Mycoplasma Suis Research Articles

Coinfection of Mycoplasma suis and porcine circovirus type 3 is linked to reproductive failure in pig farms

Coinfection of Mycoplasma suis and porcine circovirus type 3 is linked to reproductive failure in pig farms

Haemotrophic Mycoplasmas Infecting Pigs: A Review of the Current Knowledge.

Haemotrophic mycoplasmas (haemoplasmas) are a group of highly specific and adapted bacteria. Three different haemoplasma species in pigs are known to date: Mycoplasma (M.) suis, M. parvum and 'Candidatus (Ca.) M. haemosuis'. Even though these bacteria have been known in pig farming for a long time, it is difficult to draw general conclusions about the relevance of their infections in pigs. This review summarizes the current knowledge on the three porcine haemoplasma species with regards to clinical and pathological descriptions, pathobiology, epidemiology and diagnostics as well as prevention and therapy. Overall, it is clear that considerably more data are available for M. suis than for the other two species, but generally, porcine haemoplasmas were found to be highly prevalent all over the world. Mycoplasma suis is the most virulent species, causing acute infectious anaemia in pigs (IAP), whereas M. parvum usually results in chronic and subclinical infections associated with performance losses. Little is known about the clinical significance of the recently discovered third porcine species 'Ca. M. haemosuis'. So far, the described pathogenic mechanisms mainly include direct destruction of erythrocytes via adhesion, invasion, eryptosis and nutrient scavenging, indirect erythrocyte lysis due to immune-mediated events and immune dysregulation processes. A review of published diagnostic data confirms PCR assays as the current standard method, with various cross-species and species-specific protocols. Overall, there is a need for further examination to obtain valuable insights for practical application, specifically regarding the importance of subclinical infections in naturally infected animals. An essential requirement for this will be to gain a more comprehensive understanding of the mechanisms operating between the host and the pathogen.

Prevalência molecular do Mycoplasma parvum em granjas de suínos tecnificados de ciclo completo

ABSTRACT Porcine hemoplasmosis is characterized as a geographically cosmopolitan disease caused by Mycoplasma suis and Mycoplasma parvum. Asymptomatic pigs are considered the focus of hemoplasmosis because they are carriers and reservoirs to new infections. This study aimed to determine the molecular occurrence of porcine hemoplasmas (PH) in the production cycle of technified farrow-to-finished swine herds. For this purpose, 20 swine herds were evaluated, where 501 whole blood samples were collected for qPCR and phylogenetic analyses for hemoplasmas. The epidemiological analysis was performed for the entire population and per the growth stage. The total prevalence for PH was 31.93% (161/501); 95% (19/20) of sampled herds were positive. The occurrence of PH by swine growth stages was nursery (30.47%), growing (31.29%), finishing (26.18%), and slaughter (40.25%). The quantification cycles (Cq) ranged from 3.18- 39.56 and the number of PH 16S rRNA copies per µL of DNA ranged from 5,57 x10-2 to 2.23 x1010. Sequencing and phylogenetic analysis of five selected samples showed 100% identity with M. parvum strain Indiana and two M. parvum sequences from Brazil/Goiás. This is the first report on PH in technified herds in Southeastern Brazil by growth stages.

Molecular survey of hemotropic mycoplasmas in crab-eating raccoons (Procyon cancrivorus) in southern Brazil.

Hemoplasmas are non-cultivable bacterial parasites of erythrocytes that infect domestic and wild animals, as well as humans. Their means of transmission and pathogenesis remain contentious issues and difficult to evaluate in wild animals. Procyon cancrivorus is a South American carnivore and occurs in all Brazilian biomes. In this study, we aimed to investigate occurrences of hemoplasmas infecting P. cancrivorus and to identify their 16S rRNA gene, in southern Brazil. DNA was extracted from spleen and blood samples of P. cancrivorus (n = 9) from different locations. Hemoplasma DNA was detected in six samples, based on 16S rRNA gene amplification and phylogenetic analysis. Four of the six sequences belonged to the "Mycoplasma haemofelis group", which is closely related to genotypes detected in Procyon lotor from the USA; one was within the "Mycoplasma suis group", closely related to "Candidatus Mycoplasma haemominutum"; and one was within the intermediate group between these clusters. Thus, these sequences showed that the molecular identity of hemoplasmas in the population studied was very variable. In five positive animals, Amblyomma aureolatum ticks and a flea (Ctenocephalides felis felis) were collected. The present study describes the first molecular detection of mycoplasmas in P. cancrivorus.

Establishment of molecular diagnostics targeting the 23S ribosomal RNA gene for the detection of Mycoplasma suis infection in Thai domestic pigs

Mycoplasma (M.) suis is a pathogenic hemotropic Mycoplasma sp. that causes acute hemolytic anemia or chronic infection in pigs. M. suis infection can be diagnosed using several methods, including molecular diagnosis such as conventional PCR (cPCR) and quantitative PCR (qPCR). In these cases, the common target is the 16S rRNA gene; however, this genetic marker cannot distinguish hemoplasma at the species level owing to high sequence identity. Therefore, the 23S rRNA gene has emerged as another target gene. Other than PCR, the loop-mediated isothermal amplification (LAMP) method can be applied for M. suis. The objective of the present study was to establish cPCR, TaqMan qPCR, and LAMP assays in which the 23S rRNA gene is used to detect M. suis infection in Thai domestic pigs. The analytical sensitivity of cPCR was determined as 7.46 × 104 copies/μl of plasmid DNA, whereas those of qPCR and LAMP were 7.46 × 102 copies/μl. There was no cross reaction with other pathogens in any of the assays. To evaluate the diagnostic performance of the assays, they were tested using 173 samples of genomic DNA. The detection percentage of M. suis infection was 24.86% (43/173; 95% CI: 18.61%–31.89%), 28.32% (49/173; 95% CI: 21.75%–35.66%), and 29.48% (51/173; 95% CI: 22.80%–36.88%) using cPCR, qPCR, and LAMP, respectively. Using qPCR as a reference assay, cPCR showed 81.63% sensitivity, 97.58% specificity, and an almost perfect level of agreement (kappa = 0.823). In comparison, LAMP showed 77.55% sensitivity, 89.52% specificity, and a substantial level of agreement (kappa = 0.662). All assays tested here could be applied in veterinary diagnostic laboratories for monitoring porcine health in the herds. Furthermore, the LAMP assay could be used as a screening test in farm practice without the need for any special equipment.

Molecular detection of vector-borne agents in wild boars (Sus scrofa) and associated ticks from Brazil, with evidence of putative new genotypes of Ehrlichia, Anaplasma, and haemoplasmas.

The present study aimed to investigate, by molecular techniques, the occurrence of Anaplasmataceae, Bartonellaceae, Rickettsiaceae, Mycoplasmataceae, Coxiellaceae, and Babesiidae/Theileriidae agents in blood samples of free-living wild boars (Sus scrofa) and associated ticks in south-eastern Brazil. For this purpose, 67 blood samples and 265 ticks (264 Amblyomma sculptum and one Amblyomma ovale) were analysed. In the screening for Anaplasmataceae agents by a PCR assay based on the 16S rRNA gene, 5.97% blood samples and 50.54% ticks were positive. In the PCR assay for Ehrlichia spp. based on the dsb gene, 9.24% of ticks were positive. Despite the low occurrence, a possible new 16S rRNA genotype of Anaplasma sp. was detected in a wild boar's blood sample. According to phylogenetic analyses based on the 16S rRNA, gltA, and sodB genes and ITS (23S-5S rRNA) intergenic region, it was found that A. sculptum and A. ovale ticks collected from wild boars carry Ehrlichia genotypes phylogenetically associated with Ehrlichia ewingii, Ehrlichia ruminantium, and new Ehrlichia genotypes previously detected in horses, peccaries, and ticks collected from jaguars. In the screening for haemoplasmas by a qPCR based on the 16S rRNA gene, 88.06% of blood samples and 8.69% of ticks were positive. Mycoplasma suis, Mycoplasma parvum, and a possible new haemoplasma genotype were detected in wild boars in south-eastern Brazil. In the screening for Bartonella spp. using a nuoG-based qPCR assay, 3.8% of tick samples were positive. Phylogenetic inferences positioned four nuoG and one r gltA Bartonella sequences into the same clade as Bartonella machadoae. No blood or tick samples from wild boars showed to be positive in the qPCR for Coxiella burnetii based on the IS1111 gene. On the other hand, only 1.6% of ticks were positive in the nested PCR assay for piroplasmids based on the 18S rRNA gene. A 18S rRNA sequence detected in a pool of A. sculptum nymphs was phylogenetically close to Cytauxzoon felis sequences previously detected in cats from the United States. Rickettsia sp. closely related to Rickettsia bellii was detected in a pool of A. sculptum nymphs. This is the first report of haemoplasmas, B. machadoae, and Cytauxzoon spp. in A. sculptum. Wild boars and associated ticks do not seem to participate in the epidemiological cycle of C. burnetii in the region studied. This invasive mammal species may act as a potential disperser of ticks infected with Ehrlichia spp., Bartonella spp., haemotropic mycoplasmas, and Cytauxzoon, and may bring important epidemiological implications in the transmission of bartonelosis, ehrlichiosis, haemoplasmosis, and cytauxzoonosis to humans and animals, more specifically to horses, rodents, pigs, and cats.

Molecular detection and genetic analysis of porcine haemoplasmas in commercial pig farms from Thailand reveal a putative novel species.

Haemoplasma is a trivial name for haemotropic Mycoplasma spp., which can attach to the surface of red blood cells leading to deformity and anaemia in a wide range of mammalian animals, including pigs. In Thailand, there is only one study that reported the occurrence of Mycoplasma suis without other haemoplasma species. In this study, we examined the molecular occurrence and genetic diversity of porcine haemoplasmas in Thai domestic pigs (Sus scrofa domesticus) from commercial farms using a PCR assay targeting the 16S rRNA gene, DNA sequencing, nucleotide sequence type (ntST) analysis and phylogenetic analysis. A total of 665 blood samples were collected from pigs at thirteen farms located in eight provinces of Thailand during 2019-2020. Genomic DNA was extracted from blood samples and tested by PCR. The frequency of haemoplasma infection was 37.1% (247/665, 95% CI: 33.5%-40.9%) in all pigs. Among 247 PCR positive samples, 194 were sequenced and analysed by nucleotide BLAST, ntST diversity, phylogenetic trees and ntST networks. The results of this genetic analysis indicated that at least four species with 27 nucleotide sequence types (Mycoplasma suis, Mycoplasma parvum, Candidatus Mycoplasma haemosuis and a putative novel species) of porcine haemoplasmas were identified. Thus, it appears that haemoplasmas show a high genetic diversity in the Thai pig population. In addition, a putative novel species was genetically characterized by other markers, namely, the 23S rRNA and RNase P RNA (rnpB) genes. For phylogenetic analysis, Candidatus Mycoplasma haemosuis was placed into the Mycoplasma haemofelis group, and the three remaining species were placed into the Mycoplasma suis group in all trees containing the 16S rRNA, 23S rRNA and rnpB genes. Further studies, such as pathobiology and epidemiology, should be conducted to better characterize this putative novel species.

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.

Mycoplasma suis

This datasheet on Mycoplasma suis covers Identity, Overview, Distribution, Hosts/Species Affected, Vectors & Intermediate Hosts, Further Information.

Mycoplasma suis Alpha-Enolase Subunit Vaccine Induces an Immune Response in Experimental Animals.

Recombinant protein technology has emerged as an excellent option for vaccine development. However, prior to our study, the immune induction ability of recombinant Mycoplasma suis alpha-enolase (rMseno) in animals remained unclear. The purpose of this study was to develop a rMseno protein subunit vaccine and to determine its ability to elicit an immunological response. To accomplish this, we cloned the gene into pET-15b, expressed it in BL21 cells, and purified it. Following the establishment of immunity, the immunogenicity and potential for protection of rMseno were evaluated in mice and piglets. The results demonstrate that anti-M. suis serum recognized the pure rMseno protein in both mice and piglets as evidenced by high levels of specific anti-rMseno antibodies, significantly increased levels of IFN-γ and IL-4 cytokines, and significantly increased T lymphocyte proliferation index. Piglets also had significantly increased levels of specific IgG1, IgG2a, CD4+, and CD8+ cells. The rMseno findings demonstrated a robust immunological response in mice and piglets, affording partial clinical protective efficacy in piglets.

Swine hemoplasmosis detected in farms of Argentina by a new nested PCR assay

Swine hemoplasmosis or swine infectious anemia is a worldwide distribution disease caused by the hemotropic mycoplasmas Mycoplasma suis and Mycoplasma parvum. The aim of this study was to determine the presence of M. suis-M. parvum infection in subclinical pigs from herds of Buenos Aires province, Argentina, by means of new nested PCR. The PCR assay primers were designed based on the 16S ribosomal gene sequences of swine hemoplasmas available at GenBank. To standardize the assay, pig blood samples positive for hemoplasma by May Grünwald-Giemsa (MGG) stained blood smears were used. A total of 482 pig blood samples were analyzed. A 32% (154/482) of MGG stained blood smears were positive to M. suis o M. parvum. From these 154 samples, 47% (72/154) were positive by PCR. Sequences of PCR products amplified with these primers always showed identity with M. suisor M. parvum, validating their specificity and highlighting the unspecific amplification with hemoplasmas of other species. This is the first assay designed in Argentina to identify M. suis and M. parvum. However, considering the advances in the knowledge of the genome of hemoplasmas worldwide, further studies should be performed to standardize new assays for the diagnosis of swine hemoplasmosis in Argentina.

Update on shedding and transmission routes of porcine haemotrophic mycoplasmas in naturally and experimentally infected pigs

Horizontal transmission of Mycoplasma suis via parenteral exposure during standard practices or through bites during fightings have been identified as key epidemiological routes. However, as knowledge gaps on other potential shedding and transmission routes exist, the present study combines both laboratory experiments and field surveys to gain new insights into the epidemiology of porcine haemotrophic mycoplasmas. Splenectomised pigs were orally inoculated with a M. suis field strain and investigated for clinical signs related to infectious anaemia of pigs (IAP) and the presence of M. suis in blood, urine and saliva samples by qPCR. All blood samples were negative for M. suis and animals did not show obvious clinical signs of IAP throughout the entire study period. Additionally, urine, nasal and saliva samples from sows of conventional piglet producing farms and semen samples from a boar stud revealed no detection of M. suis and ‘Candidatus Mycoplasma haemosuis’ by qPCR. Thus, the results indicate that blood-independent transmission routes might be of minor relevance under field conditions.

Clinical, haematological and pathomorphological findings in Mycoplasma suis infected pigs

BackgroundMycoplasma suis (M. suis) belongs to the group of haemotrophic mycoplasmas and is known as the causative agent of infectious anaemia in pigs. In the last few years valuable insights into the mechanism of adhesion and invasion, shedding patterns and cell tropism of M. suis were gained by the use of new molecular techniques. However, details on M. suis induced lesions as well as the distribution of M. suis in different organs are still lacking. Therefore, seven splenectomised pigs were experimentally infected and clinical and laboratory investigations as well as a detailed histopathological examination were performed. Detection and quantification of M. suis DNA in blood and various tissue samples was done using a quantitative real-time PCR.ResultsDuring the course of experimental infection, periodically occurring signs of infectious anaemia of pigs including severe icteroanaemia, fever, apathy and anorexia were observed. In addition, dermatological manifestations such as haemorrhagic diathesis presenting as petechiae occurred. The most important haematological alterations were normochromic, normocytic anaemia, hypoglycaemia as well as increased bilirubin and urea concentrations. Necropsy revealed predominant evidence of haemolysis with consecutive anaemia, as well as disseminated intravascular coagulation. M. suis was found in all investigated tissues with the highest copy numbers found in the kidneys. In Giemsa stained sections M. suis was only detected red blood cell (RBC)-associated.ConclusionIn the present study, no RBC independent sequestration of M. suis was detected in organs of experimentally infected pigs. Pathological findings are most likely resulting from haemolysis, consecutive anaemia as well as from disseminated intravascular coagulation and subsequent organ impairments.

Investigation of hemotropic Mycoplasmas in fetuses and sows with reproductive failure

Swine eperythrozoonosis or porcine hemoplasmosis is an infectious disease caused mainly by Mycoplasma suis and is distributed worldwide. This study investigated the occurrence of porcine hemothropic mycoplasmas (PHMs) in fetuses and sows with reproductive failure. Two hundred and seventy-six samples (80 sows’ blood and 196 fetal tissue samples) from 27 farms with reproductive disorders were evaluated. The PHMs DNA was detected in 15 out of 80 (18.7%) sows but it was not detected in the fetuses. The bacterial load ranged from 1.32 × 102 to 2.61 × 105 copies/µL. From the 27 tested herds, 11 (40.7%) showed at least one positive sow per farm. The majority of the reproductive problems observed in PMHs positive sows were stillborn fetuses (46.7%) and stillborn associated with fetal mummification (26.7%). So, we evidenced that porcine hemoplasmas circulate among sows in Brazilian herds, however, its real impact on reproductive problems remains unknown.

Porcine hemothropic mycoplasmas infection associated with productive impact in intensive pig production

BackgroundSo far, three porcine hemoplasmas (PH) have been identified, namely Mycoplasma suis, Mycoplasma parvum, and Mycoplasma haemosuis. The first one is the main agent associated with porcine hemoplasmosis, a possible cause of economic losses in pig production. Thus, this work aimed to detect and quantify PH 16S rRNA in finishing pigs and to associate its load estimate with average daily weight gain (ADWG). For this purpose, whole blood samples from 318 pigs were collected at an age of 75 days (d0) when the pigs entered the finishing phase and 105 days later (d105). To calculate ADWG, the animals were weighed at the abovementioned dates. Then, DNA from blood samples were submitted to a qPCR targeting the 16S rRNA gene for PH. Spearman correlation test was performed to investigate potential associations between ADWG and the quantification values. Lastly, the molecular characterization of PH was done by sequencing the 23S rDNA gene.ResultsOut of the 318 samples, 190 (59.74%) were positive on d0, and 304 (95.6%) were positive on d105. A significant correlation was observed (p < 0.05), albeit with a low coefficient value (0.18), when comparing ADWG with quantification values on d105. The phylogenetic analysis based on the 23S rDNA gene showed that four sequences were closely related to M. parvum, and one sequence was positioned in the M. suis cluster.ConclusionTwo PH, M. suis and M. parvum, were detected in a Brazilian pig farm. Moreover, increasing occurrence through time was observed, which may have affected the productive performance of positive animals, mainly at the end of the finishing phase, when antimicrobials are removed.

The Stable Fly (Stomoxys calcitrans) as a Possible Vector Transmitting Pathogens in Austrian Pig Farms.

This pilot study aimed to investigate stable flies from Austrian pig farms for the presence of defined swine pathogens, such as porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus 2 (PCV2), hemotrophic mycoplasmas in ingested blood and/or body parts and bacteria on the surface of the flies. Furthermore, the use of stable flies as a diagnostic matrix for the detection of pathogens in the ingested pig blood should be investigated. In total, 69 different microorganisms could be found on the surface of tested S. calcitrans from 20 different pig farms. Escherichia coli was the most common bacterium and could be found on flies from seven farms. In seven farms, hemotrophic mycoplasmas were detected in stable flies. PRRSV could not be found in any of the samples of these 20 farms but PCV2 was detected in six farms. Whether the stable fly can be used as a matrix to monitor the health status cannot be accurately determined through this study, especially in regard to PRRSV. Nevertheless, it might be possible to use the stable fly as diagnostic material for defined pathogens like Mycoplasma suis and PCV2.

Genetic diversity of emerging hemotropic mycoplasmas in domestic pigs from Brazil.

Mycoplasma suis and Mycoplasma parvum bind strongly to erythrocytes and may cause clinical hemoplasmosis in swine, affecting several age groups. Mycoplasma spp. infected animals may be asymptomatic carriers and/or show nonspecific clinical signs. In Brazil, information on genetic diversity associated with porcine hemoplasmas (PH) has not been described yet. Therefore, this study has aimed to detect, quantify and characterize the genetic diversity of PH in finishing pigs from technified farms in the state of Goiás, central-western Brazil. Ethylenediaminetetraacetic acid-blood samples from 450 swine belonging to 30 different farms from Goiás state were collected at the slaughterhouse. Quantitative real-time PCR (qPCR) assays were performed for the molecular detection and quantification of PH 16S rRNA gene fragments. Cloning and sequencing of 16S and 23S rRNA amplicons were performed to evaluate the genetic diversity. Moreover, a questionnaire was applied to each farm manager to obtain epidemiological information about the herd. The results on qPCR showed herd occurrence of 68.89% for PH. Quantification values (starting quantity [SQ]) ranged from 8.43×10-1 to 4.69×106 copies/µl, and 52.71% of the samples presented SQ values equal or lower than 1×103 copies/µl. Risk factors were not evaluated once all farms had at least one positive animal. However, Spearman's coefficient test revealed that the occurrence of PH was inversely associated with the number of farrows per week, weaned piglets per week, and weight at slaughter. Phylogenetic analysis based on maximum likelihood and Bayesian methods showed that the 16S rRNA and 23S rRNA gene sequences obtained from five samples formed a single cluster closely related to M. parvum. Genotype analysis using DNASP software confirmed seven and four different 16S and 23S rRNA genotypes among the cloned amplicons, indicating that there are several genotypes of M. parvum circulating in individual pigs and among pig farms in central-western Brazil.

Frequency of infection with Mycoplasma suis in gestating sows using qPCR on ten commercial French herds, and impact of the infection on clinical, haematological and biochemical parameters

Frequency of infection with Mycoplasma suis in gestating sows using qPCR on ten commercial French herds, and impact of the infection on clinical, haematological and biochemical parameters

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

BackgroundIn 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...

Prevalence and phylogenetic analysis of hemoplasma species in domestic pigs in Korea

BackgroundTwo hemoplasma species, Mycoplasma suis and M. parvum, previously known as Eperythrozoon suis and E. parvum, respectively, have been identified in pigs. Swine hemoplasmosis is a global problem, and M. suis infection results in economic losses to pig producers worldwide. This study investigated the frequency and distribution of hemotropic mycoplasmas in pig farms of Korea. As hemoplasmas can be transmitted by ticks, we also analyzed the presence of the tick-borne pathogens Anaplasma spp. and Borrelia spp.MethodsWe screened 1867 samples from 464 pig farms located in four regions of Korea over the period from 2014 to 2018. PCR-positive samples were further analyzed by nucleotide sequencing and phylogenetic analysis of pathogen-specific markers for species identification.ResultsOf the 1867 pigs evaluated in the study, three (0.2%), 51 (2.7%), and one (0.1%) were found to be infected with M. suis, M. parvum, and the novel hemotropic M. haemosuis, respectively; Anaplasma spp. and Borrelia spp. were not detected. The 16S rRNA sequences of M. suis, M. parvum, and the novel hemotropic M. haemosuis were highly similar (99.3–100%, 99.6–100%, and 99.6–100%, respectively) to those of Mycoplasma spp. isolated from other countries. To the best of our knowledge, this is the first nationwide, large-scale study of the molecular detection of Mycoplasma spp. in domestic pigs in Korea.ConclusionsOur results indicate that Mycoplasma infections are widespread in Korean domestic pigs, and that continuous monitoring and control strategies are required to prevent the spread of hemoplasmas, which, in addition to causing economic losses in the pig industry, pose a potential threat to public health. As transmission routes of hemoplasmas remain unelucidated, additional epidemiological studies are recommended to identify reservoirs and vectors of Mycoplasma spp. in Korea.