Aelurostrongylus abstrusus Infections in Domestic Cats (Felis silvestris catus) from Antioquia, Colombia

Although Aelurostrongylus abstrusus infections in domestic cats (Felis silvestris catus) have sporadically been reported in Colombia, there is still no data available on epidemiology nor on the biology of this neglected lungworm parasite. Thus, this epidemiological study aimed to evaluate the occurrence of patent A. abstrusus infections in domestic cats from the Colombian Federal State of Antioquia. In total, 473 fecal samples of indoor/outdoor domestic cats were collected and analyzed thereafter by the Baermann funnel migration technique for the presence of A. abstrusus first stage larvae 1 (L1). The occurrence of A. abstrusus was confirmed in 0.4% (2/473) of investigated cats. Due to the presence of patent A. abstrusus infections in investigated cats, it is unfailing to include this lungworm within differential diagnoses of feline pulmonary disorders. Despite the fact that the Baermann funnel technique is currently the cheapest and the gold standard diagnostic tool for feline aelurostrongylosis, this technique is still unknown by Colombian veterinary surgeons and rarely utilized in small animal veterinary clinics. The current survey intends to generate awareness on this neglected parasitosis and to be considered as a baseline study for future surveys monitoring feline aelurostrongylosis not only in domestic/stray cats but also in endemic wild felid species of Colombia.

Screening of Strongyloides stercoralis infection in high-risk patients in Khuzestan Province, Southwestern Iran

Background Strongyloidiasis, one of the neglected tropical diseases (NTDs), can be fatal in immunocompromised patients. Available data on Strongyloides stercoralis infection in high-risk patients in Iran are limited. The aim of the present study was to determine the prevalence of S. stercoralis infection and associated risk factors among high-risk patients as well as to evaluate the sensitivity of the diagnostic tests used in the diagnose of S. stercoralis infection. Methods This cross-sectional study was performed from 2019 to 2020 among 300 high-risk patients in Khuzestan Province, southwestern Iran. Patients with autoimmune diseases, uncontrolled diabetes, HIV/AIDS, cancer, organ transplant, hematological malignancy, asthma and chronic obstructive pulmonary disease (COPD) were examined using direct smear examination, formalin-ether concentration, Baermann funnel technique, agar plate culture, and ELISA test. Since agar plate culture was considered the reference diagnostic test, culture-positive samples were confirmed by PCR amplification and the sequencing of the nuclear 18S rDNA (SSU) hypervariable region (HVRIV) of the parasite. Results The prevalence of S. stercoralis infection was 1%, 1.3%, 2%, 2.7%, and 8.7% using direct smear examination, formalin-ether concentration, Baermann funnel technique, agar plate culture, and ELISA test, respectively. All culture-positive samples were confirmed by SSU-PCR. According to the results, the most sensitive test was ELISA, with 100% sensitivity, followed by the Baermann funnel technique with the sensitivity of 75%. Direct smear examination, formalin-ether concentration technique, and Baermann funnel technique had the highest PPV (100%) while the ELISA test had the highest NPV (100%). Significant eosinophilia was observed in the patients whose culture test was positive (7/8; P < 0.05). In the present study, the majority of the positive cases by the agar plate culture had a history of prolonged exposure to soil and of asthma and COPD and were > 60 years old. Conclusions Given that the ELISA test had the highest NPV, the screening of all high-risk patients for S. stercoralis infection in endemic areas is recommended prior to starting corticosteroid therapy with the ELISA test. The results indicate the importance of paying attention to patients with unknown eosinophilia in endemic areas. Ivermectin should be available to strongyloidiasis patients in the endemic areas.

Screening of Strongyloides stercoralis Infection in High-Risk Patients in Khuzestan Province, Southwestern Iran

Background: Strongyloidiasis, one of the neglected tropical diseases (NTDs), can be fatal in immunocompromised patients. Available data on Strongyloides stercoralis infection in high-risk patients in Iran; however, is limited. The aim of the present study was to determine the prevalence of S. stercoralis infection and associated risk factors among high-risk patients, as well as to evaluate the accuracy of the diagnostic tests used in the diagnose of S. stercoralis infection. Methods: This cross-sectional study was performed during 2019 to 2020 among 300 high-risk patients in Khuzestan Province, southwestern Iran. Patients with autoimmune diseases, uncontrolled diabetes, HIV/AIDS, cancer, organ transplant, hematologic malignancy, asthma and chronic obstructive pulmonary disease (COPD) were examined using direct smear examination, formalin-ether concentration, Baermann funnel technique, agar plate culture, and ELISA test. Culture-positive samples were confirmed by PCR amplification and sequencing of the nuclear 18S rDNA (SSU) hypervariable region (HVRIV) of the parasite.Results: The prevalence of S. stercoralis infection was 1%, 1.3%, 2%, 2.7%, and 8.7% using direct smear examination, formalin-ether concentration, Baermann funnel technique, agar plate culture, and ELISA test, respectively. All culture-positive samples were confirmed by SSU-PCR. According to the results, the most sensitive test was ELISA, with 100% sensitivity, followed by Baermann funnel technique with sensitivity of 75%. Direct smear examination, formalin-ether concentration technique, and Baermann funnel technique had the highest PPV (100%), while ELISA test had the highest NPV (100%). Eosinophilia significantly was observed in patients whose culture test were positive (7/8; p= 0.001). Of these, 5 patients had a history of asthma and COPD. In the present study, the majority of the positive cases by the agar plate culture had a history of prolonged exposure to soil, history of asthma and COPD, and were over the ages of 60. In two cases, S. stercoralis larva was observed 6 months and 8 months after treatment with albendazole.Conclusions: Given that the ELISA test had the highest NPV, screening of all high-risk patients for S. stercoralis infection in endemic areas is recommended prior to starting corticosteroid therapy with ELISA test. Ivermectin should be available to the strongyloidiasis patients in the endemic areas.

Testing soil nematode extraction efficiency using different variations of the Baermann funnel method

Nematodes are increasingly used as powerful bioindicators of soil food web composition and functioning in ecological studies. Todays’ ecological research aims to investigate not only local relationships but global patterns, which requires consistent methodology across locales. Thus, a common and easy extraction protocol of soil nematodes is needed. In this study, we present a detailed protocol of the Baermann funnel method and highlight how different soil pre-treatments and equipment (soil type, amount of soil, sieving, filter type) can affect extraction efficiency and community composition by using natural nematode communities. We found that highest nematode extraction efficiency was achieved using lowest soil weight (25 g instead of 50 g or 100 g) in combination with soil sieving, and by using milk filters (instead of paper towels). PCA at the family level revealed that different pre-treatments significantly affected nematode community composition. Increasing the amount of soil increased the proportion of larger-sized nematodes being able to overcome long distances. Sieving is suggested to break up soil aggregates and, therefore, facilitate moving in general. Interestingly, sieving did not negatively affect larger nematodes that are supposed to have a higher probability of getting bruised during sieving. The present study shows that variations in the extraction protocol can alter the total density and community composition of extracted nematodes and provides recommendations for an efficient and standardized approach in future studies. Having a simple, cheap, and standardized extraction protocol can facilitate the assessment of soil biodiversity in global contexts.

Use of a cold-active entomopathogenic nematode Steinernema kraussei to control overwintering larvae of the black vine weevil Otiorhynchus sulcatus (Coleoptera: Curculionidae) in outdoor strawberry plants

The susceptibility of overwintering black vine weevil larvae Otiorhynchus sulcatus to a cold-active entomopathogenic nematode, Steinernema kraussei (isolate L137) and a commercial proprietary biopesticide, Steinernema carpocapsae (Exhibit) was assessed on outdoor potted strawberry plants. Nematodes were applied at a range of doses in early winter at a field site located in Warwickshire, England. Three months later, infestation and mortality of vine weevils were assessed. There was a clear dose response observed for S. kraussei applications. Up to 81% of vine weevil control was recorded by this nematode at the highest dose of 60 000 nematodes per pot, whereas treatments with S. carpocapsae caused no significant mortality at the dose rates used. Dissection of vine weevil larvae showed infective juveniles had developed to adults within the host. Recovery of nematodes at the end of the experiment indicated that S. kraussei (L137) was able to survive winter field conditions including prolonged exposure to low temperatures (averaging 2.7°C during the experiment) in contrast to S. carpocapsae which showed poor survival. Of the two extraction methods used, the Baermann funnel technique was found to be more efficient than Galleria mellonella baiting, with up to 44% of the original highest dose of S. kraussei nematodes being recovered by Baermann funnel compared to 8% with G. mellonella at 18°C. These results suggest S. kraussei (L137) has potential as a commercial biocontrol agent against O. sulcatus at low temperatures.