bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation of cerebrospinal fluid endotoxinlike activity with clinical and laboratory variables in gram-negative bacterial meningitis in children
Authors: Dwelle T L , Dunkle L M , Blair L
Published: January 2020

Detection of endotoxinlike activity in cerebrospinal fluid by Limulus amebocyte lysate gelation has been suggested as a useful technique for the diagnosis of gram-negative bacterial meningitis. We prospectively screened 1,503 cerebrospinal fluid specimens with a Limulus amebocyte lysate microassay. The limit of sensitivity of the assay was 0.01 ng/ml. All specimens that were positive for endotoxinlike activity were subjected to confirmatory retesting, after which 38 (86%) remained positive. Comparison with available culture results revealed that 33 of 38 specimens (86%) were culture positive; 3 of the 5 culture-negative specimens were from patients on therapy for gram-negative bacterial meningitis, and 1 was from a neonate. The overall specificity of confirmed positive tests was 99.5%, with a positive predictive value of 97.3%. There was one false-negative specimen, giving an overall sensitivity of 97.3% and a negative predictive value of 99.9%. Endotoxinlike activities of greater than or equal to 150 ng/ml correlated with present illness of less than 2 days' duration (P = 0.024), elevated cerebrospinal fluid protein (P less than 0.05), and seizures (P = 0.004); levels of greater than or equal to 3,000 ng/ml correlated with neutropenia (P = 0.032), and levels of greater than or equal to 3.2 X 10(6) ng/ml correlated with death (P = 0.001). We conclude that the Limulus amebocyte lysate microslide gelation test has prognostic value as a sensitive, specific, simple, inexpensive screening test for gram-negative bacterial meningitis.
Identification and characterization of Yersinia intermedia isolated from human feces
Authors: Punsalang A , Edinger R , Nolte F S
Published: January 2020

Since May 1983, our laboratory has, upon request, cultured stools for Yersinia spp. by using direct plating on cefsulodin-irgasan-novobiocin agar and a 3-week cold enrichment procedure. We isolated bacteria identified as Y. intermedia from six adult patients. All isolates were recovered only by the cold enrichment procedure and misidentified as Y. enterocolitica by the API 20E system (Analytab Products, Plainview, N.Y.). Final identification was made on the basis of results obtained with conventional tube biochemical tests. The isolates were tested for the following characteristics associated with virulence in Y. enterocolitica: lack of pyrazinamidase activity, autoagglutinability, presence of a 40- to 50-megadalton plasmid, production of heat-stable enterotoxin, and mouse lethality. All isolates tested had pyrazinamidase activity, and none were autoagglutinable. However, one isolate possessed a 40-megadalton plasmid. None produced enterotoxin or were lethal for mice. Review of the medical histories of the patients revealed that four of the six had diarrhea; however, none had disease typical of that caused by Y. enterocolitica. Our data confirmed the limited pathogenic potential of Y. intermedia and suggested that its isolation was without clinical significance in our patients. Conventional biochemical tests were required for reliable identification of Y. intermedia.
Effect of buffers on testing of Candida species susceptibility to flucytosine
Authors: MacKerrow S D , Merry J M , Hoeprich P D
Published: January 2020

Synthetic amino acid medium for fungi (SAAMF) is a totally defined, nutritionally adequate, macromolecule-free culture medium for fungi that is buffered with an organic weak acid-weak base pair: 2-(N-morpholino)-propanesulfonic acid (MOPS) and 2-amino-2-(hydroxymethyl)-1,3-propanediol (Tris). In 1984, it was reported that MOPS-Tris in SAAMF antagonized the activity of flucytosine against Candida albicans (D. L. Calhoun and J. N. Galgiani, Antimicrob. Agents Chemother. 26:364-367, 1984). Accordingly, we evaluated the buffering capacity of seven synthetic organic buffers and monobasic potassium phosphate, both singly and in pairs, over the pH range 7.4 to 6.0. Of these buffers, MOPS, BES [N,N-bis(2-hydroxyethyl)-2-aminomethanesulfonic acid], a BES-MOPS combination, and KH2PO4 provided the best buffering. Growth of C. albicans, in unbuffered SAAMF was equivalent overall to that in SAAMF containing buffers, singly or in pairs. Twelve strains of C. albicans and five strains of Candida lusitaniae were tested for susceptibility to flucytosine in SAAMF, with and without buffers. In the presence of Tris, the geometric mean MICs were 6.5- and 3.6-fold higher, respectively, for C. albicans and C. lusitaniae. We recommend replacing Tris with the nonantagonistic MOPS.
Serodiagnosis of human leptospirosis by counterimmunoelectrophoresis
Authors: Myers D M
Published: January 2020

The counterimmunoelectrophoresis (CIE) technique employing a soluble extract antigen was found useful in screening human sera for antileptospiral antibodies to multiple leptospiral serovars. The CIE test results with sera from patients with suspected cases of leptospirosis and sera from a control group compared favorably (97.9%) with those obtained by the microscopic agglutination test using a battery of live leptospiral antigens. CIE is easy to perform, is highly sensitive, uses an antigen which is very stable at room temperature, and permits the screening of many sera in a short period of time. The CIE technique appears to be ideally suited to a small laboratory where facilities may be too limited for examining sera by the microscopic agglutination test.
Immunological characteristics of malaria antibodies in two regions of Madagascar
Authors: Deloron P , Jaureguiberry G , Gaudebout C , Le Bras J , Savel J , Pocidalo J J
Published: January 2020

Antibodies directed against antigens of the asexual blood stages of Plasmodium falciparum were studied in the plasma of 29 individuals infected with P. falciparum and living in two areas of Madagascar. These plasma samples were investigated by four immunological methods: indirect fluorescence, immunoprecipitation of radiolabeled P. falciparum polypeptides, inhibition of the in vitro growth of P. falciparum, and double diffusion in a gelose plate. A multifactorial correspondence analysis of the results obtained for each sample revealed that the nature of several of the antibodies varied according to the age and place of residence of the subjects. In comparison with plasma samples from older individuals, specimens from young children had a higher immunofluorescence titer, immunoprecipitated several additional peptides (90, 110, and 118 kilodaltons), revealed more precipitation lines in the Ouchterlony plate technique, and did not inhibit the in vitro growth of P. falciparum to the same extent. Furthermore, as opposed to plasma samples from individuals living in the high central plateau, plasma samples from individuals living on the east coast of the island inhibited the penetration of erythrocytes by merozoites of one of the two studied P. falciparum strains and preferentially immunoprecipitated low-, rather than high-, molecular-weight peptides.
Acid-fast smear and culture of respiratory secretions, bone marrow, and stools as predictors of disseminated Mycobacterium avium complex infection
Authors: Poropatich C O , Labriola A M , Tuazon C U
Published: January 2020

Disseminated infection caused by Mycobacterium avium complex (MAC) is common in patients with acquired immune deficiency syndrome and is difficult to treat because of the high degree of resistance to antimycobacterial agents. Early diagnosis and treatment may prolong survival of patients with acquired immune deficiency syndrome and MAC infection. Twenty patients with disseminated MAC infection were evaluated for recovery of the organism from bone marrow, bronchial washings or sputum, and stools before the organism was isolated in blood culture. For 40 to 67% of patients, MAC was recovered from these specimens before it was isolated in blood culture.
Tissue homogenization with sterile reinforced polyethylene bags for quantitative culture of Candida albicans
Authors: Walsh T J , McEntee C , Dixon D M
Published: January 2020

A simple method of tissue homogenization with sterile reinforced polyethylene bags for quantitative fungal cultures was evaluated with mice infected with Candida albicans. This new method correlated well with standard methods (P less than or equal to 0.01) for quantifying viable fungus in homogenates of brain, kidney, spleen, liver, and lungs and may be applicable in clinical and experimental mycology laboratories.
Saksenaea vasiformis osteomyelitis
Authors: Pierce P F , Wood M B , Roberts G D , Fitzgerald R H , Robertson C , Edson R S
Published: January 2020

A 24-year-old man sustained a crush injury to the tibia, which subsequently became infected with Saksenaea vasiformis. He was treated with debridement and a free myocutaneous flap, but amputation was necessary because of mycotic osteomyelitis. S. vasiformis was recovered and identified on the basis of its characteristic morphology on cornmeal agar.
Hemagglutination by Pasteurella multocida of porcine origin
Authors: Fortin M , Jacques M
Published: January 2020

A total of 25 fresh isolates of Pasteurella multocida from pigs were tested for the ability to agglutinate erythrocytes of different origins. Of the 18 isolates from pigs with atrophic rhinitis (AR), 8 (44%) agglutinated human type O erythrocytes, whereas none of the 7 isolates from pigs without AR did so. Hemagglutination was mannose sensitive, and the activity was destroyed by heating and by trypsinization but was not affected by formaldehyde treatment or by homogenization of bacterial cells. The other 14 erythrocyte species tested, including human types A and B, were not agglutinated by P. multocida. The present study provides evidence that certain P. multocida isolates from pigs with AR possess a mannose-sensitive hemagglutinin.
Silica gel as transport medium for Corynebacterium diphtheriae under tropical conditions (Indonesia )
Authors: Kim-Farley R J , Soewarso T I , Rejeki S , Soeharto  , Karyadi A , Nurhayati S , Soeharto S
Published: January 2020

Silica gel was confirmed as a useful transport medium for Corynebacterium diphtheriae in the investigation of diphtheria cases in which there is no ready access to laboratory facilities.
Carumonam enhances reactivity of Escherichia coli with mono- and polyclonal antisera to rough Escherichia coli J5
Authors: Overbeek B P , Schellekens J F , Lippe W , Dekker B A , Verhoef J
Published: January 2020

Escherichia coli O111 reacts only slightly with antiserum to its rough mutant E. coli J5 in an enzyme-linked immunosorbent assay. When E. coli O111 was grown in the presence of sub-MICs of the monocyclic beta-lactam antibiotic carumonam, however, the enzyme-linked immunosorbent assay titer increased from 1,280 to 81,920. When the bacteria were grown in the presence of carumonam, the titer that was obtained with antiserum against E. coli O111 was not affected. This reaction was abolished after this antiserum was absorbed with E. coli J5 in the case of the carumonam-treated strain, whereas this absorption did not affect the reaction with E. coli O111. Thus, the O-antigenic side chain of E. coli O111 seems to be affected if this strain is cultured in the presence of carumonam. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed a relative loss of the O polysaccharide in E. coli O111 when this strain was grown in the presence of carumonam. Also, a much stronger reaction of the antibiotic-affected lipopolysaccharide with a monoclonal antibody against E. coli J5 lipopolysaccharide was shown in immunoblots. The results of this study indicate that there is a synergism between certain antibiotics and monoclonal antibodies, something that could have clinical implications.
Differential medium for mixed cultures of alpha-hemolytic streptococci from blood
Authors: Graham L , Meier F A , Dalton H P
Published: January 2020

Alpha-hemolytic streptococci (AHS) were isolated from blood cultures from 100 patients, and species were identified by the Ruoff and Kunz scheme. When isolates were inoculated onto sheep blood agar, all 100 cultures appeared to be pure, with identifications based on colonial morphology and Gram stain. When isolates were subcultured onto mitis salivarius agar (MSA), mixtures of two species of AHS were detected in 10 cultures from patients (10%). These mixed cultures would have been reported as pure cultures of Streptococcus milleri (six cultures), Streptococcus salivarius (three cultures), Streptococcus sanguis I (one culture), with identifications based on biochemical profiles. Cultures on MSA demonstrated S. milleri (six cultures), Streptococcus mitis (five cultures), S. salivarius (three cultures), S. sanguis I (one culture), and S. sanguis II (five cultures). The inability to separate AHS species by colony morphology on sheep blood agar demands that a differential medium such as MSA be routinely used for subculture. Failure to use such a medium may account for some of the confusing biochemical profiles associated with AHS species identification.
Assay of crystal violet binding for rapid identification of virulent plasmid-bearing clones of Yersinia enterocolitica
Authors: Bhaduri S , Conway L K , Lachica R V
Published: January 2020

A rapid, reliable, and simple method based on the binding of crystal violet (CV) is described for differentiating virulence-plasmid-bearing strains of Yersinia enterocolitica from their plasmidless derivatives. As with other plasmid-mediated properties of this organism, the binding of CV occurs at 37 degrees C but not at 25 degrees C. The CV-binding technique provides a simple and efficient means of screening Y. enterocolitica for virulence and for identifying individual plasmid-bearing colonies.
Protection between different serotypes of bovine rotavirus in gnotobiotic calves: specificity of serum antibody and coproantibody responses
Authors: Woode G N , Zheng S L , Rosen B I , Knight N , Gourley N E , Ramig R F
Published: January 2020

In a previous study, different U.S. isolates of bovine rotavirus were studied for their serotypes and cross-protective properties (G. N. Woode, N. E. Kelso, T. F. Simpson, S. K. Gaul, L. E. Evans, and L. Babiuk, J. Clin. Microbiol. 18:358-364, 1983). Three viruses belonging to two different serotype groups were used as vaccines in gnotobiotic calves, which were subsequently challenged with B641 or B223, representing the two bovine serotypes. In the present work, the experiments were repeated with more calves and the specificity of their antibody responses was measured and compared with the results of the protection studies. Protection between different serotypes occurred under both homologous and heterologous conditions but was not directly serotype dependent. B223 virus showed both homologous and heterologous protection against B223 and B641 challenge viruses. This was a one-way reaction, as B641 did not induce protection against B223. Neonatal calf diarrhea virus vaccine produced neither homologous (against B641) nor heterologous (against B223) protection. The plaque reduction neutralization titers of serum antibody and coproantibody did not predict a state of protection against the challenge virus. Calves vaccinated with neonatal calf diarrhea virus or B641 developed neutralizing antibodies to their respective heterologous challenge viruses but were not protected. After challenge, the boosted coproantibody plaque reduction neutralization response to the original vaccine virus was greater than that to the challenge virus.
Comparison of throat and nasopharyngeal swab specimens for culture diagnosis of Bordetella pertussis infection
Authors: Marcon M J , Hamoudi A C , Cannon H J , Hribar M M
Published: January 2020

During a 9-month period, we evaluated the relative sensitivity of throat and nasopharyngeal swab cultures for isolation of Bordetella pertussis. Of 38 pertussis cases, 36 (95%) had positive nasopharyngeal cultures, while only 16 of 36 (44%) had positive throat cultures. There were no cases of nasopharyngeal-negative, throat-positive cultures. The sensitivity of the direct fluorescent-antibody test was 70% when compared with culture.
Broviac catheter infection with Kluyvera cryocrescens: a case report
Authors: Wong V K
Published: January 2020

Kluyvera cryocrescens was isolated from a blood culture drawn from a patient with a Broviac catheter-related infection. K. cryocrescens has been considered an opportunistic pathogen but has not previously been associated with central venous catheter infections.
Septicemia caused by Sphingobacterium multivorum
Authors: Freney J , Hansen W , Ploton C , Meugnier H , Madier S , Bornstein N , Fleurette J
Published: January 2020

Sphingobacterium multivorum was isolated in pure culture from the blood of a man undergoing chemotherapy for a lymphoma. He responded to appropriate antibiotics and later showed a significant rise in specific serum antibodies. Carbon substrate assimilation tests and fatty acid analysis proved useful in identifying the organism precisely.
Comparative evaluation of a commercial enzyme-linked immunoassay and solid-phase immune electron microscopy for rotavirus detection in stool specimens
Authors: Gerna G , Sarasini A , Passarani N , Torsellini M , Parea M , Battaglia M
Published: January 2020

Using solid-phase immune electron microscopy (SPIEM) as a reference test, we examined 151 stool specimens from infants and young children with acute gastroenteritis for rotavirus detection by a one-step commercial enzyme-linked immunosorbent assay (ELISA) with labeled monoclonal antibody. Of the 83 samples determined to be positive for rotavirus by SPIEM, 82 were detected as positive by the monoclonal antibody ELISA (sensitivity, 98.7%), while 67 of the 68 specimens determined to be negative by SPIEM were correctly detected as negative by the ELISA (specificity, 98.5%). The diagnostic accuracy of the ELISA kit was 98.6%. Thus, the one-step monoclonal antibody ELISA, which can be completed in less than 90 min, appears to be highly suitable for the rapid and reliable detection of rotavirus in stools.
Economic comparison of enzyme immunoassay and virus isolation procedures for surveillance of arboviruses in mosquito populations
Authors: Hildreth S W , Beaty B J
Published: January 2020

Cost-effectiveness analysis of an enzyme immunoassay (EIA) for the surveillance of arboviruses was conducted. The EIA was compared with conventional virus isolation and serologic identification procedures (virus isolation procedures; VIP). Under most circumstances, EIA was more cost-effective than VIP. Costs for processing mosquito pools by VIP increased with the number of viruses included in the surveillance program and with the prevalence rate of each virus. In contrast to VIP, the prevalence rate did not affect costs for processing pools by EIA. In general, EIA was the most cost-effective procedure, followed by cell culture and mouse bioassays. In a 5-year cost-effectiveness analysis of a model surveillance program in which EIA and cell culture bioassays were used, the EIA again proved to be the most cost-effective assay procedure under most circumstances.
Bovine milk immunoglobulins for passive immunity to infantile rotavirus gastroenteritis
Authors: Brüssow H , Hilpert H , Walther I , Sidoti J , Mietens C , Bachmann P
Published: January 2020

Pregnant cows were successfully hyperimmunized with all four human rotavirus serotypes, resulting in a 100-fold increase in neutralizing milk antibody titers over those of controls. Milk antibodies were isolated batchwise from 1,000 kg of pooled milk for the first 10 lactation days, yielding 10 kg of freeze-dried milk immunoglobulin concentrate consisting of 50% bovine milk immunoglobulins. Milk immunoglobulin concentrate showed neutralizing activities against all four human rotavirus serotypes that were 100 times higher than those in pooled human milk samples and 10 times higher than those in a commercial pooled immunoglobulin preparation from pooled human blood serum. In vitro neutralization tests showed that milk immunoglobulin concentrate had powerful antiviral activity, even against very high doses of infectious rotaviruses. Because the technology of the milk immunoglobulin concentrate ensures that it is innocuous and can be used for oral application, it is proposed that milk immunoglobulin concentrate be used to induce passive immunity to infantile rotavirus gastroenteritis.
Anti-bovine antibody in human sera as a cause of nonspecificity in enzyme immunoassay
Authors: Dise T , Brunell P A
Published: January 2020

Much nonspecific activity in enzyme immunoassay is due to reactions between anti-bovine antibodies which are commonly present in human serum samples and residual calf serum in viral antigens. Calf serum is used in cultured cells which are used to produce viral antigens. Addition of bovine proteins to serum samples to be tested for viral antibodies reduces this activity.
Evidence for depressed humoral immunity to Pneumocystis carinii in homosexual males, commercial plasma donors, and patients with acquired immunodeficiency syndrome
Authors: Pifer L L , Niell H B , Langdon S B , Baltz S , Clark S T , Edwards C C , Woods D R
Published: January 2020

Heterosexual controls were found to have significantly higher titers of immunoglobulin G antibody to Pneumocystis carinii than did patients with the acquired immunodeficiency syndrome (AIDS) and P. carinii pneumonitis, human immunodeficiency virus (HIV) antibody-positive or -negative homosexual male "gay bar" patrons, and HIV antibody-positive or -negative commercial plasma donors. The T-helper/T-suppressor lymphocyte ratios of HIV antibody-negative homosexual male gay bar patrons were slightly depressed (mean = 1.31 +/- 0.54) compared with those of heterosexual controls (mean = 1.79 +/- 0.32). In addition to other recognized factors, preexisting humoral as well as cell-mediated immune deficits before infection with HIV may help to explain the prevalence of and morbidity and mortality associated with P. carinii pneumonitis in AIDS patients.
Genetic analysis of a human rotavirus that belongs to subgroup I but has an RNA pattern typical of subgroup II human rotaviruses
Authors: Nakagomi O , Nakagomi T , Hoshino Y , Flores J , Kapikian A Z
Published: January 2020

We have previously found (O. Nakagomi, T. Nakagomi, H. Oyamada, and T. Suto, J. Med. Virol. 17:29-34, 1985), during an epidemiological study in Japan, a novel human rotavirus that belongs to subgroup I but has a long RNA pattern typical of subgroup II human rotaviruses. From the stool specimen containing this virus, we successfully isolated in MA104 cells a rotavirus, designated AU-1, which possesses these novel characteristics. The possibility that strain AU-1 was a laboratory contaminant of an animal rotavirus previously adapted to tissue culture cells was ruled out, and the identity of the AU-1 strain was established. Genetic analysis by RNA-RNA hybridization revealed that the AU-1 strain is not a simple reassortant between subgroup I and II human rotaviruses but that it shares a high level of sequence homology only with the gene encoding VP7 (the major neutralization protein) of serotype 3 human rotaviruses. Weak homology of the genomic RNA segments was also observed between the AU-1 strain and animal rotavirus strains, including rhesus rotavirus strain RRV and bovine rotavirus strain NCDV. These results suggest that the AU-1 strain may be an animal rotavirus that infected a human.
In vitro activity of Ro 19-5247 (T-2525) and interpretive criteria for disk diffusion susceptibility testing
Authors: Beskid G , Fallat V , Siebelist J , Durkin J W , Lipschitz E R , McGarry D H
Published: January 2020

The activity of Ro 19-5247 (the active metabolite of the oral cephalosporin Ro 19-5248 [T-2588]) was compared with that of five orally active agents against a total of 331 bacterial strains. Ro 19-5247 was more active in vitro than amoxicillin, amoxicillin-clavulanate, cefaclor, cefuroxime, and cephalexin against members of the family Enterobacteriaceae. Amoxicillin-clavulanate and amoxicillin overall were more active than the other four agents against staphylococci. Ro 19-5247, amoxicillin-clavulanate, amoxicillin, and cefuroxime were equally active against nonenterococcal streptococci and more active than cefaclor and cephalexin. All six agents showed little or no activity against nonfermentative gram-negative bacteria. Against Streptococcus (Enterococcus) faecalis, only amoxicillin and amoxicillin-clavulanate were active. The interpretive criteria for in vitro susceptibility testing with 10- and 30-micrograms Ro 19-5247 disks were established by regression analysis to correlate the inhibitory zone sizes and MICs for the bacterial isolates. The suggested tentative zone size breakpoints for the 10-micrograms disk are as follows: susceptible, greater than or equal to 22 mm (MIC, less than or equal to 2 micrograms/ml); moderately susceptible, 20 to 21 mm (MIC, 4 micrograms/ml); and resistant, less than or equal to 19 mm (MIC, greater than or equal to 8 micrograms/ml).
DNA relatedness, taxonomy, and medical significance of Geotrichum capitatum
Authors: Guého E , de Hoog G S , Smith M T , Meyer S A
Published: January 2020

Among the clinical isolates hitherto identified as Geotrichum capitatum, two groups were defined from DNA-DNA reassociation experiments. This confirms the existence of two closely related, human-pathogenic Geotrichum species, namely, G. capitatum and G. clavatum. A third group of strains from cactus rots, though morphologically identical to G. capitatum, has a lower moles percent G + C of DNA. The three groups can be recognized by a combination of morphological and physiological characters.
Selective procedures for detecting femtomole quantities of tuberculostearic acid in serum and cerebrospinal fluid by frequency-pulsed electron capture gas-liquid chromatography
Authors: Brooks J B , Daneshvar M I , Fast D M , Good R C
Published: January 2020

Conditions are described for the detection of tuberculostearic acid (10-methyloctadecanoate; C18 X CH3) in cerebrospinal fluid and serum of patients with tuberculous meningitis. C18 X CH3 was found in both the cerebrospinal fluid and serum of patients with tuberculous meningitis at concentrations of 25 to 50 fmol (10(-15) mol). The necessary specificity and sensitivity for detection of C18 X CH3 were obtained by extraction under acid conditions with organic solvent, specific functional group esterification with trichloroethanol, cleanup with disposable reverse-phase sorption chromatography columns, analysis on high-resolution polar and nonpolar capillary columns, and detection by a frequency-pulsed electron capture detector. Use of an IBM 9000 computer equipped with CAP software significantly aided comparison between known C18 X CH3 standards and C18 X CH3 in clinical specimens. Scale expansion and attenuation changes were the major contributions obtained by use of the computer. The data indicate that detection of C18 X CH3 by frequency-pulsed electron capture gas-liquid chromatography may be a valuable aid for early detection of tuberculous meningitis.
Enzyme immunoassay using a novel recombinant polypeptide to detect human immunodeficiency virus env antibody
Authors: Thorn R M , Beltz G A , Hung C H , Fallis B F , Winkle S , Cheng K L , Marciani D J
Published: January 2020

A unique antigen, CBre3, has been synthesized from a genetically engineered clone to detect human immunodeficiency virus (HIV) env antibodies with high sensitivity and specificity. The antigen contains sequences derived from both envelope proteins of HIV, i.e., gp120 and gp41, and was purified free of Escherichia coli proteins detectable by Coomassie stain or immunoblotting with E. coli antiserum. The purified recombinant polypeptides were used as antigen in an enzyme immunoassay (EIA) to screen serum samples from healthy and HIV-infected individuals. The same samples were also tested by radioimmunoprecipitation (RIP) for gp120 and gp160 HIV antibodies. All samples containing gp120 and gp160 antibodies by RIP had CBre3 EIA values greater than 0.35 (n, 122; range, 0.37 to 2.1+; median, 1.65). All RIP HIV antibody-negative samples had CBre3 EIA values less than 0.25 (n, 140; mean, 0.052; standard deviation, 0.045; range, 0.00 to 0.22). The endpoint titer of a standard positive control serum was 1:10,000 by RIP and by CBre3 EIA. The assay was 100% accurate in three proficiency panels. It easily detected six samples from individuals whose infections were confirmed by culture; these samples were reactive only with p24 by Western blot. The samples also were positive for gp120 and gp160 antibodies by RIP. These data suggest that the CBre3 EIA can detect env antibodies as sensitively and specifically as RIP and with more sensitivity than Western blot.
Ultrafiltration to reject human interleukin-1-inducing substances derived from bacterial cultures
Authors: Dinarello C A , Lonnemann G , Maxwell R , Shaldon S
Published: January 2020

Interleukin-1 (IL-1), a polypeptide cytokine, is an important mediator of host responses to infection and injury. Picogram per milliliter concentrations of bacterial products (endo- or exotoxins) stimulate human monocytes to produce IL-1 in vitro. The design of this study was based on the clinical model of bacterial contamination of fluid intended to be directly injected into humans. Physiologic saline contaminated with bacterial toxins was passed through a hollow fiber ultrafilter, and the ultrafiltrates were tested for their ability to induce human IL-1 production. The ultrafiltrates were added directly to freshly obtained human blood mononuclear cells, and after 24 h of incubation the supernatant media were assayed for the presence of IL-1. The results indicate that the IL-1-inducing material(s) present in bacterial cultures of gram-negative organisms is rejected by a factor of 100 to 100,000 by molecular size exclusion and by absorption; rejection is sustained for at least 32 liters of fluid; the rejection of Limulus-reactive material by the ultrafilter is greater for purified endotoxin than for native endotoxins derived from live bacterial cultures; and nonendotoxin IL-1-inducing toxins (molecular weight, 24,000) from Staphylococcus aureus are not rejected or absorbed. These results demonstrate that there is a considerable margin of safety with the ultrafiltration method and that it can be applied to clinical situations.
Whole chromosomal DNA probes for rapid identification of Mycobacterium tuberculosis and Mycobacterium avium complex
Authors: Roberts M C , McMillan C , Coyle M B
Published: January 2020

Whole chromosomal DNA probes were used to identify clinical isolates of Mycobacterium tuberculosis, Mycobacterium avium complex, and Mycobacterium gordonae. The probe for M. tuberculosis was prepared from Mycobacterium bovis BCG, which has been shown to be closely related to M. tuberculosis. A probe for the M. avium complex was prepared from three strains representing each of the three DNA homology groups in the M. avium complex. The probes were used in dot blot assays to identify clinical isolates of mycobacteria. The dot blot test correctly identified 57 of the 61 (93%) cultures grown on solid media, and 100% of antibiotic-treated broth-grown cells were correctly identified. Identification by dot blot required a maximum of 48 h. When the probes were tested against 63 positive BACTEC (Johnston Laboratories, Inc., Towson, Md.) cultures of clinical specimens, 59% were correctly identified. However, of the 14 BACTEC cultures that had been treated with antibiotics before being lysed, 13 (93%) were correctly identified.
Commercial latex agglutination test for detection of Clostridium difficile-associated diarrhea
Authors: Kelly M T , Champagne S G , Sherlock C H , Noble M A , Freeman H J , Smith J A
Published: January 2020

A commercially available latex agglutination test for Clostridium difficile was compared with a cell culture cytotoxin assay and bacteriological culture for the laboratory diagnosis of C. difficile-associated diarrhea and colitis (CAD). Stool specimens from 626 patients were tested by the three methods, and specimens from 118 patients (19%) were positive by at least one of the methods. The results of the three tests agreed in 88% of the specimens tested, overall, but they agreed in only 34% of the 118 positive specimens. Ninety-three patients were evaluated to assess the significance of positive and negative results for each assay. Of 40 patients found to have CAD, 70% were positive by the cytotoxin assay, 78% were positive by the latex agglutination test, and 90% were culture positive. Of 53 patients who did not have CAD, 2% were positive by the cytotoxin assay, 8% were positive by the latex test, and 4% were culture positive. The detection of CAD was improved by using the tests in combination, and 97% of specimens positive by two or three methods were from patients who had CAD. Testing of multiple specimens from individual patients also increased the sensitivity of detection of CAD. The results suggest that the latex agglutination test may be useful for rapid diagnosis of CAD, especially in laboratories that lack cell culture facilities. However, the accuracy of CAD detection is improved when the latex test is used in combination with culture or the cytotoxin assay.
Effects of cycloheximide and puromycin on cytotoxic activity of Escherichia coli verocytotoxin (Shiga-like toxin)
Authors: Petric M , Karmali M A , Arbus G S , Roscoe M , Louie S , Cheung R
Published: January 2020

Verocytotoxin (VT)-producing Escherichia coli is closely associated with hemorrhagic colitis and hemolytic uremic syndrome. The diagnosis of this infection requires the demonstration of VT activity in fecal filtrates or the isolation of VT-producing E. coli from stools. To improve the sensitivity of the Vero cell assay for detecting VT, we investigated the interaction between this toxin and cycloheximide and puromycin, agents which, like VT and the related Shiga toxin, are protein synthesis inhibitors. Cycloheximide-treated cells were found to be about eightfold more sensitive to VT, this effect being most pronounced when the drug was added before the toxin. In contrast, puromycin treatment had an antagonistic effect in that it decreased the sensitivity of the cells to VT. In assays of VT in fecal filtrates, the addition of cycloheximide (at 4 to 8 micrograms/ml) increased the sensitivity without affecting the specificity of the assays. Likewise, the use of cycloheximide led to an increase in the sensitivity of the serum VT-neutralizing antibody test by a factor of over eightfold.
Classification and identification of Flavobacterium species by carbon source utilization
Authors: Rasoamananjara D , Korosec B , Monteil H
Published: January 2020

Carbon substrates used as the sole source of carbon and energy were tested for the classification and identification of species of Flavobacterium: Flavobacterium meningosepticum, F. breve, F. odoratum, F. multivorum, F. thalpophilum, and Flavobacterium sp. group IIb. Hierarchical classification and stepwise discriminant analysis revealed three F. meningosepticum, two F. breve, two F. odoratum, and two Flavobacterium sp. group IIb subgroups. Glucose, histidine, asparagine, tryptophan, maltose, citric acid, and glycine were selected as the most useful substrates to differentiate between the groups and subgroups.
Induction of procoagulant activity in human leukocytes with lipoglycans from mycoplasmas
Authors: Miragliotta G , Barone G , Monno R A , Fumarola D , Smith P F
Published: January 2020

Lipoglycans from mycoplasmas possess the ability to induce the elaboration of procoagulant activity. This represents a third endotoxic property for these polymers, in addition to the pyrogenicity and clotting of Limulus lysate reported previously. Lipoglycans from three species of Acholeplasma (A. axanthum, A. granularum, and A. oculi) stimulated the elaboration in vitro of procoagulant activity by human mononuclear cells to differing extents. Two serotypes, 3 and 4, of Ureaplasma urealyticum also exhibited this stimulatory activity. The activities of lipoglycans tested were, in decreasing order, A. oculi greater than U. urealyticum type 4 greater than A. axanthum greater than U. urealyticum type 3 greater than A. granularum.
Epidemic outbreak of Serratia marcescens infection in a cardiac surgery unit
Authors: Wilhelmi I , Bernaldo de Quirós J C , Romero-Vivas J , Duarte J , Rojo E , Bouza E
Published: January 2020

Between 2 February and 16 April 1985, an outbreak of Serratia marcescens infection involving 10 male patients occurred in a cardiac surgery unit. All the patients had surgical wound infection, five also had osteomyelitis (four sternal, one costal), and another had peritonitis secondary to peritoneal dialysis. Three patients had concomitant bacteremia. All Serratia strains isolated produced a cherry-red pigment, and all had the same biochemical and antibiotic susceptibility pattern. An intensive search for the origin of the outbreak was initially unsuccessful, and it proved impossible to isolate S. marcescens from cultures of numerous samples taken from hospital personnel and from the environment. The fact that all patients were male and had been shaved for surgery by the same team of barbers led us to investigate the shaving procedures. We finally isolated a strain of pigmented S. marcescens, corresponding to that involved in the outbreak, from samples taken from the hands and equipment of the barbers. After suitable action had been taken, the epidemic terminated.
Simultaneous production of rhamnolipids, 2-alkyl-4-hydroxyquinolines, and phenazines by clinical isolates of Pseudomonas aeruginosa
Authors: Smeal B C , Bender L , Jungkind D L , Hastie A T
Published: January 2020

Of 72 clinical isolates of Pseudomonas aeruginosa examined for simultaneous production of secondary metabolites, 86% produced 2-alkyl-4-hydroxyquinolines, 75% produced rhamnolipids, and 58% produced phenazines, including pyocyanin. Whereas isolates producing two or one constituted smaller groups, 39% released all three metabolites. Metabolite production did not appear to influence site of infection.
Saliva as a source of feline leukemia virus antigen for diagnosis of disease
Authors: Lewis M G , Wright K A , Lafrado L J , Shanker P J , Palumbo N E , Lemoine E D , Olsen R G
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) for detection of feline leukemia virus (FeLV) p27 in saliva was tested for its accuracy and sensitivity in diagnosing FeLV infections. Saliva and serum samples from 564 clinical cases were tested with a 99.2% specificity. The overall accuracy of the saliva ELISA reactive to the serum ELISA was 97.9%. Experimentally, the ELISA saliva was the least sensitive in diagnosing early FeLV infections. However, the overall accuracy, ease of use, and simplicity of the test support its use as a screening procedure in clinical practice.
Evaluation of three types of cell culture for recovery of adenovirus from clinical specimens
Authors: Krisher K K , Menegus M A
Published: January 2020

The performance characteristics of HEK, HDF, and MK cells for adenovirus isolation were examined for eye and respiratory tract specimens. HEK cells were superior to HDF and MK cells in terms of both speed of virus detection and sensitivity.
Isolation of Stomatococcus mucilaginosus from drug user with endocarditis
Authors: Coudron P E , Markowitz S M , Mohanty L B , Schatzki P F , Payne J M
Published: January 2020

Stomatococcus mucilaginosus was isolated from the blood of a patient with endocarditis and a past history of drug abuse and aortic valve replacement. At autopsy, Gram stain of the aortic valve revealed gram-positive cocci. Our isolate was atypical for S. mucilaginosus in that colonies were nonmucoid and nonadherent to agar surfaces. Cellular capsules were demonstrated by light and electron microscopy. Phenotypic characteristics identified by conventional methods as well as profile numbers obtained by using two commercial identification systems for staphylococci, the API Staph-Ident and the dms Staph Trac, are presented. Practical tests that differentiate S. mucilaginosus from the genera Micrococcus and Staphylococcus include growth on nutrient agar containing salt and lysostaphin susceptibility. Additional tests that helped differentiate our isolate from group D streptococci included hydrolysis of L-pyrrolidonyl-beta-naphthylamide and streptococcal serogrouping.
Controlled evaluation of modified radiometric blood culture medium supplemented with gelatin for detection of bacteremia and fungemia
Authors: Weinstein M P , Reller L B , Mirrett S , Reimer L G , Wang W L , Stratton C W
Published: January 2020

Although the addition of 1.2% gelatin to broth blood culture media containing sodium polyanetholesulfonate has been shown to enhance detection of certain bacteria, including Neisseria meningitidis, N. gonorrhoeae, Peptostreptococcus anaerobius, and Gardnerella vaginalis, the effect of such supplementation on the detection of other microorganisms causing bacteremia and fungemia is not known. Therefore, we studied BACTEC 6B medium with and without gelatin in 6,833 paired comparisons to examine the effects of supplementation on both the yield and the speed of detection of sepsis. More aerobic and facultative bacteria grew in the 6B than in the 6B-gelatin medium (P less than 0.001), especially staphylococci (P less than 0.01), Escherichia coli (P less than 0.01), other members of the family Enterobacteriaceae (P less than 0.05), and Acinetobacter spp. (P less than 0.05). When microorganisms grew in both bottles, they did so earlier in 6B than in 6B-gelatin (P less than 0.001). We conclude that the 6B medium in its present formulation is superior to 6B medium supplemented with 1.2% gelatin.
Detection of beta-lactamase activity among clinical isolates of Branhamella catarrhalis with six different beta-lactamase assays
Authors: Doern G V , Tubert T A
Published: January 2020

A total of 74 different clinical isolates of Branhamella catarrhalis were examined for their ability to produce beta-lactamase by six different beta-lactamase assays. These included a conventional tube and disk test, in which the chromogenic cephalosporin nitrocefin was used as a substrate; a disk procedure, in which pyridinium-2-azo-p-dimethylanaline cephalosporin was used as a substrate; broth and disk acidometric methods; and a conventional tube iodometric assay. A total of 58 of the study isolates produced beta-lactamase. In all cases, positive results were obtained with the nitrocefin tube and disk assays after 1 min. With the pyridinium-2-azo-p-dimethylanaline cephalosporin disk test, 57 of the 58 beta-lactamase-producing strains yielded a positive reaction in 1 min; the remaining strain was positive after 10 min. None of the beta-lactamase-producing strains produced positive reactions by either the broth or disk acidometric methods after 1 min. With the broth test, 10 min was required for positive test results for 42 strains; 30 min was necessary for 16 strains. By the disk acidometric procedure, all 58 strains were positive after 10 min. Of 58 beta-lactamase-producing strains, 30 were positive by the iodometric assay after 1 min, 13 strains required 10 min, and 4 strains were detected as being beta-lactamase positive only after 30 min. One beta-lactamase-producing strain remained negative by the iodometric method. Among the 16 strains of B. catarrhalis that lacked beta-lactamase that were examined in this study, no false-positive results were obtained by any of the six assays.
Simplified acetylcysteine-alkali digestion-decontamination procedure for isolation of mycobacteria from clinical specimens
Authors: Ratnam S , Stead F A , Howes M
Published: January 2020

During our attempts to reevaluate and improve mycobacteriology laboratory procedures, we found that isolation of mycobacteria from undecontaminated specimens through the use of selective media was unrewarding and that specimen decontamination was an essential step. A reevaluation of the N-acetyl-L-cysteine-sodium hydroxide (NALC-NaOH) decontamination procedure (G. P. Kubica, W. E. Dye, M. L. Cohn, and G. Middlebrook, Am. Rev. Respir. Dis. 87:775-779, 1963) indicated that this method could be simplified and shortened without affecting the isolation rate or growth and without increasing the contamination rate. The modified NALC-NaOH procedure effectively combines the decontamination step with the concentration step: specimens are mixed with the NALC-NaOH solution on a Vortex mixer and, without any waiting or addition of buffer or water to the digested specimens, centrifuged at 3,000 X g for 15 min, and the sediment is suspended in phosphate buffer (pH 5.3). The modified method is simpler, faster, and safer than the original procedure, and the reduced manipulation is also likely to minimize the chance for cross-contamination in sequential specimen processing. The total alkali exposure time in the modified NALC-NaOH method should be kept to a minimum; if necessary or feasible, the concentration of NaOH in the digestion solution may be reduced from the usual strength of 2% to about 1.5% to compensate for the longer alkali exposure time in the modified method to maintain the isolation rate or to improve it.
Rapid identification of Mycobacterium avium complex in culture using DNA probes
Authors: Drake T A , Hindler J A , Berlin O G , Bruckner D A
Published: January 2020

A commercial DNA probe procedure for identification of Mycobacterium avium complex isolates was evaluated for accuracy and applicability for use in the clinical laboratory. The test (Gen-Probe Rapid Diagnostic System for Mycobacterium Avium Complex; Gen-Probe Corp., San Diego, Calif.) uses hybridization in solution of two 125I-labeled cDNA probes. One probe is complementary to rRNA from M. avium, and the other is complementary to rRNA from M. intracellulare. Results are expressed as absolute percent hybridization, with values greater than or equal to 10% considered positive. The procedure accurately identified all 134 M. avium complex isolates and concomitantly identified them to species level. There were no false-positives with 66 other mycobacteria, including 22 M. tuberculosis and 18 M. kansasii isolates, or with 8 Nocardia isolates. The mean percent hybridization (+/- the standard deviation) of M. avium probe-positive isolates (94 isolates) was 48.0 +/- 9.9 (range, 11.5 to 72.7); for M. intracellulare (40 isolates), it was 45.7 +/- 8.8 (range, 22.7 to 60.7). Among the 74 non-M. avium complex isolates, the percent hybridization range was 1.0 to 4.2, except for a single value of 9.7 which was less than 5 when the test was repeated. Four M. avium complex isolates reacted positively with both probes on initial testing, and three were confirmed. On repeat testing of subcultures, each reacted with only one probe, suggesting the presence of a mixed culture. The procedure can be completed in as little as 2 h and could easily be performed in most clinical laboratories.