Dual infection with Pneumocystis carinii and Pasteurella pneumotropica in B cell-deficient mice: diagnosis and therapy.
OBJECTIVE
The clinical presentation, diagnosis, histopathologic findings, and elimination of dual respiratory tract infection with Pasteurella pneumotropica and Pneumocystis carinii were studied in 100 adult barrier-reared C.B17 and MRL- lpr mice homozygous for a targeted mutation of the JH region of the immunoglobulin heavy chain.


METHODS
Necropsy, aerobic bacteriologic culture of hematogenous and pulmonary tissues, histochemical staining of pulmonary tissues, polymerase chain reaction analysis of pulmonary tissues and feces, and viral serologic testing were performed on 19 clinically affected mice and 8 clinically normal mice, then later on antibiotic-treated and caesarian re-derived mice. Therapeutic strategies included sequential administration of trimethoprim/ sulfamethoxazole and enrofloxacin or enrofloxacin administration and caesarian rederivation.


RESULTS
Clinically affected mice had diffuse, nonsuppurative, interstitial pneumonia with superimposed pyogranulomatous lobar pneumonia that was detected microscopically. Affected lung tissue yielded pure culture of P. pneumotropica. Aged-matched, clinically normal mice of both genotypes had interstitial histiocytic pneumonia without lobar pneumonia, and P. pneumotropica was not isolated. Histochemical staining of lung tissues from normal and clinically affected mice revealed scattered cysts consistent with P. carinii, principally in the interstitium. Treatment with sulfamethoxazole/trimethoprim and enrofloxacin eliminated bacteriologic detection of P. pneumotropica, decreased mortality from 50% to 6%, and improved breeding performance.


CONCLUSIONS
A successful antibiotic therapy and rederivation approach, incorporating enrofloxacin, cesarian section, and isolator rearing, was developed for B cell-deficient mice with opportunistic infections.
Macy
J D
JD
Yale University School of Medicine, New Haven, Connecticut, USA.
Weir
E C
EC
Compton
S R
SR
Shlomchik
M J
MJ
Brownstein
D G
DG
D000818:Animals; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001402:B-Lymphocytes / Q000276:immunology; D002585:Cesarean Section / Q000662:veterinary; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D000077422:Enrofloxacin; D005243:Feces / Q000382:microbiology; D005260:Female; D024841:Fluoroquinolones; D007150:Immunohistochemistry; D008168:Lung / Q000382:microbiology / Q000473:pathology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR / Q000276:immunology*; D010325:Pasteurella / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D010326:Pasteurella Infections / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy / Q000662:veterinary*; D011010:Pneumocystis / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D018410:Pneumonia, Bacterial / Q000150:complications / Q000188:drug therapy / Q000662:veterinary*; D011020:Pneumonia, Pneumocystis / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy / Q000662:veterinary*; D016133:Polymerase Chain Reaction / Q000662:veterinary; D015363:Quinolones / Q000627:therapeutic use; D012376:Rodent Diseases / Q000175:diagnosis* / Q000188:drug therapy; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000627:therapeutic use
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000970:Antineoplastic Agents; D004269:DNA, Bacterial; D024841:Fluoroquinolones; D015363:Quinolones; D000077422:Enrofloxacin; D015662:Trimethoprim, Sulfamethoxazole Drug Combination