Objective:To investigate the mechanism of 6-sialyllactose (6-SL) in interfering the immune checkpoint inhibitor-induced colitis (ICIC) through the bacterial 16S rDNA sequencing.Methods:BALB/c mice were randomly divided into the normal control (NC) group ( n = 7), dextran sulfate sodium (DSS) group ( n = 6), ICIC group ( n = 6), and ICIC+6-SL group ( n = 6). The DSS group was continuously fed with 3.5% DSS drinking water for 7 days to induce colonic inflammation; the ICIC group was administered cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4, 150 μg) intraperitoneally on days 0 and 4 in addition to 3.5% DSS drinking water to establish the ICIC mouse model; the ICIC+6-SL group was given 6-SL [150 mg/ (kg·d) ] by gavage simultaneously with the establishment of the ICIC model. Changes in mouse body weight and disease activity index (DAI) were statistically analyzed, and all mice were sacrificed on day 7 to observe gross and histopathological morphological changes in the colon and to tally histopathological scores; the fresh colonic feces were collected for 16S rDNA sequencing to statistically analyze the diversity and species differences in the microbiota of mice of each group. Results:The success rate of the ICIC model was 100%, with all mice surviving. At the endpoint of the study (day 7), compared with the NC and DSS groups, the ICIC group had lower mouse body weight ( P < 0.05), higher DAI ( P < 0.05), damaged integrity of colonic mucosal tissue, and typical ulcerative lesions; the ICIC+6-SL group showed significant alleviation of body weight loss, significantly lower DAI scores, and lower pathological scores compared to the ICIC group, with all differences being statistically significant (all P < 0.05). 16S rDNA sequencing of mouse intestinal feces indicated that the alpha diversity of colonic microbiota in the ICIC group was lower than that in the NC and DSS groups (both P < 0.05), while the ICIC+6-SL group had higher alpha diversity than the ICIC group ( P < 0.05). In beta diversity analysis, the ANOSIM statistical value R = 0.376, P = 0.001 for the PCoA analysis of colonic microbiota and a Stress value of 0.125, P = 0.001 for the NMDS analysis indicated differences in the composition of colonic microbiota among the groups, with the greatest difference between the NC and ICIC groups, and the ICIC+6-SL group's microbiota composition was closer to that of the NC group compared to the ICIC group. Lefse analysis and Kruskal-Wallis test-based differential microbiota analysis showed that at the phylum level, compared to the NC group, the abundance of Bacteroidetes was significantly reduced in the ICIC group, while Campilobacterota was increased, and 6-SL administration could increase the abundance of Bacteroidetes and Campilobacterota in the ICIC group. At the genus level, compared to other groups, the abundance of unclassified_f_Lachnospiraceae and norank_f_Muribaculaceae was the lowest in the ICIC group, while Helicobacter, Akkermansia, and Escherichia-Shigella were enriched. Compared to the ICIC group, the abundance of unclassified_f_Lachnospiraceae and norank_f_ Muribaculaceae was increased in the ICIC+6-SL group, while the abundance of Helicobacter and Escherichia-Shigella was significantly suppressed. Conclusions:6-SL, an oligosaccharide derived from human milk, alleviates intestinal inflammatory injury in ICIC mice, reducing disease activity. This beneficial effect may be related to its regulation of gut microbiota profiling, an increased diversity of microbiota, a restoration of Bacteroidetes, and an inhibition of the growth advantage of pathogenic bacteria such as Helicobacter and Escherichia-Shigella.

Objective:To investigate the mechanism of 6-sialyllactose (6-SL) in interfering the immune checkpoint inhibitor-induced colitis (ICIC) through the bacterial 16S rDNA sequencing.Methods:BALB/c mice were randomly divided into the normal control (NC) group ( n = 7), dextran sulfate sodium (DSS) group ( n = 6), ICIC group ( n = 6), and ICIC+6-SL group ( n = 6). The DSS group was continuously fed with 3.5% DSS drinking water for 7 days to induce colonic inflammation; the ICIC group was administered cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4, 150 μg) intraperitoneally on days 0 and 4 in addition to 3.5% DSS drinking water to establish the ICIC mouse model; the ICIC+6-SL group was given 6-SL [150 mg/ (kg·d) ] by gavage simultaneously with the establishment of the ICIC model. Changes in mouse body weight and disease activity index (DAI) were statistically analyzed, and all mice were sacrificed on day 7 to observe gross and histopathological morphological changes in the colon and to tally histopathological scores; the fresh colonic feces were collected for 16S rDNA sequencing to statistically analyze the diversity and species differences in the microbiota of mice of each group. Results:The success rate of the ICIC model was 100%, with all mice surviving. At the endpoint of the study (day 7), compared with the NC and DSS groups, the ICIC group had lower mouse body weight ( P < 0.05), higher DAI ( P < 0.05), damaged integrity of colonic mucosal tissue, and typical ulcerative lesions; the ICIC+6-SL group showed significant alleviation of body weight loss, significantly lower DAI scores, and lower pathological scores compared to the ICIC group, with all differences being statistically significant (all P < 0.05). 16S rDNA sequencing of mouse intestinal feces indicated that the alpha diversity of colonic microbiota in the ICIC group was lower than that in the NC and DSS groups (both P < 0.05), while the ICIC+6-SL group had higher alpha diversity than the ICIC group ( P < 0.05). In beta diversity analysis, the ANOSIM statistical value R = 0.376, P = 0.001 for the PCoA analysis of colonic microbiota and a Stress value of 0.125, P = 0.001 for the NMDS analysis indicated differences in the composition of colonic microbiota among the groups, with the greatest difference between the NC and ICIC groups, and the ICIC+6-SL group's microbiota composition was closer to that of the NC group compared to the ICIC group. Lefse analysis and Kruskal-Wallis test-based differential microbiota analysis showed that at the phylum level, compared to the NC group, the abundance of Bacteroidetes was significantly reduced in the ICIC group, while Campilobacterota was increased, and 6-SL administration could increase the abundance of Bacteroidetes and Campilobacterota in the ICIC group. At the genus level, compared to other groups, the abundance of unclassified_f_Lachnospiraceae and norank_f_Muribaculaceae was the lowest in the ICIC group, while Helicobacter, Akkermansia, and Escherichia-Shigella were enriched. Compared to the ICIC group, the abundance of unclassified_f_Lachnospiraceae and norank_f_ Muribaculaceae was increased in the ICIC+6-SL group, while the abundance of Helicobacter and Escherichia-Shigella was significantly suppressed. Conclusions:6-SL, an oligosaccharide derived from human milk, alleviates intestinal inflammatory injury in ICIC mice, reducing disease activity. This beneficial effect may be related to its regulation of gut microbiota profiling, an increased diversity of microbiota, a restoration of Bacteroidetes, and an inhibition of the growth advantage of pathogenic bacteria such as Helicobacter and Escherichia-Shigella.

Objective To evaluate the efficacy and safety of different antimicrobial regimens in patients with bloodstream infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP).Methods The clinical date of patients with CRKP bloodstream infections were retrospectively analyzed at the First Affiliated Hospital of Zhejiang University Medical College between January 2017 and January 2018.All subjects were separated into three groups based on antibiotics regimens over 72 hours,including meropenem 2.0 g every 8 hours,tigecycline 200 mg as initial dose and 100 mg every 12 hours,and polymyxin B 1.25 mg/kg every 12 hours as salvage treatment of tigecycline.Results A total of 86 patients were finally recruited,including 14,52 and 20 patients in groups of meropenem,tigecycline and polymyxin B salvage,respectively.All of the strains were resistant to meropenem and susceptible to tigecycline and polymyxin B initially,while 2 of them became resistant to tigecycline during treatment.The 28-day mortality was significantly higher in meropenem group (13/14) than that in tigecycline group and polymyxin B salvage group (61.5％,32/52) and (12/20),respectively (P＜0.01),while as no significant difference was seen in the last two groups (x2=0.014,P＞0.05).The incidences of hepatic impairment [3.8％(2/52) vs.1/20] and renal dysfunction (0 vs.1/20) between tigecycline group and polymyxin B salvage group were both comparable (P＞0.05).Conclusion The meropenem-based therapy is not recommended for CRKP-related bloodstream infections.Tigecycline-based therapy is still disappointing despite salvage use of polymyxin B after 72 hours.Hepatic and nephretic toxicities caused by additional polymyxin B are acceptable.

ObjectiveTo investigate the clinical and pathological features of Hirschprung disease (HD), intestinal neuro-nal dysplasia (IND) and hypoganglionosis (IH) in children.MethodsThe clinical data and pathologic slices from 238 children with intestinal dysganglionosis were retrospectively analyzed. The age, sex, involved intestinal length of children and prognosis were compared.ResultsIn 238 patients, 138 (58.0%) were diagnosed by rectal mucosal biopsies. There were 122 HD patients whose median age at diagnosis was 9 months and the ratio of male to female was 4.3:1, without involvement of whole colon. There were 45 IND patients whose median age at diagnosis was 14 months and the ratio of male to female was 1.05:1, and the whole colon of 33.3% patients was involved. There were two male IH patients whose ages at diagnosis were 12 years and 18 years respectively, and their whole colon was involved. There were 59 patients with HD complicated by IND whose median age at diagnosis was 13 months and the ratio of male to female was 5.56:1 and the whole colon of 16.9% patients was involved. There were 10 male patients with HD complicated by IH whose median age at diagnosis was 11.5 months and the whole colon of 80.0% patients was involved. The ages at diagnosis, the sex ratio, the rates of whole colon involved, and the cure rates among 5 groups were signiifcantly different (allP<0.01).ConclusionsThe rectal mucosal biopsy was the main method in diagnosis of intestinal dysganglionsis in children. Patients with HD had higher incidence and mild condition and favorable prognosis. Patients with IH or patients with HD complicated by IH had lower incidence rates and severe condition and poor prognosis, followed by patients with IND or patients with HD complicated by IND.