Evaluation of Anaplasma spp. seroprevalence in dogs and association with incidence of human anaplasmosis.

Point-of-care (POC) ELISA tests are routinely used in US veterinary practices to screen canine patients for antibodies to tick-transmitted pathogens. Results are also used to monitor spatial and temporal trends in canine seroprevalence, and these data can build awareness of the risk to humans of tick-transmitted diseases such as Lyme disease and anaplasmosis. This study utilized a second-generation test that has incorporated additional Anaplasma-specific peptides into a commercial POC ELISA test to allow detection of Anaplasma spp. antibodies earlier post-infection. A convenience population consisting of 19,894 canine samples from a US commercial diagnostic laboratory were tested using the second-generation POC ELISA test to describe regional Anaplasma spp. canine seroprevalence and assess correlation to anaplasmosis cases reported to Centers for Disease Control and Prevention by state. Antibodies to Anaplasma spp. were detected in 1646 samples (8.3%) with the Northeast and Midwest US census regions having the highest proportion of positive samples. At the state level, a significant correlation was found between canine Anaplasma spp. seroprevalence and human anaplasmosis incidence (r2 = 0.64). Although estimates of canine Anaplasma spp. seroprevalence presented here using the second-generation POC ELISA are generally increased, especially in the Northeast and Midwest, the regional distribution of canine samples testing positive for Anaplasma spp. antibodies is consistent with previous reports. The observed correlation with human anaplasmosis incidence indicates that results from the second-generation POC ELISA will continue to add value in epidemiological assessment of human anaplasmosis risk.

Distribution of the feline lungworm Aelurostrongylus abstrusus in the USA based on fecal testing.

OBJECTIVES: The aim of this study was to compile commercial reference laboratory data over a 10-year period to determine the distribution of Aelurostrongylus abstrusus, commonly known as feline lungworm, within the USA based on widespread fecal testing in cats. METHODS: The results of 3,610,455 feline ova and parasite (O&P) zinc sulfate centrifugation fecal flotation tests performed at IDEXX Reference Laboratories in the USA from January 2008 to December 2017 were compiled and sorted for tests positive for A abstrusus larvae. The results of 3625 Baermann tests, currently considered the gold standard diagnostic for feline lungworm, were also retrieved from the same period. RESULTS: Of the tests performed, 4721 (0.13%) feline O&P zinc sulfate centrifugation fecal flotation tests and 75 (2.07%) of the Baermann tests conducted were positive for the presence of A abstrusus larvae. The O&P data revealed a significant association between infection status and sex, while male cats in both the O&P and Baermann data sets had a higher risk of A abstrusus infection than females. Significant variation in positive rates were observed by region and most positive cases were clustered in the Northeast, Midwest and West regions of the USA. CONCLUSIONS AND RELEVANCE: This study highlights the distribution of feline lungworm in the USA and the limitations of using current testing to diagnose this infection. The introduction of higher throughput, less labor-intensive diagnostic methods could help increase awareness of this parasite among veterinary professionals, achieve a greater understanding of epidemiological factors, and improve the care and treatment for clinically ill feline patients.

Characterization of canthaxanthin biosynthesis genes from an uncultured marine bacterium.

Carotenoids are isoprenoid pigments synthesized in plants, fungi, bacteria and archaea, with roles in light harvesting, protection from stress, and membrane and protein structures. To characterize carotenoid biosynthesis genes from oceanic microbes, a fosmid library derived from microbial samples collected in surface water of the Pacific Ocean was screened in Escherichia coli for pigment-expressing recombinant strains. One DNA fragment enabled production of a bright orange pigment, and was analysed further by sequence analysis and phenotypic characterization. The cloned DNA encoded a five-gene cluster predicted to be involved in the synthesis of canthaxanthin, a ketolated carotenoid. Each of these genes was inactivated by insertion of a transposon, and the biochemical function of each gene product was confirmed. Sequencing of related fosmids generated a 67 kb genomic contig, and comparative analyses suggested that the DNA may originate from a deltaproteobacterium. The carotenoid biosynthesis genes described here are related to well-characterized families of carotenoid biosynthesis genes, but also indicate that the organism harbouring them is only distantly related to any previously characterized bacterial types.