Acta microbiologica Hungarica最新文献

Enterohaemolysin production was found in 11 (20.3%) out of 54 Escherichia coli strains isolated from stools of infants with dyspepsia and in 3 (2.3%) out of 130 E. coli strains isolated from urinary tract infections. Enterohaemolysin producing E. coli strains isolated from stools belonged to O groups 25 and 111 and the strains from urine to O groups 1 and 15. None of the enterohaemolysin-producing strains isolated from dyspepsia was shown to cause any damage on Vero cells.

Mild infection or sublethal dose of endotoxin elicits a brief elevation of GH and PRL in the serum. These hormones have proinflammatory and immunostimulatory effect. In severe trauma, sepsis and shock, GH and PRL are suppressed, whereas glucocorticoids and catecholamines are elevated. Under these conditions an acute phase response is initiated by tissue derived (cytokine) hormones, namely IL-1, IL-6, TNF alpha, and several others, which elicit a neuroendocrine response and initiate major metabolic alterations. There is fever and catabolism prevails, whereas the synthesis of acute phase proteins in the liver, cell proliferation in the bone marrow, and protein synthesis by leukocytes is elevated. This is an emergency reaction to save the organism after the local immune/inflammatory response has failed to contain and eliminate the infectious agent. During sepsis and endotoxin shock the systemic activation of the complement system and of leukocytes releasing enzymes and highly toxic cytokines seriously threaten survival. Glucocorticoids suppress proinflammatory cytokine production and potentiate the secretion of acute phase proteins. Some of these proteins, such as C reactive protein, or LPS binding protein, are designed to combine with microorganisms and trigger their destruction by the activation of complement system and of phagocytes. The increased production of some complement components also helps host resistance. The rise in serum fibrinogen promotes blood clotting which can serve to isolate the invading agent by triggering thrombosis in infected tissues. A number of enzyme inhibitors are produced as acute phase proteins, which are likely to serve to curb the nonspecific damage inflicted by enzymes released from activated phagocytes and from damaged cells into the circulation during sepsis and shock. Catecholamines are also elevated, which serve to inhibit inflammatory responses and to promote, even initiate, the acute phase response. If the acute phase reaction fails to protect the host, shock will develop. Patients with subclinical adrenal insufficiency succumb to septic shock almost invariably if glucocorticoid therapy is not given. However, glucocorticoid treatment of septic patients with normal adrenal function has not been helpful. The use of antibiotics to control infection did not lead to spectacular success either because of the emergence of resistant bacterial strains or the enhanced release of endotoxin by this therapy. The new approaches to prevent and treat septic shock involve the use of antibodies capable of neutralizing LPS and of cytokines and the inhibition of cytokine action by antagonist agents.

The antibiotic resistance of 6 Staphylococcus aureus strains was eliminated with a frequency from 1.2 to 10% in the presence of subinhibitory concentrations of promethazine. The pigment production of the cells was also eliminated by the promethazine to an extent of 0 to 5%. The cell size was increased and the protein A production was markedly decreased in S. aureus cells cultured in the presence of promethazine. Complex formation between protein A and promethazine was detected by differential spectrophotometry. The biological activity of staphylococcus protein A was abolished by promethazine in the passive haemagglutination of rabbit antiserum treated sheep red blood cells. Evidence has been found that plasmid-encoded functions of S. aureus cells can be altered in the presence of promethazine, and the chromosomally controlled synthesis of protein A, one of the weakest virulence factor of S. aureus is also lowered by promethazine.

Cell and serum samples from 7 Hungarian patients with mycosis fungoides were examined for the presence of HTLV-I-related DNA sequences and antibodies recognizing HTLV-I antigens. DNA sequences distantly related to the proviral DNA of HTLV-I were shown by Southern blot hybridization in 3 patients. Serum samples from these patients contained antibodies reactive with the internal core polypeptides of HTLV-I and HTLV-II, but not with the env gene encoded type-specific HTLV antigens. Restriction enzyme analysis with EcoRI, PstI, BamHI and SacI revealed structural similarity of the provirus(es) integrated in the DNA of mycosis fungoides cells to HTLV-I but not to HTLV-II. Data suggest that these proviruses and HTLV-I are similar to each other along gag and pol regions.

The senior author was the recipient of a contract (1-CP3-3292) from the National Cancer Institute, USA (NCI) in the early 1970s. The aim of NCI's targeted research program was the establishment of a tumour-specific human lymphocyte-mediated cytotoxicity assay. Neither lymphocyte growth factors nor monoclonal antibodies for lymphocyte typing were available. Tumour-specific populations of lymphocytes could not be maintained but their presence in ficoll-hypaque preparations of blood buffy coats or in primary cultures of tumours was clearly recognized. Another indiscriminately cytotoxic population of lymphocytes had usually overridden the tumour-specific population. In contradistinction to the ruling doctrine of the era, indiscriminately cytotoxic lymphocytes were readily found in the blood of tumour-bearing patients and healthy individuals (the senior author's lymphocytes were shown to practice indiscriminate cytotoxicity in 1971, an observation first interpreted as "immune surveillance at work" in an individual daily exposed to patients with metastatic cancers). Instead of converting the subject matter of the contract from a tumour-specific to a non-specific cytotoxicity assay, the NCI prematurely "phased it out" (but continued the project as intramural research). Nevertheless, many functions of cytotoxic lymphocytes that had become by now well established were foreshadowed during the early 1970s with the limited support of that NCI contract and funds from other sources. Here we recount those early observations; present the outlines of adoptive immunotherapy with various autologous lymphocyte populations and in a separate report in this volume give a technical description how these lymphocyte populations are prepared in the laboratory for therapeutic reinfusions into the patient.

Palmitic acid and palmitates were transformed into water soluble complexes with crystalline heptakis-2,6-di-0-methyl-beta-cyclodextrin. This formulation was incorporated into liquid and solid chemically well-defined media. The fatty acid served as C and energy source, ammonium thioglycolate as the sole source of N with the SH group as further source of energy. Minute amount of dimethyl-sulfoxide added was used for its known effect on cell membrane permeability. The media were inoculated with host grown Mycobacterium leprae cells isolated from human, armadillo and Nu mice foot pad lepromata. No growth occurred in the liquid medium at 22 or 32 degrees C, but cultures and subcultures of acid fast rods were grown at 10 degrees C. Bacilli in the cultures were solid, strongly acid fast rods, growing in clumps like globi. Growth on the semisolid media was visible as smooth round colonies, of white to ivory in colour, slowly expanding flatly at the periphery of the colony on the agar surface. Colonies developed within 2-3 weeks and reached maximum size at 50-80 days depending on the size of inoculum. Subcultures grow faster and more abundantly with adaptation to the media. No growth was seen without the water soluble complexes of palmitic acid or palmitates in the media. The free fatty acid or its salts had an equal growth supporting effect. Identical psychrophilic cultures were obtained from 7 out of 9 armadillo, 12 out of 12 Nu mice and 1 out of 2 human lepromata. None of the cultures grow on Loewenstein, Dubos or 7H9 media at 10 degrees C, 20 degrees C or 32 degrees C, respectively. The tested 4th to 7th subcultures of the strains were strongly positive for phenolic glycolipid-1. Heat killed suspensions of up to 7th subcultures gave negative late skin reaction in all of 16 LL cases. In 19 I, B and T cases the late skin reactions were all similar to that obtained with authentic human lepromin.

Based on a twenty-year experience, a simple identification system for slowly growing mycobacteria has been presented for clinical laboratories not specialized in this work. With this system (12 tests: tolerance to 0.02% picric acid, colony pigmentation in the dark, nitrate reduction, resistance to ethambutol, tween hydrolysis at 7 and 14 days, resistance to hydroxylamine, PAS degradation, tolerance to p-nitrobenzoic acid, production of nicotinic acid and colony morphology) we have identified 15 strains of Mycobacterium gordonae and 10 of Mycobacterium avium-intracellulare complex, isolated from surface water in Valencia, Spain.

The prevalence of genital human papillomavirus (HPV) infection in Hungarian female populations is not essentially different from that found in other countries of Europe and North-America. Using filter in situ hybridization (FISH), we found that, in a group of cytologically normal women some low risk HPV types (such as HPV 6 and 11) and the most important high risk HPV types (HPV 16 and 18) were present in 23% and 8%, respectively. Eighty-eight percent of condyloma acuminatum patients harboured HPV 6 or HPV 11 in their tumours. On the other hand, in precancerous lesions (cervical intraepithelial neoplasia, CIN) HPV 16 was the predominant type, being present in 29-48% of patients, depending on the detection method used (Southern blot hybridization vs. polymerase chain reaction). The detection rate of high risk HPV types was found to rise with the increasing severity of cervical neoplasia. Finally, 48% of invasive cervical carcinoma specimens were positive for HPV 16 DNA in a type-specific polymerase chain reaction. For patients with HPV 16 positive primary tumours, all but one lymph node metastases and about 30% of histologically normal lymph nodes proved positive for HPV 16 DNA. Our results--in accordance with the numerous data found in literature--seem to confirm the hypothesis that certain HPV types are greatly involved in the development of cervical cancer.

Sera of 40 intravenous drug addicts were tested for the presence of cytotoxic antibodies against uninfected and HIV-infected monocytic U937 cells. Twelve out of 31 seropositive samples proved to be cytotoxic for HIV-infected, untreated target cells in the presence of complement. The TNF-alpha treatment of HIV-infected U937 cells increased the detectability of cytotoxic effect of sera (21/31). The complement dependent cytotoxic activity of sera was reduced by pretreatment with recombinant HIV gp120. This reduction proved to be dose-dependent in the majority of cases. Immunofluorescence studies indicated that the cytotoxic sera interacted with antigens mostly localized on the cell membrane of HIV-infected TNF-alpha treated U937 cells. The specificity, the possible role and origin of monocytotoxic antibodies in HIV-infected persons is discussed.