Biofilm formation by Propionibacterium acnes is a characteristic of invasive isolates

Propionibacterium acnes is a common and probably underestimated cause of delayed joint prosthesis infection. Bacterial biofilm formation is central in the pathogenesis of infections related to foreign material, and P. acnes has been shown to form biofilm both in vitro and in vivo. Here, biofilm formation by 93 P. acnes isolates, either from invasive infections (n = 45) or from the skin of healthy people (n = 48), was analysed. The majority of isolates from deep infections produced biofilm in a microtitre model of biofilm formation, whereas the skin isolates were poor biofilm producers (p <0.001 for a difference). This indicates a role for biofilm formation in P. acnes virulence. The type distribution, as determined by sequencing of recA, was similar among isolates isolated from skin and from deep infections, demonstrating that P. acnes isolates with different genetic backgrounds have pathogenic potential. The biofilm formed on plastic and on bone cement was analysed by scanning electron microscopy (EM) and by transmission EM. The biofilm was seen as a 10-mum-thick layer covering the bacteria and was composed of filamentous as well as more amorphous structures. Interestingly, the presence of human plasma in solution or at the plastic surface inhibits biofilm formation, which could explain why P. acnes primarily infect plasma-poor environments of, for example, joint prostheses and cerebrospinal shunts. This work underlines the importance of biofilm formation in P. acnes pathogenesis, and shows that biofilm formation should be considered in the diagnosis and treatment of invasive P. acnes infections.

Bacterial vaginosis - a microbiological and immunological enigma. Review article

The development of bacterial vaginosis (BV) among women of childbearing age and the resulting quantitative and qualitative shift from normally occurring lactobacilli in the vagina to a mixture of mainly anaerobic bacteria is a microbiological and immunological enigma that so far has precluded the formulation of a unifying generally accepted theory on the aetiology and clinical course of BV. This critical review highlights some of the more important aspects of BV research that could help in formulating new basic ideas respecting the biology of BV, not least the importance of the interleukin mediators of local inflammatory responses and the bacterial shift from the normally occurring lactobacilli species: L. crispatus, L. gasseri, L. jensenii, and L. iners to a mixed flora dominated by anaerobic bacteria.

Fusidic acid disk diffusion testing of clostridium difficile can be calibrated using single-strain regression analysis

Single-strain regression analysis (SRA) was employed to calibrate the disk diffusion antibiotic susceptibility test for fusidic acid and Clostridium difficile. MIC determinations of 40 clinical isolates of C. difficile were performed with the E-test. The disk diffusion test was standardized according to the Swedish Reference Group for Antibiotics (SRGA). Disks used for SRA contained 1.5, 5, 15, 50 and 150 microg fusidic acid and the routine disk contained 50 microg fusidic acid. A control strain, ATCC 9689, was also tested. SRA constants A and B of the regression lines were calculated. This permitted the determination of zone breakpoints for C. difficile. When applying the pharmacological MIC S and R limits set by SRGA to the E-test results I strain of C. difficile was interpreted as resistant. Zone breakpoints corresponding to the pharmacological MIC limits and calculated using the mean SRA constants for the 40 clinical isolates lead to all strains being interpreted as susceptible. SRA calculations enable laboratories to set up calibrated disk tests with species-related and laboratory-specific interpretations.

Intrauterine infection may be a major cause of stillbirth in Sweden

AIM OF THE STUDY

To investigate intrauterine infection as a cause for unexplained stillbirth.

METHODS

Chorioamnionitis was studied in a material of stillbirths (117 subjects from the years 1985-1994) from a region in the south Sweden. Control material (126 alive and healthy newborns and with healthy mothers) was gathered from the same region.

RESULTS

Chorioamnionitis was a common diagnosis both with stillbirths and 'healthy' deliveries (82 and 68%, respectively). Extension of the inflammation to decidua basalis was seven times more common among stillbirths than among controls (odds ratio 7.2, confidence interval 2.8-21.9). The most common bacteria found at cultures were Escherichia coli, Coagulase negative staphylococcus, Enterococcus faecalis and group B Streptococcus. The risk for stillbirth was doubled if both inflammation and bacteria were present (odds ratio 2.3, confidence interval 0.92-5.8). Meconium discharge was more common among stillbirths than controls (odds ratio=4.7, confidence interval 1.7-14). There were no differences in any respect regarding macerated and non-macerated stillbirths. Our findings are similar to the results from studies in developing countries except for the higher incidence of stillbirths in such countries.

CONCLUSIONS

Thus, a large part of otherwise unexplained stillbirths might be due to ascending infections.

Factors influencing vaginal fetal fibronectin concentrations during pregnancy

In order to evaluate factors influencing fetal fibronectin concentrations during pregnancy a total of 312 vaginal samples for fetal fibronectin measurements and microbiological culture were collected and later included in a stepwise regression analysis. Preterm premature rupture of membranes, a modified Bishop score >/=6 (p < 0.0001), a low vaginal polymorphonuclear leukocyte count (p < 0. 002), the presence of Enterococcus faecalis (p < 0.0001), Prevotella species (p < 0.05), a bacterial vaginosis-associated flora (p < 0. 05), and a non-lactobacilli-dominated vaginal flora (p < 0.05) were associated with an elevated vaginal fetal fibronectin concentration.

Study of knowledge, attitude and practice concerning aspects of torture

The report presents the first attempt of the IMA-AKN Sinha Institute of continuing medical and health education and research to study the knowledge, attitude and practice of doctors regarding torture. Although, majority of the doctors in India are aware of various national and international human rights institutions, but they seem not to be aware of the human rights of the detainees. It is interesting to note that the doctors are aware of the long term physical and psychological effects of torture and also agreed that physical examination is not sufficient to detect torture sequelae. A large number of doctors have seen cases of torture, and were willing to treat them and felt reasonably competent. A significant number of doctors justified use of coercive technique and manhandling in dealing with detainees by law enforcement agencies. A small number of doctors expressed their unwillingness to get involved in the treatment of the victims of torture due to medicolegal consequence. The dissemination of information on human rights and medical ethics and incorporating them into the medical curriculum at undergraduate and postgraduate training was emphasised by majority of the respondents. Almost unanimous view was expressed by respondents on the importance of the role of medical ethics and the profession's responsibility to its members. An important finding of the study is the need for IMA to help establishing counselling and rehabilitation centres for treatment of torture victims and educate its members. A large number of doctors mentioned the need of initiating community action in case of rape, child abuse, dowry victims and sexual harassment. Further, a majority of respondents expressed the view that the medical association should take the responsibilities of protecting the doctors who fearlessly testify cases of torture besides disciplining doctors who facilitate torture. Respondents felt that the reasons for doctors' participation in torture need further study. It is encouraging that most of the responding physicians are willing to take up training and become counsellor for victims of torture to be able to provide treatment, counselling and rehabilitation.

Comparison of muscle sizes and moment arms of two rotator cuff muscles measured by ultrasonography and magnetic resonance imaging

OBJECTIVE

The purpose was to investigate ultrasound (US) and anthropometry (AN) as valid alternatives to magnetic resonance imaging (MRI) regarding muscle size characteristics of two rotator cuff muscles.

METHODS

Eight healthy females (age 27-54 yrs.) went through MRI and US scannings and AN measurements, where muscle thickness, cross-section area (CSA), moment arm, muscle length and width were measured on supraspinatus and infraspinatus muscle.

RESULTS

The agreement between the methods was very satisfactory for CSA, and satisfactory for muscle thickness, moment arm, muscle length and width, with a mean difference below 2 mm in thickness and below 5 mm in muscle length and width. Volume could be estimated satisfactory in supraspinatus muscle, but not in infraspinatus muscle, where volume had to be calculated from thickness, length and width. As a significant relation was found in the MRI measurements between thickness and CSA, thickness measurements may replace CSA in inaccessible muscles.

CONCLUSIONS

US was a valid method in measuring CSA, muscle thickness and moment arm. Combined with anthropometric measures of muscle length and width, volume can be calculated, which is important when defining the physiological cross-sectional area and muscle function. Further development and validation of the method is needed, however.

Calibration of the disk diffusion test for trovafloxacin susceptibility testing of four anaerobic species

OBJECTIVES

To study trovafloxacin susceptibility among clinical isolates of four anaerobic bacterial species using minimum inhibitory concentrations (MIC) determinations, E test assays and disk diffusion test results and to calibrate the disk diffusion method for these species using single strain regression analysis (SRA).

METHODS

One-hundred and eighty-seven clinical isolates of four anaerobic bacterial species were included. Trovafloxacin MIC determinations were performed using the agar dilution technique and MIC estimations using the E test. The disk diffusion test was performed according to Swedish Reference Group for Antibiotics standardization. NCCLS limits for susceptibility categories were applied. SRA was performed using 1, 3, 10, 30, and 100 microg trovafloxacin disk contents and ATCC control strains. The regression lines obtained permitted the calculation of zone equivalents to MIC limits as well as an evaluation of various disk potencies.

RESULTS

Trovafloxacin susceptibility (S + I) was noted in 98.9, 100, 100, and 97% of Bacteroides fragilis, Bacteroides thetaiotaomicron, Clostridium perfringens, and Peptostreptococcus magnus strains, respectively, as judged by MIC determinations. Agar dilution and E test estimations gave the same results, but E test values were consistently lower than MIC values by the reference method. Regression lines calculated for the four species using SRA showed different equation constants indicating species-related differences. Interpretive zone diameter breakpoints were calculated for the four species and used for the interpretation of susceptibility.

CONCLUSIONS

The disk diffusion test was successfully calibrated for trovafloxacin susceptibility testing of four anaerobic species using single strain regression analysis, SRA. There was a good agreement between the results of MIC-tests and disk testing. Interpretive errors of type I are prone to occur among Bacteroides isolates and might require species-related MIC limits. SRA calculations permitted the testing of the effect of different disk potencies on inhibition zones produced at the interpretive MIC limits. Criteria for the selection of a minimal disk content showed that 5 microg trovafloxacin is sufficient, but a 10 microg disk will safeguard against residual laboratory variation without producing too large inhibition zones for very susceptible strains.

Dexamethasone differentially regulates cytokine transcription and translation in macrophages responding to bacteria or okadaic acid

Many microorganisms and microbial products induce expression of pro-inflammatory cytokines such as interleukin-1 (IL-1alpha/beta) and tumour necrosis factor-alpha (TNF-alpha) in macrophages, primarily by transcriptional activation. We show here, by using mouse macrophages in primary culture, that pre-treatment with dexamethasone inhibits bacteria-induced IL-1beta expression as mRNA and cellular pro-IL-1beta in parallel, consistent with an effect primarily on transcriptional activation. In contrast, the expression of TNF-alpha mRNA was only partly inhibited despite virtually complete inhibition of TNF-alpha protein formation. Furthermore, the selective induction of primarily cell-associated 26,000 M, pro-TNF-alpha by the protein phosphatase inhibitor okadaic acid also was partly inhibited at the mRNA level by dexamethasone, whereas additional translational inhibition appeared to be lacking. This latter finding is reminiscent of earlier findings regarding signalling to activation of cytosolic phospholipase A2, which is sensitive to dexamethasone when elicited by bacteria, but not when elicited by okadaic acid. The present results raise the possibility that the inhibitory effect of dexamethasone on TNF-alpha translation, but not on transcriptional activation, is mediated by one or more okadaic acid-sensitive protein phosphatases.

Tonsillar microbial flora: comparison of recurrent tonsillitis and normal tonsils

Tonsillar microbial flora was studied in cultures of tonsillar core specimens from 34 patients tonsillectomized due to recurrent group A streptococcal pharyngotonsillitis (n = 17) or sleep apnoea (n = 17). Patients in the sleep apnoea subgroup, who had no history of recurrent tonsillitis and manifested no tonsillar hypertrophy at ENT examination, served as controls. Tonsillar core specimens were cultured for semi-quantitative estimation of growth of aerobic, anaerobic and facultative organisms. The recurrent tonsillitis and apnoea subgroups did not differ significantly in the mean number of isolates per patient, either of aerobic spp. (3.8 vs. 4.3) or anaerobic spp. (5.2 vs. 4.7). Nor did the two subgroups differ significantly in the proportion of patients whose specimens manifested beta-lactamase producers (71% vs. 59%), in the isolation frequency of viridans (alpha) streptococci, or in the occurrence of semi-quantitative growth estimates of 3-4+ for aerobic, anaerobic or beta-lactamase-producing spp. Thus, the study provided no support for the hypothesis that inactivation of penicillin V by beta-lactamase-producing bacteria in oral or throat flora, or the eradication of viridans streptococci with their GAS-inhibitory capacity, is an important factor with regard to recurrent group A streptococcal tonsillitis. Other possible explanations, such as poor antibiotic penetration at the site of infection, are discussed.

Multiple C-terminal serine phosphorylation accompanies both protein kinase C-dependent and -independent activation of cytosolic 85 kDa phospholipase A2 in macrophages

Exposure of mouse macrophages to either phorbol ester or certain bacteria was previously shown to cause increased phosphorylation of the cytosolic 85 kDa phospholipase A2 as well as a stable increase in its catalytic activity. We have now attempted to map the major phosphorylation sites on the enzyme in such cells. Phosphorylation occurred on serine residues without a detectable increase in either phosphothreonine or phosphotyrosine. After CNBr cleavage five fragments showed increased 32P labelling. Among those the most heavily labelled fragment was identified as the most C-terminal (residues 698-749), containing six serine residues. This was true whether phorbol ester or bacteria, causing protein kinase C-independent phospholipase A2 activation, was used as stimulus. The heavy phosphorylation of the most C-terminal fragment and an analysis of tryptic peptides derived from it suggested that more than one of the six serine residues became phosphorylated. Smaller increases also occurred in other CNBr-cleaved fragments from the C-terminal part of the protein, including that carrying Ser-505, a known target of the mitogen-activated protein kinase ERK-2 (extracellular-signal regulated kinase). Dexamethasone treatment (1-100 nM for 20 h), which was earlier shown to dose-dependently down-regulate the 85 kDa phospholipase A2 and its activation by phorbol ester and zymosan, was here shown also to counteract the protein kinase C-independent activation and arachidonate release elicited by bacteria. It remains to be determined whether all phosphorylation sites are equally affected under those conditions.

Fetal fibronectin and microorganisms in vaginal fluid of women with complicated pregnancies

OBJECTIVES

To determine vaginal fetal fibronectin in women with pregnancies complicated by preterm labor (PTL), preterm premature rupture of the membranes (PPROM) or bleeding; to investigate possible relationships to the vaginal microflora; and to assess the ability to predict preterm delivery from these measures.

MATERIAL AND METHODS

Group comparative study between women of the same gestational age with a normal pregnancy (n = 28) and consecutive women admitted with PTL (n = 63), PPROM (n = 18) and bleeding (n = 21). Samples of vaginal fluid were collected at the time of admission in complicated pregnancies and from the women with normal pregnancies. Fetal fibronectin was determined by enzyme immunoassay and quantitative aerobic and anaerobic microbiological cultures were performed.

RESULTS

The number of positive (> or = 0.05 mg/L) vaginal fetal fibronectin values was higher among women with PTL, PPROM and bleeding compared to controls (p < 0.001). A positive fibronectin value was predictive of delivery < or = 34 weeks (sensitivity 64%, specificity 87%). The absence of hydrogen peroxide-producing lactobacilli was predictive for preterm delivery < 34 weeks (sensitivity of 100%, specificity 35%).

CONCLUSIONS

The presence of vaginal fibronectin and the absence of hydrogen peroxide-producing lactobacilli was indicative of an increased risk for preterm delivery < 34 weeks.

Microorganisms in vaginal fluid from women in prolonged pregnancy

In order to compare the vaginal microflora of women in prolonged pregnancy with that of women who delivered at term, samples for quantitative aerobic and anaerobic microbiological culture were collected from 100 women at 42 weeks of gestation and from 60 women at term. The occurrence of lactobacilli-dominated flora was similar in women at term and women with prolonged pregnancy. However, non-hydrogen-peroxide-producing lactobacilli (p < 0.01) were significantly more common and Peptostreptococci species (p < 0.05) significantly less common in postterm women as compared with term controls. In postterm women, Candida albicans was more common (p < 0.001) in microfloras dominated by non-hydrogen-peroxide-producing lactobacilli than in floras dominated by hydrogen-peroxide-producing lactobacilli. The ecosystem of the vagina in asymptomatic postterm women was disrupted concerning the composition of lactobacilli as compared with term controls.

Protein PAB, an albumin-binding bacterial surface protein promoting growth and virulence

The anaerobic bacterium Peptostreptococcus magnus is a human commensal and pathogen. Previous work has shown that strains of P. magnus isolated from patients with gynecological disease (vaginosis) frequently express an immunoglobulin (Ig) light chain-binding protein called protein L. Here we report that strains isolated from localized suppurative infections bind human serum albumin (HSA), whereas commensal isolates bind neither Ig nor HSA. The HSA-binding protein PAB was extracted from the bacterial surface or isolated from the culture supernatant of the P. magnus strain ALB8. Protein PAB was shown to have two homologous HSA-binding domains, GA and uGA. GA is absent in the sequence of a related protein from another P. magnus strain and shows a high degree of homology to the HSA-binding domains of streptococcal protein G. Therefore GA is believed to have recently been shuffled as a module from genes of other bacterial species into the protein PAB gene. This GA module was shown to exhibit a much higher affinity for HSA than uGA and was also found to be present in all of the isolates tested from localized suppurative infections, indicating a role in virulence. Moreover, when peptostreptococci or streptococci expressing the GA module were grown in the presence of HSA, the growth rate was substantially increased. Thus, the HSA binding activity of the GA module adds selective advantages to the bacteria, which increases their virulence in the case of P. magnus strains.

The bacterial flora of the genitourinary tract in healthy fertile men

The clinical significance of microorganisms in semen is unclear, as they may signify contamination rather than infection. Specimens from six locations in 97 healthy men scheduled for vasectomy were analyzed. Totally 1033 strains, aerobic or anaerobic, were isolated. Of 61 intraoperatively obtained vas deferens cultures, only one was positive. Of the 97 semen samples, 83% contained bacteria, 140 aerobes and 113 anaerobes; 44% of the strains found in semen and 58% of those in prostatic secretion were also identified in the urethra. The finding that 71% of the strains colonizing the coronal sulcus were present in the urethra indicates that the distal part of the urethra is colonized by a bacterial flora similar to that in the sulcus. The urethral flora may then contaminate semen and prostatic secretion. Presence of multiple bacterial species in semen was not associated with abnormal sperm function.

Fetal fibronectin and microorganisms in vaginal fluid of healthy pregnant women

OBJECTIVE

To determine fetal fibronectin in vaginal fluid from healthy women during uncomplicated pregnancy and to investigate possible relationships to gestational age and the vaginal microflora.

MATERIALS AND METHODS

Samples of vaginal fluid were collected for fetal fibronectin determination and for quantitative aerobic and anaerobic microbiological culture from 22 women followed longitudinally at 12, 28 and 37 weeks gestation cross-sectionally in women at 12 weeks (n = 10), 28 weeks (n = 10), 37 weeks (n = 10), and 39 weeks (n = 30) gestation, respectively. Fetal fibronectin was determined by a quantitative enzyme immunoassay (Adeza Biomedical).

RESULTS

There were no significant differences between the concentrations of fetal fibronectin in vaginal secretions at any of the four measurement points (12, 28, 37 and 39 weeks gestation). Women with elevated fetal fibronectin concentration (> or = 0.05 mg/L) had less often hydrogen peroxide-producing facultative lactobacilli (p < 0.0001), and more often bacterial vaginosis (p < 0.02) and Peptostreptococcus species (p < 0.002). Bacterial vaginosis (p < 0.01) and Candida albicans (p < 0.01) were more frequently found in women lacking hydrogen peroxide-producing lactobacilli.

CONCLUSION

Fetal fibronectin in vaginal fluid was more associated with the vaginal microflora than with the gestational age of the pregnancy. Presence of hydrogen peroxide-producing lactobacilli seems to be the most important factor for a stable vaginal microflora.

Protein shift and antigenic variation in the S-layer of Campylobacter fetus subsp. venerealis during bovine infection accompanied by genomic rearrangement of sapA homologs

Campylobacter fetus subsp. venerealis isolated from a case of human vaginosis was inoculated into the uterus of a C. fetus-negative heifer. Isolates obtained weekly from the vaginal mucus exhibited variations in high-molecular-mass-protein profiles from that of the original inoculum, which had a dominant 110-kDa S-layer protein. Immunoblots of the weekly isolates with monoclonal antibody probes against the 110-kDa S-layer protein and other C. fetus S-layer proteins demonstrated antigenic shifts. Genomic digests of the isolates probed with a 75-mer oligonucleotide of the conserved sapA region also indicated that antigenic variation of the S-layer is accompanied by DNA rearrangement.

Cyclosporin-sensitive expression of cytokine mRNA in mouse macrophages responding to bacteria

Characteristics of the cytokine response in resident mouse macrophages to certain Gram-positive and Gram-negative bacteria have been investigated by monitoring the expression of mRNA encoding interleukin-1 alpha and -beta (IL-1 alpha/beta) and tumor necrosis factor-alpha (TNF-alpha). Expression of these cytokine mRNAs occurred within 30-60 min. Both the flavonoid quercetin and phloretin inhibited the expression of IL-1 alpha/beta as well as TNF-alpha mRNA, with quercetin being more potent than phloretin and TNF-alpha expression somewhat more sensitive than that of IL-1 alpha/beta. Expression of all three cytokine mRNAs was also inhibited by prostaglandin E2, with an IC50 of > 1 microM, but not by the phosphodiesterase inhibitor pentoxifylline, although lipopolysaccharide-induced expression of TNF-alpha mRNA was inhibited. Down-regulation of phorbol ester-sensitive isoforms of protein kinase C had virtually no effect on the cytokine response to bacteria, and treatment of resting macrophages with phorbol ester did not cause expression of any of the cytokine mRNAs investigated. Among protein phosphatase inhibitors, cyclosporin A caused extensive inhibition of bacteria-induced expression of both IL-1 alpha/beta and TNF-alpha mRNA, while okadaic acid in itself caused selective induction of TNF-alpha, but not IL-1 alpha/beta mRNA, with a sharp peak at 0.3 microM concentration. At higher concentrations of okadaic acid, at which protein/phosphatase 2B/calcineurin would also be inhibited, the induction was completely reversed. This suggests that critical phosphorylation events, counteracted by one or more okadaic acid-sensitive protein phosphatase(s), and a dephosphorylation event carried out by a cyclosporin-sensitive protein phosphatase are both necessary for transcriptional activation of the TNF-alpha gene.

Dynamic accumulation of neutrophils in lungs and visceral organs during early abdominal sepsis in the pig

Activation and accumulation of polymorphonuclear leukocytes (PMNs, neutrophils) in the lungs is considered an important mechanism in the pathogenesis of pulmonary dysfunction in association with sepsis. It probably constitutes only part of a general cellular response; and a corresponding reaction has been implicated in other organs during sepsis (e.g., the liver). In this experiment a model was developed that allows study of the dynamic PMN reaction in the lungs and visceral organs during early abdominal sepsis. The animals were divided into two groups. In the septic group (n = 8) a bacterial challenge was attempted through the intraperitoneal administration of Escherichia coli (1 x 10(11)/kg). Five animals served as controls. All animals in the septic group developed bacteremia, leukopenia, and a hypodynamic circulatory response. PMNs were selectively labeled with 111In-oxine. The activity over the organs was followed dynamically with a gamma camera. The animals subjected to peritonitis exhibited a significant increase in 111In-oxine activity (i.e., neutrophil trapping) in the lungs, compared to the controls at 40 minutes and onward during the observation period. A similar picture was seen over the liver and abdomen, with significance after 70 minutes. The findings in this study indicate that accumulation of PMNs is an early phenomenon not only in the lungs but also in the liver during the development of sepsis. The present model offers possibilities for further studies of the cellular reactions during sepsis.

Vaginal discharge--comparison of clinical, laboratory and microbiological findings

Of 101 fertile women (15-50 years of age) consulting in general practice due to vaginal discharge and/or genital malodor, bacterial vaginosis was diagnosed in 34% and vaginal candidiasis in 23%. The presence of Chlamydia trachomatis, Trichomonas vaginalis, genital herpes virus and Neisseria gonorrhoeae was demonstrated in 15%, 9%, 7%, and 1% of cases, respectively. No specific genital tract pathogens were found in 25 patients, where the clinical diagnosis was psychological factors (n = 5), intra-uterine device-associated discharge (n = 5), cytolytic vaginosis (n = 5), urinary tract infection (n = 3), or other/unknown causes (n = 7). In most cases diagnosis of bacterial vaginosis, vaginal candidiasis or trichomoniasis was established by clinical examination and simple office tests (pH indicator paper, amine test, microscopy of wet smear, yeast culture kit). C. trachomatis and N. gonorrhoeae were diagnosed by means of culture, cervicitis being diagnosed clinically in five of 15 cases with culture-confirmed chlamydial infection, while gonorrhoea was suspected from findings in a stained cervical smear. Sexually transmitted micro-organisms were detected in 16% of women with bacterial vaginosis or candidiasis. Of 29 women with sexually transmitted agents, 14% harbored more than one such organism.

Measurement issues in research on social support and health

STUDY OBJECTIVE

The aims were: (1) to identify methodological problems that may explain the inconsistencies and contradictions in the research evidence on social support and health, and (2) to validate a frequently used measure of social support in order to determine whether or not it could be used in multivariate analyses of population data in research on social support and health.

DESIGN AND METHODS

Secondary analysis of data collected in a cross sectional survey of a multistage cluster sample of the population of the United States, designed to study relationships in behavioural, social support and health variables. Statistical models based on item response theory and graph theory were used to validate the measure of social support to be used in subsequent analyses.

PARTICIPANTS

Data on 1755 men and women aged 20 to 64 years were available for the scale validation.

RESULTS

Massive evidence of item bias was found for all items of a group membership subscale. The most serious problems were found in relationship to an item measuring membership in work related groups. Using that item in the social network scale in multivariate analyses would distort findings on the statistical effects of education, employment status, and household income. Evidence of item bias was also found for a sociability subscale. When marital status was included to create what is called an intimate contacts subscale, the confounding grew worse.

CONCLUSIONS

The composite measure of social network is not valid and would seriously distort the findings of analyses attempting to study relationships between the index and other variables. The findings show that valid measurement is a methodological issue that must be addressed in scientific research on population health.

Bacterial vaginosis and vaginal microorganisms in idiopathic premature labor and association with pregnancy outcome

The vaginal microflora of 49 women in idiopathic preterm labor was compared with that of 38 term controls to determine whether the presence of bacterial vaginosis (BV) and/or specific microorganisms would influence the rate of preterm delivery. Demographic factors, pregnancy outcome, and reproductive history were also studied. BV, as defined by the presence of clue cells in a vaginal wet mount and characteristic microbial findings in a stained vaginal smear and vaginal culture, was more common in women with preterm labor and delivery than in controls (P < 0.01). The condition, diagnosed in 41% of women who had both preterm labor and delivery (n = 22) and in 11% each of women who had preterm labor but term delivery (n = 27) and controls, was associated with a 2.1-fold risk (95% confidence intervals, 1.2 to 3.7) for preterm birth prior to 37 weeks of gestation. BV was associated with low birth weight. Of 49 women with preterm labor, 67% (8 of 12) of women with BV were delivered of low-birth-weight neonates (< 2,500 g) compared with 22% (8 of 37) of women without the condition (P < 0.0005). The presence of hydrogen peroxide-producing facultative Lactobacillus spp. was strongly negatively associated with both preterm delivery and BV. BV-associated microorganisms, i.e., Mobiluncus, Prevotella, and Peptostreptococcus species, Porphyromonas asaccharolytica, Fusobacterium nucleatum, Mycoplasma hominis, and high numbers of Gardnerella vaginalis were significantly associated with preterm delivery; all species also strongly associated with BV (P = 0.0001 for each comparison). Mobiluncus curtisii and Fusobacterium nucleatum were recovered exclusively from women with preterm delivery. Our study clearly indicates that BV and its associated organisms are correlated with idiopathic premature delivery.

Endotoxin and microorganisms in percolate derived from compostable household waste

Health related problems among Danish garbage collectors have been reported. Separated compostable household waste was analyzed for endotoxin and microorganisms in an experimental study. Aerosols and liquid (percolate) from the waste were sampled over two 14-day periods during storage in containers.

Erythromycin versus metronidazole in the treatment of bacterial vaginosis

Of 101 women, 15-50 years of age, presenting with vaginal discharge, 34 had bacterial vaginosis and were randomly assigned to a seven-day course of oral treatment with either erythromycin (0.5 g b.i.d.) or metronidazole (0.4 g b.i.d.) in a single-blind, cross-over study. Treatment failure (> or = three clinical signs of bacterial vaginosis) occurred in 13 (81%) of 16 patients given erythromycin, as compared with three (17%) of 18 women treated with metronidazole (p < 0.001). Persistence of Gardnerella vaginalis, Mobiluncus species and/or Mycoplasma hominis was found in 14 of 16 patients treated with erythromycin, and in four of 16 patients treated with metronidazole. Treatment with metronidazole was successful (< or = two clinical signs of bacterial vaginosis) in eight of 10 cases of erythromycin treatment failure. Neither of two cases of metronidazole treatment failure was cured with erythromycin. At three-month follow-up of 31 women, persistence or recurrence of bacterial vaginosis was diagnosed in 11 cases (36%).

Determination of chromium in blood and serum: evaluation of quality control procedures and estimation of reference values in Danish subjects

This paper describes analytical methods to estimate environmental and occupational exposure levels of chromium in blood and serum by Zeeman atomic absorption spectrometry. Also reported is an internal quality control procedure involving a combination of an online quality control and subsequent statistical evaluation of the quality control results to evaluate the performance of the analytical methods. The solubilization of the blood by the proteinase Subtilisin A resulted in a recovery of chromium of 106 +/- 4.5%; the uncertainty was approximately 10% at a chromium level of 1 microgram l-1. The detection limit (LOD) for chromium in serum was 0.17 micrograms l-1 and 0.20 micrograms l-1 for chromium in blood. The LODs were sufficiently low for the determination of chromium in a large fraction of reference populations not occupationally exposed. The present study indicates that reference values for chromium in blood and serum are low but within the range in recent investigations, i.e. 0.04-0.35 micrograms l-1 in serum and 0.12-0.34 micrograms l-1 in human whole blood. The fraction of reference values below LOD was between 0.45 and 0.57 for chromium in serum and blood. Consequently, the reference populations were described by distribution free one-sided tolerance intervals and the precision of the estimation of the tolerance intervals was expressed as coverage intervals. The 95% one-sided tolerance limit calculated for chromium in serum was 0.60 micrograms l-1 with the coverage interval (95 +/- 4.8) percent at a probability of 0.95. Thus, the probability was 0.975 that the tolerance interval covers at least 90.2% of the distribution. In addition, the probability was 0.025 that the tolerance interval covers more than 99.8% of the population. It was only possible to calculate the 90% tolerance interval for chromium in blood with the coverage interval at 0.90 probability. The one-sided tolerance interval for chromium in blood was 0.37 micrograms l-1 with the coverage interval (90 +/- 9.9) percent at a probability of 0.90.

Phosphorylation and activation of the arachidonate-mobilizing phospholipase A2 in macrophages in response to bacteria

The role of potential target enzymes in the protein-kinase-C-independent eicosanoid response triggered by certain bacteria in murine peritoneal macrophages [Svensson, U., Holst, E. & Sundler, R. (1991) Eur. J. Biochem. 202, 699-705] has been investigated. The eicosanoid response was found to be due to an increase in the mobilization of arachidonate rather than to inhibition of arachidonate esterification or activation of the cyclooxygenase pathway and to be accompanied by a persistent increase in the activity of the arachidonate-mobilizing phospholipase A2 (PLA2-85). Also, down-regulation of protein-kinase C by prolonged treatment with 4 beta-phorbol 12-myristate 13-acetate did not reduce the bacterial activation of PLA2-85. The increase in activity of PLA2-85, like the increase in eicosanoid formation, showed a lag period of approximately 10 min. Furthermore, exposure of 32P-labeled macrophages to either bacteria (Gardnerella vaginalis) or the protein-phosphatase inhibitor okadaic acid caused an increase in the phosphorylation of PLA2-85. Okadaic acid (0.5 microM), which itself caused arachidonate mobilization and activation of PLA2-85 after a lag period of approximately 45 min, greatly promoted the response to bacteria even at earlier time points. This study provides strong evidence that the eicosanoid response to bacteria in macrophages occurs via a protein-kinase-C-independent activation of PLA2-85 and that this activation is due to an increase in the phosphorylation of the enzyme.

Danish external quality assessment scheme: an interlaboratory comparison study on lead, cadmium and chromium in lyophilized human blood concentrate

A Danish External Quality Assessment Scheme (EQAS) was carried out by the Danish National Institute of Occupational Health during the period 1988-1992. The scheme was implemented for 29 international laboratories from 15 countries assaying lead, cadmium, and chromium in human blood to ascertain the systematic error and uncertainty of the analytical methods. In the survey the quality control material AMI B701-B705, based on lyophilized human whole-blood concentrate, were used. As an estimate of the true values the reference values used in this evaluation were (a) the computed values, i.e., sum of the basal and spiked trace element concentration, and (b) the consensus values normally used in the Danish EQAS. This international evaluation of lead, cadmium, and chromium in human blood demonstrated that the use of lyophilized human blood concentrate quality control materials combined with this scheme is valuable in estimating the systematic error and the uncertainty of the analytical methods. For evaluating analytical performance, the computed values were preferable to the consensus values for lead and cadmium in human blood. Due to analytical difficulties suitable reference values were not established for chromium in blood. The study revealed analytical difficulties for cadmium and chromium in human blood. The assessment of laboratories according to established performance indexes indicates that few laboratories can maintain these performance indexes.

Characterization and distribution of Pasteurella species recovered from infected humans

During a 3-year period, all Pasteurella strains recovered at the Clinical Microbiological Laboratory, Lund, Sweden, were studied biochemically with respect to their relationship to the recently described taxa of this genus. Of 159 strains recovered from 146 infected humans, 95 were identified as Pasteurella multocida subsp. multocida, 21 as Pasteurella multocida subsp. septica, 28 as Pasteurella canis, 10 as Pasteurella stomatis, and 5 as Pasteurella dagmatis. The homology within and between the Pasteurella species regarding cellular fatty acids and enzymatic activities was also studied. Strains of the different Pasteurella species were indistinguishable from each other regarding fatty acid composition; all strains contained major amounts of C14:0, C16:1, C16:0, and 3-OH-C14:0 acids and minor amounts of C18:2, C18:1, and C18:0 acids. Neither did the enzymatic activities distinguish between strains belonging to different species. In addition, of 56 strains examined, toxin production was demonstrated only in 1 strain each of P. multocida subsp. multocida and P. canis. Except for one severe case of necrotizing cellulitis involving P. dagmatis, P. multocida subsp. multocida or P. multocida subsp. septica was recovered in the more serious cases of infection. Except for P. canis, which in all cases was associated with dog bites, most Pasteurella strains were recovered in cases of infection associated with cat bites or scratches. Pasteurella strains occurred in four infected patients without evident connections with animals.

Severe Pasteurella multocida infections in pregnant women

We report 2 cases of severe infections due to Pasteurella multocida, both occurring during pregnancy in previously healthy women. Both women had contact with animals (dog and cat) but neither of them had been bitten. Apart from a slight decrease in IgG levels, no immunological defects could be detected. Both women had received oral phenoxymethylpenicillin in the early phase of the disease, but still fell ill with severe infections. One woman had meningitis while the other suffered from cellulitis with deep abscess formation.

Increased passage of bovine serum albumin over the respiratory tract after intratracheal instillation during septic shock in rats

Sepsis may initiate acute respiratory distress syndrome which may be accompanied by an increased pulmonary epithelial-endothelial permeability. In this study, sepsis was induced by an intraperitoneal implantation of gelatine capsules containing Escherichia coli/Bacteroides fragilis/adjuvant substance. The importance of bacteria in sepsis-related lung injury was studied in rats given an intraperitoneal injection of E. coli or in rats given the adjuvant substance alone in capsules intraperitoneally. Rats with empty capsules were used as controls. The rats were intratracheally instilled with bovine serum albumin (BSA) directly after the capsule implantation or the injection of E. coli, and the passage over the lower respiratory tract was assessed as blood plasma levels of immunoreactive BSA. The plasma BSA levels in the control rats increased continuously up to 24 h after intratracheal instillation. This increase was significantly augmented already 1 h after the septic challenge, i.e. before any clinical symptoms were observed, in both the septic rats and the rats with the E. coli injected intraperitoneally. Furthermore, the time required to obtain maximal plasma BSA levels was shorter in septic, adjuvant-exposed and in E. coli-injected rats than in the controls. The plasma levels and the total BSA passage over the lower respiratory tract was significantly higher (p less than 0.001) in the septic and in the E. coli-injected rats than in the adjuvant-exposed and the control rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Validation of a high-performance liquid chromatography/fluorescence detection method for the simultaneous quantification of fifteen polycyclic aromatic hydrocarbons

A high-performance liquid chromatography/fluorescence method using multiple wavelength shift for simultaneous quantification of different PAH compounds was developed. The new method was superior to the methods of DONG and GREENBERG [J. Liquid Chromatogr. 11, 1887-1905 (1988)] and WISE et al. [Polycyclic aromat. Hydrocarb. (in press)] with respect to sensitivity of detection of the majority of 15 PAH compounds, and in particular of naphthalene, acenaphthene, fluorene and benzo(b)fluoranthene. The method of validation analysis employed showed that the new method is in statistical balance meaning that no systematic errors, and only small unsystematic errors, could be demonstrated. Furthermore, the method had a good reproducibility and a high sensitivity.

Old persons' contact with general practitioners in relation to health: a Danish population study

The study describes health, social situation, and contact with general practitioners in a random sample of non-institutionalized persons 70-95 years old in Denmark. There was a strong correlation between health and contact with general practitioners. A small group, 3% of the respondents, had no health problems, but had been in contact with a general practitioner within the previous month. This group was characterized by a strong social network and a high degree of life satisfaction. Another small group, including 3% of the respondents, had extensive health problems, but had nevertheless not been in contact with a general practitioner within the previous year. This group was characterized by a weak social network and a low degree of life satisfaction.

Protein-kinase-C-independent activation of arachidonate release and prostaglandin E2 formation in macrophages interacting with certain bacteria

Certain bacterial species, of which we selected Fusobacterium nucleatum, Gardnerella vaginalis, Peptostreptococcus anaerobius and Propionibacterium acnes, were found to induce release of arachidonic acid in a dose- and time-dependent manner in mouse macrophages. The release of arachidonic acid showed a characteristic lag period of approximately 10 min and was accompanied by selective transformation into prostaglandin E2. Bacteria killed by various methods caused a similar response, indicating that bacterial surface structures rather than secreted products were involved. Down-regulation of protein kinase C by treatment of macrophages with 4 beta-phorbol 12-myristate 13-acetate hardly affected the response to bacteria at all, except for a partial inhibition in the case of P. acnes. Furthermore, the generation of prostaglandin E2 was synergistically enhanced when macrophages were exposed to both bacteria and phorbol ester. It is also unlikely that bacterial activation was mediated exclusively via a rise in cytosolic [Ca2+], since bacteria stimulated the release of arachidonic acid also when [Ca2+] was clamped at various levels and since the response to bacteria was enhanced in an additive to synergistic manner when combined with calcium ionophore. Changes in protein phosphorylation in macrophages exposed to F. nucleatum (Gram-negative) were virtually identical to those seen with bacterial lipopolysaccharide, while P. anaerobius (Gram-positive) induced enhanced labeling of a single detectable phosphoprotein. In both cases, the changes in protein phosphorylation showed a time lag of 4-8 min and occurred independently of protein kinase C, consistent with a possible role in signal transduction. These results demonstrate that certain bacteria cause activation of arachidonic acid release and prostaglandin E2 formation in mouse macrophages; that the response is independent of protein kinase C and that it is not wholly mediated via a rise in cytosolic [Ca2+].

Prostatectomy in Denmark. Regional variation and the diffusion of medical technology 1977-1985

In many countries prostatectomy is one of the most common surgical operations in elderly men. We used administrative data for the entire male population of Denmark to study temporal and regional variations in the use of prostatectomy from 1977 to 1985. The total annual number of prostatectomies increased by 43% during the period, when the transurethral procedure (TURP) gradually replaced traditional open surgery. TURP accounted for 56% of all operations in 1977 but increased its share to 92% in 1985. Substantial regional variations occurred with index values for prostatectomy in 72 recruitment areas ranging from 0.56 to 1.62 (SCV x 100 = 5.3). The amount of variation decreased during the process of technology diffusion, but remained at a relatively high level (as in other countries) even after the process had been completed (SCV x 100 = 5.1).

Reservoir of four organisms associated with bacterial vaginosis suggests lack of sexual transmission

This study consisted of a search for the possible reservoir and mode of spread of the four bacterial vaginosis-associated organisms Mobiluncus mulieris, Mobiluncus curtisii, Mycoplasma hominis, and Gardnerella vaginalis. Their occurrence in rectal, oral, and pharyngeal specimens from women with and without bacterial vaginosis, their male sexual consorts, four homosexual men, and children (altogether, 374 people) was studied. Genital samples were also obtained from all adults. All four organisms were isolated from the rectums of 45 to 62% of women with bacterial vaginosis and 10 to 14% of women without bacterial vaginosis. They also occurred in the rectums of males and children. M. hominis was recovered from the oropharynxes of 12 adults whose sexual consorts had genital occurrences of the organism. Mobiluncus spp. occurred only in the vaginas of women with bacterial vaginosis (97%). The organisms were only infrequently recovered from genital samples from 135 males. Organisms were recovered from the urethras and/or coronal sulci of 10 of 44 male consorts of women with bacterial vaginosis. However, after 2 weeks of condom use during sexual intercourse, only M. hominis remained in the urethra of one man. These findings suggest that the organisms associated with bacterial vaginosis are not spread sexually but colonize the vagina from an endogenous intestinal tract site. The pathophysiological mechanisms leading to bacterial vaginosis in a subpopulation of all women are still unknown.

Emergence and persistence of beta-lactamase-producing bacteria in the upper respiratory tract in children treated with beta-lactam antibiotics

PURPOSE

To assess the ecologic impact, in terms of selection of beta-lactamase-producing respiratory tract bacteria, of a single course of peroral beta-lactam antibiotics.

PATIENTS AND METHODS

One-hundred fifty consecutive children with clinical signs of bacterial respiratory tract infection were randomly assigned to a seven-day course of treatment with either penicillin V, amoxicillin, or cefaclor. Bacteriologic specimens were collected before treatment, at its termination, and at follow-up four weeks later.

RESULTS

All three drugs investigated caused a similar increase in beta-lactamase-producing bacteria, both in absolute and relative terms, an increase that persisted over a period of at least one month after completion of treatment.

CONCLUSION

Penicillin V, amoxicillin, and cefaclor all act as selective agents for beta-lactamase-producing bacteria in the upper respiratory tract. Treatment with a peroral beta-lactam antibiotic puts patients at risk of becoming persistent carriers of beta-lactamase-producing bacteria.

Treatment of bacterial vaginosis in pregnancy with a lactate gel

10 pregnant women with bacterial vaginosis were treated vaginally with a low-pH lactate gel intermittently during 6 weeks. Reappearance of a lactobacillus-dominated vaginal flora was observed after a few days treatment in all patients. All women experienced a subjective disappearance of abnormal vaginal discharge and malodour. This local treatment restores the normal vaginal acidity and facilitates recolonization with lactobacilli. It may be preferable to oral antimicrobial therapy, especially during pregnancy.

In vitro activities of cefcanel and some other cephalosporins against Pasteurella multocida

Thirty-five strains of Pasteurella multocida from humans and animals were tested for susceptibility to five cephalosporins by a broth dilution method. Cefcanel showed high activity against all isolates (MIC and MBC, less than or equal to 0.64 micrograms/ml). The corresponding figure for cefaclor and cefuroxime was 2.56 micrograms/ml. Cefadroxil and cephalexin were the least active compounds tested.

Cefadroxil as an alternative to metronidazole in the treatment of bacterial vaginosis

A randomized single-blind study was performed to compare the efficacy of cefadroxil to that of metronidazole in the treatment of bacterial vaginosis. 22 women completed the study with follow-ups after 1 and 4 weeks. After completion of treatment 2/11 women receiving metronidazole still had bacterial vaginosis compared with 1/11 women receiving cefadroxil. At follow-up after 4 weeks 3/10 women treated with cefadroxil had recurrent bacterial vaginosis while the corresponding figures for metronidazole were 2/9.

Pasteurella multocida occurs in a high frequency in the saliva of pet dogs

Pasteurella multocida is a frequent cause of infection after animal bites. In contrast to earlier reports, P. multocida appeared to be as common among dogs as among cats. We found 17 (81%) of 21 pet dogs to harbour P. multocida in their saliva. At normal contact, the risk of transmission from dogs to humans seems to be negligible. Only 1/27 dogs owners was found to harbour the organism. None of 13 cat owners or 23 persons without animal contacts harboured P. multocida.

Gas chromatographic comparison of peptone yeast glucose and gas liquid chromatography growth media for anaerobic bacteria

The growth media peptone yeast extract glucose broth and gas liquid chromatography broth were compared with respect to their suitability for anaerobic bacteria, using 63 strains belonging to 12 species. After incubation for 24 and 48 h the broth cultures were subjected to viable counts and gas chromatographic analysis of short-chain alcohols and fatty acids in head-space vapours and ether extracts. Head-space analysis was superior to the ether extraction method for detecting the rapidly eluting short-chain alcohols. The gas liquid chromatography medium provided superior growth and contained fewer compounds that interfered with the chromatographic analyses. Whereas incubation in gas liquid chromatography medium for 24 h gave characteristic chromatograms for all but one of the studied species, most species required 48 h of incubation in peptone yeast extract glucose medium. Gas liquid chromatography broth is the preferred substrate for use in gas chromatographic identification of anaerobic bacteria.

Bacterial vaginosis: microbiological and clinical findings

A prospective study was performed involving 101 women who consecutively attended a primary health care unit for complaints of genital malodour and/or abnormal vaginal discharge. Bacterial vaginosis was diagnosed in 34 women on the basis of four diagnostic criteria: vaginal pH greater than 4.7, homogeneous vaginal discharge, a positive amine test and clue cells. The sensitivity of these criteria was greater than 90% except for homogeneous discharge (82%). Their specificity was greater than 90% except for vaginal pH greater than 4.7 (46%); a specificity of 87% could have been achieved by using the criterion for vaginal pH greater than or equal to 5.0. There was a strong association between diagnosis of bacterial vaginosis and the concomitant occurrence of Gardnerella vaginalis, Mobiluncus spp. and Bacteroides spp. There was no difference between women with or without bacterial vaginosis as regards contraception methods (except for use of an intrauterine device), age at first intercourse, or earlier episodes of vaginal discharge. Sexual transmission of the predominant bacteria was not supported by data collected from the male consorts.