Stool microbiota analysis for abundance of genus Klebsiella among adults and children in endemic area for community Klebsiella pneumoniae infection

Background

Invasive Klebsiella pneumoniae syndrome is a significant endemic disease in Taiwan. Intestinal colonization of virulent clones that cause this phenomenon has been demonstrated in asymptomatic adults. Comparisons of healthy adults and children with stool K. pneumoniae colonization have rarely been reported. We aimed to evaluate the frequency and abundance of K. pneumoniae in the stool of adults and children by stool microbiota analysis.

Methods

Healthy volunteers and their children without antibiotic exposure within 3 months were recruited in a Taiwanese medical center. Stool samples were sent for gut microbiota analysis, using amplification of V3–V4 hypervariable regions of 16sRNA followed by high-throughput sequence. Rectal/stool swabs were sent for K. pneumoniae culture and identification by matrix-assisted laser desorption ionization–time-of-flight mass spectrometry (MALDI-TOF MS).

Results

Fifty-five adults with a mean age of 46.9 years (range, 23.1–72.1 years) and 20 children with a mean age of 2.3 years (range, 0.9–5.8) were enrolled, and 29 adults and 6 children had positive K. pneumoniae swabs. Children had lower microbiota diversity than adults, including higher abundance of phylum Actinobacteria and Proteobacteria, and lower Bacteriodetes. For genus comparison, higher abundance of Escherichia, Streptococcus, Enterococcus and Bifidobacterium were found in children, but the composite abundance of Klebsiella in adults (median: 0.0156, range: 0–0.031) and in children (median: 0.0067, range: 0–0.043) were similar. Klebsiella abundance was significantly higher in participants with positive swabs (p < 0.0001). Klebsiella-positive swabs were strongly negatively correlated with Enterobacter spp. (p < 0.0001), but no known demographic factors correlated with Klebsiella-positive swabs.

Conclusion

Klebsiella species are present in young children, and the abundance is similar in adults and children. Positive swabs correlate strongly with higher abundance in microbiota analysis.