Partial 16S rRNA Gene Research Articles

High Prevalence of Sarcocystis in a Collapsed Black Rat (Rattus rattus) Population from the Florida Keys.

We collected and screened black rats (Rattus rattus) in Key Largo, Florida, USA, to determine the potential role of disease or parasites in the collapse of the local population. Rats appeared healthy, but 94% (n=15/16) tested positive for Sarcocystis sp. The partial 18S rRNA gene sequence was 98.7-99.7% similar to a strain of Sarcocystis zuoi that is now considered a strain of the newly described Sarcocystis kani within the larger S. zuoi species complex that contains numerous new species. These Sarcocystis spp. use Asian snakes as definitive hosts and rodents, shrews, or tree shrews as intermediate hosts. Pythons are the definitive host for several Sarcocystis spp. in Asia, including a related parasite (Sarcocystis singaporensis) that has been used as a biologic control agent for Rattus spp. in southeast Asia. It is probable that increasing numbers of invasive Burmese pythons (Python bivittatus) in the Florida Keys are contributing to the spread of this parasite in addition to imposing predation pressure on both rodents and native snakes. As such, further surveillance and molecular and morphologic characterization of parasites from rodents and snakes in south Florida should be prioritized.

Isolation, Characterization and Molecular Identification of Bacteria Associated with Green and Brown Seaweeds

Aims: The co-existence of bacterial communities along with macroalgae in marine environment develops a mutualistic relationship resulting in functional advantages for both the groups. The present research studied the composition of epiphytic bacteria associated with green (Ulva spp.) and brown seaweeds (Sargassum spp. and Padina spp.) sampled off Maharashtra coast, India, and their physiological and bioactive properties. Study Design: Green and brown seaweeds were collected from three locations along Maharashtra coast and analyzed for the associated bacteria. Place and Duration of Study: Seaweed samples analyzed in this study were from Kelwa, Manori and Ratnagiri along the Maharashtra coast. The analysis was performed during June to September 2021. Methodology: Bacteria from freshly collected seaweed samples were homogenized in saline, 10-fold serially diluted and plated on Zobell marine agar. Distinct colonies were selected and identified by a series of biochemical tests, followed by partial 16SrRNA gene sequencing. The physiological characteristics of the isolated bacteria were studied by screening for temperature and salinity tolerance, production of protease, lipase, agarose, amylase and biosurfactants. Results: The total seaweed bacterial count ranged from 4.5 ×103 to 2.9 × 104 CFU/g. Seventy-seven bacteria were isolated, 44 (57.14%) and 33 (42.85%) isolates from green and brown seaweeds respectively. The 16SrRNA sequencing of 20 representative isolates revealed the dominance of Bacillus spp., followed by Vibrio spp. Growth at 0°C was exhibited by all bacteria except Bacillus tequilensis, Bacillus altitudinis, Oceanobacillus iheyensis and one isolate of Vibrio spp. A majority of the isolates grew at 45°C. Vibrio spp. exhibited protease, amylase, gelatinase, and agarase activities, whereas the biosurfactant activity was commonly associated with Bacillus spp. Conclusion: The results of this study illustrate the occurrence of seaweed-associated beneficial bacteria exhibiting bioactive properties with potential biomedical applications.

Morphological and molecular identification of Eimeria rajasthani (coccidia: Eimeriidae) in the dromedary camel (Camelus dromedarius) in Riyadh, Saudi Arabia

IntroductionCoccidiosis is a serious parasitic disease in camels caused by an intestinal protozoan parasite of the genus Eimeria, which is linked to significant causes of reduced milk and meat production. In Saudi Arabia, scare literature focused on the coprological investigation of dromedary camels (Camelus dromedarius). To determine the taxonomic status of camel parasite species, we performed morphological characterization of oocysts and genetic analysis (18S rRNA and ITS-1 gene regions) of Eimeria species collected from camels in Riyadh, Saudi Arabia.MethodsA total of 150 faecal samples were obtained from camels at the old camel market. These samples were tested for the presence of Eimeria oocysts using the conventional floatation technique before being sporulated in a 2.5% potassium dichromate solution. Eimeria oocysts were morphologically and molecularly examined and identified, and the infection rate of parasitic infections was determined.ResultsOur findings revealed that the overall frequency of oocysts was 30%. The identified species was Eimeria rajasthani, which had a typical ellipsoidal oocyst shape. Oocystic polar granule, micropyle, micropylar cap, and oocyst residuum are not visible. Sporocysts are oval with stieda body. Sporocyst residuum contains many granules and sporozoites with refractile bodies and nuclei. Genetic analyses of the sequence data from the partial 18S rRNA and ITS-1 gene regions revealed that the sequences obtained from E. rajasthani oocysts are related to DNA sequences reported from E. lamae from the Alpaca from China, particularly the 18S rRNA sequences.ConclusionThis study emphasized the need to use molecular phylogenetic tools to describe camel intestinal coccidian parasites with traditional morphology-based approaches to better understand their biology. For camel husbandry and disease control, more studies should be conducted to better understand the epidemiology of these protozoan parasites.

First Report of Robbsia andropogonis Causing Bacterial Blight of Danae racemosa (Poet’s Laurel) in a Virginia Ornamental Nursery

Danae racemosa (L.) Moench (Asparagaceae, Monocots) is a shade-tolerant, evergreen shrub native to Persia. On 02 July 2024, at an ornamental nursery in Hanover County, Virginia, 300 plants in 7.6 L containers were observed with blotchy, rust-colored, water-soaked lesions on the cladophylls and stems. Heavy bacterial streaming was observed from the lesions under the microscope, and sterilized tissue was cultured on King's B medium at 22 ± 2°C. After 72 hours, cream-colored colonies developed that were oxidase and gram negative and did not produce fluorescent pigments on King B medium. PCR amplification and sequencing of the partial 16S rRNA, gyrB, and rpoD genes from strain GS24-DSB16 were deposited into the NCBI Genbank database (PQ181184, PQ182786, PQ182787). Based on the morphological and molecular characteristics, the causal agent was identified as Robbsia andropogonis (Smith) Lopes-Santos et al. Koch’s postulates were fulfilled by wounding twenty cladophylls from each plant with a sterile needle, and 10 μl of an aqueous bacterial suspension was pipetted on each wound. R. andropogonis has a wide global distribution from a host range spanning >15 plant families, including maize, sorghum, sugarcane, citrus, coffee, and carnation. To the authors knowledge, this is the first report of the bacteria causing blight on D. racemosa, and the first host in Asparagaceae.

Integrating short- and full-length 16S rRNA gene sequencing to elucidate microbiome profiles in Pacific white shrimp (Litopenaeus vannamei) ponds.

Despite their immense economic value as a key aquaculture species, the production of Pacific white shrimp (Litopenaeus vannamei) faces significant challenges from intensive farming practices and disease outbreaks. Routine microbial profiling for disease surveillance could be a promising approach to anticipate and control disease outbreaks. To achieve this, accuracy in microbial profiling in shrimp ponds is crucial for enabling targeted action and prevention. Extensive documentation emphasizes that, beyond biological factors (related to the host, diet, or health status during the rearing period), technical elements, including sequencing techniques significantly influence bacterial community profiling. This study investigated the influence of short- and long-read sequencing of 16S rRNA genes on the microbial profiles in shrimp intestines, water, and sediments. The origin of the samples (intestine or environmental) in shrimp culture ponds primarily drove the observed differences in core microbial species. The ecological niches accounted for 56% of bacterial community variations in culture ponds. Both sequencing approaches showed consistent results in identifying higher-rank taxa and assessing alpha and beta diversity. However, at the species level, full-length 16S rRNA gene sequences provided better resolution than V3-V4 sequences. For routine microbial profiling in shrimp culture ponds, our study suggests that short-read sequences were sufficient for determining overall bacterial community.IMPORTANCEThis interdisciplinary study investigated the influence of sequencing techniques on bacterial communities profiling within Pacific white shrimp (Litopenaeus vannamei) ponds. By integrating aquaculture, microbiology, and environmental science, we revealed the role of ecological niches and factors like salinity and pH on microbiota diversity and composition in shrimp intestines, pond water, and sediment. Additionally, we compared the taxonomic resolution using partial versus full-length 16S rRNA gene sequences, highlighting the value of longer amplicons for precise identification of key taxa. These findings provide novel insights into microbial dynamics underlying environmental effects in shrimp aquaculture. Comprehensive characterization of the pond microbiome could lead to management strategies that promote shrimp health and productivity. Furthermore, the potential of a multi-omics approach for integrating complementary data streams to elucidate environment-microbiome-host interactions was highlighted.

1-Acetyl-β-Carboline from a Jeju Gotjawal Strain Lentzea sp. JNUCC 0626 and Its Melanogenic Stimulating Activity in B16F10 Melanoma Cells.

The genus Lentzea is a prolific source of bioactive and structurally diverse secondary metabolites. We isolated a novel strain, Lentzea sp. JNUCC 0626, from Hwasun Gotjawal on Jeju Island, Korea. Based on 16S rRNA partial gene sequence analysis, strain JNUCC 0626 is closely related to Lentzea isolaginshaensis NX62 (99.41% similarity), Lentzea pudingi DHS C021 (99.31%), and Lentzea cavernae SYSU K10001 (99.26%). From the fermentation broth of JNUCC 0626, we isolated 1-acetyl-β-carboline, whose structure was established using IR, HR-ESI-MS, and 1D- and 2D-NMR techniques. 1-acetyl-β-carboline was found to activate melanogenesis in mouse B16F10 cells without cytotoxicity at concentrations up to 50 μM. At this concentration, the compound increased melanin content by 27.44% and tyrosinase activity by 240.64% compared to the control, by upregulating key melanogenic enzymes, including tyrosinase, TRP-1, TRP-2, and microphthalmia-associated transcription factor (MITF), a central regulator of melanogenesis. In addition, 1-acetyl-β-carboline significantly inhibited ERK phosphorylation, reducing it by 20.79% at a concentration of 12.5 μM and by 25.63% at 25 μM. This inhibition supports the hypothesis that 1-acetyl-β-carboline enhances melanin synthesis by upregulating MITF and melanogenic enzymes via the ERK signaling pathway. This study aimed to isolate and identify 1-acetyl-β-carboline from a novel strain of Lentzea sp. JNUCC 0626, discovered in Gotjawal, Jeju Island, and to evaluate its effect on melanin production in B16F10 melanoma cells. Skin irritation tests on 32 subjects confirmed its safety for topical use, and the findings suggest that 1-acetyl-β-carboline, which enhances melanogenesis without cytotoxicity, holds promise as a therapeutic agent for hypopigmentation-related conditions or as a cosmetic ingredient.

Halorubrum miltondacostae sp. nov., a potential polyhydroxyalkanoate producer isolated from an inland solar saltern in Rio Maior, Portugal

One hundred and sixty-three extreme halophiles were recovered from a single sample collected from an inland solar saltern in Rio Maior. Based on random amplified polymorphic DNA (RAPD) profiles and partial 16S rRNA gene sequencing 125 isolates were identified as members of the Archaea domain within the genus Halorubrum. Two strains, RMP-11T and RMP-47, showed 99.1 % sequence similarity with the species Halorubrum californiense based on phylogenetic analysis of the 16S rRNA gene sequence. However, phylogenetic analysis based on five housekeeping genes, atpB, EF-2, glnA, ppsA and rpoB’, showed Halorubrum coriense as the closest related species with 96.7 % similarity. The average nucleotide identity (ANI) of strains RMP-11T, RMP-47 and species Hrr. coriense were within the range of 90.0–90.5 %, supporting that strains RMP-11T and RMP-47 represent a novel species of the genus Halorubrum. These strains formed red-pigmented colonies that were able to grow in a temperature range of 25–50 °C. Polyhydroxyalkanoate (PHA) granules were detected in both strains. The polar lipid profile was identical to the neutrophilic species of the genus Halorubrum. The Rio Maior sample from which both strains were isolated was metagenome sequenced. We identified five metagenome-assembled genomes representing novel Halorubrum species but distinct from the species represented by strains RMP-11T and RMP-47. Based on phylogenetic, phylogenomic, comparative genomics, physiological and chemotaxonomic parameters, we describe a new species of the genus Halorubrum represented by strains RMP-11T (=CECT 30760T = DSM 115521T) and RMP-47 (=CECT 30761 = DSM 115541) for which we propose the name Halorubrum miltondacostae sp. nov.

Molecular prevalence, epidemiology, and phylogenetic analysis of Babesia microti in dogs with a note on its impact on host hematological profile

Babesia (B.) microti is an intra-erythrocytic protozoan parasite that infects humans as well as domestic and wild animals. Prevalence of B. microti was investigated in 654 apparently healthy dogs belonging to 55 different breeds from three districts in Punjab province (Muzaffargarh, Bahawalpur and Jhang) and two districts in Khyber Pakhtunkhwa province (Dir Upper and Charsadda) in Pakistan. The hematological profile of dogs, risk factors associated with the infection and phylogenetic diversity of the detected isolates were also evaluated. In total, 29 blood samples (4 %) scored PCR positive. Sanger sequencing of partial 18S rRNA gene confirmed the presence of B. microti. The phylogenetic analysis of the sequences based on the 18S rRNA gene displayed global phylogenetic similarity with the isolates that were previously documented from Russia, France, Poland, Spain, China, Japan and USA. The infection rate was consistent across different sampling sites and dog breeds. Sex or presence of ectoparasites on dog was also not associated with B. microti prevalence. Babesia microti infected dogs had elevated red cell distribution width-coefficient of variation (%) than uninfected animals. This study presents updated data about the prevalence of B. microti among local Pakistani dogs and will be helpful in designing control strategies against this tick-borne pathogen as the tick infesting a B. microti infected dog may transmit this parasites to human as well.

Changes in microbial communities during high-rate microbial selenate reduction in an up-flow anaerobic fluidized bed reactor

Biological fluidized bed reactor (FBR) is a promising treatment option for removing selenium oxyanions from wastewater by converting them into elemental selenium. The process can achieve high rates and be efficiently operated at low hydraulic retention times (HRT). However, the effects of HRT on the changes in microbial community in the FBR process have not been previously explored. In this study, dynamic changes of microbial communities both on biofilm carrier and in suspension of a selenate-reducing FBR were explored at various HRTs (0.3–120 h). Based on partial 16S rRNA gene sequencing of the microbial communities, alpha diversity of microbial communities in suspension rather than in the biofilm were impacted by low HRTs (0.3 h–3 h). Members from genera Geobacter, Geoalkalibacter, and Geovibrio were the main selenate-reducing bacteria on carrier throughout the FBR process. Genus Geobacter was dominant in FBR carrier at HRT of 24 h–120 h, whereas Geoalkalibacter and Geovibrio dominated at low HRT of 0.3 h–6 h. Suspended microbial communities detected in the FBR effluent were more sensitive to HRT changes than that in biofilm. “Shock loading” at HRT of 0.3 h had a great impact on microbial community compositions both in the biofilm and effluent. Reactor operation in batch mode and long HRT of 24 h helped recover the community from “shock loading” and improved selenite reduction and ethanol oxidation. Redundancy analysis revealed that HRT, influent pH and selenate loading were key operational parameters impacting both the FBR performance and the composition of microbial communities associated with both the FBR carrier and effluent. Overall, the microbial communities in FBR biofilm flexibly responded to the changes of HRT and showed resilience to the temporary shock loading, enabling efficient selenate removal.

Exploring Listeria monocytogenes in Ewe Milk: ssrA Gene-based Real-time PCR Identification, Phylogenetic Analysis, and Antibacterial Assessment of Magnesium Oxide Nanoparticles Synthesized with Myrtus communis Leaf Extract

Background: Listeria monocytogenes, a zoonotic pathogen affecting humans and animals, exhibits a global distribution, including Iraq. This study focused on the rapid identification and phylogenetic analysis of L. monocytogenes in freshly collected ewe milk samples from various farms in Al-Qadisiyah province, Iraq.Methods: The study was conducted with care and precision, involving 150 milk samples. These samples were subjected to traditional bacterial isolation and identification using the enrichment culture method and biochemical tests, with the PCR technique confirming the results. The antibacterial activity of MgONPs was then assessed using the disc diffusion method, ensuring a comprehensive and reliable approach to the study.Result: The results show that 150 ewe milk samples underwent real-time PCR (RT-PCR) targeting the ssrA gene, followed by partial 16S rRNA gene sequencing (PSGS) of purified conventional PCR products. Furthermore, the study entails the biosynthesis of magnesium oxide nanoparticles using Myrtus communis leaf extract, followed by a comprehensive characterization utilizing UV-spectra, FTIR, SEM, and TEM techniques. The Agar well diffusion method assessed the antibacterial efficacy of these Biosynthesized nanoparticles against L. monocytogenes. The RT-PCR results revealed the presence of L. monocytogenes in 36 out of 150 samples (24%). Subsequent PCR analysis confirmed the presence of the pathogen in 30 out of these 36 positive samples (83.33%). Sequencing of two purified PCR products demonstrated 100% nucleotide identity with global isolates from Iraq and Turkey. Furthermore, the study demonstrated that L. monocytogenes exhibited substantial sensitivity (24.66 ± 0.3) to the biosynthesized magnesium oxide nanoparticles. These findings underscore the speed and precision of the RT-PCR method for detecting L. monocytogenes in fresh ewe milk samples.Conclusion: This comprehensive investigation enhances our understanding of L. monocytogenes prevalence in ewe milk and highlights the potential of Myrtus communis -derived nanoparticles for combating this pathogen.Keywords: Antibacterial nanoparticles; Listeria monocytogenes; Magnesium oxide; Myrtus communis sheep milk; ssrA gene

Prevalence and molecular detection of Babesia microti in rodents in Southeastern Shanxi, China.

Babesia is a tick-transmitted parasite that infects wild and domestic animals, causes babesiosis in humans, and is an increasing public health concern. Here, we investigated the prevalence and molecular characteristics of Babesia infections in the rodents in Southeastern Shanxi, China. Small rodents were captured, and the liver and spleen tissues were used for Babesia detection using traditional PCR and sequencing of the partial 18S rRNA gene. The analysis revealed that 27 of 252 small rodents were positive for Babesia, with an infection rate of 10.71%. The infection rates in different sexes and rodent tissues were not statistically different, but those in different rodent species, habitats, and sampling sites were statistically different. The highest risk of Babesia infection was observed in Niviventer confucianus captured from the forests in Huguan County. Forty-three sequences from 27 small rodents positive for Babesia infection were identified as Babesia microti, including 42 sequences from 26 N. confucianus, and one sequence from Apodemus agrarius. Phylogenetic analysis showed that all sequences were clustered together and had the closest genetic relationship with Babesia microti strains isolated from Rattus losea and N. confucianus in China, and belonged to the Kobe-type, which is pathogenic to humans. Compared to other Kobe-type strains based on the nearly complete 18S rRNA gene, the sequences obtained in this study showed the difference by 1-3 bp. Overall, a high prevalence of Babesia microti infection was observed in small rodents in Southeastern Shanxi, China, which could benefit us to take the implementation of relevant prevention and control measures in this area.

Molecular detection of Cryptosporidium parvum in wild rodents (Phyllotis darwini) inhabiting protected and rural transitional areas in north-central Chile

Wild rodents often harbor Cryptosporidium species that can be transmitted to multiple mammal hosts. In Chile, little is known about Cryptosporidium in wild rodents, and available studies have been focused on morphological findings with no molecular-based evidence. A longitudinal survey was conducted between 2021 and 2022 to investigate the occurrence of Cryptosporidium spp. in populations of the Darwin's leaf-eared mouse (Phyllotis darwini) living in protected and rural transitional areas in north-central Chile, using staining and molecular methods. A total of 247 fecal samples were collected and examined by the modified Ziehl–Neelsen (ZN) staining test, 54 of which were positive for Cryptosporidium-like oocysts. Molecular analyses were carried out by PCR of the partial 18S ribosomal RNA and 60 kDa glycoprotein (gp60) genes. Cryptosporidium infection was confirmed in 34 samples (13.7 %) based on the PCR amplification, and individual (i.e., sex, and body mass index) and ecological variables (i.e., type of site and season) were not statistically significant (p > 0.05). Using the nucleotide sequencing of the partial 18S rRNA gene, Cryptosporidium parvum was identified in nine isolates. Also, C. parvum subgenotype family IIa was determined in seven samples by the partial gp60 gene, including the subtype IIaA17G4R1 in two samples. This is the first molecular evidence of Cryptosporidium parvum IIa in Phyllotis darwini in Chile. These results indicate potential cross-species transmition between wild rodents and domestic-wild animals in north-central Chile. More research is needed to understand better the role of wild rodents in the transmission of Cryptosporidium spp. in Chile.

Incidence and pathological effects during encysted progenetic Euclinostomum heterostomum metacercariae infection in the freshwater fish spotted snakehead (Channa punctatus)

Aim: To assess the incidence and pathological effects during encysted progenetic Euclinostomum heterostomum metacercariae infestation in the freshwater fish spotted snakehead (Channa punctatus). Methodology: Samples of Channa punctatus were collected from Tilaiya Reservoir, Koderma, Jharkhand, India, during pre-monsoon, monsoon, and post-monsoon seasons. The encysted metacercariae trematodes were isolated from Channa punctatus. Characterization was performed based on the morphology and sequencing analysis of a partial 18S rRNA gene. Further, the kidney and liver samples from infected fish were subjected to histopathological studies. Prevalence, abundance, and Intensity of infection were further determined. Results: Morphological identification suggests that the encysted metacercariae belonged to Digenean trematodes of genera Euclinostomum, and amplification of partial sequence of 18S rRNA, and phylogenetic analysis revealed the isolated metacercariae were Euclinostomum heterostomum. The histopathological study of the kidney showed hepatocyte degeneration, cytoplasmic vacuolation, and nuclear transformations. Liver fibrosis was observed in Channa punctatus. The prevalence during pre-monsoon, monsoon, and post-monsoon season ranged from 66.1% to 81.1%, abundance from 0.74 to 0.92, and intensity ranged from 1 to 1.14 using the Margolis formula. Interpretation: The study highlights the infestation of Euclinostomum heterostomum in Channa punctatus during the pre- monsoon climate appears favorable for the abundance of parasites. Hence, a proper inspection before consumption is necessary. Key words: Euclinostomum heterostomum, Infestation, Metacercariae, Parasites, Progenetic infection

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Three species of nematodes within Acrobeloides (Cobb, 1924); Thorne, 1937 (Rhabditida, Cephalobidae) were collected and recorded for the first time in Iraq, based on morphometric and molecular data, these species, A. saeedi Siddiqi, Ley & Khan, 1992, A. apiculatus (Thorne, 1925), and A. bodenheimeri (Steiner, 1936), were molecularly characterized using the partial 28S rRNA gene sequences. The phylogenetic tree has been constructed to separate Acrobeloides species from closely related species.

First Record of Alkalinema sp. (Cyanobacteria) Thermophilic Strains in Negros Oriental, Philippines

Negros Oriental in the Philippines provides a rich diversity of geothermal habitats. Despite the abundance, there are only a few published thermophile studies in the area. This study aimed to isolate thermophilic cyanobacteria from a hot spring in Negros Oriental and use morphological and molecular features for characterization and identification. Six filamentous, homocystous cyanobacteria designated as CV1, CV2, CV3, CV4, CV5, and CV6 were successfully isolated and cultured. Morphological characterization showed light green to blue-green sheathed trichomes that form an interwoven pattern similar to the recently identified cyanobacterium, Alkalinema. Partial 16S rRNA gene sequences revealed 98.58% identity of the strains with Alkalinema pantanalense DCHY213, and phylogenetic analysis placed them under the family Leptolyngbyaceae – hence forming a separate cluster from other A. pantanalense strains. The differences in ecotype and morphotype, as well as the distinct clustering in the phylogenetic tree of the Negros Oriental strains, imply the possibility of belonging to a different species. Amylase activity was detected in all strains except CV4, hence implying their potential for bioactive metabolite studies. These results highlight the importance of untapped extreme environments in the country for the discovery of novel or recently identified microorganisms that have taxonomical, ecological, and biotechnological applications.

Characterization of Erwinia amylovora isolates from the northern region of Saudi Arabia, including CRISPR genotyping

AbstractFire blight, caused by the bacterium Erwinia amylovora, poses a global threat to the pome fruit industry, leading to reduced yields and significant economic losses. A comprehensive countrywide survey was carried out to determine the possible E. amylovora distribution in pome fruit‐growing regions. During the period 2020–2023, 85 isolates characteristic of E. amylovora were obtained from pear across 23 locations in three main pear‐producing regions (Al‐Jouf, Hail and Tabuk) in northern Saudi Arabia (SA). Isolates were identified using biochemical, molecular and pathogenicity assays. Molecular characterization of Saudi strains was achieved using partial 16S rRNA and rpoB gene sequencing, rep‐PCR (specifically, BOX‐PCR) and CRISPR array analysis. The CRISPR genotyping in particular, using an existing scheme of three CRISPR arrays, CR1, CR2 and CR3, provided consistent patterns of the Saudi isolates with high similarity to those of E. amylovora strains from the UK and France, hinting at a possible origin of the fire blight infections from these countries. Some variation was observed in patterns between local strains, highlighting the importance of continued surveillance and genetic studies for effective disease management strategies. Identification of fire blight in three regions over several years should serve as a warning to the Ministry of Environment, Water and Agriculture in Saudi Arabia, prompting the initiation of a more comprehensive survey and an active disease management programme. This programme should include early detection and advice to growers on prevention and control measures. This is the first scientific study on the occurrence and genetic variability of E. amylovora in Saudi Arabia.

Study of Multiple Metal Resistant Citrobacter sp. Isolated From Industrial Effluent

The pollution of the environment with toxic heavy metals is spreading throughout the world along with industrial progress. Microbe related technologies may provide an alternative or addition to conventional method of metal removal or metal recovery. The present study deals with isolation, identification and characterization of heavy metal resistant bacteria from industrial effluent. a total58 isolates were screened for heavy metal resistant from industrial effluent. The GOZPRN isolate show multiple metal resistant and antibiotic resistances. On the basis of morphological, biochemical, partial 16S rRNA gene sequencing revealed that this isolates belongs to Citrobacter sp.. The isolate showed optimum growth at 30°C and pH 7.0. This isolate was found to be resistant to nickel (Ni), lead (Pb), zinc (Zn), Chromium (Cr). The minimal tolerance concentration (MTC) of this isolate against Cr, Ni, Pb, and Zn was 2.8 mM, 80 mM, 800 mM, and 500 mM respectively. It also exhibited resistance against tetracycline. This Citrobacter Sp. has potential to be useful for the bioremediation of heavy metals.

Characterization of Bacillus velezensis DCJ 2 isolated from the rhizosphere soil of aglaonema ‘Maria’ and investigation of its plant growth-promoting effects

Aglaonema ‘Maria’ is one of the key foliage plants that has gained high demand in foreign destinations in the last few years. This study was conducted to characterize Bacillus velezensis DCJ 2, assess its plant growth promotion effect and investigate the effectiveness of different delivery methods of the bacterial inoculum for the growth promotion of Aglaonema ‘Maria’. In this context, DCJ 2, isolated from the rhizosphere soil of A. Maria was screened to investigate its potential as a plant growth-promoting bacterium. The pure culture of DCJ 2 maintained on nutrient agar was utilized for morphological, biochemical and physiological examinations. The molecular characterization of the strain was performed with different primer pairs targeting 16SrRNA, gyrA, pgsB and sugar kinase genes of DCJ 2. A pot experiment was carried out to investigate the plant growth promotion effect. It was conducted in the greenhouse as per the complete randomized block design with eight treatments and five replicates. . Healthy plants of A. ‘Maria’ established in field soil and solarized soil were treated with 100 ml of the suspension of the DCJ 2 at the rate of 10 8 CFU/ml either as a soil drench or foliar spray. The partial 16SrRNA, gyrA, pgsB and sugar kinase gene sequences of DCJ 2, BLAST searched in the NCBI database revealed that it has a high similarity to Bacillus velezensis. The pot experiment showed that the application of strain DCJ 2 as a soil drench to solarized soil (Treatment 6) yielded a significant increase in growth parameters at p=0.05. Based on molecular analysis, morphological, biochemical, and physiological reactions, DCJ 2 was identified as Bacillus velezensis. This study revealed that B. velezensis DCJ 2 has the potential to boost the growth of A. Maria and hence serve as a base for developing a biofertilizer.

Lactobacillus paracasei Jlus66 relieves DSS-induced ulcerative colitis in a murine model by maintaining intestinal barrier integrity, inhibiting inflammation, and improving intestinal microbiota structure.

Ulcerative colitis (UC) is a serious health problem with increasing morbidity and prevalence worldwide. The pathogenesis of UC is complex, currently believed to be influenced by genetic factors, dysregulation of the host immune system, imbalance in the intestinal microbiota, and environmental factors. Currently, UC is typically managed using aminosalicylates, immunosuppressants, and biologics as adjunctive therapies, with the risk of relapse and development of drug resistance upon discontinuation. Therefore, further research into the pathogenesis of UC and exploration of potential treatment strategies are necessary to improve the quality of life for affected patients. According to previous studies, Lactobacillus paracasei Jlus66 (Jlus66) reduced inflammation and may help prevent or treat UC. We used dextran sulfate sodium (DSS) to induce a mouse model of UC to assess the effect of Jlus66 on the progression of colitis. During the experiment, we monitored mouse body weight, food and water consumption, as well as rectal bleeding. Hematoxylin-eosin staining was performed to assess intestinal pathological damage. Protein imprinting and immunohistochemical methods were used to evaluate the protein levels of nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and tight junction (TJ) proteins in intestinal tissues. Fecal microbiota was analyzed based on partial 16S rRNA gene sequencing. Jlus66 supplementation reduced the degree of colon tissue damage, such as colon shortening, fecal occult blood, colon epithelial damage, and weight loss. Supplementation with Jlus66 reduced DSS-induced upregulation of cytokine levels such as TNF-α, IL-1β, and IL-6 (p < 0.05). The NF-κB pathway and MAPK pathway were inhibited, and the expression of TJ proteins (ZO-1, Occludin, and Claudin-3) was upregulated. 16S rRNA sequencing of mouse cecal contents showed that Jlus66 effectively regulated the structure of the intestinal biota. In conclusion, these data indicate that Jlus66 can alter the intestinal biota and slow the progression of UC, providing new insights into potential therapeutic strategies for UC.

Metagenomic evaluation of peanut rhizosphere microbiome from the farms of Saurashtra regions of Gujarat, India

The narrow zone of soil around the plant roots with maximum microbial activity termed as rhizosphere. Rhizospheric bacteria promote the plant growth directly or indirectly by providing the nutrients and producing antimicrobial compounds. In this study, the rhizospheric microbiota of peanut plants was characterized from different farms using an Illumina-based partial 16S rRNA gene sequencing to evaluate microbial diversity and identify the core microbiome through culture-independent (CI) approach. Further, all rhizospheric bacteria that could grow on various nutrient media were identified, and the diversity of those microbes through culture-dependent method (CD) was then directly compared with their CI counterparts. The microbial population profiles showed a significant correlation with organic carbon and concentration of phosphate, manganese, and potassium in the rhizospheric soil. Genera like Sphingomicrobium, Actinoplanes, Aureimonas _A, Chryseobacterium, members from Sphingomonadaceae, Burkholderiaceae, Pseudomonadaceae, Enterobacteriaceae family, and Bacilli class were found in the core microbiome of peanut plants. As expected, the current study demonstrated more bacterial diversity in the CI method. However, a higher number of sequence variants were exclusively present in the CD approach compared to the number of sequence variants shared between both approaches. These CD-exclusive variants belonged to organisms that are more typically found in soil. Overall, this study portrayed the changes in the rhizospheric microbiota of peanuts in different rhizospheric soil and environmental conditions and gave an idea about core microbiome of peanut plant and comparative bacterial diversity identified through both approaches.