Vet. ['athol. / 4: H9-9 1 ( 1977)
Brief Communication
Pneumocystis carinii in a Pig H. R.
SE I IlO L D AND
J . F.
M U N N EL L
A l O-wcc k-o ld pig from a herd in whi ch m ort ality had been 5 % after wea ning was pr e sented for diagn o sis. It had ex te ns ive ne croti c cec itis a nd coliti s . Esche richia coli was cult ure d from th e lun g . No bacte ria we re culture d from liver , splee n and kidn e y . No rma l bact eri al flora was o b tai ned fro m th e int estin e. Nem at od e par asites were not fo und in th e sma ll int e st ine. T he maj or ab no rma lity was su pe rficial a nd de ep ne crosis o f th e mu co sa in th e cecum and colon . In area s whe re necrosis exte nde d to the mu sculari s muco sae , th e sub m ucosa was thicken ed b y pr oli ferati on o f fibrobl asts a nd in filtrati on with macr oph agc s , gra n ulo cy tes, lympho cyt es a nd plas ma ce lls . T he lun g tissu e was co ngested a nd moderat el y e de ma to us . A few p ul mo na ry lobul es a lso had so me ce llula r ex ud a te (m ac roph age s a nd leucocyt e s) in b ronchi ol es a nd a d jace nt a lveo li alon g wit h partial co lla pse of th e a lveo li. Round or ovo id structur es a bo u t th e size of erythrocy tes were cl ust ered in a lveo li a nd a lo ng a lveo lar wa lls . Eac h had a lightl y-stain e d pi nk ca ps ule . The ce ntra l a rea was clear or ha d o ne or more ligh tlystai ne d bl ue , ro u nd int ern al bod ie s . Th ey were m o st num erou s in lobul e s with out ce llula r ex uda te. Wh en sta ine d with th e ch ro m ic a cid-Sc hiff reagent 19] with thre e rin se s o f so d ium bi sulfit e so lu t io n (20 mol /I) a fte r th e Sc h iff re agent ( Ba ue r's sta in), th e caps ule a nd int ern al bodi es stai ne d irregul arl y with fuc hs in . Fewer str uc tures were visib le in th e Bau er-st ain ed tha n H E-st a ined sectio ns. So me of th e struc tu res lo ok ed lik e bl ac k di sk s or ovo ids (f ig . I ) whe n sta ine d wit h Grocott's modifi cat ion of Go rn o ri's meth en amin e- silver nitrat e [7] . M o st , how ev er , lo ok ed holl o w wit h grey o r bla ck bord ers. Th e di agn o sis wa s necroti c cecit is a nd co litis ; th e cause was undet e rmin ed . Th ere was m od e rat e b ron ch o pn eum on ia . Fu rt he r st udy of th e intraal ve ol ar bod ies was indi ca ted beca use th e site, morp hologic a ppea ra nce a nd stai n ing rea cti on s we re co ns iste nt wit h th o se of Pneum ocystis carinii . A lt ho ug h th ere are few reports o f thi s o rga nism in swine, on e re po rt d escribe s it in 4-m onth-old pigs 15]. Fo r ma lin- fixe d lun g was minced int o sma ll blo cks ( I mrn") a nd was he d ove rn ight in 0 . 1 mol /l cacody late bu ffer , p H 7 .2 , be fore fur the r fixa tio n fo r I h in 1% OSO.1 in the sa me bu ffe r. T he blo ck s were d eh ydrated , infiltrat ed a nd e m be d de d in a mi xture o f D o w Q9 e po xy re sin s (DE R 732 a nd D ER 332) 16] . Section s 1- 2 (.tm thi ck were sta ine d with Par agon v multipl e sta in for ligh t micro scope exa m ina t io n . Se lec ted a reas we re sectio ned for e lec tro n microsco py a nd stai ne d with ura ny l ace ta te a nd le ad citra te . H9 Downloaded from vet.sagepub.com at VIRGINIA COMMONWEALTH UNIV on March 13, 2015
90
Brief Co m mun ica tio n
2 Fig. I: Paraffin sec tion o f lun g with sca tte re d we ll-s ta ine d orga n isms a long a lveo lar wa lls. Grocoli's . Fig. 2: O rga nisms in tro phi c stage a t surface o f bron ch io lar e pit he lium (E ). Man y tu bul ar projectio ns fro m th e ce ll wall of th e o rga nis ms (a rrows) .
Sca ttere d single o rga nisms a nd gro u ps o f organi sm s co uld be mo re e as ily see n in th e 1- 2 /Lm se ctio ns th an in th e 6 /Lm paraffin se ct io ns. T he se appeared as round a nd holl o w in th e a lveo la r lum en a nd we re usu all y ad jace nt to th e e pit he lia l linin g ce lls. T he o rga nisms were num erous a nd fo und easi ly by e lectro n microscopy . Tw o fo rms were see n . O ne for m see me d irr egular bu t was ro ug hly circula r o n se ctio n . It ha d a ce ll wall and e it he r see me d e m pty or had sca tte re d flocc ulent ma teria l (fig . 2) . D ia mete rs were from 2 .5 to 4 .5 /Lm . It is probab le t hat cytoplasm had been dis ru pte d by forma lin . T u b ular m icr ovi llus- lik e proj e ct ions from t he ce ll wa ll were so me ti mes numerous (fi g . 2) . T his for m wa s int erpret ed to be the tro phic stage . Suc h pr o jecti on s ha ve be en described in an anastom osing co mplex o f a mem branou s tubular syste m surro u nd ing adj ace nt P . carinii in t he vegeta tiv e stage [4] . We sa w not hin g to support t he t heory tha t th ese re p re sen t react ive pla sm a me mbra nes of alveo lar macrop ha ges [8 ]. A second and le ss num erou s form was of a sim ilar size a nd sha pe but had varyi ng numbers of den se bodi es (fig . 3 ). T his was interpret ed to be th e cys tic stage of th e orga nism a nd th e den se bodi es were believed to be cross-section s of int racys tic bodi es [ 1- 3] . A pr esumptive ident ificati on o f pneumocysti s wa s made on th e basis of light mi cro scopic mo rphol o gy , sta ining cha racte rist ics and th e di strib ution of th e o rganism s . E lec tro n mi cr oscopy co nfirme d thi s . Alth ough fo rm a lin fixati on wa s not optima l for fine struc tura l st udy , e no ug h fea t ures cha rac te ristic o f th e orga nism in ra t and hum an tissu es [1 , 3. 4 , 8]. we re pr es erved to a llow identificati on . A lth ough t here ha s no t been a grea t incid en ce of pn eum ocystis pn eum onia in dom e sti c an im al s 13]. ve te rina ry path olo gist s sho uld be a wa re of th e dis e a se .
Downloaded from vet.sagepub.com at VIRGINIA COMMONWEALTH UNIV on March 13, 2015
..
91
Brief Co mmunicatio n
T
c ·T
3 Fig. 3: Trop hic forms (T) a nd a cystic for m (C). Five sec tio ns of int racys tic bo dies arc in the cystic form . Cyto plasmic detail disr up ted by fixat ive .
References
2 3 4 5 6 7 II 9
Barto n . E. G .. jr .: Ca mpbe ll. W.G .: Pne umocvstis carinii in lungs of rat s treated with cortisone acetate. A m J Pat hoi 54: 20 9- 236 . 196 9 Ca mpbe ll. W. G .: Ultrastru cture of Pn eumocystis in human lung. A rch Path ol 93: 31 2- 324. 1972 Farrow . B.R .H ; Wat so n . A . D J .; Hart ley . WJ .: Pneumocystis pneumonia in the dog . J Comp Pat hoi 82 :4 45- 453 . 1972 Ham . E .K.; G ree nbe rg . S. D .; Reynold s . R .C. ; Singer . D .B .: Ultrastructure of Pneumocystis carinii . Exp Mo1Path oi 14: 362- 372. 197 1 Kuce ra . K .; Siesingr . L. ; Kadl ec , A .: I'ne umocystosis in pigs. Folia Par asitol ( Praha) 15:75- 711 . 19611 Lockwood . W.R .: A rel iabl e and eas ily sect ioned epoxy resin emhedding medi um. Anat Rcc 150:1 29-1 40 . 1964 Luna . L. G . (ed .) : Man ua l of histol ogic sta ining methods of th e A rmed Forces Inst itute of Pathology; 3 rd cd .. p . 230; McGraw- HilI. Ne w York . N. Y.. 196 11 Price . R .A .; Hughes . W.T .: Hist o pa th ology of Pn eumocystis carinii infestation and infe ction in malignant disease of child hoo d. Hu m Pat hoi 5: 737- 752 . 1974 T ho mp so n . S.W .: Selected histoch emical and histopathological methods; 1st cd .. p . 49 6 ; C har les C T ho ma s. Sp ringfie ld . III.. 196 6
Request re prints fro m D r. H . R . Seibold . Litt on Bio ncti cs, Kensingto n . M D 207 95 (U SA) .
Downloaded from vet.sagepub.com at VIRGINIA COMMONWEALTH UNIV on March 13, 2015
Brief Communication
Pneumocystis carinii in a Pig H. R.
SE I IlO L D AND
J . F.
M U N N EL L
A l O-wcc k-o ld pig from a herd in whi ch m ort ality had been 5 % after wea ning was pr e sented for diagn o sis. It had ex te ns ive ne croti c cec itis a nd coliti s . Esche richia coli was cult ure d from th e lun g . No bacte ria we re culture d from liver , splee n and kidn e y . No rma l bact eri al flora was o b tai ned fro m th e int estin e. Nem at od e par asites were not fo und in th e sma ll int e st ine. T he maj or ab no rma lity was su pe rficial a nd de ep ne crosis o f th e mu co sa in th e cecum and colon . In area s whe re necrosis exte nde d to the mu sculari s muco sae , th e sub m ucosa was thicken ed b y pr oli ferati on o f fibrobl asts a nd in filtrati on with macr oph agc s , gra n ulo cy tes, lympho cyt es a nd plas ma ce lls . T he lun g tissu e was co ngested a nd moderat el y e de ma to us . A few p ul mo na ry lobul es a lso had so me ce llula r ex ud a te (m ac roph age s a nd leucocyt e s) in b ronchi ol es a nd a d jace nt a lveo li alon g wit h partial co lla pse of th e a lveo li. Round or ovo id structur es a bo u t th e size of erythrocy tes were cl ust ered in a lveo li a nd a lo ng a lveo lar wa lls . Eac h had a lightl y-stain e d pi nk ca ps ule . The ce ntra l a rea was clear or ha d o ne or more ligh tlystai ne d bl ue , ro u nd int ern al bod ie s . Th ey were m o st num erou s in lobul e s with out ce llula r ex uda te. Wh en sta ine d with th e ch ro m ic a cid-Sc hiff reagent 19] with thre e rin se s o f so d ium bi sulfit e so lu t io n (20 mol /I) a fte r th e Sc h iff re agent ( Ba ue r's sta in), th e caps ule a nd int ern al bodi es stai ne d irregul arl y with fuc hs in . Fewer str uc tures were visib le in th e Bau er-st ain ed tha n H E-st a ined sectio ns. So me of th e struc tu res lo ok ed lik e bl ac k di sk s or ovo ids (f ig . I ) whe n sta ine d wit h Grocott's modifi cat ion of Go rn o ri's meth en amin e- silver nitrat e [7] . M o st , how ev er , lo ok ed holl o w wit h grey o r bla ck bord ers. Th e di agn o sis wa s necroti c cecit is a nd co litis ; th e cause was undet e rmin ed . Th ere was m od e rat e b ron ch o pn eum on ia . Fu rt he r st udy of th e intraal ve ol ar bod ies was indi ca ted beca use th e site, morp hologic a ppea ra nce a nd stai n ing rea cti on s we re co ns iste nt wit h th o se of Pneum ocystis carinii . A lt ho ug h th ere are few reports o f thi s o rga nism in swine, on e re po rt d escribe s it in 4-m onth-old pigs 15]. Fo r ma lin- fixe d lun g was minced int o sma ll blo cks ( I mrn") a nd was he d ove rn ight in 0 . 1 mol /l cacody late bu ffer , p H 7 .2 , be fore fur the r fixa tio n fo r I h in 1% OSO.1 in the sa me bu ffe r. T he blo ck s were d eh ydrated , infiltrat ed a nd e m be d de d in a mi xture o f D o w Q9 e po xy re sin s (DE R 732 a nd D ER 332) 16] . Section s 1- 2 (.tm thi ck were sta ine d with Par agon v multipl e sta in for ligh t micro scope exa m ina t io n . Se lec ted a reas we re sectio ned for e lec tro n microsco py a nd stai ne d with ura ny l ace ta te a nd le ad citra te . H9 Downloaded from vet.sagepub.com at VIRGINIA COMMONWEALTH UNIV on March 13, 2015
90
Brief Co m mun ica tio n
2 Fig. I: Paraffin sec tion o f lun g with sca tte re d we ll-s ta ine d orga n isms a long a lveo lar wa lls. Grocoli's . Fig. 2: O rga nisms in tro phi c stage a t surface o f bron ch io lar e pit he lium (E ). Man y tu bul ar projectio ns fro m th e ce ll wall of th e o rga nis ms (a rrows) .
Sca ttere d single o rga nisms a nd gro u ps o f organi sm s co uld be mo re e as ily see n in th e 1- 2 /Lm se ctio ns th an in th e 6 /Lm paraffin se ct io ns. T he se appeared as round a nd holl o w in th e a lveo la r lum en a nd we re usu all y ad jace nt to th e e pit he lia l linin g ce lls. T he o rga nisms were num erous a nd fo und easi ly by e lectro n microscopy . Tw o fo rms were see n . O ne for m see me d irr egular bu t was ro ug hly circula r o n se ctio n . It ha d a ce ll wall and e it he r see me d e m pty or had sca tte re d flocc ulent ma teria l (fig . 2) . D ia mete rs were from 2 .5 to 4 .5 /Lm . It is probab le t hat cytoplasm had been dis ru pte d by forma lin . T u b ular m icr ovi llus- lik e proj e ct ions from t he ce ll wa ll were so me ti mes numerous (fi g . 2) . T his for m wa s int erpret ed to be the tro phic stage . Suc h pr o jecti on s ha ve be en described in an anastom osing co mplex o f a mem branou s tubular syste m surro u nd ing adj ace nt P . carinii in t he vegeta tiv e stage [4] . We sa w not hin g to support t he t heory tha t th ese re p re sen t react ive pla sm a me mbra nes of alveo lar macrop ha ges [8 ]. A second and le ss num erou s form was of a sim ilar size a nd sha pe but had varyi ng numbers of den se bodi es (fig . 3 ). T his was interpret ed to be th e cys tic stage of th e orga nism a nd th e den se bodi es were believed to be cross-section s of int racys tic bodi es [ 1- 3] . A pr esumptive ident ificati on o f pneumocysti s wa s made on th e basis of light mi cro scopic mo rphol o gy , sta ining cha racte rist ics and th e di strib ution of th e o rganism s . E lec tro n mi cr oscopy co nfirme d thi s . Alth ough fo rm a lin fixati on wa s not optima l for fine struc tura l st udy , e no ug h fea t ures cha rac te ristic o f th e orga nism in ra t and hum an tissu es [1 , 3. 4 , 8]. we re pr es erved to a llow identificati on . A lth ough t here ha s no t been a grea t incid en ce of pn eum ocystis pn eum onia in dom e sti c an im al s 13]. ve te rina ry path olo gist s sho uld be a wa re of th e dis e a se .
Downloaded from vet.sagepub.com at VIRGINIA COMMONWEALTH UNIV on March 13, 2015
..
91
Brief Co mmunicatio n
T
c ·T
3 Fig. 3: Trop hic forms (T) a nd a cystic for m (C). Five sec tio ns of int racys tic bo dies arc in the cystic form . Cyto plasmic detail disr up ted by fixat ive .
References
2 3 4 5 6 7 II 9
Barto n . E. G .. jr .: Ca mpbe ll. W.G .: Pne umocvstis carinii in lungs of rat s treated with cortisone acetate. A m J Pat hoi 54: 20 9- 236 . 196 9 Ca mpbe ll. W. G .: Ultrastru cture of Pn eumocystis in human lung. A rch Path ol 93: 31 2- 324. 1972 Farrow . B.R .H ; Wat so n . A . D J .; Hart ley . WJ .: Pneumocystis pneumonia in the dog . J Comp Pat hoi 82 :4 45- 453 . 1972 Ham . E .K.; G ree nbe rg . S. D .; Reynold s . R .C. ; Singer . D .B .: Ultrastructure of Pneumocystis carinii . Exp Mo1Path oi 14: 362- 372. 197 1 Kuce ra . K .; Siesingr . L. ; Kadl ec , A .: I'ne umocystosis in pigs. Folia Par asitol ( Praha) 15:75- 711 . 19611 Lockwood . W.R .: A rel iabl e and eas ily sect ioned epoxy resin emhedding medi um. Anat Rcc 150:1 29-1 40 . 1964 Luna . L. G . (ed .) : Man ua l of histol ogic sta ining methods of th e A rmed Forces Inst itute of Pathology; 3 rd cd .. p . 230; McGraw- HilI. Ne w York . N. Y.. 196 11 Price . R .A .; Hughes . W.T .: Hist o pa th ology of Pn eumocystis carinii infestation and infe ction in malignant disease of child hoo d. Hu m Pat hoi 5: 737- 752 . 1974 T ho mp so n . S.W .: Selected histoch emical and histopathological methods; 1st cd .. p . 49 6 ; C har les C T ho ma s. Sp ringfie ld . III.. 196 6
Request re prints fro m D r. H . R . Seibold . Litt on Bio ncti cs, Kensingto n . M D 207 95 (U SA) .
Downloaded from vet.sagepub.com at VIRGINIA COMMONWEALTH UNIV on March 13, 2015
