Identification of a haemolysin-like peptide with antibacterial activity using the draft genome sequence ofStaphylococcus epidermidisstrain A487

Abstract

Our interest in Staphylococcus epidermidis strain A487 was prompted by the unusual nature of its inhibitory activity in screening tests against methicillin-resistant Staphylococcus aureus isolates. The inhibitory activity was detected in deferred antagonism tests only if the agar plate was preheated for at least 35 min at ≥ 55 °C before inoculation of the indicator bacteria, this phenomenon indicating possible involvement of a heat-labile immunity agent or protease. The inhibitor was purified to homogeneity by ammonium sulphate precipitation, followed by cation-exchange and reversed-phase chromatography. Tandem MS revealed a novel peptide of molecular weight 2588.4 Da. The draft genome sequence of strain A487 was determined using 454 GS FLX technology, allowing the identification of the structural gene (hlp) encoding the mature peptide MQFITDLIKKAVDFFKGLFGNK. The deduced amino acid sequence of peptide 487 exhibited 70.8% similarity to that of a putative haemolysin from Staphylococcus cohnii. Analysis of the genome of strain A487 showed several additional inhibitor-encoding genes, including hld, the determinant for staphylococcal δ-lysin. This work indicates that potentially useful inhibitors could be overlooked in agar-based inhibitor screening programmes lacking a heat pretreatment step and also highlights the utility of draft genome sequence examination in antibacterial agent discovery.

Fungal proteinaceous compounds with multiple biological activities

“…Nonfungal (i.e., bacterial, plant, animal, and/or human) counterparts (Al-Mahrous et al 2011;Citores et al 2016;Iglesias et al 2016;Jiratchariyakul et al 2001;Ogawa 2016;Ouyang et al 2006;Sartim and Sampaio 2015;Singh et al 2016) of the various fungal proteins and peptides very often are endowed with biological activities qualitatively analogous to the fungal proteins and peptides, although the structural homology may not be extensive. However, some differences in biological activity may exist.…”

Identification and Characterization of Three Novel Lipases Belonging to Families II and V from Anaerovibrio lipolyticus 5ST

“…The 454 technology has been used successfully in a number of studies to establish draft and complete bacterial genomes and establish their gene catalogues, for example for the bacteria Leuconostoc argentinum , Lactobacillus animalis [31], [32], Staphylococcus epidermidis A487 [33], Acinetobacter baumannii [34]; and, combined with other sequencing platforms, the genomes of the rumen bacteria Megasphaera elsdenii [35], Ruminococcus albus [36] and Fibrobacter succinogenes [37].…”

Comparative Exoprotein Profiling of Different Staphylococcus epidermidis Strains Reveals Potential Link between Nonclassical Protein Export and Virulence

“…Staphylococcus epidermidis, belonging to coagulase-negative staphylococci (CoNS), is a common colonizer of the human skin that has evolved a benign relationship with the host. Although SE may even balance the healthy microbiota of the human skin and mucous membranes, − it is an opportunistic pathogen and one of the most frequent causes of nosocomial infections, particularly in immunocompromised patients . These SE nosocomial infections are rarely life-threatening, as SE lacks many virulence determinants, such as the toxins and aggressive exoenzymes often associated with other major pathogens. ,, However, SE infections are difficult to treat because of the frequent occurrence of multidrug-resistant strains and because of SE’s ability to form biofilms that cause resistance both to drugs and the host immune system. , …”