Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004610 (bacteremia)
 13,199 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

One hundred eighty-six clinical isolates of Haemophilus influenzae (H. influenzae) collected from January 1996 through December 1997 from 182 pediatric patients and 16 isolates from blood or cerebrospinal fluid (CSF) of 13 patients with bacteremia and purulent meningitis collected during the last ten years were examined for in vitro susceptibilities to 23 antibiotic agents, including 3 penicillins, 9 cephalosporins, 4 carbapenems and others, as well as for their encapsulated types and beta-lactamase production. Ceftriaxone (a third generation cephalosporin) had the highest activity against the strains in this study (minimal inhibitory concentration, MIC90 of 0.025 microgram/ml) and cefditoren (a new oral cephalosporin) was the most active oral antimicrobial agent (MIC90 of 0.05 microgram/ml). Meropenem had a much higher activity against H. influenzae (MIC90 of 0.2 microgram/ml) than the other carbapenems (imipenem, MIC90 of 1.56 micrograms/ml, panipenem, MIC90 of 1.56 micrograms/ml, and biapenem, MIC90 of 3.13 micrograms/ml). Regarding the serotyping of the encapsulated strains, 172 strains (85.1%) were nontypeable and 30 (14.9%) were serotyped (24 strains of type b, 4 strains of type e, one each of type a and c). Fifteen of the strains isolated from blood and CSF were type b and one was nontypeable. Sixteen of 202 strains (7.9%) produced beta-lactamase and all of them produced both penicillinase and cephalosporinase. The production of beta-lactamase in this study was lower than that reported in previous studies [1-3]. In this study, some strains were found against which the MICs of carbapenems were very high (highest MIC of imipenem was 12.5 micrograms/ml, of panipenem was 6.25 micrograms/ml and of biapenem was 25 micrograms/ml). Therefore, we assayed the binding affinities of imipenem for each of penicillin-binding proteins (PBPs) about one of these resistant strains. In resistant strains, inhibitory concentrations (IC50) of imipenem for PBP4 and 5 were much higher than those in susceptible strains. Thus, the results demonstrate the decrease of the affinity of imipenem for PBP4 and 5. It seems, therefore, that the major factor in the resistance to imipenem of H. influenzae was the low affinity of PBP4 and 5 for the drug.
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PMID:In vitro susceptibilities to 23 antimicrobial agents of Haemophilus influenzae from pediatric patients in Japan. 1105 21

The in vitro activities of the ketolide telithromycin and eight other antibiotics were tested against 77 strains of viridans group streptococci isolated from blood samples of neutropenic patients. Thirty-one (40.3%) of the strains were resistant to penicillin G, and 27 (35.1%) were resistant to erythromycin A. Telithromycin (MIC range of < or =0.03 to 1 microg/ml) was the most active antimicrobial tested. These data suggest that telithromycin could be useful for treatment of viridans group streptococcal bacteremia in neutropenic patients with cancer.
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PMID:In vitro activities of the new ketolide HMR 3647 (telithromycin) in comparison with those of eight other antibiotics against viridans group Streptococci isolated from blood of neutropenic patients with cancer. 1115 68

Community-acquired oxacillin-resistant Staphylococcus aureus (ORSA) infections are an emerging problem in the 1990s in Sydney, Australia. Laboratory data pertaining to all specimens that grew S. aureus between 1/1/1990 and 31/12/1999 were analysed. A total of 12,909 isolates of S. aureus were obtained. The proportions that were nonmultiresistant oxacillin-resistant S. aureus (NORSA) increased from 0.09% in 1990 to 5.5% in 1999. Resistance of NORSA strains to erythromycin was 8.5%, ciprofloxacin 8.4%, tetracycline 13%, rifampicin 0.7%, and fusidic acid 5.3%. A chart review was performed for cases of NORSA infection which occurred 1/1/1998-3/5/1998. Isolates from these cases underwent E-test oxacillin MIC testing, mecA determinant PCR, phage typing and pulsed-field gel electrophoresis. All nine of the patients with NORSA were Polynesians, and all had serious soft tissue infections. Bacteraemia was not seen. Only one patient received vancomycin yet all recovered. Isolates from all nine patients contained the mecA determinant. Oxacillin MICs were 1-8 mg/l. Strain differentiation with phage typing and pulsed-field gel electrophoresis showed isolates from eight patients were closely related and were similar to New Zealand WSPP1 and WSPP2 strains. Medical practitioners should take specimens for culture and sensitivity from lesions where infection with S. aureus is likely. Empirical treatment of staphylococcal infections in Polynesians needs to cover NORSA. Methods to detect oxacillin resistance need to be robust.
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PMID:Community-acquired, non-multiresistant oxacillin-resistant Staphylococcus aureus (NORSA) in South Western Sydney. 1135 55

Continuous infusion (CI) of ceftazidime has been demonstrated to add clinical advantages in the treatment of infection of neutropenic cancer patients, especially in the presence of gram-negative bacteremia. However, this particular administration route is not always feasible in this particular clinical setting because of the patient's need of additional care or drug administration. The aim of this study was to evaluate, through a computer-assisted simulation, the modifications of drug concentration in presence of a single or repeated 2-hour interruptions of CI ceftazidime in critically ill patients. Our analysis shows that a loading dose of 20 mg/kg, followed by a CI of 100/mg/kg/die, should be able to maintain efficacious plasma concentrations in all subjects, even when it is interrupted for a 2-hour period every 8 hours. Plasma concentrations after interruption should not fall below 8 microg/mL and for about 65-80% of time should reach levels equal to 5 times the MIC of the infecting pathogen. A 2-hour interruption of CI ceftazidime up to 3 times a day is likely to represent a safe and efficacious administration regimen that may enhance the management of the treatment of infectious complications in critically ill patients such as neutropenic cancer patients.
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PMID:Temporary interruption of ceftazidime continuous infusion without reduction of activity: a computer-assisted simulation. 1158 82

Clinicians caring for patients with vancomycin-resistant Enterococcus faecium (VREF) infections face severe constraints in the selection of treatment. Quinupristin/dalfopristin (Synercid) is active in vitro against VREF, with a MIC(90) of 1.0 microg/mL. We investigated the clinical efficacy and safety of this agent in a multicenter, prospective, noncomparative, emergency-use study of 396 patients. Patients were included if they had signs and symptoms of active infection, including bacteremia of unknown origin, intra-abdominal infection, and skin and skin-structure infection, with no alternative antibiotic therapy available. The mean duration of treatment was 20 days (range, 4-40 days). The clinical response rate was 68.8% in the evaluable subset, and the overall response rate was 65.6%. The most common adverse events related to quinupristin/dalfopristin were arthralgias and myalgias. Related laboratory abnormalities were rare. In this severely ill patient population, quinupristin/dalfopristin was efficacious and demonstrated an acceptable safety profile in the treatment of VREF infection.
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PMID:Treatment of vancomycin-resistant Enterococcus faecium infections with quinupristin/dalfopristin. 1166 30

Linezolid is a new oxazolidinone antibiotic with potent activity against gram-positive bacteria, including Streptococcus pneumoniae. The pharmacodynamic activity and in vivo efficacy of linezolid were compared to those of ceftriaxone in an immunocompetent rat model of pneumococcal pneumonia. Rats infected intratracheally with 8 x 10(7) CFU of a penicillin-sensitive (MIC, 0.032 microg/ml) strain of S. pneumoniae were treated for 5 days beginning 18 h postinfection. Groups of rats were sham treated with oral phosphate-buffered saline or received oral liquid linezolid at 25 or 50 mg/kg of body weight twice a day (b.i.d.) or subcutaneous ceftriaxone at 100 mg/kg once daily. Mortality was monitored for 10 days postinfection; blood culturing was performed on day 1 (pretreatment) and on days 3, 5, and 10 postinfection for the determination of bacteremia. Serum also was collected for the determination of pharmacokinetic and pharmacodynamic parameters at 30 min and at 3, 5, and 12 h (linezolid) or 3, 5, and 24 h (ceftriaxone) postdose. The cumulative mortality rates were 100% for the sham-treated group, 58.3% for the low-dose linezolid group, 8.3% for the high-dose linezolid group, and 0% for the ceftriaxone group. Rats in each of the antibiotic treatment groups had significantly fewer bacteria (P < 0.00001) in their bronchoalveolar lavage fluid (BALF) on day 3 postinfection than sham-treated rats. There also were significantly fewer organisms in the BALF of rats treated with ceftriaxone than in the BALF of rats treated with either dose of linezolid. Oral linezolid at 50 mg/kg b.i.d. therefore was as effective as ceftriaxone in experimental pneumococcal pneumonia, whereas the 25-mg/kg b.i.d. dose was significantly less effective. All pharmacodynamic parameters reflected efficacy and were significantly different for the two dosage regimens of linezolid (P < 0.01). However, the free-fraction pharmacodynamic parameters predictive of outcome were a value of >39% for the percentage of time in the experimental dosing interval during which the linezolid concentration exceeded the MIC and a value of >147 for the ratio of the area under the serum concentration-time curve to the MIC.
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PMID:Pharmacodynamic activity and efficacy of linezolid in a rat model of pneumococcal pneumonia. 1195 67

From January 1999 to May 2000 (17 months), 21 strains of streptococci and four strains of enterococci have been isolated from 74 blood cultures in 25 infectious episodes in hematologic patients. They concerned 21 patients, of 21 to 77 years old. These patients suffered from acute leukaemia (14 cases), chronic lymphoid leukaemia (two cases), non-Hodgkin's lymphoma (two cases) or myeloma (three cases). Seventeen patients displayed a single streptococcal or enterococcal episode, two had two episodes in the course of a single stay in the hospital, two others in the course of two different stays. During 16 episodes (64%), the bacteremia occurred within 15 days after the onset of neutropenia consecutive to antimitotic chemotherapy, and in nine episodes (36%) it has occurred after a period exceeding 15 days. In six cases the patients had already received antibiotics with a large antibacterial activity (beta-lactam, fluoroquinolone and/or glycopeptide +/- aminoside) and in four cases a single antibiotic (synergistine or cotrimoxazole). Most streptococci (20/21) were oral streptococci (ten Streptococcus mitis, five S. oralis, two S. sanguis, three S. pneumoniae). A single strain of beta-hemolytic streptococci has been identified as S. dysgalactiae subsp. equisimilis. The enterococci were one strain of Enterococcus faecalis and three E. faecium. Ten streptococci were susceptible to 0.25 mg/L of penicillin G, ten were less susceptible (0.5 < or = MIC < 32 mg/L), and a strain was resistant (MIC = 32 mg/L). Eighteen strains were susceptible to amoxicillin and cefotaxime. For three strains, the MICs of amoxicillin and cefotaxime (8-16 mg/L and 8-32 mg/L, respectively) were higher. Levels of resistance of the enterococci to the beta-lactam (penicillin, amoxicillin, and piperacillin) were variable. All species were susceptible to glycopeptides. Three patients were transferred in intensive care unit for respiratory distress or shock syndrome. Their evolution has remained severe under antibiotherapy comprising beta-lactam or vancomycin associated with an aminoside. This results demonstrate the interest of species identification to adapt the antibiotic treatment and confirms the frequency of oral streptococci in severe bacteremia in neutropenic patients.
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PMID:[Therapeutic impact of streptococcal and enterococcal bacteremia in hematology patients]. 1198 Mar 30

The treatment of life-threatening infections due to carbapenem-resistant Acinetobacter baumannii has become a serious challenge for physicians worldwide. Often, only colistin shows in general good in vitro activity against these carbapenem-resistant strains, but its antibacterial efficacy in comparison with the antibiotics most used in clinical practice is not well known. We studied the efficacy of colistin versus those of imipenem, sulbactam, tobramycin, and rifampin in an experimental pneumonia model with immunocompetent mice. We used three strains of A. baumannii corresponding to the main clones (A, D, and E) involved in the outbreaks of our hospital, with different grades of resistance to imipenem (imipenem MICs of 1, 8, and 512 microg/ml, respectively) and to the other antibiotics. The MIC of colistin was 0.5 microg/ml for the three strains. Reduction of log(10) CFU/g in lung bacterial counts, clearance of bacteremia, and survival versus results with controls were used as parameters of efficacy. Imipenem and sulbactam (Deltalung counts: -5.38 and -4.64 log(10) CFU/ml) showed the highest level of bactericidal efficacy in infections by susceptible and even intermediate strains. Tobramycin and rifampin (-4.16 and -5.15 log(10) CFU/ml) provided good results against intermediate or moderately resistant strains, in agreement with killing curves and pharmacodynamics. On the contrary, colistin showed the weakest antibacterial effect among the antibiotics tested, both in killing curves and in the in vivo model (-2.39 log(10) CFU/ml; P < 0.05). We conclude that colistin did not appear as a good option for treatment of patients with pneumonia due to carbapenem-resistant A. baumannii strains. Other alternatives, including combinations with rifampin, may offer better therapeutic profiles and thus should be studied.
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PMID:Efficacy of colistin versus beta-lactams, aminoglycosides, and rifampin as monotherapy in a mouse model of pneumonia caused by multiresistant Acinetobacter baumannii. 1201 13

In a previous study in experimental Klebsiella pneumoniae pneumonia, the therapeutic potential of ciprofloxacin was significantly improved by encapsulation in polyethylene glycol-coated ("pegylated") long-circulating (STEALTH) liposomes. Pegylated liposomal ciprofloxacin in high doses was nontoxic and resulted in relatively high and sustained ciprofloxacin concentrations in blood and tissues, and hence an increase in the area under the plasma concentration-time curve (AUC). These data correspond to data from animal and clinical studies showing that for fluoroquinolones the AUC/MIC ratio is associated with favorable outcome in serious infections. Clinical failures and the development of resistance are observed for marginally susceptible organisms like Pseudomonas aeruginosa and for which sufficient AUC/MIC ratios cannot be achieved. In the present study the therapeutic efficacy of pegylated liposomal ciprofloxacin was investigated in two rat models of Pseudomonas aeruginosa pneumonia. In the acute model pneumonia developed progressively, resulting in a rapid onset of septicemia and a high mortality rate. Ciprofloxacin twice daily for 7 days was not effective at doses at or below the maximum tolerated dose (MTD). However, pegylated liposomal ciprofloxacin either at high dosage or given at low dosage in combination with free ciprofloxacin on the first day of treatment was fully effective (100% survival). Obviously, prolonged concentrations of ciprofloxacin in blood prevented death of the animals due to early-stage septicemia in this acute infection. However, bacterial eradication from the left lung was not effected. In the chronic model, pneumonia was characterized by bacterial persistence in the lung without bacteremia, and no signs of morbidity or mortality were observed. Ciprofloxacin administered for 7 days at the MTD twice daily resulted in killing of more than 99% of bacteria in the lung; this result can also be achieved with pegylated liposomal ciprofloxacin given once daily. Complete bacterial eradication is never observed.
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PMID:Ciprofloxacin in polyethylene glycol-coated liposomes: efficacy in rat models of acute or chronic Pseudomonas aeruginosa infection. 1212 35

Epidemiological characteristics of ampicillin-resistant, vancomycin-susceptible Enterococcus faecium are not well known. Recently, these strains have been proposed as the substratum for the later appearance of vancomycin-resistant E. faecium. To analyse this problem, the medical charts of patients with bacteraemia caused by E. faecium diagnosed in our institution during a 6 year period (1994-1999) were reviewed. Demographic data, clinical characteristics, antibiotic exposure and outcome were compared among patients with ampicillin-resistant (MIC > 16 mg/L, NCCLS criteria) and ampicillin-susceptible strains. Clonality between different strains was analysed by pulsed-field gel electrophoresis (PFGE). We evaluated 49 cases of E. faecium bacteraemia; 29 patients with ampicillin-resistant strains and 20 patients with -susceptible strains were identified. By logistic regression analysis, only previous administration of beta-lactams (OR: 6.3; 95% CI: 1.12-20.0) and urinary catheterization (OR:4.2; 95% CI: 1.3-30.0) were identified as predictors of ampicillin resistance in enterococcal bacteraemic patients. An elevated APACHE II score was the only independent factor associated with mortality in enterococcal bacteraemia (OR:13.5; 95% CI: 1.04-175.4). PFGE analysis revealed a strong association between specific ampicillin-resistant clones and the location of patients during hospitalization, suggesting nosocomial transmission. Bacteraemia caused by ampicillin-resistant enterococci was not associated with increased mortality when compared with bacteraemias caused by ampicillin-susceptible strains.
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PMID:Risk factors associated with ampicillin resistance in patients with bacteraemia caused by Enterococcus faecium. 1246 Oct 24


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