Volume 21, Number 11—November 2015
Letter
Human Infection with Sporolactobacillus laevolacticus, Marseille, France
To the Editor: Sporolactobacillus laevolacticus, formerly known as Bacillus laevolacticus, is a gram-positive, acid-tolerant, catalase-positive, facultatively anaerobic and mesophilic bacteria initially isolated from the rhizosphere of wild plants (1,2). However, there have been no reports of its isolation from humans. We report S. laevolacticus associated with a wound infection and cellulitis in a patient hospitalized in Marseille, France.
In March 2015, a 47-year-old man with no underlying disease was admitted to the emergency unit of the North Hospital in Marseille, France. He had an infected wound on his right foot that occurred after he jogged barefoot during a vacation in Comoros, but the patient did not know how he obtained the wound and had not taken any antiinflammatory drugs. The foot became swollen, red, hot, and painful. He visited a doctor during his vacation and was prescribed antiinflammatory drugs and antimicrobial drugs, including a second-generation cephalosporin and ofloxacin.
Figure
Figure. A) Foot of a 47-year-old man showing wound infected with Sporolactobacillus laevolaticus, Marseille, France. B) Drainage of a cellulitis abscess. C) Extent to which the wound on the arch of the...
The patient returned to Marseille, but the infection persisted. At admission, the patient was apyretic but had high levels of C-reactive protein (85.7 mg/L [reference range 1–3 mg/L]) and fibrinogen (8.35 g/L), which indicated inflammation. His leukocyte count was normal (9.29 ×109 cells/L) but his procalcitonin level (0.19 µg/L) was increased, which suggested that the infection had not been cured. A cellulitis abscess was suspected, and surgical cleaning and drainage was performed on March 10 (Figure, panels A, B).
Samples were collected during surgery and probabilistic antimicrobial drug therapy, including tazocillin, clindamycin, and vancomycin, was initiated. Abscess puncture liquid collected during surgery was sterile when incubated directly on Columbia and Polyvitex agar plates (bioMérieux, Craponne, France). However, a surgical sample inoculated into a blood culture bottle grew gram-positive bacilli after 4 days.
Subculture colonies were identified by using matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (Bruker, Leipzig, Germany) as S. laevolaticus (score 1.88). Identification was confirmed by PCR amplification of the 16S RNA gene (3). A 944-bp sequence showed 99.5% similarity with that of a known S. laevolaticus strain (GenBank accession no. AB362648) by BLAST analysis (http://www.ncbi.nlm.nih.gov).
The S. laevolaticus strain was susceptible to amoxicillin, amoxicillin/clavulanate, imipenem, metronidazole, clindamycin, and vancomycin. The antimicrobial drug regimen was then changed to clindamycin and trimethoprim/sulfamethoxazole, and the patient showed an excellent clinical outcome. The patient was considered clinically cured 7 weeks later (Figure, panel C).
S. laevolacticus has been studied for its capacity to survive extreme conditions and for its fermentation system (4–8). The fact that the bacterium has not been previously isolated from humans might be because it was isolated only from plant rhizospheres (2), so human studies have not been conducted. In addition, conventional identification methods, such as the VITEK 2 system (bioMérieux) or the API system (bioMérieux), cannot identify S. laevolacticus. Since September 2009, we have used MALDI-TOF mass spectrometry in North Hospital for routine identification of bacterial species isolated from clinical samples (9). This strategy increases our capacity to detect rare bacterial species, including emerging pathogens (10).
The bacterial species was accurately identified by using MALDI-TOF and then confirmed by using a 16S RNA PCR. Because the bacterium was originally isolated from a plant rhizosphere and the patient was hospitalized with an open wound in the foot and bacteremia, we speculate that the infection was the direct result of close extended contact between the wound and soil infected with the bacteria. This case confirms that S. laevolaticus can be responsible for human infections and suggests that this bacterial species could be an emerging opportunistic pathogen responsible for human infections.
Acknowledgments
We thank TradOnline (http://www.tradonline.fr/en/) for providing English corrections.
This study was partly supported by the Centre National de la Recherche Scientifique and the Institut Hospitalo-Universitaire Méditerranée Infection.
References
- Andersch I, Pianka S, Fritze D, Claus D. Description of Bacillus laevolacticus (ex Nakayama and Yanoshi 1967) sp. nov., nom. rev. Int J Syst Bacteriol. 1994;44:659–64. DOIGoogle Scholar
- Nakayama O, Yanoshi M. Spore-bearing lactic acid bacteria isolated from rhizosphere I. Taxonomic studies on Bacillus laevolacticus nov. sp. and Bacillus racemilacticus nov. sp. J Gen Appl Microbiol. 1967;13:139–53. DOIGoogle Scholar
- Morel A-S, Dubourg G, Prudent E, Edouard S, Gouriet F, Casalta J-P, Complementarity between targeted real-time specific PCR and conventional broad-range 16S rDNA PCR in the syndrome-driven diagnosis of infectious diseases. Eur J Clin Microbiol Infect Dis. 2015;34:561–70. DOIPubMedGoogle Scholar
- Mowlick S, Inoue T, Takehara T, Kaku N, Ueki K, Ueki A. Changes and recovery of soil bacterial communities influenced by biological soil disinfestation as compared with chloropicrin-treatment. AMB Express. 2013;3:46.
- Sawai H, Na K, Sasaki N, Mimitsuka T, Minegishi S, Henmi M, Membrane-integrated fermentation system for improving the optical purity of
d -lactic acid produced during continuous fermentation. Biosci Biotechnol Biochem. 2011;75:2326–32. DOIPubMedGoogle Scholar - Li Y, Wang L, Ju J, Yu B, Ma Y. Efficient production of polymer-grade d-lactate by Sporolactobacillus laevolacticus DSM442 with agricultural waste cottonseed as the sole nitrogen source. Bioresour Technol. 2013;142:186–91. DOIPubMedGoogle Scholar
- Gulati HK, Chadha BS, Saini HS. Production and characterization of thermostable alkaline phytase from Bacillus laevolacticus isolated from rhizosphere soil. J Ind Microbiol Biotechnol. 2007;34:91–8. DOIPubMedGoogle Scholar
- Wang H, Wang L, Ju J, Yu B, Ma Y. Genome sequence of Sporolactobacillus laevolacticus DSM442, an efficient polymer-grade
d -lactate producer from agricultural waste cottonseed as a nitrogen source. Genome Announc. 2013;1:e01100–13. - Seng P, Drancourt M, Gouriet F, La Scola B, Fournier P-E, Rolain JM, Ongoing revolution in bacteriology: routine identification of bacteria by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Clin Infect Dis. 2009;49:543–51. DOIPubMedGoogle Scholar
- Seng P, Abat C, Rolain JM, Colson P, Lagier J-C, Gouriet F, Identification of rare pathogenic bacteria in a clinical microbiology laboratory: impact of matrix-assisted laser desorption ionization-time of flight mass spectrometry. J Clin Microbiol. 2013;51:2182–94. DOIPubMedGoogle Scholar
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Cite This Article1These authors contributed equally to this article.
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Please use the form below to submit correspondence to the authors or contact them at the following address:
Jean-Marc Rolain, Unité de Recherche.sur les Maladies Infectieuses Tropicales Emergentes, UM 63, Centre National de la Recherche Scientifique 7278, Institut de Recherche pour le Développement 198, Institut National de la Santé et de la Recherche Médicale Unité 1095, Institut Hospitalo-Universitaire Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, 27 Blvd Jean Moulin, 13385 Marseille CEDEX 05, France
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