Lactobacillus endocarditis with prosthetic material: a case report on non-surgical management with corresponding literature review

Invasive lactobacillus infection in pediatric patients in a tertiary center in Taiwan - 16 years' experience and literature review

BACKGROUND

Lactobacilli are common microorganisms in the human body. Some species were used as probiotics supplement for many purposes such as preventing necrotizing enterocolitis, or improving allergic diseases or diarrhea. Previously, Lactobacillus infection was thought of as contamination due to its low pathogenicity. However, there have been reports of invasive Lactobacillus infection in immunocompromised patients or patients with comorbidities. The purpose of this study was to analyze the clinical characteristics, antibiotic treatment and outcomes of pediatric patients with invasive Lactobacillus infection.

METHODS

We retrospectively reviewed pediatric patients diagnosed with invasive Lactobacillus infection between 2004 and 2020. Invasive Lactobacillus infection was diagnosed if sterile sites yielded Lactobacillus spp. Clinical manifestations, chronic diseases, potential predisposing factors, medical treatments, antimicrobial susceptibility tests and outcomes were recorded.

RESULTS

Fifteen pediatric patients were diagnosed with invasive Lactobacillus infection, accounting for 2.4% of total invasive Lactobacillus infections during the 16-year period. Eleven infections were bacteremia, two were intra-abdominal infections, and two were biliary tract infections. Fever was the most common symptom. Potential predisposing factors were immunocompromised status, central venous device, prolonged antibiotics use and receiving supplemented probiotics for at least one week. All patients survived with favorable outcomes. Most pathogens were identified as Lactobacillus spp, and two were Lactobacillus rhamnosus, which were related to supplemented probiotics. The antimicrobial susceptibility tests showed that Lactobacilli were all sensitive to ampicillin but resistant to glycopeptides.

CONCLUSION

Invasive Lactobacillus infections in pediatric patients were rare. Despite its low pathogenicity, Lactobacillus could cause invasive infection in those immunocompromised patients.

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.

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.

Safety of Probiotics: Functional Fruit Beverages and Nutraceuticals

Over the last decade, fruit juice consumption has increased. Their rise in popularity can be attributed to the belief that they are a quick way to consuming a dietary portion of fruit. Probiotics added to fruit juices produce various bioactive compounds, thus probiotic fruit juices can be considered as a new type of functional foods. Such combinations could improve nutritional properties and provide health benefits of fruit juices, due to delivering positive health attributes from both sources (fruit juices and probiotics). However, this review discusses the other side of the same coin, i.e., the one that challenges general beliefs that probiotics are undoubtedly safe. This topic deserves more acknowledgments from the medical and nutritional literature, as it is highly important for health care professionals and nutritionists who must be aware of potential probiotic issues. Still, clinical trials have not adequately questioned the safety of probiotics, as they are generally considered safe. Therefore, this reviews aims to give an evidence-based perspective of probiotic safety, focusing on probiotic fruit beverages and nutraceuticals, by providing documented clinical case reports and studies. Finally, the paper deals with some additional insights from the pharmacological and toxicological point of views, such as pharmacological repercussions of probiotics on health.

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.

Members of the Lactobacillus Genus Complex (LGC) as Opportunistic Pathogens: A Review

Microorganisms belonging to the Lactobacillus genus complex (LGC) are naturally associated or deliberately added to fermented food products and are widely used as probiotic food supplements. Moreover, these bacteria normally colonize the mouth, gastrointestinal (GI) tract, and female genitourinary tract of humans. They exert multiple beneficial effects and are regarded as safe microorganisms. However, infections caused by lactobacilli, mainly endocarditis, bacteremia, and pleuropneumonia, occasionally occur. The relevance of Lactobacillus spp. and other members of the LGC as opportunistic pathogens in humans and related risk factors and predisposing conditions are illustrated in this review article with more emphasis on the species L. rhamnosus that has been more often involved in infection cases. The methods used to identify this species in clinical samples, to distinguish strains and to evaluate traits that can be associated to pathogenicity, as well as future perspectives for improving the identification of potentially pathogenic strains, are outlined.