Molecular detection and occurrence of 'Candidatus Mycoplasma haemobos' in dairy cattle of Southern Brazil

First molecular evidence of bovine hemoplasmas in houseflies (Musca domestica)

BACKGROUND

Hemoplasma infections in cattle are caused by Mycoplasma wenyonii and Candidatus Mycoplasma haemobos and induce asymptomatic or chronic infections but occasionally lead to life-threatening hemolytic anemia. Despite the global distribution of bovine hemoplasmas, information regarding their transmission vectors and prevalence is still lacking in the Republic of Korea. Therefore, this study aims to investigate the infection rate of bovine hemoplasma in cattle and houseflies and to assess the risk factors associated with hemoplasma infection in cattle.

METHODS

Overall, 376 blood samples were collected from Korean indigenous cattle (male, 10-13 months old), along with 2,690 houseflies (Musca domestica) from the same farm where the cattle were raised. PCR assays targeting the 16S rRNA gene were performed to detect hemoplasmas, and positive samples were sequenced.

RESULTS

The infection rate of bovine hemoplasmas was 50.8% (191/376) in cattle and 7.4% in pooled houseflies. Among cattle, 18.6% (70/376) and 20.0% (75/376) tested positive for M. wenyonii and Candidatus M. haemobos, respectively. Conversely, in houseflies, Candidatus M. haemobos was more frequently detected (5.9%) than M. wenyonii (0.7%). Co-infection was 12.2% (46/376) in cattle and 0.7% in flies. Furthermore, hemoplasma infection was significantly associated with the grazing experience of their dams. Cattle born to cows with grazing experience exhibited a higher risk for M. wenyonii infection (odds ratio [OR] = 1.62; 95% confidence interval [CI]: 1.03-2.55; P = 0.045), whereas these cattle had a lower risk for Candidatus M. haemobos infection (OR = 0.32, 95% CI: 0.19-0.74; P = 0.000) than animals born to cows without grazing experience. The sequences obtained from houseflies were confirmed as Candidatus M. haemobos, which displayed high similarity (98.2-100%) to those from cattle obtained in this study.

CONCLUSIONS

To our knowledge, this study represents the first report of bovine hemoplasmas identified in houseflies. This molecular evidence suggests that houseflies may be possible vectors for Candidatus M. haemobos.

First Description of Mycoplasma agalactiae Anatomical Localization in Naturally Infected Hard Ticks (Rhipicephalus bursa)

Mycoplasma agalactiae (Ma) is considered the primary causative agent of contagious agalactia (CA) in sheep and goats, which causes severe losses to the small ruminant dairy industry. As early as 1816, it was thought that environmental factors played a role in pathogen maintenance in endemic areas. Specifically, recent studies hypothesized a vector role for arthropods in the epidemiology of disease. The aim of this study was to investigate the presence and anatomical localization of Ma in naturally infected Riphicephalus bursa ticks to better evaluate tick-pathogen interactions. Salivary glands and ovaries of confirmed Ma-positive R. bursa were analyzed to look for the Ma antigen using immunohistochemistry (IHC). IHC showed strong positivity to Ma in the cytoplasm of salivary cells as well as in cells from the ovary. Our work demonstrated for the first time the crossing of the tick midgut barrier by Ma and the subsequent infection of organs capable of spreading the infection, and this result represents an absolute novelty in disease-related knowledge. Our preliminary results provide conclusive evidence of the potential vector role represented by hard ticks in the epidemiology of CA. Further field and laboratory investigations are necessary to confirm the tick role in the transmission of clinical CA.

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.

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.

Mycoplasma wenyonii and Candidatus Mycoplasma Haemobos in Pastoralists Cattle in Nigeria

PURPOSE

The extensive migration practiced by pastoralists cattle exposes them to a variety of pathogens and vectors which may sometimes lead to severe disease outcomes. Moreover, the synergistic effect of multiple parasitism on the productivity of livestock has been well recognized. This is particularly true where the livestock production system predisposes the animals to constant and heavy infestation with arthropod vectors.

METHODS

The presences, prevalence and risk factors for hemotropic Mycoplasma (hemoplasma) infection in cattle in Nigeria was investigated using a PCR and sequencing approach. DNA, extracted from 566 cattle blood samples, collected from 10 states from the three agro-ecological zones (AEZs) of Nigeria, from April 2021 to March 2022, were screened for the presences of hemotropic Mycoplasma spp. DNA.

RESULTS

The DNA of hemoplasmas was detected in 48 out of the 566 (8.5%) samples, 12 (25%) of them were identified as Mycoplasma wenyonii and 19 (38.6%) as 'Candidatus Mycoplasma haemobos'. Coinfection with both species was detected in 17 (35.4%) of the samples. High prevalence and risk of hemoplasmas infection was associated with sex of the cattle (bulls were more affected; p = 0.005) and the packed cell volume (p = 0.009), but not with the age (p = 0.08), breed (p = 0.22), body condition (p = 0.052), source of the samples (p = 0.45) or the AEZs (0.59). This is the first nationwide survey of hemotropic mycoplasmas in cattle in Nigeria using this molecular approach.

CONCLUSION

Further studies to determine the veterinary and public health significance of these pathogens, which were previously associated with varying degrees of clinical signs and production losses, are recommended in Nigerian cattle.

Abortion outbreak in pregnant goats and cows with coinfection of 'Candidatus Mycoplasma haemobos' and HoBi-like pestivirus

New emerging diseases, including 'Candidatus Mycoplasma haemobos' ('Ca. M. haemobos') and HoBi-like pestivirus in central China has been a huge challenge for ruminant production. From July to September 2022, an abortion outbreak affected 14 goat farms and 11 cattle farms in this area. To investigate whether the two pathogens are associated with the disease, samples were collected: Group 1 included 55 goat blood samples with foetal tissue samples and ticks on the skin; Group 2 included nine healthy goat blood samples; Group 3 included 36 cow blood samples with foetal tissue samples and ticks on the skin; and Group 4 included seven healthy cow blood samples. Then, these samples were analysed by serology, PCR, sequence analysis, and identification. A total of 339 Rhipicephalus (Boophilus) microplus and 61 Haemaphysalis longicornis ticks were identified in Group 1 and Group 3. By molecular detection, 32 'Ca. M. haemobos'-positive amplicons, and 27 HoBi-like pestivirus-positive amplicons were amplified from goats in Group 1; meanwhile, 20 'Ca. M. haemobos'-positive amplicons, and 18 HoBi-like pestivirus-positive amplicons were amplified from foetuses. Statistical significance (P = 0.002) and association (OR=7.556) between the 'Ca. M. haemobos' PCR results of foetus and goat samples were observed, and statistical significance (P = 0.017) and association (OR=4.271) between the HoBi-like pestivirus PCR results of foetus and goat samples were observed. These significances and associations were also observed in Group 3. In addition, coinfections were detected in Group 1 and Group 3. 'Ca. M. haemobos' was detected in both tick species. Further serological results revealed that the frequency of HoBi-like pestivirus was 20.0 % (11/55) in Group 1 % and 30.6 % (11/36) in Group 3 in central China. No ticks, pathogens, or neutralizing antibodies were observed in Group 2 or Group 4. This is the first molecular evidence of 'Ca. M. haemobos' and HoBi-like pestivirus natural coinfections in goats and cows with abortion in China. HoBi-like pestivirus and 'Ca. M. haemobos' can be transferred from goats/cows to their foetuses.

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.

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.

Detection of Mycoplasma agalactiae in Ticks (Rhipicephalus bursa) Collected by Sheep and Goats in Sicily (South-Italy), Endemic Area for Contagious Agalactia

The aim of this preliminary study was to investigate the presence of Mycoplasma agalactiae (Ma) or other Contagious Agalactia (CA) causative organisms, in hard ticks infesting milking sheep and goats in endemic areas for CA in Sicily (South-Italy). Although there is accumulating evidence to support the role of ticks in the transmission of blood-borne haemoplasmas, information regarding their role in the transmission of CA, remains scarce. Ticks (n = 152) were collected from 25 lactating sheep and goats from three farms with previous outbreaks of CA. Microbiological and biomolecular, as well as serological analysis were performed on milk, tick, and serum samples, respectively. Rhipicephalus bursa species predominated, comprising 84.8% of the sampled ticks. Mycoplasma-like colonies were isolated from 5/56 (8.9%) tick pools and were identified as Ma by specific PCR and 16S rRNA gene sequencing. Unexpectedly, the organism was isolated from R. bursa ticks recovered only from animals whose milk tested negative for the pathogen. This preliminary demonstration suggests the potential role for ticks to act as a reservoir for the organisms, with potential involvement in the spread and maintenance of CA. Further work is required to determine the location of the organisms within the body of the ticks and to assess transmission potential.

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.

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.

Detection of a novel haemoplasma species in fattening pigs with skin alterations, fever and anaemia

BACKGROUND

In a fattening farm in Southern Germany, skin alterations (urticaria, haemorrhagic diathesis) and high fever were observed in 30% of the pigs 2 weeks after arrival. Feed intake was severely compromised in affected pigs.

METHODS

After detailed clinical observation, blood samples from affected pigs were collected for haematological, PCR and serological investigations. In addition, pathological investigations were performed on one pig.

RESULTS AND CONCLUSION

Analysis of blood parameters revealed a normocytic, normochromic anaemia. A novel porcine haemoplasma species was detected in blood samples of affected pigs and spleen sample of the necropsied pig by PCR. Phylogenetic analyses based on the 16S rDNA showed 99% identity to a novel porcine haemoplasma ('Candidatus (Ca.) M. haemosuis') species which has recently been described in China. Interestingly, this is the first report of 'Ca. M. haemosuis' in pigs with clinical signs resembling those of Mycoplasma (M) suis and the first description of this novel haemoplasma species outside Asia. On-farm affected pigs were treated with oxytetracycline and non-steroidal anti-inflammatory drugs. Clinical signs improved after implementation of treatment and optimisation of management procedures. This case might indicate that other porcine haemoplasma species than M suis can induce fever and skin alterations and may have an economic impact on affected farms.

Bovine abortion, stillbirth and neonatal death associated with Babesia bovis and Anaplasma sp. infections in southern Brazil

Anaplasmosis and babesiosis are tick-borne diseases widely disseminated in cattle herds in many parts of the world. These diseases represent important causes of death and economic losses in several countries, including Brazil, and are characterized by hemolytic disease and anemia. Animals of all ages may be affected. Although transplacental infections are known to occur, abortion, stillbirth and neonatal death directly associated with Anaplasma marginale and especially Babesia spp. infections have rarely been documented in cattle. The objective of the present study is to describe the pathological and molecular findings of two cases of bovine abortion, two cases of stillbirth and two cases of neonatal death associated with intrauterine anaplasmosis and/or babesiosis in southern Brazil. All cases occurred in beef farms in the state of Rio Grande do Sul, between 2017 and 2019. Angus and crossbred calves were affected. At the necropsy, the main gross lesions observed included different degrees of splenomegaly, enlarged and yellow liver, thick and grumous bile, pallor or jaundice of mucous membranes and carcass, and dark kidneys. Four calves also presented cherry-pink discoloration of the central nervous system. Cytological slides enabled the observation of intraerythrocytic organisms consistent with Babesia bovis (3/6) and A. marginale (2/6). Through PCR assays, it was possible to detect three cases of Babesia sp. infection alone, and one case of Anaplasma sp. infection alone. Co-infections with Anaplasma sp. and Babesia sp. were detected in two cases. These findings reaffirm that anaplasmosis and babesiosis should be considered as an important differential diagnosis of fetal loss, stillbirth and neonatal death in cattle in areas where these diseases occur.

Genetic diversity and lack of molecular evidence for hemoplasma cross-species transmission between wild and synanthropic mammals from Central-Western Brazil

Globally, hemotropic mycoplasmas (hemoplasmas) comprise an emerging or remerging bacteria group that attaches to red blood cells of several mammal's species and in some cases, causing hemolytic anemia. Herein, we assessed the occurrence, genetic diversity, the factors coupled to mammals infection, and the phylogeographic distribution of hemoplasmas in sylvatic and synanthropic mammals and their associated ectoparasites from Brazil. We collected spleen and/or blood samples from synanthropic rodents (Rattus rattus [N = 39] and Mus musculus [N = 9]), sylvatic rodents (Hydrochoerus hydrochaeris [N = 14]) and opossums (Didelphis albiventris [N = 43]). In addition, ticks (Amblyomma spp. [N = 270] and lice (Polyplax spinulosa [N = 6]) specimens were also sampled. Using a PCR targeting the 16S rRNA region, out of 48 small rodents, 14 capybaras and 43 opossums DNA samples, hemoplasma DNA was found in 25%, 50%, and 32.5% animals, respectively. Besides, we reported hemoplasma DNA in Amblyomma sp. (22.2% [2/9]) and lice (100% [2/2]) pools samples from rats, and one female A. sculptum DNA sample (3% [1/33]) obtained from a capybara. Additionally, and in agreement with ML analysis, the network analyses showed a clear phylogenetic separation among the hemoplasmas genotypes found in the different host species sampled, thus, suggesting the absence of cross-species hemoplasmas transmission between the mammals trapped. Finally, using the NTC network analysis, we reported the same 16S rRNA Mycoplasma genotype circulating in Rattus sampled in Brazil, Hungary, and Japan.

Comparison of Light Microscopy and Polymerase Chain Reaction for the Detection of Haemoparasites in Cattle in Nigeria

PURPOSE

Haemoparasitic diseases are among the important factors that threaten cattle health and productivity especially in the sub-Saharan region. In Nigeria, their detection using sensitive molecular techniques is scanty. This study was designed to investigate and to reevaluate the repertoire of haemoparasites of cattle in Ibadan, Nigeria with a comparative evaluation of light microscopy (LM) and polymerase chain reaction (PCR) methods.

METHODS

Blood samples from 100 cattle slaughtered at Ibadan abattoirs were examined using LM and PCR techniques for haemoparasite detection. The PCR reactions using three primer sets targeting the 16S rRNA genes for Hemoplasma spp. and Anaplasma/Ehrlichia spp. and 18S rRNA genes of Babesia/Theleiria spp. were done. A few randomly selected amplicons from each set were sequenced and analysed.

RESULTS

A total infection rate of 34% by LM including Hemoplasma spp. (17%), Anaplasma spp. (16%), microfilaria (5%) and Trypanosoma spp. (12%) was recorded. While, 86% positivity was recorded with PCR amplification as follows: Hemoplasma spp. (64%), Babesia/Theleiria spp. (46%) and Anaplasma/Ehrlichia spp. (5%). Comparison of LM and PCR findings showed that no LM Anaplasma spp.-positive samples and 7 out of the 17 LM hemoplasma-positive cattle were confirmed by PCR. In addition, LM led to misdiagnosis of 46 Babesia/Theleiria spp.-positive samples. Amplicon sequencing and phylogenetic analysis of Babesia/Theileria spp.-positive samples revealed Theileria velifera and Theileria annulata. In the Anaplasma/Ehrlichia spp.-positive samples, only Anaplasma marginale was characterized. Mycoplasma wenyonii, "Candidatus Mycoplasma haemobos" and Pseudomonas fluorescens like were characterized among the hemoplasma-infected cattle.

CONCLUSIONS

The first report of "Candidatus Mycoplasma haemobos" and Pseudomonas fluorescens like in Nigerian cattle is herewith documented. The alarming LM misdiagnosis of haemoparasites during this study confirms its limitations as it fails to identify many parasites and emphasizes the need for inclusion of molecular techniques to improve their detection. The study also shows for the first time the high prevalence of haemotropic mycoplasma in Nigerian cattle via molecular diagnostic methods, thus indicating a strong need for the investigation of their zoonotic implications.

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 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.

First molecular evidence of bovine hemoplasma species (Mycoplasma spp.) in water buffalo and dairy cattle herds in Cuba

BACKGROUND

Hemotropic mycoplasmas (aka hemoplasmas) are small bacteria which cause infectious anemia in several mammalian species including humans. Information on hemoplasma infections in Cuban bovines remains scarce and no studies applying molecular methods have been performed so far. The aim of the present study was to utilize real-time PCR and sequence analysis to investigate dairy cattle and buffalo from Cuba for the presence of bovine hemoplasma species.

RESULTS

A total of 80 blood samples from 39 buffalo and 41 dairy cattle were investigated for the presence of Mycoplasma wenyonii and "Candidatus Mycoplasma haemobos" using two species-specific real-time TaqMan PCR assays. PCR results revealed overall 53 (66.2%; 95% CI: 55.3-75.7%) positive animals for M. wenyonii and 33 (41.2%; 95% CI: 31.1-52.2%) for "Ca. M. haemobos"; the latter were all co-infections with M. wenyonii. The sample prevalences were similar in cattle and buffalo. Based on the sequence analysis of the nearly full-length 16S rRNA gene from two cattle and two buffalo, the presence of M. wenyonii and "Ca. M. haemobos" was confirmed. Statistical analysis revealed that buffalo and cattle one year of age or older were more frequently infected with M. wenyonii or "Ca. M. haemobos" than younger animals. PCR-positivity was not associated with anemia; however, the infection stage was unknown (acute infection versus chronic carriers).

CONCLUSIONS

The high occurrence of bovine hemoplasma infections in buffalo and dairy cattle may have a significant impact on Cuban livestock production. To the best of our knowledge, this is the first molecular evidence of bovine hemoplasma species infection in dairy cattle and buffalo from Cuba and the Caribbean.

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.

Molecular investigation of "Candidatus Mycoplasma haemobos" in goats and sheep in central China

Hemoplasma "Candidatus Mycoplasma haemobos" infections in cattle have been reported in East Asia, Europe, and South America, whereas same cases were documented in buffalo and cattle in Southern China. From April 2018 to May 2018, a mycoplasma epidemic was reported in the mountainous area of central China; Boophilus microplus has also been documented, causing severe haematuria in goats and sheep. The infected animals slowly recovered after diminazene aceturate and praziquantel treatment. To determine whether the hemoplasma caused this infection, 67 blood samples (42 from goats, 25 from sheep) and 132 B. microplus samples were collected for PCR and sequence analysis. The results showed that 19 out of the 42 goat blood samples, 10 out of the 25 sheep blood samples, and 70 out of the 132 B. microplus samples (53%) tested positive for "C. M. haemobos". This study provides molecular evidence of "C. M. haemobos" infections in goat and sheep, and that B. microplus harbours "C. M. haemobos".

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.

Hemotropic mycoplasmas infection in water buffaloes (Bubalus bubalis) from northeastern Brazil

Two species of hemotropic mycoplasmas (HM) are known to infect large domestic ruminants, Mycoplasma wenyonii and 'Candidatus Mycoplasma haemobos'. Although HM has been described in cattle worldwide, data in water buffaloes (Bubalus bubalis) remain scarce. Accordingly, the aim was to determine the occurrence of HM in water buffaloes from northeastern Brazil. A total of 101/290 (34.83%) buffaloes were positive for HM (16 M. wenyonii alone, 6 'Ca. M. haemobos' alone and 79 both). This was the first report of M. wenyonii infection in ruminants from Brazil. Clinical signs of hemoplasmosis in buffaloes remain unknown.

Detection and identification of blood-borne infections in dogs in Nigeria using light microscopy and the polymerase chain reaction

Many sick dogs brought to the University of Ibadan Veterinary Teaching Hospital (UIVTH) are infested with ticks and are anemic. Up until recently, light microscopy (LM) has been the only available means used for detection of blood-borne infections. In other parts of the world, PCR-based assays been used as a gold standard for accurate diagnosis of blood-borne infections. In this study, we used LM and broad-spectrum rRNA gene PCR-based assays on 116 blood samples from dogs brought to the UIVTH for detection of the 18S rRNA gene of Babesia and the 16S rRNA genes of Ehrlichia and hemotropic mycoplasmas. The relationship between clinicopathological findings and PCR results was evaluated. Age, sex, presence of ticks, anemia, co-infection status, and fever were also assessed in relation to PCR positivity to determine the risk factors using stepwise logistic regression analyses. Light microscopic examination revealed an overall prevalence of infection of 14.7% (17/116). Organisms detected were Babesia canis (3.5%), Ehrlichia canis (10.3%) and Trypanosoma congolense (0.9%) and a single co-infection with Babesia canis and Ehrlichia canis (0.9%). PCR analysis revealed 89/116 (76.7%) positive samples. Infections with 1, 2 and 3 infectious agents occurred in 49 (55.1%), 36 (40.4%) and 4 (4.5%) samples, respectively. Specifically, among the 89 PCR positive samples, Babesia spp. (85.4%) was the most abundant infection followed by Ehrlichia spp. (46.1%) and hemoplasmas (13.5%). Sequencing of PCR products identified two samples (1.7%) that contained Hepatozoon canis DNA. Sequencing of hemoplasma positive samples identified 'Candidatus Mycoplasma haemobos' in 0.8% of dogs. Using PCR, a 5-fold higher prevalence of blood-borne infections was found in the dogs (76.7%, 89/116) than with LM (14.7%, 17/116) alone" Dogs between 1 and 12months were the most frequently infected with multiple agents (47.2% double and 50.0% triple infections). Male dogs had the highest prevalence of infection (80.4%) and more triple infections (75.0%). A total of 57.3% of infected dogs were anemic. Anemic dogs were 2.77 times more likely to test positive for Ehrlichia spp. (OR: 2.77 95% CI: 1.25-6.16) and dogs with ticks were 3.6 times more likely to test positive for hemoplasmas (OR=3.60 95% CI: 1.05-12.38). This study underscores the abundance of blood-borne infections in dogs in Ibadan, Nigeria, which is underestimated using light microscopy. This is also the first evidence of existence of 'Candidatus Mycoplasma haemobos' in a dog in Nigeria and in Africa. Consequently there is a need for molecular diagnostic facilities for routine screening of sick animals, as multiple infections were not found by light microscopy.

'Candidatus Mycoplasma haemobos': Transplacental transmission in dairy cows (Bos taurus)

'Candidatus Mycoplasma haemobos' is a haemotropic mycoplasma that can produce various clinical signs in cattle, but abortive potential of the parasite is unknown, as well as the frequency of transplacental transmission in cattle. Thus, the objective of this work was to evaluate the frequency of detection of 'C. M. haemobos' in aborted fetuses and the blood of dairy cows. Blood samples of 22 dairy cows that aborted and pool tissues (brain, lung, heart and liver) of their respective aborted fetuses were tested by conventional PCR. The occurrence of 'C. M. haemobos' DNA in adult animals was 40.9% (9/22) and in the fetuses was 18.2% (4/22). Two fetuses that contained 'C. M. haemobos' DNA were derived from cows which were PCR negative. When stratifying by breed, it was observed that Jersey cows had a higher proportion of positive animals (8/11; 72.7%) as compared to Holstein (1/9; 11.1% P<0.01). The results of this study suggest that this parasite can be transferred via the placenta, but it is not certain if the abortions were due to 'C. M. haemobos'.

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.

Occurrence and identification of hemotropic mycoplasmas (Hemoplasmas) in free ranging and laboratory rats (Rattus norvegicus) from two Brazilian zoos

BACKGROUND

Hemotropic mycoplasmas (hemoplasmas), bacteria belonging to the class Mollicutes, are obligatory red blood cell pathogens of a variety of animal species. They may cause acute anemia that is life-threatening or chronic disease that is clinically silent, but may interfere with results of experimental studies when using infected animals. Since these bacteria cannot be cultivated, molecular techniques are the gold standard for diagnosing an infection, investigating its prevalence, and describing new species. Mycoplasma coccoides and M. haemomuris are the most commonly recognized hemoplasmas in the blood of wild and laboratory rodents. Neither the epidemiology nor clinical and molecular characterization of hemoplasma infection in free-ranging rodents in Brazil has been previously reported. The aims of this study were to investigate the occurrence of hemoplasmas in free-ranging rats (Rattus norvegicus) captured in the Passeio Público and Curitiba Zoo and compare hematologic parameters of infected and non-infected animals.

RESULTS

Anti-coagulated blood samples collected from 43 free-ranging and 20 nursery rats were included in the study. Overall 63.5% were positive using SYBR® Green quantitative PCR (qPCR) of the 16S rRNA gene to screen for hemoplasma infection (72% among free-ranging rats; 45% among laboratory-raised rats). Sequencing of the qPCR products showed that all but one sample had >98% identity to M. haemomuris. Phylogenetic analysis based on a fragment of approximately 1300 bp of the 16S rRNA gene showed 99% identity to a new hemoplasma from European rats and 98% identity to a hemotropic mycoplasma described infecting a European harvest mouse (Micromys minutus). No statistically significant changes in hematologic parameters between infected and non-infected rats were found, confirming the low pathogenicity and/or silent characteristics of the infection.

CONCLUSIONS

Our findings suggest that hemoplasmas are likely endemic in rodent species in this region. The epidemiology, especially as it relates to the mode of transmission, needs to be further investigated as well as the possibility that other animal species, including humans, might become infected.

Prevalence and phylogenetic analysis of haemoplasmas from cats infected with multiple species

Mycoplasma haemofelis (Mhf), ‘Candidatus Mycoplasma haemominutum’ (CMhm) and ‘Candidatus Mycoplasma turicensis’ (CMt) are agents of feline haemoplasmosis and can induce anaemia in cats. This study aimed to determine the prevalence and phylogeny of haemoplasma species in cats from Brazil's capital and surrounding areas, and whether correlation with haematological abnormalities existed. Feline haemoplasmas were found in 13.8% of 432 cats. CMhm was the most prevalent species (in 13.8% of cats), followed by Mhf (11.1%) and CMt (4.4%). Over 80% of haemoplasma-infected cats harboured two or more feline haemoplasma species: 7.1% of cats were co-infected with Mhf/CMhm, 0.4% with CMhm/CMt and 3.9% with Mhf/CMhm/CMt. Male gender was significantly associated with haemoplasma infections. No association was found between qPCR haemoplasma status and haematological variables, however CMhm relative copy numbers were correlated with red blood cell (RBC) numbers and packed cell volume (PCV). Haemoplasma 16S rRNA gene sequences (> 1 Kb) were derived from co-infected cats using novel haemoplasma species-specific primers. This allowed 16S rRNA gene sequences to be obtained despite the high level of co-infection, which precluded the use of universal 16S rRNA gene primers. Within each species, the Mhf, CMhm and CMt sequences showed > 99.8%, > 98.5% and > 98.8% identity, respectively. The Mhf, CMhm and CMt sequences showed > 99.2%, > 98.4% and > 97.8% identity, respectively, with GenBank sequences. Phylogenetic analysis showed all Mhf sequences to reside in a single clade, whereas the CMhm and CMt sequences each grouped into three distinct subclades. These phylogeny findings suggest the existence of different CMhm and CMt strains.

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Over 80% of haemoplasma-infected cats had more than one haemoplasma species.

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The use of species-specific primers allowed derivation of 16S rDNA sequences from co-infected cats.

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Male gender was significantly associated with haemoplasma infection.

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Phylogenetic analysis showed subclade formation within two of the haemoplasma species sequences.

Effect of chronic hemoplasma infection on cattle productivity

The present study evaluated the effect of hemoplasmosis on cattle productivity. Prevalence of bovine hemoplasma was examined by polymerase chain reaction (PCR) using whole blood samples collected from 93 breeding cows and their 71 calves in Hokkaido, Japan. Monthly milk production records and other clinical data were compared between Mycoplasma wenyonii (Mw)-infected, “Candidatus Mycoplasma haemobos” (CMh)-infected, co-infected and PCR-negative groups. Blood chemical parameters were obtained from the 93 cows and 64 calves. PCR results showed that 89.2% (83/93) of cows and 14.1% (10/71) of calves were positive for bovine hemoplasma. Based on productivity data obtained from the 93 cows, Mw-infected, CMh-infected and co-infected cows had significantly lower monthly milk yield compared to PCR-negative cows. Furthermore, decline in milk yield was prolonged in CMh-infected and co-infected groups. No significant differences were found for other clinical findings among the four groups. Calf birth weight tended to be lower for Mw-infected, CMh-infected and co-infected groups compared to the PCR-negative group. There were no significant differences in all blood parameters of cows and calves among the four groups. In addition, no significant differences were found in any parameter between hemoplasma-infected and PCR-negative calves.