91 research outputs found
Chlamydia psittaci st24: clonal strains of one health importance dominate in Australian horse, bird and human infections
Chlamydia psittaci is traditionally regarded as a globally distributed avian pathogen that can cause zoonotic spill-over. Molecular research has identified an extended global host range and significant genetic diversity. However, Australia has reported a reduced host range (avian, horse, and human) with a dominance of clonal strains, denoted ST24. To better understand the widespread of this strain type in Australia, multilocus sequence typing (MLST) and ompA genotyping were applied on samples from a range of hosts (avian, equine, marsupial, and bovine) from Australia. MLST confirms that clonal ST24 strains dominate infections of Australian psittacine and equine hosts (82/88; 93.18%). However, this study also found novel hosts (Australian white ibis, King parrots, racing pigeon, bovine, and a wallaby) and demonstrated that strain diversity does exist in Australia. The discovery of a C. psittaci novel strain (ST306) in a novel host, the Western brush wallaby, is the first detection in a marsupial. Analysis of the results of this study applied a multidisciplinary approach regarding Chlamydia infections, equine infectious disease, ecology, and One Health. Recommendations include an update for the descriptive framework of C. psittaci disease and cell biology work to inform pathogenicity and complement molecular epidemiologySusan I. Anstey, Vasilli Kasimov, Cheryl Jenkins, Alistair Legione, Joanne Devlin, Jemima Amery-Gale ... et al
An investigation of two significant infectious diseases in populations of Victorian koalas (Phascolarctos cinereus)
© 2017 Dr Alistair Raymond LegioneThe koala (Phascolarctos cinereus), an iconic Australian marsupial, is considered a vulnerable species in parts of Australia due to recent rapid population declines. The role of infectious diseases in population declines in northern koalas (New South Wales (NSW) and Queensland populations) has been highly studied.
Chlamydia pecorum and koala retrovirus (KoRV) have both been given considerable attention. C. pecorum in koalas is associated with infertility and blindness through infection of the urogenital tract and conjunctiva, respectively. The prevalence of C. pecorum in northern koalas is as high as 87%. Different genotypes of KoRV have been identified in northern koalas. KoRV-A has been identified in all northern koalas tested to date. KoRV-B appears to be less prevalent but has been implicated as a cause of neoplasia.
Molecular testing of C. pecorum and KoRV prevalence in Victoria, a southern population of koalas, has been limited. No genotyping studies have been undertaken on either organism in Victorian koalas. This thesis conducted an extensive survey of Victorian koalas across seven separate regions to establish a prevalence estimate for both C. pecorum and KoRV. A genotyping study for each pathogen was also completed.
The estimated prevalence of C. pecorum in Victorian koalas was 15.2% (125/820, 95% confidence interval (CI) 12.9, 17.9%). Molecular evidence of C. pecorum infection in French Island koalas was detected for the first time. Only a single ocular C. pecorum infection was identified in Victorian koalas (1/459). A total of six C. pecorum genotypes were detected, the majority of which were genotype B, which has only been detected in southern koalas. Three of the genotypes were novel, each of which were found in distinct populations. Male koalas were more likely to be infected than females. C. pecorum infection was associated with ‘wet bottom’ (a sign of urinary incontinence and inflammation) in male koalas and reproductive tract disease in female koalas.
Not all koalas with ‘wet bottom’ had detectable C. pecorum, suggesting another potential cause. Analysis of the genetic diversity of the bacteria present in urogenital tract samples from ten koalas, of which only five displayed wet bottom, identified 13 operational taxonomic units that occurred at a higher abundance in wet bottom-affected koalas. These bacterial families are of interest for future studies.
The genomes of 57 C. pecorum samples from koalas across Australia were sequenced and assembled. The results showed that C. pecorum genomes from southern koalas were distinct from those of northern koalas.
KoRV prevalence in Victorian koalas was 24.7% (160/648, 95% CI 21.5, 28.2%). Only KoRV-A was detected. Koalas with ‘wet bottom’ were almost twice as likely to have KoRV detected. There was no association between KoRV and C. pecorum detection.
This research highlights that Victorian koalas are experiencing a reduced burden of infection compared to northern koalas, and this may be a factor in southern populations outgrowing the available habitat resources in Victoria, compared to northern populations. Victorian koalas free from C. pecorum and KoRV infection could be sourced from over-abundant populations to assist re-establishment of populations where koalas have become locally extinct. Overall, this research provides valuable information for both future research and koala population management
Polychromophilus melanipherus and haemoplasma infections not associated with clinical signs in southern bent-winged bats (Miniopterus orianae bassanii) and eastern bent-winged bats (Miniopterus orianae oceanensis)
While bats are often viewed as carriers of infectious disease agents, little research has been conducted on the effects these pathogens may have on the bat populations themselves. The southern bent-winged bat (Miniopterus orianae bassanii) is a critically endangered subspecies endemic to south-eastern Australia. Population numbers of this bat have declined over the past 50 years, but the reasons for this are unclear. As part of a larger study to determine if disease could be a contributing factor to this decline, southern bent-winged bats from several locations in Victoria and South Australia were captured and examined for the presence of the blood parasite, Polychromophilus melanipherus, and haemoplasmas (Mycoplasma sp.). Results were compared with those obtained from populations of the more common, partially sympatric, eastern bent-winged bat (Miniopterus orianae oceanensis) from three different locations in Victoria. Both organisms were found in both subspecies (prevalence of P. melanipherus 60% by PCR for southern bent-winged bats compared with 46% for eastern bent-winged bats; prevalence of haemoplasmas 10% for southern bent-winged bats compared with 8% for eastern bent-winged bats), with no association between the probability of infection, body weight, abnormal blood parameters or any other indicators of ill health. However, Victorian southern bent-winged bats had heavier burdens of P. melanipherus than both the South Australian southern bent-winged bats and eastern bent-winged bats. Further investigations are required to determine if these differences are impacting population health. Keywords: bats, Haemoplasma, Miniopterus orianae bassanii, Miniopterus orianae oceanensis, Parasites, Polychromophilus melanipheru
Variation in the microbiome of the urogenital tract of Chlamydia-free female koalas (Phascolarctos cinereus) with and without 'wet bottom'
Koalas (Phascolarctos cinereus) are iconic Australian marsupials currently threatened by several processes, including infectious diseases and ecological disruption. Infection with Chlamydia pecorum, is considered a key driver of population decline. The clinical sign of 'wet bottom', a staining of the rump associated with urinary incontinence, is often caused by chlamydial urinary tract infections. However, wet bottom has been recorded in koalas free of C. pecorum, suggesting other causative agents in those individuals. We used 16S rRNA diversity profiling to investigate the microbiome of the urogenital tract of ten female koalas in order to identify potential causative agents of wet bottom, other than C. pecorum. Five urogenital samples were processed from koalas presenting with wet bottom and five were clinically normal. All koalas were negative for C. pecorum infection. We detected thirteen phyla across the ten samples, with Firmicutes occurring at the highest relative abundance (77.6%). The order Lactobacillales, within the Firmicutes, comprised 70.3% of the reads from all samples. After normalising reads using DESeq2 and testing for significant differences (P < 0.05), there were 25 operational taxonomic units (OTUs) more commonly found in one group over the other. The families Aerococcaceae and Tissierellaceae both had four significantly differentially abundant OTUs. These four Tissierellaceae OTUs were all significantly more abundant in koalas with wet bottom. This study provides the foundation for future investigations of causes of koala wet bottom, other than C. pecorum infection. This is of clinical relevance as wet bottom is often assumed to be caused by C. pecorum and treated accordingly. Our research highlights that other organisms may be causing wet bottom, and these potential aetiological agents need to be further investigated to fully address the problems this species faces
gbouras13/pharokka: v1.5.1
<h2>1.5.1 (2023-10-26)</h2>
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<li>Fixes <code>dnaapler</code> version to <code>>=0.4.0</code> with new changes to dnaapler</li>
<li>Adds <code>.svg</code> format output with <code>pharokka_plotter.py</code></li>
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Probiotic Yoghurt Enriched with Mango Peel Powder: Biotransformation of Phenolics and Modulation of Metabolomic Outputs after In Vitro Digestion and Colonic Fermentation
This study investigated the health-promoting effects and prebiotic functions of mango peel powder (MPP) both as a plain individual ingredient and when incorporated in yoghurt during simulated digestion and fermentation. The treatments included plain MPP, plain yoghurt (YA), yoghurt fortified with MPP (YB), and yoghurt fortified with MPP and lactic acid bacteria (YC), along with a blank (BL). The identification of polyphenols in the extracts of insoluble digesta and phenolic metabolites after the in vitro colonic fermentation were performed employing LC-ESI-QTOF-MS2. These extracts were also subjected to pH, microbial count, production of SCFA, and 16S rRNA analyses. The characterisation of phenolic profiles identified 62 phenolic compounds. Among these compounds, phenolic acids were the major compounds that underwent biotransformation via catabolic pathways such as ring fission, decarboxylation, and dehydroxylation. Changes in pH indicated that YC and MPP reduced the media pH from 6.27 and 6.33 to 4.50 and 4.53, respectively. This decline in pH was associated with significant increases in the LAB counts of these samples. The Bifidobacteria counts were 8.11 ± 0.89 and 8.02 ± 1.01 log CFU/g in YC and MPP, respectively, after 72 h of colonic fermentation. Results also showed that the presence of MPP imparted significant variations in the contents and profiles of individual short chain fatty acids (SCFA) with more predominant production of most SCFA in the MPP and YC treatments. The 16s rRNA sequencing data indicated a highly distinctive microbial population associated with YC in terms of relative abundance. These findings suggested MPP as a promising ingredient for utilisation in functional food formulations aiming to enhance gut health
Detection of Coxiella burnetii and equine herpesvirus 1, but not Leptospira spp. or Toxoplasma gondii, in cases of equine abortion in Australia - a 25 year retrospective study
Equine abortion is a cause of severe economic loss to the equine industry. Equine herpesvirus 1 is considered a primary cause of infectious abortion in horses, however other infectious agents can also cause abortion. Abortions due to zoonotic pathogens have implications for both human and animal health. We determined the prevalence of Coxiella burnetii, Leptospira spp. and Toxoplasma gondii in 600 aborted equine foetal tissues that were submitted to our diagnostic laboratories at the University of Melbourne from 1994 to 2019. Using qPCR we found that the prevalence of C. burnetii was 4%. The highest annual incidence of C. burnetii was observed between 1997-2003 and 2016-2018. The prevalence of C. burnetii in Victoria and New South Wales was 3% and 6% respectively. All the samples tested negative for Leptospira spp. and Toxoplasma gondii DNA. Equine herpesvirus 1 DNA was detected at a prevalence of 3%. This study has provided evidence for the presence of C. burnetii in equine aborted foetal tissues in Australia, but the role of C. burnetii as potential cause of abortion in Australia requires further investigation. C. burnetii is a zoonotic disease agent that causes the disease 'Q fever' in humans. We recommend that appropriate protective measures should be considered when handling material associated with equine abortions to reduce the risk of becoming infected with C. burnetii
Chlamydia Psittaci ST24: clonal strains of One Health importance dominate in Australian horse, bird and human infections
Chlamydia psittaci is traditionally regarded as a globally distributed avian pathogen that can cause zoonotic spill-over. Molecular research has identified an extended global host range and significant genetic diversity. However, Australia has reported a reduced host range (avian, horse, and human) with a dominance of clonal strains, denoted ST24. To better understand the widespread of this strain type in Australia, multilocus sequence typing (MLST) and ompA genotyping were applied on samples from a range of hosts (avian, equine, marsupial, and bovine) from Australia. MLST confirms that clonal ST24 strains dominate infections of Australian psittacine and equine hosts (82/88; 93.18%). However, this study also found novel hosts (Australian white ibis, King parrots, racing pigeon, bovine, and a wallaby) and demonstrated that strain diversity does exist in Australia. The discovery of a C. psittaci novel strain (ST306) in a novel host, the Western brush wallaby, is the first detection in a marsupial. Analysis of the results of this study applied a multidisciplinary approach regarding Chlamydia infections, equine infectious disease, ecology, and One Health. Recommendations include an update for the descriptive framework of C. psittaci disease and cell biology work to inform pathogenicity and complement molecular epidemiology
Full Genome Analysis of Australian Infectious Bronchitis Viruses Suggests Frequent Recombination Events between Vaccine Strains and Multiple Phylogenetically Distant Avian Coronaviruses of Unknown Origin
Australian strains of infectious bronchitis virus (IBV) have been evolving independently for many years, with control achieved by vaccination with local attenuated strains. Previous studies have documented the emergence of recombinants over the last 20 years, with the most recent one, Ck/Aus/N1/08, detected in 2008. These recombinants did not appear to be controlled by the vaccines currently in use.
In this study we sequenced the complete genomes of three emergent Australian strains of IBV (IBV/Ck/Aus/N1/88, IBV/Ck/Aus/N1/03 and IBV/Ck/Aus/N1/08) and a previously incompletely characterised vaccine strain, IBV/Ck/Aus/Armidale, and compared them to the genome of the vaccine strain VicS. We detected multiple recombination events throughout the genome between wild type viruses and the vaccine strains in all three emergent isolates. Moreover, we found that strain N1/88 was not entirely exogenous, as was previously hypothesised. Rather, it originated from a recombination event involving the VicS vaccine strain. The S glycoprotein genes of N1/88 and N1/03 were known to be genetically distinct from previously characterised circulating strains and from each other, and the original donors of these genes remains unknown. The S1 glycoprotein gene of N1/88, a subgroup 2 strain, shares a high nucleotide identity with the sequence of the S1 gene of the recent isolate N1/08. As the subgroup 2 strains have not been isolated for at least 20 years, it appears likely that an unknown avian coronavirus that was the donor of the S1 glycoprotein sequence of N1/88 in the 1980s is still recombining with IBV strains in the field
Completing the Genome Sequence of Chlamydia pecorum Strains MC/MarsBar and DBDeUG: New Insights into This Enigmatic Koala (Phascolarctos cinereus) Pathogen
Chlamydia pecorum, an obligate intracellular pathogen, causes significant morbidity and mortality in livestock and the koala (Phascolarctos cinereus). A variety of C. pecorum gene-centric molecular studies have revealed important observations about infection dynamics and genetic diversity in both koala and livestock hosts. In contrast to a variety of C. pecorum molecular studies, to date, only four complete and 16 draft genomes have been published. Of those, only five draft genomes are from koalas. Here, using whole-genome sequencing and a comparative genomics approach, we describe the first two complete C. pecorum genomes collected from diseased koalas. A de novo assembly of DBDeUG_2018 and MC/MarsBar_2018 resolved the chromosomes and chlamydial plasmids each as single, circular contigs. Robust phylogenomic analyses indicate biogeographical separation between strains from northern and southern koala populations, and between strains infecting koala and livestock hosts. Comparative genomics between koala strains identified new, unique, and shared loci that accumulate single-nucleotide polymorphisms and separate between northern and southern, and within northern koala strains. Furthermore, we predicted novel type III secretion system effectors. This investigation constitutes a comprehensive genome-wide comparison between C. pecorum from koalas and provides improvements to annotations of a C. pecorum reference genome. These findings lay the foundations for identifying and understanding host specificity and adaptation behind chlamydial infections affecting koalas
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