Genome Sequence of Hybrid Vibrio cholerae O1 MJ-1236, B-33, and CIRS101 and Comparative Genomics with V. cholerae

The genomes of Vibrio cholerae O1 Matlab variant MJ-1236, Mozambique O1 El Tor variant B33, and altered O1 El Tor CIRS101 were sequenced. All three strains were found to belong to the phylocore group 1 clade of V. cholerae, which includes the 7th-pandemic O1 El Tor and serogroup O139 isolates, despite displaying certain characteristics of the classical biotype. All three strains were found to harbor a hybrid variant of CTXΦ and an integrative conjugative element (ICE), leading to their establishment as successful clinical clones and the displacement of prototypical O1 El Tor. The absence of strain- and group-specific genomic islands, some of which appear to be prophages and phage-like elements, seems to be the most likely factor in the recent establishment of dominance of V. cholerae CIRS101 over the other two hybrid strains.Vibrio cholerae, a bacterium autochthonous to the aquatic environment, is the causative agent of cholera, a life-threatening disease that causes severe, watery diarrhea. Cholera bacteria are serogrouped based on their somatic O antigens, with more than 200 serogroups identified to date (6). Only toxigenic strains of serogroups O1 and O139 have been identified as agents of cholera epidemics and pandemics; serogroups other than O1 and O139 have the potential to cause mild gastroenteritis or, rarely, local outbreaks. Genes coding for cholera toxin (CTX), ctxAB, and other virulence factors have been shown to reside in bacteriophages and various mobile genetic elements. In addition, V. cholerae serogroup O1 is differentiated into two biotypes, classical and El Tor, by a combination of biochemical traits, by sensitivity to biotype-specific bacteriophages, and more recently by nucleotide sequencing of specific genes and by molecular typing (5, 17, 19).There have been seven pandemics of cholera recorded throughout human history. The seventh and current pandemic began in 1961 in the Indonesian island of Sulawesi and subsequently spread to Asia, Africa, and Latin America; the six previous pandemics are believed to have originated in the Indian subcontinent. Isolates of the sixth pandemic were almost exclusively of the O1 classical biotype, whereas the current (seventh) pandemic is dominated by the V. cholerae O1 El Tor biotype as the causative agent, a transition occurring between 1923 and 1961. Today, the disease continues to remain a scourge in developing countries, confounded by the fact that V. cholerae is native to estuaries and river systems throughout the world (8).Over the past 20 years, several new epidemic lineages of V. cholerae O1 El Tor have emerged (or reemerged). For example, in 1992, a new serogroup, namely, O139 of V. cholerae, was identified as the cause of epidemic cholera in India and Bangladesh (25). The initial concern was that a new pandemic was beginning; however, the geographic range of V. cholerae O139 is currently restricted to Asia. Additionally, V. cholerae O1 hybrids and altered El Tor variants have been isolated repeatedly in Bangladesh (Matlab) (23, 24) and Mozambique (1). Altered V. cholerae O1 El Tor isolates produce cholera toxin of the classical biotype but can be biotyped as El Tor by conventional phenotypic assays, whereas V. cholerae O1 hybrid variants cannot be biotyped based on phenotypic tests and can produce cholera toxin of either biotype. These new variants have subsequently replaced the prototype seventh-pandemic V. cholerae O1 El Tor strains in Asia and Africa, with respect to frequency of isolation from clinical cases of cholera (27).Here, we report the genome sequence of three V. cholerae O1 variants, MJ-1236, a Matlab type I hybrid variant from Bangladesh that cannot be biotyped by conventional methods, CIRS101, an altered O1 El Tor isolate from Bangladesh which harbors ctxB of classical origin, and B33, an altered O1 El Tor isolate from Mozambique which harbors classical CTXΦ, and we compare their genomes with prototype El Tor and classical genomes. From an epidemiological viewpoint, among the three variants characterized in this study, V. cholerae CIRS101 is currently the most “successful” in that strains belonging to this type have virtually replaced the prototype El Tor in Asia and many parts of Africa, notably East Africa. This study, therefore, gives us a unique opportunity to understand why V. cholerae CIRS101 is currently the most successful El Tor variant.     

Synthesis of methyl esters from palm (Elaeis guineensis) oil using cobalt doped MgO as solid oxide catalyst

The potential of Mg(x)Co(2-)(x)O(2) as heterogeneous reusable catalyst in transesterification of palm oil to methyl ester was investigated. The catalyst was prepared via co-precipitation of the metal hydroxides at different Mg-Co ratios. Mg(1.7)Co(0.3)O(2) catalyst was more active than Mg(0.3)Co(1.7)O(2) in the transesterification of palm oil with methanol. The catalysts calcined at temperature 300 °C for 4 h resulted in highly active oxides and the highest transesterification of 90% was achieved at methanol/oil molar ratio of 9:1, catalyst loading of 5.00 wt.%, reaction temperature of 150 °C and reaction time of 2 h. The catalyst could easily be removed from reaction mixture, but showed 50% decrease in activity when reused due to leaching of active sites.     

Preliminary findings of age and male sexual characteristics andand potential effect to semen characteristics and cryopreservation of the critically endangered Bornean orangutan in Malaysia

Primates - Bornean orangutan is a critically endangered non-human primate; however, the threat of extinction is not merely from poaching and habitat loss. Orangutan survival is also threatened by...     

Depletion of preexisting B-cell lymphoma 2-expressing senescent cells before vaccination impacts antigen-specific antitumor immune responses in old mice

The age-related decline in immunity reduces the effectiveness of vaccines in older adults. Immunosenescence is associated with chronic, low-grade inflammation, and the accumulation of senescent cells. The latter express Bcl-2 family members (providing resistance to cell death) and exhibit a pro-inflammatory, senescence-associated secretory phenotype (SASP). Preexisting senescent cells cause many aging-related disorders and therapeutic means of eliminating these cells have recently gained attention. The potential consequences of senescent cell removal on vaccine efficacy in older individuals are still ignored. We used the Bcl-2 family inhibitor ABT-263 to investigate the effects of pre-vaccination senolysis on immune responses in old mice. Two different ovalbumin (OVA)-containing vaccines (containing a saponin-based or a CpG oligodeoxynucleotide adjuvant) were tested. ABT-263 depleted senescent cells (apoptosis) and ablated the basal and lipopolysaccharide-induced production of SASP-related factors in old mice. Depletion of senescent cells prior to vaccination (prime/boost) had little effect on OVA-specific antibody and T-cell responses (slightly reduced and augmented, respectively). We then used a preclinical melanoma model to test the antitumor potential of senolysis before vaccination (prime with the vaccine and OVA boost by tumor cells). Surprisingly, ABT-263 treatment abrogated the vaccine's ability to protect against B16 melanoma growth in old animals, an effect associated with reduced antigen-specific T-cell responses. Some, but not all, of the effects were age-specific, which suggests that preexisting senescent cells were partly involved. Hence, depletion of senescent cells modifies immune responses to vaccines in some settings and caution should be taken when incorporating senolytics into vaccine-based cancer therapies.     

Short, interspersed, and repetitive DNA sequences in Spiroplasma species

Small fragments of DNA from an 8-kbp plasmid, pRA1, from a plant pathogenic strain of Spiroplasma citri were shown previously to be present in the chromosomal DNA of at least two species of Spiroplasma. We describe here the shot-gun cloning of chromosomal DNA from S. citri Maroc and the identification of two distinct sequences exhibiting homology to pRA1. Further subcloning experiments provided specific molecular probes for the identification of these two sequences in chromosomal DNA from three distinct plant pathogenic species of Spiroplasma. The results of Southern blot hybridization indicated that each of the pRA1-associated sequences is present as multiple copies in short, dispersed, and repetitive sequences in the chromosomes of these three strains. None of the sequences was detectable in chromosomal DNA from an additional nine Spiroplasma strains examined.     

Screening of antimicrobial,antioxidant, antidiabetic activities,anatomical and morphological properties of Colchicum speciosum Steven (Colchicaceae)

Protoplasma - Colchicum speciosum Steven species is a perennial stemless plant. C. speciosum is a flowering herb native to mountainous regions of northern Turkey, the Caucasus, and northern Iran....     

Comparison of bioethanol production from cultivated versus wild <Emphasis Type="Italic">Gracilaria verrucosa</Emphasis> and <Emphasis Type="Italic">Gracilaria gigas</Emphasis>

The seaweed genus Gracilaria is a potential candidate for the production of bioethanol due to its high carbohydrate content. Gracilaria is abundant throughout the world and can be found in both wild and cultivated forms. Differences in the ecological factors such as temperature, salinity, and light intensity affecting wild and cultivated specimens may influence the biochemical content of seaweeds, including the carbohydrate content. This study aimed to investigate the proximate composition and potential bioethanol production of wild and cultivated G. gigas and G. verrucosa. Bioethanol was produced using separate hydrolysis fermentation (SHF), employing a combination of enzymatic and acid hydrolysis, followed by fermentation with Saccharomyces cerevisiae ATCC 200062. The highest carbohydrate content was found in wild G. gigas. The highest galactose and glucose contents (20.21 ± 0.32 and 9.70 ± 0.49 g L^?1, respectively), as well as the highest production of bioethanol (3.56 ± 0.02 g L^?1), were also found in wild G. gigas. Thus, we conclude that wild G. gigas is the most promising candidate for bioethanol production. Further research is needed to optimize bioethanol production from wild G. gigas. Domestication of wild G. gigas is a promising challenge for aquaculture to avoid overexploitation of this wild seaweed resource.