Clinical andimmunological reactions toAspergillus niger among workers atabiotechnology plant

Theworkforce ata biotechnology plantproducing citric acidbyfermentation of molasses with astrain ofAspergillus niger was studied. A combination ofarespiratory question- naire andclinical assessment identified 18subjects (4-9%oftheworkforce) withworkrelated bronchospasm. Innineofthese evidence ofsensitisation toA niger was obtained byskinprick tests andradioallergosorbent test(RAST)using asan antigen an extract oftheA niger culture fluid fromtheprocess.Ofthe325subjects without workrelated bronchospasm, onlynine(2.7%) hada positive prick test. There were no subjects withsymptomsofextrinsic allergic alveolitis. Investigation intothesourceoftheantigen showedthat whereas, insome areasoftheplant, A niger sporeswere present, inothers there were no detectable spores.Inthese areas,however, extracts offilters fromairsamplers were shownbyRASTinhibition tocontain A niger antigens, indicating that theculture fluid was generating airborne antigen. RASTinhibition studies showed thattheA niger culture fluid usedintheprocesscontained antigens that were notpresentina commercially available A niger extract, thusemphasising theimportance inthis typeofinvestiga- tionofusing antigens prepared frommaterial towhichtheworkers areexposed. Micro-organisms havebeenusedintheproduction offoodformanycenturies; theEgyptians disco- vered around 4000BCthat thecarbon dioxide gen- erated bytheaction ofbrewer's yeast could leaven bread, andtheability ofyeast tomakealcohol inthe formofbeerwasknownbefore that. Nevertheless, it isonlywithin thepast50years that micro-organisms havebeenextensively usedinthesynthesis ofchem- icals onanindustrial scale. Thedevelopment of genetic engineering hasresulted infurther rapid growthintheapplication ofmicro-organisms to industrial processes andmorethan40 micro- organisms, including species ofyeasts, fungi, and bacteria, arenowusedintheproduction ofproducts suchasfood,chemicals, vitamins, enzymes, and pharmaceuticals.' Oneofthepotential hazards ofthese processes is thesensitisation ofworkers toairborne micro- organisms andculture fluid material whichmay result ineither extrinsic allergic alveolitis orasthma. Several fungal species havebeenidentified ascauses