Impact of Reduced Fluoroquinolone Use on Clostridioides difficile Infections Resulting From the Fluoroquinolone-Resistant Ribotype 027 Strain in a Veterans Affairs Medical Center

Epidemiology of Clostridioides difficile infection at one hospital 10 years after an outbreak of the epidemic C. difficile strain BI/027: changing strain prevalence, antimicrobial susceptibilities, and patient antibiotic exposures

In contrast to the epidemiology 10 years earlier at our hospital when the epidemic restriction endonuclease analysis (REA) group strain BI accounted for 72% of Clostridioides difficile isolates recovered from first-episode C. difficile infection (CDI) cases, BI represented 19% of first-episode CDI isolates in 2013-2015. Two additional REA group strains accounted for 31% of isolates (Y, 16%; DH, 12%). High-level resistance to fluoroquinolones and azithromycin was more common among BI isolates than among DH, Y, and non-BI/DH/Y isolates. Multivariable analysis revealed that BI cases were 2.47 times more likely to be associated with fluoroquinolone exposure compared to non-BI cases (95% confidence interval [CI]: 1.12-5.46). In addition, the odds of developing a CDI after third- or fourth-generation cephalosporin exposure was 2.83 times for DH cases than for non-DH cases (95% CI: 1.06-7.54). Fluoroquinolone use in the hospital decreased from 2005 to 2015 from a peak of 113 to a low of 56 antimicrobial days/1,000 patient days. In contrast, cephalosporin use increased from 42 to 81 antimicrobial days/1,000 patient days. These changes correlated with a decrease in geometric mean MIC for ciprofloxacin (61.03 to 42.65 mg/L, P = 0.02) and an increase in geometric mean MIC for ceftriaxone (40.87 to 86.14 mg/L, P < 0.01) among BI isolates. The BI strain remained resistant to fluoroquinolones, but an overall decrease in fluoroquinolone use and increase in cephalosporin use were associated with a decrease in the prevalence of BI, an increased diversity of C. difficile strain types, and the emergence of strains DH and Y.

Usefulness of Capillary Gel Electrophoresis-Based PCR for Detection of Clostridioides difficile Strains with Hypervirulent Ribotypes

Clostridioides difficile is a complex of anaerobic bacteria responsible for the epidemics of post-antibiotic diarrhea as one of the examples of CDI (Clostridioides difficile infection). As many as 70% of cases concern hospitalized patients, particularly those in intensive care units. Ribotyping is one of the most common methods for differentiating bacterial strains. The purpose of this work was to show the effectiveness of the gel electrophoresis-based PCR ribotyping method and the Webribo database for typing C. difficile isolates, including the hypervirulent 027 ribotype. DNA samples extracted from 69 C. difficile strains with previously marked genotypes were included in this study. PCR was performed using 16S-23S primers, and capillary gel electrophoresis was performed on the Applied Biosystem 3130xl Genetic Analyzer. The Webribo database was applied for ribotype assignment. Out of 69 samples, 48 belonged to already known ribotypes, 13 represented new ribotypes and 8 was indicated as similar to the existing ones, having some differences. Capillary gel electrophoresis-based PCR is an effective method for the differentiation of C. difficile ribotypes and can be recognized as a very useful tool in epidemiological studies, while the Webribo database is a useful and an accessible database for a quick analysis of C. difficile ribotypes.

Incidence and Risk Factors for Clostridioides difficile Infections in Non-COVID and COVID-19 Patients: Experience from a Tertiary Care Hospital

(1) Background: The aim of this study was to assess the incidence and the risk factors for healthcare-associated Clostridioides difficile infection (HA-CDI) in patients with COVID-19 and without this infection. (2) Methods: A single-center, prospective observational study was conducted at the University Clinical Hospital Center in Belgrade, Serbia, from January 2019 to December 2021. The entire hospital was a COVID-dedicated hospital for 12 months during the study period. The incidence density rates and risk factors for HA-CDI in patients with and without COVID-19 are presented. (3) Results: The incidence rates of HA-CDIs were three times higher in patients with COVID-19. The HA-CDI-COVID-patients were younger (69.9 ± 12.6 vs. 72.5 ± 11.6; p = 0.017), admitted from another hospital (20.5% vs. 2.9; p < 0.001), had antimicrobial therapy before CDI (99.1% vs. 91.3%, p < 0.001), received two or more antibiotics (p = 0.030) during a longer period (p = 0.035), received proton pump inhibitors (95.9% vs. 50.0%, p < 0.001) during a longer period (p = 0.012) and steroids (32.8% vs. 20.4%, p < 0.001). During the last month before their current hospitalization, a higher percentage of patients without COVID-19 disease were hospitalized in our hospital (p < 0.001). Independent predictors for HA-CDIs in patients with COVID-19 were admission from another hospital (p = 0.003), the length of antibiotic administration (0.020), and the use of steroids in therapy (p < 0.001). The HA-CDI predictors in the non-COVID patients were older age (p = 0.017), advanced-stage renal failure (p = 0.005), chemotherapy (p = 0.003), and a low albumin level (0.005). (4) Conclusion: Higher incidence rates of HAI-CDIs in COVID-19 patients did not occur due to reduced infection control precautions and hygiene measures but due to antibiotic therapy and therapy with other drugs used during the pandemic.

Effect of Reduced Fluoroquinolone Use on Cephalosporin Use, Susceptibilities and Clostridioides difficile Infections

Background: Overuse of fluoroquinolones has led to concerning rates of resistance, particularly among Gram-negative organisms. They are also highly implicated as a risk factor for Clostridioides difficile infection, and reports of other serious adverse events led to recommendations to restrict their use. Our health system began targeting the reduction in unnecessary fluoroquinolone prescribing in 2018, aiming to promote their safe and effective use. Broad-spectrum cephalosporins are often used as an alternative to fluoroquinolones. We sought to evaluate whether decreased fluoroquinolone use was associated with increased third- and fourth-generation cephalosporin use and whether these changes in utilization impacted other outcomes, including C. difficile infection (CDI) rates and susceptibilities among Gram-negative organisms. Methods: This retrospective descriptive analysis included adult patients who received a fluoroquinolone or broad-spectrum cephalosporin in a three-year time period across a large healthcare system. The primary objective was to evaluate the change in days of therapy (DOT) of fluoroquinolones and third- and fourth-generation cephalosporins. Secondary objectives included rates of resistance among common Gram-negative organisms, CDI, and analyses stratified by antibiotic indication. Results: Cephalosporin use increased by an average of 1.70 DOT/1000 PD per month (p < 0.001). Additionally, fluoroquinolone use decreased by an average of 1.18 DOT/1000 PD per month (p < 0.001). C. difficile infections decreased by 0.37 infections/10,000 patient-days per month (p < 0.001). Resistance to fluoroquinolones remained stable from 2018 to 2020, and a declining trend was observed in 2021. Conclusion: This study demonstrated that reduced fluoroquinolone use in a large healthcare system was associated with increased usage of broad-spectrum cephalosporins, decreased CDI and improvements in resistance patterns.

Association between Antibiotic Use and Hospital-Onset Clostridioides difficile Infection in University Tertiary Hospital in Serbia, 2011–2021: An Ecological Analysis

This ecological study is the largest to date examining the association between rates of antibiotic use (AU) and hospital-onset (HO) Clostridioides difficile infection (CDI) in a tertiary university hospital in Serbia. There was no clear trend in the incidence of HO-CDI over time. Total utilization of antibacterials for systemic use increased from 38.57 DDD/100 bed-days (BD) in 2011 to 56.39 DDD/100 BD in 2021. The most commonly used antibiotics were third-generation cephalosporins, especially ceftriaxone, with maximum consumption in 2021 (19.14 DDD/100 BD). The share of the Access group in the total utilization of antibiotics ranged from 29.95% to 42.96% during the observed period. The utilization of the Reserve group of antibiotics indicated a statistically significant increasing trend (p = 0.034). A statistically significant difference in the consumption of medium-risk antibiotics from 2011 to 2021 was shown for penicillins and a combination of sulfamethoxazole and trimethoprim. The consumption of cefotaxime showed a statistically significant negative association with the rate of HO-CDI (r = −0.647; p = 0.031). Ampicillin and the combination of amoxicilline with clavulanic acid have shown a negative statistically significant correlation with the ID of HO-CDI (r = −0.773 and r = −0.821, respectively). Moreover, there was a statistically significant negative correlation between consumption of “medium-risk antibiotics” and the rate of HO-CDI (r = −0.677). The next challenging step for the hospital multidisciplinary team for antimicrobials is to modify the antibiotic list according to the Access, Watch, and Reserve classification, in such a way that at least 60% of the AU should be from the Access group, according to the World Health Organization recommendation.

Genomic Analysis of Clostridioides difficile in 2 Regions of the United States Reveals a Diversity of Strains and Limited Transmission

BACKGROUND

The distribution of Clostridioides difficile strains and transmission dynamics in the United States are not well defined. Whole-genome sequencing across 2 Centers for Disease Control and Prevention Emerging Infections Program C. difficile infection (CDI) surveillance regions (Minnesota and New York) was performed to identify predominant multilocus sequence types (MLSTs) in community-associated (CA) and healthcare-associated (HCA) disease and assess transmission.

METHODS

Whole-genome sequencing was performed on C. difficile isolates from patients with CDI over 3 months between 2016 and 2017. Patients were residents of the catchment area without a positive C. difficile test in the preceding 8 weeks. CDI cases were epidemiologically classified as HCA or CA.

RESULTS

Of 422 isolates, 212 (50.2%) were HCA and 203 (48.1%) were CA. Predominant MLSTs were sequence type (ST) 42 (9.3%), ST8 (7.8%), and ST2 (8.1%). MLSTs associated with HCA-CDI included ST1 (76%), ST53 (83.3%), and ST43 (80.0%), while those associated with CA-CDI included ST3 (76.9%) and ST41 (77.8%). ST1 was more frequent in New York than in Minnesota (10.8% vs 3.1%). Thirty-three pairs were closely related genomically, 14 of which had potential patient-to-patient transmission supported by record review.

CONCLUSIONS

The genomic epidemiology of C. difficile across 2 regions of the United States indicates the presence of a diverse strain profile and limited direct transmission.

Urinary Tract Infections in Pennsylvania Long-Term Care Facilities

Urinary tract infections (UTIs) are common healthcare-associated infections (HAIs) in older adults that live in long-term care (LTC) facilities. A query of the Pennsylvania Patient Safety Reporting System (PA-PSRS) found that symptomatic UTI (SUTI) and catheter-associated UTI (CAUTI) rates increased from 2016 and peaked in the second quarter of 2020. Although the number of urinary catheter days reported by LTC facilities has trended downward from 2016 to the beginning of 2020, the urinary catheter utilization rate increased slightly in the second quarter of 2020. We also examined various epidemiological factors. An average of 47.6% of SUTIs and 32.3% of CAUTIs were associated with E. coli from 2016 through 2020. However, the percentage of CAUTIs associated with E. coli decreased while the percentage of CAUTIs associated with organisms of the tribe Proteeae (Proteus, Providencia, and Morganella genera) increased from 2016 through 2020. Furthermore, the percentage of CAUTIs associated with carbapenem-resistant Enterobacterales (CRE) and organisms producing extended-spectrum beta-lactamases (ESBL) also increased, while the percentage of CAUTIs associated with vancomycin-resistant Enterococci (VRE) decreased from 2016 through 2020. An average of 38.5% of SUTIs and 41.5% of CAUTIs were reported to be treated with fluoroquinolones from 2016 through 2020. However, the percentage of both SUTIs and CAUTIs treated with fluoroquinolones decreased from 2016 through 2020, while an increasing percentage of both SUTIs and CAUTIs was reported to have been treated with cephalosporins and carbapenems from 2016 through 2020. Thus, to further promote resident safety, we use these epidemiological trends to better understand current risks for residents and to further guide development of best practices for prevention, identification, and treatment of UTIs as well as to further advance antibiotic stewardship practices.

Microbial bioburden of inpatient and outpatient areas beyond patient hospital rooms

OBJECTIVE

To investigate the frequency of environmental contamination in hospital areas outside patient rooms and in outpatient healthcare facilities.

DESIGN

Culture survey.

SETTING

This study was conducted across 4 hospitals, 4 outpatient clinics, and 1 surgery center.

METHODS

We conducted 3 point-prevalence culture surveys for methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Clostridioides difficile, Candida spp, and gram-negative bacilli including Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter baumanii, and Stenotrophomonas maltophilia in each facility. In hospitals, high-touch surfaces were sampled from radiology, physical therapy, and mobile equipment and in emergency departments, waiting rooms, clinics, and endoscopy facilities. In outpatient facilities, surfaces were sampled in exam rooms including patient and provider areas, patient bathrooms, and waiting rooms and from portable equipment. Fluorescent markers were placed on high-touch surfaces and removal was assessed 1 day later.

RESULTS

In the hospitals, 110 (9.4%) of 1,195 sites were positive for 1 or more bacterial pathogens (range, 5.3%-13.7% for the 4 hospitals) and 70 (5.9%) were positive for Candida spp (range, 3.7%-5.9%). In outpatient facilities, 31 of 485 (6.4%) sites were positive for 1 or more bacterial pathogens (range, 2% to 14.4% for the 5 outpatient facilities) and 50 (10.3%) were positive for Candida spp (range, 3.9%-23.3%). Fluorescent markers had been removed from 33% of sites in hospitals (range, 28.4%-39.7%) and 46.3% of sites in outpatient clinics (range, 7.4%-82.8%).

CONCLUSIONS

Surfaces in hospitals outside patient rooms and in outpatient facilities are frequently contaminated with healthcare-associated pathogens. Improvements in cleaning and disinfection practices are needed to reduce contamination.

Clostridium difficile: Diagnosis and the Consequence of Over Diagnosis

Clostridium difficile infection (CDI) is a leading cause of healthcare-associated infections, accounting for significant disease burden and mortality. The clinical spectrum of C. difficile ranges from asymptomatic colonization to toxic megacolon and fulminant colitis. CDI is characterized by new onset of ≥ 3 unformed stools in 24 h and is confirmed by laboratory test for the presence of toxigenic C. difficile. Currently, laboratory tests to diagnose CDI include toxigenic culture, glutamate dehydrogenase (GDH), nucleic acid amplification test (NAAT), and toxins A/B enzyme immunoassay (EIA). The sensitivities of these tests are variable with toxin EIA ranging from 53 to 60% and with NAAT at about 95%. Overall, the specificity is > 90% for these methods. However, the positive predictive value (PPV) depends on the disease prevalence with lower CDI rates associated with lower PPVs.

Notably, the widespread use of the highly sensitive NAAT and its relatively lower clinical specificity have led to overdiagnosis of C. difficile by identifying carriers when NAAT is used as the sole diagnostic method. Overdiagnosis of C. difficile has resulted in unwarranted treatment, possibly attributing to resistance to metronidazole and vancomycin, increased risk for overgrowth of vancomycin-resistant enterococci strains in stool specimens, and increased hospitalization thereby impacting patient safety and healthcare costs.

Strategies to optimize the clinical sensitivity and specificity of current laboratory tests are critical to differentiate the clinical CDI from colonization. To achieve high diagnostic yield, if preagreed institutional criteria for stool submission are not used, a multistep approach to CDI diagnosis is recommended, such as either GDH or NAAT followed by toxins A/B EIA in conjunction with laboratory stewardship by evaluating C. difficile test orders for appropriateness and providing feedback. Furthermore, antimicrobial stewardship, along with provider education on appropriate testing for C. difficile, is vital to differentiate CDI from colonization.

Murine Intrarectal Instillation of Purified Recombinant Clostridioides difficile Toxins Enables Mechanistic Studies of Pathogenesis

Clostridioides difficile is linked to nearly 225,000 antibiotic-associated diarrheal infections and almost 13,000 deaths per year in the United States. Pathogenic strains of C. difficile produce toxin A (TcdA) and toxin B (TcdB), which can directly kill cells and induce an inflammatory response in the colonic mucosa. Hirota et al. (S. A. Hirota et al., Infect Immun 80:4474-4484, 2012) first introduced the intrarectal instillation model of intoxication using TcdA and TcdB purified from VPI 10463 (VPI 10463 reference strain [ATCC 43255]) and 630 C. difficile strains. Here, we expand this technique by instilling purified, recombinant TcdA and TcdB, which allows for the interrogation of how specifically mutated toxins affect tissue. Mouse colons were processed and stained with hematoxylin and eosin for blinded evaluation and scoring by a board-certified gastrointestinal pathologist. The amount of TcdA or TcdB needed to produce damage was lower than previously reported in vivo and ex vivo Furthermore, TcdB mutants lacking either endosomal pore formation or glucosyltransferase activity resemble sham negative controls. Immunofluorescent staining revealed how TcdB initially damages colonic tissue by altering the epithelial architecture closest to the lumen. Tissue sections were also immunostained for markers of acute inflammatory infiltration. These staining patterns were compared to slides from a human C. difficile infection (CDI). The intrarectal instillation mouse model with purified recombinant TcdA and/or TcdB provides the flexibility needed to better understand structure/function relationships across different stages of CDI pathogenesis.