Occurrence and Genotyping of Coxiella burnetii in Hedgehogs in China.

Coxiella burnetii is the causative agent of query fever (Q fever), and distributes broadly in environment. Livestock are identified as main reservoirs, which may infect people through their contaminative urine, feces, milk, and birth products. Wild animals can also be the potential carriers and transmitters of C. burnetii. To understand the geographic distribution and host species of C. burnetii in China, we investigated the prevalence of C. burnetii in hedgehogs (Erinaceus amurensis) in Hubei Province. Hedgehogs were tested for C. burnetii with PCR targeting three genes (com1, rrs, and icd) followed by multispacer sequence typing (MST). We found that 12.2% (5/41) hedgehogs were PCR positive for C. burnetii. MST revealed presence of two novel genotypes and phylogenetic analysis revealed that the strains were similar to a group of isolates from chronic Q fever patients and mammals. This study showed that C. burnetii are highly prevalent in hedgehogs in Hubei Province in central China, suggesting that hedgehogs may play an important role in the ecology and transmission of C. burnetii to humans because it is captured and used as traditional medicine in China.

Complementation of Arginine Auxotrophy for Genetic Transformation of Coxiella burnetii by Use of a Defined Axenic Medium.

UNLABELLED: Host cell-free (axenic) culture of Coxiella burnetii in acidified citrate cysteine medium-2 (ACCM-2) has provided important opportunities for investigating the biology of this naturally obligate intracellular pathogen and enabled the development of tools for genetic manipulation. However, ACCM-2 has complex nutrient sources that preclude a detailed study of nutritional factors required for C. burnetii growth. Metabolic reconstruction of C. burnetii predicts that the bacterium cannot synthesize all amino acids and therefore must sequester some from the host. To examine C. burnetii amino acid auxotrophies, we developed a nutritionally defined medium with known amino acid concentrations, termed ACCM-D. Compared to ACCM-2, ACCM-D supported longer logarithmic growth, a more gradual transition to stationary phase, and approximately 5- to 10-fold greater overall replication. Small-cell-variant morphological forms generated in ACCM-D also showed increased viability relative to that generated in ACCM-2. Lack of growth in amino acid-deficient formulations of ACCM-D revealed C. burnetii auxotrophy for 11 amino acids, including arginine. Heterologous expression of Legionella pneumophila argGH in C. burnetii permitted growth in ACCM-D missing arginine and supplemented with citrulline, thereby providing a nonantibiotic means of selection of C. burnetii genetic transformants. Consistent with bioinformatic predictions, the elimination of glucose did not impair C. burnetii replication. Together, these results highlight the advantages of a nutritionally defined medium in investigations of C. burnetii metabolism and the development of genetic tools. IMPORTANCE: Host cell-free growth and genetic manipulation of Coxiella burnetii have revolutionized research of this intracellular bacterial pathogen. Nonetheless, undefined components of growth medium have made studies of C. burnetii physiology difficult and have precluded the development of selectable markers for genetic transformation based on nutritional deficiencies. Here, we describe a medium, containing only amino acids as the sole source of carbon and energy, which supports robust growth and improved viability of C. burnetii Growth studies confirmed that C. burnetii cannot replicate in medium lacking arginine. However, genetic transformation of the bacterium with constructs containing the last two genes in the L. pneumophila arginine biosynthesis pathway (argGH) allowed growth on defined medium missing arginine but supplemented with the arginine precursor citrulline. Our results advance the field by facilitating studies of C. burnetii metabolism and allowing non-antibiotic-based selection of C. burnetii genetic transformants, an important achievement considering that selectable makers based on antibiotic resistance are limited.

Maternofetal consequences of Coxiella burnetii infection in pregnancy: a case series of two outbreaks.

BACKGROUND: A high complication rate of Q fever in pregnancy is described on the basis of a limited number of cases. All pregnant women with proven Q fever regardless of clinical symptoms should therefore receive long-term cotrimoxazole therapy. But cotrimoxazole as a folic acid antagonist may cause harm to the fetus. We therefore investigated the Q fever outbreaks, Soest in 2003 and Jena in 2005, to determine the maternofetal consequences of Coxiella burnetii infection contracted during pregnancy. METHODS: Different outbreak investigation strategies were employed at the two sides. Antibody screening was performed with an indirect immunofluorescence test. Medical history and clinical data were obtained and serological follow up performed at delivery. Available placental tissue, amniotic fluid and colostrum/milk were further investigated by polymerase chain reaction and by culture. RESULTS: 11 pregnant women from Soest (screening rate: 49%) and 82 pregnant women from Jena (screening rate: 27%) participated in the outbreak investigation. 11 pregnant women with an acute C. burnetii infection were diagnosed. Three women had symptomatic disease. Three women, who were infected in the first trimester, were put on long-term therapy. The remaining women received cotrimoxazole to a lesser extent (n=3), were treated with macrolides for three weeks (n=1) or after delivery (n=1), were given no treatment at all (n=2) or received antibiotics ineffective for Q fever (n=1). One woman and her foetus died of an underlying disease not related to Q fever. One woman delivered prematurely (35th week) and one child was born with syndactyly. We found no obvious association between C. burnetii infection and negative pregnancy outcome. CONCLUSIONS: Our data do not support the general recommendation of long-term cotrimoxazole treatment for Q fever infection in pregnancy. Pregnant women with symptomatic C. burnetii infections and with chronic Q fever should be treated. The risk-benefit ratio of treatment in these patients, however, remains uncertain. If cotrimoxazole is administered, folinic acid has to be added.

Coxiella burnetii, the agent of Q fever in Brazil: its hidden role in seronegative arthritis and the importance of molecular diagnosis based on the repetitive element IS1111 associated with the transposase gene.

Coxiella burnetii is the agent of Q fever , an emergent worldwide zoonosis of wide clinical spectrum. Although C. burnetii infection is typically associated with acute infection, atypical pneumonia and flu-like symptoms, endocarditis, osteoarticular manifestations and severe disease are possible, especially when the patient has a suppressed immune system; however, these severe complications are typically neglected. This study reports the sequencing of the repetitive element IS1111 of the transposase gene of C. burnetii from blood and bronchoalveolar lavage (BAL) samples from a patient with severe pneumonia following methotrexate therapy, resulting in the molecular diagnosis of Q fever in a patient who had been diagnosed with active seronegative polyarthritis two years earlier. To the best of our knowledge, this represents the first documented case of the isolation of C. burnetii DNA from a BAL sample.

Coxiella burnetii, the agent of Q fever in Brazil: its hidden role in seronegative arthritis and the importance of molecular diagnosis based on the repetitive element IS1111 associated with the transposase gene

Coxiella burnetii is the agent of Q fever , an emergent worldwide zoonosis of wide clinical spectrum. Although C. burnetii infection is typically associated with acute infection, atypical pneumonia and flu-like symptoms, endocarditis, osteoarticular manifestations and severe disease are possible, especially when the patient has a suppressed immune system; however, these severe complications are typically neglected. This study reports the sequencing of the repetitive element IS1111 of the transposase gene of C. burnetii from blood and bronchoalveolar lavage (BAL) samples from a patient with severe pneumonia following methotrexate therapy, resulting in the molecular diagnosis of Q fever in a patient who had been diagnosed with active seronegative polyarthritis two years earlier. To the best of our knowledge, this represents the first documented case of the isolation of C. burnetii DNA from a BAL sample.

Investigations concerning the prevalence of Coxiella burnetii and Chlamydia abortus in sheep in correlation with management systems and abortion rate in Lower Saxony in 2004.

The intracellular bacteria Coxiella (C) burnetii and Chlamydia (Chl) abortus induce abortion in sheep and also affect humans. While Chl. abortus only infrequently infects humans, C burnetii is the aetiological agent of numerous Q fever outbreaks during the last decades. There is only limited knowledge about the prevalence of both pathogens in sheep, although sheep are involved in almost all Q fever outbreaks in Germany. The aim of our study was to investigate the prevalence of both pathogens in flocks located in Lower Saxony, Germany, in correlation to the management form and abortion rate. Serum samples of 1714 sheep from 95 flocks located in Lower Saxony were investigated by ELISA. 2.7% of these samples were positive, 1.3% showed inconclusive results in the C. burnetii-ELISA. Elevated intra-flock seroprevalences were only detected in three migrating flocks. Chlamydia-specific antibodies could be detected in 15.1% serum samples of mainly shepherded and migrating flocks. In one of these flocks with a high intra-flock seroprevalence for C burnetii (27%) and Chlamydia (44.9%), C burnetii was detected in 21.6% of the placenta samples of normal births and in 12.5% of the colostrum samples by PCR. Aborted fetuses and the corresponding placentas were negative in C burnetii-PCR, but in most of them and also in many other placenta samples Chl. abortus could be detected by PCR and DNA microarray. This survey shows a low overall prevalence of C. burnetii in sheep in Lower Saxony in the year 2004. However, three migrating flocks with a high intra-flock prevalence are localized in the southern parts of Lower Saxony. Spreading of C burnetii could occur, because of the large radius of grazing of all three flocks.