fastidious bacteria, may favor coloni- zation of the respiratory tree by P. ce- pacia. In order to determine the role of P. cepacia in pulmonary disease of CF patients, prospective, carefully controlled clinical studies on the rote of P. cepacia in the disease of these individuals are needed, as well as studies to understand any virulence factors wtlich P. cepacia might pos- sess, and any host factor that might favor P. cepacia colonization.

References 1. Blessing, J. et. al. 1979. Pseudo-

monas cepacia and maltophilia in the cystic fibrosis patient. Am. Rev. Respir. Dis. 119:262.

2. Carson, L. A. et al. 1973. Morpho- logical, biochemical, and growth char-

acteristics of Pseudomonas cepacia from distilled water. Appl. Microbiol. 25:476-483.

3. Geftic, S. G., H. lleymann, and F. W. Adair. 1979. Fourteen-year survival of Pseudomonas cepacia pre- served with benzalkonium chloride. Appl. Environ. Microbiol. 37:505- 510.

4. Gelbart, S. M., G. F. Reinhardt, and H. B. Greenlee. 1976. Pseudo- monas cepacia strains isolated from water reservoirs of unheated nebu- lizers. J. Clin. Microbiol. 3:62-66.

5. Gilardi, G. L. 1976. Pseudomonas species in clinical microbiology. Mount Sinai J. Med. 43:710-726.

6. Mackenzie, L. L., and P. H. Gil- ligan. 1983. Pseudomonas cepacia in patients with cystic fibrosis. Abst. no. C34 83rd Ann. Meeting Amer. Soc. Microbiol. New Orleans, LA.

7. Moody, M. R., and V. M. Young. 1975. In vitro susceptibility of Pseudo- monas cepacia and Pseudomonas mal- tophilia to trimethoprim and trimetho- prim-sulfamethoxazole. Antimicrob. Agents Chemother. 7:836-839.

8. Sobel, J. D. et ai. 1982. Nosocomial Pseudomonas cepacia infection associ- ated with chlorhexidine contamination. Amer. J. Med. 73:183-188.

9. Stover, G. B., D. R. Drake, and T. C. Montie. 1983. Virulence of dif- ferent Pseudomonas species in a burned mouse model: tissue coloniza- tion by Pseudomonas cepacia. Infect. Immun. 41:1099-1104.

10. Rosenstein, B. J., and D. E. Hall. 1980. Pneumonia and septicemia due to Psettdomonas cepacia in a patient with cystic fibrosis. Johns Hopkins Med. J. 147:188-189.

Case Report

Tularemia in a Pediatric Patient

Roberta B. Carey, Ph.D. Marc O. Beem, M.D. Pediatric Microbiology Laboratory Department of Infectious Diseases tVyler Children's Hospital The University of Chicago Chicago, Hlinois 60637

A two and one-half-year-old girl was seen in late June for enlarged and draining lymph glands on the back of her neck. Her illness began in mid- May when she returned to her Chicago suburban home from a brief visit to a semirural setting in southern Illinois. When she arrived home, she devel- oped malaise, fever, and vomiting that were to persist for the next five days. A diagnosis of "UTI and acute respi- ratory infection" was made during an evaluation at a local emergency room and amoxicillin was started. Shortly thereafter an enlarged node developed in the right posterior occipital region, and her mother had also noted a small, crusted, scalp lesion on the right side of her occiput. Two additional nodes developed on her neck, although she was-_a.febrile and feeling reasonably well at that time. The swollen nodes did not resolve with the continued treatment with amoxicillin or the sub-

sequent change of therapy to oxacillin. A month after the initial symptoms ap- peared, the uppermost nodular lesion, which had become fluctuant, was in- cised and drained. Aerobic cultures of the material obtained at that time grew only an Aspergilhts species that was deemed a probable contaminant by the reporting laboratory. The CBC and an erythrocyte sedimentation rate were within normal limits, and a 5 T.U. PPD skin test was negative.

Noteworthy findings at the time of her visit were limited to the scalp and neck. On the.right occipital scalp there was a 5-mm crust that was ad- herent to seemingly healed skin. Below this, in linear array, were three nodular lesions each measuring roughly 1.5 × 3 cm. The uppermost was draining moderate amounts of pu- rulent material, the middle was pur- plish-red and fluctuant, and the lower one had a firm, rubbery consistency. " None were tender. Microscopic exam- ination of Gram and acid fast stained smears of the exudatewere negative.

Aspiration of the middle node with an 18-gauge needle yielded 3 ml of yellowish-brown pus. Smears were stained by the Brown and Hopps mod-

4 4 0196-4399,'84/$0.00 + 02.00

ified Gram stain and the Giemsa and Hoechst stains. Microscopic examina- tion of this material revealed many polymorphonuclear cells and no micro- organisms. Cultures on chocolate agar, Martin-Lewis chocolate agar, and Sabouraud's agar were negative for aerobic bacteria and fungi, but her serum antibody titer to Francisella tu- larensis was found to be 1:10,000 by the tube agglutination (Fisher Diagnos- tics, Orangeburg, NJ).

The child was subsequently treated with streptomycin 30 mg/kg adminis- tered twice daily for 10 days. The discharge from the uppermost draining node diminished markedly, but the other two became tensely fluctuant and were incised and drained. One month later, all nodes were much smaller but remained unhealed. The upper one yielded small amounts of purulent dis- charge and the lower two were "scabbed over and oozing." The child seemed well otherwise and healing was complete two months after the initiation of the streptomycin therapy.

Tularemia is primarily a disease of wild rodents and other mammals, which is spread by arthropod vectors. Man, an accidental host, is infected by insect bites or direct contact with in- fected animal tissues.

Approximately three days following exposure, the patient experiences an abrupt onset of flulike symptoms in- cluding fever, chills, headache, and vomiting. Soon thereafter an erythem- atous papule develops at the site of entry of the organism. This rapidly progresses to pustule formation and ul- ceration, with enlargement of the re- gional lyr~ph nodes. This course of events, termed ulceroglandular disease, is seen in 80% of-cases. Less com- monly, the disease may present in an oculoglandular, pneumonic, gastroin- testinal, or oropharyngeal form.

Francisella tularensis can be iso- lated from the lesion, lymph nodes, sputum, gastric aspirate, and nasopha- ryngeal washings during the systemic phase of the illness, regardless of the type of clinical disease. Conjunctival scrapings may yield the organism in the oculoglandular disease. However, the organism is rarely recovered in the blood after the first few days of fll- ness.

Because of the high risk of aerosol infection, laboratory workers should observe all known safety precautions when handling material for culture. Work should be performed under a laminar flow hood, and gown, mask, and gloves should be worn. The spec- imen may be frozen at -30°C in sterile broth and forwarded to a refer- ence laboratory that is willing to ac- cept the specimen for culture.

The organism's nutritional require- ments are not met by culture media or- dinarily used in the diagnostic labora- tory; an enriched media, such as cys- tine-glucose blood agar (CGBA), is required for growth. On CGBA the organism appears as small, moist colo- nies surrounded by a partial zone of hemolysis. Primary isolation is diffi- cult because other bacteria present in the specimen may suppress the growth of F. tularensis. The incorporation of penicillin, polymyxin B, and cyclohex- amide into the culture medium has been suggested to eliminate normal skin or respiratory flora. Thayer- Martin chocolate agar with colistin, nystatin, lincomycin, and trimethoprim may-be a satisfactory substitute for the recbvery of these organisms. No addi- tional CO 2 is necessary for growth.

Francisella tularensis is difficult to demonstrate by light microscopy since it stains poorly as a small gram-nega- tive rod. A Giemsa stain has been re- ported to demonstrate the pleomorphic, bipolar morphology, but in our patient, no organisms were observed in the smears of the aspirates.

Francisella tttlarensis can be rapidly identified in appropriate specimens by staining smears with fluorescein-conju- gated antiserum specific for the or- ganism. This reagent is prepared by Difco Laboratories (Detroit, MI), how- ever, the antiserum was not available at our institution or at the state public health laboratory when the specimen was taken.

Althoug h guinea pigs are highly sus- ceptible to infection via the intraperito- neal route, animal inoculation is not recommended unless appropriate housing is available for infectious ani- mals. Francisella tularensis is classi- fied as a Class 3 pathogen, which re- quires special containment facilities for research on this organism. A live, at- tenuated vaccine is available through the Centers for Disease Control for those at a high risk of infection.

Because the laboratory isolation of this organism is both difficult and haz- ardous, serology is most often used to confirm the diagnosis. The tube ag- glutination test becomes positive during the third week of illness. Ti- ters < 1:20 are considered to be nega- tive. Either a fourfold rise in antibody titer, or a convalescent titer of ~1~160, is considered to be diag- nostic. The peak agglutination titer is usually observed at the fifth week of illness, and following recovery, titers from 1:20 to 1:80 may be maintained for years.

The chosen drug for treatment is streptomycin. Tetracycline nlay also be given to the older child or nonpreg- nant patient; however, relapses and chronic infections have been associated with this antibiotic. Effective antimi- crobial therapy does not prevent the development of a diagnostic antibody titer.

Humans acquire this infection by handling rabbit or rodent carcasses, in- gesting contaminated water or partially cooked meat, and inhaling aerosols or

dust containing the organism. In addi- tion, ticks, flies, lice, and mosquitoes may act as vectors. Although the or- ganism is present in the exudates of infected persons, no human-to-human transmission has been reported. Fran- cisella tularensis is extremely suscep- tible to disinfectants, sunlight, and heat.

The majority of cases are reported in Arkansas, Missouri, Illinois, Ten- nessee, Oklahoma, Texas, and Loui- siana. Most cases are reported in the summer months when ticks and deer- flies are prevalent. Persons engaged in agriculture, forestry, and rabbit hunting account for a disproportionate number of cases. The incidence of disease is four times higher in males.

This report demonstrates the impor- tance of considering the diagnosis in a patient who presents with enlarged lymph nodes and skin lesions that do not respond to penicillin therapy. Diagnostic laboratories should be aware of the potential hazards of han- dling these specimens and take all nec- essary precautions. The serologic tests available are the safest and most reli- able methods of confirming the diag- nosis.

References I. Butler, T. 1979. Plague and tula-

remia. Pediat. Clin. North Am. 26:355-366.

2. Ilornlck, R. B. 1982. Tularemia. pp. 641-675. In A. S. Evans and H. A. Feldman (eds.), Bacterial infections of humans. Epidemiology and control. Plenum, New York.

3. Stewart, S. J. 1981. Tularemia. pp. 705-714. bz A. Balows and W. J. Hausler, Jr. (eds.), Diagnostic proce- dures for bacterial, mycotic and para- sitic infections, 6th ed. Am. Public Health Assn., Washington, D.C.

4. Snyder, M. J. 1976. Immune re- sponse to Francisella. pp. 302-303. In N. R. Rose and H. Friedman (eds.), Manual of clinical immunology, American Society for Microbiology, Washington, D.C.

5. Weaver, R. E., and D. G. Ilollls. 1980. Gram negative fermentative bac- teria and Francisella tularensis, pp. 249-253. In E. H. Lennette et al. (eds.), Manual of clinical microbi- ology, 3rd ed. American Society for Microbiology, Washington, D.C.

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