bluuebunny/crossref_metadata_2025 huggingface dataset:
Concomitance of cytotoxigenic and non-cytotoxigenic Clostridium difficile in stool specimens
Authors: Borriello S P , Honour P
Published: January 2020

Six patients with antibiotic-associated diarrhea and one patient with diarrhea unrelated to antibiotic use yielded both cytotoxigenic and non-cytotoxigenic isolates of Clostridium difficile from the same stool specimens. In addition, these isolates were shown to be pathogenic and nonpathogenic, respectively, in the hamster model of antibiotic-associated colitis. These data imply that more than one toxin type of C. difficile may be harbored simultaneously. If toxin testing is used to identify C. difficile, more than one colony must be tested.
Efficiency of various bile salt preparations for stimulation of Clostridium difficile spore germination
Authors: Wilson K H
Published: January 2020

Taurocholate, desoxycholate, and cholate stimulated germination of Clostridium difficile spores in broth medium and enhanced recovery of C. difficile spores on a selective agar medium. Desoxycholate and some crude taurocholate preparations also inhibited multiplication of vegetative cells. At a concentration of 1.2 X 10(-2) M, sodium cholate inhibited multiplication of vegetative cells, but at concentrations of 1.2 X 10(-3) to 2.4 X 10(-3) M, it stimulated germination without inhibiting cell multiplication. Thus, pure sodium taurocholate and sodium cholate may effectively be incorporated in cefoxitin-cycloserine-fructose agar, whereas some crude preparations of sodium taurocholate decrease recovery on this medium.
Hemagglutination treponemal test for syphilis
Authors: Friedly G , Zartarian M V , Wood J C , Floyd C M , Peterson E M , de la Maza L M
Published: January 2020

Sera from 290 hospital patients were tested to compare the sensitivity, specificity, and reproducibility of the hemagglutination treponemal test for syphilis (HATTS) with the fluorescent treponemal antibody absorption test (FTA-ABS). Complete agreement was obtained between the methods when 142 syphilitic sera from patients with various stages of syphilis were tested. By using clinical histories, the specificity with 148 nonsyphilitic sera was determined to be 100% for the HATTS and 96.6% (143 of 148) for the FTA-ABS. Satisfactory reproducibility was obtained with both methods. Compared with the FTA-ABS, the HATTS was more specific, easier, and more economical to perform. We therefore recommend the HATTS as a suitable alternative to the FTA-ABS.
Granada medium for detection and identification of group B streptococci
Authors: De La Rosa M , Villareal R , Vega D , Miranda C , Martinezbrocal A
Published: January 2020

A new starch serum medium, Granada medium, for isolation and identification of group B streptococci (GBS) anaerobically as red colonies is described. The medium contains 3.8% Proteose Peptone no. 3 (Difco), 15% soluble starch 1252 (Merck), 10% coagulated horse serum, 15 micrograms of trimethoprim per ml, and 0.06 M phosphate buffer (pH 7.8; medium pH 7.4). This medium inhibited fecal flora and at the same time supported growth of GBS. A new pigment-enhancing effect of folate inhibitors on GBS is reported and used in the formulation of the medium. The good selective and differential properties of the Granada medium favor quicker and easier detection of GBS in heavily contaminated specimens. Since the medium is convenient to use and requires only 18 h of incubation to detect and identify GBS, it should be useful in any clinical microbiology laboratory and would assist in the early detection of GBS in clinical specimens.
Improved GM1-enzyme-linked immunosorbent assay for detection of Escherichia coli heat-labile enterotoxin
Authors: Ristaino P A , Levine M M , Young C R
Published: January 2020

Previously described GM1 ganglioside enzyme-linked immunosorbent assays (GM1-ELISA) for the detection of Escherichia coli heat-labile enterotoxin (LT) showed sensitivity equal to the Y-1 adrenal cell assay when anti-LT (a reagent not commercially available) was used. However, when antitoxin to immunologically related (commercially available) cholera toxin was substituted, a marked loss in sensitivity occurred. We modified the GM1-ELISA that employed anti-cholera toxin to make it comparable in sensitivity to the Y-1 adrenal cell assay. When five media commonly used for LT production were compared, Mundell's Casamino Acids medium was shown to be significantly superior. Lincomycin (45 micrograms/ml) added to E. coli cultures significantly increased net optical densities in the GM1-ELISA, a direct measure of the amount of LT. Treatment of broth cultures or bacterial cell pellets with polymyxin B or extension of culture time to 48 h also significantly increased net optical density by allowing enhanced release of periplasmic LT. A major innovation involved the direct culture of E. coli strains in GM1-coated wells of microtiter plates followed by ELISA. This direct culture method GM1-ELISA (DCM-GM1-ELISA) saved not only assay time, but also materials and reagents. The net optical densities that result from this assay allow the test to be read visually without a spectrophotometer. Three independent observers read plates with E. coli tested by DCM-GM1-ELISA. Thirty-four of 35 adrenal cell-positive strains (97% sensitivity) and 30 of 30 LT-negative control E. coli strains (100% specificity) were identified by all three observers reading coded plates. The DCM-GM1-ELISA provides a simple, practical and efficient assay for LT for less sophisticated laboratories.
Hydrogenase activity in catalase-positive strains of Campylobacter spp
Authors: Goodman T G , Hoffman P S
Published: January 2020

A rapid hydrogenase assay has been developed which may be useful in separating the species Campylobacter jejuni and C. coli from the subspecies C. fetus subsp. fetus and C. fetus subsp. venerealis. This assay employs the impermeant redox dye benzyl viologen, and positive determinations can be made within 20 min. All strains of C. jejuni and C. coli were found to be strongly hydrogenase positive. All strains of C. fetus subsp. fetus and C. fetus subsp. venerealis were negative for hydrogenase when the assay was performed at a benzyl viologen concentration of 2 mM and an incubation temperature of 30 degrees C. Some strains of C. fetus had low levels of hydrogenase as determined with cell extracts but were hydrogenase negative by the benzyl viologen assay. Since there are few rapid diagnostic tests available for screening Campylobacter isolates, we hope that the rapid hydrogenase assay will prove useful.
Early detection of positive blood cultures by the acridine orange staining technique
Authors: Tierney B M , Henry N K , Washington J A
Published: January 2020

Staining 2,205 macroscopically negative blood cultures with acridine orange after 6 to 17 h of inoculation and incubation was as sensitive as an early subculture in detecting positive blood cultures. Of the 179 positive blood cultures, 30 (16.8%) were detected by acridine orange alone, 19 (10.6%) were detected by early subculture alone, 84 (46.9%) were detected by both techniques, and 46 (25.7%) were not detected by either method. The latter group includes cultures that became positive after 48 h of incubation. Acridine orange staining of smears prepared from macroscopically negative blood cultures after 6 to 17 h is a rapid, reliable method to detect positive blood cultures.
Viability of Trichomonas vaginalis in vitro at four temperatures
Authors: Smith R F
Published: January 2020

The effect of temperature as a possible factor on the survival of Trichomonas vaginalis for shipment or routine laboratory maintenance was studied. Ten strains of T. vaginalis, ATCC 30001, ATCC 30238, and eight clinical isolates, were examined for viability when kept incubated at 37 degrees C or removed from this temperature and held at 42, 22, or 5 degrees C for increasing lengths of time without subculture or reincubation at 37 degrees C. The order in which the strains remained viable without subculture was: 5 degrees C, 8 to 10 days; 22 degrees C, 4 to 8 days; 37 degrees C, 4 to 6 days; 42 degrees C, less than 2 days. Vials of medium with cells were also held at 22 and 5 degrees C and then reincubated at 37 degrees C. Cultures held at 22 degrees C remained viable 6 to 8 days, whereas those stored at 5 degrees C remained viable 10 to 14 days. These data show that T. vaginalis withstands a wide range of temperatures, particularly below normal growth temperatures without subcultures, beyond what would be expected in mailing cultures.
pH and water content of Pseudomonas aeruginosa- and Klebsiella pneumoniae-Colonized Perineal Skin of Men with spinal cord injuries
Authors: Montgomerie J Z , Schick D G , Gilmore D S , Graham I E
Published: January 2020

Men with spinal cord injuries have a high incidence of Pseudomonas aeruginosa colonization of the perineum. Studies were carried out to determine whether colonization with Pseudomonas aeruginosa or Klebsiella pneumoniae is associated with changes in the pH or surface moisture of the perineal skin. Increased skin moisture correlated with a higher pH (P less than 0.01). In patients using the external urinary collection system, the pH was significantly higher on the perineum of patients colonized with P. aeruginosa or K. pneumoniae than on the perineum of patients not colonized with these bacteria. There was no correlation between moisture and colonization.
Evaluation of the Bacteriuria Detection Device
Authors: Hoyt S M , Ellner P D
Published: January 2020

The ability of the Bacteriuria Detection Device (BDD) (Marion Laboratories, Kansas City, Mo.) to detect significant bacteriuria was evaluated. Quantitative plating and BDD results were compared for 513 clinical specimens, 188 of which were voided. Eighty-seven specimens (17%) could not be tested because of clogging or excessive pigmentation. Specimens were considered positive if they contained more than 10(4) bacteria per ml. Thirteen specimens gave false-negative BDD results; 10 of these contained gram-positive cocci. The sensitivity of the BDD test was calculated to be 89%; the specificity, 65%. The predictive value of a negative test was 94%; that of a positive test was 49%. The efficiency of the BDD test was 71.6%. The BDD has the potential for providing rapid detection of bacteriuria, but requires further improvement before it can reliably be substituted for urine culture.
Routine aerobic terminal subculturing of blood cultures in a cancer hospital
Authors: Kiehn T E , Wong B , Edwards F F , Armstrong D
Published: January 2020

Routine terminal aerobic subcultures of macroscopically negative blood culture bottles were evaluated during a 15-month period when 30,000 blood cultures were processed. Each blood culture set consisted of a vented and an unvented 50-ml broth bottle. Forty-eight pathogens and 47 contaminants were isolated only from terminal subcultures. Twenty-two of the significant isolates were yeasts (usually recovered from vented bottles), and 10 were Pseudomonas aeruginosa (usually recovered from unvented bottles). Blood cultures that were positive by terminal subculture provided clinically relevant information in many cases, whether other blood cultures were positive or not. Microbiology laboratories, particularly those in hospitals where yeasts and P. aeruginosa are commonly isolated from blood specimens, should evaluate carefully the need for terminal subcultures of blood culture bottles before abandoning their use.
Production of monoclonal antibodies to Legionella pneumophila serogroups 1 and 6
Authors: Para M F , Plouffe J F
Published: January 2020

To better define the surface antigens of Legionella pneumophila for clinical and experimental purposes, we have produced monoclonal antibodies to L. pneumophila serogroups 1 and 6. Two hybridomas were produced in serogroup 1. One antibody, LP-I-17, recognized a serogroup-common antigen. The second antibody, LP-I-81, was specific for serogroup 1. This antibody was able to agglutinate bacterial cells belonging to the serogroup 1 reference strains. Philadelphia and Knoxville. Microagglutination assays of environmental and clinical isolates revealed a subgroup of serogroup 1 environmental isolates which were not agglutinated by LP-I-81. This subset of isolates was segregated to certain buildings in the medical complex. Immunodiffusion studies showed identity between the LP-I-81 antigen and the serogroup-specific antigen of serogroup 1 organisms. This antigen could be absorbed out of the serogroup 1 organism extract with LP-I-81-coated Staphylococcus aureus, leaving the serogroup-common antigens. Three hybridomas were produced to serogroup 6. All three produced antibodies which were serogroup 6 specific and agglutinated serogroup 6 bacteria.
Spin membrane immunoassay for use in meningococcal serology
Authors: Vistnes A I , Rosenqvist E , Frøholm L O
Published: January 2020

A modified and improved spin membrane immunoassay has been developed for detecting complement-activating antibodies to Neisseria meningitidis capsular polysaccharide antigens. The polysaccharides were incorporated in the membranes of large unilamellar vesicles prepared by the reverse-phase evaporation method and filled with the water-soluble spin label tempocholine chloride. Upon addition of group-specific antisera and complement, the lipid membrane was damaged and the spin label leaked out. This process was monitored by electron spin resonance spectroscopy. A satisfactory assay was developed for polysaccharides of group A and C, whereas in the case of the B system the assay was more labile. The method is rapid and has a sensitivity comparable to that of radioimmunoassay. When studying paired sera from five recruits vaccinated with an A + C polysaccharide vaccine, significant rises in titers to both A and C polysaccharides were observed in all the postvaccination sera.
Evaluation of liquid and lyophilized preservatives for urine culture
Authors: Weinstein M P
Published: January 2020

Culture results of urine specimens transported conventionally (sterile cup) and in a commercial liquid or an investigational lyophilized preservative were compared in a hospital that experiences substantial delays in specimen transport to the laboratory (greater than 40% of specimens received after a delay of greater than or equal to 2 h). At the time of initial plating in the laboratory, 106 of 111 (95.5%) specimens that were positive (greater than or equal to 10(5) CFU of a single organism per ml in pure culture) after conventional transport were also positive in liquid preservative. After a 24-h holding period (cup refrigerated, preserved urine at room temperature), agreement was 91.4% (96 of 105). At the time of initial plating, agreement between results obtained by the conventional method and those obtained by using lyophilized preservative was 96.9% (63 of 65); after 24 h, agreement was 92.4% (61 of 67). Complete inhibition of growth of three Klebsiella pneumoniae isolates was observed in liquid preservative; however, urine processed in the lyophilized preservative did not show inhibition. The proportion of urine cultures showing no change in quantitative growth between the time of initial plating and repeat plating at 24 h was virtually identical for all three processing methods (83.6 +/- 0.9%). After the 24-h holding period, specimens processed in lyophilized preservative were less likely to show diminished quantitative growth than were specimens processed conventionally or in liquid preservative but were more likely to show an increase in growth of greater than or equal to 1 log. Nonetheless, the apparent lack of toxicity of lyophilized preservative may make it preferable to the currently available liquid preservative.
Lactose-fermenting, multiple drug-resistant Salmonella typhi strains isolated from a patient with postoperative typhoid fever
Authors: Kohbata S , Takahashi M , Yabuuchi E
Published: January 2020

Two lactose-fermenting Salmonella typhi strains were isolated from bile and blood specimens of a typhoid fever patient who underwent a cholecystectomy due to cholelithiasis. One lactose-fermenting S. typhi strain was also isolated from a pus specimen which was obtained at the tip of the T-shaped tube withdrawn from the operative wound of the common bile duct of the patient. These three lactose-fermenting isolates: GIFU 11924 from bile, GIFU 11926 from pus, and GIFU 11927 from blood, were phenotypically identical to the type strain (GIFU 11801 = ATCC 19430 = NCTC 8385) of S. typhi, except that the three strains fermented lactose and failed to blacken the butt of Kligler iron agar or triple sugar iron agar medium. All three lactose-fermenting strains were resistant to chloramphenicol, ampicillin, sulfomethoxazole, trimethoprim, gentamicin, cephaloridine, and four other antimicrobial agents. The type strain was uniformly susceptible to these 10 drugs. The strain GIFU 11925, a lactose-negative dissociant from strain GIFU 11926, was also susceptible to these drugs, with the sole exception of chloramphenicol (minimal inhibitory concentration, 100 micrograms/ml).
Rapid immunoperoxidase assay for detection of respiratory syncytial virus in nasopharyngeal secretions
Authors: Cevenini R , Donati M , Moroni A , Franchi L , Rumpianesi F
Published: January 2020

Samples of nasopharyngeal secretions obtained from 70 infants and young children with acute respiratory disease were examined for the presence of respiratory syncytial virus by immunoperoxidase assay (IPA). The IPA was compared with the immunofluorescence assay and with cell culture isolation. Respiratory syncytial virus antigen-positive cells were detected by both IPA and immunofluorescence assay in 28 specimens; 25 samples were positive in cell culture. The agreement between virus isolation and IPA and IFA was 89%. The applicability of IPA to rapid viral diagnosis of respiratory syncytial virus infection is discussed.
Growth characteristics of large- and small-colony types of Mycoplasma mycoides subsp. mycoides on 5% sheep blood agar
Authors: Thigpen J E , Cottew G S , Yeats F , McGhee C E , Rose D L
Published: January 2020

Mycoplasma mycoides subsp. mycoides of the large-colony (LC) type was isolated in pure culture on 5% sheep blood agar plates inoculated with lung specimens from a 4-month-old Toggenburg goat. The growth characteristics of this isolate, of four known LC types, and of five known small-colony (SC) types of M. mycoides subsp. mycoides were compared on 5% sheep blood agar at 2, 5, and 7 days. The SC types were not visible at 2 days and did not grow larger than 0.1 mm, whereas the LC types were visible in 2 days and increased in diameter over 7 days to between 0.4 and 0.7 mm. These results indicate that growth on 5% sheep blood agar can be used as an additional marker in differentiating LC and SC types of M. mycoides subsp. mycoides.
Biochemical markers of the penicillin-induced L phase of a group B, type III Streptococcus sp
Authors: Flores A E , Ferrieri P
Published: January 2020

The penicillin-induced L phase of growth of the group B, type III streptococcal strain 76-043 was examined for biochemical properties used for the identification of group B streptococci. After numerous serial subcultures in the cell wall-defective state, this stable L phase continued to produce hemolysin, hippuricase, and CAMP factor in addition to the group- and type-specific antigens. Hemolysin production by the L-phase cells was observed on solid and in liquid media containing sheep erythrocytes. Washed whole L-phase cells hydrolyzed hippuric acid. CAMP factor was detected by the characteristic hemolysis produced on blood agar by L-phase cells or filtered culture supernatants. CAMP factor activity was quantitated by an agar well diffusion system and a macrotube assay with partially purified preparations of CAMP factor and staphylococcal beta-hemolysin. Hyperimmune cow serum neutralized the CAMP activity of the L phase and parent bacterial phase to the same degree, suggesting identity of the CAMP factors. Production of hemolysin, hippuricase, and CAMP factor confirmed the bacterial origin of this L phase. Assay for these biological markers could be used to identify L-phase organisms derived from group B streptococci.
Evaluation of the Cult-a-Box gas generator system for isolation of Campylobacter spp. from stool specimens
Authors: Kosunen T U
Published: January 2020

The Cult-a-Box gas generator tablet method for isolating Campylobacter spp. from stool cultures was evaluated by comparison with a standard gas mixture of 5% oxygen, 10% carbon dioxide, and 85% nitrogen. Of the 186 positive cultures, 90.3% were found by both methods. Of the remaining 9.7% which were positive in one system only, 11 were found by the tablet method and 7 by the standard gas method.
Serotyping of Streptococcus pneumoniae strains by coagglutination and counterimmunoelectrophoresis
Authors: Trollfors B , Burman L , Dannetun E , Llompart J , Norrby R
Published: January 2020

A total of 217 Streptococcus pneumoniae strains were serotyped by coagglutination (COA) and counterimmunoelectrophoresis (CIE). With all strains tested, there was full agreement between results obtained by COA and CIE, except for strains belonging to serotypes 7, 14, 33, and 37, which could not be typed by CIE. These strains were serotyped by passive immunodiffusion, results of which were in full agreement with those obtained by COA. Besides having the advantage of identifying strains belonging to all serotypes, COA was also more rapid and economical than CIE.
Accuracy of the KOH and vancomycin tests in determining the Gram reaction of non-enterobacterial rods
Authors: von Graevenitz A , Bucher C
Published: January 2020

Two nonstaining tests for the Gram reaction, the KOH and vancomycin disk (5 micrograms) tests, were employed on 488 strains of aerobic gram-negative and gram-positive rods. Since each test may yield false results with certain species, the use of a combination is suggested.
Effect of ferrous sulfate, sodium metabisulfite, and sodium pyruvate on survival of Campylobacter jejuni
Authors: Chou S P , Dular R , Kasatiya S
Published: January 2020

A combination of ferrous sulfate, sodium metabisulfite and sodium pyruvate, incorporated in solid medium, maintained the characteristic morphology, motility, and viability of six isolates of Campylobacter jejuni stored at room temperature and 4 degrees C for up to 20 and 30 days, respectively, under normal atmospheric conditions.
Campylobacter fetus subsp. fetus in homosexual males
Authors: Devlin H R , McIntyre L
Published: January 2020

Campylobacter fetus subsp. fetus was isolated from the stools of two homosexual males. One was asymptomatic at the time of isolation. The other presented with diarrhea. Both isolates were initially grown at 42 degrees C. This organism should be included among the list of organisms that are found in homosexual males.
Serogrouping and subtyping of Legionella pneumophila with monoclonal antibodies
Authors: Joly J R , Chen Y Y , Ramsay D
Published: January 2020

Monoclonal antibodies directed against Legionella pneumophila serogroups 1 to 6 were produced by fusing splenocytes of BALB/c mice with the Sp 2/0-Ag14 or the NSO mouse myeloma cell lines. Specificity of these antibodies was determined by indirect fluorescent-antibody staining: 8 reacted with L. pneumophila serogroup 1 and, respectively, 13, 6, 6, 5, and 10 reacted with serogroups 2, 3, 4, 5, and 6; all except 5 were serogroup specific, and none presented cross-reactions with six other species of Legionellaceae. Serogroup determination of 35 isolates of L. pneumophila with seven selected monoclonal antibodies resulted in correct serogrouping in all instances; a pool of the same seven monoclonal antibodies stained intensely all strains of L. pneumophila without any staining of the other species of Legionellaceae. When 24 serogroup 1 isolates of L. pneumophila were stained with eight serogroup 1-specific monoclonal antibodies, the staining patterns could be clustered in five distinct groups. These hybridomas thus represent an unlimited source of standard reagent that could be used in the detection and serogrouping of L. pneumophila; differences in staining patterns could be used as epidemiological markers for these bacteria.
Colonization of bacteria on polyvinyl chloride and Teflon intravascular catheters in hospitalized patients
Authors: Sheth N K , Franson T R , Rose H D , Buckmire F L , Cooper J A , Sohnle P G
Published: January 2020

During an 8-month period all intravascular catheters were removed by sterile technique upon completion of use and submitted to the hospital microbiology laboratory. All catheters were routinely cultured by the semiquantitative culture technique, with greater than or equal to 15 colonies being defined as a positive result. Of the 687 Teflon catheters cultured, 6.9% were positive by culture, compared with 24.6% of 77 polyvinyl chloride catheters (P less than 0.001). Also, colonization of coagulase-negative staphylococci on polyvinyl chloride was more than on Teflon. These data suggest that polyvinyl chloride catheters are colonized more frequently with organisms than are Teflon catheters; additionally, there is an increased affinity of coagulase-negative staphylococci for polyvinyl chloride as compared with Teflon, substantiating our previous observations with an in vitro system. We conclude that the type of catheter material may be important in determining the incidence of catheter-related infections and in selective colonization by coagulase-negative staphylococci.
Cellular fatty acid composition of Pseudomonas marginata and closely associated bacteria
Authors: Dees S B , Hollis D G , Weaver R E , Moss C W
Published: January 2020

The cellular fatty acid compositions of the lectotype strain and four clinical isolates of Pseudomonas marginata were determined by gas-liquid chromatography and compared with 11 strains of the Centers for Disease Control Pseudomonas-like group 2, which are similar to P. marginata in a number of conventional biochemical tests. Isolates of P. marginata were readily distinguished from Pseudomonas-like group 2 by the presence of a C17:0 cyclopropane acid and hydroxy acids 3-OH-C14:0, 2-OH-C16:0, 3-OH-C16:0, and 2-OH-C18:1, whereas strains of Pseudomonas-like group 2 contained C16:1 delta 9 as a major acid with small amounts of 3-OH-C12:0 and 2-OH-C14:0 acids. Our data show that cellular fatty acid composition provides useful additional information that can be combined with selected conventional tests to provide a more reliable and rapid identification of P. marginata and related bacteria.
O serotyping scheme for Enterobacter cloacae
Authors: Gaston M A , Bucher C , Pitt T L
Published: January 2020

A serotyping scheme for Enterobacter cloacae based on heat-stable somatic antigens is described. A total of 28 antisera were prepared in rabbits, and titers of agglutinins were high (greater than 640). Some cross-reactions were observed, and 11 sera required absorption before routine use. Of 300 clinical isolates from 66 hospitals, 77.6% were typable, 11.4% were not agglutinated by any of the sera, and 11.0% were autoagglutinable in saline. The eight most frequent serotypes were O3 (21.3%), O8 (13.3%), O1 (7.6%), O13 (5.0%), O9 (4.7%), O10 (3.0%), O16 (3.0%), and O25 (3.0%).
Reliability of in vitro susceptibility tests for detecting coagulase-negative staphylococcal resistance to penicillinase-resistant semisynthetic penicillins
Authors: Lowy F D , Chang D S , Aning V , Williams S , Szilagyi G
Published: January 2020

The reliabilities of five in vitro susceptibility tests (agar dilution, broth microdilution, automated MS-2, Kirby-Bauer disk diffusion, and ability to grow on methicillin-containing agar) to predict the susceptibility of 204 coagulase-negative staphylococcal isolates to penicillinase-resistant semisynthetic penicillins were compared. There was wide variation in susceptibility, with results ranging from 86.3% susceptible by MS-2 to 38.2% by growth on methicillin-containing agar. The results of the broth dilution techniques, including the MS-2, were significantly different (P less than 0.02) from the remaining tests. Nafcillin disks were less effective (P less than 0.02) than oxacillin disks in predicting resistance. Kirby-Bauer oxacillin disks and the ability to grow on methicillin-containing agar were the most reliable predictors of resistance. The MS-2 did not reliably predict resistance.
Comparison of three commercial cryptococcal latex kits for detection of cryptococcal antigen
Authors: Wu T C , Koo S Y
Published: January 2020

Three commercial latex kits, IBL, MYCO-Immune, and IMMY, for the detection of cryptococcal antigen were compared in regard to sensitivity, specificity, and height of antigen titers. A total of 218 cerebrospinal fluid and 79 serum specimens from 239 patients were included. Twenty-two patients had culture-proven disseminated cryptococcosis. Both the IBL and MYCO-Immune kits had sensitivities of 100%, and the IMMY kit had sensitivities of 82.6 and 45.4% in CSF and serum specimens, respectively. There was one false-positive reaction in serum with the MYCO-Immune kit and one false-negative reaction on screen only with all three kits. Rheumatoid factor-containing sera were used to check the agglutination titers between matching anti-cryptococcal globulin reagents and normal globulin reagents. The finding that agglutination titer with anti-cryptococcal globulin reagents was fourfold higher than with normal globulin reagents in the MYCO-Immune kit is considered to be a cause for a false-positive reaction in serum.
Rubella antibodies detected by several commercial immunoassays in hemagglutination inhibition-negative sera
Authors: Kleeman K T , Kiefer D J , Halbert S P
Published: January 2020

Although a very good correlation was found between the level of rubella antibodies measured by a standard hemagglutination inhibition (HI) test and by an enzyme-linked immunosorbent assay (ELISA) procedure (Cordia R), an appreciable proportion (31%) of ELISA-positive specimens were encountered among HI-negative sera. The reverse was rarely seen. Many of the HI-negative, ELISA-positive sera were also found to be positive for rubella antibodies by one or more other assay methods, including an immunofluorescence assay (IFA) procedure (FIAX), passive hemagglutination (PHA) (Rubacell and PHAST), latex agglutination (Rubascan), and a second ELISA procedure (Rubelisa). The specificity of all of the ELISA-positive HI-negative specimens was substantiated by absorption experiments. In these tests, the ELISA reactivities were blocked by rubella antigens, but not by a variety of tissue culture control antigens or by influenza virus grown on the same cell line. The findings indicate that many of the newer methods available for rubella antibody detection are more sensitive than HI for detecting low levels of rubella antibodies. Until more clinical information is available concerning the protective nature of these low levels of antibody, caution should be exercised in assessing the significance of these results.
Toluidine red unheated serum test, a nontreponemal test for syphilis
Authors: Pettit D E , Larsen S A , Harbec P S , Feeley J C , Parham C E , Cruce D D , Hambie E A , Perryman M W
Published: January 2020

We have shown that a modification of the color-coded antigen developed by Kasatiya and Lambert (Appl. Microbiol. 28:317-318, 1974) can be used as a substitute for other nontreponemal antigens used in screening tests for syphilis. The antigen is based on the Venereal Disease Research Laboratory antigen, with EDTA, choline chloride, and toluidine red toner added. Performance of the toluidine red unheated serum test (TRUST) is identical to that of the rapid plasma reagin 18-mm circle card test (U.S. Department of Health, Education, and Welfare, Public Health Service Publication no. 411). In a series of preliminary evaluations, the TRUST antigen was found to be stable over a period of 6 months at 4 degrees C. In a comparison of TRUST with the rapid plasma reagin card test, the qualitative agreement was 100%, whereas agreement between these two tests and the Venereal Disease Research Laboratory slide test was 99.7%. The quantitative agreement +/- 1 twofold dilution between TRUST and the rapid plasma reagin card test was 100%; between TRUST and the Venereal Disease Research Laboratory slide test it was 75.0%; and between the rapid plasma reagin card and Venereal Disease Research Laboratory slide tests it was 60.0%.
Evaluation of solubilized herpes simplex virus membrane antigen by enzyme-linked immunosorbent assay
Authors: Jeansson S , Forsgren M , Svennerholm B
Published: January 2020

An antigen prepared by solubilization of membranes from herpes simplex virus (HSV)-infected cells with deoxycholate was evaluated by enzyme-linked immunosorbent assay. The deoxycholate-solubilized antigen, previously shown to contain all major HSV glycoproteins, was noninfectious and adsorbed easily and reproducibly to a polystyrene surface at pH 9.6. The deoxycholate-solubilized antigen provided an enzyme-linked immunosorbent assay of high sensitivity and reproducibility with complete correlation with complement fixation for the diagnosis of acute HSV infection. The correlation with neutralization and immunofluorescence for the presence or absence of anti-HSV activity was very good. Comparison with an HSV envelope preparation yielded results slightly in favor of the deoxycholate-solubilized antigen. The assay seems to be useful for demonstration of intrathecal production of antibody activity in HSV encephalitis.
Utility of egg yolk medium for cultivation of Mycoplasma pneumoniae
Authors: Sasaki T , Shintani M , Kihara K
Published: January 2020

Chicken egg yolk broth medium containing 10% (vol/vol) phosphate-buffered saline extract of egg yolk instead of horse serum showed better growth-promoting activity for Mycoplasma pneumoniae than did Chanock medium and was effective in promoting the growth of small numbers of M. pneumoniae. Moreover, the phosphate-buffered saline extract of egg yolk proved superior to horse serum in the following respects: (i) it was consistent in growth-promoting activity for M. pneumoniae among different batches; (ii) it could be preserved at 4 degrees C for at least 2 years; (iii) it is inexpensive and easy to obtain; and (iv) it contains large amounts of lipoproteins, cholesterol, and phospholipids.
Emended description of Kingella denitrificans (Snell and Lapage 1976): correction of the maltose reaction
Authors: Hollis D G , Weaver R E , Riley P S
Published: January 2020

Snell and Lapage proposed that the bacterium designated CDC group TM-1 be named Kingella denitrificans. Their description of the organism indicated that it produced acid from maltose which was in contrast with an earlier report from our laboratory that maltose was not utilized. In an attempt to explain the different findings in the two laboratories, the type strain and two additional strains of K. denitrificans were tested for acid production from maltose in phenol red broth, the rapid fermentation test, fermentation broth with Andrade's indicator, and oxidation-fermentation base. These media were tested without additional supplements and with supplements of horse serum (5% [vol/vol]) or rabbit serum (5% [vol/vol]). The results indicated that K. denitrificans does not produce acid from maltose. It was demonstrated that maltose in media containing serum is converted to glucose from which acid can be produced by K. denitrificans. The supplementation of maltose medium with horse serum by Snell and Lapage apparently had produced a false-positive maltose reaction. The description of K. denitrificans is emended to indicate that maltose is not utilized.
Correlation of enterotoxicity with biotype in Aeromonas spp
Authors: Burke V , Robinson J , Beaman J , Gracey M , Lesmana M , Rockhill R , Echeverria P , Janda J M
Published: January 2020

Enterotoxin production correlated with biotype in a study of 686 strains of Aeromonas spp. from Indonesia, Thailand, the United States, and Western Australia. Most strains were isolated from feces but nonfecal human isolates and environmental strains were also included. More than 80% of Voges-Proskauer (VP)-positive strains, classified as A. hydrophila, were enterotoxigenic in the suckling mouse assay as were 90% of VP-positive, arabinose-negative strains. An association between positive VP, arabinose fermentation, and failure to produce enterotoxins was found only with environmental strains. VP-negative strains which did not oxidize gluconate or produce gas from glucose were classified as A. punctata subsp. caviae. Only 2 of the 286 strains produced enterotoxins, and both were from Indonesian fecal samples. There were few remaining VP-negative strains, classified as A. punctata subsp. punctata and, of these, about half were enterotoxigenic. Regardless of source and species, 97% of Aeromonas spp. were correctly classified in relation to enterotoxin production with a hemolysin assay. A combination of biochemical testing and hemolysin assay should be suitable for diagnostic laboratories to identify enterotoxigenic Aeromonas spp. which, in children, are associated with diarrhea, unlike non-enterotoxigenic strains.
Identification of Staphylococcus species of bovine origin with the API Staph-Ident system
Authors: Langlois B E , Harmon R J , Akers K
Published: January 2020

The API Staph-Ident system was evaluated as a means for identifying the species of bovine strains of staphylococci routinely isolated from quarter-milk samples. The species identity of 314 of 581 (54%) isolates of staphylococci was correctly determined by this method. The API Staph-Ident system was more accurate in correctly identifying Staphylococcus aureus (93.9%) than in correctly identifying non-S. aureus species (41.8%). False identifications of Staphylococcus epidermidis and Staphylococcus hominis were the main reasons for the incorrect identifications of the non-S. aureus species.
Evaluation of an enzyme-linked immunosorbent assay for the detection of ectromelia (mousepox) antibody
Authors: Buller R M , Bhatt P N , Wallace G D
Published: January 2020

Ectromelia virus, an orthopoxvirus that can cause extensive morbidity and mortality (mousepox) in colonized mice, has been epizootically responsible for serious disruption of biomedical research since 1930. The lack of a sensitive and specific serological assay for infection with this virus became apparent during outbreaks of mousepox at the National Institutes of Health, Bethesda, Md., and other biomedical research institutions in 1979 and 1980. To fill this need, we evaluated an enzyme-linked immunosorbent assay. Sucrose gradient-purified ectromelia and vaccinia viruses were compared as antigens in tests on approximately 1,000 mouse sera from experimentally infected mice and conventional colonies of uninfected mice. A statistical analysis based on the frequency distribution of the absorbance values for 152 mouse sera (free of ectromelia antibody) gave 0.22 as a value to differentiate ectromelia-positive sera from ectromelia-negative sera. When enzyme-linked immunosorbent assay results were compared with those obtained by an indirect immunofluorescence assay, the former was found to be at least 10-fold more sensitive. With the procedures employed, including the use of purified vaccinia virions as antigen, the enzyme-linked immunosorbent assay proved to be highly sensitive and specific for detecting antibodies to ectromelia and vaccinia viruses. False-positive results were not encountered. False-negative results were observed in 3% of 108 separate tests of a known positive serum. Although data indicated that ectromelia antibody can be differentiated from vaccinia antibody with homologous and heterologous antigen, this procedure probably cannot be generally used because of unavailability of ectromelia antigens.
Interlaboratory variation of antibiograms of methicillin-resistant and methicillin-susceptible Staphylococcus aureus strains with conventional and commercial testing systems
Authors: Aldridge K E , Janney A , Sanders C V , Marier R L
Published: January 2020

Laboratory-prepared (conventional) and commercial susceptibility testing systems were compared by using a group of methicillin-resistant (MR) and methicillin-susceptible (MS) strains of Staphylococcus aureus. A group of 25 MR and 15 MS S. aureus strains were coded and tested blindly by disk diffusion, agar dilution, broth microdilution, Sensititre, Micro-Media, Sceptor, API 3600S, MicroScan, Autobac I, and MS-2 systems. All systems were incubated at 35 degrees C and read with either a manual or automated reader at the recommended times. Where applicable, systems were also read at 48 h. Among the conventional assays, the broth and agar dilution methods were comparable, both detecting 88% of the MR strains at 24 h and detecting 92 and 96%, respectively, at 48 h. The disk diffusion method was less efficient, detecting only 36 and 72% at 24 and 48 h, respectively. Detection of cephalothin resistance was low for all systems at both time periods, with agar dilution and disk diffusion being the most and least efficient, respectively. Some variability was also seen with detection of resistance to clindamycin and gentamicin. Among the MS strains, variability among the conventional systems occurred with methicillin, gentamicin, ampicillin, and penicillin. Comparison of the commercial systems with manual readers with the broth microdilution method (reference method) showed that for MR strains, the Sceptor system gave identical results at 24 and 48 h. Sensititre detected 68 and 88% of the MR strains, whereas Micro-Media was least effective detecting 12 and 80% at 24 and 48 h, respectively. None of the commercial systems detected cephalothin resistance well, with only one strain being indicated by the Sceptor and Sensititre systems at 48 h. Slight differences were also seen among the systems with clindamycin and gentamicin. With regard to the MS strains, variability among the systems was seen with methicillin, penicillin, ampicillin, clindamycin, and gentamicin. Among commercial systems with automated readers, the API system detected a greater number of MR strains than did the reference method at 24 and 48 h, 96 and 100%, respectively. The MicroScan method was comparable to the reference method detecting 80 and 88% of the MR strains at both time periods, respectively. Both Autobac I and MS-2 were much less effective in detecting MR strains, noting only 32 and 16%, respectively, at the 3- to 6-h readings. Poor detection of cephalothin resistance among MR strains was evident in all systems. Variability also occurred among the systems with clindamycin, gentamicin, and ampicillin. A single strain of the MR group was reported to be vancomycin resistant by the API system. Among the MS group, the greatest variability was seen with methicillin. Less variability occurred with penicillin, ampicillin, gentamicin, and vancomycin.
Candida ciferrii and Candida chiropterorum isolated from clinical specimens
Authors: Furman R M , Ahearn D G
Published: January 2020

Ten clinical yeast isolates submitted to the Centers for Disease Control from diverse geographic areas were identified as Candida ciferrii and Candida chiropterorum. The association of C. ciferrii with clinical specimens, particularly its repeated isolation from a case of onychomycosis, suggests that this species may be an etiological agent of superficial yeast infections.
EF-4 bacteremia in a patient with hepatic carcinoid
Authors: Dul M J , Shlaes D M , Lerner P I
Published: January 2020

An organism similar to EF-4, a member of the unclassified group of unusual gram-negative bacilli of Elizabeth O. King, was isolated from the blood of a 65-year-old female with previously diagnosed carcinoid of the liver. We believe this to be the first report of systemic infection with this organism.
Serum neutralizing antibody and lymphocyte transformation responses after influenza B virus infections
Authors: Zahradnik J M , Frank A L , Taber L H
Published: January 2020

Serum neutralizing antibody and influenza B-specific lymphocyte blast transformation responses were measured in 110 adults and children after an influenza B outbreak. Serum neutralizing antibody and lymphocyte blast transformation responses were seen in 67 to 75% of adults and children recently infected (less than 1 year), but significant lymphocyte blast transformation responses were seen in only 25% of those whose infection was remote (greater than or equal to 3 years). The frequencies of influenza B-induced lymphocyte blast transformation and serum neutralizing antibody responses were similar in the adults and children with similar infection histories.
Evaluation of API microtube GT system for detection of germ tube production by clinically significant yeasts
Authors: Philip A , Tsui A , O'Brien J E
Published: January 2020

A total of 152 fresh consecutive yeast isolates were tested for their ability to produce germ tubes by the API GT system (Analytab products, Plainview, N.Y.) and by a conventional method. The API system was found to be less sensitive than the conventional method. The costs per test by the API system and the conventional method were $0.76 and $0.39, respectively.
Evaluation of the AutoSCAN-3, a device for reading microdilution trays
Authors: DeGirolami P C , Eichelberger K A , Salfity L C , Rizzo M F
Published: January 2020

The AutoSCAN-3 (American MicroScan, Mahwah, N.J.) is an instrument capable of automated reading of commercially available microdilution trays for identification and quantitative susceptibility testing of rapidly growing bacteria. This study compared the results of visual and automated reading of microdilution trays for determination and interpretation of minimum inhibitory concentrations of 471 selected gram-negative and gram-positive clinical bacterial isolates. Visual and automated readings were performed in a double-blind fashion, and all discrepancies were examined by a referee. A quantitative comparison of minimum inhibitory concentrations was performed for 201 organisms, yielding 2,472 drug-organism combinations. After exclusion of off-scale values, complete quantitative agreement was obtained in 94% of 959 on-scale combinations, and agreement within +/- 1 well was obtained in 99.3%. Considering the minimum inhibitory concentration interpretations routinely furnished by the instrument, a qualitative comparison was performed for all 471 organisms. Complete agreement in interpretation was obtained in 97.6% of 5,843 drugs-organism combinations, with very major discrepancies accounting for only 0.1% and major discrepancies accounting for 0.2% of all combinations tested.
Simple procedure for preparation of bluetongue virus and epizootic hemorrhagic disease virus antigens for agar gel immunodiffusion
Authors: Stott J L , Osburn B I
Published: January 2020

A simplified procedure was developed for preparing soluble antigen from two related orbiviruses, bluetongue and epizootic hemorrhagic disease viruses, for agar gel immunodiffusion. The antigens gave excellent results in both micro-agar gel diffusion (agar gel precipitin) and macro-agar gel diffusion (bluetongue immunodiffusion). Minor modification in the spatial arrangement of reference antisera, commonly utilized in the agar gel immunodiffusion tests, was employed to reduce the possible development of false-positive reactions. The procedures for antigen preparation were inexpensive and did not require elaborate filtration or high-speed centrifugation. Stability of antigen preparations at 5 degrees C was excellent (in excess of 3 years for bluetongue virus and 2 years for epizootic hemorrhagic disease virus).