Sputum Isolates Research Articles

Endemic aminoglycoside resistance in gram-negative bacilli: epidemiology and mechanisms.

Isolates of gentamicin-resistant gram-negative bacilli from clinical specimens peaked at nine to 10 per month in 1973-1974. Instituting barrier-type precautions during 1974-1977 was associated with a sustained 87% reduction in resistant Enterobacteriaceae. The number of resistant Pseudomonadaceae fell temporarily by 28%, paralleling gentamicin usage. During an endemic 15-month period in 1976-1977 nonenzymatically mediated resistant Pseudomonas aeruginosa often emerged after aminoglycoside therapy in patients who had prior carriage of sensitive strains of the same serotype (P = 0.002); this resistance was associated with wound or sputum isolates (P = 0.003). Resistant Enterobacteriaceae more often demonstrated the converse, that is, spread of urinary tract isolates with enzymatically mediated resistance from patients not on aminoglycoside therapy. These findings suggest that control measures to minimize occurrence of resistant bacilli include barrier-type precautions for patients with resistant Enterobacteriaceae, evaluation of transfers and readmissions as a source of resistant organisms, and reduction of aminoglycoside use to decrease the selection of nonenzymatic resistance.

Insignificance of colonic bacteria in the sputum of patients in a new ICU.

Over a 12-month period, 27% of patients in a new ICU grew bacterial pathogens from sputum or tracheal cultures. The commonest isolates were Pseudomonas aeruginosa and Klebsiella species. Endotracheal intubation, the length of time intubated, and antimicrobial therapy all predisposed to the isolation of organisms from sputum. No patient developed a gram-negative pneumonia, and there was no case of septicemia associated with a positive sputum culture. The presence of epithelial or pus cells in sputum was unrelated to the culture results. It was concluded that the growth of colonic bacteria from sputum or tracheal aspirates was of little prognostic or clinical significance. No significant common environmental site or cross-infection pathway was identified: sinks were contaminated by patients rather than vice versa. Most sputum isolates were probably endogenous in origin.

Aspergillosis and atopy in cystic fibrosis.

Forty-six patients with cystic fibrosis (CF) were studied for colonization and sensitization by Aspergillus organisms. The fungus was cultured from 21 of 37 (57%) patients who produced sputum. The non-CF sputum isolation rate was 6.5%. Sputum hyphae were seen in 95% of patients with positive cultures. Sputum eosinophilia accompanied colonization by Aspergillus. Aspergillus precipitins were found in 37% of CF patients; positive immediate skin tests were found in 39%. "Atopy" defined by skin test criteria was found in 46%. All of these findings were more common in patients with more severe disease (p less than 0.05). CF patients had predominant mold sensitivity in contrast to predominant pollen sensitivity in a control group of asthmatic subjects. Serum IgE concentrations were increased in 22% of CF patients. CF patients who had increased serum concentrations of IgE were more likely to have a family history of atopy. Wheezing was more common in those who were atopic, especially the group with predominant mold sensitivity who had more severe disease. Four patients fulfilled the diagnostic criteria for allergic bronchopulmonary aspergillosis (ABPA) during the time of study and follow-up. A fifth patient had ABPA diagnosed before the study. The incidence of ABPA during a 2-yr period in our CF population was 11%.

Identification and grouping of Neisseria meningitidis directly on agar plates by coagglutination with specific antibody-coated protein A-containing staphylococci.

It has been shown that Neisseria meningitidis can be grouped by coagglutination directly upon growth on sheep blood or chocolate agar plates. All positive reactions were group specific, and only a single colony was required for a positive reaction. There was variation seen in the effectiveness of commercial antisera in preparing sensitive reagents. Certain throat and sputum isolates of group Z organisms failed to react by coagglutination, although they would react directly with antiserum in whole-cell agglutination. This problem remains unresolved but may not be greatly significant in laboratory use of this method since group Z is rarely associated with disease.

The pathogenicity of mycobacterium fortuitum and mycobacterium chelonei in man: A report of seven cases

The clinical records of 7 patients referred to the National Jewish Hospital and Research Center over a 6-year period for evaluation of an abnormal chest x-ray and repeated sputum isolates of rapidly growing mycobacteria (Runyon's Group IV) were reviewed to determine the potential pathogenicity of these organisms. Mycobacterium fortuitum was isolated from 5 patients and Mycobacterium chelonei from 2. Haemoptysis, cough and weight loss were prominent in 6. Three had rheumatoid arthritis. Although two demonstrated cutaneous anergy, lymphocyte responsiveness to PHA was normal. PPD-F was not useful in skin testing or in the in vitro evaluation of lymphocyte function. Histologic examination of the lungs of 2 patients demonstrated caseating granulomata. One patient died of massive pulmonary haemorrhage soon after initiation of therapy. Multi-drug treatment regimens generally resulted in progressive sterilization of the sputum and improvement in the appearance of the chest x-ray. We conclude that some rapidly growing mycobacteria can cause potentially fatal cavitary lung disease and that intensive anti-tuberculosis therapy may successfully alter its course.

Clinical significance of casual isolation of acid-fast organisms from sputum of tuberculous patients.

Approximately 70 per cent of acid-fast organisms that appeared as casual isolates in the sputum of 40 patients 6 months or later after Mycobacterium tuberculosis had been eliminated from their sputum by chemotherapy were mycobacteria other than Mycobacterium tuberculosis. All of the patients had advanced pulmonary tuberculosis with chronic cavities.

SOURCES OF PSEUDOMONAS ÆRUGINOSA INFECTION IN A RESPIRATORY/SURGICAL INTENSIVE-THERAPY UNIT

Monitoring of pseudomonas pyocine types from 640 patients and their environment was undertaken in a respiratory/surgical intensive-therapy unit (R.S.I.T.U.) during a nineteen-month period. Forty of fifty-six sputum or throat isolates of pseudomonas were clearly hospital acquired and at least 10 of the 16 patients who had Pseudomonas œruginosa on first culture were suspected of having hospital-acquired organisms. Pyocine types 1 and 10 were the "resident" strains; type-10 outbreaks occurred in clusters. Both types were regularly cultured from only one environmental source (the sinks), even during one to two week intervals during which no patients in the R.S.I.T.U. were colonised with pseudomonas. It is suggested that the sinks provide reservoirs of pseudomonas infection and that the hands of personnel are the vehicles of transmission.

PNEUMONIA IN NEW GUINEA: II. PNEUMOCOCCAL SEROTYPES AND THE POSSIBLE UTILITY OF POLYVALENT VACCINES OF CAPSULAR POLYSACCHARIDES

Isolates of Pneumococcus obtained from sputum samples and blood cultures of 276 adult patients suffering from pneumonia were typed by the Quellung reaction using the 46 Danish antisera of Lund. All isolates were typable. Types 1, 3, 5, 7, 8, 19 and 46 accounted for 57% of 244 sputum isolates and 68% of 50 blood culture isolates. Type 1 bacteremia was present in five of the six patients who died. The serotypes obtained fom patients with multisegmental and unisegmental pneumonia tended to differ from those isolated from patients with bronchopneumonia and those who had clinical signs suggesting alveolar infection, but from whom a clear chest X-ray film was obtained. Available evidence suggests that the number of highly invasive pneumococcal serotypes Is quite small, and that vaccination of high-risk populations with capsular antigens of these serotypes may offer an important preventive approach.