Phage cocktail to control the exponential growth of normal flora in processed sputum specimens grown overnight in liquid medium for rapid TB diagnosis

The mechanical pressure exerted during centrifugation and the chemical pressure experienced when sputum specimens are processed, leave the tubercle bacilli in the sputum unsuitable for rapid detection especially in phage based assays. Thus, growing Mycobacterium tuberculosis in broth, at least overnight, is mandatory for allowing the tubercle bacilli to recoup. During this time the surviving colonizing flora grow faster and overgrow tubercle bacilli interfering with TB diagnosis. In the present study normal flora surviving the action of 4% NaOH was isolated and characterized. Phages capable of killing 14 different species representing this normal flora were isolated from soil and sewage samples and characterized. A novel and bio-friendly approach to treat sputum samples with a cocktail of three phages capable of killing most of the 14 representative organisms and not infecting mycobacteria is explored to control the overgrowth of colonizing bacteria in broth culture. While 26 of the 100 sputum samples processed by modified Petroff's procedure showed growth of colonizing flora on blood agar, all of them when grown in broth overnight showed mixed, confluent growth. The addition of phagebiotics controlled them all, showing a significant reduction in colony forming units but resulting in few discrete colonies in 54 samples. Isolation of phages capable of controlling these surviving organisms and including them in the phagebiotics mixture should lead to the control of colonizing bacteria effectively.     

Antimicrobial activity of metal based nanoparticles against microbes associated with diseases in aquaculture

The emergence of diseases and mortalities in aquaculture and development of antibiotics resistance in aquatic microbes, has renewed a great interest towards alternative methods of prevention and control of diseases. Nanoparticles have enormous potential in controlling human and animal pathogens and have scope of application in aquaculture. The present investigation was carried out to find out suitable nanoparticles having antimicrobial effect against aquatic microbes. Different commercial as well as laboratory synthesized metal and metal oxide nanoparticles were screened for their antimicrobial activities against a wide range of bacterial and fungal agents including certain freshwater cyanobacteria. Among different nanoparticles, synthesized copper oxide (CuO), zinc oxide (ZnO), silver (Ag) and silver doped titanium dioxide (Ag–TiO₂) showed broad spectrum antibacterial activity. On the contrary, nanoparticles like Zn and ZnO showed antifungal activity against fungi like Penicillium and Mucor species. Since CuO, ZnO and Ag nanoparticles showed higher antimicrobial activity, they may be explored for aquaculture use.     

Carcass traits of two marketable size classes of Pangasius pangasius (Hamilton, 1822)

Carcass and commercial yield traits of Pangasius pangasius were evaluated and morphometric parameters measured along with carcass traits in two marketable weight classes (average ± SD) 1603 ± 49.5 g and 1985.6 ± 56.6 g. The Pangas fish head yield was 14.80% and 15.1% for the 2000 g and 1600 g weight classes, respectively. The offal percentage varied from 8.6 to 8.8 in both weight classes. Pangasius had a significant accumulation of fat deposits in mesenteric tissue and on the lining of the abdominal cavity. Headless (73.2%), head and skinless (68.7%), head, skin and boneless (57.7%) dressing yields were significantly higher in 1600 g than in the 2000 g weight class. The 2000 g weight class category exhibited mesenteric fat (4.3%), dissected subcutaneous and intramuscular fat (10.1%) which was significantly higher than in the 1600 g weight class. The yields of dressing stages were affected mostly by skin (8.3–4.5%) and mesenteric fat (4.3–3.7%), and dissected subcutaneous and intramuscular fat (10.1–6.8%), which is significantly higher in the 2000 g than in the 1600 g category. The later weight class category resulted in more meat yield, and less bone, skin and fat yields.     

Identification and genetic characterization of a gibberellin 2-oxidase gene that controls tree stature and reproductive growth in plum

Several dwarf plum genotypes (Prunus salicina L.), due to deficiency of unknown gibberellin (GA) signalling, were identified. A cDNA encoding GA 2-oxidase (PslGA2ox), the major gibberellin catabolic enzyme in plants, was cloned and used to screen the GA-deficient hybrids. This resulted in the identification of a dwarf plum hybrid, designated as DGO24, that exhibits a markedly elevated PslGA2ox signal. Grafting 'Early Golden' (EG), a commercial plum cultivar, on DGO24 (EG/D) enhanced PslGA2ox accumulation in the scion part and generated trees of compact stature. Assessment of active GAs in such trees revealed that DGO24 and EG/D accumulated relatively much lower quantities of main bioactive GAs (GA(1) and GA(4)) than control trees (EG/M). Moreover, the physiological function of PslGA2ox was studied by determining the molecular and developmental consequences due to ectopic expression in Arabidopsis. Among several lines, two groups of homozygous transgenics that exhibited contrasting phenotypes were identified. Group-1 displayed a dwarf growth pattern typical of mutants with a GA deficiency including smaller leaves, shorter stems, and delay in the development of reproductive events. In contrast, Group-2 exhibited a 'GA overdose' phenotype as all the plants showed elongated growth, a typical response to GA application, even under limited GA conditions, potentially due to co-suppression of closely related Arabidopsis homologous. The studies reveal the possibility of utilizing PslGA2ox as a marker for developing size-controlling rootstocks in Prunus.     

Characterization and expression of the putative ovarian lipoprotein receptor in the Kuruma prawn, Marsupenaeus japonicus

Ovarian low density lipoproteins (LDL) such as vitellogenin (Vg) are the precursors of the major yolk protein vitellin, and constitute the major source of nutrients serving the developing embryo. The objective of this study was to gain a better understanding of crustacean egg development by focusing on the process of Vg internalization by its receptor (ovarian LDLR). First, an ovarian LDLR cDNA sequence in Marsupenaeus japonicus was determined. Ovarian LDLR mRNA expression was then examined, and was seen to be specific to the ovary, exhibiting highest levels during the previtellogenic stage. This pattern of ovarian LDLR expression is thought to signify preparation for yolk protein incorporation into the oocyte. Using immunoblotting techniques, an ovarian LDLR band was detected whose size was similar to that estimated from the deduced amino acid sequence. The ovarian LDLR protein was expressed only at the onset of vitellogenesis, and histological studies supported these observations. This is the first occasion that the ovarian LDLR and its expression dynamics during vitellogenesis have been fully characterized in a crustacean.     

Origins of highly mosaic mycobacteriophage genomes

Bacteriophages are the most abundant organisms in the biosphere and play major roles in the ecological balance of microbial life. The genomic sequences of ten newly isolated mycobacteriophages suggest that the bacteriophage population as a whole is amazingly diverse and may represent the largest unexplored reservoir of sequence information in the biosphere. Genomic comparison of these mycobacteriophages contributes to our understanding of the mechanisms of viral evolution and provides compelling evidence for the role of illegitimate recombination in horizontal genetic exchange. The promiscuity of these recombination events results in the inclusion of many unexpected genes including those implicated in mycobacterial latency, the cellular and immune responses to mycobacterial infections, and autoimmune diseases such as human lupus. While the role of phages as vehicles of toxin genes is well established, these observations suggest a much broader involvement of phages in bacterial virulence and the host response to bacterial infections.