Effects of holding time on the diversity and composition of potential pathogenic bacteria in ship ballast water.

Ballast water is a common vector for the transport of invasive species to new marine and aquatic environments. We used a metagenomics approach to examine the diversity and composition of potential pathogens communities in ballast water from ships in the route of China- Southeast Asia (CSEA). 16 kinds of potential pathogenic genus were detected in the ballast water. Interestingly, the ballast holding time had an important effect on the distribution of potential pathogens in ballast water. The abundance of Pseudoalteromonas in the longer ballast water holding time was less than the shorter ballast water holding time. Bacteroides had completely disappeared in the long ballast holding time samples. Moreover, The Shannon index of samples with longer ballast water holding time (1.80 ± 0.07) was higher than those with shorter ballast water holding time (0.83 ± 0.13). The potential pathogenic genus (Arcobacter, Aeromonas, Enterobacter and so on) lived in the long ballast holding time vessels had more diversity. Besides, the total suspended solids (TSS), total organic carbon (TOC) and particulate organic carbon (POC) had a strong positive correlation with most potential pathogens in the ballast water, while the dissolved oxygen (DO) had a clear negative correlation with the potential pathogens in the longer ballast holding time samples. In conclusion, these results provide detailed descriptions of the characteristics of the potential pathogens present in ballast water, document significant potential pathogens diversity, and indicate the importance of ballast holding time for potential pathogens lived in ballast water.

Clinical investigation of gut microbiota dysbiosis in septic patients / 中华急诊医学杂志

Objective To investigate the characteristics of gut microbiota dysbosis in septic and non-septic patients in ICU.Methods A prospective observational research was conducted.Ten septic patients(septic group),ten patients without sepsis(non-septic group) were admitted to Department of Critical Care Medicine of General Hospital of Ningxia Medical University from February 2017 to June 2017 were enrolled.And ten healthy persons was enrolled as control group.Stool samples were collected from septic and non-septic patients within two days following admission to the intensive care unit (ICU);healthy persons' was random.High throughput 16S rRNA gene sequencing technology was used to detect fecal bacterium of three groups.Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) score,Sequential Organ Failure Assessment (SOFA) score of patients were recorded on the first day after admission to ICU.Results Compared with the control group,the α diversity of gut microbiota in non-septic and septic groups showed a downward trend,the [3 diversity showed that the structure of gut microbiota in non-septic and the septic groups was significant different,and the individual differences were more obvious.At the level of phylum,compared with the control group,the proportion of Firmicutes+Bacteroidetes in non-septic and septic groups decreased significantly(P=0.013,0.028),and the proportion of Proteobacteria increased(P=0.017,0.026),while the proportion of Fusobacteria just increased in the non-septic group(P ＜ 0.01).At the level of genus,compared with the control group,the proportion of beneficial symbiotic genus in non-septic and septic groups can be seen decreased,such as Ruminococcus(P=0.045,0.026),Pseudobutyrivibrio(P=0.009,＜ 0.01),Anaerostipes(P=0.011,0.003),Coprococcus(P=0.045,0.011),Phascolarctobacterium(P=0.008,0.022),Subdoligranulum(P=0.006,0.026).The proportion of Lactobacillus,Dorea,Faecalibacterium,Roseburia and Blautia showed downward trend in non-septic and septic groups,but only the decline of Lactobacillus in non-septic group had statistical difference(P=0.005),and the decline of Dorea,Faecalibacterium,Roseburia and Blautia in septic group had statistical differences(P=0.037,0.038,0.002 and 0.017,respectively).The proportion of conditional pathogenic Fusobacterium,Actinomyces,Peptstreptococcus,Streptococcus increased in non-septic group(P=0.001,0.019,0.011 and 0.014,respectively),the proportion of pathogenic Staphylococcus(P=0.035,0.006),Enterococcus(P=0.001,0.001),Anaerococcus(P=0.006,0.006) and Bacillus(both P ＜ 0.01) increased in non-septic and septic groups.Conclusions Gut microbiota dysbiosis occured in septic and non-septic patients in the ICU,and showed that diversity decreased,structure of intestinal flora changed,obligate anaerobic bacteria decreased,facultative anaerobic bacteria increased,benefical symbiotic bacteria decreased,pathogenic bacteria increased and can be the dominate genus.