MyMedR

Displaying publications 81 - 100 of 148 in total

Abstract:

Sort:

Transcriptome analysis in the skin of Carassius auratus challenged with Aeromonas hydrophila

Wang R, Hu X, Lü A, Liu R, Sun J, Sung YY, et al.

Fish Shellfish Immunol, 2019 Nov;94:510-516.
PMID: 31541778 DOI: 10.1016/j.fsi.2019.09.039

Skin plays an important role in the innate immune responses of fish, particularly towards bacterial infection. To understand the molecular mechanism of mucosal immunity of fish during bacterial challenge, a de novo transcriptome assembly of crucian carp Carassius auratus skin upon Aeromonas hydrophila infection was performed, the latter with Illumina Hiseq 2000 platform. A total of 118111 unigenes were generated and of these, 9693 and 8580 genes were differentially expressed at 6 and 12 h post-infection, respectively. The validity of the transcriptome results of eleven representative genes was verified by quantitative real-time PCR (qRT-PCR) analysis. A comparison with the transcriptome profiling of zebrafish skin to A. hydrophila with regards to the mucosal immune responses revealed similarities in the complement system, chemokines, heat shock proteins and the acute-phase response. GO and KEGG enrichment pathway analyses displayed the significant immune responses included TLR, MAPK, JAK-STAT, phagosome and three infection-related pathways (ie., Salmonella, Vibrio cholerae and pathogenic Escherichia coli) in skin. To our knowledge, this study is the first to describe the transcriptome analysis of C. auratus skin during A. hydrophila infection. The outcome of this study contributed to the understanding of the mucosal defense mechanisms in cyprinid species.

Matched MeSH terms: Fish Diseases/immunology*
The Morphological and Molecular Description of Acanthogyrus (Acanthosentis) fusiformis n. sp. (Acanthocephala: Quadrigyridae) from the Catfish Arius sp. (Ariidae) in the Pacific Ocean off Vietnam, with Notes on Zoogeography

Amin OM, Chaudhary A, Heckmann RA, Ha NV, Singh HS

Acta Parasitol, 2019 Dec;64(4):779-796.
PMID: 31332657 DOI: 10.2478/s11686-019-00102-3

BACKGROUND: Most (82%) of the 46 recognized species of Acanthogyrus (Acanthosentis) Verma and Datta, 1929 are known from Asian freshwater fishes. Only three species of Acanthosentis are known from marine or brackish water fishes from India and Pakistan. We have discovered another marine species of Acanthosentis in the Pacific Ocean, off Vietnam.
PURPOSE: The purpose is to describe the new species morphologically and molecularly and provide new information of its evolutionally relationships with other species of the subgenus.
METHODS: Standard methods of collection and examination of marine hosts, processing and illustrating of specimens, and taxonomic identification of parasites using the extensive collection of the lead author were used. Specimens were further studied using energy-dispersive X-ray analysis and ion sectioning of hooks, SEM analysis, and molecular sequencing. Type specimens were deposited at the Harold W. Manter Lab. collection, Lincoln, Nebraska.
RESULTS: Acanthogyrus (Acanthosentis) fusiformis n. sp. is described from the catfish, Arius sp. (Ariidae: Siluriformes) off the Pacific Coast of Vietnam at Bac Lieu in the Gulf of Thailand. The three other marine Indian species include A. (A.) arii Bilqees, 1971 which is also described from a similar catfish, Arius serratus Day off the Karachi coast in the Arabian Sea, Indian Ocean. Our new species from Vietnam is distinguished from the other 46 species by a combination of characters including a small fusiform trunk, complete circles of small hollow spines covering the entire trunk, prominent double apical organs often extending posteriorly past posterior hooks, middle and posterior hooks of equal size slightly smaller than anterior hooks, large neck continuous with the outline of the proboscis without distinct separation, big drop-shaped cephalic ganglion, extension of the proboscis receptacle anteriorly past the base of the proboscis up to the insertion point of the posterior hooks, presence of two para-receptacle structures (PRSs), free unattached thick lemnisci, short female reproductive system with filamentous attachment of the distal end of the uterine bell to the ventral body wall, and small narrowly ellipsoid eggs with thickened polar ends. Partial sequences of the 18S and internal transcribed spacers (ITS1-5.8S-ITS2) of ribosomal RNA were generated and used for phylogenetic analyses to confirm the taxonomic identity of Acanthogyrus (Acanthosentis) fusiformis n. sp.
CONCLUSIONS: We describe unique morphological features of A. fusiformis never before known in the subgenus Acanthosentis. The uniqueness of A. fusiformis is further demonstrated by its EDXA fingerprint characterized by high levels of calcium and phosphorous in hooks. The zoogeography of species of Acanthosentis is elucidated in the Indian subcontinent, the Caribbean, China, and Africa. Molecular data have been available only in few species of Acanthogyrus (Acanthosentis) to date on GenBank database. For 18S, only two sequences from unknown Acanthosentis sp. from India are available, while for the ITS1-5.8S-ITS2 region, only sequences of A. cheni from China and of two unidentified species from Malaysia are available. Additional studies of species of Acanthosentis based on morphological and molecular genetic data will be needed to reconstruct the evolutionary history and phylogenetic affinities of this group of acanthocephalans.

Matched MeSH terms: Fish Diseases/parasitology*
Environmental Factors Associated with the Presence of Vibrionaceae in Tropical Cage-Cultured Marine Fishes

Mohamad N, Mustafa M, Amal MNA, Saad MZ, Md Yasin IS, Al-Saari N

J Aquat Anim Health, 2019 06;31(2):154-167.
PMID: 30653742 DOI: 10.1002/aah.10062

This study investigated the environmental factors associated with the presence of Vibrionaceae in economically important cage-cultured tropical marine fishes: the Asian Seabass Lates calcarifer, snapper Lutjanus sp., and hybrid grouper Epinephelus sp. Fish sampling was conducted at monthly intervals between December 2016 and August 2017. The body weight and length of individual fish were measured, and the skin, eye, liver, and kidney were sampled for bacterial isolation and identification. Water physicochemical parameters during the sampling activities were determined, and the enumeration of total Vibrionaceae count was also conducted from water and sediment samples. Nine species of Vibrio were identified, including V. alginolyticus, V. diabolicus, V. harveyi, V. campbellii, V. parahaemolyticus, V. rotiferianus, V. furnissii, V. fluvialis, and V. vulnificus. Photobacterium damselae subsp. damselae was also identified. A total of 73% of the isolated Vibrio belonged to the Harveyi clade, followed by the Vulnificus clade (5.5%) and Cholera clade (0.6%). Highest occurrence of Vibrio spp. and P. damselae subsp. damselae was found in hybrid grouper (72%), followed by Asian Seabass (48%) and snapper (36%). The associations of Vibrio spp. and P. damselae subsp. damselae with the host fish were not species specific. However, fish mortality and fish size showed strong associations with the presence of some Vibrio spp. On average, 60% of the infected cultured fish exhibited at least one clinical sign. Nevertheless, inconsistent associations were observed between the pathogens and water quality. The yearlong occurrence and abundance of Vibrionaceae in the environmental components indicate that they might serve as reservoirs of these pathogens.

Matched MeSH terms: Fish Diseases/microbiology*
Preliminary characterization of Tasmanian aquareovirus (TSRV) isolates

Zainathan SC, Carson J, Crane MS, Williams LM, Hoad J, Moody NJ, et al.

Arch Virol, 2017 03;162(3):625-634.
PMID: 27807656 DOI: 10.1007/s00705-016-3132-0

In an attempt to determine whether or not genetic variants of the Tasmanian strain of Atlantic salmon aquareovirus (TSRV) exist, 14 isolates of TSRV, originating from various locations in Tasmania, covering a 20-year period (1990-2010), obtained from various host species and tissues, and isolated on different cell lines, were selected for this study. Two categories, termed "typical" and "atypical", of variants of TSRV were identified based on preliminary genotypic and phenotypic characterization carried out on these 14 different isolates. In addition, electron microscopic examination indicated the existence of at least three variants based on viral particle size. Finally, this study demonstrated the existence of at least one new variant of TSRV isolates, other than the more commonly isolated typical TSRV isolates, in farmed Tasmanian Atlantic salmon.

Matched MeSH terms: Fish Diseases/virology*
First Report of Achlya oblongata Infection in Freshwater-Reared Asian Seabass Lates calcarifer

Lau LM, Hatai K, Fukano H, Kurata O

J Aquat Anim Health, 2018 12;30(4):239-244.
PMID: 29710400 DOI: 10.1002/aah.10018

In September 2014, a freshwater oomycete was first isolated from Asian Seabass Lates calcarifer fry that were reared in freshwater at a fish hatchery in Sabah, Malaysia. A fungal strain was isolated from infected fry by using glucose yeast extract (GY) agar. From morphological identification, the strain belonged to the genus Achlya based on the mode of zoospore release. Molecular phylogenetic analysis of the internal transcribed spacer region sequences from the strain showed high similarity (99-100%) to Achlya oblongata. The isolate was able to grow on GY agar incubated at 15-35°C, in GY broth adjusted to pH 3.0-11.0, and in up to 1.0% NaCl. This is the first report of Achlya infection in freshwater-reared Asian Seabass in Malaysia.

Matched MeSH terms: Fish Diseases/microbiology*
Synergistic effects of dietary supplementation of Bacillus subtilis WB60 and mannanoligosaccharide (MOS) on growth performance, immunity and disease resistance in Japanese eel, Anguilla japonica

Lee S, Katya K, Hamidoghli A, Hong J, Kim DJ, Bai SC

Fish Shellfish Immunol, 2018 Dec;83:283-291.
PMID: 30217508 DOI: 10.1016/j.fsi.2018.09.031

This study evaluated the synergistic effects of dietary Bacillus subtilis WB60 and mannanoligosaccharide (MOS) in juvenile Japanese eel, Anguilla japonica. Seven treatment diets were formulated to contain three different levels of B. subtilis (0.0, 0.5, and 1.0 × 107 CFU/g diet denoted as BS0, BS0.5, and BS1, respectively) with two MOS levels (0 and 5 g/kg diet denoted as M0 and M5, respectively), and one diet with oxytetracycline (OTC) at 5 g/kg diet. Each diet (BS0M0 (CON), BS0M5, BS0.5M0, BS0.5M5, BS1M0, BS1M5, and OTC) was fed to triplicate groups of 20 fish averaging 9.00 ± 0.11 g (mean ± SD) for eight weeks. Average weight gain, feed efficiency, specific growth rate and protein efficiency ratio of fish fed the BS0.5M5 and BS1M5 diets were significantly higher than those of fish fed CON, BS0.5M0 and OTC diets (P fish fed the BS0.5M5, BS1M5, and OTC diets compared to the CON, BS0.5M0, and BS0M5 diets (P fish fed the BS0.5M5 and BS1M5 diets compared to those of fish fed the other diets (P fish fed BS0.5M5 and BS1M5 diets were significantly higher than those of fish fed the CON diet (P fish fed BS0.5M5 and BS1M5 diets than those fed CON, BS0M5, and OTC diets. Additionally, resistance to bacterial challenge with Vibrio anguillarum was recorded significantly lower for fish fed the CON diet than those fed other diets (P > 0.05). Therefore, the results for growth performance, non-specific immune responses, intestinal morphology, and disease resistance demonstrated that supplementation of B. subtilis at 0.5 × 107 CFU/g diet and mannanoligosaccharide at 5 g/kg diet could have beneficial synergistic effects in Japanese eel. The isolated probiotic from eel and the selected prebiotic could lead to the development of a specific and potential synbiotic in Japanese eel aquaculture.

Matched MeSH terms: Fish Diseases/immunology
Fulltext Virulence-associated genes and antibiotic resistance patterns of Vibrio spp. isolated from cultured marine fishes in Malaysia

Mohamad N, Amal MNA, Saad MZ, Yasin ISM, Zulkiply NA, Mustafa M, et al.

BMC Vet Res, 2019 May 28;15(1):176.
PMID: 31138199 DOI: 10.1186/s12917-019-1907-8

BACKGROUND: Vibriosis is an important bacterial disease of cultured marine fishes worldwide. However, information on the virulence and antibiotic resistance of Vibrio spp. isolated from fish are scarce. This study investigates the distribution of virulence associated genes and antibiotic resistance patterns of Vibrio spp. isolated from cage-cultured marine fishes in Malaysia.
RESULTS: A total of 63 Vibrio spp. isolated from 62 cultured marine fishes in various geographical regions in Peninsular Malaysia were analysed. Forty-two of the isolates (66.7%) were positive for all chiA, luxR and vhpA, the virulence genes produced by pathogenic V. harveyi. A total of 62 Vibrio isolates (98%) had tlh gene of V. parahaemolyticus, while flaC gene of V. anguillarum was detected in 43 of isolates (68%). Other virulence genes, including tdh, trh, hlyA and toxRvc were absent from any of the isolates. Multiple antibiotic resistance (MAR) was exhibited in all strains of Harveyi clade, particularly against ampicillin, penicillin, polypeptides, cephems and streptomycin. The MAR index ranged between 0.06 and 0.56, and 75% of the isolates have MAR index of higher than 0.20. Host species and geographical origin showed no correlation with the presence of virulence genes and the antibiotic resistance patterns of Vibrio spp.
CONCLUSIONS: The study indicates that majority of Vibrio spp. isolated from cultured marine fishes possess virulence genes, but were not associated with human pathogen. However, the antibiotics resistance is a real concern and warrants ongoing surveillance. These findings represent an updated knowledge on the risk of Vibrio spp. to human health, and also provides valuable insight on alternative approaches to combat vibriosis in cultured fish.

Matched MeSH terms: Fish Diseases/microbiology*
Quorum sensing is required for full virulence of Vibrio campbellii towards tiger grouper (Epinephelus fuscoguttatus) larvae

Noor NM, Defoirdt T, Alipiah N, Karim M, Daud H, Natrah I

J Fish Dis, 2019 Apr;42(4):489-495.
PMID: 30742313 DOI: 10.1111/jfd.12946

The link between quorum sensing in Vibrio campbellii and its virulence towards tiger grouper (Epinephelus fuscoguttatus) was investigated using V. campbellii wild type and quorum-sensing mutants with inactive quorum sensing or constitutively maximal quorum-sensing activity, and signal molecule synthase mutants. The results showed that wild-type V. campbellii is pathogenic to grouper larvae, causing more than 50% mortality after 4 days of challenge. Furthermore, the mortality of larvae challenged with the mutant with maximally active quorum sensing was significantly higher than that of larvae challenged with the wild type, whereas a higher survival was observed in the larvae challenged to the mutant with a completely inactive quorum-sensing system. Grouper larvae challenged with either the signal molecule synthase triple mutant, the harveyi autoinducer-1 (HAI-1) synthase mutant and the autoinducer-2 (AI-2) synthase mutant showed higher survival than larvae challenged with the wild type. In contrast, larvae challenged with the cholerae autoinducer-1 (CAI-1) synthase mutant showed high mortality. This indicates that HAI-1 and AI-2, but not CAI-1, are required for full virulence of V. campbellii towards grouper larvae. Our data suggest that quorum-sensing inhibition could be an effective strategy to control V. campbellii infections in tiger grouper.

Matched MeSH terms: Fish Diseases/microbiology*
Fish-borne trematode metacercariae detected in fish commonly used for raw consumption in Ninh Binh Province, Vietnam

Khoa DV, Hoa DT, Anh DN, Van NT, Dung DT, Huong LTT, et al.

Trop Biomed, 2020 Jun 01;37(2):443-451.
PMID: 33612813

Raw or undercooked fish dishes are the major sources of human infection of fishborne trematodes (FBT) and the situation of metacercarial infection in fish greatly affect the prevalence in humans, especially those fish that are commonly used for raw consumption. To investigate the situation of infection with metacercaria of FBT in fish often used to prepare raw fish dishes by local people to assess the risk of infection to humans in Ninh Binh province, Vietnam. 345 fish belonging to five species of freshwater and one species of brackish water fish were collected from fishermen or small-scale fish dealers in Kim Son and Yen Khanh districts, Ninh Binh province between May 2017 and May 2018. Metacercaria of FBT was discovered by pepsin and hydrochloric acid digestion techniques and identified by the morphological and molecular analysis. Among examined fish, 44.06% infected with FBT metacercaria and the highest prevalence was in Cyprinus carpio (86.54%), Ctenopharyngodon idellus (78.43%) and Hypophthalmichthys molitrix (66.67%) while Konosirus punctatus - the brackish water fish - were free from infection. Three species of FBT were found; namely Haplorchis pumilio (accounting for 99.84% of collected metacercariae), Haplorchis taichui and Clonorchis sinensis. The average density was 1.06 metacercariae per gram of freshwater fish and the highest number was of C. idellus (6.38 cysts/gram) followed by Cirrhinus molitorella and C. carpio. Results of the study show the high prevalence of infection of FBT metacercariae among freshwater fish often used to prepare raw fish dishes in Ninh Binh province. These findings suggest the need for greater awareness of the risk from raw fish dishes among public health authorities and people.

Matched MeSH terms: Fish Diseases/parasitology*
Fulltext Gut Immune System and the Implications of Oral-Administered Immunoprophylaxis in Finfish Aquaculture

Lee PT, Yamamoto FY, Low CF, Loh JY, Chong CM

Front Immunol, 2021;12:773193.
PMID: 34975860 DOI: 10.3389/fimmu.2021.773193

The gastrointestinal immune system plays an important role in immune homeostasis regulation. It regulates the symbiotic host-microbiome interactions by training and developing the host's innate and adaptive immunity. This interaction plays a vital role in host defence mechanisms and at the same time, balancing the endogenous perturbations of the host immune homeostasis. The fish gastrointestinal immune system is armed with intricate diffused gut-associated lymphoid tissues (GALTs) that establish tolerance toward the enormous commensal gut microbiome while preserving immune responses against the intrusion of enteric pathogens. A comprehensive understanding of the intestinal immune system is a prerequisite for developing an oral vaccine and immunostimulants in aquaculture, particularly in cultured fish species. In this review, we outline the remarkable features of gut immunity and the essential components of gut-associated lymphoid tissue. The mechanistic principles underlying the antigen absorption and uptake through the intestinal epithelial, and the subsequent immune activation through a series of molecular events are reviewed. The emphasis is on the significance of gut immunity in oral administration of immunoprophylactics, and the different potential adjuvants that circumvent intestinal immune tolerance. Comprehension of the intestinal immune system is pivotal for developing effective fish vaccines that can be delivered orally, which is less labour-intensive and could improve fish health and facilitate disease management in the aquaculture industry.

Matched MeSH terms: Fish Diseases/prevention & control*
Effect of dietary prebiotics and probiotics on snakehead (Channa striata) health: Haematology and disease resistance parameters against Aeromonas hydrophila

Munir MB, Hashim R, Nor SAM, Marsh TL

Fish Shellfish Immunol, 2018 Apr;75:99-108.
PMID: 29407616 DOI: 10.1016/j.fsi.2018.02.005

This study examined the effect of dietary prebiotics and probiotics after 16 weeks, followed by 8 weeks of post feeding trial with the control unsupplemented diet on haematological and immune response against Aeromonas hydrophila infection in Channa striata fingerlings. Fish were raised on a 40% protein and 12% lipid feed containing three commercial prebiotics (β-glucan, GOS or galacto-oligosaccharide, MOS or mannan-oligosaccharide); and two probiotics- (Saccharomyces cerevisiae, Lactobacillus acidophilus), respectively and a control. Throughout the study, supplementation with dietary prebiotics and probiotics led to significant (P fish were challenged with Aeromonas hydrophila at the dose of 2 × 106. The disease resistance against A. hydrophila was higher significantly (P fish fed with probiotic feed supplements (L.acidophilus was highest) compared to prebiotics and control. The study is the first to report the absence of differences in sustaining the efficacies attained after intake of β-glucan, GOS and MOS upon post-feeding with an unsupplemented feed, over a prolonged period.

Matched MeSH terms: Fish Diseases/immunology*
Whole-Genome Sequencing of Pseudomonas koreensis Isolated from Diseased Tor tambroides

Kho CJY, Lau MML, Chung HH, Chew IYY, Gan HM

Curr Microbiol, 2023 Jun 25;80(8):255.
PMID: 37356021 DOI: 10.1007/s00284-023-03354-5

Unlike environmental P. koreensis isolated from soil, which has been studied extensively for its role in promoting plant growth, pathogenic P. koreensis isolated from fish has been rarely reported. Therefore, we investigated and isolated the possible pathogen that is responsible for the diseased state of Tor tambroides. Herein, we reported the morphological and biochemical characteristics, as well as whole-genome sequences of a newly identified P. koreensis strain. We assembled a high-quality draft genome of P. koreensis CM-01 with a contig N50 value of 233,601 bp and 99.5% BUSCO completeness. The genome assembly of P. koreensis CM-01 is consists of 6,171,880 bp with a G+C content of 60.5%. Annotation of the genome identified 5538 protein-coding genes, 3 rRNA genes, 54 tRNAs, and no plasmids were found. Besides these, 39 interspersed repeat and 141 tandem repeat sequences, 6 prophages, 51 genomic islands, 94 insertion sequences, 4 clustered regularly interspaced short palindromic repeats, 5 antibiotic-resistant genes, and 150 virulence genes were also predicted in the P. koreensis CM-01 genome. Culture-based approach showed that CM-01 strain exhibited resistance against ampicillin, aztreonam, clindamycin, and cefoxitin with a calculated multiple antibiotic resistance (MAR) index value of 0.4. In addition, the assembled CM-01 genome was successfully annotated against the Cluster of Orthologous Groups of proteins database, Gene Ontology database, and Kyoto Encyclopedia of Genes and Genome pathway database. A comparative analysis of CM-01 with three representative strains of P. koreensis revealed that 92% of orthologous clusters were conserved among these four genomes, and only the CM-01 strain possesses unique elements related to pathogenicity and virulence. This study provides fundamental phenotypic and genomic information for the newly identified P. koreensis strain.

Matched MeSH terms: Fish Diseases/microbiology
Interaction of low-level dietary supplementation of Chlorella vulgaris Beijerinck, 1890, and feeding duration on growth hormone, growth performance and serum biochemistry of red hybrid tilapia (Oreochromis mossambicus × Oreochromis niloticus)

Ahmad MT, Shariff M, Goh YM, Banerjee S, Yusoff FM

J Fish Biol, 2023 Sep;103(3):715-726.
PMID: 37249562 DOI: 10.1111/jfb.15469

Chlorella is one of the most widely accepted Chlorophyta used by many as livestock and aquaculture feed. Nonetheless, different studies on the overall performances of fish reported the unfavourable effect of high-level supplementations of Chlorella vulgaris. The current study determined the impact of low-level dietary supplementation of C. vulgaris alongside the different feeding durations and their interactions on the growth hormone (GH), growth performances, serum-biochemical indices, hepatic function and some immunological parameters of red hybrid tilapia. The fingerlings (mean weight: 14.25 ± 0.01 g, length: 13.5 ± 0.49 cm) were fed diets containing 0, 0.99%, 2.91% and 4.76% of C. vulgaris powder per kilogram dry diet for 90 days. GH, growth performance, serum-biochemical indices (total serum protein, albumin, globulin, glucose, aspartate aminotransferase and alanine aminotransferase) and some immunological (respiratory burst and lysozyme activities) parameters of the fish were examined after 30, 60 and 90 days of feeding. The results demonstrated that tilapia fed C. vulgaris-supplemented diets showed increased levels of respiratory burst, lysozyme, albumin and total protein, GH and growth performances (P fish. Besides, low survivability was observed in the control group than in the group fed the experimental diets. The group fed the diet supplemented with 4.76% C. vulgaris had significantly higher (P

Matched MeSH terms: Fish Diseases*
Fulltext Histozoic myxosporeans infecting the stomach wall of elopiform fishes represent a novel lineage, the Gastromyxidae

Freeman MA, Kristmundsson Á

Parasit Vectors, 2015;8:517.
PMID: 26453151 DOI: 10.1186/s13071-015-1140-7

Traditional studies on myxosporeans have used myxospore morphology as the main criterion for identification and taxonomic classification, and it remains important as the fundamental diagnostic feature used to confirm myxosporean infections in fish and other vertebrate taxa. However, its use as the primary feature in systematics has led to numerous genera becoming polyphyletic in subsequent molecular phylogenetic analyses. It is now known that other features, such as the site and type of infection, can offer a higher degree of congruence with molecular data, albeit with its own inconsistencies, than basic myxospore morphology can reliably provide.

Matched MeSH terms: Fish Diseases/parasitology*
Teraplectanum n. g. (Monogenea: Diplectanidae) from the banded grunter fish, Terapon theraps Cuvier (Perciformes: Terapontidae), off Peninsular Malaysia

Lim LH

J Helminthol, 2015 May;89(3):307-16.
PMID: 24698519 DOI: 10.1017/S0022149X1400008X

A new genus of the Monogenea, Teraplectanum n. g., is proposed for two new species of diplectanids found on the gills of Terapon theraps Cuvier collected off Carey Island, Peninsular Malaysia. The genus is based on a unique arrangement of the male reproductive system. In the new species spermatozoa stored in the seminal vesicle and secretions stored in the prostatic reservoir are transferred into, and mixed to form semen within, a special sclerotized auxiliary piece (SAP), and not within the copulatory tube as occurs in the majority of monogeneans. Teraplectanum species also possess a unique sclerotized vaginal loop through which the vaginal tube passes en route from the vaginal pore to the seminal receptacle. The two new species are Teraplectanum crassitubus n. sp. (type species) and T. angustitubus n. sp. They differ from each other mainly in the morphology of their copulatory tube: in T. crassitubus, the proximal region of this tube is thicker compared to the slender proximal region in T. angustitubus, although in both cases the tube tapers and twists distally. Of the known diplectanid species, only Diplectanum undulicirrosum Zhang et al., 2000 (currently considered incertae sedis) possesses such sclerotized hard parts, which suggests the same type of arrangement of the male reproductive system. Consequently, D. undulicirrosum is re-assigned to this new genus as Teraplectanum undulicirrosum (Zhang et al., 2000) n. comb. The copulatory tube of T. undulicirrosum is similar to the slender, undulating copulatory tube of T. angustitubus but does not taper distally as in the latter species.

Matched MeSH terms: Fish Diseases/parasitology*
A description of two new species of Ligophorus Euzet & Suriano, (Monogenea: Ancyrocephalidae) from Malaysian mugilid fish using principal component analysis and numerical taxonomy

Soo OY, Lim LH

J Helminthol, 2015 Mar;89(2):131-49.
PMID: 24148150 DOI: 10.1017/S0022149X13000655

Ligophorus belanaki n. sp. and Ligophorus kederai n. sp. are described from Liza subviridis Valenciennes, 1836 and Valamugil buchanani Bleeker, 1854, respectively. Ligophorus kederai n. sp. has fenestrated ventral anchors, while in L. belanaki n. sp. the ventral anchor is not fenestrated. Ligophorus belanaki n. sp. is similar to L. careyensis, one of its coexisting congeners, in the overall shape and size of hard parts, but differs in having a flat median piece in the structure of the AMP (antero-median protuberance of the ventral bar), copulatory organ with non-ornamented initial part and longer vaginal tube, compared to raised median piece in the AMP, ornamented initial part and comparatively shorter vaginal tube in L. careyensis. Ligophorus kederai n. sp. is similar to L. fenestrum, a coexisting congener, in having fenestrated ventral anchors, but differs in having longer points and narrower base. Ligophorus fenestrum, unlike L. kederai n. sp., also possesses fenestrated dorsal anchors. The principal component analysis (PCA) scatterplots indicate that the two new and eight known Ligophorus species from Malaysian mugilids can be differentiated based on the morphometries of their anchors, ventral bars and copulatory organ separately and when combined together. Numerical taxonomy (NT) analyses based on Jaccard's Index of Similarity and neighbour-joining clustering, is used to facilitate comparison of these two new species with the 50 known Ligophorus based on morphological and metric characters. The two new species are different from each other and the other 50 species in the overall shapes and sizes of hard parts, as indicated by the NT analyses.

Matched MeSH terms: Fish Diseases/parasitology*
Fulltext Comparative study of the metal accumulation in Hysterothalycium reliquens (nematode) and Paraphilometroides nemipteri (nematode) as compared with their doubly infected host, Nemipterus peronii (Notched threadfin bream)

Mazhar R, Shazili NA, Harrison FS

Parasitol Res, 2014 Oct;113(10):3737-43.
PMID: 25115732 DOI: 10.1007/s00436-014-4039-x

In February 2013, forty-seven Notched threadfin bream, the Nemipterus peronii, were sampled from the eastern coastal waters of the South China Sea. The concentration of various elements, namely cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), strontium (Sr), manganese (Mn), selenium (Se), Lead (Pb), nickel (Ni), aluminum (Al), arsenic (As), iron (Fe), and Zinc (Zn) were analyzed in the liver, muscle, and kidney organs of the host, as well as in their parasites Hysterothalycium reliquens (nematode) and the Paraphilometroides nemipteri (nematode), using inductively coupled plasma mass spectrometry (ICP-MS). The former group of parasites showed highest accumulation capacity for Cr, Cu, Fe, Mn, Se, Ni, and Zn while the latter group had high accumulation potential of As, Hg, Cd, Al, Pb, and Sr. The divergence in heavy-metal accumulation profiles of both nematodes is linked with the specificity of microhabitats, cuticle morphology, and interspecific competition. The outcome of this study indicates that both parasite models can be used for biomonitoring of metal pollution in marine ecosystems.

Matched MeSH terms: Fish Diseases/metabolism; Fish Diseases/parasitology
Fulltext Occurrence and molecular identification of Anisakis Dujardin, 1845 from marine fish in southern Makassar Strait, Indonesia

Anshary H, Sriwulan, Freeman MA, Ogawa K

Korean J Parasitol, 2014 Feb;52(1):9-19.
PMID: 24623876 DOI: 10.3347/kjp.2014.52.1.9

Anisakis spp. (Nematoda: Anisakidae) parasitize a wide range of marine animals, mammals serving as the definitive host and different fish species as intermediate or paratenic hosts. In this study, 18 fish species were investigated for Anisakis infection. Katsuwonus pelamis, Euthynnus affinis, Caranx sp., and Auxis thazard were infected with high prevalence of Anisakis type I, while Cephalopholis cyanostigma and Rastrelliger kanagurta revealed low prevalence. The mean intensity of Anisakis larvae in K. pelamis and A. thazard was 49.7 and 5.6, respectively. A total of 73 Anisakis type I larvae collected from K. pelamis and A. thazard were all identified as Anisakis typica by PCR-RFLP analysis. Five specimens of Anisakis from K. pelamis and 15 specimens from A. thazard were sequenced using ITS1-5.8S-ITS2 region and 6 specimens from A. thazard and 4 specimens from K. pelamis were sequenced in mtDNA cox2 region. Alignments of the samples in the ITS region showed 2 patterns of nucleotides. The first pattern (genotype) of Anisakis from A. thazard had 100% similarity with adult A. typica from dolphins from USA, whereas the second genotype from A. thazard and K. pelamis had 4 base pairs different in ITS1 region with adult A. typica from USA. In the mtDNA cox2 regions, Anisakis type I specimens from A. thazard and K. pelamis showed similarity range from 94% to 99% with A. typica AB517571/DQ116427. The difference of 4 bp nucleotides in ITS1 regions and divergence into 2 subgroups in mtDNA cox2 indicating the existence of A. typica sibling species in the Makassar Strait.

Matched MeSH terms: Fish Diseases/epidemiology*; Fish Diseases/parasitology*
Development and efficacy of feed-based recombinant vaccine encoding the cell wall surface anchor family protein of Streptococcus agalactiae against streptococcosis in Oreochromis sp

Nur-Nazifah M, Sabri MY, Siti-Zahrah A

Fish Shellfish Immunol, 2014 Mar;37(1):193-200.
PMID: 24486904 DOI: 10.1016/j.fsi.2014.01.011

This study was carried out to determine the antibody responses and protective capacity of an inactivated recombinant vaccine expressing the cell wall surface anchor family protein of Streptococcus agalactiae following oral vaccination against streptococcosis in tilapia. Tilapia were vaccinated orally with 10(6) CFU/mL of the recombinant vaccine incorporated in feed (feed-based recombinant vaccine) (vaccinated group or Group 1), 10(6) CFU/mL of pET-32 Ek/LIC vector without cell wall surface anchor family protein (control group or Group 2), 10(6) CFU/mL of formalin-killed cells of S. agalactiae vaccine incorporated in feed was also prepared (feed-based vaccine) (vaccinated group or Group 3), and unvaccinated control group or Group 4 (fed with commercial pellets). During the course of study, serum, mucus and gut lavage fluid were collected to evaluate the antibody levels via enzyme-linked immunosorbent assay (ELISA). The results showed that tilapia immunized with the feed-based recombinant vaccine developed a strong and significantly (P

Matched MeSH terms: Fish Diseases/microbiology*; Fish Diseases/prevention & control*
Cryptocaryon irritans infection induces the acute phase response in Lates calcarifer: a transcriptomic perspective

Khoo CK, Abdul-Murad AM, Kua BC, Mohd-Adnan A

Fish Shellfish Immunol, 2012 Oct;33(4):788-94.
PMID: 22842150 DOI: 10.1016/j.fsi.2012.07.005

Cryptocaryoniasis (also known as marine white spot disease) is mediated by Cryptocaryon irritans. This obligate ectoparasitic protozoan infects virtually all marine teleosts, which includes Lates calcarifer, a highly valuable aquaculture species. Little is known about L. calcarifer-C. irritans interactions. This study was undertaken to gain an informative snapshot of the L. calcarifer transcriptomic response over the course of C. irritans infection. An in-house fabricated cDNA microarray slides containing 3872 probes from L. calcarifer liver and spleen cDNA libraries were used as a tool to investigate the response of L. calcarifer to C. irritans infection. Juvenile fish were infected with parasites for four days, and total RNA was extracted from liver tissue, which was harvested daily. We compared the transcriptomes of C. irritans-infected liver to uninfected liver over an infection period of four days; the comparison was used to identify the genes with altered expression levels in response to C. irritans infection. The greatest number of infection-modulated genes was recorded at 2 and 3 days post-infection. These genes were mainly associated with the immune response and were associated in particular with the acute phase response. Acute phase proteins such as hepcidin, C-type lectin and serum amyloid A are among the highly modulated genes. Our results indicate that an induced acute phase response in L. calcarifer toward C. irritans infection is similar to the responses observed in bacterial infections of teleosts. This response demonstrates the importance of first line defenses in teleost innate immune responses against ectoparasite infection.

Matched MeSH terms: Fish Diseases/immunology*; Fish Diseases/parasitology*

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links