Comamonas Testosteroni Emerging Gastrointestinal Pathogen

Comamonas testosteroni newly emerging microorganism previously known as Pseudomonas testosteroni is common environmental bacterium that is not known to be a part of the human commensal organism. Since its identification as a human pathogen in 1987, numerous reports have drizzled in, implicating this organism for various infections. Comamonas testosteroni are rare isolates in microbiology laboratories and have been infrequently reported as an infectious agent in routine clinical practice. Comamonas testosteroni has been rarely observed as an infectious agent in clinical practice. Comamonas testosteroni is rarely recognized as a human pathogen. Most of the reported cases are bloodstream infections. We report this pathogen from the stool of an immunocompromised 48-year-old male. The aim of this case report is to alert clinicians and laboratory physicians for the potential diagnosis and clinical approach of gastrointestinal infections caused by this organism.

Primera identificación en Ecuador de Comamonas kerstersii como agente infeccioso / First identification in Ecuador of Comamonas kerstersii as an infectious agent

Resumen Comunicamos la primera identificación en Ecuador del microorganismo Comamonas kerstersii, cepa aislada a partir de una muestra de líquido de la cavidad abdominal e identificada mediante la técnica de espectrometría de masas MALDITOF. Fue obtenida durante el acto quirúrgico de un paciente con el diagnóstico de una peritonitis aguda, secundaria a una apendicitis perforada. Este microorganismo es considerado un patógeno poco común. Pese a que el género al que pertenece tiene una amplia distribución geográfica, es considerado un agente oportunista.

Abstract We report the first identification in Ecuador of the microorganism Comamonas kerstersii, a strain isolates from a sample of fluid from the abdominal cavity and identified by the technique of mass spectrometry MALDITOF. It was obtained during the surgical act of a patient with the diagnosis of acute peritonitis, secondary to a perforated appendicitis. This microorganism is considered a rare pathogen. Even though the genus to which it belongs has a wide geographical distribution, this pathogen is considered an opportunistic agent.

Bacteriemia por Comamonas kerstersii en un joven con apendicitis aguda / Comamonas kerstersii bacteremia in a young man with acute appendicitis

Resumen Comamonas kerstersii es un bacilo gramnegativo no fermentador, asociado a infecciones intraabdominales. Comunicamos un caso clínico de una bacteriemia por C. kerstersii en un joven con una apendicitis aguda. La primera identificación, mediante el sistema Vitek2 compact (BioMerieux) desde los hemocultivos, fue Comamonas testosteroni. Sin embargo, mediante MALDI-TOF se identificó como C. kerstersii. El paciente fue tratado con ampicilina/sulbactam y luego piperacilina/tazobactam con una evolución favorable. Dentro del género Comamonas, C. testosteroni ha sido la especie más frecuentemente reportada como causa de infecciones en humanos, describiéndose solo 23 casos de C. kerstersii. Dado los problemas en la identificación fenotípica de estos microorganismos, es posible que algunos de los reportes de C. testosteroni pudieran haber correspondido a C. kerstersii. Este caso pone en evidencia el rol patógeno de C. kerstersii y la importancia de utilizar MALDI-TOF como herramienta diagnóstica en bacilos gramnegativos no fermentadores.

Abstract Comamonas kerstersii is a non-fermenting Gram-negative bacillus. It has been associated with intra-abdominal infections. We describe a clinical case of bacteremia caused by C. kerstersii in a young man with acute appendicitis. The first identification, using the Vitek2 compact system (BioMerieux) from blood cultures, was Comamonas testosteroni. However, using MALDI-TOF was identified as C. kerstersii. The patient was treated first with ampicillin sulbactam and then piperacillin tazobactam with favorable evolution. Within the genus Comamonas, C. testosteroni has been the most frequently reported species as a cause of infections in humans, only 23 cases of C. kerstersii being described. Given the problems of phenotypic identification of these microorganisms, it is possible that some C. testosteroni reports could have corresponded to C. kerstersii. This case highlights the pathogenic role of C. kerstersii and the importance of using MALDI-TOF as a diagnostic tool for non-fermenting Gram-negative bacilli identification.

Effects of Comamonas testosteroni on PAHs degradation and bacterial community structure in Leymus chinensis rhizosphere soil / 生物工程学报

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.

Septic Shock due to Unusual Pathogens, Comamonas testosteroni and Acinetobacter guillouiae in an Immune Competent Patient / 대한중환자의학회지

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.

Septic Shock due to Unusual Pathogens, Comamonas testosteroni and Acinetobacter guillouiae in an Immune Competent Patient / 대한구급학회지

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.

Isolation of a novel uric-acid-degrading microbe Comamonas sp. BT UA and rapid biosensing of uric acid from extracted uricase enzyme.

Uric-acid-utilizing soil bacteria were isolated, and 16s rRNA sequence was studied for strain identification. The most prominent uricase-producing bacterium was identified as Comamonas sp BT UA. Crude enzyme was extracted, freeze-dried and its Km and Vmax were determined as 40 μM and 0.047 μM min−1ml−1 using Line-weaver Burke plot. An activity of 80 U/mg of total protein was observed when cultured at 37°C for 84 h at pH 7. The purified enzyme was used to measure uric acid by spectrophotometric method and electrochemical biosensor. In the biosensing system the enzyme was immobilized on the platinum electrode with a biodegradable glutaraldehyde-crosslinked gelatin film having a swelling percentage of 109±3.08, and response was observed by amperometry applying fixed potential. The electrochemical process as obtained by the anodic peak current and scan rate relationship was further configured by electrochemical impedance spectroscopy (EIS). The polymer matrix on the working electrode gave capacitive response for the electrode–electrolyte interaction. The sensitivity of the biosensor was measured as 6.93 μAμM−1 with a sensor affinity [Km(app)] of 50 μM and 95% reproducibility after 50 measurements. The spectrophotometric method could be used in the range of 6–1000 μM, whereas the biosensor generated linear response in the 1.5– 1000 μM range with a response time of 24 s and limit of detection of 0.56 μM. Uric acid was estimated in human blood samples by the biosensor and satisfactory results were obtained.

Fatal Delftia acidovorans infection in an immunocompetent patient with empyema

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.

Evaluation of Factors Affecting Polyhydroxyalkanoates Production by Comamonas sp. EB172 Using Central Composite Design

Aims: Statistical approach, central composite design (CCD) was used to investigate the complex interaction among temperature (25-37 °C), initial medium pH (5-9), inoculum size (4-10 % (v/v)), concentration of (NH4)2SO4 (0-1 g/L) and concentration of mixed organic acids (5-10 g/L) in the production of polyhydroxyalkanoates by Comamonas sp. EB172. Methodology and Results: Mixed organic acids derived from anaerobically treated palm oil mill effluent (POME) containing acetic:propionic:butyric (ratio of 3:1:1) were used as carbon source in the batch culture of Comamonas sp. EB172 to produce polyhydoxyalkanoates (PHAs). The analysis of variance (ANOVA) showed that all five factors were significantly important in the batch fermentation by shake flask with a P value of less than 0.001. The optimal temperature, initial medium pH, inoculum size, concentration of (NH4)2SO4 and concentration of mixed organic acids were 30 °C, 7.04, 4.0 % (v/v), 0.01 g/L and 5.05 g/L respectively. Conclusion, significance and impact of study: Optimization of the production medium containing mixed organic acids has improved the PHA production for more than 2 folds. Under optimal condition in the shake flask fermentation, the predicted growth is 2.98 g/L of dry cell weight (DCW) with 47.07 wt % of PHA content. The highest yield of PHA was 0.28 g of PHA per g mixed organic acids.

Fatal Delftia acidovorans infection in an immunocompetent patient with empyema

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.

A Case of Peritonitis due to Comamonas testosteroni in a Patient on Continuous Ambulatory Peritoneal Dialysis / 대한신장학회지

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.

Experience of Comamonas Acidovorans Keratitis with Delayed Onset and Treatment Response in Immunocompromised Cornea

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.

Experience of Comamonas Acidovorans Keratitis with Delayed Onset and Treatment Response in Immunocompromised Cornea

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.

A Case of Comamonas Acidovorans Corneal Ulcer

PURPOSE: To report a case of a Comamonas acidovarans corneal ulcer treated with antibiotics in Korea. Comamonas acidovarans corneal ulcer has not been previously reported to our knowledge. METHODS: A 70-year-old woman visited our clinic complaining of left ocular pain and decreased visual acuity for six days. We performed a smear and culture on the corneal lesion and treated it with topical and systemic antibiotics. RESULTS: Comamonas acidovorans was cultured from ulcer lesion. Corneal ulcer improved with the administration of ciprofloxacin and tobramycin.

Comamonas Acidovorans Peritonitis in a CAPD Patient Managed with Preservation of the Catheter / 대한신장학회잡지

To date, only one case of peritonitis with exit site infection in peritoneal dialysis caused by this micro- organism has been reported. In spite of its apparently benign clinical course, which distinguished it from peritonitis caused by Pseudomonas, this peritonitis relapsed and Comamonas could not be eliminated from the peritoneal liquid, probably due to the persistence of the micro-organism in the exit site. Consequently, peritoneal catheter was removed. In this case, a 68-year-old man was admitted with fever, abdominal tenderness and cloudy peritoneal effluent and empirically treated with antibiotics(cefazolin, tobramycin), intraperitoneally(IP) for 7 days. The first culture was positive for Comamonas acidovorans, sensitive to ceftazidime, cefotetan, ceftriaxone, ciprofloxaxin and imipenem and the perotoneal effluent remained cloudy after 7 days. He was treated with ceftazidime IP, oral ciprofloxacin and nystatin for 26 days. 4 days after the antibiotics treatment, the patient was asymptomatic and the cell count of peritoneal effluent was 50 WBC/mm3 with negative culture. 25 days after the treatment, the patient remained asymptomatic and with 5 WBC/mm3 in peritoneal effluent. Consequently, We experienced a case of peritonitis due to Comamonas acidovorans in a patient on CAPD without exit site infection and managed with preservation of the catheter.