Acute cholangitis with Achromobacter xylosoxidans bacteremia after endoscopic retrograde cholangiopancreatography in hilar cholangiocarcinoma: A case report

Abstract

BACKGROUND

Achromobacter xylosoxidans is a Gram-negative opportunistic aerobe, usually causing nosocomial infections in immunocompromised patients with manifestations including bacteremia, pneumonia, and catheter-related infections. However, A. xylosoxidans have not yet been reported to cause biliary system infections.

CASE SUMMARY

A 72-year-old woman presented to the outpatient department of our hospital with a chief complaint of jaundice. Computed tomography of her abdomen revealed the presence of a mass of approximately 2.4 cm in the hilar portion of the common hepatic duct, consistent with hilar cholangiocarcinoma. We performed endoscopic retrograde cholangiopancreatography (ERCP) to decompress the obstructed left and right intrahepatic ducts (IHDs) and placed 10 cm and 11 cm biliary stents in the left and right IHDs, respectively. However, the day after the procedure, the patient developed post-ERCP cholangitis as the length of the right IHD stent was insufficient for proper bile drainage. The blood culture of the patient tested positive for A. xylosoxidans. Management measures included the replacement of the right IHD stent (11 cm) with a longer one (12 cm) and administering culture-directed antibiotic therapy, solving the cholangitis-related complications. After the cholangitis had resolved, the patient underwent surgery for hilar cholangiocarcinoma and survived for 912 d without recurrence.

CONCLUSION

A. xylosoxidans-induced biliary system infections are extremely rare. Clinical awareness of physicians and endoscopists is required as this rare pathogen might cause infection after endoscopic procedures.

Key Words: Achromobacter xylosoxidans, Bacteremia, Cholangitis, Endoscopic retrograde cholangiopancreatography, Malignant biliary stricture, Cholangiocarcinoma, Case report

Core Tip:Achromobacter xylosoxidans-induced biliary system infections has not been previously described. We present a rare cholangitis case after endoscopic retrograde cholangiopancreatography (ERCP) caused by A. xylosoxidans. Establishing adequate drainage for obstructed bile ducts during ERCP is essential to decrease the risk of post-ERCP cholangitis. In this case, cholangitis developed due to insufficient length of the biliary stent and was resolved by susceptible antibiotic administration and adequate biliary drainage at the second ERCP. As A. xylosoxidans-induced cholangitis has not been previously reported, the A. xylosoxidans contamination source remains unclear. Further investigation is needed to identify the colonization source and prevent endoscopy-associated infections.

INTRODUCTION

Post-endoscopic retrograde cholangiopancreatography (post-ERCP) cholangitis is among the potential adverse events after performing ERCP[1]. The most predominant bacteria identified in blood cultures of patients with post-ERCP cholangitis are the intestinal flora[2].

Achromobacter xylosoxidans, a non-fermenting, aerobic Gram-negative bacillus found primarily in contaminated water or soil[3], is a causative agent of bacteremia, pneumonia, catheter-associated infections, meningitis, cellulitis, and endocarditis[3-5] in immunocompromised patients with neoplasia, organ transplantation[6], or history of foreign device insertion (e.g., endotracheal tubes and catheters)[7]. However, A. xylosoxidans has not been reported to cause biliary system infections.

In this case report, we present a patient with cholangiocarcinoma who developed A. xylosoxidans-induced post-ERCP cholangitis and bacteremia.

CASE PRESENTATION

Chief complaints

A 72-year-old woman presented to the outpatient department of our hospital with a chief complaint of jaundice and recurrent epigastric pain.

History of present illness

The symptoms of the patient began 1 mo prior with recurrent episodes and no history of fever, chills, or vomiting.

History of past illness

The patient had no significant history.

Personal and family history

The patient was a non-smoker who denied alcohol abuse and exhibited no significant family medical history.

Physical examination

The physical examination of the patient did not reveal tenderness or signs of peritoneal irritation. The bowel sounds of the patient were normal. At the outpatient clinic, the blood pressure, pulse rate, and temperature of the patient were 130/83 mmHg, 67 beats/min, and 36.8 °C, respectively.

Laboratory examinations

Our laboratory investigations of the patient indicated increased cholestatic parameters with total bilirubin of 12.7 mg/dL (normal range: 0.3–1.2 mg/dL), aspartate aminotransferase (AST) of 227 IU/L (normal range: 0–35 IU/L), alanine aminotransferase (ALT) of 229 IU/L (normal range: 0–35 IU/L), alkaline phosphatase (ALP) of 456 IU/L (normal range: 30–120 IU/L), and gamma-glutamyl transferase of 420 IU/L (normal range: 9–64 IU/L). The white blood cell count (8600/μL) and C-reactive protein (0.5 mg/dL) values of the patient were within normal range.

Imaging examinations

Computed tomography of the abdomen revealed the presence of a mass of approximately 2.4 cm in size at the hilar portion of the common hepatic duct and a dilated intrahepatic duct. We admitted the patient and administered ceftizoxime, a third-generation prophylactic cephalosporin antibiotic, prior to performing ERCP for biliary decompression and hilar mass tissue sampling. After deep biliary cannulation, we sampled the bile duct mass in the hilum with biopsy forceps and confirmed it to be an adenocarcinoma. For cholestasis resolution, we attempted endoscopic biliary drainage both in the left and right intrahepatic ducts (IHDs). We placed a 7 Fr, 10 cm, and 11 cm endoscopic retrograde biliary drainage (ERBD) stent (Zimmon^® Biliary Stent; Cook Medical, Bloomington, IN, United States and Cotton-Leung^® Biliary Stent; Cook Medical, respectively) in the left and right IHD, respectively. However, the length of the stent in the right IHD appeared to be insufficient for proper drainage (Figure 1). Although we attempted to replace the stent in the right IHD with a longer one, we terminated the procedure due to the lack of cooperation from the patient and the prolonged procedure time.

Figure 1 Proximal end of the biliary stent inserted into the right intrahepatic duct was adjacent to the hilum (arrowhead), indicating that the length of the stent was potentially insufficient to ensure adequate biliary drainage.

A day after the index ERCP, the patient presented with fever, chills, severe epigastric pain, and increased body temperature (38.7 °C). Laboratory testing revealed an increased white blood cell count (15000/μL) and C-reactive protein level (9.35 mg/dL). We still recorded increased liver enzyme levels (total bilirubin 11.83 mg/dL, AST 206 IU/L, ALT 158 IU/L, and ALP 420 IU/L).

According to the guidelines of the European Society of Gastrointestinal Endoscopy, we diagnosed the patient with moderate post-ERCP cholangitis[1]. We collected two sets of blood samples in BACTEC^TMPlus aerobic/F culture vials (Becton Dickinson and Company, Franklin Lakes, NJ, United States) from the peripheral veins for blood culture, and administered empirical broad-spectrum antibiotics (piperacillin/tazobactam). Both blood cultures tested positive for Gram-negative bacilli (A. xylosoxidans). The pathogen exhibited susceptibility to cefepime, ceftazidime, imipenem, meropenem, piperacillin/tazobactam, ticarcillin/clavulanic acid, and trimethoprim/sulfamethoxazole while displaying resistance to amikacin, aztreonam, ciprofloxacin, gentamicin, and tobramycin (Table 1).

Table 1 Antibiogram of Achromobacter xylosoxidans.

Antibiotic	MIC	Interpretation CLSI 2016
Amikacin	> 32	R
Aztreonam	> 16	R
Cefepime	8	S
Cefotaxime	32	I
Ceftazidime	4	S
Ciprofloxacin	> 2	R
Gentamicin	> 8	R
Imipenem	≤ 1	S
Levofloxacin	≤ 2	S
Meropenem	≤ 1	S
Piperacillin-tazobactam	≤ 16	S
Trimethoprim-sulfamethoxazole	≤ 2/38	S

CLSI: Clinical and Laboratory Standards Institute; I: Intermediate; MIC: Minimum inhibitory concentration (μg/mL); R: Resistant: S: Susceptible.

FINAL DIAGNOSIS

The final diagnosis was A. xylosoxidans-induced post-ERCP cholangitis.

TREATMENT

We performed a follow-up ERCP at 2 d after the index ERCP to achieve adequate biliary drainage. During the second ERCP, purulent pus, which was not visible during the index procedure, was discharged from the ampulla (Figure 2A). The 11 cm long ERBD stent placed in the right IHD was replaced with a 7 Fr, 12 cm ERBD stent (Zimmon® Biliary Stent; Cook Medical) (Figure 2B). We continued the antibiotic administration as the clinical symptoms alleviated and the laboratory results indicated improvement. We obtained subsequent blood cultures on day 5 of antibiotic treatment, testing negative for bacteremia. The patient was discharged after 14 d of antibiotic treatment.

Figure 2 Images of follow-up endoscopic retrograde cholangiopancreatography. A: Purulent pus was discharged from the ampulla; B: Adequate biliary drainage was achieved after the placement of a longer biliary stent.

OUTCOME AND FOLLOW-UP

After cholestasis had resolved, the patient was readmitted and underwent left lobectomy and bile duct resection for hilar cholangiocarcinoma. The patient was followed up for 912 d after surgery without recurrence. The disease-free survival and overall survival were 912 d.

DISCUSSION

A. xylosoxidans was first reported by Yabuuchi and Oyama[8] in 1971, isolated from the ear discharge of patients with chronic otitis media. A. xylosoxidans is an opportunistic and less virulent pathogen, with most of its caused infections being nosocomial (often associated with foreign device contaminations)[9]. The two most common clinical manifestations of A. xylosoxidans infection are catheter-associated bacteremia and pneumonia[10]. Urinary tract, soft tissue, central nervous system, and bone infections as well as endocarditis have been less commonly reported in case reports[3]. An intra-abdominal abscess caused by A. xylosoxidans after performing cholecystectomy was described in Taiwan[11]. However, to the best of our knowledge, no studies reported acute cholangitis associated with A. xylosoxidans infection, especially after ERCP.

Post-ERCP cholangitis is a rare ERCP-associated adverse event with an incidence of approximately 0.4%[12]. Inadequate biliary drainage of an obstructed bile duct filled with contrast is the major risk factor for post-ERCP cholangitis[13], considered to occur due to increased intraductal pressure causing biliary-venous reflux[14]. Therefore, ensuring intact bile and contrast flow by endoscopists during the procedure is crucial to prevent post-ERCP cholangitis, especially in cases of malignant stricture. However, various factors such as bile duct tortuosity or patient deterioration make the drainage of certain bile duct segments challenging[15-19]. In this case, we noticed that the stent in the right IHD was not long enough during the index ERCP. However, further procedures could not be performed as the patient recovered from conscious sedation and did not cooperate due to the prolonged procedure time. This incomplete procedure might have led to the development of post-ERCP cholangitis, which was resolved by replacing the previous stent with one of sufficient length.

Preoperative biliary drainage modalities in the case of hilar cholangiocarcinoma also merit discussion. The optimal biliary drainage approach, whether ERCP or percutaneous transhepatic biliary drainage (PTBD), remains unclear. The choice between these two modalities is influenced by factors such as local expertise, disease complexity, patient condition, and preference[20]. Several meta-analyses[21-23] described that ERCP is associated with higher procedure-related adverse event rates. However, the robustness of the findings might be compromised by the limited included RCT numbers[24]. Although certain studies advocate PTBD for its capacity to drain specific bile ducts[25,26], PTBD reportedly carries a higher risk of cancer seeding through the track than ERCP[27]. In contrast, compared to PTBD, ERCP is reportedly coupled with shorter hospital stays and less patient discomfort and pain[28]. Therefore, we opted for ERCP as the initial approach in the case of this patient. Although post-ERCP cholangitis developed due to the insufficient length of the biliary stent, the placement of a longer stent and appropriate antibiotic therapy solved the cholangitis-related concerns.

Enteric bacteria (e.g., Enterococcus faecium and Escherichia coli) are reportedly the most common pathogens responsible for post-ERCP cholangitis[2,14]. As A. xylosoxidans-induced cholangitis has not been reported before, the A. xylosoxidans infection source remains unclear. Foreign devices, especially intravascular catheters, have been established as major entry portals for pathogens into the bloodstream[4,7]. In this case, the ERBD stent was very unlikely the source of bacteremia as it did not break the barriers between the body and the external environment as intravascular catheters do[25].

A. xylosoxidans is a well-established nosocomial colonizer, isolated from various healthcare devices such as dialysis solutions, disinfectants, and mechanical ventilators[7,9]. Therefore, we think that the duodenoscope might be a potential infection source. In recent years, ERCP procedure-associated multidrug-resistant organisms emerged[26,27]. Numerous medical studies concluded that an elevator, the unique structure of the duodenoscope makes its cleansing difficult and inadequate[28]. Although we suspected the duodenoscope as an infection source, no massive infectious outbreak has occurred in our endoscopy suite to date, as no other patients have developed post-ERCP cholangitis associated with A. xylosoxidans, except for this one.

A. xylosoxidans is resistant to a broad spectrum of antibiotics[29]. Although wild-type strains are resistant to first- and second-generation cephalosporins, cefotaxime, ceftriaxone, and aminoglycosides, they are susceptible to piperacillin, cefepime, ceftazidime, fluoroquinolones, and colistin[3]. In particular, piperacillin-tazobactam is an agent to which A. xylosoxidans is susceptible[30]. Although strains harboring chromosomal OXA-114-like beta-lactamase, resistant to piperacillin and carbapenems have been reported[31,32], the strain in this case was susceptible to piperacillin-tazobactam. Therefore, A. xylosoxidans bacteremia was resolved without the need for combination therapy or broad-spectrum agents.

CONCLUSION

In this study, we presented the first case of A. xylosoxidans-induced post-ERCP cholangitis and bacteremia. Clinical awareness of physicians and endoscopists would be essential as this rare pathogen might cause infection after endoscopic procedures. Further investigations would be required to determine colonization sources and prevent endoscopy-associated infections.