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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intraperitoneal injections of 250 mg of ampicillin per kg every 6 h for 30 h sterilized the blood and cerebrospinal fluid of infant rats infected with either a beta-lactamase-containing strain of Haemophilus influenzae type b or a strain lacking the enzyme. However, a single injection of 100 mg/kg sterilized the blood and cerebrospinal fluid of significantly fewer of those rats infected with the beta-lactamase-producing strain. The results suggest that resistance of beta-lactamase-containing strains of H. influenzae in vivo may be inoculum dependent, as demonstrated previously in vitro. The infant rat model appears suited for the quantitative delineation of the effect of beta-lactamase on the treatment of H. influenzae bacteremia and meningitis with beta-lactamase antibiotics.
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PMID:Beta-lactamase effect on ampicillin treatment of Haemophilus influenzae B bacteremia and meningitis in infant rats. 30 97

We investigated the following six Haemophilus species from man for the both enzymes neuraminidase and N-acetylneuraminate pyruvate lyase: H. aegypticus, H. aphrophilus, H. influenzae. H. parahaemolyticus, H. parainfluenzae and H. vaginalis. It is shown that H. vaginalis does not produce either neuraminidase or N-acetylneuraminate pyruvate lyase. He differs, therefore, from all other investigated haemophili producing both enzymes, neuraminidase and N-acetylneuraminate pyruvate lyase. Colominic acid, Na-salt, is splitted better than N-acetylneuraminyllactose. It can be concluded, therefore, some substrate specificity of the neuramindase of Haemophili in the sense that the alpha, 2 leads to 8 linkage of neuraminic acid is cleaved quicker than the alpha, 2 leads to 3 linkage. The physiological and pathologenic role of the both enzymes is discussed.
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PMID:[The occurrence of neuraminidase and N-acetylneuraminate-pyruvate lyase in pathogenic haemophili of man (author's transl)]. 30 52

The application of counter current immunoelectrophoresis to the detection of Haemophilus influenzae capsular antigen in sputum is described. The method, technically simple, provided results within 30 minutes. H. influenzae capsular antigen was detected in 12% of patients and in 54.8% of the H. influenzae strains isolated. The test was not impaired by prior antibiotic therapy.
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PMID:Detection of capsulated Haemophilus influenzae in chest infections by counter current immunoelectrophoresis. 30 61

Synergy, determined by isobolograms constructed from the minimal inhibitory concentrations of combinations of ampicillin and chloramphenicol, was observed against six of 13 ampicillin-susceptible Haemophilus influenzae type b isolates and against five of eight ampicillin-resistant strains by using a small inoculum of 10(4) colony forming units (CFU) per milliliter. Synergy occurred against nine of 13 ampicillin-susceptible and against two of eight ampicillin-resistant strains using a large inoculum of 10(7) CFU/ml. When synergy was not observed, additive effects occurred against the remainder of isolates. Additive effects were also observed against single strains of chloramphenicol-resistant, nontypeable H. influenzae and H. parainfluenzae. No antagonism was observed. These data indicate that ampicillin and chloramphenicol may be synergistic against a significant number of H. influenzae strains depending on inoculum size, but the effect is unpredictable for a given isolate. These data support the recommendation that ampicillin and chloramphenicol both be used as initial therapy for patients with suspected bacterial meningitis.
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PMID:Effect of ampicillin and chloramphenicol against Haemophilus influenzae. 30 90

The need for an accurate and rapid method of testing ampicillin susceptibility of Haemophilus influenzae, especially strains isolated from patients with meningitis and septicemia, is indisputable. Various methods have been employed for this purpose. Each has advantages and disadvantages. This report describes a modification of the capillary acidometric procedure in which an agar plate is substituted for a tube. All beta-lactamase results obtained by this modified technique correlated with minimal inhibitory concentrations determined in liquid media and the chromogenic cephalosporin substrate method. This modified acidometric agar procedure is a simple, inexpensive, accurate, and rapid way to determine H. influenzae susceptibility to ampicillin.
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PMID:Acidometric agar plate method for ampicillin susceptibility testing of Haemophilus influenzae. 30 20

Fifty-three infants and children, aged three months to 15 years, were treated with an average daily dose of 100 mg of cefamandole/kg intravenously. Of these patients, 47 had soft tissue cellulitis and six had pneumonia. Primary pathogens, including Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, and Haemophilus influenzae, were isolated from 43 of the 53 patients. Bacteremia was documented in six of the 53 patients. A satisfactory clinical and bacteriologic response to cefamandole was achieved in all cases except on (98%). The only treatment failure occurred in an infant with both periorbital cellulitis and bacteremia due to H. influenzae who developed meningitis while receiving cefamandole; no extravasation of the drug across the blood-brain barrier could be detected in spite of inflamed meninges. In general, the only aberrant effects of cefamandole were the appearance of eosinophilia in 28% of patients and a positive indirect Cooms' test without hemolysis in one patient. Cefamandole showed excellent in vitro activity against 87 ampicillin-resistant strains of H. influenzae. Because it has greater activity than any of the other cephalosporins against this important pediatric pathogen, cefamandole may have particular pertinence in the treatment of infections in infants and young children.
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PMID:Clinical and laboratory evaluation of cefamandole in infants and children. 30 2

The in vitro activity of cefamandole was determined against 58 isolates of Haemophilus influenzae type b; 47 were beta-lactamase-negative (ampicillin-susceptible), and 11 produced beta-lactamase (ampicillin-resistant). Ampicillin-susceptible strains were susceptible to cefamandole with a median minimal bactericidal concentration (MBC) of 0.4 microgram/ml. Ampicillin-resistant strains had a median MBC of 0.8 microgram/ml. Prior studies have documented these concentrations of cefamandole in cerebrospinal fluid in the presence of inflamed meninges. Three children with meningitis due to H. influenzae type b were treated with cefamandole (200 mg/kg per day), including one child with disease due to an ampicillin-resistant strain. All patients showed clinical improvement during therapy. However, sterility of the cerebrospinal fluid was never achieved in two patients during 72--96 hr of therapy with cefamandole. The third patient relapsed with a recurrence of positive cultures during the seventh day of cefamandole therapy. Therefore, cefamandole does not appear to be a useful agent for treatment of meningitis due to H. influenzae type b irrespective of in vitro susceptibility or evidence of penetration into the cerebrospinal fluid.
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PMID:Failure of cefamandole in treatment of meningitis due to Haemophilus influenzae type b. 30 3

Infant rats were infected intranasally with mixtures of streptomycin-sensitive and streptomycin-resistant strains of Haemophilus influenzae type b and cultures of nasopharyngeal washings, blood, and cerebrospinal fluid were obtained. If the infecting organisms cooperated with each other during the establishment of infection, nasopharyngeal, blood, and cerebrospinal fluid cultures should have contained mixtures of the variants. If each organism acted independently, then with small infecting inocula all the organisms in nasopharynx, blood, or cerebrospinal fluid should be descended from a single bacterium. Cultures should then contain only one of the variants. Single variant nasopharyngeal cultures were obtained from 8 out of 19 (42%) rats when the intranasal inoculum was <100 organisms. As the inoculum was increased, single variant cultures were less frequently observed. When the inoculum was >/=10(5) organisms, nasopharyngeal cultures were always mixtures. Single variant blood cultures were obtained in 46 of 67 (68.7%) episodes of bacteremia when rats were inoculated intranasally with 10(8) organisms. Single variants were isolated from the cerebrospinal fluid of 13 of 19 (68.4%) rats with meningitis whose blood contained both streptomycin-sensitive and streptomycin-resistant variants. When the blood contained a single variant, this same variant was cultured from the cerebrospinal fluid on 39 of 40 (97.5%) occasions. These studies demonstrated that invasive. H. influenzae b infections of infant rats resulted from independent action, as opposed to cooperative interaction of intransally inoculated organisms. The results also suggested that the meninges were invaded by the hematogenous route.
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PMID:Haemophilus influenzae bacteremia and meningitis resulting from survival of a single organism. 30 28

We have developed a new micro-broth-dilution assay for determining the antimicrobial susceptibility of Haemophilus influenzae. This assay is based on the ability of viable H. influenzae to reduce nitrates to nitrites. Bacterial viability is detected by a positive nitrite reaction rather than visible turbidity. The nitrate reduction assay was compared with a standard microassay using 51 isolates of H. influenzae and six beta-lactam antibiotics. Although there was good agreement between the two methods, the nitrate reduction assay was more sensitive in detecting viable bacteria, and so established a more accurate estimate of the minimal inhibitory concentration. The nitrate reduction assay offered the additional advantage that it could be used to determine the minimal bactericidal concentration without having to subculture the broth. Ampicillin, penicillin, and cefamandole were equally effective in vitro against susceptible strains (minimal inhibitory concentrations, 0.125 to 0.5 mug/ml), whereas all three antibiotics were ineffective against two beta-lactamase-producing strains. Using the nitrate reduction assay, resistance to cefamandole was detectable with inoculum sizes ranging from 10(4) to 10(6) colony-forming units per ml, while the turbidity assay detected resistance only with the largest inoculum.
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PMID:Nitrate reduction: new method for testing the antibiotic susceptibility of Haemophilus influenzae. 30 65

Sulfamethoxazole-trimethoprim and three oral cephalosporins, cefaclor, cephalexin, and cephradine, were evaluated in vitro as possible alternatives to chloramphenicol in the treatment of non-central nervous system infections due to ampicillin-resistant Haemophilus influenzae. Sixty-four isolates of H. influenzae, including 31 beta-lactamase-positive strains, were tested by the agar dilution method. All strains were inhibited by 0.78/0.039 mug sulfamethoxazole-trimethoprim per ml and by 0.78 mug of chloramphenicol per ml. At 6.25 mug/ml, 100, 11, and 3% of all strains were inhibited by cefaclor, cephalexin, and cephradine, respectively. Thus, on the basis of drug concentrations presumably achievable in serum, 100% of strains were susceptible to sulfamethoxazole-trimethoprim, chloramphenicol, and cefaclor. However, a considerable inoculum effect was noted with both beta-lactamase-positive and -negative strains, when tested with sulfamethoxazole-trimethoprim; the minimal inhibitory concentrations of cefaclor were only slightly affected. Also, synergistic effects of sulfamethoxazole-trimethoprim, sulfamethoxazole-erythromycin, and sulfamethoxazole-cefaclor were seen when combinations were tested against both beta-lactamase-positive and -negative strains, as determined by minimal inhibitory concentrations measured by the broth dilution method and by killing curve analyses. These results support further evaluation of these combinations and of cefaclor alone for the treatment of non-central nervous system infections due to H. influenzae.
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PMID:In vitro susceptibility of Haemophilus influenzae to sulfamethoxazole-trimethoprim and cefaclor, cephalexin, and cephradine. 30 67


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