Management of Intra-abdominal Infections due to Carbapenemase-Producing Organisms

Risk Factors for Intra-Abdominal Infections Caused by Carbapenemase-Producing Enterobacteriaceae in a Surgical Setting

Background: The aim of this study was to identify risk factors for acquisition of intra-abdominal infections (IAI) caused by carbapenemase-producing Enterobacteriaceae (CPE) in surgical patients. Methods: A matched case-control study was performed. We included all cases with CPE-related IAI acquired during admission to a general surgery department from January 2013 to December 2018, and they were matched with control subjects with IAI caused by non-resistant bacteria (ratio 1:3). Independent risk factors were obtained by logistic regression. Results: Forty patients with IAI-CPE were matched with 120 control subjects. Independent risk factors for acquisition of IAI-CPE were previous hospitalization (odds ratio [OR] 2.56; 95% confidence interval [CI] l 1.01-6.49; p = 0.047), digestive endoscopy (OR 4.11; 95% CI 1.40-12.07; p = 0.010), carbapenem therapy (OR 9.54; 95% CI 3.33-27.30; p < 0.001), and aminoglycoside use (OR 45.41; 95% CI 7.90-261.06; p < 0.001). Conclusions: Four clinical factors can identify patients at high-risk of IAI-CPE.

Intra-Abdominal Infections by Carbapenemase-Producing Enterobacteriaceae in a Surgical Unit: Counting Mortality, Stay, and Costs

Background: Carbapenemase-producing Enterobacteriaceae (CPE)-related infections are a problem in public health at present, including intra-abdominal infections (IAI) and surgical populations. The aim of this study was to determine mortality and related risk factors, length of stay (LOS,) and costs for CPE-IAI in surgical patients. Patients and Methods: Review of CPE-related IAI acquired during admission in a general surgery department from January 2013 to December 2018. A mortality analysis was performed specifically in patients with CPE-IAI, and a global analysis of IAI including patients with CPE-IAI (cases) and matched patients with IAI by non-resistant bacteria (controls). Results: Forty patients with CPE-IAI were included, OXA-48-producing Klebsiella pneumoniae was present in 85%. Global mortality rate at 30 days for CPE-IAI was 17.5%; mortality-related factors were: solid tumor (p = 0.009), metastatic disease (p = 0.005), immunodeficiency (p = 0.039), blood transfusion (p = 0.009), and septic shock (p = 0.011). Predictors related to mortality for IAI in the global analysis included age (p = 0.046), Charlson index (p = 0.036), CPE isolation (p = 0.003), and septic shock (p < 0.001). Median global LOS was 43 days (IQR 27-64) in patients with CPE-IAI, and 27 days (IQR 18-35) in controls (p < 0.001). Median global cost of admission was $31,671 (IQR 14,006-55,745) for patients with CPE-IAI and $20,306 (IQR 11,974-27,947) for controls (p = 0.064). The most relevant locations of underlying disease for CPE-IAI were: colorectal (32.5%) with 57-day LOS (IQR 34-65) and cost of $42,877 (IQR 18,780-92,607), and pancreas (25%) with 60-day LOS (IQR 32-99) and cost of $56,371 (IQR 32,590-113,979). Conclusion: Carbapenemase-producing Enterobacteriaceae-related IAI is associated with substantial mortality, LOS, and costs. Factors related to CPE-IAI mortality are solid tumor, metastatic disease, immunodeficiency, blood transfusion, and septic shock. Carbapenemase-producing Enterobacteriaceae isolation in IAI implies higher risk of mortality.

Epidemiology, Treatment, and Prevention of Nosocomial Bacterial Pneumonia

Septicaemia likely results in high case-fatality rates in the present multidrug-resistant (MDR) era. Amongst them are hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), two frequent fatal septicaemic entities amongst hospitalised patients. We reviewed the PubMed database to identify the common organisms implicated in HAP/VAP, to explore the respective risk factors, and to find the appropriate antibiotic choice. Apart from methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa, extended-spectrum β-lactamase-producing Enterobacteriaceae spp., MDR or extensively drug-resistant (XDR)-Acinetobacter baumannii complex spp., followed by Stenotrophomonas maltophilia, Chryseobacterium indologenes, and Elizabethkingia meningoseptica are ranked as the top Gram-negative bacteria (GNB) implicated in HAP/VAP. Carbapenem-resistant Enterobacteriaceae notably emerged as an important concern in HAP/VAP. The above-mentioned pathogens have respective risk factors involved in their acquisition. In the present XDR era, tigecycline, colistin, and ceftazidime-avibactam are antibiotics effective against the Klebsiella pneumoniae carbapenemase and oxacillinase producers amongst the Enterobacteriaceae isolates implicated in HAP/VAP. Antibiotic combination regimens are recommended in the treatment of MDR/XDR-P. aeruginosa or A. baumannii complex isolates. Some special patient populations need prolonged courses (>7-day) and/or a combination regimen of antibiotic therapy. Implementation of an antibiotic stewardship policy and the measures recommended by the United States (US) Institute for Healthcare were shown to decrease the incidence rates of HAP/VAP substantially.

Bactibilia in women affected with diseases of the biliary tract and pancreas. A STROBE guidelines-adherent cross-sectional study in Southern Italy

PURPOSE

Bile is a hepatobiliary lipid-rich sterile solution, and its colonization by microorganisms defines the condition of bactibilia. In this study, we aimed to assess the bile microbiological flora and its potential link with comorbidity in women.

METHODOLOGY

We performed a microbiologic investigation on 53 female patients with biliopancreatic diseases who granted consent, and we analysed the data using a MATLAB platform.

RESULTS

We found that the most frequent disease associated with bactibilia was pancreas head carcinoma (PHC) (P=0.0015), while the least frequent disease was gall bladder carcinoma (GBC) (P=0.0002). The most common microorganisms were Pseudomonas spp. (P<0.0001) and Escherichia coli (P<0.0001). In particular Pseudomonas spp. and E. coli were negatively correlated to PHC presence and positively correlated to CCA by both univariate and multivariate analysis.

CONCLUSIONS

Gram-negative bacteria have been linked to a tumour-associated inflammatory status. In the last 30 years, the analysis of mortality rate in Italy for PHC and GBC shows an increasing and a decreasing trend, respectively. Although this study targeted only 53 patients and does not reflect the frequency of diagnosis in a Southern Italian population, the decrease in GBC may raise the suggestion ofnon-adherence to a Mediterranean diet that may have become more prevalent in Southern Italy since the 1990s.

Bactibilia in diseases of the biliary tract and pancreatic gland in patients older than 80 years: a STROBE-retrospective cohort study in a teaching hospital in Italy

Bile is a lipid-rich sterile solution produced in the liver that can be infected resulting in bactibilia. A higher incidence of postoperative infectious complications has been seen in patients with bactibilia. Recently, gram-negative bacteria have been linked to a tumor-associated inflammatory status. This study is a retrospective cohort study of 39 patients, who are over 80 years of age only (53.85% males and 46.15% females), hospitalized with diseases of the biliopancreatic system in one teaching hospital in Italy from January 2011 to December 2012 with a follow-up of 5 years. The most common biliary diseases after surgery were pancreatic head cancer (p < 0.0001) and gallbladder cancer (p = 0.0051), while the most common bacteria in the bile were E. coli (p = 0.0180) and Pseudomonas spp. (p < 0.0001). Uni- and multivariate linear correlation analysis revealed that patients with pancreatic head cancer had low survival times compared to patients with other diseases. Moreover, the bacterium type was a positive predictor of survival time compared to other variables. Our data confirm E. coli as a pathogen in patients with gallbladder and pancreatic cancer. Although the influence of bactibilia in developing surgical complications is limited, we consider that its composition is crucial to properly address the antibiotic treatment in biliary tract infections, especially in the elderly.

Shifting trends in bacteriology and antimicrobial resistance among gastrointestinal fistula patients in China: an eight-year review in a tertiary-care hospital

BACKGROUND

The purpose of this study was to determine the shifting trends in bacteriology and antimicrobial resistance of infectious specimens isolated from gastrointestinal (GI) fistula patients over eight years in China.

METHODS

We retrospectively reviewed the microbial records of intra-abdominal specimens at a teaching hospital from 2008 to 2015. Study period was divided into the first half (2008-2011) and the second half (2012-2015). All isolates underwent antibiotic susceptibility testing by the micro dilution method.

RESULTS

A total of 874 intra-abdominal isolates were consecutively collected from 502 GI fistula patients (mean age, 46.5 years, 71.1% male) during the study period. Patients in the second study period (2012-2015) were older (>65 years) and more likely to have experienced cancer. Over the entire study period, most infections were caused by E. coli (24.2%) and K. pneumonia (14.1%). There was a significant decrease in the proportion E. coli isolates that were extended- spectrum beta-lactamase (ESBL)-positive (P = 0.026). The proportion of E. coli resistant to imipenem increased from 14.3% in 2008-2011 to 25.9% in 2012-2015 (P = 0.037). Imipenem resistance prevalence was higher in ESBL-negative bacteria than ESBL-positive bacteria for both E. coli and K. pneumonia (P < 0.001). In Enterococcus, significant increase in resistance to ampicillin (P = 0.01) and moxifloxacin (P = 0.02) over time were observed. In Staphylococcus and fungi, rates of antibiotic resistance did not significantly change over the study period.

CONCLUSIONS

Gram-negative bacteria predominated as causative agents of intra-abdominal infections in GI fistula patients, and there was an increase in levels of resistance to certain antibiotics, particularly carbapenems. Infection control and source control are important tools available to surgeons to prevent the emergence of antibiotic-resistant pathogens.

Intra-abdominal Candida spp infection in acute abdomen in a quality assurance (QA)-certified academic setting

AIMS

To evaluate the contribution of light microscopy to detecting Candida spp infection in patients with complicated intra-abdominal infections (IAIs) admitted for acute abdomen to a quality assurance (QA)-certified surgical emergency ward.

METHODS

We conducted a retrospective study (2008-2012) of 809 abdominal intraoperative or biopsy tissue specimens obtained from patients admitted with acute abdomen and microbiological samples positive for Candida spp. Demographic data, mortality, comorbidities, specimen type, microscopy results, special histological staining performed, antimicrobial therapy were collected and analysed. Any comments at the multidisciplinary team meeting was recorded in minutes of and approved.

RESULTS

Sixty-six patients with complicated IAIs due to Candida spp were identified (39 male, 27 female, mean±SD age 75±20 years). Candida albicans was isolated in 35 cases and Candida non-albicans spp in 31 cases. Candida spp were isolated from blood in 50% of all selected microbiological specimens. Patients were stratified according to Candida spp (albicans vs non-albicans), underlying cancer disease and no previous antimicrobial administration, and a positive correlation with C. albicans isolation was found (p=0.009 and p=0.048, respectively). Out of 41 cases with microscopic evaluation, we identified yeast forms, pseudohyphae or both, indicative of Candida spp, in 23. Identification of Candida spp in histological specimens was higher in C. albicans cases than in C. non-albicans cases (73% vs 37.5%). Microscopy allowed prompt treatment of all patients.

CONCLUSIONS

Light microscopy still has great diagnostic significance, being a solid QA step. It provides rapid information and clues in patients who may harbour impaired defence mechanisms, concurrent chronic conditions and/or cancer.

Use of Cepheid Xpert Carba-R® for Rapid Detection of Carbapenemase-Producing Bacteria in Abdominal Septic Patients Admitted to Intensive Care Unit

Early institution of effective antibiotic therapy and source control are pivotal to improve survival of abdominal septic patients. Xpert® Carba-R is a real time polymerase chain reaction assay for rapid detection and differentiation of five genes (blaKPC, blaVIM, blaOXA-48, blaIMP-1, blaNDM) responsible for carbapenem resistance. We performed an observational study investigating the clinical usefulness and applicability of Xpert® Carba-R to detect carbapenem resistance in abdominal septic patients admitted to intensive care unit. We compared the results of Xpert® Carba-R with standard microbiological culture. We collected a set of two rectal/stomia swabs and two swabs from abdominal drainage fluid for each patient. We included 20 patients for a total of 45 comparisons between the two methods. In our clinical setting, the overall performance of Xpert® Carba-R for detection of carbapenem resistance in the presence of genes detectable and non-detectable by the method was: sensitivity 50% (95% CI 24.6-75.3); specificity 93.1% (95% CI 77.2-99.1); positive predictive value (PPV) 80% (95% CI 44.4-97.5); negative predictive value (NPV) 77.1% (95% CI 56.9-89.6). The inter-rater agreement was 0.47 (SE 0.14; 95% CI 0.20-0.74). When considering the only 5 mechanisms of resistance detected by both methods, the overall diagnostic performance was: sensitivity 100% (95% CI 69.1-100), specificity 94.2 (95% CI 80.8-99.3), PPV 83.3 (95% CI 59.6-97.9) and NPV 100% (95% CI 89.4-100). The inter-rater agreement was 0.88 (SE 0.08; 95% CI 0.71-1). Xpert® Carba-R may be considered an additional diagnostic tool for early diagnosis of carbapenem resistance in abdominal septic patients. Clinicians should be aware of their epidemiology before its introduction in the diagnostic protocol of their intensive care units.