Antimicrobial activity of the crude ethanol extract fromPimenta pseudocaryophyllus

The chemical composition of essential oils from 15 aromatic medicinal plant species growing in the Democratic Republic of Congo have been studied. More than 15 constituents in an amount higher than 0.1% were identified in each essential oil. 1,8-cineole, alpha and beta-pinene, p-cymene, myrcene, gamma-terpinene, alpha-terpineol and limonene were prevalent constituents in almost more than 10 selected plant species. Results from the antibacterial testing by the diffusion method indicate that all essential oils (5 microl per disc) inhibited the growth of selected bacteria at different extents. The most active antibacterial essential oils were those of the leaves of Eucalyptus camadulensis and Eucalyptus terticornis (12-30 mm zone diameter of inhibition). They showed particularly a most potent inhibition of Pseudomonas aeruginosa growth (15-16 mm), followed by Eucalyptus robusta (12 mm). Essential oils from the leaves of Eucalyptus alba, Eucalyptus citriodora, Eucalyptus deglupta, Eucalyptus globulus, Eucalyptus saligna, Eucalyptus robusta, Aframomum stipulatum, Cymbopogon citratus, Ocimum americanum and that of the seeds of Monodora myristica showed also a good antibacterial activity (10-18 mm). Eucalyptus propinqua, Eucalyptus urophylla and Ocimum gratissimum essential oils were the less active samples against the selected bacteria. No correlation between the amount of major constituents such as 1,8-cineol, alpha-pinene, p-cymene, cryptone or thymol and the antibacterial activity was observed.

This study was conducted to evaluate the relationship between antimicrobial resistance and antimicrobial use in a university hospital in Taiwan. Disk susceptibility data of Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens, Proteus spp., Pseudomonas aeruginosa, Acinetobacter spp., Stenotrophomonas maltophilia and other non-fermentative Gram-negative bacilli causing nosocomial infections were evaluated. Data on annual patient-days and annual consumption (defined daily dose (DDD) per 1000 patient-days) of extended-spectrum cephalosporins (cefotaxime, ceftriaxone, ceftazidime, flumoxef, cefepime and cefpirome), β-lactam–β-lactamase inhibitor combinations (ticarcillin/clavulanic acid and piperacillin/tazobactam), carbapenems (imipenem and meropenem), aminoglycosides (amikacin, gentamicin and tobramycin), fluoroquinolones (ciprofloxacin (oral and injectable) and oral levofloxacin and moxifloxacin) from 1991 to 2003 were analysed. Increasing trends of incidences of several of these bacteria causing all nosocomial infections or nosocomial bloodstream infections were noted from 1991 to 2003. The annual patient-days of the hospital significantly increased, from 360 210 in 1991 to 672 676 in 2002 (linear regression analysis, P   0.72 (or <−0.72) and P-value < 0.05). Increased ciprofloxacin-resistant K. pneumoniae and meropenem-resistant Acinetobacter spp. was significantly associated with the increased usage of extended-spectrum cephalosporins but not with the other four classes of antibiotics. This 13-year study in a hospital demonstrated significant changes in antimicrobial use, which may have affected antimicrobial resistance in certain Gram-negative bacteria at the hospital.

Infection by Helicobacter pylori has been ascertained to be an important etiologic impetus leading usually to chronic active gastritis and gastric ulcer with growing incidences worldwide. Utilizing as the test pathogen a standard and five clinic strains of Helicobacter pylori, the antibacterial action was assessed in vitro with ethanol extracts of 30 Chinese herbal medicines which have been frequently prescribed since ancient times for treating gastritis-like disorders. Among the 30 tested materials, the ethanol extracts of Abrus cantoniensis (Fabaceae), Saussurea lappa (Asteraceae) and Eugenia caryophyllata (Myrtaceae) were strongly inhibitory to all test strains (MICs: approximately 40 microg/ml), and Hippophae rhamnoides (Elaeagnaceae), Fritillaria thunbergii (Liliaceae), Magnolia officinalis and Schisandra chinensis (Magnoliaceae), Corydalis yanhusuo (Papaveraceae), Citrus reticulata (Rutaceae), Bupleurum chinense and Ligusticum chuanxiong (Apiaceae) substantially active with MICs close to 60.0 microg/ml. As to antibacterial actions of the aqueous extracts of the same drugs, those derived from Cassia obtusifolia (Fabaceae), Fritillaria thunbergii and Eugenia caryophyllata were remarkably inhibitory against all the six Helicobacter pylori strains (MICs: approximately 60 microg/ml). The work compared almost quantitatively the magnitude of the anti-Helicobacter pylori actions of the 30 most prescribed gastritis-treating Chinese herbal drugs, and located as well some source plants where potent anti-Helicobacter pylori phytochemicals could be characterized.