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Biomedical subjects

A von Graevenitz

Publications and source records attributed to A von Graevenitz.

At least 19 recordsLinked to original sources
PubMed1992

[Swiss quality control in bacteriology and mycology 1989-1991].

Since 1983 there has been a voluntary quality assessment scheme (QAS) for bacteriology and mycology laboratories in Switzerland directed by the Committee for Quality Control of the Swiss Society for Microbiology. For the first time, the results of this QAS for the period between 1989 and 1991 are made available to a wider public. During the period in question, a steadily increasing number of participants received three samples containing microorganisms four times a year for identification and susceptibility testing. A mean percentage value of a point rating, with a maximum of 12 points, was calculated every year for each laboratory. Values of < or = 75% were defined as insufficient. For a first evaluation, laboratories were assigned to the categories of cantonal (and university) laboratories (C/U), private laboratories (P), and hospital laboratories (H, in hospitals which are neither university nor other tertiary care centres). Significant differences were detected between C/U and P on the one hand and H on the other. As a rule, H obtained poorer results than the two categories, examined fewer specimens, and their percentage with results < or = 75% was significantly higher. The second evaluation classified laboratories according to their recognition by the Swiss Federal Department of Public Health (FDPH). For statistical reasons, H had to be grouped with C/U. Nevertheless, their share of non-recognized laboratories was exceedingly high (15 out of 17 participants in 1991). Recognized laboratories constantly showed a better performance than non-recognized laboratories, examined more specimens, and their number of laboratories obtaining results < or = 75% was much lower.(ABSTRACT TRUNCATED AT 250 WORDS)

Accreditation↗
PubMed1992

Epidemiology and clinical significance of nontuberculous mycobacteria in patients negative for human immunodeficiency virus in Switzerland.

Over the last decades, the rate of isolation of tubercle bacilli has declined in the developed countries, while the incidence of infection with nontuberculous mycobacteria (NTM) has increased. In a retrospective study, we analyzed all cases of patients negative for human immunodeficiency virus (HIV) and from whom NTM were isolated in the Zurich area of Switzerland from 1983 to 1988. During the 6-year study period, 513 patients infected with NTM were identified, 34 of whom had clinically significant disease. The presentation of mycobacteriosis was found to be lung disease in 23 cases, soft-tissue disease in 10 cases, and disseminated disease in one case. The highest attack rate of pulmonary mycobacteriosis was 0.49% and was found in the group of patients 41-50 years old. During the 6-year period, the incidence of tuberculosis declined from 16.2 to 13.2 per 100,000 population, while the incidence of mycobacteriosis increased from 0.4 to 0.9 per 100,000 population. Clinically nonsignificant NTM isolates were found more frequently in patients with chronic lung diseases (P less than .01) and especially in patients with a history of tuberculosis (P less than .001).

Adolescent↗
PubMed1992

In vitro activities of Ro 40-6890 against 164 predominantly intestinal members of the families Enterobacteriaceae and Vibrionaceae.

The in vitro activities of Ro 40-6890, the active metabolite of a novel orally absorbable cephalosporin ester, Ro 41-3399, against 164 nonfastidious aerobic gram-negative rods of predominantly intestinal origin from patients with diarrhea were evaluated by the agar dilution method recommended by the National Committee for Clinical Laboratory Standards. Ro 40-6890 was inhibitory (MIC for 90% of isolates [MIC90], 0.12 micrograms/ml) against the majority of intestinal members of the families Enterobacteriaceae and Vibrionaceae (Vibrio spp., Aeromonas spp., and Plesiomonas shigelloides). The potency of Ro 40-6890 was very similar to that of cefotaxime (MIC90, 0.12 micrograms/ml) and distinctly higher than those of cefadroxil (MIC90, > or = 128 micrograms/ml) and amoxicillin-clavulanic acid (MIC90, 32 micrograms/ml-2 micrograms/ml).

Amoxicillin↗
PubMed1992

Microbiological aspects of peritonitis associated with continuous ambulatory peritoneal dialysis.

The process of continuous ambulatory peritoneal dialysis has provided a useful, relatively inexpensive, and safe alternative for patients with end-stage renal disease. Infectious peritonitis, however, has limited a more widespread acceptance of this technique. The definition of peritonitis in this patient population is not universally accepted and does not always include the laboratory support of a positive culture (or Gram stain). In part, the omission of clinical microbiological findings stems from the lack of sensitivity of earlier microbiological efforts. Peritonitis results from decreased host phagocytic efficiency with depressed phagocytosis and bactericidal capacity of peritoneal macrophages. During episodes of peritonitis, fluid movement is reversed, away from the lymphatics and peritoneal membrane and toward the cavity. As a result, bloodstream infections are rare. Most peritonitis episodes are caused by bacteria. Coagulase-negative staphylococci are the most frequently isolated organisms, usually originating from the skin flora, but a wide array of microbial species have been documented as agents of peritonitis. Clinical microbiology laboratories need to be cognizant of the diverse agents so that appropriate primary media can be used. The quantity of dialysate fluid that is prepared for culture is critical and should constitute at least 10 ml. The sensitivity of the cultural approach depends on the volume of dialysate, its pretreatment (lysis or centrifugation), the media used, and the mode of incubation. The low concentration of microorganisms in dialysate fluids accounts for negative Gram stain results. Prevention of infection in continuous ambulatory peritoneal dialysis patients is associated with the socioeconomic status of the patient, advances in equipment (catheter) technology, and, probably least important, the application of prophylactic antimicrobial agents.

Bacteria↗
PubMed1992

Pseudoepidemic of nontuberculous mycobacteria due to a contaminated bronchoscope cleaning machine. Report of an outbreak and review of the literature.

We describe a pseudoepidemic due to nontuberculous mycobacteria contaminating the water tank of a machine used to clean and disinfect fiberoptic endoscopes. Forty-six bronchoscopies performed on 41 patients during a six-month period yielded 16 specimens positive for acid-fast bacilli (AFB). One specimen showed Mycobacterium avium complex from an AIDS patient and one, M tuberculosis from a patient with active cavitary tuberculosis. In four patients, only the smears showed AFB; subsequent cultures remained negative. Of the rest, seven contained M chelonae and three M gordonae, all in patients with no clinical signs of mycobacterial disease. Two of the three M gordonae isolates represented laboratory contamination from an antimicrobial solution in a culture medium. Four patients in the beginning of the pseudoepidemic were treated for presumed tuberculosis until negative culture results were available. Control of the "outbreak" was achieved by regular disinfection of the implicated water tank in the cleaning machine. Contamination of bronchoscopes with nontuberculous mycobacteria can lead to unnecessary diagnostic and therapeutic interventions.

Bronchoscopy↗
PubMed1990

Persistent colonization of carbon dioxide incubators with Candida parapsilosis.

Recurrent contamination of bacteriological specimens with Candida parapsilosis led to epidemiological investigations which indicated persistent colonization of carbon dioxide incubators as the most likely source. Changes in the technical arrangements and institution of a meticulous cleansing protocol eliminated contamination of specimens but not colonization of the incubators. Tests for tolerance of 17% NaCl and survival at 50 degrees C, and SDS-PAGE analysis of crude cell extracts allowed discrimination between epidemic and non-epidemic isolates, while enzyme profile analysis and susceptibility studies failed as typing methods.

Candida↗
PubMed1989

Automated analysis of 35-S-methionine labeled proteins by SDS-PAGE as a typing method in a suspected cluster of Serratia marcescens.

During a nine-month period in 1986, we observed five ornithine decarboxylase-negative isolates of Serratia marcescens from four different patients. All isolates were identical in more than 50 biochemical parameters. Four isolates from three hospitalized patients were essentially identical in their susceptibility patterns to 12 antimicrobial agents. Analysis of 35-S-methionine labeled whole cell proteins by SDS-PAGE with the AMBIS system (Automated Microbiology System Inc., San Diego, CA) suggested that only three of these isolates were identical while the fourth hospital strain was more closely related to the isolate of a patient with no contact to the hospital. These results were confirmed by bacteriocin- and serotyping. We conclude that analysis of these protein patterns--which does not require special reagents - was an adequate method for typing S. marcescens.

Bacterial Proteins↗
PubMed1989

In vitro activity of cefteram against predominantly enteropathogenic and glucose nonfermentative gram-negatives.

Cefteram (T-2525), the free acid of the orally active cephalosporin ester cefteram pivoxil, was tested in vitro against 355 gram-negative clinical isolates of enteropathogenic and nonfermentative species. The compound was several times more active (w/w) against isolates belonging to the enteropathogenic Enterobacteriaceae and Vibrionaceae than against those belonging to the nonfermentative rods (excluding Pseudomonas aeruginosa).

Cefmenoxime↗
PubMed1988

Branhamella catarrhalis: fatty acid and lipopolysaccharide analysis of an atypical strain from blood culture.

A Branhamella catarrhalis-like organism was isolated from blood cultures; it was atypical in showing negative nitrate and nitrite and positive gamma-glutamylaminopeptidase reactions, in agglutinating with Neisseria meningitidis antisera, and in forming butyrous colonies. Cell-wall fatty-acid and lipopolysaccharide analysis provided evidence that this isolate was an atypical B. catarrhalis.

Bacterial Infections↗