Pneumococcal pneumonia in adult hospitalized patients infected with the human immunodeficiency virus.

PURPOSE: To determine the attack rate; clinical, radiologic, and laboratory characteristics; and outcome of pneumococcal pneumonia in patients infected with the human immunodeficiency virus (HIV) and to compare these characteristics with those of pneumococcal pneumonia in the general population. PATIENTS AND METHODS: This is a retrospective (13-month), prospective (14-month) study. All adult hospitalized patients with pulmonary infiltrates and isolation of Streptococcus pneumoniae in blood, pleural fluid, transtracheal aspirate, or respiratory secretions obtained by plugged telescoped catheter (counts greater than 10(3) colony-forming units per milliliter) are included. MAIN RESULTS: We identified 22 HIV-infected patients and 84 HIV-seronegative patients with pneumococcal pneumonia (76% and 56%, respectively, were bacteremic). The estimated attack rate was 5.9 per 1000 for HIV-infected patients and 0.31 per 1000 for HIV-seronegative patients. Pneumococcal pneumonia was the first manifestation of HIV infection in 48% of cases. Seventy-two percent of patients younger than 40 years of age with pneumococcal pneumonia were HIV infected. No predisposing factors for pneumococcal pneumonia were identified in 76% and 2% of HIV seropositive and seronegative patients, respectively. Clinical and radiologic presentation was similar in the two populations. Of all S pneumoniae isolates, 35% were resistant to penicillin and 10% to erythromycin, without differences in the two groups. Prognosis was good, with only one infection-related death in the HIV-infected group (10 patients died in the other group). No relapses were documented in HIV-infected patients. CONCLUSION: The HIV-infected patient is at increased risk for pneumococcal pneumonia and bacteremia. Patients younger than 40 years of age who present with pneumococcal pneumonia should be considered for HIV testing, since it may be the first manifestation of HIV infection. Specific antimicrobial therapy is curative in the majority of HIV-infected patients.

Susceptibility of Streptococcus pneumoniae to penicillin: a prospective microbiological and clinical study.

We performed a prospective study of all infections with Streptococcus pneumoniae documented during a 22-month period at our hospital. A total of 163 clinically significant strains of S. pneumoniae were isolated from 139 patients whose ages ranged from 8 days to 91 years (mean +/- SD, 42.6 years +/- 26.8 years). Twenty percent of the patients had cancer, and 18% were infected with the human immunodeficiency virus. Pneumococcal infection was nosocomially acquired in one-fourth of cases. One-third of patients had nonpneumonic disease. A wide range of serotypes were isolated, and 42.5% of all strains were nonsusceptible--i.e., showed either intermediate or high-level resistance--to penicillin. The rates of resistance to chloramphenicol, erythromycin, and tetracycline were 23%, 10.8%, and 48.2%, respectively. Twenty-two percent of the infected patients died, with a 15.8% mortality directly attributable to pneumococcal infection. Factors associated with infection by strains of S. pneumoniae not susceptible to penicillin included an age of less than or equal to 10 years, immunosuppression, the presence of a rapidly fatal underlying disease, previous antimicrobial therapy, and infection by serotypes 14 and 23. All clinically significant isolates of S. pneumoniae should be submitted for antimicrobial susceptibility studies, and, whenever a high prevalence of resistance to penicillin and macrolides is detected, the use of these well-established empirical therapeutic regimens should be reconsidered.

High incidence of tuberculosis in renal patients.

The incidence and clinical characteristics of mycobacteriosis in patients attending the nephrology department in a hospital in Madrid, Spain, during a 30-month period were analysed retrospectively. Twenty-two new cases of tuberculosis were detected among 525 patients studied. No cases of clinically significant atypical mycobacteriosis were found. The estimated overall annual incidence of tuberculosis in these patients was 259 cases per 100,000 population, which is much higher than the national annual incidence in Spain of 35 per 100,000 population. Most cases were asymptomatic when diagnosed and extrapulmonary involvement was the rule (86% of all patients). In areas with a high prevalence of tuberculosis, renal patients in high-risk groups (renal transplant recipients, haemodialysis and CAPD patients) should be examined periodically to exclude silent infection.

Comparison of the A-T rich regions and the Bacillus subtilis RNA polymerase binding sites in phage phi 29 DNA.

By using a modification of the BAC spreading method for mounting the DNA for electron microscopy, partial denaturation maps of protein-free phi 29 DNA and of phi 29 DNA containing protein p3 were obtained. In phi 29 p3-DNA1 the protein does not seem to influence the melting of the ends of the molecules. The comparison of the partial denaturation map and the B. subtilis RNA polymerase binding sites indicates that five of the seven early promoters (A1, A2, A3, B2 and C2) are located in A-T rich DNA regions whereas the other two early promoters (B1 and C1) are located in less A-T rich sites.