Summary. Infection of HEp-2 cells by enteropathogenic Escherichia coli (EPEC) was examined by transmission and scanning electronmicroscopy. EPEC strains of serogroups 0 1 1 1 : K58 and 055 : K59 recently isolated from human patients did not exhibit enterotoxic activity, as judged by the Vero-cell and suckling-mouse assays, or invasive ability as judged by the Sereny test. These strains attached to and penetrated HEp-2 cells. Transmission electronmicroscopy showed bacteria in close contact with cell membranes 15 min after infection; later, intense swelling and budding of membranes and penetration of EPEC into the cell cytoplasm occurred. Intracellular bacteria were enclosed in membrane-bound vacuoles in the cell cytoplasm underlying localised adherence sites observed by light microscopy. Scanning electronmicroscopy showed morphologically altered membranes only at the sites of bacterial attachment. Bacteria inactivated by ultraviolet light were not internalised and cytochalasin B ( 2 10 mg/L) markedly inhibited uptake. These observations suggest that penetration of EPEC into HEp-2 cells occurs by an endocytic process in metabolically active bacteria.
Nosocomial infections are a relevant factor in complicating the recovery of patients interned for even minor causes. In a attempt to determine their origin it is crucial to consider that their origin is of an endogenous nature. Looking for an accessible expression of intestinal colonization we analyzed fecal samples from 3 separate groups of hospital patients collected after different lengths of time. For practical reasons one group was studied prospectively and two other groups (patients hospitalized for up to 7 days and patients hospitalized for more than 7 days) were compared to one another. We looked for the emergence of tellurite resistance among Enterobacteriaceae using a selective medium, MacConkey potassium tellurite (MCPT). The frequency of prospectively studied patients with tellurite resistant strains was significantly greater after 7 days of hospitalization. For the two other groups, patients with more than 7 days of hospitalization showed a significant increase of bacterial species and of strains with new antimicrobial resistance markers. High molecular weight plasmids were detected in some of these strains. These data show that the MCPT medium is a useful tool for the investigation of bowel colonization in hospitalized patients by drug-resistant Enterobacteriaceae.
Objective: To evaluate the occurrence of intestinal colonization in newborns by multidrug-resistant enterobacteria strains (MDRES) during hospital stay after birth. We used selective media in an attempt to determine the relationship between isolation of these strains and some of the presumed colonization risk factors. Method: A sequencial inclusion study of 30 newborns was carried out in the neonatal unit of the HUPE, State University Hospital, a general 600-bed tertiary care hospital. We obtained clinical and epidemiological information from medical records and collected a fecal sample from each newborn, which was plated in gentamicin (8mg/ml) medium and potassium tellurite (25mg/ml) medium. The isolated strains were biochemically identified and also submitted to tests of antimicrobial susceptibility. Nine MDRES were submitted to an assay for plasmid conjugational transfer. Results: We isolated 56 distinct MDRES from 14 among 30 newborns (46.7%). Klebsiella pneumoniae was the most common bacterial species (38/56 (68%)). We found statistical association between individual MDRES isolation and presence of 3 or 4 of the following colonization risk factors considered: antimicrobial use, low weight (<2.500g), more than 6 days of hospitalization and artificial milk feeding (p< 0.02). We could detect plasmid resistance transfer by bacterial conjugation for 8 among 9 MDRES. Conclusion: The seletive cultura media were useful to detect the high frequence of newborns colonized by MDRES in association with well established infection risk factors. We emphasize the importance of reinforcing control rules aiming at preventing intestinal colonization viewed as a risk of nosocomial infection.
Pulmonary infection on cystic fibrosis (CF) patients are associated with a limited qualitative number of microorganisms. During the colonization process, Staphylococcus aureus usually precedes Pseudomonas aeruginosa. This latter is at first non-mucoid, being replaced or associated to a mucoid morphotype which is rare in other diseases. In 1980, Pseudomonas cepacia appeared as an important agent in CF pulmonary infections with a mean frequency of about 6.1% isolations in different parts of the world. The primus colonization mainly occurs in the presence of pre-existent tissue lesions and the clinical progress of the disease is variable. In some patients it can be fulminant; in others it can cause a gradual and slow decrease in their pulmonary functions. The concern with this germ isolation is justified by its antibiotic multiple resistance and the possibility of direct transmission from a colonized patient to a non-colonized one. We reported the first case of P. cepacia infection in a CF patient in our area. The microbiological attendance to this patient had been made from 1986 to 1991 and the first positive culture appeared in 1988. The sensitivity profile showed that the primus colonization strain was sensitive to 9 of 17 tested antibiotics, however in the last culture the strain was resistant to all antibiotics. These data corroborate the need for monitoring the bacterial flora on CF patients respiratory system.
Admitida uma baixa freqüência de Salmonella com base em verificações anteriores em casos de diarréia aguda na cidade de Araraquara, S. Paulo, realizou-se uma investigação com um esquema ampliado para o isolamento de Salmonella a partir de 47 casos de gastroenterite infantil, 51 amostras de fezes de animais e 50 amostras de carnes e vísceras de animais destinados a alimentação. Foram isoladas Salmonella em 6,3% dos casos de gastroenterite, 5,8% de fezes de animais e 8,0% de amostras de alimentos, nesse último caso verificando-se a contaminação exclusivamente em fígado de porco, senão negativos todos os resultados de carne e vísceras de bovinos. Os sorotipos isolados corresponderam, em ordem decrescente de freqüência a S. anatum, S. derby e S. daytona. Nas gastroenterites infantis a freqüência de Shigella (12,7%) foi duas vezes superior à de Salmonella (6,3%).
Faleceu n a m adrugada de 25 de novem bro próximo passado o Dr. Joaquim T ra vassos da Rosa, o que representa perda ir reparável p ara a Ciência Médica Brasilei ra, pelo m uito que realizou nos seus 69 anos de existência. N atural de Belém do Pará, Estado do P a rá, tornou-se médico, pela então F acul dade de Medicina do Rio de Janeiro, onde iniciou-se no campo da Microbiologia como Monitor e depois Preparador da Cadeira de Microbiologia; vinculou-se a seguir às atividades de Saúde Pública como Médico Bacteriologista da Diretoria de Higiene do Rio Grande do Sul. Nesse período desen volveu investigações sôbre vários aspectos do diagnóstico das infecções bacterianas (lepra, sífilis, m eningites, etc) destacan do-se estudos sôbre a transm issão de agen tes patogênicos pela água e pelo leite, e sô bre a epidemiologia da peste.Transferindo-se para o Institu to B utantã n de São Paulo, em 1929, dcdicou-se a investigações sôbre a Im unidade na escar latin a até voltar-se para o campo da virologia, onde foi um dos principais sustentá-culos da grande obra escrita pela escola paulista no esclarecimento da etiologia, etiopatogenia e epidemiologia das febres maculosas e do tifo exantem ático, estabe lecendo, entre outras contribuições, a iden tidade entre os agentes da Febre Maculosa Brasileira e das M ontanhas Rocho sas nos EUA. Detendo-se ainda sôbre o poder tóxico dos estafilococos, a sua con tribuição é, ainda hoje, citação obrigatória nas melhores publicações sôbre o assunto.Voltando ao Rio de Janeiro, para instalar e organizar a Seção de Riquétsias do Ins tituto Oswaldo Cruz, em outubro de 1948, logo, em um a série de trabalhos memorá veis, revela a presença de tifo m urino nes ta cidade, em quadros que se confundiam com os de febre tifóide, o que, possivelmen te, ainda hoje ocorre, apesar dêsse brado de alerta, extrem am ente claro.Em 1952, passou a ocupar a chefia da Di visão de Vírus do Instituto de Microbiologia
Twenty-four (82.7%) out of 29 patients suffering from hospital acquired urinary infections by Klebsiella pneumoniae had the same species in their faeces. Biotyping of 24 urinary and 219 fecal strains of K. pneumoniae resulted in 50 different biotypes - an average of four biotypes per fecal sample. Ten patients (34.4%) had the same biotype in urine and faeces without any correlation with previous vesical catheterization (p greater than 0.05). Using resistotyping to four chemical compounds selected among 34 tested substances (brilliant green, malachite green, potassium tellurite and mercuric chloride) 16 different resistotypes were found. Fourteen patients (58.3%) presented the same resistotype in urine and faeces but only in five patients was there correlation with simultaneous biotyping identity. Simultaneous occurrence of identical biotypes or resistotypes in faeces and urine occurred in only 54.2% of cases. However, there was a significant association between resistance ot mercuric and tellurite ions in fecal and urinary strains isolated from the same patient (p less than 0.001).
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