First molecular survey and identification ofAnaplasmaspp. in white yaks (Bos grunniens) in China

Parasitology ◽  
2016 ◽  
Vol 143 (6) ◽  
pp. 686-691 ◽  
Author(s):  
JIFEI YANG ◽  
ZHIJIE LIU ◽  
QINGLI NIU ◽  
JUNLONG LIU ◽  
GUIQUAN GUAN ◽  
...  

SUMMARYAnaplasmosis is caused by a group of obligate intracellular bacteria in the genusAnaplasma, which are transmitted by ticks and infect humans, domestic animals and wildlife. This study was conducted to determine the prevalence and molecular characterization ofAnaplasmaspp. in semi-wild white yaks sampled in Tianzhu Tibetan Autonomous County, northwest China. Out of 332 samples tested, 35 (10·9%) were positive forAnaplasmaspp. The positive rates were 6·2% (20/322) and 5·3% (17/322) forAnaplasma bovisandAnaplasma phagocytophilumin white yaks, respectively. None of the sample was positive forAnaplasma marginale. Two (0·6%) samples were simultaneously positive toA. bovisandA. phagocytophilum. Sequence analysis of the 16S rRNA gene revealed two genotypes (ApG1 and ApG2) ofA. phagocytophilumand two sequence types (ST1 and ST2) ofA. bovisin white yaks. This study is the first to document the presence ofAnaplasmain white yaks. Our findings extend the host range forAnaplasmaspecies and provide more valuable information for the control and management of anaplasmosis in white yaks.

2021 ◽  
Author(s):  
Arkaprabha Banerjee ◽  
David E Nelson

Abstract Multiple species of obligate intracellular bacteria in the genus Chlamydia are important veterinary and/or human pathogens. These pathogens all share similar biphasic developmental cycles and transition between intracellular vegetative reticulate bodies and infectious elementary forms, but vary substantially in their host preferences and pathogenic potential. A lack of tools for genetic engineering of these organisms has long been an impediment to the study of their biology and pathogenesis. However, the refinement of approaches developed in C. trachomatis over the last ten years, and adaptation of some of these approaches to other Chlamydia spp. in just the last few years, has opened exciting new possibilities for studying this ubiquitous group of important pathogens.


2018 ◽  
Vol 201 (2) ◽  
Author(s):  
Nicholas A. Wood ◽  
Krystal Y. Chung ◽  
Amanda M. Blocker ◽  
Nathalia Rodrigues de Almeida ◽  
Martin Conda-Sheridan ◽  
...  

ABSTRACTMembers ofChlamydiaare obligate intracellular bacteria that differentiate between two distinct functional and morphological forms during their developmental cycle, elementary bodies (EBs) and reticulate bodies (RBs). EBs are nondividing small electron-dense forms that infect host cells. RBs are larger noninfectious replicative forms that develop within a membrane-bound vesicle, termed an inclusion. Given the unique properties of each developmental form of this bacterium, we hypothesized that the Clp protease system plays an integral role in proteomic turnover by degrading specific proteins from one developmental form or the other.Chlamydiaspp. have five uncharacterizedclpgenes,clpX,clpC, twoclpPparalogs, andclpB. In other bacteria, ClpC and ClpX are ATPases that unfold and feed proteins into the ClpP protease to be degraded, and ClpB is a deaggregase. Here, we focused on characterizing the ClpP paralogs. Transcriptional analyses and immunoblotting determined that these genes are expressed midcycle. Bioinformatic analyses of these proteins identified key residues important for activity. Overexpression of inactiveclpPmutants inChlamydiaspp. suggested independent function of each ClpP paralog. To further probe these differences, we determined interactions between the ClpP proteins using bacterial two-hybrid assays and native gel analysis of recombinant proteins. Homotypic interactions of the ClpP proteins, but not heterotypic interactions between the ClpP paralogs, were detected. Interestingly, protease activity of ClpP2, but not ClpP1, was detectedin vitro. This activity was stimulated by antibiotics known to activate ClpP, which also blocked chlamydial growth. Our data suggest the chlamydial ClpP paralogs likely serve distinct and critical roles in this important pathogen.IMPORTANCEChlamydia trachomatisis the leading cause of preventable infectious blindness and of bacterial sexually transmitted infections worldwide. Chlamydiae are developmentally regulated obligate intracellular pathogens that alternate between two functional and morphologic forms, with distinct repertoires of proteins. We hypothesize that protein degradation is a critical aspect to the developmental cycle. A key system involved in protein turnover in bacteria is the Clp protease system. Here, we characterized the two chlamydial ClpP paralogs by examining their expression inChlamydiaspp., their ability to oligomerize, and their proteolytic activity. This work will help understand the evolutionarily diverse Clp proteases in the context of intracellular organisms, which may aid in the study of other clinically relevant intracellular bacteria.


2009 ◽  
Vol 192 (3) ◽  
pp. 834-840 ◽  
Author(s):  
Cheryl M. Vahling ◽  
Yongping Duan ◽  
Hong Lin

ABSTRACT ATP/ADP translocases transport ATP across a lipid bilayer, which is normally impermeable to this molecule due to its size and charge. These transport proteins appear to be unique to mitochondria, plant plastids, and obligate intracellular bacteria. All bacterial ATP/ADP translocases characterized thus far have been found in endosymbionts of protozoa or pathogens of higher-order animals, including humans. A putative ATP/ADP translocase was uncovered during the genomic sequencing of the intracellular plant pathogen “Candidatus Liberibacter asiaticus,” the causal agent of citrus huanglongbing. Bioinformatic analysis of the protein revealed 12 transmembrane helices and predicted an isoelectric point of 9.4, both of which are characteristic of this family of proteins. The “Ca. Liberibacter asiaticus” gene (nttA) encoding the translocase was subsequently expressed in Escherichia coli and shown to enable E. coli to import ATP directly into the cell. Competition assays with the heterologous E. coli system demonstrated that the translocase was highly specific for ATP and ADP but that other nucleotides, if present in high concentrations, could also be taken up and/or block the ability of the translocase to import ATP. In addition, a protein homologous to NttA was identified in “Ca. Liberibacter solanacearum,” the bacterium associated with potato zebra chip disease. This is the first reported characterization of an ATP translocase from “Ca. Liberibacter asiaticus,” indicating that some intracellular bacteria of plants also have the potential to import ATP directly from their environment.


2017 ◽  
Vol 84 (3) ◽  
Author(s):  
Irene Cano ◽  
Ronny van Aerle ◽  
Stuart Ross ◽  
David W. Verner-Jeffreys ◽  
Richard K. Paley ◽  
...  

ABSTRACTOne of the fastest growing fisheries in the UK is the king scallop (Pecten maximusL.), also currently rated as the second most valuable fishery. Mass mortality events in scallops have been reported worldwide, often with the causative agent(s) remaining uncharacterized. In May 2013 and 2014, two mass mortality events affecting king scallops were recorded in the Lyme Bay marine protected area (MPA) in Southwest England. Histopathological examination showed gill epithelial tissues infected with intracellular microcolonies (IMCs) of bacteria resemblingRickettsia-like organisms (RLOs), often with bacteria released in vascular spaces. Large colonies were associated with cellular and tissue disruption of the gills. Ultrastructural examination confirmed the intracellular location of these organisms in affected epithelial cells. The 16S rRNA gene sequences of the putative IMCs obtained from infected king scallop gill samples, collected from both mortality events, were identical and had a 99.4% identity to 16S rRNA gene sequences obtained from “CandidatusEndonucleobacter bathymodioli” and 95% withEndozoicomonasspecies.In situhybridization assays using 16S rRNA gene probes confirmed the presence of the sequenced IMC gene in the gill tissues. Additional DNA sequences of the bacterium were obtained using high-throughput (Illumina) sequencing, and bioinformatic analysis identified over 1,000 genes with high similarity to protein sequences fromEndozoicomonasspp. (ranging from 77 to 87% identity). Specific PCR assays were developed and applied to screen for the presence of IMC 16S rRNA gene sequences in king scallop gill tissues collected at the Lyme Bay MPA during 2015 and 2016. There was 100% prevalence of the IMCs in these gill tissues, and the 16S rRNA gene sequences identified were identical to the sequence found during the previous mortality event.IMPORTANCEMolluscan mass mortalities associated with IMCs have been reported worldwide for many years; however, apart from histological and ultrastructural characterization, characterization of the etiological agents is limited. In the present work, we provide detailed molecular characterization of anEndozoicomonas-like organism (ELO) associated with an important commercial scallop species.


Author(s):  
Philippa C. Matthews

This chapter consists of short notes, diagrams, and tables to summarize infections caused by obligate intracellular bacteria. The chapter begins with a classification system to divide these organisms into Rickettsia, Anaplasma, Chlamydia, Coxiella, and Bartonella species. Separate sections then follow on the infections of most clinical significance for the tropics and subtropics, including the typhus group (caused by rickettsial infection) and Q fever. For ease of reference, each topic is broken down into sections, including classification, epidemiology, microbiology, pathophysiology, clinical syndromes, diagnosis, treatment, and prevention.


Parasite ◽  
2020 ◽  
Vol 27 ◽  
pp. 62
Author(s):  
Yilin Wang ◽  
Jianke Cao ◽  
Yankai Chang ◽  
Fuchang Yu ◽  
Sumei Zhang ◽  
...  

Cryptosporidium spp. and Giardia duodenalis are common gastrointestinal parasites with a broad range of hosts, including humans, livestock, and wildlife. To examine the infection status and assess the zoonotic potential of Cryptosporidium spp. and G. duodenalis in dairy cattle in Gansu, China, a total of 1414 fecal samples were collected from the rectum, with one sample collected from each individual animal. All the samples were tested using nested PCR based on the small subunit ribosomal RNA (SSU rRNA) gene of Cryptosporidium spp. and G. duodenalis. The overall infection rates of Cryptosporidium spp. and Giardia duodenalis were 4.2% (n = 59) and 1.0% (n = 14), respectively. Four Cryptosporidium species were identified: C. andersoni (n = 42), C. parvum (n = 12), C. bovis (n = 5), and C. ryanae (n = 1). In further analyses of subtypes of C. parvum isolates based on the 60 kDa glycoprotein (gp60) gene, five were successfully subtyped as IIdA19G1 (n = 4) and IIdA15G1 (n = 1). All 14 G. duodenalis isolates were identified as assemblage E using the triosephosphate isomerase (tpi) gene. The relatively low positive rates of Cryptosporidium spp. and G. duodenalis detected here and the predominance of non-human pathogenic species/assemblages of these parasites indicated their unique transmission dynamics in this area and the low level of threat posed to public health. However, continuous monitoring and further studies of these parasites should be conducted for the prevention and control of these pathogens.


2016 ◽  
Vol 2 (1 and 2) ◽  
pp. 37-42 ◽  
Author(s):  
Ashutosh Yadav ◽  
Abhay Raj ◽  
Ram Naresh Bharagava

In this study, an enterobacterium was isolated from treated tannery wastewater and characterized as gram-negative, rod shaped, motile, and lactose fermenting bacterium. Further, based on the 16S rRNA gene sequence analysis, the bacterium was identified as Pantoea sp. with accession number The antibiotic and heavy KJ576899. metal resistant property of isolated bacterium was investigated by the disk diffusion method on Muller-Hinton and nutrient agar medium amended with the increasing concentrations of various toxic metal ions, respectively. Results showed that the isolated bacterium was sensitive for amikacin, ampicillin, cefepime, cetriaxone, chloramphenicol, levofloxacin, meropenem, nalidixic acid, piperacillin and tobramycin, resistant for aztreonam, carbenicillin, cefotaxime, ceftazidime, ciprofloxacin, cotrimoxazole, imepenam, moxifloxacin, streptomycin and tetracycline, but intermediate for amoxicillin and gentamicin. In addition, the bacterium also showed the Minimum Inhibitory Concentration (MIC) values of 250, 500, 160, 190, 600, 700, 500, 380, 600 and 350 μg ml-1 forCu, Cr, Cd, Co, Zn, Fe, Ni, Pb, Mo and As, respectively with a plasmid DNA of 33.5 kb. This multi-drug and multi-metal resistant bacterium can be used as a potential agent for the bioremediation of metal contaminated sites.


2015 ◽  
Vol 82 (2) ◽  
pp. 659-670 ◽  
Author(s):  
Sebastian Hess ◽  
Andreas Suthaus ◽  
Michael Melkonian

ABSTRACTTheRickettsiales(Alphaproteobacteria) are obligate intracellular bacteria that colonize a wide range of eukaryotic hosts, including diverse metazoa and protists. Here, we characterize rickettsial endosymbionts discovered in the cytoplasm of the algivorous amoeboflagellatesViridiraptor invadensandOrciraptor agilis(Viridiraptoridae, Cercozoa, Rhizaria), supplying evidence of free-living, phagotrophic members of the Cercozoa serving as hosts forRickettsiales. According to 16S rRNA gene phylogenies, the bacteria represent two closely related but distinct genotypes within a deep-branching rickettsial clade, which contains the genera “CandidatusOdyssella,” “CandidatusParacaedibacter,” and “CandidatusCaptivus.” Using the full-cycle rRNA approach, we detected the novel bacteria in four of nine viridiraptorid strains tested. Furthermore, two specific oligonucleotide probes with a single-nucleotide-difference discriminated both bacterial genotypes by fluorescencein situhybridization (FISH). We establish the candidate species “CandidatusFinniella inopinata” (found inViridiraptor invadens) and “CandidatusFinniella lucida” (found inOrciraptor agilis) for the novel bacteria and propose a new, provisional family ofRickettsiales, “CandidatusParacaedibacteraceae.”


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