Genomic Analysis of a Pathogenic Bacterium, Paeniclostridium sordellii CBA7122 Containing the Highest Number of rRNA Operons, Isolated from a Human Stool Sample.
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ABSTRACT:
SUBMITTER: Kim JY
PROVIDER: S-EPMC5695201 | biostudies-literature | 2017
REPOSITORIES: biostudies-literature
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Genomic Analysis of a Pathogenic Bacterium, <i>Paeniclostridium sordellii</i> CBA7122 Containing the Highest Number of rRNA Operons, Isolated from a Human Stool Sample.
Kim Joon Yong JY Kim Yeon Bee YB Song Hye Seon HS Chung Won-Hyong WH Lee Changsu C Ahn Seung Woo SW Lee Se Hee SH Jung Min Young MY Kim Tae-Woon TW Nam Young-Do YD Roh Seong Woon SW
Frontiers in pharmacology 20171115
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Project description:(1) Background: The purpose of this study was to determine the prevalence of clostridia strains in a hospital environment in Algeria and to evaluate their antimicrobial susceptibility to antibiotics and biocides. (2) Methods: Five hundred surface samples were collected from surfaces in the intensive care unit and surgical wards in the University Hospital of Tlemcen, Algeria. Bacterial identification was carried out using MALDI-TOF-MS, and then the minimum inhibitory concentrations (MICs) of various antimicrobial agents were determined by the E-test method. P. sordellii toxins were searched by enzymatic and PCR assays. Seven products intended for daily disinfection in the hospitals were tested against Clostridium spp. spore collections. (3) Results: Among 100 isolates, 90 P. sordellii were identified, and all strains were devoid of lethal and hemorrhagic toxin genes. Beta-lactam, linezolid, vancomycin, tigecycline, rifampicin, and chloramphenicol all proved effective against isolated strains. Among all strains tested, the spores of P. sordellii exhibited remarkable resistance to the tested biocides compared to other Clostridium species. The (chlorine-based 0.6%, 30 min), (glutaraldehyde solution 2.5%, 30 min), and (hydrogen peroxide/peracetic acid 3%, 15 min) products achieved the required reduction in spores. (4) Conclusions: Our hospital's current cleaning and disinfection methods need to be optimized to effectively remove spores from caregivers' hands, equipment, and surfaces.
| S-EPMC8772839 | biostudies-literature
Project description:Hemorrhagic toxin (TcsH) is a major virulence factor produced by Paeniclostridium sordellii, which is a non-negligible threat to women undergoing childbirth or abortions. Recently, Transmembrane Serine Protease 2 (TMPRSS2) was identified as a host receptor of TcsH. Here, we show the cryo-EM structures of the TcsH-TMPRSS2 complex and uncover that TcsH binds to the serine protease domain (SPD) of TMPRSS2 through the CROP unit-VI. This receptor binding mode is unique among LCTs. Five top surface loops of TMPRSS2SPD, which also determine the protease substrate specificity, constitute the structural determinants recognized by TcsH. The binding of TcsH inhibits the proteolytic activity of TMPRSS2, whereas its implication in disease manifestations remains unclear. We further show that mutations selectively disrupting TMPRSS2-binding reduce TcsH toxicity in the intestinal epithelium of the female mice. These findings together shed light on the distinct molecular basis of TcsH-TMPRSS2 interactions, which expands our knowledge of host recognition mechanisms employed by LCTs and provides novel targets for developing therapeutics against P. sordellii infections.
| S-EPMC10912200 | biostudies-literature
Project description:Hemorrhagic toxin (TcsH) is an important exotoxin produced by Paeniclostridium sordellii, but the exact role of TcsH in the pathogenesis remains unclear, partly due to the lack of knowledge of host receptor(s). Here, we carried out two genome-wide CRISPR/Cas9 screens parallelly with TcsH and identified cell surface fucosylation and TMPRSS2 as host factors contributing to the binding and entry of TcsH. Genetic deletion of either fucosylation biosynthesis enzymes or TMPRSS2 in the cells confers resistance to TcsH intoxication. Interestingly, TMPRSS2 and fucosylated glycans can mediate the binding/entry of TcsH independently, thus serving as redundant receptors. Both TMPRSS2 and fucosylation recognize TcsH through its CROPs domain. By using Tmprss2‒/‒ mice, we show that Tmprss2 is important for TcsH-induced systematic toxicity and colonic epithelial lesions. These findings reveal the importance of TMPRSS2 and surface fucosylation in TcsH actions and further provide insights into host recognition mechanisms for large clostridial toxins.
| S-EPMC9321280 | biostudies-literature
Project description:Chromids (secondary chromosomes) in bacterial genomes that are present in addition to the main chromosome appear to be evolutionarily conserved in some specific bacterial groups. In rare cases among these groups, a small number of strains from Rhizobiales and Vibrionales were shown to possess a naturally fused single chromosome that was reported to have been generated through intragenomic homologous recombination between repeated sequences on the chromosome and chromid. Similar examples have never been reported in the family Burkholderiaceae, a well-documented group that conserves chromids. Here, an in-depth genomic characterization was performed on a Burkholderiaceae bacterium that was isolated from a soil bacterial consortium maintained on diesel fuel and mutagenic benzo[a]pyrene. This organism, Cupriavidus necator strain KK10, was revealed to carry a single chromosome with unexpectedly large size (>6.6 Mb), and results of comparative genomics with the genome of C. necator N-1T indicated that the single chromosome of KK10 was generated through fusion of the prototypical chromosome and chromid at the rRNA operons. This fusion hypothetically occurred through homologous recombination with a crossover between repeated rRNA operons on the chromosome and chromid. Some metabolic functions that were likely expressed from genes on the prototypical chromid region were indicated to be retained. If this phenomenon-the bacterial chromosome-chromid fusion across the rRNA operons through homologous recombination-occurs universally in prokaryotes, the multiple rRNA operons in bacterial genomes may not only contribute to the robustness of ribosome function, but also provide more opportunities for genomic rearrangements through frequent recombination. IMPORTANCE A bacterial chromosome that was naturally fused with the secondary chromosome, or "chromid," and presented as an unexpectedly large single replicon was discovered in the genome of Cupriavidus necator strain KK10, a biotechnologically useful member of the family Burkholderiaceae. Although Burkholderiaceae is a well-documented group that conserves chromids in their genomes, this chromosomal fusion event has not been previously reported for this family. This fusion has hypothetically occurred through intragenomic homologous recombination between repeated rRNA operons and, if so, provides novel insight into the potential of multiple rRNA operons in bacterial genomes to lead to chromosome-chromid fusion. The harsh conditions under which strain KK10 was maintained-a genotoxic hydrocarbon-enriched milieu-may have provided this genotype with a niche in which to survive.
| S-EPMC8729776 | biostudies-literature
Project description:Paeniclostridium sordellii lethal toxin (TcsL) is a potent exotoxin that causes lethal toxic shock syndrome associated with fulminant bacterial infections. TcsL belongs to the large clostridial toxin (LCT) family. Here, we report that TcsL with varied lengths of combined repetitive oligopeptides (CROPs) deleted show increased autoproteolysis as well as higher cytotoxicity. We next present cryo-EM structures of full-length TcsL, at neutral (pH 7.4) and acidic (pH 5.0) conditions. The TcsL at neutral pH exhibits in the open conformation, which resembles reported TcdB structures. Low pH induces the conformational change of partial TcsL to the closed form. Two intracellular interfaces are observed in the closed conformation, which possibly locks the cysteine protease domain and hinders the binding of the host receptor. Our findings provide insights into the structure and function of TcsL and reveal mechanisms for CROPs-mediated modulation of autoproteolysis and cytotoxicity, which could be common across the LCT family.
| S-EPMC10730571 | biostudies-literature
Project description:ObjectivePaeniclostridium sordellii is a pathogen that causes rapidly fatal infections characterized by severe edema, extreme leukemoid reaction and lack of an innate immune response. We recently identified a metalloproteinase of P. sordellii-1 (Mcs1) that cleaves human vascular cell adhesion molecule 1, an adhesion molecule important to hematopoietic precursor retention and leukocyte diapedesis. In the current study, we further characterize Mcs1 activity and investigate its role in pathogenesis.MethodsMcs1 peptide cleavage sequence and activity conditions were identified using a semi-quantitative fluorescence-based reporter assay. Additional host targets for Mcs1 protease activity were tested and confirmed by gel electrophoreses and western blots. Finally, Mcs1 knock out (ΔMcs1) and complemented (cMcs1) strains were developed for assessment in our animal model of myonecrosis.ResultsData show that Mcs1 prefers aliphatic amino acid residues, I or L, especially when adjacent to negatively charged or noncharged-polar residues. In vitro, Mcs1 cleaved or partially cleaved human cell adhesion molecules, E-selectin and intracellular adhesion molecule-1 (ICAM-1), and mediators of innate immune infection defense, complement protein-3 and antimicrobial peptide LL-37. In vivo, infection with the ΔMcs1 P. sordellii strain had little effect on animal survival, tissue destruction or circulating white blood cell counts compared to wild type and cMcs1 strains.ConclusionsSimilar to proteolytic virulence factors from other pathogens, Mcs1 is a promiscuous protease that cleaves multiple human-host factors. Despite minimal impact of Mcs1 on the murine model of P. sordellii infection, it is worth considering its role in humans and other animal models.
| S-EPMC9023605 | biostudies-literature
Project description:The exotoxin TcsL is a major virulence factor in Paeniclostridium (Clostridium) sordellii and responsible for the high lethality rate associated with P. sordellii infection. Here, we present a genome-wide CRISPR-Cas9-mediated screen using a human lung carcinoma cell line and identify semaphorin (SEMA) 6A and 6B as receptors for TcsL. Disrupting SEMA6A/6B expression in several distinct human cell lines and primary human endothelial cells results in reduced TcsL sensitivity, while SEMA6A/6B over-expression increases their sensitivity. TcsL recognizes the extracellular domain (ECD) of SEMA6A/6B via a region homologous to the receptor-binding site in Clostridioides difficile toxin B (TcdB), which binds the human receptor Frizzled. Exchanging the receptor-binding interfaces between TcsL and TcdB switches their receptor-binding specificity. Finally, administration of SEMA6A-ECD proteins protects human cells from TcsL toxicity and reduces TcsL-induced damage to lung tissues and the lethality rate in mice. These findings establish SEMA6A and 6B as pathophysiologically relevant receptors for TcsL.
| S-EPMC7228847 | biostudies-literature
Project description:Paeniclostridium sordellii hemorrhagic toxin (TcsH) and Clostridioides difficile toxin A (TcdA) are two major members of the large clostridial toxin (LCT) family. These two toxins share ~87% similarity and are known to cause severe hemorrhagic pathology in animals. Yet, the pathogenesis of their hemorrhagic toxicity has been mysterious for decades. Here, we examined the liver injury after systemic exposure to different LCTs and found that only TcsH and TcdA induce overt hepatic hemorrhage. By investigating the chimeric and truncated toxins, we demonstrated that the enzymatic domain of TcsH alone is not sufficient to determine its potent hepatic hemorrhagic toxicity in mice. Likewise, the combined repetitive oligopeptide (CROP) domain of TcsH/TcdA alone also failed to explain their strong hemorrhagic activity in mice. Lastly, we showed that disrupting the first two short repeats of CROPs in TcsH and TcdA impaired hemorrhagic toxicity without causing overt changes in cytotoxicity and lethality. These findings lead to a deeper understanding of toxin-induced hemorrhage and the pathogenesis of LCTs and could be insightful in developing therapeutic avenues against clostridial infections.ImportancePaeniclostridium sordellii and Clostridioides difficile infections often cause hemorrhage in the affected tissues and organs, which is mainly attributed to their hemorrhagic toxins, TcsH and TcdA. In this study, we demonstrate that TcsH and TcdA, but not other related toxins. including Clostridioides difficile toxin B and TcsL, induce severe hepatic hemorrhage in mice. We further determine that a small region in TcsH and TcdA is critical for the hemorrhagic toxicity but not cytotoxicity or lethality of these toxins. Based on these results, we propose that the hemorrhagic toxicity of TcsH and TcdA is due to an uncharacterized mechanism, such as the presence of an unknown receptor, and future studies to identify the interactive host factors are warranted.
| S-EPMC11237598 | biostudies-literature
Project description:BackgroundWith the current rise of antibiotic resistance in bacteria, it is important to monitor the efficacy of antimicrobials in clinical use. Paeniclostridium sordellii (previously Clostridium sordellii) is a bacterial pathogen that causes human uterine infection after spontaneous or medically induced abortion, for which mortality rates approach 100%. Prophylactic antibiotics have been recommended for individuals undergoing medically-induced abortion, one of which is doxycycline, a member of the tetracycline antibiotic family. However, tetracycline resistance had not been well characterized in P. sordellii. This study therefore aimed to determine the levels of tetracycline resistance in P. sordellii isolates, and to identify associated loci and their genomic locations.ResultsUsing a MIC assay, five of 24 P. sordellii isolates were found to be resistant to tetracycline, minocycline, and importantly, doxycycline. Analysis of genome sequence data from 46 isolates found that phenotypically resistant isolates encoded a variant of the Clostridium perfringens tetracycline resistance determinant Tet P. Bioinformatic analysis and comparison of the regions surrounding these determinants found variation in the genomic location of Tet P among P. sordellii isolates. The core genome comparison of the 46 isolates revealed genetic diversity and the absence of dominant genetic types among the isolates. There was no strong association between geographic location of isolation, animal host or Tet P carriage with isolate genetic type. Furthermore, the analysis of the Tet P genotype revealed that Tet P is encoded chromosomally, or on one of two, novel, small plasmids, all consistent with multiple acquisition and recombination events. BLAST analysis of Clostridioides difficile draft genome sequences also identified a Tet P locus, the genomic location of which demonstrated an evolutionary relationship with the P. sordellii locus.ConclusionsThe Tet P determinant is found in variable genomic locations within diverse human and animal isolates of P. sordellii and C. difficile, which suggests that it can undergo horizontal transfer, and may disseminate tetracycline resistance between clostridial species. Doxycycline is a suggested prophylactic treatment for P. sordellii infections, however, a small sub-set of the isolates tested are resistant to this antibiotic. Doxycycline may therefore not be an appropriate prophylactic treatment for P. sordellii infections.
| S-EPMC6399922 | biostudies-literature
Project description:Clostridium sordellii is usually associated with skin and soft tissue infections. We describe the first case to our knowledge of a Clostridium sordellii-associated brain abscess, diagnosed by 16S rRNA gene sequencing, expanding the microbiological spectrum of brain abscesses, with emphasis on the role of 16S rRNA gene PCR in their etiologic diagnosis.
| S-EPMC2937712 | biostudies-literature