Genera Of Pathogenic Bacteria Research Articles

Functional and mechanistic studies of a phytogenic formulation, Shrimp Best, in growth performance and vibriosis in whiteleg shrimp

Climate change and disease threaten shrimp farming. Here, we studied the beneficial properties of a phytogenic formulation, Shrimp Best (SB), in whiteleg shrimp. Functional studies showed that SB dose-dependently increased shrimp body weight and decreased feed conversion ratio. We found that SB protected against Vibrio parahaemolyticus as evidenced by survival rate, bacterial load, and hepatopancreatic pathology in shrimp. Finally, we explored the likely mechanism by which SB affects growth performance and vibriosis in shrimp. The 16S rRNA sequencing data showed that SB increased 6 probiotic genera and decreased 6 genera of pathogenic bacteria in shrimp. Among these, SB increased the proportion of Lactobacillus johnsonii and decreased that of V. parahaemolyticus in shrimp guts. To dissect the relationship among SB, Lactobacillus and Vibrio, we investigated the in vitro regulation of Lactobacillus and Vibrio by SB. SB at ≥ 0.25 μg/mL promoted L. johnsonii growth. Additionally, L. johnsonii and its supernatant could inhibit V. parahaemolyticus. Furthermore, SB could up-regulate five anti-Vibrio metabolites of L. johnsonii, which caused bacterial membrane destruction. In parallel, we identified 3 fatty acids as active compounds from SB. Overall, this work demonstrated that SB improved growth performance and vibriosis protection in shrimp via the regulation of gut microbiota.

Pathogens in anurans from a seasonal tropical environment in Guanajuato, Mexico

In the present study, we characterized species of bacteria and fungi across a frog community in a seasonal tropical environment in the Natural Protected Area (NPA) Las Musas, Guanajuato, Mexico, using morphological and biochemical protocols. Our three main objectives were to: i) identify the species of microorganisms present in the frog community, ii) determine microorganism prevalence and how it changes throughout the year, and iii) detect diseases and injuries caused by pathogens (bacteria and fungi). Across 150 anurans analyzed, seven species of anurans especies (Anaxyrus compactilis, Incilius occidentalis, Dryophytes arenicolor, D. eximius, Hypopachus variolosus, Lithobates neovolcanicus y Spea multiplicata) hosted at least four genera of pathogenic fungi (Penicillium, Rhizopus, Aspergillus y Batrachochytrium) and two genera of pathogenic bacteria (Aeromonas hydrophila and Pseudomonas sp.). We found the prevalence of positive cases was higher in autumn (0.51) than in summer (0.125). Lesions such as peeling of the skin on the belly and swelling of the extremities (red leg) were observed in four of the seven species. This study confirms the presence of bacterial and fungal pathogenic agents in this frog community, and serves as a precedent for future work on monitoring the state of amphibian population health in Guanajuato. It also provides support for the implementation of conservation strategies for this group of vertebrates.

Thermal inactivation kinetics of seven genera of vegetative bacterial pathogens common to the food chain are similar after adjusting for effects of water activity, sugar content and pH

A predictive model was made for the logarithm of the thermal decimal reduction time (logD) of Salmonella enterica (D = time to 90% reduction by inactivation). The model was fitted with multiple linear regression from 521 logD-values reported in literature for laboratory media and foods highly varying in water activity and pH. The single regression model with temperature as the only variable had a high residual standard error (RSE) of 0.883 logD and no predictive value (fraction of variance explained (R2) < 0.001). Adding water activity, sugar content and pH as predictors resulted in a model with a lower RSE of 0.458 logD and an adjusted R2 of 0.73. The model was validated by comparing 985 predicted with observed logD for S. enterica from other publications. The model was subsequently validated with 1498 published logD-values for inactivation of vegetative cells of nine other pathogenic bacteria genera (mainly Listeria monocytogenes, Escherichia coli, Clostridium perfringens, Cronobacter spp., Staphylococcus aureus, Yersinia enterocolitica) in or on a variety of laboratory media, meat, fish, dairy, nuts, fruits and vegetables. Regression analyses for validation with the 985 logD of S. enterica and 2483 logD of all genera show deviations from the expected slope of 1 (both 0.81) and the expected intercept of 0 (0.04 and 0.19 logD respectively). However, only 0.7% and 2% respectively of the new logD (expected: 0.5%) were observed above the 99% prediction interval of the original S. enterica model based on 521 logD. The findings suggest that i) the variability of thermal resistance of strains within species is larger than between genera and species; ii) one generic predictive model, also accounting for variability, suffices for designing the thermal inactivation of a variety of vegetative pathogenic bacteria in many food types.

Changes in the gastrointestinal microbial community of Lateolabrax maculatus in a naturally occurring Microcystis aeruginosa bloom environment

Microcystis aeruginosa bloom in aquatic ecosystems is a worldwide problem that threaten aquatic animals. Fish are an unavoidable link between toxic cyanobacteria and human health. A stable microbiota is an important barrier for fish in defence against pathogen invasion. Therefore, in this study, we investigated the microbiota characteristics in different parts of the gastrointestinal tract and faeces of Lateolabrax maculatus that were cultured in a pond with a naturally occurring M. aeruginosa bloom. Compared with those of the healthy fish, the cyanobacterial bloom decreased the serum immune indexes of the diseased fish, such as the immunoglobulin M content and lysozyme activity. Microbiome analysis showed that the M. aeruginosa bloom did not change the microbial richness and diversity of the diseased fish but significantly altered the community composition. Specifically, M. aeruginosa bloom increased the abundance of Proteobacteria but decreased the abundance of Firmicutes; some genera of pathogenic bacteria (Acinetobacter, Mycobacterium and Staphylococcus) were abundant, while some beneficial bacteria (Weissella and Lactococcus) were reduced. Our results reveal that M. aeruginosa bloom significantly impair the immunity and gastrointestinal microbiota composition of L. maculatus and that microbiota variation may be a factor causing almost all fishes exhibit unhealthy or diseased characteristics. These results will be helpful for the utilization of microbiome characteristics to facilitate healthy fish farming in cyanobacterial bloom environments.

An Efficient Inoculation Technique to Assess the Pathogenicity of Pantoea Species Associated to Bacterial Blight of Rice.

Bacteria blight diseases of rice due to several genera of pathogenic bacteria are one of the major constraints worldwide for rice production. The disease can be best managed through host plant resistance sources. For most of these bacteria such as Xanthomonas oryzae pv. oryzae, X. oryzae pv. oryzicola, Pseudomonas fuscovaginae, Burkholderia glumae, Burkholderia gladioli and Acidovorax avenae subsp. avenae, specific diagnostic techniques that include molecular and pathogenicity tests have been developed. However, for Pantoea spp., information on pathogenicity assay is very limited and protocols used are not uniform. Most authors use the leaf clipping method. In this paper, we describe the protocol for mechanical inoculation of rice seedlings aged 35 days. The method consists of infiltrating bacterial suspensions at concentrations of 108 CFU/ml, with a needleless syringe into the intercellular and interveinal spaces of rice leaves underside at about 4-5 cm below the leaf tip. This method can be used for a standardized pathogenicity assessment, germplasm resistance evaluation for identifying and characterizing resistance sources.

Regulation of Chlamydia Gene Expression by Tandem Promoters with Different Temporal Patterns.

Chlamydia is a genus of pathogenic bacteria with an unusual intracellular developmental cycle marked by temporal waves of gene expression. The three main temporal groups of chlamydial genes are proposed to be controlled by separate mechanisms of transcriptional regulation. However, we have noted genes with discrepancies, such as the early gene dnaK and the midcycle genes bioY and pgk, which have promoters controlled by the late transcriptional regulators EUO and σ(28). To resolve this issue, we analyzed the promoters of these three genes in vitro and in Chlamydia trachomatis bacteria grown in cell culture. Transcripts from the σ(28)-dependent promoter of each gene were detected only at late times in the intracellular infection, bolstering the role of σ(28) RNA polymerase in late gene expression. In each case, however, expression prior to late times was due to a second promoter that was transcribed by σ(66) RNA polymerase, which is the major form of chlamydial polymerase. These results demonstrate that chlamydial genes can be transcribed from tandem promoters with different temporal profiles, leading to a composite expression pattern that differs from the expression profile of a single promoter. In addition, tandem promoters allow a gene to be regulated by multiple mechanisms of transcriptional regulation, such as DNA supercoiling or late regulation by EUO and σ(28). We discuss how tandem promoters broaden the repertoire of temporal gene expression patterns in the chlamydial developmental cycle and can be used to fine-tune the expression of specific genes. Chlamydia is a pathogenic bacterium that is responsible for the majority of infectious disease cases reported to the CDC each year. It causes an intracellular infection that is characterized by coordinated expression of chlamydial genes in temporal waves. Chlamydial transcription has been shown to be regulated by DNA supercoiling, alternative forms of RNA polymerase, and transcription factors, but the number of transcription factors found in Chlamydia is far fewer than the number found in most bacteria. This report describes the use of tandem promoters that allow the temporal expression of a gene or operon to be controlled by more than one regulatory mechanism. This combinatorial strategy expands the range of expression patterns that are available to regulate chlamydial genes.

Isolation of some active materials and aqueous, alcoholic and oil seed extracts of the plant (Curcuma longa (and study Antibacterial and anticancer activity

This study included isolation of some active materials from Curcuma longa such as tannins, saponins and volatile oils with percentage of 59%, 31%, and 9% respectively. Also the study included the determination of minerals in Curcuma longa such as " Na, Ca and K" using Flame photometer. The concentrations of these minerals were (14 ppm),(10 ppm) and )76 ppm) respectively. The anti-bacterial activity study was performed for the active materials isolated from Curcuma longa against two genus of pathogenic bacteria, Escherichia Coli and Staphylococcus aurous by using agar-well diffusion method. It appeared from this study that all of the extraction have inhibitory effect on bacteria was used. The inhibition zone diameter varies with the type of active compound, its concentration and the types of bacteria. The results obtained were analyzed statistically way (one way ANOVA) she stated results that alcoholic extract warm has had the greatest influence on the ratio of the number of cells developing and the effect was significantly (P

Isolation of some active materials and aqueous, alcoholic and oil seed extracts of the plant (Curcuma longa (and study Antibacterial and anticancer activity

This study included isolation of some active materials from Curcuma longa such as tannins, saponins and volatile oils with percentage of 59%, 31%, and 9% respectively. Also the study included the determination of minerals in Curcuma longa such as " Na, Ca and K" using Flame photometer. The concentrations of these minerals were (14 ppm),(10 ppm) and )76 ppm) respectively. The anti-bacterial activity study was performed for the active materials isolated from Curcuma longa against two genus of pathogenic bacteria, Escherichia Coli and Staphylococcus aurous by using agar-well diffusion method. It appeared from this study that all of the extraction have inhibitory effect on bacteria was used. The inhibition zone diameter varies with the type of active compound, its concentration and the types of bacteria. The results obtained were analyzed statistically way (one way ANOVA) she stated results that alcoholic extract warm has had the greatest influence on the ratio of the number of cells developing and the effect was significantly (P

ISOLATION OF SOME ACTIVE MATERIALS FROM AQUEOUS, ALCOHOLIC AND OIL SEED EXTRACTS OF THE PLANT (SEIDLITZIA ROSMARINUS (AND STUDYING OF ITS BIOLOGICAL ACTIVITY

This study included isolation of some active materials from SeidlitziaRosmarinus such as tannins, saponins and volatile oils with percentage of 59.1%, 31.1%, and 9.% respectively. Also the study included the determination of minerals in SeidlitziaRosmarinus such as " Na, Ca and K" using Flame photometer. The concentrations of these minerals were (86 ppm),(65 ppm) and )467 ppm)respectively. The anti-bacterial activity study was performed for the active materials isolated from SeidlitziaRosmarinus against two genus of pathogenic bacteria, Escherichia Coli and aurousStaphylococcus using agar-well diffusion method. It appeared from this study that all of the extraction have inhibitory effect on bacteria activity. The inhibition zone diameter varies with the type of active compound, its concentration and the genus of bacteria.

ChemInform Abstract: Synthesis and Biology of N‐Thiolated β‐Lactams.

AbstractReview: 23 refs.

Water Quality To Support Potential Aquaculture Development In The Coastal Water Of Pari Island: Microbiology Aspect

Pari Island was planed for developing aquaculture therefore water quality assessments is important. One of the parameters to evaluate waters quality for aquaculture is based on the microbiology condition. Research on microbiology condition for aquaculture in Pari island waters was carried out in Mei and October 2010, stressing on total coliform, isolation pathogen bacteria, heterotrophic, and total cell bacteria. Method to analyze coliform bacteria was filtration, pathogenic bacteria identification was done after biochemical test, heterotrophic bacteria was identified by pour plate and total cell used Acridine Orange Epifluorescence Microscopy. The results indicate that abundance of total coliform cell was very high in Pari island waters about 7,000-7,640 colonies forming unit (cfu)/100 ml, heterotrophic in seawater (5-10) x 105 cfu/ml, heterotrophic in sediment (40-45) x 105 cfu/m,; and abundance of total cell was (49-9,400) x 106 cell/ml. The dog-conch (Strombus turturella) and blood-clamps (Anadara granosa) can live in Pari Island and there is a significant increase in the litter of sea grass with relatively growth in average 2 mm/day and 0.44 mm/day. During the growth of snails and clamps found several genus of pathogenic bacteria are harmless as Aeromonas, Pseudomonas, Citrobacter, Proteus, Shigella and Yersinia. Measurement of water fertility is through an observation on the content of nutrient in the waters, sediments and density of plankton parameters. The conclusion is Pari island waters productivity was in good condition and supported by litter, density of heterotrophic bacteria and plankton, then can used for marine aquaculture especially for Strombus turturella and Anadara granosa.

Synthesis and biology of N-thiolated β-lactams

N-Thiolated β-lactams are an interesting new family of bioactive agents having antibacterial, antifungal, and anticancer capabilities. Our interest in these β-lactams stems from their highly unusual structure–activity profiles and selectivity toward only a few genera of pathogenic bacteria, including Staphylococcus aureus, Bacillus anthracis, and Micrococcus. Here, we provide a complete outline on our work in the discovery and ongoing development of these compounds, starting from our initial, unexpected finding of antimicrobial activity for one of the lead compounds, to a more complete understanding of their chemical and biological mode of action and potential utility as antibacterial compounds.

Unique Centipede Mechanism of Mycoplasma Gliding

Mycoplasma, a genus of pathogenic bacteria, forms a membrane protrusion at a cell pole. It binds to solid surfaces with this protrusion and then glides. The mechanism is not related to known bacterial motility systems, such as flagella or pili, or to conventional motor proteins, including myosin. We have studied the fastest species, Mycoplasma mobile, and have proposed a working model as follows. The gliding machinery is composed of four huge proteins at the base of the membrane protrusion and supported by a cytoskeletal architecture from the cell inside. Many flexible legs approximately 50 nm long are sticking out from the machinery. The movements generated by the ATP hydrolysis cell inside are transmitted to the "leg" protein through a "gear" protein, resulting in repeated binding, pull, and release of the sialylgalactose fixed on the surface by the legs. The gliding of Mycoplasma pneumoniae, a species distantly related to M. mobile, is also discussed.

ISOLATION OF SOME ACTIVE MATERIALS FROMTrigonella foenum – graecum SEEDS AND STUDY THEIR BIOLOGICALACTIVITY

This study includes isolation of some materials from Trigoella foenum-graecum seeds and estimation of their percentage like Saponins , Volatils Oils , Glycosides , Alkaloids and proteins . The antibacterial activity study was performed for the active materials which isolated from Trigoella foenum-graecum seeds against four genus of pathogenic bacteria by using Agar–well diffusion method . It appeared from this study that all of the isolated active materials have inhibitory effect on the bacteria were used . The study also includes separation of free fatty acids from Oils of Trigonella foenum-graecum seeds estimation of fatty acids percentage by using gas chromatography techniques . Amino acids were separated from Trigoella foenum-graecum seeds by Thin Layer Chromatography ( T.L.C. ) . The study also included the determination of metals in Trigoella foenum-graecum seeds, by using the Atomic Absorption techniques as Mg , Fe , Zn , Co , Al , Cu , Se , Ni and Mn , While the determination of the metals which found in considerable amounts by using Flame Photometer technique like Ca , Na , Li and Ba

Preparation of some Benzimidazole derivatives and study of their spectrometric properties and biological activity

This research discussed the preparation of some derivatives of Benzimidazole which included Schiff base compounds (a-e). They were prepared by direct condensation between Benzimidazole and aliphatic or aromatic aldehydes. The prepared compounds were identified by Infrared spectra (I.R.), micro analysis of elements (C.H.N.), Nuclear magnetic resonance spectrum (N.M.R.) and (MS) spectrum. Antibacterial activity of the prepared compounds was measured on three genus of pathogenic bacteria. The comparative study of biological activity was done using diffusion , and antibacterial activity was noticed in some of these compounds.

Synthesis a Number of Triazene Compounds Derived From Purine and Studying their Biological Activity on Pathogenic Bacteria

In this research a number of compounds were prepared by coupling dizonium salts with purine bases. The structures of the prepared compounds were identified by ultra violet ,infra red spectra and Elemental (C.H.N) analysis .The biological activity of these compounds was investigated on five genera of pathogenic bacteria: S. aureus , Str. viridans , Ps. aeruginosa , E. coli and Sh. dysenteriae using Disc diffusion method. Also the minimum inhibitory concentration (MIC) was calculated .It was found that these compounds have medium biological effect against these genera of bacteria.

SYNTHESIS A NUMBER OF AZO COMPOUNDS DERIVED FROM GUANINE AND STUDYING THEIR BIOLOGICAL ACTIVITY ON PATHOGENIC BACTERIA

A series of compounds were prepared by coupling dizonium salts with guanine. The structures of the prepared compounds were identified by ultra violet ,infra red spectra and Elemental (C.H.N) analysis .The biological activity of these compounds was investigated on five genera of pathogenic bacteria: S. aureus , Str. viridans , Ps. aeruginosa , E. coli and Sh. dysenteriae using Disc diffusion method. Also the minimum inhibitory concentration (MIC) was calculated .It was found that these compounds have medium biological effect against these genera of bacteri Key words : Synthesis , Azo Compounds , Guanine and , Biological Activity , Bacteria

STUDY OF MICROBIAL POLLUTION IN THE ACEH COASTAL WATERS AND ITS VICINITY

Study of microbial pollution in the Aceh coastal waters and its vicinity were carried out in the period of August - September 2006. The purpose of the study is to monitor the marine and coastal environments related to the bacterial condition in Aceh waters after the tsunami disaster. The sediment and water samples were collected from 28 stations in four sites in the Aceh waters (Eastern Aceh, Northern Aceh, Western Aceh and Simeulue Islands waters), using the RV. Baruna Jaya VIII. The determination of microbial pollution was based on parameters of coliform and pathogenic bacteria. The coliform bacteria was analysed by membrane filter technique and pathogenic bacteria (Salmonella and Vibrio) by isolation method based on the selective culture media of Salmonella and TCBS agar. The results of the study showed that density of total coliform bacteria varied between 40 and 1055 CFU/100 ml with an average of 443 CFU/100 ml. Based on the pattern of the distribution of coliform bacteria it was found the highest number in Eastern Aceh with the value of 611 CFU/100 ml and the lowest number in Western Aceh with the value of 348 CFU/100 ml. Based on the density of coliform bacteria, Aceh waters was in the lower permissible level of the Indonesian and WHO standards, means that the coastal environment in Aceh waters is still in good condition. Four genera of pathogenic bacteria isolated from seawater samples were Pseudomonas, Citrobacter, Aeromonas and Proteus, and 6 genera from sediments samples were found i.e. Pseudomonas, Citrobacter, Aeromonas, Yersinia, Proteus and Vibrio. The pathogenic bacteria from the samples such as Salmonella typhy and Vibrioparahaemoliticus had low pathogenic potential. This indicated that the risk of pathogenic bacterial contamination in Aceh and its vicinity waters were relatively low, therefore, the conditions of coastal and marine environments were relatively in good condition.&#x0D;

Conjugal Transfer of Plasmid R6K γ ori Minireplicon Derivatives from Escherichia coli to Various Genera of Pathogenic Bacteria

Three R6K-derived gamma ori minireplicons were successfully transferred by conjugation from Escherichia coli to several species of pathogenic bacteria. The pFL129 replicon encodes the wild-type initiation replication protein pi, while plasmids pFL130 and pAG101 encode mutant forms of the pi protein conferring the plasmid copy-up phenotype. Plasmids could be transferred to all recipient species tested, although high efficiency conjugal transfer was only obtained with genera of the Enterobacteriaceae. The efficiency of plasmid transfer to all recipients was lower for the copy-up derivatives, pFL130 and pAG101, than for pFL129. The three gamma ori replicons were stably maintained in all transconjugants except pFL129 in Listeria monocytogenes. The two mutant plasmids retained their copy-up phenotype in the new bacterial hosts.