scholarly journals Multiple drug resistance in the canine hookworm Ancylostoma caninum: an emerging threat?

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Pablo D. Jimenez Castro ◽  
Sue B. Howell ◽  
John J. Schaefer ◽  
Russell W. Avramenko ◽  
John S. Gilleard ◽  
...  

Abstract Background The canine hookworm, Ancylostoma caninum is the most prevalent and important intestinal nematode parasite of dogs in the USA. Hookworms are typically well controlled by treatment with all commonly used anthelmintics that are approved for this use in dogs. However, in the past few years, cases of recurrent/persistent canine hookworm infections appear to have dramatically increased, suggesting that anthelmintic resistance (AR) may have evolved in this parasite. These cases are highly overrepresented by greyhounds, but multiple other breeds are also represented. The aim of this study was to characterize several of these suspected resistant isolates using in vitro, genetic and clinical testing to determine if these cases represent true anthelmintic resistance in A. caninum. Methods Fecal samples containing hookworm eggs from three cases of persistent hookworm infections; one from a greyhound, one from a miniature schnauzer and one from a hound-mix, were received by our laboratory. These were then used to establish infections in laboratory dogs and to perform egg hatch assays (EHA) and larval development assays (LDA) for detecting resistance to benzimidazoles and macrocyclic lactones, respectively. Additional EHA and LDA were performed on eggs recovered from the laboratory-induced infections. Fecal egg count reduction tests were performed to detect resistance to pyrantel. Deep amplicon sequencing assays were developed to measure the frequency of non-synonymous single nucleotide polymorphisms (SNP) at codons 167, 198 and 200 of the A. caninum isotype-1 β-tubulin gene. Results Resistance ratios for the three A. caninum isolates tested ranged from 6.0 to > 100 and 5.5 to 69.8 for the EHA and LDA, respectively. Following treatment with pyrantel, reduction in faecal egg counts was negative or 0%. Deep amplicon sequencing of the isotype-1 β-tubulin gene identified a high frequency of resistance-associated SNPs at codon 167 in all three resistant isolates and in two additional clinical cases. Conclusions These data conclusively demonstrate multiple anthelmintic resistance in multiple independent isolates of A. caninum, strongly suggesting that this is an emerging problem in the USA. Furthermore, evidence suggest that these resistant hookworms originate from racing greyhound farms and kennels, though additional research is needed to confirm this.

2019 ◽  
Author(s):  
Pablo D. Jimenez Castro ◽  
Sue Howell ◽  
John. J. Schaefer ◽  
Russell. W. Avramenko ◽  
John. S. Gilleard ◽  
...  

AbstractIn the past few years, diagnoses by veterinarians of recurrent canine hookworm infections have dramatically increased, suggesting that anthelmintic resistance (AR) may have evolved in the parasite Ancylostoma caninum. To investigate this, we established three “suspected-resistant” and two susceptible A. caninum isolates in research dogs for further study. The egg hatch assay (EHA) and the larval development assay (LDA) were used for detecting resistance to benzimidazoles, and macrocyclic lactones, respectively. Resistance ratios ranged from 6.0 to >100 and 5.5-69.8 for the EHA and LDA, respectively. Following treatments with fenbendazole, pyrantel and milbemycin oxime, reduction in faecal egg counts ranged from 64–86%, 0–72% and 58–92%, respectively. Deep amplicon sequencing of the isotype-1 β tubulin gene identified a high frequency of resistance-associated single nucleotide polymorphisms at codon 167 in the resistant isolates and clinical cases.. These data conclusively demonstrate multiple anthelmintic resistance in A. caninum, and provide pivotal evidence that this is an emerging problem in the United States. Consequently, these findings should provide some concern to the global health community, as the scale-up of mass drug administration for soil-transmitted helminths (STH) is now placing similar selection pressures for benzimidazole resistance in human hookworms.


2021 ◽  
Author(s):  
Pablo D. Jimenez Castro ◽  
Abhinaya Venkatesan ◽  
Elizabeth Redman ◽  
Rebecca Chen ◽  
Abigail Malatesta ◽  
...  

AbstractThe hookworm Ancylostoma caninum is the most prevalent nematode parasite of dogs. Recently, we confirmed multiple-drug resistance (MDR) in several A. caninum isolates to all anthelmintic drug classes approved for the treatment of hookworms in dogs in the United States (USA). Cases of MDR hookworms appear to be highly overrepresented in greyhounds, suggesting that the MDR worms evolved on racing greyhound farms/kennels. The aims of this study were to evaluate the range of drug-resistant phenotypes and genotypes of the A. caninum infecting greyhounds. Fecal samples from recently retired greyhounds originating from geographically diverse areas of the USA were acquired from two greyhound adoption kennels, one active greyhound racing kennel, and three veterinary practices that work with adoption kennels. Fecal egg counts (FECs) were performed on fecal samples from 219 greyhounds, and despite almost all the dogs having been treated with one or more anthelmintics in the previous two to four weeks, the mean FEC was 822.4 eggs per gram (EPG). Resistance to benzimidazoles and macrocyclic lactones were measured using the egg hatch assay (EHA) and the larval development assay (LDA) respectively. We performed 23 EHA and 22 LDA on either individual or pooled feces, representing 81 animals. Mean and median IC50 and IC95 values for the EHA were 5.3 uM, 3.6 uM, and 24.5 uM, 23.4 uM respectively. For the LDA, mean and median IC50 values were 749.8 nM, >1000 nM respectively. These values range from 62 to 68 times higher than those we measured in our susceptible laboratory isolates. Pre-treatment fecal samples could not be obtained, however, post-treatment samples representing 219 greyhounds were collected. For samples collected <10 days post-treatment with albendazole, moxidectin, or a combination of febantel-pyrantel-moxidectin, the mean FEC were 349, 333, and 835 EPG, respectively. Samples collected 10-21 days post-treatment with albendazole, moxidectin, or pyrantel, yielded mean FEC of 1874, 335, and 600 EPG, respectively. Samples collected >21 days post-treatment with albendazole or moxidectin yielded mean FEC of 1819 and 1117 EPG, respectively. We obtained DNA from hookworm eggs isolated from 70 fecal samples, comprised of 60 individual dogs and 10 pools from multiple dogs. Deep sequencing of the isotype 1 β-tubulin gene revealed the presence of the F167Y (TTC>TAC) resistance polymorphism in 99% of these samples, with 69% having ≥75% resistant allele frequency. No resistance-associated polymorphisms were seen at any of the other β-tubulin codons previously reported as associated with benzimidazole resistance in Strongylid nematodes. These clinical, in vitro, and genetic data provide strong evidence that racing and recently retired greyhound dogs in the USA are infected with MDR A. caninum at very high levels in terms of both prevalence and infection intensity.


2010 ◽  
Vol 85 (2) ◽  
pp. 196-203 ◽  
Author(s):  
D. Pan ◽  
S. Das ◽  
A.K. Bera ◽  
S. Bandyopadhyay ◽  
S. Bandyopadhyay ◽  
...  

AbstractCystic echinococcosis (CE) caused by the larval stage of Echinococcus granulosus is a disease that affects both humans and animals. In humans the disease is treated by surgery with a supplementary option of chemotherapy with a benzimidazole compound. During the present study heat-shock protein 60 (HSP 60) was identified as one of the most frequently expressed biomolecules by E. granulosus after albendazole treatment. Data were correlated with 14-3-3 protein signature, and overexpression of this molecule after albendazole induction was an indicator of cell survival and signal transduction during in vitro maintenance of E. granulosus for up to 72 h. This observation was further correlated with a uniform expression pattern of a housekeeping gene (actin II). Out of three β-tubulin gene isoforms of E. granulosus, β-tubulin gene isoform 2 showed a conserved point mutation indicative of benzimidazole resistance.


2008 ◽  
Vol 74 (9) ◽  
pp. 2834-2840 ◽  
Author(s):  
Guojun Wang ◽  
Takeshi Hosaka ◽  
Kozo Ochi

ABSTRACT We recently described a new method to activate antibiotic production in bacteria by introducing a mutation conferring resistance to a drug such as streptomycin, rifampin, paromomycin, or gentamicin. This method, however, enhanced antibiotic production by only up to an order of magnitude. Working with Streptomyces coelicolor A3(2), we established a method for the dramatic activation of antibiotic production by the sequential introduction of multiple drug resistance mutations. Septuple and octuple mutants, C7 and C8, thus obtained by screening for resistance to seven or eight drugs, produced huge amounts (1.63 g/liter) of the polyketide antibiotic actinorhodin, 180-fold higher than the level produced by the wild type. This dramatic overproduction was due to the acquisition of mutant ribosomes, with aberrant protein and ppGpp synthesis activity, as demonstrated by in vitro protein synthesis assays and by the abolition of antibiotic overproduction with relA disruption. This new approach, called “ribosome engineering,” requires less time, cost, and labor than other methods and may be widely utilized for bacterial strain improvement.


Medicines ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 21 ◽  
Author(s):  
Partha Karmakar ◽  
Vishwanath Gaitonde

Multiple drug resistance (MDR) for the treatment of bacterial infection has been a significant challenge since the beginning of the 21st century. Many of the small molecule-based antibiotic treatments have failed on numerous occasions due to a surge in MDR, which has claimed millions of lives worldwide. Small particles (SPs) consisting of metal, polymer or carbon nanoparticles (NPs) of different sizes, shapes and forms have shown considerable antibacterial effect over the past two decades. Unlike the classical small-molecule antibiotics, the small particles are less exposed so far to the bacteria to trigger a resistance mechanism, and hence have higher chances of fighting the challenge of the MDR process. Until recently, there has been limited progress of clinical treatments using NPs, despite ample reports of in vitro antibacterial efficacy. In this review, we discuss some recent and unconventional strategies that have explored the antibacterial efficacy of these small particles, alone and in combination with classical small molecules in vivo, and demonstrate possibilities that are favorable for clinical translations in near future.


1998 ◽  
Vol 42 (5) ◽  
pp. 1088-1092 ◽  
Author(s):  
G. M. Eliopoulos ◽  
C. B. Wennersten ◽  
H. S. Gold ◽  
T. Schülin ◽  
M. Souli ◽  
...  

ABSTRACT In the course of clinical studies with the investigational streptogramin antimicrobial dalfopristin-quinupristin, isolates of vancomycin-resistant Enterococcus faecium were referred to our laboratory from across the United States. Seventy-two percent of the strains were of the VanA type, phenotypically and genotypically, while 28% were of the VanB type. High-level resistance to streptomycin or gentamicin was observed in 86 and 81%, respectively, of the VanA strains but in only 69 and 66%, respectively, of the VanB strains. These enterococci were resistant to ampicillin (MIC for 50% of the isolates tested [MIC50] and MIC90, 128 and 256 μg/ml, respectively) and to the other approved agents tested, with the exception of chloramphenicol (MIC90, 8 μg/ml) and novobiocin (MIC90, 1 μg/ml). Considering all of the isolates submitted, dalfopristin-quinupristin inhibited 86.4% of them at concentrations of ≤1 μg/ml and 95.1% of them at ≤2 μg/ml. However, for the data set comprised of only the first isolate submitted for each patient, 94.3% of the strains were inhibited at concentrations of ≤1 μg/ml and 98.9% were inhibited at concentrations of ≤2 μg/ml. Multiple drug resistance was very common among these isolates of vancomycin-resistant E. faecium, while dalfopristin-quinupristin inhibited the majority at concentrations that are likely to be clinically relevant.


2008 ◽  
Vol 27 (2) ◽  
pp. 143-147 ◽  
Author(s):  
Lorne J Brandes

N,N-diethyl-2-[4-(phenylmethyl) phenoxy] ethanamine (DPPE; tesmilifene) is a novel anti-histaminic and chemopotentiating agent that has a hormetic effect on DNA synthesis in MCF (Michigan Cancer Foundation)-7 human breast cancer cells in vitro and stimulates the growth of experimental tumors in rodents. In a prospectively randomized phase three trial (NCIC MA.19), 152 patients who were co-administered DPPE and doxorubicin survived 50% longer ( P < 0.03) than 153 patients who were administered the same dose and schedule of doxorubicin alone. At clinically relevant in vitro concentrations that do not inhibit the P-glycoprotein (P-gp) pump, DPPE selectively sensitizes the cancer cells that express the multiple drug resistance phenotype, making them more susceptible to the cytotoxic effects of chemotherapeutic agents, including anthracyclines and taxanes. Based on its previously demonstrated interaction with histamine at CYP3A4, a P450 that metabolizes arachidonic acid, and its induction of high levels of prostacyclin in the gut of rodents, modulation by DPPE of the intracellular concentration of arachidonate products, such as hydroxyeicosatetraeinoic acids, implicated in increased cancer cell proliferation and metastasis, is postulated.


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