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Tidsskrift For Den Norske Laegeforening... Aug 2021The diagnosis of pulmonary tularaemia can be challenging. We present a case illustrating how pulmonary tularaemia may be an important radiological differential diagnosis...
BACKGROUND
The diagnosis of pulmonary tularaemia can be challenging. We present a case illustrating how pulmonary tularaemia may be an important radiological differential diagnosis to lung cancer.
CASE PRESENTATION
A man in his fifties presented with several weeks of dry cough, weight loss and profuse night sweats. The physical examination was normal. A chest computer tomography showed evidence of lymphadenopathy and two consolidated lung masses. The lung masses and lymph nodes showed signs of necrosis. The radiological findings were described as suspicious of lung cancer. A detailed history revealed that he had chopped wood prior to symptom onset. He tested positive for Francisella tularensis IgM and IgG, confirming the diagnosis of pulmonary tularaemia.
INTERPRETATION
The radiological findings in pulmonary tularaemia may mimic lung cancer. Serology is an easy way to confirm the diagnosis, if faced with clinical or radiological suspicion of pulmonary tularaemia.
Topics: Antibodies, Bacterial; Cough; Diagnosis, Differential; Francisella tularensis; Humans; Lung Neoplasms; Male; Tularemia
PubMed: 34423953
DOI: 10.4045/tidsskr.21.0245 -
Virulence Dec 2023Tularaemia is a zoonotic disease caused by the Gram-negative bacterium, . Depending on its entry route into the organism, causes different diseases, ranging from... (Review)
Review
Tularaemia is a zoonotic disease caused by the Gram-negative bacterium, . Depending on its entry route into the organism, causes different diseases, ranging from life-threatening pneumonia to less severe ulceroglandular tularaemia. Various strains with different geographical distributions exhibit different levels of virulence. is an intracellular bacterium that replicates primarily in the cytosol of the phagocytes. The main virulence attribute of is the type 6 secretion system (T6SS) and its effectors that promote escape from the phagosome. In addition, has evolved a peculiar envelope that allows it to escape detection by the immune system. In this review, we cover tularaemia, different strains, and their pathogenicity. We particularly emphasize the intracellular life cycle, associated virulence factors, and metabolic adaptations. Finally, we present how largely escapes immune detection to be one of the most infectious and lethal bacterial pathogens.
Topics: Humans; Francisella tularensis; Virulence; Tularemia; Virulence Factors; Phagosomes
PubMed: 37941380
DOI: 10.1080/21505594.2023.2274638 -
Annual Review of Entomology Jan 2020Tularemia is a Holarctic zoonosis caused by the gamma proteobacterium and is considered to be a vector-borne disease. In many regions, human risk is associated with the... (Review)
Review
Tularemia is a Holarctic zoonosis caused by the gamma proteobacterium and is considered to be a vector-borne disease. In many regions, human risk is associated with the bites of flies, mosquitoes, or ticks. But the biology of the agent is such that risk may be fomite related, and large outbreaks can occur due to inhalation or ingestion of contaminated materials. Such well-documented human risk factors suggest a role for these risk factors in the enzootic cycle as well. Many arthropods support the growth or survival of the agent, but whether arthropods (ticks in particular) are obligately required for the perpetuation of remains to be demonstrated. As with most zoonoses, our knowledge of the ecology of has been driven with the objective of understanding human risk. In this review, we focus on the role of the arthropod in maintaining , particularly with respect to long-term enzootic persistence.
Topics: Animals; Arthropod Vectors; Biological Evolution; Francisella tularensis; Tularemia
PubMed: 31600457
DOI: 10.1146/annurev-ento-011019-025134 -
Microorganisms Dec 2020(Ft) is the etiological agent of tularemia, a disease known for over 100 years in the northern hemisphere. Ft includes four subspecies, of which two are the etiologic... (Review)
Review
(Ft) is the etiological agent of tularemia, a disease known for over 100 years in the northern hemisphere. Ft includes four subspecies, of which two are the etiologic agents of tularemia: Ft subsp. (Ftt) and Ft subsp. (Fth), mainly distributed in North America and the whole northern hemisphere, respectively. Several routes of human infection with these bacteria exist, notably through bites of Ixodidae ticks. However, mosquitoes represent the main vectors of Fth in Scandinavia, where large tularemia outbreaks have occurred, usually during the warm season. The mechanisms making mosquitoes vectors of Fth are still unclear. This review covers the inventory of research work and epidemiological data linking tularemia to mosquitoes in Scandinavia and highlights the gaps in understanding mosquitoes and Ft interactions.
PubMed: 33374861
DOI: 10.3390/microorganisms9010026 -
Frontiers in Cellular and Infection... 2020Tularemia is a zoonotic disease caused by the bacterium . The predominant sources, routes of infection, and clinical manifestations of human infections greatly vary... (Review)
Review
Tularemia is a zoonotic disease caused by the bacterium . The predominant sources, routes of infection, and clinical manifestations of human infections greatly vary according to the geographic area considered. Moreover, clinical suspicion of tularemia is often tricky because of the lack of specificity of the clinical manifestations. Because isolation is tedious and detection of its DNA usually requires removal of infected tissues, serological techniques are most often used for diagnostic confirmation. However, these techniques are varied and poorly standardized. The microagglutination test (MAT), the indirect immunofluorescence assay (IFA), and ELISA tests are currently the most frequently used techniques. These home-made and commercial tests are mainly used for tularemia diagnosis but also seroprevalence studies. ELISA tests detect specific antibodies within two weeks of disease evaluation, compared to 2-3 weeks for MAT and IFA. However, more false-positive results are usually reported with ELISA. The long-term persistence of anti- antibodies in patients with past tularemia infection hampers the diagnostic specificity of all these tests. Also, cross-reacting antibodies have been described (especially with and species), although usually at a low level. The immunoblotting technique can highlight these serological cross-reactions. Tularemia remains an underdiagnosed disease in most endemic areas, and the clinical presentations of this disease are evolving. It is necessary to improve further speed and accuracy of tularemia diagnosis, as well as the standardization of diagnostic procedures.
Topics: Adolescent; Adult; Animals; Antibodies, Bacterial; Child; Female; Francisella tularensis; Humans; Male; Middle Aged; Seroepidemiologic Studies; Tularemia; Young Adult; Zoonoses
PubMed: 33194778
DOI: 10.3389/fcimb.2020.512090 -
Frontiers in Cellular and Infection... 2017, the causative agent of tularemia, is a Gram-negative bacterium that infects a variety of cell types including macrophages, and propagates with great efficiency in the... (Review)
Review
, the causative agent of tularemia, is a Gram-negative bacterium that infects a variety of cell types including macrophages, and propagates with great efficiency in the cytoplasm. Iron, essential for key enzymatic and redox reactions, is among the nutrients required to support this pathogenic lifestyle and the bacterium relies on specialized mechanisms to acquire iron within the host environment. Two distinct pathways for iron acquisition are encoded by the genome- a siderophore-dependent ferric iron uptake system and a ferrous iron transport system. Genes of the Fur-regulated operon direct the production and transport of the siderophore rhizoferrin. Siderophore biosynthesis involves enzymes FslA and FslC, while export across the inner membrane is mediated by FslB. Uptake of the rhizoferrin- ferric iron complex is effected by the siderophore receptor FslE in the outer membrane in a TonB-independent process, and FslD is responsible for uptake across the inner membrane. Ferrous iron uptake relies largely on high affinity transport by FupA in the outer membrane, while the Fur-regulated FeoB protein mediates transport across the inner membrane. FslE and FupA are paralogous proteins, sharing sequence similarity and possibly sharing structural features as well. This review summarizes current knowledge of iron acquisition in this organism and the critical role of these uptake systems in bacterial pathogenicity.
Topics: Animals; Biological Transport; Disease Models, Animal; Ferric Compounds; Ferrous Compounds; Francisella tularensis; Humans; Iron; Metabolic Networks and Pathways; Virulence
PubMed: 28421167
DOI: 10.3389/fcimb.2017.00107 -
Annals of Agricultural and... Mar 2022Tularaemia is an infrequently occurring disease in Poland. It has therefore rarely been taken into account in the differential diagnosis of skin lesions, lymphadenitis,... (Review)
Review
INTRODUCTION AND OBJECTIVE
Tularaemia is an infrequently occurring disease in Poland. It has therefore rarely been taken into account in the differential diagnosis of skin lesions, lymphadenitis, or soft tissue abscesses. This fact, accompanied by non-specific initial presentation, may lead to a delay in diagnosis and a more severe course of the disease. Objective. The aim of the study is to present the current state of knowledge on tularaemia and convince medical professionals to take it into consideration in the diagnosis of skin lesions, lymphadenitis, and tissue abscesses.
REVIEW METHODS
A literature review using PubMed and other online resources, using terms including 'tularaemia', 'lymphadenitis', etc., was undertaken. Papers were reviewed for relevance and scientific merit.
ABBREVIATED DESCRIPTION OF THE STATE OF KNOWLEDGE
Tularaemia, also known as 'rabbit fever', is a zoonotic infection caused by Francisella tularensis, an aerobic, facultative intracellular, gram-negative bacteria. In Europe, it is mainly spread via tick bites and contact with wild animals such as lagomorphs and rodents. Clinical presentation may differ depending on the transmission route; the ulceroglandular and glandular forms of disease predominate. An early diagnosis and implementation of appropriate antibiotic therapy are the cornerstones of successful treatment and make it possible to avoid a surgical incision and drainage of suppurative complications.
SUMMARY
Raised awareness and knowledge on tularaemia among health care professionals are required for timely diagnosis and treatment. Arrival from endemic areas, contact with wild animals, tick bites, and exclusion of more common etiologies of presenting signs should prompt consideration of tularaemia. More research is needed for a better understanding of the burden of the disease and its impact on public health in Poland.
Topics: Animals; Anti-Bacterial Agents; Europe; Francisella tularensis; Rabbits; Tularemia; Zoonoses
PubMed: 35352900
DOI: 10.26444/aaem/139242 -
Frontiers in Cellular and Infection... 2018Tularemia, also known as "rabbit fever," is a zoonosis caused by the facultative intracellular, gram-negative bacterium . Infection occurs through contact with infected... (Review)
Review
Tularemia, also known as "rabbit fever," is a zoonosis caused by the facultative intracellular, gram-negative bacterium . Infection occurs through contact with infected animals (often hares), arthropod vectors (such as ticks or deer flies), inhalation of contaminated dust or through contaminated food and water. In this review, we would like to provide an overview of the current epidemiological situation in Germany using published studies and case reports, an analysis of recent surveillance data and our own experience from the laboratory diagnostics, and investigation of cases. While in Germany tularemia is a rarely reported disease, there is evidence of recent re-emergence. We also describe some peculiarities that were observed in Germany, such as a broad genetic diversity, and a recently discovered new genus of and protracted or severe clinical courses of infections with the subspecies . Because tularemia is a zoonosis, we also touch upon the situation in the animal reservoir and one-health aspects of this disease. Apparently, many pieces of the puzzle need to be found and put into place before the complex interaction between wildlife, the environment and humans are fully understood. Funding for investigations into rare diseases is scarce. Therefore, combining efforts in several countries in the framework of international projects may be necessary to advance further our understanding of this serious but also scientifically interesting disease.
Topics: Animals; Disease Outbreaks; Francisella tularensis; Geography; Germany; History, 20th Century; History, 21st Century; Humans; Population Surveillance; Tularemia; Zoonoses
PubMed: 29503812
DOI: 10.3389/fcimb.2018.00040 -
Frontiers in Cellular and Infection... 2019Bacteria alter gene expression in response to changes in their environment through various mechanisms that include signal transduction systems. These signal transduction... (Review)
Review
Bacteria alter gene expression in response to changes in their environment through various mechanisms that include signal transduction systems. These signal transduction systems use membrane histidine kinase with sensing domains to mediate phosphotransfer to DNA-binding proteins that alter the level of gene expression. Such regulators are called two-component systems (TCSs). TCSs integrate external signals and information from stress pathways, central metabolism and other global regulators, thus playing an important role as part of the overall regulatory network. This review will focus on the knowledge of TCSs in the Gram-negative bacterium, , a biothreat agent with a wide range of potential hosts and a significant ability to cause disease. While TCSs have been well-studied in several bacterial pathogens, they have not been well-studied in non-model organisms, such as and its subspecies, whose canonical TCS content surprisingly ranges from few to none. Additionally, of those TCS genes present, many are orphan components, including KdpDE, QseC, QseB/PmrA, and an unnamed two-component system (FTN_1452/FTN_1453). We discuss recent advances in this field related to the role of TCSs in physiology and pathogenesis and compare the TCS genes present in human virulent versus. environmental species and subspecies of .
Topics: Animals; Bacterial Proteins; DNA-Binding Proteins; Francisella tularensis; Gene Expression Regulation, Bacterial; Histidine Kinase; Humans; Protein Domains; Signal Transduction; Tularemia; Virulence
PubMed: 31263682
DOI: 10.3389/fcimb.2019.00198 -
Folia Microbiologica Feb 2021Tularemia is a bacterial disease of humans, wild, and domestic animals. Francisella tularensis, which is a Gram-negative coccobacillus-shaped bacterium, is the causative... (Review)
Review
Tularemia is a bacterial disease of humans, wild, and domestic animals. Francisella tularensis, which is a Gram-negative coccobacillus-shaped bacterium, is the causative agent of tularemia. Recently, an increase in the number of human tularemia cases has been noticed in several countries around the world. It has been reported mostly from North America, several Scandinavian countries, and certain Asian countries. The disease spreads through vectors such as mosquitoes, horseflies, deer flies, and ticks. Humans can acquire the disease through direct contact of sick animals, consumption of infected animals, drinking or direct contact of contaminated water, and inhalation of bacteria-loaded aerosols. Low infectious dose, aerosol route of infection, and its ability to induce fatal disease make it a potential agent of biological warfare. Tularemia leads to several clinical forms, such as glandular, ulceroglandular, oculoglandular, oropharyngeal, respiratory, and typhoidal forms. The disease is diagnosed through the use of culture, serology, or molecular methods. Quinolones, tetracyclines, or aminoglycosides are frequently used in the treatment of tularemia. No licensed vaccine is available in the prophylaxis of tularemia and this is need of the time and high-priority research area. This review mostly focuses on general features, importance, current status, and preventive measures of this disease.
Topics: Animals; Anti-Bacterial Agents; Biological Warfare Agents; Communicable Diseases, Emerging; Disease Transmission, Infectious; Francisella tularensis; Humans; Tick-Borne Diseases; Tularemia
PubMed: 32989563
DOI: 10.1007/s12223-020-00827-z