scholarly journals Detection of Campylobacter jejuni and Salmonella typhimurium in chicken using PCR for virulence factor hipO and invA genes (Saudi Arabia)

2021 ◽  
Vol 41 (9) ◽  
Author(s):  
Khaloud M. Alarjani ◽  
Manal F. Elkhadragy ◽  
Abdulrahman H. Al-Masoud ◽  
Hany M. Yehia
Keyword(s):  
Polymerase Chain Reaction ◽  
Saudi Arabia ◽  
16S Rrna ◽  
Campylobacter Jejuni ◽  
Molecular Size ◽  
Strain Atcc ◽  
Widal Test ◽  
Chain Reaction ◽  
Inva Gene ◽  
Polymerase Chain

Abstract Campylobacter jejuni and Salmonella typhimurium are the leading causes of bacterial food contamination in chicken carcasses. Contamination is particularly associated with the slaughtering process. The present study isolated C. jejuni and S. typhimurim from fifty chicken carcass samples, all of which were acquired from different companies in Riyadh, Saudi Arabia. The identification of C. jejuni was performed phenotypically by using a hippurate test and genetically using a polymerase chain reaction with primers for 16S rRNA and hippurate hydrolase (hipO gene). For the dentification of S. typhimurim, a serological Widal test was carried out using serum anti-S. typhimurium antibodies. Strains were genetically detected using invA gene primers. The positive isolates for C. jejuni showed a specific molecular size of 1448 bp for 16S rRNA and 1148 bp for hipO genes. However, the positive isolates of the invA gene exhibited a specific molecular size at 244 bp using polymerase chain reaction (PCR). Comparing sequencing was performed with respect to the invA gene and the BLAST nucleotide isolates that were identified as Salmonella enterica subsp. enterica serovar typhimurium strain ST45, thereby producing a similarity of 100%. The testing identified C.jejuni for hippuricase, GenBank: Z36940.1. While many isolates of Salmonella spp. that contained the invA gene were not necessarily identified as S. typhimurim, the limiting factor for the Widal test used antiS. typhimurum antibodies. The multidrug resistance (MDR) of C. jejuni isolates in chickens was compared with the standard C. jejuni strain ATCC 22931. Similarly, S. typhimurium isolates were compared with the standard S. typhimurium strain ATCC 14028.

scholarly journals Molecular Characterization of Salmonella Species Isolates from Some Hospitals in Jos, Nigeria

2021 ◽  
Vol 2 (2) ◽  
pp. 1-5
Author(s):  
S. B. Uneze ◽  
P. F. Chollom ◽  
Y. A. Agabi ◽  
D. J. Mawak ◽  
O. J. Egbere ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Molecular Characterization ◽  
Molecular Size ◽  
Molecular Techniques ◽  
The Other ◽  
Chain Reaction ◽  
Inva Gene ◽  
Polymerase Chain ◽  
Similarities And Differences

The conventional methods of identification of Salmonella involving microbiological enrichment and successive identification mostly are tedious, time consuming and not specific. Therefore, the aim of this study was to utilize molecular techniques to characterize Salmonella species isolates from some Hospitals in Jos, Nigeria. The 10 isolates collected from some Hospitals in Jos, Nigeria were screened for Salmonella using conventional biochemical methods. The positive isolates were identified using polymerase chain reaction (PCR) for discernment of invasion A (invA) gene at explicit molecular size (284 bp) utilizing explicit primers (forward and reverse). Sequencing of the invA gene was performed and the similarities and differences between our invA gene and published sequences on GenBank were assessed. Seven out of ten confirmed Salmonella species isolates were positive to the invA gene while the remaining three were negative. The homology level of nucleotide sequence (97.746%) demonstrated high similitude between the local isolates and the other sequences on GenBank. Molecular characterization of the Salmonella isolates provides data about the virulence of the pathogen just as its relatedness to different organisms which offer data about the genome of the organisms and are helpful for epidemiological examinations. Therefore, Molecular methods which enable the detection of virulent genes are extremely important surveillance tools that are required to assist in curbing the escalation of infections caused by Salmonella.

scholarly journals Quantification of methanogenic Archaea within Baltic Sea copepod faecal pellets

2020 ◽  
Vol 167 (10) ◽  
Author(s):  
Janine Wäge ◽  
Oliver Schmale ◽  
Matthias Labrenz
Keyword(s):  
Polymerase Chain Reaction ◽  
16S Rrna ◽  
Baltic Sea ◽  
Methanogenic Archaea ◽  
Chain Reaction ◽  
Methanogenic Activity ◽  
Faecal Pellets ◽  
Analogous Data ◽  
Polymerase Chain ◽  
Digital Polymerase Chain Reaction

Abstract Methane enrichments are frequently observed in the oxic upper water column of the central Baltic Sea during summer months. However, methane sources as well as the fate of methane produced in surface near waters still remain unclear. In the present study, we conducted ship-based grazing experiments to examine the presence of methanogenic archaea in copepod faecal pellets. We quantified bacterial and archaeal 16S rRNA and the mcrA gene and transcripts within copepod faecal pellets by using droplet digital polymerase chain reaction. We showed that the pellets (< 150-µm) harbour a small number of methanogenic archaea; however, mcrA transcripts indicating methanogenic activity were not detected. This suggests that copepod faecal pellets from the central Baltic Sea, similar to analogous data on copepod guts, harbour the potential but are an unlikely hotspot for methane production by methanogenic archaea.

scholarly journals 1834. Incremental Diagnostic Value of 16S Ribosomal RNA Gene Polymerase Chain Reaction/Sanger Sequencing in Clinical Practice

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S44-S44
Author(s):  
Sarwat Khalil ◽  
Madiha Fida ◽  
Douglas W Challener ◽  
Omar Abu Saleh ◽  
Muhammad R Sohail ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Clinical Practice ◽  
16S Rrna ◽  
Ribosomal Rna ◽  
Mayo Clinic ◽  
Sanger Sequencing ◽  
Diagnostic Value ◽  
Chain Reaction ◽  
Material Support ◽  
Polymerase Chain

Abstract Background Polymerase chain reaction (PCR)/sequencing targeting the 16S ribosomal RNA (rRNA) gene to detect bacteria in normally sterile tissues and fluids has become increasingly popular in clinical medicine. This culture-independent technique can detect bacteria that are nonviable or difficult to cultivate using conventional methods. The clinical value of this type of testing is not well defined. We aimed to assess the diagnostic value of 16S rRNA PCR/Sanger sequencing as a clinical diagnostic assay at Mayo Clinic. Methods This is an interim analysis of the first 173 of 478 patients who had 16S rRNA PCR/Sanger sequencing done on sterile tissues or fluids at our institution from April, 2017 to November, 2018 as part of routine clinical practice. Medical records are being retrospectively reviewed, with results compared with those of culture. Results We reviewed 207 specimens from 173 patients (musculoskeletal 79%, cardiovascular 7%, central nervous system 4%, other 9%) that underwent 16S rRNA PCR/Sanger sequencing by clinical request (Table 1). In 90% of these specimens, the test was pre-planned rather than added-on. Nine specimens were excluded from analysis, as cultures were not performed. Overall concordance of culture with PCR/sequencing was 81% (160/197; P < 0.0001). Of 44 culture-positive specimens, PCR detected the same bacterium in 21 (48%) (Table 2). 45% (20/44) of those with positive cultures and 46% of those with positive PCR/sequencing results had received prior antimicrobial therapy (Table 3). PCR was negative in 139/144 specimens that were culture-negative (97%). PCR/sequencing was helpful in detecting a putative bacterial pathogen in 4 patients with negative cultures (Table 4). Conclusion Overall, 16S rRNA PCR/Sanger sequencing improved diagnostic yield compared with culture in a minority of cases. The described assay is limited by its inability to detect polymicrobial infections, a technical limitation that could possibly be addressed using massive parallel sequencing. Careful selection of cases and a save and add-on approach may be more cost-effective than upfront testing, although this was requested in a minority of cases. Disclosures Robin Patel, MD, ASM and IDSA: Other Financial or Material Support, Travel reimbursement, editor’s stipends; CD Diagnostics, Merck, Hutchison Biofilm Medical Solutions, Accelerate Diagnostics, ContraFect, TenNor Therapeutics Limited, Shionogi: Grant/Research Support; Curetis, Specific Technologies, NextGen Diagnostics, PathoQuest, Qvella: Consultant; NBME, Up-to-Date, the Infectious Diseases Board Review Course: Honorarium recipient, Other Financial or Material Support; Patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, and a patent on an anti-biofilm substance issued: Other Financial or Material Support, Patents.

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