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Biomedical subjects

R Lannigan

Publications and source records attributed to R Lannigan.

At least 37 records · Page 2Linked to original sources
PubMed1987

Comparison of susceptibility results of anaerobic organisms determined by agar dilution method and Sceptor Anaerobe MIC/ID Micro Broth Dilution Panels.

A commercial broth microdilution system (Sceptor Anaerobe MIC/ID, BBL) for susceptibility testing of anaerobic bacteria was compared to a reference agar dilution system. Of the 172 organisms tested, only 7% failed to grow sufficiently for testing in the Sceptor system. In 1,590 antibiotic/organism combinations, 86.7% of the Sceptor results were identical or within one doubling dilution of the reference system. In 91.9% of the cases, interpretation of the results was same in both systems. Two hundred and twelve MIC values, however, differ by greater than or equal to 2 log2 dilution from the reference system. Due to this reduced correlation in the actual MIC values with the reference results, further studies are warranted before the Sceptor system can be recommended for routine use.

Agar↗
PubMed1987

Supplement peptone agar--a simple carbohydrate degradation plate medium for the identification of Neisseria species.

A carbohydrate degradation medium was developed for the detection of acid production by Neisseria species and Branhamella catarrhalis. A total of 223 clinical isolates were identified by Supplemented Peptone Agar and the results were compared with those of Cystine Trypticase Agar. Supplemented Peptone Agar and Cystine Trypticase Agar correctly identified 99.1% and 93.7% of the total strains respectively within 24 h. With Cystine Trypticase Agar method another 4% of the isolates could be identified but required an additional 24 h of incubation.

Culture Media↗
PubMed1987

Endophthalmitis due to Oerskovia xanthineolytica.

Unilateral endophthalmitis developed in a 47-year-old man following an intraocular eye injury with a metallic foreign body. Eventually, Oerskovia xanthineolytica was isolated from the vitreous humour. To our knowledge this is the first documented case of endophthalmitis caused by this organism in humans. The clinical course and management of this opportunistic infection are discussed.

Bacterial Infections↗
PubMed1986

Comparison of the MicroScan system with the API Staph-Ident system for species identification of coagulase-negative staphylococci.

To evaluate the accuracy of the MicroScan System (American Hospital Supply Corp., Sacramento, Calif.) for identification of coagulase-negative staphylococci, we tested 175 clinical isolates of coagulase-negative staphylococci. The results obtained by the MicroScan system were compared with those of the API Staph-Ident system (Analytab Products, Plainview, N.Y.). Forty-three discrepancies between the two systems were resolved by the conventional method of Kloos and Schleifer (W.E. Kloos and K.H. Schleifer, J. Clin. Microbiol. 1:82-88, 1975). The MicroScan and the Staph-Ident systems correctly identified 146 (86.4%) and 154 (88%) of 175 strains, respectively. The API system failed to identify phosphatase-negative Staphylococcus epidermidis. The MicroScan system demonstrated the greatest accuracy in the identification of S. epidermidis and S. saprophyticus, whereas lesser accuracy was achieved with S. hominis, S. warneri, and S. sciuri.

Bacteriological Techniques↗
PubMed1986

Effect of cationic proteins on the glomerular deposition of anionic proteins and immune complexes.

When 3 mg of cationized human IgG (cIgG, pI greater than 9) was injected intravenously into mice and followed 15 min later by 3 mg anionized bovine serum albumin (aBSA, pI = 4), deposits were detected along the capillary loops and in the mesangium. Additional infusion of immunoaffinity-purified rabbit anti-BSA antibodies 1 h later led to their deposition at the same location. Intravenous injection of an equivalent amount of preformed BSA-anti-BSA or aBSA-anti-BSA immune complexes into mice with glomerular planted cIgG gave rise to few deposits. Similarly, the perfusion of preformed aBSA-anti-BSA complexes in isolated rat kidneys with planted cIgG led to granular deposition of both, but the intensity of staining was less than when sequential perfusions were used. Cationic macromolecules bound to the glomerulus may lead to the deposition of anionic macromolecules and anionic immune complexes.

Animals↗
PubMed1986

Stimulation of circulating autoantibody levels in the rat with established progressive passive Heymann nephritis.

Rats with established progressive passive Heymann nephritis (PPHN) were stimulated with tubular nephritogenic antigen derived from rat kidney fraction 3 (rKF3) or heterologous antibody to the eKF3 antigen. Rats stimulated with antigen had elevated levels of circulating autoantibody and increased amounts of rat IgG in a beaded pattern around the glomerular capillaries. The brush border (BB) region of the proximal convoluted tubules also stained for rat IgG. Rats stimulated with antibody had similar changes, but in addition the injected antibody was demonstrated in the glomerular deposits and in the BB region of the proximal convoluted tubules. Proteinuria was markedly increased in the antibody injected rats. This study indicates that the cells of the 'primed' immune system of rats with PPHN can be stimulated by 'additional' rKF3 antigen or antibody to it, to produce increased levels of circulating autoantibody. It is suggested that the progression of PPHN is dependent on the availability and access of the nephritogenic autoantigen to the immune system and that autoantigen may be released by autoantibody.

Animals↗
PubMed1986

Passive Heymann nephritis in pre- and post-natal rats.

Passive Heymann nephritis (PHN) was induced in pre- and post-natal rats by a single intra-peritoneal injection of 0.2 ml of a rabbit anti-rat kidney fraction 3 (rKF3) antibody. Immune complex formation occurred only in those glomeruli or parts of glomeruli which were open to the circulation. Double staining of kidney sections for the glomerular nephritogenic antigen and rabbit IgG, 2 days after the injection of the antibody showed an identical distribution of both components in the glomeruli. In rats killed more than 4 days after the injection of the anti-rKF3 antibody, the nephritogenic antigen could be demonstrated in the subcapsular glomeruli, in the absence of rabbit IgG; and the same applied when the kidneys had reached maturity. When the injected antibody was expected to be present in the circulation, no nephritogenic antigen was demonstrated in the glomeruli in the absence of the heterologous IgG. These observations indicate that the nephritogenic antigen appears in the glomerulus at the same time as the glomerular capillary loops open to the circulation. Unlike PHN in the adult rat, the immune complexes in the glomeruli of neonatal rats do not persist longer than 84 days.

Aging↗
PubMed1985

Streptococcus pyogenes as a cause of nosocomial infection in a critical care unit.

A cluster of five cases of Streptococcus pyogenes infection or colonization was identified in an adult critical care unit following the admission of a patient with a severe cutaneous infection. This report deals with the nature of the outbreak and methods of control, and comments on infections of this nature in adult critical care areas.

Adult↗
PubMed1985

Decreased susceptibility of Serratia marcescens to chlorhexidine related to the inner membrane.

An isolate of Serratia marcescens (strain 100) obtained from a handwashing solution of chlorhexidine (Hibitane) was found not to release potassium ions when exposed to chlorhexidine as compared to chlorhexidine susceptible clinical isolates of Escherichia coli and Ser. marcescens. Lysozyme-tris-EDTA spheroplast preparations of the Serratia isolates were also tested for potassium ion leakage following exposure to chlorhexidine and it was found that the inner membrane was responsible for the decreased susceptibility of the organism of chlorhexidine. These experiments suggested that the mechanism of increased resistance of strain 100 Ser. marcescens to chlorhexidine was an inner membrane change. The nature of the change is currently unknown.

Cell Membrane↗
PubMed1985

Efficacy of tetroxoprim/sulphadiazine in the treatment of Pneumocystis carinii pneumonitis in rats.

Pneumocystis carinii pneumonitis was induced using dexamethasone in male Sprague-Dawley rats. After the first death due to Pn. carinii occurred, nine rats received 50 mg/kg/day tetroxoprim and 120 mg/kg/day sulphadiazine. Four additional rats were given no therapy and served as a positive control. All the surviving rats including five negative controls were sacrificed four weeks after the last positive control rat died. All four rats in the positive control group and two of nine in the treated group developed Pn. carinii pneumonitis, whereas none of the five negative controls had evidence of Pn. carinii infection. The difference between the treated and untreated rats was significant (P = 0.05). These results suggest that combination therapy with tetroxoprim/sulphadiazine is effective in the treatment of Pn. carinii pneumonitis in this animal model.

Animals↗
PubMed1985

Adaptation of a coculture technique to the Minitek anaerobe system.

A method to produce anaerobic conditions by coculture with a nonfermentative organism was utilized in conjunction with the Minitek anaerobe system (BBL Microbiology Systems, Cockeysville, Md.) for identification of anaerobic bacteria from clinical specimens. With the coculture method, the Minitek anaerobe identification tests could be incubated under aerobic conditions. In 1,900 individual biochemical reactions, 1,826 (96%) were identical whether anaerobic conditions were achieved by conventional or coculture techniques. In comparison with the reference identification (Virginia Polytechnic Institute and State University, Blacksburg), both systems of incubation identified 91 of 99 strains (92%) correctly. The method of incubation had an effect on identification to the genus level in 1 of 99 (1%) strains and to the species level in 3 of 99 (3%) strains.

Bacteria, Anaerobic↗
PubMed1985

Comparison of American MicroScan dry and frozen microdilution trays.

This study compared the American MicroScan frozen microdilution tray and dehydrated microdilution tray. A total of 153 gram-negative and 106 gram-positive isolates were tested concurrently on both tray types and read visually. Very major and major antimicrobial susceptibility discrepancies amounted to 1.0% of all results, and minor discrepancies amounted to 0.4% of all results. The biochemical discrepancy rate for gram-negative organisms was 1.3%, resulting in no identification errors either at the genus or the species level. Gram-positive identification was not evaluated, as the formulation of biochemicals was changed after this evaluation was completed. Overall, the results with the dry tray were acceptable, providing a suitable alternative to the frozen tray.

Anti-Bacterial Agents↗
PubMed1985

Passive Heymann-like nephritis in the rabbit.

Rabbits injected with a guinea-pig anti-rabbit kidney fraction 3 antiserum developed immune complex deposition in the glomerulus which disappeared by the sixth day. The distribution of the glomerular deposits was similar to those of passive Heymann nephritis in the rat. A glomerular fixed antigen was not demonstrated in normal rabbit kidneys after perfusion with the guinea-pig anti-tubular antiserum. When tubular antigen was injected intraperitoneally in saline it could be detected in the glomeruli and after injection of the anti-tubular antiserum the deposits stained with increased intensity. Addition of a small amount of anti-GBM antiserum to the anti-tubular antiserum enhanced the size and number of glomerular deposits and increased their survival time. It is concluded that there is no pre-existing tubular antigen in the rabbit glomerulus and that the injected heterologous anti-tubular antiserum releases antigen from an extraglomerular source, probably the proximal tubules, and this released antigen becomes trapped in the glomerulus.

Animals↗
PubMed1985

Progressive passive Heymann nephritis: induction of autologous antibodies to rat brush border by multiple injections of heterologous antiserum.

Multiple i.v. injection of a heterologous anti-rat kidney fraction 3 antiserum and guinea pig anti-rabbit F3 into rats produced a progressive immune complex glomerulonephritis. The kidney disease was characterized by diffuse beaded deposition of rat gammaglobulin along the glomerular capillaries and proteinuria. Gammaglobulin eluted from the kidneys reacted with the brush border region of normal rat kidney frozen sections. Control animals did not develop the progressive disease. It appears that multiple i.v. injections of the heterologous antisera are capable of inducing an autoimmune kidney disease which is similar to Heymann nephritis.

Animals↗
PubMed1984

A new approach for presumptive identification of clinically important streptococci.

Several tests, bacitracin, CAMP, pyroglutamic acid-B-naphthylamide test (PYR test), bile aesculin hydrolysis, salt tolerance and pigment production tests were evaluated for their reliability and speed in presumptive identification of streptococci. Bacitracin correctly identified all of the group A streptococci but 5% of other beta haemolytic streptococci were misidentified as group A. The PYR reaction was just as sensitive but more specific for group A streptococci and the results were available within 2-3 h. The PYR reaction also effectively differentiated between enterococcal and non-enterococcal group D streptococci. Both the salt tolerance test and the PYR reaction misidentified bile aesculin positive non-group D streptococci as non-enterococcal group D streptococci. Pigment production by group B streptococci was more reliable than the CAMP test for identifying group B streptococci. The combination of PYR, bile aesculin and pigment production allowed rapid differentiation of several medically important groups of streptococci.

Bacitracin↗
PubMed1984

Development and evaluation of a coculture technique for identification of anaerobic organisms.

We investigated a method to reduce oxygen tension and produce anaerobic conditions conveniently by coculture with a nonfermentative organism. The biochemical reactions of 94 strains representing 41 different species were determined using prereduced media and gas chromatography according to standard methods. The standard reactions were compared with those obtained by preparing similar media, modified by containing no cysteine or resazurin, under aerobic conditions. Preincubation of the modified biochemical media with a standard suspension of a culture of Acinetobacter lwoffi provided reducing conditions. In 1,449 individual tests using 22 different biochemicals, 1,349 (93%) of the reactions agreed. Only two misidentifications resulted when using the modified media, one each at the species and genus levels. Two strains of Actinomyces odontolyticus failed to grow in coculture.

Acinetobacter↗
PubMed1984

Laboratory and clinical evaluation of modified New York City medium (Henderson formulation) for the isolation of Neisseria gonorrhoeae.

The growth-promoting properties of several ingredients of New York City (NYC) medium were investigated by using 100 recently isolated clinical strains of Neisseria gonorrhoeae. Difco GC medium base promoted the growth of large colonies of gonococci significantly better than other commercial GC medium bases. A 1% agar concentration resulted in the growth of larger colonies than 2% agar, without affecting the stability of the gel. Neither replacement of horse plasma with horse serum nor reducing the concentration of added serum from 12 to 3% affected the growth of even the most fastidious strains tested. From these observations, a modified NYC medium (Henderson) has been formulated which is easy to prepare and less expensive than NYC or Thayer-Martin medium. In a direct clinical comparison with 1,275 specimens, an isolation rate of 6.5% was achieved with both NYC medium and the Henderson formulation.

Culture Media↗