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Case Reports in Nephrology and Dialysis 2024The genus, encompassing gram-positive coccoid actinobacteria belonging to the Micrococcaceae family, has recently been discovered residing on the human skin and oral...
INTRODUCTION
The genus, encompassing gram-positive coccoid actinobacteria belonging to the Micrococcaceae family, has recently been discovered residing on the human skin and oral flora. Reports of -associated infections in humans have been scarce. Herein, we present the first case of relapsing peritoneal dialysis (PD)-associated peritonitis caused by .
CASE PRESENTATION
The patient, a 78-year-old male, presented with turbid effluent PD fluid, accompanied by an elevated white blood cell count of 253 cells/μL, of which 59% were neutrophils. A diagnosis of PD-associated peritonitis was established, leading to the initiation of intraperitoneal administration of ceftazidime and vancomycin. Subsequently, was identified through the bacterial culture of the dialysate. On the seventh day of initial treatment, the antibiotic regimen was changed to penicillin G, and the patient underwent a 3-week course of antibiotics. However, 1 week after discharge, the patient's dialysis fluid became cloudy once again, with subsequent detection of in the fluid culture. Ultimately, the decision was made to remove the patient's PD catheter and transition to hemodialysis.
CONCLUSION
PD-associated peritonitis attributed to may be considered a potential risk for recurrence.
PubMed: 38179178
DOI: 10.1159/000534765 -
Developmental and Comparative Immunology Jul 2024Renibacterium salmoninarum causes Bacterial Kidney Disease (BKD) in several fish species. Atlantic lumpfish, a cleaner fish, is susceptible to R. salmoninarum. To...
Renibacterium salmoninarum causes Bacterial Kidney Disease (BKD) in several fish species. Atlantic lumpfish, a cleaner fish, is susceptible to R. salmoninarum. To profile the transcriptome response of lumpfish to R. salmoninarum at early and chronic infection stages, fish were intraperitoneally injected with either a high dose of R. salmoninarum (1 × 10 cells dose) or PBS (control). Head kidney tissue samples were collected at 28- and 98-days post-infection (dpi) for RNA sequencing. Transcriptomic profiling identified 1971 and 139 differentially expressed genes (DEGs) in infected compared with control samples at 28 and 98 dpi, respectively. At 28 dpi, R. salmoninarum-induced genes (n = 434) mainly involved in innate and adaptive immune response-related pathways, whereas R. salmoninarum-suppressed genes (n = 1537) were largely connected to amino acid metabolism and cellular processes. Cell-mediated immunity-related genes showed dysregulation at 98 dpi. Several immune-signalling pathways were dysregulated in response to R. salmoninarum, including apoptosis, alternative complement, JAK-STAT signalling, and MHC-I dependent pathways. In summary, R. salmoninarum causes immune suppression at early infection, whereas lumpfish induce a cell-mediated immune response at chronic infection. This study provides a complete depiction of diverse immune mechanisms dysregulated by R. salmoninarum in lumpfish and opens new avenues to develop immune prophylactic tools to prevent BKD.
Topics: Animals; Head Kidney; Fish Diseases; Renibacterium; Gene Expression Profiling; Transcriptome; Immunity, Innate; Fish Proteins; Adaptive Immunity; Fishes; Chronic Disease; Perciformes; Gram-Negative Bacterial Infections; Kidney Diseases; Micrococcaceae
PubMed: 38499166
DOI: 10.1016/j.dci.2024.105165 -
Microbiome Feb 2024Bioaugmentation has the potential to enhance the ability of ecological technology to treat sulfonamide-containing wastewater, but the low viability of the exogenous...
BACKGROUND
Bioaugmentation has the potential to enhance the ability of ecological technology to treat sulfonamide-containing wastewater, but the low viability of the exogenous degraders limits their practical application. Understanding the mechanism is important to enhance and optimize performance of the bioaugmentation, which requires a multifaceted analysis of the microbial communities. Here, DNA-stable isotope probing (DNA-SIP) and metagenomic analysis were conducted to decipher the bioaugmentation mechanisms in stabilization pond sediment microcosms inoculated with sulfamethoxazole (SMX)-degrading bacteria (Pseudomonas sp. M2 or Paenarthrobacter sp. R1).
RESULTS
The bioaugmentation with both strains M2 and R1, especially strain R1, significantly improved the biodegradation rate of SMX, and its biodegradation capacity was sustainable within a certain cycle (subjected to three repeated SMX additions). The removal strategy using exogenous degrading bacteria also significantly abated the accumulation and transmission risk of antibiotic resistance genes (ARGs). Strain M2 inoculation significantly lowered bacterial diversity and altered the sediment bacterial community, while strain R1 inoculation had a slight effect on the bacterial community and was closely associated with indigenous microorganisms. Paenarthrobacter was identified as the primary SMX-assimilating bacteria in both bioaugmentation systems based on DNA-SIP analysis. Combining genomic information with pure culture evidence, strain R1 enhanced SMX removal by directly participating in SMX degradation, while strain M2 did it by both participating in SMX degradation and stimulating SMX-degrading activity of indigenous microorganisms (Paenarthrobacter) in the community.
CONCLUSIONS
Our findings demonstrate that bioaugmentation using SMX-degrading bacteria was a feasible strategy for SMX clean-up in terms of the degradation efficiency of SMX, the risk of ARG transmission, as well as the impact on the bacterial community, and the advantage of bioaugmentation with Paenarthrobacter sp. R1 was also highlighted. Video Abstract.
Topics: Sulfamethoxazole; Water Pollutants, Chemical; Wastewater; Anti-Bacterial Agents; Bacteria; Micrococcaceae; Biodegradation, Environmental; DNA
PubMed: 38424602
DOI: 10.1186/s40168-023-01741-5