Infective endocarditis caused by lactobacillus

Infective Endocarditis by Lactobacillus Species-A Narrative Review

Bacteria of the genus Lactobacillus are microaerophilic or aerotolerant anaerobic Gram-positive non-spore-forming rods. They are considered essential members of the human gut microbiome; however, recent studies have revealed that these microorganisms are less predominant in the gut microbiome than initially thought. Lactobacillus spp. is mainly known for its use as a probiotic in foods and supplements to prevent and treat specific issues such as infectious diseases, irritable bowel syndrome, and diabetes mellitus. However, Lactobacillus spp. may occasionally cause infections such as bacteremia or infective endocarditis (IE). The present study aimed to review all cases of IE by Lactobacillus spp. and describe the epidemiology, microbiology, clinical characteristics, treatment, and outcomes of this infection by collecting relevant data from studies existing in Pubmed and Scopus until 28 September 2023. A total of 77 studies containing data for 82 patients were included. The median age was 56 years, and 69.6% were male. A prosthetic valve was present in 16% of patients, and 17.3% had previously been on probiotics. The aortic valve was the most commonly involved intracardiac site, followed by the mitral valve. Fever, embolic phenomena, sepsis, and heart failure were the most common clinical presentations. Aminoglycosides and penicillin were the most commonly used antimicrobials for definitive treatment. Surgery was performed in 53.7% of patients. Overall mortality was 17.1%. IE in prosthetic valves and presentation with shock were independently associated with overall mortality.

Safety Evaluation of Goat Milk Added with the Prebiotic Inulin Fermented with the Potentially Probiotic Native Culture Limosilactobacillus mucosae CNPC007 in Co-culture with Streptococcus thermophilus QGE: Analysis of Acute and Repeated Dose Oral Toxicity

Despite functional goat milk products having emerged due to their importance for human nutrition and health, few studies have assessed the safety of consumption of goat dairy products containing potentially probiotic autochthonous lactic acid bacteria supplemented with prebiotic carbohydrates. Aiming this field, this study evaluated the safety of goat's milk fermented with Streptococcus thermophilus QGE, the autochthonous Limosilactobacillus mucosae CNPC007 culture, and the prebiotic inulin, through single- and repeated-dose oral toxicity tests (SDT and RDT, respectively) in animals. Ten female Swiss Webster mice were used for SDT evaluation - 2 groups, SDTc (20 mL/kg of filtered water) and SDTt (20 mL/kg of fermented milk) - and 40 Wistar rats for RDT - RDT3, RDT6, and RDT12 (treated with fermented milk at doses of 3 mL/kg, 6 mL/kg, and 12 mL/kg, respectively) and also RDTc (12 mL/kg of filtered water). For SDT, no signs of mortality or toxicity were observed, and the animals maintained the expected weight gain and feed intake. The RDT trials did not show mortality or signs of toxicity, as well as no change in body weight and organs, in the hematological and biochemical parameters, and also in relation to morphology and histology. Since the fermented milk did not cause any toxic effect in the conditions evaluated, it can be said that its no-adverse effect level (NOAEL) was considered to be higher than 20 mL/kg/day. Thus, the fermented milk with L. mucosae CNPC007 and inulin was considered to be of low toxicity, safe for use in rodents, and allowed for use in further studies.

Fatal Lactobacillus endocarditis in a patient with transcatheter aortic valve replacement

Lactobacillus species may translocate from the gastrointestinal tract into systemic circulation from ingested probiotics or commensal flora. Their pathogenic potential is still debated. Lactobacillus endocarditis is a rare entity with only around 120 cases reported in the literature. Here, we report the first case of fatal Lactobacillus endocarditis with involvement of a transcatheter aortic valve replacement with the following goals: to reaffirm the pathological significance of Lactobacillus spp, to demonstrate the potential limitations of the modified Duke criteria in diagnosing infective endocarditis of transcatheter aortic valve replacement, and to urge clinicians to aggressively search for and consider empiric treatment for endocarditis in patients with prosthetic valves who develop Lactobacillus bacteraemia.

Lactobacillus endocarditis: a case report in France and literature review

Lactobacilli are commensal bacteria in the normal flora of the oral cavity, gastrointestinal and genital tract. However, few cases of lactobacilli-induced bacteremia or endocarditis have been reported, particularly in immunocompromised patients. We reported a rare case of a 57-year-old man with a Lactobacillus rhamnosus endocarditis without immunodeficiency in his medical history. He received a dental scaling one year before. Clinical presentation included weight loss, heart murmur, ankle arthritis and splinter hemorrhage. Echocardiography showed a mitral prolapse and a 16 mm vegetation associated with a valvular perforation. All blood cultures were positive for Lactobacillus rhamnosus. Antibacterial regimen with amoxicillin and gentamicin led to recovery without surgery. We present a literature review of the lactobacillary endocarditis cases published since 1992. Valvulopathy, dental or invasive procedures and probiotics use were the main underlying conditions, in contrary to immunodeficiency. Diagnosis of lactobacillary endocarditis should be more considered and a treatment with penicillin and aminoglycoside should be promptly introduced in life-threatening cases.

Probiotic supplements might not be universally-effective and safe: A review

Last few decades have witnessed the unprecedented growth in the application of probiotics for promoting the general gut health as well as their inception as biotherapeutics to alleviate certain clinical disorders related to dysbiosis. While numerous studies have substantiated the health-restoring potentials for a restricted group of microbial species, the marketed extrapolation of a similar probiotic label to a large number of partially characterized microbial formulations seems biased. In particular, the individuals under neonatal stages and/or those with some clinical conditions including malignancies, leaky gut, diabetes mellitus, and post-organ transplant convalescence likely fail to reap the benefits of probiotics. Further exacerbating the conditions, some probiotic strains might take advantage of the weak immunity in these vulnerable groups and turn into opportunistic pathogens engendering life-threatening pneumonia, endocarditis, and sepsis. Moreover, the unregulated and rampant use of probiotics potentially carry the risk of plasmid-mediated antibiotic resistance transfer to the gut infectious pathogens. In this review, we discuss the safety perspectives of probiotics and their therapeutic interventions in certain at-risk population groups. The embodied arguments and hypotheses certainly will shed light on the fact why probiotic usage should be treated with caution.

Endocarditis of the native aortic valve caused by Lactobacillus jensenii

Lactobacilli are Gram-positive anaerobic rods or coccobacilli, commonly found as commensals in human mucosa. Rarely, they can cause serious infections such as infective endocarditis (IE), and the most frequently implicated species causing serious infections are L. casei and L. rhamnosus. IE caused by Lactobacillus jensenii is very rare, with only six reported cases so far, to the best of our knowledge. We present a case of native aortic valve endocarditis caused by L. jensenii, complicated by root abscess and complete heart block, and requiring emergent surgical intervention.

Successful two-stage revision of Lactobacillus infection of a total knee arthroplasty and literature review

BACKGROUND

Lactobacillus has been identified as the causative organism in only two total joint arthroplasties: one total hip arthroplasty (THA) and one total knee arthroplasty (TKA). The THA was a litigious case that was treated successfully with a one-stage revision, and the patient with the TKA ultimately required above-knee amputation. We present the first case report of a Lactobacillus infection of a TKA that was treated successfully with a two-stage revision TKA.

METHODS

Case report and literature review.

CASE REPORT

While undergoing a revision left TKA for persistent pain, a 55-year-old Caucasian female was found to have a Lactobacillus infection by intra-operative culture. After an extended course of intravenous (IV) antibiotics, the patient underwent a successful two-stage revision of her prosthesis.

CONCLUSION

Lactobacillus has been appearing more frequently in the literature as a pathogen in patients with compromised immune systems. Orthopedic implant infection with Lactobacillus has only been reported twice, with poorly defined treatment regimens and inconsistent results in both cases. The present report provides orthopedic surgeons and infectious diseases specialists with a treatment algorithm consisting of a two-stage revision of a TKA and a second-line IV antibiotic regimen that may be able to eradicate a Lactobacillus infection of an orthopedic prosthesis with retention of the extremity containing the implant and re-implantation of a functioning prosthesis.

Descending necrotizing mediastinitis associated with Lactobacillus plantarum

Background

Descending necrotizing mediastinitis (DNM), a severe infection with a high fatality rate, develops in mediastinal spaces due mainly to deep cervical abscesses. The majority of causative microbes of DNM are Streptococci and oral anaerobes. DNM associated with Lactobacillus-infection is rather rare.

Case presentation

A 69-year-old male with an unremarkable past medical history was referred to our hospital for surgical resection of advanced laryngeal cancer. Full examination revealed a neck abscess and DNM with a background of untreated diabetes mellitus. Initially, he was treated with meropenem. However, Lactobacillus plantarum was isolated from surgical drainage of a mediastinal abscess. Despite using antibiotics capable of eradicating all isolates with susceptibilities not differing significantly from those of the neck and mediastinal abscesses, we attributed DNM to the L. plantarum detected only in the mediastinal abscess. After DNM treatment, he underwent total pharyngolaryngectomy with bilateral neck dissection followed by reconstruction using free jejunum. He was discharged fully recovered.

Conclusion

We concluded that L. plantarum as the sole cause of the mediastinal abscess in the present case cannot be ruled out. As the number of immunocompromised patients increases, we should be cautious regarding this “familiar” microbe.

Lactobacillus rhamnosus bacteremia: an emerging clinical entity

Lactobacillus spp. are ubiquitous commensals of the normal human flora that are only occasionally found in clinical infections. Their role in human disease is established for infectious endocarditis but is controversial for other infections. We sought to characterize clinically associated Lactobacillus spp. We conducted a retrospective study, which consisted of the screening of Lactobacillus isolates obtained in our laboratory from January 2004 to December 2009. The polymerase chain reaction (PCR) assay was selected as the gold standard method. The isolates were first identified using API Coryne strips, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 16S rRNA gene sequencing. Lactobacillus tuf gene-based identification was used when the 16S rRNA results were inconclusive. Among the 60 strains of Lactobacillus spp. obtained in our laboratory, L. rhamnosus was the most commonly isolated species and was found in blood cultures from 16 patients. Combined with 45 patients reported in the literature, we found that patients presenting with L. rhamnosus bacteremia experienced nosocomial infections associated with both immunosuppression (66 %) and catheters (83 %).