High Prevalence and New Genotype of Coxiella burnetii in Ticks Infesting Camels in Somalia

Coxiella burnetii is the causative agent of Q fever. It can infect animals, humans, and birds, as well as ticks, and it has a worldwide geographical distribution. To better understand the epidemiology of C. burnetii in Somalia, ticks infesting camels were collected from five different regions, including Bari, Nugaal, Mudug, Sool, and Sanaag, between January and March 2018. Collected ticks were tested for C. burnetii and Coxiella-like endosymbiont DNA by using IS1111, icd, and Com1-target PCR assays. Moreover, sequencing of the 16S-rRNA was conducted. Molecular characterization and typing were done by adaA-gene analysis and plasmid-type identification. Further typing was carried out by 14-marker Multi-Locus Variable-Number Tandem Repeats (MLVA/VNTR) analysis. The investigated ticks (n = 237) were identified as Hyalomma spp. (n = 227, 95.8%), Amblyomma spp. (n = 8, 3.4%), and Ripicephalus spp. (n = 2, 0.8%), and 59.1% (140/237) of them were positive for Coxiella spp. While Sanger sequencing and plasmid-type identification revealed a C. burnetii that harbours the QpRS-plasmid, MLVA/VNTR genotyping showed a new genotype which was initially named D21. In conclusion, this is the first report of C. burnetii in ticks in Somalia. The findings denote the possibility that C. burnetii is endemic in Somalia. Further epidemiological studies investigating samples from humans, animals, and ticks within the context of “One Health” are warranted.

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New Genotypes of Coxiella burnetii Circulating in Brazil and Argentina

Pathogens ◽

10.3390/pathogens9010030 ◽

2019 ◽

Vol 9 (1) ◽

pp. 30 ◽

Cited By ~ 1

Author(s):

Mateus de Souza Ribeiro Mioni ◽

Karim Sidi-Boumedine ◽

Felipe Morales Dalanezi ◽

Sâmea Fernandes Joaquim ◽

Renan Denadai ◽

...

Keyword(s):

Genetic Diversity ◽

South America ◽

Coxiella Burnetii ◽

Tandem Repeats ◽

Q Fever ◽

Variable Number ◽

Worldwide Distribution ◽

Variable Number Tandem Repeats ◽

Mlva Typing ◽

Multispacer Sequence Typing

Coxiella burnetii, the zoonotic agent of Q fever, has a worldwide distribution. Despite the vast information about the circulating genotypes in Europe and North America, there is a lack of data regarding C. burnetii strains in South America. Here, we show the presence of novel multispacer sequence typing (MST) genotypes of C. burnetii in two clusters detected in Brazil and Argentina that seem to be distant in parenthood. Argentinian strains isolated from a tick belongs to a new phylogenetic branch of C. burnetii, and the Brazilians strains may be related to MST 20 and 61. Multilocus variable number tandem repeats analysis (MLVA) typing provided a deeper resolution that may be related to host clusters of bovines, caprine, ovine, and ticks. Our results corroborate with the reports of geotypes of C. burnetii. Thus, we highlight the need for more genotyping studies to understand the genetic diversity of C. burnetii in South America and to confirm the hypothesis of host-related genotypes. We also emphasize the importance of virulence studies for a better understanding of Q fever in the region, which may help in surveillance and disease prevention programs.

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Molecular characteristics of Brucella melitensis isolates from humans in Qinghai Province, China

Infectious Diseases of Poverty ◽

10.1186/s40249-021-00829-0 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Zhi-Jun Zhao ◽

Ji-Quan Li ◽

Li Ma ◽

Hong-Mei Xue ◽

Xu-Xin Yang ◽

...

Keyword(s):

Tandem Repeats ◽

Brucella Melitensis ◽

Draft Genome ◽

Geographic Origin ◽

Variable Number ◽

Human Brucellosis ◽

Molecular Characteristics ◽

Whole Genome ◽

Qinghai Province ◽

Variable Number Tandem Repeats

Abstract Background The prevalence of human brucellosis in Qinghai Province of China has been increasing rapidly, with confirmed cases distributed across 31 counties. However, the epidemiology of brucellosis transmission has not been fully elucidated. To characterize the infecting strains isolated from humans, multiple-locus variable-number tandem repeats analysis (MLVA) and whole-genome single-nucleotide polymorphism (SNP)-based approaches were employed. Methods Strains were isolated from two males blood cultures that were confirmed Brucella melitensis positive following biotyping and MLVA. Genomic DNA was extracted from these two strains, and whole-genome sequencing was performed. Next, SNP-based phylogenetic analysis was performed to compare the two strains to 94 B. melitensis strains (complete genome and draft genome) retrieved from online databases. Results The two Brucella isolates were identified as B. melitensis biovar 3 (QH2019001 and QH2019005) following conventional biotyping and were found to have differences in their variable number tandem repeats (VNTRs) using MLVA-16. Phylogenetic examination assigned the 96 strains to five genotype groups, with QH2019001 and QH2019005 assigned to the same group, but different subgroups. Moreover, the QH2019005 strain was assigned to a new subgenotype, IIj, within genotype II. These findings were then combined to determine the geographic origin of the two Brucella strains. Conclusions Utilizing a whole-genome SNP-based approach enabled differences between the two B. melitensis strains to be more clearly resolved, and facilitated the elucidation of their different evolutionary histories. This approach also revealed that QH2019005 is a member of a new subgenotype (IIj) with an ancient origin in the eastern Mediterranean Sea.

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Slipped-Strand Mispairing at Noncontiguous Repeats in Poecilia reticulata: A Model for Minisatellite Birth

Genetics ◽

10.1093/genetics/155.3.1313 ◽

2000 ◽

Vol 155 (3) ◽

pp. 1313-1320 ◽

Cited By ~ 2

Author(s):

John S Taylor ◽

Felix Breden

Keyword(s):

Tandem Repeat ◽

Poecilia Reticulata ◽

Tandem Repeats ◽

Phylogenetic Reconstruction ◽

Variable Number ◽

Repeat Motif ◽

Raw Material ◽

Direct Repeats ◽

Mt Dna ◽

Variable Number Tandem Repeats

Abstract The standard slipped-strand mispairing (SSM) model for the formation of variable number tandem repeats (VNTRs) proposes that a few tandem repeats, produced by chance mutations, provide the “raw material” for VNTR expansion. However, this model is unlikely to explain the formation of VNTRs with long motifs (e.g., minisatellites), because the likelihood of a tandem repeat forming by chance decreases rapidly as the length of the repeat motif increases. Phylogenetic reconstruction of the birth of a mitochondrial (mt) DNA minisatellite in guppies suggests that VNTRs with long motifs can form as a consequence of SSM at noncontiguous repeats. VNTRs formed in this manner have motifs longer than the noncontiguous repeat originally formed by chance and are flanked by one unit of the original, noncontiguous repeat. SSM at noncontiguous repeats can therefore explain the birth of VNTRs with long motifs and the “imperfect” or “short direct” repeats frequently observed adjacent to both mtDNA and nuclear VNTRs.

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