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H Mittermayer

Publications and source records attributed to H Mittermayer.

At least 37 records · Page 2Linked to original sources

Distribution and resistance patterns of Haemophilus influenzae: a European cooperative study.

The first European survey of the prevalence of antibiotic resistance in Haemophilus influenzae was conducted between February and October 1986. Eighty laboratories in nine countries participated (Austria, Belgium, France, FRG, The Netherlands, Spain, Sweden, Switzerland and the UK). A total of 1,961 clinical isolates was examined for type b encapsulation, beta-lactamase production and susceptibility to ampicillin, chloramphenicol, cefaclor, erythromycin and tetracycline, using a unique microdilution method. The proportion of isolates resistant to these antibiotics varied considerably between individual countries. The highest prevalence of ampicillin resistance was found in Spain (30.6%), and the lowest in the FRG (1.6%), with a mean value of 10% for all countries. Chloramphenicol resistance was highest in Spain (24.9%) and Belgium (10.9%) and lowest in The Netherlands (0.6%) and Austria (0.5%), with a mean value of 4.7%. Resistance to erythromycin ranged from 27% of the isolates in The Netherlands to 1.1% in Austria. For tetracycline, values ranged from 1.5% in the UK to 17.8% in Belgium and 25.4% in Spain. The lowest mean prevalence of resistance was observed for cefaclor (breakpoint 8 mg/l): 5% or less in all countries. These inter-country differences could only partially be explained by variations in the proportion of type b strains, the source of the isolates and the mode of collection.

Ampicillin Resistance↗

[Campylobacter pylori colonization of the antrum mucosa in patients with chronic gastritis and peptic ulcer].

Campylobacter pylori, a bacterium specifically adapted to the environment of gastric mucous is closely associated with peptic gastric diseases. It is detected within the mucus and in relationship to the intercellular spaces in cases of active chronic gastritis. Approximately 70% of patients with chronic type-B-gastritis are infected with C. pylori. In type A or reflux gastritis C. pylori is hardly seen. A causal relationship seems likely. More than 80% of patients with duodenal ulcer and round half of the cases with gastric ulcer show C. pylori in the gastric mucosa. The pathomechanism, how C. pylori facilitates the development of peptic ulcer is since hypothetical. It is discussed that the bacterium leads to a local breakdown of gastric mucosal defence.

Campylobacter↗

[Microbiologic findings in nephrology].

Infections of the urinary tract belong to the most frequently encountered bacterial diseases of man. Up to 20% of urinary tract infections take a chronic course and thus give rise for complications. Culture and identification of microorganisms as well as susceptibility testing are an essential part of the diagnostic procedures and give a basis for specific treatment. Bacteriological reports have an increasing importance also for the physician in private practice, since therapy failures and complications can only be avoided if the resistance patterns of the causative organisms are known. Appropriate collection and transport of specimens are an important prerequisite for clinically relevant reports. In most cases properly collected mid-stream urine is sufficient for microbiology. Catheterization and other collection methods are less frequently applied. The urine sample should reach the laboratory as fast as possible and should be stored refrigerated until processing. As an alternative dip-slide cultures can also be used. Dip-slides, however, yield much less information than urine specimens. Bacterial counts of 10(5)/ml or greater are usually considered as significant bacteriuria. Under certain conditions lower counts can be clinically relevant. The most frequent causes of urinary tract infections are still Escherichia coli and other enterobacteriaceae. Hemodialysis patients and kidney transplant recipients are highly infection-prone. In hemodialysis infections of the vascular shunt are frequently seen. These infections are mainly caused by Staphylococcus aureus. About one third of all complications after kidney transplantation are related infectious conditions. Thus early detection and surveillance of infections to preserve the transplant function are a great concern for clinical microbiology.

Bacteria↗

[Susceptibility of the Bacteroides fragilis group to 10 antibiotics. Results of 4 laboratories in Austria].

The susceptibility of 197 strains of the Bacteroides fragilis group (109 B. fragilis, 27 B. thetaiotamicron, 23 B. vulgatus, 1 B. distasonis, 11 B. ovatus and others) to penicillin G, cefoxitin, latamoxef, piperacillin, mezlocillin, clindamycin, metronidazole, tetracycline, doxycycline and chloramphenicol was tested by an agar dilution method. 4 microbiological laboratories in Austria participated in this investigation. In all laboratories the same method was used and a joint quality control carried out. The most active substances were metronidazole and clindamycin (MIC50 1.0 and 0.5 respectively; MIC90 4 mg/l for both). Tetracycline showed only little activity, whereas doxycycline inhibited a major portion of the strains at therapeutically relevant concentrations (MIC50 16 and 2 mg/l, MIC90 32 and 16 mg/l, respectively). The MIC90 of chloramphenicol was 8 mg/l. Piperacillin and mezlocillin were about equally active (MIC50 both 16, MIC90 32 and 64 mg/l, respectively). For penicillin G, the MIC values were also favourable, the MIC90 being 32 mg/l. The possible causes for the discrepancy between the good in vitro activity and the clinical ineffectiveness of penicillin G are discussed. The cumulative MIC values (50, 90%) for cefoxitin were 8 and 32 mg/l, respectively. The MIC's of latamoxef showed a wide distribution resulting in a low MIC50 (4 mg/l) and a high MIC90 (128 mg/l). This distribution was due to the differing susceptibility of the individual species within the Bacteroides fragilis group. For B. thetaiotaomicron the highest MIC values were determined. This species as a whole was less susceptible to the beta-lactam antibiotics tested. The non beta-lactam antibiotics showed no substantial species related differences. No relevant differences between the individual laboratories were observed.

Anti-Bacterial Agents↗

[Resistance of blood culture isolates in vitro to 4 aminoglycoside antibiotics in Austria--1982/83].

Over the period September 1982 to February 1983 268 blood culture isolates were consecutively collected in 4 microbiological laboratories in Austria (Linz, Vienna, Graz, Feldkirch) and 251 of these strains (streptococci excluded) were tested for resistance to Gentamicin (G), Tobramycin (T), Netilmicin (N) and Amikacin (A) using a microtitre broth dilution method. This investigation was part of an international study. Of the bacterial strains examined 57% were staphylococci (34% Staphylococcus aureus) and 43% gram-negative rods (18% E. coli, 17% other enterobacteriaceae and 5% Pseudomonas aeruginosa etc.). 25% of all strains tested were resistant to Gentamicin (MIC greater than 4 mg/l), 27% to Tobramycin (MIC greater than 4 mg/l), 6% to Netilmicin (MIC greater than 4 mg/ml) and 5% to Amikacin (MIC greater than 8 mg/l). The resistance rate of staphylococci was markedly greater towards Gentamicin (35%) and Tobramycin (39%) than Netilmicin (4%) and Amikacin (6%). The respective percentages of resistant gram-negative rods were considerably smaller, except in the case of Netilmicin (G 13%, T 11%, N 8%, A 4%). Regional differences were observed between Linz and Vienna in the resistance of staphylococci to Gentamicin (24% versus 49%) and Tobramycin (33% versus 53%). On a weight basis Netilmicin was the most active substance in combating nearly all groups of bacteria. Also in strains sensitive to the other aminoglycosides the MIC values of Netilmicin were considerably lower than for the other substances. A noteworthy feature in comparison with the results of other countries participating in this international study was the distinctly higher incidence of staphylococci among the blood culture isolates and the considerably higher percentage of aminoglycoside-resistant strains in Austria. Analysis of the data suggests that the high resistance rates among staphylococci are a consequence of selection by frequently used antibiotics. Hence, it appears essential to observe the development of aminoglycoside resistance in Austria closely and to recommend that these substances, of extreme value in the treatment of severe infections, should be used solely for the most stringent indications.

Aminoglycosides↗

Augmentin in acute exacerbations of chronic bronchitis.

Forty-five patients with acute chronic bronchitis were treated with Augmentin, an amoxycillin combined with the beta-lactamase inhibitor clavulanic acid, initially by parenteral administration followed by oral treatment after 3 days lasting in the mean 7.1 days. The over-all clinical evaluation showed a cure rate of 93%. Side-effects were comparable to therapy with other amoxycillins. Bacteriological evaluation of the sputum samples demonstrated in 91% of cases an elimination of the initially isolated organism. Prior to therapy we found in 25% of the isolated strains beta-lactamase-producing and Augmentin-sensitive organisms. The parenteral formulation of Augmentin seems to be a valuable addition to the parenteral therapy of lower respiratory tract infections.

Acute Disease↗

Single dose cefuroxime/metronidazole versus metronidazole alone in elective colorectal surgery.

Sixty assessable patients undergoing elective colonic and rectal surgery were randomly allocated to receive prophylaxis with a combination of 1.5 g cefuroxime plus 500 mg metronidazole or 500 mg metronidazole alone as single doses by the intravenous route, given at the beginning of anesthesia. The two groups were matched for age, sex, malignancy, and type of operation. Primary wound infections were observed in one patient (3.7%) in the combination group and six (18.2%) in the group given metronidazole alone. This trend was not statistically significant. Bacteriologic examination of the anastomoses, abdominal walls, and wounds showed significantly more sterile cultures in the combination group, although more aerobic cefuroxime-resistant isolates were seen in this group. There is no evidence that the emergence of resistant strains had any influence on the outcome of patients in the study. It was concluded that an appropriate antibiotic prophylactic regimen for colorectal surgery should be directed against aerobic and anaerobic organisms. Cefuroxime plus metronidazole is an effective regimen for the prevention of postoperative infection.

Adult↗

[Anaerobic bacteria in clinical specimens of a hospital laboratory (author's transl)].

Over a 14-month period 261 clinical specimens were cultured anaerobically, this figure representing about 3% of the total specimens submitted to the microbiological laboratory. Not accepted for anaerobic culture were stools, sputa, urines, vaginal and urethral swabs and swabs from superficial skin lesions. All materials were sent to the laboratory in an anaerobic transport medium and processed according to the recommendations of the American Society for Microbiology and the Center for Disease Control, Atlanta, Georgia. Not included in this figure are blood cultures and cultures from removed venous catheters. 35% of the specimens contained anaerobes. 169 anaerobic strains were isolated. 78 of them belonged to the Bacteroides fragilis group. Clostridium perfringens was found in only 7 cases. 14% of the strains were B. melaninogenicus, 7% other gram-negative non-sporeforming rods. In most of the cases a mixed aerobic-anaerobic flora was found. More than 75% of specimens obtained from infections originating from the lower intestinal tract yielded growth of anaerobes. In infections of the bile duct anaerobes were found in 25% of the cases. In infections of the upper urinary tract anaerobes played no major role. 35% of the isolates of the B. fragilis group were resistant to tetracycline, 17% to cefoxitin and 9% to clindamycin.

Abscess↗

[Testmethod for the evaluation of procedures for the hygienic disinfection of hands. Part 1: Discription of testmethod (author's transl)].

A detailed test design for the evaluation of procedures for the hygienic disinfection of hands is described together with suitable methods for statistical analysis of the results. In principle the release of testbacteria from the finger-tips of artificially contaminated hands is measured before and after disinfection. A procedure under test is accepted if it is not less effective than a standard-disinfection procedure. As such the disinfection with iso-propanol 60% (ml/ml) applied through 1 min was agreed upon. This standard procedure is to be performed the same day with the same day with the same testpersons and under identical environmental conditions prior to the procedure under test.

1-Propanol↗

[Further experimental investigations on the therapy of gas gangrene with ozone and oxygen (author's transl)].

In continuation of a recently-published investigation on the effect of intramuscular injections of an ozone-oxygen mixture on experimental gas gangrene in the guinea pig, 2 additional experiments were performed in order to establish the efficacy of the therapy when given twice daily instead of only once. Futhermore, the effect of an analogous therapy was investigated with the use of pure oxygen. The ozone-oxygen therapy reduced the death rate from 100% in untreated control animals to 73.6 and 70.0%, respectively, in the 2 series of experiments. The median survival times were prolonged from 0.56 and 1.33 days to 5.50 and 6.66 days. The use of oxygen twice daily reduced the death rates significantly even further to 57.0 and 47.9%. With this therapy the median survival time was increased to 8 and more than 12 days. The differences in therapeutic effect of the 2 gases were not, however, statistically significant. On account of its simple applicability previous experiments on animals it is proposed that this therapy be employed also in cases of human gas gangrene. In addition, the bactericidal effect of CaCl2, as used in this experimental study, on vegetative forms of Clostridia is demonstrated.

Animals↗

Staphylococcal toxic epidermal necrolysis: species and tissue susceptibility and resistance.

The staphylococcal exfoliatin, which is responsible for the "scalded skin syndrome" in man, cleaves the epidermis directly beneath the stratum granulosum. Its activity in vivo is paralleled in organ cultures, providing a rapid and convenient assay. The cutaneous responses of several mammalian and nonmammalian species were examined both in vivo and in vitro. Human and murine skin, as well as that of hamsters and monkeys exfoliated, while all other species tested (rat, rabbit, guinea pig, dog, frog, and chicken) were refractory. Results were identical in vivo and in vitro. Susceptibility and resistance are inherent, presumably genetic, attributes of the epidermis, since neither dermal elements nor circulating factors interfered with or influenced sensitivity to staphylococcal exfoliatin. Besides possessing species specificity, this exfoliatin is also tissue specific, failing to cleave all mouse nonkeratinizing epithelia tested, while the reactions of some extracutaneous keratinizing epithelia were equivocal. The species and tissue specificity of the staphylococcal scalded-skin syndrome may be attributable to either keratinocyte receptors specific for exfoliatin or the presence of specific, as yet undefined, substances in the intercellular space.

Animals↗

[Kinetics of the release of testbacteria from the artificially contaminated hand (author's transl)].

It is demonstrated that the release of testbacteria from the finger tips of artificially contaminated hands is influenced to a very small degree only by application of the finger tip method when compared to the effect of ablutions. Therefore, without apprehension of influencing the post-values this method may be employed in order to assess pre-values as required by the test-model of Rotter and Mittermayer (5) for the evaluation of procedures for the hygienic disinfection of hands. In addition, it can be shown directly that it is irrelevant for the number of bacteria released after a germ-reducing procedure, whether the finger tip-method has been used or not, preceedingly. In contrast, all technical variations that aim at the restitution of the supposed loss of testbacteria (like renewed contamination after the assessment of prevalues) change the postvalues measurably and must be avoided, therefore. Drying of bacterial suspensions on the hands, as after artificial contamination, reduces the release of viable testbacteria depending on the time. This effect is stronger on the palms than on the finger tips. The influence of handbrushes on the release of testbacteria with simultaneous useage of detergents compares well with the effect of an alcohol disinfection. However, this method is not suitable to eliminate pathogens safely.

Escherichia coli↗

[Comparative investigations on the efficacy of tap water, some detergents and ethanol on the transient flora of the hands (author's transl)].

The germ reducing efficacy of tap water, soap, pHisoHex, pHisoDerm and 70% ethanol was compared using the model of hands artificially contaminated with E. coli. Each of ten persons washed 1, 2 or 4 minutes. Reduction factors were calculated from pre- and post-values and were compared for each individual. After one minute the logarithms of the geometric means of the reduction factors amounted to 2,99, 3,23, 3,28, 3,61, 4,25 in the above used sequence (Table 2). After one minute the reductions came off more slowly and the slopes were linear and parallel as far as the mechanical germ reducing procedures are concerned (Fig. 2). In contrast, ethanol caused a steeper slope even after one minute wash. The strong reduction achieved by mechanical procedures (even with water for one minute 3 powers of ten were observed) demonstrates the high hygienic importance of hand washings for removal of the transient flora. Detergents like pHisoDerm produce further significantly higher reductions and seem to be more suitable than aggressive disinfectants for application in fields where bactericidal action is not imperative. The proposals for procedures aiming at disinfecting of the transient flora issued by the Austrian Society for Hygiene, Microbiology and Preventive Medicine require a reduction factor of at least 10(5) after two minutes hand wash. The results of this investigation show that this is practicable with ethanol and necessary, otherwise the bactericidal action would not be different from a mechanical removal of the transient flora.

Austria↗

[Comparative investigation on recovering bacteria from the artificially contaminated hand (author's tranls)].

A modification of the basin-procedure (PRICE), the plastic-bag-(GASCHEN), the fingertip-(SCHUMBURG) and the glass-cup-method (STORY) were compared in order to evaluate their efficiency to recover bacteria from the artificially contaminated hand. With all 4 methods there was a linear relation between the bacterial content of the contamination and the rinsing fluid in which the germs were collected from the hands (FIG. 1, Tab. 9). The number of recovered bacteria per ml, however, differed greatly with the method used. Without regard to the volumes of rinsing fluid and the size of the offered skin area, both differing with the metheod, the finger-tip-procedure yieleded the highest counts followed by the plastic-bag-, basin- and glass-cup-method (Fig. 1). Compensating the influence of the volume the three procedures first mentioned appeared equally effective (Fig. 2 and Tab. 11). It, however, has to be noticed that the finger-tip-method uses a skin area considerably smaller than the other two methods. The glass-cup-method was the least effective but used on the palm the recovery was still 10 times that of the yield of the back (Fig. 2). Because of its high efficacy, the better exploitation of the subungual spaces and because of its simplicity, the finger-tip-method seems to be the procedure best suited for recovering bacteria from the artificially contaminated hand.

Bacteria↗

[Thoughts upon the construction of requirements of disinfection procedures concerning contaminated hands - an analysis (author's transl)].

The construction of detailed test methods for the evaluation of disinfection procedures has primarily to be based upon requirements which have to be formulated in advance. A recently proposed test model is being discussed on the basis of 5 conceivable formulations of possible requirements. Essentially, they may be allotted to two types: the one implies the comparison of the disinfection procedure to be tested as against an hypothetical procedure. The other makes use of the simple comparison with a concrete standard procedure and is preferable to the first possibility for several reasons. The presented, mathematical formulations of the structure describing the proposed model represents a first approximation in order to permit the comparison of disinfection effects on the hands under assistance of probabilistic methods and eliminating other effects inherent ot a test method.

Disinfection↗