Three-year survey of amikacin use and aminoglycoside resistance in a general hospital in Belgium36631

The aim of the study was to evaluate the effect of intensive use of amikacin on the resistance levels to amikacin, gentamicin, tobramycin, netilmicin and dibekacin. The base-line resistance in the preamikacin phase (three months of amikacin use less than 1%; 676 isolates) was 1.0% for amikacin, 11.4% for gentamicin, 8.0% tobramycin, 6.2% for netilmicin and 8.3% for dibekacin. During the amikacin phase (36 months of average amikacin use of 89%; 6048 isolates) there was no significant change in aminoglycoside resistance except for dibekacin (from 8.3% to 10.9%, 0.05 greater than p greater than 0.02). Isolated amikacin resistance was not observed</p

The utility of the PCR method to study aacA gene heterogeneity in Serratia marcescens36656

NA</p

Comparative in vitro activity of cefepime and four extended-spectrum beta-lactams on 1,251 aminoglycoside-resistant gram-negative hospital strains36644

Cefepime was the most active compound on the Enterobacteriaceae with a MIC90 of 0.26 microgram/ml and a resistance rate of 0.1%. Ceftazidime was the most active drug on the non-fermenting bacilli (MIC90 9.65 micrograms/ml; resistance rate 3%). Amikacin- and gentamicin-resistant strains showed a decreased susceptibility to the beta-lactams, though the Enterobacteriaceae and the non-fermenters remained fairly sensitive to cefepime and ceftazidime, respectively. Aminoglycoside-3-N-acetyltransferase was the most prevalent enzyme and was often associated with intermediate resistance or resistance to beta-lactams. Non-fermenters showing aminoglycoside impermeability were very often intermediately resistant or resistant to beta-lactams</p

Aminoglycoside resistance in Gram-negative blood isolates from various hospitals in Belgium and the Grand Duchy of Luxembourg. Aminoglycoside Resistance Study Group36690

A total of 1102 consecutive clinical blood isolates, including 897 Enterobacteriaceae and 205 non-fermenting bacilli, were obtained from 13 university and university-affiliated hospitals, which were divided into a Northern and a Southern group. Resistance to gentamicin, tobramycin, netilmicin, amikacin and isepamicin was determined using a microdilution technique according to NCCLS procedures. The overall mean resistance level was 5.9% for gentamicin, 7.7% for tobramycin, 7.5% for netilmicin, 2.8% for amikacin and 1.2% for isepamicin. Resistance to amikacin and isepamicin was significantly higher in the Northern hospitals than in the Southern hospitals. In total, 157 isolates were found not to be susceptible to aminoglycosides. By PCR, 179 aminoglycoside resistance mechanisms, i.e. 150 genes encoding modifying enzymes and 29 permeability mechanisms, were detected in 148 isolates. A resistance mechanism could not be detected in nine isolates. Moreover, in a further 14 isolates the resistance profile was not fully explained by the detected genes. The aac(6&#039;)-I genes were found to be the most predominant resistance mechanism in both the Northern and Southern isolates, followed by aac(3) genes and permeability resistance. A total of 29 non-susceptible isolates harboured a combination of genes, 72.4% of which were a combination with the aac(6&#039;)-lb gene. The majority of these combinations were broad-spectrum combinations which represented 9.0% of the resistance mechanisms in non-susceptible Enterobacteriaceae and 19.3% in the non-fermenting bacilli</p

Antibacterial activity of enoxacin: comparison with aminoglycosides, beta-lactams and other antimicrobial agents36623

The activity of enoxacin, a new quinolone carboxylic acid, was evaluated against 3014 clinical isolates of Enterobacteriaceae, Pseudomonas and other non-fermenters and Staphylococcus aureus. Comparison was made with gentamicin, tobramycin, amikacin, netilmicin, ampicillin, piperacillin, carbenicillin, ticarcillin, ticarcillin plus clavulanic acid, trimethoprim, cotrimoxazole and erythromycin. In general enoxacin was the most active compound and resistance was only rarely encountered</p

Antibacterial activity of carumonam and cefpirome on hospital strains resistant to gentamicin and cephalothin: comparison with other beta-lactam antibiotics, new fluoroquinolones, aminoglycosides and other antibiotics

&lt;p&gt;The antibacterial in vitro activity of carumonam, a new monobactam, and cefpirome, a new cephalosporin, was studied on 483 hospital strains resistant to gentamicin and cephalothin, in comparison with amikacin, azlocillin, aztreonam, cefmenoxim, cefoperazone, cefotaxim, cefsulodin (for Pseudomonas), ceftazidime, ceftriaxone, cefuroxim, chloramphenicol, ciprofloxacin, doxycycline, enoxacin, netilmicin, norfloxacin, pefloxacin, piperacillin, rifampicin, tobramycin and trimethoprim. In general the two compounds have a very good in vito activity on Enterobacteriaceae but are less active on non-fermenting microorganisms. For the Enterobacteriaceae the minimal inhibitory concentrations 90% for carumonam was less than or equal to 1.1 mg/l excepted for Enterobacter spp. (43,6 mg/l) and M. morganii (56.8 mg/l) . All the Enterobacteriaceae are susceptible to cefpirome (minimal inhibitory concentrations 90% less than or equal to 5.3 mg/l). The activity of carumonam and cefpirome on Enterobacteriaceae is comparable with that of the third generation cephalosporins. Carumonam is more active than cefpirome and other beta-lactams, ceftazidime excepted, on Pseudomonas aeruginosa and Pseudomonas spp. On the other hand, both compounds reveal to have only a low activity on the other non-fermenters which minimal inhibitory concentrations 90% values of 115.4 mg/l for carumonam and 32.0 mg/l for cefpirome&lt;/p&gt;</p

Detection by polymerase chain reaction of genes encoding aminoglycoside-modifying enzymes in methicillin-resistant Staphylococcus aureus isolates of epidemic phage types. Belgian Study Group of Hospital Infections (GDEPIH/GOSPIZ)36655

The polymerase chain reaction (PCR) was used to identify the aacA-aphD, aphA3 and aadC genes, encoding the aminoglycoside-modifying enzymes AAC(6&#039;)-APH(2&quot;), APH(3&#039;)III and ANT(4&#039;4&quot;), respectively, and the methicillin resistance determinant mecA, in epidemic aminoglycoside and methicillin-resistant isolates of Staphylococcus aureus. In total, 37 isolates collected in the period 1980-1985 and 81 isolates from the period 1991-1992 were obtained from 10 different Belgian hospitals. Epidemic isolates from the earlier period were characterised by phage type C (6/47/54/75) of phage group III, whereas two other epidemic phage types of group III-types A (77) and B (47/54/75/77/84/85)--were commonest in isolates from the second period. The bifunctional AAC(6&#039;)-APH(2&quot;) was the enzyme encountered most frequently. The prevalence of APH(3&#039;)III decreased significantly in the 1991-1992 period, while ANT(4&#039;,4&quot;) was found solely in isolates from this period. Resistance mechanisms were more complex in isolates from the 1991-1992 period and the mecA gene was detected in all isolates. The PCR results corresponded well with those obtained in the radiochemical phosphocellulose paper binding assay. Isolates from the 1991-1992 period were shown to express significantly higher levels of acetyltransferase activity than isolates from the 1980s</p

The comparative activity of pefloxacin, enoxacin, ciprofloxacin and 13 other antimicrobial agents against enteropathogenic microorganisms36622

In this study, we compared the activity of pefloxacin, enoxacin and ciprofloxacin against 269 enteropathogenic strains (Campylobacter jejuni, enteropathogenic Escherichia coli, Salmonella typhi, Shigella spp., Vibrio cholerae and Yersinia enterocolitica) with that of rosoxacin, flumequin, nifuroxazide, erythromycin, chloramphenicol, ampicillin, cefotaxime, tetracycline, amikacin, netilmicin, sulfamethoxazole, trimethoprim and co-trimoxazole. Pefloxacin, enoxacin and ciprofloxacin were always among the most active compounds. Furthermore, resistant strains or strains with elevated MIC values were not found. The MIC90 value for these three compounds was less than or equal to 0.25 mg/l, except for C. jejuni where it was 0.3 mg/l and 1.4 mg/l for pefloxacin and enoxacin, respectively</p

Activity of cefotiam in combination with beta-lactam antibiotics on enterobacterial hospital strains36636

By using checkerboard titrations the effect of cefotiam combined with different beta-lactam antibiotics on fifty strains of Enterobacteriaceae moderately susceptible (minimal inhibiting concentration greater than or equal to 8 mg/l) or resistant (minimal inhibiting concentration greater than or equal to 64 mg/l) to cefotiam was evaluated. The following compounds were tested: cefamandole, cefazolin, cefmenoxime, cefotaxime, cefotiam, ceftazidime, cefuroxime, mecillinam and piperacillin. The synergistic effect varied markedly. The combination cefotiam-mecillinam showed the highest rate of synergistic activity. Antagonism was found in 1% of the combinations</p

Serotypes and extended spectrum beta-lactam resistance in aminoglycoside resistant Pseudomonas aeruginosa isolates from two Belgian general hospitals: a seven year study36650

A total of 1896 isolates of Pseudomonas aeruginosa resistant to aminoglycosides and isolated during the period 1983-1989 in two Belgian general hospitals were included in this study. The most frequently encountered O serotypes were O4, O11, O12 and non-typable isolates. The majority of the isolates showed resistance to extended spectrum beta-lactam antibiotics (cefotaxime, ceftriaxone and cefepime). However, a low degree of resistance was found for ceftazidime. By contrast, amikacin and isepamicin, remained active on a significant number of aminoglycoside resistant isolates. In both hospitals, impermeability and AAC(3)II enzyme production were the most prevalent aminoglycoside resistance mechanisms. There were marked differences between the two hospitals with regard to the distribution of the O-serotypes and resistance profiles</p