scholarly journals The behavioral effects of antibiotic treatment on the snailBiomphalaria glabrata

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4171 ◽  
Author(s):  
Euan R.O. Allan ◽  
Michael S. Blouin
Keyword(s):  
Tissue Culture ◽  
Intermediate Host ◽  
Antibiotic Treatment ◽  
New World ◽  
Biomphalaria Glabrata ◽  
Behavioral Effects ◽  
Neglected Tropical Disease ◽  
Intermediate Hosts ◽  
And Control ◽  
Main Model

Schistosomiasis is a detrimental neglected tropical disease that is transmitted by Planorbid snails. Understanding the transmission and control of this disease requires an extensive understanding of these intermediate hosts, which is only achieved by the effective rearing and study of species such asBiomphalaria glabrata. This species is the intermediate host forSchistosoma mansoniin the New World, and is also the main model for studying schistosomes in mollusks. Antibiotics are used routinely inB. glabratatissue culture, and occasionally on live snails. Here we show that standard doses of three common antibiotics (penicillin, streptomycin and gentamicin) drastically diminish the activity of healthyB. glabrata, but that treated snails recover rapidly when placed in fresh water. Ampicillin treated snails did not show altered activity. We suggest that researchers keep these apparent toxicities in mind if a need for antibiotic treatment of live Planorbid snails arises.

The influence of second intermediate host species on the infectivity of metacercarial cysts of Echinoparyphium recurvatum

1999 ◽  
Vol 73 (2) ◽  
pp. 143-145 ◽  
Author(s):  
A.M. McCarthy
Keyword(s):  
Intermediate Host ◽  
Definitive Host ◽  
Host Species ◽  
Post Infection ◽  
Rana Temporaria ◽  
Biomphalaria Glabrata ◽  
Reproductive Status ◽  
Intermediate Hosts ◽  
Potential Influence ◽  
Second Intermediate Host

The potential influence of second intermediate host species on the infectivity of metacercarial cysts of Echinoparyphium recurvatum to the definitive host Anas platyrhynchos was examined experimentally. Echinoparyphium recurvatum metacercarial cysts were obtained from the following experimentally infected second intermediate hosts 14 days post expsoure to cercariae: Lymnaea peregra; Physa fontinalis; L. stagnalis;Planorbis planorbis; Biomphalaria glabrata; tadpoles of the amphibian Rana temporaria. Metacercarial cysts from each of these hosts were fed, in doses of 50 cysts per individual, to separate groups composed of between four and eight, 3-day-old A. platyrhynchos ducklings. All A. platyrhynchos were necropsied 15 days post-infection and the number, size, and reproductive status of E. recurvatum worms in the intestine was recorded. Analyses of variance on the number (transformed log (x + 1)) and size of worms revealed no significant differences in worms originating from metacercariae formed in the different second intermediate hosts (worm number P > 0.05, and worm size P > 0.05). All worms recovered were found to be gravid. It is therefore concluded that the species of second intermediate host utilized does not influence the infectivity of the metacercarial cyst of E. recurvatum, nor the subsequent establishment and reproductive status of the parasite in A. platyrhynchos.

Levels of infection with the lungworm Angiostrongylus cantonensis in terrestrial snails from Thailand, with Cryptozona siamensis as a new intermediate host

2016 ◽  
Vol 90 (6) ◽  
pp. 737-741 ◽  
Author(s):  
A. Vitta ◽  
W. Polsut ◽  
C. Fukruksa ◽  
T. Yimthin ◽  
A. Thanwisai ◽  
...  
Keyword(s):  
Intermediate Host ◽  
Infectious Agent ◽  
Angiostrongylus Cantonensis ◽  
Intermediate Hosts ◽  
Worldwide Distribution ◽  
Artificial Digestion ◽  
Terrestrial Snails ◽  
Coi Sequences ◽  
Low Prevalence ◽  
And Control

AbstractAngiostrongylus cantonensis is primarily considered an emerging infectious agent of eosinophilic meningitis or meningoencephalitis with a worldwide distribution. Rodents and snails are important invasive hosts for transmission and expansion of A. cantonensis. The objective of this study was to investigate infection levels of A. cantonensis in snails, the most important natural intermediate host. Our study location was Mueang Kamphaeng Phet district, Kamphaeng Phet Province, and was undertaken between October and December 2012. A total of 2228 freshwater and terrestrial snails were collected, comprising 1119 Filopaludina spp., 409 Pomacea caniculata, 275 Achatina fulica and 425 Cryptozona siamensis. Angiostrongylus larvae were isolated by artificial digestion methods following Baermann's techniques. A low prevalence and intensity of A. cantonensis were observed in A. fulica, while higher numbers were found in C. siamensis. None of the Filopaludina spp. and Pomacea caniculata were infected with A. cantonensis. Molecular characterization was performed by analysing the 264 bp of cytochrome c oxidase subunit I (COI). Three COI sequences of Angiostrongylus were identical to A. cantonensis with 91–99% identity. Cryptozona siamensis has not previously been recorded as an intermediate host for A. cantonensis in Thailand. The infection of A. cantonensis identified in the natural intermediate hosts is new and important information to assist in the prevention and control of human angiostrongyliasis.

scholarly journals The dysbiosis of ovine foot microbiome during the development and treatment of contagious ovine digital dermatitis

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
J. S. Duncan ◽  
J. W. Angell ◽  
P. Richards ◽  
L. Lenzi ◽  
G. J. Staton ◽  
...  
Keyword(s):  
Antibiotic Treatment ◽  
Amplicon Sequencing ◽  
Strong Tendency ◽  
Rrna Gene ◽  
Digital Dermatitis ◽  
Healthy State ◽  
Foot Disease ◽  
End Stage ◽  
And Control ◽  
Interdigital Dermatitis

Abstract Background Contagious Ovine Digital Dermatitis (CODD) is an emerging and common infectious foot disease of sheep which causes severe welfare and economic problems for the sheep industry. The aetiology of the disease is not fully understood and control of the disease is problematic. The aim of this study was to investigate the polybacterial aetiopathogenesis of CODD and the effects of antibiotic treatment, in a longitudinal study of an experimentally induced disease outbreak using a 16S rRNA gene amplicon sequencing approach. Results CODD was induced in 15/30 experimental sheep. During the development of CODD three distinct phenotypic lesion stages were observed. These were an initial interdigital dermatitis (ID) lesion, followed by a footrot (FR) lesion, then finally a CODD lesion. Distinct microbiota were observed for each lesion in terms of microbial diversity, clustering and composition. Porphyromonadaceae, Family XI, Veillonellaceae and Fusobacteriaceae were significantly associated with the diseased feet. Veillonellaceae and Fusobacteriaceae were most associated with the earlier stages of ID and footrot rather than CODD. Following antibiotic treatment of the sheep, the foot microbiota showed a strong tendency to return to the composition of the healthy state. The microbiota composition of CODD lesions collected by swab and biopsy methods were different. In particular, the Spirochaetaceae family were more abundant in samples collected by the biopsy method, suggesting that these bacteria are present in deeper tissues of the diseased foot. Conclusion In this study, CODD presented as part of a spectrum of poly-bacterial foot disease strongly associated with bacterial families Porphyromonadaceae, Family XI (a family in Clostridiales also known as Clostridium cluster XI), Veillonellaceae and Fusobacteriaceae which are predominately Gram-negative anaerobes. Following antibiotic treatment, the microbiome showed a strong tendency to return to the composition of the healthy state. The composition of the healthy foot microbiome does not influence susceptibility to CODD. Based on the data presented here and that CODD appears to be the severest end stage of sheep infectious foot disease lesions, better control of the initial ID and FR lesions would enable better control of CODD and enable better animal welfare.

scholarly journals Serum C-reactive protein and WBC count in conservatively and operatively managed bacterial spondylodiscitis

2020 ◽  
Vol 29 (1) ◽  
pp. 230949902096829
Author(s):  
Christina van Gerven ◽  
Kevin Eid ◽  
Tobias Krüger ◽  
Michael Fell ◽  
Daniel Kendoff ◽  
...  
Keyword(s):  
Antibiotic Treatment ◽  
Serum Levels ◽  
Blood Chemistry ◽  
Nonoperative Treatment ◽  
C Reactive Protein ◽  
Disc Disease ◽  
Reactive Protein ◽  
Postoperative Serum ◽  
Wbc Count ◽  
And Control

Purpose: C-reactive protein (CRP) and white blood cell (WBC) count are routine blood chemistry parameters in monitoring infection. Little is known about the natural history of their serum levels in conservative and operative spondylodiscitis treatment. Methods: Pre- and postoperative serum levels of CRP and WBC count in 145 patients with spondylodiscitis were retrospectively assessed. One hundred and four patients were treated by debridement, spondylodesis, and an antibiotic regime, 41 only with a brace and antibiotics. The results of the surgical group were compared to 156 patients fused for degenerative disc disease (DDD). Results: Surgery had a significant effect on peak postoperative CRP levels. In surgically managed patients, CRP peaked at 2–3 days after surgery (spondylodiscitis: pre-OP: 90 mg/dl vs. post-OP days 2–3: 146 mg/dl; DDD: 9 mg/dl vs. 141 mg/dl; p < 0.001), followed by a sharp decline. Although values were higher for spondylodiscitis patients, dynamics of CRP values were similar in both groups. Nonoperative treatment showed a slower decline. Surgically managed spondylodiscitis showed a higher success rate in identifying bacteria. Specific antibiotic treatment led to a more predictable decline of CRP values. WBC did not show an interpretable profile. Conclusion: CRP is a predictable serum parameter in patients with spondylodiscitis. WBC count is unspecific. Initial CRP increase after surgery is of little value in monitoring infection. A preoperative CRP value, and control once during the first 3 days after surgery is sufficient. Closer monitoring should then be continued. Should a decline not be observed, therapy needs to be scrutinized, antibiotic treatment reassessed, and concomitant infection contemplated.

scholarly journals Domestication of wild animals may provide a springboard for rapid variation of coronavirus

2021 ◽  
Vol 16 (1) ◽  
pp. 252-254
Author(s):  
Lei Gao
Keyword(s):  
Intermediate Host ◽  
Wild Animals ◽  
Intermediate Hosts ◽  
Natural Conditions ◽  
Rapid Variation ◽  
Cross Breeding ◽  
Important Direction ◽  
Animal Hosts

Abstract Coronaviruses have spread widely among humans and other animals, but not all coronaviruses carried by specific animals can directly infect other kinds of animals. Viruses from most animal hosts need an intermediate host before they can spread widely among humans. Under natural conditions, coronaviruses do not rapidly change from infecting wild animals as intermediate hosts and to spreading widely among humans. The intermediate host might be the animals captured or bred for the purpose of cross-breeding with domesticated species for improvement of the breed. These animals differ from wild animals at the environmental and genetic levels. It is an important direction to study the semi-wild animals domesticated by humans in search for intermediate hosts of viruses widely spread among humans.

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.

scholarly journals Activities of naphthoquinones against Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae), vector of dengue and Biomphalaria glabrata (Say, 1818), intermediate host of Schistosoma mansoni

Acta Tropica ◽  
2009 ◽  
Vol 111 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Karlos A.L. Ribeiro ◽  
Cenira Monteiro de Carvalho ◽  
Maria Teresa Molina ◽  
Estelita Pereira Lima ◽  
Eulogio López-Montero ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Schistosoma Mansoni ◽  
Intermediate Host ◽  
Biomphalaria Glabrata

scholarly journals Severe acute respiratory syndrome (SARS) related coronavirus in bats

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Rong Geng ◽  
Peng Zhou
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Current Knowledge ◽  
Disease Outbreaks ◽  
First Century ◽  
Intermediate Hosts ◽  
Human Coronavirus ◽  
Transmission Potential ◽  
Disease Agent ◽  
And Control ◽  
Genomic Similarity

AbstractThree major human coronavirus disease outbreaks, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and 2019 coronavirus disease (COVID-19), occurred in the twenty-first century and were caused by different coronaviruses (CoVs). All these viruses are considered to have originated from bats and transmitted to humans through intermediate hosts. SARS-CoV-1 and SARS-CoV-2, disease agent of COVID-19, shared around 80% genomic similarity, and thus belong to SARS-related CoVs. As a natural reservoir of viruses, bats harbor numerous other SARS-related CoVs that could potentially infect humans around the world, causing SARS or COVID-19 like outbreaks in the future. In this review, we summarized the current knowledge of CoVs on geographical distribution, genetic diversity, cross-species transmission potential and possible pathogenesis in humans, aiming for a better understanding of bat SARS-related CoVs in the context of prevention and control.

Costs of intraspecific and interspecific host sharing in acanthocephalan cystacanths

Parasitology ◽  
2001 ◽  
Vol 122 (4) ◽  
pp. 483-489 ◽  
Author(s):  
B. S. DEZFULI ◽  
L. GIARI ◽  
R. POULIN
Keyword(s):  
Intermediate Host ◽  
Definitive Host ◽  
Interspecific Interactions ◽  
Sympatric Species ◽  
Competitive Interactions ◽  
Host Size ◽  
Intermediate Hosts ◽  
Transmission Success ◽  
Additional Costs ◽  
Net Benefits

Larval helminths often share individual intermediate hosts with other larval worms of the same or different species. In the case of immature acanthocephalans capable of altering the phenotype of their intermediate hosts, the benefits or costs of host sharing can be evaluated in terms of increased or decreased probability of transmission to a suitable definitive host. Competitive interactions among the immature stages of acanthocephalans within the intermediate host could create additional costs of host sharing, however. The effects of intraspecific and interspecific interactions were measured in 3 sympatric species of acanthocephalans exploiting a population of the amphipod Echinogammarus stammeri in the River Brenta, Italy. The strength of interactions was assessed from differences in the size achieved by infective cystacanths in the intermediate host. The size of Pomphorhynchus laevis cystacanths was not correlated with host size, whereas the size of Acanthocephalus clavula and Polymorphus minutus cystacanths increased with host size. Reductions in cystacanth size caused by intraspecific competition were only detected in P. laevis, but may also occur in both A. clavula and P. minutus. When co-occurring in the same amphipod with cystacanths of A. clavula, cystacanths of P. laevis attained a smaller size than when they occurred on their own. This effect was not reciprocal, with the size of A. clavula cystacanths not being affected. This supports earlier suggestions that it is adaptive for A. clavula to associate with P. laevis in amphipod intermediate hosts, with both species going to the same fish definitive hosts. In contrast, cystacanths of P. laevis achieved their largest size when they co-occurred in an amphipod with a cystacanth of P. minutus, which has a different definitive host (i.e. birds). These findings suggest that the net benefits of sharing an intermediate host can only be estimated by taking into account both the effects on transmission success and the consequences for cystacanth development.

scholarly journals Female biased sex-ratio in Schistosoma mansoni after exposure to an allopatric intermediate host strain of Biomphalaria glabrata

2013 ◽  
Vol 135 (2) ◽  
pp. 350-356 ◽  
Author(s):  
Julie M.J. Lepesant ◽  
Jérôme Boissier ◽  
Déborah Climent ◽  
Céline Cosseau ◽  
Christoph Grunau
Keyword(s):  
Sex Ratio ◽  
Schistosoma Mansoni ◽  
Intermediate Host ◽  
Biomphalaria Glabrata ◽  
Host Strain ◽  
Biased Sex Ratio
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