In this study, 12 strains of Akkermansia muciniphila were isolated and characterized from healthy volunteers from different regions of Xinjiang Uygur Autonomous Region, China. Through whole-genome phylogenetic analysis, the genetic differences among these strains were compared. Their genome sizes ranged from 2.64 to 2.98 Mb, with GC contents between 55.1% and 55.7%. According to the phylogenetic tree constructed based on average nucleotide identity (ANI) and core genes, we categorized all isolates into three distinct subgroups. The results indicated that subgroup Ⅱ exhibited the highest acid and bile salt tolerance, with aggregation rates > 60% after 48 h and hydrophobicity of (32.00 ± 0.02)% after 15 min. This subgroup also had superior radical scavenging capacity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical. Hemolysis assays showed no significant hemolytic rings, indicating that all strains were safe for short-term usage. All strains were resistant to aminoglycoside antibiotics (streptomycin and gentamicin) and susceptible to glycopeptide antibiotics (vancomycin). The antibiotic resistance phenotype results were not completely consistent with the gene detection results. Genomic sequencing identified the glycoside hydrolase families 2 (GH2) and 20 (GH20). Carbon source utilization analyses indicated that galactooligosaccharides, soybean oligosaccharides, and xylitol synergistically promoted the proliferation of A. muciniphila. Taken together, subgroup Ⅱ strains exhibit great potential for use as probiotics.

In this study, a combination of an improved mucin enriched medium with real-time polymerase chain reaction (real-time PCR) was used to test 48 samples of maternal and infant feces for Akkermansia muciniphila (Akk). Under optimized conditions, 24 Akk strains were isolated from eight positive samples. All these strains were confirmed as Akk by 16S rRNA gene sequencing and PCR with Akk-specific primers. Repetitive extragenic palindrome-polymerase chain reaction (rep-PCR) fingerprinting classified the 24 strains into four genotypic groups. Subsequently, these strains were tested in vitro for simulated gastrointestinal fluid tolerance, hydrophobicity, antibiotic susceptibility, and glycan utilization capacity. The results showed that strains HN18D-1, HN18D-3, and WW48D1-13 had the highest tolerance to simulated gastric and intestinal fluids. All Akk strains were resistant to vancomycin, clindamycin, kanamycin and erythromycin. Xylooligosaccharides and soybean oligosaccharides had prebiotic effects on the Akk strains. Collectively, Akk isolates HN18D-1, HN18D-3 and WW48D1-13 can be used as potential probiotic candidates for subsequent in-depth studies.