The draft genome sequence of “Candidatus Liberibacter asiaticus” strain A4, isolated from a mandarin citrus in Guangdong, People’s Republic of China, is reported. The A4 strain has a genome size of 1,208,625 bp, G+C content of 36.4%, 1,107 predicted open reading frames, and 53 RNA genes.
Huanglongbing (HLB) is a highly destructive citrus disease and is associated with a nonculturable bacterium, ‘Candidatus Liberibacter asiaticus’. ‘Ca. L. asiaticus’ in the United States was first found in Florida in 2005 and is now endemic there. In California, ‘Ca. L. asiaticus’ was first detected in Hacienda Heights in Los Angeles County in 2012 and has now been detected in multiple urban locations in southern California. Knowledge of ‘Ca. L. asiaticus’ strain diversity in California is important for HLB management. In this study, genomic diversity among 10 ‘Ca. L. asiaticus’ strains from six California locations were analyzed using a next-generation sequencing (NGS) (Illumina MiSeq and HiSeq) approach. Draft genome sequences of ‘Ca. L. asiaticus’ strains were assembled. Sequences of the 16S ribosomal RNA gene and nrdB confirmed ‘Ca. L. asiaticus’ identity. Prophages were detected in all ‘Ca. L. asiaticus’ strains. The California ‘Ca. L. asiaticus’ strains formed four prophage typing groups (PTGs): PTG1, with type 1 prophage only (strains from Anaheim, San Gabriel, and Riverside); PTG2, with type 2 prophage only (strains from Hacienda Heights); PTG1-3, with both type 1 and 3 prophages (a strain from Cerritos); and PTG1-2, with both type 1 and type 2 prophages (a strain from La Habra). Analyses of the terL sequence showed that all California ‘Ca. L. asiaticus’ strains were not introduced from Florida but likely from locations in Asia. Miniature inverted-repeat transposable elements were found in all ‘Ca. L. asiaticus’ strains, yet, a jumping-out event was detected in the ‘Ca. L. asiaticus’ strain from Cerritos. Altogether, this study demonstrated that the NGS approach focusing on prophage variation was sensitive and effective in revealing diversity of ‘Ca. L. asiaticus’ strains in California.
Background: On October 30, 2020, piglets and sows in the farrowing house of a pig farm in Jiangxi showed clinical symptoms such as anorexia, watery diarrhea, and vomiting. Epidemiological test, clinical necropsy, and RT-PCR test were carried out on the pig farm for diagnosis. After comprehensive considerations, the disease was judged as porcine epidemic diarrhea virus infection.Results: Thereafter, a series of comprehensive prevention and control measures such as emergency vaccination with autogenous vaccines were adopted. Half a month after inoculation with autogenous vaccines for the farm, the mortality rate of newborn piglets in the farrowing house began to decline, and production gradually returned to being stable. The second-generation sequencing analysis and phylogenetic analysis showed that the porcine epidemic diarrhea virus (PEDV) sequence obtained from the stool and small intestine samples of the diseased pigs on the farm was 97.8% homologous to the vaccine strain. At the same time, antibody testing found that the vaccinated pigs on the pig farm had satisfactory immune response.Conclusion: This case indicated that the PEDV outbreak on the pig farm might aggravate owing to the strain being mutated and could escape the immune protection of the existing vaccine. This case has accumulated technical data for the clinical prevention and control of porcine epidemic diarrhea.
BackgroundThere are only limited number of reports on molecular epidemiology of Cryptosporidium spp. and Giardia duodenalis in dogs and cats in China. This study was conducted to assess the infection rates, genetic identity, and public health potential of these parasites in dogs and cats in Guangdong, China.MethodsPCR and sequence analyses were used to identify and genotype Cryptosporidium spp. and G. duodenalis in fecal samples from 641 dogs and 418 cats in Guangdong. Chi-square test and odds ratio analysis were used to compare the occurrence rates of these pathogens and identify risk factors for infection.ResultsThe overall infection rates of Cryptosporidium spp. and G. duodenalis were 6.9% (44/641) and 9.4% (60/641) in dogs, and 6.2% (26/418) and 3.6% (15/418) in cats. Purebred cats (12.4%; χ2 = 5.110, OR = 2.8, P = 0.024) and dogs (10.8%; χ2 = 5.597, OR = 4.8, P = 0.018) were more likely to be infected by Cryptosporidium spp. and G. duodenalis, respectively. Dogs (12.0%; χ2 = 7.589, OR = 2.6, P = 0.006) and cats (13.6%; χ2 = 8.235, OR = 3.5, P = 0.004) under 6 months had significantly higher infection rates of Cryptosporidium spp. than older animals. Household (13.9%; χ2 = 10.279, OR = 2.6, P = 0.008) and pet shop dogs (11.0%; χ2 = 7.182, OR = 2.0, P = 0.048) had higher occurrence of Cryptosporidium spp., as was the case for G. duodenalis occurrence in experimental dogs (13.4%; χ2 = 9.223, OR = 1.9, P = 0.017). Cryptosporidium canis (n = 42), C. muris (n = 1) and Cryptosporidium rat genotype IV (n = 1) were identified in dogs, while C. felis (n = 21), C. parvum (n = 3), C. muris (n = 1) and Cryptosporidium rat genotype IV (n = 1) were identified in cats. In contrast, the canine-specific assemblages C (n = 27) and D (n = 26) and the feline-specific assemblage F (n = 14) were almost exclusively the only genotypes of G. duodenalis in dogs and cats, respectively. There was no significant difference in infection rates of Cryptosporidium spp. and G. duodenalis between diarrheal and non-diarrheal pets.ConclusionsWhile domestic pets in Guangdong are infected with zoonotic Cryptosporidium species, they are mainly infected with host-specific G. duodenalis genotypes. Risk factors for infections differ between Cryptosporidium spp. and G. duodenalis and between dogs and cats.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.