In-vitro susceptibility of 1982 respiratory tract pathogens and 1921 urinary tract pathogens against 19 antimicrobial agents: a Canadian multicentre study. Canadian Antimicrobial Study Group.
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A total of 3903 pathogens from 48 Canadian medical centres were tested against 19 antimicrobial agents. Five agents showed activity against > or = 90% of all 1982 respiratory tract pathogens tested (ciprofloxacin, 90%; cefoperazone, 91%; ticarcillin/clavulanate, 92%; ceftazidime and imipenem, 93% each). Nine agents had > or = 90% activity against Enterobacteriaceae from respiratory tract infection (cefotaxime and ticarcillin/clavulanate, 90% each; aztreonam, ceftizoxime and ceftriaxone, 91% each; ceftazidime, 93%; ciprofloxacin, 97%; imipenem and netilmicin, 98% each). Similarly, five agents had activity against > or = 90% of all 1921 urinary tract pathogens tested (ciprofloxacin and ticarcillin/clavulanate, 90% each; cefoperazone and netilmicin, 91% each; imipenem, 99%). Nine agents had > or = 95% activity against Enterobacteriaceae from urinary tract infection (ciprofloxacin, 95%; cefotetan, 97%; aztreonam, cefotaxime, ceftazidime, ceftizoxime, ceftriaxone and netilmicin, 98% each; imipenem, 99%). Seventeen agents had activity against > or = 95% of Staphylococcus aureus strains. Susceptibility of Pseudomonas aeruginosa isolates ranged from 2% to 91%. (+info)
Markedly different rates and resistance profiles exhibited by seven commonly used and newer beta-lactams on the selection of resistant variants of Enterobacter cloacae.
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Seven beta-lactam antibiotics (cefepime, cefoperazone, ceftazidime, ceftriaxone, cefamandole, imipenem and meropenem) were tested for their potential to select resistance in standard and clinical strains of Enterobacter cloacae (n = 9). The strains were subcultured daily with the test antibiotics at doubling concentrations starting at 0.125 x MIC. Development of resistance throughout the passages was detected by a disc diffusion test. Ceftazidime, ceftriaxone and cefamandole selected resistance at a faster rate than cefoperazone, cefepime and meropenem. Imipenem did not select resistance in the nine strains tested and was the only antibiotic that eradicated all the strains during selection. The resistance patterns of strains selected by meropenem, cefepime and the other cephalosporins were markedly different, although cross-resistance to the early generation cephalosporins was common. The resistance phenotypes of most strains remained stable upon serial passages in antibiotic-free medium. The findings of this study highlight the importance of the choice of antibiotic for therapy not only on the basis of its antibacterial activity, but also on its potential to select resistance to itself and other antibiotics. (+info)
Investigation of the synergic effects of aminoglycoside-fluoroquinolone and third-generation cephalosporin combinations against clinical isolates of Pseudomonas spp.
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Antimicrobial synergy resulting from antibiotic combination therapy is often important in the treatment of serious bacterial infections. Previous studies have demonstrated synergy between an aminoglycoside and beta-lactam antibiotics in the treatment of Pseudomonas aeruginosa infections. The present paper investigates the synergic effects of aminoglycosides (amikacin and netilmicin) and fluoroquinolones (ciprofloxacin, ofloxacin and pefloxacin) in combination with third-generation cephalosporins (cefoperazone, ceftriaxone and ceftazidime) against 18 clinical isolates of Pseudomonas spp. The effects of these drugs were examined by three methods (disc diffusion, 'chequerboard' titration and the time-killing method), to evaluate the activities of the antibiotics alone and in combination against selected isolates. Fractional inhibitory concentration indices were calculated for all isolates with all combinations. Use of the disc diffusion method revealed that amikacin and netilmicin in combination with the three cephalosporins exhibited synergy against 7-12 isolates, whereas the combinations of quinolones and ceftazidime displayed synergic effects only in the case of 3-5 isolates. On 'chequerboard' titration, amikacin and ceftriaxone exerted synergy against seven of the isolates. The other combinations showed synergy against fewer isolates, but every combination demonstrated synergic effect against some of the isolates. The tested combinations had different effects against various Pseudomonas spp. With the time-killing method, the 1/2 x MIC of amikacin or ciprofloxacin in combination with the 1/2 x MIC of third-generation cephalosporins proved to be most effective. No antagonism was found with these combinations. Discrepancies in the detection of synergy were observed for the different methods. (+info)
Cefoperazone prevents the inactivation of alpha(1)-antitrypsin by activated neutrophils.
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At sites of neutrophilic inflammation, tissue injury by neutrophil elastase is favored by phagocyte-induced hypochlorous acid-dependent inactivation of the natural elastase inhibitor alpha(1)-antitrypsin. In the present study, cefoperazone prevented alpha(1)-antitrypsin inactivation by neutrophils and reduced the recovery of hypochlorous acid from these cells. Moreover, the antibiotic reduced the free elastase activity in a neutrophil suspension supplemented with alpha(1)-antitrypsin without affecting the cells' ability to release elastase. These data suggest that the drug inactivates hypochlorous acid before its reaction with alpha(1)-antitrypsin, thereby permitting the antiprotease-mediated blockade of released elastase. In conclusion, cefoperazone appears to have the potential for limiting elastase-antielastase imbalances, attenuating the related tissue injury at sites of inflammation. (+info)
Prevalence of Campylobacter, Arcobacter, Helicobacter, and Sutterella spp. in human fecal samples as estimated by a reevaluation of isolation methods for Campylobacters.
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The aims of this study were to investigate the prevalence of campylobacteria including Campylobacter jejuni subsp. jejuni (C. jejuni) and Campylobacter coli in human clinical samples and in samples from healthy individuals and to reevaluate the efficacies of conventional selective methods for isolation of Campylobacter spp. Two charcoal-based selective media, modified charcoal cefoperazone deoxycholate agar (mCCDA) and cefoperazone-amphotericin-teicoplanin (CAT) agar, were compared with Skirrow's blood-based medium and with a filter method (filter) applied to a yeast-enriched blood agar. A total of 1,376 specimens were tested on all four media, and the percentages of thermophilic Campylobacter-positive specimens isolated on Skirrow's medium, filters, CAT agar, and mCCDA were 82, 83, 85, and 95%, respectively. When additional samples were processed with the three selective media, mCCDA recovered significantly more thermophilic Campylobacter spp. than Skirrow's medium (P = 0.0034). No significant difference between Skirrow's medium and CAT agar was observed in this study. Another six taxa were identified, namely, Campylobacter concisus, Campylobacter curvus-like bacteria, Arcobacter butzleri, Arcobacter cryaerophilus, Helicobacter cinaedi, and Sutterella wadsworthensis. Most of these strains were isolated after 5 to 6 days of incubation by use of the filter technique. This paper provides evidence for the existence of S. wadsworthensis in human feces from clinical cases of gastrointestinal disorders and in feces from a healthy individual. Furthermore, C. concisus was isolated from a large number of diarrheal cases, particularly those at the extremes of age, but was additionally isolated from the feces of healthy people. Further investigations to establish the role of C. concisus and S. wadsworthensis in enteric disease is needed. We conclude that a range of campylobacteria may cause infections in Denmark. (+info)
A 74-year-old man was admitted to our hospital with frequent right flank pain. The multiple multilocular hepatic abscesses were revealed by computed tomography. Radiographs following a barium meal showed a linear filling defect in the ileum consistent with ascariasis. One day after treatment with pyrantel pamoate, an Ascaris was passed in the stool. The pyogenic hepatic abscesses gradually healed with both antibiotics and continuous drainage. After 2 months, he was discharged. In this case, the pyogenic hepatic abscesses were thus considered to have been caused by an inflammation which spread through the portal vein. (+info)
Susceptibility of clinical isolates of Bacteroides fragilis group strains to cefoxitin, cefoperazone and ticarcillin/clavulanate.
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A total of 40 strains of the B. fragilis group was isolated from clinical specimens in two hospital centers in Fortaleza from 1993 to 1997. The most frequently isolated species was Bacteroides fragilis (19 strains) and most isolates came from intra-abdominal and wound infections. The susceptibility profile was traced for cefoxitin, cefoperazone and ticarcillin-clavulanate by using the agar dilution reference method. All isolates were susceptible to ticarcillin-clavulanate (128/2 microg/ml). Resistance rates of 15 and 70% were detected to cefoxitin (64 microg/ml) and cefoperazone (64 microg/ml), respectively. Such regional results permit a better orientation in choosing this group of antibiotics for prophylaxis and therapy especially in relation to cefoxitin, which is frequently used in the hospital centers studied. (+info)
In-vitro susceptibility of Burkholderia pseudomallei to cefoperazone-sulbactam combination.
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Melioidosis is endemic in Malaysia. Emerging resistance with new and current antimicrobial agents has underscored the need to look further for new antimicrobial agents for the treatment of melioidosis. Hence, we evaluated the in-vitro susceptibility of fifty locally isolated strains of Burkholderia pseudomallei, the causative agent of melioidosis to cefoperazone-sulbactam combination using the method of NCCLS. All the fifty strains tested were susceptible in-vitro to cefoperazone-sulbactam. The MIC90 of the organism for cefoperazone-sulbactam was 4 mg/L. The results of our findings suggested that cefoperazone-sulbactam may be useful in the treatment of melioidosis. (+info)