TEACHING OF MEDICAL MICROBIOLOGY - COMMENTS ON BASIC VERSUS APPLIED ASPECTS RELATED TO PROFESSION

Comments about education and medicine teaching were made. The learning and the curriculum in according with the priorities of the country's health had special emphasis.Students and teachers of Botucatu considered that the improvement of the 2nd year medical microbiological course was good with predominantly basic contents. The students prefer a balanced content or predominantly applied to medicine.Three phases of the teaching of microbiological contents are proposed: 1st - in the basic cycly (2nd year); 2nd - into the course of Clinical Laboratory (3rd or 4th year); 3rd - into the clinical cycle, following a program of integration.

EVALUATION OF DIFFERENT TECHNIQUES FOR THE DIFFERENTIATION OF PATHOGENIC AND NON PATHOGENIC STRAINS OF YERSINIA-ENTEROCOLITICA

Different methods and tests have been used to evaluate the pathogenic potential of distinct Y. enterocolitica serotypes and biotypes. We tested a total of 60 Y. enterocolitica strains, being 25 of human origin (serotype O3 biotype 4 and serotype O5 biotype 1); 6 of animal origin (serotype O3 biotype 4); 19 isolated from the environment (serotype O5.27 biotypes 1 and 2); and 8 isolated from food (serotype O5 biotype 1 and serotype 05.27 biotype 1). The methods used were based on plasmid gene expression (autoagglutination, calcium-dependence at 37 degrees C and Congo Red absorption tests), chromosomal gene expression (assays for pyrazinamidase activity, salicin fermentation and esculin hydrolysis), and invasion of HEp-2 cells. All but one of the Y. enterocolitica O3 strains, were found to be potentially pathogenic when submitted to the pyrazinamidase-salicin-esculin tests. In contrast, the results obtained with the assays related to plasmidial gene expression were not so uniform, probably due to plasmid loss. The least homogeneous results were obtained with the HEp-2 cell invasion test. Y. enterocolitica O5 behaved in a uniform manner when tested with the first two groups of tests (based on chromosomal and plasmidial gene expression), but not when tested with the HEp-2 invasion assay. The strains of serotype O5.27 biotype 1 presented a uniform behavior hen submitted to the chromosomic-related tests, showing no pathogenicity. However, they did not provide conclusive results with the tests related to plasmidial gene expression or HEp-2 cell invasion. We conclude that the tests related to chromosomal gene expression (esculin-salicin-pyrazinamidase) are simple and highly effective for the detection of potentially pathogenic Y. enterocolitica isolated from clinical cases.

ENTEROTOXIN PRODUCTION IN STRAINS OF CAMPYLOBACTER-JEJUNI, ISOLATED FROM SWINE DIARRHEA

One hundred and twenty-six strains of Campylobacter jejuni isolated from swine with diarrhea were examined for the production of enteroxin, by culture filtrate inoculation into ileal loops in several animal species.Four (3,1 %) of the strains tested produced fluid in ligated ileal loop of albino rabbit, 19 (15 %) in rat and 14(11, 1 %) in swine. By the test of intragastric inoculation in suckling mouse, none of the strains revealed capacity to produce enterotoxin, although two strains were considered suspicious. Twelve (54,5 %) of the strains that induced ileal fluid in rat and swine produced cytotoxic effect in monkey kidney cells (Vero), affecting up to 60 % of the monolayer. However, no alteration was observed in hamster kidney cells (BHK).

INCIDENCE OF MYCOBACTERIUM-TUBERCULOSIS AND OTHER MYCOBACTERIA ON PULMONARY INFECTIONS IN ARARAQUARA - SP, 1993

The incidence of tuberculosis and other infections by mycobacteria was analyzed in 559 patients admitted to the Tisiology Section of the Special Health Care Unit of Araraquara (SESA). Mycobacteria were isolated from 78 individuals out of this total. Among these patients, 15 were also HIV positive. The occurrence of isolated species was: M. tuberculosis: 69 patients; M. avium-intracellulare: 5 patients; M. fortuitum: 2 patients; M. chelonae: 1 patient; and M. simiae 1 patient. The latter was for the first time isolated from humans in Brazil. In most cases, non tubercular mycobacteria (NTM) were found in the HIV positive patients.

First-void versus midstream urine culture for detection of Ureaplasma urealyticum in the urinary tract

Quantitative Ureaplasma urealyticum culture was performed on clean first-void and midstream urine to evaluate the presence of these mollicutes in the urinary tract. The results, expressed as color changing units (CCU), showed that 14 (63%) of the 22 Ureaplasma urealyticum positive patients yielded counts equal to or higher that 10(7) CCU/mL for both the initial and the middle urine specimens. No abnormal chemical or microscopic findings (protein content, leukocyte numbers) were observed. The occurrence of U. urealyticum in midstream urine samples, even when numbers are considered, may be no more than a guide to the presence of ureaplasmas in the urinary tract.

Isolation of Campylobacter jejuni from viscera and bile secretion of broiler chickens with diarrhea

Since chickens are important reservoirs of Campylobacter jejuni and their meat is the most frequent route of transmission for human campylobacteriosis, the purpouse of the present study was to investigate the presence of Campylobacter in viscera of chickens with diarrhea, evaluating the frequency of isolation of this microorganism from organs considered to be preferential for its isolation. A total of 107 visceral samples from chickens with diarrhea from different farms in the Ribeirao Preto region, SP, were examined for the presence of Campylobacter jejuni. The material consisted of 73 livers and 34 spleens, plus 29 bile secretion samples. The frequency of Campylobacter jejuni isolation was 54.79% for the liver samples, 35,29% for the spleens and 6,89% for the bile secretion samples. The data suggest that, under the conditions of the present study, the liver may be the organ of choice for the isolation of Campylobacter in the presence of diarrhea and liver involvement in chickens.

Curtobacterium flaccumfaciens pv. Flaccumfaciens detection in bean seeds using a semi-selective culture medium

The bacterial wilt caused by Curtobacterium flaccumfaciens pv. flaccumfaciens is currently considered one of the most important bacterial bean disease in Brazil. One of the most effective control methods against this disease is the use of healthy seeds. However, no methods are known that could be routinely used to detect this bacterium in bean seeds under Brazilian condition. The aim of this work was to evaluate qualitative and quantitative detection methods for Curtobacterium flaccumfaciens pv. flaccumfaciens in naturally-infected bean seeds, and the detection of this pathogen in thirty bean seed samples, by sowing onto a semi- selective culture medium the leachate obtained from soaked bean seeds. Both the qualitative and quantitative methods were effective for detecting the presence of the bacteria in the seeds samples analysed. The qualitative method proved more practical for rotine use; of the thirty bean seed samples analyzed by this method, fifty percent were infected with Curtobacterium flaccumfaciens pv. flaccumfaciens.

Staphylococcus aureus: Resistance patterns to antimicrobials and Penicillinase among strains isolated from apparently healthy lactating cows

Ninety-two strains of Staphylococcus aureus isolated from the nasal fossa and udder skin of apparently healthy lactating cows were analyzed for resistance to antibiotics and production of penicillinase.The results showed a greater frequency of resistance patterns to penicillin and ampicillin.All strains were sensitive to oxacyllin and gentamicin.The most frequent Barber and Burston model was SSSS (60.90%), followed by RSSS (18.50%).With respect to the production of penicillinase although the Lucas method indicated a larger number of positive samples, we suggest the use of the Haight and Finland method due to a greater consistency of data obtained with it.