Neutrophil phagocytosis, reactive oxygen intermediate production (intra-and extracellular), neutrophil bactericidal activity, and chemotaxis/chemokinesis were assessed in three age groups: 21-36, 38-56, and 62-83 years. A significant age-dependent reduction in the number of phagocytized Escherichia coli per neutrophil (measured by acridine orange staining) and Staphylococcus aureus phagocytosis (measured by flow cytometry) was seen (r ؍ 0.669 and r ؍ 0.684, P F 0.001 for both). These findings correlated with an agedependent increase in intracellular calcium concentrations in resting neutrophils (r ؍ 0.698, P F 0.001) and a reduced hexose uptake (r ؍ 0.591, P F 0.01). In addition, a significant reduction in the intracellular reactive oxygen production was seen after stimulation with S. aureus (P F 0.001) with increasing age. In contrast, no differences between the groups in reactive oxygen production was seen after stimulation with E. coli. The neutrophil bactericidal activity was impaired with increasing age (64 ؎ 4% of the phagocytized bacteria were killed in group 1; 66 ؎ 2 in group 2, and 59 ؎ 6 in group 3; P F 0.01). In addition, a trend toward a reduced neutrophil chemotaxis was seen with increasing age (P ؍ 0.022). The findings suggest that increased intracellular calcium concentrations in resting neutrophils and/or a reduced hexose uptake result in reduced phagocytic ability and decreased bactericidal activity of neutrophils in the elderly. J. Leukoc. Biol. 67: 40-45; 2000.
Our results imply that omeprazole impairs production of reactive oxygen intermediates by neutrophils. Whether specific impairments of neutrophil host defenses occur in vivo remains uncertain. Reduced bactericidal activity is associated with an increase of intracellular Ca2+ concentrations in resting neutrophils.
To quantitatively assess the role of Candida species in antibiotic-associated diarrhea (AAD), stool samples from a total of 395 patients and control subjects were cultured in differential isolation medium: 98 patients had AAD, 93 patients were taking antibiotics but did not have diarrhea (A(+)D(-)), 97 patients were not taking antibiotics but had diarrhea (A(-)D(+)), and 107 patients were control subjects (A(-)D(-)). In addition, secreted aspartyl proteinase (Sap) production was tested. In AAD patients, Candida positivity (77/98) and Candida overgrowth (62/98) were not different from that among A(+)D(-) patients (75/93 [P= .860] and 52/93 [P= .375], respectively). Candida overgrowth among A(-)D(+) patients (40/97, P= .003) was less frequent than among AAD patients, but Candida positivity was not different (80/97, P= .612). In control subjects, Candida positivity and overgrowth were less common than in all other groups. Production of Sap did not differ between patients with AAD and control subjects (P= .568 and P= .590, respectively). Data indicate that elevated Candida counts are a result of antibiotic treatment or diarrhea rather than a cause of AAD.
A retrospective survey of candidaemia between 2001 and 2006 was performed at the University Hospital of Vienna, a 2200-bed centre with large organ transplantation and haematology-oncology units. The incidence rate of Candida spp. in blood cultures increased from 0.27 cases/1000 admissions in 2001 to 0.77 cases/1000 admissions in 2006 (p <0.005). The incidence of candidaemia caused by Candida albicans and by non-albicans Candida spp. both increased during this period; although there was a trend towards an increased incidence (37%) of non-albicans Candida spp., particularly Candida glabrata, in surgical wards, C. albicans remained the predominant pathogen (63%). In the haematology-oncology unit, C. albicans remained the leading pathogen (23/29 isolates, 79%), followed by Candida tropicalis and C. glabrata (2/29, 7% each), Candida sake and Candida lusitaniae (1/29, 3% each). The overall survival rate was 43.8%, ranging from 32.8% in 2004 to 63.6% in 2002. In total, 108 (33.2%) patients died within 4 weeks of the first isolation of Candida spp. from blood; 58 (54%) of these patients died within the first 7 days, and a further 34 patients died within the next 3 months. Fluconazole was used extensively (24 701.5 defined daily doses), followed by amphotericin B (8981.4 defined daily doses), during 2005. The consumption of antifungal agents increased continuously (p <0.05) because of increased use of voriconazole and caspofungin. Although the numbers of susceptible patients remained unchanged, the net increase in the number of cases of candidaemia warrants a re-evaluation of the risk-factors and the use of improved diagnostic procedures for invasive fungal infections.
The formation of cold agglutinins is frequently observed during Mycoplasma pneumoniae infections. Nevertheless, severe hemolysis is exceptional. We report a case of life-threatening hemolytic anemia caused by M. pneumoniae. As the leucocyte count was excessively elevated, the differential diagnosis primarily comprised hematological malignancies. The presence of cold agglutinins indicated the correct diagnosis, which was confirmed by highly elevated levels of both IgG and IgM antibodies to M. pneumoniae and a chest X-ray suggestive of atypical pneumonia. The patient was treated with roxithromycin and showed a favorable recovery within ten days after admission. This case demonstrates that, even in patients with clinically mild pneumonia, M. pneumoniae may be the cause of severe anemia.
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