Identification of Elizabethkingia meningoseptica from American bullfrog (Rana catesbeiana) farmed in Sabah, Malaysia using PCR method and future management of outbreak

Aims: High demand for frog meat in Malaysia especially the American bullfrog (Rana catesbeiana) has promoted intensive farming of the animal. However, the farming of American bullfrog is restricted by the occurrence of diseases. This study reports the first isolation of Elizabethkingia meningoseptica from specimens of American bullfrog that suffer from cataract and ‘red-leg’ syndrome.Methodology and Result: The pathogen was isolated from eyes and internal organs (liver, kidney and spleen) of thediseased bullfrog specimens. All the bacterial isolates were subjected to phenotypic characterization and antibiotic susceptibility assay, and further identified by using the 16S rDNA sequencing analysis. We designed two pair of specific PCR primers (22-25 mers) which are complimentary to the β-lactamase gene in the reference strain ofE. meningoseptica ATCC49470. The result showed all the bacterial isolates shared similar phenotypic characters and antibiotic susceptibility. BLAST analysis of the 16S rDNA sequences indicated that the bacterial isolates had very high sequence homology (100%) with E. meningospetica ATCC49470 and E. meningoseptica isolates from mosquito. The two PCR primers were very specific to E. meningoseptica isolates of this study. Conclusion, significance and impact of study: This is the first isolation and characterization of bacterial pathogen, E. meningoseptica in cultured American bullfrog (Rana catesbeina) that suffered from eye cataract and ‘red-leg’syndrome in Sabah, Malaysia. It is suspected that one of the possible transmission routes of the bacterial pathogen could be via mosquito bites. The findings suggest that there is urgent requirement for standard guideline of good farming practice to be adopted in frog farms throughout the country. Such a guideline can help in minimizing economic losses, preventing transmission of the zoonotic bacterial pathogen to farm workers, and sustaining the industry in Malaysia andupgrading frog meat quality for international market

Identification of Elizabethkingia meningoseptica from American bullfrog (Rana catesbiana) farmed in Sabah, Malaysia using PCR method and future management of outbreak

Aims: High demand for frog meat in Malaysia especially the American bullfrog (Rana catesbeiana) has promoted intensive farming of the animal. However, the farming of American bullfrog is restricted by the occurrence of diseases. This study reports the first isolation of Elizabethkingia meningoseptica from specimens of American bullfrog that suffer from cataract and 'red-leg' syndrome. Methodology and Result: The pathogen was isolated from eyes and internal organs (liver, kidney and spleen) of the diseased bullfrog specimens. All the bacterial isolates were subjected to phenotypic characterization and antibiotic susceptibility assay, and further identified by using the 16S rDNA sequencing analysis. We designed two pair of specific PCR primers (22-25 mers) which are complimentary to the β-lactamase gene in the reference strain of E. meningoseptica ATCC49470. The result showed all the bacterial isolates shared similar phenotypic characters and antibiotic susceptibility. BLAST analysis of the 16S rDNA sequences indicated that the bacterial isolates had very high sequence homology (100%) with E. meningospetica ATCC49470 and E. meningoseptica isolates from mosquito. The two PCR primers were very specific to E. meningoseptica isolates of this study. Conclusion, significance and impact of study: This is the first isolation and characterization of bacterial pathogen, E. meningoseptica in cultured American bullfrog (Rana catesbeina) that suffered from eye cataract and 'red-leg' syndrome in Sabah, Malaysia. It is suspected that one of the possible transmission routes of the bacterial pathogen could be via mosquito bites. The findings suggest that there is urgent requirement for standard guideline of good farming practice to be adopted in frog farms throughout the country. Such a guideline can help in minimizing economic losses, preventing transmission of the zoonotic bacterial pathogen to farm workers, and sustaining the industry in Malaysia and upgrading frog meat quality for international market

Description of Goussia kuehae n. sp. (Apicomplexa: Eimeriidae) infecting the Asian seabass, Lates calcarifer (Bloch)(Perciformes: Latidae), cultured in Malaysian fish farms

Culturing fishes in marine cages is a rapidly developing area of marine aquaculture. The Asian seabass Lates calcarifer (Bloch) is a fast growing good quality fish that is readily cultured in intensive systems in the South Asian region and in Malaysia in particular. Although several papers have been published to date on viral, bacterial, parasitic and fungal organisms causing diseases in the Asian seabass, the occurrence of a coccidian infection in this species has only recently been recorded. We collected sporulated and unsporulated oo¨cysts of a new species of Goussia Labbe´, 1986, from the mucus covering the epithelium of the intestine of L. calcarifer. This paper provides a description of Goussia kuehae n. sp. Sporulated oo¨cysts of this species are ellipsoidal, 37–40 lm in length and 28–30 lm in width. The ellipsoidal sporocysts are relatively small, 15.2–17 9 5.7–8 lm, and located loosely in the oo¨cyst. There are residual bodies both in the oo¨cysts and the sporocysts. Goussia kuehae n. sp. differs from all known species of Goussia in the large size of the oo¨cysts and in having two types of oo¨cyst residuum

A Nonluminescent and Highly Virulent Vibrio harveyi Strain Is Associated with “Bacterial White Tail Disease” of Litopenaeus vannamei Shrimp

Recurrent outbreaks of a disease in pond-cultured juvenile and subadult Litopenaeus vannamei shrimp in several districts in China remain an important problem in recent years. The disease was characterized by “white tail” and generally accompanied by mass mortalities. Based on data from the microscopical analyses, PCR detection and 16S rRNA sequencing, a new Vibrio harveyi strain (designated as strain HLB0905) was identified as the etiologic pathogen. The bacterial isolation and challenge tests demonstrated that the HLB0905 strain was nonluminescent but highly virulent. It could cause mass mortality in affected shrimp during a short time period with a low dose of infection. Meanwhile, the histopathological and electron microscopical analysis both showed that the HLB0905 strain could cause severe fiber cell damages and striated muscle necrosis by accumulating in the tail muscle of L. vannamei shrimp, which led the affected shrimp to exhibit white or opaque lesions in the tail. The typical sign was closely similar to that caused by infectious myonecrosis (IMN), white tail disease (WTD) or penaeid white tail disease (PWTD). To differentiate from such diseases as with a sign of “white tail” but of non-bacterial origin, the present disease was named as “bacterial white tail disease (BWTD)”. Present study revealed that, just like IMN and WTD, BWTD could also cause mass mortalities in pond-cultured shrimp. These results suggested that some bacterial strains are changing themselves from secondary to primary pathogens by enhancing their virulence in current shrimp aquaculture system

Feasibility study of applications of micro-bubbles for aquaculture

Micro-bubbles are ultra-fine gas bubbles in water, of which size is less than 50μm. As they are suspended in water, the bubbles shrink spontaneously to nanometer level and eventually disappear. The characteristic feature is the negatively charged surface and self-pressured effects, which may enable a variety of possibilities of applications for aquaculture. In 2004 a research group of National Institute of Advanced Industrial Science & Technology (AIST) in Japan succeeded in inactivation of norovirus in oyster aquaculture (Takahashi, 2004). Here we’ll discuss further possibilities of this new technology for aquaculture

Prevalence of multi-antibiotics resistant (MAR) Vibrio parahaemolyticus in shrimp farms in Sarawak, Malaysia

The shrimp farming industry is constantly under threat due to outbreaks of infectious diseases and environmental problems. Vibrio parahaemolyticus is an important foodborne pathogen causing significant economic losses within the shrimp aquaculture industry worldwide. This research aimed to determine the prevalence of V. parahaemolyticus from different shrimp farms from the stocking to harvesting period and assess the antibiotic susceptibility of V. parahaemolyticus using the antimicrobial susceptibility test (AST). In this study, a total of 288 samples comprising twenty-four from each sample consisting of shrimp, water, effluent, and sediment samples were collected aseptically from three (n = 3) shrimp farms located at Telaga Air Farm 1 (Pond 6), Telaga Air Farm 2 (Pond 9) and Santubong Farm (Pond 7), Kuching, Sarawak. A molecular approach by polymerase chain reaction was used to confirm the presence of regulator gene, toxR, V. parahaemolyticus. A total of 14 antibiotics, including spectinomycin (SH100), imipenem (IPM10), amoxycillin/clavulanic acid (AMC30), enrofloxacin (ENR5), bacitracin (B10), meropenem (MEM10), cephalothin (KF30), penicillin G (P10), tetracycline (TE30), kanamycin (K30), streptomycin(S25), rifampicin (RD2), erythromycin (E15), and nalidixic acid (NA30) were used. The results obtained showed that 51/288 (17.71%) of the collected samples with regulator gene, toxR V. parahaemolyticus. As a whole, this includes 31.25% (30/288) from sediment samples, 4.17% (4/288) from shrimp samples, 15.63% (15/288) from water samples, and 2.08% (2/288) from effluent water samples. A total of 54.9% (28/51) of V. parahaemolyticus acquired multiple antibiotic resistance (MAR). The resistance of antibiotics was profiled, and the multiple antibiotic resistance (MAR) indexes and classified into ten patterns. The MAR index of V. parahaemolyticus isolates ranged from 0.11 to 0.36. Vibrio parahaemolyticus isolates showed 31.38% with a MAR index > 0.2, indicating that these isolates might be originated from high-risk sources. The data obtained from this study is helpful to monitor the presence of V. parahaemolyticus in the aquaculture farm management system to mitigate the hazard potentially arising from the environmental factor that causes shrimp diseases and shrimp infection

Characteristics of Population Growth and Mortality of Windu Shrimp (Penaeus Monodon) in the Juata Water of Tarakan City, Indonesia

HighlightThe sex ratio of tiger prawns in the waters of female groceries is 1.08 times higher than that of males.The growth characteristic of male and female tiger prawns is negative allometry, but the male and female body shapes are fat.Fishing mortality, capture mortality, exploitation rate, female tiger prawns are higher than males, but total mortality and natural mortality male tiger prawns are higher than females.The male infinitive growth is longer than the female.AbstractThe windu shrimp (Penaeus monodon) is an economically important fishery species in the waters of Tarakan. The shrimp is highly demanded for frozen seafood industry that makes its market price range attractive from Rp. 50,000 (USD 3.37) to Rp. 70,000 (USD 4.72)/kg. This can cause the species to be potentially exploited. However, due to lack of data, the exploitation status of the windu shrimp is unknown. Hence, the present study was carried out to determine the absolute growth, mortality, and exploitation level of the windu shrimp in Juata waters of Tarakan. Sampling of the shrimp using experimental trawling net was conducted four times between June and August 2020 in the waters of Tarakan. Morphometric data of the windu shrimps including sex, total length, carapace length, and total weight were recorded and analyzed. The results showed that the sex ratio of male and female tiger prawns was 1:1.08. The maximum growth of male and female shrimps was estimated at 26.875 and 21.435 cm respectively. The size of the male shrimps caught during the sampling ranged between 8.7 and 22.5 cm, and was estimated to be at 13 to 67 days old respectively. Maximum growth of male shrimp was estimated at 26.875 cm that could be achieved within 411 days. The size of female shrimp caught during the sampling ranged from 9.8 to 19.3 cm with an estimated age of 21 to 87 days respectively. The maximum growth for female shrimp was estimated at 21.435 cm, and achievable within 377 days. The mortality of male and female shrimps was not significantly different at 110.3% and 110.1% respectively. The fishing mortality for male and female shrimps was recorded at 19% and 22.5% respectively. The level of exploitation of male and female shrimps was slightly different at 17.2% and 20.5%, respectively. Finally, the natural mortality for male and female shrimps was at 91.3% and 87.5%, respectively