﻿554 
  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1943 
  

  

  AGENTS 
  FROM 
  ACTINOMYCETES 
  

  

  The 
  actinomycetes 
  comprise 
  a 
  large 
  group 
  of 
  organisms 
  somewhat 
  

   intermediate 
  between 
  the 
  true 
  bacteria 
  and 
  the 
  higher 
  fungi. 
  They 
  

   are 
  very 
  widespread 
  in 
  nature, 
  occurring 
  in 
  soils, 
  composts, 
  and 
  water 
  

   basins 
  ; 
  the 
  group 
  includes 
  also 
  several 
  species 
  which 
  cause 
  diseases 
  in 
  

   plants 
  and 
  animals. 
  

  

  In 
  1890 
  an 
  Italian 
  worker 
  observed 
  that 
  certain 
  actinomycetes 
  were 
  

   able 
  to 
  destroy 
  the 
  cell 
  membranes 
  of 
  many 
  bacteria 
  and 
  fungi. 
  In 
  

   the 
  ensuing 
  third 
  of 
  a 
  century 
  no 
  further 
  study 
  of 
  this 
  phenomenon 
  

   appears 
  to 
  have 
  been 
  undertaken. 
  During 
  the 
  past 
  two 
  decades, 
  how- 
  

   ever, 
  investigations 
  in 
  a 
  number 
  of 
  laboratories 
  have 
  provided 
  evidence 
  

   that 
  several 
  antimicrobial 
  substances 
  are 
  elaborated 
  by 
  actinomycetes 
  

   and 
  that 
  antagonistic 
  properties 
  are 
  widely 
  distributed 
  among 
  various 
  

   strains 
  of 
  this 
  group 
  of 
  organisms. 
  To 
  date 
  only 
  a 
  few 
  of 
  these 
  active 
  

   substances 
  have 
  been 
  studied 
  to 
  any 
  extent. 
  

  

  Actinomycetin. 
  — 
  In 
  1924 
  two 
  French 
  workers 
  who 
  had 
  been 
  study- 
  

   ing 
  the 
  lysis 
  of 
  killed 
  staphylococci 
  sought 
  to 
  isolate, 
  from 
  air 
  or 
  

   water, 
  micro-organisms 
  which 
  could 
  bring 
  about 
  this 
  process. 
  They 
  

   succeeded 
  in 
  obtaining 
  an 
  actinomycete 
  which 
  was 
  capable 
  of 
  causing 
  

   the 
  disintegration 
  of 
  a 
  large 
  number 
  of 
  microbial 
  species. 
  

  

  The 
  production 
  of 
  the 
  disintegrating 
  agent, 
  or 
  lysin, 
  occurs 
  in 
  

   any 
  medium 
  which 
  permits 
  the 
  growth 
  of 
  the 
  actinomycete 
  and 
  com- 
  

   mences 
  at 
  the 
  time 
  of 
  spore 
  formation 
  ; 
  prior 
  to 
  this 
  stage 
  no 
  activity 
  

   can 
  be 
  demonstrated 
  in 
  either 
  the 
  culture 
  medium 
  or 
  the 
  cells 
  of 
  the 
  

   organism. 
  Preparations 
  of 
  the 
  active 
  principle, 
  winch 
  has 
  been 
  

   designated 
  "actinomycetin," 
  are 
  protein 
  in 
  nature; 
  however, 
  as 
  they 
  

   are 
  further 
  purified, 
  the 
  ratio 
  of 
  protein 
  content 
  to 
  activity 
  decreases. 
  

  

  As 
  previously 
  noted 
  the 
  living 
  actinomycete 
  is 
  capable 
  of 
  lysing 
  

   a 
  great 
  variety 
  of 
  living 
  bacteria 
  and 
  molds. 
  With 
  the 
  exception 
  of 
  a 
  

   few 
  strains 
  of 
  Streptococcus 
  pyogenes, 
  Staphylococcus 
  aureus, 
  and 
  

   Klebsiella 
  pneumoniae, 
  the 
  micro-organisms 
  are 
  resistant 
  to 
  the 
  cell- 
  

   free 
  filtrate 
  of 
  the 
  actinomycete, 
  however. 
  But 
  if 
  the 
  bacteria 
  are 
  

   first 
  killed, 
  by 
  whatever 
  means, 
  they 
  become 
  susceptible 
  to 
  the 
  sterile 
  

   actinomycete 
  culture 
  filtrate. 
  Actinomycetin 
  preparations 
  which 
  

   have 
  been 
  concentrated 
  to 
  the 
  extent 
  of 
  a 
  hundredfold 
  increase 
  in 
  

   potency 
  exhibit 
  the 
  same 
  type 
  of 
  action 
  and 
  specificity 
  as 
  the 
  crude 
  

   culture 
  filtrate. 
  It 
  thus 
  appears 
  that 
  at 
  least 
  two 
  principles 
  are 
  in- 
  

   volved 
  : 
  a 
  lytic 
  factor 
  which 
  can 
  act 
  only 
  upon 
  dead 
  micro-organisms 
  

   and 
  a 
  bactericidal 
  factor 
  which 
  exists 
  in 
  the 
  culture 
  medium 
  in 
  a 
  

   relatively 
  inactive 
  form, 
  albeit 
  sufficiently 
  active 
  to 
  kill 
  the 
  few 
  

   susceptible 
  strains 
  enumerated. 
  

  

  Support 
  for 
  this 
  view 
  has 
  been 
  contributed 
  by 
  the 
  recent 
  discovery 
  

   that 
  on 
  extraction 
  of 
  purified 
  actinomycetin 
  with 
  ether 
  there 
  is 
  ob- 
  

   tained 
  a 
  fraction 
  bactericidal 
  to 
  a 
  number 
  of 
  Gram-positive 
  bacteria. 
  

  

  