Extraintestinal Clostridioides difficile Infections: Epidemiology in a University Hospital in Hungary and Review of the Literature

Early diagnosis of monomicrobial Clostridioides difficile bacteremia in a patient without colitis

Bacteremia is a rare finding among Clostridioides difficile infections. We describe a case of a 67-year-old man with resected colorectal cancer with colostomy who presented with small bowel obstruction and was admitted for lysis of adhesions. On day 8 of admission, he developed leukocytosis and raised inflammatory markers with isolation of Gram-positive bacilli in several blood cultures, which was presumptively identified through blood culture pelleting and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) as C. difficile. The diagnosis was confirmed with conventional culture and reference lab identification and the patient demonstrated clinical response with parenteral then oral vancomycin that briefly worsened when therapy was switched to parenteral metronidazole and then improved once oral vancomycin was resumed. Our case was notable in that the combination of pelleting and MALDI-TOF offered early diagnosis in this patient whose positive blood cultures were suspicious for contamination and in whom there was an absence of diarrheal illness or features of colitis on abdominal imaging. Early diagnosis is critical for the timely initiation of therapy, implementation of infection prevention and control measures and in selection of appropriate therapy for antimicrobial stewardship.

Polymicrobial Clostridioides difficile lung empyema

Clostridioides (Clostridium) difficile is a well-known cause of enteritis and antibiotic-associated diarrhea. Extraintestinal C. difficile infection is uncommon, with most extraintestinal infections involving the intra-abdominal cavity and anatomic structures adjacent to the colon. Empyema secondary to C. difficile is especially rare, with only a handful of cases reported in the medical literature. A standard antibiotic treatment regimen for C. difficile empyema does not currently exist, and data chronicling successful treatment is limited. We present the case of an 80-year-old woman with a polymicrobial C. difficile empyema who was successfully treated with multiple chest tube insertions and intravenous vancomycin.

Non-C. difficile Clostridioides Bacteremia in Intensive Care Patients, France

Article Summary: This multicenter study focusing on critically ill patients showed a strong relationship between hemolysis and mortality.

Usually responsible for soft tissue infections, Clostridioides species can also cause bacteremia, life-threatening infections often requiring intensive care unit (ICU) admission. We conducted a multicenter retrospective study to investigate Clostridioides bacteremia in ICUs to describe the clinical and biologic characteristics and outcomes in critically ill patients. We identified 135 patients with Clostridioides bacteremia, which occurred almost exclusively (96%) in patients with underlying conditions. Septic shock and digestive symptoms were the hallmarks of Clostridioides bacteremia in the ICU. We identified 16 different species of Clostridioides, among which C. perfringens accounted for 31% of cases. Despite the high sensitivity of Clostridioides to common antimicrobial drugs, mortality rates were high: 52% for ICU patients and 71% overall at 3 months. In multivariate analysis, the most important factor associated with increased risk for death was the presence of hemolysis. Clostridioides bacteremia often leads to multiple organ failures, which have high mortality rates.

Large Clostridial Toxins: Mechanisms and Roles in Disease

Large clostridial toxins (LCTs) are a family of bacterial exotoxins that infiltrate and destroy target cells. Members of the LCT family include Clostridioides difficile toxins TcdA and TcdB, Paeniclostridium sordellii toxins TcsL and TcsH, Clostridium novyi toxin TcnA, and Clostridium perfringens toxin TpeL. Since the 19th century, LCT-secreting bacteria have been isolated from the blood, organs, and wounds of diseased individuals, and LCTs have been implicated as the primary virulence factors in a variety of infections, including C. difficile infection and some cases of wound-associated gas gangrene. Clostridia express and secrete LCTs in response to various physiological signals. LCTs invade host cells by binding specific cell surface receptors, ultimately leading to internalization into acidified vesicles. Acidic pH promotes conformational changes within LCTs, which culminates in translocation of the N-terminal glycosyltransferase and cysteine protease domain across the endosomal membrane and into the cytosol, leading first to cytopathic effects and later to cytotoxic effects. The focus of this review is on the role of LCTs in infection and disease, the mechanism of LCT intoxication, with emphasis on recent structural work and toxin subtyping analysis, and the genomic discovery and characterization of LCT homologues. We provide a comprehensive review of these topics and offer our perspective on emerging questions and future research directions for this enigmatic family of toxins.

Effect of the Short-Term Use of Fluoroquinolone and β-Lactam Antibiotics on Mouse Gut Microbiota

BACKGROUND

Antibiotics play an important role in the treatment of infectious diseases. However, the overuse of antibiotics increases the spread of drug-resistant bacteria and causes dysbiosis of the intestinal microbiota. Few studies have addressed the longitudinal effects of antibiotics on the microbiome and host immunity.

MATERIALS AND METHODS

In this study, the short-term effect of fluoroquinolone (levofloxacin) and β-lactam antibiotics (meropenem, cefoperazone/sulbactam, and aztreonam) on the gut microbiota of mice was evaluated by 16S rRNA gene sequencing. The susceptibility of Bifidobacterium longum, Lactobacillus lactis, Enterococcus faecium, and Clostridium butyricum to these antimicrobial agents was assessed using the disc diffusion method.

RESULTS

Our results showed that 4-day antibiotic exposure significantly reduced the alpha and beta diversity of gut bacteria and increased serum inflammatory cytokines, and these changes persisted long after antibiotic withdrawal and did not return to pre-treatment levels. Nonetheless, the bacterial community composition tended to return to pre-treatment levels after discontinuing treatment. The tested probiotic strains were resistant to aztreonam but were sensitive to meropenem and cefoperazone/sulbactam.

CONCLUSION

Short-term antibiotic treatment led to significant changes in the intestinal flora with a tendency to recover. The antibiotics had different effects on the intestinal microbial community and probiotic strains. This study provides guidance for the concomitant use of probiotics and antibiotics, and the results emphasize the importance of using broad-spectrum antibiotics responsibly to prevent the long-term disruption of the native microbiota.

Clinical characteristics and prognostic factors of extraintestinal infection caused by Clostridioides difficile: analysis of 60 consecutive cases

Data regarding extraintestinal Clostridioides difficile infections (ECDIs) remain scarce and anecdotal. We conducted a retrospective cohort study to investigate characteristics and prognostic factors in patients with ECDI. From January 1997 through December 2018, 60 patients were enrolled and divided into three groups as follows: group A (gastrointestinal [GI] disruption caused by malignancy, n = 13); group B (GI disruption from causes other than malignancy, n = 25); group C (no GI disruption, n = 22). GI disruption was defined as compromised integrity of the GI tract caused by abdominal surgery, perforation, malignancy, enterocolitis, or bleeding. The incidence of ECDI was 2.53 per 100,000 admissions. The most common specimens yielded C. difficile were blood (36.7%), peritoneal fluid (20.0%), and abscesses (16.7%). Six patients (10.0%) had confirmed C. difficile enterocolitis, and 36 patients (60.0%) had a polymicrobial infection. C. difficile bacteremia was significantly more common in group A patients than those in groups B or C (53.8% vs. 48.0% vs. 13.6%, p = 0.02), as was the 30-day mortality rate (69.2% vs. 12.0% vs. 18.2%, respectively; p < 0.001). In multivariate analysis, group A (adjusted odds ratio [aOR], 17.32; 95% confidence interval [CI], 2.96-101.21; p = 0.002) and an age of > 65 years (aOR, 7.09; 95% CI, 1.31-38.45; p = 0.02) were independent risk factors for 30-day mortality. ECDI was uncommonly associated with C. difficile enterocolitis. Two factors, GI disruption caused by malignancy, and old age, were associated with significantly poorer short-term outcomes.

Relevance of anaerobic bacteremia in adult patients: A never-ending story?

Obligate anaerobic bacteria are considered important constituents of the microbiota of humans; in addition, they are also important etiological agents in some focal or invasive infections and bacteremia with a high level of mortality. Conflicting data have accumulated over the last decades regarding the extent in which these pathogens play an intrinsic role in bloodstream infections. Clinical characteristics of anaerobic bloodstream infections do not differ from bacteremia caused by other pathogens, but due to their longer generation time and rigorous growth requirements, it usually takes longer to establish the etiological diagnosis. The introduction of matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) has represented a technological revolution in microbiological diagnostics, which has allowed for the fast, accurate and reliable identification of anaerobic bacteria at a low sample cost. The purpose of this review article is to summarize the currently available literature data on the prevalence of anaerobic bacteremia in adults for physicians and clinical microbiologists and to shed some light on the complexity of this topic nowadays.

Long-Term Antibiotic Prophylaxis in Urology and High Incidence of Clostridioides difficile Infections in Surgical Adult Patients

Clostridioides difficile infections are the main cause of antibiotic-related diarrhea. Most of them come in the form of healthcare-associated Clostridioides difficile infections (HA-CDI). The aim of the study was to analyze HA-CDI epidemiology and the relationship between antibiotic consumption and CDI epidemiology at St Luke’s Provincial Hospital in Tarnow, Poland. In 2012–2018, surveillance of CDI was carried out in adult surgical wards at St Luke’s Provincial Hospital. The data were collected in accordance with the methodology of the Healthcare-Associated Infections Surveillance Network (HAI-Net), European Centre for Disease Prevention and Control (ECDC), and the ATC/DDD system (Anatomical Therapeutic Chemical Classification System) of the World Health Organization. In total, in the study period, 51 cases of CDI involved CA-CDI (24.5%) and 147 were HA-CDIs (75.5%). The most CA-CDIs were found in the general surgery (32.6%) and urology (17.0%) wards. CA-CDI incidence was 0.7/1000 patients and for HA-CDI it was 2/1000 patients (4.4/10,000 patientdays (pds)). The highest HA-CDI incidence was in the neurosurgical departments (18/10,000 pds) and oncological surgery (8.4/10,000) pds. There was a significant positive correlation between CA-CDI and HA-CDI (correlation of 0.943, p < 0.001) and between the number of patients hospitalized and HA-CDI (correlation of 0.865, p = 0.012). The total antibiotic consumption amounted to 0.7 DDD/10,000 pds; it was the highest in the urology ward (0.84/10,000 pds) and 49.5% of the antibiotics were fluoroquinolones (0.41/10,000 pds). On the basis of regression coefficients, a positive correlation was demonstrated between the use of fluoroquinolones and the HA-CDI incidence rate. Both a high percentage of CDI cases and a high intake of antibiotics were recorded in the urology department. About half of all antibiotics were fluoroquinolones.