Whole-Genome Sequence of Chelatococcus daeguensis Strain M38T9, Isolated from Ulu Slim Hot Spring in Malaysia

The growing global population has increased the demand for seafood, making the aquaculture industry a vital food source. However, climate change has negatively impacted the industry as natural inhabitants of aquatic environments such as Vibrio parahaemolyticus are thriving in the warming waters. These foodborne pathogens can cause disease in marine animals, resulting in lowered production rates and substantial economic losses. V. parahaemolyticus is transmitted from these marine animals in aquaculture to humans via raw or undercooked seafood, resulting in gastroenteritis outbreaks. In addition, the extensive use of antibiotics in aquaculture to treat infections within marine animals has led to the development of multidrug-resistant (MDR) V. parahaemolyticus, which threatens the effectiveness of antimicrobial treatments. Thus, it is vital to explore the alternatives of antibiotics in aquaculture to manage the spread of antibiotic resistance. This study aimed to investigate the prevalence of MDR V. parahaemolyticus to provide insight into the current antibiotic resistance patterns of this pathogen and to determine potential anti-Vibrio properties of Streptomyces MUM 178J which was previously isolated from the soils of a mangrove forest in Sarawak, Malaysia. Colony morphology and toxR-assay indicated that all samples tested positive for V. parahaemolyticus. Further identification with genomic analyses confirmed that 64% (64/100) of the isolates were V. parahaemolyticus. The multiple antibiotic resistance index (MAR) of the isolates ranged between 0.07 and 0.57, with 81% (52/64) of the isolates resistant to more than one antibiotic. The isolates were most resistant to ampicillin (98.4%), followed by ceftazidime (53.1%). In contrast, the isolates were highly susceptible to nalidixic acid (98.4%), tetracycline (93.8%), and sulfamethoxazole/trimethoprim (90.6%). They also demonstrated susceptibilities of 89.1% to levofloxacin, oxytetracycline, and gentamicin. Streptomyces sp. MUM 178J exhibited antagonistic effects on select V. parahaemolyticus strain, RP0132, with a minimum inhibitory concentration of 12.5 mg/mL and a minimum bactericidal concentration of 50 mg/mL.

Section: Discussionmentioning

confidence: 99%

Detection of multidrug resistant Vibrio parahaemolyticus and anti-Vibrio Streptomyces sp. MUM 178J

Loo,

Tan,

Law

et al. 2023

“…The genomic DNA of strain B2D was extracted using a MasterPure Complete DNA and RNA Purification Kit (Epicentre Biotechnologies, Madison, WI, USA) [18] . The extracted DNA was eluted in EB buffer (Qiagen).…”

Section: Genomic Dna Extraction and Sample Preparation For Whole Geno...mentioning

confidence: 99%

Genomic and Resistome Analyses of Elizabethkingia anophelis Strain B2D isolated from Dental Plaque of Patient

Goh,

Chua,

Khan

et al. 2024

In this study, strain B2D isolated from a dental plaque sample of a human patient was studied for its general characteristics, taxonomic identification, genome features, and resistome profile. The bacterium exhibited antibiotic resistance to all beta-lactam antibiotics, nitrofuran, and sulfonamides, with high minimum inhibitory concentrations. It was only sensitive to the fluoroquinolone ciprofloxacin and intermediately susceptible to aminoglycoside tobramycin. A preliminary identification through 16S rRNA gene sequences revealed that it shared the highest sequence identity with Elizabethkingia anophelis subsp. endophytica JM-87T (100%) and Elizabethkingia anophelis subsp. anophelis R26T (99.31%). The draft genome of strain B2D was approximately 3.9 Mbp with 50 contigs and 35.5% GC content. A 16S rRNA gene and core genes-based phylogenetic analyses revealed a close phylogenetic relationship between strain B2D and the other Elizabethkingia type strains. An above species level threshold average nucleotide identity value confirmed its taxonomic identity as Elizabethkingia anophelis. Furthermore, we conducted a resistome analysis of strain B2D and Elizabethkingia type strains, revealing the presence of widespread antibiotic resistance genes, including beta-lactamases and genes associated with cationic antiseptic resistance and glycopeptide resistance. Overall, the multidrug resistant profile of strain B2D as elucidated and confirmed through whole genome analysis indicated its potential as a reservoir of beta-lactamase genes. Moreover, its presence within dental plaque in the human oral cavity prompts speculation regarding its role as an opportunistic pathogen capable of causing infections, particularly in immunocompromised individuals.

“…Thereby, less promising candidates could be eliminated, whereas more potential strains could proceed for larger-scale validation [576] . Besides the widely applied probiotics such as Firmicutes, Bacteroidetes and Proteobacteria, the Actinobacteria, marine purple non-sulphur photosynthetic bacterium, salt pan bacteria, and other bacteria from varying sources are also potential candidates for aquaculture application lie in wait for further bioprospection [96,104,[577][578][579][580][581][582][583][584][585][586] .…”

Section: Future Perspectivesmentioning

confidence: 99%

Probiotics: Comprehensive Exploration of the Growth Promotion Mechanisms in Shrimps

Goh¹,

Tan²,

Law³

et al. 2023

As feed accounts for a significant proportion of a farm’s expenditure, animal nutrition is one of the key profit determinants. Attributed to the size-dependent market value, enhancing shrimps' growth is essential to maximize profit. Despite not being the best option, antibiotics are often used as growth-promoting agents in farming. Although this trend is less explicit in aquaculture, increasing production yield is paramount, especially when intensive aquafarming compromises animal growth and increases disease prevalence. However, the environmental and clinical pitfalls of indiscriminate antibiotic usage are surfacing. Fortunately, increasing evidence demonstrated probiotics as a safer, more sustainable, and environmental-friendly substitute for antibiotics. Nonetheless, most studies are observational, and the growth-promotion mechanisms of these agents are yet to be elucidated. In this light, this review aims to decipher the growth promotion mechanisms of probiotics in shrimps based on the primary works conducted. Evidently, probiotic treatment modulates the gut microbiome composition. The growth promotion effect of probiotics is partly mediated through the production of bioactive compounds such as short-chain fatty acids, vitamins, and polyamines. Besides, elevated digestive enzyme activities following the introduction of probiotics may help enhance digestibility and utilization. Histological changes at the hepatopancreas and intestine were evident. Furthermore, probiotics may reinforce the protective mechanisms in the gut and strengthen immune function. Treated shrimps demonstrate better appetite and exhibit superior metabolic and growth-related genes profile. Contrasting these recognized mechanisms with antibiotics helps construct the initial framework for designing high-quality probiotics for growth enhancement in farmed animals.