Cytochrome P450 monooxygenases as powerful biocatalysts catalyze a wide range of chemical reactions to facilitate exogenous substances metabolism and biosynthesis of natural products. In order to explore new catalytic reactions and increase the number of P450 biocatalysts used in synthetic biology, a new self-sufficient cytochrome P450 monooxygenase (P450(VpMO)), belongs to CYP116B class, was mined from Variovorax paradoxus S110 genome and expressed in Escherichia coli. Based on characterization of the enzymatic properties, it shows that the optimal pH and temperature for P450(VpMO) reaction activity are 8.0 and 45 °C, respectively. P450(VpMO) is relatively stable at temperatures below 35 °C. The Km and kcat of P450(VpMO) toward 4-Methoxyacetophenone are 0.458 mmol/L and 2.438 min⁻¹, respectively. Importantly, P450(VpMO) was able to catalyze the demethylation reaction for a range of substrates containing methoxy group. Its demethylation reactivity is reasonably better than other P450s belongs to CYP116B class, particularly, for 4-methoxyacetophenone with a great conversion efficiency at 91%, showing that P450(VpMO) could be used as a great biocatalyst candidate for further analysis.
Catalysis ; Comamonadaceae ; enzymology ; genetics ; Cytochrome P-450 Enzyme System ; genetics ; metabolism ; Gene Expression ; Synthetic Biology

To investigate the degradation of polycyclic aromatic hydrocarbons (PAHs) and the changes of rhizosphere microorganisms in the rhizosphere soil of Leymus chinensis during the remediation of PAHs contaminated soil by Comamonas testosteroni (C.t)-assisted Leymus chinensis, we evaluated the removal of PAHs in the rhizosphere of Leymus chinensis using gas chromatography-mass spectrometry (GC-MS), analyzed the bacterial community and the diversity in Leymus chinensis rhizosphere soil by high-throughput sequencing technology, characterized the correlation among PAHs degradation and bacterial community components performing redundancy analysis (RDA) and network analysis, and predicted PAHs degradation potential via PICRUSt software in this paper. The degradation of PAHs in the rhizosphere of Leymus chinensis was promoted, the abundance and diversity of bacteria and the correlation among bacteria and PAHs were changed, and the degradation potential of PAHs in Leymus chinensis rhizosphere soil was enhanced in the later stage of phytoremediation (60-120 d) due to the incorporation of C.t. The accelerated degradation of three PAHs (Nap, Phe, BaP) was accompanied by the differ abundance and correlation of Proteobacteria (Sphingomonas, MND1, Nordella), Actinomycetes (Rubrobacter, Gaiella), Acidobacteria (RB41) and Bacteroides (Flavobacterium) affected by C.t. The results provide new insight into the microorganism choices for microbial assisted plant remediation of soil PAHs and the mechanisms of enhanced PAHs degradation via the combination of Comamonas testosteroni engineering bacteria and plants.
Biodegradation, Environmental ; Comamonas testosteroni/genetics* ; Polycyclic Aromatic Hydrocarbons/analysis* ; Rhizosphere ; Soil ; Soil Microbiology ; Soil Pollutants

OBJECTIVE: To determine the drug resistance of Comamonas testosteroni (C. testosteroni) by the Kirby-Bauer (K-B) method without Clinical and Laboratory Standards Institute (CLSI) explanation or the minimum inhibitory concentration (MIC) method with the standard CLSI explanation to evaluate the sensitivity of K-B method in detection of C. testosteroni.
 METHODS: K-B method and MIC method was used to determine the sensitivity of C. testosteroni to Piperacillin, Cefepime, Piperacillin/tazobactam, Imipenem, Meropenem, Amikacin, Gentamicin, Tobramycin, Ceftazidime and Ciprofloxacin. The interpretation standard for Pseudomonas aeruginosa was temporary used for the K-B method. The coincident rate was compared between the two methods.
 RESULTS: The complete or partial coincident rate for K-B method and MIC method to detect Piperacillin and Cefepime was 97.4% or 2.6%; the complete coincidence rate to detect Piperacillin/tazobactam, Imipenem and Meropenem was 100%; the complete or partial coincident rate to detect Amikacin, Gentamicin and Tobramycin 94.7% or 5.3%; the complete or partial coincident rate to detect Ceftazidime was 97.4% or 2.6%; the complete or partial coincident rate to detect Ciprofloxacin 86.8% or 10.6%, and the full non-coincidence rate was 2.6%.
 CONCLUSION The results of drug sensitive test from the two methods are highly consistent. We suggest that the microbiology labs do not report the interpretive results for C. testosteroni with K-B method but report the test results.
Anti-Bacterial Agents ; Cefepime ; Cephalosporins ; Comamonas testosteroni ; Imipenem ; Meropenem ; Microbial Sensitivity Tests ; Penicillanic Acid ; analogs & derivatives ; Piperacillin ; Piperacillin, Tazobactam Drug Combination ; Pseudomonas aeruginosa ; Thienamycins

Comamonas testosteroni and Acinetobacter guillouiae are gram-negative bacilli of low virulence that are widely distributed in nature and normal flora. Despite their common occurrence in environments, they rarely cause infectious disease. We experienced a case of septic shock by C. testosterone and A. guillouiae, and isolated them by 16S ribosomal RNA sequencing method from the blood cultures of a previous healthy female during postoperative supportive care. This is the first case of septic shock required ventilator care and continuous renal replacement therapy due to these organisms in Korea.
Acinetobacter* ; Bacteremia ; Comamonas testosteroni* ; Comamonas* ; Communicable Diseases ; Female ; Humans ; Korea ; Renal Replacement Therapy ; RNA, Ribosomal, 16S ; Shock, Septic* ; Testosterone ; Ventilators, Mechanical ; Virulence

Comamonas testosteroni and Acinetobacter guillouiae are gram-negative bacilli of low virulence that are widely distributed in nature and normal flora. Despite their common occurrence in environments, they rarely cause infectious disease. We experienced a case of septic shock by C. testosterone and A. guillouiae, and isolated them by 16S ribosomal RNA sequencing method from the blood cultures of a previous healthy female during postoperative supportive care. This is the first case of septic shock required ventilator care and continuous renal replacement therapy due to these organisms in Korea.
Acinetobacter ; Bacteremia ; Comamonas testosteroni ; Comamonas ; Communicable Diseases ; Female ; Humans ; Korea ; Renal Replacement Therapy ; RNA, Ribosomal, 16S ; Shock, Septic ; Testosterone ; Ventilators, Mechanical ; Virulence

Delftia acidovorans (earlier known as Comamonas acidovorans) is an aerobic, non-fermentative, Gram negative rod, classified in the Pseudomonas rRNA homology Group III. Reports of isolation of the organism from serious infections like central venous catheter associated bacteremia, corneal ulcers, otitis media exist. The microbiologists can identify this organism based on an orange indole reaction. This reaction demonstrates the organism's ability to produce anthranilic acid from tryptophan on addition of Kovac's reagent; which gives the media its characteristic "pumpkin orange" colour. Here we report the isolation of this organism from the Endotracheal tube aspirate of a 4 year old child. With the increasing use of invasive devices, it has become important to recognize these non fermentative gram negative bacilli as emerging source of infection even in immunocompetent individuals.
Anti-Bacterial Agents ; pharmacology ; therapeutic use ; Child, Preschool ; Delftia acidovorans ; Drug Resistance, Bacterial ; Empyema ; Fatal Outcome ; Gram-Negative Bacterial Infections ; Humans ; Shock, Septic

Delftia acidovarans is aerobic, nonfermentative Gram-negative rod commonly found in soil and water. Generally it is nonpathogenic but it unusually can cause bacteremia in immunocompromised patients. We present a case of peritonitis due to D. acidovorans in a patient on continuous ambulatory peritoneal dialysis. A 75-year-old woman was admitted with abdominal pain and cloudy peritoneal effluent. She was empirically treated with intraperitoneal (IP) cefazolin and ceftazidime, and then IP ceftazidime and oral ciprofloxacin, but peritonitis did not improve. Seven days after admission, D. acidovorans was identified from the peritoneal effluent, which was sensitive to amikacin, ceftazidime, ciprofloxacin and imipenem. Catheter removal was considered with regard to poor response to adequate antibiotics; however, 4 days after changing to IP imipenem/cilastatin, abdominal pain, the leukocyte count of peritoneal effluent and C-reactive protein decreased. She was treated with imipenem/cilastatin for two weeks and discharged with the dialysis catheter intact.
Abdominal Pain ; Aged ; Amikacin ; Bacteremia ; C-Reactive Protein ; Catheters ; Cefazolin ; Ceftazidime ; Ciprofloxacin ; Delftia ; Delftia acidovorans ; Dialysis ; Female ; Humans ; Imipenem ; Immunocompromised Host ; Leukocyte Count ; Peritoneal Dialysis ; Peritoneal Dialysis, Continuous Ambulatory ; Peritonitis ; Soil

Comamonas testosteroni has rarely been implicated as a human pathogen. We here present a case of peritonitis due to this organism in a patient on continuous ambulatory peritoneal dialysis (CAPD). A 32-year-old woman was admitted with abdominal pain and cloudy peritoneal effluent. Empirical intraperitoneal (IP) treatment with cefazolin and ceftazidime was started. The culture was positive for C. testosteroni and antibiotic was changed to ceftazidime IP. Four days after the ceftazidime treatment, the patient became asymptomatic. The follow-up culture from peritoneal effluent at 7th day was negative. This treatment was maintained for 21 days. After that, culture negative peritonitis occurred twice for 2 months in this patient, so CAPD catheter had to be removed. This is the first reported case of CAPD peritonitis caused by C. testosteroni. It is important for clinicians to recognize that CAPD peritonitis is caused by this organism which has been largely overlooked as a potential pathogen.
Abdominal Pain ; Adult ; Catheters ; Cefazolin ; Ceftazidime ; Comamonas ; Comamonas testosteroni ; Female ; Follow-Up Studies ; Humans ; Peritoneal Dialysis ; Peritoneal Dialysis, Continuous Ambulatory ; Peritonitis

Delftia acidovorans is a gram-negative motile rod found ubiquitously in soil and in water. Confirmed isolation from clinical infections is rare, and has been documented mostly in immunocompromised patients or those with indwelling catheters. A 53-year-old man was referred for the evaluation of a huge mass-like lesion found incidentally by chest X-ray. The lesion occupied more than half of the right lung and was diagnosed as a large loculated pleural effusion by CT scan. Bloody pus was drained through a percutaneous catheter, and D. acidovorans, identified by the Vitek GN card and confirmed by amplification of 16S ribosomal RNA and sequencing analysis, was isolated repeatedly from the drained pus. The patient was treated with imipenem/cilastatin to which the organism was sensitive. This is a rare report of chronic empyema associated with D. acidovorans in the respiratory system of an immunocompetent patient.
Catheters ; Catheters, Indwelling ; Delftia ; Delftia acidovorans ; Drainage ; Empyema ; Empyema, Pleural ; Humans ; Immunocompetence ; Immunocompromised Host ; Lung ; Middle Aged ; Pleural Effusion ; Respiratory System ; RNA, Ribosomal, 16S ; Soil ; Suppuration ; Thorax

PURPOSE: To report 2 cases of Comamonas acidovorans keratitis in immunocompromised cornea. METHODS: A complete review of the medical records of the two cases of Comamonas acidovorans keratitis. RESULTS: We found some similarities in clinical courses of two cases. Both of them showed development of keratitis during the management with corticosteroids, delayed onset, slow response to antibiotics, and relatively less affected corneal epithelium. CONCLUSIONS: Comamonas acidovorans is known as a less virulent organism. However it can cause an indolent infection that responds slowly even to adequate antibiotics therapy in immunocompromised corneas.
Amikacin/therapeutic use ; Anti-Bacterial Agents/therapeutic use ; Ceftazidime/therapeutic use ; Ciprofloxacin/therapeutic use ; Corneal Ulcer/diagnosis/drug therapy/*microbiology ; Delftia acidovorans/*isolation & purification ; Drug Therapy, Combination ; Eye Infections, Bacterial/diagnosis/drug therapy/*microbiology ; Gram-Negative Bacterial Infections/diagnosis/drug therapy/*microbiology ; Humans ; *Immunocompromised Host ; Male ; Microbial Sensitivity Tests ; Middle Aged