bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemically defined medium for Legionella pneumophila growth
Authors: Ristroph J D , Hedlund K W , Gowda S
Published: January 2020

A chemically defined medium containing 18 amino acids, inorganic salts, rhamnose, choline, and ferric pyrophosphate has been developed. The final concentrations of salts and amino acids were modeled after yeast extract. This medium supported the growth of four serogroups of Legionella pneumophila. Growth in shake cultures at 37 degrees C produced a lag time of approximately 5 h and a generation time of 4 h with a maximum growth yield of 10 9 colony-forming units per ml. A soluble brown pigment was observed in the stationary phase of growth. The optimal pH was 6.3. Rhamnose and choline were stimulatory; arginine, serine, threonine, cysteine, valine, and methionine were essential. Supplemental iron was not required to attain maximum growth, but iron deprivation caused an extended lag phase.
Correlation studies of entero-set 20, API 20E and conventional media systems for Enterobacteriaceae identification
Authors: Aldridge K E , Hodges R L
Published: January 2020

The Entero-Set kit (Fisher Diagnostics) is a 20-biochemical-test system used in the identification of members of the Enterobacteriaceae. This kit was compared with the API 20E (Analytab Products) and conventional media systems, using 505 (303 stock and 202 clinical) strains of Enterobacteriaceae. When the Entero-Set and API 20E results were compared with those of the conventional media system, the Entero-Set performed as well as the API 20E in overall identification. Comparison of common biochemical tests among the various systems showed that citrate, arabinose, adonitol, inositol, and malonate gave correlations below 90%. The majority of the discrepancies were found among stock cultures. In addition, most discrepancies occurred with species of Enterobacter, Salmonella, Proteus, Klebsiella, and Serratia. Reproducibility studies showed the Entero-Set system to perform with a high degree of accuracy and reproducibility.
Validation of Legionella pneumophila indirect immunofluorescence assay with epidemic sera
Authors: Wilkinson H W , Cruce D D , Broome C V
Published: January 2020

Sera from six outbreaks of legionellosis and four outbreaks of pneumonia of other etiologies were tested with the indirect immunofluorescence assay (IFA) as currently performed. The current IFA is at least as sensitive as the original test in detecting cases of Legionnaires disease (78 to 91%). By using Center for Disease Control criteria for a positive (fourfold increase in titer during convalescence to greater than or equal to 128) or presumptive (single titer greater than or equal to 256) serological test, the specificity exceeded 99%. No cross-reactions against Legionella pneumophila antigens were observed among sera from epidemic cases of Q fever, tularemia, and psittacosis; the only positive L. pneumophila IFA titer among the epidemic Mycoplasma pneumonia sera was reduced to a negative titer with an immunosorbent extracted from Escherichia coli strain O13:K92:H4. The slight increase in specificity (to 100%), however, was offset by a slight decrease in sensitivity. The sensitivity of the IFA was maximal when a conjugate that detected immunoglobulins G, M, and A was used. IFA titers were not significantly altered by replacing the monovalent serogroup 1 antigen with a polyvalent antigen (serogroups 1 through 4) nor by the presence of rheumatoid factor or heat-labile serum factors.
Rapid screening for bacteriuria by light scatter photometry (Autobac): a collaborative study
Authors: Hale D C , Wright D N , McKie J E , Isenberg H D , Jenkins R D , Matsen J M
Published: January 2020

A total of 2,720 urine specimens from three laboratories were evaluated by Autobac (Pfizer Diagnostics) and were compared with simultaneous colony counts for evidence of bacteriuria. Of 599 specimens with a colony count of greater than or equal to 10(5) colony-forming units per ml, 93.8% were detected within 6 h. This detection rate increased to 97% of 447 positive urine specimens when only specimens from patients not on antimicrobials were evaluated. The majority (77.9%) of positive specimens were detected as early as 3 h. Those specimens with greater than or equal to 10(5) colony-forming units per ml, which were negative by Autobac at 6 h, included organisms which are frequently considered to be contaminants (diphtheroids, lactobacilli, alpha and gamma streptococci, yeasts, and Staphylococcus epidermidis), or were from patients who were being treated with antimicrobial agents. Of 2,121 urine specimens with colony counts of less than 10(5), 98.1% were correctly determined to be negative by Autobac at 3 h. This percentage decreased to 86.0 at 6 h. The majority of these false-positive specimens were those with colony counts of 10(4) to 10(5) colony-forming units per ml. There appeared to be no major difference in results from the three laboratories or among the four lots of broth used in this study.
Accurate automated identification of selected Enterobacteriaceae at four hours
Authors: Ferraro M J , Edelblut M A , Kunz L J
Published: January 2020

The Enterobacteriaceae Biochemical Card of the AutoMicrobic system Vitek Systems, Inc., Hazelwood, Mo.) provides completely automated identification of members of this family within an 8-h test period. Identification of 776 clinical and stock isolates to species level by the Enterobacteriaceae Biochemical Card under routine operating conditions correlated at 96% with our present 18- to 24-h methods of identification. Further, utilizing a special program, we investigated presumptive identification of certain organisms within 4-h--an interval that provides greater practical clinical usefulness on a real-time rapid basis. In a single year, 1978, 97% of 23,464 Enterobacteriaceae isolated in our diagnostic laboratory belonged to 11 species of six genera. Our results suggest that, by limiting the number of the identified Enterobacteriaceae that could be actually presumptively reported to those 11 species of six genera. Our results suggest that, by limiting the number of the identified Enterobacteriaceae that could be actually presumptively reported to those 11 species with the highest frequency of occurrence, we could have correctly identified and presumptively reported 83% of these to genus or species after only 4 h. Approximately 2% of the isolates would have been presumptively identified and reported incorrectly, whereas the identification of the remaining 15% would not have been reported before the completed 8-h incubation period.
Response of several Limulus amoebocyte lysates to native endotoxin present in gonococcal and nongonococcal urethral exudates from human males
Authors: Prior R B , Spagna V A
Published: January 2020

Three Limulus amoebocyte lysate (LAL) preparations obtained from three different suppliers were comparatively evaluated for sensitivity to native endotoxin contained in urethral exudates from 28 men with gonococcal urethritis and 16 men with nongonococcal urethritis. One LAL preparation was not extracted with organic solvents during manufacture, whereas the other two were extracted with chloroform. All three LAL preparations had equivalent sensitivities (0.06 ng/ml) to an established reference endotoxin standard (EC-2), but significant differences in sensitivities were found among the different LAL preparations when testing clinical specimens. Dilution breakpoints of urethral samples for maximum sensitivity and specificity ranged from 1:400 to 1:1,600, depending on the LAL preparation. The nonextracted lysate was significantly more sensitive to the presence of endotoxin in gonococcal exudates than the other two preparations (P less than 0.001) but not significantly different from one LAL preparation (P greater than 0.05) in detecting endotoxin in nongonococcal exudates. An additional 116 men, 61 with culture-proven gonococcal urethritis and 55 with nongonococcal urethritis, were evaluated with three lots of nonextracted lysate with sensitivities ranging from 0.04 to 0.06 ng/ml, reference endotoxin EC-2. At a dilution breakpoint of 1:1,600, the sensitivity of the LAL test was 100%, and the specificity was 96%.
Toxin detection after storage or cultivation of enterotoxigenic with colicinogenic Escherichia coli: a possible mechanism for toxin-negative pools
Authors: Murray B E , Seriwatana J , Echeverria P
Published: January 2020

Of 100 non-enterotoxigenic Escherichia coli isolated from children with diarrhea in Bangkok, Thailand, 24 were found to produce colicin(s). Of these, 87% were active against one or more enterotoxigenic E. coli isolated from the same population. Storage of nine enterotoxigenic E. coli with known inhibitory colicin-producing E. coli in different proportions caused 51 of 96 pools to become negative in the suckling mouse assay (heat-stable toxin) and 17 of 52 to become negative in the Y-1 adrenal cell assay (heat-labile toxin). Cocultivation of the same strains, without prior storage, caused 12 of 96 pools to become negative for heat-stable toxin and 1 of 52 pools to become negative for heat-labile toxin. Storage or cultivation of E. coli in pools may cause negative results in the suckling mouse and Y-1 adrenal cell assays if any of the isolates in the pool produces colicin(s).
Evaluation of the Sceptor microdilution antibiotic susceptibility testing system: a collaborative investigation
Authors: Jones R N , Thornsberry C , Barry A L , Gavan T L
Published: January 2020

A multiwell, dried antimicrobial agent susceptibility test system, Sceptor (BBL Microbiology Systems, Cockeysville, Md.), was tested. The system was compared directly with a reference microdilution method by using two collections of stock cultures and 305 fresh clinical isolates. Sceptor was found to be in agreement (+/- log2 dilution) with the reference microdilution method in 96.9 to 98.3% of 9,840 minimal inhibitory concentration determinations performed on stock strains and 95.0% of 7,308 minimal inhibitory concentrations obtained from the clinical isolates. The intralaboratory and interlaboratory reproducibility on stock strains was 97.6 and 97.2%, respectively. The intralaboratory reproducibility for the clinical isolates was 96.9%. Sceptor accurately categorized representative challenge strains of methicillin-resistant staphylococci, beta-lactamase-producing bacteria, organisms producing other antimicrobial agent-inactivating enzymes, and permeability mutants as resistant. Only 0.2% very major errors (false-sensitive minimal inhibitory concentrations by Sceptor) were identified among the clinical isolate test results, the majority being clinically insignificant. The product is accurate and reliable, has a long shelf life, and seems applicable for routine use in clinical laboratories.
Correlation of Plasmodium falciparum gametocytemia with complement component titers in rural Nigerian school children
Authors: Ade-Serrano M A , Ejezie G C , Kassim O O
Published: January 2020

The relationship between Plasmodium falciparum gametocytemia and the complement components C3, C4, and C3b was investigated in 141 ambulant rural Nigerian school children. Three groups were studied. Group 1 included 42 children with circulating P. falciparum gametocytemia in which the mean titers of C3, C4, and C3b were 145.4 +/- 22.6 mg/100 ml (72%), 60.5 +/- 0.2 mg/100 ml (149%), and 64.0 +/- 5.9 mg/liter (65%), respectively. These findings indicated marked C3b hypocomplementemia. Group 2 included 50 children who were used as controls and lacked malaria parasitemia. C3, C4, and C3b mean titers were 161.6 +/- 28.9 mg/100 ml (80%), 56.8 +/- 2.07 mg/100 ml (140%), and 84.8 +/- 11.4 mg/liter (86%), respectively. Group 3 included 49 children with other blood stages of P. falciparum parasitemia but no gametocytes. C3, C4, and C3b mean titers in this group were 103.0 mg/100 ml (51%), 18.3 +/- 1.2 mg/100 ml (45%), and 90.7 mg/liter (92%), respectively. Our findings suggest that C3b hypocomplementemia may be related to the advent of circulating P. falciparum gametocytes in children. We also confirmed C3 and C4 hypocomplementemia in acute human malaria. The implication of our findings in relation to neat in vitro culture of P. falciparum gametocytes or total inhibition of gametocytogenesis in malaria control is still speculative.
Modification of Schaudinn fixative
Authors: Horen W P
Published: January 2020

In a search for a less toxic fixative, a Schaudinn solution substituting a divalent metallic cation for mercuric chloride proved to be satisfactory.
Application of a human osteogenic sarcoma cell culture for detection of human cytomegalovirus antibody by immunofluorescence tests
Authors: Furukawa T , Herold R , Zolnick P , Plotkin S A
Published: January 2020

A human osteogenic sarcoma cell culture is useful in the immunofluorescence serological test for detecting human cytomegalovirus antibody. These sarcoma cells are chronically infected with human cytomegalovirus and provide a constant number of immunofluorescence-positive cells.
Specificity of the passive hemagglutination test for antibody to rubella virus and the passive hemagglutination response after vaccination
Authors: Cremer N E , Hagens S J , Cossen C K
Published: January 2020

Nonspecific reactions by the passive hemagglutination test for rubella viral antibody occurred with 1.5% of sera tested. Rises in passive hemagglutination titers (greater than or equal to 4X) occurred with some serum samples taken 14 days after vaccination.
Exflagellation of malarial parasites in human peripheral blood
Authors: Gerber J E , Ukena T E , Cote L , Wyllie J M , Winn W C
Published: January 2020

Exflagellation of microgametocytes in malarial parasites is associated with the life cycle in the mosquito. However, it is not found with the usual developmental phases in humans. This report describes two case reports where exflagellation of microgametocytes was observed in vitro in patients documented to have Plasmodium vivax malaria.
Evaluation of the repliscan system for Enterobacteriaceae identification
Authors: Woolfrey B F , Quall C O , Fox J M
Published: January 2020

A total of 1,013 isolates of Enterobacteriaceae were identified in parallel by the Repliscan (Cathra International, Ontario, Canada) and API 20E (Analytab Products, Plainview, N.Y.) systems. There was a 62% agreement at the genus level between the two systems. Of the 38% discrepant results, Repliscan classified 22% as "biochemical pattern not on file," 8% as a multiple-genus group which included the API 20E identification, and 8% as a genus other than that designated by API 20E. Relative to the various genera, Repliscan agreed with API 20E as follows: Escherichia coli, 80%; Klebsiella spp., 76%; Citrobacter spp., 75%; Proteus spp., 69%; Providencia spp., 54%; Serratia spp., 49%; Enterobacter spp., 25%; Shigella spp., 4%; and Salmonella spp., 0%. Repliscan identified 35% of Enterobacter spp. isolates as Citrobacter spp., 91% of Shigella spp. isolates as a multiple-choice-genus group, and 67% of Salmonella spp. isolates as "biochemical pattern not on file." Repliscan agreed with API 20E at the species level as follows: E. coli, 80%; Klebsiella spp., 56%; Citrobacter spp., 66%; Proteus spp., 55%; Providencia spp., 46%; Serratia spp., 39%; Enterobacter spp., 18%; Shigella spp., 4%; and Salmonella spp., 0%. These findings indicate that the Repliscan system in its present stage of development does not reliably identify the Enterobacteriaceae.
Radioimmunoassays that use 125I-labeled protein A for determination of Histoplasma capsulatum-specific immunoglobulin G, A, and M class antibodies in histoplasmosis
Authors: Sprouse R F , Caldwell C W , Everett E D
Published: January 2020

A radioimmunoassay for determination of human immunoglobulin G, A, and M class antibodies to Histoplasma capsulatum is reported. Yeast-phase antigen from H. capsulatum was adsorbed onto polyvinyl chloride microtiter plates as the solid phase. Human antibodies were allowed to react with this antigen, followed by addition of rabbit anti-human alpha- or mu-heavy chain sera. 125I-labeled staphylococcal protein A was then added and allowed to bind the human and rabbit immunoglobulin G. With this technique, it is possible to evaluate individual human serum samples for antigen-specific classes of antibodies. This assay may be useful for monitoring the immune response in histoplasma infections.
Isolation of mycobacteria from undecontaminated specimens with selective 7H10 medium
Authors: Rothlauf M V , Brown G L , Blair E B
Published: January 2020

Media containing antimicrobial agents have been formulated for use as an adjunct to the standard media in an effort to reduce contamination and improve isolation of mycobacteria from clinical specimens. Selective 7H10 (S7H10) was developed for use in the isolation of mycobacteria from undecontaminated material. During a 33-month period, 10,782 clinical specimens were cultured in parallel on S7H10 without decontamination and on 7H11 after treatment with 2% sodium hydroxide-N-acetyl-L-cysteine. Results of this study show the overall contamination rate to be threefold lower on S7H10 than on 7H11 (304 versus 1,000). The number of specimens negative on NaOH-treated, 7H11-cultured specimens and contaminated on S7H10 was 282, whereas that negative on S7H10 but contaminated on NaOH-7H11 was 923. There were 6 positive cultures missed due to contamination on S7H10, compared with 61 on 7H11. Positive cultures on S7H10 outnumbered those on 7H11 by 106. This evaluation of S7H10 shows that it can be used with undecontaminated specimens in conjunction with standard methods and media for isolation of mycobacteria from clinical specimens.
Rapid, reproducible enzyme immunoassay for tobramycin
Authors: Francke E L , Srinivasan S , Labthavikul P , Neu H C
Published: January 2020

An enzyme immunoassay for tobramycin utilizing glucose 6-phosphate dehydrogenase was compared with the radioimmunoassay. The enzyme immunoassay for tobramycin was accurate, specific, and easily performed. It offers an alternative method for assaying aminoglycosides and could be used in institutions that use the enzyme immunoassay to assay other drugs.
Sensitive chemiluminescent enzyme-linked immunosorbent assay for quantification of human immunoglobulin G and detection of herpes simplex virus
Authors: Pronovost A D , Baumgarten A , Hsiung G D
Published: January 2020

A chemiluminescent enzyme-linked immunosorbent assay (CELISA) was developed for detecting human immunoglobulin G and herpes simplex viral antigen. A comparison of CELISA with a conventional absorptiometric detection system showed that CELISA was 100 times more sensitive than absorptiometry for the measurement of human immunglobulin G. Similarly, CELISA detected as few as 40 plaque-forming units of herpes simplex virus in contrast to 2,500 plaque-forming units detected by absorptiometry. Of 18 specimens which were positive for herpes simplex virus type 1 by isolation in tissue culture, 15 (83%) were detected by CELISA within a few hours; in certain cases, several days were necessary for detection of virus by isolation techniques.
Simple technique for separation of concentrated immunoglobulin M fractions by multi-sample gel chromatography and its application to rubella serodiagnosis
Authors: Inouye S , Kono R
Published: January 2020

A simple technique has been developed with which five serum specimens can be chromatographed at one time and concentrated immunoglobulin M fractions can be obtained without using fraction collectors and ultraviolet monitors. When applied to the detection of rubella immunoglobulin M antibody, this technique gave results comparable to the sucrose gradient centrifugation method.
Detection of respiratory syncytial, parainfluenza type 2, and adenovirus antigens by radioimmunoassay and enzyme immunoassay on nasopharyngeal specimens from children with acute respiratory disease
Authors: Sarkkinen H K , Halonen P E , Arstila P P , Salmi A A
Published: January 2020

Four-layer antispecies radioimmunoassay (RIA) and enzyme immunoassay (EIA) procedures were developed for the detection of respiratory syncytial virus (RSV), parainfluenza type 2 virus, and adenovirus antigens in nasopharyngeal specimens from children hospitalized for acute respiratory disease. Polystyrene beads (RIA) or flat-bottomed polystyrene microtiter plates (EIA) were used as the solid phases, guinea pig anti-virus immunoglobulins were used as the captive antibodies, rabbit anti-virus immunoglobulins were used as the secondary antibodies, and 125I-labeled sheep anti-rabbit (RIA) or horseradish peroxidase-labeled swine anti-rabbit (EIA) immunoglobulins were used as the indicator antibodies. A comparison of the EIAs and RIAs with routinely used immunofluorescence (IF) techniques was made with 164 nasopharyngeal specimens collected from children with acute respiratory disease. Only 3 of 66 RSV IF-positive specimens were negative in RSV RIA, and of 83 RSV, parainfluenza type 2 virus, and adenovirus IF-negative specimens, 1 was positive in RSV RIA. Of 4 parainfluenza type 2 virus IF-positive and 11 adenovirus IF-positive specimens, each was positive in corresponding RIAs, and all 83 IF-negative specimens were negative in parainfluenza type 2 virus and adenovirus RIAs. The results of the RSV, parainfluenza type 2, and adenovirus EIAs confirmed the results of corresponding RIAs in each selected case tested. The RIAs and EIAs were found to be as specific and sensitive as IF techniques, and more practical in the rapid detection of respiratory viruses in nasopharyngeal secretions.
Campylobacter fetus subsp. jejuni in a turkey processing plant
Authors: Luechtefeld N W , Wang W L
Published: January 2020

Cecal cultures taken over a 1-year period from 600 turkeys at a poultry processing plant were all positive for Campylobacter fetus subsp. jejuni. Swabs of the cloaca and fresh feces were likewise all positive. Of 33 freshly dressed turkey carcases, 94% were positive before chilling in tanks of chlorinated ice and water; 34% of 83 carcasses were still positive after overnight soaking in the tanks. Increasing the chlorine content from 50 to 340 ppm (50 to 340 micrograms/ml) did not cause a decrease in the number of positive carcasses. C. fetus subsp. jejuni was isolated from wastewater gutters as well as from chutes and conveyor belts in the packaging room. Water samples from the five water treatment lagoons for the plant were all positive for C. fetus subsp. jejuni while the plant was in operation, but 4 days after the plant closed for the winter, all water samples were negative.
Quantitative fluorescent immunoassay for measurement of antibody to Dirofilaria immitis in dogs
Authors: Gittelman H J , Grieve R B , Hitchings M M , Jacobson R H , Cypess R H
Published: January 2020

An automated fluorescent immunoassay technique (FIAX; International Diagnostic Technology, Santa Clara, Calif.) has been developed for the quantitation of circulating antibodies in dogs infected with Dirofilaria immitis. Two groups of sera, group I consisting of 77 samples and group II consisting of 126 samples, were obtained from experimentally infected microfilaremic dogs, known negative controls, and clinically diagnosed cases of occult dirofilariasis. Antibody against a partially purified trichloroacetic acid-soluble extract of a soluble somatic extract of D. immitis was measured by FIAX and by an enzyme-linked immunosorbent assay (ELISA). A standard curve was drawn from four samples with known FIAX titers and fluorescent signal unit values. The standard curve was used to determine titers of unknown samples. The correlation coefficients determined in the analysis of log10 ELISA and log10 FIAX values were r = 0.9057 and r = 0.8976 in groups I and II, respectively. Eighty-three percent of the titer values calculated by FIAX in group I were within one dilution, and 95% were within two dilutions, of those titers obtained by ELISA. In group II, 79 and 96% of the values obtained by FIAX were within one and two dilutions, respectively, of those obtained by ELISA. FIAX proved to be a reproducible and convenient assay for the measurement of serum antibody in dogs experimentally infected with Dirofilaria.
Assessment of laboratory improvement by the Center for Disease Control Diagnostic Immunology Proficiency Testing Program
Authors: Taylor R N , Fulford K M
Published: January 2020

The data accumulated from 1969 to 1979 in the Diagnostic Immunology portion of the Center for Disease Control Proficiency Testing Program were evaluated for evidence of change in performance among the participating laboratories. Evidence of improved performance was found for the rubella, rheumatoid factor, tularemia, quantitative immunoglobulin (immunoglobulin G, A, and M), and hepatitis B tests. No evidence of change was detected for the streptococcal enzyme, C-reactive protein, infectious mononucleosis, antinuclear antibodies, Salmonella and Brucella agglutinins, and syphilis tests. Data obtained from other tests were inadequate to determine trends. In most tests, deficiencies were identified which could be corrected and thereby could improve performance. It is pointed out that proficiency testing not only improves laboratory performance, but also can be used to evaluate performance levels, identify method, standard, or performance deficiencies, educate, estimate impact of possible changes, serve as external quality control, and document changes.
Relationships between serological groups and deoxyribonucleic acid homology groups in Bacteroides fragilis and related species
Authors: Babb J L , Cummings C S
Published: January 2020

The serological properties of antigens extracted from strains of Bacteroides fragilis and related species belonging to several different deoxyribonucleic acid homology groups were investigated. Antisera prepared against Formalin-treated whole cell suspensions of representative strains were tested against cell suspensions, cell wall preparations, and extracts of homologous and heterologous strains by using agglutination, immunodiffusion, and hemagglutination techniques. Serological results indicated that the species were antigenically distinct, although minor cross-reactions were observed. Homology groups, including the two B. fragilis subgroups, were relatively homogeneous, although the presence of serotypes within each homology group was suggested. Immunodiffusion tests demonstrated, however, that each possessed a mosaic antigen composition; at least 6 antigenic determinants could be demonstrated in B. fragilis 2553, and up to 10 were found in B. fragilis 2393. Hemagglutination tests using antigen extracts also indicate a mosaic of antigens in each strain.
New, special stain for histopathological diagnosis of cryptococcosis
Authors: Kwon-Chung K J , Hill W B , Bennett J E
Published: January 2020

The Masson-Fontana silver stain for melanin was employed for the differentiation of pathogenic fungal species in human or mouse tissues. The fungi studied were Candida albicans, Candida tropicalis, Candida glabrata (Torulopsis glabrata), Cryptococcus neoformans, Cryptococcus bacillisporus, Coccidioides immitis, Blastomyces dermatitidis, Histoplasma capsulatum, Paracoccidioides brasiliensis, Sporothrix schenckii, Rhizopus rhizopodiformis, and Aspergillus fumigatus. The tissue sections stained with Masson-Fontana silver stain showed a dark brown to black color in the wall of cryptococci, whereas the walls of remaining fungal species were hyaline, except for those of S. schenckii. The yeastlike cells of S. schenckii showed faint brown pigment on the wall. Cultures of these fungi showed staining characteristics identical to those of the in vivo results. Cultures of four nonpathogenic Cryptococcus species, Cryptococcus uniguttulatus, Cryptococcus laurentii, Cryptococcus terreus, and Cryptococcus luteolus, were also tested for staining by the Masson-Fontana procedure. Of these, only C. laurentii stained positively, and the pigment on the cell wall was as intense as that of the cells of C. neoformans. These results indicate that the Masson-Fontana silver stain can be used as a specific stain in the histological diagnosis of cryptococcosis.
Rapid method that aids in distinguishing Gram-positive from Gram-negative anaerobic bacteria
Authors: Halebian S , Harris B , Finegold S M , Rolfe R D
Published: January 2020

Several species of anaerobic bacteria display variable Gram stain reactions which often make identification difficult. A simple, rapid method utilizing a 3% solution of potassium hydroxide to distinguish between gram-positive and gram-negative bacterial was tested on 213 strains of anaerobic bacteria representing 19 genera. The Gram stain reaction and KOH test results were compared with the antibiotic disk susceptibilities (vancomycin and colistin) the preliminary grouping of anaerobic bacteria. All three procedures were in agreement for the majority of strains examined. Some strains of clostridia, eubacteria, and bifidobacteria stained gram negative or gram variable; the KOH and antibiotic disk susceptibility tests correctly classified these strains as gram-positive. The KOH test incorrectly grouped some strains of Bacteroides sp., Fusobacterium sp., Leptotrichia buccalis, and Veillonella parvula, but all Gram stain results for these strains were consistent for gram-negative bacteria. The KOH test is a useful supplement to the Gram stain and antibiotic disk susceptibility testing for the initial classification of anaerobic bacteria.
Enzyme-linked immunosorbent assay compared with immunoprecipitation for serotyping Neisseria meningitidis and its use in demonstrating serotype polymorphism
Authors: Mackie E B , White L A , Brown K N , Bryan L E
Published: January 2020

Rabbit antisera generated against 11 prototype strains of group B Neisseria meningitidis were tritiated by using the enzyme-linked immunosorbent assay and the Ouchterlony immunoprecipitation technique. The relative insensitivity of the immunoprecipitation technique in detecting antibody compared with the enzyme-linked immunosorbent assay was demonstrated. Cross-reactions within the group and among the 11 serotypes were characterized with respect to established serological techniques. Serotype polymorphism among the strains of N. meningitidis was demonstrated with the enzyme-linked immunosorbent assay.
Inhibition of Neisseria gonorrhoeae by sodium polyanetholesulfonate
Authors: Staneck J L , Vincent S
Published: January 2020

Sodium polyanetholesulfonate (SPS), in concentrations commonly used in blood culture media, inhibited the growth of a significant number of isolates of Neisseria gonorrhoeae in an agar dilution system. This SPS toxicity, shown to be bactericidal when examined in broth culture, could be reversed by hemoglobin and gelatin. Gelatin in 1% concentration allowed optimal growth of SPS-sensitive isolates in the presence of 0.025% SPS. Of 50 clinical isolates of N. gonorrheae tested under simulated blood cultures conditions with SPS, 16 isolates failed to grow on subculture at days 1, 3, and 10 after inoculation. Recovery was delayed with eight isolates as compared to controls. Early subcultures at 4, 8, and 12 h failed to recover SPS-sensitive isolates, whereas 1% gelatin, added even as late as 8 h after inoculation, reversed the SPS toxicity. The data reported suggest that SPS at concentrations routinely used in blood cultures can delay or prevent isolation of N. gonorrhoeae, but 1% gelatin can eliminate this adverse effect.
Preliminary identification of mycobacteria isolated from clinical specimens
Authors: Murray P R , Krogstad D J
Published: January 2020

From March 1979 to June 1980, we preliminary identified mycobacteria at the time of their initial isolation by colonial morphology, pigmentation, and growth rate. The definitive identifications were predicted accurately for 92% of the mycobacteria isolated from 108 patients. For laboratories that isolate relatively few different species of mycobacteria, the advantages of this approach are its simplicity and the speed with which presumptive identifications can be made available for clinical use.
Optimal fluorescein-to-protein ratios of bacterial direct fluorescent-antibody reagents
Authors: Hébert G A , Pittman B , McKinney R M
Published: January 2020

A number of bacterial systems were studied with specific direct fluorescent-antibody reagents prepared from rabbit antiserum fractions and having a wide range of fluorescein-to-protein ratios. These systems included Bacteroides, Bordetella, Clostridium, Escherichia, Legionella, Listeria, Salmonella, Shigella, and Streptococcus. For all systems studied, a fluorescein-to-protein ratio of 30 was optimal for conjugates prepared from ammonium sulfate fractions (greater than 75% gamma globulin) and pure immunoglobulin G desorbed from the Sepharose-bound protein A of Staphylococcus aureus. A pepsin digestion procedure is described that yielded the F(ab')2 piece of pure immunoglobulin G; this was labeled and studied at two fluorescein-to-protein ratios.
Selective medium for isolation of Clostridium botulinum from human feces
Authors: Dezfulian M , McCroskey L M , Hatheway C L , Dowell V R
Published: January 2020

A selective medium, Clostridium botulinum isolation (CBI) agar, was developed for the isolation of C. botulinum from human feces. This medium contains cycloserine (250 microgram/ml), sulfamethoxazole (76 microgram/ml), and trimethoprim (4 microgram/ml) as selective inhibitory agents. Qualitative tests indicated complete recovery of C. botulinum types A, B, F, and G on CBI medium. It was more difficult to recognize type G colonies on the medium because of their lack of lipase activity. Except for a few species of Clostridium, the growth of other obligate anaerobes and of the facultative anaerobes tested on CBI medium was suppressed. Quantitative studies of C. botulinum on the selective medium yielded counts comparable to those obtained on egg yolk agar control plates. Isolation of C. botulinum types A, B, and F from seeded fecal specimens was easily achieved with CBI medium. The use of CBI agar should aid the rapid isolation of C. botulinum from fecal specimens associated with foodborne and infant botulism.
Comparison of an HEp-2 Tissue Culture Test with the Serény Test for Detection of Enteroinvasiveness in
Shigella
spp. and
Escherichia coli
Authors: Day N. P. , Scotland S. M. , Rowe B.
Published: January 2020

A good correlation was observed between the Serény test and an HEp-2 tissue culture test for the detection of enteroinvasiveness in
Shigella
spp. and
Escherichia coli
.
Effect of antibiotics on the dynamics of color change in Ureaplasma urealyticum cultures
Authors: Bloomster T G , Lynn R J
Published: January 2020

Color change of pH indicators in broth medium is commonly used to quantify growth of ureaplasmas. These organisms differ from other members of the Mollicutes by their ability to hydrolyze urea to CO2 and NH3. This study describes a method which continuously monitors color change in ureaplasmal broth cultures. Using this technique we found: (i) there was a pH-dependent absorbance at 554 nm in ureaplasmal broth medium containing phenol red, (ii) a sigmoidal-shaped color changing curve (absorbance at 554 nm versus time) was produced by metabolizing organisms whereas a linear curve was generated by antibiotic-inhibited ureaplasmas, and (iii) the minimum cell density which elicited a growth-inhibited color change was 1.25 x 10(4) colony-forming units per ml. Other have shown that apparently dead ureaplasmas can cause a color change in broth media. This color change is probably due to the presence of an active urease. This study graphically and quantitatively assesses growth-inhibited color change.
Fatty Acid Composition of Rickettsiae
Authors: Tzianabos Theodore , Moss C. Wayne , McDade Joseph E.
Published: January 2020

The fatty acid compositions of selected strains of rickettsiae were studied by gas-liquid chromatography. The profiles of all the rickettsiae except
Coxiella burnetii
were qualitatively similar. The fatty acid composition of
C. burnetii
was similar to that of certain
Legionella
species.
Application of immunoperoxidase staining to more rapid detection and identification of rubella virus isolates
Authors: Schmidt N J , Ho H H , Chin J
Published: January 2020

Efforts were made to shorten the time required for detection of rubella virus in clinical materials through the use of immunoperoxidase (IP) staining. Comparative studies were performed in which specimens were inoculated in parallel into BHK-21 hamster kidney cells, which were examined by IP staining at 5 days, and into BK-13 and BS-C-1 cells, which were examined in two ways, viz., by subpassage at 7 days into BHK-21 cells and IP staining 3 days later and by subpassage at 7 days into BS-C-1 cells followed by interference testing and immunofluorescence (IF) staining on positive materials (standard method). Direct inoculation into BHK-21 cells with IP staining at 5 days permitted detection and identification of 59% of the 63 positive specimens. Toxicity of some specimens preserved with sorbitol and of certain tissue specimens reduced the number of satisfactory examinations which could be performed in this system. Virus detection and identification by IP staining on subpassaged RK-13 and BS-C-1 materials, requiring a total of 18 days, was comparable to the longer interference-IF method, requiring 17 days. Results obtained by IP staining and interference-IF showed 98% correlation on RK-13 materials and 97% correlation on BS-C-1 materials. IP staining on inoculated BHK-21 cells can be a useful method for rapid identification of a relatively high proportion of rubella-positive specimens, particularly if sorbitol-preserved specimens are avoided, and IP staining on subpassaged RK-13 and BS-C-1 materials is a highly satisfactory alternative to the longer interference-IF method.
Capnocytophaga ochracea
Septicemia
Authors: Gilligan Peter H. , McCarthy L. R. , Bissett Brenda K.
Published: January 2020

A case report describing
Capnocytophaga ochracea (Bacteroides ochraceus)
septicemia in a 21-year-old male patient receiving chemotherapy for acute lymphocytic leukemia is presented. The unusual features of this organism are discussed together with a review of the literature.
Evaluation and optimization of urine screening by Autobac
Authors: Kelly M T , Balfour L C
Published: January 2020

The purpose of this investigation was to evaluate the effectiveness of the Autobac (Pfizer Inc., New York, N.Y.) urine screen for detection of bacteriuria in 3,026 urine specimens and to establish the optimum procedure for the Autobac system. Overall, 97% of urine specimens having greater than 10(5) colony-forming units (CFU) per ml were detected within 5 h by the Autobac system. The system detected 66, 90, and 94% of such specimens after 2, 3, and 4 h of incubation, respectively. Of specimens having 10(4) to 10(5) CFU/ml, the Autobac system detected 10, 45, 53, and 95% after 2, 3, 4, and 5 h of incubation, respectively. The rate of false-positive results increased from 0% after 2 h to 2% after 3 h to 6% after 4 h and 25% after 5 h of incubation. The specificity of the urine screening results also varied with the incubation time. Percentages of specimens having greater than 10(5) CFU/ml that gave positive urine screening results at various times were as follows: 96% at 2 h, 74% at 3 h, 29% at 4 h, and 9% at 5 h. These findings suggest that a 3- or 4-h urine screening procedure will effectively detect bacteriuria of greater than 10(5) CFU/ml, with few false-positive results. However, a 5-h procedure, which gives more false-positive results, may be needed for detection of lower levels of bacteriuria.
Metal requirements of Legionella pneumophila
Authors: Reeves M W , Pine L , Hutner S H , George J R , Harrell W K
Published: January 2020

Serial passage of six strains of Legionella pneumophila and one strain of Pseudomonas aeruginosa in a liquid chemically defined medium deficient in trace metals resulted in the death of five L. pneumophila strains and very limited growth in the remaining strain and the P. aeruginosa strain. Addition of either iron or magnesium restored growth to almost normal levels in all of the strains when early-passage inocula were used. A low concentration of magnesium stimulated growth with cobalt, copper, iron, manganese, molybdenum, vanadium, or zinc. When a complete defined medium containing trace metals was used, growth was inhibited by adding the chelators ethylenediaminetetraacetic acid, citrate, or 2,2'-bipyridyl. Chelator inhibition was partly or fully relieved with either calcium, cobalt, copper, iron, magnesium, molybdenum, nickel, vanadium, or zinc. P. aeruginosa differed from L. pneumophila in that it required higher concentrations of each chelator to inhibit growth and that its growth was stimulated by only four metals: calcium, iron, magnesium, and zinc. A trace-metal supplement for L. pneumophila was designed which included all metals stimulating growth in these experiments and which proved to be sufficient for optimal growth of all the strains.
Comparison of clinical results for the use of ethyl acetate and diethyl ether in the formalin-ether sedimentation technique performed on polyvinyl alcohol-preserved specimens
Authors: Garcia L S , Shimizu R
Published: January 2020

One hundred fecal specimens preserved in polyvinyl alcohol fixative were examined by the Formalin-ether sedimentation technique with ethyl acetate substituted for diethyl ether. Technical performance of the procedures, appearance and amount of sediment obtained, and organism morphology were comparable. Also, ethyl acetate is less flammable and, therefore, less dangerous to use than diethyl ether. Results of parasite recovery when diethyl ether or ethyl acetate was used revealed few clinical relevant differences, most of which could also have been attributed to other variables inherent in this type of diagnostic testing.
Legionella micdadei (Pittsburgh pneumonia agent): direct fluoresent-antibody examination of infected human lung tissue and characterization of clinical isolates
Authors: Cordes L G , Myerowitz R L , Pasculle A W , Corcoran L , Thompson T A , Gorman G W , Patton C M
Published: January 2020

Legionella micdadei (Pittsburgh pneumonia agent) was identified by direct fluorescent-antibody (DFA) examination of lung tissue in six of seven persons diagnosed previously as having L. micdadei pneumonia only by histopathology and in four persons who also had positive cultures of the organism. No cross-reactions occurred with monospecific DFA conjugates prepared against Legionella pneumophila serogroups 1 to 6, Legionella bozemanii, Legionella dumoffii, and Legionella gormanii. One person had L. pneumophila serogroup 6 identified by DFA examination of lung tissue and subsequent culture of stored pulmonary secretions. Characterization of the four strains of L. micdadei revealed specific DFA reactions, bacteriological behavior, and cellular fatty acid composition that allow identification of the organism. DFA testing appears to be a sensitive method for identifying L. micdadei prescent in human lung tissue or cultured on artificial media.
Evaluation of five gentamicin assay procedures for clinical microbiology laboratories
Authors: Selepak S T , Witebsky F G , Robertson E A , MacLowry J D
Published: January 2020

Five gentamicin assay procedures (a bioassay, an enzyme immunoassay, a latex agglutination inhibition test, a fluorescence immunoassay, and a radioimmunoassay) were evaluated to determine which was optimal for our laboratory. The evaluation was based on recovery and precision studies and results of analyses of patient samples, as well as technical assay performance factors. The latex agglutination inhibition test appears useful for laboratories performing only occasional assays for gentamicin; however, the fact that some rheumatoid factor-positive sera, as well as some other sera for unknown reasons, may give falsely low values is a potential drawback to this procedure. Because of its accuracy, precision, rapid turn-around time, and relative simplicity of performance, we selected the enzyme immunoassay procedure for routine use for gentamicin assays in our laboratory.
Emergence of gentamicin- and methicillin-resistant Staphylococcus aureus strains in New York City hospitals
Authors: Schaefler S , Jones D , Perry W , Ruvinskaya L , Baradet T , Mayr E , Wilson M E
Published: January 2020

Gentamicin- and methicillin-resistant strains of Staphylococcus aureus have been isolated from Spring 1979 to the present from many hospitals in New York City. A large proportion of the strains were resistant to the majority of antistaphylococcal antibiotics. The ratio of multiply resistant strains was highest among tetracycline-resistant strains. There were significant differences in phage susceptibility patterns and the resistance spectrum of strains isolated at different hospitals, whereas strains isolated at the same hospital often showed a marked degree of similarity. This suggests multiple origins of gentamicin- and methicillin-resistant strains isolated in New York City.
Alternative ways of estimating serological titer reproducibility
Authors: Wood R J
Published: January 2020

A quantitative measure of the reproducibility of serum antibody titers has recently been proposed (R. J. Wood and T. M. Durham, J. Clin. Microbiol. 11: 541-545, 1980). The measure advocated is "the probability that the maximum ratio of two distinct (integer) titers (obtained in the blind) on the same specimen will not exceed 2." This measure of the reproducibility of serological titers is considered to be a fixed probability for any given specimen and set of test conditions. Although it is a fixed constant during the time period of a study, there are alternative methods one might use to compute an estimate of it, using laboratory data. Four such methods of estimating test reproducibility are discussed and evaluated. The estimates obtained from the two principle methods are evaluated quantitatively by means of Monte Carlo computer simulation. The simulation results show that, from a given sample of replicate integer titers, these two principal methods yield estimates that are highly correlated. In addition, with moderate numbers of replicates (sample size) these methods provide estimates that are on the average properly directed at the true reproducibility values (that is, are essentially, unbiased), particularly when the true reproducibility of the test is at least 0.9. The reliability, or stability, of the alternative estimates is studied for selected sample size.
Thermophilic Sporeforming Bacilli That Mimic Fastidious Growth Characteristics and Colonial Morphology of Legionellae
Authors: Thacker LeRoy , McKinney Roger M. , Moss C. Wayne , Sommers Herbert M. , Spivack Martin L. , O'Brien Thomas F.
Published: January 2020

Gram-negative bacilli resembling legionellae were isolated from contaminated culture media. These bacilli are distinguishable from legionellae by their thermophilic characteristic.
Rapid detection and identification of Bacteroides fragilis and Bacteroides melaninogenicus by immunofluorescence
Authors: Weissfeld A S , Sonnenwirth A C
Published: January 2020

Bacteroides fragilis group and Bacteroides melaninogenicus group fluorescent-antibody kits were evaluated with 188 clinical specimens and 116 fresh aerobic and anaerobic bacterial isolates. Fluorescent-antibody and culture results corresponded in 88% of clinical specimens of the B. fragilis group and 94% of clinical specimens of the B. melaninogenicus group. There was greater than or equal to 90% correlation for both kits with colony smears. Antigen sharing by Bacteroides bivius, Bacteroides disiens, and B. melaninogenicus was demonstrated.
Anaerobiospirillum succiniciproducens
Septicemia
Authors: Rifkin Gary D. , Opdyke James E.
Published: January 2020

Septicemia due to a recently described gram-negative, spiral-shaped anaerobe,
Anaerobiospirillum succiniciproducens
, is presented. The biochemical characteristics and antimicrobial sensitivity pattern of this organism are reported.