How to: Surveillance of Clostridium difficile infections

Newly emerging metronidazole-resistant Clostridioides difficile PCR ribotype 955 identified in Poland, 2021 to 2023 but not in Czechia, 2012 to 2023 and Slovakia, 2015 to 2023

BackgroundOn 29 January 2024, the European Centre for Disease Prevention and Control distributed an alert about a metronidazole-resistant Clostridioides difficile outbreak of PCR ribotype (RT) 955 in England.AimWe aimed to investigate the presence of RT955 in Czech, Slovak and Polish C. difficile isolates and evaluate different culture media for detecting its metronidazole resistance.MethodsIsolates with binary toxin genes identified as 'unknown' by the WEBRIBO PCR ribotyping database up to 2023 were re-analysed after adding the RT955 profile to the database. The RT955 isolates were characterised by whole genome sequencing and tested for susceptibility to 15 antimicrobials.ResultsWe did not find RT955 in Czech (n = 6,661, 2012-2023) and Slovak (n = 776, 2015-2023) isolates, but identified 13 RT955 cases (n = 303, 2021-2023) in three hospitals in Poland. By whole genome multilocus sequence typing, 10 isolates clustered into one clonal complex including a sequence of United Kingdom strain ERR12670107, and shared similar antimicrobial resistance genes/mutations. All 13 isolates were resistant to ciprofloxacin/moxifloxacin, erythromycin/clindamycin and ceftazidime. All isolates had a mutation in the nimB gene promoter and in NimB (Tyr130Ser and Leu155Ile). The metronidazole resistance was detected in all isolates using brain-heart-infusion agar supplemented with haemin and Chocolate agar. Results were discrepant with the European Committee on Antimicrobial Susceptibility Testing-recommended Fastidious anaerobe agar and Brucella blood agar.ConclusionThe identification of clonally related haem-dependent metronidazole-resistant C. difficile RT955 in multiple hospitals indicates a need for prospective surveillance to estimate its prevalence in Europe.

Pilot study of Clostridioides difficile infection (CDI) in hospitals, Italy, September to December 2022

BackgroundClostridioides difficile infection (CDI) is a severe infection that needs to be monitored. This infection predominantly occurs in hospitalised patients after antimicrobial treatment, with high mortality in elderly patients.AimWe aimed at estimating the incidence of CDI in Italian hospitals over 4 months in 2022.MethodsWe estimated incidences of hospital-acquired CDI (HA-CDI), community or unknown CDI (CA/UA-CDI), recurrent CDI and overall CDI in 25 Italian hospitals, characterised C. difficile isolates using PCR ribotyping, analysed them for toxin genes and susceptibility to antimicrobials.ResultsClostridioides difficile was detected in 9.7% (655/6,722) of samples from 550 patients, 18 patients died of CDI. The mean overall CDI incidence was 5.0 cases per 10,000 patient days (range: 0.7-11.9). For HA-CDI, mean incidence was 3.7 (range: 0.7-9.2), for CA/UA-CDI 0.8 (range: 0.0-3.2) and for recurrent CDI 0.5 (range: 0.0-3.4). Most patients were female (n = 295; 53.6%), aged ≥ 65 years (n = 422; 76.7%) and previously hospitalised (n = 275; 50.0%). Of the 270 culturable isolates, 267 (98.9%) had toxin A and B genes and 51 (18.9%) the binary toxin genes. Of the 55 PCR ribotypes (RTs) identified, RT 018 (n = 56; 20.7%) and RT 607 (n = 23; 8.5%) were the most common, RT 607 in the northern (p < 0.0001) and RT 018 in the central (p < 0.0001) regions of Italy. Most isolates (n = 158; 58.5%) were antimicrobial-resistant and 119 (44.1%) were multidrug-resistant (MDR).ConclusionHighly virulent and MDR C. difficile types are circulating in Italian hospitals which highlights the need of robust surveillance and stringent prevention and control measures.

Structural insight into recognition of Clostridioides difficile toxin A by novel neutralizing nanobodies targeting QTIN-like motifs within its receptor-binding domain

Clostridioides difficile causes a large proportion of nosocomial colon infections by producing toxins TcdA and TcdB as key virulence factors. TcdA and TcdB have analogous domain structures with a receptor-binding domain containing C-terminal combined repetitive oligopeptides (CROPs), an attractive target for the development of therapeutic antibodies. Here, we identify and characterize two potent neutralizing single-domain camelid anti-CROPsA antibodies, C4.2 and H5.2, with distinct mechanisms of action. Peptide mapping, high-resolution crystal structures and site-directed mutagenesis revealed that C4.2 and H5.2 nanobodies target the same C-terminal epitope centered on a 2667QTIN2670 motif, yet utilize different paratopes. Only for C4.2 is the complex geometry compatible with multisite binding using QTIN-like repeats throughout the CROPsA domain, as supported by Western blotting, ELISA, and SEC-MALS analysis. H5.2 binding is stronger and more selective for the C-terminal epitope than C4.2, although both nanobodies are sufficient to neutralize TcdA individually. The described epitope does not overlap with previously described epitopes of anti-CROPs antibodies and provides new modalities for disease treatment and diagnostics.

Incidence and Risk Factors of Clostridium difficile Infection Among Adult Patients Admitted to the Inpatient Department of a Tertiary Care Hospital: A Hospital-Based Observational Study

Background Clostridium difficile infection (CDI) is a significant healthcare concern, marked by its rising prevalence and associated morbidity and mortality. However, there is limited data on the epidemiology of CDI in the eastern region of India. Objectives The study aims to determine the incidence of CDI among adult patients admitted to the inpatient department of a tertiary care hospital and identify the risk factors associated with CDI. Methodology A prospective observational study was conducted at a tertiary care hospital between October 2022 and March 2023. Using universal sampling, 200 adult patients were included in the study. Stool samples were collected within 24 hours of admission and again on the day of discharge or after one week, whichever period was longer. Relevant clinical, demographic, and laboratory data were also collected. The stool samples were analyzed for C. difficile toxins A and B using an enzyme immunoassay. Statistical analysis was performed using the mean and independent t-test for continuous variables, while proportions and Chi-square or Fisher's exact tests were applied for categorical variables. Results The incidence of CDI during the study period was 9%. The participants had a mean age of 46.49 ± 16.78 years, with a predominance of males (60%). Acute febrile illness was the most common diagnosis at admission (36%). The mean duration of hospitalization was significantly longer in patients who tested positive for C. difficile toxins via enzyme-linked immunosorbent assay compared to those who tested negative (8.0 ± 1.53 days vs. 3.75 ± 1.25 days, p < 0.001). Exposure to broad-spectrum antibiotics, particularly third-generation cephalosporins, was significantly associated with CDI development. Additionally, fecal leukocytes were detected in all (100%) patients who tested positive for C. difficile toxins. Conclusions This study offers important insights into the incidence and risk factors of CDI among adult patients in a tertiary care setting. The findings emphasize the need for the judicious use of broad-spectrum antibiotics to reduce the risk of CDI. Additionally, the detection of fecal leukocytes may serve as a valuable diagnostic marker for CDI in clinical practice.

Antimicrobial Resistance and Associated Risk Factors for Clostridium difficile in Patients Attending Tertiary Care Settings

To determine the incidence of antimicrobial-resistant emerging pathogens, Clostridium difficile, and its associated risk factors in tertiary care setups of Pakistan. This cross-sectional prospective study was conducted from January 2019 to December 2020, to determine the prevalence and antimicrobial resistance patterns of C. difficile strains isolated from 450 stool specimens of patients suffering from diarrhea hospitalized in tertiary care hospitals in Peshawar, Pakistan. The stool samples of the patients were processed for culture and detection of toxin A and toxin B by enzyme-linked immunosorbent assay (ELISA) and tpi PCR. The drug sensitivity test was performed for antibiotics including ampicillin, cefixime, cefepime, amoxicillin, nalidixic acid, sulpha/TMP (SXT), chloramphenicol, metronidazole, vancomycin, ciprofloxacin, levofloxacin, and imipenem. Of 450 stool specimens, 108 (24%) were positive for C. difficile by stool culture, whereas 115 (25.5%) were only positive for C. difficile toxins based on ELISA and PCR (128 (28.6%). Of 108, 90.7% (n = 98) isolates were resistant to one antibiotic, and 90 (83.4%) were resistant to three or more antimicrobials. The highest resistance rates were found against penicillin (83.3%) followed by amoxicillin (70%), nalidixic acid (61%), and metronidazole (38%), and the lowest resistance was found against vancomycin (6.4%) and imipenem (3.7%). CDI was statistically significantly correlated with increased age, use of antibiotics, abdominal surgeries, use of proton pump inhibitors and H2a, and presence of comorbidities. The high frequency of C. difficile in Peshawar, Pakistan, indicates that CDI is an important nosocomial infection in different hospitals. The results will be helpful for clinicians to redesign control and therapeutic strategies in hospitals.

Early identification of a ward-based outbreak of Clostridioides difficile using prospective multilocus sequence type-based Oxford Nanopore genomic surveillance

OBJECTIVE

To describe an outbreak of sequence type (ST)2 Clostridioides difficile infection (CDI) detected by a recently implemented multilocus sequence type (MLST)-based prospective genomic surveillance system using Oxford Nanopore Technologies (ONT) sequencing.

SETTING

Hemato-oncology ward of a public tertiary referral centre.

METHODS

From February 2022, we began prospectively sequencing all C. difficile isolated from inpatients at our institution on the ONT MinION device, with the output being an MLST. Bed-movement data are used to construct real-time ST-specific incidence charts based on ward exposures over the preceding three months.

RESULTS

Between February and October 2022, 76 of 118 (64.4%) CDI cases were successfully sequenced. There was wide ST variation across cases and the hospital, with only four different STs being seen in >4 patients. A clear predominance of ST2 CDI cases emerged among patients with exposure to our hemato-oncology ward between May and October 2022, which totalled ten patients. There was no detectable rise in overall CDI incidence for the ward or hospital due to the outbreak. Following a change in cleaning product to an accelerated hydrogen peroxide wipe and several other interventions, no further outbreak-associated ST2 cases were detected. A retrospective phylogenetic analysis using original sequence data showed clustering of the suspected outbreak cases, with the exception of two cases that were retrospectively excluded from the outbreak.

CONCLUSIONS

Prospective genomic surveillance of C. difficile using ONT sequencing permitted the identification of an outbreak of ST2 CDI that would have otherwise gone undetected.

Evaluation of a surveillance system for Clostridioides difficile infections for Swiss hospitals

AIMS

This study evaluated an approach to establishing a comprehensive nationwide surveillance system for Clostridioides difficile infection in Switzerland. We report the results of patient-related surveillance and calculate the incidence rate of C. difficile infection in Switzerland in 2022.

METHODS

Initiated in 2017 by the National Centre for Infection Prevention (Swissnoso), in collaboration with the Swiss Centre for Antibiotic Resistance (ANRESIS), laboratory surveillance enables the automatic import of C. difficile infection laboratory data and is fully operational. However, the very limited number of participating laboratories impedes the generation of representative results. To address this gap, Swissnoso introduced patient-related surveillance, with a questionnaire-based survey used across Swiss acute care hospitals.

RESULTS

This survey revealed an incidence of 3.8 (Poisson 95% CI: 3.2-4.5) C. difficile infection episodes per 10,000 patient-days, just above the mean rate reported by the European Centre for Disease Prevention and Control (ECDC). Additionally, we report substantial heterogeneity in laboratory tests, diagnostic criteria and infection control practices among Swiss hospitals.

CONCLUSION

This study underscores the importance of a joint effort towards standardized surveillance practices in providing comprehensive insights into C. difficile infection epidemiology and effective prevention strategies in Swiss healthcare settings. The patient-related approach remains the gold standard for C. difficile infection surveillance, although it demands substantial resources and provides results only annually. The proposed implementation of nationwide automated laboratory-based surveillance would be pragmatic and efficient, empowering authorities and hospitals to detect outbreaks promptly and to correlate infection rates with antibiotic consumption.

Rethinking Clostridioides difficile infection (CDI) surveillance definitions based on changing healthcare utilisation and a more realistic incubation period: reviewing data from a tertiary-referral hospital, Ireland, 2012 to 2021

BackgroundCommunity-associated Clostridioides difficile infections (CA-CDI) have increased worldwide. Patients with CDI-related symptoms occurring < 48 hours after hospitalisation and no inpatient stay 12 weeks prior are classified as CA-CDI, regardless of hospital day attendances 3 months before CDI onset. Healthcare-associated (HA) CDIs include those with symptom onset ≥ 48 hours post hospitalisation.AimTo consider an incubation period more reflective of CDI, and changing healthcare utilisation, we measured how varying surveillance specifications to categorise patients according to their CDI origin resulted in changes in patients' distribution among CDI origin categories.MethodsNew CDI cases between 2012-2021 from our hospital were reviewed. For patients with CA-CDI, hospital day attendances in the 3 months prior were recorded. CA-CDI patients with hospital day attendances and recently discharged CDI patients (RD-CDI; CDI onset 4-12 weeks after discharge) were combined into a new 'healthcare-exposure' category (HE-CDI). Time from hospitalisation to disease onset was varied and the midpoint between optimal and balanced cut-offs was used instead of 48 hours to categorise HA-CDI.ResultsOf 1,047 patients, 801 (76%) were HA-CDI, 205 (20%) CA-CDI and 41 (4%) were RD-CDI. Of the CA-CDI cohort, 45 (22%) met recent HE-CDI criteria and, when reassigned, reduced CA-CDI to 15%. Sensitivity analysis indicated a day 4 cut-off for assigning HA-CDI. Applying this led to 46 HA-CDI reassigned as CA-CDI. Applying both HE and day 4 criteria led to 72% HA-CDI, 20% CA-CDI, and 8% HE-CDI (previously RD-CDI).ConclusionCDI surveillance specifications reflecting healthcare exposure and an incubation period more characteristic of C. difficile may improve targeted CDI prevention interventions.

The Need for European Surveillance of CDI

Since the turn of the millennium, the epidemiology of Clostridioides difficile infection (CDI) has continued to challenge. Changes in clinical presentation, severity of disease, descriptions of new risk factors and the occurrence of outbreaks all emphasised the importance of early diagnosis and standardised surveillance systems. However, a lack of consensus on case definitions, clinical guidelines and optimal laboratory diagnostics across Europe has led to the underestimation of CDI and impeded comparison between countries. These inconsistencies have prevented the true burden of disease from being appreciated.Acceptance that a multi-country CDI surveillance program and optimised diagnostic strategies are required has built the foundations for a more robust, unified surveillance. The concerted efforts of the European Centre for Disease Prevention and Control (ECDC) CDI networks led to the development of the European surveillance protocol and an over-arching long-term CDI surveillance strategy for 2014-2020, which has been followed by the development of surveillance systems in at least 20 European countries. However, surveillance activities in individual countries have slowed during the COVID-19 pandemic as resources were diverted to the global health crisis. A renewed and strengthened focus on CDI surveillance and prevention is therefore urgently needed post COVID-19.

The ESCMID Study Group for Clostridioides difficile: History, Role, and Perspectives

Clostridioides difficile (C. difficile) is a major nosocomial pathogen but is also increasingly recognised as an important diarrhoeal pathogen in the community, not always associated with antibiotics. The European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for C. difficile (ESGCD) is a group of clinicians, scientists, and others from many European countries and further afield, who share a common interest in C. difficile. The aims of the Study Group are centred around raising the profile of  C. difficile infection (CDI) in humans and animals, fostering collaboration amongst centres in different European countries and providing a forum for discussing and disseminating information. One of the principal aims of the Study Group is to raise awareness of C. difficile infections in Europe. ESGCD has a particular interest in the development and dissemination of European guidance on prevention, diagnosis, and treatment of CDI. This chapter will discuss the organisation of ESGCD within the ESCMID Study Group structure, the origins of the Study Group, the aims, and objectives of the group, and will highlight some of the past and present activities of ESGCD in relation to these.

Characterization of community-acquired Clostridioides difficile strains in Israel, 2020-2022

Background

The prevalence of community-acquired Clostridioides difficile infection (CA-CDI) has been rising, due to changes in antibiotics prescribing practices, emergence of hypervirulent strains and improved diagnostics. This study explored CA-CDI epidemiology by examining strain diversity and virulence factors of CA-CDI isolates collected across several geographical regions in Israel.

Methods

Stool samples of 126 CA-CDI patients were subjected to PCR and an immunoassay to identify toxin genes and proteins, respectively. Toxin loci PaLoc and PaCdt were detected by whole-genome sequencing (WGS). Biofilm production was assessed by crystal violet-based assay. Minimum inhibitory concentration was determined using the Etest technique or agar dilution. WGS and multi-locus sequence typing (MLST) were used to classify strains and investigate genetic diversity.

Results

Sequence types (ST) 2 (17, 13.5%), ST42 (13, 10.3%), ST104 (10, 8%) and ST11 (9, 7.1%) were the most common. All (117, 92.8%) but ST11 belonged to Clade 1. No associations were found between ST and gender, geographic area or antibiotic susceptibility. Although all strains harbored toxins genes, 34 (27%) produced toxin A only, and 54 (42.9%) strains produced toxin B only; 38 (30.2%) produced both toxins. Most isolates were biofilm-producers (118, 93.6%), primarily weak producers (83/118, 70.3%). ST was significantly associated with both biofilm and toxin production.

Conclusion

C. difficile isolates in Israel community exhibit high ST diversity, with no dominant strain. Other factors may influence the clinical outcomes of CDI such as toxin production, antibiotic resistance and biofilm production. Further studies are needed to better understand the dynamics and influence of these factors on CA-CDI.

Clostridioides difficile Infections among Pediatric Patients Hospitalized at an Oncology Department of a Tertiary Hospital in Poland

Background and Objectives: Gastrointestinal tract infections caused by Clostridioides difficile bacteria are diagnosed in pediatric patients with increasing frequency. Children treated at pediatric units are a group of patients at high risk of this infection; therefore, appropriate differential diagnostics and an individual approach to every case are of particular importance. The goal of the study was to assess the clinical parameters of patients with a confirmed CD infection and colonization. Materials and Methods: Every positive case was subjected to a retrospective analysis based on medical history and an infection notification note. Results: Positive results were obtained for 30 patients, among whom the results of 18 patients were considered to justify the diagnosis of an infection. In the remaining patients, treatment was not initiated in only three cases. Cases were detected where treatment was initiated despite the lack of sufficient clinical evidence. Conclusions: This study demonstrates that there are many factors that result in a high risk of the occurrence of CDI in oncology patients, such as antibiotic therapy, multiple hospitalizations, and myelosuppression.

Clostridioides difficile infections were predominantly driven by fluoroquinolone-resistant Clostridioides difficile ribotypes 176 and 001 in Slovakia in 2018-2019

AIM

To investigate the epidemiology of Clostridioides difficile infection (CDI) in Slovakian hospitals after the emergence of ribotype 176 (027-like) in 2016.

METHODS

Between 2018 and 2019, European Centre for Disease Control and Prevention CDI surveillance protocol v2.3 was applied to 14 hospitals, with additional data collected on recent antimicrobial use and the characterization of C. difficile isolates.

RESULTS

The mean hospital incidence of CDI was 4.1 cases per 10,000 patient bed-days. One hundred and five (27.6%) in-hospital deaths were reported among the 381 cases. Antimicrobial treatment within the previous 4 weeks was recorded in 90.5% (333/368) of cases. Ribotype (RT)176 was detected in 50% (n=185/370, 14 hospitals) and RT001 was detected in 34.6% (n=128/370,13/14 hospitals) of cases with RT data. Overall, 86% (n=318/370) of isolates were resistant to moxifloxacin by Thr82Ile in GyrA (99.7%). Multi-locus variable tandem repeat analysis showed clonal relatedness of predominant RTs within and between hospitals. Seven of 14 sequenced RT176 isolates and five of 13 RT001 isolates showed between zero and three allelic differences by whole-genome multi-locus sequence typing. The majority of sequenced isolates (24/27) carried the erm(B) gene and 16/27 also carried the aac(6')-aph(2'') gene with the corresponding antimicrobial susceptibility phenotypes. Nine RT176 strains carried the cfr(E)gene and one RT001 strain carried the cfr(C) gene, but without linezolid resistance.

CONCLUSIONS

The newly-predominant RT176 and endemic RT001 are driving the epidemiology of CDI in Slovakia. In addition to fluoroquinolones, the use of macrolide-lincosamide-streptogramin B antibiotics can represent another driving force for the spread of these epidemic lineages. In C. difficile, linezolid resistance should be confirmed phenotypically in strains with detected cfr gene(s).

Clostridioides difficile Toxin B Induced Senescence: A New Pathologic Player for Colorectal Cancer?

Clostridioides difficile (C. difficile) is responsible for a high percentage of gastrointestinal infections and its pathological activity is due to toxins A and B. C. difficile infection (CDI) is increasing worldwide due to the unstoppable spread of C. difficile in the anthropized environment and the progressive human colonization. The ability of C. difficile toxin B to induce senescent cells and the direct correlation between CDI, irritable bowel syndrome (IBS), and inflammatory bowel diseases (IBD) could cause an accumulation of senescent cells with important functional consequences. Furthermore, these senescent cells characterized by long survival could push pre-neoplastic cells originating in the colon towards the complete neoplastic transformation in colorectal cancer (CRC) by the senescence-associated secretory phenotype (SASP). Pre-neoplastic cells could appear as a result of various pro-carcinogenic events, among which, are infections with bacteria that produce genotoxins that generate cells with high genetic instability. Therefore, subjects who develop IBS and/or IBD after CDI should be monitored, especially if they then have further CDI relapses, waiting for the availability of senolytic and anti-SASP therapies to resolve the pro-carcinogenic risk due to accumulation of senescent cells after CDI followed by IBS and/or IBD.

Clostridium difficile Infections in an Emergency Surgical Unit from North-East Romania

Background and Objectives: Colitis with Clostridium difficile is an important health problem that occurs with an intensity that varies between mild and severe. Surgical interventions are required only in fulminant forms. There is little evidence regarding the best surgical intervention in these cases. Materials and Methods: Patients with C. difficile infection were identified from the two surgery clinics from the 'Saint Spiridon' Emergency Hospital Iași, Romania. Data regarding the presentation, indication for surgery, antibiotic therapy, type of toxins, and post-operative outcomes were collected over a 3-year period. Results: From a total of 12,432 patients admitted for emergency or elective surgery, 140 (1.12%) were diagnosed with C. difficile infection. The mortality rate was 14% (20 cases). Non-survivors had higher rates of lower-limb amputations, bowel resections, hepatectomy, and splenectomy. Additional surgery was necessary in 2.8% of cases because of the complications of C. difficile colitis. In three cases, terminal colostomy was performed and as well as one case with subtotal colectomy with ileostomy. All patients who required the second surgery died within the 30-day mortality period. Conclusions: In our prospective study, the incidence was increased both in cases of patients with interventions on the colon and in those requiring limb amputations. Surgical interventions are rarely required in patients with C. difficile colitis.

Incidence of healthcare-associated Clostridioides difficile infection in a quaternary referral university hospital in Brazil

Clostridioides difficile infection (CDI) is an important cause of diarrhea in hospitals worldwide. The incidence of CDI in Latin America has not yet been standardized. To fill this gap, the present study performed a daily active surveillance, for three months, between April to July of 2021, at a quaternary referral university hospital in Brazil. The incidence density was 9.2 cases per 10,000 patient-days. Cases were associated mostly with ribotypes 014 and 106 (44% and 22%, respectively). Ribotype 027 was not identified. The findings strongly reinforce the need for broad epidemiological studies on the incidence of CDI in Brazilian hospitals to increase the understanding, prevention, and treatment of this infection.

Clostridioides difficile: Characterization of the circulating toxinotypes in an Argentinean public hospital

Clostridioides difficile is a spore-forming anaerobe microorganism associated to nosocomial diarrhea. Its virulence is mainly associated with TcdA and TcdB toxins, encoded by their respective tcdA and tcdB genes. These genes are part of the pathogenicity locus (PaLoc). Our aim was to characterize relevant C. difficile toxinotypes circulating in the hospital setting. The tcdA and tcdB genes were amplified and digested with different restriction enzymes: EcoRI for tcdA; HincII and AccI for tcdB. In addition, the presence of the cdtB (binary toxin) gene, TcdA and TcdB toxins by dot blot and the cytotoxic effect of culture supernatants on Vero cells, were evaluated. Altogether, these studies revealed three different circulating toxinotypes according to Rupnik's classification: 0, I and VIII, being the latter the most prevalent one. Even though more studies are certainly necessary (e.g. sequencing analysis), it is worth noting that the occurrence of toxinotype I could be related to the introduction of bacteria from different geographical origins. The multivariate analysis conducted on the laboratory values of individuals infected with the most prevalent toxinotype (VIII) showed that the isolates associated with fatal outcomes (GCD13, GCD14 and GCD22) are located in regions of the biplots related to altered laboratory values at admission. In other patients, although laboratory values at admission were not correlated, levels of urea, creatinine and white blood cells were positively correlated after the infection was diagnosed. Our study reveals the circulation of different toxinotypes of C. difficile strains in this public hospital. The variety of toxinotypes can arise from pre-existing microorganisms as well as through the introduction of bacteria from other geographical regions. The existence of microorganisms with different pathogenic potential is relevant for the control, follow-up, and treatment of the infections.

European survey on the current surveillance practices, management guidelines, treatment pathways and heterogeneity of testing of Clostridioides difficile, 2018-2019: results from The Combatting Bacterial Resistance in Europe CDI (COMBACTE-CDI)

BACKGROUND

Awareness and compliance with international guidelines for diagnosis and clinical management of Clostridioides difficile infection (CDI) are unknown.

AIM

To compare the awareness and compliance with the recommended strategies for diagnosis and clinical management of CDI across Europe in 2018-2019.

METHODS

Hospital sites and their associated community practices across 12 European countries completed an online survey in 2018-2019, to report on their practices in terms of surveillance, prevention, diagnosis, and treatment of CDI. Responses were collected from 105 hospitals and 39 community general practitioners (GPs).

FINDINGS

Hospital sites of 11 countries reported participation in national surveillance schemes compared with six countries for international schemes. The European Society of Clinical Microbiology and Infectious Diseases (ESCMID)-recommended CDI testing methodologies were used by 82% (86/105) of hospitals, however countries reporting the highest incidence of CDI used non-recommended tests. Over 75% (80/105) of hospitals were aware of the most recent European CDI treatment guidelines at the time of this survey compared with only 26% (10/39) of surveyed GPs. However, up to 15% (16/105) of hospitals reported using the non-recommended metronidazole for recurrent CDI cases, sites in countries with lower awareness of CDI treatment guidelines. Only 37% (39/105) of hospitals adopted contact isolation precautions in case of suspected CDI.

CONCLUSION

Good awareness of guidelines for the management of CDI was observed across the surveyed European hospital sites. However, low compliance with diagnostic testing guidelines, infection control measures for suspected CDI, and insufficient awareness of treatment guidelines continued to be reported in some countries.

Ribotyping of Clostridioides difficile in the Liberec Regional Hospital: a tertiary health care facility

The ribotyping of Clostridioides difficile is one of the basic methods of molecular epidemiology for monitoring the spread of C. difficile infections. In the Czech Republic, this procedure is mainly available in university hospitals. The introduction of ribotyping in a tertiary health care facility such as Liberec Regional Hospital not only increases safety in the facility but also supports regional professional development. In our study, 556 stool samples collected between June 2017 and June 2018 were used for C. difficile infection screening, followed by cultivation, toxinotyping, and ribotyping of positive samples. The toxinotyping of 96 samples revealed that 44.8% of typed strains could produce toxins A and B encoded by tcdA and tcdB, respectively. The ribotyping of the same samples revealed two epidemic peaks, caused by the regionally most prevalent ribotype 176 (n = 30, 31.3). C. difficile infection incidence ranged between 5.5 and 4.2 cases per 10,000 patient-bed days. Molecular diagnostics and molecular epidemiology are the two most developing parts of clinical laboratories. The correct applications of molecular methods help ensure greater safety in hospitals.

Make It Less difficile: Understanding Genetic Evolution and Global Spread of Clostridioides difficile

Clostridioides difficile is an obligate anaerobic pathogen among the most common causes of healthcare-associated infections. It poses a global threat due to the clinical outcomes of infection and resistance to antibiotics recommended by international guidelines for its eradication. In particular, C. difficile infection can lead to fulminant colitis associated with shock, hypotension, megacolon, and, in severe cases, death. It is therefore of the utmost urgency to fully characterize this pathogen and better understand its spread, in order to reduce infection rates and improve therapy success. This review aims to provide a state-of-the-art overview of the genetic variation of C. difficile, with particular regard to pathogenic genes and the correlation with clinical issues of its infection. We also summarize the current typing techniques and, based on them, the global distribution of the most common ribotypes. Finally, we discuss genomic surveillance actions and new genetic engineering strategies as future perspectives to make it less difficile.

Clostridioides difficile epidemiology in the Middle and the Far East

OBJECTIVES

Clostridioides difficile is an important pathogen of healthcare-associated gastrointestinal infections. Recently, an increased number of C. difficile infection (CDI) surveillance data has been reported from Asia. The aim of this review is to summarize the data on the prevalence, distribution and molecular epidemiology of CDI in the Middle and the Far East.

METHODS

Literature was drawn from a search of PubMed up to September 30, 2021.

RESULTS

The meta-analysis of data from 111 studies revealed the pooled CDI prevalence rate in the Middle and the Far East of 12.4% (95% CI 11.4-13.3); 48 studies used PCR for CDI laboratory diagnoses. The predominant types (RT)/sequence type (ST) differ between individual countries (24 studies, 14 countries). Frequently found RTs were 001, 002, 012, 017, 018 and 126; RT017 was predominant in the Far East. The epidemic RT027 was detected in 8 countries (22 studies), but its predominance was reported only in three studies (Israel and Iran). The contamination of vegetable and meat or meat products and/or intestinal carriage of C. difficile in food and companion animals have been reported; the C. difficile RTs/STs identified overlapped with those identified in humans.

CONCLUSIONS

A large number of studies on CDI prevalence in humans from the Middle and the Far East have been published; countries with no available data were identified. The number of studies on C. difficile from non-human sources is limited. Comparative genomic studies of isolates from different sources are needed.

Motility and the genotype diversity of the flagellin genes fliC and fliD among Clostridioides difficile ribotypes

OBJECTIVE

The motility and genotype of the flagellin fliC and fliD genes were investigated in 82 Clostridioides difficile isolates belonging to the ribotypes (RTs): 027 (n = 41), 176 (n = 17), 023 (n = 8), 017 (n = 6) and 046 (n = 10). The reference C. difficile strains 630 and M120 were included as controls for the motility assay.

METHODS

A Multiple Locus Variable-number Tandem Repeat Analysis (MLVA) was used to exclude the genetic relatedness of C. difficile isolates belonging to the same RT. The variability of the fliC and fliD genes was determined by PCR-restriction fragment length polymorphism (RFLP) analysis and Sanger sequencing. The motility assay was carried out with 0.175% BHI agar tubes and BHI solid media plates with 0.4% agar.

RESULTS

The highest motility was observed in C. difficile RT023 isolates (p < 0.01), followed by RTs 027 and 176. C. difficile isolates of RTs 017 and 046 were less motile than RTs 027, 176 and 023 (p < 0.01). The fliC and fliD genes were present in all clinical isolates irrespective of the motility results. In the fliC gene analysis, four different RFLP groups were identified (I, II, VII, X). The fliC group VII was identified in two RTs (027 and 176), whereas the remaining three groups (I, II and X) belonged to a single RT 046, 017 and 023, respectively. The fliD gene analysis identified four new RFLP groups (a, b, c and d).

CONCLUSIONS

C. difficile RT023 is highly motile and its motility is comparable to the hypervirulent RT027 and its genetic relative RT176.

Clostridioides difficile: Current overview and future perspectives

The most common world-wide cause of antibiotic-associated infectious diarrhea and colitis is the toxin producing bacterium, Clostridioides difficile (C. difficile). Here we review the background and characteristics of the bacterium and the toxins produced together with the epidemiology and the complex pathogenesis that leads to a broad clinical spectrum of disease. The review describes the difficulties faced in obtaining a quick and accurate diagnosis despite the range of sensitive and specific diagnostic tools available. We also discuss the problem of disease recurrence and the importance of disease prevention. The high rates of infection recurrence mean that treatment strategies are constantly under review and we outline the diverse treatment options that are currently in use and explore the emerging treatment options of pulsed antibiotic use, microbial replacement therapies and the use of monoclonal antibodies. We summarize the future direction of treatment strategies which include the development of novel antibiotics, the administration of oral polyclonal antibody formulations, the use of vaccines, the administration of competitive non-toxigenic spores and the neutralization of antibiotics at the microbiota level. Future successful treatments will likely involve a combination of therapies to provide the most effective and robust approach to C. difficile management.

rRNA Analysis Based on Long-Read High-Throughput Sequencing Reveals a More Accurate Diagnostic for the Bacterial Infection of Ascites

Traditional pathogenic diagnosis presents defects such as a low positivity rate, inability to identify uncultured microorganisms, and time-consuming nature. Clinical metagenomics next-generation sequencing can be used to detect any pathogen, compensating for the shortcomings of traditional pathogenic diagnosis. We report third-generation long-read sequencing results and second-generation short-read sequencing results for ascitic fluid from a patient with liver ascites and compared the two types of sequencing results with the results of traditional clinical microbial culture. The distribution of pathogenic microbial species revealed by the two types of sequencing results was quite different, and the third-generation sequencing results were consistent with the results of traditional microbial culture, which can effectively guide subsequent treatment. Short reads, the lack of amplification, and enrichment to amplify signals from trace pathogens, and host background noise may be the reasons for the high error in the second-generation short-read sequencing results. Therefore, we propose that long-read-based rRNA analysis technology is superior to the short-read shotgun-based metagenomics method in the identification of pathogenic bacteria.

Genetic diversity and phylogenetic analysis of the surface layer protein A gene (slpA) among Clostridioides difficile clinical isolates from Tehran, Iran

Clostridioides difficile is the most common causative agent of healthcare-associated diarrhea. C. difficile strains produce a crystalline surface layer protein (SlpA), encoded by the slpA gene. Previous studies have shown that SlpA varies among C. difficile strains. In this study, we used the SlpA sequence-based typing system (SlpAST) for the molecular genotyping of C. difficile clinical isolates identified in Iran; the PCR ribotypes (RTs) and toxin profiles of the isolates were also characterized. Forty-eight C. difficile isolates were obtained from diarrheal patients, and characterized by capillary electrophoresis (CE) PCR ribotyping and the detection of toxin genes. In addition, the genetic diversity of the slpA gene was investigated by Sanger sequencing. The most common RTs were RT126 (20.8%), followed by RT001 (12.5%) and RT084 (10.4%). The intact PaLoc arrangement representing cdu2+/tcdR+/tcdB+/tcdE+/tcdA+/tcdC+/cdd3+ profile was the predominant pattern and cdtA and cdtB genes were found in one-third of the isolates. Using the SlpA genotyping, 12 main genotypes and 16 subtypes were identified. The SlpA type 078-1 was the most prevalent genotype (20.8%), and identified within the isolates of RT126. The yok-1, gr-1, cr-1 and kr-3 genotypes were detected in 14.5%, 12.5%, 12.5% and 8.3% of isolates, respectively. Almost all the isolates with the same RT were clustered in similar SlpA sequence types. In comparison to PCR ribotyping, SlpAST, as a simple and highly reproducible sequenced-based technique, can discriminate well between C. difficile isolates. This typing method appears to be a valuable tool for the epidemiological study of C. difficile isolates worldwide.

The efficacy and safety of acid suppressants for gastrointestinal bleeding prophylaxis in cardiac care unit patients

BACKGROUND AND AIM

Concerns regarding adverse events associated with proton pump inhibitors (PPIs) and histamine-2 receptor antagonists (H2RAs) for gastrointestinal bleeding (GIB) prophylaxis in the intensive care unit have increased in recent years. Few studies have focused on acid suppressant use in the cardiac care unit (CCU) setting exclusively. We performed a cohort study to determine the efficacy and safety of acid suppressants for GIB prophylaxis in CCU patients.

METHODS

This retrospective cohort study included adults who were admitted directly to the CCU for more than 2 days from January 1, 2014, to April 30, 2019. The Crusade score was calculated to evaluate the risk of GIB. The primary outcomes were clinically important gastrointestinal bleeding (CIGIB), hospital-acquired pneumonia (HAP), and in-hospital mortality.

RESULTS

Of the 3318 patients enrolled, 2284 (68.8%) patients received PPIs, 515 (15.5%) received H2RAs, and 519 (15.7%) received no acid suppressants. After adjusting for potential confounders, utilization of PPIs (2.69, 95% confidence interval [0.62-11.73]) and H2RAs (1.41, 95% confidence interval [0.19-10.36]) were not associated with a lower risk of CIGIB than the control. Sensitivity analyses revealed that PPI use was an independent risk factor for in-hospital mortality in patients over 75 years old, with an adjusted odds ratio of 4.08 (1.14-14.63). PPIs increased the risk of HAP in patients over 75 years old and in those with heart failure, with adjusted odds ratios of 2.38 (1.06-5.34) and 2.88 (1.34-7.28), respectively.

CONCLUSIONS

Proton pump inhibitors and H2RAs for GIB prophylaxis in CCU patients were not associated with a lower risk of CIGIB than the controls. PPI therapy is associated with increased risks of HAP and in-hospital mortality in patients over 75 years old. PPIs may increase the risk of HAP in patients with heart failure.

Transition From PCR-Ribotyping to Whole Genome Sequencing Based Typing of Clostridioides difficile

Clostridioides difficile causes nosocomial outbreaks which can lead to severe and even life-threatening colitis. Rapid molecular diagnostic tests allow the identification of toxin-producing, potentially hypervirulent strains, which is critical for patient management and infection control. PCR-ribotyping has been used for decades as the reference standard to investigate transmission in suspected outbreaks. However, the introduction of whole genome sequencing (WGS) for molecular epidemiology provides a realistic alternative to PCR-ribotyping. In this transition phase it is crucial to understand the strengths and weaknesses of the two technologies, and to assess their correlation. We aimed to investigate ribotype prediction from WGS data, and options for analysis at different levels of analytical granularity. Ribotypes cannot be directly determined from short read Illumina sequence data as the rRNA operons including the ribotype-defining ISR fragments collapse in genome assemblies, and comparison with traditional PCR-ribotyping results becomes impossible. Ribotype extraction from long read Oxford nanopore data also requires optimization. We have compared WGS-based typing with PCR-ribotyping in nearly 300 clinical and environmental isolates from Switzerland, and in addition from the Enterobase database (n=1778). Our results show that while multi-locus sequence type (MLST) often correlates with a specific ribotype, the agreement is not complete, and for some ribotypes the resolution is insufficient. Using core genome MLST (cgMLST) analysis, there is an improved resolution and ribotypes can often be predicted within clusters, using cutoffs of 30-50 allele differences. The exceptions are ribotypes within known ribotype complexes such as RT078/RT106, where the genome differences in cgMLST do not reflect the ribotype segregation. We show that different ribotype clusters display different degrees of diversity, which could be important for the definition of ribotype cluster specific cutoffs. WGS-based analysis offers the ultimate resolution to the SNP level, enabling exploration of patient-to-patient transmission. PCR-ribotyping does not sufficiently discriminate to prove nosocomial transmission with certainty. We discuss the associated challenges and opportunities in a switch to WGS from conventional ribotyping for C. difficile.

A significant decreased in the frequency of Clostridioides difficile infection at the Italian Hospital of Desio over the last decade

Clostridiodes difficile infection (CDI) is the most important cause of healthcare-associated diarrhea. The decreasing trend of CDI from 15% to 4% observed at the Italian Hospital of Desio over a 10-year period is due to prevention strategies. Our data highlight the importance of surveillance studies to control CDI.

Mortality Following Clostridioides difficile Infection in Europe: A Retrospective Multicenter Case-Control Study

We aimed to describe the clinical presentation, treatment, outcome and report on factors associated with mortality over a 90-day period in Clostridioides difficile infection (CDI). Descriptive, univariate, and multivariate regression analyses were performed on data collected in a retrospective case-control study conducted in nine hospitals from seven European countries. A total of 624 patients were included, of which 415 were deceased (cases) and 209 were still alive 90 days after a CDI diagnosis (controls). The most common antibiotics used previously in both groups were β-lactams; previous exposure to fluoroquinolones was significantly (p = 0.0004) greater in deceased patients. Multivariate logistic regression showed that the factors independently related with death during CDI were older age, inadequate CDI therapy, cachexia, malignancy, Charlson Index, long-term care, elevated white blood cell count (WBC), C-reactive protein (CRP), bacteraemia, complications, and cognitive impairment. In addition, older age, higher levels of WBC, neutrophil, CRP or creatinine, the presence of malignancy, cognitive impairment, and complications were strongly correlated with shortening the time from CDI diagnosis to death. CDI prevention should be primarily focused on hospitalised elderly people receiving antibiotics. WBC, neutrophil count, CRP, creatinine, albumin and lactate levels should be tested in every hospitalised patient treated for CDI to assess the risk of a fatal outcome.

Establishment of a French surveillance system of Clostridiodes difficile infection: Comparison of patient's characteristics with other national and European data

INTRODUCTION

The magnitude and scope of Clostridioides difficile infection (CDI) has changed with an increase in incidence and severity. The epidemiology of CDI is not well known in France due to difficulties to conduct large continuous surveillance. The objectives were to compare the characteristics of patients with CDI collected through repeated point prevalence survey via DIFTEC™, a free electronic tool, with those from previous French or European studies.

METHODS

DIFTEC™ was developed to evaluate epidemiological burden, diagnostic strategies and management of CDI in France. National and European guidelines were used for definitions. A literature review of studies conducted in Western Europe on CDI and published between January 2008 and May 2018 was done to compare their data with those included in the DIFTEC™ database.

RESULTS

From January 2016, to December 2017, 455 CDI episodes from 22 French hospitals were included. Most of CDI cases were health-care associated (HCA) (78%). The comparison between included patients and French literature data showed that the rates of previous antibiotics exposure, crude mortality and recurrence were not statistically different. However HCA-CDI was significantly more frequent in the DIFTEC™ study. Gender distribution, recurrence and crude mortality rates were not statistically different compared to European data. HCA-CDI was more frequent in the DIFTEC™ study whereas previous treatment with proton pump inhibitors and antibiotics were significantly higher in European studies.

DISCUSSION

These results illustrated the added value of a new tool for increasing the reliable knowledge of CDI in France based on epidemiological surveillance implemented in health-care settings.

Simultaneous detection and ribotyping of Clostridioides difficile, and toxin gene detection directly on fecal samples

Background

Clostridioides difficile is the most common cause of nosocomial diarrhea. Ribotyping of cultured strains by a PCR-based test is used to study potential transmission between patients. We aimed to develop a rapid test that can be applied directly on fecal samples for simultaneous detection and ribotyping of C. difficile, as well as detection of toxin genes.

Methods

We developed a highly specific and sensitive primer set for simultaneous detection and ribotyping of C. difficile directly on total fecal DNA. Toxin genes were detected with primers adapted from Persson et al. (Clin Microbiol Infect 14(11):1057–1064). Our study set comprised 130 fecal samples: 65 samples with positive qPCR for C. difficile toxin A/B genes and 65 C. difficile qPCR negative samples. PCR products were analyzed by capillary gel electrophoresis.

Results

Ribosomal DNA fragment peak profiles and toxin genes were detected in all 65 C. difficile positive fecal samples and in none of the 65 C. difficile negative samples. The 65 samples were assigned to 27 ribotypes by the Dutch reference laboratory. Our peak profiles corresponded to these ribotypes, except for two samples. During a C. difficile outbreak, patients were correctly allocated to the outbreak-cluster based on the results of direct fecal ribotyping, before C. difficile isolates were cultured and conventionally typed.

Conclusion

C. difficile ribotyping directly on fecal DNA is feasible, with sensitivity and specificity comparable to that of diagnostic toxin gene qPCR and with ribotype assignment similar to that obtained by conventional typing on DNA from cultured isolates. This supports simultaneous diagnosis and typing to recognize an outbreak.

Molecular Epidemiology and Antimicrobial Resistance of Clostridioides difficile in Hospitalized Patients From Mexico

Clostridioides difficile is a global public health problem, which is a primary cause of antibiotic-associated diarrhea in humans. The emergence of hypervirulent and antibiotic-resistant strains is associated with the increased incidence and severity of the disease. There are limited studies on genomic characterization of C. difficile in Latin America. We aimed to learn about the molecular epidemiology and antimicrobial resistance in C. difficile strains from adults and children in hospitals of México. We studied 94 C. difficile isolates from seven hospitals in Mexico City from 2014 to 2018. Whole-genome sequencing (WGS) was used to determine the genotype and examine the toxigenic profiles. Susceptibility to antibiotics was determined by E-test. Multilocus sequence typing (MLST) was used to determine allelic profiles. Results identified 20 different sequence types (ST) in the 94 isolates, mostly clade 2 and clade 1. ST1 was predominant in isolates from adult and children. Toxigenic strains comprised 87.2% of the isolates that were combinations of tcdAB and cdtAB (tcdA+/tcdB+/cdtA+/cdtB+, followed by tcdA+/tcdB+/cdtA-/cdtB-, tcdA-/tcdB+/cdtA-/ cdtB-, and tcdA-/tcdB-/cdtA+/cdtB+). Toxin profiles were more diverse in isolates from children. All 94 isolates were susceptible to metronidazole and vancomycin, whereas a considerable number of isolates were resistant to clindamycin, fluroquinolones, rifampicin, meropenem, and linezolid. Multidrug-resistant isolates (≥3 antibiotics) comprised 65% of the isolates. The correlation between resistant genotypes and phenotypes was evaluated by the kappa test. Mutations in rpoB and rpoC showed moderate concordance with resistance to rifampicin and mutations in fusA substantial concordance with fusidic acid resistance. cfrE, a gene recently described in one Mexican isolate, was present in 65% of strains linezolid resistant, all ST1 organisms. WGS is a powerful tool to genotype and characterize virulence and antibiotic susceptibility patterns.

Retrospective Definition of Clostridioides difficile PCR Ribotypes on the Basis of Whole Genome Polymorphisms: A Proof of Principle Study

Clostridioides difficile is a cause of health care-associated infections. The epidemiological study of C. difficile infection (CDI) traditionally involves PCR ribotyping. However, ribotyping will be increasingly replaced by whole genome sequencing (WGS). This implies that WGS types need correlation with classical ribotypes (RTs) in order to perform retrospective clinical studies. Here, we selected genomes of hyper-virulent C. difficile strains of RT001, RT017, RT027, RT078, and RT106 to try and identify new discriminatory markers using in silico ribotyping PCR and De Bruijn graph-based Genome Wide Association Studies (DBGWAS). First, in silico ribotyping PCR was performed using reference primer sequences and 30 C. difficile genomes of the five different RTs identified above. Second, discriminatory genomic markers were sought with DBGWAS using a set of 160 independent C. difficile genomes (14 ribotypes). RT-specific genetic polymorphisms were annotated and validated for their specificity and sensitivity against a larger dataset of 2425 C. difficile genomes covering 132 different RTs. In silico PCR ribotyping was unsuccessful due to non-specific or missing theoretical RT PCR fragments. More successfully, DBGWAS discovered a total of 47 new markers (13 in RT017, 12 in RT078, 9 in RT106, 7 in RT027, and 6 in RT001) with minimum q-values of 0 to 7.40 × 10^-5, indicating excellent marker selectivity. The specificity and sensitivity of individual markers ranged between 0.92 and 1.0 but increased to 1 by combining two markers, hence providing undisputed RT identification based on a single genome sequence. Markers were scattered throughout the C. difficile genome in intra- and intergenic regions. We propose here a set of new genomic polymorphisms that efficiently identify five hyper-virulent RTs utilizing WGS data only. Further studies need to show whether this initial proof-of-principle observation can be extended to all 600 existing RTs.

The largely unnoticed spread of Clostridioides difficile PCR ribotype 027 in Germany after 2010

In recent decades, incidence and severity of Clostridioides difficile infection (CDI) has increased dramatically, coinciding with the emergence of hypervirulent strains such as PCR ribotype 027 (RT027). Data on prevalence of distinct C. difficile strains in random CDI cases in Germany are scarce. The aim of this review was to obtain an overview of prevalence and geographical distribution of RT027 among clinical C. difficile isolates from random cases in non-outbreak settings in hospitals in Germany. For this purpose, we performed a literature review on reported cases of C. difficile RT027 in Germany between 2007 and 2019 in three databases (PubMed, Embase and LIVIVO) and conference proceedings. Studies with selection bias for RT027 (e.g. clinical severity, outbreak reports) were excluded. A total of 304 records were screened, from which 21 were included in this analysis. The nationwide prevalence of RT027 in Germany was <1% prior to 2010 but increased continuously thereafter, reaching 21.7% in 2013. The regional prevalence varied markedly between federal states, higher prevalence was reported from North Rhine-Westphalia (37.4%) and Saxony (31.8%) in 2013-2015. However, data on C. difficile RT027 were not available from almost half of the federal states and were scarce at the national level. Our data suggest a remarkable spread of RT027 in Germany during the past decade, which has remained rather unnoticed so far. A national program for molecular surveillance of C. difficile is required to monitor the changing epidemiology of CDI and to adjust the prevention and control measures.

Clostridioides difficile ribotypes 001 and 126 were predominant in Tehran healthcare settings from 2004 to 2018: a 14-year-long cross-sectional study

Clostridioides difficile infection (CDI) remains a major healthcare problem worldwide, however, little is known about CDI epidemiology in Iran. Between December 2004 and November 2018, 3649 stool samples were collected from patients in 69 hospitals and medical centres in Tehran and were cultured for the presence of C. difficile; isolates were characterized by PCR ribotyping and toxin genes detection. A total of 582 C. difficile isolates were obtained and the overall CDI prevalence was 15.9%; 290 (49.8%) cases were healthcare-associated (HA) and 292 (50.2%) cases were community-associated (CA). Of these, DNA of 513 isolates submitted for ribotyping. The ribotype and/or WEBRIBO type could be assessed in 366 (62.9%) isolates. The most frequent RTs were 001 (n = 75, 12.9%), 126 (n = 65, 11.2%) and 084 (n = 19, 3.3%); the toxin gene profile tcdA + B + /cdtA + B + (n = 112, 19.2%) was the most common. Fifteen C. difficile isolates (2.6%) did not carry any toxin genes. There was no difference between frequently found RTs in HA-CDI and CA-CDI, except for RT 029 which was more likely to be associated with healthcare origin (12/15, p-value = 0.02). No isolate of RTs 027 or 078 was identified. Importantly, RTs 031, 038, 039, 084, 085 reported previously as RTs with an absence of toxin genes, revealed the presence of toxin genes in our study. Using Simpson's reciprocal index of diversity, we found that RT diversity decreased as the prevalence of the RT 084 increased (R = -0.78, p-value = 0.041). Different patterns in CDI epidemiology underscore the importance of local surveillance and infection control measures in Tehran healthcare settings.

An Outbreak of Clostridium (Clostridioides) difficile Infections within an Acute and Long-Term Care Wards Due to Moxifloxacin-Resistant PCR Ribotype 176 Genotyped as PCR Ribotype 027 by a Commercial Assay

We aimed to characterize Clostridioides difficile isolates cultured during a six-month single-center study from stool samples of patients with C. difficile infection (CDI) genotyped by the Xpert^®C. difficile/Epi assay by polymerase chain reaction (PCR) ribotyping, toxin genes’ detection and multi-locus variable number tandem repeats analysis (MLVA). The susceptibility to metronidazole, vancomycin and moxifloxacin was determined by agar dilution. In addition, the presence of Thr82Ile in the GyrA and a single nucleotide deletion at position (Δ117) in the tcdC gene were investigated. Between January 1 and June 30, 2016, of 114 CDIs, 75 cases were genotyped as presumptive PCR ribotype (RT) 027 infections using a commercial assay. C. difficile isolates cultured from presumptive RT027 stool samples belonged to RT176. These isolates carried genes for toxin A (tcdA), B (tcdB), binary (cdtA/B) and had Δ117 in the tcdC gene. Using MLVA, the 71/75 isolates clustered into two clonal complexes (CCs). Of these, 39 isolates (54.9%) were from patients hospitalized in acute care and 32 isolates (45.1%) were isolated from patients hospitalized in the long-term care department. All isolates were susceptible to metronidazole and vancomycin, and 105 isolates were resistant to moxifloxacin (92%) carrying Thr83Ile in the GyrA. An outbreak of RT176 CDIs, suspected as RT027, was recognized in a Slovakian hospital. In order to monitor the emergence and spread of RT027-variants, the identification of a presumptive RT027 CDI should be confirmed at a strain level by PCR ribotyping.

Fidaxomicin versus metronidazole, vancomycin and their combination for initial episode, first recurrence and severe Clostridioides difficile infection - An observational cohort study

PURPOSE

We aimed to evaluate the efficacy of different antibiotic regimens for the treatment of Clostridioides difficile infection (CDI) with regard to the CDI episode number and disease severity.

METHODS

An observation cohort study included 271 CDI patients hospitalised between 2013-2016. Univariate logistic regression was used to evaluate the association between patients' clinical outcome (sustained clinical cure or recurrence) in a 60-day follow-up and the antibiotic regimen used (oral metronidazole, oral vancomycin, combination of oral vancomycin and metronidazole, oral fidaxomicin). Subgroup analyses, based on CDI episode number and severity, were performed.

RESULTS

In the overall population, fidaxomicin was superior to metronidazole, vancomycin or their combination, for a sustained clinical response and in the prevention of recurrent CDI (rCDI). In the subgroup analyses, fidaxomicin was superior to vancomycin or metronidazole for a sustained clinical response and in the prevention of rCDI in the initial episode, first recurrence and non-severe cases. In the oral treatment of severe CDI, fidaxomicin had a similar treatment outcome to vancomycin and none of the antibiotic treatments were superior in the prevention of rCDI. Fidaxomicin, vancomycin, or a combination of metronidazole and vancomycin, had similar outcomes for sustained clinical response and prevention of rCDI in patients with multiple rCDI.

CONCLUSION

Fidaxomicin was superior to metronidazole or vancomycin for the treatment of the initial episode, first recurrence, and non-severe CDI.

Characteristics and predictors of treatment failure with intravenous tigecycline monotherapy among adult patients with severe Clostridioides (Clostridium) difficile infection: a single-centre observational cohort study

Our aim was to analyze characteristics of treatment failure with intravenous tigecycline monotherapy among adults with severe Clostridioides (Clostridium) difficile infection (CDI). A single-centre observational cohort study was performed between 2014 and 2018. Data were collected by charts review, diagnosis and severity were determined by ESCMID guidelines. Primary outcome was treatment failure, secondary outcomes were in-hospital mortality, relapse, colectomy, and complication rates. Independent predictors of failure were identified using logistic regression. Altogether 110 patients were included, failure occurred in 37.3%. Patients with failure frequently had chronic heart and pulmonary co-morbidities, peritonitis, higher CRP levels, ICU admittance rates and need for total parenteral nutrition and vasopressors. Mostly, CDI-specific mortality and complications contributed to failure. Relapse rates were similar. Chronic pulmonary disease, ileus, total parenteral nutrition, and duration of tigecycline therapy were predictors of failure. We conclude that severe CDI cases with higher risk for tigecycline monotherapy failure might be identified by contributing factors.

Antimicrobial resistance in Clostridioides (Clostridium) difficile derived from humans: a systematic review and meta-analysis

BACKGROUND

Clostridioides (Clostridium) difficile is an important pathogen of healthcare- associated diarrhea, however, an increase in the occurrence of C. difficile infection (CDI) outside hospital settings has been reported. The accumulation of antimicrobial resistance in C. difficile can increase the risk of CDI development and/or its spread. The limited number of antimicrobials for the treatment of CDI is matter of some concern.

OBJECTIVES

In order to summarize the data on antimicrobial resistance to C. difficile derived from humans, a systematic review and meta-analysis were performed.

METHODS

We searched five bibliographic databases: (MEDLINE [PubMed], Scopus, Embase, Cochrane Library and Web of Science) for studies that focused on antimicrobial susceptibility testing in C. difficile and were published between 1992 and 2019. The weighted pooled resistance (WPR) for each antimicrobial agent was calculated using a random- effects model.

RESULTS

A total of 111 studies were included. The WPR for metronidazole and vancomycin was 1.0% (95% CI 0-3%) and 1% (95% CI 0-2%) for the breakpoint > 2 mg/L and 0% (95% CI 0%) for breakpoint ≥32 μg/ml. Rifampin and tigecycline had a WPRs of 37.0% (95% CI 18-58%) and 1% (95% CI 0-3%), respectively. The WPRs for the other antimicrobials were as follows: ciprofloxacin 95% (95% CI 85-100%), moxifloxacin 32% (95% CI 25-40%), clindamycin 59% (95% CI 53-65%), amoxicillin/clavulanate 0% (0-0%), piperacillin/tazobactam 0% (0-0%) and ceftriaxone 47% (95% CI 29-65%). Tetracycline had a WPR 20% (95% CI 14-27%) and meropenem showed 0% (95% CI 0-1%); resistance to fidaxomicin was reported in one isolate (0.08%).

CONCLUSION

Resistance to metronidazole, vancomycin, fidaxomicin, meropenem and piperacillin/tazobactam is reported rarely. From the alternative CDI drug treatments, tigecycline had a lower resistance rate than rifampin. The high-risk antimicrobials for CDI development showed a high level of resistance, the highest was seen in the second generation of fluoroquinolones and clindamycin; amoxicillin/clavulanate showed almost no resistance. Tetracycline resistance was present in one fifth of human clinical C. difficile isolates.

Evaluation of glutamate dehydrogenase (GDH) and toxin A/B rapid tests for Clostridioides (prev. Clostridium) difficile diagnosis in a university hospital in Minas Gerais, Brazil

Clostridioides (Clostridium) difficile is responsible for most cases of nosocomial diarrhea and, despite the high prevalence of the disease worldwide, the best laboratory diagnostic approach to diagnose C. difficile infection (CDI) is a subject of ongoing debate. Although the use of multiple tests is recommended, the cost of these algorithms commonly exceeds the affordability in some countries. Thus, to improve CDI diagnosis in a university hospital in Brazil, this study analyzed two immunochromatographic tests and one enzyme immunoassay (ELISA) to evaluate the detection of glutamate dehydrogenase (GDH) and A/B toxins of C. difficile. Stool samples of 89 adult patients presenting nosocomial diarrhea during hospitalization were included. The toxigenic culture was used as the reference method. GDH detection by both commercial tests showed high sensitivity (100%) and specificity (92.1%). On the other hand, toxin-based methods showed a sensitivity between 19.2 and 57.7%. In conclusion, the results suggest that rapid tests for GDH detection are not only suitable for CDI diagnosis as screening tests but also as a single method.

COVID-19 and Clostridioides difficile infection (CDI): Possible implications for elderly patients

COVID-19 dramatically affects the elderly. Due to the large usage of antibiotics during the current pandemic and the gastrointestinal manifestations of COVID-19, the elderly population, hospitalized patients, residents in LTCFs and persons that survived the COVID-19 might be more prone to Clostridioides difficile infections (CDI). A renewed attention to CDI is necessary during the ongoing COVID-19 pandemic.

The association of a reduced susceptibility to moxifloxacin in causative Clostridium (Clostridioides) difficile strain with the clinical outcome of patients

OBJECTIVES

To investigate the relationship between Clostridium (Clostridioides) difficile strain characteristics and C. difficile infection (CDI) outcome.

METHODS

Between October and December 2017, 16 hospitals collected epidemiological data according to the European Centre for Disease Prevention and Control (ECDC) surveillance protocol for CDI. C. difficile isolates were characterized by ribotyping, toxin genes detection and antibiotic susceptibility testing to metronidazole, vancomycin and moxifloxacin.

RESULTS

The overall mean CDI incidence density was 4.5 [95% CI 3.6-5.3] cases per 10,000 patient-days. From the 433 CDI cases, 330 (76.2%) were healthcare-associated, 52 (12.0%) cases were community-associated or of unknown origin and 51 (11.8%) CDI cases recurrent; a complicated course of CDI was reported in 65 cases (15.0%). Eighty-eight (20.3%) of patients died and 59 of them within 30 days after the CDI diagnosis. From the 379 C. difficile isolates, the most prevalent PCR ribotypes were 001 (n = 127, 33.5%) and 176 (n = 44, 11.6%). A total of 186 (49.1%) isolates showed a reduced susceptibility to moxifloxacin (> 4 mg/L) and 96.4% of them had Thr82Ile in the GyrA. Nineteen isolates revealed reduced susceptibility to metronidazole and two isolates to vancomycin (> 2 mg/L). A fatal outcome was associated with a reduced susceptibility to moxifloxacin, the advanced age of the patients and a complicated course of CDI (p<0.05). No association between ribotype, binary toxin and a reduced susceptibility to moxifloxacin and complicated course or recurrent CDI was found.

CONCLUSIONS

A reduced susceptibility to moxifloxacin, in causative C. difficile strains was associated with fatal outcome of the patients, therefore it is an important marker in surveillance of CDI.

The Colonisation of Calves in Czech Large-Scale Dairy Farms by Clonally-Related Clostridioides difficile of the Sequence Type 11 Represented by Ribotypes 033 and 126

To investigate a possible Clostridioides difficile reservoir in the Czech Republic, we performed a study in 297 calves from 29 large-scale dairy farms. After enrichment, faecal samples were inoculated onto selective agar for C. difficile. From the 297 samples, 44 C. difficile isolates were cultured (prevalence of 14.8%, 10 farms). The Holstein breed and use of digestate were associated with C. difficile colonisation (p ˂ 0.05). C. difficile isolates belonged to the ribotype/sequence type: RT033/ST11 (n = 37), RT126/ST11 (n = 6) and RT046/ST35 (n = 1). A multiple-locus variable-number tandem-repeat analysis revealed four clonal complexes of RT033 isolates and one clonal complex of RT126 isolates. All isolates were sensitive to amoxicillin, metronidazole and vancomycin. Forty isolates were resistant to ciprofloxacin, twenty-one to clindamycin, seven to erythromycin, seven to tetracycline and six to moxifloxacin. Moxifloxacin resistant isolates revealed an amino-acid substitution Thr82Ile in the GyrA. In conclusion, the calves of Holstein breed from farms using digestate as a product of bio-gas plants are more likely to be colonised by clonally-related C. difficile of ST 11 represented by ribotypes 033 and 126. The identified resistance to moxifloxacin with a Thr82Ile substitution in the GyrA highlights the need for further monitoring by the "One health approach".

Diagnosing Clostridioides difficile infections with molecular diagnostics: multicenter evaluation of revogene C. difficile assay

Clostridioides difficile infections are a significant threat to our healthcare system, and rapid and accurate diagnostics are crucial to implement the necessary infection prevention and control measurements. Nucleic acid amplification tests are such reliable diagnostic tools for the detection of toxigenic Clostridioides difficile strains directly from stool specimens. In this multicenter evaluation, we determined the performance of the revogene C. difficile assay. The analysis was conducted on prospective stool specimens collected from six different sites in Europe. The performance of the revogene C. difficile assay was compared to the different routine diagnostic methods and, for a subset of the specimens, against toxigenic culture. In total, 2621 valid stool specimens were tested, and the revogene C. difficile assay displayed a sensitivity/specificity of 97.1% [93.3-99.0] and 98.9% [98.5-99.3] for identification of Clostridioides difficile infection. Discrepancy analysis using additional methods improved this performance to 98.8% [95.8-99.9] and 99.6% [99.2-99.8], respectively. In comparison to toxigenic culture, the revogene C. difficile assay displayed a sensitivity/specificity of 93.0% [86.1-97.1] and 99.5% [98.7-99.9], respectively. These results indicate that the revogene C. difficile assay is a robust and reliable aid in the diagnosis of Clostridioides difficile infections.

Clostridium difficile Infection Epidemiology over a Period of 8 Years—A Single Centre Study

Clostridium difficile infection (CDI) is the most common infectious disease related to antibiotic-associated diarrhoea and is a current leading cause of morbidity/mortality, with substantial consequences for healthcare services and overall public health. Thus, we performed a retrospective epidemiological study of CDI for a long period (8 years), in an infectious hospital located in north-western Romania, which serves an entire county of the country (617,827 inhabitants). From 2011 to 2018, 877 patients were diagnosed with CDI; the mean incidence of this disease was 2.76 cases/10,000 patient-days, with an increasing trend in the annual incidence until 2016, at which point there was a decrease. The most commonly afflicted were patients in the 75–84 age group, observed in winter and spring. The results show that the antibiotics were administered in 679 (77.42%) subjects, within the last 3 months before CDI, statistically significant more than proton-pump inhibitors (PPIs)—128 (14.60%) and antidepressant medications—60 (6.84%), which were administered during the same period (p < 0.001). No medication was reported in 10 (6.84%) cases of CDI, in the last 3 months of the study. The fatality rate attained 4.1%, tripling in 2018 vs. 2011. CDI became a significant public health conundrum that can, nevertheless, be combatted through a judicious use of antibiotics.

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.

Characteristics of Clostridium difficile isolates and the burden of hospital-acquired Clostridium difficile infection in a tertiary teaching hospital in Chongqing, Southwest China

BACKGROUND

Clostridium difficile infection (CDI), especially hospital-acquired Clostridium difficile infection (HA-CDI), continues to be a public health problem and has aroused great concern worldwide for years. This study aimed to elucidate the clinical and epidemiological features of HA-CDI and the characteristics of C.difficile isolates in Chongqing, Southwest China.

METHODS

A case-control study was performed to identify the clinical incidence and risk factors of HA-CDI. C. difficile isolates were characterised by polymerase chain reaction (PCR) ribotyping, multilocus sequence typing (MLST), toxin gene detection and antimicrobial susceptibility testing.

RESULTS

Of the 175 suspicious patients, a total of 122 patients with antibiotic-associated diarrhea (AAD) were included in the study; among them, 38 had HA-CDI. The incidence of AAD and HA-CDI was 0.58 and 0.18 per 1000 patient admissions, respectively. Chronic renal disease and cephalosporin use were independent risk factors for HA-CDI. Fifty-five strains were assigned into 16 sequence types (STs) and 15 ribotypes (RTs). ST2/RT449 (8, 14.5%) was the predominant genotype. Of the 38 toxigenic isolates, A + B + CDT- isolates accounted for most (34, 89.5%) and 1 A + B + CDT+ isolate emerged. No isolate was resistant to vancomycin, metronidazole or tigecycline, with A-B-CDT- being more resistant than A + B + CDT-.

CONCLUSIONS

Different genotypes of C. difficile strains were witnessed in Chongqing, which hinted at the necessary surveillance of HA-CDI. Adequate awareness of patients at high risk of HA-CDI acquisition is advocated and cautious adoption of cephalosporins should be highlighted.

Comparing the epidemiology of community- and hospital-associated Clostridium difficile infections in Northern Ireland, 2012-2016: a population data linkage and case-case study

The burden of community-associated Clostridium difficile infection (CA-CDI) has increased. We aimed to describe the epidemiology of CA-CDI to inform future interventions. We used population-based linked surveillance data from 2012 to 2016 to describe socio-demographic factors, ribotype and mortality for all CA (n = 1303) and hospital-associated (HA, n = 1356) CDI. For 483 community-onset (CO) CA-CDI and 287 COHA-CDI cases, a questionnaire on risk factors was completed and we conducted a case-case study using logistic regression models for univariate and multivariable analysis. CA-CDI cases had lower odds of being male (adjusted odds ratio (AOR) 0.71, 95% confidence interval (CI) 0.58-0.87; P &lt; 0.001), and higher odds of living in rural rather than urban settlement (AOR 1.5, 95% CI 1.1-2.1; P = 0.05) compared with HA-CDI cases. The distribution of ribotypes was similar in both groups with RT078 being most prevalent. CDI-specific death was lower in CA-CDI than HA-CDI (7% vs. 11%, P &lt; 0.001). COCA-CDI had lower odds of having had an outpatient appointment in the previous 4 weeks compared with COHA-CDI (AOR 0.61; 95% CI 0.41-0.9, P = 0.01) and lower odds of being in a care home or hospice when compared with their own home, than COHA-CDI (AOR 0.66; 95% CI 0.45-0.98 and AOR 0.35; 95% CI 0.13-0.92, P = 0.02). Exposure to gastric acid suppressants (50% in COCA-CDI and 55% in COHA-CDI) and antimicrobial therapy (18% in COCA-CDI and 20% in COHA-CDI) prior to CDI was similar. Our analysis of community-onset cases suggests that other risk factors for COHA-CDI may be equally important for COCA-CDI. Opportunities to safely reduce antibiotic and gastric acid suppressants use should be investigated in all healthcare settings.