BackgroundThe upper half of the human small intestine, known as the jejunum, is the primary site for absorption of nutrient-derived carbohydrates, amino acids, small peptides, and vitamins. In contrast to the colon, which contains 1011–1012 colony forming units of bacteria per ml (CFU/ml), the normal jejunum generally ranges from 103 to 105 CFU per ml. Because invasive procedures are required to access the jejunum, much less is known about its bacterial microbiota. Bacteria inhabiting the jejunal lumen have been investigated by classical culture techniques, but not by culture-independent metagenomics.ResultsThe lumen of the upper jejunum was sampled during enteroscopy of 20 research subjects. Culture on aerobic and anaerobic media gave live bacterial counts ranging from 5.8 × 103 CFU/ml to 8.0 × 106 CFU/ml. DNA from the same samples was analyzed by 16S rRNA gene-specific quantitative PCR, yielding values from 1.5 × 105 to 3.1 × 107 bacterial genomes per ml. When calculated for each sample, estimated bacterial viability ranged from effectively 100% to a low of 0.3%. 16S rRNA metagenomic analysis of uncultured bacteria by Illumina MiSeq sequencing gave detailed microbial composition by phylum, genus and species. The genera Streptococcus, Prevotella, Veillonella and Fusobacterium, were especially abundant, as well as non-oral genera including Escherichia, Klebsiella, and Citrobacter. The jejunum was devoid of the genera Alistipes, Ruminococcus, Faecalibacterium, and other extreme anaerobes abundant in the colon. In patients with higher bacterial loads, there was no significant change in microbial species composition.ConclusionsThe jejunal lumen contains a distinctive bacterial population consisting primarily of facultative anaerobes and oxygen-tolerant obligate anaerobes similar to those found in the oral cavity. However, the frequent abundance of Enterobacteriaceae represents a major difference from oral microbiota. Although a few genera are shared with the colon, we found no evidence for retrograde movement of the most abundant colonic microbes to the jejunum. Some individuals had much higher bacterial loads, but this was not correlated with decreases in bacterial species diversity or other evidence of dysbiosis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-017-1059-6) contains supplementary material, which is available to authorized users.

Background Respiratory failure in severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection appears related to cytokine release syndrome (CRS) that often results in mechanical ventilation (MV). We investigated the role of tocilizumab (TCZ) on interleukin‐6 (IL‐6) trends and MV in SARS‐CoV‐2 patients. Methods In this longitudinal observational study, 112 patients were evaluated from 2/1/2020 ‐ 5/31/2020. TCZ was administered followed by methylprednisolone to patients with > 3L oxygen (O2) requirement and pneumonia severity index (PSI) score ≤ 130 with CT scan changes. IL‐6, C‐reactive protein (CRP), ferritin, lactate dehydrogenase (LDH), D‐dimer, and procalcitonin were monitored on days 0, 3, and 6 of therapy. Statistical analyses were performed with significance ≤ 0.05. Results 80/112 SARS‐CoV‐2‐positive patients (45 males, 56.96%; 34 females, 43.04%) were included in this study. Seven patients expired (8.75%) and nine patients required MV (11.25%). Median IL‐6 levels pre‐administration of TCZ was 342.50 (78.25 ‐ 666.25) pg/mL compared to post‐administration on day 3 (563; 162 ‐ 783) pg/mL ( P < 0.00001). On day 6, the median dropped to 545 (333.50 ‐ 678.50) pg/mL compared to day 3 ( P = 0.709). CRP, ferritin, LDH, and D‐dimer levels were reduced following TCZ therapy. Conclusions Early use of TCZ may reduce the need for MV and decrease CRP, ferritin, LDH, and D‐dimer levels. The sequential use of methylprednisolone for 72 hours seems to potentiate the effect and prolong the suppression of the cytokine storm. IL‐6 levels may be helpful as a prognostic tool. This article is protected by copyright. All rights reserved.

There has been greater interest in developing additional antimicrobial agents due to the increasing health care costs and resistance resulting from bacterial pathogens to currently available treatment options. Gram-negative organisms including Enterobacteriaceae and Pseudomonas aeruginosa are some of the most concerning threats due to their resistance mechanisms: extended-spectrum beta-lactamase production and Klebsiella pneumoniae carbapenemase enzymes. Ceftazidime is a third-generation broad-spectrum cephalosporin with activity against P. aeruginosa and avibactam is a novel nonbeta-lactam beta-lactamase inhibitor. Avycaz®, the trade name for this new combination antibiotic, restores the activity of ceftazidime against some of the previously resistant pathogens. Avycaz was approved in 2015 for the treatment of complicated urinary tract infections, including pyelonephritis, and complicated intra-abdominal infections with the addition of metronidazole in patients with little to no other treatment options. This review article assesses the clinical trials and data that led to the approval of this antibiotic, in addition to its spectrum of activity and limitations.