Four virgin heifers were experimentally inoculated intravaginally with 7 X 10(6) Tritrichomonas foetus, and 2 heifers served as uninfected controls. The durations of infection were 13, 20, 21, and 28 weeks, respectively. An ELISA that used whole T foetus antigen was used to detect anti-T foetus immunoglobulins (IgA, IgG1, IgG2, and IgM) in vaginal, cervical, and uterine secretions, and sera during the course of infection. The vaginal and cervical antibody responses were characterized by significantly increased T foetus-specific IgA and IgG1 at 7 to 9 weeks of infection, whereas uterine IgA and IgG1 responses peaked at 10 to 12 weeks. The antibody response in serum was predominantly of the IgG1 and IgG2 subclasses. In all reproductive tract regions, IgA persisted at least until the time of T foetus clearance, and usually longer. The next most persistent isotype was IgG1, lasting longest in the vagina, then cervix, and for the shortest time in the uterus. In local secretions, IgG2 was seen only transiently, increasing at weeks 13 to 15 in the vagina, and at weeks 10 to 12 in the cervix. Little IgM, relative to that present before infection, was detected in any secretion or serum, although cervical secretions had the greatest amount. Eight to 12 weeks after clearance, the 4 experimental heifers were inoculated intravaginally with 1 x 10(5) T foetus, transient infections (2 to 3 weeks' duration) were established in only 2 of 4 heifers, as determined by culturing of reproductive tract secretions. The lag times of antibody responses during this reinfection were shorter than in the initial infection, and ELISA optical densities were at least as high as during the primary infection, suggesting an anamnestic response.

Vaginal aerobic bacterial flora was studied in 5 healthy bitches before, during, and after a 10-day period of treatment with ampicillin and an equally long period of treatment with trimethoprim-sulfamethoxazole. Blood variables and antimicrobial drug susceptibility also were studied. Bacteria were isolated from all bitches before the first treatment period. Bitches from which only a sparse number of bacteria were isolated had flora that varied from day to day. In most instances when bitches were given an antibiotic to which their vaginal bacterial flora was susceptible, these bacteria were eradicated after only 1 day of treatment. This was true for pasteurellae, streptococci, and, in all but one case, Escherichia coli. Staphylococcus intermedius was more difficult to eradicate, and, although susceptible in vitro, it was unaffected by antibiotic treatment in 1 bitch and it took 7 days to eradicate in another. Eradication of aerobic bacteria in the vagina was total only in the bitch that had sparse flora from the beginning. Bacteria colonized within 0 (in 4/5 bitches) to 4 days after termination of treatment with ampicillin and within 0 (in 4/5 bitches) to 3 days for trimethoprim-sulfamethoxazole. Mycoplasmas emerged during and after both treatment periods, and E coli became apparent during treatment with trimethoprim-sulfamethoxazole. Because mycoplasmas may be genital pathogens in bitches and E coli is a common uropathogen, their appearance should be an argument against widespread use of antibiotics in healthy breeding bitches. Two bitches developed a vaginal discharge during treatment or shortly after. Blood variables did not change during the study, nor did antimicrobial drug resistance of the isolated bacteria.

Vaginal aerobic bacterial flora was studied in 5 healthy bitches before, during, and after a 10-day period of treatment with ampicillin and an equally long period of treatment with trimethoprim-sulfamethoxazole. Blood variables and antimicrobial drug susceptibility also were studied. Bacteria were isolated from all bitches before the first treatment period. Bitches from which only a sparse number of bacteria were isolated had flora that varied from day to day. In most instances when bitches were given an antibiotic to which their vaginal bacterial flora was susceptible, these bacteria were eradicated after only 1 day of treatment. This was true for pasteurellae, streptococci, and, in all but one case, Escherichia coli. Staphylococcus intermedius was more difficult to eradicate, and, although susceptible in vitro, it was unaffected by antibiotic treatment in 1 bitch and it took 7 days to eradicate in another. Eradication of aerobic bacteria in the vagina was total only in the bitch that had sparse flora from the beginning. Bacteria colonized within 0 (in 4/5 bitches) to 4 days after termination of treatment with ampicillin and within 0 (in 4/5 bitches) to 3 days for trimethoprim-sulfamethoxazole. Mycoplasmas emerged during and after both treatment periods, and E coli became apparent during treatment with trimethoprim-sulfamethoxazole. Because mycoplasmas may be genital pathogens in bitches and E coli is a common uropathogen, their appearance should be an argument against widespread use of antibiotics in healthy breeding bitches. Two bitches developed a vaginal discharge during treatment or shortly after. Blood variables did not change during the study, nor did antimicrobial drug resistance of the isolated bacteria.

The reproductive tracts have an intimate relationship with reproduction because there are bacterial communities that can affect reproductive health. The differences in the bacterial community of periparturient dairy cows were investigated. Vaginal and fecal samples were collected seven days before and after calving, and DNA was extracted to sequence the V3-V4 regions of the 16S rRNA genes. In the postpartum vaginas, operational taxonomic units, Chao1, Shannon, and Simpson were decreased, and phyla Fusobacteria and Bacteroidetes were increased. In summary, bacterial abundance can affect the periparturient biological differences in dairy cows, suggesting a susceptibility to infection within one week after calving.

The Cooper isolate of bovine herpesvirus-1, which causes abortion in cattle, was used to construct a thymidine kinase-negative (TK-) deletion mutant virus. Twelve heifers were inoculated IV at 25 to 29 weeks of pregnancy with either TK- or thymidine kinase-positive (TK+) Cooper virus. All heifers developed fevers of 1 to 2 C during the first week after inoculation. Temperatures of TK+ inoculates were slightly higher and remained above normal a few days longer than in TK- inoculates. Viremia was detected in 5 of 6 TK+ inoculates and in all 6 TK- inoculates. More virus isolations were made from nasal and vaginal swab specimens of TK+ inoculates than from swab specimens of TK- inoculates. All heifers developed virus neutralizing antibody within 14 days after inoculation and antibody titers were similar between the 2 groups. None of the TK- inoculated heifers aborted and their calves did not have neutralizing antibody at birth. Abortion occurred in 5 of 6 heifers given TK+ virus. All aborted fetuses were infected with bovine herpesvirus-1, as demonstrated by virus isolation or detection of viral antigen in fetal tissues. These results indicate that inactivation of the TK gene reduces abortifacient activity of bovine herpesvirus-1.

Thirty-five heifers were allotted to 3 groups. Group 1 (contro]) consisted of 10 heifers that were not vaccinated and were challenge exposed by breeding to infected bulls. Group 7 (natural challenge exposure) consisted of 10 heifers that were vaccinated and challenge exposed by breeding to infected bulls. Group 3 (experimental challenge exposure) consisted of 15 heifers that were vaccinated and challenge exposed by breeding to infected bulls and by intravaginal inoculation with 10(7) Tritrichomonas foetus. Total immunoglobulin concentrations and specific trichomonal antibodies were determined in serum and vaginal secretions of heifers, using radial immunodiffusion and ELISA procedures. Control heifers remained infected for a mean of 10.6 weeks (range, 0 to 18 weeks), and heifers of the natural and experimental challenge-exposure groups remained infected for 3.2 and 5.0 weeks, respectively (range, 0 to 12 weeks). Total serum and cervicovaginal mucus concentrations of IgM, IgA, IgG1, and IgG2 did not change significantly after vaccination or challenge exposure. However, ELISA titers of total trichomonal antibodies increased up to 1:10,000 (range, 1:400 to 1:10,000) in serum after vaccination, and increased approximately tenfold above background in cervicovaginal mucus. In serum, the predominant trichomonal antibody isotype was IgG1, although trichomonal IgA and IgM antibodies also increased. The predominant trichomonal antibody detected in cervicovaginal mucus was IgA. Antibody titers in serum and cervicovaginal mucus of vaccinated heifers were not increased by infection. However, in control heifers, the total local trichomonal antibody response increased three- to fivefold after infection. In these heifers, specific antibodies in serum were predominantly IgG1 and local (cervicovaginal) antibodies were predominantly IgA.

The aerobic bacterial flora of the genital tract was characterized in 59 bitches in an 18-month study. The bitches represented 4 breeds and were from 3 kennels. Collection of vaginal swab specimens for bacterial culturing was performed every month, except during estrus when specimens were collected every week (n = 826). The capsule of the swab containing transport media was broken before specimen collection to moisten the tip, which helped to reduce the number of negative cultures. All bitches whelped at least once during the study and, thus, had known reproductive functions. Pregnancy rates, litter sizes, and pup mortality were within normal limits. Pasteurella multocida, beta-hemolytic streptococci group G, and Escherichia coli were the most common bacteria isolated. Although these species generally were isolated from mixed cultures, pure cultures were obtained from 18% of the specimens. There was a tendency for the various breeds to differ in their vaginal bacterial flora. The flora also varied during the reproductive cycle. Pasteurella multocida was isolated significantly more often during proestrus, estrus, metestrus, and pregnancy, than during anestrus and the postpartum period, and beta-hemolytic streptococci were isolated significantly more often during proestrus than during estrus, pregnancy, or the postpartum period. Staphylococcus intermedius was almost exclusively found after parturition. Culture results were negative for only 5.2% of specimens cultured. On the basis of our findings, bacterial culturing of vaginal swab specimens from bitches without signs of genital disease is of little value.