Next-generation microbiological testing in intraabdominal infections with PCR technology

PURPOSE

Intraabdominal infections (IAI) are increasing worldwide and are a major contributor to morbidity and mortality. Among IAI, the number of multi-drug resistant organisms (MDRO) is increasing globally. We tested the Unyvero A50® for intraabdominal infections, compared the detected microorganisms and antibiotic resistance, and compared the results with those of routine microbiology.

METHODS

We prospectively compared samples obtained from surgical patients using PCR-based Unyvero IAI cartridges against routine microbiology for the detection of microorganisms. Additionally, we identified clinical parameters that correlated with the microbiological findings. Data were analyzed using the t-test and Mann-Whitney U test.

RESULTS

Sixty-two samples were analyzed. The PCR system identified more microorganisms, mostly Bacteroides species, Escherichia coli, and Enterococcus spp. For bacterial resistance, the PCR system results were fully concordant with those of routine microbiology, resulting in a sensitivity, specificity, and positive and negative predictive value (PPV, NPV) of 100%. The sensitivity, specificity, PPV, and NPV for the detection of microorganisms were 74%, 58%, 60%, and 72%, respectively. CRP levels were significantly higher in patients with detectable microorganisms. We identified more microorganisms and bacterial resistance in hospital-acquired intra-abdominal infections by using the PCR system.

DISCUSSION

IAI warrants early identification of the microorganisms involved and their resistance to allow for adequate antibiotic therapy. PCR systems enable physicians to rapidly adjust their antibiotic treatment. Conventional microbiological culture and testing remain essential for determining the minimal growth inhibition concentrations for antibiotic therapy.

Takeaways from the Recarbrio Conundrum: Has the FDA Jumped the Gun?

Recarbrio is a novel antibiotic approved by US-FDA. It was initially found to be useful in treating various resistant gram negative infections. A recent investigation revealed lack of methodological and scientific integrity behind the process of FDA approval for this drug. This incident is a lesson for us that we shall not consider FDA clearance as the gold standard before approving any drug in the Indian market or start using it before having adequate data from our own clinical settings.

Efficacy and safety of tazobactam/ceftolozane in combination with metronidazole for intraabdominal infection in a hepato-biliary-pancreatic field in clinical practice

INTRODUCTION

This single-center study evaluated the efficacy and safety of tazobactam/ceftolozane (TAZ/CTLZ) in combination with metronidazole for intraabdominal infection in a hepato-biliary-pancreatic field in clinical practice.

METHODS

This study included 50 patients, including 35 with intraabdominal abscess or peritonitis, 5 with liver abscess, 4 with cholecystitis, and 6 with cholangitis with sepsis. Of the 50 patients, 29 received TAZ/CTLZ and metronidazole after a prior antibacterial therapy failure, including tazobactam/piperacillin, cefmetazole, and levofloxacin. Source control was performed in 36 patients.

RESULTS

The clinical response could be evaluated in 49 patients. The clinical cure rate at end-of-therapy was 91.8% (45 of 49 patients) and that at test-of-cure was 89.6% (43 of 48 patients). Of 5 patients in whom clinical response at test-of-cure was a failure, 1 developed infectious disease during chemoradiotherapy for recurrent cancer and 4 after liver resection or pancreatoduodenectomy. Three of the 4 patients were associated with pancreatic juice leakage. Isolated pathogens were eradicated or presumably eradicated in 27 of 31 (87.1%) patients in whom microbiological response at test-of-cure could be evaluated. The response rate for AmpC-producing Enterobacteriaceae was 87.5%. Nausea was observed in two patients. Aspartate and alanine aminotransferase activities were increased in 3 of the 50 (6.0%) patients. The activities improved after the antibiotic discontinuation.

CONCLUSIONS

This observational study demonstrated that TAZ/CTLZ in combination with metronidazole has a favorable effect without major drug-related adverse events for intraabdominal infection in the hepato-biliary-pancreatic field in clinical practice although the efficacy of TAZ/CTLZ may decrease in compromised patients.

Optimal Antibiotic Duration for Bloodstream Infections Secondary to Intraabdominal Infection

BACKGROUND

Bloodstream infections (BSIs) secondary to intraabdominal infections (IAIs) are common in the intensive care unit (ICU). The Surgical Infection Society guidelines recommend treatment duration after achieving source control in patients with secondary bacteremia; however, literature supporting this recommendation is limited. The purpose of this study was to compare outcomes in patients who received shorter versus extended duration of antibiotics for bacteremia secondary to IAI.

MATERIALS AND METHODS

A retrospective cohort analysis was conducted in adult surgical ICU patients (n = 42) with BSIs and source control procedure(s) for IAI. The primary outcome was recurrent IAI. Secondary outcomes included surgical site infections (SSIs), Clostridium difficile infections (CDIs), secondary fungal infections, and in-hospital mortality.

RESULTS

Forty-two patients met inclusion criteria and were divided into groups according to antimicrobial duration; 12 patients received <7 d, and 30 patients received >7 d of antibiotics. There were no differences in baseline characteristics between the two cohorts except for the presence of sepsis [4/12 (33.3%) versus 27/30 (90.0%); P = 0.001]. Thirty-one percent (13/42) of all organisms isolated from blood cultures were gram-negative bacteria, 12/42 (28.6%) were MDROs, and 2/42 (4.8%) patients experienced a culture mismatch in which cultured bacteria were not susceptible to empiric antibiotic therapy. Rates of recurrent IAI were similar between the two cohorts [1/12 (8.3%) versus 4/30 (13.3%), P = 0.554].

CONCLUSIONS

Among surgical ICU patients with BSI secondary to IAI, cessation of antibiotic therapy within 7 d of source control was not associated with an increased incidence of recurrent IAI.

The role of anticoagulation in pylephlebitis: a retrospective examination of characteristics and outcomes

Pylephlebitis, or suppurative thrombophlebitis of the portal vein, typically occurs in the context of an intraabdominal infection or abdominal sepsis. Antibiotics are the mainstay of treatment. The role of anticoagulation in the management of pylephlebitis is controversial, and data regarding its impact on outcomes is limited. The records of 67 consecutive patients with pylephlebitis treated at our institution over a 19 year period were retrospectively reviewed. Data was gathered regarding their baseline characteristics, presentations, management, and outcomes. Patients who did and did not receive anticoagulation were compared. Outcomes of interest included survival, portal vein thrombosis (PVT) resolution, development of chronic symptomatic portal hypertension, and major bleeding. Forty-seven patients received anticoagulation and 20 did not. The anticoagulated and non-anticoagulated groups did not differ significantly with respect to potential covariates or confounders. Anticoagulated patients had significantly higher rates of PVT resolution than non-anticoagulated patients (58% vs. 21%, p = 0.0201). This translated to lower rates of future chronic portal hypertensive symptoms among anticoagulated patients (11% vs. 47%, p = 0.0034). Anticoagulated patients had a trend toward improved survival however this improvement was not significant on multivariable analysis. There was no significant difference in rates of major bleeding between groups. Thrombophilia testing was common in this cohort however the occurrence of meaningful positive results was exceedingly low. Anticoagulation significantly improves the rate of PVT resolution, and significantly reduces the rate of chronic symptomatic portal hypertension, among patients with pylephlebitis. Treatment of pylephlebitis should incorporate the use of systemic anticoagulation whenever possible.

In vitro activity of imipenem/relebactam against Enterobacteriaceae and Pseudomonas aeruginosa isolated from intraabdominal and urinary tract infection samples: SMART Surveillance United States 2015-2017

OBJECTIVES

Antimicrobial resistance, including multidrug-resistance (MDR), is increasing, especially among Gram-negative bacilli. New agents are needed to treat infections caused by these pathogens. This report assessed the activity of imipenem/relebactam against Gram-negative bacilli from intraabdominal infections (IAIs) and urinary tract infections (UTIs) submitted to the SMART (Study for Monitoring Antimicrobial Resistance Trends) global surveillance programme in the United States from 2015 to 2017.

METHODS

Broth microdilution MICs for imipenem/relebactam and comparators were determined by a central laboratory against isolates of non-Proteeae Enterobacteriaceae (NPE) and Pseudomonas aeruginosa (P. aeruginosa). Imipenem/relebactam MICs were interpreted using United States Food and Drug Administration (FDA) breakpoints.

RESULTS

99.5% of NPE isolates collected from patients with IAIs (n=3633) and UTIs (n=3038) were susceptible to imipenem/relebactam, as were 77.9% of imipenem-nonsusceptible, 96.3% of Klebsiella pneumoniae carbapenemase (KPC)-positive, and 98.7% of MDR isolates from IAIs and UTIs combined. A total of 96.7% of IAI isolates (n=486) and 96.4% of UTI isolates (n=360) of P. aeruginosa were susceptible to imipenem/relebactam, as were 85.0% of imipenem-nonsusceptible and 87.3% of MDR isolates from IAIs and UTIs combined. Percent susceptibility to imipenem/relebactam for cefepime-, ceftazidime-, and piperacillin-tazobactam-nonsusceptible isolates was 98.3-98.8% for NPE and 87.3-90.0% for P. aeruginosa.

CONCLUSIONS

Imipenem/relebactam demonstrated potent in vitro activity against NPE and P. aeruginosa isolates from IAIs and UTIs, including against resistant subsets, and will provide important coverage for IAIs and UTIs caused by β-lactam-resistant, MDR, and KPC-positive Gram-negative bacilli.

Enhanced recovery after surgery in emergency colorectal surgery: Review of literature and current practices

Enhanced recovery after surgery (ERAS), a multidisciplinary program designed to minimize stress response to surgery and promote the recovery of organ function, has become a standard of perioperative care for elective colorectal surgery. In an elective setting, ERAS program has consistently been shown to decrease postoperative complication, reduce length of hospital stay, shorten convalescence, and lower healthcare cost. Recently, there is emerging evidence that ERAS program can be safely and effectively applied to patients with emergency colorectal conditions such as acute colonic obstruction and intraabdominal infection. This review comprehensively covers the concept and application of ERAS program for emergency colorectal surgery. The outcomes of ERAS program for this emergency surgery are summarized as follows: (1) The ERAS program was associated with a lower rate of overall complication and shorter length of hospital stay - without increased risks of readmission, reoperation and death after emergency colorectal surgery; and (2) Compliance with an ERAS program in emergency setting appeared to be lower than that in an elective basis. Moreover, scientific evidence of each ERAS item used in emergency colorectal operation is shown. Perspectives of ERAS pathway in emergency colorectal surgery are addressed. Finally, evidence-based ERAS protocol for emergency colorectal surgery is presented.

[Tratamiento ambulatorio de la diverticulitis aguda no complicada. Análisis de nuestra experiencia]

Objective

Analyze the safety and efficacy of the outpatient treatment of uncomplicated acute diverticulitis and a costs analysis.

Method

We conducted a prospective, non-randomized study between June 2014 and June 2017. We included all patients diagnosed of uncomplicated acute diverticulitis based on clinical and abdominal computed tomography scan in the Emergency Department of the University Hospital San Juan de Alicante (Spain). Outpatient treatment consisted of oral antibiotics for 7 days (amoxicillin-clavulanate or ciprofloxacin and metronidazole in patients with betalactamic allergy), liquid diet for 72 h and analgesics. Costs were evaluated according to the Law of Rates of Valencian Community.

Results

Ninety patients were included, 49 females and 41 males with a median age of 56 years. Success rate was 95.5% (n = 86) requiring hospital admission 4 patients (4.5%). Antibiotic treatment was amoxicillin-clavulanate in 82 patients (91.1%) and ciprofloxacin and metronidazole in 8 (8.9%). Cost savings per patient was approximately 1985 € comparing with hypothetically all inpatient treatment.

Conclusions

Outpatient treatment of uncomplicated acute diverticulitis can be performed successfully in most patients allowing an important cost savings.

Pathogenic bacteria in abdominal cavity drainage of patients with intraabdominal infection and their drug resistance

AIM

To identify the pathogenic bacteria in abdominal cavity drainage of patients with intraabdominal infection and to analyze their drug resistance.

METHODS

From January 2015 to November 2017, 92 patients with intraperitoneal infection were treated by celiac drainage at our hospital. The bacterial culture and drug susceptibility results of peritoneal drainage fluid were statistically analyzed, and the differences in different bacterial populations and drug resistance were analyzed. Cox regression model was used to explore the independent risk factors affecting the prognosis of patients.

RESULTS

A total of 145 bacterial strains were cultured, including 46 Gram-positive and 97 Gram-negative strains. The top five pathogens were Escherichia coli (31.72%), Klebsiellosis pneumoniae (24.14%), Staphylococcus aureus (15.86%), Enterococcus (11.72%), and Pseudomonas aeruginosa (7.59%). Staphylococcus aureus and Enterococcus were two Gram-positive strains that had high resistance rates but were highly sensitive to vancomycin. Enterococci had high resistance rates to erythromycin, chloramphenicol, and levofloxacin than Staphylococcus aureus, which had a high resistance rate to ampicillin. Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and other three kinds of G-bacteria had high resistance rates, but all of them had a high sensitivity to β-lactams/β-lactamase inhibitors, imipenem/Cistadine and amikacin; among them, extended spectrum beta lactamase (ESBL) producing strains and Pseudomonas aeruginosa had high resistance rates to ceftriaxone, ceftazidime, cefepime, and levofloxacin. Univariate Cox regression analysis showed that age, multidrug resistant organism (MDRO), nosocomial infection, ESBL positivity, and time from fever to culture were related to death in patients with intraabdominal infection. Multivariate Cox regression analysis showed that MDRO, ESBL positivity, and time from fever to culture were independent risk factors for death in patients with intraabdominal infection.

CONCLUSION

Main pathogens in peritoneal drainage fluid of patients with intraabdominal infection are Gram-negative bacteria, and the pathogens are highly resistant to commonly used antibiotics. MDRO, ESBL positivity, and time from fever to culture are independent risk factors for death from intraabdominal infection.

Intraabdominal Infections in Older Adults

Intraabdominal infections represent a diagnostic and therapeutic challenge in the elderly population. Atypical presentations, diagnostic delays, additional comorbidities, and decreased physiologic reserve contribute to high morbidity and mortality, particularly among frail patients undergoing emergency abdominal surgery. While many infections are the result of age-related inflammatory, mechanical, or obstructive processes, infectious complications of feeding tubes are also common. The pillars of treatment are source control of the infection and judicious use of antibiotics. A patient-centered approach considering the invasiveness, risk, and efficacy of a procedure for achieving the desired outcomes is recommended. Structured communication and time-limited trials help ensure goal-concordant treatment.

Graft Duodenal Perforation due to Internal Hernia after Simultaneous Pancreas-Kidney Transplantation: Report of a Case

Although complications including graft thrombosis, graft pancreatitis, and rejection have been well documented after pancreas transplantation, the occurrence of graft duodenal perforation is uncommon. In this article, we report a case of graft duodenal perforation due to internal hernia after simultaneous pancreas-kidney transplantation (SPK). A patient with type I diabetes mellitus and diabetic nephropathy had undergone SPK from a cadaveric donor. One year later, she was admitted to our hospital for severe lower abdominal pain with preshock status. She was immediately examined by abdominal computed tomography and both peripancreas graft fluid accumulation and severe dilatation of the ileum were detected. On emergency operation, two punched holes located at the graft duodenal side near the suture line and an obstruction of herniated bowel behind the graft pancreas were detected. These holes were repaired and the internal hernia was reduced. However, a control of the intraabdominal infection was very difficult despite intensive treatment with antibiotics and additional abdominal drainage. Finally, a graft pancreatectomy was unavoidably required. When complications, including symptomatic intraabdominal infection, require re-laparotomy after pancreas transplantation, the therapeutic focus should be switched from salvaging the graft to the preservation of life.