Detection of anthelmintic resistance in nematodes infecting dairy heifers in Puerto Rico

The efficacy of the anthelmintic albendazole (ALB), doramectin (DOR) and ivermectin (IVM) were evaluated in Holstein and Holstein crossbreed dairy heifers using the fecal egg count reduction test (FECRT). Dairy heifers (n=420; ~6 months of age; BW = 149 ± 39.6 kg) were evaluated in 21 dairy farms. All heifers were required to be on pasture and not have been exposed to anthelmintic treatment for a minimum of 3 months. At each dairy farm, a priori, groups of at least 18 heifers were randomly divided to be treated with IVM, or DOR, or ALB following manufacturer's instructions. Fecal samples were collected directly from the rectum 7 days before anthelmintic treatment (d-7), at the time of the treatment (d0), and 14 days after treatment (d14). Only heifers that had an average FEC ³ 100 eggs per gram of feces (average of FEC from day d-7 and d0) were considered in the FECRT. The FECRT was determined by the modified McMaster technique. Of the three-anthelmintic used, ALB (n=142) proved to be the most effective (P < 0.0005) with an efficacy of 67.47% ± 8.43. The efficacy of DOR and IVM did not differ (P = 0.8713). While DOR (n = 130) exhibited a efficacy of 25.50% ± 18.00, IVM (n = 148) exhibited a efficacy of -8.13% ± 19.89 due to an increase in FEC after treatment. Dairy farmers should implement integrated methods of nematode control to preserve the effectiveness of currently available anthelmintics.

The effect of helminthic invasion on the level of post-vaccination antibodies against canine distemper and parvovirus enteritis in dogs

Relevance. In the instructions for the use of vaccines for dogs, there is a clause prescribing mandatory anthelmintic treatment of the animal before vaccination. This is really a correct indication, since it is well known that helminthiasis affects the animal’s body, disrupting many metabolic processes and causing a number of pathological changes in the body. Helminthic infestations affect the level of immunity of the animal by changing the level of immunoglobulins, causing changes in the T- and B-systems of immunity. However, there is no data available in the literature describing how helminths affect the production of post-vaccination antibodies. This paper describes an experiment aimed at establishing how toxocara invasion affects the formation of post- vaccination immunity against canine distemper and parvovirus enteritis in dogs.Methods. The research was conducted in a shelter for neglected animals in Vitebsk. The object of research was two dogs aged 4 years and seven puppies aged 1–2 months. The animals were divided into two groups. The first group included one adult dog and four puppies. The second group included an adult dog and three puppies. Animals of both groups were vaccinated against carnivorous plague and parvovirus enteritis, but only animals of the second group were dewormed.Results. By evaluating the results of the study, it was found that helminthic invasion really hinders the development of post-vaccination immunity.

Changes in Serum Thiol-Disulphide Homeostasis in Sheep with Gastrointestinal Nematodes

This work aimed to evaluate the thiol-disulphide homeostasis in serum of lambs naturally infected by gastrointestinal nematodes presenting different levels of parasite load indirectly indicated by faecal worm egg counts (EPG). Furthermore, the possible changes in the thiol-disulphide dynamic after different procedures to reduce the parasitic charge, such as the integrated crop-livestock system or anthelmintic treatment, were assessed. The results were compared with a panel of various oxidative stress and inflammatory biomarkers. The lambs were divided into three groups: animals highly infected (EPG higher than 5000) and packed cell volume (PCV) lower than 24% (G1); animals highly infected (EPG higher than 5000) and normal PCV (>24%) (G2); and animals presenting EPG lower than 5000 and normal PCV (>24%) (G3). The highly infected lambs (G1 and G2) showed lower total thiol (TT) and native thiol (SH) (p ≤ 0.01) than those from G3. After treatment, TT and SH increased significantly in all groups (p ≤ 0.01), and the disulphide (SS)/TT and SS/SH ratios decreased significantly (p < 0.01) in G1 and G2. These results show that the thiol-disulphide balance was impaired in lambs infected by gastrointestinal nematodes and that it could be potentially used as a biomarker to monitor this disease.

Fascioliasis: una causa infrecuente de obstrucción de vía biliar. Reporte de un caso

Hepatic fascioliasis is a parasitic disease caused by the fluke Fasciola hepatica. In the chronic phase of the disease, the adult form of the parasite adopts the bile ducts as the ideal environment to develop, causing them to dilate and simulating an obstructive jaundice process. The case of a 48-year-old woman is presented, who was admitted for jaundice, choluria and eight loss. After the corresponding complementary studies had been carried out, an endoscopic retrograde cholangiography (ERCP) was performed and an adult Fasciola hepatica parasite was extracted from the biliary tract. Subsequently, anthelmintic treatment with triclabendazole was started, resulting in a favorable evolution and resolution of the condition.

Metagenomic Analysis of Fecal Archaea, Bacteria, Eukaryota, and Virus in Przewalski's Horses Following Anthelmintic Treatment

Intestinal microbiota is involved in immune response and metabolism of the host. The frequent use of anthelmintic compounds for parasite expulsion causes disturbance to the equine intestinal microbiota. However, most studies were on the effects of such treatment on the intestinal bacterial microbes; none is on the entire microbial community including archaea and eukaryotic and viral community in equine animals. This study is the first to explore the differences of the microbial community composition and structure in Przewalski's horses prior to and following anthelmintic treatment, and to determine the corresponding changes of their functional attributes based on metagenomic sequencing. Results showed that in archaea, the methanogen of Euryarchaeota was the dominant phylum. Under this phylum, anthelmintic treatment increased the Methanobrevibacter genus and decreased the Methanocorpusculum genus and two other dominant archaea species, Methanocorpusculum labreanum and Methanocorpusculum bavaricum. In bacteria, Firmicutes and Bacteroidetes were the dominant phyla. Anthelmintic treatment increased the genera of Clostridium and Eubacterium and decreased those of Bacteroides and Prevotella and dominant bacteria species. These altered genera were associated with immunity and digestion. In eukaryota, anthelmintic treatment also changed the genera related to digestion and substantially decreased the relative abundances of identified species. In virus, anthelmintic treatment increased the genus of unclassified_d__Viruses and decreased those of unclassified_f__Siphoviridae and unclassified_f__Myoviridae. Most of the identified viral species were classified into phage, which were more sensitive to anthelmintic treatment than other viruses. Furthermore, anthelmintic treatment was found to increase the number of pathogens related to some clinical diseases in horses. The COG and KEGG function analysis showed that the intestinal microbiota of Przewalski's horse mainly participated in the carbohydrate and amino acid metabolism. The anthelmintic treatment did not change their overall function; however, it displaced the population of the functional microbes involved in each function or pathway. These results provide a complete view on the changes caused by anthelmintic treatment in the intestinal microbiota of the Przewalski's horses.

Effect of Copper Oxide Wire Particles with and Without Anthelmintic Treatment or Anthelmintic Treatment Alone on Gastrointestinal Nematode (GIN) Fecal Egg Counts in Goats

In two experiments (Exp), naturally parasite-infected 5–8 mo-old intact male Spanish goats were used to determine fecal egg count (FEC) reduction effects of copper oxide wire particles (COWP; 1 g bolus Copasure®) and levamisole (12 mg/kg; LEV; Prohibit®) alone or in combination with COWP; for Exp 2, albendazole (20 mg/kg; ALB, Valbazen ®, Exp 2 only) alone or in combination with COWP and an untreated control group (CON; n = 11) was also included. Animals were individually housed in 1.5 x 1.5-m pens (Exp. 1) or as a group on pasture (Exp. 2). For the studies, goats were selectively dewormed based on a FAMACHA© eyelid color score of 3, 4 or 5, with n = 12 and 13 for COWP in Exp 1 and 2, respectively, n = 14/Exp for LEV, n = 12/Exp for COWP and levamisole (LC), and (Exp, 2), n = 10 for COWP and albendazole (AC) and n = 12 for ALB. Fecal samples were collected using a gloved finger technique on D 0 and 14 in Exp 1 and Day 0 and 10 for Exp 2 for determination of FEC using a modified McMaster’s technique with a 50 egg per gram sensitivity and calculation of FEC reduction (RED; ((Day 0 FEC-Day 14 FEC)/Day 0 FEC)*100). Data were analyzed with a general liner model procedure using SAS. Larval culture (Exp 1) indicated 99.8% Haemonchus contortus on Day 0. Mean RED was greater for LC than LEV and COWP (P &lt; 0.04) for Exp 1 (Day 14). For Exp 2, mean RED was greater (P &lt; 0.04) for AC than ALB and CON, but not COWP, and was greater (P &lt; 0.03) for LC compared CON and COWP, but not LEV. In these two studies, COWP resulted in &gt; 93% reduction in FEC and the addition of a deworming drug did not improve effectiveness consistently (only in Exp. 1).

Effect of hookworm infection and anthelmintic treatment on naturally acquired antibody responses against the GMZ2 malaria vaccine candidate and constituent antigens

Background Malaria and helminths diseases are co-endemic in most parts of sub-Saharan Africa. Immune responses from each of these pathogens interact, and these interactions may have implications on vaccines. The GMZ2 malaria vaccine candidate is a fusion protein of Plasmodium falciparum merozoite surface protein 3 (MSP3) and glutamate rich protein (GLURP R0). GMZ2 has recently showed modest efficacy in a phase IIb multicenter trial. Here, we assessed the effect of hookworm (Necator americanus) infection and anthelmintic treatment on naturally acquired antibody responses against GMZ2 and constituent antigens. Methods This longitudinal cross-sectional study was conducted in the Kintampo North Municipality of Ghana. Blood and stool samples were taken from 158 individuals (4–88 years old) infected with either P. falciparum alone (n = 59) or both hookworm and P. falciparum (n = 63) and uninfected endemic controls (n = 36). Stool hookworm infection was detected by the Kato-Katz method and PCR. Malaria parasitaemia was detected by RDT, light microscopy and P. falciparum-specific 18S rRNA gene PCR. Serum samples were obtained prior to hookworm treatment with a single dose of albendazole (400 mg) and 3 weeks (21 days) after treatment. Levels of IgG1, IgG3 and IgM against GMZ2, MSP3 and GLURP R0 were measured by ELISA and compared among the groups, before and after treatment. Results Participants with P. falciparum and hookworm co-infection had significantly higher IgG3 levels to GMZ2 than those with only P. falciparum infection and negative control (p < 0.05) at baseline. Treatment with albendazole led to a significant reduction in IgG3 levels against both GMZ2 and GLURP R0. Similarly, IgM and IgG1 levels against MSP3 also decreased following deworming treatment. Conclusion Individuals with co-infection had higher antibody responses to GMZ2 antigen. Treatment of hookworm/malaria co-infection resulted in a reduction in antibody responses against GMZ2 and constituent antigens after albendazole treatment. Thus, hookworm infection and treatment could have a potential implication on malaria vaccine efficacy.