Outbreak of neonatal infection by an endemic clone of Serratia marcescens.

INTRODUCTION: The outbreak occurred between February and June 2006 and included identification of the cases, analysis of medical records, cultures from environmental sources, resistance analyses and genotyping profile of Serratia marcescens. METHODS: The cultures were composed of 13 blood isolates, 17 rectal and hand swabs and air sampling. RESULTS: The data obtained by pulsed-field gel electrophoresis exhibited three strains that contaminated 24 patients. Systemic infection was the most common in neonates with lower weight, long periods of hospitalization, premature delivery and the use of mechanical ventilation. CONCLUSIONS: This investigation revealed the multifactorial nature of the outbreak. An endemic clone of S. marcescens was detected.

Outbreak of neonatal infection by an endemic clone of Serratia marcescens / Surto de infecção neonatal a partir de clone endêmico de Serratia marcescens

INTRODUCTION: The outbreak occurred between February and June 2006 and included identification of the cases, analysis of medical records, cultures from environmental sources, resistance analyses and genotyping profile of Serratia marcescens. METHODS: The cultures were composed of 13 blood isolates, 17 rectal and hand swabs and air sampling. RESULTS: The data obtained by pulsed-field gel electrophoresis exhibited three strains that contaminated 24 patients. Systemic infection was the most common in neonates with lower weight, long periods of hospitalization, premature delivery and the use of mechanical ventilation. CONCLUSIONS: This investigation revealed the multifactorial nature of the outbreak. An endemic clone of S. marcescens was detected.

INTRODUÇÃO: O surto ocorreu entre fevereiro a junho de 2006 e incluiu identificação de casos, análise dos prontuários, culturas ambientais, análise de resistência e genotipagem dos isolados de Serratia marcescens. MÉTODOS: Os cultivos foram compostos de 13 isolados de sangue e 17 swabs de reto e mãos e amostras do ar. RESULTADOS: Os dados obtidos por eletroforese de campo pulsado evidenciaram três cepas que contaminaram 24 pacientes. Infecção sistêmica foi mais comum em neonatos com menor peso, longo tempo de internação, nascimento prematuro e uso de respiração mecânica. CONCLUSÕES: Foi evidenciada a natureza multifatorial do surto. Foi encontrado um clone endêmico de S. marcescens.

Occurrence and composition of class 1 and class 2 integrons in clinical and environmental O1 and non-O1/non-O139 Vibrio cholerae strains from the Brazilian Amazon.

This study identified and characterised class 1 and 2 integrons in clinical and environmental Vibrio cholerae O1 and non-O1/non-O139 strains isolated from the Brazilian Amazon. The aadA2 and aadA7 gene cassettes were found in class 1 integrons in two genotypes of environmental V. cholerae non-O1/non-O139. Empty integrons were found in strains from the Brazilian cholera epidemic. A class 2 integron was detected in one strain from the V. cholerae Amazonia lineage harbouring sat1 and aadA1 genes. All isolates were resistant to aminoglycosides, indicating aadA functionality. These findings suggest that environmental bacteria act as cassette reservoirs that favour the emergence of resistant pathogens.

Occurrence and composition of class 1 and class 2 integrons in clinical and environmental O1 and non-O1/non-O139 Vibrio cholerae strains from the Brazilian Amazon

This study identified and characterised class 1 and 2 integrons in clinical and environmental Vibrio cholerae O1 and non-O1/non-O139 strains isolated from the Brazilian Amazon. The aadA2 and aadA7 gene cassettes were found in class 1 integrons in two genotypes of environmental V. cholerae non-O1/non-O139. Empty integrons were found in strains from the Brazilian cholera epidemic. A class 2 integron was detected in one strain from the V. cholerae Amazonia lineage harbouring sat1 and aadA1 genes. All isolates were resistant to aminoglycosides, indicating aadA functionality. These findings suggest that environmental bacteria act as cassette reservoirs that favour the emergence of resistant pathogens.

Ocorrência de uma floração de cianobactérias tóxicas na margem direita do Rio Tapajós, no Município de Santarém (Pará, Brasil) / Occurrence of toxic cyanobacterial bloom in the left margin of the Tapajós River, in the Municipality of Santarém (Pará State, Brazil)

A presença de florações de cianobactérias e seus subprodutos interfere diretamente na qualidade da água, podendo introduzir efeitos negativos, tanto de ordem estética, como de saúde pública, devido à produção de compostos potencialmente tóxicos e carcinogênicos. O tipo mais comum de intoxicação envolvendo cianobactérias é ocasionado por microcistina-LR (hepatotoxina), a qual pode causar severos danos ao fígado. Assim, o objetivo deste estudo foi identificar os gêneros causadores de uma floração de cianobactérias no Rio Tapajós (Santarém, Pará, Brasil) no mês de março de 2007, bem como realizar bioensaios de toxicidade aguda, utilizando camundongos Swiss-webster. As amostragens foram realizadas em cinco pontos de coleta distribuídos na margem direita do Rio Tapajós, onde foram realizados arrastos horizontais, com o auxílio de uma rede para plâncton de 20 μm; e foram também coletadas amostras de água bruta (5.000 mL) em garrafas de polipropileno do tipo âmbar. Para a identificação dos organismos utilizou-se microscopia ótica. A determinação de microcistinas-LR foi realizada por meio das técnicas de Ensaio Imunoadsorvente Enzima-Associado e Cromatografia Líquida de Alta Pressão. As análises demonstraram que na altura dos pontos P01 e P02 ocorreu um desequilíbrio ecológico na comunidade fitoplanctônica, caracterizado pela proliferação intensa dos gêneros Anabaena e Microcystis. Nas amostras de água bruta, as concentrações de microcistina-LR registradas estão abaixo dos valores máximos permitidos na legislação brasileira para água de consumo; entretanto, é importante ressaltar que a floração, visualizada in locu, ocupava cerca de 10 cm da superfície da coluna d'água, e que, portanto, continha células de cianobactérias suficientes para provocar irritações cutâneas em pessoas que usassem o rio como balneário nesse período.

The presence of cyanobacterial blooms and their subproducts interferes directly in water quality and may cause negative effects, both aesthetically and to public health, due to the production of potentially toxic and carcinogenic compounds. The most common type of intoxication involving cyanobacteria is caused by microcystin-LR (hepatotoxin), which can cause severe damage to the liver. The objective of this study was to identify the genera that caused cyanobacterial blooms in the Tapajós River (Santarém, Pará, Brazil) in March 2007, as well as to execute acute toxicity bioassays in Swiss-webster mice. Sample collection was performed at five sampling points throughout the left margin of the Tapajós River, by horizontal dragging with the aid of a 20 μm plankton net. Samples of raw water (5,000 ml) were also collected in amber propylene bottles. Optical microscopy was applied to identify the organisms, and the determination of microcystin-LR was executed through ELISA and HPLC. The analyses showed that, at P01 and P02, there was an ecological imbalance in the phytoplanktonic community, characterized by an intense proliferation of the genera Anabaena and Microcystis. The concentrations of microcystin-LR reported in the raw water samples were below the maximum values permitted by Brazil's legislation for drinking water. However, it is important to note that the blooming observed in locu occupied around 10 cm of the water column surface and therefore presented cyanobacterial cells enough to cause rashes in people who swam or bathed in the rivers during this period.