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 in vitro activity of piperacillin, a new semisynthetic piperazine penicillin derivative, was evaluated against 626 clinical isolates and compared with the activity of other beta-lactam antibiotics. At a concentration of 0.1 microgram/ml, piperacillin inhibited all streptococci except enterococci. Non-beta-lactamase-producing staphylococci were inhibited by 1.6 microgram or less per ml. Both beta-lactamase- and non-beta-lactamase-producing Haemophilus were inhibited by 0.1 microgram/ml. Piperacillin inhibited non-beta-lactamase-producing Escherichia coli, Salmonella, and Shigella at a concentration of 6.3 micrograms/ml, but 20% of strains of these species containing type III beta-lactamase were not inhibited by 100 micrograms/ml. Piperacillin at 25 micrograms/ml, inhibited 83% of Citrobacter, 58% of Klebsiella, 88% of Enterobacter, and 50% of indole-positive Proteus, Acinetobacter, and Providencia. At 25 micrograms/ml, piperacillin inhibited 95% of Pseudomonas aeruginosa and 78% of Bacteroides fragilis. The minimal inhibitory concentration of piperacillin against Pseudomonas was affected by increasing the inoculum size and by pH. Minimum bactericidal concentrations against Pseudomonas and Serratia often were eightfold greater than the minimum inhibitory concentrations. Piperacillin was equal in activity to ampicillin against enterococci. It was more active than carbenicillin against E. coli, Klebsiella, Enterobacter, and Bacteroides. It was the most active penicillin against Pseudomonas and inhibited many strains of Pseudomonas for which the MICs of carbenicillin were above 200 micrograms/ml. Piperacillin was hydrolyzed by many different beta-lactamases. Synergistic activity of piperacillin was demonstrated when it was combined with amikacin, gentamicin, and cefazolin against P. aeruginosa and members of the Enterobacteriaceae. No antagonism was observed when piperacillin was combined with aminoglycosides; however, antagonism was observed rarely against E. coli when piperacillin was combined with cefazolin.
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PMID:Piperacillin, a new penicillin active against many bacteria resistant to other penicillins. 12 19

The in vitro activity of cefuroxime, a cephalosporin antibiotic, was investigated against 604 isolates and compared with the activity of other beta-lactam compounds. Cefuroxime had activity comparable to that of other cephalosporins, including cefamandole and cefoxitin, against streptococcal and staphylococcal species; most streptococci were inhibited by 0.1 mug or less per ml, and staphylococci were inhibited by 1.6 mug or less per ml. Enterococci were relatively resistant. Cefuroxime inhibited beta-lactamase-producing Neisseria gonorrhoeae and Haemophilus influenzae. Cefuroxime had excellent activity against members of the Enterobacteriaceae; 83% of beta-lactamase-producing Escherichea coli, 100% of Salmonella, 100% of Klebsiella, 90% of Proteus mirabilis, 95% of Citrobacter, 56% of Enterobacter, and 58% of Shigella were inhibited by 12.5 mug/ml. Cefuroxime had activity comparable to that of cefamandole and cefoxitin; it inhibited isolates of E. coli and Klebsiella resistant to cefamandole and inhibited Enterobacter and Citrobacter resistant to cefoxitin. Many isolates of Serratia, some indole-positive strains of Proteus, and Bacteroides fragilis were resistant to cefuroxime. Resistance of cefuroxime to hydrolysis by beta-lactamases played a major role in its activity against both gram-positive and gram-negative organisms.
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PMID:Cefuroxime, a beta-lactamase-resistant cephalosporin with a broad spectrum of gram-positive and -negative activity. 24 68

The antibacterial activities of three aminopenicillins ampicillin, epicillin and amoxycillin were compared in vitro and in vivo. The minimum inhibitory concentrations (MIC) of the three penicillins were very similar and the compounds were active against non-beta-lactamase-producing strains of Escherichia coli, Salmonella and Shigella species, Proteus mirabilis, Haemophilus influenzae and Neisseria gonorrhoeae. Streptococci including Streptococcus faecalis, and non-beta-lactamase-producing staphylococci were also sensitive to the compounds but Pseudomonas aeruginosa, Klebsiella aerogenes, Enterobacter and indole-positive Proteus species were resistant. At concentrations close to MIC value epicillin and ampicillin showed similar bactericidal activity against E. coli and against S. typhi and both compounds caused a slower rate of kill than was seen with amoxycillin. Microscopical observation of the cells exposed to ampicillin and epicillin for 1 h showed the presence of filamentous forms which lysed slowly, whereas cells exposed to amoxycillin for the same period rapidly. Epicillin was similar to or slightly less active than ampicillin against experimental mouse infections, and against the majority of infections both compounds were significantly less effective than amoxycillin by the oral and subcutaneous routes of administration.
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PMID:Comparative activities of ampicillin, epicillin and amoxycillin in vitro and in vivo. 25 24

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

Two culturing recipes were suggested for Pasteurella multocida and Pasteurella haemolytica, one partialy defined nutritive defined nutritive medium with 0.5 per cent yeast extract and one chemically defined medium. Both had been composed on the basis of studies into nutrient demand and into the effects of complex nutritive substrates. Both nutritive media are applicable also to culturing other bacterial species. (Among the strains tested so far were streptococci, staphylococci, Escherichia coli, pseudomonas, protest, Salmonella,, Shigella, and Haemophilus.)
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PMID:[Chemically defined and partially defined media for pasteurella multocida and pateurella hemolytica]. 32 33

Using a triple agar layer technique and enzymatic inactivation of penicillin, the occurrence of a paradoxical zone phenomenon (illustrated by a typical 'target' image around the reservoir of antibiotic) was determined for several bacterial species specially chosen with regards to their taxonomic position, clinical importance and penicillin susceptibility. Among gram-positive bacteria, a paradoxical zone was obtained for approximately 43% of the strains studied here (all 10 strains of Staphylococcus aureus, all 10 strains of Streptococcus faecalis, 7 of 10 strains of group B beta-hemolytic streptococci, 1 of 10 group A strains, 3 of 10 strains of alpha-hemolytic streptococci, 3 of 10 strains of Clostridium perfringens but for none of 10 strains each of Streptococcus pneumoniae, and Listeria monocytogenes). Among gram-negative bacteria, a target image was regularly obtained with Haemophilus influenzae (all 10 strains tested) and Proteus species (9 of 10 strains) but with none of the following species: Escherichia coli, Salmonella, Shigella, Pseudomonas aeruginosa, Neisseria gonorrhoeae, Neisseria meningitidis and Bacteroides fragilis. Therapeutic implications of these observations are difficult to assess, and need further investigation.
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PMID:Qualitative study of paradoxical zone phenomenon of penicillins against 17 bacterial species of clinical importance. 34 Jan 71

The mechanism of action, antimicrobial spectrum, pharmacokinetic properties, drug interactions, adverse reactions and therapeutic uses of trimethoprim-sulfamethoxazole, a combination enzyme-specific inhibitor of bacterial folate synthesis, are reviewed. Trimethoprim-sulfamethoxazole currently is approved by the FDA for the therapy of established recurrent bacterial urinary tract infections, pneumocystosis, otitis media in children and shigellosis. Claimed advantages of the drug are synergistic activity, bactericidal activity and ability to decrease the rate of emergence of resistance to the individual components. Trimethoprim-sulfamethoxazole is the drug of choice for treatment of pneumocystosis and an acceptable oral therapy for recurrent urinary tract infections caused by susceptible bacteria. In children with otitis media, it is used as an alternative to ampicillin and amoxicillin and is preferred when these patients are penicillin-sensitive or when the infection is caused by beta-lactamase-producing Haemophilus influenzae. Hematologic reactions (anemia, thrombocytopenia, granulocytopenia, agranulocytosis) to trimethoprim-sulfamethoxazole occur rarely. Gastrointestinal intolerance and skin eruptions are the most prevalent adverse reactions. Most untoward reactions to trimethoprim-sulfamethoxazole develop within two weeks of onset of therapy, and their incidence compares favorably with that of standard agents administered for the same indications.
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PMID:Drug therapy reviews: trimethoprim-sulfamethoxazole. 38 41

The in vitro activity of HR 756, 7-[2-(2-amino-4-thiazolyl)-2-(Z)-(methoximino)acetamido] cephalosporanic acid, was investigated against 659 isolates. HR 756 inhibited Neisseria and Haemophilus species at concentrations similar to those needed with ampicillin. It inhibited beta-lactamase-producing N. gonorrhoeae and H. influenzae. HR 756 was the most active compound tested against members of the Enterobacteriaceae, inhibiting most isolates of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Salmonella, Enterobacter, and Shigella at concentrations of less than 0.1 mug/ml. It was twice as active as carbenicillin against Pseudomonas aeruginosa and inhibited Bacteroides fragilis as well as cefoxitin. HR 756 killed E. coli, Staphylococcus aureus, and P. aeruginosa at rates similar to other beta-lactam antibiotics.
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PMID:HR 756, a new cephalosporin active against gram-positive and gram-negative aerobic and anaerobic bacteria. 42 18

The ability of potential pathogens to acquire iron in a host is an important determinant of both their virulence and the nature of the infection produced. Virulent gram-negative bacteria are capable of acquiring sufficient iron from the host because their virulence (for chick embryos) is unaffected by exogenous iron. Avirulent mutants which are apparently limited in their ability to acquire iron could be isolated from the virulent strains. The lethality of these mutants was significantly enhanced by exogenous iron. Reduction of the relatively high serum iron saturation of chick embryos (to levels more closely approximating those in man) by pretreatment with iron-binding proteins or endotoxin inhibits the lethality of some virulent bacteria. Those bacteria whose virulence was reduced include the Shigella, Vibrio cholerae and strains of Neisseria gonorrhoeae, all of which are nondisseminating pathogens in the normal human host. Pathogens which produce septicemic and disseminating infections such as Neisseria meningitidis, Haemophilus influenzae type B, Escherichia coli possessing K-1 antigen, Pseudomonas aeruginosa and Salmonella typhimurium and disseminating strains of N. gonorrhoeae were, in general, unaffected by reduced serum iron saturation. These disseminating bacteria appeared to produce greater quantities of compounds (siderophores) which stimulated microbial growth in low-iron media than did the nondisseminating pathogens. Thus, the gram-negative bacteria tested can be divided into four major classes according to their responses to modifications in iron levels in the chick embryo model and these results correlate with the nature of the infections which they typically produce in man.
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PMID:The critical role of iron in host-bacterial interactions. 65 5

The in vitro activity of cefaclor against 556 clinical isolates of gram-positive and gram-negative bacteria was compared with that of other cephalosporins. Cefaclor had activity similar to that of cephalexin against gram-positive bacteria. It showed greater activity against Haemophilus strains than did cephalexin and inhibited beta-lactamase-producing Haemophilus isolates. Cefaclor was more active than cephalexin or cephalothin against Escherichia coli, Salmonella, and Shigella isolates but did not act against Serratia, Acinetobacter, indole-positive Proteus, or Bacteroides isolates. Cefaclor was resistant to type III (TEM) beta-lactamases but was destroyed by type I beta-lactamases and, to a lesser degree, by type IV and type V beta-lactamases.
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PMID:Cefaclor: in vitro spectrum of activity and beta-lactamase stability. 66 90


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