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Background

Antibiotic exposure is a known risk factor for Clostridioides difficile infection (CDI) and recurrence and can lead to infection with specific C. difficile strains. In this study, we sought to explore the relationship between antecedent antibiotic exposure and C. difficile antimicrobial resistance, and the impact of resistance on clinical outcomes.

Methods

This was a single center retrospective study evaluating patients with CDI between 2011 and 2021. A logistic regression model was used to evaluate the relationship between antecedent antibiotics in the 30 days prior to CDI and resistance among isolates. In addition, an exploratory analysis using a cause-specific Cox proportional hazards model evaluated the association between resistance and a composite outcome of clinical failure, relapse at 30 days or CDI-related death.

Results

we analyzed one isolate from 510 patients; resistance was noted in 339 (66.5 %) of the isolates. Exposure to fluoroquinolones and macrolides was associated with 2.4 (95 % CI 1.4–4.4) and 4.7 (95 % CI 1.1–20.5) increased odds of having resistance compared to other antibiotic class exposure, respectively. There were 58 (17.0 %) patients in the resistance group who developed the composite outcome and 24 (14.2 %) patients who lacked resistance who developed the composite outcome (HR 1.32, 95 % CI 0.81–2.14).

Conclusion

These findings suggest that fluoroquinolone and macrolide exposure were significantly associated with isolating a resistant strain, but we did not find significant differences in clinical outcomes based on the presence of antimicrobial resistance.

Introduction

Clostridioides difficile is the main cause of antibiotic-associated diarrhea in humans and is a major enteropathogen in several animal species. In newborn piglets, colonic lesions caused by C. difficile A and B toxins (TcdA and TcdB, respectively) cause diarrhea and significant production losses.

Objective

The present study aimed to develop two recombinant vaccines from immunogenic C-terminal fragments of TcdA and TcdB and evaluate the immune response in rabbits and in breeding sows. Two vaccines were produced: bivalent (rAB), consisting of recombinant fragments of TcdA and TcdB, and chimeric (rQAB), corresponding to the synthesis of the same fragments in a single protein. Groups of rabbits were inoculated with 10 or 50 μg of proteins adjuvanted with aluminum or 0.85 % sterile saline in a final volume of 1 mL/dose. Anti-TcdA and anti-TcdB IgG antibodies were detected in rabbits and sows immunized with both rAB and rQAB vaccines by ELISA. The vaccinated sows were inoculated intramuscularly with 20 μg/dose using a prime-boost approach.

Results

Different antibody titers (p ≤ 0.05) were observed among the vaccinated groups of sows (rAB and rQAB) and control. Additionally, newborn piglets from vaccinated sows were also positive for anti-TcdA and anti-TcdB IgGs, in contrast to control piglets (p ≤ 0.05). Immunization of sows with the rQAB vaccine conferred higher anti-TcdA and anti-TcdB responses in piglets, suggesting the superiority of this compound over rAB.

Conclusion

The synthesized recombinant proteins were capable of inducing antibody titers against C. difficile toxins A and B in sows, and were passively transferred to piglets through colostrum.

Bovine digital dermatitis (BDD) is an infectious skin disease of the hoof characterized by painful ulcerations that cause lameness in dairy cattle. Cell-free supernatants (CFS) of Falsiporphyromonas endometrii predominantly isolated from BDD lesions had the highest growth-stimulating effect on Treponema phagedenis among BDD-associated bacteria. Butyric acid was detected at a concentration of 45.4 mM in CFS of F. endometrii, and the growth of T. phagedenis was significantly promoted by butyric acid supplementation.

This study reports a botulism outbreak on a pig farm. Clostridium botulinum type C was detected using PCR. The gene encoding the toxin corresponds to a novel type C neurotoxin recently described in a human botulism outbreak, raising the question of its prevalence in pigs and the related risks to humans.

Objectives

Syntrophy has been documented between pectinophiles and methanol-utilizing bacteria, along with instances of cross-feeding between pectinophiles and methanogens. However, studies on the ecology of pectinophiles in anaerobic digestion (AD) are lacking. Therefore, in this study, we aimed to elucidate the ecology of pectinophiles by isolating novel pectinophile forms and conducting a comprehensive analysis of their physiology and ecology.

Methods

Complex microbial communities from AD systems were enriched in a pectin-containing medium; subsequently, specific strains were isolated using a pectinophile isolation method. The carbon source assimilation and growth ability of the isolates, along with their symbiotic relationships, were evaluated using batch tests.

Results

Strain LPYR103-Pre exhibited 16S rRNA gene sequence similarity and average nucleotide identity values of 94.3 % and 77.9 %, respectively, compared to its closest related species, Segatella cerevisiae. Strain LPYR103-Pre demonstrated attenuated growth in the presence of eight common sugars but exhibited remarkably high growth in the presence of pectin, d-galacturonate, and d-glucuronate, with succinate being identified as a primary metabolite. Accumulation of succinate inhibited the growth of strain LPYR103-Pre. However, this growth impediment was alleviated by Dialister hominis LPYG114-Dih, whose growth required succinate.

Conclusions

Our results elucidate the specific carbon source requirements of the Segatella-like strain LPYR103-Pre and succinate-mediated symbiosis involving D. hominis. These findings provide new insights into the degradation of pectin and its degradation products during AD, contributing to the identification of unknown pectinophiles.

Background

Colorectal cancer (CRC) is a significant global health concern, and understanding the role of specific bacterial infections in its development and progression is of increasing interest. This cross-sectional study investigated the associations between Bacteroides fragilis (B. fragilis) and Fusobacterium nucleatum (F. nucleatum) infections and Vietnamese CRC patients.

Methods

192 patients with either polyps or CRC at varying stages were recruited from May 2017 to December 2020. Real-time PCR assessed infection rates and bacterial loads in CRC tissues.

Results

B. fragilis infection was notably higher in CRC tissues (51.6 %) than polyps (9.4 %), with a fivefold higher relative load. Positive associations were found in stages II and III, indicating a fivefold increase in CRC progression risk. F. nucleatum infection rates were significantly higher in CRC tissues (55.2 %) than in polyps (10.5 %). In stage II, the infection rate exceeded that in adjacent tissues. The relative load of F. nucleatum was higher in stage III than in stages I and II. Positive F. nucleatum patients had a 3.2 times higher risk of CRC progression.

Conclusion

These findings suggest associations between loading of F. nucleatum or/and B. fragilis with the advanced stages of CRC.

Objectives

The genus Faecalibacterium is one of the most important butyrate producers in the human intestinal tract and has been widely linked to health. Recently, several different species have been described, but still more phylogroups have been identified, suggesting that additional species may exist. Four strains HTF-F^T, HTF-128, HTF-75H and HTF-76H, representing two different phylogenetic clusters, are evaluated in this study.

Methods

Phylogenomic analysis was performed using whole-genome sequences and 16S rRNA gene sequences. Chemotaxonomic analysis was done based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Physiological and phenotypical characteristics of these strains were also determined. All characteristics of these strains were compared with other validly published species within the genus Faecalibacterium.

Results

On a genomic level, the strains HTF-F^T and HTF-128 shared an average nucleotide identity (ANI) of <95.0 % and digital DNA-DNA hybridization (dDDH) of <70.0 with other Faecalibacterium species, while between HTF-F^T and HTF-128 the ANI-value was 97.18 % and the dDDH was 76.8 %. HTF-75H and HTF-76H had an ANI and dDDH value of 100 % (99.96 %) and 100 % (99.99 %) respectively. Both HTF-75H and HTF-76H were closely related to Faecalibacterium taiwanense HLW78^T. 16S rRNA gene and chemotaxonomic analysis were in accordance with the genomic data, confirming that HTF-F^T and HTF-128 represent a novel Faecalibacterium species and HTF-75H and HTF-76H belong to F. taiwanense.

Conclusions

Faecalibacterium strains HTF-F^T (=DSM 117771^T = NCIMB 15531^T) and HTF-128 represent a novel species. The name Faecalibacterium wellingii with HTF-F^T as type strain is proposed. Two novel isolates HTF-75H (=DSM 17770 = NCIMB 15530) and HTF-76H are described in this study and belong to the recently described Faecalibacterium taiwanense.

Clostridioides difficile infection (CDI) is an important cause of morbidity and mortality worldwide. Data from public health surveillance systems are important for estimating country-level CDI burden. CDI surveillance can be population-based or hospital-based. Population-based surveillance results in overall estimates of CDI incidence (cases per 100,000 population-per-year), and hospital-based surveillance results in estimates of hospital-based CDI incidence (cases per 10,000 patient-days) or CDI admission rates (cases per 1,000 admissions). We sought to better understand temporal trends in CDI incidence reported in publicly available surveillance data worldwide and describe varying surveillance methods. We identified 13 countries in Europe, North America, and Oceania with publicly available population-based and/or hospital-based CDI surveillance data in online reports and/or dashboards. Additional countries in Europe, in particular, also conduct hospital-based CDI surveillance. Inconsistent CDI case definitions and surveillance approaches between countries limit the interpretability of multi-country comparisons. Nonetheless, publicly available CDI surveillance data enabled us to compare CDI incidence among countries with population-based and/or hospital-based surveillance systems and to describe trends in CDI incidence within countries over time. The highest CDI incidence is in the United States. While there have been recent declines in CDI incidence in all countries, the CDI burden remains high, and the need persists for CDI prevention strategies in communities and healthcare settings.

Veillonella parvula is a non-motile Gram-negative coccus that forms part of the normal microbiota in several body sites and which has been rarely isolated as cause of infections in human population, particularly in bacteremias. Here we give the overview of characteristics of genus Veillonella and the summary of its role in infections, particularly in bacteremia. We additionally report two patients with bacteremia due to V. parvula. Two sets of blood cultures of each patient yielded a pure culture of an anaerobic microorganism identified as V. parvula by MALDI-TOF MS, and confirmed by 16S rRNA gene sequencing. The two patients were male and one of them had risk factors for anaerobic bacteremia. The isolates were susceptible to most antibiotics and the outcome was successful in both patients. Bacteremia due to V. parvula is still rare. MALDI-TOF MS appear to be an excellent tool for the correct identification of these species.