Molecular Analysis and Clinical Significance of Lactobacillus spp. Recovered from Clinical Specimens Presumptively Associated with Disease

Abstract

Veterans Administration Puget Sound Health Care System, Seattle, Washington, USA c Lactobacillus spp. are part of the normal human flora and are generally assumed to be nonpathogenic. We determined the genotypic identification of >100 Lactobacillus isolates from clinical specimens in the context of presumed pathogenic potential (e.g., recovered as the single/predominant isolate from a sterile site or at >10 5 CFU/ml from urine). This study assessed the clinical significance and the frequency of occurrence of each Lactobacillus sp. We identified 16 species of Lactobacillus by 16S rRNA gene sequence analysis, 10 of which could not be associated with disease. While Lactobacillus rhamnosus, Lactobacillus gasseri, and Lactobacillus paracasei were associated with infections, L. gasseri was also a common colonizing/contaminating species. Lactobacillus casei, Lactobacillus johnsonii, and Lactobacillus delbrueckii were associated with at least one infection. Species commonly used in probiotic products (e.g., L. rhamnosus and L. casei) were identical, by 16S rRNA gene sequencing, to our isolates associated with disease. Human isolates of Lactobacillus spp. have differing site associations and levels of clinical significance. Knowing the niche and pathogenic potential of each Lactobacillus sp. can be of importance to both clinical microbiology and the food and probiotic supplement industry.

Acute Cholecystitis Complicated with Gallbladder Perforation and Peritonitis Caused by Vancomycin-resistant Lactobacillus paracasei

“…Additionally, there are some differences in pathogenicity among the Lactobacillus spp. Lactobacillus paracasei, which was isolated from our patient's drain, along with Lactobacillus rhamnosus is mostly known to be associated with infections, whereas Lactobacillus gasseri can be both pathogenic and a colonizer, further supporting Lactobacillus paracasei as the primary pathogen in our patient's case [5].…”

An insight into intestinal mucosal microbiota disruption after stroke

“…2e ) 10 , found in post-stroke intestinal mucosa and lung is unclear. Although numerous Lactobacillus have been reported to cause opportunistic infections 36 , the elevation of Akkermansia in the post-stroke intestinal mucosa and lung may support Akkermansia -assisted healing of wound damage 13 , 14 , 37 , strengthen epithelial integrity 37 and control translocation. Therefore, further work to investigate the possible role of Akkermansia in post-stroke tissue repair may reveal novel functions.…”

A Rapidly Fatal Case of Lactobacillus Rhamnosus Sepsis Associated with Thyroid Storm in an Immunocompetent Patient

“…In a previous retrospective study, relationship between Lactobacillus spp. and the site from which the species was recovered was studied [18]. Of 19 blood culture isolates (17.7% of all lactobacilli isolated from different sites), seven (29%) were identified as L. rhamnosus.…”

“…Of 10 clinically significant cases of bacteremia due to Lactobacillus spp., L. rhamnosus (60%) was the most common species, which was found to be associated with an underlying disease such as esophageal carcinoma, pancreatitis, HIV, Crohn's disease etc. Interestingly, none of these patients was associated with infective endocarditis [18]. Lactobacillus bacteremia is a rare entity, and its clinical significance in immuno-competent patients is poorly defined [19].…”