bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of various techniques for determining viability of Paracoccidioides brasiliensis yeast-form cells
Authors: Restrepo A , Cano L E , de Bedout C , Brummer E , Stevens D A
Published: January 2020

The viability of Paracoccidioides brasiliensis yeast-form cells was determined by colony-forming units, direct fluorescent staining, and production of germ tubes in slide culture. The first procedure was unreliable and time consuming; the latter two showed better correlation with hemacytometer total cell counts and required significantly less time.
Rapid microbiochemical method for identification of Gardnerella (Haemophilus) vaginalis
Authors: Yong D C , Thompson J S
Published: January 2020

A rapid biochemical method for the identification of Gardnerella vaginalis has been developed. The method is based on the fermentation of starch and raffinose and on the hydrolysis of hippurate. With this new procedure, identification was confirmed for 390 of 396 G. vaginalis isolates within 1 h after their inoculation into the three substrates.
Comparison of direct and indirect enzyme immunoassays with direct ultracentrifugation before electron microscopy for detection of rotaviruses
Authors: Hammond G W , Ahluwalia G S , Barker F G , Horsman G , Hazelton P R
Published: January 2020

A direct and an indirect enzyme immunoassay (EIA) were evaluated against a standard of electron microscopy after direct ultracentrifugation of the specimen for their performances in detecting rotaviruses. The indirect EIA had variable background activity which influenced test specificity. The indirect EIA control (test system without the detector antibody) plus a regression line (which reflected background noise) improved test specificity. However, the results of direct EIA (Rotazyme; Abbott Laboratories, North Chicago, Ill.) sensitivity (86%) and specificity (96%) were better than those of the indirect EIA in tests on 73 rotavirus-positive and 78 rotavirus-negative specimens. Endpoint titrations of purified SA-11 rotavirus showed greater sensitivity of the direct EIA test. Electron microscopy, performed after direct ultracentrifugation, and direct EIA were approximately 2 log10 more sensitive in the detection of purified SA-11 rotavirus than was electron microscopy with standard methods of unconcentrated specimen preparation. Direct EIA test are potentially sensitive, specific, and practical for the rapid detection of rotaviruses from human clinical specimens. Further studies are needed before EIA methods for detection of human rotaviruses can be equated with the level of reliability of results obtainable with sensitive electron microscopy techniques.
Sensitivity, specificity, and predictive values of the Limulus lysate assay for detection of exclusion of gonococcal cervicitis
Authors: Spagna V A , Prior R B , Sawaya G A
Published: January 2020

The Limulus amoebocyte lysate (LAL) assay was evaluated for its ability to detect or exclude gonococcal cervicitis in two groups of women. The first (positive) group consisted of 100 untreated women who were referred to the venereal disease clinic with culture-proven gonococcal cervicitis. The second (negative) group consisted of 50 normal volunteers who were evaluated on two separate occasions. In the first group, Gram stains and repeat cervical cultures were 53 and 93% sensitive, respectively. In the second group, Gram stains and cultures were negative. For the LAL assay, ectocervical mucus was removed with a sponge, and a depyrogenated cotton-tipped swab was then used to collect endocervical specimens. The swab was placed in 1 ml of diluent (1:1 dilution), and serial twofold dilutions were made and tested for endotoxin by the LAL assay. Incubation was carried out at 37 degrees C for 30 min; positive or negative results were indicated by gelation or lack of gelation, respectively. At a dilution of 1:256, sensitivity and specificity of the LAL assay were 57 and 99%, respectively. The positive predictive values ranged from 36.5 to 97.4% for theoretical prevalence rates of 1 to 40%. At a dilution of 1:8, the sensitivity and specificity were 100 and 78%, respectively. At this dilution, the negative predictive value was 100% regardless of the prevalence rate. Thus, these preliminary results show that at the higher dilution, the LAL assay was comparable to Gram stain in diagnostic accuracy of gonococcal cervicitis, and if used as a screening test at the lower dilution, a negative LAL assay would exclude women without gonococcal cervicitis.
Comparison of several test systems used for determination of rubella immune status
Authors: Weissfeld A S , Gehle W D , Sonnenwirth A C
Published: January 2020

Hemagglutination inhibition (HAI) is currently the most widely used technique for the determination of rubella immune status. However, two new methods, enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (FIAX), have also been adapted for this purpose. In comparing a commercially available ELISA system (BIO-BEAD, Litton Bionetics) with an HAI system (RUBA-tect, Abbott Laboratories), some ELISA-positive sera were found to be rubella antibody negative by the HAI system. To determine which of these results more accurately reflected the immune status of the patient, 74 RUBA-tect-negative sera were retested by ELISA BIO-BEAD, FIAX (International Diagnostic Technology) and by modified HAI, employing fresh erythrocytes (using Flow Laboratories reagents). Eleven RUBA-tect-negative sera (15%) were positive by ELISA, FIAX, and modified HAI. Two sera were positive only by ELISA and FIAX, two sera were positive by ELISA and HAI, four sera were positive by ELISA only, and one serum was positive by FIAX only. Neutralization assays were subsequently performed on sera positive by only one or two of the procedures to determine the presence of protective rubella antibodies in these sera; all but three of the sera were positive for neutralizing antibody. Commercial ELISA and FIAX systems appear to be more sensitive indicators of rubella immune status than are commercial HAI kits which use stabilized erythrocytes. Neither ELISA nor FIAX require extraction of serum; moreover, the ELISA BIO-BEAD test assay can be performed without an expensive instrument for reading.
Direct Testing of Blood Cultures for Detection of Streptococcal Antigens
Authors: Wetkowski Maryellen A. , Peterson Ellena M. , De La Maza Luis M.
Published: January 2020

A direct, rapid, and simple method for the detection of streptococcal antigens of Lancefield groups A, B, C, D, and G from blood cultures was developed by using a coagglutination test. Fifty-five clinical specimens and 117 simulated blood cultures containing gram-positive cocci were tested. Out of 6,261 clinical blood cultures screened, 55 cultures from 53 patients were positive, with organisms resembling streptococci, by Gram stain. Of these cultures, 78% (43 of 55) were pure cultures of streptococci, and 22% (12 of 55) were mixed with at least one other organism. Of the 43 pure cultures only, correct reactions were obtained (grouping correctly or giving no cross-reactions, or both) with 86% (37 of 43) of the isolates, 12% (5 of 43) exhibited cross-reactions, and 2% (1 of 43) gave false-negative reactions. All of the cross-reacting isolates were
Streptococcus pneumoniae
, which reacted with the group C reagent, and the false-negative reaction occurred with a
Streptococcus bovis
isolate. However, by using a direct modified bile solubility test, the correct identification of the
S. pneumoniae
isolates was obtained. Therefore, by using the modified bile solubility test in conjunction with the direct grouping method, 98% (42 of 43) of the isolates in pure culture could be identified accurately and rapidly after the detection of a positive Gram stain. Correct grouping reactions were obtained with 83% (10 of 12) of the mixed blood cultures, and false-negative results occurred with 17% (2 of 12) of them. Both cultures contained an enterococcus and a gram-negative rod. Of the 117 simulated blood cultures, there was only one incorrect grouping reaction; this occurred with an
S. bovis
isolate that cross-reacted with the group C reagent. The direct grouping reaction was positive when blood cultures contained a minimum of 1 × 10
8
to 8 × 10
8
colony-forming units per ml. In general, this procedure provided information on the identification of the organism 24 h earlier than by conventional identification methods.
Comparison of the API 20S Streptococcus identification system with an immunorheophoresis procedure and two commercial latex agglutination tests for identifying beta-hemolytic streptococci
Authors: Keville M W , Doern G V
Published: January 2020

The API 20S Streptococcus identification system and a new immunorheophoresis procedure were evaluated as means for determining the Lancefield serogroup of beta-hemolytic streptococci recovered from human clinical specimens. The serogroup of 96 strains was determined by these methods and by two commercially available latex agglutination tests. Streptex and SeroSTAT. The results of all four procedures were compared with the results of a classical precipitin test. The API 20S system correctly categorized 92.7% of the isolates; 94.8% were correctly identified by the immunorheophoresis procedure. The latex agglutination procedures were of comparable accuracy, yielding correct identifications with approximately 92% of the strains tested.
Rapid detection of simulated bacteremia by centrifugation and filtration
Authors: Herlich M B , Schell R F , Francisco M , Le Frock J L
Published: January 2020

A centrifugation-filtration procedure was developed to expedite the recovery of microorganisms from blood. Fresh whole human blood was inoculated with various aerobic and facultatively anaerobic microorganisms (3 to 18 per ml). The seeded blood was carefully overlaid on a Ficoll-Hypaque gradient (density, 1.114 g/ml) and centrifuged (400 x g) for 45 min at ambient temperature. The entire gradient (plasma, leukocytes, and Ficoll-Hypaque) was removed and filtered through a 0.22-micrometer membrane filter. The filters were then placed on chocolate agar and incubated at 35 degrees C in humidified air containing 5% CO2. No statistically significant differences were detected between the numbers of microorganisms recovered by filtration and by direct culture of the original inoculum. Most microorganisms were detected within 18 h after filtration. This system has excellent sensitivity and negligible toxicity.
Methicillin-resistant-Staphylococcus aureus colonization and infection in a rehabilitation facility
Authors: Aeilts G D , Sapico F L , Canawati H N , Malik G M , Montgomerie J Z
Published: January 2020

Methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection in a rehabilitation hospital (Rancho Los Amigos Hospital [RLAH]) were studied from October 1977 to May 1980. Eighty-four episodes of MRSA colonization or infection were observed in 81 patients (attack rate, 0.44 per 100 admissions). The MRSA was considered to have been acquired at RLAH in 65% of the episodes and from transferring hospitals in 34%. The infection rate was 35% among MRSA-colonized patients, and only one death was attributed to MRSA infection. Colonization for more than 100 days occurred most frequently in wounds and anterior nares. All but two of the MRSA isolates were resistant to aminoglycosides, and 80% of those typed belonged to phage type 83A. The patients were allowed to continue participation in rehabilitation programs. Spread of the MRSA occurred in wards where intensive medical and nursing care was being practiced. There was no evidence of MRSA spread in the services with less intense medical and nursing care and where physical and occupational therapy was continued. Patients in a rehabilitation hospital with MRSA colonization may receive intensive physical and occupational therapy as long as special precautions are observed to prevent MRSA spread.
Gelatin agar medium for detecting gelatinase production by anaerobic bacteria
Authors: Whaley D N , Dowell V R , Wanderlinder L M , Lombard G L
Published: January 2020

A new medium, Lombard-Dowell gelatin agar, was developed for detecting gelatinase activity by anaerobic bacteria. The medium contained: Trypticase (BBL Microbiology Systems), 5.0 g; yeast extract (Difco Laboratories), 5 g; sodium chloride, 2.5 g; sodium sulfite, 0.1 g; L-tryptophan, 0.2 g; L-cystine, 0.4 g; hemin, 10.0 mg; vitamin K1, 10.0 mg; agar, 20.0 g; D-glucose, 1.0 g; gelatin, 4.0 g; and distilled water to 1 liter. The pH was adjusted to 7.5. The medium was dispensed in 100- by 15-mm quadrant plastic dishes (5 ml per quadrant). To test for gelatinase activity, we inoculated the medium with a young enriched thioglycolate or chopped meat glucose broth culture or a turbid cell suspension in Lombard-Dowell broth, using a sterile cotton swab, and incubated it under anaerobic conditions for 48 h at 35 degrees C. The quadrants were then flooded with Frazier solution, and clear zones around the bacterial growth were recorded as positive for gelatinase activity. The new medium was tested with a variety of anaerobic bacteria, and the results were compared with data obtained with the conventional technique for detecting gelatinase activity. Overall, there was satisfactory agreement between the two tests in the detection of gelatinase activity, but the Lombard-Dowell gelatin agar tests was more rapid and somewhat more sensitive than the conventional test.
Plasmid and surface antigen markers of endemic and epidemic Legionella pneumophila strains
Authors: Brown A , Vickers R M , Elder E M , Lema M , Garrity G M
Published: January 2020

Environmental and clinical isolates of Legionella pneumophila obtained from the Pittsburgh Veterans Administration Medical Center were studied for the presence of plasmids and for unique surface antigens. The majority of environmental isolates contained a single 80-megadalton plasmid. After an epidemic of nosocomial Legionnaires disease subsided in the Spring of 1981, plasmid-bearing environmental isolates persisted in the environment. Whereas L. pneumophila could not be reisolated from most sites with plasmidless isolates. During this epidemic the attack rate was highest on wards with plasmidless isolates. All clinical isolates were plasmidless. Strains were serotyped by the indirect immunofluorescence method with serum from a single immunized rat which was used both without absorption and after absorption with various plasmid-bearing and plasmidless isolates. These studies suggested that a plasmid-associated surface antigen was present and that the most common plasmidless environmental serotype was similar to the epidemic clinical serotype.
Reliability of early identifications obtained with Enterobacteriaceae-plus biochemical cards in the automicrobic system
Authors: Barry A L , Badal R E
Published: January 2020

The AutoMicrobic system (AMS) is capable of identifying most Enterobacteriaceae within 8 h and many glucose-nonfermenting, gram-negative bacilli after 13 h of incubation. Early preliminary results can be readily obtained from the computer as the tests incubate. Data with 1,023 bacterial isolates were reviewed to determine the relative accuracy of 4-, 6-, 8-, 10-, and 13-h identifications. All AutoMicrobic system identifications with probability (P) values of less than 0.80 were considered equivocal responses which needed supplementary tests before a final report could be issued. Analysis of our data suggests that early identifications of Morganella morganii, Acinetobacter sp., Yersinia spp., Salmonella spp. (other than Salmonella typhi), Shigella spp. (other than Shigella sonnei), Enterobacter agglomerans, Pseudomonas spp. (other than Pseudomonas aeruginosa or Pseudomonas maltophilia), Klebsiella spp. (other than Klebsiella pneumoniae or Klebsiella oxytoca), Citrobacter amalonauticus, Serratia liquefaciens, or Vibrio spp. Should be considered nonspecific responses, even when P greater than or equal to 0.80. Other identifications reported after 4 h were 96% accurate. At least half of our isolates (60% of our Enterobacteriaceae) could be identified reliably within 4 h, the remaining isolates required longer incubation.
Comparison of vancomycin and penicillin for viral isolation
Authors: Forrer C B , Blahy O M , Maiatico A L , Campos J M , Friedman H M
Published: January 2020

Penicillin was compared with vancomycin for use in diagnostic virology to inhibit bacterial contamination of clinical specimens. Vancomycin when combined with gentamicin and amphotericin B was found to be more effective in lowering the overall contamination rate than when penicillin was combined with these antibiotics (penicillin group, 14.9% versus vancomycin group, 6.2%; P less than 0.001). Of the contaminants grown in the presence of penicillin, 72% were gram-positive cocci, primarily coagulase-negative staphylococci. The number of gram-positive contaminants in the presence of vancomycin was reduced to zero. There was little difference in the rates of gram-negative rod or fungus contamination. The viral isolation rate in noncontaminated specimens was similar with either penicillin or vancomycin, but was reduced when specimens became contaminated. The time for virus detection and the morphology of cytopathology were similar in penicillin- and vancomycin-treated specimens. Vancomycin is an effective alternative to penicillin in reducing the growth of contaminants in viral isolation specimens.
Comparison of two methods used to prepare smears of mouse lung tissue for detection of Pneumocystis carinii
Authors: Thomson R B , Smith T F , Wilson W R
Published: January 2020

The laboratory diagnosis of Pneumocystis carinii pneumonia in humans includes the identification of cysts in stained lung tissue impression smears. By using a mouse model, we compared the number of cysts in lung tissue impression smears with those contained in a concentrate of homogenized lung tissue. Eleven C3H/HEN mice developed P. carinii infection after corticosteroid injections, a low protein (8%) diet, and tetracycline administered in drinking water. Impression smears were prepared with freshly bisected lung tissue. Smears of concentrates were prepared with sediment from centrifuged lung tissue homogenates. All smears were made in duplicate, stained with toluidine blue O or methenamine silver, coded, randomized, and examined. The concentrate preparations contained more cysts per microscopic field than the impression preparations (P less than 0.01). Concentrates prepared by grinding with a mortar and pestle contained more cysts than concentrates prepared by blending with a Stomacher (P less than 0.05). Cysts were detected equally well with either the toluidine blue O or silver stain (not significant). Lung tissue concentrates were superior to lung tissue impressions for detecting P. carinii cysts in mice. Use of lung tissue concentrates should be considered for the diagnosis of human P. carinii infection.
Horse erythrocyte glycoprotein-latex reagent that reacts with infectious mononucleosis heterophile antibody
Authors: Fletcher M A , Caldwell K E , Saez L , Latif Z
Published: January 2020

A sialoglycoprotein from horse erythrocytes was isolated in essentially homogeneous form and found to contain the neuraminidase-sensitive determinant of the horse erythrocyte for Paul-Bunnell heterophile antibodies of infectious mononucleosis. This reactivity was retained after covalent coupling of the antigen to latex particles. The latex reagent has greater stability (greater than 3 years) than either fresh or preserved horse erythrocytes. It can be used in a direct slide test; no absorption of the serum is necessary. The new test compared favorably with some standard tests for infectious mononucleosis antibody which use horse erythrocytes. Agreement of the latex test with the absorbed fresh horse cell test was 100%, and agreement with a stabilized horse erythrocyte spot test was 94%. The latex test also agreed 100% with a radioimmunoassay for the detection of heterophile antibody with 125I-labeled horse erythrocyte glycoprotein. The new latex test was compared with a bovine erythrocyte glycoprotein-latex test, and a correlation of 94% was observed. In addition, it was compared with the Wöllner test (enzyme-treated sheep cell-absorbed sheep cell agglutination test) with which it agreed in 92% of samples tested.
Nutritional requirements of Corynebacterium pyogenes
Authors: Fraga A M , Reddy C A
Published: January 2020

The nutritional requirements of Corynebacterium pyogenes (strains C100, 5, and 1909), a commonly encountered animal pathogen, were determined in this study. A semidefined medium (SDM) containing glucose, HCO3-, hemin, charcoal-treated Trypticase, and a defined mixture of purines and pyrimidines, amino acids, and minerals which supported optimal growth of C. pyogenes was employed in all nutritional studies. Adenine and uracil were required for optimal growth of strains 5 and C100 but were not required for strain 1909. Riboflavin and nicotinic acid were required for good growth of all three strains; biotin and thiamin were stimulatory but did not appear to be required for growth. Hemin and NaHCO3 were stimulatory for growth, whereas lipoic acid and Tween 80 were neither stimulatory nor required for growth. The replacement of Trypticase with a specific peptide fraction (obtained by fractionation of Trypticase on Sephadex G-25) rich in dipeptides gave growth comparable to that in SDM, indicating a peptide requirement for the growth of C. pyogenes. It was of considerable interest that growth comparable to that in SDM was obtained when Trypticase was replaced by inositol (1 microgram/ml of SDM).
Analysis of short-chain acids from anaerobic bacteria by high-performance liquid chromatography
Authors: Guerrant G O , Lambert M A , Moss C W
Published: January 2020

A standard mixture of 25 short-chain fatty acids was resolved by high-performance liquid chromatography, using an Aminex HPX-87 column. The acids produced in culture media by anaerobic bacteria were analyzed by high-performance liquid chromatography after extraction with ether and reextraction into a small volume of 0.1 N NaOH. The presence of fumaric acid in culture extracts of Peptostreptococcus anaerobius was confirmed by gas chromatography-mass spectrometry analysis of the trapped eluent fractions from the high-performance liquid chromatography column.
Isolation of human rotaviruses in primary cultures of monkey kidney cells
Authors: Hasegawa A , Matsuno S , Inouye S , Kono R , Tsurukubo Y , Mukoyama A , Saito Y
Published: January 2020

We succeeded in isolating human rotaviruses from the feces of gastroenteritis patients by using roller cultures of primary cynomolgus monkey kidney cells with trypsin in the maintenance medium but without concentration and trypsin treatment of the inocula at each passage level. These cells were found to be more sensitive than MA-104 cells (derived from fetal rhesus monkey kidney) for the propagation of human rotaviruses. Polyacrylamide gel electrophoresis of the genome RNA revealed that there were small differences in the migration pattern of the segments among all the strains isolated from 1976 to 1981. The cultivation of human rotaviruses in primary cell cultures might aid in developing a liver rotavirus vaccine.
Antibody reactive with Peptostreptococcus micros in the sera of patients with periodontal disease
Authors: Graham M B , Falkler W A , Spiegel C A , Hayduk S W , Dober L G
Published: January 2020

Subgingival plaque samples were cultured for the isolation of Peptostreptococcus micros from individuals with and without chronic periodontitis. Humoral antibody from each person reacted with P. micros in an indirect fluorescent-antibody test, but not all of the sera reacted in a passive hemolysis test. No correlations were observed between the presence of antibody reactive with P. micros and the isolation of P. micros or the gingival health of the individual.
Beta-lactamase testing of staphylococci in a commercial broth microdilution minimum inhibitory concentration system
Authors: Horton K A , Jennings B R , Baselski V S
Published: January 2020

Beta-Lactamase testing of clinical isolates of staphylococci may be performed in commercial broth microdilution minimum inhibitory concentration plates, using a chromogenic cephalosporin reagent directly in a well containing a noninhibitory concentration of a semisynthetic penicillin which serves as an inducer. A total of 115 staphylococcal isolates tested in 0.25 to 0.50 microgram of methicillin per ml in Mueller-Hinton broth showed 100% correlation with beta-lactamase tests performed on Mueller-Hinton agar, using 1-microgram oxacillin disk as an inducer.
Comparison of Virus Culturing and Immunofluorescence for Rapid Detection of Respiratory Syncytial Virus in Nasopharyngeal Secretions: Sensitivity and Specificity
Authors: Lauer Brian A.
Published: January 2020

I compared the fluorescent antibody test for respiratory syncytial virus in nasal secretions to virus cultures (
N
= 310). The sensitivity, specificity, and predictive value (+) were 95.1%, 86.5%, and 88.5%, respectively.
Enzymatic profile of Pseudomonas maltophilia
Authors: O'Brien M , Davis G H
Published: January 2020

An enzymatic profile of 20 strains of Pseudomonas maltophilia was undertaken with conventional plate tests, API ZYM, and 4-methylumbelliferyl-conjugated substrates. All strains produced DNase, RNase, arbutinase, esterases and lipases, mucinase, acid and alkaline phosphatases, alkaline pyrophosphate diesterase, phosphoamidase, beta-glucosidase, leucine arylamidase, and acetatase and were hemolytic for horse, sheep, and rabbit blood. The majority of strains produced chitinase, hyaluronidase, albuminase, valine arylamidase, trypsin, alpha- and beta-glucosidases, and N-acetyl-beta-glucosaminidase. API ZYM and 4-methylumbelliferyl-conjugated substrate assays are rapid, simple, specific, and sensitive and may be useful as diagnostic aids in the identification of P. maltophilia and other pseudomonads.
Controlled evaluation of the effect of atmosphere of incubation on detection of bacteremia and fungemia in supplemented peptone broth
Authors: Tenney J H , Reller L B , Mirrett S , Weinstein M P , Wang W L
Published: January 2020

To evaluate the role of atmosphere of incubation in the detection of clinically important bacteremia and fungemia in adults, we compared the yield of microorganisms from 10,541 paired 5-ml samples of blood incubated aerobically and anaerobically. The medium, supplemented peptone broth (SPB) with 0.03% sodium polyanetholesulfonate, and the ratio of blood to broth (1:10) were the same for all cultures. Only cultures with adequate blood samples (greater than or equal to 80% of stated volume) were compared statistically. More fungi (P less than 10(-7) ) grew in continuously vented bottles of SPB. Aerobic incubation also favored (P less than 0.01) isolation of Neisseria gonorrhoeae and Eubacterium; more than 80% of these bacterial organisms were detected only in vented bottles. Anaerobic incubation (plugged venting units) did not significantly favor the isolation of any genus of microorganisms, although an estimated 11% more Bacteroidaceae grew in the unvented bottle of SPB. By comparison of our data with published results for other media, we conclude that the need for both aerobic and anaerobic incubation of blood cultures is dependent upon the medium used and the microorganisms likely to be encountered. Vented incubation of blood cultured in SPB is crucial for detection of fungi and some bacteria. Routine use of an unvented bottle of SPB may not be worthwhile for patients in whom Bacteroidaceae cause bacteremia infrequently. However, when Bacteroidaceae are suspected as the cause of sepsis, use of an unvented bottle of SPB is prudent.
Bacteriuria caused by Acinetobacter calcoaceticus biovars in a normal population and in general practice
Authors: Hoffmann S , Mabeck C E , Vejlsgaard R
Published: January 2020

A total of 14 strains of Acinetobacter calcoaceticus biovar anitratus and 93 strains of A. calcoaceticus biovar lwoffi from a total of 97 patients participating in studies of significant bacteriuria were cultured. These studies involved an interview survey of asymptomatic significant bacteriuria and a multiple-center investigation of urinary tract infection diagnosed in general practice. Antibiotic susceptibilities of the strains as determined by a disk diffusion technique were generally in agreement with the results in the available literature, although we found high activity exhibited by ampicillin, cephalosporin, chloramphenicol, erythromycin, and streptomycin. The following resistance patterns were seen. (i) The strains from the interview survey were more often resistant to ampicillin, oxacillin, and tetracycline than were strains from the general practice study. (ii) More biovar anitratus strains than biovar lwoffi strains were resistant to chloramphenicol, erythromycin, and mecillinam. (iii) More biovar anitratus strains than biovar lwoffi strains were resistant to carbenicillin in the interview survey. The literature relevant to the incidence and significance of A. calcoaceticus biovars in urinary cultures, as well as predisposing factors, was reviewed. The incidence of these organisms in significant bacteriuria seems to be increasing. We concluded that A. calcoaceticus biovars can cause urinary tract infection in abnormal hosts as well as in basically healthy individuals.
Demonstration of extracellular chymotrypsin-like activity from various Legionella species
Authors: Berdal B P , Olsvik O , Myhre S , Omland T
Published: January 2020

Concentrated extracellular supernatants from Legionella pneumophila, L. bozemanii, L. dumoffi, L. gormanii, but not L. micdadei, exhibited a strong chymotrypsin-like activity upon synthetic chromogenic tri- and tetrapeptides. Bacterial cell sonic extracts showed low protease activities, different from those of the extracellular concentrates. Extracellular concentrates were also tested in the API ZYM system, where weak protease activity only was recorded. Protease inhibitors decreased the activity of the extracellular Legionella proteases upon the chromogenic peptides.
Serotypes of Pseudomonas aeruginosa in clinical specimens in relation to antibiotic susceptibility
Authors: Legakis N J , Aliferopoulou M , Papavassiliou J , Papapetropoulou M
Published: January 2020

Ninety-eight hospital strains of Pseudomonas aeruginosa isolated from six different hospitals in Athens were serotyped by a slide agglutination test with unabsorbed commercial antisera. Serotypes O6, O11, O12, and "pool E" strains (strains that agglutinated only in pool E, which contained antisera against O2, O5, O15, and O16 antigens, but did not agglutinate in the individual antisera) predominated, accounting for more than 62% of all isolates tested. In respect to serotypes, (i) there was no apparent correlation with hospital of origin, (ii) most strains of serotypes O6 and O11 were sensitive to gentamicin and carbenicillin (iii) most strains of pool E were from urine and were resistant to these drugs, (iv) all 9 strains of serotype O12 tested were resistant to carbenicillin and all 5 strains tested hydrolyzed this drug, and (v) 24 of 25 strains of pool E were resistant to carbenicillin but only 2 of 17 strains hydrolyzed it.
Fluorescent-antibody test for detection of Clostridium difficile in stool specimens
Authors: Wilson K H , Silva J , Fekety F R
Published: January 2020

We evaluated a direct fluorescent-antibody test to detect Clostridium difficile, the most frequent cause of antibiotic-associated colitis. C. difficile organisms were injected into the ear veins of New Zealand White rabbits to induce antibodies, and the globulin fractions of their sera were conjugated to fluorescein isothiocyanate. The resulting conjugate strongly stained all 40 isolates of C. difficile tested. It also stained isolates of C. sordellii, C. bifermentans, C. chauvoei, and C. sporogenes, but not 20 other clostridial isolates or 10 isolates from other species. Results of testing fecal smears with the direct fluorescent-antibody method were compared with results of testing stools for C. difficile toxin and of culturing for C. difficile on a selective medium. A total of 158 fecal specimens from patients with antibiotic-associated diarrhea were tested. In these patients, the fluorescent-antibody test agreed with culture and toxin testing in 93% of the specimens. However, in normal adults, 62% of the fecal specimens from which C. difficile could not be cultured were positive by the fluorescent-antibody test. Absorption of the conjugate with C. sordellii led to a loss of reactivity to other clostridia as well as to 18 of 20 isolates of C. difficile.
Enzyme-linked immunosorbent assay for identification of infectious pancreatic necrosis virus
Authors: Nicholson B L , Caswell P
Published: January 2020

The sensitivity, reproducibility, and specificity of an enzyme-linked immunosorbent assay for the identification of infectious pancreatic necrosis virus was determined. It was shown that 10(5.5) tissue culture infectious doses could be assayed by this method. The assay provided significant advantages in terms of time and ease of performance over the routinely employed serological tests. When an antiserum against a single isolate was used, it was possible to identify nine of ten North American isolates, four of six European isolates, and one isolate from Taiwan.
Rapid diagnosis of rotavirus infection by direct detection of viral nucleic acid in silver-stained polyacrylamide gels
Authors: Herring A J , Inglis N F , Ojeh C K , Snodgrass D R , Menzies J D
Published: January 2020

A rapid simple technique for the diagnosis of rotavirus has been developed based on the sensitive detection of rotavirus double-stranded RNA genome segments separated in polyacrylamide gels. The method utilizes a recently described ultrasensitive silver stain for polypeptides, which can also detect subnanogram amounts of nucleic acid. The sensitivity of the technique is comparable with that of electron microscopy or enzyme-linked immunosorbent assay.
Antigenic relationships among some animal rotaviruses: virus neutralization in vitro and cross-protection in piglets
Authors: Gaul S K , Simpson T F , Woode G N , Fulton R W
Published: January 2020

The serotype, RNA electropherotype, and cross-protection properties of rotaviruses isolated from canine, simian, porcine, and human species were compared. The bovine strain B:USA:78:1A and the canine strain C:USA:81:2 were adapted to cell culture and cloned in this study. The other viruses, i.e., simian strain S:USA:79:2, porcine Ohio State University strain P:USA:77:1, and human strain WA, were already cell culture adapted, although they were further cloned for this work. The serum neutralization test was used to classify the viruses into serotype groups. Viruses which exhibited a difference of 20-fold or greater in neutralization titer were separated into different serotype groups. In this study, four major serotype groups were found, and these groups were represented by bovine, human, porcine, and canine-simian strains. From cross-protection studies, these serotype groups were found to be significantly different. With the exception of the porcine strain, none of the viruses used as vaccines protected gnotobiotic piglets from challenge with the virulent porcine Ohio State University strain of rotavirus. Furthermore, the canine virus protected piglets from challenge with the simian virus. The RNA electropherotype confirmed that the canine and simian strains were different in eight RNA segments and eliminated the possibility that they were the same virus. From these findings, it was concluded that only viruses belonging to the same serotype group can be expected to confer cross-protection, and thus, vaccines should be made with the serotypes to which the animal is likely to be exposed.
Pneumonia caused by a previously undescribed bacterium
Authors: Hopfer R L , Mills K , Fainstein V , Fischer H E , Luna M P
Published: January 2020

A new and as yet unidentified bacterium was isolated from the lung tissue of a cancer patient with bilateral pneumonia. Clinically, the pneumonia was consistent with legionellosis; the organism cultured from the lung grew only on the charcoal-yeast extract agar routinely used for Legionella isolation. Subsequent testing, however, showed the organism to be quite distinct from the known Legionella species in its biochemical, antigenic, and growth characteristics.
Methylcellulose media for plaque assay of murine leukemia virus
Authors: Watanabe T , Horikawa Y , Sato K , Saito H
Published: January 2020

When ecotropic murine leukemia virus was assayed by a methylcellulose-XC cell procedure, plaque titers showed less test-to-test variation, more uniform dose-response curves, and larger plaque sizes, as compared with results of the conventional liquid overlay-XC cell test system. This assay therefore seems to be reliable and useful for the titration of ecotropic murine leukemia virus.
Levels of antibody against Legionella pneumophila serotype 1 in healthy populations in five areas in New Zealand
Authors: Bettelheim K A , Metcalfe R V , Sillars H
Published: January 2020

Levels of antibody to Legionella pneumophila serogroup 1 in five areas of New Zealand were determined by indirect immunofluorescence. Both immunoglobulin G (IgG) and IgM levels were separately assessed. Of the 500 people studied, 2.8% had IgG titers of greater than or equal to 1:128 and 4.0% had IgM titers of greater than or equal to 1:128. Higher levels of IgG reactivity were noted in the southern part of New Zealand, but neither age nor sex appeared to be related to variations in antibody levels.
Comparison of Rotazyme and direct electron microscopy for detection of rotavirus in human stools
Authors: Cheung E Y , Hnatko S I , Gunning H , Wilson J
Published: January 2020

A total of 115 stools were examined for Rotavirus, using direct electron microscopy (EM) and Rotazyme. The overall agreement was 88.7%. Of the negative results, there was 91.95% agreement. Rotazyme reactions of three-plus or more gave a 100% agreement with EM. The Rotazyme test is a useful diagnostic aid in laboratories not capable of performing EM.
Brucella suis: an unusual cause of suppurative lymphadenitis in an outpatient
Authors: Nadler H , Dolan C , Forgacs P , George H
Published: January 2020

A routine aerobic culture of purulent material from a draining sinus tract of a patient with chronic lymphadenitis yielded growth of a fastidious gram-negative coccobacillus later identified as Brucella suis biotype 1. The patient responded to administration of antibacterial drugs and surgical drainage.
Rapid detection of significant bacteriuria by use of an automated Limulus amoebocyte lysate assay
Authors: Jorgensen J H , Alexander G A
Published: January 2020

Previous studies have demonstrated that significant gram-negative bacteriuria can be detected by using the Limulus amoebocyte lysate test. A series of 580 urine specimens were tested in parallel with the automated MS-2 (Abbott Laboratories) assay and with quantitative urine bacterial cultures. The overall ability of the MS-2 Limulus amoebocyte lysate test to correctly classify urine specimens as containing either greater than or equal to 10(5) organisms or less than 10(5) organisms per ml during a 20-min test period was 92.6%.
Neisseria sicca osteomyelitis
Authors: Doern G V , Blacklow N R , Gantz N M , Aucoin P , Fischer R A , Parker D S
Published: January 2020

Neisseria sicca was identified as the cause of vertebral osteomyelitis in a male patient who had previously suffered a nonpenetrating, traumatic back injury. The identifying characteristics and antimicrobial susceptibility patterns are presented for this rare human pathogen, which heretofore has not been reported as a cause of infection localized to bone.
Lung Infection Caused by
Gordona aurantiaca
(
Rhodococcus aurantiacus
)
Authors: Tsukamura Michio , Kawakami Keiji
Published: January 2020

We report that
Gordona aurantiaca
(
Rhodococcus aurantiacus
) caused a lung infection in humans. The case of a 50-year-old male farmer is shown. This is the first report of infection by this organism.
Comparative Study of Selective Media for Recovery of
Yersinia enterocolitica
Authors: Head Carol B. , Whitty Deborah A. , Ratnam Samuel
Published: January 2020

To determine the relative efficacy of pectin agar, cellobiose-arginine-lysine (CAL) agar, Y medium, cefsulodin-irgasan-novobiocin (CIN) agar, MacConkey (MAC) agar, and salmonella-shigella (SS) agar for the recovery of
Yersinia enterocolitica
, 35 strains of this organism representing the serotypes most commonly associated with human disease in Canada and the United States were inoculated on test media in pure cultures and mixed in fecal specimens. Randomly picked stool specimens were also cultured on these media to determine their selectivity. The ability of test media to support the growth of
Y. enterocolitica
strains varied markedly. Several strains failed to grow on Y medium, and a few failed to grow on SS agar. There were no significant differences in cultural characteristics and the recovery rates of Canadian and American strains. The combined recovery of the pure cultures of
Y. enterocolitica
on test media as compared with blood agar was MAC, 75%; SS, 48%; pectin, 70%; CAL, 62%; Y, 15%; and CIN, 85%. The selectivity of the test media expressed as the percent difference of the fecal colony counts obtained on blood agar and the selective media was MAC, 7%; SS, 50%; pectin, 4%; CAL, 65%; Y, ≥99.9%; and CIN, 95%. When stool suspensions containing 10
2
colony-forming units of the test strains were plated, CIN medium yielded 100% recovery of all 35 strains from all fecal samples. The combined recovery rate for other media was CAL, 63%; Y, 14%; and SS, 11%. With 10
1
colony-forming units, CIN yielded a 100% recovery of the test strains, whereas CAL, Y, and SS agar showed a 0% recovery. None of the test organisms was recovered on either MAC or pectin agar at either dilution. The inhibitory effect of Y medium for
Y. enterocolitica
could be overcome to some extent by reducing the sodium oxalate and sodium desoxycholate content of the medium. One such modified Y medium offered optimum selectivity and ensured greater recovery of
Y. enterocolitica
when compared with the Y medium. We found CIN agar by far the most effective medium for the recovery of
Y. enterocolitica.
This medium was highly selective and almost completely inhibited the fecal flora, while at the same time supporting luxuriant growth of
Y. enterocolitica.
On CIN agar,
Y. enterocolitica
colonies were distinctive in appearance and measured 1.5 to 4 mm in diameter within 20 to 40 h of incubation.
Comparison of the latex agglutination test with the hemagglutination inhibition test, enzyme-linked immunosorbent assay, and neutralization test for detection of antibodies to rubella virus
Authors: Meegan J M , Evans B K , Horstmann D M
Published: January 2020

The ability of a rapid, latex agglutination test to diagnose rubella infection and to measure immune status was evaluated by comparison with the hemagglutination-inhibition (HAI) test, enzyme-linked immunosorbent assay (ELISA), and the neutralization (NT) test. The latex agglutination test accurately detected serological conversions in 74 pairs of sera representing 21 natural infections and 53 immunizations. The antibody levels of 276 sera from the general population were determined by latex agglutination, HAI, and ELISA. The correlation coefficients between the titers obtained by HAI and latex agglutination and by ELISA and latex agglutination were statistically significant. Results on 12 sera did not agree when measured by the three tests. These sera were included among the 196 specimens tested by NT. The correlation coefficient between NT and latex agglutination titers was statistically significant. There was one serum positive by latex agglutination but negative by NT, and five sera were negative by latex agglutination but had titers of 4 to 8 in the NT. The relative sensitivity of detecting antibody was greater by latex agglutination than by HAI. An additional 49 sera containing residual nonspecific hemagglutinin inhibitors were evaluated by latex agglutination and NT. The untreated sera showed no false positive reactions, and 36 of 39 NT positive sera were positive in the latex agglutination test.
New method of antibody detection by indirect immunoperoxidase plaque staining for serodiagnosis of African swine fever
Authors: Pan I C , Huang T S , Hess W R
Published: January 2020

An indirect immunoperoxidase plaque-staining method was developed for detecting antibody to African swine fever virus infection. In both sensitivity and specificity, the test was comparable to indirect immunofluorescence. Because it has all of the desirable features of the indirect immunofluorescence test and may also be readily used for testing large numbers of sera, the indirect immunoperoxidase plaque-staining method can be used as a single and final serodiagnostic test in a large-scale survey of African swine fever. The indirect immunoperoxidase plaque-staining method should be applicable to other viruses that can be adapted to and grown in cell cultures.
Detection of group B streptococcal antigen in early-onset and late-onset group B streptococcal disease with the Wellcogen Strep B latex agglutination test
Authors: Ingram D L , Suggs D M , Pearson A W
Published: January 2020

The Wellcogen Strep B latex agglutination test (Wellcome Diagnostics, Dartford, England) was evaluated as a method of detecting group B streptococcal antigen in urine, cerebrospinal fluid, and serum from neonates with early-onset (less than or equal to 7 days of age) and late-onset group B streptococcal disease. Urine was the best source of antigen, which was detected in 100% of six neonates with early-onset group B streptococcal disease who had urine available in the first 12 h of illness and in 88% of 17 group B streptococcus-infected neonates with urine available in the first 48 h of illness. Antigen was not detected in any samples from patients without group B streptococcal disease except in the urine of one patient with Proteus mirabilis meningitis. The Wellcogen Strep B latex test of the lot tested compares favorably with a noncommercially available latex agglutination test.
Evaluation of the Minitek system for direct identification of anaerobic rods from positive blood cultures
Authors: Polomski J C , McClatchey K D
Published: January 2020

The direct inoculation of the Minitek anaerobe identification system (BBL Microbiology Systems, Cockeysville, Md.) from positive blood cultures was compared with subculture and Minitek results obtained using the manufacturer's recommended procedures. A total of 40 clinical anaerobic blood cultures were processed for rapid identification utilizing bacterial pellets obtained by centrifugation. Of these cultures, 30 yielded pure isolates of anaerobic rods that were used for comparison. In 87% of the pure cultures, identification from the direct inoculum method was identical to the routine procedure using Minitek biochemicals. When the additional test for lecithinase and lipase production was included, the identification agreement was 97%. Direct identification of anaerobic rods from blood cultures utilizing the Minitek system is reliable, easy to perform, and can provide a complete identification in 24 h from the time a blood culture showed growth.