bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of Legionella pneumophila capsular-like envelope antigens by counterimmunoelectrophoresis
Authors: Smith R A , DiGiorgio S , Darner J , Wilhelm A
Published: January 2020

The capsular-like envelope of Legionella pneumophila strains Togus 1 (serotype 2) and Philadelphia 1 (serotype 1) was isolated and purified by column chromatography on Sepharose 6B. Antibody raised in rabbits to these two antigenic materials did not cross-react in gel diffusion. Upon electrophoresis followed by gel diffusion, the majority of both envelope materials was found to migrate towards the cathode. A minor antigenic component of each envelope only migrated slightly towards the anode. Using the envelope antigens and the two anti-envelope sera in a counterimmunoelectrophoresis (CIE) assay, positive results were only obtained when the antigenic materials were placed in the cathodal well. The Togus 1 and Philadelphia 1 antigens did not cross-react in CIE. The sensitivity of the CIE assay was poor (15.6 micrograms/ml by carbohydrate content) compared to its sensitivity in other microbial systems. Although CIE may not be a useful diagnostic aid in identifying Legionella species due to its low sensitivity, it may be of value in serotyping the microorganism since we did not see cross-reactivity between the two strains when anti-envelope sera were used.
Simple standardized enzyme-linked immunosorbent assay for human antibodies to Entamoeba histolytica
Authors: Lin T M , Halbert S P , Chiu C T , Zarco R
Published: January 2020

A simple solid-phase enzyme-linked immunosorbent assay procedure for the detection of human antibodies to Entamoeba histolytica was developed which showed a high degree of correlation with the agar gel diffusion, counterelectrophoresis, and indirect hemagglutination methods, as well as with clinical data. The enzyme-linked immunosorbent assay is rapid (1 h 15 min, total incubation time), and the reported values are referenced to a positive control so that they correlate with levels of antibody sufficient to be detected by the gel diffusion methods. The enzyme-linked immunosorbent assay is highly reproducible, specific, and sensitive; it can be used qualitatively or quantitatively.
Detection of yeast septicemia by biphasic and radiometric methods
Authors: Prevost E , Bannister E
Published: January 2020

From January 1977 to April 1980 our microbiology laboratory used a commercial biphasic brain heart infusion vented culture method for fungal blood cultures and a commercial radiometric (BACTEC 460, Johnson Laboratories, Cockeysville, Md.) method for bacterial blood cultures. A total of 668 biphasic fungal blood cultures were processed, of which 30 grew yeasts from 19 patients. There were 38,324 BACTEC blood cultures processed for bacteria, of which 184 grew yeasts from 85 patients. The overall detection time for all yeasts averaged 8.3 days for the biphasic method and 2.4 days for the radiometric method. The BACTEC aerobic bottle detected over six times as many yeasts as did the anaerobic bottle. Candida albicans was the most frequently isolated yeast in both methods, being detected in an average of 7.7 days in the biphasic method and 1.6 days in the aerobic BACTEC bottle. It is concluded from this study that the radiometric method is far superior to the biphasic method, because (i) it has a shorter detection time, (ii) it can be used simultaneously with bacterial methods, saving blood and money, and (iii) it requires no special or separate media or instructions for yeasts, thus alleviating confusion in the blood collection process.
New medium selective for Fusobacterium species and differential for Fusobacterium necrophorum
Authors: Morgenstein A A , Citron D M , Finegold S M
Published: January 2020

Fusobacterium egg yolk agar is a new medium selective for Fusobacterium species and differential for Fusobacterium necrophorum. The medium is a Brucella Agar base (Difco Laboratories, Detroit, Mich.) containing vancomycin, neomycin, josamycin, and egg yolk. All species of fusobacteria grew with only minimal inhibition. The mean log difference in counts between Fusobacterium egg yolk agar and control media for 30 strains of seven species of fusobacteria was 0.1922. F. necrophorum typically showed a strong lipase reaction. Most other organisms were significantly inhibited by the medium.
Diagnosis of recent rubella virus infection by demonstration of specific immunoglobulin M antibodies: comparison of solid-phase reverse immunosorbent test with sucrose density gradient centrifugation
Authors: Denoyel G A , Gaspar A , Peyramond D
Published: January 2020

A solid-phase reverse immunosorbent test (SPRIST) based on the addition of an excess of rubella virus hemagglutinin was evaluated for the demonstration of rubella-specific immunoglobulin M (IgM), and the results were compared with those of the density gradient centrifugation technique. In a retrospective study in which 157 sera were tested, the two techniques yielded identical results (55 IgM-positive and 102 IgM-negative samples). In a prospective study, 592 sere were examined; 8 IgM-positive results by SPRIST corresponded to a recent rubella infection or vaccination. Neither rheumatoid factor nor heterophil antibody seemed to interfere with the results of SPRIST. This test would be a useful and rapid routine technique for demonstration of the presence of virus-specific IgM in serum samples, particularly for viruses with a hemagglutinin. Except for anti-human IgM, no more reagents are needed than for widely used hemagglutination inhibition procedures.
Efficacy of various cell culture procedures for detection of Chlamydia trachomatis and applicability to diagnosis of pediatric infections
Authors: La Scolea L J , Keddell J E
Published: January 2020

In this study, 5-iodo-2'-deoxyuridine-, cytochalasin B-, and cycloheximide-treated and untreated McCoy cells were inoculated with representative strains of Chlamydia trachomatis serotypes, as well as with clinical specimens from a pediatric population, and the quality and quantity of the cytoplasmic inclusions were examined. Cycloheximide treatment consistently rendered the highest number of quality inclusions per milliliter of any method tested for both the laboratory strains (P less than 0.001) and the clinical isolates (P less than 0.01). The inclusion counts in untreated McCoy cells were either higher than or not significantly different from those in 5-iodo-2'-deoxyuridine- an cytochalasin B-treated cells. However, the quality of the inclusions, using the criteria of size, brightness, and ease of detection produced in untreated and 5-iodo-2'-deoxyuridine-treated cells, was inferior to the quality of those obtained by other procedures. Cells treated with cytochalasin B had the best-quality inclusions as compared with those treated by any other method. It is recommended from our experience that for overall sensitivity and simplicity cycloheximide treatment is the method of choice for isolation of C. trachomatis in McCoy cells.
Immunofluorescence staining for detection of variola virus
Authors: Tarantola D J , Huq F , Nakano J H , Foster S O
Published: January 2020

In September 1975 Bangladesh was the only country in the world with endemic variola major, and the eradication of the disease was imminent. A rapid and accurate laboratory diagnostic method was required to supplement immunodiffusion in agar gel and culture on chorioallantoic membrane of embryonated egg available at the Institute of Public Health in Dacca, Bangladesh. To determine its effectiveness, a new, improved immunofluorescence (IF) staining technique was introduced. Laboratory specimens (scabs or vesicular or pustular impressions) were collected from patients who had, or were suspected of having, smallpox. Seventy-eight of 144 specimens collected were found to be IF positive for smallpox. As the number of laboratory-positive cases far exceeded the number of clinically diagnosed smallpox cases, IF-positive cases were reinvestigated and subsamples of the IF-positive specimens were tested at a World Health Organization poxvirus reference laboratory at the Centers for Disease Control in Atlanta, Ga. The results indicated 100% sensitivity for the IF technique (no false-negative results) in diagnosing variola major but also showed a high rate of false-positive results. Consequently, IF could not be recommended as a routine screening test for smallpox.
Detection of Yersinia enterocolitica heat-stable enterotoxin by suckling mouse bioassay
Authors: Nunes M P , Ricciardi I D
Published: January 2020

A comparison of heat-stable enterotoxins from Escherichia coli and Yersinia enterocolitica by the suckling mouse bioassay showed that whereas E. coli heat-stable enterotoxin evoked a maximum ratio of gut weight to remaining body weight after a 4-h incubation period, the maximum ratio for Y. enterocolitica was achieved at 2 h, decreasing thereafter to values regarded as negative (less than 0.083). This action of Y. enterocolitica heat-stable enterotoxin may give false-negative results for the standard suckling mouse bioassay.
Production of deoxyribonuclease, ribonuclease, coagulase, and hemolysins by anaerobic gram-positive cocci
Authors: Marshall R , Kaufman A K
Published: January 2020

Clinical isolates of Peptococcus and Peptostreptococcus species and Streptococcus intermedius strains were obtained from local hospitals. After confirmed identification, each isolate was tested for the in vitro production of deoxyribonuclease, ribonuclease, coagulase, and hemolysins. Of the 60 strains studied, 18 had enzymatic activity. The variability of enzyme production suggests that such assays are not suitable as an aid to identification of these organisms.
Evaluation of transport methods for isolating Shigella spp
Authors: Wells J G , Morris G K
Published: January 2020

Recovery of Shigella spp. from fecal specimens transported in buffered glycerol saline and Cary-Blair media held at frozen, refrigerated, or room temperature was compared with recovery by direct plating of fecal specimens. Buffered glycerol saline was the better transport medium for the recovery of Shigella spp. Refrigerated or frozen transport temperatures were superior to room temperature for recovery from either medium.
Improved Lyophilization Procedure for Storage of Reference Cultures and Clinical Isolates
Authors: Alexander Gary A.
Published: January 2020

A capillary lyophilization technique was devised as a simple means for storage of replicate cultures. This technique was evaluated over a 1-year period, utilizing 18 different strains.
Pseudomonas denitrificans
Meningitis
Authors: Fischer Robert A. , Doern Gary V. , Cheeseman Sarah H.
Published: January 2020

An elderly male patient with
Pseudomonas denitrificans
bacteremia and meningitis is described. The antimicrobial susceptibility and minimum criteria necessary for the identification of this unusual and rare human pathogen are discussed.
Comparison of enzyme-linked immunosorbent assay and hemagglutination test using mycobacterial glycolipids
Authors: Reggiardo Z , Vazquez E
Published: January 2020

Enzyme-linked immunosorbent assay and hemagglutination methods were compared using mycobacterial glycolipids as antigens. Both methods were found to have equivalent specificity and sensitivity in detecting mycobacterial diseases. Both tests had 96% specificity; the sensitivity of the enzyme-linked immunosorbent assay was 86%, and that of the hemagglutination test was 88.6%.
Nonspecific reactions in the hemagglutination inhibition test for detection of rubella antibodies
Authors: Budzko D B , Jelinek D F , Wilcke B W
Published: January 2020

Approximately 7% of the sera tested to determine the presence of rubella-specific antibodies by the hemagglutination inhibition test demonstrated abnormal patterns of reactivity, rendering the test unreadable. Another 3% of sera were shown to have false-positive titers as high as 1:128. When these abnormally reacting and false-positive sera were heated at 56 degrees C for 30 min after chemical treatment they always converted to negative, indicating the absence of specific rubella hemagglutination-inhibiting antibody. These results were confirmed by fractionation of the sera after sucrose gradient centrifugation. It was established that manifestation of these nonspecific results was dependent on the concentration of Ca2+ or Mn2+. The heat-labile inhibitor(s) responsible for abnormal and false-positive reactions was found not to be complement. This inhibitor(s) was detected in the light fractions of sera and when added to negative sera was capable of reproducing the abnormal patterns of reactivity. These results emphasize the necessity of heating sera for the rubella hemagglutination inhibition test after the chemical removal of nonspecific inhibitors.
Commercial simian virus antisera that inhibit virus replication in primary monkey kidney cell cultures
Authors: Hughes J H , Hamparian V V
Published: January 2020

The incorporation of hyperimmune serum into cell culture medium to control endogenous viral infections of primary cells can have a significant effect on the replication of other viruses. When commercial simian virus 5 or simian virus 40 antiserum was used with primary monkey kidney cell cultures, we found a significant inhibition (greater than 90%) of the replication of parainfluenza virus types 2 and 3 and reovirus type 1. In the viral diagnostic laboratory, the use of hyperimmune serum with primary monkey kidney cells may result in failure to isolate certain viruses if these cells are not first washed free of hyperimmune serum.
Safety of maintaining intravenous sites for longer than 48 H
Authors: Birnbaum D W
Published: January 2020

Two years of experience with infections in intravenous (IV) therapy were studied through cohort analysis of infection surveillance records. The overall rate of infection was low compared with other published reports, but the risk of infection was related to the duration of cannulation. IVs in place for no more than 48 h accounted for 75% of all IVs and 26% of IV-associated infections, those in place for 48 to 72 h accounted for 12.5% of IVs and 23% of IV-associated infections, and those in place in excess of 72 h accounted for 12.5% of IVs, but 51% of IV-associated infections. Septicemia was associated with site infection in 20% of cases. This application of routinely obtained infection surveillance data demonstrates the ability of comprehensive surveillance programs to facilitate administrative decisions and to document subsequent quality of patient care.
Rapid and sensitive method for quantitation of Legionella pneumophila serogroup 1 antigen from human urine
Authors: Mangiafico J A , Hedlund K W , Knott A R
Published: January 2020

A reversed passive hemagglutination test was developed to assay relative concentrations of soluble antigen of Legionnaires disease (Legionella pneumophila serogroup 1) in human urine samples. The test is highly sensitive, being able to detect as little as 0.0002 microgram of total antigen. Preliminary results with this test on serial urine and serum samples from a patient with legionellosis show that measurable amounts of antigen are present in urine during the course of the illness. However, no antigen could be detected in the serum of the patient.
Fatal salmonellosis originating in a clinical microbiology laboratory
Authors: Blaser M J , Lofgren J P
Published: January 2020

Laboratory-acquired infections concern all microbiologists. During ongoing surveillance of laboratory-acquired enteric infections, salmonella infections in the wife and son of a laboratory worker were documented; the first case was fatal. Neither patient had had any contact with the laboratory. The infecting organisms were Salmonella typhi and a multiply resistant strain of Salmonella agona that were being worked within the laboratory; both strains had been received 1 to 2 years previously for proficiency testing exercises. This report documents the transmission of enteric pathogens beyond the confines of the laboratory, with its tragic outcome, and suggests measures to prevent the recurrence of this problem.
Sensitive hemagglutination inhibition test for mumps antibody
Authors: Albrecht P , Klutch M
Published: January 2020

Incorporation of heterologous immunoglobulin against human immunoglobulin G into the mumps HI tests provided a highly sensitive and specific way of measuring mumps antibody in human sera. The sensitivity of this enhanced mumps HI test compared favorably with that of an anti-immunoglobulin-enhanced virus plaque neutralization test, but the HI test required considerably less time and effort to perform.
Formation of nonspecific precipitants in sera by counterimmunoelectrophoresis
Authors: Chan J K , Folds J D
Published: January 2020

Formation of nonspecific precipitants in sera in different kinds of agarose and batches of barbital buffer by routine counterimmunoelectrophoresis was observed. These nonspecific precipitants consistently locating at the cathodal side of the well upon counterimmunoelectrophoresis can lead to the incorrect interpretation that a specific antibody is present in the patient's serum against the antigens tested. This observation indicates the importance of including a negative control (patient's serum alone) with each individual sample tested by counterimmunoelectrophoresis for the detection of specific antibody to reduce false-positives.
Comparison of formalin-ethyl ether sedimentation, formalin-ethyl acetate sedimentation, and zinc sulfate flotation techniques for detection of intestinal parasites
Authors: Truant A L , Elliott S H , Kelly M T , Smith J H
Published: January 2020

Formalin-ethyl ether sedimentation, Formalin-ethyl acetate sedimentation, and zinc sulfate flotation techniques were compared using over 250 clinical parasitology specimens. Fifty positive specimens were identified, and a variety of parasites, including amoebae, flagellates, cestodes, nematodes, and trematodes, were encountered. The Formalin-ether and Formalin-ethyl acetate sedimentation procedures gave identical results for the detection of cysts, ova, and larvae, and these methods offered an advantage over the flotation procedure for the detection of selected ova. However, the zinc sulfate procedure was more effective for the detection of protozoan cysts, Hymenolepis nana, and hookworm eggs. The results indicate that the Formalin-ethyl acetate procedure provides a suitable alternative to the Formalin-ether method, and they demonstrate the value of using both flotation and sedimentation procedures in the analysis of fecal specimens for parasites.
Infections due to Yersinia enterocolitica serotypes O:2,3 and O:4 acquired in South Florida
Authors: Chester B , Sanderson T , Zeller D J , Pestana O A
Published: January 2020

Four recent cases of Yersinia enterocolitica infections from Florida are discussed. Two of the cases presented as acute mesenteric lymphadenitis, and the other two presented as septicemia. Three of the isolates were an uncommon serotype, O:2,3, and the fourth was serotype O:5. The increasing occurrence of Y. enterocolitica in semitropical areas of the United States is emphasized.
Choice and specificity of complement in complement fixation assay
Authors: Sethi J , Pei D , Hirshaut Y
Published: January 2020

This study examines the relative activity of various complement sources in a variety of antigen-antibody (Ag-Ab) complement fixation assay systems. Studied were Ag-Ab systems of cytomegalovirus, adenovirus, Pneumococcus, Coccidiodes, and guinea pig kidney. Ab titers in each system were determined by microcomplement fixation assay using two batches of titrated rabbit, monkey, cat, dog, human cord, human adult, and guinea pig sera as complement sources. Assay sensitivity and Ab titers proved to be strongly related to the complement sources. There was considerable variation in the ability of Ag-Ab complexes to bind the complement of each of the species tested. Guinea pig, rabbit, and monkey sera gave comparable titers in four of the five Ag-Ab systems tested. Cat serum complement was able to detect anti-adenovirus and anti-Pneumococcus reactivity only. Human adult, human cord, and dog sera exhibited anti-complementary activity. The study emphasizes the importance of complement source in determining both the specificity and sensitivity of complement fixation assays in a given Ag-Ab system.
Comparison of direct electron microscopy, immune electron microscopy, and rotavirus enzyme-linked immunosorbent assay for detection of gastroenteritis viruses in children
Authors: Brandt C D , Kim H W , Rodriguez W J , Thomas L , Yolken R H , Arrobio J O , Kapikian A Z , Parrott R H , Chanock R M
Published: January 2020

An approximate 10% suspension in water of the first available stool sample from 411 infants and young children with acute gastroenteritis was examined by electron microscopy (EM) after 2 min of negative staining. This procedure enabled the detection of 88% of the 199 rotavirus infections, all of the 22 adenovirus infections, and 47% of the 15 approximately 27-nm virus infections ultimately detected by a combination of techniques, including immune electron microscopy (IEM) and rotavirus enzyme-linked immunosorbent assay (ELISA). Of the 204 infections detected by direct EM of stools, 76% were detected within 2 min of viewing, and 94% were detected within 6 min of viewing. Type 1 and type 2 rotavirus particles were visualized with approximately equal efficiency, although type 2 rotavirus infections were more common. Rectal swab preparations were clearly inferior to stool preparations for the detection of virus infection by direct EM. IEM examination was required for efficient visualization of viruses in rectal swab specimens. ELISA was the most sensitive method for the detection of rotaviruses; with this method, all infections in which rotavirus particles were visualized by EM or IEM were detected. However, 73% of the 1,834 specimens which were presumptively positive for rotavirus by conventional indirect ELISA proved to be falsely positive on the basis of EM, IEM, blocking ELISA, confirmatory ELISA, or a combination of these methods. False-positive rotavirus ELISA reactions apparently were eliminated when fecal specimens were tested in a modified confirmatory ELISA with a lower dilution of rotavirus-negative (pre-immunization) than rotavirus-positive (post-immunization) capture antibody from the same animal.
Simple, New Test for Rapid Differentiation of the
Mycobacterium fortuitum
Complex
Authors: Casal Manuel J. , Rodriguez Fernando C.
Published: January 2020

A simple, new test to differentiate species in the
Mycobacterium fortuitum
complex by determining susceptibility to pipemidic acid is described. A 20-μg pipemidic acid disk provides a rapid and reliable means of distinguishing
M. fortuitum
from
M. chelonei
.
Immunoglobulin E anti-Staphylococcus aureus antibodies in atopic patients
Authors: Walsh G A , Richards K L , Douglas S D , Blumenthal M N
Published: January 2020

Sera from 56 patient and normal adults were examined to quantitate total immunoglobulin E (IgE) and IgE antibodies to Staphylococcus aureus and Staphylococcus epidermidis. Patients were divided into six groups based on clinical symptoms; a seventh group consisted of normal adults. Anti-S, aureus IgE binding was significantly higher in three groups of patients (those with eczema, those with or without series staphylococcal abscesses, and allergic patients with staphylococcal skin infections) than it was in the control group. Patients with high IgE due to allergies or parasitic infections without staphylococcal infections and patients with low or normal IgE and serious staphylococcal infection showed low levels of binding. The assay measured specific binding of IgE to bacterial antigens.
Quantitation of antibodies to Haemophilus influenzae type b in humans by enzyme-linked immunosorbent assay
Authors: Dahlberg T
Published: January 2020

The enzyme-linked immunosorbent assay was adapted to detect serum immunoglobulin G, immunoglobulin M, immunoglobulin A, and secretory immunoglobulin A antibodies to Haemophilus influenzae type b capsular polysaccharide in humans. I studied serum samples from 92 healthy children of various ages, 50 healthy adults, 24 patients with various H. influenzae type b infections, and 16 patients with clinical signs of epiglottis and cellulitis suspected to be caused by H. influenzae type b. The mean antibody titers of the sera from healthy children increased with age and reached adult levels in children more than 6 years old. A significant antibody response to capsular polysaccharide was observed in serum samples from the majority of patients with infections due to H. influenzae type b and in 4 of 16 patients with clinical signs of epiglottis and cellulitis. In addition to the enzyme-linked immunosorbent assay, the antibody responses of patients were tested by a bactericidal assay. When the two methods were compared, there was no evident correlation (r, about 0.22). The enzyme-linked immunosorbent assay was further adapted to test secretory immunoglobulin A antibodies specific to capsular polysaccharide in nasopharynx secretions and in milk samples from lactating women. Antibodies were detected in 12 of 24 secretions and 9 of 11 milk samples.
Antibiotic resistance in Providencia stuartii isolated in hospitals
Authors: McHale P J , Keane C T , Dougan G
Published: January 2020

A total of 238 isolates of Providencia stuartii obtained from infected patients in six Dublin hospitals were grouped by using serological and bacteriocin typing methods and tested for sensitivity to a number of antimicrobial agents. Most isolates were resistant to several of these agents. Resistance to tetracycline, resistance to penicillin, resistance to polymyxin, and probably resistance to nitrofurantoin was intrinsic. Plasmid screening coupled with resistance transfer studies showed that both chromosome-encoded and plasmid-coded resistance mechanisms were clinically important. Ampicillin resistance was both chromosomally and plasmid encoded, whereas resistance to kanamycin and resistance to carbenicillin were exclusively plasmid encoded. Gentamicin resistance was more common than kanamycin resistance, and although gentamicin-resistant strains contained aminoglycoside acetyltransferase activity, no association could be demonstrated with plasmid deoxyribonucleic acid in the strains tested. Unlike minimal inhibitory concentrations for kanamycin, minimal inhibitory concentrations for gentamicin varied over a wide range. P. stuartii isolated obtained from several different countries were tested for comparison. As a group, these strains were less resistant, but they did exhibit similar resistance properties.
Rapid oxidase method for testing oxidase-variable Aeromonas hydrophila strains
Authors: Hunt L K , Overman T L , Otero R B
Published: January 2020

A rapid, same-day oxidase test procedure which obviates the problem of false-negative oxidase reactions of Aeromonas hydrophila removed from the surface of differential media such as MacConkey agar is described. This method allows oxidase testing to be performed within 3 h, rather than delaying the oxidase test for an additional 18 to 24 h. This procedure is applicable to any rapidly growing gram-negative rod.
Enhancement of recovery of Neisseria meningitidis by gelatin in blood culture media
Authors: Pai C H , Sorger S
Published: January 2020

The efficacy of gelatin for the recovery of Neisseria meningitidis from blood cultures was evaluated in a clinical setting. The organism was isolated from seven patients with meningococcal infections in blood culture media containing 1% gelatin. In contrast, only two blood cultures from these patients were positive in media without gelatin (P less than 0.05). Gelatin did not influence the recovery of other organisms isolated during this study. Conventional blood culture media may be supplemented with gelatin when meningococcemia is suspected.
Determination of brucella immunoglobulin G agglutinating antibody titer with dithiothreitol
Authors: Klein G C , Behan K A
Published: January 2020

The routine brucella agglutination test measures both immunoglobulin M (IgM) and IgG brucella antibody titers; however, only an elevated IgG titer is significant for differentiating active from inactive disease in patients with symptoms lasting 3 or more weeks. The IgG antibody titer can be determined by treating the serum wih 2-mercaptoethanol to inactivate the IgM brucella antibodies while leaving the IgG brucella antibodies intact. Dithiothreitol, which also inactivates IgM, was compared with 2-mercaptoethanol for the determination of IgG brucella agglutination titers. The dithiothreitol and 2-mercaptoethanol test results agreed within +/- 1 dilution step in 103 of 105 serum specimens tested, for a 98.1% rate of agreement. The results indicate that dithiothreitol can be used in place of 2-mercaptoethanol for determining IgG brucella agglutination titers. Dithiothreitol does not have the offensive odor or the irritant properties of 2-mercaptoethanol.
Relative frequency of Clostridium difficile in patients with diarrheal disease
Authors: Gilligan P H , McCarthy L R , Genta V M
Published: January 2020

We have studied 161 patients with diarrheal disease to determine the frequency with which Clostridium difficile occurs in such patients. C. difficile or its toxin or both were detected in stools from 19 patients (11.9%), 17 of whom had previously received antimicrobial agents. Enteric pathogens other than C. difficile were recovered less frequently, with Salmonella sp., Giardia lamblia, and Campylobacter fetus being recovered from 4.1, 2.5, and 1.3%, respectively, of the patients studied. These data suggest that C. difficile may be frequently encountered in specimens obtained from patients with diarrhea who receive antibiotics and may play a role in diarrheal disease in such patients.
Measurement of immunoglobulin M, immunoglobulin G, and immunoglobulin A antibodies against Yersinia enterocolitica by enzyme-linked immunosorbent assay: comparison of lipopolysaccharide and whole bacterium as antigen
Authors: Granfors K , Viljanen M K , Toivanen A
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) for the detection and quantitation of human immunoglobulin M (IgM), IgG, and IgA antibodies against Yersinia enterocolitica by using lipopolysaccharides as antigens is described. The results obtained with the lipopolysaccharide ELISA were compared with the results of the whole bacterium ELISA. The correlations observed were good for each immunoglobulin class. Cross-reactions between Y. enterocolitica serotypes O:3 and O:9, Yersinia pseudotuberculosis IA, and Brucella abortus were studied by human and rabbit antisera in the whole bacterium and lipopolysaccharide ELISAs and by rabbit antisera using ELISA inhibition. The greatest cross-reactivity observed was that of the anti-Brucella serum with Y. enterocolitica O:9 in the whole bacterium ELISA. In the lipopolysaccharide ELISA this cross-reaction was not demonstrable with the rabbit antiserum, but it was strong with the human antiserum. However, differential diagnosis was possible with ELISA inhibition. On the basis of our experience, we are now routinely using whole bacterium ELISA for the determination of class-specific Yersinia antibodies, and potential cross-reactions are controlled by the ELISA inhibition.
Quality control limits for ampicillin, carbenicillin, mezlocillin, and piperacillin disk diffusion susceptibility tests: a collaborative study
Authors: Gavan T L , Jones R N , Barry A L , Fuchs P C , Gerlach E H , Matsen J M , Reller L B , Thornsberry C , Thrupp L D
Published: January 2020

A multilaboratory in vitro study was carried out to determine disk diffusion susceptibility testing quality control limits for two new semisynthetic penicillins, mezlocillin and piperacillin. Existing limits for carbenicillin and ampicillin were reevaluated. Multiple tests (which followed standards set by the National Committee for Clinical Laboratory Standards ASM-2 revised) were performed in nine laboratories by different technologists using disks and Mueller-Hinton agar from different manufacturers. Clinically significant differences between disks produced by different manufacturers were not noted. Inhibitory zone diameter measurements from all laboratories were analyzed, and upper and lower control limits were established by using the overall median +/-0.5 the median range of the individual laboratory measurements as determining parameters. Close agreement of the data in this study with the results of national proficiency testing and quality control programs for ampicillin and carbenicillin supports the validity of our approach to making initial recommendations for quality control guidelines for new antimicrobial agents.
Comparison of enzyme-linked immunosorbent assay for acute measles with hemagglutination inhibition complement fixation, and fluorescent-antibody methods
Authors: Kleiman M B , Blackburn C K , Zimmerman S E , French M L
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) using commercially available reagents was compared with standard serological tests for determination of antibody titers in patients with acute measles. The measles-specific ELISA was as sensitive as complement fixation, hemagglutination inhibition, and indirect fluorescent-antibody methods. The ELISA method used was simple, sensitive, inexpensive, and reproducible and may conveniently be used in a small clinical laboratory.
Improved detection of viruses by electron microscopy after direct ultracentrifuge preparation of specimens
Authors: Hammond G W , Hazelton P R , Chuang I , Klisko B
Published: January 2020

We have adapted the Beckman Airfuge air turbine ultracentrifuge and the new EM-90 particle-counting rotor to improve detection by electron microscopy of viruses in clinical specimens. Samples were clarified by centrifugation, pelleted in the EM-90 rotor directly to Formvar-coated copper grids, and strained with 1.5% sodium phosphotungstate. Virus counts and endpoint titrations of serial dilutions of partially purified preparations of poliovirus, SA11 rotavirus, herpes simplex virus, and vaccinia virus showed an increase of ca. 1.5 log10 to 3.0 log10 over the virus titers of unconcentrated preparations of the same material. An increased yield of 14% more positive specimens for rotavirus was obtained after preparation of clinical samples by direct ultracentrifugation versus a method without virus concentration (82 versus 72). A prospective study showed that detection of adenoviruses, herpesviruses, and enteroviruses increased when specimens were prepared by direct ultracentrifugation. Direct ultracentrifugation with the EM-90 rotor in the Airfuge ultracentrifuge is a rapid concentration method which enhances the rate and yield of virus detection from clinical specimens by electron microscopy and is easily adaptable to a diagnostic virology laboratory.
Exoantigen test for identification of Petriellidium boydii cultures
Authors: Morace G , Polonelli L
Published: January 2020

Cultures of Petriellidium boydii were serologically identified by detection of their exoantigens with an immunodiffusion procedure. The technique, which is specific and sensitive, allowed the rapid identification and differentiation of 12 isolates of P. boydii from numerous other morphologically similar Hyphomycetes. The antigen-antiserum reference system and the production, by two different techniques, of exoantigens used in the identification of P. boydii are described.
Difference in antibody reactivity between complement fixation and immune adherence hemagglutination tests with virus antigens
Authors: Inouye S , Matsuno S , Kono R
Published: January 2020

Complement-fixing (CF) immunoglobulin M antibody to infantile gastroenteritis virus (a rotavirus) did not show the reactivity of immune adherence hemagglutination (IAHA). Early immunoglobulin G CF antibody produced both in patients and in guinea pigs experimentally infected with Japanese encephalitis virus (a flavivirus) had weak reactivity in IAHA test. However, late antibody showed higher titers by IAHA than by CF. These results suggested that early antibodies with lower affinity are inefficient in the IAHA reaction. The implications of this study are: (i) a low ratio of IAHA/CF antibody titers in a serum suggests a recent rotavirus infection; (ii) the IAHA reaction is more type specific than the CF reaction for identifying the serotype of antigenically cross-reacting viruses with hyperimmune sera.
Evaluation of blood culture media for isolation of pyridoxal-dependent Streptococcus mitior (mitis)
Authors: Gross K C , Houghton M P , Roberts R B
Published: January 2020

Nutritional variant streptococci identified as pyridoxal-dependent Streptococcus mitior (mitis) account for 5 to 6% of streptococcal endocarditis and may be a cause of "culture-negative" endocarditis. Hence, growth of three variant strains in 11 commercial blood culture broths was compared to that in fresh heart infusion broth. For simulation of clinical specimens, culture bottles were injected with 5 ml of human blood, inoculated with approximately 500 colony-forming units (CFU) per bottle, and monitored for 7 days with Gram stains and viable counts. Only Thiol broth (Difco Laboratories, Detroit, Mich.) supported growth without blood at this low inoculum. In media containing blood, maximal growth of 10(9) CFU/ml was reached within 2 days of incubation, and heavy turbidity was consistently observed in only heart infusion broth, Thiol broth, and media supplemented with pyridoxal hydrochloride. Columbia broth (BBL Microbiology Systems, Cockeysville, Md.) with increased cysteine, thioglycollate broth, and one brain heart infusion broth produced moderate growth (1 x 10(8) to 5 x 10(8) CFU/ml), whereas Columbia broth, another brain heart infusion broth, and two brands of tryptic soy broth showed fair growth (1 x 10(7) to 4 x 10(7) CFU/ml). The poor growth (1 x 10(6) to 3 x 10(6) CFU/ml) observed in three other brands of tryptic soy broth was often not apparent macroscopically or by Gram stain. Furthermore, on growth occurred in 40% of tryptic soy broth cultures inoculated with 50 CFU. Therefore, to ensure isolation of these variant streptococci from clinical blood cultures, a medium containing thiol compounds or supplemented with pyridoxal should be used. Subcultures should be made within 2 days of incubation to blood agar enriched with pyridoxal or containing a Staphylococcus sp. streak for satellitism.
Rapid, simple method of preparing rotaviral double-stranded ribonucleic acid for analysis by polyacrylamide gel electrophoresis
Authors: Theil K W , McCloskey C M , Saif L J , Redman D R , Bohl E H , Hancock D D , Kohler E M , Moorhead P D
Published: January 2020

A procedure for extracting rotaviral double-stranded ribonucleic acid (RNA) directly from fecal and intestinal specimens collected from calves and pigs is described. This procedure provides a rapid, simple, reproducible method of obtaining rotaviral double-stranded RNA preparations suitable for electrophoretic analysis in polyacrylamide-agarose composite gels. The rotaviral genome electrophoretic migration pattern produced by double-stranded RNA extracted directly from a specimen by this procedure was qualitatively identical to the electrophoretic migration pattern obtained with double-stranded RNA extracted from purified rotavirus derived from the same specimen. Direct extraction of specimens containing porcine rotavirus-like virus by this procedure gave preparations that had electrophoretic migration patterns similar, but not identical, to the characteristic electrophoretic migration pattern of the rotaviral genome. Sufficient rotaviral double-stranded RNA could be extracted from 6 ml of fecal or intestinal specimen by this procedure to permit 15 or more electrophoretic assays.
Improved semiselective medium for isolation of Legionella pneumophila from contaminated clinical and environmental specimens
Authors: Edelstein P H
Published: January 2020

Eighteen types of media, all of which used charcoal yeast extract medium as a base, were tested for their ability to support the growth of a stock strain of Legionella pneumophila. Fifteen of these contained antimicrobial agents. Five antibiotic-containing media which performed best in growing the stock strain were then tested for the ability to grow L. pneumophila from clinical respiratory tract specimens. One of the media, BMPA alpha, which contained cefamandole, polymyxin B, anisomycin, an organic buffer, and alpha-ketoglutarate, performed from contaminated clinical specimens and, in conjunction with an acid wash treatment, facilitated recovery of the bacterium from potable water.
Characteristics of Yersinia enterocolitica and related species isolated from human, animal, and environmental sources
Authors: Shayegani M , DeForge I , McGlynn D M , Root T
Published: January 2020

During a 4-year period, 4,448 human, animal, and environmental samples collected in New York State were tested for the presence of Yersinia enterocolitica or related species. A total of 339 isolates were identified as Yersinia and characterized according to source, species, biogroup, serogroup, and, in some instances, phage type. Four new biogroups of Y. intermedia were characterized. Of 149 human isolates, 120 (80.5%) were identified as Y. enterocolitica, and 29 were identified as either Y. intermedia (12.1%), Y. frederiksenii (5.4%), or Y. kristensenii (2.0%). Of the other 190 isolates, recovered from animals and the environment, 54 (28.4%) were Y. enterocolitica and 136 were either Y. intermedia (62.6%), Y. frederiksenii (4.7%), Y. kristensenii (3.7%), or an undescribed Yersinia species (0.5%). Two established human pathogenic strains of Y. enterocolitica were recovered: 59 isolates (37 from an outbreak) of "American strain" (serogroup O:8, biogroups Niléhn 2, Wauters 1, and Knapp and Thal 2, phage type Xz) and 11 isolates of "Canadian strain" (serogroup O:3, biogroups Niléhn 4, Wauters 4, and Knapp and Thal 1, phage types IXb). This was the first documented isolation of the Canadian strain in the United States. Isolates of other strains implicated in human disease (serogroups 0:4,33, 0:5, O:6,31, O:7,8, and O:8) were also recovered from both human and nonhuman sources.
Clinical evaluation of the rapid carbohydrate degradation microtube method for identification of Neisseria species
Authors: Qadri S M , Parker N
Published: January 2020

The rapid carbohydrate degradation (Carr Microbiologicals Wichita, Kans.) microtube method is a new test system designed for the identification of Neisseria spp. The system consists of four microtubes containing different carbohydrates in a peptone-Bitone basal medium. This method was evaluated for accuracy and speed in identifying species of Neisseria. Of the 386 clinical isolates used in this study, 98.4% were correctly identified to species level in 4 h with the rapid carbohydrate degradation system; parallel testing of the same isolates with conventional cystine-tryptic agar resulted in 96.1% accuracy in 48 h.
Detection of cell-associated or soluble antigens of Legionella pneumophila serogroups 1 to 6, Legionella bozemanii, Legionella dumoffii, Legionella gormanii, and Legionella micdadei by staphylococcal coagglutination tests
Authors: Wilkinson H W , Fikes B J
Published: January 2020

Current methods used for the detection of whole-cell isolates of Legionella or for the detection of Legionella soluble antigens are technically impractical for many clinical laboratories. The purpose of this study was to explore practical alternatives. The results showed that whole cell isolates of Legionella pneumophila serogroups 1 to 6, Legionella bozemanii, Legionella dumoffii, Legionella gormanii, and Legionella micdadei were identified specifically by a simple slide agglutination test or slide coagglutination test in which the reagent antisera are first bound to staphylococcal protein A. Soluble antigens were also identified specifically by the slide coagglutination test and by a sandwich immunofluorescence assay. The latter test may be useful in detecting antigen in body fluids of patients with legionellosis or in environmental samples.
Growth of nutritionally variant streptococci on common laboratory and 10 commercial blood culture media
Authors: Reimer L G , Reller L B
Published: January 2020

Nutritionally variant streptococci fail to grow on routine sheep blood agar plates. Moreover, these strains are a recognized cause of culture-negative endocarditis. We tested the ability of chocolate and brucella blood agars, sheep blood agar with a staphylococcal streak, sheep blood agar with 0.001% pyridoxal, and 10 commercial blood culture media from two manufactures to grow these bacteria. Of the original 25 strains tested, 16 were recovered on chocolate agar, 21 were recovered on brucella blood agar and 21 were recovered on sheep blood agar with a staphylococcal streak. Sheep blood agar with pyridoxal grew all 22 strains tested. Supplemented peptone, thioglycolate, and thiol broths grew all strains, but brain heart infusion and three tryptic soy broths supported five or fewer strains. The addition of 5 ml of human blood improved recovery to 100% in all media except tryptic soy broths. Unless supplemented wih pyridoxal, common laboratory agars were inadequate for recovering all strains of variant streptococci upon subculture of blood culture bottles. As used clinically, the blood culture media that we studied other than tryptic soy broths should reliably grow these bacteria.
Effect of Refrigeration on Inoculated Micro-ID Strips
Authors: Burdash Nicholas M. , West Marcia E.
Published: January 2020

Since reading results after 4 h with the Micro-ID system is not always convenient, a study of 500 isolates indicated that identification at the species level is essentially unchanged when inoculated strips are refrigerated overnight and then incubated or incubated and then refrigerated overnight before reading.
Bacteriological and serological studies of haemophilus equigenitalis, agent of contagious equine metritis
Authors: Tainturier D J , Delmas C F , Dabernat H J
Published: January 2020

Seventeen strains of haemophilus equigenitalis isolated from the cervix, clitoris, and urethra of mares were biochemically characterized with the API 10E and APIZYM test kit systems, conventional biochemical tests, and the porphyrin test. Antisera were prepared in rabbits. All of the strains were positive to the porphyrin test, and the requirement for factor X (hemin) or V (nicotinamide adenine dinucleotide) was not shown. Catalase, oxidase, phosphatase, and phosphoamidase tests were positive with all of the strains. Aminopeptidase (arylamidase) activity has been detected on beta-naphthylamide derivatives of eight amino acids and of di- and tripeptides. No glycosidase activity was found. Antisera prepared in rabbits strongly agglutinated all H. equigenitalis strains, but none of the various other bacterial strains. These characteristics should prove to be useful in the identification of H. equigenitalis.
Clinical laboratory evaluation of the automicrobic system Enterobacteriaceae biochemical card
Authors: Davis J R , Stager C E , Wende R D , Qadri S M
Published: January 2020

The AutoMicrobic System Enterobacteriaceae Biochemical Card (AMS-EBC; Vitek Systems, Inc.) was evaluated in two clinical microbiology laboratories. A total of 502 consecutive clinical isolates representing members of the family Enterobacteriaceae were tested in parallel with the AMS-EBC, API 20E, and Enterotube II systems. Discrepancies between systems were resolved with the conventional methods of Edwards and Ewing (P. R. Edwards and W. H. Ewing [ed.], Identification of Enterobacteriaceae, 1972) and Ewing and Martin (W. H. Ewing and W. J. Martin, in Manual of Clinical Microbiology, 1974) AMS-EBC correctly identified 96.6% and incorrectly identified 3.4% of the isolates. When 12 or more isolates of a species were evaluated, Serratia marcescens, Proteus mirabilis, and Enterobacter cloacae posed the greatest challenge to the systems, with 92.6, 95.2, and 95.3%, respectively, being correctly identified. To confirm the accuracy of identification when all systems agreed, 93 randomly selected isolates were identified by conventional methods. The percent agreement was 100%. The reproducibility of triplicate determinations on 93 randomly selected isolates with the AMS-EBC was 99.6%. The AMS-EBC was found to be an easy, rapid, and accurate method for identification of Enterobacteriaceae.