Qualidade física de um latossolo vermelho sob sistema de semeadura direta e cultivo convencional / Physical quality of an oxisol under no-tillage and conventional tillage

Para garantir a sustentabilidade dos sistemas agrícolas, a compreensão e a quantificação do impacto do uso e manejo do solo na sua qualidade física são de fundamental importância. Nesse sentido, objetivou-se com este trabalho avaliar a qualidade de um Latossolo Vermelho sob cultivo convencional (CC) e sistema de semeadura direta (PD), por meio de diferentes indicadores físicos. Os sistemas de uso e manejo do solo foram: CC e PD por sete e oito anos consecutivos (solo de textura média) e CC e PD por nove e dez anos consecutivos (solo de textura argilosa). Foram determinadas, nas camadas de 0-0,10; 0,10-0,20 e 0,20-0,30 m, a resistência do solo à penetração, a porosidade total, a macroporosidade e a microporosidade, a retenção de água no solo, o índice S, a densidade, a densidade do solo máxima e também a densidade do solo relativa. Foi verificada grande variação da resistência do solo à penetração ao longo do ciclo das culturas da soja e do milho, sendo que seus maiores valores foram constatados nas camadas superficiais. Dentre os sistemas de manejo, o PD apresentou maior resistência do solo à penetração. Dentre os sistemas de manejo, o CC apresentou melhores resultados em relação aos indicadores de qualidade física do solo.

The understanding and quantification of the impact of tillage systems in their physical quality are fundamental in the development of sustainable agricultural systems. This study aimed to evaluate the quality of an Oxisol under conventional tillage (CT) and no-tillage system (NT), through different physical indicators. The management systems were: CT and NT for seven or eight consecutive years (medium textured soil) and CT and NT by nine and ten consecutive years (clay soil). Were determined, at the layers 0-0.10, 0.10-0.20; 0.20-0.30 m, soil resistance to penetration, total soil porosity, macroporosity and microporosity, soil water retention, S index, soil bulk density, maximum density and relative bulk density. Was observed great variation of soil resistance to penetration throughout the soybean and corn cycles, with its highest values were found in the surface layers. The NT showed greater resistance to penetration. Among the management systems, the results against indicators of soil physical quality were similar.

Comparação das técnicas de captura de híbridos e PCR para a detecção de HPV em amostras clínicas / Comparison of hybrid capture and PCR for HPV detection in clinical samples

INTRODUÇÃO E OBJETIVOS: São conhecidos mais de 100 tipos de papilomavírus humano (HPV), dos quais 30 têm sido reportados em infecções anogenitais. A infecção tem importância clínica, pois alguns tipos virais estão associados a lesões que podem progredir para o câncer cervical. Sabe-se que os métodos moleculares são muito importantes para o diagnóstico dessa infecção. O objetivo do estudo é comparar a detecção de HPV de alto risco pelo método de captura híbrida 2 (CH2) com a detecção do vírus pela reação em cadeia da polimerase convencional (PCRc) e em tempo real (PCR-TR). METODOLOGIA: Foram analisadas 56 amostras ectocervicais por CH2 e, após, por PCRc e PCR-TR. RESULTADOS: Ambas, PCRc e PCR-TR, apresentaram alta concordância entre si (95,1 por cento), enquanto a comparação entre as PCRs e a CH2 mostrou concordância razoável entre os resultados (PCRc = 90,2 por cento e PCR-TR = 87,8 por cento). DISCUSSÃO E CONCLUSÃO: A CH é aceita para a detecção do HPV, entretanto pode ser menos sensível em comparação com as técnicas de PCR. A PCR-TR tem a vantagem sobre a PCRc em termos de velocidade, sendo também um pouco mais sensível. Devido à alta sensibilidade e à rapidez, os métodos de PCR poderiam ser usados para a triagem de HPV em amostras ectocervicais.

INTRODUCTION AND OBJECTIVE: More than 100 types of human papillomaviruses (HPV) are known, of which 30 have been reported in anogenital infections. The infection has clinical importance, inasmuch as some viral types are associated with lesions that can progress to cervical cancer. Molecular methods are considered an important tool for the diagnosis of this infection. The objective of this study was to compare the detection of high risk HPV using hybrid capture 2 with HPV detection by conventional and real time PCR. METHODOLOGY: 56 ectocervical samples were analyzed by hybrid capture and after that by conventional and real time PCR. RESULTS: Both PCR and RT-PCR showed a high degree of correlation (95.1 percent), whereas the comparison between PCR and HC2 showed a fair correlation (90.2 percent and 87.8 percent for PCR and RT-PCR, respectively). DISCUSSION AND CONCLUSIONS: HC is widely accepted for the detection of HPV, however, it may lack sensitivity in comparison with PCR techniques. RT-PCR has further advantages over the conventional PCR in terms of speed as well as it is slightly more sensitive. Due to their high sensitivity and fast response, PCR methods could be used as a screening method for HPV detection in ectocervical samples.

Cutaneous infection caused by Corynebacterium pseudodiphtheriticum: a microbiological report.

We report here a rare case of cutaneous infection due to Corynebacterium pseudodiphtheriticum. The patient presented to the clinical laboratory with a skin ulcer on his left leg. Gram-stained preparation of the purulent secretion revealed the presence of numerous rod-shaped Gram-positive organisms in the absence of any other species. The organism was grown in pure culture on sheep blood agar and was further identified as C. pseudodiphtheriticum using a commercial identification system (API-Coryne, BioMérieux, France). The infection was successfully treated with ciprofloxacin. This case emphasizes the importance of the clinical microbiology laboratory in correctly identifying Gram-positive organisms obtained in pure culture from skin ulcers.

Cutaneous infection caused by Corynebacterium pseudodiphtheriticum: a microbiological report / Infecção cutânea causada por Corynebacterium pseudodiphtheriticum: relato microbiológico

We report here a rare case of cutaneous infection due to Corynebacterium pseudodiphtheriticum. The patient presented to the clinical laboratory with a skin ulcer on his left leg. Gram-stained preparation of the purulent secretion revealed the presence of numerous rod-shaped Gram-positive organisms in the absence of any other species. The organism was grown in pure culture on sheep blood agar and was further identified as C. pseudodiphtheriticum using a commercial identification system (API-Coryne, BioMérieux, France). The infection was successfully treated with ciprofloxacin. This case emphasizes the importance of the clinical microbiology laboratory in correctly identifying Gram-positive organisms obtained in pure culture from skin ulcers.

Reportamos o isolamento de Corynebacterium pseudodiphtheriticum de um caso de infecção cutânea. O paciente apresentou-se ao laboratório clínico com uma úlcera na perna esquerda. A coloração de Gram do material revelou a presença de bacilos Gram-positivos e ausência de outras espécies bacterianas. O organismo foi isolado em cultura pura no ágar sangue de carneiro e foi identificado como C. pseudodiphtheriticum através de um sistema de identificação comercial (API-Coryne, BioMérieux, França). A infecção foi tratada com sucesso através do uso de ciprofloxacina. Este caso reforça a importância do laboratório de microbiologia clínica na identificação de organismos Gram-positivos isolados de cultura pura de amostras de úlceras cutâneas.

Utility of the ceftazidime-imipenem antagonism test (CIAT) to detect and confirm the presence of inducible AmpC beta-lactamases among enterobacteriaceae.

Detection of AmpC beta-lactamase production by enterobacteria has been problematic. Contrary to ESBLs, no specific guidelines are available for detection and confirmation of AmpC production by clinical relevant microorganisms. Moreover, some bacterial species may produce inducible AmpC beta-lactamases that can be easily overlooked by routine susceptibility tests. We reported here a new test based on the strong inducible effect of imipenem on AmpC genes and the consequent antagonism with ceftazidime. This test is very simple and proved to be helpful in detecting AmpC-inducible enzymes among several species of clinical isolates.

Utility of the ceftazidime-imipenem antagonism test (CIAT) to detect and confirm the presence of inducible AmpC beta-lactamases among enterobacteriaceae

Detection of AmpC beta-lactamase production by enterobacteria has been problematic. Contrary to ESBLs, no specific guidelines are available for detection and confirmation of AmpC production by clinical relevant microorganisms. Moreover, some bacterial species may produce inducible AmpC beta-lactamases that can be easily overlooked by routine susceptibility tests. We reported here a new test based on the strong inducible effect of imipenem on AmpC genes and the consequent antagonism with ceftazidime. This test is very simple and proved to be helpful in detecting AmpC-inducible enzymes among several species of clinical isolates.

Fatal case of bacteremia caused by an atypical strain of Corynebacterium mucifaciens

Corynebacterium species have often been considered normal skin flora or contaminants; however, in recent years they have been increasingly implicated in serious infections. Moreover, many new species have been discovered and old species renamed, especially after molecular biology techniques were introduced. Corynebacterium mucifaciens is mainly isolated from blood and from other normally-sterile body fluids; it forms slightly yellow, mucoid colonies on blood agar. We report a fatal case of bacteremia due to an atypical strain of C. mucifaciens. This strain had atypical colony morphology; analysis of the 16S rRNA gene was used to define the species.

Fatal case of bacteremia caused by an atypical strain of Corynebacterium mucifaciens.

Corynebacterium species have often been considered normal skin flora or contaminants; however, in recent years they have been increasingly implicated in serious infections. Moreover, many new species have been discovered and old species renamed, especially after molecular biology techniques were introduced. Corynebacterium mucifaciens is mainly isolated from blood and from other normally-sterile body fluids; it forms slightly yellow, mucoid colonies on blood agar. We report a fatal case of bacteremia due to an atypical strain of C. mucifaciens. This strain had atypical colony morphology; analysis of the 16S rRNA gene was used to define the species.

Fatal bacteremia due to Anaerobiospirillum succiniciproducens: first description in Brazil.

Anaerobiospirillum succiniciproducens is an anaerobic, Gram-negative, spiral shaped bacteria, which is motile by means of bipolar tuffs of flagella. This organism appears to be a rare cause of bacteremia in humans, and it usually affects patients submitted to immunosuppressive therapy. Anaerobiospirillum succiniciproducens resembles Campylobacter spp. in Gram-stained preparations, however, it is considered resistant to most antimicrobial drugs that are used to treat Campylobacter infections. We observed Gram-negative, spiral shaped bacteria in Gram-stained preparations from blood culture flasks. Growth occurred only under anaerobic incubation, and identification to the species level was achieved by PCR amplification of the 16S rRNA gene, followed by direct sequencing and a GenBank homology search. To the best of our knowledge, this is the first reported Brazilian case of Anaerobiospirillum succiniciproducens bacteremia.

Fatal bacteremia due to Anaerobiospirillum succiniciproducens: first description in Brazil

Anaerobiospirillum succiniciproducens is an anaerobic, Gram-negative, spiral shaped bacteria, which is motile by means of bipolar tuffs of flagella. This organism appears to be a rare cause of bacteremia in humans, and it usually affects patients submitted to immunosuppressive therapy. Anaerobiospirillum succiniciproducens resembles Campylobacter spp. in Gram-stained preparations, however, it is considered resistant to most antimicrobial drugs that are used to treat Campylobacter infections. We observed Gram-negative, spiral shaped bacteria in Gram-stained preparations from blood culture flasks. Growth occurred only under anaerobic incubation, and identification to the species level was achieved by PCR amplification of the 16S rRNA gene, followed by direct sequencing and a GenBank homology search. To the best of our knowledge, this is the first reported Brazilian case of Anaerobiospirillum succiniciproducens bacteremia.

Application of broad-range bacterial PCR amplification and direct sequencing on the diagnosis of neonatal sepsis

Primers universais, que amplificam regiões conservadas de rDNA 23S, foram utilizados para analisar 306 amostras de cultivo de sangue obtidas de 295 neonatos com um ano ou menos de idade admitidos em unidades hospitalares de tratamento intensivo. O diagnóstico molecular baseado em seqüenciamento dos produtos de PCR foi comparado com os resultados obtidos do cultivo das amostras de sangue. Os resultados foram concordantes para 277 (90.5 per center) das 306 amostras testadas, incluindo 263 amostras PCR-negativo e cultura-negativa e 29 amostras cultura-positiva e PCR-positivo. Comparado com o método de cultivo, a técnica de PCR combinada com seqüenciamento, apresentou maior especificidade, 88 per center e 96,3 per center respectivamente, com valores preditivos positivos e negativos de 74,3 e 98,5 per center respectivamente. Concluímos que a técnica baseada em PCR utilizando amostras de cultivo de sangue, obtidas de neonatos com suspeita de sepse bacteriana, apresenta boa correlação com os métodos de cultivo convencionais. A metodologia de PCR/seqüenciamento apresenta aplicabilidade como técnica complementar para o diagnóstico da sepse neonatal. Esta metodologia fácil de ser executada fornece resultados confiáveis podendo ser recomendada para utilização no diagnóstico de amostras obtidas durante o tratamento antimicrobiano especialmente quando o resultado do cultivo permanece negativo. Apresenta, também, potencial de utilização na identificação de espécies bacterianas com problemas de classificação pelos métodos convencionais microbiológicos.

Quality control for microbiological culture media: Is it enough to follow the NCCLS M22-A2 procedures?

O uso de protocolos de controle de qualidade com padrões rígidos devem ser utilizados para garantir o isolamento dos microrganismos. Nosso objetivo foi o de avaliar um procedimento alternativo que nos permitisse detectar falhas de crescimento bacteriano em termos quantitativos, e comparação com o protocolo estabelecido pelo documento M22-A2 do NCCLS. Haemophilus influenzae apresentou diferença significativa de crescimento entre meio de cultivo de fontes distintas. Nos concluímos que, para alguns microrganismos fastidiosos, seja feita uma verificação quantitativa da capacidade de crescimento de cada meio de cultivo.

Quality control for microbiological culture media: Is it enough to follow the NCCLS M22-A2 procedures?

Stringent quality control protocols must be used in order to guaranty that a particular medium is able to recover all sort of organism that may be present in clinical samples. Our aim was to evaluate an alternative protocol that would allow us to detect medium failure to yield quantitative growth of selected pathogens, and compare with the document M22-A2 from NCCLS. The detection limit of Haemophilus influenzae was significantly different depending on media source. We conclude that for some fastidious microorganisms, quantitative verification of the growth capacity of the culture medium is advised.

O uso de protocolos de controle de qualidade com padrões rígidos devem ser utilizados para garantir o isolamento dos microrganismos. Nosso objetivo foi o de avaliar um procedimento alternativo que nos permitisse detectar falhas de crescimento bacteriano em termos quantitativos, e comparação com o protocolo estabelecido pelo documento M22-A2 do NCCLS. Haemophilus influenzae apresentou diferença significativa de crescimento entre meio de cultivo de fontes distintas. Nos concluímos que, para alguns microrganismos fastidiosos, seja feita uma verificação quantitativa da capacidade de crescimento de cada meio de cultivo.