RESUMEN
The objective of this study was to analyse microbiological organisms in different locations and regions for physical activity in the city of João Pessoa, Brazil. Samples were collected on various objects used, such as: mattresses, drinking fountains, gloves, cell phones and others. The samples were collected in João Pessoa-PB, following the Standard Operating Procedure-SOP/ Microbiology of a specialized laboratory. The collection took place in the five macro-regions: North, South, East, West and Center. Foreach region samples were collected in one public place (square), a private one (gym) and one school (public or private), totaling fifteen collected sites and 450 samples. The following microorganisms were studied in all analyzed surfaces: Bacillus sp, Escherichia Coli, Klebsiella sppor Enterobacter sppand Coag. Neg. Staphylococcus.All regions had a high contamination level by some microorganism. The highest rates were found in the western, central and northern regions -96, 94 and 93% respectively. The Coag. Neg.Staphylococcus presented the highest and lowest incidence rates in the South and East regions, with 43.33 and 6.67%, respectively, as well as Klebsiella sppor Enterobacter spp, which presented high levels. It is concluded that there is a microorganisms' contamination in the most varied places and regions where physical activity practices are developed, with a predominance of Coag. Neg.Staphylococcusand Klebsiella sppor Enterobacter spp. These results lead to a warning about the hygiene importance in places for physical activity practice, especially in pandemic times (COVID-19), since almost all the evaluated surfaces were contaminated.
Asunto(s)
Higiene , Centros de Acondicionamiento/provisión & distribución , COVID-19/patología , Instituciones Académicas/provisión & distribución , Bacillus/patogenicidad , Ejercicio Físico/fisiología , Contaminación Biológica , Enterobacter/patogenicidad , Microbiología Ambiental , Escherichia/patogenicidad , Pandemias/estadística & datos numéricos , Klebsiella/patogenicidad , NoxasRESUMEN
This study describes the effect of bactofugation (10,000 × g in a continuous flow of 10,000 L/h) of three batches of raw milk on total bacterial count (TBC) and aerobic spore count, and it also shows the effect on the microbial diversity of spore-forming bacteria by analysing their genetic variability through molecular approaches. Given that milk must be preheated to approximately 55 °C before being bactofuged, for comparison, the three batches were evaluated at different stages as refrigerated raw, preheated, and bactofuged milk. For preheated milk, it was found that bactofugation caused a significant reduction (p < 0.05) of 99.52% (from 4.5 × 106 to 2.1 × 104 CFU/mL) in the mean TBC and of 95% (from 333 to 17 CFU/mL) in the aerobic mesophilic spore count. Due to the effect of bactofugation on preheated milk, a reduction of 82% was observed in both TBC and aerobic spore count. With respect to diversity, 107 isolates from raw milk, prior to bactofugation, and 16 isolates from bactofuged milk were recovered and grouped into 40 and 8 clusters, respectively. The predominant species detected in raw and preheated milk were Bacillus toyonensis (63% - 20 clusters) and Lysinibacillus fusiformis (15% - 8 clusters). Proportionally, B. toyonensis (69% - 6 clusters) and L. fusiformis (25% - 1 cluster) were predominant in bactofuged milk. B. pumilus, L. varians, B. flexus, B. invictae, and B. megaterium, bacteria with a known milk spoilage potential, were isolated from milk prior to bactofugation, and they reduced to undetectable levels in bactofuged milk. Bactofugation of milk, therefore, reduces the TBC and aerobic spore count, with a significant effect in reducing the microbial diversity of spore-forming bacteria, proportional to their incidence in raw milk. Therefore, bactofugation can be an alternative to increase the shelf life and technological potential of milk.(AU)
Esse estudo descreve o efeito da bactofugação (10,000 × g em fluxo contínuo de 10,000 L/h) de três lotes de leite cru nas contagens bacterianas totais (CBT) e de esporos aeróbios, verificando também o efeito sobre a diversidade microbiana dos formadores de esporos por abordagem molecular de variabilidade genética. Como o leite a ser bactofugado deve ser pré-aquecido (≈55ºC), os três lotes foram avaliados enquanto cru refrigerado, pré-aquecido e bactofugado. Em associação com o pré-aquecimento, foi verificado que a bactofugação promoveu a redução significativa (p < 0.05) de 99,52% (4,5 x 106 para 2,1 x 104 UFC/mL) na contagem bacteriana total e 95% (333 para 17 UFC/mL) dos esporos aeróbios mesófilos. Considerando o efeito isolado da bactofugação sobre o leite já pré-aquecido, foi observada a redução de 82% tanto para CBT quanto para formadores de esporos. Em relação à diversidade, foram recuperados 107 isolados do leite anterior à bactofugação e 16 isolados do leite bactofugado, agrupados em 40 e 8 clusters, respectivamente. Foi observado predomínio das espécies Bacillus toyonensis (63% - 20 clusters) e Lysinibacillus fusiformis (15% - 8 clusters) no leite cru e pré-aquecido e, proporcionalmente, B. toyonensis (69% - 6 clusters) e L. fusiformis (25% - 1 cluster) no leite bactofugado. Bacillus pumilus, Lysinibacillus varians, B. flexus, B. invictae, e B. megaterium, isolados do leite antes da bactofugação e com potencial deteriorante conhecido, foram reduzidos a níveis indetectáveis no leite bactofugado. A bactofugação do leite, portanto, reduz a CBT e as contagens de esporos aeróbios, também com efeito significativo na redução da diversidade de formadores de esporos, proporcionalmente, conforme a sua incidência no leite cru, tendo potencial para ser utilizado como alternativa para aumento da vida útil e potencial tecnológico do leite.(AU)
Asunto(s)
Esporas , Bacillus/patogenicidad , Variación Genética , Centrífugas/análisisRESUMEN
I report here the genome sequences of a Bacillus paranthracis strain isolated from book page surface. The presented data show a new study field for this species, which is frequently encountered in several environment, including soil, rhizosphere and notably human samples. I provide some insights about genomic content of Bacillus paranthracis, for example the presence of multiple antibiotic resistance genes, genes for polyhydroxybutyrate metabolism, 120 genes related to stress resistance and pathogenicity-related genes such as phospholipase C, metalloprotease and a cluster for non-hemolytic enterotoxin. In vitro tests showed that this isolate has motility, ability to produce biofilm, cytotoxic and enterotoxic ability, which makes this isolate a potential pathogen.
Asunto(s)
Bacillus/genética , Bacillus/patogenicidad , Libros , Farmacorresistencia Bacteriana/genética , Genoma Bacteriano , Antibacterianos/farmacología , Bacillus/aislamiento & purificación , Brasil , VirulenciaRESUMEN
BACKGROUND: The study of the mechanisms by which larvae of the Culex quinquefasciatus mosquito survive exposure to the entomopathogen Lysinibacillus sphaericus has benefited substantially from the generation of laboratory-selected colonies resistant to this bacterium. One such colony, RIAB59, was selected after regular long-term exposure of larvae to the L. sphaericus IAB59 strain. This strain is characterized by its ability to produce the well known Binary (Bin) toxin, and the recently characterized Cry48Aa/Cry49Aa toxin, able to kill Bin-resistant larvae. Resistance to Bin is associated with the depletion of its receptor, Cqm1 α-glucosidase, from the larvae midgut. This study aimed to identify novel molecules and pathways associated with survival of the RIAB59 larvae and the resistance phenotype. METHODS: A transcriptomic approach and bioinformatic tools were used to compare the profiles derived from the midguts of larvae resistant and susceptible to L. sphaericus IAB59. RESULTS: The RNA-seq profiles identified 1355 differentially expressed genes (DEGs), with 673 down- and 682 upregulated transcripts. One of the most downregulated DEGs was cqm1, which validates the approach. Other strongly downregulated mRNAs encode the enzyme pantetheinase, apolipoprotein D, lipases, heat-shock proteins and a number of lesser known and hypothetical polypeptides. Among the upregulated DEGs, the top most encodes a peroxisomal enzyme involved in lipid metabolism, while others encode enzymes associated with juvenile hormone synthesis, ion channels, DNA binding proteins and defense polypeptides. Further analyses confirmed a strong downregulation of several enzymes involved in lipid catabolism while the assignment of DEGs into metabolic pathways highlighted the upregulation of those related to DNA synthesis and maintenance, confirmed by their clustering into related protein networks. Several other pathways were also identified with mixed profiles of down- and upregulated transcripts. Quantitative RT-PCR confirmed the changes in levels seen for selected mRNAs. CONCLUSIONS: Our transcriptome-wide dataset revealed that the RIAB59 colony, found to be substantially more resistant to Bin than to the Cry48Aa/Cry49Aa toxin, developed a differential expression profile as well as metabolic features co-selected during the long-term adaptation to IAB59 and that are most likely linked to Bin resistance.
Asunto(s)
Bacillus/patogenicidad , Culex/genética , Culex/microbiología , Resistencia a la Enfermedad/genética , Animales , Toxinas Bacterianas/metabolismo , Biología Computacional , Sistema Digestivo/enzimología , Femenino , Perfilación de la Expresión Génica , Genes de Insecto , Larva/genética , Larva/microbiología , Fenotipo , RNA-Seq , alfa-Glucosidasas/metabolismoRESUMEN
Bacillus cereus sensu lato also known as B. cereus group is composed of an ecologically diverse bacterial group with an increasing number of related species, some of which are medically or agriculturally important. Numerous eï¬orts have been undertaken to allow presumptive diï¬erentiation of B. cereus group species from one another. FCC41 is a Bacillus sp. strain toxic against mosquito species like Aedes aegypti, Aedes (Ochlerotatus) albifasciatus, Culex pipiens, Culex quinquefasciatus, and Culex apicinus, some of them responsible for the transmission of vector-borne diseases. Here, we report the complete genome sequence of FCC41 strain, which consists of one circular chromosome and eight circular plasmids ranging in size from 8 to 490 kb. This strain harbors six crystal protein genes, including cry24Ca, two cry4-like and two cry52-like, a cry41-like parasporin gene and multiple virulence factors. The phylogenetic analysis of the whole-genome sequence of this strain with molecular approaches places this strain into the Bacillus wiedmannii cluster. However, according with phenotypical characteristics such as the mosquitocidal activity due to the presence of Cry proteins found in the parasporal body and cry genes encoded in plasmids of different sizes, indicate that this strain could be renamed as B. wiedmannii biovar thuringiensis strain FCC41.
Asunto(s)
Bacillus/genética , Genoma Bacteriano , Plásmidos , Bacillus/patogenicidad , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana/genética , Endotoxinas/genética , Proteínas Hemolisinas/genética , Control de Mosquitos , Filogenia , Secuenciación Completa del GenomaRESUMEN
O objetivo do presente trabalho foi descrever um caso de osteomielite em papagaio verdadeiro (Amazona aestiva,) com fratura no membro pélvico esquerdo, acompanhada de osteólise, que foi atendido no Hospital Veterinário da Universidade Federal de Mato Grosso, Campus Sinop-MT. Após exames clínicos, radiográficos, cultura bacteriana e antibiograma, confirmou-se o diagnóstico de osteomielite, causada pelas bactérias Escherichia coli e Bacillus spp. A osteomielite é um processo inflamatório, acompanhado de destruição óssea, causada por um microrganismo infectante e que pode ser encontrada nas formas aguda e crônica. O diagnóstico da osteomielite depende, não só de achados radiográficos, mas de outros exames como cultura e antibiograma. No presente caso, Escherichia coli mostrou-se sensível a todos os antibacterianos utilizados; mas Bacillus spp. mostrou-se resistente a alguns dos antibacterianos utilizados: Enrofloxacina, Ampicilina, Cloranfenicol, Tetraciclina, Norfloxacin e Ciprofloxacina. O tratamento escolhido para o caso foi amputação do membro acometido. Esta é a primeira descrição da ocorrência de osteomielite causada pela bactéria Escherichia coli e Bacillus spp. em um papagaio verdadeiro no estado do Mato Grosso.
The objective is to describe a case of osteomyelitis of a Blue-fronted Parrot (Amazona aestiva) with fractured left pelvic member accompanied of osteolysis, which was attended at the Veterinary Hospital of the Federal University of Mato Grosso, Campus Sinop-MT. After clinical examination, radiographic, bacterial culture and antibiotic susceptibility testing, was confirmed the diagnosis of osteomyelitis caused by Escherichia coli and Bacillus spp. Osteomyelitis is an inflammatory process accompanied by bone destruction caused by an infectious microorganism, can be found in acute and chronic forms. The diagnosis of osteomyelitis depends not only on radiographic findings but other tests such as culture and antibiotic susceptibility testing. In this case Escherichia coli was sensitive to all antimicrobial used, but Bacillus spp. was resistant to some of antibacterials used: Enrofloxacin, Ampicillin, Chloramphenicol, Tetracycline, Norfloxacin and Ciprofloxacin. The treatment chosen for the case was amputation of the affected limb. This is the first description of the occurrence of osteomyelitis caused by the bacterium Escherichia coli and Bacillus spp. in a Blue-fronted Parrot in the state of Mato Grosso, Brazil.
Asunto(s)
Animales , Adulto , Amazona , Bacillus/patogenicidad , Escherichia coli/patogenicidad , Osteomielitis/veterinaria , Osteólisis/veterinariaRESUMEN
O objetivo do presente trabalho foi descrever um caso de osteomielite em papagaio verdadeiro (Amazona aestiva,) com fratura no membro pélvico esquerdo, acompanhada de osteólise, que foi atendido no Hospital Veterinário da Universidade Federal de Mato Grosso, Campus Sinop-MT. Após exames clínicos, radiográficos, cultura bacteriana e antibiograma, confirmou-se o diagnóstico de osteomielite, causada pelas bactérias Escherichia coli e Bacillus spp. A osteomielite é um processo inflamatório, acompanhado de destruição óssea, causada por um microrganismo infectante e que pode ser encontrada nas formas aguda e crônica. O diagnóstico da osteomielite depende, não só de achados radiográficos, mas de outros exames como cultura e antibiograma. No presente caso, Escherichia coli mostrou-se sensível a todos os antibacterianos utilizados; mas Bacillus spp. mostrou-se resistente a alguns dos antibacterianos utilizados: Enrofloxacina, Ampicilina, Cloranfenicol, Tetraciclina, Norfloxacin e Ciprofloxacina. O tratamento escolhido para o caso foi amputação do membro acometido. Esta é a primeira descrição da ocorrência de osteomielite causada pela bactéria Escherichia coli e Bacillus spp. em um papagaio verdadeiro no estado do Mato Grosso.(AU)
The objective is to describe a case of osteomyelitis of a Blue-fronted Parrot (Amazona aestiva) with fractured left pelvic member accompanied of osteolysis, which was attended at the Veterinary Hospital of the Federal University of Mato Grosso, Campus Sinop-MT. After clinical examination, radiographic, bacterial culture and antibiotic susceptibility testing, was confirmed the diagnosis of osteomyelitis caused by Escherichia coli and Bacillus spp. Osteomyelitis is an inflammatory process accompanied by bone destruction caused by an infectious microorganism, can be found in acute and chronic forms. The diagnosis of osteomyelitis depends not only on radiographic findings but other tests such as culture and antibiotic susceptibility testing. In this case Escherichia coli was sensitive to all antimicrobial used, but Bacillus spp. was resistant to some of antibacterials used: Enrofloxacin, Ampicillin, Chloramphenicol, Tetracycline, Norfloxacin and Ciprofloxacin. The treatment chosen for the case was amputation of the affected limb. This is the first description of the occurrence of osteomyelitis caused by the bacterium Escherichia coli and Bacillus spp. in a Blue-fronted Parrot in the state of Mato Grosso, Brazil.(AU)
Asunto(s)
Animales , Adulto , Amazona , Osteomielitis/veterinaria , Escherichia coli/patogenicidad , Bacillus/patogenicidad , Osteólisis/veterinariaRESUMEN
Lysinibacillus sphaericus (Lsp) e uma bacteria entomopatogena que produz a toxina Binaria (Bin) com atividade larvicida para culicideos. A sua acao em Culex quinquefasciatus depende da ligacao da toxina Bin a alfa-glicosidase (Aglu) Cqm1, que atua como receptor no epitelio intestinal de larvas. Na colonia R2362, foram caracterizados dois alelos de resistencia ao Lsp: cqm1REC e cqm1REC-2, cujas mutacoes impedem a expressao da Aglu Cqm1. O objetivo deste trabalho foi avaliar a atividade catalitica da Cqm1 e comparar a atividade alfa-glicosidase e o desenvolvimento pre-imaginal de larvas de individuos susceptiveis (S) e resistentes (R) para cada alelo. Para isto, foram avaliados os seguintes parametros: atividade catalitica da Cqm1 recombinante; padrao de transcricao de outras Aglus paralogas a Cqm1; atividade de Aglus nativas em larvas; sobrevivencia de individuos frente a diferentes dietas. A Aglu Cqm1 mostrou atividade enzimatica otima a 37o C, pH 7,5-8,0 e utilizando o substrato sintetico pNalfaG. A atividade alfa-glicosidase total em larvas S e R foi similar, apesar da ausencia de expressao da Cqm1 nas larvas R. A investigacao in silico revelou 18 proteinas paralogas a Cqm1 e, dentre 11 investigadas, nove sao expressas em larvas S e R. A analise quantitativa de tres paralogas demonstrou que duas tem um padrao de transcricao mais elevado em larvas resistentes, sugerindo a existencia de um mecanismo de compensacao de expressao de alfa-glicosidases. O desenvolvimento pre-imaginal de larvas S foi decrescente nas seguintes dietas: racao de gatos, racao de peixes, leite desnatado, extrato de levedura e sacarose. De uma forma global, a taxa de sobrevivencia de larvas R foi inferior a S em todas as dietas testadas. Os dados obtidos mostram que as mutacoes ligadas aos alelos cqm1REC e cqm1REC-2 nao parecem impactar a atividade Aglu nas larvas e que o custo biologico observado poderia estar relacionado a outros genes e vias metabolicas.
Asunto(s)
Animales , alfa-Glucosidasas , Toxinas Bacterianas , Bacillus/patogenicidad , Culex , Culex/genética , Mutación/genética , Receptores de Superficie Celular/metabolismo , Resistencia a los Insecticidas/genéticaAsunto(s)
Antibiosis , Bacillus/patogenicidad , Agrobacterium tumefaciens/crecimiento & desarrollo , Bacillus/fisiología , Recuento de Colonia Microbiana , Fusarium/crecimiento & desarrollo , Pectobacterium carotovorum/crecimiento & desarrollo , Pseudomonas fluorescens/crecimiento & desarrollo , Pseudomonas syringae/crecimiento & desarrollo , Xanthomonas campestris/crecimiento & desarrolloRESUMEN
Diverse tetracyclines are used to prevent and control bacterial infections in livestock and farmed fish. These drugs are administered through the diet, but farmers seldom check whether feed contains antibiotic-resistant bacteria that may colonise their crops or transfer their resistance traits to species of veterinary relevance. To examine whether antibiotic dosage defines the abundance of antibiotic-resistant bacteria in animal feed, we determined the concentration of parental compounds and epimers of oxytetracycline (OTC), doxycycline, tetracycline and chlortetracycline, as well as the abundance and resistance level of OTC-resistant bacteria in samples of fish (n = 21), poultry (n = 21), swine (n = 21), and shrimp feed (n = 21) marketed in Costa Rica. Fish feed contained the highest amounts of tetracyclines (119-8365 mg kg(-1)) and the largest proportion of bacteria resistant to 10 µg ml(-1) (1.8-92.4%) or 100 µg ml(-1) of OTC (12.5-63.8%). Poultry (78-438 mg kg(-1)) and swine (41-1076 mg kg(-1)) feed had intermediate concentrations of tetracyclines and OTC-resistant bacteria (0.2-66% and 0.3-49%, respectively), whereas shrimp feed showed the lowest amounts of tetracyclines (21.5-50.3 mg kg(-1)), no OTC and no culturable OTC-resistant bacteria. In line with these results, the MIC50 of OTC for 150 isolates from fish and poultry feed was > 256 µg ml(-1), while that of 150 bacteria isolated from swine feed was 192 µg ml(-1). Phenotypic tests, fatty acid profiles and proteotypic analyses by matrix-assisted laser desorption/ionisation-time of flight mass-spectroscopy revealed that most OTC-resistant isolates were Gram-positive bacteria of low G+C% content from the genera Staphylococcus and Bacillus. Clear correlations between OTC dosage and feed colonisation with OTC-resistant bacteria were seen in medicated feed for fish (r = 0.179-0.651). Nonetheless, some unmedicated feed for fish, swine and poultry contained large populations of OTC-resistant bacteria, suggesting that raw materials and manufacturing processes may also influence carriage of OTC-resistant bacteria in animal feed.
Asunto(s)
Alimentación Animal/análisis , Alimentación Animal/microbiología , Contaminación de Alimentos/análisis , Bacterias Grampositivas/efectos de los fármacos , Bacterias Grampositivas/aislamiento & purificación , Tetraciclinas/análisis , Alimentación Animal/toxicidad , Animales , Bacillus/efectos de los fármacos , Bacillus/aislamiento & purificación , Bacillus/patogenicidad , Costa Rica , Peces , Microbiología de Alimentos , Bacterias Grampositivas/patogenicidad , Humanos , Oxitetraciclina/análisis , Oxitetraciclina/farmacología , Oxitetraciclina/toxicidad , Aves de Corral , Staphylococcus/efectos de los fármacos , Staphylococcus/aislamiento & purificación , Staphylococcus/patogenicidad , Sus scrofa , Resistencia a la Tetraciclina , Tetraciclinas/toxicidadRESUMEN
A resistência de Culex quinquefasciatus à toxina inseticida (Bin) de Bacillus sphaericus (Bsp) pode estar associada a uma falha da ligação da toxina com os receptores Cqm1, localizados no microvilli intestinal das larvas através de uma âncora GPI. Mutações no gene cqm1 podem impedir a expressão de proteínas Cqm1 funcionais e gerar um alto nível de resistência. O objetivo deste trabalho foi caracterizar e avaliar a frequência de alelos de resistência (r) em populações e colônias de C. quinquefasciatus. Neste estudo, o alelo r cqm1REC, selecionado e identificado anteriormente na colônia R2362, foi detectado por PCR alelo-específica em quatro populações de Recife com frequências entre 0,001 e 0,017. Em duas populações foram identificados novos alelos r, o cqm1REC-D16 e o cqm1REC- D25, com frequência entre 0,002-0,006. Estes alelos são caracterizados por deleções de 16 e 25-nt, respectivamente, as quais geram códon de terminação da tradução prematuro (CTTP) e não codificam proteínas com âncora GPI. Um segundo alelo r (cqm1REC- 2) foi identificado na colônia R2362 e possui uma mutação nonsense (G1292A) que também gera um CTTP, impedindo a localização de receptores Cqm1 no epitélio. O alelo cqm1REC-2 foi co-selecionado com o cqm1REC na colônia R2362 e uma análise da competição entre eles mostrou que o cqm1REC-2 predomina sob pressão de seleção com Bsp, enquanto que o cqm1REC é majoritário na ausência de Bsp. A expressão relativa dos alelos cqm1REC e cqm1REC-2, avaliada por PCR em tempo real, mostrou que ambos possuem uma expressão significativamente menor em relação ao cqm1. Amostras de microvilli intestinal de larvas homozigotas para cada alelo apresentaram uma baixa capacidade de interação com a toxina Bin, corroborando os dados de expressão gênica e o fenótipo de resistência. Este estudo mostrou a detecção e caracterização de novos alelos de C. quinquefasciatus que conferem resistência a Bsp e estes dados são fundamentais para o diagnóstico e manejo da resistência em programas de controle.
Asunto(s)
Alelos , Culex/ultraestructura , Frecuencia de los Genes , Resistencia a los Insecticidas , Control Biológico de Vectores , Receptores de Superficie Celular , Toxinas Bacterianas/toxicidad , Bacillus/patogenicidad , Mutación , Proteínas de Insectos/genéticaRESUMEN
Bin toxin from Bacillus sphaericus acts on Culex quinquefasciatus larvae by binding to Cqm1 midgut-bound receptors, and disruption of the cqm1 gene is the major cause of resistance. The goal of this work was to screen for a laboratory-selected resistance cqm1(REC) allele in field populations in the city of Recife, Brazil, and to describe other resistance-associated polymorphisms in the cqm1 gene. The cqm1(REC) allele was detected in the four nontreated populations surveyed at frequencies from 0.001 to 0.017, and sequence analysis from these samples revealed a novel resistant allele (cqm1(REC-D16)) displaying a 16-nucletotide (nt) deletion which is distinct from the 19-nt deletion associated with cqm1(REC). Yet a third resistant allele (cqm1(REC-D25)), displaying a 25-nt deletion, was identified in samples from a treated area exposed to B. sphaericus. A comparison of the three deletion events revealed that all are located within the same 208-nt region amplified during the screening procedure. They also introduce equivalent frameshifts in the sequence and generate the same premature stop codon, leading to putative transcripts encoding truncated proteins which are unable to locate to the midgut epithelium. The populations analyzed in this study contained a variety of alleles with mutations disrupting the function of the corresponding Bin toxin receptor. Their locations reveal a hot spot that can be exploited to assess the resistance risk through DNA screening.
Asunto(s)
Bacillus/patogenicidad , Toxinas Bacterianas/toxicidad , Culex/genética , Proteínas de Insectos/genética , Mutación , Receptores de Superficie Celular/genética , Alelos , Animales , Brasil , Culex/inmunología , Culex/microbiología , Polimorfismo GenéticoRESUMEN
El municipio Sifontes del estado Bolívar es la principal área endémica a malaria de Venezuela. Durante los últimos cinco años se ha reportado en este municipio un promedio anual cercano a 15 mil casos, alcanzándose durante 2009 la cifra de 20.282, lo que constituye una situación de epidemia. En este municipio se evaluó la persistencia de una formulación comercial de Bacillus sphaericus Neide (Vectolex CG 7,5%) en criaderos naturales de Anopheles marajoara, An. triannulatus y An. braziliensis. Para ello se realizaron dos experimentos en los cuales se evaluaron las dosis de 2 y 3 gr/m2 durante 60 y 90 días. Los resultados indican que hay diferencias en la persistencia por tipo de criadero y especie de anofelino. La tendencia general para todas las especies indica que el porcentaje de reducción de la población larvaria fue de 100% durante la primera semana, luego disminuyó paulatinamente hasta más o menos 40% después de los 28 días, para luego recuperarse a alrededor de 60% a los 45 días, manteniéndose así hasta el día 90 con ambas dosis. Este comportamiento es más evidente para An. marajoara, mientras que con An. triannulatus la eficacia se mantiene alrededor de 80% durante 90 días con 3 gr/m2. Sobre An. braziliensis, la eficacia se mantiene en 100% hasta el día 14 con ambas concentraciones, para luego caer abruptamente sin recuperación. Es la primera vez que se evalúa B. sphaericus sobre estas especies de anofelinos en Venezuela, considerándose estos resultados muy prometedores para el control de vectores
Sifontes municipality in Bolivar state is the main malaria endemic area in Venezuela. During the last five years an annual average of 14,000 cases has been reported, reaching 13,450 during 2008, resulting in an epidemic situation. A commercial formulation of Bacillus sphaericus Neide (Vectolex CG 7.5%), was evaluated in larval habitats of Anopheles marajoara, An. triannulatus and An. braziliensis. Two experiments were carried out in a lagoon and a pasture inundated area, 2 and 3 gr/m2 doses were evaluated during 60 and 90 days. The results point out that there are differences in the persistence depending on the type of larval habitat and anopheline species. The general trend indicated that for all the species the persistence of the Vectolex, therefore the reduction of the larval population was 100% during the first week. However, it felt under 40% after day 28, then recovered by day 45, and remaining around 40% for 90 days with both doses. A similar pattern was observed for An. marajoara, whereas for An. triannulatus the efficacy remained around 80% during 90 days only at 3 gr/m2. With An. braziliensis there was 100% persistence until day 14 with both doses, for then felt abruptly without recovering. This is the first time that B. sphaericus was evaluated for these anopheline species in Venezuela, considering these results promissory for the malaria control program
Asunto(s)
Humanos , Bacillus/efectos de la radiación , Bacillus/patogenicidad , Bacillus/ultraestructura , Enfermedades Transmisibles/epidemiología , Enfermedades Transmisibles/parasitología , Enfermedades Transmisibles/sangre , Vectores de Enfermedades/clasificación , Malaria , Salud PúblicaRESUMEN
The environmental toxicology of chemical pesticides have increased interest in the development and use of microbial pest control agents. In the present study four new Brazilian strains of Bacillus and one fungus were tested to evaluate the acute oral toxicity and clearance of these microbials in C57BL6 mice. No mortality was observed after exposure for any of the microorganisms tested. Clearance was significant after 30 days but for one strain of B. thuringiensis and one of B. sphaericus this time was not enough to completely eliminate the spores.
Asunto(s)
Bacillus/patogenicidad , Plaguicidas/toxicidad , Animales , Brasil , Femenino , Hongos/patogenicidad , Masculino , Ratones , Ratones Endogámicos C57BL , Control de Plagas/métodosRESUMEN
The use of brewery residues--yeast and trub--has been evaluated aiming to minimize the costs of the industrial production of Bacillus sphaericus-based bioinsecticide. Both brewery residues promoted growth and sporulation of the three B. sphaericus strains that were isolated from Brazilian soils (S1, S2, and S20). However, distinct growth and sporulation behaviors were observed in relation to the different nutritional conditions and strain used. The maximum sporulation percentage was obtained through the cultivation of S20 strain in brewery residual yeast. In general, the entomopathogenic biomasses produced showed good results for toxicity to Culex larvae. The minimum values of larvae population (LC50) were observed for the S20 strain grown on yeast brewery residue-containing media. After fermentation, a considerable decrease in the organic material of alternative media was verified, although the residual values were still higher than that considered appropriate for effluent discharge.
Asunto(s)
Bacillus/crecimiento & desarrollo , Bacillus/patogenicidad , Técnicas de Cultivo de Célula/métodos , Culex/crecimiento & desarrollo , Culex/microbiología , Control Biológico de Vectores/métodos , Aguas del Alcantarillado/microbiología , Animales , Biomasa , Reactores Biológicos/microbiología , Industria de Alimentos/métodos , Residuos Industriales/prevención & controlRESUMEN
This work demonstrates that Bin1 and Bin2 toxins, produced by Bacillus sphaericus strains IAB59 and 2362, respectively, share a binding site in midgut brush border membranes (BBMF) from Culex pipiens complex larvae. However, a colony selected with strain IAB59, displaying a resistance ratio of only 42-fold to IAB59, but a 162,000-fold resistance to strain 2362, was found to miss receptors for Bin2 in the BBMF. This correlates with results showing that Bin1, produced in strain IAB59, failed to bind specifically to BBMF from other colony highly resistant to strain 2362. Data indicate the loss of the BBMF bound receptor as a general mechanism of resistance to binary toxins in mosquito.
Asunto(s)
Bacillus/patogenicidad , Toxinas Bacterianas/metabolismo , Culex/efectos de los fármacos , Resistencia a los Insecticidas , Control Biológico de Vectores , Receptores de Superficie Celular/metabolismo , Animales , Bacillus/crecimiento & desarrollo , Bacillus/metabolismo , Toxinas Bacterianas/química , Toxinas Bacterianas/farmacología , Sitios de Unión , Unión Competitiva , Culex/crecimiento & desarrollo , Larva/efectos de los fármacos , Microvellosidades/metabolismoRESUMEN
Investigations on the inheritance and mechanism of resistance to Bacillus sphaericus Neide in Culex quinquefasciatus Say colonies, selected with strains C3-41 (RLCq1/C3-41) and 2362 (CqRL1/2362), were performed in China and Brazil, respectively. The progeny of reciprocal F1 crosses (susceptible female x resistant male and vice versa) from both resistant colonies responded alike in bioassays, indicating recessive inheritance. Data on larvae susceptibility from the backcross offspring between F1 and their respective susceptible and resistant parental colonies are consistent with a monofactorial and autosomal mode of inheritance. In vitro binding assays between 125I binary (Bin2) toxin and the brush border membrane fractions (BBMF) from CqRL1/2362 and RLCq1/C3-41 larvae showed that resistance, in both colonies, is caused by a failure in the binding step of the B. sphaericus Bin2 toxin to its specific midgut receptor. The specific and saturable binding of Bin2 toxin to BBMF from F1 larvae (CqRL1/2362 X susceptible counterpart) confirms the recessive inheritance of the resistance gene. Further studies are needed to advance understanding of B. sphaericus resistance.
Asunto(s)
Bacillus/patogenicidad , Culex/genética , Culex/microbiología , Animales , Bacillus/genética , Bacillus/crecimiento & desarrollo , Toxinas Bacterianas/genética , Cruzamientos Genéticos , Culex/inmunología , Inmunidad Innata , Larva , ReproducciónRESUMEN
AIMS: To investigate the potential antagonistic activity of Paenibacillus peoriae strain NRRL BD-62 against phytopathogenic micro-organisms and to determine the physiological and biochemical characteristics of the antimicrobial compound produced by this strain. METHODS AND RESULTS: Strain NRRL BD-62 showed a broad inhibition spectrum with activity against various phytopathogenic bacteria and fungi. Physico-chemical characterization of the antimicrobial activity showed that it was stable during heat treatment and was retained even after autoclave at 121 degrees C for 10 min. The compound was also stable after the treatment with organic solvents, hydrolytic enzymes and its activity was preserved at a wide range of pH. The partial purification carried out by Sephadex G25 gel filtration showed two profiles of inhibition against the indicator strains tested, suggesting at least two different substances with distinct molecular weight. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report on the production of antimicrobial substances in P. peoriae. Besides the antimicrobial inhibition capability, the strain NRRL BD-62 is also able to effectively fix molecular nitrogen, and produce chitinases and proteases as well, suggesting that further studies should be addressed to use P. peoriae strain NRRL BD-62 as a plant growth promoter and/or as a biocontrol agent in field experiments.