[Respiratory isolation in suspected tuberculosis with negative direct sputum examination]

A metagenomic study of the gut microbiome in PTB'S disease

BACKGROUND

There is an abundant link between the gut microbiota and human health and it plays a critical role in the clinic. It is recognized that microbial dysregulation contributes to the pathogenesis of tuberculosis (TB), but the underlying mechanisms remain unclear. In this study, we investigated the association of gut microbiome composition with TB as well as its possible roles in the development of this disease.

METHODS

Fecal samples were collected from 10 TB patients and 20 healthy control samples. DNA extracted from fecal samples was subjected to 16S rDNA gene sequencing analysis on the Illumina MiSeq platform.

RESULTS

Compared with healthy control samples, the gut microbiome of patients with TB was characterized by the decreased Alpha diversity. Perhaps, the decrease of microbial diversity which results in microbial dysregulation is the reason for clinical patients with more symptoms. The PTB group showed the most unique microbiota by higher abundance of Bifidobacteriaceae, Bifidobacteriales, Coriobacteriaceae, Coriobacteriales, Actinobacteria, Caulobacteraceae, Phyllobacteriaceae, Rhizobiales, Burkholderiaceae, Burkholderiaceae. Inflammatory status in PTB patients may be associated with the increased abundance of Clostridia and decreased abundance of Prevotella. We found that the abundance of Solobacterium and Actinobacteria was higher in the patients. There were 4 significant differences (p<0.05) in the two groups which belonged to four metabolic categories, including endocytosis, phosphotransferase system (PTS), toluene degradation, and amoebiasis.

CONCLUSION

We applied the approach of metagenomic sequencing to characterize the features of gut microbiota in PTB patients. The present study provided a detailed analysis of the characterization of the gut microbiota in patients based on the clinic. According to the metagenome analysis, our results indicated that the gut microbiota in PTB patients was significantly different from healthy control samples as characterized by the bacteria and metabolic pathway. The richness of the gut microbiota in patients was revealed. It was hypothesized that the above-mentioned changes of the gut microbiota could exert an impact on the development of PTB through the downstream regulation of the immune status of the host by way of the gut-lung axis.

Efficacy of 75% alcohol in pretreatment of the Andersen sampler in trapping maximum airborne microbes

The present study was conducted to evaluate the effects of the pretreatment methods and sampling time on the sampling of airborne bacteria in hospitals. Methods for the pretreatment of Andersen samplers, namely, non-sterilized, 75% ethanol and autoclaving sampled for 5 min, 10 min and 15 min in the general ward and class 1000 clean operating department, respectively, were studied. Statistical analysis was used to compare the differences in sampling results of airborne bacteria under different pretreatment methods, sampling time and environmental conditions. In the first test, the sampling results of the airborne bacteria obtained by pretreatment of the sampler with 75% ethanol and without pre-treatment were not very different, and the sampling results showed a certain declining trend with the extension of the sampling time. In the second test, the pretreatment effect of autoclaving was significantly better than that of 75% ethanol, and the sampling time had no effect on the sampling results. After removing the influencing factors of the environment, the results were consistent with the results of the second test. It was observed that the Andersen samplers should not be pretreated with 75% ethanol before airborne microbes sampling. The pretreatment should be carried out by autoclaving, and the sampling time has little effect on the sampling results.