Effect of chronic hemoplasma infection on cattle productivity

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.

Hemotrophic Mycoplasmas-Vector Transmission in Livestock

Hemotrophic mycoplasmas (HMs) are highly host-adapted and specialized pathogens infecting a wide range of mammals including farm animals, i.e., pigs, cattle, sheep, and goats. Although HMs have been known for over 90 years, we still do not know much about the natural transmission routes within herds. Recently, it has been repeatedly discussed in publications that arthropod vectors may play a role in the transmission of HMs from animal to animal. This is mainly since several HM species could be detected in different potential arthropod vectors by PCR. This review summarizes the available literature about the transmission of bovine, porcine, ovine, and caprine HM species by different hematophagous arthropod vectors. Since most studies are only based on the detection of HMs in potential vectors, there are rare data about the actual vector competence of arthropods. Furthermore, there is a need for additional studies to investigate, whether there are biological vectors in which HMs can multiply and be delivered to new hosts.

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.

Molecular Detection of Hemoplasma in animals in Tamil Nadu, India and Hemoplasma genome analysis

Hemoplasma are small pleomorphic wall-less Gram-positive bacteria that infect erythrocytes of various mammalian hosts. They generally cause asymptomatic or chronic anaemia but occasionally causes overt life-threatening hemolytic anaemia. In the present study, 316 cattle, 115 sheep, 61 goats and 6 buffalo blood samples were collected from various villages or organized farms located in nine districts of Tamil Nadu to detect the hemoplasma by PCR. Overall prevalence of 43.04%, 65.22%, and 44.26% hemoplasma DNA was observed in cattle, sheep and goats, respectively. In total, 21 hemoplasma positive samples were sequenced for 16S rRNA gene which revealed 8 Mycoplasma wenyonii, 11 'Candidatus Mycoplasma haemobos' and one Mycoplasma ovis infection. Sheep blood samples from Chennai district were infected with 'Ca. M. haemobos' whereas sheep sample from Thiruvannamalai district was infected with M. wenyonii. At least 50% genes in the hemoplasma genomes were paralogous genes whose functions were not known. Only 'Ca. M. haemolamae' genome contained one primitive CRISPR system without any cas genes. Antimicrobial resistance genes (ARG) could not be identified in any of the hemoplasma genomes but homologous ARG were identified in all the genomes. Adhesion related gene EF-Tu was detected in all 14 hemoplasma genomes but enolase gene was detected only in 'Ca. M. haemohominis' SWG34-3 genome. This is the first report on the prevalence of hemoplasma infection in cattle, sheep and goat in India.

Preliminary report of Mycoplasma Wenoynii and Candidatus Mycoplasma haemobos infection in Korean native cattle

BACKGROUND

Hemotropic mycoplasmas or hemoplasmas are bacteria that attach to the erythrocyte surface and cause bovine hemoplasmosis. Two species, Mycoplasma wenyonii and Candidatus Mycoplasma haemobos, have been identified and shown to be distributed worldwide. However, there is currently no information available on hemoplasmas in cattle in the Republic of Korea. The aim of this study was to investigate the presence of hemoplasmas in Korean native cattle and to evaluate the association between hemoplasma infection and anemia.

METHODS

One farm was selected, at which blood samples were collected from 104 Korean native cattle [grazing cattle (n = 89) and housed cattle (n = 15)]. Hemoplasmas were detected via polymerase chain reaction analysis and complete blood counts were also performed.

RESULTS

The overall prevalence of hemoplasmas was 34% (35/104); 20.2% (21/104) for M. wenyonii, 3.8% (4/104) for C. M. haemobos, and 9.6% (10/104) for co-infection. Candidatus Mycoplasma haemobos was detected only in grazing cattle. Of red blood cell (RBC) parameters, C. M. haemobos-infected cattle had lower RBC and hematocrit, and higher mean cell volume than hemoplasma-negative cattle, although none of these differences were statistically significant. This is the first study to report the occurrence of M. wenyonii and C. M. haemobos. Mycoplasma wenyonii is more prevalent than C. M. haemobos in Korean native cattle. The results did not show an association between hemoplasma infection and anemia.

CONCLUSIONS

Considering the infection rate of hemoplasmas shown in this study, further studies, such as on the pathogenicity and clinical significance of hemoplasmas are necessary.

Molecular prevalence of bovine hemoplasmosis in Turkey with first detection of Mycoplasma wenyonii and Candidatus Mycoplasma haemobos in cattle and water buffalo

Hemoplasma species can cause infection varying from mild to severe in a wide range of hosts, including cattle and water buffalo. Two hemoplasma species, Mycoplasma wenyonii and Candidatus Mycoplasma haemobos, have been reported in cattle and water buffalo from different parts of the world to date. There was a lack of information on the presence and distribution of these pathogens in Turkey despite the negative economic impact on livestock production. This study aimed to develop a duplex PCR assay amplifying the 16S rRNA gene, in order to analyze DNA samples obtained from 297 cattle and 360 water buffaloes, and to determine the molecular prevalence of bovine hemoplasma species in Sivas province. Bovine hemoplasma species were found in 94 of 297 (31.64%) cattle and in 17 of 360 (4.72%) water buffaloes in this study. Randomly selected six positives PCR products (three samples each species) obtained from cattle and water buffaloes were sequenced, and the consensus sequences were uploaded to GenBank. Nucleotide similarity of 96.97-100% was determined between M. wenyonii isolates obtained in this study and those of M. wenyonii isolates present in the GenBank database, whereas C. Mycoplasma haemobos isolates from this study shared 99.04-100% homology with the C. Mycoplasma haemobos isolates uploaded to the GenBank. With the current study, the molecular presence of M. wenyonii and C. Mycoplasma haemobos were documented for the first time in cattle and water buffaloes in Turkey. Considering the rate of prevalence, veterinarians should take precautions against bovine hemoplasma species to protect animal health.

An Update of Bovine Hemoplasmas Based on Phylogenetic and Genomics Analysis

Mycoplasma wenyonii and 'Candidatus Mycoplasma haemobos' are bacteria that have been described as significant hemoplasmas that infect cattle worldwide. Currently, three bovine hemoplasma genomes are known. This work aimed to describe the main genomic characteristics and the evolutionary relationships between hemoplasmas, and provide a list of epitopes predicted by immunoinformatics as diagnostic candidates for bovine hemoplasmosis. Thus far, there is no vaccine to prevent this disease that economically impacts cattle production worldwide. Additionally, there is a lack of vaccines against bovine hemoplasmosis. In this work, we performed a genomic characterization of hemoplasmas, including two Mexican strains reported in bovines in the last few years. The generated information is a new scenario about the phylogeny of hemoplasmas. Also, we show genomic features among hemoplasmas that strengthen their characteristic genome plasticity of intracellular lifestyles. Finally, the elucidation of antigenic proteins in Mexican strains represents an opportunity to develop molecular detection methods and diagnoses.

First Report of ‘Candidatus Mycoplasma haematomacacae’ in Laboratory-Kept Rhesus Monkeys (Macaca mulatta) Maintained in Rio de Janeiro, Brazil

Simple Summary

Health assessment in animals used in research studies are essential, since only animals that present no diseases are considered suitable for these purposes. In laboratory kept animals, a bacterium that infects red blood cells, named hemotropic Mycoplasma (also called hemoplasmas), has been described as problem for research studies. Different hemoplasma species have been detected infecting monkeys from Brazil. However, the occurrence of these bacteria in monkeys maintained in laboratory in Brazil have never been described. Accordingly, this study aimed: (1) to screen laboratory-kept rhesus monkeys for hemoplasmas; (2) to verify if any of the hemoplasma-positive animals demonstrate a decrease in their red blood cells counts; and (3) to investigate the genetic diversity of hemoplasma species in monkeys from Brazil. Five out of eight (62.5%) rhesus monkeys tested positive for hemoplasmas using a technique that detects DNA from these bacteria in monkey’s blood. Further analysis demonstrated that rhesus monkeys were infected by a species named ‘Candidatus Mycoplasma haematomacacae’ that had already been described occurring in monkeys from Japan and USA. Although no decreases on red blood cells count were perceived in rhesus monkeys evaluated herein, future studies are needed to elucidate if ‘Ca. M. haematomacacae’ is a problem for research studies that use rhesus monkeys.

Abstract

Health monitoring programs in animals used as experimental models are essential, since only disease-free subjects are considered suitable for research purposes. In laboratory-kept animals, hemoplasmas have been described as an important confounding variable. Different hemoplasma species have been detected infecting non-human primates (NHP) from Brazil. However, the occurrence of hemoplasma species in laboratory-kept NHP in Brazil has not-yet been assessed. Accordingly, this study aimed (i) to screen laboratory-kept rhesus monkeys for hemoplasmas, (ii) to verify if any of the hemoplasma-positive animals demonstrate hematological abnormalities, and (iii) to assess the genotype diversity of hemoplasma species in NHP from Brazil. Five out of eight (62.5%; 95% CI: 3.05–8.63) rhesus monkeys tested positive for hemotropic Mycoplasma spp. by PCR. Sequencing, phylogenetic, distance, and genotype diversity analyses of partial 16S rRNA gene demonstrate that rhesus monkeys were infected by ‘Candidatus Mycoplasma haematomacacae’ (formerly ‘Candidatus Mycoplasma haemomacaque’). Assessments of partial 16S rRNA diversity of hemoplasma species in NHP suggest that at least four genetically diverse groups may occur in Brazil. Although no hematological abnormalities were demonstrated in rhesus monkeys evaluated herein, future studies are needed to elucidate the influence of ‘Ca. M. haematomacacae’ as a confounding variable on research studies.

Molecular detection of Mycoplasma wenyonii and its closely related hemotropic Mycoplasma sp. in blood-sucking flies from a buffalo farm in Chachoengsao province, Thailand

Bovine hemoplasmosis is a disease in buffaloes and cattle caused by hemotropic mycoplasmas or hemoplasmas. Only two bovine hemoplasma species, Mycoplasma wenyonii and Candidatus Mycoplasma haemobos, have been described in several countries. Hemoplasmas induce acute hemolytic anemia or chronic infection, leading to production loss. Bovine hemoplasma DNA was also detected in blood-sucking arthropods, suggesting vector transmission in farms. To date, no studies of the molecular detection of bovine hemoplasmas in Thai buffaloes and arthropod vectors have been reported. This study aimed to study the 1-year diversity of hematophagous flies in a buffalo farm located in Chachoengsao province, Thailand, and to investigate the molecular occurrence of bovine hemoplasmas in those flies using a polymerase chain reaction (PCR) assay and sequence analyses. A total of 1,488 mosquitoes, 867 stable flies, and 312 tabanid flies were collected during this study. The most abundant mosquitoes, stable flies, and tabanid flies were Culex tritaeniorhynchus, Stomoxys calcitrans, and Tabanus megalops, respectively. A total of 249 genomic DNA samples of flies were tested using a PCR assay based on the 16S rRNA gene; 23.69% (59/249) of the insect samples were positive in this assay. Positive samples (n = 8) were subjected to bidirectional sequencing. The BLAST results showed that only three samples from Stomoxys calcitrans and two samples from Tabanus megalops showed 99.90% and 99.17% similarities to the M. wenyonii isolate B003 (MG948626/Water buffalo/Cuba) and the M. wenyonii isolate C124 (MG948625/Cattle/Cuba), respectively. This molecular occurrence of bovine hemoplasmas in blood-sucking flies suggested that those flies are the mechanical vectors for bovine hemoplasmas in Thailand. Based on the phylogenetic analysis of the 16S rRNA gene, the sequences of M. wenyonii were likely classified into two subgroups (A and B), suggesting closely related bovine hemoplasma species. Finally, the genetic analysis of the 23S rRNA gene from these two subgroups revealed that subgroup A could be M. wenynoii and subgroup B may be a subspecies of M. wenyonii or another putative novel species. However, further investigation should be conducted in buffaloes, cattle, and blood-sucking flies to gain more 16S rRNA and 23 rRNA gene sequences of bovine hemoplasmas.

Molecular detection of haemophilic pathogens reveals evidence of Candidatus Mycoplasma haemobos in dogs and parasitic ticks in central China

Background

In addition to Mycoplasma haemocanis and Candidatus Mycoplasma haematoparvum, a few hemoplasma species that mainly infect other livestock have been detected in dogs. ‘Candidatus Mycoplasma haemobos’ (Ca. M. haemobos) has been found in a variety of animals in China. The present study was aimed to investigate the occurrence of ‘Ca. M. haemobos’ infections in dogs and ticks collected from the Henan province, China.

Results

Overall, 55 dog blood samples and 378 ticks on skins were collected from anemic and healthy dogs, and these samples were subjected to PCR, sequence analysis, and identification. The results showed that Haemaphysalis longicornis (266) and Rhipicephalus (Boophilus) microplus (112) were the only two parasitic ticks on dogs. Molecular detection revealed that 163 M. haemocanis, 88 ‘Ca. M. haemobos’ and 32 Anaplasma platys positive amplicons could be amplified from dogs, H. longicornis and R. (B.) microplus. In addition, co-infections (M. haemocanis + A. platys and ‘Ca. M. haemobos’+ A. platys) could be also detected.

Conclusions

To the best of our knowledge, this is the first molecular evidence of ‘Ca. M. haemobos’ natural infection in dogs and tick species identified as H. longicornis and R. (B.) microplus from China.

First study on microscopic and molecular evidences of two bovine hemoplasma species in cattle herds in Al-Qadisiyah Province, Iraq

Background and Aim:

Hemotropic Mycoplasmas are small epierythrocytic bacteria that cause infectious anemia in several livestock species and in humans. Several reports have been made on hemoplasma infections in the south and north of Iraq, but there have been no studies in the middle Euphrates of Iraq. This study aimed to evaluate the presence of hemoplasma species in cattle in Al-Qadisiyah Province, Iraq.

Materials and Methods:

Two hundred blood samples were collected from cattle with pale mucous membrane from regions with heavy tick endemicity. The samples were analyzed for the presence of Rickettsia pathogens using thin blood smears and the Diff-Quik stains. All the samples were also examined using polymerase chain reaction (PCR) to amplify the 16S ribosomal ribonucleic acid (rRNA) gene to confirm the presence of the smear-identified microorganisms. Ten PCR positive samples were subjected to 16S rRNA partial gene sequencing to identify the species.

Results:

The findings uncovered positivity in 68 (34%) blood smears. PCR revealed positive confirmation in 18 (9%) of the 200 blood samples. Mycoplasma wenyonii and Candidatus mycoplasma hemobos were identified from 10 PCR positive samples. The nucleotide sequences of the isolates were closely related to isolates from cattle, buffalo, and dogs in Vietnam, Cuba, India, and Germany.

Conclusion:

Bovine hemoplasma infections are prevalent in cattle in the Al-Qadisiyah Province in Iraq. Our results may have significance for the development of control programs.

Expanding the Universe of Hemoplasmas: Multi-Locus Sequencing Reveals Putative Novel Hemoplasmas in Lowland Tapirs (Tapirus terrestris), the Largest Land Mammals in Brazil

The lowland tapir (Tapirus terrestris) is the largest land mammal in Brazil and classified as a vulnerable species, according to the assessment of the risk of extinction. The present study aimed at investigating the occurrence and genetic diversity of hemoplasmas in free-ranging T. terrestris from the Brazilian Pantanal and Cerrado biomes. Blood samples were collected from 94 living and eight road-killed tapirs, totalizing 125 samples Conventional PCR targeting four different genes (16S rRNA, 23S rRNA, RNAse P, and dnaK) were performed, and the obtained sequences were submitted for phylogenetic, genotype diversity, and distance analyses. The association between hemoplasma positivity and possible risk variables (age, gender, and origin) was assessed. Out of 122 analyzed samples, 41 (41/122; 33.61% CI: 25.84-42.38%) were positive in the 16S rRNA-based PCR assay for hemoplasmas. Positivity for hemoplasmas did not differ between tapirs' gender and age. Tapirs from Pantanal were 5.64 times more likely to present positive results for hemoplasmas when compared to tapirs sampled in Cerrado. BLASTn, phylogenetic, genotype diversity, and distance analyses performed herein showed that the sampled lowland tapirs might be infected by two genetically distinct hemoplasmas, namely 'Candidatus Mycoplasma haematoterrestris' and 'Candidatus Mycoplasma haematotapirus'. While the former was positioned into "Mycoplasma haemofelis group" and closely related to 'Candidatus Mycoplasma haematoparvum, the latter was positioned into "Mycoplasma suis group" and closely related to 'Candidatus Mycoplasma haematobos'. The impact of both putative novel species on tapir health status should be investigated.

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.

Mo­lecular evidence and epidemiology of “Candidatus Mycoplasma haemobos” among cattle in Peninsular Malaysia using the 16S rRNA gene

Haemotropic Mycoplasma infection among cattle has not been seriously looked into, despite the fact it is associated with poor weight gain and depression. One thousand and forty-five blood samples from apparently healthy cattle from forty-three farms within the entire Peninsular Malaysia were exa­mined over a one-year period. Using polymerase chain reaction to amplify the 16S rRNA gene, the presence of “Candidatus Mycoplasma haemobos” as one of the haemotropic Mycoplasma species that affects cattle in the country was detected. Forty-seven percent of the sampled population was positive for “C. M. haemobos”, with the antigen present in all herds sampled. Breed of cattle, gender, age, production type, physiological status, herd size, management system, farm size, farm age, prophylactic treatment against blood parasites, presence of ticks, frequency of de-ticking, zone, closeness to forest, closeness to waste area, closeness to human settlement and closeness to body of water were all significantly associated (P<0.05) with the detection of “C. M. haemobos”. The findings from this study will be pivotal in government policy on this blood Mycoplasma infection, as the study happens to be the first comprehensive molecular survey of the microorganism in the country.

Detection of Mycoplasma wenyonii and "Candidatus Mycoplasma haemobos" from Japanese Black breeding cows in Kyushu and Okinawa region, southern part of Japan

This study aimed to elucidate the epidemiological status of hemoplasma infection and investigate the interaction between Theileria orientalis and hemoplasmas in Japanese Black breeding cows raised in the Kyushu and Okinawa regions. Blood samples were collected from 400 cows from 80 different farms in eight prefectures (five samples per farm and 10 farms per prefecture). Mycoplasma wenyonii (Mw), “Candidatus Mycoplasma haemobos” (CMh), and T. orientalis were examined by polymerase chain reaction (PCR) assay using whole blood samples. PCR results showed that 91.5% (366/400) of cows were positive for bovine hemoplasma: 40.3% were infected with Mw only, 9.5% with CMh only, and 41.8% with both species. T. orientalis was detected in 36% (144/400) of cows. The infection rate of T. orientalis was higher in the grazing group (P<0.001) than in the housed group, while the rate of CMh infection was higher (P<0.05) in the housed group than in the grazing group, suggesting that not only the tick but also other arthropod vectors may contribute to hemoplasma transmission. Although the cows with hemoplasma dual infection showed higher (P<0.05) white blood cell counts compared with hemoplasma-negative cows, there was no difference in hematologic parameters related to the anemia between the hemoplasma-positive and -negative animals. This may indicate that Japanese Black cattle could have resistance to the anemia caused by infection with hemoplasma.

Bovines Harbor a Diverse Array of Vector-Borne Pathogens in Northeast Algeria

Arthropod-borne hemoparasites represent a serious health problem in livestock, causing significant production losses. Currently, the evidence of Anaplasma spp., Theileria spp., Babesia spp., and hemotropic Mycoplasma spp. in Algeria remains limited to a few scattered geographical regions. In this work, our objectives were to study the prevalence of these vector-borne pathogens and to search other agents not yet described in Algeria as well as the identification of statistical associations with various risk factors in cattle in the northeast of Algeria. Among the 205 cattle blood samples tested by PCR analysis, 42.4% positive results were obtained for at least one pathogen. The overall rates of Anaplasma spp., Theileria/Babesia spp., and Mycoplasma spp. in the cattle sampled were respectively 30.7%, 18.5%, and 2.9%; co-infections with multiple species was also detected. Anaplasma spp. and Theileria/Babesia spp. were detected at a higher rate in cattle under 3 years old, according to univariate analysis. Anaplasma spp. DNA was detected more frequently in our sample in cattle living in semi extensive farming. Our study provides additional data about Anaplasma spp., Theileria/Babesia spp. and reveals for the first time that Mycoplasma wenyonii and ‘Candidatus Mycoplasma hemobos are present in cattle in Northeast Algeria.

First Molecular Detection and Characterization of Hemotropic Mycoplasma Species in Cattle and Goats from Uganda

Hemoplasmas (hemotropic mycoplasmas) are small pleomorphic bacteria that parasitize the surface of red blood cells of several mammalian species including cattle, goats, and humans, causing infectious anemia. However, studies on hemoplasmas have been neglected and to date, there are no studies on bovine and caprine hemoplasmas in Uganda or the entire East African region. In this study, a polymerase chain reaction (PCR) assay targeting the 16S rRNA gene was used to investigate the presence of hemoplasma in 409 samples (cattle = 208; goats = 201) collected from Kasese district, western Uganda. Results showed that 32.2% (67/208) of cattle samples and 43.8% (88/201) of goat samples were positive for hemoplasmas. Sequencing analysis identified Candidatus Mycoplasma haemobos and Mycoplasma wenyonii in cattle, while Candidatus Mycoplasma erythrocervae and Mycoplasma ovis were identified in goats. Statistical analysis showed that goats were at a higher risk of infection with hemoplasmas compared with cattle. To the best of our knowledge, this is the first molecular evidence of hemoplasmas in bovine and caprine animals in Uganda and the entire east African region.

Molecular survey of tick-borne pathogens infecting backyard cattle and water buffaloes in Quezon province, Philippines

Tick-borne diseases (TBD) cause enormous losses for farmers. Backyard raising comprises majority of the livestock population in the Philippines, but TBD information in backyard livestock is scarce. In this study, 48 cattle and 114 water buffalo samples from Quezon province, Philippines were molecularly screened for tick-borne pathogens. Anaplasma marginale (16.67%) and hemoplasma (20.99%) were detected in the samples. A. marginale infection (P=0.0001) was significantly higher in cattle, while hemoplasma infection (P=0.011) was significantly higher in water buffaloes. A. marginale isolates from this study were highly similar to previous isolates from the Philippines while Mycoplasma wenyonii and Candidatus Mycoplasma haemobos were the identified hemoplasma species. Our findings reveal additional information on the TBD situation of Philippine backyard livestock.

Occurrence and genetic diversity of hemoplasmas in beef cattle from the Brazilian Pantanal, an endemic area for bovine trypanosomiasis in South America

Hemotropic mycoplasmas (hemoplasmas) are Gram-negative bacteria that parasitize the erythrocyte surface of a wide variety of mammals. The present study aimed at investigating the occurrence of hemoplasmas in beef cattle in the Brazilian Pantanal, an area endemic for bovine trypanosomiasis in South America. Additionally, the objective of this study was to characterize molecularly the genotypes of the found hemoplasmas. For this purpose, blood and serum samples of 400 beef cattle were collected from five properties in Corumbá, Nhecolândia sub-region, Mato Grosso do Sul, in Midwest Brazil. Blood samples underwent DNA extraction and standard 16S rRNA gene-based PCR assays for hemoplasmas. The sequences obtained were submitted to phylogenetic inferences, distance analysis, and genotype diversity. The Indirect Enzyme-Linked Immunoabsorbent Assay (iELISA) indicated the presence of anti-Trypanosoma vivax IgG antibodies in 89.75% of the animals sampled, confirming the endemicity of said agent in the studied region. Among the 400 bovine blood samples tested, 2.25% (9/400) were positive for hemoplasmas in cPCR. The phylogenetic analysis of the obtained sequences confirmed the presence of 'Candidatus Mycoplasma haemobos' and Mycoplasma wenyonii DNA in 0.5% (2/400) and 1.75% (7/400) animals, respectively. Five genotypes of M. wenyonii and one of 'Candidatus M. haemobos' were detected among the sequenced amplicons. The present study showed low molecular occurrence of haemoplasmas in beef cattle sampled in the Brazilian Pantanal, an area endemic for bovine trypanosomiasis. Despite of the conservation of the 16S rRNA gene, there was considerable diversity of hemoplasma genotypes infecting the sampled beef cattle.

First detection of Mycoplasma wenyonii in France: Identification, evaluation of the clinical impact and development of a new specific detection assay

Mycoplasma wenyonii, a hemoplasma infecting cattle, was never detected in France. In 2014, evocative inclusions were observed in erythrocytes from cattle presenting milk drops, anemia, and edema in Brittany (France). A survey was then initiated to investigate the epidemiological situation and correlate mycoplasma detection with clinical signs. For this purpose, a new PCR assay targeting polC gene was designed. Comparative results with published PCR assays place this new one as more specific, allowing a one-step diagnosis without further sequencing. A total of 181 cows were included in this study and 4.97% (n = 9) were positive, resulting in the first molecular identification of M. wenyonii in France. All positive animals presented anemia, edema and milk drop. When selecting animals presenting evocative clinical signs, the prevalence of M. wenyonii in Brittany was estimated to 25.6%. Further studies are needed to evaluate the importance of the infection, the implication of arthropods and the existence of asymptomatic carriers.

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.

Quantitative analysis of Mycoplasma wenyonii and 'Candidatus Mycoplasma haemobos" infections in cattle using novel gapN-based realtime PCR assays

Hemotrophic mycoplasmas (HMs) are associated with anemia and other disease complexes in a wide range of livestock and wild animals. Two bovine HM species have been identified to date, i.e. Mycoplasma wenyonii and 'Candidatus Mycoplasma haemobos'. The study aim was to develop quantitative real-time PCR assays (qPCRs) to detect and quantify M. wenyonii and 'C. M. haemobos' and to apply these assays to DNA samples extracted from bovine blood collected in Germany (n = 220) from 22 herds. The qPCR assays specific for M. wenyonii and 'C. M. haemobos' were designed using the gapN of the respective hemoplasma species as gene target which encodes the NADP-dependent glyceraldehyde 3-phosphate dehydrogenases (GAPN). The sensitivity of both assays was 10 genome equivalents per reaction, corresponding to 2500 genome equivalents per ml blood. No cross-reactivity with non-target bovine HMs. and other bovine pathogens was observed. Bovine HM DNA was detected in 137 samples (62.27%) with 118 samples (53.64%) being positive for 'C.M. haemobos' and 19 samples (8.64%) being positive for M. wenyonii. Thereof, 11 animals (5.00%) were co-infected with both bovine HM species. The found herd prevalence for `C. M. haemobos` was 100.00%, and for M. wenyonii 36.36% with mean bacterial loads of 3.7 × 10⁷ `C. M. haemobos`/mL blood and of 4.29 × 10⁵M. wenyonii/mL blood respectively. Clinical and economic relevance of bovine HM species should be goal of future studies for which the novel gapN qPCR assays can serve as a valuable diagnostic tool.

Historical review and insights on the livestock tick-borne disease research of a developing country: The Philippine scenario

Tick-borne diseases (TBDs) remain to be a global animal health threat. Developing countries like the Philippines is not exempt to this. Despite the potential impact TBDs can give to these countries, local government initiatives and researches remain to be limited. In the Philippines, most epidemiological studies were confined only to specific areas, and predominantly in the Northern Area. Due to its unique geography and limited studies, the current nationwide status of most TBDs could not be clearly established. This review mainly covered published studies and presented challenges in the conduct of TBD research in the Philippines, which may be similar to other Southeast Asian or developing countries. To date, reported livestock TBD pathogens in the Philippines include Anaplasma, Babesia, Theileria, and Mycoplasma spp. With the ubiquitous presence of the Rhipicephalus microplus ticks in the country, it is highly probable that other pathogens transmitted by these vectors could be present. Despite studies on different TBDs in the livestock sector, the Philippine government has not yet heightened its efforts to implement tick control measures as part of the routine animal health program for local farmers. Further studies might be needed to determine the nationwide prevalence of TBDs and the presence of other possible tick species and TBD pathogens. The Philippine scenario may present situations that are similar to other developing countries.

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

BACKGROUND AND CASE PRESENTATION

A three year old, second lactation Holstein dairy cow presented to the Scottish Centre for Production Animal Health and Food Safety, Glasgow University Veterinary School in November 2014 with a history of post-calving vulval/vaginal bleeding nine days prior to presentation, followed by a sudden reduction in milk yield. Subsequent investigations resulted in a diagnosis of immune-mediated haemolytic anaemia secondary to infection with Mycoplasma wenyonii.

CONCLUSION

This report of a novel presentation of Mycoplasma wenyonii in a dairy cow illustrates the need to consider M.wenyonii as a potential differential diagnosis when a cow presents with anaemia and will discuss the potential implications of the condition at herd-level.