potential to induce clinical hemolytic anemia in infected cats. Prevalence varies markedly between infecting species, complicated by a chronic carrier state. Accurate and prompt confirmation of infection and identification of the infecting hemoplasma species enables appropriate antibiotics (eg, tetracycline; fluoroquinolone) to be prescribed. Although cats with hemoplasmosis respond rapidly to antibiosis and supportive care, initial monotherapy treatment rarely results in clearance of infection. A protocol now exists for the clearance of the most pathogenic feline hemoplasma M haemofelis."

Transmission pathways and spillover of an erythrocytic bacterial pathogen from domestic cats to wild felids

Many pathogens infect multiple hosts, and spillover from domestic to wild species poses a significant risk of spread of diseases that threaten wildlife and humans. Documentation of cross-species transmission, and unraveling the mechanisms that drive it, remains a challenge. Focusing on co-occurring domestic and wild felids, we evaluate possible transmission mechanisms and evidence of spillover of "Candidatus Mycoplasma haemominutum" (CMhm), an erythrocytic bacterial parasite of cats. We examine transmission and possibility of spillover by analyzing CMhm prevalence, modeling possible transmission pathways, deducing genotypes of CMhm pathogens infecting felid hosts based on sequences of the bacterial 16S rRNA gene, and conducting phylogenetic analyses with ancestral state reconstruction to identify likely cross-species transmission events. Model selection analyses suggest both indirect (i.e., spread via vectors) and direct (i.e., via interspecific predation) pathways may play a role in CMhm transmission. Phylogenetic analyses indicate that transmission of CMhm appears to predominate within host species, with occasional spillover, at unknown frequency, between species. These analyses are consistent with transmission by predation of smaller cats by larger species, with subsequent within-species persistence after spillover. Our results implicate domestic cats as a source of global dispersal and spillover to wild felids via predation. We contribute to the emerging documentation of predation as a common means of pathogen spillover from domestic to wild cats, including pathogens of global conservation significance. These findings suggest risks for top predators as bioaccumulators of pathogens from subordinate species.

Vector-borne diseases in cats in Germany

Vector-borne diseases (VBDs) are caused by a wide range of pathogens, which are transmitted by a variety of vectors, such as ticks and fleas. As a result of climate changes, more vector-borne diseases are becoming endemic in Germany, not only in dogs, but also in cats. For some of the pathogens prevalence data still need to be investigated in Germany. However, natural infections with Bartonella, Anaplasma, haemotropic Mycoplasma and Borrelia species have already been described in German cats. Clinical relevance of these pathogens is not fully understood, and it is still unknown, why most infected cats stay asymptomatic and which predisposing factors contribute to the development of clinical signs in cats. Moreover, there is a risk of zoonotic transmission for some of the pathogens, e.  g., for some Bartonella spp. infections that are associated with cat scratch disease in humans. Due to the increasing number of VBDs in cats in Germany, preventive measures, such as the use of acaricides and insecticides, should be performed on a regular base in order to reduce the risk of these infections.

From endosymbionts to host communities: factors determining the reproductive success of arthropod vectors

Elucidating the factors determining reproductive success has challenged scientists since Darwin, but the exact pathways that shape the evolution of life history traits by connecting extrinsic (e.g., landscape structure) and intrinsic (e.g., female's age and endosymbionts) factors and reproductive success have rarely been studied. Here we collected female fleas from wild rodents in plots differing in their densities and proportions of the most dominant rodent species. We then combined path analysis and model selection approaches to explore the network of effects, ranging from micro to macroscales, determining the reproductive success of these fleas. Our results suggest that female reproductive success is directly and positively associated with their infection by Mycoplasma bacteria and their own body mass, and with the rodent species size and total density. In addition, we found evidence for indirect effects of rodent sex and rodent community diversity on female reproductive success. These results highlight the importance of exploring interrelated factors across organization scales while studying the reproductive success of wild organisms, and they have implications for the control of vector-borne diseases.

Passive immunization does not provide protection against experimental infection with Mycoplasma haemofelis

Mycoplasma haemofelis (Mhf) is the most pathogenic feline hemotropic mycoplasma. Cats infected with Mhf that clear bacteremia are protected from Mhf reinfection, but the mechanisms of protective immunity are unresolved. In the present study we investigated whether the passive transfer of antibodies from Mhf-recovered cats to naïve recipient cats provided protection against bacteremia and clinical disease following homologous challenge with Mhf; moreover, we characterized the immune response in the recipient cats. Ten specified pathogen-free (SPF) cats were transfused with pooled plasma from cats that had cleared Mhf bacteremia; five control cats received plasma from naïve SPF cats. After homologous challenge with Mhf, cats were monitored for 100 days using quantitative PCR, hematology, blood biochemistry, Coombs testing, flow cytometry, DnaK ELISA, and red blood cell (RBC) osmotic fragility (OF) measurement. Passively immunized cats were not protected against Mhf infection but, compared to control cats, showed significantly higher RBC OF and B lymphocyte (CD45R/B220⁺) counts and occasionally higher lymphocyte, monocyte and activated CD4⁺ T lymphocyte (CD4⁺CD25⁺) counts; they also showed higher bilirubin, total protein and globulin levels compared to those of control cats. At times of peak bacteremia, a decrease in eosinophils and lymphocytes, as well as subsets thereof (B lymphocytes and CD5⁺, CD4⁺ and CD8⁺ T lymphocytes), and an increase in monocytes were particularly significant in the passively immunized cats. In conclusion, passive immunization does not prevent bacteremia and clinical disease following homologous challenge with Mhf, but enhances RBC osmotic fragility and induces a pronounced immune response.

Similarities and seasonal variations in bacterial communities from the blood of rodents and from their flea vectors

Vector-borne microbes are subject to the ecological constraints of two distinct microenvironments: that in the arthropod vector and that in the blood of its vertebrate host. Because the structure of bacterial communities in these two microenvironments may substantially affect the abundance of vector-borne microbes, it is important to understand the relationship between bacterial communities in both microenvironments and the determinants that shape them. We used pyrosequencing analyses to compare the structure of bacterial communities in Synosternus cleopatrae fleas and in the blood of their Gerbillus andersoni hosts. We also monitored the interindividual and seasonal variability in these bacterial communities by sampling the same individual wild rodents during the spring and again during the summer. We show that the bacterial communities in each sample type (blood, female flea or male flea) had a similar phylotype composition among host individuals, but exhibited seasonal variability that was not directly associated with host characteristics. The structure of bacterial communities in male fleas and in the blood of their rodent hosts was remarkably similar and was dominated by flea-borne Bartonella and Mycoplasma phylotypes. A lower abundance of flea-borne bacteria and the presence of Wolbachia phylotypes distinguished bacterial communities in female fleas from those in male fleas and in rodent blood. These results suggest that the overall abundance of a certain vector-borne microbe is more likely to be determined by the abundance of endosymbiotic bacteria in the vector, abundance of other vector-borne microbes co-occurring in the vector and in the host blood and by seasonal changes, than by host characteristics.

Molecular detection of hemotrophic mycoplasmas among domiciled and free-roaming cats in Campo Grande, state of Mato Grosso do Sul, Brazil

Hemoplasmas are bacteria living in feline red blood cells. Feline hemoplasmosis is frequently associated with old male cats that have access to the streets. This study aimed to detect the presence of hemoplasma speciess in domiciled and free-roaming cats in Campo Grande, state of Mato Grosso do Sul (MS), Brazil, using molecular techniques. Between January 2013 and April 2013, EDTA-whole blood samples were collected from 151 domestic cats (65 free-roaming and 86 domiciled cats). Samples were subjected to PCR assays targeting hemoplasmas 16S rRNA, followed by sequencing, BLAST analysis and phylogenetic analysis. Results show an occurrence of 36.4% for hemoplasmas. Twenty-three cats (15.2%) were positive for ‘Candidatus Mycoplasma haemominutum’, 17 (11.2%) for M. haemofelis and 15 (9.9%) for ‘Candidatus M. turicensis’, from PCR. Coinfection by two or three hemoplasmas was found in 25 cats (16.6%). No statistically significant difference between genders or between lifestyles was observed for the presence of hemoplasmas among the cats. Results show different hemoplasma species are present in cat population (Campo Grande, MS, Brazil). It is suggested that a differential diagnosis for feline hemoplasmosis should be made when cats show nonspecific clinical signs of disease with systemic manifestation.

Non-ribosomal phylogenetic exploration of Mollicute species: new insights into haemoplasma taxonomy

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The first gapA and dnaK phylogenetic analysis of Mollicute species.

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Analysis includes a wide range of haemoplasmas species.

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Analysis supports that haemoplasmas reside within a single clade.

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Evidence of phylogenetic distance between the haemoplasmas and Mycoplasma species.

Nine species of uncultivable haemoplasmas and several Mycoplasma species were examined by partial sequencing of two protein-encoding housekeeping genes. Partial glyceraldehyde-3-phosphate dehydrogenase (gapA) and heat shock protein 70 (dnaK) gene sequences were determined for these Mollicute species; in total nine gapA sequences and ten dnaK sequences were obtained. Phylogenetic analyses of these sequences, along with those of a broad selection of Mollicute species downloaded from GenBank, for the individual genes, and for the gapA and dnaK concatenated data set, revealed a clear separation of the haemoplasmas from other species within the Mycoplasma genus; indeed the haemoplasmas resided within a single clade which was phylogenetically detached from the pneumoniae group of Mycoplasmas. This is the first report to examine the use of gapA and dnaK, as well as a concatenated data set, for phylogenetic analysis of the haemoplasmas and other Mollicute species. These results demonstrate a distinct phylogenetic separation between the haemoplasmas and Mycoplasmas that corresponds with the biological differences observed in these species, indicating that further evaluation of the haemoplasmas’ relationship with the Mycoplasma genus is required to determine whether reclassification of the haemoplasmas is necessary.

Prevalence and risk factor analysis of feline haemoplasma infection in New Zealand domestic cats using a real-time PCR assay

Haemotropic mycoplasmas (haemoplasmas) are small epierythrocytic bacteria that have the potential to cause severe, life-threatening haemolytic anaemia. The aim of the current study was to evaluate feline haemoplasma prevalence using real-time polymerase chain reaction (PCR) from a convenience sample of New Zealand domestic cats, including blood film examination and a risk factor analysis. DNA was extracted from 200 blood samples submitted to a diagnostic laboratory for routine haematology over a 12-month period. Species-specific real-time PCR assays identified 62 cats that were positive for haemoplasma DNA, giving an overall prevalence of 31%. Twelve of the positive cats had dual infections. The prevalence of the three feline haemoplasmas was 25% for 'Candidatus Mycoplasma haemominutum', 7.5% for Mycoplasma haemofelis and 4.5% for 'Candidatus Mycoplasma turicensis' (CMt). All samples were positive for an internal control (feline 28S rDNA) by real-time PCR. Sensitivity and specificity of blood smear examination for haemoplasma infection in this study was 9.7% and 97.8%, respectively. Retroviral infection was tested using the Idexx Snap Feline Triple test on all samples. Twenty cats (10%) were feline immunodeficiency virus (FIV) positive and 11 cats (5.5%) were feline leukaemia virus (FeLV) positive. Statistical comparisons, using multivariate logistic regression, indicated that positive FIV status, male gender and non-pedigree breed were significantly (P <0.05) associated with haemoplasma infection, with odds ratios of 10.16, 5.04 and 3.03, respectively. The results of this study demonstrate the prevalence of the three main feline haemoplasma species in New Zealand for the first time, with prevalences correlating with previous overseas studies. This is the first report of CMt in New Zealand.

Haemoplasmas: lessons learnt from cats

The haemotropic mycoplasmas (haemoplasmas) are a group of bacteria that can induce anaemia in a wide variety of mammals, including domestic cats and wild felids. Different feline haemoplasma species of varying pathogenicity exist, with the more pathogenic Mycoplasma haemofelis (Mhf) capable of inducing severe haemolytic anaemia, whilst 'Candidatus Mycoplasma haemominutum' (CMhm) and 'Candidatus Mycoplasma turicensis' (CMt) are infrequently associated with clinical disease. Chronic haemoplasma infections are common and cats are frequently infected by two or more haemoplasmas, complicating the clinical picture. The natural route of transmission of haemoplasma infection between cats has not yet been determined; however, experimental transmission has been demonstrated via both oral and parenteral administration of infected blood. To date the haemoplasmas have been unable to be cultured in vitro, and accurate diagnosis is currently reliant on detection of bacterial DNA using PCR assays. Treatment of clinical haemoplasmosis is focussed on supportive care in combination with empirical treatment with antimicrobials (tetracyclines or fluoroquinolones). A significant number of asymptomatic cats are positive for haemoplasma infection. These cats may play a role in the maintenance of haemoplasma infection within a population, and need to be considered when choosing potential blood donors. Use of PCR assays has provided an accurate method of diagnosing haemoplasma infection and quantifying response to therapy, including in non-feline host animals, as presumed zoonotic haemoplasma infections are now being documented. Recent advances in genome sequencing techniques have allowed the whole genome sequences of the feline haemoplasmas Mhf and CMhm to be derived, as well as a number of non-feline haemoplasma species. These data have aided the identification of antigens for use in the development of serological tests, allowed the proteomic study of haemoplasmas and provided clues as to how the haemoplasmas can persist within the host. Future areas of study include investigation of their zoonotic potential, mechanisms of immune system evasion and transmission of these emerging pathogens.

Molecular detection of hemoplasma infection among cats from São Luís island, Maranhão, Brazil

Hemoplasmas are bacteria that infect erythrocytes, attaching to the red blood cell. There is a need for more reports of hemoplasma infection prevalence and molecular characterization among cats in Brazil since there are only few published reports. The present work aimed to detect and molecularly characterize the presence of hemotrophic mycoplasmas in domestic cats with outdoor access from São Luís, Maranhão, Brazil. Twenty cats (10%) were positive for Candidatus M. haemominutum, five (2.5%) for M. haemofelis, and four (2.%) for M. turicensis based on 16S rRNA gene PCRs. Five cats (2.5%) were co-positive for Candidatus M. haemominutum and M. haemofelis. PCR diagnosis was confirmed by sequencing; and phylogenetic analysis was based on 16S rRNA and rnpb genes.

Polymerase chain reaction survey of feline haemoplasma infections in Greece

The aim of this study was to use real-time polymerase chain reaction assays to determine the prevalence of three haemoplasma species in cats from Greece and to evaluate possible associations between haemoplasma infection and age, gender, feline immunodeficiency virus/feline leukaemia virus (FIV/FeLV) status and packed cell volume (PCV). Ninety-seven cats (24 ill anaemic, 55 ill non-anaemic, 18 healthy non-anaemic) were included in the study. Twenty cats (20.6%) were haemoplasma positive; seven cats were infected only with Mycoplasma haemofelis, 10 were infected only with ‘ Candidatus Mycoplasma haemominutum’ and three were co-infected with M haemofelis and ‘ Candidatus M haemominutum’. ‘ Candidatus Mycoplasma turicensis’ was not detected. Haemoplasma infection was associated with older age ( P=0.019). M haemofelis infection tended to be more common in anaemic cats ( P=0.058). No association between gender and haemoplasma infection, or haemoplasma relative copy number and PCV, was detected. Retroviral infection rates were very low with only one FeLV proviral positive cat found.

Prevalence of selected infectious agents in cats in Ireland

Vector-borne bacterial and rickettsial agents and Toxoplasma gondii, are common organisms in cats. Some are potentially zoonotic or may be transmitted via blood transfusion. The current study investigated the prevalence of these agents in cats from Dublin, Ireland, for which no published data exists. Whole blood (n=116) and sera (n=83) samples were obtained from 121 cats. DNA was extracted from blood and assayed using polymerase chain reaction techniques for Anaplasma species, Bartonella species, Ehrlichia species, Mycoplasma haemofelis, 'Candidatus Mycoplasma haemominutum', 'Candidatus Mycoplasma turicensis' and Rickettsia species. IgG and T gondii IgG and IgM serum antibodies were detected by enzyme-linked immunosorbent assay. DNA consistent with B henselae (3.4%), B clarridgeiae (0.8%), both Bartonella species (0.8%), C M haemominutum (12.9%), or M haemofelis (2.5%) was amplified from 24/116 blood samples (20.6%). Antibodies to T gondii and Bartonella species were detected in 28 (33.7%) and 22 (26.5%) of 83 sera, respectively.

In vivo transmission studies of 'Candidatus Mycoplasma turicensis' in the domestic cat

The natural transmission routes of the three feline haemotropic mycoplasmas – Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’, and ‘Candidatus Mycoplasma turicensis’ (CMt) – are largely unknown. Since CMt has been detected in the saliva of infected cats using PCR, we hypothesised that direct transmission via social or aggressive contact may occur. The aim of this study was to evaluate this transmission route. CMt-positive saliva and blood samples were obtained from three prednisolone-treated specific pathogen-free (SPF) cats that were infected intraperitoneally with CMt. Five SPF cats were inoculated with CMt-positive saliva or blood subcutaneously to mimic cat bites, and five cats were inoculated orally with blood or oronasally with saliva to mimic social contact. Blood samples were monitored for CMt infection using quantitative real-time PCR and for seroconversion using a novel western blot assay. Neither oronasal nor subcutaneous inoculation with CMt-positive saliva led to CMt infection in the recipient cats, as determined by PCR, independent of prior prednisolone treatment. However, when blood containing the same CMt dose was given subcutaneously, 4 of the 5 cats became PCR-positive, while none of the 5 cats inoculated orally with up to 500 μL of CMt-positive blood became PCR-positive. Subsequently, the latter cats were successfully subcutaneously infected with blood. All 13 CMt-exposed cats seroconverted. In conclusion, CMt transmission by social contact seems less likely than transmission by aggressive interaction. The latter transmission may occur if the recipient cat is exposed to blood from an infected cat.

Use of combined conventional and real-time PCR to determine the epidemiology of feline haemoplasma infections in northern Italy

Although knowledge of feline haemotropic mycoplasmas (haemoplasmas) has dramatically improved in recent years, some issues still remain to be elucidated. The aim of the current study was to evaluate the prevalence of feline haemoplasma infections in blood samples collected from cats in northern Italy. A convenience-sample of 307 cats (40 anaemic; 258 non-anaemic; nine with unknown haematocrit [HCT]) was investigated using polymerase chain reaction assays. Furthermore, the date of blood collection, signalment and clinicopathological data were retrospectively evaluated to assess predictors and risk factors for infection. Haemoplasma infections were highly prevalent in the sample investigated with an overall prevalence of 18.9% (95% confidence interval: 14.5-23.3%). The prevalence for the three feline haemoplasmas was 17.3% for 'Candidatus Mycoplasma haemominutum' (CMhm), 5.9% for Mycoplasma haemofelis (Mhf) and 1.3% for 'Candidatus Mycoplasma turicensis' (CMt). Feline immunodeficiency virus-positive status represented a risk factor for infection with an odds ratio of 4.19 (P=0.02). Moreover, a higher prevalence was observed in summer (odds ratio 1.78; P=0.04) which may be consistent with arthropod-borne disease transmission. Cats infected with Mhf showed significantly lower HCT (P=0.03), haemoglobin values (P=0.02) and red blood cell counts (P=0.04), lower mean corpuscular haemoglobin concentration (P<0.01) and higher white blood cell counts (P<0.01) when compared with non-infected cats.

“Candidatus Mycoplasma haemominutum” Infections in 21 Client-Owned Cats

Medical records were reviewed for 21 clinically ill cats testing positive for deoxyribonucleic acid (DNA) of “Candidatus Mycoplasma haemominutum” in their blood. Fever, anorexia, lethargy, and anemia were among the most common abnormalities recorded. Thirteen cats were anemic; seven had evidence of other diseases that could have been the primary cause of anemia or activated hemoplasmosis. For six cats, “Candidatus Mycoplasma haemominutum” was the only recognizable cause of the anemia. Of these cats, anemia resolved in one cat without treatment and in three cats that were treated with doxycycline, with or without prednisone. Results of the study suggest that this hemoplasma species can be a primary pathogen in cats.

Real-time PCR investigation of potential vectors, reservoirs, and shedding patterns of feline hemotropic mycoplasmas

Three hemotropic mycoplasmas have been identified in pet cats: Mycoplasma haemofelis, "Candidatus Mycoplasma haemominutum," and "Candidatus Mycoplasma turicensis." The way in which these agents are transmitted is largely unknown. Thus, this study aimed to investigate fleas, ticks, and rodents as well as saliva and feces from infected cats for the presence of hemotropic mycoplasmas, to gain insight into potential transmission routes for these agents. DNA was extracted from arthropods and from rodent blood or tissue samples from Switzerland and from salivary and fecal swabs from two experimentally infected and six naturally infected cats. All samples were analyzed with real-time PCR, and some positive samples were confirmed by sequencing. Feline hemotropic mycoplasmas were detected in cat fleas and in a few Ixodes sp. and Rhipicephalus sp. ticks collected from animals but not in ticks collected from vegetation or from rodent samples, although the latter were frequently Mycoplasma coccoides PCR positive. When shedding patterns of feline hemotropic mycoplasmas were investigated, "Ca. Mycoplasma turicensis" DNA was detected in saliva and feces at the early but not at the late phase of infection. M. haemofelis and "Ca. Mycoplasma haemominutum" DNA was not amplified from saliva and feces of naturally infected cats, despite high hemotropic mycoplasma blood loads. Our results suggest that besides an ostensibly indirect transmission by fleas, direct transmission through saliva and feces at the early phase of infection could play a role in the epizootiology of feline hemotropic mycoplasmas. Neither the investigated tick nor the rodent population seems to represent a major reservoir for feline hemotropic mycoplasmas in Switzerland.

Prevalence of DNA of Mycoplasma haemofelis, 'Candidatus Mycoplasma haemominutum,' Anaplasma phagocytophilum, and species of Bartonella, Neorickettsia, and Ehrlichia in cats used as blood donors in the United States

OBJECTIVE

To identify the prevalence of DNA of Mycoplasma haemofelis; 'Candidatus Mycoplasma haemominutum'; Anaplasma phagocytophilum; and species of Bartonella, Neorickettsia, and Ehrlichia in blood of cats used as blood donors in the United States.

DESIGN

Prospective study.

ANIMALS

146 cats that were active blood donors.

PROCEDURES

Environmental history was requested for each blood-donor cat from which a blood sample (mixed with EDTA) was available. Polymerase chain reaction assays capable of amplifying the DNA of the microorganisms of interest following DNA extraction from blood were performed.

RESULTS

Overall, DNA of one or more of the infectious agents was detected in blood samples from 16 of 146 (11%) feline blood donors. Twenty-eight laboratory-reared cats housed in a teaching hospital had negative results for DNA of all organisms investigated. The DNA of at least 1 infectious agent was amplified from blood samples collected from 16 of 118 (13.6%) community-source cats; assay results were positive for 'Candidatus M haemominutum,' M haemofelis, or Bartonella henselae alone or in various combinations. Of the community-source cats allowed outdoors (n = 61) or with known flea exposure (44), DNA for a hemoplasma or B henselae was detected in 21.3% and 22.7%, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

When community-source cats, cats allowed outdoors, or cats exposed to fleas are to be used as blood donors, they should be regularly assessed for infection with M haemofelis, 'Candidatus M haemominutum,' and Bartonella spp, and flea-control treatment should be regularly provided.