A novel variant of Chlamydia psittaci causing human psittacosis in China.

From January 2022 to November 2022, sporadic psittacosis occurred in Lishui city, China. The patients were presented with fever, cough, and pulmonary infiltration. Their clinical symptoms were not relieved after receiving cephalosporin, penicillin, beta-lactamase inhibitors, and quinolones.

Distribution characteristics of the CRISPR-Cas system and its regulatory mechanism underpinning phenotypic function.

is a common intracellular parasitic bacterium that infects humans via the respiratory tract, causing Legionnaires' disease, with fever and pneumonia as the main symptoms. The emergence of highly virulent and azithromycin-resistant is a major challenge in clinical anti-infective therapy. The CRISPR-Cas acquired immune system provides immune defense against foreign nucleic acids and regulates strain biological functions.

Diversity of Rickettsiales bacteria in five species of ticks collected from Jinzhai County, Anhui Province, China in 2021-2022.

The order Rickettsiales in the class Alphaproteobacteria comprises vector-borne pathogens of both medical and veterinary importance. Ticks, as a group, are second only to mosquitoes as vectors of pathogens to humans, playing a critical role in the transmission of rickettsiosis. In the present study, 880 ticks collected from Jinzhai County, Lu'an City, Anhui Province, China in 2021-2022 were identified as belonging to five species from three genera.

Clinical Forms of Japanese Spotted Fever from Case-Series Study, Zigui County, Hubei Province, China, 2021.

We report a case-series study of 5 patients with Japanese spotted fever from the Three Gorges Area in China, including 1 fatal case. Seroprevalence of Rickettsia japonica was ≈21% among the local population. Our report highlights the emerging potential threat to human health of Japanese spotted fever in the area.

A protein-protein interaction map reveals that the Coxiella burnetii effector CirB inhibits host proteasome activity.

Coxiella burnetii is the etiological agent of the zoonotic disease Q fever, which is featured by its ability to replicate in acid vacuoles resembling the lysosomal network. One key virulence determinant of C. burnetii is the Dot/Icm system that transfers more than 150 effector proteins into host cells.

Development of a Lateral Flow Strip-Based Recombinase-Aided Amplification for Active Infection.

is the causative agent of psittacosis, a worldwide zoonotic disease. A rapid, specific, and sensitive diagnostic assay would be benefit for infection control. In this study, an assay combining recombinase-aided amplification and a lateral flow strip (RAA-LF) for the detection of active infection was developed.

Novel genotypes of Coxiella burnetii circulating in rats in Yunnan Province, China.

Background: Coxiella burnetii (Cb) is the causative agent of the zoonotic disease Q fever which is distributed worldwide. Molecular typing of Cb strains is essential to find out the infectious source and prevent Q fever outbreaks, but there has been a lack of typing data for Cb strains in China. The aim of this study was to investigate the genotypes of Cb strains in wild rats in Yunnan Province, China.

Coxiella burnetii Plasmid Effector B Promotes LC3-II Accumulation and Contributes To Bacterial Virulence in a SCID Mouse Model.

Coxiella burnetii, the causative agent of zoonotic Q fever, is characterized by replicating inside the lysosome-derived -containing vacuole (CCV) in host cells. Some effector proteins secreted by C. burnetii have been reported to be involved in the manipulation of autophagy to facilitate the development of CCVs and bacterial replication.

Identification of Tick-Borne Pathogens and Genotyping of in in Yunnan Province, China.

, a vector that can transmit many pathogens to humans and domestic animals, is widely distributed in Yunnan province, China. However, few reports on the prevalence of tick-borne pathogens (TBPs) in in Yunnan are available. The aim of this study was to detect TBPs in in Yunnan and to analyze the phylogenetic characterization of TBPs detected in these ticks.

The epidemic of Q fever in 2018 to 2019 in Zhuhai city of China determined by metagenomic next-generation sequencing.

Q fever is a worldwide zoonosis caused by Coxiella burnetii (Cb). From January 2018 to November 2019, plasma samples from 2,382 patients with acute fever of unknown cause at a hospital in Zhuhai city of China were tested using metagenomic next-generation sequencing (mNGS). Of those tested, 138 patients (5.

Identification of tick-borne pathogens by metagenomic next-generation sequencing in Dermacentor nuttalli and Ixodes persulcatus in Inner Mongolia, China.

Background: Hard ticks act as arthropod vectors in the transmission of human and animal pathogens and are widely distributed in northern China. The aim of this study is to screen the important tick-borne pathogens (TBPs) carried by hard ticks in Inner Mongolia using metagenomic next-generation sequencing (mNGS) and to estimate the risk of human infection imposed by tick bites.

Methods: The adult Dermacentor nuttalli (n = 203) and Ixodes persulcatus (n = 36) ticks feeding on cattle were collected.

Construction of a Live-Attenuated Vaccine Strain of EV76-B-SHUΔ and Evaluation of Its Protection Efficacy in a Mouse Model by Aerosolized Intratracheal Inoculation.

Plague, which is caused by , is one of the most dangerous infectious diseases. No FDA-approved vaccine against plague is available for human use at present. To improve the immune safety of EV76 based live attenuated vaccine and to explore the feasibility of aerosolized intratracheal inoculation (i.

Development and evaluation of an up-converting phosphor technology-based lateral flow assay for rapid and quantitative detection of Coxiella burnetii phase I strains.

Background: Coxiella burnetii is an obligate intracellular Gram-negative bacterium that causes a zoonotic disease commonly called Q fever globally. In this study, an up-converting phosphor technology-based lateral flow (UPT-LF) assay was established for the rapid and specific detection of phase I strains of C. burnetii.

Pathologic changes and immune responses against Coxiella burnetii in mice following infection via non-invasive intratracheal inoculation.

Q fever is a worldwide zoonosis caused by Coxiella burnetii. Human Q fever is typically acquired through inhalation of contaminated aerosols, resulting in an initial pulmonary infection. In this study, BALB/c mice were infected with C.

Th1 epitope peptides induce protective immunity against Rickettsia rickettsii infection in C3H/HeN mice.

Rickettsia rickettsii is the causative pathogen of Rocky Mountain spotted fever (RMSF). Adr2, YbgF and OmpB are protective antigens of R. rickettsii.

Retrospective Examination of Q Fever Endocarditis: An Underdiagnosed Disease in the Mainland of China.

Background: Q fever endocarditis, a chronic illness caused by Coxiella burnetii, can be fatal if misdiagnosed or left untreated. Despite a relatively high positive rate of Q fever serology in healthy individuals in the mainland of China, very few cases of Q fever endocarditis have been reported. This study summarized cases of Q fever endocarditis among blood culture negative endocarditis (BCNE) patients and discussed factors attributing to the low diagnostic rate.

Identification of Coxiella burnetii CD8+ T-Cell Epitopes and Delivery by Attenuated Listeria monocytogenes as a Vaccine Vector in a C57BL/6 Mouse Model.

Coxiella burnetii is a gram-negative bacterium that causes acute and chronic Q fever. Because of the severe adverse effect of whole-cell vaccination, identification of immunodominant antigens of C. burnetii has become a major focus of Q fever vaccine development.

Enhanced Expression of T-Cell Immunoglobulin and Mucin Domain Protein 3 in Endothelial Cells Facilitates Intracellular Killing of Rickettsia heilongjiangensis.

Rickettsia heilongjiangensis is the pathogen of Far eastern spotted fever, and T-cell immunoglobulin and mucin domain protein 3 (Tim-3) is expressed in human vascular endothelial cells, the major target cells of rickettsiae. In the present study, we investigated the effects of altered Tim-3 expression in vivo in mice and in vitro in human endothelial cells, on day 3 after R. heilongjiangensis infection.

Protection conferred by virus-like particle vaccines against respiratory syncytial virus infection in mice by intranasal vaccination.

Respiratory syncytial virus (RSV) is a major pathogen in infants and the elderly, causing pneumonia and bronchiolitis. Despite decades of research, to date there is still no approved RSV vaccine available. In this study, we developed RSV virus-like particle (VLP) vaccines containing an RSV fusion (F) and/or attachment (G) protein with Newcastle disease virus (NDV) as the platform.

Chloroform-Methanol Residue of Coxiella burnetii Markedly Potentiated the Specific Immunoprotection Elicited by a Recombinant Protein Fragment rOmpB-4 Derived from Outer Membrane Protein B of Rickettsia rickettsii in C3H/HeN Mice.

The obligate intracellular bacteria, Rickettsia rickettsii and Coxiella burnetii, are the potential agents of bio-warfare/bio-terrorism. Here C3H/HeN mice were immunized with a recombinant protein fragment rOmp-4 derived from outer membrane protein B, a major protective antigen of R. rickettsii, combined with chloroform-methanol residue (CMR) extracted from phase I C.