Endotoxins of gram-negative anaerobic bacteria.

The author reviews the data available on endotoxins of Fusobacterium, Sphaerophorus, Leptotrichia, and Veillonella species, and reports his own findings with lipopolysaccharides extracted from Bacteroides fragilis strains by the trichloroacetic acid method. The latter extracts showed a very low toxicity for mice after i.v. injection of dosages of less than or equal to 500 micrograms and a slight leucopenic effect in mice after intraperitoneal injection of 50 micrograms.

Search for Acinetobacter calcoaceticus subsp. anitratus: enrichment of fecal samples.

None of 50 healthy individuals and only 2 of 50 hospitalized patients (with Acinetobacter anitratus elsewhere) yielded A. anitratus on enrichment from fecal samples.

[Comparison of antimicrobial activity and stability to beta-lactamases of cefoperazone, cefotaxime, lamoxactam and ceftriaxon]. / Vergleichende Untersuchungen zur antimikrobiellen Aktivität und beta-Lactamasebeständigkeit von Cefoperazon, Cefotaxim, Lamoxactam und Ceftriaxon.

Ceftriaxon (Ro 13-9904) is a new cephalosporin, whose structure resembles cefotaxime. This study compares the minimal inhibitory concentrations (MIC-s) of Ceftriaxon, cefoperazone, cefotaxime, lamoxactam and gentamicin against 622 isolates of various Enterobacteriaceae, non-fermenters and Aeromonas hydrophila. Furthermore the minimal bactericidal concentrations (MBC-s) were determined for some organism; additionally destruction of beta-lactamantibiotics in the presence of beta-lactamases was studied by a bioassay technique. The in vitro activity of Ceftriaxon against gramnegative bacteria was found very similar to that of cefotaxime. The susceptibility of Enterobacter sp. to the three cephalosporines was exceeded by lamoxactam while cefoperazone was the most active beta-lactam-antibiotic against Pseudomonas. Lactamases, which inactivated cefotaxime also destroyed Ceftriaxon in a greater extend. No hydrolysis of lamoxactam and cefoperazone occurred by nearly all bacterial extracts tested.

[Hazards associated with artificial humidification in tracheotomized patients (author's transl)]. / Zur Gefährdung Tracheotomierter durch künstliche Klimatisation Bakteriologische Untersuchungen an einem auf Verdunsterbasis arbeitenden Luftbefeuchter

Bacteriological testing in tracheotomized patients has shown that infection can be avoided when only sterilized water is used for post-surgical humidification and is disinfected at least every two days. In so doing, water condensation can be avoided by the use of concomitant tube heating. Conclusions indicate that humidifers which utilize water evaporation are more useful in patient care than ultra-sonic nebulizers.

[Culture and differentiation of obligatory aerobic gram-negative rods from human material; a scheme for application in routine diagnosis (author's transl)]. / Züchtung und Differenzierung obligat aerober gramnegativer Stäbchen aus menschlichem Untersuchungsmaterial. Schema zur Anwendung in der Routine-Diagnostik

The diagnosis of obligately aerobic Gram-negative rods in the clinical laboratory may encounter difficulties since media used for Enterobacteriacae are only partially usable for the diagnosis of this group of bacteria (Psuedomonas, Xanthomonas, Alcaligenes, Achromobacter, Brucella, Bordetella, Flavobacterium, Moraxella, Acinetobacter, and some still unnamed taxa). We have developed a diagnostic scheme, based on recent publications in the field and representing an extension of earlier tables from this and other laboratories, which attempts to classify a maximal number of obligately aerobic Gram-negative rods with a minimal number of tests. The scheme, employed on 4051 strains, used blood agar and MacConkey Agar as isolation media. Growth characteristics on these media and microscopic morphology may be of help, but only the type of growth on Triple Sugar Iron (or Kligler's) Agar is characteristic for the group as a whole (no growth in the butt, alkalinization or no pH change on the slant). A primary identification series employs tests for oxidase (Kovacs), oxidation of glucose and xylose (in OF medium), deoxyribonuclease and indole (in DNase Test Agar with Methyl Green), nitrate reduction (in Indole Nitrite Medium), motility (hanging drop), and fluorescein production (on Flo Agar). Results of Kirby-Bauer antimicrobial sensitivity testing serve as additional (colistin) or confirmatory criteria. Incubation is at 30 degrees C for 24-48 hrs. If a diagnosis is not possible than, a secondary series, including tests for lysine decarboxylase (tablets), 4 hr urease, esculin hydrolysis, growth at 42 C and on SS Agar, gelatin liquefaction, and flagellar staining may have to be used, and read after 4-24 hrs at 30 degrees C. Five tables, drawn up according to oxidase, glucose, and xylose reactions, serve to identify the species or taxa. Biotypes cannot be differentiated. The scheme will need updating as more knowledge of these bacteria will become available.

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.

[Microkymography--a method to measure the flow velocity in the microvascular bed after endotoxin administration (author's transl)]. / Die Mikrokymographie--eine Methode zur Objektivierung der Geschwindigkeit in der terminalen Strombahn bei Endotoxinwirkung.

In this paper the application of intravital microkymography on studies of the microcirculation of the hamster cheek pouch is presented. Flow velocity reduction which is one of the characteristic initial alterations in small blood vessels after injection of endotoxin is recorded in a direct way by the strip microkymography. The method of the recording system is described and some examples of the effects of endotoxin as well as of serotonin, one of the mediators of endotoxin, are given. The advantage of microkymography in quantitative and functional studies of endotoxic actions, e.g. flow velocity decreases and vessel diameter changes, is discussed.

Pasteurella multocida septicemia not associated with primary liver disease.

Although systemic infections with Pasteurella multocida rarely occur in humans, liver cirrhosis associated with septicemia due to this organism has been frequently reported. Two cases of elderly women with Pasteurella multocida septicemia are described who had diabetes mellitus and breast cancer, respectively. Underlying diseases other than liver cirrhosis as well as factors hitherto unknown in otherwise healthy persons also enhance the risk of Pasteurella multocida septicemia.

Haemophilus influenzae type b septicaemia associated with myonecrosis and thigh abscess.

A case is reported of a male adult with Haemophilus influenzae type b septicaemia and subsequent abscess in the left thigh due to this microorganism following injection of phenylbutazone. The phenylbutazone probably caused muscle cell damage. It is assumed that Haemophilus influenzae type b colonized the site during an episode of septicaemia, with subsequent development of necrosis and abscess.

Ribotyping of coagulase-negative staphylococci with special emphasis on intraspecific typing of Staphylococcus epidermidis.

Coagulase-negative staphylococci (CoNS), particularly Staphylococcus epidermidis, are increasingly being recognized as opportunistic pathogens. They are often multiply antibiotic resistant and can cause nosocomial outbreaks. For clinical and epidemiological reasons, accurate species identification and typing are imperative. Ribotyping, i.e., the generation of characteristic fragment patterns by hybridization of restriction endonuclease fragments of total DNA with labeled standard rRNA from Escherichia coli, has been applied to CoNS for species identification by various investigators. The present study, involving 115 randomly collected clinical isolates of CoNS, provides ambiguous evidence with respect to those findings. Eighty six S. epidermidis strains were ribotyped intraspecifically. Eleven different ribotypes were found after digestion with EcoRI, and 10 were found with HindIII. A combination of the two restriction endonucleases resulted in an increase in the discriminatory power (DP) from 14.3 to 31.6%. A combination of ribotyping with biotyping raised the DP to a maximum of 48.6%. The reproducibility of ribotyping was 100% after greater than 400 generations of growth. No correlation between methicillin resistance and certain ribotypes among the S. epidermidis strains was observed. Ribotyping is considered a useful tool for the intraspecific typing of CoNS for epidemiological purposes. The DP can be increased by the use of additional restriction endonucleases.

Nosocomial rotavirus infections in neonates: means of prevention and control.

Fifteen out of 24 risk neonates from the premature baby ward (= 63%) and 36 of 79 healthy neonates from the infant nursery (= 46%) at a Zürich hospital were infected within a period of 29 days during a nosocomial epidemic human rotavirus (HRV) outbreak. Forty-two out of 51 of all HRV-infected babies (=82%) manifested clinical symptoms, but these could not all be attributed to an HRV infection. On average, rotavirus could be detected in infected risk neonates five days after their admission to the premature baby ward. Eleven of the 15 risk neonates were infected within 10 days after the admission of the index case. Immediately after detection of the epidemic process, specific detailed countermeasures were instituted, including hand protection and hand disinfection, individual nursing set and cohorting of already infected babies. Early institution of such measures and information of all persons responsible for treatment and care of the babies concerned are crucial for success.

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.

Combination effect of piperacillin with four aminoglycosides on nonfermenting gram-negative bacteria.

The in vitro efficacy of piperacillin in combination with gentamicin, tobramycin, amikacin and netilmicin against 57 nonfermenting gram-negative bacterial strains was compared by use of the checkerboard agar dilution technique. On average 34% of all nonfermenting strains were inhibited by additive, 13% by synergistic piperacillin-amino-glycoside combinations. Great variation occurred between the different bacterial species. Piperacillin-aminoglycoside combinations were most active on Pseudomonas aeruginosa and least potent on Pseudomonas cepacia. Piperacillin was highly active against P. aeruginosa, P. cepacia, Pseudomonas fluorescens-putida and Acinetobacter species.

[Effectiveness of local and parenteral antibiotics in infection of aortic dacron grafts (author's transl)]. / Wirkung lokaler und parenteraler Antibiotika bei infizierten Gefässprothesen

The effectiveness of local and parenteral antibiotic prophylaxis in infections of aortic dacron grafts was tested in animal experiments. In 20 foxhounds Dacron-interpositions, 4 cms in length, were inoculated with 50 million Staph aureus bacteria and then treated in 4 different ways: Nr. 1-5 no antibiotic treatment. Nr. 6-10 local antibiotic (Nebacetin, R) treatment. Nr 11-15 parenteral treatment with Gramaxin (R) i.m. Nr. 16-20 combined Nebacetin (R) and Gramaxin (R) treatment. The untreated dogs developed infection of laparotomy wounds, peritoneum udn prosthesis. Nebacetin gave improved results, whereas Gramaxin led to complete eradication of the infection. It is concluded, that antibiotic prophylaxis should be applied in vascular surgery, whenever alloplastic, homologous or autologous implants are used.