Clostridium perfringenstoxin types from wild-caught Atlantic cod (Gadus morhuaL.), determined by PCR and ELISA

2002 ◽  
Vol 48 (4) ◽  
pp. 365-368 ◽  
Author(s):  
A Aschfalk ◽  
W Müller

Ninety-five fecal samples from Atlantic cod (Gadus morhua L.), caught along the northern Norwegian coast, were examined bacteriologically for occurrence of C. perfringens. Isolates were examined by polymerase chain reaction (PCR) for genes encoding the four lethal toxins (α, β, ε, and ι) for classification into toxin types and for genes encoding enterotoxin and the novel β2 toxin for further subclassification. In addition, a commercial enzyme-linked immunosorbent assay (ELISA) kit for detection of C. perfringens α, β, and ε toxin was used. Clostridium perfringens could be isolated in 37 fecal samples (38.9%) from cod. All isolates were C. perfringens toxin type A (α toxin positive) as determined by PCR and also ELISA. In addition, in isolates from two cod (2.1%) the gene encoding for β2 toxin was found (A, β2) by PCR. Genes encoding for β, ε, and ι toxins and enterotoxin were not found. This is the first detection of C. perfringens alpha and β2 toxin in cod and of β2 toxin in fish in general. The origin of this bacterium in cod is discussed.Key words: Clostridium perfringens, cod, Gadus morhua L.

1991 ◽  
Vol 48 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Steven M. Carr ◽  
H. Dawn Marshall

We determined the DNA sequence of a portion of the mitochondrial cytochrome b gene for 55 Atlantic cod (Gadus morhua) from Norway and from 10 locations within the Northern Cod complex and adjacent stocks off Newfoundland. DNA was prepared for sequencing by the polymerase chain reaction (PCR). Eleven variable nucleotide positions within a 298 base region defined 12 genotypes. Genotype proportions differed significantly between Newfoundland and Norwegian populations: the majority genotype among Newfoundland populations was present in a minority of Norwegian cod. Newfoundland cod showed less genotypic diversity than those from the eastern Atlantic: nine genotypes were found among all 10 Newfoundland populations, as compared with seven genotypes within the single Norwegian population. An exception was an overwintering, inshore Newfoundland population that showed four genotypes among five fish. As in other vertebrates, third position synonymous transitions predominate over other types of nucleotide changes. However, two amino acid replacement substitutions occur among cod, and the ratio of purine transitions to pyrimidine transitions is significantly higher than in other species. The existence of DNA sequence polymorphism permits the various hypotheses of the distribution and differentiation of Newfoundland cod stocks to be tested, and points to the utility of PCR technology in fishery genetics.


2005 ◽  
Vol 17 (2) ◽  
pp. 186-189 ◽  
Author(s):  
Grazia Greco ◽  
Anna Madio ◽  
Vito Martella ◽  
Marco Campolo ◽  
Marialaura Corrente ◽  
...  

Beta2 (β2) toxin–producing Clostridium perfringens type A strains were found to be associated with necrotic and hemorrhagic intestinal lesions in 2 Asiatic black bears ( Selenarctos thibetanus) that died suddenly. Ten isolates were obtained from the liver, lungs, heart, and small and large intestine of the animals and were examined by multiplex polymerase chain reaction for the genes encoding the 4 lethal toxins (alpha, beta, epsilon, and iota) for classification into toxin types as well as for the genes encoding enterotoxin and the novel β2-toxin for subclassification. In addition, the cpb2 sequence of the 10 isolates was different from the published sequence of cpb2 of pig type C isolate CWC245, whereas it was highly similar to the cpb2 sequence of the C. perfringens type A strain 13. This finding suggests the existence of 2 cpb2 subtypes. This is the first report of enterotoxemia associated with the presence of C. perfringens producing β2-toxin in the tissues and intestinal content of Asiatic black bears.


2012 ◽  
Vol 48 (No. 6) ◽  
pp. 163-168 ◽  
Author(s):  
K. Sakulwira ◽  
P. Vanapongtipagorn ◽  
A. Theamboonlers ◽  
K. Oraveerakul ◽  
Y. Poovorawan

Canine coronavirus (CCV) and canine parvovirus type 2 (CPV-2) are the causative agents of gastroenteritis in dogs. Seventy fecal samples from dogs with signs of gastroenteritis (vomiting and diarrhea), twenty-five fecal samples from healthy dogs and one CPV-2 vaccine strain were amplified by semi-nested polymerase chain reaction (PCR) and semi-nested reverse transcriptase polymerase chain reaction (RT-PCR), aimed at specifically studying the gene encoding the most abundant capsid protein VP2 of CPV-2 and spike protein of CCV. The specificity of the CCV RT-PCR product was evaluated by sequencing. Positive specimens comprised 44 samples (62.8%) and 9 samples (12.8%) for CPV-2 and CCV, respectively. In nine CCV positive samples, seven displayed co-infection between CCV and CPV-2. Our CCV sequence (AF482001) showed a 94.9% nucleotide identity to CCV reported in GenBank accession number D13096. High prevalence of CCV and CPV-2 infections was found in 1–2 month- and 3–6 month-old dogs, respectively. Molecular biology of these viruses is important primarily for epidemic control and preventive measures.


Genetics ◽  
1993 ◽  
Vol 133 (4) ◽  
pp. 999-1007
Author(s):  
R G Gregerson ◽  
L Cameron ◽  
M McLean ◽  
P Dennis ◽  
J Strommer

Abstract In most higher plants the genes encoding alcohol dehydrogenase comprise a small gene family, usually with two members. The Adh1 gene of Petunia has been cloned and analyzed, but a second identifiable gene was not recovered from any of three genomic libraries. We have therefore employed the polymerase chain reaction to obtain the major portion of a second Adh gene. From sequence, mapping and northern data we conclude this gene encodes ADH2, the major anaerobically inducible Adh gene of Petunia. The availability of both Adh1 and Adh2 from Petunia has permitted us to compare their structures and patterns of expression to those of the well-studied Adh genes of maize, of which one is highly expressed developmentally, while both are induced in response to hypoxia. Despite their evolutionary distance, evidenced by deduced amino acid sequence as well as taxonomic classification, the pairs of genes are regulated in strikingly similar ways in maize and Petunia. Our findings suggest a significant biological basis for the regulatory strategy employed by these distant species for differential expression of multiple Adh genes.


Open Medicine ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 749-753
Author(s):  
Wenyuan Li ◽  
Beibei Huang ◽  
Qiang Shen ◽  
Shouwei Jiang ◽  
Kun Jin ◽  
...  

Abstract In recent months, the novel coronavirus disease 2019 (COVID-19) pandemic has become a major public health crisis with takeover more than 1 million lives worldwide. The long-lasting existence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has not yet been reported. Herein, we report a case of SARS-CoV-2 infection with intermittent viral polymerase chain reaction (PCR)-positive for >4 months after clinical rehabilitation. A 35-year-old male was diagnosed with COVID-19 pneumonia with fever but without other specific symptoms. The treatment with lopinavir-ritonavir, oxygen inhalation, and other symptomatic supportive treatment facilitated recovery, and the patient was discharged. However, his viral PCR test was continually positive in oropharyngeal swabs for >4 months after that. At the end of June 2020, he was still under quarantine and observation. The contribution of current antivirus therapy might be limited. The prognosis of COVID-19 patients might be irrelevant to the virus status. Thus, further investigation to evaluate the contagiousness of convalescent patients and the mechanism underlying the persistent existence of SARS-CoV-2 after recovery is essential. A new strategy of disease control, especially extending the follow-up period for recovered COVID-19 patients, is necessary to adapt to the current situation of pandemic.


Intervirology ◽  
2021 ◽  
pp. 1-6
Author(s):  
Salman Khan ◽  
Syed Asad Ali Shah ◽  
Syed Muhammad Jamal

<b><i>Background:</i></b> Foot-and-mouth disease (FMD) is an infectious and highly contagious disease of cloven-hoofed domestic and wild animals, causing heavy economic losses to the livestock industry. Rapid and reliable diagnosis of the disease is essential for the implementation of effective control measures. This study compared sandwich enzyme-linked immunosorbent assay (S-ELISA) and conventional reverse transcription polymerase chain reaction (RT-PCR) for the diagnosis of FMD. <b><i>Methods:</i></b> A total of 60 epithelial samples from suspected cases of FMD were tested using both S-ELISA and RT-PCR assays. The level of agreement between the assays was assessed by calculating the Kappa value. <b><i>Results:</i></b> S-ELISA detected 38 (63%) samples positive for FMD virus (FMDV). Being predominant, serotype O was detected in 22 (57.9%) of the total samples tested positive, whereas 9 (23.7%) and 7 (18.4%) samples were found positive for serotypes A and Asia-1, respectively. RT-PCR detected viral genome in 51 (85%) of the samples using pan-FMDV primers set, 1F/1R. Thirty-six samples were found positive and 7 negative by both the tests. The level of agreement between the tests was assessed by calculating the Kappa value, which was found to be fair (Kappa value = 0.303 and 95% CI = 0.089; 0.517) and significant (<i>p</i> = 0.009). However, 2 samples, which were found positive on S-ELISA tested negative on RT-PCR. This may be attributed to the presence of nucleotide mismatch(es) in the primer-binding sites that may have resulted in failure of amplification of the viral genome. The serotype-specific RT-PCR assays not only confirmed serotyping results of S-ELISA but were also able to establish serotype in 9 S-ELISA-negative but pan-FMDV RT-PCR-positive samples. <b><i>Conclusions:</i></b> The RT-PCR assay contributes significantly to establishing a quick, sensitive, and definitive diagnosis of FMD in resource-constrained countries. Samples giving negative results in S-ELISA should be tested in RT-PCR for the disease detection and virus typing.


2017 ◽  
Vol 26 (3) ◽  
pp. 292-298 ◽  
Author(s):  
Cesar Augusto Barbosa de Macedo ◽  
Madlaine Frigo Silveira Barbosa de Macedo ◽  
Ana Carolina Miura ◽  
Alessandra Taroda ◽  
Sergio Tosi Cardim ◽  
...  

Abstract The aim of the present study was to investigate the occurrence of N. caninum associated with abortions of dairy cattle from Santa Catarina state, southern Brazil by using enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), and polymerase chain reaction (PCR). Blood from dairy cows that aborted along with intrathoracic fluid and tissue samples (brain, heart, liver, and lung) from their fetuses were collected and used for serology; PCR, histopathological, and immunohistochemistry (IHC) evaluations were also conducted. Twenty-one cows (51.2%) out of 41, and eight fetuses (26.7%) out of 30 were ELISA (HerdCheck, IDEXX) positive for N. caninum. Dams > 36 months of age had a higher risk of being serum positive than younger animals. PCR and IHC revealed that 38.8% (14/36) and 25.0% (9/36) of the fetuses were positive for N. caninum, respectively for each of the tests. Seropositive cows had a higher frequency of fetuses that were also positive by either intrathoracic fluid, PCR, or IHC. In summary, the present study observed a high frequency of N. caninum in abortions from dairy cows from southern Brazil, with a higher N. caninum prevalence found in cows that were older than 36 months. In addition, serology, PCR, and IHC should be used all together for better diagnosis of neosporosis in cattle.


2008 ◽  
Vol 21 (10) ◽  
pp. 1325-1336 ◽  
Author(s):  
Jorrit-Jan Krijger ◽  
Ralf Horbach ◽  
Michael Behr ◽  
Patrick Schweizer ◽  
Holger B. Deising ◽  
...  

The hemibiotroph Colletotrichum graminicola is the causal agent of stem rot and leaf anthracnose on Zea mays. Following penetration of epidermal cells, the fungus enters a short biotrophic phase, followed by a destructive necrotrophic phase of pathogenesis. During both phases, secreted fungal proteins are supposed to determine progress and success of the infection. To identify genes encoding such proteins, we constructed a yeast signal sequence trap (YSST) cDNA-library from RNA extracted from mycelium grown in vitro on corn cell walls and leaf extract. Of the 103 identified unigenes, 50 showed significant similarities to genes with a reported function, 25 sequences were similar to genes without a known function, and 28 sequences showed no similarity to entries in the databases. Macroarray hybridization and quantitative reverse-transcriptase polymerase chain reaction confirmed that most genes identified by the YSST screen are expressed in planta. Other than some genes that were constantly expressed, a larger set showed peaks of transcript abundances at specific phases of pathogenesis. Another set exhibited biphasic expression with peaks at the biotrophic and necrotrophic phase. Transcript analyses of in vitro-grown cultures revealed that several of the genes identified by the YSST screen were induced by the addition of corn leaf components, indicating that host-derived factors may have mimicked the host milieu.


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