Current status of post-operative infections due to antimicrobial-resistant bacteria after digestive tract surgery in Japan: Japan Postoperative Infectious Complications Survey in 2015 (JPICS'15)

A Molecular Switch-Integrated Nanoplatform Enables Photo-Unlocked Antibacterial Drug Delivery for Synergistic Abscess Therapy

Drug delivery systems (DDSs) capable of sequential multistage drug release are urgently needed for antibacterial applications. Herein, a molecular switch-integrated, photo-responsive nanoplatform is reported based on hollow mesoporous silica nanospheres (HMSN) loaded with silver nanoparticles (Ag NPs), vancomycin (Van), and hemin (HAVH) for bacteria elimination and abscess therapy. Upon near-infrared (NIR) light irradiation, the molecular switch, hemin, can effuse from the mesopores of HMSN, triggering the release of pre-loaded Ag+ and Van, which enables photothermal-modulated drug release and synergistic photothermal-chemo therapy (PTT-CHT). The HAVH_NIR irreversibly disrupts the bacterial cell membrane, facilitating the penetration of Ag+ and Van. It is found that these compounds restrain the transcription and translation of ribosomes and lead to rapid bacterial death. Furthermore, hemin can effectively inhibit excessive inflammatory responses associated with the treatment, promoting accelerated wound healing in a murine abscess model. This work presents a new strategy for antibacterial drug delivery with high controllability and extendibility, which may benefit the development of smart multifunctional nanomedicine for diseases not limited to bacterial infections.

Mortality related to drug-resistant organisms in surgical sepsis-3: an 8-year time trend study using sequential organ failure assessment scores

The difference in sequential organ failure assessment (SOFA) scores from the baseline to sepsis is a known predictor of sepsis-3 outcome, but the prognostic value of drug-resistant organisms for mortality is unexplained. We employed sepsis stewardship and herein report an observational study. Study subjects were patients admitted to the Departments of Surgery/Chest Surgery from 2011 through 2018 with a diagnosis of sepsis and a SOFA score of 2 or more. Our sepsis stewardship methods included antimicrobial and diagnostic stewardship and infection control. We determined the primary endpoint as in-hospital death and the secondary endpoint as the annual trend of the risk-adjusted mortality ratio (RAMR). For mortality, we performed logistic regression analysis based on SOFA score, age, sex, comorbid disease, and the presence of methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase inhibitor–producing bacteria. In a total of 457 patients, two factors were significant predictors for fatality, i.e., SOFA score of 9 or more with an odds ratio (OR) 4.921 and 95% confidence interval [95% CI] 1.968–12.302 (P = 0.001) and presence of MRSA with an OR 1.83 and 95% CI 1.003–3.338 (P = 0.049). RAMR showed a decrease during the study years (P < 0.05). Early detection of MRSA may help patients survive surgical sepsis-3. Thus, MRSA-oriented diagnosis may play a role in expediting treatment with anti-MRSA antimicrobials.

Postoperative infectious complications caused by multidrug-resistant pathogens in patients undergoing major hepatectomy with extrahepatic bile duct resection

BACKGROUND

Few reports have addressed postoperative infectious complications caused by multidrug-resistant pathogens. The aim of this study was to review the surgical outcomes of patients undergoing major hepatectomy with extrahepatic bile duct resection and to clarify the incidence of and the risk factors for postoperative infectious complications caused by multidrug-resistant pathogens.

METHODS

Medical records of consecutive patients who underwent major hepatectomy with extrahepatic bile duct resection between 2006 and 2017 were retrospectively reviewed.

RESULTS

Among 620 study patients, 219 had postoperative infectious complications, including 62 (10.0%) with postoperative infectious complications caused by multidrug-resistant pathogens. The mortality of the 62 patients with postoperative infectious complications caused by multidrug-resistant pathogens was higher (n = 8, 12.9%) than that in the 157 patients with postoperative infectious complications caused by non-multidrug-resistant pathogens(n = 2, 1.3%) (P < .001). With multivariate analysis, the presence of preoperative cholangitis, the extent of liver resection more than 50%, operative time longer than 600 minutes, the amount of blood loss more than 1500 mL, and the presence of postoperative infectious complications caused by multidrug-resistant pathogens were identified as independent risk factors for postoperative death. The presence of multidrug-resistant pathogens in preoperative bile culture, the amount of blood loss greater than 1500 mL, the presence of bile leakage, and pancreatic fistula were identified as independent risk factors for postoperative infectious complications caused by multidrug-resistant pathogens.

CONCLUSION

The incidence of postoperative infectious complications caused by multidrug-resistant pathogens in patients undergoing major hepatectomy with extrahepatic bile duct resection is high, approximately 10%. This troublesome complication is closely associated with postoperative death. Thus, preventing postoperative infectious complications caused by multidrug-resistant pathogens is an urgent task to improve surgical outcome after major hepatectomy with extrahepatic bile duct resection.