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)

Strains of Diplococcus pneumoniae and Haemophilus influenzae were tested for susceptibility to numerous antibiotics by a twofold agar dilution method using an inocula replicator. Undiluted, fully grown broth cultures were used as inocula for both species, and cultures of pneumococci diluted 1:1,000 were also tested. The antibiotics included most of those in common use in the United States as well as some chemical modifications recently approved and others that are under investigation. The most striking aspect of the results was the marked susceptibility of the pneumococci to all the antibiotics tested except the polymyxins and most of the aminoglycoside antibiotics, although some new aminoglycosides were active in quite low concentrations. Some of the strains of pneumococci were of decreased susceptibility to penicillin G (minimal inhibitory concentrations, 0.2 to 0.4 mug/ml), but none were tetracycline resistant, although such strains had been reported previously from this laboratory. The strains of H. influenzae, which were all serologically nontypable, exhibited different patterns of susceptibility to the groups of antibiotics and to the individual chemically related ones. None of these strains (isolated early in 1972) were ampicillin resistant. The most active agents against H. influenzae were: carbenicillin and ampicillin, analogues related to each of them, rifampin, chloramphenicol, and the polymyxins. However, the tetracycline analogues other than tetracycline, some aminoglycosides, notably tobramycin, kanamycin, gentamicin, and verdamicin, erythromycin, and some new lincomycin analogues were also active in low concentrations. Trimethoprim alone was highly active, and in combination with sulfamethoxazole it was even more active and synergistic against strains of both D. pneumoniae and H. influenzae.
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PMID:Susceptibility of pneumococci and Haemophilus influenzae to antibacterial agents. 0 52

The inability of sulfamethoxazole-trimethoprim (SXT) to eradicate Haemophilus influenzae nasopharyngeal carriage in all asymptomatic patients in closed populations was examined in vitro. A broth medium was adapted for susceptibility testing of H. influenzae which permitted us to determine minimum inhibitory concentrations and minimum bactericidal concentrations (MBCs). The minimum inhibitory concentrations were all low, but the MBCs were bimodally distributed. Trimethoprim alone or the combination SXT either was bactericidal for H. influenzae isolates at low concentrations (i.e., low MBCs) similar to minimum inhibitory concentrations or showed no bactericidal activity (i.e., high MBCs). If trimethoprim was bactericidal when tested alone against H. influenzae, then the combination SXT was also bactericidal. H. influenzae carriage could not be eradicated from asymptomatic patients with SXT therapy when that combination was not bactericidal for these isolates in vitro. H. influenzae carriage was eradicated from patients when the activity of SXT was bactericidal in vitro. H. influenzae strains that are not killed by trimethoprim or SXT seem to occur at random.
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PMID:Minimum bactericidal concentration of sulfamethoxazole-trimethoprim for Haemophilus influenzae: correlation with prophylaxis. 31 Feb 81

Antimicrobial resistance determinants and plasmids present in 10 multiply antibiotic-resistant strains of Hemophilus influenzae isolated from patients in different geographic regions of Spain were characterized. Conjugative plasmids with molecular sizes of 38-50 MDa encoded resistance to ampicillin, chloramphenicol, kanamycin, streptomycin, sulfamethoxazole, and tetracycline. Trimethoprim resistance was not linked to the other antibiotic resistance determinants and trimethoprim-resistant transconjugants and transformants lacked detectable plasmid DNA, suggesting that this determinant is chromosomal. Restriction endonuclease analysis revealed similarities among the plasmids, but several restriction patterns could be distinguished. Three hybridization patterns were found with DNA probes coding for H. parainfluenzae beta-lactamase and chloramphenicol-acetyltransferase. Resistance to kanamycin was due to drug modification by aminoglycoside-phosphotransferase (3')I. In Spain, it appears that multiple antibiotic resistance phenotypes in H. influenzae did not arise from acquisition of a single R plasmid; rather, both plasmid and chromosomal resistance evolved independently from several sources.
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PMID:Genetic relatedness of antibiotic resistance determinants in multiply resistant Hemophilus influenzae. 280 56

We studied 10 trimethoprim-resistant (Tmpr) Haemophilus influenzae isolates for which agar dilution MICs were 10 to greater than 200 micrograms/ml. Trimethoprim resistance was transferred from two Tmpr H. influenzae isolates to a Tmps strain by conjugation or transformation. Wild-type Tmpr strains and Tmpr transcipients did not contain detectable plasmid DNA. The trimethoprim resistance gene was cloned into a cosmid vector, and recombinant plasmids were transduced into Escherichia coli. A 0.50-kilobase intragenic probe derived from a 12.9-kilobase fragment which encoded trimethoprim resistance hybridized with whole-cell DNA from Tmps and Tmpr strains. Southern blot analysis of restricted DNA from isogenic Tmps and Tmpr H. influenzae indicated that acquisition of trimethoprim resistance involved a rearrangement or change in nucleotide sequence. Hybridization was not seen with DNA derived from Tmpr E. coli containing dihydrofolate reductase I, II, and III genes or with Tmpr Neisseria meningitidis, Neisseria gonorrhoeae, and Pseudomonas cepacia. Southern hybridization with 12 multiply resistant encapsulated H. influenzae strains confirmed that the trimethoprim resistance gene was chromosomally mediated. Dihydrofolate reductase activity was significantly greater in cell sonicate supernatants of Tmpr strains in comparison with isogenic Tmps recipients. Differences were not found in the trimethoprim inhibition profile of dihydrofolate reductase activity in Tmps and Tmpr strains. We conclude that the mechanism of trimethoprim resistance in H. influenzae is overproduction of chromosomally located dihydrofolate reductase.
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PMID:Molecular cloning and mechanism of trimethoprim resistance in Haemophilus influenzae. 283 38

A total of 126 strains of Haemophilus influenzae were examined for susceptibility to amoxicillin/clavulanic acid, trimethoprim/sulfamethoxazole, cefaclor, and erythromycin by an agar dilution procedure. Fifty strains (eight type B, 42 non-type B), all with ampicillin minimal inhibitory concentrations (MIC) of greater than or equal to 6.2 micrograms/ml, produced beta-lactamase. The remaining 76 strains (18 type B, 59 non-type B) were beta-lactamase-negative. All of these strains had ampicillin MICs of less than or equal to 0.8 micrograms/ml. The combination of amoxicillin and clavulanic acid (2:1) was highly active against all strains tested. With the exception of two strains with amoxicillin/clavulanic acid MICs of 1.6/0.8 ug/ml, all strains were inhibited by concentrations of less than or equal to 0.8/0.4 ug/ml. Trimethoprim/sulfamethoxazole was also found to be highly active (MICs uniformly less than or equal to 0.1/1.9 ug/ml). Cefaclor and erythromycin were the least active of the agents tested. Fourteen strains (10.6%) had cefaclor MICs of greater than 32 ug/ml. Forty-seven strains (35.6%) had erythromycin MICs of greater than 8 micrograms/ml. With the exception of amoxicillin/clavulanic acid beta-lactamase production did not seem to influence the activity of any of the antimicrobials tested. Minimum inhibitory concentrations of amoxicillin/clavulanic acid, although still well within achievable serum levels, were approximately one twofold dilution higher with beta-lactamase-producing H. influenzae type B strains than with beta-lactamase-negative strains.
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PMID:Susceptibility of Haemophilus influenzae to amoxicillin/clavulanic acid, erythromycin, cefaclor, and trimethoprim/sulfamethoxazole. 348 92

Children with HIV infection have an unusual susceptibility to bacterial infection, related to several immune abnormalities. Selection of initial antibiotic therapy must be individualized in these children. Patients with community-acquired disease are most likely to have infection by polysaccharide-encapsulated bacterial organism, most commonly Streptococcus pneumoniae and less frequently by Haemophilus influenzae type b. If it is possible to treat the patients at home, the use of amoxicillin-clavulanic acid might be appropriate. Other authors propose management with parenteral ceftriaxone because of the better compliance and the malabsorption. In hospitalized patients, concern for Gram-negative enteric pathogens other than polysaccharide-encapsulated organisms requires initial therapy with a third-generation cephalosporine in combination with an aminoglycoside. Trimethoprim-sulfamethizole is the most common drug used in HIV-infected children because it is recommended for the initial therapy and for prophylaxis of pneumocystis carinii pneumonia, which occurs in as many as 42% of these children.
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PMID:The use of antibiotics in the treatment and prevention of infection in HIV-infected children. 783 66

Acute conjunctivitis, one of the most frequently seen eye diseases in infants and children, is associated with a shorter duration of clinical disease when antimicrobial agents are used. Although viruses often are implicated as causative agents, Haemophilus influenzae and Streptococcus pneumoniae are the most commonly isolated bacterial pathogens. Empiric therapy of acute conjunctivitis therefore should include agents with both gram-positive and gram-negative antimicrobial activity. Trimethoprim-polymyxin B is a broad-spectrum antimicrobial agent available as an ophthalmic solution. We conducted a patient outcomes study to evaluate the subjective response to treatment with trimethoprim-polymyxin B of children with presumed acute bacterial conjunctivitis. Questionnaires were distributed to more than 100 pediatricians who assessed outcome measures in 472 children with acute bacterial conjunctivitis for whom they prescribed trimethoprim-polymyxin B. The parameters evaluated were clinical outcome, overall efficacy, and comfort provided by the medication regimen. The physicians reported that 95% of the infected eyes were cured or improved within 7 days. In addition, the overall efficacy trimethoprim-polymyxin B was rated as excellent or good in 76% and 20% of cases, respectively. With regard to patient comfort, patients or their caregivers reported that patients were very comfortable or moderately comfortable in 62% and 27% of cases, respectively. Four adverse events were reported; all were transient and of mild-to-moderate intensity. The survey results support clinical research findings on the comparative efficacy and safety of trimethoprim-polymyxin B ophthalmic solution compared with other ophthalmic antimicrobial agents. The pediatricians in our survey who prescribed trimethoprim-polymyxin B ophthalmic solution for children with presumed acute bacterial conjunctivitis reported that this medication was effective and well tolerated.
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PMID:Results of a survey of children with acute bacterial conjunctivitis treated with trimethoprim-polymyxin B ophthalmic solution. 859 39

One thousand seventy-three bacterial isolates were collected from patients with community acquired respiratory tract infections (CARTI) in 11 Latin American centers (7 countries) during 1997 and 1998. They were tested against numerous antimicrobial agents by the reference broth microdilution method as part of the ongoing multinational SENTRY Antimicrobial Surveillance Program. Among Streptococcus pneumoniae (553 isolates), approximately 61% were susceptible to penicillin. There was a great variation of the penicillin susceptibility rates among participating countries. The highest susceptibility rates were found in Argentina (76.7%) and Brazil (71.9%), while the lowest rate of penicillin susceptibility was detected in Mexico (33.3%). High level resistance to penicillin and resistance to cefotaxime were observed in nearly 10% of the isolates. The newer quinolones, levofloxacin (MIC(90) 2 microg/mL) and gatifloxacin (MIC90 0.5 microg/mL), were active against 100% of the isolates tested. Among the other non-beta-lactams drugs tested, the rank order of susceptibility against the pneumococci was: chloramphenicol (93.9%)>clindamycin (93.2%)> azithromycin (89.1%) > clarithromycin (88.7%)>tetracycline (78.5%)> trimethoprim/sulfamethoxazole (55.7%). The percentage of Haemophilus influenzae (361 isolates) isolates resistant to amoxicillin was 12. 7% (beta-lactamase positive). Among Moraxella catarrhalis (159 isolates) isolates, only 8.2% were susceptible. Clavulanic acid restored the activity of amoxicillin against both species. Trimethoprim/sulfamethoxazole was active against only 59.5% of H. influenzae, while susceptibility to this compound among M. catarrhalis was 96.1%. All other compounds tested were active against>95% of H. influenzae and M. catarrhalis isolates. These species were susceptible to levofloxacin (MIC90 < or = 0.5 microg/mL for both) and gatifloxacin (MIC90 < or = 0.03 microg/mL for both) with very low MICs. Our results indicate that penicillin resistance rates are particularly high among pneumococci in some countries. The newer fluoroquinolones show an excellent potency and spectrum against pathogens causing community acquired respiratory infections in Latin America.
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PMID:Prevalence of antimicrobial resistance among respiratory tract isolates in Latin America: results from SENTRY antimicrobial surveillance program (1997-98). 1106 56

The incidence of lower respiratory tract infection (LRTI) in women of child-bearing age is approximately 64 per 1000 population. The spectrum of illness ranges from acute bronchitis, which is very common, through influenza virus infection and exacerbations of underlying lung disease, to pneumonia, which, fortunately is uncommon (<1.5% LRTI), but can be severe. Acute bronchitis is generally mild, self-limiting and usually does not require antibacterial therapy. Influenza virus infection in pregnant women has been recently related to increased hospitalization for acute cardiorespiratory conditions. At present, the safety of the newer neuraminidase inhibitors for the treatment of influenza virus infection has not been established in pregnancy and they are not routinely recommended. In influenza virus infection complicated by pneumonia, antibacterial agents active against Staphylococcus aureus and Streptococcus pneumoniae superinfection should be used. There are few data on infective complications of asthma or COPD in pregnancy. The latter is rare, as patients with COPD are usually male and aged over 45 years. Management is the same as for nonpregnant patients. The incidence and mortality of pneumonia in pregnancy is similar to that in nonpregnant patients. Infants born to pregnant patients with pneumonia have been found to be born earlier and weigh less than controls. Risk factors for the development of pneumonia include anemia, asthma and use of antepartum corticosteroids and tocolytic agents. Based on the few available studies, the main pathogens causing pneumonia are S. pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae and viruses. Beta-Lactam and macrolide antibiotics therefore remain the antibiotics of choice in terms of both pathogen coverage and safety in pregnancy. In HIV-infected pregnant patients, recurrent bacterial pneumonia, but not Pneumocystis carinii pneumonia (PCP), is more common than in nonpregnant patients. Trimethoprim/sulfamethoxazole (cotrimoxazole) has not definitely been associated with adverse clinical outcomes despite theoretical risks. Currently it is still the treatment of choice in PCP, where mortality remains high. In conclusion, there are few data specifically related to pregnant women with different types of LRTI. Where data are available, no significant differences compared with nonpregnant patients have been identified. In considering the use of any therapeutic agent or investigation in pregnant patients with LRTI, safety aspects must be carefully weighed against potential benefit. Otherwise, management strategies should not differ from those for nonpregnant patients. Further research in this area is warranted.
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PMID:Treatment of community-acquired lower respiratory tract infections during pregnancy. 1472 4

The GLOBAL (Global Landscape On Bactericidal Activity of Levofloxacin) Surveillance programme monitored antimicrobial susceptibility patterns of the key respiratory tract pathogens Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis collected in Brazil during 1997-1998, 1999-2000 and 2001-2002. Penicillin and azithromycin resistance among S. pneumoniae strains increased from 1997-1998, reaching 7.9% and 9.5%, respectively, in 2001-2002. Although decreasing by 4.9% since the previous study, trimethoprim-sulphamethoxazole resistance remained high at 33.7%. Concurrent resistance to penicillin, azithromycin and trimethoprim-sulphamethoxazole was seen in 2.9% of the S. pneumoniae isolates collected. Levofloxacin remained extremely active against S. pneumoniae, with 0.3% resistance reported in 1997-1998 and 0% resistance in 1999-2000 and 2001-2002. beta-Lactamase production in H. influenzae was > 10% in all three studies, with correspondingly high rates of ampicillin resistance. Trimethoprim-sulphamethoxazole was the least active agent tested against H. influenzae, with resistance rates of > 40% recorded in all three studies. All H. influenzae isolates were susceptible to cefuroxime, ceftriaxone, azithromycin and levofloxacin. Of the M. catarrhalis isolates, 98.0% in 1997-1998, 98.0% in 1999-2000 and 81.8% in 2001-2002 were beta-lactamase-positive. The continued high prevalence of antimicrobial resistance in Brazil underscores the importance of current surveillance initiatives. Levofloxacin, a fluoroquinolone prescribed widely for respiratory tract infections, continued to show potent activity against key respiratory pathogens.
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PMID:Antimicrobial susceptibility to levofloxacin and other antibacterial agents among common respiratory pathogens-a Brazilian perspective from the GLOBAL Surveillance Initiative 2001-2002. 1519 79


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