Lactobacillus rhamnosus Infection: A Single-center 4-year Descriptive Analysis

A case report of lactobacillus bacteremia in a patient on chronic parenteral nutrition

BACKGROUND AND AIMS

Short bowel syndrome is a malabsorption disorder typically caused by the physical loss of a portion of the intestine, whereafter the body is unable to adequately absorb nutrients, fluids, and electrolytes. Many patients with short bowel syndrome are reliant on home parenteral nutrition through a tunneled or peripherally inserted central catheter to ensure sufficient hydration and nutrition. Central venous catheters are a nidus for bacteria, and patients are at risk for infections associated with high levels of morbidity and mortality. Lactobacillus is a ubiquitous microorganism that most frequently colonizes mucosal surfaces such as the gastrointestinal tract. Lactobacillus bacteremia is rare, with limited occurrence in current medical literature.

METHODS

Our patient is a 60-year-old female with a past medical history significant for multiple abdominal surgeries resulting in short bowel syndrome, with subsequent dependence on home parenteral nutrition via peripherally inserted central catheter. She had type III chronic intestinal failure, category D2, and stage 1 moderate malnutrition. She was originally admitted to the hospital for a presumed pulmonary embolism and was found to have a deep vein thrombosis in the setting of her peripherally inserted central catheter. On admission her abdominal exam was unremarkable, she denied abdominal pain, and her only gastrointestinal complaint was chronic stable diarrhea. During the hospitalization she developed severe left lower quadrant abdominal pain and noted decreased frequency of her bowel movements. A computed tomography scan of her abdomen revealed chronic stable intestinal distension and was concerning for obstruction. Clinically she remained without symptoms of acute obstruction or ileus. During the admission she became febrile, with blood cultures from her peripherally inserted central catheter and peripheral IV growing out gram negative rods determined to be lactobacillus bacteremia. The infectious disease team recommended removal of her peripherally inserted central catheter given their concern for a line infection.

RESULTS

The patient was treated with broad-spectrum antibiotics, did well clinically, and was ultimately discharged following reinsertion of her peripherally inserted central catheter after negative repeat blood cultures. Though she initially did well in the outpatient setting, she ultimately passed away ten months later after re-presenting to the hospital in septic shock, secondary to bowel ischemia and suspected fungemia of her peripherally inserted central catheter.

CONCLUSIONS

In this case report, we describe an unusual case of a patient with short bowel syndrome on chronic parenteral nutrition who developed catheter-associated lactobacillus bacteremia - the first reported case in an adult patient on parenteral nutrition.

Ameliorative effects of probiotics in AlCl3-induced mouse model of Alzheimer's disease

In recent years, gut microbiome alterations have been linked with complex underlying mechanisms of neurodegenerative disorders including Alzheimer's disease (AD). The gut microbiota modulates gut brain axis by facilitating development of hypothalamic-pituitary-adrenal axis and synthesis of neuromodulators. The study was designed to unravel the effect of combined consumption of probiotics; Lactobacillus rhamnosus GG (LGG®) and Bifidobacterium BB-12 (BB-12®) (1 × 109 CFU) on AlCl3-induced AD mouse model in comparison with potent acetylcholine esterase inhibitor drug for AD, donepezil. Mice were randomly allocated to six different study groups (n = 8). Behavioral tests were conducted to assess effect of AlCl3 (300 mg/kg) and probiotics treatment on cognition and anxiety through Morris Water Maze (MWM), Novel Object Recognition (NOR), Elevated Plus Maze (EPM), and Y-maze. The results indicated that the combined probiotic treatment significantly (p < 0.0001) reduced anxiety-like behavior post AlCl3 exposure. The AlCl3 + LGG® and BB-12®-treated group showed significantly improved spatial (p < 0.0001) and recognition memory (p < 0.0001) in comparison to AlCl3-treated group. The expression status of inflammatory cytokines (TNF-α and IL-1β) was also normalized upon treatment with LGG® and BB-12® post AlCl3 exposure. Our findings indicated that the probiotics LGG® and BB-12® have strong potential to overcome neuroinflammatory imbalance, cognitive deficits and anxiety-like behavior, therefore can be considered as a combination therapy for AD through modulation of gut brain axis. KEY POINTS: • Bifidobacterium BB-12 and Lactobacillus rhamnosus GG were fed to AlCl3-induced Alzheimer's disease mice. • This combination of probiotics had remarkable ameliorating effects on anxiety, neuroinflammation and cognitive deficits. • These effects may suggest that combined consumption of these probiotics instigate potential mitigation of AD associated consequences through gut brain axis modulation.

Lactobacillus rhamnosus a cause of Gram-positive rods bacteremia after prophylactic probiotic consumption

•Lactobacillus rhamnosus bacteremia was diagnosed in a patient with radiation enteritis after prophylactic probiotic consumption.•L. rhamnosus was identified by culture and MALDI-TOF-MS.•L. rhamnosus may have high MIC values for amoxicillin.•In case of L. rhamnosus bacteremia, bowel diseases should be considered as a possible source of infections.

Probiotic-based nanoparticles for targeted microbiota modulation and immune restoration in bacterial pneumonia

While conventional bacterial pneumonia mainly centralizes avoidance of bacterial colonization, it remains unclear how to restore the host immunity for hyperactive immunocompetent primary and immunocompromised secondary bacterial pneumonia. Here, probiotic-based nanoparticles of OASCLR were formed by coating chitosan, hyaluronic acid and ononin on living Lactobacillus rhamnosus. OASCLR nanoparticles could effectively kill various clinic common pathogens and antibacterial efficiency was >99.97%. Importantly, OASCLR could modulate lung microbiota, increasing the overall richness and diversity of microbiota by decreasing pathogens and increasing probiotic and commensal bacteria. Additionally, OASCLR could target inflammatory macrophages by the interaction of OASCLR with the macrophage binding site of CD44 and alleviate overactive immune responses for hyperactive immunocompetent pneumonia. Surprisingly, OASCLR could break the state of the macrophage's poor phagocytic ability by upregulating the expression of the extracellular matrix assembly, immune activation and fibroblast activation in immunocompromised pneumonia. The macrophage's phagocytic ability was increased from 2.61% to 12.3%. Our work provides a potential strategy for hyperactive immunocompetent primary and immunocompromised secondary bacterial pneumonia.

Lactobacilli Infection Case Reports in the Last Three Years and Safety Implications

Lactobacilli constitute the dominant microbiota in many fermented foods and comprise widely used probiotics. However, these bacteria cause rare infections mostly in diabetic and immunocompromised subjects in presence of risk factors such as prosthetic hearth valves and dental procedures or caries. The scope of this survey was re-assessing the pathogenic potential of lactobacilli based on the infection case reports published in the last three years. In 2019, 2020, and 2021, total of 17, 15, and 16 cases, respectively, including endocarditis, bacteremia, and other infections, were reported. These annual numbers are higher than those observed previously. Lacticaseibacillus rhamnosus (13 cases), comprising strain GG (ATCC 53103) with established applications in healthcare, L. paracasei (7 cases), Lactobacillus acidophilus (5 cases), L. jensenii (5 cases), Lactiplantibacillus plantarum (3 cases), L. paraplantarum, L. delbrueckii subsp. delbrueckii, L. gasseri, L. paragasseri, Limosilactobacillus fermentum, and L. reuteri (1 case each) were involved. Virulence characterization of two strains that caused infections, a derivative of L. rhamnosus GG and L. paracasei LP10266, indicated that increased biofilm-forming capacity favors pathogenicity and it is determined by variable genetic traits. This survey highlights that the strains of lactobacilli that cause infections are little characterized genetically. Instead, to avoid that these bacteria become a hazard, genetic stability should be periodically re-evaluated by whole genome sequencing (WGS) to ensure that only non-pathogenic variants are administered to vulnerable individuals.