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1.
Article in English | LILACS, BBO | ID: biblio-1101286

ABSTRACT

Abstract Objective: To evaluate the best strategy for pacifier disinfection methods. Material and Methods: The literature search was conducted on MEDLINE/PubMed, Scielo, Lilacs, Web of Science, and Scopus databases to find all relevant articles published over the past 20 years, based on PRISMA guidelines. Two reviewers extracted data independently by using a standardized form. The following factors were recorded: country of study, type of study, pacifier material, sample number, microorganisms analyzed, decontamination methods used, method accessibility and results found. Results: A total of 121 articles were obtained from all databases. The selected documents underwent a final screening, resulting in 8 articles. The method of disinfection analyzed by the literature were: 3.5% neutral detergent, apple cider vinegar 70% spray, boiling water during 15 minutes, sodium hypochlorite 2.5, hydrogen peroxide 70% spray, chlorhexidine 0.12%, Brushtox®, sterile water and microwave. Conclusion: Because of the broad methods for pacifier disinfection and different levels of accessibility to disinfectant agents, the pacifier consensus for decontamination remains unclear. Although the disinfection methods are diverse, the methods suggested to its disinfection were identified and described in this article.


Subject(s)
Sucking Behavior , Decontamination , Coronavirus , Pacifiers/microbiology , Environmental Microbiology , Brazil , Disinfection , Data Interpretation, Statistical
2.
Rev. chil. infectol ; 36(5): 585-590, oct. 2019. graf
Article in Spanish | LILACS | ID: biblio-1058084

ABSTRACT

Resumen Introducción: Listeria monocytogenes es un patógeno transmitido por alimentos que causa listeriosis, una enfermedad que puede presentarse como gastroenteritis febril o en una forma invasora que tiene altas tasas de mortalidad. Hasta el momento, ha sido poco estudiada la diversidad genética de cepas de L. monocytogenes aisladas desde pacientes, alimentos y fuentes ambientales en Chile. Objetivo: Caracterizar genéticamente cepas de L. monocytogenes de estos tres orígenes recibidas por el Instituto de Salud Pública de Chile (ISP) entre los años 2007 y 2014. Material y Métodos: Se seleccionaron 94 cepas de L. monocytogenes correspondientes a 94 pulsotipos diferentes identificados por electroforesis en gel de campo pulsado (PFGE), se extrajo ADN y se realizó serotipificación mediante reacción de polimerasa en cadena (RPC) y tipificación de secuencias multilocus (MLST). Resultados: El serotipo más común fue 4b (55,3%), seguido de 1/2a (25,5%), 1/2b (17%) y 1/2c (2,2%). Se identificaron 32 secuencias tipo (ST), de las cuales cuatro fueron nuevas, y las predominantes fueron ST1 (28,7%) y ST2 (13,8%). La totalidad de las cepas se agrupó en los Linajes I y II. Conclusiones: Se observó una gran variabilidad genética en las cepas de L. monocytogenes analizadas, siendo predominantes las secuencias tipo ST1 y ST2, ambas pertenecientes al Linaje I. Nuestros resultados contribuyen a conocer la estructura poblacional de este patógeno en Chile y su presencia en muestras clínicas, alimentos y el medio ambiente.


Background: Listeria monocytogenes is a foodborne pathogen that causes listeriosis, a disease that can present as febrile gastroenteritis or as an invasive form that has high mortality rates. So far, the genetic diversity of strains of L. monocytogenes isolated from patients, foods and environmental sources in Chile has been poorly studied. Aim: To characterize genetically L. monocytogenes strains received by the Institute of Public Health of Chile (ISP) between 2007 and 2014. Methods: We selected 94 strains of L. monocytogenes corresponding to 94 different pulsotypes identified by pulsed field gel electrophoresis (PFGE), DNA was extracted and serotyping was performed by polymerase chain reaction (PCR) and multilocus sequence typing (MLST). Results: The most common serotype was 4b (55.3%), followed by serotypes 1/2a (25.5%), 1/2b (17%) and 1/2c (2.2%). 32 sequence-type (ST) were identified, of which 4 were new, and the predominant ones were ST1 (28.7%) and ST2 (13.8%). All the strains of L. monocytogenes were grouped in Lineages I and II. Conclusions: A great genetic variability was observed in the strains of L. monocytogenes analyzed, being predominant the ST1 and ST2, both belonging to Lineage I. Our results contribute to know the population structure of this pathogen in Chile and its presence in clinical samples, food and the environment.


Subject(s)
Humans , Listeria monocytogenes/isolation & purification , Listeria monocytogenes/genetics , Time Factors , Genetic Variation , Serotyping , Chile , Polymerase Chain Reaction , Electrophoresis, Gel, Pulsed-Field , Environmental Microbiology , Multilocus Sequence Typing , Food Microbiology , Listeriosis/microbiology
3.
Braz. j. biol ; 79(2): 191-200, Apr.-June 2019. tab, graf
Article in English | LILACS | ID: biblio-989448

ABSTRACT

Abstract The hygienic and sanitary control in Food and Nutrition Units (FNU) is considered a standard procedure to produce adequate meals and reduce the risk of foodborne diseases and hospital infections. This study aimed to evaluate the isolation and identification of bacteria from equipment and food contact surfaces in a hospital FNU as well as to evaluate the sanitary condition. Likewise, it was analyzed the adhesion of the microorganisms on polyethylene cutting boards. The presence of aerobic mesophilic microorganisms, yeasts, molds, coagulase-positive staphylococci, coliform and fecal coliform, and Escherichia coli were analyzed on eating tables, countertop surfaces and cutting boards used for meat or vegetable handling, and equipment such as microwaves and refrigerators. The molecular identification it was done by 16S rRNA gene sequencing. The adhesion of the microorganisms (biofilm formation) on meat and vegetable cutting boards was also evaluated by scanning electron microscopy. The results showed high numbers of all microorganisms, except for E. coli , which was not observed in the samples. The molecular analysis identified species of the Enterobacteriaceae family and species of the Pseudomonadaceae family. Scanning electron microscopy analyses revealed bacterial adhesion on the cutting board surfaces. The results obtained in this study indicated that the hygienic conditions of surfaces like plastic cutting boards and equipment in this hospital FNU were inadequate. The achievement and application of standard operating procedures could positively help in the standardization of sanitary control, reducing the microbial contamination and providing a safe food to hospitalized patients.


Resumo O controle higiênico e sanitário nas Unidades de Alimentação e Nutrição (UAN) é considerado um procedimento padrão para produzir refeições adequadas e reduzir o risco de doenças transmitidas pelos alimentos e infecções hospitalares. Este estudo teve como objetivo isolar e identificar bactérias de equipamentos e superfícies de contato com alimentos em uma UAN hospitalar, bem como avaliar a condição sanitária. Do mesmo modo, analisou-se a adesão dos micro-organismos em tábuas de corte de polietileno. A presença de micro-organismos aeróbios mesófilos, leveduras, fungos, Sthapylococcus coagulase-positivos, coliformes, coliformes fecais e Escherichia coli foi analisadas na superfície de mesas do refeitório, superfícies de bancada e tábuas de corte usadas para manuseio de carne ou vegetais e, em equipamentos como micro-ondas e refrigeradores. A identificação molecular foi feita pelo sequenciamento do gene 16S rRNA. A adesão dos micro-organismos (formação de biofilmes) em tábuas de corte de carne e de vegetais também foi avaliada por microscopia eletrônica de varredura. Os resultados mostraram elevada contagem para todos os micro-organismos analisados, exceto para E. coli, a qual não foi observada nas amostras. A análise molecular identificou espécies da família Enterobacteriaceae e Pseudomonadaceae. A análise de microscopia eletrônica de varredura revelaram adesão bacteriana nas superfícies das placsa de corte. Os resultados obtidos neste estudo indicaram que as condições higiênicas das superfícies e de equipamentos nesta UAN hospitalar estavam inadequadas. A aplicação de procedimentos operacionais padrão poderia auxiliar positivamente na padronização do controle higiênico-sanitário, reduzindo a contaminação microbiana e fornecendo um alimento seguro para pacientes hospitalizados.


Subject(s)
Humans , Environmental Microbiology , Molecular Typing , Food Microbiology , Food Service, Hospital/trends , Bacteria/isolation & purification , Bacteria/classification , Bacteria/genetics , Biofilms , Fungi/isolation & purification , Fungi/classification , Fungi/genetics
4.
Rev. biol. trop ; 67(1): 132-145, Jan.-Mar. 2019. tab, graf
Article in English | LILACS | ID: biblio-1041900

ABSTRACT

Abstract Mosquitoes (Diptera: Culicidae) are important vectors of diverse pathogenic organisms, particularly arboviruses and protozoa. The immature stages of mosquitoes occur in a wide range of natural or human-made aquatic habitats. On this basis, some anthropogenic places such as cemeteries, usually serve as thrive and productive artificial-breeding habitats for mosquitoes. Despite being important foci for vector species, urban cemeteries are frequently overlooked in control and surveillance programs. This study evaluates the association of ecological variables and attributes (type of material, presence of flowers, water availability and height from the ground) of the breeding sites with the levels of infestation of mosquito immature stages. In 2017, an entire urban cemetery in Jarabacoa (Dominican Republic) was sampled at two different climatic periods (March: dry and August: rainy) for the characterization of the artificial breeding-sites, collection of immature stages of culicids and subsequent laboratory rearing for species identification. In total 968 containers were studied, containing 7 758 immature stages in 203 (21.0 %) water-filled containers which accounted for four species: Culex quinquefasciatus (50.5 %), Aedes aegypti (47.1 %), Aedes albopictus (1.9 %) and Culex nigripalpus (0.4 %). The mean of A. aegypti immatures in infested containers was roughly two times higher compared to C. quinquefasciatus and significantly lower compared to A. albopictus. The total Container Index (CI) was 20.9 %, and among the type of materials, those made from rock (cement, ceramic, and mud) and plastic had the highest CI = 25.9 % and 23.4 %, respectively. Almost 95 % of the total infested water-filled containers were made of plastic or rock. No association was found between the type of material of the containers and the density of mosquitoes. However, overall, greater densities of immature stages were found at ground than at higher levels. A weak positive correlation between water volume and density was found in some species of immature stages. Significantly higher number of C. quinquefasciatus were recorded in containers with flowers and large water volume. In contrast, A. aegypti immature stages were more frequent in containers without flowers. A weak negative association between water volume and infestations was found for A. albopictus immatures. As reflected of their opportunistic behaviour and broad ecological plasticity, Culex spp. and Aedes spp. mosquitoes were abundant pests in cemetery habitats where were able to breed in almost any kind of water-filled container regardless the type of material. However, our study showed that some ecological variables have critical impact for the development of the immature stages of some species. The health authorities and cemetery keepers can benefit from these results by focusing on the implementation of detailed plans and integrated strategies for the control and prevention of cemetery infestations by mosquitoes.(AU)


Resumen Los mosquitos (Diptera: Culicidae) son importantes vectores de diversos organismos patógenos, tales como arbovirus y protozoos. Los estadios inmaduros de los mosquitos pueden encontrarse en un amplio abanico de hábitats, tanto de origen natural como humano. Algunos lugares antrópicos, como los cementerios, sirven como prósperos hábitats artificiales para el desarrollo del ciclo de vida de los mosquitos. A pesar de constituir importantes focos para especies de interés vectorial, los cementerios urbanos son frecuentemente olvidados en los programas de vigilancia y control. Este estudio evaluó la asociación de algunas variables ecológicas (tipo de material, presencia de flores, disponibilidad de agua, y altura respecto al suelo) de los lugares de cría (recipientes) con los niveles de infestación de las fases preimarginales de los culícidos. En 2017, un cementerio urbano en Jarabacoa (República Dominicana) fue inspeccionado durante dos periodos climáticos (es decir: marzo: estación seca y agosto: estación húmeda) para: caracterizar los lugares de cría artificiales, captura de los estadios inmaduros de culícidos e identificación de los adultos emergidos a partir de las fases inmaduras. En total, 968 recipientes fueron examinados, conteniendo 7 758 inmaduros en 203 (21.0 %) recipientes con agua pertenecientes a cuatro especies, Culex quinquefasciatus (50.5 %), Aedes aegypti (47.1 %), Aedes albopictus (1.9 %) y Culex nigripalpus (0.4 %). El índice de recipiente (IR) fue del 20.9 %, y los recipientes fabricados a partir de roca (cemento, cerámica y barro) y plástico tuvieron el mayor IR = 25.9 y 23.4 %, respectivamente. Casi un 95 % de los recipientes con agua infectados estaban constituidos de materiales tipo plástico o roca. No se encontró asociación entre el tipo de material del recipiente y la densidad. En general, mayor densidad de estadios inmaduros fue observada a nivel del suelo que a alturas mayores. Se observó un incremento significativo del número de C. quinquefasciatus en recipientes con flores y grandes volúmenes de agua. Por el contrario, los estadios de A. aegypti fueron más frecuentes en recipientes sin flores. Como reflejo de su comportamiento oportunista y amplia plasticidad ecológica, los mosquitos Culex y Aedes fueron abundantes en los cementerios, siendo capaces de desarrollar su ciclo de vida acuático en cualquier tipo de recipiente, con independencia del material que lo constituya. Nuestro estudio, por tanto, mostró que algunas variables ecológicas tienen un impacto crítico sobre el desarrollo de los estadios inmaduros de algunas especies de mosquitos. Tanto las autoridades de salud pública como los cuidadores del cementerio pueden beneficiare de estos resultados centrándose en la implementación de planes detallados y estrategias integradoras para el control y prevención de mosquitos que infectan cementerios.(AU)


Subject(s)
Aedes/pathogenicity , Culex/pathogenicity , Environmental Microbiology , Cemeteries , Dominican Republic
5.
Rev. méd. Chile ; 147(1): 24-33, 2019. tab
Article in Spanish | LILACS | ID: biblio-991369

ABSTRACT

Background: Salmonella Heidelberg (S. Heidelberg) causes gastroenteritis and sometimes bacteremia and endocarditis. In other countries, this serovar has multidrug resistance including extended-spectrum β-lactamases (ESBLs) and AmpC (β-lactamases (AmpC), associated with the blaCMY-2 gene. In Chile, an outbreak by S. Heidelberg occurred in 2011, the phenotypic and genetic characteristics of Chilean strains are unknown. Aim: To determine the antimicrobial susceptibility, presence of plasmids and virulence factor genes in S. Heidelberg strains isolated in Chile over the period 2006-2011. Material and Methods: In sixty-one S. Heidelberg clinical and environmental strains collected by the Public Health Institute in Chile during 2006-2011, antimicrobial susceptibility, plasmids and virulence factor genes (invA, sifA, pefA, agfA, lpfA and, stkD) were studied. Results: S. Heidelberg had a high susceptibility to sulfamethoxazole-trimethoprim, gentamicin, ceftriaxone, ceftiofur, chloramphenicol, amoxicillin-clavulanic acid and ampicillin. However, 52% had decreased susceptibility to ciprofloxacin and 33% resistance to tetracycline. ESBLs were detected in three strains isolated from blood cultures, environment and human feces. The latter strain was positive for AmpC and blaCMY-2 gene. Fifty three of 61 strains showed one to seven plasmids of 0.8 to approximately 30 kb. Most plasmids were small with sizes between 0.8 and 2 kb. All isolates were positive for all genes except pefA. Conclusions: S. Heidelberg isolated from Chilean samples was susceptible to first-line antimicrobials, except tetracycline and ciprofloxacin. The emergence of strains with ESBLs and AmpC should be a warning. The strains were homogeneous for virulence genes, but heterogeneous in their plasmids.


Subject(s)
Humans , Plasmids/isolation & purification , Salmonella/isolation & purification , Salmonella/drug effects , Anti-Bacterial Agents/pharmacology , Reference Values , Salmonella/genetics , Salmonella/pathogenicity , Time Factors , Virulence , DNA, Bacterial , Microbial Sensitivity Tests , Chile , Electrophoresis, Gel, Pulsed-Field , Drug Resistance, Multiple, Bacterial , Environmental Microbiology
6.
Braz. j. microbiol ; 49(2): 248-257, Apr.-June 2018. tab, graf
Article in English | LILACS | ID: biblio-889237

ABSTRACT

Abstract In this study for the first-time microbial communities in the caves located in the mountain range of Hindu Kush were evaluated. The samples were analyzed using culture-independent (16S rRNA gene amplicon sequencing) and culture-dependent methods. The amplicon sequencing results revealed a broad taxonomic diversity, including 21 phyla and 20 candidate phyla. Proteobacteria were dominant in both caves, followed by Bacteroidetes, Actinobacteria, Firmicutes, Verrucomicrobia, Planctomycetes, and the archaeal phylum Euryarchaeota. Representative operational taxonomic units from Koat Maqbari Ghaar and Smasse-Rawo Ghaar were grouped into 235 and 445 different genera, respectively. Comparative analysis of the cultured bacterial isolates revealed distinct bacterial taxonomic profiles in the studied caves dominated by Proteobacteria in Koat Maqbari Ghaar and Firmicutes in Smasse-Rawo Ghaar. Majority of those isolates were associated with the genera Pseudomonas and Bacillus. Thirty strains among the identified isolates from both caves showed antimicrobial activity. Overall, the present study gave insight into the great bacterial taxonomic diversity and antimicrobial potential of the isolates from the previously uncharacterized caves located in the world's highest mountains range in the Indian sub-continent.


Subject(s)
Bacteria/isolation & purification , Bacteria/classification , Environmental Microbiology , Biota , Antibiosis , Pakistan , Phylogeny , Bacteria/growth & development , Bacteria/genetics , DNA, Bacterial/genetics , DNA, Bacterial/chemistry , DNA, Ribosomal/genetics , DNA, Ribosomal/chemistry , RNA, Ribosomal, 16S/genetics , Cluster Analysis , Sequence Analysis, DNA , Euryarchaeota/isolation & purification , Euryarchaeota/classification , Euryarchaeota/growth & development , Euryarchaeota/genetics , DNA, Archaeal/genetics , DNA, Archaeal/chemistry , Metagenomics
7.
Braz. j. microbiol ; 49(2): 207-209, Apr.-June 2018. tab
Article in English | LILACS | ID: biblio-889240

ABSTRACT

Abstract Streptomycetes remain as one of the important sources for bioactive products. Isolated from the mangrove forest, Streptomyces gilvigriseus MUSC 26T was previously characterised as a novel streptomycete. The high quality draft genome of MUSC 26T contained 5,213,277 bp with G + C content of 73.0%. Through genome mining, several gene clusters associated with secondary metabolites production were revealed in the genome of MUSC 26T. These findings call for further investigations into the potential exploitation of the strain for production of pharmaceutically important compounds.


Subject(s)
Streptomyces/genetics , Genome, Bacterial , Environmental Microbiology , Streptomyces/isolation & purification , Base Composition , Biological Products/metabolism , Sequence Analysis, DNA , Computational Biology , Wetlands , Metabolic Networks and Pathways/genetics , Secondary Metabolism
8.
Braz. j. microbiol ; 49(2): 310-319, Apr.-June 2018. tab, graf
Article in English | LILACS | ID: biblio-889225

ABSTRACT

Abstract The aim of this study was evaluated the biofilm formation by Staphylococcus aureus 4E and Salmonella spp. under mono and dual-species biofilms, onto stainless steel 316 (SS) and polypropylene B (PP), and their sensitivity to cetrimonium bromide, peracetic acid and sodium hypochlorite. The biofilms were developed by immersion of the surfaces in TSB by 10 d at 37 °C. The results showed that in monospecies biofilms the type of surface not affected the cellular density (p > 0.05). However, in dual-species biofilms on PP the adhesion of Salmonella spp. was favored, 7.61 ± 0.13 Log10 CFU/cm2, compared with monospecies biofilms onto the same surface, 5.91 ± 0.44 Log10 CFU/cm2 (p < 0.05). The mono and dual-species biofilms were subjected to disinfection treatments; and the most effective disinfectant was peracetic acid (3500 ppm), reducing by more than 5 Log10 CFU/cm2, while the least effective was cetrimonium bromide. In addition, S. aureus 4E and Salmonella spp. were more resistant to the disinfectants in mono than in dual-species biofilms (p < 0.05). Therefore, the interspecies interactions between S. aureus 4E and Salmonella spp. had a negative effect on the antimicrobial resistance of each microorganism, compared with the monospecies biofilms.


Subject(s)
Biofilms/drug effects , Cetrimonium Compounds/pharmacology , Disinfectants/pharmacology , Peracetic Acid/pharmacology , Salmonella/drug effects , Sodium Hypochlorite/pharmacology , Staphylococcus aureus/drug effects , Bacterial Adhesion/drug effects , Biofilms/growth & development , Colony Count, Microbial , Culture Media/chemistry , Environmental Microbiology , Microbial Interactions , Microbial Viability/drug effects , Polypropylenes , Salmonella/growth & development , Stainless Steel , Staphylococcus aureus/growth & development , Temperature , Time
9.
Braz. j. microbiol ; 49(1): 189-199, Jan.-Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-889209

ABSTRACT

ABSTRACT Nine Legionella pneumophila strains isolated from cooling towers and a standard strain (L. pneumophila serogroup 1, ATCC 33152, Philadelphia 1) were analyzed and compared in terms of motility, flagella structure, ability to form biofilms, enzymatic activities (hemolysin, nucleases, protease, phospholipase A, phospholipase C, acid phosphatase, alkaline phosphatase and lipase), hemagglutination capabilities, and pathogenicity in various host cells (Acanthamoeba castellanii ATCC 30234, mouse peritoneal macrophages and human peripheral monocytes). All the isolates of bacteria appeared to be motile and polar-flagellated and possessed the type-IV fimbria. Upon the evaluation of virulence factors, isolate 4 was found to be the most pathogenic strain, while 6 out of the 9 isolates (the isolates 1, 2, 3, 4, 5, and 7) were more virulent than the ATCC 33152 strain. The different bacterial strains exhibited differences in properties such as adhesion, penetration and reproduction in the hosts, and preferred host type. To our knowledge, this is the first study to compare the virulence of environmental L. pneumophila strains isolated in Turkey, and it provides important information relevant for understanding the epidemiology of L. pneumophila.


Subject(s)
Humans , Animals , Female , Mice , Bacterial Proteins/metabolism , Legionella pneumophila/metabolism , Virulence Factors/metabolism , Bacterial Proteins/genetics , Turkey/epidemiology , Legionnaires' Disease/microbiology , Legionella pneumophila/isolation & purification , Legionella pneumophila/genetics , Virulence Factors/genetics , Environmental Microbiology , Macrophages/microbiology , Mice, Inbred BALB C
10.
Mem. Inst. Oswaldo Cruz ; 113(9): e180212, 2018. tab, graf
Article in English | LILACS | ID: biblio-955119

ABSTRACT

Biofilm formation is the preferred mode of growth lifestyle for many microorganisms, including bacterial and fungal human pathogens. Biofilm is a strong and dynamic structure that confers a broad range of advantages to its members, such as adhesion/cohesion capabilities, mechanical properties, nutritional sources, metabolite exchange platform, cellular communication, protection and resistance to drugs (e.g., antimicrobials, antiseptics, and disinfectants), environmental stresses (e.g., dehydration and ultraviolet light), host immune attacks (e.g., antibodies, complement system, antimicrobial peptides, and phagocytes), and shear forces. Microbial biofilms cause problems in the hospital environment, generating high healthcare costs and prolonged patient stay, which can result in further secondary microbial infections and various health complications. Consequently, both public and private investments must be made to ensure better patient management, as well as to find novel therapeutic strategies to circumvent the resistance and resilience profiles arising from biofilm-associated microbial infections. In this work, we present a general overview of microbial biofilm formation and its relevance within the biomedical context.


Subject(s)
Biofilms/growth & development , Bacterial Physiological Phenomena , Fungi/physiology , Environmental Microbiology
11.
Mem. Inst. Oswaldo Cruz ; 113(8): e180098, 2018. tab, graf
Article in English | LILACS | ID: biblio-1040602

ABSTRACT

β-lactamases, which are found in several bacterial species and environments, are the main cause of resistance to β-lactams in Gram-negative bacteria. In 2009, a protein (LRA-13) with two β-lactamase domains (one class C domain and one class D domain) was experimentally characterised, and an extended action spectrum against β-lactams consistent with two functional domains was found. Here, we present the results of searches in the non-redundant NCBI protein database that revealed the existence of a group of homologous bifunctional β-lactamases in the genomes of environmental bacteria. These findings suggest that bifunctional β-lactamases are widespread in nature; these findings also raise concern that bifunctional β-lactamases may be transferred to bacteria of clinical importance through lateral gene transfer mechanisms.


Subject(s)
beta-Lactamases/genetics , Catalytic Domain/genetics , Genomics , Environmental Microbiology , Gram-Negative Bacteria/enzymology , Gram-Negative Bacteria/isolation & purification
12.
Mem. Inst. Oswaldo Cruz ; 112(12): 817-821, Dec. 2017. graf
Article in English | LILACS | ID: biblio-894855

ABSTRACT

BACKGROUND Acanthamoeba is the genus of free-living amoebae that is most frequently isolated in nature. To date, 20 Acanthamoeba genotypes have been described. Genotype T4 is responsible for approximately 90% of encephalitis and keratitis cases. Due to the ubiquitous presence of amoebae, isolation from environmental sources is not uncommon; to determine the clinical importance of an isolation, it is necessary to have evidence of the pathogenic potential of amoebae. OBJECTIVE The aim of this study was to physiologically characterise 8 Acanthamoeba T4 isolates obtained from dental units and emergency combination showers and to determine their pathogenic potential by employing different laboratory techniques. METHODS Eight axenic cultures of Acanthamoeba genotype T4 were used in pathogenic potential assays. Osmotolerance, thermotolerance, determination and characterisation of extracellular proteases and evaluation of cytopathic effects in MDCK cells were performed. FINDINGS All of the isolates were osmotolerant, thermotolerant and had serine proteases from 44-122 kDa. Two isolates had cytopathic effects on the MDCK cell monolayer. MAIN CONCLUSION The presence of Acanthamoeba T4 with pathogenic potential in areas such as those tested in this study reaffirms the need for adequate cleaning and maintenance protocols to reduce the possibility of infection with free-living amoebae.


Subject(s)
Humans , Acanthamoeba/isolation & purification , Acanthamoeba/genetics , Acanthamoeba/pathogenicity , Environmental Microbiology , Phylogeny , Genotype
13.
Braz. j. microbiol ; 48(3): 499-508, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-889148

ABSTRACT

Abstract Salmonella is recognized as a common foodborne pathogen, causing major health problems in Saudi Arabia. Herein, we report epidemiology, antimicrobial susceptibility and the genetic basis of resistance among S. enterica strains isolated in Saudi Arabia. Isolation of Salmonella spp. from clinical and environmental samples resulted in isolation of 33 strains identified as S. enterica based on their biochemical characteristics and 16S-rDNA sequences. S. enterica serovar Enteritidis showed highest prevalence (39.4%), followed by S. Paratyphi (21.2%), S. Typhimurium (15.2%), S. Typhi and S. Arizona (12.1%), respectively. Most isolates were resistant to 1st and 2nd generation cephalosporin; and aminoglycosides. Moreover, several S. enterica isolates exhibited resistance to the first-line antibiotics used for Salmonellosis treatment including ampicillin, trimethoprim-sulfamethoxazole and chloramphenicol. In addition, the results revealed the emergence of two S. enterica isolates showing resistance to third-generation cephalosporin. Analysis of resistance determinants in S. enterica strains (n = 33) revealed that the resistance to β-lactam antibiotics, trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline, was attributed to the presence of carb-like, dfrA1, floR, tetA gene, respectively. On the other hand, fluoroquinolone resistance was related to the presence of mutations in gyrA and parC genes. These findings improve the information about foodborne Salmonella in Saudi Arabia, alarming the emergence of multi-drug resistant S. enterica strains, and provide useful data about the resistance mechanisms.


Subject(s)
Humans , Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Salmonella enterica/drug effects , Salmonella enterica/isolation & purification , Salmonella Infections/microbiology , Environmental Microbiology , Integrons , Microbial Sensitivity Tests , Salmonella enterica/classification , Salmonella enterica/genetics , Saudi Arabia , Serotyping , Tetracycline/pharmacology
14.
Braz. j. microbiol ; 48(3): 451-460, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-889134

ABSTRACT

Abstract This study was focused on the polyhydroxybutyrate (PHB) accumulation property of Bacillus aryabhattai isolated from environment. Twenty-four polyhydroxyalkanoate (PHA) producers were screened out from sixty-two environmental bacterial isolates based on Sudan Black B colony staining. Based on their PHA accumulation property, six promising isolates were further screened out. The most productive isolate PHB10 was identified as B. aryabhattai PHB10. The polymer production maxima were 3.264 g/L, 2.181 g/L, 1.47 g/L, 1.742 g/L and 1.786 g/L in glucose, fructose, maltose, starch and glycerol respectively. The bacterial culture reached its stationary and declining phases at 18 h and 21 h respectively and indicated growth-associated PHB production. Nuclear Magnetic Resonance (NMR) spectra confirmed the material as PHB. The material has thermal stability between 30 and 140 °C, melting point at 170 °C and maximum thermal degradation at 287 °C. The molecular weight and poly dispersion index of the polymer were found as 199.7 kDa and 2.67 respectively. The bacterium B. aryabhattai accumulating PHB up to 75% of cell dry mass utilizing various carbon sources is a potential candidate for large scale production of bacterial polyhydroxybutyrate.


Subject(s)
Bacillus/metabolism , Polyhydroxyalkanoates/biosynthesis , Starch/metabolism , Bacillus/isolation & purification , Bacillus/growth & development , Bacillus/genetics , Culture Media/metabolism , Culture Media/chemistry , Environmental Microbiology , Polyhydroxyalkanoates/chemistry , Glycerol/metabolism
15.
Rev. Soc. Bras. Med. Trop ; 50(2): 167-172, Mar.-Apr. 2017. tab
Article in English | LILACS | ID: biblio-842841

ABSTRACT

Abstract INTRODUCTION: Acinetobacter baumannii is a major pathogen causing infections in intensive care units (ICUs). In this study, we aimed to evaluate the presence of A. baumannii in an ICU environment and gloves from ICU workers and to characterize the antimicrobial resistance of the isolates in comparison with those isolated from ICU patients at the same hospital. METHODS: ICU samples were collected from March to November 2010. Isolates biochemically characterized as Acinetobacter calcoaceticus-Acinetobacter baumannii complex were evaluated by PCR targeting the 16S rDNA and bla OXA-51 genes. Antimicrobial susceptibility was determined using the disk diffusion method, and carbapenem-resistant isolates were also evaluated for the minimum inhibitory concentration of imipenem using broth microdilution. The presence of the bla OXA-23 gene was evaluated in isolates with reduced susceptibility to carbapenems. RESULTS: A. baumannii was detected in 9.5% (84) of the 886 samples collected from the ICU environment, including from furniture, medical devices, and gloves, with bed rails being the most contaminated location (23.8%; 20/84). Multidrug-resistant (MDR) A. baumannii was found in 98.8% (83/84) of non-clinical and 97.8% (45/46) of clinical isolates. Reduced susceptibility to carbapenems was detected in 83.3% (70/84) of non-clinical and 80.4% (37/46) of clinical isolates. All isolates resistant to carbapenems harbored bla OXA-23. CONCLUSIONS: We found a strong similarity between the antimicrobial susceptibility profiles of non-clinical and clinical A. baumannii isolates. Such data highlight the ICU environment as a potential origin for the persistence of MDR A. baumannii, and hence the ICU may be a source of hospital-acquired infections caused by this microorganism.


Subject(s)
Humans , Carbapenems/pharmacology , Polymerase Chain Reaction , Gloves, Protective/microbiology , Acinetobacter baumannii/drug effects , Environmental Microbiology , Equipment and Supplies, Hospital/microbiology , Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial , Acinetobacter baumannii/isolation & purification , Acinetobacter baumannii/enzymology , Disk Diffusion Antimicrobial Tests
16.
Braz. j. microbiol ; 48(1): 37-42, Jan.-Mar. 2017. tab, graf
Article in English | LILACS | ID: biblio-839338

ABSTRACT

Abstract Quantification of bacteria being grazed by microzooplankton is gaining importance since they serve as energy subsidies for higher trophic levels which consequently influence fish production. Hence, grazing pressure on viable and non-viable fraction of free and particle-associated bacteria in a tropical estuary controlled mainly by protist grazers was estimated using the seawater dilution technique. In vitro incubations over a period of 42 h showed that at the end of 24 h, growth coefficient (k) of particle-associated bacteria was 9 times higher at 0.546 than that of free forms. Further, ‘k’ value of viable cells on particles was double that of free forms at 0.016 and 0.007, respectively. While bacteria associated with particles were grazed (coefficient of removal (g) = 0.564), the free forms were relatively less grazed indicating that particle-associated bacteria were exposed to grazers in these waters. Among the viable and non-viable forms, ‘g’ of non-viable fraction (particle-associated bacteria = 0.615, Free = 0.0086) was much greater than the viable fraction (particle-associated bacteria = 0.056, Free = 0.068). Thus, grazing on viable cells was relatively low in both the free and attached states. These observations suggest that non-viable forms of particle-associated bacteria were more prone to grazing and were weeded out leaving the viable cells to replenish the bacterial standing stock. Particle colonization could thus be a temporary refuge for the “persistent variants” where the viable fraction multiply and release their progeny.


Subject(s)
Bacteria , Ecosystem , Environmental Microbiology , Eukaryota , Seawater/microbiology , Water Microbiology , Biodiversity
17.
Braz. j. microbiol ; 48(1): 79-86, Jan.-Mar. 2017. tab, graf
Article in English | LILACS | ID: biblio-839358

ABSTRACT

Abstract Mucorales comprises fungi commonly isolated as saprobes from soil, dung, stored grains and plants. Although these fungi have been studied in several countries, there are relatively a few reports of them in semi-arid areas. Therefore, the aims of the present study were to assess and compare the Mucorales communities in dung from different species and breeds of herbivores in the semi-arid of Pernambuco, based on the frequency of occurrence and species richness of these fungi. Samples of dung collected in the cities of Arcoverde, Serra Talhada and Sertânia were incubated in moist chambers in triplicate. Altogether, 24 taxa of Mucorales distributed in the genera Absidia, Circinella, Cunninghamella, Lichtheimia, Mucor, Pilobolus, Rhizopus and Syncephalastrum were identified. The highest species richness was found in sheep excrement. Mucor circinelloides f. griseo-cyanus was the most common taxon, followed by M. ramosissimus. The similarity of the composition of Mucorales species was greatest between the excrements of Guzerá and Sindi breeds (bovine). All mucoralean species isolated are being cited for the first time from animal dung found in Caatinga and a new species of Mucor was recorded. An identification key for species of Mucorales from dung in the semi-arid region of Brazil is provided.


Subject(s)
Animals , Environmental Microbiology , Mucorales , Brazil , Cattle , Sheep , Cluster Analysis , Biodiversity , Herbivory , Mucorales/classification
18.
Braz. j. microbiol ; 48(1): 71-78, Jan.-Mar. 2017. tab, graf
Article in English | LILACS | ID: biblio-839359

ABSTRACT

Abstract In this study, determination of heavy metal parameters and microbiological characterization of marine sediments obtained from two heavily polluted sites and one low-grade contaminated reference station at Jiaozhou Bay in China were carried out. The microbial communities found in the sampled marine sediments were studied using PCR-DGGE (denaturing gradient gel electrophoresis) fingerprinting profiles in combination with multivariate analysis. Clustering analysis of DGGE and matrix of heavy metals displayed similar occurrence patterns. On this basis, 17 samples were classified into two clusters depending on the presence or absence of the high level contamination. Moreover, the cluster of highly contaminated samples was further classified into two sub-groups based on the stations of their origin. These results showed that the composition of the bacterial community is strongly influenced by heavy metal variables present in the sediments found in the Jiaozhou Bay. This study also suggested that metagenomic techniques such as PCR-DGGE fingerprinting in combination with multivariate analysis is an efficient method to examine the effect of metal contamination on the bacterial community structure.


Subject(s)
Bacteria , Geologic Sediments/microbiology , Geologic Sediments/chemistry , Metals, Heavy , Biodiversity , Environmental Microbiology , Environmental Pollutants , Environmental Pollution , Bacteria/classification , Cluster Analysis , China , Bays , Environment
19.
Clin. biomed. res ; 37(1): 38-40, 2017. ilus, graf
Article in English | LILACS | ID: biblio-833301

ABSTRACT

We report the result of an awareness campaign about the importance of hand hygiene after using different devices used in assistance to patients, such as tablets, notebooks, mobile phones, identification cards, watches, cameras, showing the level of contamination found after detection of adenosine triphosphate (ATP) via bioluminescence, which enables a quantitative assessment ready and easy to implement. ATP molecules found in all living cells react with the enzyme complex to generate light and represent the presence of organic matter in such objects(AU)


Subject(s)
Humans , Adenosine Triphosphate/analysis , Bacterial Infections/transmission , Cell Phone , Cross Infection/transmission , Bacterial Infections/prevention & control , Environmental Microbiology , Hand/microbiology , Health Personnel , Luminescent Measurements/methods
20.
Braz. j. microbiol ; 47(4): 846-852, Oct.-Dec. 2016. tab, graf
Article in English | LILACS | ID: biblio-828191

ABSTRACT

Abstract Copper mine drainages are restricted environments that have been overlooked as sources of new biocatalysts for bioremediation and organic syntheses. Therefore, this study aimed to determine the enzymatic activities (esterase, epoxide hydrolase and monooxygenase) of 56 heterotrophic bacteria isolated from a neutral copper mine drainage (Sossego Mine, Canaã dos Carajás, Brazil). Hydrolase and monooxygenase activities were detected in 75% and 20% of the evaluated bacteria, respectively. Bacterial strains with good oxidative performance were also evaluated for biotransformation of organic sulfides. Fourteen strains with good enzymatic activity were identified by 16S rRNA gene sequencing, revealing the presence of three genera: Bacillus, Pseudomonas and Stenotrophomonas. The bacterial strains B. megaterium (SO5-4 and SO6-2) and Pseudomonas sp. (SO5-9) efficiently oxidized three different organic sulfides to their corresponding sulfoxides. In conclusion, this study revealed that neutral copper mine drainages are a promising source of biocatalysts for ester hydrolysis and sulfide oxidation/bioremediation. Furthermore, this is a novel biotechnological overview of the heterotrophic bacteria from a copper mine drainage, and this report may support further microbiological monitoring of this type of mine environment.


Subject(s)
Bacteria/classification , Bacteria/enzymology , Copper , Environmental Microbiology , Oxidation-Reduction , Phylogeny , Sulfides/metabolism , Bacteria/isolation & purification , Bacteria/genetics , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Enzymes , Esterases/genetics , Esterases/metabolism , Mixed Function Oxygenases/genetics , Mixed Function Oxygenases/metabolism , Mining
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