Pancreatic cyst fluid harbors a unique microbiome.

BACKGROUND: It is clear that specific intestinal bacteria are involved in the development of different premalignant conditions along the gastrointestinal tract. An analysis of the microbial constituents in the context of pancreatic cystic lesions has, however, as yet not been performed. This consideration prompted us to explore whether endoscopically obtained pancreatic cyst fluids (PCF) contain bacterial DNA and to determine the genera of bacteria present in such material. METHODS: Total DNA was isolated from 69 PCF samples. Bacterial 16S rRNA gene-specific PCR was performed followed by Sanger sequencing and de novo deep sequencing for the V3-V4 variable region of 16S rRNA gene. RESULTS: We observed that 98.2% of the samples were positive in conventional PCR, and that 100% of selected PCF samples (n = 33) were positive for bacterial microbiota as determined by next generation sequencing (NGS). Comprehensive NGS data analysis of PCF showed the presence of 408 genera of bacteria, of which 17 bacterial genera were uniquely abundant to PCF, when compared to the Human Microbiome Project (HMP) database and 15 bacterial microbiota were uniquely abundant in HMP only. Bacteroides spp., Escherichia/Shigella spp., and Acidaminococcus spp. which were predominant in PCF, while also a substantial Staphylococcus spp. and Fusobacterium spp. component was detected. CONCLUSION: These results reveal and characterize an apparently specific bacterial ecosystem in pancreatic cyst fluid samples and may reflect the local microbiota in the pancreas. Some taxa with potential deleterious functions are present in the bacterial abundance profiles, suggesting that the unique microbiome in this specific niche may contribute to neoplastic processes in the pancreas. Further studies are needed to explore the intricate relationship between pathophysiological status in the host pancreas and its microbiota.

Cyst infection of intraductal papillary mucinous neoplasms of the pancreas: management of a rare complication: report of 2 cases.

The purpose of this study was to describe the cyst infection of intraductal papillary mucinous neoplasm in 2 patients. The patients were 62- and 74-year-old men. The initial symptom was acute febrile abdominal pain. Laboratory tests revealed severe infection (C-reactive protein concentrations were 23.3 µg/mL in patient 1 and 22.3 µg/mL in patient 2) and multilocular cystic masses (the diameters were 70 mm in patient 1 and 50 mm in patient 2) at the pancreatic head that involved peripancreatic vessels were demonstrated by computed tomography. Laboratory and radiographic findings were markedly improved by endoscopic transpapillary drainage. The enteric bacteria were detected in the drainage specimens. Curative resection was achieved, and histological findings indicated a carcinoma in situ in patient 1 and an invasive carcinoma in patient 2. Neither hyperamylasemia nor histological fat necrosis, frequently observed in acute pancreatitis, was evident. Both patients were free from recurrence after surgery (17 months in patient 1, and 18 months in patient 2). Cyst infection is an unknown complication of intraductal papillary mucinous neoplasm. Transpapillary drainage is highly recommended as an initial intervention. It is difficult to distinguish between cyst infection and unresectable invasive carcinoma with imaging modalities; however, surgical intervention after drainage may contribute to long-term survival.

An in vitro analysis of microbial transmission during EUS-guided FNA and the utility of sterilization agents.

BACKGROUND: The risk of infection and potential microbial transmission with EUS-guided FNA (EUS-FNA) of cystic lesions remains unknown. OBJECTIVE: We developed an in vitro model to study the incidence of transmucosal microbial transmission during EUS-FNA of cystic lesions and to evaluate the in vitro efficacy of bacteriocidal agent washings of mucosa before FNA under experimental conditions. DESIGN: Conical tubes, 15 mL, filled with aerobic blood culture bottle media were prepared. Then sterile sections of bovine tripe were fastened over the top of the conical tubes in a sterile fashion (conical tube-tripe unit). FNA was performed with 22-gauge FNA needles. A series of 6 experiments were performed. Ten conical tube-tripe units underwent FNA once through the tripe into the blood culture media to ensure sterility. The surface of 10 conical tube-tripe units were inoculated with 50 microL of a 1.5 x 10(8) 1:1 mixture of Escherichia coli (E coli) and Enterococcus sp, and FNA was performed one time into the blood culture media to ensure contamination (controls). The surface of 40 conical tube-tripe units were inoculated with 50 microL of a 1.5 x 10(8) 1:1 mixture of E coli and Enterococcus sp Each of 4 sets of 10 conical tube-tripe units underwent experimental scenarios that consisted of washings with either 1 mL of 0.5% povidone iodine, chlorhexidine, absolute ethanol, or sterile water. FNA was performed once through the tripe into the blood culture media after washing the surface of the tripe. After each conical tube-tripe unit underwent FNA one time, 1 mL blood culture media was obtained and mixed on pour plate agar media and was incubated along with the conical tubes. Microbial evaluation of the conical tubes that contained the blood culture media and pour plates was performed after 48 hours of incubation. SETTING: Gastroenterology and Microbiology Departments of Scott White Memorial Hospital and Clinic in Temple, Texas. INTERVENTIONS: EUS-FNA of cystic lesions. MAIN OUTCOME MEASUREMENTS: Microbial contamination during EUS-FNA of an in vitro cystic environment. RESULTS: A control without E coli and Enterococcus sp was with 0% contamination. A control group with E coli and Enterococcus sp was with 100% contamination; sterile water washings, 100% contamination (P = 1.00); iodine washings, 20% contamination (P < .001); chlorhexidine washings, 80% contamination (P = .47); and absolute ethanol washings, 90% contamination (P = 1.00). Results were compared with our control group by statistical tests of proportions by using the Fisher exact test. CONCLUSIONS: EUS-FNA of sterile cystic lesions resulted in transmucosal microbial contamination. However, our model demonstrated that iodine sterilization of a contaminated mucosal surface produced a very highly statistically significant (P < .001) reduction in the transmission of infectious agents into a sterile environment. This in vitro model could translate into clinical practice by providing evidence that microbial transmission by FNA occurred. The utility of povidone iodine washings could alter procedure methods and patient care.

Pancreaticoduodenectomy for lymphoepithelial cyst of the pancreas.

Lymphoepithelial tumors of the pancreas are rare cystic tumors characterized by the presence of a keratinizing squamous epithelium and a dense lymphoid infiltrate on histologic examination. This case report describes the first lymphoepithelial tumor to be resected from the pancreatic head by pancreaticoduodenectomy. This case is also the first in which the cyst was found to be secondarily infected. The radiologic and clinicopathologic features of these unusual tumors are discussed.

Controversies in the management of pancreatic pseudocysts.

Review of the diagnosis and treatment of patients with pancreatic pseudocysts over the past 8 years has led us to three conclusions regarding controversial aspects of their treatment. We found that patients who present with chronic pseudocysts can be identified with the help of computerized axial tomography and promptly undergo successful internal drainage, whereas patients with acute peripancreatic fluid secondary to pancreatitis can be observed expectantly with a 43 percent frequency of spontaneous resolution. Patients with infected pancreatic pseudocysts can be safely drained internally. The most common cause of extrahepatic biliary obstruction in this group of patients with pancreatic pseudocysts was stricture due to pancreatitis and fibrosis, not extrinsic compression.

Pancreatic abscess with Haemophilus influenzae and Eikenella corrodens.

An infected pancreatic pseudocyst was caused in part by Haemophilus influenzae and Eikenella corrodens. To my knowledge, neither organism has been isolated previously from pancreatic abscesses. I believe that the infecting bacteria originated in the oropharynx and descended through the duodenum.