Genome-Wide Analysis of the Emerging Infection with Mycobacterium avium Subspecies paratuberculosis in the Arabian Camels (Camelus dromedarius)

Mycobacterium avium subspecies paratuberculosis (M. ap) is the causative agent of paratuberculosis or Johne's disease (JD) in herbivores with potential involvement in cases of Crohn's disease in humans. JD is spread worldwide and is economically important for both beef and dairy industries. Generally, pathogenic ovine strains (M. ap-S) are mainly found in sheep while bovine strains (M. ap-C) infect other ruminants (e.g. cattle, goat, deer), as well as sheep. In an effort to characterize this emerging infection in dromedary/Arabian camels, we successfully cultured M. ap from several samples collected from infected camels suffering from chronic, intermittent diarrhea suggestive of JD. Gene-based typing of isolates indicated that all isolates belong to sheep lineage of strains of M. ap (M. ap-S), suggesting a putative transmission from infected sheep herds. Screening sheep and goat herds associated with camels identified the circulation of this type in sheep but not goats. The current genome-wide analysis recognizes these camel isolates as a sub-lineage of the sheep strain with a significant number of single nucleotide polymorphisms (SNPs) between sheep and camel isolates (∼1000 SNPs). Such polymorphism could represent geographical differences among isolates or host adaptation of M. ap during camel infection. To our knowledge, this is the first attempt to examine the genomic basis of this emerging infection in camels with implications on the evolution of this important pathogen. The sequenced genomes of M. ap isolates from camels will further assist our efforts to understand JD pathogenesis and the dynamic of disease transmission across animal species

Lack of middle east respiratory syndrome coronavirus transmission from infected camels

© 2015, Centers for Disease Control and Prevention (CDC). All rights reserved. To determine risk for Middle East respiratory syndrome coronavirus transmission from camels to humans, we tested serum from 191 persons with various levels of exposure to an infected dromedary herd. We found no serologic evidence of human infection, suggesting that zoonotic transmission of this virus from dromedaries is rare.Link_to_subscribed_fulltex

Histological analysis of camel samples collected from animals suffering from Johne's disease.

<p>A) A representative of lymph node thin section stained with H&E showing diffuse granulomatous response (arrows). B) A lymph node section stained with Zeil-Neelsen stain showing high level of acid-fast bacilli. C) A representative of intestinal section stained with H&E showing aggregates of lymphatic infiltration (arrows). D) An intestinal section stained with Zeil-Neelsen stain showing patches of acid-fast bacilli. Size bars are included in the bottom of each section.</p

List of genes with high number of SNPs in <i>M. ap</i> JQ5 compared to <i>M. ap</i> K-10.

<p>List of genes with high number of SNPs in <i>M. ap</i> JQ5 compared to <i>M. ap</i> K-10.</p

Species-level typing of mycobacterial isolates from camels.

<p>Ethidium bromide stained 2% agarose gel of PCR amplicons of the <i>hsp65</i> gene, following restriction enzyme analysis (REA) with <i>Pst</i>I. For each set, both undigested and digested products (second lane) are shown. A 100-bp Molecular size marker is shown in the first lane.</p

Circular map of the newly identified SNPs and indels in camel isolate JQ5 relative to the <i>M. ap</i> K-10 strain [<b>51</b>].

<p>The outer circle shows the genomic scale. The second circle shows the location of the 4,395 ORFs in the <i>M. ap</i> K-10 genome. Genes (magenta) on the forward strand are shown outside of the baseline; genes (olivegreen) on the reverse strand are shown inside of the baseline. Inner circles show all indels (blue), synonymous SNPs (orange), and nonsynonymous SNPs (lime) identified in <i>M. ap</i> of camel origin. The figure was generated with GenVision software (DNAStar, Madison, WI).</p

Summary of next generation sequencing results.

<p>Summary of next generation sequencing results.</p

IS<i>1311</i> polymorphisms in <i>M.av</i> and within <i>M.ap</i> strains.

<p>IS<i>1311</i> polymorphisms in <i>M.av</i> and within <i>M.ap</i> strains.</p