scholarly journals Isolation and molecular characterization of Campylobacter jejuni from chicken and human stool samples in Egypt

Author(s):  
Nahed Hamed GHONEIM ◽  
Khaled Abdel-Aziz ABDEL-MOEIN ◽  
Ashraf Mohamed Abdel Khalek BARAKAT ◽  
Ahmed Gaffer HEGAZI ◽  
Khaled Abd El-Hamid ABD EL-RAZIK ◽  
...  
2020 ◽  
Vol 9 (1) ◽  
pp. 54
Author(s):  
Salem Belkessa ◽  
Daniel Thomas-Lopez ◽  
Karim Houali ◽  
Farida Ghalmi ◽  
Christen Rune Stensvold

The molecular epidemiology of giardiasis in Africa remains unclear. A study was carried out across four hospitals in Algeria. A total of 119 fecal samples from 55 children, 37 adults, and 27 individuals of undetermined age, all scored positive for intestinal parasites by microscopy, and were screened by real-time PCR for Giardia. Molecular characterization of Giardia was performed by assemblage-specific PCR and PCR targeting the triose phosphate isomerase gene (tpi). Of the 119 samples, 80 (67%) were Giardia-positive by real-time PCR. For 48 moderately-highly real-time PCR-positive samples, tpi genotyping assigned 22 samples to Assemblage A and 26 to Assemblage B. Contrary to Assemblage A, Assemblage B exhibited substantial genetic diversity and allelic heterozygosity. Assemblage-specific PCR proved to be specific for discriminating Assemblage A or B but not as sensitive as tpi genotyping. We confirmed that real-time PCR is more sensitive than microscopy for detecting Giardia in stool samples and that robust amplification and sequencing of the tpi gene is feasible when moderate-to-strongly real-time PCR-positive samples are used. This study is one of the few performed in Africa providing genotyping data on Giardia infections in humans. Both assemblages A and B were commonly seen and not associated with specific sociodemographic data.


F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 662
Author(s):  
Tarig A. Gamar ◽  
Hassan H. Musa ◽  
Hisham N. Altayb ◽  
Mohamed H. Mohamed ◽  
Adam D. Abakar

Background: Hookworms infect the intestines, cause an itchy rash, respiratory and gastrointestinal problems, and eventually iron deficiency (anaemia) due to the ongoing loss of blood. The objectives of this study were to assess the prevalence and molecular characterization of hookworms isolated from food handlers attending the Public Health Laboratories in Khartoum state, Sudan, for annual check-ups, and to assess the efficiency of PCR as molecular probe for hookworm infection. Methods: A total of 350 foods handlers’ participant's stool samples who were not suspected to be infected with hookworms were studied. Conventional methods were applied to make an early diagnosis. Stool samples were collected from public health laboratories (the public health lab in the Medical Commission) of Khartoum State; Omdurman locality, Khartoum North locality and Khartoum locality between October 2016 and April 2017. Specific identification was made by PCR on specimens identified as positive by Baermann’s technique, which were then sequence and genotyped Results: The prevalence of hookworms in the stool samples of food-handlers was 1.43%. One larval specimen recovered by Baermann’s technique was confirmed to be Necator americanus by PCR. PCR also confirmed that Necator americanus was the common species isolated from four further specimens. The results of DNA sequencing for Necator americanus were deposited in NCBI GenBank under the following accession numbers: sample 91, MH035824; sample 92, MH035825; sample 294, MH035826; and sample 319 MH035827. Conclusion: PCR was found to be effective for confirmation of the diagnosis of hookworm infection and can aid the clinician in initiating prompt and appropriate antiparasite therapy.


2020 ◽  
Vol 8 (10) ◽  
pp. 1608
Author(s):  
Constantin König ◽  
Martin Meyer ◽  
Corinna Lender ◽  
Sarah Nehls ◽  
Tina Wallaschkowski ◽  
...  

Recently, a putative alcohol dehydrogenase 3, termed EhADH3B of the Entamoeba histolytica isolate HM-1:IMSS was identified, which is expressed at higher levels in non-pathogenic than in pathogenic amoebae and whose overexpression reduces the virulence of pathogenic amoebae. In an in silico analysis performed in this study, we assigned EhADH3B to a four-member ADH3 family, with ehadh3b present as a duplicate (ehadh3ba/ehadh3bb). In long-term laboratory cultures a mutation was identified at position 496 of ehadh3ba, which codes for a stop codon, which was not the case for amoebae isolated from human stool samples. When using transfectants that overexpress or silence ehadh3bb, we found no or little effect on growth, size, erythrophagocytosis, motility, hemolytic or cysteine peptidase activity. Biochemical characterization of the recombinant EhADH3Bb revealed that this protein forms a dimer containing Ni2+ or Zn2+ as a co-factor and that the enzyme converts acetaldehyde and formaldehyde in the presence of NADPH. A catalytic activity based on alcohols as substrates was not detected. Based on the results, we postulate that EhADH3Bb can reduce free acetaldehyde released by hydrolysis from bifunctional acetaldehyde/alcohol dehydrogenase-bound thiohemiacetal and that it is involved in detoxification of toxic aldehydes produced by the host or the gut microbiota.


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