Nontyphoidal salmonellosis is a well-known food borne disease that is caused by a Salmonella infection and includes gastroenteritis, bacteremia, and subsequent focal infection. Salmonella infection is known to occur primarily in the small intestine and is self-limiting [1]. The risk factors for this bacterial infection include gastric hypoacidity, recent antibiotic usage, age (the very young and the very old), and an immunosuppressive condition [2].

The literature includes several reports on colonic ulcerations in adults caused by nontyphoidal Salmonella [3,4], but this type of ulceration is considered uncommon in children. Only 2 reports have demonstrated colonic ulcerative changes in children that were due to Salmonella infections [5,6]. One article reported on a 9-month-old girl with colonic ulcers and colonic perforation that were caused by Salmonella typhimurium infection [5], and the other 3 cases of Salmonella gastroenteritis had similar features similar to inflammatory bowel diseases. Endoscopic and histopathological findings demonstrated that a bacterial infection was present [6]. In this article, we report on the case of a 32-month-old healthy female with diffuse left-side colonic ulcers that were caused by a multidrug-resistant Salmonella enteritidis infection.

In comparison to the disease symptoms caused by Salmonella typhi, those caused by nontyphoidal Salmonella are considered less severe. In Korea, a clinical study of 72 children with salmonellosis reported that the clinical outcomes of these children were benign, although the incidence of antibiotic-resistant isolates was increased, and Salmonella group D bacteria was isolated most frequently [7]. However, Gordon and Graham [8] reported that the incidence of invasive salmonellosis has increased among children in Malawi, which is likely to be associated with the emergence of drug-resistant nontyphoidal Salmonella serovars Enteritidis and Typhimurium. In this case, S. enteritidis was isolated and was shown to cause colonic ulceration.

The 4 cases of nontyphoidal salmonellosis with colonic inflammation in children that were reported previously were caused by either S. typhimurium or S. enteritidis [5,6]. The clinical symptoms of previous reports were prolonged or repeated fever, abdominal pain, and nonbloody diarrhea with/without vomiting [5,6]. In our case, the main clinical presentation was copious hematochezia. Bloody diarrhea has been reported to occur in 14.0-41.6% of children with nontyphoidal salmonellosis in Korea [7,9]. Patients with severe Salmonella enteritis have clinical presentations similar to those of patients with inflammatory bowel diseases, such as multiple deep ulcers in the rectum; a descending colon with surrounding mucosal hyperemia and edema; or pancolitis with marked mucosal edema, erythema, loss of haustral folds, and superficial ulcerations throughout the colon [6]. In this case, the endoscopic findings revealed diffuse ulcers in the rectum and sigmoid colon, which were surrounded by edematous and hyperemic mucosa and were easily bruised. Treating patients with symptoms of nontyphoidal Salmonella infection with antimicrobial agents is not recommended owing to the self-limiting nature of the illness, as well as the association between prolonged antibiotic use and the carrier state for the organism [10]. Antimicrobial therapy should be initiated for those patients who are severely ill or with risk factors for extraintestinal spread of infection (e.g., immunocompromised patients, infants aged less than 3 months old, and hemolytic anemia patients) [6,9]. In the present case, antibiotics were administered owing to suspected bacterial enterocolitis caused by Shigella or Escherichia coli (symptoms of high fever, abdominal tenderness, and bloody diarrhea).

The antibiotics that are often administered for Salmonella infection are fluoroquinolones, ampicillin, or third-generation cephalosporins. The recent Korean Nationwide Surveillance Study for Non-Typhoidal Salmonella reported that resistance to trimethoprim-sulfamethoxazole and ampicillin is common, and therefore, the use of a third-generation cephalosporin or quinolone is recommended if the drug susceptibility of the bacteria is unknown [11]. Currently, studies are being conducted to quantify the efficacy of fluoroquinolones in children in areas of the world where multidrug-resistant S. typhimurim is common [12]. Resistance to third-generation cephalosporins is likely to be an increasing clinical problem, especially among children, since these agents are the current drugs of choice for the treatment of bacterial infection [6]. In addition, resistance to third-generation cephalosporins and aminocoglycosides has been reported; however, the bacteria are mainly susceptible to imipenem and meropenem [13] In this case, the S. enteritidis that was isolated from the stool culture was resistant to third-generation cephalosporin, and the initial antibiotic, cefotaxime, administered for treatment was ineffective. After treatment with piperacillin/tazobactam, abdominal pain and the degree of hematochezia improved rapidly and the bacteria were found to be absent from the stool samples.

Nontyphoidal salmonellosis occurs more frequently during the summer months [7] and it may be related to food-borne transmission. The common clinical symptoms of salmonellosis are similar to the symptoms of viral gastroenteritis, such as vomiting, watery diarrhea, and fever [14]. Hand-washing and the strict control of carrier are important for the prevention of salmonellosis.

The present case suggested that nontyphoidal salmonellosis can cause colonic ulcers in children and antibiotic-resistant nontyphoidal Salmonella infection might be associated with the inflammation of the colonic mucosa.