Microbial filtrates activate granulocytes without complement or prostaglandins.

UNLABELLED: Cardiorespiratory dysfunction in sepsis may be mediated by circulating complement, activated leukocytes, prostaglandins, or by a direct effect of endotoxin. The purposes of this study were to determine if pathogenic microbes produce these substances and to evaluate the direct effects of substances released by micro-organisms on granulocyte aggregation (GA). Escherichia coli, (E. coli), Aeromonas hydrophila (Aeromonas h.), Staphylococcus aureus (S. aureus), and Candida albicans, (Candida a.) were incubated in broth to a concentration of 10(9)/ml. Broth was filtered and analyzed by radioimmunoassay for complement components C3a and C5a, thromboxane B2 (TxB), and prostaglandin 6-keto-F1 alpha (PGI) and by the limulus amebocyte lysate test (LAL) for endotoxin. GA, % of maximum zymosan activated aggregation (% max. T), was performed with broth, microbial filtrates, and endotoxin or normal purified human leukocytes in HBSS. Organisms were incubated in broth (B), broth + 0.0135 mg/ml arachidonic acid (BA), and broth + arachidonic acid + indomethacin (BAI). Broth alone was the control (C). RESULTS: C3a, C5a, TxB, and PGI were not detectable in C broth or in any microbian filtrate. LAL was positive in all filtrates, but negative in C broth. GA responses were significantly greater in E. coli (56 +/- 5% max T) and Aeromonas h. (57% +/- 8% max T) compared to S. aureus (10 +/- 5% max T), Candida a. (14 +/- 8% max T) and C broth (1 +/- 1% max T). GA with purified E. coli endotoxin at concentrations measured in the filtrates was not related to the GA responses the original filtrates.(ABSTRACT TRUNCATED AT 250 WORDS)

Prediction of tracheobronchial colonization in current cigarette smokers with chronic obstructive bronchitis.

To help in clarifying the conflicting data on the role of tracheobronchial microflora in chronic bronchitis, the tracheobronchial microflora of a homogeneous group of clinically stable patients with chronic obstructive bronchitis was characterized by transtracheal aspiration. Their mean percentage ratio of forced expiratory volume in 1 sec to the forced vital capacity was 45%. The results were that (1) a bacterial tracheobronchial microflora was present in only 50% of the patients, (2) viridans streptococci were the bacteria most frequently isolated, and (3) the presence or absence of a tracheobronchial microflora was significantly associated with the amount of present cigarette smoking. The fact that patients who smoke less than one pack per day were most likely to have a sterile tracheobronchial tree (P=0.015) implied that there was a critical amount of cigarette smoke that impaired the clearance and/or detoxification of bacteria from the tracheobronchial tree and that it must have been persistently present.

Sampling lower respiratory tract secretions in primary lung abscess: a comparison of the accuracy of four methods.

To determine the relative cultural accuracy of transtracheal aspiration (TTA), wire-brushing under direct vision through a flexible fiberoptic bronchoscope (WBB), and expectorated sputum (ES) in localized pulmonary infections, we compared each method with percutaneous needle lung aspiration (PLA) cultures in patients with peripheral lung abscesses. Of the 27 organisms that PLA cultures isolated from ten lung abscesses (eight aerobic, two anaerobic), TTA identified 81 percent plus an additional five, and WBB 68 percent plus 16. Of the 14 organisms that PLA cultures isolated from eight aerobic abscesses, TTA identified 93 percent plus an additional two, WBB 83 percent plus 12, and ES 71 percent plus 19. From a laboratory standpoint, we concluded the following: (1) when PLA cultures cannot be obtained, the most accurate method for determining the cause of a localized pulmonary infection is TTA generates false-negative and false-positive information, it may not be an appropriate standard to evaluate other methods, such as ES.

An outbreak of acinetobacter infection associated with the use of a ventilator spirometer.

Although respiratory therapy equipment is a well-known source of nosocomial infection, ventilator spirometers have not been previously implicated. We report 17 Acinetobacter calcoaceticus variety anitratus infections traced to contaminated spirometers. Isolates from infected patients were recovered from urine, sputum, wounds, and blood. A review of attack rates for Acinetobacter was prompted by a dramatic increase in blood culture isolates. Prospective surveillance of intensive care environment, personnel, and patients established that Bennett MA-1 spirometers constituted the major reservoir of infecting organisms. Despite daily sterilization, 30% of spirometers in use were found to be contaminated. The hands of 12% of intensive care nurses and 10% of respiratory therapists cultured were found to be colonized. In addition to the infected patients, 28 other patients on spirometer-equipped ventilators were judged to be colonized by Acinetobacter following examination of sputa and/or mouthwashings. Following discontinuation of spirometer use and following increased emphasis on proper handwashing, the incidence of Acinetobacter infections dropped dramatically. Antibiosis in the intensive care environment and a deterioration in aseptic awareness serve to make Acinetobacter an environmental opportunist of increasing importance.

Countercurrent immunoelectrophoresis in the diagnosis of viral infections of the central nervous system.

Countercurrent immunoelectrophoresis was utilized in the study of 621 specimens of cerebrospinal fluid to determine the correlation of detection of viral antigens with the clinical diagnosis of aseptic meningitis and related viral infections. A panel of viral antisera was immunoelectrophoresed against 119 specimens from patients with suspected viral infections of the central nervous system (group I), 32 from patients with bacterial meningitis (group 2), and 470 from patients with no suspected infection of the nervous system (group 3). One or more precipitin bands were detected in 79% of specimens from group 1, 19% from group 2, and 4% from group 3. Paired acute- and convalescent-phase sera from 32 (78%) of 41 patients with precipitin bands detected by countercurrent immunoelectrophoresis demonstrated a fourfold or greater change in complement-fixing antibodies to the detected antigen. With refinements in antisera, countercurrent immunoelectrophoresis may become useful in the rapid laboratory diagnosis of viral infection of the central nervous system.

Deoxyribonucleic acid base composition in the taxonomy of Staphylococcus.

Twenty-four strains of Staphylococcus aureus, including eight known mutants of S. aureus and strains growing under a variety of environmental conditions or exposed to a number of physical and chemical agents, maintained a remarkably narrow range of guanine plus cytosine (GC) content (32.4 to 35.1%). The wide range of GC content (30.7 to 40%) reported in the literature was due to the variety of methods and calculations used rather than to any substantial variation in base composition. The UV-2 "mutant" (ATCC 13680) with a GC content of 67.6% reported to be derived from S. aureus (ATCC 13679) was a species of Corynebacterium. The data presented were consistent with the concept that base composition changes only to a very slight degree by mutation.