North & South – June 2019

44 | NORTH & SOUTH| JUNE 2019

libraries– theyhavemillionsofthem

• thatmightpreventthebacteriafrom
  producingthesulfurcompounds.”It’sa
  novelapproachtohelptheimmunesys-
  temfightinfections.“We’resaying,let’s
  notjusttrytodevelopa newantibiotic,
  becausethebugsaregoingtobecome
  resistanttoit ina matterofyears.Let’s
  usea bitofstealthsothebugsaremuch
  lesslikelytofindwaystoresistdrugs.”
  Ironically,saysVictoriaUniversity’s
  biotechnologyprogrammedirectorPro-
  fessorDavidAckerley,theprofligate
  useofantibioticsinthelasthalfofthe
  20thcenturyandthegrowingriskof
  resistancehasmadethesearchfornew
  antimicrobialssuddenlymoreattractive
  toscientists.“Thingsstartedtopeter
  out towards the end of the 1970s because

thecells,othersmightmaketheircell

wallsmoreresistanttotheantibiotic.

Mycobacteria– thebugsinvolvedinthe

developmentoftuberculosis– produce

smallsulfurcompoundsthatshieldthem

againsttheactionoftheimmunesystem.

Christchurch-basedKettleandhis

teamfromtheCentreforFreeRadical

Researchreceiveda $5million,five-year

grantfromtheHealthResearchCouncil

in2015.Partoftheirbriefwastoinves-

tigatedrugsdesignednottokillthemy-

cobacteria,buttodisarmtheirdefence

mechanismsagainsttheneutrophils,al-

lowingtheimmunesystemtokillthem.

“Wethinkthesesulfurcompoundsare

goingtobea majortargetfordrugs.We

wanttoworkwithdrugcompaniesto

see what chemicals they have in their

usetocleanthetoilet.Butwhileneu-
trophilskillbacteriasuchasStaphylo-
coccusaureus“reallyquickly”,theyare
muchlesseffectiveatkillingmycobac-
teria(agroupincludingthosethatcause
TBandleprosy).
“TBisverycleveratevadingourim-
munesystem,somoreandmoreneutro-
philscomeintothesiteoftheinfection
totrytokillthebacteria.Intheprocess,
neutrophilsendupdamagingthelung,
soyougeta friendly-firesituation.The
immunesystemiswhatendsupkilling
thepersonbecauseit destroysthelung
intheprocessoftryingtokillthebugs.”
Researchfornewantibioticsisoften
aimedatoutwittingbacterialdefence
mechanismsagainstantibiotics.Some
have pumps that expel antibiotics from

Adoctorchecksanx-rayimageatapublicclinicinLima.Peruhas a high number
of cases of a highly contagious resistant strain of tuberculosis.

“TBISVERYCLEVERATEVADINGOURIMMUNESYSTEM,SOMORE

ANDMORENEUTROPHILSCOMEINTOTHESITEOFTHEINFECTIONTO

TRYTOKILLTHEBACTERIA.INTHEPROCESS,NEUTROPHILSENDUP

DAMAGINGTHELUNG,SOYOUGETAFRIENDLY-FIRE SITUATION.

PROFESSOR TONY KETTLE, OTAGO UNIVERSITY

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