Lactobacillus septic arthritis.

Abstract: Lactobacillus is a Gram positive bacteria found in the mouth, gastrointestinal and female genital tract. Serious infections due to Lactobacillus are becoming increasingly common. We present a 49-year-old diabetic patient with Lactobacillus septic arthritis. To our knowledge, this is the first reported case. Usually, Lactobacillus is implicated with bacteremia, endocarditis and more rarely pneumonia, meningitis and endovascular infection, and half of the cases are reported in immunocompromised patients. As in our patient, diabetes mellitus is a comorbid condition which has been clearly noted. Our finding suggests that further studies are necessary to establish the significance of Lactobacillus as an etiologic agent of septic arthritis.

Key Words: septic arthritis, Lactobacillus infection

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Lactobacillus is a Gram positive bacteria usually found in the mouth, gastrointestinal and female genital tracts. Serious infections due to Lactobacilli have been reported, especially endocarditis and bacteremia. (1) We report a patient with Lactobacillus septic arthritis. To our knowledge, this is the first reported case.

Case Report

A 49-year-old woman with diabetes mellitus was admitted for right shoulder pain, which appeared 15 days before admission. After inconclusive x-ray investigation, the patient was given antalgic and anti-inflammatory treatments with no improvment and was infused with hydroprednisone. At admission, she presented with fever (38.5[degrees]C), a persistent painful shoulder and signs of synovial effusion. The remainder of the examination was normal. Laboratory studies revealed an inflammato-rysyndrome (C protein reactive: 396 mg/L, elevated erythrocyte sedimentation rate: 126 mm), and a white blood cell count of 9800 [mm.sup.3] (7300/[mm.sup.3] neutrophil polynuclears). HIV serology was negative. X-ray studies remained normal. An echocardiogram showed no abnormalities. Examination of the synovial fluid revealed purulent fluid, with 45,000 white cells/[mm.sup.3]. Lactobacilli were identified by standard methods including characteristic Gram stain morphology after growth on agar media (incubated aerobically and anaerobically), and a negative catalase reaction. Species identification was performed on APJ CH test kit and API CHL medium. Strains isolated from both blood and articular fluid cultures had the same phenotypic pattern and belonged to the L acidophilus group. Sensitivity to antibiotics was tested on agar plates by disk diffusion method. The patient's strain was sensitive to penicillin G, ampicillin, macrolides, rifampicin, glycopeptides, aminoglycosides, and was resistant to trimethoprim sulfamethoxazole and levofloxacin. The patient was treated with intravenous metronidazole and amoxicillin. Persistent fever and local inflammatory signs, in addition to multiples abscesses disclosed on magnetic resonance imaging, lead to surgical drainage five days after the start of antibiotherapy. Finally, clinical and biologic abnormalities disappeared. Metronidazole and amoxicillin were given for 15 days and 6 weeks, respectively, after surgery without relapse.

Discussion

To our knowledge, no Lactobacillus-associated arthritis has been reported in the literature. Only one of the nine patients with Lactobacillus bacteremia from Bayer's study, (2) had signs of septic arthritis, but microbacteriologic studies were negative. Lactobacillus is increasingly involved in systemic infections, especially endocarditis and bacteremia. (1) Half of the cases are reported in immunocompromised patients. (1,3-7) Diabetes mellitus is a comorbid condition which has been clearly noted in 3 of 12 patients in Antony's study1 and in 27% in Husni's study. (3) The use of selective oral bowel decontamination and antibiotic use could contribute to the digestive colonization by Lactobacillus and bacteremia. (3,4,6) Local risk factors for infection have been reported in digestive localization as well. (3,4,8)

Lactobacillus species is implicated with bacteremia. (1,3,4) Bacteremia frequently arises from localized suppuration involving the natural sites of Lactobacillus (1): oral cavity, digestive, genital and urinary tracts. (1,9) However, occult bacteremia has reportedly been isolated. (1) Endocarditis is one of the most common clinical syndromes reported so far. (3,10) Other clinical syndromes associated with Lactobacillus infection include pneumonia, meningitis (10) and endovascular infection. (3) Lactobacillus is a relatively avirulent pathogen, and the mortality rate appears to be low. Only 3 of 8 deaths of the 55 patients in Antony's study, (1) and 1 of 22 deaths of the 45 patients of Husni's study (3) were attributable to Lactobacillus infection.

The Lactobacillus genus includes several groups, which are divided into subgroups. L rhamnosus is the most frequent species isolated. The L acidophilus group is less incriminated as a human pathogen and is divided in two subgroups (L acidophilus, which includes L acidophilus, L amylo-vorus, L crispatus, L gallinarum, and L gasseri, which includes L gasseri and L jensenii). Commercially available identification kits based on carbonhydrate fermentation tests fail to identify various Lactobacillus species. (11) Only the whole cell-protein pattern obtained by sodium dodecyl sulfate polyacrylamide gel electrophoresis and molecular techniques allow Lactobacillus species identification. (12,13) Lactobacilli are usually susceptible to penicillin G, ampicillin, imipenem, erythromycin, clindamycin, tetracycline, and chloramphenicol. The third generation cephalosporins vary in their effectiveness against the isolates. Susceptibility to aminoglycosides depends on the Lactobacillus species and bifunctional enzymes have been described in some strains, conferring high resistance levels to gentamicin, kanamycin, tobramycin and netilmicin. (14)

Conclusion

Our finding of Lactobacillus from a blood culture in this patient with septic arthritis suggests that further studies are necessary to establish the significance of Lactobacilli as an etiologic agent of septic arthritis. As infections due to Lactobacillus are becoming increasingly common in both immunocompetent and immunocompromised patients, septic arthritis should be added to the classically recognized Lactobacillus-related infections.

References

1. Antony SJ, Stratton CW, Dummer JS. Lactobacillus bacteremia: description of the clinical course in adult patients without endocarditis. Clin Infect Dis 1996;23:773-778.

2. Bayer AS, Chow AW, Betts M, et al. Lactobacillemia: report of nine cases. Am J Med 1978;64:808-813.

3. Husni RN, Gordon SM, Washington JA, et al. Lactobacillus bacteremia and endocarditis: review of 45 cases. Clin Infect Dis 1997;25:1048-1055.

4. Patel R, Cockerill FR, Porayko MK, et al. Lactobacillemia in liver transplant patients. Clin Infect Dis 1994;18:207-212.

5. Sherman ME, Albrecht M, De Girolami PC, et al. An unusual case of splenic abscess and sepsis in immunocompromised host. Am J Clin Pathol 1981;88:659-662.

6. Chomarat M, Espinouse D. Lactobacillus rhamnosus septicemia in patient with prolonged aplasia receiving ceftadzidime-vancomycin. Eur J Clin Microbiol Infect Dis 1991;10:44.

7. Horwtich CA, Furseth HA, Larson AM, et al. Lactobacillemia in three patients with AIDS. Clin Infect Dis 1995;21:1460-1462.

8. Baltch AL, Buhac I, Agrawal A, et al. Bacteremia after upper gastrointestinal endoscopy. Arch Intern Med 1977;137:594-597.

9. Manzella JP, Harootunian R. Lactobacillemia of renal origin: a case report. J Urol 1982;128:110.

10. Sussman JI, Baron EJ, Goldberg SM, et al. Clinical manifestations and therapy of lactobacillus endocarditis: report of a case and review of the literature. Rev Infect Dis 1986;8:771-776.

11. Felten A, Barreau C, Bizet C, et al. Lactobacillus species identification, H202 production, and antibiotic resistance and correlation with human clinical status. J Clin Microbiol 1999;37:729-733.

12. Ryu CS, Czajka JW, Sakamoto M, et al. Characterization of the Lactobacillus casei group and the Lactobacillus acidophilus group by automated ribotyping. Microbiol Immunol 2001;45:271-275.

13. Kullen MJ, Sanozky-Dawes RB, Crowell DC, et al. Use of the DNA sequence of variable regions of the 16S rRNA gene for rapid and accurate identification of bacteria in the Lactobacillus acidophilus complex. J Appl Microbiol 2000;89:511-516.

14. Tenorio C, Zarazaga M, Martinez C, et al. Bifunctional enzyme 6'-N-aminoglycoside acetyltransferase-2"-O-aminoglycoside phosphotransferase in Lactobacillus and Pediococcus isolates of animal origin. J Clin Microbiol 2001;39:824-825.

V. Chanet, MD, P. Brazille, S. Honore, M. Michel, A. Schaeffer, and V. Zarrouk

From Service de Medecine Interne, Boulevard Leon Malfreyt, Hotel Dieu, Clermont Ferrand Cedex 1, France; Service de Medecine Interne I; and Service de Bacteriologie-Virologie-Hygiene, hopital Henri Mondor, Creteil cedex, France.

Reprint requests to Chanet Valerie, Medecine Interne. Hotel Dieu, Boulevard Leon Malfreyt, BP 69, 63003 Clermont Ferrand Cedex 1. Email: [e-mail]

Accepted September 8, 2005.

RELATED ARTICLE: Key Points

* Lactobacillus is generally found in the mouth, gastrointestinal regions and female genital tracts.

* Serious infections due to Lactobacillus are increasingly being recognized.

* Lactobacillus is implicated with bacteremia, endocarditis and more rarely pneumonia, meningitis and endovascular infections, and half of the cases are reported in immunocompromised patients.

* Our patient was found to have Lactobacillus septic arthritis.