O objetivo deste trabalho foi detectar em 101 amostras de E. coli isoladas de bezerros com e sem diarreia, fatores de virulência associados aos patotipos de E. coli enterotoxigênica e enterohemorrágica. Os fatores de virulência de E. coli Stx1 (Shiga toxina), Stx2, Ehly (Enterohemolisina), o gene eae, LT-II (enterotoxina termo-lábil), STa (toxina termo-estável), e adesinas K99 e F41 foram detectados por PCR. Os sorogrupos foram determinados por métodos sorológicos e a produção de Stx foi observada através de ensaios biológicos em células Vero. A frequência de detecção do gene eae foi maior nos isolados de bezerros com diarreia (35/58, 60,3%) do que em bezerros saudáveis (8/43, 18,6%; P < 0.001). O gene da toxina Stx1 foi detectado em alta frequência em amostras diarreicas (24/58, 40,3%), bem como em amostras não diarréicas (19/43, 44,2%) e todas as amostras positivas para toxina Stx em PCR mostraram citotoxicidade em células Vero. Stx2 foi encontrada em dez amostras, Ehly em oito amostras, e LT-II em duas amostras. Vinte e seis amostras foram negativas para todos os ensaios de PCR, incluindo para as adesinas F41 e K99. Os sorogrupos O7, O23, O4, O8, O153 e O156 foram detectados com maior frequência. O trabalho mostra que amostras de E. coli isoladas de bovinos apresentam fatores de virulência semelhantes à isolados de casos de doenças em humanos e possivelmente é uma fonte para STEC potencialmente patogênicas para humanos.

The aim of this work was to test 101 strains of E. coli for virulence factors associated with enterotoxigenic and enterohemorrhagic pathotypes of E. coli isolated from diarrheic and non-diarrheic calves. The virulence factors of E. coli Stx1 (Shiga toxin), Stx2, Ehly (Enterohemolysin), the eae gene, LT-II (heat-labile enterotoxin), STa (heat-stable toxin), and adhesins K99 and F41 were detected by PCR. Serogroups were determined by serological methods and Stx production was observed by biological assays in Vero cells. The frequency of the eae gene was higher in isolates from diarrheic calves (35/58, 60.3%) than in non-diarrheic calves (8/43, 18.6%; P < 0.001). The gene for Stx1 occurred at high frequencies in the diarrheic strains (24/58, 41.3%) as well as in non-diarrheic (19/43, 44.2%) ones and all strains that were Stx positive by PCR showed cytotoxicity in Vero cells. Stx2 was found in ten strains, Ehly in eight strains, and LT-II in only two strains. Twenty-eight strains were negative for all of the PCR assays, including for F41 and K99 adhesins. The serogroups O7, O23, O4, O8, O153 and O156 were observed most frequently. Our results show that strains of E. coli isolated from cattle have similar virulence factors genes to strains isolated from cases of diseases in humans and may be a source of potentially pathogenic STEC for humans.

Neste trabalho apresentamos resultados da análise de perfis verticais, obtidos simultaneamente, das emissões OI 557,7 nm, banda (0-0) do sistema O2 atmosférico e sistema O2 Herzberg I, em termos dos processos de formação e perda dos estados O(¹S), O2(b¹sigmag+ ) e O2(A³sigmau+ ). Os perfis de emissão foram obtidos via fotômetros instalados a bordo de um foguete lançado de Alcântara (2(0)S, 44(0)O) em 31 de maio de 1992, às 23:52 (LT). A carga útil continha 6 fotômetros dispostos paralelos ao eixo do foguete para medir a taxa de emissão volumétrica das linhas OI 557,7 nm e NaD (589 nm), da banda (0-0) do sistema O2 atmosférico, do sistema O2 Herzberg I (275 nm) e do contínuo a 578 nm e 4 fotômetros dispostos transversalmente, em um ângulo de 90(0), para medir a taxa de emissão volumétrica das linhas OI630 nm e NaD (589 nm), da banda OH(8-3) e do contínuo a 710 nm. Nossos resultados, no caso dos estados O(¹S) e O2(b¹sigmag+ ), sugerem a validade, também para região equatorial, de parâmetros derivados de experimentos em latitudes altas. No caso do estado O2(A³sigmau+ ), nossos resultados sugerem coeficientes de perda por colisões com O2 e/ou N2 maiores que os anteriormente propostos com base em dados aeronômicos, mas em acordo com resultados recentes de laboratório.

Simultaneous measurements of the nightglow profiles of the O2 Herzberg I bands, the O2 atmospheric (0-0) band and the OI 557.7 nm line are discussed in terms of the excitation and loss of the O(¹S), O2(b¹sigmag+ ) and O2(A³sigmau+ ) states. The measurements were carried out by rocket-borne photometers launched from Alcântara (2(0)S, 44(0)W) on May 31, 1992 at 23:52 LT. The rocket payload contained 6 longitudinal photometers to measure the OI 557,7 nm and NaD 589 nm lines, the O2 atmospheric (0-0) and Herzberg I bands and the continuum at 578 nm, together with 4 transverse photometers measuring the OI 630 nm and NaD 589 nm lines, the OH(8-3) band and the continuum at 710 nm. The results for the O(¹S) and O2(b¹sigmag+ ) states suggest the validity for the equatorial region of empirical parameters derived from measurements made at high latitudes. For the O2(A³sigmau+ ) states, the quenching rates required to explain the measurements are higher than the values derived from previous airglow measurements but in agreement with recent laboratory measurements.

The observations made about the stomach of Trichogenes longipinnis (Britski & Ortega, 1983) showed a rounded organ which has in its dorsal side an accessory structure - a cul de sac - that comunicates with it. The distal part of this dorsal accessory presents characteristic of an organ that exercise respiratory functions: reduction in the thickness of the mucosa and arrangement of an intrincate continuous capilar net in close contact with the superficial cells of the epithelium. In this portion there are no glands in the lamina propria. The epithelium shows a superficial squamous cels; they are very slim, and sometimes, with the capillary endothelium form a single barrier between the organ lumen and the blood. Polyhedric cells are also present in this epithelium; they are located under the squamous cells, sheltered between capillaries and basal cells.

Trichogenes longipinnis (Britski & Ortega, 1983) is a leather fish restricted to the rivers on the shore in the southeast of Brazil. In this work, the oesophagous structure is being showed. The oesophagous appears itself short, dorsally inclinated toward pericardium and ventrally covered by liver lobe. By electron microscopy we can observe a mucosa layer formed by stratified squamous epithelium and lamina propria with stratum compactum. The epithelium is composed by three types of cells: superficial squamous cells; mucous cells, similar to the globet cells and polyhedric cells. The stratification of this epithelium provides a complete basal layer of proliferation polyhedric cells. The cells in the intermediate region of the epithelium are also polyhedric. These cells are just bellow the superficial squamous cells and packed among mucous cells.