The virulence of T-mycoplasmas, isolated from various animal species, assayed by intramammary inoculation in cattle

A Review of Ureaplasma diversum: A Representative of the Mollicute Class Associated With Reproductive and Respiratory Disorders in Cattle

The Mollicutes class encompasses wall-less microbes with a reduced genome. They may infect plants, insects, humans, and animals including those on farms and in livestock. Ureaplasma diversum is a mollicute associated with decreased reproduction mainly in the conception rate in cattle, as well as weight loss and decreased quality in milk production. Therefore, U. diversum infection contributes to important economic losses, mainly in large cattle-producing countries such as the United States, China, Brazil, and India. The characteristics of Mollicutes, virulence, and pathogenic variations make it difficult to control their infections. Genomic analysis, prevalence studies, and immunomodulation assays help better understand the pathogenesis of bovine ureaplasma. Here we present the main features of transmission, virulence, immune response, and pathogenesis of U. diversum in bovines.

Ureaplasma diversum and Its Membrane-Associated Lipoproteins Activate Inflammatory Genes Through the NF-κB Pathway via Toll-Like Receptor 4

Objectives:Ureaplasma diversum is a pathogen of cows that may cause intense inflammatory responses in the reproductive tract and interfere with bovine reproduction. The aims of this study were to evaluate the immune response of bovine blastocysts and macrophages to U. diversum infection and to evaluate the invasion capacity of this microorganism in bovine blastocysts.

Methods: Viable and heat-inactivated U. diversum strains ATCC 49782 and CI-GOTA and their extracted membrane lipoproteins were inoculated in macrophages in the presence or absence of signaling blockers of Toll-Like Receptor (TLR) 4, TLR2/4, and Nuclear Factor KB (NF-κB). In addition, the same viable U. diversum strains were used to infect bovine blastocysts. RNA was extracted from infected and lipoprotein-exposed macrophages and infected blastocysts and assayed by qPCR to evaluate the expression of Interleukin 1 beta (IL-1β), Tumor Necrosis Factor Alpha (TNF-α), TLR2 and TLR4 genes. U. diversum internalization in blastocysts was followed by confocal microscopy.

Results: Both Ureaplasma strains and different concentrations of extracted lipoproteins induced a higher gene expression of IL-1β, TNF-α, TLR2, and TLR4 in macrophages (p < 0.05) when compared to non-infected cells. The used blockers inhibited the expression of IL-1β and TNF-α in all treatments. Moreover, U. diversum was able to internalize within blastocysts and induce a higher gene expression of IL-1b and TNF- α when compared to non-infected blastocysts (p < 0.05).

Conclusion: The obtained results strongly suggest that U. diversum and its lipoproteins interact with TLR4 in a signaling pathway acting via NF-kB signaling to stimulate the inflammatory response. This is the first study to evaluate the in vitro immunological response of macrophages and bovine blastocysts against U. diversum. These results may contribute to a better understanding of the immunomodulatory activity and pathogenicity of this infectious agent.

[Identification of species of Mycoplasma and Ureaplasma diversum from Argentinian dairy herds]

Several species of Mycoplasma and Ureaplasma diversum can cause diseases in dairy cattle, which can be associated or not with clinical manifestations. In our country, the presence of Mycoplasma bovis, Mycoplasma californicum and Mycoplasma canadense has been detected, being the only mycoplasma species identified so far. The objective of this study was to identify other species of the Mycoplasmataceae family. Thirty-five Mycoplasma spp.-like isolates obtained from different samples from cattle, with or without clinical symptoms, from eight herds located in the provinces of Santa Fe, Cordoba, Buenos Aires and San Luis were utilized in the present study. Through the use of species-specific polymerase chain reactions (PCR) Mycoplasma bovigenitalium, Mycoplasma alkalescens, Mycoplasma bovirhinis and U. diversum were identified and through amplification and further sequencing of the 16-23S rRNA intergenic spacer regions, Mycoplasma arginine and M. californicum were identified. The identification of these species represents an important advance in knowledge in order to include these pathogens in the differential diagnosis of certain clinical and pathological entities of cattle from Argentina.

Ureaplasma diversum Genome Provides New Insights about the Interaction of the Surface Molecules of This Bacterium with the Host

Whole genome sequencing and analyses of Ureaplasma diversum ATCC 49782 was undertaken as a step towards understanding U. diversum biology and pathogenicity. The complete genome showed 973,501 bp in a single circular chromosome, with 28.2% of G+C content. A total of 782 coding DNA sequences (CDSs), and 6 rRNA and 32 tRNA genes were predicted and annotated. The metabolic pathways are identical to other human ureaplasmas, including the production of ATP via hydrolysis of the urea. Genes related to pathogenicity, such as urease, phospholipase, hemolysin, and a Mycoplasma Ig binding protein (MIB)-Mycoplasma Ig protease (MIP) system were identified. More interestingly, a large number of genes (n = 40) encoding surface molecules were annotated in the genome (lipoproteins, multiple-banded antigen like protein, membrane nuclease lipoprotein and variable surface antigens lipoprotein). In addition, a gene encoding glycosyltransferase was also found. This enzyme has been associated with the production of capsule in mycoplasmas and ureaplasma. We then sought to detect the presence of a capsule in this organism. A polysaccharide capsule from 11 to 17 nm of U. diversum was observed trough electron microscopy and using specific dyes. This structure contained arabinose, xylose, mannose, galactose and glucose. In order to understand the inflammatory response against these surface molecules, we evaluated the response of murine macrophages J774 against viable and non-viable U. diversum. As with viable bacteria, non-viable bacteria were capable of promoting a significant inflammatory response by activation of Toll like receptor 2 (TLR2), indicating that surface molecules are important for the activation of inflammatory response. Furthermore, a cascade of genes related to the inflammasome pathway of macrophages was also up-regulated during infection with viable organisms when compared to non-infected cells. In conclusion, U. diversum has a typical ureaplasma genome and metabolism, and its surface molecules, including the identified capsular material, represent major components of the organism immunopathogenesis.

Genome Sequence of Ureaplasma diversum Strain ATCC 49782

Here, we report the complete genome sequence of Ureaplasma diversum strain ATCC 49782. This species is of bovine origin, having an association with reproductive disorders in cattle, including placentitis, fetal alveolitis, abortion, and birth of weak calves. It has a small circular chromosome of 975,425 bp.

A quantitative TaqMan PCR assay for the detection of Ureaplasma diversum

Ureaplasma diversum in veterinary studies is an undesirable microbe, which may cause infection in bulls and may result in seminal vesiculitis, balanopostitis, and alterations in spermatozoids, whereas in cows, it may cause placentitis, fetal alveolitis, abortion, and birth of weak calves. U. diversum is released through organic secretions, especially semen, preputial and vaginal mucus, conjunctival secretion, and milk. The aim of the present study was to develop a TaqMan probe, highly sensitive and specific quantitative PCR (qPCR) assay for the detection and quantification of U. diversum from genital swabs of bovines. Primers and probes specific to U. diversum 16S rRNA gene were designed. The specificity, detection limit, intra- and inter-assay variability of qPCR to detect this ureaplasma was compared with the results of the conventional PCR assay (cPCR). Swabs of vaginal mucus from 169 cows were tested. The qPCR assay detected as few as 10 copies of U. diversum and was 100-fold more sensitive than the cPCR. No cross-reactivity with other Mollicutes or eubacteria was observed. U. diversum was detected in 79 swabs (46.42%) by qPCR, while using cPCR it was detected in 42 (25%) samples. The difference in cPCR and qPCR ureaplasma detection between healthy and sick animals was not statistically significant. But the U. diversum load in samples from animals with genital disorders was higher than in healthy animals. The qPCR assay developed herein is highly sensitive and specific for the detection and quantification of U. diversum in vaginal bovine samples.

Invasion of Ureaplasma diversum in bovine spermatozoids

BACKGROUND

Ureaplasma diversum has been associated with infertility in cows. In bulls, this mollicute colonizes the prepuce and distal portion of the urethra and may infect sperm cells. The aim of this study is to analyze in vitro interaction of U. diversum isolates and ATCC strains with bovine spermatozoids. The interactions were observed by confocal microscopy and the gentamycin internalization assay.

FINDINGS

U. diversum were able to adhere to and invade spermatozoids after 30 min of infection. The gentamicin resistance assay confirmed the intracellularity and survival of U. diversum in bovine spermatozoids.

CONCLUSIONS

The intracellular nature of bovine ureaplasma identifies a new difficulty to control the reproductive of these animals.

Ureaplasma diversum as a cause of reproductive disease in cattle

This article includes a brief review of the classification, habitat, and characteristics of the ureaplasmas, followed by a discussion of the pathogenesis, transmission, clinical syndromes, diagnosis, immunity, and treatment of Ureaplasma diversum infections in cattle.

Isolation of Ureaplasma diversum and mycoplasmas from genital tracts of beef and dairy cattle in Saskatchewan

We report herein a survey in which cultures of bovine reproductive tracts for Ureaplasma diversum and mycoplasmas were carried out in order to better understand the role of these organisms in granular vulvitis (GV). Samples cultured were vulvar swabs from clinically normal cows or ones with GV, preputial swabs or raw semen from bulls, and abomasal contents of aborted fetuses.Ureaplasma diversum was isolated from 104 (43.3%) of 240 dairy cows, 32 (27.1%) of 118 beef cows, 43 (47.2%) of 91 beef heifers, 23 (67.6%) of 34 beef bulls, and three (60%) of five dairy bulls. Mycoplasmas were isolated from 18 (7.5%) dairy cows, two (1.6%) beef cows, three (8.8%) beef bulls, and one dairy bull. No isolation was made from 97 aborted fetuses. For 65 dairy cows and 30 beef heifers with vulvar lesions, the isolation rates for ureaplasmas of 62.5% and 69.7%, respectively, were significantly higher (X(2)) than those for normal animals (37.5% and 30.3%). On immunofluorescent serotyping of 137 of the 205 isolates, there were 66 in serogroup C (strain T44), 18 in serogroup B (strain D48), eight in serogroup A (strain A417 or strain 2312), 14 cross-reacting, and 31 that were not identified. It was concluded that U. diversum is commonly present in the lower reproductive tract of beef/dairy cattle in Saskatchewan and is associated with granular vulvitis.

The ovine mammary gland as an experimental model to determine the virulence of animal ureaplasmas

As an estimate of their virulence, the ability of ovine, bovine, canine, feline and simian ureaplasma strains to cause mastitis in the ovine mammary gland was investigated. Five ovine ureaplasmas produced a clinical mastitis. Broth cultures of seven bovine ureaplasmas were unable to infect the ovine gland, but two of these strains plus one other were able to do so following passage through the bovine udder. One of two canine strains and a feline strain both caused mastitis, but the simian strain persisted at low titre for only 5 days post-inoculation in one of the two ewes tested.

The pathogenicity of some ovine or caprine mycoplasmas in the lactating mammary gland of sheep and goats

Mycoplasma ovipneumoniae, M. arginini and M. conjunctivae were each inoculated into the lactating mammary gland of goats and sheep. M. ovipneumoniae was mastitogenic in both species, causing persistent colonization, raised lacteal cell numbers, decreased milk output and separation of milk into 3 layers throughout the periods of observation in virtually all animals. Its effects in sheep were variable, however, and appeared to depend less on the strain and titre of inoculum than on individual variation in response. M. arginini and M. conjunctivae were not mastitogenic for goats, but one of each pair of sheep injected with these agents showed organism persistence at high titres and lacteal neutrophilia over 9 days of observation. Effects on milk production were obscured by the apparent poor ability of the ovine udder to regain previous yield after a fall in output, but milk consistency and appearance were only temporarily or mildly affected in these animals. A. laidlawii, injected into sheep only, produced transient effects but with poor recovery of milk production after elimination of the organism. Goats were superior to sheep in consistency of reaction and milk output, and equally if not more susceptible to intra-mammary challenge with M. ovipneumoniae. The goat was therefore concluded to be the better experimental animal in a potentially useful method for screening strains of M. ovipneumoniae for virulence.

The experimental production of mastitis in ewes as a determinant of the virulence of ovine ureaplasma strains

Seven out of eight ovine ureaplasma strains inoculated into the mammary gland of suckling ewes produced a mastitis. The pattern of infection was single phase in 5 ewes, persisting for 12-41 days, and biphasic in 3 ewes, persisting in 2 of them until weaning at 60 days and 3 months post-infection. Sucking lambs did not become infected in the eye or nasal areas, and did not transfer infection to the control contralateral glands.

Bovine genital mycoplasmosis

Infection, lesions and clinical significance of Acheloplasmas, Mycoplasma bovis and Mycoplasma bovigenitalium in genital disease of cattle are described. A more detailed account is given of ureaplasma infections. Acute and chronic forms of granular vulvitis in both field and experimental disease are described as well as the role of the organism in abortion. Recovery rates of ureaplasma and mycoplasma from semen and preputial washings in bulls are outlined and their significance in disease is discussed. There are problems in differentiating pathogenic from nonpathogenic isolates. Methods are being developed to treat semen for these organisms. This paper provides a concise summary of clinical and microbiological aspects of bovine genital mycoplasmosis.

Experimental bovine genital ureaplasmosis. I. Granular vulvitis following vulvar inoculation

Granular vulvitis was reproduced in ten virgin heifers following vulvar inoculation with strains of ureaplasma previously isolated from natural cases. The disease appeared one to three days postinoculation and was characterized by vulvar swabs but not from the upper mucopurulent discharge. At necropsy 13 to 41 days later, ureaplasmas were recovered consistently from vulvar swabs but not from the upper reproductive tract. It was concluded that some strains of ureaplasma are pathogenic and should be viewed as a cause of bovine granular vulvitis.

The effect of an intramammary infusion of endotoxin on experimentally induced mycoplasmal mastitis

The infusion of 10 microgram of endotoxin lipopolysaccharide from Escherichia coli into the mammary gland of four cows 16 h before inoculation with ureaplasmas did not prevent, or even diminish, the subsequent ureaplasmal mastitis. There was no reduction in the severity or duration of the inflammatory cell response in milk or in the clinical appearance of the resulting mastitis. Also, the excretion of ureaplasmas was not reduced. A similar experiment with Mycoplasma dispar in two cows demonstrated that endotoxin was again ineffective in preventing the mastitis. Furthermore, there was some indication that the proliferation and excretion of this mycoplasma was enhanced in endotoxin-treated quarters.

Bovine granular vulvitis associated with ureaplasma infection

A granular vulvitis syndrome associated with ureaplasma infection was first recognized in Ontario dairy herds in 1972. The acute form of the disease was characterized by a purulent vulvar discharge, an inflamed hyperemic vulvar mucosa and varying degrees of granularity. In the chronic form, there was an absence of a purulent discharge and a gradual decline in the severity of the hyperemia and granularity. Epithelial inclusion cysts were observed in the vulvar epithelium of approximately 10% of affected cows.A seasonal variation in the incidence of the disease was observed. Herd morbidities during the summer months reached a low of 37% and increased to 75% during the winter months with constant housing.When widespread in herds, the acute form of the disease had a significant effect on fertility. In four herds examined, first service conceptions dropped on average by 27%. The chronic form of the disease had a less detrimental effect on fertility with first service conceptions being reduced on average by 13%. Intrauterine infusions of a tetracycline 24 hours postbreeding were found to be of value in improving conception rates in acutely affected herds.

Isolation of Ureaplasma from bovine granular vulvitis

Cultures for mycoplasmatales, viruses and bacteria were made from bovine vulvar swabs to determine whether ureaplasma was associated with a clinical granular vulvitis observed in 16 Ontario dairy herds. Ureaplasma was isolated from 23.5% of 34 clinically normal cows, 74% of 27 cows with mild to moderate vulvar hyperemia but no discharge and 100% of 20 cows with acute vulvar hyperemia accompanied by purulent discharge. There were statistically significant differences in rates of isolation among clinical groups. Mycoplasma bovigenitalium was isolated from 7.7% and 20% of cows with moderate or acute vulvitis respectively but not from normal cows. Haemophilus somnus was isolated from 25% of cows with acute vulvitis. There were no significant differences in isolations of Escherichia coli, Corynebacterium pyogenes and alpha-hemolytic streptococcus between normal and clinically affected animals. Cultures of 135 repeat samples from 33 cows revealed that ureaplasma persisted in some animals for at least three months. No viruses were isolated from any of the animals in this study.

Experimental animal infections with Mycoplasma hominis and Ureaplasma urealyticum

Subcutaneous tissue cavities in mice and guinea pigs were infected with human isolates of Ureaplasma urealyticum and Mycoplasma hominis. The minimal infective dose for M. hominis was as low as less than 10 color-changing units (CCU) for mice and 10(2) CCU for guinea pigs. The minimal infective dose for U. urealyticum was as low as less than 10 CCU for mice and 10(4) CCU for guinea pigs. Mouse infections with either U. urealyticum or M. hominis persisted for 1 day to greater than 4 months. Guinea pigs remained infected for up to 4 weeks. Two M. hominis isolates were similar in their ability to infect subcutaneous tissue cavities but two U. urealyticum isolates varied in their ability to infect the cavities. The histopathology of the M. hominis and U. urealyticum infections was similar: an initial intense polymorphonuclear response with giant cells, followed in 4 weeks by histiocytes and giant cells with some plasma cells and lymphocytes.

Growth and effects of ureaplasmas (T mycoplasmas) in bovine oviductal organ cultures

Ureaplasmas isolated from the human genital tract and from the genital and respiratory tracts of cattle were grown in association with organ cultures of bovine oviduct (uterine tube). All strains of unreaplasmas multiplied in organ cultures, stopped ciliary activity, and caused histological lesions. Most strains grew well, and 10(8) to 10(9) color-changing units were determined 18 to 144 h after inoculation. Twenty-four to 144 h after inoculation with unreaplasmas, ciliostasis was complete. Ciliostasis was also caused by additions of nonviable cultures at pH 8.8 (or adjusted to 7.4) or washed disrupted cells (100 mug of protein/ml); it occurred in 48 to 96 h. The cilia-stopping effect of nonviable cultures was diminished by heating (56 C for 30 min) and was abolished by boiling. When added to fresh medium in amounts exceeding 25%, nonviable unreaplasmal cultures completely inhibited ureaplasmal growth. By light, scanning, and transmission electron microscopy, cilia-stopping effect was correlated with collapse and sloughing of the cilia (the initial lesion was "bent" cilia), with bulging and vacuolization of secretory and ciliated cells, and finally with disorganization of the epithelium, necrosis, and desquamation.

Presence of a dialysable fraction in normal bovine whey capable of killing several species of bovine mycoplasmas

Most normal bovine whey samples contain a fraction that survives heating at 56 degrees C. for 30 min., passes through a dialysis membrane and kills a maximum of seven out of ten of the different bovine mycoplasma species tested. Some whey samples appear more active than other but not all affect the same strains of mycoplasma indicating some specificity in their action. Absorption of the active factor from whey by heterologous and homologous mycoplasmas and by erythrocytes was observed. Binding of the factor to mycoplasmas appears to be temperature-dependent and non-specific, but subsequent mycoplasmacidal action shows some specificity.

Mycoplasmacidal activity of bovine milk for T-mycoplasmas

Normal bovine milk and whey was mycoplasmacidal for 6 of the 13 strains of bovine T-mycoplasmas examined. The in vitro assay used also demonstrated no killing of the human, canine and simian T-mycoplasma strains after 4 hr. incubation. However, there appeared to be some cow-to-cow variation in possession of this activity, and following E. coli endotoxin stimulation of the mammary gland the activity was considerably reduced.Whey from three normal cows was fractionated on a Bio-Gel A 1.5 m. column and the mycoplasmacidal activity of the resulting five peaks assayed. Only the second peak, peak B, contained activity and was characterized as the only peak containing bovine IgA. The active component in whey, however, was found to be heat stable at 60 degrees C. for 60 minutes and to pass through a dialysis membrane. This is inconsistent with it being immunoglobulin.

The persistence of mycoplasmas in the urogenital tract of men in the Antarctic

A series of meatal swabs, taken from 17 men over a period of 17 months during their tour at an Antarctic base was examined for mycoplasmas. The number of organisms isolated never exceeded 10(4) and not every specimen from each man yielded mycoplasmas. Nevertheless, Mycoplasma hominis was isolated from 71% and T-mycoplasmas from 59% of the men at some time during their stay. M. hominis persisted in the presence of serum IHA antibody titres of 1/64. Three subjects yielded only M. hominis and one only T-mycoplasmas.Six men had already spent a year at the base when the study began and mycoplasmas were still being isolated from some of them at the end of a 31 month period of isolation. The persistence of mycoplasmas in the male genital tract can therefore be independent of sexual contact. Two modes of persistence are suggested; either a few men act as carriers and reinfect the others by contaminating their environment, or as seems more likely, most men have chronic infections.

Immunity in experimental T-mycoplasma mastitis

Immunity to reinfection with the homologous T-mycoplasma strain has been demonstrated in the bovine mammary gland. This immunity was generalized throughout the udder and was not confined to previously infected quarters. Two out of three cows which were immune to reinfection with the homologous strain were not immune to reinfection with a serologically distinct T-mycoplasma strain. Animals varied in their ability to resolve experimental mastitis with T-mycoplasmas: those which resolved the initial infection without antibiotic therapy were immune to challenge with the homologous strain, but those which needed to be given antibiotics to clear the first infection were not all immune to such challenge.