Assessment of zinc solubilization potential of zinc-resistant Pseudomonas oleovorans strain ZSB13 isolated from contaminated soil / Avaliação do potencial de solubilização do zinco da cepa ZSB13 de Pseudomonas oleovorans resistente ao zinco isolada de solo contaminado

Zinc is an essential micronutrient that is required for optimum plant growth. It is present in soil in insoluble forms. Bacterial solubilization of soil unavailable form of Zn into available form, is an emerging approach to alleviate the Zn deficiency for plants and human beings. Zinc solubilizing bacteria (ZSB) could be a substitute for chemical Zn fertilizer. The present study aimed to isolate and characterize bacterial species from the contaminated soil and evaluate their Zn solubilizing potential. Zn resistant bacteria were isolated and evaluated for their MIC against Zn. Among the 13 isolated bacterial strains ZSB13 showed maximum MIC value upto 30mM/L. The bacterial strain with the highest resistance against Zn was selected for further analysis. Molecular characterization of ZSB13 was performed by 16S rRNA gene amplification which confirmed it as Pseudomonas oleovorans. Zn solubilization was determined through plate assay and broth medium. Four insoluble salts (zinc oxide (ZnO), zinc carbonate (ZnCO3), zinc sulphite (ZnS) and zinc phosphate (Zn3(PO4)2) were used for solubilization assay. Our results shows 11 mm clear halo zone on agar plates amended with ZnO. Likewise, ZSB13 showed significant release of Zn in broth amended with ZnCO3 (17 and 16.8 ppm) and ZnO (18.2 ppm). Furthermore, Zn resistance genes czcD was also enriched in ZSB13. In our study, bacterial strain comprising Zn solubilization potential has been isolated that could be further used for the growth enhancement of crops.

O zinco é um micronutriente essencial necessário para o crescimento ideal das plantas. Ele está presente no solo em formas insolúveis. A solubilização bacteriana da forma indisponível de Zn no solo para a forma disponível é uma abordagem emergente para aliviar a deficiência de Zn em plantas e seres humanos. Bactérias solubilizadoras de zinco (ZSB) podem ser um substituto para fertilizantes químicos de Zn. O presente estudo teve como objetivo isolar e caracterizar espécies bacterianas de solo contaminado e avaliar seu potencial de solubilização de Zn. Bactérias resistentes ao Zn foram isoladas e avaliadas quanto ao seu MIC contra o Zn. Entre as 13 cepas bacterianas isoladas, ZSB13 apresentou valor máximo de MIC de até 30 mM/L. A cepa bacteriana com maior resistência ao Zn foi selecionada para análise posterior. A caracterização molecular de ZSB13 foi realizada por amplificação do gene 16S rRNA que o confirmou como Pseudomonas oleovorans. A solubilização do Zn foi determinada através de ensaio em placa e meio caldo. Quatro sais insolúveis (óxido de zinco (ZnO), carbonato de zinco (ZnCO3), sulfito de zinco (ZnS) e fosfato de zinco (Zn3 (PO4) 2) foram usados para o ensaio de solubilização. Nossos resultados mostram uma zona de halo clara de 11 mm em placas de ágar corrigidas com ZnO. Da mesma forma, ZSB13 mostrou liberação significativa de Zn em caldo alterado com ZnCO3 (17 e 16,8 ppm) e ZnO (18,2 ppm). Além disso, os genes de resistência ao Zn czcD também foram enriquecidos em ZSB13. Em nosso estudo, a cepa bacteriana compreendendo potencial de solubilização de Zn foi isolada e poderia ser usada posteriormente para o aumento do crescimento de safras.

Biodegradation of petroleum by bacteria isolated from fishes of Indian Ocean / Biodegradação do petróleo por bactérias isoladas de peixes do oceano Índico

In this study, oil degrading bacteria discovered from fish living near the oil ports at Karachi in Pakistan were characterized. The bacteria isolated from skin, gills, and gut in fish could consume crude oil as a source of carbon and energy. Total 36 isolates were tested using Nutrient Agar (NA) and MSA media with different crude oil concentrations (0.2%, 0.5%, 0.7%, 1%, 2%, and 5%) and 4 out of 36 isolates (two Gram positive and two Gram negative bacteria) were selected for further identification. 16S rRNA gene sequencing revealed that the isolates are related to Bacillus velezensis, Bacillus flexus, Pseudomonas brenneri and Pseudomonas azotoforman. Oil degrading potential of these bacteria was characterized by GC-MS analysis of degradation of oil components in crude oil as well as engine oil. We found that one (2, 6, 10, 14-Tetramethylpentadecane) out of 42 components in the crude oil was fully eliminated and the other oil components were reduced. In addition, 26 out of 42 oil components in the engine oil, were fully eliminated and the rest were amended. Taken together, these studies identify that B. velezensis, B. flexus, P. brenneri and P. azotoforman have high oil degrading potential, which may be useful for degradation of oil pollutants and other commercial applications.

Neste estudo, bactérias degradadoras de óleo descobertas em peixes que vivem perto dos portos de petróleo em Karachi, no Paquistão, foram caracterizadas. As bactérias isoladas da pele, guelras e intestinos dos peixes podem consumir petróleo bruto como fonte de carbono e energia. No total, 36 isolados foram testados usando Agar Nutriente (NA) e meio MSA com diferentes concentrações de óleo bruto (0,2%, 0,5%, 0,7%, 1%, 2% e 5%) e 4 de 36 isolados (dois Gram positivos e duas bactérias Gram negativas) foram selecionadas para posterior identificação. O sequenciamento do gene 16S rRNA revelou que os isolados estão relacionados a Bacillus velezensis, Bacillus flexus, Pseudomonas brenneri e Pseudomonas azotoforman. O potencial de degradação do óleo dessas bactérias foi caracterizado pela análise de GC-MS da degradação dos componentes do óleo no óleo cru, bem como no óleo do motor. Descobrimos que um (2, 6, 10, 14-tetrametilpentadecano) de 42 componentes do óleo cru foi totalmente eliminado e os outros componentes do óleo foram reduzidos. Além disso, 26 dos 42 componentes do óleo do motor foram totalmente eliminados e o restante corrigido. Juntos, esses estudos identificam que B. velezensis, B. flexus, P. brenneri e P. azotoforman têm alto potencial de degradação de óleo, o que pode ser útil para a degradação de poluentes de óleo e outras aplicações comerciais.

Pseudomonas spp. and other psychrotrophic microorganisms in inspected and non-inspected Brazilian Minas Frescal cheese: proteolytic, lipolytic and AprX production potential / Pseudomonas spp. e outros micro-organismos psicrotróficos em queijos Minas Frescal inspecionados e não inspecionados: potencial proteolítico, lipolítico e produção de AprX

The most consumed cheese in Brazil, Minas Frescal cheese (MFC) is highly susceptible to microbial contamination and clandestine production and commercialization can pose a risk to consumer health. The storage of this fresh product under refrigeration, although more appropriate, may favor the growth of spoilage psychrotrophic bacteria. The objective of this study was to quantify and compare Pseudomonas spp. and other psychrotrophic bacteria in inspected and non-inspected MFC samples, evaluate their lipolytic and proteolytic activities and their metalloprotease production potentials. Twenty MFC samples were evaluated: 10 inspected and 10 non-inspected. Counts of psychrotrophic bacteria and Pseudomonas spp., evaluation of the proteolytic and lipolytic potential of the isolates, and identification of potential producers of alkaline metalloprotease (AprX) were assessed. The mean total psychrotrophic counts were 1.07 (±2.18) × 109CFU/g in the inspected samples and 4.5 (±5.86) × 108CFU/g in the non-inspected, with no significant difference (p=0.37). The average score of Pseudomonas spp. was 6.86 (±18.6) × 105 and 2.08 (±3.65) × 106 CFU/g for the inspected and non-inspected MFC samples, respectively, with no significant difference (p=0.1). Pseudomonas spp. represented 0.06% and 0.004% of psychrotrophic bacteria found in inspected and non-inspected MFC samples, respectively. Collectively, 694 psychrotrophic strains and 47Pseudomonas spp. were isolated, of which 59.9% and 68.1% were simultaneously proteolytic and lipolytic, respectively. Of the 470 psychrotrophs isolated from inspected and 224 from non-inspected cheese samples, 5.74% and 2.23% contained aprX, respectively, while 100 and 86.96% of the Pseudomonas spp. isolates in inspected and non-inspected cheese samples contained the gene. The production potential of AprX did not, however, determine the proteolytic activity on plates of these isolates under the conditions evaluated in this study. Of total, 65.63% of the psychrotrophs that contained aprX gene were confirmed as Pseudomonas spp., using genus-specific PCR. Phylogenetic analysis of the 16S rRNA gene of the other psychrotrophs that were potential producers of AprX identified them as Serratia spp. (n=7), Raoultella ornithinolytica (n=1), and Acinetobacter schindleri (n=1) in the inspected samples and Psychrobacter sanguinis (n=1) and Leuconostoc mesenteroides (n=1) in the non-inspected samples. The production conditions of Brazilian MFC of these samples, while meeting the legal determinations, are not sufficient to control Pseudomonas and other spoilage-related psychrotrophs. Thus, stricter hygienic measures are required during the formal production of this type of cheese.(AU)

O mais consumido no Brasil, o queijo Minas Frescal (QMF) é altamente suscetível à contaminação microbiana e a produção e comercialização clandestina podem representar um risco para a saúde do consumidor. O armazenamento deste produto fresco sob refrigeração, embora mais apropriado, pode favorecer a multiplicação de bactérias psicrotróficas deteriorantes. O objetivo deste estudo foi quantificar e comparar Pseudomonas spp. e outras bactérias psicrotróficas em amostras de QMF inspecionadas e não inspecionadas, avaliar o potencial lipolítico, proteolítico e de produção de metaloprotease alcalina. Vinte amostras de QMF foram avaliadas: 10 inspecionadas e 10 não inspecionadas. Foram avaliadas as contagens de bactérias psicrotróficas e Pseudomonas spp., o potencial proteolítico e lipolítico dos isolados e a identificação de potenciais produtores de metaloprotease alcalina (AprX). A média total das contagens de bactérias psicrotróficas foi de 1,07 (±2,18) × 109UFC/g nas amostras inspecionadas e 4,5 (±5,86) × 108UFC/g nas não inspecionadas, sem diferença significativa (p=0,37). A média de Pseudomonasspp. foi de 6,86 (±18,6) × 105 e 2,08 (±3,65) × 106UFC/g para as amostras QMF inspecionadas e não-inspecionadas, respectivamente, sem diferença significativa (p=0,1). Pseudomonas spp. representaram 0,06% e 0,004% de bactérias psicrotróficas encontradas em amostras QMF inspecionadas e não-inspecionadas, respectivamente. Das amostras inspecionadas e não inspecionadas, foram isoladas 694 colônias psicrotróficas e 47 Pseudomonasspp., dos quais 59,9% e 68,1% foram simultaneamente proteolíticos e lipolíticos, respectivamente. Dos 470 isolados de psicrotróficos das amostras de queijo inspecionados e dos 224 isolados das não inspecionadas, 5,74% e 2,23% continham o gene aprX, respectivamente, enquanto 100 e 86,96% das Pseudomonasspp. isoladas em amostras de queijo inspecionadas e não inspecionadas continham o potencial de expressão de AprX. Esse potencial, no entanto, não determinou a atividade proteolítica em placas desses isolados nas condições avaliadas neste estudo. Do total, 65,63% dos psicrotróficos que continham o gene aprX foram confirmados como Pseudomonasspp., utilizando PCR gênero-específico. A análise filogenética do gene 16S rRNA dos outros psicrotróficos que foram produtores potenciais de AprX os identificou como Serratia spp. (n=7), Raoultella ornithinolytica (n=1) e Acinetobacter schindleri (n=1) nas amostras inspecionadas e Psychrobacter sanguinis (n=1) e Leuconostoc mesenteroides (n=1) nas amostras não inspecionadas. As condições de produção do QMF dessas amostras, atendendo às determinações legais, não são suficientes para controlar a Pseudomonas e outros psicrotróficos relacionados à deterioração. Assim, medidas higiênicas mais rígidas são necessárias durante a produção formal deste tipo de queijo.(AU)

Diagnóstico e propostas de ações visando a melhoria da qualidade microbiológica do leite cru recebido em um laticínio localizado no Sul de Minas Gerais / Diagnosis and proposed actions aiming the improvement of the microbiological quality of raw milk received in a dairy located in the South of Minas Gerais

O objetivo deste estudo foi verificar a qualidade microbiológica do leite cru refrigerado recebido no Laticínio de uma Cooperativa localizada no Sul do Estado de Minas Gerais e propor ações corretivas. Amostras de leite foram coletadas dos compartimentos dos tanques de caminhões em três dias diferentes, plaqueadas em duplicata em Ágar Padrão para Contagem e incubadas a 7ºC por 10 dias. Foram identificadas 92 espécies através de espectrofotometria de massas MALDI-TOF-MS. Entre os isolados identificados o gênero Pseudomonas foi predominante, sendo conhecido por possuir grande capacidade de produção de enzimas degradativas em leite cru refrigerado. Foi possível verificar que somente o resfriamento do leite não garante a sua qualidade microbiológica, sendo necessárias outras ações visando à redução da contaminação microbiológica inicial do leite cru.

Modelagem da formação de biofilmes de Pseudomonas fluorescens e Pseudomonas aeruginosa em aço inoxidável através da metodologia de superfície de resposta / Modeling Pseudomonas luorescens and Pseudomonas aeruginosa biofilm formation on stainless steel by response surface methodology

O objetivo deste trabalho foi verificar a influência do tempo e da temperatura na formação de biofilmes de P. fluorescens e P. aeruginosa em superfície de aço inoxidável através de um delineamento composto central rotacional (DCCR). Os biofilmes foram avaliados nas temperaturas de 7; 13; 27; 41 e 47 °C e nos tempos de contato de 0; 1,2; 4; 6,8 e 8 dias. As superfícies de resposta mostraram que P. fluorescens foi capaz de formar biofilme entre 0,9 e 8 dias em temperaturas entre 9,8 e 47 °C. P. aeruginosa foi capaz de formar biofilme entre0,7 a 8 dias e entre 11 e 47 °C. É importante destacar que estas condições são frequentemente encontradas durante todo o processamento de queijo Minas frescal, comprometendo a segurança do alimento.

Phylogenetic MLSA and phenotypic analysis identification of three probable novel Pseudomonas species isolated on King George Island, South Shetland, Antarctica

ABSTRACT Antarctica harbors a great diversity of microorganisms, including bacteria, archaea, microalgae and yeasts. The Pseudomonas genus is one of the most diverse and successful bacterial groups described to date, but only eight species isolated from Antarctica have been characterized. Here, we present three potentially novel species isolated on King George Island. The most abundant isolates from four different environments, were genotypically and phenotypically characterized. Multilocus sequence analysis and 16S rRNA gene analysis of a sequence concatenate for six genes (16S, aroE, glnS, gyrB, ileS and rpoD), determined one of the isolates to be a new Pseudomonas mandelii strain, while the other three are good candidates for new Pseudomonas species. Additionally, genotype analyses showed the three candidates to be part of a new subgroup within the Pseudomonas fluorescens complex, together with the Antarctic species Pseudomonas antarctica and Pseudomonas extremaustralis. We propose terming this new subgroup P. antarctica. Likewise, phenotypic analyses using API 20 NE and BIOLOG® corroborated the genotyping results, confirming that all presented isolates form part of the P. fluorescens complex. Pseudomonas genus research on the Antarctic continent is in its infancy. To understand these microorganisms' role in this extreme environment, the characterization and description of new species is vital.

Control potential of Meloidogyne javanica and Ditylenchus spp. using fluorescent Pseudomonas and Bacillus spp

ABSTRACT Plant Growth Promoting Rhizobacteria (PGPR) have different mechanisms of action in the development of plants, such as growth promotion, production of phytohormones and antibiotic substances and changes in root exudates. These help to control plant diseases. In order to evaluate the potential of microorganisms in the control of Meloidogyne javanica and Ditylenchus spp., five rhizobacteria isolated from rhizosphere of garlic cultivated in the Curitibanos (SC) region were tested. Hatching chambers were set on Petri dishes, in which were added 10 mL of bacterial suspension and 1 mL of M. javanica eggs suspension, at the rate of 4500, on the filter paper of each chamber. The same procedure was performed with 300 juvenile Ditylenchus spp. The experimental design was completely randomized, with four replications. The evaluations were performed every 72 h for nine days. The antagonized population of nematodes was determined in Peters counting chamber, determining the percentage hatching (for M. javanica) and motility (for Ditylenchus spp). Isolates CBSAL02 and CBSAL05 significantly reduced the hatching of M. javanica eggs (74% and 54.77%, respectively) and the motility of Ditylenchus spp. (55.19% and 53.53%, respectively) in vitro. Isolates were identified as belonging to the genera Pseudomonas (CBSAL05) and Bacillus (CBSAL02).

Influência da cloração da água utilizada na higienização de tanques de expansão na qualidade do leite cru refrigerado / Influence of the chlorination of the water used in the hygiene of expansion tanks in the quality of refrigerated raw milk

[{"text": "Este trabalho objetivou avaliar a\r\ninfluência da cloração da água utilizada\r\nna higienização de tanques de\r\nexpansão na contagem de Escherichia\r\ncoli e Pseudomonas sp. do leite\r\ncru refrigerado. Amostras de leite cru\r\ne de água de18 tanques de expansão\r\nforam avaliadas por um ano, sendo\r\nque em 9 tanques não havia sistema\r\nde cloração da água implantado no\r\ndecorrer de 12 meses e nos outros\r\n9, por 6 meses não houve cloração\r\nda água e nos 6 meses seguintes o\r\nsistema foi implantado. Para determinação\r\nde E. coli no leite cru e na\r\nágua utilizou-se a técnica do Número\r\nMais Provável (NMP) e para\r\na contagem de Pseudomonas sp.\r\nutilizou-se Ágar Para Isolamento de\r\nPseudomonas (PIA). Constataram-\r\n-se valores médios de 1,5NMP/mL e\r\n1,6NMP/mLde E. coli no leite e na\r\nágua, respectivamente, nas amostras\r\nprovenientes dos 9 tanques em que a\r\nágua utilizada não foiclorada por 12\r\nmeses. As amostras de leite e água\r\nprocedentes dos 9 tanques que receberam\r\nágua clorada durante a limpeza\r\npor 6 meses apresentaram em média\r\n1,8NMP/mL e < 1,1 NMP/mL de\r\nE.coli, respectivamente. A contagem\r\nmédia de Pseudomonas sp. nas amostras\r\nde água procedentes dos 9 tanques\r\nem que a água utilizada no processo\r\nde limpeza não recebeu cloração por\r\n6 meses e que posteriormente passou\r\na ser clorada foi 1,1x103UFC/mL e\r\n1,2x102UFC/mL, respectivamente.\r\nPor outro lado,amédia das contagens\r\nde Pseudomonas sp. foi de 9,8x104\r\nUFC/mL e 5,1x105 UFC/mL nas\r\namostras de leite procedentes dos tanques\r\nem que a água utilizada no processo\r\nde limpeza não recebeu cloração\r\npor 6 meses e que posteriormente\r\npassou a ser clorada, respectivamente,\r\no que indica que esta bactéria acessa o\r\nleite cru a partir de diferentes fontes\r\nde contaminação, além da água. Assim,\r\na cloração foi eficiente apenas\r\nna redução da contagem de E. coli e\r\nPseudomonas sp. na água.(AU)", "_i": "pt"}]

Reutilização do detergente enzimático: avaliação do impacto da contaminação microbiana da solução na efetividade da limpeza de aparelhos endoscópicos gastrointestinais / Enzymatic detergent reuse: evaluation of the impact of the solution's microbial contamination on the cleaning effectiveness of gastrointestinal endoscopes

No Brasil, é recomendado que durante a limpeza dos Produtos para Saúde (PPS) o detergente utilizado possua ação enzimática. Embora a Resolução da Diretoria Colegiada nº 55 de 14 de novembro de 2012 da Agência Nacional de Vigilância Sanitária desaconselhe a reutilização desta solução de limpeza, sabe-se que na prática clínica elas são reaproveitadas por diversas vezes para imersão de PPS, como os aparelhos endoscópicos, o que pode comprometer a efetividade da ação do detergente enzimático e com isso a segurança no processamento do PPS. Esta pesquisa objetivou avaliar a carga microbiana presente na solução de detergente enzimático durante sua reutilização na limpeza manual de aparelhos endoscópicos gastrointestinais. Tratou-se de um estudo transversal realizado em um serviço de endoscopia digestiva de um hospital universitário de Belo Horizonte e no Laboratório de Microbiologia Oral e Anaeróbios do ICB/UFMG. A amostra foi composta por 57 aparelhos endoscópicos e 76 alíquotas de solução de detergente enzimáticos coletadas de diversos reusos de 19 diferentes soluções. O material coletado foi agitado em vórtex, acrescido a Caldo Letheem Modificado e submetido a filtração em membrana Millipore® 0,45µm. A membrana foi depositada em Tryptic Soy Ágar para crescimento microbiano. A identificação presuntiva dos micro-organismos foi realizada manualmente considerando-se aspectos morfotintoriais e reações bioquímico/fisiológicas. As variáveis foram descritas utilizando frequências, porcentagens e medidas de tendência central. O projeto foi aprovado pelo Comitê de Ética e Pesquisa da Universidade Federal de Minas Gerais (CAAE ­ 67493417.1.0000.5149). As médias das cargas microbianas na solução de detergente enzimático variaram de 19,9 UFC/mL após primeiro uso, 51,1 UFC/mL após terceiro uso e 67,1UFC/mL após o quinto reuso. Nos canais de ar/água e biópsia houve aumento de micro-organismos Gram negativos ao longo das reutilizações do detergente. Foram recuperados, Enterobacter spp., Escherichia coli, Klebsiella spp., Pseudomonas spp., Staphyloccocus aureus, Staphyloccocus coagulase negativa. Pseudomonas spp. foi o micro-organismo mais identificado em todas as alíquotas coletadas. Verificou-se a importância da escovação do canal de biópsia para correta remoção de micro-organismos. Conclui-se que a reutilização das soluções de detergente enzimático contribuiu para contaminação dos aparelhos endoscópicos com micro-organismos potencialmente patogênicos. Faz-se necessário a reavaliação de protocolos institucionais, no sentido de que seja cumprida a orientação da Anvisa por meio da RDC nº 55 de 14 de novembro de 2012 de que os detergentes enzimáticos não devem ser reutilizados sob perda da eficiência do produto. As características físico químicas dos detergentes enzimáticos devem ser respeitadas pelos serviços de saúde conforme parâmetros estabelecidos pelos fabricantes.(AU)

In Brazil, it is recommended that during the cleaning of Health Products the detergent used has enzymatic action. Although Collegiate Board Resolution No. 55 of November 14, 2012 of the National Agency of Sanitary Surveillance advises against the reuse of this cleaning solution, it is known that in clinical practice they are reused several times for immersion of health products, such a gastrointestinal endoscope, which may compromise the effectiveness of the enzymatic detergent action and thus the safety in the processing. This research aimed to evaluate the microbial load present in the enzymatic detergent solution during its reuse in the manual cleaning of endoscopic gastrointestinal devices. This was a cross-sectional study performed at a gastrointestinal endoscopy service at a university hospital in Belo Horizonte and at the Oral Microbiology and Anaerobic Laboratory of ICB/UFMG. The sample consisted of 57 endoscopes and 76 aliquots of enzymatic detergent solution collected from several replicates of 19 different solutions. The collected material was vortexed, added to Modified Letheem Broth and subjected to Millipore® 0.45 µm membrane filtration. The membrane was deposited in Tryptic Soy Ágar for microbial growth. The identification of the microorganisms was performed manually considering morphotintorial aspects and biochemical/physiological reactions. The variables were described using frequencies, percentages and measures of central tendency. The project was approved by the Ethics and Research Committee of the Federal University of Minas Gerais (CAAE - 67493417.1.0000.5149). The mean values of the microbial loads in the enzymatic detergent solution varied from 19.9 UFC/mL after first use, 51.1 UFC/mL after third use and 67.1 UFC/mL after the fifth reuse. In the air/water and biopsy channels there was an increase of Gram negative microorganisms along the reuse of the detergent. Enterobacter spp., Escherichia coli, Klebsiella spp., Pseudomonas spp., Staphylococcus aureus, Coagulase-negative Staphyloccocus were recovered. Pseudomonas spp. was the most identified microorganism in all aliquots collected. It was verified the importance of brushing the biopsy channel for correct removal of microorganisms. It was concluded that the reuse of enzyme detergent solutions contributed to the contamination of the endoscopes with potentially pathogenic microorganisms. It is necessary to re-evaluate institutional protocols, in order to comply with Anvisa's guidance through RDC nº. 55 of November 14, 2012 that enzymatic detergents should not be reused under loss of product efficiency. The physical characteristics of the enzymatic detergents must be observed by the health services according to the parameters established by the manufacturers.(AU)

Pseudomonas spp: contamination sources in bulk tanks of dairy farms / Pseudomonas spp: fontes de contaminação em tanques de expansão em fazendas leiteiras

This study focused on isolating Pseudomonas spp. during milking process in ten dairy farms with manual and mechanical milking systems during dry and rainy seasons, and evaluating DNA homology and patterns of distribution between isolates, in order to identify main sources of milk contamination by Pseudomonas spp. A total of 167 isolates of Pseudomonas spp. were obtained from water, milkers' hands, cows' teats, teat cups, cooling tanks and raw milk. Bacteria of Pseudomonas spp. genus were isolated from 85 and 82 sampling points in dairy farms with manual and mechanical milking system, respectively. A significant difference (p=0.02) on Pseudomonas spp. isolation was observed among samples of surface of cows' teats before and after pre-dipping, but no significant difference (p>0.05) was observed among milking systems or seasons. The possibility of the same Pseudomonas spp. patterns are distributed in different farms and seasons using Amplified Fragment Length Polymorphism (AFLP) technique was demonstrated. Milkers' hands, surface of cows' teats, teat cups and cooling tanks were associated with raw milk contamination with Pseudomonas spp. on farms with manual and mechanical milking system, showing that regardless of the type of milking system and season, proper hygiene procedures of equipment, utensils and workers' hands are essential to avoid contamination of the milk and, therefore, improve milk quality.(AU)

Este estudo se propôs a isolar Pseudomonas spp. durante o processo de ordenha em dez fazendas com sistemas manuais e mecanizados, durante as estações seca e chuvosa, além de avaliar a homologia do DNA e seus padrões de distribuição entre os isolados, a fim de se determinar as principais fontes de contaminação do leite. Cento e sessenta e sete isolados de Pseudomonas spp. foram obtidos a partir de amostras de água, mãos de ordenhadores, tetos, teteiras, tanques de resfriamento e leite cru armazenado, sendo 85 e 82 pontos de amostragem em fazendas com sistemas de ordenha manual e mecânico, respectivamente. Diferença estatisticamente significativa foi encontrada entre os isolados observados entre a superfície dos tetos antes e após o pré-dipping (p=0,02), mas nenhuma diferença foi encontrada entre sistemas de ordenha ou estações (p>0,05). A possibilidade do mesmo padrão de Pseudomonas spp. estar distribuído em diferentes fazendas ou estações foi avaliada pela técnica de Polimorfismo do Tamanho de Fragmento Amplificado (AFLP). As mãos de ordenhadores, superfície dos tetos das vacas, teteiras e tanques de resfriamento foram associados com a contaminação do leite cru, demonstrando que independente do tipo de ordenha e estação, a higiene adequada de equipamentos, utensílios e mãos dos ordenhadores é essencial para evitar contaminação do leite, e consequentemente aumentar sua qualidade.(AU)

Prevalence and Sensitivity of Bacilli and Pseudomonas in the Newborn's Oral Cavity

Abstract The aim of this study was to isolate Enterobacteria and Pseudomonas from the oral cavity of hospitalized newborns (NB) and determine their prevalence and the sensitivity profile to most commonly used antibiotics for this age group. Samples from the oral cavity of NB from 24 to 48 h age were collected using swabs. The samples were inoculated on MacConkey agar, incubated and the colonies counted and identified. For each strain, the minimum inhibitory concentration (MIC) was determined using agar dilution test. Tests for enterobacteria producing extended spectrumβ-lactamases (ESBL) were performed using agar diffusion. Descriptive statistics was used for data analysis. Two of the isolated strains were submitted to the susceptibility test in biofilm. Of the collected samples, 8% presented Enterobacteria (mean of 6,141 CFU/mL) and no Pseudomona species was isolated. Positive samples were from NB in accommodation set or in the NB nursery. Enterobacter was the most prevalent genus and some strains were resistant to ampicillin, gentamicin and cephalothin. No ESBL strain was detected. Microorganisms in biofilms were resistant to all antibiotics, with concentrations four times higher than MIC. The presence of enterobacteria in the oral cavity of newborns, especially some strains resistant to normally used antibiotics, warns to the need for care to avoid the early colonization of this niche and the occurrence of a possible hospital infection in this age group.

Resumo O objetivo foi isolar enterobactérias e Pseudomonas da cavidade oral de recém-nascidos hospitalizados (RN) e determinar a prevalência e o perfil de sensibilidade aos antibióticos mais comumente utilizados para este grupo etário. Foram coletadas amostras da cavidade oral de NB com idade de 24-48 horas, usando swab. As amostras foram inoculadas em ágar MacConkey, incubadas e, as colônias contadas e identificadas. Para cada cepa, a concentração inibitória mínima (CIM) foi determinada utilizando teste de ágar diluição. Testes para enterobactérias produtoras de b-lactamases de espectro estendido (ESBL) foram realizados utilizando difusão em ágar. Estatística descritiva foi utilizada para análise dos resultados. Duas das cepas isoladas foram submetidas ao teste de susceptibilidade em biofilme. Das amostras coletadas, 8% apresentaram enterobactérias (média de 6,141 UFC / ml) e nenhuma espécie de Pseudomonas foi isolada. As amostras positivas foram de RN de alojamento conjunto ou RN de berçário. Enterobacter foi o gênero mais prevalente e algumas cepas foram resistentes à ampicilina gentamicina e cefalotina. Não foi detectada cepa ESBL. Micro-organismos em biofilme foram resistentes a todos os antibióticos, em concentrações quatro vezes superiores ao MIC. A presença de enterobactérias em cavidade oral de recém-nascidos, especialmente algumas cepas resistentes aos antibióticos normalmente utilizados, alerta para a necessidade de cuidados, evitando a colonização precoce deste nicho e a ocorrência de possível infecção nosocomial neste grupo etário.

Draft genome sequence of a caprolactam degrader bacterium: Pseudomonas taiwanensis strain SJ9

Abstract Pseudomonas taiwanensis strain SJ9 is a caprolactam degrader, isolated from industrial wastewater in South Korea and considered to have the potential for caprolactam bioremediation. The genome of this strain is approximately 6.2 Mb (G + C content, 61.75%) with 6,010 protein-coding sequences (CDS), of which 46% are assigned to recognized functional genes. This draft genome of strain SJ9 will provide insights into the genetic basis of its caprolactam-degradation ability.

Emergence of colistin resistance in the largest university hospital complex of São Paulo, Brazil, over five years

Abstract Colistin resistance involving Gram-negative bacilli infections is a challenge for health institutions around of the world. Carbapenem-resistance among these isolates makes colistin the last therapeutic option for this treatment. Colistin resistance among Enterobacteriaceae, Acinetobacter spp., and Pseudomonas spp. was evaluated between 2010 and 2014 years, at Hospital das Clínicas, São Paulo, Brazil. Over five years 1346 (4.0%) colistin resistant Gram-negative bacilli were evaluated. Enterobacteriaceae was the most frequent (86.1%) pathogen isolated, followed by Acinetobacter spp. (7.6%), and Pseudomonas spp. (6.3%). By temporal analysis there was a trend for an increase of colistin resistance among Enterobacteriaceae, but not among non-fermentative isolates. Among 1346 colistin resistant isolates, carbapenem susceptibility was observed in 21.5%. Colistin resistance in our hospital has been alarmingly increased among Klebsiella pneumoniae isolates in both KPC positive and negative, thus becoming a therapeutic problem.

Screening of alginate lyase-producing bacteria and optimization of media compositions for extracellular alginate lyase production

Background: Alginate is a linear polysaccharide consisting of guluronate [polyG] and mannuronate [polyM] subunits

Methods: In the initial screening of alginate-degrading bacteria from soil, 10 isolates were able to grow on minimal medium containing alginate. The optimization of cell growth and alginate lyase [algL] production was carried out by the addition of 0.8% alginate and 0.2-0.3 M NaCl to the culture medium. Of 10 isolates, one was selected based on its fast growth rate on minimal 9 medium containing 0.4% sodium alginate. The selected bacterium, identified based on morphological and biochemical characteristics, as well as 16S rDNA sequence data, was confirmed to be an isolate belonging to the genus Bacillus and designated as Bacillus sp. TAG8

Results: The results showed the ability of Bacillus sp. TAG8 in utilizing alginate as a sole carbon source. Bacillus sp. TAG8 growth and algL production were augmented with an increase in sodium alginate concentration and also by the addition of 0.2-0.3 M NaCl. Molecular analysis of TAG8 algL gene showed 99% sequence identity with algL of Pseudomonas aeruginosa PAO1. The algL produced by Bacillus sp. TAG8 cleaved both polyM and polyG blocks in alginate molecule, as well as acetylated alginate residues, confirming the bifunctionality of the isolated lyase

Conclusion: The identification of novel algL genes from microbial communities constitutes a new approach for exploring lyases with specific activity against bacterial alginates and may thus contribute to the eradication of persistent biofilms from clinical samples

Occurrence and antimicrobial susceptibility of enteric rods and pseudomonads isolated from the dental prostheses biofilm

ABSTRACT Aspiration of oral bacteria leads to cardiac and respiratory infectious diseases and dentures can act as a reservoir for pathogenic microorganisms. Objective: To determine the occurrence and the in vitro antimicrobial susceptibility of enteric rods and pseudomonads from the denture biofilm of 52 subjects at the Center for Dental Specialties of Sobral/ Ceara, Brazil. Material and Methods: Denture biofilm was collected and samples plated on MacConkey agar. The isolated bacterial colonies were identified using the BBL Crystal enteric/non-fermenter system. Antibiotic bacterial susceptibility was assessed by the disc diffusion method of amoxicillin, amoxicillin/clavulanic acid, doxycycline, tetracycline, tobramycin, imipenem, cefotaxime, and ciprofloxacin. The Minimum Inhibitory Concentration (MIC) of cefotaxime, tobramycin, doxycycline, imipenem, and ciprofloxacin was determined for 40 species by E-test. Results: 34 subjects (65.4%) harbored enteric rods in their prostheses. Klebsiella pneumoniae (26.5%), Escherichia coli (23.5%), and Enterobacter aerogenes (23.5%) were the most prevalent species. All organisms were susceptible to ciprofloxacin and most species were resistant to amoxicillin or amoxicillin/clavulanic acid, demonstrating variable sensitivity patterns to other antimicrobials. However, the MIC showed the emergence of strains with reduced sensitivity to ciprofloxacin (MIC90≥3 μg/ mL) and cefotaxime (MIC90≥2 μg/mL). Conclusion: The findings show high prevalence of nosocomial diseases-related bacterial species and low susceptibility to antimicrobial drugs. Therefore, these results imply caution against the indiscriminate use of broad spectrum antibiotics in dental practice.

Carbazole degradation in the soil microcosm by tropical bacterial strains

In a previous study, three bacterial strains isolated from tropical hydrocarbon-contaminated soils and phylogenetically identified as Achromobacter sp. strain SL1, Pseudomonas sp. strain SL4 and Microbacterium esteraromaticum strain SL6 displayed angular dioxygenation and mineralization of carbazole in batch cultures. In this study, the ability of these isolates to survive and enhance carbazole degradation in soil were tested in field-moist microcosms. Strain SL4 had the highest survival rate (1.8 x 107 cfu/g) after 30 days of incubation in sterilized soil, while there was a decrease in population density in native (unsterilized) soil when compared with the initial population. Gas chromatographic analysis after 30 days of incubation showed that in sterilized soil amended with carbazole (100 mg/kg), 66.96, 82.15 and 68.54% were degraded by strains SL1, SL4 and SL6, respectively, with rates of degradation of 0.093, 0.114 and 0.095 mg kg−1 h−1. The combination of the three isolates as inoculum in sterilized soil degraded 87.13% carbazole at a rate of 0.121 mg kg−1 h−1. In native soil amended with carbazole (100 mg/kg), 91.64, 87.29 and 89.13% were degraded by strains SL1, SL4 and SL6 after 30 days of incubation, with rates of degradation of 0.127, 0.121 and 0.124 mg kg−1 h−1, respectively. This study successfully established the survivability (> 106 cfu/g detected after 30 days) and carbazole-degrading ability of these bacterial strains in soil, and highlights the potential of these isolates as seed for the bioremediation of carbazole-impacted environments.

Search for endophytic diazotrophs in barley seeds

Eight endophytic isolates assigned to Pseudomonas, Azospirillum, and Bacillus genera according to pheno-genotypic features were retrieved from barley seeds under selective pressure for nitrogen-fixers. Genetic relationships among related isolates were investigated through RAPD. Six isolates displayed nitrogen-fixing ability, while all could biosynthesize indolacetic acid in vitro and showed no antibiosis effects against Azospirillum brasilense Az39, a recognized PGPR.

Prevalence and risk factors of carbapenem-resistant gram negative bacilli in Assiut University Hospital

Carbapenem-resistant Gram negative bacilli [CRGNB] resulting from carbapenemase enzyme production have been reported to be an important cause of nosocomial infection and are a critical therapeutic problem worldwide. This study was conducted to determine the prevalence of carbapenem-resistant Gram negative bacilli in Asiut University Hospital and relevant risk factors associated with its occurrence. The study was conducted over a period of 12 month from January 2011 to January 2012 on 355 specimen of 134 nosocomialy infected patients, aged two month to 82 years, admitted to the ICUs at Assiut University Hospital. Patient demographics, comorbidities, antibiotics, invasive devices were determined to identify risk factors associated with CRGNB infections. Three hundred and fifty five Gram negative bacilli isolates [47.92%] were isolated from patients. Ninety seven [27.17%] of Gram negative bacilli isolates were carbapenem-resistant. Patients aged above 40 years, male sex, prior antibiotic treatment, the presence of a urinary catheter, mechanical ventilation and central line in ICU were the most prevalent risk factors associated with the accurence of nosocomial CRGNB infections. The prevalence of CRGNB was 27.17% among GNB isolates. Patients aged above 40 years, male sex, prior antibiotic treatment, the presence of a urinary catheter, mechanical ventilation and central line in ICU were the most prevalent risk factors Interventions aimed reducing initial broad spectrum antibiotics are clearly needed to help control the spread in of these difficult to treat infections

Antimicrobial susceptibility profile of Pseudomonas spp. isolated from a swine slaughterhouse in Dourados, Mato Grosso do Sul State, Brazil / Antimicrobial susceptibility profile of Pseudomonas spp. isolated from a swine slaughterhouse in Dourados, Mato Grosso do Sul State, Brazil.

The present work sought to detect the presence of Pseudomonas spp. at different stages of an effluent treatment plant using the Australian system of stabilization ponds, and to determine the susceptibility of those isolates to different antimicrobials. Thirty-four isolates of Pseudomonas spp. derived from effluent treatment station water samples were collected near the transfer ducts between the ponds in November/2008 and december/2009. Among the Pseudomonas spp. isolates, 47.05

showed susceptibility to all antimicrobials tested, 20.58

were resistant to cefepime, and 24

showed intermediate resistance to streptomycin. No Pseudomonas spp. isolates were found in the final pond, or in post-treatment effluents. The Pseudomonas spp. isolates did not exhibit multiresistance to the antimicrobials tested.

Hexavalent chromium reduction by aerobic heterotrophic bacteria indigenous to chromite mine overburden

Microbiological analysis of overburden samples collected from chromite mining areas of Orissa, India revealed that they are rich in microbial density as well as diversity and dominated by Gramnegative (58%) bacteria. The phenotypically distinguishable bacterial isolates (130) showed wide degree of tolerance to chromium (2-8 mM) when tested in peptone yeast extract glucose agar medium. Isolates (92) tolerating 2 mM chromium exhibited different degrees of Cr+6 reducing activity in chemically defined Vogel Bonner (VB) broth and complex KSC medium. Three potent isolates, two belonging to Arthrobacter spp. and one to Pseudomonas sp. were able to reduce more than 50 and 80% of 2 mM chromium in defined and complex media respectively. Along with Cr+6 (MIC 8.6-17.8 mM), the isolates showed tolerance to Ni+2, Fe+3, Cu+2 and Co+2 but were extremely sensitive to Hg+2 followed by Cd+2, Mn+2 and Zn+2. In addition, they were resistant to antibiotics like penicillin, methicillin, ampicillin, neomycin and polymyxin B. During growth under shake-flask conditions, Arthrobacter SUK 1201 and SUK 1205 showed 100% reduction of 2 mM Cr+6 in KSC medium with simultaneous formation of insoluble precipitates of chromium salts. Both the isolates were also equally capable of completely reducing the Cr+6 present in mine seepage when grown in mine seepage supplemented with VB concentrate