Clinical epidemiology of Clostridium difficile infection among hospitalized patients with antibiotic-associated diarrhea in a university hospital of Brazil

Toxin genotypes, antibiotic resistance and their correlations in Clostridioides difficile isolated from hospitals in Xi'an, China

BACKGROUND

Clostridioides difficile is the main pathogen of antimicrobial-associated diarrhoea and health care facility-associated infectious diarrhoea. This study aimed to investigate the prevalence, toxin genotypes, and antibiotic resistance of C. difficile among hospitalized patients in Xi'an, China.

RESULTS

We isolated and cultured 156 strains of C. difficile, representing 12.67% of the 1231 inpatient stool samples collected. Among the isolates, tcdA + B + strains were predominant, accounting for 78.2% (122/156), followed by 27 tcdA-B + strains (27/156, 17.3%) and 6 binary toxin gene-positive strains. The positive rates of three regulatory genes, tcdC, tcdR, and tcdE, were 89.1% (139/156), 96.8% (151/156), and 100%, respectively. All isolates were sensitive to metronidazole, and the resistance rates to clindamycin and cephalosporins were also high. Six strains were found to be resistant to vancomycin.

CONCLUSION

Currently, the prevalence rate of C. difficile infection (CDI) in Xi'an is 12.67% (156/1231), with the major toxin genotype of the isolates being tcdA + tcdB + cdtA-/B-. Metronidazole and vancomycin were still effective drugs for the treatment of CDI, but we should pay attention to antibiotic management and epidemiological surveillance of CDI.

Bacterial microbiome changes after fecal transplantation for recurrent Clostridioides difficile infection in the Brazilian center

Clostridioides difficile infection (CDI) poses a significant global health threat owing to its substantial morbidity and associated healthcare costs. A key challenge in controlling CDI is the risk of multiple recurrences, which can affect up to 30% of patients. In such instances, fecal microbiota transplantation (FMT) is increasingly recognized as the optimal treatment. However, few related studies have been conducted in developing countries, and the microbiota composition of Brazilian patients and its dynamic modification post-FMT remain largely unexplored. This study aimed to evaluate the changes in the bacterial gut microbiome in Brazilian patients with recurrent CDI post-FMT. Ten patients underwent FMT, and the primary and overall CDI resolution rates were 80% and 90% after the first and second FMT, respectively. FMT was associated with an early increase in Shannon's diversity, evident as soon as 1 week post-FMT and persisting for at least 25 days post-treatment. Post-treatment, the abundance of Firmicutes increased and that of Proteobacteria decreased. Specifically, the abundance of the genera Ruminococcus, Faecalibacterium, Lachnospira, and Roseburia of the Firmicutes phylum was significantly higher 1 week post-transplantation, with Ruminococcus and Faecalibacterium remaining enriched 25 days post-transplantation. This study is the first of its kind in Brazil to evaluate the microbiota of a donor and patients undergoing FMT. Our findings suggest that FMT can induce remarkable changes in the gut microbiota, characterized by an early and sustained increase in diversity lasting at least 25 days. FMT also promotes enrichment of genera such as Ruminococcus spp., Faecalibacterium spp., and Roseburia spp., essential for therapeutic success.

Prevalence of Clostridioides difficile in dogs (Canis familiaris) with gastrointestinal disorders in Rio de Janeiro

Clostridioides difficile infections (CDI) have a high morbidity and mortality rate and have always been considered a nosocomial disease. Nonetheless, the number of cases of community-acquired CDI is increasing, and new evidence suggests additional C. difficile reservoirs exist. Pathogenic C. difficile strains have been found in livestock, domestic animals, and meat, so a zoonotic transmission has been proposed.

OBJECTIVE

The goal of this study was to isolate C. difficile strains in dogs at a veterinary clinic in Rio de Janeiro, Brazil, and characterize clinical and pathological findings associated with lower gastrointestinal tract disorders.

METHODS

Fifty stool samples and biopsy fragments from dogs were obtained and cultured in the CDBA selective medium. All suggestive C. difficile colonies were confirmed by MALDI-TOF MS and PCR (tpi gene). Vancomycin, metronidazole, moxifloxacin, erythromycin, and rifampicin were tested for antibiotic susceptibility. Biofilm, motility assays, and a PCR for the toxins (tcdA, tcdB, and cdtB), as well as ribotyping, were also performed.

RESULTS

Blood samples and colonic biopsy fragments were examined in C. difficile positive dogs. Ten animals (20%) tested positive for C. difficile by using stool samples, but not from biopsy fragments. Most C. difficile strains were toxigenic: six were A+B+ belonging to RT106; two were A+B+ belonging to RT014/020; and two were A-B- belonging to RT010. All strains were biofilm producers. In the motility test, 40% of strains were as motile as the positive control, CD630 (RT012). In the disc diffusion test, two strains (RT010) were resistant to erythromycin and metronidazole; and another to metronidazole (RT014/020). In terms of C. difficile clinicopathological correlations, no statistically significant morphological changes, such as pseudomembranous and "volcano" lesions, were observed. Regarding hematological data, dogs positive for C. difficile had leucopenia (p = 0.02) and lymphopenia (p = 0.03). There was a significant correlation between senility and the presence of C. difficile in the dogs studied (p = 0,02).

CONCLUSIONS

Although C. difficile has not been linked to canine diarrheal disorders, it appears to be more common in dogs with intestinal dysfunctions. The isolation of ribotypes frequently involved in human CDI outbreaks around the world supports the theory of C. difficile zoonotic transmission.

CLINICAL OUTCOME AND SEVERITY OF CLOSTRIDIOIDES (CLOSTRIDIUM) DIFFICILE INFECTION AT A TERTIARY REFERRAL HOSPITAL IN BRAZIL

•The outcomes of CDI were evaluated in 65 patients with CDI in a Brazilian tertiary hospital. •Lack of clinical improvement after treatment and the severity score (ATLAS) increased the risk of death. •The use of multiple antimicrobial agents was associated with longer hospital stays. •Patients with high Charlson comorbidity index (>7) were more likely to recur. Background - Clostridioides difficile infection (CDI) is a potentially severe disease that can present with refractoriness, recurrence, and evolution to death. In Brazil, the epidemiology of CDI seems to differ from that of the United States and most European countries, with only one ribotype (RT) 027-related case and a high prevalence of RT106. Objective - The aim of this study was to evaluate the outcomes of CDI and its possible association with ribotypes at a university hospital in Brazil. Methods - A total of 65 patients with CDI were included and stool samples were submitted to A/B toxin detection and toxigenic culture, and toxigenic isolates (n=44) were also PCR ribotyped. Results - Patients' median age was 59 (20-87) years and there were 16 (24.6%) deaths. The median Charlson comorbidity index (CCI) was 4 (0-15) and 16.9% of the patients had CCI ≥8. The ATLAS score and non-improvement of diarrhea were related to higher mortality. A longer length of hospitalization was related to the enteral nutrition and use of multiple antibiotics. The period between CDI diagnosis and hospital discharge was longer in those who received new antibiotics after diagnosis, multiple antibiotics, and required intensive care treatment. Recurrence was associated with CCI >7. Twenty ribotypes were identified and RT106 was the most frequently detected strain (43.2%). No relationship was observed between the ribotypes and outcomes. CDI was present in patients with more comorbidities. Conclusion - Risk factors for higher mortality, longer hospital stay and recurrence were identified. A diversity of ribotypes was observed and C. difficile strains were not related to the outcomes.

Evaluation of disk diffusion method for testing the rifampicin, erythromycin, and tetracycline susceptibility of Clostridioides (prev. Clostridium) difficile

INTRODUCTION

Antimicrobial resistance (AMR) is one of the greatest threats to animal and public health. Clostridioides (prev. Clostridium) difficile is a major burden to healthcare and a relevant AMR gene reservoir. Despite the known importance of AMR in C. difficile epidemiology and treatment, antimicrobial susceptibility testing for this pathogen is still based on the determination of the minimal inhibitory concentration (MIC) by the agar dilution method, which is technically demanding and labor-intensive. In this study, the disk diffusion method was used to evaluate the susceptibility of C. difficile to erythromycin, rifampicin, and tetracycline.

MATERIAL AND METHODS

A total of 155 isolates isolated between 2011 and 2022 from humans and animals in Brazil were simultaneously tested using the disk diffusion method and the epsilometer test (Etest) for these three antimicrobials on Brucella blood agar supplemented with vitamin K and hemin.

RESULTS

The results suggest that disk diffusion can be an interesting routine tool to identify erythromycin- and rifampicin-resistant C. difficile isolates (≥20 mm cut-off) and wild type (WT) strains (≥28 mm). However, the disk diffusion protocol tested in this study does not seem suitable for tetracycline because of the common misclassification of resistant strains.

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.

Metronidazole for Treatment of Clostridioides difficile Infections in Brazil: A Single-Center Experience and Risk Factors for Mortality

We describe the epidemiology of C. difficile infections (CDIs) focused on treatment and analyze the risk factors for mortality. This is a retrospective cohort study of CDI cases with a positive A/B toxin in the stool in 2017–2018. We analyzed the demographic data, comorbidities, previous use of antimicrobials, severity, and treatment, and we performed multivariate analysis to predict the 30-days mortality. We analyzed 84 patients, 37 (44%) of which were male, where the mean age was 68.1 years and 83 (99%) had comorbidities. The percentage of positivity of the A/B toxin was 11.6%, and the overall incidence density was 1.78/10,000 patient days. Among the patients, 65.4% had previous use of antimicrobials, with third-generation cephalosporins being the class most prescribed, and 22.6% of cases were severe. Treatment was prescribed for 70 (83.3%) patients, and there was no statistically significant difference between the initial treatment with metronidazole and vancomycin even in severe cases. The 30-day mortality was 7/84 (8.3%), and the risk factors associated with mortality was a severity score ≥2 (OR: 6.0; CI: 1.15–31.1; p = 0.03). In this cohort of CDI-affected patients with comorbidities and cancer, metronidazole was shown to be a good option for treating CDIs, and the severity score was the only independent risk factor for death.

Characterization of the virulence of three novel clade 2 Clostridioides (Clostridium) difficile strains and a two-year screening in animals and humans in Brazil

Clostridioides (Clostridium) difficile infection (CDI) is an evolving global healthcare problem, and owing to the diverse and dynamic molecular epidemiology of C. difficile, new strains continue to emerge. In Brazil, only two cases of CDI due to the so called hypervirulent PCR ribotype (RT) 027 belonging to clade 2 have ever been reported, whereas incidence of CDI due to another “hypervirulent” RT078 (clade 5) has not yet been reported. In contrast, novel clade 2 strains have been identified in different hospitals. To better understand the epidemiology of CDIs in Brazil, this study aimed to genotypically and phenotypically characterize three novel Brazilian clade 2 strains (RT883, 884, and 885) isolated from patients with confirmed CDI. In addition, to better understand the circulating RTs, a two-year sampling was conducted in patients from the same hospital and in several domestic and wild animal species. The three strains examined showed lower production of A/B toxins than the control RT027, although two of these strains harbored a truncated tcdC gene. All strains showed swimming motility similar to that of RT027, while RT883 showed higher spore production than the reference strain. In the in vivo hamster model, the lethality of all strains was found to be similar to that of RT027. Both cgMLST and cgMLSA analyses revealed a high genetic similarity among the three-novel clade 2 isolates. In the two-year survey in animals and humans, RT883, 884, and 885 were not detected; however, three new RTs (RT988, RT989, and RT990) were isolated, two of which were genetically related to the three previously reported clade 2 strains. RT106 and RT126 were most frequently detected in humans (47.9%) and animals (57.9%), respectively. Furthermore, RT027 and RT078 were not detected in humans. The results of this study suggest that these novel clade 2 strains have virulence potential and that new strains from clade 2 continue to emerge in our setting, indicating the need for long-term local surveillance.

Predictive factors, outcomes, and molecular epidemiology of Clostridioides difficile diarrhea in Brazilian hospitals

Little is known about the role of lineage of strains of Clostridioides difficile (CD) on the clinical presentation of CD infection (CDI) in Latin America, especially regarding the treatment response. We conducted a multicenter, prospective study to investigate the predictive factors and treatment outcomes of CDI in hospitalized patients and to performed phenotypical and molecular characterization of CD strains. A total of 361 diarrheic patients at 5 hospitals from different regions of the country were enrolled. All stool samples were tested for glutamate dehydrogenase (GDH), toxins A and B, and toxin genes using a nucleic acid amplification test (NAAT). Specimens were cultured and susceptibility profile and whole-genome sequencing (WGS) were performed. CDI positivity was 15% (56/377). Predictive factors for CDI were prior use of meropenem (OR 4.09, 95% CI 2.097-7.095; p<0.001), mucus in stools (OR 3.29; 95% CI 1.406-7.722; p=0.006) and neutrophil left-shift with >20% of bands (OR 3.77; 95% IC 1.280-11.120; p=0.016). Overall mortality was 19%, with no deaths attributed to CDI. Oral metronidazole was used in 74% of cases, with 85% of cure and 14% of recurrence. A total of 35 CD isolates were recovered, all of them susceptible to metronidazole and vancomycin. The WGS revealed 17 different STs, six of which were novel. ST42 was the most common ST and hypervirulent strains were not found. Severe CDI were caused by ST42, ST5, ST8, ST48, ST33 and a novel ST667. The ermB gene was more frequently found in isolates of ST42 (p=0.004).

Assessing risk factors, mortality, and healthcare utilization associated with Clostridioides difficile infection in four Latin American countries

Background

Clostridioides difficile infection (CDI) is the most common cause of healthcare-associated infections in Western countries. Risk factors, mortality, and healthcare utilization for CDI in Latin America are poorly understood. This study assessed risk factors and burden associated with nosocomial CDI in four Latin American countries.

Methods

This retrospective, case-control study used databases and medical records from 8 hospitals in Argentina, Brazil, Chile, and Mexico to identify nosocomial CDI cases from 2014 − 2017. Cases were patients aged ≥18 years with diarrhea and a positive CDI test ≥72 h after hospital admission. Two controls (without diarrhea; length of hospital stay [LOS] ≥3 days; admitted ±14 days from case patient; shared same ward) were matched to each case. CDI-associated risk factors were assessed by univariate and multivariable analyses. CDI burden (LOS, in-hospital mortality) was compared between cases and controls.

Results

The study included 481 cases and 962 controls. Mean age and sex were similar between cases and controls, but mean Charlson comorbidity index (4.3 vs 3.6; p < 0.001) and recent hospital admission (35.3% vs 18.8%; p < 0.001) were higher among cases. By multivariable analyses, CDI risk was associated with prior hospital admission within 3 months (odds ratio [OR], 2.08; 95% CI: 1.45, 2.97), recent antibiotic use (ie, carbapenem; OR, 2.85; 95% CI: 1.75, 4.64), acid suppressive therapy use (OR, 1.71; 95% CI: 1.14, 2.58), and medical conditions (ie, renal disease; OR, 1.48; 95% CI: 1.19, 1.85). In-hospital mortality rate (18.7% vs 6.9%; p < 0.001) and mean overall LOS (33.5 vs 18.8 days; p < 0.001) were higher and longer, respectively, in cases versus controls.

Conclusion

Antibiotic exposure, preexisting medical conditions, and recent hospital admission were major risk factors for CDI in Argentina, Brazil, Chile, and Mexico. CDI was associated with increased in-hospital risk of death and longer LOS. These findings are consistent with published literature in Western countries.

Addressing antimicrobial resistance in Nigerian hospitals: exploring physicians prescribing behavior, knowledge, and perception of antimicrobial resistance and stewardship programs

INTRODUCTION

We assessed the knowledge of, attitude toward antimicrobial resistance (AMR) and practice of antimicrobial stewardship (AMS) among physicians in Nigeria to provide future guidance to the Nigerian National Action Plan for AMR.

METHODS

A descriptive cross-sectional questionnaire-based study explored the physicians' self-reported practice of antibiotic prescribing, knowledge, attitude, and practice of AMR and components of ASPs.

RESULTS

The majority (217; 67.2%) of respondents prescribed antibiotics daily in their clinical practice AMR was recognized as a global and local problem by 308 (95.4%) and 262 (81.1%) respondents, respectively. Only 91 (28.2%) of respondents have ever heard of antibiotic stewardship. The median AMR knowledge score was 40 (19-45)out of 45while that for ASP was 46.0(32-57) out of 60. There was significant statistical difference between the ASP median scores among the medical specialties category (P value <0.0001) More respondents had good knowledge of AMR than ASPs (82.7% versus 36.5%; p < 0.0001).

CONCLUSION

Respondents in this study were more knowledgeable about AMR than AMS and its core components.

STRUCTURING A FECAL MICROBIOTA TRANSPLANTATION CENTER IN A UNIVERSITY HOSPITAL IN BRAZIL

BACKGROUND

Fecal microbiota transplantation (FMT) is an important therapeutic option for recurrent or refractory Clostridioides difficile infection, being a safe and effective method. Initial results suggest that FMT also plays an important role in other conditions whose pathogenesis involves alteration of the intestinal microbiota. However, its systematized use is not widespread, especially in Brazil. In the last decade, multiple reports and several cases emerged using different protocols for FMT, without standardization of methods and with variable response rates. In Brazil, few isolated cases of FMT have been reported without the implantation of a Fecal Microbiota Transplantation Center (FMTC).

OBJECTIVE

The main objective of this study is to describe the process of implanting a FMTC with a stool bank, in a Brazilian university hospital for treatment of recurrent and refractory C. difficile infection.

METHODS

The center was structured within the criteria required by international organizations such as the Food and Drug Administration, the European Fecal Microbiota Transplant Group and in line with national epidemiological and regulatory aspects.

RESULTS

A whole platform involved in structuring a transplant center with stool bank was established. The criteria for donor selection, processing and storage of samples, handling of recipients before and after the procedure, routes of administration, short and long-term follow-up of transplant patients were determined. Donor selection was conducted in three stages: pre-screening, clinical evaluation and laboratory screening. Most of the candidates were excluded in the first (75.4%) and second stage (72.7%). The main clinical exclusion criteria were: recent acute diarrhea, overweight (body mass index ≥25 kg/m2) and chronic gastrointestinal disorders. Four of the 134 candidates were selected after full screening, with a donor detection rate of 3%.

CONCLUSION

The implantation of a transplant center, unprecedented in our country, allows the access of patients with recurrent or refractory C. difficile infection to innovative, safe treatment, with a high success rate and little available in Brazil. Proper selection of qualified donors is vital in the process of implementing a FMTC. The rigorous clinical evaluation of donors allowed the rational use of resources. A transplant center enables treatment on demand, on a larger scale, less personalized, with more security and traceability. This protocol provides subsidies for conducting FMT in emerging countries.

Multicenter study of the epidemiology of Clostridioides difficile infection and recurrence in southern Brazil

Clostridioides (Clostridium) difficile is the main etiology underlying antibiotic-associated diarrhea (AAD). Still, few Brazilian data are available on this infection. The aims of this multicenter study were to identify the prevalence, clinical characteristics, and outcomes of C. difficile infection (CDI) in patients with antibiotic associated diarrhea at eight hospitals in Curitiba, southern Brazil, during the years 2017-2019. Stool samples were tested using enzyme immunoassay for glutamate dehydrogenase antigen (GDH) and A/B toxins. Positive GDH samples were further evaluated by real-time polymerase chain reaction (PCR) for the presence of genes encoding toxin B (tcdB), binary toxin (cdt), and marker of hypervirulent C. difficile strain (tcdC deletion). The prevalence of CDI in 351 patients with AAD included in the study was 17.7% (n = 62). Among the CDI cases, tcdB was positive in all 62 stool samples, while cdt was positive in 10 samples, and tcdC deletion was positive in only two. Carriage of carbapenem-resistant Gram-negative bacilli, previous hospitalization, and use of broad-spectrum cephalosporin and carbapenem were associated with CDI. Among patients with CDI, 64.5% presented with severe diarrhea, and 8% (5/62) progressed with colitis and required intensive care. The 30-day mortality was 24% (15/62), and the CDI-associated mortality was 4.8% (3/62). Overall, 83.8% (52/62) of the patients achieved primary cure, and 20.8% of the evaluated patients (10/48) presented CDI recurrence. The treatment administered was not significantly associated with the 60-day recurrence or mortality. In conclusion, we reported in this study data of prevalence and recurrence rates of CDI in patients with AAD and evaluated the number of severe cases and infection-related mortality, which were up to now unknown in Southern Brazilian hospitals.

Clostridioides difficile ribotype 106: A systematic review of the antimicrobial susceptibility, genetics, and clinical outcomes of this common worldwide strain

Clostridioides difficile typing is invaluable for the investigation of both institution-specific outbreaks as well as national surveillance. While the epidemic ribotype 027 (RT027) has received a significant amount of resources and attention, ribotype 106 (RT106) has become more prevalent throughout the past decade. The purpose of this systematic review was to comprehensively summarize the genetic determinants, antimicrobial susceptibility, epidemiology, and clinical outcomes of infection caused by RT106. A total of 68 articles published between 1999 and 2019 were identified as relevant to this review. Although initially identified in the United Kingdom in 1999, RT106 is now found worldwide and became the most prevalent strain in the United States in 2016. Current data indicate that RT106 harbors the tcdA and tcdB genes, lacks binary toxin genes, and does not contain any deletions in the tcdC gene, which differentiates it from other epidemic strains, including ribotypes 027 and 078. Interestingly, RT106 produces more spores than other strains, including RT027. Overall, RT106 is highly resistant to erythromycin, clindamycin, fluoroquinolones, and third-generation cephalosporins. However, the MIC90 in most studies are one to two fold dilutions below the epidemiologic cut-off values of metronidazole and vancomycin, suggesting both are acceptable treatment options from an in vitro perspective. The few clinical outcomes studies available concluded that RT106 causes less severe disease than RT027, but patients were significantly more likely to experience multiple CDI relapses when infected with a RT106 strain. Specific areas warranting future study include potential survival advantages provided by genetic elements as well as a more robust investigation of clinical outcomes associated with RT106.

Isolation of Clostridium perfringens and Clostridioides difficile in diarrheic and nondiarrheic cats

The occurrence and characteristics of Clostridioides (previously Clostridium) difficile and Clostridium perfringens in the feces of diarrheic and non-diarrheic cats was investigated. Apparently healthy animals were more likely to be positive for C. perfringens type A (p = 0.009). Two isolates (0.7%), one each from a diarrheic and an apparently healthy cat, were positive for the enterotoxin-encoding gene but negative for the NetF-encoding gene. Six toxigenic C. difficile isolates were isolated, all RT106 and ST42, which is commonly reported in humans with C. difficile infection.

Surveillance of antimicrobial susceptibilities reveals high proportions of multidrug resistance in toxigenic Clostridium difficile strains in different areas of Poland

Two hundred and fifty-three non-duplicate toxigenic Clostridium difficile isolates, collected from February 2012 to December 2014, were evaluated for phenotypic resistance to ten antimicrobial drugs with the E-test gradient diffusion method. All strains of C. difficile were susceptible to metronidazole, vancomycin, and tigecycline. The metronidazole MIC values of the hyperepidemic PCR-ribotypes RT027 and RT176 were higher than those of non-epidemic PCR-ribotypes (p < 0.05, as evidenced by Mann-Whitney U test). In contrast, vancomycin susceptibility did not differ between hyperepidemic and non-epidemic strains, although the difference was almost significant (p = 0.065). Clostridium difficile RT027 and RT176 isolates could be assessed to five and four different susceptibility patterns, respectively, representing various combinations of resistance to different antimicrobial classes. A single point mutation (Thr82Ile) in the gyrA gene was detected in 11 (78.6%) of 14 isolates with high level of resistance to ciprofloxacin and moxifloxacin and four different types of single point mutations (Arg447Lys, Ser416Ala, Asp426Val, Asp426Asn) in the gyrB gene were detected in 4 strains, also with high level of resistance to ciprofloxacin and moxifloxacin. Four different point mutations were detected in the rpoB gene in 21 rifampicin-resistant strains of which one has not been reported previously, Gln489Leu. This study demonstrates the presence of multidrug-resistant C. difficile strains in Polish hospitals over the study period, irrespective of geographical location or reference level of the hospital.