Q fever pneumonia in children in Japan

Epidemiological Investigation of Tick-Borne Bacterial Pathogens in Domestic Animals from the Qinghai-Tibetan Plateau Area, China

The Qinghai-Tibetan Plateau area (QTPA) features a unique environment that has witnessed the selective breeding of diverse breeds of domestic livestock exhibiting remarkable adaptability. Nevertheless, Anaplasma spp., Rickettsia spp., Coxiella spp., and Borrelia spp. represent tick-borne bacterial pathogens that pose a global threat and have substantial impacts on both human and animal health, as well as on the economy of animal husbandry within the Qinghai-Tibetan plateau area. In this study, a total of 428 samples were systematically collected from 20 distinct areas within the Qinghai Plateau. The samples included 62 ticks and 366 blood samples obtained from diverse animal species to detect the presence of Anaplasma spp., Rickettsia spp., Coxiella spp., and Borrelia spp. The prevalence of infection in this study was determined as follows: Anaplasma bovis accounted for 16.4% (70/428), A. capra for 4.7% (20/428), A. ovis for 5.8% (25/428), Borrelia burgdorferi sensu lato for 6.3% (27/428), Coxiella burnetii for 0.7% (3/428), and Rickettsia spp. for 0.5% (2/428). Notably, no cases of A. marginale and A. phagocytophilum infections were observed in this study. The findings revealed an elevated presence of these pathogens in Tibetan sheep and goats, with no infections detected in yaks, Bactrian camels, donkeys, and horses. To the best of our knowledge, this study represents the first investigation of tick-borne bacterial pathogens infecting goats, cattle, horses, and donkeys within the Qinghai Plateau of the Qinghai-Tibetan Plateau area. Consequently, our findings contribute valuable insights into the distribution and genetic diversity of Anaplasma spp., Rickettsia spp., Coxiella spp., and Borrelia spp. within China.

Tick populations and molecular detection of selected tick-borne pathogens in questing ticks from northern and central Tanzania

Ticks are vectors and reservoirs of a variety of pathogens including protozoa, bacteria and viruses which cause tick-borne diseases (TBDs) in humans and livestock. TBDs pose serious constraints to the improvement of livestock production in tropical and subtropical regions of the world. Despite their wide distribution, information on the tick and pathogen relationship is scarce in Tanzania. We used nested PCR and sequencing to screen pathogens of public and veterinary health importance in ticks collected by flagging from four districts of Tanzania. In total, 2021 ticks comprising nine species were identified. DNA from ticks was pooled according to tick species, developmental stage, and location, then screened for Babesia bigemina, Babesia bovis, Theileria parva and Coxiella burnetii. Out of 377 pools, 34.7% were positive for at least one pathogen. Theileria parva was the most abundant with a minimum infection rate (MIR) of 2.8%, followed by B. bigemina (MIR = 1.8%) and B. bovis (MIR = 0.8%). Multiple pathogens detection was observed in 7.2% of the tested pools. However, PCR screening of individual tick DNA revealed that only 0.3% of the examined pools had co-infection. DNA of C. burnetii was never detected in any tick DNA pool. The MIR of tick-borne pathogens (TBPs) differed significantly among districts, seasons, tick species, and tick developmental stages. Sequence analysis showed that B. bigemina RAP-1a, B. bovis SBP-4, and T. parva p104 genes were conserved among pathogens in the four districts. Despite the absence of C. burnetii in ticks, considering its pathogenic potential, it is essential to continue monitoring for its possible recurrence in ticks. This information adds to the knowledge of TBPs epidemiology and will contribute to the scientific basis for planning future control strategies.

Molecular Analysis With 16S rRNA PCR/Sanger Sequencing and Molecular Antibiogram Performed on DNA Extracted From Valve Improve Diagnosis and Targeted Therapy of Infective Endocarditis: A Prospective Study

BACKGROUND

Molecular analysis (MA) on heart valve (HV) improves the microbiologic diagnosis of infectious endocarditis (IE). The main drawback of MA is the lack of antimicrobial susceptibility information.

METHODS

We conducted a prospective cohort observational study of consecutive adult patients from April 2012 to May 2021 who underwent valve surgery at our hospital. The performance of MA, blood cultures (BC) and valve cultures (VC), and the diagnostic and therapeutic impact of MA were evaluated. Molecular antibiogram results were compared to culture-based antimicrobial susceptibility testing (AST).

RESULTS

A total of 137 patients with definite IE and 52 patients with no IE were enrolled in the study. Among IE cases BC, VC, and MA were positive in 75 (55%), 30 (22%), and 120 (88%) of IE cases, respectively. Among 62 cases of BC-negative IE (BCNE), 57 achieved diagnosis with MA. MA led to a change of antimicrobial therapy in 92% of BCNE. MA was negative in 100% of patients with no IE. Molecular antibiogram performed on 17 valve specimens that resulted positive for pathogens potential carrier of genes encoding for multidrug resistant mechanisms showed 100% concordance with AST.

CONCLUSIONS

MA showed a high specificity and sensitivity in etiological diagnosis of IE. Molecular antibiogram could overcome the major limitation of MA that is the lack of susceptibility testing. We advocate for the inclusion of MA among diagnostic criteria for IE and for a more extensive use of molecular antibiogram when the culture result is negative, and MA is the only positive test.

Bidimensional and Contrast-Enhanced Ultrasonography of the Spleen in Dogs Affected by Leishmaniosis

Simple Summary

Canine leishmaniosis is responsible for pathological changes in the spleen. The main features detectable from ultrasound examination are splenomegaly and diffuse alterations of the echostructure. The study aimed to highlight whether these ultrasound changes are related to the severity of the disease or to a modification of splenic microvascularization that can be detected in vivo through contrast-enhanced ultrasonography. Bidimensional ultrasonography showed that splenomegaly and diffuse parenchymal changes were positively correlated with the severity of the disease, so they could be of prognostic value. Contrast-enhanced ultrasonography showed that a persistent heterogeneous distribution pattern appeared only in spleens with diffuse echostructure alterations, and quantitative parameters regarding volume and velocity of flow in three regions of interest did not show any differences between affected and control dogs. Diffuse splenic microvascular modifications evidenced by contrast-enhanced ultrasonography were reported for the first time in dogs with canine leishmaniosis.

Abstract

Canine leishmaniosis (CanL) is responsible for splenic pathological changes. The main features detectable from ultrasound examination are splenomegaly and diffuse alterations of the echostructure. The study aimed to highlight whether these ultrasound changes are related to the severity of the disease or to a modification of splenic microvascularization that can be detected in vivo through contrast-enhanced ultrasonography (CEUS). Twenty-five adult dogs tested for CanL were enrolled in this prospective, controlled study and staged according to LeishVet guidelines. Bidimensional ultrasonography revealed that splenomegaly was seen in 50% of the affected dogs, and diffuse parenchymal changes were seen in more than 60% of dogs with splenomegaly, showing a positive correlation with severity of the disease; therefore, splenomegaly could be of prognostic significance. CEUS showed that a persistent heterogeneous distribution pattern appeared only in spleens with diffuse echostructure alterations. The evaluation of quantitative CEUS parameters regarding the volume and velocity of flow in three regions of interest did not show differences between affected and control dogs. Diffuse spleen microvascular modifications evidenced by CEUS were reported for the first time in dogs with CanL. In endemic areas, CanL could be included in the differential diagnoses list when detecting splenic alterations in dogs.

Molecular Investigation on Tick-Borne Hemoparasites and Coxiella burnetii in Dromedary Camels (Camelusdromedarius) in Al Dhafra Region of Abu Dhabi, UAE

Camels represent an important resource for inhabitants of the most arid regions of the world and their survival is mainly related to environment conditions including the risk of parasitic diseases, which may represent a significant cause of losses in livestock production of these areas. Camels may be parasitized by several hematophagous arthropods, which can be vectors of several diseases including zoonosis. This study aimed to investigate in dromedary camels and their ticks the importance of tick-borne hemoparasites that might be responsible for a recent and obscure morbidity of camels in Al Dhafra region of Abu Dhabi, UAE. Blood samples and ticks from 93 naturally infected camels belonging to 36 herds, affected by variable acute clinical syndromes lasting from 3 to 5 days, were analyzed through molecular techniques for specific DNA presence of different blood pathogens: Anaplasmamarginale/Anaplasmaovis, Anaplasma phagocytophilum, Coxiella burnetii,Babesia spp., and Theileria spp. DNA. All the 72 ticks collected belonged to the Hyalomma dromedarii species and were negative for blood pathogens. n = 15 camels (16.1%) were found positive to the following tick-borne hemoparasites: A. phagocytophilum 11 (11.8%), Coxiella burnetii 3 (3.2%), and Babesia/Theileria spp. 2 (2.1%). One singular camel showed coinfection of C. burnetii and A. phagocytophiulm. Genetic profile of C. burnetii showed a high phylogenetic relatedness to European, Asian and African C. burnetii strains. This is the first laboratory investigation on tick-borne pathogens in camels in UAE, and the first report of A. phagocytophilum and C. burnetii. Moreover, since the detected pathogens are recognized pathogens for humans, this study highlights the zoonotic risk for humans working in camel husbandry.

First isolation and molecular phylogenetic analysis of Coxiella burnetii in lactating cows

Q fever is an infectious disease of animals and humans, caused by globally distributed C. burnetii. In Iraq, there are no previous studies associated with the detection of the organism in cattle. An overall of 130 lactating cows were submitted to direct collection of milk samples. Initially, the samples of milk were tested using the molecular polymerase chain reaction (PCR) assay targeting three genes (16S rRNA, IS1111a transposase, and htpB). However, positive results (18.46%; 24/130) were detected only with the 16s rRNA gene. Concerning risk factors, the highest prevalence of C. burnetii was showed in the district of Badra (42.86%), whereas the lowest - in Al-Numaniyah and Al-Suwaira districts (P=0.025). There was no significant variation in positivity between the months of sampling period (P=0.082) and between age groups (P=0.076). Crossbred cows (20.69%) showed a higher positivity than local and pure breeds (P=0.043). Milk of positive samples (n=24) was used for cultivation of C. burnetii into specific pathogen free-embryonated chicken eggs (SPF-ECEs). After three passages into SPF-ECEs, contents of yolk sac were collected, subjected for DNA extraction, and re-tested by PCR assay using the primer of 16s rRNA gene only. Of 24 cultivated milk samples, 12.5% (3/24) were positive for C. burnetii. Finally, the positive local isolates were analysed phylogenetically and reported in NCBI-Genbank under the accession numbers of MN121700.1, MN121701.1, and MN121702.1. In conclusion, this is a unique study as it detected C. burnetii in Iraqi lactating cows, and confirmed that organism was shed actively through milk, suggesting that these animals can play a role as a reservoir for organism with potential risk for transmission of infection from these animals to humans as well as to other animal species.

Molecular detection and genetic characterization of the potentially pathogenic Coxiella burnetii and the endosymbiotic Candidatus Midichloria mitochondrii in ticks infesting camels (Camelus dromedarius) from Tunisia

Tick-borne bacteria are considered to be emerging in camels, but data about their occurrence in Tunisian dromedaries and their infesting ticks remain scarce. In this study, 412 camel blood samples and 327 partially engorged ticks were collected and tested for the presence of Coxiella burnetii and/or related strains, and Rickettsiales bacteria. Coxiella burnetii was detected in 9 Hyalomma impeltatum and 3 H. dromedarii with an overall prevalence rate of 3.6% (12/327). Candidatus Midichloria mitochondrii DNA was identified in 16 H. impeltatum and 10 H. dromedarii with an overall prevalence rate of 8% (26/327). Six ticks (2%) were found to be co-infected with these two bacteria. No positive DNA camel blood sample was observed for both bacteria. Genotyping and phylogenetic analysis of obtained C. burnetii partial sequences based on the IS1111 and htpB genes revealed 99-100% similarity to the pathogenic C. burnetii strains isolated from humans, ruminants and ticks, and that were genetically distant to those isolated from all endosymbiotic related strains (Coxiella-like bacteria). The analysis of the rickettsial partial sequences of the 16S rRNA gene showed 100% similarity to Ca. M. mitochondrii strains infecting Ixodid ticks and dogs. This is the first time that C. burnetii and Ca. M. mitochondrii have been detected in ticks from Tunisia, which raises the possibility of the involvement of Hyalomma tick species in the active diffusion of these bacteria among camels, other domestic animals and humans.

Estimation of acute and chronic Q fever incidence in children during a three-year outbreak in the Netherlands and a comparison with international literature

Background

In the Dutch 2007–2009 Q fever outbreak Coxiella burnetii was transmitted aerogenically from dairy goat farms to those living in the surrounding areas. Relatively few children were reported. The true number of pediatric infections is unknown. In this study, we estimate the expected number of acute and chronic childhood infections.

Methods

As Coxiella was transmitted aerogenic to those living near infected dairy goat farms, we could use adult seroprevalence data to estimate infection risk for inhabitants, children and adults alike. Using Statistics Netherlands data we estimated the number of children at (high) risk for developing chronic Q fever. Literature was reviewed for childhood (0–15 years) Q fever reports and disease rates. We compared this with Dutch reported and our estimated data for 2007–2009.

Results

In The Netherlands epidemic, 44 children were reported (1.2 % of total notifications). The childhood incidence was 0.15 compared to 2.6 per 10,000 inhabitants for adults. No complications were reported. Based on the expected similarity in childhood and adult exposure we assume that 9.8 % of children in the high-risk area had Q fever infection, resulting in 1562 acute infections during the Q fever epidemic interval. Based on the prevalence of congenital heart disease, at least 13 children are at high risk for developing chronic Q fever. In medical literature, 42 case reports described 140 childhood Q fever cases with a serious outcome (four deaths). In chronic Q fever, cardiac infections were predominant. Four outbreaks were reported involving children, describing 11 childhood cases. 36 National and/or regional studies reported seroprevalences varying between 0 and 70 %.

Conclusion

In the 3-year Dutch epidemic, few childhood cases were reported, with pulmonary symptoms leading, and none with a serious presentation. With an estimated 13 high-risk children for chronic infection in the high exposure area, and probably forty in the whole country, we may expect several chronic Q fever complications in the coming years in paediatric practice.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-015-1389-0) contains supplementary material, which is available to authorized users.

Infectious pathogens potentially transmitted by semen of the black variety of the Manchega sheep breed: Health constraints for conservation purposes

Conservation of genetic resources from endangered breeds may be conducted through germinal banks. Preservation of healthy samples is paramount to avoid preserving pathogens shed with germinal products. The black variety of Manchega sheep (BMS), and endangered breed endemic to south-central Spain, is the subject of a conservation program; a germinal bank has been recently established. However, several pathogens circulating in BMS flocks may be shed with semen and threaten BMS preservation. Therefore, we investigated the sanitary status of BMS flocks and semen samples from 4 of the 17 flocks in which this variety is bred worldwide. A serological screening for Maedi-Visna virus, bluetongue virus, Pestivirus spp., Brucella spp., Coxiella burnetii, Chlamydophila spp., Mycobacterium tuberculosis complex, Mycobacterium avium paratuberculosis, Anaplasma spp., Mycoplasma agalactiae, Toxoplasma gondii and Neospora caninum was performed to assess for pathogens potentially shed by semen. Semen samples from 11 of the 35 BMS rams and 4 samples from coexisting rams of the white variety (WMS) were analyzed by PCR to detect Maedi-Visna virus, C. burnetii, Anaplasma marginale, Anaplasma phagocytophilum and T. gondii. Maedi-Visna virus RNA was detected in 3 semen samples (2 BMS and 1 WMS) while C. burnetii DNA was detected in 3 samples from WMS rams. Pathogens that can be transmitted by semen were present in BMS flocks, and Maedi-Visna virus and C. burnetii showed the highest potential for transmission by artificial insemination. Our results point to the need of testing semen samples kept for conservation purposes of BMS before using them for artificial insemination.

Control of tick infestations and pathogen prevalence in cattle and sheep farms vaccinated with the recombinant Subolesin-Major Surface Protein 1a chimeric antigen

BACKGROUND

Despite the use of chemical acaricides, tick infestations continue to affect animal health and production worldwide. Tick vaccines have been proposed as a cost-effective and environmentally friendly alternative for tick control. Vaccination with the candidate tick protective antigen, Subolesin (SUB), has been shown experimentally to be effective in controlling vector infestations and pathogen infection. Furthermore, Escherichia coli membranes containing the chimeric antigen composed of SUB fused to Anaplasma marginale Major Surface Protein 1a (MSP1a) (SUB-MSP1a) were produced using a simple low-cost process and proved to be effective for the control of cattle tick, Rhipicephalus (Boophilus) microplus and R. annulatus infestations in pen trials. In this research, field trials were conducted to characterize the effect of vaccination with SUB-MSP1a on tick infestations and the prevalence of tick-borne pathogens in a randomized controlled prospective study.

METHODS

Two cattle and two sheep farms with similar geographical locations and production characteristics were randomly assigned to control and vaccinated groups. Ticks were collected, counted, weighed and classified and the prevalence of tick-borne pathogens at the DNA and serological levels were followed for one year prior to and 9 months after vaccination.

RESULTS

Both cattle and sheep developed antibodies against SUB in response to vaccination. The main effect of the vaccine in cattle was the 8-fold reduction in the percent of infested animals while vaccination in sheep reduced tick infestations by 63%. Female tick weight was 32-55% lower in ticks collected from both vaccinated cattle and sheep when compared to controls. The seroprevalence of Babesia bigemina was lower by 30% in vaccinated cattle, suggesting a possible role for the vaccine in decreasing the prevalence of this tick-borne pathogen. The effect of the vaccine in reducing the frequency of one A. marginale msp4 genotype probably reflected the reduction in the prevalence of a tick-transmitted strain as a result of the reduction in the percent of tick-infested cattle.

CONCLUSIONS

These data provide evidence of the dual effect of a SUB-based vaccine for controlling tick infestations and pathogen infection/transmission and provide additional support for the use of the SUB-MSP1a vaccine for tick control in cattle and sheep.

Comparison of Japanese Isolates ofCoxiella burnetiiby PCR-RFLP and Sequence Analysis

The genetic variation of Japanese isolates of Coxiella burnetii, the agent of Q fever, was found for the first time. Forty-nine out of 72 isolates had the chronic pattern of the isocitrate hydrogenase gene. Sequence analysis revealed that the isolates have a specific nucleotide sequence. The putative amino acid sequence was the same as that of chronic reference strains. These results suggest the variation of C. burnetii isolates in Japan.

In VitroSusceptibility to Tetracycline and Fluoroquinolones of Japanese Isolates ofCoxiella burnetii

Coxiella burnetii is the agent of the worldwide zoonosis, Q fever. The in vitro susceptibility to tetracycline and fluoroquinolones of Japanese isolates of C. burnetii was evaluated for the first time. The MICs against Japanese isolates were almost the same as the MICs against the foreign reference isolates. The results suggest that the common antibiotics therapy for Q fever used in other countries is also effective for Japanese Q fever patients.

Prevalence of tick-borne pathogens in Ixodes ricinus and Dermacentor reticulatus ticks from different geographical locations in Belarus

Worldwide, ticks are important vectors of human and animal pathogens. Besides Lyme Borreliosis, a variety of other bacterial and protozoal tick-borne infections are of medical interest in Europe. In this study, 553 questing and feeding Ixodes ricinus (n = 327) and Dermacentor reticulatus ticks (n = 226) were analysed by PCR for Borrelia, Rickettsia, Anaplasma, Coxiella, Francisella and Babesia species. Overall, the pathogen prevalence in ticks was 30.6% for I. ricinus and 45.6% for D. reticulatus. The majority of infections were caused by members of the spotted-fever group rickettsiae (24.4%), 9.4% of ticks were positive for Borrelia burgdorferi sensu lato, with Borrelia afzelii being the most frequently detected species (40.4%). Pathogens with low prevalence rates in ticks were Anaplasma phagocytophilum (2.2%), Coxiella burnetii (0.9%), Francisella tularensis subspecies (0.7%), Bartonella henselae (0.7%), Babesia microti (0.5%) and Babesia venatorum (0.4%). On a regional level, hotspots of pathogens were identified for A. phagocytophilum (12.5–17.2%), F. tularensis ssp. (5.5%) and C. burnetii (9.1%), suggesting established zoonotic cycles of these pathogens at least at these sites. Our survey revealed a high burden of tick-borne pathogens in questing and feeding I. ricinus and D. reticulatus ticks collected in different regions in Belarus, indicating a potential risk for humans and animals. Identified hotspots of infected ticks should be included in future surveillance studies, especially when F. tularensis ssp. and C. burnetii are involved.

Development and validation of two PCR tests for the detection of and differentiation between Anaplasma ovis and Anaplasma marginale

Anaplasma ovis and Anaplasma marginale are tick-transmitted bacteria that cause anaplasmosis in domestic and wild animals. Recent results show that some domestic and wild animals and ticks are susceptible to both A. ovis and A. marginale, thus supporting the need to differentiate between these species in hosts and ticks diagnosed with Anaplasma infection. However, although anaplasmosis is one of the most common diseases of grazing animals worldwide, rapid and effective tests are not available for the detection of and discrimination between these 2 Anaplasma species. The objective of this research was to develop an easy and reliable method to identify and discriminate between the closely related pathogens A. ovis and A. marginale. A. ovis and A. marginale major surface protein 4 (msp4) gene sequences were retrieved from different geographic strains and aligned to design 2 sets of primers in a region with significant differences between the 2 species, but completely conserved among strains. PCR reactions using these primers were 100% species-specific and detected all strains from each pathogen previously identified with other methods. The 2 sets of primers designed for the specific PCR amplification of A. ovis and A. marginale allow easy-to-detect and discriminate between the 2 pathogens, thus avoiding the time-consuming sequencing or multi-gene amplification procedures. This PCR provides a tool for the detection of A. ovis and A. marginale in ticks and in wildlife and domestic hosts.

Pathogen prevalence in ticks collected from the vegetation and livestock in Nigeria

Ticks are important disease vectors that can cause considerable economic losses by affecting animal health and productivity, especially in tropical and subtropical regions. In this study, we investigated the prevalence and diversity of bacterial and protozoan tick-borne pathogens in ticks collected from the vegetation and cattle in Nigeria by PCR. The infection rates of questing ticks were 3.1% for Rickettsia species, 0.1% for Coxiella burnetii and 0.4% for Borrelia species. Other pathogens, such as Babesia, Theileria, Anaplasma, and Ehrlichia species, were not detected in ticks from the vegetation. Feeding ticks collected from cattle displayed infection rates of 12.5% for Rickettsia species, 14% for Coxiella burnetii, 5.9% for Anaplasma species, 5.1% for Ehrlichia species, and 2.9% for Theileria mutans. Babesia and Borrelia species were not detected in ticks collected from cattle. Mixed infections were found only in feeding ticks and mainly Rickettsia species and Coxiella burnetii were involved. The diversity of tick-borne pathogens in Nigeria was higher in feeding than in questing ticks, suggesting that cattle serve as reservoirs for at least some of the pathogens studied, in particular C. burnetii. The total estimated herd infection rates of 20.6% for a Rickettsia africae-like species, 27% for Coxiella burnetii, and 8.5% for Anaplasma marginale/centrale suggest that these pathogens may have considerable implications for human and animal health.

Q Fever: current state of knowledge and perspectives of research of a neglected zoonosis

Q fever is an ubiquitous zoonosis caused by an resistant intracellular bacterium, Coxiella burnetii. In certain areas, Q fever can be a severe public health problem, and awareness of the disease must be promoted worldwide. Nevertheless, knowledge of Coxiella burnetii remains limited to this day. Its resistant (intracellular and environmental) and infectious properties have been poorly investigated. Further understanding of the interactions between the infected host and the bacteria is necessary. Domestic ruminants are considered as the main reservoir of bacteria. Infected animals shed highly infectious organisms in milk, feces, urine, vaginal mucus, and, very importantly, birth products. Inhalation is the main route of infection. Frequently asymptomatic in humans and animals, Q fever can cause acute or chronic infections. Financial consequences of infection can be dramatic at herd level. Vaccination with inactive whole-cell bacteria has been performed and proved effective in humans and animals. However, inactive whole-cell vaccines present several defects. Recombinant vaccines have been developed in experimental conditions and have great potential for the future. Q fever is a challenging disease for scientists as significant further investigations are necessary. Great research opportunities are available to reach a better understanding and thus a better prevention and control of the infection.

Detection of Coxiella burnetii in complex matrices by using multiplex quantitative PCR during a major Q fever outbreak in The Netherlands

Q fever, caused by Coxiella burnetii, is a zoonosis with a worldwide distribution. A large rural area in the southeast of the Netherlands was heavily affected by Q fever between 2007 and 2009. This initiated the development of a robust and internally controlled multiplex quantitative PCR (qPCR) assay for the detection of C. burnetii DNA in veterinary and environmental matrices on suspected Q fever-affected farms. The qPCR detects three C. burnetii targets (icd, com1, and IS1111) and one Bacillus thuringiensis internal control target (cry1b). Bacillus thuringiensis spores were added to samples to control both DNA extraction and PCR amplification. The performance of the qPCR assay was investigated and showed a high efficiency; a limit of detection of 13.0, 10.6, and 10.4 copies per reaction for the targets icd, com1, and IS1111, respectively; and no cross-reactivity with the nontarget organisms tested. Screening for C. burnetii DNA on 29 suspected Q fever-affected farms during the Q fever epidemic in 2008 showed that swabs from dust-accumulating surfaces contained higher levels of C. burnetii DNA than vaginal swabs from goats or sheep. PCR inhibition by coextracted substances was observed in some environmental samples, and 10- or 100-fold dilutions of samples were sufficient to obtain interpretable signals for both the C. burnetii targets and the internal control. The inclusion of an internal control target and three C. burnetii targets in one multiplex qPCR assay showed that complex veterinary and environmental matrices can be screened reliably for the presence of C. burnetii DNA during an outbreak.

Q fever in Japan: an update review

As neglected zoonosis for many years, Q fever is now ubiquitous in Japan. Similarly to elsewhere in the world, domestic animals are considered to be important reservoirs of the causal agent, Coxiella burnetii, a resistant intracellular bacterium. Infected animals shed bacteria in milk, feces, urine, vaginal mucous and birth products. Inhalation of bacteria present in the environment is the main route of animal and human infection. Shedding of C. burnetii in milk by domestic ruminants has a very limited impact as raw milk is seldom ingested by the Japanese population. The clinical expression of Q fever in Japan is similar to its clinical expression elsewhere. However clinical cases in children are more frequently reported in this country. Moreover, C. burnetii is specified as one of the causative organisms of atypical pneumonia in the Japanese Respiratory Society Guideline for the management of community-acquired pneumonia. In Japan, C. burnetii isolates are associated with acute illness and are mainly of moderate to low virulence. Cats are considered a significant source of C. burnetii responsible for human outbreaks in association with the presence of infected parturient cats. Since its recognition as a reportable disease in 1999, 7-46 clinical cases of Q fever have been reported by year. The epidemiology of Q fever in Japan remains to be elucidated and the exact modes of transmission are still unproven. Important further research is necessary to improve knowledge of the disease itself, the endogenous hosts and reservoirs, and the epidemiological cycle of coxiellosis in Japan.

Immunization with truncated recombinant protein SpaC of Erysipelothrix rhusiopathiae strain 715 serovar 18 confers protective immunity against challenge with various serovars

Previously, we showed that surface protective antigen (Spa) proteins of Erysipelothrix rhusiopathiae can be classified into three molecular species-SpaA, SpaB, and SpaC-and that SpaC is the most broadly cross-protective antigen among the three Spa proteins. In this study, we examined the ability of the α-helical domain, which comprises the N-terminal half of SpaC, to elicit cross-protective immunity in mice and pigs. Mice actively immunized with the full-length protein (rSpaC664) or the α-helical domain (rSpaC427), but not the C-terminal domain (rSpaC253), were protected against challenge with E. rhusiopathiae serovars 1a, 2, 6, 19, and 18 expressing heterologous (SpaA or SpaB) and homologous (SpaC) Spas. The α-helical domain seemed to provide better protection than rSpaC664, although the differences did not reach statistical significance. Similarly, mice passively immunized with rabbit anti-rSpaC664 or anti-rSpaC427 sera, but not anti-rSpaC253 serum, were protected from challenge with various serovars. Pigs immunized with SpaC427 also developed specific antibodies against Spa proteins and were protected from challenge with the highly virulent heterologous E. rhusiopathiae strain Fujisawa (serovar 1a). Taken together, these results demonstrate for the first time the striking protective efficacy of the α-helical domain-mediated immunization in both mice and pigs, thereby highlighting its utility as the most promising candidate for the development of a safe and effective vaccine against erysipelas.

Prevalence and seasonality of tick-borne pathogens in questing Ixodes ricinus ticks from Luxembourg

In Europe, ixodid ticks are important arthropod vectors of human and animal pathogens, but comprehensive studies of the prevalence of all relevant pathogens in Central Europe are scarce. As a result of ecological changes, the incidences of tick-borne infections are expected to increase. In this study, 1,394 nymphal and adult Ixodes ricinus ticks sampled monthly during the active season from 33 ecologically distinct collection sites throughout Luxembourg were screened for all human tick-borne pathogens relevant in Central Europe. Species were identified by sequence analysis of detection PCR amplicons. Mean infection rates of ticks were 11.3% for Borrelia burgdorferi sensu lato, 5.1% for Rickettsia sp., 2.7% for Babesia sp., and 1.9% for Anaplasma phagocytophilum. No tick was found to be infected with Coxiella sp., Francisella tularensis subsp., or Tick-borne encephalitis virus (TBEV). A total of 3.2% of ticks were infected with more than one pathogen species, including mixed Borrelia infections (1.5%). Seasonal variations of tick infection rates were observed for Borrelia, Babesia, and Anaplasma, possibly reflecting a behavioral adaptation strategy of questing ticks. A positive correlation between the grade of urbanization and Borrelia infection rate of ticks was observed, suggesting an established urban zoonotic cycle. We also found Hepatozoon canis (0.1%) and Bartonella henselae (0.3%), which so far have not been found in questing Ixodes ricinus ticks in Central Europe.

Prevalence of Coxiella burnetti infection in wild and farmed ungulates

The aim of this study was to evaluate by serology and PCR analyses the prevalence of Coxiella burnetti infection in ungulates in Spain. Sera were collected from red deer (Cervus elaphus; n=116), roe deer (Capreolus capreolus; n=39), fallow deer (Dama dama; n=13) and cattle (n=79). Sera were tested for anti-C. burnetii antibody detection by means of an immunofluorescence antibody assay (IFA) and C. burnetii DNA was amplified by PCR in samples from ungulates that had antibodies to phase II antigens. Twenty-nine, 15 and 39 percent of the red deer, roe deer and cattle had antibodies against C. burnetii, respectively. None of the fallow deer sera tested positive. Seroprevalence was statistically higher in farmed than in wild red deer and higher in northern than in southern populations, whereas an inverse pattern was observed for the roe deer. Most of the seropositive animals had only anti-C. burnetii phase II antibodies, thus showing the acute nature of infections in the sampled ungulates. These results show that C. burnetii circulates in wild ungulates in Spain and suggest that they can act as pathogen reservoirs for both domestic animals and humans.

Genetic and antigenic diversity of the surface protective antigen proteins of Erysipelothrix rhusiopathiae

The surface protective antigen (Spa) protein of Erysipelothrix rhusiopathiae has been shown to be highly immunogenic and is a potential candidate for a new vaccine against erysipelas. In this study, we cloned and sequenced spa genes from all E. rhusiopathiae serovar reference strains as well as from a serovar 18 strain which was not classified as any species in the genus Erysipelothrix. Sequence analysis revealed that the Spa proteins could be classified into three molecular species, including SpaA, which was previously found in serovars 1a and 2, and the newly designated SpaB and SpaC proteins. The SpaA protein is produced by E. rhusiopathiae serovars 1a, 1b, 2, 5, 8, 9, 12, 15, 16, 17, and N, the SpaB protein is produced by E. rhusiopathiae serovars 4, 6, 11, 19, and 21, and the SpaC protein is produced only by serovar 18. The amino acid sequence similarity was high among members of each Spa type (96 to 99%) but low between different Spa types ( approximately 60%). The greatest diversity in Spa proteins was found in the N-terminal half of the molecule (50 to 57% similarity), which was shown to be involved in immunoprotection. Coinciding with this, immunoblot analysis revealed that rabbit antisera specific to each Spa reacted strongly with the homologous Spa protein but weakly with heterologous Spa proteins. A mouse cross-protection study showed that the three recombinant Spa (rSpa) proteins elicited complete protection against challenge with homologous strains but that the level of protection against challenge with heterologous strains varied depending on the rSpa protein used for immunization. Our study is the first to demonstrate sequence and antigenic diversity in Spa proteins and to indicate that rSpaC may be the most promising antigen for use as a vaccine component because of its broad cross-protectiveness.

Clinical manifestations of Q fever in adults and children

Q fever is a common zoonosis with almost a worldwide distribution caused by Coxiella burnetii. Farm animals and pets are the main reservoirs of infection and transmission to humans is usually via inhalation of contaminated aerosols, which may be carried by the wind far from the original source of infection. Occupational groups with close association with farm or wild animals are most at risk, however travellers occasionally become infected. The disease is associated with a wide spectrum of clinical manifestations and symptoms, ranging from asymptomatic infection to fatal disease. Awareness of the disease and newer diagnostic methods led to increase of recognition and detection in cases with various or multiple symptoms in adults and children. However, children seem to be less frequently symptomatic and may have milder disease. This review of Q fever cases examines clinical manifestations and symptoms of Q fever in both adults and children and shows that certain symptoms and their severity have altered presentation in children with acute and chronic Q fever when compared to adults.

Observed Prevalence of Tick-borne Pathogens in Domestic Animals in Sicily, Italy during 2003?2005

The objective of this study was to characterize the observed prevalence of tick-borne pathogens (TBP) in domestic animals in Sicily, Italy during 2003-2005. Serological (competitive ELISA and indirect immunofluorescence antibody, n = 3299) and DNA tests (polymerase chain reaction and reverse line blot, n = 2565) were conducted on horse, donkey, cattle, sheep, goat, pig and dog samples. Pathogens analysed included Anaplasma, Ehrlichia, Rickettsia, Babesia and Theileria species, and Coxiella burnetii. The most prevalent TBP were Anaplasma and Babesia species. The results reported herein suggested that cattle could serve as the major reservoir for Babesia and Theileria spp. while for Anaplasma spp. cattle, dogs, sheep and goats may be the most important reservoir species. These results expanded our knowledge about the prevalence of TBP in Sicily and provided information to understand the epidemiology of tick-borne diseases and may help to implement measures to diagnose, treat and control transmission to humans and animals in this region.

Coxiella burnetii Infection

Coxiella burnetii is an obligate intracellular bacterium that causes a worldwide zoonosis, Q fever, and can be misused as a biological warfare agent. Infection in animals (coxiellosis) is mostly persistent. Infection in humans is often asymptomatic, but it can manifest as an acute disease (usually a self-limited flu-like illness, pneumonia, or hepatitis) or as a chronic form (mainly endocarditis, but also hepatitis and chronic fatigue syndrome). C. burnetii infection in pregnant women may result in abortions, premature deliveries, and stillbirths. Infection in nature is maintained and transmitted by ticks as the principal vector and reservoir. Cattle, sheep, and goats are the most important source of human infections. Humans contract C. burnetii infection mostly by aerosol in contact with contaminated environs, wind playing an important factor in spreading the infection. The wide distribution of C. burnetii contributes to a high resistance of its extracellular small cell variant to environmental conditions. Its intracellular large cell variant, adapted to survive under harsh conditions of phagolysosomes, enables long-term survival and persistence of C. burnetii, namely in monocytes/macrophages. Host factors such as underlying disease and cell-mediated immunity play a decisive role in the clinical expression of C. burnetii infection. Complete genome analysis of C. burnetii will certainly contribute to better understanding of the pathogenesis of C. burnetii infection and will improve Q fever diagnosis and immunoprophylaxis.

Treatment of chronic fatigue syndrome with antibiotics: pilot study assessing the involvement of Coxiella burnetii infection

OBJECTIVE

To examine whether Coxiella burnetii (C. burnetii) is involved in chronic fatigue syndrome (CFS), we administered tetracycline antibiotics to subjects with CFS, and followed changes in clinical symptoms, PCR findings, and C. burnetii antibody titers.

PATIENTS AND METHODS

The subjects were 8 patients with CFS and 213 with nonspecific complaints such as chronic fatigue and low-grade fever for several months or longer but not meeting the diagnostic criteria for CFS. All were examined for C. burnetii infection by nested PCR and the indirect immunofluorescence test (IF).

RESULTS

Four CFS patients (the CFS group) and 54 controls [the post-Q fever fatigue syndrome (QFS) group] positive for C. burnetii were treated mainly with minocycline or doxycycline (100 mg/day) for 3 months. After treatment, all 58 patients tested negative for C. burnetii infection. In the CFS group, no significant difference was noted between the mean pre- and post-treatment temperatures or headache scores. Similarly, there was no significant improvement in performance status (PS) scores. In the QFS group, however, mean temperatures and headache scores were significantly decreased after treatment (p<0.001). PS scores were also improved.

CONCLUSION

These results suggest the possibility of direct involvement of C. burnetii in the pathological state of CFS to be low, despite the C. burnetii infection rate being high in CFS patients. This is a pilot study and further larger investigations are necessary to confirm our preliminary results.

Infection with Anaplasma phagocytophilum in a seronegative patient in Sicily, Italy: case report

BACKGROUND

Anaplasma phagocytophilum causes human granulocytic anaplasmosis (HGA) in humans, which has been recognized as an emerging tick-borne disease in the United States and Europe. Although about 65 cases of HGA have been reported in Europe, some of them do not fulfill the criteria for confirmed HGA. Confirmation of HGA requires A. phagocytophilum isolation from blood, and/or identification of morulae in granulocytes and/or positive PCR results with subsequent sequencing of the amplicons to demonstrate specific rickettsial DNA. Seroconversion or at least fourfold increase in antibody titers to A. phagocytophilum has been used as criteria for confirmed HGA also.

CASE PRESENTATION

Infection with A. phagocytophilum was confirmed by PCR in a patient in Sicily, Italy, who had negative serology for A. phagocytophilum. A fragment of A. phagocytophilum 16S rDNA was amplified by two independent laboratories and sequenced from two separate patient's blood samples. The 16S rDNA sequence was identical in both samples and identical to the sequence of the A. phagocytophilum strain USG3 originally obtained from a dog.

CONCLUSION

Infection with A. phagocytophilum was confirmed in a patient without a detectable antibody response against the pathogen. The results reported herein documented the first case of confirmed HGA in Sicily, Italy. These results suggested the possibility of human infections with A. phagocytophilum strains that result in clinical symptoms and laboratory findings confirmatory of HGA but without detectable antibodies against the pathogen.

Prevalence of community-acquired respiratory tract infections associated with Q fever in Japan

A multicenter prospective cohort study to assess the occurrence and characteristics of acute Q fever associated with community acquired respiratory infections was performed. Among the 400 patients enrolled for the study, 10 (2.50%) patients (5 out of 120 cases of pneumonia, 3 out of 131 cases of acute bronchitis, and 2 out of 149 cases of upper respiratory infections) were diagnosed as having acute Q fever. Contact with dogs or cats before the onset of the disease was confirmed in most of the patients. The clinical profiles of these 10 patients were generally similar to those reported from other countries, such as fever, general fatigue and liver dysfunction, except for the predominance of sporadic cases among the urban population. Our study demonstrates that Q fever is not uncommon cause of community-acquired respiratory infections even in Japan.

Improvement of chronic nonspecific symptoms by long-term minocycline treatment in Japanese patients with Coxiella burnetii infection considered to have post-Q fever fatigue syndrome

OBJECTIVE

To address the presence of post-Q fever fatigue syndrome (post-QFS) in Japan, and to evaluate the efficacy of minocycline for this condition.

PATIENTS AND METHODS

In 20 Coxiella burnetii (C. burnetii) seropositive patients with persistent nonspecific symptoms including general fatigue, low-grade fever, myalgia and arthralgia, changes in subjective symptoms, C. burnetii antibody titers and C. burnetii DNA were evaluated after antibiotic treatment.

RESULTS

After treatment mainly with minocycline (100 mg/day for 3 months), the clinical picture improved in all 20 patients as evidenced by decreases in body temperature (13/17), general fatigue (20/20) and headache (9/12). The mean performance status (PS) score improved from 5.0 to 1.8 (p<0.01). All 7 who had been positive for C. burnetii DNA, became negative together with an improvement in subjective symptoms. Indirect immunofluorescence tests demonstrated 6 of the 20 patients to be positive for C. burnetii IgM antibody to phase II antigen (1:32), and 18 to be positive for IgG antibody (1:128, 1:256). Antibody titers of both IgM (6/6, 1:16) and IgG (18/18, 1:16) decreased markedly after treatment.

CONCLUSION

These results of an open label study in Japan suggest that minocycline administration is useful for improving chronic nonspecific symptoms considered to be post-Q fever fatigue syndrome caused by C. burnetii infection.

Q fever in children

Q fever is a zoonosis caused by Coxiella burnetii. Farm animals and pets are the main reservoirs of infection, and transmission to human beings is mainly accomplished through inhalation of contaminated aerosols. This illness is associated with a wide clinical spectrum, from asymptomatic or mildly symptomatic seroconversion to fatal disease. Q fever in children has been rarely reported. We reviewed published work on this topic. Seroepidemiological studies show that children are frequently exposed to C burnetii. However, children are less frequently symptomatic than adults following infection, and may have milder diseases. Using the standard diagnostic criteria, we identified 46 published paediatric cases only. Self-limited febrile illness and pneumonia were the most common manifestations of acute Q fever. Chronic disease manifested as endocarditis and osteomyelitis. A history of exposure to possible sources of infection with C burnetii in a child with a compatible infectious syndrome should prompt testing for Q fever. Studies are required to determine the spectrum of morbidity associated with Q fever during childhood.

Acute cerebellitis

Many recent reports of acute cerebellitis with a critical or potentially critical course have changed the conception of the disease from an acute cerebellar ataxia with a benign course to a notable disease entity with a heterogeneous pathogenesis. The most characteristic finding by magnetic resonance imaging is diffuse cortical swelling of the cerebellum, often complicated by hydrocephalus or tonsillar herniation. A timely assessment and appropriate choice of treatment, including surgical intervention when indicated, are key to improving the outcome of affected patients.

Detection of serum antibodies to Bartonella henselae and Coxiella burnetii from Japanese children and pregnant women

The participation of Bartonella henselae and Coxiella burnetii in the pathogenesis of fever of unknown origin (FUO) and lymphadenopathy has not been completely clarified. Prevalence of these two agents in Japanese children is also unknown. Serum IgG and IgM antibodies to B. henselae and to C. burnetii were examined by the indirect fluorescence antibody assay. Enzyme immunoassay kits were used to detect serum IgG and IgA antibodies against Chlamydia trachomatis. Out of 200 healthy normal pregnant women, two (1.0%) had serum IgG antibodies to B. henselae, four (2.0%) to C. burnetii and 49 (24.5%) to C. trachomatis. Out of 29 patients with FUO, one (3.4%) had serum IgG antibodies to B. henselae, four (13.8%) to C. burnetii and none to C. trachomatis. Out of 31 patients with cervical lymphadenopathy, three (9.6%) had serum IgG antibodies to B. henselae, two (6.5%) to C. burnetii and none to C. trachomatis. Out of 22 patients with generalized lymphadenopathy, one (4.5%) had serum IgG antibodies to B. henselae, three (13.6%) to C. burnetii and none to C. trachomatis. Prevalences of serum antibodies to C. burnetii in the patients with FUO and generalized lymphadenopathy and to B. henselae in the patients with cervical lymphadenopathy were significantly higher than those of normal pregnant women (Welch's t-test; P<0.01). These two agents may have some roles in the pathogenesis of FUO and lymphadenopathy in Japanese children.

Q fever

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.

Acute cerebellitis caused by Coxiella burnetii

We report a childhood case of severe acute cerebellitis caused by Coxiella burnetii. After 10 days of fever and headache, the patient fell into a drowsy state. Examination of the cerebrospinal fluid (CSF) revealed pleocytosis, an increased level of protein, and negative results in bacterial and viral studies. Magnetic resonance imaging demonstrated a herniated tonsil compressed by the swollen vermis. Administration of minocycline relieved the patient's clinical symptoms. C. burnetii was isolated from the CSF obtained during convalescence.

Evaluation of a recombinant 27-kDa outer membrane protein of Coxiella burnetii as an immunodiagnostic reagent

The 27-kDa outer membrane protein from eight strains of Coxiella burnetii was expressed in the pET-21c protein expression system. Two fusion proteins with molecular masses of 30 and 32 kDa were evident in all eight of the recombinants by SDS-PAGE and immunoblotting. A protein having an approximate size of 30 kDa was purified from the Escherichia coli lysates by one-step affinity purification. The utility of the purified recombinant protein in ELISA was also evaluated by testing its reactivity with human sera and comparing this reactivity with that of Nine Mile phase II antigen. All of the 40 IF-positive serum samples were ELISA-positive for both the Nine Mile phase II and recombinant antigens, and negative serum controls were negative for both antigens. These results suggest that ELISA with the 27-kDa recombinant antigen is a sensitive and specific method for detecting anti-C. burnetii antibodies in human sera.

Direct identification of Coxiella burnetii plasmids in human sera by nested PCR

Nested PCR assays were used for the direct identification of Coxiella burnetii plasmids in human sera. A total of 81 serum samples from 81 patients with Q fever were tested by nested PCR with four sets of primers. The first set of primers was used to detect the genomic sequences. The second set of primers was used to detect the conserved sequences of the plasmids. Another two sets of primers were used to identify the QpH1 and QpRS plasmids. QpH1 and QpRS plasmid-specific sequences were identified in 40 (49.4%) and 24 (29.6%) of the serum samples, respectively. Both of the QpH1 and QpRS plasmid-specific sequences were detected in 5 (8.6%) of the serum samples but were not found in 12 (20.7%) of the serum samples. Furthermore, all of the 23 acute-phase serum samples were positive for the QpH1 plasmid and negative for the QpRS plasmid. Nested PCR with plasmid-specific primers appears to be a useful method for the direct typing of C. burnetii plasmids in human sera.

Prevalence of Coxiella burnetii infection in dairy cattle with reproductive disorders

The prevalence of Coxiella burnetii infection in 207 cattle with reproductive disorders was studied by using an indirect immunofluorescence (IF) test, nested polymerase chain reaction (PCR) and isolation. IF antibodies to phase I and phase II antigens of C. burnetii were found in 122 (58.9%) and 125 (60.4%) of the sera, respectively, and PCR-positives were found in 8 (3.9%) of the sera and in 51 (24.6%) of the milk samples. In addition, C. burnetii was isolated from 51 (24.6%) of the milk samples by inoculating laboratory mice. The results indicate that the IF test plus PCR are useful in the diagnosis of bovine coxiellosis. It is difficult to deny that dairy cattle with reproductive disorders would be one of the important reservoirs of C. burnetii responsible for infection in both animal and human populations in Japan.

Advances in the understanding of Coxiella burnetii infection in Japan

Q fever is a zoonotic disease caused by a rickettsia Coxiella burnetii. Since its first description in 1937, the disease has been found to be present in most countries of the world. Serological evidences of Q fever in humans and coxiellosis in animals were reported in Japan in the 1950s, however, systematic studies of the disease did not begin until the report of isolation of C. burnetii from an acute Q fever patient in 1989. In addition to the extensive information about epidemiology of the disease, the understanding of Japanese isolates of C. burnetii is increasing rapidly in recent years. In this review, the epidemiology of the disease along with some characteristics of isolates of C. burnetii in Japan is summarized in five sections, i.e., coxiellosis, Q fever, modes of spread of the infection, laboratory diagnosis of the infection and some characteristics of Japanese isolates. This review includes some recent, unpublished data from our and other groups.

Detection of Coxiella burnetii specific DNA in blood samples from Japanese patients with chronic nonspecific symptoms by nested polymerase chain reaction

The nested polymerase chain reaction (PCR) was used for direct species-specific detection of Coxiella burnetii in blood samples from 52 patients with chronic nonspecific symptoms, but no diagnostic or treatment history of Q fever. All patients had been in ill-health with general fatigue, muscle and joint pain, headache, etc., for one to more than 10 years. Seventeen (33%) showed evidence of C. burnetii infection, based on amplification of 438-bp fragments specific to C. burnetii by nested PCR, and 94% of positive patients reported close contact with animals. In contrast, five (9.6%) of 52 samples from healthy adult controls and two (2.8%) of 70 cord blood samples were positive by nested PCR. These data suggest a high prevalence of infection among adult patients with long term, nonspecific complaints who live in close contact with animals and the possible existence of a chronic post-acute Q fever syndrome in Japan.

Antigenic characteristics of polypeptides of Coxiella burnetii isolates

Eighteen Coxiella burnetii strains from a variety of clinical and geographical sources were screened for antigenic variation of polypeptides by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) coupled with Coomassie brilliant blue (CBB) staining or immunoblotting. These polypeptide profiles showed the greatest variability in the region from 33 to 8.1 kDa. Such differences in the antigenicity of the polypeptides were also recognized by immunoblotting with 15 various mouse anti-C. burnetii antisera. In addition, we detected a polypeptide at about 28 kDa which was immunodominant in strains from human cases of acute Q fever, milk and ticks but not immunogenic in strains from human cases of chronic Q fever. These findings suggest that this polypeptide is a marker to distinguish between acute and chronic strains.