Acta microbiologica Hungarica最新文献

Growth properties of coagulase-negative staphylococci in the presence and in the absence of human and rabbit serum in soft-agar prepared in modified Staphylococcus 110 broth were studied. The adherent growth was examined in modified Staphylococcus 110 broth and 1% glucose-meat broth. Of 100 strains examined 69% exhibited diffuse, 18% compact, 7% transient and 6% mixed growth. Compact type colonies were mainly characteristic of Staphylococcus haemolyticus strains. The presence of serum failed to influence the types of colony morphology in any of the strains. Sixty-three percent of the strains showed adherent growth; none of the S. haemolyticus strains produced adherent growth. The glucose-meat broth, unlike modified Staphylococcus 110 broth, was suitable to study adherence. The coincidence of the compact colony morphology in soft-agar and the absence of adherent growth seems to be a taxonomic sign for the species S. haemolyticus and differentiate it from the species Staphylococcus epidermidis.

Mefloquine, an antimalarial, was tested against several bacteria and a yeast. It has moderate activity against Staphylococcus aureus, Staphylococcus saprophyticus and Escherichia coli and no measured activity against Pseudomonas aeruginosa and Candida albicans.

Adenoviruses produce a variety of serious diseases in people of all ages. The mode of transmission of adenovirus infections includes respiratory, fomite, droplet, venereal, and faecal-oral routes. They have been shown to spread with ease in AIDS patients, in young children and in hospitalized patients. A constant rate of about 8% of world-wide reported virus infections were observed to be due to adenovirus infections. In the military, it can cause serious respiratory disease (ARD) of epidemic proportion in new recruits. The present commercial vaccine is prepared in unique triple-layered tablets containing live lyophilized virus. This vaccine has been taken by more than ten million subjects during the past 25 years with no adverse reaction and with near total eradication of ARD epidemics among new recruits at training centers. As the epidemiology of adenovirus diseases becomes more clearly defined, the need for and the possible role of potential vaccines, is becoming more evident.

In Hungary, uniform methods and quality assessment date back as early as 1927, when the National Institute of Hygiene and regional public health laboratories were established. The National Microbiology Committee organized in 1984 was replaced in 1992 by the National Clinical Microbiology Board and the Joint Quality Assurance Committee of Clinical Microbiology for which the National Institute of Hygiene acts as an operating centre. A long-range programme of proficiency testing and on-site inspections had a beneficial effect on performance in public health laboratories: in 1989 20 out of 24 of them were scored in the excellent or good degree. Hospital laboratories, which joined this programme only in 1984, exhibited less satisfactory results.

An attempt has been made to detect the minimum counts of enterotoxigenic Escherichia coli (ETEC) in stool sample under simulated clinical condition. Thermostable (ST-la) enterotoxin-producing ETEC culture was mixed with stool sample and normal saline, centrifuged, then the supernatant was further diluted with saline and different volumes were spotted on nitrocellulose paper. Hybridization with 32P labelled pDAS-101 DNA and viable count of original culture on MacConkey agar plates with ampicillin revealed that minimum 8 cells of ETEC (ST) could be detected. The method of labelling used was sequential harnessing of the catalytic and synthetic activity of the large Klenow fragment of DNA polymerase-I. Linearizing of the DNA was dispensed with as the nicked circular DNA was excised with the gel and used for labelling directly.

Immunoprophylactic and immunotherapeutic effects of specific actinobacillus DLE (dialysable leukocyte extract) were studied in model pigs experimentally infected with Actinobacillus pleuropneumoniae. Specific DLE used for immunoprophylactic purposes was administered intramuscularly to pigs either in two doses in combination with one dose of actinobacillus vaccine (1st group) or in a single dose (2nd group). All animals of the two experimental groups survived the intranasal A. pleuropneumoniae challenge (2 x 2 ml 2-5 x 10(10) c.f.u.) while 3 of 5 animals of the control group died of haemorrhagic-necrotic fibrinous pneumonia. DLE administered to pigs for immunotherapeutic purposes was applied intravenously in two doses 1 and 5 h after the actinobacillus challenge (1st group), and in a single dose 5 h following the challenge (2nd group). All animals of the first group survived the challenge while 3 out of 5 animals of the second group and 4 out of 5 animals of the control group died during the experiment.

Twenty-three strains belonging to classic enteropathogenic Escherichia coli (EPEC) serogroups were investigated for the production of heat-labile (LT) and heat-stable (STa) enterotoxins, verotoxins (VT), cytotoxic necrotizing factors CNF1 and CNF2, alpha-haemolysin (Hly), necrosis and modification of permeability in rabbit skin, lethal activity to mice, mannose-resistant (MRHA) and mannose-sensitive (MSHA) haemagglutination, relative cell surface hydrophobicity and the expression of P fimbriae. Of 23 EPEC strains, 7 (30%) belonging to serotypes O18ac: H7 (Hly+), O20: H26 (lethal), O26: H- (Hly+), O44: H18 (Hly+), O55: H- (CNF2+, necrotic and lethal), O119: H27 (VT+ and Hly+) and O142: H6 (lethal) produced toxic factors. Seven (30%) of 23 EPEC strains were MRHA+, 17 (74%) were MSHA+ and only 2 possessed high hydrophobicity. Two strains belonging to serotypes O18ac: H7 and O44: H18 that showed MRHA type IVa were fimbriated when grown on CFA medium.

Latex particles were coated with different monoclonal antibodies (MAbs) reacting with different epitopes of the hexons of adenovirus (AV) type h1 and h35. The coated particles were tested with the purified hexon of 22 different mammalian AV types and were agglutinated by the respective hexon antigen(s) with high specificity. The sensitivity of the reaction was influenced by the amount of MAb adsorbed to latex particles. The latex, coated with a MAb of genus specific reactivity can be a valuable tool in the rapid immunodiagnosis of adenovirus infections.

Tricyclic compounds were able to inhibit the motility of Proteus vulgaris. The effectiveness of antimotility action was related to the physicochemical properties of the molecules, i.e. energy of HOMO, Log P, total surface. The antimotility action of the compounds was due to their reversible inhibition on the proton pump of the bacterium. Phosphate anion antagonized the antimotility, and potassium cation enhanced the action of phosphate anion on the antimotility effect induced by the agents. Glucose reversed the antimotility action of the compounds. Factors directly increasing the bacterial proton-motive force (PMF) could change bacterial motility and the antimotility action of the tricyclic compounds.