COMPARISON OF IMIPENEM AND 5 OTHER ANTIPSEUDOMONAL AGENTS AGAINST GENTAMICIN-SUSCEPTIBLE AND GENTAMICIN-RESISTANT PSEUDOMONAS-AERUGINOSA

The in vitro activities of imipenem, aztreonam, piperacillin, ciprofloxacin and amikacin were tested by the microbroth dilution technique against 86 clinical isolates of Pseudomonas aeruginosa. Imipenem and ciprofloxacin were the most active agents against gentamicin-susceptible P. aeruginosa. Only imipenem inhibited gentamicin-resistant P. aeruginosa at less than or equal to 8 mu g/ml. The finding that none of the gentamicin-resistant strains were resistant to imipenem and amikacin indicated the superiority of these antibiotics to the other agents in hospital-associated gentamicin-resistant P. aeruginosa infections

POSTANTIBIOTIC EFFECT OF IMIPENEM, ALONE AND IN COMBINATION WITH AMIKACIN, ON PSEUDOMONAS-AERUGINOSA

Imipenem and amikacin, alone and in combination, were investigated for their postantibiotic effect (PAE) on Pseudomonas aeruginosa. Four clinical strains of P. aeruginosa in the logarithmic phase of growth were exposed for 1 h to antibiotics, alone and in combination. Recovery periods of test cultures were evaluated after dilution using viable counting. Imipenem produced a PAE ranging from 0.7 to 1.55 h. Similar PAEs were induced by amikacin (ranging from 0.65 to 2 h). In combination, imipenem and amikacin produced as a final PAE (ranging from 1.6 to 2.65 h), a rough mathematical sum of the individual effects. The finding of this study may have important implications far the timing of doses during therapy with antimicrobial combinations

Synthesis and antimicrobial activity of 4-carbethoxymethyl-2-[(alpha-haloacyl)amino]thiazoles and 5-nonsubstituted/substituted 2-[(4-carbethoxymethylthiazol-2-yl)imino]-4-thiazolidinones

4-Carbethoxymethyl-2-[chloroacetyl / alpha-chloropropionyl / alpha-bromobutyryl/ alpha-chloro-(alpha-phenylacetyl)amino]thiazoles (I-IV) were synthesized by reacting 4-carbethoxymethyl-2-aminothiazole with chloroacetyl chloride, alpha-chloropropionyl chloride, alpha-bromobutyryl bromide and alpha-chloro-alpha-phenylacetyl chloride, respectively. Furthermore, I-IV were refluxed with ammonium thiocyanate to give 2-[(4-carbethoxymethylthiazol-2-yl)imino] (VIII). V was refluxed with various aromatic aldehydes to give 5-arylidene-2-[(4-carbethoxymethylthiazol-2-yl)imino]-3-thiazolidinones (IX-XIV). The structures of synthesized compounds were confirmed by elemental analyses, hydrolysis, UV, IR,H-1-NMR and EI mass spectral data. The antimicrobial activities of the compounds were assessed by microbroth dilution technique using Mueller-Hinton broth and Mueller-Hinton Agar. In this study, Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 1539, Salmonella typhi, Shigella flexneri, Proteus mirabilis and Candida albicans ATCC 10231 were used as test microorganisms. Among the tested compounds, XI and XIV showed activity against S. aureus (MIC: 78 mu g/ml, 1.6 mu g/ml), whereas compound V had an activity against S. flexneri (MIC: 39 mu g/ml) and compound I against C. albicans (MIC: 125 mu g/ml). Compounds I, IV-XIV were also evaluated for antituberculosis activity against Mycobacterium tuberculosis H37Rv using the BACTEC 460 radiometric system and BACTEC 12B medium. Only compounds I and XIV showed 86 % and 67 % inhibition in the primary screen

STUDIES ON AZOPYRAZOLE DERIVATIVES .9. SYNTHESIS AND ANTIBACTERIAL EVALUATION OF NOVEL PHENYLHYDRAZONES AND THEIR SUBSTITUTED 4-ARYLAZOPYRAZOLE DERIVATIVES

6-Methyl-2,4-heptandione (1) was coupled with diazonium salts of sulfanilamide (2) and 4-aminobenzoic acid (3). Resulting new hydrazones, namely 4-methyl-2-oxovaleraldehyde p-substituted phenylhydrazones 4 and 5, were refluxed with various hydrazines to synthesize the title compounds 6-15. Their structure elucidation was made on the basis of their analytical and spectroscopic data. The antibacterial activity was evaluated. Some of the compounds tested exerted moderate to potent antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus pyogenes

Antimicrobial activity of Zn-II, Cd-II, and Hg-II complexes of 1,2-Bis-[2-(5-R)-1H-benzimidazolyl]-1,2-ethanediols and 1,4-Bis-[2-(5-R)-1H-benzimidazolyl]-1,2,3,4-butanetetraols

1,2-Bis-[2-(5-H/Me/Cl/NO2)-1H-benzimidazolyl]-1,2-ethanediols(L-1-L-4), 1,4-bis-[2-(5-H/Me/Cl)-1H-benzimidazolyl]-1,2,3,4-butanetetraols (L-5-L-7) and their complexes with ZnCl2, CdCl2 and HgCl2 were synthesized and antibacterial activity of the compounds was tested toward Slaphylococcus aureus, S. epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri, Proteus mirabilis and antifungal activity against Candida albicans. Hg-II complexes have a considerably higher antimicrobial activity against all microorganisms. Some Hg-II complexes show higher antifungal activity than clotrimazole toward C. albicans. Zn-2(L-3)Cl-4, Zn-2(L-4)Cl-4, and Cd(L-3)Cl-2 were moderately effective against S. aureus and S. epidermidis; Cd(L-4)Cl-2 exhibited a weak activity only against S. epidermidis

Synthesis and evaluation of antibacterial activity of some 2-[[alpha-(4-substituted benzoyloxy)-alpha-phenylacetyl or methylacetyl]amino]-5-(4-methoxyphenyl)-1,3,4-oxadiazoles

In this study, a new series of 2-[[alpha-(4-substitutedbenzoyloxy)-alpha-phenylacetyl or methylacetyl]amino]-5-(4-methoxyphenyl)-1,3,4-oxadiazoles were obtained by condensation of 2-[(alpha-chloro-alpha-phenylacetyl or alpha-bromopropionyl)amino]-5-(4-methoxyphenyl)1,3,4-oxadiazoles with sodium salts of 4-substituted benzoic acids. Structures of the compounds were assigned on the basis of spectral data (UV, IR, H-1 NMR, EI MS) and elemental analyses. The antibacterial activities of the novel compounds against Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 1539, Salmonella typhi, Shigella flexneri and Proteus mirabilis and antifungal activity against Candida albicans ATCC 10231 were tested using disk diffusion method. Compounds 4a, 4d and 4g were found to be active against S. aureus ATCC 6538 (MIC, 78, 39 and 78 mug ml(-1), respectively) and compound 4e against S. epidermidis ATCC 12228 (MIC, 156 mug ml(-1)). (C) 2001 Elsevier Science S.A. All rights reserved