Comamonas kerstersii strains on inpatients with acute appendicitis: review of literature and case report

In this article, we describe 6 cases of patients that presented to the emergency room with symptoms and laboratories compatible with the diagnosis of acute appendicitis. What attracts attention about these six cases are the results of the culture of the tissue, which reveals in these six patients the presence of the bacteria Comamonas kerstersii.

Pre-Publication Release of Accepted Article https://doi.org/10.31005/iajmh.v4i.165 The patient received ciprofloxacin and metronidazole IV for 10 days. Upon completing antibiotics and presenting a favorable progress of the surgical wound, patient was released from the hospital.
The microbiological report of the tissue culture reported Escherichia coli and Comamonas kerstersii.

Case 3
A 29-year-old male patient, without history of relevancy presents to the ER with 12-hour history of abdominal pain located in the hypochondrium and right side of the abdomen.
A peripheral venous blood sample taken at admission showed white blood cell count 14.1 x 10 3 /ul. The patient undergoes conventional appendectomy, where the surgeon found 100 ml of inflammatory liquid and a phlegmonous appendix which was not perforated. A tissue sample was taken by the microbiology department. This patient received ciprofloxacin and metronidazole during his hospitalization. 72 hours later patient was discharged considering his prompt recovery, continuing the medication at home. No complication was reported during his controls.
The microbiological report of the tissue culture reported Escherichia coli and Comamonas kerstersii.

Case 4
A 68-year-old male patient, without relevant history, presents to the emergency department with 3-day history of abdominal pain, which located at the epigastrium but moved afterwards to the lower right quadrant. The patient had taken analgesics and proton pump inhibitors without medical prescription. After being inspected and evaluated by the hospital personnel, the patient underwent a diagnostic laparoscopy and subsequently a laparoscopic appendectomy. A tissue sample was taken by the microbiological department for culture. The patient stayed in the hospital for 24 more hours, and since he did not present any sings of complications was sent home. No complications were reported in subsequent controls.
In the culture of the tissue sample taken from the appendix, a Comamonas kerstersii was isolated along with Escherichia coli.

Case 5
A 16-year-old girl, without relevant history, presents to the emergency room with a 24hour history of abdominal pain, at first located in the mesogastrium that moved toward the right lower quadrant accompanied by nausea, vomit and fever. A peripheral venous blood sample taken at admission showed white blood cell count 10.6 x 10 3 /ul with neutrophil count 9.46 x 10 3 /ul. After initial assessment, the patient was diagnosed acute appendicitis and a conventional appendectomy was performed. During surgery they found 200 ml of inflammatory liquid and a fibrinopurulent retrocecal appendix. A tissue sample was taken by the microbiology department. The patient received ampicillin/sulbactam + metronidazole during her hospitalization period. 24 hours after the surgery the patient is discharged from the hospital. No complication was reported during subsequent controls.
In the culture of the tissue sample taken from the appendix, a Comamonas kerstersii was isolated along with Escherichia coli.

Case 6
A 16-year-old girl with history of psoriasis, presents to the emergency department with a 32-hour history of diffuse abdominal pain, which located later in the right lower quadrant accompanied by nauseas, vomit and fever. Before presenting to the emergency department the patient had taken some analgesics and antibiotics. A peripheral venous blood sample taken at admission showed white blood cell count 19.4 x 10 3 /ul with neutrophil count 16.3 x 10 3 /ul. After assessment, the diagnosis of acute appendicitis was made, so a conventional appendectomy was performed on the patient. During surgery, 200 ml of inflammatory liquid was found along with a plastronated appendix. A tissue sample was taken by the microbiology department for culture. The patient received ampicillin/ sulbactam for antimicrobial therapy. 24 hours after the surgery, considering her prompt recovery, she was discharged from the hospital. No complication was reported during subsequent controls.
In the culture of the tissue sample taken from the appendix, a Comamonas kerstersii was isolated along with Escherichia coli.

Methods and results
The methodology used by the microbiology lab. for identification of species, was carried out-based on obtaining the strains from the precipitate obtained from the different samples. First, sowing was carried out in traditional culture methods (blood agar, MacConkey agar, and chocolate agar), all were grown at a temperature of 35 ± 2 ° C for approximately 24-48 hours until the growth of colonies. Once the colonies were obtained, they were processed by the PHOENIX automated system, which gave the preliminary diagnosis of Comamonas testosteroni.
Since this system does not have other species of Comamonas in its registry, it does not allow to elucidate the diagnosis of other species of this genus. With the preliminary result of C. testosteroni, we proceeded to analyze the strain from the colonies, using MALDI-TOF MS, preparing the strains in wells, letting dry, once the strains of the wells were dried, Matrix was added and let dry again. This process was carried out with each of the samples received, to finally obtain the result of Comamonas kerstersii, in each one of the isolates the Spectral Score was superior to 2,8.

Discussion
C. kerstersii is a nonfermenting betaproteobacterium, Gram-negative, oxidase and catalase-positive bacteria, that are motile largely because of the presence of polar flagella, that was described as an individual species in 2003, after sequencing analysis of the 16s rRNA, recognized as a phytopathogen, widely distributed in the environment (water, soil, and plants) has the ability to survive in aquatic environments, which makes it an opportunistic pathogen for humans; has recently been associated with intraabdominal infection due to perforation of the digestive tract. 6,8,[10][11]13 It has been described that some of the isolates identified as C. testosteroni may have been C. kerstersii, and that the absence of species identification is due to many automated systems, mostly phenotypic identification, only have two types in their records infection. [12][13] The CLSI manual was reviewed, in which no results were found regarding the MIC necessary to consider that there is resistance or sensitivity on the part of Comamonas to antimicrobial strains. [14][15] We describe in Table 1 a comparison of diagnosis methods used for identification of species, MALDI-TOF spectral score obtained and coinfection with another microorganisms reported, between the different cases reported in literature.

Case No
Year of report The diagnosis of C. kerstersii, can be biased due to the lack of records in automated equipment databases, especially those of phenotypic identification.
Methods such MALDI-TOF, polymerase chain reaction and DNA sequencing, allow the correct identification of the different species of these microorganisms.
It is also possible that there have been no previous reports of infections caused by Comamonas species in Ecuador, despite their common distribution in the global environment.
With the previous data and discussion, arises the hypothesis that C. kerstersii infection, that it is a common environmental microorganism, and the practice between people of some places of Ecuador of consumption of non-drinking or unboiled water, could lead to the subsequent colonization of the digestive tract, for that we propose to carry out an environmental study of human drinking water.