Molecular epidemiology of a nosocomial outbreak due to Enterobacter cloacae and Enterobacter agglomerans in Campinas, São Paulo, Brazil Epidemiologia molecular de um surto de bacteriemia por Enterobacter cloacae e Enterobacter agglomerans ocorrido na região de Campinas, São Paulo, Brasil

A total of 73 isolates (57 Enterobacter cloacae and 16 Enterobacter agglomerans), recovered during an outbreak of bacteremia in the Campinas area, São Paulo, Brazil, were studied. Of these isolates, 61 were from parenteral nutrition solutions, 9 from blood cultures, 2 from a sealed bottle of parenteral nutrition solution, and one was of unknown origin. Of the 57 E. cloacae isolates, 54 were biotype 26, two were biotype 66 and one was non-typable. Of 39 E. cloacae isolates submitted to ribotyping, 87.2% showed the same banding pattern after cleavage with EcoRI and BamHI. No important differences were observed in the antimicrobial susceptibility patterns among E. cloacae isolates exhibiting the same biotype, serotype and ribotype. All E. agglomerans isolates, irrespective of their origin, showed same patterns when cleaved with EcoRI and BamHI. The results of this investigation suggest an intrinsic contamination of parenteral nutrition solutions and incriminate these products as a vehicle of infection in this outbreak.<br>Foram estudadas um total de 73 cepas (57 de E. cloacae e 16 E. agglomerans), isoladas durante um surto de bacteriemia ocorrido na região de Campinas, S. Paulo. Entre estas cepas, 61 foram isoladas de solução de nutrição parenteral, 9 de sangue, 2 de bolsa fechada de solução de nutrição parenteral e uma era de origem desconhecida. Entre as 57 cepas de E. cloacae, a maioria das cepas foram do biotipo 26/sorotipo O3 (39 cepas) e do biotipo 26/OR (13). Entre as 39 cepas de E. cloacae ribotipadas, 87,2% apresentaram o mesmo padrão de bandas com EcoRI e BamHI. Cepas de E. cloacae pertencentes ao mesmo biotipo, sorotipo e ribotipo não apresentaram diferenças significativas em relação ao padrão de sensibilidade aos agentes antimicrobianos. Todas as cepas de E. agglomerans, independente da origem, pertenciam ao mesmo ribotipo após a clivagem com EcoRI e BamHI. Os resultados obtidos sugerem uma contaminação intrínseca das soluções de nutrição parenteral, incriminando-as como o veículo de transmissão dos agentes etiológicos do surto

Bacterial phylotypes associated with the digestive tract of the sea urchin Paracentrotus lividus and the ascidian Microcosmus sp

We used sequencing and phylogenetic analysis of PCR-amplified 16S rRNA genes from bacteria that are associated with the esophagus/pharynx, stomach and intestine of two marine sympatric invertebrates but with different feeding mechanisms, namely the sea urchin Paracentrotus lividus (grazer) and the ascidian Microcosmus sp. (suspension feeder). Amplifiable DNA was retrieved from all sections except the pharynx of the ascidian. Based on the inferred phylogeny of the retrieved sequences, the sea urchin's esophagus is mainly characterized mostly by bacteria belonging to alpha-, gamma-Proteobacteria and Bacteriodetes, most probably originating from the surrounding environment. The stomach revealed phylotypes that belonged to gamma- and delta-Proteobacteria, Verrucomicrobia and Fusobacteria. Since the majority of their closest relatives are anaerobic species and they could be putative symbionts of the P lividus stomach, in which anaerobic conditions also prevail. Seven out of eight phylotypes found in the sea urchin's intestine belonged to sulfate reducing delta-Proteobacteria, and one to gamma-Proteobacteria, with possible nutritional activities, i.e. degradation of complex organic compounds which is beneficial for the animal. The bacterial phylotypes of the ascidian digestive tract belonged only to the phyla of Actinobacteria and Proteobacteria. The stomach phylotypes of the ascidian were related to pathogenic bacteria possibly originating from the water column, while the intestine seemed to harbour putative symbiotic bacteria that are involved in the degradation of nitrogenous and other organic compounds, thus assisting ascidian nutrition