Enrichment of oral microbiota in early cystic precursors to invasive pancreatic cancer.

OBJECTIVES: Intraductal papillary mucinous neoplasms (IPMNs) are pancreatic cysts that can progress to invasive pancreatic cancer. Associations between oncogenesis and oral microbiome alterations have been reported. This study aims to investigate a potential intracystic pancreatic microbiome in a pancreatic cystic neoplasm (PCN) surgery patient cohort. DESIGN: Paired cyst fluid and plasma were collected at pancreatic surgery from patients with suspected PCN (n=105). Quantitative and qualitative assessment of bacterial DNA by qPCR, PacBio sequencing (n=35), and interleukin (IL)-1ß quantification was performed. The data were correlated to diagnosis, lesion severity and clinical and laboratory profile, including proton-pump inhibitor (PPI) usage and history of invasive endoscopy procedures. RESULTS: Intracystic bacterial 16S DNA copy number and IL-1ß protein quantity were significantly higher in IPMN with high-grade dysplasia and IPMN with cancer compared with non-IPMN PCNs. Despite high interpersonal variation of intracystic microbiota composition, bacterial network and linear discriminant analysis effect size analyses demonstrated co-occurrence and enrichment of oral bacterial taxa including Fusobacterium nucleatum and Granulicatella adiacens in cyst fluid from IPMN with high-grade dysplasia. The elevated intracystic bacterial DNA is associated with, but not limited to, prior exposure to invasive endoscopic procedures, and is independent from use of PPI and antibiotics. CONCLUSIONS: Collectively, these findings warrant further investigation into the role of oral bacteria in cystic precursors to pancreatic cancer and have added values on the aetiopathology as well as the management of pancreatic cysts.

Acute obstructive suppurative pancreatic ductitis (AOSPD) in pancreatic cancer treated by nasopancreatic drainage.

An 80-year-old woman with pancreatic cancer was admitted with fever and abdominal pain. Blood examinations showed an elevated CRP level. On computed tomography (CT), a pancreatic tumor with a dilated upstream main pancreatic duct (MPD) was seen. Endoscopic retrograde cholangiopancreatography (ERCP) showed the strictured part of the MPD at the head of the pancreas with upstream dilatation. A nasopancreatic drainage tube was placed. Through the tube, purulent pancreatic juice was discharged and culture of the pancreatic juice grew Klebsiella pneumoniae. On the day after ERCP, the patient's condition and the laboratory results improved. The patient's disorder was diagnosed as acute obstructive suppurative pancreatitis with pancreatic cancer.

"Primary bacterial culture of bile and pancreatic juice in tumor related jaundice (TROJ) - is ascending cholangitis always our fault?"

INTRODUCTION: TROJ (tumor-related obstructive jaundice) is one of the most common indications for endoscopic retrograde choleopancreatography (ERCP) with endoscopic biliary stenting. Despite the effectiveness of this procedure, especially in palliative patients, it is not without flaws. Ascending bacterial cholangitis, a common stenting complication, occurs in about 0.5-1.7% of cases. The authors' intention was to investigate whether this complication occurs solely due to the procedure or whether it is a result of an underlying bacterial infection in the dilated, obstructed bile and pancreatic ducts. METHODS: Sixteen patients with painless obstructive jaundice related to a tumor located in or in the proximity of the bile duct were enrolled for this study. Prior to endoscopic palliative stenting we harvested bile and pancreatic fluid and the proceeded with the initial procedure. RESULTS: In 14 cases (87.5%) we managed to restore the patency of the bile duct endoscopically. Additionaly, we observed that in 13 cases (81.25%) bacteria were present in the bile and/or pancreatic fluid. The most common pathogen was Streptococcus mitis - present in 7 cases (43.75%). The most effective antibiotics for discovered S. mitis strains were cefuroxime and vancomycin. CONCLUSION: Primal bacterial pathogenes may be present in obstructed bile and pancreatic ducts prior to endoscopic intervention. The connection between Streptocccus mitis and TROJ needs further investigation.

Helicobacter pylori is undetectable in intraductal papillary mucinous neoplasm.

BACKGROUND: About half of the world population is infected with Helicobacter pylori (H. pylori), a bacterium associated with gastric cancer and considered to be a risk factor for pancreatic ductal adenocarcinoma. Whether the bacterium is associated with intraductal papillary mucinous neoplasm, believed to be a precursor of pancreatic ductal adenocarcinoma, is unknown. The aim of this study was to investigate the presence of H. pylori DNA in tissue sections of intraductal papillary mucinous neoplasm. METHODS: The presence of H. pylori DNA was tested in a retrospective controlled study of formalin-fixed, paraffin-embedded pancreatic tissues from 24 patients who underwent surgery for intraductal papillary mucinous neoplasm. Histologically normal tissues surrounding neoplasms were used as control. H. pylori DNA was evaluated after deparaffinization, DNA extraction, and purification, and results were evaluated statistically. RESULTS: Samples were collected from 13 males and 11 females with mean age 59 years (range 44-77), and consisted of 19 cases of main-duct and three cases of branched-duct intraductal papillary mucinous neoplasm. Two patients were diagnosed with pancreatic cancer and main-duct intraductal papillary mucinous neoplasm. H. pylori DNA was not detected either in intraductal papillary mucinous neoplasm tissue, or in surrounding normal tissue. CONCLUSIONS: Although H. pylori has been implicated in pancreatic ductal adenocarcinoma, it may not play a key role in the development of intraductal papillary mucinous neoplasm.

Effects of infliximab on bacterial translocation in experimental acute necrotizing pancreatitis.

BACKGROUND & OBJECTIVES: Translocation of bacteria from the gut is an important factor in the development of septic complications and mortality in acute pancreatitis (AP). The present study was designed to assess the effects of infliximab treatment on bacterial translocation (BT) in experimental acute necrotizing pancreatitis. METHODS: Male Sprague-Dawley rats (n=45) were allocated into three groups. AP was induced in group II (positive control, n=15) and group III (Infliximab; n=15) by retrograde injection of taurocholate into the common biliopancreatic duct. Group I rats (Sham; n=15) received normal saline infusion into the common biliopancreatic duct as placebo. Groups I and II were treated by normal saline and group III was treated with infliximab intraperitoneally on 6, 30 and 54 h after induction of pancreatitis. All surviving animals were killed 60 h after the induction of pancreatitis, and specimens were collected for amylase measurement as well as histopathologic and microbiologic examinations. RESULTS: Oedema, acinar cell necrosis, inflammatory infiltration, haemorrhage, fat necrosis and perivascular inflammation in group III rats were decreased with infliximab treatment when compared with group II (P<0.001). BT to mesentery lymph node in groups I, II and III were 20, 100 and 46 per cent, respectively. BT to peritoneum and pancreas in group III was lower than group II (P<0.05). INTERPRETATION & CONCLUSIONS: Infliximab administration resulted in beneficial effects on BT and histopathologic changes in the experimental necrotizing pancreatitis. Whether anti-TNF therapy has a role in prevention of complications of ANP needs to be established.

Establishment of an infected necrotizing pancreatitis model by retrograde pancreatic duct injection of sodium taurocholate and E. coli in rats.

A stable and reliable infected necrotizing pancreatitis (INP) model in rats was established in order to study the pathophysiological mechanism and pathological development rule of INP and explore the new therapeutic methods for the diseases. Forty-six SD rats were randomly divided into 5 groups. The animals in group A received the injection of 5% sodium taurocholate into the pancreatic duct and those in group B underwent that of E. coli into the pancreatic duct. The rats in groups C, D and E were subjected to the injection of 5% sodium taurocholate in combination with different concentrations of E. coli (10(3), 10(4), 10(5)/mL, respectively) into the pancreatic duct. The dose of injection was 0.1 mL/100 g and the velocity of injection was 0.2 mL/min in all the 5 groups. Eight h after the injection, the survival rate of animals was recorded and the surviving rats were killed to determine the serum content of amylase and perform pathological examination and germ cultivation of the pancreatic tissue. The results showed that acute necrotizing pancreatitis model was induced by injection of 5% sodium taurocholate into the pancreatic duct. The positive rate of germ cultivation in group A was 12.5%. The acute necrotizing pancreatitis model was not induced by injection of E. coli into the pancreatic duct and the positive rate of germ cultivation in group B was 0. The INP model was established in groups C to E. The positive rate of germ cultivation was 60%, 100% and 100% and 8-h survival rate 100%, 100% and 70% in groups C, D and E, respectively. It was concluded that a stable and reliable model of INP was established by injection of 5% sodium taurocholate in combination with 10(4)/mL E. coli into the pancreatic duct with a dose of 0.1 mL/100 g and a velocity of 0.2 mL/min. The pathogenesis of INP might be that the hemorrhage and necrosis of pancreatic tissue induced by sodium taurocholate results in weakness of pancreatic tissue in fighting against the germs. Meanwhile, the necrotic pancreatic tissue provides a good proliferative environment for the germs.

Establishment of an infected necrotizing pancreatitis model by retrograde pancreatic duct injection of sodium taurocholate and E. coli in rats / 华中科技大学学报（医学）（英德文版）

A stable and reliable infected necrotizing pancreatitis (INP) model in rats was established in order to study the pathophysiological mechanism and pathological development rule of INP and explore the new therapeutic methods for the diseases. Forty-six SD rats were randomly divided into 5 groups. The animals in group A received the injection of 5% sodium taurocholate into the pancreatic duct and those in group B underwent that of E. coli into the pancreatic duct. The rats in groups C, D and E were subjected to the injection of 5% sodium taurocholate in combination with different concentrations of E. coli (10(3), 10(4), 10(5)/mL, respectively) into the pancreatic duct. The dose of injection was 0.1 mL/100 g and the velocity of injection was 0.2 mL/min in all the 5 groups. Eight h after the injection, the survival rate of animals was recorded and the surviving rats were killed to determine the serum content of amylase and perform pathological examination and germ cultivation of the pancreatic tissue. The results showed that acute necrotizing pancreatitis model was induced by injection of 5% sodium taurocholate into the pancreatic duct. The positive rate of germ cultivation in group A was 12.5%. The acute necrotizing pancreatitis model was not induced by injection of E. coli into the pancreatic duct and the positive rate of germ cultivation in group B was 0. The INP model was established in groups C to E. The positive rate of germ cultivation was 60%, 100% and 100% and 8-h survival rate 100%, 100% and 70% in groups C, D and E, respectively. It was concluded that a stable and reliable model of INP was established by injection of 5% sodium taurocholate in combination with 10(4)/mL E. coli into the pancreatic duct with a dose of 0.1 mL/100 g and a velocity of 0.2 mL/min. The pathogenesis of INP might be that the hemorrhage and necrosis of pancreatic tissue induced by sodium taurocholate results in weakness of pancreatic tissue in fighting against the germs. Meanwhile, the necrotic pancreatic tissue provides a good proliferative environment for the germs.

Bacterial biofilm within diseased pancreatic and biliary tracts.

BACKGROUND: Bacterial community structures in human pancreatic and biliary tracts were evaluated. METHODS: Gall bladder stones from 153 patients, 20 gall bladder walls, six common duct stones, 52 biliary stents, 21 duodenal biopsies, nine pancreatic duct biopsies, and five bile ducts were investigated using fluorescence in situ hybridisation (FISH) with ribosomal RNA targeted Cy3/Cy5 (carbocyanine) labelled oligonucleotide probes. RESULT: Duodenal, gall bladder, and bile duct walls were free of bacteria. A dense multispecies bacterial biofilm was present within the pancreatic duct of patients with calcific pancreatitis and within biliary stents, irrespective of diagnosis. The concentration, density, and amenability of the biofilm to FISH and DNA staining declined progressively with the grade of stent occlusion. The lowest detectable bacterial concentrations were found by FISH in completely occluded stents and brown/mixed gall stones. Bacteria were not detectable with FISH in cholesterol gall stones. CONCLUSIONS: A wide range of different branches and groups of bacteria participate in the development of biofilms on the surfaces of foreign bodies, such as biliary stents, mixed gall stones, or calcific pancreatic ducts, but not on the surface of pure cholesterol gall stones. Occlusion of stents leads to progressive extinction of the biofilm and mummification of its components. Deposition of cholesterol or other substances within the biofilm matrix may be a novel mechanism of host defence against bacteria present in these biofilms.

Do pancreatic duct stents cause or prevent pancreatic sepsis?

BACKGROUND: Pancreatic sepsis can occur after contrast injection into an obstructed or disrupted pancreatic duct. Whether stents cause or prevent pancreatic sepsis is unknown. Accordingly, the pancreatic duct bacteriology in patients with pancreatic duct stents was retrospectively reviewed and contrasted with biliary cultures taken from patients at the time of bile duct stent retrieval and/or exchange. METHODS: Of 61 patients (29 men, 32 women; 72 stents; mean age 51 [16] years, range 14-88 years), 36 with pancreatic duct stents had pancreatic duct cultures obtained at the time of stent exchange and/or retrieval. The results of these cultures were compared with bile duct cultures taken from 36 patients at the time of biliary stent exchange/retrieval. Eleven of the 36 patients with pancreatic duct stents also had bile duct stents. Data collected included stent patency, clinical sepsis at initial stent placement or retrieval, administration of antibiotics before the procedure, indication for stent placement, stent duration, and culture results. RESULTS: At stent retrieval and/or exchange, all 61 patients with pancreatic and/or biliary stents had contamination of the respective ducts with multiple enteric bacteria (mean 3.4 organisms in patients with pancreatic duct stents vs. 3.3 in those with bile duct stents). Clostridium perfringens was found in 17% and 0% of patients with, respectively, bile duct and pancreatic duct stents. Among the most common indications for pancreatic duct stent placement were stricture (28), sphincterotomy (9), leak (7), stones (3), and dilated pancreatic duct (1). Indications for a biliary stent included benign stricture (29), malignancy (6), stones (2), cholangitis (1), chronic pancreatitis (1), and dilated common bile duct (1). Pancreatic cultures were taken at a median of 85 days (interquartile range 60-126; range 13-273) and biliary cultures at a median of 87 days (interquartile range 45-149; range 19-927) after stent placement. Eleven patients, 6 with a bile duct stent, 4 with a pancreatic duct stent, and one with dual stents, developed pre-exchange/retrieval clinical sepsis; 3 had pancreatic sepsis. All had received antibiotics at initial placement. In the 11 patients with sepsis (12 stents), 8 stents were completely occluded at exchange/retrieval, 3 were partially occluded, and one was patent. In 50 patients (60 stents), no clinical sepsis developed; 7 stents were patent, 31 partially occluded, and 22 completely obstructed. CONCLUSIONS: (1) Comparable to patients with biliary stents, all patients with pancreatic stents had contamination of the pancreatic ductal system by enteric flora. (2) In contrast to the 17% of patients with bile duct stents who had intraductal Clostridium perfringens, there were no instances of contamination with this organism in patients with pancreatic stent (p = 0.025), although, after adjusting for multiple comparisons, statistical significance was lost. (3) There was a tendency for stent occlusion to predispose to pancreatic sepsis, but occlusion by itself was insufficient (p = 0.106). (4) Further investigation is required to define the additional variables that are associated with the development of pancreatic sepsis.

Sources of pancreatic pathogens in acute pancreatitis in cats.

The source(s) of pancreatic pathogens is uncertain, although the colon is usually implicated. We studied whether pathogens may spread from different sites in a feline model of the disease. Acute pancreatitis was induced using a standard technique and a distinctive clinical strain of Escherichia coli as the marker bacterium. E. coli were placed in the colon, gall bladder, main pancreatic duct, or obstructed renal pelvis of control cats (no pancreatitis) and acute pancreatitis cats. Pancreases were colonized from each source, whether or not pancreatitis was present. The pancreatic colonization rate was greater in acute pancreatitis only when E. coli had been placed in the colon. In conclusion, E. coli may spread to the pancreas from different sources. The high rate of pancreatic colonization in both control and inflamed glands suggested that, clinically, bacteria may spread to the pancreas more frequently than is currently thought.

Bile pancreatitis.

Bile pancreatitis was studied both macropathologically and histopathologically in cases with an abnormal pancreatic choledochoductal junction, in which free communication between the pancreatic duct and the common bile duct occurred. The intraductal pressure of the pancreatic duct is normally higher than that of the bile duct, therefore, the pancreatic juice flows into the bile duct. In this study, we found squamous carcinoma cells from an adeno-squamous cell carcinoma of the gall-bladder in the main pancreatic duct. Hence, the possibility of bile reflux into the pancreatic duct was also considered. Outstanding findings, such as degeneration and disappearance of the pancreatic ductal epithelium, intraluminal aggregation of bacilli, and diffuse interlobular fibrosis were found in four of 15 cases with an abnormal junction. Similar ductal alterations and diffuse fibrosis were found neither in the controls nor in the remaining 11 cases. Therefore, it appears that pancreatic disorders due to the reflux of bile occurs in the presence of bacteria.

Infectious complications of endoscopic retrograde cholangiopancreatography. A prospective assessment.

A prospective assessment of the bacterial complications of endoscopic retrograde cholangiopancreatography (ERCP) was made in 97 unselected patients undergoing 101 endoscopies. Blood cultures were taken before and five and ten minutes after completion of the procedure. In an attempt to identify a potential source of infection, aspirates were taken from the pancreaticobiliary duct (PBD) after injection of contrast material. Blood cultures from all procedures were negative. In 14 patients PBD aspirates yielded Pseudomonas aeruginosa, pyocin type 22 and serotype O6, suggesting a common source for this organism. Isolation of this strain ceased after more rigorous cleansing and disinfection of the endoscope. The occurrence of bacteremia following ERCP is low, but there is a risk of transmission of potential nosocomial pathogens with this procedure.