Bloodstream Infection Caused by Bacteroides caccae in a Diabetic Patient: a Case Report and Review of the Literature.

BACKGROUND: Bacteroides caccae is a ubiquitous, anaerobic bacteria, but it is not a common cause of pathologic bloodstream infection. Diabetic patients are at increased risk of developing anaerobic bacteria infection. Here, we report a repeated fever case caused by Bacteroides caccae in a diabetic patient. The aim of this study was to describe the clinical characteristics and manifestations of Bacteroides caccae. METHODS: The pathogenic bacteria isolated from patient blood was identified as Bacteroides caccae. Identification of the Bacteroides caccae was done by 16s rDNA sequencing and matrix-assisted laser desorption/ionization-time of light spectrometry. The infection was cured by one-week combined therapy of intravenous Piperacillin tazobactam and oral Ornidazole tablet. RESULTS: After treatment had been completed, no episodes of fever occurred during the follow-up to date. CONCLUSIONS: Bacteroides caccae is regarded as an intestinal, opportunistic pathogenic bacteria. It can invade the mucosa of the intestine and cause various abdominal suppurative infections. Sequencing and matrix-assisted laser desorption/ionization-time of flight spectrometry could have a role for Bacteroides caccae diagnosis. The curative effect of using first generation cephalosporines therapy was unsatisfactory. Using intravenous Piperacillin tazobactam and ornidazole tablet might obtain certain curative effect. Early diagnosis and appropriate anti-infection therapy were necessary to improve the outcome of patients with Bacteroides caccae bloodstream infection.

Carbon monoxide promotes root hair development in tomato.

This study identified the role of CO in regulating the tomato root hair development. Exogenous CO promoted the root hair density and elongation in a concentration-dependent manner. Analysis of cross sections of primary roots also indicated that CO induced the formation of root hairs. Genetic analysis reveals that tomato mutant yg-2 (defective in haem oxygenase-1 activity and intracellular CO generation) displayed a phenotype of delayed root hair development, which however could be reversed by exogenous CO. Further, we analysed LeExt1::beta-glucuronidase reporter gene for root hair formation and found increasing expression of LeExt1 in the CO-exposed root hairs. Finally, CO was able to act synergistically with auxin, ethylene and NO. It is shown that the effect of CO could be blocked by NPA (auxin transport inhibitor), AVG (ethylene biosynthesis inhibitor), Ag(+) (ethylene action inhibitor) or cPTIO (NO scavenger). Exposure of tomato roots to CO also enhanced intracellular NO and reactive oxygen species generation in root hairs. Our results suggest that CO would be required for root hair development and may play a critical role in controlling architectural development of plant roots by a putative mechanism of cross-talk with auxin, ethylene and nitric oxide.