Explore the vast range of titles available.

Q fever is a highly infectious disease with a worldwide distribution. Its causative agent, the intracellular bacterium Coxiella burnetii, infects a variety of vertebrate species, including humans. Its evolutionary origin remains almost entirely unknown and uncertainty persists regarding the identity and lifestyle of its ancestors. A few tick species were recently found to harbor maternally-inherited Coxiella-like organisms engaged in symbiotic interactions, but their relationships to the Q fever pathogen remain unclear. Here, we extensively sampled ticks, identifying new and atypical Coxiella strains from 40 of 58 examined species, and used this data to infer the evolutionary processes leading to the emergence of C. burnetii. Phylogenetic analyses of multi-locus typing and whole-genome sequencing data revealed that Coxiella-like organisms represent an ancient and monophyletic group allied to ticks. Remarkably, all known C. burnetii strains originate within this group and are the descendants of a Coxiella-like progenitor hosted by ticks. Using both colony-reared and field-collected gravid females, we further establish the presence of highly efficient maternal transmission of these Coxiella-like organisms in four examined tick species, a pattern coherent with an endosymbiotic lifestyle. Our laboratory culture assays also showed that these Coxiella-like organisms were not amenable to culture in the vertebrate cell environment, suggesting different metabolic requirements compared to C. burnetii. Altogether, this corpus of data demonstrates that C. burnetii recently evolved from an inherited symbiont of ticks which succeeded in infecting vertebrate cells, likely by the acquisition of novel virulence factors.

Eight hard tick species were identified among a total of 466 samples collected from vegetation in southern Thailand: Dermacentor compactus ( n  = 150), D. steini ( n  = 100), D. auratus ( n  = 85), D. tricuspis ( n  = 41), Haemaphysalis hystricis ( n  = 69), H. semermis ( n  = 3), H. shimoga ( n  = 2) and Amblyomma testudinarium ( n  = 16). In 93 ticks from these 8 species, Coxiella bacteria were detected via 16 S rRNA, groEL (60-kDa chaperone heat shock protein B) and rpoB (β subunit of bacterial RNA polymerase) genes. Interestingly, Coxiella burnetii was detected for the first time in H. hystricis and D. steini in Songkhla Province. Coxiella -like endosymbionts (CLEs) were also found in 84 ticks from 7 species, namely, D. compactus , D. auratus , D. tricuspis , H. hystricis , H. semermis , H. shimoga and A. testudinarium . Among these, CLEs associated with D. compactus and H. semermis were reported for the first time in Thailand. Phylogenetic analysis and generation of a haplotype network clearly revealed 2 distinct groups of Coxiella bacteria, namely, C. burnetii and CLEs. The nucleotide alignment of Coxiella 16 S rRNA revealed differences in bases at 3 positions between C. burnetii and CLEs. Thus, these differences could be used as liable molecular markers for discriminating these 2 groups in hard ticks.

Coxiellosis is a zoonotic bacterial disease caused by Coxiella burnetii ( C. burnetii ) infection that occurs as subclinical and clinical infections in animals and humans worldwide except in the Antarctica and New Zealand. The objectives of this study were to estimate the seroprevalences of C. burnetti infections in slaughtered camels and abattoir workers as well as to detect C. burnetii DNA in the clotted blood in the same study subjects at Al Bawadi abattoir of Al Ain city, in the United Arab Emirates, UAE. A cross-sectional study design was used to test 393 slaughtered camels and 86 abattoir workers for C. burnetii antibodies between March 2022 and July 2023 using enzyme-linked immunosorbent assay (ELISA) kits supplied by ID Vet multispecies and Abbexa, respectively. Besides, real-time polymerase chain reaction (qPCR) was used for the detection of C. burnetti DNA in clotted blood of 366 camels and 86 abattoir workers. The seroprevalences of C. burnetii infection were 52.9% (95% confidence interval, CI: 46.0, 60.6%) and 24.4% (95% CI: 15.1, 37.3%) in camels and abattoir workers. But, C. burnetii DNA was not detected in clotted blood samples of camels and abattoir workers. Sex, age and body condition of the camels were not associated with the seroprevalence of C. burnetii while abattoir workers of African origin were more likely to be seropositive (odds ratio, OR = 3.70; 95% CI: 1.05, 13.60) than abattoir workers of south Asian origin. The seroprevalences of C. burnetii infections were high in both slaughtered camels and abattoir workers although its DNA was not detected in the clotted blood of either of the study subjects.

Abstract Q fever is a zoonotic disease caused by the bacterium Coxiella burnetii with domestic ruminants considered the main infection source for humans. Coxiella burnetii infection in Australian native wildlife (ANW) species has been demonstrated, however their role as reservoirs remains unclear. This study aimed to determine the prevalence of C. burnetii DNA in tissues, swabs, and secretions from ANW, (primarily marsupials from eastern Australia), and further understand the pathogenesis in these species by identifying tissues infected and potential shedding routes. The study utilized an optimized multiplex quantitative PCR assay targeting three C. burnetii genes and a stringent classification system that prioritized specificity to overcome false positives known to occur due to Coxiella-like endosymbiont species. Of the 141 animals examined, one eastern gray kangaroo cloacal swab tested positive for C. burnetii DNA (at ~11 genome equivalents per reaction) in all three genes. Four animals were classified as suspect with amplification in two genes at a lower copy number. Genotyping of the definitively positive animal returned a C. burnetii genotype previously associated with human Q fever cases, which underscores the importance of Q fever vaccination where available for individuals in contact with wildlife, given the potential severity of the disease in humans. A stringent molecular methodology prioritizing specificity was used to investigate Coxiella burnetii pathogenesis in Australian macropods and wombats and a genotype previously causing Q fever in humans was identified.

Q fever is an important zoonosis, yet it is often neglected and can present large outbreaks, as observed in the Netherlands. In the past few years, cases of Q fever have been described in Brazil; however, the epidemiological situation of Q fever in ruminants, the main reservoir of the pathogen, is unknown in this country. Our study aimed to estimate the prevalence of C. burnetii in cattle sent to slaughterhouses using an immunofluorescence assay (IFA) and quantitative real-time PCR (qPCR). From 1515 cattle serum samples collected from nine slaughterhouses, 23.8% (360/1515) were serologically positive by IFA (cutoff titer>1:64), indicating past or recent exposure to C. burnetii infection. Among the 54 cities sampled during the study, 83.3% (45/54) had at least one seropositive animal. Subsequently, all seropositive samples were submitted to qPCR for C. burnetii DNA, and 12.2% (44/360) of the sera were qPCR positive, which indicates bacteremia and suggests active or recent infection. The results highlight the risk for abattoir workers that results from exposure to contaminated aerosols produced during slaughter procedures. Moreover, the heat maps that were construction from the positive samples demonstrate the widespread distribution of C. burnetii in the State of São Paulo, Brazil and denotes the need for surveillance and preventive measures to reduce the prevalence in cattle.

Coxiella burnetii is an intracellular bacterial pathogen that causes Q fever. Infected pregnant goats are a major source of human infection. However, the tissue dissemination and excretion pathway of the pathogen in goats are still poorly understood. To better understand Q fever pathogenesis, we inoculated groups of pregnant goats via the intranasal route with a recent Dutch outbreak C. burnetii isolate. Tissue dissemination and excretion of the pathogen were followed for up to 95 days after parturition. Goats were successfully infected via the intranasal route. PCR and immunohistochemistry showed strong tropism of C. burnetii towards the placenta at two to four weeks after inoculation. Bacterial replication seemed to occur predominantly in the trophoblasts of the placenta and not in other organs of goats and kids. The amount of C. burnetii DNA in the organs of goats and kids increased towards parturition. After parturition it decreased to undetectable levels: after 81 days post-parturition in goats and after 28 days post-parturition in kids. Infected goats gave birth to live or dead kids. High numbers of C. burnetii were excreted during abortion, but also during parturition of liveborn kids. C. burnetii was not detected in faeces or vaginal mucus before parturition. Our results are the first to demonstrate that pregnant goats can be infected via the intranasal route. C. burnetii has a strong tropism for the trophoblasts of the placenta and is not excreted before parturition; pathogen excretion occurs during birth of dead as well as healthy animals. Besides abortions, normal deliveries in C. burnetii-infected goats should be considered as a major zoonotic risk for Q fever in humans.

Coxiella burnetii is the causative agent of Q fever which is a highly infectious zoonotic disease. C. burnetii has become one of the most important causes of abortion in livestock, which can lead to widespread abortions in these animals. There are very limited studies on the prevalence of C. burnetii infection in cases of animal abortion in Iran. The aim of this study was to investigate the occurrence of C. burnetii in ruminant abortion samples in Iran. Abortion samples from cattle, sheep and goats were collected from different parts of Iran and were tested using Real-time PCR targeting the IS1111 element of C. burnetii. In this study, 36 samples (24.7%) of the 146 collected samples were positive for C. burnetii. The prevalence of C. burnetii was 21.3% (20 of 94 samples) in sheep samples. Also, 10 of 46 cattle samples (21.7%) were positive. All six goat abortion samples were positive for C. burnetii. The findings of the study demonstrate that C. burnetii plays an important role in domestic ruminant abortions in Iran, suggesting that more attention should be paid to the role of C. burnetii in domestic animal abortions by veterinary organizations. The risk of transmitting the infection to humans due to abortion of animals should also be considered.

The microbiome and the prevalence of the pathogenic bacterium Coxiella burnetii in ticks associated with white rhinoceros, Ceratotherium simum , is unknown. Targeted Illumina 16S rRNA amplicon sequencing was used to characterize the bacterial microbiome diversity found within 40 Amblyomma hebraeum and 40 Dermacentor rhinocerinus ticks collected from 40 white rhinoceros individuals in the Kruger National Park, South Africa. Specific emphasis was also given to further investigate the prevalence of the pathogenic C. burnetti in these tick species. At the phylum level, Proteobacteria dominated both tick microbiomes, followed by Actinobacteria and Firmicutes; Coxiella was the most abundant genus within A. hebraeum and Rickettsia within D. rhinocerinus . While alpha diversity did not differ significantly between the two tick species, beta diversity revealed significant species-specific differences in bacterial community composition. Additionally, there was no correlation between sampling region and microbiome diversity or composition for either tick species. Twenty-five Coxiella amplicon sequence variants (ASVs) were identified, forming three distinct monophyletic Coxiella clades and a fourth single ASV lineage. The Coxiella clades showed a correlation to tick species identity with D. rhinocerinus harboring significantly greater Coxiella diversity than A. hebraeum— potentially indicative of different coevolutionary pathways between the bacteria and their respective hosts. PCR of the IS1111 transposase gene for 238 ticks detected a 66.1% (56.7–74.4%) prevalence for C. burnetii in D. rhinocerinus compared to 55.8% in A. hebraeum (46.5–64.8%). These findings support a notion that each tick species is characterized by its own microbiome community composition and that both A. hebraeum and D. rhinocerinus may act as reservoirs and potential vectors of C. burnetii to white rhinoceros.

Tick-borne bacteria of the genera Rickettsia and Coxiella cause several emerging veterinary and human infectious diseases. Ticks of the genus Hyalomma are medically important vectors due to their potential role in the transmission of pathogens to vertebrate hosts. There is an inadequate knowledge on tick-borne Rickettsia spp. and Coxiella spp. in ticks infesting transhumant camels in Pakistan. In this study, we conducted a molecular survey for screening of Rickettsia spp. and Coxiella spp. in ticks infesting camels. Seven hard tick species including Hyalomma dromedarii, Hyalomma anatolicum, Hyalomma scupense, Hyalomma isaaci, Hyalomma turanicum, Hyalomma asiaticum, and Rhipicephalus sanguineus s.l were confirmed on camels in three distinct physiographic regions of Khyber Pakhtunkhwa, Pakistan. A subset of morphologically identified ticks were subjected to molecular assays for the genetic characterization of ticks and the detection and genetic characterization of Rickettsia and Coxiella species using standard genetic markers. Ticks screened for pathogens resulted in the detection of Rickettsia aeschlimannii and Candidatus Rickettsia shennongii and Coxiella burnetii. The molecular analysis further reveals the presences of an undetermined Rickettsia aeschlimannii-like species, that is making a distinct phylogenetic clade with R. aeschlimannii. The detection of pathogens in camel ticks poses potential health hazards as these ticks frequently bites humans. Molecular screening of Rickettsia spp. and Coxiella spp. associated with camel ticks is a preliminary step toward the surveillance of evaluating their zoonotic threats in the region.

Coxiella burnetii , the causative agent of Q fever, is an emerging pathogen that has the potential to cause severe chronic infections in animals and humans worldwide. The detrimental impact on public health is projected to be higher in the low- and middle-income countries given their lower capacity to sustain effective surveillance and response measures. We implemented a national serosurvey of cattle in Kenya to map the spatial distribution of the pathogen. The study used serum samples that were collected from randomly selected cattle in different ago-ecological zones across the country. These samples were screened for the pathogen using PrioCHECK Ruminant Q Fever AB Plate ELISA kit. The laboratory findings were analyzed using INLA package to identify risk factors for C. burnetii exposure from herd- and animal-level factors, area, and bioclimatic datasets accessed from online databases. A total of 6,593 cattle were recruited for the study; of these, 7.9% (95% CI; 7.2–8.5) were seropositive. Outputs from the multivariable analysis revealed that the animal age and some of the geographical variables including wind speed, area under shrubs and “petric calcisols” type of soil were significantly associated with C. burnetii seropositivity. Being a calf, weaner or subadult was associated with lower odds of exposure compared to being an adult by 0.24 (credibility interval: 2.5% and 97.5%), 0.41 (0.30–0.55) and 0.51 (0.38–0.69), respectively. In addition, a unit increase in the wind speed increased the odds of C. burnetii seropositivity by 1.27 (1.05–1.52) while an increase on the land area under shrubs was associated with lower odds of exposure (0.67 [0.47–0.69]). The effect of petric calcisols was non-linear; an increase of the land area with this soil type was associated with an exponential increase in C. burnetii seropositivity. This study provides new data on C. burnetii seroprevalence, information of its risk factors and a prevalence map that can be used for C. burnetii risk surveillance and control. The identification of environmental risk factors for C. burnetii exposure, and the increasing awareness of the zoonotic potential of the pathogen, calls for the need to enhance the existing collaborations for the surveillance and control of C. burnetii in line with the One Health framework. The evidence generated on the potential role of environmental factors can also be used to design nature-based interventions, such as replacement of vegetation in denuded areas, to reduce potential for the aerosolization of the pathogen. Livestock vaccination in the hotspots would also reduce animal infections and hence the contamination of the environment.