New Antibacterial Drugs Research Articles

Research progress on antibacterial flavonoids

Bacterial resistance is an increasingly serious problem. Therefore, it is necessary to find new antibacterial drugs. Flavonoids are a class of polyphenolic chemicals with low molecular weight, which exhibit many beneficial properties for human health by the interaction of cellular targets, such as the key cell signaling pathways. Flavonoids have been extensively studied as one of the important sources of antimicrobial compounds. At present, antibacterial flavonoids can be divided into two categories. One is the natural, extracted from the plant or microbial secondary metabolites. The other is the product of chemical synthesis, i.e. the derivatives of flavonoids or chalcone. In this paper, the progress of antibacterial flavonoids by natural extraction and chemical synthesis were summarized. Key words: Flavononids; Antibacterial; Natural extraction; Chemical synthesis

Pathogenesis and adjuvant therapy for pneumococcal meningitis

Pneumococcal meningitis is one of the most common infectious diseases of the central nervous system in pediatric period which is characterized by acute fever, unconvulsions, consciousness, increased intracranial pressure and meningeal irritation and cerebrospinal fluid pus changes in clinic.With the advent of antibiotics and pneumococcal vaccination, the morbidity and mortality of the disease decline significantly.But due to the appearance of drug-resistant bacteria and the relative lag of research and development speed of clinical new antibacterial drugs, it still has high mortality and morbidity which are promoting researches of pathogenesis and adjuvant therapy.In this paper, researches of pathogenesis and adjuvant therapy for preumococcal meningitis were reviewed in recent years. Key words: Streptoccus pneumoniae; Meningitis; Adjuvant therapy,

Isolation and identification of bioactive compounds responsible for the anti-bacterial efficacy of Lotus corniculatus var. São Gabriel.

Lotus corniculatus (Fabaceae) is considered a forage plant utilized as food for ruminants in the south of Brazil. This herb is also actually used to treat intestinal infection in these animals. In our experiments, we evaluated the anti-bacterial activity of crude extract from L. corniculatus var. Sao Gabriel were assayed against Gram-positive and Gram-negative bacterium. The crude extracted did not show any anti-bacterial activity, but the hexane fraction did on Bacillus cereus (MIC=100 μg/mL) and on Enterococcus faecalis, Listeria monocytogenes, Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter calcoaceticus, and Providencia alcalifaciens (MIC=600, 800 or 1000 μg/mL). The Ethyl acetate fraction (AcOEt) also showed important anti-bacterial activity on Bacillus cereus, E. faecalis, and Acinetobacter calcoaceticus (MIC=800 μg/mL). The oleanolic acid isolated from hexane fraction showed the same effect on Staphylococcus aureus methycillin-resistant (MIC=100 μg/mL), L. monocytogenes (MIC=25 μg/mL), and Bacillus cereus (MIC=25 μg/mL). Further, Kaempferitrin isolated from ethyl acetate fraction has also shown anti-bacterial activity on Shighella flexinerii (MIC=100 μg/mL), Salmonella typhimurium (MIC=100 μg/mL), A. calcoaceticus (MIC=100 μg/mL), E. faecalis (MIC=3.9 μg/mL), and Bacillus cereus (MIC=8.5 μg/mL). This study suggests that L. corniculatus var. Sao Gabriel have potential pharmacological property for a new anti-bacterial drug development. Key words: Anti-bacterial activity, Kaempferitrin, Lotus corniculatus, Oleanolic acid, β-sitosterol.

X-ray structure of HI0817 from Haemophilus influenzae: protein of unknown function with a novel fold.

The enormous amount of sequence data isbeing derived from 160 completed genomes (http://www.cbs.dtu.dk/services/GenomeAtlas/index.php) andfrom over 170 genome sequencing projects in progress(http://www.ncbi.nlm.nih.gov/genomes/MICROBES/InProgress.html). For many protein sequences, which areannotated as “hypothetical proteins,” neither a functionnor a three-dimensional structure is available. The deter-mination of the structures and functions of these proteinsoffer the basis for important discoveries such as newantibacterial drug targets and a better understanding ofcellularprocesses.OurexperiencewithStructuralGenom-ics of 43 such proteins reveals an enrichment of novel foldscompared with the general set of proteins entering theProtein Data Bank (PDB).As of this writing, the

Antibiotic susceptibility of blood and cerebrospinal fluid isolates of Haemophilus influenzae.

One hundred and sixty-nine blood and cerebrospinal fluid isolates of Haemophilus influenzae, collected in the Province of Ontario from children and adults from 1976 to 1983, were tested for susceptibility to six conventional and eight newer antibacterial drugs. Most active were ceftriaxone, ceftizoxime and cefotaxime (MIC90 less than or equal to 0.02 mg/l); latamoxef (moxalactam), acrosoxacin and ceftazidime were close behind with MIC90s in the 0.05-0.09 mg/l range. Twenty-five strains (14.8%) were beta-lactamase-producing and thus resistant to ampicillin. There were no chloramphenicol-resistant strains. The isolates showed intermediate but still clinically useful susceptibility to trimethoprim, rifampicin, cefuroxime, piperacillin and chloramphenicol and were least susceptible to gentamicin and sulphamethoxazole.