Pseudomonas petrae sp. nov. isolated from regolith samples in Antarctica

A polyphasic taxonomic approach was used to characterize the four strains P2653^T, P2652, P2498, and P2647, isolated from Antarctic regolith samples. Initial genotype screening performed by PCR fingerprinting based on repetitive sequences showed that the isolates studied formed a coherent cluster separated from the other Pseudomonas species. Identification results based on 16S rRNA gene sequences showed the highest sequence similarity with Pseudomonas graminis (99.7%), which was confirmed by multilocus sequence analysis using the rpoB, rpoD, and gyrB genes. Genome sequence comparison of P2653^T with the most related P. graminis type strain DSM 11363^T revealed an average nucleotide identity of 92.1% and a digital DNA-DNA hybridization value of 46.6%. The major fatty acids for all Antarctic strains were C_16:0, Summed Feature 3 (C_16:1 ω7c/C_16:1 ω6c) and Summed Feature 8 (C_18:1 ω7c/C_18:1 ω6c). The predominant respiratory quinone was Q-9, and the major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, and phosphatidylglycerol. The regolith strains could be differentiated from related species by the absence of arginine dihydrolase, ornithine and lysine decarboxylase and by negative tyrosine hydrolysis. The results of this polyphasic study allowed the genotypic and phenotypic differentiation of four analysed strains from the closest related species, which confirmed that the strains represent a novel species within the genus Pseudomonas, for which the name Pseudomonas petrae sp. nov. is proposed with P2653^T (CCM 8850^T = DSM 112068^T = LMG 30619^T) as the type strain.     

Streptomyces poriferorum sp. nov., a novel marine sponge-derived Actinobacteria species expressing anti-MRSA activity

Marine sponges represent a rich source of uncharacterized microbial diversity, and many are host to microorganisms that produce biologically active specialized metabolites. Here, a polyphasic approach was used to characterize two Actinobacteria strains, P01-B04^T and P01-F02, that were isolated from the marine sponges Geodia barretti (Bowerbank, 1858) and Antho dichotoma (Esper, 1794), respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains P01-B04^T and P01-F02 are closely related to Streptomyces beijiangensis DSM 41794^T, Streptomyces laculatispora NRRL B-24909^T, and Streptomyces brevispora NRRL B-24910^T. The two strains showed nearly identical 16S rRNA gene sequences (99.93%), and the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) relatedness values were 99.96% and 99.6%, respectively, suggesting that these strains are affiliated with the same species. Chemotaxonomic and culture characteristics of both strains were also consistent with the genus Streptomyces, while phenotypic properties, genome-based comparisons, and phylogenomic analyses distinguished strains P01-B04^T and P01-F02 from their closest phylogenetic relatives. In silico analysis predicted that the 8.9 Mb genome of P01-B04^T contains at least 41 biosynthetic gene clusters (BGCs) encoding secondary metabolites, indicating that this strain could express diverse bioactive metabolites; in support of this prediction, this strain expressed antibacterial activity against Gram-positive bacteria including a clinical isolate of methicillin-resistant Staphylococcus aureus (MRSA) EAMC30. Based on these results, the marine sponge-associated isolates represent a novel species of the genus Streptomyces, for which the name Streptomyces poriferorum sp. nov. is proposed, with P01-B04^T (=DSM 111306^T = CCM 9048^T) as the type strain.     

Weizmannia acidilactici sp. nov., a lactic acid producing bacterium isolated from soils

The strains designed PP-18^T, JC-4 and JC-7 isolated from soils, were Gram-stain-positive rods, facultative anaerobe, endospore-forming bacteria. The strains produced l-lactic acid from glucose. They showed positive for catalase but negative for oxidase, nitrate reduction and arginine hydrolysis. Strains P-18^T, JC-4 and JC-7 were closely related to Weizmannia coagulans LMG 6326^T (97.27–97.64%) and W. acidiproducens KCTC 13078^T (96.46–96.74%) based on 16S rRNA gene sequence similarity, respectively. They contained meso-diaminopimelic acid in cell wall peptidoglycan and had seven isoprene units (MK-7) as the predominant menaquinone. The major cellular fatty acids of strain PP-18^T were iso-C_15:0, anteiso-C_17:0, iso-C_16:0 and anteiso-C_15:0. The ANIb and ANIm values among the genomes of strains PP-18^T, JC-4 and JC-7 are above 99.4% while their ANIb and ANIm values among them and W. coagulans LMG 6326^T and W. acidiproducens KCTC 13078^T were ranged from 76.61 to 79.59%. These 3 strains showed the digital DNA-DNA hybridization (dDDH) values of 20.7–23.6% when compared with W. coagulans LMG 6326^T and W. acidiproducens DSM 23148^T. The DNA G + C contents of strains PP-18^T, JC-4 and JC-7 were 45.82%, 45.86% and 45.86%, respectively. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphoglycolipids. The results of phenotypic and chemotaxonomic characteristics and whole-genome analysis indicated that the strains PP-18^T, JC-4 and JC-7 should be represented as a novel species within the genus Weizmannia for which the name Weizmannia acidilactici sp. nov. is proposed. The type strain is PP-18^T (=KCTC 33974^T = NBRC 113028^T = TISTR 2515^T).     

Description of Aestuariivivens marinum sp. nov., Aestuariivivens sediminis sp. nov. and Aestuariivivens sediminicola sp. nov., three new species isolated from the upper layer of tidal flat sediment

Nine bacterial strains designated MT3-5-12^T, MT3-5-27, MTV1-9, S-DT1-15^T, S-DT1-34, MTV5-3^T, MTV4-17, MTV5-12 and MTV5-13 were isolated from the upper layer (1–5 cm in depth) of tidal flat sediment in Quanzhou Bay, China. The 16S rRNA gene of these strains shared maximum sequence similarities with Aestuariivivens insulae KCTC 42350^T of 94.9–97.1%. Phylogenetic analyses based on 16S rRNA gene sequences and 120 conserved concatenated proteins placed these strains in three novel phylogenetic clades affiliated to the genus Aestuariivivens of the family Flavobacteriaceae. Strains MT3-5-12^T, MT3-5-27 and MTV1-9 were phylogenetically close to A. insulae KCTC 42350^T. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strains MT3-5-12^Tand MTV1-9 and A. insulae KCTC 42350^T were estimated to be 78.5-78.7% and 22.5%, respectively. Strains S-DT1-15^T and S-DT1-34 formed a distinctly separated clade from A. insulae KCTC 42350^T. The ANI and dDDH values between strains S-DT1-15^T and S-DT1-34 and A. insulae KCTC 42350^T were 76.3–76.4% and 20.4–20.5%, respectively. The other four strains MTV5-3^T, MTV4-17, MTV5-12 and MTV5-13, formed a third novel clade, distinctly separated from A. insulae KCTC 42350^T. The ANI and dDDH values between strains MTV5-3^T and MTV4-17 and A. insulae KCTC 42350^T were 74.7% and 19.1–19.2%, respectively. The phylogenetic analyses and whole genomic comparisons, combined with phenotypic and chemotaxonomic features, strongly supported the nine strains could be classified as three novel species within the genus Aestuariivivens, for which the names Aestuariivivens marinum sp. nov. MT3-5-12^T, Aestuariivivens sediminis sp. nov. S-DT1-15^T, and Aestuariivivens sediminicola sp. nov. MTV5-3^T are proposed.     

Halomonas alkalisoli sp. nov., a novel haloalkalophilic species from saline-alkaline soil,and reclassification of Halomonas daqingensis Wu et al. 2008 as a later heterotypic synonym of Halomonas desiderata Berendes et al. 1996

Two Gram-stain-negative, strictly aerobic, moderately halophilic, non-spore-forming and rod-shaped bacteria, designated M5N1S17^T and M5N1S15, were isolated from saline soil in Baotou, China. A phylogenetic analysis based on 16S rRNA gene sequences showed that the two strains clustered closely with Halomonas montanilacus PYC7W^T and shared 99.1 and 99.3% sequence similarities, respectively. The average nucleotide identity based on BLAST (ANIb) and MUMmer (ANIm) values of the two strains with each other were 95.5% and 96.7%, respectively, while the ANIb and ANIm values between the two strains and 15 closer Halomonas species were 74.8–91.3% and 84.1–92.6%, respectively. The major polar lipids of M5N1S17^T are diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, and an unidentified phospholipid. The major polar lipids of M5N1S15 are diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, two unidentified phospholipids, and an unidentified lipid. The predominant ubiquinone in the two strains is Q-9. The major fatty acids of the two strains are C_18:1 ω6c and/or C_18:1 ω7c, C_16:0, and C_16:1 ω7c and/or C_16:1 ω6c. Based on phylogenetic, phenotypic, and physiological results, strains M5N1S17^T and M5N1S15 should be identified as a novel species of the genus Halomonas, for which Halomonas alkalisoli sp. nov. is proposed. The type strain is M5N1S17^T (= CGMCC 1.19023^T = KCTC 92130^T). The phylogenetic trees showed that Halomonas daqingensis CGMCC 1.6443^T clustered tightly with Halomonas desiderata FB2^T, and the two strains shared >98.0% of ANI values with each other. Therefore, we propose the reclassification of H. daqingensis Wu et al. 2008 as a later heterotypic synonym of H. desiderata Berendes et al. 1996.     

Characterization of two novel pentose-fermenting and GABA-producing species: Levilactobacillus tujiorum sp. nov. and Secundilactobacillus angelensis sp. nov. Isolated from a solid-state fermented zha-chili

Lactobacilli are dominant in zha-chili. This study provides a taxonomic characterization of five bacterial strains isolated from zha-chili in China. The cells were Gram-positive, facultative anaerobic, non-spore-forming, flagella-free, catalase-negative, heterofermentative, pentose-fermenting, and gamma-aminobutyric acid (GABA)-producing rods. For HBUAS51241^T, HBUAS51329, and HBUAS51416, C_16:0, C_18:1 ω9c and C_19:0 iso were the predominant cellular fatty acids; diphosphatidylglycerol (DPG), phosphatidylglycerol (DP), glycolipids (GL), and glycolipids (AL) were the major phospholipids. While for HBUAS51383^T and HBUAS58055, C_16:0, C_18:1 ω9c, C_19:0 cyclo ω8c were the predominant cellular fatty acids; DPG, DP, GL, and AL were the major phospholipids. Strains HBUAS51241^T, HBUAS51329, and HBUAS51416 showed 98.1–99.1% 16S rRNA gene sequence similarity, 80.2–81.4% ANI, 87.7–90.0% AAI, and 23.8–32.8% digital DDH to their closest related type strains Levilactobacillus hammesii DSM 16381^T, Levilactobacillus parabrevis ATCC 53295^T, and Levilactobacillus fuyuanensis 244-4^T. Strains HBUAS51383^T and HBUAS58055 showed 98.7–99.5% 16S rRNA gene sequence similarity, 75.4–81.4% ANI, 75.5–89.1% AAI, and 19.7–24.0% digital DDH to their closest related type strains Secundilactobacillus silagincola IWT5^T, Secundilactobacillus silagei JCM 19001^T, Secundilactobacillus pentosiphilus IWT25^T, Secundilactobacillus mixtipabuli IWT30^T, Secundilactobacillus odoratitofui DSM 19909^T, and Secundilactobacillus similis DSM 23365^T. The central carbon metabolism pathways for the five strains were summarizeded. Based on the phenotypic, chemotaxonomic, and genomic data, we propose two novel species Levilactobacillus tujiorum sp. nov. whose type strain is HBUAS51241^T (=GDMCC 1.3022^T = JCM 35241^T), and Secundilactobacillus angelensis sp. nov. whose type strain is HBUAS51383^T (=GDMCC 1.3021^T = JCM 35209^T).     

Migratory birds as the vehicle of transmission of multi drug resistant extended spectrum β lactamase producing Escherichia fergusonii,an emerging zoonotic pathogen

The acquisition of multi-drug resistance (MDR) genes by pathogenic bacterial bugs and their dispersal to different food webs has become a silent pandemic. The multiplied use of different antibacterial therapeutics during COVID-19 pandemic has accelerated the process among emerging pathogens. Wild migratory birds play an important role in the spread of MDR pathogens and MDR gene flow due to the consumption of contaminated food and water. Escherichia fergusonii is an emerging pathogen of family Enterobacteriaceae and commonly causes disease in human and animals. The present study focused on the isolation of E. fergusonii from blood, saliva, and intestine of selected migratory birds of the Hazara Division. The sensitivity of isolated strains was assessed against ten different antibiotics. The isolation frequency of E. fergusonii was 69%. In blood samples, a high rate of resistance was observed against ceftriaxone (80%) followed by ampicillin (76%) whereas, in oral and intestinal samples, ceftriaxone resistant strains were 56% and 57% while ampicillin resistance was 49% and 52% respectively. The overall ceftriaxone and ampicillin-resistant cases in all three sample sources were 71% and 65% respectively. In comparison to oral and intestinal samples, high numbers of ceftriaxone-resistant strains were isolated from the blood of mallard while ampicillin-resistant strains were observed in blood samples of cattle egrets. 16S rRNA-based confirmed strains of E. fergusonii were processed for detection of CTX-M and TEM-1 gene through Polymerase chain reaction (PCR) after DNA extraction. Hundred percent ceftriaxone resistant isolates possessed CTX-M and all ampicillin-resistant strains harbored TEM-1 genes. Amplified products were sequenced by using the Sanger sequencing method and the resulted sequences were checked for similarity in the nucleotide Database through the BLAST program. TEM-1 gene showed 99% and the CTX-M gene showed 98% similar sequences in the Database. The 16S rRNA sequence and nucleotide sequences for TEM-1 and CTX-M genes were submitted to Gene Bank with accession numbers LC521304, LC521306, LC521307 respectively. We posit to combat MDR gene flow among the bacterial pathogens across different geographical locations, regular surveillance of new zoonotic pathogens must be conducted.     

Magnetospirillum sulfuroxidans sp. nov., capable of sulfur-dependent lithoautotrophy and a taxonomic reevaluation of the order Rhodospirillales

A spiral-shaped, highly motile bacterium was isolated from freshwater sulfidic sediment. Strain J10^T is a facultative autotroph utilizing sulfide, thiosulfate, and sulfur as the electron donors in microoxic conditions. Despite high 16S rRNA gene sequence sequence identity to Magnetospirillum gryphiswaldense MSR-1 ^T (99.6 %), digital DNA-DNA hybridisation homology and average nucleotide identity between the two strains was of the different species level (25 % and 83 %, respectively). Strain J10^T is not magnetotactic. The DNA G + C content of strain J10^T is 61.9 %. The predominant phospholipid ester-linked fatty acids are C18:1ω7, C16:1ω7, and C16:0. Strain J10^T (=DSM 23205 ^T = VKM B-3486 ^T) is the first strain of the genus Magnetospirillum showing lithoautotrophic growth and is proposed here as a novel species, Magnetospirillum sulfuroxidans sp. nov. In addition, we propose to establish a framework for distinguishing genera and families within the order Rhodospirillales based on phylogenomic analysis using the threshold values for average amino acid identity at ̴ 72 % for genera and ̴ 60 % for families. According to this, we propose to divide the existing genus Magnetospirillum into three genera: Magnetospirillum, Paramagnetospirillum, and Phaeospirillum, constituting a separate family Magnetospirillaceae fam. nov. in the order Rhodospirillales. Furthermore, phylogenomic data suggest that this order should accomodate six more new family level groups including Magnetospiraceae fam. nov., Magnetovibrionaceae fam. nov., Dongiaceae fam. nov., Niveispirillaceae fam. nov., Fodinicurvataceae fam. nov., and Oceanibaculaceae fam. nov.     

Anti-salmonella properties of kefir yeast isolates: An in vitro screening for potential infection control

The rise of antibiotic resistance has increased the need for alternative ways of preventing and treating enteropathogenic bacterial infection. Various probiotic bacteria have been used in animal and human. However, Saccharomyces boulardii is the only yeast currently used in humans as probiotic. There is scarce research conducted on yeast species commonly found in kefir despite its claimed potential preventative and curative effects. This work focused on adhesion properties, and antibacterial metabolites produced by Kluyveromyces lactis and Saccharomyces unisporus isolated from traditional kefir grains compared to Saccharomyces boulardii strains. Adhesion and sedimentation assay, slide agglutination, microscopy and turbidimetry assay were used to analyze adhesion of Salmonella Arizonae and Salmonella Typhimurium onto yeast cells. Salmonella growth inhibition due to the antimicrobial metabolites produced by yeasts in killer toxin medium was analyzed by slab on the lawn, turbidimetry, tube dilution and solid agar plating assays. Alcohol and antimicrobial proteins production by yeasts in killer toxin medium were analyzed using gas chromatography and shotgun proteomics, respectively. Salmonella adhered onto viable and non-viable yeast isolates cell wall. Adhesion was visualized using scanning electron microscope. Yeasts-fermented killer toxin medium showed Salmonella growth inhibition. The highest alcohol concentration detected was 1.55%, and proteins with known antimicrobial properties including cathelicidin, xanthine dehydrogenase, mucin-1, lactadherin, lactoperoxidase, serum amyloid A protein and lactotransferrin were detected in yeasts fermented killer medium. These proteins are suggested to be responsible for the observed growth inhibition effect of yeasts-fermented killer toxin medium. Kluyveromyces lactis and Saccharomyces unisporus have anti-salmonella effect comparable to Saccharomyces boulardii strains, and therefore have potential to control Salmonella infection.     

Phenotypic and molecular analysis of dominant occurring antibiotic active-producing Streptomyces soil flora in Northern Jordan

This investigation aimed to determine the relatedness of dominant occurring soil Streptomyces spp. in Northern Jordan based on their RAPD-PCR fingerprints, and to compare RAPD technique with the conventional phenotypic characterization of Streptomyces isolates. Fifty-eight white and gray color-bearing aerial mycelia antibiotic active-producing Streptomyces soil isolates along with three reference strains were genetically analyzed by RAPD-PCR. Polymorphisms between the isolates showed 1 to 10 bands per isolate and ranged from 200 to 3200 bp in size. Results revealed one common band of ~600 bp shared by ~85% of the isolates, and the observation of bands specific to some reference strains and some soil isolates. When RAPD patterns were analyzed with the UPGMA, results revealed clustering the tested isolates into two equal main super clusters (50% each). Super cluster I appeared to be homogenous and include the three reference strains. However, super cluster II was heterogeneous and but not including any of the reference strains. The association of the antibiotic activity of the dominant white and gray aerial mycelium-bearing Streptomyces isolates to RAPD clustering is reported for the first time, and the RAPD-PCR fingerprints generated here deserve to be cloned, characterized and sequenced in future as Streptomyces species-specific DNA markers. The more random primers used in the analysis may add to RAPD technique a cost-effective, fast, precise result, and less labor work solution for analyzing the similarities and differences among the Streptomyces isolates.     

Govania unica gen. nov., sp. nov., a rare biosphere bacterium that represents a novel family in the class Alphaproteobacteria

Strain LMG 31809 ^T was isolated from a top soil sample of a temperate, mixed deciduous forest in Belgium. Comparison of its 16S rRNA gene sequence with that of type strains of bacteria with validly published names positioned it in the class Alphaproteobacteria and highlighted a major evolutionary divergence from its near neighbor species which represented species of the orders Emcibacterales and Sphingomonadales. 16S rRNA amplicon sequencing of the same soil sample revealed a highly diverse community in which Acidobacteria and Alphaproteobacteria predominated, but failed to yield amplicon sequence variants highly similar to that of strain LMG 31809 ^T. There were no metagenome assembled genomes that corresponded to the same species and a comprehensive analysis of public 16S rRNA amplicon sequencing data sets demonstrated that strain LMG 31809 ^T represents a rare biosphere bacterium that occurs at very low abundances in multiple soil and water-related ecosystems. The genome analysis suggested that this strain is a strictly aerobic heterotroph that is asaccharolytic and uses organic acids and possibly aromatic compounds as growth substrates. We propose to classify LMG 31809 ^T as a novel species within a novel genus, Govania unica gen. nov., sp. nov, within the novel family Govaniaceae of the class Alphaproteobacteria. Its type strain is LMG 31809 ^T (=CECT 30155 ^T). The whole-genome sequence of strain LMG 31809 ^T has a size of 3.21 Mbp. The G + C content is 58.99 mol%. The 16S rRNA gene and whole-genome sequences of strain LMG 31809 ^T are publicly available under accession numbers OQ161091 and JANWOI000000000, respectively.     

Halonatronomonas betaini gen. nov., sp. nov., a haloalkaliphilic isolate from soda lake capable of betaine degradation and proposal of Halarsenatibacteraceae fam. nov. and Halothermotrichaceae fam. nov. within the order Halanaerobiales

A search for the organisms responsible for anaerobic betaine degradation in soda lakes resulted in isolation of a novel bacterial strain, designated Z-7014^T. The cells were Gram-stain-negative, non-endospore-forming rods. Growth occurred at 8–52 °C (optimum 40–45 °C), pH 7.1–10.1 (optimum pH 8.1–8.8) and 1.0–3.5 M Na⁺ (optimum 1.8 M), i.e. it can be regarded as a haloalkaliphile. The strain utilized a limited range of substrates, mostly peptonaceous but not amino acids, and was able to degrade betaine. Growth on betaine occurred only in the presence of peptonaceous substances which could not be replaced by vitamins. The G + C content of the genomic DNA of strain Z-7014^T was 36.1 mol%. The major cellular fatty acids (>5% of the total) were C_16:0 DMA, C_{18: 0} DMA, C_16:1ω8, C_16:0, C_18:1 DMA, C_16:1 DMA, C_18:1ω9, and C_18:0. Phylogenetic analysis of the 16S rRNA gene sequence revealed that strain Z-7014^T formed a distinct evolutionary lineage in the order Halanaerobiales with the highest similarity to Halarsenitibacter silvermanii SLAS-1^T (83.6%), Halothermothrix orenii H168^T (85.6%), and Halocella cellulosilytica DSM 7362^T (85.6%). AAI and POCP values between strain Z-7014^T and type strains of the order Halanaerobiales were 51.7–57.8%, and 33.8–58.3%, respectively. Based on polyphasic results including phylogenomic data, the novel strain could be distinguished from other genera, which suggests that strain Z-7014^T represents a novel species of a new genus, for which the name Halonatronomonas betaini gen. nov., sp. nov. is proposed. The type strain is Z-7014^T (=KCTC 25237^T = VKM B-3506^T). On the basis of phylogenomic data, it is also proposed to evolve two novel families Halarsenitibacteraceae fam. nov. and Halothermotrichaceae fam. nov. within the current order Halanaerobiales.     

Isolation and characterization of lytic bacteriophages from sewage at an egyptian tertiary care hospital against methicillin-resistant Staphylococcus aureus clinical isolates

BackgroundMethicillin resistant Staphylococcus aureus (MRSA) is a pathogen to humans causing life-threatening infections. MRSA have the capability to grow resistance to many antibiotics, and phage therapy is one treatment option for this infection.ObjectivesThe aim of the present study was to isolate and characterize the lytic bacteriophages specific to MRSA from domestic sewage water at a tertiary care hospital in Egypt.MethodsThirty MRSA strains were isolated from different clinical samples admitted to the microbiology lab at Theodor Bilharz Research institute (TBRI) hospital, Giza, Egypt. They were confirmed to be MRSA through phenotypic detection and conventional PCR for mecA gene. They were used for the isolation of phages from sewage water of TBRI hospital. Plaque assay was applied to purify and quantify the titer of the isolated phages. The host range of the isolated phages was detected using the spot test assay. The morphology of phages was confirmed using transmission electron microscope (TEM). Digestion of DNA extracted from phages with endonuclease enzymes including EcoRI and SmaI was performed. SDS-PAGE was performed to analyze MRSA specific phage proteins. As a positive control prophages were isolated from a mitomycin C (MitC) treated culture of S. aureus strain ATCC25923. Further characterization using conventional polymerase chain reaction (PCR) was used to select three known Staphylophages by detecting the endolysin gene of phage K, the polymerase gene of phage 44AHJD, and the minor tail gene of phage P68.ResultsIsolated phages in this research displayed a wide host range against MRSA using the spot test, out of thirty tested MRSA isolates 24 were sensitive and got lysed (80%). The titer of the phages was estimated to be 1.04 × 10⁶ pfu/ml using plaque test. Identification of head and tail morphology of the phages was achieved using TEM and they were designated to tailed phages of order Caudovirales, they composed an icosahedral capsid. Prophages were isolated through MitC induction. DNA of phages was digested by endonuclease enzymes. Conventional PCR yielded 341 bp of phage K endolysin gene and phage P68 minor tail protein gene 501 bp. Protein analysis using SDS-PAGE showed 4 proteins of sizes between 42 kDa and 140 kDa.ConclusionPhages isolated here are alike to others mentioned in previous studies. The high broad host range of the isolated phages is promising to control MRSA and can be in the future commercially suitable for treatment as lysate preparations. Animal models of phage-bacterial interaction will be our next step that may help in resolving the multidrug resistant crisis of MRSA in Egypt.     

Genotypic and phenotypic characterization of industrial autochthonous Saccharomyces cerevisiae for the selection of well-adapted bioethanol-producing strains

In northwestern Argentina, sugarcane-derived industrial fermentation is being extensively used for bioethanol production, where highly adaptive native strains compete with the baker's yeast Saccharomyces cerevisiae traditionally used as starter culture. Yeast populations of 10 distilleries from Tucumán (Argentina) were genotypic and phenotypic characterized to select well-adapted bioethanol-producing autochthonous strains to be used as starter cultures for the industrial production of bioethanol fuel. From the 192 isolates, 69.8% were identified as S. cerevisiae, 25.5% as non-Saccharomyces, and 4.7% as Saccharomyces sp. wild yeasts. The majority of S. cerevisiae isolates (68.5%) were non-flocculating yeasts, while the flocculating strains were all obtained from the only continuous fermentation process included in the study. Simple Sequence Repeat analysis revealed a high genetic diversity among S. cerevisiae genotypes, where all of them were very different from the original baker's strain used as starter. Among these, 38 strains multi-tolerant to stress by ethanol (8%), temperature (42.5 °C) and pH (2.0) were obtained. No major differences were found among these strains in terms of ethanol production and residual sugars in batch fermentation experiments with cell recycling. However, only 10 autochthonous strains maintained their viability (more than 80%) throughout five consecutive cycles of sugarcane-based fermentations. In summary, 10 autochthonous isolates were found to be superior to baker's yeast used as starter culture (S. cerevisiae Calsa) in terms of optimal technological, physiological and ecological properties. The knowledge generated on the indigenous yeast populations in industrial fermentation processes of bioethanol-producing distilleries allowed the selection of well-adapted bioethanol-producing strains.     

Rhodopirellula aestuarii sp. nov., a novel member of the genus Rhodopirellula isolated from brackish sediments collected in the Tagus River estuary,Portugal

Bacteria within the phylum Planctomycetota are biologically relevant due to unique characteristics among prokaryotes. Members of the genus Rhodopirellula can be abundant in marine habitats, however, only six species are currently validly described. In this study, we expand the explored genus diversity by formally describing a novel species. The pink-coloured strain ICT_H3.1^T was isolated from brackish sediments collected in the Tagus estuary (Portugal) and a 16S rRNA gene sequence-based analysis placed this strain into the genus Rhodopirellula (family Pirellulaceae). The closest type strain is Rhodopirellula rubra LF2^T, suggested by a similarity of 98.4% of the 16S rRNA gene sequence. Strain ICT_H3.1^T is heterotrophic, aerobic and able to grow under microaerobic conditions. The strain grows between 15 and 37 °C, over a range of pH 6.5 to 11.0 and from 1 to 8% (w/v) NaCl. Several nitrogen and carbon sources were utilized by the novel isolate. Cells have an elongated pear-shape with 2.0 ± 0.3 × 0.9 ± 0.2 µm in size. Cells of strain ICT_H3.1^T cluster in rosettes through a holdfast structure and divide by budding. Younger cells are motile. Ultrathin cell sections show cytoplasmic membrane invaginations and polar fimbriae. The genome size is 9,072,081 base pairs with a DNA G + C content of 56.1 mol%. Genomic, physiological and morphological comparison of strain ICT_H3.1^T with its relatives suggest that it belongs to a novel species within the genus Rhodopirellula. Hence, we propose the name Rhodopirellula aestuarii sp. nov., represented by ICT_H3.1^T (=CECT30431^T = LMG32464^T) as the type strain of this novel species.16S rRNA gene accession number: GenBank = OK001858.Genome accession number: The Whole Genome Shotgun project has been deposited at DDBJ/ENA/GenBank under the accession JAMQBK000000000. The version described in this paper is version JAMQBK010000000.     

Bacillus strain selection with plant growth-promoting mechanisms as potential elicitors of systemic resistance to gray mold in pepper plants

Certain soil bacteria produce beneficial effects on the growth and health of plants; hence, their use is steadily increasing. Five strains of Bacillus with plant growth-promoting potential were selected in this study, which produced indole-3-acetic acid levels below 50 µg.mL⁻¹. On the other hand, while only strains M8 and M15 dissolved phosphorus, the latter was the only strain that did not produce siderophores. Only strains M8 and M16 significantly inhibited the in vitro growth of Botrytis cinerea and Fusarium solani phytopathogens, whose inhibition ranges fluctuated between 60% and 63% for strains M8 and M16 against B. cinerea and between 40% and 53% for strains M8 and M16 against F. solani. Based on these results, the need to implement resistance induction against gray mold on pepper plants was determined using strains M8 and M16. In this case, strain M16 inhibited the propagation of the necrotic spot by approximately 70%, whereas strain M8 significantly reduced the superoxide dismutase activity in systemic leaves, which substantially increased in plants inoculated with strain M8 and infected with the pathogen. Accordingly, the use of native rhizobacteria may entail biotechnological progress for the integrated management of crops in agriculture industry.     

Molecular detection and phylogenetic analyses of Arsenophonus endosymbiont in wild specimens of phlebotomine sand flies from Colombia

Endosymbionts have gained prominence as a potential tool for biological control strategies in reducing vector-borne diseases. This study aimed to evaluate the presence of Arsenophonus, Spiroplasma, and Rickettsia endosymbionts in wild specimens of phlebotomine sand flies, as well as in culicids collected in different regions of Colombia. Analyses were conducted through conventional PCR, Sanger sequencing of the 16S rRNA gene, and phylogenetic analyses. Individuals from among 946 phlebotomine sand flies and 143 mosquitoes were selected for taxonomic identification confirmed through the analysis of the cytochrome oxidase subunit I gene sequences. Results showed the presence of Arsenophonus bacteria in samples of Lutzomyia longipalpis, Psychodopygus panamensis, and Pintomyia evansi. Arsenophonus sequences associated with Lu. longipalpis and Ps. panamensis are phylogenetically located near to sequences of louse flies, with K2P genetic distances of 0.006. In contrast, sequences obtained from Pi. evansi are phylogenetically located near Arsenophonus nasoniae (K2P 0.001–0.014). Other sequences of endosymbionts similar to Arsenophonus with high K2P genetic distances (0.056–0.097), when compared to different reference strains of this endosymbiont, were also found in other samples of Lu. longipalpis and Ae. aegypti. To the best of our knowledge, this is the first successful attempt to detect and elucidate the phylogenetic relationship of Arsenophonus in phlebotomine sand flies, yet its role within these insect vectors remains to be fully determined; therefore, the importance of entomological surveys that help better understand its behavior and potential use as a control agent is required to enable the proactive reduction of sand fly populations.