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Query: UNIPROT:O75191 (H. influenzae)
 4,961 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The emergence of ampicillin-resistant strains of Haemophilus influenzae has emphasized the need for an improved practical method for routine susceptibility testing of clinical isolates. We have previously described a simplified medium for quantitative dilution susceptibility testing that is composed of Mueller-Hinton medium plus Supplement C (Difco). In the present study, paired broth-dilution and disk-diffusion susceptibility tests with ampicillin and chloramphenicol were performed on 100 strains of Haemophilus (95 H. influenzae and five H. parainfluenzae), including 30 strains with previously documented ampicillin resistance. Disk-diffusion tests were performed in exactly the same manner as the standardized Kirby-Bauer procedure used for less fastidious organisms, except that supplemented Mueller-Hinton agar plates were incubated in an increased-CO2 atmosphere. Using this method, ampicillin-susceptible strains of Haemophilus produced zone diameters of 22 mm or more, while ampicillin-resistant strains produced zones of 18 mm or less. All strains were chloramphenicol-susceptible and produced zone diameters of 30 mm or more. This method would allow routine disk-diffusion testing of isolates of H. influenzae by hospital diagnostic laboratories, using a clear medium that closely resembles unsupplemented Mueller-Hinton agar.
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PMID:Standardized disk-diffusion susceptibility test for Haemophilus influenzae. 30 Feb 21

In a previous study we observed that 6% of adult and 18% of children contacts of H. influenzae infected patients became carriers of the bacillus. We studied 1296 adults involved in children care, 398 from day care centers and 898 from hospitals in Santiago. A pharyngeal sample was cultured in chocolate agar plus bacitracin (300 mg/ml) and incubated at 37 degrees C in a 5-10% CO2 atmosphere for 18-24 h. Isolates of H influenzae were biotypified and serogrouped according to international recommendations. We observed that 2.4% of subjects were H influenzae carriers. Thirty carriers were treated with 2 doses of enoxacin, 440 mg. All became free of H influenzae at a 30-day follow-up.
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PMID:[Haemophilus influenzae carriers among child care personnel: its prevalence and the efficacy of enoxacin in its elimination]. 215 13

The in-vitro activity of a new macrolide antibiotic CP-62,993 (Pfizer Ltd) was determined for 420 bacterial isolates, comprising 150 Haemophilus influenzae, 48 Branhamella catarrhalis, 50 Staphylococcus aureus, 50 coagulase negative staphylococci, 50 beta-haemolytic streptococci, 50 Streptococcus pneumoniae and 22 oral streptococci. CP-62,993 was compared with erythromycin and penicillin (ampicillin in the case of H. influenzae). The MICs of CP-62,993 were found to be lower than those of erythromycin for the two Gram-negative species tested: this was particularly marked in the case of H. influenzae where a ten-fold difference in the MIC50 was observed (CP-62,993, 0.25 mg/l, erythromycin 2 mg/l). In general MICs of CP-62,993 were two-fold higher than those of erythromycin for the Gram-positive species studied, with the exception of the oral streptococci which were equally susceptible (MIC50 0.03 mg/l) to both macrolides. Activity similar to that of erythromycin was observed against Str. pneumoniae (MIC values 0.015-0.12 mg/l), Staph. aureus (MIC 0.12-1 mg/l) and beta-haemolytic streptococci (MIC 0.06-4 mg/l). Incubation in a CO2 enriched atmosphere decreased activity of both erythromycin and CP-62,993. The effect was more marked for CP-62,993, the MIC50s of all groups of organisms being increased four-fold when they were incubated in the presence of 5 or 10% CO2.
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PMID:The in-vitro activity of CP-62,993 against Haemophilus influenzae, Branhamella catarrhalis, staphylococci and streptococci. 283 51

There is poor correlation between the MICs and zone sizes obtained for erythromycin against Haemophilus influenzae. The effect of two media, Mueller-Hinton medium supplemented with 3% lysed horse blood and 10 micrograms of NAD per ml (MHA + LYHB) and Mueller-Hinton agar supplemented with 1% bovine hemoglobin and 1% IsoVitaleX (MHA + HGB), on the MICs and zone sizes of erythromycin against H. influenzae was determined. The effect of three different methods for inoculum preparation on the susceptibility of H. influenzae was also determined. The MICs were independent of the method of inoculum preparation, but the zone sizes were smaller if the inoculum was carefully adjusted to contain approximately 10(8) CFU/ml. MICs were higher and zone sizes were smaller when MHA + HGB was used instead of MHA + LYHB. Good correlation was found when MHA + LYHB was used for determining the MIC and MHA + HGB was used for determining susceptibility by the disk method. When the inoculum was adjusted to match a McFarland 0.5 standard, the viable counts had to be approximately 10(8) CFU/ml for good correlation between MICs and zone sizes. A-56268, a new macrolide antibiotic, was tested against H. influenzae, and its MICs and tentative breakpoints against this organism were determined. The MICs obtained by various methods were correlated with in vivo efficacy by using a mouse septicemia model. MICs obtained on MHA + HGB or MHA + LYHB incubated without a 5% CO2 atmosphere showed the best correlation with in vivo efficacy.
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PMID:Susceptibility testing of macrolide antibiotics against Haemophilus influenzae and correlation of in vitro results with in vivo efficacy in a mouse septicemia model. 295 54

Four separate laboratories performed antimicrobial susceptibility tests with 40 Haemophilus influenzae isolates, each tested in triplicate. Erythromycin and a new macrolide, clarithromycin (A-56268; TE-031), were tested by the disk diffusion method, by the agar dilution procedure in two different media, and by broth microdilution tests in four different media. Erythromycin MICs for 90% of the strains were 16 micrograms/ml in Mueller-Hinton broth with 3% lysed horse blood and NAD, 4.0 micrograms/ml in hemophilus test medium, and 2.0 micrograms/ml in supplemented Schaedler broth or in the fastidious broth medium from Beckman Instruments, Inc. Clarithromycin MICs were generally 1 doubling dilution greater than erythromycin MICs in each of the media. Erythromycin disk tests corresponded best with MICs determined in the fastidious broth medium. In that same medium, clarithromycin MICs were about 1 doubling dilution greater than what would be expected from the results of disk tests. Because there were fewer growth failures, hemophilus test medium is recommended for microdilution tests with H. influenzae. Incubation of all tests for a full 24 h without an increased CO2 atmosphere was needed to achieve maximal precision of the tests. Interlaboratory and intralaboratory reproducibility of all tests was satisfactory.
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PMID:Variability of clarithromycin and erythromycin susceptibility tests with Haemophilus influenzae in four different broth media and correlation with the standard disk diffusion test. 297 73

The in vitro activity of erythromycin against clinical isolates of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Streptococcus pyogenes and Haemophilus influenzae was examined by agar dilution and agar diffusion methods. The plates were incubated in air alone or in 8% CO2 and air. The minimal inhibitory concentrations (MICs) measured in air alone were lower for most of the isolates, compared to those found in 8% CO2. The greatest differences in MIC values were found for H. influenzae; the MIC 50% was 0.5 mg/l in air and 4 mg/l in 8% CO2. Sensitivity testing by the agar diffusion method (ICS) showed considerable differences between results obtained in air and in 8% CO2; the inhibition zones were generally smaller in CO2. The most marked reduction in zone sizes after incubation in 8% CO2 was seen with the H. influenzae isolates; 15 out of 43 isolates moved from the "sensitive" to "moderately sensitive" group. Sensitivity determination of aerobic bacteria for erythromycin should be performed in air alone in the routine laboratory.
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PMID:Effects of carbon dioxide upon the in vitro activity of erythromycin. 309 Aug 58

Morphology, biochemical reactions, pigmentation, antigens, and cell envelope proteins were examined in 12 strains of Haemophilus somnus, Haemophilus agni, Histophilus ovis, and Actinobacillus seminis. All of the strains except A. seminis are related and are considered as a single Haemophilus-Histophilus (HH) group. In immunodiffusion tests, HH group bacteria had at least two antigens common to all members of the group, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that they have similar cell envelope protein profiles. A quantitatively variable yellow pigment with absorption maxima of 430 to 435 nm was present in strains of H. somnus and H. agni. The HH group did not produce catalase and grew only in air containing 10% CO2. Of 10 HH group bacteria, 9 required thiamine monophosphate for growth. A. seminis was distinguished from the HH group by its lack of yellow pigment, production of catalase, growth in air, lack of a thiamine monophosphate requirement, and different cell envelope protein profile. In gel immunodiffusion tests, A. seminis antigens produced two lines of partial identity with the HH group when antiserum against H. somnus was used. Reference strains of Haemophilus influenzae, Actinobacillus lignieresii, and Haemophilus haemoglobinophilus were compared with the test strains. In immunodiffusion tests, a single antigen was found to be common to H. haemoglobinophilus, A. seminis, and the HH group. No similarities between any of the test strains and H. influenzae or A. lignieresii were noted. The close relationship of H. somnus, H. agni, and Histophilus ovis suggests that these unofficially named bacteria may belong to a single taxon.
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PMID:Morphological, biochemical, antigenic, and cytochemical relationships among Haemophilus somnus, Haemophilus agni, Haemophilus haemoglobinophilus, Histophilus ovis, and Actinobacillus seminis. 640 18

Representative antimicrobial drugs were examined under aerobic and hypercapnic (3 and 5% v/v CO2) incubation with the Bauer-Kirby agar disk diffusion, a broth microdilution method, and the agar dilution procedure against nonfastidious, standard ATCC quality control strains and against two beta-hemolytic streptococcal, two pneumococcal, and three Haemophilus influenzae ATCC strains. It was found that an atmosphere of 3-5% CO2 merely antagonized amikacin, gentamicin, and netilmicin; the activity of penicillin G was antagonized only against Staphylococcus aureus ATCC 29213 in broth media, but not against any of the other strains. The activity of teicoplanin, and less so that of vancomycin, was enhanced only against S. aureus strain ATCC 25923, but not against the other strains. It was concluded that susceptibility tests, excluding aminoglycoside antibiotics, of beta-hemolytic streptococci, pneumococci, and H. influenzae and H. parainfluenzae should be incubated under 3% (candle jar or incubator) or 5% CO2 (incubator) so as to ensure optimal growth of capnephilic strains and thus avoid potentially misleading large inhibition zones of deceptively low minimal inhibitory concentrations.
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PMID:Antibiotic susceptibility tests with fastidious and nonfastidious bacterial reference strains: effects of aerobic versus hypercapnic incubation. 787 18

The determination of the French breakpoints (< or = c, > C) were selected by the use of different criteria including bacteriological, pharmacokinetic and obviously clinical criteria. Concerning the bacteriological results, azithromycin, being an acid stable orally administered antimicrobial drug, is in vitro marginally less active than erythromycin against Gram-positive organisms including beta-haemolytic streptococci and Staphylococcus aureus. But in contrast, this azalide is more active than erytromycin against many Gram-negative pathogens, notably Neisseria gonorrhoeae, H. influenzae, Branhamella (Moraxella) catarrhalis, Ureaplasma urealyticum, and Borrelia burgdorferi. The activity of azithromycin is unaffected by the inoculum, unlike of pH, serum, and presence of CO2 for anaerobes. However, erythromycin-resistant micro-organisms are also resistant to azithromycin. Considering the pharmacokinetic criteria and the clinical results such as infections of the lower and upper respiratory tracts, skin and soft tissues, uncomplicated urethritis/cervicitis associated with N. gonorrhoeae, Chlamydia trachomatis or U. urealyticum, the preliminary breakpoints of azithromycin are defined by the following concentrations (< or = 0.12 and > 4 mg/l). Additional experimental and clinical results are required to confirm the in vitro activity against some other bacterial species (E. faecalis, L. monocytogenes, Brucella, P. multocida, or even Salmonella and Shigella).
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PMID:[Azithromycin: critical points]. 853 70

The in vitro activity of a novel 8-methoxyquinolone, BAY 12-8039, against recent clinical isolates of Streptococcus pneumoniae (n = 404), Haemophilus influenzae (n = 330), and Moraxella catarrhalis (n = 250) was evaluated. Activity was compared to those of six other fluoroquinolones: ciprofloxacin, clinafloxacin, levofloxacin, ofloxacin, sparfloxacin and trovafloxacin. BAY 12-8039 and clinafloxacin had the highest levels of activity against S. pneumoniae, both with a MIC at which 90% of the isolates were inhibited (MIC90) of 0.06 microg/ml. Trovafloxacin and sparfloxacin were the next most active agents versus S. pneumoniae (MIC90s = 0.12 microg/ml). No differences in activity against penicillin-susceptible, -intermediate, or -resistant strains of S. pneumoniae were noted for any of the fluoroquinolones tested. MIC90s for the seven fluoroquinolones ranged from 0.008 to 0.06 microg/ml versus H. influenzae and from 0.008 to 0.12 microg/ml for M. catarrhalis. The MICs for two strains of S. pneumoniae and one strain of H. influenzae were noted to be higher than those for the general population of organisms for all of the fluoroquinolones tested. Finally, the activity of BAY 12-8039 versus S. pneumoniae was found to be diminished when MIC determinations were performed with incubation of agar dilution plates or broth microdilution trays in 5 to 7% CO2 versus ambient air.
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PMID:In vitro activity of BAY 12-8039, a novel 8-methoxyquinolone, compared to activities of six fluoroquinolones against Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. 921 Jun 92


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