Novel Anti-Infective Compounds from Marine Bacteria

Abstract

As a result of the continuous evolution of microbial pathogens towards antibiotic-resistance, there have been demands for the development of new and effective antimicrobial compounds. Since the 1960s, the scientific literature has accumulated many publications about novel pharmaceutical compounds produced by a diverse range of marine bacteria. Indeed, marine micro-organisms continue to be a productive and successful focus for natural products research, with many newly isolated compounds possessing potentially valuable pharmacological activities. In this regard, the marine environment will undoubtedly prove to be an increasingly important source of novel antimicrobial metabolites, and selective or targeted approaches are already enabling the recovery of a significant number of antibiotic-producing micro-organisms. The aim of this review is to consider advances made in the discovery of new secondary metabolites derived from marine bacteria, and in particular those effective against the so called “superbugs”, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin resistant enterococci (VRE), which are largely responsible for the increase in numbers of hospital acquired, i.e., nosocomial, infections.

Hemolysin, Protease, and EPS Producing PathogenicAeromonas hydrophilaStrain An4 Shows Antibacterial Activity against Marine Bacterial Fish Pathogens

“…One way to prevent antibiotic resistance is by using new compounds which are not based on existing synthetic antimicrobial compounds. GC-MS analysis of crude ethyl acetate cell extract of Aeromonas hydrophila strain An4 clearly demonstrated the presence of several important organic metabolites which are known antagonist to bacteria, viruses, and fungi [9,12,36,39,40]. It is interesting to note that even pathogenic strains can be used as biocontrol agents against other pathogens due to inherent presence of various virulence factors, namely hemolysin, proteases, and EPS along with several antibacterial organic compounds.Thus antibacterial metabolites synthesized by the test organism may serve as valuable drugs to control pathogenic bacterial strains causing fish and human diseases, and isolation of novel bacterial strains with antimicrobial activity suggests that marine ecosystem is a valuable source of antimicrobials.…”

“…55b-11 were isolated from Japan which produced low molecular weight compounds inhibitory to the growth of Vibrio strains [11]. There are many reports about antibacterial activity shown by marine bacteria, namely, Pseudomonas, Yersinia, Brevibacterium, Bacillus, and Alteromonas [9,[12][13][14][15]. Recent studies however have targeted bacteria from an increasing assortment of nutrient rich and nutrient poor marine habitats including the surfaces or interior spaces of marine invertebrates in order to fully assess the potential of marine bacteria as a natural drug source.…”

“…Earlier studies focused on terrestrial plants and microbes proved extremely fruitful, yielding many organic bioactive compounds including anticancer drugs [8]. But the potential contribution of marine organisms to the discovery of new bioactive molecules is very challenging [9]. Several bacteria present in aquatic ecosystems possess the ability to inhibit the growth of other microorganisms by producing antimicrobials and other molecules, namely, antibiotics, bacteriocins, siderophores, lysozymes, and proteases [10].…”

Secondary Metabolites from Marine Sources: Review

“…Böylece bu maddelerin ileride HIV gibi enfeksiyöz hastalıklarda etkili olabilecekleri, ayrıca gıda takviyesi olarak ve kozmetik alanında kullanılabile-cekleri düşünülmektedir. [32][33][34][35][36] Deniz kaynaklı etkili maddelerin diğer önemli kullanım alanları da kozmetiktir. Bu alanda en önemli örnek olan Resilience ® , kozmetik firması Estée Lauder tarafından üretilmektedir.…”

Characterization of Streptomyces padanus JAU4234, a Producer of Actinomycin X 2 , Fungichromin, and a New Polyene Macrolide Antibiotic

“…We therefore determined the MICs at which it inhibited 50 and 90% of a selection of Grampositive and Gram-negative bacteria (MIC 50 and MIC 90 , respectively). Compound 1 had strong antibacterial activity against all of the Gram-positive and Gram-negative bacteria examined (Table 1) and was especially effective against S. aureus (MIC 50 , 0.002 g/ml), indicating that compound 1 could have expanded appli- cation as a potential candidate for the treatment of bacterial pathogens such as methicillin-resistant S. aureus and NDM-1-positive bacteria (11). It should, however, be noted that compound 1 induces greater cytotoxicity in cultured human leukemia cells (HL-60) than actinomycin D, through the stimulation of apoptotic pathways (7).…”