A case report of Mycoplasma wenyonii associated immune-mediated haemolytic anaemia in a dairy cow

Apparent prevalence of hemotropic mycoplasma in dairy calves and replacement heifers on Michigan farms

The bovine hemoplasmas include Mycoplasma wenyonii and Candidatus Mycoplasma haemobos, which are increasingly recognized as infecting cattle throughout the world. Infection with hemotropic mycoplasma has been reported to be widespread in mature dairy cows, but little is known about its prevalence in calves and heifers. The objective of this study was to investigate the prevalence and dynamics of infection with M. wenyonii and C. M. haemobos in calves and replacement heifers on Michigan dairy farms and assess the potential associations between infection status and hematological values. The study was designed as a prospective cross-sectional study with a longitudinal component. A convenience sample of 11 farms agreed to participate and were visited twice between March and September 2022. During the first farm visit, researchers collected blood samples from up to 94 animals per farm distributed among newborn and preweaning calves (n ≤ 31), weaned calves (n = 21), pre-breeding heifers (n = 21), and pregnant heifers (n = 21). During the first visit, blood samples (n = 174) were also collected from a convenience sample of mature cows to confirm the herd infection status. The same calves and heifers were sampled again ∼95 d (±3.0) later. During the first visit, blood samples were collected from 797 calves and replacement heifers, whereas 675 samples were collected during the second visit due to the inability to locate some animals. Detection of M. wenyonii and C. M. haemobos was based on results of real-time PCR. The hematocrit was determined using microcentrifugation, and the concentration of leukocytes using an automated cell counter. In all herds, most mature cows that were sampled tested positive for infection. The within-herd apparent prevalence of hemoplasma in calves and replacement heifers was 100% for both M. wenyonii and C. M. haemobos. The apparent prevalence of hemoplasma in youngstock was associated with age. In calves that were 1 to 6 mo old, the prevalence of infection was 6% to 8% but sharply increased to 31% by 8 mo of age. In older animals, the prevalence remained high, and was almost 100% in animals greater than 17 mo of age. Based on calves and heifers sampled twice, the cumulative incidence varied widely among herds, ranging from 3.7% to 96.0%, and increased with the age of the animals. We found no difference in hematocrit or number of lymphocytes, monocytes, neutrophils, or total leukocytes based on infection status. The number of eosinophils was greater in infected animals. This is the first study to report the prevalence of hemoplasmas in calves and replacement heifers in the United States. It indicates that young calves can be infected with hemoplasmas, but the rate of infection is low. The likelihood of infection increases as animals age, with a notable rise in the proportion of infected heifers occurring by 8 mo old, and the prevalence eventually reaching nearly 100% in older animals. Once infected, heifers appear to remain chronic carriers. Hemoplasma infection alone does not usually lead to the development of clinical signs, and most of the animals remain apparently healthy.

Graduate Student Literature Review: Hemotropic mycoplasmas in cattle

The objective of this narrative literature review is to better understand bovine hemoplasmosis, an emerging disease that threatens dairy animal health. Several species of hemotropic mycoplasma are known to infect both animals and humans, and Mycoplasma wenyonii and Candidatus Mycoplasma haemobos are the species that infect red blood cells of cattle. These microorganisms are associated with clinical signs in dairy cattle, but the effects of infection on health and productivity of dairy cows are poorly understood. In this paper, we review information about the epidemiology of bovine hemoplasmosis in different countries, including clinical signs associated with hemoplasmosis in cattle, methods of diagnosis, treatment, possible routes of transmission, risk factors for infection, and disease progression. Although hemoplasmas have been reported to infect cattle in many countries, and methods used to detect these organisms have improved, numerous gaps in knowledge were identified. The pathogenesis of the disease and potential effect on animal health and productivity remain unclear. With this review, we seek to contribute to the understanding of hemoplasmosis in cattle and provide insights for further research to improve disease management strategies and overall animal health in the dairy industry.

Unmapped short reads from whole-genome sequencing indicate potential infectious pathogens in german black Pied cattle

When resequencing animal genomes, some short reads cannot be mapped to the reference genome and are usually discarded. In this study, unmapped reads from 302 German Black Pied cattle were analyzed to identify potential pathogenic DNA. These unmapped reads were assembled and blasted against NCBI's database to identify bacterial and viral sequences. The results provided evidence for the presence of pathogens. We found sequences of Bovine parvovirus 3 and Mycoplasma species. These findings emphasize the information content of unmapped reads for gaining insight into bacterial and viral infections, which is important for veterinarians and epidemiologists.

Identification of Mycoplasma species and related organisms from ruminants in England and Wales during 2005-2019

Background

Mycoplasma species have been associated with economically important diseases affecting ruminants worldwide and include contagious bovine pleuropneumonia (CBPP), contagious caprine pleuropneumonia (CCPP) and contagious agalactia, listed by the World Organisation for Animal Health (OIE). The Mycoplasma Team at the Animal and Plant Health Agency provides an identification service for Mycoplasma and Ureaplasma species of veterinary importance to the United Kingdom (UK), supporting the detection of new and emerging pathogens, as well as contributing to the surveillance of endemic, and the OIE listed diseases exotic to the UK. Mycoplasma and other Mollicutes species were identified from diagnostic samples from farmed ruminants in England and Wales using a combination of culture and 16S rRNA gene-based PCR-denaturing gradient gel electrophoresis, submitted between 2005 and 2019.

Results

A total of 5578 mollicutes identifications, which include mycoplasmas and the related acholeoplasmas and ureaplasmas, were made from farmed ruminant animals during the study period. Throughout the study period, the pathogen Mycoplasma bovis was consistently the most frequently identified species, accounting for 1411 (32%) of 4447 molecular identifications in cattle, primarily detected in the lungs of pneumonic calves, followed by joints and milk of cattle showing signs of arthritis and mastitis, respectively. M. bovirhinis, M. alkalescens, M. dispar, M. arginini and Ureaplasma diversum, were also common. Mixed species, principally M. bovis with M. alkalescens, M. arginini or M. bovirhinis were also prevalent, particularly from respiratory samples. The non-cultivable blood-borne haemoplasmas Candidatus ‘Mycoplasma haemobos’ and Mycoplasma wenyonii were identified from cattle, with the latter species most often associated with milk-drop. M. ovipneumoniae was the predominant species identified from sheep and goats experiencing respiratory disease, while M. conjunctivae preponderated in ocular samples. The UK remains free of the ruminant mycoplasmas listed by OIE.

Conclusions

The continued high prevalence of M. bovis identifications confirms its ongoing dominance and importance as a significant pathogen of cattle in England and Wales, particularly in association with respiratory disease. M. ovipneumoniae has seen a general increase in prevalence in recent years, notably in coughing lambs and should therefore be considered as a primary differential diagnosis of respiratory disease in small ruminants.

Apparent prevalence of Mycoplasma wenyonii, Candidatus Mycoplasma haemobos, and bovine leukemia virus in Wisconsin and Michigan dairy cattle herds

Mycoplasma wenyonii (formerly Eperythrozoon wenyonii) is a hemotrophic, epicellular bacterial parasite of cattle that has been associated with clinical disorders, including hemolytic anemia, decreased milk yield, and peripheral edema. Mycoplasma wenyonii and a related organism, Candidatus Mycoplasma haemobos, have been detected in both ill and apparently healthy cattle, but little is known about their prevalence in US dairy cattle. The objective of this prospective, cross-sectional study was to determine herd-level apparent prevalence of M. wenyonii and C. M. haemobos in dairy cattle located in Wisconsin and Michigan compared with seroprevalence of bovine leukemia virus (BLV) in the same herds. In summer 2018, researchers collected blood samples from 30 lactating cows per herd from randomly recruited farms in selected dairy-intensive counties in each state. During the farm visit, a brief survey was used to collect herd management information. Detection of M. wenyonii and C. M. haemobos were based on PCR testing, and ELISA was used to test for antibodies to BLV. Blood samples were collected from lactating cows located in 64 Wisconsin herds (n = 1,930 samples) and 18 Michigan herds (n = 591 samples). Herd-level apparent prevalence was 100% for both M. wenyonii and C. M. haemobos. Herd-level seroprevalence for BLV was 83 and 100% for Wisconsin and Michigan herds, respectively. Estimated within-herd apparent prevalence of M. wenyonii was 71.7% ± 1.0% (ranging from 23.3 to 93.5%) and for C. M. haemobos was 77.3% ± 1.0% (ranging from 16.7 to 100%). Within-herd prevalence of BLV positive samples was 39.8% ± 1.0% and ranged from 0 to 86.7%. About 22% of cows were concurrently positive for all 3 organisms. Parity and stage of lactation were recorded for 2,317 cows. Prevalence of positive cows for parity groups 1, 2, and ≥3 were 72.0, 73.8, and 67.7% for M. wenyonii; 80.9, 76.8, and 74.9% for C. M. haemobos; and 25.3, 39.7, and 55.5% for BLV, respectively. None or only minor differences in apparent prevalence were observed based on stage of lactation. This is the first report of the prevalence of hemotrophic mycoplasmas in Wisconsin and Michigan dairy herds and indicates that infection with these organisms is endemic. The impact of infection on cattle health and productivity remains unknown, and risk factors associated with infection warrant further study.

First molecular detection of Mycoplasma ovis (Hemotropic mycoplasmas) from Sheep in Brazil

Mycoplasma ovis is an emerging zoonotic pathogen with a worldwide distribution and can cause mild to severe hemolytic anemia, icterus, and poor weight gain in animals. Although M. ovis has been described in small ruminants worldwide, data on M. ovis in sheep in Brazil is unknown. The objective of the present study was to present the first report of hemotropic mycoplasma (HM) in sheep from Brazil. We evaluated factors associated with this infection, such age group, tick presence, and anemia. Blood samples were collected from 33 sheep from a farm in southern Brazil and screened for hemoplasmas using PCR. Out of 33 samples, 26 (78.8%) tested positive for M. ovis. The sequencing of positive samples showed 100% identity with multiple M. ovis 16S rDNA sequences. No association was observed between the presence of M. ovis and the FAMACHA© score (p = 0.620). Rhipicephalus (Boophilus) microplus (15/33, 45.4%) was the tick species found on the animals. No significant association between M. ovis infection and presence of ticks (p = 0.4134) and age group (p = 0.4221) was observed. This is the first report of M. ovis infection in sheep from Brazil and only the second report of this pathogen in sheep in Latin America.

Draft Genome Sequence of Mycoplasma wenyonii, a Second Hemotropic Mycoplasma Species Identified in Mexican Bovine Cattle

The hemotropic mycoplasma (hemoplasma) Mycoplasma wenyonii is an animal pathogen that affects bovine cattle health. Here, we present the draft genome sequence of the hemoplasma M. wenyonii strain INIFAP02 found in cattle from Mexico.

Hemotrophic mycoplasma in Simmental cattle in Bavaria: prevalence, blood parameters, and transplacental transmission of 'Candidatus Mycoplasma haemobos' and Mycoplasma wenyonii

Background

The significance of hemotrophic mycoplasma in cattle remains unclear. Especially in Europe, their epidemiological parameters as well as pathophysiological influence on cows are lacking. The objectives of this study were: (1) to describe the prevalence of ‘Candidatus Mycoplasma haemobos’ (‘C. M. haemobos’) and Mycoplasma wenyonii (M. wenyonii) in Bavaria, Germany; (2) to evaluate their association with several blood parameters; (3) to explore the potential of vertical transmission in Simmental cattle; and (4) to evaluate the accuracy of acridine-orange-stained blood smears compared to real-time polymerase chain reaction (PCR) results to detect hemotrophic mycoplasma. A total of 410 ethylenediaminetetraacetic acid-blood samples from cows from 41 herds were evaluated by hematology, acridine-orange-stained blood smears, and real-time PCR. Additionally, blood samples were taken from dry cows of six dairy farms with positive test results for hemotrophic mycoplasma to investigate vertical transmission of infection.

Results

The period prevalence of both species was 60.24% (247/410), C. M. haemobos 56.59% (232/410), M. wenyonii 8.54% (35/410) and for coinfection 4.88% (20/410). Of the relevant blood parameters, only mean cell volume (MCV), mean cell hemoglobin (MCH), and white blood cell count (WBC) showed differences between the groups of infected and non-infected individuals. There were lower values of MCV (P < 0.01) and MCH (P < 0.01) and higher values of WBC (P < 0.05) in ‘C. M. haemobos’-infected cows. In contrast, co-infected individuals had only higher WBC (P < 0.05). In M. wenyonii-positive blood samples, MCH was significantly lower (P < 0.05). Vertical transmission of ‘C. M. haemobos’ was confirmed in two calves. The acridine-orange-method had a low sensitivity (37.39%), specificity (65.97%), positive predictive value (63.70%) and negative predictive value (39.75%) compared to PCR.

Conclusions

‘Candidatus Mycoplasma haemobos’ was more prevalent than M. wenyonii in Bavarian Simmental cattle, but infection had little impact on evaluated blood parameters. Vertical transmission of the infection was rare. Real-time PCR is the preferred diagnostic method compared to the acridine-orange-method.

Draft Genome Sequence of "Candidatus Mycoplasma haemobos," a Hemotropic Mycoplasma Identified in Cattle in Mexico

We present here the draft genome sequence of the first “Candidatus Mycoplasma haemobos” strain found in cattle in Mexico. This hemotropic mycoplasma causes acute and chronic disease in animals. This genome is a starting point for studying the role of this mycoplasma in coinfections and synergistic mechanisms associated with the disease.