bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct identification of Staphylococcus aureus in blood culture fluid with a commercial latex agglutination test
Authors: Doern G V , Robbie L I
Published: January 2020

A commercial latex agglutination slide test (SeroSTAT Staph, Scott Laboratories, Inc., Fiskeville, R.I.) accurately identified Staphylococcus aureus when applied directly to blood culture fluid containing staphylococci. This latex agglutination test exhibited 100% accuracy when 30 seeded aerobic and anaerobic radiometric blood cultures (15 strains of S. aureus, 15 strains of other staphylococcal species) were tested blindly. In 36 actual clinical specimens yielding 16 isolates of S. aureus and 20 isolates of Staphylococcus epidermidis, 94.4% accuracy was achieved. The latex agglutination test provided positive test results before objective criteria of blood culture positivity such as radiometric growth indices and Gram stains became positive.
Group G streptococcal epizootic in a closed cat colony
Authors: Tillman P C , Dodson N D , Indiveri M
Published: January 2020

An epizootic of beta-hemolytic Lancefield group G streptococcal infections occurred in a specific-pathogen-free colony of laboratory cats. A total of 19 out of 68 animals in a single building were affected over a 10-day period. Clinical signs included fever, depression, lymphadenopathy, pharyngitis, and submandibular edema. The organism was recovered from the pharynx in two of five clinically normal cats from the affected building. Cultures from 12 animals in the same colony but housed in unaffected buildings were negative. Two doses of long-acting penicillin G 72 h apart stopped the outbreak and resulted in negative cultures for previously affected animals. Three months later, two new cases occurred in the same building. The disease was finally eradicated from the colony by depopulating the affected building.
Comparison of media in the Anaerobe-Tek and Presumpto plate systems and evaluation of the Anaerobe-Tek system for identification of commonly encountered anaerobes
Authors: Lombard G L , Whaley D N , Dowell V R
Published: January 2020

Using a variety of sporeforming and nonsporeforming anaerobic bacteria, we compared 10 differential agar media of the Anaerobe-Tek (A/T) system recently marketed by Flow Laboratories, Inc. (McLean, Va.) with 10 comparable media in Presumpto quadrant plates (Presumpto 1, 2, and 3) developed by the Centers for Disease Control Anaerobic Bacteria Branch. The A/T identification system was evaluated by comparing the species identity of anaerobes determined as recommended by the manufacturer's instruction manual with the identity of the strains obtained by the Centers for Disease Control Anaerobe Reference Laboratory by using conventional procedures. We also compared reactions obtained with the Presumpto plates with a chopped meat glucose broth culture as a source of inoculum with those obtained by using a turbid cell suspension from growth on blood agar as inoculum. The agreement of results for the 16 characteristics compared ranged from 92.8 to 100%. Comparison of test results obtained with 10 media in the Presumpto plate and A/T systems from the examination of 223 strains of anaerobes, representing 54 different taxa, showed the following agreement between A/T and CDC systems: catalase production, esculin hydrolysis, glucose fermentation, and lecithinase production (100%); inhibition of growth by bile agar (99.6%); lipase production (99%); DNase (98.7%); fermentation of lactose and mannitol (98.2%); starch hydrolysis (96.9%); gelatin hydrolysis (96.4%); and casein hydrolysis (94.6%). Of the 204 strains of common anaerobes tested with the A/T system, only 70% were correctly identified to the species level. However, several strains could have been identified correctly with the A/T system if data on certain other characteristics had been included in the A/T data base.
Detection of enterotoxigenic Escherichia coli in water by filter hybridization with three enterotoxin gene probes
Authors: Echeverria P , Seriwatana J , Chityothin O , Chaicumpa W , Tirapat C
Published: January 2020

The DNA hybridization assay for genes encoding for Escherichia coli enterotoxins was used to examine water specimens in Thailand. In a reconstruction experiment, the DNA hybridization assay was 10(4) times more sensitive than testing random E. coli in the Y-1 adrenal and suckling mouse assays in identifying enterotoxigenic E. coli (ETEC) in water. Drinking and bathing water collected from 2 of 10 different homes of individuals with ETEC-associated diarrhea and 6% (5 of 78) and 11% (11 of 78) of drinking and bathing water samples collected from homes of individuals with diarrhea without ETEC infections, as well as 6% (5 of 77) and 8% (6 of 77) of drinking and bathing water collected from homes in which no inhabitants had diarrhea, were homologous with the DNA probes. Ten E. coli from each of the 31 water specimens which contained bacteria which were homologous with the DNA probes were tested in the Y-1 adrenal and suckling mouse assay. In only 2 of these 31 specimens could ETEC be identified with the standard assays. The DNA hybridization assay is a much more sensitive means of detecting organisms carrying genes coding for enterotoxin production than testing 10 individual colonies in the Y-1 adrenal and suckling mouse assays. This novel application of recombinant DNA technology provides a sensitive method of detecting organisms carrying genes coding for enterotoxin, and this method will be useful in defining the epidemiology of ETEC.
Intestinal spirochetosis: morphological characterization and cultivation of the spirochete Brachyspira aalborgi gen. nov., sp. nov
Authors: Hovind-Hougen K , Birch-Andersen A , Henrik-Nielsen R , Orholm M , Pedersen J O , Teglbjaerg P S , Thaysen E H
Published: January 2020

The ultrastructure of spirochetes obtained from rectal biopsies of patients with intestinal spirochetosis was studied by means of negative staining and ultrathin sectioning. The cells were sigmoidal with tapered ends, 2 to 6 microns long, with a wavelength of 2 microns. Four flagella were inserted at each end of the cells. The maximal cell width was about 0.2 microns. The spirochetes were cultured on tryptose soy blood agar plates. They were anaerobic and grew, although very slowly, at 37 to 38.5 degrees C in an atmosphere of 5% CO2-95% H2. Two types of colonies could be distinguished. The growth characteristics and the morphology of the isolated spirochetes differ from those of previously isolated spirochetal strains. Consequently, it is proposed that the present strains constitute a new genus, Brachyspira, of the family Treponemataceae. The type species is Brachyspira aalborgi, the type strain of which is 513A (NCTC 11492).
Detection of genital herpes simplex infections by a tissue culture-fluorescent-antibody technique with biotin-avidin
Authors: Nerurkar L S , Jacob A J , Madden D L , Sever J L
Published: January 2020

Several cell lines were evaluated for their suitability for rapid detection of herpes simplex virus (HSV) from clinical genital specimens. Human foreskin fibroblast (Flow 7000) cells were found to be most suitable in terms of sensitivity and adherence characteristics. HSV in clinical specimens was isolated by a standard tissue culture method by monitoring the cytopathic effect, and the titers of the HSV-positive specimens were determined. More than 65% of the HSV-positive genital specimens showed titers of less than or equal to 10(4) 50% tissue culture infective doses per ml. The standard tissue culture-cytopathic effect method required 3 to 10 days for detection of HSV in clinical specimens of low infectivity. A more rapid technique was developed which involved a short-term tissue culture (24 h) on Lab-Tek chambers followed by staining with biotin-linked HSV antibody and avidin-fluorescein conjugate. Because of the high binding affinity of this system due to multiple binding of biotin to avidin and multiple attachment of biotin to the antibody molecule, the biotin-avidin fluorescent-antibody technique produced a quality of fluorescence far superior to that of the conventional fluorescent-antibody techniques. The tissue culture-biotin-avidin fluorescent-antibody method was as sensitive as the tissue culture-cytopathic effect test. This method provides an improved, more rapid test (26 h) for detecting HSV in clinical specimens.
First Case of Subcutaneous Phaeohyphomycosis Caused by
Scytalidium lignicola
in a Human
Authors: Dickinson Gordon M. , Cleary Timothy J. , Sanderson Tamara , McGinnis Michael R.
Published: January 2020

A case of subcutaneous phaeohyphomycosis in a human, involving the ankle and caused by
Scytalidium lignicola
, is described. The isolate was found to be sensitive to amphotericin B, 5-fluorocytosine, miconazole, and ketoconazole in vitro.
Bacteriophage types of Salmonella typhi in the United States from 1974 through 1981
Authors: Hickman-Brenner F W , Farmer J J
Published: January 2020

From 1974 through 1981, 4,089 isolates of Salmonella typhi were phage typed at the Centers for Disease Control and nine regional laboratories in the United States. The most prevalent types were degraded Vi (27%), E1 (20.6%), A (9.8%), C1 (5.7%), untypable Vi (3.5%), W form (3.5%), D1 (3.4%), B3 (3.4%), and F1 (2.4%). There were less than 2% of each of the remaining types. The distribution of phage types for this time period was similar to that seen in the periods 1966-1969 and 1970-1973, except that phage type B3 was one of the 10 most prevalent types in 1974-1981 but was not seen in 1966-1973. Phage typing is presently the most valuable laboratory tool for differentiation of strains of S. typhi in epidemiological studies.
Growth of host cells and Chlamydia trachomatis in medium containing serum from 16-week-old calves
Authors: Levy N J , Benes S , McCormack W M
Published: January 2020

We compared fetal bovine serum with five batches of serum from calves of various ages. HeLa and McCoy cells grown in only one batch of calf serum (from 16-week-old calves) had morphology, growth kinetics, and cloning efficiency similar to those of cells grown in fetal bovine serum. Cells maintained in calf serum from this batch supported the growth of two laboratory strains of Chlamydia trachomatis, a genital strain (E/UW-5/Cx) in McCoy cells and a lymphogranuloma venereum strain (440L) in HeLa cells. McCoy cells maintained in calf serum also supported the growth of C. trachomatis from clinical specimens. The batch of serum from 16-week-old calves was an effective alternative to fetal bovine serum for the growth of cells and of C. trachomatis. Other laboratories may be able to use calf serum for the maintenance of cells and for the isolation of Chlamydia spp. Before use, however, each batch of calf serum will have to be carefully evaluated to ensure that it is equivalent to fetal bovine serum.
Rapid Method for Detection, Identification, and Susceptibility Testing of Enteric Pathogens
Authors: Stager Charles E. , Erikson Eric , Davis James R.
Published: January 2020

Three hundred and seven colonies believed to be enteric pathogens were selected from primary plates of MacConkey, xylose desoxycholate, or salmonella-shigella agar for inoculation to lactose-sucrose broth, urea-41 motility medium, modified Andrade glucose broth with inverted Durham tube, pregrowth broth, triple sugar iron agar, lysine iron agar (LIA), and Christensen urea agar. The rapid screen consisted of interpreting the lactose-sucrose, urea-41 motility, and modified Andrade glucose broth gas reactions after 4 to 6 h at 35°C. These rapid screening biochemicals plus LIA were incubated for 24 h if further interpretation was required. Reference biochemicals (triple sugar iron, LIA, and Christensen urea agars) were interpreted at 24 h. Of 307 isolates, 49 (16%) were reported as negative for enteric pathogens after 4 to 6 h because their biochemical profiles were not compatible with those for enteric pathogens. A total of 87 (28.3%) isolates produced biochemical profiles at 4 to 6 h that were presumptive for enteric pathogens. The 87 presumptive pathogens were inoculated into the AutoMicrobic system Gram-Negative General Susceptibility Card and the AutoMicrobic system
Enterobacteriaceae
-Plus Biochemical Card (AMS-EBC+) after 4 to 6 h of growth in pregrowth broth. Of these isolates, 63 were confirmed to be enteric pathogens, of which 61 (96.8%) were correctly identified by the AMS-EBC+. One isolate was identified as
Shigella dysenteriae
by AMS-EBC+ but confirmed as
Shigella flexneri
biotype 6 by a reference laboratory. The other isolate was identified as
Arizona hinshawii
by AMS-EBC+ but was confirmed as
Salmonella enteritidis.
Of the 307 isolates, 166 (54.1%) required further interpretation of the rapid screening biochemicals plus LIA at 24 h; 5 of these were detected as enteric pathogens. The same 68 enteric pathogens were detected by both the rapid method and the reference method. The results from the general susceptibility card agreed with agar diffusion results at 99.2%. One
Salmonella enteritidis
and four
Shigella
spp. showed minor discrepancies with tetracycline. No very major or major discrepancies were observed.
Selective recovery of oral Capnocytophaga spp. with sheep blood agar containing bacitracin and polymyxin B
Authors: Mashimo P A , Yamamoto Y , Nakamura M , Slots J
Published: January 2020

On the basis of in vitro susceptibility testing of antibiotics, dyes, and other antimicrobial agents, we developed and evaluated a medium, TBBP, for the selective isolation of oral Capnocytophaga spp. TBBP medium consists of 4% Trypticase soy agar (BBL Microbiology Systems, Cockeysville, Md.), 5% sheep blood, 0.1% yeast extract, 50 micrograms of bacitracin per ml, and 100 micrograms of polymyxin B per ml. A total of 34 Capnocytophaga stock cultures grew well on TBBP medium. Except for some streptococcal strains, TBBP medium inhibited growth of all test stock culture isolates of common oral gram-positive and gram-negative species. In a clinical study of 15 deep periodontal pockets, TBBP medium demonstrated Capnocytophaga recoverability that was similar to or higher than that shown by a nonselective blood agar medium. Typical Capnocytophaga colonial morphology enabled us to readily distinguish this organism from the few other bacteria which could grow on TBBP medium.
Inhibition of nonspecific streptococcal coagglutination reactions
Authors: Giunta S , Sampaoli G , Galeazzi L , Bilei L , Rinaldi R , Groppa G
Published: January 2020

The reliability of latex coagglutination testing for the serological grouping of hemolytic streptococci is limited by the relatively high incidence of false-positive reactions. Pretreatment of streptococcal suspensions with antisera for the various groups that show clumping gives a specific inhibition of the latex agglutination with the true group, whereas the other groups continue to agglutinate aspecifically. The method is rapid and easy to perform, allows the exact grouping of those streptococci giving aspecific reactions, and is also a useful confirmatory test with monoreactive strains.
Isolation of Legionella pneumophila serogroup 1 from blood with nonsupplemented blood culture bottles
Authors: Chester B , Poulos E G , Demaray M J , Albin E , Prilucik T
Published: January 2020

Legionella pneumophila serogroup 1 was isolated from antemortem aerobic blood culture bottles not supplemented with L-cysteine or ferric pyrophosphate and from the postmortem lung tissue of a 72-year-old man. We recommend that aerobic blood culture bottles (Johnston Laboratories, Cockeysville, Md.) of BACTEC be subcultured to an agar that supports the growth of L. pneumophila when growth indexes range from 30 to 60 but fail to increase further.
Reproducible enzyme-linked immunosorbent assay with a magnetic processing system for diagnosis of toxoplasmosis
Authors: Konishi E , Takahashi J
Published: January 2020

An enzyme-linked immunosorbent assay with polycarbonate-coated iron beads as the solid phase and with magnetic processing devices was evaluated for the quantitation of antibodies to Toxoplasma gondii in human serum samples. Under the parameters and other basic conditions determined in this study, the assay was highly reproducible: coefficients of variation for the absorbance values obtained with the positive serum were 2.42% in same-day tests and 3.75% in day-to-day tests. Significant correlations were observed between the present assay system and other conventional serological tests: correlation coefficients were 0.960 with the dye test and 0.929 with the latex agglutination test. Statistical analysis based on the frequency distribution of absorbance values for dye-test-positive and dye-test-negative serum samples gave feasible border lines for distinguishing between positive and doubtful samples (0.357) and between doubtful and negative samples (0.266). Under this diagnostic criterion, the results of our assay system agreed remarkably well with those obtained by the dye test and the latex agglutination test, with consistencies of 94.9 and 93.9%, respectively.
Species identification and biotyping of staphylococci by the API staph-ident system
Authors: Doern G V , Earls J E , Jeznach P A , Parker D S
Published: January 2020

The API Staph-Ident system, a commercially available biochemical and chromogenic substrate micromethod, was evaluated as a means for identifying the species and determining the biotypes of human strains of staphylococci routinely encountered in a clinical microbiology laboratory. The species identity of 152 of 188 (80.9%) unique clinical isolates of staphylococci was correctly predicted by this method after 5 h of incubation according to the recommendations of the manufacturer. When results were determined after 24 h of incubation, the overall accuracy of this procedure was 90.4%. The API Staph-Ident system was not an adequate procedure for assessing strain biotypes since the patterns of biochemical reactivity observed with 53 of 54 (98.2%) unique isolates of Staphylococcus aureus were identical. Similarly, 58 of 62 (93.6%) different strains of S. epidermidis yielded the same biochemical profile.
Comparison of tryptic soy broth with tryptic soy broth supplemented with sucrose in the septi-chek blood culture system
Authors: Pfaller M A , Westfall L M , Niles A C , Kinroth A , Murray P R
Published: January 2020

The performance of tryptic soy broth (TSB) was compared with TSB supplemented with 10% sucrose (TSB-S) in the Septi-Chek blood culture system (Roche Diagnostics, Div. Hoffmann-La Roche Inc.). A total of 2,292 sets of blood cultures were evaluated. Although slightly more isolates were recovered in the TSB bottle in comparison with the TSB-S bottle, there was no significant difference between the two medium formulations in the recovery of either gram-positive or gram-negative bacteria. Significantly more isolates of fungi were recovered in the TSB bottles. At least 94% of all isolates were detected by day 3 of incubation in both the TSB and TSB-S bottles. Thus, the addition of sucrose to TSB did not result in greater total recovery or faster recovery of the isolates detected in this study.
Measurement of Antibody to
Ureaplasma urealyticum
by an Enzyme-Linked Immunosorbent Assay and Detection of Antibody Responses in Patients with Nongonococcal Urethritis
Authors: Brown Mary B. , Cassell Gail H. , Taylor-Robinson David , Shepard Maurice C.
Published: January 2020

The optimum conditions for the detection of human immunoglobulin G (IgG), IgM, and IgA antibodies to
Ureaplasma urealyticum
by an enzyme-linked immunosorbent assay (ELISA) were established by using a cell lysate antigen and commercially available alkaline phosphatase conjugates. No significant cross-reactions were observed among rabbit antisera to a variety of mycoplasmas of human origin and ureaplasma antigen, thus demonstrating the specificity of the ELISA. All human sera were assayed at a 1:200 dilution. Antigen was used at 20 μg of protein/ml and conjugates were diluted 1:500. Presence of IgG antibody to
U. urealyticum
was significantly associated with isolation of
U. urealyticum
(
P
< 0.001) in 110 women. Seventeen acute-phase and 19 convalescent-phase sera from male nongonococcal urethritis (NGU) patients were tested for the presence of antibody by both the metabolism inhibition assay and by ELISA, with overall agreements of 82 and 95% for acute- and convalescent-phase sera, respectively. Serum antibody responses were demonstrated to selected serotypes in the metabolism inhibition test, but the response as measured by the ELISA was independent of the serotype of the antigen used. Serum antibody levels in NGU patients were significantly higher (
P
< 0.002) than the normal serum standard in the IgG, IgM, and IgA classes. Additionally, the magnitude of change between acute- and convalescent-phase sera was greater for NGU patients than for normal asymptomatic ureaplasma-positive male controls. A significant change in antibody levels of one or more antibody classes was detected for 12 of 18 (67%) NGU patients by ELISA. Ten of the 12 (83%) individuals had a change in the IgM class, which is suggestive of an active infectious process. The ELISA is advantageous in that it requires only a single serotype antigen, uses one serum dilution, is class specific, and allows quantitative detection of differences between acute- and convalescent-phase sera.
Determination of antigenic relationships among legionellae and non-legionellae by direct fluorescent-antibody and immunodiffusion tests
Authors: Orrison L H , Bibb W F , Cherry W B , Thacker L
Published: January 2020

Six isolates, five from water samples and one from a human tracheal swab taken at autopsy, reacted strongly with working dilutions of Legionella fluorescent-antibody conjugates. Of these, two isolates of Pseudomonas fluorescens (EB and CDC93), one isolate of the Flavobacterium-Xanthomonas group (CDC65), and one isolate of P. alcaligenes (CDC11) reacted with Legionella pneumophila serogroup 1 conjugate. P. alcaligenes ABB 50 reacted with an L. pneumophila serogroup 3 conjugate and of P. maltophilia reacted with the L. micdadei conjugate. Antisera and labeled conjugates were prepared for these new cross-reacting isolates, and their relationships to the legionellae were examined by direct fluorescent-antibody and immunodiffusion tests. A nonreciprocal cross-reaction existed between L. micdadei and P. maltophilia and also between serogroups 3 of L. pneumophila and P. alcaligenes ABB50. Of the four isolates that reacted with serogroup 1 of L. pneumophila, P. fluorescens CDC93 had the strongest relationship, and the other three had only minor relationships. Although cross-reactivity among non-legionellae and legionellae has not been a major problem, these findings are relevant to the interpretation of direct fluorescent-antibody tests for detecting these bacteria.
Detection and recovery of mycobacteria by a radiometric procedure
Authors: Takahashi H , Foster V
Published: January 2020

During a 6-month period, 5,375 clinical specimens were cultured on Middlebrook-Cohn 7H10 medium, on Lowenstein-Jensen medium, and in Middlebrook 7H12 medium containing [14C]palmitic acid. More mycobacteria were recovered when all three media were used than when either the conventional method with 7H10 agar and Lowenstein-Jensen slants or the radiometric method with 7H12 broth was used alone.
Identification of pathogenic Neisseria species with the RapID NH system
Authors: Robinson M J , Oberhofer T R
Published: January 2020

The RapID NH system (Innovative Diagnostics Systems, Inc., Decatur, Ga.) is a 4-h test used in the identification of Neisseria and Haemophilus species. The system was evaluated for accuracy and reliability and compared with conventional (cystine proteose peptone agar; Prepared Media Laboratory, Tualatin, Ore.) carbohydrate degradation tests with Neisseria gonorrhoeae and N. meningitidis, as well as a variety of Neisseria, Branhamella, and Moraxella species. The RapID NH system correctly identified all N. gonorrhoeae, N. meningitidis, and N. lactamica isolates, but the level of accuracy varied considerably for the remaining organisms. One strain of N. subflava was misidentified as a pathogenic Neisseria strain. The RapID NH tests were concluded in 4 h, whereas the cystine proteose peptone agar tests required up to 48 h for results to be useful. The RapID NH system is an accurate, reliable, and useful method for the identification of pathogenic Neisseria species. It has been proven that it shortens identification time and specimen turnaround time by at least 24 h.
Bactericidal antibodies against noncapsular components of Haemophilus influenzae
Authors: Dahlberg-Lagergård T
Published: January 2020

Bactericidal antibodies against components of Haemophilus influenzae other than the capsular polysaccharide were analyzed in sera from patients infected with this organism and compared with the antibody levels in sera from a normal population. Such antibodies could be demonstrated in sera from about one-third of patients infected with H. influenzae type b, including children less than 1 year old. It is possible that these antibodies were directed against outer membrane proteins, since they persisted after absorption with capsular polysaccharide type b and lipopolysaccharide. These findings suggest a protective role for antibodies directed against outer membrane components, possibly proteins, in infections caused by capsulated strains of H. influenzae.
Lack of Virus-Specific Bacterial Adherence to Bovine Embryonic Lung Cells Infected with Bovine Parainfluenza Virus Type 3
Authors: Toth Thomas E. , Gates Connie
Published: January 2020

Infection of bovine embryonic lung cells with bovine parainfluenza virus type 3 did not induce in vitro, virus-specific, hemadsorption-related adherence of
Corynebacterium pyogenes, Haemophilus somnus, Staphylococcus aureus, Streptococcus zooepidemicus, Pasteurella haemolytica, Listeria monocytogenes, Escherichia coli, Pasteurella multocida, Brucella
sp., or
Salmonella typhimurium
.
Value of routine aerobic subculturing of unvented blood culture bottles
Authors: Pfaller M A , Westfall L M , Murray P R
Published: January 2020

The value of performing routine aerobic subcultures of both vented and unvented blood culture bottles has not been evaluated critically. We studied 4,954 pairs of blood culture bottles consisting of one vented biphasic tryptic soy broth bottle (Roche Diagnostics) and one unvented Thiol broth bottle (Difco Laboratories). A total of 736 isolates were detected, of which 124 (17%) were in the Thiol broth bottle only. Some 15 isolates were detected only by subculturing the Thiol broth, and 13 of these isolates either were contaminants or were detected in previous positive cultures. Similar results were obtained when the unvented Thiol broth bottle was paired with a vented Difco tryptic soy broth bottle. Analysis of these pairs revealed a total of 360 isolates detected in 2,669 pairs of bottles, of which 83 isolates (23%) were in the Thiol broth bottle only. There were 11 isolates seen only in subcultures of the Thiol broth bottle, and 8 of these were probable contaminants. Thus, routine subculturing of unvented Thiol broth bottles had limited value. These results may differ with the use of other culture media or subculturing procedures. We recommend that each laboratory evaluate critically its experience with aerobic subcultures from unvented bottles.
Rapid, Radiolabeled-Microculture Method That Uses Macrophages for In Vitro Evaluation of
Mycobacterium leprae
Viability and Drug Susceptibility
Authors: Mittal A. , Sathish M. , Seshadri P. S. , Nath Indira
Published: January 2020

This paper describes a microculture rapid assay using radiolabeling and mouse macrophages to determine the viability and the drug susceptibility or resistance of
Mycobacterium leprae.
Comparison of
M. leprae
resident macrophage cultures maintained in 96-well flat-bottomed plates showed results for viability and susceptibility or resistance to dapsone that were similar to results for concurrent cultures in Leighton tubes with greater numbers of bacilli and macrophages.
Dark-field microscopy for detection of malaria in unstained blood films
Authors: Jamjoom G A
Published: January 2020

Pigment present in different forms of Plasmodium species infecting humans exhibits light scattering when blood films are viewed by dark-field microscopy. This facilitates the detection of parasite-infected cells owing to their brightly illuminated appearance. The technique was described long ago for the detection of certain highly pigmented forms of malarial parasites such as schizonts and gametocytes but has not found an application in routine diagnosis. Here, modifications are described which allow the detection of all forms of human malarial parasites, including ring forms, in unstained blood films. The technique offers the distinct advantages of rapid diagnosis, increased sensitivity, and adaptability to field work.
Antibodies against Entamoeba histolytica in human milk and serum in Kenya
Authors: Grundy M S , Cartwright-Taylor L , Lundin L , Thors C , Huldt G
Published: January 2020

A modified enzyme-linked immunosorbent assay (ELISA) technique has been developed for the detection of secretory immunoglobulin A (SIgA) antibodies against Entamoeba histolytica. By substituting phosphate-buffered saline-Triton for phosphate-buffered saline-Tween as the antibody incubating buffer, unspecific absorption of SIgA was avoided. As revealed by chessboard titrations, the optimal amount of antigen for coating was higher in SIgA than in IgG ELISA. A purified antigen from the membrane pellet fraction of E. histolytica gave equally good reactivity with SIgA and IgG antibodies and was used throughout. A total of 283 milk and 232 serum samples from three areas in Kenya were tested. The samples were collected in maternity hospitals on one of days 1 to 3 after parturition. All milk samples were tested for total SIgA. In one of the study areas (Machakos), the mean level of SIgA was significantly lower than in the other two areas (Mombasa and Nairobi). Eighty-seven of the milk samples (31%) were reactive in the test. The rate of positives was higher in Mombasa, where the SIgA levels were highest. Since both the frequency and the level of serum antibodies were similar in the three study areas, it is likely that the higher milk reactivity in Mombasa was mainly due to the higher SIgA concentrations observed. Antibodies were detected in 32 (14%) of the sera, mostly in low or moderate titers. Surprisingly few mothers had detectable antibodies in both milk and serum. In fact, the majority of positives were reactive in either milk or serum, with a predominance of milk positives. The background for this is probably complex, containing components such as differences in immunoglobulin concentrations in the samples, diversities in local and systemic antigenic stimulation responses, and level of immunological memory.
Enzyme-linked immunosorbent assay for detection of measles antibody
Authors: Boteler W L , Luipersbeck P M , Fuccillo D A , O'Beirne A J
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of measles immunoglobulin G antibody (MEASELISA). This assay was found to be comparable to the measles hemagglutination inhibition (HAI) test. Approximately 500 sera from three centers were tested by MEASELISA and the HAI test. MEASELISA demonstrated values of greater than 99% for sensitivity, specificity, and accuracy. Values were very precise, with a mean coefficient of variation of 5.4%. MEASELISA values were shown by linear regression analysis to increase as HAI titers increased. A coefficient of determination of 1.00 was obtained from test center three. MEASELISA values were found to be linearly related (r2 greater than 0.97) to MEASELISA titers, thus enabling quantitation of measles antibody from a single value. Also, data are presented that show MEASELISA to be equivalent to complement fixation for evaluating paired sera for the presence of a significant increase in antibody levels to measles virus.
Influence of age, sex, and diet on asymptomatic colonization of infants with Clostridium difficile
Authors: Cooperstock M , Riegle L , Woodruff C W , Onderdonk A
Published: January 2020

A total of 40% of 107 stool samples from infants 1 to 52 weeks of age were found to contain Clostridium difficile antigens, detected by counterimmunoelectrophoresis. Within the group tested, there was no detectable variation by age or sex. Infants fed formula were nearly four times more likely to carry C. difficile than were those exclusively breast fed (62 versus 16%), whereas breast-fed infants also receiving formula or solids had an intermediate rate of colonization (35%). The distributions were similar when a subgroup with the highest levels of antigen was assessed separately. These data will be useful in considering potential pathogenic activities of C. difficile colonization in infancy.
Enzyme-linked immunosorbent assay for immunoglobulin G and M antibodies to Chlamydia trachomatis in human sera
Authors: Finn M P , Ohlin A , Schachter J
Published: January 2020

Microimmunofluorescence methods used for detection of immunoglobulin G and M antibodies to Chlamydia trachomatis are not available to many clinical laboratories. We evaluated a simple enzyme-linked immunosorbent assay in which serotype L2 elementary bodies are used as antigen. The enzyme-linked immunosorbent assay proved satisfactory for the detection of serum IgG. A total of 160 human sera were tested, and the results correlated well with those obtained by microimmunofluorescence. Results for IgM antibody detection were not as successful, and correlation with current methods was poor.
Isolation of nontoxigenic Vibrio cholerae O1 from a human wound infection
Authors: Johnston J M , McFarland L M , Bradford H B , Caraway C T
Published: January 2020

Vibrio cholerae serotype O1 organisms that do not produce cholera toxin and, in fact, lack the genetic material encoding the enterotoxin have recently been detected in coastal regions of the United States. Although these organisms have been assumed to be nonpathogenic, they have been considered a potential reservoir of toxigenic V. cholerae. In 1979, nontoxigenic V. cholerae O1 was isolated from a leg wound of an accident victim residing in New Orleans. The only known risk factors of the patient, besides his debilitated condition, were alcoholism and the consumption of raw oysters before recognition of his wound infection. Coincident with the identification of the isolate from the leg wound, an identical nontoxigenic V. cholerae O1 isolate was cultured from the sewage system serving the residence of this patient. Nontoxigenic V. cholerae O1 seems to be capable of multiplying in human tissue and may produce extraintestinal infection. This indigenous inhabitant of temperate coastal regions may not be avirulent and may be of public health significance.
Endotoxin contamination of enzyme conjugates used in enzyme-linked immunosorbent assays
Authors: Bryant R E , Chamovitz B N , Morse S A , Apicella M A , Morthland V H
Published: January 2020

The specificity of the enzyme-linked immunosorbent assay(s) is thought to depend on the specificity of the antibody used in the assay system. Therefore, the association of broadly reactive antigens like endotoxin with enzyme conjugates or other enzyme-linked immunosorbent assay reagents has the potential of altering the specificity of reactions in the enzyme-linked immunosorbent assay. Using the Limulus amoebocyte lysate assay, we demonstrated that commercially prepared conjugates of goat anti-human immunoglobulin G peroxidase, goat anti-rabbit immunoglobulin G alkaline phosphatase, rabbit anti-human immunoglobulin G, and other enzyme conjugates contained endotoxin. Furthermore, the staphylococcal protein A, horseradish peroxidase, and bovine alkaline phosphatase used to prepare enzyme conjugates also contained endotoxin. Commercially obtained bovine alkaline phosphatase contained as much as 1.0 microgram of endotoxin per ml of enzyme solution. Both commercially prepared enzyme conjugates and those prepared by us contained endotoxin as determined by their absorption to immobilized monoclonal antibody to lipid A or to immobilized Limulus amoebocyte lysate. The results of this study further suggest that the endotoxin was associated with the enzyme component of the conjugate. In a competitive inhibition enzyme immunoassay, 10 micrograms of lipid A per ml inhibited binding of the enzyme conjugate to adsorbed Limulus amoebocyte lysate, thereby confirming that endotoxin mediated the binding of the conjugate in that system. The potential significance of endotoxin bound to enzyme conjugates may be far reaching because of the ubiquity of endotoxin in conjugates and the prevalence of antibodies to endotoxin in mammalian serum.
Urine screening with the MS-2
Authors: Hoban D J , Koss J C , Gratton C A , Ronald A R
Published: January 2020

A study was undertaken to evaluate the effectiveness of the MS-2 (Abbott Laboratories, Dallas, Tex.) in screening urine specimens in a large clinical laboratory. A total of 15,319 urine specimens (9,954 midstream specimens and 5,365 catheter specimens) were evaluated with the MS-2 and by a surface streak procedure. The study was conducted in two phases, differing in that phase II urine specimens were evaluated in the MS-2 by using a program software update (03.01). For midstream urine specimens, MS-2 detection rates in phases I and II were, respectively, 94.5 and 94.3% at a plate count of greater than 10(5) CFU/ml, 74.4 and 65.3% at plate counts of 5 X 10(4) to 1 X 10(5) CFU/ml, 55.0 and 52.4% at plate counts of 1 X 10(4) to 5 X 10(4) CFU/ml, 31.2 and 20.5% at plate counts of 10(3) to 10(4) CFU/ml, and 15.7 and 6.4% at plate counts of less than 10(3) CFU/ml. For catheter urine specimens, the MS-2 detection rates in phases I and II were, respectively, 95.4 and 96.8% at plate counts greater than 10(5) CFU/ml, 74.4 and 85.7% at plate counts of 5 X 10(4) to 1 X 10(5) CFU/ml, 50.0 and 44.4% at plate counts 10(4) to 5 X 10(4) CFU/ml, 25.6 and 14.9% at plate counts of 10(3) to 10(4) CFU/ml, and 14.7 and 5.2% at plate counts less than 10(3) CFU/ml.
Serotyping of Pasteurella multocida isolated from swine lungs collected at slaughter
Authors: Pijoan C , Morrison R B , Hilley H D
Published: January 2020

We serotyped 222 Pasteurella multocida strains isolated from swine lungs at slaughter. Capsular serotypes A and D were determined by the hyaluronidase sensitivity and acriflavin agglutination tests, respectively. Somatic antigens were determined by gel diffusion against standard antisera. Capsular serotype A was found in 97.3% of the strains and serotype D in the remaining 2.7%. The primary somatic antigen most commonly found was type 3 (86.0%). Type 5 was also very common (88.7%), but was usually a secondary antigen. The most common overall serotype was A:3(5) (39.2%). Other common serotypes were: A:3(4,5,12) (12.2%); A:3(4,5) (11.2%); A:3(5,12) (10.4%); A:3 (6.8%); and A:5 (6.8%). Type D strains had a similar distribution of serotypes, but with a higher prevalence of D:5 (33.3%) and D:3(5) (33.3%).
Plasmid profiles of value in differentiating Salmonella muenster isolates
Authors: Bezanson G S , Khakhria R , Pagnutti D
Published: January 2020

Strains of Salmonella muenster displaying identical antibiotic susceptibility and bacteriophage reaction patterns were found to differ in their complements of plasmid DNA. Plasmid profiles were used to separate 40 isolates from diverse sources into four distinct groups, one of which contained 30 strains without plasmids.
Hybridoma-derived monoclonal immunoglobulin M antibodies to Legionella pneumophila serogroup 1 with diagnostic potential
Authors: Sethi K K , Drüeke V , Brandis H
Published: January 2020

Mouse hybridomas were isolated by fusing P3-X63-Ag 8.653 myeloma cells with spleen cells from mice that had been repeatedly immunized with Legionella pneumophila serogroup 1 organisms. In one fusion, three independent hybridoma cultures which secreted antibodies that reacted with the immunizing strain in the indirect immunofluorescent-antibody test were selected for cloning. Representative continuously growing clones, one of each hybridoma, which remained stable in producing high-titer antibodies were examined in detail. Extensive specificity tests revealed that these hybridoma-derived monoclonal antibodies were specifically directed against L. pneumophila serogroup 1 organisms and showed no cross-reactions in the indirect immunofluorescent-antibody test either with the other known serogroups of L. pneumophila or with other unrelated bacterial species. The three monoclonal antibodies F4/CB5/K18, F/4CB5/K104, and F4/JD3.8/K101 belonged to the immunoglobulin M class and were capable of agglutinating serogroup 1 organisms of L. pneumophila exquisitely. These monoclonal antibodies against L. pneumophila with defined fine specificity should enable purification and subsequent analysis of the corresponding antigenic determinant(s) and can also be used for the preparation of unlimited supplies of standard diagnostic reagents for the identification of L. pneumophila in the tissues and body fluids.
Serological classification of Haemophilus paragallinarum with a hemagglutinin system
Authors: Kume K , Sawata A , Nakai T , Matsumoto M
Published: January 2020

Antigens, prepared from 17 strains of Haemophilus paragallinarum by treatment with potassium thiocyanate followed by sonication, uniformly agglutinated glutaraldehyde-fixed chicken erythrocytes and formed specific hemagglutination inhibition antibodies in rabbits. Attempts were made to classify the strains into serotypes by a combination of cross-hemagglutination inhibition and cross-absorption tests, using the hemagglutinating antigens, designated as HA-L hemagglutinin, and their antisera. The cross-hemagglutination inhibition tests showed the existence of three distinct groups among the 17 strains. Further cross-absorption studies indicated that two of the three groups could be subdivided into three serotypes each, forming a total of seven serotypes, designated HA-1 through HA-7. Classification based on the serotype-specific HA-L system was found to be superior in its wider and more clearly defined specificities to other previous classifications, which are based on the agglutination test. There appeared to be a correlation between serotypes and geographic origins of the strains.
Species distribution of non-group D alpha-hemolytic streptococci in maternal genital and neonatal blood cultures
Authors: Haffar A A , Fuselier P A , Baker C J
Published: January 2020

At our hospital (Jefferson Davis Hospital, Houston, Tex.) since 1979, non-group D alpha-hemolytic streptococci have been isolated with increasing frequency from neonatal blood cultures with clinical findings of sepsis. A total of 47 such isolates were identified to the species level by the scheme of Facklam and were compared with 57 genital isolates from 167 maternity patients. Among the genital isolates, S. sanguis II and S. MG-intermedius accounted for 53 and 28%, respectively, and both were significantly less common in neonatal cultures (23 and 11%, respectively; P less than 0.05). Among neonatal isolates, S. mitis was the single most frequent species (35%), in contrast to its rare occurrence in maternal cultures (3.4%; P less than 0.001). The disparity between the prevalence of S. mitis in neonatal compared with maternal cultures suggests that this species of non-group D alpha-hemolytic streptococci may have increased virulence in neonatal hosts.
Reaction of clinical isolates and typed strains of the family Bacteroidaceae with rabbit anti-Bacteroides sera examined by radial immunodiffusion
Authors: Shaefer D F , Falkler W A
Published: January 2020

Antisera were produced which were reactive with Bacteroides fragilis, B. gingivalis, or B. melaninogenicus subsp. melaninogenicus. Anti-B. gingivalis serum exhibited strong reactions with strains of homologous species and reacted with only one other species, B. thetaiotaomicron. Antigens shared by organisms of the B. fragilis group and B. melaninogenicus subspecies of the Bacteroidaceae must be considered when serological methods are used for their identification.
Endemic gentamicin resistance R factors on a spinal cord injury unit
Authors: Shlaes D M , Currie C A
Published: January 2020

Cleared lysates of gentamicin-resistant, gram-negative bacilli obtained during a prevalence survey and a subsequent prospective study on a spinal cord injury unit were analyzed. Of 105 strains obtained during the epidemiological study, 62 were analyzed for plasmid content. None of the 14 Acinetobacter strains carried plasmids. Of 20 strains from the initial prevalence survey, 9 carried a 36- or (in two cases) a 27-megadalton plasmid. Eight of the nine were Providencia strains; none were Pseudomonas strains. Of 28 nosocomial isolates obtained during the prospective survey, 22 carried plasmids of similar molecular weight (P less than 0.025, compared with the prevalence survey), including 20 of 22 isolates of members of the family Enterobacteriaceae and 2 of 6 Pseudomonas aeruginosa isolates. Conjugation, curing, and transformation indicate that these plasmids carry gentamicin, tobramycin, kanamycin, ampicillin, carbenicillin, cephalothin, and, variably, chloramphenicol resistance. Restriction endonuclease digestion of purified plasmid DNA suggests that the plasmids from multiple species of the family Enterobacteriaceae contain common sequences, whereas those from Pseudomonas spp. do not. This study suggests that an endemic conjugal 36-megadalton gentamicin resistance R factor exists in many nosocomial species of the family Enterobacteriaceae.
Rapid diagnosis of group A streptococcal antigen extracted directly from swabs by an enzymatic procedure and used to detect pharyngitis
Authors: Otero J R , Reyes S , Noriega A R
Published: January 2020

Coagglutination after enzymatic digestion is a widely used, rapid procedure for serogrouping isolated colonies of beta-hemolytic streptococci. We tried to determine whether the same procedure could be used for the detection of group A streptococcal antigen directly from swabs used to take throat samples. This was achieved by incubating the swabs immersed in a small quantity of lytic extract obtained from cultures of the Maxted strain of Streptomyces griseus and testing the supernatant fluid by coagglutination. Of 538 throat swabs tested, blindly comparing the results of conventional cultures and rapid antigen detection, both tests were negative in 480 and both were positive in 49 swabs. In six cases, culture was positive and the rapid test was negative, but only one swab was from a patient with acute pharyngitis. In three cases, cultures were negative but the rapid test showed a strongly positive reaction. No special instructions were given to the physicians taking the samples. We conclude that this rapid antigen detection test, giving results in approximately 1 h, is an economic and reliable procedure for the detection of group A streptococcal antigen directly from throat samples.