A curious case of Lactobacillus casei in a prosthetic joint: was it the yogurt?

Lactobacillus cell-free supernatant as a novel bioagent and biosurfactant against Pseudomonas aeruginosa in the prevention and treatment of orthopedic implant infection

The hypothesis was that probiotic Lactobacillus species (spp.) or their cell-free supernatant (CFS) are effective in inhibiting (a) planktonic growth of Pseudomonas aeruginosa (PA), (b) its adhesion to a Ti6Al4V-alloy surface, and (c) in dispersing biofilm once formed. (a) A planktonic co-culture containing PA(10⁴  colony-forming unit [CFU]/ml) was combined with either Lactobacillus acidophilus, Lactobacillus plantarum (LP), or Lactobacillus fermentum (LF) at a suspension of 10⁴ (1:1) or 10⁸  CFU/ml (1:2). Lactobacillus and PA CFUs were then quantified. (b) Ti-6Al-4V discs were inoculated with PA followed by supplementation with CFS and adherent PA quantified. (c) Biofilm covered discs were supplemented with Lactobacillus CFS and remaining PA activity quantified. Results showed that whole-cell cultures were ineffective in preventing PA growth; however, the addition of CFS resulted in a 99.99 ± 0.003% reduction in adherent PA in all Lactobacillus groups (p < .05 in all groups) with no viable PA growth measured in the LF and LP groups. Following PA biofilm formation, CFS resulted in a significant reduction in PA activity in all Lactobacillus groups (p ≤ .05 in all groups) with a 29.75 ± 15.98% increase measured in control samples. Supplementation with CFS demonstrated antiadhesive, antibiofilm, and toxic properties to PA.

Remote transient Lactobacillus animalis bacteremia causing prosthetic hip joint infection: a case report

Background

Lactobacillus spp. are uncommon pathogens in immunocompetent hosts, and even rarer causes of prosthetic device infections.

Case presentation

A case of chronic hip prosthetic joint infection (PJI) caused by L. animalis is described. This occurred 5 years after a transient bacteremia with the same organism. Whole genome sequencing of both isolates proved this PJI infection resulted from this remote bacteremia.

Conclusions

We document that prosthetic joint infections may be a consequence of bacteremia as much as 3 years before the onset of symptoms.

Identification of silent prosthetic joint infection: preliminary report of a prospective controlled study

Purpose

We will test the hypothesis that ultrasound supported by polymerase chain reaction (PCR) could improve bacterial identification in non-infected prosthetic joint loosening. The aim was to detect bacterial species in non-infected prosthetic joint loosening using ultrasound and 16S rRNA gene sequencing.

Methods

A total of 16 patients (11 women and five men) aged 46–80 years (mean age 65.7) with diagnosed knee or hip implant loosening (mean implant survival of 102.1 months) were investigated. Bacterial culture and DNA sequencing were used to detect bacteria on the surface of failed implants removed during revision arthroplasty. The results of pre- and intraoperative culture and DNA sequencing were compared. Histopathological analysis was also performed.

Results

The number of positive cultures rises with a higher level of C-reactive protein (CRP). The results of the cultures from synovial fluid obtained through joint aspiration were consistent with sonicates from components of prostheses in 12 cases (75 %). Bacterial DNA was found in 90 % of patients with negative synovial fluid culture. PCR revealed two or more bacterial species, often of the same genus: Ralstonia pickettii, Pseudomonas spp., Brevibacterium spp., Lactobacillus spp., Propionibacterium spp. and Staphylococcus spp.These are micro-organisms present in the environment or on the human body and often associated with compromised immunity.

Conclusions

The ultrasound procedure followed by PCR and sequencing improve bacterial identification in silent prosthetic joint infection. The lack of clinical signs of infection and negative preoperative and intraoperative cultures do not exclude the presence of micro-organisms on the implants.