bluuebunny/crossref_metadata_2025 huggingface dataset:
Rotavirus-Like, Calicivirus-Like, and 23-nm Virus-Like Particles Associated with Diarrhea in Young Pigs
Authors: Saif Linda J. , Bohl Edward H. , Theil Kenneth W. , Cross Robert F. , House James A.
Published: January 2020

Virus particles morphologically similar to caliciviruses and rotaviruses were detected by electron microscopy (EM) in the intestinal contents of a 27-day-old diarrheic nursing pig. A third small spherical 23-nm virus-like particle was also observed. Calicivirus-like particles averaged 33 nm in diameter. Similar to rotaviruses, rotavirus-like particles were present as single-capsid 55-nm forms or double-capsid 70-nm particles. Most gnotobiotic pigs orally exposed to samples containing these three viruses developed diarrhea and villous atrophy of the small intestine, and all shed the three viruses in their intestinal contents. Attempts to propagate these viruses in cell culture were unsuccessful. The antigenic relationship of the rotavirus-like particles to known rotaviruses was explored by immune EM and immunofluorescent staining. By these techniques, the rotavirus-like particles did not cross-react with antisera to porcine, bovine, or human rotaviruses or to reovirus type 3. Antisera from gnotobiotic pigs exposed to all three viruses had enzyme-linked immunosorbent assay and virus neutralization titers of <4 against porcine rotavirus. Previous infection of gnotobiotic pigs with the mixture containing rotavirus-like particles failed to protect them against a subsequent challenge with porcine rotavirus. The antigenic relationship of the calicivirus-like particles to known caliciviruses was investigated by immune EM and virus neutralization. By these tests, the calicivirus-like particles did not react with antisera against feline calicivirus strain 255 or M-8. In a study conducted at Plum Island Animal Disease Center, antiserum against the three combined agents did not specifically neutralize any serotype of swine vesicular exanthema virus.
Isolation of Leptospira biflexa from commercially prepared deionized water labeled "sterile for tissue culture"
Authors: Rubin S J , Perlman S , Ellinghausen H C
Published: January 2020

Leptospira biflexa were isolated from urine cultures of two patients with clinical and laboratory findings compatible with leptospirosis. Neither patient had detectable leptospiral agglutinins. The source of the L. biflexa was water labeled " "sterile for tissue culture" purchased from M. A. Bioproducts, formerly Microbological Associates. M. A. Bioproducts water is sterilized by filtration through a 0.22-mum-pore size membrane filter. Leptospiral contamination can occur in products sterilized by filtration. Heat sterilization of water eliminates this possibility.
Biochemical properties of CO2-dependent streptococci
Authors: Pulliam L , Porschen R K , Hadley W K
Published: January 2020

A total of 153 clinical isolates and 10 reference strains were employed in an investigation of CO2-dependent streptococci. Their selection was based on a lactic acid homofermentative end product. This group of organisms grew best in 5 to 10% CO2, and several species, including Streptococcus mutans, S. intermedius, Streptococcus MG, S. anginosus, and S. constellatus, required increased CO2 for primary recovery. A basal medium of thioglycolate with 0.1% Tween 80 and phenol red was prepared and used with selected carbohydrates. This media provided luxuriant growth. Serological testing failed to give any definitive correlation with species identification. A shortened differentiation scheme, combined from previous studies, was proposed.
Urease-positive Vibrio parahaemolyticus strain
Authors: Lam S , Yeo M
Published: January 2020

An unusual strain of Vibrio parahaemolyticus was isolated from the site of a perforated appendix. This was the first reported case in which the vibrios demonstrated a positive urease reaction. In other respects, the strain conformed to the general characteristics of V. parahaemolyticus. It was susceptible to chloramphenicol, sulfamethoxazole-trimethoprim, tetracycline, neomycin, triple sulpha, gentamicin, and polymyxin B and produced the "Kanagawa phenomenon". However, its role as a causative pathogen of the diarrhea of the patient was debatable.
Comparative studies on two antigens (F4 and TM) extracted from leptospires
Authors: Adler B , Faine S , Yanagawa R
Published: January 2020

F4 and TM antigens extracted from Leptospira interrogans serovars pomona, icterohaemorrhagiae, and copenhageni were compared by immunodiffusion, by hemagglutination inhibition, and by selective absorption of antisera. These data, together with previous information on the serological specificities of the two antigen preparations, suggest that F4 and TM are different antigens.
Unusual groups of Morganella ("Proteus") morganii isolated from clinical specimens: lysine-positive and ornithine-negative biogroups
Authors: Hickman F W , Framer J J , Steigerwalt A G , Brenner D J
Published: January 2020

Morganella ("Proteus") morganii is the only species in the recently proposed genus Morganella, but we suspect there are yet undescribed species in the genus. Two candidates for new species were recently investigated. Nineteen strains isolated from clinical specimens resembled M. morganii but were lysine positive and nonmotile and fermented glycerol within 24 h. Typical M. morganii are lysine negative and motile and ferment glycerol slowly or not at all. The three-test variance from typical M. morganii suggested that this new group might be a new Morganella species; however, strains of the group were closely related to typical M. morganii by deoxyribonucleic acid (DNA)-DNA hybridization. A second group of 14 strains isolated from clinical specimens was ornithine negative but was otherwise very similar to M. morganii. This group was also closely related to M. morganii by DNA hybridization. Both sets of strains clearly belong in the species Morganella morganii as distinct biogroups; they are not separate species as originally suspected. Initially both biogroups posed a problem in identification until their true relationship to M. morganii was determined.
Rapid tube CAMP test for identification of Streptococcus agalactiae (Lancefield group B)
Authors: Phillips E A , Tapsall J W , Smith D D
Published: January 2020

A rapid CAMP test for the presumptive identification of Streptococcus agalactiae (Lancefield group B) is described. Sheep erythrocytes, sensitized by staphylococcal beta-lysin and suspended in phosphate-buffered saline, were used to determine the lytic capacity of the neutralized supernatant fluids of 4-h broth cultures of streptococci being tested. A total of 96.2% of 130 group B streptococci gave positive CAMP tests, that is, lysis of the sheep erythrocytes after 10 min of exposure of streptococcal supernatants, whereas none of 381 non-group B streptococci tested produced any lysis. The test described provides presumptive identification of group B streptococci within 4 h and eliminates problems of intermediate reactions so that a positive test is indicative only of CAMP factor production.
Prothrombin activation by a metalloprotease from Staphylococcus aureus
Authors: Wegrzynowicz Z , Heczko P B , Drapeau G R , Jeljaszewicz J , Pulverer G
Published: January 2020

Formation of thrombin during incubation of purified bovine prothrombin with purified staphylococcal metalloprotease has been investigated. Thrombin activity was estimated by examination of clotting time and by digestion of a synthetic substrate, Chromozym TH. The metalloprotease caused direct activation of prothrombin which was inhibited by the addition of ethylenediaminetetraacetic acid. Metalloprotease produced by some strains of Staphylococcus aureus may simulate staphylocoagulase activity.
Chemiluminescence-linked immunoassay for detection of mumps virus antibodies
Authors: Konishi E , Iwasa S , Kondo K , Hori M
Published: January 2020

We have developed a simple and sensitive chemiluminescence-linked immunoassay (CLIA) for determining mumps virus antibodies. Luminol molecules were used as markers, and polystyrene balls were used as antigen carriers. The CLIA was compared with an enzyme-linked fluorescence assay and a hemagglutination inhibition test on a total of 40 serum specimens obtained from 29 donors with natural infection or vaccination. There was good correlation between the three methods, and the sensitivity of the CLIA was about 10 times higher than that of the hemagglutination inhibition test, although it was slightly inferior to that of the enzyme-linked fluorescence assay. Moreover, the time course of light emission from the labeled antibody was rapid, and therefore in the CLIA the quantitation of the marker takes only a short time.
New provisional serovar (E10163) of Shigella boydii
Authors: Gross R J , Thomas L V , Rowe B
Published: January 2020

Eleven bacterial strains are described which give the biochemical reactions characteristic of the genus Shigella but do not belong to any of the established or provisional serovars. The strains are biochemically and serologically indistinguishable, and it is proposed that they be regarded as members of a new provisional serovar of Shigella boydii. Strain E10163 is designated as the test strain for this new serovar.
Frequency-pulsed electron capture gas-liquid chromatography and the tryptophan color test for rapid diagnosis of tuberculous and other forms of lymphocytic meningitis
Authors: Brooks J B , Edman D C , Alley C C , Craven R B , Girgis N I
Published: January 2020

A total of 260 samples of cerebrospinal fluid received from Egypt, the United States, Canada, and South America were examined by frequency-pulsed electron capture gas-liquid chromatography (FPEC-GLC) for tuberculous and other forms of lymphocytic meningitis. Thirty-four of the specimens were culture positive for M. tuberculosis, and four cerebrospinal fluid specimens of herpes meningitis were established by immunological techniques. The compound, 3-(2'-ketohexyl)-indoline, was found in about 60% of the Egyptian tuberculous specimens and none of the culture-positive American specimens. the carboxylic and hydroxy acid FPEC-GLC profiles were used effectively in conjunction with other clinical data to make the diagnosis even in the absence of 3-(2'-ketohexyl)indoline. Herpes meningitis and mixed infections of Myeobacterium tuberculosis-herpes, M. tuberculosis-leptospira, and M. tuberculosis-Haemophilus influenzae produced profiles different from each other and from pure culture cases. The color test for tuberculous meningitis was evaluated, and free tryptophan was eliminated as the source of color reaction. Indications are that 3-(2'-ketohexyl)indoline, in most cases, is not responsible for the positive color reaction. Differences in the clinical and FPEC-GLC data obtained from samples from different geographical regions are discussed.
Rapid typing of herpes simplex virus isolates by deoxyribonucleic acid:deoxyribonucleic acid hybridization
Authors: Brautigam A R , Richman D D , Oxman M N
Published: January 2020

A method for typing clinical isolates of herpes simplex virus was developed. It utilizes hybridization between unlabeled deoxyribonucleic acid from infected cultures and tritium-labeled virus deoxyribonucleic acid, and it can be completed within a day using a single roller-tube culture of the clinical isolated. The data obtained are inherently quantitative, and the method yields unequivocal identification and typing. Thirty-nine coded clinical isolates were all correctly typed by this method.
Four methods for identification of gram-negative nonfermenting rods: organisms more commonly encountered in clinical specimens
Authors: Appelbaum P C , Stavitz J , Bentz M S , von Kuster L C
Published: January 2020

Four commercial kits, Oxi/Ferm (OF), API 20E (AP), Minitek (MT; BBL Microbiology Systems), and Flow N/F (NF), were evaluated, without additional tests, for identification of 258 gram-negative nonfermentative rods. OF and MT were read after 48 h of incubation, and AP and NF were read after both 24 and 48 h of incubation, respectively. Overall, OF correctly identified 51% of strains, with 46% as part (but not first) of a spectrum of identifications (SI), and 3% incorrect species identification. MT yielded 85% correct identification, with 15% SI. Of 126 glucose-positive strains, or those with greater than or equal to 3 positive AP reactions after 24 h, 60% were correctly identified, with 40% SI; incubation for an additional 24 h raised the rate of correct identification to 99%, with 1% SI. A total of 132 strains yield less than 3 positive AP reactions after 24 h and were identified after 48 h only; of these, 82% were correctly identified, with 17% SI and 1% incorrect species identification. NF correctly identified 79% of cultures after 24 h, with 21% SI; corresponding figures after an additional 24 h of incubation were 80% and 20%, respectively. All four commercial methods show promise; OF is easiest to inoculate, but requires extra tests for optimal identification. AP reliably identifies the majority of clinically important nonfermenters, with fairly good species identification of saccharolytic strains after 24 h. MT yields reliable identification of most nonfermenters and has the advantage of flexibility. NF is easy to inoculate, yields satisfactory identification rates, and may be read after 24 h of incubation.
Growth of Paracoccidioides brasiliensis yeast phase in a chemically defined culture medium
Authors: Restrepo A , Jiménez B E
Published: January 2020

A slight modification of the chemically defined medium of McVeigh and Morton resulted in an excellent substratum for the cultivation of Paracoccidioides brasiliensis yeast phase.
Aberrant strain of group G Neisseria meningitidis
Authors: Uyeda C T , Maruyama M M , Hakes M S
Published: January 2020

A glucose-negative group B strain of Neisseria meningitidis isolated from a meningitis case is described. A brief review of Neisseria identification procedures is also presented.
Production of phenylacetic acid by strains of Bacteroides asaccharolyticus and Bacteroides gingivalis (sp. nov.)
Authors: Kaczmarek F S , Coykendall A L
Published: January 2020

Strains of Bacteroides asaccharolyticus and Bacteroides melaninogenicus subspecies isolated from human and animal sources were examined for the production of phenylacetic acid. B. asaccharolyticus strains isolated from sites in humans and monkeys always produced phenylacetic acid. B. asaccharolyticus strains isolated from human nonoral sites consistently failed to produce this product. This metabolic difference correlates with the genetic dichotomy recently found to exist between oral and nonoral B. asaccharolyticus strains.
Production of p-hydroxyhydrocinnamic acid from tyrosine by Peptostreptococcus anaerobius
Authors: Lambert M A , Moss C W
Published: January 2020

Peptostreptococcus anaerobius was found to metabolize tyrosine to p-hydroxyhydrocinnamic acid [3-(p-hydroxyphenyl)propionic acid]. This acid was detected in spent growth media by gas-liquid chromatography, and its identity was confirmed by mass spectrometry.
Evaluation of Urea-motility-indole medium for recognition and differentiation of Salmonella and Shigella species in stool cultures
Authors: Rosa Fraile M , Vega Aleman D , Fernandez Gutierrez C
Published: January 2020

A semisolid urea-motility-indole medium designed for detection in Enterobacteriaceae of urease activity, motility, and indole production in one tube was prepared and evaluated. The formulation of the medium was similar to that of Christensen urea agar, but the agar concentration was 0.2%, and 1% tryptone was added. Results with 687 strains of Enterobacteriaceae were the same as those obtained with standard test media (98% overall agreement). The urea-motility-indole medium was also used in combination with Kligler iron agar for the recognition and differentiation of Salmonella and Shigella species from colonies picked from plating media in fecal cultures. This combination was compared with the combination of Kligler iron agar and lysine iron agar with 507 strains of non-lactose-fermenting Enterobacteriaceae. Although both combinations enabled the presumptive recognition and differentiation of Salmonella and Shigella species, an analysis of data indicated that the combination of Kligler iron agar and urea-motility-indole medium performed better than the combination of Kligler iron agar and lysine iron agar in detecting Salmonella and Shigella species.
Isolation of Actinobacillus lignieresii and Actinobacillus equuli from laboratory rodents
Authors: Lentsch R H , Wagner J E
Published: January 2020

Actinobacillus lignieresii and Actinobacillus equuli were cultured from a total of 36 guinea pigs, rats, and mice. The organisms were isolated from the oropharynx, the conjunctiva, and middle ear. Isolates were initially screened by eight biochemical tests to determine whether they were of the genus Actinobacillus. Actinobacillus spp. were then differentiated by fermentation reactions of nine carbohydrates. In the past, actinobacilli may have been mistakenly identified as Pasteurella spp., especially Pasteurella pneumotropica. The importance of realizing that Actinobacillus spp. are frequently isolated from laboratory rodents was stressed.
Analysis of three variables in sampling solutions used to assay bacteria of hands: type of solution, use of antiseptic neutralizers, and solution temperature
Authors: Larson E L , Strom M S , Evans C A
Published: January 2020

Tests were performed using the sterile bag technique to determine the effects of type of sampling solution, use of antiseptic neutralizers, and solution temperature on the detection and quantitation of bacteria on hands. Using paired hand cultures, three sampling solutions were compared: quarter-strength Ringer solution, a phosphate buffer containing Triton X-100, and the same buffer containing antiseptic neutralizers. The phosphate buffer containing Triton X-100 was significantly better than quarter-strength Ringer solution in mean bacterial yield; the neutralizer-containing sampling solution was slightly better than Triton X-100-containing solution, although differences were not significant at the P = 0.05 level. Temperature (6 or 23 degrees C) of the sampling solution showed no consistent effect on bacterial yield from hands tested with the fluid containing neutralizers.
Clinical laboratory evaluation of the Abbott MS-2 automated antimicrobial susceptibility testing system: report of a collaborative study
Authors: Thornsberry C , Anhalt J P , Washington J A , McCarthy L R , Schoenknecht F D , Sherris J C , Spencer H J
Published: January 2020

The MS-2 system (Abbott Diagnostics, Division of Abbott Laboratories, Dallas, Tex.) was evaluated for its efficacy in determining the susceptibilities of both clinical and selected challenge (nonfastidious, facultative, and aerobic) isolates. The MS-2 results were compared with standard Kirby-Bauer disk diffusion and microdilution results by using fresh clinical isolates. For gram-positive isolates other than enterococci, overall agreement between MS-2 and reference results was 93 to 98%. With enterococci, MS-2 agreement with disk diffusion was 68% but with microdilution was 86% (agreement between disk diffusion and microdilution was 73%). The main discrepancies with enterococci were with cephalothin, penicillin, gentamicin, and kanamycin. With clinical gram-negative isolates, the overall agreement was 91 to 93%, with most discrepancies occurring with Enterobacter spp. and beta-lactam antibiotics (MS-2 versus disk diffusion, 84%; MS-2 versus microdilution, 84%; disk diffusion versus microdilution, 87%) and with Serratia spp. and colistin (false-susceptible results). The agreement of MS-2 results with established reference antibiograms of a special collection of challenge strains was 91 to 97% for the gram-positive cocci and 86 to 98% for the gram-negative strains. (With Enterobacter spp., agreement was 86%, but was greater than 90% for all other organism groups.) Of the 98 finite MS-2 minimum inhibitory concentrations (MICs) that could be directly compared with microdilution MICs, 77 (79%) were within +/- 1 well of the geometric mean microdilution MIC. MS-2 analysis time ranged from 2.8 to 6.5 h (mean, 4.2 h). On the basis of these results, we conclude that the MS-2 can be expected to yield rapid and accurate results with most nonfastidious, facultative, and aerobic pathogens.
Chlamydial antigens stabilized with formalin for use in the micro-immunofluorescence test
Authors: Hanna L , Keshishyan H
Published: January 2020

Formalinized antigen suspensions prepared by differential centrifugation from crude infected yolk sacs and stored at 4 degrees C were satisfactory antigens during at least 36 weeks when used in chlamydial micro-immunofluorescence procedures.
Protease production by clinical isolates of type III group B streptococci
Authors: Straus D C , Mattingly S J , Milligan T W , Doran T I , Nealon T J
Published: January 2020

Six strains of serotype III group B streptococci isolated from confirmed cases of neonatal disease were examined for their ability to produce proteolytic enzymes. Three neuraminidase-producing strains and three non-neuraminidase-producing strains were employed in this study. Protease production was examined in 1,000-fold concentrated filtrates of stationary-phase cells with an insoluble substrate derived from horse hide powder labeled covalently with Remazol brilliant blue. Protease activity was not detected in any cultural supernatant fluids until they were fractionated on Sephadex G-100. After fractionation, the neuraminidase-producing strains were shown to elaborate approximately sixfold more protease than the non-neuraminidase-producing strains. The finding that clinical isolates of group B streptococci that elaborated high levels of neuraminidase also produced elevated levels of extracellular protease may indicate that the production of several different factors may determine the virulence of these organisms.
Separation of immunoglobulin M (IgM) essentially free of IgG from serum for use in systems requiring assay of IgM-type antibodies without interference from rheumatoid factor
Authors: Johnson R B , Libby R
Published: January 2020

The proposed method was designed to replace the tedious and difficult separation of immunoglobulin M (IgM) from IgG by sucrose gradient sedimentation. In this method, a 250-microliter portion of serum diluted 20-fold was passed through a small column of quaternary aminoethyl-Sephadex A-50 ion exchanger. IgG was not retained, but additional washes were required to remove all but 5%. A second buffer-eluting fluid recovered an average of 80% of the original IgM in a defined dilution. The entire operation took 15 min. The efficiency of this process was evaluated by the following: (i) radial immunodiffusion measurements of IgG and IgM; (ii) recovery studies of isohemagglutinins; and (iii) demonstrated removal of interference by the rheumatoid factor. The method was applied successfully to distinguish rubella IgM antibody.
Ecological distribution of Fusarium solani and its opportunistic action related to mycotic keratitis in Cali, Colombia
Authors: Cuero R G
Published: January 2020

Corneal ulcera in patients treated at the University Hospital Cali, Colombia have been attributed to the fungus Fusarium solani, which was isolated from patients' eyes by deep scraping. The fungus, which was characterized by culture and morphology, was found to grow well at 37 degrees C in Sabouraud and potato dextrose agars and in liquid asparagine medium, in which it produced very few spores; at 40 degrees C, it survived for 3 weeks. Different levels of pathogenicity were shown by the fungus when 3-week-old bean, corn, and tomato plants were inoculated. Controlled experiments in which an inoculum of F. solani was instilled in rabbit eyes were also carried out; it evoked a clinical reaction producing irritation and erythema. The F. solani isolated from eyes was the same species as that isolated by an agar plate method with Fusarium-selective medium from sugar cane, bean, tomato, or corn fields throughout December 1976 to November 1977. Nonfarming areas and urban sites were also air sampled, but only a few (less than 1%) colonies of F. solani were isolated at one of four sites. A preliminary attempt to identify the physiologically active substance of the fungus was carried out through chemical extraction, thin-layer chromatography, and ultraviolet and infrared spectra analysis.
Infectivity of human coronavirus strain 229E
Authors: Macnaughton M R , Thomas B J , Davies H A , Patterson S
Published: January 2020

The replication of human coronavirus strain 229E was observed by using indirect immunofluorescence in infected monolayers of MRC continuous cells. By 8 h after infection, bright cytoplasmic fluorescence was detected in cells infected with human coronavirus 229E. Discrete foci of infection were observed from 8 to 16 h after infection in cells infected with high dilutions of human coronavirus 229E; each fluorescent focus corresponded to a single virus infection. A fluorescent focus assay is described, using indirect immunofluorescence, which is more sensitive than the established techniques of tube titration and plaque assay. Particle/infectivity ratios for unpurified and purified virus preparations revealed a considerable drop in infectivity on purification.
Radiometric detection of mycobacteria in routine blood cultures
Authors: Landau W , Feczko J , Kaplan R L
Published: January 2020

Mycobacterium chelonei subsp. abscessus was detected radiometrically in routine blood cultures. The organism was detected in two patients without the use of special mycobacteriological media.
Positive Limulus amoebocyte lysate reactions with polyriboinosinic acid x polyribocytidylic acid
Authors: Elin R J , Utter A E
Published: January 2020

The annealed copolymer polyriboinosinic acid x polyriboinosinic acid reacted with Limulus amoebocyte lysate to cause gelation at a concentration approximately 2,000-fold or greater than bacterial endotoxins. This copolymer was pyrogenic in rabbits and demonstrated hypochromicity, but no significant correlation was noted among Limulus amoebocyte lysate reactivity, progenicity, and hypochromicity. Like endotoxin, polyriboinosinic acid x polyribocytidylic acid did not react with purified Limulus coagulogen. Similar concentrations of the homopolymers polyriboinosinic acid and polyribocytidylic acid were negative or significantly below the Limulus amoebocyte lysate reactivity of the copolymear and essentially nonpyrogenic. Thus, polyriboinosinic acid x polyribocytidylic acid is a compound in addition to endotoxin that effects a positive Limulus amoebocyte lysate test.
Clinical evaluation of automated antibiotic susceptibility testing with the MS-2 system
Authors: Barnes W G , Green L R , Talley R L
Published: January 2020

The MS-2 (Abbott Laboratories) system for automated antimicrobial susceptibility testing was evaluated for both accuracy and general utility in our clinical laboratory. A total of 984 fresh clinical bacterial isolates (745 gram-negative, 239 gram-positive) were tested with the MS-2 system, and results were compared directly with those from a conventional agar disk diffusion method. Discrepancies between the two methods were categorized as very major, major, and minor. For gram-positive isolates, full accord (all discrepancies considered) was 91.6%, and essential accord (minor discrepancies not included) was 96.2%. With gram-negative isolates, full accord was found to be 93.9%, with essential accord of 97.9%. Aggrement as a function both of organism group and of antimicrobial agent was determined. Full accord of 90% or more was found for all major organism groups tested, with the exception of enterococci, where discrepant results between the two methods were observed. Mean test time for all isolates tested was 4.3 h. The MS-2 was found to be an accurate and highly automated instrument which required minimal technician time and was readily adaptable to work flow in our clinical laboratory.
Evaluation of the Four-Hour Micro-ID Technique for Direct Identification of Oxidase-Negative, Gram-Negative Rods from Blood Cultures
Authors: Appelbaum Peter C. , Schick Suzanne F. , Kellogg James A.
Published: January 2020

A 4-h Micro-ID technique for direct identification of oxidase-negative gram-negative rods from positive blood cultures was compared to subculture and species identification of single colonies by API 20E and Micro-ID, using standardized inocula. A total of 127 patients (220 positive cultures) were studied. Isolates included 96
Escherichia coli
, 46
Klebsiella pneumoniae
, 7
Klebsiella oxytoca
, 8
Enterobacter aerogenes
, 17
Enterobacter cloacae
, 19
Serratia marcescens
, 2
Serratia liquefaciens
, 8
Proteus mirabilis
, 1
Salmonella
species, 1
Morganella morganii
, 6
Haemophilus influenzae
, 2
Haemophilus parainfluenzae
, 3
Bacteroides fragilis
, 3
Acinetobacter calcoaceticus
biotype
anitratus
, and 1
Pseudomonas maltophilia
. In 90% of the cultures, identification by Micro-ID was identical to that obtained after subculture; if the 15 non-enterobacterial isolates were excluded, the corresponding figure was 96.6%. Enterobacteria identified incorrectly by direct Micro-ID were three
S. marcescens
(two identified as
S. liquefaciens
, one as
Hafnia alvei
), two
S. liquefaciens
(both identified as
E. cloacae
), and two
K. pneumoniae
(one identified as
Klebsiella ozaenae
, the other as
Serratia rubidaea
). None of the 15 non-enterobacterial cultures were correctly identified by Micro-ID (non-identifiable, or classified as
Providencia/Yersinia/Klebsiella
species). Although biochemical discrepancies between direct and final Micro-ID tests occurred in 41% of the enterobacterial cultures, this did not seriously interfere with identification. Direct species identification of
Enterobacteriaceae
from blood cultures by direct Micro-ID is accurate and easily performed and identified organisms within 4 h compared to at least 24 h by most other methods; the direct Micro-ID technique would be rendered even more valuable by the additional capability of identifying non-enterobacterial gram-negative isolates.
Evaluation of cefamandole susceptibility testing of Enterobacteriacea by the autobac 1 system
Authors: de Girolami P C , Maher L A , Booth M T , St George D M
Published: January 2020

A total of 509 clinical isolates of Enterobacteriaceae were tested for susceptibility to cefamandole by Autobac 1 and Bauer-Kirby disk diffusion methods, using commercially available 30-micrograms cefamandole disks. Minimal inhibitory concentrations were determined for all organisms showing major or very major discrepancies. Overall agreement between Autobac 1 and disk diffusion was 89.8%, with 5.1% major or very major and 5.1% minor discrepancies. When considering only the genera for which 20 or more isolates were tested, overall agreement was 90.8%. Discrepancies for Escherichia coli showed a trend toward resistance by Autobac 1, with minimal inhibitory concentrations generally in agreement with disk diffusion results. No trends were detected for other genera. The rate of agreement was lower for Enterobacter species (75.4%), but minimal inhibitory concentrations, determined for all discrepancies in this genus, agreed with Autobafc 1 as often a with disk diffusion results.
Anticomplement immunofluorescence test that uses isolated fibroblast nuclei for detection of antibodies to human cytomegalovirus
Authors: Mintz L , Miner R C , Yeager A S
Published: January 2020

Cytomegalovirus antibodies were measured in human sera by a nuclear anticomplement immunofluorescence test that used as antigen the isolated nucleic of virus-infected fibroblasts cells lysed in distilled water. The method exhibited less nonspecific fluorescence than either a conventional whole-cell anticomplement immunofluorescence test or an indirect fluorescent antibody test applied to the same isolated nuclear substrate. The assay detected 97.5% of 40 antibody-positive sera, compared with 92.5 and 90% detection rates by indirect hemagglutination and complement fixation, respectively. In addition, antibody titers obtained by this technique were significantly higher than those obtained by either indirect hemagglutination (P < 0.02) or complement fixation with a glycine-extract antigen (P < 0.001).
Role of Infectious Secretions in the Transmission of Rhinovirus
Authors: Pancic F. , Carpentier D. C. , Came P. E.
Published: January 2020

In a series of studies aimed at investigating the role of environmental surfaces in the transmission of certain respiratory virus infections, it was shown that small amounts of nasal mucus containing rhinovirus (infectious mucus) can spread from fingertips to door knobs, faucet handles, or other environmental surfaces and remain infectious for many hours. These surfaces can serve as a reservoir of virus and may provide sufficient infectious material to contaminate hands. Recent studies have shown that once virus is on the fingers, it may be transferred to the nasal and conjunctival mucosa by means of autoinoculation. It has been estimated that as little as 1.0 plaque-forming unit can produce an infection in a susceptible human. In the present experiments, the amount of rhinovirus transmitted from fingers contaminated with infectious mucus to environmental surfaces and from there onto the fingers of a volunteer who touched the contaminated objects was quantitated, and the efficiency of transfer was studied. From 3 to 1,800 plaque-forming units of rhinovirus were recovered from the fingertips of volunteers (recipients) who handled either a door knob or a faucet that had previously been manipulated by another volunteer (donor) whose fingers were contaminated with infectious mucus. The average amount of rhinovirus recovered from the fingers of the recipients was approximately 13.5% of the amount recoverable from the fingers of the donor. In experiments in which there was direct hand-to-hand contact between donor and recipient, about 6.7% of the virus present on the fingertips of donors was recoverable from the recipients.
Extracellular neuraminidase production by clinical isolates of group B streptococci from infected neonates
Authors: Mattingly S J , Milligan T W , Pierpont A A , Straus D C
Published: January 2020

A total of 73 clinical isolates of group B streptococci obtained from diseased infants in 23 states and Puerto Rico were examined for extracellular neuraminidase production. The association of elevated levels of neuraminidase with serotype III isolates was evident in a broad geographical distribution.
Direct immunofluorescence staining for detection of herpes simplex and varicella-zoster virus antigens in vesicular lesions and certain tissue specimens
Authors: Schmidt N J , Gallo D , Devlin V , Woodie J D , Emmons R W
Published: January 2020

Direct immunofluorescence (IF) staining was compared with virus isolation for detection of herpes simplex viruses (HSV) and varicella-zoster virus (VZV) directly in clinical materials. These included 199 vesicular lesion specimens and 280 tissue specimens. Correspondence between IF and isolation results was 88% in testing for HSV in lesion specimens and 98% in testing for HSV in various tissue (mostly brain) specimens. Overall, IF was positive for 82% of the specimens in which HSV was demonstrated, and virus was isolated from 89% of the HSV-positive specimens. IF was markedly more sensitive than isolation for demonstrating VZV in lesion and tissue specimens, detecting all of the specimens positive for VZV, whereas isolation detected only 23%. IF detected VZV antigen in a number of lesion specimens taken late after onset, past the time when they would be expected to yield infectious virus. Specificity of positive IF reactions for HSV or VZV in the absence of virus isolation was supported by the facts that (i) staining was obtained with only a single, presumably homologous, immune conjugate, (ii) clinical symptoms were compatible with infection with the virus for which positive IF findings were obtained, and (iii) positive electron microscopy findings for herpesviruses or positive serological results for VZV were also obtained in some instances. Factors to be considered in achieving specificity of IF staining for these human herpesviruses are discussed.
Comparison of direct wet mount and trichrome staining techniques for detecting Entamoeba species trophozoites in stools
Authors: Gardner B B , Del Junco D J , Fenn J , Hengesbaugh J H
Published: January 2020

Simulated freshly passed stools containing motile Entamoeba moshkovskii trophozoites were examined by direct wet mount and permanent (Trichrome) staining techniques. The percentage of detection by direct mount was 4.8%. The percentage of detection of the trophozoites by direct mount plus permanent stain was 58.5%. Laboratorians should be cautioned not to rely solely on the direct wet mount for detection or identification of protozoan trophozoites.
Enzyme-Linked Immunosorbent Assay for Immunoglobulin G Antibody to Encephalomyocarditis Virus
Authors: Shanley John D.
Published: January 2020

An enzyme-linked immunosorbent assay for immunoglobulin G antibody to encephalomyocarditis virus was developed. This assay was comparable to antibody assay by neutralization. Its adaptability should be useful for laboratory and epidemiological studies of infections due to encephalomyocarditis virus.
Inactivation of rabies diagnostic reagents by gamma radiation
Authors: Gamble W C , Chappell W A , George E H
Published: January 2020

Treatment of CVS-11 rabies adsorbing suspensions and street rabies infected mouse brains with gamma radiation resulted in inactivated reagents that are safer to distribute and use. These irradiated reagents were as sensitive and reactive as the nonirradiated control reagents.
Evaluation of the MS-2 system for rapid identification of Enterobacteriaceae
Authors: McCracken A W , Martin W J , McCarthy L R , Schwab D A , Cooper B H , Helgeson N G , Prowant S , Robson J
Published: January 2020

The precision, accuracy, and other performance characteristics of the MS-2 (Abbott Laboratories, Diagnostic Division, Dallas, Tex.) system for the identification of Enterobacteriaceae were evaluated in a collaborative study involving three clinical laboratories. When identifying 150 unknown, coded organisms, the MS-2 system was 97%, 98%, and 93% accurate, respectively, in three laboratories. The system showed an overall accuracy of 94% when compared with conventional manual tube methods in identifying 1,154 clinical isolates of 26 species of Enterobacteriaceae. Discrepancies between automated and conventional methods were chiefly caused by biochemical variants, especially among Enterobacter species. The MS-2 system was rapid and simple to operate and produced printed results of bacterial identification in 5 h. The cost of disposable components compared favorably with commercial, visually read systems for identifying Enterobacteriaceae.
Effect of Various Blood Culture Media on Lysostaphin Sensitivity of Staphylococci
Authors: Severance Perry J. , Kauffman Carol A. , Sheagren John N.
Published: January 2020

A rapid screening test for
Staphylococcus aureus
that utilizes lysostaphin sensitivity was found to be reliable for organisms cultured in 12 different commercial blood culture media.
Potential hazards associated with microbial contamination of in-line filters during intravenous therapy
Authors: Holmes C J , Kundsin R B , Ausman R K , Walter C W
Published: January 2020

The survival and multiplication of Enterobacter agglomerans, Klebsiella pneumoniae, Serratia marcescens, and Pseudomonas aeruginosa in 0.45- and 0.22-micrometer in-line filter sets during simulated infusions were studied to evaluate the ability of each filter type to prevent infusions of these bacteria into patients. Bacteria were found to proliferate in the upstream compartment of sets housing both filter porosities. None of the 0.22-micrometer in-line filters were penetrated by the test bacteria. In contrast, P. aeruginosa was observed to penetrate each 0.45-micrometer in-line filter examined within 12 h of continuous infusion. Tribe Klebsielleae organisms penetrated a proportion of the 0.45-micrometer filters usually between 48 and 72 h of infusion. In addition, the elution of endotoxin from gram-negative bacteria trapped in the filter set during infusion is reported. Collected infusion filtrate exhibited a trend of increasing endotoxin-like activity with an increasing duration of infusion. In the case of E. agglomerans, mean peak levels of approximately 65 pg of Escherichia coli endotoxin per ml were attained after 72 h. Other bacteria produced similar results, except mean peak levels ranged from 5 to 30 pg/ml. It was noted that endotoxin-like activity was not detected in filtrate eluted from contaminated filter sets during the initial 24 h of infusion. We conclude that to avoid potential hazards of bacterial penetration and endotoxin production during continuous use of in-line filter sets, the 0.22-micrometer filter type must be employed and replaced every 24 h.
Slide method for detection of antibody-coated bacteria in urine sediments
Authors: Matuscak R R , Pasculle A W , Barnhart L , Atchison R W , Yee R B
Published: January 2020

An immunofluorescent slide method incorporating 0.1% (wt/vol) Evans blue as a counterstain was developed and compared with a recently described tube method. Seventy-one urine specimens were tested concurrently by both methods. Results of the two methods agreed in 70 specimens and disagreed in only 1. We found the slide method to be less costly and time consuming than the tube method.
Varicella-zoster-associated encephalitis: detection of specific antibody in cerebrospinal fluid
Authors: Gershon A , Steinberg S , Greenberg S , Taber L
Published: January 2020

Varicella-zoster (VZ) antibody measured by indirect immunofluorescence was used to identify patients with encephalitis due to VZ virus. In 15 of 16 (94%) patients with VZ infection and clinical evidence of central nervous system involvement, VZ antibody was present at a titer of 1:2 or greater in cerebrospinal fluid. In contrast, no VZ antibody was detected in the cerebrospinal fluid of seven patients with VZ infections without clinical signs of central nervous system involvement, nor was any detected in the cerebrospinal fluid of 25 patients with malignant or demyelinating disease or encephalitis due to other viral or toxic agents. All of these patients had detectable serum VZ antibody. Thus, in this study the presence of detectable VZ antibody in cerebrospinal fluid measured by indirect immunofluorescence seemed to correlate with clinical evidence of central nervous system involvement due to this virus.
Rapid detection of Clostridium difficile toxin in human feces
Authors: Ryan R W , Kwasnik I , Tilton R C
Published: January 2020

Fifty fecal specimens were tested by three methods, bacterial isolation, counterimmunoelectrophoresis, and tissue culture, for Clostridium difficile and its toxin. Ten specimens (20%) were positive by all three methods. An additional eight specimens were toxin positive only by counterimmunoelectrophoresis. Although counterimmunoelectrophoresis and tissue culture are of equivalent sensitivity, the additional dilution necessary for tissue culture assay may be critical when only small concentrations of toxin are present.
Inhibition of Lancefield Group D Enterococci by Contamination of a Commercial Identification Medium with Paraffins
Authors: Butts Jeff , Dees Craig
Published: January 2020

A commercially available system for the identification of streptococci was found to incorrectly identify group D enterococci due to contamination of the 6.5% NaCl medium with paraffins.
Enzyme-Linked Immunosorbent Assay for Detection of Immunoglobulin M Antibodies Against
Toxoplasma gondii
Authors: Duermeyer W. , Wielaard F. , Van Gruijthuijsen H. , Swinkels J.
Published: January 2020

A new principle that uses anti-immunoglobulin M-coated polystyrene microtiter plates for the detection of immunoglobulin M antibodies against
Toxoplasma gondii
by an enzyme-linked immunosorbent assay was developed.
Room temperature storage of Legionella cultures
Authors: Hébert G A
Published: January 2020

Charcoal-yeast extract agar slant cultures of Legionella representing all four named species were stored at room temperature in the dark. Some L. pneumophila strains survived 2 months, L. bozemanii and L. dumoffii strains were viable at 4 months, and L. micdadei strains remained viable after 1 year in storage.
Modified Elek test for detection of heat-labile enterotoxin of enterotoxigenic Escherichia coli
Authors: Honda T , Taga S , Takeda Y , Miwatani T
Published: January 2020

The Elek test was modified for detection of the heat-labile enterotoxin of enterotoxigenic Escherichia coli. A total of 164 strains of E. coli were tested by the modified Elek test, and the results correlated well with those of the Chinese hamster ovary cell assay and passive immune hemolysis. It is concluded that the modified Elek test is a simple and reproducible assay method for identification of E. coli which produce heat-labile enterotoxin, and is suitable for use in clinical laboratories.
Surface colonies of Leptospira interrogans
Authors: Wood J , Johnson R C , Palin K
Published: January 2020

Observations of colonial growth of Leptospira interrogans serovar pomona, BJ, on soft-agar (1% agar) plates revealed the presence of both surface and subsurface colonies. The organisms from both types of colonies appeared to be similar in motility, morphology, antigenic composition, and pathogenicity. Passage in vivo tended to produce a higher incidence of surface colonies, whereas passage in vitro tended to produce a higher incidence of subsurface colonies, suggesting the importance of environmental factors in determining the type of colony produced.
Improved Serodiagnosis of
Salmonella
Enteric Fevers by an Enzyme-Linked Immunosorbent Assay
Authors: Beasley William J. , Joseph Sam W. , Weiss Emilio
Published: January 2020

The value of the enzyme-linked immunosorbent assay (ELISA) for the serological diagnosis of typhoid or paratyphoid fevers was tested with a collection of five sets of sera from 23 individuals who had no history of
Salmonella
infection from a nonendemic area (set 1) and from 143 patients from a highly endemic area (sets 2 to 5). The test was performed with a crude cell envelope fraction derived from
Salmonella typhi.
On the basis of results with sera in set 1, titers >160 (inverse of serum dilution) for immunoglobulin M (IgM) or >500 for IgG were regarded as signifying a specific antibody response. These titers were occasionally exceeded in sera in set 2, derived from patients with no clinical or laboratory evidence of
Salmonella
infection. In presumptive cases of typhoid or paratyphoid fevers (culture positive and agglutination negative or vice versa; 13 patients, set 3, and 26 patients, set 4, respectively), IgG antibodies were encountered more frequently than IgM, but some sera were negative in each group. In 81 confirmed cases (culture and agglutination positive, set 5) IgG antibodies were detected in at least one of the paired sera from all patients, and the IgG titers were higher (median 3,500) than those of the IgM antibodies (median 600). There was no evidence of a significant difference in IgM or IgG titers between acute- and convalescent-phase sera. The titers of 10 paired sera from patients from whom
S. enteritidis
, bioserotype paratyphi A, was isolated were somewhat lower than those of 84 patients with
S. typhi
isolation (serogroup D). There was some correlation between O antigen agglutination and IgM enzyme-linked immunosorbent assay, but otherwise the titers in the two serological tests varied independently. Of 11 patients in set 3 (2 patients with serogroup B agglutinins omitted), 1 belonged to blood group O, in contrast to 54 group O among 107 agglutination-positive patients, a distribution not necessarily reflected by the enzyme-linked immuno-sorbent assay. This study has provided good evidence that the enzyme-linked immunosorbent assay can serve as a valuable aid to the diagnosis of
Salmonella
infection in an endemic area, as a substitute for the agglutination test.