Bacterial pathogen detection by conventional culture‐based and recent alternative (polymerase chain reaction, isothermal amplification, enzyme linked immunosorbent assay, bacteriophage amplification, and gold nanoparticle aggregation) methods in food samples: A review

2020 ◽  
Author(s):  
Sang‐Oh Kim ◽  
Sang‐Soon Kim
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.


2011 ◽  
Vol 12 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Nazar M Abdalla

Objective: This study aimed to identify cases of leishmaniasis in the Nuba Mountain area, which is situated in a unique geographical site located in the centre of Sudanese leishmania belt. Wide range of investigations are available for detection of leishmania cases, but still the most reliable and easy test used as screening and epidemiological tool in field studies needs to be evaluated. The most commonly used conventional diagnostic methods direct microscopy and culture have some drawbacks in diagnosing subclinical cases of leishmaniasis. Materials and methods: In this study, comparative properties of various immune-diagnostic tools with Polymerase Chain Reaction used in sub-clinical leishmaniasis isolates were explored. The immune-diagnostic tools involved in this study include- Leishmanin Skin Test (LST), Enzyme Linked Immunosorbent Assay (ELISA) and Direct Agglutination Test (DAT). The study was conducted in the Green Valley village (Rashad Province, South Kordofan State) with a population of 332. Most of the villagers presented with sub-clinical form of leishmaniasis with minor symptoms and signs without the features found in clinical form of visceral leishmaniasis such as fever, diarrhoea, epistaxis, enlarged lymph nodes, spleen and liver. In this study we collected demographic, clinical and epidemiological data using special questionnaire. Leishmanin skin test (LST), ELISA, DAT and PCR for parasite DNA detection were used. Result: The final positive cases detected by PCR were 32 out of 332 belong to L. donovani species. The final positive cases detected by LST were 51.2% of the total population under study, while 11 out of the 37 tested samples were positive by ELISA. All of the 332 villagers showed negative readings by DAT with exception of three individuals who were positive with very high titers. Conclusion: DNA etxtraction and amplification with primers can be a good screening tool in subclinical leishmaniasis isolates. Keyword: Sub-clinical; Leishmaniasis; Leishmanin Skin Test; ELISA; DAT; PCR. DOI: 10.3329/jom.v12i1.5422J Medicine 2011; 12 : 34-39


2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S503-S503
Author(s):  
Courtney C Sutton ◽  
Patti J Walton ◽  
Montgomery F Williams ◽  
Tracey L Bastian ◽  
Michael Wright ◽  
...  

Blood ◽  
1988 ◽  
Vol 71 (4) ◽  
pp. 1027-1032 ◽  
Author(s):  
DB Duggan ◽  
GD Ehrlich ◽  
FP Davey ◽  
S Kwok ◽  
J Sninsky ◽  
...  

Abstract A patient with a localized HTLV-I-associated lymphoproliferative disease that was misdiagnosed as Hodgkin's disease is presented. The patient's serum was negative for HTLV-I antibodies by enzyme-linked immunosorbent assay (ELISA), Western blot, and radioimmunoprecipitation. Tumor tissue DNA was negative for HTLV-I by Southern blotting but was positive for distinct HTLV-I sequences when subjected to DNA amplification using the polymerase chain reaction. We conclude that the clinical and pathologic diagnosis of HTLV-I-related lymphoma can be difficult and can be confused with Hodgkin's disease. Extremely sensitive molecular biological techniques may be required to establish a diagnosis of HTLV-I-induced lymphoma.


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