bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of blind passage and multiple sampling on recovery of Chlamydia trachomatis from urogenital specimens
Authors: Jones R B , Katz B P , van der Pol B , Caine V A , Batteiger B E , Newhall W J
Published: January 2020

Detection of chlamydial infections depends on the sensitivity of the techniques used. Variables include the number of body sites sampled, the number of samples obtained, and the number of passages in tissue culture. To assess these factors, microdilution plate cultures with a single blind passage were performed on specimens from 10,291 men and women attending a sexually transmitted disease clinic. Overall, 21% of the men and 30% of the women were culture positive. However, 18% of endocervical, 28% of female urethral, and 29% of male urethral cultures that were positive became so only after a single passage. Of culture-positive women, 23% were positive at the urethra only. Pooled urethral and endocervical specimens were positive more often than an endocervical specimen alone but less often than separately cultured endocervical and urethral specimens. A total of 221 specimens from 92 men and 66 women were subjected to five serial blind passages. Of 83 positive specimens, 29 (35%) were positive only after two or more passages. A total of 37 (46%) women were culture-positive, but only 12 (33%) of those who were positive and had an endocervical culture would have been detected by a single endocervical culture that was not passaged. The sensitivity of chlamydial culture is substantially less than 100% but can be improved by culturing samples from both the urethra and endocervix in women and by serial passage in tissue culture.
Antimicrobial activity of cefmetazole (CS-1170) and recommendations for susceptibility testing by disk diffusion, dilution, and anaerobic methods
Authors: Jones R N , Barry A L , Fuchs P C , Thornsberry C
Published: January 2020

Cefmetazole, formerly CS-1170, was found to have antimicrobial activity slightly superior to that of cefoxitin but a clinically usable antimicrobial spectrum that should be considered identical to that of cefoxitin. Disk diffusion and dilution test methods with cefmetazole correlated highly (r, greater than or equal to 0.95) with cefoxitin results. The recommended 30-micrograms cefmetazole disk interpretive breakpoints for susceptibility and resistance were greater than or equal to 18 mm (MIC, less than or equal to 8.0 micrograms/ml) and less than or equal to 14 mm (MIC, greater than or equal to 32 micrograms/ml), respectively. Cefmetazole and cefoxitin should be considered to be in the same antimicrobial spectrum class, requiring separate testing for other cephalosporins such as cephalothin, cefamandole, cefuroxime, and cefotetan. Recommended interpretive criteria performed well for fastidious organisms (Haemophilus influenzae, Neisseria meningitidis, and Branhamella catarrhalis) and for broth microdilution tests with anaerobes. Cefmetazole and cefoxitin broth disk elution tests for anaerobic bacteria produced higher rates of false susceptibility results.
Microbiological and biochemical characterization of spirochetes isolated from the feces of homosexual males
Authors: Jones M J , Miller J N , George W L
Published: January 2020

Spirochetes were isolated from the feces of 11 homosexual males who had diarrhea. The anaerobic organisms were isolated from a selective medium that consisted of Trypticase soy agar supplemented with either 5% horse or human blood, 400 micrograms of spectinomycin per ml, and 5 micrograms of polymyxin B per ml. Nonselective media that permitted good growth of these fastidious organisms were developed, and selected biochemical tests were performed. The tests included carbohydrate utilization, detection of certain enzymes, and determination of volatile fatty-acid end products of metabolism. Two growth patterns were noted on solid media, a haze of growth and production of small colonies. Based on the results of biochemical tests, patterns of preformed enzymes, and volatile fatty-acid production, we believe that the 11 isolates represent a heterogeneous group of spirochetes. The data suggest that the human colon may harbor unique strains of cultivable spirochetes; additional study of the taxonomy of the organisms and assessment of their virulence for humans are needed.
Physical and chemical characterization of a Giardia lamblia-specific antigen useful in the coprodiagnosis of giardiasis
Authors: Rosoff J D , Stibbs H H
Published: January 2020

We recently reported the isolation and identification of a Giardia lamblia-specific antigen (GSA 65) that is shed in the stool of giardiasis patients. In the present study, this antigen was affinity purified from sonic extracts of axenically cultured G. lamblia trophozoites and characterized to better understand its biological function and its potential usefulness in the design of coprodiagnostic assays for giardiasis. GSA 65 was resistant to proteolytic digestion with trypsin, chymotrypsin, and protease but was sensitive to treatment with NaIO4 as assessed by Western blotting. This antigen was also stable during prolonged storage at 4 and -20 degrees C in 10% Formalin or distilled H2O as assessed by counterimmunoelectrophoresis. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing gel banding patterns, in conjunction with protein and carbohydrate assays and lectin binding studies, confirmed that this antigen is a highly glycosylated glycoprotein. The resistance of GSA 65 to proteolytic degradation, together with previous immunofluorescence data that indicate the antigen is an integral part of the G. lamblia cyst wall, suggests that this molecule may play a role in maintaining the integrity of the cyst in vivo. The ability of GSA 65 to maintain its antigenic structure under a wide variety of conditions makes it an ideal antigen around which to design sensitive immunodiagnostic assays for giardiasis.
Comparison of Rapid NFT system and conventional methods for identification of nonsaccharolytic gram-negative bacteria
Authors: Martin R , Siavoshi F , McDougal D L
Published: January 2020

This study examined the Rapid NFT system (Analytab Products, Plainview, N.Y.) to determine its ability to accurately identify 229 clinical isolates of mostly nonsaccharolytic gram-negative rods. Identifications were classified by the following scheme: correct (corresponding to excellent, very good, good, or acceptable identification as listed in the code book); low discrimination (correct identification among a range of listed possibilities, with additional tests necessary for accurate identification); incorrect. Correct identification was considered correct to species and subspecies for all organisms except Alcaligenes faecalis and "Alcaligenes odorans"; "A. faecalis/odorans" was considered a correct response. By using these criteria, 71.6% of the strains were correctly identified, 17.9% were identified with low discrimination, and 10.5% were incorrectly identified. When consideration was made for incorrect identification resulting from taxonomic problems (e.g., Alcaligenes and Moraxella spp.), incorrect identifications fell to 5.2%. The Rapid NFT system was truly rapid and was easy to use and interpret. Its use of carbon substrate assimilation enables it to provide more accurate identification of medically important nonsaccharolytic bacteria than do other commercially available systems.
Type specificity of complement-fixing antibody against herpes simplex virus type 2 AG-4 early antigen in patients with asymptomatic infection
Authors: Sherlock C H , Ashley R L , Shurtleff M L , Mack K D , Corey L
Published: January 2020

We evaluated the type specificity of complement-fixing (CF) antibody against the AG-4 early antigen of herpes simplex virus (HSV) type 2 (HSV-2) by comparing a commercial AG-4 CF kit (Simplex-2; Gene Link Australia, Inc., Princeton, N.J.) with quantal microneutralization (MN) and absorption-Western blotting in testing sera from patients with and without a history of genital herpes. Sera characterized as HSV type 1 (HSV-1) or HSV-2 positive or negative by MN were selected and tested by CF, and those with discordant results were further analyzed for specific antibodies by absorption with HSV-1 or HSV-2 antigen and Western blotting with heterologous HSV proteins. A total of 34 of 42 (81%) sera HSV-2 positive by MN, 19 of 43 (44%) sera HSV-1 positive by MN, and 0 of 19 sera negative by MN were positive by CF. Absorption-Western blotting showed that 12 of 18 (67%) sera HSV-1 positive by MN but positive by CF had no HSV-2-specific antibody and that all 7 sera HSV-2 positive by MN but negative by CF had HSV-2-specific antibody. When MN and absorption-Western blotting data were combined to analyze patients with no history of genital herpes, 7 of 19 (37%) with no HSV-2-specific antibody were positive by CF, and 7 of 27 (26%) with HSV-2-specific antibody were negative by CF. The positive and negative predictive values for the CF test were 78 and 75%, respectively, in this group. The presence of antibody to the HSV AG-4 antigen does not discriminate sufficiently between HSV-1- and HSV-2-infected patients to be of value in predicting HSV-2 infection in the absence of symptomatic disease.
Rapid differentiation of streptococci isolated from cows with mastitis
Authors: Schaufuss P , Lämmler C , Blobel H
Published: January 2020

The demonstration of some species-specific streptococcal enzymes with 4-methylumbelliferyl-conjugated beta-D-glucuronide, N-acetyl-beta-D-glucosaminide, and beta-D-mannoside and agglutination with the lectin from Dolichos biflorus allowed rapid tentative identification of streptococci isolated from cows with mastitis.
Acid-fast bacilli in sputum: a case of Legionella micdadei pneumonia
Authors: Hilton E , Freedman R A , Cintron F , Isenberg H D , Singer C
Published: January 2020

Legionella micdadei has been implicated as a cause of nosocomial pneumonia. There are no reports of L. micdadei pneumonia diagnosed by acid-fast stain of expectorated sputum. We report a case of L. micdadei pneumonia in which expectorated sputum harbored acid-fast bacteria that reacted specifically with fluorescent antiserum to L. micdadei, confirmed by culture. In a patient at risk for nosocomial infection, the differential diagnosis of a positive sputum stain for acid-fast bacilli should include L. micdadei in addition to mycobacteria. Therapy for L. micdadei infection should be considered pending confirmation of the diagnosis.
Reliability of latex agglutination tests for identification of Staphylococcus aureus resistant to oxacillin
Authors: Punsalang A , Migneault P C , Nolte F S
Published: January 2020

Commercial latex agglutination tests (LATs) for the simultaneous detection of clumping factor and protein A are gaining increased acceptance as a means of identifying Staphylococcus aureus. We evaluated two LATs (Accu-Staph; Carr-Scarborough, Decatur, Ga.; Staphaurex; Wellcome, Dartford, England) with particular emphasis on their ability to correctly identify oxacillin-resistant S. aureus. We tested 59 oxacillin-resistant S. aureus, 136 oxacillin-susceptible S. aureus, and 92 coagulase-negative staphylococcal strains with the two LATs and with thermonuclease, slide clumping factor, tube coagulase, and protein A hemagglutination tests. Clumping factor and protein A were present in 96.9 and 82.1% of our S. aureus strains, respectively. Accu-Staph correctly identified 92.8% and Staphaurex correctly identified 91.3% of S. aureus strains. No significant difference in LAT positivity rates, presence of clumping factor, or presence of protein A was found between oxacillin-resistant and -susceptible S. aureus. Overall, there were 31 false-negative LATs for 20 S. aureus strains, 14 with Accu-Staph and 17 with Staphaurex. Ninety-five percent of these strains possessed either clumping factor or protein A or both when these factors were determined independently. There were five false-positive LATs for four strains of coagulase-negative staphylococci (three Staphylococcus epidermidis and one Staphylococcus warneri), four with Accu-Staph and one with Staphaurex. Clumping factor was present in one S. warneri strain. Thus, the specificities of Accu-Staph, Staphaurex, and the clumping factor test were 95.6, 98.9, and 98.9%, respectively. Our results indicated that LATs identify oxacillin-resistant and -susceptible S. aureus equally well; however, they offer no greater sensitivity or specificity than the clumping factor test for identification of S. aureus.
Detection of poliovirus antigen by enzyme immunoassay
Authors: Ukkonen P , Huovilainen A , Hovi T
Published: January 2020

A solid-phase enzyme immunoassay (EIA) was developed for the detection of poliovirus antigen. Rabbit and guinea pig antisera for the assay were raised against purified poliovirus type 3/Fin (strain 3/Fin/K) isolated from a fecal specimen from a meningitis patient during an outbreak of poliomyelitis in Finland in 1984. The EIA was highly specific for poliovirus type 3, and it was about 30 times more sensitive for strain 3/Fin/K than for strain 3/Saukett used in the inactivated poliovirus vaccine. The sensitivity of the EIA was 2 to 5 ng of purified strain 3/Fin/K per ml, whereas disrupted viruses and soluble viral proteins were almost undetectable by the assay. Only 5 of 51 (10%) stool specimens containing poliovirus type 3/Fin detected by virus isolation were positive by the EIA. Quantitation by the EIA, using purified poliovirus 3/Fin/K as a standard, revealed that concentrations of poliovirus type 3 in undiluted fecal specimens of patients with natural poliovirus infection were only 50 ng/ml or less. In conclusion, owing to the small amount of poliovirus in feces, the EIA is not suitable for the diagnosis of poliovirus infections directly from clinical specimens, but it can be used to detect, type, and quantitate poliovirus antigen in infected cells.
Comparison of in situ hybridization and immunologic staining with cytopathology for detection and identification of herpes simplex virus infection in cultured cells
Authors: Landry M L , Zibello T A , Hsiung G D
Published: January 2020

Two recently developed sensitive techniques, in situ hybridization with a biotinylated cloned DNA probe and an avidin-biotin complex immunoperoxidase assay, were compared with the appearance of cytopathic changes for the early detection of herpes simplex virus infection in cell culture. By using commercially made reagents, these detection methods were evaluated in two different cell culture systems inoculated with both high- and low-input multiplicity of virus. The results revealed that both viral antigen and viral DNA detection methods could shorten the time to diagnosis of herpes simplex virus infection in cell culture; however, these methods were most useful in specimens containing low titers of virus when a less sensitive cell system was used. In this study, the avidin-biotin immunoperoxidase method was more sensitive and much cheaper than hybridization with a biotinylated probe. Significantly, when a highly sensitive cell system was used, cytopathic changes alone were comparable in rapidity and sensitivity to viral antigen or DNA detection methods applied in a less sensitive cell system.
Aeration selects for mucoid phenotype of Pseudomonas aeruginosa
Authors: Krieg D P , Bass J A , Mattingly S J
Published: January 2020

A mucoid strain of Pseudomonas aeruginosa isolated from a patient with cystic fibrosis and its nonmucoid revertant were grown in a chemically defined alginate-promoting medium under batch and continuous culture conditions. Selection for the mucoid and nonmucoid phenotype was accomplished by varying the levels of air available to the culture. The addition of air at a rate of 0.5 liters/min to the nonmucoid revertant growing under batch or continuous culture conditions resulted in a greater than 50% decrease in viability over a 10-h incubation period. In contrast, aeration of the mucoid culture maintained a totally mucoid population and there was no decrease in viability over a 55-h incubation. Aeration of a mixed population of the mucoid and nonmucoid phenotype (1:1) resulted in selection for the mucoid phenotype within the first 20 h of cocultivation. The correlation between the mucoid phenotype and alginic acid was demonstrated by the production of 580 micrograms of uronic acid per mg (dry weight) of cells by the mucoid phenotype and less than 1 microgram of uronic acid per mg (dry weight) of cells by the nonmucoid revertant. These results suggest that nonmucoid revertants may have an unusual sensitivity to aeration, which may indicate a mechanism for natural selection of the mucoid phenotype in vivo.
Detection of immunoglobulin G antibodies to cytomegalovirus antigens by antibody capture enzyme-linked immunosorbent assay
Authors: Nielsen S L , Rønholm E , Sørensen I , Andersen H K
Published: January 2020

An antibody capture enzyme-linked immunosorbent assay (ELISA) that uses horseradish-peroxidase-labeled antigen for the detection of immunoglobulin G (IgG) antibodies to cytomegalovirus (CMV) is described. A microtiter plate was coated with anti-human IgG and consecutively incubated with serum specimens, enzyme-labeled CMV antigen made from CMV-infected cell nuclei, and substrate. The CMV IgG antibody content was determined spectrophotometrically and expressed as absorbance. Furthermore, to reveal any nonspecific reactions, all sera were tested against an enzyme-labeled control antigen made from uninfected cell nuclei. The problem with nonspecific reactions was small and was circumvented by the addition of unlabeled control antigen to the conjugates. For epidemiological studies the test was not as sensitive as other serological tests. On the other hand, the IgG antibody capture ELISA was highly sensitive for detecting the serological antibody response in patients with primary and recurrent CMV infections. Thus, one positive serum remained positive at a serum dilution of 1:10(7). The specificity of the test was shown by a blocking experiment and by testing 126 complement fixation-positive sera, of which 97% were positive. There was a rather good correlation between the complement fixation test and the IgG antibody capture ELISA (rs = 0.79, P less than 0.001). The test is especially useful when tests for CMV antibodies of the IgM, IgA, and IgE classes are run by similar antibody capture ELISAs, since the same procedure and conjugate are used.
In-hospital source of airborne Penicillium species spores
Authors: Streifel A J , Stevens P P , Rhame F S
Published: January 2020

Between 16 July and 1 October 1984, prospectively monitored corridor air samples from a bone marrow transplant station revealed a marked increase in airborne thermotolerant Penicillium spores. Simultaneous cultures of outside air showed lower spore counts, which were unchanged before, during, and after the corridor outburst, establishing that the source was within the hospital. Although the corridor was equipped with recirculating high-efficiency particulate air filtration units which provided 16 air changes per h, the mean corridor air count rose to 64.4 thermotolerant Penicillium CFU/m3 during the outburst period. The in-hospital source was ultimately traced to rotting cabinet wood enclosing a sink with leaking pipes in the medication room. It produced approximately 5.5 X 10(5) thermotolerant Penicillium CFU/h. In a patient room supplied by corridor air, an in-room recirculating high-efficiency particulate air filter reduced the mean thermotolerant Penicillium count to 2.2 CFU/m3. No patient illness or colonization occurred as a result of this event, although the cabinet wood, after sterilization, was shown to sustain abundant growth of Aspergillus fumigatus and Aspergillus flavus. Wet organic substrates should be avoided in hospital areas with immunosuppressed patients.
Comparative study of synthetic oligonucleotide and cloned polynucleotide enterotoxin gene probes to identify enterotoxigenic Escherichia coli
Authors: Echeverria P , Taylor D N , Seriwatana J , Moe C
Published: January 2020

Escherichia coli isolated from 2,126 children in Thailand and the Philippines was examined for enterotoxin production and for DNA hybridization with synthetic oligonucleotide and cloned polynucleotide enterotoxin gene probes. A total of 233 infections with E. coli that were detected by one or more of these assays were identified. Of the infections, 75% (164/233) were identified by all three methods. An additional 18% (43/233) were identified by two of three methods. Isolates from 10% (19/183) of infections with E. coli that hybridized with both the oligonucleotide and cloned enterotoxin gene probes were nontoxigenic, as determined by the Y1 adrenal cell and suckling mouse assays. Although synthetic oligonucleotide probes to detect enterotoxigenic E. coli are more uniform and easier to use than cloned enterotoxin gene probes, the heat-labile toxin oligo probe used in this study did not identify 13% (11/87) of infections with E. coli that produced heat-labile toxin, as identified with the Y1 adrenal cell assay and the cloned enterotoxin gene probe. Synthetic oligonucleotide probes enable laboratories with only minimal equipment to use DNA hybridization assays to identify enterotoxigenic E. coli.
Production of Escherichia coli STa-like heat-stable enterotoxin by Citrobacter freundii isolated from humans
Authors: Guarino A , Capano G , Malamisura B , Alessio M , Guandalini S , Rubino A
Published: January 2020

Citrobacter species are often present in the stools of children and are generally considered a normal component of the intestinal microflora. Previous reports suggested that they might act as enteric pathogens. Aiming at defining the role of Citrobacter species in inducing diarrhea, we looked for their presence in the stools of 328 children with diarrhea and in 108 controls. Citrobacter strains were isolated from 46 patients (14%) and 7 controls (6.5%) (P less than 0.05). All isolates were tested for heat-stable (ST) and heat-labile (LT) enterotoxin. No LT-producing organisms were found. Three C. freundii strains, all isolated from children with diarrhea, elaborated an enterotoxin detected by the suckling mouse assay. A crude extract was prepared by acetone precipitation and a sequential ultrafiltration technique. The enterotoxin was heat stable, and its estimated molecular weight was between 2,000 and 10,000. Citrobacter enterotoxin was soluble in methanol and stable at acid and neutral pHs but not above pH 8, and its activity was destroyed by treatment with 2-mercaptoethanol. Citrobacter enterotoxin was inactive in the 18-h rabbit ileal loop test. All these characteristics closely resemble STa produced by Escherichia coli. The time course of Citrobacter enterotoxin-induced intestinal secretion in suckling mice was similar to that of E. coli STa. The enterotoxin produced by C. freundii cross-reacted with monoclonal antibodies raised against E. coli STa. These results suggest that C. freundii is capable of inducing diarrhea through the production of an E. coli-like STa, and its presence in the stools of patients with diarrhea should be considered as that of a possible etiologic agent.
Fluorescence detection of Cryptosporidium oocysts in human fecal specimens by using monoclonal antibodies
Authors: Garcia L S , Brewer T C , Bruckner D A
Published: January 2020

With the discovery that the coccidian parasite Cryptosporidium sp. can cause severe symptoms in humans, implementation of many diagnostic techniques rapidly followed. The infection is self-limiting in patients with normal immune systems but chronic in the immunosuppressed patient. With the eventual development and use of therapeutic agents, it will become very important to find Cryptosporidium sp., even in low numbers, in fecal specimens. Production of a highly specific and sensitive antibody by use of cloning techniques has provided another diagnostic tool. Formalinized positive human fecal specimens (n = 99) and negative specimens (n = 198), of which 115 contained yeastlike fungi and other organisms, were tested in blind trials by use of a monoclonal antibody. Sensitivity was 100% with 3- to 4+ fluorescence on all cryptosporidial oocysts, both in light and heavy infections. The organisms were round and easily visible (4 to 6 micron), showing apple-green to yellow fluorescence against a dark background free of nonspecific fluorescence. Specificity was also 100% with all 99 positive Cryptosporidium sp. specimens exhibiting fluorescence and all 198 negative specimens showing no fluorescence. All positive and negative specimens were previously confirmed by the hot modified acid-fast technique. However, seven specimens previously considered negative by this acid-fast method were positive by the monoclonal antibody technique. These specimens were confirmed as positive, after extensive examination of additional smears prepared by the modified hot acid-fast method revealed rare organisms, emphasizing the increased sensitivity of the monoclonal antibody technique. Since acid-fast stains do not always consistently stain all oocysts, the increased sensitivity of the monoclonal reagent provides an excellent screening method.
Typing of herpes simplex virus by capture biotin-streptavidin enzyme-linked immunosorbent assay and comparison with restriction endonuclease analysis and immunofluorescence method using monoclonal antibodies
Authors: Nerurkar L S , Miller N R , Namba M , Monzon M , Brashears G , Scherba G , Sever J L
Published: January 2020

A sensitive enzyme-linked immunosorbent capture assay using biotin and streptavidin (capture B/SA ELISA) was developed using type-specific monoclonal antibodies for typing of herpes simplex virus. Rabbit anti-herpes simplex virus immunoglobulin G was used as the capturing antibody, and biotin-linked type-1-specific mouse monoclonal antibody or rabbit type-1- or type-2-specific polyclonal antibody served as the detecting antibody. The captured antigen was detected by an ELISA with alkaline phosphatase-conjugated streptavidin, which reacted with biotin molecules on the detector antibody. The capture B/SA ELISA was compared with other methods for efficiency and reliability in typing. Results obtained by restriction endonuclease digestion of the radiolabeled viral genome were used to determine the type (1 or 2) of clinical isolates. These results were then used as a reference for determining the accuracy of the capture B/SA ELISA, as well as that of the immunofluorescence method, both of which are easily adaptable for use in the clinical laboratory. The three methods were in perfect agreement. It was determined that both the capture B/SA ELISA and the immunofluorescence method using monoclonal antibodies provided typing results with 100% specificity and 100% sensitivity and thus were accurate and reliable. However, the ELISA was the method of choice because of its simplicity, rapidity, and use of nonradioisotopic reagents.
Epidemiology of equine herpesvirus 2 (equine cytomegalovirus)
Authors: Browning G F , Studdert M J
Published: January 2020

The epidemiology of equine herpesvirus 2 was examined by using restriction endonuclease DNA fingerprints to distinguish viruses isolated from two groups of horses. The first group consisted of three yearlings isolated from other horses but in contact with each other for 418 days, whereas the second comprised seven mares and their foals, which were sampled at monthly intervals from parturition until the foals were about 180 days old. There was a complex pattern of transmission, with 15 different viruses isolated from both groups. Four distinguishable viruses were isolated from the three yearlings by day 16 of quarantine, and by day 141 an additional two viruses were isolated. Up to five different viruses were isolated from one yearling. Although four repeat isolations of one virus from the nasal cavity of one yearling over 54 days indicated that equine herpesvirus 2 established persistent infection with constant shedding, most repeat isolations yielded distinguishable viruses. Identical viruses were isolated from the nasal cavity and leukocytes of one yearling and the nasal cavity and vagina of another, indicating that a particular equine herpesvirus 2 strain was not site specific. Although seven different viruses were isolated from the three yearlings throughout the quarantine period, two appeared to establish latent infections; one virus was not isolated until 141 days after quarantine, whereas the second was first isolated 16 days after quarantine and then for the second time, from the same horse, 402 days later. Multiple concurrent local infections were demonstrated by the isolation of two or more viruses from the same nasal swab.
Cytotoxic and enterotoxic activities of Campylobacter jejuni are not specified by tetracycline resistance plasmids pMAK175 and pUA466
Authors: Taylor D E , Johnson W M , Lior H
Published: January 2020

The 45-kilobase tetracycline resistance plasmids pMAK175 and pUA466 from Campylobacter jejuni were examined using curing and mating experiments. However, these plasmids encoded neither cytotoxin production, as determined in Vero cells, nor enterotoxin activity, as determined in Chinese hamster ovary cells.
Mycobacterium simiae and Mycobacterium avium-M. intracellulare mixed infection in acquired immune deficiency syndrome
Authors: Lévy-Frébault V , Pangon B , Buré A , Katlama C , Marche C , David H L
Published: January 2020

Acquired immune deficiency syndrome was diagnosed in a 43-year-old man, born and living in Congo. The patient presented a disseminated infection caused by mycobacteria which were recovered from blood, jejunal fluid, and duodenal and rectal biopsies. Identification, according to conventional tests and mycolate profile determination, showed that Mycobacterium avium-M. intracellulare and M. simiae were both involved.
Increased recovery of enteric pathogens by use of both stool and rectal swab specimens
Authors: Adkins H J , Santiago L T
Published: January 2020

During 1984, the recovery of enteric pathogens from patients with acute diarrhea was enhanced by the use of both rectal swab and stool specimens. With 513 patients for whom both methods were used, the overall recovery rate was increased a minimum of about 10%. Almost 50% of the organisms recovered were detected by only one method. For maximum recovery of diarrheal agents, the use of both methods is recommended when possible.
Rapid identification of mycoplasmas by indirect immunoperoxidase test using small square filter paper
Authors: Imada Y , Uchida I , Hashimoto K
Published: January 2020

The indirect immunoperoxidase test using small, square filter paper was used for rapid identification of mycoplasmas. Colonies of type strains of 22 mycoplasma species, 3 acholeplasma species, and three Ureaplasma diversum serogroups were stained by this test with high sensitivity and specificity. All of 49 isolates from bovine materials and cell cultures were easily identified by this test, and the results agreed with those obtained by growth inhibition test. Use of filter paper made it possible to add different kinds of antisera or conjugates to the same agar plate simultaneously and also to save antiserum and conjugate. This test proved to be a simple and useful technique for rapid identification of many mycoplasma species grown on agar medium.
Evaluation of four enrichment media for isolation of Campylobacter jejuni
Authors: Agulla A , Merino F J , Villasante P A , Saz J V , Díaz A , Velasco A C
Published: January 2020

Diarrheal stool specimens were inoculated into the following media: alkaline peptone water (APW), Bruce-Zochowsky medium (BZ), Campylobacter enrichment broth (CEB), Campy-thio broth (CT), and Skirrow blood-agar (SK) plate. All media were incubated at 42 degrees C in microaerophilic conditions for 24 h. Afterwards, a new SK plate was inoculated from every liquid medium. Campylobacter jejuni was isolated from 43 of the 259 specimens when CT was used, from 45 when APW was used, from 46 when BZ was used, and from 46 when CEB was used; these totals include specimens that grew after enrichment only, on SK plates only, and both after enrichment and on SK plates. No significant differences were found between the isolates obtained with and without enrichment procedures.
Determination of immune status in patients with low antibody titers for rubella virus
Authors: Fayram S L , Akin S , Aarnaes S L , Peterson E M , de la Maza L M
Published: January 2020

Three assays for detection of rubella antibodies, Rubella G (fluorescence immunoassay [FIA]), Rubacell (passive hemagglutination), and Rubaquick (passive hemagglutination with rotation), were compared with hemagglutination inhibition. A total of 100 serum specimens were selected, 68 of which had an FIA value of less than or equal to 25. On initial testing, among the four tests, there was agreement for 88 specimens for assignment of rubella immune status. On repeat testing, all the results agreed by the hemagglutination inhibition, passive hemagglutination, and passive hemagglutination rotation methods, and only one discrepant specimen remained by FIA.
Immunoglobulin M to cytomegalovirus in primary and reactivation infections in renal transplant recipients
Authors: Chou S , Kim D Y , Scott K M , Sewell D L
Published: January 2020

Two commercially available enzyme immunoassays and one assembled in house were used to measure immunoglobulin M (IgM) antibody to cytomegalovirus (CMV) in a total of 220 serum specimens from 104 renal transplant recipients. All assays included a step in which interfering IgG antibody was removed or complexed. Concordance of results between pairs of assays ranged from 84 to 96%. All sera from patients with recent seroconversion (primary CMV infection) had measurable anti-CMV IgM. Among those already seropositive to CMV when transplanted, 26 to 55% had IgM antibody posttransplant, depending on the assay. This was observed regardless of the CMV serologic status of the kidney donor, indicating that reactivation of endogenous CMV, as well as reinfection, can induce this antibody in transplant recipients. Four cadaver donors known to transmit CMV to eight recipients did not have measurable IgM antibody to CMV.
Thalassemic erythrocytes inhibit in vitro growth of Plasmodium falciparum
Authors: Brockelman C R , Wongsattayanont B , Tan-ariya P , Fucharoen S
Published: January 2020

Blood specimens from 100 thalassemic patients were screened in vitro for inhibitory effects on growth and multiplication of Plasmodium falciparum. The culture medium mixture designated REM consisted of 9 volumes of minimum essential medium (GIBCO Laboratories, Grand Island, N.Y.) and 1 volume of RPMI 1640 (GIBCO) supplemented with 10% heat-inactivated human serum. Parasite multiplication in erythrocytes containing normal hemoglobin cultured in RPMI or REM was similar. Significant reduction in parasite multiplication rates was observed in erythrocytes containing abnormal hemoglobin when these were cultured in REM. The degree of reduction in five types of thalassemic erythrocytes was in the following descending order: hemoglobin H disease with Hb Constant Spring, classical hemoglobin H disease, beta(0)-thalassemia-hemoglobin E in which blood harbored a high percentage of hemoglobin F-containing cells, beta (0)-thalassemia-hemoglobin E in which blood harbored few hemoglobin F-containing cells, and beta-thalassemia heterozygous variant.
Cobas-Bact system for identification of members of the family Enterobacteriaceae in 4 h 20 min
Authors: Wenger A , Tissières L J , Praplan F R , Kamm W R , Bille J
Published: January 2020

The Cobas-Bact (Roche Diagnostics, Basel, Switzerland) new rotor for the identification (ID) in 4 h 20 min of 33 members of the family Enterobacteriaceae to genus and species level was evaluated by testing 444 strains of which 398 belonged to common species and 46 belonged to rare species of Enterobacteriaceae. Each strain was identified by the API 20E system (Analytab Products, Plainview, N.Y.), and additional discriminating tests were set up if necessary. Only first-choice ID were considered in this study and were classified either as high-confidence ID (normalized likelihood, greater than or equal to 80%) or as low-confidence ID (normalized likelihood, less than 80%) requiring additional tests for confirmation. The data were analyzed by two versions of Cobas-Bact software. With the first version of the software (SW8446), the overall accuracy of Cobas-Bact was 95.5% (424 correct ID of 444). When restricted to high-confidence ID it rose to 99.4% (350 of 352) for the common species and 96.9% (31 of 32) for the rare species. Only three strains of the high-confidence group were misidentified. Sixty ID were considered unacceptable because of their low confidence. Using the first software version (SW8446) they represented 12% (46 of 398) of the common species (17 typical strains, 10 Shigella species, 10 inactive Escherichia coli strains, and 9 rare biotypes) and 30% (14 of 46) of the rare species. The same data analyzed by the new version (SW8524) of the Cobas-Bact software resulted in an overall accuracy of 93.9% (417 correct ID). The number of high-confidence ID rose to 401, of which 392 (97.7%) were accurate. The decrease in low-confidence ID (43 versus 60) was mainly due to the Shigella species. In conclusion the accuracy of Cobas-Bact identification system was very good when restricted to high-confidence ID. The Cobas-Bact performance for rare species ID was poorer, but the small number of strains tested does not allow definitive conclusions.
Immunogold silver staining for visualization of leptospires in histologic sections
Authors: Skilbeck N W , Chappel R J
Published: January 2020

An immunogold silver stain for leptospires in sections of Formalin-fixed, paraffin-embedded tissues is described. Leptospires were intensely stained, and nonspecific staining of the tissue background was negligible.
Investigation by syringe method of effect of tampons on production in vitro of toxic shock syndrome toxin 1 by Staphylococcus aureus
Authors: Lee A C , Crass B A , Bergdoll M S
Published: January 2020

A syringe method was designed to test the effect of tampons on the growth of three toxic shock syndrome-associated strains of Staphylococcus aureus and their in vitro production of toxic shock syndrome toxin 1 (TSST-1) under different conditions. Various amounts of TSST-1 were recovered from different tampons inoculated with these strains. Generally, the addition of 10% porcine blood to the growth medium, incubation in the presence of 5% CO2, or the combination of these two factors resulted in the stimulation of TSST-1 production.
Detection of Pneumocystis carinii by fluorescent-antibody stain using a combination of three monoclonal antibodies
Authors: Gill V J , Evans G , Stock F , Parrillo J E , Masur H , Kovacs J A
Published: January 2020

A combination of three monoclonal antibodies, two prepared against human and one against rat Pneumocystis carinii, was used in an indirect fluorescent-antibody stain (IFA) to diagnose P. carinii in both bronchoalveolar lavage and lung biopsy specimens. This combination of monoclonal antibodies was specific for P. carinii and yielded bright fluorescence of both P. carinii cysts and trophozoites. A total of 126 specimens from 93 patients were stained for P. carinii by a toluidine blue O stain and the monoclonal IFA. Forty-five (35.7%) of these were positive for P. carinii by toluidine blue O, and 43 (34.1%) were positive by IFA. There was 98.4% agreement between both methods, with no false-positive and two false-negative occurrences by IFA. An IFA procedure with monoclonal antibodies such as those used in these studies can provide a simple, fast, and sensitive method for diagnosing P. carinii pneumonia by microbiology laboratories.
Prospective study of serum antibodies to Pseudomonas aeruginosa exoproteins in cystic fibrosis
Authors: Hollsing A E , Granström M , Vasil M L , Wretlind B , Strandvik B
Published: January 2020

Serum immunoglobulin G to four purified antigens from Pseudomonas aeruginosa, phospholipase C, alkaline protease, exotoxin A, and elastase, were determined in 62 patients with cystic fibrosis by enzyme-linked immunosorbent assay. The patients were followed for 12 to 24 months in a prospective study. Increased titers, i.e., titers more than 2 standard deviations above those of normal controls, were exclusively found in patients chronically colonized with P. aeruginosa and not in patients harboring only Staphylococcus aureus. The frequencies of elevated titers of antibody to the different antigens varied from 100% (phospholipase C) to 58% (alkaline protease and exotoxin A) to 15% (elastase) in the chronically colonized patients. Mean serum titer levels, expressed as multiples of the age-correlated upper normal limit (=1), were significantly higher to phospholipase C in patients with dual colonization with P. aeruginosa and S. aureus than in those colonized only with P. aeruginosa (P less than 0.001). Conversely, the other three antigens showed significantly higher serum antibody titer levels in patients harboring only P. aeruginosa (P less than 0.001). In five patients who became colonized with P. aeruginosa during the study period, serum antibodies to phospholipase C and exotoxin A increased first. Exceptions to the general pattern of antibody responses were found in three patients chronically colonized with Escherichia coli. They showed a delayed enhancement of anti-phospholipase C titers after the chronic P. aeruginosa colonization. Serum titers were not influenced by exacerbations of pulmonary infection or by antimicrobial therapy. The determination of titers of serum antibody to phospholipase C seems to be a valuable indicator of a chronic colonization with P. aeruginosa. The results further suggest that bacterial metabolism and interactions may influence the antibody response.
Relationship of CDC group EO-2 and psychrobacter immobilis
Authors: Hudson M J , Hollis D G , Weaver R E , Galvis C G
Published: January 2020

Thirty strains of microorganisms previously classified in the CDC group EO-2 were studied to determine the relationship of this group and the recently proposed Psychrobacter immobilis. Results of transformation studies indicated that 9 of the 30 studied strains should be reclassified as P. immobilis. While transformation studies should be used to identify the Psychrobacter genus definitively, some presumptive characteristics useful in differentiating the CDC group EO-2 and P. immobilis were observed. The Psychrobacter genus, compared with the CDC group EO-2, grew well at 25 degrees C, lightly or not at all at 35 degrees C, and not at all at 42 degrees C, grew in nutrient broth without NaCl and with only one exception grew in 6% NaCl, usually did not produce acid from adonitol, dextrin, fructose, or D-mannitol, did not demonstrate the O-shaped cellular morphology, and usually possessed an odor resembling that noted from a phenylethyl alcohol blood agar plate.
Characterization of the new Chlamydia agent, TWAR, as a unique organism by restriction endonuclease analysis and DNA-DNA hybridization
Authors: Campbell L A , Kuo C C , Grayston J T
Published: January 2020

Several molecular techniques were used for comparison of the novel Chlamydia agent, TWAR, with Chlamydia trachomatis and Chlamydia psittaci. Unlike all serotypes of C. trachomatis and most strains of C. psittaci, the eight TWAR isolates examined did not contain extrachromosomal DNA. TWAR was readily distinguished from C. trachomatis or C. psittaci by restriction endonuclease analysis, whereas identical or nearly identical restriction patterns were observed among the TWAR isolates. Southern blot analysis with a gene encoding a portion of the C. trachomatis serovar L2 major outer membrane protein as the probe showed that TWAR, like C. psittaci, contained sequences homologous to this gene. However, while the hybridization patterns were identical for all TWAR isolates, they differed from those of any of the other Chlamydia species tested. A PstI gene bank containing TWAR DNA was constructed in pUC19. Random fragments were purified and used for probing Chlamydia chromosomal digests. All of the five probes tested were TWAR specific, with the TWAR isolates showing identical patterns of homology. Qualitative studies of the DNA homology revealed that TWAR did not have significant homology to any of the Chlamydia strains assayed. Collectively, these results demonstrate that the TWAR isolates represent a single strain or closely allied genotypes and are clearly distinct from any of the other chlamydiae tested.
Enteroadherent Escherichia coli as a cause of diarrhea among children in Mexico
Authors: Mathewson J J , Oberhelman R A , Dupont H L , Javier de la Cabada F , Garibay E V
Published: January 2020

Enteropathogenic Escherichia coli (EPEC) often exhibits localized adherence or diffuse adherence to HEp-2 cells. We recently provided evidence that HEp-2 cell-adherent or enteroadherent E. coli (EAEC) not belonging to EPEC serogroups was the cause of diarrhea among U.S. travelers to Mexico. In the present study, we looked for EAEC and EPEC in stool specimens from 154 children with acute diarrhea and 137 well children seen at several outpatient clinics in Guadalajara, Mexico. EAEC showing localized adherence (EAEC-L) was isolated from 13.0% of the patients and 0.7% of the controls (P less than 0.0001). EAEC showing diffuse adherence (EAEC-D) was recovered from 20.8% of the patients and 7.3% of the controls (P less than 0.001). EPEC was isolated from 4.5 and 6.7% of the patients and controls, respectively. Among all enteropathogens, only enterotoxigenic E. coli occurred as commonly (21.4%) as EAEC-D and EAEC-L did in children with diarrhea. Of the EAEC-L strains isolated from children with diarrhea, 20% belonged to recognized EPEC serogroups, and 3.1% of EAEC-D strains belonged to recognized EPEC serogroups. This study suggests that EAEC may be an important pediatric enteropathogen in Mexican children with diarrhea and further supports the observation that adherence to HEp-2 cells may be a marker of virulence independent of EPEC serogroup among E. coli strains.
Assessment of enzyme immunoassay and immunofluorescence tests for detection of Chlamydia trachomatis
Authors: Hipp S S , Han Y , Murphy D
Published: January 2020

Two rapid diagnostic tests for Chlamydia trachomatis (Microtrak, Syva Co., Palo Alto, Calif.; and Chlamydiazyme, Abbott Laboratories, North Chicago, Ill.) were evaluated in comparison with growth of the organism in tissue culture for 2,030 urogenital specimens from men and women. Neither test performed as well as culture, which detected 296 of 310 positive specimens. The overall sensitivity and specificity for Microtrak were 73 and 99%; corresponding values for Chlamydiazyme were 83 and 98%. The majority of false-negative results with both rapid tests occurred when cultures contained less than 10 inclusions per cover slip. There were also areas of unconfirmed reactivity for both tests that led us to suggest that a reporting category of "suspicious" be developed for certain test results. For Microtrak, the suspicious result is a slide containing fewer than 10 elementary bodies; for Chlamydiazyme, it is any absorbance reading less than 0.4. Creation of a "suspicious" category would lower the sensitivity for Chlamydiazyme considerably, to 64%, and increase the positive predictive value for females to 95%. Although this may result in the underreading of some specimens from males, the tests could then be used with greater confidence in females for whom testing is essential for appropriate treatment.