The epidemiology of Clostridioides difficile infection in Brazil: A systematic review covering thirty years

Molecular detection of toxigenic Clostridioides difficile in subgingival biofilm of severe periodontitis

OBJECTIVES

The oral cavity is the main gateway for the entry of C. difficile spores to the digestive tract. In conditions of poor oral hygiene and periodontal diseases, the dysbiotic oral microbiota may be a reservoir for several human pathogens. Here, we explored the prevalence of C. difficile in the oral microbiota of patients with severe periodontitis by the molecular detection of species specific genes.

METHODS

Subgingival biofilm, saliva and/or feces from 659 patients with gingivitis, periodontitis and no periodontal diseases were screened for the tpi and toxin A/B genes specific for C. difficile by multiplex PCR. Differences among groups were sought by the Chi-square test.

RESULTS

The overall frequency of C. difficile tpi gene was 29 %, with a high detection of tcdB gene (44.8 %). Patients with periodontitis showed a greater prevalence of this gene in the biofilm than individuals with gingivitis and periodontal health (p = 0.001), particularly at more severe stages of disease (p < 0.05). No toxin genes were detected in feces or biofilm from healthy patients, whereas >70 % of the biofilm from patients with periodontal diseases were positive for these genes (p < 0.001). Detection of C. difficile tpi gene in oral/fecal samples correlated with periodontal inflammation (p < 0.05). A modest intra-individual agreement between tpi gene detection in feces and saliva was found within periodontitis patients (Kappa = 0.314; p = 0.003).

CONCLUSION

The high frequency of the C. difficile specific genes tpi and tcdB in the dysbiotic subgingival biofilm of advanced periodontitis could support the presence of the bacterium in this niche.

Dogs in Rio de Janeiro as reservoirs of Clostridioides difficile ribotypes causing CDI in humans

INTRODUCTION

In the past decade, the incidence of community-acquired Clostridioides difficile infection (CA-CDI) has increased, suggesting a role for community reservoirs such as animals in its spread.

OBJECTIVE

This study aimed to isolate and characterize C. difficile strains from domestic dogs at veterinary clinics to enhance our understanding of C. difficile epidemiology in Rio de Janeiro.

MATERIAL AND METHODS

For this study 90 stool samples from dogs were collected and cultured in a selective medium (Clostridioides difficile Brucella agar - CDBA) for isolation. Species were identified by MALDI-TOF MS, with confirmation provided by PCR targeting the tpi gene. The antibiotic susceptibility test of the strains was performed using five antibiotics: vancomycin, metronidazole, moxifloxacin, rifampicin, and erythromycin. Strains resistant to metronidazole were further analyzed for the presence of the plasmid pCD-METRO using PCR. The presence of toxin genes (tcdA, tcdB, and cdtB) was investigated, alongside ribotyping and tcdC sequencing analyses. The strains were also tested for biofilm formation and motility.

RESULTS

C. difficile was isolated in 15.5 % (14/90) of the samples. Among the strains analyzed, 87.71 % (12/14) tested positive for both toxin genes tcdA and tcdB and belonged to ribotypes 106 (10/14) and 014/020 (2/14). The remaining 14.3 % (2/14) were non-toxigenic and were identified as ribotype 010. Regarding the antibiotic profile, 42.85 % (6/14) of the strains exhibited resistance to at least one antibiotic, including vancomycin (1/14) and metronidazole (1/14). The metronidazole-resistant strain was also positive for the plasmid pCD-METRO. All strains exhibited both biofilm formation and motility. Among the 12 toxigenic strains sequenced for the tcdC gene, two exhibited a deletion in the same region as the epidemic strain, NAP1 (RT027).

CONCLUSION

Our study found some overlap between C. difficile ribotypes isolated from dogs and from cases of CDI in humans, and the C. difficile prevalence was higher in dogs with diarrhea (p = 0.034).

High-Resolution Melting PCR as a Fast and Simple Molecular Biology-Based Method for the Identification of Hypervirulent Clostridioides difficile Strains Directly in Stool Samples

Clostridioides difficile became one of the main causes of nosocomial infections in all clinical settings worldwide, especially among patients undergoing antibiotic therapy. The incidence and severity of C. difficile infections, from mild diarrhea to life-threatening pseudomembranous colitis, correlate with the spread of the hypervirulent binary toxin (CDT)-producing strains. The use of the real-time HRM-PCR method enables the identification of hypervirulent C. difficile strains directly in the diarrheal stool samples of patients suspected of being infected with this bacterium. For this purpose, the cdtA and cdtB genes encoding CDT subunits, as well as the species-specific gluD gene, were detected to identify the presence of this bacterium in the tested samples. The sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of the established method were also assessed. The obtained results were compared with the results of eazyplex® C. difficile complete test (AmplexDiagnostics GmbH) based on the LAMP method, used in standard microbiological diagnostics. The values of the assessed diagnostic parameters for the detected genes ranged from 58.82% to 98.85%. The lowest value (58.82%) was obtained for the PPV of cdtB and the highest (98.85%) for the NPV of this gene. The real-time HRM-PCR method enables fast and simple detection of the investigated genes of hypervirulent C. difficile strains and, after careful optimization, may demonstrate high potential for usefulness in routine microbiological diagnostics.

Validation of Lyophilized Human Fecal Microbiota for the Treatment of Clostridioides difficile Infection: A Pilot Study with Pharmacoeconomic Analysis of a Middle-Income Country-Promicrobioma Project

BACKGROUND

Clostridioides difficile infection (CDI) represents a prevalent and potentially severe health concern linked to the usage of broad-spectrum antibiotics. The aim of this study was to evaluate a new lyophilized product based on human fecal microbiota for transplant, including cost-benefit analysis in the treatment of recurrent or refractory CDI.

METHODS

The product for fecal microbiota transplant was obtained from two donors. Microbiological, viability, and genomic analysis were evaluated. After validation, a clinical pilot study including recurrent or refractory CDI with 24 patients was performed. Clinical response and 4-week recurrence were the outcome. Cost-benefit analysis compared the fecal microbiota transplant with conventional retreatment with vancomycin or metronidazole.

RESULTS

The microbiota for transplant presented significant bacterial viability, with and adequate balance of Firmicutes and Bacteroidetes. The clinical response with the microbiota transplant was 92%. In financial terms, estimated expenditure for CDI solely related to recurrence, based on stochastic modeling, totals USD 222.8 million per year in Brazil.

CONCLUSIONS

The lyophilized human fecal microbiota for transplant is safe and can be an important step for a new product with low cost, even with genomic sequencing. Fecal microbiota transplantation emerges as a more cost-effective alternative compared to antimicrobials in the retreatment 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.

Molecular epidemiology of Clostridioides difficile obtained from fecal samples of wild animals in Brazil

ABSTRACT: Clostridioides difficile is a strictly anaerobic, spore-forming Gram-positive bacterium associated with diarrhea, known as C. difficile infection (CDI). In domestic animals, C. difficile is considered an important pathogen mostly in pigs and horses, but there are also reports in other domestic species. In wild animals, the epidemiology of C. difficile is largely unknown, and the role of the bacterium as a cause of diarrhea is unclear. The aim of this study was to determine the prevalence of C. difficile in the feces of wild animals referred to the Center of Medicine and Research in Wild Animals (CEMPAS). Fecal samples obtained from 100 animals of 34 different species were subjected to qPCR for the detection of the C. difficile 16S rRNA gene and two major toxin genes (tcdA and tcdB) and to anaerobic bacterial isolation. A total of 63 animals (63%) were positive for C. difficile by qPCR, and 16 isolates were recovered. The opossum (Didelphis spp.) had the highest number of positive animals in both tests (from 21 samples, 19 were qPCR positive, and four isolates were recovered). Three toxigenic strains (RT 002, 004, and 014), all previously described as infecting humans and animals, were isolated in the following species: bearded dragon (Pogona vitticeps), pampas fox (Lycalopex vetulus), and marmoset (Callithrix sp.). The presence of C. difficile in the feces of wild animals highlights the importance of wildlife as potential carriers of infection for production animals or humans.

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.

Community-associated Clostridioides difficile infection in a general hospital from Argentina

Toxin-producing Clostridioides difficile infection (CDI) is the leading cause of hospital-acquired diarrhea. However, it is now recognized as a cause of diarrhea in the community. This single-center study aimed to determine the epidemiological origin of CDI cases between January 2014 and December 2019 and to compare demographic characteristics, comorbidities, risk factors, severity, and mortality of community CDI with healthcare facility-associated CDI. There were 52 CDI cases from the community (34.4%). Community patients were significantly younger (53 yo vs. 65 yo), less comorbid (Charlson Index 1.65 vs. 3.98), and less severe (only one case). The main risk factor was the use of antibiotics in the previous 90 days (65%). However, we did not find any known risk factor in 7 patients.

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.

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.

Comparative biofilm-forming ability between Clostridioides difficile strains isolated in Latin America and the epidemic NAP1/027 strain

Introduction

One of the challenges in treating Clostridioides difficile infection (CDI) is that the bacterium forms biofilms, a critical virulence mechanism known to promote antibiotic resistance and, as a result, consequently, a higher recurrence of the disease. The goal of this study was to compare the ability of three MLST Clade 2 strains to form a biofilm in vitro: ICC-45 (ribotype SLO231/UK[CE]821), a ST41 toxinotype IXb isolated in Brazil; and two epidemic NAP1/027/ST01 strains: NAP1/027/ST01 (LIBA5756), isolated during a 2010 outbreak in Costa Rica and the reference epidemic strain NAP1/027/ST01 (R20291); and ATCC700057, a non-toxigenic strain.

Methods

The ability of strains to form biofilm was evaluated using crystal violet staining. In addition, samples were stained with the Film Tracer biofilm matrix (Invitrogen®) and the biofilm matrix thickness was measured using confocal microscopy. The matrix architecture was determined using Scanning electron microscop. Confocal microscopy was used to detect the presence of toxin A (tcdA) using an anti-Clostridioides difficile TcdA antibody. The expression of virulence genes (tcdA, tcdB, tcdC, cdtB, spo0A, slpA, cwp66 and cwp84) was examined, as well as the effect of antibiotics metronidazole (MTZ) and vancomycin (VAN) on biofilm growth.

Results

All of the strains tested formed a moderate biofilm with 1.1 <DO_570nm>3.5. After 72h, biofilm biomass of the NAP1/027/ST01 epidemic strains (LIBA5756 and R20291) was significantly higher than ICC-45 and ATCC 700057 biofilms, as confirmed by electron and confocal microscopy. At 120h, the LIBA5756 biofilm biomass decreased compared to other strains. The toxigenic strains R20291 or LIBA 5756 had higher expression of genes tcdA, tcdB, tcdC, cdtA, slpA and spo0A than ICC-45, but there were no significant differences in the expression levels of cdtB, cwp66 and cwp84. In epidemic strains, VAN and MTZ inhibited biofilm formation; however, in the ICC-45 strain, MIC concentrations of VAN and MIC and 4MIC of MTZ did not inhibit biofilm formation.

Conclusion

The three MLST Clade 2 isolated from different rybotipes, two of which were isolated from Latin America, are competent biofilm-forming bacteria, indicating their ability to induce C. difficile infection recurrence, making treatment difficult.

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.

Clostridioides difficile in Latin America: A comprehensive review of literature (1984-2021)

This narrative review summarizes literature on C. difficile and C. difficile infections (CDI) that emerged from Latin America (LA) between 1984 and 2021. The revised information includes papers in English, Spanish, or Portuguese that were retrieved from the databases Pubmed, Scopus, Web of Science, Google Scholar, Scielo, and Lilacs. Information is presented chronologically and segregated in subregions, focusing on clinical presentation, risk factors, detection and typing methods, prevalence and incidence rates, circulating strains, and, when available, phenotypic traits, such as antimicrobial susceptibility patterns. Studies dealing with cases, clinical aspects of CDI, and performance evaluations of diagnostic methods predominated. However, they showed substantial differences in case definitions, measuring units, populations, and experimental designs. Although a handful of autochthonous strains were identified, predominantly in Brazil and Costa Rica, the presentation and epidemiology of CDI in LA were highly comparable to what has been reported in other regions of the world. Few laboratories isolate and type this bacterium and even less generate whole genome sequences or perform basic science on C. difficile. Less than ten countries lead academic productivity on C. difficile or CDI-related topics, and information from various countries in Central America and the Caribbean is still lacking. The review ends with a global interpretation of the data and recommendations to further develop and consolidate this discipline in LA.

Clostridioides difficile colonisation among very young children in resource-limited settings

Objectives

To describe the epidemiology and risk factors for Clostridioides difficile (C. difficile) colonization among young children in eight low-resource settings.

Methods

We tested 41 354 monthly non-diarrhoeal and diarrhoeal stools for C. difficile toxin genes (TcdA and TcdB) using quantitative PCR (qPCR) in 1715 children from birth to age two years in a multisite birth cohort study. We estimated the prevalence, cumulative incidence, and seasonality of C. difficile colonization and investigated the associations of C. difficile detection with risk factors of infection, markers of enteropathy, and growth.

Results

The prevalence of C. difficile detection was lower in diarrhoeal (2.2%; n = 151/6731) compared to non-diarrhoeal stools (6.1%; n = 2106/34 623). By 24 months of age, the cumulative incidence of C. difficile varied widely by site, with 17.9% (n = 44; Pakistan) to 76.3% (n = 148; Peru) of children having at least one positive stool. Only Bangladesh and Pakistan had seasonal differences in C. difficile detection. Female sex (adjusted risk ratio (aRR): 1.18; 95% CI: 1.02–1.35), cephalosporin use in the past 15 days (aRR: 1.73; 95% CI: 1.39–2.16), and treated water (aRR: 1.24; 95% CI: 1.02–1.50) were risk factors for C. difficile positivity. The presence of C. difficile was significantly associated with elevated faecal myeloperoxidase, neopterin, and α-1-antitrypsin, but no associations were found between C. difficile and child growth at 24 months of age.

Discussion

C. difficile colonization among children ages 0–2 years was variable across low-resource settings. Significant elevation of intestinal inflammation and barrier disruption markers associated with C. difficile detection suggests a subclinical impact of colonization.

Clostridioides difficile and multi-drug-resistant staphylococci in free-living rodents and marsupials in parks of Belo Horizonte, Brazil

The global emergence of antimicrobial resistance (AMR) has become a serious threat to human and animal health. Recent studies have shown that synanthropic animals can act as reservoirs and disseminators of pathogens and resistant bacteria. The aim of this study was to evaluate the frequency, distribution, and antimicrobial susceptibility of staphylococcal species and Clostridioides difficile isolated from the feces of free-living rodents and marsupials from two urban parks in Belo Horizonte, Brazil. During a 12-month period, fecal samples from 159 free-living animals, including 136 rodents and 23 marsupials, were collected from two urban parks in Belo Horizonte, Minas Gerais, Brazil. Staphylococcus spp. were more likely to be isolated from rodents than marsupials (p = 0.0164). Eight different staphylococcal species were isolated from 36 (26.5%) rodents and one marsupial (4.3%). S. saprophyticus (48.6%) was the most frequently isolated species, and almost a quarter of the isolates (24.3%) were resistant to at least one antimicrobial agent, four (10.8%) of which were multi-drug resistant (MDR). Two (5.4%) strains were resistant to cefoxitin and were then classified as methicillin-resistant staphylococci, and one also tested positive for the mecA gene. C. difficile was isolated from two rodents (1.5%), and one strain was toxigenic and classified as ribotype 064. One isolate was resistant to rifampicin, but both strains were susceptible to all other antimicrobials tested, including metronidazole and vancomycin. All C. difficile isolates and all staphylococcal strains resistant to antimicrobials were recovered from the same park. The present study suggests that free-living rodents in Belo Horizonte (Brazil) are mainly colonized by S. saprophyticus and may act as reservoirs of antimicrobial-resistant Staphylococcus spp. and C. difficile strains. This is the first study to evaluate the presence of staphylococci and C. difficile from free-living opossums and suggest a low fecal shedding of these organisms by these mammals.

A cost of illness comparison for toxigenic Clostridioides difficile diagnosis algorithms in developing countries

BACKGROUND

Availability of several commercial tests with different Clostridioides difficile targets contributes to uncertainty and controversies around the optimal diagnostic algorithm. While numerous studies have estimated the financial impact of C. difficile infection, models to guide testing strategies decisions in developing countries, where economic value significantly impacts clinical practice, are currently not available.

AIM

To determine the cost of illness of different C. difficile infection (CDI) diagnostic strategies in developing countries.

METHODS

Cost-comparison analysis was performed to compare eleven different algorithms of CDI diagnosis. The basis of calculation was a hypothetical cohort of 1000 adult inpatients suspected of CDI. We analyzed turnaround time of test results (i.e., time from taking sample to results emission), test performance (i.e., sensitivity and specificity) and testing costs. Patients were divided in true positive, false positive, true negative and false negative in order to integrate test performance and economics effects. Additional medical costs were calculated: costs of hygiene, medication, length of stay and intensive care unit costs, based on a Brazilian University Hospital costs. CDI prevalence was considered 22.64%.

FINDINGS

From laboratory-assisted tests, simultaneous glutamate dehydrogenase (GDH) and toxin A/B rapid immunoassay arbitrated by nucleic acid amplification test (NAAT) presented the lowest cost of illness (450,038.70 USD), whereas standalone NAAT had the highest (523,709.55 USD). Empirical diagnosis only presented the highest overall cost (809,605.44 USD).

CONCLUSION

The two-step algorithm with simultaneous GDH and toxin A/B rapid immunoassay arbitrated by NAAT seems to be the best strategy for CDI diagnosis in developing countries.

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).

MALDI-TOF MS: An alternative approach for ribotyping Clostridioides difficile isolates in Brazil

Clostridioides difficile is an important organism causing healthcare-associated infections. It has been documented that specific strains caused multiple outbreaks globally, and patients infected with those strains are more likely to develop severe C. difficile infection (CDI). With the appearance of a variant strain, BI/NAP1 ribotype 027, responsible for several outbreaks and high mortality rates worldwide, the epidemiology of the CDI changed drastically in the United States, Europe, and some Latin American countries. Although the epidemic strain 027 was not yet detected in Brazil, there are ribotypes exclusively found in the country, such as, 131, 132, 133, 135, 142 and 143, which are responsible for outbreaks in Brazilian hospitals and nursing homes. Although PCR-ribotyping is the most used method in epidemiology studies of C. difficile, it is not available in Brazil. This study aimed to develop and validate an in-house database for detecting C. difficile ribotypes, usually involved in CDI in Brazilian hospitals, by using MALDI-TOF MS. A database with 19 different ribotypes, 13 with worldwide circulation and 6 Brazilian-restricted, was created based on 27 spectra readings of each ribotype. After BioNumerics analysis, neighbor-joining trees revealed that spectra were distributed in clusters according to ribotypes, showing that MALDI-TOF MS could discriminate all 19 ribotypes. Moreover, each ribotype showed a different profile with 42 biomarkers detected in total. Based on their intensity and occurrence, 13 biomarkers were chosen to compose ribotype-specific profiles, and in silico analysis showed that most of these biomarkers were uncharacterized proteins or well-conserved peptides, such as ribosomal proteins. A double-blind assessment using the 13 biomarkers correctly assigned the ribotype in 73% of the spectra analyzed, with 94%-100% of correct hits for 027 and for Brazilian ribotypes. Although further analyses are required, our results show that MALDI-TOF MS might be a reliable, fast and feasible alternative for epidemiological surveillance of C. difficile in Brazil.

Detection and pathogenic potential of Clostridium difficile in commercial meat and meat products in Brazil

The aims of this study were to evaluate the occurrence of Clostridium difficile in commercial raw meat and meat products commercialized in Brazil, and to determine the pathogenic potential and antimicrobial susceptibility of the isolates. After selective enrichment, the isolation of C. difficile involved plating with and without an alcohol shock treatment onto C. difficile moxalactam agar (CDMNA). The toxigenic profile was determined through PCR for detection of tcdA, tcdB, cdtA and cdtB genes and an enzyme-linked immunosorbent assay for toxin A/B. C. difficile was isolated from 8.9% (17 out of 192) of analyzed samples. Plating without alcohol treatment (sensitivity of 88.23%) was more efficient than with alcohol treatment (sensitivity of 29.41%) in C. difficile isolation. The profile A + B+CDT- was observed in 35.0% (28/80) of the isolates. The A/B toxin was tested in 44 isolates and 15.9% of them were positive. Resistance to clindamycin, ceftizoxime tetracycline, metronidazole, vancomycin, and ceftriaxone were observed among isolates. Multi-drug resistance was detected in 36.4% (8/22) of the isolates evaluated.

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.

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.

Introduction to the special issue for The anaerobe society of the America's 14th Biennial congress in Las Vegas

In June 2018, the Anaerobe Society of the America's (ASA) held their 14th Biennial Congress in Las Vegas, Nevada. The Congress was attended by over 200 individuals from many different countries. The focus of the meeting was the fast-growing area of anaerobes in human and animal infectious disease, computational tools to understand basic biology and therapeutic development, the role of anaerobes in the microbiome, and clinical trials of novel bacterial-based therapies. To strengthen the community of researchers working on anaerobes, the congress held two training workshops on clinical bacteriology and anaerobes in the microbiome, several networking events, as well as a dinner which honored the lifetime achievement award given to Ellen Jo Baron. The meeting was also attended by the grandfather of anaerobic bacteriology and the founder of (ASA), Sydney Finegold, at the age of 97. In all, there was a broad diversity of research presented that showed new ways that anaerobes play a important role in health and disease.