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A Rare Pathogen Comamonas Testosteroni: A Case Report and Review of The Literature

S. Gayenur Buyukberber1*, Ipek Mumcuoglu1, B.Orkun Ozbay2, Adalet Aypak2, Bedia Dinc1

1Department of Medical Microbiology, Ankara City Hospital, Ankara, Turkey

2Department of Infectious Diseases and Clinical Microbiology, Ankara City Hospital, Ankara, Turkey

*Corresponding Author:
S. Gayenur Buyukberber
Department of Medical Microbiology,
Ankara City Hospital, Ankara,

Received: 07-Feb-2022, Manuscript No. JCMCS-22-53664; Editor assigned: 09- Feb-2022, Pre QC No. JCMCS-22-53664 (PQ); Reviewed: 23-Feb-2022, QC No. JCMCS-22- 53664; Accepted: 28-Feb-2022, Manuscript No. JCMCS-22-53664 (A); Published: 4-Mar-2022, DOI: 10.4172/J Clin Med Case Stud.7.2.005.

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Urinary Tract Infection; Urinalysis; Immunodeficient; Mass spectrophotometer


Comamonas testosteroni is a Gram-negative, aerobic, motile, non-spore-forming bacillus. It has not been recognized as a component of the endogenous human microflora. Due to its ability to survive in liquid environments, it can survive for a long time in a hospital environment and cause opportunistic infections. Although rare, C. testosteroni has been reported as a cause of cellulitis, peritonitis, endocarditis, meningitis, endophthalmitis, tenosynovitis, pneumonia and bacteremia. Here, we present a case of a 4-year-old girl who was operated on for persistent cloaca with C. testosteroni isolated in her urine culture. Identification studies were performed by MALDI-TOF MS (bioMerieux, France) Mass Spectrophotometer method. Antibiotic susceptibility tests were performed with the automatic device VITEK-2 Compact (bioMérieux, France). Microorganism was found susceptible to ceftazidime and ciprofloxacin; intermediate susceptible to meropenem and piperacillin/tazobactam and resistant to gentamicin, amikacin, imipenem and trimethoprim-sulfamethoxazole. With this case report, C. testosteroni was reported as the first cause of urinary tract infection in our country and the third in the world.


Comamonas testosteroni, formerly known as Pseudomonas testosteroni, is a gram-negative, aerobic, motile, non-fermentative and non-spore forming bacillus [1]. The name "Testosteroni" comes from the bacteria's ability to use the carbon in testosterone metabolism, as is observed in some types of Pseudomonas and fungi [2]. C. testosteroni is commonly found in soil, water, plants, animals and waste all over the world and is considered as an environmental microorganism which is not defined as a human endogenous microflora element [1,3]. Because of its ability to live in liquid environments, this organism is seen as an opportunistic nosocomial pathogen in hospitals and intensive care units. It grows well on routine bacteriologic media such as sheep blood agar and chocolate agar [1]. The need for minimal nutrients to grow even in distilled water and adaptation to different physical conditions leads to its important role as an opportunistic pathogen in hospitals. Since it became clinically important; it has been reported in publications as a causative agent of cellulitis, peritonitis, endocarditis, meningitis, endophthalmitis, tenosynovitis, pneumonia and bacteremia [2].

Case Report

A 4-year-old girl with frequent urinary incontinence and recurrent urinary tract infection despite taking prophylaxis has applied to our hospital for further examination. She was operated two years ago due to persistant cloaca, a total urogenital mobilization was performed, and postoperative uterus, vagen and partial bladder necrosis occured. She has a colostomy in the left lower quadrant, and has frequent urinary incontinence and recurrent urinary tract infection despite taking prophylaxis.

Urinalysis report was; leukocyte 14 p/HPF, leukocyte esterase ++, bacteria were trace and others were found within normal limits. Colonies grown on blood and MacConkey agar, incubated at 35–37°C, were identified as 99% probability C. testosteroni by Mass Spectrometry method MALDI-TOF MS (bioMérieux, France). Antibiotic susceptibility tests were performed with the automatic device of VITEK-2 Compact (bioMérieux, France) and interpreted in accordance with EUCAST criteria and it was susceptible to ceftazidime, ciprofloxacin; intermediate susceptible to meropenem, piperacillin / tazobactam; resistant to gentamicin, amikacin, imipenem, and trimethoprim-sulfamethoxazole. Ceftazidime was added to the treatment of the patient who was already treated with amikacin. There was no growth in the control urine culture performed after 5 days of treatment. And then the patient was discharged with cure. The increase in pathogenicity and antibiotic resistance of C. testosteroni once again demonstrates the importance of rational antibiotic use. With this case report, C. testosteroni was reported as the first cause of urinary tract infection in our country and the third in the world.


C. testosteroni which was first reported in 1975 is an infection agent in samples such as cerebrospinal fluid, abdominal abscess and appendix tissue, most commonly from blood and peritoneal fluid (Table 1). Most of the previously reported cases were immunodeficient due to malignancy, diabetes mellitus, chronic liver disease, and end-stage renal disease [2]. The agent is most frequently isolated from the blood (20 cases), followed by peritoneal fluid (9 cases), cerebrospinal fluid (3 cases) and urine (2 cases). There are rare cases in which the agent was isolated from cord fluid, respiratory secretions, deep tracheal aspirate, abdominal abscess, bite site tissue (animal bite), aortic valve, appendicitis, stool and vitreous fluid. Appendicitis is found to be the most common predisposing factor in cases detecting C. testosteroni in peritoneal fluid. Although bacteria is not an endogenous flora element, the isolation of a large number of patients with perforated appendicitis (7 out of 9 cases) made us think that this microorganism could create a unique location in the appendix [1].

No Age/ Gender Specimens isolated   Predisposing factor Antibiotic therapy Outcome References
1 31/F Blood   Rheumatic Heart Disease Kanamycin, Tetracycline Recovered Atkinson et al.(1975) [12]
2 31/M Abdominal Abscess Drainage Fluid   Perforated Appendicitis Cefoxitn, Ampicillin then drainage, Gentamicin, Clindamisn Recovered Barbaro et al.(1987) [13]
3 24/F Cerebrospinal Fluid   Intravenous Drug Abuse Moxalactam, Nafcillin Recovered Barbaro et al.(1987) [13]
4 59/F Peritoneal Fluid   Alcoholic cirrhosis Cefoxitin Recovered Barbaro et al.(1987) [13]
5 11/M Peritoneal Fluid   PerforatedAppendicitis Ampicillin, Clindamycin, Tobramycin Recovered Barbaro et al.(1987) [13]
6 12/F Peritoneal Fluid   PerforatedAppendicitis Cefoxitin Recovered Barbaro et al.(1987) [13]
7 21/F Peritoneal fluid   Perforated Appendicitis, Pregnancy Cefoxitin Recovered Barbaro et al.(1987) [13]
8 Stillborn Cord fluid   Maternal İntravenousDrug Abuse Could not be cured due to death  Dead Barbaro et al.(1987) [13]
9 84/F Urine   Congestive Heart Failure Ampicillin Recovered Barbaro et al.(1987) [13]
10 Newborn Blood   Maternal İntravenousDrug Abuse, Prematurity Ampicillin Dead Barbaro et al.(1987) [13]
11 17/F Peritoneal Fluid   Appendicitis No data Recovered Barbaro et al.(1987) [13]
12 59/M No data   No data No data Recovered Barbaro et al.(1987) [13]
13 66/M Peritoneal fluid   No data No data Recovered Barbaro et al.(1987) [13]
14 14/M Appendix   Appendicitis No data Recovered Barbaro et al.(1987) [13]
15 15/M Peritoneal Fluid   No data No data Recovered Barbaro et al.(1987) [13]
16 4/M Blood   No data No data Recovered Barbaro et al.(1987) [13]
17 28/M Blood   No data No data Recovered Barbaro et al.(1987) [13]
18 24/M Peritoneal Fluid   Perforated Appendicitis Cefoxitin Recovered Barbaro et al.(1987) [13]
19 No data Respiratory Secretions   AIDS-related complex Ceftazidime Recovered Franzetti et al. (1992)
20 35/M Animal Bite Tissue   Zoonotic Infection Ceftazidime, Gentamicin Recovered Isolato et al.(2000)
21 75/F Blood, Central Venous Catheter   Cancer Central Venous Catheter Ceftazidime, Gentamicin Recovered Le Moal et al.(2001)
22 89/M Blood   Advanced age Levofloxacin Recovered Smith et al.(2003)
23 50/M Cerebrospinal Fluid   Cholesteatoma Meropenem Recovered Arda et al.(2003) [5]
24 49/M Blood, mitral valve   Infective Endocarditis Cefepime, Gentamicin then Ampicillin and Surgery Recovered Cooper et al.(2005)
25 22/M Blood, Peritoneal Fluid   Perforated Appendicitis Cefazolin Recovered Gul et al.(2007) [6]
26 54/F Blood   Chemotherapy, Central VenousCatheter Cefepime, Ciprofloxacin Recovered Abraham et al.(2007)[4]
27 54/M Cerebrospinal Fluid   Chronic Alcoholic Car Accident No data Dead Jin et al.(2008)
28 82/F Vitreous Biopsy   Advanced age, Diabetes Ceftazidime, Ciprofloxacin Recovered Reddy et al. (2009)[14]
29 83/M Blood   Advanced age, Ischemic Cerebrovascular Accident Amikacin, Piperacillin / Tazobactam Recovered Katircioglu et al (2010)[7]
30 64/F Blood   Hemodialysis No data Recovered Nseir et al. (2011)
31 54/M Blood   Foot Injury Oxacillin, Flomoxef then Ciprofloxacin Recovered Tsui et al. (2011)[11]
32 73/M Blood   Hepatocellular Cancer, Chronic Hepatitis B Metasin, Gentamicin followed by Levofloxacin Recovered Tsui et al. (2011)[11]
33 10/M Endotracheal Aspirate   Cerebral Palsy, Tracheostomy Ceftriaxone, Clarithromycin Recovered Ozden et al. (2011)[8]
34 10/M Blood   Medullablastoma, Chemotherapy Ciprofloxacin, Amikacin Recovered Farshad et al.(2012)
35 19/F Blood   Osteosarcoma Imipenem, Vancomycin, Ciprofloxacin Recovered Farshad et al.(2012)
36 16/M Peritoneal Fluid   Perforated Appendicitis Amikacin, Ampicillin, Clindamycin Recovered Bayhan et al. (2013)[3]
37 80/F Blood   Diabetes Cefazolin, Doripenem Recovered Orsini et al. (2014)[2]
38 51/M Aortic valve   No Ciprofloxacin Recovered Duran et al. (2015)[1]
39 42/F Blood   Septicshock Ceftazidimeand
Recovered Who al (2015)
40 62/M Blood   Diabetes, Ischemic Serbrovascular Accident Could not be cured due to death Dead Pekinturk N.,Akgunes A. (2016)[4]
41 1/F Blood   Acute Gastroenteritis, Sepsis Ceftriaxone Recovered RuziakiW.,Hashami H.(2017) [15]
42 65/F stool   AcuteGastroenteritis,
Ciprofloxacin Recovered FarooqS. et al.(2017)
43 30/F Blood   Neutropenia Moxifloxacin Recovered Aktar et al.(2018) [10]
44 46/F Blood andurine   Sepsis GentamicinandImipenem Recovered TiwariSet al.(2019)
45 4/F Urine   Persistent Cloaca Ceftazidime, Amikacin Recovered This case

Table 1. Comamonas testosterone-induced infection cases in the literature.

Eight C.testosteroni cases have been reported in Turkey so far. The first case was purulent meningitis in a patient with recurrent cholesteatoma reported. The microorganism was isolated from the cerebrospinal fluid and treated with meropenem [4,5].

The second case was C. testosteroni bacteremia in a patient with perforated acute appendicitis. It was isolated from the patient's peritoneal fluid and blood cultures. It had been treated with cefazolin [6].

The third case was reported in 2010. It was a case of bacteremia in an intensive care patient. This case isolated from blood cultures was the first case that showed the development of multiple antibiotic resistances including imipenem [7].

The fourth case was the pneumonia case in an intensive care patient reported. Microorganism isolated from endotracheal aspirate culture; was found susceptible to amikacin, imipenem, levofloxacin, meropenem, netilmicin, piperacillin-tazobactam, ceftazidime, cefepime, tigecycline, and trimethoprim-sulfamethoxazole and resistant to aztreonam, colistin, gentamicin, ciprofloxacin and tetracycline [8].

The fifth case was reported. It was a case of 16-year-old perforated appendicitis with the complaints of acute abdominal pain, vomiting and constipation. The microorganism isolated from the peritoneal fluid was found susceptible to ampicillin, ampicillin-sulbactam, ceftazidime, cefazolin, gentamicin, amikacin, ciprofloxacin, imipenem, piperacillin and resistant to ceftriaxone, cefuroxime and trimethoprim-sulfamethoxazole. It was treated with amikacin, ampicillin and clindamycin [3].

The sixth case was an endocarditis case reported. The microorganism isolated from the aortic valve was resistant to piperacillin-tazobactam, imipenem, meropenem, gentamicin and netilmicin and was treated with ciprofloxacin [1].

The seventh case was C. testosteroni bacteremia, isolated from the blood cultures of a patient with diabetes and hemiplegia reported. in 2016. The microorganism was found resistant to aztreonam and colistin [9].

The eighth case was the bacteremia due to C. testosteroni grown in the blood culture of a patient with neutropenia who presented with high fever reported. Cefixime and ceftazidime resistant microorganism was treated with moxifloxacin [10].

Although C. testosteroni can survive for a long time in hospital environments, C. testosteroni infections are community acquired [1]. Gastrointestinal pathologies are often accompanied by intraabdominal infections, and these infections are the most commonly reported group of infections. Risk factors that may cause infections in other cases are the use of central venous catheters, drug injections, skin cuts and subcutaneous lacerations, and surgical procedures [6].

C. testosteroni infections rarely cause death and mostly respond well to antibiotic therapy. In the reported cases, it was susceptible to aminoglycosides, fluoroquinolones, carbapenems, piperecillin-tazobactam, most cephalosporins and trimethoprim-sulfamethoxazole [5,11]. However, it should be kept in mind that antibiotic resistance has increased over the years and the resistance profile may change. C. testosteroni was reported resistant to aminoglycosides in 2009, and resistant to aminoglycosides, carbapenems and piperacillin-tazobactam in 2015 [1,11].

The strain isolated in this case; was found susceptible to ceftazidime (2.0 mg/L), ciprofloxacin (≤ 0.25 mg/L), intermediate susceptible to meropenem (8.0 mg/L ), piperacillin / tazobactam (64.0 mg/L), resistant to gentamicin ( ≥16.0 mg/L), amikacin (≥64.0 mg/L), imipenem (≥16.0 mg/L), trimethoprim-sulfamethaxole (80.0 mg/L). Our patient's urogenital disorder and multiple surgical interventions in this case were predisposing factors for infection.


The isolate in our case was found susceptible to ceftazidime and ciprofloxacin, while it was resistant to preparations such as carbapenem and piperacline-tazobactam, suggesting that it was an infectious agent in the hospital environment due to the widespread use of broad-spectrum antibiotics. With this case report, a rare pathogen was drawn to attention; the importance of rational antibiotic use and the contribution of accurate and rapid diagnosis of microorganisms to treatment with new technologies have been emphasized.



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Conflict of Interest

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Ethics Approval

All procedures performed were under the institutional and/or national research committee's ethical standards and the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This report was supervised and approved by the Ankara City Hospital No.1 clinical research Ethics Committee. (reference no:E1/1539/2021)

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Consent for Publication

Approved by the ethical committee.

Data and Materials Availability

Is available if required.

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All authors contributed to the development of the manuscript. Literature review and manuscript writing were done by Dr. S. Gayenur Büyükberber. All authors read and approved the final manuscript.