scholarly journals Challenges for Cryptosporidium Population Studies

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 894
Author(s):  
Rodrigo P. Baptista ◽  
Garrett W. Cooper ◽  
Jessica C. Kissinger

Cryptosporidiosis is ranked sixth in the list of the most important food-borne parasites globally, and it is an important contributor to mortality in infants and the immunosuppressed. Recently, the number of genome sequences available for this parasite has increased drastically. The majority of the sequences are derived from population studies of Cryptosporidium parvum and Cryptosporidium hominis, the most important species causing disease in humans. Work with this parasite is challenging since it lacks an optimal, prolonged, in vitro culture system, which accurately reproduces the in vivo life cycle. This obstacle makes the cloning of isolates nearly impossible. Thus, patient isolates that are sequenced represent a population or, at times, mixed infections. Oocysts, the lifecycle stage currently used for sequencing, must be considered a population even if the sequence is derived from single-cell sequencing of a single oocyst because each oocyst contains four haploid meiotic progeny (sporozoites). Additionally, the community does not yet have a set of universal markers for strain typing that are distributed across all chromosomes. These variables pose challenges for population studies and require careful analyses to avoid biased interpretation. This review presents an overview of existing population studies, challenges, and potential solutions to facilitate future population analyses.

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1860
Author(s):  
Patricia Diez-Echave ◽  
Izaskun Martín-Cabrejas ◽  
José Garrido-Mesa ◽  
Susana Langa ◽  
Teresa Vezza ◽  
...  

Limosilactobacillus reuteri INIA P572 is a strain able to produce the antimicrobial compound reuterin in dairy products, exhibiting a protective effect against some food-borne pathogens. In this study, we investigated some probiotic properties of this strain such as resistance to gastrointestinal passage or to colonic conditions, reuterin production in a colonic environment, and immunomodulatory activity, using different in vitro and in vivo models. The results showed a high resistance of this strain to gastrointestinal conditions, as well as capacity to grow and produce reuterin in a human colonic model. Although the in vitro assays using the RAW 264.7 macrophage cell line did not demonstrate direct immunomodulatory properties, the in vivo assays using a Dextran Sulphate Sodium (DSS)-induced colitic mice model showed clear immunomodulatory and protective effects of this strain.


Author(s):  
Jon Bruss ◽  
Troy Lister ◽  
Vipul K. Gupta ◽  
Emily Stone ◽  
Lisa Morelli ◽  
...  

Carbapenem-resistant Acinetobacter baumannii and Enterobacterales are identified as urgent threats, and multidrug-resistant (MDR) Pseudomonas aeruginosa and extended-spectrum beta-lactamases (ESBL)-producing pathogens are identified as a serious threat by the Centers for Disease Control and Prevention (CDC). SPR206 is a novel polymyxin derivative with potent in vitro and in vivo activity against A. baumannii , P. aeruginosa , and multiple clinically important species of Enterobacterales, including multidrug- and extensively drug-resistant strains. This was a first-in-human (FIH) double-blind, placebo-controlled, single- and multiple ascending dose study of the safety, tolerability, and pharmacokinetics (PK) of SPR206 in 94 healthy subjects. Following IV administration (1 h infusion) at single doses of 10 mg to 400 mg and multiple doses of 25 mg to 150 mg q8h for 7 days and 100 mg q8h for 14 days, SPR206 was generally safe and generally well tolerated. While the incidence of adverse events increased with dose, most were of mild severity. Systemic exposure (C max and AUC) to SPR206 was approximately dose proportional, time to peak concentrations ranged from 1.1 to 1.3 hours, and half-life ranged from 2.4 to 4.1 hours. No appreciable accumulation occurred with repeated dosing of SPR206 and trough concentrations suggest that steady state was achieved by Day 2. Urinary excretion of unchanged SPR206 was dose dependent across single- (SAD) and multiple ascending dose (MAD) cohorts, and the percentage of dose excreted as SPR206 was up to >50%. Importantly, no evidence of nephrotoxicity was observed over 14 days of 100 mg q8h dosing of SPR206; a dosing regimen anticipated to exceed requirements for clinical efficacy.


2018 ◽  
Vol 62 (4) ◽  
pp. e01505-17 ◽  
Author(s):  
R. S. Jumani ◽  
K. Bessoff ◽  
M. S. Love ◽  
P. Miller ◽  
E. E. Stebbins ◽  
...  

ABSTRACTCryptosporidiosis causes life-threatening diarrhea in children under the age of 5 years and prolonged diarrhea in immunodeficient people, especially AIDS patients. The standard of care, nitazoxanide, is modestly effective in children and ineffective in immunocompromised individuals. In addition to the need for new drugs, better knowledge of drug properties that drivein vivoefficacy is needed to facilitate drug development. We report the identification of a piperazine-based lead compound forCryptosporidiumdrug development, MMV665917, and a new pharmacodynamic method used for its characterization. The identification of MMV665917 from the Medicines for Malaria Venture Malaria Box was followed by dose-response studies,in vitrotoxicity studies, and structure-activity relationship studies using commercial analogues. The potency of this compound againstCryptosporidium parvumIowa and field isolates was comparable to that againstCryptosporidium hominis. Furthermore, unlike nitazoxanide, clofazimine, and paromomycin, MMV665917 appeared to be curative in a NOD SCID gamma mouse model of chronic cryptosporidiosis. MMV665917 was also efficacious in a gamma interferon knockout mouse model of acute cryptosporidiosis. To determine if efficacy in this mouse model of chronic infection might relate to whether compounds are parasiticidal or parasitistatic forC. parvum, we developed a novelin vitroparasite persistence assay. This assay suggested that MMV665917 was parasiticidal, unlike nitazoxanide, clofazimine, and paromomycin. The assay also enabled determination of the concentration of the compound required to maximize the rate of parasite elimination. This time-kill assay can be used to prioritize early-stageCryptosporidiumdrug leads and may aid in planningin vivoefficacy experiments. Collectively, these results identify MMV665917 as a promising lead and establish a new method for characterizing potential anticryptosporidial agents.


2020 ◽  
Vol 7 ◽  
Author(s):  
Jennifer C. Lutz ◽  
Susan L. Johnson ◽  
Kimberly J. Duprey ◽  
Paul J. Taylor ◽  
Henry William Vivanco-Mackie ◽  
...  

The alpaca (Vicugna pacos) is an important species for the production of fiber and food. Genetic improvement programs for alpacas have been hindered, however, by the lack of field-practical techniques for artificial insemination and embryo transfer. In particular, successful techniques for the cryopreservation of alpaca preimplantation embryos have not been reported previously. The objective of this study was to develop a field-practical and efficacious technique for cryopreservation of alpaca preimplantation embryos using a modification of a vitrification protocol originally devised for horses and adapted for dromedary camels. Four naturally cycling non-superovulated Huacaya females serving as embryo donors were mated to males of proven fertility. Donors received 30 μg of gonadorelin at the time of breeding, and embryos were non-surgically recovered 7 days after mating. Recovered embryos (n = 4) were placed individually through a series of three vitrification solutions at 20°C (VS1: 1.4 M glycerol; VS2: 1.4 M glycerol + 3.6 M ethylene glycol; VS3: 3.4 M glycerol + 4.6 M ethylene glycol) before loading into an open-pulled straw (OPS) and plunging directly into liquid nitrogen for storage. At warming, each individual embryo was sequentially placed through warming solutions (WS1: 0.5 M galactose at 37°C; WS2: 0.25 M galactose at 20°C), and warmed embryos were incubated at 37°C in 5% CO2 in humidified air for 20–22 h in 1 ml Syngro® holding medium supplemented with 10% (v/v) alpaca serum to perform an initial in vitro assessment of post-warming viability. Embryos whose diameter increased during culture (n = 2) were transferred individually into synchronous recipients, whereas embryos that did not grow (n = 2) were transferred together into a single recipient to perform an in vivo assessment of post-warming viability. Initial pregnancy detection was performed ultrasonographically 29 days post-transfer when fetal heartbeat could be detected, and one of three recipients was pregnant (25% embryo survival rate). On November 13, 2019, the one pregnant recipient delivered what is believed to be the world's first cria produced from a vitrified-warmed alpaca embryo.


2018 ◽  
Vol 42 (22) ◽  
pp. 18437-18447 ◽  
Author(s):  
Murugesan Gowri ◽  
Kannan Suganya ◽  
Nachimuthu Latha ◽  
Marudhamuthu Murugan ◽  
Mukhtar Ahmed ◽  
...  

Food borne infection is a serious complication caused by Listeria monocytogenes (L. monocytogenes), a dangerous bacteria.


Parasitology ◽  
2009 ◽  
Vol 137 (3) ◽  
pp. 589-603 ◽  
Author(s):  
J. KEISER

SUMMARYSchistosomiasis and food-borne trematodiases are chronic parasitic diseases affecting millions of people mostly in the developing world. Additional drugs should be developed as only few drugs are available for treatment and drug resistance might emerge. In vitro and in vivo whole parasite screens represent essential components of the trematodicidal drug discovery cascade. This review describes the current state-of-the-art of in vitro and in vivo screening systems of the blood fluke Schistosoma mansoni, the liver fluke Fasciola hepatica and the intestinal fluke Echinostoma caproni. Examples of in vitro and in vivo evaluation of compounds for activity are presented. To boost the discovery pipeline for these diseases there is a need to develop validated, robust high-throughput in vitro systems with simple readouts.


2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Solomon Habtemariam

Rosemary (Rosmarinus officinalisL.) is one of the most economically important species of the family Lamiaceae. Native to the Mediterranean region, the plant is now widely distributed all over the world mainly due to its culinary, medicinal, and commercial uses including in the fragrance and food industries. Among the most important group of compounds isolated from the plant are the abietane-type phenolic diterpenes that account for most of the antioxidant and many pharmacological activities of the plant. Rosemary diterpenes have also been shown in recent years to inhibit neuronal cell death induced by a variety of agents bothin vitroandin vivo. The therapeutic potential of these compounds for Alzheimer’s disease (AD) is reviewed in this communication by giving special attention to the chemistry of the compounds along with the various pharmacological targets of the disease. The multifunctional nature of the compounds from the general antioxidant-mediated neuronal protection to other specific mechanisms including brain inflammation and amyloid beta (Aβ) formation, polymerisation, and pathologies is discussed.


2021 ◽  
Author(s):  
Yongtao Xiao ◽  
weipeng wang ◽  
Ying lu ◽  
xinbei tian ◽  
shanshan chen ◽  
...  

Salmonella Typhimurium is gram-negative flagellated bacteria that can cause food-borne gastroenteritis and diarrhea in humans and animals. The regenerating islet-derived family member 4 (Reg4) is overexpressed in the gastrointestinal tract during intestinal inflammation. However, the role of Reg4 in the intestinal inflammation induced by Salmonella Typhimurium is largely unknown. In this study, we reported for the first time that Reg4 has bactericidal activity against intestinal infection caused by Salmonella Typhimurium. In vivo, Reg4 could reduce the colonization of Salmonella Typhimurium and attenuate intestinal inflammation in the Salmonella Typhimurium-infected model. Additionally, the mice with the epithelial cell specific deletion of Reg4 (Reg4ΔIEC) exhibited more severe intestinal inflammation and more colonization of Salmonella Typhimurium. However, the administration of Reg4 could reverse these negative impacts. In vitro, Reg4 protein was showed to inhibit the growth of Salmonella Typhimurium. We further investigate the function motif of Reg4 and find that the "HDPQK" motif in Reg4 is essential to its bactericidal activity. Reg4 exerted the bactericidal effect by binding to the flagellin of Salmonella Typhimurium and suppressing its motility, adhesion, and invasion to the intestinal epithelia. In conclusion, our findings identify Reg4 as a novel antimicrobial peptide against infection by Salmonella Typhimurium and explore its possible mechanism, which may be of great significance for developing novel agents against flagellated micro pathogens.


2019 ◽  
Vol 220 (2) ◽  
pp. 285-293 ◽  
Author(s):  
Sangun Lee ◽  
Melanie Ginese ◽  
Don Girouard ◽  
Gillian Beamer ◽  
Christopher D Huston ◽  
...  

Abstract Background Cryptosporidiosis, an enteric protozoon, causes substantial morbidity and mortality associated with diarrhea in children <2 years old in low- to middle-income countries. There is no vaccine and treatments are inadequate. A piperazine-based compound, MMV665917, has in vitro and in vivo efficacy against Cryptosporidium parvum. In this study, we evaluated the efficacy of MMV665917 in gnotobiotic piglets experimentally infected with Cryptosporidium hominis, the species responsible for >75% of diarrhea reported in these children. Methods Gnotobiotic piglets were orally challenged with C hominis oocysts, and oral treatment with MMV665917 was commenced 3 days after challenge. Oocyst excretion and diarrhea severity were observed daily, and mucosal colonization and lesions were recorded after necropsy. Results MMV665917 significantly reduced fecal oocyst excretion, parasite colonization and damage to the intestinal mucosa, and peak diarrheal symptoms, compared with infected untreated controls. A dose of 20 mg/kg twice daily for 7 days was more effective than 10 mg/kg. There were no signs of organ toxicity at either dose, but 20 mg/kg was associated with slightly elevated blood cholesterol and monocytes at euthanasia. Conclusions These results demonstrate the effectiveness of this drug against C hominis. Piperazine-derivative MMV665917 may potentially be used to treat human cryptosporidiosis; however, further investigations are required.


Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1454
Author(s):  
Satish K. Nemani ◽  
Jennifer L. Myskiw ◽  
Lise Lamoureux ◽  
Stephanie A. Booth ◽  
Valerie L. Sim

The majority of human prion diseases are sporadic, but acquired disease can occur, as seen with variant Creutzfeldt–Jakob disease (vCJD) following consumption of bovine spongiform encephalopathy (BSE). With increasing rates of cervid chronic wasting disease (CWD), there is concern that a new form of human prion disease may arise. Currently, there is no evidence of transmission of CWD to humans, suggesting the presence of a strong species barrier; however, in vitro and in vivo studies on the zoonotic potential of CWD have yielded mixed results. The emergence of different CWD strains is also concerning, as different strains can have different abilities to cross species barriers. Given that venison consumption is common in areas where CWD rates are on the rise, increased rates of human exposure are inevitable. If CWD was to infect humans, it is unclear how it would present clinically; in vCJD, it was strain-typing of vCJD prions that proved the causal link to BSE. Therefore, the best way to screen for CWD in humans is to have thorough strain-typing of harvested cervids and human CJD cases so that we will be in a position to detect atypical strains or strain shifts within the human CJD population.


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