1
|
Eldin C, Mélenotte C, Mediannikov O, Ghigo E, Million M, Edouard S, Mege JL, Maurin M, Raoult D. From Q Fever to Coxiella burnetii Infection: a Paradigm Change. Clin Microbiol Rev 2017; 30:115-190. [PMID: 27856520 PMCID: PMC5217791 DOI: 10.1128/cmr.00045-16] [Citation(s) in RCA: 539] [Impact Index Per Article: 77.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Coxiella burnetii is the agent of Q fever, or "query fever," a zoonosis first described in Australia in 1937. Since this first description, knowledge about this pathogen and its associated infections has increased dramatically. We review here all the progress made over the last 20 years on this topic. C. burnetii is classically a strict intracellular, Gram-negative bacterium. However, a major step in the characterization of this pathogen was achieved by the establishment of its axenic culture. C. burnetii infects a wide range of animals, from arthropods to humans. The genetic determinants of virulence are now better known, thanks to the achievement of determining the genome sequences of several strains of this species and comparative genomic analyses. Q fever can be found worldwide, but the epidemiological features of this disease vary according to the geographic area considered, including situations where it is endemic or hyperendemic, and the occurrence of large epidemic outbreaks. In recent years, a major breakthrough in the understanding of the natural history of human infection with C. burnetii was the breaking of the old dichotomy between "acute" and "chronic" Q fever. The clinical presentation of C. burnetii infection depends on both the virulence of the infecting C. burnetii strain and specific risks factors in the infected patient. Moreover, no persistent infection can exist without a focus of infection. This paradigm change should allow better diagnosis and management of primary infection and long-term complications in patients with C. burnetii infection.
Collapse
Affiliation(s)
- Carole Eldin
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Cléa Mélenotte
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Oleg Mediannikov
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Eric Ghigo
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Matthieu Million
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Sophie Edouard
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Jean-Louis Mege
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Max Maurin
- Institut de Biologie et de Pathologie, CHU de Grenoble, Grenoble, France
| | - Didier Raoult
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| |
Collapse
|
2
|
Jaing CJ, McLoughlin KS, Thissen JB, Zemla A, Gardner SN, Vergez LM, Bourguet F, Mabery S, Fofanov VY, Koshinsky H, Jackson PJ. Identification of Genome-Wide Mutations in Ciprofloxacin-Resistant F. tularensis LVS Using Whole Genome Tiling Arrays and Next Generation Sequencing. PLoS One 2016; 11:e0163458. [PMID: 27668749 PMCID: PMC5036845 DOI: 10.1371/journal.pone.0163458] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/08/2016] [Indexed: 11/19/2022] Open
Abstract
Francisella tularensis is classified as a Class A bioterrorism agent by the U.S. government due to its high virulence and the ease with which it can be spread as an aerosol. It is a facultative intracellular pathogen and the causative agent of tularemia. Ciprofloxacin (Cipro) is a broad spectrum antibiotic effective against Gram-positive and Gram-negative bacteria. Increased Cipro resistance in pathogenic microbes is of serious concern when considering options for medical treatment of bacterial infections. Identification of genes and loci that are associated with Ciprofloxacin resistance will help advance the understanding of resistance mechanisms and may, in the future, provide better treatment options for patients. It may also provide information for development of assays that can rapidly identify Cipro-resistant isolates of this pathogen. In this study, we selected a large number of F. tularensis live vaccine strain (LVS) isolates that survived in progressively higher Ciprofloxacin concentrations, screened the isolates using a whole genome F. tularensis LVS tiling microarray and Illumina sequencing, and identified both known and novel mutations associated with resistance. Genes containing mutations encode DNA gyrase subunit A, a hypothetical protein, an asparagine synthase, a sugar transamine/perosamine synthetase and others. Structural modeling performed on these proteins provides insights into the potential function of these proteins and how they might contribute to Cipro resistance mechanisms.
Collapse
Affiliation(s)
- Crystal J. Jaing
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
- * E-mail:
| | - Kevin S. McLoughlin
- Computations Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - James B. Thissen
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Adam Zemla
- Computations Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Shea N. Gardner
- Computations Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Lisa M. Vergez
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Feliza Bourguet
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Shalini Mabery
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | | | | | - Paul J. Jackson
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| |
Collapse
|
3
|
D’Amato F, Eldin C, Raoult D. The contribution of genomics to the study of Q fever. Future Microbiol 2016; 11:253-72. [DOI: 10.2217/fmb.15.137] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Coxiella burnetii is the etiological agent of Q fever, a worldwide zoonosis that can result in large outbreaks. The birth of genomics and sequencing of C. burnetii strains has revolutionized many fields of study of this infection. Accurate genotyping methods and comparative genomic analysis have enabled description of the diversity of strains around the world and their link with pathogenicity. Genomics has also permitted the development of qPCR tools and axenic culture medium, facilitating the diagnosis of Q fever. Moreover, several pathophysiological mechanisms can now be predicted and therapeutic strategies can be determined thanks to in silico genome analysis. An extensive pan-genomic analysis will allow for a comprehensive view of the clonal diversity of C. burnetii and its link with virulence.
Collapse
Affiliation(s)
- Felicetta D’Amato
- Aix-Marseille Université, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS 7278, IRD 198, INSERM 1095, Marseille, France
| | - Carole Eldin
- Aix-Marseille Université, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS 7278, IRD 198, INSERM 1095, Marseille, France
| | - Didier Raoult
- Aix-Marseille Université, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS 7278, IRD 198, INSERM 1095, Marseille, France
| |
Collapse
|
4
|
Vranakis I, De Bock PJ, Papadioti A, Tselentis Y, Gevaert K, Tsiotis G, Psaroulaki A. Identification of Potentially Involved Proteins in Levofloxacin Resistance Mechanisms in Coxiella burnetii. J Proteome Res 2010; 10:756-62. [DOI: 10.1021/pr100906v] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Iosif Vranakis
- Department of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Medical School, University of Crete, GR-71110 Heraklion, Greece, Department of Medical Protein Research, VIB, B-9000 Ghent, Belgium, Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium, and Division of Biochemistry, Department of Chemistry, University of Crete, P.O. Box 2208, GR-71003 Voutes, Greece
| | - Pieter-Jan De Bock
- Department of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Medical School, University of Crete, GR-71110 Heraklion, Greece, Department of Medical Protein Research, VIB, B-9000 Ghent, Belgium, Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium, and Division of Biochemistry, Department of Chemistry, University of Crete, P.O. Box 2208, GR-71003 Voutes, Greece
| | - Anastasia Papadioti
- Department of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Medical School, University of Crete, GR-71110 Heraklion, Greece, Department of Medical Protein Research, VIB, B-9000 Ghent, Belgium, Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium, and Division of Biochemistry, Department of Chemistry, University of Crete, P.O. Box 2208, GR-71003 Voutes, Greece
| | - Yannis Tselentis
- Department of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Medical School, University of Crete, GR-71110 Heraklion, Greece, Department of Medical Protein Research, VIB, B-9000 Ghent, Belgium, Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium, and Division of Biochemistry, Department of Chemistry, University of Crete, P.O. Box 2208, GR-71003 Voutes, Greece
| | - Kris Gevaert
- Department of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Medical School, University of Crete, GR-71110 Heraklion, Greece, Department of Medical Protein Research, VIB, B-9000 Ghent, Belgium, Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium, and Division of Biochemistry, Department of Chemistry, University of Crete, P.O. Box 2208, GR-71003 Voutes, Greece
| | - Georgios Tsiotis
- Department of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Medical School, University of Crete, GR-71110 Heraklion, Greece, Department of Medical Protein Research, VIB, B-9000 Ghent, Belgium, Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium, and Division of Biochemistry, Department of Chemistry, University of Crete, P.O. Box 2208, GR-71003 Voutes, Greece
| | - Anna Psaroulaki
- Department of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, Medical School, University of Crete, GR-71110 Heraklion, Greece, Department of Medical Protein Research, VIB, B-9000 Ghent, Belgium, Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium, and Division of Biochemistry, Department of Chemistry, University of Crete, P.O. Box 2208, GR-71003 Voutes, Greece
| |
Collapse
|
5
|
Vranakis I, Sandalakis V, Chochlakis D, Tselentis Y, Psaroulaki A. DNA gyrase and topoisomerase IV mutations in an in vitro fluoroquinolone-resistant Coxiella burnetii strain. Microb Drug Resist 2010; 16:111-7. [PMID: 20438350 DOI: 10.1089/mdr.2010.0015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The etiological agent of Q fever, Coxiella burnetii, is an obligate intracellular bacterium that multiplies within a vacuole with lysosomal characteristics. Quinolones have been used as an alternative therapy for Q fever. In this study, quinolone-resistance-determining regions of the genes coding for DNA gyrase and topoisomerase IV were analyzed by DNA sequencing from an in vitro fluoroquinolone-resistant C. burnetii strain (Q212). Sequencing and aligning of DNA gyrase encoding genes (gyrA and gyrB) and topoisomerase IV genes (parC and parE) revealed one gyrA mutation leading to the amino acid substitution Asp87Gly (Escherichia coli numbering), two gyrB mutations leading to the amino acid substitutions Ser431Pro and Met518Ile, and three parC mutations leading to the amino acid substitutions Asp69Asn, Thr80Ile, and Gly104Ser. The corresponding alignment of the C. burnetii Q212 reference strain, the in vitro developed fluoroquinolone-resistant C. burnetii Q212 strain, and E. coli resulted in the identification of several other naturally occurring mutations within and outside the quinolone-resistance-determining regions of C. burnetii providing indications of possible natural resistance to fluoroquinolones. The present study adds additional potential mutations in the DNA topoisomerases that may be involved in fluoroquinolone resistance in C. burnetii due to their previous characterization in other bacterial species.
Collapse
Affiliation(s)
- Iosif Vranakis
- Laboratory of Clinical Bacteriology, Parasitology, Zoonoses, and Geographical Medicine (WHO Collaborating Center), Medical School, University of Crete, Heraklion, Greece
| | | | | | | | | |
Collapse
|
6
|
Angelakis E, Raoult D. Q fever. Vet Microbiol 2010; 140:297-309. [DOI: 10.1016/j.vetmic.2009.07.016] [Citation(s) in RCA: 434] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Revised: 07/03/2009] [Accepted: 07/30/2009] [Indexed: 01/17/2023]
|
7
|
Almahmoud I, Kay E, Schneider D, Maurin M. Mutational paths towards increased fluoroquinolone resistance in Legionella pneumophila. J Antimicrob Chemother 2009; 64:284-93. [PMID: 19474069 DOI: 10.1093/jac/dkp173] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Fluoroquinolone resistance has been poorly studied in Legionella pneumophila, an intracellular pathogen responsible for legionellosis. Our goal was to further characterize molecular mechanisms involved in fluoroquinolone resistance in this species. METHODS Eight independent lineages were founded from a common fluoroquinolone-susceptible L. pneumophila ancestor and propagated by serial passages in moxifloxacin-containing culture medium. We identified the substituted mutations that affected the DNA topoisomerase II-encoding genes, determined the order of substitution of the mutations leading to the stepwise MIC increases of moxifloxacin over evolutionary time and demonstrated their direct involvement in the resistance process. RESULTS Adaptation occurred through parallel stepwise increases in the moxifloxacin MICs up to 512-fold the MIC for the parental strain. Mutations affected the topoisomerase II-encoding genes gyrA, parC and gyrB, reflecting a high degree of genetic parallelism across the independent lineages. During evolution, the T83I change in GyrA occurred first, followed by G78D or S80R in ParC and D87N in GyrA, or S464Y or D426N in GyrB. By constructing isogenic strains, we showed that the progressive increase in resistance was linked to a precise order of mutation substitution, but also to the co-existence of several subpopulations of bacteria bearing different mutations. CONCLUSIONS Specific mutational trajectories were identified, strongly suggesting that intermolecular epistatic interactions between DNA topoisomerases underlie the mechanism of fluoroquinolone resistance in L. pneumophila. Our results suggest that L. pneumophila has strong potential to become resistant to fluoroquinolone compounds and warrant further investigation of resistance in clinical and environmental strains of this pathogen.
Collapse
Affiliation(s)
- Iyad Almahmoud
- Laboratoire Adaptation et Pathogénie des Micro-organismes, Université Joseph Fourier Grenoble 1, Institut Jean Roget, Campus Santé, Domaine de la Merci, BP 170, F-38042 Grenoble cedex 9, France
| | | | | | | |
Collapse
|
8
|
Biswas S, Raoult D, Rolain JM. A bioinformatic approach to understanding antibiotic resistance in intracellular bacteria through whole genome analysis. Int J Antimicrob Agents 2008; 32:207-20. [PMID: 18619818 DOI: 10.1016/j.ijantimicag.2008.03.017] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Accepted: 03/19/2008] [Indexed: 12/17/2022]
Abstract
Intracellular bacteria survive within eukaryotic host cells and are difficult to kill with certain antibiotics. As a result, antibiotic resistance in intracellular bacteria is becoming commonplace in healthcare institutions. Owing to the lack of methods available for transforming these bacteria, we evaluated the mechanisms of resistance using molecular methods and in silico genome analysis. The objective of this review was to understand the molecular mechanisms of antibiotic resistance through in silico comparisons of the genomes of obligate and facultative intracellular bacteria. The available data on in vitro mutants reported for intracellular bacteria were also reviewed. These genomic data were analysed to find natural mutations in known target genes involved in antibiotic resistance and to look for the presence or absence of different resistance determinants. Our analysis revealed the presence of tetracycline resistance protein (Tet) in Bartonella quintana, Francisella tularensis and Brucella ovis; moreover, most of the Francisella strains possessed the blaA gene, AmpG protein and metallo-beta-lactamase family protein. The presence or absence of folP (dihydropteroate synthase) and folA (dihydrofolate reductase) genes in the genome could explain natural resistance to co-trimoxazole. Finally, multiple genes encoding different efflux pumps were studied. This in silico approach was an effective method for understanding the mechanisms of antibiotic resistance in intracellular bacteria. The whole genome sequence analysis will help to predict several important phenotypic characteristics, in particular resistance to different antibiotics. In the future, stable mutants should be obtained through transformation methods in order to demonstrate experimentally the determinants of resistance in intracellular bacteria.
Collapse
Affiliation(s)
- Silpak Biswas
- URMITE UMR 6236, CNRS IRD, Faculté de Médecine et de Pharmacie, Université de la Méditerranée, 27 Bd Jean Moulin, 13385 Marseille Cedex 05, France
| | | | | |
Collapse
|
9
|
Marrie TJ. Empiric treatment of ambulatory community-acquired pneumonia: always include treatment for atypical agents. Infect Dis Clin North Am 2005; 18:829-41. [PMID: 15555827 PMCID: PMC7118999 DOI: 10.1016/j.idc.2004.07.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
There are no data from proper studies to answer whether it is necessary to include antibiotics that are active against atypical pneumonia agents as part of the empiric therapy of CAP. Until such data are available, clinical judgment and severity of the pneumonic illness are the best guides to empiric antimicrobial therapy.
Collapse
Affiliation(s)
- Thomas J Marrie
- 2J2.00 Walter C. Mackenzie Health Sciences Centre, 8440 112th Street, Edmonton, Alberta T6G 2R7, Canada.
| |
Collapse
|
10
|
Abstract
PURPOSE OF REVIEW In this era of emerging infectious diseases and bioterrorism it is important to be up to date with the diagnosis and management of Q fever pneumonia. RECENT FINDINGS A considerable amount of new information has emerged regarding the pathogenesis of Coxiella burnetii infection. The complete genome of this microorganism has now been sequenced and there are several unique features. The spectrum of manifestations of infection due to C. burnetii continues to expand. Some of the more recently described findings are acalculous cholecystitis, rhabdomyolysis, long-term persistence of Coxiella, post Q fever fatigue syndrome, and hemolytic uremic syndrome. Pneumonia as a manifestation of acute Q fever shows tremendous geographic variation, being common in one area of a country such as Spain but not in another area. SUMMARY Pneumonia continues to be an important manifestation of infection with C. burnetii. It responds to treatment with doxycycline, quinolones or macrolides.
Collapse
Affiliation(s)
- Thomas J Marrie
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
| |
Collapse
|
11
|
Spyridaki I, Psaroulaki A, Aransay A, Scoulica E, Tselentis Y. Diagnosis of quinolone-resistant Coxiella burnetii strains by PCR-RFLP. J Clin Lab Anal 2000; 14:59-63. [PMID: 10683615 PMCID: PMC6807793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
A total of 12 strains of Coxiella burnetii (8 Greek isolates from acute Q-fever patients, two reference strains-Nine Mile and Q212-and two pefloxacin-resistant laboratory strains) were examined for the presence of point mutations in the quinolone resistance determining region (QRDR) of gyrA gene by direct DNA sequencing of the polymerase chain reaction (PCR)-amplified fragments. The gene sequences of all eight Greek isolates and the two reference strains Nine Mile and Q212 [minimal inhibitory concentration (MIC)</= 4 microg/ml] were identical. Direct DNA sequencing of the in vitro-selected resistant strains (MICs to pefloxacin, 8-32 microg/ml) revealed a transition (G-->A) at the corresponding codon 87 of E. coli. This mutation lead to the substitution of Glu (codon GAG) by Lys (codon AAG ). Restriction maps of amplified gyrA gene sequences were determined by GCG Wisconsin PACKAGE, and the MnlI restriction enzyme was found to cut only the sensitive strains sequences and not the resistant ones. The present PCR-RFLP analysis has proved to be a simple, rapid, and useful method for the detection of Coxiella burnetii and, at the same time, for the diagnosis of quinolone-resistant Coxiella burnetii strains.
Collapse
Affiliation(s)
- I Spyridaki
- Department of Bacteriology, Parasitology, Zoonoses, and Geographical Medicine, Faculty of Medicine, University of Crete, Crete, Greece.
| | | | | | | | | |
Collapse
|
12
|
Spyridaki I, Psaroulaki A, Aransay A, Scoulica E, Tselentis Y. Diagnosis of quinolone-resistantCoxiella burnetii strains by PCR-RFLP. J Clin Lab Anal 2000. [DOI: 10.1002/(sici)1098-2825(2000)14:2<59::aid-jcla4>3.0.co;2-p] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
13
|
Abstract
Q fever is a zoonosis with a worldwide distribution with the exception of New Zealand. The disease is caused by Coxiella burnetii, a strictly intracellular, gram-negative bacterium. Many species of mammals, birds, and ticks are reservoirs of C. burnetii in nature. C. burnetii infection is most often latent in animals, with persistent shedding of bacteria into the environment. However, in females intermittent high-level shedding occurs at the time of parturition, with millions of bacteria being released per gram of placenta. Humans are usually infected by contaminated aerosols from domestic animals, particularly after contact with parturient females and their birth products. Although often asymptomatic, Q fever may manifest in humans as an acute disease (mainly as a self-limited febrile illness, pneumonia, or hepatitis) or as a chronic disease (mainly endocarditis), especially in patients with previous valvulopathy and to a lesser extent in immunocompromised hosts and in pregnant women. Specific diagnosis of Q fever remains based upon serology. Immunoglobulin M (IgM) and IgG antiphase II antibodies are detected 2 to 3 weeks after infection with C. burnetii, whereas the presence of IgG antiphase I C. burnetii antibodies at titers of >/=1:800 by microimmunofluorescence is indicative of chronic Q fever. The tetracyclines are still considered the mainstay of antibiotic therapy of acute Q fever, whereas antibiotic combinations administered over prolonged periods are necessary to prevent relapses in Q fever endocarditis patients. Although the protective role of Q fever vaccination with whole-cell extracts has been established, the population which should be primarily vaccinated remains to be clearly identified. Vaccination should probably be considered in the population at high risk for Q fever endocarditis.
Collapse
Affiliation(s)
- M Maurin
- Unité des Rickettsies, CNRS UPRES A 6020, Université de la Méditerranée, Faculté de Médecine, 13385 Marseilles Cedex 5, France
| | | |
Collapse
|
14
|
Dessus-Babus S, Bébéar CM, Charron A, Bébéar C, de Barbeyrac B. Sequencing of gyrase and topoisomerase IV quinolone-resistance-determining regions of Chlamydia trachomatis and characterization of quinolone-resistant mutants obtained In vitro. Antimicrob Agents Chemother 1998; 42:2474-81. [PMID: 9756744 PMCID: PMC105861 DOI: 10.1128/aac.42.10.2474] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The L2 reference strain of Chlamydia trachomatis was exposed to subinhibitory concentrations of ofloxacin (0.5 microg/ml) and sparfloxacin (0.015 microg/ml) to select fluoroquinolone-resistant mutants. In this study, two resistant strains were isolated after four rounds of selection. The C. trachomatis mutants presented with high-level resistance to various fluoroquinolones, particularly to sparfloxacin, for which a 1,000-fold increase in the MICs for the mutant strains compared to the MIC for the susceptible strain was found. The MICs of unrelated antibiotics (doxycycline and erythromycin) for the mutant strains were identical to those for the reference strain. The gyrase (gyrA, gyrB) and topoisomerase IV (parC, parE) genes of the susceptible and resistant strains of C. trachomatis were partially sequenced. A point mutation was found in the gyrA quinolone-resistance-determining region (QRDR) of both resistant strains, leading to a Ser83-->Ile substitution (Escherichia coli numbering) in the corresponding protein. The gyrB, parC, and parE QRDRs of the resistant strains were identical to those of the reference strain. These results suggest that in C. trachomatis, DNA gyrase is the primary target of ofloxacin and sparfloxacin.
Collapse
Affiliation(s)
- S Dessus-Babus
- Laboratoire de Bactériologie, Université Bordeaux 2, 33076 Bordeaux Cedex, France
| | | | | | | | | |
Collapse
|
15
|
Willems H, Jäger C, Baljer G. Physical and genetic map of the obligate intracellular bacterium Coxiella burnetii. J Bacteriol 1998; 180:3816-22. [PMID: 9683477 PMCID: PMC107364 DOI: 10.1128/jb.180.15.3816-3822.1998] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Pulsed-field gel electrophoresis and PCR techniques have been used to construct a NotI macrorestriction map of the obligate intracellular bacterium Coxiella burnetii Nine Mile. The size of the chromosome has been determined to be 2,103 kb comprising 29 NotI restriction fragments. The average resolution is 72.5 kb, or about 3. 5% of the genome. Experimental data support the presence of a linear chromosome. Published genes were localized on the physical map by Southern hybridization. One gene, recognized as transposable element, was found to be present in at least nine sites evenly distributed over the whole chromosome. There is only one copy of a 16S rRNA gene. The putative oriC has been located on a 27.5-kb NotI fragment. Gene organization upstream the oriC is almost identical to that of Pseudomonas putida and Bacillus subtilis, whereas gene organization downstream the oriC seems to be unique among bacteria. The physical map will be helpful in investigations of the great heterogeneity in restriction fragment length polymorphism patterns of different isolates and the great variation in genome size. The genetic map will help to determine whether gene order in different isolates is conserved.
Collapse
Affiliation(s)
- H Willems
- Institute of Hygiene and Infectious Diseases of Animals, Justus-Liebig-Universität Giessen, D-35392 Giessen, Germany.
| | | | | |
Collapse
|
16
|
Kim JH, Cho EH, Kim KS, Kim HY, Kim YM. Cloning and nucleotide sequence of the DNA gyrase gyrA gene from Serratia marcescens and characterization of mutations in gyrA of quinolone-resistant clinical isolates. Antimicrob Agents Chemother 1998; 42:190-3. [PMID: 9449286 PMCID: PMC105481 DOI: 10.1128/aac.42.1.190] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The sequence of the DNA gyrase gyrA gene of Serratia marcescens ATCC 14756 was determined. An open reading frame of 2,640 nucleotides coding for a polypeptide with a calculated molecular mass of 97,460 was found, and its sequence complemented the sequence of an Escherichia coli gyrA temperature-sensitive mutation. Analysis of the PCR products of the quinolone resistance-determining regions of gyrA genes from six quinolone-resistant clinical isolates revealed a single amino acid substitution, Ser-83 to Arg or Asp-87 to Tyr, in all six mutants, suggesting that a mutational alteration in gyrA is a common mechanism of quinolone resistance in S. marcescens.
Collapse
Affiliation(s)
- J H Kim
- Department of Pharmacology and Molecular Biology, C&C Research Laboratories, Kyunggi-do, Korea
| | | | | | | | | |
Collapse
|
17
|
|