scholarly journals The 1B vaccine strain of Chlamydia abortus produces placental pathology indistinguishable from a wild type infection

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242526
Author(s):  
Sergio Gaston Caspe ◽  
Morag Livingstone ◽  
David Frew ◽  
Kevin Aitchison ◽  
Sean Ranjan Wattegedera ◽  
...  

Chlamydia abortus is one of the most commonly diagnosed causes of infectious abortion in small ruminants worldwide. Control of the disease (Enzootic Abortion of Ewes or EAE) is achieved using the commercial live, attenuated C. abortus 1B vaccine strain, which can be distinguished from virulent wild-type (wt) strains by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Published studies applying this typing method and whole-genome sequence analyses to cases of EAE in vaccinated and non-vaccinated animals have provided strong evidence that the 1B strain is not attenuated and can infect the placenta causing disease in some ewes. Therefore, the objective of this study was to characterise the lesions found in the placentas of ewes vaccinated with the 1B strain and to compare these to those resulting from a wt infection. A C. abortus-free flock of multiparous adult ewes was vaccinated twice, over three breeding seasons, each before mating, with the commercial C. abortus 1B vaccine strain (Cevac® Chlamydia, Ceva Animal Health Ltd.). In the second lambing season following vaccination, placentas (n = 117) were collected at parturition and analysed by C. abortus-specific real-time quantitative PCR (qPCR). Two placentas, from a single ewe, which gave birth to live twin lambs, were found to be positive by qPCR and viable organisms were recovered and identified as vaccine type (vt) by PCR-RFLP, with no evidence of any wt strain being present. All cotyledons from the vt-infected placentas were analysed by histopathology and immunohistochemistry and compared to those from wt-infected placentas. Both vt-infected placentas showed lesions typical of those found in a wt infection in terms of their severity, distribution, and associated intensity of antigen labelling. These results conclusively demonstrate that the 1B strain can infect the placenta, producing typical EAE placental lesions that are indistinguishable from those found in wt infected animals.

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Sergio Gaston Caspe ◽  
David Frew ◽  
Elspeth Milne ◽  
Francesca Chianini ◽  
Tom McNeilly ◽  
...  

Chlamydia abortus is the most commonly diagnosed cause of abortion in small ruminants around the world [1]. Control of chlamydial abortion is achieved in several European countries using an attenuated live 1B C. abortus vaccine strain, which can be distinguished from virulent wild-type strains by PCR-RFLP analysis [2]. Application of this method has provided molecular evidence that the 1B strain can cause abortion in ewes [3, 4]. The objective of this study was to define the distribution of lesions and bacterial load in cotyledons from ewes vaccinated with the 1B strain compared to normal wild-type infections. A Chlamydia-free flock of 75 multiparous adult ewes were vaccinated twice, two years apart, each prior to mating, with the commercial 1B vaccine. In the second lambing season following the last vaccination, placentae (n=116) were collected and analysed by C. abortus real-time qPCR [3]. Only two of the placentae, both from the same ewe, were found to be positive. Viable organisms were isolated from these placentae and confirmed by RFLP-PCR [3] to be vaccine-type. All cotyledons from these placentae were analysed by histopathology and immunohistochemistry [5], and compared with those from wild-type infected placentae. The lesions in the vaccine-type infected placentae were indistinguishable from the wild-type infected placentae in terms of their severity, load and distribution. These results suggest that the 1B vaccine strain of C. abortus can cause chlamydial abortion in ewes producing typical placental lesions to wild-type infected animals, and could be circulating with the potential to cause natural infection and disease.


Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 543
Author(s):  
Sergio Gastón Caspe ◽  
Javier Palarea-Albaladejo ◽  
Clare Underwood ◽  
Morag Livingstone ◽  
Sean Ranjan Wattegedera ◽  
...  

Chlamydia abortus infects livestock species worldwide and is the cause of enzootic abortion of ewes (EAE). In Europe, control of the disease is achieved using a live vaccine based on C. abortus 1B strain. Although the vaccine has been useful for controlling disease outbreaks, abortion events due to the vaccine have been reported. Recently, placental pathology resulting from a vaccine type strain (vt) infection has been reported and shown to be similar to that resulting from a natural wild-type (wt) infection. The aim of this study was to extend these observations by comparing the distribution and severity of the lesions, the composition of the predominating cell infiltrate, the amount of bacteria present and the role of the blood supply in infection. A novel system for grading the histological and pathological features present was developed and the resulting multi-parameter data were statistically transformed for exploration and visualisation through a tailored principal component analysis (PCA) to evaluate the difference between them. The analysis provided no evidence of meaningful differences between vt and wt strains in terms of the measured pathological parameters. The study also contributes a novel methodology for analysing the progression of infection in the placenta for other abortifacient pathogens.


2021 ◽  
Vol 70 (4) ◽  
pp. 35-42
Author(s):  
Tatyana E. Ivashchenko ◽  
Maria I. Yarmolinskaya ◽  
Saimat S. Tkhazaplizheva

BACKGROUND: Genital endometriosis is one of the most pressing problems of modern gynecology. Melatonin is a promising drug with a potentially curative effect on endometriosis. AIM: The aim of this study was to conduct a comparative analysis of the genetic polymorphism of some genes encoding enzymes involved in melatonin metabolism. MATERIALS AND METHODS: The genetic polymorphism in the NAT2 and CYP1B1 genes encoding enzymes involved in melatonin metabolism in patients with different tolerance to this drug was analyzed by PCR-RFLP analysis. RESULTS: In patients with genital endometriosis, the presence of a wild-type allele (N) of the NAT2 gene was associated with poor tolerance of melatonin. The NAT2 (N / N) rapid acetylator phenotype combined with the low catalytic activity of CYP1B1 (C / C) occurred more frequently in endometriosis patients having poor melatonin tolerability compared to the group of patients who tolerated the therapy well. CONCLUSIONS: For patients with genital endometriosis with the wild-type (N) allele of the NAT2 gene, melatonin administration is inappropriate due to numerous side effects during the drug use.


2000 ◽  
Vol 66 (11) ◽  
pp. 5087-5091 ◽  
Author(s):  
Kumiko Matsuura ◽  
Mitsuhiro Ishikura ◽  
Hiromu Yoshida ◽  
Takashi Nakayama ◽  
Sumiyo Hasegawa ◽  
...  

ABSTRACT Seventy-eight poliovirus strains isolated from river water and sewage in Toyama Prefecture, Japan, during 1993 to 1995 were characterized by the PCR-restriction fragment length polymorphism (RFLP) method and by partially sequencing the VP3 and VP1 regions of the viral genome. Of these isolates, 36 were identified as Sabin vaccine strains, and 42 were identified as vaccine variant strains that had less than 1.4% nucleotide divergence from the Sabin strains, including 7 isolates with patterns different from those of Sabin strains as determined by PCR-RFLP analysis. These findings suggest that wild-type poliovirus was not circulating in Toyama Prefecture.


2003 ◽  
Vol 49 (7) ◽  
pp. 1050-1057 ◽  
Author(s):  
Anthony A Killeen ◽  
John W Breneman ◽  
Arlene R Carillo ◽  
Jason Liu ◽  
Craig S Hixson

Abstract Background: Two mutations in HFE, G845A (amino acid substitution C282Y) and C187G (H63D), are associated with hereditary hemochromatosis. We developed and validated a novel method, linked linear amplification (LLA), for detection of these two mutations. Methods: Two segments of HFE were amplified by a multiplex LLA reaction that generated biotinylated LLA products. Aliquots of the multiplex LLA reaction were captured in microwells by hybridization to immobilized allele-specific oligonucleotides (ASOs). One wild-type and one mutant ASO represented the DNA sequence at each of the two mutation sites. Hybridization was detected by a streptavidin–horseradish peroxidase-based colorimetric method. Genotypes obtained by LLA and PCR-restriction fragment length polymorphism (PCR-RFLP) methods for 320 individuals were compared. Results: The amplified samples included the following genotypes as determined by PCR-RFLP: wild-type 282 and 63 codons (n = 105), C282Y homozygous mutant (n = 54), C282Y heterozygous (n = 52), H63D homozygous mutant (n = 17), H63D heterozygous (n = 59), and compound H63D and C282Y heterozygous mutant (n = 33). There was complete concordance between the results obtained by LLA and those obtained by PCR-RFLP analysis. The presence of another HFE mutation, A193T (encoding S65C), did not interfere with genotyping at codon 63. Conclusions: LLA provides a reliable method to detect the common mutations in HFE that cause hereditary hemochromatosis.


2021 ◽  
Vol 8 (1) ◽  
pp. 37-46
Author(s):  
A. Veretsun ◽  
B. Stegniy ◽  
O. Rula ◽  
V. Bolotin ◽  
A. Stegniy ◽  
...  

Aim. To conduct a virological, PCR, PCR-RFLP and sequencing study of infectious laryngotracheitis virus (ILTV) isolates obtained from sick and dead chickens at industrial and backyard poultry farms in the eastern region of Ukraine collected over the years 2010–2019 and to establish their pathotype and relationship with internationally occurring strains. Methods. Material for virological studies was collected in the framework of research program of the NSC IEСVM during 2010-2019 in the poultry farms in the North-Eastern region of Ukraine, where the birds with the respiratory clinical signs were found. In total, 28 poultry farms were observed. ILTV isolates were obtained with conventional methods, using 10–12-day-old chicken embryos. A 0,2 ml of 10–20 % suspension of pathological material in PBS was used for inoculation. For in-depth studies, we used 4 isolates of ILTV obtained from sick and dead chickens from industrial and backyard poultry farms in Kharkiv, Luhansk, Donetsk, and Sumy regions from 2010–2019. The identification of ILTV isolates was performed via conventional PCR. The pathotype of ILTV strains was determined using PCR-RFLP (polymerase chain reaction – restriction fragment length polymorphism) analysis. The PCR-RFLP was performed at Royal GD, the Netherlands. The (partial) sequencing of the US8 gene was performed using Sanger sequencing method. The phylogenetic analysis, using sequences of 2 Ukrainian strains (MZ323228, MZ333273) and 17 international gene sequences present in GenBank, was performed using the Maximum Likelihood method. For comparative analysis, sequences of vaccine ILT virus strains were used. Results. Over the years 2010-2019, 7 isolates of ILTV were obtained from sick and dead poultry with typical clinical signs and internal lesions at industrial and backyard farms of the Kharkiv, Donetsk, Luhansk and Sumy regions, and the Autonomous Republic of Crimea. Other avian respiratory viral and bacterial pathogens were not detected. Five isolates were obtained from poultry of industrial holdings where vaccination against ILT is carried out. Using PCR-RFLP analysis of 4 isolates, we found that three of them (Sumy 6-11/19, A 04-12, B 2-10) to belong to vaccine-type ILTV strains and only one, B 59-11strain, belongs to wild-type ILTV. Vaccine-type ILTV strains circulated and possibly still circulate in Ukraine in industrial and backyard poultry farms among both vaccinated and non- vaccinated poultry. An ILTV wild-type strain was obtained from non-vaccinated chickens from a backyard farm, which may indicate an important role of backyard farms in maintaining the circulation of the virus. After partial sequencing and phylogenetic analysis of the ILTV US8 gene the two Ukrainian strains studied were placed into two different clusters: The vaccine-type B 2-10 strain, obtained from sick vaccinated chickens from an industrial farm, was close to vaccine-type strains circulating in, China, Italy and the USA. The wild-type B 59-11strain, obtained from sick non-vaccinated backyard chickens, was located in another cluster and closest to a the wild-type B 59-11 ILTV strain from Brazil. Conclusions. In this article we describe for the first time the characterization of vaccine-type and wild-type isolates of ILTV in industrial and backyard poultry farms, proving their relevance for the poultry production in Ukraine. The results obtained show the need and prospects for further monitoring of ILTV circulation in small backyard poultry farms and in industrial poultry farms, especially following the frequent use for vaccination of live attenuated wild-type ILTV strains in Ukraine. Further molecular, phylogenetic and epidemiological characterization of the strains obtained should be performed in the near future to further precise their attributes, epidemiology and origin.


1995 ◽  
Vol 31 (5-6) ◽  
pp. 317-321 ◽  
Author(s):  
Jane Sellwood ◽  
Pamela A. Litton ◽  
Jacqueline McDermott ◽  
Jonathon P. Clewley

The WHO Poliovirus Eradication Programme has renewed interest in the identification of wild and vaccine strains of poliovirus circulating in the community. One method of monitoring these strains is to study poliovirus isolates detected in sewage. To facilitate the isolation of poliovirus from sewage and eliminate the possibility of detecting the other enteroviruses, sewage was inoculated onto a transfected Mouse L cell line. This cell line contains the gene for the poliovirus receptor which allows poliovirus infection to take place but not that of other enteroviruses. This cell line is, however, too sensitive to the toxic elements of concentrated sewage to be of practical use. Polioviruses have also been isolated from river and seawater as part of three year surveys of sewage discharges into a river system and a coastal harbour. These isolates have been characterised using PCR amplification of a region of the VP1 gene followed by restriction fragment length polymorphism (RFLP) analysis. All isolates were vaccine-like although many poliovirus type 2 isolates had distinct PCR-RFLP profiles. The RFLP typing method is an efficient system for rapidly monitoring poliovirus isolates from the environment.


BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Somayeh Kordafshari ◽  
Pollob Shil ◽  
Marc S. Marenda ◽  
Olusola M. Olaogun ◽  
Barbara Konsak-Ilievski ◽  
...  

Abstract Background Genomic comparison of Mycoplasma synoviae vaccine strain MS-H and the MS-H parental strain 86,079/7NS established a preliminary profile of genes related to attenuation of MS-H. In this study we aimed to identify the stability of mutations found in MS-H after passage in experimental or field chickens, and to evaluate if any reverse mutation may be associated with changes in characteristics of MS-H in vitro or in vivo. Results Whole genome sequence analysis of 5 selected MS-H field reisolates revealed that out of 32 mutations reported previously in MS-H, 28 remained stable, while four found to be reversible to the wild-type. Each isolate possessed mutations in one to three of the genes obg, oppF1 and gap and/or a non-coding region. Examination of the 4 reversible mutations by protein modeling predicted that only two of them (in obg and oppF1 genes) could potentially restore the function of the respective protein to that of the wild-type. Conclusions These results suggest that the majority of the MS-H mutations are stable after passage in vaccinated chickens. Characterisation of stable mutations found in MS-H could be utilised to develop rapid diagnostic techniques for differentiation of vaccine from field strains or ts- MS-H reisolates.


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