Plastic potential: how the phenotypes and adaptations of pathogens are influenced by microbial interactions within plants.

Science.gov (United States)

O'Keeffe, Kayleigh R; Carbone, Ignazio; Jones, Corbin D; Mitchell, Charles E

2017-08-01

Predicting the effects of plant-associated microbes on emergence, spread, and evolution of plant pathogens demands an understanding of how pathogens respond to these microbes at two levels of biological organization: that of an individual pathogen and that of a pathogen population across multiple individual plants. We first examine the plastic responses of individual plant pathogens to microbes within a shared host, as seen through changes in pathogen growth and multiplication. We then explore the limited understanding of how within-plant microbial interactions affect pathogen populations and discuss the need to incorporate population-level observations with population genomic techniques. Finally, we suggest that integrating across levels will further our understanding of the ecological and evolutionary impacts of within-plant microbial interactions on pathogens. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pathogenicity of Metarrhizium anisopliae (Metsch.) Sorokin and Beauveria bassiana (Bals.) Vuillemin isolates to Scaptocoris carvalhoi Becker (Hemiptera, Cydnidae)

International Nuclear Information System (INIS)

Xavier, Luciane Modenez Saldivar; Avila, Crebio Jose

2006-01-01

Pathogenicity of the fungi Metarrhizium anisopliae (Metsch.) Sorokin and Beauveria bassiana (Bals.) Vuillemin to stink bug Scaptocoris carvalhoi Becker, 1967 was evaluated under laboratory and greenhouse conditions. Experiments were carried out at EMBRAPA Agropecuaria Oeste, Dourados, Mato Grosso do Sul State, Brazil, in 2003. Ten M. anisopliae and eleven B. bassiana isolates were evaluated in laboratory using a completely randomized experimental design with five replicates (10 adults and 5 nymphs/plot). The pathogenicity of M. anisopliae isolate (Ma69) was also separately evaluated against nymphs and adults in laboratory and greenhouse. The stink bug mortality levels were higher for M. anisopliae isolates (between 73.3% and 94.7% than for B. bassiana isolates (between 10.7% and 78.7%). In greenhouse, stink bug mortality due to the M. anisopliae isolate (Ma69) was 57.3%, and there was no difference of mortality for nymphs and adults of stink bug in laboratory. However, in greenhouse, mortality levels were significantly higher (p<0,05) for nymphs (38,4%) than for adults (16,2%). From these data, we conclude that M. anisopliae isolate Ma69 was efficient to control S. carvalhoi in laboratory and in greenhouse, thus being a promising choice for use as a microbial insecticide under field conditions. (author)

Biological activity of the non-microbial fraction of kefir: antagonism against intestinal pathogens.

Science.gov (United States)

Iraporda, Carolina; Abatemarco Júnior, Mário; Neumann, Elisabeth; Nunes, Álvaro Cantini; Nicoli, Jacques R; Abraham, Analía G; Garrote, Graciela L

2017-08-01

Kefir is a fermented milk obtained by the activity of kefir grains which are composed of lactic and acetic acid bacteria, and yeasts. Many beneficial health effects have been associated with kefir consumption such as stimulation of the immune system and inhibition of pathogenic microorganisms. The biological activity of kefir may be attributed to the presence of a complex microbiota as well as the microbial metabolites that are released during fermentation. The aim of this work was to characterise the non-microbial fraction of kefir and to study its antagonism against Escherichia coli, Salmonella spp. and Bacillus cereus. During milk fermentation there was a production of organic acids, mainly lactic and acetic acid, with a consequent decrease in pH and lactose content. The non-microbial fraction of kefir added to nutrient broth at concentrations above 75% v/v induced a complete inhibition of pathogenic growth that could be ascribed to the presence of un-dissociated lactic acid. In vitro assays using an intestinal epithelial cell model indicated that pre-incubation of cells with the non-microbial fraction of kefir did not modify the association/invasion of Salmonella whereas pre-incubation of Salmonella with this fraction under conditions that did not affect their viability significantly decreased the pathogen's ability to invade epithelial cells. Lactate exerted a protective effect against Salmonella in a mouse model, demonstrating the relevance of metabolites present in the non-microbial fraction of kefir produced during milk fermentation.

Pathogenic diversity of Sclerotium rolfsii isolates, a potential ...

African Journals Online (AJOL)

Administrator

et al., 2002; Shukla and Pandey, 2007). Therefore, present investigation was carried out to study the pathogenic varia- bility and justify the separate identity of the S. rolfsii isolates associated with Parthenium. MATERIALS AND METHODS. Test isolates and their maintenance. Ten isolates of S. rolfsii incites collar rot disease ...

Isolation and application of hydrocarbon degradation of indigenous microbial from oil contaminated soil

International Nuclear Information System (INIS)

Dadang Sudrajat; Nana Mulyana; Tri Retno DL

2015-01-01

The aims of this research are to obtain indigenous potential microbes from bacterial and fungal groups which have capable of degrading hydrocarbon from crude oil contaminated soil. The research carried out were isolation, selection, and identification potential microbial isolates capable of degrading hydrocarbon from oil contaminated soil located at Cepu East Java. The isolates were tested for their growth and ability to degrades crude oil. Each isolate was inoculated unto minimum mineral salt medium (MSM) contained 1% crude oil. Viability and stability test of selected isolates were carried out on irradiated compost carrier materials contained 5% crude oil. The fours series microbial s consortium consists of microbial consortium I, II, III, and IV were tested for the in vitro biodegradability of hydrocarbon. The results shows there sixty two (62) isolates are obtained, among them 42 bacteria and 20 molds. From 42 bacterial isolates, only 8 strains were potent hydrocarbon degraders. Three of these isolates are identified Bacillus cereus (BMC2), Bacillus sp (BMC4), and Pseudomonas sp (BMC6). Whereas from 20 fungal isolates, only 4 strains were potent hydrocarbon degraders. Two of these isolates are identified Aspergillus fumigatus (FMC2) and Aspergillus niger (FMC6). All isolates show good growth in mineral salt medium contained crude oil with decrease in pH. The ability of decrease of TPH content by the bacterial and fungal isolates were 54, 61, 67, 74, and 78% respectively at day 30. The viability and stability of microbial isolates show considerable good viability on irradiated compost carrier materials after 14 days storage. From the fours series microbial consortium, the highest TPH degradation rates is found in microbial consortium III (BMC6, BMC2, and FMC6) with 89,1% in 5 weeks. (author)

Assessing the Consequences of Microbial Infection in Field Trials: Seen, Unseen, Beneficial, Parasitic and Pathogenic

Directory of Open Access Journals (Sweden)

Mark E. Looseley

2014-06-01

Full Text Available Microbial infections of crop plants present an ongoing threat to agricultural production. However, in recent years, we have developed a more nuanced understanding of the ecological role of microbes and how they interact with plants. This includes an appreciation of the influence of crop physiology and environmental conditions on the expression of disease symptoms, the importance of non-pathogenic microbes on host plants and pathogens, and the capacity for plants to act as hosts for human pathogens. Alongside this we now have a variety of tools available for the identification and quantification of microbial infections on crops grown under field conditions. This review summarises some of the consequences of microbial infections in crop plants, and discusses how new and established assessment tools can be used to understand these processes. It challenges our current assumptions in yield loss relationships and offers understanding of the potential for more resilient crops.

Isolation of pathogenic Escherichia coli from buffalo meat sold in Parbhani city, Maharashtra, India

Directory of Open Access Journals (Sweden)

M. S. Vaidya

2013-10-01

Full Text Available Aim: Isolation, characterization, in-vitro pathogenicity and antibiogram study of E.coli from buffalo meat sold in Parbhani city. Materials and Methods: Meat samples were collected from buffalo immediately after slaughter. Isolation, identification and enumeration of E. coli were done by following standard methods and protocols. Hemolysin test and Congo red binding assay were used to study in-vitro pathogenicity of E. coli isolates. Disc diffusion method was used to study antibiogram of pathogenic E. coli isolates. Results: A total of 250 buffalo meat samples were collected and processed. A total of 22 (8.80 percent E. coli isolates were isolated with average differential count of 1.231 ± 0.136 log cfu/g on EMB agar. All the E. coli isolates were confirmed by 10 Grams staining, biochemical reactions and sugar fermentation and motility tests. A total of 9 (3.6 percent E. coli isolates were found to be pathogenic by in-vitro pathogenicity testing. Antibiogram studies of pathogenic E. coli isolates showed that all 9 isolates were sensitive to gentamycin (20 ± 1.49 mm while 7 isolate showed resistance to enrofloxacin (18.22 ± 3.58 mm and tetracycline (11.44 ± 2.04 mm. Conclusion: Buffalo meat sold in Parbhani city is an important source of E. coli infection to human population. A total of 9 pathogenic E. coli were isolated from buffalo meat immediately after slaughter. All isolates were characterized and confirmed pathogenic by in-vitro pathogenicity tests. Antibiogram studies of all isolates revealed sensitivity to gentamicin and resistance to tetracycline and enrofloxacin. [Vet World 2013; 6(5.000: 277-279

Biomimicry of volatile-based microbial control for managing emerging fungal pathogens.

Science.gov (United States)

Gabriel, K T; Joseph Sexton, D; Cornelison, C T

2018-05-01

Volatile organic compounds (VOCs) are known to be produced by a wide range of micro-organisms and for a number of purposes. Volatile-based microbial inhibition in environments such as soil is well-founded, with numerous antimicrobial VOCs having been identified. Inhibitory VOCs are of interest as microbial control agents, as low concentrations of gaseous VOCs can elicit significant antimicrobial effects. Volatile organic compounds are organic chemicals typically characterized as having low molecular weight, low solubility in water, and high vapour pressure. Consequently, VOCs readily evaporate to the gaseous phase at standard temperature and pressure. This contact-independent antagonism presents unique advantages over traditional, contact-dependent microbial control methods, including increased surface exposure and reduced environmental persistence. This approach has been the focus of our recent research, with positive results suggesting it may be particularly promising for the management of emerging fungal pathogens, such as the causative agents of white-nose syndrome of bats and snake fungal disease, which are difficult or impossible to treat using traditional approaches. Here, we review the history of volatile-based microbial control, discuss recent progress in formulations that mimic naturally antagonistic VOCs, outline the development of a novel treatment device, and highlight areas where further work is needed to successfully deploy VOCs against existing and emerging fungal pathogens. © 2017 The Society for Applied Microbiology.

Investigating the Swimming of Microbial Pathogens Using Digital Holography.

Science.gov (United States)

Thornton, K L; Findlay, R C; Walrad, P B; Wilson, L G

2016-01-01

To understand much of the behaviour of microbial pathogens, it is necessary to image living cells, their interactions with each other and with host cells. Species such as Escherichia coli are difficult subjects to image: they are typically microscopic, colourless and transparent. Traditional cell visualisation techniques such as fluorescent tagging or phase-contrast microscopy give excellent information on cell behaviour in two dimensions, but no information about cells moving in three dimensions. We review the use of digital holographic microscopy for three-dimensional imaging at high speeds, and demonstrate its use for capturing the shape and swimming behaviour of three important model pathogens: E. coli, Plasmodium spp. and Leishmania spp.

Overcoming antibiotic resistance: Is siderophore Trojan horse conjugation an answer to evolving resistance in microbial pathogens?

Science.gov (United States)

Dhusia, Kalyani; Bajpai, Archana; Ramteke, P W

2018-01-10

Comparative study of siderophore biosynthesis pathway in pathogens provides potential targets for antibiotics and host drug delivery as a part of computationally feasible microbial therapy. Iron acquisition using siderophore models is an essential and well established model in all microorganisms and microbial infections a known to cause great havoc to both plant and animal. Rapid development of antibiotic resistance in bacterial as well as fungal pathogens has drawn us at a verge where one has to get rid of the traditional way of obstructing pathogen using single or multiple antibiotic/chemical inhibitors or drugs. 'Trojan horse' strategy is an answer to this imperative call where antibiotic are by far sneaked into the pathogenic cell via the siderophore receptors at cell and outer membrane. This antibiotic once gets inside, generates a 'black hole' scenario within the opportunistic pathogens via iron scarcity. For pathogens whose siderophore are not compatible to smuggle drug due to their complex conformation and stiff valence bonds, there is another approach. By means of the siderophore biosynthesis pathways, potential targets for inhibition of these siderophores in pathogenic bacteria could be achieved and thus control pathogenic virulence. Method to design artificial exogenous siderophores for pathogens that would compete and succeed the battle of intake is also covered with this review. These manipulated siderophore would enter pathogenic cell like any other siderophore but will not disperse iron due to which iron inadequacy and hence pathogens control be accomplished. The aim of this review is to offer strategies to overcome the microbial infections/pathogens using siderophore. Copyright © 2017 Elsevier B.V. All rights reserved.

Ecosystem screening approach for pathogen-associated microorganisms affecting host disease.

Science.gov (United States)

Galiana, Eric; Marais, Antoine; Mura, Catherine; Industri, Benoît; Arbiol, Gilles; Ponchet, Michel

2011-09-01

The microbial community in which a pathogen evolves is fundamental to disease outcome. Species interacting with a pathogen on the host surface shape the distribution, density, and genetic diversity of the inoculum, but the role of these species is rarely determined. The screening method developed here can be used to characterize pathogen-associated species affecting disease. This strategy involves three steps: (i) constitution of the microbial community, using the pathogen as a trap; (ii) community selection, using extracts from the pathogen as the sole nutrient source; and (iii) molecular identification and the screening of isolates focusing on their effects on the growth of the pathogen in vitro and host disease. This approach was applied to a soilborne plant pathogen, Phytophthora parasitica, structured in a biofilm, for screening the microbial community from the rhizosphere of Nicotiana tabacum (the host). Two of the characterized eukaryotes interfered with the oomycete cycle and may affect the host disease. A Vorticella species acted through a mutualistic interaction with P. parasitica, disseminating pathogenic material by leaving the biofilm. A Phoma species established an amensal interaction with P. parasitica, strongly suppressing disease by inhibiting P. parasitica germination. This screening method is appropriate for all nonobligate pathogens. It allows the definition of microbial species as promoters or suppressors of a disease for a given biotope. It should also help to identify important microbial relationships for ecology and evolution of pathogens.

Carbapenem-resistance and pathogenicity of bovine Acinetobacter indicus-like isolates.

Directory of Open Access Journals (Sweden)

Peter Klotz

Full Text Available The objective of this study was to characterize blaOXA-23 harbouring Acinetobacter indicus-like strains from cattle including genomic and phylogenetic analyses, antimicrobial susceptibility testing and evaluation of pathogenicity in vitro and in vivo. Nasal and rectal swabs (n = 45 from cattle in Germany were screened for carbapenem-non-susceptible Acinetobacter spp. Thereby, two carbapenem resistant Acinetobacter spp. from the nasal cavities of two calves could be isolated. MALDI-TOF mass spectrometry and 16S rDNA sequencing identified these isolates as A. indicus-like. A phylogenetic tree based on partial rpoB sequences indicated closest relation of the two bovine isolates to the A. indicus type strain A648T and human clinical A. indicus isolates, while whole genome comparison revealed considerable intraspecies diversity. High mimimum inhibitory concentrations were observed for carbapenems and other antibiotics including fluoroquinolones and gentamicin. Whole genome sequencing and PCR mapping revealed that both isolates harboured blaOXA-23 localized on the chromosome and surrounded by interrupted Tn2008 transposon structures. Since the pathogenic potential of A. indicus is unknown, pathogenicity was assessed employing the Galleria (G. mellonella infection model and an in vitro cytotoxicity assay using A549 human lung epithelial cells. Pathogenicity in vivo (G. mellonella killing assay and in vitro (cytotoxicity assay of the two A. indicus-like isolates was lower compared to A. baumannii ATCC 17978 and similar to A. lwoffii ATCC 15309. The reduced pathogenicity of A. indicus compared to A. baumannii correlated with the absence of important virulence genes encoding like phospholipase C1+C2, acinetobactin outer membrane protein BauA, RND-type efflux system proteins AdeRS and AdeAB or the trimeric autotransporter adhesin Ata. The emergence of carbapenem-resistant A. indicus-like strains from cattle carrying blaOXA-23 on transposable elements and

Isolation and identification of bacterial pathogen from mastitis milk in Central Java Indonesia

Science.gov (United States)

Harjanti, D. W.; Ciptaningtyas, R.; Wahyono, F.; Setiatin, ET

2018-01-01

Mastitis is a multi-etiologic disease of the mammary gland characterized mainly by reduction in milk production and milk quality due to intramammary infection by pathogenic bacteria. Nearly 83% of lactating dairy cows in Indonesia are infected with mastitis in various inflammation degrees. This study was conducted to isolate and identify the pathogen in milk collected from mastitis-infected dairy cows. The study was carried out in ten smallholder dairy farms in Central Java Indonesia based on animal examination, California mastitis test, isolation bacterial pathogens, Gram staining, Catalase and Coagulase test, and identification of bacteria species using Vitek. Bacteriological examination of milk samples revealed 15 isolates where Streptococcus was predominant species (73.3%) and the coagulase negative Staphylococcus species was identified at the least bacteria (26.7%). The Streptococcus bacteria found were Streptococcus uberis (2 isolates), Streptococcus sanguinis(6 isolates), Streptococcus dysgalactiaessp dysgalactiae(1 isolate) , Streptococcus mitis (1 isolate) and Streptococcus agalactiae (1 isolate). The Staphylococcus isolates comprising of Staphylococcus simulans (1 isolate) and Staphylococcus chromogens (3 isolates). Contamination of raw milkwith pathogenic bacteria can cause outbreaks of human disease (milk borne disease). Thus, proper milk processing method that couldinhibit the growth or kill these pathogenic bacteria is important to ensure the safety of milk and milk products.

Sequestered Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio Provide Variable Protection from Microbial Pathogens.

Science.gov (United States)

Hovey, Kyle J; Seiter, Emily M; Johnson, Erin E; Saporito, Ralph A

2018-03-01

Most amphibians produce their own defensive chemicals; however, poison frogs sequester their alkaloid-based defenses from dietary arthropods. Alkaloids function as a defense against predators, and certain types appear to inhibit microbial growth. Alkaloid defenses vary considerably among populations of poison frogs, reflecting geographic differences in availability of dietary arthropods. Consequently, environmentally driven differences in frog defenses may have significant implications regarding their protection against pathogens. While natural alkaloid mixtures in dendrobatid poison frogs have recently been shown to inhibit growth of non-pathogenic microbes, no studies have examined the effectiveness of alkaloids against microbes that infect these frogs. Herein, we examined how alkaloid defenses in the dendrobatid poison frog, Oophaga pumilio, affect growth of the known anuran pathogens Aeromonas hydrophila and Klebsiella pneumoniae. Frogs were collected from five locations throughout Costa Rica that are known to vary in their alkaloid profiles. Alkaloids were isolated from individual skins, and extracts were assayed against both pathogens. Microbe subcultures were inoculated with extracted alkaloids to create dose-response curves. Subsequent spectrophotometry and cell counting assays were used to assess growth inhibition. GC-MS was used to characterize and quantify alkaloids in frog extracts, and our results suggest that variation in alkaloid defenses lead to differences in inhibition of these pathogens. The present study provides the first evidence that alkaloid variation in a dendrobatid poison frog is associated with differences in inhibition of anuran pathogens, and offers further support that alkaloid defenses in poison frogs confer protection against both pathogens and predators.

Model-Based Analysis of the Potential of Macroinvertebrates as Indicators for Microbial Pathogens in Rivers

Directory of Open Access Journals (Sweden)

Rubén Jerves-Cobo

2018-03-01

Full Text Available The quality of water prior to its use for drinking, farming or recreational purposes must comply with several physicochemical and microbiological standards to safeguard society and the environment. In order to satisfy these standards, expensive analyses and highly trained personnel in laboratories are required. Whereas macroinvertebrates have been used as ecological indicators to review the health of aquatic ecosystems. In this research, the relationship between microbial pathogens and macrobenthic invertebrate taxa was examined in the Machangara River located in the southern Andes of Ecuador, in which 33 sites, according to their land use, were chosen to collect physicochemical, microbiological and biological parameters. Decision tree models (DTMs were used to generate rules that link the presence and abundance of some benthic families to microbial pathogen standards. The aforementioned DTMs provide an indirect, approximate, and quick way of checking the fulfillment of Ecuadorian regulations for water use related to microbial pathogens. The models built and optimized with the WEKA package, were evaluated based on both statistical and ecological criteria to make them as clear and simple as possible. As a result, two different and reliable models were obtained, which could be used as proxy indicators in a preliminary assessment of pollution of microbial pathogens in rivers. The DTMs can be easily applied by staff with minimal training in the identification of the sensitive taxa selected by the models. The presence of selected macroinvertebrate taxa in conjunction with the decision trees can be used as a screening tool to evaluate sites that require additional follow up analyses to confirm whether microbial water quality standards are met.

PATHOGENIC POTENTIALS OF ESCHERICHIA COLI ISOLATED ...

African Journals Online (AJOL)

Electrolyte and haematological parameters in rabbits infected with pathogenic isolates of Escherichia coli from rural water supplies in Rivers State, Nigeria, where monitored. Rabbits were orally infected with suspension containing 3x107 cfu /ml of Escherichia coli to induce diarrhoea, and the electrolyte (sodium, potassium ...

Volatile-mediated suppression of plant pathogens is related to soil properties and microbial community composition

NARCIS (Netherlands)

Van Agtmaal, M.; Straathof, A.L.; Termorshuizen, Aad J; Lievens, Bart; Hoffland, Ellis; De Boer, W.

2018-01-01

There is increasing evidence that the soil microbial community produces a suite of volatile organic compounds that suppress plant pathogens. However, it remains unknown which soil properties and management practices influence volatile-mediated pathogen suppression. The aim of this study was to

Volatile-mediated suppression of plant pathogens is related to soil properties and microbial community composition

NARCIS (Netherlands)

Agtmaal, van Maaike; Straathof, Angela L.; Termorshuizen, Aad; Lievens, Bart; Hoffland, Ellis; Boer, de Wietse

2018-01-01

There is increasing evidence that the soil microbial community produces a suite of volatile organic compounds that suppress plant pathogens. However, it remains unknown which soil properties and management practices influence volatile-mediated pathogen suppression. The aim of this study was to

Pathogenicity of Human ST23 Streptococcus agalactiae to Fish and Genomic Comparison of Pathogenic and Non-pathogenic Isolates

Directory of Open Access Journals (Sweden)

Rui Wang

2017-10-01

Full Text Available Streptococcus agalactiae, or Group B Streptococcus (GBS, is a major pathogen causing neonatal sepsis and meningitis, bovine mastitis, and fish meningoencephalitis. CC23, including its namesake ST23, is not only the predominant GBS strain derived from human and cattle, but also can infect a variety of homeothermic and poikilothermic species. However, it has never been characterized in fish. This study aimed to determine the pathogenicity of ST23 GBS to fish and explore the mechanisms causing the difference in the pathogenicity of ST23 GBS based on the genome analysis. Infection of tilapia with 10 human-derived ST23 GBS isolates caused tissue damage and the distribution of pathogens within tissues. The mortality rate of infection was ranged from 76 to 100%, and it was shown that the mortality rate caused by only three human isolates had statistically significant difference compared with fish-derived ST7 strain (P < 0.05, whereas the mortality caused by other seven human isolates did not show significant difference compared with fish-derived ST7 strain. The genome comparison and prophage analysis showed that the major genome difference between virulent and non-virulent ST23 GBS was attributed to the different prophage sequences. The prophage in the P1 region contained about 43% GC and encoded 28–39 proteins, which can mediate the acquisition of YafQ/DinJ structure for GBS by phage recombination. YafQ/DinJ belongs to one of the bacterial toxin–antitoxin (TA systems and allows cells to cope with stress. The ST23 GBS strains carrying this prophage were not pathogenic to tilapia, but the strains without the prophage or carrying the pophage that had gene mutation or deletion, especially the deletion of YafQ/DinJ structure, were highly pathogenic to tilapia. In conclusion, human ST23 GBS is highly pathogenic to fish, which may be related to the phage recombination.

Disease induction by human microbial pathogens in plant-model systems: potential, problems and prospects.

Science.gov (United States)

van Baarlen, Peter; van Belkum, Alex; Thomma, Bart P H J

2007-02-01

Relatively simple eukaryotic model organisms such as the genetic model weed plant Arabidopsis thaliana possess an innate immune system that shares important similarities with its mammalian counterpart. In fact, some human pathogens infect Arabidopsis and cause overt disease with human symptomology. In such cases, decisive elements of the plant's immune system are likely to be targeted by the same microbial factors that are necessary for causing disease in humans. These similarities can be exploited to identify elementary microbial pathogenicity factors and their corresponding targets in a green host. This circumvents important cost aspects that often frustrate studies in humans or animal models and, in addition, results in facile ethical clearance.

Influence of secondary water supply systems on microbial community structure and opportunistic pathogen gene markers.

Science.gov (United States)

Li, Huan; Li, Shang; Tang, Wei; Yang, Yang; Zhao, Jianfu; Xia, Siqing; Zhang, Weixian; Wang, Hong

2018-06-01

Secondary water supply systems (SWSSs) refer to the in-building infrastructures (e.g., water storage tanks) used to supply water pressure beyond the main distribution systems. The purpose of this study was to investigate the influence of SWSSs on microbial community structure and the occurrence of opportunistic pathogens, the latter of which are an emerging public health concern. Higher numbers of bacterial 16S rRNA genes, Legionella and mycobacterial gene markers were found in public building taps served by SWSSs relative to the mains, regardless of the flushing practice (P water retention time, warm temperature and loss of disinfectant residuals promoted microbial growth and colonization of potential pathogens in SWSSs. Varied levels of microbial community shifts were found in different types of SWSSs during water transportation from the distribution main to taps, highlighting the critical role of SWSSs in shaping the drinking water microbiota. Overall, the results provided insight to factors that might aid in controlling pathogen proliferation in real-world water systems using SWSSs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of isolation methods for pathogenic Yersinia enterocolitica from pig intestinal content.

Science.gov (United States)

Laukkanen, R; Hakkinen, M; Lundén, J; Fredriksson-Ahomaa, M; Johansson, T; Korkeala, H

2010-03-01

The aim of this study was to evaluate the efficiency of four isolation methods for the detection of pathogenic Yersinia enterocolitica from pig intestinal content. The four methods comprised of 15 isolation steps using selective enrichments (irgasan-ticarcillin-potassium chlorate and modified Rappaport broth) and mildly selective enrichments at 4 or 25 degrees C. Salmonella-Shigella-desoxycholate-calcium chloride agar, cefsulodin-irgasan-novobiocin agar were used as plating media. The most sensitive method detected 78% (53/68) of the positive samples. Individual isolation steps using cold enrichment as the only enrichment or as a pre-enrichment step with further selective enrichment showed the highest sensitivities (55-66%). All isolation methods resulted in high numbers of suspected colonies not confirmed as pathogenic Y. enterocolitica. Cold enrichment should be used in the detection of pathogenic Y. enterocolitica from pig intestinal contents. In addition, more than one parallel isolation step is needed. The study shows that depending on the isolation method used for Y. enterocolitica, the detected prevalence of Y. enterocolitica in pig intestinal contents varies greatly. More selective and sensitive isolation methods need to be developed for pathogenic Y. enterocolitica.

Anti-Microbial Resistance Profiles Of E. Coli Isolated From Free Range Chickens In Urban And Rural Environments Of Imo State, Nigeria

OpenAIRE

Okoli I, Dr. Charles

2006-01-01

Information on the resistance profiles of normal intestinal flora of extensively reared chickens that hardly receive antibiotics in the developing countries can serve as important means of understanding the human/animal pathogens drug resistance interactions in the zone. Three hundred and fifty E. coli isolates, comprising 133 from urban and 217 from rural sites in Imo state, Nigeria, were screened for anti-microbial resistance profile against 10 antibiotics using the disc diffusion method. O...

Global Warming and Trans-Boundary Movement of Waterborne Microbial Pathogens - Book Chapter

Science.gov (United States)

Subtle increases in temperature can have profound impacts on the prevalence of various waterborne microbial pathogens. Such impacts may be seen in three major areas, 1) fecally contaminated drinking water, 2) fresh produce that has been irrigated or processed with contaminated wa...

Management of microbial food safety in Arab countries.

Science.gov (United States)

Kamleh, Rabih; Jurdi, Mey; Annous, Bassam A

2012-11-01

Microbial food safety remains a major economic and public health concern in Arab countries. Over the past several years, many of these countries have attempted to revise and upgrade food quality control and surveillance programs; however, these systems vary in scope and effectiveness. This review addresses the major reported foodborne outbreaks and multidrug resistance of pathogenic microorganisms isolated from food products. Major foodborne pathogens of concern included Brucella spp., Clostridium botulinum, fecal coliforms, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella, and Staphylococcus aureus. Measures for managing microbial food hazards based on a comprehensive risk analysis also are proposed.

HSQC-TOCSY Fingerprinting for Prioritization of Polyketide- and Peptide-Producing Microbial Isolates.

Science.gov (United States)

Buedenbender, Larissa; Habener, Leesa J; Grkovic, Tanja; Kurtböke, D İpek; Duffy, Sandra; Avery, Vicky M; Carroll, Anthony R

2018-04-27

Microbial products are a promising source for drug leads as a result of their unique structural diversity. However, reisolation of already known natural products significantly hampers the discovery process, and it is therefore important to incorporate effective microbial isolate selection and dereplication protocols early in microbial natural product studies. We have developed a systematic approach for prioritization of microbial isolates for natural product discovery based on heteronuclear single-quantum correlation-total correlation spectroscopy (HSQC-TOCSY) nuclear magnetic resonance profiles in combination with antiplasmodial activity of extracts. The HSQC-TOCSY experiments allowed for unfractionated microbial extracts containing polyketide and peptidic natural products to be rapidly identified. Here, we highlight how this approach was used to prioritize extracts derived from a library of 119 ascidian-associated actinomycetes that possess a higher potential to produce bioactive polyketides and peptides.

Opportunistic Pathogens and Microbial Communities and Their Associations with Sediment Physical Parameters in Drinking Water Storage Tank Sediments

Science.gov (United States)

Qin, Ke; Struewing, Ian; Domingo, Jorge Santo; Lytle, Darren

2017-01-01

The occurrence and densities of opportunistic pathogens (OPs), the microbial community structure, and their associations with sediment elements from eight water storage tanks in Ohio, West Virginia, and Texas were investigated. The elemental composition of sediments was measured through X-ray fluorescence (XRF) spectra. The occurrence and densities of OPs and amoeba hosts (i.e., Legionella spp. and L. pneumophila, Mycobacterium spp., P. aeruginosa, V. vermiformis, Acanthamoeba spp.) were determined using genus- or species-specific qPCR assays. Microbial community analysis was performed using next generation sequencing on the Illumina Miseq platform. Mycobacterium spp. were most frequently detected in the sediments and water samples (88% and 88%), followed by Legionella spp. (50% and 50%), Acanthamoeba spp. (63% and 13%), V. vermiformis (50% and 25%), and P. aeruginosa (0 and 50%) by qPCR method. Comamonadaceae (22.8%), Sphingomonadaceae (10.3%), and Oxalobacteraceae (10.1%) were the most dominant families by sequencing method. Microbial communities in water samples were mostly separated with those in sediment samples, suggesting differences of communities between two matrices even in the same location. There were associations of OPs with microbial communities. Both OPs and microbial community structures were positively associated with some elements (Al and K) in sediments mainly from pipe material corrosions. Opportunistic pathogens presented in both water and sediments, and the latter could act as a reservoir of microbial contamination. There appears to be an association between potential opportunistic pathogens and microbial community structures. These microbial communities may be influenced by constituents within storage tank sediments. The results imply that compositions of microbial community and elements may influence and indicate microbial water quality and pipeline corrosion, and that these constituents may be important for optimal storage tank management

Antimicrobial activity of ceftaroline and other anti-infective agents against microbial pathogens recovered from the surgical intensive care patient population: a prevalence analysis.

Science.gov (United States)

Edmiston, Charles E; Krepel, Candace J; Leaper, David; Ledeboer, Nathan A; Mackey, Tami-Lea; Graham, Mary Beth; Lee, Cheong; Rossi, Peter J; Brown, Kellie R; Lewis, Brian D; Seabrook, Gary R

2014-12-01

Ceftaroline is a new parenteral cephalosporin agent with excellent activity against methicillin-sensitive (MSSA) and resistant strains of Staphylococcus aureus (MRSA). Critically ill surgical patients are susceptible to infection, often by multi-drug-resistant pathogens. The activity of ceftaroline against such pathogens has not been described. Three hundred thirty-five consecutive microbial isolates were collected from surgical wounds or abscesses, respiratory, urine, and blood cultures from patients in the surgical intensive care unit (SICU) of a major tertiary medical center. Using Clinical and Laboratory Standards Institute (CLSI) standard methodology and published breakpoints, all aerobic, facultative anaerobic isolates were tested against ceftaroline and selected comparative antimicrobial agents. All staphylococcal isolates were susceptible to ceftaroline at a breakpoint of ≤1.0 mcg/mL. In addition, ceftaroline exhibited excellent activity against all streptococcal clinical isolates and non-ESBL-producing strains of Enterobacteriaceae (93.5%) recovered from SICU patients. Ceftaroline was inactive against ESBL-producing Enterobacteriaceae, Pseudomonas aeruginosa, vancomycin-resistant enterococci, and selective gram-negative anaerobic bacteria. At present, ceftaroline is the only cephalosporin agent that is active against community and healthcare-associated MRSA. Further studies are needed to validate the benefit of this novel broad-spectrum anti-infective agent for the treatment of susceptible serious infections in the SICU patient population.

Pathogenicity of Fusarium avenaceum isolates to tulip leaves assessed on leaf disks

Directory of Open Access Journals (Sweden)

Agnieszka Piwoni

2013-12-01

Full Text Available The purpose of this study was to investigate the pathogenicity of 14 Fusarium avenaceum (Giberella avenacea isolates, obtained from tulip plantations located in Puławy region, to leaves of tulip cv. Apeldoorn. Mycelial plugs 3 mm in diameter from the margins of the colonies growing on PDA and SNA were placed on 20 mm disks cut from tulip leaves. The disks were placed abaxial surface up, in Petri dishes on top of filter paper soaked with 100 mg/l gibberellic acid to retard leaf senescence. There were 5 replications for each isolate. Leaves in each Petń dish were inoculated with one isolate. Plates were incubated at 20°C and lesion diameters were measured after 4 days. The pathogenicity of investigated isolates was compared by measuring lesion development on tulip leaves. All of isolates colonized leaves disks succesfull - causing after 4 days necrotic lesions and sporulating after 14 days what indicated that an infection had occurred. There were significant differences in lesions size among isolates. Isolates: 27, 1, 2, 48 and 3 caused largest lesions at mean size from 150 mm2 to 163 mm2 what indicates their high pathogenicity. Less pathogenic were isolates: 28, 42, 7 and 72 caused lesions at mean size from 46 mm2 to 97 mm~2. On average, mycelial plugs taken from PDA medium colonized leaf disks more efficient in comparison to them taken from SNA, that caused smaller lesions.

The role of hyperparasitism in microbial pathogen ecology and evolution.

Science.gov (United States)

Parratt, Steven R; Laine, Anna-Liisa

2016-08-01

Many micro-organisms employ a parasitic lifestyle and, through their antagonistic interactions with host populations, have major impacts on human, agricultural and natural ecosystems. Most pathogens are likely to host parasites of their own, that is, hyperparasites, but how nested chains of parasites impact on disease dynamics is grossly neglected in the ecological and evolutionary literature. In this minireview we argue that the diversity and dynamics of micro-hyperparasites are an important component of natural host-pathogen systems. We use the current literature from a handful of key systems to show that observed patterns of pathogen virulence and disease dynamics may well be influenced by hyperparasites. Exploring these factors will shed light on many aspects of microbial ecology and disease biology, including resistance-virulence evolution, apparent competition, epidemiology and ecosystem stability. Considering the importance of hyperparasites in natural populations will have applied consequences for the field of biological control and therapeutic science, where hyperparastism is employed as a control mechanism but not necessarily ecologically understood.

PATHOGENICITY OF FUSARIUM SPP. ISOLATED FROM WEEDS AND PLANT DEBRIS IN EASTERN CROATIA TO WHEAT AND MAIZE

Directory of Open Access Journals (Sweden)

Jelena Ilić

2012-12-01

Full Text Available Pathogenicity of thirty isolates representing 14 Fusarium species isolated from weeds and plant debris in eastern Croatia was investigated in the laboratory. Pathogenicity tests were performed on wheat and maize seedlings. The most pathogenic Fusarium spp. was F. graminearum isolated from Amaranthus retroflexus, Abutilon theophrasti and Chenopodium album. There was a noticeable inter- and intraspecies variability in pathogenicity towards wheat and maize. Isolates of F. solani from Sonchus arvensis and F. verticillioides from C. album were highly pathogenic to wheat seedlings and apathogenic to maize seedlings. Isolates of F. venenatum were very pathogenic to wheat and maize being the first report about pathogenicity of this species. This experiment proves that weeds and plant debris can serve as alternate hosts and source of inoculum of plant pathogens.

Molecular characterization of bacteria isolated from the Kingdom of ...

African Journals Online (AJOL)

ola

2012-11-06

Nov 6, 2012 ... Esherichia coli strains isolated from different habitats in relation to their antimicrobial activity against pathogenic fungi causing dermatological diseases. MATERIALS AND METHODS. Microbial strains, media and culture conditions. Bacterial isolates from soil samples were collected from different localities ...

Antimicrobial-Resistance Genetic Markers in Potentially Pathogenic Gram Positive Cocci Isolated from Brazilian Soft Cheese.

Science.gov (United States)

Resende, Juliana Alves; Fontes, Cláudia Oliveira; Ferreira-Machado, Alessandra Barbosa; Nascimento, Thiago César; Silva, Vânia Lúcia; Diniz, Cláudio Galuppo

2018-02-01

Although most Brazilian dairy products meet high technological standards, there are quality issues regarding milk production, which may reduce the final product quality. Several microbial species may contaminate milk during manufacture and handling. If antimicrobial usage remains uncontrolled in dairy cattle, the horizontal transfer of antimicrobial resistance genes in foodstuffs may be of particular concern for both food producers and dairy industry. This study focused on the evaluation of putative Gram positive cocci in Minas cheese and of antimicrobial and biocide resistance genes among the isolated bacteria. Representative samples of 7 different industrially trademarked Minas cheeses (n = 35) were processed for selective culture and isolation of Gram positive cocci. All isolated bacteria were identified by DNA sequencing of the 16S rRNA gene. Antimicrobial resistance genes were screened by PCR. Overall, 208 strains were isolated and identified as follows: Enterococcus faecalis (47.6%), Macrococcus caseolyticus (18.3%), Enterococcus faecium (11.5%), Enterococcus caseliflavus (7.7%), Staphylococcus haemolyticus (7.2%), Staphylococcus aureus (4.3%), Staphylococcus epidermidis (2.9%), and Enterococcus hirae (0.5%). The genetic markers mecA (78.0%) and smr (71.4%) were the most prevalent, but others were also detected, such as blaZ (65.2%), msrA (60.9%), msrB (46.6%), linA (54.7%), and aacA-aphD (47.6%). The occurrence of opportunist pathogenic bacteria harboring antimicrobial resistance markers in the cheese samples are of special concern, since these bacteria are not considered harmful contaminating agents according to the Brazilian sanitary regulations. However, they are potentially pathogenic bacteria and the cheese may be considered a reservoir for antimicrobial resistance genes available for horizontal transfer through the food chain, manufacturing personnel and consumers. © 2018 Institute of Food Technologists®.

A low pathogenic H5N2 influenza virus isolated in Taiwan acquired high pathogenicity by consecutive passages in chickens.

OpenAIRE

Soda, Kosuke; Cheng, Ming-Chu; Yoshida, Hiromi; Endo, Mayumi; Lee, Shu-Hwae; Okamatsu, Masatoshi; Sakoda, Yoshihiro; Wang, Ching-Ho; Kida, Hiroshi

2011-01-01

H5N2 viruses were isolated from cloacal swab samples of apparently healthy chickens in Taiwan in 2003 and 2008 during surveillance of avian influenza. Each of the viruses was eradicated by stamping out. The official diagnosis report indicated that the Intravenous Pathogenicity Indexes (IVPIs) of the isolates were 0.00 and 0.89, respectively, indicating that these were low pathogenic strains, although the hemagglutinin of the strain isolated in 2008 (Taiwan08) had multibasic amino acid residue...

Antibiotic-Resistant Pathogenic Escherichia Coli Isolated from Rooftop Rainwater-Harvesting Tanks in the Eastern Cape, South Africa

Directory of Open Access Journals (Sweden)

Mokaba Shirley Malema

2018-05-01

Full Text Available Although many developing countries use harvested rainwater (HRW for drinking and other household purposes, its quality is seldom monitored. Continuous assessment of the microbial quality of HRW would ensure the safety of users of such water. The current study investigated the prevalence of pathogenic Escherichia coli strains and their antimicrobial resistance patterns in HRW tanks in the Eastern Cape, South Africa. Rainwater samples were collected weekly between June and September 2016 from 11 tanks in various areas of the province. Enumeration of E. coli was performed using the Colilert®18/Quanti-Tray® 2000 method. E. coli isolates were obtained and screened for their virulence potentials using polymerase chain reaction (PCR, and subsequently tested for antibiotic resistance using the disc-diffusion method against 11 antibiotics. The pathotype most detected was the neonatal meningitis E. coli (NMEC (ibeA 28% while pathotype enteroaggregative E. coli (EAEC was not detected. The highest resistance of the E. coli isolates was observed against Cephalothin (76%. All tested pathotypes were susceptible to Gentamicin, and 52% demonstrated multiple-antibiotic resistance (MAR. The results of the current study are of public health concern since the use of untreated harvested rainwater for potable purposes may pose a risk of transmission of pathogenic and antimicrobial-resistant E. coli.

Antibiotic-Resistant Pathogenic Escherichia Coli Isolated from Rooftop Rainwater-Harvesting Tanks in the Eastern Cape, South Africa.

Science.gov (United States)

Malema, Mokaba Shirley; Abia, Akebe Luther King; Tandlich, Roman; Zuma, Bonga; Mwenge Kahinda, Jean-Marc; Ubomba-Jaswa, Eunice

2018-05-01

Although many developing countries use harvested rainwater (HRW) for drinking and other household purposes, its quality is seldom monitored. Continuous assessment of the microbial quality of HRW would ensure the safety of users of such water. The current study investigated the prevalence of pathogenic Escherichia coli strains and their antimicrobial resistance patterns in HRW tanks in the Eastern Cape, South Africa. Rainwater samples were collected weekly between June and September 2016 from 11 tanks in various areas of the province. Enumeration of E. coli was performed using the Colilert ® 18/Quanti-Tray ® 2000 method. E. coli isolates were obtained and screened for their virulence potentials using polymerase chain reaction (PCR), and subsequently tested for antibiotic resistance using the disc-diffusion method against 11 antibiotics. The pathotype most detected was the neonatal meningitis E. coli (NMEC) ( ibeA 28%) while pathotype enteroaggregative E. coli (EAEC) was not detected. The highest resistance of the E. coli isolates was observed against Cephalothin (76%). All tested pathotypes were susceptible to Gentamicin, and 52% demonstrated multiple-antibiotic resistance (MAR). The results of the current study are of public health concern since the use of untreated harvested rainwater for potable purposes may pose a risk of transmission of pathogenic and antimicrobial-resistant E. coli.

Characterization and isolation of an extracellular serine protease from the tomato pathogen Colletotrichum coccodes, and it's role in pathogenicity

Science.gov (United States)

Redman, Regina S.; Rodriguez, Rusty J.

2002-01-01

Extracellular enzymes play an important role in the pathogenicity and virulence of phytopathogenic fungi. Several isolates of Colletotrichum coccodes causal agent of anthracnose on tomato, were screened to determine the relationship between protease activity and virulence. A direct relationship was observed between extracellular protease activity and the induction of disease symptoms of fruit and mortality in plants. Isolate Cc155 exhibited the highest protease activity after five days of growth in protease induction medium and produced an extracellular serine protease (sp78) that was 78 kDa, auto-degradative, glucose repressible, and non-glycosylated. To determine the role of sp78 in pathogenicity, a UV-induced extracellular protease deficient mutant (np155) was generated from the wildtype isolate Cc155. Np155 maintained growth rates comparable to Cc155 and produced wildtype levels of extracellular cellulase but did not produce extracellular protease. Unlike Cc155, np155 caused no disease symptoms on tomato fruit and 0% mortality on tomato seedlings. These results suggest that extracellular protease activity is required for pathogenicity and virulence of C. coccodes and that the elimination of protease activity transforms a virulent pathogen to a non-pathogenic endophyte.

Hiding in Fresh Fruits and Vegetables: Opportunistic Pathogens May Cross Geographical Barriers

Directory of Open Access Journals (Sweden)

Zahra S. Al-Kharousi

2016-01-01

Full Text Available Different microbial groups of the microbiome of fresh produce can have diverse effects on human health. This study was aimed at identifying some microbial communities of fresh produce by analyzing 105 samples of imported fresh fruits and vegetables originated from different countries in the world including local samples (Oman for aerobic plate count and the counts of Enterobacteriaceae, Enterococcus, and Staphylococcus aureus. The isolated bacteria were identified by molecular (PCR and biochemical methods (VITEK 2. Enterobacteriaceae occurred in 60% of fruits and 91% of vegetables. Enterococcus was isolated from 20% of fruits and 42% of vegetables. E. coli and S. aureus were isolated from 22% and 7% of vegetables, respectively. Ninety-seven bacteria comprising 21 species were similarly identified by VITEK 2 and PCR to species level. E. coli, Klebsiella pneumoniae, Enterococcus casseliflavus, and Enterobacter cloacae were the most abundant species; many are known as opportunistic pathogens which may raise concern to improve the microbial quality of fresh produce. Phylogenetic trees showed no relationship between clustering of the isolates based on the 16S rRNA gene and the original countries of fresh produce. Intercountry passage of opportunistic pathogens in fresh produce cannot be ruled out, which requires better management.

77 FR 45350 - Notice of Availability of Microbial Risk Assessment Guideline: Pathogenic Microorganisms With...

Science.gov (United States)

2012-07-31

... ENVIRONMENTAL PROTECTION AGENCY Notice of Availability of Microbial Risk Assessment Guideline: Pathogenic Microorganisms With Focus on Food and Water AGENCY: Environmental Protection Agency (EPA). ACTION... risk assessment and also promote consistency in approaches and methods. The MRA Guideline can be...

Antibiotic resistance profile of Escherichia coli isolated from five ...

African Journals Online (AJOL)

Information on the resistance profiles of clinical and non clinical human bacteria isolates in the developing countries can serve as important means of understanding the human pathogens drug resistance interactions in the zone. Escherichia coli isolated from five geopolitical zones of Nigeria were screened for anti-microbial ...

Screening Microbial Contamination of Smoking Waterpipe (Narghile in Erbil city/ Iraq

Directory of Open Access Journals (Sweden)

Salah Tofik Jalal Balaky

2018-03-01

Full Text Available Tobacco smoking, which is a traditional habit is a major health risk worldwide. However waterpipe (Narghile smoking is an emerging smoking type, specifically among Erbil/ Iraq. In the recent years, smoking of Shisha (Narghile has spread amongst adolescents and young adults in Erbil city. The aims of this study are to examine the prevalence of shisha pipe smoking in Erbil city and to determine the microbial pathogen contaminants present in these Shisha pipes. In this study, we performed a qualitative and quantitative analysis of the microbial contamination of (90 Shisha hose samples in Erbil. Eighteen samples were selected from each cafe and swabs were cultured and identified. Results showed that most Narghile users 82.2 % were male and half of them (50% were in the age group of 20-30 years followed by the age group of 30-40 years. Data showed that 54% of the samples were contaminated, from them most microbial pathogens were G+ve bacteria. Staphylococcus albus and Staphylococcus aureus were among the most isolated pathogens, however E. coli was the most common G-ve bacteria in this study. On the other hand the number of fungi and yeasts identified in this study were 7 isolates, among them Monilia, Paecillomycet spp and Aspergillus niger were most common isolates. In conclusion, data produced from this study showed that Narghile users are exposed to many infectious microbial agents, because many users are unaware of the associated microbial contaminations and smoke narghile as a safe alternative to cigarette smoking. More research, should focus on strategies on how to avoid shisha smoking as the impact of its use is expected to affect the health and life of many people in our local community.

The need for high-quality whole-genome sequence databases in microbial forensics.

Science.gov (United States)

Sjödin, Andreas; Broman, Tina; Melefors, Öjar; Andersson, Gunnar; Rasmusson, Birgitta; Knutsson, Rickard; Forsman, Mats

2013-09-01

Microbial forensics is an important part of a strengthened capability to respond to biocrime and bioterrorism incidents to aid in the complex task of distinguishing between natural outbreaks and deliberate acts. The goal of a microbial forensic investigation is to identify and criminally prosecute those responsible for a biological attack, and it involves a detailed analysis of the weapon--that is, the pathogen. The recent development of next-generation sequencing (NGS) technologies has greatly increased the resolution that can be achieved in microbial forensic analyses. It is now possible to identify, quickly and in an unbiased manner, previously undetectable genome differences between closely related isolates. This development is particularly relevant for the most deadly bacterial diseases that are caused by bacterial lineages with extremely low levels of genetic diversity. Whole-genome analysis of pathogens is envisaged to be increasingly essential for this purpose. In a microbial forensic context, whole-genome sequence analysis is the ultimate method for strain comparisons as it is informative during identification, characterization, and attribution--all 3 major stages of the investigation--and at all levels of microbial strain identity resolution (ie, it resolves the full spectrum from family to isolate). Given these capabilities, one bottleneck in microbial forensics investigations is the availability of high-quality reference databases of bacterial whole-genome sequences. To be of high quality, databases need to be curated and accurate in terms of sequences, metadata, and genetic diversity coverage. The development of whole-genome sequence databases will be instrumental in successfully tracing pathogens in the future.

DMPD: Toll-like receptors and the host defense against microbial pathogens: bringingspecificity to the innate-immune system. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 15075354 Toll-like receptors and the host defense against microbial pathogens: brin...oc Biol. 2004 May;75(5):749-55. Epub 2004 Jan 14. (.png) (.svg) (.html) (.csml) Show Toll-like receptors and the host defense again...immune system. PubmedID 15075354 Title Toll-like receptors and the host defense against microbial pathogens:

Morphological and Pathogenic Variability among Macrophomina phaseolina Isolates Associated with Mungbean (Vigna radiata L. Wilczek from Pakistan

Directory of Open Access Journals (Sweden)

Umer Iqbal

2014-01-01

Full Text Available Macrophomina phaseolina is a serious pathogen of many crops. In the present studies, 65 isolates of Macrophomina phaseolina from different agroecological regions of Punjab and Khyber Pakhtunkhwa provinces of Pakistan were analyzed for morphological and pathogenic variability. Regardless of their geographic origins, significant differences were detected among 65 isolates in their radial growth, sclerotial size, and weight as well as in pathogenicity. Sixteen isolates were rated as fast growing, 11 as slow growing, and the rest of the isolates as medium growing. Nine isolates were classified as large sized, 26 as small sized, and the remaining 30 isolates as medium sized. Thirty five isolates were ranked as heavy weight, 12 as low weight, and the rest of isolates were grouped as medium weight. Ten fungal isolates appeared to be least virulent, whereas eight isolates of diverse origin proved to be highly virulent against mungbean cultivars. The remaining isolates were regarded as moderately virulent. No relationship was found among the morphological characters and pathogenicity of the isolates. These morphological and pathogenic variations in various isolates of M. phaseolina may be considered important in disease management systems and will be useful in breeding programmes of mungbean cultivars resistant to charcoal rot.

Co-occurrence of pathogenic and non-pathogenic Fusarium decemcellulare and Lasiodiplodia theobromae isolates in cushion galls disease of cacao (Theobroma cacao L.

Directory of Open Access Journals (Sweden)

Castillo Daynet Sosa del

2016-04-01

Full Text Available Flowery cushion gall of cacao is a disease complex with six types. Fusarium decemcellulare have been isolated from both flowery and green point galls and recognized as the etiological agent of the disease. In the present work we: i identified by ITS-rDNA sequencing and/or taxonomy the cultivable fungal species or Operative Taxonomic Units (OTUs associated with the five symptoms of cushion galls in cacao from Venezuela, and ii determined the gall inducing capacity on cacao peeled seeds after 45 days of inoculation with suspensions of mycelia/ spores from distinct isolate types. The whole isolate collection rendered an abundance of 113 isolates with a richness of 39 OTUs (27 and eight identified at the species or genera levels, respectively, and in unidentified fungi. The dominant recovered species (≈36% were F. decemcellulare and Lasiodiplodia theobromae. Some isolates of F. decemcellulare, L. theobromae, F. equiseti, Fusarium spp., F. solani, F. incarnatum, Rhizocthonia solani and Penicillium sp. were pathogenic. Some other isolates of the first six mentioned taxa behave as non-pathogenic. Furthermore, pathogenic and non-pathogenic isolates can also co-occur within a single plant and gall type. Moreover, 2-5 species within a single gall symptom in a single tree were identified (not necessarily at the same point in the tree, indicating a broad diversity of co-occurring taxa.

Fusarium proliferatum isolated from garlic in Spain: identification, toxigenic potential and pathogenicity on related Allium species

Directory of Open Access Journals (Sweden)

Daniel PALMERO

2012-05-01

Full Text Available Fusarium proliferatum has been reported on garlic in the Northwest USA, Spain and Serbia, causing water-soaked tan-colored lesions on cloves. In this work, Fusarium proliferatum was isolated from 300 symptomatic garlic bulbs. Morphological identification of Fusarium was confirmed using species-specific PCR assays and EF-1α sequencing. Confirmation of pathogenicity was conducted with eighteen isolates. Six randomly selected F. proliferatum isolates from garlic were tested for specific pathogenicity and screened for fusaric acid production. Additionally, pathogenicity of each F. proliferatum isolate was tested on healthy seedlings of onion (Allium cepa, leek (A. porrum, scallions (A. fistulosum, chives (A. schoenoprasum and garlic (A. sativum. A disease severity index (DSI was calculated as the mean severity on three plants of each species with four test replicates. Symptoms on onion and garlic plants were observed three weeks after inoculation. All isolates tested produced symptoms on all varieties inoculated. Inoculation of F. proliferatum isolates from diseased garlic onto other Allium species provided new information on host range and pathogenicity. The results demonstrated differences in susceptibility with respect to host species and cultivar. The F. proliferatum isolates tested all produced fusaric acid (FA; correlations between FA production and isolate pathogenicity are discussed. Additionally, all isolates showed the presence of the FUM1 gene suggesting the ability of Spanish isolates to produce fumonisins.

Phenotypic and molecular typing of Vibrio harveyi isolates and their pathogenicity to tiger shrimp larvae.

Science.gov (United States)

Alavandi, S V; Manoranjita, V; Vijayan, K K; Kalaimani, N; Santiago, T C

2006-11-01

The objective of the present study was to identify the biotype(s) and molecular type(s) of Vibrio harveyi associated with pathogenicity in tiger shrimp (Penaeus monodon) larvae. Five luminescent and four nonluminescent V. harveyi isolates were subjected to phenotyping and random amplified polymorphic DNA (RAPD) fingerprinting, and pathogenicity testing to P. monodon mysis. Four isolates induced 34-41% mortality of P. monodon mysis when challenged at the rate of 10(6) CFU ml(-1) within 60 h. Sucrose-fermenting biotypes of V. harveyi appeared to be associated with pathogenicity to larval shrimp. Higher temperature and salinity appeared to play a role on the onset of vibriosis and mortality in the challenged larval shrimp. Pathogenic isolates of V. harveyi could be demarcated as revealed by their clustering in the dendrogram constructed based on the RAPD fingerprints. Nonluminescent V. harveyi also appear to be important aetiological agents of vibriosis of shrimp larvae. Sucrose-fermenting biotypes are likely to be pathogenic. High temperature may trigger onset of vibriosis. Biotyping of V. harveyi isolates and looking for traits, such as ability to ferment sucrose may be helpful in identifying the pathogenic forms, and such approach requires to be investigated further with larger number of isolates.

Characteristics of pathogenic Vibrio sp. isolated from the rockfish, Sebastes schlegeli

International Nuclear Information System (INIS)

Kim, Jong Hwa

1995-02-01

At the summer time, an infectious bacterial disease occurs and damages the net cage farms of rockfish (Sebastes schlegeli) at the western coast of Korea. The symptoms of this disease include darkness of body color, ulceration of skin, anemia of gill-filaments, and congestion of operculum. In order to know the attributes of pathogenicity of this disease, the study is performed with isolated bacteria from the rockfish sampled at the fish farm, located at Taean-gun Chungcheongnam-do, from June to September in 1994. The pathogenic bacteria cna be isolated from dermal lesion, kidney, liver, and spleen of the sick fish, and classified as Vibrio sp. based on the morphological, biological, and biochemical examinations. These isolates are proliferated in BTB teepol, TCBS, TSA, XA, BHIA, media, not in SS and MacConkey media, and the optimal growth conditions for NaCl concentration, pH, and temperature are 3%, 7∼8, and 25∼30 .deg. C, respectively. They turn out to be sensitive to three chemicals such as SXT (sulfamethoxazol + trimethoprim), nalidixic acid, and tetracycline, but resistant to ampicillin and penicillin G. Finally, the virulence of infectious bacteria is appeared at both 20 .deg. C and 27 .deg. C when isolated pathogenic strains are injected into the muscle of healthy rockfish

Isolation of pathogenic Escherichia coli from buffalo meat sold in Parbhani city, Maharashtra, India

OpenAIRE

M. S. Vaidya; N. M. Markandeya; R. N. Waghamare; C. S. Shekh; V. V. Deshmukh

2013-01-01

Aim: Isolation, characterization, in-vitro pathogenicity and antibiogram study of E.coli from buffalo meat sold in Parbhani city. Materials and Methods: Meat samples were collected from buffalo immediately after slaughter. Isolation, identification and enumeration of E. coli were done by following standard methods and protocols. Hemolysin test and Congo red binding assay were used to study in-vitro pathogenicity of E. coli isolates. Disc diffusion method was used to study antibiogram of patho...

Beneficial and Harmful Interactions of Antibiotics with Microbial Pathogens and the Host Innate Immune System

Directory of Open Access Journals (Sweden)

Ronald Anderson

2010-05-01

Full Text Available In general antibiotics interact cooperatively with host defences, weakening and decreasing the virulence of microbial pathogens, thereby increasing vulnerability to phagocytosis and eradication by the intrinsic antimicrobial systems of the host. Antibiotics, however, also interact with host defences by several other mechanisms, some harmful, others beneficial. Harmful activities include exacerbation of potentially damaging inflammatory responses, a property of cell-wall targeted agents, which promotes the release of pro-inflammatory microbial cytotoxins and cell-wall components. On the other hand, inhibitors of bacterial protein synthesis, especially macrolides, possess beneficial anti-inflammatory/cytoprotective activities, which result from interference with the production of microbial virulence factors/cytotoxins. In addition to these pathogen-directed, anti-inflammatory activities, some classes of antimicrobial agent possess secondary anti-inflammatory properties, unrelated to their conventional antimicrobial activities, which target cells of the innate immune system, particularly neutrophils. This is a relatively uncommon, potentially beneficial property of antibiotics, which has been described for macrolides, imidazole anti-mycotics, fluoroquinolones, and tetracyclines. Although of largely unproven significance in the clinical setting, increasing awareness of the pro-inflammatory and anti-inflammatory properties of antibiotics may contribute to a more discerning and effective use of these agents.

The response of CD1d-restricted invariant NKT cells to microbial pathogens and their products

Directory of Open Access Journals (Sweden)

Luc eVan Kaer

2015-05-01

Full Text Available Invariant natural killer T (iNKT cells become activated during a wide variety of infections. This includes organisms lacking cognate CD1d-binding glycolipid antigens recognized by the semi-invariant T cell receptor of iNKT cells. Additional studies have shown that iNKT cells also become activated in vivo in response to microbial products such as bacterial lipopolysaccharide, a potent inducer of cytokine production in antigen-presenting cells (APCs. Other studies have shown that iNKT cells are highly responsive to stimulation by cytokines such as interleukin-12. These findings have led to the concept that microbial pathogens can activate iNKT cells either directly via glycolipids, or indirectly by inducing cytokine production in APCs. iNKT cells activated in this manner produce multiple cytokines that can influence the outcome of infection, usually in favor of the host, although potent iNKT cell activation may contribute to an uncontrolled cytokine storm and sepsis. One aspect of the response of iNKT cells to microbial pathogens is that it is short-lived and followed by an extended time period of unresponsiveness to reactivation. This refractory period may represent a means to avoid chronic activation and cytokine production by iNKT cells, thus protecting the host against some of the negative effects of iNKT cell activation, but potentially putting the host at risk for secondary infections. These effects of microbial pathogens and their products on iNKT cells are not only important for understanding the role of these cells in immune responses against infections but also for the development of iNKT cell-based therapies.

Microbial secondary metabolites are an alternative approaches against insect vector to prevent zoonotic diseases

Directory of Open Access Journals (Sweden)

Dharumadurai Dhanasekaran

2014-08-01

Full Text Available Approximately 1500 naturally occurring microorganisms have been identified as potentially insecticidal agents. Metabolites from 942 microbial isolates were screened for insecticidal and properties. The isolates included 302 streptomycetes, 502 novel actinobacteria including representatives of 18 genera, 28 unidentified aerobic actinobacteria, 70 fungi and 40 bacteria other than actinobacteria showed the insecticidal activity. Most spore-forming bacteria pathogenic to insects belong to the family Bacillaceae. Only four Bacillus species namely Bacillus thuringiensis, Bacillus popilliae, Bacillus lentimorbus, Bacillus sphaericus have been closely examined as insect control agents. Fungi are applied directly in the form of spores, mycelia or blastospores or by their metabolites. Many viruses that belong to the family Baculoviridae are pathogenic in insects. The microbial insecticides are generally pest-specific, readily biodegradable and usually lack toxicity to higher animals. This review paper communicates the insect problem in the transmission of diseases in human, animals, plants and problem of chemical insecticides control of insects using microbial metabolites from actinobacteria, bacteria, fungi and viruses.

Identification and characterization of novel natural pathogen of Drosophila melanogaster isolated from wild captured Drosophila spp.

Science.gov (United States)

Singh, Karan; Zulkifli, Mohammad; Prasad, N G

2016-12-01

Drosophila melanogaster is an emerging model system for the study of evolutionary ecology of immunity. However, a large number of studies have used non natural pathogens as very few natural pathogens have been isolated and identified. Our aim was to isolate and characterize natural pathogen/s of D. melanogaster. A bacterial pathogen was isolated from wild caught Drosophila spp., identified as a new strain of Staphylococcus succinus subsp. succinus and named PK-1. This strain induced substantial mortality (36-62%) in adults of several laboratory populations of D. melanogaster. PK-1 grew rapidly within the body of the flies post infection and both males and females had roughly same number of colony forming units. Mortality was affected by mode of infection and dosage of the pathogen. However mating status of the host had no effect on mortality post infection. Given that there are very few known natural bacterial pathogens of D. melanogaster and that PK-1 can establish a sustained infection across various outbred and inbred populations of D. melanogaster this new isolate is a potential resource for future studies on immunity. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

The rhizosphere microbial community in a multiple parallel mineralization system suppresses the pathogenic fungus Fusarium oxysporum

Science.gov (United States)

Fujiwara, Kazuki; Iida, Yuichiro; Iwai, Takashi; Aoyama, Chihiro; Inukai, Ryuya; Ando, Akinori; Ogawa, Jun; Ohnishi, Jun; Terami, Fumihiro; Takano, Masao; Shinohara, Makoto

2013-01-01

The rhizosphere microbial community in a hydroponics system with multiple parallel mineralization (MPM) can potentially suppress root-borne diseases. This study focused on revealing the biological nature of the suppression against Fusarium wilt disease, which is caused by the fungus Fusarium oxysporum, and describing the factors that may influence the fungal pathogen in the MPM system. We demonstrated that the rhizosphere microbiota that developed in the MPM system could suppress Fusarium wilt disease under in vitro and greenhouse conditions. The microbiological characteristics of the MPM system were able to control the population dynamics of F. oxysporum, but did not eradicate the fungal pathogen. The roles of the microbiological agents underlying the disease suppression and the magnitude of the disease suppression in the MPM system appear to depend on the microbial density. F. oxysporum that survived in the MPM system formed chlamydospores when exposed to the rhizosphere microbiota. These results suggest that the microbiota suppresses proliferation of F. oxysporum by controlling the pathogen's morphogenesis and by developing an ecosystem that permits coexistence with F. oxysporum. PMID:24311557

ISOLATION AND PATHOGENICITY OF A POSSIBLE Pythium aphanidermatum IN Jatropha Curcas L. NON TOXIC

Directory of Open Access Journals (Sweden)

Ofelia Andrea Valdes Rodriguez

2011-03-01

A chromista, possible Pythium aphanidermatum, was isolated from severely damage seeds and seedlings recently started from Jatropha curcas L. non toxic seeds sown in the tropical area of Veracruz, Mexico. In order to study pathogenic Pythium aphanidermatum effects over pre-emergent and post-emergent stages, seeds and young seedlings were inoculated with the isolated pathogen, and the chromista showed possible pathogenic activity against pre-emergency and recently started post-emergency; however, statistically significant damaged was not found in older seedlings.   Â

Efficacy of medicinal essential oils against pathogenic Malassezia sp. isolates.

Science.gov (United States)

Khosravi, A R; Shokri, H; Fahimirad, S

2016-03-01

The purposes of this study were to evaluate the distribution pattern and population size of Malassezia species in dogs with atopic dermatitis (AD) and the inhibitory efficacy of Zataria multiflora, Thymus kotschyanus, Mentha spicata, Artemisia sieberi, Rosmarinus officinalis and Heracleum persicum essential oils against pathogenic Malassezia isolates. The samples were collected from 5 different anatomical sites of 33 atopic dogs and cultured onto modified Dixon agar (MDA) and Sabouraud dextrose agar (SDA) media. The essential oil extraction was performed by steam distillation using Clevenger system. Anti-Malassezia efficacy of medicinal essential oils and standard drugs was evaluated using broth microdilution method. A total of 103 yeast colonies were isolated from dogs with AD. Eight different Malassezia species were identified as follows: Malassezia pachydermatis (81.4%), M. globosa (7.8%), M. restricta (3.9%), M. sloofiae (2.9%), M. furfur (1%), M. nana (1%), M. obtusa (1%) and M. sympodialis (1%). The most and least infected sites were: anal (21.2%) and ear (10.6%) respectively. M. pachydermatis was the most frequent Malassezia species isolated from both skin and mucosa of dogs with AD. Antifungal susceptibility test revealed the inhibitory efficacy of essential oils on pathogenic Malassezia isolates with minimum inhibitory concentration (MIC(90)) values ranging from 30 to 850 μg/mL. Among the tested oils, Z. multiflora and T. kotschyanus exhibited the highest inhibitory effects (Pessential oils of Z. multiflora and T. kotschyanus showed strong antifungal activity against pathogenic Malassezia species tested. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Zoonotic pathogens isolated from wild animals and environmental samples at two California wildlife hospitals.

Science.gov (United States)

Siembieda, Jennifer L; Miller, Woutrina A; Byrne, Barbara A; Ziccardi, Michael H; Anderson, Nancy; Chouicha, Nadira; Sandrock, Christian E; Johnson, Christine K

2011-03-15

To determine types and estimate prevalence of potentially zoonotic enteric pathogens shed by wild animals admitted to either of 2 wildlife hospitals and to characterize distribution of these pathogens and of aerobic bacteria in a hospital environment. Cross-sectional study. Fecal samples from 338 animals in 2 wildlife hospitals and environmental samples from 1 wildlife hospital. Fecal samples were collected within 24 hours of hospital admission. Environmental samples were collected from air and surfaces. Samples were tested for zoonotic pathogens via culture techniques and biochemical analyses. Prevalence of pathogen shedding was compared among species groups, ages, sexes, and seasons. Bacterial counts were determined for environmental samples. Campylobacter spp, Vibrio spp, Salmonella spp, Giardia spp, and Cryptosporidium spp (alone or in combination) were detected in 105 of 338 (31%) fecal samples. Campylobacter spp were isolated only from birds. Juvenile passerines were more likely to shed Campylobacter spp than were adults; prevalence increased among juvenile passerines during summer. Non-O1 serotypes of Vibrio cholerae were isolated from birds; during an oil-spill response, 9 of 10 seabirds screened were shedding this pathogen, which was also detected in environmental samples. Salmonella spp and Giardia spp were isolated from birds and mammals; Cryptosporidium spp were isolated from mammals only. Floors of animal rooms had higher bacterial counts than did floors with only human traffic. Potentially zoonotic enteric pathogens were identified in samples from several species admitted to wildlife hospitals, indicating potential for transmission if prevention is not practiced.

Survival after pathogen exposure in group-living insects: don't forget the stress of social isolation!

Science.gov (United States)

Kohlmeier, P; Holländer, K; Meunier, J

2016-09-01

A major cost of group-living is its inherent risk of pathogen infection. To limit this risk, many group-living animals have developed the capability to prophylactically boost their immune system in the presence of group members and/or to mount collective defences against pathogens. These two phenomena, called density-dependent prophylaxis and social immunity, respectively, are often used to explain why, in group-living species, individuals survive better in groups than in isolation. However, this survival difference may also reflect an alternative and often overlooked process: a cost of social isolation on individuals' capability to fight against infections. Here, we disentangled the effects of density-dependent prophylaxis, social immunity and stress of social isolation on the survival after pathogen exposure in group-living adults of the European earwig Forficula auricularia. By manipulating the presence of group members both before and after pathogen exposure, we demonstrated that the cost of being isolated after infection, but not the benefits of social immunity or density-dependent prophylaxis, explained the survival of females. Specifically, females kept constantly in groups or constantly isolated had higher survival rates than females that were first in groups and then isolated after infection. Our results also showed that this cost of social isolation was absent in males and that social isolation did not reduce the survival of noninfected individuals. Overall, this study gives a new perspective on the role of pathogens in social evolution, as it suggests that an apparently nonadaptive, personal immune process may promote the maintenance of group-living under pathogenic environments. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Anti-Microbial Resistance Profiles Of E. Coli Isolated From Free Range Chickens In Urban And Rural Environments Of Imo State, Nigeria

Directory of Open Access Journals (Sweden)

Okoli IC

2006-07-01

Full Text Available Information on the resistance profiles of normal intestinal flora of extensively reared chickens that hardly receive antibiotics in the developing countries can serve as important means of understanding the human/animal pathogens drug resistance interactions in the zone. Three hundred and fifty E. coli isolates, comprising 133 from urban and 217 from rural sites in Imo state, Nigeria, were screened for anti-microbial resistance profile against 10 antibiotics using the disc diffusion method. Overall percentage anti-microbial resistance of the isolates against cotrimoxazole, ampicillin, nalidixic acid, chloramphenicol and nitrofurantoin (72–92% were very high. The organisms were highly sensitive to other antibiotics, especially gentamicin and ciprofloxacin. The 59.5% overall mean percentage resistance recorded at the urban area was significantly higher than the 46.8% recorded at the rural area (p<0.05. With the exception of the figures for cotrimoxazole and ampicillin, resistance values obtained against the other antibiotics at the urban sites were statistically higher than those obtained at the rural sites (p<0.05. Zero resistance was recorded against the fluoroquinolones, norfloxacin and ciprofloxacin at all the rural sites except at Enyiogwugwu where a 28.6% resistance was obtained against norfloxacin. Since free-range chickens rarely receive antibiotic medication, it is concluded that the highly resistant E. coli organisms isolated from them may be reflecting consequences of human drug use in the study areas.

Antimicrobial profiles of periodontal pathogens isolated from periodontitis patients in the Netherlands and Spain

NARCIS (Netherlands)

van Winkelhoff, AJ; Herrera, D; Oteo, A; Sanz, M

Background and Aim: Antimicrobial resistance of periodontal pathogens towards currently used antibiotics in periodontics has been investigated in a previous study. Microbial resistance in the periodontal microflora was more frequently observed in Spanish patients in comparison with Dutch patients.

Isolation of Biosurfactant–Producing Bacteria with Antimicrobial Activity against Bacterial Pathogens

Directory of Open Access Journals (Sweden)

Siripun Sarin

2011-01-01

Full Text Available The aims of this research were to study biosurfactant producing bacteria isolated from soil and to determine their property and efficiency as biosurfactants in order to inhibit bacterial pathogens. The result showed that there were 8 bacterial isolates out of 136 isolates of the total biosurfactant producing bacteria screened that exhibited the diameter of clear zone more than 1.5 cm. in the oil spreading test. The highest potential of emulsifying activity (%EA24 of 54.4 and the maximum additive concentration, (%MAC of 24.2 was obtained from the fermentation broth of the G7 isolate which the G7 isolate was later identified as Pseudomonas fluorescens. Escherichia coli, Staphylococcus aureus and Psuedomonas aeruginosa were the tested bacterial pathogens that were most sensitive to the acid precipitated biosurfactant obtained from P. fluorescens G7 with the lowest minimum inhibitory concentration (MIC of 41.6 mg/ml and minimum bactericidal concentration (MBC of 41.6 mg/ml compared with the acid precipitated bisurfactants of the other isolates used in the antimicrobial activity test. The type of the separated crude biosurfactant produced by P. fluorescens G7 analyzed later by using the rhamose test, TLC and FT-IR techniques was rhamnolipid.

Cytotoxic and pathogenic properties of Klebsiella oxytoca isolated from laboratory animals.

Directory of Open Access Journals (Sweden)

Alison Darby

Full Text Available Klebsiella oxytoca is an opportunistic pathogen implicated in various clinical diseases in animals and humans. Studies suggest that in humans K. oxytoca exerts its pathogenicity in part through a cytotoxin. However, cytotoxin production in animal isolates of K. oxytoca and its pathogenic properties have not been characterized. Furthermore, neither the identity of the toxin nor a complete repertoire of genes involved in K. oxytoca pathogenesis have been fully elucidated. Here, we showed that several animal isolates of K. oxytoca, including the clinical isolates, produced secreted products in bacterial culture supernatant that display cytotoxicity on HEp-2 and HeLa cells, indicating the ability to produce cytotoxin. Cytotoxin production appears to be regulated by the environment, and soy based product was found to have a strong toxin induction property. The toxin was identified, by liquid chromatography-mass spectrometry and NMR spectroscopy, as low molecular weight heat labile benzodiazepine, tilivalline, previously shown to cause cytotoxicity in several cell lines, including mouse L1210 leukemic cells. Genome sequencing and analyses of a cytotoxin positive K. oxytoca strain isolated from an abscess of a mouse, identified genes previously shown to promote pathogenesis in other enteric bacterial pathogens including ecotin, several genes encoding for type IV and type VI secretion systems, and proteins that show sequence similarity to known bacterial toxins including cholera toxin. To our knowledge, these results demonstrate for the first time, that animal isolates of K. oxytoca, produces a cytotoxin, and that cytotoxin production is under strict environmental regulation. We also confirmed tilivalline as the cytotoxin present in animal K. oxytoca strains. These findings, along with the discovery of a repertoire of genes with virulence potential, provide important insights into the pathogenesis of K. oxytoca. As a novel diagnostic tool, tilivalline

Antibacterial Activities of Endophytic Bacteria Isolated from Taxus brevifolia Against Foodborne Pathogenic Bacteria.

Science.gov (United States)

Islam, Nurul; Choi, Jaehyuk; Baek, Kwang-Hyun

2018-05-01

Endophytes are a potential source of novel bioactive compounds with medicinal properties. In this study, 41 endophytic bacteria (EB) were isolated from tissues of a medicinally important plant Taxus brevifolia (Pacific yew). The objective was to screen all the EB isolates for their antibacterial effects against five foodborne pathogenic bacteria: Bacillus cereus ATCC10876, Staphylococcus aureus ATCC12600, Listeria monocytogenes ATCC19115, Escherichia coli ATCC43890, and Salmonella Typhimurium ATCC19585. Among the EB isolates, T. brevifolia seed (TbS)-8, T. brevifolia fleshy part of fruit (TbFl)-10, T. brevifolia leaf (TbL)-22, TbS-29, and TbL-34 exerted significant antibacterial activity against the tested foodborne pathogens. Especially TbFl-10 showed the highest antibacterial activity against all the tested bacteria and was identified as Paenibacillus kribbensis (Pk). Furthermore, an ethyl acetate extract of Pk-TbFl-10 possessed antibacterial activities against the tested five foodborne pathogenic bacteria, with zones of inhibition from 15.71 ± 2.85 to 13.01 ± 2.12 mm. Scanning electron microscopy analysis revealed ruptured, lysed, shrunk, and swollen cells of all the tested foodborne pathogens treated with the ethyl acetate extract of Pk-TbFl-10, suggesting that a metabolite(s) of Pk-TbFl-10 penetrates the cell membrane and causes cell lysis leading to cell death. Our results indicate that Pk-TbFl-10 isolated from T. brevifolia can serve as a novel source of natural antibacterial agents against foodborne pathogenic bacteria, with potential applications in the pharmaceutical industry.

Occurrence and antibacterial susceptibility pattern of bacterial pathogens isolated from diarrheal patients in Pakistan

Directory of Open Access Journals (Sweden)

Muhammad H. Rasool

2016-03-01

Full Text Available Objective: To determine the occurrence of bacterial pathogens responsible for diarrhea and to engender information regarding the effectiveness of commonly used antibiotic against diarrhea. Methods: This cross-sectional study was conducted between April and July 2014. Samples were collected from the Divisional Headquarter and Allied Hospital, Faisalabad, Pakistan. The differential and selective media were used to isolate bacterial pathogens, which were identified through cultural characteristics, microscopy, and biochemical tests. Disc diffusion assay was carried out using Muller Hinton agar medium, and minimum inhibitory concentration was determined using broth dilution method against isolated pathogens. Results: One hundred and forty-one (100% samples were positive for some bacteria. Frequency of occurrence was Bacillus cereus (B. cereus (66%, Escherichia coli (E. coli (48.5%, Salmonella typhi (S. Typhi (27.7%, Pseudomonas aeruginosa (P. aeruginosa (8.5%, and Staphylococcus aureus (S. aureus (4.3%. Single pathogen was detected in 20 (14.2% samples whereas combinations were found in 121 (85.8% samples. Bacillus cereus and E. coli were the most frequently detected pathogens followed by the S. Typhi, P. aeruginosa, and Staph. aureus. The percentage occurrence of isolated pathogens was 31% in B. cereus, 31% in E. coli, 18% in S. Typhi, 5% in P. aeruginosa, and 3% in Staph. aureus. Conclusion: Pseudomonas aeruginosa showed resistance against Amoxicillin and Cefotaxime, whereas S. aureus was found resistant against Cefotaxime. Statistical analysis using one way Analysis of Variance revealed that Ofloxacin and Gentamicin had significant (p<0.05 differences against all isolates as compared with other antibiotics used in this study.

TAXONOMY OF FUSARIUM SPECIES ISOLATED FROM CULTIVATED PLANTS, WEEDS AND THEIR PATHOGENICITY FOR WHEAT

Directory of Open Access Journals (Sweden)

Jasenka Ćosić

2002-06-01

Full Text Available Fusarium species are wide-spread and known to be pathogenic agents to cultivated plants in various agroclimatic areas. During a four year investigation 10 Fusarium species and Microdochium nivale were isolated from wheat, barley, maize and soybean as well as from 10 weeds collected from 10 locations in Slavonia and Baranya. Fusarium graminearum was dominant on wheat and barley, F. moniliforme on maize and F. oxysporum on soybean. Regarding weeds, the presence of the following Fusarium species was established: F. graminearum on Amaranthus hybridus, Capsella bursa-pastoris, Lamium purpureum, Sorghum halepense and Urtica dioica, F. moniliforme on Abutilon theophrasti, F. subglutinans on Polygonum aviculare, F. avenaceum on Capsella bursa-pastoris, Rumex crispus and Matricaria sp., F. culmorum on Abutilon theophrasti, F. sporotrichioides on Polygonum aviculare, F. proliferatum and F. poae on Artemisia vulgaris. Pathogenicity test to wheat seedlings was done in our laboratory on winter wheat cultivars Slavonija and Demetra (totally 146 isolates. The most pathogenic species to wheat seedilings were F. graminearum, F. culmorum and F. sporotrichioides and the least pathogenic F. moniliforme, F. solani, F. oxysporum and F. poae. Pathogenicity test for wheat ears was done on genotypes Osk.8c9/3-94 and Osk.6.11/2 (totally 25 isolates. The results obtained by our investigation showed that there were no significant differences in pathogenicity of Fusarium species isolated from both cultivated plants and weeds. Weeds represent a constant source of inoculum of F. species for cultivated plants and they serve as epidemiologic bridges among vegetations.

Occurrence and antibacterial susceptibility pattern of bacterial pathogens isolated from diarrheal patients in Pakistan.

Science.gov (United States)

Rasool, Muhammad H; Siddique, Abu B; Saqalein, Muhammad; Asghar, Muhammad J; Zahoor, Muhammad A; Aslam, Bilal; Shafiq, Humerah B; Nisar, Muhammad A

2016-03-01

To determine the occurrence of bacterial pathogens responsible for diarrhea and to engender information regarding the effectiveness of commonly used antibiotic against diarrhea. This cross-sectional study was conducted between April and July 2014. Samples were collected from the Divisional Headquarter and Allied Hospital, Faisalabad, Pakistan. The differential and selective media were used to isolate bacterial pathogens, which were identified through cultural characteristics, microscopy, and biochemical tests. Disc diffusion assay was carried out using Muller Hinton agar medium, and minimum inhibitory concentration was determined using broth dilution method against isolated pathogens. One hundred and forty-one (100%) samples were positive for some bacteria. Frequency of occurrence was Bacillus cereus (B. cereus) (66%), Escherichia coli (E.coli) (48.5%), Salmonella typhi (S. Typhi) (27.7%), Pseudomonas aeruginosa (P. aeruginosa) (8.5%), and Staphylococcus aureus (S. aureus) (4.3%). Single pathogen was detected in 20 (14.2%) samples whereas combinations were found in 121 (85.8%) samples. Bacillus cereus and E.coli were the most frequently detected pathogens followed by the S. Typhi, P. aeruginosa, and Staph. aureus. The percentage occurrence of isolated pathogens was 31% in B. cereus, 31% in E. coli, 18% in S. Typhi, 5% in P. aeruginosa, and 3% in Staph. aureus. Pseudomonas aeruginosa showed resistance against Amoxicillin and Cefotaxime, whereas S. aureus was found resistant against Cefotaxime. Statistical analysis using one way Analysis of Variance revealed that Ofloxacin and Gentamicin had significant (p less than 0.05) differences against all isolates as compared with other antibiotics used in this study.

Analysis of pathogenic factors of Proteus mirabilis isolated from urinary tract infection

OpenAIRE

室谷,勝久

1991-01-01

Proteus mirabilis has several pathogenic factors such as adherent ability to urinary tract epitherial cells, urease, motility and resistance to urine. The pathogenic activities of clinically isolated P. mirabilis were analyzed. Higher pathogenic strains (No. 25 and No. 30) which had morphologically different pili but had a higher density of pili showed strong adherent activity to bladder epithelial cells of mouse and rat. These strains also showed a clear chemotaxis to urinary tract tissue ex...

Genotypes and pathogenicity of cellulitis isolates reveal traits that modulate APEC virulence.

Directory of Open Access Journals (Sweden)

Nicolle Lima Barbieri

Full Text Available We characterized 144 Escherichia coli isolates from severe cellulitis lesions in broiler chickens from South Brazil. Analysis of susceptibility to 15 antimicrobials revealed frequencies of resistance of less than 30% for most antimicrobials except tetracycline (70% and sulphonamides (60%. The genotyping of 34 virulence-associated genes revealed that all the isolates harbored virulence factors related to adhesion, iron acquisition and serum resistance, which are characteristic of the avian pathogenic E. coli (APEC pathotype. ColV plasmid-associated genes (cvi/cva, iroN, iss, iucD, sitD, traT, tsh were especially frequent among the isolates (from 66.6% to 89.6%. According to the Clermont method of ECOR phylogenetic typing, isolates belonged to group D (47.2%, to group A (27.8%, to group B2 (17.4% and to group B1 (7.6%; the group B2 isolates contained the highest number of virulence-associated genes. Clonal relationship analysis using the ARDRA method revealed a similarity level of 57% or higher among isolates, but no endemic clone. The virulence of the isolates was confirmed in vivo in one-day-old chicks. Most isolates (72.9% killed all infected chicks within 7 days, and 65 isolates (38.1% killed most of them within 24 hours. In order to analyze differences in virulence among the APEC isolates, we created a pathogenicity score by combining the times of death with the clinical symptoms noted. By looking for significant associations between the presence of virulence-associated genes and the pathogenicity score, we found that the presence of genes for invasins ibeA and gimB and for group II capsule KpsMTII increased virulence, while the presence of pic decreased virulence. The fact that ibeA, gimB and KpsMTII are characteristic of neonatal meningitis E. coli (NMEC suggests that genes of NMEC in APEC increase virulence of strains.

The rhizosphere microbial community in a multiple parallel mineralization system suppresses the pathogenic fungus Fusarium oxysporum.

Science.gov (United States)

Fujiwara, Kazuki; Iida, Yuichiro; Iwai, Takashi; Aoyama, Chihiro; Inukai, Ryuya; Ando, Akinori; Ogawa, Jun; Ohnishi, Jun; Terami, Fumihiro; Takano, Masao; Shinohara, Makoto

2013-12-01

The rhizosphere microbial community in a hydroponics system with multiple parallel mineralization (MPM) can potentially suppress root-borne diseases. This study focused on revealing the biological nature of the suppression against Fusarium wilt disease, which is caused by the fungus Fusarium oxysporum, and describing the factors that may influence the fungal pathogen in the MPM system. We demonstrated that the rhizosphere microbiota that developed in the MPM system could suppress Fusarium wilt disease under in vitro and greenhouse conditions. The microbiological characteristics of the MPM system were able to control the population dynamics of F. oxysporum, but did not eradicate the fungal pathogen. The roles of the microbiological agents underlying the disease suppression and the magnitude of the disease suppression in the MPM system appear to depend on the microbial density. F. oxysporum that survived in the MPM system formed chlamydospores when exposed to the rhizosphere microbiota. These results suggest that the microbiota suppresses proliferation of F. oxysporum by controlling the pathogen's morphogenesis and by developing an ecosystem that permits coexistence with F. oxysporum. © 2013 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Pathogenicity of isolates of Colletotrichum spp.: The causal agents of anthracnose

OpenAIRE

Živković, Svetlana; Dolovac, Nenad; Popović, Tatjana; Stojanović, Saša

2012-01-01

The pathogenic characteristics of 20 isolates of Colletotrichum spp. originating from pear, apple, sour cherry and tomato fruits, as well as reference strains of C. acutatum (CBS 294.67) and C. gloeosporioides (CBS 516.97) are presented in this paper. In the studies of host range of isolates of Colletotrichum spp. were included 17 plant species. Nine days after artificial inoculation all tested isolates were caused anthracnose lesion on fruits of apple, pear, peach, apricot, sour cherry, swee...

Pathogenic characteristics of yeasts isolated from vaginal secretion preserved under mineral oil

Directory of Open Access Journals (Sweden)

B Severo Gomes

2011-01-01

Full Text Available In order to evaluate the pathogenicity of yeasts isolated from vaginal secretion of pregnant and non-pregnant women - stored in mineral oil at the URM Mycology Collection, Department of Mycology, Federal University of Pernambuco - 30 samples belonging to the genera Candida, Rhodotorula, Trichosporon, and Kloeckera, were studied regarding their pathogenic characteristics, ability to grow at room temperature (28°C ± 1°C, 37°C, and 42°C for 72 hours, and production of both phospholipase and proteinase. Results showed that all 30 isolates (100% were able to grow at room temperature and 37°C, and that 17 samples (57% were able to grow at 42°C. Evaluation of enzymatic activity showed protease activity in only two isolates (7%, namely C. maritima and C. obtusa. Phospholipase activity was detected in 20 isolates (67% using soy lecithin as substrate at different temperatures. The characterization of yeasts isolated from vaginal secretion and determination of their enzymatic activity may contribute to understanding the epidemiology of vulvovaginitis and assist in the treatment of patients.

Molecular identification and pathogenicity of Citrobacter and Serratia species isolated from cultured Oreochromis niloticus

Directory of Open Access Journals (Sweden)

Manal I. El-Barbary

2017-09-01

Full Text Available This study aimed to isolate and characterize some pathogenic bacterial strains belonging to the family Enterobacteriaceae. They had been isolated from gills, liver, kidney and skin of naturally infected Oreochromis niloticus and had been identified by biochemical test and 16S rRNA gene using four universal primers. Additionally, the isolates were tested for antimicrobial susceptibility, histopathological alterations of liver, kidney and gills and the pathogenicity of the identified isolates for O. niloticus. The results of phylogenetic analysis placed the isolates in the family Enterobacteriaceae (genera Serratia and Citrobacter based on 99% homology. The primer pair (17F and 1390R is the most appropriate pair of universal primers employed for the identification of 16S rRNA gene as it covers as much as possible of the variable regions (Vs. V1 and V2 regions of 16S rRNA gene presented weak evidence of the diversity of the genera Serratia. The mortality rate was 40–60% after challenging O. niloticus by identified isolates, which revealed its sensitivity to ciprofloxacin and norfloxacin. Histological changes showed dilation in sinusoids with severe vacuolar degeneration in the liver, tubular degeneration and hemorrhage between renal tubules with pyknotic nuclei in the kidney, epithelial hyperplasia, aneurism and evident epithelium interstitial edema in gills of O. niloticus. This study concluded that these isolates should be considered as an opportunistic pathogen of O. niloticus. The study also states that the sequencing of 16S rRNA is an important tool for the identification of unknown bacterial species of fish pathogen. Keywords: Citrobacter sp., Serratia sp., Phylogenetic analysis, Histology, Antibiotic sensitivity, Oreochromis niloticus

Microbial contamination of red meat and consideration of gamma irradiation effects for increasing the shelf-life and decontamination of pathogenic microorganisms

International Nuclear Information System (INIS)

Motamedee Sadeh, F.; Majd, F.; Fathollahee, H.; Arbabi, K.; Mohammad Beygi Abhari, M.

2003-01-01

Red meat has a lot of microbial flora from different sources. Prevention of outbreak of food born diseases that are caused by pathogenic agents and prevention of microbial spoilage of meat that makes many losses to the human health and economic of society are very important. Also, different methods for decreasing the microbial flora under a standard allowance for increasing the shelf life and decontamination of microbial pathogens have been proposed. In this research, irradiation technique was used for this purposes. After drawing dose/survival curves for all kinds of meats microbial contamination, an optimum dose of 3 kGy for decreasing the contamination and specially for decontamination of salmonella was obtained. When meat is irradiated by 3 kGy gamma rays, it can be kept in a 4-7 d ig C refrigerator for 2 week without appearing any spoilage nor color changes or odor. Also, some of biochemical factors were analyzed and amounts of 16 amino acids were measured in the irradiated and controlled samples and no difference was observed between the samples

Prevalence of plant beneficial and human pathogenic bacteria isolated from salad vegetables in India.

Science.gov (United States)

Nithya, Angamuthu; Babu, Subramanian

2017-03-14

The study aimed at enumerating, identifying and categorizing the endophytic cultivable bacterial community in selected salad vegetables (carrot, cucumber, tomato and onion). Vegetable samples were collected from markets of two vegetable hot spot growing areas, during two different crop harvest seasons. Crude and diluted vegetable extracts were plated and the population of endophytic bacteria was assessed based on morphologically distinguishable colonies. The bacterial isolates were identified by growth in selective media, biochemical tests and 16S rRNA gene sequencing. The endophytic population was found to be comparably higher in cucumber and tomato in both of the sampling locations, whereas lower in carrot and onion. Bacterial isolates belonged to 5 classes covering 46 distinct species belonging to 19 genera. Human opportunistic pathogens were predominant in carrot and onion, whereas plant beneficial bacteria dominated in cucumber and tomato. Out of the 104 isolates, 16.25% are human pathogens and 26.5% are human opportunistic pathogens. Existence of a high population of plant beneficial bacteria was found to have suppressed the population of plant and human pathogens. There is a greater potential to study the native endophytic plant beneficial bacteria for developing them as biocontrol agents against human pathogens that are harboured by plants.

Isolation of pathogenic Yersinia enterocolitica strains from different sources in Izmir region, Turkey.

Science.gov (United States)

Bozcal, Elif; Uzel, Atac; Aydemir, Sohret; Skurnik, Mikael

2015-11-01

Yersinia enterocolitica is a foodborne pathogen that is very rarely encountered in Turkey. In this work, several human, porcine, and environmental samples collected from Izmir region in Turkey were examined for the presence of Y. enterocolitica using different cultivation and enrichment methods. A total of nine pathogenic Y. enterocolitica strains were isolated; five strains from pig stool and manure samples and four strains from waste water samples. On the other hand, no Y. enterocolitica was isolated from human diarrheal stool samples (n = 102) and from 12 gulf, canal, municipal pool, and well water samples. Biochemical and serological characterization of the nine Y. enterocolitica strains revealed that they belonged to three different bioserotypes: 4/O:3, 2/O:9, and 2/O:5,27. All the strains were deemed pathogenic based on virulence factor-specific PCR analysis. Detection of pathogenic Y. enterocolitica strains from the pig and waste water samples from the Izmir region indicates that Y. enterocolitica is a potential risk for public health.

Prevalence and Antibiotic Resistance of Gram-Negative Pathogenic Bacteria Species Isolated from Periplaneta americana and Blattella germanica in Varanasi, India.

Directory of Open Access Journals (Sweden)

D Leshan Wannigama

2014-06-01

Full Text Available Cockroaches are among the medically important pests found within the human habitations that cause serious public health problems. They may harbor a number of pathogenic bacteria on the external surface with antibiotic resistance. Hence, they are regarded as major microbial vectors. This study investigates the prevalence and antibiotic resistance of Gram-negative pathogenic bacteria species isolated from Periplaneta americana and Blattella germanica in Varanasi, India.Totally, 203 adult cockroaches were collected form 44 households and 52 food-handling establishments by trapping. Bacteriological examination of external surfaces of Pe. americana and Bl. germanica were carried out using standard method and antibiotics susceptibility profiles of the isolates were determined using Kirby-Bauer disc diffusion methods.Among the places, we found that 54% had cockroache infestation in households and 77% in food- handling establishments. There was no significant different between the overall bacteria load of the external surface in Pe. americana (64.04% and Bl. germanica (35.96%. However the predominant bacteria on cockroaches were Klebsiella pneumonia, Escherichia coli, Enterobacter aerogenes, and Pseudomonas aeruginosa. However, Kl. pneumoniae and Ps. aeruginosa were the most prevalent, drug-resistant strains were isolated from the cockroaches with 100% resistance to sulfamethoxazole/trimethoprim and ampicillin. For individual strains of bacteria, Escherichia coli was found to have multi-resistance to four antibiotic tested, Citrobacter freundii four, Enterobacter aerogenes and Proteus mirabilis to three.Cockroaches are uniformly distributed in domestic environment, which can be a possible vector for transmission of drug-resistant bacteria and food-borne diseases.

Morphological and molecular characterization, sexual reproduction, and pathogenicity of Setosphaeria rostrata isolates from rice leaf spot.

Science.gov (United States)

Kusai, Nor Azizah; Azmi, Madihah Mior Zakuan; Zainudin, Nur Ain Izzati Mohd; Yusof, Mohd Termizi; Razak, Azmi Abd

2016-09-01

Setosphaeria rostrata, a common plant pathogen causing leaf spot disease, affects a wide range of plant species, mainly grasses. Fungi were isolated from brown spots on rice leaves throughout Peninsular Malaysia, and 45 isolates were identified as Setosphaeria rostrata The isolates were then characterized using morphological and molecular approaches. The mating type was determined using PCR amplification of the mating type alleles, and isolates of opposite mating types were crossed to examine sexual reproduction. Based on nuclear ribosomal DNA ITS1-5.8S-ITS2 region (ITS) and beta-tubulin (BT2) sequences, two phylogenetic trees were constructed using the maximum likelihood method; S. rostrata was clustered in one well-supported clade. Pathogenicity tests showed that S. rostrata isolates are pathogenic, suggesting that it is the cause of the symptoms. Mating-type analyses indicated that three isolates carried the MAT1-1 allele, and the other 42 isolates carried MAT1-2 After isolates with opposite mating types were crossed on Sach's medium and incubated for 3 wk, six crosses produced pseudothecia that contained eight mature ascospores, and 12 other crosses produced numerous pseudothecia with no ascospores. To our knowledge, this is the first report on S. rostrata isolated from leaf spots on rice. © 2016 by The Mycological Society of America.

Shrimp pathogenicity, hemolysis, and the presence of hemolysin and TTSS genes in Vibrio harveyi isolated from Thailand.

Science.gov (United States)

Rattanama, Pimonsri; Srinitiwarawong, Kanchana; Thompson, Janelle R; Pomwised, Rattanaruji; Supamattaya, Kidchakarn; Vuddhakul, Varaporn

2009-09-23

The virulence factors of Vibrio harveyi, the causative agent of luminous vibriosis, are not completely understood. We investigated the correlations between shrimp mortality, hemolysis, the presence of a hemolysin gene (vhh), and a gene involved in the type III secretion system (the Vibrio calcium response gene vcrD). V harveyi HY01 was isolated from a shrimp that died from vibriosis, and 36 other V. harveyi isolates were obtained from fish and shellfish in Hat Yai city, Thailand. An ocean isolate of V. harveyi BAA-1116 was also included. Thirteen isolates including V harveyi HYO1 caused shrimp death 12 h after injection. Most V harveyi isolates in this group (designated as Group A) caused hemolysis on prawn blood agar. None of the shrimp died after injection with V harveyi BAA-1116. Molecular analysis of all V harveyi isolates revealed the presence of vcrD in both pathogenic and non-pathogenic strains. Although vhh was detected in all V harveyi isolates, some isolates did not cause hemolysis, indicating that vhh gene expression might be regulated. Analysis of the V harveyi HYO1 genome revealed a V cholerae like-hemolysin gene, hlyA (designated as hhl). Specific primers designed for hhl detected this gene in 3 additional V harveyi isolates but the presence of this gene was not correlated with pathogenicity. Random amplified polymorphic DNA (RAPD) analysis revealed a high degree of genetic diversity in all V harveyi isolates, and there were no correlations among the hhl-positive isolates or the pathogenic strains.

Isolation and Pathogenicity of Phytophthora Species from Poplar Plantations in Serbia

Directory of Open Access Journals (Sweden)

Ivan Milenković

2018-06-01

Full Text Available During a survey in three declining and three healthy poplar plantations in Serbia, six different Phytophthora species were obtained. Phytophthora plurivora was the most common, followed by P. pini, P. polonica, P. lacustris, P. cactorum, and P. gonapodyides. Pathogenicity of all isolated species to four-month and one-year-old cuttings of Populus hybrid clones I-214 and Pánnonia, respectively, was tested using both a soil infestation and stem inoculation test. Isolates of P. polonica, P. × cambivora, P. cryptogea, and P. × serendipita from other host plants were included as a comparison. In the soil infestation test, the most aggressive species to clone I-214 were P. plurivora, P. × serendipita, and P. pini. On clone Pánnonia, P. gonapodyides and P. pini were the most aggressive, both causing 100% mortality, followed by P. cactorum, P. × cambivora, and P. polonica. In the underbark inoculation test, the susceptibility of both poplar clones to the different Phytophthora species was largely similar, as in the soil infestation test, with the exception of P. polonica, which proved to be only weakly pathogenic to poplar bark. The most aggressive species to clone I-214 was P. pini, while on clone Pánnonia, the longest lesions and highest disease incidence were caused by P. gonapodyides. Phytophthora cactorum and P. plurivora were pathogenic to both clones, whereas P. × cambivora showed only weak pathogenicity. The implications of these findings and possible pathways of dispersion of the pathogens are discussed.

The effect of interactions between a bacterial strain isolated from drinking water and a pathogen surrogate on biofilms formation diverged under static vs flow conditions.

Science.gov (United States)

Dai, D; Raskin, L; Xi, C

2017-12-01

Interactions with water bacteria affect the incorporation of pathogens into biofilms and thus pathogen control in drinking water systems. This study was to examine the impact of static vs flow conditions on interactions between a pathogen and a water bacterium on pathogen biofilm formation under laboratory settings. A pathogen surrogate Escherichia coli and a drinking water isolate Stenotrophomonas maltophilia was selected for this study. Biofilm growth was examined under two distinct conditions, in flow cells with continuous medium supply vs in static microtitre plates with batch culture. E. coli biofilm was greatly stimulated (c. 2-1000 times faster) with the presence of S. maltophilia in flow cells, but surprisingly inhibited (c. 65-95% less biomass) in microtitre plates. These divergent effects were explained through various aspects including surface attachment, cellular growth, extracellular signals and autoaggregation. Interactions with the same water bacterium resulted in different effects on E. coli biofilm formation when culture conditions changed from static to flow. This study highlights the complexity of species interactions on biofilm formation and suggests that environmental conditions such as the flow regime can be taken into consideration for the management of microbial contamination in drinking water systems. © 2017 The Society for Applied Microbiology.

Antibiotic resistance of microbial contaminations isolated from husbandry animals and foodstuffs

Directory of Open Access Journals (Sweden)

Lukáš Hleba

2014-05-01

Full Text Available In this paper the antibiotic resistance of microbial contaminations isolated from husbandry animals and foodstuffs were investigated. Microorganisms isolated from animals and foodstuffs were contaminations of selective media as MacConkey agar for Enterobacteriaceae genera and MRS agar for lactobacilli strains. Microorganisms were isolated and puryfied by agar four ways streak plate method. Identification of isolated microorganisms was done by mass-spectrometry method in MALDI-TOF MS Biotyper. For investigation of antibiotic resistance disc diffusion method by EUCAST was used. In this study Gram-negative and Gram-positive bacteria were identified. The most resistant or multi-resistant bacteria as Pseudomonas aeruginosa, Acinetobacter lwoffi, Lysinibacillus sphaericus, Staphylococcus aureus and Staphylococcus epidermis were determined. Other identified microorganisms were resistant to one antibiotic or not at all.

Methylobacteria isolated from bryophytes and the 2-fold description of the same microbial species.

Science.gov (United States)

Schauer, S; Kutschera, U

2013-02-01

On the surface of healthy land plants (embryophytes), numerous non-pathogenic bacteria have been discovered and described. Among these epiphytic microbes, pink-pigmented facultative methylotrophic microbes of the genus Methylobacterium are of special significance, because these microorganisms consume methanol emitted via the stomatal pores and secrete growth-promoting phytohormones. Methylobacterium funariae, Schauer and Kutschera 2011, a species isolated in our lab from the common cord moss, described as a nova species in this journal, was recently characterized for a second time as a "new taxon" under a different name, "M. bullatum." Based on a phylogenetic analysis, we show that these taxa are identical. In addition, we provide novel information on the exact cell size, and describe the correct type locality of this bacterial species, which was classified as a phytosymbiont. Finally, we discuss the hypothesis that certain methylobacteria may preferentially colonize bryophytes. With reference to our recent discovery that thalli of ferns form, like liverworts and moss protonemata, associations with methylobacteria, we argue that the haploid phase of cryptogames are preferred host organisms of these pink-pigmented microbial phytosymbionts.

Importance of microbial pest control agents and their metabolites In relation to the natural microbiota on strawberry

DEFF Research Database (Denmark)

Jensen, Birgit; Knudsen, Inge M. B.; Jensen, Dan Funck

control. A series of laboratory, growth chamber, semi-field and field experiments using strawberry as a model plant focusing on commercial microbial pest control products (MPCPs) or laboratory MPCAs expected to be on the market within 10 years served as our experimental platform. Initially the background...... level of indigenous microbial communities and their mycotoxins/metabolites on strawberries was examined in a field survey with 4 conventional and 4 organic growers with different production practise and geographic distribution. Culturable bacteria, yeasts and filamentous fungi were isolated...... and identified using both chemotaxonomy (fatty acids and metabolite profiling) and morphological characteristics. Microbial communities on strawberries were complex including potential plant pathogens, opportunistic human pathogens, plant disease biocontrol agents and mycotoxin producers. Bacteria were the most...

Climate change and the potential spreading of marine mucilage and microbial pathogens in the Mediterranean Sea.

Directory of Open Access Journals (Sweden)

Roberto Danovaro

2009-09-01

Full Text Available Marine snow (small amorphous aggregates with colloidal properties is present in all oceans of the world. Surface water warming and the consequent increase of water column stability can favour the coalescence of marine snow into marine mucilage, large marine aggregates representing an ephemeral and extreme habitat. Marine mucilage characterize aquatic systems with altered environmental conditions.We investigated, by means of molecular techniques, viruses and prokaryotes within the mucilage and in surrounding seawater to examine the potential of mucilage to host new microbial diversity and/or spread marine diseases. We found that marine mucilage contained a large and unexpectedly exclusive microbial biodiversity and hosted pathogenic species that were absent in surrounding seawater. We also investigated the relationship between climate change and the frequency of mucilage in the Mediterranean Sea over the last 200 years and found that the number of mucilage outbreaks increased almost exponentially in the last 20 years. The increasing frequency of mucilage outbreaks is closely associated with the temperature anomalies.We conclude that the spreading of mucilage in the Mediterranean Sea is linked to climate-driven sea surface warming. The mucilage can act as a controlling factor of microbial diversity across wide oceanic regions and could have the potential to act as a carrier of specific microorganisms, thereby increasing the spread of pathogenic bacteria.

Molecular characterization of double-stranded RNA virus in Trichomonas vaginalis Egyptian isolates and its association with pathogenicity.

Science.gov (United States)

El-Gayar, Eman K; Mokhtar, Amira B; Hassan, Wael A

2016-10-01

Trichomoniasis is a common human sexually transmitted infection caused by Trichomonas vaginalis. The parasite can be infected with double-stranded RNA viruses (TVV). This viral infection may have important implications on trichomonal virulence and disease pathogenesis. This study aimed to determine the prevalence of T. vaginalis virus among isolates obtained from infected (symptomatic and asymptomatic) women in Ismailia City, Egypt, and to correlate the virus-infected isolates with the clinical manifestations of patients. In addition, the pathogenicity of TVV infected isolates on mice was also evaluated. T. vaginalis isolates were obtained from symptomatic and asymptomatic female patients followed by axenic cultivation in Diamond's TYM medium. The presence of T. vaginalis virus was determined from total extraction of nucleic acids (DNA-RNA) followed by reverse transcriptase-PCR. Representative samples were inoculated intraperitoneally in female albino/BALB mice to assess the pathogenicity of different isolates. A total of 110 women were examined; 40 (36.3 %) samples were positive for T. vaginalis infection. Of these 40 isolates, 8 (20 %) were infected by TVV. Five isolates contained TVV-2 virus species, and the remaining three isolates were infected withTVV-4 variant. A significant association was found between the presence of TVV and particular clinical manifestations of trichomoniasis. Experimental mice infection showed varying degrees of pathogenicity. This is the first report on T. vaginalis infection by TVV in Egypt. The strong association detected between TVV and particular clinical features of trichomoniasis and also the degree of pathogenicity in experimentally infected mice may indicate a possible clinical significance of TVV infection of T. vaginalis isolates.

Biocontrol efficacy of different isolates of Trichoderma against soil borne pathogen Rhizoctonia solani.

Science.gov (United States)

Asad, Saeed Ahmad; Ali, Naeem; Hameed, Abdul; Khan, Sabaz Ali; Ahmad, Rafiq; Bilal, Muhammad; Shahzad, Muhammad; Tabassum, Ayesha

2014-01-01

In this study, the biocontrol abilities of water-soluble and volatile metabolites of three different isolates of Trichoderma (T. asperellum, T. harzianum and Trichoderma spp.) against soil borne plant pathogen Rhizoctonia solani were investigated both in vitro and in vivo. The results showed for the first time that mycelial growth inhibition of the pathogen was 74.4-67.8% with water-soluble metabolites as compared to 15.3-10.6% with volatile metabolites in vitro. In vivo antagonistic activity of Trichoderma isolates against R. solani was evaluated on bean plants under laboratory and greenhouse conditions. We observed that T. asperellum was more effective and consistent, lowering disease incidence up to 19.3% in laboratory and 30.5% in green house conditions. These results showed that three isolates of Trichoderma could be used as effective biocontrol agents against R. solani.

Disruption of microbial biofilms by an extracellular protein isolated from epibiotic tropical marine strain of Bacillus licheniformis.

Directory of Open Access Journals (Sweden)

Devendra H Dusane

Full Text Available BACKGROUND: Marine epibiotic bacteria produce bioactive compounds effective against microbial biofilms. The study examines antibiofilm ability of a protein obtained from a tropical marine strain of Bacillus licheniformis D1. METHODOLOGY/PRINCIPAL FINDINGS: B. licheniformis strain D1 isolated from the surface of green mussel, Perna viridis showed antimicrobial activity against pathogenic Candida albicans BH, Pseudomonas aeruginosa PAO1 and biofouling Bacillus pumilus TiO1 cultures. The antimicrobial activity was lost after treatment with trypsin and proteinase K. The protein was purified by ultrafiltration and size-exclusion chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE and matrix assisted laser desorption/ionization-time of flight (MALDI-TOF analysis revealed the antimicrobial agent to be a 14 kDa protein designated as BL-DZ1. The protein was stable at 75°C for 30 min and over a pH range of 3.0 to 11.0. The sequence alignment of the MALDI-fingerprint showed homology with the NCBI entry for a hypothetical protein (BL00275 derived from B. licheniformis ATCC 14580 with the accession number gi52082584. The protein showed minimum inhibitory concentration (MIC value of 1.6 µg/ml against C. albicans. Against both P. aeruginosa and B. pumilus the MIC was 3.12 µg/ml. The protein inhibited microbial growth, decreased biofilm formation and dispersed pre-formed biofilms of the representative cultures in polystyrene microtiter plates and on glass surfaces. CONCLUSION/SIGNIFICANCE: We isolated a protein from a tropical marine strain of B. licheniformis, assigned a function to the hypothetical protein entry in the NCBI database and described its application as a potential antibiofilm agent.

Disruption of Microbial Biofilms by an Extracellular Protein Isolated from Epibiotic Tropical Marine Strain of Bacillus licheniformis

Science.gov (United States)

Dusane, Devendra H.; Damare, Samir R.; Nancharaiah, Yarlagadda V.; Ramaiah, N.; Venugopalan, Vayalam P.; Kumar, Ameeta Ravi; Zinjarde, Smita S.

2013-01-01

Background Marine epibiotic bacteria produce bioactive compounds effective against microbial biofilms. The study examines antibiofilm ability of a protein obtained from a tropical marine strain of Bacillus licheniformis D1. Methodology/Principal Findings B. licheniformis strain D1 isolated from the surface of green mussel, Perna viridis showed antimicrobial activity against pathogenic Candida albicans BH, Pseudomonas aeruginosa PAO1 and biofouling Bacillus pumilus TiO1 cultures. The antimicrobial activity was lost after treatment with trypsin and proteinase K. The protein was purified by ultrafiltration and size-exclusion chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis revealed the antimicrobial agent to be a 14 kDa protein designated as BL-DZ1. The protein was stable at 75°C for 30 min and over a pH range of 3.0 to 11.0. The sequence alignment of the MALDI-fingerprint showed homology with the NCBI entry for a hypothetical protein (BL00275) derived from B. licheniformis ATCC 14580 with the accession number gi52082584. The protein showed minimum inhibitory concentration (MIC) value of 1.6 µg/ml against C. albicans. Against both P. aeruginosa and B. pumilus the MIC was 3.12 µg/ml. The protein inhibited microbial growth, decreased biofilm formation and dispersed pre-formed biofilms of the representative cultures in polystyrene microtiter plates and on glass surfaces. Conclusion/Significance We isolated a protein from a tropical marine strain of B. licheniformis, assigned a function to the hypothetical protein entry in the NCBI database and described its application as a potential antibiofilm agent. PMID:23691235

Genome sequence of the pathogenic Herbaspirillum seropedicae strain Os34, isolated from rice roots.

Science.gov (United States)

Ye, Weijun; Ye, Shuting; Liu, Jian; Chang, Siping; Chen, Mingyue; Zhu, Bo; Guo, Longbiao; An, Qianli

2012-12-01

Most Herbaspirillum seropedicae strains are beneficial endophytes to plants. In contrast, H. seropedicae strain Os34, isolated from rice roots, is pathogenic. The draft genome sequence of strain Os34 presented here allows in-depth comparative genome analyses to understand the specific mechanisms of beneficial and pathogenic Herbaspirillum-plant interactions.

Genome sequence of the pathogenic Herbaspirillum seropedicae strain Os45, isolated from rice roots.

Science.gov (United States)

Zhu, Bo; Ye, Shuting; Chang, Siping; Chen, Mingyue; Sun, Li; An, Qianli

2012-12-01

Most Herbaspirillum seropedicae strains are beneficial to plants. In contrast, H. seropedicae strain Os45, isolated from rice roots, is pathogenic. The draft genome sequence of strain Os45 presented here allows an in-depth comparative genome analysis to understand the subtle mechanisms of beneficial and pathogenic Herbaspirillum-plant interactions.

Draft genomic sequencing of six potential extraintestinal pathogenic Escherichia coli isolates from retail chicken meat.

Science.gov (United States)

Potential Extraintestinal pathogenic Escherichia coli isolates DP254, WH333, WH398, F356, FEX675 and FEX725 were isolated from retail chicken meat products. Here, we report the draft genome sequences for these six E. coli isolates, which are currently being used in food safety research....

Potential for Combined Biocontrol Activity against Fungal Fish and Plant Pathogens by Bacterial Isolates from a Model Aquaponic System

Directory of Open Access Journals (Sweden)

Ivaylo Sirakov

2016-11-01

Full Text Available One of the main challenges in aquaponics is disease control. One possible solution for this is biological control with organisms exerting inhibitory effects on fish and plant pathogens. The aim of this study was to examine the potential of isolating microorganisms that exert an inhibitory effect on both plant and fish pathogens from an established aquaponic system. We obtained 924 isolates on selective King’s B agar and 101 isolates on MRS agar from different compartments of a model aquaponic system and tested them for antagonism against the plant pathogen Pythium ultimum and fish pathogen Saprolegnia parasitica. Overall, 42 isolates were able to inhibit both fungi. Although not yet tested in vivo, these findings open new options for the implementation of biological control of diseases in aquaponics, where plants and fish are cultivated in the same water recirculating system.

Isolation and Identification of L-asparaginase producing Erwinia strains which isolated from Potato Farms

Directory of Open Access Journals (Sweden)

Arastoo Badoei-Dalfard

2016-09-01

Full Text Available Introduction: L-Asparaginase can be effectively used for the treatment of lymphoblastic leukemia. The rapid growth of cancer cells are needed for L-asparagine abundant storage. L-asparaginase catalyzes the hydrolysis of L-asparagine into L-aspartic acid and ammonia. The purpose of this study was to isolate and identify the L-asparaginase producing Erwinia strains from the potato farms of Jiroft. Materials and methods: Pectolytic Erwinia species isolated from crumbling potato in M9 medium. The desired L-asparaginase producing bacteria were isolated based on the color changes. Biochemical-microbial and the plant pathogenicity tests of these strains were also investigated with potato and geranium. The L-asparaginase production and molecular detection of these Erwinia strains were also investigated. Results: In this study, L-asparaginase producing Erwinia was isolated on the CVP and M9 mediums. The inoculation of Erwinia strains on the potato and geranium plants showed that Er8 and Er11 species have the ability to cause plant pathogenicity. Results showed that the maximum pathogenicity of Er8 and Er11 was observed after 48 and 15 h of inoculation in potato and geranium plants, respectively. 16S rDNA sequencing and phylogenetic analyses exhibited that Er8 and Er11 strains were similar to Erwinia chrysanthemi with 98% homology. Discussion and conclusion: Because of several applications of the Erwinia L-asparaginase in various fields, isolated Erwinia and their L-asparaginase can be suitable for applied utilization.

Isolation and characterization of actinomycete antagonists of a fungal root pathogen.

Science.gov (United States)

Crawford, D L; Lynch, J M; Whipps, J M; Ousley, M A

1993-11-01

By use of selective media, 267 actinomycete strains were isolated from four rhizosphere-associated and four non-rhizosphere-associated British soils. Organic media with low nutrient concentrations were found to be best for isolating diverse actinomycetes while avoiding contamination and overgrowth of isolation media by eubacteria and fungi. While all isolates grew well at pHs 6.5 to 8.0, a few were unable to grow at pH 6.0 and a significant number failed to grow at pH 5.5. Eighty-two selected isolates were screened for in vitro antagonism towards Pythium ultimum by use of a Difco cornmeal agar assay procedure. Five isolates were very strong antagonists of the fungus, four were strong antagonists, and ten others were weakly antagonistic. The remaining isolates showed no antagonism by this assay. Additional studies showed that several of the P. ultimum antagonists also strongly inhibited growth of other root-pathogenic fungi. Twelve isolates showing antifungal activity in the in vitro assay were also tested for their effects on the germination and short-term growth of lettuce plants in glasshouse pot studies in the absence of pathogens. None of the actinomycetes prevented seed germination, although half of the isolates retarded seed germination and outgrowth of the plants by 1 to 3 days. During 18-day growth experiments, biomass yields of some actinomycete-inoculated plants were reduced in comparison with untreated control plants, although all plants appeared healthy and well rooted. None of the actinomycetes significantly enhanced plant growth over these short-term experiments. For some, but not all, actinomycetes, some correlations between delayed seed germination and reduced 18-day plant biomass yields were seen. For others, plant biomass yields were not reduced despite an actinomycete-associated delay in seed germination and plant outgrowth. Preliminary glasshouse experiments indicated that some of the actinomycetes protect germinating lettuce seeds against

Limitations of the Current Microbial Identification System for Identification of Clinical Yeast Isolates

Science.gov (United States)

Kellogg, James A.; Bankert, David A.; Chaturvedi, Vishnu

1998-01-01

The ability of the rapid, computerized Microbial Identification System (MIS; Microbial ID, Inc.) to identify a variety of clinical isolates of yeast species was compared to the abilities of a combination of tests including the Yeast Biochemical Card (bioMerieux Vitek), determination of microscopic morphology on cornmeal agar with Tween 80, and when necessary, conventional biochemical tests and/or the API 20C Aux system (bioMerieux Vitek) to identify the same yeast isolates. The MIS chromatographically analyzes cellular fatty acids and compares the results with the fatty acid profiles in its database. Yeast isolates were subcultured onto Sabouraud dextrose agar and were incubated at 28°C for 24 h. The resulting colonies were saponified, methylated, extracted, and chromatographically analyzed (by version 3.8 of the MIS YSTCLN database) according to the manufacturer’s instructions. Of 477 isolates of 23 species tested, 448 (94%) were given species names by the MIS and 29 (6%) were unidentified (specified as “no match” by the MIS). Of the 448 isolates given names by the MIS, only 335 (75%) of the identifications were correct to the species level. While the MIS correctly identified only 102 (82%) of 124 isolates of Candida glabrata, the predictive value of an MIS identification of unknown isolates as C. glabrata was 100% (102 of 102) because no isolates of other species were misidentified as C. glabrata. In contrast, while the MIS correctly identified 100% (15 of 15) of the isolates of Saccharomyces cerevisiae, the predictive value of an MIS identification of unknown isolates as S. cerevisiae was only 47% (15 of 32), because 17 isolates of C. glabrata were misidentified as S. cerevisiae. The low predictive values for accuracy associated with MIS identifications for most of the remaining yeast species indicate that the procedure and/or database for the system need to be improved. PMID:9574676

Potential probiotic characteristics of Lactobacillus and Enterococcus strains isolated from traditional dadih fermented milk against pathogen intestinal colonization.

Science.gov (United States)

Collado, M Carmen; Surono, Ingrid S; Meriluoto, Jussi; Salminen, Seppo

2007-03-01

Traditional fermented buffalo milk in Indonesia (dadih) has been believed to have a beneficial impact on human health, which could be related to the properties of the lactic acid bacteria (LAB) involved in its fermentation process. In previous studies, it was discovered that strains of dadih lactic isolates possessed some beneficial properties in vitro. In the present study, the adhesion capacity of specific LAB isolates from dadih to intestinal mucus was analyzed. Further, the ability to inhibit model human pathogens and displace them from mucus was assessed. The adhesion of tested LAB strains was strain-dependent and varied from 1.4 to 9.8%. The most adhesive Lactobacillus plantarum strain was IS-10506, with 9.8% adhesion. The competition assay between dadih LAB isolates and pathogens showed that a 2-h preincubation with L. plantarum at 37 degrees C significantly reduced pathogen adhesion to mucus. All tested LAB strains displaced and inhibited pathogen adhesion, but the results were strain-specific and dependent on time and pathogen strains. In general, L. plantarum IS-10506 showed the best ability against pathogen adhesion.

Conserved Patterns of Microbial Immune Escape: Pathogenic Microbes of Diverse Origin Target the Human Terminal Complement Inhibitor Vitronectin via a Single Common Motif.

Directory of Open Access Journals (Sweden)

Teresia Hallström

Full Text Available Pathogenicity of many microbes relies on their capacity to resist innate immunity, and to survive and persist in an immunocompetent human host microbes have developed highly efficient and sophisticated complement evasion strategies. Here we show that different human pathogens including Gram-negative and Gram-positive bacteria, as well as the fungal pathogen Candida albicans, acquire the human terminal complement regulator vitronectin to their surface. By using truncated vitronectin fragments we found that all analyzed microbial pathogens (n = 13 bound human vitronectin via the same C-terminal heparin-binding domain (amino acids 352-374. This specific interaction leaves the terminal complement complex (TCC regulatory region of vitronectin accessible, allowing inhibition of C5b-7 membrane insertion and C9 polymerization. Vitronectin complexed with the various microbes and corresponding proteins was thus functionally active and inhibited complement-mediated C5b-9 deposition. Taken together, diverse microbial pathogens expressing different structurally unrelated vitronectin-binding molecules interact with host vitronectin via the same conserved region to allow versatile control of the host innate immune response.

Growth inhibition of shrimp pathogens by isolated gastrointestinal microflora of Macrobrachium rosenbergii de Man

Directory of Open Access Journals (Sweden)

Seehanat, S.

2005-02-01

Full Text Available The useful bacteria which were isolated from the gastrointestinal tract of freshwater prawn (Macrobrachium rosenbergii de Man, cultivated in earthen pond at Maha Sarakham province, Thailand, consisted of 14 isolates of Bacillus (B1 – B14 and 18 isolates of Lactic acid bacteria (LA1 – LA18. The abilities of all isolated bacteria on growth inhibition of pathogenic bacteria (Escherichia coli, Bacillus cereus, Aeromonas hydrophila and Pseudomonas aeruginosa were studied by paperdisc plate method. The results showed that the Bacillus B2 and B5 were unable to inhibit the growth of all of the tested pathogens. Bacillus B1, B10 and B12 were capable of inhibiting the growth of 3 of 4 tested pathogen strains. Although all of the isolated lactic acid bacteria (LA1 –LA18 could not inhibit the E. coli growth, all of them could inhibit the growth of B. cereus. The isolated lactic acid bacteria which were capable of inhibiting the growth of 3 tested pathogen strains (excluded E. coli were LA12 , LA13 , LA14 , LA15 , LA16 , LA17 and LA18. In order to select the high potential strain of bacteria for using as probiotics, Bacillus B1 , B3 , B4 , B10 and B12 and lactic acid bacteria LA12 , LA13 , LA14 , LA15 , LA16 , LA17 and LA18 were tested for their growth abilities in various growth conditions. The tested growth conditions included various concentrations of the bile salt and salt (NaCl and various pH and temperatures. The results revealed that Bacillus B1 and B10 and lactic acid bacteria LA13 , LA16 and LA18 exhibited high potential for using as probiotics. The results of biochemical test for identification of these high potential strains showed that Bacillus B1 and B10 were possibly B. licheniformis and B. thuringiensis respectively. The lactic acid bacteria LA13 , LA16 and LA18 were possibly the same strain and belonged to the genus Pediococcus.

Isolation and identification of local bacteria endophyte and screening of its antimicrobial property against pathogenic bacteria and fungi

Science.gov (United States)

Fikri, Ahmad Syairazie Ibrahim; Rahman, Irman Abdul; Nor, Norefrina Shafinaz Md; Hamzah, Ainon

2018-04-01

Endophytes are organisms, often fungi and bacteria that live in living plant cells. These organisms reside in the living tissues of the host plant in a variety of relationships, ranging from symbiotic to slightly pathogenic. The endophytes may produce a plethora of substances that have potential to be used in modern medicine, agriculture and industry. The aims of this study are to isolate, identify and screening antimicrobial activity of bacterial endophytes. The endophytes were isolated using nutrient agar, incubated at 37°C for 48 hours. Identification of the isolates were done based on morphological characteristics, biochemical tests and 16S rDNA molecular analysis. Disk diffusion method was used to screen for antimicrobial activity of metabolites from endophytes against pathogenic bacteria. Screening for antifungal activity of selected endophytes was done using dual culture method againts pathogenic fungi followed by Kirby-Bauer method. Results showed endophytes designated as B2c and B7b have positive antimicrobial activity. The metabolites from isolate B2c showed antimicrobial activity against pathogenic bacteria methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus and Staphylococcus epidermis, while isolate B7b have positive activities againts MRSA, S. aureus and Pseudomonas aeruginosa. Isolates B2c displayed antifungal activity against Fusarium oxysporum, Fusarium solani, Phytophthora palmivora and Colletotrichum gloeosporioides. Identification using biochemical tests and 16S rDNA sequences identified isolate B2c as Pseudomonas resinovorans with 97% homology and isolate B7b as Bacillus subtilis with 98% homology.

Isolate-dependent growth, virulence, and cell wall composition in the human pathogen Aspergillus fumigatus.

Directory of Open Access Journals (Sweden)

Nansalmaa Amarsaikhan

Full Text Available The ubiquitous fungal pathogen Aspergillus fumigatus is a mediator of allergic sensitization and invasive disease in susceptible individuals. The significant genetic and phenotypic variability between and among clinical and environmental isolates are important considerations in host-pathogen studies of A. fumigatus-mediated disease. We observed decreased radial growth, rate of germination, and ability to establish colony growth in a single environmental isolate of A. fumigatus, Af5517, when compared to other clinical and environmental isolates. Af5517 also exhibited increased hyphal diameter and cell wall β-glucan and chitin content, with chitin most significantly increased. Morbidity, mortality, lung fungal burden, and tissue pathology were decreased in neutropenic Af5517-infected mice when compared to the clinical isolate Af293. Our results support previous findings that suggest a correlation between in vitro growth rates and in vivo virulence, and we propose that changes in cell wall composition may contribute to this phenotype.

MICROBIAL PROFILE AND ANTIBIOTIC SUSCEPTIBILITY PATTERNS OF PATHOGENS CAUSING VENTILATOR- ASSOCIATED PNEUMONIA AT INTENSIVE CARE UNIT, SESTRE MILOSRDNICE UNIVERSITY HOSPITAL CENTER, ZAGREB, CROATIA.

Science.gov (United States)

Turković, Tihana Magdić; Grginić, Ana Gverić; Cucujić, Branka Đuras; Gašpar, Božena; Širanović, Mladen; Perić, Mladen

2015-06-01

Ventilator-associated pneumonia (VAP) is very common in many intensive care Units, but there are still many uncertainties about VAP, especially about the choice of initial empiric antibiotics. The incidence of specific pathogens with different susceptibility patterns causing VAP varies from hospital to hospital. This is the reason why empiric initial antibiotic treatment for VAP should be based not only on general guidelines (that recommend therapy according to the presence of risk factors for multidrug-resistant bacteria), but also on up-to-date information on local epidemiology. The aim of this study was to determine the microbial profile of pathogens causing VAP and their antibiotic susceptibility patterns. The study was conducted in the 15-bed surgical and neurosurgical Intensive Care Unit, Department of Anesthesiology and Intensive Care, Sestre milosrdnice University Hospital Center, Zagreb, Croatia. Retrospective data were collected from September 2009 to March 2013. All patients that developed VAP during the study period were eligible for the study. According to study results, the incidence of VAP was 29.4%. The most commonly isolated bacterium was Staphylococcus aureus (21.1%), followed by Pseudomonas aeruginosa (19.0%) and Acinetobacter species (13.6%). All Staphylococcus aureus isolates were susceptible to vancomycin and linezolid. Pseudomonas aeruginosa showed 100% susceptibility to cefepime and very high susceptibility to pip'eracillin-tazobactam (96%), ceftazidime (93%) and ciprofloxacin (89%). Ampicillin-sulbactam was highly effective for Acinetobacter species, showing resistance in only 8% of isolates. In conclusion, according to study data, appropriate empiric antibiotic therapy for patients with VAP without risk factors for multidrug-resistant bacteria is ceftriaxone and for patients with risk factors for multidrug-resistant bacteria ampicillin-sulbactam plus cefepime plus vancomycin or linezolid.

Isolation and characterization of the microbial community of a freshwater distribution system

International Nuclear Information System (INIS)

Balamurugan, P.; Subba Rao, T.

2015-01-01

This investigation provides generic information on culturable and non-culturable microbial community of a freshwater distribution system. Culture based and culture independent (16S rRNA gene sequencing) techniques were used to identify the resident microbial community of the system. Selective isolation of the fouling bacteria such as biofilm formers and corrosion causing bacteria was also attempted. Denaturing gradient gel electrophoresis (DGGE) was carried out and the bands were sequenced to obtain the diversity of the total bacterial types. Pseudomonas aeruginosa was predominantly observed in most of the samples. A variety of bacteria, related to groups such as Cyanobacteria, Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes were identified. The study highlights the relevance of the observed microbial diversity with respect to material deterioration in a freshwater distribution system, which can aid in designing effective control methods. (author)

Isolation, pathogenicity and characterization of a novel bacterial pathogen Streptococcus uberis from diseased mandarin fish Siniperca chuatsi.

Science.gov (United States)

Luo, Xia; Fu, Xiaozhe; Liao, Guoli; Chang, Ouqin; Huang, Zhibin; Li, Ningqiu

2017-06-01

In recent years, mandarin fish had a high mortality rate associated with abnormal swimming, exophthalmia, corneal opacity and eye hemorrhage on a fish farm located at Foshan city, Guangdong province, China. Three isolates of Gram-positive, chain-forming cocci were recovered from moribund fish, and designated as SS131025-1, SS131025-2, and SS131025-3. These isolates were identified as Streptococcus uberis according to their morphologic and physio-biochemical characteristics as well as phylogenetic analysis based on their 16S rRNA and GapC gene sequences. The pathogenicity of S. uberis to mandarin fish was determined by challenge experiments. Results of artificial challenge showed S. uberis infected healthy mandarin fish and lead to death by eyeball injection or immersion route, and the LD 50 of SS131025-1 with eyeball injection was 2.0 × 10 6.42  CFU per fish. Moreover extracellular product (ECP) of the isolated S.uberis induced CPB cell apoptosis and cause death of mandarin fish. In addition, these S. uberis strains could also infect tilapia, but not grass carp and crucian carp, and grew in brain-heart infusion broth with an optimal temperature of 37 °C, pH of 7.0, and salinity of 0%. Antibiotic sensitivity testing indicated that these isolates were susceptible to rifampicin and furazolidone but resistant to 20 kinds of antibiotics. Histopathologically, infection with S. uberis could cause serious pathological changes in brain tissues such as vacuoles in matrix, swollen mitochondria with lysis of cristae and disintegration, and lots of coccus was observed both under electron and light microscope. These results shed some light on the pathogenicity of the isolates and how to prevent and control S. uberis infection in mandarin fish. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nucleic acid probes in the diagnosis of human microbial pathogens

International Nuclear Information System (INIS)

Hyypia, T.; Huovinen, P.; Holmberg, M.; Pettersson, U.

1989-01-01

The development of effective vaccines and antimicrobial drugs against infectious diseases has been among the most successful achievements in modern medicine. The control of these diseases requires efficient diagnostic methods for the evaluation of the prevalence of diseases and for initiation of specific treatment. Virtually all known microbes can be specifically identified today but in many cases further development is needed for more accurate, rapid, easy-to-use, and inexpensive diagnostic assays. Cell culture facilities are needed for the isolation of viruses in clinical specimens. Any gene of any known microorganism can be cloned in a vector and produced in large amounts economically and then used in diagnostic assays for the identification of the pathogen. The application of the nucleic acid hybridization methods in detection of human pathogens has received considerable attention during the past few years. This paper presents examples of this application of gene technology

Pathogenic strains of Yersinia enterocolitica isolated from domestic dogs (Canis familiaris) belonging to farmers are of the same subtype as pathogenic Y. enterocolitica strains isolated from humans and may be a source of human infection in Jiangsu Province, China.

Science.gov (United States)

Wang, Xin; Cui, Zhigang; Wang, Hua; Tang, Liuying; Yang, Jinchuan; Gu, Ling; Jin, Dong; Luo, Longze; Qiu, Haiyan; Xiao, Yuchun; Xiong, Haiping; Kan, Biao; Xu, Jianguo; Jing, Huaiqi

2010-05-01

We isolated 326 Yersinia enterocolitica strains from 5,919 specimens from patients with diarrhea at outpatient clinics, livestock, poultry, wild animals, insect vectors, food, and the environment in the cities of Nantong and Xuzhou in Jiangsu Province, China, from 2004 to 2008. The results showed that the 12 pathogenic strains were of the O:3 serotype. Six strains were isolated from domestic dogs (Canis familiaris) belonging to farmers and were found to be the primary carriers of pathogenic Y. enterocolitica strains, especially in Xuzhou. Pulsed-field gel electrophoresis analysis of the pathogenic strains from dogs belonging to farmers showed that they shared the same patterns as strains from diarrhea patients isolated in 1994. This indicates that the strains from domestic dogs have a close correlation with the strains causing human infections.

Quantification of pathogenic microorganisms and microbial indicators in three wastewater reclamation and managed aquifer recharge facilities in Europe.

Science.gov (United States)

Levantesi, Caterina; La Mantia, Rosanna; Masciopinto, Costantino; Böckelmann, Uta; Ayuso-Gabella, M Neus; Salgot, Miquel; Tandoi, Valter; Van Houtte, Emmanuel; Wintgens, Thomas; Grohmann, Elisabeth

2010-10-01

Managed Aquifer Recharge (MAR) is becoming an attractive option for water storage in water reuse processes as it provides an additional treatment barrier to improve recharged water quality and buffers seasonal variations of water supply and demand. To achieve a better understanding about the level of pathogenic microorganisms and their relation with microbial indicators in these systems, five waterborne pathogens and four microbial indicators were monitored over one year in three European MAR sites operated with reclaimed wastewater. Giardia and Cryptosporidium (oo)cysts were found in 63.2 and 36.7% of the samples respectively. Salmonella spp. and helminth eggs were more rarely detected (16.3% and 12.5% of the samples respectively) and Campylobacter cells were only found in 2% of samples. At the Belgian site advanced tertiary treatment technology prior to soil aquifer treatment (SAT) produced effluent of drinking water quality, with no presence of the analysed pathogens. At the Spanish and Italian sites amelioration of microbiological water quality was observed between the MAR injectant and the recovered water. In particular Giardia levels decreased from 0.24-6.14 cysts/L to 0-0.01 cysts/L and from 0.4-6.2 cysts/L to 0-0.07 cysts/L in the Spanish and Italian sites respectively. Salmonella gene copies and Giardia cysts were however found in the water for final use and/or the recovered groundwater water at the two sites. Significant positive Spearman correlations (p<0.05, r(s) range: 0.45-0.95) were obtained, in all the three sites, between Giardia cysts and the most resistant microbial markers, Clostridium spores and bacteriophages. Copyright 2010 Elsevier B.V. All rights reserved.

Diverse pathogenicity of equine herpesvirus 1 (EHV-1) isolates in CBA mouse model.

Science.gov (United States)

Yu, Mi Htay Htay; Kasem, Samy Gomaa Ahmed; Tsujimura, Koji; Matsumura, Tomio; Yanai, Tokuma; Yamaguchi, Tsuyoshi; Ohya, Kenji; Fukushi, Hideto

2010-03-01

The pathogenicity of equine herpesvirus 1 (EHV-1) isolates of Japan were evaluated by using the CBA mouse model. CBA mice were inoculated with eight Japanese EHV-1 strains (89c1, 90c16, 90c18, 97c11, 98c12, 00c19, 01c1 and HH-1) and one British strain (Ab4p). 89c1 caused slight body weight loss and nervous signs in mice at 8 days post infection (dpi). Severe weight loss and nervous signs were observed in mice inoculated with Ab4p at 6 dpi. The other strains did not cause apparent clinical signs. Infectious viruses were recovered from the lungs of all groups at 2 dpi. Histopathological analysis revealed interstitial pneumonia in the lungs of all mice inoculated with EHV-1. Encephalitis or meningoencephalitis was observed in the brains of mice inoculated with 89c1, 90c18, 97c11, 98c12, 01c1 and Ab4p. Japanese EHV-1 strains showed low pathogenicity in CBA mice, whereas the sequential affects of infection are similar to those of the highly pathogenic strain Ab4p. These results suggest that field isolates of EHV-1 have varying degrees of pathogenicity in CBA mice.

Effect of ozonation on microbial fish pathogens, ammonia, nitrate, nitrite, and bod in simulated reuse hatchery water

Energy Technology Data Exchange (ETDEWEB)

Colberg, P.J.; Lingg, A.J.

1978-10-01

The effectiveness of ozone for eliminating fish pathogens and reducing nitrite, ammonia, and BOD associated with reuse hatchery systems was evaluated. Comparative survival rates of four bacterial fish pathogens and a bacterium-protozoan population during batch and continuous flow ozonation indicated a specific microbial ozone demand during batch treatment and 99% mortality of pathogens during continuous flow treatment. Oxidation of carbon and nitrite by ozone was rapid at low ozone concentrations; carbon and ammonia oxidation rates were pH dependent. The oxidation capacity of ozone in water was greatest at elevated pH even though lower ozone concentrations were used. Ozone treatment appears to be successful for disinfecting hatchery makeup water for recycling. However, the economics of such treatment are yet to be determined. (10 graphs, 28 references, 1 table)

Contagem de células somáticas e isolamento de agentes causadores de mastite em búfalas (Bubalus bubalis Somatic cell count and mastitis causing pathogens isolation in water buffaloes (Bubalus bubalis

Directory of Open Access Journals (Sweden)

L.B. Carvalho

2007-02-01

Full Text Available The research was accomplished in eight dairy water buffalo herds, randomically choosen in Região do Alto São Francisco, State of Minas Gerais, Brazil. Information was collected from March to November, 2003 during 270 days of observation. In order to determine the somatic cell count (SCC in presence or absence of microbial isolation, 1,393 samples were collected from 285 lactating females and microbiological exams and SCC were done. Samples obtained from udders without evidence of clinical or subclinical inflammation showed infection for a great variety of microbial mastitis pathogens. The low SCC did not necessarily indicate the absence of intramammary infection, suggesting that SCC patterns used for bovine cannot be appropriate in order to control mastitis in buffalo herds.

Frequency Of Isolation Of Salmonella From Commercial Poultry Feeds And Their Anti-Microbial Resistance Profiles, Imo State, Nigeria

OpenAIRE

Okoli IC; Ndujihe GE; Ogbuewu IP

2006-01-01

This study was conducted to determine the frequency of isolation of salmonella and their microbial resistance profiles across different commercial poultry feeds sold in Imo State, Nigeria. Thirty-six bulk feed samples were colleted from 154 bag across different feed types and brands which included Guinea (GF), Top (TF), Vital (VF), Extra (EF), Animal care (AF) and livestock (LF) feeds. The salmonella isolated were tested against 14 anti-microbial drugs using the disc diffusion method. Bacteri...

Isolation and Pathogenicity of Streptococcus iniae in Cultured Red Hybrid Tilapia in Malaysia.

Science.gov (United States)

Rahmatullah, M; Ariff, M; Kahieshesfandiari, M; Daud, H M; Zamri-Saad, M; Sabri, M Y; Amal, M N A; Ina-Salwany, M Y

2017-12-01

This study describes the isolation and pathogenicity of Streptococcus iniae in cultured red hybrid tilapia (Nile Tilapia Oreochromis niloticus × Mozambique Tilapia O. mossambicus) in Malaysia. The isolated gram-positive S. iniae appeared punctiform, transparently white, catalase and oxidase negative and produced complete β-hemolysis on blood agar, while a PCR assay resulted in the amplification of the 16 S rRNA gene and lactate oxidase encoded genes. The isolate was sensitive to tetracycline, vancomycin, and bacitracin but was resistant to streptomycin, ampicillin, penicillin, and erythromycin. Pathogenicity trials conducted in local red hybrid tilapia (mean ± SE = 20.00 ± 0.45 g) showed 90.0, 96.7, and 100.0% mortality within 14 d postinfection following intraperitoneal exposure to 10 4 , 10 6 , and 10 8 CFU/mL of the pathogen, respectively. The clinical signs included erratic swimming, lethargy, and inappetance at 6 h postinfection, while mortality was recorded at less than 24 h postinfection in all infected groups. The LD 50-336 h of S. iniae against the red hybrid tilapia was 10 2 CFU/mL. The post mortem examinations revealed congested livers, kidneys, and spleens of the infected fish. This is the first report of S. iniae experimental infection in cultured red hybrid tilapia in Malaysia. Received January 20, 2017; accepted July 16, 2017.

Microbial Indicators, Pathogens, and Antibiotic Resistance in Groundwater Impacted by Animal Farming: Field Scale to Basin Scale

Science.gov (United States)

Harter, T.; Li, X.; Atwill, E. R.; Packman, A. I.

2015-12-01

Several surveys of microbial indicators and pathogens were conducted to determine the impact of confined animal farming operations (CAFOs) on shallow, local, and regional groundwater quality in the Central Valley aquifer system, California. The aquifer system consists of highly heterogeneous, alluvial, unconsolidated coarse- to fine-grained sediments and is among the largest aquifers in the U.S.. Overlying landuse includes 3 million ha of irrigated agriculture and 1.7 million mature dairy cows in nearly 1,500 CAFOs. A multi-scale survey of water-borne indicator pathogens (Enterococcus spp. and generic E. coli) and of three water-borne pathogens (Campylobacter, Salmonella, and E. coli O157:H7) was conducted at five different spatial scales, increasing with distance from animal sources of these enteric microbial organisms: moist surfaces within individual CAFO sub-systems (calf-hutches, heifer corrals, mature cow stalls, hospital barn etc.), first encountered (shallow) groundwater immediately below these sub-systems, production aquifer below CAFOs, production aquifer near CAFOs, and production aquifer away from CAFOs. Where found, indicator pathogens were tested for antibiotic resistance. Hundreds of samples were collected at each scale: continuously during irrigation events and seasonally over a multi-year period at the three smaller site-scales; and in a one-time survey at the two larger, regional scales. All three pathogens were frequently detected in moist surface samples across CAFO sub-systems, albeit at concentrations several orders of magnitude lower than enteric indicators. Two of the three pathogens (but not Campylobacter) were also detected in first encountered groundwater, at 3-9 m below ground surface, in 1% of samples. No pathogens were found at the production aquifer scales. Generic E. coli was detected in ¼ of first encountered groundwater samples, and in 4% of production aquifer samples, while Enterococcus spp. was ubiquitously present across the

Highly pathogenic avian influenza virus (H5N1) isolated from whooper swans, Japan.

Science.gov (United States)

Uchida, Yuko; Mase, Masaji; Yoneda, Kumiko; Kimura, Atsumu; Obara, Tsuyoshi; Kumagai, Seikou; Saito, Takehiko; Yamamoto, Yu; Nakamura, Kikuyasu; Tsukamoto, Kenji; Yamaguchi, Shigeo

2008-09-01

On April 21, 2008, four whooper swans were found dead at Lake Towada, Akita prefecture, Japan. Highly pathogenic avian influenza virus of the H5N1 subtype was isolated from specimens of the affected birds. The hemagglutinin (HA) gene of the isolate belongs to clade 2.3.2 in the HA phylogenetic tree.

Oligo-DNA custom macroarray for monitoring major pathogenic and non-pathogenic fungi and bacteria in the phyllosphere of apple trees.

Science.gov (United States)

He, Ying-Hong; Isono, Sayaka; Shibuya, Makoto; Tsuji, Masaharu; Adkar Purushothama, Charith-Raj; Tanaka, Kazuaki; Sano, Teruo

2012-01-01

To monitor the richness in microbial inhabitants in the phyllosphere of apple trees cultivated under various cultural and environmental conditions, we developed an oligo-DNA macroarray for major pathogenic and non-pathogenic fungi and bacteria inhabiting the phyllosphere of apple trees. First, we isolated culturable fungi and bacteria from apple orchards by an agar-plate culture method, and detected 32 fungal and 34 bacterial species. Alternaria, Aureobasidium, Cladosporium, Rhodotorula, Cystofilobasidium, and Epicoccum genera were predominant among the fungi, and Bacillus, Pseudomonas, Sphingomonas, Methylobacterium, and Pantoea genera were predominant among the bacteria. Based on the data, we selected 29 major non-pathogenic and 12 phytopathogenic fungi and bacteria as the targets of macroarray. Forty-one species-specific 40-base pair long oligo-DNA sequences were selected from the nucleotide sequences of rDNA-internal transcribed spacer region for fungi and 16S rDNA for bacteria. The oligo-DNAs were fixed on nylon membrane and hybridized with digoxigenin-labeled cRNA probes prepared for each species. All arrays except those for Alternaria, Bacillus, and their related species, were specifically hybridized. The array was sensitive enough to detect 10(3) CFU for Aureobasidium pullulans and Bacillus cereus. Nucleotide sequencing of 100 each of independent fungal rDNA-ITS and bacterial 16S-rDNA sequences from apple tree was in agreement with the macroarray data obtained using the same sample. Finally, we analyzed the richness in the microbial inhabitants in the samples collected from apple trees in four orchards. Major apple pathogens that cause scab, Alternaria blotch, and Marssonina blotch were detected along with several non-phytopathogenic fungal and bacterial inhabitants. The macroarray technique presented here is a strong tool to monitor the major microbial species and the community structures in the phyllosphere of apple trees and identify key species

Oligo-DNA custom macroarray for monitoring major pathogenic and non-pathogenic fungi and bacteria in the phyllosphere of apple trees.

Directory of Open Access Journals (Sweden)

Ying-Hong He

Full Text Available BACKGROUND: To monitor the richness in microbial inhabitants in the phyllosphere of apple trees cultivated under various cultural and environmental conditions, we developed an oligo-DNA macroarray for major pathogenic and non-pathogenic fungi and bacteria inhabiting the phyllosphere of apple trees. METHODS AND FINDINGS: First, we isolated culturable fungi and bacteria from apple orchards by an agar-plate culture method, and detected 32 fungal and 34 bacterial species. Alternaria, Aureobasidium, Cladosporium, Rhodotorula, Cystofilobasidium, and Epicoccum genera were predominant among the fungi, and Bacillus, Pseudomonas, Sphingomonas, Methylobacterium, and Pantoea genera were predominant among the bacteria. Based on the data, we selected 29 major non-pathogenic and 12 phytopathogenic fungi and bacteria as the targets of macroarray. Forty-one species-specific 40-base pair long oligo-DNA sequences were selected from the nucleotide sequences of rDNA-internal transcribed spacer region for fungi and 16S rDNA for bacteria. The oligo-DNAs were fixed on nylon membrane and hybridized with digoxigenin-labeled cRNA probes prepared for each species. All arrays except those for Alternaria, Bacillus, and their related species, were specifically hybridized. The array was sensitive enough to detect 10(3 CFU for Aureobasidium pullulans and Bacillus cereus. Nucleotide sequencing of 100 each of independent fungal rDNA-ITS and bacterial 16S-rDNA sequences from apple tree was in agreement with the macroarray data obtained using the same sample. Finally, we analyzed the richness in the microbial inhabitants in the samples collected from apple trees in four orchards. Major apple pathogens that cause scab, Alternaria blotch, and Marssonina blotch were detected along with several non-phytopathogenic fungal and bacterial inhabitants. CONCLUSIONS: The macroarray technique presented here is a strong tool to monitor the major microbial species and the community structures in

Microbial diversity and prevalence of foodborne pathogens in cheap and junk foods consumed by primary schoolchildren.

Science.gov (United States)

Kim, M J; Kim, S A; Kang, Y S; Hwang, I G; Rhee, M S

2013-07-01

Aerobic plate counts (APC), coliforms, Bacillus cereus, Escherichia coli and eight foodborne pathogens were tested in 1008 cheap and junk foods, including candies, dried cakes, chewing gum, chocolate, dried and seasoned seafood, ice cream, and sugary foods. APCs were positive for 342 samples (33·9%), and the majority of the counts were 2-3 log CFU g(-1) or ml(-1) (average: 1·10 log CFU g(-1) or ml(-1) ). Most samples (97·3%) contained no coliforms (average: 0·07 log CFU g(-1) or ml(-1) ). Bacillus cereus was detected in 68 samples (average: 0·14 log CFU g(-1) or ml(-1) ). Escherichia coli and Listeria monocytogenes were detected in 6 and 1 samples, respectively, whereas other foodborne pathogens were not isolated. The highest bacterial counts were associated with dried and seasoned seafood products and dried cakes, suggesting that appropriate regulations of these food types should be considered. Cheap and junk foods were produced mainly in developing countries, but there were no significant differences in the bacterial counts among different countries of origin. The presence of foodborne pathogens may pose a risk for children. These results suggest that there is cause for deeper concern about the safety of these foods and that effective countermeasures should be established to improve their microbiological safety. Food safety is especially important for children, but only limited information is available about the microbiological quality of cheap and junk foods that are consumed frequently by primary schoolchildren (e.g. dried cakes, candies and chocolates). The present study investigated the microbial quality of cheap and junk foods, and our results indicate that these foods are a potential health risk for children, therefore, deeper concern about the safety of these foods and effective countermeasures should be established to improve their microbiological safety. The present study may contribute to the development of an appropriate child food

Metabolites produced by antagonistic microbes inhibit the principal avocado pathogens in vitro

Directory of Open Access Journals (Sweden)

Sara Ramírez R.

2015-04-01

Full Text Available The demand for Hass avocado in the global market exceeds the supply by over 50%. Colombia has a remarkable advantage as a producer in the region due to its high yields. However, the productivity of this crop can be seriously affected by diseases such as root rot, caused by Phytophthora cinnamomi, postharvest body rot and stem end rot, caused by Colletotrichum sp. and Phomopsis sp., respectively. The potential of 76 bacterial isolates obtained from avocado rhizosphere to produce inhibitory metabolites against avocado's pathogens was evaluated. The antagonistic effect of the rhizobacteria against P. cinnamomi, Colletotrichum sp. and Phomopsis sp. was tested through dual cultures. Thirty-six percent of the tested isolates presented inhibition halos against P. cinnamomi, 36% against Colletotrichum sp. and 67% against Phomopsis sp. Additionally, three isolates were selected for fermentation tests using different broth cultures. The extracts obtained from fermentations in the minimal medium of isolates ARP5.1 and AED06 showed inhibitory activity against the evaluated pathogens, but this effect was not observed with the AED26 extract. The media supplemented with copper chloride did not enhance activity of the extracts. These results suggest that using microbial metabolic extracts is a viable alternative for controlling avocado pathogens in vitro.

Pathogenic Strains of Yersinia enterocolitica Isolated from Domestic Dogs (Canis familiaris) Belonging to Farmers Are of the Same Subtype as Pathogenic Y. enterocolitica Strains Isolated from Humans and May Be a Source of Human Infection in Jiangsu Province, China ▿ ‡

Science.gov (United States)

Wang, Xin; Cui, Zhigang; Wang, Hua; Tang, Liuying; Yang, Jinchuan; Gu, Ling; Jin, Dong; Luo, Longze; Qiu, Haiyan; Xiao, Yuchun; Xiong, Haiping; Kan, Biao; Xu, Jianguo; Jing, Huaiqi

2010-01-01

We isolated 326 Yersinia enterocolitica strains from 5,919 specimens from patients with diarrhea at outpatient clinics, livestock, poultry, wild animals, insect vectors, food, and the environment in the cities of Nantong and Xuzhou in Jiangsu Province, China, from 2004 to 2008. The results showed that the 12 pathogenic strains were of the O:3 serotype. Six strains were isolated from domestic dogs (Canis familiaris) belonging to farmers and were found to be the primary carriers of pathogenic Y. enterocolitica strains, especially in Xuzhou. Pulsed-field gel electrophoresis analysis of the pathogenic strains from dogs belonging to farmers showed that they shared the same patterns as strains from diarrhea patients isolated in 1994. This indicates that the strains from domestic dogs have a close correlation with the strains causing human infections. PMID:20181899

Isolation and Characterization of Actinomycete Antagonists of a Fungal Root Pathogen †

Science.gov (United States)

Crawford, Don L.; Lynch, James M.; Whipps, John M.; Ousley, Margaret A.

1993-01-01

By use of selective media, 267 actinomycete strains were isolated from four rhizosphere-associated and four non-rhizosphere-associated British soils. Organic media with low nutrient concentrations were found to be best for isolating diverse actinomycetes while avoiding contamination and overgrowth of isolation media by eubacteria and fungi. While all isolates grew well at pHs 6.5 to 8.0, a few were unable to grow at pH 6.0 and a significant number failed to grow at pH 5.5. Eighty-two selected isolates were screened for in vitro antagonism towards Pythium ultimum by use of a Difco cornmeal agar assay procedure. Five isolates were very strong antagonists of the fungus, four were strong antagonists, and ten others were weakly antagonistic. The remaining isolates showed no antagonism by this assay. Additional studies showed that several of the P. ultimum antagonists also strongly inhibited growth of other root-pathogenic fungi. Twelve isolates showing antifungal activity in the in vitro assay were also tested for their effects on the germination and short-term growth of lettuce plants in glasshouse pot studies in the absence of pathogens. None of the actinomycetes prevented seed germination, although half of the isolates retarded seed germination and outgrowth of the plants by 1 to 3 days. During 18-day growth experiments, biomass yields of some actinomycete-inoculated plants were reduced in comparison with untreated control plants, although all plants appeared healthy and well rooted. None of the actinomycetes significantly enhanced plant growth over these short-term experiments. For some, but not all, actinomycetes, some correlations between delayed seed germination and reduced 18-day plant biomass yields were seen. For others, plant biomass yields were not reduced despite an actinomycete-associated delay in seed germination and plant outgrowth. Preliminary glasshouse experiments indicated that some of the actinomycetes protect germinating lettuce seeds against

First report of a cross-kingdom pathogenic bacterium, Achromobacter xylosoxidans isolated from stipe-rot Coprinus comatus.

Science.gov (United States)

Ye, Luona; Guo, Mengpei; Ren, Pengfei; Wang, Gangzheng; Bian, Yinbing; Xiao, Yang; Zhou, Yan

2018-03-01

Coprinus comatus is an edible mushroom widely cultivated in China as a delicious food. Various diseases have occurred on C. comatus with the cultivated area increasing. In this study, the pathogenic bacterium JTG-B1, identified as Achromobacter xylosoxidans by 16S rDNA and nrdA gene sequencing, was isolated from edible mushroom Coprinus comatus with serious rot disease on its stipe. A. xylosoxidans has been confirmed as an important opportunistic human pathogenic bacterium and has been isolated from respiratory samples from cystic fibrosis. It is widely distributed in the environment. Here, we first report that fungi can also serve as a host for A. xylosoxidans. We confirmed that it can cross-kingdom infect between animals (mice) and fungi (C. comatus). The results of pathogenicity tests, physiological, biochemical and genotyping analysis of A. xylosoxidans from different hosts suggested that different strain of A. xylosoxidans may have pathogenicity differentiation. A. xylosoxidans not only is pathogenic to C. comatus but also may threaten human health. Copyright © 2017 Elsevier GmbH. All rights reserved.

Occurrence and antibacterial susceptibility pattern of bacterial pathogens isolated from diarrheal patients in Pakistan

OpenAIRE

Rasool, Muhammad H.; Siddique, Abu B.; Saqalein, Muhammad; Asghar, Muhammad J.; Zahoor, Muhammad A.; Aslam, Bilal; Shafiq, Humerah B.; Nisar, Muhammad A.

2016-01-01

Objective: To determine the occurrence of bacterial pathogens responsible for diarrhea and to engender information regarding the effectiveness of commonly used antibiotic against diarrhea. Methods: This cross-sectional study was conducted between April and July 2014. Samples were collected from the Divisional Headquarter and Allied Hospital, Faisalabad, Pakistan. The differential and selective media were used to isolate bacterial pathogens, which were identified through cultural character...

Pathogenicity evaluation of native isolates of entomopathogenic fungí against andean weevil, Premnotrypes vorax (Hustache

Directory of Open Access Journals (Sweden)

Giselle Rivera

2001-07-01

Full Text Available The main goal of this study was pathogenicity evaluation of Beauveria bassiana and Metarhizium anisopliae native isolates, obtained from natural habitats and stocked potato, against potato andean weevil, Premnotrypes vorax (Hustache (COLEOPTERA: Curculionidae, and important potato insect pest in Colombia and other Andean countries. Patogenicity was determined by laboratory bioassays, using either reared insects or field captured insects. Insect rearing data are presented. Pathogenicity evaluation was express as mortality against time, estimating LT50 and LT90 for all the fungal isolates, and mortality against spore concentration, estimating CL50 for two selected isolates. In all cases, total mortality percentils were above 45%. Differences between reared and field captured insects were evident. According to obtained data one of the fungal isolates: B. bassiana 9770, obtained from R vorax larva (TL50: 4.7 days - 9.8 days; TL90: 14.1 days - 20.8 days; CL50:7.03 x 104spores/ml appears as a promisory fungal isolate for further studies. Out of this study, differences in the andean weevil, P. vorax, adult mortality, with regard to entomopathogenic fungal isolate and insect origin were manifest.

Microbial Inhibition of Fusarium Pathogens and Biological Modification of Trichothecenes in Cereal Grains

Directory of Open Access Journals (Sweden)

Urszula Wachowska

2017-12-01

Full Text Available Fungi of the genus Fusarium infect cereal crops during the growing season and cause head blight and other diseases. Their toxic secondary metabolites (mycotoxins contaminate grains. Several dozen toxic compounds produced by fungal pathogens have been identified to date. Type B trichothecenes—deoxynivalenol, its acetyl derivatives and nivalenol (produced mainly by F. graminearum and F. culmorum—are most commonly detected in cereal grains. “T-2 toxin” (produced by, among others, F. sporotrichioides belongs to type-A trichothecenes which are more toxic than other trichothecenes. Antagonistic bacteria and fungi can affect pathogens of the genus Fusarium via different modes of action: direct (mycoparasitism or hyperparasitism, mixed-path (antibiotic secretion, production of lytic enzymes and indirect (induction of host defense responses. Microbial modification of trichothecenes involves acetylation, deacetylation, oxidation, de-epoxidation, and epimerization, and it lowers the pathogenic potential of fungi of the genus Fusarium. Other modifing mechanisms described in the paper involve the physical adsorption of mycotoxins in bacterial cells and the conjugation of mycotoxins to glucose and other compounds in plant and fungal cells. The development of several patents supports the commercialization and wider application of microorganisms biodegrading mycotoxins in grains and, consequently, in feed additives.

Microbial Observatory (ISS-MO): Study of BSL-2 bacterial isolates from the International Space Station

Data.gov (United States)

National Aeronautics and Space Administration — In an on-going Microbial Observatory experimental investigation on the International Space Station (ISS) multiple bacterial isolates of Biosafety Level 2 (BSL-2)...

Antibiotic resistance and pathogenicity factors in Staphylococcus aureus isolated from mastitic Sahiwal cattle.

Science.gov (United States)

Kumar, Ravinder; Yadav, B R; Singh, R S

2011-03-01

Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious problem in dairy animals suffering from mastitis. In the present study, the distribution of mastitic MRSA and antibiotic resistance was studied in 107 strains of S. aureus isolated from milk samples from 195 infected udders. The characterizations pathogenic factors (adhesin and toxin genes) and antibiotic susceptibility of isolates were carried out using gene amplification and disc diffusion assays, respectively. A high prevalence of MRSA was observed in the tested isolates (13.1%). The isolates were also highly resistant to antibiotics, i.e. 36.4% were resistant to streptomycin, 33.6% to oxytetracycline, 29.9% to gentamicin and 26.2% each to chloramphenicol, pristinomycin and ciprofloxacin. A significant variation in the expression of pathogenic factors (Ig, coa and clf) was observed in these isolates. The overall distribution of adhesin genes ebp, fib, bbp, fnbB, cap5, cap8, map and cna in the isolates was found to be 69.1, 67.2, 6.5, 20.5, 60.7, 26.1, 81.3 and 8.4%, respectively. The presence of fib, fnbB, bbp and map genes was considerably greater in MRSA than in methicillin-susceptible S. aureus (MSSA) isolates. The proportions of toxin genes, namely, hlb, seb, sec, sed, seg and sei, in the isolates were found to be 94.3, 0.9, 8.4, 0.9, 10.2 and 49.5%, respectively. The proportions of agr genes I, II, III and IV were found to be 39.2, 27.1, 21.5 and 12.1%, respectively. A few isolates showed similar antibiotic-resistance patterns, which could be due to identical strains or the dissemination of the same strains among animals. These findings can be utilized in mastitis treatment programmes and antimicrobials strategies in organized herd.

Medical Devices; Immunology and Microbiology Devices; Classification of the Device To Detect and Identify Microbial Pathogen Nucleic Acids in Cerebrospinal Fluid. Final order.

Science.gov (United States)

2017-10-20

The Food and Drug Administration (FDA or we) is classifying the device to detect and identify microbial pathogen nucleic acids in cerebrospinal fluid into class II (special controls). The special controls that will apply to the device type are identified in this order and will be part of the codified language for the device to detect and identify microbial pathogen nucleic acids in cerebrospinal fluid’s classification. We are taking this action because we have determined that classifying the device into class II (special controls) will provide a reasonable assurance of safety and effectiveness of the device. We believe this action will also enhance patients' access to beneficial innovative devices, in part by reducing regulatory burdens.

Pathogenicity of Metarrhizium anisopliae (Metsch.) Sorokin and Beauveria bassiana (Bals.) Vuillemin isolates to Scaptocoris carvalhoi Becker (Hemiptera, Cydnidae); Patogenicidade de isolados de Metarhizium anisopliae (Metsch.) Sorokin e de Beauveria bassiana (Bals.) Vuillemin a Scaptocoris carvalhoi Becker (Hemiptera, Cydnidae)

Energy Technology Data Exchange (ETDEWEB)

Xavier, Luciane Modenez Saldivar [Universidade Federal da Grande Dourados (UFGD), Dourados, MS (Brazil)], e-mail: luciane_modenez@ibest.com.br; Avila, Crebio Jose [EMBRAPA Agropecuaria Oeste, Dourados, MS (Brazil)], e-mail: crebio@cpao.embrapa.br

2006-12-15

Pathogenicity of the fungi Metarrhizium anisopliae (Metsch.) Sorokin and Beauveria bassiana (Bals.) Vuillemin to stink bug Scaptocoris carvalhoi Becker, 1967 was evaluated under laboratory and greenhouse conditions. Experiments were carried out at EMBRAPA Agropecuaria Oeste, Dourados, Mato Grosso do Sul State, Brazil, in 2003. Ten M. anisopliae and eleven B. bassiana isolates were evaluated in laboratory using a completely randomized experimental design with five replicates (10 adults and 5 nymphs/plot). The pathogenicity of M. anisopliae isolate (Ma69) was also separately evaluated against nymphs and adults in laboratory and greenhouse. The stink bug mortality levels were higher for M. anisopliae isolates (between 73.3% and 94.7% than for B. bassiana isolates (between 10.7% and 78.7%). In greenhouse, stink bug mortality due to the M. anisopliae isolate (Ma69) was 57.3%, and there was no difference of mortality for nymphs and adults of stink bug in laboratory. However, in greenhouse, mortality levels were significantly higher (p<0,05) for nymphs (38,4%) than for adults (16,2%). From these data, we conclude that M. anisopliae isolate Ma69 was efficient to control S. carvalhoi in laboratory and in greenhouse, thus being a promising choice for use as a microbial insecticide under field conditions. (author)

Transmutation of Personal Glucose Meters into Portable and Highly Sensitive Microbial Pathogen Detection Platform.

Science.gov (United States)

Wang, Zhenzhen; Chen, Zhaowei; Gao, Nan; Ren, Jinsong; Qu, Xiaogang

2015-10-07

Herein, for the first time, we presented a simple and general approach by using personal glucose meters (PGM) for portable and ultrasensitive detection of microbial pathogens. Upon addition of pathogenic bacteria, glucoamylase-quaternized magnetic nanoparticles (GA-QMNPS) conjugates were disrupted by the competitive multivalent interactions between bacteria and QMNPS, resulting in the release of GA. After magnetic separation, the free GA could catalyze the hydrolysis of amylose into glucose for quantitative readout by PGM. In such way, PGM was transmuted into a bacterial detection device and extremely low detection limits down to 20 cells mL(-1) was achieved. More importantly, QMNPS could inhibit the growth of the bacteria and destroy its cellular structure, which enabled bacteria detection and inhibition simultaneously. The simplicity, portability, sensitivity and low cost of presented work make it attractive for clinical applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Molecular diagnostics for the detection and characterization of microbial pathogens.

Science.gov (United States)

Procop, Gary W

2007-09-01

New and advanced methods of molecular diagnostics are changing the way we practice clinical microbiology, which affects the practice of medicine. Signal amplification and real-time nucleic acid amplification technologies offer a sensitive and specific result with a more rapid turnaround time than has ever before been possible. Numerous methods of postamplification analysis afford the simultaneous detection and differentiation of numerous microbial pathogens, their mechanisms of resistance, and the construction of disease-specific assays. The technical feasibility of these assays has already been demonstrated. How these new, often more expensive tests will be incorporated into routine practice and the impact they will have on patient care remain to be determined. One of the most attractive uses for such techniques is to achieve a more rapid characterization of the infectious agent so that a narrower-spectrum antimicrobial agent may be used, which should have an impact on resistance patterns.

Synergistic antibacterial action of β-sitosterol-D-glucopyranoside isolated from Desmostachya bipinnata leaves with antibiotics against common human pathogens

Directory of Open Access Journals (Sweden)

Shankar Subramaniam

Full Text Available Desmostachya bipinnata (L. Stapf, Poaceae, or Kusha in Sanskrit, is a sacred grass used extensively in Indian Vedic practices. It is well known for its medicinal value and is used in traditional Indian medicine to treat microbial infection in combination with other herbs. An effort has been made to isolate and characterize the bioactive compounds from the hydroalcoholic extract of D. bipinnata through bioassay guided fractionation, column chromatography. Their individual or combined antimicrobial properties were determined by the Resazurin Microtitre Assay, the checkerboard assay in combination with antibiotics, and by time kill curve analysis. β-Sitosterol-D-glucopyranoside was the bioactive compound identified to have the best antimicrobial activity (MIC 6-50 µg/ml and it works synergistically with most antibiotics, especially with ciprofloxacin. Time kill curves showed that BS kills most of the pathogens within 5-10 h. To our knowledge at its best, this is the first time report of antibacterial synergy of β-sitosterol-D-glucopyranoside from D. bipinnata.

Microbial Pathogens Implicated in Reproductive Health Infections in a Special Treatment Clinic in Ibadan, Nigeria

Directory of Open Access Journals (Sweden)

Adenike Ogunshe

2009-03-01

Full Text Available Objective: The lack of adequate recognition of health importance of non-HIV reproductive health infections (RHIs in Nigeria has led into this study, which was to determine clinical pathogens in non-HIV RHI in Nigeria using a tertiary health facility as case study.Materials and Methods: A nine-year investigation was carried out between 1997 and 2005 on 4047 (n = 1626 males; n = 2421 females patients presenting at Special Treatment Clinic (STC of University College Hospital (UCH Ibadan, Nigeria. Routine laboratory procedures using appropriate culture media, culture conditions, and current phenotypic taxonomic tools for classification of isolated pathogens were employed.Results: Age (p = 0.019 and gender (p<0.0001 were related to the recovery rates of pathogens Candida species (55.6 %, Neisseria gonorrhoae (11.1%, Gardenella vaginalis (10.3%, Escherichia coli (9.2 %, Klebsiella sp. (4.2%, streptococci (4.0%, Staphylococcus aureus (2.3%, Proteus sp., (1.8%, Haemophilus ducreyi (0.5%, Trichomonas vaginalis (0.44% and Pseudomonas aeruginosa (0.18%. Candida and Gardenella vaginalis species were mostly recovered from female patients, while N.gonorrhoeae were mostly isolated from male patients. Age brackets for the recovery of pathogens were Neisseria gonorrhoeae (16-30 years; Gardenella vaginalis (21-25 and 31-35 years and C.albicans (21-30 years.Conclusion: Candida, Neisseria gonorrhoea and Gadrenella vaginalis were the most recovered pathogens from patients presenting at Special Treatment Clinic of a tertiary health institution in Nigeria, and the relationship between age, gender and the aetiological agents was statistically significant.

Prevalence and Antimicrobial Susceptibility of Vibrio parahaemolyticus Isolated from Short Mackerels (Rastrelliger brachysoma) in Malaysia.

Science.gov (United States)

Tan, Chia W; Malcolm, Tan T H; Kuan, Chee H; Thung, Tze Y; Chang, Wei S; Loo, Yuet Y; Premarathne, Jayasekara M K J K; Ramzi, Othman B; Norshafawatie, Mohd F S; Yusralimuna, Nordin; Rukayadi, Yaya; Nakaguchi, Yoshitsugu; Nishibuchi, Mitsuaki; Radu, Son

2017-01-01

Numerous prevalence studies and outbreaks of Vibrio parahaemolyticus infection have been extensively reported in shellfish and crustaceans. Information on the quantitative detection of V. parahaemolyticus in finfish species is limited. In this study, short mackerels ( Rastrelliger brachysoma ) obtained from different retail marketplaces were monitored with the presence of total and pathogenic strains of V. parahaemolyticus . Out of 130 short mackerel samples, 116 (89.2%) were detected with the presence of total V. parahaemolyticus and microbial loads of total V. parahaemolyticus ranging from 10 5 MPN/g. Prevalence of total V. parahaemolyticus was found highest in wet markets (95.2%) followed by minimarkets (89.1%) and hypermarkets (83.3%). Pathogenic V. parahaemolyticus strains ( tdh + and/or trh +) were detected in 16.2% (21 of 130) of short mackerel samples. The density of tdh + V. parahaemolyticus strains were examined ranging from 3.6 to >10 5 MPN/g and microbial loads of V. parahaemolyticus strains positive for both tdh and trh were found ranging from 300 to 740 MPN/g. On the other hand, antibiotic susceptibility profiles of V. parahaemolyticus strains isolated from short mackerels were determined through disc diffusion method in this study. Assessment of antimicrobial susceptibility profile of V. parahaemolyticus revealed majority of the isolates were highly susceptible to ampicillin sulbactam, meropenem, ceftazidime, and imipenem, but resistant to penicillin G and ampicillin. Two isolates (2.99%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.41 which shown resistance to 7 antibiotics. Results of the present study demonstrated that the occurrence of pathogenic V. parahaemolyticus strains in short mackerels and multidrug resistance of V. parahaemolyticus isolates could be a potential public health concerns to the consumer. Furthermore, prevalence data attained from the current study can be further used to develop a microbial risk

Prevalence and Antimicrobial Susceptibility of Vibrio parahaemolyticus Isolated from Short Mackerels (Rastrelliger brachysoma in Malaysia

Directory of Open Access Journals (Sweden)

Chia W. Tan

2017-06-01

Full Text Available Numerous prevalence studies and outbreaks of Vibrio parahaemolyticus infection have been extensively reported in shellfish and crustaceans. Information on the quantitative detection of V. parahaemolyticus in finfish species is limited. In this study, short mackerels (Rastrelliger brachysoma obtained from different retail marketplaces were monitored with the presence of total and pathogenic strains of V. parahaemolyticus. Out of 130 short mackerel samples, 116 (89.2% were detected with the presence of total V. parahaemolyticus and microbial loads of total V. parahaemolyticus ranging from <3 to >105 MPN/g. Prevalence of total V. parahaemolyticus was found highest in wet markets (95.2% followed by minimarkets (89.1% and hypermarkets (83.3%. Pathogenic V. parahaemolyticus strains (tdh+ and/or trh+ were detected in 16.2% (21 of 130 of short mackerel samples. The density of tdh+ V. parahaemolyticus strains were examined ranging from 3.6 to >105 MPN/g and microbial loads of V. parahaemolyticus strains positive for both tdh and trh were found ranging from 300 to 740 MPN/g. On the other hand, antibiotic susceptibility profiles of V. parahaemolyticus strains isolated from short mackerels were determined through disc diffusion method in this study. Assessment of antimicrobial susceptibility profile of V. parahaemolyticus revealed majority of the isolates were highly susceptible to ampicillin sulbactam, meropenem, ceftazidime, and imipenem, but resistant to penicillin G and ampicillin. Two isolates (2.99% exhibited the highest multiple antibiotic resistance (MAR index value of 0.41 which shown resistance to 7 antibiotics. Results of the present study demonstrated that the occurrence of pathogenic V. parahaemolyticus strains in short mackerels and multidrug resistance of V. parahaemolyticus isolates could be a potential public health concerns to the consumer. Furthermore, prevalence data attained from the current study can be further used to develop a

Prevalence and Antimicrobial Susceptibility of Vibrio parahaemolyticus Isolated from Short Mackerels (Rastrelliger brachysoma) in Malaysia

Science.gov (United States)

Tan, Chia W.; Malcolm, Tan T. H.; Kuan, Chee H.; Thung, Tze Y.; Chang, Wei S.; Loo, Yuet Y.; Premarathne, Jayasekara M. K. J. K.; Ramzi, Othman B.; Norshafawatie, Mohd F. S.; Yusralimuna, Nordin; Rukayadi, Yaya; Nakaguchi, Yoshitsugu; Nishibuchi, Mitsuaki; Radu, Son

2017-01-01

Numerous prevalence studies and outbreaks of Vibrio parahaemolyticus infection have been extensively reported in shellfish and crustaceans. Information on the quantitative detection of V. parahaemolyticus in finfish species is limited. In this study, short mackerels (Rastrelliger brachysoma) obtained from different retail marketplaces were monitored with the presence of total and pathogenic strains of V. parahaemolyticus. Out of 130 short mackerel samples, 116 (89.2%) were detected with the presence of total V. parahaemolyticus and microbial loads of total V. parahaemolyticus ranging from 105 MPN/g. Prevalence of total V. parahaemolyticus was found highest in wet markets (95.2%) followed by minimarkets (89.1%) and hypermarkets (83.3%). Pathogenic V. parahaemolyticus strains (tdh+ and/or trh+) were detected in 16.2% (21 of 130) of short mackerel samples. The density of tdh+ V. parahaemolyticus strains were examined ranging from 3.6 to >105 MPN/g and microbial loads of V. parahaemolyticus strains positive for both tdh and trh were found ranging from 300 to 740 MPN/g. On the other hand, antibiotic susceptibility profiles of V. parahaemolyticus strains isolated from short mackerels were determined through disc diffusion method in this study. Assessment of antimicrobial susceptibility profile of V. parahaemolyticus revealed majority of the isolates were highly susceptible to ampicillin sulbactam, meropenem, ceftazidime, and imipenem, but resistant to penicillin G and ampicillin. Two isolates (2.99%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.41 which shown resistance to 7 antibiotics. Results of the present study demonstrated that the occurrence of pathogenic V. parahaemolyticus strains in short mackerels and multidrug resistance of V. parahaemolyticus isolates could be a potential public health concerns to the consumer. Furthermore, prevalence data attained from the current study can be further used to develop a microbial risk

ANTIMICROBIAL SUSCEPTIBILITY PROFILE OF MICROBIAL PATHOGENS ISOLATED FROM CALVES WITH RESPIRATORY DISEASES

Directory of Open Access Journals (Sweden)

George Cosmin Nadas

2016-11-01

Full Text Available Introduction: Respiratory disease in calves is an actual problem, a major cause of economic losses due to mortality, growth delay and improper development. These conditions are frequent in calves due to the weaning stress, transport and environmental changes. Aims: The aim of this study was the isolation of bacteria from 30 calves with respiratory disorders and their antibiotic susceptibility testing. Materials and methods: Samples were collected from calves with respiratory disorders (nasal discharge aged 6 to 9 weeks in 2 series, using sterile swabs. Samples were initially inoculated on blood agar and MacConkey agar following the characteristics of the colonies and microscopic examination that enabled the identification of bacterial species. Isolated strains were used to flood Mueller-Hinton agar to carry out sensitivity testing. The antibiotics tested were represented by: Amoxicillin with clavulanic acid, Gentamicin, Florfenicol, Enrofloxacin, Marbofloxacin, Penicillin G, Cefquinone, Tulathromycin, Ceftiofur, Tylosin and Cephalotin. Results: Genus Streptococcus have been identified in 23 samples, followed by Staphylococcus identified in 14 samples, and Bacillus spp., in 10 nasal swabs; The most common bacteria associations were represented by Streptococcus-Staphylococcus, Streptococcus-Staphylococcus-Bacillus, and Streptococcus-E.coli. The most efficient antibiotic was Cefquinome (Cobactan, followed by Penicillin G and Amoxicillin with clavulanic acid (Amoxiclav; the least effective antibiotics were Florfenicol and Tulathromycin. Conclusions: The study carried out on nasal discharge samples collected from calves with respiratory disorders and their antimicrobial profile testing led to the following conclusions: 1 Low susceptibility to Florfenicol is caused by previous treatments when this molecule was excessively used and without prior sensitivity testing. 2 Cefquinome may represent an emergency therapeutic antibiotic for respiratory

Microbial Assessment and Prevalence of Foodborne Pathogens in Natural Cheeses in Japan

Directory of Open Access Journals (Sweden)

Firew Kassa Esho

2013-01-01

Full Text Available The production and consumption of domestic natural cheese in Japan is increasing year by year. More than ninety percent of domestic natural cheese is produced in Hokkaido region of Japan, while information on its quality and safety related to foodborne pathogens is limited. To assess the microbiological safety of domestic natural cheese, a total of 126 natural cheese samples produced in Hokkaido were collected from December, 2012, to July, 2013. In addition to standard plate count (SPC and coliform counts, the prevalence study of three pathogens (Listeria monocytogenes, pathogenic Escherichia coli, and Salmonella spp. was performed on each sample. Real-time PCR and matrix-assisted laser desorption-ionization time-of-flight mass spectrometer methods were employed for identification of presumptive pathogens. Coliform was detected in 25 samples (19.8% with a minimum of 25 cfu/g and a maximum of more than 3.0 × 106 cfu/g. Salmonella spp. and L. monocytogenes were not isolated from any of the samples. Only one sample (0.80% showed positive PCR amplification for ipaH gene suggesting possible contamination of enteroinvasive E. coli or Shigella in this product. Overall results indicate that natural cheeses produced in Hokkaido region were satisfactory microbiological quality according to existing international standards.

Microbial Gas Generation Under Expected Waste Isolation Pilot Plant Repository Conditions: Final Report

International Nuclear Information System (INIS)

Gillow, J.B.; Francis, A.

2011-01-01

Gas generation from the microbial degradation of the organic constituents of transuranic (TRU) waste under conditions expected in the Waste Isolation Pilot Plant (WIPP) was investigated. The biodegradation of mixed cellulosic materials and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, hypalon, leaded hypalon, and neoprene) was examined. We evaluated the effects of environmental variables such as initial atmosphere (air or nitrogen), water content (humid (∼70% relative humidity, RH) and brine inundated), and nutrient amendments (nitogen phosphate, yeast extract, and excess nitrate) on microbial gas generation. Total gas production was determined by pressure measurement and carbon dioxide (CO 2 ) and methane (CH 4 ) were analyzed by gas chromatography; cellulose degradation products in solution were analyzed by high-performance liquid chromatography. Microbial populations in the samples were determined by direct microscopy and molecular analysis. The results of this work are summarized.

TLR-dependent human mucosal epithelial cell responses to microbial pathogens.

Directory of Open Access Journals (Sweden)

Paola eMassari

2014-08-01

Full Text Available AbstractToll-Like Receptor (TLR signaling represents one of the best studied pathways to implement defense mechanisms against invading microbes in humans as well as in animals. TLRs respond to specific microbial ligands and to danger signals produced by the host during infection, and initiate downstream cascades that activate both innate and adaptive immunity. TLRs are expressed by professional immune cells and by the large majority of non-hematopoietic cells, including epithelial cells. In epithelial tissues, TLR functions are particularly important because these sites are constantly exposed to microorganisms, due to their location at the host interface with the environment. While at these sites, specific defense mechanisms and inflammatory responses are initiated via TLR signaling against pathogens, suppression or lack of TLR activation is also observed in response to the commensal microbiota. The mechanisms by which TLR signaling is regulated in mucosal epithelial cells include differential expression and levels of TLRs (and their signaling partners, their cellular localization and positioning within the tissue in a fashion that favors responses to pathogens while dampening responses to commensals and maintaining tissue homeostasis in physiologic conditions. In this review, the expression and activation of TLRs in mucosal epithelial cells of several sites of the human body are examined. Specifically, the oral cavity, the ear canal and eye, the airways, the gut and the reproductive tract are discussed, along with how site-specific host defense mechanisms are implemented via TLR signaling.

No evidence of enemy release in pathogen and microbial communities of common wasps (Vespula vulgaris in their native and introduced range.

Directory of Open Access Journals (Sweden)

Philip J Lester

Full Text Available When invasive species move to new environments they typically experience population bottlenecks that limit the probability that pathogens and parasites are also moved. The invasive species may thus be released from biotic interactions that can be a major source of density-dependent mortality, referred to as enemy release. We examined for evidence of enemy release in populations of the common wasp (Vespula vulgaris, which attains high densities and represents a major threat to biodiversity in its invaded range. Mass spectrometry proteomic methods were used to compare the microbial communities in wasp populations in the native (Belgium and England and invaded range (Argentina and New Zealand. We found no evidence of enemy release, as the number of microbial taxa was similar in both the introduced and native range. However, some evidence of distinctiveness in the microbial communities was observed between countries. The pathogens observed were similar to a variety of taxa observed in honey bees. These taxa included Nosema, Paenibacillus, and Yersina spp. Genomic methods confirmed a diversity of Nosema spp., Actinobacteria, and the Deformed wing and Kashmir bee viruses. We also analysed published records of bacteria, viruses, nematodes and fungi from both V. vulgaris and the related invader V. germanica. Thirty-three different microorganism taxa have been associated with wasps including Kashmir bee virus and entomophagous fungi such as Aspergillus flavus. There was no evidence that the presence or absence of these microorganisms was dependent on region of wasp samples (i.e. their native or invaded range. Given the similarity of the wasp pathogen fauna to that from honey bees, the lack of enemy release in wasp populations is probably related to spill-over or spill-back from bees and other social insects. Social insects appear to form a reservoir of generalist parasites and pathogens, which makes the management of wasp and bee disease difficult.

No evidence of enemy release in pathogen and microbial communities of common wasps (Vespula vulgaris) in their native and introduced range.

Science.gov (United States)

Lester, Philip J; Bosch, Peter J; Gruber, Monica A M; Kapp, Eugene A; Peng, Lifeng; Brenton-Rule, Evan C; Buchanan, Joe; Stanislawek, Wlodek L; Archer, Michael; Corley, Juan C; Masciocchi, Maitè; Van Oystaeyen, Annette; Wenseleers, Tom

2015-01-01

When invasive species move to new environments they typically experience population bottlenecks that limit the probability that pathogens and parasites are also moved. The invasive species may thus be released from biotic interactions that can be a major source of density-dependent mortality, referred to as enemy release. We examined for evidence of enemy release in populations of the common wasp (Vespula vulgaris), which attains high densities and represents a major threat to biodiversity in its invaded range. Mass spectrometry proteomic methods were used to compare the microbial communities in wasp populations in the native (Belgium and England) and invaded range (Argentina and New Zealand). We found no evidence of enemy release, as the number of microbial taxa was similar in both the introduced and native range. However, some evidence of distinctiveness in the microbial communities was observed between countries. The pathogens observed were similar to a variety of taxa observed in honey bees. These taxa included Nosema, Paenibacillus, and Yersina spp. Genomic methods confirmed a diversity of Nosema spp., Actinobacteria, and the Deformed wing and Kashmir bee viruses. We also analysed published records of bacteria, viruses, nematodes and fungi from both V. vulgaris and the related invader V. germanica. Thirty-three different microorganism taxa have been associated with wasps including Kashmir bee virus and entomophagous fungi such as Aspergillus flavus. There was no evidence that the presence or absence of these microorganisms was dependent on region of wasp samples (i.e. their native or invaded range). Given the similarity of the wasp pathogen fauna to that from honey bees, the lack of enemy release in wasp populations is probably related to spill-over or spill-back from bees and other social insects. Social insects appear to form a reservoir of generalist parasites and pathogens, which makes the management of wasp and bee disease difficult.

Evaluation of Pathogen Removal in a Solar Sludge Drying Facility Using Microbial Indicators

Directory of Open Access Journals (Sweden)

D. İpek Kurtböke

2010-02-01

Full Text Available South East Queensland is one of the fastest growing regions in Australia with a correspondingly rapid increase in sewage production. In response, local councils are investing in more effective and sustainable options for the treatment and reuse of domestic and industrial effluents. A novel, evaporative solar dryer system has been installed on the Sunshine Coast to convert sewage sludge into a drier, usable form of biosolids through solar radiation exposure resulting in decreased moisture concentration and pathogen reduction. Solar-dried biosolids were analyzed for selected pathogenic microbial, metal and organic contaminants at the end of different drying cycles in a collaborative study conducted with the Regional Council. Although fecal coliforms were found to be present, enteroviruses, parasites, E. coli, and Salmonella sp. were not detected in the final product. However, elevated levels of zinc and copper were still present which restricted public use of the biosolids. Dilution of the dried biosolids with green waste as well as composting of the biosolids is likely to lead to the production of an environmentally safe, Class A end-product.

Pathogenicity and molecular analysis of an infectious bursal disease virus isolated from Malaysian village chickens.

Science.gov (United States)

Tan, D Y; Hair-Bejo, M; Omar, A R; Aini, I

2004-01-01

The characteristics of the pathogenic infectious bursal disease virus (IBDV) that infected avian species other than commercial chickens were largely unknown. In this study, by using in vivo and molecular methods, we had characterized an IBDV isolate (named 94268) isolated from an infectious bursal disease (IBD) outbreak in Malaysian village chickens--the adulterated descendant of the Southeast Asian jungle fowl (Gallus bankiva) that were commonly reared in the backyard. The 94268 isolate was grouped as the very virulent IBDV (vvIBDV) strain because it caused severe lesions and a high mortality rate in village chickens (>88%) and experimentally infected specific-pathogen-free chickens (>66%). In addition, it possessed all of the vvIBDV molecular markers in its VP2 gene. Phylogenetic analysis using distance, maximum parsimony, and maximum likelihood methods revealed that 94268 was monophyletic with other vvIBDV isolates and closely related to the Malaysian vvIBDV isolates. Given that the VP2 gene of 94268 isolate was almost identical and evolutionarily closely related to other field IBDV isolates that affected the commercial chickens, we therefore concluded that IBD infections had spread across the farm boundary. IBD infection in the village chicken may represent an important part of the IBD epidemiology because these birds could harbor the vvIBDV strain and should not be overlooked in the control and prevention of the disease.

Genetic and Pathogenic Variability of Fusarium oxysporum f. sp. cepae Isolated from Onion and Welsh Onion in Japan.

Science.gov (United States)

Sasaki, Kazunori; Nakahara, Katsuya; Tanaka, Shuhei; Shigyo, Masayoshi; Ito, Shin-ichi

2015-04-01

Fusarium oxysporum f. sp. cepae causes Fusarium basal rot in onion (common onion) and Fusarium wilt in Welsh onion. Although these diseases have been detected in various areas in Japan, knowledge about the genetic and pathogenic variability of F. oxysporum f. sp. cepae is very limited. In this study, F. oxysporum f. sp. cepae was isolated from onion and Welsh onion grown in 12 locations in Japan, and a total of 55 F. oxysporum f. sp. cepae isolates (27 from onion and 28 from Welsh onion) were characterized based on their rDNA intergenic spacer (IGS) and translation elongation factor-1α (EF-1α) nucleotide sequences, vegetative compatibility groups (VCGs), and the presence of the SIX (secreted in xylem) homologs. Phylogenetic analysis of IGS sequences showed that these isolates were grouped into eight clades (A to H), and 20 onion isolates belonging to clade H were monophyletic and assigned to the same VCG. All the IGS-clade H isolates possessed homologs of SIX3, SIX5, and SIX7. The SIX3 homolog was located on a 4 Mb-sized chromosome in the IGS-clade H isolates. Pathogenicity tests using onion seedlings showed that all the isolates with high virulence were in the IGS-clade H. These results suggest that F. oxysporum f. sp. cepae isolates belonging to the IGS-clade H are genetically and pathogenically different from those belonging to the other IGS clades.

High pathogenicity and strong immunogenicity of a Chinese isolate of Eimeria magna Pérard, 1925.

Science.gov (United States)

Tao, Geru; Wang, Yunzhou; Li, Chao; Gu, Xiaolong; Cui, Ping; Fang, Sufang; Suo, Xun; Liu, Xianyong

2017-06-01

Coccidia infection of rabbits with one or several species of parasites of the genus Eimeria causes coccidiosis, a disease leading to huge economic losses in the rabbit industry. Eimeria magna, one of the causal agents of rabbit coccidiosis, was characterized as mildly pathogenic and moderately immunogenic in previous studies. In this study, we identified a Chinese isolate of E. magna by testing its biological features (oocyst morphology and size, prepatent time) and sequencing its internal transcribed spacer 1 (ITS-1) DNA fragment. This isolate is highly pathogenic; infection of rabbits with only 1×10 2 oocysts caused a 55% reduction in weight gain in 14days. In addition, immunization with 1×10 2 oocysts prevented body weight loss against re-infection with 5×10 4 oocysts, indicating the high immunogenicity of this isolate. Our study described the distinctive phenotype of the Chinese isolate of E. magna and contributed to the research of geographic variation of rabbit coccidia. Copyright © 2017 Elsevier B.V. All rights reserved.

Microbial safety of foods

International Nuclear Information System (INIS)

Bandekar, J.R.

2013-01-01

Despite advances in hygiene, consumer knowledge and food treatment and processing, food-borne diseases have become one of the most widespread public health problems in the world to-day. About two thirds of all outbreaks are traced to microbial contaminated food - one of the most hazardous being Clostridium botulinum, E. coli 0157: H7 and Salmonella. The pathogens can be introduced in the food products anywhere in the food chain and hence it is of prime important to have microbial vigilance in the entire food chain. WHO estimates that food-borne and water-borne diarrhoeal diseases taken together kill about 2.2 million people annually. The infants, children, elderly and immune-compromised people are particularly susceptible to food-borne diseases. Unsafe food causes many acute and life-long diseases, ranging from diarrhoeal diseases to various forms of cancer. A number of factors such as emergence of new food-borne pathogens, development of drug resistance in the pathogens, changing life style, global trade of food etc. are responsible for the continued persistence of food-borne diseases. Due to consumer demand, a number of Ready-To-Eat (RTE) minimally processed foods are increasingly marketed. However, there is increased risk of food-borne diseases with these products. The food-borne disease outbreaks due to E. coli O157:H7, Listeria monocytogenes, Salmonella and Campylobacter are responsible for recall of many foods resulting in heavy losses to food industry. The development of multi drug resistant pathogens due to indiscriminate use of antibiotics is also a major problem. Food Technology Division of Bhabha Atomic Research Centre has been working on food-borne bacterial pathogens particularly Salmonella, Campylobacter, Vibrio and Aeromonas species, their prevalence in export quality seafood as well in foods sold in retail market such as poultry, fish, sprouts and salads. These pathogens from Indian foods have been characterized for the presence of virulence genes

Antimicrobial resistance of Aeromonas hydrophila isolated from different food sources: A mini-review

Directory of Open Access Journals (Sweden)

Deyan Stratev

2016-09-01

Full Text Available Summary: Aeromonas hydrophila is a Gram-negative, oxidase-positive, facultative, anaerobic, opportunistic aquatic pathogen. A. hydrophila produces virulence factors, such as hemolysins, aerolysins, adhesins, enterotoxins, phospholipase and lipase. In addition to isolation from aquatic sources, A. hydrophila has been isolated from meat and meat products, milk and dairy products, and vegetables. However, various studies showed that this opportunistic pathogen is resistant to commercial antibiotics. This is attributed to factors such as the indiscriminate use of antibiotics in aquaculture, plasmids or horizontal gene transfer. In this report, we highlight the occurrence, prevalence and antimicrobial resistance of A. hydrophila isolated from different food samples. The presence of antimicrobial-resistant A. hydrophila in food poses threats to public and aquatic animal health. Keywords: A. hydrophila, Antimicrobial resistance, Microbial food safety

Antibacterial effect of Allium sativum cloves and Zingiber officinale rhizomes against multiple-drug resistant clinical pathogens.

Science.gov (United States)

Karuppiah, Ponmurugan; Rajaram, Shyamkumar

2012-08-01

To evaluate the antibacterial properties of Allium sativum (garlic) cloves and Zingiber officinale (ginger) rhizomes against multi-drug resistant clinical pathogens causing nosocomial infection. The cloves of garlic and rhizomes of ginger were extracted with 95% (v/v) ethanol. The ethanolic extracts were subjected to antibacterial sensitivity test against clinical pathogens. Anti-bacterial potentials of the extracts of two crude garlic cloves and ginger rhizomes were tested against five gram negative and two gram positive multi-drug resistant bacteria isolates. All the bacterial isolates were susceptible to crude extracts of both plants extracts. Except Enterobacter sp. and Klebsiella sp., all other isolates were susceptible when subjected to ethanolic extracts of garlic and ginger. The highest inhibition zone was observed with garlic (19.45 mm) against Pseudomonas aeruginosa (P. aeruginosa). The minimal inhibitory concentration was as low as 67.00 µg/mL against P. aeruginosa. Natural spices of garlic and ginger possess effective anti-bacterial activity against multi-drug clinical pathogens and can be used for prevention of drug resistant microbial diseases and further evaluation is necessary.

Pathogenic ability and saline stress tolerance of two Fusarium isolates from Odontesthes bonariensis eggs.

Science.gov (United States)

Pacheco Marino, Suani G; Cabello, Marta N; Dinolfo, María I; Stenglein, Sebastián A; Saparrat, Mario C N; Salibián, Alfredo

2016-01-01

Several fungal species represent a potential risk to embryos of Odontesthes bonariensis (Cuvier and Valenciennes, 1835), a euryhaline freshwater fish that lives in the Pampean inland waters and has potential economic relevance. To identify two fungi isolated from O. bonariensis eggs exposed to saline conditions and to characterize their pathogenicity and tolerance to sodium chloride solutions. The isolates were identified by morphological features, and a preliminar phylogenetic analysis using sequences of translation elongation factor 1-alpha (EF-1α) and calmodulin (CAM) was performed. Koch's postulates were tested to identify the causative agent of fungal infection. The influence of NaCl on the fungal growth was evaluated in in vitro assays. The isolates LPSC 1001 and 1002 were identified as representatives of the genus Fusarium, and belonging to the Fusarium incarnatum-Fusarium equiseti species complex (FIESC) and the Fusarium solani species complex (FSSC), respectively. Histological observations on eggs exposed in vitro to both isolates in infectivity assays confirmed the ability of the fungal isolates to penetrate to egg's chorionic membrane, leading to the death of embryos. Increasing NaCl concentration in the culture medium reduced the growth of the isolates LPSC 1001 and 1002, being completely inhibited at 160 and 120g/l NaCl respectively. The isolates LPSC 1001 (FIESC) and 1002 (FSSC) were identified as fungal pathogens to O. bonariensis eggs. The use of NaCl solutions as antifungal treatment was not effective to control the infection with these strains. Copyright © 2014 Asociación Española de Micología. Published by Elsevier Espana. All rights reserved.

Host-pathogen interactions in bovine mammary epithelial cells and HeLa cells by Staphylococcus aureus isolated from subclinical bovine mastitis.

Science.gov (United States)

Castilho, Ivana G; Dantas, Stéfani Thais Alves; Langoni, Hélio; Araújo, João P; Fernandes, Ary; Alvarenga, Fernanda C L; Maia, Leandro; Cagnini, Didier Q; Rall, Vera L M

2017-08-01

Staphylococcus aureus is a common pathogen that causes subclinical bovine mastitis due to several virulence factors. In this study, we analyzed S. aureus isolates collected from the milk of cows with subclinical mastitis that had 8 possible combinations of bap, icaA, and icaD genes, to determine their capacity to produce biofilm on biotic (bovine primary mammary epithelial cells and HeLa cells) and abiotic (polystyrene microplates) surfaces, and their ability to adhere to and invade these cells. We also characterized isolates for microbial surface components recognizing adhesive matrix molecules (MSCRAMM) and agr genes, and for their susceptibility to cefquinome sulfate in the presence of biofilm. All isolates adhered to and invaded both cell types, but invasion indexes were higher in bovine primary mammary epithelial cells. Using tryptic soy broth + 1% glucose on abiotic surfaces, 5 out of 8 isolates were biofilm producers, but only the bap + icaA + icaD + isolate was positive in Dulbecco's Modified Eagle's medium. The production of biofilm on biotic surfaces occurred only with this isolate and only on HeLa cells, because the invasion index for bovine primary mammary epithelial cells was too high, making it impossible to use these cells in this assay. Of the 5 biofilm producers in tryptic soy broth + 1% glucose, 4 presented with the bap/fnbA/clfA/clfB/eno/fib/ebpS combination, and all were protected from cefquinome sulfate. We found no predominance of any agr group. The high invasive potential of S. aureus made it impossible to observe biofilm in bovine primary mammary epithelial cells, and we concluded that cells with lower invasion rates, such as HeLa cells, were more appropriate for this assay. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Isolation of microbial native Stumps with cellulolytic activity of a compost process

International Nuclear Information System (INIS)

Jaramillo G, Marisol; Ruiz V Orlando Simon; Yepes P, Maria del Socorro; Montoya C, Olga Ines

2003-01-01

The isolation, selection adaptation and handling of native microorganisms coming from organic waste are an alternative to avoid the accumulation and the lack of the proper use of these undesirable materials. This organic waste is a source for obtaining microbial strains, which are potentially producers of Industrial enzymes and, at the same time, it works as substrate so that these organisms can transform it into compost or organic manure. In this work, 39 native strains of microorganisms with potential cellulolytic activity coming from the organic waste of the urban and rural sector, from the Compost Plant of Marinilla Antioquia) municipality, were isolated, evaluated and purified. The waste was previously selected and then submitted to an aerobic degradation or compost. The microbial strains were isolated in a selective medium with carboxymethyl cellulose (CMC), of the phases mesophile, termophile, cooling and maturation of the compost process. Eighty-two percent (82%)of the obtained colonies were identified, in principle as Bacillus, because of their morphology and their reaction to the Gram coloration. The fungi population was seen only during the cooling phase. Then, the potential cellulolytic activity was evaluated qualitatively in a solid medium with the Congo Red coloration, with which the Beta-endoglucanase activity was evaluated through the formation of clarified zones. Such staining was applied in two mediums with CMC with and without glucose It was observed that 33.3% of the isolated organisms produced the enzyme In both mediums; however, 25.6% of microorganisms did not show the production of this enzyme, and only 15.8% did not require the inducers to produce it

Isolation, screening and identification of novel isolates of Actinomycetes from India for antimicrobial applications

Directory of Open Access Journals (Sweden)

Vineeta Singh

2016-12-01

Full Text Available The search for novel bioactive compounds from the natural environment has been rapidly increased with the increase in multi-drug resistant (MDR pathogens. In the present study, the antimicrobial potential of novel actinomycetes has been evaluated by initial screening of six soil samples. Primary and secondary screening was performed against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Candida albicans, Candida tropicalis, Trichophyton rubrum, and other MDR bacterial and fungal test strains, and at the end thirteen active isolates were selected for further study. Microbial strains were identified on the basis of growth conditions and other biochemical characters. Five most active microbial strains were identified using 16S rRNA sequence homology and designated as Streptomyces xanthophaeus MTCC 11938, Streptomyces variabilis MTCC 12266, Streptomyces xanthochromogenes MTCC 11937, Streptomyces levis EU 124569 and Streptomyces sp. NCIM 5500. Four antibacterial and three antifungal compounds isolated from the above five isolates were purified and partially characterized using UV absorption and IR spectra. Two antibacterial metabolites, belong to chromone and peptide antibiotic, respectively. The antifungal compounds were found to be of non-polyene nature. In conclusion, we study the isolation of novel bacterial strains of actinomycetes for producing novel compounds having antibacterial and antifungal activities from the unexplored agro-ecological niches of India. Also, this study paves the way for further characterization of these isolates of Streptomyces sp. for their optimum utilization for antimicrobial purposes.

Identification of Two Pathogenic Aeromonas Species Isolated during Production Related Epizootics from Juvenile Burbot Lota lota maculosa.

Science.gov (United States)

Terrazas, Marc M; Anderson, Cort L; Jacobs, Sarah J; Cain, Kenneth D

2018-05-25

In response to population declines of Burbot Lota lota maculosa, conservation aquaculture methods have been developed for this species. In general, Burbot are relatively resistant to many salmonid pathogens; however, cultured juvenile Burbot have experienced periodic epizootic disease outbreaks during production. A series of trials were conducted to determine the virulence of select bacteria isolated from juvenile Burbot following outbreaks that occurred in 2012 and 2013 at the University of Idaho's Aquaculture Research Institute. Initial clinical diagnostics and sampling resulted in the isolation of numerous putative bacterial pathogens. To determine which bacteria were the most likely causative agents contributing to these epizootics, juvenile Burbot were injectied intraperitoneally (IP) with select bacteria in log phase growth. Mortality associated with specific isolates was recorded, and more comprehensive challenges followed this initial screening. These challenges used side-by-side IP and immersion methods to expose Burbot to potential pathogens. The challenges resulted in significantly higher mortalities in fish following IP injection of two Aeromonas sp. isolates compared to controls (P ≤ 0.01), but no difference in mortality for immersion challenged groups was observed (P = 0.42). Results demonstrate that two isolates (Aeromonas sp.) cultured from the epizootics are virulent to Burbot. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Genome analysis of multiple pathogenic isolates of Streptococcus agalactiae : Implications for the microbial "pan-genome"

NARCIS (Netherlands)

Tettelin, H; Masignani, [No Value; Cieslewicz, MJ; Donati, C; Medini, D; Ward, NL; Angiuoli, SV; Crabtree, J; Jones, AL; Durkin, AS; DeBoy, RT; Davidsen, TM; Mora, M; Scarselli, M; Ros, IMY; Peterson, JD; Hauser, CR; Sundaram, JP; Nelson, WC; Madupu, R; Brinkac, LM; Dodson, RJ; Rosovitz, MJ; Sullivan, SA; Daugherty, SC; Haft, DH; Selengut, J; Gwinn, ML; Zhou, LW; Zafar, N; Khouri, H; Radune, D; Dimitrov, G; Watkins, K; O'Connor, KJB; Smith, S; Utterback, TR; White, O; Rubens, CE; Grandi, G; Madoff, LC; Kasper, DL; Telford, JL; Wessels, MR; Rappuoli, R; Fraser, CM

2005-01-01

The development of efficient and inexpensive genome sequencing methods has revolutionized the study of human bacterial pathogens and improved vaccine design. Unfortunately, the sequence of a single genome does not reflect how genetic variability drives pathogenesis within a bacterial species and

Etiology and pathogenicity of two different isolates of Colletotrichum spp. obtained from physic nut seeds

OpenAIRE

Santos,Gil Rodrigues dos; Tozze Júnior,Hugo José; Sá,Danila Alves Corrêa de; Furtado,Gleiber Quintão; Massola Júnior,Nelson Sidnei

2013-01-01

The species known as physic nut (Jatropha curcas L.) has become important as one of main sources of feedstock for biodiesel production. The aims of this study were characterizing two different isolates of Colletotrichum spp. obtained from seeds of this species, through morphological, cultural, and molecular analyses; as well as assessing pathogenicity of both isolates on leaves and fruit of this plant species. For morphological analysis, length and width of 30 spores of each isolate, produced...

Effect of medicinal plants, Heavy metals and antibiotics against pathogenic bacteria isolated from raw, Boiled and pasteurized milk.

Science.gov (United States)

Ali, Nazish Mazhar; Sarwar, Khadija; Mazhar, Syed Abdullah; Liaqat, Iram; Andleeb, Saiqa; Mazhar, Bushra; Kalim, Bushra

2017-11-01

Present study has been undertaken to isolate and identify the bacterial flora in raw, boiled and pasteurized milk. Agar disc diffusion method was used to determine their sensitivity using medicinal plants, antibiotics and heavy metals. Methylene blue reduction test was used to test the quality of milk samples. Total 10 pathogenic strains were isolated, five strains were isolated from raw milk, three from boiled milk and 2 two from pasteurized milk. To determine optimum conditions for growth, these pathogenic microorganisms were incubated at various temperatures and pH. Gram's staining and biochemical tests revealed that these pathogenic bacteria include Lactobacillus sp., E. coli, Salmonella sp., Pseudomonas sp., Streptococcus sp. and Staphylococcus. Ribotyping revealed S2 as Pseudomonas fluorescens, S5 as Lactococcus lactis and S9 as Lactobacillus acidophilus. Prevalence of pathogenic organisms provided the evidence that contamination of milk arises during milking, transportation and storage of milk. Raw milk is more contaminated than other two types of milk because it contains highest percentage of pathogenic organisms and pasteurized milk was found to be of best quality among three types. So it is recommended to drink milk after proper boiling or pasteurization. Proper pasteurization and hygienic packing of milk is essential to minimize contamination in milk which can save human beings from many milk borne diseases. Our study suggests that antimicrobial use in animal husbandry should be minimized to reduce the hazard of antibiotic resistance. Plant extracts are better alternative against pathogenic bacteria in milk.

ANTIMICROBIAL SUSCEPTIBILITY PROFILE OF MICROBIAL PATHOGENS ISOLATED FROM CALVES WITH RESPIRATORY DISEASES

OpenAIRE

George Cosmin Nadas; Flore Chirila; Cosmina Bouari; Nicodim Fit

2016-01-01

Introduction: Respiratory disease in calves is an actual problem, a major cause of economic losses due to mortality, growth delay and improper development. These conditions are frequent in calves due to the weaning stress, transport and environmental changes. Aims: The aim of this study was the isolation of bacteria from 30 calves with respiratory disorders and their antibiotic susceptibility testing. Materials and methods: Samples were collected from calves with respiratory disorders...

Analysis of a food-borne fungal pathogen outbreak: virulence and genome of a Mucor circinelloides isolate from yogurt.

Science.gov (United States)

Lee, Soo Chan; Billmyre, R Blake; Li, Alicia; Carson, Sandra; Sykes, Sean M; Huh, Eun Young; Mieczkowski, Piotr; Ko, Dennis C; Cuomo, Christina A; Heitman, Joseph

2014-07-08

Food-borne pathogens are ongoing problems, and new pathogens are emerging. The impact of fungi, however, is largely underestimated. Recently, commercial yogurts contaminated with Mucor circinelloides were sold, and >200 consumers became ill with nausea, vomiting, and diarrhea. Mucoralean fungi cause the fatal fungal infection mucormycosis, whose incidence has been continuously increasing. In this study, we isolated an M. circinelloides strain from a yogurt container, and multilocus sequence typing identified the strain as Mucor circinelloides f. circinelloides. M. circinelloides f. circinelloides is the most virulent M. circinelloides subspecies and is commonly associated with human infections, whereas M. circinelloides f. lusitanicus and M. circinelloides f. griseocyanus are less common causes of infection. Whole-genome analysis of the yogurt isolate confirmed it as being close to the M. circinelloides f. circinelloides subgroup, with a higher percentage of divergence with the M. circinelloides f. lusitanicus subgroup. In mating assays, the yogurt isolate formed sexual zygospores with the (-) M. circinelloides f. circinelloides tester strain, which is congruent with its sex locus encoding SexP, the (+) mating type sex determinant. The yogurt isolate was virulent in murine and wax moth larva host systems. In a murine gastromucormycosis model, Mucor was recovered from fecal samples of infected mice for up to 10 days, indicating that Mucor can survive transit through the GI tract. In interactions with human immune cells, M. circinelloides f. lusitanicus induced proinflammatory cytokines but M. circinelloides f. circinelloides did not, which may explain the different levels of virulence in mammalian hosts. This study demonstrates that M. circinelloides can spoil food products and cause gastrointestinal illness in consumers and may pose a particular risk to immunocompromised patients. Importance: The U.S. FDA reported that yogurt products were contaminated with M

Microbial Gas Generation Under Expected Waste Isolation Pilot Plant Repository Conditions: Final Report

Energy Technology Data Exchange (ETDEWEB)

Gillow, J.B.; Francis, A.

2011-07-01

Gas generation from the microbial degradation of the organic constituents of transuranic (TRU) waste under conditions expected in the Waste Isolation Pilot Plant (WIPP) was investigated. The biodegradation of mixed cellulosic materials and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, hypalon, leaded hypalon, and neoprene) was examined. We evaluated the effects of environmental variables such as initial atmosphere (air or nitrogen), water content (humid ({approx}70% relative humidity, RH) and brine inundated), and nutrient amendments (nitogen phosphate, yeast extract, and excess nitrate) on microbial gas generation. Total gas production was determined by pressure measurement and carbon dioxide (CO{sub 2}) and methane (CH{sub 4}) were analyzed by gas chromatography; cellulose degradation products in solution were analyzed by high-performance liquid chromatography. Microbial populations in the samples were determined by direct microscopy and molecular analysis. The results of this work are summarized.

Effect of sampling and short isolation methodologies on the recovery of human pathogenic Yersinia enterocolitica from pig tonsils.

Science.gov (United States)

Van Damme, Inge; Berkvens, Dirk; De Zutter, Lieven

2012-07-01

The objective of this study was to determine the effect of sampling (swab samples compared to destructive samples) on isolation rates of human pathogenic Yersinia enterocolitica from pig tonsils. Moreover, the relative efficiency of different rapid, routinely applicable isolation methods was evaluated. Therefore, swab and destructive samples from tonsils of 120 pigs at slaughter were analyzed in parallel using direct plating and different enrichment methods. Salmonella-Shigella-desoxycholate-calcium chloride (SSDC) agar, cefsulodin-irgasan-novobiocin (CIN) agar, and Yersinia enterocolitica chromogenic medium (YeCM) were used as selective agar media. For enrichment, irgasan-ticarcillin-potassium chlorate (ITC) broth and peptone-sorbitol-bile (PSB) broth were incubated at 25°C for 48 h. Overall, 55 tonsils (45.8%) were positive for Y. enterocolitica bioserotype 4/O:3. Recovery was significantly higher using the destructive method compared to the swabbing method. Direct plating resulted in 47 and 28 Y. enterocolitica-positive destructive and swab samples, respectively. Alkali treatment of PSB and ITC enrichment broths significantly increased recovery of pathogenic Y. enterocolitica from destructive tonsil samples. The performance of YeCM for qualitative and quantitative isolation of pathogenic Y. enterocolitica from pig tonsils was equal to SSDC and CIN. In conclusion, direct plating and ISO 10273: 2003 with minor modifications are suitable and rapid methods for isolation of pathogenic Y. enterocolitica from destructive tonsil samples.

Use of static Quantitative Microbial Risk Assessment to determine pathogen risks in an unconfined carbonate aquifer used for Managed Aquifer Recharge.

Science.gov (United States)

Toze, Simon; Bekele, Elise; Page, Declan; Sidhu, Jatinder; Shackleton, Mark

2010-02-01

Managed Aquifer Recharge (MAR) is becoming a mechanism used for recycling treated wastewater and captured urban stormwater and is being used as a treatment barrier to remove contaminants such as pathogens from the recharged water. There is still a need, however, to demonstrate the effectiveness of MAR to reduce any residual risk of pathogens in the recovered water. A MAR research site recharging secondary treated wastewater in an unconfined carbonate aquifer was used in conjunction with a static Quantitative Microbial Risk Assessment (QMRA) to assess the microbial pathogen risk in the recovered water following infiltration and aquifer passage. The research involved undertaking a detailed hydrogeological assessment of the aquifer at the MAR site and determining the decay rates of reference pathogens from an in-situ decay study. These variables along with literature data were then used in the static QMRA which demonstrated that the recovered water at this site did not meet the Australian Guidelines for recycled water when used for differing private green space irrigation scenarios. The results also confirmed the importance of obtaining local hydrogeological data as local heterogeneity can influence of residence time in the aquifer which, in turn, influences the outcomes. The research demonstrated that a static QMRA can be used to determine the residual risk from pathogens in recovered water and showed that it can be a valuable tool in the preliminary design and operation of MAR systems and the incorporation of complementary engineered treatment processes to ensure that there is acceptable health risk from the recovered water. Crown Copyright 2009. Published by Elsevier Ltd. All rights reserved.

Presence of pathogenicity island genes in Enterococcus faecalis isolates from pigs in Denmark

DEFF Research Database (Denmark)

Shankar, Nathan; Baghdayan, Arto S.; Willems, Rob

2006-01-01

Enterococcus faecalis isolates of porcine origin were screened for the presence of a previously identified pathogenicity island (PAI). By using the esp gene as a genetic marker for the presence of this PAI, 9 esp-positive and 10 esp-negative isolates of porcine origin were investigated by use...... of a designed oligonucleotide array. The results indicated the clustering of esp-positive strains by multilocus sequence typing (MLST), but surprisingly, all strains investigated contained parts of the PAL None of the strains of animal origin investigated belonged to previously identified MLST complex 2, where...... most isolates from patients cluster. Five of the nine esp-positive E. faecalis isolates of animal origin belonged to the same PAI complex as human isolate MMH594 but differed in their sequence types, which strongly indicates the horizontal transfer of the PAI between enterococci of porcine and human...

European apple canker: morphophysiological variability and pathogenicity in isolates of Neonectria ditissima in southern Brazil

Directory of Open Access Journals (Sweden)

Jonatas da Silva Campos

Full Text Available ABSTRACT: European apple canker (EC is caused by Neonectria ditissima, a pathogen officially registered as a quarantine pest in 2012. Thirty-five isolates of N. ditissima of different geographical regions of southern Brazil from apple branches showing symptoms of EC were identified by the specific pair primers Ch1 and Ch2 and analyzed concerning the virulence on Gala apple cultivar and morphophysiological characteristics. The disease symptoms were characterized and the isolates compared based on average mycelium growth (AMG, mycelium growth index (MGI, colony color, conidia type, dimensions and growth on potato dextrose agar (PDA, malt agar (AM, and synthetic SNAY (SN culture media. Nineteen isolates showed the greatest AMG on PDA, forming three growth groups of 35.56 (GI, 52.71 (GII, and 62.67mm (GIII. Seven isolates showed MGI greater than 4.0mm diameter on PDA compared with that on AM and SN. The highest conidia production was on SN, and the predominant colony color in all media was white to beige with central pigmentation of brown and borders colored in shades of beige. There were significant differences among the average dimensions of micro- and macroconidia on PDA, AM, and SN. The pathogenicity was confirmed for all isolates despite of different morphophysiological characteristics. There was no correlation among isolates morphophysiological variability, virulence, and geographical origin.

MALDI-TOF mass spectrometry: an emerging technology for microbial identification and diagnosis.

Science.gov (United States)

Singhal, Neelja; Kumar, Manish; Kanaujia, Pawan K; Virdi, Jugsharan S

2015-01-01

Currently microorganisms are best identified using 16S rRNA and 18S rRNA gene sequencing. However, in recent years matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a potential tool for microbial identification and diagnosis. During the MALDI-TOF MS process, microbes are identified using either intact cells or cell extracts. The process is rapid, sensitive, and economical in terms of both labor and costs involved. The technology has been readily imbibed by microbiologists who have reported usage of MALDI-TOF MS for a number of purposes like, microbial identification and strain typing, epidemiological studies, detection of biological warfare agents, detection of water- and food-borne pathogens, detection of antibiotic resistance and detection of blood and urinary tract pathogens etc. The limitation of the technology is that identification of new isolates is possible only if the spectral database contains peptide mass fingerprints of the type strains of specific genera/species/subspecies/strains. This review provides an overview of the status and recent applications of mass spectrometry for microbial identification. It also explores the usefulness of this exciting new technology for diagnosis of diseases caused by bacteria, viruses, and fungi.

Identification of fungal plant pathogens associated with oak (Quercus humboldtii Bonpl.), In the municipalities of Encino (Santander), Arcabuco, and Tipacoque (Boyaca)

International Nuclear Information System (INIS)

Monroy Castro, Leidi Yunari; Lizarazo Forero, Luz Marina

2010-01-01

The objectives of this study were to isolate and determine the presence of the pathogen Phytophthora ramorum and other potential pathogens of Quercus humboldtii, and evaluate the possibility of using the antagonistic capacity of bacteria isolated from rhizosphere and phyllosphere against them. The study was conducted in the conservation corridor Guantiva - La Rusia - Iguaque, in the municipalities of Encino (Santander), Arcabuco and Tipacoque (Boyaca). The phytopathogenic fungi were isolated using direct seeding of leaves with symptoms of fungal infection in OGY, Sabouraud, and PDA + Lactic acid at 0.2%. We used the plate counting technique for the isolation of bacteria from rhizospheric and bulk soil. Phytophthora ramorum was not isolated, but phytopathogenic fungi of the genus Fusarium spp., and Pestalotia spp., were obtained in the isolates. Microbial populations of rhizospheric and bulk soil were scarce, exhibited low diversity, and were dominated by few morphotypes. We identified four species of bacteria: Pseudomonas fluorescens, Bacillus macerans, Pinus sylvestris and Staphylococcus epidermidis. The phyllosphere community was dominated by Pseudomonas fluorescens. The species Pseudomonas fluorescens and Pinus sylvestris did not exhibited antagonistic properties against Pestalotia spp. Further studies are required to confirm Fusarium spp., and Pestalotia spp., pathogenic activity against Quercus humboldtii.

Comparative pathogenicity of early and recent isolates of avian metapneumovirus subtype C in turkeys.

Science.gov (United States)

Velayudhan, Binu T; Noll, Sally L; Thachil, Anil J; Halvorson, David A; Shaw, Daniel P; Goyal, Sagar M; Nagaraja, Kakambi V

2008-07-01

The objective of the present study was to compare the pathogenicity of early and recent isolates of avian metapneumovirus subtype-C (aMPV-C) in turkeys. Two-week-old turkeys were inoculated with early and recent isolates of aMPV-C. Clinical signs were monitored. Tissues were examined for viral ribonucleic acid (RNA), lesions, and viral antigen by reverse transcription-polymerase chain reaction (RT-PCR), histopathology and immunohistochemistry, respectively. Birds infected with the recent isolate had higher clinical sign scores than those infected with the early isolate. Only the recent isolate produced a multifocal loss of cilia in the nasal turbinate of infected birds. Immunohistochemistry revealed intense staining of aMPV antigen in turbinate and trachea of birds infected with the recent isolate. The findings indicate that the recent isolate produced more severe clinical signs and lesions in turkeys compared to the early isolate. The recent isolate could be ideal for the development of a challenge model for aMPV infection in turkeys.

Microbial Flora Isolated from Polluted and Non-Polluted Coastal Waters of Karachi

International Nuclear Information System (INIS)

Shaheen, A.; Baig, H. S.; Kazmi, S. U.

2016-01-01

Marine pollution has now become worldwide environmental concern. Continuous discharge of untreated industrial effluent, municipal and power plant contaminated wastewater has been a serious threat to marine habitat, aesthetic values and interest of visitors to coastal areas. Karachi is the largest city of Pakistan and industrial hub of the Arabian Sea. In this investigation, samples of sediment, water, flora and fauna were taken from nine selected stations on Karachi coast included three stations represented major creeks i.e. Korangi, Gizri and Chinna Creek. These samples were taken during north-east and south-west monsoonal period in 2014. Bacterial flora isolated and identified from samples collected from these sites by conventional method. Among isolated and identified bacteria e.g. Vibrio alginolyticus, Escherichia coli and Streptococuss anginosus were the most dominant species contributing 21.43, 19.64 and 15.18 percent of total assemblage respectively. Among selected sample stations, Korangi creek station was found to be most polluted with coliform and other pathogenic bacteria. These results clearly indicate that threats from these pathogens are not only to marine life but also to the large number of visitors coming to beaches and residents of surrounding area. Moreover; immediate action should be taken to restrict the growth of these pathogens by taking measures to treat the municipal and industrial effluent to avoid outbreak of any disease in future. (author)

The Effectiveness of Heterotrophic Bacteria Isolated from Dumai Marine Waters of Riau, Used as Antibacterial against Pathogens in Fish Culture

Science.gov (United States)

Feliatra, F.; Nursyirwani; Tanjung, A.; Adithiya, DS; Susanna, M.; Lukystyowati, I.

2018-02-01

Heterotrophic bacteria have an important role as decomposer of organic compounds (mineralization) derived from industrial waste, decomposition of unconsumed feed, faecal, excretion of fish, and have the ability to inhibit the growth of pathogenic bacteria. We investigated the role of heterotrophic bacteria used as antibacterial against pathogens in fish culture.This research was conducted from January until March 2017. The phylogenitic of the isolated bacterial was determined by 16S rDNA sequences analysis. Antagonism test showed that the bacteria had the ability to inhibit the growth of pathogenic bacteria (Vibrio alginolyticus, Aeromonas hydrophila and Pseudomonas sp.) Three isolates (Dm5, Dm6 and Dm4) indicated high inhibition zones which were classified into strong category with the average from 10.5 to 11.8 mm toward V. alginolitycus. Other isolates were classified into medium and weak category. Based on DNA analysis of heterotrophic bacteria isolated from marine waters of industrial area and low salinity of estuarine waters twelve strains of bacteria were identified, and all had highest level of homology to Bacillus sp.,one isolates has similarity to Enterobacter cloacae, other isolates to Clostridium cetobutylicum. Most of isolated bacteria obtained from the waters of industrial area due to it received much of nutrients that very influenced the growth of bacteria.

[Fibers as carriers of microbial particles].

Science.gov (United States)

Górny, Rafał L; Ławniczek-Wałczyk, Anna; Stobnicka, Agata; Gołofit-Szymczak, Małgorzata; Cyprowski, Marcin

2015-01-01

The aim of the study was to assess the ability of natural, synthetic and semi-synthetic fibers to transport microbial particles. The simultaneously settled dust and aerosol sampling was carried out in 3 industrial facilities processing natural (cotton, silk, flax, hemp), synthetic (polyamide, polyester, polyacrylonitrile, polypropylene) and semi-synthetic (viscose) fibrous materials; 2 stables where horses and sheep were bred; 4 homes where dogs or cats were kept and 1 zoo lion pavilion. All samples were laboratory analyzed for their microbiological purity. The isolated strains were qualitatively identified. To identify the structure and arrangement of fibers that may support transport of microbial particles, a scanning electron microscopy analysis was performed. Both settled and airborne fibers transported analogous microorganisms. All synthetic, semi-synthetic and silk fibers, present as separated threads with smooth surface, were free from microbial contamination. Natural fibers with loose packing and rough surface (e.g., wool, horse hair), sheaf packing and septated surface (e.g., flax, hemp) or present as twisted ribbons with corrugated surface (cotton) were able to carry up to 9×10(5) cfu/g aerobic bacteria, 3.4×10(4) cfu/g anaerobic bacteria and 6.3×10(4) cfu/g of fungi, including pathogenic strains classified by Directive 2000/54/EC in hazard group 2. As plant and animal fibers are contaminated with a significant number of microorganisms, including pathogens, all of them should be mechanically eliminated from the environment. In factories, if the manufacturing process allows, they should be replaced by synthetic or semi-synthetic fibers. To avoid unwanted exposure to harmful microbial agents on fibers, the containment measures that efficiently limit their presence and dissemination in both occupational and non-occupational environments should be introduced. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Fibers as carriers of microbial particles

Directory of Open Access Journals (Sweden)

Rafał L. Górny

2015-08-01

Full Text Available Background: The aim of the study was to assess the ability of natural, synthetic and semi-synthetic fibers to transport microbial particles. Material and Methods: The simultaneously settled dust and aerosol sampling was carried out in 3 industrial facilities processing natural (cotton, silk, flax, hemp, synthetic (polyamide, polyester, polyacrylonitrile, polypropylene and semi-synthetic (viscose fibrous materials; 2 stables where horses and sheep were bred; 4 homes where dogs or cats were kept and 1 zoo lion pavilion. All samples were laboratory analyzed for their microbiological purity. The isolated strains were qualitatively identified. To identify the structure and arrangement of fibers that may support transport of microbial particles, a scanning electron microscopy analysis was performed. Results: Both settled and airborne fibers transported analogous microorganisms. All synthetic, semi-synthetic and silk fibers, present as separated threads with smooth surface, were free from microbial contamination. Natural fibers with loose packing and rough surface (e.g., wool, horse hair, sheaf packing and septated surface (e.g., flax, hemp or present as twisted ribbons with corrugated surface (cotton were able to carry up to 9×105 cfu/g aerobic bacteria, 3.4×104 cfu/g anaerobic bacteria and 6.3×104 cfu/g of fungi, including pathogenic strains classified by Directive 2000/54/EC in hazard group 2. Conclusions: As plant and animal fibers are contaminated with a significant number of microorganisms, including pathogens, all of them should be mechanically eliminated from the environment. In factories, if the manufacturing process allows, they should be replaced by synthetic or semi-synthetic fibers. To avoid unwanted exposure to harmful microbial agents on fibers, the containment measures that efficiently limit their presence and dissemination in both occupational and non-occupational environments should be introduced. Med Pr 2015;66(4:511–523

Relationships among superantigen toxin gene profiles, genotypes, and pathogenic characteristics of Staphylococcus aureus isolates from bovine mastitis.

Science.gov (United States)

Wang, Dong; Zhang, Limei; Yong, Changfu; Shen, Mingliang; Ali, Tariq; Shahid, Muhammad; Han, Kun; Zhou, Xuezhang; Han, Bo

2017-06-01

Staphylococcus aureus is one of the major etiological agents of bovine mastitis, harboring a wide variety of staphylococcal superantigen (SAg) toxin genes. The SAg toxin genes are reported to be closely associated with the pathogenicity of the Staph. aureus causing the bovine mastitis. This study was conducted to investigate SAg toxin gene profiles and to assess the relationships among SAg toxin genes, genotypes of Staph. aureus, and their pathogenic properties. A total of 327 quarter milk samples were collected from bovine mastitis cases for isolation and identification of pathogens. In total, 35 isolates were identified as Staph. aureus, and the prevalence of Staph. aureus in milk samples was 13.6% (35/256). Polymerase chain reaction (PCR) and randomly amplified polymorphic DNA (RAPD) assays were used to detect the SAg toxin genes and to genotype Staph. aureus strains isolated from milk samples of bovine mastitis in 10 dairy herds located in Ningxia, China, respectively. The results showed that among the Staph. aureus isolates (n = 35), 71.4% (n = 25) of isolates carried at least one SAg toxin gene. In total, 18 SAg genes and 21 different gene combination patterns were detected among these isolates. The most common SAg genes in Staph. aureus isolates were sei, sen, and seu (44.0% each), followed by seo, tst, and etB (28.0% each), etA (24.0%), sem and sep (16.0% each), seb, sec, sed, and sek (12.0% each), and sea and seh genes (8.0% each); the seg, sej, and ser genes were present in 4.0% of the isolates. Three gene combinations were found to be related to mobile genetic elements that carried 2 or more genes. The egc-cluster of the seg-sei-sem-sen-seo genes, located on the pathogenicity island Type I υSaβ, was detected in 16% of isolates. Interestingly, we observed 6 RAPD genotypes (I to VI) in Staph. aureus isolates, and 2 of these genotypes were strongly associated with the severity of bovine mastitis; there was a close relationship between the RAPD genotypes

Isolation and in vitro cultivation of the aphid pathogenic fungus Entomophthora planchoniana.

Science.gov (United States)

Freimoser, F M; Jensen, A B; Tuor, U; Aebi, M; Eilenberg, J

2001-12-01

Entomophthora planchoniana is an important fungal pathogen of aphids. Although Entomophthora chromaphidis has been considered a synonym for E. planchoniana, the two species are now separated, and E. planchoniana is reported not to grow in vitro. In this paper, we describe for the first time the isolation and cultivation of this species. Entomophthora planchoniana was isolated from a population of Ovatus crataegarius (Homoptera, Aphididae), which was infected by E. planchoniana only. The isolates did not sporulate, but the sequence of the small subunit rDNA and the restriction fragment length polymorphism patterns of the first part of the large subunit rDNA and the ITS II region confirm that the isolates were E. planchoniana. The isolated fungus grew in a medium consisting of Grace's insect cell culture medium supplemented with lactalbumin hydrolysate, yeastolate, and 10% fetal bovine serum or in GLEN medium with 10% fetal bovine serum. Vegetative cells of E. planchoniana were long and club-shaped and did not stain with Calcofluor, thus suggesting that they were protoplasts.

Study of Microbial Contamination of the Public Swimming Pools with Escherichia coli and Pseudomonas aeruginosa and Their Physical Parameters in Kermanshah, Iran

Directory of Open Access Journals (Sweden)

Afsaneh Haghmorad Korasti

2016-09-01

Full Text Available Background and Objectives: Public swimming pools' waters are contaminated with a wide variety of pathogenic microorganisms and are a suitable environment for transmission of different diseases. The aim of this study was to investigate the microbial contamination of the public swimming pools' waters with Escherichia coli and Pseudomonas aeruginosa and to determine certain parameters such as residual chlorine, pH, temperature and turbidity in these pools' waters in Kermanshah. In this descriptive, cross-sectional study, 129 water samples were taken from all active pools in Kermanshah and their bacteriologic and physicochemical properties were investigated. Phosphatase alkaline (PHO-A gene was used for molecular confirmation of E. coli isolates, and exotoxin A (ETA gene in PCR was employed to confirm pathogenicity of P. aeruginosa isolates. Data were analyzed by chi-square and t-test. p0.05. Conclusion: The results of this study indicated that appropriate amount of residual chlorine caused reduction in microbial contamination in the public swimming pools' waters in Kermanshah.

Isolation of pathogenic Yersinia enterocolitica 1B/O:8 from Apodemus mice in Japan.

Science.gov (United States)

Oda, Shinya; Kabeya, Hidenori; Sato, Shingo; Shimonagane, Ai; Inoue, Kai; Hayashidani, Hideki; Takada, Nobuhiro; Fujita, Hiromi; Kawabata, Hiroki; Maruyama, Soichi

2015-01-01

Yersinia enterocolitica was isolated from 15.7% (88/560) of wild rodents captured in 15 prefectures in Japan. Prevalences by rodent species were 18.0% (70/388) in Japanese field mice (Apodemus speciosus), 20% (14/71) in small Japanese field mice (Apodemus argenteus), and 11% (4/38) in gray red-backed vole (Myodes rufocanus bedfordiae), suggesting that these rodent species are important reservoirs of Y. enterocolitica. Although most of the isolates were identified as biotype 1A, the pathogenic bioserotype 1B/O:8 was detected in one of the A. speciosus and in three of the A. argenteus captured in Aomori Prefecture. It is suggested that Apodemus mice may be an important reservoir of Y. enterocolitica, and that there are foci of the pathogenic bioserotype 1B/O:8 in Aomori Prefecture, because human sporadic cases by the serotype have been reported in this prefecture.

Virulence gene profiles of avian pathogenic Escherichia coli isolated from chickens with colibacillosis in Bulawayo, Zimbabwe

Directory of Open Access Journals (Sweden)

Joshua Mbanga

2015-04-01

Full Text Available Colibacillosis, a disease caused by avian pathogenic Escherichia coli (APEC, is one of the main causes of economic losses in the poultry industry worldwide. This study was carried out in order to determine the APEC-associated virulence genes contained by E. coli isolates causing colibacillosis in chickens. A total of 45 E. coli isolates were obtained from the diagnostics and research branch of the Central Veterinary Laboratories, Bulawayo, Zimbabwe. These isolates were obtained from chickens with confirmed cases of colibacillosis after postmortem examination. The presence of the iutA, hlyF, ompT, frz, sitD, fimH, kpsM, sitA, sopB, uvrY, pstB and vat genes were investigated by multiplex polymerase chain reaction (PCR assay. Of the 45 isolates, 93% were positive for the presence of at least one virulence gene. The three most prevalent virulence genes were iutA (80%, fimH (33.3% and hlyF (24.4%. The kpsM, pstB and ompT genes had the lowest prevalence, having been detected in only 2.2% of the isolates. All 12 virulence genes studied were detected in the 45 APEC isolates. Virulence gene profiles were constructed for each APEC isolate from the multiplex data. The APEC isolates were profiled as 62.2% fitting profile A, 31.1% profile B and 6.7% profile C. None of the isolates had more than seven virulence genes. Virulence profiles of Zimbabwean APEC isolates are different from those previously reported. Zimbabwean APEC isolates appear to be less pathogenic and may rely on environmental factors and stress in hosts to establish infection.

Dual Effects of Lactobacilli as a Cholesterol Assimilator and an Inhibitor ofGastrointestinal Pathogenic Bacteria

Directory of Open Access Journals (Sweden)

Amir Emami

2014-02-01

Full Text Available Background: Probiotics are live microbial supplements which can improve the healthy intestinal microbial balance. Lactobacilli are a group of lactic acid producing bacteria (LAB that are known as natural probiotics found in the dairy products. Objectives: In this study, we aimed to detect the most potent Lactobacillus isolates of the Fars province local dairy products in cholesterol removal and investigate their antibacterial properties against some gastrointestinal pathogens. Materials and Methods: Fifteen locally produced yogurt samples of the Fars province were collected and characterized with routine microbiology methods. Cholesterol removal ability of the Lactobacilli isolates were determined, and their growth inhibitory effect on some standard pathogenic strains pathogen was evaluated using the well-diffusion method. Results: In this study, five common strains of Lactobacilli including L. acidophilus, L. casei, L. fermentum, L. lactis, and L. bulgaricus were identified in the samples obtained from the locally produced yogurt in the Fars province. L. lactis and L. acidophilus were determined as the two most active strains with the maximum rate of cholesterol assimilation (5.6 and 4.5 mg/mL, respectively in the process of cholesterol removal. In the antibacterial activity assay, the two mentioned strains had significant inhibitory effect on all of the tested bacteria except for B. subtilis. Conclusions: Cholesterol removal ability had a direct relation with bacterial growth, so it is suggested to use the probiotic bacteria in the growth phase to achieve better results.

Molecular Mechanisms of Bacterial Pathogenicity

Science.gov (United States)

Fuchs, Thilo Martin

Cautious optimism has arisen over recent decades with respect to the long struggle against bacteria, viruses, and parasites. This has been offset, however, by a fatal complacency stemming from previous successes such as the development of antimicrobial drugs, the eradication of smallpox, and global immunization programs. Infectious diseases nevertheless remain the world's leading cause of death, killing at least 17 million persons annually [61]. Diarrheal diseases caused by Vibrio cholerae or Shigella dysenteriae kill about 3 million persons every year, most of them young children: Another 4 million die of tuberculosis or tetanus. Outbreaks of diphtheria in Eastern Europe threatens the population with a disease that had previously seemed to be overcome. Efforts to control infectious diseases more comprehensively are undermined not only by socioeconomic conditions but also by the nature of the pathogenic organisms itself; some isolates of Staphylococcus aureus and Enterobacter have become so resistant to drugs by horizontal gene transfer that they are almost untreatable. In addition, the mechanism of genetic variability helps pathogens to evade the human immune system, thus compromising the development of powerful vaccines. Therefore detailed knowledge of the molecular mechanisms of microbial pathogenicity is absolutely necessary to develop new strategies against infectious diseases and thus to lower their impact on human health and social development.

Genomic and Phenotypic Variation in Morphogenetic Networks of Two Candida albicans Isolates Subtends Their Different Pathogenic Potential

Directory of Open Access Journals (Sweden)

Duccio Cavalieri

2018-01-01

Full Text Available The transition from commensalism to pathogenicity of Candida albicans reflects both the host inability to mount specific immune responses and the microorganism’s dimorphic switch efficiency. In this study, we used whole genome sequencing and microarray analysis to investigate the genomic determinants of the phenotypic changes observed in two C. albicans clinical isolates (YL1 and YQ2. In vitro experiments employing epithelial, microglial, and peripheral blood mononuclear cells were thus used to evaluate C. albicans isolates interaction with first line host defenses, measuring adhesion, susceptibility to phagocytosis, and induction of secretory responses. Moreover, a murine model of peritoneal infection was used to compare the in vivo pathogenic potential of the two isolates. Genome sequence and gene expression analysis of C. albicans YL1 and YQ2 showed significant changes in cellular pathways involved in environmental stress response, adhesion, filamentous growth, invasiveness, and dimorphic transition. This was in accordance with the observed marked phenotypic differences in biofilm production, dimorphic switch efficiency, cell adhesion, invasion, and survival to phagocyte-mediated host defenses. The mutations in key regulators of the hyphal growth pathway in the more virulent strain corresponded to an overall greater number of budding yeast cells released. Compared to YQ2, YL1 consistently showed enhanced pathogenic potential, since in vitro, it was less susceptible to ingestion by phagocytic cells and more efficient in invading epithelial cells, while in vivo YL1 was more effective than YQ2 in recruiting inflammatory cells, eliciting IL-1β response and eluding phagocytic cells. Overall, these results indicate an unexpected isolate-specific variation in pathways important for host invasion and colonization, showing how the genetic background of C. albicans may greatly affect its behavior both in vitro and in vivo. Based on this approach, we

Evolution of microbial pathogens.

OpenAIRE

Morschhäuser, J; Köhler, G; Ziebuhr, W; Blum-Oehler, G; Dobrindt, U; Hacker, J

2000-01-01

Various genetic mechanisms including point mutations, genetic rearrangements and lateral gene transfer processes contribute to the evolution of microbes. Long-term processes leading to the development of new species or subspecies are termed macroevolution, and short-term developments, which occur during days or weeks, are considered as microevolution. Both processes, macro- and microevolution need horizontal gene transfer, which is particularly important for the development of pathogenic micr...

Magazines in waiting areas of hospital: a forgotten microbial reservoir?

Science.gov (United States)

Adé, Mathias; Burger, Sandrine; Cuntzmann, Anaelle; Exinger, Julien; Meunier, Olivier

2017-12-01

The hospital environment is a potential source of microbial contamination. Thus, the magazines in hospital's waiting rooms are handled by patients and visitors whose health and hygiene conditions can vary widely. In this context, we had measured the microbial load on the surface of magazines. Fifteen magazines from 5 waiting rooms of hospital are sampled by agar prints at the areas taken in hand. The agar plates are incubated at 30̊C for 72h. The colonies are counted and identified by MALDI-TOF mass spectrometry (Vitek ® -MS). The extraction efficiency of bacteria by the agar print method on the magazines is calculated. All the samples highlight a varied bacterial flora: 32CFU/agar in mean. Isolated bacteria come principally from the skin flora (>60%), but we also isolate potentially pathogenic micro-organisme like S. aureus, E. faecalis, A. viridans and Aspergillus sp. as well as oropharyngeal flora bacteria like A. iwolfii and M. osloensis and fecal like B. stercoris. Some species rarely described in hospital are also isolated such as P. yeei or K. sedentarius. The extraction efficiency of the sampling method on a magazine is 36%. Our study, which is the first to be interested in the bacterial contamination of magazines in hospital, could make them consider as microbial reservoir to be controlled, especially for the most fragile patients. New bacterial identification techniques as the MALDI-TOF allow to reveal the presence of rarely described and often underestimated species.

Rearing Water Treatment Induces Microbial Selection Influencing the Microbiota and Pathogen Associated Transcripts of Cod (Gadus morhua Larvae

Directory of Open Access Journals (Sweden)

Ragnhild I. Vestrum

2018-05-01

Full Text Available We have previously shown that K-selection and microbial stability in the rearing water increases survival and growth of Atlantic cod (Gadus morhua larvae, and that recirculating aquaculture systems (RAS are compatible with this. Here, we have assessed how water treatment influenced the larval microbiota and host responses at the gene expression level. Cod larvae were reared with two different rearing water systems: a RAS and a flow-through system (FTS. The water microbiota was examined using a 16S rDNA PCR/DGGE strategy. RNA extracted from larvae at 8, 13, and 17 days post hatching was used for microbiota and microarray gene expression analysis. Bacterial cDNA was synthesized and used for 16S rRNA amplicon 454 pyrosequencing of larval microbiota. Both water and larval microbiota differed significantly between the systems, and the larval microbiota appeared to become more dissimilar between systems with time. In total 4 phyla were identified for all larvae: Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. The most profound difference in larval microbiota was a high abundance of Arcobacter (Epsilonproteobacteria in FTS larvae (34 ± 9% of total reads. Arcobacter includes several species that are known pathogens for humans and animals. Cod larval transcriptome responses were investigated using an oligonucleotide gene expression microarray covering approximately 24,000 genes. Interestingly, FTS larvae transcriptional profiles revealed an overrepresentation of upregulated transcripts associated with responses to pathogens and infections, such as c1ql3-like, pglyrp-2-like and zg16, compared to RAS larvae. In conclusion, distinct water treatment systems induced differences in the larval microbiota. FTS larvae showed up-regulation of transcripts associated with responses to microbial stress. These results are consistent with the hypothesis that RAS promotes K-selection and microbial stability by maintaining a microbial load close to the

Isolation, antibiogram and pathogenicity of Salmonella spp. Recovered from slaughtered food animals in Nagpur region of Central India

Directory of Open Access Journals (Sweden)

D. G. Kalambhe

2016-02-01

Full Text Available Aim: To determine the prevalence, antibiogram and pathogenicity of Salmonella spp. in the common food animals slaughtered for consumption purpose at government approved slaughter houses located in and around Nagpur region during a period of 2010-2012. Materials and Methods: A total of 400 samples comprising 50 each of blood and meat from each slaughtered male cattle, buffaloes, pigs and goats were collected. Isolation was done by pre-enrichment in buffered peptone water and enrichment in Rappaport-Vassiliadis broth with subsequent selective plating onto xylose lysine deoxycholate agar. Presumptive Salmonella colonies were biochemically confirmed and analyzed for pathogenicity by hemolysin production and Congo red dye binding assay (CRDA. An antibiotic sensitivity test was performed to assess the antibiotic resistance pattern of the isolates. Results: A total of 10 isolates of Salmonella spp. from meat (3 from cattle, 1 from buffaloes and 6 from pigs with an overall prevalence of 5% among food animals was recorded. No isolation was reported from any blood samples. Pathogenicity assays revealed 100% and 80% positivity for CRDA and hemolytic activity, respectively. Antimicrobial sensitivity test showed multi-drug resistance. The overall resistance of 50% was noted for trimethoprim followed by ampicillin (20%. A maximum sensitivity (80% was reported to gentamycin followed by 40% each to ampicillin and trimethoprim, 30% to amikacin and 10% to kanamycin. Conclusion: The presence of multidrug resistant and potentially pathogenic Salmonella spp. in slaughtered food animals in Nagpur region can be a matter of concern for public health.

Distribution of pathogenic microorganisms isolated from dental hospital workers in Korea

Directory of Open Access Journals (Sweden)

Su Jung Kim

2013-04-01

Full Text Available With the significant rise in hospital infection management in dental hospitals as well as in hospitals, and in order to identify the distribution of pathogenic bacteria on hands and nasal cavity of workers in a dental hospital, bacteria from the hands and nasal cavities of six dentists and 44 dental hygienists from four dental hospitals were investigated. The results showed Staphylococcus aureus (13, Staphylococcus capitis (1, Staphylococcus epidermidis (12, Staphylococcus hominis (4, Staphylococcus warneri (3, Staphylococcus xylosus (14, Staphylococcus. Lugdunensis (1, and Neisseria spp. (2 were isolated from the nasal cavity and Staphylococcus aureus (9, Staphylococcus capitis (4, Staphylococcus epidermidis (16, Staphylococcus hominis (8, Staphylococcus warneri (5, Staphylococcus xylosus (22, Staphylococcus leutus (3, Micrococcus spp. (4, Staphylococcus cohnii (1, Serratia marcescens (2, Pseudomonas aeruginosa (3, Klebsiella pneumonia (2 and Pseudomonas pneumotropica (1 from the hands. An antimicrobial disk diffusion test was conducted on Staphylococcus aureus isolated from the hands and nasal cavity to detect MRSA by means of oxacillin. Two strains were detected. When the genes of penicillin binding protein 2 (mecA were detected from the 2 strains, MRSA was found from both strains. The results of this investigation on the distribution of various pathogenic bacteria and MRSA on hands and nasal cavity of workers of a dental hospital, will contribute to the basic data for the future infection management in a dental hospital.

Detection of foodborne pathogens by qPCR: A practical approach for food industry applications

Directory of Open Access Journals (Sweden)

María-José Chapela

2015-12-01

Full Text Available Microbiological analysis of food is an integrated part of microbial safety management in the food chain. Monitoring and controlling foodborne pathogens are traditionally carried out by conventional microbiological methods based on culture-dependent approaches in control laboratories and private companies. However, polymerase chain reaction (PCR has revolutionized microbiological analysis allowing detection of pathogenic microorganisms in food, without the necessity of classical isolation and identification. However, at present, PCR and quantitative polymerase chain reaction (qPCR are essential analytical tools for researchers working in the field of foodborne pathogens. This manuscript reviews recently described qPCR methods applied for foodborne bacteria detection, serving as economical, safe, and reliable alternatives for application in the food industry and control laboratories. Multiplex qPCR, which allows the simultaneous detection of more than one pathogen in one single reaction, saving considerable effort, time, and money, is emphasized in the article.

Evolutionary biology of bacterial and fungal pathogens

National Research Council Canada - National Science Library

Baquero, F

2008-01-01

... and Evolutionary Dynamics of Pathogens * 21 Keith A. Crandall and Marcos Pérez-Losada II. Evolutionary Genetics of Microbial Pathogens 4. Environmental and Social Influences on Infectious Disea...

Different types of stainless steel used in equipment in meat plants do not affect the initial microbial transfer, including pathogens, from pork skin.

Science.gov (United States)

Larivière-Gauthier, Guillaume; Quessy, Sylvain; Fournaise, Sylvain; Letellier, Ann; Fravalo, Philippe

2015-07-01

This study describes and measures the impact of different compositions and finishes of stainless steel used in equipment in the meat industry on the transfer of natural flora and selected pathogens from artificially contaminated pork skin. It is known that the adhesion to surfaces of Listeria monocytogenes and Salmonella, 2 pathogens frequently found in contaminated pork meat, depends on the nature and roughness of the surface. Our results show no statistically significant differences in microbial transfer regardless of the types of stainless steel considered, with the highest measured transfer difference being 0.18 log colony-forming units (CFUs)/800 cm(2). Moreover, no differences in total microbial community were observed after transfer on the 5 types of stainless steel using single-strand conformation polymorphism (SSCP). It was concluded that the different characteristics of the stainless steel tested did not affect the initial bacterial transfer in this study.

Screening and evaluation of local bacteria isolated from shellfish as potential probiotics against pathogenic Vibrios.

Science.gov (United States)

Jasmin, M Y; Wagaman, Hazimah; Yin, Tan Ai; Ina-salwany, M Y; Daud, H M; Karim, Murni

2016-07-01

The present study was carried out to isolate, screen and evaluate potential candidates of local bacteria isolated from tiger shrimp Penaeus monodon and slipper cupped oysters Crassostrea iredalei as probiotics in shellfish aquaculture. A total of 144 of bacteria were successfully isolated from the intestine and stomach of 20 tails of healthy adult tiger shrimp P. monodon, while 136 were successfully isolated from the digestive tract, gills and inner shells of 10 healthy adult C. iredalei. The number of potential isolates was narrowed down to two from tiger shrimp, and one from slipper cupped oyster after in vitro screening assays. The three isolates, labeled as G11, I24 and S66, were identified as Virgibacillus sp., Bacillus sp. and Exiquobacterium sp., respectively, using 16S rDNA gene analysis. The antagonistic ability of the isolates towards Vibrio alginolyticus and Vibrio harveyi were conducted in stagnant and liquid modes via spot lawn and broth co-culture assay, respectively. In these assays, all the potential probionts were inhibitory to both pathogenic vibrios. In the in-vivo assay, Artemia was used as host and treated with different concentrations of potential probionts (10(4), 10(6) and 10(8) CFU ml(-1)), and challenged with V. alginolyticus and V. harveyi at 105 CFU ml(-1), respectively. Artemia treated with probiont G11 at all concentrations and challenged with V. alginolyticus had increased survival (70 ? 80 %), which was significantly higher as compared with group with only the pathogen (20 %). Meanwhile, probiont I24 increased the survival of Artemia by 70 % at a concentration of 10(8) CFU ml(-1) after being challenged with V. alginolyticus and Artemia treated with 10(6) CFU ml(-1) of probiont S66 had increased survival of 90% after being challenged with V. harveyi. Thus, the three isolates might have potential applications as probiotics in shellfish aquaculture against vibriosis. ?

Exploitation of microbial antagonists for the control of postharvest diseases of fruits: a review.

Science.gov (United States)

Dukare, Ajinath Shridhar; Paul, Sangeeta; Nambi, V Eyarkai; Gupta, Ram Kishore; Singh, Rajbir; Sharma, Kalyani; Vishwakarma, Rajesh Kumar

2018-01-16

Fungal diseases result in significant losses of fruits and vegetables during handling, transportation and storage. At present, post-production fungal spoilage is predominantly controlled by using synthetic fungicides. Under the global climate change scenario and with the need for sustainable agriculture, biological control methods of fungal diseases, using antagonistic microorganisms, are emerging as ecofriendly alternatives to the use of fungicides. The potential of microbial antagonists, isolated from a diversity of natural habitats, for postharvest disease suppression has been investigated. Postharvest biocontrol systems involve tripartite interaction between microbial antagonists, the pathogen and the host, affected by environmental conditions. Several modes for fungistatic activities of microbial antagonists have been suggested, including competition for nutrients and space, mycoparasitism, secretion of antifungal antibiotics and volatile metabolites and induction of host resistance. Postharvest application of microbial antagonists is more successful for efficient disease control in comparison to pre-harvest application. Attempts have also been made to improve the overall efficacy of antagonists by combining them with different physical and chemical substances and methods. Globally, many microbe-based biocontrol products have been developed and registered for commercial use. The present review provides a brief overview on the use of microbial antagonists as postharvest biocontrol agents and summarises information on their isolation, mechanisms of action, application methods, efficacy enhancement, product formulation and commercialisation.

How microbial community composition regulates coral disease development.

Directory of Open Access Journals (Sweden)

Justin Mao-Jones

2010-03-01

Full Text Available Reef coral cover is in rapid decline worldwide, in part due to bleaching (expulsion of photosynthetic symbionts and outbreaks of infectious disease. One important factor associated with bleaching and in disease transmission is a shift in the composition of the microbial community in the mucus layer surrounding the coral: the resident microbial community-which is critical to the healthy functioning of the coral holobiont-is replaced by pathogenic microbes, often species of Vibrio. In this paper we develop computational models for microbial community dynamics in the mucus layer in order to understand how the surface microbial community responds to changes in environmental conditions, and under what circumstances it becomes vulnerable to overgrowth by pathogens. Some of our model's assumptions and parameter values are based on Vibrio spp. as a model system for other established and emerging coral pathogens. We find that the pattern of interactions in the surface microbial community facilitates the existence of alternate stable states, one dominated by antibiotic-producing beneficial microbes and the other pathogen-dominated. A shift to pathogen dominance under transient stressful conditions, such as a brief warming spell, may persist long after environmental conditions have returned to normal. This prediction is consistent with experimental findings that antibiotic properties of Acropora palmata mucus did not return to normal long after temperatures had fallen. Long-term loss of antibiotic activity eliminates a critical component in coral defense against disease, giving pathogens an extended opportunity to infect and spread within the host, elevating the risk of coral bleaching, disease, and mortality.

How microbial community composition regulates coral disease development.

Science.gov (United States)

Mao-Jones, Justin; Ritchie, Kim B; Jones, Laura E; Ellner, Stephen P

2010-03-30

Reef coral cover is in rapid decline worldwide, in part due to bleaching (expulsion of photosynthetic symbionts) and outbreaks of infectious disease. One important factor associated with bleaching and in disease transmission is a shift in the composition of the microbial community in the mucus layer surrounding the coral: the resident microbial community-which is critical to the healthy functioning of the coral holobiont-is replaced by pathogenic microbes, often species of Vibrio. In this paper we develop computational models for microbial community dynamics in the mucus layer in order to understand how the surface microbial community responds to changes in environmental conditions, and under what circumstances it becomes vulnerable to overgrowth by pathogens. Some of our model's assumptions and parameter values are based on Vibrio spp. as a model system for other established and emerging coral pathogens. We find that the pattern of interactions in the surface microbial community facilitates the existence of alternate stable states, one dominated by antibiotic-producing beneficial microbes and the other pathogen-dominated. A shift to pathogen dominance under transient stressful conditions, such as a brief warming spell, may persist long after environmental conditions have returned to normal. This prediction is consistent with experimental findings that antibiotic properties of Acropora palmata mucus did not return to normal long after temperatures had fallen. Long-term loss of antibiotic activity eliminates a critical component in coral defense against disease, giving pathogens an extended opportunity to infect and spread within the host, elevating the risk of coral bleaching, disease, and mortality.

Microbial burden of some herbal antimalarials marketed at Elele, Rivers State.

Science.gov (United States)

Tatfeng, Y M; Olama, E H; Ojo, T O

2009-12-30

Herbal antimalarials still remain an alternative to our traditional communities who can not afford orthodox antimalarials. This study was aimed at investigating the microbial quality of six herbal antimalarials using standard microbiological methods. Of the six preparations analyzed, "schnapps", palm wine and water were the media of preparation; the water base preparations recorded higher microbial load. The mean microbial load was 159.5 × 10(5) cfu/ml and 217.4 × 10(2)cfu/ml in water and alcohol base preparations respectively. The microbial profile of the preparations showed that the schnapps base preparations were predominantly contaminated with Bacillus sp (Aerobic spore bearers) and Mucor spp. The palm wine preparation harboured Bacillus sp, yeasts and Mucor spp while the water base preparations had several isolates such as Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli 0157H7, Proteus mirabilis, Enterococcus feacalis, Serratia marcensces, Staph. aureus, Bacillus spp and Mucor spp. Conclusively, this study underlines the public health importance of these preparations given the high burden of such human pathogen as Ecoli O157H7, Ps aeruginosa, Stahp aureus, etc. in the preparations.

Pathogenicity and molecular detection of Uruguayan isolates of Greeneria uvicola and Cadophora luteo-olivacea associated with grapevine trunk diseases

Directory of Open Access Journals (Sweden)

Fernando NAVARRETE

2011-12-01

Full Text Available Normal 0 21 MicrosoftInternetExplorer4 Species from different fungal genera have been indicated as responsible for the development of trunk diseases of grapevines. Greeneria uvicola is responsible for the bitter rot of Vitis vinifera grape bunchesnear harvest, and can also attack other Vitis species. In Uruguay, G. uvicola was isolated from dead arm affected grapevines and as an endophyte from healthy canes. Cadophora luteo-olivacea is a phialophora-likeascomycete with a wide distribution that was isolated from asymptomatic wood tissues in Vitis and Petridisease-affected nursery plants in Uruguay. Pathogenicity of isolates of both species was evaluated on Vitis vinifera cv. Tannat and Cabernet Sauvignon, and rootstocks SO4 and 3309C. Specific primers were developed for the ITS rDNA region for both species. Number of plants showing discoloration, length of discoloration, number of re-isolations and amplifications confirmed the pathogenicity of G. uvicola isolates. Pathogenicityof the isolate of C. luteo-olivacea obtained from symptomatic tissues is discussed. Specific primers can be usedto detect the presence of these fungi in asymptomatic tissues.

Interactions of microorganisms isolated from gilthead sea bream, Sparus aurata L., on Vibrio harveyi, a pathogen of farmed Senegalese sole, Solea senegalensis (Kaup).

Science.gov (United States)

Chabrillón, M; Rico, R M; Arijo, S; Díaz-Rosales, P; Balebona, M C; Moriñigo, M A

2005-09-01

Four bacterial isolates from farmed gilthead sea bream, Sparus aurata, included in a previous study as members of the Vibrionaceae and Pseudomonodaceae and the genus Micrococcus, have been evaluated for their adhesive ability to skin and intestinal mucus of farmed Senegalese sole, Solea senegalensis, and their antagonistic effect on Vibrio harveyi, a pathogen of sole. These isolates showed higher adhesion to sole mucus than the pathogenic strains of V. harveyi assayed. Only two of the isolates showed antagonistic activity to V. harveyi. Interactions of the four isolates with V. harveyi in respect of adhesion to skin and intestinal mucus under exclusion, competition and displacement conditions were studied. Three isolates were able to reduce the attachment to skin and intestinal sole mucus of a pathogenic strain of V. harveyi under displacement and exclusion conditions, but not under competition conditions. The in vivo probiotic potential of isolate Pdp11 was assessed by oral administration followed by challenge with the pathogenic V. harveyi strain Lg14/00. A group of 50 Senegalese sole received a commercial diet supplemented with 10(8) cfu g(-1) of lyophilized Lg14/00 for 15 days. A second group of fish received a non-supplemented commercial diet. After challenge the mortality of the fish receiving the diet supplemented with the potential probiotic isolate was significantly lower than that in the fish receiving the non-supplemented commercial diet. This study has shown that the ability to interfere with attachment of pathogens, as well as the adhesion to host surfaces, are suitable criteria for selection of candidate probiotics for use in the culture of Senegalese sole.

Isolation and regeneration protoplast of an oil palm pathogen, Ganoderma boninense

Science.gov (United States)

Irene, Liza Isaac; Bakar, Farah Diba Abu; Idris, Abu Seman; Murad, Abdul Munir Abdul

2015-09-01

Ganoderma boninense is a known cause for basal stem rot (BSR) in oil palm. Thus, to curb the infection towards oil palm, the establishment of protoplast isolation and regeneration protocol is crucial to be studied. This will provide information on the functional genes especially those which leads towards infection and pathogenicity. In this study, a method was outlined to isolated protoplast in G. boninense by manipulating parameters such as mycelium age, concentration of lysing enzyme, and duration of mycelia incubation in lytic solution. The results shows that from 0.1 g of wet weight mycelia, the highest protoplast yield obtained was 5.5 × 108 protoplast/ml using 5th day old culture in a lytic mixture containing 2.0 % of lysing enzyme incubated for 4 hours at 30 °C with agitation of 80-100 rpm. The highest percentage of protoplast regeneration obtained from this study was 0.2 % using CYM medium supplemented with 0.6 M sorbitol. To date, this is the first report of protoplast isolation and regeneration for this phytopathogen.

Comparison of keypads and touch-screen mobile phones/devices as potential risk for microbial contamination.

Science.gov (United States)

Koroglu, Mehmet; Gunal, Selami; Yildiz, Fatma; Savas, Mehtap; Ozer, Ali; Altindis, Mustafa

2015-12-30

Touch-screen mobile phones/devices (TMPs/Ds) are increasingly used in hospitals. They may act as a mobile reservoir for microbial pathogens. The rates of microbial contamination of TMPs/Ds and keypad mobile phones (KMPs) with respect to different variables including use by healthcare workers (HCWs)/non-HCWs and the demographic characteristics of users were investigated. A total of 205 mobile phones/devices were screened for microbial contamination: 76 devices belonged to HCWs and 129 devices belonged to the non-HCW group. By rubbing swabs to front screen, back, keypad, and metallic surfaces of devices, 444 samples were collected. Of 205 mobile phones/devices, 143 (97.9%) of the TMPs/Ds and 58 (98.3%) of the KMPs were positive for microbial contamination, and there were no significant differences in contamination rates between these groups, although TMPs/Ds had significantly higher microbial load than KMPs (p mobile phones ≥ 5". Microbial contamination rates increased significantly as phone size increased (p <0.05). Higher numbers of coagulase-negative Staphylococci (CNS) were isolated from KMPs than TMPs/Ds (p = 0.049). The incidence of Enterococcus spp. was higher on the KMPs of HCWs, and methicillin resistant CNS was higher from the TMPs/Ds of non-HCWs (p <0.05). Isolation of CNS, Streptococcus spp. and Escherichia coli was higher from the TMPs/Ds of HCWs (p <0.05). We found no significant difference between TMP/Ds and KMPs in terms of microbial contamination, but TMP/Ds harboured more colonies and total microbial counts increased with screen size.

Effects of natural honey on polymicrobial culture of various human pathogens

Science.gov (United States)

Al-Waili, Faiza S.; Akmal, Mohammed; Ali, Amjed; Salom, Khelod Y.; Al Ghamdi, Ahmad A.

2012-01-01

Introduction Honey has a wide range of antimicrobial activity. All previous studies have considered honey's effect on a single microbe. The present study investigated activity of honey towards a high dose of single or polymicrobial culture. Material and methods 10 µl specimens of Staphylococcus aureus (S. aureus), Streptococcus pyogenes (S. pyogenes), Escherichia coli (E. coli) and Candida albicans (C. albicans) were cultured in 10 ml of 10-100% (wt/v) honey diluted in broth. Six types of polymicrobial microbial cultures were prepared by culturing the isolates with each other onto broth (control) and broth containing various concentrations of honey (10-100% wt/v). Microbial growth was assessed on solid plate media after 24 h incubation. Results Honey (30-70%) prevents growth of 10 µl specimens of all the isolates. Greater reduction in growth of E. coli was observed when cultured with S. aureus. Culturing of S. aureus with S. pyogenes, C. albicans, or E. coli increased its sensitivity to honey. S. aureus and S. pyogenes increased sensitivity of C. albicans to honey while E. coli and C. albicans decreased sensitivity of S. pyogenes. Conclusions It might be concluded that honey prevents and inhibits growth of single and polymicrobial pathogenic cultures. Polymicrobial culture affects growth of the isolates and increases their sensitivity to honey. PMID:24904656

Peracetic Acid (PAA Disinfection: Inactivation of Microbial Indicators and Pathogenic Bacteria in a Municipal Wastewater Plant

Directory of Open Access Journals (Sweden)

Silvia Bonetta

2017-06-01

Full Text Available Several studies have noted that treated and untreated wastewaters are primary contributors of a variety of pathogenic microorganisms to the aquatic ecosystem. Conventional wastewater treatment may not be sufficient to achieve microbiologically safe effluent to be discharged into natural waters or reused, thus requiring wastewater effluents to be disinfected. In recent years, peracetic acid (PAA has been adopted as a disinfectant for wastewater effluents. The aim of this study was to evaluate the disinfection efficiency of PAA at low doses (range 0.99–2.10 mg/L against microbial indicators and pathogenic bacteria in a municipal wastewater plant. Samples of untreated sewage and effluents before and after PAA treatment were collected seasonally for 1 year and were analysed for pathogenic Campylobacter, Salmonella spp., E. coli O157:H7 and E. coli virulence genes using molecular methods; moreover, the detection of specific microbial indicators (E. coli, faecal coliforms, enterococci, C. perfringens and Salmonella spp. were carried out using culturing methods. Salmonella spp. DNA was found in all untreated sewage and effluent before PAA treatment, whereas it was recovered in 50% of the samples collected after PAA treatment. Although E. coli O157:H7 was never identified, the occurrence of Shiga-like toxin I amplicons was identified in 75% of the untreated sewage samples, in 50% of the effluents assayed before PAA treatment, and in 25% of the effluents assayed after PAA treatment, whereas the stx2 gene was never found. Campylobacter coli was only detected in one effluent sample before PAA treatment. In the effluents after PAA treatment, a lower load of indicator bacteria was observed compared to the effluents before treatment. The results of this study highlight that the use of low doses of PAA seems to lead to an improvement of the microbiological quality of the effluent, although it is not sufficient to guarantee its suitability for irrigation

Characterization of multiple antibiotic resistance of culturable microorganisms and metagenomic analysis of total microbial diversity of marine fish sold in retail shops in Mumbai, India.

Science.gov (United States)

Naik, Onkar A; Shashidhar, Ravindranath; Rath, Devashish; Bandekar, Jayant R; Rath, Archana

2018-03-01

Marine fish species were analyzed for culturable and total metagenomic microbial diversity, antibiotic resistance (AR) pattern, and horizontal gene transfer in culturable microorganisms. We observed a high AR microbial load of 3 to 4 log CFU g -1 . Many fish pathogens like Providencia, Staphylococcus, Klebsiella pneumoniae, Enterobacter, Vagococcus, and Aeromonas veronii were isolated. Photobacterium and Vibrio were two major fish and human pathogens which were identified in the fish metagenome. Other pathogens that were identified were Shewanella, Acinetobacter, Psychrobacter, and Flavobacterium. Most of these pathogens were resistant to multiple antibiotics such as erythromycin, kanamycin, neomycin, streptomycin, penicillin, cefotaxime, bacitracin, rifampicin, trimethoprim, ciprofloxacin, and doxycycline with a high multiple antibiotic resistance index of 0.54-0.77. The fish microflora showed high prevalence of AR genes like bla TEM , Class I integron, tetA, aph(3')-IIIa, ermB, aadA, and sul1. Nineteen of 26 AR isolates harbored Class I integrons showing high co-resistance to trimethoprim, kanamycin, doxycycline, and cefotaxime. Mobile R-plasmids from 6 of the 12 AR pathogens were transferred to recipient E. coli after conjugation. The transconjugants harbored the same R-plasmid carrying bla CTX-M , dfr1, tetA, bla TEM , and cat genes. This study confirms that fish is a potential carrier of AR pathogens which can enter the human gut via food chain. To the best of our knowledge, this is the first study in the Indian subcontinent reporting a direct evidence of spread of AR pathogens to humans from specific marine fish consumption.

Draft genome sequences of two opportunistic pathogenic strains of Staphylococcus cohnii isolated from human patients

OpenAIRE

Mendoza-Olazar?n, Soraya; Garcia-Mazcorro, Jos? F.; Morf?n-Otero, Rayo; Villarreal-Trevi?o, Licet; Camacho-Ortiz, Adri?n; Rodr?guez-Noriega, Eduardo; Bocanegra-Ibarias, Paola; Maldonado-Garza, H?ctor J.; Dowd, Scot E.; Garza-Gonz?lez, Elvira

2017-01-01

Herein, we report the draft-genome sequences and annotation of two opportunistic pathogenic strains of Staphylococcus cohnii isolated from humans. One strain (SC-57) was isolated from blood from a male patient in May 2006 and the other (SC-532) from a catheter from a male patient in June 2006. Similar to other genomes of Staphylococcus species, most genes (42%) of both strains are involved in metabolism of amino acids and derivatives, carbohydrates and proteins. Eighty (4%) genes are involved...

Comparative genome analysis of pathogenic and non-pathogenic Clavibacter strains reveals adaptations to their lifestyle

OpenAIRE

Załuga, Joanna; Stragier, Pieter; Baeyen, Steve; Haegeman, Annelies; Van Vaerenbergh, Johan; Maes, Martine; De Vos, Paul

2014-01-01

Background The genus Clavibacter harbors economically important plant pathogens infecting agricultural crops such as potato and tomato. Although the vast majority of Clavibacter strains are pathogenic, there is an increasing number of non-pathogenic isolates reported. Non-pathogenic Clavibacter strains isolated from tomato seeds are particularly problematic because they affect the current detection and identification tests for Clavibacter michiganensis subsp. michiganensis (Cmm), which is reg...

FishPathogens.eu/vhsv: a user-friendly viral haemorrhagic septicaemia virus isolate and sequence database

DEFF Research Database (Denmark)

Jonstrup, Søren Peter; Gray, Tanya; Kahns, Søren

2009-01-01

A database has been created, http://www.Fish Pathogens.eu, with the aim of providing a single repository for collating important information on significant pathogens of aquaculture, relevant to their control and management. This database will be developed, maintained and managed as part of the Eu......A database has been created, http://www.Fish Pathogens.eu, with the aim of providing a single repository for collating important information on significant pathogens of aquaculture, relevant to their control and management. This database will be developed, maintained and managed as part...... of the European Community Reference Laboratory for Fish Diseases function. This concept has been initially developed for viral haemorrhagic septicaemia virus and will be extended in future to include information on other significant aquaculture pathogens. Information included for each isolate comprises sequence...... to obtain data from any selected part of the genome of interest. The output of the sequence search can be readily retrieved as a FASTA file ready to be imported into a sequence alignment tool of choice, facilitating further molecular epidemiological study....

Host range of an NPV and a GV isolated from the common cutworm, Agrotis segetum: pathogenicity within the cutworm complex

NARCIS (Netherlands)

Bourner, T.C.; Cory, J.S.

2004-01-01

The term cutworm covers a range of species with a similar life history that can be very damaging pests on a wide range of crops. Attacks by cutworms are often made up of more than one species; thus, the most cost effective microbial control agent needs to be pathogenic for multiple species within

The worm has turned--microbial virulence modeled in Caenorhabditis elegans.

Science.gov (United States)

Sifri, Costi D; Begun, Jakob; Ausubel, Frederick M

2005-03-01

The nematode Caenorhabditis elegans is emerging as a facile and economical model host for the study of evolutionarily conserved mechanisms of microbial pathogenesis and innate immunity. A rapidly growing number of human and animal microbial pathogens have been shown to injure and kill nematodes. In many cases, microbial genes known to be important for full virulence in mammalian models have been shown to be similarly required for maximum pathogenicity in nematodes. C. elegans has been used in mutation-based screening systems to identify novel virulence-related microbial genes and immune-related host genes, many of which have been validated in mammalian models of disease. C. elegans-based pathogenesis systems hold the potential to simultaneously explore the molecular genetic determinants of both pathogen virulence and host defense.

Microbial enhanced heavy crude oil recovery through biodegradation using bacterial isolates from an Omani oil field.

Science.gov (United States)

Al-Sayegh, Abdullah; Al-Wahaibi, Yahya; Al-Bahry, Saif; Elshafie, Abdulkadir; Al-Bemani, Ali; Joshi, Sanket

2015-09-16

Biodegradation is a cheap and environmentally friendly process that could breakdown and utilizes heavy crude oil (HCO) resources. Numerous bacteria are able to grow using hydrocarbons as a carbon source; however, bacteria that are able to grow using HCO hydrocarbons are limited. In this study, HCO degrading bacteria were isolated from an Omani heavy crude oil field. They were then identified and assessed for their biodegradation and biotransformation abilities under aerobic and anaerobic conditions. Bacteria were grown in five different minimum salts media. The isolates were identified by MALDI biotyper and 16S rRNA sequencing. The nucleotide sequences were submitted to GenBank (NCBI) database. The bacteria were identified as Bacillus subtilis and B. licheniformis. To assess microbial growth and biodegradation of HCO by well-assay on agar plates, samples were collected at different intervals. The HCO biodegradation and biotransformation were determined using GC-FID, which showed direct correlation of microbial growth with an increased biotransformation of light hydrocarbons (C12 and C14). Among the isolates, B. licheniformis AS5 was the most efficient isolate in biodegradation and biotransformation of the HCO. Therefore, isolate AS5 was used for heavy crude oil recovery experiments, in core flooding experiments using Berea core plugs, where an additional 16 % of oil initially in place was recovered. This is the first report from Oman for bacteria isolated from an oil field that were able to degrade and transform HCO to lighter components, illustrating the potential use in HCO recovery. The data suggested that biodegradation and biotransformation processes may lead to additional oil recovery from heavy oil fields, if bacteria are grown in suitable medium under optimum growth conditions.

The importance of virulence prediction and gene networks in microbial risk assessment

DEFF Research Database (Denmark)

Wassenaar, Gertrude Maria; Gamieldien, Junaid; Shatkin, JoAnne

2007-01-01

For microbial risk assessment, it is necessary to recognize and predict Virulence of bacterial pathogens, including their ability to contaminate foods. Hazard characterization requires data on strain variability regarding virulence and survival during food processing. Moreover, information...... and characterization of microbial hazards, including emerging pathogens, in the context of microbial risk assessment....

The efficacy of different anti-microbial metals at preventing the formation of, and eradicating bacterial biofilms of pathogenic indicator strains.

Science.gov (United States)

Gugala, Natalie; Lemire, Joe A; Turner, Raymond J

2017-06-01

The emergence of multidrug-resistant pathogens and the prevalence of biofilm-related infections have generated a demand for alternative anti-microbial therapies. Metals have not been explored in adequate detail for their capacity to combat infectious disease. Metal compounds can now be found in textiles, medical devices and disinfectants-yet, we know little about their efficacy against specific pathogens. To help fill this knowledge gap, we report on the anti-microbial and antibiofilm activity of seven metals: silver, copper, titanium, gallium, nickel, aluminum and zinc against three bacterial strains, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. To evaluate the capacity of metal ions to prevent the growth of, and eradicate biofilms and planktonic cells, bacterial cultures were inoculated in the Calgary Biofilm Device (minimal biofilm eradication concentration) in the presence of the metal salts. Copper, gallium and titanium were capable of preventing planktonic and biofilm growth, and eradicating established biofilms of all tested strains. Further, we observed that the efficacies of the other tested metal salts displayed variable efficacy against the tested strains. Further, contrary to the enhanced resistance anticipated from bacterial biofilms, particular metal salts were observed to be more effective against biofilm communities versus planktonic cells. In this study, we have demonstrated that the identity of the bacterial strain must be considered before treatment with a particular metal ion. Consequent to the use of metal ions as anti-microbial agents to fight multidrug-resistant and biofilm-related infections increases, we must aim for more selective deployment in a given infectious setting.

PanCoreGen - Profiling, detecting, annotating protein-coding genes in microbial genomes.

Science.gov (United States)

Paul, Sandip; Bhardwaj, Archana; Bag, Sumit K; Sokurenko, Evgeni V; Chattopadhyay, Sujay

2015-12-01

A large amount of genomic data, especially from multiple isolates of a single species, has opened new vistas for microbial genomics analysis. Analyzing the pan-genome (i.e. the sum of genetic repertoire) of microbial species is crucial in understanding the dynamics of molecular evolution, where virulence evolution is of major interest. Here we present PanCoreGen - a standalone application for pan- and core-genomic profiling of microbial protein-coding genes. PanCoreGen overcomes key limitations of the existing pan-genomic analysis tools, and develops an integrated annotation-structure for a species-specific pan-genomic profile. It provides important new features for annotating draft genomes/contigs and detecting unidentified genes in annotated genomes. It also generates user-defined group-specific datasets within the pan-genome. Interestingly, analyzing an example-set of Salmonella genomes, we detect potential footprints of adaptive convergence of horizontally transferred genes in two human-restricted pathogenic serovars - Typhi and Paratyphi A. Overall, PanCoreGen represents a state-of-the-art tool for microbial phylogenomics and pathogenomics study. Copyright © 2015 Elsevier Inc. All rights reserved.

MICROBIAL STATUS OF DONKEY’S MILK: FIRST RESULTS

Directory of Open Access Journals (Sweden)

L. Alberghini

2012-08-01

Full Text Available For its chemical and nutritional composition donkey milk is an excellent substitute for human breast milk. In fact, woman’s milk and donkey one are quite similar for their composition and for certain intrinsic properties. Based on these considerations, we performed a study on the microbiological characteristics of 86 jannet’s milk in 10 farms. Special attention was given to the aspects of health quality of the milk samples examined, referring to the analysis of total microbial count and pH, the possible presence of potentially pathogenic micro-organisms, especially by seeking the bacteria Escherichia coli O157, Salmonella spp., Listeria monocytogenes and Campylobacter spp. The samples of milk were picked up from January to March 2010. Our research showed a situation quite positive in terms of sanitation, finding levels of total microbial count (on average 1,8·104 cfu/ml and pH (mean 7,02 entirely in line with data found in previous investigations of other Authors and with values reassuring in terms of healthiness of the product. Regarding the detection of potentially pathogenic microorganisms, only a milk sample of 86 tested was positive for E. coli O157; in an other sample low charges of Campylobacter spp. have been measured. Salmonella spp. and Listeria monocytogenes were not found in all samples. Total microbial count confirm the good quality of the donkey milk. However, occasional isolation of E. coli O157 and Campylobacter spp. suggests careful attention is to be done to the correct procedures of milking hygiene.

Comparative pathogenicity of Vibrio spp., Photobacterium damselae ssp. damselae and five isolates of Aeromonas salmonicida ssp. achromogenes in juvenile Atlantic halibut (Hippoglossus hippoglossus).

Science.gov (United States)

Bowden, T J; Bricknell, I R; Preziosi, B M

2018-01-01

Juvenile Atlantic halibut (~100 mg, Hippoglossus hippoglossus) were exposed to Vibrio proteolyticus, a Vibrio spp. isolate, Photobacterium damselae ssp. damselae and five different isolates of Aeromonas salmonicida ssp. achromogenes via an hour-long bath immersion to ascertain their variation in pathogenicity to this fish species. Results were analysed using Kaplan-Meier survival analysis. Analysis of the data from challenges using A. salmonicida ssp. achromogenes revealed three survival values of zero and a spread of values from 0 to 28.43. Challenges using a Vibrio spp isolate, V. proteolyticus and P. damselae resulted in Kaplan-Meier survival estimates of 31.21, 50.41 and 57.21, respectively. As all bacterial species tested could induce juvenile halibut mortalities, they must all be considered as potential pathogens. However, the degree of pathogenicity of A. salmonicida is isolate dependent. © 2017 John Wiley & Sons Ltd.

Isolation and characterization of virus of highly pathogenic avian influenza H5 subtype of chicken from outbreaks in Indonesia

Directory of Open Access Journals (Sweden)

Agus Wiyono

2004-03-01

Full Text Available A study on the isolation and characterization of Highly Pathogenic Avian Influenza of chicken from outbreaks in Indonesia was conducted at Indonesian Research Institute for Veterinary Science. Outbreaks of avian disease had been reported in Indonesia since August 2003 affecting commercial layer, broiler, quail, and ostrich and also native chicken with showing clinical signs such as cyanosis of wattle and comb, nasal discharges and hypersalivation, subcutaneous ptechiae on foot and leg, diarre and sudden high mortality. The aim of this study is to isolate and characterize the causal agent of the disease. Samples of serum, feather follicle, tracheal swab, as well as organs of proventriculus, intestine, caecal tonsil, trachea and lungs were collected from infected animals. Serum samples were tested haemaglutination/haemaglutination inhibition to Newcastle Disease and Egg Drop Syndrome viruses. Isolation of virus of the causal agent of the outbreak was conducted from samples of feather follicle, tracheal swab, and organs using 11 days old specific pathogen free (SPF embryonated eggs. The isolated viruses were then characterised by agar gel precipitation test using swine influenza reference antisera, by haemaglutination inhibition using H1 to H15 reference antisera, and by electron microscope examination. The pathogenicity of the viruses was confirmed by intravenous pathogenicity index test and its culture in Chicken Embryo Fibroblast primary cell culture without addition of trypsin. The study revealed that the causative agent of the outbreaks of avian disease in Indonesia was avian influenza H5 subtype virus based upon serological tests, virus isolation and characterization using swine influenza reference antisera, and electron microscope examination. While subtyping of the viruses using H1 to H15 reference antisera suggested that the virus is very likely to be an avian influenza H5N1 subtype virus. The pathogenicity test confirmed that the viruses

Isolation and pathogenicity of Xylella fastidiosa from grapevine and almond in Iran

Directory of Open Access Journals (Sweden)

Naser AMANIFAR

2014-09-01

Full Text Available Symptoms similar to those of Pierce’s disease (PD of grapevine and leaf scorch of almond were observed in vineyards and almond orchards in several provinces of Iran. Grafting of scions from symptomatic almond trees onto seedlings of a local almond (cv. Mamaee under greenhouse conditions resulted in the transmission of the leaf scorch agent. A number of symptomatic samples from orchard and greenhouse plants were positive for presence of Xylella fastidiosa when tested by DAS-ELISA and PCR with X. fastidiosa specific antibodies and primers. A Gram-negative bacterium similar to X. fastidiosa was isolated on ‘periwinkle wilt’ (PW medium. Selected isolates induced symptoms similar to those caused by X. fastidiosa when inoculated on Nicotiana tabacum, seedlings of almond and grapevine under greenhouse conditions. DAS-ELISA and PCR confirmed the identity of the isolated bacteria. On the basis of disease symptoms, graft transmission, isolation on specific X. fastidiosa culture medium, pathogenicity tests and positive reactions in DAS-ELISA and PCR, X. fastidiosa is associated with almond leaf scorch and Pierce’s disease in grapevine in Iran. This is the first report on the presence of X. fastidiosa in the Middle East and western Asia.

The potential pathogenicity of chlorhexidine-sensitive Acanthamoeba strains isolated from contact lens cases from asymptomatic individuals in Tenerife, Canary Islands, Spain.

Science.gov (United States)

Martín-Navarro, Carmen M; Lorenzo-Morales, Jacob; Cabrera-Serra, M Gabriela; Rancel, Fernando; Coronado-Alvarez, Nieves M; Piñero, José E; Valladares, Basilio

2008-11-01

Pathogenic strains of the genus Acanthamoeba are causative agents of a serious sight-threatening infection of the eye known as Acanthamoeba keratitis. The prevalence of this infection has risen in the past 20 years, mainly due to the increase in number of contact lens wearers. In this study, the prevalence of Acanthamoeba in a risk group constituted by asymptomatic contact lens wearers from Tenerife, Canary Islands, Spain, was evaluated. Contact lenses and contact lens cases were analysed for the presence of Acanthamoeba isolates. The isolates' genotypes were also determined after rDNA sequencing. The pathogenic potential of the isolated strains was subsequently established using previously described molecular and biochemical assays, which allowed the selection of three strains with high pathogenic potential. Furthermore, the sensitivity of these isolates against two standard drugs, ciprofloxacin and chlorhexidine, was analysed. As the three selected strains were sensitive to chlorhexidine, its activity and IC(50) were evaluated. Chlorhexidine was found to be active against these strains and the obtained IC(50) values were compared to the concentrations of this drug present in contact lens maintenance solutions. It was observed that the measured IC(50) was higher than the concentration found in these maintenance solutions. Therefore, the ineffectiveness of chlorhexidine-containing contact lens maintenance solutions against potentially pathogenic strains of Acanthamoeba is demonstrated in this study.

Microbial contamination level of air in animal waste utilization plants.

Science.gov (United States)

Chmielowiec-Korzeniowska, Anna; Tymczyna, Leszek; Drabik, Agata; Krzosek, Łukasz

2016-01-01

The aim of this research was evaluation of microbial contamination of air within and in the vicinity of animal waste disposal plants. Air samples were analyzed to determine total bacterial and fungal counts as well as microbial species composition. Measurements of climate conditions (temperature, humidity, air motion) and total dust concentration were also performed. Total numbers of bacteria and fungi surpassed the threshold limit values for production halls. The most abundant bacteria detected were those consisting of physiological microflora of animal dermis and mucosa. Fungal species composition proved to be most differentiated in the air beyond the plant area. Aspergillus versicolor, a pathogenic and allergenic filamentous fungus, was isolated only inside the rendering plant processing hall. The measurement results showed a low sanitary-hygienic state of air in the plant processing halls and substantial air pollution in its immediate vicinity.

Pathogenicity of Salmonella Strains Isolated from Egg Shells and the Layer Farm Environment in Australia

Science.gov (United States)

McWhorter, Andrea R.; Davos, Dianne

2014-01-01

In Australia, the egg industry is periodically implicated during outbreaks of Salmonella food poisoning. Salmonella enterica serovar Typhimurium and other nontyphoidal Salmonella spp., in particular, are a major concern for Australian public health. Several definitive types of Salmonella Typhimurium strains, but primarily Salmonella Typhimurium definitive type 9 (DT9), have been frequently reported during egg-related food poisoning outbreaks in Australia. The aim of the present study was to generate a pathogenicity profile of nontyphoidal Salmonella isolates obtained from Australian egg farms. To achieve this, we assessed the capacity of Salmonella isolates to cause gastrointestinal disease using both in vitro and in vivo model systems. Data from in vitro experiments demonstrated that the invasion capacity of Salmonella serovars cultured to stationary phase (liquid phase) in LB medium was between 90- and 300-fold higher than bacterial suspensions in normal saline (cultured in solid phase). During the in vivo infection trial, clinical signs of infection and mortality were observed only for mice infected with either 103 or 105 CFU of S. Typhimurium DT9. No mortality was observed for mice infected with Salmonella serovars with medium or low invasive capacity in Caco-2 cells. Pathogenicity gene profiles were also generated for all serovars included in this study. The majority of serovars tested were positive for selected virulence genes. No relationship between the presence or absence of virulence genes by PCR and either in vitro invasive capacity or in vivo pathogenicity was detected. Our data expand the knowledge of strain-to-strain variation in the pathogenicity of Australian egg industry-related Salmonella spp. PMID:25362057

Antimicrobial Activity of Carbon Nanoparticles Isolated from Natural Sources against Pathogenic Gram-Negative and Gram-Positive Bacteria

International Nuclear Information System (INIS)

Varghese, S.; Jose, S.; Varghese, S.; Kuriakose, S.; Jose, S.

2013-01-01

This paper describes the isolation of carbon nanoparticles (CNPs) from kitchen soot, characterization of the CNPs by UV/visible spectroscopy, SEM and XRD, and their antimicrobial action. The antibacterial activity of the isolated carbon nanoparticles was tested against various pathogenic bacterial strains such as Gram-negative Proteus refrigere and Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus and Streptococcus haemolyticus. The inhibition zones were measured, and it was found that the carbon nanoparticles isolated from natural sources are active against these Gram-negative and Gram-positive bacterial strains

Microbial Carriage of Cockroaches at a Tertiary Care Hospital in Ghana

Directory of Open Access Journals (Sweden)

Patience B. Tetteh-Quarcoo

2013-01-01

Full Text Available Cockroaches are common in the environment of many hospitals in Ghana; however, little is known about their public health risks. To evaluate potential risks, we investigated the external and internal microbial flora of 61 cockroaches from a tertiary hospital in Ghana and evaluated the antibiotic resistance profiles of the common bacterial species. Standard methods were used in all the microbiological investigations and antibiotic susceptibility testing. A rotavirus carriage rate of 19.7% was observed among the cockroaches. Four types of intestinal parasites were carried externally by the cockroaches, and the most prevalent was Hookworm (4.9%. Eight nosocomial bacteria were isolated from the cockroaches, and the most prevalent was Klebsiella pneumoniae , which occurred internally in 29.5% of the cockroaches and 26.2% externally. Multiple drug resistance among common bacteria isolated from the cockroaches ranged from 13.8% ( Escherichia coli to 41.1% ( Klebsiella pneumoniae . Cockroaches constitute an important reservoir for pathogenic microorganisms, and may be important vectors of multiple resistant nosocomial pathogens in the studied hospital.

Pathogenicity and Host Range of Pathogen Causing Black Raspberry (Rubus coreanus) Anthracnose in Korea

OpenAIRE

Uh Seong Jeong; Ju Hee Kim; Ki Kwon Lee; Seong Soo Cheong; Wang Hyu Lee

2013-01-01

The strains of Colletotrichum gloeosporioides, C. coccodes, C. acutatum isolated from black raspberry werepathogenic to apple and strawberry after dropping inoculation, but showed weak pathogenicity in hot-pepperand tomato. The anthracnose pathogens of C. gloeosporioides, C. orbiculare, C. acutatum isolated from apple,hot-pepper and pumpkin showed pathogenicity in black raspberry. Moreover, the anthracnose pathogensisolated from apple caused disease symptoms in non-wounded inoculation.

Pattern of pathogens and their sensitivity isolated from superficial surgical site infections in a tertiary care hospital

International Nuclear Information System (INIS)

Ali, S.A.; Tahir, S.M.; Shaikh, N.A.

2009-01-01

Infection is an important cause of morbidity and mortality in surgical patients. Rapidly emerging nosocomial pathogens and the problem of multi-drug resistance necessitates periodic review of isolation patterns and sensitivity in surgical practice. Surgical site infections (SSI) are defined as an infections that occurs at the incision site within thirty days after surgery. Objectives of the study were to determine the pattern of pathogens involved and their antibiotic sensitivity isolated from superficial surgical site infections in a teaching hospital. This observational study was conducted for 1 year from January 2008 to December 2008 in all 4 surgical units of Liaquat University Hospital Hyderabad which caters to patients from low socioeconomic status. Pus culture and sensitivity reports were collected prospectively from hospitalised patients who developed postoperative wound infection. The patients who developed fecal/biliary/urinary fistula or operated for malignancies, and with negative cultures were excluded from the study. Analysis was carried out using SPSS 10. During the study period 112 pus culture and sensitivity reports were analyzed. E. coli 68 (60.7%) was the most common organism isolated followed by Klebsiella 23 (20.5%). The least frequent organism was staph. Epidermidis 1 (0.9%). All isolates were sensitive to penicillin derivatives and carbapenem. Quinolones, Aminoglycosides and Monobactum were also showing some promise in our study. However, Cephalosporins were ineffective against most of the important isolates in our study. E. coli and klebsiella were the most important isolates form SSI in our study, and penicillin derivatives and carbapenem were showing 100% antibiotic sensitivity to all of the isolates. (author)

Identification and Pathogenic Potential of Clinical Bacillus and Paenibacillus Isolates.

Directory of Open Access Journals (Sweden)

Francesco Celandroni

Full Text Available The soil-related Bacillus and Paenibacillus species have increasingly been implicated in various human diseases. Nevertheless, their identification still poses problems in the clinical microbiology laboratory and, with the exception of Bacillus anthracis and Bacillus cereus, little is known on their pathogenicity for humans. In this study, we evaluated the use of matrix-assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS in the identification of clinical isolates of these genera and conducted genotypic and phenotypic analyses to highlight specific virulence properties. Seventy-five clinical isolates were subjected to biochemical and MALDI-TOF MS identification. 16S rDNA sequencing and supplemental tests were used to solve any discrepancies or failures in the identification results. MALDI-TOF MS significantly outperformed classical biochemical testing for correct species identification and no misidentification was obtained. One third of the collected strains belonged to the B. cereus species, but also Bacillus pumilus and Bacillus subtilis were isolated at high rate. Antimicrobial susceptibility testing showed that all the B. cereus, B. licheniformis, B. simplex, B. mycoides, Paenibacillus glucanolyticus and Paenibacillus lautus isolates are resistant to penicillin. The evaluation of toxin/enzyme secretion, toxin-encoding genes, motility, and biofilm formation revealed that B. cereus displays the highest virulence potential. However, although generally considered nonpathogenic, most of the other species were shown to swim, swarm, produce biofilms, and secrete proteases that can have a role in bacterial virulence. In conclusion, MALDI-TOF MS appears useful for fast and accurate identification of Bacillus and Paenibacillus strains whose virulence properties make them of increasing clinical relevance.

The in vitro culture of Phytophthora infestans isolates occurring on the tomato - their pathogenicity and usefulness for artificial inoculations

Directory of Open Access Journals (Sweden)

Elżbieta Horodecka

2013-12-01

Full Text Available In investigations on the fungus, Phytophthora infestans, isolated from open air, field-grown tomatoes, particular attention was paid to the pathogenicity of 32 isolates and the suitability of 10 kinds of natural media. It is concluded that Phytophthora races in Poland have highly varied pathogenicities and that they belong to race 0 or 1. The races were divided into subgroups of various aggressiveness. It was found that the best medium to obtain an inoculum was the agar-oat medium without vitamin B1. Vitamin B1 as well as tomatine added to agar media stimulated growth, but inhibited sporulation of Phytophthora infestans.

Analysis of clinical isolates of Helicobacter pylori in Pakistan reveals high degrees of pathogenicity and high frequencies of antibiotic resistance.

Science.gov (United States)

Rasheed, Faisal; Campbell, Barry James; Alfizah, Hanafiah; Varro, Andrea; Zahra, Rabaab; Yamaoka, Yoshio; Pritchard, David Mark

2014-10-01

Antibiotic resistance in Helicobacter pylori contributes to failure in eradicating the infection and is most often due to point and missense mutations in a few key genes. The antibiotic susceptibility profiles of H. pylori isolates from 46 Pakistani patients were determined by Etest. Resistance and pathogenicity genes were amplified, and sequences were analyzed to determine the presence of mutations. A high percentage of isolates (73.9%) were resistant to metronidazole (MTZ), with considerable resistance to clarithromycin (CLR; 47.8%) and amoxicillin (AML; 54.3%) also observed. Relatively few isolates were resistant to tetracycline (TET; 4.3%) or to ciprofloxacin (CIP; 13%). However, most isolates (n = 43) exhibited resistance to one or more antibiotics. MTZ-resistant isolates contained missense mutations in oxygen-independent NADPH nitroreductase (RdxA; 8 mutations found) and NADH flavin oxidoreductase (FrxA; 4 mutations found). In the 23S rRNA gene, responsible for CLR resistance, a new point mutation (A2181G) and 4 previously reported mutations were identified. Pathogenicity genes cagA, dupA, and vacA s1a/m1 were detected frequently in isolates which were also found to be resistant to MTZ, CLR, and AML. A high percentage of CagA and VacA seropositivity was also observed in these patients. Phylogenetic analysis of partial sequences showed uniform distribution of the 3' region of cagA throughout the tree. We have identified H. pylori isolates in Pakistan which harbor pathogenicity genes and worrying antibiotic resistance profiles as a result of having acquired multiple point and missense mutations. H. pylori eradication regimens should therefore be reevaluated in this setting. © 2014 John Wiley & Sons Ltd.

Microbial profiling of dental plaque from mechanically ventilated patients.

Science.gov (United States)

Sands, Kirsty M; Twigg, Joshua A; Lewis, Michael A O; Wise, Matt P; Marchesi, Julian R; Smith, Ann; Wilson, Melanie J; Williams, David W

2016-02-01

Micro-organisms isolated from the oral cavity may translocate to the lower airways during mechanical ventilation (MV) leading to ventilator-associated pneumonia (VAP). Changes within the dental plaque microbiome during MV have been documented previously, primarily using culture-based techniques. The aim of this study was to use community profiling by high throughput sequencing to comprehensively analyse suggested microbial changes within dental plaque during MV. Bacterial 16S rDNA gene sequences were obtained from 38 samples of dental plaque sampled from 13 mechanically ventilated patients and sequenced using the Illumina platform. Sequences were processed using Mothur, applying a 97% gene similarity cut-off for bacterial species level identifications. A significant 'microbial shift' occurred in the microbial community of dental plaque during MV for nine out of 13 patients. Following extubation, or removal of the endotracheal tube that facilitates ventilation, sampling revealed a decrease in the relative abundance of potential respiratory pathogens and a compositional change towards a more predominantly (in terms of abundance) oral microbiota including Prevotella spp., and streptococci. The results highlight the need to better understand microbial shifts in the oral microbiome in the development of strategies to reduce VAP, and may have implications for the development of other forms of pneumonia such as community-acquired infection.

PanCoreGen – profiling, detecting, annotating protein-coding genes in microbial genomes

Science.gov (United States)

Bhardwaj, Archana; Bag, Sumit K; Sokurenko, Evgeni V.

2015-01-01

A large amount of genomic data, especially from multiple isolates of a single species, has opened new vistas for microbial genomics analysis. Analyzing pan-genome (i.e. the sum of genetic repertoire) of microbial species is crucial in understanding the dynamics of molecular evolution, where virulence evolution is of major interest. Here we present PanCoreGen – a standalone application for pan- and core-genomic profiling of microbial protein-coding genes. PanCoreGen overcomes key limitations of the existing pan-genomic analysis tools, and develops an integrated annotation-structure for species-specific pan-genomic profile. It provides important new features for annotating draft genomes/contigs and detecting unidentified genes in annotated genomes. It also generates user-defined group-specific datasets within the pan-genome. Interestingly, analyzing an example-set of Salmonella genomes, we detect potential footprints of adaptive convergence of horizontally transferred genes in two human-restricted pathogenic serovars – Typhi and Paratyphi A. Overall, PanCoreGen represents a state-of-the-art tool for microbial phylogenomics and pathogenomics study. PMID:26456591

Assessment and impact of microbial fecal pollution and human enteric pathogens in a coastal community.

Science.gov (United States)

Lipp, E K; Farrah, S A; Rose, J B

2001-04-01

The goals of this study were to assess watersheds impacted by high densities of OSDS (onsite sewage disposal systems) for evidence of fecal contamination and evaluate the occurrence of human pathogens in coastal waters off west Florida. Eleven stations (representing six watersheds) were intensively sampled for microbial indicators of fecal pollution (fecal coliform bacteria, enterococci, Clostridium perfringens and coliphage) and the human enteric pathogens, Cryptosporidium, Giardia, and enteroviruses during the summer rainy season (May-September 1996). Levels of all indicators ranged between 4000 CFU/100 ml. Cryptosporidium and Giardia were detected infrequently (6.8% and 2.3% of samples tested positive, respectively). Conversely, infectious enteroviruses were detected at low levels in 5 of the 6 watersheds sampled. Using cluster analysis, sites were grouped into two categories, high and low risks, based on combined levels of indicators. These results suggest that stations of highest pollution risk were located within areas of high OSDS densities. Furthermore, data indicate a subsurface transport of contaminated water to surface waters. The high prevalence of enteroviruses throughout the study area suggests a chronic pollution problem and potential risk to recreational swimmers in and around Sarasota Bay.

Susceptibility to antimicrobial agents among bovine mastitis pathogens isolated from North American dairy cattle, 2002-2010.

Science.gov (United States)

Lindeman, Cynthia J; Portis, Ellen; Johansen, Lacie; Mullins, Lisa M; Stoltman, Gillian A

2013-09-01

Approximately 8,000 isolates of Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Staphylococcus aureus, and Escherichia coli, isolated by 25 veterinary laboratories across North America between 2002 and 2010, were tested for in vitro susceptibility to beta-lactam, macrolide, and lincosamide drugs. The minimal inhibitory concentrations (MICs) of the beta-lactam drugs remained low against most of the Gram-positive strains tested, and no substantial changes in the MIC distributions were seen over time. Of the beta-lactam antimicrobial agents tested, only ceftiofur showed good in vitro activity against E. coli. The MICs of the macrolides and lincosamides also remained low against Gram-positive mastitis pathogens. While the MIC values given by 50% of isolates (MIC50) for erythromycin and pirlimycin and the streptococci were all low (≤0.5 µg/ml), the MIC values given by 90% of isolates (MIC90) were higher and more variable, but with no apparent increase over time. Staphylococcus aureus showed little change in erythromycin susceptibility over time, but there may be a small, numerical increase in pirlimycin MIC50 and MIC90 values. Overall, the results suggest that mastitis pathogens in the United States and Canada have not shown any substantial changes in the in vitro susceptibility to beta-lactam, macrolide, and lincosamide drugs tested over the 9 years of the study.

Detection of catabolic genes in indigenous microbial consortia isolated from a diesel-contaminated soil

International Nuclear Information System (INIS)

Milcic-Terzic, J.; Saval, S.; Lopez-Vidal, Y.; Vrvic, M.M.

2001-01-01

Bioremediation is often used for in situ remediation of petroleum-contaminated sites. The primary focus of this study was on understanding the indigenous microbial community which can survive in contaminated environment and is responsible for the degradation. Diesel, toluene and naphthalene-degrading microbial consortia were isolated from diesel-contaminated soil by growing on selective hydrocarbon substrates. The presence and frequency of the catabolic genes responsible for aromatic hydrocarbon biodegradation (xylE, ndoB) within the isolated consortia were screened using polymerase chain reaction PCR and DNA-DNA colony hybridization. The diesel DNA-extract possessed both the xylE catabolic gene for toluene, and the nah catabolic gene for polynuclear aromatic hydrocarbon degradation. The toluene DNA-extract possessed only the xylE catabolic gene, while the naphthalene DNA-extract only the ndoB gene. Restriction enzyme analysis with HaeIII indicated similar restriction patterns for the xylE gene fragment between toluene DNA-extract and a type strain, Pseudomonas putida ATCC 23973. A substantial proportion (74%) of the colonies from the diesel-consortium possessed the xylE gene, and the ndoB gene (78%), while a minority (29%) of the toluene-consortium harbored the xylE gene. 59% of the colonies from the naphthalene-consortium had the ndoB gene, and did not have the xylE gene. These results indicate that the microbial population has been naturally enriched in organisms carrying genes for aromatic hydrocarbon degradation and that significant aromatic biodegradative potential exists at the site. Characterization of the population genotype constitutes a molecular diagnosis which permits the determination of the catabolic potential of the site to degrade the contaminant present. (author)

Etiology and antimicrobial susceptibility of udder pathogens from cases of subclinical mastitis in dairy cows in Sweden

Directory of Open Access Journals (Sweden)

Nyman Ann-Kristin J

2011-06-01

Full Text Available Abstract Background A nationwide survey on the microbial etiology of cases of subclinical mastitis in dairy cows was carried out on dairy farms in Sweden. The aim was to investigate the microbial panorama and the occurrence of antimicrobial resistance. Moreover, differences between newly infected cows and chronically infected cows were investigated. Methods In total, 583 quarter milk samples were collected from 583 dairy cows at 226 dairy farms from February 2008 to February 2009. The quarter milk samples were bacteriological investigated and scored using the California Mastitis Test. Staphylococci were tested for betalactamase production and presence of resistance was evaluated in all specific udder pathogens. Differences between newly infected cows and chronically infected cows were statistically investigated using logistic regression analysis. Results The most common isolates of 590 bacteriological diagnoses were Staphylococcus (S aureus (19% and coagulase-negative staphylococci (CNS; 16% followed by Streptococcus (Str dysgalactiae (9%, Str. uberis (8%, Escherichia (E. coli (2.9%, and Streptococcus spp. (1.9%. Samples with no growth or contamination constituted 22% and 18% of the diagnoses, respectively. The distribution of the most commonly isolated bacteria considering only bacteriological positive samples were: S. aureus - 31%, CNS - 27%, Str. dysgalactiae - 15%, Str. uberis - 14%, E. coli - 4.8%, and Streptococcus spp. - 3.1%. There was an increased risk of finding S. aureus, Str. uberis or Str. dysgalactiae in milk samples from chronically infected cows compared to findings in milk samples from newly infected cows. Four percent of the S. aureus isolates and 35% of the CNS isolates were resistant to penicillin G. Overall, resistance to other antimicrobials than penicillin G was uncommon. Conclusions Staphylococcus aureus and CNS were the most frequently isolated pathogens and resistance to antimicrobials was rare.

Integrated Detection of Pathogens and Host Biomarkers for Wounds

Energy Technology Data Exchange (ETDEWEB)

Jaing, C

2012-03-19

The increasing incidence and complications arising from combat wounds has necessitated a reassessment of methods for effective treatment. Infection, excessive inflammation, and incidence of drug-resistant organisms all contribute toward negative outcomes for afflicted individuals. The organisms and host processes involved in wound progression, however, are incompletely understood. We therefore set out, using our unique technical resources, to construct a profile of combat wounds which did or did not successfully resolve. We employed the Lawrence Livermore Microbial Detection Array and identified a number of nosocomial pathogens present in wound samples. Some of these identities corresponded with bacterial isolates previously cultured, while others were not obtained via standard microbiology. Further, we optimized proteomics protocols for the identification of host biomarkers indicative of various stages in wound progression. In combination with our pathogen data, our biomarker discovery efforts will provide a profile corresponding to wound complications, and will assist significantly in treatment of these complex cases.

Characterizing relationships among fecal indicator bacteria, microbial source tracking markers, and associated waterborne pathogen occurrence in stream water and sediments in a mixed land use watershed

Science.gov (United States)

Bed sediments of streams and rivers may store high concentrations of fecal indicator bacteria (FIB) and pathogens. Due to resuspension events, these contaminants can be mobilized into the water column and affect overall water quality. Other bacterial indicators such as microbial ...

Draft genome sequences of two opportunistic pathogenic strains of Staphylococcus cohnii isolated from human patients.

Science.gov (United States)

Mendoza-Olazarán, Soraya; Garcia-Mazcorro, José F; Morfín-Otero, Rayo; Villarreal-Treviño, Licet; Camacho-Ortiz, Adrián; Rodríguez-Noriega, Eduardo; Bocanegra-Ibarias, Paola; Maldonado-Garza, Héctor J; Dowd, Scot E; Garza-González, Elvira

2017-01-01

Herein, we report the draft-genome sequences and annotation of two opportunistic pathogenic strains of Staphylococcus cohnii isolated from humans. One strain (SC-57) was isolated from blood from a male patient in May 2006 and the other (SC-532) from a catheter from a male patient in June 2006. Similar to other genomes of Staphylococcus species, most genes (42%) of both strains are involved in metabolism of amino acids and derivatives, carbohydrates and proteins. Eighty (4%) genes are involved in virulence, disease, and defense and both species show phenotypic low biofilm production and evidence of increased antibiotic resistance associated to biofilm production. From both isolates, a new Staphylococcal Cassette Chromosome mec was detected: mec class A, ccr type 1. This is the first report of whole genome sequences of opportunistic S. cohnii isolated from human patients.

Application of MALDI-TOF MS fingerprinting as a quick tool for identification and clustering of foodborne pathogens isolated from food products.

Science.gov (United States)

Elbehiry, Ayman; Marzouk, Eman; Hamada, Mohamed; Al-Dubaib, Musaad; Alyamani, Essam; Moussa, Ihab M; AlRowaidhan, Anhar; Hemeg, Hassan A

2017-10-01

Foodborne pathogens can be associated with a wide variety of food products and it is very important to identify them to supply safe food and prevent foodborne infections. Since traditional techniques are timeconsuming and laborious, this study was designed for rapid identification and clustering of foodborne pathogens isolated from various restaurants in Al-Qassim region, Kingdom of Saudi Arabia (KSA) using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Sixty-nine bacterial and thirty-two fungal isolates isolated from 80 food samples were used in this study. Preliminary identification was carried out through culture and BD Phoenix™ methods. A confirmatory identification technique was then performed using MALDI-TOF MS. The BD Phoenix results revealed that 97% (67/69 isolates) of bacteria were correctly identified as 75% Enterobacter cloacae, 95.45% Campylobacter jejuni and 100% for Escherichia coli, Salmonella enterica, Staphylococcus aureus, Acinetobacter baumannii, and Klebsiella pneumoniae. While 94.44% (29/32 isolates) of fungi were correctly identified as 77.77% Alternaria alternate, 88.88% Aspergillus niger and 100% for Aspergillus flavus, Penicillium digitatum, Candida albicans and Debaryomyces hansenii. However, all bacterial and fungal isolates were 100% properly identified by MALDI-TOF MS fingerprinting with a score value ≥2.00. A gel view illustrated that the spectral peaks for the identified isolates fluctuate between 3,000 and 10,000 Da. The results of main spectra library (MSP) dendrogram showed that the bacterial and fungal isolates matched with 19 and 9 reference strains stored in the Bruker taxonomy, respectively. Our results indicated that MALDI-TOF MS is a promising technique for fast and accurate identification of foodborne pathogens.

Isolation and identification of an extracellular subtilisin-like serine protease secreted by the bat pathogen Pseudogymnoascus destructans.

Directory of Open Access Journals (Sweden)

Evan L Pannkuk

Full Text Available White nose syndrome (WNS is a cutaneous fungal disease of bats. WNS is responsible for unprecedented mortalities in North American cave bat populations. There have been few descriptions of enzyme activities that may function in WNS host/pathogen interactions, while no study has isolated and described secreted proteases. To address the hypothesis that Pseudogymnoascus destructans secretes extracellular proteases that function in wing necrosis during WNS infection, the object of this study was to culture P. destructans on various media, then isolate and structurally identify those proteases accumulated stably in the culture medium. We found a single dominant protease activity on minimal nutrient broth enriched with protein substrates, which was strongly inhibited by phenylmethylsulfonyl fluoride. This P. destructans serine protease (PdSP1 was isolated by preparative isoelectric focusing and concanavalin A lectin affinity chromatography. PdSP1 showed a molecular weight 27,900 (estimated by SDS-PAGE, broad pH optimum 6-8, and temperature optimum 60°C. Structural characterization of PdSP1 by MALDI-TOF MS, Orbitrap MS/MS, and Edman amino-terminal peptide sequencing matched it directly to a hypothetical protein accession from the sequenced P. destructans genome that is further identified as a MEROPS family S8A subtilisin-like serine peptidase. Two additional isoforms, PdSP2 and PdSP3, were identified in the P. destructans genome with 90% and 53% homology, respectively. P. destructans S8A serine proteases showed closer sequence conservation to P. pannorum and plant pathogenic fungi than to human pathogenic dermatophytes. Peptide-specific polyclonal antibodies developed from the PdSP1 sequence detected the protein in western blots. These subtilisin-like serine proteases are candidates for further functional studies in WNS host-pathogen interaction.

Isolation and identification of an extracellular subtilisin-like serine protease secreted by the bat pathogen Pseudogymnoascus destructans.

Science.gov (United States)

Pannkuk, Evan L; Risch, Thomas S; Savary, Brett J

2015-01-01

White nose syndrome (WNS) is a cutaneous fungal disease of bats. WNS is responsible for unprecedented mortalities in North American cave bat populations. There have been few descriptions of enzyme activities that may function in WNS host/pathogen interactions, while no study has isolated and described secreted proteases. To address the hypothesis that Pseudogymnoascus destructans secretes extracellular proteases that function in wing necrosis during WNS infection, the object of this study was to culture P. destructans on various media, then isolate and structurally identify those proteases accumulated stably in the culture medium. We found a single dominant protease activity on minimal nutrient broth enriched with protein substrates, which was strongly inhibited by phenylmethylsulfonyl fluoride. This P. destructans serine protease (PdSP1) was isolated by preparative isoelectric focusing and concanavalin A lectin affinity chromatography. PdSP1 showed a molecular weight 27,900 (estimated by SDS-PAGE), broad pH optimum 6-8, and temperature optimum 60°C. Structural characterization of PdSP1 by MALDI-TOF MS, Orbitrap MS/MS, and Edman amino-terminal peptide sequencing matched it directly to a hypothetical protein accession from the sequenced P. destructans genome that is further identified as a MEROPS family S8A subtilisin-like serine peptidase. Two additional isoforms, PdSP2 and PdSP3, were identified in the P. destructans genome with 90% and 53% homology, respectively. P. destructans S8A serine proteases showed closer sequence conservation to P. pannorum and plant pathogenic fungi than to human pathogenic dermatophytes. Peptide-specific polyclonal antibodies developed from the PdSP1 sequence detected the protein in western blots. These subtilisin-like serine proteases are candidates for further functional studies in WNS host-pathogen interaction.

AMPK in Pathogens.

Science.gov (United States)

Mesquita, Inês; Moreira, Diana; Sampaio-Marques, Belém; Laforge, Mireille; Cordeiro-da-Silva, Anabela; Ludovico, Paula; Estaquier, Jérôme; Silvestre, Ricardo

2016-01-01

During host-pathogen interactions, a complex web of events is crucial for the outcome of infection. Pathogen recognition triggers powerful cellular signaling events that is translated into the induction and maintenance of innate and adaptive host immunity against infection. In opposition, pathogens employ active mechanisms to manipulate host cell regulatory pathways toward their proliferation and survival. Among these, subversion of host cell energy metabolism by pathogens is currently recognized to play an important role in microbial growth and persistence. Extensive studies have documented the role of AMP-activated protein kinase (AMPK) signaling, a central cellular hub involved in the regulation of energy homeostasis, in host-pathogen interactions. Here, we highlight the most recent advances detailing how pathogens hijack cellular metabolism by suppressing or increasing the activity of the host energy sensor AMPK. We also address the role of lower eukaryote AMPK orthologues in the adaptive process to the host microenvironment and their contribution for pathogen survival, differentiation, and growth. Finally, we review the effects of pharmacological or genetic AMPK modulation on pathogen growth and persistence.

Anti - microbial resistance stratified by risk factor among Escherichia coli strains isolated from the urinary tract at a rural clinic in Central India

Directory of Open Access Journals (Sweden)

Chatterjee B

2009-01-01

Full Text Available Background: The failure of empirical therapy is frequently observed, even in community-acquired urinary tract infections. We, therefore, conducted a prospective, clinic-based study in 2004-2005 to document anti-microbial resistance rates and correlate them with possible risk factors to assist empirical decision-making. Materials and Methods: Symptomatic patients with pyuria underwent urine culture. Isolates were identified using standard methods and anti-microbial resistance was determined by disk-diffusion. Ultrasonography was used to detect complicating factors. Patients were stratified by the presence of complicating factors and history of invasive procedures for comparison of resistance rates. Statistical Method Used: Chi-square or Fisher exact tests, as appropriate. Results: There were 156 E. coli isolates, of which 105 were community-acquired. Twenty-three community-acquired isolates were from patients with complicating factors while 82 were from patients without any. Fifty-one isolates were from patients who had recently undergone invasive procedures on the urinary tract. Thirty-two community-acquired isolates from reproductive-age women without apparent complicating factors had resistance rates of 50% or above against tetracyclines, Co-trimoxazole, aminopenicillins, Nalidixic acid, Ciprofloxacin and 1 st generation cephalosporins. Resistance rates were significantly higher among isolates from patients subjected to invasive procedures, except against Co-trimoxazole, tetracyclines and Amikacin. Conclusion: High rates of anti-microbial resistance in community-acquired uropathogens have made antimicrobial sensitivity testing necessary even in a rural, primary-care setting.

Bacterial food-borne pathogens in Indian food

International Nuclear Information System (INIS)

Bandekar, J.R.

2015-01-01

Food technology and food processing techniques have made tremendous advances in preservation of food and ensuring safety of food by killing food-borne pathogens. In addition to old techniques such as pasteurization, canning, dehydration, fermentation and salting, a number of new techniques such as radiation processing, high pressure technology and pulsed electric field technology are being applied for preservation of food and to ensure food safety. Total Quality Management (TQM) concepts have been developed to take care of food safety from farm to table. Hazard Analysis at Critical Control Points (HACCP) is being applied for mass scale production of food to make food free from pathogens. Despite these advances, food-borne diseases have become one of the most widespread public health problems in the world. About two thirds of all the outbreaks are traced to microbial contaminated food. According to World Health Organization (WHO) estimates, food-borne and waterborne diarrhoeal diseases kill an estimated 2 million people annually, including many children. Food safety is a major concern not only for developing countries but also for the developed countries. A number of factors such as emergence of new food-borne pathogens, development of drug resistance in pathogens, changing life style, globalization of the food supply etc. are responsible for the continuous persistence of food-borne diseases. The food-borne disease outbreaks due to E. coli O157:H7, Listeria monocytogenes, Salmonella and Campylobacter, are responsible for recall of many foods resulting in heavy losses to food industry. Due to consumer demand, a number of Ready-To-Eat (RTE) minimally processed foods are increasingly marketed; however, there is increased risk of foodborne diseases with these products. Food Technology Division of Bhabha Atomic Research Centre, Mumbai, has been working on food-borne bacterial pathogens particularly Salmonella, Campylobacter, Listeria monocytogenes, Vibrio and Aeromonasf

Escherichia coli type III secretion system 2 (ETT2) is widely distributed in avian pathogenic Escherichia coli isolates from Eastern China.

Science.gov (United States)

Wang, S; Liu, X; Xu, X; Zhao, Y; Yang, D; Han, X; Tian, M; Ding, C; Peng, D; Yu, S

2016-10-01

Pathogens utilize type III secretion systems to deliver effector proteins, which facilitate bacterial infections. The Escherichia coli type III secretion system 2 (ETT2) which plays a crucial role in bacterial virulence, is present in the majority of E. coli strains, although ETT2 has undergone widespread mutational attrition. We investigated the distribution and characteristics of ETT2 in avian pathogenic E. coli (APEC) isolates and identified five different ETT2 isoforms, including intact ETT2, in 57·6% (141/245) of the isolates. The ETT2 locus was present in the predominant APEC serotypes O78, O2 and O1. All of the ETT2 loci in the serotype O78 isolates were degenerate, whereas an intact ETT2 locus was mostly present in O1 and O2 serotype strains, which belong to phylogenetic groups B2 and D, respectively. Interestingly, a putative second type III secretion-associated locus (eip locus) was present only in the isolates with an intact ETT2. Moreover, ETT2 was more widely distributed in APEC isolates and exhibited more isoforms compared to ETT2 in human extraintestinal pathogenic E. coli, suggesting that APEC might be a potential risk to human health. However, there was no distinct correlation between ETT2 and other virulence factors in APEC.

Molecular serotyping, virulence gene profiling and pathogenicity of Streptococcus agalactiae isolated from tilapia farms in Thailand by multiplex PCR.

Science.gov (United States)

Kannika, K; Pisuttharachai, D; Srisapoome, P; Wongtavatchai, J; Kondo, H; Hirono, I; Unajak, S; Areechon, N

2017-06-01

This study aimed to biotype Streptococcus agalactiae isolated from tilapia farms in Thailand based on molecular biotyping methods and to determine the correlation between the serotype and virulence of bacteria. In addition to a biotyping (serotyping) technique based on multiplex PCR of cps genes, in this study, we developed multiplex PCR typing of Group B streptococcus (GBS) virulence genes to examine three clusters of virulence genes and their correlation with the pathogenicity of S. agalactiae. The epidemiology of S. agalactiae in Thailand was analysed to provide bacterial genetic information towards a future rational vaccine strategy for tilapia culture systems. Streptococcus agalactiae were isolated from diseased tilapia from different areas of Thailand. A total of 124 S. agalactiae isolates were identified by phenotypic analysis and confirmed by 16S rRNA PCR. Bacterial genotyping was conducted based on (i) molecular serotyping of the capsular polysaccharide (cps) gene cluster and (ii) virulence gene profiling using multiplex PCR analysis of 14 virulence genes (lmb, scpB, pavA, cspA, spb1, cyl, bca, rib, fbsA, fbsB, cfb, hylB, bac and pbp1A/ponA). Only serotypes Ia and III were found in this study; serotype Ia lacks the lmb, scpB and spb1 genes, whereas serotype III lacks only the bac gene. Virulence tests in juvenile Nile tilapia demonstrated a correlation between the pathogenicity of the bacteria and their virulence gene profile, with serotype III showing higher virulence than serotype Ia. Epidemiological analysis showed an almost equal distribution in all regions of Thailand, except serotype III was found predominantly in the southern areas. Only two serotypes of S. agalactiae were isolated from diseased tilapia in Thailand. Serotype Ia showed fewer virulence genes and lower virulence than serotype III. Both serotypes showed a similar distribution throughout Thailand. We identified two major serotypes of S. agalactiae isolates associated with the outbreak in

Microbial quality of agricultural water in Central Florida

Science.gov (United States)

Topalcengiz, Zeynal; Strawn, Laura K.

2017-01-01

The microbial quality of water that comes into the edible portion of produce is believed to directly relate to the safety of produce, and metrics describing indicator organisms are commonly used to ensure safety. The US FDA Produce Safety Rule (PSR) sets very specific microbiological water quality metrics for agricultural water that contacts the harvestable portion of produce. Validation of these metrics for agricultural water is essential for produce safety. Water samples (500 mL) from six agricultural ponds were collected during the 2012/2013 and 2013/2014 growing seasons (46 and 44 samples respectively, 540 from all ponds). Microbial indicator populations (total coliforms, generic Escherichia coli, and enterococci) were enumerated, environmental variables (temperature, pH, conductivity, redox potential, and turbidity) measured, and pathogen presence evaluated by PCR. Salmonella isolates were serotyped and analyzed by pulsed-field gel electrophoresis. Following rain events, coliforms increased up to 4.2 log MPN/100 mL. Populations of coliforms and enterococci ranged from 2 to 8 and 1 to 5 log MPN/100 mL, respectively. Microbial indicators did not correlate with environmental variables, except pH (P<0.0001). The invA gene (Salmonella) was detected in 26/540 (4.8%) samples, in all ponds and growing seasons, and 14 serotypes detected. Six STEC genes were detected in samples: hly (83.3%), fliC (51.8%), eaeA (17.4%), rfbE (17.4%), stx-I (32.6%), stx-II (9.4%). While all ponds met the PSR requirements, at least one virulence gene from Salmonella (invA-4.8%) or STEC (stx-I-32.6%, stx-II-9.4%) was detected in each pond. Water quality for tested agricultural ponds, below recommended standards, did not guarantee the absence of pathogens. Investigating the relationships among physicochemical attributes, environmental factors, indicator microorganisms, and pathogen presence allows researchers to have a greater understanding of contamination risks from agricultural surface

Microbial quality of agricultural water in Central Florida.

Directory of Open Access Journals (Sweden)

Zeynal Topalcengiz

Full Text Available The microbial quality of water that comes into the edible portion of produce is believed to directly relate to the safety of produce, and metrics describing indicator organisms are commonly used to ensure safety. The US FDA Produce Safety Rule (PSR sets very specific microbiological water quality metrics for agricultural water that contacts the harvestable portion of produce. Validation of these metrics for agricultural water is essential for produce safety. Water samples (500 mL from six agricultural ponds were collected during the 2012/2013 and 2013/2014 growing seasons (46 and 44 samples respectively, 540 from all ponds. Microbial indicator populations (total coliforms, generic Escherichia coli, and enterococci were enumerated, environmental variables (temperature, pH, conductivity, redox potential, and turbidity measured, and pathogen presence evaluated by PCR. Salmonella isolates were serotyped and analyzed by pulsed-field gel electrophoresis. Following rain events, coliforms increased up to 4.2 log MPN/100 mL. Populations of coliforms and enterococci ranged from 2 to 8 and 1 to 5 log MPN/100 mL, respectively. Microbial indicators did not correlate with environmental variables, except pH (P<0.0001. The invA gene (Salmonella was detected in 26/540 (4.8% samples, in all ponds and growing seasons, and 14 serotypes detected. Six STEC genes were detected in samples: hly (83.3%, fliC (51.8%, eaeA (17.4%, rfbE (17.4%, stx-I (32.6%, stx-II (9.4%. While all ponds met the PSR requirements, at least one virulence gene from Salmonella (invA-4.8% or STEC (stx-I-32.6%, stx-II-9.4% was detected in each pond. Water quality for tested agricultural ponds, below recommended standards, did not guarantee the absence of pathogens. Investigating the relationships among physicochemical attributes, environmental factors, indicator microorganisms, and pathogen presence allows researchers to have a greater understanding of contamination risks from agricultural

Microbial quality of agricultural water in Central Florida.

Science.gov (United States)

Topalcengiz, Zeynal; Strawn, Laura K; Danyluk, Michelle D

2017-01-01

The microbial quality of water that comes into the edible portion of produce is believed to directly relate to the safety of produce, and metrics describing indicator organisms are commonly used to ensure safety. The US FDA Produce Safety Rule (PSR) sets very specific microbiological water quality metrics for agricultural water that contacts the harvestable portion of produce. Validation of these metrics for agricultural water is essential for produce safety. Water samples (500 mL) from six agricultural ponds were collected during the 2012/2013 and 2013/2014 growing seasons (46 and 44 samples respectively, 540 from all ponds). Microbial indicator populations (total coliforms, generic Escherichia coli, and enterococci) were enumerated, environmental variables (temperature, pH, conductivity, redox potential, and turbidity) measured, and pathogen presence evaluated by PCR. Salmonella isolates were serotyped and analyzed by pulsed-field gel electrophoresis. Following rain events, coliforms increased up to 4.2 log MPN/100 mL. Populations of coliforms and enterococci ranged from 2 to 8 and 1 to 5 log MPN/100 mL, respectively. Microbial indicators did not correlate with environmental variables, except pH (P<0.0001). The invA gene (Salmonella) was detected in 26/540 (4.8%) samples, in all ponds and growing seasons, and 14 serotypes detected. Six STEC genes were detected in samples: hly (83.3%), fliC (51.8%), eaeA (17.4%), rfbE (17.4%), stx-I (32.6%), stx-II (9.4%). While all ponds met the PSR requirements, at least one virulence gene from Salmonella (invA-4.8%) or STEC (stx-I-32.6%, stx-II-9.4%) was detected in each pond. Water quality for tested agricultural ponds, below recommended standards, did not guarantee the absence of pathogens. Investigating the relationships among physicochemical attributes, environmental factors, indicator microorganisms, and pathogen presence allows researchers to have a greater understanding of contamination risks from agricultural surface

Insecticidal Activity of Isolated Bacteria from Hyphantria cunea (Drury (Lepidoptera: Arctiidae

Directory of Open Access Journals (Sweden)

Nurcan Albayrak İskender

2017-04-01

Full Text Available The fall webworm (Hyphantria cunea is a polyphagous pest with numerous host plants. In the present study, the bacterial flora of H.cunea was investigated to identify new organisms that can be used as microbial control agent against the pest. Six bacteria were isolated and cultured from H. cunea. Some morphological, biochemical and other phenotypic characteristics (with API 20E, API 50 CH, API Staph and API Coryne kits of bacterial isolates were determined. In addition, 16S rRNA gene region was sequenced. As a result of the studies conducted, bacterial isolates were identified as Lysinibacillus sphaericus (Abk1, Bacillus amyloliquefaciens (Abk2, Staphylococcus sciuri (Abk4, Kocuria palustris (Abk6, Arthrobacter arilaitensis (Abk7 and Microbacterium oxydans (Abk8. All bacterial isolates were tested for 12 days against third-fourth instar larvae of H. cunea. The highest insecticidal activity was obtained from L. sphaericus (Abk1 with 30% after application (p<0.05. These results indicate that L. sphaericus (Abk1 can be taken into account in the microbial pest control of H. cunea. In the future, further studies will be conducted by using pathogenicity enrichment strategies of L. sphaericus (Abk1 (ex. combining with other entomopathogens or insecticides in order to increase the effectiveness on H. cunea.

Differences in pathogenicity of three animal isolates of Mycobacterium species in a mouse model.

Directory of Open Access Journals (Sweden)

Haodi Dong

Full Text Available Animal mycobacterioses are among the most important zoonoses worldwide. These are generally caused by either Mycobacterium tuberculosis (MTB, M. bovis (MBO or M. avium (MAV. To test the hypothesis that different species of pathogenic mycobacteria isolated from varied anatomic locations or animal species differ in virulence and pathogenicity, we performed experiments with three mycobacteria strains (NTSE-3(MTB, NTSE-4(MBO and NTSE-5 (MAV obtained from animal species. Spoligotyping analysis was used to confirm both MTB and MBO strains while the MAV strain was confirmed by 16s rDNA sequencing. BALB/c mice were intranasally infected with the three strains at low and high CFU doses to evaluate variations in pathogenicity. Clinical and pathological parameters were assessed. Infected mice were euthanized at 80 days post-inoculation (dpi. Measures of lung and body weights indicated that the MBO infected group had higher mortality, more weight loss, higher bacterial burden and more severe lesions in lungs than the other two groups. Cytokine profiles showed higher levels of TNF-α for MBO versus MTB, while MAV had the highest amounts of IFN-β in vitro and in vivo. In vitro levels of other cytokines such as IL-1β, IL-10, IL-12, IL-17, and IFN-β showed that Th1 cells had the strongest response in MBO infected mice and that Th2 cells were inhibited. We found that the level of virulence among the three isolates decreased in the following order MBO>MTB>MAV.

High-throughput sequencing reveals microbial communities in drinking water treatment sludge from six geographically distributed plants, including potentially toxic cyanobacteria and pathogens.

Science.gov (United States)

Xu, Hangzhou; Pei, Haiyan; Jin, Yan; Ma, Chunxia; Wang, Yuting; Sun, Jiongming; Li, Hongmin

2018-04-10

The microbial community structures of drinking water treatment sludge (DWTS) generated for raw water (RW) from different locations and with different source types - including river water, lake water and reservoir water -were investigated using high-throughput sequencing. Because the unit operations in the six DWTPs were similar, community composition in fresh sludge may be determined by microbial community in the corresponding RW. Although Proteobacteria, Cyanobacteria, Bacteroidetes, Firmicutes, Verrucomicrobia, and Planctomycetes were the dominant phyla among the six DWTS samples, no single phylum exhibited similar abundance across all the samples, owing to differences in total phosphorus, chemical oxygen demand, Al, Fe, and chloride in RW. Three genera of potentially toxic cyanobacteria (Planktothrix, Microcystis and Cylindrospermopsis), and four potential pathogens (Escherichia coli, Bacteroides ovatus, Prevotella copri and Rickettsia) were found in sludge samples. Because proliferation of potentially toxic cyanobacteria and Rickettsia in RW was mainly affected by nutrients, while growth of Escherichia coli, Bacteroides ovatus and Prevotella copri in RW may be influenced by Fe, control of nutrients and Fe in RW is essential to decrease toxic cyanobacteria and pathogens in DWTS. Copyright © 2018 Elsevier B.V. All rights reserved.

Pathogenicity of Bacillus thuringiensis isolated from two species of Acromyrmex (Hymenoptera, Formicidae

Directory of Open Access Journals (Sweden)

L. M. N. Pinto

Full Text Available The control of Acromyrmex leaf-cutting ants is necessary due to the severe damage they cause to diverse crops. A possibility was to control them using the bacterium Bacillus thuringiensis (Bt that characteristically produces insecticidal crystal proteins (ICPs. The ICPs have been effective in controlling lepidopterans, dipterans, and coleopterans, but their action against hymenopterans is unknown. This paper describes an attempt to isolate Bt from ants of two Acromyrmex species, to evaluate its pathogenicity towards these ants, and to test isolates by PCR. Bacterial isolates of Bt obtained from A. crassispinus and A. lundi have been assayed against A. lundi in the laboratory. The bioassays were carried out in BOD at 25°C, with a 12-hour photoperiod, until the seventh day after treatment. The Bt isolates obtained were submitted to total DNA extraction and tested by PCR with primers specific to cry genes. The results showed Bt presence in 40% of the assessed samples. The data from the in vivo assays showed a mortality rate higher than 50% in the target population, with the Bt HA48 isolate causing 100% of corrected mortality. The PCR results of Bt isolates showed a magnification of DNA fragments relative to cry1 genes in 22% of the isolates, and cry9 in 67%. Cry2, cry3, cry7, and cry8 genes were not detected in the tested samples, and 22% had no magnified DNA fragments corresponding to the assessed cry genes. The results are promising not only regarding allele identification in new isolates, but also fort the assays aimed at determining the Bt HA48 LC50's, which can eventually be applied in controlling of Acromyrmex leaf-cutting ants.

Middle East Desert Dust Exposure: Health Risks from Metals and Microbial Pathogens

Science.gov (United States)

Lyles, M. B.

2014-12-01

In the Middle East, dust and sand storms are a persistent problem and can deliver significant amounts of micro-particulates via inhalation into the mouth, nasal pharynx, & lungs due to the fine size and abundance of these micro-particulates. The chronic and acute health risks of this dust inhalation have not been well studied nor has the dust been effectively characterized as to its chemical composition, mineral content, or microbial flora. Scientific experiments were designed to study the Kuwaiti and Iraqi dust as to its physical, chemical, and biological characteristics and for its potential to cause adverse health effects. First, dust samples from different locations were collected and processed and exposure data collected. Initial chemical and physical characterization of each sample including particle size distribution and inorganic analysis was conducted, followed by characterization of biologic flora of the dust, including bacteria, fungi and viruses. Data indicates that the mineralized dust is composed of calcium carbonate over a matrix of metallic silicate nanocrystals containing a variety of trace and heavy metals constituting ~3 % of the PM10 particles by weight, of which ~1% is bioaccessible aluminum and reactive iron, each. The particles also consist of ~1% bioavailable aluminum and reactive iron each. Microbial analysis reveals a significant biodiversity of bacterial, fungi, and viruses of which ~30% are known pathogens. Of the microbes identified, several have hemolytic properties and most have significant antibiotic resistance. Viral analysis indicates a tremendous amount of virons with a large percent of RNA viruses. The level of total suspended particle mass at PM 10 along with environmental & physiological conditions present constitute an excessive exposure to micro-particulates including PM 2.5 and the potential for adverse health effects. Reported data on cell culture and animal studies have indicated a high level of toxicity to these dust

The Effectiveness Evaluation of Current Disinfectants on Pathogens Isolated from Surface of Different Parts of Shahid Sadughi Accidents Burns Hospital in City of Yazd

Directory of Open Access Journals (Sweden)

Fatemeh Sahlabadi

2016-03-01

Full Text Available Background: The burn unit is a suitable environment for the growth of pathogenic bacteria that can reduce these pathogens by appropriate disinfection methods. So, choosing an appropriate disinfectant and applying standard methods of disinfection can be effective in reducing nosocomial infections. The aim of this study is evaluation of efficacy of current disinfectants on pathogens isolated from surface of different parts of Shahid Sadughi accidents burns hospital in city of Yazd. Methods: In this study, the sampling method has done simple randomly and 240 samples were collected from 30 different parts of hospital surfaces (for every disinfectant 30 samples before and 30 samples after disinfection. The samples in the Microbiology laboratory of Medical Sciences University were cultured on blood agar and EMB agar culture. Colonies that were suspected to pathogens were identified by biochemical tests and their colony count was determined. Data were analyzed using Paired T-test. Results: The average of isolated bacteria at 4 parts of burn unit of hospital before disinfecting by Deconex 50 AF, Descoscid, Epimax SC and Silvosept was 58.02, 18897.28, 30989.05 and 38.52 respectively and after disinfecting was 12.8, 0.62, 1.65 and 5.09 respectively. Reducing of contamination in all disinfectants shown a significant difference (p<0.05. The most common isolated pathogens were Pseudomonas aeruginosa, Klebsiella, staphylococcus aureus, Enterobacter and Escherichia coli. Conclusion: The results showed that all disinfectants was effective on isolated pathogens and also have shown a significant difference (p<0.05 between the average of bacteria count before and after disinfection.

Incidence of bovine clinical mastitis in Jammu region and antibiogram of isolated pathogens

OpenAIRE

Adil Majid Bhat; Jasvinder Singh Soodan; Rajiv Singh; Ishfaq Ahmad Dhobi; Tufail Hussain; Mohammad Yousuf Dar; Muheet Mir

2017-01-01

Aim: This study was conducted to evaluate the incidence of clinical mastitis in bovines of Jammu region, to identify the infectious organisms responsible for it, and the antimicrobial sensitivity of isolated pathogens. Materials and Methods: The study was conducted on cases that were presented to the Medicine Division of Teaching Veterinary Clinical Complex, Faculty of Veterinary Sciences and Animal Husbandry, R.S. Pura, Jammu, Jammu and Kashmir. A total of 260 cases of bovines were prese...

Regulatory Proteolysis in Arabidopsis-Pathogen Interactions.

Science.gov (United States)

Pogány, Miklós; Dankó, Tamás; Kámán-Tóth, Evelin; Schwarczinger, Ildikó; Bozsó, Zoltán

2015-09-24

Approximately two and a half percent of protein coding genes in Arabidopsis encode enzymes with known or putative proteolytic activity. Proteases possess not only common housekeeping functions by recycling nonfunctional proteins. By irreversibly cleaving other proteins, they regulate crucial developmental processes and control responses to environmental changes. Regulatory proteolysis is also indispensable in interactions between plants and their microbial pathogens. Proteolytic cleavage is simultaneously used both by plant cells, to recognize and inactivate invading pathogens, and by microbes, to overcome the immune system of the plant and successfully colonize host cells. In this review, we present available results on the group of proteases in the model plant Arabidopsis thaliana whose functions in microbial pathogenesis were confirmed. Pathogen-derived proteolytic factors are also discussed when they are involved in the cleavage of host metabolites. Considering the wealth of review papers available in the field of the ubiquitin-26S proteasome system results on the ubiquitin cascade are not presented. Arabidopsis and its pathogens are conferred with abundant sets of proteases. This review compiles a list of those that are apparently involved in an interaction between the plant and its pathogens, also presenting their molecular partners when available.

Laboratory simulation reveals significant impacts of ocean acidification on microbial community composition and host-pathogen interactions between the blood clam and Vibrio harveyi.

Science.gov (United States)

Zha, Shanjie; Liu, Saixi; Su, Wenhao; Shi, Wei; Xiao, Guoqiang; Yan, Maocang; Liu, Guangxu

2017-12-01

It has been suggested that climate change may promote the outbreaks of diseases in the sea through altering the host susceptibility, the pathogen virulence, and the host-pathogen interaction. However, the impacts of ocean acidification (OA) on the pathogen components of bacterial community and the host-pathogen interaction of marine bivalves are still poorly understood. Therefore, 16S rRNA high-throughput sequencing and host-pathogen interaction analysis between blood clam (Tegillarca granosa) and Vibrio harveyi were conducted in the present study to gain a better understanding of the ecological impacts of ocean acidification. The results obtained revealed a significant impact of ocean acidification on the composition of microbial community at laboratory scale. Notably, the abundance of Vibrio, a major group of pathogens to many marine organisms, was significantly increased under ocean acidification condition. In addition, the survival rate and haemolytic activity of V. harveyi were significantly higher in the presence of haemolymph of OA treated T. granosa, indicating a compromised immunity of the clam and enhanced virulence of V. harveyi under future ocean acidification scenarios. Conclusively, the results obtained in this study suggest that future ocean acidification may increase the risk of Vibrio pathogen infection for marine bivalve species, such as blood clams. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phylogenetic relationships and pathogenicity variation of two Newcastle disease viruses isolated from domestic ducks in Southern China.

Science.gov (United States)

Kang, Yinfeng; Li, Yanling; Yuan, Runyu; Li, Xianwei; Sun, Minhua; Wang, Zhaoxiong; Feng, Minsha; Jiao, Peirong; Ren, Tao

2014-08-12

Newcastle disease (ND) is an OIE listed disease caused by virulent avian paramyxovirus type 1 (APMV-1) strains, which is enzootic and causes large economic losses in the poultry sector. Genotype VII and genotype IX NDV viruses were the predominant circulating genotype in China, which may possibly be responsible for disease outbreaks in chicken flocks in recent years. While ducks and geese usually have exhibited inapparent infections. In the present study, we investigate the complete genome sequence, the clinicopathological characterization and transmission of two virulent Newcastle disease viruses, SS-10 and NH-10, isolated from domestic ducks in Southern China in 2010. F, and the complete gene sequences based on phylogenetic analysis demonstrated that SS-10 (genotype VII) and NH-10 (genotype IX) belongs to class II. The deduced amino acid sequence was (112)R-R-Q-K/R-R-F(117) at the fusion protein cleavage site. Animal experiment results showed that the SS-10 virus isolated from ducks was highly pathogenic for chickens and geese, but low pathogenic for ducks. It could be detected from spleen, lung, kidney, trachea, small intestine, bursa of fabricius, thymus, pancreas and cecal tonsils, oropharyngeal and cloacal swabs, and could transmit to the naive contact birds. Moreover, it could transmit to chickens, ducks and geese by naive contact. However, the NH-10 virus isolated from ducks could infect some chickens, ducks and geese, but only caused chickens to die. Additionally, it could transmit to the naive contact chickens, ducks, and geese. The two NDV isolates exhibited different biological properties with respect to pathogenicity and transmission in chickens, ducks and geese. Therefore, no species-preference exists for chicken, duck or goose viruses and more attention should be paid to the trans-species transmission of VII NDVs between ducks, geese and chickens for the control and eradication of ND.

Azospirillum brasilense, a Beneficial Soil Bacterium: Isolation and Cultivation.

Science.gov (United States)

Alexandre, Gladys

2017-11-09

Bacteria of the genus Azospirillum comprise 15 species to date, with A. brasilense the best studied species in the genus. Azospirillum are soil bacteria able to promote the growth of plants from 113 species spanning 35 botanical families. These non-pathogenic and beneficial bacteria are ubiquitous in soils and inhabit the roots of diverse plants. These bacteria are microaerophilic, able to fix nitrogen under free-living conditions, motile, and able to navigate in gradients of various chemicals, including oxygen. These physiological traits are used to isolate these soil bacteria from soil and plant root samples, providing isolates that can be used for studying microbial physiology and plant growth promotion. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

Time-course monitoring of urban bioaerosol bacterial communities and its use in microbial hazard identification during Asian Dust events in Seoul, Korea

Science.gov (United States)

Park, J.

2015-12-01

The microbial communities transported by Asian dust events have attracted much attention as bioaerosols because the transported airborne microbes may strongly influence the downwind ecosystems and potentially human health in East Asia. Bioaerosol study has received relatively little attention and their characterization and risk assessments remain poorly developed. We used high throughput 16S rRNA gene targeted pyrosequencing and real-time quantitative PCR (qPCR) to monitor airborne bacterial communities and assess their potential risk. We monitored microbial communities in bioaerosol in Seoul between 2011 and 2013 using high volume air samplers. Six samples were collected during Asian dust (AD) events and the other 34 samples were urban air collected during non-Asian dust (non-AD) events. According to the qPCR result, the gene copy numbers of 16S rRNA genes were significantly higher during the AD events (P culture methods. 16S rRNA gene sequences of several pathogens were detected and their relative abundances appeared to have increased with increased concentrations of PM10. About 1% of Bacillus isolates were identified as known pathogenic B. cereus, confirming their presence in Asian dust samples. The qPCR detection of bceT gene, which codes for an enterotoxin in B. cereus group, was significantly increased in the AD dust samples over the non-AD samples. The following MLST assessment and virulence test of cultivated Bacillus isolates showed that B. cereus, B. licheniformis and B. mycoides were identified as pathogenic bacteria, and these pathogenic bacteria were usually more abundant during AD events. To assess the possible associations of identified pathogens on the hospital stroke admissions of residents in Seoul, we identified sixteen bioaerosol episodes using Poisson regression and calculated relative risk. The findings are useful in building a database for bacterial pathogens in AD events.

Pathogenicity of local isolate virus BHV-1 as the aetiological agent of Infectious Bovine Rhinotracheitis in Bali Cattle

Directory of Open Access Journals (Sweden)

Rini I Damayanti

2005-10-01

Full Text Available Infectious Bovine Rhinotracheitis is a disease of cattle characterised by clinical signs of the upper respiratory tract, reproductive tract and nervous system. A study to define the pathogenicity of four BHV-1 local isolates has been conducted. Fourteen Bali cattle that were free of BHV-1 has been selected and divided into four treatment groups. Each group of three was infected with virus isolate I, II, III and IV respectively with approximately a dose of 108TCID50 /10 ml and two cattle were used as control animals. Isolate I and III were originated from semen from IBR positive bulls number G 867 and G 148 respectively whereas isolate II was collected from vaginal mucosa and isolate IV was from nasal mucosa of IBR positive cattle treated with dexamethasone. Clinical response, gross-pathological and histopathological changes were observed. Immunohistochemical staining was applied to detect the antigen in tissue section. The results show that the BHV-1 local isolates could produce IBR syndrome namely fever and changes in the respiratory and reproductive tracts even though the clinical responses seemed to be disappeared by 21 days PI. Grossly there were hyperaemic nasal and vaginal mucosa and pneumonia whereas histologically there were non suppurative rhinitis, tracheitis, pneumonia and vulvovaginitis. Immunohistochemically the antigen was detected in the nasal concha and trachea. Dexamethasone treatment at 60-64 days PI could produce less severe clinical features and the second necroppsy at 69 days PI also results in less severe pathological responses. The findings also suggest that the pathogenicity of BHV-1 local isolates were as follows: isolates I, II, IV and III.

Isolation and identification of highly pathogenic avian influenza virus subtype H5N1 in peafowl (Pavo cristatus).

Science.gov (United States)

Ismail, Mahmoud Moussa; Khan, Owais Ahmed; Cattoli, Giovanni; Lu, Huaguang

2010-03-01

An outbreak of highly pathogenic avian influenza (HPAI) virus subtype H5N1 was first diagnosed in a "backyard" flock of peafowl (Pavo cristatus) raised on palace premises in the Kingdom of Saudi Arabia in December 3, 2007. The flock consisted of 40 peafowl, and their ages ranged from 3 to 5 years old. Affected birds suffered from depression, anorexia, and white diarrhea. Four dead birds were submitted for HPAI diagnosis at the Central Veterinary Diagnostic Laboratory in Riyadh. Brain and liver tissues and tracheal and cloacal swabs were taken from the dead birds and processed for a real-time reverse transcriptase (RT)-PCR test and virus isolation in specific-pathogen-free embryonating chicken eggs. The H5N1 subtype of avian influenza virus was isolated from the four dead birds and identified by a real-time RT-PCR before and after egg inoculation. The virus isolates were characterized as HPAI H5N1 virus by sequencing analysis. Phylogenetic comparisons revealed that the H5N1 viruses isolated from peafowl belong to the genetic clade 2.2 according to the World Health Organization nomenclature. The peafowl H5N1 virus falls into 2.2.2 sublineage II and clusters with the H5N1 viruses isolated from poultry in Saudi Arabia in 2007-08.

Biochemical studies on antibiotic production from Streptomyces sp.: Taxonomy, fermentation, isolation and biological properties

OpenAIRE

Houssam M. Atta

2015-01-01

Tunicamycin is a nucleotide antibiotic which was isolated from the fermentation broth of a Streptomyces strain No. T-4. According to the morphological, cultural, physiological and biochemical characteristics, and 16S rDNA sequence analysis, strain T-4 was identified as Streptomyces torulosus. It is active in vitro against some microbial pathogenic viz: Staphylococcus aureus, NCTC 7447; Micrococcus lutea, ATCC 9341; Bacillus subtilis, NCTC 10400; B. pumilus, NCTC; Klebsiella pneumonia, NCIMB 9...

Occurrence of weak mutators among avian pathogenic Escherichia coli (APEC) isolates causing salpingitis and peritonitis in broiler breeders

DEFF Research Database (Denmark)

Pires dos Santos, Teresa M S; Bisgaard, Magne; Kyvsgaard, Niels Christian

2014-01-01

A collection of 46 avian pathogenic Escherichia coli (APEC) isolates was examined for the presence of mutators by determining the rate of mutation to rifampicin resistance. The collection included 34 E. coli isolates obtained in pure culture from chronic lesions of salpingitis and peritonitis in 34...... broiler breeders, of which 12 were associated with the development of secondary septicemia. Twelve additional isolates were obtained from a clonal outbreak (ST95) of E. coli peritonitis syndrome (EPS), the lesions of which changed gradually over time into a subacute/chronic form. The hypothesis...

Lyophilization as a method for pathogens long term preservation

Directory of Open Access Journals (Sweden)

Milošević Mirjana B.

2007-01-01

Full Text Available Lyophilization (freeze-drying is one of the most suitable methods used for a long term preservation of pathogens. The aim of this paper was the application of lyophilization for storage of three significant plant pathogens: Fusarium graminearum, Helminthosporium gramineum, and Pseudomonas syringae pv. gylicinea, respectively. The plant material was collected continuously (during a four year period 2002-2006, depending on a plant development stage, from different localities in Vojvodina. Pathogens were isolated from diseased parts with characteristic symptoms, and placed on nutritive media specific for a certain pathogen, using standard phytopathological methods. Lyophilization was carried out in marked and coded ampoules by freezing and drying of pathogen suspension and nutritive medium. Revitalization of lyophilized isolates was done after four days. High percentage of revitalization was characteristic for all studied isolates, and it ranged from 85-92%, confirming that lyophilized pathogens would be capable of keeping viability for a long time in the collection. Besides above mentioned pathogens, there were 200 isolates in the collection, originating mostly from field and vegetable crops. Each isolate that was put into the Collection, was followed by all the necessary data such as: name of the pathogen, number of isolates, locality, host plant year of isolation, name of the researcher and other relevant data.

Isolation of antibiotic-resistant pathogenic and potentially ...

African Journals Online (AJOL)

2010-09-13

Sep 13, 2010 ... The aim of the present study is to determine the pathogenic and potentially ... Keywords: pathogenic bacteria; antibiotic resistance; carpets; mosques; Tripoli; Libya .... During the process of praying, a Muslim is obliged to go.

Pathogenic microbial ancient DNA: a problem or an opportunity?

DEFF Research Database (Denmark)

Willerslev, Eske; Cooper, Alan

2006-01-01

cloning. Yet these studies have used mobile insertion elements (e.g. IS 6110 in tuberculosis) or conserved loci (e.g. 16S) to detect the presence of pathogens, and very similar or identical sequences have been reported from environmental bacteria (Gilbert et al. 2004). For example, Rollo & Marota (1999......We agree with Donoghue & Spigelman (2005) that, although pathogen studies hold great potential, any discussion requires a critical assessment of the results to date. However, we did note, as did Pääbo et al. (2004), that the field of ancient pathogen DNA still lacks a series of well......-controlled and rigorous studies that address technical issues and reliability criteria. This is unfortunate, as the rapid evolutionary rate of many pathogens offers a unique means to establish the authenticity of ancient pathogen sequences-since they should clearly be ancestral to modern genetic diversity (e.g. Reid et...

Soil microbial functional and fungal diversity as influenced by municipal sewage sludge accumulation.

Science.gov (United States)

Frąc, Magdalena; Oszust, Karolina; Lipiec, Jerzy; Jezierska-Tys, Stefania; Nwaichi, Eucharia Oluchi

2014-08-28

Safe disposal of municipal sewage sludge is a challenging global environmental concern. The aim of this study was to assess the response of soil microbial functional diversity to the accumulation of municipal sewage sludge during landfill storage. Soil samples of a municipal sewage sludge (SS) and from a sewage sludge landfill that was 3 m from a SS landfill (SS3) were analyzed relative to an undisturbed reference soil. Biolog EcoPlatesTM were inoculated with a soil suspension, and the Average Well Color Development (AWCD), Richness (R) and Shannon-Weaver index (H) were calculated to interpret the results. The fungi isolated from the sewage sludge were identified using comparative rDNA sequencing of the LSU D2 region. The MicroSEQ® ID software was used to assess the raw sequence files, perform sequence matching to the MicroSEQ® ID-validated reference database and create Neighbor-Joining trees. Moreover, the genera of fungi isolated from the soil were identified using microscopic methods. Municipal sewage sludge can serve as a habitat for plant pathogens and as a source of pathogen strains for biotechnological applications.

Antimicrobial sensitivity and frequency of DRUG resistance among bacterial strains isolated from cancer patients

International Nuclear Information System (INIS)

Faiz, M.; Bashir, T.

2004-01-01

Blood stream infections (bacteremia) is potentially life threatening. Concomitant with a change in the incidence and epidemiology of infecting organisms, there has been an increase in resistance to many antibiotic compounds. The widespread emergence of resistance among bacterial pathogens has an impact on our ability to treat patients effectively. The changing spectrum of microbial pathogens and widespread emergence of microbial resistance to antibiotic drugs has emphasized the need to monitor the prevalence of resistance in these strains. In the present study frequency of isolation of clinically significant bacteria and their susceptibility and resistance pattern against a wide range of antimicrobial drugs from positive blood cultures collected during 2001-2003 was studied. A total of 102 consecutive isolates were found with 63% gram positive and 44% gram negative strains. The dominating pathogens were Staphylococcus aureus (51%), Streptococci (31%), Pseudomonas (40%), Proteus (13%), Klebsiella (13%). The isolated strains were tested against a wide range of antibiotics belonging to cephalosporins, aminoglycosides and quinolone derivative group by disk diffusion method. It has been observed that isolated strains among gram positive and negative strains showed different level of resistance against aminoglycosides and cephalosporin group of antibiotics with gram positives showing highest number and frequency of resistance against aminoglycosides (40-50%) and cephalosporins.(35-45%) whereas cephalosporins were found to be more effective against gram negatives with low frequency of resistant strains. Cabapenem and quinolone derivative drugs were found to be most effective among other groups in both gram positive and negative strains with 23-41% strains found sensitive to these two drugs. The frequency of sensitive strains against aminoglycoside and cephalosporin in gram negative and gram positive strains were found to be decreasing yearwise with a trend towards an

Food safety knowledge and practices of abattoir and butchery shops and the microbial profile of meat in Mekelle City, Ethiopia

Science.gov (United States)

Haileselassie, Mekonnen; Taddele, Habtamu; Adhana, Kelali; Kalayou, Shewit

2013-01-01

Objective To assess the food safety knowledge and practices in meat handling, and to determine microbial load and pathogenic organisms in meat at Mekelle city. Methods A descriptive survey design was used to answer questions concerning the current status of food hygiene and sanitation practiced in the abattoir and butcher shops. Workers from the abattoir and butcher shops were interviewed through a structured questionnaire to assess their food safety knowledge. Bacterial load was assessed by serial dilution method and the major bacterial pathogens were isolated by using standard procedures. Results 15.4% of the abattoir workers had no health certificate and there was no hot water, sterilizer and cooling facility in the abattoir. 11.3% of the butchers didn't use protective clothes. There was a food safety knowledge gap within the abattoir and butcher shop workers. The mean values of bacterial load of abattoir meat, butcher shops and street meat sale was found to be 1.1×105, 5.6×105 and 4.3×106 cfu/g, respectively. The major bacterial pathogens isolated were Escherichia coli, Staphylococcus aureus and Bacillus cereus. Conclusions The study revealed that there is a reasonable gap on food safety knowledge by abattoir and butcher shop workers. The microbial profile was also higher compared to standards set by World Health Organization. Due attention should be given by the government to improve the food safety knowledge and the quality standard of meat sold in the city. PMID:23646306

Microbial contamination in 20-peso banknotes in Monterrey, Mexico.

Science.gov (United States)

Rocha-Gámez, Judith; Tejeda-Villarreal, Paula Nelly; Macías-Cárdenas, Patricia; Canizales-Oviedo, Jorge; Garza-González, Elvira; Ramírez-Villarreal, Elsa Guadalupe

2012-09-01

The authors' aim was to isolate and identify bacteria or yeast that may be present on the surface of 20-peso banknotes from the metropolitan area of Monterrey, Mexico. They randomly studied a total of 70 20-peso banknotes for the presence of bacteria and species of Candida by conventional methods. Out of the 70 banknotes, 48 (69%) were found to be contaminated. The most prevalent species observed was Candida kruseii (19 bills, 27%) followed by Burkholderia cepacia (9 bills, 13%); 22 (31%) bills showed no growth. Of the 48 contaminated bills, four (5.7%) yielded bacteria considered pathogenic and the other 44 bills (63%) yielded bacteria considered potentially pathogenic. Eleven bills showed more than one microbial species. The results of the authors' study show that contamination occurs on paper currency in the metropolitan area of Monterrey. The authors' findings provide evidence that currency banknotes may represent a threat to human health.

Pathogenicity of Nectriaceous Fungi on Avocado in Australia.

Science.gov (United States)

Parkinson, Louisamarie E; Shivas, Roger G; Dann, Elizabeth K

2017-12-01

Black root rot is a severe disease of young avocado trees in Australia causing black necrotic roots, tree stunting, and leaf drop prior to tree death. Nectriaceous fungi (Nectriaceae, Hypocreales), are commonly isolated from symptomatic roots. This research tested the pathogenicity of 19 isolates from Calonectria, Cylindrocladiella, Dactylonectria, Gliocladiopsis, and Ilyonectria, spp. collected from young avocado trees and other hosts. Glasshouse pathogenicity tests with 'Reed' avocado (Persea americana) seedlings confirmed that Calonectria ilicicola is a severe pathogen of avocado, causing stunting, wilting, and seedling death within 5 weeks of inoculation. Isolates of C. ilicicola from peanut, papaya, and custard apple were also shown to be aggressive pathogens of avocado, demonstrating a broad host range. An isolate of a Calonectria sp. from blueberry and avocado isolates of Dactylonectria macrodidyma, D. novozelandica, D. pauciseptata, and D. anthuriicola caused significant root rot but not stunting within 5 to 9 weeks of inoculation. An isolate of an Ilyonectria sp. from grapevine closely related to Ilyonectria liriodendri, and avocado isolates of Cylindrocladiella pseudoinfestans, Gliocladiopsis peggii, and an Ilyonectria sp. were not pathogenic to avocado.

Isolation and characterization of highly pathogenic avian influenza virus subtype H5N1 from donkeys

Science.gov (United States)

2010-01-01

Background The highly pathogenic H5N1 is a major avian pathogen that crosses species barriers and seriously affects humans as well as some mammals. It mutates in an intensified manner and is considered a potential candidate for the possible next pandemic with all the catastrophic consequences. Methods Nasal swabs were collected from donkeys suffered from respiratory distress. The virus was isolated from the pooled nasal swabs in specific pathogen free embryonated chicken eggs (SPF-ECE). Reverse transcriptase polymerase chain reaction (RT-PCR) and sequencing of both haemagglutingin and neuraminidase were performed. H5 seroconversion was screened using haemagglutination inhibition (HI) assay on 105 donkey serum samples. Results We demonstrated that H5N1 jumped from poultry to another mammalian host; donkeys. Phylogenetic analysis showed that the virus clustered within the lineage of H5N1 from Egypt, closely related to 2009 isolates. It harboured few genetic changes compared to the closely related viruses from avian and humans. The neuraminidase lacks oseltamivir resistant mutations. Interestingly, HI screening for antibodies to H5 haemagglutinins in donkeys revealed high exposure rate. Conclusions These findings extend the host range of the H5N1 influenza virus, possess implications for influenza virus epidemiology and highlight the need for the systematic surveillance of H5N1 in animals in the vicinity of backyard poultry units especially in endemic areas. PMID:20398268

Modes of Action of Microbially-Produced Phytotoxins

Science.gov (United States)

Duke, Stephen O.; Dayan, Franck E.

2011-01-01

Some of the most potent phytotoxins are synthesized by microbes. A few of these share molecular target sites with some synthetic herbicides, but many microbial toxins have unique target sites with potential for exploitation by the herbicide industry. Compounds from both non-pathogenic and pathogenic microbes are discussed. Microbial phytotoxins with modes of action the same as those of commercial herbicides and those with novel modes of action of action are covered. Examples of the compounds discussed are tentoxin, AAL-toxin, auscaulitoxin aglycone, hydantocidin, thaxtomin, and tabtoxin. PMID:22069756

Characterization of Low Pathogenic Avian Influenza Virus Subtype H9N2 Isolated from Free-Living Mynah Birds (Acridotheres tristis) in the Sultanate of Oman.

Science.gov (United States)

Body, Mohammad H; Alrarawahi, Abdulmajeed H; Alhubsy, Saif S; Saravanan, Nirmala; Rajmony, Sunil; Mansoor, Muhammad Khalid

2015-06-01

A low pathogenic avian influenza virus was identified from free-living birds (mynah, Acridotheres tristis) of the starling family. Virus was isolated by inoculation of homogenized suspension from lung, tracheal, spleen, and cloacal swabs into the allantoic cavity of embryonated chicken eggs. Subtype of the isolate was characterized as H9N2 by hemagglutination inhibition test using monospecific chicken antisera to a wide range of influenza reference strain. Pathogenicity of the isolate was determined by intravenous pathogenicity index. The virus was reisolated from experimentally infected chicken. Additionally, the isolate was subjected to reverse transcriptase PCR using partial hemagglutinin (HA) gene-specific primers and yielded an amplicon of 487 bp. HA gene sequence analysis revealed 99% sequence homology among mynah and chicken isolates from Oman. On phylogenetic analysis, isolates from mynah (A/mynnah/Oman/AIVS6/2005) and chicken (A/chicken/Oman/AIVS3/2006; A/chicken/Oman/AIVS7/2006) clustered together tightly, indicating these free-flying birds may be a source of introduction of H9N2 subtype in poultry bird in Oman. Moreover, the HA gene of H9N2 isolates from Oman resembled those of viruses of the G1-like lineage and were very similar to those from United Arab Emirates.

Distinct Trajectories of Massive Recent Gene Gains and Losses in Populations of a Microbial Eukaryotic Pathogen.

Science.gov (United States)

Hartmann, Fanny E; Croll, Daniel

2017-11-01

Differences in gene content are a significant source of variability within species and have an impact on phenotypic traits. However, little is known about the mechanisms responsible for the most recent gene gains and losses. We screened the genomes of 123 worldwide isolates of the major pathogen of wheat Zymoseptoria tritici for robust evidence of gene copy number variation. Based on orthology relationships in three closely related fungi, we identified 599 gene gains and 1,024 gene losses that have not yet reached fixation within the focal species. Our analyses of gene gains and losses segregating in populations showed that gene copy number variation arose preferentially in subtelomeres and in proximity to transposable elements. Recently lost genes were enriched in virulence factors and secondary metabolite gene clusters. In contrast, recently gained genes encoded mostly secreted protein lacking a conserved domain. We analyzed the frequency spectrum at loci segregating a gene presence-absence polymorphism in four worldwide populations. Recent gene losses showed a significant excess in low-frequency variants compared with genome-wide single nucleotide polymorphism, which is indicative of strong negative selection against gene losses. Recent gene gains were either under weak negative selection or neutral. We found evidence for strong divergent selection among populations at individual loci segregating a gene presence-absence polymorphism. Hence, gene gains and losses likely contributed to local adaptation. Our study shows that microbial eukaryotes harbor extensive copy number variation within populations and that functional differences among recently gained and lost genes led to distinct evolutionary trajectories. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Assessment of Shiga toxin-producing Escherichia coli isolates from wildlife meat as potential pathogens for humans.

Science.gov (United States)

Miko, Angelika; Pries, Karin; Haby, Sabine; Steege, Katja; Albrecht, Nadine; Krause, Gladys; Beutin, Lothar

2009-10-01

A total of 140 Shiga toxin-producing Escherichia coli (STEC) strains from wildlife meat (deer, wild boar, and hare) isolated in Germany between 1998 and 2006 were characterized with respect to their serotypes and virulence markers associated with human pathogenicity. The strains grouped into 38 serotypes, but eight O groups (21, 146, 128, 113, 22, 88, 6, and 91) and four H types (21, 28, 2, and 8) accounted for 71.4% and 75.7% of all STEC strains from game, respectively. Eighteen of the serotypes, including enterohemorrhagic E. coli (EHEC) O26:[H11] and O103:H2, were previously found to be associated with human illness. Genes linked to high-level virulence for humans (stx(2), stx(2d), and eae) were present in 46 (32.8%) STEC strains from game. Fifty-four STEC isolates from game belonged to serotypes which are frequently found in human patients (O103:H2, O26:H11, O113:H21, O91:H21, O128:H2, O146:H21, and O146:H28). These 54 STEC isolates were compared with 101 STEC isolates belonging to the same serotypes isolated from farm animals, from their food products, and from human patients. Within a given serotype, most STEC strains were similar with respect to their stx genotypes and other virulence attributes, regardless of origin. The 155 STEC strains were analyzed for genetic similarity by XbaI pulsed-field gel electrophoresis. O103:H2, O26:H11, O113:H21, O128:H2, and O146:H28 STEC isolates from game were 85 to 100% similar to STEC isolates of the same strains from human patients. By multilocus sequence typing, game EHEC O103:H2 strains were attributed to a clonal lineage associated with hemorrhagic diseases in humans. The results from our study indicate that game animals represent a reservoir for and a potential source of human pathogenic STEC and EHEC strains.

Assessment of Shiga Toxin-Producing Escherichia coli Isolates from Wildlife Meat as Potential Pathogens for Humans▿

Science.gov (United States)

Miko, Angelika; Pries, Karin; Haby, Sabine; Steege, Katja; Albrecht, Nadine; Krause, Gladys; Beutin, Lothar

2009-01-01

A total of 140 Shiga toxin-producing Escherichia coli (STEC) strains from wildlife meat (deer, wild boar, and hare) isolated in Germany between 1998 and 2006 were characterized with respect to their serotypes and virulence markers associated with human pathogenicity. The strains grouped into 38 serotypes, but eight O groups (21, 146, 128, 113, 22, 88, 6, and 91) and four H types (21, 28, 2, and 8) accounted for 71.4% and 75.7% of all STEC strains from game, respectively. Eighteen of the serotypes, including enterohemorrhagic E. coli (EHEC) O26:[H11] and O103:H2, were previously found to be associated with human illness. Genes linked to high-level virulence for humans (stx2, stx2d, and eae) were present in 46 (32.8%) STEC strains from game. Fifty-four STEC isolates from game belonged to serotypes which are frequently found in human patients (O103:H2, O26:H11, O113:H21, O91:H21, O128:H2, O146:H21, and O146:H28). These 54 STEC isolates were compared with 101 STEC isolates belonging to the same serotypes isolated from farm animals, from their food products, and from human patients. Within a given serotype, most STEC strains were similar with respect to their stx genotypes and other virulence attributes, regardless of origin. The 155 STEC strains were analyzed for genetic similarity by XbaI pulsed-field gel electrophoresis. O103:H2, O26:H11, O113:H21, O128:H2, and O146:H28 STEC isolates from game were 85 to 100% similar to STEC isolates of the same strains from human patients. By multilocus sequence typing, game EHEC O103:H2 strains were attributed to a clonal lineage associated with hemorrhagic diseases in humans. The results from our study indicate that game animals represent a reservoir for and a potential source of human pathogenic STEC and EHEC strains. PMID:19700552

Phylogenetic analysis, fumonisin production and pathogenicity of Fusarium fujikuroi strains isolated from rice in the Philippines.

Science.gov (United States)

Cruz, Alejandra; Marín, Patricia; González-Jaén, M Teresa; Aguilar, Kristel Grace I; Cumagun, Christian Joseph R

2013-09-01

Fusarium fujikuroi Nirenberg is a maize and rice pathogen causing important agricultural losses and produces fumonisins - mycotoxins which pose health risk to humans and farm animals. However, little information is available about the phylogenetics of this species and its ability to produce fumonisins in rice. We studied 32 strains isolated from rice in the Philippines and performed a phylogenetic analysis using the partial sequence of Elongation Factor 1 alpha (EF-1α) including isolates belonging to closely related species. Fumonisin B1 (FB1 ) production was analyzed in 7-day-old cultures grown in fumonisin-inducing medium by an enzyme-linked immunosorbent assay-based method and by real-time reverse transcriptase-polymerase chain reaction using primers for FUM1 gene, a key gene in fumonisin biosynthesis. Nucleotide diversities per site (π) were 0.00024 ± 0.00022 (standard deviation) for the 32 F. fujikuroi strains from the Philippines and 0.00189 ± 0.00143 for all 34 F. fujikuroi strains, respectively. F. fujikuroi isolates grouped into one cluster separated from the rest of isolates belonging to the closely related F. proliferatum and showed very low variability, irrespective of their geographic origin. The cluster containing strains of F. proliferatum showed higher intraspecific variability than F. fujikuroi. Thirteen of the 32 strains analyzed were FB1 producers (40.62%), with production ranging from 0.386 to 223.83 ppm. All isolates analyzed showed FUM1 gene expression above 1 and higher than the CT value of the non-template control sample. Both seedling stunting and elongation were induced by the isolates in comparison with the control. F. fujikuroi are distinct from F. proliferatum isolates based on phytogenetic analysis and are potential fumonisin producers because all are positive for FUM1 gene expression. No relationship between fumonisin production and pathogenicity could be observed. © 2013 Society of Chemical Industry.

CheckM: assessing the quality of microbial genomes recovered from isolates, single cells, and metagenomes

Science.gov (United States)

Parks, Donovan H.; Imelfort, Michael; Skennerton, Connor T.; Hugenholtz, Philip; Tyson, Gene W.

2015-01-01

Large-scale recovery of genomes from isolates, single cells, and metagenomic data has been made possible by advances in computational methods and substantial reductions in sequencing costs. Although this increasing breadth of draft genomes is providing key information regarding the evolutionary and functional diversity of microbial life, it has become impractical to finish all available reference genomes. Making robust biological inferences from draft genomes requires accurate estimates of their completeness and contamination. Current methods for assessing genome quality are ad hoc and generally make use of a limited number of “marker” genes conserved across all bacterial or archaeal genomes. Here we introduce CheckM, an automated method for assessing the quality of a genome using a broader set of marker genes specific to the position of a genome within a reference genome tree and information about the collocation of these genes. We demonstrate the effectiveness of CheckM using synthetic data and a wide range of isolate-, single-cell-, and metagenome-derived genomes. CheckM is shown to provide accurate estimates of genome completeness and contamination and to outperform existing approaches. Using CheckM, we identify a diverse range of errors currently impacting publicly available isolate genomes and demonstrate that genomes obtained from single cells and metagenomic data vary substantially in quality. In order to facilitate the use of draft genomes, we propose an objective measure of genome quality that can be used to select genomes suitable for specific gene- and genome-centric analyses of microbial communities. PMID:25977477

Resistance among Gram-negative ESKAPE pathogens isolated from hospitalized patients with intra-abdominal and urinary tract infections in Latin American countries: SMART 2013-2015.

Science.gov (United States)

Karlowsky, James A; Hoban, Daryl J; Hackel, Meredith A; Lob, Sibylle H; Sahm, Daniel F

Gram-negative ESKAPE pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are important etiologic agents of nosocomial infection that are frequently resistant to broad-spectrum antimicrobial agents. Gram-negative ESKAPE pathogens were collected from hospitalized patients in 11 Latin American countries from 2013 to 2015 as part of the Study for Monitoring Antimicrobial Resistance Trends (SMART) global surveillance program. In total, 2113 isolates from intra-abdominal infections (IAI) and 970 isolates from urinary tract infections (UTI) were tested against antimicrobial agents using standardized CLSI broth microdilution methodology. Of the agents tested, amikacin demonstrated the highest rates of susceptibility (%) for K. pneumoniae (92.2, 92.3), Enterobacter spp. (97.5, 92.1), and P. aeruginosa (85.3, 75.2) isolates from both IAI and UTI, respectively. Ertapenem (68.5, 62.6) and imipenem (79.2, 75.9) showed substantially higher rates of susceptibility (%) than other β-lactams, including piperacillin-tazobactam (35.9, 37.4) against ESBL-positive isolates of K. pneumoniae from IAI and UTI, respectively. Rates of susceptibility to all agents tested against A. baumannii were ≤30.9%. Gram-negative ESKAPE pathogens isolated from Latin America demonstrated compromised in vitro susceptibility to commonly prescribed broad-spectrum, parenteral antimicrobial agents. Continued surveillance is warranted. New antimicrobial agents with potent activity against Gram-negative ESKAPE pathogens are urgently needed. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

Methylobacteria isolated from bryophytes and the 2-fold description of the same microbial species

OpenAIRE

Schauer, S.; Kutschera, U.

2013-01-01

On the surface of healthy land plants (embryophytes), numerous non-pathogenic bacteria have been discovered and described. Among these epiphytic microbes, pink-pigmented facultative methylotrophic microbes of the genus Methylobacterium are of special significance, because these microorganisms consume methanol emitted via the stomatal pores and secrete growth-promoting phytohormones. Methylobacterium funariae, Schauer and Kutschera 2011, a species isolated in our lab from the common cord moss,...

Resistance among Gram-negative ESKAPE pathogens isolated from hospitalized patients with intra-abdominal and urinary tract infections in Latin American countries: SMART 2013–2015

Directory of Open Access Journals (Sweden)

James A. Karlowsky

2017-05-01

Full Text Available Gram-negative ESKAPE pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species are important etiologic agents of nosocomial infection that are frequently resistant to broad-spectrum antimicrobial agents. Gram-negative ESKAPE pathogens were collected from hospitalized patients in 11 Latin American countries from 2013 to 2015 as part of the Study for Monitoring Antimicrobial Resistance Trends (SMART global surveillance program. In total, 2113 isolates from intra-abdominal infections (IAI and 970 isolates from urinary tract infections (UTI were tested against antimicrobial agents using standardized CLSI broth microdilution methodology. Of the agents tested, amikacin demonstrated the highest rates of susceptibility (% for K. pneumoniae (92.2, 92.3, Enterobacter spp. (97.5, 92.1, and P. aeruginosa (85.3, 75.2 isolates from both IAI and UTI, respectively. Ertapenem (68.5, 62.6 and imipenem (79.2, 75.9 showed substantially higher rates of susceptibility (% than other β-lactams, including piperacillin-tazobactam (35.9, 37.4 against ESBL-positive isolates of K. pneumoniae from IAI and UTI, respectively. Rates of susceptibility to all agents tested against A. baumannii were ≤30.9%. Gram-negative ESKAPE pathogens isolated from Latin America demonstrated compromised in vitro susceptibility to commonly prescribed broad-spectrum, parenteral antimicrobial agents. Continued surveillance is warranted. New antimicrobial agents with potent activity against Gram-negative ESKAPE pathogens are urgently needed.

Effect of an essential oil-containing dentifrice on dental plaque microbial composition.

Science.gov (United States)

Charles, C H; Vincent, J W; Borycheski, L; Amatnieks, Y; Sarina, M; Qaqish, J; Proskin, H M

2000-09-01

To determine the effect of 6 months use of an essential oil-containing (EO) antiplaque/antigingivitis fluoride dentifrice on the balance of the oral microbial flora and on the emergence of resistant microbial forms by analysis of dental plaque and saliva. The dentifrice essential oils consisted of a fixed combination of thymol, menthol, methyl salicylate, and eucalyptol. An identical fluoride-containing dentifrice without the essential oils served as the control. A subgroup of 66 subjects from a clinical trial population of 321 was randomly selected for characterization of their dental plaque microflora. Saliva was also cultured to monitor for the emergence of opportunistic pathogens. Supragingival plaque and saliva were harvested at baseline, after which subjects received a dental prophylaxis. Subjects were sampled again after 3 and 6 months of product use prior to clinical examination. Plaque was characterized for microbial content by phase contrast microscopy for recognizable cellular morphotypes and by cultivation on nonselective and selective culture media. Determination of the minimum inhibitory concentrations of the test agent against selected Actinomyces and Veillonella isolated bacterial species was conducted at all time points to monitor for the potential development of bacterial resistance. There were no statistically significant differences between the microbial flora obtained from subjects using the essential oil-containing dentifrice and the vehicle control for all parameters and time periods except for the percentage of spirochetes at 6 months and for percentage of "other" microorganisms at 3 months. The EO group exhibited a lower adjusted mean for both parameters. Additionally, there was no evidence of the development of bacterial resistance to the antimicrobial activity of the essential oils or the emergence of opportunistic pathogens.

Antimicrobial activity of Algerian honey on subclinical mastitis pathogens isolated from goat's milk

Directory of Open Access Journals (Sweden)

A. Bourabah

2014-04-01

Full Text Available Aim: The aim of the present study was to determine the susceptibility of subclinical mastitis pathogens isolated from goat's milk and to evaluate the antimicrobial activity of Algerian honey on mastitis causing bacteria. Materials and Methods: The antibacterial activity against the isolated bacteria was evaluated by determining the Minimal Inhibitory Concentration (MIC, using the agar incorporation method. Results: The results showed that both Micrococcus spp. and Klebsiella spp. were susceptible to Streptomycin and tetracycline, while Pseudomonas aeruginosa, E coli, Enterobacter spp., Bacillus spp., and Coagulase Negative Staphyloccoci (CNS were preferentially susceptible to Streptomycin. However, Streptococcus D was the most resistant to the tested antibiotics whereas Staphylococcus aureus was the most susceptible to all the studied antibiotics. As regards to the antimicrobial activity of honey, the measured values were comprised between 11 and 14%. Conclusion: The results reveal that antimicrobial drugs susceptibility tests in goat subclinical mastitis might be necessary before the treatment. Algerian honey exhibited in vitro antimicrobial activity against different isolated bacteria in goat mastitis.

Antimicrobial Susceptibility Monitoring of Bacterial Pathogens Isolated from Urinary Tract Infections in Dogs and Cats Across Europe: ComPath Results.

Science.gov (United States)

Moyaert, Hilde; Morrissey, Ian; de Jong, Anno; El Garch, Farid; Klein, Ulrich; Ludwig, Carolin; Thiry, Julien; Youala, Myriam

2017-04-01

ComPath is a pan-European antimicrobial surveillance program collecting bacterial pathogens from dogs and cats not recently exposed to antimicrobials. We present minimum inhibitory concentration data obtained using Clinical and Laboratory Standards Institute methodology for 616 urinary tract infection (UTI) isolates collected between 2008 and 2010. In both dogs and cats, the most common pathogen was Escherichia coli (59.8% and 46.7%, respectively). Antimicrobial activity against E. coli in dogs and cats was similar with fluoroquinolone and trimethoprim/sulfamethoxazole susceptibility >90%. Ampicillin susceptibility was ∼80%. Staphylococcus intermedius Group isolates from dogs (67/437, 15.3%) had high antimicrobial susceptibility (>90%) toward beta-lactams, fluoroquinolones, and trimethoprim/sulfamethoxazole. Four canine isolates (6%) were oxacillin resistant, and harbored mecA. Proteus mirabilis from dogs (48/437, 11.0%) had high antimicrobial susceptibility (∼90%) to amoxicillin/clavulanic acid, enrofloxacin, and marbofloxacin and slightly lower susceptibility (∼80-85%) to ampicillin and orbifloxacin. Streptococcus canis isolates (35/437, 8.0%) from dogs were all susceptible to ampicillin and amoxicillin/clavulanic acid and >90% susceptible to marbofloxacin. Although resistance was not observed, high intermediate susceptibility was seen for both enrofloxacin (28.6%) and orbifloxacin (85.7%). Overall, antimicrobial in vitro activity appears to be high in UTI pathogens from dogs and cats with low multidrug resistance, although a lack of specific dog and cat breakpoints for important antimicrobials such as cefovecin, cephalexin, and ibafloxacin prevents analysis of susceptibility for these agents.

Plant Pathogenicity in Spaceflight Environments

OpenAIRE

Bishop, Deborah L.; Levine, Howard G.; Anderson, Anne J.

1996-01-01

Plants grown in microgravity are subject to many environmental stresses, which may promote microbial growth and result in pathogenicity to the plant. Recent plant experiments with super dwarf wheat aboard the NASA Space Shuttle and NASA/Russian Mir Space Station returned from the mission with severe degrees of fungal contamination. Understanding the cause of such microbial contamination and methods to eliminate it are necessary prerequisites for continued plant growth and development studies ...

Phenotypic Variation Is Almost Entirely Independent of the Host-Pathogen Relationship in Clinical Isolates of S. aureus.

Directory of Open Access Journals (Sweden)

Adrian D Land

Full Text Available A key feature of Staphylococcus aureus biology is its ability to switch from an apparently benign colonizer of ~30% of the population to a cutaneous pathogen, to a deadly invasive pathogen. Little is known about the mechanisms driving this transition or the propensity of different S. aureus strains to engender different types of host-pathogen interactions. At the same time, significant weight has been given to the role of specific in vitro phenotypes in S. aureus virulence. Biofilm formation, hemolysis and pigment formation have all been associated with virulence in mice.To determine if there is a correlation between in vitro phenotype and the three types of host-pathogen relationships commonly exhibited by S. aureus in the context of its natural human host, we assayed 300 clinical isolates for phenotypes implicated in virulence including hemolysis, sensitivity to autolysis, and biofilm formation. For comparative purposes, we also assayed phenotype in 9 domesticated S. aureus strains routinely used for analysis of virulence determinants in laboratory settings.Strikingly, the clinical strains exhibited significant phenotypic uniformity in each of the assays evaluated in this study. One exception was a small, but significant, correlation between an increased propensity for biofilm formation and isolation from skin and soft tissue infections (SSTIs. In contrast, we observed a high degree of phenotypic variation between common laboratory strains that exhibit virulence in mouse models. These data suggest the existence of significant evolutionary pressure on the S. aureus genome and highlight a role for host factors as a strong determinant of the host-pathogen relationship. In addition, the high degree of variation between laboratory strains emphasizes the need for caution when applying data obtained in one lab strain to the analysis of another.

Microbial contamination of the Tzu-Chi Cord Blood Bank from 2005 to 2006.

Science.gov (United States)

Chen, Shu-Huey; Zheng, Ya-Jun; Yang, Shang-Hsien; Yang, Kuo-Liang; Shyr, Ming-Hwang; Ho, Yu-Huai

2008-01-01

In total, 4502 units of cord blood (CB) were collected during a 2-year period from 2005 to 2006 by the Buddhist Tzu-Chi Stem Cells Center. The aim of this study was to analyze the incidence of microbial contamination and type of organism present in the cord blood. The clinical impact of microbial contamination on hematopoietic progenitor cell (HPC) grafts used for HPC transplantation is also discussed. First and second specimens were obtained for microbial assessment. These were collected in laboratory after cord blood collection and after cord blood unit manipulation, respectively. The samples were cultured and the results reviewed. The overall incidence of microbiological contamination was 1.8% (82/4502). Three CB units were contaminated with two different organisms. Infectious organisms comprised 9.4% (8/85) of total isolated microbes. These infectious microorganisms were beta-Streptococci group B, Candida tropicalis and Staphylococcus aureus which were isolated in 6, 1 and 1 of CB units respectively. Escherichia coli, Bacteroides fragilis, Lactobacillus spp., Enterococcus, beta-Streptococcus Group B, Bacteroides valgatus, Corynebacterium spp., Klebsiella pneumonia and Peptococcus spp. were the most frequently encountered microorganisms. A higher contamination rate of the CB units was noted after vaginal delivery (2.16%) compared to caesarian section (0.85%) (p bank, we use a closed system but an in utero method. Similar to other studies, most of microorganisms reported here as contaminants are non-pathogenic.

Microbial genome-enabled insights into plant-microorganism interactions.

Science.gov (United States)

Guttman, David S; McHardy, Alice C; Schulze-Lefert, Paul

2014-12-01

Advances in genome-based studies on plant-associated microorganisms have transformed our understanding of many plant pathogens and are beginning to greatly widen our knowledge of plant interactions with mutualistic and commensal microorganisms. Pathogenomics has revealed how pathogenic microorganisms adapt to particular hosts, subvert innate immune responses and change host range, as well as how new pathogen species emerge. Similarly, culture-independent community profiling methods, coupled with metagenomic and metatranscriptomic studies, have provided the first insights into the emerging field of research on plant-associated microbial communities. Together, these approaches have the potential to bridge the gap between plant microbial ecology and plant pathology, which have traditionally been two distinct research fields.

Antimicrobial susceptibility survey of pathogens isolated from selected patients in Northern Italy

Directory of Open Access Journals (Sweden)

Elisabetta Maioli

2005-03-01

Full Text Available The Clinical Microbiology Laboratory of the University of Genoa participated, during the year 2003, in an international antimicrobial surveillance program.The collection of isolates was done according to the site of infection and/or type of patient. Four hundred twenty (420 clinical isolates were analyzed during this year and the frequencies of the different pathogens were investigated. A reference centre carried out susceptibility tests. Oxacillin-resistant Staphylococcus aureus represented 47.6% of all S. aureus isolates from blood stream infections and 33.3% of all S. aureus isolated from skin and soft tissue infections in hospitalised patients.These strains showed resistance to most of the antimicrobial agents evaluated, except vancomycin, teicoplanin, quinupristin/dalfopristin and linezolid which registered 100% of susceptibility. Some isolates from blood stream infections such as E. coli demonstrated resistance to ciprofloxacin (23.3%, levofloxacin (20%, and gatifloxacin (16.6%, and Klebsiella pneumoniae was resistant (18% to all fluoroquinolones tested. Pseudomonas aeruginosa manifested resistance to ciprofloxacin (16.6%, while 27.7% of these strains were resistant both to levofloxacin and gatifloxacin. All the Enterobacter cloacae isolated from blood were susceptible to ciprofloxacin, levofloxacin and gatifloxacin. Haemophilus influenzae and Moraxella catarrhalis collected from community-acquired respiratory tract infections were all inhibited by ciprofloxacin, levofloxacin and gatifloxacin. E. coli isolated from urinary tract infections in hospitalised patients were resistant to ciprofloxacin, levofloxacin and gatifloxacin (2.7%. All Salmonella spp. collected from samples of patients affected by infections of the gastro-intestinal tract were susceptible to all fluoroquinolones. Penicillin resistance in Streptococcus pneumoniae was found in 21.4% of isolates from patients with respiratory tract infections. Fluoroquinolone resistance was

Genome characterization, antigenicity and pathogenicity of a novel infectious bronchitis virus type isolated from south China.

Science.gov (United States)

Jiang, Lei; Zhao, Wenjun; Han, Zongxi; Chen, Yuqiu; Zhao, Yan; Sun, Junfeng; Li, Huixin; Shao, Yuhao; Liu, Liangliang; Liu, Shengwang

2017-10-01

In 2014, three infectious bronchitis virus (IBV) strains, designated as γCoV/ck/China/I0111/14, γCoV/ck/China/I0114/14 and γCoV/ck/China/I0118/14, were isolated and identified from chickens suspected to be infected with IBV in Guangxi province, China. Based upon data arising from S1 sequence and phylogenetic analyses, the three IBV isolates were genetically different from other known IBV types, which represented a novel genotype (GI-29). Virus cross-neutralization tests, using γCoV/ck/China/I0111/14 as a representative, showed that genotype GI-29 was antigenically different from all other known IBV types, thus representing a novel serotype. Complete genomic analysis showed that GI-29 type viruses were closely related to and might originate from a GX-YL5-like virus by accumulation of substitutions in multiple genes. These GI-29 viral genomes are still evolving and diverging, particularly in the 3' region, although we cannot rule out the possibility of recombination events occurring. For isolate γCoV/ck/China/I0114/14, we found that recombination events had occurred between nsps 2 and 3 in gene 1 which led to the introduction of a 4/91 gene fragment into the γCoV/ck/China/I0114/14 viral genome. In addition, we found that the GI-29 type γCoV/ck/China/I0111/14 isolate was a nephropathogenic strain and high pathogenic to 1-day-old specific pathogen-free (SPF) chickens although cystic oviducts were not observed in the surviving layer chickens challenged with γCoV/ck/China/I0111/14 isolate. Copyright © 2017 Elsevier B.V. All rights reserved.

Viral pathogen discovery

Science.gov (United States)

Chiu, Charles Y

2015-01-01

Viral pathogen discovery is of critical importance to clinical microbiology, infectious diseases, and public health. Genomic approaches for pathogen discovery, including consensus polymerase chain reaction (PCR), microarrays, and unbiased next-generation sequencing (NGS), have the capacity to comprehensively identify novel microbes present in clinical samples. Although numerous challenges remain to be addressed, including the bioinformatics analysis and interpretation of large datasets, these technologies have been successful in rapidly identifying emerging outbreak threats, screening vaccines and other biological products for microbial contamination, and discovering novel viruses associated with both acute and chronic illnesses. Downstream studies such as genome assembly, epidemiologic screening, and a culture system or animal model of infection are necessary to establish an association of a candidate pathogen with disease. PMID:23725672

Effect Of Spaceflight On Microbial Gene Expression And Virulence: Preliminary Results From Microbe Payload Flown On-Board STS-115

Science.gov (United States)

Wilson, J. W.; HonerzuBentrup, K,; Schurr, M. J.; Buchanan, K.; Morici, L.; Hammond, T.; Allen, P.; Baker, C.; Ott, C. M.; Nelman-Gonzalez M.;

An evaluation of indices for quantifying tuberculosis transmission using genotypes of pathogen isolates

Directory of Open Access Journals (Sweden)

Phong Renault

2006-06-01

Full Text Available Abstract Background Infectious diseases are often studied by characterising the population structure of the pathogen using genetic markers. An unresolved problem is the effective quantification of the extent of transmission using genetic variation data from such pathogen isolates. Methods It is important that transmission indices reflect the growth of the infectious population as well as account for the mutation rate of the marker and the effects of sampling. That is, while responding to this growth rate, indices should be unresponsive to the sample size and the mutation rate. We use simulation methods taking into account both the mutation and sampling processes to evaluate indices designed to quantify transmission of tuberculosis. Results Previously proposed indices generally perform inadequately according to the above criteria, with the partial exception of the recently proposed Transmission-Mutation Index. Conclusion Any transmission index needs to take into account mutation of the marker and the effects of sampling. Simple indices are unlikely to capture the full complexity of the underlying processes.

Comparison of pathogenic domains of rabies and African rabies-related lyssaviruses and pathogenicity observed in mice

Directory of Open Access Journals (Sweden)

Joe Kgaladi

2013-03-01

Full Text Available Several lyssavirus species occur in Africa (Rabies virus, Lagos bat virus, Mokola virus, Duvenhage virus, Shimoni bat virus and Ikoma lyssavirus, displaying a high sequence diversity between isolates belonging to the same species. There is limited information about comparative pathogenesis of these African lyssaviruses and this precludes authoritative opinion on the potential public and veterinary health impact. In this study, an analysis of representative African lyssaviruses attempted to correlate viral genomic sequence similarities and differences with the corresponding pathogenic profiles observed in mice. The study demonstrated that the virus isolates evaluated could be lethal to mice when introduced intramuscularly and that different isolates of the same lyssavirus species differ in their virulence. Using real-time polymerase chain reaction (PCR, viral RNA was detected in brain tissue, but no viral RNA was detected in the salivary glands or blood of mice that succumbed to infection. Comparison of known pathogenic domains indicated that pathogenicity is likely to be dependent on multiple domains. Cumulatively, our results re-emphasised the realisation that the pathogenicity of a lyssavirus species cannot be deduced based on studies of only a single isolate of the species or a single pathogenic domain.

Pattern of Bacterial Pathogens and Their Susceptibility Isolated from Surgical Site Infections at Selected Referral Hospitals, Addis Ababa, Ethiopia

Directory of Open Access Journals (Sweden)

Walelign Dessie

2016-01-01

Full Text Available Background. The emergence of multidrug resistant bacterial pathogens in hospitals is becoming a challenge for surgeons to treat hospital acquired infections. Objective. To determine bacterial pathogens and drug susceptibility isolated from surgical site infections at St. Paul Specialized Hospital Millennium Medical College and Yekatit 12 Referral Hospital Medical College, Addis Ababa, Ethiopia. Methods. A cross-sectional study was conducted between October 2013 and March 2014 on 107 surgical site infected patients. Wound specimens were collected using sterile cotton swab and processed as per standard operative procedures in appropriate culture media; and susceptibility testing was done using Kirby-Bauer disc diffusion technique. The data were analyzed by using SPSS version 20. Result. From a total of 107 swabs collected, 90 (84.1% were culture positive and 104 organisms were isolated. E. coli (24 (23.1% was the most common organism isolated followed by multidrug resistant Acinetobacter species (23 (22.1%. More than 58 (75% of the Gram negative isolates showed multiple antibiotic resistance (resistance ≥ 5 drugs. Pan-antibiotic resistance was noted among 8 (34.8% Acinetobacter species and 3 (12.5% E. coli. This calls for abstinence from antibiotic abuse. Conclusion. Gram negative bacteria were the most important isolates accounting for 76 (73.1%. Ampicillin, amoxicillin, penicillin, cephazoline, and tetracycline showed resistance while gentamicin and ciprofloxacin were relatively effective antimicrobials.

Characterisation of a highly pathogenic H5N1 clade 2.3.2 influenza virus isolated from swans in Shanghai, China.

Science.gov (United States)

Zhao, Guo; Zhong, Lei; Lu, Xinlun; Hu, Jiao; Gu, Xiaobing; Kai, Yan; Song, Qingqing; Sun, Qing; Liu, Jinbao; Peng, Daxin; Wang, Xiaoquan; Liu, Xiaowen; Liu, Xiufan

2012-02-01

In spring 2009, one strain of H5N1 clade 2.3.2 virus was isolated from wild swans in Shanghai, indicating the importance of the wild swan in the ecology of this highly pathogenic avian influenza virus (HPAIV) in Eastern China. Pathogenicity experiments conducted in this study indicated that the virus was highly pathogenic for chickens but lowly pathogenic for mammalian hosts, as evidenced by reduced infection of mice. The analysis of complete genome sequences and genetic evolution showed that A/Swan/Shanghai/10/09 (SW/SH/09) may be derived from the strain A/silky chicken/Shantou/475/2004 (CK/ST/04), which is homologous to the influenza viruses isolated from chicken, duck, pika, little egret, swan, mandarin duck and bar-headed goose in China Hunan, China Qinghai, Mongolia, Russia, Japan, Korea, Laos and Hong Kong during 2007-2011, indicating that the virus has retro-infected diverse wild birds from chicken, and significant spread of the virus is still ongoing through overlapping migratory flyways. On the basis of the molecular analysis, we also found that there was a deletion of the glycosylation site (NSS) in amino acid 156 of the hemagglutinin (HA) protein when compared with that of the other Clade 2.3.2 viruses isolated between 2007 and 2011. More importantly, the sequence analysis of SW/SH/09 virus displayed the drug-resistant mutations on the matrix protein (M2) and neuraminidase (NA) genes.

Genome sequence of vibrio cholerae G4222, a South African clinical isolate

CSIR Research Space (South Africa)

Le Rouw, Wouter J

2013-03-01

Full Text Available of Microbiology and Plant Pathology, University of Pretoria, South Africab; Center for Microbial Ecology and Genomics, Department of Genetics, University of Pretoria, South Africac Vibrio cholerae, a Gram-negative pathogen autochthonous to the aquatic environment..., is the causative agent of cholera. Here, we report the complete genome sequence of V. choleraeG4222, a clinical isolate from South Africa. Received 17 January 2013 Accepted 8 February 2013 Published 14 March 2013 Citation le Roux WJ, Chan WY, De Maayer P, Venter SN...

Evaluation of the egg transmission and pathogenicity of Mycoplasma gallisepticum isolates genotyped as ts-11.

Science.gov (United States)

Armour, Natalie K; Ferguson-Noel, Naola

2015-01-01

Live Mycoplasma gallisepticum vaccines are used for the control of respiratory disease, egg production losses and egg transmission associated with M. gallisepticum infection in long-lived poultry. The first field case of apparent increased virulence and vertical transmission of ts-11, a live M. gallisepticum vaccine, has been reported. In that study a M. gallisepticum isolate from the broiler progeny of ts-11-vaccinated breeders was genotyped as ts-11 by sequence analysis of four different genetic targets and Random Amplified Polymorphic DNA and found to be significantly more virulent than ts-11 vaccine. The objective of the current study was to evaluate the rate of egg transmission and pathogenicity of ts-11 vaccine and isolates recovered from ts-11-vaccinated breeders (K6222B) and their broiler progeny (K6216D) which had been genotyped as ts-11. Groups of 28-week-old specific pathogen-free chickens at 87% average weekly egg production were inoculated with sterile broth media (negative controls), ts-11 vaccine, K6222B, K6216D or R strain (positive controls) by eye-drop and aerosol. K6216D transmitted via the egg at an average rate of 4.0% in the third and fourth weeks post-infection, while egg transmission of K6222B and ts-11 vaccine was not detected. M. gallisepticum was isolated from the air sacs, ovaries and oviducts of hens infected with K6216D and K6222B, but not from those infected with ts-11 vaccine. K6216D and K6222B both induced respiratory signs and significantly more tracheal colonization and more severe tracheal and air sac lesions than ts-11 vaccine (P ≤ 0.05). There were no substantial differences in the egg production of ts-11, K6216D and K6222B infected groups. These results provide the first conclusive evidence of transovarian transmission of an isolate genotyped as ts-11 and indicate that isolates genotyed as ts-11 vary in their virulence and ability to transmit via the egg.

Characterization of microbial communities and fungal metabolites on field grown strawberries from organic and conventional production

DEFF Research Database (Denmark)

Jensen, Birgit; Knudsen, Inge M. B.; Andersen, Birgitte

2013-01-01

The background levels of culturable indigenous microbial communities (microbiotas) on strawberries were examined in a field survey with four conventional and four organic growers with different production practise and geographic distribution. The microbiota on apparently healthy strawberries...... was complex including potential plant pathogens, opportunistic human pathogens, plant disease biocontrol agents and mycotoxin producers. The latter group was dominated by Penicillium spp. and Aspergillus niger was also isolated. As expected, bacteria were the most abundant and diverse group of the strawberry...... microbiota followed by yeasts and filamentous fungi. No obvious correlation between grower practice and the strawberry microbiota was observed. Differences between microbiotas on strawberries from conventional systems with up to 10 fungicide spray treatments and organic production systems were insignificant...

Brazilian kefir: structure, microbial communities and chemical composition

Directory of Open Access Journals (Sweden)

Karina Teixeira Magalhães

2011-06-01

Full Text Available Microbial ecology and chemical composition of Brazilian kefir beverage was performed. The microorganisms associated with Brazilian kefir were investigated using a combination of phenotypic and genotypic methods. A total of 359 microbial isolates were identified. Lactic acid bacteria (60.5% were the major isolated group identified, followed by yeasts (30.6% and acetic acid bacteria (8.9%. Lactobacillus paracasei (89 isolates, Lactobacillus parabuchneri (41 isolates, Lactobacillus casei (32 isolates, Lactobacillus kefiri (31 isolates, Lactococcus lactis (24 isolates, Acetobacter lovaniensis (32 isolates, Kluyveromyces lactis (31 isolates, Kazachstania aerobia (23 isolates, Saccharomyces cerevisiae (41 isolates and Lachancea meyersii (15 isolates were the microbial species isolated. Scanning electron microscopy showed that the microbiota was dominated by bacilli (short and curved long cells growing in close association with lemon-shaped yeasts cells. During the 24 h of fermentation, the protein content increased, while lactose and fat content decreased. The concentration of lactic acid ranged from 1.4 to 17.4 mg/ml, and that of acetic acid increased from 2.1 to 2.73 mg/ml. The production of ethanol was limited, reaching a final mean value of 0.5 mg/ml.

Brazilian kefir: structure, microbial communities and chemical composition

Science.gov (United States)

Magalhães, Karina Teixeira; de Melo Pereira, Gilberto Vinícius; Campos, Cássia Roberta; Dragone, Giuliano; Schwan, Rosane Freitas

2011-01-01

Microbial ecology and chemical composition of Brazilian kefir beverage was performed. The microorganisms associated with Brazilian kefir were investigated using a combination of phenotypic and genotypic methods. A total of 359 microbial isolates were identified. Lactic acid bacteria (60.5%) were the major isolated group identified, followed by yeasts (30.6%) and acetic acid bacteria (8.9%). Lactobacillus paracasei (89 isolates), Lactobacillus parabuchneri (41 isolates), Lactobacillus casei (32 isolates), Lactobacillus kefiri (31 isolates), Lactococcus lactis (24 isolates), Acetobacter lovaniensis (32 isolates), Kluyveromyces lactis (31 isolates), Kazachstania aerobia (23 isolates), Saccharomyces cerevisiae (41 isolates) and Lachancea meyersii (15 isolates) were the microbial species isolated. Scanning electron microscopy showed that the microbiota was dominated by bacilli (short and curved long) cells growing in close association with lemon-shaped yeasts cells. During the 24 h of fermentation, the protein content increased, while lactose and fat content decreased. The concentration of lactic acid ranged from 1.4 to 17.4 mg/ml, and that of acetic acid increased from 2.1 to 2.73 mg/ml. The production of ethanol was limited, reaching a final mean value of 0.5 mg/ml. PMID:24031681

Linking social and pathogen transmission networks using microbial genetics in giraffe (Giraffa camelopardalis).

Science.gov (United States)

VanderWaal, Kimberly L; Atwill, Edward R; Isbell, Lynne A; McCowan, Brenda

2014-03-01

Although network analysis has drawn considerable attention as a promising tool for disease ecology, empirical research has been hindered by limitations in detecting the occurrence of pathogen transmission (who transmitted to whom) within social networks. Using a novel approach, we utilize the genetics of a diverse microbe, Escherichia coli, to infer where direct or indirect transmission has occurred and use these data to construct transmission networks for a wild giraffe population (Giraffe camelopardalis). Individuals were considered to be a part of the same transmission chain and were interlinked in the transmission network if they shared genetic subtypes of E. coli. By using microbial genetics to quantify who transmits to whom independently from the behavioural data on who is in contact with whom, we were able to directly investigate how the structure of contact networks influences the structure of the transmission network. To distinguish between the effects of social and environmental contact on transmission dynamics, the transmission network was compared with two separate contact networks defined from the behavioural data: a social network based on association patterns, and a spatial network based on patterns of home-range overlap among individuals. We found that links in the transmission network were more likely to occur between individuals that were strongly linked in the social network. Furthermore, individuals that had more numerous connections or that occupied 'bottleneck' positions in the social network tended to occupy similar positions in the transmission network. No similar correlations were observed between the spatial and transmission networks. This indicates that an individual's social network position is predictive of transmission network position, which has implications for identifying individuals that function as super-spreaders or transmission bottlenecks in the population. These results emphasize the importance of association patterns in

Isolation and characterization of highly pathogenic avian influenza virus subtype H5N1 from donkeys

Directory of Open Access Journals (Sweden)

Abdel-Ghany Ahmad E

2010-04-01

Full Text Available Abstract Background The highly pathogenic H5N1 is a major avian pathogen that crosses species barriers and seriously affects humans as well as some mammals. It mutates in an intensified manner and is considered a potential candidate for the possible next pandemic with all the catastrophic consequences. Methods Nasal swabs were collected from donkeys suffered from respiratory distress. The virus was isolated from the pooled nasal swabs in specific pathogen free embryonated chicken eggs (SPF-ECE. Reverse transcriptase polymerase chain reaction (RT-PCR and sequencing of both haemagglutingin and neuraminidase were performed. H5 seroconversion was screened using haemagglutination inhibition (HI assay on 105 donkey serum samples. Results We demonstrated that H5N1 jumped from poultry to another mammalian host; donkeys. Phylogenetic analysis showed that the virus clustered within the lineage of H5N1 from Egypt, closely related to 2009 isolates. It harboured few genetic changes compared to the closely related viruses from avian and humans. The neuraminidase lacks oseltamivir resistant mutations. Interestingly, HI screening for antibodies to H5 haemagglutinins in donkeys revealed high exposure rate. Conclusions These findings extend the host range of the H5N1 influenza virus, possess implications for influenza virus epidemiology and highlight the need for the systematic surveillance of H5N1 in animals in the vicinity of backyard poultry units especially in endemic areas.

Study of the microbial ecology of wild and aquacultured Tunisian fresh fish.

Science.gov (United States)

Boulares, Mouna; Mejri, Lobna; Hassouna, Mnasser

2011-10-01

Eighty samples of fresh fish were collected in Tunisia and analyzed for microbial load. Quality and hygienic safety of the meat and intestines of wild and aquacultured fresh fish were determined. The mesophilic aerobic plate count and populations of psychrotrophic lactic acid bacteria (LAB) and other psychrotrophic bacteria ranged from 5.67 to 7.29, 4.51 to 6, and 5.07 to 6.21 log CFU/g, respectively. For all microbiological determinations, bacterial counts were lower in meat than in the intestines of fresh fish. For all samples lower microbial populations were found in most of the wild fish than in the aquacultured fish. No isolates of the pathogenic genera Salmonella and Listeria were detected in any sample. Among the 160 strains of biopreservative psychrotrophic LAB and the 150 strains of spoilage psychrotrophic gram-negative bacteria identified by biochemical and molecular methods, Lactobacillus (six species) and Pseudomonas (six species) predominated. Lactococcus, Leuconostoc, Carnobacterium (C. piscicola and C. divergens), Aeromonas, and Photobacterium were the most common genera, and Lactococcus lactis, Lactobacillus plantarum, Pseudomonas fluorescens, and Aeromonas hydrophila were the most common species. These findings indicate that the microbiological quality of fresh fish in Tunisia can be preserved by controlling pathogenic and psychrotrophic bacteria.

Pathogenic bacteria and microbial-source tracking markers in Brandywine Creek Basin, Pennsylvania and Delaware, 2009-10

Science.gov (United States)

Duris, Joseph W.; Reif, Andrew G.; Olson, Leif E.; Johnson, Heather E.

2011-01-01

virulent type of pathogenic E. coli, was found only in the West Branch and main stem at high flow but was not found in the East Branch under similar conditions. However, it must be noted that throughout the entire year of sampling there were occasions, during both high and normal flows, when both the East and West Branches were potential contributors of pathogen and microbial-source tracking markers to the main stem. Therefore, this study indicates that under selected conditions (high flow, October through March), West Branch Brandywine Creek Basin was the most likely source of elevated FIB densities in the main stem. These elevated densities are associated with more frequent detection of selected pathogenic E. coli markers (rfbO157 stx1) and are associated with MST markers of bovine source. However, during other times of the year, both the West Branch and East Branch Basins are acting as potential sources of FIB and fecally derived pathogens.

Hard surface biocontrol in hospitals using microbial-based cleaning products.

Directory of Open Access Journals (Sweden)

Alberta Vandini

Full Text Available Healthcare-Associated Infections (HAIs are one of the most frequent complications occurring in healthcare facilities. Contaminated environmental surfaces provide an important potential source for transmission of many healthcare-associated pathogens, thus indicating the need for new and sustainable strategies.This study aims to evaluate the effect of a novel cleaning procedure based on the mechanism of biocontrol, on the presence and survival of several microorganisms responsible for HAIs (i.e. coliforms, Staphyloccus aureus, Clostridium difficile, and Candida albicans on hard surfaces in a hospital setting.The effect of microbial cleaning, containing spores of food grade Bacillus subtilis, Bacillus pumilus and Bacillus megaterium, in comparison with conventional cleaning protocols, was evaluated for 24 weeks in three independent hospitals (one in Belgium and two in Italy and approximately 20000 microbial surface samples were collected.Microbial cleaning, as part of the daily cleaning protocol, resulted in a reduction of HAI-related pathogens by 50 to 89%. This effect was achieved after 3-4 weeks and the reduction in the pathogen load was stable over time. Moreover, by using microbial or conventional cleaning alternatively, we found that this effect was directly related to the new procedure, as indicated by the raise in CFU/m2 when microbial cleaning was replaced by the conventional procedure. Although many questions remain regarding the actual mechanisms involved, this study demonstrates that microbial cleaning is a more effective and sustainable alternative to chemical cleaning and non-specific disinfection in healthcare facilities.This study indicates microbial cleaning as an effective strategy in continuously lowering the number of HAI-related microorganisms on surfaces. The first indications on the actual level of HAIs in the trial hospitals monitored on a continuous basis are very promising, and may pave the way for a novel and cost

Hard surface biocontrol in hospitals using microbial-based cleaning products.

Science.gov (United States)

Vandini, Alberta; Temmerman, Robin; Frabetti, Alessia; Caselli, Elisabetta; Antonioli, Paola; Balboni, Pier Giorgio; Platano, Daniela; Branchini, Alessio; Mazzacane, Sante

2014-01-01

Healthcare-Associated Infections (HAIs) are one of the most frequent complications occurring in healthcare facilities. Contaminated environmental surfaces provide an important potential source for transmission of many healthcare-associated pathogens, thus indicating the need for new and sustainable strategies. This study aims to evaluate the effect of a novel cleaning procedure based on the mechanism of biocontrol, on the presence and survival of several microorganisms responsible for HAIs (i.e. coliforms, Staphyloccus aureus, Clostridium difficile, and Candida albicans) on hard surfaces in a hospital setting. The effect of microbial cleaning, containing spores of food grade Bacillus subtilis, Bacillus pumilus and Bacillus megaterium, in comparison with conventional cleaning protocols, was evaluated for 24 weeks in three independent hospitals (one in Belgium and two in Italy) and approximately 20000 microbial surface samples were collected. Microbial cleaning, as part of the daily cleaning protocol, resulted in a reduction of HAI-related pathogens by 50 to 89%. This effect was achieved after 3-4 weeks and the reduction in the pathogen load was stable over time. Moreover, by using microbial or conventional cleaning alternatively, we found that this effect was directly related to the new procedure, as indicated by the raise in CFU/m2 when microbial cleaning was replaced by the conventional procedure. Although many questions remain regarding the actual mechanisms involved, this study demonstrates that microbial cleaning is a more effective and sustainable alternative to chemical cleaning and non-specific disinfection in healthcare facilities. This study indicates microbial cleaning as an effective strategy in continuously lowering the number of HAI-related microorganisms on surfaces. The first indications on the actual level of HAIs in the trial hospitals monitored on a continuous basis are very promising, and may pave the way for a novel and cost-effective strategy

Zinc bioaccumulation by microbial consortium isolated from nickel smelter sludge disposal site

Directory of Open Access Journals (Sweden)

Kvasnová Simona

2017-06-01

Full Text Available Heavy metal pollution is one of the most important environmental issues of today. Bioremediation by microorganisms is one of technologies extensively used for pollution treatment. In this study, we investigated the heavy metal resistance and zinc bioaccumulation by microbial consortium isolated from nickel sludge disposal site near Sereď (Slovakia. The composition of consortium was analyzed based on MALDI-TOF MS of cultivable bacteria and we have shown that the consortium was dominated by bacteria of genus Arthrobacter. While consortium showed very good growth in the zinc presence, it was able to remove only 15 % of zinc from liquid media. Selected members of consortia have shown lower growth rates in the zinc presence but selected isolates have shown much higher bioaccumulation abilities compared to whole consortium (up to 90 % of zinc removal for NH1 strain. Bioremediation is frequently accelerated through injection of native microbiota into a contaminated area. Based on data obtained in this study, we can conclude that careful selection of native microbiota could lead to the identification of bacteria with increased bioaccumulation abilities.

Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation.

Directory of Open Access Journals (Sweden)

Martin Meyer

2016-08-01

Full Text Available We here compared pathogenic (p and non-pathogenic (np isolates of Entamoeba histolytica to identify molecules involved in the ability of this parasite to induce amoebic liver abscess (ALA-like lesions in two rodent models for the disease. We performed a comprehensive analysis of 12 clones (A1-A12 derived from a non-pathogenic isolate HM-1:IMSS-A and 12 clones (B1-B12 derived from a pathogenic isolate HM-1:IMSS-B. "Non-pathogenicity" included the induction of small and quickly resolved lesions while "pathogenicity" comprised larger abscess development that overstayed day 7 post infection. All A-clones were designated as non-pathogenic, whereas 4 out of 12 B-clones lost their ability to induce ALAs in gerbils. No correlation between ALA formation and cysteine peptidase (CP activity, haemolytic activity, erythrophagocytosis, motility or cytopathic activity was found. To identify the molecular framework underlying different pathogenic phenotypes, three clones were selected for in-depth transcriptome analyses. Comparison of a non-pathogenic clone A1np with pathogenic clone B2p revealed 76 differentially expressed genes, whereas comparison of a non-pathogenic clone B8np with B2p revealed only 19 differentially expressed genes. Only six genes were found to be similarly regulated in the two non-pathogenic clones A1np and B8np in comparison with the pathogenic clone B2p. Based on these analyses, we chose 20 candidate genes and evaluated their roles in ALA formation using the respective gene-overexpressing transfectants. We conclude that different mechanisms lead to loss of pathogenicity. In total, we identified eight proteins, comprising a metallopeptidase, C2 domain proteins, alcohol dehydrogenases and hypothetical proteins, that affect the pathogenicity of E. histolytica.

Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation.

Science.gov (United States)

Meyer, Martin; Fehling, Helena; Matthiesen, Jenny; Lorenzen, Stephan; Schuldt, Kathrin; Bernin, Hannah; Zaruba, Mareen; Lender, Corinna; Ernst, Thomas; Ittrich, Harald; Roeder, Thomas; Tannich, Egbert; Lotter, Hannelore; Bruchhaus, Iris

2016-08-01

We here compared pathogenic (p) and non-pathogenic (np) isolates of Entamoeba histolytica to identify molecules involved in the ability of this parasite to induce amoebic liver abscess (ALA)-like lesions in two rodent models for the disease. We performed a comprehensive analysis of 12 clones (A1-A12) derived from a non-pathogenic isolate HM-1:IMSS-A and 12 clones (B1-B12) derived from a pathogenic isolate HM-1:IMSS-B. "Non-pathogenicity" included the induction of small and quickly resolved lesions while "pathogenicity" comprised larger abscess development that overstayed day 7 post infection. All A-clones were designated as non-pathogenic, whereas 4 out of 12 B-clones lost their ability to induce ALAs in gerbils. No correlation between ALA formation and cysteine peptidase (CP) activity, haemolytic activity, erythrophagocytosis, motility or cytopathic activity was found. To identify the molecular framework underlying different pathogenic phenotypes, three clones were selected for in-depth transcriptome analyses. Comparison of a non-pathogenic clone A1np with pathogenic clone B2p revealed 76 differentially expressed genes, whereas comparison of a non-pathogenic clone B8np with B2p revealed only 19 differentially expressed genes. Only six genes were found to be similarly regulated in the two non-pathogenic clones A1np and B8np in comparison with the pathogenic clone B2p. Based on these analyses, we chose 20 candidate genes and evaluated their roles in ALA formation using the respective gene-overexpressing transfectants. We conclude that different mechanisms lead to loss of pathogenicity. In total, we identified eight proteins, comprising a metallopeptidase, C2 domain proteins, alcohol dehydrogenases and hypothetical proteins, that affect the pathogenicity of E. histolytica.

Pathogenic characteristics of Candida albicans isolated from oral cavities of denture wearers and cancer patients wearing oral prostheses.

Science.gov (United States)

Mothibe, J V; Patel, M

2017-09-01

Candida albicans cause opportunistic infections including oral candidiasis in immunocompromised patients. It has an ability to cause infection due to its virulence factors. This study investigated the pathogenic characteristics of C. albicans isolated from the oral cavities of healthy subjects and two vulnerable groups, denture wearers and cancer patients wearing oral prostheses. Oral rinse samples were collected and cultured for the quantitative and qualitative analysis of Candida. Twenty strains of C. albicans isolated from the healthy individuals and denture wearers and, 14 strains isolated from the cancer patients were selected and their pathogenic characteristics were measured. The results of the study groups were compared using a Scheffe test for pairwise comparison and a chi square test. Denture wearer and cancer patients with prostheses carried significantly higher number (p production were significantly higher in the strains from denture wearers. In addition, high number of isolates from the denture wearers produced phospholipase and proteinase (85% and 80% respectively) compared to the strains from normal subjects (25% and 60% respectively). Only the germ tube formation and adherence ability were significantly higher in the strains from the cancer patients with prostheses (p = 0.05 and p oral cavity and prostheses is important in the prevention of colonization of Candida and the development of oral candidiasis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthetic microbial ecology and the dynamic interplay between microbial genotypes.

Science.gov (United States)

Dolinšek, Jan; Goldschmidt, Felix; Johnson, David R

2016-11-01

Assemblages of microbial genotypes growing together can display surprisingly complex and unexpected dynamics and result in community-level functions and behaviors that are not readily expected from analyzing each genotype in isolation. This complexity has, at least in part, inspired a discipline of synthetic microbial ecology. Synthetic microbial ecology focuses on designing, building and analyzing the dynamic behavior of ‘ecological circuits’ (i.e. a set of interacting microbial genotypes) and understanding how community-level properties emerge as a consequence of those interactions. In this review, we discuss typical objectives of synthetic microbial ecology and the main advantages and rationales of using synthetic microbial assemblages. We then summarize recent findings of current synthetic microbial ecology investigations. In particular, we focus on the causes and consequences of the interplay between different microbial genotypes and illustrate how simple interactions can create complex dynamics and promote unexpected community-level properties. We finally propose that distinguishing between active and passive interactions and accounting for the pervasiveness of competition can improve existing frameworks for designing and predicting the dynamics of microbial assemblages.

Establishment of a Pathogenicity Index for One-day-old Broilers to Pasteurella multocida Strains Isolated from Clinical Cases in Poultry and Swine

Directory of Open Access Journals (Sweden)

RM Pilatti

Full Text Available ABSTRACT Although Pasteurella multocida is a member of the respiratory microbiota, under some circumstances, it is a primary agent of diseases , such as fowl cholera (FC, that cause significant economic losses. Experimental inoculations can be employed to evaluate the pathogenicity of strains, but the results are usually subjective and knowledge on the pathogenesis of this agent is still limited. The objective of this study was to establish a new methodology for classifying the pathogenicity of P. multocida by formulating a standard index. Strains isolated from FC cases and from swine with respiratory problems were selected. One hundred mL of a bacterial culture of each strain, containing 106 CFU, was inoculated in 10 one-day-old broilers. Mortality after inoculation, time of death (TD, and the presence of six macroscopic lesions were evaluated over a period of seven days post-inoculation (dpi. A Pathogenicity Index Per Bird (IPI, ranging 0 to 10, was calculated. Liver and heart fragments were collected to reisolate the bacteria. Blood was collected from the surviving birds, and an ELISA test was carried out to detect specific antibodies. The median of the pathogenicity indices, the number of lesions and the rate of bacteria reisolation were significantly different (p<0.05 among the origins of the isolates (p<0.05. The pathogenicity index developed in this study allows the classification of Pasteurella multocida pathogenicity and may be an alternative to the pathogenicity models currently used for screening.

Enteric pathogen modification by anaecic earthworm, Lampito Mauritii

African Journals Online (AJOL)

The biosolids from municipal wastewater treatment plant contains several enteric microbial pathogens, predominantly Salmonella and Escherichia species in the range of 15-18 x 104 CFU/g and 11-12 x 104 CFU/g respectively. The present study investigates the influence of earthworm, Lampito mauritii on enteric pathogen ...

Microbial Source Tracking in a Watershed Dominated by Swine

Directory of Open Access Journals (Sweden)

Joice F. Lubbers

2010-09-01

Full Text Available The high concentration of swine production in southeastern North Carolina generates public health concerns regarding the potential transport of pathogens from these production systems to nearby surface waters. The microbial source tracking (MST tool, antibiotic resistance analysis (ARA, was used to identify sources of E. coli in a segment of Six Runs Creek in Sampson County, North Carolina. Among 52 water samples, fecal coliform (FC counts averaged 272.1 ± 181.6 CFU/100 mL. Comparisons of isolates from water samples to an ARA library with an average rate of correct classification (ARCC of 94.3% indicated an average of 64% and 27.1% of 1,961 isolates from Six Runs Creek were associated with lagoon effluent and cattle manure respectively. The potential for aerosol transport of bacteria during lagoon spray events, as well as, the potential for wildlife to serve as a vehicle of transport for bacteria from fields and lagoons to nearby surface waters should be investigated further.

Inhibitory effect of Lactobacillus rhamnosus on pathogenic bacteria isolated from women with bacterial vaginosis

Directory of Open Access Journals (Sweden)

Gita Eslami

2014-06-01

Full Text Available Background: Considering the high prevalence of bacterial vaginosis and its association with urinary tract infection in women and treatment of gynecologic problems occur when a high recurrence of bacterial vaginosis is often treated with antibiotics. The purpose of this study is to investigate the inhibitory effect of Lactobacillus rhamnosus on pathogenic bacteria isolated from women with bacterial vaginosis, respectively.Materials and Methods: 96 samples from women with bacterial vaginosis discharge referred to health centers dependent Shahid Beheshti University in 91-92 were taken by a gynecologist with a dacron swab and put in sterile tubes containing TSB broth and Thioglycollate broth and were immediately sent to the lab location in cold chain for the next stages of investigation. From Thioglycollate and TSB medium was cultured on blood agar and EMB and Palkam and Differential diagnosis environments, and then incubated for 24 h at 37°C. Strains of Lactobacillus rhamnosus were cultured in MRSA environment and were transfered to the lab. After purification of pathogenic bacteria, MIC methods and antibiogram, Lactobacillus rhamnosus inhibitory effect on pathogenic bacteria is checked. Statistical analysis was done by SPSS software v.16.Results: The results of this study show the inhibitory effect of Lactobacillus rhamnosus on some pathogenic bacteria that cause bacterial vaginosis, including Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Streptococcus agalactiae, Entrococcus, Listeria monocytogenes and E.Coli. Microscopic examination of stained smears of the large number of Lactobacillus and pathogenic bacteria showed reduced. The prevalence of abnormal vaginal discharge, history of drug use means of preventing pregnancy and douching, respectively, 61%, 55%, 42% and 13% respectively. Significant difference was observed between the use and non-use of IUD in women with bacterial vaginosis infection

[Highly pathogenic avian influenza--monitoring of migratory waterfowl].

Science.gov (United States)

Otsuki, Koichi; Ito, Toshihiro

2006-10-01

Since 1979, the group belonging to Departments of Veterinary Microbiology, Veterinary Public Health and the Avian Zoonoses Research Centre, Faculty of Agriculture, Tottori University is continuing isolation of avian influenza virus from such migratory waterfowls as whistling swan, pintail and tufted dugs flying from Siberia and/or northern China. They have already isolated many interesting influenza viruses. Serotype of the isolates is various; some H5 and H7 and human types of viruses were also isolated; and its pathogenicity for chickens is not high. It was interested that low pathogenic H5N3 virus isolated from whistling swan acquired severe pathogenicity during passage in chicks.

Occurrence of root parsley pathogens inhabiting seeds

Directory of Open Access Journals (Sweden)

Bogdan Nowicki

2013-12-01

Full Text Available The studies on root parsley pathogens inhabiting seeds were conducted during 1981-1988 and in 1993. Filter paper method with prefreezing and keeping under light was used. Each test sample comprised 500 seeds. Pathogenicity of collected fungal isolates was tested following two laboratory methods. 238 seed samples were studied. 18 fungal species were found but only 7 proved to be important pathogens of root parsley. The most common inhabitants of root parsley seeds were Alternaria spp. A.allernata occurred on 74,8% of seeds but only a few isolates showed to be slightly pathogenic while A.petroselini and A.radicina were higly pathogenic and inhabited 11,4 and 4,2% of seeds, respectively. The second group of important pathogens were species of Fusarium found on 3,9% of seeds. F.avenaceum dominated as it comprised 48% of Fusarium isolates, the next were as follow: F.culmorum - 20%, F.equiseti - 15%, F.solani - 8%, F.oxysporum - 7% and F.dimerum -2%. Some fungi like Botrytis cinerea, Septoria petroselini and Phoma spp. inhabited low number of seeds, respectively O,4; 0,5 and 0,8%, but they were highly pathogenic to root parsley. The fungi: Bipolaris sorokiniana, Drechslera biseptata, Stemphylium botryosum and Ulocludium consortiale showed slight pathogenicity. They were isolated from 3,8% of seeds.

Phosphorylation and proteome dynamics in pathogen-resistant tomato plants

NARCIS (Netherlands)

Stulemeijer, I.J.E.

2008-01-01

Microbial plant pathogens impose a continuous threat on global food production. Similar to disease resistance in mammals, an innate immune system allows plants to recognise pathogens and swiftly activate defence. For the work described in this thesis, the interaction between tomato and the

Variable virulence among isolates of Ascosphaera apis: testing the parasite-pathogen hypothesis for the evolution of polyandry in social insects

Science.gov (United States)

Lee, G. M.; McGee, P. A.; Oldroyd, B. P.

2013-03-01

The queens of many eusocial insect species are polyandrous. The evolution of polyandry from ancestral monoandry is intriguing because polyandry undermines the kin-selected benefits of high intracolonial relatedness that are understood to have been central to the evolution of eusociality. An accumulating body of evidence suggests that polyandry evolved from monoandry in part because genetically diverse colonies better resist infection by pathogens. However, a core assumption of the "parasite-pathogen hypothesis", that there is variation in virulence among strains of pathogens, remains largely untested in vivo. Here, we demonstrate variation in virulence among isolates of Ascosphaera apis, the causative organism of chalkbrood disease in its honey bee ( Apis mellifera) host. More importantly, we show a pathogen-host genotypic interaction for resistance and pathogenicity. Our findings therefore support the parasite-parasite hypothesis as a factor in the evolution of polyandry among eusocial insects.

Inhibitory Effect of Lactobacillus reuteri on Some Pathogenic Bacteria Isolated From Women With Bacterial Vaginosis

Directory of Open Access Journals (Sweden)

Eslami

2014-08-01

Full Text Available Background Considering the high prevalence of bacterial vaginosis and its association with urinary tract infection in women and treatment of gynecologic problems occur when a high recurrence of bacterial vaginosis is often treated with antibiotics. Objectives The purpose of this study was to investigate the inhibitory effect of Lactobacillus reuteri on pathogenic bacteria isolated from women with bacterial vaginosis. Materials and Methods Ninety-six samples were obtained from vaginal discharge of women with bacterial vaginosis by a gynecologist with a Dacron swab and put in sterile tubes containing TSB broth and Thioglycollate broth. Then were immediately sent to the laboratory in cold chain for further assessment. Afterward, culture was transferred on blood agar, EMB, Palcam and differential diagnosis environments. Then cultures were incubated for 24 hours at 37 °C. Lactobacillus reuteri strains were cultured in MRS environment and transferred to laboratory. After purification of pathogenic bacteria, Lactobacillus reuteri inhibitory effect on pathogenic bacteria was evaluated by minimum inhibitory concentration (MIC and antibiogram. Statistical analysis was performed using SPSS software v.16. Results The results of this study demonstrated the inhibitory effect of Lactobacillus reuteri on some pathogenic bacteria that cause bacterial, including Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Streptococcus agalactiae, Enterococcus, Listeria monocytogenes and E. coli. Microscopic examination of stained smears of most Lactobacillus and pathogenic bacteria showed reduced. The prevalence of abnormal vaginal discharge, history of drug use, contraceptive methods and douching were 61%, 55%, 42% and 13%, respectively. Significant difference was observed between the use and non-use of IUD in women with bacterial. Conclusions Our findings indicated the inhibitory effect of Lactobacillus reuteri on pathogenic bacteria that

Fungi of the genus Fusarium as pathogens of soybean seedlings

Directory of Open Access Journals (Sweden)

Joanna Marcinkowska

2013-12-01

Full Text Available Twenty isolates of fungi of the genus Fusarium collected in the period 1980-1982 from various organs of diseased soybean plants were investigated. Eight of them proved pathogenic to soybean seedlings. The species F. culmorum was most numerously represented among the isolated (4 of 8 pathogens. Isolates of F. sambucinum were also pathogenic (2 of 4 and those of F. soloni (1 of 3, too. The only isolate of F. avenaceum also caused seedling blight. Two isolates of F. oxysporum and two of F. arthrosporioides were not pathogenic. Numerous isolates affected seed gernination and one greatly inhibited growth of the infected seedlings. Pathogenicity was tested in the laboratory in Petri plates on isolate cultures and on filter paper imbibed with fungal inoculum and, in the greenhouse on a peat and perlite substrate. The degree of infection and the character of the disease symptoms depended on the experimental conditions. The results of experiments in plates and in the greenhouse supplemented one another.

Investigating the Antimicrobial Bioactivity of Cyano bacterial Extracts on Some Plant and Human Pathogens

International Nuclear Information System (INIS)

El-Semary, N.A.; Osman, M.E.; Ahmed, A.S.; Botros, H.W.; Farag, A.T.

2014-01-01

The search for broad spectrum antimicrobial agents against microbial pathogens, as the available bioactive compounds, has decreasing efficacy and the multidrug resistance trait is spreading among pathogens. Accordingly, the study was carried out to investigate the antimicrobial bioactivity of extracts derived from a cyano bacterial strain from Egypt. The solvents used were diethyl ether, chloroform and methanol. The antimicrobial bioassay of the lipophilic fraction dissolved in diethyl ether of Synechococcus spp. (isolated from Wadi El-Natroun, Egypt) showed the highest broad spectrum bioactivity as it inhibited the growth of both plant and human pathogens. The extract was also effective on the filamentous plant pathogenic fungi Aspergillus flavus and Aspergillus niger. The effects of incubation periods, growth media and pH values on both growth and antimicrobial activity of Synechococcus spp. were investigated. Chu medium was the medium that gave the highest growth followed by BG11 medium then Oscillatoria medium and all these three media showed antibacterial activities but only BG11 showed both antibacterial and antifungal activities after 18 days of incubation. The pH value 10 proved to be the best for growth and antimicrobial activities of Synechococcus spp. in BG11 medium

Arabidopsis thaliana: A model host plant to study plant-pathogen interaction using Chilean field isolates of Botrytis cinerea

Directory of Open Access Journals (Sweden)

JUAN GONZÁLEZ

2006-01-01

Full Text Available One of the fungal pathogens that causes more agriculture damage is Botrytis cinerea. Botrytis is a constant threat to crops because the fungus infects a wide range of host species, both native and cultivated. Furthermore, Botrytis persists on plant debris in and on the soil. Some of the most serious diseases caused by Botrytis include gray mold on vegetables and fruits, such as grapes and strawberries. Botrytis also causes secondary soft rot of fruits and vegetables during storage, transit and at the market. In many plant-pathogen interactions, resistance often is associated with the deposition of callose, accumulation of autofluorescent compounds, the synthesis and accumulation of salicylic acid as well as pathogenesis-related proteins. Arabidopsis thaliana has been used as a plant model to study plant-pathogen interaction. The genome of Arabidopsis has been completely sequenced and this plant serves as a good genetic and molecular model. In this study, we demonstrate that Chilean field isolates infect Arabidopsis thaliana and that Arabidopsis subsequently activates several defense response mechanisms associated with a hypersensitive response. Furthermore, we propose that Arabidopsis may be used as a model host species to analyze the diversity associated with infectivity among populations of Botrytis cinerea field isolates

The in vitro evaluation of tigecycline tested against pathogens isolated in eight countries in the Asia-Western Pacific region (2008).

Science.gov (United States)

Farrell, David J; Turnidge, John D; Bell, Jan; Sader, Helio S; Jones, Ronald N

2010-06-01

To determine the in vitro activity of tigecycline and comparator common use antimicrobial agents tested against contemporary bacterial pathogens from the Asia-Western Pacific region. As part of the SENTRY Antimicrobial Surveillance Program, a total of 5759 Gram-positive and Gram-negative isolates were collected from 28 medical centers in eight Asia-Western Pacific countries during 2008. Minimum inhibitory concentrations (MICs) were determined using Clinical and Laboratory Standards Institute (CLSI) broth microdilution method and interpreted using CLSI breakpoints. United States Food and Drug Administration (US-FDA) breakpoints were used to interpret tigecycline susceptibility. Antimicrobial resistance was found to be widespread and prevalence varied considerably between the eight countries. Against pathogens for which breakpoints were available, >98% of all isolates were susceptible to tigecycline. Against all Gram-positive isolates, including methicillin (oxacillin)-resistant Staphylococcus aureus, penicillin- and multidrug-resistant pneumococci, and vancomycin-resistant enterococci, the highest tigecycline MIC found was 1 microg/ml. Against all Enterobacteriaceae, including extended-spectrum beta-lactamase phenotypes, tigecycline susceptibility was 97.5%. Tigecycline had good activity against Acinetobacter spp. but was much less active against Pseudomonas aeruginosa. Tigecycline demonstrated excellent sustained in vitro activity against a wide spectrum of contemporary Gram-positive and -negative pathogens from Asia-Western Pacific countries. Copyright (c) 2010 The British Infection Society. Published by Elsevier Ltd. All rights reserved.

Celecoxib Enhances the Efficacy of Low-Dose Antibiotic Treatment against Polymicrobial Sepsis in Mice and Clinical Isolates of ESKAPE Pathogens.

Science.gov (United States)

Annamanedi, Madhavi; Varma, Gajapati Y N; Anuradha, K; Kalle, Arunasree M

2017-01-01

Treatment of multidrug resistant bacterial infections has been a great challenge globally. Previous studies including our study have highlighted the use of celecoxib, a non-steroidal anti-inflammatory drug in combination with antibiotic has decreased the minimal inhibitory concentration to limit Staphylococcus aureus infection. However, the efficacy of this combinatorial treatment against various pathogenic bacteria is not determined. Therefore, we have evaluated the potential use of celecoxib in combination with low doses of antibiotic in limiting Gram-positive and Gram-negative bacteria in vivo in murine polymicrobial sepsis developed by cecum ligation and puncture (CLP) method and against clinically isolated human ESKAPE pathogens ( Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa , and Enterobacter species). The in vivo results clearly demonstrated a significant reduction in the bacterial load in different organs and in the inflammatory markers such as COX-2 and NF-κB via activation of SIRT1 in mice treated with imipenem, a choice of antibiotic for polymicrobial sepsis treatment. Combinatorial treatment of ampicillin and celecoxib was effective on clinical isolates of ESKAPE pathogens, 45% of tested clinical isolates showed more than 50% reduction in the colony forming units when compared to ampicillin alone. In conclusion, this non-traditional treatment strategy might be effective in clinic to reduce the dose of antibiotic to treat drug-resistant bacterial infections.

Phosphorylation and proteome dynamics in pathogen-resistant tomato plants

OpenAIRE

Stulemeijer, I.J.E.

2008-01-01

Microbial plant pathogens impose a continuous threat on global food production. Similar to disease resistance in mammals, an innate immune system allows plants to recognise pathogens and swiftly activate defence. For the work described in this thesis, the interaction between tomato and the extracellular fungal pathogen Cladosporium fulvum serves as a model system to study host resistance and susceptibility in plant-pathogen interactions. Resistance to C. fulvum in tomato plants follows the ge...

Pathogen recognition in the innate immune response.

Science.gov (United States)

Kumar, Himanshu; Kawai, Taro; Akira, Shizuo

2009-04-28

Immunity against microbial pathogens primarily depends on the recognition of pathogen components by innate receptors expressed on immune and non-immune cells. Innate receptors are evolutionarily conserved germ-line-encoded proteins and include TLRs (Toll-like receptors), RLRs [RIG-I (retinoic acid-inducible gene-I)-like receptors] and NLRs (Nod-like receptors). These receptors recognize pathogens or pathogen-derived products in different cellular compartments, such as the plasma membrane, the endosomes or the cytoplasm, and induce the expression of cytokines, chemokines and co-stimulatory molecules to eliminate pathogens and instruct pathogen-specific adaptive immune responses. In the present review, we will discuss the recent progress in the study of pathogen recognition by TLRs, RLRs and NLRs and their signalling pathways.

IPM potentials of microbial pathogens and diseases of mites

NARCIS (Netherlands)

van der Geest, L.P.S.; Ciancio, A.; Mukerji, K.G.

2010-01-01

An overview is given of diseases in mites, caused by infectious microorganisms. Many pathogens play an important role in the regulation of natural populations of mite populations and are for this reason subject of research on the feasibility to develop such pathogens to biological control agents.

Rhizospheric microbial communities are driven by Panax ginseng at different growth stages and biocontrol bacteria alleviates replanting mortality

Directory of Open Access Journals (Sweden)

Linlin Dong

2018-03-01

Full Text Available The cultivation of Panax plants is hindered by replanting problems, which may be caused by plant-driven changes in the soil microbial community. Inoculation with microbial antagonists may efficiently alleviate replanting issues. Through high-throughput sequencing, this study revealed that bacterial diversity decreased, whereas fungal diversity increased, in the rhizosphere soils of adult ginseng plants at the root growth stage under different ages. Few microbial community, such as Luteolibacter, Cytophagaceae, Luteibacter, Sphingomonas, Sphingomonadaceae, and Zygomycota, were observed; the relative abundance of microorganisms, namely, Brevundimonas, Enterobacteriaceae, Pandoraea, Cantharellales, Dendryphion, Fusarium, and Chytridiomycota, increased in the soils of adult ginseng plants compared with those in the soils of 2-year-old seedlings. Bacillus subtilis 50-1, a microbial antagonist against the pathogenic Fusarium oxysporum, was isolated through a dual culture technique. These bacteria acted with a biocontrol efficacy of 67.8%. The ginseng death rate and Fusarium abundance decreased by 63.3% and 46.1%, respectively, after inoculation with B. subtilis 50-1. Data revealed that microecological degradation could result from ginseng-driven changes in rhizospheric microbial communities; these changes are associated with the different ages and developmental stages of ginseng plants. Biocontrol using microbial antagonists alleviated the replanting problem. KEY WORDS: Panax ginseng, Microbial communities, Replanting problem, High-throughput sequencing, Different ages, Bioremediation

A novel photo-biological engineering method for Salvia miltiorrhiza-mediated fabrication of silver nanoparticles using LED lights sources and its effectiveness against Aedes aegypti mosquito larvae and microbial pathogens

Science.gov (United States)

In this study, Salvia miltiorrhiza-synthesized Ag nanoparticles (AgNPs) fabricated using sunlight or various LED lights were studied for their biophysical features and evaluated as larvicides against Aedes aegypti mosquitoes and growth inhibitors on different species of microbial pathogens. AgNPs pr...

The pathogenicity of avian metapneumovirus subtype C wild bird isolates in domestic turkeys

Directory of Open Access Journals (Sweden)

Cha Ra Mi

2013-01-01

Full Text Available Abstract Background Avian metapneumovirus subtype C (aMPV/C causes severe upper respiratory disease in turkeys. Previous report revealed the presence of aMPV/C in wild birds in the southeast regions of the U.S. Methods In this study, aMPV/C positive oral swabs from American coots (AC and Canada geese (CG were passaged three times in the respiratory tract of specific pathogen free (SPF turkeys and used as aMPV/C P3 virus isolates in subsequent studies. Results Wild bird P3 isolates showed similar growth characteristics when compared to virulent aMPV/C in chicken embryo fibroblast ( CEF cell cultures and their glycoprotein G gene sequence was closely related to the G gene of aMPV/C Colorado reference virus. Three-day-old commercial or SPF turkeys were inoculated oculonasally with wild bird aMPV/C P3 isolates. At 5 and 7 days post-inoculation (DPI, severe clinical signs were observed in both of the AC and CG virus-exposed groups. Viral RNA was detected in tracheal swabs by reverse transcriptase polymerase chain reaction (RT-PCR. In addition, immunohistochemistry showed virus replication in the nasal turbinate and trachea. All virus-exposed turkeys developed positive antibody response by 14 DPI. Conclusions Our data demonstrate that aMPV/C wild bird isolates induced typical aMPV/C disease in the domestic turkeys.

Incidence of bovine clinical mastitis in Jammu region and antibiogram of isolated pathogens

Directory of Open Access Journals (Sweden)

Adil Majid Bhat

2017-08-01

Full Text Available Aim: This study was conducted to evaluate the incidence of clinical mastitis in bovines of Jammu region, to identify the infectious organisms responsible for it, and the antimicrobial sensitivity of isolated pathogens. Materials and Methods: The study was conducted on cases that were presented to the Medicine Division of Teaching Veterinary Clinical Complex, Faculty of Veterinary Sciences and Animal Husbandry, R.S. Pura, Jammu, Jammu and Kashmir. A total of 260 cases of bovines were presented from June 30, 2012, to July 01, 2013, out of which 30 cases were of clinical mastitis. The diagnosis of clinical mastitis was made on the basis of history and clinical examination of affected animals. Results: Animal and quarter-wise incidence of clinical mastitis were found to be 11.5% and 5.76%, respectively. Of the 23 isolates obtained, Staphylococcus aureus (60.87% was the most frequently isolated organism, followed by coagulase negative Staphylococci (13.04%, Streptococcus uberis (4.35%, Streptococcus dysgalactiae (8.69%, and Escherichia coli (13.04%. The antimicrobial sensitivity of isolates revealed maximum sensitivity to enrofloxacin, gentamicin, amoxicillin/ sulbactam, ceftriaxone/tazobactam, ceftizoxime, ampicillin/sulbactam and least sensitivity for oxytetracycline and penicillin. Conclusion: Staphylococcus spp. is the major causative agent of clinical mastitis in bovines of Jammu region. The causative agents of the clinical mastitis were most sensitive to enrofloxacin and gentamicin.

The pathogenicity of avian metapneumovirus subtype C wild bird isolates in domestic turkeys.

Science.gov (United States)

Cha, Ra Mi; Yu, Qingzhong; Zsak, Laszlo

2013-01-30

Avian metapneumovirus subtype C (aMPV/C) causes severe upper respiratory disease in turkeys. Previous report revealed the presence of aMPV/C in wild birds in the southeast regions of the U.S. In this study, aMPV/C positive oral swabs from American coots (AC) and Canada geese (CG) were passaged three times in the respiratory tract of specific pathogen free (SPF) turkeys and used as aMPV/C P3 virus isolates in subsequent studies. Wild bird P3 isolates showed similar growth characteristics when compared to virulent aMPV/C in chicken embryo fibroblast ( CEF) cell cultures and their glycoprotein G gene sequence was closely related to the G gene of aMPV/C Colorado reference virus. Three-day-old commercial or SPF turkeys were inoculated oculonasally with wild bird aMPV/C P3 isolates. At 5 and 7 days post-inoculation (DPI), severe clinical signs were observed in both of the AC and CG virus-exposed groups. Viral RNA was detected in tracheal swabs by reverse transcriptase polymerase chain reaction (RT-PCR). In addition, immunohistochemistry showed virus replication in the nasal turbinate and trachea. All virus-exposed turkeys developed positive antibody response by 14 DPI. Our data demonstrate that aMPV/C wild bird isolates induced typical aMPV/C disease in the domestic turkeys.

High Throughput Sequencing for Detection of Foodborne Pathogens

Directory of Open Access Journals (Sweden)

Camilla Sekse

2017-10-01

Full Text Available High-throughput sequencing (HTS is becoming the state-of-the-art technology for typing of microbial isolates, especially in clinical samples. Yet, its application is still in its infancy for monitoring and outbreak investigations of foods. Here we review the published literature, covering not only bacterial but also viral and Eukaryote food pathogens, to assess the status and potential of HTS implementation to inform stakeholders, improve food safety and reduce outbreak impacts. The developments in sequencing technology and bioinformatics have outpaced the capacity to analyze and interpret the sequence data. The influence of sample processing, nucleic acid extraction and purification, harmonized protocols for generation and interpretation of data, and properly annotated and curated reference databases including non-pathogenic “natural” strains are other major obstacles to the realization of the full potential of HTS in analytical food surveillance, epidemiological and outbreak investigations, and in complementing preventive approaches for the control and management of foodborne pathogens. Despite significant obstacles, the achieved progress in capacity and broadening of the application range over the last decade is impressive and unprecedented, as illustrated with the chosen examples from the literature. Large consortia, often with broad international participation, are making coordinated efforts to cope with many of the mentioned obstacles. Further rapid progress can therefore be prospected for the next decade.

Bacteria-instructed synthesis of polymers for self-selective microbial binding and labelling

Science.gov (United States)

Magennis, E. Peter; Fernandez-Trillo, Francisco; Sui, Cheng; Spain, Sebastian G.; Bradshaw, David; Churchley, David; Mantovani, Giuseppe; Winzer, Klaus; Alexander, Cameron

2014-01-01

The detection and inactivation of pathogenic strains of bacteria continues to be an important therapeutic goal. Hence, there is a need for materials that can bind selectively to specific microorganisms, for diagnostic or anti-infective applications, but which can be formed from simple and inexpensive building blocks. Here, we exploit bacterial redox systems to induce a copper-mediated radical polymerisation of synthetic monomers at cell surfaces, generating polymers in situ that bind strongly to the microorganisms which produced them. This ‘bacteria-instructed synthesis’ can be carried out with a variety of microbial strains, and we show that the polymers produced are self-selective binding agents for the ‘instructing’ cell types. We further expand on the bacterial redox chemistries to ‘click’ fluorescent reporters onto polymers directly at the surfaces of a range of clinical isolate strains, allowing rapid, facile and simultaneous binding and visualisation of pathogens. PMID:24813421

Bacteria-instructed synthesis of polymers for self-selective microbial binding and labelling

Science.gov (United States)

Magennis, E. Peter; Fernandez-Trillo, Francisco; Sui, Cheng; Spain, Sebastian G.; Bradshaw, David J.; Churchley, David; Mantovani, Giuseppe; Winzer, Klaus; Alexander, Cameron

2014-07-01

The detection and inactivation of pathogenic strains of bacteria continues to be an important therapeutic goal. Hence, there is a need for materials that can bind selectively to specific microorganisms for diagnostic or anti-infective applications, but that can be formed from simple and inexpensive building blocks. Here, we exploit bacterial redox systems to induce a copper-mediated radical polymerization of synthetic monomers at cell surfaces, generating polymers in situ that bind strongly to the microorganisms that produced them. This ‘bacteria-instructed synthesis’ can be carried out with a variety of microbial strains, and we show that the polymers produced are self-selective binding agents for the ‘instructing’ cell types. We further expand on the bacterial redox chemistries to ‘click’ fluorescent reporters onto polymers directly at the surfaces of a range of clinical isolate strains, allowing rapid, facile and simultaneous binding and visualization of pathogens.

Isolation and Characterization of Methyl Parathion-degrading Bacteria Based on Microbial Sensor Construction

Directory of Open Access Journals (Sweden)

GENG Fang-fang

2014-12-01

Full Text Available Methyl parathion (MP, a kind of typical organophosphates pesticides (OPs, is widely used as agricultural insecticides. However, due to their neurotoxic effects on humans, the elimination of OPs has become increasingly important. Microbial sensors are consisted of biological components and transducers. Owing to their attractive advantages including low cost, easy of miniaturization and excellent selectivity, they have been widely used for environmental analysis. In this paper, four novel bacterial strains capable of utilizing methyl parathion as the sole carbon source were isolated from pesticide contaminated soils. These four isolates were identified based on morphological characteristics and 16S rRNA gene sequences analysis, and their capability of degrading methyl parathion were investigated by high performance liquid chromatography. The highest degrading efficiency strain was selected for further study of degrading mechanism. The results indicated that degradation rate of these four strains were all over 78% after incubation at 30 ℃, pH 7.0 for 7 d with the original concentration of methyl parathion 50 mg·L-1. The highest degradation rate was up to 100%. 16S rRNA gene sequences indicated that strain MP-6 was affiliated into the genus klebsiella. The LC-MS results indicated that methyl parathion was hydrolyzed to dimethyl thiophosphoric acid and p-nitrophenol by MP-6. A little of p-nitrophenol molecules could be further metabolized to 4-nitrocatechol and 1, 2, 4-benzenetrio. The results indicated that based on detecting the potential signal of intermediate product p-nitrophenol, the strain MP-6 could be used to construct microbial sensors for determination of organophosphorus pesticides in environment.

Current Microbial Isolates from Wound Swab and Their Susceptibility Pattern in a Private Medical College Hospital in Dhaka city

Directory of Open Access Journals (Sweden)

Shahin Sultana

2015-03-01

Full Text Available Background: Wound infection is one of the major health problems that are caused and aggravated by the invasion of pathogenic organisms where empiric treatment is routine. Objective: To isolate and identify the bacteria causing wound infection and to determine the antimicrobial susceptibility pattern. Materials and method: A total of 263 wound swab and pus samples were collected during the period of January to December 2012 from Delta Medical College and Hospital, Dhaka, Bangladesh. Swabs from the wound were inoculated on appropriate media and cultured and the isolates were identified by standard procedures as needed. Antimicrobial susceptibility testing was performed by disk diffusion method according to ‘The Clinical Laboratory Standard Institute’ guidelines. Results: In this study 220 bacterial isolates were recovered from 263 samples showing an isolation rate of 83.65%. The predominant bacteria isolated from infected wounds were Staphylococcus aureus 89 (40.45% followed by Escherichia coli 62 (28.18%, Pseudomonas aeruginosa 34 (15.45%, Enterococci 18 (8.18%, Acinetobacter 5 (2.27%, Klebsiella 9 (4.09% and Proteus 3 (3.36%. Staphylococcus aureus was sensitive to linezolid (94.38%, fusidic acid (91.01%, vancomycin (87.64%, amikacin (74.15% and gentamicin (73.03%. Among the Gram negative isolates Escherichia coli was predominant and showed sensitivity to imipenem (93.54% amikacin (83.87% colistin (53.22% and piperacillin and tazobactum (53.22% and pseudomonas showed sensitivity to amikacin (73.52%, imipenem (70.58% and colistin (70.58%. Conclusion: Staphylococcus aureus was the most frequently isolated pathogen from wound swab and the antibiotic sensitivity pattern of various isolates help to assist the clinician in appropriate selection of empirical antibiotics against wound infection.

Whey protein isolate/cellulose nanofibre/TiO2 nanoparticle/rosemary essential oil nanocomposite film: Its effect on microbial and sensory quality of lamb meat and growth of common foodborne pathogenic bacteria during refrigeration.

Science.gov (United States)

Alizadeh Sani, Mahmood; Ehsani, Ali; Hashemi, Mohammad

2017-06-19

The use of biodegradable nanocomposite films in active packaging is of great importance since they can have a controlled release of antimicrobial compounds. This study was conducted to evaluate the efficacy of whey protein isolate (WPI)/cellulose nanofibre (CNF) nanocomposite films containing 1.0% (w/w) titanium dioxide (TiO 2 ) and 2.0% (w/v) rosemary essential oil (REO) in preserving the microbial and sensory quality of lamb meat during the storage at 4±1°C. Initially, the best concentration of each compound to be added to the film was determined by micro-dilution and disc diffusion methods. The microbial and sensory properties of lamb meat were controlled in two groups (control and treatment) over 15days of storage. Then, the samples were analysed for total viable count (TVC), Pseudomonas spp. count, Enterobacteriaceae count, Lactic acid bacteria (LAB) count, inoculated Staphylococcus aureus count, Listeria monocytogenes count, and Escherichia coli O 157 :H 7 count. Microbial analysis and nine-point hedonic scale was applied for the sensory analysis. Results indicated that the use of nanocomposite films significantly reduced the bacterial counts of treatment group. Higher inhibition effect was observed on Gram-positive bacteria than on Gram-negative bacteria (Psensory evaluations also showed that the use of nanocomposite films significantly increased the shelf life of treated meat (15days) compared to the control meat (6days). Based on the results of this study, the edible nanocomposite films were effective in preserving the microbial and sensory qualities of lamb meat; therefore, this application is recommended in meat especially red meat. Copyright © 2017 Elsevier B.V. All rights reserved.

Short communication: Molecular characteristics, antimicrobial susceptibility, and pathogenicity of clinical Nocardia cyriacigeorgica isolates from an outbreak of bovine mastitis.

Science.gov (United States)

Chen, Wei; Liu, Yongxia; Barkema, Herman W; Gao, Jian; De Buck, Jeroen; Kastelic, John P; Liu, Gang; Ali, Tariq; Shahid, Muhammad; Han, Bo

2017-10-01

The occurrence of nocardial mastitis, mostly in the context of outbreaks, has been reported in many countries. However, there is a paucity of reports regarding detailed characterization of Nocardia cyriacigeorgica from bovine mastitis. Thus, herein we report characteristics, antimicrobial susceptibility patterns, molecular identification, and pathogenicity of N. cyriacigeorgica isolated from an outbreak of clinical mastitis in a dairy herd in northern China. A total of 182 (80.2%) lactating cows had clinical mastitis with severe inflammation and firmness of the udder, reduced milk production, and anorexia, with no apparent clinical response to common antibiotics. Out of 22 mastitic milk samples submitted to our laboratory, 12 N. cyriacigeorgica were isolated and characterized using standard microbiological analysis, 16S rRNA gene sequencing, random amplified polymorphic DNA PCR analysis, biochemical assays, and antibiotic susceptibility testing. Additionally, in vivo experiments were done to determine pathogenicity of these clinical mastitis isolates. All isolates were resistant to ampicillin, amoxicillin-clavulanic acid, ciprofloxacin, minocycline, rifampicin, and aminoglycosides (type VI pattern). Additionally, intramammary inoculation of mice with N. cyriacigeorgica caused chronic inflammatory changes, including hyperemia, edema, and infiltration of lymphocytes and neutrophils, as well as hyperplasia of lymph nodules in mammary glands. Therefore, we concluded that N. cyriacigeorgica was involved in the current outbreak of mastitis. To our best knowledge, this is the first report to characterize N. cyriacigeorgica isolated from cases of bovine mastitis in China. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Microbial contaminants in Pakistan: a review

Directory of Open Access Journals (Sweden)

Maida Kanwal

2016-04-01

Full Text Available Worldwide contamination of surface waters with microbial pathogens is of substantial health concern. These contaminants are usually transmitted by improper sanitation measures, unsafe waste disposal, excretions from patients, and physical contacts, i.e., sexual and nonsexual. Majority of these microbial pathogens have been categorized into three classes, i.e., bacteria, viruses and protozoa. Pakistan, being a developing country, is facing a noteworthy threat due to microbial contamination. In Pakistan, bacterial contaminants are reported extensively followed by viral and protozoa contaminants. The health issues associated with bacterial population includes dysentery, abdominal pain, headache, diarrhea etc.; and usually includes faecal and total coliforms, E. coli, Salmonella, Shigella and Campylobacter. The cases related to viral contamination are lesser but chronic and evidenced the presence of HCV, HAV, HEV viruses causing hepatitis, and other hepatic disorders. Lastly, the health impacts associated with protozoans are least reported; and a number of diseases such as giardia, cryptosporidium and toxoplasma have been linked with this class of contaminants. The current review compiles information of these biological contaminants along with their health issues in Pakistan. Moreover, potential sources and fate of microbial contaminants are also discussed.

Phenotypic and genotypic anti-microbial resistance profiles of campylobacters from untreated feedlot cattle and their environment.

Science.gov (United States)

Minihan, D; Whyte, P; O'mahony, M; Cowley, D; O'halloran, F; Corcoran, D; Fanning, S; Collins, J D

2006-05-01

Anti-microbial resistance is an emerging public health issue. Farmed animals may act as reservoirs and potential sources of anti-microbial resistant Campylobacters. The aim of this study was to investigate the anti-microbial resistance profile of cattle and environmental Campylobacter isolates from normal untreated feedlot cattle, the role of the gyrA Thr-86-Ile mutation in ciprofloxacin-resistant Campylobacter jejuni isolates and the involvement of the tripartite CmeABC efflux system for multi-resistant C. jejuni isolates. The phenotypic anti-microbial resistance testing was carried out on 500 Campylobacter isolates (445 cattle isolates and 55 environmental isolates). In general, there was a higher level of anti-microbial resistance for the environmental isolates compared with the animal isolates, 45% of the animal isolates were resistant to one or more of the seven anti-microbials compared with 84% of the environmental isolates. The combined cattle and environmental Campylobacters had 34 (6.8%) isolates resistant to three or more of the seven anti-microbials tested on all isolates and 11 (2.2%) isolates were resistant to the seven anti-microbials. There was a substantial level of ciprofloxacin-resistant Campylobacters in both animal (8.5%) and environmental (21.8%) isolates. The gyrA Thr-86-Ile mutation was only present in five of 22 ciprofloxacin-resistant C. jejuni isolates investigated. No multi-drug-resistant associated mutation was detected in the CmeB or the CmeR regions investigated. In conclusion, our study observed a substantial level of Campylobacter anti-microbial resistance, highlighting the need for an active anti-microbial surveillance program for food animals in Ireland and the importance of the chosen sampling point can have on the findings of such a program.

Frequency Of Isolation Of Salmonella From Commercial Poultry Feeds And Their Anti-Microbial Resistance Profiles, Imo State, Nigeria

Directory of Open Access Journals (Sweden)

Okoli IC

2006-09-01

Full Text Available This study was conducted to determine the frequency of isolation of salmonella and their microbial resistance profiles across different commercial poultry feeds sold in Imo State, Nigeria. Thirty-six bulk feed samples were colleted from 154 bag across different feed types and brands which included Guinea (GF, Top (TF, Vital (VF, Extra (EF, Animal care (AF and livestock (LF feeds. The salmonella isolated were tested against 14 anti-microbial drugs using the disc diffusion method. Bacterial load enumeration of the samples indicated a range of <30 colony forming unit (CFU to overgrowth at 104 serial dilutions. Eight feed samples (22.2% which cuts across the entire feed brands expect EF were positive for salmonella. The highest prevalence of 28.8% and 25.0% were recorded for LF and TF respectively, while VF, GF and AF had 11.1 and 10.0% respectively. Salmonella isolates showed high rates of resistance (51-100% against nitrofurantoin, ampicillin, tetracycline and ceftriazole, while moderate rates (31-50% were recorded for chloramphenicol, oxfloxacin and cotrimoxazole. Low resistance rates (1-30% were on the other hand recorded against ciprofloxacin and amoxycillin clavulanate (Augumentine, whereas zero resistance was demonstrated against pefloxacin, gentamycin, streptomycin and nalidixic. Commercial feeds form important channels for the dissemination of multi-drug resistant salmonella in Imo State, Nigeria.

Bio-prospecting of soil Streptomyces and its bioassay-guided isolation of microbial derived auxin with antifungal properties.

Science.gov (United States)

Saravana Kumar, P; Yuvaraj, P; Gabrial Paulraj, M; Ignacimuthu, S; Abdullah Al-Dhabi, N

2018-06-05

The present study was aimed to isolate bioactive actinomycetes with antifungal properties. Twenty-seven distinct soil derived actinomycetes were investigated for their antifungal activities. Among these, one isolate exhibited significant antifungal activity. Phenotypic and 16s rRNA gene sequence analysis strongly suggested that the active isolate BG4 belonged to the genus Streptomyces. Further, the chemical investigation of the active extract resulted in the isolation of a major compound and it was structurally elucidated as phenyl acetic acid (PAA). PAA exhibited promising antifungal activity with 100% inhibition, ranging from 31.25 to 25μg/mL. It is to be noted that PAA is naturally occurring and biologically active auxin. In addition, it has also been hypothesized that phytohormone endorsing the source of soil-symbionts has similar pathways for synthesizing compounds and its congeners of host due to horizontal gene transfer. These findings demonstrate that microbially derived phytohormone can be used to treat fungal infections. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Soil Microbial Functional and Fungal Diversity as Influenced by Municipal Sewage Sludge Accumulation

Directory of Open Access Journals (Sweden)

Magdalena Frąc

2014-08-01

Full Text Available Safe disposal of municipal sewage sludge is a challenging global environmental concern. The aim of this study was to assess the response of soil microbial functional diversity to the accumulation of municipal sewage sludge during landfill storage. Soil samples of a municipal sewage sludge (SS and from a sewage sludge landfill that was 3 m from a SS landfill (SS3 were analyzed relative to an undisturbed reference soil. Biolog EcoPlatesTM were inoculated with a soil suspension, and the Average Well Color Development (AWCD, Richness (R and Shannon-Weaver index (H were calculated to interpret the results. The fungi isolated from the sewage sludge were identified using comparative rDNA sequencing of the LSU D2 region. The MicroSEQ® ID software was used to assess the raw sequence files, perform sequence matching to the MicroSEQ® ID-validated reference database and create Neighbor-Joining trees. Moreover, the genera of fungi isolated from the soil were identified using microscopic methods. Municipal sewage sludge can serve as a habitat for plant pathogens and as a source of pathogen strains for biotechnological applications.

Soil Microbial Functional and Fungal Diversity as Influenced by Municipal Sewage Sludge Accumulation

Science.gov (United States)

Frąc, Magdalena; Oszust, Karolina; Lipiec, Jerzy; Jezierska-Tys, Stefania; Nwaichi, Eucharia Oluchi

2014-01-01

Safe disposal of municipal sewage sludge is a challenging global environmental concern. The aim of this study was to assess the response of soil microbial functional diversity to the accumulation of municipal sewage sludge during landfill storage. Soil samples of a municipal sewage sludge (SS) and from a sewage sludge landfill that was 3 m from a SS landfill (SS3) were analyzed relative to an undisturbed reference soil. Biolog EcoPlatesTM were inoculated with a soil suspension, and the Average Well Color Development (AWCD), Richness (R) and Shannon-Weaver index (H) were calculated to interpret the results. The fungi isolated from the sewage sludge were identified using comparative rDNA sequencing of the LSU D2 region. The MicroSEQ® ID software was used to assess the raw sequence files, perform sequence matching to the MicroSEQ® ID-validated reference database and create Neighbor-Joining trees. Moreover, the genera of fungi isolated from the soil were identified using microscopic methods. Municipal sewage sludge can serve as a habitat for plant pathogens and as a source of pathogen strains for biotechnological applications. PMID:25170681

Microbial dynamics during production of lesser mealworms (Alphitobius diaperinus) for human consumption at industrial scale.

Science.gov (United States)

Wynants, E; Crauwels, S; Verreth, C; Gianotten, N; Lievens, B; Claes, J; Van Campenhout, L

2018-04-01

In this study, the microbial dynamics during an industrial production cyle of lesser mealworms (Alphitobius diaperinus), sold for human consumption, were characterised. The microbial numbers as well as the microbial diversity were generally higher for the substrate, existing of remaining feed, faeces and exuviae, than for the larvae. Most of the species-level operational taxonomic units, identified using Illumina MiSeq sequencing, that were present in the feed were also detected in the larvae and vice versa. However, bacterial diversity decreased in the larvae during rearing. These results suggested that the feed is an important determinant of the insect bacterial community, but that some bacterial species show a competitive advantage inside the insect gut and become dominant. A blanching treatment of the larvae after harvest reduced most microbial counts, but the number of aerobic endospores remained at 4.0 log cfu/g. Whereas food pathogens Salmonella spp., Listeria monocytogenes, Bacillus cereus or coagulase-positive staphylococci were not detected in our study, fungal isolates corresponding to the genera Aspergillus and Fusarium were recovered. Therefore, it cannot be excluded that mycotoxins were present. The results of this study contribute to a better understanding of the microbial dynamics and food safety aspects during the production of edible insects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prevention of pathogenic Escherichia coli infection in mice and stimulation of macrophage activation in rats by an oral administration of probiotic Lactobacillus casei I-5.

Science.gov (United States)

Ishida-Fujii, Keiko; Sato, Rieko; Goto, Shingo; Yang, Xiao-Ping; Kuboki, Hiroshi; Hirano, Shin-Ichi; Sato, Michikatsu

2007-04-01

Lactobacillus casei I-5 isolated from an alcohol fermentation broth enhanced immunity and prevented pathogenic infection as a probiotic. Mice fed with I-5 cells for 11 days prior to an intraperitoneal challenge with pathogenic Escherichia coli Juhl exhibited a high survival rate compared with the control group. Rats fed with I-5 cells for 10 days significantly increased the phagocytosis of peritoneal macrophages. In a cell culture system employing peritoneal macrophages from rats, the I-5 administration activated NF-kappaB stimulated by LPS. It also enhanced LPS-stimulated IL-12 and TNF-alpha production, but not IL-6 production. These results show that L. casei I-5 effectively prevented infection by pathogenic E. coli possibly through the activation of peritoneal macrophages. The strain would be useful to prevent pathogenic microbial infections in humans and farm animals.

Selection and identification of non-pathogenic bacteria isolated from fermented pickles with antagonistic properties against two shrimp pathogens.

Science.gov (United States)

Zokaeifar, Hadi; Balcázar, José Luis; Kamarudin, Mohd Salleh; Sijam, Kamaruzaman; Arshad, Aziz; Saad, Che Roos

2012-06-01

In this study, potential probiotic strains were isolated from fermented pickles based on antagonistic activity against two shrimp pathogens (Vibrio harveyi and Vibrio parahaemolyticus). Two strains L10 and G1 were identified by biochemical tests, followed by16S ribosomal RNA gene sequence analysis as Bacillus subtilis, and characterized by PCR amplification of repetitive bacterial DNA elements (Rep-PCR). Subsequently, B. subtilis L10 and G1 strains were tested for antibacterial activity under different physical conditions, including culture medium, salinity, pH and temperature using the agar well diffusion assay. Among the different culture media, LB broth was the most suitable medium for antibacterial production. Both strains showed the highest level of antibacterial activity against two pathogens at 30 °C and 1.0% NaCl. Under the pH conditions, strain G1 showed the greatest activity against V. harveyi at pH 7.3-8.0 and against V. parahaemolyticus at pH 6.0-8.0, whereas strain L10 showed the greatest activity against two pathogens at pH 7.3. The cell-free supernatants of both strains were treated with four different enzymes in order to characterize the antibacterial substances against V. harveyi. The result showed considerable reduction of antibacterial activity for both strains, indicating the proteinaceous nature of the antibacterial substances. A wide range of tolerance to NaCl, pH and temperature was also recorded for both strains. In addition, both strains showed no virulence effect in juvenile shrimp Litopenaeus vannamei. On the basis of these results and safety of strains to L. vannamei, they may be considered for future challenge experiments in shrimp as a very promising alternative to the use of antibiotics.

Microbial interactions in drinking water biofilms

OpenAIRE

Simões, Lúcia C.; Simões, M.; Vieira, M. J.

2007-01-01

Drinking water distribution networks may be viewed as a large reactor where a number of chemical and microbiological processes are taking place. Control of microbial growth in drinking water distribution systems (DWDS) often achieved through the addition of disinfectants, is essential to limit the spread of waterborne pathogens. However, microorganisms can resist disinfection through protection within biofilms and resistant host cells. Recent studies into the microbial ecology ...

Antimicrobial susceptibility of intra-abdominal infection isolates from a tertiary care hospital in karachi

International Nuclear Information System (INIS)

Saad, U.; Anwar, S.; Kahara, U.Z.; Saeed, H.

2016-01-01

Intra-abdominal infections are associated with significant morbidity and mortality. The most frequent pathogens involved are the gastrointestinal flora which can cause poly-microbial infections. Microbiological diagnosis is required to determine the aetiology and antimicrobial susceptibility of the organisms involved. Prompt initiation of antimicrobials is essential for improving patient's outcome. Knowledge of local trends of antimicrobial resistance in nosocomial isolates is essential for empiric therapy. Methods: A total of 190 clinical isolates collected from intra-abdominal infections during July 2013 to July 2014 were included in the study. Organism identification and Antimicrobial sensitivity testing using standard biochemical tests and CLSI recommended criteria was carried out. Result: Of the total 190 isolates from abdominal infection sources 52% were from fluid sources (peritoneal and ascitic fluid), 41% were from gall bladder and 6.5% were from other abdominal sources. E. coli (46.8%) was the most frequently isolated gram negative and Enterococcus (13.1%) was the most frequently isolated gram positive organism. Carbapenem (imipenem) was the most active agent against enterobacteraceae exhibiting, 94.4% and 91.3% sensitivity against E. coli and Klebsiella respectively. While vancomycin was the most active agent against gram positive organisms. Eighty-four percent of the Enterococci isolated were sensitive to vancomycin. Most isolates exhibited resistance to one or more antibiotics. Conclusion: Continuous evolution of antimicrobial resistance patterns in bacteria necessitates updating of local data on antimicrobial susceptibility profiles to ensure the safety and efficacy of pathogen specific antimicrobial therapies. (author)

Pathogen self defense: mechanisms to counteract microbial antagonism

NARCIS (Netherlands)

Duffy, B.K.; Schouten, A.; Raaijmakers, J.M.

2003-01-01

Natural and agricultural ecosystems harbor a wide variety of microorganisms that play an integral role in plant health, crop productivity, and preservation of multiple ecosystem functions. Interactions within and among microbial communities are numerous and range from synergistic and mutualistic to

Molecular mimicry modulates plant host responses to pathogens.

Science.gov (United States)

Ronald, Pamela; Joe, Anna

2018-01-25

Pathogens often secrete molecules that mimic those present in the plant host. Recent studies indicate that some of these molecules mimic plant hormones required for development and immunity. This Viewpoint reviews the literature on microbial molecules produced by plant pathogens that functionally mimic molecules present in the plant host. This article includes examples from nematodes, bacteria and fungi with emphasis on RaxX, a microbial protein produced by the bacterial pathogen Xanthomonas oryzae pv. oryzae. RaxX mimics a plant peptide hormone, PSY (plant peptide containing sulphated tyrosine). The rice immune receptor XA21 detects sulphated RaxX but not the endogenous peptide PSY. Studies of the RaxX/XA21 system have provided insight into both host and pathogen biology and offered a framework for future work directed at understanding how XA21 and the PSY receptor(s) can be differentially activated by RaxX and endogenous PSY peptides. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effect of Lactobacillus sp. isolates supernatant on Escherichia coli O157:H7 enhances the role of organic acids production as a factor for pathogen control

Directory of Open Access Journals (Sweden)

Larissa B. Poppi

2015-04-01

Full Text Available Many attempts have been made to establish the control of foodborne pathogens through Lactobacillus isolates and their metabolism products with success being obtained in several situations. The aim of this study was to investigate the antagonistic effect of eight Lactobacillus isolates, including L. casei subsp. pseudoplantarum, L. plantarum, L. reuteri and L. delbrueckii subsp. delbrueckii, on the pathogenic Escherichia colistrain O157:H7. The inhibitory effect of pure cultures and two pooled cultures supernatants of Lactobacillus on the growth of pathogenic bacteria was evaluated by the spot agar method and by monitoring turbidity. Antimicrobial activity was confirmed for L. reuteri and L. delbrueckii subsp. delbrueckii and for a pool of lactic acid bacteria. The neutralized supernatant of the pool exerted a higher antimicrobial activity than that of the individual strains. Furthermore, D-lactic acid and acetic acid were produced during growth of the Lactobacillus isolates studied.

Long-term monitoring of waterborne pathogens and microbial source tracking markers in paired agricultural watersheds under controlled and conventional tile drainage management.

Science.gov (United States)

Wilkes, Graham; Brassard, Julie; Edge, Thomas A; Gannon, Victor; Gottschall, Natalie; Jokinen, Cassandra C; Jones, Tineke H; Khan, Izhar U H; Marti, Romain; Sunohara, Mark D; Topp, Edward; Lapen, David R

2014-06-01

Surface waters from paired agricultural watersheds under controlled tile drainage (CTD) and uncontrolled tile drainage (UCTD) were monitored over 7 years in order to determine if there was an effect of CTD (imposed during the growing season) on occurrences and loadings of bacterial and viral pathogens, coliphages, and microbial source tracking markers. There were significantly lower occurrences of human, ruminant, and livestock (ruminant plus pig) Bacteroidales markers in the CTD watershed in relation to the UCTD watershed. As for pathogens, there were significantly lower occurrences of Salmonella spp. and Arcobacter spp. in the CTD watershed. There were no instances where there were significantly higher quantitative loadings of any microbial target in the CTD watershed, except for F-specific DNA (F-DNA) and F-RNA coliphages, perhaps as a result of fecal inputs from a hobby farm independent of the drainage practice treatments. There was lower loading of the ruminant marker in the CTD watershed in relation to the UCTD system, and results were significant at the level P = 0.06. The odds of Salmonella spp. occurring increased when a ruminant marker was present relative to when the ruminant marker was absent, yet for Arcobacter spp., the odds of this pathogen occurring significantly decreased when a ruminant marker was present relative to when the ruminant marker was absent (but increased when a wildlife marker was present relative to when the wildlife marker was absent). Interestingly, the odds of norovirus GII (associated with human and swine) occurring in water increased significantly when a ruminant marker was present relative to when a ruminant marker was absent. Overall, this study suggests that fecal pollution from tile-drained fields to stream could be reduced by CTD utilization. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Long-Term Monitoring of Waterborne Pathogens and Microbial Source Tracking Markers in Paired Agricultural Watersheds under Controlled and Conventional Tile Drainage Management

Science.gov (United States)

Wilkes, Graham; Brassard, Julie; Edge, Thomas A.; Gannon, Victor; Gottschall, Natalie; Jokinen, Cassandra C.; Jones, Tineke H.; Khan, Izhar U. H.; Marti, Romain; Sunohara, Mark D.; Topp, Edward

2014-01-01

Surface waters from paired agricultural watersheds under controlled tile drainage (CTD) and uncontrolled tile drainage (UCTD) were monitored over 7 years in order to determine if there was an effect of CTD (imposed during the growing season) on occurrences and loadings of bacterial and viral pathogens, coliphages, and microbial source tracking markers. There were significantly lower occurrences of human, ruminant, and livestock (ruminant plus pig) Bacteroidales markers in the CTD watershed in relation to the UCTD watershed. As for pathogens, there were significantly lower occurrences of Salmonella spp. and Arcobacter spp. in the CTD watershed. There were no instances where there were significantly higher quantitative loadings of any microbial target in the CTD watershed, except for F-specific DNA (F-DNA) and F-RNA coliphages, perhaps as a result of fecal inputs from a hobby farm independent of the drainage practice treatments. There was lower loading of the ruminant marker in the CTD watershed in relation to the UCTD system, and results were significant at the level P = 0.06. The odds of Salmonella spp. occurring increased when a ruminant marker was present relative to when the ruminant marker was absent, yet for Arcobacter spp., the odds of this pathogen occurring significantly decreased when a ruminant marker was present relative to when the ruminant marker was absent (but increased when a wildlife marker was present relative to when the wildlife marker was absent). Interestingly, the odds of norovirus GII (associated with human and swine) occurring in water increased significantly when a ruminant marker was present relative to when a ruminant marker was absent. Overall, this study suggests that fecal pollution from tile-drained fields to stream could be reduced by CTD utilization. PMID:24727274

Whole genome sequencing of the monomorphic pathogen Mycobacterium bovis reveals local differentiation of cattle clinical isolates.

Science.gov (United States)

Lasserre, Moira; Fresia, Pablo; Greif, Gonzalo; Iraola, Gregorio; Castro-Ramos, Miguel; Juambeltz, Arturo; Nuñez, Álvaro; Naya, Hugo; Robello, Carlos; Berná, Luisa

2018-01-02

Bovine tuberculosis (bTB) poses serious risks to animal welfare and economy, as well as to public health as a zoonosis. Its etiological agent, Mycobacterium bovis, belongs to the Mycobacterium tuberculosis complex (MTBC), a group of genetically monomorphic organisms featured by a remarkably high overall nucleotide identity (99.9%). Indeed, this characteristic is of major concern for correct typing and determination of strain-specific traits based on sequence diversity. Due to its historical economic dependence on cattle production, Uruguay is deeply affected by the prevailing incidence of Mycobacterium bovis. With the world's highest number of cattle per human, and its intensive cattle production, Uruguay represents a particularly suited setting to evaluate genomic variability among isolates, and the diversity traits associated to this pathogen. We compared 186 genomes from MTBC strains isolated worldwide, and found a highly structured population in M. bovis. The analysis of 23 new M. bovis genomes, belonging to strains isolated in Uruguay evidenced three groups present in the country. Despite presenting an expected highly conserved genomic structure and sequence, these strains segregate into a clustered manner within the worldwide phylogeny. Analysis of the non-pe/ppe differential areas against a reference genome defined four main sources of variability, namely: regions of difference (RD), variable genes, duplications and novel genes. RDs and variant analysis segregated the strains into clusters that are concordant with their spoligotype identities. Due to its high homoplasy rate, spoligotyping failed to reflect the true genomic diversity among worldwide representative strains, however, it remains a good indicator for closely related populations. This study introduces a comprehensive population structure analysis of worldwide M. bovis isolates. The incorporation and analysis of 23 novel Uruguayan M. bovis genomes, sheds light onto the genomic diversity of this

Post-translational modification of host proteins in pathogen-triggered defence signalling in plants

NARCIS (Netherlands)

Stulemeijer, I.J.E.; Joosten, M.H.A.J.

2008-01-01

Microbial plant pathogens impose a continuous threat to global food production. Similar to animals, an innate immune system allows plants to recognize pathogens and swiftly activate defence. To activate a rapid response, receptor-mediated pathogen perception and subsequent downstream signalling

Monitoring of antimicrobial susceptibility of respiratory tract pathogens isolated from diseased cattle and pigs across Europe, 2009-2012: VetPath results.

Science.gov (United States)

El Garch, Farid; de Jong, Anno; Simjee, Shabbir; Moyaert, Hilde; Klein, Ulrich; Ludwig, Carolin; Marion, Hervé; Haag-Diergarten, Silke; Richard-Mazet, Alexandra; Thomas, Valérie; Siegwart, Ed

2016-10-15

VetPath is an ongoing pan-European antibiotic susceptibility monitoring programme that collects pathogens from diseased cattle, pigs and poultry. In the current study, 996 isolates from cattle and pig respiratory tract infections were tested for their antimicrobial susceptibilities. Non-replicate lung samples or nasopharyngeal/nasal swabs were collected from animals with acute clinical signs in 10 countries during 2009-2012. Pasteurella multocida, Mannheimia haemolytica and Histophilus somni from cattle and P. multocida, Actinobacillus pleuropneumoniae, Haemophilus parasuis, Bordetella bronchiseptica and Streptococcus suis from pigs were isolated by standard methods. S. suis was also isolated from meningitis cases. MIC values of 16 or 17 antibiotics were assessed centrally by broth microdilution following CLSI standards. Results were interpreted using CLSI breakpoints where available. Cattle isolates were generally highly susceptible to most antibiotics, except to tetracycline (3.0-12.0% resistance). Low levels of resistance (0-4.0%) were observed for the macrolide antibiotics. Resistance to spectinomycin varied from 0 to 6.0%. In pig isolates similar observations were made. Resistance to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin, florfenicol, tulathromycin, tiamulin and tilmicosin was absent or <2%. Trimethoprim/sulfamethoxazole resistance varied from 1.9 to 5.3%, but tetracycline resistance varied from 20.4% in P. multocida to 88.1% in S. suis. For most antibiotics and pathogens the percentage resistance remained unchanged or only increased numerically as compared to that of the period 2002-2006. In conclusion, absence or low resistance to antibiotics with defined clinical breakpoints, except for tetracycline, was observed among the major respiratory tract pathogens recovered from livestock. Comparison of all antibiotics and organisms was hampered since for almost half of the antibiotics no CLSI-defined breakpoints were available. Copyright © 2016

Streptococcus dysgalactiae subsp. dysgalactiae isolated from milk of the bovine udder as emerging pathogens: In vitro and in vivo infection of human cells and zebrafish as biological models.

Science.gov (United States)

Alves-Barroco, Cinthia; Roma-Rodrigues, Catarina; Raposo, Luís R; Brás, Catarina; Diniz, Mário; Caço, João; Costa, Pedro M; Santos-Sanches, Ilda; Fernandes, Alexandra R

2018-03-25

Streptococcus dysgalactiae subsp. dysgalactiae (SDSD) is a major cause of bovine mastitis and has been regarded as an animal-restricted pathogen, although rare infections have been described in humans. Previous studies revealed the presence of virulence genes encoded by phages of the human pathogen Group A Streptococcus pyogenes (GAS) in SDSD isolated from the milk of bovine udder with mastitis. The isolates SDSD VSD5 and VSD13 could adhere and internalize human primary keratinocyte cells, suggesting a possible human infection potential of bovine isolates. In this work, the in vitro and in vivo potential of SDSD to internalize/adhere human cells of the respiratory track and zebrafish as biological models was evaluated. Our results showed that, in vitro, bovine SDSD strains could interact and internalize human respiratory cell lines and that this internalization was dependent on an active transport mechanism and that, in vivo, SDSD are able to cause invasive infections producing zebrafish morbidity and mortality. The infectious potential of these isolates showed to be isolate-specific and appeared to be independent of the presence or absence of GAS phage-encoded virulence genes. Although the infection ability of the bovine SDSD strains was not as strong as the human pathogenic S. pyogenes in the zebrafish model, results suggested that these SDSD isolates are able to interact with human cells and infect zebrafish, a vertebrate infectious model, emerging as pathogens with zoonotic capability. © 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Dynamic Evolution of Pathogenicity Revealed by Sequencing and Comparative Genomics of 19 Pseudomonas syringae Isolates

Science.gov (United States)

Romanchuk, Artur; Chang, Jeff H.; Mukhtar, M. Shahid; Cherkis, Karen; Roach, Jeff; Grant, Sarah R.; Jones, Corbin D.; Dangl, Jeffery L.

2011-01-01

Closely related pathogens may differ dramatically in host range, but the molecular, genetic, and evolutionary basis for these differences remains unclear. In many Gram- negative bacteria, including the phytopathogen Pseudomonas syringae, type III effectors (TTEs) are essential for pathogenicity, instrumental in structuring host range, and exhibit wide diversity between strains. To capture the dynamic nature of virulence gene repertoires across P. syringae, we screened 11 diverse strains for novel TTE families and coupled this nearly saturating screen with the sequencing and assembly of 14 phylogenetically diverse isolates from a broad collection of diseased host plants. TTE repertoires vary dramatically in size and content across all P. syringae clades; surprisingly few TTEs are conserved and present in all strains. Those that are likely provide basal requirements for pathogenicity. We demonstrate that functional divergence within one conserved locus, hopM1, leads to dramatic differences in pathogenicity, and we demonstrate that phylogenetics-informed mutagenesis can be used to identify functionally critical residues of TTEs. The dynamism of the TTE repertoire is mirrored by diversity in pathways affecting the synthesis of secreted phytotoxins, highlighting the likely role of both types of virulence factors in determination of host range. We used these 14 draft genome sequences, plus five additional genome sequences previously reported, to identify the core genome for P. syringae and we compared this core to that of two closely related non-pathogenic pseudomonad species. These data revealed the recent acquisition of a 1 Mb megaplasmid by a sub-clade of cucumber pathogens. This megaplasmid encodes a type IV secretion system and a diverse set of unknown proteins, which dramatically increases both the genomic content of these strains and the pan-genome of the species. PMID:21799664

Electricity Generation in Microbial Fuel Cell (MFC) by Bacterium Isolated from Rice Paddy Field Soil

Science.gov (United States)

Fakhirruddin, Fakhriah; Amid, Azura; Salim, Wan Wardatul Amani Wan; Suhaida Azmi, Azlin

2018-03-01

Microbial fuel cell (MFC) is an alternative approach in generating renewable energy by utilising bacteria that will oxidize organic or inorganic substrates, producing electrons yielded as electrical energy. Different species of exoelectrogenic bacteria capable of generating significant amount of electricity in MFC has been identified, using various organic compounds for fuel. Soil sample taken from rice paddy field is proven to contain exoelectrogenic bacteria, thus electricity generation using mixed culture originally found in the soil, and pure culture isolated from the soil is studied. This research will isolate the exoelectrogenic bacterial species in the rice paddy field soil responsible for energy generation. Growth of bacteria isolated from the MFC is observed by measuring the optical density (OD), cell density weight (CDW) and viable cell count. Mixed bacterial species found in paddy field soil generates maximum power of 77.62 μW and 0.70 mA of current. In addition, the research also shows that the pure bacterium in rice paddy field soil can produce maximum power and current at 51.32 μW and 0.28 mA respectively.

Exserohilum rostratum: characterization of a cross-kingdom pathogen of plants and humans.

Directory of Open Access Journals (Sweden)

Kalpana Sharma

Full Text Available Pathogen host shifts represent a major source of new infectious diseases. There are several examples of cross-genus host jumps that have caused catastrophic epidemics in animal and plant species worldwide. Cross-kingdom jumps are rare, and are often associated with nosocomial infections. Here we provide an example of human-mediated cross-kingdom jumping of Exserohilum rostratum isolated from a patient who had received a corticosteroid injection and died of fungal meningitis in a Florida hospital in 2012. The clinical isolate of E. rostratum was compared with two plant pathogenic isolates of E. rostratum and an isolate of the closely related genus Bipolaris in terms of morphology, phylogeny, and pathogenicity on one C3 grass, Gulf annual rye grass (Lolium multiflorum, and two C4 grasses, Japanese stilt grass (Microstegium vimineum and bahia grass (Paspalum notatum. Colony growth and color, as well as conidia shape and size were the same for the clinical and plant isolates of E. rostratum, while these characteristics differed slightly for the Bipolaris sp. isolate. The plant pathogenic and clinical isolates of E. rostratum were indistinguishable based on morphology and ITS and 28S rDNA sequence analysis. The clinical isolate was as pathogenic to all grass species tested as the plant pathogenic strains that were originally isolated from plant hosts. The clinical isolate induced more severe symptoms on stilt grass than on rye grass, while this was the reverse for the plant isolates of E. rostratum. The phylogenetic similarity between the clinical and plant-associated E. rostratum isolates and the ability of the clinical isolate to infect plants suggests that a plant pathogenic strain of E. rostratum contaminated the corticosteroid injection fluid and was able to cause systemic disease in the affected patient. This is the first proof that a clinical isolate of E. rostratum is also an effective plant pathogen.

Multiple, novel biologically active endophytic actinomycetes isolated from upper Amazonian rainforests.

Science.gov (United States)

Bascom-Slack, Carol A; Ma, Cong; Moore, Emily; Babbs, Beatrice; Fenn, Kathleen; Greene, Joshua S; Hann, Bradley D; Keehner, Jocelyn; Kelley-Swift, Elizabeth G; Kembaiyan, Vivek; Lee, Sun Jin; Li, Puyao; Light, David Y; Lin, Emily H; Schorn, Michelle A; Vekhter, Daniel; Boulanger, Lori-Ann; Hess, W M; Vargas, Percy Núñez; Strobel, Gary A; Strobel, Scott A

2009-08-01

Microbial biodiversity provides an increasingly important source of medically and industrially useful compounds. We have isolated 14 actinomycete species from a collection of approximately 300 plant stem samples from the upper Amazonian rainforest in Peru. All of the cultured isolates produce substances with inhibitory activity directed at a range of potential fungal and bacterial pathogens. For some organisms, this activity is very broad in spectrum while other organisms show specific activity against a limited number of organisms. Two of these organisms preferentially inhibit bacterial test organisms over eukaryotic organisms. rDNA sequence analysis indicates that these organisms are not equivalent to any other cultured deposits in GenBank. Our results provide evidence of the untapped biodiversity in the form of biologically active microbes present within the tissues of higher plants.

Elucidation of bacteria found in car interiors and strategies to reduce the presence of potential pathogens

Science.gov (United States)

Stephenson, Rachel E.; Gutierrez, Daniel; Peters, Cindy; Nichols, Mark; Boles, Blaise R.

2014-01-01

The human microbiome is influenced by a number of factors, including environmental exposure to microbes. Because many humans spend a large amount of time in built environments, it can be expected that the microbial ecology of these environments will influence the human microbiome. In an attempt to further understand the microbial ecology of built environments, the microbiota of car interiors was analyzed using culture dependent and culture independent methods. While it was found that the number and type of bacteria varied widely among the cars and sites tested, Staphylococcus and Propionibacterium were nearly always the dominant genera found at the locations sampled. Because Staphylococcus is of particular concern to human health, the characteristics of this genus found in car interiors were investigated. Staphylococcus epidermidis, S. aureus, and S. warnerii were the most prevalent staphylococcal species found, and 22.6% of S. aureus strains isolated from shared community vehicles were resistant to methicillin. The reduction in the prevalence of pathogenic bacteria in cars by using silver-based antimicrobial surface coatings was also evaluated. Coatings containing 5% silver ion additives were applied to steering wheels, placed in cars for five months and were found to eliminate the presence of culturable pathogenic bacteria recovered from these sites relative to controls. Together, these results provide new insight into the microbiota found in an important built environment, the automobile, and potential strategies for controlling the presence of human pathogens. PMID:24564823

Isolation, identification of antagonistic rhizobacterial strains obtained from chickpea (cicer arietinum l.) field and their in-vitro evaluation against fungal root pathogens

International Nuclear Information System (INIS)

Shahzaman, S.; Haq, I.U.; Mukhtar, T.; Naeem, M.

2015-01-01

Plant growth promoting rhizobacteria (PGPR), are associated with roots, found in the rhizosphere and can directly or indirectly enhance the plant growth. In this study soil was collected from rhizosphere of chickpea fields of different areas of Rawalpindi division of Pakistan. PGPR were isolated, screened and characterized. Eight isolates of rhizobacteria (RHA, RPG, RFJ, RC, RTR, RT and RK) were isolated from Rawalpindi division and were characterized. The antagonistic activity of these PGPR isolates against root infecting fungi (Fusarium oxysporum and Verticillium spp.,) was done and production of indole acetic acid (IAA), siderophore and P-solubilization was evaluated. The isolates RHA, RPG, RFJ, RC, RRD and RT were found to be positive in producing siderophore, IAA and P-solubilization. Furthermore, most of the isolates showed antifungal activity against Fusarium oxysporum, and Verticillium spp. The rhizobacterial isolates RHA, RPG, RFJ, RC, RRD, RTR, RT and RK were used as bio-inoculants that might be beneficial for chickpea cultivation as the rhizobacterial isolates possessed the plant growth promoting characters i.e. siderophore, IAA production, phosphate solubilization. In in vitro tests, Pseudomonas sp. and Bacillus spp. inhibited the mycelial growth of the fungal root pathogens. The isolates (RHA and RPG) also significantly increased (60-70%) seed germination, shoot length, root length of the chickpea. The incidence of fungi was reduced by the colonization of RHA and RPG which enhanced the seedling vigor index and seed germination. The observations revealed that isolates RHA and RPG is quite effective to reduce the fungal root infection in greenhouse, and also increases seed yields significantly. These rhizobacterial isolates appear to be efficient yield increasing as well as effective biocontrol agent against fungal root pathogen. (author)

Prevalence and Antimicrobial Susceptibility Profiles of Pathogen Isolated from Bovine Mastitis Milk in Transylvania, Romania

Directory of Open Access Journals (Sweden)

Cosmina Bouari

2016-11-01

Full Text Available Mastitis in cows, one of the most common and economically important infectious diseases of dairy cattle, all over the world, with significant impact due to economic losses, occurs when the udder becomes inflamed because the leukocytes are released into the mammary gland usually in response to bacteria invasion of the teat canal. The main objective of this study was to evaluate the in vitro antimicrobial susceptibility of bacteria isolated from milk in order to design specific control programs for bovine mastitis in this area. A total of 204 milk samples aseptically collected both from farms and private owners were processed during May 2014 and March 2016 within the Microbiology Laboratory of the Faculty of Veterinary Cluj-Napoca, Romania. The microbiological examination was carried out by inoculation on blood agar and MacConkey medium. After the overnight incubation in aerobic conditions, the identification of the isolates was performed using microscopic, cultural and biochemical methods. Biochemical identification was based on API 20 Biomerieux system. Susceptibility to antibiotics was evaluated using Kirby Bauer disk diffusion method on Mueller-Hinton agar; the antibiotics were represented by Amoxicillin and Clavulanic Acid, Ceftiofur, Florfenicol, Mastidiscs, Enrofloxacin, Penicillin and Tetracycline. Staphylococcus spp. was the most common isolated pathogen, in 54.9% of the specimens, followed by Streptococcus spp. in 20.1%, Escherichia coli in 10.78%, Klebsiella spp. in 8.34%, Bacillus spp. in 5.88%. The most frequent associations were represented by staphylococci-streptococci in 62.7% of the samples, followed by streptococci-bacillus in 19.8% of the samples. The most important etiological agents identified were Staphylococcus aureus, S uberis, Streptococcus agalactiae, and Escherichia coli. Antimicrobial susceptibility test for the total isolates revealed good sensitivity to Enrofloxacin, Mastidiscs and Amoxicillin and Clavulanic Acid

ISOLATION AND MOLECULAR IDENTIFICATION OF POTENTIALLY PATHOGENIC Escherichia coli AND Campylobacter jejuni IN FERAL PIGEONS FROM AN URBAN AREA IN THE CITY OF LIMA, PERU

Science.gov (United States)

CABALLERO, Moisés; RIVERA, Isabel; JARA, Luis M.; ULLOA-STANOJLOVIC, Francisco M.; SHIVA, Carlos

2015-01-01

SUMMARY Feral pigeons (Columbia livia) live in close contact with humans and other animals. They can transmit potentially pathogenic and zoonotic agents. The objective of this study was to isolate and detect strains of diarrheagenic Escherichia coli and Campylobacter jejuni of urban feral pigeons from an area of Lima, Peru. Fresh dropping samples from urban parks were collected for microbiological isolation of E. coli strains in selective agar, and Campylobacter by filtration method. Molecular identification of diarrheagenic pathotypes of E.coli and Campylobacter jejuni was performed by PCR. Twenty-two parks were sampled and 16 colonies of Campylobacter spp. were isolated. The 100% of isolates were identified as Campylobacter jejuni. Furthermore, 102 colonies of E. coliwere isolated and the 5.88% resulted as Enteropathogenic (EPEC) type and 0.98% as Shiga toxin-producing E. coli (STEC). The urban feral pigeons of Lima in Peru can act as a reservoir or carriers of zoonotic potentially pathogenic enteric agents. PMID:26603225

Antagonistic activity of antibiotic producing Streptomyces sp. against fish and human pathogenic bacteria

Directory of Open Access Journals (Sweden)

Nazmul Hossain

2014-04-01

Full Text Available In this study, attempts were made to isolate Streptomyces sp. from soil samples of two different regions of Bangladesh and evaluate their antagonistic activity against fish and human pathogenic bacteria. A total of 10 isolates were identified as Streptomyces sp. based on several morphological, physiological and biochemical tests. Cross streak method was used to observe the antagonistic activity of the Streptomyces sp. isolates against different fish pathogens belonging to the genus Aeromonas, Pseudomonas and Edwardsiella and human clinical isolates belonging to the genus Klebsiella, Salmonella and Streptococcus. Seven Streptomyces sp. isolates showed antagonism against both fish and human pathogenic bacteria. Four isolates viz., N24, N26, N28 and N47 showed broad spectrum of antagonistic activity (80-100% against all genera of fish and human pathogenic bacteria. The isolate N49 exhibited highest spectrum of antagonism against all fish pathogens (90-100% but comparatively lower degree of antagonism against human pathogens (50-60%. Rest of the two isolates (N21 and N23 showed variability in their antagonism. Results showed that broad spectrum antibiotic(s could be developed from the isolates N24, N26, N28 and N47against several human and fish pathogens. The isolate N49 could be a potential source of antibiotic, especially for fish pathogenic bacteria.

Seleção de isolados de Beauveria bassiana patogênicos ao bicudo-do-algodoeiro Selection of isolates of Beauveria bassiana pathogenic to cotton boll weevil

Directory of Open Access Journals (Sweden)

Carlos Alberto Domingues da Silva

2001-02-01

Full Text Available Objetivou-se selecionar isolados de Beauveria bassiana (Balsamo Vüillemin provenientes de diferentes hospedeiros e regiões geográficas, patogênicos ao Anthonomus grandis, o bicudo-do-algodoeiro. Foram analisados 12 isolados em condições de laboratório. Os isolados obtidos originalmente de A. grandis foram pouco virulentos a essa praga. A mortalidade do bicudo teve início no segundo dia após a inoculação das suspensões fúngicas, variando de 15% a 83%, com TL50 entre 5,30 a 11,06 dias. Os isolados apresentaram variabilidade quanto à germinação dos conídios em meio de cultura artificial, e esta não se correlacionou com a patogenicidade. O isolado CG138 de B. bassiana destacou-se como um dos mais virulentos ao bicudo-do-algodoeiro.The objective of this work was to screen pathogenic isolates of Beauveria bassiana (Balsamo Vüillemin from different hosts and geographic regions, pathogenic to the cotton boll weevil. Twelve isolates were evaluated. Isolates originally obtained from boll weevil showed low pathogenicity against this host. Insect mortality began on the second day after inoculation by fungal suspension, ranging from 15% to 83%, with a TL50 of 5.30 to 11.06 days. Variability among isolates concerning conidial germination in artificial culture medium was verified, and TG50 did not correlate with pathogenicity. One of the most virulent isolates of B. bassiana against cotton boll weevil is CG138.

Isolation, characterization and HPLC quantification of compounds from Aquilegia fragrans Benth: Their in vitro antibacterial activities against bovine mastitis pathogens.

Science.gov (United States)

Mushtaq, Saleem; Aga, Mushtaq A; Qazi, Parvaiz H; Ali, Md Niamat; Shah, Aabid Manzoor; Lone, Sajad Ahmad; Shah, Aiyatullah; Hussain, Aehtesham; Rasool, Faheem; Dar, Hafizullah; Shah, Zeeshan Hamid; Lone, Shabir H

2016-02-03

The underground parts of Aquilegia fragrans are traditionally used for the treatment of wounds and various inflammatory diseases like bovine mastitis. However, there are no reports on the phytochemical characterization and antibacterial studies of A. fragrans. To isolate compounds from the methanol extract of the underground parts of A. fragrans and determine their antibacterial activity against the pathogens of bovine mastitis. The study was undertaken in order to scientifically validate the traditional use of A. fragrans. Five compounds were isolated from the methanol extract of the underground parts of A. fragrans using silica gel column chromatography. Structural elucidation of the isolated compounds was done using spectral data analysis and comparison with literature. High performance liquid chromatography (HPLC) was used for the qualitative and quantitative determination of isolated compounds in the crude methanol extract. The methanol extract and isolated compounds were evaluated for antibacterial activities against mastitis pathogens using broth micro-dilution technique. The five isolated compounds were identified as (1) 2, 4-dihydroxyphenylacetic acid methyl ester (2) β-sitosterol (3) Aquilegiolide (4) Glochidionolactone-A and (5) Magnoflorine. A quick and sensitive HPLC method was developed for the first time for qualitative and quantitative determination of four isolated marker compounds from A. fragrans. The crude methanol extract and compound 5 exhibited weak antibacterial activities that varied between the bacterial species (MIC=500-3000 µg/ml). The above results show that the crude methanol extract and isolated compounds from A. fragrans exhibit weak antibacterial activities. Further phytochemical and pharmacological studies are required for proper scientific validation of the folk use of this plant species in the treatment of various inflammatory diseases like bovine mastitis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Widespread distribution of a tet W determinant among tetracycline-resistant isolates of the animal pathogen Arcanobacterium pyogenes.

Science.gov (United States)

Billington, Stephen J; Songer, J Glenn; Jost, B Helen

2002-05-01

Tetracycline resistance is common among isolates of the animal commensal and opportunistic pathogen Arcanobacterium pyogenes. The tetracycline resistance determinant cloned from two bovine isolates of A. pyogenes was highly similar at the DNA level (92% identity) to the tet(W) gene, encoding a ribosomal protection tetracycline resistance protein, from the rumen bacterium Butyrivibrio fibrisolvens. The tet(W) gene was found in all 20 tetracycline-resistant isolates tested, indicating that it is a widely distributed determinant of tetracycline resistance in this organism. In 25% of tetracycline-resistant isolates, the tet(W) gene was associated with a mob gene, encoding a functional mobilization protein, and an origin of transfer, suggesting that the determinant may be transferable to other bacteria. In fact, low-frequency transfer of tet(W) was detected from mob+ A. pyogenes isolates to a tetracycline-sensitive A. pyogenes recipient. The mobile nature of this determinant and the presence of A. pyogenes in the gastrointestinal tract of cattle and pigs suggest that A. pyogenes may have inherited this determinant within the gastrointestinal tracts of these animals.

Pathogens\\' Reduction in Vermicompost Process Resulted from the Mixed Sludge Treatments-Household Wastes

OpenAIRE

Hossien Karimi; Mohammad Rezvani; Morteza Mohammadzadeh; Yaser Eshaghi; Mehdi Mokhtari

2016-01-01

Introduction: The presence of pathogenic microbial agents and pathogens in organic fertilizers causes health problems and disease transmission. The aim of this study was to evaluate the efficiency of vermicomposting process in improve the microbial quality of the compost produced. Materials and Methods: This experimental study was conducted as a pilot-scale one, in the laboratory of school of Health. In order to produce vermicompost, some perishable domestic waste were mixed whit sludge o...

A Customized DNA Microarray for Microbial Source Tracking ...

Science.gov (United States)

It is estimated that more than 160, 000 miles of rivers and streams in the United States are impaired due to the presence of waterborne pathogens. These pathogens typically originate from human and other animal fecal pollution sources; therefore, a rapid microbial source tracking (MST) method is needed to facilitate water quality assessment and impaired water remediation. We report a novel qualitative DNA microarray technology consisting of 453 probes for the detection of general fecal and host-associated bacteria, viruses, antibiotic resistance, and other environmentally relevant genetic indicators. A novel data normalization and reduction approach is also presented to help alleviate false positives often associated with high-density microarray applications. To evaluate the performance of the approach, DNA and cDNA was isolated from swine, cattle, duck, goose and gull fecal reference samples, as well as soiled poultry liter and raw municipal sewage. Based on nonmetric multidimensional scaling analysis of results, findings suggest that the novel microarray approach may be useful for pathogen detection and identification of fecal contamination in recreational waters. The ability to simultaneously detect a large collection of environmentally important genetic indicators in a single test has the potential to provide water quality managers with a wide range of information in a short period of time. Future research is warranted to measure microarray performance i

Comparative Genomics of a Plant-Pathogenic Fungus, Pyrenophora tritici-repentis, Reveals Transduplication and the Impact of Repeat Elements on Pathogenicity and Population Divergence

Energy Technology Data Exchange (ETDEWEB)

Manning, Viola A.; Pandelova, Iovanna; Dhillon, Braham; Wilhelm, Larry J.; Goodwin, Stephen B.; Berlin, Aaron M.; Figueroa, Melania; Freitag, Michael; Hane, James K.; Henrissat, Bernard; Holman, Wade H.; Kodira, Chinnappa D.; Martin, Joel; Oliver, Richard P.; Robbertse, Barbara; Schackwitz, Wendy; Schwartz, David C.; Spatafora, Joseph W.; Turgeon, B. Gillian; Yandava, Chandri; Young, Sarah; Zhou, Shiguo; Zeng, Qiandong; Grigoriev, Igor V.; Ma, Li-Jun; Ciuffetti, Lynda M.

2012-08-16

Pyrenophora tritici-repentis is a necrotrophic fungus causal to the disease tan spot of wheat, whose contribution to crop loss has increased significantly during the last few decades. Pathogenicity by this fungus is attributed to the production of host-selective toxins (HST), which are recognized by their host in a genotype-specific manner. To better understand the mechanisms that have led to the increase in disease incidence related to this pathogen, we sequenced the genomes of three P. tritici-repentis isolates. A pathogenic isolate that produces two known HSTs was used to assemble a reference nuclear genome of approximately 40 Mb composed of 11 chromosomes that encode 12,141 predicted genes. Comparison of the reference genome with those of a pathogenic isolate that produces a third HST, and a nonpathogenic isolate, showed the nonpathogen genome to be more diverged than those of the two pathogens. Examination of gene-coding regions has provided candidate pathogen-specific proteins and revealed gene families that may play a role in a necrotrophic lifestyle. Analysis of transposable elements suggests that their presence in the genome of pathogenic isolates contributes to the creation of novel genes, effector diversification, possible horizontal gene transfer events, identified copy number variation, and the first example of transduplication by DNA transposable elements in fungi. Overall, comparative analysis of these genomes provides evidence that pathogenicity in this species arose through an influx of transposable elements, which created a genetically flexible landscape that can easily respond to environmental changes.

Effect of UV-C irradiation on growth, sporulation and pathogenicity of cochliobolus sativus isolates

International Nuclear Information System (INIS)

Jawhar, M.; Arabi, M.I.E.

1999-12-01

More than 30 isolates of Cochliobolus sativus, the causal agent of common root rot disease; were collected from different regions of Syria. Seven of them were exposed to UV-C light for 40 or 60 h . at a dose rate of 2.52x10 -3 W/cm 2 . A significant increases in the mycelium growth and sporulation were detected (p<0.001). Within the studied range of UV wave length, these two parameters were increased upon increasing the period of exposure to UV-C light. The pathogenicity of four isolates was evaluated after 60 h. of UV irradiation. The response to UV irradiation varied among these isolates, and resulted in an increase in their virulence level (as assessed by evaluating disease severity on sub-crown internodes). Five barley genotypes possessing different levels of resistance to C. sativus were studied. Arabi Abiad was the most susceptible cultivar whereas, Taka 76 line was moderately susceptible. It is concluded that it is possible to implement the positive effect of low doses of UV-C in stimulating the sporulation of fungi, which are difficult to sporulate on artificial media. (author)

Biofilm formation by Salmonella Enteritidis and Salmonella Typhimurium isolated from avian sources is partially related with their in vivo pathogenicity.

Science.gov (United States)

Borges, Karen Apellanis; Furian, Thales Quedi; de Souza, Sara Neves; Menezes, Rafaela; de Lima, Diane Alves; Fortes, Flávia Bornancini Borges; Salle, Carlos Tadeu Pippi; Moraes, Hamilton Luiz Souza; Nascimento, Vladimir Pinheiro

2018-03-22

Salmonella Enteritidis and Salmonella Typhimurium are among the most prevalent serotypes isolated from salmonellosis outbreaks and poultry. Salmonella spp. have the capacity to form biofilms on several surfaces, which can favour survival in hostile environments, such as slaughterhouses. Salmonella strains present differences in pathogenicity. However, there is little information regarding the pathogenicity of S. Enteritidis and S. Typhimurium isolated from avian sources and their relationship to biofilm production. The aim of this study was to use a novel pathogenicity index and a biofilm production assay to evaluate their relationships within these serotypes. In addition, we detected the presence of the spiA and agfA genes in these strains. Biofilm formation was investigated at two temperatures (37 °C and 28 °C) using microtiter plate assay, and the results were compared with the individual pathogenicity index of each strain. PCR was used to detect spiA and agfA, virulence genes associated with biofilm production. S. Enteritidis and S. Typhimurium strains were capable of producing biofilm at 37 °C and 28 °C. Sixty-two percent and 59.5% of S. Enteritidis and 73.8% and 46.2% of S. Typhimurium produced biofilm at 37 °C and 28 °C, respectively. Biofilm production at 37 °C was significantly higher in both serotypes. Only S. Enteritidis was capable of adhering strongly at both temperatures. Biofilm production was related to pathogenicity index only at 28 °C for S. Enteritidis. spiA and agfA were found in almost all strains and were not statistically associated with biofilm production. Copyright © 2018 Elsevier Ltd. All rights reserved.

Enhancement of microbial quality and inactivation of pathogenic bacteria by gamma irradiation of ready-to-cook Iranian barbecued chicken

International Nuclear Information System (INIS)

Fallah, Aziz A.; Siavash Saei-Dehkordi, S.; Rahnama, Mohammad

2010-01-01

Ready-to-cook Iranian barbecued chicken consists of cubed chicken breast, lemon juice, salt, red pepper, onion, saffron and vegetable oil with an overall pH value of about 5.5. This product is sometimes consumed under-cooked, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. In this study, the effect of gamma irradiation (0, 1.5, 3 and 4.5 kGy) on the microbial quality of ready-to-cook (RTC) barbecued chicken samples stored at 4 o C for 15 days was investigated. Moreover, the effectiveness of irradiation for inactivating Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella typhimurium inoculated into the samples was also studied. Irradiation of the samples resulted in dose dependent reduction in counts of aerobic mesophilic bacteria, yeasts and molds, Enterobacteriaceae and lactic acid bacteria. Among the microbial flora, yeasts and molds and Enterobacteriaceae were more sensitive to irradiation and got completely eliminated at dose of 3 kGy. D 10 values of L. monocytogenes, E. coli O157:H7 and S. typhimurium inoculated into the samples were 0.680, 0.397 and 0.601 kGy, respectively. An irradiation dose of 3 kGy reduced the counts of E. coli O157:H7 to an undetectable level in RTC barbecued chicken but was ineffective on elimination of L. monocytogenes and S. typhimurium. However, none of the food-borne pathogens were detected in the samples irradiated at 4.5 kGy. This study showed that irradiation had no undesirable effects on the initial sensory attributes of barbecued chicken. At the end of the storage period, irradiated samples were more acceptable compared to non-irradiated ones.

Enhancement of microbial quality and inactivation of pathogenic bacteria by gamma irradiation of ready-to-cook Iranian barbecued chicken

Science.gov (United States)

Fallah, Aziz A.; Siavash Saei-Dehkordi, S.; Rahnama, Mohammad

2010-10-01

Ready-to-cook Iranian barbecued chicken consists of cubed chicken breast, lemon juice, salt, red pepper, onion, saffron and vegetable oil with an overall pH value of about 5.5. This product is sometimes consumed under-cooked, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. In this study, the effect of gamma irradiation (0, 1.5, 3 and 4.5 kGy) on the microbial quality of ready-to-cook (RTC) barbecued chicken samples stored at 4 °C for 15 days was investigated. Moreover, the effectiveness of irradiation for inactivating Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella typhimurium inoculated into the samples was also studied. Irradiation of the samples resulted in dose dependent reduction in counts of aerobic mesophilic bacteria, yeasts and molds, Enterobacteriaceae and lactic acid bacteria. Among the microbial flora, yeasts and molds and Enterobacteriaceae were more sensitive to irradiation and got completely eliminated at dose of 3 kGy. D10 values of L. monocytogenes, E. coli O157:H7 and S. typhimurium inoculated into the samples were 0.680, 0.397 and 0.601 kGy, respectively. An irradiation dose of 3 kGy reduced the counts of E. coli O157:H7 to an undetectable level in RTC barbecued chicken but was ineffective on elimination of L. monocytogenes and S. typhimurium. However, none of the food-borne pathogens were detected in the samples irradiated at 4.5 kGy. This study showed that irradiation had no undesirable effects on the initial sensory attributes of barbecued chicken. At the end of the storage period, irradiated samples were more acceptable compared to non-irradiated ones.

Enhancement of microbial quality and inactivation of pathogenic bacteria by gamma irradiation of ready-to-cook Iranian barbecued chicken

Energy Technology Data Exchange (ETDEWEB)

Fallah, Aziz A., E-mail: a_a_falah@yahoo.co [Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Shahre-Kord University, Shahre-Kord 34141 (Iran, Islamic Republic of); Research Institute of Zoonotic Diseases, Shahre-Kord University, Shahre-Kord 34141 (Iran, Islamic Republic of); Siavash Saei-Dehkordi, S. [Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Shahre-Kord University, Shahre-Kord 34141 (Iran, Islamic Republic of); Research Institute of Zoonotic Diseases, Shahre-Kord University, Shahre-Kord 34141 (Iran, Islamic Republic of); Rahnama, Mohammad [Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Zabol, Zabol 98615 (Iran, Islamic Republic of)

2010-10-15

Ready-to-cook Iranian barbecued chicken consists of cubed chicken breast, lemon juice, salt, red pepper, onion, saffron and vegetable oil with an overall pH value of about 5.5. This product is sometimes consumed under-cooked, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. In this study, the effect of gamma irradiation (0, 1.5, 3 and 4.5 kGy) on the microbial quality of ready-to-cook (RTC) barbecued chicken samples stored at 4 {sup o}C for 15 days was investigated. Moreover, the effectiveness of irradiation for inactivating Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella typhimurium inoculated into the samples was also studied. Irradiation of the samples resulted in dose dependent reduction in counts of aerobic mesophilic bacteria, yeasts and molds, Enterobacteriaceae and lactic acid bacteria. Among the microbial flora, yeasts and molds and Enterobacteriaceae were more sensitive to irradiation and got completely eliminated at dose of 3 kGy. D{sub 10} values of L. monocytogenes, E. coli O157:H7 and S. typhimurium inoculated into the samples were 0.680, 0.397 and 0.601 kGy, respectively. An irradiation dose of 3 kGy reduced the counts of E. coli O157:H7 to an undetectable level in RTC barbecued chicken but was ineffective on elimination of L. monocytogenes and S. typhimurium. However, none of the food-borne pathogens were detected in the samples irradiated at 4.5 kGy. This study showed that irradiation had no undesirable effects on the initial sensory attributes of barbecued chicken. At the end of the storage period, irradiated samples were more acceptable compared to non-irradiated ones.

Imipenem/cilastatin encapsulated polymeric nanoparticles for destroying carbapenem-resistant bacterial isolates.

Science.gov (United States)

Shaaban, Mona I; Shaker, Mohamed A; Mady, Fatma M

2017-04-11

Carbapenem-resistance is an extremely growing medical threat in antibacterial therapy as the incurable resistant strains easily develop a multi-resistance action to other potent antimicrobial agents. Nonetheless, the protective delivery of current antibiotics using nano-carriers opens a tremendous approach in the antimicrobial therapy, allowing the nano-formulated antibiotics to beat these health threat pathogens. Herein, we encapsulated imipenem into biodegradable polymeric nanoparticles to destroy the imipenem-resistant bacteria and overcome the microbial adhesion and dissemination. Imipenem loaded poly Ɛ-caprolactone (PCL) and polylactide-co-glycolide (PLGA) nanocapsules were formulated using double emulsion evaporation method. The obtained nanocapsules were characterized for mean particle diameter, morphology, loading efficiency, and in vitro release. The in vitro antimicrobial and anti adhesion activities were evaluated against selected imipenem-resistant Klebsiella pneumoniae and Pseudomonas aeruginosa clinical isolates. The obtained results reveal that imipenem loaded PCL nano-formulation enhances the microbial susceptibility and antimicrobial activity of imipenem. The imipenem loaded PCL nanoparticles caused faster microbial killing within 2-3 h compared to the imipenem loaded PLGA and free drug. Successfully, PCL nanocapsules were able to protect imipenem from enzymatic degradation by resistant isolates and prevent the emergence of the resistant colonies, as it lowered the mutation prevention concentration of free imipenem by twofolds. Moreover, the imipenem loaded PCL eliminated bacterial attachment and the biofilm assembly of P. aeruginosa and K. pneumoniae planktonic bacteria by 74 and 78.4%, respectively. These promising results indicate that polymeric nanoparticles recover the efficacy of imipenem and can be considered as a new paradigm shift against multidrug-resistant isolates in treating severe bacterial infections.

ASSESSMENT OF THE BIODIVERSITY OF SAMPLES USED FOR ISOLATION OF MICROBIAL STRAINS CAPABLE OF CONVERTING STRAW DESTINED AS A SUBSTRATE FOR BIOGAS PLANT

Directory of Open Access Journals (Sweden)

Krystyna Cybulska

2016-01-01

Full Text Available In biogas plants, almost any type of organic matter can be used as a substrate to produce biogas. To make the process of methane fermentation more effective, these materials are pretreated. This applies in particular to a group of difficult substrates. Straw, due to its hemicellulose structure and saturation, is hardly fermented by biogas reactor microorganisms. The methods of post-harvest residue preparation for anaerobic digestion being applied so far are expensive, while their application has a negative effect on methanoegenic bacteria. Therefore, the microorganisms being able to degrade straw hemicellulose structure, utilisation of which could precede the proper fermentation process, have been searched for. This paper presents the results of microbial biodiversity analysis in the environmental samples being lupin, cereal, rape and maize straw as well as hay and haylage at different degradation stages. The analysis of biodiversity will help at a further stage of study to isolate active microbial strains showing cellulolytic, hemicellulolytic or ligninolytic activity which are desirable in the process of straw biodegradation. Analysis of the microbial count was performed by the method of deep inoculation on different microbiological culture media. The conducted tests include determination of the number of fungi, bacteria and actinomycetes. The results obtained confirm the usefulness of the analysed samples for isolation of microbial strains capable of converting straw preceding the biogas production.

Microbial minimalism: genome reduction in bacterial pathogens.

Science.gov (United States)

Moran, Nancy A

2002-03-08

When bacterial lineages make the transition from free-living or facultatively parasitic life cycles to permanent associations with hosts, they undergo a major loss of genes and DNA. Complete genome sequences are providing an understanding of how extreme genome reduction affects evolutionary directions and metabolic capabilities of obligate pathogens and symbionts.

Antimicrobial susceptibility monitoring of respiratory tract pathogens isolated from diseased cattle and pigs across Europe: the VetPath study.

Science.gov (United States)

de Jong, Anno; Thomas, Valérie; Simjee, Shabbir; Moyaert, Hilde; El Garch, Farid; Maher, Kirsty; Morrissey, Ian; Butty, Pascal; Klein, Ulrich; Marion, Hervé; Rigaut, Delphine; Vallé, Michel

2014-08-06

VetPath is an ongoing pan-European antibiotic susceptibility monitoring programme collecting pathogens from diseased antimicrobial non-treated cattle, pigs and poultry. In the current study, 1001 isolates from cattle and pig respiratory tract infections were tested for their antimicrobial susceptibilities. Non-replicate lung samples or nasopharyngeal/nasal swabs were collected from animals with acute clinical signs in 11 countries during 2002-2006. Pasteurella multocida and Mannheimia haemolytica from cattle and P. multocida, Actinobacillus pleuropneumoniae and Streptococcus suis from pigs were isolated by standard methods. S. suis was also isolated from meningitis cases. MICs of 16 antibiotics were assessed centrally by broth microdilution following CLSI recommendations. Results were interpreted using CLSI breakpoints where available. P. multocida (231) and M. haemolytica (138) isolates were all susceptible to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin and trimethoprim/sulfamethoxazole. Resistance to florfenicol and spectinomycin was 0.4% and 3.5% in P. multocida, respectively, and absent in M. haemolytica isolates. Tetracycline resistance was 5.7% and 14.6% for P. multocida and M. haemolytica. In pigs, 230 P. multocida, 220 A. pleuropneumoniae and 182 S. suis isolates were recovered. Resistance to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin, florfenicol, tiamulin and tilmicosin was absent or <1%. Trimethoprim/sulfamethoxazole resistance was 3-6% and tetracycline resistance varied from 14.7% in A. pleuropneumoniae to 81.8% in S. suis. In conclusion, low resistance to antibiotics with defined clinical breakpoints, except for tetracycline, was observed among the major respiratory tract pathogens recovered from cattle and pigs. Since for approximately half of the antibiotics in this panel no CLSI-defined breakpoints were available, setting of the missing veterinary breakpoints is important. Copyright © 2014 Elsevier B.V. All rights reserved.

Microbial Diversity in Milk of Women With Mastitis: Potential Role of Coagulase-Negative Staphylococci, Viridans Group Streptococci, and Corynebacteria.

Science.gov (United States)

Mediano, Pilar; Fernández, Leonides; Jiménez, Esther; Arroyo, Rebeca; Espinosa-Martos, Irene; Rodríguez, Juan M; Marín, María

2017-05-01

Lactational mastitis constitutes a significant cause of premature weaning. However, its etiology, linked to the presence of pathogenic microorganisms, has been scarcely reported. Research aim: The aim of this study was to describe the microbial diversity in milk samples from women suffering from lactational mastitis and to identify more accurately a collection of isolates belonging to coagulase-negative staphylococci, streptococci, and coryneform bacteria. This is a cross-sectional descriptive one-group study. A total of 5,009 isolates from 1,849 mastitis milk samples was identified by culture, biochemical, and/or molecular methods at the species or genus level. A more precise identification of a collection of 211 isolates was carried out by 16S rRNA gene sequencing. Mean total bacterial count in milk samples was 4.11 log 10 colony-forming units/ml, 95% confidence interval [4.08, 4.15]. Staphylococcus epidermidis was the most common species being isolated from 91.56% of the samples, whereas Staphylococcus aureus was detected in 29.74%. Streptococci and corynebacteria constituted the second (70.20%) and third (16.60%) most prevalent bacterial groups, respectively, found in this study. In contrast, Candida spp. was present in only 0.54% of the samples. Sequencing of the 16S rRNA gene revealed a high diversity of bacterial species among identified isolates. Many coagulase-negative staphylococci, viridans group streptococci, and corynebacteria, usually dismissed as contaminant bacteria, may play an important role as etiologic agents of mastitis. Proper diagnosis of mastitis should be established after performing microbiological testing of milk based on standardized procedures. A reliable analysis must identify the mastitis-causing pathogen(s) at the species level and its(their) concentration(s).

Compatibility study of Trichoderma harzianum Rifai and rice fungicides, and effects on three fungal plant pathogens

Directory of Open Access Journals (Sweden)

Manuel Francisco Rodríguez Saldaña

2017-04-01

Full Text Available This research took place at the Provincial Plant Sanitation Laboratory, in Camaguey, Cuba, between September 2013 and September 2015. The in vitro compatibility and antagonistic capacity of Trichoderma harzianum Rifai (strain A-34 on rice pathogens (Bipolaris oryzae Breda de Haan, Sarocladium oryzae (Sawada w., Gams and D. Hawksworth and Magnaporthe grisea (Hebert Barr, was determined against pesticides used on rice. Assessment using traditional methods of microbiological isolation of mycelial growth, sporulation and conidial germination of the antagonist, to determine if the action mechanisms (antibiosis, competence, parasitism against fungal pathogens, was made between 24 and 216 hours of application. A bifactorial design in dual culture was used for statistical analysis, along with scales for determination of microbial antagonistic capacity. Active ingredients tebuconazol + procloraz, trifloxistrobin+ ciproconazole, and epoxiconazole + kresoxim-methyl, affected mycelial growth of the antagonist. Moreover, the antagonist against active ingredients carbendazim, copper oxychloride, azoxystrobin and tebuconazo + triadimenol showed mycelial growth, sporulation and pathogen interaction, affecting their growth by means of coiling, penetration, granulation, and cell lysis, between 96 and 216 hours.

Pathogenicity and diversity of vegetative compatibility of Fusarium verticillioides

Directory of Open Access Journals (Sweden)

Krnjaja Vesna S.

2007-01-01

Full Text Available Pathogenicity of 10 Fusarium verticillioides isolates, originated from grain of wheat (five isolates and maize (five isolates, were studied under greenhouse conditions. Based on different parameters of the pathogenicity estimate (a scale for % of nonemerged plants, % of survived plants, plant vigour - the growth and dry weight of roots and epicotyls and disease severity it was determined that all F. verticillioides isolates expressed a different degree of pathogenicity. According to % of nonemerged plants six three and one F. verticillioides isolates expressed low, moderate and high degree of pathogenicity, respectively. All F. verticillioides isolates reduced the plant survival rate and vigour, while the disease severity ranged from 2.0 to 3.54. Two types of nit mutants, nit1 and NitM, were obtained by the use of the method of vegetative compatibility. The frequency of nit1 mutants was greater (58.79% than the frequency of NitM mutants (5.77%. A total of 10 vegetative compatibility groups (VCGs of F. verticillioides were established in the complementation tests. These results point out to a high genetic diversity of F. verticillioides population.

[Evaluation of Fusarium spp. pathogenicity in plant and murine models].

Science.gov (United States)

Forero-Reyes, Consuelo M; Alvarado-Fernández, Angela M; Ceballos-Rojas, Ana M; González-Carmona, Lady C; Linares-Linares, Melva Y; Castañeda-Salazar, Rubiela; Pulido-Villamarín, Adriana; Góngora-Medina, Manuel E; Cortés-Vecino, Jesús A; Rodríguez-Bocanegra, María X

The genus Fusarium is widely recognized for its phytopathogenic capacity. However, it has been reported as an opportunistic pathogen in immunocompetent and immunocompromised patients. Thus, it can be considered a microorganism of interest in pathogenicity studies on different hosts. Therefore, this work evaluated the pathogenicity of Fusarium spp. isolates from different origins in plants and animals (murine hosts). Twelve isolates of Fusarium spp. from plants, animal superficial mycoses, and human superficial and systemic mycoses were inoculated in tomato, passion fruit and carnation plants, and in immunocompetent and immunosuppressed BALB/c mice. Pathogenicity tests in plants did not show all the symptoms associated with vascular wilt in the three plant models; however, colonization and necrosis of the vascular bundles, regardless of the species and origin of the isolates, showed the infective potential of Fusarium spp. in different plant species. Moreover, the pathogenicity tests in the murine model revealed behavioral changes. It was noteworthy that only five isolates (different origin and species) caused mortality. Additionally, it was observed that all isolates infected and colonized different organs, regardless of the species and origin of the isolates or host immune status. In contrast, the superficial inoculation test showed no evidence of epidermal injury or colonization. The observed results in plant and murine models suggest the pathogenic potential of Fusarium spp. isolates in different types of hosts. However, further studies on pathogenicity are needed to confirm the multihost capacity of this genus. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Optimise the microbial flora with milk and yoghurt to prevent disease.

Science.gov (United States)

Morris, James A

2018-05-01

Pathogenic bacteria, which are temporary or permanent members of our microbial flora, cause or contribute to a wide range of human disease at all ages. Conditions include Alzheimer's disease, atherosclerosis, diabetes mellitus, obesity, cancer, autoimmunity and psychosis, amongst others. The mechanism of damage is inflammation which can be chronic or acute. An optimal microbial flora includes a wide range of pathogenic bacteria in low dose. This allows specific immunity to be developed and maintained with minimal inflammatory damage. Human milk has evolved to deliver an optimal microbial flora to the infant. Cow's milk has the potential, following appropriate fortification, to maintain an optimal human microbial flora throughout life. Yoghurt is a fermented milk product in which bacteria normally present in milk convert sugars to lactic acid. The acid suppresses the growth of pathogens in the oral cavity, oropharynx and oesophagus. Thus yoghurt can restore an optimal flora in these regions in the short term. Since bacteria are transported between epithelial surfaces, yoghurt will also optimise the flora elsewhere. The judicious use of milk and yogurt could prevent a high proportion of human disease. Copyright © 2018 The Author. Published by Elsevier Ltd.. All rights reserved.