Rat Strains Differ in Susceptibility to Maternal and Fetal Infection with Mycoplasma pulmonis (original) (raw)
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Fetal Wastage as a Consequence of Mycoplasma Pulmonis Infection in Mice
Reproduction, 1975
The effect of Mycoplasma pulmonis, strain JB, on the outcome of pregnancy in TO mice was studied. The mice were infected intravenously before or after mating and the fetuses were examined at autopsy just before parturition. An increase in the number of abnormal pregnancies was noted in mice infected about 2 weeks before mating, and there was a significant increase in the number of fetuses which died midway through pregnancy. Mycoplasmas were not isolated from any of the fetuses although the organisms reached the joints of the pregnant mice and caused arthritis. It is possible, therefore, that maternal upset was a factor in these abnormal pregnancies. In mice infected at various times after mating, abnormal pregnancies were most frequently seen in those infected 9 days after mating. There was an increase in the number of both mid-and late-stage fetal deaths in these mice and also an increase in the number of late-stage fetal deaths in mice infected 5 days after mating. Mycoplasmas were isolated not only from most ofthe dead fetuses but also from living ones which suggests that in most instances death was probably due to maternal infection and disturbance rather than fetal infection per se. The possibility of modifying this mouse model by establishing a chronic genital tract infection is discussed as a means of investigating the r\l=o^\leof mycoplasmas in human abortion.
The susceptibility of germ-free, oestradiol-treated, mice to Mycoplasma hominis
Journal of Medical Microbiology, 1989
Conventionally reared female BALB/c mice, rendered susceptible to Mycoplasma horninis infection of the genital tract by treatment with oestradiol, have increased numbers of endogenous vaginal bacteria. The latter was reflected by the occurrence of bacterial growth in 95 (65.5%) of 145 cultures undertaken to isolate M. hominis from oestradiol-treated mice, but in only seven (4.8%) of 146 cultures from untreated animals. In addition, larger numbers of bacteria were seen in vaginal smears from oestradiol-treated mice than from untreated ones. Furthermore, abscesses developed in the genital region of 27 (1 7%) of 155 oestradiol-treated mice but in none of 50 that were untreated. However, such proliferation of the endogenous vaginal bacteria was not necessary for colonisation of the vagina by M. hominis. This was determined by showing that six germ-free, oestradiol-treated BALB/c mice given 2.5 x lo5 ccu of M. hominis intravaginally became colonised vaginally for at least 14 days, with multiplication and spread of the organisms to the upper genital tract and elsewhere, whereas six similar untreated mice given the same inoculum remained uninfec ted.
American Journal of Reproductive Immunology, 2007
ProblemPreterm, premature rupture of membranes (PPROM) is a dire pregnancy outcome that is frequently associated with infection by the genital mycoplasmas, Mycoplasma hominis, Ureaplasma parvum, and U. urealyticum. One potential mechanism by which these microorganisms may cause PPROM is by increasing the concentration of matrix metalloproteinases (MMPs) in the membranes and amniotic fluid. We tested this hypothesis in a well-defined model system of genital infection with M. pulmonis, a natural reproductive pathogen of rats.Preterm, premature rupture of membranes (PPROM) is a dire pregnancy outcome that is frequently associated with infection by the genital mycoplasmas, Mycoplasma hominis, Ureaplasma parvum, and U. urealyticum. One potential mechanism by which these microorganisms may cause PPROM is by increasing the concentration of matrix metalloproteinases (MMPs) in the membranes and amniotic fluid. We tested this hypothesis in a well-defined model system of genital infection with M. pulmonis, a natural reproductive pathogen of rats.Method of studyTimed-pregnant, specific pathogen-free, Sprague–Dawley rats were infected with 107 CFU M. pulmonis at gestation day (gd) 14. Controls received an equivalent volume (100 μL) of sterile medium. At gd 18, rats were euthanized, and membranes and amniotic fluids were harvested and stored at −70°C until analysis. Proteinase activity of amniotic fluid and membranes was resolved on discontinuous 7.5% sodium dodecyl sulfate–polyacrylamide gel electrophoresis gelatin zymography gels. Band intensity was determined using a digital gel documentation system and the manufacturer's software (Kodak).Timed-pregnant, specific pathogen-free, Sprague–Dawley rats were infected with 107 CFU M. pulmonis at gestation day (gd) 14. Controls received an equivalent volume (100 μL) of sterile medium. At gd 18, rats were euthanized, and membranes and amniotic fluids were harvested and stored at −70°C until analysis. Proteinase activity of amniotic fluid and membranes was resolved on discontinuous 7.5% sodium dodecyl sulfate–polyacrylamide gel electrophoresis gelatin zymography gels. Band intensity was determined using a digital gel documentation system and the manufacturer's software (Kodak).ResultsGelatinolytic activity associated with a band similar in molecular weight to ProMMP-9 (92 kDa, the inactive precursor of MMP-9) was significantly increased in amniotic fluids and membranes harvested from M. pulmonis-treated pups at gd 18 when compared with tissues harvested from control pups. Both ProMMP-9 and ProMMP-2 (72 kDa, the inactive precursor of MMP-2) were increased in infected animals at gd 21.Gelatinolytic activity associated with a band similar in molecular weight to ProMMP-9 (92 kDa, the inactive precursor of MMP-9) was significantly increased in amniotic fluids and membranes harvested from M. pulmonis-treated pups at gd 18 when compared with tissues harvested from control pups. Both ProMMP-9 and ProMMP-2 (72 kDa, the inactive precursor of MMP-2) were increased in infected animals at gd 21.ConclusionOur study suggests that the genital mycoplasmas can increase MMP-9 production in vivo.Our study suggests that the genital mycoplasmas can increase MMP-9 production in vivo.
Evaluation of Toxoplasma gondii placental transmission in BALB/c mice model
Experimental Parasitology, 2009
Toxoplasma gondii infection is common worldwide and highly important to pregnant women as it can be transmitted to the fetus via the placenta. This study aimed at evaluating the prevention of placental transmission in two different strains after chronic infection with each one of the strains. A BALB/c mice model was inoculated 30 days before breeding (immunization) and re-infected 12 and 15 days after pregnancy (challenge). Seven experimental groups were assayed: G1: ME49-immunization (type II), M7741-challenge (type III); G2: M7741-immunization, ME49-challenge; G3, ME49-immunization; G4: M7741-immunization; G5: ME49-challenge; G6: M7741-challenge; G7: saline solution inoculation. Serology, mouse bioassay, PCR and RLFP of the uterus, placenta and fetus were performed to determine the congenital transmission of the strains challenged after chronic infection. IgG T. gondii antibodies were detected in G1, G2, G3 and G4, but not in G5, G6 and G7. All animals of G5 and G6 were IgM-positive. Congenital infection was not detected by bioassay and PCR. Nonetheless, placentas from G3 and G4 resulted positive but no corresponding fetal infection was detected. G1 and G2 did not show the genotype of the strain challenged during pregnancy, only those of chronic infection. Thus, the chronically infected BALB/c mice showed no re-infection after inoculation with another strain during pregnancy. Further studies with different parasite loads and different mice lineages are needed.
Neospora caninum: chronic and congenital infection in consecutive pregnancies of mice
Veterinary Parasitology, 2016
Neospora caninum, the causative agent of bovine neosporosis is the major cause of abortion in cattle worldwide. The principal route of transmission is via in utero infection of the offspring. Congenitally-infected dams remain persistently infected for life and might undergo abortions in consecutive pregnancies. In the present study, the effect of N. caninum in chronic and congenital infection was examined. CD1 mice were infected intra-peritoneally with live tachyzoites of the NcIs491 isolate, while non-infected mice served as a control. There were no clinical signs of infection observed following inoculation, but high titers of specific anti-N. caninum antibodies were detected. A month after infection, when chronic-infection was established, mice were mated. Fertility, litter size and mortality rate were monitored within two generations of four consecutive pregnancies. During a nine months period of the study all females maintained high level of antibodies, while the non-infected control mice remained seronegative. There was no difference in the fertility rate of the dams, or in the litter size of infected and control mice. Mortality of offspring of the first and second generations of the infected dams was observed within the two first weeks of life. The vertical transmission was analyzed by PCR assay of offspring brains. PCR positive results were found in all 13 litters of the first generation tested during four consecutive pregnancies. The rate of vertical transmission slightly decreased in successive pregnancies being 74.2%, 59.5%, 48.1% and 40% for the first to fourth pregnancies respectively. In the second generation 21 out of 28 litters were found positive and the overall rate of vertical transmission was 28.5%. In chronically and congenitally infected dams N. caninum infection was maintained during all successive pregnancies for about 9 months. The results show that CD-1 outbred mice are a suitable model for studying chronic and congenital neosporosis.
Inflammatory competence of fetal rat
Inflammation, 1989
Using crossed immunoelectrophoresis, immunoelectrodiffusion, autoradiography, and equilibrium binding techniques, we demonstrate that the rat fetus, directly challenged in utero at 18 days by a single subcutaneous turpentine injection, presents a complex acute-phase plasma inflammatory response. A number of fetal serum proteins, 48 h after the injection, increase in concentration by factors of about 2–5. These positive acute-phase reactants (APR) areα 1-acute-phase globulin (α 1-AP),α 2-macroglobulin (α 2-M),α 1-acid glycoprotein (α 1-AG), haptoglobin (Hp), and hemopexin (Hpx). A number of proteins decrease, behaving like negative APRs. These are albumin,α 1-fetoprotein (AFP), transferrin, GHR-P63, thyroxine-binding prealbumin (TBPA), and transcortin (CBG). The marked fall in concentration of two of the high-affinity hormone-binding proteins of the fetal rat, i.e., the estrophilic AFP and TBPA, induce significant decreases (by 25–40%) of the estrogen- and thyroxine-binding abilities of the fetal serum. While the plasma inflammatory response of the fetus is qualitatively similar to that of the adult, the fetal reactions are, as a rule, quantitatively weaker. The characteristics of the plasma inflammatory response of the fetus are discussed in relation to the highly dynamic state of its development.
Acta Parasitologica, 2011
Neospora caninum is transmitted from a cow to its foetus by vertical transmission and the timing of infection in gestation is an important factor in determining the disease outcome. Few studies have explored the role of the placenta in the outcome of N. caninum infection during pregnancy. Here, we described the N. caninum presence, parasite load, local immune response, and histopathological lesions at the materno-foetal interface after infection of BALB/c mice at early and late stages of gestation. In mice infected at early gestation, N. caninum DNA was detected in foetoplacentary units 7 days post-infection (PI) and in the placenta, but not in viable foetuses on day 14 PI, indicating that the parasite was multiplying primarily in the placental tissues without reaching the foetus. Moreover, parasite DNA was detected in resorptions, suggesting that foetal death could be a consequence of infection. An increase in IFN-γ, TNF-α and IL-10 expression was observed in N. caninum PCR-positiv...