Trypanosoma cruzi:Study of the Distribution of Two Widespread Clonal Genotypes in BolivianTriatoma infestansVectors Shows a High Frequency of Mixed Infections

Background Giardia duodenalis is a leading cause of gastroenteritis worldwide. Humans are mainly infected by two different subtypes, i.e., assemblage A and B. Genotyping is hampered by allelic sequence heterozygosity (ASH) mainly in assemblage B, and by occurrence of mixed infections. Here we assessed the suitability of current genotyping protocols of G. duodenalis for epidemiological applications such as molecular tracing of transmission chains. Methodology/Principal findings Two G. duodenalis isolate collections, from an outpatient tropical medicine clinic and from several primary care laboratories, were characterized by assemblage-specific qPCR (TIF, CATH gene loci) and a common multi locus sequence typing (MLST; TPI, BG, GDH gene loci). Assemblage A isolates were further typed at additional loci (HCMP22547, CID1, RHP26, HCMP6372, DIS3, NEK15411). Of 175/202 (86.6%) patients the G. duodenalis assemblage could be identified: Assemblages A 25/175 (14.3%), B 115/175 (65.7%) and A+B mixed 35/175 (20.0%). By incorporating allelic sequence heterozygosity in the analysis, the three marker MLST correctly identified 6/ 9 (66,7%) and 4/5 (80.0%) consecutive samples from chronic assemblage B infections in the two collections, respectively, and identified a cluster of five independent patients carrying assemblage B parasites of identical MLST type. Extended MLST for assemblage A altogether identified 5/6 (83,3%) consecutive samples from chronic assemblage A infections and 15 novel genotypes. Based on the observed A+B mixed infections it is estimated that only 75% and 50% of assemblage A or B only cases represent single strain infections, respectively. We demonstrate that typing results are consistent with this prediction. Conclusions/Significance Typing of assemblage A and B isolates with resolution for epidemiological applications is possible but requires separate genotyping protocols. The high frequency of multiple infections and their impact on typing results are findings with immediate consequences for result interpretation in this field.

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Cryptosporidium in fish: alternative sequencing approaches and analyses at multiple loci to resolve mixed infections

Parasitology ◽

10.1017/s0031182017001214 ◽

2017 ◽

Vol 144 (13) ◽

pp. 1811-1820 ◽

Cited By ~ 9

Author(s):

ANDREA PAPARINI ◽

RONGCHANG YANG ◽

LINDA CHEN ◽

KAISING TONG ◽

SUSAN GIBSON-KUEH ◽

...

Keyword(s):

Genetic Diversity ◽

High Frequency ◽

Sanger Sequencing ◽

Multiple Infections ◽

Mixed Infections ◽

Multiple Loci ◽

The Rich ◽

Next Generation Sequencing Ngs ◽

Molecular Parasitology ◽

Generation Sequencing

SUMMARYCurrently, the systematics, biology and epidemiology of piscine Cryptosporidium species are poorly understood. Here, we compared Sanger ‒ and next-generation ‒ sequencing (NGS), of piscine Cryptosporidium, at the 18S rRNA and actin genes. The hosts comprised 11 ornamental fish species, spanning four orders and eight families. The objectives were: to (i) confirm the rich genetic diversity of the parasite and the high frequency of mixed infections; and (ii) explore the potential of NGS in the presence of complex genetic mixtures. By Sanger sequencing, four main genotypes were obtained at the actin locus, while for the 18S locus, seven genotypes were identified. At both loci, NGS revealed frequent mixed infections, consisting of one highly dominant variant plus substantially rarer genotypes. Both sequencing methods detected novel Cryptosporidium genotypes at both loci, including a novel and highly abundant actin genotype that was identified by both Sanger sequencing and NGS. Importantly, this genotype accounted for 68·9% of all NGS reads from all samples (249 585/362 372). The present study confirms that aquarium fish can harbour a large and unexplored Cryptosporidium genetic diversity. Although commonly used in molecular parasitology studies, nested PCR prevents quantitative comparisons and thwarts the advantages of NGS, when this latter approach is used to investigate multiple infections.

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High Frequency of Chlamydia trachomatis Mixed Infections Detected by Microarray Assay in South American Samples

PLoS ONE ◽

10.1371/journal.pone.0153511 ◽

2016 ◽

Vol 11 (4) ◽

pp. e0153511 ◽

Cited By ~ 8

Author(s):

Lucía Gallo Vaulet ◽

Carolina Entrocassi ◽

Ana I. Portu ◽

Erica Castro ◽

Susana Di Bartolomeo ◽

...

Keyword(s):

Chlamydia Trachomatis ◽

High Frequency ◽

Mixed Infections ◽

South American ◽

Microarray Assay

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HELMINTHS OF MICROTINAE IN WESTERN MONTANA

Canadian Journal of Zoology ◽

10.1139/z67-038 ◽

1967 ◽

Vol 45 (3) ◽

pp. 269-274 ◽

Cited By ~ 7

Author(s):

John M. Kinsella

Keyword(s):

High Frequency ◽

New Records ◽

First Record ◽

Microtus Pennsylvanicus ◽

Western Montana ◽

Seasonal Patterns ◽

Mixed Infections ◽

Microtus Montanus ◽

Phenacomys Intermedius ◽

Aspiculuris Tetraptera

Seventeen species of helminths were found in 134 voles of 5 species (Phenacomys intermedius, Clethrionomys gapperi, Microtus longicaudus, Microtus montanus, Microtus pennsylvanicus) collected in 1964 and 1965 in western Montana. Ten new records for North America and 26 new records for Montana were recorded. Seasonal patterns of infection were noted in Quinqueserialis quinqueserialis and Paranoplocephala infrequens. The taxonomy of the nematode Heligmosomum dubius (Baylis, 1926) Tenora, 1958 was discussed. The first record of Aspiculuris tetraptera in. microitne rodents and the second record of Pelodera sp. in the orbits of North American rodents were reported. A high frequency of mixed infections of the digestive tract was found, usually accompanied by a pronounced stratification of the helminths within the tract.

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Detection of different enteric viruses in children with diarrheal disease: evidence of the high frequency of mixed infections

Access Microbiology ◽

10.1099/acmi.0.000010 ◽

2019 ◽

Vol 1 (2) ◽

Cited By ~ 3

Author(s):

Vaishali S. Tatte ◽

Varanasi Gopalkrishna

Keyword(s):

High Frequency ◽

Diarrheal Disease ◽

Enteric Viruses ◽

Mixed Infections

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Intestinal parasites in two indigenous ethnic groups in northwestern Amazonia

Acta Amazonica ◽

10.1590/1809-4392201505883 ◽

2016 ◽

Vol 46 (3) ◽

pp. 241-246 ◽

Cited By ~ 1

Author(s):

Raylene Andrade OLIVEIRA ◽

Rodrigo GURGEL-GONÇALVES ◽

Eleuza Rodrigues MACHADO

Keyword(s):

Ethnic Groups ◽

Indigenous People ◽

High Frequency ◽

Intestinal Parasites ◽

Mixed Infections ◽

Risk Of Infection ◽

Protozoan Parasites ◽

Education Programs ◽

Stool Samples ◽

Reduce Risk

ABSTRACT Approximately 90% of the population in the northwestern Amazonia is composed of indigenous people and their healthcare is still a challenge. The objective of this study was to determine the frequency of parasites in two indigenous ethnic groups (Baré and Baniwa) in northwestern Amazonia. Stool samples from 270 individuals (199 Baniwa and 71 Baré) were analyzed using Richie's method and the spontaneous sedimentation method. Statistical differences among the proportions of infected individuals based on gender, age, and ethnicity were determined. All individuals were infected by protozoans or helminths. The most frequent parasites in the indigenous people were Ascaris lumbricoides (73%), Entamoeba spp. (53%), and Giardia intestinalis (48%). Protozoan parasites were more common among children aged 0-12 years; however, the frequency of helminths, such as hookworms and A. lumbricoides, was higher in adults. There were no significant differences in parasite frequencies between different genders or ethnic groups. Mixed infections by two or more protozoan and/or helminth species were detected in 96% of individuals. One individual was infected by 14 species. A high frequency of intestinal parasites was found in Baré and Baniwa ethnic groups. Improvements to infrastructure and health education programs are required to reduce risk of infection by intestinal parasites.

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Characterization of incompletely typed rotavirus strains from Guinea-Bissau: identification of G8 and G9 types and a high frequency of mixed infections

Virology ◽

10.1016/s0042-6822(03)00153-3 ◽

2003 ◽

Vol 311 (1) ◽

pp. 125-133 ◽

Cited By ~ 40

Author(s):

T.K Fischer ◽

N.A Page ◽

D.D Griffin ◽

J Eugen-Olsen ◽

A.G Pedersen ◽

...

Keyword(s):

High Frequency ◽

Mixed Infections ◽

Guinea Bissau

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The Microstructure of Steatite (Protoenstatite)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118102 ◽

1985 ◽

Vol 43 ◽

pp. 236-237

Author(s):

W. E. Lee ◽

A. H. Heuer

Keyword(s):

High Frequency ◽

Glass Ceramics ◽

Magnesium Silicate ◽

Beam Current ◽

Glassy Matrix ◽

Angle Of Incidence ◽

X Ray ◽

Mechanical And Electrical Properties ◽

Argon Ions ◽

High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

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