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Lactobacilli are normal inhabitants of our microbiota and are known to protect against pathogens. Neisseria gonorrhoeae is a human specific pathogenic bacterium that colonises the urogenital tract where it causes gonorrhoea. In this study we analysed early interactions between lactobacilli and gonococci and investigated how they compete for adherence to human epithelial cervical cells. We show that lactobacilli adhere at various levels and that the number of adherent bacteria does not correlate to the level of protection against gonococcal infection. Protection against gonococcal adhesion varied between Lactobacillus species. Lactobacillus crispatus, Lactobacillus gasseri and Lactobacillus reuteri were capable of reducing gonococcal adherence while Lactobacillus rhamnosus was not. Lactobacillus strains of vaginal origin had the best capacity to remain attached to the host cell during gonococcal adherence. Further, we show that gonococci and lactobacilli interact with each other with resultant lactobacilli incorporation into the gonococcal microcolony. Hence, gonococci bind to colonised lactobacilli and this complex frequently detaches from the epithelial cell surface, resulting in reduced bacterial colonisation. Also, purified gonococcal pili are capable of removing adherent lactobacilli from the cell surface. Taken together, we reveal novel data regarding gonococcal and lactobacilli competition for adherence that will benefit future gonococcal prevention and treatments.

Pre-processing of spectroscopic data is commonly applied to remove unwanted systematic variation. Possible loss of information and ambiguity regarding discarded variation are issues that complicate pre-treatment of data. In this paper, OPLS methodology is applied to evaluate different techniques for pre-processing of spectroscopic data gathered from a batch process. The objective is to present a rational scheme for analysis of pre-processing in order to understand the influence and effect of pre-treatment. O2PLS uses linear regression to divide the systematic variation in X and Y into three parts; one part with joint X – Y covariation, i.e. related to both X and Y , one part of X with Y -orthogonal variation and one part of Y with X -orthogonal variation. All of the investigated pre-treatment methods removed an additive baseline as expected. In the analysis of raw and differentiated data variation associated with the baseline was found in the Y -orthogonal part of X . Orthogonal information was also found in Y , which suggests that this pre-processing procedure not only removed variation. This would have been more difficult to detect without the O2PLS model since both raw and differentiated data must be analysed simultaneously. Development of a knowledge based strategy with OPLS methodology is an important step towards eliminating trial and error approaches to pre-processing.

Large amounts of food and feed are lost every year due to spoilage by moulds and yeasts. Biopreservation, i.e. the use of microorganisms as preservatives instead of chemicals, has gained increased interest. Lactic acid bacteria and propionibacteria might be particularly useful due to their important role in many food fermentations. Knowledge of the antifungal effects of the organic acids produced by these bacteria is necessary to understand their inhibitory activity. We evaluated the antifungal activity of the type strains of five dairy propionibacteria, Propionibacterium acidipropionici, P. jensenii, P. thoenii, P. freudenreichii subsp. freudenreichii and P. freudenreichii subsp. shermanii against eight food- and feedborne moulds and yeasts. A dual culture system assayed the inhibitory activity on three different agar media, sodium lactate (SL), de Man Rogosa Sharp (MRS) and MRS without acetate (MRS-ac). The amounts of organic acids produced during growth of propionibacteria in liquid SL, MRS and MRS-ac were also determined. The minimal inhibitory concentration (MIC) values of propionic, acetic and lactic acid were established for all fungi at pH 3, 5 and 7. Propionic acid, followed by acetic acid, was the most potent antifungal acid. Inhibition at pH 7 generally required concentrations above 500 mM for all three acids, at pH 5 the MIC values for propionic and acetic acids were 20-120 mM and above 500 mM for lactic acid. At pH 3, the MIC values were, with one exception, below 10 mM for both propionic and acetic acid and above 160 mM for lactic acid. The yeast Pichia anomala was the fungus most resistant to organic acids. The propionibacteria exhibited a pronounced species variation in antifungal activity on MRS (+/-acetate) agar, with P. thoenii being the most potent. Four of the five propionibacteria species produced more propionic and acetic acid in liquid SL medium than in MRS (+/-acetate) broth. However, when SL agar was used as the growth medium, none of the propionibacteria inhibited fungal growth.

Exercise tests and cardiac catheterization were performed in 53 patients, 13 to 26 years after intracardiac repair of tetralogy of Fallot. At the time of repair, the median age was 7 years, and 60% of patients with cyanosis had had a previous palliative procedure. The right ventriculotomy was closed without a patch in 21 patients (40%), a patch restricted to the right ventricle was inserted in 18 patients (34%), and in 14 (26%) the patch extended across the pulmonary anulus. At follow-up, 94% of the patients were free of symptoms. Symptom-limited work capacity was 87% of the predicted value (95% confidence limits, 82% to 94%). Work capacity was inversely related to age at follow-up, to right ventricular systolic pressure at rest, and to presence of moderate or severe pulmonary valve regurgitation. Cardiac output in relation to oxygen uptake was reduced in 74% of patients during exercise. In 12 patients (23%), systolic pressure at rest in the right ventricle was 50 mm Hg or higher. Systolic pressure during exercise in the right ventricle was lower in patients without a patch than in those with a patch and was abnormally high in all groups compared with healthy subjects. The ratio of right to left ventricular pressure was significantly lower than measurements taken immediately after repair. An intracardiac left-to-right shunt was present in 6 patients (11%). Three patients required invasive treatment as a result of our follow-up. We conclude that work capacity was moderately reduced 13 to 26 years after repair of tetralogy of Fallot and was adversely influenced by right ventricular hypertension and pulmonary valve regurgitation. Intermittent lifelong surveillance is advocated, because patients without symptoms may have hemodynamic abnormalities that necessitate intervention. (J THORAC CARDIOVASC SURG 1995;110:416-26)

The gene encoding a plasma protein receptor from Streptococcus dysgalactiae has been cloned and sequenced. The gene product, with a predicted molecular mass of approx. 44 kDa, binds alpha 2-macroglobulin (alpha 2 M), serum albumin and immunoglobulin G (IgG). By subcloning and expressing various parts of the gene as fusion proteins, we found that the three binding activities reside in discrete domains of the protein. The single IgG-binding domain, localized in the C-terminal part of the molecule, shows high homology to streptococcal type-III Fc receptors. In the middle of the molecule, there is a stretch of 50 amino acids (aa) mediating albumin binding. This region has partial homology with the albumin-binding domains of streptococcal protein G. The alpha 2 M-binding domain is located in the N terminus of the molecule and is composed of a unique aa sequence. We call this trifunctional plasma protein receptor, MAG (binds alpha 2 M, albumin and IgG).