Iodine from bacterial iodide oxidization by Roseovarius spp. inhibits the growth of other bacteria.

PubMed

Zhao, Dan; Lim, Choon-Ping; Miyanaga, Kazuhiko; Tanji, Yasunori

2013-03-01

Microbial activities in brine, seawater, or estuarine mud are involved in iodine cycle. To investigate the effects of the microbiologically induced iodine on other bacteria in the environment, a total of 13 bacteria that potentially participated in the iodide-oxidizing process were isolated from water or biofilm at a location containing 131 μg ml(-1) iodide. Three distinct strains were further identified as Roseovarius spp. based on 16 S rRNA gene sequences after being distinguished by restriction fragment length polymorphism analysis. Morphological characteristics of these three Roseovarius spp. varied considerably across and within strains. Iodine production increased with Roseovarius spp. growth when cultured in Marine Broth with 200 μg ml(-1) iodide (I(-)). When 10(6) CFU/ml Escherichia coli, Pseudomonas aeruginosa, and Bacillus pumilus were exposed to various concentrations of molecular iodine (I(2)), the minimum inhibitory concentrations (MICs) were 0.5, 1.0, and 1.0 μg ml(-1), respectively. However, fivefold increases in the MICs for Roseovarius spp. were obtained. In co-cultured Roseovarius sp. IOB-7 and E. coli in Marine Broth containing iodide (I(-)), the molecular iodine concentration was estimated to be 0.76 μg ml(-1) after 24 h and less than 50 % of E. coli was viable compared to that co-cultured without iodide. The growth inhibition of E. coli was also observed in co-cultures with the two other Roseovarius spp. strains when the molecular iodine concentration was assumed to be 0.52 μg ml(-1).

Contamination of salmon fillets and processing plants with spoilage bacteria.

PubMed

Møretrø, Trond; Moen, Birgitte; Heir, Even; Hansen, Anlaug Å; Langsrud, Solveig

2016-11-21

The processing environment of salmon processing plants represents a potential major source of bacteria causing spoilage of fresh salmon. In this study, we have identified major contamination routes of important spoilage associated species within the genera Pseudomonas, Shewanella and Photobacterium in pre-rigor processing of salmon. Bacterial counts and culture-independent 16S rRNA gene analysis on salmon fillet from seven processing plants showed higher levels of Pseudomonas spp. and Shewanella spp. in industrially processed fillets compared to salmon processed under strict hygienic conditions. Higher levels of Pseudomonas spp. and Shewanella spp. were found on fillets produced early on the production day compared to later processed fillets. The levels of Photobacterium spp. were not dependent on the processing method or time of processing. In follow-up studies of two plants, bacterial isolates (n=2101) from the in-plant processing environments (sanitized equipment/machines and seawater) and from salmon collected at different sites in the production were identified by partial 16S rRNA gene sequencing. Pseudomonas spp. dominated in equipment/machines after sanitation with 72 and 91% of samples from the two plants being Pseudomonas-positive. The phylogenetic analyses, based on partial 16S rRNA gene sequencing, showed 48 unique sequence profiles of Pseudomonas of which two were dominant. Only six profiles were found on both machines and in fillets in both plants. Shewanella spp. were found on machines after sanitation in the slaughter department while Photobacterium spp. were not detected after sanitation in any parts of the plants. Shewanella spp. and Photobacterium spp. were found on salmon in the slaughter departments. Shewanella was frequently present in seawater tanks used for bleeding/short term storage. In conclusion, this study provides new knowledge on the processing environment as a source of contamination of salmon fillets with Pseudomonas spp. and

Effect of Iron Availability on Induction of Systemic Resistance to Fusarium Wilt of Chickpea by Pseudomonas spp.

PubMed

Saikia, Ratul; Srivastava, Alok K; Singh, Kiran; Arora, Dilip K; Lee, Min-Woong

2005-03-01

Selected isolates of Pseudomonas fluorescens (Pf4-92 and PfRsC5) and P. aeruginosa (PaRsG18 and PaRsG27) were examined for growth promotion and induced systemic resistance against Fusarium wilt of chickpea. Significant increase in plant height was observed in Pseudomonas treated plants. However, plant growth was inhibited when isolates of Pseudomonas were used in combination with Fusarium oxysporum f. sp. ciceri (FocRs1). It was also observed that the Pseudomonas spp. was colonized in root of chickpea and significantly suppressed the disease in greenhouse condition. Rock wool bioassay technique was used to study the effect of iron availability on the induction of systemic resistance to Fusarium wilt of chickpea mediated by the Pseudomonas spp. All the isolates of Pseudomonas spp. showed greater disease control in the induced systemic resistance (ISR) bioassay when iron availability in the nutrient solution was low. High performance liquid chromatography (HPLC) analysis indicated that all the bacterial isolates produced more salicylic acid (SA) at low iron (10µM EDDHA) than high iron availability (10µFe(3+) EDDHA). Except PaRsG27, all the three isolates produced more pseudobactin at low iron than high iron availability.

Effect of Iron Availability on Induction of Systemic Resistance to Fusarium Wilt of Chickpea by Pseudomonas spp.

PubMed Central

Saikia, Ratul; Srivastava, Alok K.; Singh, Kiran; Lee, Min-Woong

2005-01-01

Selected isolates of Pseudomonas fluorescens (Pf4-92 and PfRsC5) and P. aeruginosa (PaRsG18 and PaRsG27) were examined for growth promotion and induced systemic resistance against Fusarium wilt of chickpea. Significant increase in plant height was observed in Pseudomonas treated plants. However, plant growth was inhibited when isolates of Pseudomonas were used in combination with Fusarium oxysporum f. sp. ciceri (FocRs1). It was also observed that the Pseudomonas spp. was colonized in root of chickpea and significantly suppressed the disease in greenhouse condition. Rock wool bioassay technique was used to study the effect of iron availability on the induction of systemic resistance to Fusarium wilt of chickpea mediated by the Pseudomonas spp. All the isolates of Pseudomonas spp. showed greater disease control in the induced systemic resistance (ISR) bioassay when iron availability in the nutrient solution was low. High performance liquid chromatography (HPLC) analysis indicated that all the bacterial isolates produced more salicylic acid (SA) at low iron (10µM EDDHA) than high iron availability (10µFe3+ EDDHA). Except PaRsG27, all the three isolates produced more pseudobactin at low iron than high iron availability. PMID:24049472

Lipolytic and proteolytic activity of Pseudomonas spp. isolated during milking and storage of refrigerated raw milk.

PubMed

Capodifoglio, Eduardo; Vidal, Ana Maria Centola; Lima, Joyce Aparecida Santos; Bortoletto, Fernanda; D'Abreu, Léa Furlan; Gonçalves, Ana Carolina Siqueira; Vaz, Andreia Cristina Nakashima; Balieiro, Julio Cesar de Carvalho; Netto, Arlindo Saran

2016-07-01

The aim of this study was to verify the presence of lipolytic and proteolytic Pseudomonas spp. during milking and storage of refrigerated raw milk. We also intended to compare samples collected during rainy and dry seasons, from farms with manual and mechanical milking systems. For this, samples of milkers' hands, cows' teats, water, expansion tanks, equipment, and utensils used during milking were analyzed regarding Pseudomonas spp. Positive samples were tested for the production of lipolytic and proteolytic enzymes. Microorganisms of the genus Pseudomonas were isolated from all sampling points. A higher isolation rate of the bacterium was found in the rainy season except for 6 sampling points, with all of these associated with mechanical milking systems. Pseudomonas spp. exhibiting lipolytic activity were found to be predominant during the dry season, since no activity was detected during the rainy season in 26 of the 29 sampling sites. The highest number of lipolytic Pseudomonas isolates was obtained from water. Presence of lipase-producing Pseudomonas spp. was verified in 7 and 36% of the samples collected from farms with manual and mechanical milking, respectively. When analyzing raw milk collected from expansion tanks immediately (0 h) and 24h after milking, we observed that for dairy properties with manual milking process, 10% of the Pseudomonas isolates were positive for lipolytic activity. The percentage increased to 12% 48h after milking. Mean averages were 32, 33, and 39% immediately after, 24 and 48h after milking, respectively, for farms with mechanical milking. All sampling points showed the presence of proteolytic strains of Pseudomonas. The highest proteolytic activity was found during the rainy season, except for the samples collected from milkers' hands before milking, buckets, and teat cup inner surfaces after milking and from the water in dairy farms with mechanical milking system. Of these samples, 72, 56, and 50%, respectively, were positive

Genomic Diversity of Biocontrol Strains of Pseudomonas spp. Isolated from Aerial or Root Surfaces of Plants

USDA-ARS?s Scientific Manuscript database

The striking ecological, metabolic, and biochemical diversity of Pseudomonas has intrigued microbiologists for many decades. To explore the genomic diversity of biocontrol strains of Pseudomonas spp., we derived high quality draft sequences of seven strains known to suppress plant disease. The str...

The role of gluconate production by Pseudomonas spp. in the mineralization and bioavailability of calcium-phytate to Nicotiana tabacum.

PubMed

Giles, Courtney D; Hsu, Pei-Chun Lisa; Richardson, Alan E; Hurst, Mark R H; Hill, Jane E

2015-12-01

Organic phosphorus (P) is abundant in most soils but is largely unavailable to plants. Pseudomonas spp. can improve the availability of P to plants through the production of phytases and organic anions. Gluconate is a major component of Pseudomonas organic anion production and may therefore play an important role in the mineralization of insoluble organic P forms such as calcium-phytate (CaIHP). Organic anion and phytase production was characterized in 2 Pseudomonas spp. soil isolates (CCAR59, Ha200) and an isogenic mutant of strain Ha200, which lacked a functional glucose dehydrogenase (Gcd) gene (strain Ha200 gcd::Tn5B8). Wild-type and mutant strains of Pseudomonas spp. were evaluated for their ability to solubilize and hydrolyze CaIHP and to promote the growth and assimilation of P by tobacco plants. Gluconate, 2-keto-gluconate, pyruvate, ascorbate, acetate, and formate were detected in Pseudomonas spp. supernatants. Wild-type pseudomonads containing a functional gcd could produce gluconate and mineralize CaIHP, whereas the isogenic mutant could not. Inoculation with Pseudomonas improved the bioavailability of CaIHP to tobacco plants, but there was no difference in plant growth response due to Gcd function. Gcd function is required for the mineralization of CaIHP in vitro; however, further studies will be needed to quantify the relative contribution of specific organic anions such as gluconate to plant growth promotion by soil pseudomonads.

Phosphatase activity of aerobic and facultative anaerobic bacteria.

PubMed

Pácová, Z; Kocur, M

1978-10-01

1115 strains of aerobic and facultatively anaerobic bacteria were tested for phosphatase activity by a conventional plate method and a microtest. The microtest was devised to allow results to be read after 4 h cultivation. Phosphatase activity was found in wide range of species and strains. Besides staphylococci, where the test for phosphatase is successfully used, it may be applied as one of the valuable tests for the differentiation of the following species: Bacillus cereus, B. licheniformis, Aeromonas spp., Vibrio parahaemolyticus, Actinobacillus spp., Pasteurella spp., Xanthomonas spp., Flavobacterium spp., Alteromonas putrefaciens, Pseudomonas maltophilia, Ps. cepacia, and some other species of Pseudomonas. The species which gave uniformly negative phosphatase reaction were as follows: Staph. saprophyticus, Acinetobacter calcoaceticus, Alcaligenes faecalis, and Bordetella bronchiseptica.

Evaluation of Double-Disk Potentiation and Disk Potentiation Tests Using Dipicolinic Acid for Detection of Metallo-β-Lactamase-Producing Pseudomonas spp. and Acinetobacter spp.

PubMed Central

Yong, Dongeun; Lee, Yangsoon; Jeong, Seok Hoon; Lee, Kyungwon

2012-01-01

Accurate detection of metallo-β-lactamase (MBL)-producing Pseudomonas spp. and Acinetobacter spp. became very important with the increasing prevalence of carbapenem-nonsusceptible clinical isolates. The performance of phenotypic MBL detection methods may depend on the types of MBL and the characteristics of the isolates. A high false-positive rate is a problem with EDTA-based MBL detection methods. We evaluated the performance of double-disk potentiation tests (DDPTs) and disk potentiation tests (DPTs) with dipicolinic acid (DPA) using 44 isolates of Pseudomonas spp. and Acinetobacter spp. producing IMP-1-like, VIM-2-like, and SIM-1 type MBLs. Also, we characterized P. aeruginosa isolates with positive imipenem (IPM)-DPA DDPT, but negative meropenem (MEM)-DPA DDPT, and determined possibility of improving a DDPT by using MacConkey agar. Among five different DDPT methods, the IPM-DPA 250-μg method showed the highest sensitivity (97.7%) and specificity (100%). Among four DPT tests, the highest sensitivity (100%) was shown by the IPM-EDTA 1,900-μg disk method, but the specificity was very low (11.4%). Five of six P. aeruginosa isolates with false-negative DDPTs with MEM-DPA 250-μg disks carried blaIMP-6, and the high level resistance to MEM (MIC ≥ 512 μg/ml) was reduced by the presence of phenylalanine arginine β-naphtylamide. Improvement of DDPTs was observed when MacConkey agar was used instead of Mueller-Hinton agar. In conclusion, DPA is a better MBL inhibitor than EDTA for detection of Pseudomonas spp. and Acinetobacter spp. with IMP-1-like, VIM-2-like, and SIM-1-type MBLs. In DPA DDPTs, IPM disks perform better than MEM disks when the isolates are highly resistant to MEM due to the overexpression of efflux pumps. PMID:22837321

Computational prediction of the Crc regulon identifies genus-wide and species-specific targets of catabolite repression control in Pseudomonas bacteria.

PubMed

Browne, Patrick; Barret, Matthieu; O'Gara, Fergal; Morrissey, John P

2010-11-25

Catabolite repression control (CRC) is an important global control system in Pseudomonas that fine tunes metabolism in order optimise growth and metabolism in a range of different environments. The mechanism of CRC in Pseudomonas spp. centres on the binding of a protein, Crc, to an A-rich motif on the 5' end of an mRNA resulting in translational down-regulation of target genes. Despite the identification of several Crc targets in Pseudomonas spp. the Crc regulon has remained largely unexplored. In order to predict direct targets of Crc, we used a bioinformatics approach based on detection of A-rich motifs near the initiation of translation of all protein-encoding genes in twelve fully sequenced Pseudomonas genomes. As expected, our data predict that genes related to the utilisation of less preferred nutrients, such as some carbohydrates, nitrogen sources and aromatic carbon compounds are targets of Crc. A general trend in this analysis is that the regulation of transporters is conserved across species whereas regulation of specific enzymatic steps or transcriptional activators are often conserved only within a species. Interestingly, some nucleoid associated proteins (NAPs) such as HU and IHF are predicted to be regulated by Crc. This finding indicates a possible role of Crc in indirect control over a subset of genes that depend on the DNA bending properties of NAPs for expression or repression. Finally, some virulence traits such as alginate and rhamnolipid production also appear to be regulated by Crc, which links nutritional status cues with the regulation of virulence traits. Catabolite repression control regulates a broad spectrum of genes in Pseudomonas. Some targets are genus-wide and are typically related to central metabolism, whereas other targets are species-specific, or even unique to particular strains. Further study of these novel targets will enhance our understanding of how Pseudomonas bacteria integrate nutritional status cues with the regulation

Mycoplasma and associated bacteria isolated from ovine pink-eye.

PubMed

Langford, E V

1971-01-01

A mycoplasma was recovered from the untreated conjunctival membranes of nine sheep affected by Pink-eye. It was neither isolated from the conjunctiva of treated animals which were affected nor from the conjunctiva of normal animals either in contact or not in contact with affected animals. Bacteria found on normal conjunctival membranes were Neisseria ovis, Escherichia coli, Staphylococcus epidermididis, Streptococcus and Bacillus spp. Bacteria found in clinical cases of Pink-eye were N. ovis, E. coli, a Streptococcus and Pseudomonas spp.

A novel GoldNano Carb test for rapid phenotypic detection of carbapenemases, particularly OXA type, in Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter spp.

PubMed

Srisrattakarn, Arpasiri; Lulitanond, Aroonlug; Wilailuckana, Chotechana; Charoensri, Nicha; Daduang, Jureerut; Chanawong, Aroonwadee

2017-09-01

To develop a simple gold nanoparticle (AuNP)-based colorimetric test, GoldNano Carb (GoldC), for detecting carbapenemase production in Gram-negative bacteria, compared with updated Carba NP (CNP) and CarbAcineto NP (CAcNP) tests by using PCR methods as gold standard. Ninety-nine carbapenemase-producing Enterobacteriaceae (CPE), Pseudomonas spp. and Acinetobacter spp. isolates and 89 non-CPE isolates were tested by the GoldC and CNP. Additionally, the CAcNP was performed in the Acinetobacter spp. isolates. The final imipenem (imipenem/cilastatin form) concentration was 5 mg/mL for all three tests. For the GoldC, the imipenem powder was added directly to bacterial cell suspension in distilled water prior to detection of acid product by the citrate-capped AuNP solution. An AuNP change from red to purple, blue or green indicates carbapenemase activity. The GoldC detected all carbapenemase producers except one OXA-23-like producer (99.0% sensitivity), whereas 11 carbapenemase producers (10 Acinetobacter and 1 P. aeruginosa) were CNP negative (88.9% sensitivity). However, the GoldC and CNP provided 100% and 98.6% sensitivity, respectively, for the CPE and Pseudomonas spp. Both tests gave one false positive from CTX-M-1-like-producing Enterobacter spp. (98.9% specificity). The GoldC and CAcNP detected 96.7% and 93.3% of the Acinetobacter spp. isolates, respectively. Interestingly, times to positivity by the GoldC were markedly shorter than those by the CNP (76.8% versus 36.2% positive at 5 min) and CAcNP (43.3% at 5 min versus 20% within 30 min). The GoldC is fast, easy, highly sensitive and inexpensive (∼$0.25 per test), suggesting that it may be suitable for routine carbapenemase detection in low-resource settings for infection control or epidemiological purposes. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Marine Pseudomonas putida: a potential source of antimicrobial substances against antibiotic-resistant bacteria.

PubMed

Marinho, Palloma Rodrigues; Moreira, Ana Paula Barbosa; Pellegrino, Flávia Lúcia Piffano Costa; Muricy, Guilherme; Bastos, Maria do Carmo de Freire; Santos, Kátia Regina Netto dos; Giambiagi-deMarval, Marcia; Laport, Marinella Silva

2009-08-01

Bacteria isolated from marine sponges found off the coast of Rio de Janeiro, Brazil, were screened for the production of antimicrobial substances. We report a new Pseudomonas putida strain (designated P. putida Mm3) isolated from the sponge Mycale microsigmatosa that produces a powerful antimicrobial substance active against multidrug-resistant bacteria. P. putida Mm3 was identified on the basis of 16S rRNA gene sequencing and phenotypic tests. Molecular typing for Mm3 was performed by RAPD-PCR and comparison of the results to other Pseudomonas strains. Our results contribute to the search for new antimicrobial agents, an important strategy for developing alternative therapies to treat infections caused by multidrug-resistant bacteria.

Irrigation differentially impacts populations of indigenous antibiotic-producing Pseudomonas spp. in the rhizosphere of wheat

USDA-ARS?s Scientific Manuscript database

This work determined the impact of irrigation on the seasonal dynamics of populations of Pseudomonas spp. producing the antibiotics phenazine-1-carboxylic acid (Phz+) and 2,4-diacetylphloroglucinol (Phl+) in the rhizosphere of wheat grown in the low precipitation zone (150 to 300 mm annually) of the...

Pseudomonas mesophilica and an unnamed taxon, clinical isolates of pink-pigmented oxidative bacteria.

PubMed

Gilardi, G L; Faur, Y C

1984-10-01

Twenty-one strains of pink-pigmented bacteria, isolated from human clinical specimens and an environmental source, were compared with Pseudomonas mesophilica ATCC 29983 and Protaminobacter ruber ATCC 8457. These isolates were gram-negative, oxidative rods which were motile by means of a single polar flagellum; gave positive catalase, indophenol oxidase, urease, and amylase reactions; and grew slowly at 30 degrees C. Fourteen isolates conformed to the designated type strains Pseudomonas mesophilica ATCC 29983 and Protaminobacter ruber ATCC 8457. The remaining seven strains represented an undescribed taxon. These pink bacteria appear to be invaders of debilitated patients with an underlying chronic disease.

Pseudomonas mesophilica and an unnamed taxon, clinical isolates of pink-pigmented oxidative bacteria.

PubMed Central

Gilardi, G L; Faur, Y C

1984-01-01

Twenty-one strains of pink-pigmented bacteria, isolated from human clinical specimens and an environmental source, were compared with Pseudomonas mesophilica ATCC 29983 and Protaminobacter ruber ATCC 8457. These isolates were gram-negative, oxidative rods which were motile by means of a single polar flagellum; gave positive catalase, indophenol oxidase, urease, and amylase reactions; and grew slowly at 30 degrees C. Fourteen isolates conformed to the designated type strains Pseudomonas mesophilica ATCC 29983 and Protaminobacter ruber ATCC 8457. The remaining seven strains represented an undescribed taxon. These pink bacteria appear to be invaders of debilitated patients with an underlying chronic disease. PMID:6490848

Recent Insights into the Diversity, Frequency and Ecological Roles of Phenazines in Fluorescent Pseudomonas spp.

USDA-ARS?s Scientific Manuscript database

Phenazine compounds represent a large class of bacterial metabolites that are produced by some fluorescent Pseudomonas spp. and a few other bacterial genera. Phenazines were first noted in the scientific literature over 100 years ago, but for a long time were considered to be pigments of uncertain f...

Toxicity of Pseudomonas fluorescens strain Pf-5 to Drosophila larvae is due to downstream gene targets of the GacA/GacS signal transduction system

USDA-ARS?s Scientific Manuscript database

Given the vast number of microorganisms in the environment, surprisingly, only a few are lethal or cause morbidity to host organisms. Pseudomonas spp are a diverse genus of Gram-negative bacteria commonly found in soil, water, or in association with plants and animals. Pseudomonas fluorescens has be...

Amniotic Fluid Protein Profiles of Intraamniotic Inflammatory Response to Ureaplasma spp. and Other Bacteria

PubMed Central

Kacerovsky, Marian; Celec, Peter; Vlkova, Barbora; Skogstrand, Kristin; Hougaard, David M.; Cobo, Teresa; Jacobsson, Bo

2013-01-01

Objective This study aimed to evaluate the amniotic fluid protein profiles and the intensity of intraamniotic inflammatory response to Ureaplasma spp. and other bacteria, using the multiplex xMAP technology. Methods A retrospective cohort study was undertaken in the Department of Obstetrics and Gynecology, University Hospital Hradec Kralove, Czech Republic. A total of 145 pregnant women with preterm prelabor rupture of membranes between gestational age 24+0 and 36+6 weeks were included in the study. Amniocenteses were performed. The presence of Ureaplasma spp. and other bacteria was evaluated using 16S rRNA gene sequencing. The levels of specific proteins were determined using multiplex xMAP technology. Results The presence of Ureaplasma spp. and other bacteria in the amniotic fluid was associated with increased levels of interleukin (IL)-6, IL-8, IL-10, brain-derived neurotropic factor, granulocyte macrophage colony stimulating factor, monocyte chemotactic protein-1, macrophage inflammatory protein-1, and matrix metalloproteinasis-9. Ureaplasma spp. were also associated with increased levels of neurotropin-3 and triggering receptor expressed on myeloid cells-1. Conclusions The presence of Ureaplasma spp. in the amniotic fluid is associated with a slightly different protein profile of inflammatory response, but the intensity of inflammatory response to Ureaplasma spp. is comparable with the inflammatory response to other bacteria. PMID:23555967

Amniotic fluid protein profiles of intraamniotic inflammatory response to Ureaplasma spp. and other bacteria.

PubMed

Kacerovsky, Marian; Celec, Peter; Vlkova, Barbora; Skogstrand, Kristin; Hougaard, David M; Cobo, Teresa; Jacobsson, Bo

2013-01-01

This study aimed to evaluate the amniotic fluid protein profiles and the intensity of intraamniotic inflammatory response to Ureaplasma spp. and other bacteria, using the multiplex xMAP technology. A retrospective cohort study was undertaken in the Department of Obstetrics and Gynecology, University Hospital Hradec Kralove, Czech Republic. A total of 145 pregnant women with preterm prelabor rupture of membranes between gestational age 24+0 and 36+6 weeks were included in the study. Amniocenteses were performed. The presence of Ureaplasma spp. and other bacteria was evaluated using 16S rRNA gene sequencing. The levels of specific proteins were determined using multiplex xMAP technology. The presence of Ureaplasma spp. and other bacteria in the amniotic fluid was associated with increased levels of interleukin (IL)-6, IL-8, IL-10, brain-derived neurotropic factor, granulocyte macrophage colony stimulating factor, monocyte chemotactic protein-1, macrophage inflammatory protein-1, and matrix metalloproteinasis-9. Ureaplasma spp. were also associated with increased levels of neurotropin-3 and triggering receptor expressed on myeloid cells-1. The presence of Ureaplasma spp. in the amniotic fluid is associated with a slightly different protein profile of inflammatory response, but the intensity of inflammatory response to Ureaplasma spp. is comparable with the inflammatory response to other bacteria.

Efficacy of lactoferricin B in controlling ready-to-eat vegetable spoilage caused by Pseudomonas spp.

PubMed

Federico, Baruzzi; Pinto, Loris; Quintieri, Laura; Carito, Antonia; Calabrese, Nicola; Caputo, Leonardo

2015-12-23

The microbial content of plant tissues has been reported to cause the spoilage of ca. 30% of chlorine-disinfected fresh vegetables during cold storage. The aim of this work was to evaluate the efficacy of antimicrobial peptides in controlling microbial vegetable spoilage under cold storage conditions. A total of 48 bacterial isolates were collected from ready-to-eat (RTE) vegetables and identified as belonging to Acinetobacter calcoaceticus, Aeromonas media, Pseudomonas cichorii, Pseudomonas fluorescens, Pseudomonas jessenii, Pseudomonas koreensis, Pseudomonas putida, Pseudomonas simiae and Pseudomonas viridiflava species. Reddish or brownish pigmentation was found when Pseudomonas strains were inoculated in wounds on leaves of Iceberg and Trocadero lettuce and escarole chicory throughout cold storage. Bovine lactoferrin (BLF) and its hydrolysates (LFHs) produced by pepsin, papain and rennin, were assayed in vitro against four Pseudomonas spp. strains selected for their heavy spoiling ability. As the pepsin-LFH showed the strongest antimicrobial effect, subsequent experiments were carried out using the peptide lactoferricin B (LfcinB), well known to be responsible for its antimicrobial activity. LfcinB significantly reduced (P ≤ 0.05) spoilage by a mean of 36% caused by three out of four inoculated spoiler pseudomonads on RTE lettuce leaves after six days of cold storage. The reduction in the extent of spoilage was unrelated to viable cell density in the inoculated wounds. This is the first paper providing direct evidence regarding the application of an antimicrobial peptide to control microbial spoilage affecting RTE leafy vegetables during cold storage.

Pseudomonas aeruginosa inhibits the growth of Cryptococcus species.

PubMed

Rella, Antonella; Yang, Mo Wei; Gruber, Jordon; Montagna, Maria Teresa; Luberto, Chiara; Zhang, Yong-Mei; Del Poeta, Maurizio

2012-06-01

Pseudomonas aeruginosa is a ubiquitous and opportunistic bacterium that inhibits the growth of different microorganisms, including Gram-positive bacteria and fungi such as Candida spp. and Aspergillus fumigatus. In this study, we investigated the interaction between P. aeruginosa and Cryptococcus spp. We found that P. aeruginosa PA14 and, to a lesser extent, PAO1 significantly inhibited the growth of Cryptococcus spp. The inhibition of growth was observed on solid medium by the visualization of a zone of inhibition of yeast growth and in liquid culture by viable cell counting. Interestingly, such inhibition was only observed when P. aeruginosa and Cryptococcus were co-cultured. Minimal inhibition was observed when cell-cell contact was prevented using a separation membrane, suggesting that cell contact is required for inhibition. Using mutant strains of Pseudomonas quinoline signaling, we showed that P. aeruginosa inhibited the growth of Cryptococcus spp. by producing antifungal molecules pyocyanin, a redox-active phenazine, and 2-heptyl-3,4-dihydroxyquinoline (PQS), an extracellular quorum-sensing signal. Because both P. aeruginosa and Cryptococcus neoformans are commonly found in lung infections of immunocompromised patients, this study may have important implication for the interaction of these microbes in both an ecological and a clinical point of view.

Growth inhibition of Listeria spp. on Camembert cheese by bacteria producing inhibitory substances.

PubMed

Sulzer, G; Busse, M

1991-12-01

Bacterial strains exhibiting antimicrobial activity towards other bacteria are quite common in nature. During the past few years several genera have been shown to exert inhibitory action against Listeria. spp. In the present work strains of Enterococcus, Lactobacillus and Lactococcus were tested for their influence on the development of Listeria spp. on Camembert cheese. Partial or complete inhibition of growth of Listeria spp. was observed using various inhibitory bacteria. Complete inhibition occurred when the inhibitory strain was used as a starter culture and there was a low level of contamination with Listeria spp. during the first stage of ripening. Very little inhibition occurred if the inhibitory strain was added together with the starter culture.

Colonizing ability of Pseudomonas fluorescens 2112, among collections of 2,4-diacetylphloroglucinol-producing Pseudomonas fluorescens spp. in pea rhizosphere.

USDA-ARS?s Scientific Manuscript database

Pseudomonas fluorescens 2112, isolated in Korea as an indigenous antagonistic bacteria, can produce 2,4-diacetylphloroglucinol (2,4-DAPG) and the siderophore pyoveridin2112 for the control of Phytophthora blight of red-pepper. P. fluorescens 2112 was classified into a new genotype C among the 17 gen...

Sensitivity of Rhizoctonia Isolates to Phenazine-1-Carboxylic Acid and Biological Control by Phenazine-Producing Pseudomonas spp.

PubMed

Jaaffar, Ahmad Kamil Mohd; Parejko, James A; Paulitz, Timothy C; Weller, David M; Thomashow, Linda S

2017-06-01

Rhizoctonia solani anastomosis groups (AG)-8 and AG-2-1 and R. oryzae are ubiquitous in cereal-based cropping systems of the Columbia Plateau of the Inland Pacific Northwest and commonly infect wheat. AG-8 and R. oryzae, causal agents of Rhizoctonia root rot and bare patch, are most commonly found in fields in the low-precipitation zone, whereas R. solani AG-2-1 is much less virulent on wheat and is distributed in fields throughout the low-, intermediate-, and high-precipitation zones. Fluorescent Pseudomonas spp. that produce the antibiotic phenazine-1-carboxylic acid (PCA) also are abundant in the rhizosphere of crops grown in the low-precipitation zone but their broader geographic distribution and effect on populations of Rhizoctonia is unknown. To address these questions, we surveyed the distribution of PCA producers (Phz + ) in 59 fields in cereal-based cropping systems throughout the Columbia Plateau. Phz + Pseudomonas spp. were detected in 37 of 59 samples and comprised from 0 to 12.5% of the total culturable heterotrophic aerobic rhizosphere bacteria. The frequency with which individual plants were colonized by Phz + pseudomonads ranged from 0 to 100%. High and moderate colonization frequencies of Phz + pseudomonads were associated with roots from fields located in the driest areas whereas only moderate and low colonization frequencies were associated with crops where higher annual precipitation occurs. Thus, the geographic distribution of Phz + pseudomonads overlaps closely with the distribution of R. solani AG-8 but not with that of R. oryzae or R. solani AG-2-1. Moreover, linear regression analysis demonstrated a highly significant inverse relationship between annual precipitation and the frequency of rhizospheres colonized by Phz + pseudomonads. Phz + pseudomonads representative of the four major indigenous species (P. aridus, P. cerealis, P. orientalis, and P. synxantha) suppressed Rhizoctonia root rot of wheat when applied as seed treatments. In vitro

Mining Genomes of Biological Control Strains of Pseudomonas spp.: Unexpected Gems and Tailings

USDA-ARS?s Scientific Manuscript database

The biocontrol bacterium Pseudomonas fluorescens Pf-5 suppresses numerous soilborne plant diseases and produces an array of structurally-characterized secondary metabolites that are toxic to plant pathogenic bacteria, fungi and Oomycetes. Biosynthetic gene clusters for these metabolites compose nea...

Isolation and Characterization of Pseudomonas spp. Strains That Efficiently Decompose Sodium Dodecyl Sulfate

PubMed Central

Furmanczyk, Ewa M.; Kaminski, Michal A.; Spolnik, Grzegorz; Sojka, Maciej; Danikiewicz, Witold; Dziembowski, Andrzej; Lipinski, Leszek; Sobczak, Adam

2017-01-01

Due to their particular properties, detergents are widely used in household cleaning products, cosmetics, pharmaceuticals, and in agriculture as adjuvants tailoring the features of pesticides or other crop protection agents. The continuously growing use of these various products means that water soluble detergents have become one of the most problematic groups of pollutants for the aquatic and terrestrial environments. Thus it is important to identify bacteria having the ability to survive in the presence of large quantities of detergent and efficiently decompose it to non-surface active compounds. In this study, we used peaty soil sampled from a surface flow constructed wetland in a wastewater treatment plant to isolate bacteria that degrade sodium dodecyl sulfate (SDS). We identified and initially characterized 36 Pseudomonas spp. strains that varied significantly in their ability to use SDS as their sole carbon source. Five isolates having the closest taxonomic relationship to the Pseudomonas jessenii subgroup appeared to be the most efficient SDS degraders, decomposing from 80 to 100% of the SDS present in an initial concentration 1 g/L in less than 24 h. These isolates exhibited significant differences in degree of SDS degradation, their resistance to high detergent concentration (ranging from 2.5 g/L up to 10 g/L or higher), and in chemotaxis toward SDS on a plate test. Mass spectrometry revealed several SDS degradation products, 1-dodecanol being dominant; however, traces of dodecanal, 2-dodecanol, and 3-dodecanol were also observed, but no dodecanoic acid. Native polyacrylamide gel electrophoresis zymography revealed that all of the selected isolates possessed alkylsulfatase-like activity. Three isolates, AP3_10, AP3_20, and AP3_22, showed a single band on native PAGE zymography, that could be the result of alkylsulfatase activity, whereas for isolates AP3_16 and AP3_19 two bands were observed. Moreover, the AP3_22 strain exhibited a band in presence of

Indigenous Halomonas spp., the Potential Nitrifying Bacteria for Saline Ammonium Waste Water Treatment.

PubMed

Sangnoi, Yutthapong; Chankaew, Sunipa; O-Thong, Sompong

2017-01-01

Toxic nitrogen compounds are one cause decreasing of shrimp production and water pollution. Indigenous Halomonas spp., isolated from Pacific white shrimp farm are benefitted for saline ammonium waste water treatment. This study aimed to isolate the heterotrophic-halophilic Halomonas spp. and investigate their ammonium removal efficiency. Halomonas spp., were isolated by culturing of samples collected from shrimp farm into modified Pep-Beef-AOM medium. Ammonium converting ability was tested and monitored by nitrite reagent. Ammonium removal efficiency was measured by the standard colorimetric method. Identification and classification of Halomonas spp., were studied by morphological, physiological and biochemical characteristics as well as molecular information. There were 5 strains of heterotrophic-halophilic nitrifying bacteria including SKNB2, SKNB4, SKNB17, SKNB20 and SKNB22 were isolated. The identification result based on 16S rRNA sequence analysis indicated that all 5 strains were Halomonas spp., with sequence similarity values of 91-99 %. Ammonium removal efficiency of all strains showed a range of 23-71%. The production of nitrite was low detected of 0.01-0.15 mg-N L-1, while the amount of nitrate was almost undetectable. This might suggest that the indigenous Halomonas spp., as nitrifying bacteria involved biological nitrification process for decreasing and transforming of ammonia. Due to being heterotrophic, halophilic and ammonium removing bacteria, these Halomonas spp., could be developed for use in treatment of saline ammonium waste water.

Indigenous Pseudomonas spp. Strains from the Olive (Olea europaea L.) Rhizosphere as Effective Biocontrol Agents against Verticillium dahliae: From the Host Roots to the Bacterial Genomes

PubMed Central

Gómez-Lama Cabanás, Carmen; Legarda, Garikoitz; Ruano-Rosa, David; Pizarro-Tobías, Paloma; Valverde-Corredor, Antonio; Niqui, José L.; Triviño, Juan C.; Roca, Amalia; Mercado-Blanco, Jesús

2018-01-01

The use of biological control agents (BCA), alone or in combination with other management measures, has gained attention over the past decades, driven by the need to seek for sustainable and eco-friendly alternatives to confront plant pathogens. The rhizosphere of olive (Olea europaea L.) plants is a source of bacteria with potential as biocontrol tools against Verticillium wilt of olive (VWO) caused by Verticillium dahliae Kleb. A collection of bacterial isolates from healthy nursery-produced olive (cultivar Picual, susceptible to VWO) plants was generated based on morphological, biochemical and metabolic characteristics, chemical sensitivities, and on their in vitro antagonistic activity against several olive pathogens. Three strains (PIC25, PIC105, and PICF141) showing high in vitro inhibition ability of pathogens' growth, particularly against V. dahliae, were eventually selected. Their effectiveness against VWO caused by the defoliating pathotype of V. dahliae was also demonstrated, strain PICF141 being the rhizobacteria showing the best performance as BCA. Genotypic and phenotypic traits traditionally associated with plant growth promotion and/or biocontrol abilities were evaluated as well (e.g., phytase, xylanase, catalase, cellulase, chitinase, glucanase activities, and siderophore and HCN production). Multi-locus sequence analyses of conserved genes enabled the identification of these strains as Pseudomonas spp. Strain PICF141 was affiliated to the “Pseudomonas mandelii subgroup,” within the “Pseudomonas fluorescens group,” Pseudomonas lini being the closest species. Strains PIC25 and PIC105 were affiliated to the “Pseudomonas aeruginosa group,” Pseudomonas indica being the closest relative. Moreover, we identified P. indica (PIC105) for the first time as a BCA. Genome sequencing and in silico analyses allowed the identification of traits commonly associated with plant-bacteria interactions. Finally, the root colonization ability of these olive

Indigenous Pseudomonas spp. Strains from the Olive (Olea europaea L.) Rhizosphere as Effective Biocontrol Agents against Verticillium dahliae: From the Host Roots to the Bacterial Genomes.

PubMed

Gómez-Lama Cabanás, Carmen; Legarda, Garikoitz; Ruano-Rosa, David; Pizarro-Tobías, Paloma; Valverde-Corredor, Antonio; Niqui, José L; Triviño, Juan C; Roca, Amalia; Mercado-Blanco, Jesús

2018-01-01

The use of biological control agents (BCA), alone or in combination with other management measures, has gained attention over the past decades, driven by the need to seek for sustainable and eco-friendly alternatives to confront plant pathogens. The rhizosphere of olive ( Olea europaea L.) plants is a source of bacteria with potential as biocontrol tools against Verticillium wilt of olive (VWO) caused by Verticillium dahliae Kleb. A collection of bacterial isolates from healthy nursery-produced olive (cultivar Picual, susceptible to VWO) plants was generated based on morphological, biochemical and metabolic characteristics, chemical sensitivities, and on their in vitro antagonistic activity against several olive pathogens. Three strains (PIC25, PIC105, and PICF141) showing high in vitro inhibition ability of pathogens' growth, particularly against V. dahliae , were eventually selected. Their effectiveness against VWO caused by the defoliating pathotype of V. dahliae was also demonstrated, strain PICF141 being the rhizobacteria showing the best performance as BCA. Genotypic and phenotypic traits traditionally associated with plant growth promotion and/or biocontrol abilities were evaluated as well (e.g., phytase, xylanase, catalase, cellulase, chitinase, glucanase activities, and siderophore and HCN production). Multi-locus sequence analyses of conserved genes enabled the identification of these strains as Pseudomonas spp. Strain PICF141 was affiliated to the " Pseudomonas mandelii subgroup," within the " Pseudomonas fluorescens group," Pseudomonas lini being the closest species. Strains PIC25 and PIC105 were affiliated to the " Pseudomonas aeruginosa group," Pseudomonas indica being the closest relative. Moreover, we identified P. indica (PIC105) for the first time as a BCA. Genome sequencing and in silico analyses allowed the identification of traits commonly associated with plant-bacteria interactions. Finally, the root colonization ability of these olive

A survey of the prevalence of selected bacteria in wild birds

USGS Publications Warehouse

Brittingham, M.C.; Temple, S.A.; Duncan, R.M.

1988-01-01

We determined the prevalence of six genera of bacteria from a sample of 387 cloacal swabs from 364 passerines and woodpeckers. The prevalence of bacteria were as follows: Escherichia coli (1%), Pseudomonas spp. (22%), Salmonella spp. (0%), Staphylococcus spp. (15%), Streptococcus spp. (18%), and Yersinia spp. (1%). The prevalence of Streptococcus spp. was higher in omnivorous species than in granivorous species (20% versus 8%). Individuals captured at feeders had a lower prevalence of both Streptococcus spp. (15% versus 33%) and Escherichia coli (0.5% versus 4%) than birds that did not have access to feeders. These differences are probably not due to the feeder per se, but instead to other site related differences. The prevalence of bacteria did not differ between male and female black-capped chickadees, Parus atricapillus. For 279 color marked black-capped chickadees, we calculated the cumulative mortality rate during 12 wk following swabbing. Although the cumulative mortality rates of infected birds were consistently higher than the rates of non-infected birds, none of these differences were significant. Infections may cause slight reductions in survival rates, but we were not able to confirm this with our data.

Molecular Detection of Legionella spp. and their associations with Mycobacterium spp., Pseudomonas aeruginosa and amoeba hosts in a drinking water distribution system.

PubMed

Lu, J; Struewing, I; Vereen, E; Kirby, A E; Levy, K; Moe, C; Ashbolt, N

2016-02-01

This study investigated waterborne opportunistic pathogens (OPs) including potential hosts, and evaluated the use of Legionella spp. for indicating microbial water quality for OPs within a full-scale operating drinking water distribution system (DWDS). To investigate the occurrence of specific microbial pathogens within a major city DWDS we examined large volume (90 l drinking water) ultrafiltration (UF) concentrates collected from six sites between February, 2012 and June, 2013. The detection frequency and concentration estimates by qPCR were: Legionella spp. (57%/85 cell equivalent, CE l(-1) ), Mycobacterium spp. (88%/324 CE l(-1) ), Pseudomonas aeruginosa (24%/2 CE l(-1) ), Vermamoeba vermiformis (24%/2 CE l(-1) ) and Acanthamoeba spp. (42%/5 cyst equivalent, CE l(-1) ). There was no detection of the following microorganisms: human faecal indicator Bacteroides (HF183), Salmonella enterica, Campylobacter spp., Escherichia coli O157:H7, Giardia intestinalis, Cryptosporidium spp. or Naegleria fowleri. There were significant correlations between the qPCR signals of Legionella spp. and Mycobacterium spp., and their potential hosts V. vermiformis and Acanthamoeba spp. Sequencing of Legionella spp. demonstrated limited diversity, with most sequences coming from two dominant groups, of which the larger dominant group was an unidentified species. Other known species including Legionella pneumophila were detected, but at low frequency. The densities of Legionella spp. and Mycobacterium spp. were generally higher (17 and 324 folds, respectively) for distal sites relative to the entry point to the DWDS. Legionella spp. occurred, had significant growth and were strongly associated with free-living amoebae (FLA) and Mycobacterium spp., suggesting that Legionella spp. could provide a useful DWDS monitoring role to indicate potential conditions for non-faecal OPs. The results provide insight into microbial pathogen detection that may aid in the monitoring of microbial water

Chemical Modification and Detoxification of the Pseudomonas aeruginosa Toxin 2-Heptyl-4-hydroxyquinoline N-Oxide by Environmental and Pathogenic Bacteria.

PubMed

Thierbach, Sven; Birmes, Franziska S; Letzel, Matthias C; Hennecke, Ulrich; Fetzner, Susanne

2017-09-15

2-Heptyl-4-hydroxyquinoline N-oxide (HQNO), a major secondary metabolite and virulence factor produced by the opportunistic pathogen Pseudomonas aeruginosa, acts as a potent inhibitor of respiratory electron transfer and thereby affects host cells as well as microorganisms. In this study, we demonstrate the previously unknown capability of environmental and pathogenic bacteria to transform and detoxify this compound. Strains of Arthrobacter and Rhodococcus spp. as well as Staphylococcus aureus introduced a hydroxyl group at C-3 of HQNO, whereas Mycobacterium abscessus, M. fortuitum, and M. smegmatis performed an O-methylation, forming 2-heptyl-1-methoxy-4-oxoquinoline as the initial metabolite. Bacillus spp. produced the glycosylated derivative 2-heptyl-1-(β-d-glucopyranosydyl)-4-oxoquinoline. Assaying the effects of these metabolites on cellular respiration and on quinol oxidase activity of membrane fractions revealed that their EC 50 values were up to 2 orders of magnitude higher than that of HQNO. Furthermore, cellular levels of reactive oxygen species were significantly lower in the presence of the metabolites than under the influence of HQNO. Therefore, the capacity to transform HQNO should lead to a competitive advantage against P. aeruginosa. Our findings contribute new insight into the metabolic diversity of bacteria and add another layer of complexity to the metabolic interactions which likely contribute to shaping polymicrobial communities comprising P. aeruginosa.

Cyanogenic Pseudomonas spp. strains are concentrated in the rhizosphere of alpine pioneer plants.

PubMed

Rijavec, Tomaž; Lapanje, Aleš

2017-01-01

HCN producing bacteria have previously been isolated from alpine mineral soil and their ecophysiology was presumed to be associated with mineral weathering. Nevertheless, the high ecological patchiness of the alpine environment calls for an extensive and detailed analysis of the spatial distribution of HCN producing bacterial populations and their associated weathering traits. Our results of such an analysis showed that primarily the rhizosphere of pioneer plants was rich in HPPs, harbouring the most potent HCN producers. HCN production incidence and intensity were dependent on the plant-associated microhabitat and type of bedrock/mineral soil, however the HCN+ phenotype was not associated with one of the particular genotypes which we determined by BOX-PCR. In HPP isolates, HCN production most commonly co-occurred with the production of hydroxamate-type siderophores, but was less often associated with inorganic phosphate solubilization activity and the production of catechol-type siderophores. These observations indicate that a plant's physiotype, not species, provide physicochemical conditions that determine selective pressure, which enables the growth of Pseudomonas spp. with a random genotype, but phenotypically predetermined to increase mineral weathering via a particular combination of phosphate solubilization and iron complexation with siderophores and HCN. Copyright © 2016 Elsevier GmbH. All rights reserved.

[Production of inhibiting plant growth and development hormones by pathogenic for legumes Pseudomonas genus bacteria].

PubMed

Dankevich, L A

2013-01-01

It has been studied the ability of pathogenic for legumes pathovars of Pseudomonas genus to produce ethylene and abscisic acid in vitro. A direct correlation between the level of ethylene production by agent of bacterial pea burn--Pseudomonas syringae pv. pisi and level of its aggressiveness for plants has been found. It is shown that the amount of abscisic acid synthesized by pathogenic for legumes Pseudomonas genus bacteria correlates with their aggressiveness for plants.

Virulence of plant pathogenic bacteria attenuated by degradation of fatty acid cell-to-cell signaling factors.

PubMed

Newman, Karyn L; Chatterjee, Subhadeep; Ho, Kimberly A; Lindow, Steven E

2008-03-01

Diffusible signal factor (DSF) is a fatty acid signal molecule involved in regulation of virulence in several Xanthomonas species as well as Xylella fastidiosa. In this study, we identified a variety of bacteria that could disrupt DSF-mediated induction of virulence factors in Xanthomonas campestris pv. campestris. While many bacteria had the ability to degrade DSF, several bacterial strains belonging to genera Bacillus, Paenibacillus, Microbacterium, Staphylococcus, and Pseudomonas were identified that were capable of particularly rapid degradation of DSF. The molecular determinants for rapid degradation of DSF in Pseudomonas spp. strain G were elucidated. Random transposon mutants of strain G lacking the ability to degrade DSF were isolated. Cloning and characterization of disrupted genes in these strains revealed that carAB, required for the synthesis of carbamoylphosphate, a precursor for pyrimidine and arginine biosynthesis is required for rapid degradation of DSF in strain G. Complementation of carAB mutants restored both pyrimidine prototrophy and DSF degradation ability of the strain G mutant. An Escherichia coli strain harboring carAB of Pseudomonas spp. strain G degrades DSF more rapidly than the parental strain, and overexpression of carAB in trans increased the ability of Pseudomonas spp. strain G to degrade as compared with the parental strain. Coinoculation of X. campestris pv. campestris with DSF-degrading bacteria into mustard and cabbage leaves reduced disease severity up to twofold compared with plants inoculated only with the pathogen. Likewise, disease incidence and severity in grape stems coinoculated with Xylella fastidiosa and DSF-degrading strains were significantly reduced compared with plants inoculated with the pathogen alone. Coinoculation of grape plants with a carAB mutant of Pseudomonas spp. strain G complemented with carAB in trans reduced disease severity as well or better than the parental strain. These results indicate that

Residual effect of storage in an elevated carbon dioxide atmosphere on the microbial flora of rock cod (Sebastes spp. )

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, M.Y.; Ogrydziak, D.M.

1986-10-01

A residual inhibitory effect on microbial growth due to modified-atmosphere (MA) storage (MA, 80% CO/sub 2/-20% air) was demonstrated for rock cod fillets stored in MA and transferred to air at 4/sup 0/C. Results of measurements of CO/sub 2/ concentrations of the fillets suggested that the residual effect after transfer from MA to air was not due to retention of CO/sup 2/ at the surface of the fillets but was probably due to the microbial ecology of the system. Lactobacillus spp. and tan Alteromonas spp. (TAN) predominated after 7 and 14 days of storage in MA. During storage in MA,more » Pseudomonas spp. were inhibited or killed. Following transfer from MA to air, the percentage of the total flora represented by Lactobacillus spp. and TAN bacteria decreased, and 6 days after transfer Pseudomonas spp. were again dominant.« less

[Multiresistant Pseudomonas spp. in vitro susceptibility to a combination of two antibiotics].

PubMed

Pliego-Castañeda, Q F B Amanda; Yánez-Viguri, Jorge Antonio; López-Valle, Tiburcio

2005-01-01

In vitro antibiotic combination testing would guide therapy selection in patients severely affected by multi-drug resistant Pseudomonas. In vitro, a two-antibiotic combination susceptible against multi-drug resistant Pseudomonas isolated at the Laboratorio Clínico of the Hospital de Oncología, Centro Médico Nacional Siglo XXI in Mexico City were analyzed to determine which antibiotic combination showed the best bactericidal activity. During 10 months, 30 multi-drug resistant Pseudomonas strains were tested. An automated method was used, including a diluting solution with a well-known concentration of a second antibiotic. Quality controls recommended by the NCCLS were used. Pseudomonas aeruginosa ATCC 27853; Escherichia coli ATCC 25922; and Escherichia coli ATCC 35218. Combinations were betalactamics-aminoglycosides; carbapenemis-amikacin; fluoroquinolones-cefepime; and ciprofloxacin-ampicillin. Ampicillin-ciprofloxacin combination was bactericidal against 100% of the isolates. Cefazolin, cefixime and ticarcillin with amikacin: <50%; aztreonam, cefoxilin, cefuroxime, cefotaxime, ceftazidime and piperacillin with amikacin: 50-60%; cefepime with gentamicin: 76%; cefepime with amikacin: 86%; imipenem and meropenem with amikacin: 70% and 76%; cefepime with ciprofloxacin: 83%; cefepime with levofloxacin: 73%. In vitro antibiotic combination susceptibilities against multi-drug resistant bacteria would be the only way to guide clinicians to select the best therapy in severe infections. We found that the ampicillin-ciprofloxacin combination showed the best in vitro effect against multi-drug resistant Pseudomonas.

Biofilm and metallo beta-lactamase production among the strains of Pseudomonas aeruginosa and Acinetobacter spp. at a Tertiary Care Hospital in Kathmandu, Nepal.

PubMed

Baniya, Bandana; Pant, Narayan Dutt; Neupane, Sanjeev; Khatiwada, Saroj; Yadav, Uday Narayan; Bhandari, Nisha; Khadka, Rama; Bhatta, Sabita; Chaudhary, Raina

2017-11-02

Pseudomonas aeruginosa and Acinetobacter spp. are found to be associated with biofilm and metallo-β-lactamase production and are the common causes of serious infections mainly in hospitalized patients. So, the main aims of this study were to determine the rates of biofilm production and metallo beta-lactamase production (MBL) among the strains of Pseudomonas aeruginosa and Acinetobacter spp. isolated from hospitalized patients. A total of 85 P. aeruginosa isolates and 50 Acinetobacter spp. isolates isolated from different clinical specimens from patients admitted to Shree Birendra Hospital, Kathmandu, Nepal from July 2013 to May 2014 were included in this study. The bacterial isolates were identified with the help of biochemical tests. Modified Kirby-Bauer disc diffusion technique was used for antimicrobial susceptibility testing. Combined disc diffusion technique was used for the detection of MBL production, while Congo red agar method and tube adherence method were used for detection of biofilm production. Around 16.4% of P. aeruginosa isolates and 22% of the strains of Acinetobacter spp. were metallo β-lactamase producers. Out of 85 P. aeruginosa isolates, 23 (27.05%) were biofilm producers according to tube adherence test while, only 13 (15.29%) were biofilm producers as per Congo red agar method. Similarly, out of 50 Acinetobacter spp. 7 (14%) isolates were biofilm producers on the basis of tube adherence test, while only 5 (10%) were positive for biofilm production by Congo red agar method. Highest rates of susceptibility of P. aeruginosa as well as Acinetobacter spp. were seen toward colistin. In our study, biofilm production and metallo beta-lactamase production were observed among Pseudomonas aeruginosa and Acinetobacter spp. However, no statistically significant association could be established between biofilm production and metallo beta-lactamase production.

Investigation of tick-borne bacteria (Rickettsia spp., Anaplasma spp., Ehrlichia spp. and Borrelia spp.) in ticks collected from Andean tapirs, cattle and vegetation from a protected area in Ecuador.

PubMed

Pesquera, Cristina; Portillo, Aránzazu; Palomar, Ana M; Oteo, José A

2015-01-24

Ixodid ticks play an important role in the transmission and ecology of infectious diseases. Information about the circulation of tick-borne bacteria in ticks is lacking in Ecuador. Our aims were to investigate the tick species that parasitize Andean tapirs and cattle, and those present in the vegetation from the buffer zone of the Antisana Ecological Reserve and Cayambe-Coca National Park (Ecuador), and to investigate the presence of tick-borne bacteria. Tick species were identified based on morphologic and genetic criteria. Detection of tick-borne bacteria belonging to Rickettsia, Anaplasma, Ehrlichia and Borrelia genera was performed by PCRs. Our ticks included 91 Amblyomma multipunctum, 4 Amblyomma spp., 60 Rhipicephalus microplus, 5 Ixodes spp. and 1 Ixodes boliviensis. A potential Candidatus Rickettsia species closest to Rickettsia monacensis and Rickettsia tamurae (designated Rickettsia sp. 12G1) was detected in 3 R. microplus (3/57, 5.3%). In addition, Anaplasma spp., assigned at least to Anaplasma phagocytophilum (or closely related genotypes) and Anaplasma marginale, were found in 2 A. multipunctum (2/87, 2.3%) and 13 R. microplus (13/57, 22.8%). This is the first description of Rickettsia sp. in ticks from Ecuador, and the analyses of sequences suggest the presence of a potential novel Rickettsia species. Ecuadorian ticks from Andear tapirs, cattle and vegetation belonging to Amblyomma and Rhipicephalus genera were infected with Anaplasmataceae. Ehrlichia spp. and Borrelia burgdorferi sensu lato were not found in any ticks.

Genetically modified luminescent bacteria Ralostonia solanacerum, Pseudomonas syringae, Pseudomonas savastanoi, and wild type bacterium Vibrio fischeri in biosynthesis of gold nanoparticles from gold chloride trihydrate.

PubMed

Attaran, Neda; Eshghi, Hossein; Rahimizadeh, Mohammad; Mashreghi, Mansour; Bakavoli, Mehdi

2014-08-04

The effect of different genetically engineered bacteria, Pseudomonas syringae, Pseudomonas savastanoi, and Ralostonia solanacerum and also a natural marine bacterial species, Vibrio fischeri NRRL B-11177, is studied in producing gold nanoparticles. This is the first report about the biosynthesis of gold nanoparticles by natural and genetically engineered luminescent bacteria. These microorganisms reduced gold ions and produced fairly monodisperse nanoparticles. TEM analysis indicated that spherical nano gold particles in the different diameters and shapes were obtained at pH values of 6.64. In this biosynthesis protocol, the gold nanoparticles with desired shape and size can be prepared.

Brachiaria Grasses (Brachiaria spp.) harbor a diverse bacterial community with multiple attributes beneficial to plant growth and development.

PubMed

Mutai, Collins; Njuguna, Joyce; Ghimire, Sita

2017-10-01

Endophytic and plant-associated bacteria were isolated from plants and rhizoplane soil of naturally grown Brachiaria grasses at International Livestock Research Institute in Nairobi, Kenya. Eighty-four bacterial strains were isolated from leaf tissues, root tissues, and rhizoplane soil on nutrient agar and 869 media. All bacterial strains were identified to the lowest possible taxonomic unit using 16S rDNA primers and were characterized for the production of Indole-3-acetic acid, hydrogen cyanide, and ACC deaminase; phosphate solubilization; siderophore production; antifungal properties; and plant biomass production. The 16S rDNA-based identification grouped these 84 bacterial strains into 3 phyla, 5 classes, 8 orders, 12 families, 16 genera, and 50 unique taxa. The four most frequently isolated genera were Pseudomonas (23), Pantoea (17), Acinetobacter (9), and Enterobacter (8). The functional characterization of these strains revealed that 41 of 84 strains had a minimum of three plant beneficial properties. Inoculation of maize seedlings with Acinetobacter spp., Microbacterium spp., Pectobacterium spp., Pseudomonas spp., and Enterobacter spp. showed positive effects on seedling biomass production. The ability of Brachiaria grasses to host genetically diverse bacteria, many of them with multiple plant growth-promoting attributes, might have contributed to high biomass production and adaptation of Brachiaria grasses to drought and low fertility soils. © 2017 International Livestock Research Institute. MicrobiologyOpen published by John Wiley & Sons Ltd.

Bioaccumulation of pathogenic bacteria and amoeba by zebra mussels and their presence in watercourses.

PubMed

Mosteo, R; Goñi, P; Miguel, N; Abadías, J; Valero, P; Ormad, M P

2016-01-01

Dreissena polymorpha (the zebra mussel) has been invading freshwater bodies in Europe since the beginning of the nineteenth century. Filter-feeding organisms can accumulate and concentrate both chemical and biological contaminants in their tissues. Therefore, zebra mussels are recognized as indicators of freshwater quality. In this work, the capacity of the zebra mussel to accumulate human pathogenic bacteria and protozoa has been evaluated and the sanitary risk associated with their presence in surface water has also been assessed. The results show a good correlation between the pathogenic bacteria concentration in zebra mussels and in watercourses. Zebra mussels could therefore be used as an indicator of biological contamination. The bacteria (Escherichia coli, Enterococcus spp., Pseudomonas spp., and Salmonella spp.) and parasites (Cryptosporidium oocysts and free-living amoebae) detected in these mussels reflect a potential sanitary risk in water.

The bioleaching feasibility for Pb/Zn smelting slag and community characteristics of indigenous moderate-thermophilic bacteria.

PubMed

Cheng, Yi; Guo, Zhaohui; Liu, Xueduan; Yin, Huaqun; Qiu, Guanzhou; Pan, Fengkai; Liu, Hongwei

2009-05-01

The feasibility of recovering metal values and removing hazardous elements from the Pb/Zn smelting slag using bioleaching technique were studied through a flask experiment, and the community characteristics of the indigenous moderate-thermophilic bacteria in this bioleaching system were also analyzed through a culture-independent restriction fragment length polymorphism (RFLP) of 16S rRNA genes approach. The results show that more than 80% of Al, As, Cu, Mn, Fe and Zn in the Pb/Zn smelting slag were leached at 65(o)C, pH 1.5, pulp density 5%, but only about 5% of Pb. Phylogenetic analysis revealed that the bacteria in the bioleaching system mainly fell among Firmicutes, Gammaproteobacteria and Betaproteobacteria, and the dominant bacteria are affiliated with Bacillus spp., Sporosarcina spp. and Pseudomonas spp.

Identification of free-living amoebae and amoeba-associated bacteria from reservoirs and water treatment plants by molecular techniques.

PubMed

Garcia, Alicia; Goñi, Pilar; Cieloszyk, Joanna; Fernandez, Maria Teresa; Calvo-Beguería, Laura; Rubio, Encarnacion; Fillat, Maria Francisca; Peleato, Maria Luisa; Clavel, Antonio

2013-04-02

The occurrence of free-living amoebae (FLA) was investigated in 83 water samples from reservoirs and water treatment plants, with culture positive in 64 of them (77.1%). Polymerase chain reaction (PCR) of partial 18S rRNA gene and ITS region was performed in order to identify amoeba isolates, and the presence of Legionella pneumophila , Mycobacterium spp., Pseudomonas spp., and Microcystis aeruginosa was investigated in 43 isolates of amoebae by multiplex PCR. Of the isolated amoebae, 31 were Acanthamoeba spp., 21 were Hartmannella vermiformis, 13 were Naegleria spp., and one was Vanella spp. T2, T4, and T5 genotypes of Acanthamoeba have been identified, and T4 isolates were grouped into five subgenotypes and graphically represented with a Weblog application. Inside amoebae, L. pneumophila was detected in 13.9% (6/43) of the isolates, and Pseudomonas spp. and Mycobacterium spp. were detected in 32.6% (14/43) and 41.9% (18/43), respectively. No statistical correlation was demonstrated between FLA isolation and seasonality, but the presence of intracellular bacteria was associated with warm water temperatures, and also the intracellular presence of Mycobacterium spp. and Pseudomonas spp. were associated. These results highlight the importance of amoebae in natural waters as reservoirs of potential pathogens and its possible role in the spread of bacterial genera with interest in public and environmental health.

Influence of regular reporting on local Pseudomonas aeruginosa and Acinetobacter spp. sensitivity to antibiotics on consumption of antibiotics and resistance patterns.

PubMed

Djordjevic, Z M; Folic, M M; Jankovic, S M

2017-10-01

Regular surveillance of antimicrobial resistance is an important component of multifaceted interventions directed at the problem with resistance of bacteria causing healthcare-associated infections (HAIs) in intensive care units (ICUs). Our aim was to analyse antimicrobial consumption and resistance among isolates of Pseudomonas aeruginosa and Acinetobacter spp. causing HAIs, before and after the introduction of mandatory reporting of resistance patterns to prescribers. A retrospective observational study was conducted between January 2011 and December 2015, at an interdisciplinary ICU of the Clinical Centre Kragujevac, Serbia. The intervention consisted of continuous resistance monitoring of all bacterial isolates from ICU patients and biannual reporting of results per isolate to prescribers across the hospital. Both utilization of antibiotics and density of resistant isolates of P. aeruginosa and Acinetobacter spp. were followed within the ICU. Resistance densities of P. aeruginosa to all tested antimicrobials were lower in 2015, in comparison with 2011. Although isolates of Acinetobacter spp. had lower resistance density in 2015 than in 2011 to the majority of investigated antibiotics, a statistically significant decrease was noted only for piperacillin/tazobactam. Statistically significant decreasing trends of consumption were recorded for third-generation cephalosporins, aminoglycosides and fluoroquinolones, whereas for the piperacillin/tazobactam, ampicillin/sulbactam and carbapenems, utilization trends were decreasing, but without statistical significance. In the same period, increasing trends of consumption were observed for tigecycline and colistin. Regular monitoring of resistance of bacterial isolates in ICUs and reporting of summary results to prescribers may lead to a significant decrease in utilization of some antibiotics and slow restoration of P. aeruginosa and Acinetobacter spp. susceptibility. © 2017 John Wiley & Sons Ltd.

Two symbiotic bacteria of the entomopathogenic nematode Heterorhabditis spp. against Galleria mellonella.

PubMed

Liao, Chunli; Gao, Along; Li, Bingbing; Wang, Mengjun; Shan, Linna

2017-03-01

The entomopathogenic nematode Heterorhabditis spp. is considered a promising agent in the biocontrol of injurious insects of agriculture. However, different symbiotic bacteria associated with the nematode usually have different specificity and virulence toward their own host. In this study, two symbiotic bacteria, LY2W and NK, were isolated from the intestinal canals of two entomopathogenic nematode Heterorhabditis megidis 90 (PDSj1 and PDSj2) from Galleria mellonela, separately. To determine their species classification, we carried out some investigations on morphology, culture, biochemistry, especially 16S rDNA sequence analyses. As a result, both of them belong to Enterobacter spp., showing the closest relatedness with Enterobacter gergoviae (LY2W) and Enterobacter cloacae (NK), respectively. Moreover, the toxicity to Galleria mellonella was examined using both the metabolites and washed cells (primary and secondary) of these two strains. The results indicated both metabolites and cells of the primary-type bacteria could cause high mortalities (up to 97%) to Galleria mellonella, while those of the primary-type bacteria only killed 20%. These findings would provide new symbiotic bacteria and further references for biological control of the agricultural pest. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Characteristics of natural strains of naphthalene-utilizing bacteria of the genus Pseudomonas].

PubMed

Levchuk, A A; Vasilenko, S L; Bulyga, I M; Titok, M A; Thomas, K M

2005-01-01

Sixty-three strains of bacteria capable of utilizing naphthalene as the sole source of carbon and energy were isolated from 137 samples of soil taken in different sites in Belarus. All isolated bacteria contained extrachromosomal genetic elements of 45 to 150 kb in length. It was found that bacteria of 31 strains contained the IncP-9 incompatibility group plasmids, bacteria of one strain carried a plasmid containing replicons IncP-9 and IncP-7, and bacteria of 31 strains contained unidentified plasmids. Primary identification showed that the hosts of plasmids of naphthalene biodegradation are fluorescent bacteria of the genus Pseudomonas (P. putida and P. aeruginosa; a total of 47 strains) and unidentified nonfluorescent microorganisms (a total of 16 strains). In addition to the ability to utilize naphthalene, some strains exhibited the ability to stimulate the growth and development of the root system of Secale cereale.

Soil burial method for plastic degradation performed by Pseudomonas PL-01, Bacillus PL-01, and indigenous bacteria

NASA Astrophysics Data System (ADS)

Shovitri, Maya; Nafi'ah, Risyatun; Antika, Titi Rindi; Alami, Nur Hidayatul; Kuswytasari, N. D.; Zulaikha, Enny

2017-06-01

Lately, plastic bag is becoming the most important pollutant for environment since it is difficult to be naturally degraded due to it consists of long hydrocarbon polymer chains. Our previous study indicated that our pure isolate Pseudomonas PL-01 and Bacillus PL-01 could degrade about 10% plastic bag. This present study was aimed to find out whether Pseudomonas PL01 and Bacillus PL01 put a positive effect to indigenous bacteria from marginal area in doing plastic degradation with a soil burial method. Beach sand was used as a representative marginal area, and mangrove sediment was used as a comparison. Plastics were submerged into unsterile beach sand with 10% of Pseudomonas PL-01 or Bacillus PL-01 containing liquid minimal salt medium (MSM) separately, while other plastics were submerged into unsterile mangrove sediments. After 4, 8, 12 and 16 weeks, their biofilm formation on their plastic surfaces and plastic degradation were measured. Results indicated that those 2 isolates put positive influent on biofilm formation and plastic degradation for indigenous beach sand bacteria. Bacillus PL-01 put higher influent than Pseudomonas PL-01. Plastic transparent was preferable degraded than black and white plastic bag `kresek'. But anyhow, indigenous mangrove soil bacteria showed the best performance in biofilm formation and plastic degradation, even without Pseudomonas PL-01 or Bacillus PL-01 addition. Fourier Transform Infrared (FTIR) analysis complemented the results; there were attenuated peaks with decreasing peaks transmittances. This FTIR peaks indicated chemical functional group changes happened among the plastic compounds after 16 weeks incubation time.

Threats and opportunities of plant pathogenic bacteria.

PubMed

Tarkowski, Petr; Vereecke, Danny

2014-01-01

Plant pathogenic bacteria can have devastating effects on plant productivity and yield. Nevertheless, because these often soil-dwelling bacteria have evolved to interact with eukaryotes, they generally exhibit a strong adaptivity, a versatile metabolism, and ingenious mechanisms tailored to modify the development of their hosts. Consequently, besides being a threat for agricultural practices, phytopathogens may also represent opportunities for plant production or be useful for specific biotechnological applications. Here, we illustrate this idea by reviewing the pathogenic strategies and the (potential) uses of five very different (hemi)biotrophic plant pathogenic bacteria: Agrobacterium tumefaciens, A. rhizogenes, Rhodococcus fascians, scab-inducing Streptomyces spp., and Pseudomonas syringae. Copyright © 2013 Elsevier Inc. All rights reserved.

Bacteria associated with Amblyomma cajennense tick eggs

PubMed Central

Machado-Ferreira, Erik; Vizzoni, Vinicius Figueiredo; Piesman, Joseph; Gazeta, Gilberto Salles; Soares, Carlos Augusto Gomes

2015-01-01

Abstract Ticks represent a large group of pathogen vectors that blood feed on a diversity of hosts. In the Americas, the Ixodidae ticks Amblyomma cajennense are responsible for severe impact on livestock and public health. In the present work, we present the isolation and molecular identification of a group of culturable bacteria associated with A. cajennense eggs from females sampled in distinct geographical sites in southeastern Brazil. Additional comparative analysis of the culturable bacteria from Anocentor nitens, Rhipicephalus sanguineus and Ixodes scapularis tick eggs were also performed. 16S rRNA gene sequence analyses identified 17 different bacterial types identified as Serratia marcescens, Stenotrophomonas maltophilia, Pseudomonas fluorescens, Enterobacter spp., Micrococcus luteus, Ochrobactrum anthropi, Bacillus cereus and Staphylococcus spp., distributed in 12 phylogroups. Staphylococcus spp., especially S. sciuri, was the most prevalent bacteria associated with A. cajennense eggs, occurring in 65% of the samples and also frequently observed infecting A. nitens eggs. S. maltophilia, S. marcescens and B. cereus occurred infecting eggs derived from specific sampling sites, but in all cases rising almost as pure cultures from infected A. cajennense eggs. The potential role of these bacterial associations is discussed and they possibly represent new targets for biological control strategies of ticks and tick borne diseases. PMID:26537602

Isolation of Environmental Bacteria from Surface and Drinking Water in Mafikeng, South Africa, and Characterization Using Their Antibiotic Resistance Profiles

PubMed Central

Mulamattathil, Suma George; Mbewe, Moses; Ateba, Collins Njie

2014-01-01

The aim of this study was to isolate and identify environmental bacteria from various raw water sources as well as the drinking water distributions system in Mafikeng, South Africa, and to determine their antibiotic resistance profiles. Water samples from five different sites (raw and drinking water) were analysed for the presence of faecal indicator bacteria as well as Aeromonas and Pseudomonas species. Faecal and total coliforms were detected in summer in the treated water samples from the Modimola dam and in the mixed water samples, with Pseudomonas spp. being the most prevalent organism. The most prevalent multiple antibiotic resistance phenotype observed was KF-AP-C-E-OT-K-TM-A. All organisms tested were resistant to erythromycin, trimethoprim, and amoxicillin. All isolates were susceptible to ciprofloxacin and faecal coliforms and Pseudomonas spp. to neomycin and streptomycin. Cluster analysis based on inhibition zone diameter data suggests that the isolates had similar chemical exposure histories. Isolates were identified using gyrB, toxA, ecfX, aerA, and hylH gene fragments and gyrB, ecfX, and hylH fragments were amplified. These results demonstrate that (i) the drinking water from Mafikeng contains various bacterial species and at times faecal and total coliforms. (ii) The various bacteria are resistant to various classes of antibiotics. PMID:25105027

Molecular survey of occurrence and quantity of Legionella spp., Mycobacterium spp., Pseudomonas aeruginosa and amoeba hosts in municipal drinking water storage tank sediments.

PubMed

Lu, J; Struewing, I; Yelton, S; Ashbolt, N

2015-07-01

To examine the occurrence and quantity of potential pathogens and an indicator of microbial contamination in the sediments of municipal drinking water storage tanks (MDWSTs), given the absence of such data across the United States. Sediment samples (87 MDWST) from eighteen locations across ten states of the United States were collected and assayed by qPCR for a range of potential enteric and opportunistic microbial pathogens and a sewage-associated Bacteroides marker. Potential opportunistic pathogens dominated, with the highest detection of occurrence (per cent positive detection; average cell equivalence (CE)) being Mycobacterium spp. (88·9%; 6·7 ± 8·5 × 10(4) CE g(-1) ), followed by Legionella spp. (66·7%; 5·2 ± 5·9 × 10(3) CE g(-1) ), Pseudomonas aeruginosa (22·2%; 250 ± 880 CE g(-1) ) and Acanthamoeba spp. (38·9%; 53 ± 70 CE g(-1) ), with no detected Naegleria fowleri. Most enteric pathogens (Campylobacter jejuni, Escherichia coli 0157:H7, Salmonella enterica, Cryptosporidium parvum and Giardia duodenalis) were not detected, except for a trace signal for Campylobacter spp. There was significant correlation between the qPCR signals of Legionella spp. and Acanthamoeba spp. (R(2) = 0·61, n = 87, P = 0·0001). Diverse Legionella spp. including Leg. pneumophila, Leg. pneumophila sg1 and Leg. anisa were identified, each of which might cause legionellosis. These results imply that potential opportunistic pathogens are common within MDWST sediments and could act as a source of microbial contamination, but need downstream growth to be of potential concern. The results imply that opportunistic pathogen risks may need to be managed by regular tank cleaning or other management practices. 2015 The Society for Applied Microbiology.

Phenotypic characterization and colistin susceptibilities of carbapenem-resistant of Pseudomonas aeruginosa and Acinetobacter spp.

PubMed

Mohanty, Srujana; Maurya, Vijeta; Gaind, Rajni; Deb, Monorama

2013-11-15

Pseudomonas aeruginosa and Acinetobcter spp. are important nosocomial pathogens and carbapenem resistance is an emerging threat. Therapeutic options for infections with these isolates include colistin. This study was conducted to determine the prevalence of carbapenem resistance in P. aeruginosa and Acinetobacter spp. bloodstream isolates, phenotypically characterize the resistance mechanisms and evaluate the in vitro activity of colistin. Consecutive 145 (95 P.aeruginosa and 50 Acinetobacter spp.) non-repeat isolates were included. Antibiotic susceptibility testing was performed per CLSI guidelines. MIC for carbapenems and colistin was performed using Etest. Isolates showing reduced susceptibility or resistance to the carbapenems were tested for metallo-β-lactamase (MBL) production using imipenem-EDTA combined disk and MBL Etest. Carbapenem resistance was observed in 40% P. aeruginosa and 66.0% Acinetobacter spp. Carbapenem-resistant (CA-R) isolates were significantly (p <0.05) more frequently resistant to the other antibiotics than carbapenem-susceptible isolates. Approximately half of the CA-R strains were multidrug-resistant, and 3.1-5.5% were resistant to all antibiotics tested. MBL was found in 76.3% and 69.7% of the P. aeruginosa and Acinetobacter spp., respectively. Colistin resistance was observed in three (6.0%) Acinetobacter isolates and eight (8.4%) P. aeruginosa. MIC50 for carbapenems were two to four times higher for MBL-positive compared to MBL-negative isolates, but no difference was seen in MIC for colistin. Carbapenem resistance was observed to be mediated by MBL in a considerable number of isolates. Colistin is an alternative for infections caused by CA-R isolates; however, MIC testing should be performed whenever clinical use of colistin is considered.

Pseudomonas screening assay

NASA Technical Reports Server (NTRS)

Margalit, Ruth (Inventor)

1993-01-01

A method for the detection of Pseudomonas bacteria is described where an Azurin-specific antibody is employed for detecting the presence of Azurin in a test sample. The detection of the presence of Azurin in the sample is a conclusive indicator of the presence of the Pseudomonas bacteria since the Azurin protein is a specific marker for this bacterial strain.

Detection of Different β-Lactamases and their Co-existence by Using Various Discs Combination Methods in Clinical Isolates of Enterobacteriaceae and Pseudomonas spp.

PubMed Central

Rawat, Vinita; Singhai, Monil; Verma, Pankaj Kumar

2013-01-01

Background: Resistance to broad spectrum beta-lactams mediated by extended spectrum β-lactamase (ESBL), AmpC, and metallobetalactamase (MBLs) enzymes are an increasing problem worldwide. The study was aimed to detect occurrence rate and to evaluate different substrates and inhibitors by disc combination method for detecting varying degree of β-lactamase enzymes and their co-production. Materials and Methods: A disc panel containing imipenem (IMP), IMP/EDTA, ceftazidime (CA), ceftazidime-tazobactum (CAT), CAT/cloxacillin (CLOX), ceftazidime-clavulanic acid (CAC), CAC/CLOX, cefoxitin (CN), and CN/CLOX in a single plate was used to detect presence of ESBLs, AmpC, and MBLs and/or their co-existence in 184 consecutive, nonrepetitive, clinical isolates of Enterobacteriace (n = 96) and Pseudomonas spp. (n = 88) from pus samples of hospitalized patients, resistant to 3rd generation cephalosporins. Results: Out of a total of 96 clinical isolates of Enterobacteriaceae, 18.7, 20.8, and 27% were pure ESBL, AmpC, and MBL producers, respectively. ESBL and AmpC were co-produced by 25% isolates. Among 88 Pseudomonas spp. 38.6, 13, and 6% were pure MBL, ESBL, and AmpC producers, respectively. ESBL/AmpC and MBL/AmpC co-production was seen in 20% and 18% isolates, respectively. Among ESBL and AmpC co-producers, CA/CAC/CLOX disc combination (DC) missed 7 of the 24 ESBL producers in Enterobacteriace and 4 of the 18 ESBL in Pseudomonas spp., which were detected by CA/CAT/CLOX DC. No mechanism was detected among 8.3% Enterobacteriaceae and 2.3% Pseudomonas isolates. Conclusion: Diagnostic problems posed by co-existence of different classes of β-lactamases in a single isolate could be solved by disc combination method by using simple panel of discs containing CA, CAT, CAT/CLOX, IMP, and IMP/EDTA. PMID:24014963

Polyhexamethylene guanidine hydrochloride shows bactericidal advantages over chlorhexidine digluconate against ESKAPE bacteria.

PubMed

Zhou, Zhongxin; Wei, Dafu; Lu, Yanhua

2015-01-01

More information regarding the bactericidal properties of polyhexamethylene guanidine hydrochloride (PHMG) against clinically important antibiotic-resistant ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens needs to be provided for its uses in infection control. The bactericidal properties of PHMG and chlorhexidine digluconate (CHG) were compared based on their minimum inhibitory concentrations (MICs), minimum bactericidal concentrations, and time-course-killing curves against clinically important antibiotic-susceptible and antibiotic-resistant ESKAPE pathogens. Results showed that PHMG exhibited significantly higher bactericidal activities against methicillin-resistant Staphylococcus aureus, carbapenem-resistant Klebsiella pneumoniae, and ceftazidime-resistant Enterobacter spp. than CHG. A slight bactericidal advantage over CHG was obtained against vancomycin-resistant Enterococcus faecium, ciprofloxacin- and levofloxacin-resistant Acinetobacter spp., and multidrug-resistant Pseudomonas aeruginosa. In previous reports, PHMG had higher antimicrobial activity against almost all tested Gram-negative bacteria and several Gram-positive bacteria than CHG using MIC test. These studies support the further development of covalently bound PHMG in sterile-surface materials and the incorporation of PHMG in novel disinfectant formulas. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

Binary combination of epsilon-poly-L-lysine and isoeugenol affect progression of spoilage microbiota in fresh turkey meat, and delay onset of spoilage in Pseudomonas putida challenged meat.

PubMed

Hyldgaard, Morten; Meyer, Rikke L; Peng, Min; Hibberd, Ashley A; Fischer, Jana; Sigmundsson, Arnar; Mygind, Tina

2015-12-23

Proliferation of microbial population on fresh poultry meat over time elicits spoilage when reaching unacceptable levels, during which process slime production, microorganism colony formation, negative organoleptic impact and meat structure change are observed. Spoilage organisms in raw meat, especially Gram-negative bacteria can be difficult to combat due to their cell wall composition. In this study, the natural antimicrobial agents ε-poly-L-lysine (ε-PL) and isoeugenol were tested individually and in combinations for their activities against a selection of Gram-negative strains in vitro. All combinations resulted in additive interactions between ε-PL and isoeugenol towards the bacteria tested. The killing efficiency of different ratios of the two antimicrobial agents was further evaluated in vitro against Pseudomonas putida. Subsequently, the most efficient ratio was applied to a raw turkey meat model system which was incubated for 96 h at spoilage temperature. Half of the samples were challenged with P. putida, and the bacterial load and microbial community composition was followed over time. CFU counts revealed that the antimicrobial blend was able to lower the amount of viable Pseudomonas spp. by one log compared to untreated samples of challenged turkey meat, while the single compounds had no effect on the population. However, the compounds had no effect on Pseudomonas spp. CFU in unchallenged meat. Next-generation sequencing offered culture-independent insight into population diversity and changes in microbial composition of the meat during spoilage and in response to antimicrobial treatment. Spoilage of unchallenged turkey meat resulted in decreasing species diversity over time, regardless of whether the samples received antimicrobial treatment. The microbiota composition of untreated unchallenged meat progressed from a Pseudomonas spp. to a Pseudomonas spp., Photobacterium spp., and Brochothrix thermosphacta dominated food matrix on the expense of low

Non-susceptibility trends among Pseudomonas aeruginosa and other non-fermentative Gram-negative bacteria from bacteraemias in the UK and Ireland, 2001-06.

PubMed

Livermore, David M; Hope, Russell; Brick, Geraldine; Lillie, Mark; Reynolds, Rosy

2008-11-01

Pseudomonas and Acinetobacter spp. are important opportunists, notorious for resistance. Pseudomonas spp. are collected in the British Society for Antimicrobial Chemotherapy (BSAC) bacteraemia surveillance, with Acinetobacter spp. and Stenotrophomonas maltophilia well represented in the 'other Gram-negatives' group. Data for collected isolates were reviewed together with LabBase bacteraemia reports to the Health Protection Agency (HPA). Isolates with unusual resistances were subjected to molecular investigation. From 2001 to 2006, the BSAC surveillance collected 1226 Pseudomonas aeruginosa, 240 Acinetobacter spp.-125 of them Acinetobacter calcoaceticus/baumannii (Acb) complex-and 165 S. maltophilia. Among P. aeruginosa, non-susceptibility rates to beta-lactams and gentamicin fluctuated, without trend, below 10%; those to ciprofloxacin ranged from 16% to 22%. One P. aeruginosa isolate from 2001 had VIM-2 metallo-beta-lactamase. For Acb, the BSAC data indicated frequent non-susceptibility, except to imipenem, where only five non-susceptible isolates were collected, all after 2003, four of them belonging to the OXA-23 clone 1 lineage which is prevalent in Southeast England. Reports to the HPA indicated rising imipenem non-susceptibility in Acb (P < 0.0001). Co-trimoxazole retained near-universal activity against S. maltophilia. Among new antibiotics, doripenem MICs were /=16 mg/L for Acb OXA-23 clone 1. Ceftobiprole had higher MICs than ceftazidime for P. aeruginosa, but 81% of the isolates were inhibited at

Differentiation of farmed and wild turbot (Psetta maxima): proximate chemical composition, fatty acid profile, trace minerals and antimicrobial resistance of contaminant bacteria.

PubMed

Martínez, B; Miranda, J M; Nebot, C; Rodriguez, J L; Cepeda, A; Franco, C M

2010-10-01

The proximate, cholesterol, fatty acid and trace mineral compositions in the flesh of farmed and wild turbot (Psetta maxima) were evaluated. Additionally, the potential influence of the use of antimicrobial agents in the bacteria carried by farmed turbot was investigated. For this purpose, a total of 144 Pseudomonas spp. and 127 Aeromonas spp. were isolated and tested for their susceptibility to 12 antimicrobials by a disk diffusion method. Farmed turbot contained higher fat, cholesterol and calories as well as lower moisture content than its wild counterpart. The fatty acid profile of farmed turbot included higher levels of myristic, pentadecanoic, palmitoleic, gadoleic, cetoleic, linoleic, linolenic, stearidonic, eicosadienoic and eicosapentaenoic acids, and lower levels of stearic, arachidonic, docosapentaenoic and docosahexaenoic acids than its wild counterpart. The proportions of polyunsaturated fatty acids and n-3/n-6 ratios were higher in wild turbot than in farmed turbot. With respect to trace minerals, no toxic levels were found, and higher amounts of Cd, Co, Cu, Fe, Mn, Pb and Zn, as well as lower amounts of Cr, were found in farmed turbot relative to wild turbot. The antimicrobial resistance of Pseudomonas spp. and Aeromonas spp. were quite similar, with only the trimethoprim-sulfamethoxazole resistance of Aeromonas spp. isolated from farmed turbot being higher than those isolated from wild turbot. In the case of ampicillin, Pseudomonas spp. isolated from wild turbot showed higher resistance levels than those of their counterparts isolated from farmed turbot. In conclusion, the nutritional parameters of wild turbot are more adequate with respect to nutritional recommendations, while no differences were observed in food safety derived from trace mineral concentrations or the antimicrobial resistance of bacteria isolated from wild and farmed turbot.

Numerical taxonomy and ecology of petroleum-degrading bacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Austin, B.; Calomiris, J.J.; Walker, J.D.

1977-07-01

A total of 99 strains of petroleum-degrading bacteria isolated from Chesapeake Bay water and sediment were identified by using numerical taxonomy procedures. The isolates, together with 33 reference cultures, were examined for 48 biochemical, cultural, morphological, and physiological characters. The data were analyzed by computer, using both the simple matching and the Jaccard coefficients. Clustering was achieved by the unweighted average linkage method. From the sorted similarity matrix and dendrogram, 14 phenetic groups, comprising 85 of the petroleum-degrading bacteria, were defined at the 80 to 85% similarity level. These groups were identified as actinomycetes (mycelial forms, four clusters), coryneforms, Enterobacteriaceae,more » Klebsiella aerogenes, Micrococcus spp. (two clusters), Nocardia species (two clusters), Pseudomonas spp. (two clusters), and Sphaerotilus natans. It is concluded that the degradation of petroleum is accomplished by a diverse range of bacterial taxa, some of which were isolated only at given sampling stations and, more specifically, from sediment collected at a given station.« less

Numerical taxonomy and ecology of petroleum-degrading bacteria.

PubMed Central

Austin, B; Calomiris, J J; Walker, J D; Colwell, R R

1977-01-01

A total of 99 strains of petroleum-degrading bacteria isolated from Chesapeake Bay water and sediment were identified by using numerical taxonomy procedures. The isolates, together with 33 reference cultures, were examined for 48 biochemical, cultural, morphological, and physiological characters. The data were analyzed by computer, using both the simple matching and the Jaccard coefficients. Clustering was achieved by the unweighted average linkage method. From the sorted similarity matrix and dendrogram, 14 phenetic groups, comprising 85 of the petroleum-degrading bacteria, were defined at the 80 to 85% similarity level. These groups were identified as actinomycetes (mycelial forms, four clusters), coryneforms, Enterobacteriaceae, Klebsiella aerogenes, Micrococcus spp. (two clusters), Nocardia species (two clusters), Pseudomonas spp. (two clusters), and Sphaerotilus natans. It is concluded that the degradation of petroleum is accomplished by a diverse range of bacterial taxa, some of which were isolated only at given sampling stations and, more specifically, from sediment collected at a given station. PMID:889329

Assessment of pathogenic bacteria in water and sediment from a water reservoir under tropical conditions (Lake Ma Vallée), Kinshasa Democratic Republic of Congo.

PubMed

Mwanamoki, Paola M; Devarajan, Naresh; Thevenon, Florian; Atibu, Emmanuel K; Tshibanda, Joseph B; Ngelinkoto, Patience; Mpiana, Pius T; Prabakar, Kandasamy; Mubedi, Josué I; Kabele, Christophe G; Wildi, Walter; Poté, John

2014-10-01

This study was conducted to assess potential human health risks presented by pathogenic bacteria in a protected multi-use lake-reservoir (Lake Ma Vallée) located in west of Kinshasa, Democratic Republic of Congo (DRC). Water and surface sediments from several points of the Lake were collected during summer. Microbial analysis was performed for Escherichia coli, Enterococcus (ENT), Pseudomonas species and heterotrophic plate counts. PCR amplification was performed for the confirmation of E. coli, ENT, Pseudomonas spp. and Pseudomonas aeruginosa isolated from samples. The results reveal low concentration of bacteria in water column of the lake, the bacterial quantification results observed in this study for the water column were below the recommended limits, according to WHO and the European Directive 2006/7/CE, for bathing water. However, high concentration of bacteria was observed in the sediment samples; the values of 2.65 × 10(3), 6.35 × 10(3), 3.27 × 10(3) and 3.60 × 10(8) CFU g(-1) of dry sediment for E. coli, ENT, Pseudomonas spp. and heterotrophic plate counts, respectively. The results of this study indicate that sediments of the Lake Ma Vallée can constitute a reservoir of pathogenic microorganisms which can persist in the lake. Possible resuspension of faecal indicator bacteria and pathogens would affect water quality and may increase health risks to the population during recreational activities. Our results indicate that the microbial sediment analysis provides complementary and important information for assessing sanitary quality of surface water under tropical conditions.

High quality draft genome sequences of Pseudomonas fulva DSM 17717 T, Pseudomonas parafulva DSM 17004 T and Pseudomonas cremoricolorata DSM 17059 T type strains

DOE PAGES

Peña, Arantxa; Busquets, Antonio; Gomila, Margarita; ...

2016-09-01

Pseudomonas has the highest number of species out of any genus of Gram-negative bacteria and is phylogenetically divided into several groups. The Pseudomonas putida phylogenetic branch includes at least 13 species of environmental and industrial interest, plant-associated bacteria, insect pathogens, and even some members that have been found in clinical specimens. In the context of the Genomic Encyclopedia of Bacteria and Archaea project, we present the permanent, high-quality draft genomes of the type strains of 3 taxonomically and ecologically closely related species in the Pseudomonas putida phylogenetic branch: Pseudomonas fulva DSM 17717 T, Pseudomonas parafulva DSM 17004 T and Pseudomonasmore » cremoricolorata DSM 17059T. All three genomes are comparable in size (4.6-4.9Mb), with 4,119-4,459 protein-coding genes. Average nucleotide identity based on BLAST comparisons and digital genome-to-genome distance calculations are in good agreement with experimental DNA-DNA hybridization results. The genome sequences presented here will be very helpful in elucidating the taxonomy, phylogeny and evolution of the Pseudomonas putida species complex.« less

High quality draft genome sequences of Pseudomonas fulva DSM 17717 T, Pseudomonas parafulva DSM 17004 T and Pseudomonas cremoricolorata DSM 17059 T type strains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peña, Arantxa; Busquets, Antonio; Gomila, Margarita

Pseudomonas has the highest number of species out of any genus of Gram-negative bacteria and is phylogenetically divided into several groups. The Pseudomonas putida phylogenetic branch includes at least 13 species of environmental and industrial interest, plant-associated bacteria, insect pathogens, and even some members that have been found in clinical specimens. In the context of the Genomic Encyclopedia of Bacteria and Archaea project, we present the permanent, high-quality draft genomes of the type strains of 3 taxonomically and ecologically closely related species in the Pseudomonas putida phylogenetic branch: Pseudomonas fulva DSM 17717 T, Pseudomonas parafulva DSM 17004 T and Pseudomonasmore » cremoricolorata DSM 17059T. All three genomes are comparable in size (4.6-4.9Mb), with 4,119-4,459 protein-coding genes. Average nucleotide identity based on BLAST comparisons and digital genome-to-genome distance calculations are in good agreement with experimental DNA-DNA hybridization results. The genome sequences presented here will be very helpful in elucidating the taxonomy, phylogeny and evolution of the Pseudomonas putida species complex.« less

Distribution, genetic diversity and antibiotic resistance of clinically important bacteria from the environment of a tertiary hospital.

PubMed

Phoon, Hannah Y P; Hussin, Hazilawati; Hussain, Baizurah Mohd; Lim, Shu Yong; Woon, Jia Jie; Er, Yi Xian; Thong, Kwai Lin

2018-03-11

Hospital environments are potential reservoirs of bacteria associated with nosocomial infections. Here, we determined the distribution of cultivable environmental bacteria of clinical importance from a Malaysian tertiary hospital and to investigate their resistotypes and genotypes. Swab and fluid samples (n=358) from healthcare workers' hands, frequently touched surfaces, medical equipment, patients' immediate surroundings, ward sinks and toilets and solutions or fluids of 12 selected wards were collected. Biochemical tests, PCR and 16S rRNA sequencing were used for identification after isolation from CHROMagar TM Orientation medium. Clinically important bacteria such as Enterococcus spp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter spp., Pseudomonas aeruginosa, and Enterobacter spp. were further characterised by disk diffusion method and REP-PCR. The 32 Gram negative and 21 Gram positive bacteria species identified were widely distributed in the hospital environment. Staphylococci were predominant followed by Bacillus spp., and P. aeruginosa. Frequently touched surfaces, medical equipment and ward sinks and toilets were the top three sources of bacterial species. Nine S. aureus, four Acinetobacter spp., one K. pneumoniae, and one Enterobacter spp., were multidrug resistant (MDR). The ESKAPE organisms were genetically diverse and widely dispersed across the hospital wards. An MDR MRSA clone was detected in a surgical ward isolation room. The large variety of cultivable, clinically important bacteria, especially the genetically related MDR S. aureus, K. pneumoniae, Acinetobacter spp., and Enterobacter spp. from various sampling sites indicated that the surfaces and fomites in the hospital were potential exogenous sources of nosocomial infections in the hospital. Copyright © 2018 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Endophytic colonization of olive roots by the biocontrol strain Pseudomonas fluorescens PICF7.

PubMed

Prieto, Pilar; Mercado-Blanco, Jesús

2008-05-01

Confocal microscopy combined with three-dimensional olive root tissue sectioning was used to provide evidence of the endophytic behaviour of Pseudomonas fluorescens PICF7, an effective biocontrol strain against Verticillium wilt of olive. Two derivatives of the green fluorescent protein (GFP), the enhanced green and the red fluorescent proteins, have been used to visualize simultaneously two differently fluorescently tagged populations of P. fluorescens PICF7 within olive root tissues at the single cell level. The time-course of colonization events of olive roots cv. Arbequina by strain PICF7 and the localization of tagged bacteria within olive root tissues are described. First, bacteria rapidly colonized root surfaces and were predominantly found in the differentiation zone. Thereafter, microscopy observations showed that PICF7-tagged populations eventually disappeared from the root surface, and increasingly colonized inner root tissues. Localized and limited endophytic colonization by the introduced bacteria was observed over time. Fluorescent-tagged bacteria were always visualized in the intercellular spaces of the cortex region, and no colonization of the root xylem vessels was detected at any time. To the best of our knowledge, this is the first time this approach has been used to demonstrate endophytism of a biocontrol Pseudomonas spp. strain in a woody host such as olive using a nongnotobiotic system.

Biphenyl-metabolizing bacteria in the rhizosphere of horseradish and bulk soil contaminated by polychlorinated biphenyls as revealed by stable isotope probing.

PubMed

Uhlik, Ondrej; Jecna, Katerina; Mackova, Martina; Vlcek, Cestmir; Hroudova, Miluse; Demnerova, Katerina; Paces, Vaclav; Macek, Tomas

2009-10-01

DNA-based stable isotope probing in combination with terminal restriction fragment length polymorphism was used in order to identify members of the microbial community that metabolize biphenyl in the rhizosphere of horseradish (Armoracia rusticana) cultivated in soil contaminated with polychlorinated biphenyls (PCBs) compared to members of the microbial community in initial, uncultivated bulk soil. On the basis of early and recurrent detection of their 16S rRNA genes in clone libraries constructed from [(13)C]DNA, Hydrogenophaga spp. appeared to dominate biphenyl catabolism in the horseradish rhizosphere soil, whereas Paenibacillus spp. were the predominant biphenyl-utilizing bacteria in the initial bulk soil. Other bacteria found to derive carbon from biphenyl in this nutrient-amended microcosm-based study belonged mostly to the class Betaproteobacteria and were identified as Achromobacter spp., Variovorax spp., Methylovorus spp., or Methylophilus spp. Some bacteria that were unclassified at the genus level were also detected, and these bacteria may be members of undescribed genera. The deduced amino acid sequences of the biphenyl dioxygenase alpha subunits (BphA) from bacteria that incorporated [(13)C]into DNA in 3-day incubations of the soils with [(13)C]biphenyl are almost identical to that of Pseudomonas alcaligenes B-357. This suggests that the spectrum of the PCB congeners that can be degraded by these enzymes may be similar to that of strain B-357. These results demonstrate that altering the soil environment can result in the participation of different bacteria in the metabolism of biphenyl.

Control of spoiler Pseudomonas spp. on fresh cut vegetables by neutral electrolyzed water.

PubMed

Pinto, Loris; Ippolito, Antonio; Baruzzi, Federico

2015-09-01

In the present study, we evaluated the antimicrobial activity of neutral electrolyzed water (NEW) against 14 strains of spoilage Pseudomonas of fresh cut vegetables under cold storage. The NEW, produced from solutions of potassium and sodium chloride, and sodium bicarbonate developed up to 4000 mg/L of free chlorine, depending on the salt and relative concentration used. The antimicrobial effect of the NEW was evaluated against different bacterial strains at 10(5) cells/ml, with different combinations of free chlorine concentration/contact time; all concentrations above 100 mg/L, regardless of the salt used, were found to be bactericidal already after 2 min. When catalogna chicory and lettuce leaves were dipped for 5 min in diluted NEW, microbial loads of mesophilic bacteria and Enterobacteriaceae were reduced on average of 1.7 log cfu/g. In addition, when lettuce leaves were dipped in a cellular suspension of the spoiler Pseudomonas chicorii I3C strain, diluted NEW was able to reduce Pseudomonas population of about 1.0 log cfu/g. Thanks to its high antimicrobial activity against spoilage microorganisms, and low cost of operation, the application of cycles of electrolysis to the washing water looks as an effective tool in controlling fresh cut vegetable microbial spoilage contamination occurring during washing steps. Copyright © 2015 Elsevier Ltd. All rights reserved.

Various effects of fluorescent bacteria of the genus Pseudomonas containing ACC deaminase on wheat seedling growth.

PubMed

Magnucka, Elżbieta G; Pietr, Stanisław J

2015-12-01

The study evaluates the effect of rhizobacteria having 1-aminocyclopropane-1-carboxylate deaminase (ACCd) on the development of wheat seedlings. This enzyme has been proposed to play a key role in microbe-plant association. Three fluorescent pseudomonads containing this deaminase were selected from 70 strains of pseudomonads isolated from rhizosphere of wheat (Triticum aestivum L.) and rape (Brassica napus L.). These bacteria, varied significantly in the ability to both biosynthesize auxins and hydrolyze ACC. Among them, Pseudomonas brassicacearum subsp. brassicacearum strain RZ310 presented the highest activities of ACC deaminase during 96h of growth in liquid Dworkin and Foster (DF) salt medium. Additionally, this rape rhizosphere strain did not produce indoles. Two other isolates, Pseudomonas sp. PO283 and Pseudomonas sp. PO366, secreted auxins only in the presence of their precursor. Phylogenetic analysis of the 16S rRNA gene and four other protein-encoding genes indicated that these wheat rhizosphere isolates belonged to the fluorescent Pseudomonas group. Moreover, the effects of these strains on wheat seedling growth under in vitro conditions were markedly dependent on both their cell suspensions used to grain inoculation and nutrient conditions. Strains tested had beneficial influence on wheat seedlings mainly at low cell densities. In addition, access to nutrients markedly changed bacteria action on cereal growth. Their presence generally favored the positive effects of pseudomonads on length and the estimated biomasses of wheat coleoptiles. Despite these general rules, impacts of each isolate on the growth parameters of cereal seedlings were unique. Copyright © 2015 Elsevier GmbH. All rights reserved.

Microbial dynamics in mixed culture biofilms of bacteria surviving sanitation of conveyor belts in salmon-processing plants.

PubMed

Langsrud, S; Moen, B; Møretrø, T; Løype, M; Heir, E

2016-02-01

The microbiota surviving sanitation of salmon-processing conveyor belts was identified and its growth dynamics further investigated in a model mimicking processing surfaces in such plants. A diverse microbiota dominated by Gram-negative bacteria was isolated after regular sanitation in three salmon processing plants. A cocktail of 14 bacterial isolates representing all genera isolated from conveyor belts (Listeria, Pseudomonas, Stenotrophomonas, Brochothrix, Serratia, Acinetobacter, Rhodococcus and Chryseobacterium) formed stable biofilms on steel coupons (12°C, salmon broth) of about 10(9) CFU cm(-2) after 2 days. High-throughput sequencing showed that Listeria monocytogenes represented 0·1-0·01% of the biofilm population and that Pseudomonas spp dominated. Interestingly, both Brochothrix sp. and a Pseudomonas sp. dominated in the surrounding suspension. The microbiota surviving sanitation is dominated by Pseudomonas spp. The background microbiota in biofilms inhibit, but do not eliminate L. monocytogenes. The results highlights that sanitation procedures have to been improved in the salmon-processing industry, as high numbers of a diverse microbiota survived practical sanitation. High-throughput sequencing enables strain level studies of population dynamics in biofilm. © 2015 The Society for Applied Microbiology.

Bovine esophageal and glossal ulceration associated with Pseudomonas aeruginosa and Fusobacterium spp.in a 10-month-old Holstein heifer.

PubMed

Tosaki, Kaori; Kojima, Hirokazu; Akama, Shunsuke; Ootake, Yoshihiro; Inoue, Kyoichi; Katsuda, Ken; Shibahara, Tomoyuki

2018-05-25

An underweight 10-month-old Holstein heifer presented with anorexia and ananastasia and was euthanized. Postmortem examination revealed extensive ulceration in the esophagus, tongue, and omasum. Histopathological examination revealed severe necrotic esophagitis, glossitis, and omasitis. Many Gram-negative bacilli were detected throughout the necrotic area in the digestive tract; these were identified as Pseudomonas aeruginosa on the basis of isolation tests, molecular examinations, and immunohistochemistry. Gram-negative long filamentous organisms in the superficial layers of the necrotic lesions reacted positively with antibodies against Fusobacteriumnecrophorum subsp. necrophorum. Thus, the necrotic lesions were confirmed to be associated with P. aeruginosa and Fusobacterium spp. This is the first detection of P. aeruginosa in bovine esophageal and glossal ulcers associated with Fusobacterium spp.

Pyogranulomatous panniculitis in ferrets (Mustela putorius furo) with intralesional demonstration of Pseudomonas luteola.

PubMed

Baum, B; Richter, B; Reifinger, M; Klang, A; Finnberg, C; Loncaric, I; Spergser, J; Eisenberg, T; Künzel, F; Preis, S; Pantchev, N; Rütgen, B; Guija de Arespacochaga, A; Hewicker-Trautwein, M

2015-01-01

One ferret (Mustela putorius furo) from Finland and two ferrets from Austria, aged 1-4.5 years and of both genders, were presented with pyogranulomatous subcutaneous inflammation affecting the inguinal, preputial and femoral regions, respectively. Histologically, microorganisms were detected within the lesions. The organisms had a capsule that stained positively by the periodic acid-Schiff reaction. Pseudomonas spp. were cultured from the lesions in two cases. In the third case, electron microscopy revealed a prokaryotic organism surrounded by an electron lucent matrix. 16S rRNA gene sequencing showed highest sequence homology to Pseudomonas luteola in all three cases. In combination with recent reports of pleuropneumonia in ferrets due to P. luteola infection, these cases might indicate a predisposition of ferrets for infection by these bacteria. Copyright © 2015 Elsevier Ltd. All rights reserved.

Rapid differentiation of cocci/mixed bacteria from rods in voided urine culture of women with uncomplicated urinary tract infections.

PubMed

Yang, Chun-Chun; Yang, Stephen Shei-Dei; Hung, Hui-Ching; Chiang, I-Ni; Peng, Chiung-Hui; Chang, Shang-Jen

2017-09-01

To evaluate the ability of laser flow cytometry to predict cocci/mixed growth in the pre-analytical phase of urine specimens. We retrospectively reviewed urine samples from women with uncomplicated urinary tract infections from urologic clinics for study. Urine analyses were performed with laser flow cytometry (UF1000i, Sysmex, Kobe, Japan) and then diagrams were generated (forward scatter vs. fluorescent light scatter). Each specimen (bacteria count >357 BACT/μL) was classified as either cocci bacteria or rods/mixed growth according to the diagrams. Standard urine cultures were performed, and the agreement between cultures and the UF1000i interpretations was analyzed with kappa statistics. Finally, 491 specimens met the criteria for analysis. Among the 376 specimens with single bacteria growth, there were 26 gram-positive cocci (13 Streptococci spp., 7 Staphylococci spp., 6 Enterococci spp.), 1 gram-positive rods (Corynebacterium spp.), and 349 gram-negative rods (273 Escherichia coli, 33 Klebsiella spp., 29 Proteus spp., 6 Citrobacter spp., 4 Enterobacter spp., 3 Pseudomonas spp., and 1 Providencia spp.). There were 115 specimens with two bacteria species or more that were regarded as mixed growth. Agreement of rods or cocci/mixed growth between the laser flow cytometry and urine cultures yielded a kappa value of 0.58. The positive and negative predictive rate of the UF1000i for cocci/mixed growth in voided urine culture was 81.8% and 84.7%, respectively. Through laser flow cytometry, we can predict growth of cocci/mixed growth in the pre-analytical phase of urine culture, thus avoiding unnecessary urine culture and waiting time. © 2016 Wiley Periodicals, Inc.

Comparative genomic, proteomic and exoproteomic analyses of three Pseudomonas strains reveals novel insights into the phosphorus scavenging capabilities of soil bacteria

PubMed Central

Murphy, Andrew R. J.; Scanlan, David J.; Bending, Gary D.; Jones, Alexandra M. E.; Moore, Jonathan D.; Goodall, Andrew; Hammond, John P.; Wellington, Elizabeth M. H.

2016-01-01

Summary Bacteria that inhabit the rhizosphere of agricultural crops can have a beneficial effect on crop growth. One such mechanism is the microbial‐driven solubilization and remineralization of complex forms of phosphorus (P). It is known that bacteria secrete various phosphatases in response to low P conditions. However, our understanding of their global proteomic response to P stress is limited. Here, exoproteomic analysis of Pseudomonas putida BIRD‐1 (BIRD‐1), Pseudomonas fluorescens SBW25 and Pseudomonas stutzeri DSM4166 was performed in unison with whole‐cell proteomic analysis of BIRD‐1 grown under phosphate (Pi) replete and Pi deplete conditions. Comparative exoproteomics revealed marked heterogeneity in the exoproteomes of each Pseudomonas strain in response to Pi depletion. In addition to well‐characterized members of the PHO regulon such as alkaline phosphatases, several proteins, previously not associated with the response to Pi depletion, were also identified. These included putative nucleases, phosphotriesterases, putative phosphonate transporters and outer membrane proteins. Moreover, in BIRD‐1, mutagenesis of the master regulator, phoBR, led us to confirm the addition of several novel PHO‐dependent proteins. Our data expands knowledge of the Pseudomonas PHO regulon, including species that are frequently used as bioinoculants, opening up the potential for more efficient and complete use of soil complexed P. PMID:27233093

Quantitative analyses of the bacterial microbiota of rearing environment, tilapia and common carp cultured in earthen ponds and inhibitory activity of its lactic acid bacteria on fish spoilage and pathogenic bacteria.

PubMed

Kaktcham, Pierre Marie; Temgoua, Jules-Bocamdé; Ngoufack Zambou, François; Diaz-Ruiz, Gloria; Wacher, Carmen; Pérez-Chabela, María de Lourdes

2017-02-01

The present study aimed to evaluate the bacterial load of water, Nile Tilapia and common Carp intestines from earthen ponds, isolate lactic acid bacteria (LAB) and assess their antimicrobial activity against fish spoilage and pathogenic bacteria. Following enumeration and isolation of microorganisms the antimicrobial activity of the LAB isolates was evaluated. Taxonomic identification of selected antagonistic LAB strains was assessed, followed by partial characterisation of their antimicrobial metabolites. Results showed that high counts (>4 log c.f.u ml -1 or 8 log c.f.u g -1 ) of total aerobic bacteria were recorded in pond waters and fish intestines. The microbiota were also found to be dominated by Salmonella spp., Vibrio spp., Staphylococcus spp. and Escherichia coli. LAB isolates (5.60%) exhibited potent direct and extracellular antimicrobial activity against the host-derived and non host-derived spoilage and pathogenic bacteria. These antagonistic isolates were identified and Lactococcus lactis subsp. lactis was found as the predominant (42.85%) specie. The strains displayed the ability to produce lactic, acetic, butyric, propionic and valeric acids. Bacteriocin-like inhibitory substances with activity against Gram-positive and Gram-negative (Vibrio spp. and Pseudomonas aeruginosa) bacteria were produced by three L. lactis subsp. lactis strains. In this study, the LAB from the microbiota of fish and pond water showed potent antimicrobial activity against fish spoilage or pathogenic bacteria from the same host or ecological niche. The studied Cameroonian aquatic niche is an ideal source of antagonistic LAB that could be appropriate as new fish biopreservatives or disease control agents in aquaculture under tropical conditions in particular or worldwide in general.

Detection of relapsing fever Borrelia spp., Bartonella spp. and Anaplasmataceae bacteria in argasid ticks in Algeria.

PubMed

Lafri, Ismail; El Hamzaoui, Basma; Bitam, Idir; Leulmi, Hamza; Lalout, Reda; Mediannikov, Oleg; Chergui, Mohamed; Karakellah, Mohamed; Raoult, Didier; Parola, Philippe

2017-11-01

Argasid ticks (soft ticks) are blood-feeding arthropods that can parasitize rodents, birds, humans, livestock and companion animals. Ticks of the Ornithodoros genus are known to be vectors of relapsing fever borreliosis in humans. In Algeria, little is known about relapsing fever borreliosis and other bacterial pathogens transmitted by argasid ticks. Between May 2013 and October 2015, we investigated the presence of soft ticks in 20 rodent burrows, 10 yellow-legged gull (Larus michahellis) nests and animal shelters in six locations in two different bioclimatic zones in Algeria. Six species of argasid ticks were identified morphologically and through 16S rRNA gene sequencing. The presence and prevalence of Borrelia spp., Bartonella spp., Rickettsia spp. and Anaplasmataceae was assessed by qPCR template assays in each specimen. All qPCR-positive samples were confirmed by standard PCR, followed by sequencing the amplified fragments. Two Borrelia species were identified: Borrelia hispanica in Ornithodoros occidentalis in Mostaganem, and Borrelia cf. turicatae in Carios capensis in Algiers. One new Bartonella genotype and one new Anaplasmataceae genotype were also identified in Argas persicus. The present study highlights the presence of relapsing fever borreliosis agents, although this disease is rarely diagnosed in Algeria. Other bacteria of unknown pathogenicity detected in argasid ticks which may bite humans deserve further investigation.

Biphenyl-Metabolizing Bacteria in the Rhizosphere of Horseradish and Bulk Soil Contaminated by Polychlorinated Biphenyls as Revealed by Stable Isotope Probing▿ †

PubMed Central

Uhlik, Ondrej; Jecna, Katerina; Mackova, Martina; Vlcek, Cestmir; Hroudova, Miluse; Demnerova, Katerina; Paces, Vaclav; Macek, Tomas

2009-01-01

DNA-based stable isotope probing in combination with terminal restriction fragment length polymorphism was used in order to identify members of the microbial community that metabolize biphenyl in the rhizosphere of horseradish (Armoracia rusticana) cultivated in soil contaminated with polychlorinated biphenyls (PCBs) compared to members of the microbial community in initial, uncultivated bulk soil. On the basis of early and recurrent detection of their 16S rRNA genes in clone libraries constructed from [13C]DNA, Hydrogenophaga spp. appeared to dominate biphenyl catabolism in the horseradish rhizosphere soil, whereas Paenibacillus spp. were the predominant biphenyl-utilizing bacteria in the initial bulk soil. Other bacteria found to derive carbon from biphenyl in this nutrient-amended microcosm-based study belonged mostly to the class Betaproteobacteria and were identified as Achromobacter spp., Variovorax spp., Methylovorus spp., or Methylophilus spp. Some bacteria that were unclassified at the genus level were also detected, and these bacteria may be members of undescribed genera. The deduced amino acid sequences of the biphenyl dioxygenase α subunits (BphA) from bacteria that incorporated [13C]into DNA in 3-day incubations of the soils with [13C]biphenyl are almost identical to that of Pseudomonas alcaligenes B-357. This suggests that the spectrum of the PCB congeners that can be degraded by these enzymes may be similar to that of strain B-357. These results demonstrate that altering the soil environment can result in the participation of different bacteria in the metabolism of biphenyl. PMID:19700551

Incidence of multidrug-resistant, extensively drug-resistant and pan-drug-resistant bacteria in children hospitalized at Dr. Hasan Sadikin general hospital Bandung Indonesia

NASA Astrophysics Data System (ADS)

Adrizain, R.; Suryaningrat, F.; Alam, A.; Setiabudi, D.

2018-03-01

Antibiotic resistance has become a global issue, with 700,000 deaths attributable to multidrug-resistance (MDR) occurring each year. Centers for Disease Control and Prevention (CDC) show rapidly increasing rates of infection due to antibiotic-resistant bacteria. The aim of the study isto describe the incidence of MDR, extensively drug-resistant (XDR) and pan drug-resistant (PDR) in Enterococcus spp., Staphylococcus aureus, K. pneumonia, Acinetobacter baumanii, P. aeruginosin, and Enterobacter spp. (ESKAPE) pathogens in children admitted to Dr. Hasan Sadikin Hospital. All pediatric patients having blood culture drawn from January 2015 to December 2016 were retrospectively studied. Data include the number of drawn blood culture, number of positive results, type of bacteria, sensitivity pattern. International standard definitions for acquired resistance by ECDC and CDC was used as definitions for MDR, XDR and PDR bacteria. From January 2015 to December 2016, 299 from 2.542 (11.7%) blood culture was positive, with Staphylococcus aureus, Enterococcus spp., Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter spp., respectively 5, 6, 24, 5, 20 with total 60 (20%). The MDR and XDR pathogen found were 47 and 13 patients, respectively.

Modeling the Growth of Epiphytic Bacteria on Kale Treated by Thermosonication Combined with Slightly Acidic Electrolyzed Water and Stored under Dynamic Temperature Conditions.

PubMed

Mansur, Ahmad Rois; Oh, Deog-Hwan

2016-08-01

The growth of epiphytic bacteria (aerobic mesophilic bacteria or Pseudomonas spp.) on kale was modeled isothermally and validated under dynamic storage temperatures. Each bacterial count on kale stored at isothermal conditions (4 to 25 °C) was recorded. The results show that maximum growth rate (μmax ) of both epiphytic bacteria increased and lag time (λ) decreased with increasing temperature (P < 0.05). The maximum population density (Nmax ) of Pseudomonas spp. was significantly greater than that of aerobic mesophilic bacteria, particularly in treated samples and/or at 4 and 10 °C (P < 0.05). The relationship between μmax of both epiphytic bacteria and temperature was linear (R(2) > 0.97), whereas lower R(2) > 0.86 and R(2) > 0.87 was observed for the λ and Nmax , respectively. The overall predictions of both epiphytic bacterial growths under nonisothermal conditions with temperature abuse of 15 °C agreed with the observed data, whereas those with temperature abuse of 25 °C were greatly overestimated. The appropriate parameter q0 (physiological state of cells), therefore, was adjusted by a trial and error to fit the model. This study demonstrates that the developed model was able to predict accurately epiphytic bacterial growth on kale stored under nonisothermal conditions particularly those with low temperature abuse of 15 °C. © 2016 Institute of Food Technologists®

A novel enterocin T1 with anti-Pseudomonas activity produced by Enterococcus faecium T1 from Chinese Tibet cheese.

PubMed

Liu, Hui; Zhang, Lanwei; Yi, Huaxi; Han, Xue; Gao, Wei; Chi, Chunliang; Song, Wei; Li, Haiying; Liu, Chunguang

2016-02-01

An enterocin-producing Enterococcus faecium T1 was isolated from Chinese Tibet cheese. The enterocin was purified by SP-Sepharose and reversed phase HPLC. It was identified as unique from other reported bacteriocins based on molecular weight (4629 Da) and amino acid compositions; therefore it was subsequently named enterocin T1. Enterocin T1 was stable at 80-100 °C and over a wide pH range, pH 3.0-10.0. Protease sensitivity was observed to trypsin, pepsin, papain, proteinase K, and pronase E. Importantly, enterocin T1 was observed to inhibit the growth of numerous Gram-negative and Gram-positive bacteria including Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas fluorescens, Escherichia coli, Salmonella typhimurium, Shigella flexneri, Shigella sonnei, Staphylococcus aureus, Listeria monocytogenes. Take together, these results suggest that enterocin T1 is a novel bacteriocin with the potential to be used as a bio-preservative to control Pseudomonas spp. in food.

Ice-Nucleating Bacteria

NASA Astrophysics Data System (ADS)

Obata, Hitoshi

Since the discovery of ice-nucleating bacteria in 1974 by Maki et al., a large number of studies on the biological characteristics, ice-nucleating substance, ice nucleation gene and frost damage etc. of the bacteria have been carried out. Ice-nucleating bacteria can cause the freezing of water at relatively warm temperature (-2.3°C). Tween 20 was good substrates for ice-nucleating activity of Pseudomonas fluorescens KUIN-1. Major fatty acids of Isolate (Pseudomonas fluorescens) W-11 grown at 30°C were palmitic, cis-9-hexadecenoic and cis-11-octadecenoic which amounted to 90% of the total fatty acids. Sequence analysis shows that an ice nucleation gene from Pseudomonas fluorescens is related to the gene of Pseudomonas syringae.

Molecular Survey of the Occurrence of Legionella spp., Mycobacterium spp., Pseudomonas aeruginosa, and Amoeba Hosts in Two Chloraminated Drinking Water Distribution Systems

PubMed Central

Wang, Hong; Edwards, Marc; Falkinham, Joseph O.

2012-01-01

The spread of opportunistic pathogens via public water systems is of growing concern. The purpose of this study was to identify patterns of occurrence among three opportunistic pathogens (Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa) relative to biotic and abiotic factors in two representative chloraminated drinking water distribution systems using culture-independent methods. Generally, a high occurrence of Legionella (≥69.0%) and mycobacteria (100%), lower occurrence of L. pneumophila (≤20%) and M. avium (≤33.3%), and rare detection of Pseudomonas aeruginosa (≤13.3%) were observed in both systems according to quantitative PCR. Also, Hartmanella vermiformis was more prevalent than Acanthamoeba, both of which are known hosts for opportunistic pathogen amplification, the latter itself containing pathogenic members. Three-minute flushing served to distinguish distribution system water from plumbing in buildings (i.e., premise plumbing water) and resulted in reduced numbers of copies of Legionella, mycobacteria, H. vermiformis, and 16S rRNA genes (P < 0.05) while yielding distinct terminal restriction fragment polymorphism (T-RFLP) profiles of 16S rRNA genes. Within certain subgroups of samples, some positive correlations, including correlations of numbers of mycobacteria and total bacteria (16S rRNA genes), H. vermiformis and total bacteria, mycobacteria and H. vermiformis, and Legionella and H. vermiformis, were noted, emphasizing potential microbial ecological relationships. Overall, the results provide insight into factors that may aid in controlling opportunistic pathogen proliferation in real-world water systems. PMID:22752174

Molecular survey of the occurrence of Legionella spp., Mycobacterium spp., Pseudomonas aeruginosa, and amoeba hosts in two chloraminated drinking water distribution systems.

PubMed

Wang, Hong; Edwards, Marc; Falkinham, Joseph O; Pruden, Amy

2012-09-01

The spread of opportunistic pathogens via public water systems is of growing concern. The purpose of this study was to identify patterns of occurrence among three opportunistic pathogens (Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa) relative to biotic and abiotic factors in two representative chloraminated drinking water distribution systems using culture-independent methods. Generally, a high occurrence of Legionella (≥69.0%) and mycobacteria (100%), lower occurrence of L. pneumophila (≤20%) and M. avium (≤33.3%), and rare detection of Pseudomonas aeruginosa (≤13.3%) were observed in both systems according to quantitative PCR. Also, Hartmanella vermiformis was more prevalent than Acanthamoeba, both of which are known hosts for opportunistic pathogen amplification, the latter itself containing pathogenic members. Three-minute flushing served to distinguish distribution system water from plumbing in buildings (i.e., premise plumbing water) and resulted in reduced numbers of copies of Legionella, mycobacteria, H. vermiformis, and 16S rRNA genes (P < 0.05) while yielding distinct terminal restriction fragment polymorphism (T-RFLP) profiles of 16S rRNA genes. Within certain subgroups of samples, some positive correlations, including correlations of numbers of mycobacteria and total bacteria (16S rRNA genes), H. vermiformis and total bacteria, mycobacteria and H. vermiformis, and Legionella and H. vermiformis, were noted, emphasizing potential microbial ecological relationships. Overall, the results provide insight into factors that may aid in controlling opportunistic pathogen proliferation in real-world water systems.

Incidence of multiple antibiotic resistant Gram-negative bacteria isolated from surface and underground water sources in south western region of Nigeria.

PubMed

Oluyege, J O; Dada, A C; Odeyemi, A T

2009-01-01

In most rural and urban settlements, particularly in Nigeria, wells, spring, streams or rivers and lakes serves as major sources of water supply for drinking and other domestic purposes. Unfortunately, many of the available water sources are not potable without some form of treatment which is seldom available in most settings. The use of untreated surface water sources for drinking and for domestic purposes remains a major threat to public health as these could serve as reservoirs the for transfer of antibiotic resistant pathogens. The incidence of resistant bacteria isolated from surface and underground water in six rural settlements in Ekiti State Nigeria was thus investigated. Gram-negative bacteria were isolated from wells, streams and boreholes in six rural settlements in Ekiti State Nigeria between January and April, 2006 and the prevalence of organisms exhibiting multiple antibiotic resistance to tetracycline, amoxicillin, cotrimoxazole, nitofurantoin, gentamicin, nalidixic acid and ofloxacin was observed. Gram-negative bacterial isolates comprised Escherichia coli (22.7%), Enterobacter aerogenes (2.5%), Salmonella spp. (13.3%), Shigella spp. (19.3%), Proteus spp. (18.5%), Klebsiella spp. (19.3%) and Pseudomonas aeruginosa (4.2%). Over 10% of the bacteria were resistant to four or more antibiotic. Antibiotic resistance was highest in members of the genera Enterobacter, Pseudomonas, and Proteus. Given the prevalence of appalling sanitary facilities and inappropriate public antibiotic use, the possibility of antibiotic resistance selection, faecal dissemination and subsequent contamination of local water sources available for rural residents of the developing world is highlighted. The implication for clinical practice of infections caused by antibiotic resistant strains especially among immunodeficient individuals is also discussed.

Anaerobic bacteria commonly colonize the lower airways of intubated ICU patients.

PubMed

Agvald-Ohman, C; Wernerman, J; Nord, C E; Edlund, C

2003-05-01

To investigate respiratory tract colonization by aerobic and anaerobic bacteria in mechanically ventilated patients. Bacterial colonization of the stomach and the respiratory tract was qualitatively and quantitatively analyzed over time in 41 consecutive mechanically ventilated patients in a Swedish intensive care unit (ICU), with special emphasis on elucidation of the role of anaerobic bacteria in the lower respiratory tract. Samples were taken from the oropharynx, gastric juice, subglottic space and trachea within 24 h (median 14 h) of intubation, and then every third day until day 18 and every fifth day until day 33. The patients were often heavily colonized with microorganisms not considered to belong to a healthy normal oropharyngeal and gastric flora on admission to the ICU. A majority harbored enterococci, coagulase-negative staphylococci and Candida spp. in at least one site on day 1. Anaerobic bacteria, mainly peptostreptococci and Prevotella spp., were isolated from subglottic and/or tracheal secretions in 59% of the patients. Different routes of tracheal colonization for different groups of microorganisms were found. Primary or concomitant colonization of the oropharynx with staphylococci, enterococci, enterobacteria and Candida was often seen, while Pseudomonas spp., other non-fermenting Gram-negative rods and several anaerobic species often primarily colonized the trachea, indicating exogenous or direct gastrointestinal routes of colonization. Mechanically ventilated patients were heavily colonized in their lower airways by potential pathogenic microorganisms, including a high load of anaerobic bacteria. Different routes of colonization were shown for different species.

Detection of relapsing fever Borrelia spp., Bartonella spp. and Anaplasmataceae bacteria in argasid ticks in Algeria

PubMed Central

Bitam, Idir; Leulmi, Hamza; Lalout, Reda; Mediannikov, Oleg; Chergui, Mohamed; Karakellah, Mohamed; Raoult, Didier

2017-01-01

Background Argasid ticks (soft ticks) are blood-feeding arthropods that can parasitize rodents, birds, humans, livestock and companion animals. Ticks of the Ornithodoros genus are known to be vectors of relapsing fever borreliosis in humans. In Algeria, little is known about relapsing fever borreliosis and other bacterial pathogens transmitted by argasid ticks. Methodology/Principal findings Between May 2013 and October 2015, we investigated the presence of soft ticks in 20 rodent burrows, 10 yellow-legged gull (Larus michahellis) nests and animal shelters in six locations in two different bioclimatic zones in Algeria. Six species of argasid ticks were identified morphologically and through 16S rRNA gene sequencing. The presence and prevalence of Borrelia spp., Bartonella spp., Rickettsia spp. and Anaplasmataceae was assessed by qPCR template assays in each specimen. All qPCR-positive samples were confirmed by standard PCR, followed by sequencing the amplified fragments. Two Borrelia species were identified: Borrelia hispanica in Ornithodoros occidentalis in Mostaganem, and Borrelia cf. turicatae in Carios capensis in Algiers. One new Bartonella genotype and one new Anaplasmataceae genotype were also identified in Argas persicus. Conclusions The present study highlights the presence of relapsing fever borreliosis agents, although this disease is rarely diagnosed in Algeria. Other bacteria of unknown pathogenicity detected in argasid ticks which may bite humans deserve further investigation. PMID:29145396

Biodegradation of 2,4'-dichlorobiphenyl, a congener of polychlorinated biphenyl, by Pseudomonas isolates GSa and GSb.

PubMed

Gayathri, D; Shobha, K J

2015-08-01

Bioegradation of 2,4'-dichlorobiphenyl (2,4 CB), by two isolates of Pseudomonas (GSa and GSb) was compared using GC-MS. Transformer oil polluted soil was used for the isolation of 2,4 CB degrading bacteria. GC-MS analysis of the solvent extracts obtained from Pseudomonas sp. GSa spent culture indicated the presence of Phenol 2,6-bis (1,1-dimethyl)-4-methyl (C15H24O). Further, the enzyme analysis of the cell free extracts showed the presence of 2,4'-dichlorobiphenyl dehalogenase (CBD), 2,4'-dichlorobiphenyl-NADPH-oxido-reductase (2,4 CBOR) and 2,3-dihydroxybiphenyl-NADPH-oxido-reductase (2,3 DHOR) with specific activity of 6.00, 0.4 and 0.22 pmol/min/mg of protein, suggesting that dechlorination as an important step during 2,4 CB catabolism. Further, the cell free extract of GSb showed only 2,4'-dichlorobiphenyl-NADPH-oxido-reductase (2,4 CBOR) and 2,3-dihydroxybiphenyl-NADPH-oxido-reductase (2,3 DHOR), with specific activity of 0.3 and 0.213 μmol/min/mg of protein, suggesting attack on non-chlorinated aromatic ring of 2,4 CB, releasing chlorinated intermediates which are toxic to the environment. Although, both the isolated bacteria (GSa and GSb) belong to Pseudomonas spp., they exhibited different metabolic potential.

Cellulose degrading bacteria isolated from industrial samples and the gut of native insects from Northwest of Argentina.

PubMed

Manfredi, Adriana P; Perotti, Nora I; Martínez, María A

2015-12-01

The raw materials used to produce bioethanol mostly are food crops, which has led to conflicts on food security. It is, therefore, recommended the gradual replacement for second generation substrates such as lignocellulosic materials. Herein, cellulolytic bacteria were isolated from the gut content of native larvae from Lepidoptera, Coleoptera, and adults of Isoptera. Few environmental samples from the pulp and paper feedstock were also assessed. A total of 233 isolates were obtained using enrichment cultures and classic criteria. Interestingly, several halo-forming colonies were found to be bacterial consortia that presented difficulties to take apart the microbial members. Those pure isolates which hydrolyzed cellulose in larger extend (45 strains) were selected and identified by means of 16S rRNA sequence analysis. Firmicutes was the prevalent phylum (62.2%) being Bacillus spp. the most frequent genus, while Paenibacillus, Brevibacillus, Cohnella, and Staphylococcus species were less frequent. The phylum Actinobacteria (6.7%) was represented by isolates related to Agromyces spp. and Microbacterium spp. Regarding Gram-negative bacteria (31.1%), the more depicted genus was Pseudomonas spp., and members of Achromobacter spp., Enterobacter spp., and Bacteroidetes phylum were also selected. These native bacterial strains are expected to enlarge the cellulolytic toolbox for efficient biomass deconstruction. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Differentiation of Alcaligenes-like bacteria of avian origin and comparison with Alcaligenes spp. reference strains.

PubMed Central

Berkhoff, H A; Riddle, G D

1984-01-01

Although standard biochemical tests used for the identification of Alcaligenes spp. revealed only minor differences, the oxidative low-peptone technique clearly differentiated between Alcaligenes-like bacteria of avian origin and Alcaligenes spp. reference strains. Based on their colonial morphology, biochemical profiles, and hemagglutination, the Alcaligenes-like bacteria of avian origin were further divided into two subgroups, C1-T1 and C2-T2. Colonies of subgroup C1-T1 were nondescript, round, raised, glistening, translucent, greyish, and about 2 mm in diameter. Colonies of subgroup C2-T2 were off-white, flat, dry and wrinkled, generally round, and resembled tiny lily pads. Biochemical profiles by the oxidative low-peptone method showed the C1-T1 subgroup alkalinizing only three substrates (citrate, acetate, and succinate), whereas the C2-T2 subgroup alkalinized eight substrates (citrate, acetate, butyrate, itaconate, malonate, saccharate, succinate, and M-tartrate). Subgroup C1-T1 agglutinated human, chicken, and turkey erythrocytes, whereas subgroup C2-T2 did not. The recognition of these two subgroups within the Alcaligenes-like bacteria of avian origin is important, since it may explain the differences seen in pathogenicity among isolates. Images PMID:6715517

Differentiation of Alcaligenes-like bacteria of avian origin and comparison with Alcaligenes spp. reference strains.

PubMed

Berkhoff, H A; Riddle, G D

1984-04-01

Although standard biochemical tests used for the identification of Alcaligenes spp. revealed only minor differences, the oxidative low-peptone technique clearly differentiated between Alcaligenes-like bacteria of avian origin and Alcaligenes spp. reference strains. Based on their colonial morphology, biochemical profiles, and hemagglutination, the Alcaligenes-like bacteria of avian origin were further divided into two subgroups, C1-T1 and C2-T2. Colonies of subgroup C1-T1 were nondescript, round, raised, glistening, translucent, greyish, and about 2 mm in diameter. Colonies of subgroup C2-T2 were off-white, flat, dry and wrinkled, generally round, and resembled tiny lily pads. Biochemical profiles by the oxidative low-peptone method showed the C1-T1 subgroup alkalinizing only three substrates (citrate, acetate, and succinate), whereas the C2-T2 subgroup alkalinized eight substrates (citrate, acetate, butyrate, itaconate, malonate, saccharate, succinate, and M-tartrate). Subgroup C1-T1 agglutinated human, chicken, and turkey erythrocytes, whereas subgroup C2-T2 did not. The recognition of these two subgroups within the Alcaligenes-like bacteria of avian origin is important, since it may explain the differences seen in pathogenicity among isolates.

Computer-aided discovery in antimicrobial research: In silico model for virtual screening of potent and safe anti-pseudomonas agents.

PubMed

Speck-Planche, Alejandro; Cordeiro, Maria N D S

2015-01-01

Resistance of bacteria to current antibiotics is an alarming health problem. In this sense, Pseudomonas represents a genus of Gram-negative pathogens, which has emerged as one of the most dangerous species causing nosocomial infections. Despite the effort of the scientific community, drug resistant strains of bacteria belonging to Pseudomonas spp. prevail. The high costs associated to drug discovery and the urgent need for more efficient antimicrobial chemotherapies envisage the fact that computeraided methods can rationalize several stages involved in the development of a new drug. In this work, we introduce a chemoinformatic methodology devoted to the construction of a multitasking model for quantitative-structure biological effect relationships (mtk-QSBER). The purpose of this model was to perform simultaneous predictions of anti-Pseudomonas activities and ADMET (absorption, distribution, metabolism, elimination, and toxicity) properties of organic compounds. The mtk-QSBER model was created from a large and heterogeneous dataset (more than 54000 cases) and displayed accuracies higher than 90% in both training and prediction sets. In order to demonstrate the applicability of our mtk-QSBER model, we used the investigational antibacterial drug delafloxacin as a case of study, for which experimental results were recently reported. The predictions performed for many biological effects of this drug exhibited a remarkable convergence with the experimental assays, confirming that our model can serve as useful tool for virtual screening of potent and safer anti-Pseudomonas agents.

Enteropathogenic Bacteria Contamination of Unchlorinated Drinking Water in Korea, 2010

PubMed Central

Lee, Si Won; Lee, Do Kyung; An, Hyang Mi; Cha, Min Kyeong; Kim, Kyung Jae

2011-01-01

Objectives The purpose of this study was to assess the microbiological quality of unchlorinated drinking water in Korea, 2010. One hundred and eighty unchlorinated drinking water samples were collected from various sites in Seoul and Gyeonggi province. Methods To investigate bacterial presence, the pour plate method was used with cultures grown on selective media for total bacteria, total coliforms, and Staphylococcus spp., respectively. Results In the 180 total bacteria investigation, 72 samples from Seoul and 33 samples from Gyeonggi province were of an unacceptable quality (>102 CFU/mL). Of all the samples tested, total coliforms were detected in 28 samples (15.6%) and Staphylococcus spp. in 12 samples (6.7%). Most of the coliform isolates exhibited high-level resistance to cefazolin (88.2%), cefonicid (64.7%) and ceftazidime (20.6%). In addition, Staphylococcus spp. isolates exhibited high-level resistance to mupirocin (42%). Species of Pseudomonas, Acinetobacter, Cupriavidus, Hafnia, Rahnella, Serratia, and Yersinia were isolated from the water samples. Conclusions The results of this study suggest that consumption of unchlorinated drinking water could represent a notable risk to the health of consumers. As such, there is need for continuous monitoring of these water sources and to establish standards. PMID:22216417

Pulmonary inflammation induced by bacteria-free outer membrane vesicles from Pseudomonas aeruginosa.

PubMed

Park, Kyong-Su; Lee, Jaewook; Jang, Su Chul; Kim, Sae Rom; Jang, Myoung Ho; Lötvall, Jan; Kim, Yoon-Keun; Gho, Yong Song

2013-10-01

Pseudomonas aeruginosa is often involved in lung diseases such as cystic fibrosis. These bacteria can release outer membrane vesicles (OMVs), which are bilayered proteolipids with diameters of approximately 20 to 250 nm. In vitro, these OMVs activate macrophages and airway epithelial cells. The aim of this study was to determine whether OMVs from P. aeruginosa can induce pulmonary inflammation in vivo and to elucidate the mechanisms involved. Bacteria-free OMVs were isolated from P. aeruginosa cultures. Wild-type, Toll-like receptor (TLR)2 and TLR4 knockout mice were exposed to OMVs by the airway, and inflammation in the lung was assessed using differential counts, histology, and quantification of chemokines and cytokines. The involvement of the TLR2 and TLR4 pathways was studied in human cells using transfection. OMVs given to the mouse lung caused dose- and time-dependent pulmonary cellular inflammation. Furthermore, OMVs increased concentrations of several chemokines and cytokines in the mouse lungs and mouse alveolar macrophages. The inflammatory responses to OMVs were comparable to those of live bacteria and were only partly regulated by the TLR2 and TLR4 pathways, according to studies in knockout mice. This study shows that OMVs from P. aeruginosa cause pulmonary inflammation without live bacteria in vivo. This effect is only partly controlled by TLR2 and TLR4. The role of OMVs in clinical disease warrants further studies because targeting of OMVs in addition to live bacteria may add clinical benefit compared with treating with antibiotics alone.

Carriage by the housefly (Musca domestica) of multiple-antibiotic-resistant bacteria that are potentially pathogenic to humans, in hospital and other urban environments in Misurata, Libya.

PubMed

Rahuma, N; Ghenghesh, K S; Ben Aissa, R; Elamaari, A

2005-12-01

Using standard microbiological procedures, bacteria that are potentially pathogenic to humans were isolated from 150 houseflies collected in the Libyan city of Misurata (50 flies each from the Central Hospital, streets and abattoir). Salmonella spp., Yersinia enterocolitica and Edwardsiella tarda were isolated from flies collected on the streets and in the abattoir but not from those collected in the hospital. Shigella sonnei was detected in just one fly, which was collected in the abattoir. Of the flies collected in the hospital, streets and abattor, 42%, 42% and 32% were positive for Escherichia coli, 70%, 50% and 62% for Klebsiella spp., 2%, 20% and 10% for Aeromonas spp., 96%, 36% and 34% for Pseudomonas spp., 20%, 12% and 16% for Staphylococcus spp., and 24%, 22% and 18% for Streptococcus spp., respectively. When the antibiotic susceptibilities of the fly isolates were investigated, the Enterobacteria isolated from the houseflies collected in the hospital were found to be resistant to significantly more of the commonly used antibiotics that were tested than the Enterobacteria isolated from the flies caught in the streets or abattoir. Whatever the source of the flies from which they were collected, the Pseudomonas isolates frequently showed resistance to multiple antibiotics, with >50% each being resistant to at least 10 antimicrobial agents. Two isolates of Sta. aureus (both from flies collected in the hospital) were resistant to methicillin. The present study supports the belief that the housefly is a potential vector of multiple-antibiotic-resistant, pathogenic bacteria, including methicillin-resistant Sta. aureus, in the hospital environment. Given their mobility, it seems likely that houseflies carry such pathogens from hospitals to surrounding communities, and vice versa.

Importance of Aspergillus spp. isolation in Acute exacerbations of severe COPD: prevalence, factors and follow-up: the FUNGI-COPD study

PubMed Central

2014-01-01

Background Acute exacerbations of COPD (AECOPD) are often associated with infectious agents, some of which may be non-usual, including Aspergillus spp. However, the importance of Aspergillus spp. in the clinical management of AECOPD still remains unclear. Objectives The aims of the study were to analyze the prevalence and risk factors associated with Aspergillus spp. isolation in AECOPD, and to investigate the associated clinical outcomes during a 1-year follow-up period. Methods Patients presenting with an AECOPD requiring hospitalization were prospectively included from four hospitals across Spain. Clinical, radiological and microbiological data were collected at admission and during the follow-up period (1, 6 and 12 months after discharge), and re-admissions and mortality data collected during the follow-up. Results A total of 240 patients with severe AECOPD were included. Valid sputum samples were obtained in 144 (58%) patients, and in this group, the prevalence of Aspergillus spp. isolation was 16.6% on admission and 14.1% at one-year follow-up. Multivariate logistic-regression showed that AECOPD in the previous year (OR 12.35; 95% CI, 1.9-29.1; p < 0.001), concurrent isolation of pathogenic bacteria (OR 3.64; 95% CI 1.65-9.45, p = 0.001) and concomitant isolation of Pseudomonas aeruginosa (OR 2.80; 95% IC, 1.81-11.42; p = 0.001) were the main risk factors for Aspergillus spp. isolation. Conclusions The main risk factors for Aspergillus spp. isolation were AECOPD in the previous year and concomitant isolation of Pseudomonas aeruginosa. However, although Aspergillus spp. is often isolated in sputum samples from patients with AECOPD, the pathogenic and clinical significance remains unclear. PMID:24517318

The Role of 2,4-diacetylphloroglucinol- and phenazine-1-carboxylic acid-producing Pseudomonas spp. in Natural Protection of Wheat from Soilborne Pathogens

USDA-ARS?s Scientific Manuscript database

Fluorescent Pseudomonas isolated from the rhizosphere of diverse plants have been studied as biocontrol agents of soilborne pathogens worldwide. Certain strains of these bacteria are capable of exerting a variety of mechanisms of plant growth promotion and protection, including the production of the...

The Pseudomonas fluorescens Siderophore Pyoverdine Weakens Arabidopsis thaliana Defense in Favor of Growth in Iron-Deficient Conditions1

PubMed Central

Trapet, Pauline; Avoscan, Laure; Klinguer, Agnès; Pateyron, Stéphanie; Chervin, Christian; Mazurier, Sylvie; Lemanceau, Philippe; Wendehenne, David; Besson-Bard, Angélique

2016-01-01

Pyoverdines are siderophores synthesized by fluorescent Pseudomonas spp. Under iron-limiting conditions, these high-affinity ferric iron chelators are excreted by bacteria in the soil to acquire iron. Pyoverdines produced by beneficial Pseudomonas spp. ameliorate plant growth. Here, we investigate the physiological incidence and mode of action of pyoverdine from Pseudomonas fluorescens C7R12 on Arabidopsis (Arabidopsis thaliana) plants grown under iron-sufficient or iron-deficient conditions. Pyoverdine was provided to the medium in its iron-free structure (apo-pyoverdine), thus mimicking a situation in which it is produced by bacteria. Remarkably, apo-pyoverdine abolished the iron-deficiency phenotype and restored the growth of plants maintained in the iron-deprived medium. In contrast to a P. fluorescens C7R12 strain impaired in apo-pyoverdine production, the wild-type C7R12 reduced the accumulation of anthocyanins in plants grown in iron-deficient conditions. Under this condition, apo-pyoverdine modulated the expression of around 2,000 genes. Notably, apo-pyoverdine positively regulated the expression of genes related to development and iron acquisition/redistribution while it repressed the expression of defense-related genes. Accordingly, the growth-promoting effect of apo-pyoverdine in plants grown under iron-deficient conditions was impaired in iron-regulated transporter1 and ferric chelate reductase2 knockout mutants and was prioritized over immunity, as highlighted by an increased susceptibility to Botrytis cinerea. This process was accompanied by an overexpression of the transcription factor HBI1, a key node for the cross talk between growth and immunity. This study reveals an unprecedented mode of action of pyoverdine in Arabidopsis and demonstrates that its incidence on physiological traits depends on the plant iron status. PMID:26956666

Genomic analysis of the type VI secretion systems in Pseudomonas spp.: novel clusters and putative effectors uncovered.

PubMed

Barret, Matthieu; Egan, Frank; Fargier, Emilie; Morrissey, John P; O'Gara, Fergal

2011-06-01

Bacteria encode multiple protein secretion systems that are crucial for interaction with the environment and with hosts. In recent years, attention has focused on type VI secretion systems (T6SSs), which are specialized transporters widely encoded in Proteobacteria. The myriad of processes associated with these secretion systems could be explained by subclasses of T6SS, each involved in specialized functions. To assess diversity and predict function associated with different T6SSs, comparative genomic analysis of 34 Pseudomonas genomes was performed. This identified 70 T6SSs, with at least one locus in every strain, except for Pseudomonas stutzeri A1501. By comparing 11 core genes of the T6SS, it was possible to identify five main Pseudomonas phylogenetic clusters, with strains typically carrying T6SSs from more than one clade. In addition, most strains encode additional vgrG and hcp genes, which encode extracellular structural components of the secretion apparatus. Using a combination of phylogenetic and meta-analysis of transcriptome datasets it was possible to associate specific subsets of VgrG and Hcp proteins with each Pseudomonas T6SS clade. Moreover, a closer examination of the genomic context of vgrG genes in multiple strains highlights a number of additional genes associated with these regions. It is proposed that these genes may play a role in secretion or alternatively could be new T6S effectors.

pA506, a Conjugative Plasmid of the Plant Epiphyte Pseudomonas fluorescens A506

PubMed Central

Stockwell, Virginia O.; Davis, Edward W.; Carey, Alyssa; Shaffer, Brenda T.; Mavrodi, Dmitri V.; Hassan, Karl A.; Hockett, Kevin; Thomashow, Linda S.; Paulsen, Ian T.

2013-01-01

Conjugative plasmids are known to facilitate the acquisition and dispersal of genes contributing to the fitness of Pseudomonas spp. Here, we report the characterization of pA506, the 57-kb conjugative plasmid of Pseudomonas fluorescens A506, a plant epiphyte used in the United States for the biological control of fire blight disease of pear and apple. Twenty-nine of the 67 open reading frames (ORFs) of pA506 have putative functions in conjugation, including a type IV secretion system related to that of MOBP6 family plasmids and a gene cluster for type IV pili. We demonstrate that pA506 is self-transmissible via conjugation between A506 and strains of Pseudomonas spp. or the Enterobacteriaceae. The origin of vegetative replication (oriV) of pA506 is typical of those in pPT23A family plasmids, which are present in many pathovars of Pseudomonas syringae, but pA506 lacks repA, a defining locus for pPT23A plasmids, and has a novel partitioning region. We selected a plasmid-cured derivative of A506 and compared it to the wild type to identify plasmid-encoded phenotypes. pA506 conferred UV resistance, presumably due to the plasmid-borne rulAB genes, but did not influence epiphytic fitness of A506 on pear or apple blossoms in the field. pA506 does not appear to confer resistance to antibiotics or other toxic elements. Based on the conjugative nature of pA506 and the large number of its genes that are shared with plasmids from diverse groups of environmental bacteria, the plasmid is likely to serve as a vehicle for genetic exchange between A506 and its coinhabitants on plant surfaces. PMID:23811504

Brevundimonas spp: Emerging global opportunistic pathogens

PubMed Central

2018-01-01

ABSTRACT Non-fermenting Gram-negative bacteria are problematic in clinical locations, being one of the most prevalent causes of nosocomial infections. Many of these non-fermenting Gram-negative bacteria are opportunistic pathogens that affect patients that are suffering with underlying medical conditions and diseases. Brevundimonas spp., in particular Brevundimonas diminuta and Brevundimonas vesicularis, are a genus of non-fermenting Gram-negative bacteria considered of minor clinical importance. Forty-nine separate instances of infection relating to Brevundimonas spp were found in the scientific literature along with two pseudo-infections. The majority of these instances were infection with Brevundimonas vesicularis (thirty-five cases – 71%). The major condition associated with Brevundimonas spp infection was bacteraemia with seventeen individual cases/outbreaks (35%). This review identified forty-nine examples of Brevundimonas spp. infections have been discussed in the literature. These findings indicate that infection review programs should consider investigation of possible Brevundimonas spp outbreaks if these bacteria are clinically isolated in more than one patient. PMID:29484917

Pseudomonas fluorescens-like bacteria from the stomach: a microbiological and molecular study.

PubMed

Patel, Saurabh Kumar; Pratap, Chandra Bhan; Verma, Ajay Kumar; Jain, Ashok Kumar; Dixit, Vinod Kumar; Nath, Gopal

2013-02-21

To characterize oxidase- and urease-producing bacterial isolates, grown aerobically, that originated from antral biopsies of patients suffering from acid peptic diseases. A total of 258 antral biopsy specimens were subjected to isolation of bacteria followed by tests for oxidase and urease production, acid tolerance and aerobic growth. The selected isolates were further characterized by molecular techniques viz. amplifications for 16S rRNA using universal eubacterial and HSP60 gene specific primers. The amplicons were subjected to restriction analysis and partial sequencing. A phylogenetic tree was generated using unweighted pair group method with arithmetic mean (UPGMA) from evolutionary distance computed with bootstrap test of phylogeny. Assessment of acidity tolerance of bacteria isolated from antrum was performed using hydrochloric acid from 10(-7) mol/L to 10(-1) mol/L. Of the 258 antral biopsy specimens collected from patients, 179 (69.4%) were positive for urease production by rapid urease test and 31% (80/258) yielded typical Helicobacter pylori (H. pylori) after 5-7 d of incubation under a microaerophilic environment. A total of 240 (93%) antral biopsies yielded homogeneous semi-translucent and small colonies after overnight incubation. The partial 16S rRNA sequences revealed that the isolates had 99% similarity with Pseudomonas species. A phylogenetic tree on the basis of 16S rRNA sequences denoted that JQ927226 and JQ927227 were likely to be related to Pseudomonas fluorescens (P. fluorescens). On the basis of HSP60 sequences applied to the UPGMA phylogenetic tree, it was observed that isolated strains in an aerobic environment were likely to be P. fluorescens, and HSP60 sequences had more discriminatory potential rather than 16S rRNA sequences. Interestingly, this bacterium was acid tolerant for hours at low pH. Further, a total of 250 (96.9%) genomic DNA samples of 258 biopsy specimens and DNA from 240 bacterial isolates were positive for the 613 bp

Transport of Salmonella spp. and indicator bacteria to drainage tile waters under cornfields receiving poultry manure

USDA-ARS?s Scientific Manuscript database

E. coli and enterococci are commonly used as pathogen indicators in surface water, however, the transport of these bacteria to drainage tiles from manure application fields and the correlation of these indicators to pathogens in this setting is poorly understood. Salmonella spp. is prevalent in poul...

Bloom of resident antibiotic-resistant bacteria in soil following manure fertilization.

PubMed

Udikovic-Kolic, Nikolina; Wichmann, Fabienne; Broderick, Nichole A; Handelsman, Jo

2014-10-21

The increasing prevalence of antibiotic-resistant bacteria is a global threat to public health. Agricultural use of antibiotics is believed to contribute to the spread of antibiotic resistance, but the mechanisms by which many agricultural practices influence resistance remain obscure. Although manure from dairy farms is a common soil amendment in crop production, its impact on the soil microbiome and resistome is not known. To gain insight into this impact, we cultured bacteria from soil before and at 10 time points after application of manure from cows that had not received antibiotic treatment. Soil treated with manure contained a higher abundance of β-lactam-resistant bacteria than soil treated with inorganic fertilizer. Functional metagenomics identified β-lactam-resistance genes in treated and untreated soil, and indicated that the higher frequency of resistant bacteria in manure-amended soil was attributable to enrichment of resident soil bacteria that harbor β-lactamases. Quantitative PCR indicated that manure treatment enriched the blaCEP-04 gene, which is highly similar (96%) to a gene found previously in a Pseudomonas sp. Analysis of 16S rRNA genes indicated that the abundance of Pseudomonas spp. increased in manure-amended soil. Populations of other soil bacteria that commonly harbor β-lactamases, including Janthinobacterium sp. and Psychrobacter pulmonis, also increased in response to manure treatment. These results indicate that manure amendment induced a bloom of certain antibiotic-resistant bacteria in soil that was independent of antibiotic exposure of the cows from which the manure was derived. Our data illustrate the unintended consequences that can result from agricultural practices, and demonstrate the need for empirical analysis of the agroecosystem.

Bloom of resident antibiotic-resistant bacteria in soil following manure fertilization

PubMed Central

Udikovic-Kolic, Nikolina; Wichmann, Fabienne; Broderick, Nichole A.; Handelsman, Jo

2014-01-01

The increasing prevalence of antibiotic-resistant bacteria is a global threat to public health. Agricultural use of antibiotics is believed to contribute to the spread of antibiotic resistance, but the mechanisms by which many agricultural practices influence resistance remain obscure. Although manure from dairy farms is a common soil amendment in crop production, its impact on the soil microbiome and resistome is not known. To gain insight into this impact, we cultured bacteria from soil before and at 10 time points after application of manure from cows that had not received antibiotic treatment. Soil treated with manure contained a higher abundance of β-lactam–resistant bacteria than soil treated with inorganic fertilizer. Functional metagenomics identified β-lactam–resistance genes in treated and untreated soil, and indicated that the higher frequency of resistant bacteria in manure-amended soil was attributable to enrichment of resident soil bacteria that harbor β-lactamases. Quantitative PCR indicated that manure treatment enriched the blaCEP-04 gene, which is highly similar (96%) to a gene found previously in a Pseudomonas sp. Analysis of 16S rRNA genes indicated that the abundance of Pseudomonas spp. increased in manure-amended soil. Populations of other soil bacteria that commonly harbor β-lactamases, including Janthinobacterium sp. and Psychrobacter pulmonis, also increased in response to manure treatment. These results indicate that manure amendment induced a bloom of certain antibiotic-resistant bacteria in soil that was independent of antibiotic exposure of the cows from which the manure was derived. Our data illustrate the unintended consequences that can result from agricultural practices, and demonstrate the need for empirical analysis of the agroecosystem. PMID:25288759

Synergistic action between sisomicin and mezlocillin against gram-negative bacteria and Staphylococcus aureus.

PubMed

Soares, L A; Trabulsi, L R

1979-01-01

The combined effect of sisomicin and 6-[(R)-2-[3-methylsulfonyl-2-oxo-imidazolidine-1-carboxamido]-2-phenyl-acetamido-a1-penicillanic acid sodium salt (mezlocillin, Baypen) was studied against 50 bacterial strains, including Pseudomonas aeruginosa, Proteus spp. Klebsiella-Enterobacter, E. coli and Staphylococcus aureus. No antagonism or indifference was detected with the strains studied. Both antibiotics were synergistic against 62% of the strains, and partially synergistic against 38%. Out of the bacteria studied, Staphylococcus aureus was the most susceptible to the combined action of sisomicin and mezlocillin.

Effect of Pseudomonas spp on infection of Peronosporaparasitica (Pers. Fr), the pathogen of downy mildew on Chinese cabbage

NASA Astrophysics Data System (ADS)

Damiri, N.; Mulawarman; Umayah, A.; Agustin, S. E.; Rahmiyah, M.

2018-01-01

This research was conducted to study the effect of the application of Pseudomonasspp on infection of Peronosporaparasitica (Pers. Fr), the pathogen of Downy mildew on Chinese cabbage. The research was conducted in the laboratory and greenhouse Department of Plant Pests and Diseases Faculty of Agriculture Sriwijaya University, Inderalaya, OganIlir South Sumatra Indonesia. The research was conducted in the laboratory and greenhouse Department of Plant Pests and Diseases Faculty of Agriculture Sriwijaya University, Inderalaya, Ogan Ilir South Sumatra Indonesia. The research was conducted using Completely Randomized Design with ten treatments including control. ie: isolate A, Isolate B, isolate C, isolate D, isolate E, isolate F, isolate G, isolate H, isolate I and control. Each treatment consists of four replications. Results of the study showed that the application of Pseudomonas spp. can suppress the infection of P. parasitica on Chinese cabbage. The lowest disease intensity was shown by treatment C (isolate Pseudomonas sp.) which was significantly different from control. The best treatment in suppressing disease severity of downy mildew on chinese cabbage was isolate H which had disease severity of 37.07 percent, which was significantly different from control and other treatment.

Microbiological methods for surveillance of carrier status of multiresistant bacteria.

PubMed

Oteo, Jesús; Bou, Germán; Chaves, Fernando; Oliver, Antonio

2017-12-01

The presence of colonised patients is one of the main routes for the spread of multiresistant bacteria, and its containment is a clinical and public health priority. Surveillance studies are essential for early detection of colonisation by these bacteria. This article discusses the different microbiological methods, both based on culturing and molecular methods, for detection of carriers of multiresistant bacteria. Those species with a high clinical/epidemiological impact or generating therapeutic difficulties are included: Methicillin-resistant Staphylococcus aureus, Enterococcus spp. resistant to glycopeptides, enterobacteriaceae producing extended spectrum β-lactamases and plasmid-mediated AmpC, carbapenemases producing enterobacteriaceae, Acinetobacter baumannii and multiresistant Pseudomonas aeruginosa. The information in this document should be considered as a structure matrix to be tailored to the specific needs of each centre. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Identities of Arthrobacter spp. and Arthrobacter-Like Bacteria Encountered in Human Clinical Specimens▿

PubMed Central

Mages, Irene S.; Frodl, Reinhard; Bernard, Kathryn A.; Funke, Guido

2008-01-01

After the initial description of Arthrobacter spp. isolated from clinical specimens in the mid-1990s, very few further reports on Arthrobacter spp. have appeared in the clinical microbiology literature. The aim of the present study was to elucidate the distribution of Arthrobacter spp. and Arthrobacter-like bacteria encountered in clinical specimens by studying 50 consecutively isolated or received strains of large-colony-forming, whiteish-grayish, non-cheese-like-smelling, nonfermentative gram-positive rods by applying phenotypic methods as well as 16S rRNA gene sequencing. We observed a very heterogenous distribution, with the 50 strains belonging to 20 different taxa and each of 13 strains as a single representative of its particular taxon. Thirty-eight strains represented true Arthrobacter strains, 7 strains belonged to the genus Brevibacterium, 2 were Microbacterium species, and each of 3 single strains was a member of the rarely encountered genera Pseudoclavibacter, Leucobacter, and Brachybacterium, respectively. A. cumminsii (n = 14) and A. oxydans (n = 11) were the most frequently found species. The present report describes the first three A. aurescens strains isolated from human clinical specimens. Comprehensive antimicrobial susceptibility data are given for the 38 Arthrobacter isolates. PMID:18650355

Uncovering behavioural diversity amongst high-strength Pseudomonas spp. surfactants at the limit of liquid surface tension reduction.

PubMed

Kabir, Kamaluddeen; Deeni, Yusuf Y; Hapca, Simona M; Moore, Luke; Spiers, Andrew J

2018-02-01

Bacterial biosurfactants have a wide range of biological functions and biotechnological applications. Previous analyses had suggested a limit to their reduction of aqueous liquid surface tensions (γMin), and here we confirm this in an analysis of 25 Pseudomonas spp. strains isolated from soil which produce high-strength surfactants that reduce surface tensions to 25.2 ± 0.1-26.5 ± 0.2 mN m-1 (the surface tension of sterile growth medium and pure water was 52.9 ± 0.4 mN m-1 and 72.1 ± 1.2 mN m-1, respectively). Comparisons of culture supernatants produced using different growth media and semi-purified samples indicate that the limit of 24.2-24.7 mN m-1 is not greatly influenced by culture conditions, pH or NaCl concentrations. We have used foam, emulsion and oil-displacement behavioural assays as a simple and cost-effective proxy for in-depth biochemical characterisation, and these suggest that there is significant structural diversity amongst these surfactants that may reflect different biological functions and offer new biotechnological opportunities. Finally, we obtained a draft genome for the strain producing the highest strength surfactant, and identified a cluster of non-ribosomal protein synthase genes that may produce a cyclic lipopeptide (CLP)-like surfactant. Further investigation of this group of related bacteria recovered from the same site will allow a better understanding of the significance of the great variety of surfactants produced by bacterial communities found in soil and elsewhere. © FEMS 2018. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Characterizing the Catalytic Potential of Deinococcus, Arthrobacter and other Robust Bacteria in Contaminated Subsurface Environments of the Hanford Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daly, Michael J.

2006-05-01

Ionizing Radiation (IR) Resistance in Bacteria. Until recently, there have been no clear physiologic predictors of a cell's ability to recover from ionizing radiation (IR) and other DOE-relevant oxidative stress conditions. In general, the most resistant bacteria have been Gram-positive (e.g., Deinococcus, Arthrobacter, Lactobacillus & Enterococcus spp.) and the most sensitive have been Gram-negative (e.g., Pseudomonas, Shewanella & Neisseria spp.). However, there are several reported exceptions to this paradigm, the Gram-negative cyanobacterium Chroococcidiopsis is extremely resistant to IR, whereas the Gram-positive Micrococcus luteus is sensitive. We have identified biomolecular signatures for radiation sensitivity and resistance which are independent of phylogeny,more » where very high and very low intracellular Mn/Fe concentration ratios correlated with very high and very low resistances, respectively; and restricting Mn(II) in the famously resistant Deinococcus radiodurans sensitized this eubacterium to IR.« less

Hospital microbial surface colonization revealed during monitoring of Klebsiella spp., Pseudomonas aeruginosa, and non-tuberculous mycobacteria.

PubMed

Geadas Farias, Pedro; Gama, Fernando; Reis, Diogo; Alarico, Susana; Empadinhas, Nuno; Martins, José Carlos; de Almeida, Ana Figueiredo; Morais, Paula Vasconcelos

2017-07-01

Hospital environmental conditions, human occupancy, and the characteristics of the equipment influence the survival of microbial communities and raise a concern with regard to nosocomial infections. The objective of the present work was to use the monitoring of Pseudomonas aeruginosa, Klebsiella spp. and non-tuberculous mycobacteria as a strategy to improve knowledge on microbial colonization of non-critical equipment and surfaces, in a tertiary hospital from Central Portugal. A 3-month microbiological survey was performed in a district teaching hospital. A total of 173 samples were obtained from the wards Hematology, Urology, Medicine, and Renal Transplants, and 102 presumptive strains recovered. Per sampling, Pseudomonas Isolation agar showed 42.8 to 73.3% of presumptive P. aeruginosa colonies and MacConkey agar recovered mostly Staphylococcus. Most of the colonies recovered in Middlebrook 7H10-PANTA belonged to the genus Methylobacterium. Taps and WC shower curtains carry high bacterial species diversity. The Redundancy Analysis grouped the samples in those mostly handled by patients, and those mostly handled by healthcare staff or of mixed use. This study shows that the preferential users of the space and equipment seem to be important contributors to the microbial community. The most recovered genus was Methylobacterium, known as colonizer of the water distribution system therefore, it is possible that the water points and biofilms in taps also contribute as dispersion hotspots.

MALDI-TOF MS Andromas strategy for the routine identification of bacteria, mycobacteria, yeasts, Aspergillus spp. and positive blood cultures.

PubMed

Bille, E; Dauphin, B; Leto, J; Bougnoux, M-E; Beretti, J-L; Lotz, A; Suarez, S; Meyer, J; Join-Lambert, O; Descamps, P; Grall, N; Mory, F; Dubreuil, L; Berche, P; Nassif, X; Ferroni, A

2012-11-01

All organisms usually isolated in our laboratory are now routinely identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) using the Andromas software. The aim of this study was to describe the use of this strategy in a routine clinical microbiology laboratory. The microorganisms identified included bacteria, mycobacteria, yeasts and Aspergillus spp. isolated on solid media or extracted directly from blood cultures. MALDI-TOF MS was performed on 2665 bacteria isolated on solid media, corresponding to all bacteria isolated during this period except Escherichia coli grown on chromogenic media. All acquisitions were performed without extraction. After a single acquisition, 93.1% of bacteria grown on solid media were correctly identified. When the first acquisition was not contributory, a second acquisition was performed either the same day or the next day. After two acquisitions, the rate of bacteria identified increased to 99.2%. The failures reported on 21 strains were due to an unknown profile attributed to new species (9) or an insufficient quality of the spectrum (12). MALDI-TOF MS has been applied to 162 positive blood cultures. The identification rate was 91.4%. All mycobacteria isolated during this period (22) were correctly identified by MALDI-TOF MS without any extraction. For 96.3% and 92.2% of yeasts and Aspergillus spp., respectively, the identification was obtained with a single acquisition. After a second acquisition, the overall identification rate was 98.8% for yeasts (160/162) and 98.4% (63/64) for Aspergillus spp. In conclusion, the MALDI-TOF MS strategy used in this work allows a rapid and efficient identification of all microorganisms isolated routinely. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

Antibiogram of bacteria isolated from automated teller machines in Hamadan, West Iran

PubMed Central

Mahmoudi, Hassan; Arabestani, Mohammad Reza; Alikhani, Mohammad Yousef; Sedighi, Iraj; Kohan, Hamed Farhadi; Molavi, Mohammad

2017-01-01

Aim: Bacteria are ubiquitous in the environment. In keeping with the continued expansion of urbanization and the growing population, an increasing number of people use automated banking, i.e. automated teller machines (ATMs). The aim of this study was to investigate the bacterial contamination and its antibiotic sensitivity on computer keyboards located at ATMs in Hamadan province, Iran. Method: Out of 360 ATMs at four locations in Hamadan, 96 were randomly selected for this study. The antibiotic susceptibility pattern of all isolates was determined by the agar disk diffusion method using gentamicin (10 µg), vancomycin (30 µg), trimethoprim/sulfamethoxazole (25 µg), amikacin (30 µg), tobramycin (10 µg), cephalotin (30 µg), norfloxacin (5 µg), and ceftizoxim (30 µg) disks. Results: Melli and Saderat Banks had the most frequently contaminated ATMS, with 18 (27.7%) and 12 (18.5%), respectively. The most frequently isolated bacteria were Staphylococcus epidermidis in 12 (18.5%) ATMs, Pseudomonas aeruginosa in 12 (18.5%), Bacillus subtilis in 11 (16.9%), Escherichia coli in 6 (9.2%), Klebsiella spp. in 8 (12.3%), Enterobacter spp. in 2 (3.1%), Bacillus cereus in 6 (9.2%), Staphylococcus aureus in 3 (4.6%), and Micrococcaceae spp. in 5 (7.69%) cases. All isolated bacteria were susceptible to gentamicin, cephalotin, tobramycin, amikacin, norfloxacin, and vancomycin. The S. aureus resistance rate to trimethoprim/sulfamethoxazole was 50%. Conclusion: All tested ATM keyboards were contaminated with at least one species of bacteria. Based on these findings, it is recommendable to disinfect the hands after entering one’s own apartment, work area or a hospital, in order to hinder the spread of critical pathogens in the personal environment or in the hospital. PMID:28197394

Bacteria mediated dissolution of pyromorphite Pb5(PO4)3Cl in presence of Pseudomonas putida bacteria - an effect on Pb remobilization in the environment

NASA Astrophysics Data System (ADS)

Flis, Justyna; Manecki, Maciej; Merkel, Broder J.; Latowski, Dariusz

2010-05-01

The objective of the study was to determine the mechanisms of microbially enhanced dissolution of lead phosphate-pyromorphite Pb5(PO4)3Cl). Contrary to the current literature, the results of our experiments indicate a great potential for Pb remobilization in the environment by an aerobic microorganism acquiring phosphates. Broad knowledge exists about the role of Pb-apatites in regulating the behavior and the bioavailability of Pb in soils and wastewater. In situ Pb immobilization is one of the methods now routinely applied for the reclamation of Pb-contaminated soils, including shallow unconfined aquifers (Magalhaes & Silva, 2003; Magalhaes, 2002; Ma et al. 1993). This method is based on the principle that aqueous phosphates added to soil pore solutions form a very stable (insoluble) mineral pyromorphite (Pb-apatite) Pb5(PO4)3Cl. Bioavailability of aqueous Pb is thus minimized due to the very low solubility and the high thermodynamic stability of pyromorphite (Flis, 2007; Nriagu, 1974). Several reports have examined the ability of different bacterial species including Pseudomonas to solubilise insoluble inorganic phosphate compounds for example apatites (Welch et al., 2002; Maurice et al., 1999; Rodriguez and Fraga, 1999 ). Various species of Pseudomonas genera are encountered as common inhabitants of soils and wastes in the industrial areas under strong pollution influence. To date, there has not been any published evidence of microbial dissolution of pyromorphite. The major objective of the project was to study Pseudomonas putida growth in the presence of Pb-apatite (Pb5(PO4)3Cl) as the sole source of phosphate. It was to test the hypothesis that in the phosphate deficient environment bacteria are able to actively scavenge for P from the Pb-apatite which results in remobilization of Pb in the environment. The bacteria growth was investigated at 22oC. Commercially available Pseudomonas putida strain was used throughout. The experiment and its controls were run in

IDENTIFICATION OF BACTERIA IN BLOOD CULTURES FROM CLINICALLY ILL CAPTIVE ANTILLEAN MANATEES (TRICHECHUS MANATUS MANATUS).

PubMed

Silva, Mariana C O; Attademo, Fernanda F L; Freire, Augusto C B; Sousa, Glaucia P; Luna, Fábia O; Lima, Débora C V; Mota, Rinaldo A; Mendes, Emiko S; Silva, Jean C R

2017-03-01

Between September 2001 and March 2013, 62 bacterial cultures (37 aerobic and 25 anaerobic) were performed on 37 blood samples from 23 Antillean manatees ( Trichechus manatus manatus) that were kept in captivity at the Brazilian National Center for Research and Conservation of Aquatic Mammals (CMA) in Pernambuco (CMA-PE) and Alagoas (CMA-AL), Brazil. All of the animals sampled exhibited clinical signs at the time of sampling including abscesses (n = 8), debilitation and anorexia (n = 22), and profound lethargy-moribundity (n = 7). The 4 animals with profound lethargy-moribundity died shortly after sampling of unknown causes. Bacteria were isolated from 15/37 (40.5%) and aerobic blood cultures from 13/23 animals (56.5%). None of the anaerobic cultures were positive. Aeromonas caviae , Aeromonas hydrophila , Aeromonas sp., Escherichia coli , Leclercia adecarboxylata , Pantoea agglomerans , Pseudomonas aeruginosa , Pseudomonas stutzeri , Pseudomonas sp., Sphingomonas paucimobilis , coagulase-negative Staphylococcus, and Staphylococcus epidermidis were each found in only one animal; Staphylococcus spp. was found in two; and Vibrio fluvialis in four. Thirteen samples had only one bacteria isolated, one sample had two bacteria, and one sample had three bacteria isolated. Regarding sex, age group, and origin among the manatees examined, 54.5% (6/11) of the females, 58.3% (7/12) of the males, 40% (2/5) of the calves, 66.7% (8/12) of the juveniles, 50% (3/6) of the adults, 55.5% (10/18) at CMA-PE, and 60% (3/5) at CMA-AL were found to be positive for bacterial growth during at least one sampling time. All Antillean manatees were clinically ill. Regarding clinical signs, bacteria were found in 50% (11/22) of blood samples of the animals showing debilitation and anorexia, 1 of 8 (12.5%) of blood samples of the animals showing abscesses, and 3 of 7 (42.9%) of blood samples of the animals showing profound lethargy-moribundity.

Films of Bacteria at Interfaces (FBI): Remodeling of Fluid Interfaces by Pseudomonas aeruginosa.

PubMed

Niepa, Tagbo H R; Vaccari, Liana; Leheny, Robert L; Goulian, Mark; Lee, Daeyeon; Stebe, Kathleen J

2017-12-19

Bacteria at fluid interfaces endure physical and chemical stresses unique to these highly asymmetric environments. The responses of Pseudomonas aeruginosa PAO1 and PA14 to a hexadecane-water interface are compared. PAO1 cells form elastic films of bacteria, excreted polysaccharides and proteins, whereas PA14 cells move actively without forming an elastic film. Studies of PAO1 mutants show that, unlike solid-supported biofilms, elastic interfacial film formation occurs in the absence of flagella, pili, or certain polysaccharides. Highly induced genes identified in transcriptional profiling include those for putative enzymes and a carbohydrate metabolism enzyme, alkB2; this latter gene is not upregulated in PA14 cells. Notably, PAO1 mutants lacking the alkB2 gene fail to form an elastic layer. Rather, they form an active film like that formed by PA14. These findings demonstrate that genetic expression is altered by interfacial confinement, and suggest that the ability to metabolize alkanes may play a role in elastic film formation at oil-water interfaces.

Malpighian tubules are important determinants of Pseudomonas transstadial transmission and longtime persistence in Anopheles stephensi.

PubMed

Chavshin, Ali Reza; Oshaghi, Mohammad Ali; Vatandoost, Hasan; Yakhchali, Bagher; Zarenejad, Fahimeh; Terenius, Olle

2015-01-21

Pseudomonas is a genus of bacteria commonly found in investigations of gut microbes in malaria mosquitoes. Among those mosquitoes is the dominating malaria vector in Asia, Anopheles stephensi, where Pseudomonas is a prevailing bacterium and natural inhabitant of its breeding places. In order to explore the reason for finding Pseudomonas so frequently, an investigation of its localization and transstadial properties was undertaken. A Pseudomonas isolate from An. stephensi was transformed successfully with an endogenous plasmid modified to express green fluorescent protein (GFP). Subsequently, the Pseudomonas-GFP was added to the laboratory larval breeding place of An. stephensi and taken up by the larvae. After 24 hours, the larvae were cleaned and moved to a bath with double-distilled water. Also, female adults were fed sugar solution containing Pseudomonas-GFP. The Pseudomonas-GFP was traced in the alimentary canal of larvae, pupae and adults. Fluorescent microscopy and PCR assays showed that the Pseudomonas bacteria underwent transstadial transmission from larvae to pupae and then to adults. In blood-fed female mosquitoes, the bacteria increased in numbers and remained in the mosquito body for at least three weeks after eclosion. In addition to the midgut, the Malpighian tubules of both larvae and adult mosquitoes were colonized by the bacteria. Also Pseudomonas-GFP that was distributed through sugar solution was able to colonize the Malpighian tubules of adult females. Colonization of the Malpighian tubules by Pseudomonas bacteria seems to be important for the transstadial passage from larvae to adult and presumably for the longevity of the bacteria in the adult mosquito. The existence of an entry point in the larval stage, and the long duration in the female gut, opens up for a possible use of Pseudomonas in mosquito paratransgenesis.

Enteric bacteria in aerobically digested sludge.

PubMed Central

Farrah, S R; Bitton, G

1984-01-01

Indicator bacteria, Salmonella spp., and total aerobic bacteria were determined in samples of undigested sludge and sludge that had been treated by one or two stages of aerobic digestion. Aerobic sludge digestion reduced the level of indicator bacteria by 1 to 2 log10 per g. The level of Salmonella spp. was also reduced during aerobic treatment of sludge. In general, aerobic treatment of sludge reduced, but did not eliminate, indicator bacteria and Salmonella spp. PMID:6721492

Identification and discrimination of Pseudomonas aeruginosa bacteria grown in blood and bile by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Rehse, Steven J.; Diedrich, Jonathan; Palchaudhuri, Sunil

2007-10-01

Pseudomonas aeruginosa bacteria colonies have been analyzed by laser-induced breakdown spectroscopy using nanosecond laser pulses. LIBS spectra were obtained after transferring the bacteria from a nutrient-rich culture medium to a nutrient-free agar plate for laser ablation. To study the dependence of the LIBS spectrum on growth and environmental conditions, colonies were cultured on three different nutrient media: a trypticase soy agar (TSA) plate, a blood agar plate, and a medium chosen deliberately to induce bacteria membrane changes, a MacConkey agar plate containing bile salts. Nineteen atomic and ionic emission lines in the LIBS spectrum, which was dominated by inorganic elements such as calcium, magnesium and sodium, were used to identify and classify the bacteria. A discriminant function analysis was used to discriminate between the P. aeruginosa bacteria and two strains of E. coli: a non-pathogenic environmental strain and the pathogenic strain enterohemorrhagic E. coli 0157:H7 (EHEC). Nearly identical spectra were obtained from P. aeruginosa grown on the TSA plate and the blood agar plate, while the bacteria grown on the MacConkey plate exhibited easily distinguishable differences from the other two. All P. aeruginosa samples, independent of initial growth conditions, were readily discriminated from the two E. coli strains.

Community Structure of Filamentous, Sheath-Building Sulfur Bacteria, Thioploca spp., off the Coast of Chile.

PubMed

Schulz, H N; Jorgensen, B B; Fossing, H A; Ramsing, N B

1996-06-01

The filamentous sulfur bacteria Thioploca spp. produce dense bacterial mats in the shelf area off the coast of Chile and Peru. The mat consists of common sheaths, shared by many filaments, that reach 5 to 10 cm down into the sediment. The structure of the Thioploca communities off the Bay of Concepcion was investigated with respect to biomass, species distribution, and three-dimensional orientation of the sheaths. Thioploca sheaths and filaments were found across the whole shelf area within the oxygen minimum zone. The maximum wet weight of sheaths, 800 g m(sup-2), was found at a depth of 90 m. The bacterial filaments within the sheaths contributed about 10% of this weight. The highest density of filaments was found within the uppermost 1 cm of the mat. On the basis of diameter classes, it was possible to distinguish populations containing only Thioploca spp. from mixed populations containing Beggiatoa spp. Three distinct size classes of Thioploca spp. were found, two of which have been described previously as Thioploca araucae and Thioploca chileae. Many Thioploca filaments did not possess a visible sheath, and about 20% of the sheaths contained more than one Thioploca species. The three-dimensional sheath structure showed that Thioploca filaments can move from the surface and deep into the sediment.

The Freshwater Sponge Ephydatia fluviatilis Harbours Diverse Pseudomonas Species (Gammaproteobacteria, Pseudomonadales) with Broad-Spectrum Antimicrobial Activity

PubMed Central

Keller-Costa, Tina; Jousset, Alexandre; van Overbeek, Leo; van Elsas, Jan Dirk; Costa, Rodrigo

2014-01-01

Bacteria are believed to play an important role in the fitness and biochemistry of sponges (Porifera). Pseudomonas species (Gammaproteobacteria, Pseudomonadales) are capable of colonizing a broad range of eukaryotic hosts, but knowledge of their diversity and function in freshwater invertebrates is rudimentary. We assessed the diversity, structure and antimicrobial activities of Pseudomonas spp. in the freshwater sponge Ephydatia fluviatilis. Polymerase Chain Reaction – Denaturing Gradient Gel Electrophoresis (PCR-DGGE) fingerprints of the global regulator gene gacA revealed distinct structures between sponge-associated and free-living Pseudomonas communities, unveiling previously unsuspected diversity of these assemblages in freshwater. Community structures varied across E. fluviatilis specimens, yet specific gacA phylotypes could be detected by PCR-DGGE in almost all sponge individuals sampled over two consecutive years. By means of whole-genome fingerprinting, 39 distinct genotypes were found within 90 fluorescent Pseudomonas isolates retrieved from E. fluviatilis. High frequency of in vitro antibacterial (49%), antiprotozoan (35%) and anti-oomycetal (32%) activities was found among these isolates, contrasting less-pronounced basidiomycetal (17%) and ascomycetal (8%) antagonism. Culture extracts of highly predation-resistant isolates rapidly caused complete immobility or lysis of cells of the protozoan Colpoda steinii. Isolates tentatively identified as P. jessenii, P. protegens and P. oryzihabitans showed conspicuous inhibitory traits and correspondence with dominant sponge-associated phylotypes registered by cultivation-independent analysis. Our findings suggest that E. fluviatilis hosts both transient and persistent Pseudomonas symbionts displaying antimicrobial activities of potential ecological and biotechnological value. PMID:24533086

The endogenous bacteria alter gut epithelial apoptosis and decrease mortality following Pseudomonas aeruginosa pneumonia

PubMed Central

Fox, Amy C.; McConnell, Kevin W.; Yoseph, Benyam P.; Breed, Elise; Liang, Zhe; Clark, Andrew T.; O'Donnell, David; Zee-Cheng, Brendan; Jung, Enjae; Dominguez, Jessica A.; Dunne, W. Michael; Burd, Eileen M.; Coopersmith, Craig M.

2012-01-01

The endogenous bacteria have been hypothesized to play a significant role in the pathophysiology of critical illness, although their role in sepsis is poorly understood. The purpose of this study was to determine how commensal bacteria alter the host response to sepsis. Conventional and germ free (GF) C57Bl/6 mice were subjected to Pseudomonas aeruginosa pneumonia. All GF mice died within two days while 44% of conventional mice survived for 7 days (p=0.001). Diluting the dose of bacteria 10-fold in GF mice led to similar survival in GF and conventional mice. When animals with similar mortality were assayed for intestinal integrity, GF mice had lower levels of intestinal epithelial apoptosis but similar levels of proliferation and intestinal permeability. GF mice had significantly lower levels of TNF and IL-1β in BAL fluid compared to conventional mice without changes in systemic cytokine production. Under conventional conditions, sepsis unmasks lymphocyte control of intestinal epithelial apoptosis, since sepsis induces a greater increase in gut apoptosis in Rag-1−/− mice than wild type (WT) mice. However, in a separate set of experiments, gut apoptosis was similar between septic GF Rag-1−/− mice and septic GF WT mice. These data demonstrate that the endogenous bacteria play a protective role in mediating mortality from pneumonia-induced sepsis, potentially mediated through altered intestinal apoptosis and the local pro-inflammatory response. Additionally, sepsis-induced lymphocyte-dependent increases in gut epithelial apoptosis appear to be mediated by the endogenous bacteria. PMID:23042193

The endogenous bacteria alter gut epithelial apoptosis and decrease mortality following Pseudomonas aeruginosa pneumonia.

PubMed

Fox, Amy C; McConnell, Kevin W; Yoseph, Benyam P; Breed, Elise; Liang, Zhe; Clark, Andrew T; O'Donnell, David; Zee-Cheng, Brendan; Jung, Enjae; Dominguez, Jessica A; Dunne, W Michael; Burd, Eileen M; Coopersmith, Craig M

2012-11-01

The endogenous bacteria have been hypothesized to play a significant role in the pathophysiology of critical illness, although their role in sepsis is poorly understood. The purpose of this study was to determine how commensal bacteria alter the host response to sepsis. Conventional and germ-free (GF) C57Bl/6 mice were subjected to Pseudomonas aeruginosa pneumonia. All GF mice died within 2 days, whereas 44% of conventional mice survived for 7 days (P = 0.001). Diluting the dose of bacteria 10-fold in GF mice led to similar survival in GF and conventional mice. When animals with similar mortality were assayed for intestinal integrity, GF mice had lower levels of intestinal epithelial apoptosis but similar levels of proliferation and intestinal permeability. Germ-free mice had significantly lower levels of tumor necrosis factor and interleukin 1β in bronchoalveolar lavage fluid compared with conventional mice without changes in systemic cytokine production. Under conventional conditions, sepsis unmasks lymphocyte control of intestinal epithelial apoptosis, because sepsis induces a greater increase in gut apoptosis in Rag-1 mice than in wild-type mice. However, in a separate set of experiments, gut apoptosis was similar between septic GF Rag-1 mice and septic GF wild-type mice. These data demonstrate that the endogenous bacteria play a protective role in mediating mortality from pneumonia-induced sepsis, potentially mediated through altered intestinal apoptosis and the local proinflammatory response. In addition, sepsis-induced lymphocyte-dependent increases in gut epithelial apoptosis appear to be mediated by the endogenous bacteria.

Differential sensitivity of polyhydroxyalkanoate producing bacteria to fermentation inhibitors and comparison of polyhydroxybutyrate production from Burkholderia cepacia and Pseudomonas pseudoflava.

PubMed

Dietrich, Diane; Illman, Barbara; Crooks, Casey

2013-06-04

The aim of this study is determine the relative sensitivity of a panel of seven polyhydroxyalkanoate producing bacteria to a panel of seven lignocellulosic-derived fermentation inhibitors representing aliphatic acids, furans and phenolics. A further aim was to measure the polyhydroxybutyrate production of select organisms on lignocellulosic-derived monosaccharides arabinose, xylose, glucose and mannose. We examined the sensitivity of seven polyhydroxyalkanoate producing bacteria: Azohydromonas lata, Bacillus megaterium, Bacillus cereus, Burkholderia cepacia, Pseudomonas olevorans, Pseudomonas pseudoflava and Ralstonia eutropha, against seven fermentation inhibitors produced by the saccharification of lignocellulose: acetic acid, levulinic acid, coumaric acid, ferulic acid, syringaldehyde, furfural, and hyroxymethyfurfural. There was significant variation in the sensitivity of these microbes to representative phenolics ranging from 0.25-1.5 g/L coumaric and ferulic acid and between 0.5-6.0 g/L syringaldehyde. Inhibition ranged from 0.37-4 g/L and 0.75-6 g/L with acetic acid and levulinic acid, respectively. B. cepacia and P. pseudoflava were selected for further analysis of polyhydroxyalkanoate production. We find significant differences in sensitivity to the fermentation inhibitors tested and find these variations to be over a relevant concentration range given the concentrations of inhibitors typically found in lignocellulosic hydrolysates. Of the seven bacteria tested, B. cepacia demonstrated the greatest inhibitor tolerance. Similarly, of two organisms examined for polyhydroxybutyrate production, B. cepacia was notably more efficient when fermenting pentose substrates.

Antagonistic intestinal microflora produces antimicrobial substance inhibitory to Pseudomonas species and other spoilage organisms.

PubMed

Hatew, Bayissa; Delessa, Tenagne; Zakin, Vered; Gollop, Natan

2011-10-01

Chicken intestine harbors a vast number of bacterial strains. In the present study, antimicrobial substance produced by lactic acid bacteria (LAB) isolated from the gastrointestinal tract of healthy chicken was detected, characterized, and purified. Based on 16S rRNA sequencing, the bacteria were identified as Lactobacillus plantarum vN. The antimicrobial substance produced by this bacterium was designated vN-1 and exhibited a broad-spectrum of activity against many important pathogenic and spoilage microorganisms, including Pseudomonas aeruginosa, Staphylococcus aureus, Micrococcus luteus, Salmonella Typhimurium, and Erwinia amylovova. vN-1 was determined to be thermostable, insensitive to pH values ranging from 2.0 to 8.0, resistant to various organic solvents and to enzymatic inactivation. The inhibition kinetics displayed a bactericidal mode of action. This study revealed an antimicrobial substance with low molecular mass of less than 1 kDa as determined by ultrafiltration and having features not previously reported for LAB isolated from chicken intestines. The detection of this antimicrobial substance addresses an important aspect of biotechnological control agents of spoilage caused by Pseudomonas spp. and promises the possibility for preservation of refrigerated poultry meat. Practical Application:  The newly characterized antimicrobial substance and designated as vN-1 may have the potential to be used in food preservation. © 2011 Institute of Food Technologists®

Fungal Disease Prevention in Seedlings of Rice (Oryza sativa) and Other Grasses by Growth-Promoting Seed-Associated Endophytic Bacteria from Invasive Phragmites australis

PubMed Central

Verma, Satish K.; Kingsley, Kathryn L.; Bergen, Marshall S.; White, James F.

2018-01-01

Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium, Pythium and other water moulds cause seed rots during germination. Fusarium blights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass (Cynodon dactylon), or annual bluegrass (Poa annua) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum. We found that three bacteria belonging to genus Pseudomonas spp. (SLB4-P. fluorescens, SLB6-Pseudomonas sp. and SY1-Pseudomonas sp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum, 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production suggested presence of

Fungal Disease Prevention in Seedlings of Rice (Oryza sativa) and Other Grasses by Growth-Promoting Seed-Associated Endophytic Bacteria from Invasive Phragmites australis.

PubMed

Verma, Satish K; Kingsley, Kathryn L; Bergen, Marshall S; Kowalski, Kurt P; White, James F

2018-03-08

Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium , Pythium and other water moulds cause seed rots during germination. Fusarium blights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass ( Cynodon dactylon ), or annual bluegrass ( Poa annua ) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum . We found that three bacteria belonging to genus Pseudomonas spp. (SLB4- P. fluorescens , SLB6- Pseudomonas sp. and SY1- Pseudomonas sp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum , 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production suggested

Correlation between antibiotic and biocide resistance in mesophilic and psychrotrophic Pseudomonas spp. isolated from slaughterhouse surfaces throughout meat chain production.

PubMed

Lavilla Lerma, Leyre; Benomar, Nabil; Casado Muñoz, María del Carmen; Gálvez, Antonio; Abriouel, Hikmate

2015-10-01

The aim of this study was to evaluate biocide susceptibility in mesophilic and psychrotrophic pseudomonads isolated from surfaces of a goat and lamb slaughterhouse, which was representative of the region. To determine biocide resistance in pseudomonads, we determined for the first time the epidemiological cut-off values (ECOFFs) of benzalkonium, cetrimide, chlorhexidine, hexachlorophene, P3 oxonia, polyhexamethylene guanidine hydrochloride (PHMG), topax 66 and triclosan being generally very similar in different Pseudomonas spp. with some exceptions. Thus, resistance of pseudomonads was mainly shown to triclosan, and in lesser extent to cetrimide and benzalkonium chloride depending on the species, however they were highly susceptible to industrial formulations of biocides. By means of statistical analysis, positive correlations between antibiotics, biocides and both antimicrobials in pseudomonads were detected suggesting a co- or cross resistance between different antimicrobials in goat and lamb slaughterhouse environment. Cross-resistance between biocides and antibiotics in pseudomonads were especially detected between PHMG or triclosan and different antibiotics depending on the biocide and the population type. Thus, the use of those biocides as disinfectant in slaughterhouse zones must be carefully evaluated because of the selection pressure effect of antimicrobials on the emergence of resistant bacteria which could be spread to the consumer. It is noteworthy that specific industrial formulations such as topax 66 and oxonia P3 showed few correlations with antibiotics (none or 1-2 antibiotics) which should be taken into consideration for disinfection practices in goat and lamb slaughterhouse. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterization of the Biodiversity of the Spoilage Microbiota in Chicken Meat Using Next Generation Sequencing and Culture Dependent Approach.

PubMed

Lee, Hee Soo; Kwon, Mirae; Heo, Sunhak; Kim, Min Gon; Kim, Geun-Bae

2017-01-01

This study investigated the psychrotrophic bacteria isolated from chicken meat to characterize their microbial composition during refrigerated storage. The bacterial community was identified by the Illumina MiSeq method based on bacterial DNA extracted from spoiled chicken meat. Molecular identification of the isolated psychrotrophic bacteria was carried out using 16S rDNA sequencing and their putrefactive potential was investigated by the growth at low temperature as well as their proteolytic activities in chicken meat. From the Illumina sequencing, a total of 187,671 reads were obtained from 12 chicken samples. Regardless of the type of chicken meat (i.e., whole meat and chicken breast) and storage temperatures (4°C and 10°C), Pseudomonas weihenstephanensis and Pseudomonas congelans were the most prominent bacterial species. Serratia spp. and Acinetobacter spp. were prominent in chicken breast and whole chicken meat, respectively. The 118 isolated strains of psychrotrophic bacteria comprised Pseudomonas spp. (58.48%), Serratia spp. (10.17%), and Morganella spp. (6.78%). All isolates grew well at 10°C and they induced different proteolytic activities depending on the species and strains. Parallel analysis of the next generation sequencing and culture dependent approach provides in-depth information on the biodiversity of the spoilage microbiota in chicken meat. Further study is needed to develop better preservation methods against these spoilage bacteria.

Evidence for a role of biosurfactants produced by Pseudomonas fluorescens in the spoilage of fresh aerobically stored chicken meat.

PubMed

Mellor, Glen E; Bentley, Jessica A; Dykes, Gary A

2011-08-01

Fresh chicken meat is a fat-rich environment and we therefore hypothesised that production of biosurfactants to increase bioavailability of fats may represent one way in which spoilage bacteria might enhance the availability of nutrients. Numbers of Pseudomonas were determined on a total of 20 fresh and 20 spoiled chicken thighs with skin. A total of 400 randomly isolated Pseudomonas colonies from fresh (200) and spoiled (200) chicken were screened for the presence of biosurfactant production. Biosurfactant producing strains represented 5% and 72% of the Pseudomonas spp. isolates from fresh (mean count 2.3 log(10) cfu g(-1)) and spoiled (mean count 7.4 log(10) cfu g(-1)) chicken skin, respectively. Partially-purified biosurfactants derived from a subgroup of four Pseudomonasfluorescens strains obtained through the screening process were subsequently used to investigate the role that the addition of these compounds plays in the spoilage of aerobically stored chicken. Emulsification potential of the four selected biosurfactants was measured against a range of hydrocarbons and oils. All four biosurfactants displayed a greater ability to emulsify rendered chicken fat than hydrocarbons (paraffin liquid, toluene and hexane) and oils (canola, olive, sunflower and vegetable). Storage trials (4 °C) of chicken meat treated with the four selected biosurfactants revealed a significantly greater (P < 0.05) total aerobic count in biosurfactant treated samples, as compared to untreated samples on each day (0, 1, 2, 3) of storage. For biosurfactant treated samples the greatest increase in total aerobic count (1.3-1.7 log(10) cfu g(-1)) occurred following one day of incubation. These results indicate that biosurfactants produced by Pseudomonas spp. may play an important role in the spoilage of aerobically stored chicken meat by making nutrients more freely available and providing strains producing them with a competitive advantage. Copyright © 2011 Elsevier Ltd. All rights

Does the presence of bacteria effect basaltic glass dissolution rates? 1: Dead Pseudomonas reactants

NASA Astrophysics Data System (ADS)

Stockmann, Gabrielle J.; Shirokova, Liudmila S.; Pokrovsky, Oleg S.; Oelkers, Eric H.; Benezeth, Pascale

2010-05-01

Basaltic glass and crystalline basalt formations in Iceland have been suggested for industrial CO2 storage due to their porous and permeable properties and high reactivity. Acid CO2-saturated waters in contact with basaltic glass will lead to rapid dissolution of the glass and release of divalent cations, (Ca2+, Mg2+, Fe2+) that can react to form stable carbonates and thereby trap the CO2. However, the basalt formations in Iceland not only contains glass and mineral assemblages, but also host microbiological communities that either by their presence or by active involvement in chemical reactions could affect the amount of basaltic glass being dissolved and CO2 being trapped. Samples of natural bacteria communities from the CO2 storage grounds in Iceland were collected, separated, and purified using agar plate technique and cultured under laboratory conditions in nutrient broth-rich media. Heterotrophic aerobic Gram-negative strain of Pseudomonas reactants was selected for a series of flow-through experiments aimed at evaluation of basaltic glass dissolution rate in the presense of increasing amounts of dead bacteria and their lysis products. The experiments were carried out using mixed-flow reactors at pH 4, 6, 8 and 10 at 25 °C. Each of the four reactors contained 1 gram of basaltic glass of the size fraction 45-125 μm. This glass was dissolved in ~ 0.01 M buffer solutions (acetate, MES, bicarbonate and carbonate+bicarbonate mixture) of the desired pH. All experiments ran 2 months, keeping the flowrate and temperature stable and only changing the concentration of dead bacteria in the inlet solutions (from 0 to 430 mg/L). Experiments were performed in sterile conditions, and bacterial growth was prevented by adding NaN3 to the inlet solutions. Routine culturing of bacteria on the agar plates confirmed the sterility of experiments. Samples of outlet solutions were analyzed for major cations and trace elements by ICP-MS. Results demonstrate a slight decrease in the

Discovery, research, and development of new antibiotics: the WHO priority list of antibiotic-resistant bacteria and tuberculosis.

PubMed

Tacconelli, Evelina; Carrara, Elena; Savoldi, Alessia; Harbarth, Stephan; Mendelson, Marc; Monnet, Dominique L; Pulcini, Céline; Kahlmeter, Gunnar; Kluytmans, Jan; Carmeli, Yehuda; Ouellette, Marc; Outterson, Kevin; Patel, Jean; Cavaleri, Marco; Cox, Edward M; Houchens, Chris R; Grayson, M Lindsay; Hansen, Paul; Singh, Nalini; Theuretzbacher, Ursula; Magrini, Nicola

2018-03-01

The spread of antibiotic-resistant bacteria poses a substantial threat to morbidity and mortality worldwide. Due to its large public health and societal implications, multidrug-resistant tuberculosis has been long regarded by WHO as a global priority for investment in new drugs. In 2016, WHO was requested by member states to create a priority list of other antibiotic-resistant bacteria to support research and development of effective drugs. We used a multicriteria decision analysis method to prioritise antibiotic-resistant bacteria; this method involved the identification of relevant criteria to assess priority against which each antibiotic-resistant bacterium was rated. The final priority ranking of the antibiotic-resistant bacteria was established after a preference-based survey was used to obtain expert weighting of criteria. We selected 20 bacterial species with 25 patterns of acquired resistance and ten criteria to assess priority: mortality, health-care burden, community burden, prevalence of resistance, 10-year trend of resistance, transmissibility, preventability in the community setting, preventability in the health-care setting, treatability, and pipeline. We stratified the priority list into three tiers (critical, high, and medium priority), using the 33rd percentile of the bacterium's total scores as the cutoff. Critical-priority bacteria included carbapenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa, and carbapenem-resistant and third-generation cephalosporin-resistant Enterobacteriaceae. The highest ranked Gram-positive bacteria (high priority) were vancomycin-resistant Enterococcus faecium and meticillin-resistant Staphylococcus aureus. Of the bacteria typically responsible for community-acquired infections, clarithromycin-resistant Helicobacter pylori, and fluoroquinolone-resistant Campylobacter spp, Neisseria gonorrhoeae, and Salmonella typhi were included in the high-priority tier. Future development strategies should focus on

Small-Molecule Inhibition of Choline Catabolism in Pseudomonas aeruginosa and Other Aerobic Choline-Catabolizing Bacteria ▿ †

PubMed Central

Fitzsimmons, Liam F.; Flemer, Stevenson; Wurthmann, A. Sandy; Deker, P. Bruce; Sarkar, Indra Neil; Wargo, Matthew J.

2011-01-01

Choline is abundant in association with eukaryotes and plays roles in osmoprotection, thermoprotection, and membrane biosynthesis in many bacteria. Aerobic catabolism of choline is widespread among soil proteobacteria, particularly those associated with eukaryotes. Catabolism of choline as a carbon, nitrogen, and/or energy source may play important roles in association with eukaryotes, including pathogenesis, symbioses, and nutrient cycling. We sought to generate choline analogues to study bacterial choline catabolism in vitro and in situ. Here we report the characterization of a choline analogue, propargylcholine, which inhibits choline catabolism at the level of Dgc enzyme-catalyzed dimethylglycine demethylation in Pseudomonas aeruginosa. We used genetic analyses and 13C nuclear magnetic resonance to demonstrate that propargylcholine is catabolized to its inhibitory form, propargylmethylglycine. Chemically synthesized propargylmethylglycine was also an inhibitor of growth on choline. Bioinformatic analysis suggests that there are genes encoding DgcA homologues in a variety of proteobacteria. We examined the broader utility of propargylcholine and propargylmethylglycine by assessing growth of other members of the proteobacteria that are known to grow on choline and possess putative DgcA homologues. Propargylcholine showed utility as a growth inhibitor in P. aeruginosa but did not inhibit growth in other proteobacteria tested. In contrast, propargylmethylglycine was able to inhibit choline-dependent growth in all tested proteobacteria, including Pseudomonas mendocina, Pseudomonas fluorescens, Pseudomonas putida, Burkholderia cepacia, Burkholderia ambifaria, and Sinorhizobium meliloti. We predict that chemical inhibitors of choline catabolism will be useful for studying this pathway in clinical and environmental isolates and could be a useful tool to study proteobacterial choline catabolism in situ. PMID:21602374

Interactions between yeasts and bacteria in the smear surface-ripened cheeses.

PubMed

Corsetti, A; Rossi, J; Gobbetti, M

2001-09-19

In the initial phase of ripening, the microflora of bacterial smear surface-ripened cheeses such as Limburger, Taleggio, Brick, Münster and Saint-Paulin and that of surface mould-ripened cheeses such as Camembert and Brie may be similar, but at the end of the ripening, bacteria such as Brevibacterium spp., Arthrobacter spp., Micrococcus spp., Corynebacterium spp. and moulds such as Penicillium camemberti are, respectively, the dominant microorganisms. Yeasts such as Candida spp., Cryptococcus spp., Debaryomyces spp., Geotrichum candidum, Pichia spp., Rhodotorula spp., Saccharomyces spp. and Yarrowia lipolytica are often and variably isolated from the smear surface-ripened cheeses. Although not dominant within the microorganisms of the smear surface-ripened cheeses, yeasts establish significant interactions with moulds and especially bacteria, including surface bacteria and lactic acid bacteria. Some aspects of the interactions between yeasts and bacteria in such type of cheeses are considered in this paper.

Characterization of tetracycline-resistant bacteria in an urbanizing subtropical watershed.

PubMed

Sullivan, B A; Gentry, T; Karthikeyan, R

2013-09-01

The objective of this study was to determine whether varying levels of urbanization influence the dominant bacterial species of mildly resistant (0·03 mmol l(-1) tetracycline) and highly resistant (0·06 mmol l(-1) tetracycline) bacteria in sediment and water. Also, the level of urbanization was further evaluated to determine whether the diversity of tetracycline resistance genes present in the isolates and the capability of transferring their resistance were influenced. Sediment and water samples collected from five sampling sites were plated in triplicate on nutrient agar plates with a mild dose (0·03 mmol l(-1) ) and a high dose (0·06 mmol l(-1) ) of tetracycline. Five colonies from each plate plus an additional five from each triplicate group were randomly selected and isolated on nutrient agar containing 0·03 mmol l(-1) tetracycline (400 isolates). The isolates were identified by 16S rRNA gene sequencing and comparison to GenBank using blast. The isolates were also screened for 15 tetracycline resistance genes using a multiplex PCR assay and their ability to transfer resistance through conjugation experiments using a kanamycin-resistant Escherichia. coli K-12 strain labelled with a green fluorescent protein gene. Results from this study indicate that the dominant resistant organisms in this watershed are Acinetobacter spp., Chryseobacterium spp., Serratia spp., Pseudomonas spp., Aeromonas spp. and E. coli. All of these organisms are Gram negative and are closely related to pathogenic species. A majority of the isolates (66%) were capable of transferring their resistance, and there was a greater incidence of tet resistance transfer with increasing urbanization. Also, it was determined that the dominant resistance genes in the watershed are tet(W) and tet(A). Urbanization significantly affected dominant tetracycline-resistant bacteria species, but did not affect dominant resistance genes. There was correlation between increased urbanization with an

Coexistence of Burkholderia, Cupriavidus, and Rhizobium sp. nodule bacteria on two Mimosa spp. in Costa Rica.

PubMed

Barrett, Craig F; Parker, Matthew A

2006-02-01

rRNA gene sequencing and PCR assays indicated that 215 isolates of root nodule bacteria from two Mimosa species at three sites in Costa Rica belonged to the genera Burkholderia, Cupriavidus, and Rhizobium. This is the first report of Cupriavidus sp. nodule symbionts for Mimosa populations within their native geographic range in the neotropics. Burkholderia spp. predominated among samples from Mimosa pigra (86% of isolates), while there was a more even distribution of Cupriavidus, Burkholderia, and Rhizobium spp. on Mimosa pudica (38, 37, and 25% of isolates, respectively). All Cupriavidus and Burkholderia genotypes tested formed root nodules and fixed nitrogen on both M. pigra and M. pudica, and sequencing of rRNA genes in strains reisolated from nodules verified identity with inoculant strains. Inoculation tests further indicated that both Cupriavidus and Burkholderia spp. resulted in significantly higher plant growth and nodule nitrogenase activity (as measured by acetylene reduction assays) relative to plant performance with strains of Rhizobium. Given the prevalence of Burkholderia and Cupriavidus spp. on these Mimosa legumes and the widespread distribution of these plants both within and outside the neotropics, it is likely that both beta-proteobacterial genera are more ubiquitous as root nodule symbionts than previously believed.

Coexistence of Burkholderia, Cupriavidus, and Rhizobium sp. Nodule Bacteria on two Mimosa spp. in Costa Rica

PubMed Central

Barrett, Craig F.; Parker, Matthew A.

2006-01-01

rRNA gene sequencing and PCR assays indicated that 215 isolates of root nodule bacteria from two Mimosa species at three sites in Costa Rica belonged to the genera Burkholderia, Cupriavidus, and Rhizobium. This is the first report of Cupriavidus sp. nodule symbionts for Mimosa populations within their native geographic range in the neotropics. Burkholderia spp. predominated among samples from Mimosa pigra (86% of isolates), while there was a more even distribution of Cupriavidus, Burkholderia, and Rhizobium spp. on Mimosa pudica (38, 37, and 25% of isolates, respectively). All Cupriavidus and Burkholderia genotypes tested formed root nodules and fixed nitrogen on both M. pigra and M. pudica, and sequencing of rRNA genes in strains reisolated from nodules verified identity with inoculant strains. Inoculation tests further indicated that both Cupriavidus and Burkholderia spp. resulted in significantly higher plant growth and nodule nitrogenase activity (as measured by acetylene reduction assays) relative to plant performance with strains of Rhizobium. Given the prevalence of Burkholderia and Cupriavidus spp. on these Mimosa legumes and the widespread distribution of these plants both within and outside the neotropics, it is likely that both β-proteobacterial genera are more ubiquitous as root nodule symbionts than previously believed. PMID:16461667

Combined inoculation of Pseudomonas fluorescens and Trichoderma harzianum for enhancing plant growth of vanilla (Vanilla planifolia).

PubMed

Sandheep, A R; Asok, A K; Jisha, M S

2013-06-15

This study was conducted to evaluate the plant growth promoting efficiency of combined inoculation of rhizobacteria on Vanilla plants. Based on the in vitro performance of indigenous Trichoderma spp. and Pseudomonas spp., four effective antagonists were selected and screened under greenhouse experiment for their growth enhancement potential. The maximum percentage of growth enhancement were observed in the combination of Trichoderma harzianum with Pseudomonas fluorescens treatment followed by Pseudomonas fluorescens, Trichoderma harzianum, Pseudomonas putida and Trichoderma virens, respectively in decreasing order. Combined inoculation of Trichoderma harzianum and Pseudomonas fluorescens registered the maximum length of vine (82.88 cm), highest number of leaves (26.67/plant), recorded the highest fresh weight of shoots (61.54 g plant(-1)), fresh weight of roots (4.46 g plant(-1)) and dry weight of shoot (4.56 g plant(-1)) where as the highest dry weight of roots (2.0806 g plant(-1)) were achieved with treatments of Pseudomonas fluorescens. Among the inoculated strains, combined inoculation of Trichoderma harzianum and Pseudomonas fluorescens recorded the maximum nitrogen uptake (61.28 mg plant(-1)) followed by the combined inoculation of Trichoderma harzianum (std) and Pseudomonas fluorescens (std) (55.03 mg plant(-1)) and the highest phosphorus uptake (38.80 mg plant(-1)) was recorded in dual inoculation of Trichoderma harzianum and Pseudomonas fluorescens.

Differential sensitivity of polyhydroxyalkanoate producing bacteria to fermentation inhibitors and comparison of polyhydroxybutyrate production from Burkholderia cepacia and Pseudomonas pseudoflava

PubMed Central

2013-01-01

Background The aim of this study is determine the relative sensitivity of a panel of seven polyhydroxyalkanoate producing bacteria to a panel of seven lignocellulosic-derived fermentation inhibitors representing aliphatic acids, furans and phenolics. A further aim was to measure the polyhydroxybutyrate production of select organisms on lignocellulosic-derived monosaccharides arabinose, xylose, glucose and mannose. Findings We examined the sensitivity of seven polyhydroxyalkanoate producing bacteria: Azohydromonas lata, Bacillus megaterium, Bacillus cereus, Burkholderia cepacia, Pseudomonas olevorans, Pseudomonas pseudoflava and Ralstonia eutropha, against seven fermentation inhibitors produced by the saccharification of lignocellulose: acetic acid, levulinic acid, coumaric acid, ferulic acid, syringaldehyde, furfural, and hyroxymethyfurfural. There was significant variation in the sensitivity of these microbes to representative phenolics ranging from 0.25-1.5 g/L coumaric and ferulic acid and between 0.5-6.0 g/L syringaldehyde. Inhibition ranged from 0.37-4 g/L and 0.75-6 g/L with acetic acid and levulinic acid, respectively. B. cepacia and P. pseudoflava were selected for further analysis of polyhydroxyalkanoate production. Conclusions We find significant differences in sensitivity to the fermentation inhibitors tested and find these variations to be over a relevant concentration range given the concentrations of inhibitors typically found in lignocellulosic hydrolysates. Of the seven bacteria tested, B. cepacia demonstrated the greatest inhibitor tolerance. Similarly, of two organisms examined for polyhydroxybutyrate production, B. cepacia was notably more efficient when fermenting pentose substrates. PMID:23734728

Draft Genome Sequence of the Marine Bacterium Pseudomonas aestusnigri VGXO14T.

PubMed

Gomila, Margarita; Mulet, Magdalena; Lalucat, Jorge; García-Valdés, Elena

2017-08-10

The type strain of Pseudomonas aestusnigri (VGXO14), isolated from a crude oil-polluted marine sand sample, is a member of the P. pertucinogena phylogenetic group. Here, we report the genome sequence (3.83 Mb) of P. aestusnigri to gain insights into the biology and taxonomy of marine Pseudomonas spp. adapted to polluted marine habitats. Copyright © 2017 Gomila et al.

Draft Genome Sequence of the Marine Bacterium Pseudomonas aestusnigri VGXO14T

PubMed Central

2017-01-01

ABSTRACT The type strain of Pseudomonas aestusnigri (VGXO14), isolated from a crude oil-polluted marine sand sample, is a member of the P. pertucinogena phylogenetic group. Here, we report the genome sequence (3.83 Mb) of P. aestusnigri to gain insights into the biology and taxonomy of marine Pseudomonas spp. adapted to polluted marine habitats. PMID:28798177

[Isolation of Listeria spp., Aeromonas spp., and Vibrio spp. from seafood products].

PubMed

Scoglio, M E; Di Pietro, A; Mauro, A; Picerno, I; Laganà, P; Delia, S A

2000-01-01

Forty-one strains of Listeria, Aeromonas and Vibrio have been isolated in 71 samples of seafood, both raw and ready to eat and frozen. L. monocytogenes, detected by PCR also, is found in the smoked salmon only. Aeromonas spp. and Vibrio spp. are isolated in the raw products (shrimps and shellfish). No relationship is found between the presence of such microrganisms and the common indicator bacteria. Finally, the health hazard related to strong contamination and the need to diversify the food safety assurance programmes, for the various products, are underlined.

Endophytic bacterial flora in root and stem tissues of black pepper (Piper nigrum L.) genotype: isolation, identification and evaluation against Phytophthora capsici.

PubMed

Aravind, R; Kumar, A; Eapen, S J; Ramana, K V

2009-01-01

To isolate and identify black pepper (Piper nigrum L) associated endophytic bacteria antagonistic to Phytophthora capsici causing foot rot disease. Endophytic bacteria (74) were isolated, characterized and evaluated against P. capsici. Six genera belong to Pseudomonas spp (20 strains), Serratia (1 strain), Bacillus spp. (22 strains), Arthrobacter spp. (15 strains), Micrococcus spp. (7 strains), Curtobacterium sp. (1 strain) and eight unidentified strains were isolated from internal tissues of root and stem. Three isolates, IISRBP 35, IISRBP 25 and IISRBP 17 were found effective for Phytophthora suppression in multilevel screening assays which recorded over 70% disease suppression in greenhouse trials. A species closest match (99% similarity) of IISRBP 35 was established as Pseudomonas aeruginosa (Pseudomonas EF568931), IISRBP 25 as P. putida (Pseudomonas EF568932), and IISRBP 17 as Bacillus megaterium (B. megaterium EU071712) based on 16S rDNA sequencing. Black pepper associated P. aeruginosa, P. putida and B. megaterium were identified as effective antagonistic endophytes for biological control of Phytophthora foot rot in black pepper. This work provides the first evidence for endophytic bacterial diversity in black pepper stem and roots, with biocontrol potential against P. capsici infection.

Identification of CtpL as a chromosomally encoded chemoreceptor for 4-chloroaniline and catechol in Pseudomonas aeruginosa PAO1.

PubMed

Vangnai, Alisa S; Takeuchi, Kazuki; Oku, Shota; Kataoka, Naoya; Nitisakulkan, Tisana; Tajima, Takahisa; Kato, Junichi

2013-12-01

Bacterial chemotaxis influences the ability of bacteria to survive and thrive in most environments, including polluted ones. Despite numerous reports of the phenotypic characterization of chemotactic bacteria, only a few molecular details of chemoreceptors for aromatic pollutants have been described. In this study, the molecular basis of chemotaxis toward an environmentally toxic chlorinated aromatic pollutant, 4-chloroaniline (4CA), was evaluated. Among the three Pseudomonas spp. tested, Pseudomonas aeruginosa PAO1 exhibited positive chemotaxis both to the nonmetabolizable 4CA, where 4-chloroacetanilide was formed as a dead-end transformation product, and to the metabolizable catechol. Molecular analysis of all 26 mutants with a disrupted methyl-accepting chemotaxis gene revealed that CtpL, a chromosomally encoded chemoreceptor, was responsible for the positive chemotactic response toward 4CA. Since CtpL has previously been described to be a major chemoreceptor for inorganic phosphate at low concentrations in PAO1, this report describes a fortuitous ability of CtpL to function toward aromatic pollutants. In addition, its regulation not only was dependent on the presence of the chemoattractant inducer but also was regulated by conditions of phosphate starvation. These results expand the range of known chemotactic transducers and their function in the environmental bacterium PAO1.

Widespread Fosfomycin Resistance in Gram-Negative Bacteria Attributable to the Chromosomal fosA Gene

PubMed Central

Ito, Ryota; Tomich, Adam D.; Callaghan, Jake D.; McElheny, Christi L.; Mettus, Roberta T.; Sluis-Cremer, Nicolas

2017-01-01

ABSTRACT Fosfomycin is a decades-old antibiotic which is being revisited because of its perceived activity against many extensively drug-resistant Gram-negative pathogens. FosA proteins are Mn2+ and K+-dependent glutathione S-transferases which confer fosfomycin resistance in Gram-negative bacteria by conjugation of glutathione to the antibiotic. Plasmid-borne fosA variants have been reported in fosfomycin-resistant Escherichia coli strains. However, the prevalence and distribution of fosA in other Gram-negative bacteria are not known. We systematically surveyed the presence of fosA in Gram-negative bacteria in over 18,000 published genomes from 18 Gram-negative species and investigated their contribution to fosfomycin resistance. We show that FosA homologues are present in the majority of genomes in some species (e.g., Klebsiella spp., Enterobacter spp., Serratia marcescens, and Pseudomonas aeruginosa), whereas they are largely absent in others (e.g., E. coli, Acinetobacter baumannii, and Burkholderia cepacia). FosA proteins in different bacterial pathogens are highly divergent, but key amino acid residues in the active site are conserved. Chromosomal fosA genes conferred high-level fosfomycin resistance when expressed in E. coli, and deletion of chromosomal fosA in S. marcescens eliminated fosfomycin resistance. Our results indicate that FosA is encoded by clinically relevant Gram-negative species and contributes to intrinsic fosfomycin resistance. PMID:28851843

Lactic acid bacteria from chicken carcasses with inhibitory activity against Salmonella spp. and Listeria monocytogenes.

PubMed

Sakaridis, I; Soultos, N; Dovas, C I; Papavergou, E; Ambrosiadis, I; Koidis, P

2012-02-01

This study was conducted to isolate psychrotrophic lactic acid bacteria (LAB) from chicken carcasses with inhibitory activity against strains of Salmonella spp. and Listeria monocytogenes. A total of 100 broiler samples were examined for the presence of LAB. Ninety-two LAB isolates that showed antimicrobial effects against Salmonella spp. and L. monocytogenes were further analysed to examine their LAB (Gram-positive, catalase negative, oxidase negative) and psychrotrophic characteristics (ability to grow at 7 °C). Fifty isolates were further selected and identified initially using standard biochemical tests in miniature (Micro-kits API CH 50) and then by sequencing of the 16s-23s rRNA gene boundary region (Intergenic Spacer Region). By molecular identification, these isolates were classified into 5 different LAB species: Lactobacillus salivarius, Lactobacillus reuteri, Lactobacillus johnsonii, Pediococcus acidilactici, and Lactobacillus paralimentarius. None of the isolates produced tyramine or histamine. Copyright © 2011 Elsevier Ltd. All rights reserved.

Unique Bacteria Community Composition and Co-occurrence in the Milk of Different Ruminants

PubMed Central

Li, Zhipeng; Wright, André-Denis G.; Yang, Yifeng; Si, Huazhe; Li, Guangyu

2017-01-01

Lactation provides the singular source of nourishment to the offspring of mammals. This nutrition source also contains a diverse microbiota affecting the development and health of the newborn. Here, we examined the milk microbiota in water deer (Hydropotes inermis, the most primitive member of the family Cervidae), reindeer (Rangifer tarandus, the oldest semi-domesticated cervid), and the dairy goat (Capra aegagrus, member of the family Bovidae), to determine if common milk microbiota species were present across all three ruminant species. The results showed that water deer had the highest bacterial diversity, followed by reindeer, and then goat. Unifrac distance and correspondence analyses revealed that water deer harbored an increased abundance of Pseudomonas spp. and Acinetobacter spp., while milk from reindeer and goat was dominated by unclassified bacteria from the family Hyphomicrobiaceae and Bacillus spp., respectively. These data indicate significant differences in the composition of milk-based bacterial communities. The presence of Halomonas spp. in three distinct co-occurrence networks of bacterial interactions revealed both common and unique features in milk niches. These results suggest that the milk of water deer and reindeer harbor unique bacterial communities compared with the goat, which might reflect host microbial adaptation caused by evolution. PMID:28098228

Chemical composition and antimicrobial activity of Cymbopogon nardus citronella essential oil against systemic bacteria of aquatic animals.

PubMed

Wei, Lee Seong; Wee, Wendy

2013-06-01

This paper describes chemical composition and antimicrobial activity of Cymbopogon nardus citronella essential oil against Edwardsiella spp. (n = 21), Vibrio spp. (n = 6), Aeromonas spp. (n = 2), Escherichia coli (n = 2), Salmonella spp. (n = 2), Flavobacterium spp. (n = 1), Pseudomonas spp. (n = 1) and Streptococcus spp. (n = 1) isolated from internal organs of aquatic animals. Due to the ban of antibiotics for aquaculture use, this study was carried out to evaluate the potential of citronella essential oil as alternative to commercial antibiotic use against systemic bacteria in cultured aquatic animals. The essential oil of C. nardus was prepared by using the steam distillation method and the chemical composition of the essential oil was analyzed by gas chromatography-mass spectroscopy (GC-MS). Minimum inhibitory concentration (MIC) of the essential oil tested against bacterial isolates from various aquatic animals and ATCC type strains were determined using two-fold broth micro dilution method with kanamycin and eugenol as positive controls. A total of 22 chemical compounds were detected in C. nardus essential oil with 6-octenal, 3, 7-dimethyl- or citronellal representing the major compounds (29.6%). The MIC values of the citronella oil ranged from 0.244 µg/ml to 0.977 µg/ml when tested against the bacterial isolates. The results of the present study revealed the potential of C. nardus essential oil as alternative to commercial antibiotics for aquaculture use.

Deep Characterization of the Microbiomes of Calophya spp. (Hemiptera: Calophyidae) Gall-Inducing Psyllids Reveals the Absence of Plant Pathogenic Bacteria and Three Dominant Endosymbionts.

PubMed

Overholt, Will A; Diaz, Rodrigo; Rosskopf, Erin; Green, Stefan J; Overholt, William A

2015-01-01

Bacteria associated with sap-feeding insect herbivores include not only symbionts that may increase their hosts' fitness but also harmful plant pathogens. Calophya spp. gall-inducing psyllids (Hemiptera: Calophyidae) are being investigated for their potential as biological control agents of the noxious weed, Brazilian peppertree (Schinus terebinthifolia), in Florida. Although there are no examples of plant pathogen transmission by members of the family Calophyidae, several insects in the superfamily Psylloidea are known to transmit pathogenic bacteria in the genera Candidatus Liberibacter and Candidatus Phytoplasma. To determine whether Calophya spp. harbor potentially harmful plant pathogenic bacteria, we sequenced small subunit (SSU) ribosomal RNA (rRNA) gene amplicons generated from individuals from four Calophya spp. populations: All microbial SSU gene sequences fell into the bacterial domain, with 98-99% belonging to the Proteobacteria. The Calophya microbiomes contained a relatively simple community, with 49-79 operational taxonomic units (OTUs; 97%) detected, and only 5-8 OTUs with greater than 1% abundance. Candidatus Carsonella showed the highest relative abundance, with OTUs from this candidate genus representing between 51-65% of all recovered sequences. The next most abundant clade observed was an unclassified Enterobacteriacae group closely related to bacteria from the genera Buchnera and Blochmannia that ranged from 20-31% in relative abundance. Wolbachia populations were the third most abundant group and represented 7-27% of the diversity in microbial OTUs. No SSU rRNA gene sequences from putative pathogenic bacteria from the genera Ca. Liberibacter or Ca. Phytoplasma were detected in the microbiomes of the four Calophya populations. The probability that infected psyllids were present in our colonies, but were not sampled, was extremley low (1.39 x 10(-10)). As far as we are aware, our study is the first to characterize the microbiome of a candidate

Deep Characterization of the Microbiomes of Calophya spp. (Hemiptera: Calophyidae) Gall-Inducing Psyllids Reveals the Absence of Plant Pathogenic Bacteria and Three Dominant Endosymbionts

PubMed Central

2015-01-01

Bacteria associated with sap-feeding insect herbivores include not only symbionts that may increase their hosts’ fitness but also harmful plant pathogens. Calophya spp. gall-inducing psyllids (Hemiptera: Calophyidae) are being investigated for their potential as biological control agents of the noxious weed, Brazilian peppertree (Schinus terebinthifolia), in Florida. Although there are no examples of plant pathogen transmission by members of the family Calophyidae, several insects in the superfamily Psylloidea are known to transmit pathogenic bacteria in the genera Candidatus Liberibacter and Candidatus Phytoplasma. To determine whether Calophya spp. harbor potentially harmful plant pathogenic bacteria, we sequenced small subunit (SSU) ribosomal RNA (rRNA) gene amplicons generated from individuals from four Calophya spp. populations. All microbial SSU gene sequences fell into the bacterial domain, with 98-99% belonging to the Proteobacteria. The Calophya microbiomes contained a relatively simple community, with 49-79 operational taxonomic units (OTUs; 97%) detected, and only 5-8 OTUs with greater than 1% abundance. Candidatus Carsonella showed the highest relative abundance, with OTUs from this candidate genus representing between 51 – 65% of all recovered sequences. The next most abundant clade observed was an unclassified Enterobacteriacae group closely related to bacteria from the genera Buchnera and Blochmannia that ranged from 20-31% in relative abundance. Wolbachia populations were the third most abundant group and represented 7-27% of the diversity in microbial OTUs. No SSU rRNA gene sequences from putative pathogenic bacteria from the genera Ca. Liberibacter or Ca. Phytoplasma were detected in the microbiomes of the four Calophya populations. The probability that infected psyllids were present in our colonies, but were not sampled, was extremley low (1.39 x 10-10). As far as we are aware, our study is the first to characterize the microbiome of a

Twenty-one genome sequences from Pseudomonas species and 19 genome sequences from diverse bacteria isolated from the rhizosphere and endosphere of Populus deltoides.

PubMed

Brown, Steven D; Utturkar, Sagar M; Klingeman, Dawn M; Johnson, Courtney M; Martin, Stanton L; Land, Miriam L; Lu, Tse-Yuan S; Schadt, Christopher W; Doktycz, Mitchel J; Pelletier, Dale A

2012-11-01

To aid in the investigation of the Populus deltoides microbiome, we generated draft genome sequences for 21 Pseudomonas strains and 19 other diverse bacteria isolated from Populus deltoides roots. Genome sequences for isolates similar to Acidovorax, Bradyrhizobium, Brevibacillus, Caulobacter, Chryseobacterium, Flavobacterium, Herbaspirillum, Novosphingobium, Pantoea, Phyllobacterium, Polaromonas, Rhizobium, Sphingobium, and Variovorax were generated.

Confirmation and Identification of Salmonella spp., Cronobacter spp., and Other Gram-Negative Organisms by the Bruker MALDI Biotyper Method: Collaborative Study, First Action 2017.09.

PubMed

Bastin, Benjamin; Bird, Patrick; Benzinger, M Joseph; Crowley, Erin; Agin, James; Goins, David; Sohier, Daniele; Timke, Markus; Shi, Gongyi; Kostrzewa, Markus

2018-04-27

The Bruker MALDI Biotyper ® method utilizes matrix-assisted laser desorption/ionizationtime-of-flight (MALDI-TOF) MS for the rapid and accurate identification and confirmation of Gram-negative bacteria from select media types. The alternative method was evaluated using nonselective and selective agars to identify Cronobacter spp., Salmonella spp., and select Gram-negative bacteria. Results obtained by the Bruker MALDI Biotyper were compared to the traditional biochemical methods as prescribed in the appropriate reference methods. Two collaborative studies were organized, one in the United States focusing on Cronobacter spp. and other Gram-negative bacteria, and one in Europe focusing on Salmonella spp. and other Gram-negative bacteria. Fourteen collaborators from seven laboratories located within the United States participated in the first collaborative study for Cronobacter spp. Fifteen collaborators from 15 service laboratories located within Europe participated in the second collaborative study for Salmonella spp. For each target organism (either Salmonella spp. or Cronobacter spp.), a total of 24 blind-coded isolates were evaluated. In each set of 24 organisms, there were 16 inclusivity organisms ( Cronobacter spp. or Salmonella spp.) and 8 exclusivity organisms (closely related non- Cronobacter spp. and non- Salmonella spp. Gram-negative organisms). After testing was completed, the total percentage of correct identifications from each agar type for each strain was determined at a percentage of 100.0% to the genus level for the Cronobacter study and a percentage of 100.0% to the genus level for the Salmonella study. For both non- Cronobacter and non- Salmonella organisms, a percentage of 100.0% was correctly identified. The results indicated that the alternative method produced equivalent results when compared to the confirmatory procedures specified by each reference method.

Multipurpose assessment for the quantification of Vibrio spp. and total bacteria in fish and seawater using multiplex real-time polymerase chain reaction.

PubMed

Kim, Ji Yeun; Lee, Jung-Lim

2014-10-01

This study describes the first multiplex real-time polymerase chain reaction assay developed, as a multipurpose assessment, for the simultaneous quantification of total bacteria and three Vibrio spp. (V. parahaemolyticus, V. vulnificus and V. anguillarum) in fish and seawater. The consumption of raw finfish as sushi or sashimi has been increasing the chance of Vibrio outbreaks in consumers. Freshness and quality of fishery products also depend on the total bacterial populations present. The detection sensitivity of the specific targets for the multiplex assay was 1 CFU mL⁻¹ in pure culture and seawater, and 10 CFU g⁻¹ in fish. While total bacterial counts by the multiplex assay were similar to those obtained by cultural methods, the levels of Vibrio detected by the multiplex assay were generally higher than by cultural methods of the same populations. Among the natural samples without Vibrio spp. inoculation, eight out of 10 seawater and three out of 20 fish samples were determined to contain Vibrio spp. Our data demonstrate that this multiplex assay could be useful for the rapid detection and quantification of Vibrio spp. and total bacteria as a multipurpose tool for surveillance of fish and water quality as well as diagnostic method. © 2014 The Authors. Journal of the Science of Food and Agriculture published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.

Multipurpose assessment for the quantification of Vibrio spp. and total bacteria in fish and seawater using multiplex real-time polymerase chain reaction

PubMed Central

Kim, Ji Yeun; Lee, Jung-Lim

2014-01-01

Background This study describes the first multiplex real-time polymerase chain reaction assay developed, as a multipurpose assessment, for the simultaneous quantification of total bacteria and three Vibrio spp. (V. parahaemolyticus, V. vulnificus and V. anguillarum) in fish and seawater. The consumption of raw finfish as sushi or sashimi has been increasing the chance of Vibrio outbreaks in consumers. Freshness and quality of fishery products also depend on the total bacterial populations present. Results The detection sensitivity of the specific targets for the multiplex assay was 1 CFU mL−1 in pure culture and seawater, and 10 CFU g−1 in fish. While total bacterial counts by the multiplex assay were similar to those obtained by cultural methods, the levels of Vibrio detected by the multiplex assay were generally higher than by cultural methods of the same populations. Among the natural samples without Vibrio spp. inoculation, eight out of 10 seawater and three out of 20 fish samples were determined to contain Vibrio spp. Conclusion Our data demonstrate that this multiplex assay could be useful for the rapid detection and quantification of Vibrio spp. and total bacteria as a multipurpose tool for surveillance of fish and water quality as well as diagnostic method. © 2014 The Authors. Journal of the Science of Food and Agriculture published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:24752974

Occurrence of squalene in methanol-grown bacteria.

PubMed Central

Goldberg, I; Shechter, I

1978-01-01

The nonpolar lipids of methanol-grown bacteria which utilize one-carbon (C1) compounds via the RMP pathway (Pseudomonas C, Pseudomonas methylotropha, and Methylomonas methanolica) were found to contain squalene in concentrations between 0.1 to 1.16 mg/g of cell (dry weight). Squalene could not be detected in lipid extracts of methanol-grown bacteria which utilize C1 compounds via the serine pathway. PMID:98521

Twenty-One Genome Sequences from Pseudomonas Species and 19 Genome Sequences from Diverse Bacteria Isolated from the Rhizosphere and Endosphere of Populus deltoides

PubMed Central

Utturkar, Sagar M.; Klingeman, Dawn M.; Johnson, Courtney M.; Martin, Stanton L.; Land, Miriam L.; Lu, Tse-Yuan S.; Schadt, Christopher W.; Doktycz, Mitchel J.

2012-01-01

To aid in the investigation of the Populus deltoides microbiome, we generated draft genome sequences for 21 Pseudomonas strains and 19 other diverse bacteria isolated from Populus deltoides roots. Genome sequences for isolates similar to Acidovorax, Bradyrhizobium, Brevibacillus, Caulobacter, Chryseobacterium, Flavobacterium, Herbaspirillum, Novosphingobium, Pantoea, Phyllobacterium, Polaromonas, Rhizobium, Sphingobium, and Variovorax were generated. PMID:23045501

Twenty-One Genome Sequences from Pseudomonas Species and 19 Genome Sequences from Diverse Bacteria Isolated from the Rhizosphere and Endosphere of Populus deltoides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Steven D; Utturkar, Sagar M; Klingeman, Dawn Marie

To aid in the investigation of the Populus deltoides microbiome we generated draft genome sequences for twenty one Pseudomonas and twenty one other diverse bacteria isolated from Populus deltoides roots. Genome sequences for isolates similar to Acidovorax, Bradyrhizobium, Brevibacillus, Burkholderia, Caulobacter, Chryseobacterium, Flavobacterium, Herbaspirillum, Novosphingobium, Pantoea, Phyllobacterium, Polaromonas, Rhizobium, Sphingobium and Variovorax were generated.

Pyogranulomatous pleuropneumonia and mediastinitis in ferrets (Mustela putorius furo) associated with Pseudomonas luteola Infection.

PubMed

Martínez, J; Martorell, J; Abarca, M L; Olvera, A; Ramis, A; Woods, L; Cheville, N; Juan-Sallés, C; Moya, A; Riera, A; Soto, S

2012-01-01

Between 2008 and 2009, three pet ferrets from different sources presented with acute episode of dyspnoea. Cytological examination of pleural exudates revealed severe purulent inflammation with abundant clusters of rod-shaped microorganisms with a clear surrounding halo. Treatment was ineffective and the ferrets died 2-5 days later. Two ferrets were subjected to necropsy examination, which revealed pyothorax, mediastinal lymphadenopathy and multiple white nodules (1-2mm) in the lungs. Microscopical examination showed multifocal necrotizing-pyogranulomatous pleuropneumonia and lymphadenitis with aggregates of encapsulated microorganisms, some of which were positively stained by periodic acid-Schiff and alcian blue. In-situ hybridization for Pneumocystis spp., Ziehl-Neelsen staining and immunohistochemistry for distemper, coronavirus and influenza antigen were negative in all cases. Electron microscopically, the bacteria were 2-3 μm long with a thick electron-lucent capsule. Microbiology from one ferret yielded a pure culture of gram-negative bacteria identified phenotypically as Pseudomonas luteola. This speciation was later confirmed by 16S RNA gene amplification. Copyright © 2011. Published by Elsevier Ltd.

Isolation and Molecular Detection of Gram Negative Bacteria Causing Urinary Tract Infection in Patients Referred to Shahrekord Hospitals, Iran.

PubMed

Tajbakhsh, Elahe; Tajbakhsh, Sara; Khamesipour, Faham

2015-05-01

Urinary Tract Infections (UTI), and their complications, cause serious health problems, which affect millions of people every year. Infections of the urinary tract are the second most common type of infection in the body and approximately 20% of women are especially prone to UTIs for reasons not yet well understood. Urinary Tract Infections in men are not as common as in women yet can be very serious when they do occur. Accurate identification of bacterial isolates is an essential task of the clinical microbiology laboratory. The purpose of this study was to determine the incidence and variety of the causative microbial agents of UTIs in patients who had referred to a medical laboratory of Kashani and Hajar hospital in Shahrekord, Iran. In this cross-sectional study 147 urine samples of patients (urine test results were positive for UTIs) were examined during April to September 2013. A total of 147 urine samples of patients with clinical symptoms of UTI who had been referred to a medical laboratory of Kashani and Hajar hospital in Shahrekord (Iran), were collected and processed immediately for laboratory analysis. Escherichia coli was identified as the most common causative agent of UTIs (51.70% of total isolates in both sexes), followed by Klebsiella pneumoniae (K. Pneumoniae) (16.32%). Frequency of Proteus spp., Acinetobacter spp., Entrobacter spp., Citrobacter spp., Pseudomonas aeruginosa (P. aeruginosa) and Providencia spp. was 10.88%, 6.12%, 5.44%, 4.08%, 3.40% and 2.04%, respectively. Statistical analysis by Fisher exact test showed that there was no significant relationship between the type of bacteria and gender (P > 0.05). Chi square test showed that there was no significant relationship between the type of bacteria and the use of catheter and age group (P > 0.05). However, there was a significant relationship between the type of bacteria and the history of hospitalization (P > 0.05). Our findings implied that a wide range of bacteria could be involved in

High Prevalence of Ceftazidime-Resistant Klebsiella pneumoniae and Increase of Imipenem-Resistant Pseudomonas aeruginosa and Acinetobacter spp. in Korea: a KONSAR Program in 2004

PubMed Central

Lee, Kyungwon; Lim, Chang Hyun; Cho, Ji Hyun; Lee, Wee Gyo; Uh, Young; Kim, Hwi Jun; Yong, Dongeun

2006-01-01

A nationwide antimicrobial resistance surveillance has been conducted since 1997 in Korea. In this study, susceptibility test data generated in 2004 by KONSAR group hospitals were analyzed and compared to those at a commercial laboratory. In hospitals, the rank orders of organisms in 2004 were identical to those in 2003. The most prevalent species was Staphylococcus aureus (20.2%) in hospitals, but Escherichia coli (29.7%) in the commercial laboratory. The proportions of Enterococcus faecium to all isolates of Enterococcus faecalis plus E. faecium were 47.2% in hospitals and 24.9% in the commercial laboratory. The mean resistance rates of significant antimicrobial-organism combinations in hospitals were: oxacillin-resistant S. aureus (68%), oxacillin-resistant (penicillin-nonsusceptible) Streptococcus pneumoniae (68%), vancomycin-resistant E. faecium (25%), cefotaxime-resistant E. coli (14%), ceftazidime- and cefoxitin-resistant Klebsiella pneumoniae (34% and 32%, respectively), and imipenem-resistant Acinetobacter spp. and Pseudomonas aeruginosa (17% and 24%, respectively). In conclusion, oxacillin-resistant staphylococci, expanded-spectrum cephalosporin-resistant K. pneumoniae, and imipenem-resistant Acinetobacter spp. and P. aeruginosa were prevalent in 2004. Increasing trends were observed for vancomycin-resistant E. faecium, cefoxitin-resistant E. coli and K. pneumoniae, and imipenem-resistant Acinetobacter spp. and P. aeruginosa. Certain antimicrobial-organism combinations were also prevalent among the commercial laboratory-tested strains. PMID:17066507

Rock weathering by indigenous heterotrophic bacteria of Bacillus spp. at different temperature: a laboratory experiment

NASA Astrophysics Data System (ADS)

Štyriaková, I.; Štyriak, I.; Oberhänsli, H.

2012-07-01

The bio-weathering of basalt, granite and gneiss was experimentally investigated in this study. These rock-forming minerals weathered more rapidly via the ubiquitous psychrotrophic heterotrophic bacteria . With indigenous bacteria of Bacillus spp. from sediments of Lake Baikal, we traced the degradation process of silicate minerals to understand the weathering processes occurring at the change temperature in the subsurface environment with organic input. The bacteria mediated dissolution of minerals was monitored with solution and solid chemistry, X-ray analyses as well as microscopic techniques. We determined the impact of the bacteria on the mineral surface and leaching of K, Ca, Mg, Si, Fe, and Al from silicate minerals. In the samples the release of major structural elements of silicates was used as an overall indicator of silicate mineral degradation at 4°C and 18°C from five medium exchanges over 255 days of rock bioleaching. The increase of temperature importantly affected the efficiency of Fe extraction from granite and basalt as well as Si extraction from granite and gneiss. In comparison with elemental extraction order at 4°C, Ca was substituted first by Fe or Si. It is evident that temperature influences rock microbial weathering and results in a change of elements extraction.

Numerical taxonomy of heavy metal tolerant bacteria isolated from the estuarine environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, D.A.; Austin, B.; Mills, A.L.

1977-01-01

Metal tolerant bacteria, totalling 301 strains, were isolated from water and sediment samples collected from Chesapeake Bay. Growth in the presence of 100 ppm cadmium, chromium, cobalt, lead, mercury and molybdenum was tested. In addition, the strains were examined for 118 biochemical, cultural, morphological, nutritional and physiological, characters and the data were analyzed by computer, using the simple matching and Jaccard coefficients. From sorted similarity matrices, 293 strains, 97% of the total, were removed in 12 clusters defined at the 80 to 85% similarity level. The clusters included Bacillus and Pseudomonas spp. and genera and species of Enterobacteriaceae. Three clusters,more » containing gram negative rods, were not identified. Several of the clusters were composed of strains exhibiting tolerance to a wide range of heavy metals, whereas three of the clusters contained bacteria that were capable of growth in the presence of only a few of the metals examined in this study. Antibiotic resistance of the metal resistant strains has also been examined.« less

Plasmid-Mediated High-Level Gentamicin Resistance among Enteric Bacteria Isolated from Pet Turtles in Louisiana

PubMed Central

Díaz, María Alejandra; Cooper, Richard Kent; Cloeckaert, Axel; Siebeling, Ronald John

2006-01-01

The sale of small turtles is banned by the Food and Drug Administration from the U.S. market due to concerns about their excretion of Salmonella spp. To produce a safe pet for the export market, the Louisiana pet turtle industry uses gentamicin sulfate baths (1,000 μg/ml) to eradicate Salmonella spp. from turtle eggs. In 1999, we analyzed bacterial samples recovered from turtle farms and found that strains of Salmonella enterica subsp. arizonae and other bacteria, such as Enterobacter cloacae, Citrobacter freundii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia, were resistant to high concentrations of gentamicin (>2,000 μg/ml) and to other aminoglycosides. The goal of this study was to identify the gene(s) which contributes to the high-level gentamicin resistance phenotype observed in bacteria from environmental samples with turtle farming activity, particularly the salmonellae, and to estimate the incidence of such genes in these bacteria. R plasmids from gentamicin-resistant strains were transferred by conjugation and transformation to naive Escherichia coli cells. Cloning and sequencing of the gentamicin resistance determinants on these plasmids revealed the presence of the aminoglycoside acetyltransferase genes aac(3)-IIa and aac(3)-VIa; the latter was present as a gene cassette of a class 1 integron. Multiplex PCR assays showed that every gentamicin-resistant isolate carried one of these acetyltransferase genes. Pulsed-field gel electrophoresis and restriction enzyme digestion analysis of R plasmids carrying these genes revealed different restriction profiles and sizes, indicating a dissemination of the gentamicin resistance genes through mobile molecular elements. The data presented highlight the need to develop an alternate method for the eradication of Salmonella spp. from turtle eggs. PMID:16391058

Plasmid-mediated high-level gentamicin resistance among enteric bacteria isolated from pet turtles in Louisiana.

PubMed

Díaz, María Alejandra; Cooper, Richard Kent; Cloeckaert, Axel; Siebeling, Ronald John

2006-01-01

The sale of small turtles is banned by the Food and Drug Administration from the U.S. market due to concerns about their excretion of Salmonella spp. To produce a safe pet for the export market, the Louisiana pet turtle industry uses gentamicin sulfate baths (1,000 microg/ml) to eradicate Salmonella spp. from turtle eggs. In 1999, we analyzed bacterial samples recovered from turtle farms and found that strains of Salmonella enterica subsp. arizonae and other bacteria, such as Enterobacter cloacae, Citrobacter freundii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia, were resistant to high concentrations of gentamicin (>2,000 microg/ml) and to other aminoglycosides. The goal of this study was to identify the gene(s) which contributes to the high-level gentamicin resistance phenotype observed in bacteria from environmental samples with turtle farming activity, particularly the salmonellae, and to estimate the incidence of such genes in these bacteria. R plasmids from gentamicin-resistant strains were transferred by conjugation and transformation to naive Escherichia coli cells. Cloning and sequencing of the gentamicin resistance determinants on these plasmids revealed the presence of the aminoglycoside acetyltransferase genes aac(3)-IIa and aac(3)-VIa; the latter was present as a gene cassette of a class 1 integron. Multiplex PCR assays showed that every gentamicin-resistant isolate carried one of these acetyltransferase genes. Pulsed-field gel electrophoresis and restriction enzyme digestion analysis of R plasmids carrying these genes revealed different restriction profiles and sizes, indicating a dissemination of the gentamicin resistance genes through mobile molecular elements. The data presented highlight the need to develop an alternate method for the eradication of Salmonella spp. from turtle eggs.

Five-Year Antimicrobial Susceptibility Trends Among Bacterial Isolates from a Tertiary Health-Care Facility in Kigali, Rwanda.

PubMed

Carroll, Makeda; Rangaiahagari, Ashok; Musabeyezu, Emmanuel; Singer, Donald; Ogbuagu, Onyema

2016-12-07

Antimicrobial resistance (AMR) is a global public health threat. There is limited information from Rwanda on AMR trends. This longitudinal study aimed to describe temporal trends of antibiotic susceptibility among common bacteria. We collated the antimicrobial susceptibility results of bacteria cultured from clinical specimens collected from inpatients and outpatients and submitted to the microbiology laboratory at King Faisal Hospital, Kigali, Rwanda, from January 1, 2009, to December 31, 2013. Differences in antimicrobial susceptibility between the first and fifth year of the study for each bacterial species was assessed using χ 2 test. Of 5,296 isolates collected, 46.7% were Escherichia coli, 18.4% were Klebsiella spp., 5.9% were Acinetobacter spp., 7.1% were Pseudomonas spp., 11.7% were Staphylococcus aureus, and 10.3% were Enterococcus spp. Colistin and imipenem had greatest activity against gram-negative bacteria. Acinetobacter spp. showed the greatest resistance profile to antimicrobials tested, relative to other gram-negative bacteria. Vancomycin retained excellent activity against S. aureus and Enterococcus species (average susceptibility was 100% and 99.4%, respectively). Trend analysis determined that resistance to imipenem increased significantly among Klebsiella, E. coli, Pseudomonas, and Acinetobacter isolates; there was also rising resistance to colistin among E. coli and Pseudomonas species. Only E. coli demonstrated increased resistance to gentamicin. For gram-positive pathogens, vancomycin susceptibility increased over time for Enterococcus species, but was unchanged for S. aureus Our data suggest that resistance to imipenem and colistin are rising among gram-negative bacteria in Rwanda. Proper infection control practices and antimicrobial stewardship will be important to address this emerging threat. © The American Society of Tropical Medicine and Hygiene.

Impact of reporting gram stain results from blood culture bottles on the selection of antimicrobial agents.

PubMed

Uehara, Yuki; Yagoshi, Michiko; Tanimichi, Yumiko; Yamada, Hiroko; Shimoguchi, Kazuo; Yamamoto, Sachiyo; Yanai, Mitsuru; Kumasaka, Kazunari

2009-07-01

We assessed the usefulness of reporting direct blood Gram stain results compared with the results of positive blood cultures in 482 episodes and monitored impact on selection of antimicrobial treatment. We found that the reporting groups "Staphylococcus spp," "Pseudomonas spp and related organisms," and "yeasts" identified in this way matched perfectly with later culture identification. When the report indicated Staphylococcus spp or Pseudomonas spp and related organisms, physicians started or changed antimicrobials suitable for these bacteria more frequently than when "other streptococci" and "family Enterobacteriaceae" were reported (P < .05). Incorrect recognition of Acinetobacter spp as Enterobacteriaceae family is still the most challenging problem in this context. Gram stain results that definitively identify Staphylococcus spp, Pseudomonas spp and related organisms, and yeasts reliably can be rapidly provided by clinical laboratories; this information has a significant impact on early selection of effective antimicrobials. Further investigation is needed to assess the clinical impact of reporting Gram stain results in bacteremia.

Biofilm formation and cellulose expression among diverse environmental Pseudomonas isolates.

PubMed

Ude, Susanne; Arnold, Dawn L; Moon, Christina D; Timms-Wilson, Tracey; Spiers, Andrew J

2006-11-01

The ability to form biofilms is seen as an increasingly important colonization strategy among both pathogenic and environmental bacteria. A survey of 185 plant-associated, phytopathogenic, soil and river Pseudomonas isolates resulted in 76% producing biofilms at the air-liquid (A-L) interface after selection in static microcosms. Considerable variation in biofilm phenotype was observed, including waxy aggregations, viscous and floccular masses, and physically cohesive biofilms with continuously varying strengths over 1500-fold. Calcofluor epifluorescent microscopy identified cellulose as the matrix component in biofilms produced by Pseudomonas asplenii, Pseudomonas corrugata, Pseudomonas fluorescens, Pseudomonas marginalis, Pseudomonas putida, Pseudomonas savastanoi and Pseudomonas syringae isolates. Cellulose expression and biofilm formation could be induced by the constitutively active WspR19 mutant of the cyclic-di-GMP-associated, GGDEF domain-containing response regulator involved in the P. fluorescens SBW25 wrinkly spreader phenotype and cellular aggregation in Pseudomonas aeruginosa PA01. WspR19 could also induce P. putida KT2440, which otherwise did not produce a biofilm or express cellulose, as well as Escherichia coli K12 and Salmonella typhimurium LT2, both of which express cellulose yet lack WspR homologues. Statistical analysis of biofilm parameters suggest that biofilm development is a more complex process than that simply described by the production of attachment and matrix components and bacterial growth. This complexity was also seen in multivariate analysis as a species-ecological habitat effect, underscoring the fact that in vitro biofilms are abstractions of those surface and volume colonization processes used by bacteria in their natural environments.

Chemical composition and antimicrobial activity of Cymbopogon nardus citronella essential oil against systemic bacteria of aquatic animals

PubMed Central

Wei, Lee Seong; Wee, Wendy

2013-01-01

Background & Objectives This paper describes chemical composition and antimicrobial activity of Cymbopogon nardus citronella essential oil against Edwardsiella spp. (n = 21), Vibrio spp. (n = 6), Aeromonas spp. (n = 2), Escherichia coli (n = 2), Salmonella spp. (n = 2), Flavobacterium spp. (n = 1), Pseudomonas spp. (n = 1) and Streptococcus spp. (n = 1) isolated from internal organs of aquatic animals. Due to the ban of antibiotics for aquaculture use, this study was carried out to evaluate the potential of citronella essential oil as alternative to commercial antibiotic use against systemic bacteria in cultured aquatic animals. Materials & Methods The essential oil of C. nardus was prepared by using the steam distillation method and the chemical composition of the essential oil was analyzed by gas chromatography–mass spectroscopy (GC–MS). Minimum inhibitory concentration (MIC) of the essential oil tested against bacterial isolates from various aquatic animals and ATCC type strains were determined using two-fold broth micro dilution method with kanamycin and eugenol as positive controls. Results A total of 22 chemical compounds were detected in C. nardus essential oil with 6-octenal, 3, 7-dimethyl- or citronellal representing the major compounds (29.6%). The MIC values of the citronella oil ranged from 0.244 µg/ml to 0.977 µg/ml when tested against the bacterial isolates. Conclusion The results of the present study revealed the potential of C. nardus essential oil as alternative to commercial antibiotics for aquaculture use. PMID:23825733

Clinicomicrobiological profile of endophthalmitis: A 10 year experience in a Tertiary Care Center in North India.

PubMed

Satpathy, Gita; Nayak, Niranjan; Wadhwani, Meenakshi; Venkwatesh, Pradeep; Kumar, Atul; Sharma, Yograj; Sreenivas, Vishnu

2017-01-01

To determine the clinicomicrobiological profile of infectious agents and their antibiotic susceptibility in different type of endophthalmitis. A retrospective review of clinical and microbiological records from January 2001 to December 2010, was performed in 1110 patients diagnosed with different type of endophthalmitis (postoperative, posttraumatic, endogenous and post keratitis) to record the demographic details, clinical presentations; microbiological agents isolated with their antimicrobial sensitivity pattern. Antimicrobial susceptibility testing for various culture positive isolates (bacterial/fungal) was performed by the disc diffusion technique. Out of the 1110 intra-ocular specimens processed, 384 (34.6%) were positive for bacteria. S epidermidis was the most predominant isolate accounting for 42.7% of all bacteria obtained, followed by Pseudomonas aeruginosa (24.5%). Besides Pseudomonas, Acinetobacter spp. were the next common gram negative bacilli detected (8.3%) followed by Klebsiella, E. coli, Enterobacter and Alkaligenes in 2.6%, 0.8%, 0.8% and 0.5% cases respectively. The predominant fungal species were Aspergillus spp., in 36.1%, followed by Fusarium spp. in 26.4% cases. Overall susceptibility pattern in our study showed that gram positive bacteria were most susceptible to glycopeptides like vancomycin (80-100%) and fluoroquinolones (87-91%). The sensitivity pattern of gram negative organisms like Pseudomonas and Klebsiella towards fluoroquinolones ranged between 61% - 82%. S epidermidis was the most common bacteria isolated in postoperative and posttraumatic endophthalmitis, Pseudomonas aeruginosa was the most common bacterial isolated in posttraumatic endophthalmitisAmongst fungi Aspergillus was the most common organism.

Molecular and chemical dialogues in bacteria-protozoa interactions.

PubMed

Song, Chunxu; Mazzola, Mark; Cheng, Xu; Oetjen, Janina; Alexandrov, Theodore; Dorrestein, Pieter; Watrous, Jeramie; van der Voort, Menno; Raaijmakers, Jos M

2015-08-06

Protozoan predation of bacteria can significantly affect soil microbial community composition and ecosystem functioning. Bacteria possess diverse defense strategies to resist or evade protozoan predation. For soil-dwelling Pseudomonas species, several secondary metabolites were proposed to provide protection against different protozoan genera. By combining whole-genome transcriptome analyses with (live) imaging mass spectrometry (IMS), we observed multiple changes in the molecular and chemical dialogues between Pseudomonas fluorescens and the protist Naegleria americana. Lipopeptide (LP) biosynthesis was induced in Pseudomonas upon protozoan grazing and LP accumulation transitioned from homogeneous distributions across bacterial colonies to site-specific accumulation at the bacteria-protist interface. Also putrescine biosynthesis was upregulated in P. fluorescens upon predation. We demonstrated that putrescine induces protozoan trophozoite encystment and adversely affects cyst viability. This multifaceted study provides new insights in common and strain-specific responses in bacteria-protozoa interactions, including responses that contribute to bacterial survival in highly competitive soil and rhizosphere environments.

Long-Chain Alkyl Cyanides: Unprecedented Volatile Compounds Released by Pseudomonas and Micromonospora Bacteria.

PubMed

Montes Vidal, Diogo; von Rymon-Lipinski, Anna-Lena; Ravella, Srinivasa; Groenhagen, Ulrike; Herrmann, Jennifer; Zaburannyi, Nestor; Zarbin, Paulo H G; Varadarajan, Adithi R; Ahrens, Christian H; Weisskopf, Laure; Müller, Rolf; Schulz, Stefan

2017-04-03

The analysis of volatiles from bacterial cultures revealed long-chain aliphatic nitriles, a new class of natural products. Such nitriles are produced by both Gram-positive Micromonospora echinospora and Gram-negative Pseudomonas veronii bacteria, although the structures differ. A variable sequence of chain elongation and dehydration in the fatty acid biosynthesis leads to either unbranched saturated or unsaturated nitriles with an ω-7 double bond, such as (Z)-11-octadecenenitrile, or methyl-branched unsaturated nitriles with the double bond located at C-3, such as (Z)-13-methyltetradec-3-enenitrile. The nitrile biosynthesis starts from fatty acids, which are converted into their amides and finally dehydrated. The structures and biosyntheses of the 19 naturally occurring compounds were elucidated by mass spectrometry, synthesis, and feeding experiments with deuterium-labeled precursors. Some of the nitriles showed antimicrobial activity, for example, against multiresistant Staphylococcus aureus strains. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Killer Pigments in Bacteria: An Ecological Nightmare.

ERIC Educational Resources Information Center

Benathen, Isaiah A.; Saccardi, Marion

2000-01-01

Describes an alternative to teaching ecology by using bacteria to test competitor survival. Students observe a time-dependent selective killing of other unrelated bacteria by Pseudomonas aeruginosa. (SAH)

Bacterial 16S rRNA gene analysis revealed that bacteria related to Arcobacter spp. constitute an abundant and common component of the oyster microbiota (Tiostrea chilensis).

PubMed

Romero, J; García-Varela, M; Laclette, J P; Espejo, R T

2002-11-01

To explore the bacterial microbiota in Chilean oyster (Tiostrea chilensis), a molecular approach that permits detection of different bacteria, independently of their capacity to grow in culture media, was used. Bacterial diversity was assessed by analysis of both the 16S rDNA and the 16S-23S intergenic region, obtained by PCR amplifications of DNA extracted from depurated oysters. RFLP of the PCR amplified 16S rDNA showed a prevailing pattern in most of the individuals analyzed, indicating that a few bacterial species were relatively abundant and common in oysters. Cloning and sequencing of the 16S rDNA with the prevailing RFLP pattern indicated that this rRNA was most closely related to Arcobacter spp. However, analysis by the size of the amplified 16S-23S rRNA intergenic regions revealed not Arcobacter spp. but Staphylococcus spp. related bacteria as a major and common component in oyster. These different results may be caused by the absence of target for one of the primers employed for amplification of the intergenic region. Neither of the two bacteria species found in large abundance was recovered after culturing under aerobic, anaerobic, or microaerophilic conditions. This result, however, is expected because the number of bacteria recovered after cultivation was less than 0.01% of the total. All together, these observations suggest that Arcobacter-related strains are probably abundant and common in the Chilean oyster bacterial microbiota.

An Interspecies Signaling System Mediated by Fusaric Acid Has Parallel Effects on Antifungal Metabolite Production by Pseudomonas protegens Strain Pf-5 and Antibiosis of Fusarium spp.

PubMed Central

Quecine, Maria Carolina; Kidarsa, Teresa A.; Goebel, Neal C.; Shaffer, Brenda T.; Henkels, Marcella D.; Zabriskie, T. Mark

2015-01-01

Pseudomonas protegens strain Pf-5 is a rhizosphere bacterium that suppresses soilborne plant diseases and produces at least seven different secondary metabolites with antifungal properties. We derived mutants of Pf-5 with single and multiple mutations in biosynthesis genes for seven antifungal metabolites: 2,4-diacetylphoroglucinol (DAPG), pyrrolnitrin, pyoluteorin, hydrogen cyanide, rhizoxin, orfamide A, and toxoflavin. These mutants were tested for inhibition of the pathogens Fusarium verticillioides and Fusarium oxysporum f. sp. pisi. Rhizoxin, pyrrolnitrin, and DAPG were found to be primarily responsible for fungal antagonism by Pf-5. Previously, other workers showed that the mycotoxin fusaric acid, which is produced by many Fusarium species, including F. verticillioides, inhibited the production of DAPG by Pseudomonas spp. In this study, amendment of culture media with fusaric acid decreased DAPG production, increased pyoluteorin production, and had no consistent influence on pyrrolnitrin or orfamide A production by Pf-5. Fusaric acid also altered the transcription of biosynthetic genes, indicating that the mycotoxin influenced antibiotic production by Pf-5 at the transcriptional level. Addition of fusaric acid to the culture medium reduced antibiosis of F. verticillioides by Pf-5 and derivative strains that produce DAPG but had no effect on antibiosis by Pf-5 derivatives that suppressed F. verticillioides due to pyrrolnitrin or rhizoxin production. Our results demonstrated the importance of three compounds, rhizoxin, pyrrolnitrin, and DAPG, in suppression of Fusarium spp. by Pf-5 and confirmed that an interspecies signaling system mediated by fusaric acid had parallel effects on antifungal metabolite production and antibiosis by the bacterial biological control organism. PMID:26655755

phzO, a Gene for Biosynthesis of 2-Hydroxylated Phenazine Compounds in Pseudomonas aureofaciens 30-84

PubMed Central

Delaney, Shannon M.; Mavrodi, Dmitri V.; Bonsall, Robert F.; Thomashow, Linda S.

2001-01-01

Certain strains of root-colonizing fluorescent Pseudomonas spp. produce phenazines, a class of antifungal metabolites that can provide protection against various soilborne root pathogens. Despite the fact that the phenazine biosynthetic locus is highly conserved among fluorescent Pseudomonas spp., individual strains differ in the range of phenazine compounds they produce. This study focuses on the ability of Pseudomonas aureofaciens 30-84 to produce 2-hydroxyphenazine-1-carboxylic acid (2-OH-PCA) and 2-hydroxyphenazine from the common phenazine metabolite phenazine-1-carboxylic acid (PCA). P. aureofaciens 30-84 contains a novel gene located downstream from the core phenazine operon that encodes a 55-kDa aromatic monooxygenase responsible for the hydroxylation of PCA to produce 2-OH-PCA. Knowledge of the genes responsible for phenazine product specificity could ultimately reveal ways to manipulate organisms to produce multiple phenazines or novel phenazines not previously described. PMID:11114932

[Risk factors for Pseudomonas aeruginosa infections, resistant to carbapenem].

PubMed

Ghibu, Laura; Miftode, Egidia; Teodor, Andra; Bejan, Codrina; Dorobăţ, Carmen Mihaela

2010-01-01

Since their introduction in clinical practice,carbapenems have been among the most powerful antibiotics for treating serious infections cased by Gram-negative nosocomial pathogens, including Pseudomonas aeruginosa. The emergence of betalactamases with carbapenem-hydrolyzing activity is of major clinical concern. Pseudomonas aeruginosa is a leading cause of nosocomial infection. Risk factors for colonization with carbapenems-resistant Pseudomonas in hospital are: history of P. aeruginosa infection or colonization within the previous year, (length of hospital stay, being bedridden or in the ICU, mechanical ventilation, malignant disease, and history of chronic obstructive pulmonary disease have all been identified as independent risk factors for MDR P. aeruginosa infection. Long-term-care facilities are also reservoirs of resistant bacteria. Risk factors for colonization of LTCF residents with resistant bacteria included age > 86 years, antibiotic treatment in the previous 3 months, indwelling devices, chronic obstructive pulmonary disease, physical disability, and the particular LTCF unit.

Enrichment and characterization of hydrocarbon-degrading bacteria from petroleum refinery waste as potent bioaugmentation agent for in situ bioremediation.

PubMed

Sarkar, Poulomi; Roy, Ajoy; Pal, Siddhartha; Mohapatra, Balaram; Kazy, Sufia K; Maiti, Mrinal K; Sar, Pinaki

2017-10-01

Intrinsic biodegradation potential of bacteria from petroleum refinery waste was investigated through isolation of cultivable strains and their characterization. Pseudomonas and Bacillus spp. populated the normal cultivable taxa while prolonged enrichment with hydrocarbons and crude oil yielded hydrocarbonoclastic bacteria of genera Burkholderia, Enterobacter, Kocuria, Pandoraea, etc. Strains isolated through enrichment showed assemblages of superior metabolic properties: utilization of aliphatic (C6-C22) and polyaromatic compounds, anaerobic growth with multiple terminal electron acceptors and higher biosurfactant production. Biodegradation of dodecane was studied thoroughly by GC-MS along with detection of gene encoding alkane hydroxylase (alkB). Microcosms bioaugmented with Enterobacter, Pandoraea and Burkholderia strains showed efficient biodegradation (98% TPH removal) well fitted in first order kinetic model with low rate constants and decreased half-life. This study proves that catabolically efficient bacteria resides naturally in complex petroleum refinery wastes and those can be useful for bioaugmentation based bioremediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative genomics of Fructobacillus spp. and Leuconostoc spp. reveals niche-specific evolution of Fructobacillus spp.

DOE PAGES

Endo, Akihito; Tanizawa, Yasuhiro; Tanaka, Naoto; ...

2015-12-29

In this study, Fructobacillus spp. in fructose-rich niches belong to the family Leuconostocaceae. They were originally classified as Leuconostoc spp., but were later grouped into a novel genus, Fructobacillus , based on their phylogenetic position, morphology and specific biochemical characteristics. The unique characters, so called fructophilic characteristics, had not been reported in the group of lactic acid bacteria, suggesting unique evolution at the genome level. Here we studied four draft genome sequences of Fructobacillus spp. and compared their metabolic properties against those of Leuconostoc spp. As a result, Fructobacillus species possess significantly less protein coding sequences in their small genomes.more » The number of genes was significantly smaller in carbohydrate transport and metabolism. Several other metabolic pathways, including TCA cycle, ubiquinone and other terpenoid-quinone biosynthesis and phosphotransferase systems, were characterized as discriminative pathways between the two genera. The adhE gene for bifunctional acetaldehyde/alcohol dehydrogenase, and genes for subunits of the pyruvate dehydrogenase complex were absent in Fructobacillus spp. The two genera also show different levels of GC contents, which are mainly due to the different GC contents at the third codon position. In conclusion, the present genome characteristics in Fructobacillus spp. suggest reductive evolution that took place to adapt to specific niches.« less

Comparative genomics of Fructobacillus spp. and Leuconostoc spp. reveals niche-specific evolution of Fructobacillus spp.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Endo, Akihito; Tanizawa, Yasuhiro; Tanaka, Naoto

In this study, Fructobacillus spp. in fructose-rich niches belong to the family Leuconostocaceae. They were originally classified as Leuconostoc spp., but were later grouped into a novel genus, Fructobacillus , based on their phylogenetic position, morphology and specific biochemical characteristics. The unique characters, so called fructophilic characteristics, had not been reported in the group of lactic acid bacteria, suggesting unique evolution at the genome level. Here we studied four draft genome sequences of Fructobacillus spp. and compared their metabolic properties against those of Leuconostoc spp. As a result, Fructobacillus species possess significantly less protein coding sequences in their small genomes.more » The number of genes was significantly smaller in carbohydrate transport and metabolism. Several other metabolic pathways, including TCA cycle, ubiquinone and other terpenoid-quinone biosynthesis and phosphotransferase systems, were characterized as discriminative pathways between the two genera. The adhE gene for bifunctional acetaldehyde/alcohol dehydrogenase, and genes for subunits of the pyruvate dehydrogenase complex were absent in Fructobacillus spp. The two genera also show different levels of GC contents, which are mainly due to the different GC contents at the third codon position. In conclusion, the present genome characteristics in Fructobacillus spp. suggest reductive evolution that took place to adapt to specific niches.« less

Potential application of Northern Argentine propolis to control some phytopathogenic bacteria.

PubMed

Ordóñez, R M; Zampini, I C; Moreno, M I Nieva; Isla, M I

2011-10-20

The antimicrobial activity of samples of Northern Argentine propolis (Tucumán, Santiago del Estero and Chaco) against phytopathogenic bacteria was assessed and the most active samples were identified. Minimal inhibitory concentration (MIC) values were determined by agar macrodilution and broth microdilution assays. Strong antibacterial activity was detected against Erwinia carotovora spp carotovora CECT 225, Pseudomonas syringae pvar tomato CECT 126, Pseudomonas corrugata CECT 124 and Xanthomonas campestris pvar vesicatoria CECT 792. The most active propolis extract (Tucumán, T1) was selected to bioguide isolation and identified for antimicrobial compound (2',4'-dihydroxychalcone). The antibacterial chalcone was more active than the propolis ethanolic extract (MIC values of 0.5-1 μg ml(-1) and 9.5-15 μg ml(-1), respectively). Phytotoxicity assays were realized and the propolis extracts did not retard germination of lettuce seeds or the growth of onion roots. Propolis solutions applied as sprays on tomato fruits infected with P. syringae reduced the severity of disease. Application of the Argentine propolis extracts diluted with water may be promising for the management of post harvest diseases of fruits. Copyright © 2010 Elsevier GmbH. All rights reserved.

Genetic Diversity of Nitrogen-Fixing and Plant Growth Promoting Pseudomonas Species Isolated from Sugarcane Rhizosphere

PubMed Central

Li, Hai-Bi; Singh, Rajesh K.; Singh, Pratiksha; Song, Qi-Qi; Xing, Yong-Xiu; Yang, Li-Tao; Li, Yang-Rui

2017-01-01

The study was designed to isolate and characterize Pseudomonas spp. from sugarcane rhizosphere, and to evaluate their plant- growth- promoting (PGP) traits and nitrogenase activity. A biological nitrogen-fixing microbe has great potential to replace chemical fertilizers and be used as a targeted biofertilizer in a plant. A total of 100 isolates from sugarcane rhizosphere, belonging to different species, were isolated; from these, 30 isolates were selected on the basis of preliminary screening, for in vitro antagonistic activities against sugarcane pathogens and for various PGP traits, as well as nitrogenase activity. The production of IAA varied from 312.07 to 13.12 μg mL−1 in tryptophan supplemented medium, with higher production in AN15 and lower in CN20 strain. The estimation of ACC deaminase activity, strains CY4 and BA2 produced maximum and minimum activity of 77.0 and 15.13 μmoL mg−1 h−1. For nitrogenase activity among the studied strains, CoA6 fixed higher and AY1 fixed lower in amounts (108.30 and 6.16 μmoL C2H2 h−1 mL−1). All the strains were identified on the basis of 16S rRNA gene sequencing, and the phylogenetic diversity of the strains was analyzed. The results identified all strains as being similar to Pseudomonas spp. Polymerase chain reaction (PCR) amplification of nifH and antibiotic genes was suggestive that the amplified strains had the capability to fix nitrogen and possessed biocontrol activities. Genotypic comparisons of the strains were determined by BOX, ERIC, and REP PCR profile analysis. Out of all the screened isolates, CY4 (Pseudomonas koreensis) and CN11 (Pseudomonas entomophila) showed the most prominent PGP traits, as well as nitrogenase activity. Therefore, only these two strains were selected for further studies; Biolog profiling; colonization through green fluorescent protein (GFP)-tagged bacteria; and nifH gene expression using quantitative real-time polymerase chain reaction (qRT-PCR) analysis. The Biolog phenotypic

Genetic Diversity of Nitrogen-Fixing and Plant Growth Promoting Pseudomonas Species Isolated from Sugarcane Rhizosphere.

PubMed

Li, Hai-Bi; Singh, Rajesh K; Singh, Pratiksha; Song, Qi-Qi; Xing, Yong-Xiu; Yang, Li-Tao; Li, Yang-Rui

2017-01-01

The study was designed to isolate and characterize Pseudomonas spp. from sugarcane rhizosphere, and to evaluate their plant- growth- promoting (PGP) traits and nitrogenase activity. A biological nitrogen-fixing microbe has great potential to replace chemical fertilizers and be used as a targeted biofertilizer in a plant. A total of 100 isolates from sugarcane rhizosphere, belonging to different species, were isolated; from these, 30 isolates were selected on the basis of preliminary screening, for in vitro antagonistic activities against sugarcane pathogens and for various PGP traits, as well as nitrogenase activity. The production of IAA varied from 312.07 to 13.12 μg mL -1 in tryptophan supplemented medium, with higher production in AN15 and lower in CN20 strain. The estimation of ACC deaminase activity, strains CY4 and BA2 produced maximum and minimum activity of 77.0 and 15.13 μmoL mg -1 h -1 . For nitrogenase activity among the studied strains, CoA6 fixed higher and AY1 fixed lower in amounts (108.30 and 6.16 μmoL C 2 H 2 h -1 mL -1 ). All the strains were identified on the basis of 16S rRNA gene sequencing, and the phylogenetic diversity of the strains was analyzed. The results identified all strains as being similar to Pseudomonas spp. Polymerase chain reaction (PCR) amplification of nifH and antibiotic genes was suggestive that the amplified strains had the capability to fix nitrogen and possessed biocontrol activities. Genotypic comparisons of the strains were determined by BOX, ERIC, and REP PCR profile analysis. Out of all the screened isolates, CY4 ( Pseudomonas koreensis ) and CN11 ( Pseudomonas entomophila ) showed the most prominent PGP traits, as well as nitrogenase activity. Therefore, only these two strains were selected for further studies; Biolog profiling; colonization through green fluorescent protein (GFP)-tagged bacteria; and nifH gene expression using quantitative real-time polymerase chain reaction (qRT-PCR) analysis. The Biolog

Characterizing the Catalytic Potential of Deinococcus, Arthrobacter and other Robust Bacteria in Contaminated Subsurface Environments of the Hanford Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fredrickson, Jim K.; Daly, Michael J.

2006-06-01

Until recently, there have been no clear physiologic predictors of a cell's ability to recover from ionizing radiation (IR), desiccation, and other DOE-relevant oxidative stress conditions. In general, the most resistant bacteria have been Gram-positive (e.g., Deinococcus, Arthrobacter, Lactobacillus & Enterococcus spp.) and the most sensitive have been Gram-negative (e.g., Pseudomonas, Shewanella & Neisseria spp.). However, there are several reported exceptions to this paradigm, the Gram-negative cyanobacterium Chroococcidiopsis is extremely resistant to IR, whereas the Gram-positive Micrococcus luteus is sensitive. We have identified biomolecular signatures for radiation sensitivity and resistance which are independent of phylogeny, where very high and verymore » low intracellular Mn/Fe concentration ratios correlated with very high and very low resistances, respectively; and restricting Mn(II) in the famously resistant Deinococcus radiodurans sensitized this eubacterium to IR (http://cfyn.ifas.ufl.edu/radiation.pdf).« less

16S Ribosomal DNA Characterization of Nitrogen-Fixing Bacteria Isolated from Banana (Musa spp.) and Pineapple (Ananas comosus (L.) Merril)

PubMed Central

Magalhães Cruz, Leonardo; Maltempi de Souza, Emanuel; Weber, Olmar Baler; Baldani, José Ivo; Döbereiner, Johanna; de Oliveira Pedrosa, Fábio

2001-01-01

Nitrogen-fixing bacteria isolated from banana (Musa spp.) and pineapple (Ananas comosus (L.) Merril) were characterized by amplified 16S ribosomal DNA restriction analysis and 16S rRNA sequence analysis. Herbaspirillum seropedicae, Herbaspirillum rubrisubalbicans, Burkholderia brasilensis, and Burkholderia tropicalis were identified. Eight other types were placed in close proximity to these genera and other alpha and beta Proteobacteria. PMID:11319127

[The effect of biyuanshu oral liquid on the formation of Pseudomonas aeruginosa biofilms in vitro].

PubMed

Liu, Xiang; Chen, Haihong; Wang, Shengqing

2012-07-01

To observe the effect of biyuanshu oral liquid on the formation of pseudomonas aeruginosa biofilms in vitro. Pseudomonas aeruginosa biofilm was established by plate culture and detected by Scanning electron microscopy and AgNO3 staining. After treated with different dosages of biyuanshu oral liquid and erythromycin, the pseudomonas aeruginosa biofilms were observed by AgNO3 staining and the number of viable bacteria were measured by serial dilution. The pseudomonas aeruginosa biofilms could be detected by SEM at the seventh culture day and it was consistent with the detection of AgNO3 staining. The biyuanshu oral liquid and erythromycin have the effect on inhibiting the formation of pseudomonas aeruginosa biofilms. But with the already formed pseudomonas aeruginosa biofilms the inhibition was not significant. The serial dilution method showed that the viable counts of bacteria of biyuanshu oral liquid and erythromycin treated groups were significantly lower than those untreated groups (P < 0.05). The biyuanshu oral liquid and erythromycin can inhibit the formation of pseudomonas aeruginosa biofilms in vitro.

Isolation of Bacteria with Antifungal Activity against the Phytopathogenic Fungi Stenocarpella maydis and Stenocarpella macrospora

PubMed Central

Petatán-Sagahón, Iván; Anducho-Reyes, Miguel Angel; Silva-Rojas, Hilda Victoria; Arana-Cuenca, Ainhoa; Tellez-Jurado, Alejandro; Cárdenas-Álvarez, Isabel Oyuki; Mercado-Flores, Yuridia

2011-01-01

Stenocarpella maydis and Stenocarpella macrospora are the causal agents of ear rot in corn, which is one of the most destructive diseases in this crop worldwide. These fungi are important mycotoxin producers that cause different pathologies in farmed animals and represent an important risk for humans. In this work, 160 strains were isolated from soil of corn crops of which 10 showed antifungal activity against these phytopathogens, which, were identified as: Bacillus subtilis, Pseudomonas spp., Pseudomonas fluorescens, and Pantoea agglomerans by sequencing of 16S rRNA gene and the phylogenetic analysis. From cultures of each strain, extracellular filtrates were obtained and assayed to determine antifungal activity. The best filtrates were obtained in the stationary phase of B. subtilis cultures that were stable to the temperature and extreme pH values; in addition they did not show a cytotoxicity effect against brine shrimp and inhibited germination of conidia. The bacteria described in this work have the potential to be used in the control of white ear rot disease. PMID:22016606

Draft Genome Sequences of Seven Thermophilic Spore-Forming Bacteria Isolated from Foods That Produce Highly Heat-Resistant Spores, Comprising Geobacillus spp., Caldibacillus debilis, and Anoxybacillus flavithermus

PubMed Central

Berendsen, Erwin M.; Wells-Bennik, Marjon H. J.; Krawczyk, Antonina O.; de Jong, Anne; van Heel, Auke; Holsappel, Siger; Eijlander, Robyn T.

2016-01-01

Here, we report the draft genomes of five strains of Geobacillus spp., one Caldibacillus debilis strain, and one draft genome of Anoxybacillus flavithermus, all thermophilic spore-forming Gram-positive bacteria. PMID:27151781

Fungal disease prevention in seedlings of rice (Oryza sativa) and other grasses by growth-promoting seed-associated endophytic bacteria from invasive Phragmites australis

USGS Publications Warehouse

Verma, Satish K.; Kingsley, Kathryn L.; Bergen, Marshall S.; Kowalski, Kurt P.; White, James F.

2018-01-01

Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium, Pythium and other water moulds cause seed rots during germination. Fusariumblights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass (Cynodon dactylon), or annual bluegrass (Poa annua) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum. We found that three bacteria belonging to genus Pseudomonas spp. (SLB4-P. fluorescens, SLB6-Pseudomonas sp. and SY1-Pseudomonassp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum, 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production

Endocarditis Due to Rare and Fastidious Bacteria

PubMed Central

Brouqui, P.; Raoult, D.

2001-01-01

The etiologic diagnosis of infective endocarditis is easily made in the presence of continuous bacteremia with gram-positive cocci. However, the blood culture may contain a bacterium rarely associated with endocarditis, such as Lactobacillus spp., Klebsiella spp., or nontoxigenic Corynebacterium, Salmonella, Gemella, Campylobacter, Aeromonas, Yersinia, Nocardia, Pasteurella, Listeria, or Erysipelothrix spp., that requires further investigation to establish the relationship with endocarditis, or the blood culture may be uninformative despite a supportive clinical evaluation. In the latter case, the etiologic agents are either fastidious extracellular or intracellular bacteria. Fastidious extracellular bacteria such as Abiotrophia, HACEK group bacteria, Clostridium, Brucella, Legionella, Mycobacterium, and Bartonella spp. need supplemented media, prolonged incubation time, and special culture conditions. Intracellular bacteria such as Coxiella burnetii cannot be isolated routinely. The two most prevalent etiologic agents of culture-negative endocarditis are C. burnetti and Bartonella spp. Their diagnosis is usually carried out serologically. A systemic pathologic examination of excised heart valves including periodic acid-Schiff (PAS) staining and molecular methods has allowed the identification of Whipple's bacillus endocarditis. Pathologic examination of the valve using special staining, such as Warthin-Starry, Gimenez, and PAS, and broad-spectrum PCR should be performed systematically when no etiologic diagnosis is evident through routine laboratory evaluation. PMID:11148009

Bacteriophage therapy for refractory Pseudomonas aeruginosa urinary tract infection.

PubMed

Khawaldeh, A; Morales, S; Dillon, B; Alavidze, Z; Ginn, A N; Thomas, L; Chapman, S J; Dublanchet, A; Smithyman, A; Iredell, J R

2011-11-01

We describe the success of adjunctive bacteriophage therapy for refractory Pseudomonas aeruginosa urinary tract infection in the context of bilateral ureteric stents and bladder ulceration, after repeated failure of antibiotics alone. No bacteriophage-resistant bacteria arose, and the kinetics of bacteriophage and bacteria in urine suggest self-sustaining and self-limiting infection.

Pseudomonas biofilm matrix composition and niche biology

PubMed Central

Mann, Ethan E.; Wozniak, Daniel J.

2014-01-01

Biofilms are a predominant form of growth for bacteria in the environment and in the clinic. Critical for biofilm development are adherence, proliferation, and dispersion phases. Each of these stages includes reinforcement by, or modulation of, the extracellular matrix. Pseudomonas aeruginosa has been a model organism for the study of biofilm formation. Additionally, other Pseudomonas species utilize biofilm formation during plant colonization and environmental persistence. Pseudomonads produce several biofilm matrix molecules, including polysaccharides, nucleic acids, and proteins. Accessory matrix components shown to aid biofilm formation and adaptability under varying conditions are also produced by pseudomonads. Adaptation facilitated by biofilm formation allows for selection of genetic variants with unique and distinguishable colony morphology. Examples include rugose small-colony variants and wrinkly spreaders (WS), which over produce Psl/Pel or cellulose, respectively, and mucoid bacteria that over produce alginate. The well-documented emergence of these variants suggests that pseudomonads take advantage of matrix-building subpopulations conferring specific benefits for the entire population. This review will focus on various polysaccharides as well as additional Pseudomonas biofilm matrix components. Discussions will center on structure–function relationships, regulation, and the role of individual matrix molecules in niche biology. PMID:22212072

An Interspecies Signaling System Mediated by Fusaric Acid Has Parallel Effects on Antifungal Metabolite Production by Pseudomonas protegens Strain Pf-5 and Antibiosis of Fusarium spp.

PubMed

Quecine, Maria Carolina; Kidarsa, Teresa A; Goebel, Neal C; Shaffer, Brenda T; Henkels, Marcella D; Zabriskie, T Mark; Loper, Joyce E

2015-12-11

Pseudomonas protegens strain Pf-5 is a rhizosphere bacterium that suppresses soilborne plant diseases and produces at least seven different secondary metabolites with antifungal properties. We derived mutants of Pf-5 with single and multiple mutations in biosynthesis genes for seven antifungal metabolites: 2,4-diacetylphoroglucinol (DAPG), pyrrolnitrin, pyoluteorin, hydrogen cyanide, rhizoxin, orfamide A, and toxoflavin. These mutants were tested for inhibition of the pathogens Fusarium verticillioides and Fusarium oxysporum f. sp. pisi. Rhizoxin, pyrrolnitrin, and DAPG were found to be primarily responsible for fungal antagonism by Pf-5. Previously, other workers showed that the mycotoxin fusaric acid, which is produced by many Fusarium species, including F. verticillioides, inhibited the production of DAPG by Pseudomonas spp. In this study, amendment of culture media with fusaric acid decreased DAPG production, increased pyoluteorin production, and had no consistent influence on pyrrolnitrin or orfamide A production by Pf-5. Fusaric acid also altered the transcription of biosynthetic genes, indicating that the mycotoxin influenced antibiotic production by Pf-5 at the transcriptional level. Addition of fusaric acid to the culture medium reduced antibiosis of F. verticillioides by Pf-5 and derivative strains that produce DAPG but had no effect on antibiosis by Pf-5 derivatives that suppressed F. verticillioides due to pyrrolnitrin or rhizoxin production. Our results demonstrated the importance of three compounds, rhizoxin, pyrrolnitrin, and DAPG, in suppression of Fusarium spp. by Pf-5 and confirmed that an interspecies signaling system mediated by fusaric acid had parallel effects on antifungal metabolite production and antibiosis by the bacterial biological control organism. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Isolation and identification of bacteria causing mastitis in small ruminants and their susceptibility to antibiotics, honey, essential oils, and plant extracts

PubMed Central

Abdalhamed, Abeer Mostafa; Zeedan, Gamil Sayed Gamil; Zeina, Hala Abdoula Ahmed Abou

2018-01-01

Aim: The present work aims to isolate and identify bacteria that cause mastitis in small ruminants and evaluates the antibacterial activity of some antibiotics, honey, essential oils, and plant extracts. Materials and Methods: A total of 289 milk samples were collected from udder secretions of sheep (n=189) and goat (n=100) from El-Fayoum, Beni-Suef, and Giza governorates. Screening subclinical mastitis (SCM) was done using California Mastitis Test (CMT); identification of the isolates was achieved using Gram’s staining, hemolytic pattern, colony morphology, and biochemical tests using Analytical Profile Index. Results: On clinical examination, the incidence of clinical mastitis (CM) was found to be 5.88% and 7% in sheep and goat, respectively. On CMT, SCM was found to be 25 (13.23%) and 11 (10%) in sheep and goat, respectively. Bacteriological examination of all milk samples found the presence of Staphylococcus aureus (SA) (31.1%), coagulase-negative staphylococci (CNS) (19.5%), Escherichia coli (EC) (8.3%), Streptococcus spp. (5.6%), Klebsiella spp. (3.77%), and Pseudomonas spp. (1.89%), while no bacteria were cultured from 81.66% of the samples. Identification of 9 isolates of CNS was achieved by using API staph test to Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus cohnii, and Staphylococcus saprophyticus. The highest bacterial resistance was found in EC (67.14%) followed by Kp (45.28%) and SA (26.57%). Conclusion: Onion and black cumin essential oils followed by Egyptian honey showed strong antibacterial effects against multidrug-resistant bacteria. Finally, our study proved that Egyptian honey, onion, and black cumin essential oils have a marked strong antibacterial effect against bacteria isolated from small ruminant mastitis, but still further extensive studies are needed to discover the therapeutic properties of these plant extracts and honey. PMID:29657429

Assessment of potential probiotic properties of Lactobacillus spp., Lactococcus spp., and Pediococcus spp. strains isolated from kefir.

PubMed

Sabir, Firat; Beyatli, Yavuz; Cokmus, Cumhur; Onal-Darilmaz, Derya

2010-01-01

In this study, the metabolic activities (in terms of quantities of the produced lactic acid, hydrogen peroxide, and exopolysaccharides) of 8 strains of Lactobacillus spp., Lactococcus spp., and Pediococcus spp., were determined. Lactic acid levels produced by strains were 8.1 to 17.4 mg/L. The L. acidophilus Z1L strain produced the maximum amount (3.18 μg/mL) of hydrogen peroxide. The exopolysaccharides (EPS) production by the strains was ranged between 173 and 378 mg/L. The susceptibility of 7 different antibiotics against these strains was also tested. All strains were found to be sensitive to ampicillin. The tolerance of the strains to low pH, their resistance to bile salts of strains, and their abilities to autoaggregate and coaggregate with Escherichia coli ATCC 11229 were also evaluated. High EPS-producing strains showed significant autoaggregation and coaggregation ability with test bacteria (P < 0.01). A correlation also was determined between EPS production and acid-bile tolerance (P < 0.05). EPS production possibly affects or is involved in acid-bile tolerance and aggregation of Lactobacillus spp., Lactococcus spp., and Pediococcus spp. strains and supports the potential of L. acidophilus Z1L strain as new probiotic. © 2010 Institute of Food Technologists®

Influence of solid state fermentation by Trichoderma spp. on solubility, phenolic content, antioxidant, and antimicrobial activities of commercial turmeric.

PubMed

Mohamed, Saleh A; Saleh, Rashad M; Kabli, Saleh A; Al-Garni, Saleh M

2016-05-01

The influence of solid state fermentation (SSF) by Trichoderma spp. on the solubility, total phenolic content, antioxidant, and antibacterial activities of turmeric was determined and compared with unfermented turmeric. The solubility of turmeric was monitored by increase in its phenolic content. The total phenolic content of turmeric extracted by 80% methanol and water after SSF by six species of Trichoderma spp. increased significantly from 2.5 to 11.3-23.3 and from 0.5 to 13.5-20.4 GAE/g DW, respectively. The antioxidant activities of fermented turmeric were enhanced using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid) (ABTS), and ferric ion-reducing antioxidant power (FRAP) assays. The antibacterial activity of fermented turmeric against human-pathogenic bacteria Escherichia coli, Streptococcus agalactiae, Staphylococcus aureus, Entreococcus faecalis, Methicillin-Resistant S. aureus, Klebsiella pneumonia, and Pseudomonas aeruginosae showed a broad spectrum inhibitory effect. In conclusion, the results indicated the potentials of using fermented turmeric as natural antioxidant and antimicrobial material for food applications.

Mycorrhization between Cistus ladanifer L. and Boletus edulis Bull is enhanced by the mycorrhiza helper bacteria Pseudomonas fluorescens Migula.

PubMed

Mediavilla, Olaya; Olaizola, Jaime; Santos-del-Blanco, Luis; Oria-de-Rueda, Juan Andrés; Martín-Pinto, Pablo

2016-02-01

Boletus edulis Bull. is one of the most economically and gastronomically valuable fungi worldwide. Sporocarp production normally occurs when symbiotically associated with a number of tree species in stands over 40 years old, but it has also been reported in 3-year-old Cistus ladanifer L. shrubs. Efforts toward the domestication of B. edulis have thus focused on successfully generating C. ladanifer seedlings associated with B. edulis under controlled conditions. Microorganisms have an important role mediating mycorrhizal symbiosis, such as some bacteria species which enhance mycorrhiza formation (mycorrhiza helper bacteria). Thus, in this study, we explored the effect that mycorrhiza helper bacteria have on the efficiency and intensity of the ectomycorrhizal symbiosis between C. ladanifer and B. edulis. The aim of this work was to optimize an in vitro protocol for the mycorrhizal synthesis of B. edulis with C. ladanifer by testing the effects of fungal culture time and coinoculation with the helper bacteria Pseudomonas fluorescens Migula. The results confirmed successful mycorrhizal synthesis between C. ladanifer and B. edulis. Coinoculation of B. edulis with P. fluorescens doubled within-plant mycorrhization levels although it did not result in an increased number of seedlings colonized with B. edulis mycorrhizae. B. edulis mycelium culture time also increased mycorrhization levels but not the presence of mycorrhizae. These findings bring us closer to controlled B. edulis sporocarp production in plantations.

Discrimination of selected species of pathogenic bacteria using near-infrared Raman spectroscopy and principal components analysis

NASA Astrophysics Data System (ADS)

de Siqueira e Oliveira, Fernanda SantAna; Giana, Hector Enrique; Silveira, Landulfo

2012-10-01

A method, based on Raman spectroscopy, for identification of different microorganisms involved in bacterial urinary tract infections has been proposed. Spectra were collected from different bacterial colonies (Gram-negative: Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa and Enterobacter cloacae, and Gram-positive: Staphylococcus aureus and Enterococcus spp.), grown on culture medium (agar), using a Raman spectrometer with a fiber Raman probe (830 nm). Colonies were scraped from the agar surface and placed on an aluminum foil for Raman measurements. After preprocessing, spectra were submitted to a principal component analysis and Mahalanobis distance (PCA/MD) discrimination algorithm. We found that the mean Raman spectra of different bacterial species show similar bands, and S. aureus was well characterized by strong bands related to carotenoids. PCA/MD could discriminate Gram-positive bacteria with sensitivity and specificity of 100% and Gram-negative bacteria with sensitivity ranging from 58 to 88% and specificity ranging from 87% to 99%.

Isolation and Identification of cellulolytic bacteria from mangrove sediment in Bangka Island

NASA Astrophysics Data System (ADS)

Kurniawan, A.; Prihanto, A. A.; Sari, S. P.; Febriyanti, D.; Kurniawan, A.; Sambah, A. B.; Asriani, E.

2018-04-01

Cellulolytic bacteria is bacteria which hydrolyze cellulose to reducing sugars. This research aims to obtain cellulolytic bacteria from the sediment of mangroves in Bangka island. Reasearch was conducted from March to August 2017. Sampling was conducted at Sungailiat, and Tukak Sadai, South of Bangka. Bacteria was isolated using 1% Carboxymetyl Cellulosa (CMC). The isolation resulted in four isolates from Sungailiat and nine isolates from Tukak Sadai. Total five isolates, namely Bacillus pumilus, Pseudomonas sp., Bacillus amyloliquefacien, Bacillus alvei, Bacillus coagulant were identified. The best isolates that produced cellulose was Pseudomonas aeruginosa.

Lignocellulolytic enzymes and bacteria associated with the digestive tracts of Stenochironomus (Diptera: Chironomidae) larvae.

PubMed

Koroiva, R; Souza, C W O; Toyama, D; Henrique-Silva, F; Fonseca-Gessner, A A

2013-04-02

We analyzed the digestive activity of the enzymes that digest cellulose and hemicellulose and the bacterial community that is capable of hydrolyzing wood compounds in the digestive tracts of Stenochironomus (Diptera: Chironomidae) larvae, which are miners of decomposing submerged tree and bush branches. Based on quantification of reducing sugars, these larvae have a limited capacity for cellulose degradation but a good capacity for xylan hydrolysis. We isolated 31 types of colonies from two larval morphotypes, of which 19 tested positive for the capacity to hydrolyze at least one of the four substrates that were used as the main carbon source in the culture media. Their woody compound degradation capacity was assessed using colorimetric tests. The bacteria were identified by the analysis of the 16S rRNA gene. None of the bacteria were capable of degrading lignin. The genus Pseudomonas had the greatest species richness; Bacillus spp exhibited the greatest capacity for degrading the different substrates, and Sphingobium was found in both morphotypes. Microorganisms participate in the degradation of wood consumed by Stenochironomus larvae. This is the first report of lignocellulolytic bacteria and enzymes in the digestive tracts of mining chironomids.

Bio-protective potential of lactic acid bacteria: Effect of Lactobacillus sakei and Lactobacillus curvatus on changes of the microbial community in vacuum-packaged chilled beef.

PubMed

Zhang, Yimin; Zhu, Lixian; Dong, Pengcheng; Liang, Rongrong; Mao, Yanwei; Qiu, Shubing; Luo, Xin

2018-04-01

This study was to determine the bacterial diversity and monitor the community dynamic changes during storage of vacuum-packaged sliced raw beef as affected by Lactobacillus sakei and Lactobacillus curvatus . L. sakei and L. curvatus were separately incubated in vacuumed-packaged raw beef as bio-protective cultures to inhibit the naturally contaminating microbial load. Dynamic changes of the microbial diversity of inoculated or non-inoculated (control) samples were monitored at 4°C for 0 to 38 days, using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The DGGE profiles of DNA directly extracted from non-inoculated control samples highlighted the order of appearance of spoilage bacteria during storage, showing that Enterbacteriaceae and Pseudomonas fragi emerged early, then Brochothrix thermosphacta shared the dominant position, and finally, Pseudomonas putida showed up became predominant. Compared with control, the inoculation of either L. sakei or L. curvatus significantly lowered the complexity of microbial diversity and inhibited the growth of spoilage bacteria (p<0.05). Interestingly, we also found that the dominant position of L. curvatus was replaced by indigenous L. sakei after 13 d for L. curvatus -inoculated samples. Plate counts on selective agars further showed that inoculation with L. sakei or L. curvatus obviously reduced the viable counts of Enterbacteraceae , Pseudomonas spp. and B. thermosphacta during later storage (p< 0.05), with L. sakei exerting greater inhibitory effect. Inoculation with both bio-protective cultures also significantly decreased the total volatile basic nitrogen values of stored samples (p<0.05). Taken together, the results proved the benefits of inoculation with lactic acid bacteria especially L. sakei as a potential way to inhibit growth of spoilage-related bacteria and improve the shelf life of vacuum-packaged raw beef.

Bio-protective potential of lactic acid bacteria: Effect of Lactobacillus sakei and Lactobacillus curvatus on changes of the microbial community in vacuum-packaged chilled beef

PubMed Central

Zhang, Yimin; Zhu, Lixian; Dong, Pengcheng; Liang, Rongrong; Mao, Yanwei; Qiu, Shubing

2018-01-01

Objective This study was to determine the bacterial diversity and monitor the community dynamic changes during storage of vacuum-packaged sliced raw beef as affected by Lactobacillus sakei and Lactobacillus curvatus. Methods L. sakei and L. curvatus were separately incubated in vacuumed-packaged raw beef as bio-protective cultures to inhibit the naturally contaminating microbial load. Dynamic changes of the microbial diversity of inoculated or non-inoculated (control) samples were monitored at 4°C for 0 to 38 days, using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Results The DGGE profiles of DNA directly extracted from non-inoculated control samples highlighted the order of appearance of spoilage bacteria during storage, showing that Enterbacteriaceae and Pseudomonas fragi emerged early, then Brochothrix thermosphacta shared the dominant position, and finally, Pseudomonas putida showed up became predominant. Compared with control, the inoculation of either L. sakei or L. curvatus significantly lowered the complexity of microbial diversity and inhibited the growth of spoilage bacteria (p<0.05). Interestingly, we also found that the dominant position of L. curvatus was replaced by indigenous L. sakei after 13 d for L. curvatus-inoculated samples. Plate counts on selective agars further showed that inoculation with L. sakei or L. curvatus obviously reduced the viable counts of Enterbacteraceae, Pseudomonas spp. and B. thermosphacta during later storage (p< 0.05), with L. sakei exerting greater inhibitory effect. Inoculation with both bio-protective cultures also significantly decreased the total volatile basic nitrogen values of stored samples (p<0.05). Conclusion Taken together, the results proved the benefits of inoculation with lactic acid bacteria especially L. sakei as a potential way to inhibit growth of spoilage-related bacteria and improve the shelf life of vacuum-packaged raw beef. PMID:29059725

Localization of Burkholderia cepacia Complex Bacteria in Cystic Fibrosis Lungs and Interactions with Pseudomonas aeruginosa in Hypoxic Mucus

PubMed Central

Abdullah, Lubna H.; Perlmutt, Olivia S.; Albert, Daniel; Davis, C. William; Arnold, Roland R.; Yankaskas, James R.; Gilligan, Peter; Neubauer, Heiner; Randell, Scott H.; Boucher, Richard C.

2014-01-01

The localization of Burkholderia cepacia complex (Bcc) bacteria in cystic fibrosis (CF) lungs, alone or during coinfection with Pseudomonas aeruginosa, is poorly understood. We performed immunohistochemistry for Bcc and P. aeruginosa bacteria on 21 coinfected or singly infected CF lungs obtained at transplantation or autopsy. Parallel in vitro experiments examined the growth of two Bcc species, Burkholderia cenocepacia and Burkholderia multivorans, in environments similar to those occupied by P. aeruginosa in the CF lung. Bcc bacteria were predominantly identified in the CF lung as single cells or small clusters within phagocytes and mucus but not as “biofilm-like structures.” In contrast, P. aeruginosa was identified in biofilm-like masses, but densities appeared to be reduced during coinfection with Bcc bacteria. Based on chemical analyses of CF and non-CF respiratory secretions, a test medium was defined to study Bcc growth and interactions with P. aeruginosa in an environment mimicking the CF lung. When test medium was supplemented with alternative electron acceptors under anaerobic conditions, B. cenocepacia and B. multivorans used fermentation rather than anaerobic respiration to gain energy, consistent with the identification of fermentation products by high-performance liquid chromatography (HPLC). Both Bcc species also expressed mucinases that produced carbon sources from mucins for growth. In the presence of P. aeruginosa in vitro, both Bcc species grew anaerobically but not aerobically. We propose that Bcc bacteria (i) invade a P. aeruginosa-infected CF lung when the airway lumen is anaerobic, (ii) inhibit P. aeruginosa biofilm-like growth, and (iii) expand the host bacterial niche from mucus to also include macrophages. PMID:25156735

Methylobacterium spp. as an indicator for the presence or absence of Mycobacterium spp.

PubMed

Falkinham, Joseph O; Williams, Myra D; Kwait, Rebecca; Lande, Leah

2016-06-01

A published survey of bacteria in showerhead biofilm samples revealed that Methylobacterium spp. and Mycobacterium spp. seldom coexisted in biofilms. To confirm that information, biofilm samples were collected from household plumbing of Mycobacterium avium patients and Methylobacterium spp. and M. avium numbers were measured by direct colony counts. The results demonstrated that if Methylobacterium spp. were present, Mycobacterium spp. were absent, and the opposite. The data demonstrate that microbial populations in biofilms can influence the presence or absence of opportunistic premise plumbing pathogens and, thereby, increase the range of strategies to reduce exposure to waterborne pathogens. Finally, by assessing for the visual presence of methylobacteria as pink pigmentation on showers and shower curtains, homeowners and managers of hospitals and other buildings can quickly determine whether a premise plumbing biofilm sample has mycobacteria with a high degree of assurance. Copyright © 2016 Asian African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

Pseudomonas sax genes overcome aliphatic isothiocyanate-mediated non-host resistance in Arabidopsis

Treesearch

Jun Fan; Casey Crooks; Gary Creissen; Lionel Hill; Shirley Fairhurst; Peter Doerner; Chris Lamb

2011-01-01

Most plant-microbe interactions do not result in disease; natural products restrict non-host pathogens. We found that sulforaphane (4-methylsulfinylbutyl isothiocyanate), a natural product derived from aliphatic glucosinolates, inhibits growth in Arabidopsis of non-host Pseudomonas bacteria in planta. Multiple sax genes (saxCAB/F/D/G) were identified in Pseudomonas...

Characterization of N2-fixing plant growth promoting endophytic and epiphytic bacterial community of Indian cultivated and wild rice (Oryza spp.) genotypes.

PubMed

Banik, Avishek; Mukhopadhaya, Subhra Kanti; Dangar, Tushar Kanti

2016-03-01

The diversity of endophytic and epiphytic diazotrophs in different parts of rice plants has specificity to the niche (i.e. leaf, stem and root) of different genotypes and nutrient availability of the organ. Inoculation of the indigenous, polyvalent diazotrophs can facilitate and sustain production of non-leguminous crops like rice. Therefore, N2-fixing plant growth promoting bacteria (PGPB) were isolated from different parts of three Indian cultivated [Oryza sativa L. var. Sabita (semi deep/deep water)/Swarna (rain fed shallow lowland)/Swarna-Sub1(submergence tolerant)] and a wild (O. eichingeri) rice genotypes which respond differentially to nitrogenous fertilizers. Thirty-five isolates from four rice genotypes were categorized based on acetylene reduction assay on nitrogenase activity, biochemical tests, BIOLOG and 16S rRNA gene sequencing. The bacteria produced 9.36-155.83 nmole C2H4 mg(-1) dry bacteria h(-1) and among them nitrogenase activity of 11 potent isolates was complemented by nifH-sequence analysis. Phylogenetic analysis based on 16S rDNA sequencing divided them into five groups (shared 95-100 % sequence homology with type strains) belonging to five classes-alpha (Ancylobacter, Azorhizobium, Azospirillum, Rhizobium, Bradyrhizobium, Sinorhizobium, Novosphingobium, spp.), beta (Burkholderia sp.), gamma (Acinetobacter, Aeromonas, Azotobacter, Enterobacter, Klebsiella, Pantoea, Pseudomonas, Stenotrophomonas spp.) Proteobacteria, Bacilli (Bacillus, Paenibacillus spp.) and Actinobacteria (Microbacterium sp.). Besides, all bacterial strains possessed the intrinsic PGP traits of like indole (0.44-7.4 µg ml(-1)), ammonia (0.18-6 mmol ml(-1)), nitrite (0.01-3.4 mol ml(-1)), and siderophore (from 0.16-0.57 μmol ml(-1)) production. Inoculation of rice (cv. Swarna) seedlings with selected isolates had a positive impact on plant growth parameters like shoot and root elongation which was correlated with in vitro PGP attributes. The results indicated that the

[Comparative studying of anaerobic bacteria located in woman's reproductive ways in normal condition and dysbiosis].

PubMed

Polishko, T N; Sirokvasha, E A; Klokov, V V; Vinnikov, A I

2008-01-01

Bacteriological investigation of obligate anaerobic bacteria located in UGT of two groups of the observed women has shown: that the microbiocoenosis of UGT of women of the group 1 can be determined as normal. Identification of these anaerobic bacteria revealed the presence of representatives of the following species: Lactobacillus spp., Bifidobacterium spp., Eubacterium spp., Bacteroides spp., Fusobacterium spp., Peptococcus spp., Peptostreptococcus spp. The microbiocoenosis of UGT of the women of group 2 is diagnosed as vaginosis, thus in addition to the listed previously bacteria is added another one, Clostridium spp. Characteristic feature of Vaginosis is from one side a considerable decrease in the frequency of finding (cultivation) and concentration of Lactobacillus spp. and Bifidobacterium spp. and from another side--a considerable increase of frequency finding (cultivation) and concentration of Bacteroides spp. In addition, there is change of metabolism of Lactobacillus spp. and Bifidobacterium spp resulting in decrease in specific intensity of secretion of acids.

Survival of Salmonella spp. and fecal indicator bacteria in Vietnamese biogas digesters receiving pig slurry.

PubMed

Huong, Luu Quynh; Forslund, Anita; Madsen, Henry; Dalsgaard, Anders

2014-09-01

Small-scale biogas digesters are widely promoted worldwide as a sustainable technology to manage livestock manure. In Vietnam, pig slurry is commonly applied to biogas digesters for production of gas for electricity and cooking with the effluent being used to fertilize field crops, vegetables and fish ponds. Slurry may contain a variety of zoonotic pathogens, e.g. Salmonella spp., which are able to cause disease in humans either through direct contact with slurry or by fecal contamination of water and foods. The objective of this study was to evaluate the survival of Salmonella spp. and the fecal indicator bacteria, enterococci, E. coli, and spores of Clostridium perfringens in biogas digesters operated by small-scale Vietnamese pig farmers. The serovar and antimicrobial susceptibility of the Salmonella spp. isolated were also established. The study was conducted in 12 farms (6 farms with and 6 farms without toilet connected) located in Hanam province, Vietnam. Sampling of pig slurry and biogas effluent was done during two seasons. Results showed that the concentration of enterococci, E. coli, and Clostridium perfringens spores was overall reduced by only 1-2 log10-units in the biogas digesters when comparing raw slurry and biogas effluent. Salmonella spp. was found in both raw slurry and biogas effluent. A total of 19 Salmonella serovars were identified, with the main serovars being Salmonella Typhimurium (55/138), Salmonella enterica serovar 4,[5],12:i:- (19/138), Salmonella Weltevreden (9/138) and Salmonella Rissen (9/138). The Salmonella serovars showed similar antimicrobial resistance patterns to those previously reported from Vietnam. When promoting biogas, farmers should be made aware that effluent should only be used as fertilizer for crops not consumed raw and that indiscriminate discharge of effluent are likely to contaminate water recipients, e.g. drinking water sources, with pathogens. Relevant authorities should promote safe animal manure management

Characterization of Pseudomonas pathovars isolated from rosaceous fruit trees in East Algeria.

PubMed

Harzallah, D; Sadallah, S; Larous, L

2004-01-01

A survey of bacterial diseases due to Pseudomonas on rosaceous fruit trees was conducted. In forty two orchards located in the Constantine region ( East Algeria). Pseudomonas isolates were identified on the bases of their cultural and biochemical characteristics . A total of fifty nine phytopathogenic bacteria were isolated from diseased pome and stone fruit trees. Thirty one strains comparable to Pseudomonas syringae pv. syringae were isolated from cherry (Prunus avium L.), plum (P. domestica L.), apricot (P. armeniaca L.), almond (P. dulcis L.) and pear trees (Pirus communis L.); sixteen strains comparable to Pseudomonas syringae pv. morsprunorum were obtained from samples of cherry and plum. Twelve strains of Pseudomonas viridiflava were isolated from cherry, apricot and peach (Prunus persica L.).

Influence of Storage Conditions on the Growth of Pseudomonas Species in Refrigerated Raw Milk▿ †

PubMed Central

De Jonghe, Valerie; Coorevits, An; Van Hoorde, Koenraad; Messens, Winy; Van Landschoot, Anita; De Vos, Paul; Heyndrickx, Marc

2011-01-01

The refrigerated storage of raw milk throughout the dairy chain prior to heat treatment creates selective conditions for growth of psychrotolerant bacteria. These bacteria, mainly belonging to the genus Pseudomonas, are capable of producing thermoresistant extracellular proteases and lipases, which can cause spoilage and structural defects in pasteurized and ultra-high-temperature-treated milk (products). To map the influence of refrigerated storage on the growth of these pseudomonads, milk samples were taken after the first milking turn and incubated laboratory scale at temperatures simulating optimal and suboptimal preprocessing storage conditions. The outgrowth of Pseudomonas members was monitored over time by means of cultivation-independent denaturing gradient gel electrophoresis (DGGE). Isolates were identified by a polyphasic approach. These incubations revealed that outgrowth of Pseudomonas members occurred from the beginning of the dairy chain (farm tank) under both optimal and suboptimal storage conditions. An even greater risk for outgrowth, as indicated by a vast increase of about 2 log CFU per ml raw milk, existed downstream in the chain, especially when raw milk was stored under suboptimal conditions. This difference in Pseudomonas outgrowth between optimal and suboptimal storage was already statistically significant within the farm tank. The predominant taxa were identified as Pseudomonas gessardii, Pseudomonas gessardii-like, Pseudomonas fluorescens-like, Pseudomonas lundensis, Pseudomonas fragi, and Pseudomonas fragi-like. Those taxa show an important spoilage potential as determined on elective media for proteolysis and lipolysis. PMID:21115713

Channel specificity and secondary structure of the glucose-inducible porins of Pseudomonas spp.

PubMed

Adewoye, L O; Tschetter, L; O'Neil, J; Worobec, E A

1998-06-01

The OprB porin-mediated glucose transport system was investigated in Pseudomonas chlororaphis, Burkholderia cepacia, and Pseudomonas fluorescens. Kinetic studies of [U-14C]glucose uptake revealed an inducible system of low Km values (0.3-5 microM) and high specificity for glucose. OprB homologs were purified and reconstituted into proteoliposomes. The porin function and channel preference for glucose were demonstrated by liposome swelling assays. Examination of the periplasmic glucose-binding protein (GBP) components by Western immunoblotting using P. aeruginosa GBP-specific antiserum revealed some homology between P. aeruginosa GBP and periplasmic proteins from P. fluorescens and P. chlororaphis but not B. cepacia. Circular dichroism spectropolarimetry of purified OprB-like porins from the three species revealed beta sheet contents of 31-50% in agreement with 40% beta sheet content for the P. aeruginosa OprB porin. These findings suggest that the high-affinity glucose transport system is primarily specific for glucose and well conserved in the genus Pseudomonas although its outer membrane component may differ in channel architecture and specificity for other carbohydrates.

Spoilage bacteria of fresh broiler chicken carcasses.

PubMed

Russell, S M; Fletcher, D L; Cox, N A

1995-12-01

Studies were conducted to identify the bacteria responsible for spoilage of fresh broiler chicken carcasses and to characterize the off-odors these bacteria produce. Broiler carcasses were collected from processing plants in the northeast Georgia area, the southeastern U.S., Arkansas, California, and North Carolina. The carcasses were allowed to spoil under controlled conditions at 3 C and spoilage bacteria were isolated. Each spoilage bacterium was separately inoculated into a sterile chicken skin medium, incubated at 25 C for 48 h, and subjectively evaluated for odor. The bacteria isolated from spoiled carcasses that consistently produced off-odors in the chicken skin medium, regardless of the geographical location from which the chickens were obtained, were Shewanella putrefaciens A, B, and D, Pseudomonas fluorescens A, B, and D, and Pseudomonas fragi. These bacteria produced off-odors that resembled "sulfur", "dishrag", "ammonia", "wet dog", "skunk", "dirty socks", "rancid fish", "unspecified bad odor", or a sweet smell resembling "canned corn". Odors produced by the spoilage bacteria were varied; however, odors most associated with spoiled poultry, such as "dishraggy" odors, were produced by the bacteria that were most consistently isolated, such as S. putrefaciens and the pseudomonads.

Quantitative Profiling of Colorectal Cancer-Associated Bacteria Reveals Associations between Fusobacterium spp., Enterotoxigenic Bacteroides fragilis (ETBF) and Clinicopathological Features of Colorectal Cancer

PubMed Central

Viljoen, Katie S.; Dakshinamurthy, Amirtha; Goldberg, Paul; Blackburn, Jonathan M.

2015-01-01

Various studies have presented clinical or in vitro evidence linking bacteria to colorectal cancer, but these bacteria have not previously been concurrently quantified by qPCR in a single cohort. We quantify these bacteria (Fusobacterium spp., Streptococcus gallolyticus, Enterococcus faecalis, Enterotoxigenic Bacteroides fragilis (ETBF), Enteropathogenic Escherichia coli (EPEC), and afaC- or pks-positive E. coli) in paired tumour and normal tissue samples from 55 colorectal cancer patients. We further investigate the relationship between a) the presence and b) the level of colonisation of each bacterial species with site and stage of disease, age, gender, ethnicity and MSI-status. With the exception of S. gallolyticus, we detected all bacteria profiled here in both tumour and normal samples at varying frequencies. ETBF (FDR = 0.001 and 0.002 for normal and tumour samples) and afaC-positive E. coli (FDR = 0.03, normal samples) were significantly enriched in the colon compared to the rectum. ETBF (FDR = 0.04 and 0.002 for normal and tumour samples, respectively) and Fusobacterium spp. (FDR = 0.03 tumour samples) levels were significantly higher in late stage (III/IV) colorectal cancers. Fusobacterium was by far the most common bacteria detected, occurring in 82% and 81% of paired tumour and normal samples. Fusobacterium was also the only bacterium that was significantly higher in tumour compared to normal samples (p = 6e-5). We also identified significant associations between high-level colonisation by Fusobacterium and MSI-H (FDR = 0.05), age (FDR = 0.03) or pks-positive E. coli (FDR = 0.01). Furthermore, we exclusively identified atypical EPEC in our cohort, which has not been previously reported in association with colorectal cancer. By quantifying colorectal cancer-associated bacteria across a single cohort, we uncovered inter- and intra-individual patterns of colonization not previously recognized, as well as important associations with clinicopathological

Discovery of Phloeophagus Beetles as a Source of Pseudomonas Strains That Produce Potentially New Bioactive Substances and Description of Pseudomonas bohemica sp. nov.

PubMed

Saati-Santamaría, Zaki; López-Mondéjar, Rubén; Jiménez-Gómez, Alejandro; Díez-Méndez, Alexandra; Větrovský, Tomáš; Igual, José M; Velázquez, Encarna; Kolarik, Miroslav; Rivas, Raúl; García-Fraile, Paula

2018-01-01

Antimicrobial resistance is a worldwide problem that threatens the effectiveness of treatments for microbial infection. Consequently, it is essential to study unexplored niches that can serve for the isolation of new microbial strains able to produce antimicrobial compounds to develop new drugs. Bark beetles live in phloem of host trees and establish symbioses with microorganisms that provide them with nutrients. In addition, some of their associated bacteria play a role in the beetle protection by producing substances that inhibit antagonists. In this study the capacity of several bacterial strains, isolated from the bark beetles Ips acuminatus, Pityophthorus pityographus Cryphalus piceae , and Pityogenes bidentatus , to produce antimicrobial compounds was analyzed. Several isolates exhibited the capacity to inhibit Gram-positive and Gram-negative bacteria, as well as fungi. The genome sequence analysis of three Pseudomonas isolates predicted the presence of several gene clusters implicated in the production of already described antimicrobials and moreover, the low similarity of some of these clusters with those previously described, suggests that they encode new undescribed substances, which may be useful for developing new antimicrobial agents. Moreover, these bacteria appear to have genetic machinery for producing antitumoral and antiviral substances. Finally, the strain IA19 T showed to represent a new species of the genus Pseudomonas . The 16S rRNA gene sequence analysis showed that its most closely related species include Pseudomonas lutea, Pseudomonas graminis, Pseudomonas abietaniphila and Pseudomonas alkylphenolica, with 98.6, 98.5 98.4, and 98.4% identity, respectively. MLSA of the housekeeping genes gyr B, rpo B, and rpo D confirmed that strain IA19 T clearly separates from its closest related species. Average nucleotide identity between strains IA19 T and P. abietaniphila ATCC 700689 T , P. graminis DSM 11363 T , P. alkylphenolica KL28 T and P. lutea

Structural and functional diversity of rhizobacteria associated with Rauwolfia spp. across the Western Ghat regions of Karnataka, India.

PubMed

Prasanna Kumar, S P; Hariprasad, P; Brijesh Singh, S; Gowtham, H G; Niranjana, S R

2014-01-01

The present study carried out with denaturing gradient gel electrophoresis of DNA extracted from rhizosphere soils of Rauwolfia spp. collected from Western Ghat (WG) regions of Karnataka indicated that Pseudomonas sp. was prevalently found followed by Methylobacterium sp., Bacillus sp. and uncultured bacteria. A total of 200 rhizobacteria were isolated from 58 rhizosphere soil samples comprising of 15 different bacterial genera. The Shannon Weaver diversity index (H') and Simpson's diversity index (D) were found to be 2.57 and 0.91 for cultivable bacteria, respectively. The total species richness of cultivable rhizobacteria was high in Coorg district comprising 15 bacterial genera while in Mysore district, four bacterial genera were recorded. Rarefaction curve analysis also indicated the presence of higher species richness in samples of Shimoga and Coorg. All the rhizobacteria were screened for their multiple plant growth promotion and disease suppression traits. The results revealed that 70% of the isolates colonized tomato roots, 42% produced indole acetic acid, 55% solubilized phosphorus, while 43, 22, 27, 19, 40, 15 and 44% produced siderophore, salicylic acid, hydrogen cyanide, chitinase, phytase, cellulase and protease, respectively. Rhizobacterial isolates showing antagonistic activity against Fusarium oxysporum and Aspergillus flavus were 53 and 33%, respectively. Plant growth promotion studies revealed that most of the isolates increased percent germination with significantly higher vigour index as compared to untreated control. Most predominant rhizobacteria found in the rhizospheres of Rauwolfia spp. of WG regions are potential PGPR which can serve as biofertilizers and biopesticides.

[Molecular characterization of pathogenic bacteria of the respiratory tract in peruvian patients with cystic fibrosis].

PubMed

Aquino, Ruth; Gonzáles, Emely; Samaniego, Sol; Rivera, Juan; Cedeño, Virna; Urbina, Yrene; Diringer, Benoit

2017-01-01

To molecularly characterize the pathogenic bacteria of the respiratory tract isolated from patients with cystic fibrosis (CF) in Peru. Bacterial communities cultured from sputum samples of pediatric and adult patients with CF admitted to the Edgardo Rebagliati Martins National Hospital and the National Institute of Child Health were characterized. Standard microbiological techniques were used for bacterial culture, and gene sequencing of 16S rRNA and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and tandem MALDI-TOF mass spectrometry (MALDI TOF/TOF) were used for molecular characterization. Seventeen bacterial strains were characterized by 16S rRNA sequencing, and the identified pathogenic bacteria were Pseudomonas aeruginosa (31.5%), Staphylococcus aureus (12.6%), Pseudomonas spp. (11.8%), and Klebsiella oxytoca (3.1%). MALDI-TOF analysis generated a series of spectra representative of each isolated bacterial species, whereas MALDI TOF/TOF analysis identified the peptides and proteins of the most common strains and provided data on pathogenicity and sensitivity to antibiotics. The primary pathogenic microorganisms found in the respiratory tract of patients with CF in Peru were the same as those found in other countries. This study is the first to perform 16S rRNA sequencing as well as MALDI-TOF and MALDI-TOF/TOF analysis of the bacterial pathogens circulating in Peru. The inclusion of proteomic analysis further allowed for the identification of native microorganisms involved in CF.

Whole-Genome Sequence of Pseudomonas fluorescens EK007-RG4, a Promising Biocontrol Agent against a Broad Range of Bacteria, Including the Fire Blight Bacterium Erwinia amylovora.

PubMed

Habibi, Roghayeh; Tarighi, Saeed; Behravan, Javad; Taheri, Parissa; Kjøller, Annelise Helene; Brejnrod, Asker; Madsen, Jonas Stenløkke; Sørensen, Søren Johannes

2017-03-30

Here, we report the first draft whole-genome sequence of Pseudomonas fluorescens strain EK007-RG4, which was isolated from the phylloplane of a pear tree. P. fluorescens EK007-RG4 displays strong antagonism against Erwinia amylovora , the causal agent for fire blight disease, in addition to several other pathogenic and non-pathogenic bacteria. Copyright © 2017 Habibi et al.

Ultrastructural characteristics of some bacteria after treatment with Lubrol W.

PubMed

Cherepova, N; Spasova, D

1994-01-01

Specific ultrastructural changes occurred mainly in the cell wall and cytoplasmic membrane of Listeria monocytogenes, Salmonella typhimurium, Pseudomonas pseudomallei and Pseudomonas aeruginosa bacteria when treated with 0.5% and 1% Lubrol W1 by means of transmission and scanning electron microscopy.

Biotransformation of trinitrotoluene (TNT) by Pseudomonas spp. isolated from a TNT-contaminated environment.

PubMed

Chien, Chih-Ching; Kao, Chih-Ming; Chen, De-Yu; Chen, Ssu Ching; Chen, Chien-Cheng

2014-05-01

The compound 2,4,6-trinitrotoluene (TNT) is a secondary explosive widely used worldwide for both military and civil purposes. As a result, residual TNT has been detected as an environmental pollutant in both soil and groundwater. The authors have isolated several microbial strains from soil contaminated with TNT by enrichment culture techniques using TNT as a carbon, nitrogen, and energy source. The contaminated soil contained approximately 1860 ppm TNT measured by high-performance liquid chromatography (HPLC). The initial identification of these isolates was determined by 16S rRNA gene comparison. The isolates mainly included species belonging to the genus Pseudomonas. Two strains (Pseudomonas putida strain TP1 and Pseudomonas aeruginosa strain TP6) were selected for further examination. Both strains demonstrated the ability to grow on the medium containing TNT as a carbon, energy, and nitrogen source and also clearly demonstrated the ability to degrade TNT. More than 90% of the TNT in the growth medium was degraded by both strains after 22 d incubation, as determined by HPLC. Additionally, the resting cells of P. putida TP1 and P. aeruginosa TP6 both significantly displayed the ability to transform (metabolize) TNT. © 2014 SETAC.

The microbiology of beef carcasses and primals during chilling and commercial storage.

PubMed

Reid, Rachael; Fanning, Séamus; Whyte, Paul; Kerry, Joe; Lindqvist, Roland; Yu, Zhongyi; Bolton, Declan

2017-02-01

The primary objective of this study was to characterise (microbiology and physical parameters) beef carcasses and primals during chilled storage. A minor aim was to compare observed growth of key spoilage bacteria on carcasses with that predicted by ComBase and the Food Safety Spoilage Predictor (FSSP). Total viable count (TVC), total Enterobacteriacae count (TEC), Pseudomonas spp., lactic acid bacteria (LAB), Brochothrix thermosphacta and Clostridium spp. were monitored on beef carcasses (n = 30) and primals (n = 105) during chilled storage using EC Decision 2001/471/EC and ISO sampling/laboratory procedures. The surface and/or core temperature, pH and water activity (a w ) were also recorded. Clostridium (1.89 log 10  cfu/cm 2 ) and Pseudomonas spp. (2.12 log 10  cfu/cm 2 ) were initially the most prevalent bacteria on carcasses and primals, respectively. The shortest mean generation time (G) was observed on carcasses with Br. thermosphacta (20.3 h) and on primals with LAB (G = 68.8 h) and Clostridium spp. (G = 67 h). Over the course of the experiment the surface temperature decreased from 37 °C to 0 °C, pH from 7.07 to 5.65 and a w from 0.97 to 0.93 The observed Pseudomonas spp. and Br. thermosphacta growth was more or less within the range of predictions of Combase. In contrast, the FSSP completely overestimated the growth of LAB. This study contributes to the very limited microbiological data on beef carcasses and primals during chilling. Copyright © 2016 Elsevier Ltd. All rights reserved.

Production of Cell-Cell Signaling Molecules by Bacteria Isolated From Human Chronic Wounds

PubMed Central

Rickard, Alexander H.; Colacino, Katelyn R.; Manton, Katelynn M.; Morton, Robert I.; Pulcini, Elinor; Pfeil, Joanne; Rhoads, Daniel; Wolcott, Randall D.; James, Garth

2009-01-01

AIM To (i) identify chronic wound bacteria and to test their ability to produce acyl-homoserine-lactones (AHLs) and autoinducer-2 (AI-2) cell-cell signaling molecules and (ii) determine if chronic wound debridement samples might contain these molecules. METHODS AND RESULTS Partial 16S rRNA gene sequencing revealed the identity of 46 chronic wound strains as belonging to nine genera. Using bio-reporter assays, 69.6% of the chronic wound strains were inferred to produce AI-2 while 19.6% were inferred to produced AHL molecules. At-least one strain from every genus, except those belonging to the genera Acinetobacter and Pseudomonas, were indicated to produce AI-2. Production of AI-2 in batch-cultures was growth-phase-dependent. Cross-feeding assays demonstrated that AHLs were produced by Acinetobacter spp., Pseudomonas aeruginosa and Serratia marcescens. Independent from studies of the bacterial species isolated from wounds, AHL and/or AI-2 signaling molecules were detected in 21 of 30 debridement samples of unknown microbial composition. CONCLUSION Chronic wound bacteria produce cell-cell signaling molecules. Resident species generally produce AI-2 molecules and aggressive transient species associated with chronic wounds typically produce AHLs. Both these classes of cell-cell signals are present in human chronic wounds. SIGNIFICANCE AND IMPACT OF STUDY Inter-bacterial cell-cell signaling may be an important factor influencing wound development and the presence of AHLs and AI-2 could be used as a predictor of wound severity. Manipulation of cell −cell signaling may provide a novel strategy for improving wound healing. PMID:19840177

Genome Sequences of Pseudomonas spp. Isolated from Cereal Crops

PubMed Central

Stiller, Jiri; Covarelli, Lorenzo; Lindeberg, Magdalen; Shivas, Roger G.; Manners, John M.

2013-01-01

Compared to those of dicot-infecting bacteria, the available genome sequences of bacteria that infect wheat and barley are limited. Herein, we report the draft genome sequences of four pseudomonads originally isolated from these cereals. These genome sequences provide a useful resource for comparative analyses within the genus and for cross-kingdom analyses of plant pathogenesis. PMID:23661484

Antibacterial activity of BMS-180680, a new catechol-containing monobactam.

PubMed Central

Fung-Tomc, J; Bush, K; Minassian, B; Kolek, B; Flamm, R; Gradelski, E; Bonner, D

1997-01-01

The in vitro activities of a new catechol-containing monobactam, BMS-180680 (SQ 84,100), were compared to those of aztreonam, ceftazidime, imipenem, piperacillin-tazobactam, ciprofloxacin, amikacin, and trimethoprim-sulfamethoxazole. BMS-180680 was often the most active compound against many species of the family Enterobacteriaceae, with MICs at which 90% of the isolates were inhibited (MIC90s) of < or = 0.5 microg/ml for Escherichia coli, Klebsiella spp., Citrobacter diversus, Enterobacter aerogenes, Serratia marcescens, Proteus spp., and Providencia spp. BMS-180680 had moderate activities (MIC90s of 2 to 8 microg/ml) against Citrobacter freundii, Morganella morganii, Shigella spp., and non-E. aerogenes Enterobacter spp. BMS-180680 was the only antibiotic evaluated that was active against >90% of the Pseudomonas aeruginosa (MIC90, 0.25 microg/ml), Burkholderia cepacia, and Stenotrophomonas maltophilia (MIC90s, 1 microg/ml) strains tested. BMS-180680 was inactive against most strains of Pseudomonas fluorescens, Pseudomonas stutzeri, Pseudomonas diminuta, and Burkholderia pickettii. BMS-180680 was moderately active (MIC90s of 4 to 8 microg/ml) against Alcaligenes spp. and Acinetobacter lwoffii and less active (MIC90, 16 microg/ml) against Acinetobacter calcoaceticus-Acinetobacter baumanii complex. BMS-180680 lacked activity against gram-positive bacteria and anaerobic bacteria. Both tonB and cir fiu double mutants of E. coli had greatly decreased susceptibility to BMS-180680. Of the TEM, PSE, and chromosomal-encoded beta-lactamases tested, only the K1 enzyme hydrolyzed BMS-180680 to any measurable extent. Like aztreonam, BMS-180680 bound preferentially to penicillin-binding protein 3. The MICs of BMS-180680 were not influenced by the presence of hematin or 5% sheep blood in the test medium or with incubation in an atmosphere containing 5% CO2. BMS-180680 MICs obtained under strict anaerobic conditions were significantly higher than those obtained in ambient air

Fast label-free detection of Legionella spp. in biofilms by applying immunomagnetic beads and Raman spectroscopy.

PubMed

Kusić, Dragana; Rösch, Petra; Popp, Jürgen

2016-03-01

Legionellae colonize biofilms, can form a biofilm by itself and multiply intracellularly within the protozoa commonly found in water distribution systems. Approximately half of the known species are pathogenic and have been connected to severe multisystem Legionnaires' disease. The detection methods for Legionella spp. in water samples are still based on cultivation, which is time consuming due to the slow growth of this bacterium. Here, we developed a cultivation-independent, label-free and fast detection method for legionellae in a biofilm matrix based on the Raman spectroscopic analysis of isolated single cells via immunomagnetic separation (IMS). A database comprising the Raman spectra of single bacterial cells captured and separated from the biofilms formed by each species was used to build the identification method based on a support vector machine (SVM) discriminative classifier. The complete method allows the detection of Legionella spp. in 100 min. Cross-reactivity of Legionella spp. specific immunomagnetic beads to the other studied genera was tested, where only small cell amounts of Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli compared to the initial number of cells were isolated by the immunobeads. Nevertheless, the Raman spectra collected from isolated non-targeted bacteria were well-discriminated from the Raman spectra collected from isolated Legionella cells, whereby the Raman spectra of the independent dataset of Legionella strains were assigned with an accuracy of 98.6%. In addition, Raman spectroscopy was also used to differentiate between isolated Legionella species. Copyright © 2016 Elsevier GmbH. All rights reserved.

The effect of different gas permeability of packaging on physicochemical and microbiological parameters of pork loin storage under high O2 modified atmosphere packaging conditions.

PubMed

Marcinkowska-Lesiak, Monika; Poławska, Ewa; Wierzbicka, Agnieszka

2017-03-01

The aim of this study was to determine the influence of different packaging materials on meat quality during cold storage. Therefore pork loins (m. longissimus thoracis et lumborum) obtained from crossbred pigs (Polish Landrance x Duroc, n = 6) were stored at 2 ℃ in modified atmosphere packs (80% O 2 , 20% CO 2 ) in four types of trays, which differ in gas permeability. Physicochemical (headspace gas composition, pH, colour, drip loss, cooking loss, shear force, the basic composition and fatty acid profile) and microbiological ( Salmonella spp., Escherichia coli, Enterobacteriaceae, total aerobic plates count, total psychrotrophic bacteria count, the number of lactic acid bacteria, Pseudomonas spp., the general amount of yeast and mold) parameters were monitored for up to 12 days. At the end of the storage period no differences in most physicochemical properties of pork loin due to type of packaging were found, however trays with high gas permeability had the greatest impact on total aerobic plates count and Pseudomonas spp. growth.

New strategies for genetic engineering Pseudomonas syringae using recombination

USDA-ARS?s Scientific Manuscript database

Here we report that DNA oligonucleotides (oligos) introduced directly into bacteria by electroporation can recombine with the bacterial chromosome. This phenomenon was identified in Pseudomonas syringae and we subsequently found that Escherichia coli, Salmonella typhimurium and Shigella flexneri are...

Mass spectrometry identification of alkyl-substituted pyrazines produced by Pseudomonas spp. isolates obtained from wine corks.

PubMed

Bañeras, Lluís; Trias, Rosalia; Godayol, Anna; Cerdán, Laura; Nawrath, Thorben; Schulz, Stefan; Anticó, Enriqueta

2013-06-15

We investigated the pyrazine production of 23 Pseudomonas isolates obtained from cork in order to assess their implications in off-flavour development. Off-flavour development in cork stoppers is a crucial process in maintaining the high quality of some wines. Pyrazine production was analyzed by headspace solid-phase-microextraction (HS-SPME) and gas chromatography coupled with mass spectrometry (GC-MS). Five out of the 23 isolates, i.e. Pseudomonas koreensis TCA20, Pseudomonas palleroniana TCA16, Pseudomonas putida TCA23 and N7, and Pseudomonas stutzeri TRA27a were able to produce branched alkyl-substituted pyrazines. For isolates N7 and TCA16, 14 compounds could be identified as pyrazines. The use of mineral media supplemented with different carbon and nitrogen sources resulted in changes in the pyrazine production capacity. In the two strains the amount of pyrazines produced was higher with glucose and decreased significantly with lactate. In all cases, 2,5-di(1-methylethyl)pyrazine was found to be dominant and independent of amino acid addition, suggesting a completely de novo synthesis. Aroma descriptions of most alkyl substituted pyrazines include mild vegetal aromas, not necessarily undesirable for the cork manufacturing industry. Methoxypyrazines, exhibiting earthy and musty aromas, could not be detected in any of the strains analysed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Role of the Pseudomonas quinolone signal (PQS) in sensitising Pseudomonas aeruginosa to UVA radiation.

PubMed

Pezzoni, Magdalena; Meichtry, Martín; Pizarro, Ramón A; Costa, Cristina S

2015-01-01

One of the main stress factors that bacteria face in the environment is solar ultraviolet-A (UVA) radiation, which leads to lethal effects through oxidative damage. The aim of this work was to investigate the role of 2-heptyl-3-hydroxi-4-quinolone (the Pseudomonas quinolone signal or PQS) in the response of Pseudomonas aeruginosa to UVA radiation. PQS is an intercellular quorum sensing signal associated to membrane vesicles which, among other functions, regulates genes related to iron acquisition, forms stable complexes with iron and participates in oxidative phenomena. UVA exposure of the wild-type PAO1 strain and a pqsA mutant unable to produce PQS revealed a sensitising role for this signal. Research into the mechanism involved in this phenomenon revealed that catalase, an essential factor in the UVA defence, is not related to PQS-mediated UVA sensitivity. Absorption of UVA by PQS produced its own photo-degradation, oxidation of the probe 2',7'- dichlorodihydrofluorescein and generation of singlet oxygen and superoxide anion, suggesting that this signal could be acting as an endogenous photosensitiser. The results presented in this study could explain the high sensitivity to UVA of P. aeruginosa when compared to enteric bacteria. Copyright © 2014 Elsevier B.V. All rights reserved.

The effect of zinc limitation on the transcriptome of Pseudomonas fluorescens Pf-5

USDA-ARS?s Scientific Manuscript database

Pseudomonas fluorescens Pf-5 is a soil bacterium that can protect several plant species from diseases caused by fungal and bacterial pathogens. Zinc is a vital micronutrient for bacteria but is deficient in some soil environments and toxic in large quantities. Hence, bacteria have evolved elaborate ...

Distribution and identification of proteolytic Bacillus spp. in paddy field soil under rice cultivation.

PubMed

Watanabe, K; Hayano, K

1993-07-01

Proteolytic bacteria in paddy field soils under rice cultivation were characterized and enumerated using azocoll agar plates. Bacillus spp. were the proteolytic bacteria that were most frequently present, comprising 59% of the isolates. They were always the numerically dominant proteolytic bacteria isolated from three kinds of fertilizer treatments (yearly application of rice-straw compost and chemical fertilizer, yearly application of chemical fertilizer, and no fertilizer application) and at three different stages of rice development (vegetative growth stage, maximal tillering stage, and harvest stage). Of the 411 proteolytic bacteria isolated, 124 isolates had stronger proteolytic activity than others on the basis of gelatin liquefaction tests and most of them were Bacillus spp. (100% in 1989 and 92.4% in 1991). Bacillus subtilis and Bacillus cereus were the main bacteria of this group and Bacillus mycoides, Bacillus licheniformis, and Bacillus megaterium were also present. We conclude that these Bacillus spp. are the primary source of soil protease in these paddy fields.

Detection of Ehrlichia spp., Anaplasma spp., Rickettsia spp., and other eubacteria in ticks from the Thai-Myanmar border and Vietnam.

PubMed

Parola, Philippe; Cornet, Jean-Paul; Sanogo, Yibayiri Osée; Miller, R Scott; Thien, Huynh Van; Gonzalez, Jean-Paul; Raoult, Didier; Telford III, Sam R; Wongsrichanalai, Chansuda

2003-04-01

A total of 650 ticks, including 13 species from five genera, were collected from animals, from people, or by flagging of the vegetation at sites on the Thai-Myanmar border and in Vietnam. They were tested by PCR to detect DNA of bacteria of the order RICKETTSIALES: Three Anaplasma spp. were detected in ticks collected in Thailand, including (i) Anaplasma sp. strain AnDa465, which was considered a genotype of Anaplasma platys (formerly Ehrlichia platys) and which was obtained from Dermacentor auratus ticks collected from dogs; (ii) Anaplasma sp. strain AnAj360, which was obtained from Amblyomma javanense ticks collected on a pangolin; and (iii) Anaplasma sp. strain AnHl446, which was closely related to Anaplasma bovis and which was detected in Haemaphysalis lagrangei ticks collected from a bear. Three Ehrlichia spp. were identified, including (i) Ehrlichia sp. strain EBm52, which was obtained from Boophilus microplus ticks collected from cattle from Thailand; (ii) Ehrlichia sp. strain EHh324, which was closely related to Ehrlichia chaffeensis and which was detected in Haemaphysalis hystricis ticks collected from wild pigs in Vietnam; and (iii) Ehrlichia sp. strain EHh317, which was closely related to Ehrlichia sp. strain EBm52 and which was also detected in H. hystricis ticks collected from wild pigs in Vietnam. Two Rickettsia spp. were detected in Thailand, including (i) Rickettsia sp. strain RDla420, which was detected in Dermacentor auratus ticks collected from a bear, and (ii) Rickettsia sp. strain RDla440, which was identified from two pools of Dermacentor larvae collected from a wild pig nest. Finally, two bacteria named Eubacterium sp. strain Hw124 and Eubacterium sp. strain Hw191 were identified in Haemaphysalis wellingtoni ticks collected from chicken in Thailand; these strains could belong to a new group of bacteria.

Detection of Ehrlichia spp., Anaplasma spp., Rickettsia spp., and Other Eubacteria in Ticks from the Thai-Myanmar Border and Vietnam

PubMed Central

Parola, Philippe; Cornet, Jean-Paul; Sanogo, Yibayiri Osée; Miller, R. Scott; Thien, Huynh Van; Gonzalez, Jean-Paul; Raoult, Didier; Telford III, Sam R.; Wongsrichanalai, Chansuda

2003-01-01

A total of 650 ticks, including 13 species from five genera, were collected from animals, from people, or by flagging of the vegetation at sites on the Thai-Myanmar border and in Vietnam. They were tested by PCR to detect DNA of bacteria of the order Rickettsiales. Three Anaplasma spp. were detected in ticks collected in Thailand, including (i) Anaplasma sp. strain AnDa465, which was considered a genotype of Anaplasma platys (formerly Ehrlichia platys) and which was obtained from Dermacentor auratus ticks collected from dogs; (ii) Anaplasma sp. strain AnAj360, which was obtained from Amblyomma javanense ticks collected on a pangolin; and (iii) Anaplasma sp. strain AnHl446, which was closely related to Anaplasma bovis and which was detected in Haemaphysalis lagrangei ticks collected from a bear. Three Ehrlichia spp. were identified, including (i) Ehrlichia sp. strain EBm52, which was obtained from Boophilus microplus ticks collected from cattle from Thailand; (ii) Ehrlichia sp. strain EHh324, which was closely related to Ehrlichia chaffeensis and which was detected in Haemaphysalis hystricis ticks collected from wild pigs in Vietnam; and (iii) Ehrlichia sp. strain EHh317, which was closely related to Ehrlichia sp. strain EBm52 and which was also detected in H. hystricis ticks collected from wild pigs in Vietnam. Two Rickettsia spp. were detected in Thailand, including (i) Rickettsia sp. strain RDla420, which was detected in Dermacentor auratus ticks collected from a bear, and (ii) Rickettsia sp. strain RDla440, which was identified from two pools of Dermacentor larvae collected from a wild pig nest. Finally, two bacteria named Eubacterium sp. strain Hw124 and Eubacterium sp. strain Hw191 were identified in Haemaphysalis wellingtoni ticks collected from chicken in Thailand; these strains could belong to a new group of bacteria. PMID:12682151

The antibacterial activity of compounds isolated from oakmoss against Legionella pneumophila and other Legionella spp.

PubMed

Nomura, Harue; Isshiki, Yasunori; Sakuda, Keisuke; Sakuma, Katsuya; Kondo, Seiichi

2012-01-01

Oakmoss is a natural fragrance ingredient exhibiting highly specific, potent antibacterial activity against Legionella pneumophila, a causative agent of severe water-bone pneumonia. In the present study, the antibacterial activity of individual compounds isolated from oakmoss was investigated against L. pneumophila and other Legionella spp. A total of 18 known compounds and two minor novel compounds (i.e., 3-methoxy-5-methylphenyl-2,4-dihydroxy-6-methylbenzoate (compound 9) and 8-(2,4-dihydroxy-6-(2-oxoheptyl)-phenoxy)-6-hydroxy-3-pentyl-1H-isochromen-1-one (compound 20)) were purified from oakmoss. The minimum inhibitory concentrations (MICs) against clinical and environmental isolates of L. pneumophila, L. bozemanii, L. micdadei, L. longbeachae, and L. dumoffii for 11 of the 20 compounds were less than 100 µg/mL (range 0.8-64.0 µg/mL). Novel compounds 9 and 20 exhibited potent antibacterial activity against L. pneumophila strains (MIC ranges of 1.3-8.0 µg/mL and 3.3-13.3 µg/mL, respectively) and also against four other Legionella species (MIC ranges of 0.8-8.0 µg/mL and 3.3-21.3 µg/mL, respectively). Time-kill assays indicated that compounds 9 and 20 kill bacteria at a concentration equivalent to 2×MIC after 1 h and 6 h co-incubations, respectively. While oakmoss and the purified components exhibited antibacterial activity against Legionella spp., they were not active against other Gram-negative and -positive bacteria such as Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus.

Optimization of Cellulase Production from Bacteria Isolated from Soil

PubMed Central

Sethi, Sonia; Datta, Aparna; Gupta, B. Lal; Gupta, Saksham

2013-01-01

Cellulase-producing bacteria were isolated from soil and identified as Pseudomonas fluorescens, Bacillus subtilIs, E. coli, and Serratia marcescens. Optimization of the fermentation medium for maximum cellulase production was carried out. The culture conditions like pH, temperature, carbon sources, and nitrogen sources were optimized. The optimum conditions found for cellulase production were 40°C at pH 10 with glucose as carbon source and ammonium sulphate as nitrogen source, and coconut cake stimulates the production of cellulase. Among bacteria, Pseudomonas fluorescens is the best cellulase producer among the four followed by Bacillus subtilis, E. coli, and Serratia marscens. PMID:25937986

Distinguishing potential bacteria-tumor associations from contamination in a secondary data analysis of public cancer genome sequence data.

PubMed

Robinson, Kelly M; Crabtree, Jonathan; Mattick, John S A; Anderson, Kathleen E; Dunning Hotopp, Julie C

2017-01-25

A variety of bacteria are known to influence carcinogenesis. Therefore, we sought to investigate if publicly available whole genome and whole transcriptome sequencing data generated by large public cancer genome efforts, like The Cancer Genome Atlas (TCGA), could be used to identify bacteria associated with cancer. The Burrows-Wheeler aligner (BWA) was used to align a subset of Illumina paired-end sequencing data from TCGA to the human reference genome and all complete bacterial genomes in the RefSeq database in an effort to identify bacterial read pairs from the microbiome. Through careful consideration of all of the bacterial taxa present in the cancer types investigated, their relative abundance, and batch effects, we were able to identify some read pairs from certain taxa as likely resulting from contamination. In particular, the presence of Mycobacterium tuberculosis complex in the ovarian serous cystadenocarcinoma (OV) and glioblastoma multiforme (GBM) samples was correlated with the sequencing center of the samples. Additionally, there was a correlation between the presence of Ralstonia spp. and two specific plates of acute myeloid leukemia (AML) samples. At the end, associations remained between Pseudomonas-like and Acinetobacter-like read pairs in AML, and Pseudomonas-like read pairs in stomach adenocarcinoma (STAD) that could not be explained through batch effects or systematic contamination as seen in other samples. This approach suggests that it is possible to identify bacteria that may be present in human tumor samples from public genome sequencing data that can be examined further experimentally. More weight should be given to this approach in the future when bacterial associations with diseases are suspected.

AlgU controls expression of virulence genes in Pseudomonas syringae pv. tomato DC3000

USDA-ARS?s Scientific Manuscript database

Plant pathogenic bacteria are able to integrate information about their environment and adjust gene expression to provide adaptive functions. AlgU, an ECF sigma factor encoded by Pseudomonas syringae, controls expression of genes for alginate biosynthesis and is active while the bacteria are associa...

Antibiotic Resistance of Bacteria Isolated from the Internal Organs of Edible Snow Crabs

PubMed Central

Kim, Misoon; Kwon, Tae-Hyung; Jung, Su-Mi; Cho, Seung-Hak; Jin, Seon Yeong; Park, Nyun-Ho; Kim, Choong-Gon; Kim, Jong-Shik

2013-01-01

Antibiotic resistance and microbiota within edible snow crabs are important for the Chionoecetes (snow crab) fishing industry. We investigated these parameters using culture methods and antibiotic susceptibility tests with six internal organs from three species of Chionoecetes. Each sample revealed many unexpected microbial species within Chionoecetes internal organs. On the basis of 16S rRNA sequence analysis of 381 isolates, the most abundant genera identified in Chionoecetes opilio were Acinetobacter spp. (24%), Bacillus spp. (4%), Pseudomonas spp. (34%), Stenotrophomonas spp. (28%), and Agreia spp. (11%). In Chionoecetes sp. crabs, Acinetobacter spp. (23%), Bacillus spp. (12%), and Psychrobacter spp. (20%) were most prevalent, while Agreia spp. (11%), Bacillus spp. (31%), Microbacterium spp. (10%), Rhodococcus spp. (12%), and Agrococcus spp. (6%) were most abundant in C. japonicus. Our antibiotic resistance test found resistance to all nine antibiotics tested in 19, 14, and two of the isolates from C. opilio, Chionoecetes sp., and, C. japonicus respectively. Our results are the first to show that microbes with antibiotic resistance are widely distributed throughout the internal organs of natural snow crabs. PMID:23990916

Exchange of Xcp (Gsp) secretion machineries between Pseudomonas aeruginosa and Pseudomonas alcaligenes: species specificity unrelated to substrate recognition.

PubMed

de Groot, A; Koster, M; Gérard-Vincent, M; Gerritse, G; Lazdunski, A; Tommassen, J; Filloux, A

2001-02-01

Pseudomonas aeruginosa and Pseudomonas alcaligenes are gram-negative bacteria that secrete proteins using the type II or general secretory pathway, which requires at least 12 xcp gene products (XcpA and XcpP to -Z). Despite strong conservation of this secretion pathway, gram-negative bacteria usually cannot secrete exoproteins from other species. Based on results obtained with Erwinia, it has been proposed that the XcpP and/or XcpQ homologs determine this secretion specificity (M. Linderberg, G. P. Salmond, and A. Collmer, Mol. Microbiol. 20:175-190, 1996). In the present study, we report that XcpP and XcpQ of P. alcaligenes could not substitute for their respective P. aeruginosa counterparts. However, these complementation failures could not be correlated to species-specific recognition of exoproteins, since these bacteria could secrete exoproteins of each other. Moreover, when P. alcaligenes xcpP and xcpQ were expressed simultaneously in a P. aeruginosa xcpPQ deletion mutant, complementation was observed, albeit only on agar plates and not in liquid cultures. After growth in liquid culture the heat-stable P. alcaligenes XcpQ multimers were not detected, whereas monomers were clearly visible. Together, our results indicate that the assembly of a functional Xcp machinery requires species-specific interactions between XcpP and XcpQ and between XcpP or XcpQ and another, as yet uncharacterized component(s).

Comparative Study of Hydroalcoholic Extracts of Momordica charantia L. against Foodborne Pathogens

PubMed Central

Rakholiya, Kalpna; Vaghela, P.; Rathod, T.; Chanda, Sumitra

2014-01-01

The antimicrobial effect of 24 different hydroalcoholic extracts (100, 75, 50 and 25% methanol and water) obtained from four parts (leaf+stem (aerial), peel, pulp and seed) of Momordica charantia L. were investigated against five Gram-positive, six Gram-negative and four fungal strains. The extraction was done by individual cold percolation method using hexane, different hydroalcoholic solvent (100, 75, 50 and 25% methanol) and water. The antimicrobial activity was done by agar well diffusion assay. The extracts, which showed >15 mm zone of inhibition, were further screened to determine minimum inhibitory concentration and minimum bactericidal concentration using a broth dilution method performed in 96-well microtitre plate. The extractive yield was highest in aqueous extracts of all the four parts closely followed by 25% methanol. Micrococcus flavus was the most susceptible Gram-positive bacteria and Pseudomonas testosteroni was the most susceptible Gram-negative bacteria. The highest antibacterial activity was shown by 100% methanol. The Gram-negative Pseudomonas spp. was more susceptible towards all the extracts than the Gram-positive bacteria or fungal strains investigated. One hundred percent and 50% methanol extracts of seed showed lowest minimum inhibitory concentration and minimum bactericidal concentration values, that is <39 and 625 μg/ml, respectively, against Pseudomonas pictorum. Therefore, these extracts would be of interest in the control of Pseudomonas spp. in food industry as well as used for therapeutic purposes. PMID:24843188

[The importance of wildlife as reservoir of antibiotic-resistant bacteria in Bavaria--first results].

PubMed

Meyer, Cornelia; Heurich, Marco; Huber, Ingrid; Krause, Gladys; Ullrich, Ulrike; Fetsch, Alexandra

2014-01-01

The use of antimicrobial agents is responsible for the emergence and spread of antibiotic resistant bacteria. Nevertheless, multiresistant bacteria have been found in animals that have never been exposed to antimicrobial agents. Wild animals that are carriers of methicillin-resistant organisms represent a hazard since they can transmit their bacteria to other animals and to humans. In the hunting season 2009/2010 nasal swabs of 98 red deer and 109 wild boars were examined for the presence of methicillin-sensitive and methicillin-resistant staphylococci. From each wild boar methicillin-susceptible staphylococci (Staphylococcus aureus in 28% and Staphylococcus spp. in 72% of the animals) were isolated. In red deer the detection rate of Staphylococcus (S.) aureus and methicillin-susceptible staphylococci was 49% and 17%, respectively. The occurrence of S. aureus was significantly higher (p < 0.05) in red deer than in wild boars. Methicillin-resistant staphylococci were not found. However, in one third of the red deer, methicillin-resistant bacteria of the genus Enterococcus spp. and Bacillus spp. were isolated. The results of the present study indicate that wildlife, especially red deer are an important reservoir for S. aureus and that the upper respiratory tract of red deer is regularly colonised with methicillin-resistant bacteria such as Bacillus spp. and Enterococcus spp. Primarily, commensal bacteria are harmless to human health, however, red deer may be a reservoir for antibiotic-resistant bacteria.

Divergent pro-inflammatory profile of human dendritic cells in response to commensal and pathogenic bacteria associated with the airway microbiota.

PubMed

Larsen, Jeppe Madura; Steen-Jensen, Daniel Bisgaard; Laursen, Janne Marie; Søndergaard, Jonas Nørskov; Musavian, Hanieh Sadat; Butt, Tariq Mahmood; Brix, Susanne

2012-01-01

Recent studies using culture-independent methods have characterized the human airway microbiota and report microbial communities distinct from other body sites. Changes in these airway bacterial communities appear to be associated with inflammatory lung disease, yet the pro-inflammatory properties of individual bacterial species are unknown. In this study, we compared the immune stimulatory capacity on human monocyte-derived dendritic cells (DCs) of selected airway commensal and pathogenic bacteria predominantly associated with lungs of asthma or COPD patients (pathogenic Haemophillus spp. and Moraxella spp.), healthy lungs (commensal Prevotella spp.) or both (commensal Veillonella spp. and Actinomyces spp.). All bacteria were found to induce activation of DCs as demonstrated by similar induction of CD83, CD40 and CD86 surface expression. However, asthma and COPD-associated pathogenic bacteria provoked a 3-5 fold higher production of IL-23, IL-12p70 and IL-10 cytokines compared to the commensal bacteria. Based on the differential cytokine production profiles, the studied airway bacteria could be segregated into three groups (Haemophilus spp. and Moraxella spp. vs. Prevotella spp. and Veillonella spp. vs. Actinomyces spp.) reflecting their pro-inflammatory effects on DCs. Co-culture experiments found that Prevotella spp. were able to reduce Haemophillus influenzae-induced IL-12p70 in DCs, whereas no effect was observed on IL-23 and IL-10 production. This study demonstrates intrinsic differences in DC stimulating properties of bacteria associated with the airway microbiota.

Divergent Pro-Inflammatory Profile of Human Dendritic Cells in Response to Commensal and Pathogenic Bacteria Associated with the Airway Microbiota

PubMed Central

Larsen, Jeppe Madura; Steen-Jensen, Daniel Bisgaard; Laursen, Janne Marie; Søndergaard, Jonas Nørskov; Musavian, Hanieh Sadat; Butt, Tariq Mahmood; Brix, Susanne

2012-01-01

Recent studies using culture-independent methods have characterized the human airway microbiota and report microbial communities distinct from other body sites. Changes in these airway bacterial communities appear to be associated with inflammatory lung disease, yet the pro-inflammatory properties of individual bacterial species are unknown. In this study, we compared the immune stimulatory capacity on human monocyte-derived dendritic cells (DCs) of selected airway commensal and pathogenic bacteria predominantly associated with lungs of asthma or COPD patients (pathogenic Haemophillus spp. and Moraxella spp.), healthy lungs (commensal Prevotella spp.) or both (commensal Veillonella spp. and Actinomyces spp.). All bacteria were found to induce activation of DCs as demonstrated by similar induction of CD83, CD40 and CD86 surface expression. However, asthma and COPD-associated pathogenic bacteria provoked a 3–5 fold higher production of IL-23, IL-12p70 and IL-10 cytokines compared to the commensal bacteria. Based on the differential cytokine production profiles, the studied airway bacteria could be segregated into three groups (Haemophilus spp. and Moraxella spp. vs. Prevotella spp. and Veillonella spp. vs. Actinomyces spp.) reflecting their pro-inflammatory effects on DCs. Co-culture experiments found that Prevotella spp. were able to reduce Haemophillus influenzae-induced IL-12p70 in DCs, whereas no effect was observed on IL-23 and IL-10 production. This study demonstrates intrinsic differences in DC stimulating properties of bacteria associated with the airway microbiota. PMID:22363778

CrcZ and CrcX regulate carbon utilization in Pseudomonas syringae pathovar tomato strain DC3000

USDA-ARS?s Scientific Manuscript database

Small non-coding RNAs (ncRNAs) are important components of many regulatory pathways in bacteria and play key roles in regulating factors important for virulence. Carbon catabolite repression control is modulated by small RNAs (crcZ or crcZ and crcY) in Pseudomonas aeruginosa and Pseudomonas putida. ...

Etiology and Antimicrobial Susceptibility Pattern of Pathogenic Bacteria in Children Subjected to UTI: A Referral Hospital-Based Study in Northwest of Iran.

PubMed

Rezaee, Mohammad Ahangarzadeh; Abdinia, Babak

2015-09-01

Urinary tract infection (UTI) is 1 of the most common bacterial diseases in children with a considerable resistance to antimicrobials. This 5 years prospective study was carried out to determine the frequency of isolation and antimicrobial resistance patterns of uropathogens among children subjected to urine culture at Tabriz Children Educational-Health Care Center, in the northwest of Iran. Organisms were isolated using standard culture techniques. Frequency of UTI among children examined by urine culture was 3.6%. The isolated bacteria were Escherichia coli (71.4%), followed by Klebsiella spp. (9.6%), Enterococcus spp. (6.4%), Pseudomonas aeruginosa (4.2%), Serratia spp. (4.2%), and Enterobacter spp. (4.2%). E coli resistance levels were 11% for nitrofurantoin, 15% for ciprofloxacin, 25% for nalidixic acid, and 30% to 75% for amikacin, gentamicin, ceftriaxone, ceftizoxime, cefotaxime, and co-trimoxazole. Among the tested antibiotics, ciprofloxacin, showed the highest activity (100%) against Klebsiella and P aeruginosa isolates followed by amikacin, nalidixic acid, and gentamicin. Overall, the highly active antibiotic against Gram-negative and Gram-positive organisms was amikacin and then ciprofloxacin. On the other hand, the empirical initial therapy with co-trimoxazole and third-generation cephalosporins would be inadequate for more cases of UTI in the study area. Moreover, susceptibility testing should be carried out on all clinical isolates, and the empirical antibiotic treatment changed accordingly.

Hydrogel Dressing with a Nano-Formula against Methicillin-Resistant Staphylococcus aureus and Pseudomonas aeruginosa Diabetic Foot Bacteria.

PubMed

El-Naggar, Moustafa Y; Gohar, Yousry M; Sorour, Magdy A; Waheeb, Marian G

2016-02-01

This study proposes an alternative approach for the use of chitosan silver-based dressing for the control of foot infection with multidrug-resistant bacteria. Sixty-five bacterial isolates were isolated from 40 diabetic patients. Staphylococcus aureus (37%) and Pseudomonas aeruginosa (18.5%) were the predominant isolates in the ulcer samples. Ten antibiotics were in vitro tested against diabetic foot clinical bacterial isolates. The most resistant S. aureus and P. aeruginosa isolates were then selected for further study. Three chitosan sources were tested individually for chelating silver nanoparticles. Squilla chitosan silver nanoparticles (Sq. Cs-Ag(0)) showed the maximum activity against the resistant bacteria when mixed with amikacin that showed the maximum synergetic index. This, in turn, resulted in the reduction of the amikacin MIC value by 95%. For evaluation of the effectiveness of the prepared dressing using Artemia salina as the toxicity biomarker, the LC50 was found to be 549.5, 18,000, and 10,000 μg/ml for amikacin, Sq. Cs-Ag(0), and dressing matrix, respectively. Loading the formula onto chitosan hydrogel dressing showed promising antibacterial activities, with responsive healing properties for the wounds in normal rats of those diabetic rats (polymicrobial infection). It is quite interesting to note that no emergence of any side effect on either kidney or liver biomedical functions was noticed.

Microbiology and management of joint and bone infections due to anaerobic bacteria.

PubMed

Brook, Itzhak

2008-03-01

To describes the microbiology, diagnosis, and management of septic arthritis and osteomyelitis due to anaerobic bacteria. The predominant anaerobes in arthritis are anaerobic Gram-negative bacilli (AGNB) including the Bacteroides fragilis group, Fusobacterium spp., Peptostreptococcus spp., and Propionibacterium acnes. Infection with P. acnes is associated with a prosthetic joint, previous surgery, and trauma. B. fragilis group is associated with distant infection, Clostridium spp. with trauma, and Fusobacterium spp. with oropharyngeal infection. Most cases of anaerobic arthritis, in contrast to anaerobic osteomyelitis, involved a single isolate, and most cases are secondary to hematogenous spread. The predominant anaerobes in osteomyelitis are Bacteroides, Peptostreptococcus, Fusobacterium, and Clostridium spp. as well as P. acnes. Conditions predisposing to bone infections are vascular disease, bites, contiguous infection, peripheral neuropathy, hematogenous spread, and trauma. Pigmented Prevotella and Porphyromonas spp. are mostly isolated in skull and bite infections, members of the B. fragilis group in hand and feet infections, and Fusobacterium spp. in skull, bite, and hematogenous long bone infections. Many patients with osteomyelitis due to anaerobic bacteria have evidence of an anaerobic infection elsewhere in the body that is the source of the organisms involved in the osteomyelitis. Treatment of arthritis and osteomyelitis involving anaerobic bacteria includes symptomatic therapy, immobilization in some cases, adequate drainage of purulent material, and antibiotic therapy effective against these organisms. Anaerobic bacteria can cause septic arthritis and osteomyelitis. Correct diagnosis and appropriate therapy are important contributor to successful outcome.

Evaluation of an antibiotic producing strain of Pseudomonas flourescens for suppression of plant-parasitic nematodes

USDA-ARS?s Scientific Manuscript database

The antibiotic 2,4-diacetylphloroglucinol (DAPG), produced by some strains of Pseudomonas spp., is involved in suppression of several fungal root pathogens as well as plant-parasitic nematodes. The primary objective of this study was to determine whether Wood1R, a D-genotype strain of DAPG-producin...

Quorum Sensing Signaling Molecules Produced by Reference and Emerging Soft-Rot Bacteria (Dickeya and Pectobacterium spp.)

PubMed Central

Crépin, Alexandre; Barbey, Corinne; Beury-Cirou, Amélie; Hélias, Valérie; Taupin, Laure; Reverchon, Sylvie; Nasser, William; Faure, Denis; Dufour, Alain; Orange, Nicole; Feuilloley, Marc; Heurlier, Karin; Burini, Jean-François; Latour, Xavier

2012-01-01

Background Several small diffusible molecules are involved in bacterial quorum sensing and virulence. The production of autoinducers-1 and -2, quinolone, indole and γ-amino butyrate signaling molecules was investigated in a set of soft-rot bacteria belonging to six Dickeya or Pectobacterium species including recent or emerging potato isolates. Methodology/Principal Findings Using bacterial biosensors, immunoassay, and chromatographic analysis, we showed that soft-rot bacteria have the common ability to produce transiently during their exponential phase of growth the N-3-oxo-hexanoyl- or the N-3-oxo-octanoyl-l-homoserine lactones and a molecule of the autoinducer-2 family. Dickeya spp. produced in addition the indole-3-acetic acid in tryptophan-rich conditions. All these signaling molecules have been identified for the first time in the novel Dickeya solani species. In contrast, quinolone and γ-amino butyrate signals were not identified and the corresponding synthases are not present in the available genomes of soft-rot bacteria. To determine if the variations of signal production according to growth phase could result from expression modifications of the corresponding synthase gene, the respective mRNA levels were estimated by reverse transcriptase-PCR. While the N-acyl-homoserine lactone production is systematically correlated to the synthase expression, that of the autoinducer-2 follows the expression of an enzyme upstream in the activated methyl cycle and providing its precursor, rather than the expression of its own synthase. Conclusions/Significance Despite sharing the S-adenosylmethionine precursor, no strong link was detected between the production kinetics or metabolic pathways of autoinducers-1 and -2. In contrast, the signaling pathway of autoinducer-2 seems to be switched off by the indole-3-acetic acid pathway under tryptophan control. It therefore appears that the two genera of soft-rot bacteria have similarities but also differences in the

An analysis of wilderness water in Kings Canyon, Sequoia, and Yosemite national parks for coliform and pathologic bacteria.

PubMed

Derlet, Robert W; Carlson, James R

2004-01-01

To determine the prevalence of coliform and potentially pathogenic bacteria in remote backcountry alpine lakes and streams of national parks in the Sierra Nevada mountains. Water was sampled at 55 predetermined lakes and streams that would stratify the risk, based on sites used by backpackers, sites used by pack animals, and uncontaminated wild areas. Sites were distributed among Kings Canyon (15), Sequoia (17), and Yosemite (23). Water was collected using Millipore bacterial samplers, which provided specific counts of coliform and other bacteria in each water sample and also served as a transport media from the wilderness to the laboratory. On return to the laboratory, bacteria were harvested from the samplers and subjected to specific identification and qualitative analysis using standard microbiology techniques for the analysis of water. Coliform bacteria were detected in 22 of the 55 sites. All of these sites were below areas used by backpackers or pack animals. Thirty-three sites were free of coliforms. These sites included both those used lightly by backpackers and those with no human or domestic animal use. All samples contained expected amounts of normal aquatic bacteria including Pseudomonas, Rahnella aquatilis, Serratia spp, and nonpathogenic species of Yersinia. Most sampling sites in these national parks are free of coliform or pathogenic organisms. Low levels of coliform bacteria are found in some bodies of water where the watershed has been affected by human or pack animal travel.

Heterotrophic bacteria associated with the degradation of zooplankton fecal pellets in Lake Michigan. [Mysis relicta, pseudomonas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferrante, J.G.; Ptak, D.J.

1978-01-01

Heterotrophic microbes decompose most of the calanoid copepod fecal pellets produced in Lake Michigan before they reach the sediment. Rod-shaped nonfermenters isolated from copepod and Mysis relicta fecal pellets were identified as Pseudomonas maltophilia and Pseudomonas fluorescens species. No enterobacteriaceae or fungal hyphae were found on or in any pellets. This investigation suggests that Pseudomonas species are attached to and may degrade Mysis relicta and calanoid copepod fecal pellets in the water column of Lake Michigan.

ATMOSPHERIC NITROGEN FIXATION BY METHANE-OXIDIZING BACTERIA

PubMed Central

Davis, J. B.; Coty, V. F.; Stanley, J. P.

1964-01-01

Davis, J. B. (Socony Mobil Oil Co., Inc., Dallas, Tex.), V. F. Coty, and J. P. Stanley. Atmospheric nitrogen fixation by methane-oxidizing bacteria. J. Bacteriol. 88:468–472. 1964.—Methane-oxidizing bacteria capable of fixing atmospheric nitrogen were isolated from garden soil, pond mud, oil field soil, and soil exposed to natural gas, indicating a rather wide prevalence in nature. This may explain the high concentration of organic nitrogen commonly found in soils exposed to gas leakage from pipelines or natural-gas seeps. Added molybdenum was a requirement for growth in a nitrogen-free mineral salts medium. All nitrogen-fixing, methane-oxidizing bacteria isolated were gram-negative, nonsporeforming, usually motile rods. Colonies were light yellow, yellow, or white. The most common isolate, which formed light-yellow colonies, is referred to as Pseudomonas methanitrificans sp. n., and is distinguished from Pseudomonas (Methanomonas) methanica by nitrogen-fixing ability and a preponderance of poly-β-hydroxybutyrate in the cellular lipid fraction. Images PMID:14203365

[Isolation, identification and characterization of ACC deaminase-containing endophytic bacteria from halophyte Suaeda salsa].

PubMed

Teng, Songshan; Liu, Yanping; Zhao, Lei

2010-11-01

We Isolated and characterized 1-aminocyclopropane-1-carboxylate (ACC) deaminase-containing endophytic bacteria from halophyte Suaeda salsa to understand the interactions between endophytes and halophyte. ACC deaminase-containing endophytic bacteria were isolated from root, stalk and leaf of Suaeda salsa and were identified based on morphological, physiological-biochemical properties, API and 16S rRNA sequence analysis. Isolates were evaluated for their ACC deaminase, antifungal, protease activity, siderophores and phytohormones, such as indole-3-acetic acid, gibberellic acid and abscisic acid production, as well as atmospheric nitrogen fixation and phosphate solubilization. Four ACC deaminase-containing endophytic bacteria strains named as LP11, SS12, TW1 and TW2 were isolated and identified as Pseudomonas oryzihabitans, Pseudomonas sp., Pantoea agglomerans and Pseudomonas putida respectively. All the strains possessed the phosphate-solubilizing ability and could produce siderophores and phytohormones more or less. None of them could fix atmospheric nitrogen or produce protease. Only strain SS12 showed antagonism against two phytopathogenic fungi viz Fusarium oxysporum f. sp. conglutinans and F. oxysporum f. sp. cucumerinum. ACC deaminase-containing endophytic bacteria of Pseudomonas sp. and Pantoea sp. isolated from halophyte Suaeda salsa have abundant biological characteristics related to plant growth promotion, stress homeostasis regulation and biocontrol activity.

From Farms to Markets: Gram-Negative Bacteria Resistant to Third-Generation Cephalosporins in Fruits and Vegetables in a Region of North Africa

PubMed Central

Mesbah Zekar, Ferielle; Granier, Sophie A.; Marault, Muriel; Yaici, Lydia; Gassilloud, Benoit; Manceau, Charles; Touati, Abdelaziz; Millemann, Yves

2017-01-01

The role of food in human exposure to antimicrobial-resistant bacteria is a growing food safety issue. The contribution of fruits and vegetables eaten raw to this exposure is still unclear. The evaluation of contamination levels of fruits, vegetables and the agricultural environment by third-generation cephalosporin (3GC)-resistant Gram-negative bacteria was performed by analyzing 491 samples of fruits and vegetables collected from 5 markets and 7 farms in Bejaia area, north-eastern Mediterranean coast of Algeria. Ninety soil samples and 45 irrigation water samples were also sampled in farms in order to assess them as potential inoculum sources. All samples were investigated at the same time on ceftazidime-containing selective media for 3GC-resistant Gram-negative bacteria detection and on Hektoen media, for Salmonella spp. presence. The bacteria isolated (n = 30) from fruits and vegetables, soil and irrigation water collected in the farms were almost all non-fermenting bacterial species (Stenotrophomonas, Acinetobacter, Pseudomonas, Ochrobactrum) except one strain of Enterobacter cloacae and two strains of Citrobacter murliniae, isolated on one cucumber and two tomato samples in the same farm. Greater diversity in bacterial species and antimicrobial resistance profiles was observed at markets: Enterobacteriaceae (n = 41) were as strongly represented as non-fermenting bacteria (n = 37). Among Enterobacteriaceae, E. cloacae (n = 21), and Klebsiella pneumoniae (n = 13) were the most common isolates. Most of the K. pneumoniae isolates were extended-spectrum beta-lactamase (ESBL) producers (n = 11). No Salmonella spp. was recovered in any sample. This study showed that fruits and vegetables including those which may be eaten up raw constitute a reservoir of 3GC-resistant Gram-negative bacteria and multi-drug resistant-bacteria in general that can be transferred to humans through food. The general public should be informed of this hazard for health in order to encourage

Isolation of Lightning-Competent Soil Bacteria

PubMed Central

Cérémonie, Hélène; Buret, François; Simonet, Pascal; Vogel, Timothy M.

2004-01-01

Artificial transformation is typically performed in the laboratory by using either a chemical (CaCl2) or an electrical (electroporation) method. However, laboratory-scale lightning has been shown recently to electrotransform Escherichia coli strain DH10B in soil. In this paper, we report on the isolation of two “lightning-competent” soil bacteria after direct electroporation of the Nycodenz bacterial ring extracted from prairie soil in the presence of the pBHCRec plasmid (Tcr, Spr, Smr). The electrotransformability of the isolated bacteria was measured both in vitro (by electroporation cuvette) and in situ (by lightning in soil microcosm) and then compared to those of E. coli DH10B and Pseudomonas fluorescens C7R12. The electrotransformation frequencies measured reached 10−3 to 10−4 by electroporation and 10−4 to 10−5 by simulated lightning, while no transformation was observed in the absence of electrical current. Two of the isolated lightning-competent soil bacteria were identified as Pseudomonas sp. strains. PMID:15466589

Inhibition of fish bacteria pathogen in tilapia using a concoction three of Borneo plant extracts

NASA Astrophysics Data System (ADS)

Hardi, EH; Saptiani, G.; Kusuma, IW; Suwinarti, W.; Sudaryono, A.

2018-04-01

This study was conducted to evaluate the antibacterial activity of concoction Solanum ferox, Boesenbergia pandurata and Zingimber zerumbetextract (SF, BP, and ZZ) to inhibit pathogenic bacteria in tilapia with the each concentrations 600 ppm BP, 900 ppm SF and 200 ppm ZZ. Antibacterial activity was measured by testing the concoction of three plants extract against single isolate Aeromonas hydrophila and Pseudomonas sp. and combined both bacteria (105 colony-forming units per milliliter). In this research, oxytetracycline was used as a control. Clear zone inhibition was observed at 6, 12, 18 and 24 hours after incubation at 30 °C. The results showed that the different concoction of BP: SF: ZZ have inhibitory zones against both single and joint isolate bacteria. The ratio of3:3:4 and 1:8:1 had higher antibacterial activity towards Pseudomonas sp. and 1:1:3 ratios both inhibit joint bacteria. The ZI% higher of concoction extracts against A.hydrophila is 1:1:8; 1:3:1; 3:4:3. The ZI% concoction extracts against Pseudomonas sp. ware 3:3:4 and 1:8:1 ratio. While the two bacteria combined, just 1:1:3 ratio had higher Z%. The conclusion is that a concoction of SF:BP:ZZ is effective to inhibit the growth of A.hydrophila and Pseudomonas sp., even its antibacterial ability is similar to the effectiveness of antibiotic oxytetracycline.

Pseudomonas protegens Pf-5 causes discoloration and pitting of mushroom caps due to the production of antifungal metabolites

USDA-ARS?s Scientific Manuscript database

Bacteria in the diverse P. fluorescens group include mushroom pathogens, such as Pseudomonas tolaasii, and rhizosphere inhabitants known for their antifungal metabolite production and biological control of plant disease, such as Pseudomonas protegens Pf-5. Here, we report that strain Pf-5 causes bro...

Interactions of Nitrifying Bacteria and Heterotrophs: Identification of a Micavibrio-Like Putative Predator of Nitrospira spp.

PubMed Central

Dolinšek, Jan; Lagkouvardos, Ilias; Wanek, Wolfgang; Wagner, Michael

2013-01-01

Chemolithoautotrophic nitrifying bacteria release soluble organic compounds, which can be substrates for heterotrophic microorganisms. The identities of these heterotrophs and the specificities of their interactions with nitrifiers are largely unknown. In this study, we incubated nitrifying activated sludge with 13C-labeled bicarbonate and used stable isotope probing of 16S rRNA to monitor the flow of carbon from uncultured nitrifiers to heterotrophs. To facilitate the identification of heterotrophs, the abundant 16S rRNA molecules from nitrifiers were depleted by catalytic oligonucleotides containing locked nucleic acids (LNAzymes), which specifically cut the 16S rRNA of defined target organisms. Among the 13C-labeled heterotrophs were organisms remotely related to Micavibrio, a microbial predator of Gram-negative bacteria. Fluorescence in situ hybridization revealed a close spatial association of these organisms with microcolonies of nitrite-oxidizing sublineage I Nitrospira in sludge flocs. The high specificity of this interaction was confirmed by confocal microscopy and a novel image analysis method to quantify the localization patterns of biofilm microorganisms in three-dimensional (3-D) space. Other isotope-labeled bacteria, which were affiliated with Thermomonas, colocalized less frequently with nitrifiers and thus were commensals or saprophytes rather than specific symbionts or predators. These results suggest that Nitrospira spp. are subject to bacterial predation, which may influence the abundance and diversity of these nitrite oxidizers and the stability of nitrification in engineered and natural ecosystems. In silico screening of published next-generation sequencing data sets revealed a broad environmental distribution of the uncultured Micavibrio-like lineage. PMID:23335755

Bacterial Contamination of Boar Semen and its Relationship to Sperm Quality Preserved in Commercial Extender Containing Gentamicin Sulfate.

PubMed

Gączarzewicz, D; Udała, J; Piasecka, M; Błaszczyk, B; Stankiewicz, T

2016-09-01

This study was designed to determine the degree and type of bacterial contamination in boar semen (79 ejaculates from Large White and Landrace boars) and its consequences for sperm quality during storage (27 extended semen samples, 16°C for five days) under practical conditions of artificial insemination (AI). The results revealed the presence of aerobic bacteria in 99% of the ejaculates (from 80 to 370 ×106 colony-forming units/mL). Most of the ejaculates contained two or three bacterial contaminants, while the Staphylococcus, Streptococcus, and Pseudomonas bacterial genera were most frequently isolated. Also detected were Enterobacter spp., Bacillus spp., Proteus spp., Escherichia coli, P. fluorescens, and P. aeruginosa. In general, the growth of certain bacterial types isolated prior to semen processing (Enterobacter spp., E. coli, P. fluorescens, and P. aeruginosa) was not discovered on different days of storage, but fluctuations (with a tendency towards increases) were found in the frequencies of Bacillus spp., Pseudomonas spp., and Staphylococcus spp. isolates up to the end of storage. Semen preserved for five days exhibited decreases in sperm motility and increases in the average number of total aerobic bacteria; this was associated with sperm agglutination, plasma membrane disruption, and acrosome damage. We inferred that, due to the different degrees and types of bacterial contaminants in the boar ejaculates, the inhibitory activity of some antimicrobial agents used in swine extenders (such as gentamicin sulfate) may be limited. Because such agents can contribute to the overgrowth of certain aerobic bacteria and a reduction in the quality of stored semen, procedures with high standards of hygiene and microbiological control should be used when processing boar semen.

Insect Pathogenic Bacteria in Integrated Pest Management

PubMed Central

Ruiu, Luca

2015-01-01

The scientific community working in the field of insect pathology is experiencing an increasing academic and industrial interest in the discovery and development of new bioinsecticides as environmentally friendly pest control tools to be integrated, in combination or rotation, with chemicals in pest management programs. In this scientific context, market data report a significant growth of the biopesticide segment. Acquisition of new technologies by multinational Ag-tech companies is the center of the present industrial environment. This trend is in line with the requirements of new regulations on Integrated Pest Management. After a few decades of research on microbial pest management dominated by Bacillus thuringiensis (Bt), novel bacterial species with innovative modes of action are being discovered and developed into new products. Significant cases include the entomopathogenic nematode symbionts Photorhabdus spp. and Xenorhabdus spp., Serratia species, Yersinia entomophaga, Pseudomonas entomophila, and the recently discovered Betaproteobacteria species Burkholderia spp. and Chromobacterium spp. Lastly, Actinobacteria species like Streptomyces spp. and Saccharopolyspora spp. have gained high commercial interest for the production of a variety of metabolites acting as potent insecticides. With the aim to give a timely picture of the cutting-edge advancements in this renewed research field, different representative cases are reported and discussed. PMID:26463190

The ACC deaminase expressing endophyte Pseudomonas spp. Enhances NaCl stress tolerance by reducing stress-related ethylene production, resulting in improved growth, photosynthetic performance, and ionic balance in tomato plants.

PubMed

Win, Khin Thuzar; Fukuyo, Tanaka; Keiki, Okazaki; Ohwaki, Yoshinari

2018-06-01

Plant growth promoting bacteria (PGPB) endophytes that express 1-aminocyclopropane-1-carboxylate (ACC) deaminase reportedly confer plant tolerance to abiotic stresses such as salinity by lowering stress-related ethylene levels. Two preselected ACC deaminase expressing endophytic Pseudomonas spp. strains, OFT2 and OFT5, were compared in terms of their potential to promote plant growth, leaf water contents, photosynthetic performance, and ionic balance of tomato plants under conditions of moderate NaCl stress (75 mM). Salinity stress strongly affected growth, leaf water contents, and photosynthetic performance of tomato seedlings, and inoculation with either OFT2 or OFT5 ameliorated these adverse effects. Decreases in plant biomass due to salinity stress were significant in both uninoculated control plants and in plants inoculated with OFT2 compared with plants without NaCl stress. However, no reductions in total biomass were observed in plants that were inoculated with the OFT5 strain. Strain OFT5 influenced growth, physiological status, and ionic balance of tomato plants more efficiently than strain OFT2 under NaCl stress. In particular, inoculated OFT5 reduced salt-induced ethylene production by tomato seedlings, and although it did not reduce shoot uptake of Na, it promoted shoot uptake of other macronutrients (P, K, and Mg) and micronutrients (Mn, Fe, Cu, and Zn). These nutrients may activate processes that alleviate the effects of salt, suggesting that OFT5 can be used to improve nutrient uptake and plant growth under moderate salt-affected conditions by reducing stress-related ethylene levels. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Antagonism of Lactic Acid Bacteria against Phytopathogenic Bacteria

PubMed Central

Visser, Ronèl; Holzapfel, Wilhelm H.; Bezuidenhout, Johannes J.; Kotzé, Johannes M.

1986-01-01

A variety of lactic acid bacteria, isolated from plant surfaces and plant-associated products, were found to be antagonistic to test strains of the phytopathogens Xanthomonas campestris, Erwinia carotovora, and Pseudomonas syringae. Effective “in vitro” inhibition was found both on agar plates and in broth cultures. In pot trials, treatment of bean plants with a Lactobacillus plantarum strain before inoculation with P. syringae caused a significant reduction of the disease incidence. Images PMID:16347150

Regrowth of potential opportunistic pathogens and algae in reclaimed-water distribution systems.

PubMed

Jjemba, Patrick K; Weinrich, Lauren A; Cheng, Wei; Giraldo, Eugenio; Lechevallier, Mark W

2010-07-01

A study of the quality of reclaimed water in treated effluent, after storage, and at three points in the distribution system of four plants in California, Florida, Massachusetts, and New York was conducted for 1 year. The plants had different treatment processes (conventional versus membrane bioreactor), production capacities, and methods for storage of the water, and the intended end uses of the water were different. The analysis focused on the occurrence of indicator bacteria (heterotrophic bacteria, coliforms, Escherichia coli, and enterococci) and opportunistic pathogens (Aeromonas spp., enteropathogenic E. coli O157:H7, Legionella spp., Mycobacterium spp., and Pseudomonas spp.), as well as algae. Using immunological methods, E. coli O157:H7 was detected in the effluent of only one system, but it was not detected at the sampling points, suggesting that its survival in the system was poor. Although all of the treatment systems effectively reduced the levels of bacteria in the effluent, bacteria regrew in the reservoir and distribution systems because of the loss of residual disinfectant and high assimilable organic carbon levels. In the systems with open reservoirs, algal growth reduced the water quality by increasing the turbidity and accumulating at the end of the distribution system. Opportunistic pathogens, notably Aeromonas, Legionella, Mycobacterium, and Pseudomonas, occurred more frequently than indicator bacteria (enterococci, coliforms, and E. coli). The Mycobacterium spp. were very diverse and occurred most frequently in membrane bioreactor systems, and Mycobacterium cookii was identified more often than the other species. The public health risk associated with these opportunistic pathogens in reclaimed water is unknown. Collectively, our results show the need to develop best management practices for reclaimed water to control bacterial regrowth and degradation of water before it is utilized at the point of use.

Regrowth of Potential Opportunistic Pathogens and Algae in Reclaimed-Water Distribution Systems ▿

PubMed Central

Jjemba, Patrick K.; Weinrich, Lauren A.; Cheng, Wei; Giraldo, Eugenio; LeChevallier, Mark W.

2010-01-01

A study of the quality of reclaimed water in treated effluent, after storage, and at three points in the distribution system of four plants in California, Florida, Massachusetts, and New York was conducted for 1 year. The plants had different treatment processes (conventional versus membrane bioreactor), production capacities, and methods for storage of the water, and the intended end uses of the water were different. The analysis focused on the occurrence of indicator bacteria (heterotrophic bacteria, coliforms, Escherichia coli, and enterococci) and opportunistic pathogens (Aeromonas spp., enteropathogenic E. coli O157:H7, Legionella spp., Mycobacterium spp., and Pseudomonas spp.), as well as algae. Using immunological methods, E. coli O157:H7 was detected in the effluent of only one system, but it was not detected at the sampling points, suggesting that its survival in the system was poor. Although all of the treatment systems effectively reduced the levels of bacteria in the effluent, bacteria regrew in the reservoir and distribution systems because of the loss of residual disinfectant and high assimilable organic carbon levels. In the systems with open reservoirs, algal growth reduced the water quality by increasing the turbidity and accumulating at the end of the distribution system. Opportunistic pathogens, notably Aeromonas, Legionella, Mycobacterium, and Pseudomonas, occurred more frequently than indicator bacteria (enterococci, coliforms, and E. coli). The Mycobacterium spp. were very diverse and occurred most frequently in membrane bioreactor systems, and Mycobacterium cookii was identified more often than the other species. The public health risk associated with these opportunistic pathogens in reclaimed water is unknown. Collectively, our results show the need to develop best management practices for reclaimed water to control bacterial regrowth and degradation of water before it is utilized at the point of use. PMID:20453149

Early Arabidopsis root hair growth stimulation by pathogenic strains of Pseudomonas syringae.

PubMed

Pecenková, Tamara; Janda, Martin; Ortmannová, Jitka; Hajná, Vladimíra; Stehlíková, Zuzana; Žárský, Viktor

2017-09-01

Selected beneficial Pseudomonas spp. strains have the ability to influence root architecture in Arabidopsis thaliana by inhibiting primary root elongation and promoting lateral root and root hair formation. A crucial role for auxin in this long-term (1week), long-distance plant-microbe interaction has been demonstrated. Arabidopsis seedlings were cultivated in vitro on vertical plates and inoculated with pathogenic strains Pseudomonas syringae pv. maculicola (Psm) and P. syringae pv. tomato DC3000 (Pst), as well as Agrobacterium tumefaciens (Atu) and Escherichia coli (Eco). Root hair lengths were measured after 24 and 48h of direct exposure to each bacterial strain. Several Arabidopsis mutants with impaired responses to pathogens, impaired ethylene perception and defects in the exocyst vesicle tethering complex that is involved in secretion were also analysed. Arabidopsis seedling roots infected with Psm or Pst responded similarly to when infected with plant growth-promoting rhizobacteria; root hair growth was stimulated and primary root growth was inhibited. Other plant- and soil-adapted bacteria induced similar root hair responses. The most compromised root hair growth stimulation response was found for the knockout mutants exo70A1 and ein2. The single immune pathways dependent on salicylic acid, jasmonic acid and PAD4 are not directly involved in root hair growth stimulation; however, in the mutual cross-talk with ethylene, they indirectly modify the extent of the stimulation of root hair growth. The Flg22 peptide does not initiate root hair stimulation as intact bacteria do, but pretreatment with Flg22 prior to Psm inoculation abolished root hair growth stimulation in an FLS2 receptor kinase-dependent manner. These early response phenomena are not associated with changes in auxin levels, as monitored with the pDR5::GUS auxin reporter. Early stimulation of root hair growth is an effect of an unidentified component of living plant pathogenic bacteria. The root

Biocontrol Efficacy of Formulated Pseudomonas chlororaphis O6 against Plant Diseases and Root-Knot Nematodes

PubMed Central

Nam, Hyo Song; Anderson, Anne J.; Kim, Young Cheol

2018-01-01

Commercial biocontrol of microbial plant diseases and plant pests, such as nematodes, requires field-effective formulations. The isolate Pseudomonas chlororaphis O6 is a Gram-negative bacterium that controls microbial plant pathogens both directly and indirectly. This bacterium also has nematocidal activity. In this study, we report on the efficacy of a wettable powder-type formulation of P. chlororaphis O6. Culturable bacteria in the formulated product were retained at above 1 × 108 colony forming units/g after storage of the powder at 25 °C for six months. Foliar application of the diluted formulated product controlled leaf blight and gray mold in tomato. The product also displayed preventative and curative controls for root-knot nematode (Meloidogyne spp.) in tomato. Under laboratory conditions and for commercially grown melon, the control was at levels comparable to that of a standard commercial chemical nematicide. The results indicated that the wettable powder formulation product of P. chlororaphis O6 can be used for control of plant microbial pathogens and root-knot nematodes. PMID:29887780

Indigenous bacteria and bacterial metabolic products in the gastrointestinal tract of broiler chickens.

PubMed

Rehman, Habib Ur; Vahjen, Wilfried; Awad, Wageha A; Zentek, Jürgen

2007-10-01

The gastrointestinal tract is a dynamic ecosystem containing a complex microbial community. In this paper, the indigenous intestinal bacteria and the microbial fermentation profile particularly short chain fatty acids (SCFA), lactate, and ammonia concentrations are reviewed. The intestinal bacterial composition changes with age. The bacterial density of the small intestine increases with age and comprises of lactobacilli, streptococci, enterobacteria, fusobacteria and eubacteria. Strict anaerobes (anaerobic gram-positive cocci, Eubacterium spp., Clostridium spp., Lactobacillus spp., Fusobacterium spp. and Bacteroides) are predominating caecal bacteria in young broilers. Data from culture-based studies showed that bifidobacteria could not be isolated from young birds, but were recovered from four-week-old broilers. Caecal lactobacilli accounted for 1.5-24% of the caecal bacteria. Gene sequencing of caecal DNA extracts showed that the majority of bacteria belonged to Clostridiaceae. Intestinal bacterial community is influenced by the dietary ingredients, nutrient levels and physical structure of feed. SCFA and other metabolic products are affected by diet formulation and age. Additional studies are required to know the bacterial metabolic activities together with the community analysis of the intestinal bacteria. Feed composition and processing have great potential to influence the activities of intestinal bacteria towards a desired direction in order to support animal health, well-being and microbial safety of broiler meat.

Phenotypic and genotypic characterization of phenanthrene-degrading fluorescent Pseudomonas biovars.

PubMed Central

Johnsen, K; Andersen, S; Jacobsen, C S

1996-01-01

A total of 41 phenanthrene degraders were isolated from a former coal gasification site by using Pseudomonas-selective Gould's S1 medium. All isolates were found to belong to the fluorescent Pseudomonas group and were subjected to characterization by phenotypic methods, including classical taxonomic tests, API 20NE, and Biolog GN, and the strains were further characterized by the genotypic method repetitive extragenic palindromic PCR (REP-PCR). By using classical tests, the population was found to consist of 38 strains belonging to P. fluorescens, 2 P. putida strains, and 1 Pseudomonas sp. Bacteria in phenograms from Biolog GN and REP-PCR data were divided into groups, which were in good agreement with classical test and API 20NE results. We found a nonfluorescent group of 22 bacteria inconsistent with any Pseudomonas sp. in Bergey's Manual of Systematic Bacteriology. The group showed small differences in the genotypic test, indicating that all 22 isolates were not recent clones of the same isolate. Analyses of the nonfluorescent group indicated that it belonged to Pseudomonas, but the group could not be affiliated with P. fluorescens because of differences in DNA-DNA hybridization. Identifications using classical tests and API 20NE were found to correlate, but Biolog GN identifications after 24-h incubation resulted very often in the distantly related P. corrugata. The reproducibilities of individual tests of each phenotypic method were assessed, and low reproducibilities were mainly found to be associated with specific Biolog GN test wells. Classical tests and API 20NE proved to be the best for identification of isolates, whereas Biolog GN and REP-PCR were found to be the best tests for high resolution among these closely related isolates. PMID:8837438

Inactivation of bacteria via photosensitization of vitamin K3 by UV-A light.

PubMed

Xu, Fei; Vostal, Jaroslav G

2014-09-01

This study investigated inactivation of bacteria with ultraviolet light A irradiation in combination with vitamin K3 as a photosensitizer. Six bacteria including Bacillus cereus, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella pneumoniae, and Escherichia coli suspended in vitamin K3 aqueous solution were exposed to ultraviolet light A. Five of six bacteria, with the exception of Pseudomonas aeruginosa, were reduced by eight logs with 1600 μM of vitamin K3 and 5.8 J cm(-2) UV-A irradiation. Pseudomonas aeruginosa was reduced by four logs under these conditions. Reactive oxygen species including singlet oxygen, hydroxyl radical and superoxide anion radical were generated in vitamin K3 aqueous solution under UV-A irradiation. These results suggest that vitamin K3 and UV-A irradiation may be effective for bacterial inactivation in environmental and medical applications. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

[The action of quaternary ammonium derivatives on respiration and nitrate reduction in Pseudomonas aeruginosa].

PubMed

Bievskiĭ, A N

1994-01-01

It was revealed that the same dosages of quaternary ammonium derivatives, such as decamethoxin and cetyltrimethylammonium bromide, inhibited the respiratory chains and caused destruction of Pseudomonas aeruginosa under aerobic conditions more effectively than under anaerobic ones when anions of nitric acid were the terminal acceptors of electrons. It was also registered that Pseudomonas were able to dissimilatory nitrate reduction in the media under the polysaccharide layer that was produced by these bacteria: this fact possibly proves the possibility of survival of denitrifying bacteria in solutions with high concentrations of quaternary ammonium salts. The data obtained permit supposing that inhibitors of respiratory chains and oxidizers may be used as potentiators of the antimicrobial action of quaternary ammonium derivatives.

Genotypic and phenotypic diversity in populations of plant-probiotic Pseudomonas spp. colonizing roots

NASA Astrophysics Data System (ADS)

Picard, Christine; Bosco, Marco

2008-01-01

Several soil microorganisms colonizing roots are known to naturally promote the health of plants by controlling a range of plant pathogens, including bacteria, fungi, and nematodes. The use of theses antagonistic microorganisms, recently named plant-probiotics, to control plant-pathogenic fungi is receiving increasing attention, as they may represent a sustainable alternative to chemical pesticides. Many years of research on plant-probiotic microorganisms (PPM) have indicated that fluorescent pseudomonads producing antimicrobial compounds are largely involved in the suppression of the most widespread soilborne pathogens. Phenotype and genotype analysis of plant-probiotic fluorescent pseudomonads (PFP) have shown considerable genetic variation among these types of strains. Such variability plays an important role in the rhizosphere competence and the biocontrol ability of PFP strains. Understanding the mechanisms by which genotypic and phenotypic diversity occurs in natural populations of PFP could be exploited to choose those agricultural practices which best exploit the indigenous PFP populations, or to isolate new plant-probiotic strains for using them as inoculants. A number of different methods have been used to study diversity within PFP populations. Because different resolutions of the existing microbial diversity can be revealed depending on the approach used, this review first describes the most important methods used for the assessment of fluorescent Pseudomonas diversity. Then, we focus on recent data relating how differences in genotypic and phenotypic diversity within PFP communities can be attributed to geographic location, climate, soil type, soil management regime, and interactions with other soil microorganisms and host plants. It becomes evident that plant-related parameters exert the strongest influence on the genotypic and phenotypic variations in PFP populations.

Linking TFT-LCD wastewater treatment performance to microbial population abundance of Hyphomicrobium and Thiobacillus spp.

PubMed

Fukushima, Toshikazu; Whang, Liang-Ming; Chen, Po-Chun; Putri, Dyah Wulandari; Chang, Ming-Yu; Wu, Yi-Ju; Lee, Ya-Ching

2013-08-01

This study investigated the linkage between performance of two full-scale membrane bioreactor (MBR) systems treating thin-film transistor liquid crystal display (TFT-LCD) wastewater and the population dynamics of dimethylsulfoxide (DMSO)/dimethylsulfide (DMS) degrading bacteria. High DMSO degradation efficiencies were achieved in both MBRs, while the levels of nitrification inhibition due to DMS production from DMSO degradation were different in the two MBRs. The results of real-time PCR targeting on DMSO/DMS degrading populations, including Hyphomicrobium and Thiobacillus spp., indicated that a higher DMSO oxidation efficiency occurred at a higher Hyphomicrobium spp. abundance in the systems, suggesting that Hyphomicrobium spp. may be more important for complete DMSO oxidation to sulfate compared with Thiobacillus spp. Furthermore, Thiobacillus spp. was more abundant during poor nitrification, while Hyphomicrobium spp. was more abundant during good nitrification. It is suggested that microbial population of DMSO/DMS degrading bacteria is closely linking to both DMSO/DMS degradation efficiency and nitrification performance. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ultrastructural localization of acid phosphatase in some bacteria, after treatment with Lubrol W1.

PubMed

Cherepova, N; Spasova, D

1996-01-01

The ultracytochemical localization of acid phosphatase from some bacteria (Listeria monocytogenes, Salmonella typhimurium, Pseudomonas pseudomallei and Pseudomonas aeruginosa) was dependent on the changes in the lipoprotein content of the membranes as a result of the action of the Lubrol W1.

Survival of Escherichia coli and Salmonella spp. in estuarine environments.

PubMed Central

Rhodes, M W; Kator, H

1988-01-01

Survival of Escherichia coli and Salmonella spp. in estuarine waters was compared over a variety of seasonal temperatures during in situ exposure in diffusion chambers. Sublethal stress was measured by both selective-versus-resuscitative enumeration procedures and an electrochemical detection method. E. coli and Salmonella spp. test suspensions, prepared to minimize sublethal injury, were exposed in a shallow tidal creek and at a site 7.1 km further downriver. Bacterial die-off and sublethal stress in filtered estuarine water were inversely related to water temperature. Salmonella spp. populations exhibited significantly less die-off and stress than did E. coli at water temperatures of less than 10 degrees C. Although the most pronounced reductions (ca. 3 log units) in test bacteria occurred during seasonally warm temperatures in the presence of the autochthonous microbiota, 10(2) to 10(4) test cells per ml remained after 2 weeks of exposure to temperatures of greater than 15 degrees C. Reductions in test bacteria were associated with increases in the densities of microflagellates and plaque-forming microorganisms. These studies demonstrated the survival potential of enteric bacteria in estuarine waters and showed that survival was a function of interacting biological and physical factors. PMID:3066291

Biofouling of groundwater systems by Thiothrix spp.

PubMed

Brigmon, R L; Martin, H W; Aldrich, H C

1997-09-01

Thiothrix spp., sulfide-oxidizing filamentous bacteria, were found to be a principal bacterial component of aquatic biofilms causing biofouling in selected municipal water storage tanks, private wells, and drip irrigation systems in Florida. Treatments of up to 200 ppm chlorine in the affected systems could not prevent return of the biofouling problem. The water originated from the upper Floridan aquifer and associated surficial aquifers in central and north Florida. Samples were examined where visible biofilms had a white, filamentous appearance, indicative of Thiothrix spp. The detection of Thiothrix spp. was confirmed by enzyme-liked immunosorbent assay (ELISA), indirect immunofluorescence (IIF), and microbiological procedures. It was estimated through immunocytochemical procedures that Thiothrix spp. comprised 18% of the biofilm in the municipal water storage tanks. These observations confirm that specific biological and chemical interactions may induce physical changes leading to significant biofouling.

Associations of endodontic symptoms and signs with particular combinations of specific bacteria.

PubMed

Gomes, B P; Lilley, J D; Drucker, D B

1996-03-01

Significant associations have been reported between (a) specific bacterial species isolated from root canals and (b) between individual bacterial species and endodontic symptoms and signs. The prime objective of this study was to determine whether particular combinations of specific bacteria are associated with individual endodontic symptoms and signs. Seventy root canals were investigated microbiologically taking care to maintain the viability of obligate anaerobes, which accounted for 64% of the total species isolated, including Peptostreptococcus micros, Prevotella melaninogenica, Prevotella oralis, Eubacterium aerofaciens, Eubacterium lentum, Fusobacterium nucleatum, Prevotella buccae and Prevotella intermedia. Significant associations were found between individual clinical features and the following pairs of species: (a) pain (37 cases) and Peptostreptococcus spp./Prevotella spp., Peptostreptococcus spp./Prevotella melaninogenica, Pstr. micros/Prev. melaninogenica (all P < 0.01); (b) swelling (23 cases) and Pstr. micros/Prevotella spp. (P < 0.01); (c) 'Wet' canal (57 cases) and Prevotella spp./Eubacterium spp. (P < 0.01), Peptostreptococcus spp./Eubacterium spp. (P < 0.05). Thus data from this investigation suggests that statistically significant associations exist between individual endodontic symptoms and signs and particular combinations of specific bacteria.

Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance.

PubMed

Magiorakos, A-P; Srinivasan, A; Carey, R B; Carmeli, Y; Falagas, M E; Giske, C G; Harbarth, S; Hindler, J F; Kahlmeter, G; Olsson-Liljequist, B; Paterson, D L; Rice, L B; Stelling, J; Struelens, M J; Vatopoulos, A; Weber, J T; Monnet, D L

2012-03-01

Many different definitions for multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) bacteria are being used in the medical literature to characterize the different patterns of resistance found in healthcare-associated, antimicrobial-resistant bacteria. A group of international experts came together through a joint initiative by the European Centre for Disease Prevention and Control (ECDC) and the Centers for Disease Control and Prevention (CDC), to create a standardized international terminology with which to describe acquired resistance profiles in Staphylococcus aureus, Enterococcus spp., Enterobacteriaceae (other than Salmonella and Shigella), Pseudomonas aeruginosa and Acinetobacter spp., all bacteria often responsible for healthcare-associated infections and prone to multidrug resistance. Epidemiologically significant antimicrobial categories were constructed for each bacterium. Lists of antimicrobial categories proposed for antimicrobial susceptibility testing were created using documents and breakpoints from the Clinical Laboratory Standards Institute (CLSI), the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the United States Food and Drug Administration (FDA). MDR was defined as acquired non-susceptibility to at least one agent in three or more antimicrobial categories, XDR was defined as non-susceptibility to at least one agent in all but two or fewer antimicrobial categories (i.e. bacterial isolates remain susceptible to only one or two categories) and PDR was defined as non-susceptibility to all agents in all antimicrobial categories. To ensure correct application of these definitions, bacterial isolates should be tested against all or nearly all of the antimicrobial agents within the antimicrobial categories and selective reporting and suppression of results should be avoided. © 2011 European Society of Clinical Microbiology and Infectious Diseases. No claim to original US government works.

Chemical resistance of the gram-negative bacteria to different sanitizers in a water purification system

PubMed Central

Mazzola, Priscila G; Martins, Alzira MS; Penna, Thereza CV

2006-01-01

Background Purified water for pharmaceutical purposes must be free of microbial contamination and pyrogens. Even with the additional sanitary and disinfecting treatments applied to the system (sequential operational stages), Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were isolated and identified from a thirteen-stage purification system. To evaluate the efficacy of the chemical agents used in the disinfecting process along with those used to adjust chemical characteristics of the system, over the identified bacteria, the kinetic parameter of killing time (D-value) necessary to inactivate 90% of the initial bioburden (decimal reduction time) was experimentally determined. Methods Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were called in house (wild) bacteria. Pseudomonas diminuta ATCC 11568, Pseudomonas alcaligenes INCQS , Pseudomonas aeruginosa ATCC 15442, Pseudomonas fluorescens ATCC 3178, Pseudomonas picketti ATCC 5031, Bacillus subtilis ATCC 937 and Escherichia coli ATCC 25922 were used as 'standard' bacteria to evaluate resistance at 25°C against either 0.5% citric acid, 0.5% hydrochloric acid, 70% ethanol, 0.5% sodium bisulfite, 0.4% sodium hydroxide, 0.5% sodium hypochlorite, or a mixture of 2.2% hydrogen peroxide (H2O2) and 0.45% peracetic acid. Results The efficacy of the sanitizers varied with concentration and contact time to reduce decimal logarithmic (log10) population (n cycles). To kill 90% of the initial population (or one log10 cycle), the necessary time (D-value) was for P. aeruginosa into: (i) 0.5% citric acid, D = 3.8 min; (ii) 0.5% hydrochloric acid, D = 6.9 min; (iii) 70% ethanol, D = 9.7 min; (iv) 0.5% sodium bisulfite, D = 5.3 min; (v) 0.4% sodium hydroxide, D = 14.2 min; (vi) 0.5% sodium hypochlorite

Olivine dissolution in the presence of heterotrophic bacteria (Pseudomonas reactants) extracted from Icelandic groundwater of the CO2 injection pilot site

NASA Astrophysics Data System (ADS)

Shirokova, Liudmila; Pokrovsky, Oleg; Benezeth, Pascale; Gerard, Emmanuelle; Menez, Benedicte; Alfredsson, Helgi

2010-05-01

This work is aimed at experimental modeling of the effect of heterotrophic bacteria on dissolution of important rock-forming mineral, olivine, at the conditions of CO2 storage and sequestration. Heterotrophic aerobic gram-negative bacteria were extracted from deep underground water (HK31, 1700 m deep and, t = 25-30°C) of basaltic aquifer located within the Hellisheidi CO2 injection pilot site (Iceland). Following this sampling, we separated, using culture on nutrient agar plates, four different groups of gram-negative aerobic bacteria. The enzymatic activity of studied species has been evaluated using Biolog Ecoplates and their genetic identification was performed using 18-S RNA analysis. The optimal growth conditions of bacteria on Brain Hearth Broth nutrient have been determined as 5 to 37°C and growth media pH varied from 7.0-8.2. Culturing experiments allowed determining the optimal physico-chemical conditions for bacteria experiments in the presence of basic Ca, Mg-containing silicates. Olivine (Fo92) was chosen as typical mineral of basalt, widely considered in carbon dioxide sequestration mechanisms. Dissolution experiments were performed in constant-pH (7 to 9), bicarbonate-buffered (0.001 to 0.05 M) nutrient-diluted media in batch reactors at 0-30 bars of CO2 in the presence of various biomass of Pseudomonas reactants. The release rate of magnesium, silica and iron was measured as a function of time in the presence of live, actively growing, dead (autoclaved or glutaraldehyde-treated) cells and bacteria exometabolites. Both nutrient media diluted 10 times (to 100 mg DOC/L) and inert electrolyte (NaCl, no DOC) were used. Our preliminary results indicate that the pH and dissolved organic matter are the first-order parameters that control the element release from olivine at far from equilibrium conditions. The SEM investigation of reacted surfaces reveal formation of surface roughness with much stronger mineral alteration in the presence of live bacteria

Determination of antibiotic resistance of lactic acid bacteria isolated from traditional Turkish fermented dairy products.

PubMed

Erginkaya, Z; Turhan, E U; Tatlı, D

2018-01-01

In this study, the antibiotic resistance (AR) of lactic acid bacteria (LAB) isolated from traditional Turkish fermented dairy products was investigated. Yogurt, white cheese, tulum cheese, cokelek, camız cream and kefir as dairy products were collected from various supermarkets. Lactic acid bacteria such as Lactobacillus spp., Streptococcus spp., Bifidobacterium spp., and Enterecoccus spp. were isolated from these dairy products. Lactobacillus spp. were resistant to vancomycin (58%), erythromycin (10.8%), tetracycline (4.3%), gentamicin (28%), and ciprofloxacin (26%). Streptococcus spp. were resistant to vancomycin (40%), erythromycin (10%), chloramphenicol (10%), gentamicin (20%), and ciprofloxacin (30%). Bifidobacterium spp. were resistant to vancomycin (60%), E 15 (6.6%), gentamicin (20%), and ciprofloxacin (33%). Enterococcus spp. were resistant to vancomycin (100%), erythromycin (100%), rifampin (100%), and ciprofloxacin (100%). As a result, LAB islated from dairy products in this study showed mostly resistance to vancomycin.

Testing nano-silver food packaging to evaluate silver migration and food spoilage bacteria on chicken meat.

PubMed

Gallocchio, Federica; Cibin, Veronica; Biancotto, Giancarlo; Roccato, Anna; Muzzolon, Orietta; Carmen, Losasso; Simone, Belluco; Manodori, Laura; Fabrizi, Alberto; Patuzzi, Ilaria; Ricci, Antonia

2016-06-01

Migration of nanomaterials from food containers into food is a matter of concern because of the potential risk for exposed consumers. The aims of this study were to evaluate silver migration from a commercially available food packaging containing silver nanoparticles into a real food matrix (chicken meat) under plausible domestic storage conditions and to test the contribution of such packaging to limit food spoilage bacteria proliferation. Chemical analysis revealed the absence of silver in chicken meatballs under the experimental conditions in compliance with current European Union legislation, which establishes a maximum level of 0.010 mg kg(-1) for the migration of non-authorised substances through a functional barrier (Commission Regulation (EU) No. 10/2011). On the other hand, microbiological tests (total microbial count, Pseudomonas spp. and Enterobacteriaceae) showed no relevant difference in the tested bacteria levels between meatballs stored in silver-nanoparticle plastic bags or control bags. This study shows the importance of testing food packaging not only to verify potential silver migration as an indicator of potential nanoparticle migration, but also to evaluate the benefits in terms of food preservation so as to avoid unjustified usage of silver nanoparticles and possible negative impacts on the environment.

Ultrastructural localization of succinate dehydrogenase in some bacteria, after treatment with Lubrol W1.

PubMed

Cherepova, N; Spasova, D; Radoevska, S

2001-01-01

The localization of succinate dehydrogenase in some gram-negative and gram-positive bacteria (Salmonella typhimurium, Pseudomonas pseudomallei, Pseudomonas aeruginosa and Listeria monocytogenes) treated with the surface membrane active agent, Lubrol W1, was studied by a cytochemical method combined with electron microscopy.

Comparison of bacteria populations in clean and recycled sand used for bedding in dairy facilities.

PubMed

Kristula, M A; Rogers, W; Hogan, J S; Sabo, M

2005-12-01

Bedding samples were collected twice from commercial dairy free-stall facilities that used recycled sand and clean sand in both the summer and winter. Collection began on the day sand was taken from the pile (d 0) and placed in the free stalls, and continued for 5 to 7 additional days. The number of colonies per gram of bedding of gram-negative bacteria, coliforms, Streptococcus spp., and Klebsiella spp. were estimated for each sand sample as well as amounts of dry and organic matter. Clean sand (CS) and recycled sand (RS) had the same bacterial counts when compared at any sampling time. The mean counts of bacterial populations did vary over the course of the study in both CS and RS. There was a significant increase in bacterial counts from d 0 to d 1 for gram-negative bacteria, coliforms, and Streptococcus spp. in both winter and summer. Counts of gram-negative bacteria, coliforms, Klebsiella spp., and Streptococcus spp. did not differ from d 1 to 7 in the winter. Total counts of gram-negative bacteria did not differ from d 1 to 7 in the summer. On d 1 in the summer, coliform counts were lower than at d 5 to 7, and Klebsiella spp. counts were lower than on d 3 to 7. Streptococcus spp. counts were high on d 1 and were constant through d 7 in both winter and summer trials. The number of coliform and Klebsiella spp. in both CS and RS was below the threshold thought to cause mastitis during the sampling times. The number of Streptococcus spp. was high in both CS and RS during the sampling periods. Other management factors need to be identified to decrease the number of Streptococcus spp. in bedding. Recycled sand had a higher organic matter and lower dry matter compared with CS in winter and summer. The results for this study were obtained from multiple herd comparisons, and herd was a significant effect suggesting that different management systems influence the number and types of bacteria in both CS and RS.

Removal of phenanthrene from soil by co-cultures of bacteria and fungi pregrown on sugarcane bagasse pith.

PubMed

Chávez-Gómez, B; Quintero, R; Esparza-García, F; Mesta-Howard, A M; Zavala Díaz de la Serna, F J; Hernández-Rodríguez, C H; Gillén, T; Poggi-Varaldo, H M; Barrera-Cortés, J; Rodríguez-Vázquez, R

2003-09-01

Sixteen co-cultures composed of four bacteria and four fungi grown on sugarcane bagasse pith were tested for phenanthrene degradation in soil. The four bacteria were identified as Pseudomonas aeruginose, Ralstonia pickettii, Pseudomonas sp. and Pseudomonas cepacea. The four fungi were identified as: Penicillium sp., Trichoderma viride, Alternaria tenuis and Aspergillus terrus that were previously isolated from different hydrocarbon-contaminated soils. Fungi had a statistically significant positive (0.0001bacteria removed the compound by an order of 20%. Co-cultures B. cepacea-Penicillium sp., R. pickettii-Penicillium sp., and P. aeruginose-Penicillium sp. exhibited synergism for phenanthrene removal, reaching 72.84+/-3.85%, 73.61+/-6.38% and 69.47+/-4.91%; in 18 days, respectively.

Synergistic Activity of Colistin and Ceftazidime against Multiantibiotic-Resistant Pseudomonas aeruginosa in an In Vitro Pharmacodynamic Model

PubMed Central

Gunderson, Brent W.; Ibrahim, Khalid H.; Hovde, Laurie B.; Fromm, Timothy L.; Reed, Michael D.; Rotschafer, John C.

2003-01-01

Despite the marketing of a series of new antibiotics for antibiotic-resistant gram-positive bacteria, no new agents for multiple-antibiotic-resistant gram-negative infections will be available for quite some time. Clinicians will need to find more effective ways to utilize available agents. Colistin is an older but novel antibiotic that fell into disfavor with clinicians some time ago yet still retains a very favorable antibacterial spectrum, especially for Pseudomonas and Acinetobacter spp. Time-kill curves for two strains of multiantibiotic-resistant Pseudomonas aeruginosa were generated after exposure to colistin alone or in combination with ceftazidime or ciprofloxacin in an in vitro pharmacodynamic model. MICs of colistin, ceftazidime, ciprofloxacin, piperacillin-tazobactam, imipenem, and tobramycin were 0.125, ≥32, >4, >128/4, 16, and >16 mg/liter, respectively. Colistin showed rapid, apparently concentration-dependent bactericidal activity at concentrations between 3 and 200 mg/liter. We were unable to detect increased colistin activity at concentrations above 18 mg/liter due to extremely rapid killing. The combination of colistin and ceftazidime was synergistic (defined as at least a 2-log10 drop in CFU per milliliter from the count obtained with the more active agent) at 24 h. Adding ciprofloxacin to colistin did not enhance antibiotic activity. These data suggest that the antibacterial effect of colistin combined with ceftazidime can be maximized at a peak concentration of ≤18 mg/liter. PMID:12604520

Combined Field Inoculations of Pseudomonas Bacteria, Arbuscular Mycorrhizal Fungi, and Entomopathogenic Nematodes and their Effects on Wheat Performance

PubMed Central

Imperiali, Nicola; Chiriboga, Xavier; Schlaeppi, Klaus; Fesselet, Marie; Villacrés, Daniela; Jaffuel, Geoffrey; Bender, S. Franz; Dennert, Francesca; Blanco-Pérez, Ruben; van der Heijden, Marcel G. A.; Maurhofer, Monika; Mascher, Fabio; Turlings, Ted C. J.; Keel, Christoph J.; Campos-Herrera, Raquel

2017-01-01

In agricultural ecosystems, pest insects, pathogens, and reduced soil fertility pose major challenges to crop productivity and are responsible for significant yield losses worldwide. Management of belowground pests and diseases remains particularly challenging due to the complex nature of the soil and the limited reach of conventional agrochemicals. Boosting the presence of beneficial rhizosphere organisms is a potentially sustainable alternative and may help to optimize crop health and productivity. Field application of single beneficial soil organisms has shown satisfactory results under optimal conditions. This might be further enhanced by combining multiple beneficial soil organisms, but this remains poorly investigated. Here, we inoculated wheat plots with combinations of three beneficial soil organisms that have different rhizosphere functions and studied their effects on crop performance. Plant beneficial Pseudomonas bacteria, arbuscular mycorrhizal fungi (AMF), and entomopathogenic nematodes (EPN), were inoculated individually or in combinations at seeding, and their effects on plant performance were evaluated throughout the season. We used traditional and molecular identification tools to monitor their persistence over the cropping season in augmented and control treatments, and to estimate the possible displacement of native populations. In three separate trials, beneficial soil organisms were successfully introduced into the native populations and readily survived the field conditions. Various Pseudomonas, mycorrhiza, and nematode treatments improved plant health and productivity, while their combinations provided no significant additive or synergistic benefits compared to when applied alone. EPN application temporarily displaced some of the native EPN, but had no significant long-term effect on the associated food web. The strongest positive effect on wheat survival was observed for Pseudomonas and AMF during a season with heavy natural infestation by

Combined Field Inoculations of Pseudomonas Bacteria, Arbuscular Mycorrhizal Fungi, and Entomopathogenic Nematodes and their Effects on Wheat Performance.

PubMed

Imperiali, Nicola; Chiriboga, Xavier; Schlaeppi, Klaus; Fesselet, Marie; Villacrés, Daniela; Jaffuel, Geoffrey; Bender, S Franz; Dennert, Francesca; Blanco-Pérez, Ruben; van der Heijden, Marcel G A; Maurhofer, Monika; Mascher, Fabio; Turlings, Ted C J; Keel, Christoph J; Campos-Herrera, Raquel

2017-01-01

In agricultural ecosystems, pest insects, pathogens, and reduced soil fertility pose major challenges to crop productivity and are responsible for significant yield losses worldwide. Management of belowground pests and diseases remains particularly challenging due to the complex nature of the soil and the limited reach of conventional agrochemicals. Boosting the presence of beneficial rhizosphere organisms is a potentially sustainable alternative and may help to optimize crop health and productivity. Field application of single beneficial soil organisms has shown satisfactory results under optimal conditions. This might be further enhanced by combining multiple beneficial soil organisms, but this remains poorly investigated. Here, we inoculated wheat plots with combinations of three beneficial soil organisms that have different rhizosphere functions and studied their effects on crop performance. Plant beneficial Pseudomonas bacteria, arbuscular mycorrhizal fungi (AMF), and entomopathogenic nematodes (EPN), were inoculated individually or in combinations at seeding, and their effects on plant performance were evaluated throughout the season. We used traditional and molecular identification tools to monitor their persistence over the cropping season in augmented and control treatments, and to estimate the possible displacement of native populations. In three separate trials, beneficial soil organisms were successfully introduced into the native populations and readily survived the field conditions. Various Pseudomonas , mycorrhiza, and nematode treatments improved plant health and productivity, while their combinations provided no significant additive or synergistic benefits compared to when applied alone. EPN application temporarily displaced some of the native EPN, but had no significant long-term effect on the associated food web. The strongest positive effect on wheat survival was observed for Pseudomonas and AMF during a season with heavy natural infestation by

Characterization of the dominant bacterial communities during storage of Norway lobster and Norway lobster tails (Nephrops norvegicus) based on 16S rDNA analysis by PCR-DGGE.

PubMed

Bekaert, Karen; Devriese, Lisa; Maes, Sara; Robbens, Johan

2015-04-01

The aim of this study was to investigate the microbial quality of whole Norway lobster (Nephrops norvegicus) and Norway lobster tails to optimize handling conditions. This was done by assessing the total viable count (TVC) and characterizing the dominant microbiota. The cultivable microorganisms were quantified via classical microbiological plating methods. To characterize as many bacterial species present as possible, we performed advanced molecular identification techniques (PCR-DGGE). The initial TVC of fresh Norway lobster meat was high (3.0 log cfu/g) as compared to fish. No significant difference between whole Norway lobster and Norway lobster tails could be found during the storage period. From day 6 of storage, a significant difference between Plate Count Agar (PCA) and Marine Agar (MA) was observed. The microbiota of Norway lobster was dominated by members of the Gram-negative genera such as Psychrobacter spp., Pseudoalteromonas spp., Pseudomonas spp., Luteimonas spp., and Aliivibrio spp. From these bacteria, mainly Psychrobacter spp. and Pseudomonas spp. remained present until the end of the storage period. These are known spoilage organisms in fishery products. Other known spoilage organisms of crustaceans such as Photobacterium spp. could not be identified. Copyright © 2014 Elsevier Ltd. All rights reserved.

Distribution of Indigenous Bacterial Pathogens and Potential Pathogens Associated with Roof-Harvested Rainwater

PubMed Central

Dobrowsky, P. H.; De Kwaadsteniet, M.; Cloete, T. E.

2014-01-01

The harvesting of rainwater is gaining acceptance among many governmental authorities in countries such as Australia, Germany, and South Africa, among others. However, conflicting reports on the microbial quality of harvested rainwater have been published. To monitor the presence of potential pathogenic bacteria during high-rainfall periods, rainwater from 29 rainwater tanks was sampled on four occasions (during June and August 2012) in a sustainable housing project in Kleinmond, South Africa. This resulted in the collection of 116 harvested rainwater samples in total throughout the sampling period. The identities of the dominant, indigenous, presumptive pathogenic isolates obtained from the rainwater samples throughout the sampling period were confirmed through universal 16S rRNA PCR, and the results revealed that Pseudomonas (19% of samples) was the dominant genus isolated, followed by Aeromonas (16%), Klebsiella (11%), and Enterobacter (9%). PCR assays employing genus-specific primers also confirmed the presence of Aeromonas spp. (16%), Klebsiella spp. (47%), Legionella spp. (73%), Pseudomonas spp. (13%), Salmonella spp. (6%), Shigella spp. (27%), and Yersinia spp. (28%) in the harvested rainwater samples. In addition, on one sampling occasion, Giardia spp. were detected in 25% of the eight tank water samples analyzed. This study highlights the diverse array of pathogenic bacteria that persist in harvested rainwater during high-rainfall periods. The consumption of untreated harvested rainwater could thus pose a potential significant health threat to consumers, especially children and immunocompromised individuals, and it is recommended that harvested rainwater be treated for safe usage as an alternative water source. PMID:24487540

Reduction of ferric iron by acidophilic heterotrophic bacteria: evidence for constitutive and inducible enzyme systems in Acidiphilium spp.

PubMed

Johnson, D B; Bridge, T A M

2002-01-01

To compare the abilities of two obligately acidophilic heterotrophic bacteria, Acidiphilium acidophilum and Acidiphilium SJH, to reduce ferric iron to ferrous when grown under different culture conditions. Bacteria were grown in batch culture, under different aeration status, and in the presence of either ferrous or ferric iron. The specific rates of ferric iron reduction by fermenter-grown Acidiphilium SJH were unaffected by dissolved oxygen (DO) concentrations, while iron reduction by A. acidophilum was highly dependent on DO concentrations in the growth media. The ionic form of iron present (ferrous or ferric) had a minimal effect on the abilities of harvested cells to reduce ferric iron. Whole cell protein profiles of Acidiphilium SJH were very similar, regardless of the DO status of the growth medium, while additional proteins were present in A. acidophilum grown microaerobically compared with aerobically-grown cells. The dissimilatory reduction of ferric iron is constitutive in Acidiphilium SJH while it is inducible in A. acidophilum. Ferric iron reduction by Acidiphilium spp. may occur in oxygen-containing as well as anoxic acidic environments. This will detract from the effectiveness of bioremediation systems where removal of iron from polluted waters is mediated via oxidation and precipitation of the metal.

Nosocomial outbreak of Pseudomonas aeruginosa endophthalmitis.

PubMed

Mateos, I; Valencia, R; Torres, M J; Cantos, A; Conde, M; Aznar, J

2006-11-01

We describe an outbreak of nosocomial endophthalmitis due to a common source, which was determined to be trypan blue solution prepared in the hospital's pharmacy service. We assume that viable bacteria probably gained access to the trypan blue stock solution during cooling after autoclaving. The temporal cluster of Pseudomonas aeruginosa endophthalmitis was readily perceived on the basis of clinical and microbiological findings, and an exogenous source of contamination was unequivocally identified by means of DNA fingerprinting.

Magnetic nanoparticle-mediated isolation of functional bacteria in a complex microbial community

PubMed Central

Zhang, Dayi; Berry, James P; Zhu, Di; Wang, Yun; Chen, Yin; Jiang, Bo; Huang, Shi; Langford, Harry; Li, Guanghe; Davison, Paul A; Xu, Jian; Aries, Eric; Huang, Wei E

2015-01-01

Although uncultured microorganisms have important roles in ecosystems, their ecophysiology in situ remains elusive owing to the difficulty of obtaining live cells from their natural habitats. In this study, we employed a novel magnetic nanoparticle-mediated isolation (MMI) method to recover metabolically active cells of a group of previously uncultured phenol degraders, Burkholderiales spp., from coking plant wastewater biosludge; five other culturable phenol degraders—Rhodococcus sp., Chryseobacterium sp. and three different Pseudomonas spp.—were also isolated from the same biosludge using traditional methods. The kinetics of phenol degradation by MMI-recovered cells (MRCs) was similar to that of the original sludge. Stable isotope probing (SIP) and pyrosequencing of the 16S rRNA from the ‘heavy' DNA (13C-DNA) fractions indicated that Burkholderiales spp. were the key phenol degraders in situ in the biosludge, consistent with the results of MRCs. Single-cell Raman micro-spectroscopy was applied to probe individual bacteria in the MRCs obtained from the SIP experiment and showed that 79% of them were fully 13C-labelled. Biolog assays on the MRCs revealed the impact of various carbon and nitrogen substrates on the efficiency of phenol degradation in the wastewater treatment plant biosludge. Specifically, hydroxylamine, a metabolite of ammonia oxidisation, but not nitrite, nitrate or ammonia, inhibited phenol degradation in the biosludge. Our results provided a novel insight into the occasional abrupt failure events that occur in the wastewater treatment plant. This study demonstrated that MMI is a powerful tool to recover live and functional cells in situ from a complex microbial community to enable further characterisation of their physiology. PMID:25191996

Bad bacteria in acute appendicitis: rare but relevant.

PubMed

Reinisch, Alexander; Malkomes, Patrizia; Habbe, Nils; Bechstein, Wolf Otto; Liese, Juliane

2017-09-01

Bacterial infections are a factor for morbidity in patients with acute appendicitis (AA). The spreading of multidrug-resistant (MDR) bacteria is a significant problem in surgery, and the most relevant MDR pathogens are summarized as Enterobacteriaceae, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterococci (ESKAPE) bacteria. Data regarding the species and distribution of bacteria in AA are available, but information about the resistances and their relevance is deficient. In this retrospective study, we analyzed microbiological swabs of patients with AA. The outcome parameters of patients after laparoscopic appendectomy were analyzed against microbiological results, including antibiotic resistance testing. Positive swabs were compared with bacteria cultivated after alternative abdominal emergency surgery (AES). In total, 584 patients with AA were included and had a mean age of 35.5 years. In 216 patients (36.9%), a swab was taken, and in 128 (59.3%) swabs, bacteria could be cultivated. The most frequent organisms were Escherichia coli, Bacteroides species, and Pseudomonas. In 9.4% of the positive AA swabs, MDR germs were cultivated, and all of them were ESKAPE pathogens. Patients with MDR bacteria in AA suffered more infectious complications (p = 0.006) and needed longer hospitalizations (p < 0.009). In AES, aside from appendicitis, a different spectrum containing more MDR bacteria was cultivated (5.9 vs. 20.9%; p < 0.0001). Although they occur less frequently in appendectomy compared to emergency surgeries for other abdominal diseases, MDR bacteria are traceable in this common disease and contribute to additional morbidity.

Identification and Quantification of Volatile Chemical Spoilage Indexes Associated with Bacterial Growth Dynamics in Aerobically Stored Chicken.

PubMed

Mikš-Krajnik, Marta; Yoon, Yong-Jin; Ukuku, Dike O; Yuk, Hyun-Gyun

2016-08-01

Volatile organic compounds (VOCs) as chemical spoilage indexes (CSIs) of raw chicken breast stored aerobically at 4, 10, and 21 °C were identified and quantified using solid phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS). The growth dynamics of total viable count (TVC), psychrotrophs, Pseudomonas spp., lactic acid bacteria (LAB), Brochothrix thermosphacta and H2 S producing bacteria were characterized based on maximum growth rates (μmax ), maximal microbial concentration (Nmax ) and at the moment of microbial shelf life (Svalues ), calculated from Gompertz-fitted growth curves. Pseudomonas spp. was predominant species, while B. thermosphacta was characterized by the highest μmax . The microbiological and sensory shelf lives were estimated based on TVC, Pseudomonas spp., and B. thermosphacta counts and sensory evaluation, respectively. Among 27 VOCs identified by GC-MS in spoiled chicken samples, ethanol (EtOH), 1-butanol-3-methyl (1But-3M), and acetic acid (C2 ) achieved the highest Pearson's correlation coefficients of 0.66, 0.61, and 0.59, respectively, with TVC, regardless of storage temperature. Partial least squares (PLS) regression revealed that the synthesis of 1But-3M and C2 was most likely induced by the metabolic activity of B. thermosphacta and LAB, while EtOH was attributed to Pseudomonas spp. The increase in concentration of selected volatile spoilage markers (EtOH, 1But-3M, and C2 ) in the headspace over spoiled chicken breast was found to be statistically significant (P < 0.05) with TVC growth. These findings highlight the possibility of analyzing the combination of 3 selected spoilage markers: EtOH, 1But-3M, and C2 as rapid evaluation for poultry quality testing using SPME-GC-MS. © 2016 Institute of Food Technologists®

Structure and biophysics of type III secretion in bacteria.

PubMed

Chatterjee, Srirupa; Chaudhury, Sukanya; McShan, Andrew C; Kaur, Kawaljit; De Guzman, Roberto N

2013-04-16

Many plant and animal bacterial pathogens assemble a needle-like nanomachine, the type III secretion system (T3SS), to inject virulence proteins directly into eukaryotic cells to initiate infection. The ability of bacteria to inject effectors into host cells is essential for infection, survival, and pathogenesis for many Gram-negative bacteria, including Salmonella, Escherichia, Shigella, Yersinia, Pseudomonas, and Chlamydia spp. These pathogens are responsible for a wide variety of diseases, such as typhoid fever, large-scale food-borne illnesses, dysentery, bubonic plague, secondary hospital infections, and sexually transmitted diseases. The T3SS consists of structural and nonstructural proteins. The structural proteins assemble the needle apparatus, which consists of a membrane-embedded basal structure, an external needle that protrudes from the bacterial surface, and a tip complex that caps the needle. Upon host cell contact, a translocon is assembled between the needle tip complex and the host cell, serving as a gateway for translocation of effector proteins by creating a pore in the host cell membrane. Following delivery into the host cytoplasm, effectors initiate and maintain infection by manipulating host cell biology, such as cell signaling, secretory trafficking, cytoskeletal dynamics, and the inflammatory response. Finally, chaperones serve as regulators of secretion by sequestering effectors and some structural proteins within the bacterial cytoplasm. This review will focus on the latest developments and future challenges concerning the structure and biophysics of the needle apparatus.

Triclosan- resistant bacteria isolated from feedlot and residential soils

PubMed Central

WELSCH, TANNER T.; GILLOCK, ERIC T.

2014-01-01

Triclosan is an antimicrobial agent that is currently incorporated into hundreds of consumer and medical products. It can be either a bacteriostatic or bactericidal agent, depending on its formulation. It has activity against Gram-positive and Gram-negative bacteria, as well as some viruses and protists. The purpose of this study was to determine whether triclosan-resistant bacteria could be isolated from the soil. Soils from cattle feedlots and residential lawns were collected and assayed for the presence of these organisms by plating samples on growth media containing triclosan. Organisms were subsequently identified by partial 16S rRNA sequencing analysis. All the organisms isolated in this study were Gram-negative rods, with members of genus Pseudomonas being particularly well represented. This result may not be surprising because Gram-negative organisms are generally more resistant to triclosan, and since Pseudomonas bacteria are known to have numerous efflux mechanisms for dealing with harmful substances. PMID:21391038

DAPG-producing Pseudomonas fluorescens: beneficial agents for suppression of plant-parasitic nematodes?

USDA-ARS?s Scientific Manuscript database

Some beneficial strains of the bacterium Pseudomonas fluorescens produce the antibiotic 2, 4-diacetylphloroglucinol (DAPG). DAPG is active against a number of organisms, including viruses, bacteria, fungi and plants, and DAPG-producing P. fluorescens can also induce plant resistance against pathogen...

Engineering the Soil Bacterium Pseudomonas putida for Arsenic Methylation

PubMed Central

Chen, Jian; Qin, Jie; Zhu, Yong-Guan; de Lorenzo, Víctor

2013-01-01

Accumulation of arsenic has potential health risks through consumption of food. Here, we inserted the arsenite [As(III)] S-adenosylmethionine methyltransferase (ArsM) gene into the chromosome of Pseudomonas putida KT2440. Recombinant bacteria methylate inorganic arsenic into less toxic organoarsenicals. This has the potential for bioremediation of environmental arsenic and reducing arsenic contamination in food. PMID:23645194

Candida spp. in periodontal disease: a brief review.

PubMed

Sardi, Janaina C O; Duque, Cristiane; Mariano, Flávia S; Peixoto, Iza T A; Höfling, José F; Gonçalves, Reginaldo B

2010-06-01

Although the main reservoir of Candida spp. is believed to be the buccal mucosa, these microorganisms can coaggregate with bacteria in subgingival biofilm and adhere to epithelial cells. Such interactions are associated with the capacity of Candida spp. to invade gingival conjunctive tissue, and may be important in the microbial colonization that contributes to progression of oral alterations caused by diabetes mellitus, some medications, and immunosuppressive diseases such as AIDS. In addition, immune deficiency can result in proliferation of Candida spp. and germination of forms that are more virulent and have a higher capacity to adhere to and penetrate cells in host tissues. The virulence factors of Candida spp. increase host susceptibility to proliferation of these microorganisms and are likely to be important in the study of periodontal disease. Herein, we briefly review the literature pertaining to the role of Candida spp. in periodontal disease, and consider the main virulence factors, the host immune response to these microorganisms, and the effect of concomitant immunosuppressive conditions.

Antibacterial activity of silver-killed bacteria: the "zombies" effect

NASA Astrophysics Data System (ADS)

Wakshlak, Racheli Ben-Knaz; Pedahzur, Rami; Avnir, David

2015-04-01

We report a previously unrecognized mechanism for the prolonged action of biocidal agents, which we denote as the zombies effect: biocidally-killed bacteria are capable of killing living bacteria. The concept is demonstrated by first killing Pseudomonas aeruginosa PAO1 with silver nitrate and then challenging, with the dead bacteria, a viable culture of the same bacterium: Efficient antibacterial activity of the killed bacteria is observed. A mechanism is suggested in terms of the action of the dead bacteria as a reservoir of silver, which, due to Le-Chatelier's principle, is re-targeted to the living bacteria. Langmuirian behavior, as well as deviations from it, support the proposed mechanism.

Protein Chips for Detection of Salmonella spp. from Enrichment Culture

PubMed Central

Poltronieri, Palmiro; Cimaglia, Fabio; De Lorenzis, Enrico; Chiesa, Maurizio; Mezzolla, Valeria; Reca, Ida Barbara

2016-01-01

Food pathogens are the cause of foodborne epidemics, therefore there is a need to detect the pathogens in food productions rapidly. A pre-enrichment culture followed by selective agar plating are standard detection methods. Molecular methods such as qPCR have provided a first rapid protocol for detection of pathogens within 24 h of enrichment culture. Biosensors also may provide a rapid tool to individuate a source of Salmonella contamination at early times of pre-enrichment culture. Forty mL of Salmonella spp. enrichment culture were processed by immunoseparation using the Pathatrix, as in AFNOR validated qPCR protocols. The Salmonella biosensor combined with immunoseparation showed a limit of detection of 100 bacteria/40 mL, with a 400 fold increase to previous results. qPCR analysis requires processing of bead-bound bacteria with lysis buffer and DNA clean up, with a limit of detection of 2 cfu/50 μL. Finally, a protein chip was developed and tested in screening and identification of 5 common pathogen species, Salmonella spp., E. coli, S. aureus, Campylobacter spp. and Listeria spp. The protein chip, with high specificity in species identification, is proposed to be integrated into a Lab-on-Chip system, for rapid and reproducible screening of Salmonella spp. and other pathogen species contaminating food productions. PMID:27110786

Diversity of Bacteria Carried by Pinewood Nematode in USA and Phylogenetic Comparison with Isolates from Other Countries

PubMed Central

Proença, Diogo Neves; Fonseca, Luís; Powers, Thomas O.; Abrantes, Isabel M. O.; Morais, Paula V.

2014-01-01

Pine wilt disease (PWD) is native to North America and has spread to Asia and Europe. Lately, mutualistic relationship has been suggested between the pinewood nematode (PWN), Bursaphelenchus xylophilus the causal nematode agent of PWD, and bacteria. In countries where PWN occurs, nematodes from diseased trees were reported to carry bacteria from several genera. However no data exists for the United States. The objective of this study was to evaluate the diversity of the bacterial community carried by B. xylophilus, isolated from different Pinus spp. with PWD in Nebraska, United States. The bacteria carried by PWN belonged to Gammaproteobacteria (79.9%), Betaproteobacteria (11.7%), Bacilli (5.0%), Alphaproteobacteria (1.7%) and Flavobacteriia (1.7%). Strains from the genera Chryseobacterium and Pigmentiphaga were found associated with the nematode for the first time. These results were compared to results from similar studies conducted from other countries of three continents in order to assess the diversity of bacteria with associated with PWN. The isolates from the United States, Portugal and China belonged to 25 different genera and only strains from the genus Pseudomonas were found in nematodes from all countries. The strains from China were closely related to P. fluorescens and the strains isolated from Portugal and USA were phylogenetically related to P. mohnii and P. lutea. Nematodes from the different countries are associated with bacteria of different species, not supporting a relationship between PWN with a particular bacterial species. Moreover, the diversity of the bacteria carried by the pinewood nematode seems to be related to the geographic area and the Pinus species. The roles these bacteria play within the pine trees or when associated with the nematodes, might be independent of the presence of the nematode in the tree and only related on the bacteria's relationship with the tree. PMID:25127255

Bioaugmentation of oil reservoir indigenous Pseudomonas aeruginosa to enhance oil recovery through in-situ biosurfactant production without air injection.

PubMed

Zhao, Feng; Li, Ping; Guo, Chao; Shi, Rong-Jiu; Zhang, Ying

2018-03-01

Considering the anoxic conditions within oil reservoirs, a new microbial enhanced oil recovery (MEOR) technology through in-situ biosurfactant production without air injection was proposed. High-throughput sequencing data revealed that Pseudomonas was one of dominant genera in Daqing oil reservoirs. Pseudomonas aeruginosa DQ3 which can anaerobically produce biosurfactant at 42 °C was isolated. Strain DQ3 was bioaugmented in an anaerobic bioreactor to approximately simulate MEOR process. During bioaugmentation process, although a new bacterial community was gradually formed, Pseudomonas was still one of dominant genera. Culture-based data showed that hydrocarbon-degrading bacteria and biosurfactant-producing bacteria were activated, while sulfate reducing bacteria were controlled. Biosurfactant was produced at simulated reservoir conditions, decreasing surface tension to 33.8 mN/m and emulsifying crude oil with EI 24  = 58%. Core flooding tests revealed that extra 5.22% of oil was displaced by in-situ biosurfactant production. Bioaugmenting indigenous biosurfactant producer P. aeruginosa without air injection is promising for in-situ MEOR applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimental Keratitis Due to Pseudomonas aeruginosa: Model for Evaluation of Antimicrobial Drugs

PubMed Central

Davis, Starkey D.; Chandler, John W.

1975-01-01

An improved method for experimental keratitis due to Pseudomonas aeruginosa is described. Essential features of the method are use of inbred guinea pigs, intracorneal injection of bacteria, subconjunctival injection of antibiotics, “blind” evaluation of results, and statistical analysis of data. Untreated ocular infections were most severe 5 to 7 days after infection. Sterilized bacterial suspensions caused no abnormalities on day 5. Tobramycin and polymyxin B were more active than gentamicin against two strains of Pseudomonas. This model is suitable for many types of quantitative studies on experimental keratitis. Images PMID:810084

Electrophoretic analysis of cyanide depletion by Pseudomonas alcaligenes.

PubMed

Zaugg, S E; Davidson, R A; Walker, J C; Walker, E B

1997-02-01

Bacterial-facilitated depletion of cyanide is under development for remediation of heap leach operations in the gold mining industry. Capillary electrophoresis was found to be a powerful tool for quantifying cyanide depletion. Changes in cyanide concentration in aqueous suspensions of Pseudomonas alcaligenes bacteria and cyanide at elevated pH were easily monitored by capillary electrophoresis. The resulting data can be used to study rates of cyanide depletion by this strain of bacteria. Concentrations of these bacteria at 10(5) cells/mL were found to reduce cyanide from 100 ppm to less than 8 ppm in four days. In addition, other ions of interest in cyanide metabolism, such as formate, can be simultaneously analyzed. Direct UV detection of cyanide at 192 nm further simplifies the analytical method for these ions.

Comparative analysis of the bacterial flora of vegetables collected directly from farms and from supermarkets in Germany.

PubMed

Schwaiger, Karin; Helmke, Katharina; Holzel, Christina Susanne; Bauer, Johann

2011-06-01

A total of 1,001 vegetables were collected from 13 farms and 11 supermarkets in Bavaria, Germany; 722 samples were positive for coliforms (mostly Enterobacter cloacae; n = 176). Escherichia coli were detected in 34, Pseudomonas spp. in 439, Salmonella spp. in 1, Enterococcus spp. in 682, and Listeria spp. in 11 samples. Prevalence of all investigated genera tended to be lower in samples collected at the supermarket. However, prevalence of Pseudomonas fluorescens was higher in supermarket samples. Cereals/bulbous vegetables were less contaminated than root vegetables/salads. Fruit vegetables seem to be often subsequently contaminated in the retail market. Compared to foods of animal origin, prevalence of pathogenic bacteria is low. Particularly, in 1,001 investigated vegetables, only four L. monocytogenes and one Salmonella enterica have been found. Almost all of the detected microorganisms are reported to be opportunistic pathogens, if only in rare cases. Therefore, fresh produce should be washed or peeled before it is eaten raw.

Biotransformation of geosmin by terpene-degrading bacteria.

USDA-ARS?s Scientific Manuscript database

Two terpene-degrading bacteria that are able to transform geosmin have been identified. Pseudomonas sp. SBR3-tpnb, isolated on -terpinene, converts geosmin to several products; the major products are keto-geosmins. This geosmin transformation ability is inducible by -terpinene. Rhodococcus wratisl...

Pasteuria spp.: Systematics and Phylogeny of These Bacterial Parasites of Phytopathogenic Nematodes.

PubMed

Preston, J F; Dickson, D W; Maruniak, J E; Nong, G; Brito, J A; Schmidt, L M; Giblin-Davis, R M

2003-06-01

Pasteuria spp. include endospore-forming bacterial pathogens of cladoceran crustaceans and plant-parasitic nematodes. Propagation of these nematode pathogens requires attachment of soilborne endospores to nematode hosts, infection, growth, sporulation, and release of endospores to repeat the cycle of infection and propagation. The ability of these bacteria to suppress the levels of plant-parasitic nematodes in the field has made them particularly promising candidates for biocontrol of nematode diseases of plants. Genes encoding 16S ribosomal RNA have been sequenced for the cladoceran (water flea) parasite and type species, Pasteuria ramosa, and for Pasteuria spp. isolated from root-knot (Meloidogyne arenaria race 1 and Meloidogyne sp.), soybean cyst (Heterodera glycines), and sting (Belonolaimus longicaudatus) nematodes. These have provided a phylogenetic basis for their designation to a distinct clade within the family Alicyclobacillaceae of the gram-positive endospore-forming bacteria. Two apparent biotypes of P. penetrans demonstrating a host preference for different Meloidogyne spp. showed identical 16S rDNA sequences, suggesting host-recognition evolves within a given species. The sequences of genes encoding sporulation transcription factors, sigE and sigF, from P. penetrans biotype P-20 show different phylogenetic relationships to other endospore-forming bacteria, supporting their application to further discriminate Pasteuria spp. and biotypes. Distribution of an adhesin-associated epitope on polypeptides from different Pasteuria isolates provides an immunochemical approach to differentiate species and biotypes with specific host preferences. Application of bioinformatics to genomic data, as well as further characterization of the biochemical basis for host recognition, will facilitate development of Pasteuria spp. as benign alternatives to chemical nematicides.

Biofilms and antibiotic susceptibility of multidrug-resistant bacteria from wild animals.

PubMed

Dias, Carla; Borges, Anabela; Oliveira, Diana; Martinez-Murcia, Antonio; Saavedra, Maria José; Simões, Manuel

2018-01-01

The "One Health" concept recognizes that human health and animal health are interdependent and bound to the health of the ecosystem in which they (co)exist. This interconnection favors the transmission of bacteria and other infectious agents as well as the flow of genetic elements containing antibiotic resistance genes. This problem is worsened when pathogenic bacteria have the ability to establish as biofilms. Therefore, it is important to understand the characteristics and behaviour of microorganisms in both planktonic and biofilms states from the most diverse environmental niches to mitigate the emergence and dissemination of resistance. The purpose of this work was to assess the antibiotic susceptibility of four bacteria ( Acinetobacter spp., Klebsiella pneumoniae , Pseudomonas fluorescens and Shewanella putrefaciens ) isolated from wild animals and their ability to form biofilms. The effect of two antibiotics, imipenem (IPM) and ciprofloxacin (CIP), on biofilm removal was also assessed. Screening of resistance genetic determinants was performed by PCR. Biofilm tests were performed by a modified microtiter plate method. Bacterial surface hydrophobicity was determined by sessile drop contact angles. The susceptibility profile classified the bacteria as multidrug-resistant. Three genes coding for β-lactamases were detected in K. pneumoniae (TEM, SHV, OXA-aer) and one in P. fluorescens (OXA-aer). K. pneumoniae was the microorganism that carried more β-lactamase genes and it was the most proficient biofilm producer, while P. fluorescens demonstrated the highest adhesion ability. Antibiotics at their MIC, 5 × MIC and 10 × MIC were ineffective in total biofilm removal. The highest biomass reductions were found with IPM (54% at 10 × MIC) against K. pneumoniae biofilms and with CIP (40% at 10 × MIC) against P. fluorescens biofilms. The results highlight wildlife as important host reservoirs and vectors for the spread of multidrug-resistant bacteria and genetic

Biofilms and antibiotic susceptibility of multidrug-resistant bacteria from wild animals

PubMed Central

Dias, Carla; Borges, Anabela; Oliveira, Diana; Martinez-Murcia, Antonio; Saavedra, Maria José

2018-01-01

Background The “One Health” concept recognizes that human health and animal health are interdependent and bound to the health of the ecosystem in which they (co)exist. This interconnection favors the transmission of bacteria and other infectious agents as well as the flow of genetic elements containing antibiotic resistance genes. This problem is worsened when pathogenic bacteria have the ability to establish as biofilms. Therefore, it is important to understand the characteristics and behaviour of microorganisms in both planktonic and biofilms states from the most diverse environmental niches to mitigate the emergence and dissemination of resistance. Methods The purpose of this work was to assess the antibiotic susceptibility of four bacteria (Acinetobacter spp., Klebsiella pneumoniae, Pseudomonas fluorescens and Shewanella putrefaciens) isolated from wild animals and their ability to form biofilms. The effect of two antibiotics, imipenem (IPM) and ciprofloxacin (CIP), on biofilm removal was also assessed. Screening of resistance genetic determinants was performed by PCR. Biofilm tests were performed by a modified microtiter plate method. Bacterial surface hydrophobicity was determined by sessile drop contact angles. Results The susceptibility profile classified the bacteria as multidrug-resistant. Three genes coding for β-lactamases were detected in K. pneumoniae (TEM, SHV, OXA-aer) and one in P. fluorescens (OXA-aer). K. pneumoniae was the microorganism that carried more β-lactamase genes and it was the most proficient biofilm producer, while P. fluorescens demonstrated the highest adhesion ability. Antibiotics at their MIC, 5 × MIC and 10 × MIC were ineffective in total biofilm removal. The highest biomass reductions were found with IPM (54% at 10 × MIC) against K. pneumoniae biofilms and with CIP (40% at 10 × MIC) against P. fluorescens biofilms. Discussion The results highlight wildlife as important host reservoirs and vectors for the spread of

Exploration of indigenous bacteria in an intensive aquaculture system of African catfish (Clarias sp.) in Banyuwangi, Indonesia

NASA Astrophysics Data System (ADS)

Prayogo; Rahardja, B. S.; Asshanti, A. N.; Dewi, N. N.; Santanumurti, M. B.

2018-04-01

Intensive African catfish culture in tarpaulin pond was popular in Banyuwangi, Indonesia since the government supported the fisheries sector. Unfortunately, the failure of African catfish culture still occurred since the waste from fish metabolite process and feed residue decreased the water quality. Bacteria in the water could be the solution to increase the success rate of aquaculture by improving the water quality. This study purpose was to obtained indigenous bacteria in intensive aquaculture system of African catfish to improve water quality. This study successfully isolated bacteria contained with amylase, protease and lipase characteristic. Isolated bacteria in this study were identified as Pseudomonas pseudomallei (97.81%), Bacillus subtilis (95.81%) and Pseudomonas stutzeri (61.21%).

[Selective enrichment of Pseudomonas spp. in the rhizoplane of different plant species].

PubMed

Marrero, Mariana A; Agaras, Betina; Wall, Luis G; Valverde, Claudio

2015-01-01

In contrast to rhizobia-legume symbiosis, the specificity for root colonization by pseudomonads seems to be less strict. However, several studies about bacterial diversity in the rhizosphere highlight the influence of plant species on the selective enrichment of certain microorganisms from the bulk soil community. In order to evaluate the effect that different crops have on the structure of pseudomonad community on the root surface, we performed plant trap experiments, using surface-disinfected maize, wheat or soybean seeds that were sown in pots containing the same pristine soil as substrate. Rhizoplane suspensions were plated on a selective medium for Pseudomonas, and pooled colonies served as DNA source to carry out PCR-RFLP community structure analysis of the pseudomonads-specific marker genes oprF and gacA. PCR-RFLP profiles were grouped by plant species, and were distinguished from those of bulk soil samples. Partial sequencing of 16S rDNA genes of some representative colonies of Pseudomonas confirmed the selective enrichment of distinctive genotypes in the rhizoplane of each plant species. These results support the idea that the root systems of agricultural crops such as soybean, maize and wheat, select differential sets of pseudomonads from the native microbial repertoire inhabiting the bulk soil. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Antibiotic susceptibility patterns of different bacteria isolated from patients with ventilator associated pneumonia (vap).

PubMed

Alqurashi, Abdulrahman M

2005-09-01

Ventilator associated pneumonia (VAP) is a frequent complication of mechanical ventilation (MV) and it is a leading cause of death in MV patients. The development of VAP has been demonstrated as being due to aspiration of oropharyngeal secretion, ventilator tubing condensate, or gastric contents that are colonized with pathogenic microorganisms. The aim of the present study is to isolate and identify bacteria that cause VAP and to study antibiotic susceptibility. This study was carried out on 95 patients who fulfilled the diagnostic criteria for VAP. Quantitative cultures of endotracheal aspirates (EA) using a cut-off point of 10(6) cfu/ml was done. The microbiological results revealed that gram negative bacilli were the most common bacterial agents responsible for VAP and accounted for 78.8% of all the causative agents. The most common isolated organisms were Klebsiella pnemouniae (30.9 %) followed by Pseudomonas aeruginosa (22.5%), Staphylococcus aureus (21.2%), Eschericia coli (12.8 %), Proteus spp. (9.8%), and Citrobacter spp. (2.8%). Blood cultures were positive in 25.9% of patients with Klebsiella pnemouniae in about 33.3%. From this study, it can be concluded that VAP is an important nosocomial infection. EA is a simple procedure to obtain respiratory samples and perform sensitivity testing in patients with VAP. Also, the commonest cause of VAP is gram negative bacilli.

Association of Enterococcus spp. with Severe Combat Extremity Injury, Intensive Care, and Polymicrobial Wound Infection.

PubMed

Heitkamp, Rae A; Li, Ping; Mende, Katrin; Demons, Samandra T; Tribble, David R; Tyner, Stuart D

2018-01-01

Combat-related extremity wound infections can complicate the recovery of injured military personnel. The Enterococcus genus contains both commensal and pathogenic bacteria found in many combat wounds. We describe the patient population susceptible to Enterococcus infection, the characteristics of Enterococcus spp. isolated from combat-related wounds, and the microbiological profile of Enterococcus-positive wounds. Patient and culture data were obtained from the Trauma Infectious Disease Outcomes Study. Subjects were divided into a case group with enterococcal extremity wound infections and a comparator group with wound infections caused by other micro-organisms. Case and comparator subjects had similar patterns of injury and infection. Case subjects had higher Injury Severity Scores (33 vs. 30; p < 0.001), longer hospitalization at U.S. facilities (55 vs. 40 days; p = 0.004), and required more large-volume blood transfusions (>20 units) within 24 h post-injury (53% vs. 30%; p < 0.001). Approximately 60% of case subjects had three or more infections, and 91% had one or more polymicrobial infections, compared with 43% and 50%, respectively, in the comparator group. The thigh was the most common site of Enterococcus spp. isolation, contributing 50% of isolates. Enterococcus faecium was the predominant species isolated from case-group infections overall (66%), as well as in polymicrobial infections (74%). Frequent co-colonizing microbes in polymicrobial wound infections with Enterococcus were other ESKAPE pathogens (64%) (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae [and Escherichia coli], Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) and fungi (35%). The specific pathogenicity of Enterococcus relative to other pathogens in polymicrobial wounds is unknown. Identifying strain-specific outcomes and investigating the interactions of Enterococcus strains with other wound pathogens could provide additional tools

Trehalose 6-phosphate phosphatases of Pseudomonas aeruginosa.

PubMed

Cross, Megan; Biberacher, Sonja; Park, Suk-Youl; Rajan, Siji; Korhonen, Pasi; Gasser, Robin B; Kim, Jeong-Sun; Coster, Mark J; Hofmann, Andreas

2018-04-24

The opportunistic bacterium Pseudomonas aeruginosa has been recognized as an important pathogen of clinical relevance and is a leading cause of hospital-acquired infections. The presence of a glycolytic enzyme in Pseudomonas, which is known to be inhibited by trehalose 6-phosphate (T6P) in other organisms, suggests that these bacteria may be vulnerable to the detrimental effects of intracellular T6P accumulation. In the present study, we explored the structural and functional properties of trehalose 6-phosphate phosphatase (TPP) in P. aeruginosa in support of future target-based drug discovery. A survey of genomes revealed the existence of 2 TPP genes with either chromosomal or extrachromosomal location. Both TPPs were produced as recombinant proteins, and characterization of their enzymatic properties confirmed specific, magnesium-dependent catalytic hydrolysis of T6P. The 3-dimensional crystal structure of the chromosomal TPP revealed a protein dimer arising through β-sheet expansion of the individual monomers, which possess the overall fold of halo-acid dehydrogenases.-Cross, M., Biberacher, S., Park, S.-Y., Rajan, S., Korhonen, P., Gasser, R. B., Kim, J.-S., Coster, M. J., Hofmann, A. Trehalose 6-phosphate phosphatases of Pseudomonas aeruginosa.

[Changes in the bacteriological, chemical and organoleptic characteristics of the Antartic krill (Euphausia superba) during storage at 0-2 degrees C].

PubMed

Locati, G A; Espeche, M E; Fraile, E R

1980-01-01

A study was performed on the bacteriological, chemical and organoleptic characteristics of antartic krill (Euphausia superba) stored at 0-2 degrees C. After 6-8 hours of storage a dark color started in the head and legs and spread slowly to the tail. Within 24 hours 17% of the total nitrogen was lost by hepatopancreas autolisis. After 72 hours the krill became inedible due to strong amoniacal odor and flavor. These changes were associated with the multiplication of aerobic psychrophilic bacteria. The bacterial counts of freshly caught krill ranged between 3,7 X 10(2)/g and 2,5 X 10(5)/g at 21 degrees C. During storage at 0-2 degrees C the counts gradually increased and off-odors were produced when they reached values of 10(6)/g at 21 degrees C. The total volatile bases content of freshly caught krill, 0.018 to 0.038%, increased considerably during storage reaching values of approximately 0.100% when off-odors became noticeable and 0.200% or more when the odor was clearly ammoniacal. Pseudomonas spp Gp. II (Shewan) were predominant in the bacterial flora of the freshly caught krill along with Moraxella spp Alcalígenes spp, Vibrio spp, Micrococcus spp and coryneforms. The spoilage flora developed during cold storage consisted mainly of Pseudomonas spp G. II (96-100%). The results were related to the saline composition of medium; however, Pseudomonas spp Gp. II were predominant with both media used.

Secondary metabolism and interspecific competition affect accumulation of spontaneous mutants in the GacS-GacA regulatory system in Pseudomonas protegens

USDA-ARS?s Scientific Manuscript database

Secondary metabolites are synthesized by many microorganisms and provide a fitness benefit in the presence of competitors and predators. Secondary metabolism also can be costly, as it shunts energy and intermediates from primary metabolism. In Pseudomonas spp., secondary metabolism is controlled by ...

Mineralization of a Malaysian crude oil by Pseudomonas sp. and Achromabacter sp. isolated from coastal waters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmad, J.; Ahmad, M.F.

1995-12-31

Regarded as being a potentially effective tool to combat oil pollution, bioremediation involves mineralization, i.e., the conversion of complex hydrocarbons into harmless CO{sub 2} and water by action of microorganisms. Therefore, in achieving optimum effectiveness from the application of these products on crude oil in local environments, the capability of the bacteria to mineralize hydrocarbons was evaluated. The microbial laboratory testing of mineralization on local oil degraders involved, first, isolation of bacteria found at a port located on the west coast of Peninsular Malaysia. Subsequently, these bacteria were identified by means of Biomereux`s API 20E and 20 NE systems andmore » later screened by their growth on a Malaysian crude oil. Selected strains of Pseudomonas sp. and Achromabacter sp. were then exposed individually to a similar crude oil in a mineralization unit and monitored for 16 days for release of CO{sub 2}. Pseudomonas paucimobilis was found to produce more CO{sub 2} than Achromobacter sp. When tested under similar conditions, mixed populations of these two taxa produced more CO{sub 2} than that produced by any individual strain. Effective bioremediation of local crude in Malaysian waters can therefore be achieved from biochemically developed Pseudomonas sp. strains.« less

Activity of Topical Antimicrobial Agents Against Multidrug-Resistant Bacteria Recovered from Burn Patients

DTIC Science & Technology

2010-01-01

produced by Pseudomonas fluorescens [19] Inhibition of RNA and protein synthesis by targeting the isoleucine-binding site on the isoleucyl-transfer-RNA...multidrug-resistant (MDR) bacteria. We compared two methods of determining topical antimicrobial susceptibilities. Methods: Isolates of Pseudomonas ...aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), extended spectrum beta-lactamase (ESBL) producing Klebsiella pneumoniae, and

Combined physico-chemical treatments based on enterocin AS-48 for inactivation of Gram-negative bacteria in soybean sprouts.

PubMed

Cobo Molinos, Antonio; Abriouel, Hikmate; López, Rosario Lucas; Valdivia, Eva; Omar, Nabil Ben; Gálvez, Antonio

2008-08-01

Enterocin AS-48 was tested for decontamination of soybean sprouts against Gram-negative bacteria. Although treatment with bacteriocin alone had no effect on Salmonella enterica, a synergistic antimicrobial effect was detected at pH 9.0 and in combination with moderate heat treatment. Greatest inactivation was achieved for sprouts heated for 5 min at 65 degrees C in an alkaline (pH 9.0) enterocin AS-48 solution of 25 microg/ml. Bactericidal activity against S. enterica increased greatly when enterocin AS-48 was used in washing solutions in combination with several chemical compounds: EDTA, lactic acid, peracetic acid, polyphosphoric acid, sodium hypochlorite, hexadecylpyridinium chloride, propyl-p-hydroxybenzoate, and hydrocinnamic acid. The combined treatment of enterocin AS-48 and polyphosphoric acid was tested against several other Gram-negative bacteria inoculated on sprouts. The bacteria tested showed great differences in sensitivity to polyphosphoric acid, but synergism with enterocin AS-48 was confirmed in all cases. Combinations of enterocin AS-48 (25 microg/ml) and polyphosphoric acid in a concentration range of 0.1 to 2.0% significantly reduced or inhibited growth of the populations of S. enterica, Escherichia coli O157:H7, Shigella spp., Enterobacter aerogenes, Yersinia enterocolitica, Aeromonas hydrophila and Pseudomonas fluorescens in sprout samples stored at 6 degrees C and 15 degrees C. The combined treatment could therefore be applied to reduce the risks of Gram-negative pathogenic as well as spoilage bacteria on sprouts.

[A correlative study on heterotrophic bacteria and the main pollutant in city lakes' water].

PubMed

Huang, Li-Jing; Yun, Luo-Jia; Wang, Lin; Zhang, Xiao-He

2005-01-01

To provide scientific basis for bioremediation of city lake, the distribution of heterotrophic bacteria and its correlation with major pollutions condition were studied. Puping Lake and Moshui Lake of Wu Han City were choosen as the objects of our study. COD(cr) TOC, TP and TN were determined in sampled freshwater and sediment via the standard methods. At the same time the bacteria was cultivated. The average value of COD(cr), TOC, TP and TN were 8. 934 mg/L, 5.125 mg/L, 0.089 mg/L, 4.739 mg/L in Puping Lake and 86.296 mg/L,13.255 mg/ L, 1.796 mg/L, 7.325 mg/L in Moshui Lake. Ten strains of heterotrophic bacteria were isolated from the sample and they are Pseudomonas, Bacillus, Enterobateriaceae, Aeromonas and Coccus. The dominant strain in water was Pseudomonas. The proportion of Bacillus in sediment was relatively higher. In the two lakes, the average bacteria counts were 1.90 x 10(3) CFU and 5.53 x 10(4) CFU per mL in water, 3.12 x 10(5) CFU and 5.06 x 10(5) CFU per g in sediment. Puping Lake and Moshui Lake were polluted seriously according to the standard; Gram negative rods were the main types in water, and the dominant type was Pseudomonas, the Gram positive bacteria was Bacillus; The type and quantity of bacteria in Moshui Lake were higher than those in Puping Lake, and there were correlations between the quantity of bacteria and the pollutants.

Natural Transformation of Pseudomonas fluorescens and Agrobacterium tumefaciens in Soil

PubMed Central

Demanèche, Sandrine; Kay, Elisabeth; Gourbière, François; Simonet, Pascal

2001-01-01

Little information is available concerning the occurrence of natural transformation of bacteria in soil, the frequency of such events, and the actual role of this process on bacterial evolution. This is because few bacteria are known to possess the genes required to develop competence and because the tested bacteria are unable to reach this physiological state in situ. In this study we found that two soil bacteria, Agrobacterium tumefaciens and Pseudomonas fluorescens, can undergo transformation in soil microcosms without any specific physical or chemical treatment. Moreover, P. fluorescens produced transformants in both sterile and nonsterile soil microcosms but failed to do so in the various in vitro conditions we tested. A. tumefaciens could be transformed in vitro and in sterile soil samples. These results indicate that the number of transformable bacteria could be higher than previously thought and that these bacteria could find the conditions necessary for uptake of extracellular DNA in soil. PMID:11375171

Fluorescent cellular assay for screening agents inhibiting Pseudomonas aeruginosa adherence.

PubMed

Nosková, Libuše; Kubíčková, Božena; Vašková, Lucie; Bláhová, Barbora; Wimmerová, Michaela; Stiborová, Marie; Hodek, Petr

2015-01-16

Antibodies against Pseudomonas aeruginosa (PA) lectin, PAIIL, which is a virulence factor mediating the bacteria binding to epithelium cells, were prepared in chickens and purified from egg yolks. To examine these antibodies as a prophylactic agent preventing the adhesion of PA we developed a well plate assay based on fluorescently labeled bacteria and immortalized epithelium cell lines derived from normal and cystic fibrosis (CF) human lungs. The antibodies significantly inhibited bacteria adhesion (up to 50%) in both cell lines. In agreement with in vivo data, our plate assay showed higher susceptibility of CF cells towards the PA adhesion as compared to normal epithelium. This finding proved the reliability of the developed experimental system.

Alicyclobacillus spp. in the fruit juice industry: history, characteristics, and current isolation/detection procedures.

PubMed

Chang, Su-Sen; Kang, Dong-Hyun

2004-01-01

The first Alicyclobacillus spp. was isolated in 1982, and was originally thought to be strictly limited to thermophilic and acidic environments. Two years later, another Alicyclobacillus sp., A. acidoterrestris, was identified as the causative agent in spoilage of commercially pasteurized apple juice. Subsequent studies soon found that Alicyclobacillus spp. are soilborne bacteria, and do not strictly require thermophilic and acidic environments. Alicyclobacillus spp. posess several distinct characteristics; the major one is their ability to survive commercial pasteurization processes and produce off-flavors in fruit juices. The fruit juice industry has acknowledged Alicyclobacillus spp. as a major quality control target microorganism. Guaiacol and halophenols were identified as the offensive smelling agent in many Alicyclobacillus spp. related spoilage. Though the exact formation pathway of these off-flavors by Alicyclobacillus spp. are not yet identified, studies report that the presence of Alicyclobacillus spp. in the medium may be a major contributor to the formation of these off-flavors. Many identification methods and isolation media were developed in the last two decades. However, most of these methods were developed specifically for A. acidoterrestris, which was the first identified off-flavor producing Alicyclobacillus. However, recent studies indicate that other species of Alicyclobacillus may also produce guaiacol or the halophenols. In this respect, all Alicyclobacillus spp. should be monitored as potential spoilage bacteria in fruit juices. This article includes an overall review of the history of Alicyclobacillus spp., characteristics, suggested off-flavor production pathways, and commonly used identification methods for the currently identified Alicyclobacillus spp.

[Post-marketing surveillance of antibacterial activities of cefozopran against various clinical isolates--II. Gram-negative bacteria].

PubMed

Igari, Jun; Oguri, Toyoko; Hiramatsu, Nobuyoshi; Akiyama, Kazumitsu; Koyama, Tsuneo

2003-10-01

As a post-marketing surveillance, the in vitro antibacterial activities of cefozopran (CZOP), an agent of cephems, against various clinical isolates were yearly evaluated and compared with those of other cephems, oxacephems, carbapenems, monobactams, and penicillins. Changes in CZOP susceptibility among bacteria were also evaluated with the bacterial resistance ratio calculated from the breakpoint MIC. Twenty-five species (4,154 strains) of Gram-negative bacteria were isolated from the clinical materials annually collected from 1996 to 2001, and consisted of Moraxella (Branhamella) catarrhalis, Haemophilus influenzae, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Enterobacter aerogenes, Serratia marcescens, Serratia liquefaciens, Citrobacter freundii, Citrobacter koseri, Proteus mirabilis, Proteus vulgaris, Morganella morganii, Providencia spp., Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas putida, Acinetobacter baumannii, Acinetobacter Iwoffii, Burkholderia cepacia, Stenotrophomonas maltophilia, Bacteroides fragilis group, and Prevotella/Porphyromonas. CZOP preserved its antibacterial activity against M. (B.) catarrhalis (MIC90: 4 micrograms/mL) and showed comparable activity to carbapenems against H. influenzae (MIC90: 1 microgram/mL). The antibacterial activity of CZOP against E. coli was preferable (MIC90: 0.125 microgram/mL) and comparable to those of cefpirome (CPR), cefepime (CFPM), and imipenem (IPM). The MIC90 of CZOP against K. pneumoniae and K. oxytoca was 1 and 0.25 microgram/mL, respectively. The MIC90 of CZOP against E. cloacae increased during 6 years (32 to 128 micrograms/mL). The antibacterial activity of CZOP against E. aerogenes was preferable (MIC90: 1 microgram/mL). The antibacterial activities of CZOP against S. marcescens and S. liquefaciens were relatively potent (MIC90: 0.5 and 0.25 microgram/mL) and comparable to those of CPR, CFPM, and carumonam. CZOP preserved comparable antibacterial

Extracellular polysaccharides produced by cooling water tower biofilm bacteria and their possible degradation.

PubMed

Ceyhan, Nur; Ozdemir, Guven

2008-01-01

The extracellular polymers (EPS) of biofilm bacteria that can cause heat and mass transfer problems in cooling water towers in the petrochemical industry were investigated. In addition, these microorganisms were screened for their ability to grow and degrade their own EPS and the EPS of other species. Twelve bacteria producing the most EPS were isolated from cooling water towers and characterized biochemically by classic and commercial systems. These were species of Pseudomonas, Burkholderia, Aeromonas, Pasteurella, Pantoea, Alcaligenes and Sphingomonas. EPS of these species were obtained by propan-2-ol precipitation and centrifugation from bacterial cultures in media enriched with glucose, sucrose or galactose. EPS yields were of 1.68-4.95 g l(-1). These EPS materials were characterized for total sugar and protein contents. Their total sugar content ranged from 24 to 56% (g sugar g(-1) EPS), and their total protein content ranged from 10 to 28% (g protein g(-1) EPS). The monosaccharide compositions of EPS were determined by HPLC. Generally, these compositions were enriched in galactose and glucose, with lesser amounts of mannose, rhamnose, fructose and arabinose. All bacteria were investigated in terms of EPS degradation. Eight of the bacteria were able to utilize EPS from Burkholderia cepacia, seven of the bacteria were able to utilize EPS from Pseudomonas sp. and Sphingomonas paucimobilis. The greatest viscosity reduction of B. cepacia was obtained with Pseudomonas sp. The results show that the bacteria in this study are able to degrade EPS from biofilms in cooling towers.

Efficiency of autothermal thermophilic aerobic digestion and thermophilic anaerobic digestion of municipal wastewater sludge in removing Salmonella spp. and indicator bacteria.

PubMed

Zábranská, J; Dohányos, M; Jenícek, P; Růziciková, H; Vránová, A

2003-01-01

The study is focused on the comparison of autothermal thermophilic aerobic digestion, thermophilic and mesophilic anaerobic digestion, based on long-term monitoring of all processes in full-scale wastewater treatment plants, with an emphasis on the efficiency in destroying pathogens. The hygienisation effect was evaluated as a removal of counts of indicator bacteria, thermotolerant coliforms and enterococci as CFU/g total sludge solids and a frequency of a positive Salmonella spp. detection. Both thermophilic technologies of municipal wastewater sludge stabilisation had the capability of producing sludge A biosolids suitable for agricultural land application when all operational parameters (mainly temperature, mixing and retention time) were stable and maintained at an appropriate level.

Variation in the Presence of Anti-Batrachochytrium dendrobatidis Bacteria of Amphibians Across Life Stages and Elevations in Ecuador.

PubMed

Bresciano, J C; Salvador, C A; Paz-Y-Miño, C; Parody-Merino, A M; Bosch, J; Woodhams, D C

2015-06-01

Amphibian populations are decreasing worldwide due to a variety of factors. In South America, the chytrid fungus Batrachochytrium dendrobatidis (Bd) is linked to many population declines. The pathogenic effect of Bd on amphibians can be inhibited by specific bacteria present on host skin. This symbiotic association allows some amphibians to resist the development of the disease chytridiomycosis. Here, we aimed (1) to determine for the first time if specific anti-Bd bacteria are present on amphibians in the Andes of Ecuador, (2) to monitor anti-Bd bacteria across developmental stages in a focal amphibian, the Andean marsupial tree frog, Gastrotheca riobambae, that deposits larvae in aquatic habitats, and (3) to compare the Bd presence associated with host assemblages including 10 species at sites ranging in biogeography from Amazonian rainforest (450 masl) to Andes montane rainforest (3200 masl). We sampled and identified skin-associated bacteria of frogs in the field using swabs and a novel methodology of aerobic counting plates, and a combination of morphological, biochemical, and molecular identification techniques. The following anti-Bd bacteria were identified and found to be shared among several hosts at high-elevation sites where Bd was present at a prevalence of 32.5%: Janthinobacterium lividum, Pseudomonas fluorescens, and Serratia sp. Bd were detected in Gastrotheca spp. and not detected in the lowlands (sites below 1000 masl). In G. riobambae, recognized Bd-resistant bacteria start to be present at the metamorphic stage. Overall bacterial abundance was significantly higher post-metamorphosis and on species sampled at lower elevations. Further metagenomic studies are needed to evaluate the roles of host identity, life-history stage, and biogeography of the microbiota and their function in disease resistance.

A Natural Chimeric Pseudomonas Bacteriocin with Novel Pore-Forming Activity Parasitizes the Ferrichrome Transporter.

PubMed

Ghequire, Maarten G K; Kemland, Lieselore; Anoz-Carbonell, Ernesto; Buchanan, Susan K; De Mot, René

2017-02-21

Modular bacteriocins represent a major group of secreted protein toxins with a narrow spectrum of activity, involved in interference competition between Gram-negative bacteria. These antibacterial proteins include a domain for binding to the target cell and a toxin module at the carboxy terminus. Self-inhibition of producers is provided by coexpression of linked immunity genes that transiently inhibit the toxin's activity through formation of bacteriocin-immunity complexes or by insertion in the inner membrane, depending on the type of toxin module. We demonstrate strain-specific inhibitory activity for PmnH, a Pseudomonas bacteriocin with an unprecedented dual-toxin architecture, hosting both a colicin M domain, potentially interfering with peptidoglycan synthesis, and a novel colicin N-type domain, a pore-forming module distinct from the colicin Ia-type domain in Pseudomonas aeruginosa pyocin S5. A downstream-linked gene product confers PmnH immunity upon susceptible strains. This protein, ImnH, has a transmembrane topology similar to that of Pseudomonas colicin M-like and pore-forming immunity proteins, although homology with either of these is essentially absent. The enhanced killing activity of PmnH under iron-limited growth conditions reflects parasitism of the ferrichrome-type transporter for entry into target cells, a strategy shown here to be used as well by monodomain colicin M-like bacteriocins from pseudomonads. The integration of a second type of toxin module in a bacteriocin gene could offer a competitive advantage against bacteria displaying immunity against only one of both toxic activities. IMPORTANCE In their continuous struggle for ecological space, bacteria face a huge load of contenders, including phylogenetically related strains that compete for the same niche. One important group of secreted antibacterial proteins assisting in eliminating these rivals are modular bacteriocins of Gram-negative bacteria, comprising a domain for docking onto the

Molecular detection of Bartonella spp. and Rickettsia spp. in bat ectoparasites in Brazil

PubMed Central

do Amaral, Renan Bressianini; Lourenço, Elizabete Captivo; Famadas, Kátia Maria; Garcia, Amanda Barbosa; Machado, Rosangela Zacarias

2018-01-01

The family Streblidae comprises a monophyletic group of Hippoboscoidea, hematophagous dipterans that parasitize bats. Bartonella spp. and Rickettsia spp. have been reported in bats sampled in Europe, Africa, Asia, North, Central and South America. However, there are few reports on the Bartonella and Rickettsia bacteria infecting Hippoboscoidea flies and mites. While Spinturnicidae mites are ectoparasites found only in bats, those belonging to the family Macronyssidae comprise mites that also parasitize other mammal species. This study investigates the occurrence and assesses the phylogenetic positioning of Bartonella spp. and Rickettsia spp. found in Streblidae flies and Spinturnicidae and Macronyssidae mites collected from bats captured in Brazil. From May 2011 to April 2012 and September 2013 to December 2014, 400 Streblidae flies, 100 Macronyssidaes, and 100 Spinturnicidae mites were collected from bats captured in two sites in northeastern Nova Iguaçu, Rio de Janeiro, southeastern Brazil. Forty (19.8%) out of 202 Streblidae flies were positive for Bartonella spp. in qPCR assays based on the nuoG gene. Among the flies positive for the bacterium, six (18%) were Paratrichobius longicrus, seven (29%) Strebla guajiro, two (40%) Aspidoptera phyllostomatis, five (11%) Aspidoptera falcata, one (10%) Trichobius anducei, one (25%) Megistopoda aranea, and 18 (32%) Trichobius joblingi, and collected from bats of the following species: Artibeus lituratus, Carollia perspicillata, Artibeus planirostris, Sturnira lilium, and Artibeus obscurus. Six sequences were obtained for Bartonella (nuoG [n = 2], gltA [n = 2], rpoB [n = 1], ribC = 1]). The phylogenetic analysis based on gltA (750pb) gene showed that the Bartonella sequences clustered with Bartonella genotypes detected in bats and ectoparasites previously sampled in Latin America, including Brazil. Only one sample (0.49%) of the species Trichobius joblingi collected from a specimen of Carollia perspicillata was positive

Molecular detection of Bartonella spp. and Rickettsia spp. in bat ectoparasites in Brazil.

PubMed

do Amaral, Renan Bressianini; Lourenço, Elizabete Captivo; Famadas, Kátia Maria; Garcia, Amanda Barbosa; Machado, Rosangela Zacarias; André, Marcos Rogério

2018-01-01

The family Streblidae comprises a monophyletic group of Hippoboscoidea, hematophagous dipterans that parasitize bats. Bartonella spp. and Rickettsia spp. have been reported in bats sampled in Europe, Africa, Asia, North, Central and South America. However, there are few reports on the Bartonella and Rickettsia bacteria infecting Hippoboscoidea flies and mites. While Spinturnicidae mites are ectoparasites found only in bats, those belonging to the family Macronyssidae comprise mites that also parasitize other mammal species. This study investigates the occurrence and assesses the phylogenetic positioning of Bartonella spp. and Rickettsia spp. found in Streblidae flies and Spinturnicidae and Macronyssidae mites collected from bats captured in Brazil. From May 2011 to April 2012 and September 2013 to December 2014, 400 Streblidae flies, 100 Macronyssidaes, and 100 Spinturnicidae mites were collected from bats captured in two sites in northeastern Nova Iguaçu, Rio de Janeiro, southeastern Brazil. Forty (19.8%) out of 202 Streblidae flies were positive for Bartonella spp. in qPCR assays based on the nuoG gene. Among the flies positive for the bacterium, six (18%) were Paratrichobius longicrus, seven (29%) Strebla guajiro, two (40%) Aspidoptera phyllostomatis, five (11%) Aspidoptera falcata, one (10%) Trichobius anducei, one (25%) Megistopoda aranea, and 18 (32%) Trichobius joblingi, and collected from bats of the following species: Artibeus lituratus, Carollia perspicillata, Artibeus planirostris, Sturnira lilium, and Artibeus obscurus. Six sequences were obtained for Bartonella (nuoG [n = 2], gltA [n = 2], rpoB [n = 1], ribC = 1]). The phylogenetic analysis based on gltA (750pb) gene showed that the Bartonella sequences clustered with Bartonella genotypes detected in bats and ectoparasites previously sampled in Latin America, including Brazil. Only one sample (0.49%) of the species Trichobius joblingi collected from a specimen of Carollia perspicillata was positive

Production of Polyhydroxyalkanoates from Sludge Palm Oil Using Pseudomonas putida S12.

PubMed

Kang, Du-Kyeong; Lee, Cho-Ryong; Lee, Sun Hee; Bae, Jung-Hoon; Park, Young-Kwon; Rhee, Young Ha; Sung, Bong Hyun; Sohn, Jung-Hoon

2017-05-28

Polyhydroxyalkanoates (PHAs) are biodegradable plastics produced by bacteria, but their use in diverse applications is prohibited by high production costs. To reduce these costs, the conversion by Pseudomonas strains of P HAs from crude s ludge p alm oil ( SPO) a s an inexpensive renewable raw material was tested. Pseudomonas putida S12 was found to produce the highest yield (~41%) of elastomeric medium-chain-length (MCL)-PHAs from SPO. The MCL-PHA characteristics were analyzed by gas-chromatography/mass spectrometry, gel permeation chromatography, and differential scanning calorimetry. These findings may contribute to more widespread use of PHAs by reducing PHA production costs.

Ants as vectors of pathogenic microorganisms in a hospital in São Paulo county, Brazil.

PubMed

Máximo, Heros J; Felizatti, Henrique L; Ceccato, Marcela; Cintra-Socolowski, Priscila; Beretta, Ana Laura R Zeni

2014-08-20

The present study aimed to identify and characterize the presence of bacteria carried by ants, and check the distribution of these ants in the physical confines of a medium-sized hospital in São Paulo county, Brazil. The ants were collected from March 2012 to February 2013. Attractive non-toxic baits were used to catch the ants, and the sectors considered for the study were medical wards, outdoor areas, obstetric unit, reception area, kitchen, surgical centres, paediatric clinic and intensive care unit. Captured ants were classified using taxonomic keys and subsequently immersed in Brain Heart Infusion broth. Paratrechina spp. and Monomorium floricola ants were found most frequently in the hospital. Ants had a high capacity for carrying bacteria, and the isolates comprised 68.8% Gram-positive, spore-producing bacilli (Bacillus spp. and Listeria spp.); 14.7% Gram-negative bacilli (Pseudomonas aeruginosa and Klebsiella spp.); and 16.4% Gram-positive cocci (Streptococcus spp. and Staphylococcus aureus). Among the areas being evaluated, the medical wards had the largest number of ants captured, and therefore the most bacteria. Ants in hospitals may carry both Gram-positive and Gram-negative bacteria, and methods of controlling urban ants should be adopted and strictly adhered to, to minimize the risk of infection in hospital patients.

Inhibition by Agrobacterium tumefaciens and Pseudomonas savastanoi of development of the hypersensitive response elicited by Pseudomonas syringae pv. phaseolicola.

PubMed Central

Robinette, D; Matthysse, A G

1990-01-01

Injection into tobacco leaves of biotype 1 Agrobacterium tumefaciens or of Pseudomonas savastanoi inhibited the development of a visible hypersensitive response to the subsequent injection at the same site of Pseudomonas syringae pv. phaseolicola. This interference with the hypersensitive response was not seen with injection of bacterial growth medium or Escherichia coli cells. Live A. tumefaciens cells were required for the inhibitory effect. Various mutants and strains of A. tumefaciens were examined to determine the genes involved. Known chromosomal mutations generally had no effect on the ability of A. tumefaciens to inhibit the hypersensitive response, except for chvB mutants which showed a reduced (but still significant) inhibition of the hypersensitive response. Ti plasmid genes appeared to be required for the inhibition of the hypersensitive response. The bacteria did not need to be virulent in order to inhibit the hypersensitive response. Deletion of the vir region from pTi had no effect on the inhibition. However, the T region of the Ti plasmid was required for inhibition. Studies of transposon mutants suggested that the tms but not tmr or ocs genes were required. These genes were not acting after transfer to plant cells since they were effective in strains lacking vir genes and thus unable to transfer DNA to plant cells. The results suggest that the expression of the tms genes in the bacteria may inhibit the development of the hypersensitive response by the plant. An examination of the genes required in P. savastanoi for the inhibition of the hypersensitive response suggested that bacterial production of auxin was also required for the inhibition of the hypersensitive response by these bacteria. Images PMID:2211508

Oxidative Formation and Removal of Complexed Mn(III) by Pseudomonas Species

PubMed Central

Wright, Mitchell H.; Geszvain, Kati; Oldham, Véronique E.; Luther, George W.; Tebo, Bradley M.

2018-01-01

The observation of significant concentrations of soluble Mn(III) complexes in oxic, suboxic, and some anoxic waters has triggered a re-evaluation of the previous Mn paradigm which focused on the cycling between soluble Mn(II) and insoluble Mn(III,IV) species as operationally defined by filtration. Though Mn(II) oxidation in aquatic environments is primarily bacterially-mediated, little is known about the effect of Mn(III)-binding ligands on Mn(II) oxidation nor on the formation and removal of Mn(III). Pseudomonas putida GB-1 is one of the most extensively investigated of all Mn(II) oxidizing bacteria, encoding genes for three Mn oxidases (McoA, MnxG, and MopA). P. putida GB-1 and associated Mn oxidase mutants were tested alongside environmental isolates Pseudomonas hunanensis GSL-007 and Pseudomonas sp. GSL-010 for their ability to both directly oxidize weakly and strongly bound Mn(III), and to form these complexes through the oxidation of Mn(II). Using Mn(III)-citrate (weak complex) and Mn(III)-DFOB (strong complex), it was observed that P. putida GB-1, P. hunanensis GSL-007 and Pseudomonas sp. GSL-010 and mutants expressing only MnxG and McoA were able to directly oxidize both species at varying levels; however, no oxidation was detected in cultures of a P. putida mutant expressing only MopA. During cultivation in the presence of Mn(II) and citrate or DFOB, P. putida GB-1, P. hunanensis GSL-007 and Pseudomonas sp. GSL-010 formed Mn(III) complexes transiently as an intermediate before forming Mn(III/IV) oxides with the overall rates and extents of Mn(III,IV) oxide formation being greater for Mn(III)-citrate than for Mn(III)-DFOB. These data highlight the role of bacteria in the oxidative portion of the Mn cycle and suggest that the oxidation of strong Mn(III) complexes can occur through enzymatic mechanisms involving multicopper oxidases. The results support the observations from field studies and further emphasize the complexity of the geochemical cycling of

Oxidative Formation and Removal of Complexed Mn(III) by Pseudomonas Species.

PubMed

Wright, Mitchell H; Geszvain, Kati; Oldham, Véronique E; Luther, George W; Tebo, Bradley M

2018-01-01

The observation of significant concentrations of soluble Mn(III) complexes in oxic, suboxic, and some anoxic waters has triggered a re-evaluation of the previous Mn paradigm which focused on the cycling between soluble Mn(II) and insoluble Mn(III,IV) species as operationally defined by filtration. Though Mn(II) oxidation in aquatic environments is primarily bacterially-mediated, little is known about the effect of Mn(III)-binding ligands on Mn(II) oxidation nor on the formation and removal of Mn(III). Pseudomonas putida GB-1 is one of the most extensively investigated of all Mn(II) oxidizing bacteria, encoding genes for three Mn oxidases (McoA, MnxG, and MopA). P. putida GB-1 and associated Mn oxidase mutants were tested alongside environmental isolates Pseudomonas hunanensis GSL-007 and Pseudomonas sp. GSL-010 for their ability to both directly oxidize weakly and strongly bound Mn(III), and to form these complexes through the oxidation of Mn(II). Using Mn(III)-citrate (weak complex) and Mn(III)-DFOB (strong complex), it was observed that P. putida GB-1, P. hunanensis GSL-007 and Pseudomonas sp. GSL-010 and mutants expressing only MnxG and McoA were able to directly oxidize both species at varying levels; however, no oxidation was detected in cultures of a P. putida mutant expressing only MopA. During cultivation in the presence of Mn(II) and citrate or DFOB, P. putida GB-1, P. hunanensis GSL-007 and Pseudomonas sp. GSL-010 formed Mn(III) complexes transiently as an intermediate before forming Mn(III/IV) oxides with the overall rates and extents of Mn(III,IV) oxide formation being greater for Mn(III)-citrate than for Mn(III)-DFOB. These data highlight the role of bacteria in the oxidative portion of the Mn cycle and suggest that the oxidation of strong Mn(III) complexes can occur through enzymatic mechanisms involving multicopper oxidases. The results support the observations from field studies and further emphasize the complexity of the geochemical cycling of

Interkingdom Gene Transfer of a Hybrid NPS/PKS from Bacteria to Filamentous Ascomycota

PubMed Central

Lawrence, Daniel P.; Kroken, Scott; Pryor, Barry M.; Arnold, A. Elizabeth

2011-01-01

Nonribosomal peptides (NRPs) and polyketides (PKs) are ecologically important secondary metabolites produced by bacteria and fungi using multidomain enzymes called nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs), respectively. Previous phylogenetic analyses of fungal NRPSs and PKSs have suggested that a few of these genes were acquired by fungi via horizontal gene transfer (HGT) from bacteria, including a hybrid NPS/PKS found in Cochliobolus heterostrophus (Dothideomycetes, Ascomycota). Here, we identify this hybrid gene in fungi representing two additional classes of Ascomycota (Aspergillus spp., Microsporum canis, Arthroderma spp., and Trichophyton spp., Eurotiomycetes; Chaetomium spp. and Metarhizium spp., Sordariomycetes) and use phylogenetic analyses of the most highly conserved domains from NRPSs (adenylation (A) domain) and PKSs (ketoacyl synthase (KS) domain) to examine the hypothesis that the hybrid NPS7/PKS24 was acquired by fungi from bacteria via HGT relatively early in the evolution of the Pezizomycotina. Our results reveal a unique ancestry of the A domain and KS domain in the hybrid gene relative to known fungal NRPSs and PKSs, provide strong evidence for HGT of the hybrid gene from a putative bacterial donor in the Burkholderiales, and suggest the HGT event occurred early in the evolution of the filamentous Ascomycota. PMID:22140558

Toxin-Antitoxin Systems in Clinical Pathogens

PubMed Central

Fernández-García, Laura; Blasco, Lucia; Lopez, Maria; Bou, German; García-Contreras, Rodolfo; Wood, Thomas; Tomas, María

2016-01-01

Toxin-antitoxin (TA) systems are prevalent in bacteria and archaea. Although not essential for normal cell growth, TA systems are implicated in multiple cellular functions associated with survival under stress conditions. Clinical strains of bacteria are currently causing major human health problems as a result of their multidrug resistance, persistence and strong pathogenicity. Here, we present a review of the TA systems described to date and their biological role in human pathogens belonging to the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) and others of clinical relevance (Escherichia coli, Burkholderia spp., Streptococcus spp. and Mycobacterium tuberculosis). Better understanding of the mechanisms of action of TA systems will enable the development of new lines of treatment for infections caused by the above-mentioned pathogens. PMID:27447671

Identification of pink-pigmented bacteria isolated from environmental water samples and their biofilm formation abilities.

PubMed

Furuhata, Katsunori; Kato, Yuko; Goto, Keiichi; Saitou, Keiko; Sugiyama, Jun-Ichi; Hara, Motonobu; Fukuyama, Masahumi

2008-06-01

Sixty-seven strains of pink-pigmented bacteria, which were isolated from environmental water samples collected nationwide, were identified by partial 16S rDNA sequence analysis. In addition, the biofilm formation ability of the isolates was experimentally investigated. We could identify only 2 strains at the species level: Pedobacter roseus HS-38 and Runella slithyformis HS-77. The results showed that of the strains tested, 22 strains (32.8%) were Pedobacter spp., which was most frequently identified, followed by 19 strains (28.4%) of Arcicella spp., 16 strains (23.9%) of Deinococcus spp., 5 strains (7.5%) of Roseomonas spp., 4 strains (6.0%) of Flectobacillus spp. and 1 strain (1.5%) of Runella sp. Most isolates showed low similarity values to previously known species, and they were found to be novel species. At a result, it was difficult to identify environmental water-derived pink-pigmented bacteria at the species level. On the other hand, when we measured the absorbance by the crystal violet staining to examine the quantities of biofilm formation of these strains, fifty-five (82.0%) of the 67 isolates formed biofilm. The absorbance of Deinococcus sp. HS-75 was the highest (3.56). When comparing the absorbance values among the genera, Roseomonas spp. showed the highest absorbance (mean:1.62), followed by Deinococcus spp. (mean: 1.03), and Arcicella spp. (mean: 1.01). Strains of Flectobacillus spp. (mean: 0.48) and Pedobacter spp. (mean: 0.42) showed lower absorbance values. As above, it was shown that, at the species level, the pink-pigmented bacteria in the water in the Japanese environment had various levels of ability to form biofilm.

Dynamics of Legionella spp. and bacterial populations during the proliferation of L. pneumophila in a cooling tower facility.

PubMed

Wéry, Nathalie; Bru-Adan, Valérie; Minervini, Céline; Delgénes, Jean-Philippe; Garrelly, Laurent; Godon, Jean-Jacques

2008-05-01

The dynamics of Legionella spp. and of dominant bacteria were investigated in water from a cooling tower plant over a 9-month period which included several weeks when Legionella pneumophila proliferated. The structural diversity of both the bacteria and the Legionella spp. was monitored by a fingerprint technique, single-strand conformation polymorphism, and Legionella spp. and L. pneumophila were quantified by real-time quantitative PCR. The structure of the bacterial community did not change over time, but it was perturbed periodically by chemical treatment or biofilm detachment. In contrast, the structure of the Legionella sp. population changed in different periods, its dynamics at times showing stability but also a rapid major shift during the proliferation of L. pneumophila in July. The dynamics of the Legionella spp. and of dominant bacteria were not correlated. In particular, no change in the bacterial community structure was observed during the proliferation of L. pneumophila. Legionella spp. present in the cooling tower system were identified by cloning and sequencing of 16S rRNA genes. A high diversity of Legionella spp. was observed before proliferation, including L. lytica, L. fallonii, and other Legionella-like amoebal pathogen types, along with as-yet-undescribed species. During the proliferation of L. pneumophila, Legionella sp. diversity decreased significantly, L. fallonii and L. pneumophila being the main species recovered.

Dynamics of Legionella spp. and Bacterial Populations during the Proliferation of L. pneumophila in a Cooling Tower Facility▿

PubMed Central

Wéry, Nathalie; Bru-Adan, Valérie; Minervini, Céline; Delgénes, Jean-Philippe; Garrelly, Laurent; Godon, Jean-Jacques

2008-01-01

The dynamics of Legionella spp. and of dominant bacteria were investigated in water from a cooling tower plant over a 9-month period which included several weeks when Legionella pneumophila proliferated. The structural diversity of both the bacteria and the Legionella spp. was monitored by a fingerprint technique, single-strand conformation polymorphism, and Legionella spp. and L. pneumophila were quantified by real-time quantitative PCR. The structure of the bacterial community did not change over time, but it was perturbed periodically by chemical treatment or biofilm detachment. In contrast, the structure of the Legionella sp. population changed in different periods, its dynamics at times showing stability but also a rapid major shift during the proliferation of L. pneumophila in July. The dynamics of the Legionella spp. and of dominant bacteria were not correlated. In particular, no change in the bacterial community structure was observed during the proliferation of L. pneumophila. Legionella spp. present in the cooling tower system were identified by cloning and sequencing of 16S rRNA genes. A high diversity of Legionella spp. was observed before proliferation, including L. lytica, L. fallonii, and other Legionella-like amoebal pathogen types, along with as-yet-undescribed species. During the proliferation of L. pneumophila, Legionella sp. diversity decreased significantly, L. fallonii and L. pneumophila being the main species recovered. PMID:18390683

Characterization of the spoilage potential of pure and mixed cultures of bacterial species isolated from tropical yellowfin tuna (Thunnus albacares).

PubMed

Silbande, A; Cornet, J; Cardinal, M; Chevalier, F; Rochefort, K; Smith-Ravin, J; Adenet, S; Leroi, F

2018-02-01

The spoilage potential of 28 bacterial strains isolated from spoiled raw yellowfin tuna was evaluated. Bacterial species were inoculated in irradiated tuna matrix. Chemical changes, bacterial growth and sensory quality were monitored during aerobic storage at 8°C. Pseudomonas spp., Enterobacter spp. and Escherichia hermanii had no spoiling effect. Brochothrix thermosphacta and Carnobacterium divergens/maltaromaticum developed moderate unpleasant odours. Hafnia paralvei and Serratia spp. released strong off-odours (pyrrolidine, sulphur/cabbage). No bacterial group (except H. paralvei) combined with Pseudomonas spp. deteriorated the sensory quality of tuna. When C. divergens/maltaromaticum was associated with H. paralvei or B. thermosphacta, the odour is close to the naturally contaminated tuna stored on the same conditions. The pH, total volatile basic nitrogen (TVBN) and trimethylamine (TMA) were not correlated with the spoilage. The bacterial species had a different impact on the sensory quality of the fish. The bacterial interactions lead to an enhancement or an inhibition of the spoilage potential and the bacterial growth. The specific spoilage organism (SSO) appears to be an association of lactic acid bacteria (LAB) with Enterobacteriaceae or B. thermosphacta. Pseudomonas, often dominant at the sensory rejection time, is not a good quality indicator. © 2017 The Society for Applied Microbiology.

Phylogenetic Analysis of Polygalacturonase-Producing Bacillus and Pseudomonas Isolated From Plant Waste Material

PubMed Central

Sohail, Muhammad; Latif, Zakia

2016-01-01

Background: Keeping in mind the commercial application of polygalacturonase (PG) in juice and beverages industry, bacterial strains were isolated from rotten fruits and vegetables to screen for competent producers of PG. Objectives: In this study, the plate method was used for preliminary screening of polygalacturonase-producing bacteria, while the Dinitrosalicylic Acid (DNS) method was used for quantifications of PG. Materials and Methods: Biochemically-identified polygalacturonase-producing Bacillus and Pseudomonas species were further characterized by molecular markers. The genetic diversity among these selected strains was analyzed by investigating microsatellite distribution in their genome. Out of 110 strains, 17 competent strains of Bacillus and eight strains of Pseudomonas were selected, identified and confirmed biochemically. Selected strains were characterized by 16S rRNA sequencing and data was submitted to the national center for biotechnology information (NCBI) website for accession numbers. Results: Among the Bacillus, Bacillus vallismortis (JQ990307) isolated from mango was the most competent producer of PG; producing up to 4.4 U/µL. Amongst Pseudomonas, Pseudomonas aeruginosa (JQ990314) isolated from oranges was the most competent PG producer equivalent to B. vallismortis (JQ990307). To determine genetic diversity of different strains of Pseudomonas and Bacillus varying in PG production, fingerprinting was done on the basis of Simple Sequence Repeats (SSR) or microsatellites. The data was analyzed and a phylogenetic tree was constructed using the Minitab 3 software for comparison of bacterial isolates producing different concentrations of PG. Fingerprinting showed that presence or absence of certain microsatellites correlated with the ability of PG production. Conclusions: Bacteria from biological waste were competent producers of PG and must be used on an industrial scale to cope with the demand of PG in the food industry. PMID:27099686

Photodynamic antimicrobial therapy to inhibit pseudomonas aeruginosa of corneal isolates (Conference Presentation)

NASA Astrophysics Data System (ADS)

Durkee, Heather A.; Relhan, Nidhi; Arboleda, Alejandro; Halili, Francisco; De Freitas, Carolina; Alawa, Karam; Aguilar, Mariela C.; Amescua, Guillermo; Miller, Darlene; Parel, Jean-Marie

2016-03-01

Keratitis associated with Pseudomonas aeruginosa is difficult to manage. Treatment includes antibiotic eye drops, however, some strains of Pseudomonas aeruginosa are resistant. Current research efforts are focused on finding alternative and adjunct therapies to treat multi-drug resistant bacteria. One promising alternate technique is photodynamic therapy (PDT). The purpose of this study was to evaluate the effect of riboflavin- and rose bengal-mediated PDT on Pseudomonas aeruginosa keratitis isolates in vitro. Two isolates (S+U- and S-U+) of Pseudomonas aeruginosa were derived from keratitis patients and exposed to five experimental groups: (1) Control (dark, UV-A irradiation, 525nm irradiation); (2) 0.1% riboflavin (dark, UV-A irradiation); and (3) 0.1% rose bengal, (4) 0.05% rose bengal and (5) 0.01% rose bengal (dark, 525nm irradiation). Three days after treatment, in dark conditions of all concentration of riboflavin and rose bengal showed no inhibition in both S+U- and S-U+ strains of Pseudomonas aeruginosa. In 0.1% and 0.05% rose bengal irradiated groups, for both S+U- and S-U+ strains, there was complete inhibition of bacterial growth in the central 50mm zone corresponding to the diameter of the green light source. These in vitro results suggest that rose bengal photodynamic therapy may be an effective adjunct treatment for Pseudomonas aeruginosa keratitis.

Stimulating Central Carbon Metabolism to Re-sensitize Pseudomonas aeruginosa to Aminoglycosides.

PubMed

Martins, Dorival; Nguyen, Dao

2017-02-16

In this issue of Cell Chemical Biology, Meylan et al. (2017) examine how stimulation of central carbon metabolism of Pseudomonas aeruginosa modulates aminoglycoside lethality in tolerant bacteria. They identify fumarate as a tobramycin potentiator that stimulates proton motive force-dependent drug uptake and increases respiration-dependent killing. Copyright © 2017. Published by Elsevier Ltd.

An alternative bacteriological medium for the isolation of Aeromonas spp.

USGS Publications Warehouse

Jenkins, J.A.; Taylor, P.W.

1995-01-01

Two solid bacteriologic media were compared for cultivating Aeromonas spp. from piscine sources: the Rimler-Shotts (RS) medium and a starch-glutamate-ampicillin-penicillin-based medium (SGAP-10C) used for the recovery of Aeromonas spp. from water samples. The selective and differential capacities of the media were assessed March through October 1992 by recovery rate and phenotype of 99 isolates representing 15 genera of bacteria. Recovery frequency of Aeromonas spp. (n = 62) was similar at 97% on RS and 95% on SGAP-10C. The SGAP-10C medium proved to be more specific than RS toward Aeromonas species (P ≤ 0.005). Use of SGAP-10C at 24 C for 48 hr offers a better choice for the laboratory recovery of Aeromonas spp. from clinical fish specimens.

The First Report of Drug Resistant Bacteria Isolated from the Brown-Banded Cockroach, Supella longipalpa, in Ahvaz, South-western Iran

PubMed Central

Vazirianzadeh, Babak; Dehghani, Rouhullah; Mehdinejad, Manijeh; Sharififard, Mona; Nasirabadi, Nersi

2014-01-01

Background The brown-banded cockroach, Supella longipalpa is known as a carrier of pathogenic bacteria in urban environments, but its role is not well documented regarding the carriage of antibiotic-resistant pathogenic bacteria in Iran. The aim of this study was to determine the resistance bacteria isolated from the brown-banded cockroach in Ahvaz, south west of Iran. Methods: Totally 39 cockroaches were collected from kitchen area of houses and identified. All specimens were cultured to isolate the bacterial agents on blood agar and MacConky agar media. The microorganisms were identified using necessary differential and biochemical tests. Antimicrobial susceptibility tests were performed for isolated organisms by Kirby-Bauer’s disk diffusion according to NCLI guideline, using 18 antibiotics. Results: From the 39 collected S. langipalpa, 179 bacterial agents were isolated, 92 of alimentary ducts and 87 of external body surfaces. Isolated bacteria from cockroaches were identified as Enterobacter spp., Klebsiella spp., Citrobacter spp., Escherichia coli, Salmonella spp., Proteus spp., coagulase negative staphylococci, Serratia marcescens, Staphylococcus aureus, and Bacillus species. The pattern resistance rates were determined for gram negative bacilli and gram positive cocci regarding 18 antibiotics. Conclusion: The brown-banded cockroach can be involved in the spread of drug resistant bacteria and increases the possibility of contacting human environment to drug resistant bacteria. Therefore, the potential of removing this insect should be improved. This is the first original report of drug resistant bacteria isolated from the brown-banded cockroach of Iran. PMID:25629065

Inhibition of Cell Differentiation in Bacillus subtilis by Pseudomonas protegens

PubMed Central

Powers, Matthew J.; Sanabria-Valentín, Edgardo; Bowers, Albert A.

2015-01-01

ABSTRACT Interspecies interactions have been described for numerous bacterial systems, leading to the identification of chemical compounds that impact bacterial physiology and differentiation for processes such as biofilm formation. Here, we identified soil microbes that inhibit biofilm formation and sporulation in the common soil bacterium Bacillus subtilis. We did so by creating a reporter strain that fluoresces when the transcription of a biofilm-specific gene is repressed. Using this reporter in a coculture screen, we identified Pseudomonas putida and Pseudomonas protegens as bacteria that secrete compounds that inhibit biofilm gene expression in B. subtilis. The active compound produced by P. protegens was identified as the antibiotic and antifungal molecule 2,4-diacetylphloroglucinol (DAPG). Colonies of B. subtilis grown adjacent to a DAPG-producing P. protegens strain had altered colony morphologies relative to B. subtilis colonies grown next to a DAPG-null P. protegens strain (phlD strain). Using a subinhibitory concentration of purified DAPG in a pellicle assay, we saw that biofilm-specific gene transcription was delayed relative to transcription in untreated samples. These transcriptional changes also corresponded to phenotypic alterations: both biofilm biomass and spore formation were reduced in B. subtilis liquid cultures treated with subinhibitory concentrations of DAPG. Our results add DAPG to the growing list of antibiotics that impact bacterial development and physiology at subinhibitory concentrations. These findings also demonstrate the utility of using coculture as a means to uncover chemically mediated interspecies interactions between bacteria. IMPORTANCE Biofilms are communities of bacteria adhered to surfaces by an extracellular matrix; such biofilms can have important effects in both clinical and agricultural settings. To identify chemical compounds that inhibited biofilm formation, we used a fluorescent reporter to screen for bacteria that

IDENTITY OF THE PINK-PIGMENTED METHANOL-OXIDIZING BACTERIA AS VIBRIO EXTORQUENS

PubMed Central

Stocks, Peter K.; McCleskey, C. S.

1964-01-01

Stocks, Peter K. (Louisiana State University, Baton Rouge), and C. S. McCleskey. Identity of the pink-pigmented methanol-oxidizing bacteria as Vibrio extorquens. J. Bacteriol. 88:1065–1070. 1964.—Pink-pigmented bacteria isolated from enrichment cultures of methane oxidizers were found to possess similar morphological, cultural, and physiological characteristics. All the strains utilized methanol, formate, oxalate, succinate, glycerol, and benzene as sole carbon sources; methanol, formate, and glycerol afforded best growth. Most strains utilized fructose and ribose; other carbohydrates tested were not available as carbon and energy sources. There was strain variation in the use of hexane, heptane, n-propanol, n-butanol, acetate, and propionate. Methane, ethane, n-propane, and n-butane were not utilized. Our isolates, and Pseudomonas methanica of Harrington and Kallio (not the methane-dependent P. methanica of Dworkin and Foster), Pseudomonas AM1 of Peele and Quayle, Pseudomonas PRL-W4 of Kaneda and Roxburgh, and Protaminobacter ruber den Dooren de Jong are nearly identical with Vibrio extorquens (Bassalik) Bhat and Barker, and should be considered the same species. Images PMID:14219020

IDENTITY OF THE PINK-PIGMENTED METHANOL-OXIDIZING BACTERIA AS VIBRIO EXTORQUENS.

PubMed

STOCKS, P K; MCCLESKEY, C S

1964-10-01

Stocks, Peter K. (Louisiana State University, Baton Rouge), and C. S. McCleskey. Identity of the pink-pigmented methanol-oxidizing bacteria as Vibrio extorquens. J. Bacteriol. 88:1065-1070. 1964.-Pink-pigmented bacteria isolated from enrichment cultures of methane oxidizers were found to possess similar morphological, cultural, and physiological characteristics. All the strains utilized methanol, formate, oxalate, succinate, glycerol, and benzene as sole carbon sources; methanol, formate, and glycerol afforded best growth. Most strains utilized fructose and ribose; other carbohydrates tested were not available as carbon and energy sources. There was strain variation in the use of hexane, heptane, n-propanol, n-butanol, acetate, and propionate. Methane, ethane, n-propane, and n-butane were not utilized. Our isolates, and Pseudomonas methanica of Harrington and Kallio (not the methane-dependent P. methanica of Dworkin and Foster), Pseudomonas AM1 of Peele and Quayle, Pseudomonas PRL-W4 of Kaneda and Roxburgh, and Protaminobacter ruber den Dooren de Jong are nearly identical with Vibrio extorquens (Bassalik) Bhat and Barker, and should be considered the same species.

Introducing a Novel Media to Improve the Recovery of Culturable Bacteria from the Fish Parasite Anisakis spp. larvae (Nematoda: Anisakidae).

PubMed

Svanevik, Cecilie S; Lunestad, Bjørn T

2017-09-01

This paper describes a cultivation method to increase the recovery of bacteria from the marine muscle-invading parasitic nematode larvae of Anisakis spp. These larvae hold a high and complex population of accumulated bacteria, originating from seawater, crustaceans, fish, and marine mammals, all involved in the lifecycle of Anisakis. Two in-house agars based on fish juice prepared by either mechanical or enzymatic degradation of the fish tissue, were made. The Anisakis larvae were homogenised prior to cultivation on the in-house fish juice agars and the bacterial numbers and diversity were compared to those obtained applying the commercially available Marine Agar and Iron Agar Lyngby. Bacterial colonies of unique appearance were subcultured and identified by 16S rRNA gene sequencing. Totally three of twenty identified taxa were found on the in-house fish juice agars only. Fish juice agar prepared enzymatically would be the best supplementary agar, as this agar gave significantly higher heterotrophic plate counts, compared to mechanical preparation. The enzymatically prepared fish juice gave more suitable agar quality, was more resource efficient, and had apparently increased nutrient density and availability.

Gallbladder microbiota variability in Colombian gallstones patients.

PubMed

Arteta, Ariel Antonio; Carvajal-Restrepo, Hernan; Sánchez-Jiménez, Miryan Margot; Diaz-Rodriguez, Sergio; Cardona-Castro, Nora

2017-03-31

Gallbladder stones are a very frequently occurring condition. Despite bile bactericidal activity, many bacteria have been detected inside the gallbladder, and gallstones facilitate their presence. Between 3% and 5% of the patients with Salmonella spp. infection develop the carrier stage, with the bacteria persisting inside the gallbladder, shedding bacteria in their feces without signs of infection. The aim of this study was to isolate bacteria from Colombian patients with gallstones, using standard culturing methods, and to identify Salmonella spp. carriers by molecular techniques. A total of 149 patients (120 female and 29 male) diagnosed with gallstones who underwent cholecystectomy and who did not have symptoms of acute inflammation were included. Gallbladder tissue and bile were cultured and used for DNA extraction and Salmonella spp. hilA gene detection. Of the 149 patients 28 (19%) had positive cultures. Twenty-one (75%) patients with positive cultures were from Medellin's metropolitan area. In this geographical location, the most frequent isolations were Pseudomonas spp. (38%), Klebsiella spp. (23%), and Proteus spp. (9%) in addition to unique cases of other bacteria. In Apartado, the isolates found were Enterobacter cloacae (50%), Raoultella terrigena (32%), and both Enterobacter cloacae and Raoultella terrigena were isolated in one (18%) male patient. Five (3.3%) of the 149 patients had positive polymerase chain reaction (PCR) results for the hilA gene of Salmonella spp., all of whom were female and residents of the Medellín metropolitan area. The gallbladder microbiota variability found could be related to geographical, ethnic, and environmental conditions.

External Bacterial Flora and Antimicrobial Susceptibility Patterns of Staphylococcus spp. and Pseudomonas spp. Isolated from Two Household Cockroaches, Blattella germanica and Blatta orientalis.

PubMed

Menasria, Taha; Tine, Samir; Mahcene, Djaouida; Benammar, Leyla; Megri, Rochdi; Boukoucha, Mourad; Debabza, Manel

2015-04-01

A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches (Blattella germanica and Blatta orientalis) collected from households in Tebessa (northeast Algeria). Three major bacterial groups were cultured (total aerobic, enterobacteria, and staphylococci) from 14 specimens of cockroaches, and antibiotic susceptibility was tested for both Staphylococcus and Pseudomonas isolates. Culturing showed that the total bacterial load of cockroaches from different households were comparable (P<0.001) and enterobacteria were the predominant colonizers of the insect surface, with a bacterial load of (2.1 × 10⁵ CFU/insect), whereas the staphylococci group was the minority. Twenty-eight bacterial species were isolated, and susceptibility patterns showed that most of the staphylococci isolates were highly susceptible to chloramphenicol, gentamycin, pristinamycin, ofloxacin, clindamycin, and vancomycin; however, Pseudomonas strains exhibited resistance to amoxicillin/clavulanic acid, imipenem, and the second-generation antibiotic cephalosporin cefuroxime. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Effect of Diuron on aquatic bacteria in laboratory-scale wastewater treatment ponds with special reference to Aeromonas species studied by colony hybridization.

PubMed

Sumpono; Perotti, P; Belan, A; Forestier, C; Lavedrine, B; Bohatier, J

2003-01-01

Six laboratory-scale wastewater treatment ponds were filled with sediment and water obtained from a reference pond (a wastewater treatment plant located in a rural environment at Montel-de-Gelat, Puy-de-Dôme, France). They were kept at 20 degrees C, with alternative light and dark periods (12 h-12 h), and fed with raw effluent supplied weekly. Three of them were treated with Diuron (dissolved in DMSO) at a final concentration 10 mg/l, while the other three received only DMSO. Physico-chemical parameters, total bacteria, cultivable bacteria, and Aeromonas spp. were measured periodically until 41 days after the Diuron contamination. Total bacteria were treated with 4,6-diamidino 2-phenylindole (DAPI) and counted by epifluoroscence microscopy. The cultivable bacteria were quantified on plate count agar medium and Aeromonas spp. using colony hybridization. In the contaminated pilots, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), suspended solids (SS), volatile suspended solids (VSS), ammonium, phosphorus, and bacteria increased, but dissolved oxygen decreased. The abundance of total bacteria, cultivable bacteria (multiplied by 30), and Aeromonas spp. increased for two weeks after Diuron introduction, reverting to initial values three weeks later. The percentage of cultivable bacteria relative to total bacteria was 0.2% in controls and 1.2% in treated pilots, while the percentage of Aeromonas spp. relative to cultivable bacteria decreased from 6-10% to 2%. Our results suggest that Diuron, which acts on the photosystem II of phototrophs, supports the development of cultivable bacteria through new carbon sources derived from the decomposition of photosynthetic micro-organisms, but does not specifically support Aeromonas spp.

Prevalence of Pseudomonas aeruginosa and Acinetobacter spp. in subgingival biofilm and saliva of subjects with chronic periodontal infection.

PubMed

Souto, Renata; Silva-Boghossian, Carina M; Colombo, Ana Paula Vieira

2014-01-01

P. aeruginosa and Acinetobacter spp. are important pathogens associated with late nosocomial pneumonia in hospitalized and institutionalized individuals. The oral cavity may be a major source of these respiratory pathogens, particularly in the presence of poor oral hygiene and periodontal infection. This study investigated the prevalence of P. aeruginosa and Acinetobacter spp. in subgingival biofilm and saliva of subjects with periodontal disease or health. Samples were obtained from 55 periodontally healthy (PH) and 169 chronic periodontitis (CP) patients. DNA was obtained from the samples and detection of P. aeruginosa and Acinetobacter spp. was carried out by multiplex and nested PCR. P. aeruginosa and Acinetobacter spp. were detected in 40% and 45% of all samples, respectively. No significant differences in the distribution of these microorganisms between men and women, subgingival biofilm and saliva samples, patients ≤ 35 and > 35 years of age, and smokers and non-smokers were observed regardless periodontal status (p > 0.05). In contrast, the frequencies of P. aeruginosa and Acinetobacter spp. in saliva and biofilm samples were significantly greater in CP than PH patients (p < 0.01). Smokers presenting P. aeruginosa and high frequencies of supragingival plaque were more likely to present CP than PH. P. aeruginosa and Acinetobacter spp. are frequently detected in the oral microbiota of CP. Poor oral hygiene, smoking and the presence of P. aeruginosa are strongly associated with periodontitis.

Prevalence of Pseudomonas aeruginosa and Acinetobacter spp. in subgingival biofilm and saliva of subjects with chronic periodontal infection

PubMed Central

Souto, Renata; Silva-Boghossian, Carina M.; Colombo, Ana Paula Vieira

2014-01-01

P. aeruginosa and Acinetobacter spp. are important pathogens associated with late nosocomial pneumonia in hospitalized and institutionalized individuals. The oral cavity may be a major source of these respiratory pathogens, particularly in the presence of poor oral hygiene and periodontal infection. This study investigated the prevalence of P. aeruginosa and Acinetobacter spp. in subgingival biofilm and saliva of subjects with periodontal disease or health. Samples were obtained from 55 periodontally healthy (PH) and 169 chronic periodontitis (CP) patients. DNA was obtained from the samples and detection of P. aeruginosa and Acinetobacter spp. was carried out by multiplex and nested PCR. P. aeruginosa and Acinetobacter spp. were detected in 40% and 45% of all samples, respectively. No significant differences in the distribution of these microorganisms between men and women, subgingival biofilm and saliva samples, patients ≤ 35 and > 35 years of age, and smokers and non-smokers were observed regardless periodontal status (p > 0.05). In contrast, the frequencies of P. aeruginosa and Acinetobacter spp. in saliva and biofilm samples were significantly greater in CP than PH patients (p < 0.01). Smokers presenting P. aeruginosa and high frequencies of supragingival plaque were more likely to present CP than PH. P. aeruginosa and Acinetobacter spp. are frequently detected in the oral microbiota of CP. Poor oral hygiene, smoking and the presence of P. aeruginosa are strongly associated with periodontitis. PMID:25242933

Whole-Genome Sequence and Classification of 11 Endophytic Bacteria from Poison Ivy (Toxicodendron radicans)

PubMed Central

Tran, Phuong N.; Tan, Nicholas E. H.; Lee, Yin Peng; Gan, Han Ming; Polter, Steven J.; Dailey, Lucas K.; Hudson, André O.

2015-01-01

Here, we report the whole-genome sequences and annotation of 11 endophytic bacteria from poison ivy (Toxicodendron radicans) vine tissue. Five bacteria belong to the genus Pseudomonas, and six single members from other genera were found present in interior vine tissue of poison ivy. PMID:26586879

The effect of zinc limitation on the transcriptome of Pseudomonas protegens Pf-5

USDA-ARS?s Scientific Manuscript database

Zinc is an important nutrient but can be lacking in some soil environments, influencing the physiology of soil-dwelling bacteria. Hence, we studied the global effect of zinc limitation on the transcriptome of the rhizosphere biocontrol strain Pseudomonas protegens Pf-5. We observed that the expressi...

Lectin-Like Bacteriocins from Pseudomonas spp. Utilise D-Rhamnose Containing Lipopolysaccharide as a Cellular Receptor

PubMed Central

Josts, Inokentijs; Roszak, Aleksander W.; Waløen, Kai I.; Cogdell, Richard J.; Milner, Joel; Evans, Tom; Kelly, Sharon; Tucker, Nicholas P.; Byron, Olwyn; Smith, Brian; Walker, Daniel

2014-01-01

Lectin-like bacteriocins consist of tandem monocot mannose-binding domains and display a genus-specific killing activity. Here we show that pyocin L1, a novel member of this family from Pseudomonas aeruginosa, targets susceptible strains of this species through recognition of the common polysaccharide antigen (CPA) of P. aeruginosa lipopolysaccharide that is predominantly a homopolymer of d-rhamnose. Structural and biophysical analyses show that recognition of CPA occurs through the C-terminal carbohydrate-binding domain of pyocin L1 and that this interaction is a prerequisite for bactericidal activity. Further to this, we show that the previously described lectin-like bacteriocin putidacin L1 shows a similar carbohydrate-binding specificity, indicating that oligosaccharides containing d-rhamnose and not d-mannose, as was previously thought, are the physiologically relevant ligands for this group of bacteriocins. The widespread inclusion of d-rhamnose in the lipopolysaccharide of members of the genus Pseudomonas explains the unusual genus-specific activity of the lectin-like bacteriocins. PMID:24516380

Plastic Encapsulation of Stabilized Escherichia coli and Pseudomonas putida

PubMed Central

Manzanera, M.; Vilchez, S.; Tunnacliffe, A.

2004-01-01

Escherichia coli and Pseudomonas putida dried in hydroxyectoine or trehalose are shown to be highly resistant to the organic solvents chloroform and acetone, and consequently, they can be encapsulated in a viable form in solid plastic materials. Bacteria are recovered by rehydration after physical disruption of the plastic. P. putida incorporated into a plastic coating of maize seeds was shown to colonize roots efficiently after germination. PMID:15128579

Activation of bovine neutrophils by Brucella spp.

PubMed

Keleher, Lauren L; Skyberg, Jerod A

2016-09-01

Brucellosis is a globally important zoonotic infectious disease caused by gram negative bacteria of the genus Brucella. While many species of Brucella exist, Brucella melitensis, Brucella abortus, and Brucella suis are the most common pathogens of humans and livestock. The virulence of Brucella is largely influenced by its ability to evade host factors, including phagocytic killing mechanisms, which are critical for the host response to infection. The aim of this study was to characterize the bovine neutrophil response to virulent Brucella spp. Here, we found that virulent strains of smooth B. abortus, B. melitensis, B. suis, and virulent, rough, strains of Brucella canis possess similar abilities to resist killing by resting, or IFN-γ-activated, bovine neutrophils. Bovine neutrophils responded to infection with a time-dependent oxidative burst that varied little between Brucella spp. Inhibition of TAK1, or SYK kinase blunted the oxidative burst of neutrophils in response to Brucella infection. Interestingly, Brucella spp. did not induce robust death of bovine neutrophils. These results indicate that bovine neutrophils respond similarly to virulent Brucella spp. In addition, virulent Brucella spp., including naturally rough strains of B. canis, have a conserved ability to resist killing by bovine neutrophils. Copyright © 2016 Elsevier B.V. All rights reserved.

Microbial investigation of biofilms recovered from endotracheal tubes using sonication in intensive care unit pediatric patients.

PubMed

Ferreira, Thiago de Oliveira; Koto, Rafael Yoshio; Leite, Gabriel Fialkovitz da Costa; Klautau, Giselle Burlamaqui; Nigro, Stanley; Silva, Cely Barreto da; Souza, Ana Paula Idalgo da Fonseca; Mimica, Marcelo Jenne; Cesar, Regina Grigolli; Salles, Mauro José Costa

2016-01-01

To compare cultured microorganisms identified on endotracheal tubes biofilms through sonication technique with traditional tracheal aspirate collected at extubation of pediatric intensive care unit patients. Demographic and epidemiological data were analyzed to identify factors possibly related with the microbiological profile of the two collection methods. Associations between categorical and continuous variables were analyzed using the chi-square or Fisher's exact test, or Student's t test. p-Value <0.05 were considered significant. Thirty endotracheal tubes and tracheal aspirates samples from 27 subjects were analyzed. Only one patient presented the clinical diagnosis of ventilator-associated pneumonia. Overall, 50% of bacteria were Gram-negative bacilli, followed by Gram-positive bacteria in 37%, and fungi in 10%. No statistically significant difference on the distribution of Gram-positive or Gram-negative bacteria (p=0.996), and fungi (p=0.985) were observed between the collection methods. Pseudomonas spp. was the most frequent microorganism identified (23.8%), followed by Streptococcus spp. (18.5%), Acinetobacter spp. (15.9%), coagulase-negative staphylococci (11.2%), and Klebsiella spp. (8.6%). Concordant results between methods amounted to 83.3%. Pseudomonas aeruginosa and Acinetobacter baumannii showed carbapenem resistance in 50% and 43.7% of the isolates, respectively. In general, cultures after endotracheal tubes sonication (non-centrifuged sonication fluid and centrifuged sonication fluid) yielded bacteria with higher rates of antimicrobial resistance compared to tracheal aspirates cultures. Additionally, in 12 subjects (40%), we observed discrepancies regarding microbiologic profiles of cultures performed using the collection methods. Our study demonstrated that sonication technique can be applied to ET biofilms to identify microorganisms attached to their surface with a great variety of species identified. However, we did not find significant

Insight into the role of facultative bacteria stimulated by micro-aeration in continuous bioreactors converting LCFA to methane.

PubMed

Duarte, Maria Salomé; Silva, Sérgio A; Salvador, Andreia F; Cavaleiro, Ana Júlia; Stams, Alfons J M; Alves, Maria Madalena; Pereira, Maria Alcina

2018-05-15

Conversion of unsaturated long chain fatty acids (LCFA) to methane in continuous bioreactors is not fully understood. Palmitate (C16:0) often accumulates during oleate (C18:1) biodegradation in methanogenic bioreactors, and the reason why this happens and which microorganisms catalyze this reaction remains unknown. Facultative anaerobic bacteria are frequently found in continuous reactors operated at high LCFA loads, but their function is unclear. To get more insight on the role of these bacteria, LCFA conversion was studied under microaerophilic conditions. For that, we compared bioreactors treating oleate-based wastewater (organic loading rates of 1 and 3 kg COD m-3 d-1), operated under different redox conditions (strictly anaerobic-AnR, -350 mV; microaerophilic-MaR, -250 mV). At the higher load, palmitate accumulated 7 times more in the MaR, where facultative anaerobes were more abundant, and only the biomass from this reactor could recover the methanogenic activity after a transient inhibition. In a second experiment, the abundance of facultative anaerobic bacteria, particularly Pseudomonas spp. (from which two strains were isolated), was strongly correlated (p<0.05) with palmitate-to-total LCFA percentage in the biofilm formed in a continuous plug flow reactor fed with very high loads of oleate. This work strongly suggests that micro-aeration stimulates the development of facultative bacteria that are critical for achieving LCFA conversion to methane in continuous bioreactors. Microbial networks and interactions of facultative and strict anaerobes in microbial communities should be considered in future studies.

Occurrence of enteropathogenic bacteria in birds of prey in Italy.

PubMed

Gargiulo, A; Fioretti, A; Russo, T P; Varriale, L; Rampa, L; Paone, S; De Luca Bossa, L M; Raia, P; Dipineto, L

2018-03-01

The importance of wild birds as potential vectors of disease has received recent renewed empirical interest, especially regarding human health although information regarding the enteropathogenic bacteria in birds of prey continue to be scant. This study was performed with the aim to evaluate the occurrence of enteropathogenic bacteria (i.e. Campylobacter spp. Escherichia coli, Salmonella spp.) in birds of prey carcasses in Southern Italy. The results of the present study showed a prevalence of 33·1% (49/148) for Campylobacter spp. where all positive isolates (49/49) were identified as Campylobacter jejuni, and among these positive 12/49 were also identified as Campylobacter coli. Thus, 12/49 birds of prey showed mixed infections for both Campylobacter species. Differences in Campylobacter spp. prevalence between diurnal and nocturnal birds were statistically significant (P = 0·016). Escherichia coli showed a prevalence of 6·8% (10/148) and were serogrouped as O26 (n = 3), O55 (n = 2), O145 (n = 5). Salmonella spp. showed a prevalence of 6·8% (10/148) and were serotyped as S. Napoli (n = 4), Salmonella salamae (n = 3) and S. Typhimurium (n = 3). Although wildlife disease outbreaks have often been underreported in the broader context of global epidemiology, results of the present study suggest that birds of prey may serve as a reservoir of pathogens for livestock and human health, acting at the animal-human-ecosystem interface. This study confirms the role of birds of prey as a reservoir of enteropathogenic bacteria (i.e. Campylobacter spp., Escherichia coli, Salmonella spp.). Wild birds can contaminate environment with their faeces and play a crucial role in the transmission of pathogens to poultry and livestock farms and aquifers supplying water to humans. Furthermore, wild birds could disseminate pathogens within rescue and rehabilitation centres where they are admitted. © 2017 The Society for Applied Microbiology.

Prevalence of bacterial pathogens and their anti-microbial resistance in Tilapia and their pond water in Trinidad.

PubMed

Newaj-Fyzul, A; Mutani, A; Ramsubhag, A; Adesiyun, A

2008-05-01

In Trinidad, Tilapia (Oreonchromis spp.) is one of the most important fresh water food fish and the number of farms has been increasing annually. A study was conducted in the local tilapia industry to determine the microbial quality of pond water, prevalence of bacterial pathogens and their anti-microbial resistance using the disk diffusion method. Seventy-five apparently healthy fish and 15 pond water samples from three of the four commercial tilapia fish farms in the country were processed. The 202 bacterial isolates recovered from fish slurry and 88 from water, belonged to 13 and 16 genera respectively. The predominant bacteria from fish slurry were Pseudomonas spp. (60.0%), Aeromonas spp. (44.0%), Plesiomonas (41.3%) and Chromobacterium (36.0%) (P < 0.05; chi(2)) compared with isolates from pond water where Bacillus spp. (80.0%), Staphylococcus spp., Alcaligenes spp. and Aeromonas spp. (60.0%) were most prevalent (P < 0.05; chi(2)). Using eight anti-microbial agents, to test bacteria from five genera (Aeromonas, Chromobacterium, Enterobacter, Plesiomonas and Pseudomonas), 168 (97.1%) of 173 bacterial isolates from fish slurry exhibited resistance to one or more anti-microbial agents compared with 47 (90.4%) of 52 from water (P > 0.05; chi(2)). Resistance was high to ampicillin, 90.2% (158 of 173), erythromycin, 66.5% (115 of 173) and oxytetracycline, 52.6%, (91 of 173) but relatively low to chloramphenicol, 9.8% (17 of 173) and sulphamethoxazole/trimethoprim, 6.4% (11 of 173) (P < 0.05; chi(2)). For pond water isolates, the frequency of resistance across bacterial genera ranged from 75% (nine of 12) for Chromobacter spp. to 100% found amongst Enterobacter spp. (six of six), Plesiomonas spp. (nine of nine) and Pseudomonas spp. (eight of eight) (P < 0.05; chi(2)). Resistance was generally high to ampicillin, 78.8% (41 of 52), erythromycin, 51.9% (27 of 52) and oxytetracycline, 34.5% (18 of 52) but low to sulphamethoxazole/trimethoprim, 7.7% (four of 52) and

Comparison of hot versus cold boning of beef carcasses on bacterial growth and the risk of blown pack spoilage.

PubMed

Reid, Rachael; Fanning, Séamus; Whyte, Paul; Kerry, Joe; Bolton, Declan

2017-03-01

Primals were prepared from beef Longissimus thoracis et lumborum (LTL), psoas major (PM), quadriceps femoris (QF) and semitendinosus (S) muscles from cold and hot boned carcasses, vacuum-packaged and stored for 42 or 100days at 2°C and 7°C. Storage temperature, carcass or primal surface temperature, pH and a w were monitored. Samples were taken periodically and tested for total viable count mesophilic (TVCm), TVC psychrophilic (TVCp), total Enterobacteriaceae count (TEC), presumptive Pseudomonas spp., lactic acid bacteria (LAB), Clostridium spp. and Brochothrix thermosphacta. A fifth muscle, biceps femoris (BF), was used to examine the impact of hot boning on blown pack spoilage (BPS). Primal counts increased to 6-7log 10 cfucm -2 after 6weeks. Significantly (P<0.05) higher TEC, Pseudomonas spp. and Br. thermosphacta counts were observed on cold versus hot boned primals. In contrast, significantly (P<0.05) higher TVC, LAB and Clostridium spp. concentrations were obtained on hot boned beef. Moreover, BPS pack distension/bursting occurred considerably sooner in hot boned product. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quorum quenching activity in cell-free lysate of endophytic bacteria isolated from Pterocarpus santalinus Linn., and its effect on quorum sensing regulated biofilm in Pseudomonas aeruginosa PAO1.

PubMed

Rajesh, P S; Ravishankar Rai, V

2014-01-01

Quorum sensing mechanism allows the microorganisms to resist the antibiotic treatment by forming biofilms. Quorum quenching is one of the mechanisms to control the development of drug resistance in microbes. Endophyte bacteria are beneficial to plant growth as they support the immune system against the pathogen attack. The endophytic bacteria present in Pterocarpus santalinus were screened for the presence of N-acyl homoserine lactones (AHLs) degrading bacteria using biosensor strains and further confirmed by quantifying the violacein production. Cell-free lysate of endophytic bacteria, Bacillus firmus PT18 and Enterobacter asburiae PT39 exhibited potent AHL degrading ability by inhibiting about 80% violacein production in biosensor strain. Furthermore, when the cell-free lysate was applied to Pseudomonas aeruginosa PAO1 and PAO1-JP2 biofilm it resulted in significant (p<0.01) inhibition of biofilm formation. The biofilm inhibition was confirmed by visualization of biofilm slides under fluorescence microscopy, which showed decrease in total biomass formation in treated slides. Isolation and amplification of the gene (aiiA) indicated that the presence of AHL lactonase in cell-free lysate and sequence alignment indicated that AiiA contains a "HXHXDH" zinc-binding motif that is being conserved in several groups of metallohydrolases. Therefore, the study shows the potential of AHLs degradation by AHL lactonase present in cell-free lysate of isolated endophytic bacteria and inhibition of quorum sensing regulated biofilm formation in P. aeruginosa PAO1. Copyright © 2013 Elsevier GmbH. All rights reserved.

Activity and cellular localization of amylases of rabbit cecal bacteria.

PubMed

Sirotek, K; Marounek, M; Suchorská, O

2006-01-01

Five 11-week-old rabbits, fed a commercial granulated feed, were slaughtered and cecal starch-degrading bacteria enumerated; total concentration of cultivable bacteria utilizing starch averaged 5.5 x 10(10) CFU/g. The activity and cellular localization of amylases was determined in 9 bacteria identified as Actinomyces israeli (strains AA2 and AD4), Bacteroides spp. (strain AA3), Dichelobacter nodosus (strain AA4), Mitsuokella multiacidus (strain AA6), Eubacterium spp. (strains AA7 and AB2), Clostridium spp. (strains AD1 and AA5). Four strains (AA3, AA4, AA5, AD4) produced extracellular amylases with an activity of 26-35 micromol of reducing sugars per h per mg of protein; in five strains (AA2, AA6, AA7, AB2, AD1) amylases were membrane-bound with an activity of 14-18 micromol of reducing sugars per h per mg of protein. All strains exhibited a low intracellular amylolytic activity. The pH optimum of amylases was 6.8-7.0. In strains producing extracellular amylases a substantial loss of viscosity was observed during incubations of cultivation supernatant with starch, similar to viscosity reduction in starch solutions treated with alpha-amylase; this indicates an endo-type (random cleavage) of extracellular amylase reaction in the bacteria under study. No strain possessed glucoamylase activity.

Oral Anaerobic Bacteria in the Etiology of Ankylosing Spondylitis

PubMed Central

Öğrendik, Mesut

2017-01-01

Ankylosing spondylitis (AS) is associated with periodontitis. Anti–Porphyromonas gingivalis and anti–Prevotella intermedia antibody titers were higher in patients with spondyloarthritis than in healthy people. Sulfasalazine is an effective antibiotic treatment for AS. Moxifloxacin and rifamycin were also found to be significantly effective. The etiology hypothesis suggests that oral anaerobic bacteria such as Porphyromonas spp and Prevotella spp contribute to the disease. These bacteria have been identified in AS, and we will discuss their pathogenic properties with respect to our knowledge of the disease. Periodontal pathogens are likely to be responsible for the development of AS in genetically susceptible individuals. This finding should guide the development of more comprehensive and efficacious treatment strategies for AS. PMID:28638241

The Influence of Pseudomonas fluorescens on Corrosion Products of Archaeological Tin-Bronze Analogues

NASA Astrophysics Data System (ADS)

Ghiara, G.; Grande, C.; Ferrando, S.; Piccardo, P.

2018-01-01

In this study, tin-bronze analogues of archaeological objects were investigated in the presence of an aerobic Pseudomonas fluorescens strain in a solution, containing chlorides, sulfates, carbonates and nitrates according to a previous archaeological characterization. Classical fixation protocols were employed in order to verify the attachment capacity of such bacteria. In addition, classical metallurgical analytical techniques were used to detect the effect of bacteria on the formation of uncommon corrosion products in such an environment. Results indicate quite a good attachment capacity of the bacteria to the metallic surface and the formation of the uncommon corrosion products sulfates and sulfides is probably connected to the bacterial metabolism.

Legionella and non-Legionella bacteria in a biological treatment plant.

PubMed

Fykse, Else Marie; Aarskaug, Tone; Thrane, Ingjerd; Blatny, Janet Martha

2013-02-01

Legionella pneumophila were previously identified in the aeration ponds (up to 10(10) CFU/L) of a biological wastewater treatment plant at Borregaard Ind. Ltd., Sarpsborg, Norway, and in air samples (up to 3300 CFU/m(3)) collected above the aeration ponds. After 3 outbreaks of Legionnaires' disease reported in this area in 2005 and 2008, the aeration ponds of the plant were shut down by the Norwegian authorities in September 2008. The aim of the present work was to analyze the Legionella and non-Legionella bacterial communities in the aeration ponds before and during the shutdown process and to identify potential human pathogens. The non-Legionella bacterial community was investigated in selected samples during the shutdown process by 16S rDNA sequencing of clone libraries (400 clones) and growth analysis. The concentration of L. pneumophila and Pseudomonas spp. DNA were monitored by quantitative PCR. Results showed a decrease in the concentration of L. pneumophila and Pseudomonas spp. during the shutdown. This was accompanied by a significant change in the composition of the bacterial community in the aeration ponds. This study demonstrated that several advanced analytical methods are necessary to characterize the bacterial population in complex environments, such as the industrial aeration ponds.

Prevalence of Legionella spp. in water systems of hospitals and hotels in South Western Greece.

PubMed

Fragou, K; Kokkinos, P; Gogos, C; Alamanos, Y; Vantarakis, A

2012-01-01

The aim of the present study was to determine the prevalence of Legionella spp. in water systems of hospitals and hotels located in South Western Greece, to study the molecular epidemiology of the isolated strains and their possible association with bacterial contamination (total count and Pseudomonas aeruginosa), the water pH, and temperature. A prevalence survey for Legionella spp. by culturing techniques in water distribution systems of eight hospitals and nine hotels occurred in South Western Greece. Water sampling and microbiological analysis were carried out following the ISO methods. Legionella pneumophila was detected in 33% and 36% of the distribution systems of hospitals and hotels, respectively. Our survey results suggest a frequent prevalence of elevated concentrations of Legionella spp. in water systems of hospitals and hotels. Our investigation has confirmed the need to regularly monitor the microbiological condition of water systems in hospitals and hotels.

Recovery and screening for antibiotic susceptibility of potential bacterial pathogens from the oral cavity of shark species involved in attacks on humans in Recife, Brazil.

PubMed

Interaminense, J A; Nascimento, D C O; Ventura, R F; Batista, J E C; Souza, M M C; Hazin, F H V; Pontes-Filho, N T; Lima-Filho, J V

2010-08-01

The number of incidents involving sharks and humans at beaches in Recife, on the north-eastern Brazilian coast, is among the highest worldwide. In addition, wound infections in survivors are common; but the nature and risk of the aetiological agents is unknown. In the present study, 81 potential bacterial pathogens were identified in the oral cavity of sharks involved in attacks in Recife, and were subjected to antibiotic susceptibility tests using the standardized disc-diffusion method. The majority were enterobacteria such as Enterobacter spp., Citrobacter spp., Proteus spp., Providencia alcalifaciens, Escherichia coli, Moellerella wisconcensis and Leclercia adecarboxylata. Other Gram-negative bacteria included Vibrio spp., Burkholderia cepacia, Acinetobacter spp. and Pseudomonas spp. In addition, coagulase-positive and coagulase-negative Staphylococcus spp., Enterococcus spp. and Micrococcus spp. were identified, besides Streptococcus spp. from the viridans group. Resistance was especially found in the Proteus mirabilis and Citrobacter freundii, and ranged from 4 to 6 antibiotics out of the 13 tested. Gentamicin and vancomycin were the most effective against Gram-positive cocci strains, whereas levofloxacin was fully inhibitory against Gram-positive and Gram-negative bacteria. These data are discussed in light of a retrospective evaluation of the medical records of three shark victims treated at Restauração Hospital in Recife.

Whole-Genome Sequence and Classification of 11 Endophytic Bacteria from Poison Ivy (Toxicodendron radicans).

PubMed

Tran, Phuong N; Tan, Nicholas E H; Lee, Yin Peng; Gan, Han Ming; Polter, Steven J; Dailey, Lucas K; Hudson, André O; Savka, Michael A

2015-11-19

Here, we report the whole-genome sequences and annotation of 11 endophytic bacteria from poison ivy (Toxicodendron radicans) vine tissue. Five bacteria belong to the genus Pseudomonas, and six single members from other genera were found present in interior vine tissue of poison ivy. Copyright © 2015 Tran et al.

Use of Tetra-ammonium Tetrakis(4-Sulphonato)Phenyl Porphyrin for Pseudomonas and Bacillus Cell Imaging

PubMed Central

Sujatha, V.; Sridhar, Bharat; Krishnamurthy, Srinath; Vinod Kumar, K. S.; Senthil Kumar, K.; Gautam, Pennathur

2010-01-01

The use of tetraammonium tetrakis(4-sulphonato)phenyl porphyrin (TPPS), a water-soluble anionic compound, as a stain to analyse bacterial cells using fluorescent microscopy was investigated. TPPS was effectively used to analyse two different bacteria: Pseudomonas aeruginosa and Bacillus cereus. The variation in brightness with varying concentrations of TPPS was studied. The patterns of variations for these bacteria were found to be the same, but with consistently higher brightness for Bacillus cereus. PMID:20811478

Effect of black pepper essential oil on the quality of fresh pork during storage.

PubMed

Zhang, Jing; Wang, Ying; Pan, Dao-Dong; Cao, Jin-Xuan; Shao, Xing-Feng; Chen, Yin-Ji; Sun, Yang-Ying; Ou, Chang-Rong

2016-07-01

The effect of different concentrations (0, 0.1 and 0.5%, v/v) of black pepper essential oil (BPEO) on thiobarbituric acid reactive substances (TBARS), meat color, the percentage of metmyoglobin (MetMb%), microbiological parameters and total volatile basic nitrogen (TVB-N) of pork loins stored at 4°C for 9days was evaluated. BPEO treatments showed lower TBARS, MetMb%, yellowness (b*) values, Pseudomonas spp. and Enterobacteriaceae count and TVB-N values and higher lightness (L*) and redness (a*) values than the control during storage; the effectiveness of BPEO was dose-dependent. The retardation of the formation of MetMb by adding BPEO ensured higher L* and a* values and lower b* values than the control at 6 and 9days; the MetMb content has a similar trend to the lipid oxidation. The lower TVB-N value of BPEO treatments than the control could be attributed to the inhibition of Pseudomonas spp. and Enterobacteriaceae. Gram-negative bacteria were more sensitive than Gram-positive bacteria to BPEO. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bronchial microbial patterns in severe exacerbations of chronic obstructive pulmonary disease (COPD) requiring mechanical ventilation.

PubMed

Soler, N; Torres, A; Ewig, S; Gonzalez, J; Celis, R; El-Ebiary, M; Hernandez, C; Rodriguez-Roisin, R

1998-05-01

We carried out a comprehensive microbiological study of the upper and lower airways in patients with severe exacerbations of chronic obstructive pulmonary disease (COPD) requiring mechanical ventilation in order to describe microbial patterns and analyze their clinical significance. Quantitative cultures of tracheobronchial aspirates (TBAs), bronchoscopically retrieved protected specimen brush (PSB) and bronchoalveolar lavage fluid (BALF) at admission to the ICU and after 72 h, as well as serology for bacteria and respiratory viruses were performed. Fifty patients (mean age 68 +/- 8, 46 males) were studied prospectively. Potentially pathogenic microorganisms (PPMs) and/or a positive serology were present in 36 of 50 (72%) patients, including 12 (33%) polymicrobial cases. Only six (12%) had no pathogen in any sample in the absence of antimicrobial pretreatment. Microbial patterns corresponded to community-acquired pathogens (Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis) in 19 of 34 (56%) and to gram-negative enteric bacilli (GNEB), Pseudomonas, and Stenotrophomonas spp. in 15 of 34 (44%) of isolates. Chlamydia pneumoniae and respiratory viruses were found in 18% and 16% of investigations, respectively. Repeated investigation after 72 h in 19 patients with PPMs in the initial investigation revealed eradication of virtually all isolates of community-acquired pathogens and GNEB but persistence of three of five Pseudomonas spp. and both Stenotrophomonas spp. as well as the emergence of new GNEB, Pseudomonas and Stenotrophomonas spp. Clinical parameters neither predicted the presence of PPMs nor of GNEB and Pseudomonas/Stenotrophomonas spp. Nevertheless, severe pneumonia attributable to initially isolated pathogens occurred in two patients with severe COPD exacerbation. We conclude that pathogens were more frequently present than previously reported. The rate of GNEB and Pseudomonas/Stenotrophomonas spp. isolates was high. The presence of

Oral flora of Python regius kept as pets.

PubMed

Dipineto, L; Russo, T P; Calabria, M; De Rosa, L; Capasso, M; Menna, L F; Borrelli, L; Fioretti, A

2014-05-01

This study was aimed at evaluating the oral bacterial flora of 60 Python regius kept as pets by culture and biochemical methods. All isolates were also submitted to antimicrobial susceptibility testing using the disc diffusion method. The oral cavity of snakes sampled harboured a wide range of Gram-negative bacteria mainly constituted by Pseudomonas spp., Morganella morganii, Acinetobacter calcoaceticus, Aeromonas hydrophila, but also by Salmonella spp. Staphylococcus spp. was the commonest Gram-positive isolates, and various anaerobic Clostridium species were also found. The most effective antimicrobial agents were enrofloxacin and ciprofloxacin, followed by doxycycline and gentamicin. The oral cavity of snakes sampled harboured a wide range of bacteria. Our results suggest that people who come in contact with snakes could be at risk of infection and should follow proper hygiene practices when handling these reptiles. © 2014 The Society for Applied Microbiology.

Bacterial Tethering Analysis Reveals a “Run-Reverse-Turn” Mechanism for Pseudomonas Species Motility

PubMed Central

Qian, Chen; Wong, Chui Ching; Swarup, Sanjay

2013-01-01

We have developed a program that can accurately analyze the dynamic properties of tethered bacterial cells. The program works especially well with cells that tend to give rise to unstable rotations, such as polar-flagellated bacteria. The program has two novel components. The first dynamically adjusts the center of the cell's rotational trajectories. The second applies piecewise linear approximation to the accumulated rotation curve to reduce noise and separate the motion of bacteria into phases. Thus, it can separate counterclockwise (CCW) and clockwise (CW) rotations distinctly and measure rotational speed accurately. Using this program, we analyzed the properties of tethered Pseudomonas aeruginosa and Pseudomonas putida cells for the first time. We found that the Pseudomonas flagellar motor spends equal time in both CCW and CW phases and that it rotates with the same speed in both phases. In addition, we discovered that the cell body can remain stationary for short periods of time, leading to the existence of a third phase of the flagellar motor which we call “pause.” In addition, P. aeruginosa cells adopt longer run lengths, fewer pause frequencies, and shorter pause durations as part of their chemotactic response. We propose that one purpose of the pause phase is to allow the cells to turn at a large angle, where we show that pause durations in free-swimming cells positively correlate with turn angle sizes. Taken together, our results suggest a new “run-reverse-turn” paradigm for polar-flagellated Pseudomonas motility that is different from the “run-and-tumble” paradigm established for peritrichous Escherichia coli. PMID:23728820

Pseudomonas-related populations associated with reverse osmosis in drinking water treatment.

PubMed

Sala-Comorera, Laura; Blanch, Anicet R; Vilaró, Carles; Galofré, Belén; García-Aljaro, Cristina

2016-11-01

Reverse osmosis membrane filtration technology (RO) is used to treat drinking water. After RO treatment, bacterial growth is still observed in water. However, it is not clear whether those microorganisms belong to species that can pose a health risk, such as Pseudomonas spp. The goal of this study is to characterize the bacterial isolates from a medium that is selective for Pseudomonas and Aeromonas which were present in the water fraction before and after the RO. To this end, isolates were recovered over two years and were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. They were then biochemically phenotyped and the population similarity indexes were calculated. The isolates were analysed for their capacity to form biofilms in vitro and antimicrobial susceptibility. There were significant differences between the microbial populations in water before and after RO. Furthermore, the structures of the populations analysed at the same sampling point were similar in different sampling campaigns. Some of the isolates had the capacity to form a biofilm and showed resistance to different antibiotics. A successful level filtration via RO and subsequent recolonization of the membrane with different species from those in the feed water was found. Pseudomonas aeruginosa was not recovered from among the isolates. This study increases the knowledge on the microorganisms present in water after RO treatment, with focus in one of the genus causing problems in RO systems associated with human health risk, Pseudomonas. Copyright © 2016 Elsevier Ltd. All rights reserved.

Detection of and Response to Signals Involved in Host-Microbe Interactions by Plant-Associated Bacteria

PubMed Central

Brencic, Anja; Winans, Stephen C.

2005-01-01

Diverse interactions between hosts and microbes are initiated by the detection of host-released chemical signals. Detection of these signals leads to altered patterns of gene expression that culminate in specific and adaptive changes in bacterial physiology that are required for these associations. This concept was first demonstrated for the members of the family Rhizobiaceae and was later found to apply to many other plant-associated bacteria as well as to microbes that colonize human and animal hosts. The family Rhizobiaceae includes various genera of rhizobia as well as species of Agrobacterium. Rhizobia are symbionts of legumes, which fix nitrogen within root nodules, while Agrobacterium tumefaciens is a pathogen that causes crown gall tumors on a wide variety of plants. The plant-released signals that are recognized by these bacteria are low-molecular-weight, diffusible molecules and are detected by the bacteria through specific receptor proteins. Similar phenomena are observed with other plant pathogens, including Pseudomonas syringae, Ralstonia solanacearum, and Erwinia spp., although here the signals and signal receptors are not as well defined. In some cases, nutritional conditions such as iron limitation or the lack of nitrogen sources seem to provide a significant cue. While much has been learned about the process of host detection over the past 20 years, our knowledge is far from being complete. The complex nature of the plant-microbe interactions makes it extremely challenging to gain a comprehensive picture of host detection in natural environments, and thus many signals and signal recognition systems remain to be described. PMID:15755957

Degradation of soil cyanide by single and mixed cultures of Pseudomonas stutzeri and Bacillus subtilis.

PubMed

Nwokoro, Ogbonnaya; Dibua, Marie Esther Uju

2014-03-01

The aim of this investigation was to study whether certain bacteria could be used for cyanide degradation in soil. The bacteria Pseudomonas stutzeri and Bacillus subtilis were selected based on their good growth in a minimal medium containing 0.8 mg mL-1 potassium cyanide (KCN). In this study we tested their ability to reduce cyanide levels in a medium containing 1.5 mg mL-1 of KCN. Although both microorganisms reduced cyanide levels, Pseudomonas stutzeri was the more effective test organism. Later on, the selected cultures were grown, diluted and their various cell concentrations were used individually and in combination to test their ability of cyanide degradation in soil samples collected around a cassava processing mill. Bacillus subtilis caused degradation of soil cyanide from 0.218 mg g-1 soil immediately with an inoculum concentration of 0.1 (OD600nm) to 0.072 mg g-1 soil after 10 days with an inoculum concentration of 0.6 (OD600nm) implying a 66.9 % reduction. Pseudomonas stutzeri cell concentration of 0.1 (OD600nm) decreased soil cyanide from 0.218 mg g-1 soil initially to 0.061 mg g-1 soil after 10 days with an inoculum concentration of 0.6 (OD600nm) (72 % reduction). The mixed culture of the two bacteria produced the best degradation of soil cyanide from 0.218 mg g-1 soil sample with a combined inoculum concentration of 0.1 (OD600nm) initially to 0.025 mg g-1 soil with a combined inoculum concentration of 0.6 (OD600nm) after 10 days incubation resulting in an 88.5 % degradation of soil cyanide. The analysed bacteria displayed high cyanide degradation potential and may be useful for efficient decontamination of cyanide contaminated sites.

Environmental transcriptome analysis reveals physiological differences between biofilm and planktonic modes of life of the iron oxidizing bacteria Leptospirillum spp. in their natural microbial community.

PubMed

Moreno-Paz, Mercedes; Gómez, Manuel J; Arcas, Aida; Parro, Víctor

2010-06-24

Extreme acidic environments are characterized by their high metal content and lack of nutrients (oligotrophy). Macroscopic biofilms and filaments usually grow on the water-air interface or under the stream attached to solid substrates (streamers). In the Río Tinto (Spain), brown filaments develop under the water stream where the Gram-negative iron-oxidizing bacteria Leptospirillum spp. (L. ferrooxidans and L. ferriphilum) and Acidithiobacillus ferrooxidans are abundant. These microorganisms play a critical role in bioleaching processes for industrial (biominery) and environmental applications (acid mine drainage, bioremediation). The aim of this study was to investigate the physiological differences between the free living (planktonic) and the sessile (biofilm associated) lifestyles of Leptospirillum spp. as part of its natural extremely acidophilic community. Total RNA extracted from environmental samples was used to determine the composition of the metabolically active members of the microbial community and then to compare the biofilm and planktonic environmental transcriptomes by hybridizing to a genomic microarray of L. ferrooxidans. Genes up-regulated in the filamentous biofilm are involved in cellular functions related to biofilm formation and maintenance, such as: motility and quorum sensing (mqsR, cheAY, fliA, motAB), synthesis of cell wall structures (lnt, murA, murB), specific proteases (clpX/clpP), stress response chaperons (clpB, clpC, grpE-dnaKJ, groESL), etc. Additionally, genes involved in mixed acid fermentation (poxB, ackA) were up-regulated in the biofilm. This result, together with the presence of small organic acids like acetate and formate (1.36 mM and 0.06 mM respectively) in the acidic (pH 1.8) water stream, suggests that either L. ferrooxidans or other member of the microbial community are producing acetate in the acidophilic biofilm under microaerophilic conditions. Our results indicate that the acidophilic filaments are dynamic structures

Autochthonous bioaugmentation with environmental samples rich in hydrocarbonoclastic bacteria for bench-scale bioremediation of oily seawater and desert soil.

PubMed

Ali, Nedaa; Dashti, Narjes; Salamah, Samar; Al-Awadhi, Husain; Sorkhoh, Naser; Radwan, Samir

2016-05-01

Oil-contaminated seawater and desert soil batches were bioaugmented with suspensions of pea (Pisum sativum) rhizosphere and soil with long history of oil pollution. Oil consumption was measured by gas-liquid chromatography. Hydrocarbonoclastic bacteria in the bioremediation batches were counted using a mineral medium with oil vapor as a sole carbon source and characterized by their 16S ribosomal RNA (rRNA)-gene sequences. Most of the oil was consumed during the first 2-4 months, and the oil-removal rate decreased or ceased thereafter due to nutrient and oxygen depletion. Supplying the batches with NaNO3 (nitrogen fertilization) at a late phase of bioremediation resulted in reenhanced oil consumption and bacterial growth. In the seawater batches bioaugmented with rhizospheric suspension, the autochthonous rhizospheric bacterial species Microbacterium oxidans and Rhodococcus spp. were established and contributed to oil-removal. The rhizosphere-bioaugmented soil batches selectively favored Arthrobacter nitroguajacolicus, Caulobacter segnis, and Ensifer adherens. In seawater batches bioaugmented with long-contaminated soil, the predominant oil-removing bacterium was the marine species Marinobacter hydrocarbonoclasticus. In soil batches on the other hand, the autochthonous inhabitants of the long-contaminated soil, Pseudomonas and Massilia species were established and contributed to oil removal. It was concluded that the use of rhizospheric bacteria for inoculating seawater and desert soil and of bacteria in long-contaminated soil for inoculating desert soil follows the concept of "autochthonous bioaugmentation." Inoculating seawater with bacteria in long-contaminated soil, on the other hand, merits the designation "allochthonous bioaugmentation."

[Post-marketing surveillance of antibacterial activities of cefozopran against various clinical isolates--II. Gram-negative bacteria].

PubMed

Igari, Jun; Oguri, Toyoko; Hiramatsu, Nobuyoshi; Akiyama, Kazumitsu; Koyama, Tsuneo

2002-02-01

As a post-marketing surveillance, the in vitro antibacterial activities of cefozopran (CZOP), an agent of cephems, against various clinical isolates were yearly evaluated and compared with those of other cephems, oxacephems, penicillins, monobactams, and carbapenems. Changes in CZOP susceptibility for the bacteria were also evaluated with the bacterial resistance ratio calculated with the breakpoint MIC. Twenty-five species (3,362 strains) of Gram-negative bacteria were isolated from the clinical materials annually collected from 1996 to 2000, and consisted of Moraxella (Branhamella) catarrhalis (n = 136), Haemophilus influenzae (n = 289), Escherichia coli (n = 276), Klebsiella pneumoniae (n = 192), Klebsiella oxytoca (n = 157), Enterobacter cloacae (n = 189), Enterobacter aerogenes (n = 93), Serratia marcescens (n = 172), Serratia liquefaciens (n = 24), Citrobacter freundii (n = 177), Citrobacter koseri (n = 70), Proteus mirabilis (n = 113), Proteus vulgaris (n = 89), Morganella morganii (n = 116), Providencia spp. (n = 41), Pseudomonas aeruginosa (n = 290), Pseudomonas fluorescens (n = 56), Pseudomonas putida (n = 63), Acinetobacter baumannii (n = 146), Acinetobacter lwoffii (n = 34), Burkholderia cepacia (n = 101), Stenotrophomonas maltophilia (n = 169), Bacteroides fragilis group (n = 196), and Prevotella/Porphyromonas (n = 173). An antibacterial activity of CZOP against E. coli, K. pneumoniae, K. oxytoca, and S. marcescens was potent and consistent with or more preferable than the study results obtained until the new drug application approval. MIC90 of CZOP against M.(B.) catarrhalis, C. koseri, and P. aeruginosa was not considerably changed and consistent with the study results obtained until the new drug application approval. MIC90 of CZOP against E. cloacae, E. aerogenes, and P. mirabilis increased year by year. The increase in MIC90 of CZOP against E. aerogenes and P. mirabilis, however, was not considered to be an obvious decline in susceptibility. In

Simultaneous inhibition of sulfate-reducing bacteria, removal of H2S and production of rhamnolipid by recombinant Pseudomonas stutzeri Rhl: Applications for microbial enhanced oil recovery.

PubMed

Zhao, Feng; Zhou, Ji-Dong; Ma, Fang; Shi, Rong-Jiu; Han, Si-Qin; Zhang, Jie; Zhang, Ying

2016-05-01

Sulfate-reducing bacteria (SRB) are widely existed in oil production system, and its H2S product inhibits rhamnolipid producing bacteria. In-situ production of rhamnolipid is promising for microbial enhanced oil recovery. Inhibition of SRB, removal of H2S and production of rhamnolipid by recombinant Pseudomonas stutzeri Rhl were investigated. Strain Rhl can simultaneously remove S(2-) (>92%) and produce rhamnolipid (>136mg/l) under S(2-) stress below 33.3mg/l. Rhl reduced the SRB numbers from 10(9) to 10(5)cells/ml, and the production of H2S was delayed and decreased to below 2mg/l. Rhl also produced rhamnolipid and removed S(2-) under laboratory simulated oil reservoir conditions. High-throughput sequencing data demonstrated that addition of strain Rhl significantly changed the original microbial communities of oilfield production water and decreased the species and abundance of SRB. Bioaugmentation of strain Rhl in oilfield is promising for simultaneous control of SRB, removal of S(2-) and enhance oil recovery. Copyright © 2016 Elsevier Ltd. All rights reserved.

Living on the edge: Emergence of spontaneous gac mutations in Pseudomonas protegens during swarming motility

USDA-ARS?s Scientific Manuscript database

Swarming motility is a flagella-driven multicellular behavior that allows bacteria to colonize new niches and escape competition. Here, we investigated the spatial distribution and evolution of ‘social cheaters’ in swarming colonies of Pseudomonas protegens Pf-5. Lipopeptide surfactants in the orfam...

Arsenic redox transformation by Pseudomonas sp. HN-2 isolated from arsenic-contaminated soil in Hunan, China.

PubMed

Zhang, Zhennan; Yin, Naiyi; Cai, Xiaolin; Wang, Zhenzhou; Cui, Yanshan

2016-09-01

A mesophilic, Gram-negative, arsenite[As(III)]-oxidizing and arsenate[As(V)]-reducing bacterial strain, Pseudomonas sp. HN-2, was isolated from an As-contaminated soil. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the strain was closely related to Pseudomonas stutzeri. Under aerobic conditions, this strain oxidized 92.0% (61.4μmol/L) of arsenite to arsenate within 3hr of incubation. Reduction of As(V) to As(III) occurred in anoxic conditions. Pseudomonas sp. HN-2 is among the first soil bacteria shown to be capable of both aerobic As(III) oxidation and anoxic As(V) reduction. The strain, as an efficient As(III) oxidizer and As(V) reducer in Pseudomonas, has the potential to impact arsenic mobility in both anoxic and aerobic environments, and has potential application in As remediation processes. Copyright © 2016. Published by Elsevier B.V.

Development of a selective agar plate for the detection of Campylobacter spp. in fresh produce.

PubMed

Yoo, Jin-Hee; Choi, Na-Young; Bae, Young-Min; Lee, Jung-Su; Lee, Sun-Young

2014-10-17

This study was conducted to develop a selective medium for the detection of Campylobacter spp. in fresh produce. Campylobacter spp. (n=4), non-Campylobacter (showing positive results on Campylobacter selective agar) strains (n=49) isolated from fresh produce, indicator bacteria (n=13), and spoilage bacteria isolated from fresh produce (n=15) were plated on four Campylobacter selective media. Bolton agar and modified charcoal cefoperazone deoxycholate agar (mCCDA) exhibited higher sensitivity for Campylobacter spp. than did Preston agar and Hunt agar, although certain non-Campylobacter strains isolated from fresh produce by using a selective agar isolation method, were still able to grow on Bolton agar and mCCDA. To inhibit the growth of non-Campylobacter strains, Bolton agar and mCCDA were supplemented with 5 antibiotics (rifampicin, polymyxin B, sodium metabisulfite, sodium pyruvate, ferrous sulfate) and the growth of Campylobacter spp. (n=7) and non-Campylobacter strains (n=44) was evaluated. Although Bolton agar supplemented with rifampicin (BR agar) exhibited a higher selectivity for Campylobacter spp. than did mCCDA supplemented with antibiotics, certain non-Campylobacter strains were still able to grow on BR agar (18.8%). When BR agar with various concentrations of sulfamethoxazole-trimethoprim were tested with Campylobacter spp. (n=8) and non-Campylobacter (n=7), sulfamethoxazole-trimethoprim was inhibitory against 3 of 7 non-Campylobacter strains. Finally, we validated the use of BR agar containing 50mg/L sulfamethoxazole (BRS agar) or 0.5mg/L ciprofloxacin (BRCS agar) and other selective agars for the detection of Campylobacter spp. in chicken and fresh produce. All chicken samples were positive for Campylobacter spp. when tested on mCCDA, BR agar, and BRS agar. In fresh produce samples, BRS agar exhibited the highest selectivity for Campylobacter spp., demonstrating its suitability for the detection of Campylobacter spp. in fresh produce. Copyright �

2D motility tracking of Pseudomonas putida KT2440 in growth phases using video microscopy

PubMed Central

Davis, Michael L.; Mounteer, Leslie C.; Stevens, Lindsey K.; Miller, Charles D.; Zhou, Anhong

2011-01-01

Pseudomonas putida KT2440 is a gram negative motile soil bacterium important in bioremediation and biotechnology. Thus, it is important to understand its motility characteristics as individuals and in populations. Population characteristics were determined using a modified Gompertz model. Video microscopy and imaging software were utilized to analyze two dimensional (2D) bacteria movement tracks to quantify individual bacteria behavior. It was determined that inoculum density increased the lag time as seeding densities decreased, and that the maximum specific growth rate decreased as seeding densities increased. Average bacterial velocity remained relatively similar throughout exponential growth phase (~20.9 µm/sec), while maximum velocities peak early in exponential growth phase at a velocity of 51.2 µm/sec. Pseudomonas putida KT2440 also favor smaller turn angles indicating they often continue in the same direction after a change in flagella rotation throughout the exponential growth phase. PMID:21334971

Molecular detection of six (endo-) symbiotic bacteria in Belgian mosquitoes: first step towards the selection of appropriate paratransgenesis candidates.

PubMed

Raharimalala, Fara Nantenaina; Boukraa, S; Bawin, T; Boyer, S; Francis, F

2016-04-01

Actually, the use of symbiotic bacteria is one of alternative solution to avoid vector resistance to pesticides. In Belgium, among 31 identified mosquito species, 10 were considered as potential vectors. Given to introduction risks of arbovirosis, the purpose of this study was to investigate the presence of symbiosis bacteria in potential mosquito vectors. Eleven species caught from 12 sites in Belgium were used: Culex pipiens s.l., Culex torrentium, Culex hortensis, Anopheles claviger, Anopheles maculipennis s.l., Anopheles plumbeus, Culiseta annulata, Ochlerotatus geniculatus, Ochlerotatus dorsalis, Aedes albopictus, and Coquillettidia richiardii. Six genera of symbiotic bacteria were screened: Wolbachia sp., Comamonas sp, Delftia sp., Pseudomonas sp., Acinetobacter sp., and Asaia sp. A total of 173 mosquito individuals (144 larvae and 29 adults) were used for the polymerase chain reaction screening. Wolbachia was not found in any Anopheles species nor Cx. torrentium. A total absence of Comamonas and Delftia was observed in all species. Acinetobacter, Pseudomonas, and Asaia were found in most of species with a high prevalence for Pseudomonas. These results were discussed to develop potential strategy and exploit the variable occurrence of symbiotic bacteria to focus on them to propose biological ways of mosquito control.

RELATIONSHIP BETWEEN CELL SURFACE PROPERTIES AND TRANSPORT OF BACTERIA THROUGH SOIL

EPA Science Inventory

A study was conducted to relate the properties of Enterobacter, Pseudomonas, Bacillus, Achromobacter, Flavobacterium, and Arthrobacter strains to their transport with water moving through soil. the bacteria differed markedly in their extent of transport; their hydrophobicity, as...

Pseudomonas aeruginosa KUN2, extracellular toxins-A potential source for the control of dengue vector.

PubMed

Lalithambika, B; Vani, C

2016-01-01

Dengue fever is one of the serious health disease transmitted by Aedes spp mosquitoes. The incidence of dengue has increased dramatically around the world in recent decades. Vector control is one of the important strategies practiced for the control of dengue fever. The emergence of resistance among vectors against the existing insecticides has raised new challenges. The aim of the present study was to identify the larvicidal activity of extracellular toxins from Pseudomonas spp for the control of dengue vector, Aedes aegypti. Bacterial isolates KUN1, KUN2, KUN3, KUN4, and KUBS were isolated from rhizosphere soil of the agricultural fields in Coimbatore, Tamil Nadu. Lyophilized culture supernatant of KUN2 (24, 48, and 72 h culture) and the solvent extracts from the diethyl ether, petroleum ether, chloroform and ethyl acetate were tested against the IV instar larvae of Ae. aegypti. Morphological and biochemical characterization of KUN2 showed its resemblance to Pseudomonas spp. Further, characterization by molecular methods confirmed it as Pseudomonas aeruginosa. Lyophilized culture supernatant of KUN2 showed more toxicity towards the larvae of Ae. aegypti when grown in the modified medium. Secondary metabolite from the petroleum ether extract was found more toxic to the Ae. aegypti larvae even at low concentration (50 μg/ml). The supernatant of 48 h culture of KUN2 recorded 100% larvicidal activity when compared to other isolates. Further, the rate of mortality was 100% at 24 h when treated with 100 μg/ml of petroleum ether extract of KUN2. Among the isolates used for the control of Ae. aegypti, the isolate KUN2 showed increased larvicidal activity when grown in the modified medium. The maximum larval mortality was observed in the solvent extract of petroleum ether. The mortality of the larvae might be due to the effect of the toxic compound present in the extract which would have entered the larvae through its cuticle damaging its whole system and obstructing

Evaluation of Animal and Plant Pathogens as Terrorism and Warfare Agents, Vectors and Pests

DTIC Science & Technology

2001-09-01

fever virus Bluetongue virus African horse sickness virus Nipah swine encephalitis virus Lumpy skin disease virus Camel pox virus Bacteria Bacillus...anthracis Bulkholderia (Pseudomonas) mallei Brucella spp. Mycoplasmas Contagious bovine (pleuropneum.) (M. mycoides var. mycoides type SC) (CBPP...virus Newcastle disease virus Rinderpest virus Pest des petits ruminants virus Bluetongue virus Teschen disease virus (Porcine enterovirus type 1) Rift

Screening for and isolation and identification of malathion-degrading bacteria: cloning and sequencing a gene that potentially encodes the malathion-degrading enzyme, carboxylestrase in soil bacteria.

PubMed

Goda, Sayed K; Elsayed, Iman E; Khodair, Taha A; El-Sayed, Walaa; Mohamed, Mervat E

2010-11-01

Five malathion-degrading bacterial strains were enriched and isolated from soil samples collected from different agricultural sites in Cairo, Egypt. Malathion was used as a sole source of carbon (50 mg/l) to enumerate malathion degraders, which were designated as IS1, IS2, IS3, IS4, and IS5. They were identified, based on their morphological and biochemical characteristics, as Pseudomonas sp., Pseudomonas putida, Micrococcus lylae, Pseudomonas aureofaciens, and Acetobacter liquefaciens, respectively. IS1 and IS2, which showed the highest degrading activity, were selected for further identification by partial sequence analysis of their 16S rRNA genes. The 16S rRNA gene of IS1 shared 99% similarity with that of Alphaprotoebacterium BAL284, while IS2 scored 100% similarity with that of Pseudomonas putida 32zhy. Malathion residues almost completely disappeared within 6 days of incubation in IS2 liquid cultures. LC/ESI-MS analysis confirmed the degradation of malathion to malathion monocarboxylic and dicarboxylic acids, which formed as a result of carboxylesterase activity. A carboxylesterase gene (CE) was amplified from the IS2 genome by using specifically designed PCR primers. The sequence analysis showed a significant similarity to a known CE gene in different Pseudomonas sp. We report here the isolation of a new malathion-degrading bacteria from soils in Egypt that may be very well adapted to the climatic and environmental conditions of the country. We also report the partial cloning of a new CE gene. Due to their high biodegradation activity, the bacteria isolated from this work merit further study as potential biological agents for the remediation of soil, water, or crops contaminated with the pesticide malathion.

[Mutant prevention concentrations of antibacterial agents to ocular pathogenic bacteria].

PubMed

Liang, Qing-Feng; Wang, Zhi-Qun; Li, Ran; Luo, Shi-Yun; Deng, Shi-Jing; Sun, Xu-Guang

2009-01-01

To establish a method to measure mutant prevention concentration (MPC) in vitro, and to measure MPC of antibacterial agents for ocular bacteria caused keratitis. It was an experimental study. Forty strains of ocular bacteria were separated from cornea in Beijing Institute of Ophthalmology, which included 8 strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Pseudomonas aeruginosa and Klebsiella pneumoniae respectively. The minimal inhibitory concentration (MIC) of the levofloxacin (LVF), ofloxacin (OFL), ciprofloxacin (CIP), norfloxacin (NFL), tobramycin (TOB) and chloromycetin (CHL) were determined by agar dilution method from National Committee of Clinical Laboratory Standard (NCCLS). The MPC were measured by accumulate-bacterial methods with bacterial population inoculated more than 1.2 x 10(10) colony forming units per milliliter with Mueller-Hinton broth and tryptic soy agar plate. With the software of SPSS 11.0, the datum such as the range of MIC, MPC, MIC90 and MPC90 were calculated, and the selection index (MPC90/ MI90) and mutant selection window (MSW) were obtained. The MI90 of LVF and TOB (4 mg/L) to Staphylococcus aureus strains were the lowest. CIP showed the lowest MIC90 (0.25 mg/L) to Pseudomonas aeruginosa among six kinds of antibacterial agents. The MIC90 of LVF to Staphylococcus epidermidis (256 mg/L), Streptococcus pneumoniae (1 mg/L) and Klebsiella pneumoniae (0.25 mg/L) were lower than other antibacterial agents. The MPC90, MSW and the MPC90/MIC90 of levofloxacin showed lower values compared with other antibacterial medicines. From all the datum, the MIC90 of CHL was the highest and the activity was the weakest. Although the activity of LVF was higher to every kind of bacteria, CIP had the highest activity antibacterial to Pseudomonas aeruginosa. The capacity of CHL and TOB was weaker than Quinolones for restricting resistant mutants on ocular bacteria. LVF had the strongest capacity for restricting resistant

Flies and their bacterial loads in greyhound dog kennels in Kansas.

PubMed

Urban, J E; Broce, A

1998-03-01

Breeders of greyhound dogs traditionally feed racing animals and nursing bitches raw meat, and that meat generally is obtained frozen from commercial renderers. Previous studies have shown that the rendered meat is frequently contaminated with enteric bacteria, including Salmonella spp., and that during thawing the rendered meat is exposed to filth flies common in dog kennels. Nursing greyhound pups tend to experience a high morbidity and mortality from intestinal infections, and we attempted to determine in this study whether enterics could be spread to pups through contaminated flies. At intervals during 1995 and 1996, flies were trapped or were net-collected from 10 dog breeding kennels in the region around Abilene, KS. Trapped flies were identified and counted to determine population numbers, and netted flies were cultured in tetrathionate broth and streaked to medium selecting for Salmonella sp. and other lactose-negative Gram (-) bacteria. The relative numbers of different fly species varied with the sampling method, but traps and sweep nets produced similar proportions of the different fly species. Blow flies were twice as likely to be contaminated with enteric bacteria as any other fly. The most common enteric bacteria found were Proteus spp., followed by Providencia spp., Pseudomonas spp., and Salmonella spp. The incidence of Salmonella and Proteus spp. seemed to correlate more with accessibility of flies to dog excrement than to rendered meat. The apparent high incidence of enteric contamination of filth flies clearly implicates them as vectors of enteric diseases in kennels.

Flagellation of Pseudomonas aeruginosa in newly divided cells

NASA Astrophysics Data System (ADS)

Zhao, Kun; Lee, Calvin; Anda, Jaime; Wong, Gerard

2015-03-01

For monotrichous bacteria, Pseudomonas aeruginosa, after cell division, one daughter cell inherits the old flagellum from its mother cell, and the other grows a new flagellum during or after cell division. It had been shown that the new flagellum grows at the distal pole of the dividing cell when the two daughter cells haven't completely separated. However, for those daughter cells who grow new flagella after division, it still remains unknown at which pole the new flagellum will grow. Here, by combining our newly developed bacteria family tree tracking techniques with genetic manipulation method, we showed that for the daughter cell who did not inherit the old flagellum, a new flagellum has about 90% chances to grow at the newly formed pole. We proposed a model for flagellation of P. aeruginosa.

Distribution and survival of Pseudomonas sp. on Italian ryegrass and Curly dock in Georgia

USDA-ARS?s Scientific Manuscript database

Yellow bud, caused by Pseudomonas sp. is an emerging bacterial disease of onion. Polymerase chain reaction (PCR) assay based on the coronafacate ligase (cfl) and HrpZ genes were used to detect initial suspected bacteria on weeds. Growth on an agar medium, ability to cause a hypersensitive response i...

Regulation of Pseudomonas aeruginosa chemotaxis by the nitrogen source.

PubMed Central

Craven, R; Montie, T C

1985-01-01

The regulation of amino acid chemotaxis by nitrogen was investigated in the gram-negative bacterium Pseudomonas aeruginosa. The quantitative capillary tube technique was used to measure chemotactic responses of bacteria to spatial gradients of amino acids and other attractants. Chemotaxis toward serine, arginine, and alpha-aminoisobutyrate was sharply dependent on the form in which nitrogen was presented to the bacteria. Bacteria grown on mineral salts-succinate with potassium nitrate gave responses to amino acids that were 2 to 3 times those of cells grown on ammonium sulfate and 10 to 20 times those of cells grown in mineral salts-succinate with Casamino Acids as the nitrogen source. A combination of ammonium sulfate and glutamate was as effective as Casamino Acids in depressing serine taxis. The threshold concentration for alpha-aminoisobutyrate taxis was consistently lower in nitrate-grown bacteria than in ammonia-grown bacteria. Responsiveness to sodium succinate, however, was not subject to regulation by nitrogen, and glucose chemotaxis was inhibited, rather than enhanced, in nitrate-grown bacteria. These results indicate that chemotaxis of P. aeruginosa toward amino acids is subject to regulation by nitrogen and that this regulation probably is expressed at the level of the chemoreceptors or transducers. PMID:3932326

Effect of high pressure treatment on microbiological quality of Indian white prawn (Fenneropenaeus indicus) during chilled storage.

PubMed

Ginson, J; Panda, Satyen Kumar; Bindu, J; Kamalakanth, C K; Srinivasa Gopal, T K

2015-04-01

High pressure treatment of 250 MPa for 6 min at 25 °C was applied to headless Indian white prawn (Fenneropenaeus indicus) to evaluate changes in microbiological characteristics of the species during chilled storage. Changes in load of mesophilic bacteria, psychrotrophic bacteria, proteolytic bacteria, Enterobacteriaceae, Pseudomonas spp., H2S producing bacteria, lactic acid bacteria, Brochothrix thermosphacta and yeast & mold were estimated in pressurized and un-pressurized samples during chilled storage. All microbes were reduced significantly after high pressure treatment and there was significant difference in microbial quality of control and high pressure treated samples in the entire duration of chilled storage (p < 0.05). There was delay in the growth of Enterobacteriaceae and H2S producing bacteria up to 6th and 9th day of storage, respectively in high pressure treated samples. In high pressure treated sample, no lag phase (λ) was observed for psychrotrophic bacteria, H2S producing bacteria, B. thermosphacta, Pseudomonas spp. and lactic acid bacteria; however, other bacteria showed a reduced lag phase during chilled storage. Kinetic parameter such as specific growth rate (μmax) in high pressure treated samples was significantly reduced in most of the bacterial groups except for psychrotrophic bacteria, Enterobacteriaceae and lactic acid bacteria. Mesophilic bacterial count of control samples crossed the marginal limit of acceptability on 12th day and unacceptable limit on 18th day of storage, whereas high pressure treated samples never breached the acceptability limit during entire duration of chilled storage. The present study indicated that application of high pressure processing can be used to improve microbial quality of Indian white prawn and extend the chilled storage life. Copyright © 2014 Elsevier Ltd. All rights reserved.

The analysis of milk components and pathogenic bacteria isolated from bovine raw milk in Korea.

PubMed

Park, Y K; Koo, H C; Kim, S H; Hwang, S Y; Jung, W K; Kim, J M; Shin, S; Kim, R T; Park, Y H

2007-12-01

Bovine mastitis can be diagnosed by abnormalities in milk components and somatic cell count (SCC), as well as by clinical signs. We examined raw milk in Korea by analyzing SCC, milk urea nitrogen (MUN), and the percentages of milk components (milk fat, protein, and lactose). The associations between SCC or MUN and other milk components were investigated, as well as the relationships between the bacterial species isolated from milk. Somatic cell counts, MUN, and the percentages of milk fat, protein, and lactose were analyzed in 30,019 raw milk samples collected from 2003 to 2006. The regression coefficients of natural logarithmic-transformed SCC (SCCt) on milk fat (-0.0149), lactose (-0.8910), and MUN (-0.0096), and those of MUN on milk fat (-0.3125), protein (-0.8012), and SCCt (-0.0671) were negative, whereas the regression coefficient of SCCt on protein was positive (0.3023). When the data were categorized by the presence or absence of bacterial infection in raw milk, SCCt was negatively associated with milk fat (-0.0172), protein (-0.2693), and lactose (-0.4108). The SCCt values were significantly affected by bacterial species. In particular, 104 milk samples infected with Staphylococcus aureus had the highest SCCt (1.67) compared with milk containing other mastitis-causing bacteria: coagulase-negative staphylococci (n = 755, 1.50), coagulase-positive staphylococci (except Staphylococcus aureus; n = 77, 1.59), Streptococcus spp. (Streptococcus dysgalactiae, n = 37; Streptococcus uberis, n = 12, 0.83), Enterococcus spp. (n = 46, 1.04), Escherichia coli (n = 705, 1.56), Pseudomonas spp. (n = 456, 1.59), and yeast (n = 189, 1.52). These results show that high SCC and MUN negatively affect milk components and that a statistical approach associating SCC, MUN, and milk components by bacterial infection can explain the patterns among them. Bacterial species present in raw milk are an important influence on SCC in Korea.