Helminths and the transmammary route of infection

Parasitology ◽  
1981 ◽  
Vol 82 (2) ◽  
pp. 335-342 ◽  
Author(s):  
Grover C. Miller
Keyword(s):  
Mammary Glands ◽  
Life Cycles ◽  
Helminth Parasites ◽  
Intermediate Hosts ◽  
Sweet Potatoes ◽  
Infected Female ◽  
Larval Stages ◽  
Route Of Infection ◽  
Lactating Mammary Gland ◽  
Major Route

SUMMARYThe transfer of infective larval stages of helminths via the mammary glands is probably more common than generally recognized. Recent investigations of both natural and experimental infections of various animals have shown that the transmammary transmission of some helminths is a major avenue of infection. Other studies indicate that there are at least 13 helminth parasites which may be transmitted as prenatal infections and at least 17 transmitted via the mammary glands. The majority of these are nematodes. However, in one case the tetrathyridia of the cestode Mesocestoides was observed. In this report the life-cycle and transmission of 2 species of diplostomatid trematodes in the genus Pharyngostomoides is described. The raccoon, Procyon lotor, is the only definitive host; a planorbid snail, Menetus dilatatus, and a branchiobdellid annelid, Cambarincola osceola, a commensal on crayfishes, are intermediate hosts. Records for a period of 11 years are now available for the maternal transmission and longevity of this trematode. During this time one infected female raccoon was maintained in the laboratory on a diet of commercial dog food, sweet potatoes and corn. She produced 25 offspring, most of which were infected with Pharyngostomoides, through the 6th litter. There was a declining number of worms in each litter, ranging from nearly 2000 in one of the 1st litter, to none in the 7th litter. After nearly 12 years she continues to pass a few trematode ova. Rather than assume she has retained the same adult worms for 12 years, it is reasonable to conclude that mesocercariae move through her body and eventually mature in the intestine. Because the mesocercariae have a predilection for the lactating mammary gland, it seems likely that a hormonal influence is present. The transmammary transmission of larvae is a viable alternative in the life-cycles of a number of helminths, and in some instances it is probably the major route of infection.

Polychaetes as Intermediate Hosts of Helminth Parasites of Vertebrates: A Review

1971 ◽  
Vol 28 (10) ◽  
pp. 1385-1392 ◽  
Author(s):  
L. Margolis
Keyword(s):  
Helminth Parasites ◽  
Intermediate Hosts ◽  
Larval Stages ◽  
Aquatic Vertebrates

The role of polychaetes as intermediate hosts of helminth parasites of aquatic vertebrates is reviewed. Some 18–20 species of trematodes and three or four each of cestodes and nematodes are known to have larval stages in these annelids. There are no records of acanthocephalan larvae from polychaetes. Trematoda use polychaetes as first (three species) or second intermediate hosts. The polychaete hosts are found among various genera of Errantia, Sedentaria, and Myzostomida. Definitive hosts are mainly fishes, with a few species of trematodes and one of cestodes developing in birds, and apparently one genus of nematodes (two species) maturing in the lungs of seals. A list of polychaetes and their larval helminth parasites is given.

scholarly journals Molecular data reshape our understanding of the life cycles of three digeneans (Monorchiidae and Gymnophallidae) infecting the bivalve, Donax variabilis: it’s just a facultative host!

Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 34
Author(s):  
Kristina M. Hill-Spanik ◽  
Claudia Sams ◽  
Vincent A. Connors ◽  
Tessa Bricker ◽  
Isaure de Buron
Keyword(s):  
Gulf Of Mexico ◽  
Intermediate Host ◽  
Atlantic Coast ◽  
The United States ◽  
Life Cycles ◽  
Intermediate Hosts ◽  
Larval Stages ◽  
Complete Life Cycle ◽  
Morphological Criteria ◽  
Donax Variabilis

The coquina, Donax variabilis, is a known intermediate host of monorchiid and gymnophallid digeneans. Limited morphological criteria for the host and the digeneans’ larval stages have caused confusion in records. Herein, identities of coquinas from the United States (US) Atlantic coast were verified molecularly. We demonstrate that the current GenBank sequences for D. variabilis are erroneous, with the US sequence referring to D. fossor. Two cercariae and three metacercariae previously described in the Gulf of Mexico and one new cercaria were identified morphologically and molecularly, with only metacercariae occurring in both hosts. On the Southeast Atlantic coast, D. variabilis’ role is limited to being a facultative second intermediate host, and D. fossor, an older species, acts as both first and second intermediate hosts. Sequencing demonstrated 100% similarities between larval stages for each of the three digeneans. Sporocysts, single tail cercariae, and metacercariae in the incurrent siphon had sequences identical to those of monorchiid Lasiotocus trachinoti, for which we provide the complete life cycle. Adults are not known for the other two digeneans, and sequences from their larval stages were not identical to any in GenBank. Large sporocysts, cercariae (Cercaria choanura), and metacercariae in the coquinas’ foot were identified as Lasiotocus choanura (Hopkins, 1958) n. comb. Small sporocysts, furcocercous cercariae, and metacercariae in the mantle were identified as gymnophallid Parvatrema cf. donacis. We clarify records wherein authors recognized the three digenean species but confused their life stages, and probably the hosts, as D. variabilis is sympatric with cryptic D. texasianus in the Gulf of Mexico.

Influence of the transmission of parasites from prey fishes on the composition of the parasite community of a predatory fish

1995 ◽  
Vol 52 (S1) ◽  
pp. 233-245 ◽  
Author(s):  
E. Tellervo Valtonen ◽  
Markku Julkunen
Keyword(s):  
Parasite Community ◽  
Life Cycles ◽  
Predatory Fish ◽  
Helminth Parasites ◽  
Intermediate Hosts ◽  
Complex Life Cycles ◽  
Lota Lota ◽  
Gymnocephalus Cernuus ◽  
Adult Trematode ◽  
Bothnian Bay

Helminth parasites and diet of seven freshwater fishes (Lota lota and six common prey species) from the Bothnian Bay, Baltic Sea, were studied monthly or bimonthly during 1978. Twenty-one of the 32 parasites with complex life cycles were shared between Lota lota and its prey fishes and are thus transmissible from prey to predator. Gymnocephalus cernuus and L. lota had the greatest number of shared species (13). Larval and adult cestodes, nematodes, and acanthocephalans could re-establish in the predator, but only one adult trematode was capable of this transition. Infracommunity species diversity was highest in L. lota (eH′ = 3.54), which also had the most species (24), the highest mean number of species and individuals of a given species per fish (6.3 and 62, respectively), and the greatest number of worms in one fish (520). Variety of diet was key in determining exposure to parasite species. However, most specificity finally determined if a given parasite could establish and mature. No ecologically explicable suites of parasites were found in any fish species, except in a few cases where parasites used related intermediate hosts. However, the composition of these suites was not retained in the predator. Unlike in L. lota, important parasites of prey fishes were typically specialists.

Behaviours in trematode cercariae that enhance parasite transmission: patterns and processes

Parasitology ◽  
1994 ◽  
Vol 109 (S1) ◽  
pp. S3-S13 ◽  
Author(s):  
C. Combes ◽  
A. Fournier ◽  
H. Moné ◽  
A. Théron
Keyword(s):  
Definitive Host ◽  
External Environment ◽  
Life Cycles ◽  
Parasite Transmission ◽  
Intermediate Hosts ◽  
Larval Stages ◽  
Active Life ◽  
Host Life ◽  
Patterns And Processes ◽  
Almost All

Cercariae, like miracidia, are non-parasitic larval stages implicated in the life cycle of all trematodes for the host-to-host parasite transmission. Almost all cercariae are free-living in the external environment. With a few exceptions (cercariae of Halipegus occidualis (Halipegidae) can live several months, Shostak & Esch, 1990a), cercariae have a short active life during which they do not feed, living on accumulated reserves. Most cercariae encyst as metacercariae in second intermediate hosts which are prey of the definitive host; in certain species, the interruption of the active life is achieved by an encystment in the external environment (or a simple immobile waiting strategy in a few species). In some two-host life cycles, the cercariae develop into adults after penetration (this is the case for various species causing human schistosomiasis). Some cercariae do not leave the mollusc which must then be ingested by the definitive host.

Tranmission pattern differences of miracidia and cercariae larval stages of digenetic trematode parasites

2016 ◽  
Vol 61 (4) ◽  
Author(s):  
Michael R. Zimmermann ◽  
Kyle E. Luth ◽  
Gerald W. Esch
Keyword(s):  
Abiotic Factors ◽  
Field Studies ◽  
Life Cycles ◽  
Digenetic Trematode ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Complex Life Cycles ◽  
Larval Stages ◽  
Digenetic Trematodes ◽  
Trematode Parasites

AbstractDigenetic trematodes have complex life cycles involving multiple hosts and free-living larval stages. Some species have 2 lar-val stages that infect snails, with miracidia and cercariae using these molluscs as first and second intermediate hosts, respec-tively. Although both larval stages may infect the same snail species, this is accomplished using different chemical cues and may be influenced by different biotic and abiotic factors. Significant differences in the infection patterns of these parasitic stages regarding host size and density were observed in 2 separate field studies. The prevalence of sporocysts/rediae and mean abundance of

EFFECT OF LOCALLY IMPLANTED OESTROGEN ON THE RESPONSE OF THE RAT'S LACTATING MAMMARY GLAND TO OXYTOCIN

1973 ◽  
Vol 73 (4) ◽  
pp. 700-712 ◽  
Author(s):  
J. D. Bruce ◽  
X. Cofre ◽  
V. D. Ramirez
Keyword(s):  
Mammary Gland ◽  
Mammary Glands ◽  
Myoepithelial Cells ◽  
Recording System ◽  
Saline Infusion ◽  
High Dose ◽  
Low Doses ◽  
Milk Ejection ◽  
Lactating Mammary Gland ◽  
Small Rise

ABSTRACT On the day following delivery (day 1 of lactation) one abdominal mammary gland was implanted with oestrogen and the contralateral gland received an empty needle. At 2, 5 or 10 days of lactation the rats were anaesthetized with pentobarbital and the nipples of both abdominal glands were cannulated and their pressures recorded by means of transducers coupled to an amplifier and recording system. The normal mammary glands of 5-day lactating rats responded to very low doses of oxytocin (Syntocinon®, Sandoz) (5× 10−8 mU) with a rhythmic elevation in pressure. However, saline infusion also evoked a small rise in intra-mammary pressure. Earlier (2 days) and later (10 days) in lactation the responses were smaller. Oestrogen decreases significantly the milk ejection response to oxytocin, and the effect was maximal at day 10 of lactation. Histological observations confirmed the diminished reaction of the gland to oxytocin, since the milk was retained in the alveoli of rats bearing a mammary-oestrogen implant. A paradoxical rise in pressure was detected in normal as well as in oestrogen-implanted glands when the lowest dose of oxytocin was injected in lactating rats which had previously received a high dose of oxytocin (50 mU or 500 mU). These results reinforce the hypothesis that oestrogen alters the milk ejection response to oxytocin and that the mechanism is probably related to changes in the contractility of the myoepithelial cells.

scholarly journals Leeches as the intermediate host for strigeid trematodes: genetic diversity and taxonomy of the genera Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ewa Pyrka ◽  
Gerard Kanarek ◽  
Grzegorz Zaleśny ◽  
Joanna Hildebrand
Keyword(s):  
Intermediate Host ◽  
Life Cycles ◽  
Coi Gene ◽  
Small Rivers ◽  
Ecological Niches ◽  
Its2 Region ◽  
28S Rrna ◽  
Intermediate Hosts ◽  
Internal Transcribed Spacer Region ◽  
Wide Range

Abstract Background Leeches (Hirudinida) play a significant role as intermediate hosts in the circulation of trematodes in the aquatic environment. However, species richness and the molecular diversity and phylogeny of larval stages of strigeid trematodes (tetracotyle) occurring in this group of aquatic invertebrates remain poorly understood. Here, we report our use of recently obtained sequences of several molecular markers to analyse some aspects of the ecology, taxonomy and phylogeny of the genera Australapatemon and Cotylurus, which utilise leeches as intermediate hosts. Methods From April 2017 to September 2018, 153 leeches were collected from several sampling stations in small rivers with slow-flowing waters and related drainage canals located in three regions of Poland. The distinctive forms of tetracotyle metacercariae collected from leeches supplemented with adult Strigeidae specimens sampled from a wide range of water birds were analysed using the 28S rDNA partial gene, the second internal transcribed spacer region (ITS2) region and the cytochrome c oxidase (COI) fragment. Results Among investigated leeches, metacercariae of the tetracotyle type were detected in the parenchyma and musculature of 62 specimens (prevalence 40.5%) with a mean intensity reaching 19.9 individuals. The taxonomic generic affiliation of metacercariae derived from the leeches revealed the occurrence of two strigeid genera: Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928. Phylogenetic reconstructions based on the partial 28S rRNA gene, ITS2 region and partial COI gene confirmed the separation of the Australapatemon and Cotylurus clades. Taking currently available molecular data and our results into consideration, recently sequenced tetracotyle of Australapatemon represents most probably Au. minor; however, unclear phylogenetic relationships between Au. burti and Au. minor reduce the reliability of this conclusion. On the other hand, on the basis of the obtained sequences, supplemented with previously published data, the metacercariae of Cotylurus detected in leeches were identified as two species: C. strigeoides Dubois, 1958 and C. syrius Dubois, 1934. This is the first record of C. syrius from the intermediate host. Conclusions The results of this study suggest the separation of ecological niches and life cycles between C. cornutus (Rudolphi, 1808) and C. strigeoides/C. syrius, with potential serious evolutionary consequences for a wide range of host–parasite relationships. Moreover, phylogenetic analyses corroborated the polyphyletic character of C. syrius, the unclear status of C. cornutus and the separate position of Cotylurus raabei Bezubik, 1958 within Cotylurus. The data demonstrate the inconsistent taxonomic status of the sequenced tetracotyle of Australapatemon, resulting, in our opinion, from the limited availability of fully reliable, comparative sequences of related taxa in GenBank.

Development of Camallanus adamsi Bashirullah, 1974 (Nematoda: Camallanidae) in cyclopoid copepods

1976 ◽  
Vol 54 (12) ◽  
pp. 2055-2060 ◽  
Author(s):  
A. K. M. Bashirullah ◽  
Benazir Ahmed
Keyword(s):  
Larval Development ◽  
Intermediate Hosts ◽  
Larval Stages ◽  
Mesocyclops Leuckarti

The larval development of Camallanus adamsi Bashirullah, 1974 was followed in intermediate hosts, Mesocyclops leuckarti (Claus) and Thermocyclops crassus (Fischer), which were kept at 24 °C and 27 °C (average). The nematode molted twice in the haemocoel of copepods. The first molt occurred 117 h after infection at 24 °C and the second molt after 249 h. At 27 °C, the first and the second molts occurred 72 and 168 h respectively after the infection. Three larval stages are described.

scholarly journals Cormorant pellets as a tool for the knowledge of parasite-intermediate host associations and nematode diversity in the environment

2019 ◽  
Vol 56 (4) ◽  
pp. 296-302 ◽  
Author(s):  
L. Garbin ◽  
J. I. Diaz ◽  
A. Morgenthaler ◽  
A. Millones ◽  
L. Kuba ◽  
...  
Keyword(s):  
Prey Item ◽  
Feeding Habits ◽  
Paratenic Host ◽  
Intermediate Hosts ◽  
Good Tool ◽  
Larval Stages ◽  
Nematode Diversity ◽  
Bird Colonies ◽  
Prey Items ◽  
Host Associations

SummaryAnisakids are usually acquired through the diet. Cormorant pellets are useful to detect both parasite larval stages, and prey items which could act as intermediate hosts in the environment. The current study provides information about the feeding habits of both birds and mammals, and the diversity of parasites circulating in the environment. The objective of the study was to identify Anisakidae larvae and prey items in pellets from the Imperial shag Phalacrocorax atriceps and the Red-legged cormorant P. gaimardi, suggesting possible parasite–prey associations. A total of 92 P. atriceps’ and 82 P. gaimardi’s pellets were collected from both Punta León, and Isla Elena bird colonies, respectively, during the period from 2006 to 2010. Pellets were preserved in ethanol and hard prey item remnants, and nematode larvae were studied using standard techniques. Prey item occurrence, nematode prevalence, and mean intensity were calculated. A correspondence analysis was performed to evaluate the larvae-prey association. Contracaecum spp., Pseudoterranova spp,, Anisakis spp., Terranova spp., and Hysterothylacium spp. third-stage larvae (L3) were identifi ed in pellets. Pseudoterranova spp. and Anisakis spp. L3 predominated in the environment of Punta León, whereas Contracaecum spp. and Hysterothylacium spp. L3 predominated in the Puerto Deseado area. The highest larvae-prey association was that of Contracaecum spp. L3 with Engraulis anchoita, followed by with Odontestes sp. in P. atriceps’ pellets. Contracaecum spp. L3 were significantly related to both sprats, Sprattus fueguensis and Ramnogaster arcuatta, in P. gaimardi’s pellets. It was verifi ed that E. anchovy is the main gateway of Contracaecum spp. L3 in P. atriceps. Odonthestes sp. might act as an intermediate/paratenic host of Contracaecum spp. L3 in the area. Both sprats might play a role as intermediate/paratenic hosts of C. australe, being the main gateway into P. gaimardi in the area. Thus, pellet analysis can be postulated as a good tool for indicating parasite-host associations between anisakids, and the prey items which act as intermediate hosts.

Sign in / Sign up

Export Citation Format

Share Document