Effect of preexisting FeLV infection or FeLV and feline immunodeficiency virus coinfection on pathogenicity of the small variant of Haemobartonella felis in cats

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.

Effects of parasites coinfection with other pathogens on animal host: A literature review

A parasite-host relationship is complicated and largely remained poorly understood, especially when mixed infections involving pathogenic bacteria and viruses are present in the same host. It has been found that most parasites are able to manipulate the host's immune responses to evade or overcome its defense systems. Several mechanisms have been postulated that may explain this phenomenon in different animal species. Recent evidence suggests that coinfections involving many parasitic species alter the host's vulnerability to other microorganisms, hinder diagnostic accuracy, and may negatively impact vaccination by altering the host's immune responsiveness. The objective of this review was to provide a comprehensive summary of the current understanding of how parasites interact with other pathogens in different animal species. A better understanding of this complex relationship will aid in the improvement efforts of disease diagnosis, treatment, and control measures such as novel and effective vaccines and therapeutics for infectious diseases.

Two Clinical Cases of Feline Hemoplasmosis in Korea

Feline hemotropic mycoplasmosis (hemoplasmosis) is an infection of the red blood cells caused by the Mycoplasma haemofelis (Mhf), Candidatus Mycoplasma haemominutum (CMhm), and Candidatus Mycoplasma turicensis (CMt). The existence of Mhf, CMhm, and CMt has been demonstrated in feral cats in Korea using molecular methods, but no clinical cases have yet been reported. This study reports 2 clinical cases of hemotropic mycoplasmosis caused by CMhm and CMt in 2 anemic cats. The first case was a client-owned intact female domestic shorthair cat that presented with fever, pale mucous membranes, and normocytic normochromic non-regenerative anemia. Prior to referral, an immunosuppressive prednisolone dose was administered at the local veterinary clinic for 1 month. The cat was diagnosed with high-grade alimentary lymphoma. Organisms were found on the surface of the red blood cells on blood smear examination. The second case was of a rescued cat that presented with dehydration and fever. The cat had normocytic normochromic non-regenerative anemia. Necropsy revealed concurrent feline infectious peritonitis. Polymerase chain reaction assay targeting 16S rRNA revealed CMhm infection in case 1 and dual infection of CMhm and CMt in case 2. Normocytic normochromic non-regenerative anemia was observed in both cats before and during the management of the systemic inflammation. This is the first clinical case report in Korea to demonstrate CMhm and CMt infections in symptomatic cats.

DETECTION OF VECTOR-BORNE INFECTIONS IN LIONS AND TIGERS AT TWO ZOOS IN TENNESSEE AND OKLAHOMA, USA

Protozoal and bacterial vector-borne infections are frequently diagnosed in domestic felids. However, with the exception of Mycoplasma haemofelis and Cytauxzoon felis, their occurrence in managed nondomestic felids housed in the United States is largely unknown. Following a case in February 2020 of fulminant cytauxzoonosis in an African lion (Panthera leo), EDTA-whole blood samples were collected opportunistically from February 2020 through June 2020 from 34 adult tigers (Panthera tigris) and eight adult African lions from the same sanctuary in eastern Tennessee as well as 14 adult tigers from a zoo in southern Oklahoma. Samples were analyzed for Cytauxzoon felis, Bartonella spp., hemotropic Mycoplasma, Rickettsia spp., Anaplasma spp., Ehrlichia spp., Babesia spp., and Hepatozoon spp. DNA by PCR amplification. All animals were asymptomatic at the time of collection. None of the Oklahoma animals were positive for vector-borne organisms, but these pathogens were detected in tigers at the Tennessee facility, including Cytauxzoon felis (11.8%), "Candidatus Mycoplasma haemominutum" (5.9%), and Ehrlichia ewingii (2.9%). During the study period, two animals developed clinical signs of cytauxzoonosis and were assessed for vector-borne infections as part of their diagnostic evaluation. This study documents the presence of tick-borne diseases in managed nondomestic felids in the southeastern United States and underscores that ectoparasite control measures should be practiced to minimize exposure of carnivores in managed care.

Investigation of hemotropic Mycoplasma spp. genotypes in client-owned cats in Thailand

The genetic information for three feline hemoplasmas is limited in Southeast Asia. According to the limited genetic data, this study modified a nested-PCR method targeting the 16S rRNA gene by designing a novel primary forward degenerate primer. Two hundred and thirty-one archived DNA extracts from the blood of client-owned cats with a variety of diseases were used. The modified nested PCR detected feline hemoplasma DNA in 64 of 231 (27.7 %) samples. Sanger DNA sequencing, BLAST, and phylogenetic analyses revealed nine nucleotide sequences of Mycoplasma haemofelis (Mhf) (3.9 %, 9/231), fifty-three nucleotide sequences of Candidatus Mycoplasma haemominutum (CMhm) (22.94 %, 53/231) and two nucleotide sequences of Candidatus Mycoplasma turicensis (CMtc) (0.86 %, 2/231). The phylogenetic analysis demonstrated separate genotypes of 30 DNA sequences of Thai CMhm. In addition, this analysis elucidated distinct genotypes of CMhm in Thai fishing cats (Prionailurus viverrinus). The domestic cat and Thai fishing cat groups were the two major groups separating Thai CMhm genotypes based on the 16S rRNA. One CMhm sequence in Thai fishing cats was also present in domestic cat CMhm genotypes. This result suggests that transmission of CMhm between domestic cats and Thai fishing cats has likely occurred. One Mhf sequence had low genetic identity (82 % similarity). The phylogenetic analysis confirmed that this sequence was still very closely related to Mhf reference sequences. This Mhf-like genotype could be a candidate novel Mhf genotype. This new genetic information for feline hemotropic Mycoplasma provides valuable information for future feline-related clinical studies.

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."

Prevalence and risk factor analysis for feline haemoplasmas in cats from Northern Serbia, with molecular subtyping of feline immunodeficiency virus

Objectives

The objectives of this study were to estimate the prevalence of feline haemoplasma infections in Northern Serbia, identify potential risk factors and perform molecular subtyping of feline immunodeficiency virus (FIV).

Methods

PCR analysis for feline haemoplasmas was performed on surplus EDTA blood samples from 373 cats from the Belgrade region, Serbia. An ELISA was used to determine the prevalence of feline leukaemia virus (FeLV) and FIV; PCR was performed on a subpopulation of these cats. FIV subtyping was performed using PCR.

Results

Within this population, 64/373 cats (17.2%) were infected with one or more haemoplasma species. Mycoplasma haemofelis was detected in 20/373 cats (5.4%), ‘Candidatus Mycoplasma haemominutum’ in 47/373 cats (12.6%) and ‘Candidatus Mycoplasma turicensis’ in 23/373 cats (6.2%). Coinfections were observed in 21/373 cats (5.6%). Based on ELISA serological retroviral testing, 4/310 cats (1.3%) were infected with FeLV, whereas 78/331 (23.6%) were infected with FIV. Multivariable analysis identified significant associations between haemoplasma infection and anaemia (anaemic/non-anaemic, odds ratio [OR] 2.7, 95% confidence interval [CI] 1.04–7.1; P = 0.041]), male gender (male/female, OR 4.5, 95% CI 2.22–9.03; P <0.0005), outdoor access (yes/no, OR 5.2, 95% CI 2.28–11.92; P <0.0005), non-pedigree breed (non-pedigree/pedigree, OR 5.5, 95% CI 1.24–24.84; P = 0.025) and FIV seropositive status (positive/negative, OR 2.4, 95% CI 1.21–4.83; P = 0.012). PCR analysis of the FIV ELISA-positive samples revealed clade D as being the most prevalent.

Conclusions and relevance

All three known species of feline haemoplasma were detected, confirming their presence in Serbia; ‘Candidatus Mycoplasma haemominutum’ was the most prevalent. We found a high prevalence of FIV-infected cats and FIV clade D was most prevalent.

Infection by Mycoplasma spp., feline immunodeficiency virus and feline leukemia virus in cats from an area endemic for visceral leishmaniasis

Background

Visceral leishmaniasis (VL) has been increasingly recognized in cats living in areas endemic for the disease. Co-infection with Leishmania infantum and other infectious agents is well established in dogs. However, for cats, data on co-infections with L. infantum and other infectious agents are still sparse. The aim of this study was to identify the prevalence of vector-borne pathogens, Mycoplasma spp., feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) in cats from an area endemic for VL in southeastern Brazil.

Results

Of the 90 cats, eight (8.9%) were infected with Mycoplasma spp., five (5.5%) were FIV- positive and one (1.1%) was FeLV-positive. Co-infection with L. infantum and at least one other infectious agent was found in 9/50 (18.0%; CI: 8.6–31.4%) cats. In Group 1 (cats infected naturally by L. infantum), 4/50 (8.0%) cats were positive for FIV, 4/50 (8%) for Mycoplasma spp. and 1/50 (2.0%) was co-infected with FeLV and Mycoplasma spp. In Group 2 (cats non-infected with L. infantum), 2/40 (5.0%) cats were infected with Mycoplasma spp. and 1/40 (2.5%) was co-infected with FIV and Mycoplasma spp. All cats were negative for Ehrlichia spp., Babesia spp. and Anaplasma platys.

Conclusion

A low prevalence of co-infection in Leishmania-infected and non-infected cats was found. Co-infections with Leishmania and vector-borne diseases in cats are not common in this area endemic for VL in Brazil.

Haemoplasmosis in cats: European guidelines from the ABCD on prevention and management

OVERVIEW

Haemoplasmas are haemotropic bacteria that can induce anaemia in a wide range of mammalian species. Infection in cats: Mycoplasma haemofelis is the most pathogenic of the three main feline haemoplasma species known to infect cats. ' Candidatus Mycoplasma haemominutum' and ' Candidatus Mycoplasma turicensis' are less pathogenic but can result in disease in immunocompromised cats. Male, non-pedigree cats with outdoor access are more likely to be haemoplasma infected, and ' Candidatus M haemominutum' is more common in older cats. All three haemoplasma species can be carried asymptomatically. Transmission: The natural mode of transmission of haemoplasma infection is not known, but aggressive interactions and vectors are possibilities. Transmission by blood transfusion can occur and all blood donors should be screened for haemoplasma infection.

DIAGNOSIS AND TREATMENT

PCR assays are the preferred diagnostic method for haemoplasma infections. Treatment with doxycycline for 2-4 weeks is usually effective for M haemofelis-associated clinical disease (but this may not clear infection). Little information is currently available on the antibiotic responsiveness of ' Candidatus M haemominutum' and ' Candidatus M turicensis'.

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.

Detection and molecular characterization of feline hemoplasmas in wild felid species in Iran in the Middle East

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First description of feline hemoplasma and immunodeficiency virus in endangered Persian Leopard species in Iran, Middle East.

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No zoo-kept wild felids were infected.

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Close sequence identity with hemoplasma isolates from domestic and wild felids in Iran and other geographical origins.

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Both ‘Ca. M. haemominutum’ infected leopards were old and male and were not born nor residing in zoos.

Three feline hemoplasma species exist in felids: Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’, and ‘Candidatus Mycoplasma turicensis’.

The aims of the study were to determine the presence of, and molecularly characterize, any hemoplasmas in wild felids, including the endangered Persian leopard in Iran, the Middle East.

Blood samples were collected from 19 wild felids, including three Persian leopards. Using species-specific hemoplasma PCRs and ELISA serological testing for feline leukaemia virus and feline immunodeficiency virus (FIV), two Persian leopards were found to be infected with ‘Ca. M. haemominutum’ and were seropositive for FIV. Partial 16S rRNA gene sequences were generated for these ‘Ca. M. haemominutum’ species and subsequent phylogenetic analysis revealed 97.70% to 99.45% sequence identity with those found in domestic cats from Iran and other countries.

This study confirms the presence of ‘Ca. M. haemominutum’ and concurrent FIV antibody in wild felids in Iran. This represents the first report of hemoplasma in wild felids in the Middle East as well as the first report of infection in Persian leopards.

Risk factors of different hemoplasma species infections in cats

Background

Hemoplasma species (spp.) commonly cause infections in cats worldwide. However, data on risk factors for infections are limited. The aim of this study was to determine the prevalence of hemoplasma spp. infections in cats in Southern Germany and to assess risk factors associated with infection.

Results

DNA was extracted from blood samples of 479 cats presented to different veterinary hospitals for various reasons. DNA of feline hemoplasmas was amplified by use of a previously reported PCR assay. Direct sequencing was used to confirm all purified amplicons and compared to hemoplasma sequences reported in GenBank. Results were evaluated in relation to the age, sex, housing conditions, feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) status of the cats.

The overall hemoplasma prevalence rate was 9.4% (45/479; 95% CI: 7.08–12.36). ‘Candidatus Mycoplasma (M.) haemominutum’ (Mhm) DNA was amplified from 42 samples, M. haemofelis from 2, and M. haemocanis from 1 sample. There was a significantly higher risk of hemoplasma infection in cats from multi-cat households, in outdoor cats, as well as in cats with FIVinfection and in cats with abortive FeLV infection, but not in cats with progressive or regressive FeLV infection.

Conclusions

Mhm infection is common in cats in Southern Germany. Higher prevalence in multi-cat households and associations with FeLV infection likely reflect the potential for direct transmission amongst cats. Outdoor access, male gender, and FIV infection are additional risk factors that might relate to aggressive interactions and exposure to vectors.

Survival of Mycoplasma haemofelis and ‘Candidatus Mycoplasma haemominutum’ in blood of cats used for transfusions

Blood transfusions are commonly administered to cats; associated risks include the transmission of various infectious diseases including Mycoplasma haemofelis (Mhf) and ‘ Candidatus Mycoplasma haemominutum’ (Mhm). Blood transfusions in citrate-phosphate-dextrose-adenine (CPDA-1) solution are commonly administered immediately or stored for up to 1 month prior to administration. It is unknown whether Mhf or Mhm survive in this solution or temperature. The purpose of this study was to determine if Mhf or Mhm remain viable after storage in CPDA-1 for varying periods of time. The results provide evidence that transmission of hemoplasmas to naïve cats occurs after administration of infected feline blood that has been stored in CPDA-1 solution for 1 h (Mhf) and 1 week (Mhm). These findings support the recommendation that cats used as blood donors be screened for Mhf and Mhm infections by polymerase chain reaction (PCR) assay prior to use.

Prevalence of feline haemoplasma in cats in Denmark

BACKGROUND

Infections with the three feline haemotropic mycoplasmas Mycoplasma haemofelis, Candidatus Mycoplasma haemominutum and Candidatus Mycoplasma turicensis cause feline infectious anemia. The purpose of this study was to investigate the prevalence of carriage of feline haemoplasma in Danish cats in different age groups. The presence was detected by a conventional polymerase chain reaction (PCR) assay on blood samples as well as by real-time PCR (RT-PCR).

RESULTS

The study revealed a prevalence of 14.9% Candidatus Mycoplasma haemominutum positive cats and 1.5% Mycoplasma haemofelis positive cats. No cats were found positive for Candidatus Mycoplasma turicensis. The results showed a statistically significant higher prevalence in older (>8 years) cats compared to younger cats and a higher prevalence among domestic cats compared to purebred cats. As part of this study, we developed a cloning strategy to obtain Danish positive controls of haemoplasma 16S rRNA.

CONCLUSION

From convenience-sampled cats in Denmark, we found that 16.4% were carriers of feline haemotropic mycoplasmas. Haemoplasma was mostly found in older and domestic cats. The prevalence found in Denmark is similar to that found in several other European countries.

Assessment of the ability of Aedes species mosquitoes to transmit feline Mycoplasma haemofelis and ' Candidatus Mycoplasma haemominutum'

Objectives The objective of this study was to evaluate wild-caught mosquitoes for evidence of hemotropic Mycoplasma species DNA and to determine whether the feline hemoplasmas, Mycoplasma haemofelis (Mhf) and ' Candidatus Mycoplasma haemominutum' (Mhm), can be transmitted by Aedes aegypti mosquitoes in a laboratory setting. Methods Wild-caught mosquito pools (50 mosquitoes per pool, 84 pools) utilized in routine public health department disease surveillance programs were tested for hemotropic Mycoplasma species DNA using PCR with primers designed to amplify all known hemoplasmas. Additionally, mosquitoes were trapped in the vicinity of known feral cat colonies, pooled (50 mosquitoes per pool) and tested (84 pools). Purpose-bred cats housed in a research facility were infected with Mhf or Mhm and then colonized laboratory A aegypti were fed upon the bacteremic cats. After a 7 day incubation period, mosquitoes previously fed on infected cats were allowed to feed again on naive cats, which were monitored for bacteremia for 10 weeks. Results Mycoplasma wenyonii DNA was confirmed in one wild-caught mosquito pool by DNA sequencing. While 7% of cats tested in feral colonies were hemoplasma positive, none of the mosquitoes trapped near colonies were positive. Hemoplasma DNA was amplified from A aegypti by PCR immediately after the infectious blood meal, but DNA was not detected at 7 and 14 days after feeding. Although evidence for uptake of organisms existed, hemoplasma DNA was not amplified from the experimentally infested cats in the 10 week observation period. Conclusions and relevance While wild-caught mosquitoes contained hemoplasma DNA and laboratory reared A aegypti mosquitoes take up hemoplasmas during the blood meal, there was no evidence of biologic transmission in this model.

Evaluation of biochemical and haematological parameters and prevalence of selected pathogens in feral cats from urban and rural habitats in South Korea

OBJECTIVES

In this study, we evaluated the potential association between the habitat types of feral cats and the prevalence of selected infectious pathogens and health status based on a set of blood parameters.

METHODS

We live-trapped 72 feral cats from two different habitat types: an urban area (n = 48) and a rural agricultural area (n = 24). We compared blood values and the prevalence of feline immunodeficiency virus (FIV), feline leukaemia virus (FeLV) and haemotropic Mycoplasma infection in feral cats from the two contrasting habitats.

RESULTS

Significant differences were observed in several blood values (haematocrit, red blood cells, blood urea nitrogen, creatinine) depending on the habitat type and/or sex of the cat. Two individuals from the urban area were seropositive for FIV (3.0%), and eight (12.1%) were positive for FeLV infection (five from an urban habitat and three from a rural habitat). Haemoplasma infection was more common. Based on molecular analysis, 38 cats (54.3%) were positive for haemoplasma, with a significantly higher infection rate in cats from rural habitats (70.8%) compared with urban cats (47.8%).

CONCLUSIONS AND RELEVANCE

Our study recorded haematological and serum biochemical values, and prevalence of selected pathogens in feral cat populations from two different habitat types. A subset of important laboratory parameters from rural cats showed values under or above the corresponding reference intervals for healthy domestic cats, suggesting potential differences in the health status of feral cats depending on the habitat type. Our findings provide information about the association between 1) blood values (haematological and serum biochemistry parameters) and 2) prevalence of selected pathogen infections and different habitat types; this may be important for veterinarians who work with feral and/or stray cats and for overall cat welfare management.

Molecular detection of haemotropic Mycoplasma species in urban and rural cats from Portugal

Objectives

The aim of the present study was to evaluate the prevalence of haemoplasma infection in cats in Portugal and to assess risk factors for infection.

Methods

Real-time polymerase chain reaction techniques were used to assess 236 urban and rural cats from central and southern Portugal.

Results

The overall prevalence of haemoplasma in the target population was 27.1% (64/236), with individual species’ prevalences as follows: 17.8% (42/236) ‘ Candidatus Mycoplasma haemominutum’ (CMhm), 14.4% (34/236) Mycoplasma haemofelis (Mhf) and only 5.9% (14/236) ‘ Candidatus Mycoplasma turicensis’ (CMt). Multiple infections were detected in 8.1% (19/236) of the samples, with triple and double infections with Mhf and CMhm being most commonly detected (5.9% [14/236] of cats). Haemoplasma infection was significantly higher in shelter cats ( P = 0.015) than in cats with other lifestyles (eg, free-roaming/house pet/blood donors). Haemoplasma prevalence was also higher in cats with feline immunodeficiency virus infection (FIV; P = 0.011). Although sex was not significantly associated with haemoplasma infection ( P = 0.050), CMt was predominantly found in males ( P = 0.032). Also, the presence of haemoplasma multiple infections was statistically associated with being in a shelter ( P = 0.021), male ( P = 0.057) and with FIV co-infection ( P = 0.004). No evidence of an association between haemoplasma infection and geographical location, age or feline leukaemia virus co-infection was found.

Conclusions and relevance

The results obtained in our study are consistent with the documented worldwide prevalence of feline haemoplasma infections, suggesting that the three main feline haemoplasma species are common in Portugal.

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.

First evidence of hemoplasma infection in free-ranging Namibian cheetahs (Acinonyx jubatus)

Infections with feline hemotropic mycoplasmas (hemoplasmas) have been documented in domestic cats and free-ranging feline species with high prevalences in Iberian lynxes (Lynx pardinus), Eurasian lynxes (Lynx lynx), European wildcats (Felis silvestris silvestris), African lions (Panthera leo) in Tanzania and domestic cats in South Africa. The prevalence of hemoplasmas has not yet been investigated in free-ranging felids in southern Africa. In this study we screened 73 blood samples from 61 cheetahs in central Namibia for the presence of hemoplasmas using quantitative real-time PCR. One of the cheetahs tested PCR-positive. Phylogenetic analysis based on partial sequencing of the 16S rRNA and RNAse P genes revealed that the isolate belongs to the Mycoplasma haemofelis/haemocanis group. This is the first molecular evidence of a hemoplasma infection in a free-ranging cheetah.

Prevalence and risk factor analysis of bovine hemoplasma infection by direct PCR in Eastern Hokkaido, Japan

The prevalence and risk factors of 2 bovine hemoplasma species-Mycoplasma wenyonii (Mw) and "Candidatus Mycoplasma haemobos" (CMh)-were examined by direct PCR using whole blood samples collected from 343 cattle in Eastern Hokkaido, Japan. The sensitivity of the direct PCR assay was 10-fold higher than the standard PCR assay, detecting 5 copies of bovine hemoplasma DNA per reaction. An epidemiological survey of sampling location, living conditions, age and bovine leukemia virus antibody was performed to assess infection risk factors. The prevalence rates were 38.5% for Mw and 39.1% for CMh, respectively, with an overall prevalence rate of 64.7% for all bovine hemoplasma infections. Significant differences were found in sampling location, living conditions and age. Compared with pastured cattle, farmed cattle were significantly more susceptible to infection with total hemoplasma species (P<0.001), and were particularly susceptible to CMh (P<0.001). Cattle that were 1-3 years of age were more susceptible to infection with hemoplasma compared with other age groups. Bovine leukemia virus infection status was not significantly associated with hemoplasma infections. Blood examination revealed significantly lower RBC, Hb, and PCV levels, and a higher MCV in infected cattle than in noninfected cattle.

Quantification of the humoral immune response and hemoplasma blood and tissue loads in cats coinfected with 'Candidatus Mycoplasma haemominutum' and feline leukemia virus

'Candidatus Mycoplasma haemominutum' (CMhm) is a hemotropic mycoplasma (aka hemoplasma) of domestic cats and wild felids. In a transmission study, we exposed eight specified pathogen-free cats to blood from Iberian lynxes (Lynx pardinus) infected with CMhm. The cats were coinfected with feline leukemia virus (FeLV) from an Iberian lynx or with a prototype FeLV. The goal of the present study was to quantify the humoral immune response to CMhm and to identify potential target tissues and sequestration sites. Antibodies were measured by a recombinant antigen-based enzyme-linked immunosorbent assay, and blood and tissue loads were quantified using real-time PCR. Seven out of eight cats became CMhm-infected; all of these cats seroconverted between 3 and 13 weeks after inoculation. Antibody levels correlated with the CMhm blood loads. The peak CMhm blood loads were inversely correlated with the incubation period. PCR-positive results were found in all 24 tissues tested but not for all samples. Although all tissues were PCR-positive in one cat euthanized ten weeks after infection, many tissues tested negative in six cats euthanized at week 20 after infection. In several cats, the spleen, lung, liver, heart and aorta contained more copies than expected given the tissue's blood supply, but most tissues contained fewer copies than expected. In conclusion, this is the first study to quantify the humoral immune response and tissue loads in CMhm-FeLV-coinfected cats. The tissue loads appeared to correlate with the duration of infection and with the blood loads, but no evidence of significant CMhm tissue sequestration was found.

Genome of Mycoplasma haemofelis, unraveling its strategies for survival and persistence

Mycoplasma haemofelis is a mycoplasmal pathogen (hemoplasma) that attaches to the host's erythrocytes. Distributed worldwide, it has a significant impact on the health of cats causing acute disease and, despite treatment, establishing chronic infection. It might also have a role as a zoonotic agent, especially in immunocompromised patients. Whole genome sequencing and analyses of M. haemofelis strain Ohio2 was undertaken as a step toward understanding its survival and persistence. Metabolic pathways are reduced, relying on the host to supply many of the nutrients and metabolites needed for survival. M. haemofelis must import glucose for ATP generation and ribose derivates for RNA/DNA synthesis. Hypoxanthine, adenine, guanine, uracil and CMP are scavenged from the environment to support purine and pyrimidine synthesis. In addition, nicotinamide, amino acids and any vitamins needed for growth, must be acquired from its environment. The core proteome of M. haemofelis contains an abundance of paralogous gene families, corresponding to 70.6% of all the CDSs. This "paralog pool" is a rich source of different antigenic epitopes that can be varied to elude the host's immune system and establish chronic infection. M. haemofelis also appears to be capable of phase variation, which is particularly relevant to the cyclic bacteremia and persistence, characteristics of the infection in the cat. The data generated herein should be of great use for understanding the mechanisms of M. haemofelis infection. Further, it will provide new insights into its pathogenicity and clues needed to formulate media to support the in vitro cultivation of M. haemofelis.

Identification, bioinformatics analyses, and expression of immunoreactive antigens of Mycoplasma haemofelis

Mycoplasma haemofelis infection frequently causes anemia in cats. Despite an intense immune response and/or antibiotic treatment, cats often remain asymptomatic carriers following infection. Our hypothesis is that detection of antibodies to M. haemofelis is a sensitive approach for identifying infected cats, particularly carriers. To date, no immunoassay has been developed. This is due largely to the inability to culture M. haemofelis in vitro; hence, a source of antigen is not readily available. The objective of this study was to identify, express, and purify immunogenic proteins of M. haemofelis. To accomplish this, two whole-genomic expression libraries were created in the Lambda ZapII vector and immunoscreened with preimmune plasma, plasma from specific-pathogen-free cats, and pooled acute- and convalescent-phase plasma from experimentally infected cats. The inserts from 21 immunoreactive clones were sequenced, resulting in the identification of 60 genes coding for putative proteins necessary for diverse cellular functions, along with several novel genes of M. haemofelis. Fragments of selected genes based on bioinformatic analyses were PCR amplified, cloned into a high-level protein expression system, and subsequently expressed in Escherichia coli as a His(6)-fusion protein. The recombinant fusion proteins of M. haemofelis were purified and evaluated as an antigen in a Western blot to verify the findings of previous immunoscreening. Together with bioinformatics analyses of individual genes, this approach provided several putative candidate antigens. Five antigens of M. haemofelis were reactive by Western blotting against the immune plasma and negative against nonimmune plasma; these antigens might be useful serologic or even vaccine targets.

Feline leukemia virus outbreak in the critically endangered Iberian lynx (Lynx pardinus): high-throughput sequencing of envelope variable region A and experimental transmission

The Iberian lynx is the most endangered felid species. During winter/spring 2006/7, a feline leukemia virus (FeLV) outbreak of unexpected virulence killed about 2/3 of the infected Iberian lynxes. All FeLV-positive animals were co-infected with feline hemoplasmas. To further characterize the Iberian lynx FeLV strain and evaluate its potential virulence, the FeLV envelope gene variable region A (VRA) mutant spectrum was analyzed using the Roche 454 sequencing technology, and an in vivo transmission study of lynx blood to specified-pathogen-free cats was performed. VRA mutations indicated weak apolipoprotein B mRNA editing enzyme and catalytic polypeptide-like cytidine deaminase (APOBEC) restriction of FeLV replication, and variants characteristic of aggressive FeLV strains, such as FeLV-C or FeLV-A/61C, were not detected. Cats exposed to FeLV/Candidatus Mycoplasma haemominutum-positive lynx blood did not show a particularly severe outcome of infection. The results underscore the special susceptibility of Iberian lynxes to infectious diseases.

Haemotropic mycoplasmas: what's their real significance in cats?

Practical relevance

The feline haemotropic mycoplasmas (‘haemoplasmas') are a group of bacteria that can induce haemolytic anaemia in cats. Mycoplasma haemofelis is the most pathogenic of the species; ‘Candidatus Mycoplasma haemominutum’ and ‘Candidatus Mycoplasma turicensis’ are less pathogenic. The natural route of transmission of feline haemoplasma infection has not been confirmed, but fleas are implicated. When disease results, common clinical signs are pallor, lethargy, anorexia, weight loss, depression, dehydration and pyrexia. Treatment with tetracyclines or fluoroquinolones is usually effective at resolving clinical disease, but clearance of infection may not result.

Global importance

The feline haemoplasmas are found worldwide, although prevalence varies geographically.

Patient group

Older male non-pedigree cats are believed to be at increased risk of haemoplasma infection, although younger cats are possibly more likely to show clinical disease associated with M haemofelis.

Clinical challenges

The significance of feline haemoplasma infection is difficult to determine due to the existence of asymptomatic carrier cats and the variable pathogenicity of the haemoplasma species. Polymerase chain reaction (PCR) results should be interpreted in the light of the patient's clinical signs and haematological findings, infecting haemoplasma species and level of haemoplasma DNA present in the blood. Trial antibiotic treatment for haemoplasmosis may be warranted in suspected cases while awaiting PCR results.

Evidence base

Aspects of feline haemoplasmosis, particularly risk factors, pathogenesis, diagnostic methods and treatment, have been the focus of much recent research. This article draws on the current evidence base with a view to helping clinicians diagnose and manage cases more effectively.

An epidemiological survey of feline hemoplasma infection in Japan

Hemoplasma (hemotropic mycoplasma) often causes hemolytic anemia in infected cats, especially those with immune suppression. An updated nationwide epidemiological survey of feline hemoplasmosis was conducted in Japan. Blood samples were collected from 1,770 outdoor-accessing cats from March to October 2008. The infections were molecularly detected by PCR analyses, which are able to distinguish Mycoplasma haemofelis (Mhf), `Candidatus M. haemominutum' (CMhm), and `Candidatus M. turicensis' (CMt) infections. Of the 1,770 cats, 468 cases (26.4%) revealed a single- or co-infection of feline hemoplasmas [Mhf alone, 42 cases (2.4%); CMhm alone, 280 cases (15.8%); CMt alone, 48 cases (2.7%); Mhf+CMhm, 28 cases (1.6%); Mhf+CMt, 6 cases (0.3%); CMhm+CMt, 50 cases (2.8%); Mhf+CMhm+CMt, 14 cases (0.8%)]. In addition, male gender, middle to old age, history of fight wounds, and feline immunodeficiency virus infection were shown to be risk factors for hemoplasma infection. Close attention must be paid to the acute onset of disease in feline practice because a prevalence of hemoplasma infection was detected even in clinically healthy cats.

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.

Feline hemotropic mycoplasmas

OBJECTIVE

To describe the current understanding of the etiology, pathogenesis, diagnosis, and treatment of feline hemotropic mycoplasmosis (feline infectious anemia).

DATA SOURCES

Manuscripts published on hemotropic mycoplasmosis in cats and other animal species, based on a search of PubMed using the search terms 'hemoplasmas,''haemoplasmas,''hemotropic,''haemotropic,' and 'Haemobartonella,' as well as references published within manuscripts accessed.

HUMAN DATA SYNTHESIS

Although hemotropic bacteria such as Bartonella bacilliformis have been recognized in humans for over 100 years, it has only been in recent years that some of these have been identified as hemotropic mycoplasmas.

VETERINARY DATA SYNTHESIS

Three species of hemotropic mycoplasmas have been documented in cats worldwide, Mycoplasma haemofelis, 'Candidatus Mycoplasma turicensis,' and 'Candidatus Mycoplasma haemominutum.' These organisms were previously known as Haemobartonella felis, but are now known to be mycoplasmas. M. haemofelis is the most pathogenic species, and causes anemia in immunocompetent cats. Although 'Candidatus Mycoplasma turicensis' and 'Candidatus Mycoplasma haemominutum' may be more capable of causing anemia in immunosuppressed cats, their pathogenicity remains controversial. Assays based on polymerase chain reaction technology are the most sensitive and specific diagnostic tests available for these organisms, because they remain uncultivable in the laboratory setting. Blood smears are unreliable for diagnosis of hemoplasmosis because of their lack of sensitivity and specificity.

CONCLUSIONS

Cats presenting to emergency/critical care specialists with hemolytic anemia should be tested using polymerase chain reaction assays for hemotropic mycoplasmas before instituting antimicrobial therapy. Positive test results for M. haemofelis suggest involvement of this organism in hemolytic anemia. Other differential diagnoses for hemolytic anemia should be considered in cats testing positive for 'Candidatus Mycoplasma turicensis' and 'Candidatus Mycoplasma haemominutum,' because the presence of these organisms is not always associated with anemia. Blood from infected cats should be handled with care because of the potential zoonotic nature of this infection.

Description of outcomes of experimental infection with feline haemoplasmas: copy numbers, haematology, Coombs' testing and blood glucose concentrations

The aim of this study was to compare blood copy, haematological and glucose values between cats experimentally infected with either Mycoplasma haemofelis (Group HF: 10 cats), 'Candidatus M. haemominutum' (Group HM: 3 cats) or 'Candidatus M. turicensis' (Group TU: 3 cats). Blood samples were collected regularly up to 85 days post-infection (DPI) for haemoplasma real-time quantitative PCR, haematology, Coombs' testing and blood glucose measurement. Statistical analysis was performed using a general linear model (ANOVA) appropriate for a repeated measures experiment with significance set as P<0.05. Cats in Group TU had significantly lower blood copy numbers than cats in Group HF (P<0.001) and HM (P<0.001). All Group HF cats developed anaemia (often severe), macrocytosis and evidence of erythrocyte-bound antibodies whereas Groups HM and TU cats did not. Group HF had significantly lower PCVs, haemoglobin concentrations and red blood cell counts, and significantly higher mean cell volumes, than Groups HM and TU. In Group HF, erythrocyte-bound antibodies reactive at 4 degrees C (both IgM and IgG) appeared between 8 and 22 DPI and persisted for two to four weeks, whereas those reactive at 37 degrees C (primarily IgG) appeared between 22 and 29 DPI and persisted for one to five weeks. In most cats antibodies appeared after the fall in haemoglobin started. Although Group TU had significantly lower glucose concentrations than Groups HF (P=0.006) and HM (P=0.027), mean blood glucose concentrations remained within the reference range in all groups. This study demonstrates that M. haemofelis infection, in contrast to 'Candidatus M. haemominutum' and 'Candidatus M. turicensis' infection, can result in a severe macrocytic anaemia and the development of cold and warm reactive erythrocyte-bound antibodies.

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.

First molecular identification of 'Candidatus mycoplasma haemominutum' from a cat with fatal haemolytic anaemia in Hungary

Although haemobartonellosis was previously reported in Hungary, until now the diagnosis (based on morphological identification in blood smears) has only been suggestive of the occurrence of the large species, recently reclassified as Mycoplasma haemofelis. However, in July 2007 a cat was presented at a small animal clinic with severe haemolytic anaemia, icterus and haemoglobinuria. While biochemical parameters were within the reference range, the cat had leukocytosis and rapidly decreasing haematocrit values, and eventually died 7 days after the sudden onset of aggravating clinical signs. From blood samples of the cat 'Candidatus Mycoplasma haemominutum' was identified by molecular methods, according to its 100% 16S rRNA gene sequence homology with two Swiss isolates and one isolate from the UK. The rapid termination of the disease and the high pathogenicity of the causative agent observed in this case are unusual, taking into account that PCR results were negative for immunosuppressive viruses. This is the first record of this feline haemoplasma species in Hungary.

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.

The prevalence of three species of feline haemoplasmas in samples submitted to a diagnostics service as determined by three novel real-time duplex PCR assays

Three distinct species of feline haemoplasmas are recognised: Mycoplasma haemofelis (Mhf), Candidatus Mycoplasma haemominutum (CMhm) and Candidatus Mycoplasma turicensis (CMt). These species differ in pathogenicity as Mhf and CMt can be associated with anaemia whereas CMhm usually results in few clinical signs. The purpose of this study was to develop quantitative real-time PCR assays for the detection of all three feline haemoplasma species combined with an endogenous internal control and to determine the prevalence of infection, using these assays, in 1592 EDTA blood samples submitted to Langford Veterinary Diagnostics, University of Bristol for haemoplasma testing. Primers and TaqMan probes were designed against published 16S rDNA sequences. These assays were combined with a feline 28S rDNA-specific assay to produce three duplex assays. The assays detected 1-10 copies of a sequence-specific plasmid per PCR. None of the assays showed cross-reactivity with 10(6) copies of a sequence-specific plasmid from the non-target haemoplasma species. Real-time PCR was performed on all samples using the three assays. Seven samples were negative for feline 28S rDNA and were excluded from the study. Of the remaining 1585 samples, 45 (2.8%), 177 (11.2%) and 27 (1.7%) samples were positive for Mhf, CMhm and CMt, respectively, including 11 Mhf/CMhm, 10 CMhm/CMt and two Mhf/CMt dual infections and two triple infections. The results of this study demonstrate the utility of these new duplex PCR assays for the detection of haemoplasma infections. CMhm was the most common infection and CMt infections were often associated with co-infection with other haemoplasma species, especially CMhm.

Prevalence and risk factors for hemoplasmas in domestic cats naturally infected with feline immunodeficiency virus and/or feline leukemia virus in Rio de Janeiro--Brazil

The aim of this study was to determine the prevalence and risk factors for Mycoplasma haemofelis (Mhf) and 'Candidatus Mycoplasma haemominutum' (Mhm) infections in domestic cats tested for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) with a commercial enzyme-linked immunosorbent assay (ELISA) kit. Based on serological testing, cats were grouped as i) FIV-positive (n=25); ii) FeLV-positive (n=39); iii) FIV/FeLV-positive (n=8); and iv) FIV/FeLV-negative (n=77). Complete blood counts were followed by DNA extraction, species-specific polymerase chain reaction (16S rRNA gene) for Mhf and Mhm and Southern blotting for all animals. Mhf DNA was found in 4.0, 2.6, 12.5 and 7.8% of the cats from groups i, ii, iii and iv, respectively, while 32, 5.1, 50 and 5.2% of these animals had an Mhm infection. Cats with FIV (OR=4.25, P=0.009) and both FIV and FeLV (OR=7.56, P=0.014) were at greater risk of being hemoplasma infected than retroviral-negative cats, mainly due to Mhm infection (OR=8.59, P=0.001 and OR=18.25, P=0.001, respectively). Among pure-breed cats, FIV-positive status was associated with hemoplasma infection (OR 45.0, P=0.001).

“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.

Worldwide occurrence of feline hemoplasma infections in wild felid species

While hemoplasma infections in domestic cats are well studied, almost no information is available on their occurrence in wild felids. The aims of the present study were to investigate wild felid species as possible reservoirs of feline hemoplasmas and the molecular characterization of the hemoplasma isolates. Blood samples from the following 257 wild felids were analyzed: 35 Iberian lynxes from Spain, 36 Eurasian lynxes from Switzerland, 31 European wildcats from France, 45 lions from Tanzania, and 110 Brazilian wild felids, including 12 wild felid species kept in zoos and one free-ranging ocelot. Using real-time PCR, feline hemoplasmas were detected in samples of the following species: Iberian lynx, Eurasian lynx, European wildcat, lion, puma, oncilla, Geoffroy's cat, margay, and ocelot. "Candidatus Mycoplasma haemominutum" was the most common feline hemoplasma in Iberian lynxes, Eurasian lynxes, Serengeti lions, and Brazilian wild felids, whereas "Candidatus Mycoplasma turicensis" was the most prevalent in European wildcats; hemoplasma coinfections were frequently observed. Hemoplasma infection was associated with species and free-ranging status of the felids in all animals and with feline leukemia virus provirus-positive status in European wildcats. Phylogenetic analyses of the 16S rRNA and the partial RNase P gene revealed that most hemoplasma isolates exhibit high sequence identities to domestic cat-derived isolates, although some isolates form different subclusters within the phylogenetic tree. In conclusion, 9 out of 15 wild felid species from three different continents were found to be infected with feline hemoplasmas. The effect of feline hemoplasma infections on wild felid populations needs to be further investigated.

Phylogenetic analysis of "Candidatus Mycoplasma turicensis" isolates from pet cats in the United Kingdom, Australia, and South Africa, with analysis of risk factors for infection

Two hemotropic mycoplasmas have been recognized in cats, Mycoplasma haemofelis and "Candidatus Mycoplasma haemominutum." We recently described a third feline hemoplasma species, designated "Candidatus Mycoplasma turicensis," in a Swiss cat with hemolytic anemia. This isolate induced anemia after experimental transmission to two specific-pathogen-free cats and analysis of the 16S rRNA gene revealed its close relationship to rodent hemotropic mycoplasmas. The agent was recently shown to be prevalent in Swiss pet cats. We sought to investigate the presence and clinical importance of "Candidatus Mycoplasma turicensis" infection in pet cats outside of Switzerland and to perform the molecular characterization of isolates from different countries. A "Candidatus Mycoplasma turicensis"-specific real-time PCR assay was applied to blood samples from 426 United Kingdom (UK), 147 Australian, and 69 South African pet cats. The 16S rRNA genes of isolates from different countries were sequenced and signalment and laboratory data for the cats were evaluated for associations with "Candidatus Mycoplasma turicensis" infection. Infections were detected in samples from UK, Australian, and South African pet cats. Infection was associated with the male gender, and "Candidatus Mycoplasma haemominutum" and M. haemofelis coinfection. Coinfected cats exhibited significantly lower packed cell volume (PCV) values than uninfected cats. Phylogenetic analyses revealed that some Australian and South African "Candidatus Mycoplasma turicensis" isolates branched away from the remaining isolates. In summary, "Candidatus Mycoplasma turicensis" infection in pet cats exists over a wide geographical area and significantly decreased PCV values are observed in cats coinfected with other feline hemoplasmas.

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 of Mycoplasma haemofelis, 'Candidatus Mycoplasma haemominutum', Bartonella species, Ehrlichia species, and Anaplasma phagocytophilum DNA in the blood of cats with anemia

Hemoplasmas are known causes of anemia in some cats and some Bartonella species have been associated with anemia in people and in dogs. In this retrospective study, we used polymerase chain reaction (PCR) assays to determine the prevalence rates of Mycoplasma haemofelis, ‘Candidatus M haemominutum’, A phagocytophilum, Ehrlichia species, and Bartonella species DNA in the blood of cats with anemia and a control group of healthy cats. DNA of the organisms was amplified from 22 of 89 cats with anemia (24.7%) and 20 of 87 healthy cats (23.0%). DNA of a hemoplasma was amplified from 18 of 89 cats with anemia (20.2%) and 13 of 87 healthy cats (14.9%); DNA of a Bartonella species was amplified from five of 89 cats with anemia (5.6%) and seven of 87 healthy cats (8.0%). There were no statistically significant differences detected between groups.

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-naïve 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-naïve 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-naïve 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 naïve 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.

Prevalence, risk factor analysis, and follow-up of infections caused by three feline hemoplasma species in cats in Switzerland

Recently, a third novel feline hemotropic Mycoplasma sp. (aka hemoplasma), "Candidatus Mycoplasma turicensis," in a cat with hemolytic anemia has been described. This is the first study to investigate the prevalence, clinical manifestations, and risk factors for all three feline hemoplasma infections in a sample of 713 healthy and ill Swiss cats using newly designed quantitative real-time PCR assays. "Candidatus Mycoplasma haemominutum" infection was detected in 7.0% and 8.7% and Mycoplasma haemofelis was detected in 2.3% and 0.2% of healthy and ill cats, respectively. "Candidatus Mycoplasma turicensis" was only detected in six ill cats (1.1%); three of them were coinfected with "Candidatus Mycoplasma haemominutum." The 16S rRNA gene sequence of 12 Swiss hemoplasma isolates revealed >98% similarity with previously published sequences. Hemoplasma infection was associated with male gender, outdoor access, and old age but not with retrovirus infection and was more frequent in certain areas of Switzerland. "Candidatus Mycoplasma haemominutum"-infected ill cats were more frequently diagnosed with renal insufficiency and exhibited higher renal blood parameters than uninfected ill cats. No correlation between hemoplasma load and packed cell volume was found, although several hemoplasma-infected cats, some coinfected with feline immunodeficiency virus or feline leukemia virus, showed hemolytic anemia. High M. haemofelis loads (>9 x 10(5) copies/ml blood) seem to lead to anemia in acutely infected cats but not in recovered long-term carriers. A repeated evaluation of 17 cats documented that the infection was acquired in one case by blood transfusion and that there were important differences among species regarding whether or not antibiotic administration led to the resolution of bacteremia.

Effect of chronic feline immunodeficiency infection, and efficacy of marbofloxacin treatment, on 'Candidatus Mycoplasma haemominutum' infection

The purpose of this study was to investigate the effect of chronic feline immunodeficiency virus (FIV) infection, and efficacy of marbofloxacin treatment, on 'Candidatus Mycoplasma haemominutum' infection. Six cats chronically infected with FIV-Glasgow8 (group A) and six FIV-free cats (group B) were infected with 'Candidatus M. haemominutum' on day 0 by intravenous inoculation of blood. From day 0 to 105 post-infection (pi), blood samples were collected for 'Candidatus M. haemominutum' and FIV provirus quantitative real-time polymerase chain reaction (PCR) and haematological examination. Three of the six cats in each of the groups were randomly selected to receive marbofloxacin treatment (2mg/kg PO SID) from day 49 to day 76 pi, with the remaining cats being untreated controls. Maximum 'Candidatus M. haemominutum' copy number was reached around day 30 pi. No overt cycling or marked variation in copy number was observed. No significant effect of FIV infection on 'Candidatus M. haemominutum' copy number kinetics or anaemia indices was found. No correlation was found between FIV provirus copy number and 'Candidatus M. haemominutum' copy number or haematological variables. Although marbofloxacin treatment was associated with a significant decrease in 'Candidatus M. haemominutum' copy number, the copy number plateaued during treatment, with no negative PCR results. Additionally, after termination of marbofloxacin treatment the copy numbers of the treated cats increased to reach levels similar to those of the untreated cats within 7-10 days. This study documents, for the first time, the infection kinetics and antibiotic responsiveness of 'Candidatus M. haemominutum' infection.