Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The minimal inhibitory concentration of cefaclor, cephalexin, cephradine, cefamandole, cephalothin, cephapirin, cefazolin, ampicillin, chloramphenicol, and tetracycline for inhibition of 198 freshly isolated clinical strains of Haemophilus species (23 H. influenzae type b, 157 H. influenzae non-type b, 14 H. parainfluenzae, and 4 H. aphrophilus) was determined simultaneously by a slightly modified WHO-ICS agar dilution method. Nine strains were resistant to ampicillin. There was no correlation between ampicillin resistance and minimal inhibitory concentration of other antibiotics. All strains were susceptible to chloramphenicol, and all except five were susceptible to tetracycline. Cefaclor was the most active oral cephalosporin, and cefamandole was the most active parenteral cephalosporin. Among the seven cephalosporins tested, cefamandole was the most effective compound. All but two strains were inhibited by cefamandole at 2 mug or less per ml.
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PMID:Comparative susceptibility of Haemophilus species to cefaclor, cefamandole, and five other cephalosporins and ampicillin, chloramphenicol, and tetracycline. 25 12

Haemophilus influenzae is an important pathogen in respiratory infections in children and often is implicated in otitis media. It is sensitive in vitro to a number of antibiotics, some of which are used clinically for the treatment of such infections. We have checked the in vitro sensitivity of a type b strain of H. influenzae. When tested in Levinthal's broth prepared with laked rabbit blood, the culture was most sensitive to tetracycline, ampicillin and penicillin and was somewhat less sensitive to cephalothin, fosfomycin, cephaloridine, and chloramphenicol. However, when this same strain was used to infect mice, fosfomycin was more active than ampicillin, tetracycline, chloramphenicol, penicillin or the cephalosporins.
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PMID:Fosfomycin treatment of Haemophilus influenzae infection in mice. 29 38

Nonimmune rats given intravenous inoculations of 10(8) encapsulated Haemophilus influenzae type b cleared the bacteria at an exponential rate for 10 min; thereafter, the bacteremia plateaued at approximately 10(6) organisms/ml of blood. With 10(8) unencapsulated organisms, the initial clearance rate was significantly faster (P less than 0.001) and was complete by 30 min. The rate of clearance of a mutant strain of H. influenzae type b containing 0.1% as much capsular polysaccharide as the wild type was significantly faster (P less than 0.01), and H. influenzae type b from which a portion of the capsule had been removed physically had an intermediate clearance pattern. The addition of 1-1,000 mug of capsular polysaccharide to an inoculum of 10(8) organisms did not alter the clearance of the capsular polysaccharide-deficient mutant. The quantity of bacteria cleared during the 30 min after inoculation increased with the age of the animal. The initial bacterial clearance rate, corrected for animal and organ weight, also increased with age. These data are consistent with the proposal that physically integrated capsular polymer increases the virulence of H. influenzae type b by rendering it resistant to clearance from the bloodstream and that there may be an age-related increase in phagocytic activity that is reflected in increased clearance.
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PMID:The role of encapsulation and host age in the clearance of Haemophilus influenzae bacteremia. 29 66

A rapid method for determining the minimal inhibition concentrations (MICs) of ampicillin using Haemophilus influenzae as the test organism is described. This semiautomated technique using the Autobac system was compared with the agar dilution MIC method. Fifty-seven isolates of both susceptible and resistant H. influenzae were tested. There was exact quantitative agreement with 65% of the isolates, and 91% of the isolates showed no more than a one-dilution-interval difference when MICs were determined by both methods. Total testing time was 3 to 4 h.
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PMID:Rapid method for determining the minimum inhibitory concentration of ampicillin for Haemophilus influenzae. 29 99

Empyema due to Hemophilus influenzae has been reported only rarely. This report describes the cases of ten children with empyema due to this organism. Diagnosis was made through growth of the organism in pure culture from pleural effusion. H. influenzae empyema may occur in older children as well as in infants and, in contrast to certain other infections with this organism, empyema due to H. influenzae may be more common than is generally suspected.
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PMID:[Pleuropulmonary lesions due to Haemophilus influenzae]. 30 24

Abnormalities in cerebrospinal fluid associated with meningitis due to Haemophilus influenzae type b were characterized in infant rats. After intranasal inoculation of bacteria, the development of intense bacteremia (greater than 10(4) colony-forming units/ml) correlated with cultures of cerebrospinal fluid positive for H. influenzae, with pleocytosis, and with hisotologic evidence of meningitis. The degree of pleocytosis was related to the age of the animal, the amount of time since inoculation, and the severity of the meningitis.
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PMID:Haemophilus influenzae meningitis in infant rats: role of bacteremia in pathogenesis of age-dependent inflammatory responses in cerebrospinal fluid. 30 94

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

Immunization with ribosomal preparations from Haemophilus influenzae type b elicited protective immunity in mice. Ribosomes from disrupted cells where isolated by differential centrifugation using sodium dodecyl sulfate. The washed ribosomes contained 25% protein and 75% ribonucleic acid and sedimented as a single peak on sucrose density gradient analysis with a sedimentation coefficient of 67S, using Escherichia coli ribosomes as a 70S marker. Immunodiffusion tests with antipolyribose phosphate serum showed that the ribosomes were free from capsular material. Mice immunized subcutaneously with ribosomes, with or without adjuvant, were challenged intraperitoneally with 100 to 1,000 mean lethal doses of H. influenzae type b suspended in gastric mucin. Significant protection was induced by ribosomes and was compared to that obtained after sublethal infection with live cells. The protection was greatly enhanced after incorporation of ribosomes into adjuvants. Maximum protection (90 to 95%) was observed at 1 to 2 weeks after immunization. Ribosomes from a nonencapsulated strain of H. influenzae were as immunogenic as those from the encapsulated strain, demonstrating that the capsular material is not responsible for immunogenicity of Haemophilus ribosomes.
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PMID:Immunoprotective activity of ribosomes from Haemophilus influenzae. 30 Mar 60

On the basis of their susceptibility to ampicillin, strains of Haemophilus influenzae can be divided into three types: type 1 are normally susceptible strains, type 2 produce stable spheroplasts from low inocula, and type 3 are beta-lactamase producers. Because of the production of spheroplasts, standard broth and agar dilution techniques have failed to differentiate between the responses of type 2 and 3 strains to ampicillin, or to identify the superiority of cefuroxime over ampicillin against the beta-lactamase-producing strains. Disk susceptibility tests with heavily seeded plates were also difficult to interpret. To overcome these problems, we developed a medium that supports the growth of H. influenzae, but not survival of spheroplasts, thereby reducing the complicating influence of spheroplast formation. Utilization of the medium made it possible to identify beta-lactamase-producing strains via both minimal inhibitory concentration and disk susceptibility techniques, as well as the superiority of cefuroxime over ampicillin against such strains. In vivo experiments showed that cefuroxime and ampicillin are equally active against infections with type 1 and 2 strains, but that cefuroxime is superior to ampicillin against infections with type 3 beta-lactamase-producing strains.
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PMID:Comparative acitivity of ampicillin and cefuroxime against three types of Haemophilus influenzae. 30 Oct 7

When aerobically grown on complex media, Haemophilus influenzae b and unencapsulated variants, Rb strains, produced a bactericidal factor that was active against other Haemophilus species and certain genera of the Enterobacteriaceae. A total of 341 clinical isolates of Haemophilus were tested for susceptibility to the factor. Ninety-three percent of H. influenzae (nontypable), 75% of H. haemolyticus, 71% of H. parainfluenzae, and 22% of H. parahaemolyticus were susceptible. H. influenaze b strains were resistant producers of the bactericidal factor and H. influenzae f strains were susceptible nonproducers. Only one strain each of H. aegyptius and H. aphrophilus was isolated and each was susceptible and resistant, respectively. 143 clinical isolates of the Enterobacteriaceae were tested and of those 82% of Escherichia coli, 85% of Salmonella sp., and all Citrobacter sp., Shigella sp., and Yersinia sp. were sensitive to the bactericidal factor produced by H. influenzae b. Attempts to isolate the bactericidal activity from mechanically disrupted, solubilized, or osmotically shocked cells failed to release active bactericidal factor. However, we partially purified the bactericidal factor from the spent culture medium of aerobically grown H. influenzae b by a series of extractions. The ability to produce the bactericidal factor was transferable to nonproducer strains without also genetically transforming for type b encapsulation. The converse was also true in that type b capsules were produced by transformed H. influenzae Rd strains but no bactericidal factor was detected from these strains. Additionally, nitrosoguanidine-induced mutants of H. influenzae b lost the ability to produce bactericidal factor without loss of their type-specific capsule, demonstrating that production of the bactericidal factor was genetically separable from production of the type capsule of H. influenzae b.
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PMID:Bactericidal factor produced by Haemophilus influenzae b: partial purification of the factor and transfer of its genetic determinant. 30 Oct 8


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