Recent progress in glycomics and proteomics of the Q fever bacterium Coxiella burnetii

Abstract

Coxiella burnetii is an intracellular, Gram-negative bacterium and causative agent of Q fever. In humans, the disease ranges mostly from a flu-like illness and self-recovering mild pneumonia to severe meningoencephalitis, myocarditis or endocarditis. Recent molecular and biochemical/immunological advances, along with improved instrumentation, have provided unique insight into the host-parasite interrelationship and revealed previously unknown virulence strategies of C. burnetii. Noticeable progress has also been achieved in gaining a better understanding of the role of two major outer membrane components - lipopolysaccharide (LPS) and proteins in the life and immunopathobiology of the bacterium. Detailed glycomic studies have brought indispensable structural and functional information on LPS and its role in pathogenesis and immunity of Q fever. Recent proteomic studies have brought a deeper insight into the pathogen`s physiology, virulence and development and offered new possibilities in the investigation of inter/intra-species variation. This review will focus on advances in glycomics and proteomics of C. burnetii providing information on unique glycan and protein species, which together with other findings in the field, might lead to both a better understanding of this unusual pathogen and improvements in Q fever diagnosis and therapy.

Protein composition of the phase I Coxiella burnetii soluble antigen prepared by extraction with trichloroacetic acid

“…Interestingly, four of them may have moonlighting activity. All these proteins have been previously reported in other studies (Flores-Ramirez et al, 2017;Papadioti et al, 2011;Sekeyova et al, 2009;Beare et al, 2008;Jian et al, 2014, Toman et al, 2013. These include the general markers for Q fever chaperones 60 kDa (Groel) and the chaperonin dnaK ( Xiong et al 2012) as well as the virulent factors (ompH and Mip), markers for acute Q fever (the omp's AdA and com1), and another stress protein with moonlighting activity (superoxide dismutase [Fe] sodB) that are involved in pathogenesis and pathogenicity (Flores-Ramirez et al, 2014;Skultety et al, 2011).…”

Comparison of Three Serologic Tests for the Detection of Anti-Coxiella burnetii Antibodies in Patients with Q Fever

“…Serology is a primordial diagnostic method to investigate diseases of lower occurrence or underestimated because it allows broad and rapid testing of the population with a lower cost than that proposed by other diagnostic techniques [5]. However, this type of diagnosis is usually used more often in patients with more than seven days of symptoms, the time required for seroconversion, or in epidemiological investigations [6]. For the diagnosis of Q fever, indirect immunofluorescence (IFA) is the most recommended test because it Pathogens 2023, 12, 873 2 of 8 is more sensitive and specific for the detection of the agent from human samples, while ELISA is the most sensitive and specific test for detection in animal samples [7,8].…”

“…Therefore, this is the best class of immunoglobulins to investigate in patients with suspected acute disease [4]. In the absence of PCR diagnosis and in the impossibility of establishing a paired serum analysis, a single positive convalescent serum sample (stage II ≥ 1:128) in a patient who has been ill for more than seven days indicates probable acute infection [6]. A study by França et al [3] showed that patients with two and three weeks of symptoms were 2.12 and 2.62 times more likely to be seropositive, respectively, than patients with one week of symptoms.…”

Identification ofCoxiella burnetiisurface-exposed and cell envelope associated proteins using a combined bioinformatics plus proteomics strategy

“…Understanding the surface proteome of C. burnetii is of special importance because it can reveal the complexity of biological processes taking place at the interface between the bacterium and the external milieu . These environment‐accessible, surface‐exposed and cell envelope associated proteins (SECEP), are not only involved in the uptake of nutrients and the release of waste, but they also support physical interactions of the bacteria with living surfaces and serve as sensors for extracellular signals .…”