Microbial Spectrum of Intra-Abdominal Abscesses in Perforating Crohn's Disease: Results from a Prospective German Registry

Disease- and Medication-Specific Differences of the Microbial Spectrum in Perianal Fistulizing Crohn's Disease-Relevant Aspects for Antibiotic Therapy

Perianal fistulizing Crohn's Disease (CD) with abscess formation represents an aggressive phenotype in Inflammatory Bowel Disease (IBD) with increased morbidity. Treatment is multidisciplinary and includes antibiotics, but knowledge about the microbial spectrum is rare often resulting in inadequate antimicrobial therapy. In this single center retrospective study, all patients who were operated due to perianal abscess formation were retrospectively analyzed and the microbial spectrum evaluated. Patients were divided into a CD and non-CD group with further subgroup analysis. 138 patients were finally included in the analysis with 62 patients suffering from CD. Relevant differences were detected for the microbial spectrum with anaerobic bacteria being significantly more often isolated from non-CD patients. In a subgroup-analysis of CD patients only, medical therapy had a relevant effect on the microbial spectrum since Streptococcus groups and Enterobacterales were significantly more often isolated in patients treated with steroids compared to those being treated by antibodies. In conclusion, the microbial spectrum of patients suffering from CD varies significantly from non-CD patients and immunosuppressive medication has a relevant effect on isolated pathogens. Based on that, adaption of antibiotic treatment might be discussed in the future.

Microbial Spectrum and Antibiotic Resistance in Patients Suffering from Penetrating Crohn's Disease

Intraabdominal abscess formation occurs in up to 30% of patients suffering from Crohn´s disease (CD). While international guidelines recommend a step-up approach with a combination of empiric antibiotic therapy and percutaneous drainage to delay or even avoid surgery, evidence about microbial spectrum in penetrating ileitis is sparse. We retrospectively assessed outcomes of 46 patients with terminal penetrating Ileitis where microbial diagnostics have been performed and compared microbial spectrum and antibiotic resistance profile of CD patients with patients suffering from diverticulitis with intraabdominal abscess formation. In both groups, the most frequently isolated pathogen was the gram-negative bacterium E. coli belonging to the family of Enterobacterales. However, overall Enterobacterales were significantly more often verifiable in the control group than in CD patients. Furthermore, microbial analysis showed significant differences regarding isolation of anaerobic pathogens with decreased frequency in patients with CD. Subgroup analysis of CD patients to evaluate a potential influence of immunosuppressive therapy on microbial spectrum only revealed that Enterobacterales was less frequently detected in patients treated with steroids. Immunosuppressive therapy did not show any impact on all other groups of pathogens and did not change antibiotic resistance profile of CD patients. In conclusion, we were able to demonstrate that the microbial spectrum of CD patients does differ only for some pathogen species without increased rate of antibiotic resistance. However, the empiric antibiotic therapy for CD-associated intra-abdominal abscess remains challenging since different points such as local epidemiological and microbiological data, individual patient risk factors, severity of infection, and therapy algorithm including non-surgical and surgical therapy options should be considered before therapeutical decisions are made.

Therapeutic strategies in Crohn’s disease in an emergency surgical setting

Crohn’s disease (CD) remains a chronic, incurable disorder that presents unique challenges to the surgeon. Multiple factors must be considered to allow development of an appropriate treatment plan. Medical therapy often precedes or complements the surgical management. The indications for operative management of CD include acute and chronic disease complications and failed medical therapy. Elective surgery comes into play when patients are refractory to medical treatment if they have an obstructive phenotype. Toxic colitis, acute obstruction, perforation, acute abscess, or massive hemorrhage represent indications for emergency surgery. These patients are generally in critical conditions and present with intra-abdominal sepsis and a preoperative status of immunosuppression and malnutrition that exposes them to a higher risk of complications and mortality. A multidisciplinary team including surgeons, gastroenterologists, radiologists, nutritional support services, and enterostomal therapists are required for optimal patient care and decision making. Management of each emergency should be individualized based on patient age, disease type and duration, and patient goals of care. Moreover, the recurrent nature of disease mandates that we continue searching for innovative medical therapies and operative techniques that reduce the need to repeat surgical operations. In this review, we aimed to discuss the acute complications of CD and their treatment.

Surgical site infections caused by multi-drug resistant organisms: a case-control study in general surgery

Multi-drug resistant organisms (MDR-Os) are emerging as a significant cause of surgical site infections (SSI), but clinical outcomes and risk factors associated to MDR-Os-SSI have been poorly investigated in general surgery. Aims were to investigate risk factors, clinical outcomes and costs of care of multi-drug resistant organisms (MDR-Os-SSI) in general surgery. From January 2018 to December 2019, all the consecutive, unselected patients affected by MDR-O SSI were prospectively evaluated. In the same period, patients with non-MDR-O SSI and without SSI, matched for clinical and surgical data were used as control groups. Risk factors for infection, clinical outcome, and costs of care were compared by univariate and multivariate analysis. Among 3494 patients operated on during the study period, 47 presented an MDR-O SSI. Two control groups of 47 patients with non-MDR-O SSI and without SSI were identified. MDR-Os SSI were caused by poly-microbial etiology, meanly related to Gram negative Enterobacteriales. MDR-Os-SSI were related to major postoperative complications. At univariate analysis, iterative surgery, open abdomen, intensive care, hospital stay, and use of aggressive and expensive therapies were associated to MDR-Os-SSI. At multivariate analysis, only iterative surgery and the need of total parenteral and immune-nutrition were significantly associated to MDR-Os-SSI. The extra-cost of MDR-Os-SSI treatment was 150% in comparison to uncomplicated patients. MDR-Os SSI seems to be associated with major postoperative complications and reoperative surgery, they are demanding in terms of clinical workload and costs of care, they are rare but increasing, and difficult to prevent with current strategies.

Does Anti-TNF-α Therapy Affect the Bacteriological Profile of Specimens Collected from Perianal Lesions? A Retrospective Analysis in Patients with Crohn's Disease

Anal abscesses and fistulas are potential complications of Crohn’s disease (CD). Chronic immunosuppression, loose stools, and poor wound healing in this population present challenges to the management of perianal diseases. The purpose of the study was to determine the predominant bacterial species found in specimens from perianal lesions causing anal abscess and/or fistula drainage in hospitalized patients, and to compare the number and type of microorganisms isolated from samples taken from patients undergoing biological therapy or traditionally treated. The outcomes of studies of patients treated for anal abscesses or fistulas from 2017 to 2019 were evaluated. Data obtained from medical records included culture and antibiotic sensitivity results of swabs from perianal lesions of isolated microorganisms. A total of 373 swabs were collected from perianal lesions during the analysis period, including 51 (49 positive samples) from patients with CD. The predominant pathogen was Escherichia coli (55%, p < 0.001), the second most common microorganism was Staphylococcus aureus (14.3%, p < 0.001). In vitro susceptibility testing showed E. coli, ESBL (strain with Extended Spectrum Beta-Lactamase) in five cases, S. aureus, MRSA (methicillin-resistant S. aureus -resistant to all beta-lactam antibiotics: penicillins with inhibitors, cephalosporins, monobactams, carbapenems, except for ceftaroline) in one sample. Biologic therapy does not affect the type of microorganisms isolated from perianal abscesses in patients with CD.

Clinical characteristics and outcome of patients with enterococcal liver abscess

Epidemiology of bacteria isolated from pyogenic liver abscesses change, and an increase in enterococci has been reported in European hospitals. The aim of this study was to investigate the clinical characteristics and outcome of enterococcal PLA. We performed a retrospective analysis of patients with microbiologically confirmed PLA at three German university centers. Indicators of enterococcal PLA were determined using binary logistic regression, and survival analysis was performed using Kaplan-Meier statistics and Cox regression analysis. Enterococci were isolated in 51/133 (38%) patients with PLA. Patients with enterococcal PLA had smaller abscess diameter (4.8 vs. 6.7 cm, p = 0.03) than patients with non-enterococcal PLA, but had more frequent polymicrobial culture results. In univariate logistic regression analysis, alcohol abuse (OR 3.94, 95% CI 1.24-12.49, p = 0.02), hepatobiliary malignancies (OR 3.90, 95% CI 1.86-8.18, p < 0.001) and cirrhosis (OR 6.36, 95% CI 1.27-31.96, p = 0.02) were associated with enterococcal PLA. Patients with enterococcal PLA had a higher mortality than patients with non-enterococcal PLA (hazard ratio 2.92; 95% confidence interval 1.09-7.80; p = 0.03), which remained elevated even after excluding patients with hepatobiliary malignancies, cirrhosis, and transplant recipients in a sensitivity analysis. The increased mortality was associated with non-fecal enterococci but not in patients with Enterococcus faecalis. In this retrospective, multicenter study, enterococcal PLA was common and indicated an increased risk of mortality, underscoring the need for close clinical monitoring and appropriate treatment protocols in these patients.

Dynamic immunoglobulin responses to gut bacteria during inflammatory bowel disease

Aberrant immune responses against gut microbiota are thought to be key drivers of inflammatory bowel disease (IBD) pathogenesis. However, the extent and targets of immunoglobulin (Ig) A versus IgG responses to gut bacteria in IBD and its association with IBD severity is not well understood. Here, we address this by analyzing fecal samples from Crohn's disease (CD), ulcerative colitis (UC), and Non-IBD patients by flow cytometry for the frequency of bacteria that were endogenously bound with IgA and/or IgG. Assessment of IBD patients from two geographically distinct cohorts revealed increased percentages of IgA- and IgG-bound fecal bacteria compared to non-IBD controls. Notably, the two major subsets of IBD showed distinct patterns of Ig-bound bacteria, with CD activity associated with increases in both IgA and IgG-bound bacteria, whereas UC activity correlated only with increases in IgG-bound bacteria. Analysis of the flow sorted Ig-bound bacterial repertoire by 16S rDNA sequencing revealed taxa that were Ig-bound specifically in IBD. Notably, this included bacteria that are also thought to reside in the oral pharynx, including Gemella, Peptostreptococcus, and Streptococcus species. These data show that the pattern of IgA and IgG binding to fecal bacteria is distinct in UC and CD. In addition, the frequency of Ig-bound fecal bacteria may have potential as a non-invasive biomarker for disease activity. Finally, our results support the hypothesis that immune responses to oral pharyngeal bacteria may play an important role in the pathogenesis of IBD.

Inpatient Management of Inflammatory Bowel Disease-Related Complications

Despite advances in therapeutic options, a sizeable proportion of patients with inflammatory bowel disease require hospitalization or surgery during their lifetime. While current treatment guidelines for the management of ulcerative colitis and Crohn's disease cover the spectrum of disease severity and behavior, management of acute complications of inflammatory bowel disease can present unique challenges that are not always addressed in these guidelines. In this review, the authors provide a comprehensive summary of the existing literature focused on management of patients hospitalized with complications of inflammatory bowel disease. Proposed management algorithms are provided to guide clinicians through common scenarios to determine the most appropriate interventions - escalation of medical therapies, non-surgical therapeutic interventions (drainage of intra-abdominal abscess or endoscopic balloon dilation) or surgery. Prevention of complications is proposed through a multi-disciplinary approach that involves surgeons, dieticians, radiologists, pathologists and infectious disease consultants.

Risk of bacteremia in hospitalised patients with inflammatory bowel disease: a 9-year cohort study

BACKGROUND

Patients with inflammatory bowel disease might be at increased risk of invasive bacterial infections.

OBJECTIVES

The objective of this study was to identify the rate of bacteremia in hospitalised patients with inflammatory bowel disease and risk factors.

METHODS

An observational cohort of hospitalised patients with inflammatory bowel disease, aged 16-80 years, from 2008 to 2017 in a large tertiary hospital. Patients with Charlson comorbidity index of 2 or greater were excluded. Patients with one or more positive blood culture were reviewed. Logistic regression was used to evaluate risk factors for bacteremia.

RESULTS

Of 5522 admitted patients, only 1.3% had bacteremia (73/5522) (39, Crohn's disease; 25, ulcerative colitis; nine, unclassified inflammatory bowel disease). The most common pathogen was Escherichia coli (19/73 patients). The mortality rate at 30 days of patients with bacteremia was 13.7% (10/73). Longer hospitalisations (mean length of stay (21.6 ± 31.0 vs. 6.4 ± 16.0 days; P < 0.0001) and older age (mean age 47.5 ± 18.0 vs. 40.2 ± 15.4 years, P < 0.0001)) were associated with an increased risk of bacteremia. In multivariate analysis, treatment with either anti-tumour necrosis factor α, purine analogues, steroids or amino salicylates was not associated with an increased risk of bacteremia. Risk was greatest among patients aged 65 years or older (relative risk 2.84, 95% confidence interval 1.6-4.8; P = 0.0001) relative to those under 65 years.

CONCLUSION

Age over 65 years, but not inflammatory bowel disease-related medications, is associated with an increased risk of bacteremia in hospitalised patients with inflammatory bowel disease.

Proteus spp. as Putative Gastrointestinal Pathogens

Proteus species, members of the Enterobacteriaceae family, are usually considered commensals in the gut and are most commonly recognized clinically as a cause of urinary tract infections. However, the recent identification of Proteus spp. as potential pathogens in Crohn's disease recurrence after intestinal resection serves as a stimulus to examine their potential role as gut pathogens. Proteus species possess many virulence factors potentially relevant to gastrointestinal pathogenicity, including motility; adherence; the production of urease, hemolysins, and IgA proteases; and the ability to acquire antibiotic resistance. Gastrointestinal conditions that have been linked to Proteus include gastroenteritis (spontaneous and foodborne), nosocomial infections, appendicitis, colonization of devices such as nasogastric tubes, and Crohn's disease. The association of Proteus species with Crohn's disease was particularly strong. Proteus species are low-abundance commensals of the human gut that harbor significant pathogenic potential; further investigation is needed.