Detection frequency of haemoplasma infections of the domestic cat in Germany

We present epidemiological data on the frequency of infections with haemotrophic Mycoplasma spp. (feline haemoplasmas) in domestic cats in Germany. From November 2004 to October 2006 135 blood samples of anaemic patients and cats without clinical symptoms were examined with conventional and real-time PCR methods. In 15,6 % of the samples DNA of one or more haemoplasma species could be detected. 8,9 % of the samples (12 cats) were infected with "Candidatus Mycoplasma haemominutum, whereas 7,4 % (10 cats) were infected with Mycoplasma haemofelis. Out of these, one cat harboured both species.The recently described species "Candidatus Mycoplasma turicensis" was found in 2.2 % of all samples (3 cats) and was restricted to animals coinfected with M. haemofelis. No correlation could be detected between the infection with haemotrophic Mycoplasma spp. and clinical signs of anaemia or disease. Infections were significantly correlated with age, male gender or coinfections with retroviruses (FIV, FeLV). Our data indicate, that chronically infected carriers without clinical symptoms are frequent in the investigated cat populations in Germany and that the screening of blood-donors for the presence of Mycoplasma spp. infections is advisable before clinical use.     

Prevalences of various hemoplasma species among cats in the United States with possible hemoplasmosis

OBJECTIVE: To determine prevalences of various hemoplasma species among cats in the United States with possible hemoplasmosis and identify risk factors for and clinicopathologic abnormalities associated with infection with each species. DESIGN: Cross-sectional study. Animals-310 cats with cytologic evidence of hemoplasmosis (n = 9) or acute or regenerative anemia (309). PROCEDURES: Blood samples were tested by means of a broad-spectrum conventional PCR assay for hemoplasma DNA and by means of 3 separate species-specific real-time PCR assays for DNA from "Candidatus Mycoplasma haemominutum" (Mhm), Mycoplasma haemofelis (Mhf), and "Candidatus Mycoplasma turicensis" (Mtc). RESULTS: Overall prevalences of Mhm, Mhf, and Mtc infection were 23.2% (72/310), 4.8% (15/310), and 6.5% (20/310), respectively. Mixed infections were detected in 20 (6.5%) cats. Cats infected with hemoplasmas were more likely to be male than were uninfected cats. Infection with FeLV or FIV was significantly associated with infection with Mhf. Compared with uninfected cats, cats infected with Mhf had higher reticulocyte counts, nucleated RBC counts, and mean corpuscular volume; cats infected with Mhm had higher mean corpuscular volume; and cats infected with Mtc had higher monocyte counts. CONCLUSIONS AND CLINICAL RELEVANCE: Results supported the suggestion that these 3 hemoplasma species commonly occur among cats in the United States and that pathogenicity of the 3 species varies.     

Mycoplasma haemofelis and Mycoplasma haemominutum detection by polymerase chain reaction in cats from Saskatchewan and Alberta

Hemobartonellosis is caused by Mycoplasma haemofelis, previously known as Haemobartonella felis. Cats infected with this organism typically develop regenerative anemia. The related species Mycoplasma haemominutum may also cause anemia. The purposes of this study were to use polymerase chain reaction technology to determine if both organisms exist in naturally infected cats from Saskatchewan and Alberta, and to determine if disease manifestation corresponds to mycoplasma species. Thirteen of 18 cats with regenerative anemia were infected, 12 with M. haemofelis and 1 with M. haemominutum. Eight of 22 cats with nonregenerative anemia were infected, 4 with M. haemofelis and 4 with M. haemominutum. Two of 20 cats with normal complete blood (cell) counts were infected with M. haemominutum. Although both mycoplasma species were identified, ill cats were more often infected with M. haemofelis.     

Hemoplasmas in wild canids and felids in Brazil

Hemotropic mycoplasmas, epicellular erythrocytic bacterial parasites lacking a cell wall, are the causative agents of infectious anemia in numerous mammalian species. The presence of hemotropic mycoplasmas in blood samples of neotropical and exotic wild canids and felids from Brazilian zoos were recorded using molecular techniques. Blood samples were collected from 146 Brazilian wild felids, 19 exotic felids, 3 European wolves (Canis lupus), and from 97 Brazilian wild canids from zoos in the Brazilian states of S?o Paulo and Mato Grosso and the Federal District. Using conventional polymerase chain reaction (PCR), this work found 22 (13%) wild felids positive to Candidatus Mycoplasma haemominutum [4 jaguars (Panthera onca); 3 pumas (Puma concolor); 10 ocelots (Leopardus pardalis); 2 jaguarondis (Puma yagouaroundi); and 3 little spotted cats (Leopardus tigrinus)]. Only one little spotted cat (Leopardus tigrinus) was positive to Mycoplasma haemofelis, and none was positive to Candidatus Mycoplasma turicensis. Two bush dogs (Speothos venaticus) were positive for a Mycoplasma sp. closely related to Candidatus Mycoplasma haematoparvum, and two European wolves were positive for a Mycoplasma sp. closely related to Candidatus Mycoplasma haemominutum. This is the first study regarding the molecular detection of hemotropic mycoplasmas in wild canids.     

Feline hemotropic mycoplasmosis (feline hemobartonellosis).

Hemotropic mycoplasmas represent an important cause of anemia in cats worldwide. Previously known as Haemobartonella species, sequencing of the 16S rRNA genes of these organisms has led to their reclassification as mycoplasmas. Two species have been identified in cats, M haemofelis and "Candidatus M haemominutum." The latter organism alone has not been associated with disease in naturally infected cats but may cause anemia in FeLV-infected cats and accelerate development of FeLV-induced myeloproliferative disease. The mode of transmission of these organisms remains enigmatic. Nevertheless, development of sensitive DNA-based tests for these unculturable organisms has improved the understanding of the epidemiology and pathogenesis of FHM. Cats with clinical signs and laboratory abnormalities consistent with FHM should be treated with doxycycline; enrofloxacin may represent an effective alternative. Transfusion with packed red blood cells after cross-matching may be required for severely anemia cats, and addition of prednisone may be required if the diagnosis of FHM is uncertain, or response to antimicrobials alone is insufficient. Affected cats should be tested for FeLV, the most common concurrent infection in cats with FHM.     

Immune-mediated erythroid and megakaryocytic aplasia in a cat

CASE DESCRIPTION: A 6-month-old domestic shorthair cat was evaluated because of acute lethargy. CLINICAL FINDINGS: Severe nonregenerative anemia and thrombocytopenia were identified. Cytologic examination of a bone marrow aspirate revealed selective erythroid and mega-karyocytic aplasia and a high number of apparently normal small lymphocytes. Infectious agents implicated in feline hematologic disorders were excluded on the basis of serologic tests or PCR amplification, including FeLV, Ehrlichia canis, Anaplasma phagocytophilum, Mycoplasma haemofelis, Candidatus Mycoplasma haemominutum, and Candidatus Myco-plasma turicensis. TREATMENT AND OUTCOME: A 10-day course of prednisolone administration did not improve the hematologic disorder. Administration of human polyclonal immunoglobulins preceded increased reticulocyte count by 3 days. A second bone marrow examination confirmed restoration of erythroblasts and megakaryocytes. After 1 relapse, the disease was successfully controlled with prednisolone for > 3 years. CLINICAL RELEVANCE: Immune-mediated bone marrow aplasia is rare in cats and usually affects only erythrocyte progenitors. Concomitant involvement of erythroid and megakaryocytic cell lines can be successfully treated via immunosuppressive therapy. Human immunoglobulins seem to be well tolerated in cats; however, proof of a beneficial effect requires further study.     

Use of dried blood smears for detection of feline hemoplasmas using real-time polymerase chain reaction

The objective of the current study was to determine the sensitivity and specificity of real-time polymerase chain reaction (real-time PCR) for feline hemoplasmas when applied to DNA extracted from dried whole-blood smears in comparison to that for DNA extracted from liquid whole blood. Blood samples were collected into ethylenediamine tetra-acetic acid tubes from 305 cats with possible or suspected hemoplasmosis, and dried blood smears from each sample were prepared. DNA was extracted from blood smears and a 160-microl aliquot of each liquid blood sample by using a robotic extractor and was subjected to real-time PCR for feline glyceraldehyde-3-phosphate dehydrogenase (liquid blood), 18S ribosomal RNA (dried blood), and "Candidatus Mycoplasma haemominutum", Mycoplasma haemofelis, and "Candidatus Mycoplasma turicensis" DNA. When using the results for liquid whole blood as the gold standard, the sensitivity of each assay for "Ca. M. haemominutum", M. haemofelis, and "Ca. M. turicensis" was 49 of 66 (74%), 11 of 13 (85%), and 11 of 20 (55%), respectively. The specificity of each assay was 224 of 234 (96%), 287 of 287 (100%), and 280 of 280 (100%), respectively. When possible, liquid blood samples should be submitted for detection of feline hemoplasmas by using real-time PCR. The improved sensitivity of real-time PCR on blood smears for M. haemofelis compared with that of the other hemoplasma species may reflect the higher organism burdens associated with infection with this species.     

Infectious disease prevalence in a feral cat population on Prince Edward Island, Canada

Ninety-six feral cats from Prince Edward Island were used to determine the prevalence of selected infectious agents. The prevalence rates were 5.2% for feline immunodeficiency virus, 3.1% for feline leukemia virus, 3.1% for Mycoplasma haemofelis, 8.4% for Candidatus Mycoplasma haemominutum, 2.1% for Bartonella spp. and 29.8% for exposure to Toxoplasma gondii. Oocysts of T. gondii were detected in 1.3% of the fecal samples that were collected. Gender and retroviral status of the cats were significantly correlated with hemoplasma infections. Use of a flea comb showed that 9.6% of the cats had fleas; however, flea infestation was not associated with any of the infectious agents.     

Anemia associated with 'Candidatus Mycoplasma haemominutum' in a feline leukemia virus-negative cat with lymphoma

'Candidatus Mycoplasma haemominutum,' previously known as the small form of Haemobartonella felis (California species), is a hemotrophic parasite found on erythrocytes of infected cats. Although fleas are potential vectors, confirmatory studies are lacking. Healthy cats infected with 'Candidatus Mycoplasma haemominutum' generally do not have clinically significant anemia, but concurrent disease or immune suppression may predispose a cat to develop a life-threatening anemia, such as in the case reported here.     

Evaluation of experimental transmission of Candidatus Mycoplasma haemominutum and Mycoplasma haemofelis by Ctenocephalides felis to cats

OBJECTIVE: To determine whether Ctenocephalides felis can transmit Mycoplasma haemofelis (Mhf) and Candidatus Mycoplasma haemominutum (Mhm) through hematophagous activity between cats. ANIMALS: 11 cats. PROCEDURE: 2 cats were carriers of either Mhf or Mhm. Nine cats had negative results via polymerase chain reaction (PCR) assay for Mhf and Mhm DNA; 3 of those cats were infected from the chronic carriers via i.v. inoculation of blood. At the time of maximum organism count for each of the Mycoplasma spp, 1 chamber containing 100 C felis was bandaged to the amplifier cats. Five days later, fleas, feces, larvae, or eggs from each chamber were analyzed for Mycoplasma spp DNA. Viable fleas from the chambers were allocated into new chambers (3 Mhm and 6 Mhf) and attached to na?ve cats for 5 days. Cats were monitored daily for clinical signs and weekly via CBC and PCR assay for infection with Mhf or Mhm for a minimum of 8 weeks. RESULTS: Uptake of Mhf and Mhm DNA into fleas, feces, and, potentially, eggs and larvae was detected. Of the na?ve cats fed on by Mhf-infected fleas, 1 cat transiently yielded positive PCR assay results for Mhf on 1 sampling date without clinical or hematologic changes consistent with Mhf infection. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that hematophagous transfer of Mhm and Mhf into fleas occurred and that C felis is a possible vector for Mhf via hematophagous activity.     

From Haemobartonella to hemoplasma: molecular methods provide new insights

Hemotropic mycoplasmas (aka hemoplasmas) are the causative agents of infectious anemia in numerous mammalian species. Originally known as Haemobartonella and Eperythrozoon species, these organisms have been reclassified within the genus Mycoplasma. The development of new molecular assays has expanded our knowledge of this heterogeneous group of agents and allowed us to study their epidemiology and pathogenesis. The present review summarizes recently gained insights into feline hemotropic mycoplasmas, formerly known as Haemobartonella felis. Besides the two initially identified feline hemoplasma species, Mycoplasma haemofelis and Candidatus Mycoplasma haemominutum, we discovered a third novel hemoplasma in a Swiss pet cat; preliminary results suggest that the pathogenic potential of the latter agent depends on cofactors. In applying PCR-based assays, feline hemoplasma infections have been documented in domestic cats and wild felids worldwide. Differences between the three hemoplasmas in regard to response to antibiotic treatment and establishment of a carrier status have been reported. Additionally, besides an ostensible vector-borne transmission, direct transmission by aggressive interaction of cats or interspecies transmission might play a role in the epidemiology of these organisms. Based on a potential vector-borne and interspecies transmission, a zoonotic potential of hemoplasmas should be further investigated.     

Detection of mixed infections with "Candidatus Mycoplasma haemominutum" and Mycoplasma haemofelis using real-time TaqMan polymerase chain reaction.

The objective of this study was to evaluate the use of real-time TaqMan PCR assays for detection of coinfections with "Candidatus Mycoplasma haemominutum" (Mhm), and Mycoplasma haemofelis (Mhf), in vitro and over time in experimentally infected cats. First, the ability of each real-time PCR assay to detect and quantify mixed infections was determined in vitro by testing mixtures of plasmids containing Mhm and Mhf 16S rDNA with each assay. Subsequently, 4 specific pathogen-free (SPF) cats, 2 of which were splenectomized, were inoculated with blood from a cat infected with both Mhm and Mhf. Sixteen blood samples were then collected from each cat over a 55-day period. Each of the 64 postinoculation samples was tested using both conventional polymerase chain reaction (cPCR) and real-time PCR for the 16S rRNA gene of each organism. When applied to mixtures of plasmid DNA from each species, the results of quantitation with each of the real-time PCR assays approximately reflected the number of plasmid copies present. Forty-nine of 64 post-inoculation samples (77%) were positive using both cPCR and real-time PCR, 4 (6%) were positive using cPCR only, and 3 (5%) were positive using real-time PCR only. Both organisms were detected in 23 samples using real-time PCR. Mixed infections were not detected using cPCR. The size of the corresponding cPCR products suggested infection with Mhm in 4 and Mhf in 18 of these samples. The use of multiple separate real-time PCR assays rather than cPCR alone should thus be considered for epidemiologic studies of hemoplasmosis in cats.     

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

OBJECTIVE: To determine whether Mycoplasma haemofelis (Mhf) and Candidatus Mycoplasma haemominutum (Mhm) can be transmitted by ingestion of Mycoplasma-infected Ctenocephalides felis and by-products (feces, larvae, and eggs). ANIMALS: 10 cats. PROCEDURE: 3 cats were carriers of Mhf, and 1 was a carrier of Mhm. Six cats had negative results of PCR assay for Mhf and Mhm DNA. A chamber containing 100 C felis was bandaged to 2 Mhf carrier cats. Five days later, fleas and by-products were analyzed for Mycoplasma spp DNA. The remaining fleas and a sample of by-products were fed to 2 Mycoplasma-na?ve cats. A chamber containing 200 C felis was bandaged to the Mhm carrier cat. Five days later, fleas and by-products were analyzed for Mycoplasma spp DNA. The remaining fleas and a sample of by-products were fed to 2 Mycoplasma-na?ve cats. A chamber containing 200 C felis was bandaged to an Mhf carrier cat and Mhm-carrier cat. Three days later, fleas and by-products were analyzed for Mycoplasma spp DNA. The remaining fleas and a random sample of by products were fed to 4 Mycoplasma-na?ve cats. All cats were monitored for infection for >or=7 weeks. RESULTS: Uptake of Mhf and Mhm DNA into fleas and by-products was detected. None of the na?ve cats became infected. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that ingestion of Mycoplasma-infected C felis or by-products is not an important means of transmission for Mhf or Mhm.     

Identification of a novel hemotropic mycoplasma in a splenectomized dog with hemic neoplasia

A 3-year-old sexually intact male Bull Mastiff underwent splenectomy for splenic thrombosis; prior to and after splenectomy, multiple blood transfusions were administered. Two weeks after the procedure, T-cell lymphoproliferative disease was diagnosed. Treatment with prednisone and chlorambucil was initiated, and 2 weeks later, cytologic examination of a blood smear revealed small (0.3 microm), coccoid basophilic bodies on the surface of approximately 70% of the RBCs. Morphologically, these resembled "Candidatus Mycoplasma haemominutum." A polymerase chain reaction assay was used to amplify a partial 16S rRNA sequence in blood obtained from the dog; the product was sequenced and compared with 16S rRNA gene sequences of other hemotropic mycoplasmas. The sequence was 98% homologous to that of "Candidatus M haemominutum", but only 77% homologous to that of M haemocanis and M haemofelis.     

Chronic "Candidatus Mycoplasma turicensis" infection

"Candidatus Mycoplasma turicensis" infects felids. The pathogenesis of "Candidatus M. turicensis" chronic infection is poorly understood. The goals of the present study were to (1) induce reactivation of the infection in chronic carrier cats by attempted immunosuppression, (2) identify potential tissue sequestration using real-time TaqMan^® PCR and (3) monitor the humoral immune response by DnaK enzyme-linked immunosorbent assay (ELISA). Ten specified pathogen-free cats that had ostensibly recovered from experimental "Candidatus M. turicensis" infection were used: five cats (group 1) received high dose methylprednisolone (attempted immunosuppression), while five cats served as untreated controls (group 2). Besides weekly blood samples, tissue samples were collected from bone marrow, kidney, liver and salivary glands at selected time points. The cats in group 1 had significantly lower lymphocyte counts and higher blood glucose levels after methylprednisolone administration than the controls. After methylprednisolone administration one blood and three tissue samples from cats in group 1 tested PCR-positive; before the administration, only one sample was positive. All other samples tested PCR-negative. All cats stayed seropositive; the antibody levels of the cats in group 1 showed a significant transient decrease after methylprednisolone administration. This is the first study to report the presence of "Candidatus M. turicensis" in tissues of chronically infected cats and the persistence of anti-feline hemoplasma antibodies in the absence of detectable bacteremia. Methylprednisolone administration did not lead to a significant reactivation of the infection. Our results enhance the knowledge of "Candidatus M. turicensis" infection pathogenesis and are clinically relevant to the prognosis of hemoplasma-infected cats.     

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.     

Prevalence,risk factor analysis,and hematological findings of hemoplasma infection in domestic cats from Valdivia,Southern Chile

Four distinct cat hemoplasma species are recognized worldwide. However, this is the first study to investigate the prevalence, risk factors, and hematological findings of hemoplasmas in cats from Chile. Complete blood count and 16S rRNA real-time PCR for cat hemoplasma species were performed in 384 blood samples from domestic cats in Valdivia, Chile. Among the 384 samples the species-specific prevalence was as follows: ‘Candidatus Mycoplasma haemominutum’ (7.8%), Mycoplasma haemofelis (4.4%), ‘Candidatus Mycoplasma turicensis’ (1%), ‘Ca. M. haemominutum’ + M. haemofelis (0.78%), ‘Ca. M. haemominutum’ + ‘Ca. M. turicensis’ (0.52%), ‘Ca. M. haemominutum’ + ‘Candidatus Mycoplasma haematoparvum’ (0.26%) and ‘Ca. M. haemominutum’ + M. haemofelis + ‘Ca. M. haematoparvum’ (0.26%). Male sex, older age, outdoor access, and FIV status were risk factors for hemoplasmosis. Mycoplasma haemofelis-positive cats had higher mean corpuscular volume and monocyte count. Four hemoplasma species circulate in the cat population of Valdivia. ‘Candidatus M. turicensis’ and ‘Ca. M. haematoparvum’ have been reported for the first time in Chilean cats.     

Presence of Mycoplasma haemofelis,Mycoplasma haemominutum and piroplasmids in cats from southern Europe: a molecular study

Clinical symptoms produced by Mycoplasma spp. and piroplasmids in cats are sometimes similar. Diagnosis of these pathogens is difficult by microscopic procedures and molecular methods have been used as an alternative. We present in this work, the development of new molecular procedures for diagnosis of the aforementioned organisms, together with a molecular characterization of isolates found in southern European cats.A single PCR-RFLP procedure was designed for diagnosis of Mycoplasma spp. and a seminested PCR-RFLP was designed for diagnosis of piroplasmids. The 16S or 18S rRNA genes of isolates found in clinical samples were partially sequenced in all positive cases.Mycoplasma spp. was detected in 9 (30%) out of 30 symptomatic cats from Spain. Sequencing indicated that 66.6% of these isolates can be ascribed to Mycoplasma haemofelis and only 33.3% to Mycoplasma haemominutum. Partial 16S rRNA sequences obtained in Spanish isolates were very similar to those previously published from the UK and the USA.The presence of piroplasmids (Babesia and Theileria spp.) was studied in 16 cats from Spain (n=13) and Portugal (n=3). Animals analyzed were 10 cats with immunosuppressive viral infection (either FeLV or FIV), 5 asymptomatic cats and 1 cat with Babesia-compatible symptoms. Asymptomatic cats were all PCR-negative. Partial sequencing of 18S rRNA gene demonstrated that the Babesia-symptomatic cat was infected with Babesia canis canis whereas 3 (30%) out of the 10 cats with immunosuppressive viral infection were coinfected with piroplasmids (1 with B. canis canis, 1 with Theileria annae, and 1 with B. canis canis and T. annae both).     

Prevalence of infectious diseases in feral cats in Northern Florida

Objectives of this study were to determine prevalence of infection in feral cats in Northern Florida with a select group of infectious organisms and to determine risk factors for infection. Blood samples or sera from 553 cats were tested with a panel of antibody, antigen or PCR assays. Male cats were at higher risk for FIV, Mycoplasma haemofelis, and M. haemominutum. Infection with either FeLV or FIV was associated with increased risk for coinfection with the other retrovirus, M. haemofelis, or M. haemominutum. Bartonella henselae had the highest prevalence and was the only organism that did not have any associated risk for coinfection with other organisms. Feral cats in this study had similar or lower prevalence rates of infections than those published for pet cats in the United States. Thus, feral cats assessed in this study appear to be of no greater risk to human beings or other cats than pet cats.