bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of sucrose phosphate and sorbitol on infectivity of enveloped viruses during storage
Authors: Howell C L , Miller M J
Published: January 2020

Cytomegalovirus and varicella-zoster virus recovery from sucrose phosphate (0.2 M SP) and 70% sorbitol (sorbitol) was compared after storage at -70, 4, and 20 degrees C over time. Recovery from 0.2 M SP was uniformly better. More tissue culture infective doses and infectious foci were recovered in cell monolayers inoculated with 0.2 M SP virus stocks as compared with viruses stored in 70% sorbitol. Although both viruses were isolated from diluted fresh stocks (10(-1) through 10(-4], freezing diluted virus suspensions generally resulted in diminished recovery. Similar stabilizing effects on respiratory syncytial virus and herpes simplex virus type 1 infectivities were observed when stocks were preserved in 0.2 M SP, as compared with 70% sorbitol. Overall, 0.2 M SP was better than 70% sorbitol for stabilizing cytomegalovirus, varicella-zoster virus, respiratory syncytial virus, and herpes simplex virus type 1 infectivities under the conditions tested.
Development of fluorescent-antibody reagents for demonstration of Pseudallescheria boydii in tissues
Authors: Jackson J A , Kaplan W , Kaufman L , Standard P
Published: January 2020

We prepared fluorescent-antibody reagents to detect and identify Pseudallescheria boydii in tissue. Antisera to broken mycelium and condidia (particulate antigens) and to culture filtrates (soluble antigens) of P. boydii were produced in rabbits. Antisera and globulin fractions of the antisera were labeled with fluorescein isothiocyanate and evaluated for their ability to stain P. boydii in tissues. The conjugates were first tested with cultures of 25 P. boydii isolates and 26 heterologous fungi that are morphologically similar to P. boydii in tissues. Labeled antibody to the soluble antigens reacted only weakly with cultures of P. boydii. Labeled antibody to particulate antigens brightly stained all P. boydii isolates and cross-reacted with Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus niger, Aspergillus terreus, Fusarium oxysporum, Fusarium solani, and a Scopulariopsis sp. The cross-reacting antibodies were removed by adsorption with A. fumigatus and F. oxysporum. The adsorbed conjugates stained P. boydii in Formalin-fixed tissues from experimentally infected mice and in Formalin-fixed tissues from humans and animals with natural infections. They did not stain the heterologous fungi in tissues.
Rapid detection of positive blood cultures
Authors: Hawkins B L , Peterson E M , de la Maza L M
Published: January 2020

A study of 16,108 blood cultures investigated the value of performing early smears in addition to the inspection of early subcultures after 12 h of incubation. The early smear and subculture detected 44.6% of 1,236 positive cultures; of those detected by the early subculture, 57.3% grew after 12 h of incubation.
Differentiation of Staphylococcus and Micrococcus spp. with the Taxo A bacitracin disk
Authors: Falk D , Guering S J
Published: January 2020

Taxo A bacitracin disks (BBL Microbiology Systems, Cockeysville, Md.) were evaluated as a test for differentiating staphylococci from micrococci in clinical laboratories. All staphylococci tested were resistant to the disks, with no zone of growth inhibition. Zones of growth inhibition ranging from 10.5 to 25.0 mm in diameter were observed with all micrococci except two isolates which failed to grow on the test medium. These findings were confirmed by minimal inhibitory concentrations to bacitracin. Staphylococci had minimal inhibitory concentrations significantly higher than those of micrococci, with no overlap in the ranges of values.
Polymicrobial bacteremia caused by Ewingella americana (family Enterobacteriaceae) and an unusual Pseudomonas species
Authors: Pien F D , Farmer J J , Weaver R E
Published: January 2020

Ewingella americana and a Pseudomonas species were isolated from three sets of blood cultures from a 41-year-old patient after coronary bypass surgery. This is the first well-described case of bacteremia due to E. americana. Based on data from 31 strains, a detailed description of E. americana is given.
O and H serotyping of Pseudomonas cepacia
Authors: Heidt A , Monteil H , Richard C
Published: January 2020

Procedures for the preparation, absorption, and titration of Pseudomonas cepacia O and H rabbit antisera are described. Seven O antigens (O1 to O7) for the slide agglutination test and five H antigens (H1, H3, H5, H6, and H7) for the agglutination and H immobilization tests were determined. Nearly 300 strains of P. cepacia isolated from hospitalized patients (a majority from Strasbourg hospitals) were serotyped. The use of P. cepacia serotyping as an epidemiological tool, especially in outbreak situations, was emphasized. Difficulties in obtaining monospecific H antisera are discussed.
Effect of incubation temperature on isolation of cytomegalovirus from fresh clinical specimens
Authors: Gregory W W , Menegus M A
Published: January 2020

The sensitivity of WI-38 cell monolayers for the isolation of cytomegalovirus from fresh clinical specimens was reduced by 41% when cultures were incubated at 33 rather than at 36 degrees C. The mean time to initial detection of cytomegalovirus cytopathic effects in cultures incubated at 33 degrees C was 4.3 days later than in cultures incubated at 36 degrees C (4.0 and 5.4 days later for saliva and urine cultures, respectively). Thus, incubation of cultures at 33 degrees C seriously compromises the efficiency with which cytomegalovirus can be isolated from clinical specimens.
Enhanced isolation of Campylobacter jejuni by cold enrichment in Campy-thio broth
Authors: Rubin S J , Woodard M
Published: January 2020

Isolation of Campylobacter jejuni from human feces by direct inoculation to Campy-BAP (Scott Laboratories, Inc., Fiskeville, R.I.) was compared with isolation after overnight enrichment at 4 degrees C in Campy-thio broth followed by subculture to Campy-BAP. Of 54 positive specimens, 19 were positive only after enrichment, and 5 were positive only on the direct plate. Among 36 positive patients, 10 were detected by enrichment only and 2 by direct plating only. Laboratories using Campy-BAP should include cold enrichment in Campy-thio broth for optimum recovery of C. jejuni.
Evaluation of murine cytomegalovirus antibody detection by serological techniques
Authors: Anderson C A , Murphy J C , Fox J G
Published: January 2020

Naturally acquired murine cytomegalovirus (MCMV) infection in laboratory strains of mice induces antibody levels which are generally undetectable by standard techniques; therefore, MCMV has not been included routinely in mouse viral antibody screening programs. The relative sensitivity of three assay systems, the nuclear anticomplement immunofluorescence (NACIF), the enzyme-linked immunosorbent assay (ELISA), and the complement fixation (CF) test, was evaluated for the detection of MCMV antibodies. Sera were harvested from CD1 male mice (33 days old) infected intraperitoneally with salivary gland-passaged MCMV (Smith strain). The sera were assayed separately at weeks 1 through 8, and at week 11, 16, and 25 post-inoculation; a total of 167 mice in 11 groups were tested. The animals tested at 1 week post-inoculation had low levels of antibodies to MCMV as measured by the NACIF test (1:10), whereas only 25% were positive by ELISA, and none was positive by CF until 5 weeks post-inoculation. A higher titer of MCMV antibodies was measured by CF (1:640) than by NACIF (1:40) at 6 months post-inoculation; yet, a titer of 1:3,200 was detected by ELISA from the same serum. The ELISA technique was more sensitive for detecting persistent infection with MCMV, and NACIF was more useful for detecting acute MCMV infection. Since MCMV can have significant long-term effects on the immune system, it is recommended that testing for antibodies to MCMV be included in mouse viral antibody screening protocols.
Tetrazolium reduction as an aid for streptococcal growth detection with agar dilution susceptibility testing
Authors: Coudron P E , Ford J M , Dalton H P
Published: January 2020

A dye reduction method for determining a definitive endpoint with agar dilution susceptibility testing has been developed. Bacterial growth was determined by applying to the inoculum spot a dye solution containing 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride and phenazine methosulfate. Viable colonies reduced the tetrazolium salt to a visible red color within 3 to 5 min. The minimum inhibitory concentrations of six antimicrobial agents tested against 167 clinical streptococcal isolates were recorded before and after the addition of the tetrazolium-phenazine methosulfate solution. A total of 252 discrepancies (25%) were observed, and of these, 30 (12%) differed by more than one tested antibiotic concentration. Endpoint reproducibility of the dye procedure was assessed by four technologists in a double-blind study. A 2.7-fold reduction in disagreement was observed when the dye was used. Use of the tetrazolium-phenazine methosulfate solution involves little deviation from standard antimicrobial susceptibility test procedures and yields more accurate, as well as reproducible, susceptibility results.
Bacteriology of dental abscesses of endodontic origin
Authors: Williams B L , McCann G F , Schoenknecht F D
Published: January 2020

Aspirates have been cultured from 10 dental abscesses of endodontic origin, all of which had penetrated beyond the bony alveolus to produce fluctuant swelling. Sampling was by syringe aspiration. Strict anaerobic techniques, including the use of an anaerobic chamber, were used for serial dilution and plating. Randomly selected colonies (100) from each culture were purified, characterized, and identified. Seventy percent of the bacterial isolates were either strict anaerobes or microaerophilic. One abscess yielded a pure culture of a viridans streptococcus, Streptococcus milleri. Streptococcus intermedius dominated the flora in a second abscess. The common oral streptococcus, Streptococcus sanguis, constituted only 2% of the isolates from one additional infection. Fusobacterium nucleatum, Bacteroides melaninogenicus, other Bacteroides including B. oralis and B. ruminicola, anaerobic diphtheroids, Peptostreptococcus micros, and Staphylococcus epidermis were other predominant isolates.
Characterization of coagulase-positive Staphylococcus intermedius and Staphylococcus aureus isolated from veterinary clinical specimens
Authors: Raus J , Love D N
Published: January 2020

Staphylococci were the most frequent isolates from clinical specimens submitted from a large referral and teaching veterinary hospital. In this study a total of 160 isolates were examined by a wide range of biochemical tests and modifications of basic procedures. An attempt was made to test the validity of these procedures for use in characterization of clinical isolates of coagulase-positive staphylococci. Of the isolates examined, some 27 were Staphylococcus aureus, 115 were Staphylococcus intermedius, and the rest were coagulase-negative staphylococci and were not characterized further. The most useful discriminatory tests were acid production from maltose incubated overnight on maltose purple agar (W. E. Kloos and K. H. Schleifer, J. Clin. Microbiol., 1:82-88, 1975), acetoin production detected by the Barritt method, and detection of hyaluronidase activity. These gave accurate and fast results. Supplemented with the tellurite reduction test and the direct staphylocoagulase assay using Chromozym TH (Engels et al.; J. Clin. Microbiol. 14:496-500, 1981), these tests should eliminate the possibility of false identifications of these two species.
Comparison of methods to detect Escherichia coli heat-labile enterotoxin in stool and cell-free culture supernatants
Authors: Morgan D R , DuPont H L , Wood L V , Ericsson C D
Published: January 2020

We compared the standard Y-1 adrenal cell (YAC) assay for heat-labile enterotoxin (LT) with newer rapid and economical immunological methods of detection. Stool samples were collected from 164 acutely ill American students in Guadalajara, Mexico. Supernatants were prepared from each stool. Stools were cultured for Escherichia coli by standard techniques. Individual E. coli-like colonies were examined for LT production by the Biken assay. Culture supernatants and stool supernatants were assayed for the presence of LT by the YAC assay, counterimmunoelectrophoresis, and enzyme-linked immunosorbent assay (ELISA). Standard YAC assays of culture supernatants revealed that 40 of the 164 specimens (24%) were LT positive. Counterimmunoelectrophoresis detected 60% and ELISA detected 65% of the 40 known positives when culture supernatants were used. The Biken assay detected 35% of the 40 known positives. With stool supernatants, the YAC assay detected only 18% of the known positives, counterimmunoelectrophoresis detected 60%, and ELISA detected 90%. In addition, ELISA detected 13 LT-positive stool supernatants not detected by the YAC assay of culture supernatants. The ELISA in which stool supernatants are used may be a useful method to detect LT.
Single radial complement fixation test for assaying antibody to influenza virus type-specific antigens
Authors: Yamane N , Yuki M , Nakamura Y
Published: January 2020

An immunodiffusion technique in agarose is described for assay of complement-fixing antibodies against the type-specific soluble antigen of influenza virus. Under the test conditions, positive human serum produced a definite unlysed zone around the well, and the annulus area showed a high correlation with the antibody level in a conventional complement fixation test with log2 serum titer. This paper also describes the use of this method as a diagnostic procedure for the assay of antibodies against soluble antigens of influenza A and B viruses in paired human sera collected from persons infected with the virus or who received ether-split vaccine. This method appears to more sensitive and gives more consistent results for serodiagnosis of infection cases than do the hemagglutination inhibition, neuraminidase inhibition, and complement fixation tests. Our results suggest that the single radial complement fixation test can provide a simple and reliable method for serodiagnosis of influenza virus infection.
Analysis of Candida albicans phenotypes from different geographical and anatomical sources
Authors: Odds F C , Abbott A B , Stiller R L , Scholer H J , Polak A , Stevens D A
Published: January 2020

Strain phenotypes of 330 Candida albicans isolates from five areas in the United States were determined on the basis of nine biochemical tests. Statistical analysis of the distribution of phenotypes revealed no significant differences among types from different anatomical sources. However, there were some differences among the phenotypes of strains from the different geographical areas, and there were substantial differences in biochemical phenotypes associated with strains susceptible and resistant to 5-fluorocytosine and between strains of serotypes A and B. Geographical differences in phenotypes of C. albicans were also noted between the 330 U.S. isolates and 247 isolates from Britain. Cluster analysis of the U.S. strains alone and of all of the U.S. and U.K. strains showed that C. albicans phenotypes can be grouped into fewer than 20 clusters with common biochemical properties.
Use of a fluorometric immunoassay to determine antibody response to Pasteurella haemolytica in vaccinated and nonvaccinated feedlot cattle
Authors: Confer A W , Wright J C , Cummins J M , Panciera R J , Corstvet R E
Published: January 2020

A retrospective study of the antibody response to Pasteurella haemolytica was conducted by using sera from 368 feedlot cattle divided among five experiments. In three experiments, live vaccines or a bacterin were administered to some of the cattle and others were left as nonvaccinated controls. In two experiments, cattle were not vaccinated. Clinical signs of disease with subsequent recovery developed in 48.0% of the cattle, and 10.3% of the cattle died. Vaccination had no apparent effect on morbidity or mortality. At the time of purchase, 78% of the cattle had low antibody titers (less than 25) as measured by a quantitative fluorometric immunoassay. In most groups of cattle (both vaccinated and nonvaccinated), there was a significant rise in mean antibody titers between the time of purchase and days 28 to 32 in the feedlot. The antibody titers at the time of shipment and health status of cattle. The antibody ratios were significantly greater for cattle that became sick and then recovered compared with those of cattle that remained healthy. Although significance could not be established, antibody titers at the time of shipment were higher for cattle that remained healthy compared with cattle that became sick and then recovered.
Evaluation of four gentamicin and tobramycin assay procedures for clinical laboratories
Authors: Witebsky F G , Sliva C A , Selepak S T , Ruddel M E , MacLowry J D , Johnson E E , Elin R J
Published: January 2020

Accuracy, precision, and clinical laboratory utility of the TDX (Abbott Laboratories), Auto-ICS (Beckman Instruments, Inc.), COBAS-Bio (Roche Analytical Instruments, Inc.) with reagent kits (Syva), and EMIT (Syva) for gentamicin and tobramycin serum assay were assessed. TDX, COBAS-Bio, and EMIT analytical systems showed a proportional bias of less than 10% for recovery studies and a coefficient of variation less than 5% for within-run precision. The results of the recovery studies with the Auto-ICS showed a proportional bias of 25% with gentamicin and 16% with tobramycin. The within-run precision expressed as the coefficient of variation for the Auto-ICS was 6.7% for gentamicin and 8.6% for tobramycin. In comparisons involving gentamicin- and tobramycin-containing patient samples, the results with the TDX analytical system showed the best agreement with the COBAS-Bio. For the determination of these two antibiotics, the TDX analytical system provided the best overall accuracy and precision.
Serological investigation of an outbreak of simian varicella in Erythrocebus patas monkeys
Authors: Schmidt N J , Arvin A M , Martin D P , Gard E A
Published: January 2020

An epizootic of simian varicella occurring in a colony of Erythrocebus patas monkeys was studied serologically by using radioimmunoassay and neutralization tests against (i) a virus strain isolated from an animal that died during the epizootic, (ii) a simian varicella virus strain from an earlier outbreak of simian varicella-like disease at another facility, and (iii) human varicella-zoster virus. Serological tests detected more cases of infection among the animals exposed to virus during the epizootic than were evidenced by clinical findings; only 6 of the 26 animals with seroconversion developed a rash. Good correlation was seen between antibody responses demonstrated by radioimmunoassay and by the neutralization tests. Specificity of the radioimmunoassay was evidenced by the complete agreement with neutralization results for 17 animals which failed to show an antibody response over the course of the outbreak and were assumed not to have been infected. Thus radioimmunoassay is a reliable, rapid, and relatively economical method which could be used for serological screening of primates entering experimental colonies to identify those which might be potential sources of outbreaks through activation of latent simian varicella virus infection. Close correlation was seen between antibody responses to the virus strain from the current outbreak and the one from another epizootic, indicating that the two outbreaks were caused by antigenically similar viruses. Animals showing neutralizing antibody responses to the simian varicella viruses also showed responses to human varicella-zoster virus, which further substantiates the close antigenic relationship between human and simian varicella viruses.
Cellular fatty acid composition and ubiquinone content of Legionella feeleii sp. nov
Authors: Moss C W , Bibb W F , Karr D E , Guerrant G O , Lambert M A
Published: January 2020

The cellular fatty acid composition of Legionella feeleii was determined by capillary gas-liquid chromatography, and the ubiquinone content was determined by reverse-phase high-pressure liquid chromatography. As in other Legionella species, this new species is characterized by relatively large amounts of branched-chain fatty acids and by major amounts of ubiquinones with more than 10 isoprene units in the side chain.
Increased sensitivity and reduced specificity of hemagglutination inhibition tests with ether-treated influenza B/Singapore/222/79
Authors: Kendal A P , Cate T R
Published: January 2020

Hemagglutination inhibition (HI) tests against whole virus (WV) influenza B/Singapore/222/79 antigen detected prevaccination serum antibody in only 15 (20%) of 50 predominantly elderly volunteers and fourfold or greater titer rises in only three (6%) after they received 1981-1982 trivalent influenza vaccine containing antigens of this virus. HI titers against ether-treated (ET) B/Singapore/222/79 were about eightfold higher than those against WV antigen and were comparable to microneutralization titers against this virus. The ET HI detected prevaccination antibody in 84%, a postvaccination titer rise in 32%, and a final titer of 80 or higher in 66%. Among 51 additional persons with known or presumed influenza B virus infections early in 1982, ET B/Singapore/222/79 was also more sensitive than WV for serodiagnosis (69 versus 49%), but eight persons with both WV and ET B/Singapore/222/79 HI responses also had an HI titer rise to WV A/Brazil/11/78 (H1N1) antigen. Conversely, among 14 college students with febrile, culture-proven influenza A (H1N1) infections early in 1982, 6 (43%) developed HI titer rises to ET B/Singapore/222/79 with no other serological evidence of influenza B virus infection. Moreover, young adult volunteers with mild experimental influenza A (H1N1) infections also exhibited a 17% (3 of 18) incidence of ET B/Singapore/222/79 HI titer rises, versus none in matched, uninfected volunteers. These data indicate that ET B/Singapore/222/79 virus has increased sensitivity but reduced specificity compared to WV as an HI antigen and that caution is needed in interpretation of a single HI test for serodiagnosis, whether with WV or ET antigen.
Changes in serotypes of enterotoxigenic Escherichia coli in Dhaka over time: usefulness of polyvalent antisera
Authors: Stoll B J , Rowe B , Glass R I , Gross R J , Huq I
Published: January 2020

The finding that enterotoxigenic (ET) Escherichia coli strains from many geographic areas belong to a limited number of serogroups led investigators to hope that polyvalent antisera could be used to screen for ET E. coli in areas of the world where more complicated tests of toxigenicity are not available. We compared the serotypes of 207 ET E. coli strains obtained from patients attending the Dhaka Hospital of the International Centre for Diarrhoeal Disease Research, Bangladesh, in 1980 with results obtained from similar surveys conducted in 1976 and 1978. During that time the distribution of serogroups changed significantly so that only 46% of our strains had O serogroups included in the polyvalent antisera capable of detecting 66% of ET E. coli strains in 1978. O167, a serogroup which was not included previously, was the third most common serogroup in our study. These findings suggest that polyvalent antisera used to screen for ET E. coli need to be reassessed over time as well as in different geographic areas and may not be as useful for field diagnosis as was originally hoped.
Pseudobacteremia due to contaminated alcohol swabs
Authors: Berger S A
Published: January 2020

Fifteen isolates of Bacillus species were recovered during a 19-day period after the introduction of an automated radiometric blood culture system. The outbreak was traced to alcohol-resistant spores present in the cotton used to disinfect blood culture bottles. The role of Bacillus species as a pathogen and a laboratory contaminant is discussed.
Computer-assisted determination of antibiotic susceptibility in photometer-read microtiter plates
Authors: Turner A , Hawkey P M , Pedler S J
Published: January 2020

A method for the computer-assisted determination of microdilution minimal inhibitory concentrations by using a Dynatech MR580 through-the-plate reading photometer is presented. The method was evaluated by comparison with manual determination of the minimal inhibitory concentrations of 12 antibiotics for 115 bacterial isolates. The two methods agreed within one dilution in 98.3% of the cases.
Detection and partial characterization of circulating immune complexes in hydatid disease
Authors: D'Amelio R , Pontesilli O , Palmisano L , Pezzella M , Vullo V , Delia S , De Rose F , Sorice F , Aiuti F
Published: January 2020

Thirty sera from eight patients with disseminated or localized hydatid disease have been examined for the presence of circulating immune complexes (CICs) by the conglutinin-binding assay and for immunoglobulin levels. The highest levels of CICs were of the immunoglobulin A (IgA) class, with lower values of IgG-CIC and IgM-CIC; these results did not correlate, except for IgG, with the free immunoglobulin levels. Efforts to identify parasitic antigen(s) involved in the CIC formation with different methods have been unsuccessful. In the follow-up of each patient, CIC appeared to be better correlated to clinical conditions than to hemagglutination titers. We have concluded that the presence of CIC in hydatid disease is probably an expression of B-cell polyclonal activation and that these complexes are valuable in the clinical monitoring of the disease.
Clinical laboratory comparison of lysis-centrifugation and BACTEC radiometric blood culture techniques
Authors: McLaughlin J C , Hamilton P , Scholes J V , Bartlett R C
Published: January 2020

The lysis-centrifugation technique (ISOLATOR; E. I. du Pont de Nemours & Co., Wilmington, Del.) and the radiometric blood culture technique (BACTEC; Johnston Laboratories, Inc., Cockeysville, Md.) were compared on 1,000 blood cultures. A total of 16 ml of blood was distributed: 8 ml into an ISOLATOR 7.5 microbial tube and 4 ml each into BACTEC 7C and 8B bottles. The concentrate from the ISOLATOR tubes was inoculated under a laminar-flow hood onto two sheep blood agar plates (one incubated in CO2 and one incubated anaerobically), one chocolate agar plate, and one brain heart infusion agar plate. Of 91 blood specimens obtained that yielded clinically significant organisms, 52 were positive by both systems, 27 were positive by the ISOLATOR system only, and 12 were positive by the BACTEC system only. From the positive blood specimens, 97 clinically significant organisms were isolated: 57 by both systems, 27 by the ISOLATOR system only, and 13 by the BACTEC system only. Of the 57 organisms detected by both systems, 28 were detected simultaneously, 13 were detected earlier by the ISOLATOR system, and 16 were detected earlier by the BACTEC system. Isolated colonies were obtained earlier by the ISOLATOR system in 40 cases and by the BACTEC system in 5 cases. Organisms determined to be contaminants by thorough chart review were isolated from 138 ISOLATOR tubes. In 98 instances, these were represented by one colony of Staphylococcus epidermidis, alpha-hemolytic streptococci, or diphtheroids. The ability to determine CFU per milliliter with the ISOLATOR system did not help differentiate clinically significant organisms from contaminants.
Inactivation of the polyanionic detergent sodium polyanetholsulfonate by hemoglobin
Authors: Edberg S C , Edberg M K
Published: January 2020

Sodium polyanetholsulfonate (SPS) has been added to blood culture media for many years. Its incorporation results in a higher yield of positive blood cultures due to its inactivation of antimicrobial cationic compounds. The most active of these cations include complement components, aminoglycoside-aminocyclitol antibiotics, and receptors on polymorphonuclear leukocytes. There have been reports from studies conducted outside patient blood culture bottles that SPS itself may possess antibacterial activity against some isolates of Neisseria meningitidis, Neisseria gonorrhoeae, and Peptostreptococcus anaerobius. Conversely, in patient clinical trials there has been no significant difference in pathogen isolation rates in the presence or absence of SPS. In an attempt to explain this in vitro/in vivo disparity, a search was undertaken to elucidate which variable constituent in blood, heretofore not studied quantitatively, might have a major effect on modulating the activity of SPS. It was found that hemoglobin combined stoichiometrically with SPS with a Kd of approximately 10(-7) mol/liter. Optimum SPS inactivation occurred at an SPS/hemoglobin ratio of 1:6 (wt/wt). SPS-sensitive isolates of N. gonorrhoeae and N. meningitidis were protected by the addition of hemoglobin from the antimicrobial effects of this polyanion in time-kill studies. This protection was directly related to the amount of SPS combined in solution. Therefore, the amount of free hemoglobin in solution must be measured when studying the antimicrobial activity of polyanions or when evaluating the effect of different polyanions on the recovery rates of pathogens in patient blood culture clinical trials.
Quality control parameters for susceptibility tests with 30-micrograms netilmicin disks
Authors: Barry A L , Gavan T L , Jones R N
Published: January 2020

A nine-laboratory cooperative study was performed to evaluate quality control parameters for susceptibility tests with 30-micrograms netilmicin disks. The applicability of currently recommended zone-size limits was confirmed. However, alternative statistical methods suggested that tighter control limits might be more appropriate but would require better standardization of reagents, especially Mueller-Hinton agars.
Comparison of polyvinyl alcohol- and formalin-preserved fecal specimens in the formalin-ether sedimentation technique for parasitological examination
Authors: Carroll M J , Cook J , Turner J A
Published: January 2020

A total of 965 paired fecal specimens preserved in polyvinyl alcohol fixative and Formalin were processed by the Formalin-ether sedimentation technique. The effectiveness of the concentration procedures with material from each preservative was determined by comparing both diagnostic efficiency (percent identified) and quantitative egg and semiquantitative cyst counts. Of the 319 infections, 69.5% were detected in concentrates from both preservatives, 6.9% from polyvinyl alcohol only, and 23.5% from Formalin only. The egg and cyst counts were consistently higher from the specimens preserved in Formalin for most of the species of organisms recovered. These findings strongly support the use of Formalin-fixed specimens for the Formalin-ether concentration technique.
Successful use of broth microdilution in susceptibility tests for methicillin-resistant (heteroresistant) staphylococci
Authors: Thornsberry C , McDougal L K
Published: January 2020

We studied the broth microdilution antimicrobial susceptibility testing procedure to see whether it could be made reliable for determining resistance of staphylococci to methicillin, oxacillin, nafcillin, and cephalothin. With 45 selected strains of Staphylococcus aureus and 12 selected strains of Staphylococcus epidermidis we found that the addition of 2% NaCl to cation-supplemented Mueller-Hinton broth permitted us to discriminate reliably between resistant and susceptible organisms. A screening test in which resistant staphylococci grew on agar containing 4% NaCl and methicillin (10 micrograms/ml), oxacillin (6 micrograms/ml), or nafcillin (6 micrograms/ml) incubated at 35 degrees C for 24 h (additional 24 h if no growth) was also reliable. In vitro cephalothin resistance occurred in heteroresistant S. aureus but usually did not occur in heteroresistant S. epidermidis.
Differentiation of staphylococci on the basis of nuclease properties
Authors: Gudding R
Published: January 2020

The quantity, thermostability, and serological pattern of nucleases produced by different staphylococci were studied. Staphylococcal strains were isolated from nine different species of animals or from humans. Staphylococcus aureus, Staphylococcus intermedius, and Staphylococcus hyicus subsp. hyicus were vigorous producers of nuclease, whereas the coagulase-negative staphylococci, except S. hyicus subsp. hyicus, produced significantly less nuclease. The nucleases of all strains were found to be thermostable. S. aureus, S. intermedius, and S. hyicus subsp. hyicus could be distinguished from each other and from coagulase-negative staphylococci on the basis of inhibition of nuclease activity by specific antibodies.
Detection of bacterial antigens in body fluids with the Wellcogen Haemophilus influenzae b, Streptococcus pneumoniae, and Neisseria meningitidis (ACYW135) latex agglutination tests
Authors: Ingram D L , Pearson A W , Occhiuti A R
Published: January 2020

The Wellcogen Haemophilus influenzae b, Streptococcus pneumoniae, and Neisseria meningitidis (ACYW135) latex agglutination tests (Wellcome Diagnostics, Dartford, England) were evaluated as methods to detect bacterial antigens in cerebrospinal fluid (CSF), urine, and serum from patients with meningitis or sepsis. Antigen was detected in 92% of CSFs from H. influenzae b, 100% of CSFs from N. meningitidis groups A and Y, 36% of CSFs from N. meningitidis group C, and 69% of CSFs from pneumococcal meningitidis patients. Serum samples presented a problem, with a few false-positive or possible cross-reactions. The Wellcogen latex agglutination tests were more sensitive than the Bactogen (H. influenzae type b) latex agglutination test and the Phadebact (S. pneumoniae) coagglutination test.
Five years of experience with a national external quality control program for the culture and identification of Neisseria gonorrhoeae
Authors: Griffin C W , Mehaffey M A , Cook E C
Published: January 2020

In response to a need for monitoring the proficiency of public health laboratories in isolating and identifying Neisseria gonorrhoeae, a national external quality control program was developed. Essentially, three types of freeze-dried samples, representing different levels of challenge for identification, were sent to laboratories for testing. The quality of the samples was confirmed by external reference laboratories, and stability of the samples was confirmed by thermal degradation tests before the samples were sent to laboratories enrolled in the program. By analyzing laboratory results, we identified common errors and chronic problems in testing samples. As a group, laboratories testing small numbers of actual patient specimens did not perform as well in the program as did laboratories testing large numbers of specimens; however, the performance of laboratories testing small numbers of specimens improved over time. Overall, laboratories experienced the most difficulty with samples containing N. gonorrhoeae mixed with other microbial species. Laboratories that performed confirmatory tests committed fewer errors than did laboratories that performed presumptive tests only, but the failure to use pure cultures of gonococci for inoculation of cystine tryptic digest agar appeared to be a chronic problem in confirmatory carbohydrate testing. A review of the use of different plating media and confirmatory tests showed that the use of certain media and tests changed over time.
Evidence for thiocyanate-sensitive peroxidase activity in human saliva
Authors: Cowman R A , Baron S S , Obenauf S D , Byrnes J J
Published: January 2020

A procedure was developed for determining the relative levels of lactoperoxidase, leukocyte myeloperoxidase, and thiocyanate-sensitive peroxidase in human saliva. With this procedure, most of the peroxidase activity in whole saliva from normal (those without cancer) subjects was found to be associated with lactoperoxidase and thiocyanate-sensitive peroxidase, with only a minor contribution from leukocyte myeloperoxidase. In contrast, thiocyanate-sensitive peroxidase and leukocyte myeloperoxidase were the major peroxidase activities present in the residual salivary secretion obtainable from two xerostomic patients examined, and these enzymes were present at concentrations much higher than those normally occurring in human saliva. The occurrence of thiocyanate-sensitive peroxidase in saliva has not been previously reported and may represent either an additional peroxidase activity of saliva or a form of lactoperoxidase which is particularly sensitive to inhibition by thiocyanate.
Monoclonal antibodies specific for O-antigenic polysaccharides of Shigella flexneri: clones binding to II, II:3,4, and 7,8 epitopes
Authors: Carlin N I , Lindberg A A
Published: January 2020

Hybrid cells producing monoclonal antibodies against the O-antigens of Shigella flexneri were obtained by polyethylene glycol-mediated fusion of myeloma cells and lymphocytes from BALB/c mice immunized with whole heat-killed S. flexneri bacteria of serotypes 2a and 2b. Clones were selected for their binding specificity to structurally defined S. flexneri lipopolysaccharides (LPS). The following three groups were identified as recognizing three different epitopes: monoclonal antibodies binding to (i) S. flexneri LPS with the II:3,4 antigens, (ii) S. flexneri LPS with the II:3,4 antigens and the II:7,8 antigens, and (iii) S. flexneri LPS with the 7,8 group antigen only. Of cloned and characterized antibodies, more than 90% had either the mu or gamma 3 heavy chain and 98% had the kappa light chain. The exquisite specificity of each monoclonal antibody preparation was in complete contrast to the polyclonal specificities seen in sera from immunized rabbits. Even absorbed rabbit S. flexneri typing sera contained antibodies reacting with several different LPS, i.e., they were not type antigen specific. Ascites from immunoglobulin G monoclonal antibody preparations representing the three different specificities were used for sensitizing Staphylococcus aureus Cowan 1 bacteria and were used in coagglutination. In testing 211 clinical isolates of all different serotypes of S. flexneri, the reagents were shown to be sensitive and specific in correctly identifying all S. flexneri II and 7,8 antigen-containing strains with no false positives. Two isolated immunoglobulin M antibody clones specific for the II:3,4 and 7,8 antigens were used as successfully for identification by direct slide agglutination. These results suggest that the monoclonal reagents are superior to conventional typing antisera.
Use of avidin-biotinylated horseradish peroxidase complex for visualization of spirochetes
Authors: Jennings B R , Mincer H , Turner J , Baselski V , Kelly R T
Published: January 2020

The use of avidin-biotinylated peroxidase as a simple technique for light microscopic visualization of spirochetes is described. The three major genera of spirochetes--Treponema, Borrelia, and Leptospira--were stained with the avidin complex.
Ammonium bicarbonate as a replacement for carbon dioxide in Transgrow bottles for primary isolation of Neisseria gonorrhoeae
Authors: Potter L D , Lewis J S , Wentworth B B , Larsen E H
Published: January 2020

Transgrow bottles with medium containing ammonium bicarbonate and Transgrow bottles gassed with 10% carbon dioxide performed equally well in detecting Neisseria gonorrhoeae in 434 clinical specimens. It appears that incorporation of ammonium bicarbonate into the medium increased the efficiency of the manufacturing process while maintaining the effectiveness of the medium.
Isolation of Branhamella catarrhalis from sputum and tracheal aspirate
Authors: Aitken J M , Thornley P E
Published: January 2020

Branhamella catarrhalis was suggested by the presence of gram-negative intracellular diplococci and confirmed by quantitative culture of the expectorated sputa of 11 patients with clinical evidence of lower respiratory tract infection. In quantitative culture, more than 20 colonies of B. catarrhalis were seen in each of the liquefied expectorated sputa at a dilution of 10(-7). Transtracheal aspirations were then performed on these 11 patients, and B. catarrhalis was isolated from the lower respiratory tract secretions of 10 of the patients. Of the 10 isolates, 5 produced beta-lactamase. None of the isolates grew on modified Thayer-Martin medium. The presence of gram-negative intracellular diplococci and the growth of B. catarrhalis on quantitative culture of expectorated sputum reliably indicates the presence of B. catarrhalis in the lower respiratory tract.
Gono Gen coagglutination test for confirmation of Neisseria gonorrhoeae
Authors: Lawton W D , Battaglioli G J
Published: January 2020

The Gono Gen (Micro-Media Systems, Inc., Potomac, Md.) coagglutination test was compared with the sugar utilization test and with a direct fluorescent antibody test for confirmation of Neisseria gonorrhoeae. Of 110 gonococcal clinical isolates, 109 were positive by the Gono Gen test. Of 57 nongonococcal gram-negative diplococci, all were negative by the Gono Gen test. We conclude that the Gono Gen test is sensitive and highly specific and provides a rapid method for the confirmation of N. gonorrhoeae.
Rapid and economical identification and antimicrobial susceptibility test methodology for urinary tract pathogens
Authors: Edberg S C , Trepeta R W
Published: January 2020

To decrease the time and cost of processing urine cultures, we devised a critical pathway to identify and perform antibiotic susceptibility tests on commonly isolated microbial pathogens within 6 h of growth detection. The strategy was based on eliminating expensive kits and automated procedures when not required. A pathway utilizing a statistical matrix and three rapid biochemical tests required to identify the most common pathogen, Escherichia coli, was developed. This species, which represented 82% of urinary isolates, was identified in 1 h for less than 10% the cost of a commercial kit. The specificity of the 1-h E. coli identification battery was greater than or equal to 99.9% with a sensitivity of 93%. In addition, this critical pathway, adapting published methods, permitted the identification of other enteric pathogens, the group D streptococci, and Pseudomonas aeruginosa within 4 to 6 h. Furthermore, it accounted for other microbes that required longer periods of incubation. The pathway also included a rapid disk diffusion sensitivity test. Utilizing the critical pathway strategy, 76% (E. coli frequency of 0.82 X E. coli sensitivity of 0.93) of all urinary pathogens were identified within 1 h, and 98% were identified within 4 h with an antibiotic sensitivity test available within 6 h after the observation of growth. Costs were reduced from 2.5 to 5.0 times. This methodology is applicable to other specimen types.
Comparison of five methods of cytomegalovirus antibody screening of blood donors
Authors: Phipps P H , Grégoire L , Rossier E , Perry E
Published: January 2020

A group of 120 sera from blood donors was screened by complement fixation and commercially available immunofluorescence, solid-phase fluorescence immunoassay, enzyme-linked immunosorbent assay, and indirect hemagglutination tests. Twenty-four of the sera were positive by three or more of the five tests and judged to be true positives; 89 were negative by three or more of the tests and considered to be true negatives. The tests were ranked for accuracy, sensitivity, specificity, false-positive rate, and false-negative rate. The indirect hemagglutination test scored best, followed by enzyme-linked immunosorbent assay, solid-phase fluorescence immunoassay, complement fixation, and immunofluorescence, in that order. When the tests were ranked on the basis of technical demands, turnaround time, requirement for special equipment, and subjectivity in reading, the indirect hemagglutination test again scored best, followed by solid-phase fluorescence immunoassay, enzyme-linked immunosorbent assay, immunofluorescence, and complement fixation in that order. Our findings suggest that the indirect hemagglutination test is the most reliable and effective commercially available test for the identification of those donors who are very unlikely to transmit cytomegalovirus to recipients.
Species identification and antibiotic susceptibilities of coagulase-negative staphylococci isolated from clinical specimens
Authors: Gill V J , Selepak S T , Williams E C
Published: January 2020

Identification of potentially significant coagulase-negative staphylococci isolated from clinical specimens was performed along with antibiotic susceptibility determinations, S. epidermidis accounted for 75% of these isolates, with S. haemolyticus and S. hominis being the second and third most frequently encountered species, respectively. Although there were many instances of single blood culture isolations of questionable significance, all three species were also found in multiple blood cultures from individual patients, indicating the ability to cause significant bacteremia. The most common source for most species was blood, except for S. saprophyticus and S. simulans, which were found more frequently in urine. Of urinary tract isolates, however, S. epidermidis was more common than S. saprophyticus. Antibiotic susceptibility profiles demonstrated that S. haemolyticus and S. epidermidis were frequently multiply antibiotic resistant. S. haemolyticus had a higher percentage of isolates that were oxacillin, cephalothin, aminoglycoside, erythromycin, and clindamycin resistant than did S. epidermidis. We found that species identification could be of benefit for both epidemiological as well as patient care purposes, and that this additional information is readily available, using convenient and rapid new methods.
Identification of a carrier by using Vi enzyme-linked immunosorbent assay serology in an outbreak of typhoid fever on an Indian reservation
Authors: Engleberg N C , Barrett T J , Fisher H , Porter B , Hurtado E , Hughes J M
Published: January 2020

In May 1981 an outbreak of typhoid fever occurred in a small village on a southwestern United States Indian reservation. Five of the six culture-proven cases, but only 2 of 15 community, age-matched controls, had eaten food prepared for a party held in the village on 20 April (chi-square = 4.3; P less than 0.05). Food histories obtained from 16 persons who ate food at the party suggested that chicken with chili (P = 0.03) and potato salad (P = 0.09) were possible vehicles. Eleven adults who attended the party, 5 of whom helped prepare an implicated food, were studied with one or more stool cultures and serum for Vi antibody by using enzyme-linked immunosorbent assay (ELISA) and hemagglutination techniques. All initial stool cultures were negative for Salmonella typhi; however, one subject, a 70-year-old female foodhandler, had a Vi antibody titer of 1:320 by ELISA. Subsequent cultures from this subject were positive for S. typhi. ELISA for Vi antibody directed the investigators to a single individual as the most probable carrier source and obviated the need for multiple fecal cultures from the other potential carriers identified by the epidemiological investigation.