Comparison of ciprofloxacin with ampicillin in acute infectious exacerbations of chronic bronchitis. A double-blind crossover study.

Two separate acute bacterial exacerbations of chronic bronchitis and/or asthma were treated in 22 patients in a double-blind crossover study. One course of treatment consisted of 750 mg of ciprofloxacin twice daily and the other of 500 mg of ampicillin four times a day; each drug was given for 14 days. Patients were observed initially, every three to four days during therapy, and weekly during the post-therapy period. Observations that were recorded included graded chest symptoms and physical findings, vital signs, hematologic parameters, and objective sputum measurements (daily volume, purulence, differential quantitative cytology, bacterial counts, and physical properties). Both antibiotic regimens were effective in resolving these acute bacterial exacerbations. Paired t test analysis revealed that ciprofloxacin is as clinically effective as ampicillin in the treatment of acute bacterial exacerbations in chronic bronchial disease, and appears to be superior in clearing bacterial pathogens from the sputum.

Concentration of Mycobacterium avium by hospital hot water systems.

Water from 34 sites on two temporarily vacant hospital floors was analyzed for the presence of mycobacteria. These sites included 18 cold water taps and 16 hot water taps, including shower heads. A total of 14 sites (41%) demonstrated the presence of Mycobacterium avium as confirmed by biochemical characterization, DNA/rRNA probe analysis, and seroagglutination. Of positive sites, 11 were hot water sources with an average temperature of 55 degrees C and yielding up to 500 colony-forming units per 100 mL. Seven of 11 strains analyzed for glycolipid antigens were identified with the type 4 serovar, the preponderant serovar of M avium in patients with acquired immunodeficiency syndrome from the Boston area. Potable hot water systems, particularly those that generate aerosols, may contain concentrations of M avium greater than those found in cold water systems and could serve as an environmental source for colonization and infection of immunocompromised persons.

Mycobacteria in public water supplies: comparative resistance to chlorine.

The isolation of mycobacteria from municipal and hospital water supplies prompted an investigation of the susceptibility of environmental and clinical isolates of mycobacteria other than Mycobacterium tuberculosis and Mycobacterium bovis to free chlorine. Experiments revealed that free chlorine concentrations of 1.0 mg l-1 eliminated 100,000 c.f.u. of the mycobacterial strains tested within 8 hours of exposure, whereas a concentration of 0.15 mg l-1 had virtually no bacteriocidal effect. Free chlorine residual levels of 0.1 mg l-1 or less, depending on the water temperature, within Boston, suggest that current disinfection procedures may not be adequate for effective control of potentially pathogenic mycobacteria in public water supply systems serving a population with increased risk factors.

Mycobacterium avium complex, an emerging pathogen in Massachusetts.

We report a study of 1,953 patients whose laboratory records from 1972 through 1983 at the Massachusetts Mycobacteria Reference Laboratory indicated the isolation of Mycobacterium avium complex (MAC) organisms. At least one clinical specimen from each patient during this period exhibited the organism. The incidence of isolation of MAC has increased fivefold since 1972, with a doubling of the number of patients with positive MAC specimens from normally sterile sites occurring since 1980. A concomitant increase of more than fourfold in other nontuberculous mycobacteria has occurred. Most isolates came from high-density population centers. Communities whose drinking water comes from a distant rather than a local source were more likely to have patients with MAC.

Detection of pneumococci in blood cultures by latex agglutination.

Latex agglutination by use of the Pneumoslide test on clinical blood cultures detected 22 Streptococcus pneumoniae strains as the etiological agents in 47 streptococcal septic episodes. The other 25 isolates were identified as viridans streptococci or streptococci of groups A, B, D, or G. The test demonstrated 100% sensitivity, 92% specificity, and predictive values for positive and negative reactions of 91 and 92%, respectively. Two false-positive reactions were caused by strains of viridans streptococci. The two strains continued to give positive reactions when colonies from blood agar plates were tested according to the instructions of the manufacturer. This latex agglutination test is an effective tool for the rapid diagnosis of pneumococci in blood cultures.

Mycobacterial cervical lymphadenopathy. Relation of etiologic agents to age.

Age-related differences in etiology were examined in 214 instances of mycobacterial cervical lymphadenopathy. In adults, Mycobacterium tuberculosis was isolated from 147 lymph nodes and "atypical" mycobacteria was isolated from seven nodes. In contrast, M tuberculosis was isolated from only five nodes from children while other mycobacteria were isolated from 55 nodes. Mycobacterium tuberculosis clearly preponderates as the cause of mycobacterial cervical adenitis in adults while other mycobacteria are the cause of most cervical adenitis in children. The preponderance of Mycobacterium avium-intracellulare in cervical adenitis in children contrasts with reports of Mycobacterium scrofulaceum as the most frequent causative agent in other geographic areas and may reflect either a change in causative agents or geographic differences. However, the finding of M tuberculosis in 8% of nodes indicates that other mycobacteria cannot be assumed to be the only cause of this disease in children.

Isolation of acid-fast organisms from surgical specimens.

A total of 204 surgical specimens positive for acid-fast organisms yielded 169 strains of Mycobacterium tuberculosis, 15 of which were isolated by Middlebrook 7H-9 broth medium only. Mycobacteria other than M. tuberculosis were isolated from 33 specimens, and Nocardia asteroides was isolated from 2 specimens.

Use of cetylpyridinium chloride in the decontamination of water for culture of mycobacteria.

Selective decontamination of large-volume aqueous samples for mycobacterial culture can be achieved with overnight exposure to 0.04% cetylpyridinium chloride.

Experimental alimentary infection of anole lizards (Anolis carolinensis) with Mycobacterium ulcerans.

Pathogenic Mycobacterium ulcerans were recovered from the stool of anole lizards up to 11 days after inoculation by stomach tube. M. ulcerans was isolated from the liver of 3 of 20 lizards and acid fast bacteria were seen in the mucosa of intrahepatic bile ducts in 2 of these 10 weeks post-inoculation. These results provide equivocal support for our hypothesis that herpetofauna are a reservoir of infection with M. ulcerans.

Emergence of rifampin-resistant Mycobacterium tuberculosis in Massachusetts.

Tests of sensitivity to rifampin of over 2,200 strains of Mycobacterium tuberculosis demonstrated a progressive increase in the number of rifampin-resistant isolates during the past four years in Massachusetts. No resistant strains were isolated in 1971, but two strains resistant to 1 mug of rifampin/ml were isolated in 1972. Nine rifampin-resistant strains were isolated in 1973 and 16 were isolated in 1974. All but two of the resistant strains were isolated from patients who had received therapy for tuberculosis and had demonstrated resistance to other antituberculous agents. Rifampin-resistant strains were isolated from two patients, however, who had not received prior chemotherapy. Both strains were fully susceptible in vitro to other antituberculous drugs.

Experimental infection of anole lizards (Anolis carolinensis) with Mycobacterium ulcerans by the subcutaneous route.

To test whether herpetofauna could be a laboratory model for Mycobacterium ulcerans, 21 anole lizards were inoculated subcutaneously with viable M. ulcerans, 21 with autoclaved organisms, and 14 with an aqueous solution of 0.01% Tween 80. M. ulcerans was recovered in culture from the slowly progressive lesions which developed at the inoculation site in lizards receiving the viable bacteria. Progressive lesions did not occur in the two control groups. Three patterns of inflammatory response to viable M. ulcerans were observed: 14 lizards developed a diffuse, granulomatous reaction in which acid fast bacilli (AFB) were predominantly intracellular; 1 developed focal, encapsulated granulomas; 5 developed a diffuse, necrotizing granulomatous response in which most AFB were extracellular--similar to the characteristic lesion found in human infections.

Rapid identification of the taxon Rhodochrous in the clinical laboratory.

Degradation of ethylene glycol in Middlebrook 7H-10 agar medium by 26 out of 29 strains of the taxon rhodochrous seems to permit its separation from rapidly growing mycobacteria and certain actinomycetes which only exceptionally showed this property.

Purified protoplasmic peptides of mycobacteria: chemical composition of a tuberculin-active glycopeptide.

A tuberculin-active glycopeptide containing eight different amino acids and glucose was isolated from the protoplasm of Mycobacterium tuberculosis. A molecular weight of 4,000 to 5,000 was established by Sephadex gel filtration; other analyses showed a peptide to carbohydrate ratio of 9:1. These observations suggest a tentative composition of 3 to 4 residues of glucose, 12 residues each of aspartic and glutamic acids, 3 residues each of lysine, glycine, and serine, and 1 residue each of arginine, threonine, and alanine.

Purified protoplasmic peptides of mycobacteria: isolation of species-specific peptides from protoplasm of mycobacteria.

Infections with mycobacteria other than tubercle bacilli are responsible for a variable percentage of cross-reactions to tuberculin. Two major suggestions for circumventing this problem have been made: the first, development of a quantitative tuberculin test, is based on the fact that most cross-reactions are smaller than those caused by true tuberculous infections; the second, preparation of purified skin test antigens from other mycobacteria, is based on the hope that greater specificity will be displayed by homologous sensitin. Effort so far has been focused on the culture filtrates as the source of antigen. This article describes the preparation of low molecular weight purified protoplasmic peptides (PPP) of specificity and sensitivity superior to purified protein derivatives.