Development of a Lateral Flow Strip-Based Recombinase Polymerase Amplification Assay for the Detection of Haemonchus contortus in Goat Feces

Haemonchosis remains a significant problem in small ruminants. In this study, the assay of recombinase polymerase amplification (RPA) combined with the lateral flow strip (LFS-RPA) was established for the rapid detection of Haemonchus contortus in goat feces. The assay used primers and a probe targeting a specific sequence in the ITS-2 gene. We compared the performance of the LFS-RPA assay to a PCR assay. The LFS-RPA had a detection limit of 10 fg DNA, which was 10 times less compared to the lowest detection limit obtained by PCR. Out of 24 goat fecal samples, LFS-RPA assay detected H. contortus DNA with 95.8% sensitivity, compared to PCR, 79.1% sensitivity. LFS-RPA assay did not detect DNA from other related helminth species and demonstrated an adequate tolerance to inhibitors present in the goat feces. Taken together, our results suggest that LFS-RPA assay had a high diagnostic accuracy for the rapid detection of H. contortus and merits further evaluation.

Development of a Lateral Flow Strip-Based Recombinase Polymerase Amplification Assay for the Detection of Haemonchus contortus in Goat Feces

Haemonchosis remains a significant problem in small ruminants. In this study, the assay of recombinase polymerase amplification (RPA) combined with the lateral flow strip (LFS-RPA) was established for the rapid detection of Haemonchus contortus in goat feces. The assay used primers and a probe targeting a specific sequence in the ITS-2 gene. We compared the performance of the LFS-RPA assay to a PCR assay. The LFS-RPA had a detection limit of 10 fg DNA, which was 10 times less compared to the lowest detection limit obtained by PCR. Out of 24 goat fecal samples, LFS-RPA assay detected H. contortus DNA with 95.8% sensitivity, compared to PCR, 79.1% sensitivity. LFS-RPA assay did not detect DNA from other related helminth species and demonstrated an adequate tolerance to inhibitors present in the goat feces. Taken together, our results suggest that LFS-RPA assay had a high diagnostic accuracy for the rapid detection of H. contortus and merits further evaluation.

Oxidative stress and immune-suppression in Toxoplasma gondii positive blood donors: implications for safe blood transfusion

The sero-markers of Toxoplasma gondii and oxidative stress [OS] were determined in a group of 260 blood donors attending blood banks in Greater Cairo. Twenty-four blood donors with the highest anti-T. gondii IgG titre were tested for IgG avidity. Of whom 4 [16.6%] had low IgG avidity antibodies, documenting recent infection, 6 [25%] had borderline avidity and 14 [58.3%] showed high avidity, ruling out recent infection. The plasma level of malondialdehyde [MDA] was significantly higher and activity of glutathione peroxidase [GSH-Px] and level of tocopherol [alpha, gamma, and lambda] fractions [P < 0.001] were lower in T. gondii-seropositive than in seronegative blood donors. This significant alteration in redox status between seropositive and seronegative donors suggested a degradation of their antioxidant enzymes caused by OS induced by increased free radicals attributable to toxoplasmosis infection. T. gondii infection also had a prominent influence on the association between OS biomarkers and immune-suppression status in seropositive donors

Parasitic zoonoses at the rodent-captive primate-human health interface

Parasitic diseases at the wildlife/primate/human interface are of particular importance in zoological gardens. Better understanding of the types of wildlife parasites that do persist in zoological gardens, and drives that lead to increases in prevalence or impacts, can point to new strategies for limiting the risk of human and captive primates' exposure in zoo centres. Also, it improves our understanding of the underlying mechanisms that influence the emergence of parasitic diseases. As wild animals and humans come into greater contact with each other, the risk posed by multi-host parasites for humans, captive primates, and wildlife populations increases. Despite strong public awareness of the fact that wildlife constitutes a large and often unknown reservoir of most emerging infectious diseases, animal-human interaction has not been addressed. Herein, the potential for cross-species parasite transmission between the wild rodents, captive primates and humans is considered using the current literature and medical records. Additionally, some aspects of the interface among wildlife, captive primates and humans and its impacts on human health are discussed. Finally, priorities for future research are identified, including identifying those parasites for which multi-host interaction is likely to have the greatest impact

Diagnostic criteria for house dust mites sensitized allergic patients

House dust mites [HDM] contain a large number of components that react with IgE in individuals with allergies and induced sensi-tization and allergic diseases. The work aimed to correlate between clinical manifestations of HDM allergic patients and skin prick test [SPT] grading, and to clarify some markers denoting allergic disorders caused by HDM exposure. Thirty allergic patients with positive SPT reaction to HDM were selected, grading of disease severity according to SPT and clinical presentations. The results revealed bronchial asthma [40%], atopic dermatitis [26.7%], rhinitis 20%] and conjunctivitis [13.3%]. Serum ALISA-IgE showed mean level of 398.42 +/- 84.73, 369.87 +/- 86, 332.16 +/- 65.57 and 300.25 +/- 79.39 IU/ml respectively, with highly statistically significant difference between cases and controls [p

Host-induced phenotypic differences in Egyptian Heterophyes [digenea: heterophyidae]

A comparative morphometric study identified host-related variations in Heterophyes heterophyes. In one study, variations in adult H. heterophyes obtained from different definitive hosts were examined. Significant differences were in size and dimensions of body organs of adults collected from dogs, cats and albino-rats experimentally infected with encysted metacercariae [EMC] from mullet [Mugil cephalus]. Hypotheses on the sources of host-dependent variations were interpreted in terms of adaptation to conditions created by the host. In a second study, comparative morphometric analysis of adults recovered from puppies experimentally fed on EMC isolated from five sympatric fish species was done. No significant differences were in adults H. heterophyes recovered from puppies feed on EMC of different fishes. Constancy in morphological characters of adults reared in the same host, independent of a change of fish was seen. So, the variations depend upon host species where worms develop, and host selection may determine the worm morphology and phenotypic plasticity