Frontiers in Cellular and Infection Microbiology最新文献

Therapies that modulate and appropriately direct the immune response are promising candidates for the treatment of infectious diseases. One such candidate therapeutic is DZ13, a short, synthetic, single-stranded DNA molecule. This molecule has enzymatic activity and can modulate the immune response by binding to and degrading the mRNA encoding a key immuno-regulatory molecule. Originally developed and entering clinical trials as an anti-cancer agent, DZ13 has also been evaluated as a treatment for viral infections, and has been shown to provide protection against infection with influenza virus in a mouse model of infection. In this work, we evaluated whether the immuno-modulatory properties of DZ13 could provide protection against the potential biothreat pathogen Burkholderia pseudomallei which causes the neglected tropical disease melioidosis. Treatment of mice infected with B. pseudomallei demonstrated that DZ13 did indeed provide excellent protection after only two post-exposure treatments. However, our data indicated that the enzymatic activity contained in DZ13 was not required for protection, with control oligonucleotide treatments lacking activity against the target mRNA equally as protective against B. pseudomallei. We have designed new sequences to study the mechanism of protection further. These novel sequences offer enhanced protection against infection, but are not directly anti-microbial and do not appear to be stimulating the immune system via TLR9 or other key innate immune sensors, despite containing CpG motifs. The molecular mechanism of these novel sequences remains to be elucidated, but the data highlights that these oligonucleotide-sensing pathways are attractive and relevant targets to modulate during bacterial and viral infections.

Clostridioides difficile strains of sequence type (ST) 37, primarily including PCR ribotype (RT) 017, are prevalent in mainland China. Our study aimed to compare the major virulence factors of an epidemic C. difficile isolate of ST37 type (Xy06) from China with the well-characterized C. difficile reference strains R20291 (RT027) and CD630E (ST54), as well as a Chinese ST54 strain (Xy07) isolated from the same hospital. The Xy06 genome was predicted to harbor two complete prophages and several transposon-like elements. Comparative analysis of PaLoc revealed a truncated tcdA gene, a functional tcdB gene, a functional tcdC gene, and well-conserved tcdR and tcdE genes. Phenotypic comparisons showed that Xy06 was a robust producer of TcdB, readily sporulated and germinated, and strongly bound to human gut epithelial cells. In a mouse model of C. difficile infection, Xy06 was more virulent than strains CD630E and Xy07 and was comparable to strain R20291 in virulence. Our data suggest the potential threat of the epidemic ST37 strains in China.

Objectives: This study describes the detection and tracking of emergency neurosurgical cross-transmission infections with carbapenem-resistant Klebsiella oxytoca (CRKO).

Methods: We conducted an epidemiological investigation and a rapid screening of 66 surveillance samples using the chromogenic selective medium. Two CRKO isolates from infected patients and three from the preoperative shaving razors had similar resistance profiles identified by the clinical laboratory.

Results: The whole genome sequencing (WGS) results identified all isolates as Klebsiella michiganensis (a species in the K. oxytoca complex) with sequence type 29 (ST29) and carrying resistance genes bla _KPC-2 and bla _OXY-5, as well as IncF plasmids. The pairwise average nucleotide identity values of 5 isolates ranged from 99.993% to 99.999%. Moreover, these isolates displayed a maximum genetic difference of 3 among 5,229 targets in the core genome multilocus sequence typing scheme, and the razors were confirmed as the contamination source. After the implementation of controls and standardized shaving procedures, no new CRKO infections occurred.

Conclusion: Contaminated razors can be sources of neurosurgical site infections with CRKO, and standard shaving procedures need to be established. Chromogenic selective medium can help rapidly identify targeted pathogens, and WGS technologies are effective mean in tracking the transmission source in an epidemic or outbreak investigation. Our findings increase the understanding of microbial transmission in surgery to improve patient care quality.

Introduction: Getah virus (GETV) is a multi-host virus found in pigs, horses, and blue foxes. Clinically, GETV can cause fever, diarrhea, and reproductive disorders in pigs, representing significant threats to pig breeding. At present, few studies have examined the pathogenicity of GETV in pigs of different ages.

Methods: In the present study, a new strain, named GETV-QJ, was isolated from clinically ill pigs, and whole genome sequencing analysis was performed. Besides the pathogenicity of piglets and pregnant sows of this strain was further studied.

Results: the results illustrated that the strain belonged to group III. The strain had 93.6%-96.3% homology with other subtypes, and its homology with the same subtype strain ranged 96.5%-99%. Further studies on the pathogenicity of the virus indicated that this strain caused severe diarrhea, fever, and intestinal and lung damage in 7-day-old piglets, resulting in their death. The piglet survival rate was 0%. In pregnant sows, this strain did not cause fever, death, or abortion, but it induced viremia, which affected the farrowing performance of sows and led to reduced piglet survival.

Discussion: In this study, we isolated a highly virulent group III and comprehensively established a pathogenic model of GETV in piglets and sows, providing a reference and guidance for the prevention and control of this infection.

We present a patient with a post-pneumonectomy empyema refractory to surgical debridement and systemic antibiotics. The patient initially presented with a bronchopleural fistula and pneumothorax secondary to tuberculosis (TB) destroyed lung, which required a pneumonectomy with Eloesser flap. Ongoing pleural infection delayed the closure of the Eloesser flap, and thoracoscopic inspection of his chest cavity revealed a green, mucous biofilm-like structure lining the postpneumonectomy pleural cavity. Cultures identified pan-susceptible Pseudomonas aeruginosa. Despite debriding this biofilm-like structure and administering systemic antibiotics, the patient continued to show persistent signs of infection and regrowth of the film. We employed a novel approach to dissolve the biofilm-like structure using intrapleural dornase alfa followed by intrapleural antibiotic washes. After 3 weeks of daily washes, repeat inspection demonstrated the biofilm-like structure had completely resolved. Resolving the pseudomonas biofilm-like structure allowed permanent closure of his chest without further need for systemic antibiotics. At follow up 3 months later, he showed no sequalae. This treatment option can be an important adjunct to improve likelihood of chest closure in patients with post-pneumonectomy empyema that resists standard treatment options due to biofilm formation.

Background: This article employs bibliometric methods and visual maps to delineate the research background, collaborative relationships, hotspots, and trends in the study of gut fungi in human diseases and health.

Methods: Publications related to human gut fungi were retrieved from the Web of Science Core Collection. VOSviewer, CiteSpace, R software and Microsoft Excel were employed to generate visual representations illustrating the contributions made by countries/regions, authors, organizations, and journals. Employing VOSviewer and CiteSpace, we conducted a comprehensive analysis of the retrieved publications, revealing underlying tendencies, research hotspots, and intricate knowledge networks.

Results: This study analyzed a total of 3,954 publications. The United States ranks first in the number of published papers and has the highest number of citations and h-index. Mostafa S Elshahed is the most prolific author. The University of California System is the institution that published the most papers. Frontiers In Microbiology is the journal with the largest number of publications. Three frequently co-cited references have experienced a citation burst lasting until 2024.

Conclusion: Advancements in sequencing technologies have intensified research into human gut fungi and their health implications, shifting the research focus from gut fungal infections towards microbiome science. Inflammatory bowel diseases and Candida albicans have emerged as pivotal areas of interest in this endeavor. Through this study, we have gained a deeper insight into global trends and frontier hotspots within this field, thereby enhancing our understanding of the intricate relationship between gut fungi and human health.

This study investigated the effects of Enterococcus hirae (Eh) derived from Ningxiang pigs on growth performance, diarrhea incidence, and immune responses in ETEC-challenged piglets. The results showed that compared to the CON group, ETEC infection significantly reduced the average daily gain (ADG) and average daily feed intake (ADFI), increased rectal temperature, and resulted in a diarrhea rate of up to 24%. Additionally, ETEC infection significantly increased the spleen index and the expression of inflammatory cytokines in the spleen, serum and intestine, with decreasing serum sIgA and colonic SCFAs of piglets. Compared to the ETEC group, orally Eh significantly increased ADFI in ETEC-infected piglets, reduced the diarrhea rate to 11.53%, reduced the spleen index and the expression of inflammatory cytokines in the spleen, serum and intestine, with decreasing serum sIgA and colonic SCFAs of ETEC-infected piglets. Furthermore, correlation analysis revealed that the levels of SCFAs (particularly acetate) were significantly negatively correlated with the expression levels of inflammatory cytokines in colonic and splenic tissues, suggesting that acetate may be a key metabolite in the anti-inflammatory effects of Eh. These results indicate that Eh can enhance the protection of piglets against ETEC K88 via intestine-acetate-spleen axis, thereby alleviating diarrhea and improving growth performance in piglets.

[This corrects the article DOI: 10.3389/fcimb.2023.1270667.].