Quorum sensing activity of Aeromonas caviae strain YL12, a bacterium isolated from compost

Aeromonas salmonicida AI-1 and AI-2 quorum sensing pathways are differentially regulated by rainbow trout mucins and during in vivo colonization

Aeromonas salmonicida is an opportunistic pathogen with relevance for aquaculture. Fish epithelia are covered by a mucus layer, composed mainly by highly glycosylated mucins, which are the first point of contact between fish and pathogens. Quorum sensing (QS), a bacterial communication mechanism through secreted autoinducer signals that governs gene expression, influences bacterial growth and virulence. The main A. salmonicida autoinducers are mediated by the luxS and asaI genes, corresponding to inter- and intraspecies communication, respectively. The aim of this study was to determine the effect of the mucins that pathogens encounter during colonization of the gill and skin on A. salmonicida QS. We found that expression of A. salmonicida asaI, but not luxS, was increased after culture at 20 °C compared to 10 °C. Rainbow trout gill and skin mucins up-regulated asaI expression 2-fold but down-regulated luxS 10-fold. The downregulation of luxS was reflected by a reduction in autoinducer-2 secretion. Mucins isolated from skin had a stronger inhibitory effect than mucins isolated from gills on both luxS expression and A1-2 secretion, consistent with a higher relative abundance of N-Acetylneuraminic acid on skin mucins than on gill mucins. Reduction of AI-2 production by mucins or luxS-deletion lead to a reduced A. salmonicida auto-aggregation. Furthermore, after colonization of the gill, luxS was down regulated whereas asaI expression was upregulated. Both in vivo and in vitro, the expression of luxS and asaI were thus differentially regulated, frequently in an inverse manner. The strong AI-2 inhibiting effect of the skin mucins is likely part of the mucin-based defense against pathogens.

Comparison of in vitro Antifungal Activity Methods Using Extract of Chitinase-producing Aeromonas sp. BHC02

Biological control to prevent fungal plant diseases offers an alternative approach to facilitate sustainable agriculture. Since the chitin in fungal cell walls is a target for biocontrol agents, chitinases are one of the important antifungal molecules. In this study, the aim was to investigate a new chitinase isolated from a fluvial soil bacterium and to show the antifungal activity of the characterized chitinase by comparing the three common methods. The bacterium with the highest chitinase activity was identified as Aeromonas sp. by 16 S rRNA sequence analysis. Following the determination of the optimum enzyme production time, the enzyme was partially purified, and the physicochemical parameters of the enzyme were investigated. In the antifungal studies, direct Aeromonas sp. BHC02 cells or partially purified chitinase were used. As a result, in the first method in which the Aeromonas sp. BHC02 cells were spread on the surface of petri dishes, no zone formation was observed around the test fungi spotted on the surface. However, zone formation was observed in the methods in which the antifungal activity was investigated using the partially purified chitinase enzyme. For example, in the second method, the enzyme was spread on the surface of PDA, and zone formation was observed only around Penicillum species among the test fungi spotted on the surface. In the third method, in which the necessary time was given for the formation of mycelium of the test fungi, it was observed that the growth of Fusarium solani, Alternaria alternata and Botrytis cinerea was inhibited by the partially purified chitinase. This study concludes that the results of the antifungal activities depend on the method used and all fungal chitins cannot be degraded with one strain's chitinase. Depending on the variety of chitin, some fungi can be more resistant.

Isolation, Identification and Characteristics of Aeromonas caviae from Diseased Largemouth Bass (Micropterus salmoides)

The largemouth bass (Micropterus salmoides) is one of the most economically valuable fish species in China. In this study, a bacterial pathogen was isolated from the internal organs of diseased M. salmoides, and the strain was named WH21406. This isolate was identified as Aeromonas caviae on the basis of its morphology, biochemical features and 16S rDNA phylogenetic analysis. Four virulence genes related to pathogenicity, namely, flagella (fla), elastase (ela), haemolysin (hly) and aerolysin (aer), were detected in this isolate. The median lethal dosage (LD50) of A. caviae WH21406 for M. salmoides was calculated to be 3.46 × 105 CFU mL−1. The histopathological analysis showed obvious tissue damage in the gill, liver, kidney, spleen and gut of the diseased fish. The antibiotic susceptibility test demonstrated that strain WH21406 was highly sensitive to enrofloxacin, norfloxacin, streptomycin and amikacin. The results of this study provide a foundation for the diagnosis, prevention and treatment of A. caviae infection in M. salmoides.

Metagenomic Insights Into the Changes of Antibiotic Resistance and Pathogenicity Factor Pools Upon Thermophilic Composting of Human Excreta

In times of climate change, practicing a form of sustainable, climate-resilient and productive agriculture is of primordial importance. Compost could be one form of sustainable fertilizer, which is increasing humus, water holding capacity, and nutrient contents of soils. It could thereby strengthen agriculture toward the adverse effects of climate change, especially when additionally combined with biochar. To get access to sufficient amounts of suitable materials for composting, resources, which are currently treated as waste, such as human excreta, could be a promising option. However, the safety of the produced compost regarding human pathogens, pharmaceuticals (like antibiotics) and related resistance genes must be considered. In this context, we have investigated the effect of 140- and 154-days of thermophilic composting on the hygienization of human excreta and saw dust from dry toilets together with straw and green cuttings with and without addition of biochar. Compost samples were taken at the beginning and end of the composting process and metagenomic analysis was conducted to assess the fate of antibiotic resistance genes (ARGs) and pathogenicity factors of the microbial community over composting. Potential ARGs conferring resistance to major classes of antibiotics, such as beta-lactam antibiotics, vancomycin, the MLS_B group, aminoglycosides, tetracyclines and quinolones were detected in all samples. However, relative abundance of ARGs decreased from the beginning to the end of composting. This trend was also found for genes encoding type III, type IV, and type VI secretion systems, that are involved in pathogenicity, protein effector transport into eukaryotic cells and horizontal gene transfer between bacteria, respectively. The results suggest that the occurrence of potentially pathogenic microorganisms harboring ARGs declines during thermophilic composting. Nevertheless, ARG levels did not decline below the detection limit of quantitative PCR (qPCR). Thresholds for the usage of compost regarding acceptable resistance gene levels are yet to be evaluated and defined.

Growth-Stimulatory Effect of Quorum Sensing Signal Molecule N-Acyl-Homoserine Lactone-Producing Multi-Trait Aeromonas spp. on Wheat Genotypes Under Salt Stress

Salinity is one of the major threats to agricultural productivity worldwide. Soil and plant management practices, along with inoculation with plant-beneficial bacteria, play a key role in the plant’s tolerance toward salinity stress. The present study demonstrates the potential of acyl homoserine lactone (AHL)-producing plant growth promoting rhizobacteria (PGPR) strains of Aeromonas sp., namely, SAL-17 (accession no. HG763857) and SAL-21 (accession no. HG763858), for growth promotion of two wheat genotypes inherently different for salt tolerance potential. AHLs are the bacterial signal molecules that regulate the expression of various genes in bacteria and plants. Both Aeromonas spp., along with innate plant-growth-promoting (PGP) and salt tolerance traits, showed AHL production which was identified on tandem mass spectrometry as C6-HSL, 3-OH-C5-HSL, 3-OH-C6-HSL, 3-oxo-C7-HSL C10-HSL, 3-oxo-C10-HSL, 3-OH-C10-HSL, 3-oxo-C12-HSL and C6-HSL, and 3-oxo-C10-HSL. The exogenous application of purified AHLs (mix) significantly improved various root parameters at 200 mM NaCl in both salt-sensitive (SSG) and salt-tolerant (STG) genotypes, where the highest increase (≈80%) was observed where a mixture of both strains of AHLs was used. Confocal microscopic observations and root overlay assay revealed a strong root colonization potential of the two strains under salt stress. The inoculation response of both STG and SSG genotypes was evaluated with two AHL-producing strains (SAL-17 and SAL-21) and compared to non-AHL-producing Aeromonas sp. SAL-12 (accession no. HG763856) in saline (EC = 7.63 ms/cm²) and non-saline soil. The data reveal that plants inoculated with the bacterial consortium (SAL-21 + SAL-17) showed a maximum increase in leaf proline content, nitrate reductase activity, chlorophyll a/b, stomatal conductance, transpiration rate, root length, shoot length, and grain weight over non-inoculated plants grown in saline soil. Both STG and SSG showed relative effectiveness toward inoculation (percent increase for STG: 165–16%; SSG: 283–14%) and showed a positive correlation of grain yield with proline and nitrate reductase activity. Furthermore, principal component analysis (PCA) and categorical PCA analysis clearly showed an inoculation response in both genotypes, revealing the effectiveness of AHL-producing Aeromonas spp. than the non-AHL-producing strain. The present study documents that the consortium of salt-tolerant AHL-producing Aeromonas spp. is equally effective for sustaining the growth of STG as well as SSG wheat genotypes in saline soil, but biosafety should be fully ensured before field release.

Occurrence of diversified N-acyl homoserine lactone mediated biofilm-forming bacteria in rice rhizoplane

Quorum sensing (QS)-mediated biofilm-forming rhizobacteria are indispensable due to their competitiveness in the crop rhizosphere. In the present work, we have reported on the occurrence of diversified bacterial species capable of producing N-acyl homoserine lactone (AHL) as the QS signal in the roots of a rice plant grown under field conditions. The AHL-producing bacteria were directly isolated from the rice root by the biosensor reporter (Chromobacterium violaceum CV026) overlay method and characterized for biofilm production by the microtiter plate method. A total of 48 QS-positive bacterial isolates were purified from different aged (7, 20, 24, 26, and 36 days) rice seedlings. The in vitro biofilm production and genetic diversity as revealed by BOX-PCR fingerprinting showed high variability among the isolates. Most of the best biofilm-forming isolates produced a N-butyryl dl-homoserine lactone (a C4-AHL type) signal in the medium. The 16S ribosomal RNA (rRNA) gene sequence of these putative elite isolates identified that they were close to Aeromonas hydrophila (QS7-4; QS36-2), A. enteropelongenes (QS20-8), A. veronii (QS36-3), Enterobacter sp. (QS20-11), Klebsiella pneumoniae (QS24-6), Kosakonia cowanii (QS24-21), Providentia rettigeri (QS24-2), Sphingomonas aquatilis (QS24-17), and Pseudomonas sihuiensis (QS24-20). These strains profusely colonized the rice root upon inoculation and formed biofilms on the surface of the root under gnotobiotic conditions. Developing inoculants from these strains would ensure competitive colonization on the rhizoplane of the crop through their biofilm and thereby improve plant growth and health.

Purinergic signalling displays an anti-inflammatory profile in the spleen of fish experimentally infected with Aeromonas caviae: Modulation of the immune response

Extracellular adenosine triphosphate (ATP) and its metabolite adenosine (Ado) are recognized as key mediators of immune and inflammatory responses. Depending on its concentration, ATP may act as an immunostimulant or immunodepressant, while Ado levels display an anti-inflammatory profile. The aim of this study was to evaluate whether splenic purinergic signalling is capable of modulating immune and inflammatory responses in fish experimentally infected with Aeromonas caviae. Triphosphate diphosphohydrolase (NTPDase) and 5'-nucleotidase activities increased in the spleen of silver catfish (Rhamdia quelen) experimentally infected with A. caviae compared with the uninfected control group. Moreover, splenic Ado levels increased in the infected animals relative to the uninfected control group. Based on these lines of evidence, our findings revealed that adenine nucleotide hydrolysis is modified in the spleen of fish infected with A. caviae attempting to restrict the inflammatory process through the upregulation of NTPDase and 5'-nucleotidase activities, which occurs in an attempt to hydrolyse the excessive ATP in the extracellular environment and rapidly hydrolyse AMP to form Ado. In summary, purinergic signalling can modulate immune and inflammatory responses during A. caviae infection.

Aeromonas caviae inhibits hepatic enzymes of the phosphotransfer network in experimentally infected silver catfish: Impairment on bioenergetics

Several studies have been demonstrated that phosphotransfer network, through the adenylate kinase (AK) and pyruvate kinase (PK) activities, allows for new perspectives leading to understanding of disease conditions associated with disturbances in energy metabolism, metabolic monitoring and signalling. In this sense, the aim of this study was to evaluate whether experimental infection by Aeromonas caviae alters hepatic AK and PK activities of silver catfish Rhamdia quelen. Hepatic AK and PK activities decreased in infected animals compared to uninfected animals, as well as the hepatic adenosine triphosphate (ATP) levels. Also, a severe hepatic damage was observed in the infected animals due to the presence of dilation and congestion of vessels, degeneration of hepatocytes and loss of liver parenchyma architecture and sinusoidal structure. Therefore, we have demonstrated, for the first time, that experimental infection by A. caviae inhibits key enzymes linked to the communication between sites of ATP generation and ATP utilization. Moreover, the absence of a reciprocal compensatory mechanism between these enzymes contributes directly to hepatic damage and for a severe energetic imbalance, which may contribute to disease pathophysiology.

The first report on Listeria monocytogenes producing siderophores and responds positively to N-acyl homoserine lactone (AHL) molecules by enhanced biofilm formation

Listeria monocytogenes are Gram-positive well-known emerging food-borne pathogens causing listeriosis in humans. In the present study, we have isolated biofilm-forming Listeria sp. from utensils used by a local milk collection dairy society at Usgao Goa, which collects milk for Goa dairy. Through biochemical tests and 16S rRNA sequence analysis, the bacterium was confirmed to be L. monocytogenes and designated as strain BN3, having GenBank accession number MF095110. We report for the first time Gram-positive L. monocytogenes strain BN3 producing iron-chelating siderophores by chrome azurol S (CAS) agar test. Also, this is a first report which reveals that L. monocytogenes strain BN3 responds to N-hexanoyl-homoserine lactone molecule (C₆-HSL) by gradual increase in their biofilm-forming potential with a gradual increase in AHL (C₆-HSL) concentration (250, 500 nM-1 μM) as compared to control revealed by crystal violet assay (CV) in microtiter plate. These results were further confirmed by scanning electron microscopy (SEM). A significant decrease in biofilm formation was observed when L. monocytogenes strain BN3 was treated with 10 µg/ml (R)-2-(2-hydroxynaphthalen-1-yl)thiazolidine-4-carboxylic acid, but when 250 and 500 nM AHL molecules were added, biofilm formation in strain BN3 was found to be enhanced as compared to control even in the presence of antibacterial compound, (R)-2-(2-hydroxynaphthalen-1-yl)thiazolidine-4-carboxylic acid. These results revealed that AHL molecules nullify the effect of antimicrobial compound and promote biofilm formation in L. monocytogenes strain BN3.

The Social Life of Aeromonas through Biofilm and Quorum Sensing Systems

Bacteria of the genus Aeromonas display multicellular behaviors herein referred to as “social life”. Since the 1990s, interest has grown in cell-to-cell communication through quorum sensing signals and biofilm formation. As they are interconnected, these two self-organizing systems deserve to be considered together for a fresh perspective on the natural history and lifestyles of aeromonads. In this review, we focus on the multicellular behaviors of Aeromonas, i.e., its social life. First, we review and discuss the available knowledge at the molecular and cellular levels for biofilm and quorum sensing. We then discuss the complex, subtle, and nested interconnections between the two systems. Finally, we focus on the aeromonad multicellular coordinated behaviors involved in heterotrophy and virulence that represent technological opportunities and applied research challenges.

Characterization and Comparative Overview of Complete Sequences of the First Plasmids of Pandoraea across Clinical and Non-clinical Strains

To date, information on plasmid analysis in Pandoraea spp. is scarce. To address the gap of knowledge on this, the complete sequences of eight plasmids from Pandoraea spp. namely Pandoraea faecigallinarum DSM 23572^T (pPF72-1, pPF72-2), Pandoraea oxalativorans DSM 23570^T (pPO70-1, pPO70-2, pPO70-3, pPO70-4), Pandoraea vervacti NS15 (pPV15) and Pandoraea apista DSM 16535^T (pPA35) were studied for the first time in this study. The information on plasmid sequences in Pandoraea spp. is useful as the sequences did not match any known plasmid sequence deposited in public databases. Replication genes were not identified in some plasmids, a situation that has led to the possibility of host interaction involvement. Some plasmids were also void of par genes and intriguingly, repA gene was also not discovered in these plasmids. This further leads to the hypothesis of host-plasmid interaction. Plasmid stabilization/stability protein-encoding genes were observed in some plasmids but were not established for participating in plasmid segregation. Toxin-antitoxin systems MazEF, VapBC, RelBE, YgiT-MqsR, HigBA, and ParDE were identified across the plasmids and their presence would improve plasmid maintenance. Conjugation genes were identified portraying the conjugation ability amongst Pandoraea plasmids. Additionally, we found a shared region amongst some of the plasmids that consists of conjugation genes. The identification of genes involved in replication, segregation, toxin-antitoxin systems and conjugation, would aid the design of drugs to prevent the survival or transmission of plasmids carrying pathogenic properties. Additionally, genes conferring virulence and antibiotic resistance were identified amongst the plasmids. The observed features in the plasmids shed light on the Pandoraea spp. as opportunistic pathogens.

Classification of a Hypervirulent Aeromonas hydrophila Pathotype Responsible for Epidemic Outbreaks in Warm-Water Fishes

Lineages of hypervirulent Aeromonas hydrophila (vAh) are the cause of persistent outbreaks of motile Aeromonas septicemia in warm-water fishes worldwide. Over the last decade, this virulent lineage of A. hydrophila has resulted in annual losses of millions of tons of farmed carp and catfish in the People's Republic of China and the United States (US). Multiple lines of evidence indicate US catfish and Asian carp isolates of A. hydrophila affiliated with sequence type 251 (ST251) share a recent common ancestor. To address the genomic context for the putative intercontinental transfer and subsequent geographic spread of this pathogen, we conducted a core genome phylogenetic analysis on 61 Aeromonas spp. genomes, of which 40 were affiliated with A. hydrophila, with 26 identified as epidemic strains. Phylogenetic analyses indicate all ST251 strains form a coherent lineage affiliated with A. hydrophila. Within this lineage, conserved genetic loci unique to A. hydrophila were identified, with some genes present in consistently higher copy numbers than in non-epidemic A. hydrophila isolates. In addition, results from analyses of representative ST251 isolates support the conclusion that multiple lineages are present within US vAh isolated from Mississippi, whereas vAh isolated from Alabama appear clonal. This is the first report of genomic heterogeneity within US vAh isolates, with some Mississippi isolates showing closer affiliation with the Asian grass carp isolate ZC1 than other vAh isolated in the US. To evaluate the biological significance of the identified heterogeneity, comparative disease challenges were conducted with representatives of different vAh genotypes. These studies revealed that isolate ZC1 yielded significantly lower mortality in channel catfish, relative to Alabama and Mississippi vAh isolates. Like other Asian vAh isolates, the ZC1 lineage contains all core genes for a complete type VI secretion system (T6SS). In contrast, more virulent US isolates retain only remnants of the T6SS (clpB, hcp, vgrG, and vasH) which may have functional implications. Collectively, these results characterize a hypervirulent A. hydrophila pathotype that affects farmed fish on multiple continents.

The algicidal activity of Aeromonas sp. strain GLY-2107 against bloom-forming Microcystis aeruginosa is regulated by N-acyl homoserine lactone-mediated quorum sensing

Cyanobacterial blooms have disrupted the efficient utilization of freshwater worldwide. A new freshwater bacterial strain with strong algicidal activity, GLY-2107, was isolated from Lake Taihu and identified as Aeromonas sp. It produced two algicidal compounds: 2107-A (3-benzyl-piperazine-2,5-dione) and 2107-B (3-methylindole). Both compounds exhibited potent algicidal activities against Microcystis aeruginosa, the dominant bloom-forming cyanobacterium in Lake Taihu. The EC₅₀ values (concentration for 50% maximal effect) of 3-benzyl-piperazine-2,5-dione and 3-methylindole were 4.72 and 1.10 μg ml^-1 respectively. Based on a thin-layer chromatography biosensor assay and ultra-performance liquid chromatography-coupled high resolution-tandem mass spectrometry (UPLC-HRMS/MS), the N-acyl homoserine lactone (AHL) profile of strain GLY-2107 was identified as two short side-chain AHLs: N-butyryl-homoserine lactone (C4-HSL) and N-hexanoyl-homoserine lactone (C6-HSL). The production of the two algicidal compounds was controlled by AHL-mediated quorum sensing (QS), and C4-HSL was the key QS signal for the algicidal activity of the strain GLY-2107. Moreover, 3-methylindole was found to be positively regulated by C4-HSL-mediated QS, whereas 3-benzyl-piperazine-2,5-dione might be negatively controlled by C4-HSL-mediated QS. This study suggests that a QS-regulated algicidal system may have potential use for the development of a novel control strategy for harmful cyanobacterial blooms.

Chania multitudinisentens gen. nov., sp. nov., an N-acyl-homoserine-lactone-producing bacterium in the family Enterobacteriaceae isolated from landfill site soil

Phylogenetic and taxonomic characterization was performed for bacterium RB-25T, which was isolated from a soil sample collected in a former municipal landfill site in Puchong, Malaysia. Growth occurred at 20-37 °C at pH 5-8 but not in the presence of 9 % (w/v) NaCl or higher. The principal fatty acids were C16:0, C18:1ω7c and summed feature 3 (C16:1ω7c and/or iso-C15:0 2-OH). Ubiquinone-8 was the only isoprenoid quinone detected. Polar lipid analysis revealed the presence of phospholipid, phosphoaminolipid, phosphatidylethanolamine, phosphatidylglycerol and one unidentified aminolipid. DNA G+C content was 50.9 mol% phylogenetic analysis based on 16S rRNA gene sequence showed that strain RB-25T formed a distinct lineage within the family Enterobacteriaceae of the class Gammaproteobacteria. It exhibited a low level of 16S rRNA gene sequence similarity with its phylogenetic neighbours Pantoea rwandensis LMG 26275T (96.6 %), Rahnella aquatilis CIP 78.65T (96.5 %), Pectobacterium betavasculorum ATCC 43762T (96.4 %), Pantoea rodasii LMG 26273T (96.3 %), Gibbsiella dentisursi NUM 1720T (96.3 %) and Serratia glossinae C1T (96.2 %). Multilocus sequence analyses based on fusA, pyrG, rplB, rpoB and sucA sequences showed a clear distinction of strain RB-25T from the most closely related genera. Isolate RB-25T could also be distinguished from members of these genera by a combination of the DNA G+C content, respiratory quinone system, fatty acid profile, polar lipid composition and other phenotypic features. Strain RB-25T represents a novel species of a new genus, for which the name Chaniamultitudinisentens gen. nov., sp. nov. is proposed. The type strain is RB-25T (=DSM 28811T=LMG 28304T).

Complete genome sequencing of Pandoraea pnomenusa RB38 and Molecular Characterization of Its N-acyl homoserine lactone synthase gene ppnI

In this study, we sequenced the genome of Pandoraea pnomenusa RB38 using Pacific Biosciences RSII (PacBio) Single Molecule Real Time (SMRT) sequencing technology. A pair of cognate luxI/R homologs was identified where the luxI homolog, ppnI, was found adjacent to a luxR homolog, ppnR1. An additional orphan luxR homolog, ppnR2, was also discovered. Multiple sequence alignment and phylogenetic analysis revealed that ppnI is an N-acyl homoserine lactone (AHL) synthase gene that is distinct from those of the nearest phylogenetic neighbor viz. Burkholderia spp. High resolution tandem mass spectrometry (LC-MS/MS) analysis showed that Escherichia coli BL21 harboring ppnI produced a similar AHL profile (N-octanoylhomoserine lactone, C8-HSL) as P. pnomenusa RB38, the wild-type donor strain, confirming that PpnI directed the synthesis of AHL in P. pnomenusa RB38. To our knowledge, this is the first documentation of the luxI/R homologs of the genus Pandoraea.

Isolation of Jeotgalibacillus malaysiensis sp. nov. from a sandy beach, and emended description of the genus Jeotgalibacillus

A Gram-stain-positive, endospore-forming, rod-shaped bacterial strain, designated D5T, was isolated from seawater collected from a sandy beach in a southern state of Malaysia and subjected to a polyphasic taxonomic study. Sequence analysis of the 16S rRNA gene demonstrated that this isolate belongs to the genus Jeotgalibacillus, with 99.87 % similarity to Jeotgalibacillus alimentarius JCM 10872T. DNA–DNA hybridization of strain D5T with J. alimentarius JCM 10872T demonstrated 26.3 % relatedness. The peptidoglycan type was A1α linked directly to l-lysine as the diamino acid. The predominant quinones identified in strain D5T were menaquinones MK-7 and MK-8.The major fatty acids were iso-C15:0 and anteiso-C15:0. The G+C content of its DNA was 43.0 mol%. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and sulfoquinovosyl diacylglycerol, as well as two unknown phospholipids and three unknown lipids. The phenotypic, chemotaxonomic and genotypic data indicated that strain D5T represents a novel species of the genus Jeotgalibacillus, for which the name Jeotgalibacillus malaysiensis sp. nov. is proposed (type strain D5T = DSM 28777T = KCTC33550T). An emended description of the genus Jeotgalibacillus is also provided.

Genome Anatomy of Streptococcus parasanguinis Strain C1A, Isolated from a Patient with Acute Exacerbation of Chronic Obstructive Pulmonary Disease, Reveals Unusual Genomic Features

Streptococcus parasanguinis causes invasive diseases. However, the mechanism by which it causes disease remains unclear. Here, we describe the complete genome sequence of S. parasanguinis C1A, isolated from a patient diagnosed with an acute exacerbation of chronic obstructive pulmonary disease. Several genes that might be associated with pathogenesis are also described.

Draft Genome Sequence of Aeromonas caviae Strain L12, a Quorum-Sensing Strain Isolated from a Freshwater Lake in Malaysia

Here, we present the draft genome sequence of Aeromonas caviae strain L12, which shows quorum-sensing activity. The availability of this genome sequence is important to the research of the quorum-sensing regulatory system in this isolate.

Whole-Genome Analysis of Aeromonas hydrophila Strain 187, Exhibiting Quorum-Sensing Activity

Aeromonas hydrophila is a quorum-sensing (QS) bacterium that causes diarrhea in humans upon infection. Here, we report the genome of pathogenic Aeromonas hydrophila strain 187, which possesses a QS gene responsible for signaling molecule N-acyl homoserine lactone (AHL) synthesis and has been found to be located at contig 36.