Bromothymol blue broth: improved medium for detection of Ureaplasma urealyticum (T-strain mycoplasma)

Modified real-time PCR for detecting, differentiating, and quantifying Ureaplasma urealyticum and Ureaplasma parvum

We evaluated a previously described quantitative real-time PCR (qPCR) for quantifying and differentiating Ureaplasma parvum and U. urealyticum. Because of nonspecific reactions with Staphylococcus aureus DNA in the U. parvum PCR, we developed a modified qPCR and designed new primers. These oligonucleotides eradicated cross-reactions, indicating higher specificity. The detection limits of the qPCR were determined at 1 and 3 colony-forming units/ml for U. parvum and U. urealyticum, respectively. The quantification limits of the assay for both Ureaplasma species ranged from 2.10(6) to 2.10(1) copy numbers per PCR. A total of 300 patient samples obtained from the lower genital tract were tested with this newly designed qPCR assay and compared with culture results. Of the samples, 132 (44.0%) were culture positive, whereas 151 (50.3%) tested positive using qPCR. The U. parvum and U. urealyticum species were present in 79.5% and 12.6% of the qPCR-positive samples, respectively. Both species were found in 7.9% of those samples. Quantification of U. parvum and U. urealyticum in the samples ranged from less than 2.5 × 10(3) to 7.4 × 10(7) copies per specimen. In conclusion, the modified qPCR is a suitable method for rapid detection, differentiation, and quantification of U. parvum and U. urealyticum.

Ureaplasma parvum as a cause of sternal wound infection

Few reports in the literature have documented the isolation of Ureaplasma species from sternal wounds. A case of sternal wound infection likely due to Ureaplasma parvum is described. When routine bacterial cultures from a sternal wound infection fail to yield a pathogen, diagnostic testing for mycoplasmas and ureaplasmas should be considered.

A novel mouse model of Ureaplasma-induced perinatal inflammation: effects on lung and brain injury

Chorioamnionitis is associated with increased lung and brain injury in premature infants. Ureaplasma is the microorganisms most frequently associated with preterm birth. Whether Ureaplasma-induced antenatal inflammation worsens lung and brain injury is unknown. We developed a mouse model combining antenatal Ureaplasma infection and postnatal oxygen exposure. Intraamniotic Ureaplasma Parvum (UP) increased proinflammatory cytokines in placenta and fetal lungs. Antenatal exposure to UP or broth caused mild postnatal inflammation and worsened oxygen-induced lung injury. Antenatal UP exposure induced central microgliosis and disrupted brain development as detected by decreased number of calbindin-positive and calretinin-positive neurons in the neocortex. Postnatal oxygen decreased calretinin-positive neurons in the neocortex but combined with antenatal UP exposure did not worsen brain injury. Antenatal inflammation exacerbates the deleterious effects of oxygen on lung development, but the broth effects prohibit concluding that UP by itself is a compounding risk factor for bronchopulmonary dysplasia. In contrast, antenatal UP-induced inflammation alone is sufficient to disturb brain development. This model may be helpful in exploring the pathophysiology of perinatal lung and brain injury to develop new protective strategies.

Production of recombinant antigens of Ureaplasma parvum serotypes 3 and 6 for development of a serological assay

Recombinant antigens of Ureaplasma parvum serotypes 3 and 6 were produced in order to develop a serological assay for Ureaplasma antibody detection. The genes of the multiple banded antigen (MBA) were amplified by PCR and cloned in a pTrcHis TOPO plasmid. Purified recombinant proteins were evaluated in Western blotting and enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies and human sera. Our approach was successful in the production of the recombinant MBAs (rMBAs) for serotypes 3 and 6. The antigens tested positive with serotype-specific monoclonal antibodies in Western blotting and in ELISA. Prominent reactions were detected with the rMBAs and their homologous monoclonal antibodies. Strong cross-reactions were visible in ELISA between rMBA 3 and the monoclonal antibodies from the other U. parvum serotypes. A weak cross-reaction was seen with rMBA 3 and the monoclonal antibody from serotype 4. rMBA 6 showed cross-reaction only with the monoclonal antibody from U. parvum serotype 1. Fifty-one percent of the sera obtained from culture-positive women reacted with one or both rMBAs. Only three (15%) of the sera from culture-negative women reacted with the rMBA. The positive reactions were observed only with rMBA 6. These preliminary tests showed the potential usefulness of the rMBAs produced for detecting an antibody response against Ureaplasma antigens.

Molecular characterization of thymidine kinase from Ureaplasma urealyticum: nucleoside analogues as potent inhibitors of mycoplasma growth

Ureaplasma urealyticum (U. urealyticum), belonging to the class Mollicutes, is a human pathogen colonizing the urogenital tract and causes among other things respiratory diseases in premature infants. We have studied the salvage of pyrimidine deoxynucleosides in U. urealyticum and cloned a key salvage enzyme, thymidine kinase (TK) from U. urealyticum. Recombinant Uu-TK was expressed in E. coli, purified and characterized with regards to substrate specificity and feedback inhibition. Uu-TK efficiently phosphorylated thymidine (dThd) and deoxyuridine (dUrd) as well as a number of pyrimidine nucleoside analogues. All natural ribonucleoside/deoxyribonucleoside triphosphates, except dTTP, served as phosphate donors, while dTTP was a feedback inhibitor. The level of Uu-TK activity in U. urealyticum extracts increased upon addition of dUrd to the growth medium. Fluoropyrimidine nucleosides inhibited U. urealyticum and M. pneumoniae growth and this inhibitory effect could be reversed by addition of dThd, dUrd or deoxytetrahydrouridine to the growth medium. Thus, the mechanism of inhibition was most likely the depletion of dTTP, either via a blocked thymidine kinase reaction and/or thymidylate synthesis step and these metabolic reactions should be suitable targets for antimycoplasma chemotherapy.

Development of an enzyme-linked immunosorbent assay for serotyping ureaplasma urealyticum strains using monoclonal antibodies

Ureaplasma urealyticum comprises 14 serotypes. The existing serotyping methods all use polyclonal antibodies. These methods are time-consuming and labor-intensive, and they cannot always be performed on primary isolates; in addition, the results are difficult to interpret. We developed a new enzyme-linked immunosorbent assay (ELISA) method using serotype-specific monoclonal antibodies (MAbs) to enable the serotyping of U. urealyticum isolates from primary broth cultures. Each of the 14 serotype reference strains was tested against 14 selected MAbs. Homologous reactions were very strong, while heterologous reactions were negligible. Three cross-reactions were observed: MAb 5 cross-reacted with serotype 2, MAb 14 cross-reacted with serotype 3, and MAb 8 cross-reacted with serotype 13. Despite the cross-reactions observed, all the serotype reference strains of U. urealyticum could be identified and differentiated using a combination of MAbs. Reproducibility was analyzed with a fractionated antigenic preparation and with several freshly prepared antigens of the same strain. No significant interrun variation was found with the fractionated antigen, but significant variations in optical density (OD) values were found when freshly prepared antigens were tested. However, the variation in OD values did not influence the overall interpretation of the ELISA: reactions with homologous MAbs were always prominent compared to those of the negative controls. This newly developed ELISA using MAbs seems promising for serotyping of U. urealyticum clinical isolates.

Development of monoclonal antibodies against Ureaplasma urealyticum serotypes and their use for serotyping clinical isolates

Monoclonal antibodies (MAbs) against Ureaplasma urealyticum serotype 2, 5, 7, 8, 10, 11, 12, and 13 reference strains were developed. The reactivities of these MAbs with the 14 serotype reference strains was verified by colony immunofluorescence assay and Western blot assay. MAbs against serotypes 2, 7, 10, 11, and 12 were serotype specific, whereas MAbs against serotypes 5, 8, and 13 showed cross-reactivity. All MAbs against serotype 5 were cross-reactive with serotype 2, and one showed, in addition, cross-reactivity to serotypes 9 and 10. Mutual cross-reactivities were observed between MAbs against serotypes 8 and 13. The usefulness of the MAbs for the serotyping of U. urealyticum strains was evaluated by serotyping 21 selected clinical isolates. A complete set of MAbs (the newly developed MAbs and the previously described MAbs against serotypes 1, 3, 4, 6, 9, and 14) as well as a complete set of polyclonal antibodies (PAbs), PAbs 1 to 14, were used. MAbs were able to identify 18 of 21 isolates including 2 isolates with mixed serotypes. Polyreactivity, which occurred with 19 of the 21 isolates with PAbs, was not observed by the use of MAbs. MAbs seem to be a more valuable tool than PAbs for serotyping and could help in investigating a possible link between the expression or variability of the serotype-specific antigens and pathogenicity.

Throat colonization of neonatal nursery staff by Ureaplasma urealyticum: An infection control or occupational health consideration?

Very low birth weight infants often have protracted respiratory tract colonization with Ureaplasma urealyticum. To determine whether prolonged contact with very low birth weight infants resulted in higher rates of upper respiratory tract colonization with this organism for caregivers, throat swabs for U urealyticum culture were obtained from medical, nursing and other support staff working in the neonatal intensive care and level II nurseries at the Health Sciences Centre and the St Boniface Hospital in Winnipeg, Manitoba. Throat colonization by U urealyticum was demonstrated in 7.3% (95% ci 0 to 15.6%) of 41 nurses working in the intensive care nurseries but in none of the 48 nurses working in other locations or the 66 other individuals tested (P=0.02). However, throat colonization was not significantly higher among the neonatal intensive care nurses than among the women delivering at one of the study institutions. Close contact with very low birth weight infants appears to constitute a minimal risk for increased throat colonization with U urealyticum among hospital staff members.

Polymerase chain reaction using 16S rRNA gene sequences distinguishes the two biovars of Ureaplasma urealyticum

Several fundamental phenotypic and genotypic differences have separated strains of the genital mycoplasma Ureaplasma urealyticum into two clusters or biovars. However, the lack of an easily performed and unambiguous test to discriminate between them has hampered investigation of the relationship between these biovars and disease. We determined the 16S rRNA nucleotide sequence of U. urealyticum 27, the serovar 3 standard and representative of the parvo biovar (serovars 1, 3, 6, and 14). This sequence was compared with the published sequence of U. urealyticum T960, which is the type strain and the serovar 8 standard and is representative of the T960 biovar which is composed of the 10 intervening serovars. Homology between the two sequences was 98.8%; differences were exploited to provide primers for biovar-specific polymerase chain reactions (PCRs). The results of these reactions placed all 14 serovar standard strains into the correct biovar. The PCRs were also applied to 10 cloned and 8 noncloned isolates that had been serotyped earlier. For 16 of them, we deduced their biovars from the serotyping data and then confirmed them by PCR. One unpredictable isolate and one nonserotypeable isolate were also classified as to biovar. Thus, we have developed a method for biotyping U. urealyticum that is applicable to both laboratory-adapted strains and wild-type isolates and that is appropriate for testing large numbers of clinical isolates. The amplification by the T960 biovar PCR protocol of DNAs from ureaplasmas of animals and certain Mycoplasma species suggested that the parvo biovar has diverged from the mainstream of the evolution of this clade.

Prevalence of Mycoplasma pneumoniae in subjectively healthy individuals

Subjectively healthy persons were investigated for the presence of Mycoplasma pneumoniae in throat cultures. During a peak period of M. pneumoniae incidence, 13.5% of 758 healthy volunteers were found to harbour the bacterium in the throat. The investigation was continued, and during a subsequent period of 11 months, the incidence of M. pneumoniae isolated decreased to 4.6% of 499 volunteers. All new blood donor sera 1990-1991 (422 sera) were screened for the presence of antibodies to M. pneumoniae; it was found that there was a fluctuating but significant number of individuals with positive serology based on a single test occasion.

Clinical and biological characteristics of Ureaplasma urealyticum induced polyarthritis in a patient with common variable hypogammaglobulinaemia

Persistent infectious polyarthritis caused by Ureaplasma urealyticum in a patient with common variable hypogammaglobulinaemia is described. The patient developed a symmetrical, destructive polyarthritis and tenosynovitis associated with a markedly depressed synovial fluid glucose concentration and characteristic soft tissue abscesses. The ureaplasma organism developed resistance to multiple antibiotics and persisted for five years. The organism was identified repeatedly in many joints by culture, confirmed by DNA hybridisation, and mycoplasma-like structures were shown in synovial tissues by electron microscopy.

Ureaplasma urealyticum urease genes; use of a UGA tryptophan codon

Nucleotide sequence analysis of a Ureaplasma urealyticum DNA fragment, homologous to cloned urease genes of other prokaryotes, revealed three consecutive open reading frames. The molecular weights of the three deduced polypeptides are 11.2 kD, 13.6 kD and 66.6 kD. These values are consistent with the size of the three subunits previously reported for purified native urease. A significant sequence homology was found between the three polypeptides of the ureaplasmal urease and the single polypeptide of jack bean (Canavalia ensiformis) urease. Codon usage indicates that UGA is a tryptophan codon in this mollicute. Use of polymerase chain reactions has disclosed the existence of genetic polymorphism among the urease genes of different serotypes of U. urealyticum.

Human ureaplasmas show diverse genome sizes by pulsed-field electrophoresis

Contour clamped homogeneous field (CHEF) agarose gel electrophoresis (AGE), ramped to give linear separation of DNA molecules of 600-1600 kilobase pairs (kbp), was used to determine mobilities for full-sized genomic DNA of the serotype standard strains of the human genital mollicutes, Ureaplasma urealyticum relative to yeast chromosomal DNA markers. Indicated genome sizes (in kbp) were 760 for the four biotype 1 strains and 840-1140 for eleven biotype 2 strains. Other estimates were: 720 for Mycoplasma hominis, 1070 for Mycoplasma hyopneumoniae, 890 for Mycoplasma flocculare, 1180 and 1350 for Mycoplasma mycoides subsp. mycoides Y and GC1176-2, respectively, and 1650 and 1580 for Acholeplasma laidlawii B and PG 8, respectively. These data supplement previous evidence from CHEF AGE that the genomes of the Mycoplasmataceae are diverse in size with some larger than previously estimated from DNA renaturation kinetics.

Single-dose oral cefixime versus amoxicillin plus probenecid for the treatment of uncomplicated gonorrhea in men

In this randomized study, a single 800-mg oral dose of cefixime cured 96 of 97 men with uncomplicated gonococcal urethritis, compared with 44 cures of 46 men who received standard therapy with amoxicillin (3 g) plus probenecid (1 g). Both regimens were ineffective against coexistent infection with Chlamydia trachomatis and Ureaplasma urealyticum. Cefixime was well tolerated, and all side effects were mild and self-limited.

A gene probe to detect Mycoplasma hyopneumoniae, the etiological agent of enzootic porcine pneumonia

Enzootic porcine pneumonia is caused by Mycoplasma hyopneumoniae. Since the disease is of world-wide importance it is important to detect and identify the causative agent. In experience laboratories this mycoplasma can usually be detected by culture but its identification still is difficult and time consuming. We have cloned random Eco R1 fragments of M. hyopneumoniae DNA to M13mp19 and used the resultant recombinant to produce a probe capable of detecting approximately 10 pg of the mycoplasma DNA (10(4) organisms). By using appropriate stringency the test was made specific for M. hyopneumoniae, although at lower stringency reaction was positive with Mycoplasma flocculare at 1000 x the concentration limit. The assay did not detect M. hyopneumoniae in DNA from lungs of chronically infected animals but it did react with DNA isolated from the organisms cultured from the infected lung material.

Postpartum bacteremia and placental colonization with genital mycoplasmas and pregnancy outcome

The influence of placental colonization and postpartum bacteremia with genital mycoplasmas on the course of delivery and the immediate postpartum period was evaluated in 511 women who gave birth to live infants of at least 26 weeks' gestation. Genital mycoplasmas were isolated from the placenta in 153 patients (29.9%) and from blood in four patients (0.8%). These four isolates were all Ureaplasma urealyticum. Patients with genital mycoplasmas isolated from the placenta were delivered of infants with birth weights and gestational ages similar to those of infants of patients who did not have genital mycoplasmas in the placenta (3260 gm and 39.2 weeks versus 3272 gm and 39.3 weeks). No adverse effects of maternal postpartum bacteremia with genital mycoplasmas were observed, either in the mother or in the baby. We conclude that, whereas genital mycoplasmas frequently can be isolated from the placenta, there is no evident relationship between the presence of genital mycoplasmas and pregnancy outcome. In a few instances U. urealyticum has been isolated from the blood of afebrile postpartum women. In these women the presence of this bacteria is probably related to the birth process. This bacteremia does not precede an infectious complication.

In vitro activity of antibiotics against Ureaplasma urealyticum and Chlamydia trachomatis strains from patients with nongonococcal urethritis

The activity of minocycline, doxycycline, tetracycline, erythromycin, mepartricin and lincomycin against 35 freshly isolated Ureaplasma urealyticum strains was tested. Doxycycline was the most active. Twelve strains were resistant to minocycline and four of these were sensitive to erythromycin. Mepartricin showed no activity against the organisms at a concentration of 10 micrograms/ml. The susceptibility of 30 low-laboratory-passage Chlamydia trachomatis strains against tetracycline and erythromycin was tested. A variable degree of sensitivity to tetracycline and erythromycin was found, the median MIC values being 0.13 micrograms/ml and 0.025 micrograms/ml respectively. No resistant Chlamydia trachomatis strain was found.

Serotypes of Ureaplasma urealyticum isolated from normal pregnant women and patients with pregnancy complications

To compare the distribution of Ureaplasma urealyticum serotypes 1 to 10 in different patient populations, the serotypes of 240 U. urealyticum strains from 207 patients were determined by the indirect immunofluorescence test by using U. urealyticum antisera 1 to 10. Strains were obtained from the following four patient groups: group 1, 24 couples in which the women had a history of recurrent spontaneous abortion; group 2, 25 patients who had their first spontaneous abortion; group 3, 14 pregnant patients with pregnancy complications (premature delivery, intrauterine death); and group 4, 138 patients with uneventful pregnancies. The serotypes most often found in these 207 patients were as follows: serotype 3, 52.2%; serotype 6, 30.3%; serotype 10, 11.4%; serotype 1, 9.5%; serotype 4, 6.5%; serotype 8, 6.5%. Serotypes 2, 5, 7, and 9 were found in less than 1% of the patients. More than one serotype was found in 16.9% of the patients. The overall distribution of the 10 serotypes in the different groups was similar, except for that of serotype 4. Serotype 4 was isolated from 20.8% of the patients in group 1 and from 5.1% of the patients in group 4 (P less than 0.01). Results of this study indicate that U. urealyticum serotype 4 can be isolated more frequently from patients with a history of recurrent miscarriages than from normal pregnant women.

Incidence and bacterial aetiology of neonatal conjunctivitis

Two hundred and twenty-nine infants born consecutively at the maternity ward of the Middelheim Hospital in Antwerp, over a period of 5 months, and an additional 55 randomly selected infants born at the same hospital were clinically and microbiologically investigated before leaving the maternity ward. All infants born at this maternity ward received argyrol eye drops immediately after birth. Twenty-six (11%) of the infants consecutively investigated had neonatal conjunctivitis diagnosed before leaving the maternity ward, where they stayed from 7-10 days. Another 29 infants were reported to have developed sticky eyes and/or red eyes after leaving the maternity hospital and before 1 month of age. The instantaneous risk of developing, a conjunctivitis was equal for each day of the first month of life. Chlamydia trachomatis was isolated from the eyes of 11 of the 229 (4.8%) consecutively born infants but only one had conjunctivitis symptoms before leaving the maternity ward. Overall one or more bacterial species could be isolated from the eyes of 143 (48%) of the infants, but only viridans streptococci and Staphylococcus aureus were cultured significantly more often from the eyes of cases with conjunctivitis than from the eyes of the infants without conjunctivitis (P less than 0.001).

ATP measurements obtained by luminometry provide rapid estimation of Ureaplasma urealyticum growth

ATP content obtained by luciferin-luciferase luminometry with commercially available reagents provided rapid estimates of Ureaplasma urealyticum populations. Each cell contained about 4.7 X 10(-18) mol of ATP. We could detect 10(4) CCU50 (color change unit50) per 100 microliters. We correlated urease activity with growth and confirmed the differential response of ureaplasma strains to Mn2+.

Effect of carbohydrates on growth of Ureaplasma urealyticum and Mycoplasma hominis

We examined the effect of 31 carbohydrates on the growth of Ureaplasma urealyticum and Mycoplasma hominis. Arbutin and its breakdown product, hydroquinone, inhibited growth of both species; the other substrates did not alter the extent of growth. Volatile and nonvolatile end products of carbohydrate metabolism were not detected by gas chromatography.

Recovery of microorganisms in semen and relationship to semen evaluation

Semen samples from 120 consecutive unselected men attending our fertility clinic were studied to determine the bacterial isolation rate of semen and its influence on semen quality. Each sample was cultured aerobically, anaerobically, and for Ureaplasma urealyticum and Mycoplasma hominis. The following were analyzed for each semen specimen: motility, morphologic features, and number of sperm cells and viscosity of the ejaculate. Four of the 120 samples had negative results; 101 cultures yielded one or more aerobic organisms (the majority with less than 20,000 microorganisms/ml); 26 yielded anaerobic organisms; and 40 yielded U. urealyticum. No single aerobic or anaerobic organism could be related to abnormal semen samples. Only the presence of U. urealyticum correlated significantly with abnormal semen samples (P less than 0.005). The most affected parameters were the number of spermatozoa (P less than 0.005) and motility (P less than 0.05). We conclude that routine aerobic and anaerobic bacterial cultures of semen are not useful in the clinical evaluation of male infertility. The usefulness of routine screenings for U. urealyticum must be investigated further.

Evaluation of Mycotrim-GU for isolation of Mycoplasma species and Ureaplasma urealyticum

The Mycotrim-GU (Hana Biologics, Berkeley, Calif.) biphasic culture system and a conventional system were compared for their ability to detect Ureaplasma urealyticum and Mycoplasma species in 100 clinical specimens. Both systems detected 18 Mycoplasma spp. isolates. The average colony detection time was 1.9 days with the Mycotrim-GU and 2.3 days with the conventional system. The Mycotrim-GU agar detected all 33 U. urealyticum isolates recovered in the study, and the conventional agar detected 31. In addition to the U. urealyticum isolates recovered from the agar, there were several specimens that, although they did not grow colonies on the agar, gave an alkaline broth change. Of these specimens, two were found with the conventional system and seven were found with the Mycotrim-GU. The average detection time of U. urealyticum colonies was 2.0 days for the conventional agar and 1.7 days for the Mycotrim-GU. The Mycotrim-GU offers several advantages over the conventional system: it is commercially available, consists of a one-flask system which is ready to use, has a significantly longer shelf life, and is cost competitive. This study showed the Mycotrim-GU to be an effective system for detecting the genital mycoplasmas.

The effect of Mycoplasma hominis and Ureaplasma urealyticum on hamster egg in vitro penetration by human spermatozoa

The effects of some genital mycoplasmas on the in vitro penetration of human spermatozoa into the master egg were studied. Ureaplasma urealyticum serotypes 4, 8, and 6 showed high interfering activity: 6.3% (P less than 0.01), 12.3%, and 14.5%, respectively, against the 55.6% penetration rate of untreated sperm. Neither a cytotoxic effect of mycoplasmas on gametes nor a masking of the binding sites on the egg surface were demonstrated. In experiments carried out with U. urealyticum serotype 4, the production of diffusible relatively heat-labile factor(s) responsible for the inhibition of sperm penetration was postulated.

Immunoglobulin A protease activity of Ureaplasma urealyticum

All of 14 serotype standards and 34 of 35 wild-type strains of Ureaplasma urealyticum isolated from humans demonstrated an immunoglobulin A (IgA) protease activity. This activity degraded radiolabeled human IgA including IgA1 but not IgG or azocasein. The IgA fragments were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by radioautography, and they had molecular weights of about 110,000 and 50,000. The IgA protease activity persisted in 25 mM EDTA but was sensitive to trypsin; it was presumed to be protein. This is the fourth microbial genus and the first myocoplasma species in which an IgA protease activity has been identified. Such activity was absent in Mycoplasma pneumoniae, Mycoplasma hominis, and Acholeplasma laidlawii.

Comparison of two methods for enumeration of mycoplasmas

Two methods of viable cell counts were evaluated for Mycoplasma hominis and Ureaplasma urealyticum: color change unit50 and colony-forming unit. The color change unit50 method gave higher estimates of cell numbers; furthermore, the color change unit50 values correlated better with the DNA content of the cell pellet and the published genome sizes.

Expanded serotyping scheme for Ureaplasma urealyticum strains isolated from humans

For the last decade the serological heterogeneity of strains of Ureaplasma urealyticum isolated from humans has been represented by eight serotypes. We have identified two additional serotypes, strains Vancouver and Western. Using a modified metabolic inhibition test and a colony indirect epifluorescence method, we tested antisera to the above 10 types against the 11 members of the independent Lin-Kass classification. Four of the latter, K2, U24, U26, and U38, showed unique specificities; these were confirmed by reciprocal testing with antisera prepared against the respective strains. With the addition of these strains, the serotyping scheme now has 14 members. Since this expanded classification allows greater discrimination between strains, it will allow also for their future characterization. It provides, in addition, a potentially more effective epidemiological tool.

Effect of gaseous conditions on isolation and growth of Ureaplasma urealyticum on agar

Five laboratory-adapted strains of Ureaplasma urealyticum showed comparable colony counts when incubated in eight gaseous environments including air, in different concentrations of carbon dioxide, and under anaerobiosis. For primary isolation on genital mycoplasma agar 95% N2-5% CO2 gave 100% correlation with growth in bromothymol blue broth, whereas certain strains failed to grow on agar incubated in air, the TABCO2 system (Lab-Tek Division, Miles Laboratories, Ltd., Rexdale, Canada), 100% CO2, or under anaerobiosis.

Standardized method for determining antimicrobial susceptibility of strains of Ureaplasma urealyticum and their response to tetracycline, erythromycin, and rosaramicin

We describe a method for determining the minimal inhibitory concentrations (MICs) of antibiotics for Ureaplasma urealyticum which is compatible with current standard of susceptibility testing. A presumptive MIC is available after 24 h of incubation, and the definitive MIC is available at 48 h. The MICs for 9 serotype strains and 27 clinical isolates ranged from less than or equal to 0.5 to 256 microgram of tetracycline per ml, greater than or equal to 1 to 64 microgram of erythromycin per ml, and 0.031 to 4.0 microgram of rosaramicin per ml. Of an additional 555 isolates screened for their response to tetracycline, 2% required MICs of greater than 64 microgram/ml, which we believe is near the concentration at which in vivo resistance to this agent is expressed. After prolonged exposure to rosaramicin, the resistance of two of three serotype strains of U. urealyticum was increased 8- and 16-fold, but the MICs still did not exceed 1.0 microgram/ml.

The use of glycylhistidyllysine in culture systems

Glycylhistidyllysine (GHL), a tripeptide isolated from plasma, has been shown to alter the growth rate of many cell types and organisms in culture systems. The tripeptide is optimally active at concentrations between 10 and 200 ng/ml. Some of the more interesting uses of GHL are highlighted in this paper. Present information suggests that GHL functions as a transporter of transition metals, in particular copper, to the cell surface for uptake into the cell.

Antimicrobial susceptibility of Ureaplasma urealyticum

An antimicrobial susceptibility test, a tow-tube broth dilution and disk elution method for Ureaplasma urealyticum, was modified to incorporate some of the standard procedures followed in traditional antimicrobial testing. The susceptibility pattern of the species was reevaluated by determining the effect of various antimicrobial agents on 21 vaginal isolates. All isolates were inhibited by tetracycline congeners (1 to 6 micrograms/ml) and killed by methenamine mandelate (0.6 mg/ml). All but one isolates were inhibited by erythromycin (0.4 to 3 micrograms/ml). Only eight isolates were inhibited by nalidixic acid (1 to 6 micrograms/ml), and seven were inhibited by nitrofurantoin (20 to 60 micrograms/ml), whereas all isolates were resistant to rifampin (1 microgram/ml) and trimethoprim-sulfamethoxazole (5 micrograms/ml). The in vitro technique described can readily be performed on individual patient isolates before the initiation of antimicrobial therapy.

Growth-modulating plasma tripeptide may function by facilitating copper uptake into cells

The plasma tripeptide glycyl-L-lysine (GHL), when added at nanomolar concentrations to a wide group of cultured systems, produces a disparate set of responses ranging from the stimulation of growth and differentiation to outright toxicity. Such diverse actions imply that this tripeptide mediates some basic biochemical function common to many types of cells and organisms. During the isolation of GHL we found the compound to co-isolate through a number of steps with approximately equimolar copper and about 1/5 molar iron. Maximal effects on hepatoma cells (HTC4) were seen when the peptide was added with copper and iron to the growth medium. Structure-function studies revealed that several tripeptides with a histidyl-lysyl linkage were nearly as active as GHL. The association of GHL with copper and a homology similarity between the tripeptide and the copper transport sites on albumin and alpha-fetoprotein, where the cupric atom is bound to a histidyl residue adjacent to a basic residue, suggested that GHL may act as a copper transport factor. We report here that the tripeptide readily forms complexes with copper(II) and enhances the uptake of the metal into cultured hepatoma cells.

Tetracycline in nongonococcal urethritis. Comparison of 2 g and 1 g daily for seven days

In a previous study treatment with minocycline 100 mg orally every day for seven days was as effective for nongonococcal urethritis (NGU) as 200 mg for seven days or 100 or 200 mg for 21 days. In this prospective, randomised study men with NGU received tetracycline either 500 mg or 250 mg four times daily for seven days. of 200 men initially enrolled, Chlamydia trachomatis was isolated from 40% and Ureaplasma urealyticum from 48%. Eight of 10 homosexual men compared with 39 (21%) of 190 bisexual or heterosexual men had negative culture results for both C trachomatis and U urealyticum (x2 = 15.5, P < 0.0005). U urealyticum was isolated more frequently from chlamydia-negative men and from men with 10 or fewer sex partners during their lifetime. Both regimens were equally effective in their in-vivo activity against C trachomatis and U urealyticum. Failure rates were similar with the two regimens. More obvious failure with purulent or profuse mucoid discharge and pyuria occurred more frequently with the 250-mg regimen (20% of 76 men on the 250-mg regimen compared with 7% of 67 men on the 500-mg regimen; x2 = 4.45, P < 0.05). Failure occurred more frequently in men who were initially chlamydia-negative and in men in whom U urealyticum persisted after medication. Thus, the 250-mg regimen appeared to be as effective as the 500-mg regimen in the initial treatment of NGU. However, one-third of men had persistent or recurrent urethritis with these regimens, and there is a need for antimicrobial agents with greater in-vivo activity, especially against chlamydia-negative NGU.

Ureaplasma urealyticum in the urethra of healthy men

Nineteen healthy married white men had samples of first-voided urine cultured for Ureaplasma urealyticum at weekly intervals for 17 consecutive weeks. Of these, 63% harboured U urealyticum in their urine on at least one occasion; in 40% of the men with positive culture results ureaplasmas were isolated from 90% of samples. Those men whose specimens were frequently culture-positive had notably higher titres for U urealyticum than those whose specimens were less frequently positive. There were no significant correlation between the number of leucocytes in the urinary sediment and the amount of U realyticum in the corresponding urine specimens, although ureaplasma-positive urine specimens tended to contain slightly more leucocytes than ureaplasma-negative samples. Fourfold or higher rises in titre of U urealyticum in urine samples was not associated with urethral signs or symptoms. One man with a presumably primary infection developed dysuria. Sixty-five strains of U urealyticum were serotyped, with types 2 and 3 predominating; the serotype found in each patient with fairly constant.

Growth-modulating tripeptide (glycylhistidyllysine): association with copper and iron in plasma, and stimulation of adhesiveness and growth of hepatoma cells in culture by tripeptide-metal ion complexes

The tripeptide H-Gly-His-Lys-OH (GHL) is a human plasma constituent which has been previously shown to modulate the growth and viability of a variety of cell types and organisms. Experimental observations presented herein indicate that GHL is complexed with the transition metal ions Cu++ and Fe++ in vivo and may exert its biological effects as a peptide-metal chelate. At physiological pH in vitro, GHL associates with ionic copper, cobalt, iron, molybdenum, manganese, nickel, and zinc, but has no affinity for calcium, manganese, potassium, and sodium. GHL acts synergistically with copper, iron, cobalt, and zinc to alter patterns of cell growth in monolayer cultures of a tumorigenic hepatoma cell line (HTC4). These transition metals induce cellular flattening and adhesion to support surfaces, and inhibit DNA synthesis and lactic acid production when growth is limited by reduction of serum concentrations in medium. These inhibitory effects are neutralized, and intercellular adhesion and growth are stimulated by GHL in medium at nanomolar concentrations. Cu and Fe are the most active metals when combined with GHL. The results suggest that the inability of HTC4 cultures to replicate without adequate concentrations of serum in medium may reflect deficiency of GHL and transition metals, which appear to form complexes prior to interaction with cells. Chelation of transition metals with GHL and, potentially, with other growth-modulating peptide factors in plasma or medium, may provide a mechanism for expression and regulation of biological activities influenced by transition metals and polypeptide growth factors. The observed effects of GHL-metal complexes, including stimulation of cellular adhesiveness to substratum (flattening) and intercellular attachment (monolayer formation), appear to satisfy requirements for growth of hepatoma cells in monolayer culture.

Modified metabolic inhibition test for serotyping strains of Ureaplasma urealyticum (T-strain Mycoplasma)

Antisera prepared against the eight recognized serotypes of Ureaplasma urealyticum were tested against the homologous and heterologous antigens by a modified metabolic inhibition test that used bromothymol blue broth in microtiter plates. The method gives clear endpoint determinations which are usually maintained on continued incubation. Antisera against serotype 8 showed cross-reactions with types 2 and 4. The ninth strain, Vancouver, when tested by this method did not fit the recognized serotyping scheme and may represent a new serotype.

Significance of appropriate techniques and media for isolation and identification of Ureaplasma urealyticum from clinical specimens

Controversy over the association of Ureaplasma urealyticum with reproductive failure may be due to methods used to isolate the microorganism. U. urealyticum isolations from clinical material should be done simultaneously in broth and on Shepard's differential agar medium (A7) containing manganese sulfate. Urine sediments result in a 9% (P = 0.0002) higher rate of isolation than than cervical and urethral swabs. Primary isolations may not display standard textbook morphology. Isolated colonies may be present, but brown streaks in cervical mucus or a coalescent haze around epithelial cells in urine sediment may also be seen in areas of concentrated growth. The broth and agar media used, method of incubation, type of specimen, and method of storing specimens before culture are all factors which influence the recovery of U. urealyticum.