Search

Ulcerative disease causes significant economic losses in largemouth bass Micropterus salmoides production. Yet information reported on Bacillus mycoides as a pathogen for largemouth bass is scarce. In this study, a virulent strain, temporarily named LYS1, was isolated from diseased M. salmoides suffering from ulcerative disease, identified phenotypically and molecularly as B. mycoides. A phylogenetic tree was constructed to examine isolate LYS1 and compare it to other known isolates. In addition, isolate LYS1 appears to be susceptible to aminoglycosides and quinolones drugs for veterinary use in aquaculture as seen when screened against a range of common antibiotics. To the best of our knowledge, this is the first report of B. mycoides as a pathogen of ulcerative disease in farmed largemouth bass. [ABSTRACT FROM AUTHOR]

Bacteriosis has caused significant economic losses in farmed blunt snout bream Megalobrama amblycephala. Only scarce information is available on Acinetobacter johnsonii as a possible causal agent in M. amblycephala. In this study, a virulent strain temporarily named BY3, was isolated from diseased bream, identified phenotypically and molecularly as A. johnsonii. Phylogenetic trees of 16S rRNA and gyrB gene sequences were constructed to examine the taxonomic position of isolate BY3 and compare it to other known isolates. When screened against a range of common veterinary antibiotics, isolate BY3 has not shown resistance to florfenicol, neomycin, and sulfisoxazole antibiotics in aquaculture. To the best of our knowledge, this is the first report of A. johnsonii infection in farmed blunt snout bream. [ABSTRACT FROM AUTHOR]

Enteritis has caused significant economic losses in farmed channel catfish Ictalurus punctatus. Yet information is limited on Enterobacter aerogenes as a potential causal agent for enteritis in channel catfish. In this study, a virulent strain, temporarily named HT2, was isolated from diseased channel catfish suffering from enteritis, identified phenotypically and molecularly as E. aerogenes. A phylogenetic tree was constructed to examine isolate HT2 and compare it to other known isolates. In addition, isolate HT2 is apparently susceptible to aminoglycosides and quinolones, drugs for veterinary use in aquaculture as seen when screened against a range of common antibiotics. To the best of our knowledge, this is the first report of E. aerogenes as a pathogen causing enteritis in farmed channel catfish. [ABSTRACT FROM AUTHOR]

Whiteleg shrimp Penaeus vannamei is an important commercial shrimp species cultivated in China and many other countries worldwide. Bacteriosis is a major economic problem that inhibits the farming of this species in fresh water. White feces syndrome is an emerging epidemic in freshwater cultured P. vannamei and has caused significant economic damage. Only scarce information is available on Vibrio cholerae as a possible causal agent for this disease. In this study, a virulent strain BB31 was isolated from diseased P. vannamei suffering from white feces syndrome, and identified as a V. cholerae isolate through phylogenetic analysis and phenotypic characteristics. A phylogenetic tree was constructed to examine the relationship of isolate BB31 to other V. cholerae isolates. Three genes encoding hemolysin, outer membrane protein, and cholera toxin transcriptional activator were present in the BB31 isolate confirming its potential pathogenicity. In addition, isolate BB31 is known to have developed resistance to penicillin, sulfonamides and cephalosporin antibiotics. This was demonstrated when screened against a range of common antibiotics for aquaculture and veterinary use. To the best of our knowledge, this is the first report of white feces syndrome caused by V. cholerae in freshwater farmed P. vannamei. [ABSTRACT FROM AUTHOR]

Bacteriosis has become a major global economic problem in freshwater farmed whiteleg shrimp Penaeus vannamei. However, limited information is available on the incidence of Aeromonas schubertii infections in freshwater cultured P. vannamei. Red body disease, an epidemic frequently associated with P. vannamei freshwater farming, occurred in a P. vannamei farm in Shanghai China in June 2013. A pathogenic strain of A. schubertii (isolate HS1) was isolated from diseased freshwater cultured P. vannamei suffering from red body disease, and identified through phylogenetic analysis and phenotypic characteristics. A phylogenetic tree was constructed to examine the relatedness of isolate HS1 with other A. schubertii isolates. In addition, isolate HS1 showed no signs developing antibiotic resistance when screened against a range of common antibiotics used in aquaculture. To the best of our knowledge, this is the first report of A. schubertii infection in freshwater farmed P. vannamei. [ABSTRACT FROM AUTHOR]

In the present study, a pathogenic strain, JL, was isolated from Pengze crucian carp (Carassius auratus) eggs suffering from saprolegniosis. It was initially determined as Saprolegnia sp. strain JL. Saprolegnia species have been implicated for significant fungal contamination, involving both living and dead fish and their eggs. A phylogenetic tree was constructed using the maximum parsimony method. The tree shows that the JL strain was closely related to Saprolegnia parasitica isolate SAP171, isolated from Salmo trutta suffering from saprolegniasis in Laukaa, Finland. The minimum inhibitory concentration (MIC) of 20 Chinese herbs was screened. Pseudolarix kaempferi Gord. (Pinaceae) was the most effective in inhibiting growth of the bacteria and was chosen for further trial. Significant protective efficacy of 52.63% and 73.68% was obtained against the JL strain in Pengze crucian carp eggs at P. kaempferi concentrations of 12.5 mg/ml and 25.0 mg/ml, respectively. [ABSTRACT FROM AUTHOR]