bluuebunny/crossref_metadata_2025 huggingface dataset:
Serodiagnosis of visceral leishmaniasis in an American Peace Corps volunteer
Authors: Chaulk C P , Smith P W , Sass H J
Published: January 2020

A case of visceral leishmaniasis in a young American Peace Corps volunteer is reported. Both clinical and epidemiologic evidence strongly supported the diagnosis; however, hepatic and splenic aspirates for the causative organism were negative. The diagnosis was eventually confirmed through serology, employing indirect immunofluorescence and complement fixation testing of serum. The patient clinically responded dramatically to sodium stibogluconate, the drug of choice for the treatment of visceral leishmaniasis. This case is significant because it alerts the physician to an unusual cause of fever of unknown origin in residents of the Western nations and demonstrates the potential usefulness of serology in diagnosing visceral leishmaniasis when the infecting organism cannot be isolated.
Latex agglutination test for rubella antibodies: report based on data from the College of American Pathologists surveys, 1983 to 1985
Authors: Skendzel L P , Edson D C
Published: January 2020

In the College of American Pathologists (CAP) rubella survey program, 45% of laboratories rely on the latex agglutination (LA) card assay for detecting rubella immunoglobulin G (IgG) antibodies. By using CAP survey data over a 3-year period, we compared LA results with hemagglutination inhibition (HI) and enzyme immunoassay (EIA) results. EIA indices were used to classify results into three categories: nonimmune, EIA index of 0.300 or less; borderline, EIA index of 0.300 to 0.619; and immune, EIA index of 1.700 or greater. There was 91% or more agreement between LA, HI, and EIA for categories i and iii. In category ii, the response from LA users varied, depending on the level of antibody present in the survey samples; at an EIA index of 0.346, 81% reported nonimmune status, whereas at an EIA index of 0.619, 48% reported nonimmune status. Less than 10% indicated borderline status. In testing of samples in the same category, approximately 40%, using the HI method, reported titers of less than 1:8 (nonimmune status). Among EIA users, 97 to 99% regarded the specimens as nonimmune. On analysis of specimens in the borderline category, the LA test showed a pattern of sensitivity and specificity comparable to that reported with the HI technique, whereas the EIA method showed a greater degree of precision. The LA card assay provides a rapid screening test in which LA is read macroscopically, and the procedure differs considerably from the fully quantitative HI and EIA methods.(ABSTRACT TRUNCATED AT 250 WORDS)
Volume of blood submitted for culture from neonates
Authors: Neal P R , Kleiman M B , Reynolds J K , Allen S D , Lemons J A , Yu P L
Published: January 2020

We prospectively examined 298 sets (298 aerobic, 299 anaerobic, and 73 resin cultures) of blood cultures from 161 critically ill newborns. The attending physicians were unaware of the study. The mean blood volume per patient (aerobic and anaerobic) was 1.05 (range, 0.11 to 3.04) ml. The mean blood volume per aerobic bottle was 0.53 (range, 0.01 to 1.90) ml. Among aerobic samples 2.7% were less than or equal to 0.1 ml, 16% were less than or equal to 0.3 ml, 33% were less than or equal to 0.4 ml, and 55% were less than or equal to 0.5 ml. For anaerobic cultures the mean blood volume was 0.52 (range, 0.01 to 1.79) ml. Among anaerobic samples 2.7% were less than or equal to 0.1 ml, 15% were less than or equal to 0.3 ml, 35% were less than or equal to 0.4 ml, and 58% were less than or equal to 0.5 ml. Blood volume did not correlate with gestational age, chronologic age, or weight. The mean volume of blood submitted in positive cultures was not significantly greater than that in negative cultures. The blood volume used for culture from ill newborns may be inadequate for detecting sepsis, and the adequacy of currently available culture methods needs to be assessed for the small samples submitted from critically ill newborns.
Spheroplastic phase of mycobacteria isolated from patients with Crohn's disease
Authors: Chiodini R J , Van Kruiningen H J , Thayer W R , Coutu J A
Published: January 2020

Two strains of an unclassified Mycobacterium species were isolated after 18 and 30 months of incubation of media inoculated with resected intestinal tissues from patients with Crohn's disease. These strains represented the third and fourth isolates of this organism from Crohn's disease patients. Ultrastructural examination of this strain and two previously isolated strains revealed the presence of spheroplasts which eventually transformed into the bacillary form of a previously unrecognized Mycobacterium species. These cell wall-deficient forms did not stain with conventional dyes and failed to grow on hypertonic media. Restriction polymorphism of the ribosomal DNA genes was used to determine the relationship between the cell wall-deficient and bacillary forms. Identical restriction patterns of the ribosomal DNA genes were found between the spheroplasts and Mycobacterium sp. isolates with EcoRI, BamHI, and XhoI restriction endonucleases, thus providing definitive evidence of their origin. Unidentified spheroplasts were isolated from an additional 12 patients with Crohn's disease, of which 7 of 10 seroagglutinated with antiserum prepared against the Mycobacterium sp. Spheroplasts were isolated from 16 of 26 (61%) patients with Crohn's disease but not from tissues of 13 patients with ulcerative colitis or 13 patients with other diseases of the bowel. These findings support the role of mycobacteria as etiologic agents in some cases of Crohn's disease.
Comparison of beta-glucuronidase-based substrate systems for identification of Escherichia coli
Authors: Edberg S C , Kontnick C M
Published: January 2020

Methods based on the measurement of beta-glucuronidase have been shown to be specific and inexpensive for the identification of Escherichia coli from bacterial colonies within 1 h. Recently, commercial systems incorporating beta-glucuronidase substrates were introduced. Rapid Identification Method E. coli (Austin Biological Laboratories, Curtin Matheson Scientific, Inc., Houston, Tex.) and Rapid Detect E. coli (Organon Teknika, Morris Plains, N.J.) are single-tube test combinations to simultaneously measure beta-glucuronidase (fluorescence at 366 nm), o-nitrophenyl-beta-D-galactopyranoside (yellow), and indole (red). To determine the accuracy and utility of these two systems, we used them to test 169 E. coli and 150 non-E. coli and compared them with conventional substrate tests. The Rapid Detect test was more efficient than the Rapid Identification Method in demonstrating beta-glucuronidase activity, but the commercial systems were equal to each other and to the conventional tests for o-nitrophenyl-beta-D-galactopyranoside and indole. There were no false reactions by either system.
In vitro exposure of preimplantation bovine embryos to vesicular stomatitis virus
Authors: Lauerman L H , Stringfellow D A , Sparling P H , Kaub L M
Published: January 2020

Vesicular stomatitis virus New Jersey serotype (VSV-NJ) adhered to 14 of 20 zonae pellucidae intact (ZP-I) bovine embryos exposed in vitro. The VSV-NJ-exposed ZP-I bovine embryos were washed by a single- or multiple-pipette procedure. The multiple-pipette washing procedure was more efficient in removing unattached virus than the single-pipette procedure, but neither washing procedure was effective in consistently removing attached virus from ZP-I embryos. The virus plaque assay with Vero-MARU cells was more sensitive than was the suckling mouse intracerebral inoculation procedure for detection of VSV-NJ from the sonic extracts of bovine embryos. A maximum of 15 infective VSV-NJ particles were detected adhering to one virus-exposed, washed ZP-I bovine embryo.
Immunofluorescence for detection of antibodies against human cytomegalovirus-induced membrane antigens
Authors: Middeldorp J M , Jongsma J , The T H
Published: January 2020

This paper describes an improved method for the in vitro detection of antibodies specifically directed against human cytomegalovirus (CMV)-induced membrane antigens present on the surface of CMV-infected fibroblasts (CMV-MA). Viable cells were found to be essential for specific visualization of CMV-MA staining. The addition of divalent cations (2.6 mM Ca2+ and 2.2 mM Mg2+) and glucose (180 mM) to the incubation and washing buffers improved the viability and morphology of the cells and increased the cell yield at the end of the assay. Clustering of antigen-antibody complexes on the surface of viable CMV-infected cells was prevented by low-temperature incubation (0 to 4 degrees C) rather than by the addition of agents which act on the metabolism of the cell. No interaction with the CMV-induced Fc receptor was observed at 0 degrees C with either human sera or murine monoclonal antibodies. The specificity of the CMV-MA reaction was confirmed by using monoclonal antibodies to CMV nuclear, cytoplasmic, and membrane-associated antigens. Furthermore, a microplate modification of the membrane fluorescence test is described which is suitable for multisample screening purposes. This method can be applied to the determination of anti-CMV-MA antibody titers in human sera and to the screening of hybridoma supernatants for the presence of antibodies with specificity for CMV-MA.
Concurrent Borrelia burgdorferi and Babesia microti infection in nymphal Ixodes dammini
Authors: Piesman J , Mather T N , Telford S R , Spielman A
Published: January 2020

Ixodes dammini nymphs were examined for evidence of concurrent infection with Borrelia burgdorferi and Babesia microti. A total of 19 nymphs (18.6%) from Nantucket Island were simultaneously infected, as were 24 nymphs (8.2%) from Naushon Island. These observations are consistent with a common reservoir host for both I. dammini-transmitted pathogens.
Isolation of Francisella tularensis from blood
Authors: Provenza J M , Klotz S A , Penn R L
Published: January 2020

The isolation of Francisella tularensis from blood culture is extremely rare; a review of the literature produced only five documented cases. However, over a recent 17-month period we saw four cases of tularemia in which the organism was isolated in blood culture. The clinical presentations of our patients and those reported previously were very similar. Most of the patients had a significant underlying disease and presented with the typhoidal form of tularemia. Furthermore, all our patients had sepsis, pleuropulmonary disease, and rhabdomyolysis. Tularemia agglutinins were not performed on admission serum specimens or were nondiagnostic. All the F. tularensis isolates from blood culture in our series and most of the recent documented cases were obtained in radiometric blood culture systems, which may be more sensitive than conventional systems for detecting this fastidious microorganism.
Modified method for fungal slide culture
Authors: Harris J L
Published: January 2020

A modified slide culture method which combines advantages found in several slide culture methods is described. A block of inoculated nutrient agar sandwiched between two sterile cover glasses is placed in a plastic petri dish containing water agar. After adequate growth has occurred, the slide culture is disassembled and mounted in a conventional manner.
Inhibition of pneumococcal autolysis in lysis-centrifugation blood culture
Authors: Lehtonen O P
Published: January 2020

The recovery of Streptococcus pneumoniae from the Isolator lysis-centrifugation blood culture has been low in many studies. The poor survival of pneumococci was not due to toxicity of the Isolator medium but to autolysis before plating. This autolysis was completely inhibited by adding 10 mM phosphorylcholine to the Isolator medium.
Endocarditis with Moraxella-like M-6 after cardiac catheterization
Authors: Perez R E
Published: January 2020

A patient developed bacteremia with CDC group M-6, a Moraxella-like bacterium, after a complicated heart catheterization. He was treated with tobramycin and ampicillin. The aortic valve was later replaced and did not show any signs of infection. The slow growth of M-6 can delay diagnosis and give misleading antibiotic susceptibility results. Penicillin is not always active against this organism.
Effect of medium composition on results of macrobroth dilution antifungal susceptibility testing of yeasts
Authors: Doern G V , Tubert T A , Chapin K , Rinaldi M G
Published: January 2020

A total of 62 different clinical yeast isolates were examined for susceptibility to four antifungal agents, amphotericin B, 5-fluorocytosine (5-FC), ketoconazole, and miconazole, using synthetic amino acid medium-fungi (SAAM-F), buffered yeast nitrogen broth (BYNB), Kimmig broth, casein-yeast-glucose broth (CYG), antibiotic medium 3-FDA (ANTI-3), and tryptic soy broth (TSB). A macrobroth dilution format was used with MICs determined after incubation for 24 and 48 h. All analyses were performed in duplicate. In general, MICs were more reproducible after 48 h of incubation. Furthermore, with certain medium-antifungal agent combinations, MICs determined after incubation for 48 h were significantly higher than those determined after 24 h. For instance, with 5-FC irrespective of the medium used, greater than 25% of all 48-h MICs were more than one twofold dilution higher than the corresponding MICs determined after incubation for 24 h. Similar observations were made with amphotericin B when tested with BYNB and CYG and with the imidazoles when tested in all of the media except CYG. The actual MICs obtained with the different antifungal agents were clearly influenced by the test medium used. The rank order of amphotericin B MICs according to test medium was as follows: BYNB greater than SAAM-F = Kimmig = CYG = ANTI-3 = TSB. With 5-FC, the following pattern was observed: Kimmig = ANTI-3 greater than SAAM-F = CYG = TSB greater than BYNB. For both imidazoles, ketoconazole and miconazole, the rank order of MICs according to test medium was BYNB = Kimmig = CYG = ANTI-3 = TSB greater than SAAM-F. The results of this investigation suggested that broth dilution susceptibility testing of yeasts is best performed with an incubation period of 48 h. Furthermore, medium composition can significantly influence the results of such testing.
Enzyme-linked immunosorbent assay for adherence of bacteria to animal cells
Authors: Ofek I , Courtney H S , Schifferli D M , Beachey E H
Published: January 2020

Epithelial cells scraped from human oral mucosa and from pig intestines were immobilized onto the flat bottom surfaces of microtiter plates to study the adherence of various bacterial species to host cells. Bacterial adherence was quantitated either by an enzyme-linked immunosorbent assay technique with specific antibacterial serum as the first antibody followed by peroxidase-conjugated second antibody or by using biotinylated bacteria and avidin-peroxidase as the detecting agent. Unlabeled Escherichia coli and purified E. coli 987P fimbriae inhibited the adherence of biotinylated E. coli to immobilized enterocytes. The adherence of a mannose-sensitive strain of E. coli to immobilized oral epithelial cells was inhibited by mannose derivatives. The adherence of fimbriated E. coli 987P to immobilized enterocytes was approximately four times higher than the adherence of a nonfimbriated variant of the same strain. The adherence of Streptococcus pyogenes to oral cells was detected in the range of 10 to 150 bacteria per cell and was inhibited by lipoteichoic acid and albumin. The data suggest that the putative receptors which bind bacteria on the immobilized cells retain a functional form similar to that of native cells in suspension. The proposed adherence assay is easy to perform, allows the detection of specific adherence of test bacteria, and provides objective quantitation of adherence with a sensitivity of 10 bacteria per cell. Most importantly, the assay allows the testing of many variables in the same day.
Enzyme-linked immunosorbent assay with major outer membrane proteins of Brucella melitensis to measure immune response to Brucella species
Authors: Hunter S B , Bibb W F , Shih C N , Kaufmann A F , Mitchell J R , McKinney R M
Published: January 2020

We developed an enzyme-linked immunosorbent assay (ELISA) system to measure human immunoglobulin G (IgG) and IgM response to the major outer membrane proteins of Brucella melitensis. The ELISA was more sensitive in detecting antibody than a standard microagglutination (MA) test with B. abortus antigen. Of 101 sera from persons with suspected brucellosis, 79 (78.2%) gave ELISA IgM titers greater than or equal to the B. abortus MA titer without 2-mercaptoethanol (2ME), which measures both IgM and IgG. Of the 101 sera, 97% gave ELISA IgG titers greater than or equal to the MA with 2ME titer. A total of 58 sera, drawn from 11 human patients from 1 to 29 weeks after onset of brucellosis, gave higher geometric mean titers for the ELISA IgG test than for the MA with 2ME test. These 58 sera also gave ELISA IgM geometric mean titers that were greater than or within one doubling dilution of the geometric mean titers of MA without 2ME. In addition to detecting antibody response to B. abortus, B. melitensis, and B. suis, the ELISA was sensitive to antibody response to human and canine infections with B. canis. The B. canis antibody response is not detected by the MA test with B. abortus antigen. The ELISA, with a standard preparation of major outer membrane proteins of B. melitensis as antigen, appears to be useful in measuring antibody response in humans to infections by all species of Brucella known to infect humans.
Simplified enzyme-linked immunosorbent assay for specific antibodies to respiratory syncytial virus
Authors: Vaur L , Agut H , Garbarg-Chenon A , Prud'Homme de Saint-Maur G , Nicolas J C , Bricout F
Published: January 2020

A simplified and reliable enzyme-linked immunosorbent assay (ELISA) was applied to the detection of serum antibodies against respiratory syncytial virus (RSV). RSV-infected cells were fixed and dried on 96-well microtiter plates and kept at 4 degrees C. The titers of reference sera were determined by endpoint dilution. A linear relation was found between the titers and the logarithm of absorbance values of sera diluted to 1:1,000 (r = 0.93, P less than 0.001). Measurement of RSV antibodies was done by using a single serum dilution (1:1,000) in conjunction with a standard curve. A strong correlation was found between complement fixation and ELISA results (r = 0.89, P less than 0.001). In addition, the ELISA method exhibited higher titers and a greater sensitivity than did complement fixation, although the applicability of the assay is limited with positive serum samples of low titer.
Microtiter broth dilution method for yeast susceptibility testing with validation by clinical outcome
Authors: Radetsky M , Wheeler R C , Roe M H , Todd J K
Published: January 2020

There is no ideal laboratory procedure or culture medium in current use for susceptibility testing of pathogenic yeasts. Six candidate growth media (RPMI 1640 with L-glutamine, yeast nitrogen base, Casamino Acids medium, Mueller-Hinton broth, Sabouraud dextrose broth, and minimum essential medium-Eagle salts) were screened by spectrophotometric absorbance for nucleic acid and protein. From these, two media were selected: a chemically defined growth medium (RPMI 1640 with L-glutamine) and a chemically complex medium (Casamino Acids). MICs of four antifungal agents (5-fluorocytosine, miconazole, ketoconazole, and amphotericin B) for 84 clinical isolates of various Candida species were then determined with both media in agar dilution and microtiter broth dilution systems. The resultant MICs were correlated with clinical outcome for those isolates obtained from patients treated with single antifungal agents, and susceptibility cut points were calculated. Derived MIC cut points for susceptibility were validated in a murine model of systemic candidiasis. RPMI 1640 with L-glutamine was found to have the lowest absorbance values for both nucleic acid and protein, while Casamino Acids medium was highest in both categories. We found that RPMI 1640 with L-glutamine was superior to Casamino Acids medium in the yield of MICs which correlated with actual clinical and animal outcome data. While there were no significant differences in MICs when RPMI 1640 medium was used, the microtiter broth dilution technique was superior to agar dilution in efficiency and ease of performance. We conclude that a microtiter broth system containing RPMI 1640 medium with L-glutamine is a simple, precise, and economical technique for susceptibility testing of pathogenic Candida species. We also suggest that the validation of susceptibility cut points with patient and animal outcome data make this microtiter broth system a preferential method for yeast susceptibility testing.
A 96-well epifluorescence assay for rapid assessment of compounds inhibitory to Candida spp
Authors: Hector R F , Braun P C
Published: January 2020

A rapid method for the screening of potential antifungal compounds was developed. A variety of compounds were tested against regenerating protoplasts of Candida spp. in a microtiter format. The degree of cell wall formation was assessed by staining with Cellufluor (Polysciences, Inc., Warrington, Pa.), a fluorochrome with known affinity for chitin, followed by determination of fluorescence by using a Dynatech Microfluor reader (Dynatech Laboratories, Inc., Alexandria, Va.). Compounds with known activity against the cell wall or cytoplasmic membrane of fungi inhibited wall synthesis in a concentration-dependent fashion. Treatment with 5-fluorocytosine, however, resulted in no inhibition. In general, protoplasts of C. albicans regenerated more quickly and were more sensitive to the compounds tested than protoplasts of C. tropicalis and C. parapsilosis. While the described method is not specific for a given class of antifungal agents, it may prove useful for testing large numbers of compounds quickly.
Staphylococcal resistance to aminoglycosides before and after introduction of amikacin in two teaching hospitals
Authors: Hammerberg O , Elder D , Richardson H , Landis S
Published: January 2020

A prospective study was conducted to determine the prevalence of aminoglycoside-resistant Staphylococcus aureus and coagulase-negative staphylococci before and after the introduction of amikacin as the sole aminoglycoside used in our burn unit, adult intensive care unit, and neonatal intensive care unit. Pharyngeal or endotracheal cultures, as well as superficial surveillance cultures, were collected weekly during the following four study periods: all units for 4 months before amikacin introduction, all units 4 to 8 months after, all units 12 to 13 months after, and the neonatal intensive care unit 30 months after. A total of 2,613 strains of coagulase-negative staphylococci and 316 strains of S. aureus were obtained from 916 patients. During the course of the study, amikacin-resistant coagulase-negative staphylococci increased from 0 to 22%, colonizing 43% of patients, whereas no amikacin-resistant S. aureus was detected. During the preamikacin survey, 68% of the coagulase-negative staphylococci and 12% of the S. aureus strains were resistant to tobramycin and gentamicin. This resistance did not decrease after amikacin was introduced. Initially, 83% of the aminoglycoside-resistant coagulase-negative staphylococci were resistant to both tobramycin and gentamicin. During the last surveillance this value dropped to 40%, and 48% of the strains had become resistant to all three aminoglycosides. Resistance to aminoglycosides, including amikacin, develops quickly in coagulase-negative staphylococci from clinical areas where these antimicrobial agents are widely used. However, aminoglycoside resistance in S. aureus is much less frequent.
Comparison of methods for isolation and titration of Crimean-Congo hemorrhagic fever virus
Authors: Shepherd A J , Swanepoel R , Leman P A , Shepherd S P
Published: January 2020

The fluorescence focus assay and the plaque assay in CER cells were compared with mouse inoculation for the isolation and titration of Crimean-Congo hemorrhagic fever virus. The fluorescence focus assay and the plaque assay were of similar sensitivity, but both produced 10- to 100-fold lower titers than did mouse inoculation. For specimens from 26 Crimean-Congo hemorrhagic fever patients in South Africa, virus was isolated from 20 by mouse inoculation and from only 11 by cell culturing. Although cell cultures were less sensitive for the isolation of virus from clinical specimens, they produced diagnostic results much more rapidly.
Evidence for production of an enterotoxin and cholera toxin cross-reactive factor by Aeromonas hydrophila
Authors: Chopra A K , Houston C W , Genaux C T , Dixon J D , Kurosky A
Published: January 2020

The enterotoxins produced by Aeromonas hydrophila were examined for biological activity by the rabbit ileal loop and suckling mouse assays, as well as by elongation of CHO cells. Antigenic evaluation of the culture filtrates from various isolates of A. hydrophila was performed by enzyme-linked immunosorbent assay with anti-cholera toxin and anti-Aeromonas enterotoxin. Heat stability data demonstrated the presence of a heat-labile cholera toxin cross-reactive factor and a heat stable non-cholera toxin cross-reactive enterotoxin. The biological activities of both enterotoxins were heat labile at 56 degrees C for 20 min.
Rapid detection of influenza virus by shell vial assay with monoclonal antibodies
Authors: Espy M J , Smith T F , Harmon M W , Kendal A P
Published: January 2020

Of 45 influenza virus strains (43 type A and 2 type B) detected in conventional tube cell cultures (average time, 4 days), 25 (56%) were detected by immunofluorescence in the shell vial assay 24 h postinoculation. The specific fluorescence produced should allow this procedure to be readily adapted by laboratories with various degrees of experience with immunofluorescence methodology.
Suitability of new chlamydia transport medium for transport of herpes simplex virus
Authors: Barnard D L , Farnes K , Richards D F , Croft G F , Johnson F B
Published: January 2020

A new chlamydia transport medium (ChlamydiaPort; Scott Laboratories, Inc., Fiskeville, R.I.) was evaluated for its suitability as a transport medium for herpes simplex virus (HSV). Two laboratory HSV strains (McIntyre and 333) and two clinical isolates (AO218 and AO301) were suspended in ChlamydiaPort, ViraPort (Scott Laboratories), and cell culture medium and maintained at 2 and 22 degrees C. Samples were tested at various time intervals to determine surviving virus. The range of half-lives of the HSV strains held at 2 degrees C in ChlamydiaPort medium was from 3.5 to 10 days, while virus stability was greater in ViraPort and less in cell culture medium. These HSV strains held at 22 degrees C in ChlamydiaPort had half-lives from 1.5 to 6 days, which were significantly greater than the half-lives of the viruses held in either tissue culture medium or ViraPort. Clinical specimens were tested for virus by using the Selecticult-HSV (Scott Laboratories) system to determine the performance of the transport medium under field conditions. Clinical specimens maintained up to 5 days at ambient temperatures in ChlamydiaPort medium appeared suitable for diagnostic testing without detectable loss of positive specimens. In addition, there was a significant decrease in the average time required for diagnosis when compared with a standard transport system, Virocult (Microdiagnostics, Cleveland, Ohio). These results show that HSV infections can be successfully diagnosed in distant virology laboratories by shipping specimens in ChlamydiaPort transport medium at ambient temperatures.
Evaluation of a proprietary broth medium for microdilution susceptibility testing of nutritionally fastidious bacteria
Authors: Barry A L , Cotton J L , Jones R N , Packer R R
Published: January 2020

For microdilution susceptibility tests with nutritionally fastidious microorganisms, a new clear broth medium developed at Micro-Media Systems, Inc., Potomac, Md., was evaluated in a three-laboratory collaborative study. Replicate tests were performed with 80 isolates (51 Streptococcus spp., 27 Haemophilus influenzae isolates, and 2 Neisseria meningitidis isolates) against 15 antimicrobial agents. In standard 100-microliters volumes, results of tests in the new broth medium were comparable to those in the reference medium (Mueller-Hinton broth with 2 to 3% lysed horse blood), but MICs were somewhat easier to read in the new broth medium. Results of similar tests in smaller panels, containing 40 microliters in each well, were less satisfactory; i.e., growth failures and poorly defined endpoints were more commonly encountered. With drugs other than erythromycin or clindamycin, the 40-microliters panels provided MICs which compared favorably with those obtained by standard reference methods.
Laboratory diagnosis of mycobacterial infections in patients with acquired immunodeficiency syndrome
Authors: Kiehn T E , Cammarata R
Published: January 2020

Disseminated mycobacterial infections are commonly seen in acquired immunodeficiency syndrome (AIDS) patients, and laboratory culture is the best method for diagnosing these infections. In addition to conventional agar media, we used BACTEC 12A (Johnston Laboratories, Inc., Towson, Md.) broth medium for culture. More isolates of Mycobacterium avium complex and Mycobacterium tuberculosis were recovered from 12A broth than from Lowenstein-Jensen or Middlebrook 7H11 agar. Also, the average detection time of these mycobacteria was the earliest with 12A broth. Stool examination has been helpful in diagnosing mycobacterial disease in AIDS patients, and in this study both acid-fast stain and culture of fecal material was necessary for efficient detection of mycobacteria. Another sensitive and practical method for detecting mycobacterial infections in patients with AIDS is the Isolator lysis-centrifugation system (Du Pont Co., Wilmington, Del.) which offers the advantage of quantitating the degree of mycobacteremia. Laboratories should be alerted to the possibility of mixed mycobacterial infection in patients with AIDS, and positive cultures should be repeatedly examined to detect coinfection with a slower-growing mycobacterium such as M. tuberculosis as well as M. avium complex.
Detection of immunoglobulin M in cerebrospinal fluid from syphilis patients by enzyme-linked immunosorbent assay
Authors: Lee J B , Farshy C E , Hunter E F , Hambie E A , Wobig G H , Larsen S A
Published: January 2020

Cerebrospinal fluid (CSF) samples were evaluated in an immunoglobulin M enzyme-linked immunosorbent assay (IgM ELISA) for syphilis with sonic extracts of Treponema pallidum coated on polystyrene plates. The ELISA procedure was reproducible, and T. pallidum antigens were stable., A total of 15 CSF samples from patients with neurosyphilis, 18 CSF samples from patients with syphilis, 12 CSF samples from patients treated for syphilis, and 494 CSF samples from patients with neurologic or other systemic diseases were tested. The IgM ELISA gave reactive results in all of six symptomatic and congenital neurosyphilitic patients and none of nine asymptomatic neurosyphilitic patients. Of 524 CSF samples from nonneurosyphilitic individuals, 513 were nonreactive, resulting in 98% test specificity. The IgM ELISA in CSF should prove to be useful for confirmation of symptomatic neurosyphilis.
Blinded, two-laboratory comparative analysis of Escherichia coli heat-stable enterotoxin production by using monoclonal antibody enzyme-linked immunosorbent assay, radioimmunoassay, suckling mouse assay, and gene probes
Authors: Thompson M R , Jordan R L , Luttrell M A , Brandwein H , Kaper J B , Levine M M , Giannella R A
Published: January 2020

Heat-stable enterotoxin (ST)-producing enterotoxigenic Escherichia coli (ETEC) can be identified by a variety of assays, including the suckling mouse assay (SMA), radioimmunoassay (RIA), polyclonal or monoclonal antibody enzyme-linked immunosorbent assay (ELISA), and DNA hybridization with STh and STp gene probes. To compare the sensitivity and reliability of these assays, 100 coded ETEC and non-ETEC isolates were blindly tested in two independent laboratories. SMA, RIA, and monoclonal ELISA were performed in Cincinnati, Ohio, while gene probe analysis was performed in Baltimore, Md. The method of storage of organisms had a profound effect on the stability of plasmids in certain strains. Hybridization experiments to determine the presence or absence of the enterotoxin gene showed that strains stored on Dorset egg medium at room temperature better retained their plasmids than strains stored frozen in skim milk. Forty-four of the 100 organisms obtained from the skim milk stock were found to produce STa in liquid culture by the RIA, SMA, and monoclonal ELISA (100% agreement). However, 50 of 54 of the strains stored on Dorset egg medium which were originally classified as STa+ or ST+ LT+ (positive for both heat-stable and heat-labile [LT] enterotoxins) were found to produce STa and retain the plasmid by each of these assays. Three additional strains were found which harbored the plasmid but did not elaborate STa by any of the assays (3% discrepancy). The monoclonal antibody ELISA appears to be highly reliable for determination of STa production by ETEC and can be easily scored visually even by untrained personnel. Furthermore, when this STa assay is coupled with a polyclonal antibody assay, it is possible to predict the genotype of STh- and STp-producing organisms.
Relevance of detection of immunoglobulin M antibody response in birds used for arbovirus surveillance
Authors: Calisher C H , Fremount H N , Vesely W L , el-Kafrawi A O , Mahmud M I
Published: January 2020

Young chickens were inoculated with 5,000 PFU of eastern equine encephalitis (EEE) virus and bled at intervals thereafter for determinations of hemagglutination-inhibiting (HI), neutralizing (N), immunoglobulin M (IgM), and IgG antibodies. HI, N, and IgM antibodies were first detected 4 days after infection, and IgG was detected 7 days after infection. All four antibodies persisted through day 90 after infection. HI, N, and IgM antibody titers remained elevated and were not cross-reactive with the related alphavirus western equine encephalitis (WEE) virus. IgG antibody titers also remained high, but heterologous reactivity to WEE virus increased with time after infection. Serum samples from sentinel chickens and wild birds infected in nature with EEE, WEE, or St. Louis encephalitis virus and submitted to this laboratory from state and local health departments were tested for IgM antibody by using anti-chicken IgM for capture and for IgG antibodies to the EEE and WEE viruses. There was essentially complete correlation between HI, N, and either IgM (indicating recent infections) or IgG (indicating more remote infections) antibody. We conclude that the IgM antibody capture enzyme immunoassay can be used as a specific and sensitive assay to replace the routinely used HI test for detecting antibody in sentinel chickens and in young, wild birds used for arbovirus surveillance. The test is rapid and relatively inexpensive and can be performed in essentially all adequately supplied laboratories.
Comparison of 15 laboratory and patient-derived strains of Mycobacterium avium for ability to infect and multiply in cultured human macrophages
Authors: Crowle A J , Tsang A Y , Vatter A E , May M H
Published: January 2020

Mycobacterium avium is a cause of nontuberculous chronic granulomatous infections which is attracting increased attention as a frequent opportunistic pathogen in acquired immunodeficiency syndrome. Some important aspects of its human pathogenicity were investigated by using cultured human macrophages infected with it. The uptake and replication of various strains of M. avium in the macrophages could be measured by CFU counts of the bacteria in samples of lysed, sonicated macrophages. Microscopic counts of acid-fast bacilli were not useful because the bacteria multiplying in the macrophages were usually not acid fast. Electron microscopy showed the intracellular bacilli to multiply by transverse fission, to be surrounded in individual vacuoles by a broad electronlucent zone, and to have thinner cell walls than extracellularly grown M. avium. Fifteen strains, including examples of serovars 1, 2, 4, 8, and 9, were studied for uptake and rate of replication in cultured macrophages from three normal subjects. The strains were isolates from patients with nontuberculous granulomatous infection, acquired immunodeficiency syndrome, or unrelated problems, or they were laboratory reference cultures. There were no differences among them in phagocytosis, but there were differences in intracellular replication. Laboratory strains tended to be avirulent, that is, they did not replicate in the macrophages. Patient isolates usually were virulent and could be compared for virulence by intracellular replication rates. Virulence correlated with flat, transparent bacterial colony morphology on nutrient agar but not with serovar or kind of patient from whom the bacteria were isolated. However, among strains of transparent colony morphology there were wide differences in virulence. A virulent bacilli generally produced domed, opalescent colonies on nutrient agar. A virulent bacilli predominated in populations of M. avium conditioned to growth in bacteriologic culture medium. Bacilli of virulent colony morphology predominated in populations passaged through cultured macrophages. The model described here presents a new approach to the investigation of the pathogenicity of M. avium for human subjects and may be more patient relevant than animal models.
Rapid double-sandwich enzyme-linked immunosorbent assay for detection of human immunoglobulin M anti-Toxoplasma gondii antibodies
Authors: Tomasi J P , Schlit A F , Stadtsbaeder S
Published: January 2020

The double-sandwich enzyme-linked immunosorbent assay has been compared with the indirect fluorescence assay for the detection of immunoglobulin M antibodies against Toxoplasma gondii in humans. Incubation times have been shortened, permitting the test to be completed within 2 h. The double-sandwich enzyme-linked immunosorbent assay is confirmed to be more sensitive and more specific than the immunofluorescence assay.
Disseminated cryptococcosis presenting as cellulitis with necrotizing vasculitis
Authors: Shrader S K , Watts J C , Dancik J A , Band J D
Published: January 2020

Patients with disseminated cryptococcosis infrequently present with cutaneous involvement. Skin lesions, when present, are usually multiple and polymorphous in appearance. Cellulitis caused by Cryptococcus neoformans is rare, and necrotizing vasculitis associated with cryptococcal vascular invasion has not to our knowledge been reported. We report here a case of disseminated cryptococcosis in a renal transplant recipient who had cellulitis and necrotizing vasculitis and in whom a diagnostic skin biopsy allowed for early therapy with cure and salvage of the renal allograft.
Detection of cytomegalovirus antibody by enzyme immunoassay and lack of evidence for an effect resulting from strain heterogeneity
Authors: Adler S P , McVoy M
Published: January 2020

A total of 259 serum samples from random blood donors were assayed by an enzyme immunoassay for antibody to cytomegalovirus (CMV) with antigens prepared from eight genetically unrelated clinical isolates of CMV and the laboratory-adapted strains AD169 and Towne. A total of 144 serum samples were reactive against all 10 strains, and 115 serum samples lacked immunoglobulin against all 10 strains. The results support the continued use of the AD169 strain of human CMV as the reference antigen for CMV serologic testing.
Salivary antibodies as a means of detecting human T cell lymphotropic virus type III/lymphadenopathy-associated virus infection
Authors: Archibald D W , Zon L I , Groopman J E , Allan J S , McLane M F , Essex M E
Published: January 2020

Of 45 individuals seropositive for human T cell lymphotropic virus type III/lymphadenopathy-associated virus, 45 were found to have detectable salivary antibodies to viral antigens by a radioimmunoprecipitation assay. The results also showed that a Western blot assay for salivary antibodies may be possible. The feasibility of a diagnostic test for human T cell lymphotropic virus type III/lymphadenopathy-associated virus not requiring venipuncture is discussed.
Rate of Campylobacter spp. isolation in three regions of Ontario, Canada, from 1978 to 1985
Authors: Thompson J S , Cahoon F E , Hodge D S
Published: January 2020

Isolation rates of Campylobacter spp. were analyzed for an 8-year period, 1978 through 1985. Three laboratories of the Ontario Ministry of Health examined 146,842 human feces samples for bacterial pathogens, including Campylobacter jejuni and Campylobacter coli. Campylobacter spp. were isolated from 5,580 specimens (3.8%), with monthly isolation rates ranging from 1.1 to 7.4%. The data showed a seasonal distribution of isolations, with peaks during the summer months (June to September). Most infections were in children, adolescents, and young adults. More males were infected than females; this finding was most pronounced in the age groups under 25 years. In Northern and Central Ontario, a strikingly higher incidence was observed among farm residents than among rural nonfarm or urban residents. Of 89 farm residents, 63 had consumed raw milk (61 bovine, 2 goat) within 72 h before becoming ill.
Rapid detection of gram-negative bacterial peritonitis by the Limulus amoebocyte lysate assay
Authors: Smalley D L , Baddour L M , Kraus A P
Published: January 2020

The chromogenic Limulus amoebocyte lysate test effectively detected 66 (100%) culture-proven gram-negative peritonitis cases among 185 continuous ambulatory peritoneal dialysis patients with clinical evidence of infectious peritonitis.
Clinical comparison of lysis-centrifugation and radiometric resin systems for blood culture
Authors: Brannon P , Kiehn T E
Published: January 2020

The Isolator 10 lysis-centrifugation blood culture system (E. I. du Pont de Nemours & Co., Inc., Wilmington, Del.) and the BACTEC 16B-17D radiometric resin system (Johnston Laboratories, Inc., Towson, Md.) both remove antimicrobial agents from the blood for culture. We compared these two systems for recovery of aerobic bacteria, facultatively anaerobic bacteria, and yeasts. A total of 5,000 blood cultures yielded 467 clinically significant isolates. Both systems recovered 350 (75%) organisms, 56 (12%) were detected by Isolator only, and 61 (13%) were detected by BACTEC resin bottles only. No group of organisms was isolated significantly more often from either system.
New serologically distinguishable type of coagulase-positive staphylococcus of canine origin
Authors: Live I
Published: January 2020

Of 150 coagulase-positive staphylococcal isolates from infections in dogs, 9 isolates with biochemical properties of human biotype were characteristically agglutinated by absorbed antiserum to staphylococcal strain 17, while only 110 of 141 isolates with biochemical properties of staphylococci of canine origin were agglutinated by absorbed antiserum to strain 61218. However, upon development of a new agglutinating serum, absorbed antiserum to strain 887, all but one of the remaining 31 isolates could be classified as being of canine biotype. Absorbed antiserum 887 should therefore aid in the comprehensive identification of staphylococci of canine origin in dogs, as well as in epidemiological studies of the interchange of staphylococci between canine pets and people.
Comparison of enzyme-linked immunosorbent assay and radioimmunoprecipitation test for detection of immunoglobulin A antibodies to Mycoplasma pneumoniae in nasal secretions
Authors: Naot Y , Lis E , Siman-Tov R , Brunner H
Published: January 2020

An immunoglobulin A (IgA) enzyme-linked immunosorbent assay was developed and compared with the radioimmunoprecipitation test in determinations of IgA antibodies to Mycoplasma pneumoniae. Of 45 nasal secretions obtained from infected volunteers, 42 (93.4%) were positive and 2 (4.4%) were negative in both tests. The IgA enzyme-linked immunosorbent assay is at least as sensitive as the IgA radioimmunoprecipitation test but is simpler and safer and should therefore be preferred.
Effect of age and preexisting antibody on serum antibody response of infants and children to the F and G glycoproteins during respiratory syncytial virus infection
Authors: Murphy B R , Alling D W , Snyder M H , Walsh E E , Prince G A , Chanock R M , Hemming V G , Rodriguez W J , Kim H W , Graham B S
Published: January 2020

The serum antibody response of 50 infants and children infected with respiratory syncytial virus (RSV) was determined by a glycoprotein-specific enzyme-linked immunosorbent assay, and the effects of age and preexisting antibody titer at the time of RSV infection on response to the G and F glycoproteins of RSV were examined. The immune response to the G and F glycoproteins was assessed with anti-human immunoglobulin A to permit measurement of the response of young infants in the presence of maternally derived immunoglobulin G. The findings suggested that age primarily affects the response to the F glycoprotein and that preexisting antibody titer affects the response to the G glycoprotein.
Etiological agent and primary source of infection in 42 cases of focal intracranial suppuration
Authors: Ariza J , Casanova A , Fernández Viladrich P , Liñares J , Pallarés R , Rufí G , Verdaguer R , Gudiol F
Published: January 2020

The microbiological findings for 42 patients with focal intracranial suppuration were analyzed and correlated with the different sources of primary infection. Streptococcus spp. were identified in focal intracranial suppuration of all origins except postcraniotomy. Microaerophilic streptococci were important in cases secondary to respiratory tract infection and in those of unknown origin. Streptococcus faecalis, Proteus spp., and Bacteroides fragilis were the organisms most commonly found in polymicrobial otogenic abscesses. Clostridium sp. was the main microorganism implicated in postcraniotomy suppurations.
Improved, computer-generated system for pyocin typing of Pseudomonas aeruginosa
Authors: Schable B , Olson D R , Smith P B
Published: January 2020

We applied numerical clustering algorithms to the selection of a new indicator strain set for the pyocin typing of Pseudomonas aeruginosa. The new indicator set is composed of selected indicator strains from the sets described in 1966 by Gillies and Govan (J. Pathol. Bacteriol. 91:339-345) and in 1974 by Jones, Zakanycz, Thomas, and Farmer (Appl. Microbiol. 27:400-406) and is designated the G-F set. This indicator set consists of 14 indicator strains which typed 99.5% of 114 test cultures, has a high degree of discrimination (10 patterns encompass 50% of the test strains), and provides 62.3% reproducibility of the same typing pattern in duplicate tests done on different days. The G-F set of indicator strains provides slightly higher percentages of typable cultures than either of the other two sets, has greater discriminatory capability, and is more reproducible than they are. We recommend that the G-F set of indicator strains be used instead of the two other sets for pyocin typing of P. aeruginosa. We also tested a recently described overlay procedure for pyocin testing of P. aeruginosa and found it to be superior to previous methods in that it is easier to perform, it provides answers in only 24 h instead of 48 h, and it can be used to type mucoid strains (which previous techniques could not readily do). Thus, the application of numerical clustering algorithms and use of a revised typing procedure have produced an improved system for pyocin typing of P. aeruginosa. Similar procedures may be applicable to other typing systems.