Mozammel Hoq

Comparative genomics of clinical and environmental Vibrio mimicus

Whether Vibrio mimicus is a variant of Vibrio cholerae or a separate species has been the subject of taxonomic controversy. A genomic analysis was undertaken to resolve the issue. The genomes of V. mimicus MB451, a clinical isolate, and VM223, an environmental isolate, comprise ca. 4,347,971 and 4,313,453 bp and encode 3,802 and 3,290 ORFs, respectively. As in other vibrios, chromosome I (C-I) predominantly contains genes necessary for growth and viability, whereas chromosome II (C-II) bears genes for adaptation to environmental change. C-I harbors many virulence genes, including some not previously reported in V. mimicus, such as mannose-sensitive hemagglutinin (MSHA), and enterotoxigenic hemolysin (HlyA); C-II encodes a variant of Vibrio pathogenicity island 2 (VPI-2), and Vibrio seventh pandemic island II (VSP-II) cluster of genes. Extensive genomic rearrangement in C-II indicates it is a hot spot for evolution and genesis of speciation for the genus Vibrio. The number of virulence regions discovered in this study (VSP-II, MSHA, HlyA, type IV pilin, PilE, and integron integrase, IntI4) with no notable difference in potential virulence genes between clinical and environmental strains suggests these genes also may play a role in the environment and that pathogenic strains may arise in the environment. Significant genome synteny with prototypic pre-seventh pandemic strains of V. cholerae was observed, and the results of phylogenetic analysis support the hypothesis that, in the course of evolution, V. mimicus and V. cholerae diverged from a common ancestor with a prototypic sixth pandemic genomic backbone.

Deep-sea hydrothermal vent bacteria related to human pathogenic Vibrio species

Significance During Alvin and Nautile dives in 1999, samples were collected from water surrounding sulfide chimneys of a hydrothermal vent along the East Pacific Rise and four mesophilic bacteria were isolated, including a novel Vibrio species, Vibrio antiquarius. Genomic, functional, and phylogenetic analyses indicate an intriguing blend of genomic features related to adaptation and animal symbiotic association, and also revealed the presence of virulence genes commonly found in Vibrio species pathogenic for humans. The presence of these virulence genes in an ecologically distinct Vibrio species was surprising. It is concluded that pathogenicity genes serve a far more fundamental ecological role than solely causation of human disease. Vibrio species are both ubiquitous and abundant in marine coastal waters, estuaries, ocean sediment, and aquaculture settings worldwide. We report here the isolation, characterization, and genome sequence of a novel Vibrio species, Vibrio antiquarius, isolated from a mesophilic bacterial community associated with hydrothermal vents located along the East Pacific Rise, near the southwest coast of Mexico. Genomic and phenotypic analysis revealed V. antiquarius is closely related to pathogenic Vibrio species, namely Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio harveyi, and Vibrio vulnificus, but sufficiently divergent to warrant a separate species status. The V. antiquarius genome encodes genes and operons with ecological functions relevant to the environment conditions of the deep sea and also harbors factors known to be involved in human disease caused by freshwater, coastal, and brackish water vibrios. The presence of virulence factors in this deep-sea Vibrio species suggests a far more fundamental role of these factors for their bacterial host. Comparative genomics revealed a variety of genomic events that may have provided an important driving force in V. antiquarius evolution, facilitating response to environmental conditions of the deep sea.

Thrombolytic Activity of Alkaline Protease Purified from a Mutant Strain Bacillus licheniformis MZK05M9

Investigations were performed to find out new microbial enzymes as thrombolytics having better efficacy and specificity. Mutant strain of Bacillus species, B. licheniformis MZK05M9 was cultured in modified urea-glucose media followed by purification using ammonium sulphate precipitation and ultrafiltration through centricon tube of specific MWCO value. The production method yielded 823.42 units/mg of the crude enzyme from mutant strain MZK05M9 and after purification 37695.64 units/mg. The molecular weight of the purified enzyme was estimated as 27.2 kDa and purification increased its specific activity to 16.5 fold with a recovery of 10%. The purified proteases were identified as serine proteases by irreversible inhibition of activity with phenylmethylsulfonyl fluoride (PMSF) and it exhibited 32.84% thrombolytic activity, by in vitro clot lysis assay. Stability studies showed that crude enzyme from mutant strain MZK05M9 remained stable up to a temperature of 45 ̊C and showed maximum stability at pH range 7.5 to 8.5. Our observation indicates that proteases produced by Bacillus licheniformis mutant have the potential to be developed as a viable thrombolytic agent.

Partial Purification of Protease from Bacillus licheniformis and its Application as Thrombolytic Agent.

A belongs to a group of fungal toxins known as mycotoxins, and is widespread in agricultural products and food. Aflatoxin is associated with both acute and chronic toxicity in animals and humans including acute liver damage, liver cirrhosis and liver cancer. Aflatoxins are predominantly produced by Aspergillus flavus and Aspergillus parasiticus but may also be produced by other strains, such as Aspergillus nomius, Aspergillus tamari and Aspergillus pseudotamarii. Aflatoxin M1 (AFM1) is a highly toxic compound found in milk. Aflatoxin M1 is considered as a ‘milk toxin’. Presence of aflatoxin M1 in milk is a public health hazard. Growing children are more sensitive than adults as milk is one of their main sources of nutrients. The aim of this study is to determine the ability of specific lactic acid bacteria strains to remove aflatoxin M1 from liquid media. Six dairy strains of lactic acid bacteria were tested for their ability to remove aflatoxin M1 from liquid medium. Both viable and dead bacteria from the same population were tested. Two lactic acid bacterial strains which exhibited the best AFM1 removal abilities were also tested using contaminated skimmed and full cream milk. Both skimmed milk and full cream milk were used with both viable and heat-killed bacteria assessed. All strains, both viable and heat-killed, could reduce the AFM1 content of a liquid medium. From the results we can conclude that specific dairy strains of lactic acid bacteria can offer means of decontaminating aflatoxin M1 from milk.A high yield of levan production (22 g/L at 24 h; 22 g/L/d; 33.3 % by sucrose consumption) was obtained when the bacteria were cultured in medium containing sugarcane juice (containing 78 g/L of sucrose ) at pH 6.5, temperature 37 °C and agitation speed 175 rpm. The fermentation broth was concentrated by ultrafiltration through a membrane of 5 kDa cutoff. The concentrate was harvested of levan by precipitation by addition of 4 vols. cold ethanol; the filtrate containing glucose was proven to be a suitable medium for ε-PL production by Streptomyces albulus when it was supplemented with yeast extract, (NH4)2SO4 and basal salts. 4.4 g/L of ε-PL accumulation was obtained in 72 h using two-stage fermentation with control of pH.Quorum sensing (QS) is a process which included communication between bacterial cells. There are three types of QS system, LuxI/LuxR– type Quorum sensing in gram negative bacteria,oligopeptide–two componenttype quorum sensing in gram positive bacteria and LuxS encoded autoinducer 2 (AI-2) quorum sensing in both gram positive and negative. Formation of biofilm is controlled by QS system such as, formation of biofilm in P.aeruginosa is coordinated by QS pathway.Crimean- Congo Hemorrhagic Fever (CCHF) is a viral zoonotic tick-born disease with a mortality rate of up to 50% in humans. After a short incubation period, the disease is characterized by sudden fever, chills, severe headache, dizziness, back, and abdominal pain. Additional symptoms can include nausea, vomiting, diarrhea, neuropsychiatric, and cardiovascular changes. In severe cases, hemorrhagic manifestations, ranging from petechiae to large areas of ecchymosis develop. The CCHF Virus (CCHFV) is from the genus Nairovirus and family Bunyaviridae. CCHFV is transmitted to humans by the bite of infected tick and by direct contact with blood or tissue from infected humans and livestock. In addition to zoonotic transmission, CCHFV can be spread from person to person and is one of the rare hemorrhagic fever viruses able to cause nosocomial outbreaks in hospitals. CCHF is a public health problem in many regions of the world e.g Eastern Europe, Asia, Middle East, and Africa. The history of CCHF in Iran shows that the disease has been detected in Iran since 1970. From 1970 to 1978 some scientists worked on serology and epidemiology of this disease in humans and livestock in Iran. Since 1999 , establishment of a surveillance and laboratory detection system on viral hemorrhagic fevers particularly on CCHF has had benefits. One of which is the fact that a mortality rate approaching 20% in the year 2000 remarkably dropped to 6% in the year 2007.The genus Fusarium contains a number of soil-borne species with worldwide distribution. The presented PCR assays are highly selective and sensitive in detecting the Fusarium genus. In order to identify the eighteen Fusarium isolates obtained at the molecular level. PCR analysis using primer specific for the conserved ITS DNA region of Fusarium genus was conducted. The data indicated that all of the eighteen isolates showed a clear band corresponding to the expected molecular size of the ITS region (431bp). These results confirmed that all the tested samples belong to the genus Fusarium. Also, when all eighteen isolates of Fusarium species were analyzed by PCR for fumonisin producing ability using FUM1 gene-based primers, the expected DNA fragment of 183 bp was amplified only in Fusarium verticillioides (3 isolates), Fusarium avenaceum (3 isolates), Fusarium semitectum (1 isolate) and Fusarium culmorum (2 isolates) showed a positive result with FUM1 gene set of primers. No bands were seen in other isolates of Fusarium spp. and the standard (Fusarium graminearum). In case of zearalenone, the PKS4 gene of F. graminearum has been reported to be essential for the production of zearalenone. The result indicated that the expected DNA fragment of 280 bp was amplified only in Fusarium verticillioides (3 isolates), Fusarium avenaceum (3 isolates) and Fusarium culmorum (2 isolates) and Fusarium graminearum. Microsatellite-primed PCR resembles the well-known RAPD technique but is advantageous because of the ability to generate more complex banding patterns and a high degree of reproducibility. The discriminating powers of the three MP-primers [(CTG)5, (M13) and (T3B)] used in this study were nearly the same. Cluster analyses were performed on the genomic fingerprints generated by each of the primers tested. Three dendrograms were generated with the UPGMA method. The patterns resulting from the T3B and (CTG)5 test were more distinct and T3B was the most successful primer because it always led to high polymorphic banding patterns that were suitable for interspecies comparisons. Our results indicated that there was no association between clustering in the MP-PCR dendrogram and the geographic origin and morphological identification of the tested isolates. Ekram A. M. Al-Sanae, Afaf I. Shehata, Ali H. Bahkali, , Mohammed Abdo Yahya and Amal A. Al