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 activity of the new oral cephalosporin Bay v 3522 was compared to that of six other beta-lactam agents. Bay v 3522 inhibited methicillin-susceptible Staphylococcus aureus and Staphylococcus epidermidis at less than or equal to 2 micrograms/ml, compared to MICs of greater than or equal to 8 micrograms/ml for the other cephalosporins tested. It was more active against Streptococcus pyogenes (MIC less than or equal to 0.06 microgram/ml) than cefuroxime, cefixime, cephalexin and cefaclor. Groups B, C and G streptococci were inhibited at less than or equal to 0.12 microgram/ml, while the MI"90 for Streptococcus bovis and viridans streptococci was 0.5 and 2 micrograms/ml, respectively. The MIC90 for enterococci and Listeria monocytogenes was 8 micrograms/ml. Clostridium perfringens was inhibited by 0.12 microgram/ml, but most Bacteroides spp. were resistant. The MIC90 for beta-lactamase positive Escherichia coli (producing primarily TEM-1) was greater than 64 micrograms/ml and for beta-lactamase negative strains 16 micrograms/ml. The MIC90 for high-level beta-lactamase producing Klebsiella pneumoniae was greater than 64 micrograms/ml versus 4 micrograms/ml for other isolates. The MIC90 for Moraxella catarrhalis was 2 micrograms/ml, for Haemophilus influenzae 1 micrograms/ml, and for Neisseria gonorrhoeae 4 micrograms/ml. Enterobacter cloacae, Citrobacter freundii, Proteus mirabilis, Providencia spp. and Pseudomonas aeruginosa were resistant. Bay v 3522 was destroyed by TEM-1, SHV-1, TEM-3 and P99 beta-lactamases.
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PMID:In vitro activity and beta-lactamase stability of the new oral cephalosporin Bay v 3522. 222 99

A 10-year-old boy presented with nuchal rigidity and cerebrospinal fluid (CSF) leukocytosis initially and again on day 6 of intravenous cefuroxime therapy (200 mg/kg/day). Both CSF specimens yielded nontypable beta-lactamase-negative Haemophilus influenzae that were susceptible by disk tests but relatively resistant to cefuroxime (MIC, 8- to 16-fold greater than that of control isolates). To define the mechanism of resistance, the cefuroxime resistance marker was transformed to a susceptible H. influenzae recipient; inactivation and permeability of beta-lactam substrate were tested and the penicillin-binding protein (PBP) profiles were examined. Inactivation of beta-lactam substrate was not detected and reduced permeability was not found. However, reduced beta-lactam binding to PBPs 4 and 5 was observed; 18- to 27-fold more penicillin and 2.5-to 4-fold more cefuroxime was required to saturate or block 50% of the binding sites of these PBPs, respectively. Thus, reduced affinity of PBPs 4 and 5 for beta-lactam substrate appears to be the mechanism of cefuroxime resistance in this strain. The reduced affinity of these targets appears to have contributed to the bacteriologic and clinical failure in this patient.
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PMID:Cefuroxime treatment failure of nontypable Haemophilus influenzae meningitis associated with alteration of penicillin-binding proteins. 223 Feb 38

Antimicrobial activities of sulbactam (SBT) with ampicillin (ABPC) or with cefoperazone (CPZ), in other words, the effects of SBT, an beta-lactamase inhibitor, against beta-lactamase producing strains of clinical isolates, were studied using microdilution broth method. 1. beta-Lactamase producing strains such as Staphylococcus aureus, Branhamella catarrhalis, Haemophilus influenzae, Escherichia coli and Klebsiella pneumoniae decompose benzylpenicillin (PCG) which is one of substrates of the acid-metry disc method and show a strong reaction, while they do not decompose cefazolin (CEZ), another substrate, showing no or weak reaction. Thus, it is suspected that beta-lactamases produced by these organisms are mainly penicillinase (PCase). MIC-distributions of ABPC and CPZ against these clinical isolates which seemed to produce PCase shifted to lower MIC ranges with MIC's reduced to 1/4 or below when 0.025 to 0.39 microgram/ml of SBT was added. 2. It appears that beta-lactamase produced by Proteus vulgaris may be oxyiminocephalosporinase (CXase), because P. vulgaris showed strong reaction on CEZ, but moderate reaction on PCG in the acid-metry disc method. MIC-distribution of ABPC and CPZ against P. vulgaris shifted to a lower range with MIC's of 1/4 or below when 0.20 to 0.39 microgram/ml of SBT was added. 3. All the test strains of Pseudomonas aeruginosa showed strong reaction on CEZ but only 56% of the test strains showed reaction on PCG. It appears that the beta-lactamases which showed strong reaction on CEZ is cephalosporinase and is encoded in chromosome, while those beta-lactamase that showed strong reaction on PCG is encoded in a plasmid which was acquired secondarily by P. aeruginosa. MIC-distribution of CPZ against P. aeruginosa shifted to a lower range with MIC values of 1/2 or below with the addition of SBT at 1.56 micrograms/ml. 4. It appears that the synergy of SBT with ABPC or with CPZ against the PCase or CXase producing strains may occur in the presence of SBT at a concentration far less than that reported previously.
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PMID:[Synergy between sulbactam and ampicillin or cefoperazone in antimicrobial activity against beta-lactamase producing microorganisms. Results with the use of microdilution broth method]. 223 51

We determined the MICs of ampicillin, methicillin, cefaclor, cefixime, cefteram, ofloxacin and ciprofloxacin against a total of 1,448 strains from 11 species: 464 strains of Staphylococcus aureus, 306 strains of Streptococcus pneumoniae, 114 strains of Streptococcus pyogenes, 37 strains of Branhamella catarrhalis, 329 strains of Haemophilus influenzae, 32 strains of Escherichia coli, 66 strains of Klebsiella pneumoniae, 26 strains of Enterobacter cloacae, 20 strains of Serratia marcescens, 12 strains of Pseudomonas aeruginosa and 42 strains of Acinetobacter calcoaceticus, isolated from the throat swab and the sputum of 2,539 patients with respiratory infections who visited 21 private clinics in Tohoku district of Japan during the period from January to April in 1989. Ciprofloxacin and ofloxacin were more active against S. aureus, B. catarrhalis, P. aeruginosa and A. calcoaceticus than other antibiotics. Ampicillin and cefteram were more active against S. pneumoniae and S. pyogenes than other antibiotics. New-quinolones and cephems of new-generation were active against H. influenzae, E. coli, K. pneumoniae, E. cloacae and S. marcescens. Of 30 strains of S. aureus which were resistant (MIC greater than or equal to 12.5 micrograms/ml) to ampicillin, only one strain was resistant (MIC greater than or equal to 12.5 micrograms/ml) to methicillin. Twenty strains (6.5%) of S. pneumoniae and 49 strains (14.9%) of H. influenzae were resistant (MIC greater than or equal to 1.56 micrograms/ml) to ampicillin. Of 101 strains of H. influenzae of which their beta-lactamase activity was determined by Nitrocephin-method, 27 (26.7%) were beta-lactamase-positive strains. The above results indicated that MRSA is only rarely found in primary care clinics but the incidence of ampicillin-resistant H. influenzae in primary care clinics is almost the same as that of the intensive care clinic, i.e. medical school-affiliated hospitals. Therefore caution should be exercised as regards antibiotic resistance of the causative organism even in primary care clinics.
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PMID:[Studies on respiratory infections in primary care clinic (IV). Antibiotic sensitivity of bacteria isolated from patients with respiratory infections visiting 21 private clinics in the Tohoku District of Japan]. 224 94

The antibacterial activity of cefpodoxime, a new orally active methoxy-imino cephalosporin was evaluated in 470 recent isolates of gram-positive cocci and gram-negative rods from clinical specimens and compared to that of other orally active beta-lactam compounds. Cefpodoxime was highly active against ampicillin-resistant enterobacteria producing the plasmid-mediated TEM-1, TEM-2 or OXA-1 enzymes, as was the case for the other newer compounds. However, it was poorly active against cefuroxime-resistant (MIC greater than or equal to 16 mg/l) E. coli isolates, thus resembling cefetamet and cefixime. It was inactive against isolates exhibiting a production of large amounts of class I beta-lactamase, as was the case with all other compounds studied. Cefpodoxime was highly active against beta-hemolytic streptococci and against Haemophilus influenzae, resembling the related agents. Moreover, its activity against Staphylococcus aureus was comparable to that of cefotaxime and exceeded that of cefetamet and cefixime. Cefpodoxime and the other methoxyimino cephalosporins exhibited a poor affinity to the plasmid-mediated TEM-2 and OXA-1 enzymes. The hydrolysis of cefpodoxime by class I beta-lactamases was barely detectable, whereas it served as a moderate substrate for the enzyme from Klebsiella oxytoca 3951. Cefpodoxime, cefetamet and cefixime were slowly inactivated by the enzyme from Proteus vulgaris 4917 (an enzyme with cefuroximase activity) and much poorer substrates than cefotaxime.
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PMID:Cefpodoxime: comparable evaluation with other orally available cephalosporins. With a note on the role of beta-lactamases. 224 85

Antimicrobial activities of minocycline (MINO) against various clinical isolates, 270 strains obtained in 1988, were determined and the reliability of the MINO disc susceptibility test in estimating approximate values of MICs was studied. Clinical significance of a 4 category system for the interpretation of the disc tests, which is widely used in Japan, and that of a 3 category system used in the USA and Europe, were also evaluated to determine which system would be more suitable for the evaluation of proper dose levels of administration. In this study, MICs were determined using the agar dilution method at an inoculum level of 10(6) CFU/ml. MIC80 values of MINO against Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus pneumoniae were all less than or equal to 0.78 micrograms/ml. Those against Haemophilus influenzae, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis and Proteus vulgaris were 0.39, 6.25, 3.13, 25, 50 micrograms/ml, respectively. MIC80 values against Pseudomonas aeruginosa, Serratia marcescens, Enterobacter spp., and Citrobacter spp. were 50, 100, 50 and 12.5 micrograms/ml, respectively. The inhibition zones obtained with the disc method were compared with MICs. The results of MINO disc susceptibility test either with 200 micrograms disc (Showa) or 30 micrograms disc (prepared in this laboratory) were well correlated with MICs, showing the reliability of the disc method in estimating approximate values of MICs. In the 4 category classification system currently used, break points in MIC values proposed are ( ) MIC less than or equal to 2 micrograms/ml, (++) MIC greater than 2-10 micrograms/ml, (+) greater than 10-50 micrograms/ml, (-) MIC greater than 50 micrograms/ml. The results obtained with 200 micrograms and 30 micrograms discs showed false positive in 26.6% and 20.5% of the samples, and false negative in 5.8% and 23.6% of the samples, respectively. The disc results of S. aureus, S. epidermidis, S. pneumoniae, etc. were relatively well classified, but those of E. coli, K. pneumoniae, Proteus spp. were not, showing more false positive results. Changing the lower 2 MIC break points in the 4 category system to: ( ) MIC less than or equal to 3 micrograms/ml and (++) MIC greater than 3-15 micrograms/ml, the false positive results with both 200 micrograms and 30 micrograms discs were reduced to 12% and 6.2%, respectively. The false negative results were 5.8% and 23.6%, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Clinical laboratory approach to estimate effective administrative dose of minocyclin. Reevaluation of in vitro MIC break points in disc susceptibility test]. 226 62

A recently described medium (Haemophilus test medium [HTM]) for antimicrobial susceptibility testing of Haemophilus influenzae was evaluated in this study for broth microdilution testing of Streptococcus pneumoniae. A total of 137 clinical isolates was tested against 11 antimicrobial agents, using Mueller-Hinton broth supplemented with 3% lysed horse blood in parallel with HTM. Inocula of 5 X 10(5) CFU/ml and incubation for 20 to 24 h were used with both media. All isolates of S. pneumoniae produced acceptable growth in both media, and MICs determined in HTM agreed closely with those determined in lysed horse blood. Drugs which provided a MIC within 1 log2 concentration difference in both media included penicillin (100%), ampicillin (98.0%), amoxicillin-clavulanate (100%), ampicillin-sulbactam (100%), cephalexin (98.9%), cefaclor (96.8%), cefuroxime (99.0%), chloramphenicol (96.2%), tetracycline (96.2%), and erythromycin (100%). HTM MICs with trimethoprim-sulfamethoxazole were 1 to 2 log2 concentration increments higher in 92.0% of isolates than MICs determined in lysed horse blood. Based on the results of this study, HTM appears to represent a promising alternative medium for broth microdilution susceptibility testing of S. pneumoniae.
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PMID:Use of Haemophilus test medium for broth microdilution antimicrobial susceptibility testing of Streptococcus pneumoniae. 232 70

WIN 57273 is a new fluoroquinolone that has an expanded spectrum of activity against Staphylococcus spp. (MIC for 90% of isolates [MIC90], 0.008 microgram/ml), Enterococcus faecalis (MIC90, 0.06 microgram/ml), Bacillus spp. (MIC90, 0.03 micrograms/ml), Listeria monocytogenes (MIC90, 0.06 microgram/ml), Streptococcus spp. (MIC90, 0.03 microgram/ml), and Bacteroides fragilis group strains (MIC90, 0.5 microgram/ml). Like other fluoroquinolone compounds, WIN 57273 was active against members of the family Enterobacteriaceae (97% of strains inhibited by less than or equal to 2 micrograms/ml), Haemophilus, Branhamella, and Neisseria strains (100% susceptible), Acinetobacter spp. (100% susceptible), and Pseudomonas aeruginosa (68% susceptible). We observed that WIN 57273 was very active against cephalosporin- or aminoglycoside-resistant gram-negative strains but shared cross-resistance with other fluoroquinolones. Increasing inoculum concentrations had minimal effects on WIN 57273 MICs, and the drug was considered to be bactericidal based on reference MBC and kill curve analyses. Unlike most previously studied drugs in this class, WIN 57273 had increased activity (three- to fourfold) at low pH. Rates of mutation to WIN 57273 resistance at eight times its MIC were in the range of 5.6 x 10(-8) to greater than 1.4 x 10(-9). This new compound possesses a wide potential spectrum of use, and it should be evaluated further by in vitro and in vivo studies.
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PMID:In vitro evaluation of WIN 57273, a new broad-spectrum fluoroquinolone. 232 79

The in vitro susceptibility of Haemophilus influenzae type b to rifampin, cefotaxime, ceftazidime, ceftriaxone and cefuroxime was examined at inocula of 10(5) and 10(7) CFU/ml. Time-kill curves were then obtained using antibiotic concentrations at one-half the MIC for each drug at the two inocula with combinations of rifampin plus each of the cephalosporins. There was a pronounced inoculum effect with all of the cephalosporins except for cefuroxime, but the MIC values were also higher for the latter drug. The rare failure of some cephalosporins to promptly sterilize the cerebrospinal fluid in meningitis should encourage investigation of the relationship between the inoculum effect, minimum bactericidal concentration and cerebrospinal fluid antibiotic levels in these clinical situations. A marked synergistic effect was noted for most of the isolates, and therefore, cephalosporin-rifampin combinations might show clinical utility.
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PMID:In vitro synergism of rifampin-cephalosporin combinations against Haemophilus influenzae type b. 233 89

The antibacterial activity of a new 7-dimethylpyridinyl quinolone, WIN 57273, was assessed by using in vitro and in vivo models. Agar inclusion and broth dilution in vitro tests revealed broad-spectrum activity against gram-positive and selected gram-negative organisms, with the greatest potency observed against the staphylococci. The MIC for 90% of coagulase-positive strains tested (MIC90) was less than or equal to 0.002 micrograms/ml; for the coagulase-negative strains the MIC90 was 0.008 micrograms/ml. Against enterococci the MIC90 was 0.06 micrograms/ml, with comparable activity observed against group A and group B streptococci as well as against the pneumococci. In general, the MIC90s for the gram-negative bacteria were less than or equal to 1 micrograms/ml. Exceptions were Serratia marcescens (MIC90, 16 micrograms/ml), Citrobacter freundii (MIC90, 4 micrograms/ml), and Pseudomonas aeruginosa (MIC90, 8 micrograms/ml). The greatest potency was observed against Haemophilus spp. and Neisseria spp., with MIC90s of 0.06 and 0.016 micrograms/ml, respectively. Broad-spectrum activity was also observed against anaerobes, with MIC90s ranging from 0.125 to 0.5 micrograms/ml among the species tested. The in vivo efficacy was determined by using a murine model by calculating the 50% protective doses against a lethal bacterial infection caused by strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Streptococcus pyogenes, Listeria monocytogenes, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The staphylocci were most susceptible, with 50% protective doses for all strains ranging from 0.1 to 0.7 mg/kg. With the exception of the Pseudomonas infection, which was refractory to treatment, animals that were part of the other infection models responded to less than 10 mg/kg. Equivalent activity was seen with the subcutaneous or the oral route of drug administration. WIN 57273 was significantly more potent than ciprofloxacin in treating gram-positive bacterial infections (2- to 20-fold) but was significantly less effective at treating gram-negative bacterial infections (30- to 300-fold).
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PMID:In vitro and in vivo activities of a new quinolone, WIN 57273, possessing potent activity against gram-positive bacteria. 234 63


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