bluuebunny/crossref_metadata_2025 huggingface dataset:
Bactericidal screening test for late complement component deficiencies or defects
Authors: Eng R H
Published: January 2020

Congenital complement deficiency has been described in disseminated Neisseria infections. Its occurrences in humans with other kinds of infections have not been described. In the past, CH50 determinations have been used to detect these deficiencies, but this procedure is time consuming and cumbersome. A method of determining the presence of late component deficiencies or defects is described which is easy and inexpensive to perform. An agar pour plate with a serum-sensitive Escherichia coli strain is made, and 2.5-mm wells are put in the agar. Unknown fresh sera are used to fill the wells. An absence of a zone of bacterial growth inhibition around the well after incubation at 37 degrees C overnight indicates a late component defect or deficiency in the test serum. By applying this assay to 35 selected patients, four deficient patients were identified. One had a congenital C5 deficiency and three had C6 deficidencies. It is suggested that the assay be used as a screening test to study the relationship between congenital complement deficiencies and various kinds of infections, especially those caused by organisms which are partially serum sensitive.
Autobac I procedure to assess susceptibility to Cefaclor
Authors: Gröschel D , Mills K , Hopfer R L
Published: January 2020

Agar dilution and Autobac I tests were performed to compare the susceptibility of 1,000 bacterial isolates to cefaclor and cephalothin. The standard Autobac methodology will correctly predict resistance to cefaclor. The test methodology seems to influence in vitro results, since more strains of gram-negative bacteria were susceptible to cefaclor by the Autobac I method than by the agar dilution test.
Non-Type b
Haemophilus influenzae
Infections in Adults with Reference to Biotype
Authors: Eng Robert H. K. , Corrado Michael L. , Cleri Dennis , Sierra Marcelino F.
Published: January 2020

We report three cases of serious non-group b
Haemophilus influenzae
infections. The significance of these isolates with respect to both biotypes and serotypes is discussed.
Standardized quantitative enzyme-linked immunoassay for antibodies to Toxoplasma gondii
Authors: Lin T M , Halbert S P , O'Connor G R
Published: January 2020

A quantitative and standardized enzyme-linked immunosorbent assay is described which uses lyophilized antigen-coated disks for the detection of human antibodies to Toxoplasma gondii. It does not require serial dilution of the test specimen, and the objective absorbance readings are converted into international units per milliliter traceable to the World Health Organization's reference standard preparation of toxoplasma antibodies. It was shown to be highly specific, reproducible, and sensitive. The reagents were stable, without biohazard, and ready for use. Studies of various parameters in the assay indicated that the test conditions were relatively flexible. The enzyme-linked immunosorbent assay results correlated satisfactorily with the methylene blue dye test, the indirect immunofluorescence test, and the passive hemagglutination test.
Cryopreservation of virus-infected cells for use in the fluorescent antibody to membrane antigen test
Authors: Fishaut M , Murphy N , Yanagihara R , McIntosh K
Published: January 2020

Tissue culture cells infected with varicella-zoster, respiratory syncytial, para-influenza types 1, 2, and 3, and influenza A/Texas/1/77 and A/USSR/90/77 viruses were exposed to ultraviolet light and frozen in the presence of a final concentration of 20% glycerol. These cells were quick thawed at 37 degrees C and compared with freshly prepared, living infected tissue culture cells in assays of fluorescence antibodies to membrane antigens of the infecting agents in serum, nasal wash secretions, colostrum, and breast milk. Frozen cells performed as efficiently as fresh cells as targets and retained their activity for long periods of time. Cryopreservation combined with photoinactivation of infected target cells allows this useful antibody test to be performed in routine serology laboratories.
2-mercaptoethanol Brucella agglutination test: usefulness for predicting recovery from brucellosis
Authors: Buchanan T M , Faber L C
Published: January 2020

Ninety-two patients with brucellosis were studied for 18 months, and 15 to 29 sera from each patient were tested by the standard tube brucella agglutination test and by the 2-mercaptoethanol (2ME) brucella agglutination test. The standard tube test remained positive (greaterr than or equal to 160) for 1.5 years in 44 of the 92 patients (48%), despite adequate antibiotic treatment. The 2ME titers remained positive (greater than or equal to 160) in only 8 of 92 patients (9%) after 1 year, and in only 4 of 92 patients (4%) after 1.5 years. Positive 2ME titers 1 year after initiation of treatment were present in 3 of 10 patients (30%) with drug allergies that interfered with antibiotic treatment, in contrast to only 5 of 82 patients (6%) without any allergies (P = 0.039). None of 84 patients with negative 2ME titers after 12 months of treatment had significant signs or symptoms of brucellosis, and none developed chronic brucellosis. In contrast, four of eight patients with positive 2ME titers after 12 months of treatment still had signs and symptoms of brucellosis and required further treatment. The 2ME test is superior to the standard tube test in determining the adequacy of antibiotic therapy, and a negative 2ME test is strong evidence against a diagnosis of chronic brucellosis.
Extremely high titers of serum antibodies against the streptococcal exoenzyme deoxyribonuclease B
Authors: Hederstedt B , Holm S E , Norberg R
Published: January 2020

In sera from 4 of 25,000 individuals tested for antibodies against streptococci, extremely high antideoxyribonuclease B titers ( > 10(6) U/ml) were found. Two of the cases were diagnosed as monoclonal gammopathies. The M-components were shown to possess the anti-deoxyribonuclease B activity. The other two cases were diagnosed as relapsing erysipelas. The high serum titers of deoxyribonuclease B antibodies were accompanied by a very inflammatory reactivity in the patients' sera and by an oligopolyclonal pattern of immunoglobulin G. In routine diagnoses of streptococcal infections with the anti-deoxyribonuclease B test, patients with extremely high serum titers should be examined for the possible occurrence of gammopathies.
Identification of nocardiae and streptomycetes of medical importance
Authors: Mishra S K , Gordon R E , Barnett D A
Published: January 2020

During a taxonomic investigation of Nocardia spp. and Streptomyces spp., we received 658 isolates from laboratories of both human and veterinary medicine. Our procedure leading to the identification of 92% of these isolates, the species that they represented, and a characteristic pattern of properties of the strains of these species are presented. A key devised for the tentative identification of species of nocardiae and streptomycetes that are believed to be of medical importance is included to assist clinical microbiologists in identifying their strains.
Propagating
Bacillus subtilis
Spores in a Liquid Medium for the Guthrie Bioassay
Authors: Sinor Martha
Published: January 2020

Eagle growth medium was used successfully for the production of spores of
Bacillus subtilis
for the Guthrie bioassay screening tests for genetic metabolic disorders.
Comparison of the Hemagglutination Inhibition Test and an Indirect Fluorescent-Antibody Test for Detection of Antibody to Rubella Virus in Human Sera
Authors: Cremer Natalie E. , Hagens Shirley J. , Cossen Cynthia
Published: January 2020

Correlation between FIAX and hemagglutination inhibition methods for presence or absence of rubella viral antibody was good at high hemagglutination inhibition titers, but only fair at low or negative titers.
Acid-fast actinomyces in a child with pulmonary actinomycosis
Authors: Lowe R N , Azimi P H , McQuitty J
Published: January 2020

Open-lung biopsy in a child with chronic pneumonia revealed branched gram-positive acid-fast organisms, later identified as Actinomyces israelii. Like Nocardia asteroides, A israelii can be acid fast by the commonly used Putt stain. The pneumonia was cured with 12 weeks of penicillin treatment.
SJ-GC, a modified complete medium for growth of Neisseria gonorrhoeae
Authors: Shockley R K , Coffee E E , Johnston K H
Published: January 2020

A broth medium that supports growth of Neisseria gonorrhoeae to high densities with minimal lysis is described. With most gonococcal strains, inocula of 2 x 10(6) colony-forming units per ml yielded greater than 109 colony-forming units per ml after 8 h of incubation. Scale-up cultures produced 5 to 12 g (wet weight) of cells per liter.
Solid-phase enzyme immunoassay for determination of antibodies to cytomegalovirus
Authors: Krishna R V , Meurman O H , Ziegler T , Krech U H
Published: January 2020

A solid-phase enzyme immunoassay for the determination of immunoglobulin H (IgG) and IgM antibodies to cytomegalovirus is described. The enzyme immunoassay gave reliable and consistent results which were in concordance with those obtained by the complement fixation test and the indirect immunofluorescence test. Antibodies to herpes simplex and varicella-zoster viruses did not interfere in the enzyme immunoassay for cytomegalovirus IgM antibodies. In a few patients with IgM antibodies to Epstein-Barr virus, cytomegalovirus IgM antibodies were also detected. False-positive cytomegalovirus IgM antibody results were observed in sera containing both the rheumatoid factor and cytomegalovirus IgG antibodies. This rheumatoid factor interference was overcome by the absorption of sera with polymerized human gamma globulin. The absorption did not affect true cytomegalovirus IgM antibody titers. Also described is a simple enzyme immunoassay that makes possible a more sensitive detection of the rheumatoid factor than the latex agglutination test.
Monoclonal antibodies specific for dengue virus type 3
Authors: Dittmar D , Haines H G , Castro A
Published: January 2020

Mouse lymphocyte hybridomas were prepared by polyethylene glycol-mediated fusion of cells from a mouse plasmacytoma line with lymphocytes from a mouse hyperimmunized with dengue virus type 3 (dengue-3). Media from 50 hybrid colonies were screened; 46 of them showed antibody activity against dengue-3-infected cells as determined by an indirect immunofluorescent antibody technique. Dengue monoclonal antibody obtained after cloning one of these colonies demonstrated activity in hemagglutination inhibition and indirect immunofluorescent antibody assays with dengue-3 antigen, but not type 1, 2, and 4 antigens. In addition, this antibody activity could be removed from culture media only by absorption with dengue-3 antigen.
Activation of streptolysin S-related cellular potential hemolysin by grinding with glass beads
Authors: Calandra G B , Whitt R S
Published: January 2020

Cellular potential hemolysin, the precursor to extracellular streptolysin S, was activated by grinding with glass beads on a Vortex mixer. Hemolysin activity was markedly enhanced by the addition of ribonucleic acid-core during the grinding. Determinants for optimum results with the beads included small bead size, prewashing of beads with acetic acid, and appropriate bead volume during grinding. The increased sensitivity of this technique over those previously used revealed cellular potential hemolysin in cells grown in the presence of glucose, which inhibits streptolysin S production. The basis for the increased sensitivity of this procedure may be due to the binding of cellular potential hemolysin or ribonucleic acid to the beads.
Detection of Rocky Mountain spotted fever antibodies by a latex agglutination test
Authors: Hechemy K E , Anacker R L , Philip R N , Kleeman K T , MacCormack J N , Sasowski S J , Michaelson E E
Published: January 2020

A latex test for immunodiagnosis of Rocky Mountain spotted fever, using erythrocyte-sensitizing substance from Rickettsia rickettsii adsorbed to latex particles, has been developed. The test was evaluated with a total of 123 single and 118 paired human sera submitted for Rocky Mount spotted fever testing. This test is simple, sensitive, and specific. Its efficiency, relative to the reference microimmunofluorescence test, was 95.1% for single sera and approached 100% for paired sera.
Enrichment culture coagglutination test for rapid, low-cost diagnosis of salmonellosis
Authors: Sanborn W R , Lesmana M , Edwards E A
Published: January 2020

Specific diagnosis of salmonellosis by conventional culture and identification methods usually requires 2 to 4 days. Since Salmonella may be disseminated from infected individuals during this period, this amount of time required for diagnosis may be too slow to aid in epidemic control. To obtain earlier diagnoses of salmonellosis, a coagglutination test was used for rapid, simplified detection of Salmonella oranienburg antigens in enrichment broth cultures of fecal specimens from infants involved in a nursery outbreak. Two selective enrichment broths were used, selenite cystine and dulcitol selenite. These were compared in parallel for efficiency by subculture on deoxycholate lactose sucrose, MacConkey, xylose lysine deoxycholate, and tryptic soy lactose teepol agars. These overnight enrichment broth cultures of stool specimens were also examined by a coagglutination slide test with stabilized protein A-containing staphylococci sensitized with antisera for Salmonella antigens C1, E, and Vi. Of 113 diarrhea stool specimens tested, 86 were positive by conventional culture, 82 were positive by dulcitol selenite-coagglutination, and 55 were positive by selenite cystine-coagglutination. All these tests were negative on 50 stool specimens from infants in a noninfected nursery. Salmonellae were specifically detected in stool cultures within 20 h by the coagglutination technique. This early detection of Salmonella antigens provided a useful adjunct to culture for rapid diagnosis of salmonellosis.
Classification and characteristics of coagulase-negative, methicillin-resistant staphylococci
Authors: Wilkinson B J , Maxwell S , Schaus S M
Published: January 2020

Sixty-five clinical isolates of coagulase-negative, methicillin-resistant staphylococci have been classified as Staphylococcus epidermidis (63.0%), "phosphatase-negative S. epidermidis" (12.3%), coagulase-negative Staphylococcus aureus (6.2%), Staphylococcus hemolyticus (6.2%), Staphylococcus hominis (3.1%), and Staphylococcus warneri (1.5%). Five of the organisms (7.7%) could not be classified with certainty as currently recognized species. Novobiocin resistance was encountered in eight of the strains, but these were not classified as the accepted novobiocin-resistant staphylococcal species. Some differences in antibiotic resistance patterns to those typical of methicillin-resistant S. aureus were noted in that, although 29 strains were resistant to methicillin, penicillin, sulfamethizole, streptomycin, and tetracycline, the remainder of the strains were sensitive to streptomycin or tetracycline or both. In a majority of the strains (42 of 65), methicillin susceptibility testing by the disk method at 30 or at 37 degrees C in the presence of NaCl did not appear to enhance resistance expression. Most of the strains produced beta-lactamase (EC 3.5.2.6), but none of the 21 strains tested produced enterotoxin B.
Enzyme-linked immunosorbent assay for titration of Haemophilus influenzae capsular and O antigen antibodies
Authors: Dahlberg T , Branefors P
Published: January 2020

The enzyme-linked immunosorbent assay (ELISA) was elaborated for the detection of immunoglobulin M (IgM) and IgG antibodies against capsular and O antigens of Haemophilus influenzae. Purified capsular polysaccharide and lipopolysaccharide were used as antigens, with optimal coating concentrations being about 50 and 100 micrograms/ml, respectively. The antibody content was expressed as the highest serum dilution (-log10) showing an absorbance of 0.2 above the background level. The titers of hyperimmune sera (reference sera) ranged between 5 and 7 -log10. The sensitivity of the method was about 80 ng/ml with regard to anticapsular antibodies and 3 to 5 ng/ml with regard to anti-lipopolysaccharide antibodies. For detection of antibodies against capsular polysaccharide in sera obtained after primary immunization, ELISA was about 100-fold more sensitive than the indirect hemagglutination assay, whereas in hyperimmune sera, ELISA was about 10-fold more sensitive than the indirect hemagglutination assay. The sensitivity of ELISA for detecting anticapsular antibodies after primary and booster immunizations was 50-fold higher than that of the bactericidal assay using capsulated bacteria, whereas the sensitivity of the two methods was the same when hyperimmune sera were tested. ELISA performed with lipopolysaccharide as the antigen was about 50- and 150-fold more sensitive than the complement fixation and bactericidal assays tested with noncapsulated variants after primary injection and hyperimmunization, respectively.
Radioimmunoassay for Bacteroides fragilis infections
Authors: Hoppes W L , Rissing J P , Smith J W , White A C
Published: January 2020

Radioimmunoassay methods were evaluated for immunoglobulin G and immunoglobulin M antibodies against Bacteroides fragilis antigen. Of 12 serum samples from patients with B fragilis infections, 9 had higher concentrations of immunoglobulin G antibodies than any from 11 control subjects. Of 9 serum samples from infected patients, 6 had higher concentrations of immunoglobulin M than any from control subjects. Six serum samples from patients with Escherichia coli bacteremia did not contain elevated concentrations of immunoglobulin G or immunoglobulin M antibodies against B. fragilis antigen.
Hemagglutination Typing of
Escherichia coli:
Definition of Seven Hemagglutination Types
Authors: Evans Doyle J. , Evans Dolores G. , Young Lowell S. , Pitt Jane
Published: January 2020

A hemagglutination (HA) typing system has been developed for demonstrating and characterizing the mannose-sensitive and mannose-resistant hemagglutinins produced by
Escherichia coli
isolated from human sources. HA typing is performed by testing CFA agar-grown
E. coli
cells for HA with human, bovine, adult chicken, African Green monkey, and guinea pig erythrocytes in the presence and absence of mannose. Seven major HA types, designated HA type I through HA type VII, have been defined according to the HA patterns produced by 1,334 test cultures consisting of 33 colonization factor antigen I (CFA/I)-positive enterotoxigenic
E. coli
(ETEC), 37 CFA/II-positive ETEC, 614 isolates belonging to the classical enteropathogenic
E. coli,
or EPEC, serogroups, 446 non-ETEC, non-EPEC stool isolates, and 204 bacteremia-associated
E. coli.
Facultatively enteropathogenic
E. coli
(FEEC) serogroups, which are the causative agents of extraintestinal infections but also sporadic cases of enteritis, comprised 38% of the stool isolates and 91% of the blood isolates examined. Previous observations concerning the HA patterns of CFA-positive ETEC and the EPEC were confirmed. A significant correlation was found between FEEC serogroups and the production of mannose-resistant HA with human, monkey, and usually chicken erythrocytes (the HA patterns designated HA type VI). A large majority (80.2%) of the FEEC strains belonging to the most frequently isolated serogroups from cases of bacteremia (O1, O2, O4, O6, O7, and O18) produced type VI HA patterns. Stool isolates belonging to these same serogroups were 59.2% positive for HA type VI patterns. In contrast, only 17.4% of the non-FEEC stool isolates and 1.9% of the EPEC isolates belong to HA type VI. Of the blood isolates, the HA type VI phenotype was two times more prevalent among K1-positive
E. coli
than among K1-negative
E. coli,
70.6 versus 31.1%. These results suggest that surface-associated hemagglutinins of
E. coli,
many of which are known to be fimbriae, should be considered in addition to serotype (O:K:H antigenicity) in the description of isolates.
Comparison of passive hemagglutination, bactericidal activity, and radioimmunological methods in measuring antibody responses to Neisseria meningitidis group A capsular polysaccharide vaccine
Authors: Käyhty H
Published: January 2020

Passive hemagglutination (HA), a bactericidal activity test (BCA), and radioimmunoassay (RIA) were compared in measuring serum antibodies before and after group A meningococcal capsular polysaccharide vaccination of servicemen. The three methods were found satisfactory in demonstrating a response to vaccination in this age group. Of the postimmunization sera, 5% remained without HA and 1% remained without BCA activity; 1% of the postimmunization sera had less than 2 micrograms of antibody per ml as measured by RIA. Approximately 60% of the serum pairs showed a greater than or equal to 32-fold rise in HA titer, a greater than or equal 25-fold rise in BCA titer, or a greater than or equal to 4-fold rise in antibody concentration by RIA. A difference in response to two different vaccine lots was seen with RIA and BCA. Although the calculated correlation between the three methods was good, some individual sera gave discrepant results. These could be shown to be due mainly to one of the following factors: low HA titer was due to lack of the immunoglobulin M and A classes of antibodies, low BCA titer was due to the blocking effect of high immunoglobulin A content, and high BCA titer was due to antibodies directed to bacterial components other than the capsular polysaccharide.
Evaluation of four methods for isolation of Neisseria gonorrhoeae
Authors: Carlson B L , Haley M S , Tisei N A , McCormack W M
Published: January 2020

Bio-Bag (Marion Laboratories, Kansas City, Mo.) type C is made up of a ziplock plastic bag which contains a Thayer-Martin plate and a crushable CO2-generating ampoule. This system was compared with the candle extinction jar, Gono-Pak (Nasco, Fort Atkinson, Wis.), and JEMBEC (GIBCO Diagnostics, Lawrence, Mass.) systems to determine their efficiency and reliability for the isolation of Neisseria gonorrhoeae. A total of 191 anal and 130 urethral specimens were tested. There were 104 isolates of N. gonorrhoeae (24 anal and 80 urethral). The candle jar and Bio-Bag systems each detected 98 (94%) of the isolates. The Gono-Pak and JEMBEC systems detected 102 (98%) and 100 (96%) of the 104 isolates, respectively. These differences are not statistically significant. The Bio-Bag has the advantage of immediate CO2 release as compared with the Gono-Pak and JEMBEC systems, where CO2 production is dependent on the release of moisture from the medium. The Bio-Bag is a useful system, especially in situations where it is not convenient to use a candle jar.
Transfer of antirotaviral antibodies from mothers to their infants
Authors: McLean B , Holmes I H
Published: January 2020

Levels of rotavirus-specific immunoglobulin G (IgG), IgA, IgM, and secretory immunoglobulin in maternal and cord serum, colostrum and milk, and infants' stools were measured by enzyme-linked immunosorbent assay in 92 mothers and their infants. Although antirotaviral IgG, IgA, and secretory immunoglobulin were present in most maternal sera, only IgG crossed the placenta. All samples of colostrum and milk tested contained antirotaviral secretory immunoglobulin and IgA except those of two women in whom IgA deficiency was subsequently described. Specific IgM and IgG were also detected in many colostral samples. Antirotaviral IgA was detected in many colostral samples. Antirotaviral IgA was detected in stools of breast-fed but not bottle-fed neonates. Apparently the human infant receives rotaviral antibodies both transplacentally and via maternal colostrum and milk.
Indirect immunofluorescence antibodies to Legionella pneumophila: frequency in a rural community
Authors: Helms C M , Renner E D , Viner J P , Hierholzer W J , Wintermeyer L A , Johnson W
Published: January 2020

The background prevalence of indirect immunofluorescence antibody to Legionella pneumophila in a rural community was determined by testing sera from 517 volunteers. The upper limit of normal antibody titer was found to be 1:64 with L. pneumophila serogroup 1 (Philadelphia 1) used as antigen. High titers (greater than or equal to 1:128) were found in 13.2% of the sera and occurred with similar frequencies in males and females. In individuals 40 years of age and older, however, high titers were 2.7 times as prevalent in males as females.
Radiometric detection of yeasts in blood cultures of cancer patients
Authors: Hopfer R L , Orengo A , Chesnut S , Wenglar M
Published: January 2020

During a 12-month period, 19,457 blood cultures were collected. Yeasts were isolated from 193 cultures derived from 76 cancer patients. Candida albicans or Candida tropicalis accounted for 79% of isolates. Of the three methods compared, the radiometric method required 2.9 days to become positive, "blind" subculture required 2.6 days, and Gram stains required 1 day. However, the radiometric method was clearly superior in detecting positive cultures, since 73% of all cultures were first detected radiometrically, 22% were detected by subculture, and only 5% were detected by Gram stain. Although 93% of the isolates were detected by aerobic culture, five (7%) isolates were obtained only from anaerobic cultures. Seven days of incubation appear to be sufficient for the radiometric detection of yeasts.
Esculin-based medium for isolation and identification of Cryptococcus neoformans
Authors: Edberg S C , Chaskes S J , Alture-Werber E , Singer J M
Published: January 2020

A simple medium was developed, using esculin as the substrate, for the isolation and identification of Cryptococcus neoformans. C. neoformans produced a brown-black pigment on the medium; all other yeasts produced no pigment or were light yellow. Esculin is beta-glucose-6,7-dihydroxycoumarin. C. neoformans produced pigment because the 6,7-dihydroxycoumarin component of the esculin molecule was converted to a melanin-like pigment. We think the reaction was similar to the conversion of diphenols, aminophenols, and diaminobenzenes to melanin. Laboratory studies with isolates of C. neoformans, C. albidus, C. luteolus, and C. terreus and representatives of the genera Candida, Torulopsis, Geotrichum, and Rhodotorula, plus environmental field studies, demonstrated that over 95% of C. neoformans isolates were correctly identified, whereas all other fungi were excluded. Esculin agar was a sensitive, specific medium for the isolation and identification of C. neoformans. It was inexpensive and had a long storage life.
Use of a sensitive microplate enzyme-linked immunosorbent assay in a retrospective serological analysis of a laboratory population at risk to infection with typhus group rickettsiae
Authors: Halle S , Dasch G A
Published: January 2020

A microplate enzyme-linked immunosorbent assay (ELISA), developed for the detection of antibodies to typhus group rickettsiae, was used to analyze human sera from individuals engaged directly or indirectly in rickettsial research. The earliest serum available from each of 112 individuals was tested for immunoglobulin M (IgM) and IgG antibodies against Rickettsia typhi and Rickettsia prowazekii by ELISA at a 1:500 dilution. In at least one assay, nine sera had ELISA optical densities of greater than 0.2, which were above the mean optical densities plus three standard deviations of the other 103 sera. Three of the positive sera were from individuals with known clinical cases of typhus infection. The other sera with predominantly IgG titers were from individuals with extended laboratory exposure to rickettsiae or histories of typhus vaccination, or both. During continued serological surveillance, eight additional people with repeated occupational exposure to typhus rickettsiae had seroconversions in the ELISA to optical densities of greater than 0.2. No apparent clinical illness occurred in two individuals, whereas six clinical cases of infection occurred in others subsequent to accidental laboratory autoinoculation (one) or aerosol exposures (five). In the clinical infections, antibodies were first detected at 7 days, but in subsequent sera, rises and declines in titers were quite variable and were influenced by vaccination, relapse, and time and extent of antibiotic therapy. In primary infections the sera of several individuals who received immediate antibiotic therapy had brief strong IgM responses without pronounced increases in IgG. In contrast, much higher IgG levels were attained in three cases in which relapse occurred, the individual had previously been immunized, or treatment had been delayed. The microplate ELISA proved to be a highly sensitive and reliable test for detection of the human serological response to typhus antigens.
Further studies with the fluorescent treponemal antibody-absorption double-staining procedure
Authors: Mote P T , Hunter E F , Schubert C M , Feeley J C
Published: January 2020

A double-staining procedure for the fluorescent treponemal antibody-absorption test, using fluorescein isothiocyanate as a label for the class-specific anti-human globulin and tetramethylrhodamine isothiocyanate as a label for a counterstain reagent, has been described. This method requires the addition of a KP560 barrier filter, with a microscope equipped with vertical illumination, to exclude the rhodamine emission in reading the fluorescein fluorescence. The present study evaluated reversing the dye label for each conjugate in the double-staining procedure, thus eliminating the need for the KP560 filter. It also considered the possibility of shortening the counterstaining time and compared various methods for preparing antigen slides in an attempt to establish a method that increases the number of treponemes per microscopic field. The results indicate that a rhodamine-labeled class-specific anti-human globulin as a primary stain, and a fluorescein-labeled anti-treponemal globulin as a counterstain, provide an acceptable method for performing the fluorescent treponemal antibody-absorption double-staining procedure. Nonfixed antigen slides were held for 16 days in a desiccator or stored in plastic bags with silica gel for 3 weeks; then, with methanol fixation, they were used satisfactorily in the double-staining procedure. A shortened incubation time for the counterstain allowed more rapid slide processing.
Quantitative aerobic and anaerobic bacteriology of infected diabetic feet
Authors: Sapico F L , Canawati H N , Witte J L , Montgomerie J Z , Wagner F W , Bessman A N
Published: January 2020

Quantitative aerobic and anaerobic cultures of deep tissue were performed on amputated infected lower limbs of 13 diabetic patients immediately after surgery. Dissection was made through intact skin distant from any preexisting ulcer. The results were compared with those obtained from: (i) ulcer swabs (pre- and postamputation), (iii) curettage of the ulcer base, and (iii) needle aspiration after normal saline injection. Anaerobic transport media were used for anaerobic cultures before prompt transfer to the anaerobic chamber. A mean of 4.7 bacterial species per specimen was seen (2.3 aerobes, 2.4 anaerobes). Mean log10 growth per gram of tissue was as follows: (i) aerobes plus anaerobes = 6.99, (ii) aerobes = 6.42, and (iii) anaerobes = 7.65. There was poor concordance between the deep tissue culture results and the results from other modalities of culture collection, though the results from other modalities of culture collection, though the results from curettage and saline aspiration were slightly better than those obtained from ulcer swabs. The most frequently isolated organisms were enterococci, anaerobic streptococci, and species of Proteus, Clostridium, and Bacteroides. When anti-microbial therapy is indicated for this patient population, the possibility of the concomitant presence of aerobes as well as anaerobes should be considered.
Commercial latex agglutination test for rapid diagnosis of group B streptococcal infection in infants
Authors: Webb B J , Baker C J
Published: January 2020

Although latex agglutination assays for detection of a variety of bacterial antigens in body fluids from patients with systemic infection have been shown to be useful as rapid diagnostic techniques, lack of commercial availability has restricted their application. The Streptex latex test kit for the detection of group B streptococcal (GBS) antigen in admission body fluid specimens was evaluated for sensitivity and specificity in 54 infants with meningitis and in 10 infants with normal cerebrospinal fluid (CSF) parameters. GBS antigen was detected in 22 of 28 (78.6%) CSF specimens by latex agglutination and in 23 of 28 (82.1%) by countercurrent immunoelectrophoresis. Antigen was present in 21 of 28 (latex agglutination) and 19 of 26 (countercurrent immunoelectrophoresis) CSF specimens after the initiation of antimicrobial therapy. Heat-labile factors accounted for nonspecific agglutination reactions with latex suspensions other than group B in 3 of 28 CSF samples from patients with GBS meningitis. These nonspecific reactions were readily eliminated by heating specimens for 10 min at 100 degrees C. Fifteen patients with GBS meningitis had admission serum and urine samples collected in addition to CSF. Antigen was detected by latex agglutination and countercurrent immunoelelectrophoresis in 14 of 15 (93.3%) and 13 of 15 (86.7%) concentrated urine specimens, respectively, and in 12 of 15 (80%) CSF specimens and 4 of 15 (27%) sera by each method. These findings indicate that the Streptex latex test is a rapid, sensitive, and readily available method for detection of GBS antigen in admission body fluid specimens from infants with meningitis.
Optimal time for routine early subculture of blood cultures
Authors: Sliva H S , Washington J A
Published: January 2020

Routine aerobic subcultures performed between 6 and 12 h and between 12 and 17 h after blood collection yielded 36 and 63%, respectively, of isolates from blood cultures, whereas only 10% of isolates were recovered in a preliminary study when cultures were subcultured within 6 h of blood collection for cultures.
Rapid test for determination of esculin hydrolysis
Authors: Qadri S M , DeSilva M I , Zubairi S
Published: January 2020

An esculin hydrolysis test is described which distinguishes over 97% of bacteria that can convert esculin to esculetin in a buffered solution, from those that cannot, within an hour.
Quantitative relationships between Candida albicans in saliva and the clinical status of human subjects
Authors: Epstein J B , Pearsall N N , Truelove E L
Published: January 2020

Patients with candidiasis had greater than 400 colony-forming units per ml of saliva, whereas carriers of Candida albicans had less than 400 colony-forming units per ml. Thus, quantitative cultures of saliva may aid in the diagnosis of oral candidiasis.
Enzyme-linked immunosorbent assay for detection of antibody in volunteers experimentally infected with human coronavirus strain 229 E
Authors: Kraaijeveld C A , Reed S E , Macnaughton M R
Published: January 2020

An enzyme-linked immunosorbent assay was developed for detecting antibody rises to human coronavirus strain 229E and related strains in paired sera from infected volunteers. There was a close correlation between development of colds infected volunteers. There was a close correlation between development of colds and significant antibody rises detected by the enzyme-linked immunosorbent assay. Furthermore, the assay was more sensitive than a neutralization assay. This enzyme-linked immunosorbent assay is an easy, accurate, and sensitive assay for measuring significant antibody rises to human coronavirus strain 229E group viruses, and it could be useful in the clinical diagnosis of these infections.
Role of lipopolysaccharide in wheat germ agglutinin-mediated agglutination of Neisseria meningitidis and Neisseria gonorrhoeae
Authors: Frasch C E
Published: January 2020

Wheat germ agglutinin, having specificity for N-acetyl glucosamine, agglutinated known nonencapsulated Neisseria meningtidis strains, but failed to agglutinate encapsulated strains of all serogroups tested Presence of a capsule, therefore, blocked wheat germ agglutinin agglutination of N. meningitidis strains. In contrast, Neisseria gonorrhoeae strains were strongly agglutinated, providing additional evidence for nonencapsulation of N. meningitidis strains. In contrast, Neisseria gonorrhoeae strains were strongly agglutinated, providing additional evidence for nonencapsulation of N. gonorrhoeae. Purified lipopolysaccharide from a single N. meningitidis and N. gonorrhoeae strains tested. Thus, in absence of capsular polysaccharide wheat germ agglutinin agglutinates Niesseria strains through interaction with lipoplysaccharide in the outer membrane. Of 34 nongroupable throat N. meningitidis isolates, 10 failed to agglutinate in wheat germ agglutinin, suggesing that at least some nongroupable. N. meningitidis strains may possess capsule-like materials.
Evaluation of the Minitek system for identification of nonfermentative and nonenteric fermentative Gram-negative bacteria
Authors: Chester V , Cleary T J
Published: January 2020

The Minitek identification system (MT) was compared with a conventional testing battery for the characterization of 735 isolates which included 57 species and groups of nonfermentative (NF) and nonenteric fermentative (NEF) gram-negative bacteria. The MT correctly identified 585 of 616 NF (94,96%) and 115 of 119 NEF (96.65%) bacteria and 700 of 735 strains (95.24%) overall. A total of 31 NF and NEF (4.22%) bacteria were misidentified, and no identification was determined for four strains (0.69%). All strains of Acinetobacter anitratus, Pseudomonas maltophilia, P. fluroescens, and P. putida and all but one strain of P. aeruginosa were correctly identified. The most frequently misidentified taxa were CDC group Va-1, P. pickettii (Va-2), P. mendocina, and Moraxella urethralis (M-4). Supplemental tests were needed for the complete identification of 214 strains (29.11%). An average of 1.54 supplemental tests were used with each of these strains. A total of 134 strains (18.23%) had their identification delayed by 1 day due to supplemental testing. We recommend the use of the 42 degree C growth test with the MT. When used in accord with the manufacturer's instructions and with the MT code book the MT was found to be a valuable system for the identification of a wide variety of common and infrequently encountered NF and NEF bacteria.
Role of a cefoxitin-inducible beta-lactamase in a case of breakthrough bacteremia
Authors: Beckwith D G , Jahre J A
Published: January 2020

Development of resistance during therapy with cefamandole contributes to treatment failure. A simple cefoxitin disk test was recently described which detects a cefamandole-active inducible beta-lactamase not otherwise detectable with cefamandole as the inducer. A case of breakthrough Enterobacter bacteremia due to selection of a resistant subpopulation is reported in an immunocompromised patient. The use of this simple disk test in selected clinical cases is advocated.
Recovery of pathogenic bacteria from cerebrospinal fluid
Authors: Murray P R , Hampton C M
Published: January 2020

We studied the conditions necessary for optimal recovery of bacteria from cerebrospinal fluid. Our results indicated that Streptopcoccus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae can be quantitatively recovered in the sediment after centrifugation at 1,500 X g for 15 min. Equivalent numbers of bacteria were recovered by centrifugation or filtration of antibiotic-free cerebrospinal fluid; however, bacterial recovery by filtration was less effective with antibiotic-supplemented cerebrospinal fluid.
Evaluation of the necessity for routine terminal subcultures of previously negative blood cultures
Authors: Campbell J , Washington J A
Published: January 2020

It has been recommended that blood cultures be routinely subcultured aerobically on the day after the specimen is received, anaerobically after 48 h, and, finally, after 5 to 7 days if the cultures appear negative (Bartlett et al., Cumitech 1, American Society for Microbiology, Washington, D.C., 1974). To evaluate the necessity for the final routine subculture, 2,780 previously negative blood culture bottles were subcultured after 7 days of incubation. Of four bottles positive by subculture, three yielded the same organism as previously isolated from the companion bottle, and one yielded an organism considered to represent a contaminant. Since the routine 7-day subculture did not significantly increase the yield from previously negative blood cultures, the time and expense of the terminal subculture appears not to be warranted. Whereas a total of 7 days of incubation of blood cultures is probably adequate for general hospitals, a second week of incubation appears indicated in selected cases of suspected endocarditis and persistent or recurrent infection, as well as in any referral center. Candida and fastidious gram-negative bacilli, such as Haemophilus, Cardiobacterium, and Actinobacillus, usually require extended incubation for their detection.
Serological groups among untypable bovine isolates of Pasteurella haemolytica
Authors: Frank G H
Published: January 2020

Ten Pasteurella haemolytica isolates from the nasal passages of cattle, untypable by the indirect hemagglutination procedure, were grouped into three serotypes by the rapid plate agglutination procedure. Serological specificity and serum absorption results showed that the 10 indirect hemagglutination-negative isolates belonged to three distinct serotypes and were not members of established serotypes that lack the specific soluble antigen that forms the basis of serotyping by indirect hemagglutination. All isolates were biotype A.
Isolation of a stable cell wall-defective form of Neisseria gonorrhoeae from a case of untreated gonococcal urethritis
Authors: Hickman R K , Lawson J W
Published: January 2020

A cell wall-defective form of Neisseria gonorrhoeae from an exudate of an untreated patient with gonococcal urethritis was isolated on medium containing 7% polyvinylpyrrolidone. Initial attempts to grow the organism by standard microbiological methods had failed. This isolate was incapable of reversion to a normal gonococcus even after numerous subcultures and appeared to be a stable cell wall-defective form.
Correlation of proteolytic activity of Pseudomonas aeruginosa with site of isolation
Authors: Janda J M , Atang-Nomo S , Bottone E J , Desmond E P
Published: January 2020

Pseudomonas aeruginosa isolates were evaluated for protease activity by use of a semiquantitative plates assay. Differences were noted with respect to site of isolation, origin, and colonial morphology.
Comparison of diffusion-in-gel enzyme-linked immunosorbent assay with conventional serological methods for detection of class-specific antibodies to Salmonella typhi O antigen
Authors: Lange S , Elwing H , Larsson P , Nygren H
Published: January 2020

The diffusion-in-gel enzyme-linked immunosorbent assay (DIG-ELISA) is a new and simple method for quantitation of antibodies, based on the ability of antibodies to diffuse from wells in gel and adsorb to antigen which is bound to a polystyrene surface. The antigen-antibody reaction is visualized with a color reaction caused by horseradish peroxidase-conjugated class-specific anti-immunoglobins. This method was used to study the immunoglobulin G, A, and M immune response to Salmonella typhi O antigen in individuals immunized with a monovalent heat-inactivated typhoid vaccine. The antibody values obtained by the DIG-ELISA method correlated with those evaluated by conventional direct agglutination (Widal) and indirect hemagglutination methods. The DIG-ELISA method was also found to be sensitive, specific, and economical, as well as suitable for handling large numbers of sera while requiring very simple equipment.
Rapid and reliable identification of Staphylococcus aureus by a latex agglutination test
Authors: Essers L , Radebold K
Published: January 2020

A latex slide agglutination test detecting clumping factor and protein A simultaneously is recommended for rapid and reliable routine identification of Staphylococcus aureus. Strains (836) of staphylococci isolated from clinical specimens were examined, all S. aureus strains identified by conventional methods were correctly differentiated by the latex test, and no false-positive results occurred with other staphylococci. The reagent is easy to prepare since plasma is the coating material.
Aminopeptidases highly specific for glutamyl residues from Neisseria meningitidis and Moraxella urethralis
Authors: Eriquez L A , Knight G B
Published: January 2020

Cell-associated glutamyl aminopeptidase activity was detected in several strains of Neisseria meningitidis and Moraxella urethralis grown in liquid culture. Enzymatic activity was released from washed cells by ultrasonic treatment and monitored fluorometrically by measuring the release of aryl groups from 17 different aminoacyl-beta-naphthylamides. Substrates containing a glutamyl moiety were readily hydrolyzed by both N. meningitidis and M. urethralis. Glutamyl aminopeptidase activity was partially purified from crude sonicates by means of ion-exchange and gel chromatography, and samples were examined by polyacrylamide gel electrophoresis. Kinetic and pH studies were performed to partially characterize activities. The molecular weight of the M. urethralis enzyme was approximately 88,000, whereas the apparent molecular weight of the N. meningitidis enzyme was shown to be in excess of 200,000. M. urethralis produced two glutamyl aminopeptidases, one specific for a gamma-glutamyl moiety, the other specific for an alpha-glutamyl moiety. In contrast, N. meningitidis produced a single glutamyl aminopeptidase which hydrolyzed alpha- and gamma-glutamyl-substituted beta-naphthylamides.
Aberrant Forms of
Escherichia coli
in Blood Cultures: In Vitro Reproduction of an In Vivo Observation
Authors: Magnussen C. Richard , Hruska Jerome F.
Published: January 2020

Aberrant filamentous forms of
Escherichia coli
were observed on direct Gram stain of blood cultures from a patient being treated with the beta-lactam antibiotic cephalexin. After the institution of an alternative antibiotic regimen which included a different cell wall-active agent,
E. coli
of normal morphology was detected in blood cultures for an additional 48 h. Filamentous forms of
E. coli
could be reproduced reliably in vitro by incubating the organism in Mueller-Hinton broth containing various concentrations of cephalexin. Both supra- and subinhibitory concentrations of cephalexin resulted in filament formation after 4 h of incubation, whereas 24 h of incubation yielded intact filaments at only a narrow range of subinhibitory concentrations of cephalexin. In vitro comparison of the ability of cephalexin, cephalothin, ampicillin, and gentamicin to cause filamentous forms of
E. coli
showed that cephalexin and cephalothin produced pure filament formation after 4 h of incubation at subinhibitory concentrations of as low as one-fourth the minimum inhibitory concentration of the antibiotic. Ampicillin was not associated with pure filament formation at concentrations below the minimum inhibitory concentration, and gentamicin produced no filaments at any concentration. The effect of preincubation of
E. coli
with subinhibitory concentrations of cephalexin on subsequent minimum inhibitory concentrations of ampicillin was examined in an effort to develop an explanation for the persistent sepsis exhibited by the patient. No diminution of the activity of ampicillin by preincubation with cephalexin could be demonstrated. Other possible clinical implications of filamentous forms of gram-negative bacilli are discussed.