60 patients with 60 viridans streptococcal bacteraemic episodes (42 due to penicillin-sensitive and 18 due to penicillin-resistant viridans streptococci) were analysed in a population of 12,185 ...admissions and 1,380 bacteraemic episodes during a 7-year period in a National Cancer Institute. The incidence of viridans streptococci among bacteraemias decreased from 11.5% in 1989 to 2.5% in 1995 after penicillin was introduced for prophylaxis of febrile neutropenia in acute leukaemia in 1993. However, the proportion of penicillin-resistant viridans streptococcal bacteraemias increased from 0 in 1989 and 1990 before any prophylaxis was given, to 12.9-16.7% after quinolones were used for prophylaxis in 1991 and 1992, and to 44.4-81.8% in 1993-1995 after penicillin was added to the quinolones. Mortality rate was higher in the subgroup of penicillin-resistant viridans streptococcal bacteraemias (p < 0.05). Statistically significant risk factors in patients with penicillin-resistant (compared with penicillin-sensitive) viridans streptococcal bacteraemia were: acute leukaemia (p < 0.03), high doses of cytarabine (p < 0.05), mucocutaneous lesions (p < 0.004), breakthrough bacteraemia during prophylaxis with ofloxacine plus penicillin (p < 0.001). Multiple logistic regression analysis showed that only acute leukaemia (OR 2.05, CI 0.85-1.85, p < 0.0452) and penicillin-resistance (OR 0.71, CI 0.103-4.887, p < 0.0209) were significant independent predictors of inferior outcome. Breakthrough bacteraemia during empiric therapy with vancomycine occurred in 5 of 116 patients treated with vancomycine, and during therapy with ampicillin plus gentamicin in 6 patients of 18 treated.
Marine cyanobacterial mats were cultured on coastal sediments (Nivå Bay, Øresund, Denmark) for over three years in a closed system. Carbonate particles formed in two different modes in the mat: (i) ...through precipitation of submicrometer-sized grains of Mg calcite within the mucilage near the base of living cyanobacterial layers, and (ii) through precipitation of a variety of mixed Mg calcite/aragonite morphs in layers of degraded cyanobacteria dominated by purple sulfur bacteria. The d13C values were about 2‰ heavier in carbonates from the living cyanobacterial zones as compared to those generated in the purple bacterial zones. Saturation indices calculated with respect to calcite, aragonite, and dolomite inside the mats showed extremely high values across the mat profile. Such high values were caused by high pH and high carbonate alkalinity generated within the mats in conjunction with increased concentrations of calcium and magnesium that were presumably stored in sheaths and extracellular polymer substances (EPS) of the living cyanobacteria and liberated during their post-mortem degradation. The generated CaCO3 morphs were highly similar to morphs reported from heterotrophic bacterial cultures, and from bacterially decomposed cyanobacterial biomass emplaced in Ca-rich media. They are also similar to CaCO3 morphs precipitated from purely inorganic solutions. No metabolically (enzymatically) controlled formation of particular CaCO3 morphs by heterotrophic bacteria was observed in the studied mats. The apparent alternation of in vivo and post-mortem generated calcareous layers in the studied cyanobacterial mats may explain the alternation of fine-grained (micritic) and coarse-grained (sparitic) laminae observed in modern and fossil calcareous cyanobacterial microbialites as the result of a probably similar multilayered mat organization.
The effect of lysostaphin from Staphylococcus simulans expressed in Escherichia coli TOP10 strain on Staphylococcus aureus used for inoculation of milk, ground pork and mayonnaise salad was ...investigated. The populations of this pathogen in ultrahigh-temperature milk preserved at 4C by lysostaphin added up to concentrations of 1.5 or 3.0 μg/mL were reduced by 0.73 and 0.92 log(cfu/mL) in control samples without enzyme addition. The protective influence of lysostaphin was diminished in case of milk storage (20C) prolonged up to 24 h. Furthermore, a final reduction level by 0.92 log(cfu/mL) was achieved after 24 h of pork storage. The smaller and more dependent on enzyme concentration inactivation of S. aureus was observed in the case of the mayonnaise salad, and it led to the conclusion that some food components or proteolytic enzymes originating from other bacteria caused lysostaphin inactivation.
Eradication of Pseudomonas aeruginosa (P.a.) in patients with cystic fibrosis (CF) is possible if it is initiated in the early course of infection. Therefore, the detection of P.a. as early as ...possible is an important goal of care. Regular determination of antibodies to P.a. antigens in serum may be useful in patients who have not yet been infected or were infected intermittently. The aim of the present study was to assess the concentrations of antibodies to selected antigens of P. aeruginosa in the serum of children with CF and with known status of P.a. infection.
The study was performed in 111 CF patients (27 not infected with P. aeruginosa, 29 with intermittent infection and 55 with chronic infection). The concentrations of IgG antibodies to the alkaline protease (AP), elastase (ELA) and exotoxin A (Exo-A) were measured. The increased concentration of antibodies was defined as exceeding 500 units (according to the manufacturer). The results of antibodies assessment were analysed according to previous infection status and the results of present culture.
At the time of the study, P.a. was cultured from sputum of 57 patients: 9 out of 29 (31%) with intermittent infection, and 48 out of 55 (87%) with chronic infection. Increased concentrations of antibodies to one or more P.a. antigens were found in 60 patients, and to all three types of antigens in 30 patients. Increased serum antibody concentration was found significantly more often in the patients with chronic P.a. infection compared to those with intermittent infection (82% vs. 35%, p = 0.0001). In the patients with chronic P.a. infection (especially with mucoid type), serum antibody concentrations were significantly higher than in other patients. Higher concentrations of antibodies were also found in the patients with positive result of P.a. culture at the time of the study, compared to those with negative culture. In 19% of patients not infected with P.a., increased serum antibodies to at least one P.a. antigen were found. The clinical significance of such findings is unclear and needs further investigation.
In the present study, the increased serum concentrations of IgG antibodies to P. aeruginosa antigens (AP, ELA and Exo-A) were found most often in the patients with chronic P.a. infection and in those in whom P.a. (especially mucoid type) was cultured at the time of the study. The clinical significance of the elevated antipseudomonal antibodies level in 19% of the patients never infected with P.a. is unclear and needs further investigation.
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