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Year : 2021  |  Volume : 23  |  Issue : 2  |  Page : 82-84

Lactobacillus bacteraemia

Department of Microbiology Believers Church Medical College, Thiruvalla, Kerala, India

Date of Submission16-Jun-2021
Date of Decision16-Sep-2021
Date of Acceptance07-Dec-2021
Date of Web Publication27-Jan-2022

Correspondence Address:
Dr. Renu Mathew
Department of Microbiology, Believers Church Medical College, Thiruvalla - 689 103, Kerala
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jacm.jacm_54_21

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Lactobacilli exist as a commensal flora in the gastrointestinal tract and can be pathogenic once it is isolated from sterile sites such as bloodstream, spinal fluid and endocardial tissue. Here, we report a case of Lactobacillus bacteraemia in a patient who had many comorbidities.

Keywords: Bacteraemia, Lactobacillus, probiotics

How to cite this article:
Abraham SS, Thomas M, Mathew R, Jose RA, Goswami T, Jacob AA. Lactobacillus bacteraemia. J Acad Clin Microbiol 2021;23:82-4

How to cite this URL:
Abraham SS, Thomas M, Mathew R, Jose RA, Goswami T, Jacob AA. Lactobacillus bacteraemia. J Acad Clin Microbiol [serial online] 2021 [cited 2022 Jul 1];23:82-4. Available from: https://www.jacmjournal.org/text.asp?2021/23/2/82/336584

  Introduction Top

Lactobacillus is a group of probiotic bacteria, generally regarded as one of the 'friendly' bacteria while being part of the normal flora of oral cavity, gastrointestinal and the female genital tract. There are many species of Lactobacilli. However, it can be pathogenic once it is isolated from sterile sites such as bloodstream, spinal fluid and endocardial tissue. Despite their many beneficial roles in humans, they have the potential to translocate out of their normal environment and cause serious illness in some patients under certain circumstances. Here, we report a case of Lactobacillus bacteraemia in a patient who had many comorbidities such as underlying liver disease and diabetes mellitus.

  Case Report Top

A 67-year-old male was admitted with fever, chills and decreased urine output for a day. There was a history of decreased food intake and activity for the past five days. On examination, he was drowsy, not obeying commands and had right hemiparesis. He was a patient of Type 2 diabetes mellitus, cerebrovascular accident, hepatocellular carcinoma and decompensated chronic liver disease with portal hypertension and oesophageal varices. He gave a history of fracture femur and right hemiarthroplasty 2 years back. Routine blood examination revealed TC: 42,960/ul, altered renal function test —creatinine: 2.27 mg/dl and liver function test – elevated transaminases serum glutamic-oxaloacetic transaminase – 816 U/ml, serum glutamic pyruvic transaminase with hyperbilirubinemia, C-reactive protein: 150 mg/L and erythrocyte sedimentation rate 69 mm/h. Urine routine examination showed albuminuria and glycosuria. The patient was admitted to the medical intensive care unit on the same day and started on meropenem and levofloxacin after sending three samples of blood and urine for culture. The patient had two episodes of melaena during his stay in hospital. His condition deteriorated. The patient expired after developing desaturation, hypotension and bradycardia on the 8th day after admission.

All the three blood samples sent on the 1st day of admission grew slender Gram-positive bacilli. The urine culture was sterile. The blood agar plates grew tiny alpha-haemolytic colonies [Figure 1] under microaerophilic conditions. There was no growth on MacConkey agar. It was non-motile, non-sporing. Catalase test was negative, no H2S production on triple sugar iron slant and hydrolysed aesculin. It was resistant to vancomycin. The isolate was sent for identification by Matrix-Assisted Laser Desorption Ionisation–Time of Flight and was later identified as Lactobacillus casei.
Figure 1: Alpha-haemolytic colonies on blood agar

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  Discussion Top

Lactobacilli are Gram-positive, catalase-negative, non-spore bearing, aerobic or facultative anaerobic, rod-shaped bacteria. They are ubiquitous and inhabit a wide variety of habitats, including the gastrointestinal tract, oral cavity and vagina. Moreover, these bacteria are traditionally used in the manufacturing of fermented foods and as a probiotic. Although Lactobacilli are usually considered contaminants in blood cultures, they have been identified in some clinical reports as causal agents of dental caries, infectious endocarditis, urinary tract infections, chorioamnionitis, endometritis, meningitis, intra-abdominal, liver or spleen abscesses and bacteraemia.[1],[2],[3]

Lactobacilli exist in the gastrointestinal tract as a commensal flora and it is recognised that it enters the bloodstream through mucosal translocation. The presence of true Lactobacillus bacteraemia in a clinically deteriorating patient should prompt urgent evaluation of a pathology that facilitates this translocation such as colitis, pyelonephritis, endometritis and their underlying aetiologies. Lactobacillus rhamnosus and L. casei bacteraemia are associated with probiotic use[4] and are also the most common species isolated from bacteraemia.[1],[5] Cannon et al. have reported 30% mortality in such cases. Patients recently treated with immunosuppressive therapy or broad-spectrum antibiotics and those with diabetes, malignancy, organ transplants or indwelling venous catheters are at increased risk for symptomatic bacteraemia. Lactobacillus bacteraemia may be an important marker of disease severity rather than a pathogen, suggesting comorbidities.[1]

Our patient had oesophageal varices and inflamed mucosa that has been suggested as a means by which these bacteria reach the bloodstream.[6] Similar cases of bacteraemia following frequently consumed probiotic dietary products were reported by others also.[7] Although there was no history of intake of probiotics, in this case, the enquiry revealed that the patient used to consume a lot of cheese, yoghurt and other dairy products regularly. However, Lactobacillus bacteraemia has also been reported in cases with no probiotic use and no intestinal pathology.[2],[5] Altogether, these results suggest that probiotics are harmless for healthy patients, but they should be used with caution in patients presenting with pre-existing risk factors.[8]

Isolation of the Lactobacillus from multiple blood samples and another site of clinical infection suggests the presence of actual infection rather than contamination of blood cultures from skin flora or transient mucosal tissue-based bacteraemia.[9]

  Conclusion Top

Identification and reporting of Lactobacillus species from blood cultures is a challenge and can cause a delay in appropriate management. Although this is an uncommon pathogen, isolation of Lactobacillus from multiple blood cultures should not be discarded as contaminants but should lead physicians to screen for underlying diseases and a thorough understanding of possible portals to the bloodstream is needed.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Cannon JP, Lee TA, Bolanos JT, Danziger LH. Pathogenic relevance of Lactobacillus: A retrospective review of over 200 cases. Eur J Clin Microbiol Infect Dis 2005;24:31-40.  Back to cited text no. 1
Omar AM, Ahmadi N, Ombada M, Fuscaldo J, Siddiqui N, Safo M, et al. Breaking bad: A case of Lactobacillus bacteremia and liver abscess. J Community Hosp Intern Med Perspect 2019;9:235-9.  Back to cited text no. 2
Salminen MK, Rautelin H, Tynkkynen S, Poussa T, Saxelin M, Valtonen V, et al. Lactobacillus bacteremia, clinical significance, and patient outcome, with special focus on probiotic L. rhamnosus GG. Clin Infect Dis 2004;38:62-9.  Back to cited text no. 3
Kulkarni HS, Khoury CC. Sepsis associated with Lactobacillus bacteremia in a patient with ischemic colitis. Indian J Crit Care Med 2014;18:606-8.  Back to cited text no. 4
[PUBMED]  [Full text]  
Ambesh P, Stroud S, Franzova E, Gotesman J, Sharma K, Wolf L, et al. Recurrent Lactobacillus bacteremia in a patient with leukemia. J Investig Med High Impact Case Rep 2017;5:https://pubmed.ncbi.nlm.nih.gov/29204452/.  Back to cited text no. 5
Sherid M, Samo S, Sulaiman S, Husein H, Sifuentes H, Sridhar S. Liver abscess and bacteremia caused by Lactobacillus: Role of probiotics? Case report and review of the literature. BMC Gastroenterol 2016;16:138.  Back to cited text no. 6
Tommasi C, Equitani F, Masala M, Ballardini M, Favaro M, Meledandri M, et al. Diagnostic difficulties of Lactobacillus casei bacteraemia in immunocompetent patients: A case report. J Med Case Rep 2008;2:315.  Back to cited text no. 7
Franko B, Fournier P, Jouve T, Malvezzi P, Pelloux I, Brion JP, et al. Lactobacillus bacteremia: Pathogen or prognostic marker? Med Mal Infect 2017;47:18-25.  Back to cited text no. 8
Antony SJ, Stratton CW, Dummer JS. Lactobacillus bacteremia: Description of the clinical course in adult patients without endocarditis. Clin Infect Dis 1996;23:773-8.  Back to cited text no. 9


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