• Title/Summary/Keyword: Pathogen mutation

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Molecular subtyping and antimicrobial susceptibility of Streptococcus dysgalactiae subspecies equisimilis isolates from clinically diseased pigs

  • Oh, Sang-Ik;Kim, Jong Wan;Kim, Jongho;So, Byungjae;Kim, Bumseok;Kim, Ha-Young
    • Journal of Veterinary Science
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    • v.21 no.4
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    • pp.57.1-57.11
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    • 2020
  • Background: Streptococcus dysgalactiae subspecies equisimilis (SDSE) acts as an etiological agent for lameness, neurological signs, and high mortality in pigs. Despite its importance in pig industries and zoonotic potential, little is known about the effects of this pathogen. Objectives: This study aimed to determine the molecular characteristics and antimicrobial resistance of SDSE strains isolated from diseased pigs. Methods: A total 11 SDSE isolates were obtained from diseased pigs. Bacterial identification, PCR for virulence genes, emm typing, and antimicrobial resistance genes, multilocus sequence typing, and antimicrobial susceptibility test were performed. Results: Nine isolates were from piglets, and 8 showed lameness, sudden death, or neurological signs. The isolates were PCR-positive for sla (100%), sagA (100%), and scpA (45.5%), and only 1 isolate amplified the emm gene (stL2764). Eight different sequence types were detected, categorized into 2 clonal complexes and 4 singletons. All the isolates in this study were included in a small cluster, which also contained other strains derived from humans and horses. The minimum inhibitory concentrations for the tested beta-lactams were low, while those for macrolides, tetracyclines, and fluoroquinolones were relatively high. PCR analysis of the macrolide and tetracycline resistance genes demonstrated that the isolates carried erm(B) (18.2%, n = 2), mef(A/E) (9.1%, n = 1), tet(M) (18.2%, n = 2), and tet(O) (90.2%, n = 10). Two isolates presented a mutation in parC, which is associated with fluoroquinolone resistance. Conclusion: This study provided insight into swine-derived SDSE, as it is related to veterinary medicine, and elucidated its zoonotic potential, in the context of molecular epidemiology and antimicrobial resistance in public health.

Molecular diversity of the VP2 of Carnivore protoparvovirus 1 (CPV-2) of fecal samples from Bogotá

  • Galvis, Cristian Camilo;Jimenez-Villegas, Tatiana;Romero, Diana Patricia Reyes;Velandia, Alejandro;Taniwaki, Sueli;Silva, Sheila Oliveira de Souza;Brandao, Paulo;Santana-Clavijo, Nelson Fernando
    • Journal of Veterinary Science
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    • v.23 no.1
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    • pp.14.1-14.11
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    • 2022
  • Background: Carnivore protoparvovirus 1, also known as canine parvovirus type 2 (CPV-2), is the main pathogen in hemorrhagic gastroenteritis in dogs, with a high mortality rate. Three subtypes (a, b, c) have been described based on VP2 residue 426, where 2a, 2b, and 2c have asparagine, aspartic acid, and glutamic acid, respectively. Objectives: This study examined the presence of CPV-2 variants in the fecal samples of dogs diagnosed with canine parvovirus in Bogotá. Methods: Fecal samples were collected from 54 puppies and young dogs (< 1 year) that tested positive for the CPV through rapid antigen test detection between 2014-2018. Molecular screening was developed for VP1 because primers 555 for VP2 do not amplify, it was necessary to design a primer set for VP2 amplification of 982 nt. All samples that were amplified were sequenced by Sanger. Phylogenetics and structural analysis was carried out, focusing on residue 426. Results: As a result 47 out of 54 samples tested positive for VP1 screening, and 34/47 samples tested positive for VP2 980 primers as subtype 2a (n = 30) or 2b (n = 4); subtype 2c was not detected. All VP2 sequences had the amino acid, T, at 440, and most Colombian sequences showed an S514A substitution, which in the structural modeling is located in an antigenic region, together with the 426 residue. Conclusions: The 2c variant was not detected, and these findings suggest that Colombian strains of CPV-2 might be under an antigenic drift.

Association of SNPs from iNOS and TLR-4 Genes with Economic Trait in Chicken (닭의 iNOS와 TLR-4 유전자 내 변이와 경제 형질 간의 연관성 분석)

  • Lim, Hee Kyong;Han, Jung-Min;Oh, Jae Don;Lee, Hak Kyo;Jeon, Gwang Joo;Lee, Jun Heon;Seo, Dong Won;Cahyadi, Muhammad;Song, Ki Duk;Choi, Kang Duk;Kong, Hong Sik
    • Korean Journal of Poultry Science
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    • v.40 no.2
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    • pp.83-89
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    • 2013
  • iNOS (Inducible nitric oxide synthase) and TLR-4 (Toll-like Receptor-4) play crucial roles in innate immunity of poultry. iNOS has been mapped to chicken chromosome 14 and implicated in a variety of chicken diseases. iNOS possesses potent antimicrobial activity, including the inhibition of microbes replication in vitro. TLR-4 is a pathogen associated molecular-pattern receptor for bacterial product, such as LPS (lipopolysaccharides) found in Gram negative bacteria, that triggers pro-inflammatory cytokine expression after engagement with ligands. In the previous studies, genetic analysis of iNOS and TLR-4 revealed the possible association of mutation in these genes with the intestinal microflora of cecum when infected with Salmonella spp. This study was aimed to augment previous findings, which show the association of iNOS (C14513T) and TLR-4 (G4409T) polymorphisms with economic traits in Korean Native Black (KNB), Rhode Island Red (RIR) and Cornish chickens. Investigation in the effect of SNPs on economic traits (layday, layw, layno, bw150, bw270, layw270) was conducted. iNOS (C14513T) had a significant effect on the average body weight at 270 days of age (p<0.05) in both KNB and RIR, whereas TLR-4 (G4409T) showed no significant correlation with all traits (p>0.05). The results obtained from using the candidate genes can be useful for the genetic improvement of body weight in both KNB and RIR breeds.