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M Altwegg

Publications and source records attributed to M Altwegg.

At least 109 records · Page 6Linked to original sources
PubMed1991

Multilocus enzyme analysis of the genus Aeromonas and its use for species identification.

A total of 153 Aeromonas strains were analyzed by multilocus enzyme electrophoresis. All 11 genetic loci were polymorphic with three to 14 alleles per locus (average 6.55). The genetic diversity of each locus varied between 0.095 for indophenol oxidase and 0.881 for the fast variety of malic enzyme. Cluster analysis of the 122 enzyme types revealed a good correlation with taxonomic groupings as determined by DNA-DNA hybridization. In conjunction with biochemical analysis, as few as two enzymes may be sufficient for the identification of all species in the genus Aeromonas.

Aeromonas↗
PubMed1991

Biochemical and genetic characterization of autoagglutinating phenotypes of Aeromonas species associated with invasive and noninvasive disease.

The genetic characteristics and biochemical and structural properties of a number of autoagglutinating (AA) strains of Aeromonas associated with invasive and noninvasive disease in humans and infections in animals and from environmental sources were investigated. Of 27 strains analyzed by multilocus enzyme typing and DNA hybridization studies, 25 (93%) were confirmed to belong to either hybridization group 1 (phenospecies and genospecies Aeromonas hydrophila) or 8 (phenospecies Aeromonas sobria; genospecies Aeromonas veronii). Further analysis of 19 of these strains indicated that four major groups could be identified on the basis of serologic and surface characteristics, protein and lipopolysaccharide composition, and virulence properties; these groupings held true regardless of the site of isolation or disease process involved. The major AA+ group identified was serogroup O:11, whose strains possessed an S layer, were resistant to the bactericidal activity of normal serum, and were pathogenic in mice. The results suggest a set of useful phenotypic and structural markers for identification of specific subsets of mesophilic Aeromonas involved in a wide range of infections in the animal kingdom.

Aeromonas↗
PubMed1990

[Salmonella gastroenteritis: causes, sequelae, therapeutic perspectives].

Enteric salmonella are the most frequently isolated pathogens of bacterial diarrhea in Switzerland. Since 1987, increasing numbers have been reported to the Federal Health Office. The causes of this rise in salmonellosis prevalence, which has been observed in a number of countries, are the high rates of contamination in different foods, mainly in poultry and eggs. It has been shown that the usual kinds of egg preparation are not suitable for the elimination of salmonella, which may also be found inside the egg-shells. The solution to this problem involves measures of veterinary epidemiology and food hygiene. The epidemiologic significance of the asymptomatic carrier is considered to be rather slight. However, prolonged excretion of salmonella repeatedly results in social and economic problems, because the carrier food handlers are excluded from work when and for as long as they are excreting salmonella. Current possibilities in antibiotic treatment for these and other salmonellosis patients are discussed.

Carrier State↗
PubMed1990

In vitro activities of fleroxacin, cefetamet, ciprofloxacin, ceftriaxone, trimethoprim-sulfamethoxazole, and amoxicillin-clavulanic acid against rare members of the family Enterobacteriaceae primarily of human (clinical) origin.

Fleroxacin and cefetamet were evaluated in vitro against 38 infrequently encountered species (250 strains) of the family Enterobacteriaceae and compared with four established compounds. For all the strains tested, the fleroxacin MIC was less than or equal to 0.5 mg/liter, and for 98% of strains the cefetamet MIC was less than or equal to 8 mg/liter; even though the two new compounds did not quite reach the activities (on a weight-by-weight basis) of ciprofloxacin and ceftriaxone, respectively, they nonetheless clearly surpassed trimethoprim-sulfamethaxazole and amoxicillin-clavulanic acid. The very potent new oral compounds tested in this study appear to be promising for the treatment of clinically relevant infections due to uncommon species of Enterobacteriaceae.

Amoxicillin↗
PubMed1990

Biochemical identification of Aeromonas genospecies isolated from humans.

One hundred phenotypic characteristics were determined for 138 clinical and environmental Aeromonas strains. Cluster analysis revealed three major phenons equivalent to the A. hydrophila, A. caviae, and A. sobria groups, each of which contained more than one genospecies and more than one named species. An excellent correlation was found between phenotypic identification and classification based on DNA relatedness. DNA hybridization groups within each of the phenotypic groups were also separable by using a few biochemical characteristics. Key tests were production of acid from or growth on D-sorbitol (which separated DNA hybridization group 3 from groups 1 and 2 within the A. hydrophila phenogroup), growth on citrate (which essentially separated DNA hybridization group 4 from groups 5A and 5B within the A. caviae phenogroup), and growth on DL-lactate (which separated DNA hybridization group 1 from groups 2 and 3 within the A. hydrophila phenogroup as well as group 5A from groups 4 and 5B within the A. caviae phenogroup). All except one strain in the A. sobria phenogroup belonged to DNA hybridization group 8. DNA hybridization groups were not equally distributed among clinical and environmental isolates, suggesting that strains of certain DNA hybridization groups might be less virulent than others.

Aeromonas↗
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

Ribosomal RNA gene restriction patterns provide increased sensitivity for typing Salmonella typhi strains.

To date, epidemiologic associations among strains of Salmonella typhi are based exclusively on phage typing, which may be of limited value if a common phage type is involved. Analysis of ribosomal RNA gene restriction patterns allows separation of most independently isolated strains of identical phage types. The sensitivity of the method is dependent on the restriction enzymes used to digest chromosomal DNA. It was highest for PstI, which separated 16 of 20 strains that belonged to 8 phage types including 3 untypable strains. Three strains differed in their phage types but had identical ribosomal RNA gene restriction patterns. Also, two pairs of strains indistinguishable by phage typing exhibited identical patterns; however, two of these strains were expected to be identical because they were isolated from two patients who were likely exposed to the same source. Ribosomal RNA gene restriction patterns appear to be stable. Thus, the method may complement phage typing and aid in further differentiation of strains.

Bacteriophage Typing↗
PubMed1989

CDC group HB-5 as a cause of genitourinary infections in adults.

Isolates from five patients with genitourinary infections diagnosed over a 7-week period were identified as CDC group HB-5. The organisms caused clinical presentations of pelvic inflammatory disease in three women and urethritis in the only male in the series. The remaining patient received surgical treatment for a Bartholin gland abscess. Since the clinical and temporal presentations were remarkable and the questions of sexual mode of transmission and strain relatedness were of concern, the five strains were examined further by multilocus enzyme electrophoresis and ribosomal DNA typing. Overall, the five clinical isolates were more closely related to each other than to the control strains. This is the first report describing genitourinary infections caused by group HB-5. While the pathophysiology of group HB-5 infections remains to be fully elucidated, the possibility that this organism may be sexually transmitted deserves further study.

Abscess↗
PubMed1989

Aeromonas as a human pathogen.

Although the first Aeromonas strain was described by Zimmermann as early as in 1890, it took 60 years until Caselitz established human pathogenicity of strains then called "Vibrio jamaicensis". Since then, and especially in the last 10 years, there have been increasing numbers of reports on different infections caused by members of the genus Aeromonas. These include sepsis; meningitis; cellulitis; necrotizing fasciitis; ecthyma gangrenosum; pneumonia; peritonitis; conjunctivitis; corneal ulcer; endophthalmitis; osteomyelitis; suppurative arthritis; myositis; subphrenic abscess; liver abscess; cholecystitis and/or ascending cholangitis; urinary tract infection; endocarditis; ear, nose, and throat infections; balanitis; etc. The role of Aeromonas in gastrointestinal disease is very controversial. Increasing epidemiological data suggest that these organisms play a major role in enteric infections, but so far enteropathogenicity has not been demonstrable in experiments where volunteers were given high numbers of Aeromonas possessing different virulence factors. Virulence factors include hemolysin(s), enterotoxin(s), hemagglutinins, invasivity, and others; but these are not found more frequently in strains isolated from patients with diarrhea than from healthy controls. Whether there is a correlation between species and disease remains to be elucidated and requires more information about the taxonomy of this genus.

Aeromonas↗
PubMed1988

Multilocus enzyme electrophoresis of Clostridium argentinense (Clostridium botulinum toxin type G) and phenotypically similar asaccharolytic clostridia.

Twenty-three strains of Clostridium argentinense, C. subterminale, C. hastiforme, and other phenotypically similar asaccharolytic clostridia recently placed in seven DNA hybridization groups were compared by multilocus enzyme electrophoresis. The three nontoxigenic strains of C. argentinense were most closely related to the toxigenic strains of this species. All nine toxigenic strains of C. argentinense belonging to a single DNA hybridization group had identical enzyme types on the basis of nine enzymes. All other strains except for two derived from the type strain of C. subterminale were differentiable. Overall, there was excellent agreement between DNA relatedness and multilocus enzyme electrophoresis results.

Clostridium↗
PubMed1987

Isolation frequency of Aeromonas species in relation to patient age.

Over a period of 18 months Aeromonas spp. were isolated from stool specimens of 116 patients (total isolation frequency 1.6%). Isolation rates in children up to ten years of age were significantly higher only for Aeromonas caviae as compared to other age groups. Additional data are needed to assess the clinical significance to these findings.

Adolescent↗
PubMed1987

Evaluation of a small "conventional" identification system for fermentative gramnegative rods using a computerized data base.

A small "conventional" identification system consisting of six tubed media totalling eleven reactions was used to identify 467 strains of Enterobacteriaceae, 15 strains of Aeromonas sp., and 3 strains of Plesiomonas shigelloides. The system identified 371 strains (76.5%) correctly to maximum identification (species or genus) level and an additional 13 strains (2.7%) to genus level where species level identification would have been possible. Ninety strains (18.6%) were not identified. Only 11 strains (2.3%) were misidentified. The system is inexpensive compared with commercial systems and can be used for primary identification of fermentative gramnegative bacteria in a clinical microbiology laboratory. It comes with a computerized data base in the form of an identification manual.

Aeromonas↗
PubMed1987

Problems in identification of Campylobacter jejuni associated with acquisition of resistance to nalidixic acid.

In a patient with campylobacteriosis, we observed development of resistance to nalidixic acid and norfloxacin under adequate treatment with the latter antibiotic. Isolates before and after treatment differed in their total protein profile but were otherwise identical with respect to enzymatic activity, serotype, crude membrane protein profiles, and other phenotypic characteristics.

Adult↗
PubMed1987

[Aeromonas spp. as pathogens in human infections: diagnosis and clinical significance].

Aeromonads have been described as causative agents in a wide variety of infections in immunosuppressed as well as in immunocompetent patients. It is still controversial whether or not some or all three currently recognized species have to be considered as enteropathogenic. Clinical and epidemiological data are incomplete and contradictory although laboratory diagnosis does not cause real problems.

Aeromonas↗
PubMed1986

[Resistance patterns in Shigella].

Diarrhea is the most common health problem in travelers to tropical countries. Shigellae are not the primary cause but often provoke clinically relevant diseases that call for treatment. Therefore, we have analyzed resistance patterns in all Shigella strains isolated at this department over 1 1/2 years. Of 107 isolates 77% were resistant to tetracycline, 33% to trimethoprim-sulfamethoxazole, 31% to ampicillin, and only 2% to nalidixic acid. Differences in resistance patterns for isolates of different geographical origins were marginal. The small number of strains resistant to nalidixic acid (2/107) suggests that agents inhibiting DNA gyrase may be useful for self-administered treatment during travel as well as upon return. Controlled clinical trials, however, are still lacking.

Anti-Bacterial Agents↗
PubMed1986

[Enteropathogens in travellers returning from the tropics].

Diarrhea is not only the most common health hazard during travel in the tropics but also the most frequent condition which prompts returning travellers to see a physician. The prevalence of bacterial and parasitic enteropathogens in people attending our outpatient department after returning from the tropics has been studied and the laboratory results of stool examinations have been compared with clinical symptoms. Of the 173 persons enrolled, 19 (11%) harboured bacterial pathogens and pathogenic protozoans (Giardia lamblia and Entamoeba histolytica) were found in 26 (15%). The data of 156 patients were evaluated. Enteropathogenic bacteria and/or protozoa were found in 29 (46%) of the 63 patients presenting with diarrhea at the time of investigation. In contrast, 10 (11%) of the 93 asymptomatic subjects had enteropathogenic organisms in the feces (p less than 0.01). The results appear to confirm that bacteriological stool examinations of travellers returning from the tropics without diarrhea are not usually indicated, even if a history of transient travellers' diarrhea is reported. Parasitological investigations are justified in this group only if asymptomatic carriage of Giardia or E. histolytica is considered an indication for specific treatment.

Aeromonas↗