Search

The primary objective of the present study was to elucidate the genetic diversity of lentil-nodulating rhizobia in Iran, utilizing an amalgamation of molecular techniques. A total of 116 rhizobia strains were isolated from soil and nodule samples collected from lentil-growing regions of Iran, and their genetic makeup was analyzed using BOX-PCR and RAPD techniques, as well as PCR/RFLP analysis of the 16S–23S IGS region and sequencing of 16S rRNA and glnII genes. The results showed that the rhizobia strains belonged to two different species, Rhizobium leguminosarum and R. laguerreae, with R. leguminosarum being the more predominant species. The strains of R. leguminosarum and R. laguerreae were grouped into different classes using BOX and RAPD techniques, which indicate their distinct genetic composition and evolutionary relationships. The genetic diversity was influenced by geographic location, indicating that different regions may have unique rhizobia populations with distinct genetic characteristics. The high level of genetic diversity observed among the lentil-nodulating rhizobia in Iran underscores the importance of using locally adapted rhizobia strains in lentil cultivation.

Bacterial soft rots are amongst the most economically important diseases that cause significant yield losses in various crops. A clear identification of the causal agents is required to develop management strategies. In 2022 and 2023, after the widespread occurrence of soft rot disease in sugar beet fields in the Firuzan region, Hamedan Province, Iran, the current study was conducted to identify and characterize the causal agents. A total of 38 bacterial isolates were obtained from sugar beet plants with soft rot symptoms and subjected to biochemical and phenotypical characterization and pathogenicity tests on healthy slices from potato tubers and sugar beet taproots. Twelve isolates from this study along with the type strain Pectobacterium carotovorum ICMP 5702 were selected for subsequent screening by BOX‐PCR. Six isolates were chosen for sequencing the 16SrRNA gene and phylogenetic analysis. In BLAST analyses, the pathogenic isolates S2, S9, S22, S11, S23 and 111 showed the highest similarity values (≥99%) with the reference sequences of Raoultella terrigena, Klebsiella michiganensis, Erwinia (Winslowiella) iniecta, Pantoea agglomerans and P. carotovorum, respectively. These isolates induced soft rot and maceration on plant materials from five species (bell pepper fruits, garlic cloves and slices from sugar beet taproot, potato tubers and carrot roots) 72 h after inoculation. In the greenhouse experiment, they caused soft rot symptoms in the taproots of 2‐month‐old sugar beet plants 3 weeks after inoculation. These soft rot agents had Gram‐negative, catalase‐positive and oxidase‐negative reactions, grew under both aerobic and anaerobic conditions, tolerated and grew at 37°C and 5% NaCl. In general, the results of this research showed that in addition to Pectobacterium, four other genera from the order Enterobacterales including Erwinia, Pantoea, Klebsiella and Raoultella, are amongst the causes of soft rot in sugar beet in Firuzan region of Hamedan. [ABSTRACT FROM AUTHOR]

Biodegradation of phenol is an effective method for removing this toxicant from contaminated sites. Phenol is a toxic compound for living cells, so many bacteria degrade phenol in relatively low concentrations, up to 0.75 g L−1. The Rhodococcus opacus strain 1CP is an effective destructor of a wide range of pollutants. In the absence of a carbon source in the medium, cells of the R. opacus 1CP strain easily form cyst-like resting cells (CLC). The purpose of this work was to evaluate the viability of cells during long-term storage and the efficiency of the process of phenol destruction by R. opacus 1CP cells germinating after dormancy. Resting cells were obtained by simple cultivation in a rich medium followed by storage under static conditions. This is a simple approach to obtain a large amount of biomass. Decomposition of phenol proceeded via catechol followed by ortho-cleavage of aromatic ring. The induction of three phenol hydroxylases was detected by RT-PCR in cells germinated in a mineral medium with phenol as the carbon source. The stability of the genome of cells germinating after dormancy is shown by box-PCR. Dormant R. opacus 1CP cells, both suspended and immobilized, can be directly used for the decomposition of phenol after 4–12 months storage. In addition to phenol, after 9 months of storage, immobilized germinating cells easily metabolized 4-chlorophenol and 2,4,6-trichlorophenol. The results demonstrate a potential and simple approach toward achieving long-term storage of cells for further use in bioremediation. [ABSTRACT FROM AUTHOR]

Biodegradation of phenol is an effective method for removing this toxicant from contaminated sites. Phenol is a toxic compound for living cells, so many bacteria degrade phenol in relatively low concentrations, up to 0.75 g L−1. The Rhodococcus opacus strain 1CP is an effective destructor of a wide range of pollutants. In the absence of a carbon source in the medium, cells of the R. opacus 1CP strain easily form cyst-like resting cells (CLC). The purpose of this work was to evaluate the viability of cells during long-term storage and the efficiency of the process of phenol destruction by R. opacus 1CP cells germinating after dormancy. Resting cells were obtained by simple cultivation in a rich medium followed by storage under static conditions. This is a simple approach to obtain a large amount of biomass. Decomposition of phenol proceeded via catechol followed by ortho-cleavage of aromatic ring. The induction of three phenol hydroxylases was detected by RT-PCR in cells germinated in a mineral medium with phenol as the carbon source. The stability of the genome of cells germinating after dormancy is shown by box-PCR. Dormant R. opacus 1CP cells, both suspended and immobilized, can be directly used for the decomposition of phenol after 4–12 months storage. In addition to phenol, after 9 months of storage, immobilized germinating cells easily metabolized 4-chlorophenol and 2,4,6-trichlorophenol. The results demonstrate a potential and simple approach toward achieving long-term storage of cells for further use in bioremediation.

Japanese quince trees are grown as ornamental plants in Iran, in parks and in orchards close to stone fruit and pome fruit trees. Shoots of Japanese quince (Chaenomeles japonica) showing sunken brown canker symptoms were observed and collected near Sari, the center of Mazandaran province in the North of Iran, during the 2016 growing season. Gram negative bacteria isolated from symptomatic tissues were similar to Pseudomonas syringae pv. syringae (Pss) were pathogenic on Japanese quince and on quince (Cydonia oblonga) seedlings after artificial inoculation, and were re-isolated from diseased hosts. Phylogenetic tree construction using partial sequences of ITS and rpoD genes showed that the Japanese quince isolates were in the same clade as Pss strains. The isolates had ice nucleation activity, and the InaK gene was amplified successfully. According to the results of phenotypic and genotypic characteristics, genomic DNA fingerprinting using REP-PCR, BOX-PCR and IS50-PCR and isolation of total cell proteins, we conclude that Pss is the causal agent of canker of the Japanese quince trees. Therefore, Japanese quince is a new host for Pss causing bacterial canker on many different host plants.

Abstract Background Rhizosphere soil is a crucial niche for the diverse beneficial microbial communities in plant-microbe interactions. This study explores the antagonistic potential and diversity of the rhizosphere soil bacteria from commercial tea estates of Assam, India which comes under the Indo-Burma mega-biodiversity hotspot. Rhizosphere soil samples were collected from six different tea estates to isolate the bacteria. The bacterial isolates were subjected to evaluate for the antagonistic activity against fungal pathogens. The potential isolates were investigated for chitinase production and the presence of chitinase gene. The bacterial genetic diversity was studied by Amplified Ribosomal DNA Restriction Analysis (ARDRA) and BOX-PCR fingerprinting. Results A total of 217 rhizobacteria were isolated from tea rhizosphere soil, out of which 50 isolates exhibited the potential antagonistic activity against fungal pathogens. Among them, 12 isolates showed extracellular chitinase activity and the presence of chitinase genes. The chitinase genes were sequenced and the analysis of the sequences was performed by using PDB protein databank at the amino acid level. It showed the presence of ChiA and ChiA74 gene in the 6 most potent isolates which are involved in the hydrolysis of chitin. These isolates also exhibited antagonistic activity against all tested fungal pathogens. The diversity of 50 antagonistic bacterial isolates were analyzed through ARDRA and BOX-PCR fingerprinting. Diversity analysis and molecular identification of the rhizosphere isolates revealed that these antagonistic isolates predominantly belonged to the genus Bacillus followed by Enterobacter, Serratia, Lysinibacillus, Pseudomonas, and Burkholderia. Conclusion The present study establishes that rhizobacteria isolated from the poorly explored tea rhizosphere soil could be a rich reservoir for the investigation of potential antagonistic bacterial candidates for sustainable agricultural and industrial applications.

Japanese quince trees are grown as ornamental plants in Iran, in parks and in orchards close to stone fruit and pome fruit trees. Shoots of Japanese quince (Chaenomeles japonica) showing sunken brown canker symptoms were observed and collected near Sari, the center of Mazandaran province in the North of Iran, during the 2016 growing season. Gram negative bacteria isolated from symptomatic tissues were similar to Pseudomonas syringae pv. syringae (Pss) were pathogenic on Japanese quince and on quince (Cydonia oblonga) seedlings after artificial inoculation, and were re-isolated from diseased hosts. Phylogenetic tree construction using partial sequences of ITS and rpoD genes showed that the Japanese quince isolates were in the same clade as Pss strains. The isolates had ice nucleation activity, and the InaK gene was amplified successfully. According to the results of phenotypic and genotypic characteristics, genomic DNA fingerprinting using REP-PCR, BOX-PCR and IS50-PCR and isolation of total cell proteins, we conclude that Pss is the causal agent of canker of the Japanese quince trees. Therefore, Japanese quince is a new host for Pss causing bacterial canker on many different host plants. [ABSTRACT FROM AUTHOR]

Klebsiella pneumoniae is an opportunistic pathogen responsible for a significant proportion of nosocomial and community-acquired infections. Genotypic variation in K. pneumoniae populations is a major barrier to control public health risk associated with pathogen. In this work, thirty K. pneumoniae were recovered from hospital and were tested for their resistance to antibiotics. Genetic variability of the isolates was performed using PCR based on genes coding for porins and efflux pumps, (GTG)5 and BOX repetitive sequences. K. pneumoniae showed heterogenicity of resistance to antibiotics based on gender or specimen type. Further, out of 30 isolates, 25 different profiles were found and 83.33% are multidrug-resistant. PCR detection of genes coding for porins and efflux pumps revealed seven different genotypes and strong correlation between antibiotics resistance profiles and investigated genes. PCR genomic fingerprinting showed high genetic diversity of K. pneumoniae. BOX-PCR and (GTG)5 generated 18 and 19 clusters with discriminatory indexes 0.97 and 0.98, respectively at 80% of similarity. K. pneumoniae clinical isolates showed high phenotypic and genetic variability, and many strains can be circulating simultaneously. This genetic variability should be taken into consideration when designing strategies for controlling K. pneumoniae outbreaks. In addition, a significant correlation, was detected for the first time, between (GTG)5-genotyping and antibiotic resistance patterns of K. pneumoniae and could be valuable in the prediction of antibiotic resistance profiles of K. pneumoniae.

This study aims to test the toxicity of some metallic elements on Salmonella enterica strains and their power to grow and to develop a biofilm to overcome this environmental stress. From 50 selected strains of Salmonella, 70% belong to the Kentucky serotypes that is the most frequent one, followed by the other serotypes such as Amsterdam 6%, anatum 4%, derby 4% Enteritidis 4%, Zanzibar 4%, typhyrimium 2%, gallinaruim 2%, inbondaka 2% and Newport 2%. All the strains have presented the invA invasion gene involved in the virulence and Salmonella infection. Genotypic BOX-PCR analysis of these strains showed 18 profiles, with a discrimination index of 0.93. The Salmonella growth has mainly revealed that the variation of the rates of different metallic elements showed a significant influence on the Salmonella growth. The qualitative, quantitative study and biofilm tubes showed that 40% of the strains have a strong capacity to form biofilm, and the wild-type phenotypes (RDAR; rigid film; Strong), This phenotype varies according to the nature and the concentration of the metal (0.1 mM–1 mM) considered. In the presence of copper, zinc, cobalt, and chromium, the Salmonella strains showed a potent capacity to form a biofilm with a slight variation in the wild-type phenotype. However, when chromium rates increased, Salmonella loses the RDAR morphotype. Addition of mercury and cadmium in the growth medium reduced the production of Salmonella biofilm by around 14 and 15%, respectively, if compared with the control free of metals. [ABSTRACT FROM AUTHOR]

Symbiotic diazotrophic bacteria collectively called "rhizobia" can associate with legumes and form specialized structures in the roots, called nodules, where the biological nitrogen fixation (BNF) process takes place. Common bean (Phaseolus vulgaris L.) is a major protein source in the diet of the population of many countries such as Brazil and can benefit from the BNF process, but there is still little knowledge about the diversity and effectiveness of indigenous microsymbionts. In this study, the diversity and the nitrogen fixation ability of bacterial isolates trapped by common bean nodules in 14 municipalities of Mato Grosso do Sul state, Central-Western region, comprising three Brazilian biomes were investigated. The DNA profiles (BOX-PCR) of 82 isolates indicated outstanding diversity, with 12 main clusters and 36 isolates occupying single positions, joined at a final level of similarity of less than 20%. The 16S rRNA phylogeny of 56 isolates representing the DNA profiles indicated ten genera, with 38 isolates identified as "classical rhizobia" and Agrobacterium, and the remaining 18 belonging to six other genera. The 38 isolates had their glnII gene sequenced and were evaluated for the capacity of nodulation and BNF with common bean, and only 12 formed effective nitrogen-fixing nodules, five positioned in the R. etli and six in the R. tropici clades, and one of Agrobacterium. These results highlight the promiscuity of common bean in capturing a variety of microbial species in their nodules, whose function has not been well elucidated yet. Only one-fifth of the isolates were effective in fixing nitrogen, which might explain the frequently reported low rates of contribution of the BNF with this legume, an intriguing paradigm in the evolution of the symbiosis. [ABSTRACT FROM AUTHOR]

Mohamed F El-Badawy,1,2 Shaymaa W El-Far,1 Shaker S Althobaiti,3 Fatma I Abou- Elazm,2 Mohamed M Shohayeb4 1Division of Pharmaceutical Microbiology, Department of Pharmaceutics and Industrial Pharmacy, College of Pharmacy, Taif University, Taif, Kingdom of Saudi Arabia; 2Department of Microbiology and Immunology, Faculty of Pharmacy, Misr University for Science and Technology, 6th of October City, Egypt; 3King Fahad Armed Forces Hospital, Jeddah, Kingdom of Saudi Arabia; 4Department of Microbiology and Biotechnology, Faculty of Pharmacy, Delta University for Science and Technology, Gamasa, EgyptCorrespondence: Mohamed F El-BadawyDivision of Pharmaceutical Microbiology, Department of Pharmaceutics and Industrial Pharmacy, College of Pharmacy, Taif University, Kingdom of Saudi ArabiaTel +20-103-205-9964Email m.elbadawy@tu.edu.saBackground and Objective: The emergence of carbapenem-resistant K. pneumoniae (CRKP) continues to escalate and is alarming because of the emergence of pan drug-resistant strains. The objective of this study was to investigate the existence of 12 carbapenemase genes among CRKP clinical isolates.Methods: Ninety-six Klebsiella spp. clinical isolates were collected. The isolates were identified phenotypically and genotypically. These isolates were screened for susceptibility to 24 different antibiotics. The modified Hodge test (MHT) and the Carba Nordmann/Poirel (NP) test were used to phenotypically screen carbapenem-resistant strains for carbapenemase production. Phenotypic characterization of carbapenemases was performed using the combined disk synergy test (CDST). Additionally, the presence of 12 carbapenemase genes in CRKP isolates was investigated. The DNA sequence of blaNDM and blaGES genes was determined. The BOX-PCR technique was used to determine the clonal relationship between CRKP isolates.Results: All carbapenem-resistant isolates were related to K. pneumoniae. Susceptibility testing showed that 19.79% (19/96) of the collected isolates were carbapenem-resistant. Of the CRKP isolates, 68.42% (13/19) tested positive for the MHT and Carba NP test. CDST showed that 42.11% (8/19), 63.16% (12/19), 47.37% (9/19), and 73.68% (14/19) of the CRKP isolates tested positive for the inhibitory effect of clavulanic acid, sulbactam, phenylboronic acid, and tazobactam, respectively, while 84.21% (16/19) and 68.42% (13/16) tested positive for the inhibitory effect of EDTA and mercaptopropionic acid, respectively. It was found that 10.53% (2/19) of the isolates tested positive for the inhibitory effect of sodium chloride. Molecular investigation of carbapenemases showed that 26.32% (5/19), 73.68% (14/19), 21.05% (4/19), 10.53% (2/19), and 5.26% (1/19) of the isolates tested positive for blaNDM, blaOXA-48, blaOXA-181, blaOXA-51, and blaOXA-23, respectively. None of the isolates tested positive for blaOXA-40 and blaOXA-58. Two allelic variants of blaNDM (blaNDM-1 and blaNDM-25) were detected. BOX-PCR revealed high clonal relatedness between CRKP isolates.Conclusion: MHT was more sensitive than Carba NP test for evaluating carbapenemase production and class D carbapenemase genes were the most prevalent of the 12 carbapenemase genes that were evaluated.Keywords: carbapenemases, CRKP, BOX-PCR, blaNDM-25, MHT, CDST

Bacterial blight and leaf spot of geraniums is a destructive disease of cultivated Pelargonium species around the world. During 2020 to 2021, surveys were conducted in seven geranium-growing provinces of Iran to monitor the status of bacterial blight and leaf spot disease. The disease was observed in six surveyed provinces varying in the extent of occurrence and severity. Twenty-two gram-negative pale-yellow bacterial strains resembling members of Xanthomonas were isolated from symptomatic leaves and stems. Pathogenicity and host range assays showed that the bacterial strains were pathogenic on Pelargonium grandiflorum , P. graveolens , P. peltatum , and P. zonale . All strains were positive for a PCR test using the primer pair XcpM1/XcpM2, which is specific for X. hortorum pv. pelargonii . Phylogenetic analysis using the sequences of gyrB and lepA genes showed that the 22 strains clustered in a clade among the sequences of X. hortorum pv. pelargonii strains retrieved from GenBank but were distinct from the other pathovars of X. hortorum . BOX-PCR-based fingerprinting using BOX-A1R primer revealed that the strains isolated in this study were grouped into two clusters, while no distinct correlation was observed between the host/area of isolation and BOX-PCR fingerprinting. None of the strains obtained in this study nor the reference strain of the pathogen produced bacteriocin against each other. Results obtained in this study shed light on the geographic distribution, taxonomic status, and host range of the bacterial blight and leaf spot pathogen of geraniums in Iran, paving the path for further research on disease management., Competing Interests: The author(s) declare no conflict of interest.

Mangroves are highly productive unique ecosystems harboring diverse unexplored microbial communities that play crucial roles in nutrient cycling as well as in maintaining ecosystem services. The mangrove-associated microbial communities transform the dead vegetation into nutrient sources of nitrogen, phosphorus, potash, etc. To understand the genetic and functional diversity of the bacterial communities involved in nitrogen cycling of this ecosystem, this study explored the diversity and distribution of both the nitrogen fixers and denitrifiers associated with the rhizospheres of Avicennia marina, Rhizophora mucronata, Suaeda maritima, and Salicornia brachiata of the Pichavaram mangroves. A combination of both culturable and unculturable (PCR-DGGE) approaches was adopted to explore the bacterial communities involved in nitrogen fixation by targeting the nifH genes, and the denitrifiers were explored by targeting the nirS and nosZ genes. Across the rhizospheres, Gammaproteobacteria was found to be predominant representing both nitrogen fixers and denitrifiers as revealed by culturable and unculturable analyses. Sequence analysis of soil nifH, nirS and nosZ genes clustered to unculturable, with few groups clustering with culturable groups, viz., Pseudomonas sp. and Halomonas sp. A total of 16 different culturable genera were isolated and characterized in this study. Other phyla like Firmicutes and Actinobacteria were also observed. The PCR-DGGE analysis also revealed the presence of 29 novel nifH sequences that were not reported earlier. Thus, the mangrove ecosystems serve as potential source for identifying unexplored novel microbial communities that contribute to nutrient cycling. [ABSTRACT FROM AUTHOR]

Pseudomonas fluorescens is ubiquitous in nature and having diverse mechanism of action which ameliorates the biotic and abiotic stresses and possess plant growth promotion activities in agricultural crops. Out of fifty isolates of fluorescent pseudomonads collected from saffron and paddy crops, thirty-five isolates were identified as P. fluorescens on the basis of phenotypic test and species-specific PCR. Species-specific-PCR assay provided a rapid, specific and sensitive alternative to conventional culture methods for the identification of P. fluorescens. Cluster analysis of the collected thirty-five isolates of P. fluorescens by rep-PCR showed considerable genetic diversity. Twenty and twenty-one banding patterns were obtained for both the BOX and REP primers. The present study shall be useful to correlate the genetic diversity with functional diversity of P. fluorescens to explore the possibilities of suitable disease management strategies for a particular crop in sustainable agriculture. [ABSTRACT FROM AUTHOR]

Background: Rhizosphere soil is a crucial niche for the diverse beneficial microbial communities in plant-microbe interactions. This study explores the antagonistic potential and diversity of the rhizosphere soil bacteria from commercial tea estates of Assam, India which comes under the Indo-Burma mega-biodiversity hotspot. Rhizosphere soil samples were collected from six different tea estates to isolate the bacteria. The bacterial isolates were subjected to evaluate for the antagonistic activity against fungal pathogens. The potential isolates were investigated for chitinase production and the presence of chitinase gene. The bacterial genetic diversity was studied by Amplified Ribosomal DNA Restriction Analysis (ARDRA) and BOX-PCR fingerprinting. Results: A total of 217 rhizobacteria were isolated from tea rhizosphere soil, out of which 50 isolates exhibited the potential antagonistic activity against fungal pathogens. Among them, 12 isolates showed extracellular chitinase activity and the presence of chitinase genes. The chitinase genes were sequenced and the analysis of the sequences was performed by using PDB protein databank at the amino acid level. It showed the presence of ChiA and ChiA74 gene in the 6 most potent isolates which are involved in the hydrolysis of chitin. These isolates also exhibited antagonistic activity against all tested fungal pathogens. The diversity of 50 antagonistic bacterial isolates were analyzed through ARDRA and BOX-PCR fingerprinting. Diversity analysis and molecular identification of the rhizosphere isolates revealed that these antagonistic isolates predominantly belonged to the genus Bacillus followed by Enterobacter, Serratia, Lysinibacillus, Pseudomonas, and Burkholderia. Conclusion: The present study establishes that rhizobacteria isolated from the poorly explored tea rhizosphere soil could be a rich reservoir for the investigation of potential antagonistic bacterial candidates for sustainable agricultural and industrial applications. [ABSTRACT FROM AUTHOR]

Introduction: Proteus mirabilis is one of the common causes of UTI.Multiple molecular methods are used to genotype bacteria.The polymerase chain reaction method is based on repeated sequences using BOXA1R primers for differentiation of bacteria. This study aimed to evaluate the genetic ‎diversity of protease mirabilis isolated from urine specimens. Materials & Methods: In this descriptive cross-sectional study, 60 isolates protease mirabilis were ‎identified from urine specimens using biochemical tests. DNA samples were extracted and tested for BOX-PCR. Findings: The tree diagram or dendrogram of BOX-PCR was drawn and the results showed that all strains were ‎segregated into 7 separate clusters at a similarity level of 57%‎. There were three isolates in the first group, nine in the second group, 18 in the third group, two ‎ in the fourth group, 11 in the fifth group, one in the sixth group, and 16 isolates ‎in the seventh group.‎ Dandrogram analysis revealed that the strains belonging to a serovar are subtracted from each other.‎ Discussion & Conclusions: This method demonstrated that molecular fingerprinting with BOXA1R primers is useful for typing bacterial ‎isolates from different origins.‎ Moreover, it has a really efficient differentiation power, it can be used effectively in epidemiological studies, and ‎trace source of infection and taxonomy.‎

This study aimed to evaluate the genetic diversity of bacterial community associated to different sugarcane genotypes, association habitat and phenological phase of the culture, as well as to isolate, to identify and to characterize your potential for plant growth-promoting. Root and rhizospheric soil samples from RB 92579 and RB 867515 varieties were collected at 120 and 300 days after regrowth (DAR). The diversity of bacterial was evaluated through of the 16S rRNA and nifH genes. We found greater genetic diversity in the root endophytic habitat at 120 DAR. We identify the genera Burkholderia sp., Pantoea sp., Erwinia sp., Stenotrophomonas sp., Enterobacter sp. and Pseudomonas sp. The genera Bacillus sp. and Dyella sp. were only identified in the variety RB 92579. We found indices above 50% for biological nitrogen fixation, production of indole acetic acid and phosphate solubilization, showing that the use of these bacteria in biotechnological products is very promising. [ABSTRACT FROM AUTHOR]

Copyright of Egyptian Journal of Botany is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Genetic and metabolic diversities of rhizobacteria are the fundamental sources for their adaptation to cope with abiotic and biotic stresses in order to enhance growth and health of plants in the soil. Thus, this study was initiated to assess the genetic and metabolic diversities of rhizobacteria isolated from plants grown in degraded soil through BOX-PCR and partial sequencing of 16S rRNA genes. A total of eighty isolates were recovered and subjected to phenotypic profiling of carbohydrate and amino acid utilization, BOX PCR and 16S rRNA profiling. The phenotypic profiling showed remarkable metabolic versatility with Ochrobactrum spp, Pseudomonas spp and Klebsiella spp, and BOX-PCR showed greater discriminatory power for fingerprinting of rhizobacterial isolates with high degree of polymorphism. Bacillus spp showed the highest Simpson's diversity Index. The 16S rRNA genes sequence assigned the rhizobacteria to phyla Proteobacteria with Gammaproteobacteria and Alphaproteobacteria classes and Firmicutes with Bacilli class. The data also showed that the most dominant species were Pseudomonas and Ochrobactrum. Genetic and metabolic diversities of the rhizobacterial isolates reveal the potential of these microbes for plant growth improvement under water deficient soil after testing other inoculant traits.

Klebsiella pneumoniae is an opportunistic pathogen responsible for a significant proportion of nosocomial and community-acquired infections. Genotypic variation in K. pneumoniae populations is a major barrier to control public health risk associated with pathogen. In this work, thirty K. pneumoniae were recovered from hospital and were tested for their resistance to antibiotics. Genetic variability of the isolates was performed using PCR based on genes coding for porins and efflux pumps, (GTG) 5 and BOX repetitive sequences. K. pneumoniae showed heterogenicity of resistance to antibiotics based on gender or specimen type. Further, out of 30 isolates, 25 different profiles were found and 83.33% are multidrug-resistant. PCR detection of genes coding for porins and efflux pumps revealed seven different genotypes and strong correlation between antibiotics resistance profiles and investigated genes. PCR genomic fingerprinting showed high genetic diversity of K. pneumoniae. BOX-PCR and (GTG) 5 generated 18 and 19 clusters with discriminatory indexes 0.97 and 0.98, respectively at 80% of similarity. K. pneumoniae clinical isolates showed high phenotypic and genetic variability, and many strains can be circulating simultaneously. This genetic variability should be taken into consideration when designing strategies for controlling K. pneumoniae outbreaks. In addition, a significant correlation, was detected for the first time, between (GTG) 5 -genotyping and antibiotic resistance patterns of K. pneumoniae and could be valuable in the prediction of antibiotic resistance profiles of K. pneumoniae. [ABSTRACT FROM AUTHOR]

One hundred and ten samples of the tap water in Baquba city were collection. Ten isolates were obtained. The results of the sensitivity test showed that 10 isolates were multidrug, 10 isolates exhibited moderate resistance ranging from 5-8 antagonists. Through the use of the RAPD-PCR profiling system, the vast majority of Escherichia coli strains under study have large genomes and high virulence factors by belonging to group A2. Results of genetic profiling using the ERIC-PCR and BOX-PCR system showed several groups of isolates were identified as having a genetic variation and B2 group was given the highest proportion of ERIC-PCR system, 70% in ERIC While A2 group was given the highest proportion of BOX-PCR system, 40% in the BOX indicating that there is a negative spread The present study indicates that there is a correlation between taxonomic systems was evident by the distribution of isolates in each pattern and group. [ABSTRACT FROM AUTHOR]

Background and Objective: The emergence of carbapenem-resistant K. pneumoniae (CRKP) continues to escalate and is alarming because of the emergence of pan drug-resistant strains. The objective of this study was to investigate the existence of 12 carbapenemase genes among CRKP clinical isolates. Methods: Ninety-six Klebsiella spp. clinical isolates were collected. The isolates were identified phenotypically and genotypically. These isolates were screened for susceptibility to 24 different antibiotics. The modified Hodge test (MHT) and the Carba Nordmann/Poirel (NP) test were used to phenotypically screen carbapenem-resistant strains for carbapenemase production. Phenotypic characterization of carbapenemases was performed using the combined disk synergy test (CDST). Additionally, the presence of 12 carbapenemase genes in CRKP isolates was investigated. The DNA sequence of blaNDM and blaGES genes was determined. The BOX-PCR technique was used to determine the clonal relationship between CRKP isolates. Results: All carbapenem-resistant isolates were related to K. pneumoniae. Susceptibility testing showed that 19.79% (19/96) of the collected isolates were carbapenem-resistant. Of the CRKP isolates, 68.42% (13/19) tested positive for the MHT and Carba NP test. CDST showed that 42.11% (8/19), 63.16% (12/19), 47.37% (9/19), and 73.68% (14/19) of the CRKP isolates tested positive for the inhibitory effect of clavulanic acid, sulbactam, phenylboronic acid, and tazobactam, respectively, while 84.21% (16/19) and 68.42% (13/16) tested positive for the inhibitory effect of EDTA and mercaptopropionic acid, respectively. It was found that 10.53% (2/19) of the isolates tested positive for the inhibitory effect of sodium chloride. Molecular investigation of carbapenemases showed that 26.32% (5/19), 73.68% (14/19), 21.05% (4/19), 10.53% (2/19), and 5.26% (1/19) of the isolates tested positive for blaNDM, blaOXA-48, blaOXA-181, blaOXA-51, and blaOXA-23, respectively. None of the isolates tested positive for blaOXA-40 and blaOXA-58. Two allelic variants of blaNDM (blaNDM-1 and blaNDM-25) were detected. BOX-PCR revealed high clonal relatedness between CRKP isolates. Conclusion: MHT was more sensitive than Carba NP test for evaluating carbapenemase production and class D carbapenemase genes were the most prevalent of the 12 carbapenemase genes that were evaluated. [ABSTRACT FROM AUTHOR]

Introduction: Salmonella is one of the most important causes of gastroenteritis in humans. Salmonella enterica Serovar Typhimurium has many hosts in addition to humans, and its prevalence in the community is high. The aim of the study was comparing the genetic diversity of Salmonella enterica serovar Typhimurium isolated from human fecal samples by both of ERIC-PCR and BOX-PCR method. Methods: In this cross-sectional study, 60 Salmonella enterica serovar Typhimurium were obtained from the human fecal samples. These strains were identified by standard microbiological and biochemical tests. Then, ERIC-PCR and BOX-PCR were carried out for determination of molecular relatedness of Salmonella enterica serovar Typhimurium using specific primers. Results: The results showed that all 60 Salmonella enterica serovar Typhimurium were separable using ERIC 1, ERIC 2 and BOXAIR. In electrophoresis, 2-11 bands with 20-3200bp for ERIC-PCR and 2-10 bands with 200-1500bp for BOX-PCR were observed. Therefore, 13 different clusters (C1-C13) in ERIC-PCR and 21 different clusters (C1-C21) in BOX-PCR were identified. Conclusion: The results showed that Salmonella enterica serovar Typhimurium strains were non-homolog. Therefore, ERIC-PCR and BOX-PCR methods are appropriate methods for molecular typing of Salmonella strains and determine the original infection source for the epidemiological survey as well as infection prevention program.

This study evaluates the clonal heterogeneity and efficacy of BOX-PCR and (GTG)5-PCR for DNA-based typing of Escherichia coli strains isolated from feces of chickens in IRI. Fecal samples were collected from chicken husbandry followed by E. coli isolation through biochemical tests. Isolates were finger printed by BOX-A1 and (GTG)5 primers. Dendrograms were generated based on 80% similarity and Shannon-Weaver index was calculated. One hundred and six E. coli isolates were obtained from chicken"s fecal sample. By (GTG)5 primer, of 106 isolates, two isolates were untypeable, while 104 isolates generated 100 unique, and 2 duplicate profiles. The dendrogram generated six clusters (G1-G6). With BOX-PCR, 106 E. coli isolates revealed 50 unique BOX profiles, in addition to 22 repetitive profiles, while 12 isolates were untypeable. Based on the bands and dendrogram, the 106 strains were grouped into six clusters (B1-B6). Shannon-Weaver index was 4.665 for (GTG)5- PCR and 0.281 for BOX-PCR. (GTG)5-PCR revealed complex clonal heterogeneity, more discriminatory power, less untypeable isolates, higher Shannon-Weaver index, and less isolates with the same profile in comparison to BOX-PCR. Although (GTG)5-PCR proved to be a powerful typing method, it is recommended to combine two or more different typing methods for higher discriminatory power.

Background: The genome of Enterococcus has a large number of repetitive sequences that are randomly distributed over DNA. In ERIC-PCR, a separate pattern is obtained for each strain and is considered a separate type. Prokaryotic and eukaryotic genomes include dispersed repeat sequences that are relatively short non-coding, and dispersed in the bacterial genome. BOX-PCR and ERIC-PCR primers are complementary to these repeat sequences and allow for dedicated binding and unique BOX-PCR fingerprint patterns and ERIC-PCR with reproducibility capability. Methods: In this cross-sectional descriptive study, based on previous studies and 95% confidence level using the formula n = z2P (1-P)/d2 and acceptable error 0.05, total of 60 Enterococcal Faecalis strains were cultured from sterile specimens on KF agar medium and incubated at 37°C for 24h and were identified by biochemical tests of suspected Enterococcal Faecalis. DNA samples were extracted and BOX-PCR and ERIC-PCR tests were performed. Results: All strains were distinguished in 25 distinct clusters at the level of similarity of 58%. Also, by analyzing the ERIC-PCR results, all strains were segregated into 15 separate clusters at a similar level of 58%. Conclusion: Molecular fingerprinting with BOX-PCR has a better subtraction and differentiation than ERICPCR for typing bacterial isolates and is widely used in epidemiological studies and trace source of infection and taxonomy. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to estimate the level of genomic and phenotypic diversity as well as the genus and species position of bacterial strains isolated from root nodules of Lembotropis nigricans (family Fabaceae). Methods: The genomic diversity of studied L. nigricans nodule symbionts was examined by using BOX-PCR and AFLP (amplified fragment length polymorphism) fingerprinting techniques. To assign bacteria to the genus, numerical analysis of phenotypic features and comparative analysis of 16S rDNA sequences were performed. The comparative analysis of combined atpD, dnaK, gyrB, and rpoB gene sequences (multilocus sequence analysis, MLSA) was used to determine the most closely related species to the studied bacteria. Results: Both BOX-PCR and AFLP techniques revealed a high level of genomic heterogeneity of L. nigricans nodulators. Among 33 studied bacteria, 32 genotypes were delineated by the AFLP method and 27 genotypes were identified by the BOX-PCR fingerprinting. The numerical analysis of 86 phenotypic characteristics of L. nigricans nodule isolates and reference rhizobia showed that studied bacteria belong to the genus Bradyrhizobium. Affiliation of L. nigricans nodule isolates to the genus Bradyrhizobium was supported by comparative analysis of 16S rDNA sequences and the concatenation of atpD, dnaK, gyrB, and rpoB gene sequences. MLSA indicated also that L. nigricans microsymbionts are members of Bradyrhizobium japonicum. Conclusion: L. nigricans root nodule symbionts are members of Bradyrhizobium japonicum and exhibit high phenotypic and genomic diversity important for their survival in soil. [ABSTRACT FROM AUTHOR]

Aim: Tea (Camellia sinensis (L.) O. Kuntze) is an economically important caffeine‐containing beverage crop with massive plantation in the Northeast corner of the agroclimatic belt of India. The main aim of the work was to isolate, identify and characterize the native plant growth promoting endophytes associated with tea for future microbe based bioformulation. Methods and Results: A total of 129 endophytic bacteria were isolated and characterized for plant growth promoting traits such as indole‐3‐acetic acid (IAA), phosphate solubilization, ammonia production, biocontrol traits like siderophore and extracellular enzyme production. BOX‐PCR fingerprinting was used to differentiate the various bacterial isolates obtained from six different tea species. 16S rRNA sequencing and blast analysis showed that these isolates belonged to different genera, that is, Bacillus, Brevibacterium, Paenibacillus and Lysinibacillus. Lysinibacillus sp. S24 showed the highest phosphate solubilization and IAA acid production efficiency of 268·4 ± 14·3 and 13·5 ± 0·5 µg ml−1, respectively. Brevibacterium sp. S91 showed the highest ammonia production of 6·2 ± 0·5 µmol ml−1. Chitinase, cellulase, protease and pectinase activities were shown by 4·6, 34·1, 27·13 and 13·14% of the total isolates, respectively. Similarly, 41% of the total isolates were positive for 1‐aminocyclopropane‐1‐carboxylic acid (ACC) deaminase activity. Further, the potent PGP isolates, S24 and S91 were able to enhance the vegetative parameters such as dry/fresh weight of root and shoot of tea plants in nursery conditions. Conclusion: Our findings corroborate that tea endophytic bacteria possess the potential to demonstrate multiple PGP traits both, in vivo and in vitro and have the potential for further large‐scale trials. Significance and Impact of the Study: The exploration of tea endophytic bacterial community is suitable for the development of bioformulations for an integrated nutrient management and thus sustainable crop production and decreasing the hazardous effects of chemical fertilizers on the environment and human health. [ABSTRACT FROM AUTHOR]

The purpose of this study was to explore the microbial potential of a semi-arid sandy soil from south-central Algeria in order to isolate new chitinolytic actinobacteria. This soil is subjected to high temperatures (up to 43 °C) and has low nutrient content. Strains were isolated by plating soil suspensions on Bennett and Colloidal Chitin (CCM) medium. An initial clustering of isolates was made through BOX-PCR genetic profiling. Next, a 16S rRNA gene sequencing of representative isolates was realized. We also identified optimum physicochemical conditions for chitinolytic activity. A rapid in vitro assay based on glucose catabolic repression was developed to select isolates having a chitinase-dependent antifungal activity against two phytopathogenic fungi. Gene identification of glycosyl hydrolase family 18 (GH18) permitted us to assess the divergence of chitinase genes. Forty isolates were obtained from the semi-arid sandy soil. The molecular identification permitted us to assign them to Streptomyces or Micromonospora genera with seven possibly new bacterial species. For chitinolytic activity, 100% of isolates were able to grow and degrade colloidal chitin at pH 7 and at a temperature ranging from 30 to 40 °C. We also observed that Micromonospora strains had atypical activity patterns, with a strong chitinase activity maintained at high temperature. Finally, three strains presented an interesting chitinolytic potential to reduce fungal growth with new GH18 sequences. This study presents a new rapid method to detect antifungal chitinase-dependent activity that allowed to identify potentially new species of actinobacteria and new GH18 gene sequences. [ABSTRACT FROM AUTHOR]

The genus Pseudomonas includes pathogenic species P. syringae, which can be found in various agricultural environments and which can affect a wide variety of plants, causing significant economic losses when the environmental conditions for its proliferation are optimal. Comprehensive characterizations of phytopathogenic bacteria belonging to the genus Pseudomonas are scarce in Argentina. In this work, the tabtoxin‐producing strain Pseudomonas S5, isolated from oat, was identified as a P. syringae through biochemical tests such as the LOPAT test, and genetic tests such as the analysis of the small subunit ribosomal RNA gene (16S rRNA) sequence and repetitive elements, using BOX and ERIC primers. It was also determined that this phytopathogen is potentially capable of infecting other crops of agricultural importance for our region, such as soybean. This ability to infect different hosts gives it an adaptive advantage that allows it to endure seasonal changes in the environment where it lives. Our work contributes to the physiological classification of the phytopathogen P. syringae S5 isolated from our region, as well as to the knowledge about its range of potential hosts. [ABSTRACT FROM AUTHOR]

The deep bark canker of the walnut is a serious threat to walnut plants that had an increasing verge since recent years. This disease is caused by Brenneria rubrifaciens bacteria. Therefore, this research was carried out with an aim to identify the deep bark canker agent. The suspected samples having symptoms were collected from the bark and branches of walnut trees. After purification, the phenotypic and biochemical specification of separations was assessed. Even the genetic diversity of pathogen population was conducted with BOX-polymerase chains reaction (PCR) technique and BOXAIR primer. Based on the phenotypic and biochemical specifications, 30 isolates were identified as B. rubrifaciens. In PCR reaction, the specific amplicons of size 537 and 671 bp in the case study strains were amplified via specific primer pairs. The present study is a prime report on outbreak of this disease in Iran and bacterial pathogenicity evidence of B. rubrifaciens on fruit in the world.

Soils from the National Forest of Tapajos are nutrient-poor, acidic, podzolic clay types, with high aluminum content. The Dry Forest Project was developed to assess the impact of drought on a tropical forest. This project includes plots of Primary Forest (FP, control) and Dry Forest (FS, with exclusion of rain). This study assessed the effect of dryness on the microbial populations of soils collected in these plots. Twelve soil samples were analyzed for counts of total bacteria, fungi, and cellulolytic, proteolytic and phosphate solubilizer populations. A decrease of microbial counts was detected at the dry forest plot in comparison with the control, being more significant (two orders of magnitude) for cellulolytic populations. The majority of 286 isolated cultures were Gram-positive bacilli (47% for FP and 62% for FS) and the prevalent genera were Bacillus, Corynebacterium, Listeria and Micrococcuss. Box-PCR profiles of the bacteria from both plots showed high genetic diversity. The exclusion BATISTA, Selma Baia Centro de Ciências Biológicas e da Saúde (CCBS) Universidade Federal do Mato Grosso. Av. Fernando Correia da Costa. Bairro Boa Esperança, Cuiabá-MT. CEP 78060-900. Brasil. Tel. (65) 63615-8970. E-mail: selbbat@yahoo.com.br HARGREAVES, Paulo Iiboshi; MENDONÇA-HAGLER, Leda Cristina Instituto de Microbiologia Prof. Paulo de Góes (IMPPG) UFRJ; Laboratório de Ecologia Microbiana e Taxonomia; Centro de Ciências da Saúde (CCS), Bloco I, sala 44, Ilha do Fundão-RJ. CEP 21941-590. Brasil. Tel. (21) 2562-6739. SOUSA, Oscarina Viana de Instituto de Ciências do Mar – LABOMAR UFC; Av. da Abolição, 3207 – Meireles – Fortaleza-CE. CEP 60165-081. Tel. (85) 3366-7000 of rain can produce a negative effect on the microbial populations of tropical forest soil. The diversity, at the genus level, does not appear to be affected by drought, and the high diversity found for bacteria at the species/ subspecies level at both sites suggested a resilience of the soil microbiota to this environmental stress.

Os sedimentos apresentam-se como um sistema complexo, que são afetados por parâmetros geológicos, hidrodinâmicos, químicos e biológicos, caracterizado por uma interação entre o ambiente sedimentar de cada região. O presente estudo consistiu em caracterizar a diversidade de bactérias heterotróficas totais e fixadores de nitrogênio em sedimentos do rio Cuiabá utilizando técnicas convencionais de microbiologia e de biologia molecular. As amostras de sedimento foram coletadas com periodicidade bimestral, em quatro pontos sendo estes: Cuiabazinho, Passagem da Conceição, Ribeirão dos Cocais e Barão de Melgaço. As amostras foram processadas através de diluições seriadas (10-2 a 10-7 ) em solução salina 0,85%. Em seguida cultivadas em placa de Petri através da técnica de Spreed Plate, em meio de cultivo Trypic Soy Agar (TSA) para bactérias heterotróficas totais e para bactérias nitrificantes foram utilizados meios seletivos (NFB, JMV e Meio 79) incubadas a 35°C. Posteriormente as estirpes bacterianas foram reisoladas em Agar Nutriente (AN) a fim de obter cultura pura para análise morfotintorial de Gram. Este teste permitiu verificar que dos 202 isolados bacterianos, 59% eram bastonetes positivos, sendo que, a maior quantificação bacteriana obtida foi no meio de cultivo TSA, comparado aos outros meios de cultura. O perfil da comunidade bacteriana apresentou na sua maioria bactérias da família Bacillaceae com 28%, sendo que as mesmas foram utilizadas para a análise molecular por Box-PCR, que apresentou uma riqueza de espécies. Esses resultados indicam a importância de pesquisas sobre diversidade microbiana de sedimentos no Estado de Mato Grosso que utilizam técnicas moleculares.

Background: Macrolide resistance in Streptococcus pneumoniae (S. pneumoniae) is a worldwide problem. Aims: The aim of this work was to analyze the phenotypes, genotypes, and clonal relatedness among macrolide-resistant S. pneumoniae strains isolated from various clinical specimens in our hospital. Study Design: Cross-sectional study. Methods: 80 non-duplicate S. pneumoniae strains were analyzed by polymerase chain reaction for both the erm (B) and mef (A) genes. Results: Macrolide resistance was observed in 22.5% (18 strains) of strains. Two (11.2%) isolates possessed mef (A), eight possessed erm (B) (44.4%) and eight strains (44.4%) were positive for both erm (B) and mef (A) genes. Although BOX-PCR of 18 macrolide-resistant strains revealed 11 band patterns, they clustered as seven clones with a genetic distance >10% to each other. Eight isolates possessed both erm (B) and mef (A) genes and belonged to a single clone (44.44% of all macrolide-resistant strains). Conclusion: Increased positivity rates for both resistance genes have also been reported from other hospitals in Turkey, but this is the first study from Turkey showing the clonal dissemination of both resistance genes.

This study was conducted to evaluate the fermentative profile and microbial populations of wilted and non-wilted alfalfa silages ensiled with or without inoculant and the population dynamics of lactic acid bacteria (LAB) of wilted alfalfa plant and theirs silage. A 2 × 2 × 6 factorial arrangement was used, with the absence or presence of wilting (W), with and without bacterial inoculant (I) and six fermentation periods (P) (1, 3, 7, 14, 28 and 56 days), in a completely randomized design, with three replicates. The alfalfa was slightly wilted for 6 h and increased the dry matter content from 133.9 to 233.4 g/kg. It was performed the cultivation, followed by the isolation of LAB from samples of alfalfa forage before ensiling and its silage only in non-inoculated silages, after different fermentation periods. DNA was extracted from the isolated strains of LAB; the 16S rRNA gene sequences were amplified by PCR and the sequences were compared to those available from the GenBank database. Wilting provided silages with lower pH, ammonia nitrogen and acetic acid concentrations. The wilting process did not alter the amount of LAB; however, it affected the LAB diversity of the silages. The Lactobacillus plantarum was the predominant species in non-wilted and wilted silages. [ABSTRACT FROM AUTHOR]

Abstract In this study, isolation, conventional and molecular characterizations of ten thermophilic bacteria from Rize/Ayder were carried out. Xylanase from Geobacillus galactosidasius BS61 (GenBank number: KX447660) was purified by acetone precipitation, Diethylaminoethyl-cellulose and Sephadex G-100 chromatographies. The xylanase of G. galactosidasius BS61 in clarifying fruit juice was also investigated. Enzyme was purified 29.80-fold with 75.18% yield; and molecular weight was determined as 78.15 kDa. The optimum temperature of xylanase was 60 °C. The enzyme activity was maintained fully after 24 h and over 50% after 168 h at pH 4.0–10.0, while optimum pH was 7.0. K m and V max for beech wood xylan were measured as 3.18 mg mL−1, 123 U mg protein−1. In addition, Ca2+, Na+, Al3+, Zn2+, Cd2+, Mg2+, Ni2+, Cu2+ had decreasing effect on enzyme activity, while enzyme activity had been protected against anions, especially HSO3− and HPO 4 2− stimulated enzyme activity. Xylanase applications (with 15 U/mL enzyme activity) in orange and pomegranate juices were increased; and the sugar and turbidity amounts were reduced 17.36% ± 1.18 and 30.52 ± 1.23, respectively. These results indicated that the xylanase of G. galactosidasius BS61 has biotechnological potential in juice clarification due to its stability against metal ions, chemicals and high pH-values. Highlights • Ten bacteria from Rize/Ayder with tolerance to temperature, pH and salt concentrations were isolated and identified. • Each of ten thermophilic strain have abilities to produce different extracellular and industrially important enzymes. • Among the thermophilic isolates, Geobacillus galactosidasius BS61 was chosen due to high xylanase production capability. • Xylanase of G. galactosidasius BS61 was purified in higher yield, it was stable to agents and high pH and thermal values. [ABSTRACT FROM AUTHOR]

Innovative procedures were used to selectively isolate small numbers of Micromonospora strains from extreme hyper-arid and high altitude Atacama Desert soils. Micromonosporae were recognised on isolation plates by their ability to produce filamentous microcolonies that were strongly attached to the agar. Most of the isolates formed characteristic orange colonies that lacked aerial hyphae and turned black on spore formation, whereas those from the high altitude soil were dry, blue-green and covered by white aerial hyphae. The isolates were assigned to seven multi- and eleven single-membered groups based on BOX-PCR profiles. Representatives of the groups were assigned to either multi-membered clades that also contained marker strains or formed distinct phyletic lines in the Micromonospora 16S rRNA gene tree; many of the isolates were considered to be putatively novel species of Micromonospora. Most of the isolates from the high altitude soils showed activity against wild type strains of Bacillus subtilis and Pseudomonas fluorescens while those from the rhizosphere of Parastrephia quadrangulares and from the Lomas Bayas hyper-arid soil showed resistance to UV radiation. [ABSTRACT FROM AUTHOR]

Easy-to-perform, fast, and inexpensive methods of differentiation of Escherichia coli strains beyond the species level are highly required. Herein two new, original tools for genotyping of E. coli isolates are proposed. The first of the developed method, a PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) test uses a highly variable fliC gene, encoding the H antigen as a molecular target. The designing of universal pair of primers and selection of the optimal restriction enzyme RsaI was preceded by in silico comparative analysis of the sequences of the genes coding for 53 different serotypes of H-antigen (E. coli flagellin). The target fragments of E. coli genomes for MLST method were selected on the basis of bioinformatics analysis of complete sequences of 16 genomes of E. coli. Initially, seven molecular targets were proposed (seven pairs of primers) and five of them were found useful for effective genotyping of E. coli strains. Both developed methods revealed high differentiation power, and a high genetic diversity of the strains tested was observed. Within the group of 71 strains tested, 29 and 47 clusters were revealed with fliC RFLP-PCR and MLST methods, respectively. Differentiation of the strains with the reference BOX-PCR method revealed 31 different genotypes. The in silico analysis revealed that the discriminatory power of the new MLST method is comparable to the Pasteur and Achtman schemes and is higher than the discriminatory power of the method developed by Clermont. From the epidemiology point of view, the outcomes of our investigation revealed that in most cases, the patients were infected with unique strains, probably from environmental sources. However, some strains isolated from different patients of the wards of pediatrics, internal medicine, and neurology were classified to the same genotype when the results of all three methods were taken into account. It could suggest that they were transferred between the patients.

Cowpea derives most of its N nutrition from biological nitrogen fixation (BNF) via symbiotic bacteroids in root nodules. In Sub-Saharan Africa, the diversity and biogeographic distribution of bacterial microsymbionts nodulating cowpea and other indigenous legumes are not well understood, though needed for increased legume production. The aim of this study was to describe the distribution and phylogenies of rhizobia at different agroecological regions of Mozambique using PCR of the BOX element (BOX-PCR), restriction fragment length polymorphism of the internal transcribed spacer (ITS-RFLP), and sequence analysis of ribosomal, symbiotic, and housekeeping genes. A total of 122 microsymbionts isolated from two cowpea varieties (IT-1263 and IT-18) grouped into 17 clades within the BOX-PCR dendrogram. The PCR-ITS analysis yielded 17 ITS types for the bacterial isolates, while ITS-RFLP analysis placed all test isolates in six distinct clusters (I to VI). BLASTn sequence analysis of 16S rRNA and four housekeeping genes (glnII, gyrB, recA, and rpoB) showed their alignment with Rhizobium and Bradyrhizobium species. The results revealed a group of highly diverse and adapted cowpea-nodulating microsymbionts which included Bradyrhizobium pachyrhizi, Bradyrhizobium arachidis, Bradyrhizobium yuanmingense, and a novel Bradyrhizobium sp., as well as Rhizobium tropici, Rhizobium pusense, and Neorhizobium galegae in Mozambican soils. Discordances observed in single-gene phylogenies could be attributed to horizontal gene transfer and/or subsequent recombinations of the genes. Natural deletion of 60 bp of the gyrB region was observed in isolate TUTVU7; however, this deletion effect on DNA gyrase function still needs to be confirmed. The inconsistency of nifH with core gene phylogenies suggested differences in the evolutionary history of both chromosomal and symbiotic genes. [ABSTRACT FROM AUTHOR]

The genetic characteristics among Escherichia coli strains can be grouped by origin of isolation. Then, it is possible to use the genotypes as a tool to determine the source of water contamination. The aim of this study was to define water aptitude for human consumption in a rural basin and to assess the diversity of E. coli water populations. Thus, it was possible to identify the main sources of fecal contamination and to explore linkages with the hydrogeological environment and land uses. The bacteriological analysis showed that more than 50% of samples were unfit for human consumption. DNA fingerprinting analysis by BOX-PCR indicated low genotypic diversity of E. coli isolates taken from surface water and groundwater. The results suggested the presence of a dominant source of fecal contamination. The relationship between low genotypic diversity and land use would prove that water contamination comes from livestock. The genetic diversity of E. coli isolated from surface water was less than that identified in groundwater because of the different hydraulic features of both environments. Furthermore, each one of the two big strain groups identified in this basin is located in different sub-basins, showing that hydrological dynamics exerts selective pressure on bacteria DNA. [ABSTRACT FROM AUTHOR]

Soybean inoculation with effective rhizobial strains makes unnecessary the use of N-fertilizers in the tropics. A frequently reported problem is the failure of the inoculant strains to overcome the competition imposed by indigenous rhizobial populations. The screening of indigenous rhizobia, already adapted to local conditions, searching for highly effective strains for use as inoculants represents a promising strategy in overcoming inoculation failure. The objective of this study was to isolate and characterize indigenous rhizobia and to identify strains that hold potential to be included in inoculant formulations for soybean production, with both promiscuous and non-promiscuous soybean cultivars, in Mozambican agro-climatic conditions. A total of 105 isolates obtained from nodules of promiscuous soybean grown at 15 sites were screened for N 2 -fixation effectiveness in the greenhouse along with five commercial strains. Eighty-seven isolates confirmed the ability to form effective nodules on soybean and were used for genetic characterization by rep-PCR (BOX) and sequencing of the 16S rRNA gene, and also for symbiotic effectiveness. BOX-PCR fingerprinting revealed remarkable genetic diversity, with 41 clusters formed, considering a similarity level of 65%. The 16S rRNA analysis assigned the isolates to the genera Bradyrhizobium (75%) and Agrobacterium/Rhizobium (25%). Great variability in symbiotic effectiveness was detected among the indigenous rhizobia from Mozambique, with ten isolates performing better than the commercial strain B. diazoefficiens USDA 110, the best reference strain, and 51 isolates with lower performance than all reference strains. Thirteen of the best isolates from the first greenhouse trial were evaluated, along with the five commercial strains, in two promiscuous (TGx 1963-3F and TGx 1835-10E) and one non-promiscuous (BRS 284) soybean cultivars in a second greenhouse trial. In general the promiscous soybeans responded better to inoculation. The 13 isolates were also characterized for tolerance to acidity and alkalinity (pH 3.5 and 9.0, respectively), salinity (0.1, 0.3 and 0.5 mol L −1 of NaCl) and high temperatures (35, 40 and 45 °C) in vitro . Five isolates, three (Moz 4, Moz 19 and Moz 22) belonging to the superclade B. elkanii and two (Moz 27 and Moz 61) assigned to the superclade B. japonicum, consistently showed high symbiotic effectiveness, suggesting that the inoculation with indigenous rhizobia adapted to local conditions represents a possible strategy for increasing soybean yields in Mozambique. Phylogenetic position of the five elite isolates was confirmed by the MLSA with four protein-coding housekeeping genes, dnaK , glnII , gyrB and recA. [ABSTRACT FROM AUTHOR]

The deep bark canker of the walnut is a serious threat to walnut plants that had an increasing verge since recent years. This disease is caused byBrenneria rubrifaciensbacteria. Therefore, this research was carried out with an aim to identify the deep bark canker agent. The suspected samples having symptoms were collected from the bark and branches of walnut trees. After purification, the phenotypic and biochemical specification of separations was assessed. Even the genetic diversity of pathogen population was conducted with BOX-polymerase chains reaction (PCR) technique and BOXAIR primer. Based on the phenotypic and biochemical specifications, 30 isolates were identified asB. rubrifaciens. In PCR reaction, the specific amplicons of size 537 and 671 bp in the case study strains were amplified via specific primer pairs. The present study is a prime report on outbreak of this disease in Iran and bacterial pathogenicity evidence ofB. rubrifacienson fruit in the world. [ABSTRACT FROM PUBLISHER]

Copyright of Kafkas Universitesi Veteriner Fakultesi Dergisi is the property of University of Kafkas, Faculty of Veterinary Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

بیماری شانکر باکتریایی هسته¬داران با عامل (Pss) Pseudomonas syringae pv. syringae یکی از بیماری‌های شایع درختان میوه هسته¬دار در استان¬های شمالی و مرکزی ایران می¬باشد. به منظور شناسایی جدایه‌های عامل بیماری، طی سال¬های 1390-1389، 105 جدایه به ‌دست آمده از باغ‌های درختان میوه هسته¬دار واقع در مناطق مختلف استان¬های اردبیل، آذربایجان ‌شرقی، گیلان، مازندران، خراسان ‌رضوی، تهران و قزوین از نظر فنوتیپی، بیماری¬زایی و الکتروفورز پروتئین¬های سلولی و وجود ژن سرینگومایسین (syrB) مورد بررسی قرار گرفتند. جدایه¬ها از نظر ویژگی¬های فنوتیپی و الگوی پروتئین¬های سلولی اختلاف¬های جزئی نشان دادند. همه جدایه¬ها روی هلو دارای قدرت بیماری¬زایی بالایی بودند و از این نظر مشابه به نظر رسیدند. همه¬ی جدایه‌ها به همراه جدایه¬ی استاندارد، قطعه¬ی 752 جفت بازی با آغازگر syrB را تکثیر کردند. تنوع ژنتیکی بین جدایه¬ها با دو روش BOX-PCR و IS50-PCR بررسی شد. آنالیز خوشه‌ای نتایج به دست آمده نشان داد که در BOX-PCR در سطح تشابه 73 درصد، جدایه¬ها به 9 گروه و با IS50-PCR به 8 گروه و با ترکیب همه آغازگرها به 11 گروه تقسیم شدند. بین تنوع ژنتیکی جدایه‌ها و منشأ جغرافیایی آنها ارتباط معنی داری وجود نداشت. نتایج نشانگر وجود تنوع ژنتیکی بالا درون جدایه¬های مختلف Pss عامل بیماری شانکر باکتریایی درختان میوه هسته¬دار بود. در این بررسی ارتباط مشخصی بین منشأ جغرافیایی جدایه¬ها و گروه¬های حاصل از بررسی تنوع ژنتیکی آنها مشاهده نشد

Antimicrobial resistance poses a serious challenge to global public health. In this study, fifty bacterial strains were isolated from the sediments of a freshwater lake and were screened for antibiotic resistance. Out of fifty isolates, thirty-three isolates showed resistance against at least two of the selected antibiotics. Analysis of 16S rDNA sequencing revealed that the isolates belonged to ten different genera, namely Staphylococcus(n = 8), Bacillus(n = 7), Lysinibacillus(n = 4), Achromobacter(n=3), bacterium(n = 3), Methylobacterium(n = 2), Bosea(n = 2), Aneurinibacillus(n = 2), Azospirillum(n = 1), Novosphingobium(n = 1). Enterobacterial repetitive intergenic consensus (ERIC) and BOX-PCR markers were used to study the genetic relatedness among the antibiotic resistant isolates. Further, the isolates were screened for their antimicrobial activity against bacterial pathogens viz., Staphylococcus aureus(MTCC-96), Pseudomonas aeruginosa(MTCC-2453) and Escherichia coli(MTCC-739), and pathogenic fungi viz., Fusarium proliferatum (MTCC-286), Fusarium oxysporum (CABI-293942) and Fusarium oxy. ciceri (MTCC-2791). In addition, biosynthetic genes (polyketide synthase II (PKS-II) and non-ribosomal peptide synthetase (NRPS)) were detected in six and seven isolates, respectively. This is the first report for the multifunctional analysis of the bacterial isolates from a wetland with biosynthetic potential, which could serve as potential source of useful biologically active metabolites.

In this study, the BOX-PCR fingerprinting technique was evaluated for the discrimination of clinical Pseudomonas aeruginosa isolates. All isolates were typeable and nearly half showed unique banding patterns. According to our results, BOX-PCR fingerprinting is applicable for typing of Pseudomonas aeruginosa isolates and can be considered a useful complementary tool for epidemiological studies of members of this genus. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 4, pp. 734–738)

Data about symptomatology, pathogenicity and bacteriological characteristics of Pseudomonas syringae, and PCR methods for fast and reliable detection of the pathogen are given in this paper. P. syringae has been experimentaly proved as a pathogen of pear, apple, apricot, plum cherry, and raspberry, and pathogen strains have also been isolated from necrotic peach buds. Two pathogen varieties, syringae and morsprunorum, were found in our research in Serbia, the former being dominant on fruit trees.The most reliable method for detection of this bacteria is PCR, using BOX and REP primers. This method has also revealed significant differences among the strains originating from fruit trees in Serbia. Thus, it was proved that the population of P. syringae in Serbia is heterogeneous, which is very important for future epidemiologocal studies. Control of this pathogen includes mechanical, cultural and chemical measures, but integrated approach is very important for sustainable control.

Pseudomonas syringae is a widespread and economically important plant pathogen, one found on a number of hosts, including fruit trees, field crops, vegetables, and ornamental plants. This bacterium has been experimentally identified as a parasite of pear, apple, apricot, peach, cherry, sour cherry, plum, and raspberry. The present study was designed to establish differences between strains isolated from fruit trees in Serbia. The pathogenic and biochemical characteristics of isolates were studied. The BOX-PCR method was used to generate genomic fingerprints of Pseudomonas syringae isolates and to identify strains that were previously not distinguishable by other classification methods. Different Bacillus sp. strains were tested for in vitro inhibitory activity against Pseudononas syringae isolates. Bacillus sp. strains show inhibitory activity only against P. syringae isolates that originated from peach. The obtained results demonstrate that the population of the bacterium Pseudomonas syringae from the fruit trees in Serbia is very diverse.

The phenotypic characteristics and genetic fingerprints of a collection of 120 bacterial strains, belonging to Pseudomonas syringae sensu lato group, P. viridiflava and reference bacteria were evaluated, with the aim of species identification. The numerical analysis of 119 nutritional characteristics did not show patterns that would help with identification. Regarding the genetic fingerprinting, the results of the present study supported the observation that BOX-PCR seems to be able to identify bacterial strains at species level. After numerical analyses of the bar-codes, all pathovars belonging to each one of the nine described genomospecies were clustered together at a distance of 0.72, and could be separated at genomic species level. Two P. syringae strains of unknown pathovars (CFBP 3650 and CFBP 3662) and the three P. syringae pv. actinidiae strains were grouped in two extra clusters and might eventually constitute two new species. This genomic species clustering was particularly evident for genomospecies 4, which gathered P. syringae pvs. atropurpurea, coronafaciens, garçae, oryzae, porri, striafaciens, and zizaniae at a noticeably low distance.