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Aquaculture is gaining prominence in meeting the increasing global food demand. However, persistent episodes of pathogenic infections have greatly affected production and incurred substantial financial losses to the industry. Regrettably, there is a lack of effective contemporary therapeutic measures to control infectious diseases in aquaculture. The repercussions of antimicrobial resistance have underscored the drawbacks of the contemporary practice of relying solely on antibiotics in disease control. The aquaculture industry needs a safer, environmentally viable, and economically efficient means for disease management. In this regard, this study aims to investigate the effectiveness of mangrove-derived Streptomyces sp. probiotics in controlling Vibrio parahaemolyticus infections. In vitro screenings were undertaken to evaluate the inhibitory activity of five Streptomyces sp. isolates. Subsequently, a series of in vivo trials was conducted, with the Malaysian giant freshwater prawn, Macrobrachium rosenbergii larvae as the animal model. Following that, molecular analyses were employed to examine the changes in gene expression. In essence, Streptomyces sp. MUM 195J emerges as a promising probiotic strain that demonstrates a strong inhibitory effect against V. parahaemolyticus. Its application as a feed additive elevates the survival rate of M. rosenbergii threefold, thus demonstrating efficacy at par with florfenicol antibiotic when challenged with the V. parahaemolyticus pathogen. Besides, Streptomyces sp. MUM 195J elevated the growth rate of M. rosenbergii by 17%. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis revealed that probiotic supplementation elevated the immune function of the animal. Additionally, Streptomyces sp. MUM 195J demonstrates the potential to ameliorate the quality of the rearing water. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Streptomyces sp. is a group of filamentous, Gram-positive bacteria well known for their capabilities in producing bioactive compounds that have been used as novel drugs and lead in drug development. The Streptomyces sp. MUM 178J was isolated from a mangrove forest in Malaysia. This isolate was found to harbor anti-Vibrio properties as its crude extract inhibited the growth of multidrug-resistant Vibrio parahaemolyticus. Therefore, the strain was subjected to whole genome sequencing to unearth its genomic potential. The genome of Streptomyces sp. MUM 178J consists of 6,699,249 bp with a G+C content of 71.3%. 66 tRNA genes and 18 rRNA genes were also predicted to be present within the genome. Further analysis with the bioinformatics tool, antiSMASH (antibiotics & Secondary Metabolite Analysis Shell), detected nine biosynthetic gene clusters displaying more than 70% similarity to known gene clusters, including one associated with melanin production. Melanin has demonstrated antagonistic activity against the growth of members of the Vibrio family, including V. parahaemolyticus. This indicates the potential correlation between the production of melanin and the anti-Vibrio properties of MUM 178J. The availability of the whole genome sequence of Streptomyces sp. MUM 178J allows for future in-depth investigation and potential exploitation of MUM 178J to harvest useful bioactive compounds. [ABSTRACT FROM AUTHOR]

As the world recovers from the COVID-19 pandemic, concern remains for future potential outbreaks because of the persisting effects of climate change, including the proliferation of infectious diseases. The frequent isolation of Vibrio parahaemolyticus in the surrounding environment is of concern as it can cause infections in marine animals and transmitted to humans. V. parahaemolyticus is the leading cause of foodborne gastroenteritis worldwide. Malaysia is one of the top seafood consumers and this places us at a higher risk of exposure to V. parahaemolyticus infections. Over the years, this foodborne pathogen has been isolated from various sources in Malaysia, mainly from seafood such as shellfish, shrimps, and fish. To make matters worse, there has been an emergence of antibiotic-resistant V. parahaemolyticus worldwide, which is attributed to the uncontrolled use of antibiotics in aquaculture to prevent and treat vibriosis. Therefore, it is vital to utilize alternatives such as probiotics to control V. parahaemolyticus to prevent further propagation of antibioticresistant strains of the bacteria. A potential candidate for probiotics is Streptomyces sp., a class of filamentous, Gram-positive bacteria that produce a variety of bioactive compounds during their life cycle, which can be useful in drug discovery. The bioactive compounds produced by Streptomyces sp. have been proven to have microbiota-modulating and stimulatory effects on the host, enhancing immunity and providing protective effects against V. parahaemolyticus infections. With the application of Streptomyces sp. as probiotics in aquaculture, the efficacy of the available antibiotics can be preserved, and the further spread of antibiotic resistance in the environment can be reduced. [ABSTRACT FROM AUTHOR]

Streptomyces learnhanii sp. nov. MUM 203JT was isolated from Malaysia mangrove soil. This Gram-positive bacterium produces pale greenish-yellow aerial and greyish-yellow substrate mycelia on ISP 2 agar. The taxonomy status of strain MUM 203JT was determined via a polyphasic approach comprising phenotypic observations, genomic and phylogenetic analyses, and chemotaxonomic analyses. The strain demonstrated typical Streptomyces features based on a series of phenotypic and chemotaxonomic evaluations. In particular, the cell wall peptidoglycan contained LL-diaminopimelic acid, and the predominant menaquinones detected include MK9(H8). Analysis of whole-cell sugars revealed the presence of glucose, ribose and mannose. The polar lipid profile of the strain comprised lipid, glycolipid, phospholipid, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, phosphoglycolipid, and diphosphatidylglycerol. The major cellular fatty acids (>10.0 %) were anteiso-C15:0 (24.7 %), anteiso-C17:0 (16.4 %), iso-C16:0 (15.7 %), iso-C15:0 (11.5 %), and C16:0 (11.1 %). The closely related type strains for strain MUM 203JT, as determined by phylogenetic analysis, include Streptomyces coeruleorubidus JCM 4359T (98.8 %), Streptomyces coeruleoprunus JCM 6919T (98.5 %), Streptomyces thermocarboxydovorans NBRC 16324T (98.1 %). The DNA–DNA relatedness values between strain MUM 203JT and closely related type strains ranged from 10.7 ± 0.6 % to 23.3 ± 4.7 %. Strain MUM 203JT has a genome size of 6,446,886 bp, with DNA G + C content of 72.26 mol%. Based on the polyphasic study of strain MUM 203JT, it can be concluded that this strain represents a novel species, for which the name Streptomyces learnhanii sp. nov. is proposed. The type strain is MUM 203JT (= NBRC 114250T = MCCC 1K04200T). [ABSTRACT FROM AUTHOR]

Vibrios are a group of Gram-negative bacteria ubiquitous in our surrounding environments and responsible for various clinically significant human infections. The three species responsible for human illness are Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus. V. cholerae causes cholera which may result in severe dehydration and death without timely treatment, V. parahaemolyticus infection causes gastroenteritis while V. vulnificus infections typically manifest as wound or soft tissue infections with poor prognosis, including amputation or death. Available data on the epidemiology and clinical burden of Vibrio infections were compiled systematically following a literature review, and 149 relevant studies published between 2010 to 2022 were identified. Cholera represents the majority of Vibrio infections, affecting individuals of all ages and gender, while V. parahaemolyticus infections were found to affect mostly adult males. V. vulnificus infections were mostly reported in males over 50 years old with pre-existing co-morbidities. This review's findings may guide planning and implementing preventative measures in affected regions to prevent future Vibrio infections, disease transmission, and major outbreaks. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) remains one of the top cancers in the world. Although early detection improves the survival rate to around 90%, late detection would mean the need to use chemotherapy or radiotherapy, especially if surgery is not feasible. 5-fluorouracil (5- FU) is one of the common anti-cancer drugs used in treating CRC. It is the drug that has the greatest efficacy on CRC. Although it improves the survival rate, it has many detrimental side effects. One of these side effects is intestinal mucositis. It is described as having reduced villus height, villus atrophy, crypt fissure, abdominal discomfort, diarrhoea, and weight loss. Clinically, there is no conclusive treatment therapy for mucositis. This is possibly due to the complex mechanism of the pathobiology of intestinal mucositis that includes the production of pro-inflammatory cytokines and increased epithelial cell apoptosis. 5-FU itself is known to cause gut dysbiosis. Current studies revealed probiotics play a role in attenuating this inflammatory process of intestinal mucositis by reversing gut dysbiosis, reducing the expression of pro-inflammatory cytokines, and reducing intestinal damage. This review outlines the latest evidence supporting probiotic use in ameliorating 5-FU induced intestinal mucositis, thereby promoting good health and well-being in colorectal cancer patients receiving 5-FU chemotherapy. [ABSTRACT FROM AUTHOR]

Streptomyces pluripotens strain MUM 16J is a Gram-positive filamentous bacteria isolated from mangrove soil in Kampung Trombol area of Kuching, Sarawak. The draft genome of Streptomyces pluripotens strain MUM 16J consists of 7,671,699 bp assembled into 164 contigs. The GC content of the genome is 70.06 %, and the sequencing coverage of 108×. Its genome consists of 6,781 predicted genes, 6,459 protein-coding genes, and 79 RNA-coding genes (tRNA: 71, rRNA: 8). Here we report the draft genome of this strain to highlight its potential in producing glycopeptide antibiotic as well as catechol, a biocontrol agent of biofilm-producing bacteria. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has plagued the world for over three years since discovering the causative virus, SARS-CoV-2, in China. The rampant spread of the virus led to the loss of livelihoods of millions across the globe. This public health emergency prompted the rapid development of vaccines and treatments to fight against viral infection. Vaccines against the viral infection started rolling out in late 2020, and the distribution of the vaccines worldwide managed to reduce the symptoms of COVID-19 and prevent outbreaks in local communities. However, COVID-19 infections are still prevalent, with patients suffering from severe symptoms which require oxygen support or mechanical ventilation. Thus, therapeutic agents for COVID-19 play a significant role in reducing the risk of disease progression into severe disease and improving hospitalized patients' clinical outcomes. Existing drugs such as remdesivir, molnupiravir, baricitinib, anakinra, and tocilizumab have been repurposed to treat COVID-19 earlier during the pandemic to meet the urgent demand for treatment. There are also novel antiviral and immunomodulating treatments (nirmatrelvir plus ritonavir, ensitrelvir, regdanvimab, sotrovimab, and vilobelimab) that were developed during the pandemic to fight against COVID-19 infections. These therapeutic agents have been reported to be effective and safe for use to treat COVID-19 infections of different severity. Nevertheless, continuous surveillance is imperative in ensuring that these treatment methods maintain efficacy and safety profiles in treating COVID-19 caused by different variants of the virus. [ABSTRACT FROM AUTHOR]

A novel strain, Streptomyces griseiviridis MUM 136JT was recovered from a mangrove forest soil in Malaysia. The Gram-positive bacterium forms strong yellow aerial mycelium and moderate yellow substrate mycelium on ISP 2 agar. A polyphasic approach was used to determine the taxonomy status of strain MUM 136JT . The strain showed a spectrum of phylogenetic and chemotaxonomic properties consistent with those of the members of the genus Streptomyces. The cell wall peptidoglycan was determined to contain LL-diaminopimelic acid. The predominant menaquinones were identified as MK-9(H8) and MK-9(H6), while the identified polar lipids consisted of lipid, aminolipid, phospholipid, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, diphosphatidylglycerol, and phosphatidylinositolmannoside. The cell wall sugars consist of ribose, mannose, and galactose. The predominant cellular fatty acids (>10.0 %) were identified as iso-C16:0 (31.6 %), anteiso-C15:0 (14.8 %), iso-C15:0 (12.0 %), and anteiso-C17:0 (11.1 %). Phylogenetic analysis identified that closely related strains for MUM 136JT are Streptomyces leeuwenhoekii DSM 42122T (98.9 %), Streptomyces erythrogriseus JCM 9650T (98.4 %), Streptomyces griseoincarnatus JCM 4381T (98.5 %). The DNA-DNA relatedness values between MUM 136 JT and closely related type strains ranged from 13.3 ± 1.5 % to 17.4 ± 2.0 %. The name Streptomyces griseiviridis sp. nov. is proposed, and the type strain is MUM 136JT (= NBRC 114249T = MCCC 1K04199T ). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]