bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical comparison of the AutoMicrobic system gram-positive identification card, API Staph-Ident, and conventional methods in the identification of coagulase-negative Staphylococcus spp
Authors: Grasmick A E , Naito N , Bruckner D A
Published: January 2020

In an effort to rapidly identify coagulase-negative staphylococci (CNS), a clinical comparison was conducted with the AutoMicrobic system Gram-Positive Identification Card (GPI) (Vitek Systems, Inc.), the API Staph-Ident (Analytab Products), and the conventional methods of W. E. Kloos and K. H. Schleifer (W. E. Kloos and K. H. Schleifer, J. Clin. Microbiol. 1:82-88, 1975). CNS isolates tested included 157 from blood and 33 from urine in pure culture at greater than 10(5) CFU/ml. S. epidermidis accounted for 79.6 and 60.6% of the isolates from blood and urine, respectively. S. saprophyticus was the next most frequent urine isolate (27.4%). Other CNS species were isolated from blood and urine specimens with frequencies of less than 5%. Overall, the GPI correctly identified 158 (83.2%) of the 190 CNS, whereas the Staph-Ident identified 124 (65.3%) without further testing. This resulted in the GPI and Staph-Ident correctly identifying 95.9 and 74.5% of the S. epidermidis and 100 and 33% of the S. saprophyticus, respectively. The GPI misidentified 8 (47%) of the S. hominis and S. warneri isolates as S. saprophyticus, indicating the need for novobiocin testing. These data suggest that the GPI is a more definitive method for the rapid identification of S. epidermidis than the Staph-Ident and that both systems require additional testing to identify S. saprophyticus.
Kinetic-dependent enzyme-linked immunosorbent assay for detection of antibodies to Legionella pneumophila
Authors: Sampson J S , Wilkinson H W , Tsang V C , Brake B J
Published: January 2020

A semiautomated, kinetic-dependent, enzyme-linked immunosorbent assay (K-ELISA) was adapted to detect serum antibodies to Legionella pneumophila. In a comparative study, 158 human serum samples (79 pairs) were tested by K-ELISA and the standard indirect immunofluorescence assay for determination of antibody levels to L. pneumophila serogroup 1. K-ELISA determinations were made by using a serogroup-specific antigen or a preparation (unfractionated antigen) which contained both common antigen and serogroup-specific reactivity. There was good correlation between the immunofluorescence assay and the K-ELISA by using either antigen, although greater correlation was achieved with the unfractionated antigen (coefficients of correlation, 0.894 with unfractionated antigen and 0.841 with serogroup-specific antigen). These results indicate that the K-ELISA is a reliable alternative to the immunofluorescence assay for serologically diagnosing legionellosis.
Identification and serotyping of Haemophilus pleuropneumoniae by coagglutination test
Authors: Mittal K R , Higgins R , Larivière S
Published: January 2020

A coagglutination test for the identification and serotyping of Haemophilus pleuropneumoniae is described. A total of 360 H. pleuropneumoniae strains were isolated from pulmonary tissues of feeder pigs which died of acute pleuropneumonia. All of the isolates were serotyped by coagglutination, and the results were confirmed by the ring precipitation test. The most common serotype isolated in Quebec was serotype 1, followed by serotypes 5, 2, and 7. None of the isolates belonged to serotypes 3, 4, or 6. Mixed infections due to H. pleuropneumoniae of more than one serotype in the same animal were encountered. Serotype 1 was the only common isolate among the mixed-serotype infections. The coagglutination test was more sensitive than was the ring precipitation test. Serotyping by the coagglutination test is inexpensive, rapid, reliable, and easy to perform.
Investigation of a waterborne outbreak of Campylobacter jejuni enteritis with a serotyping scheme based on thermostable antigens
Authors: Penner J L , Pearson A D , Hennessy J N
Published: January 2020

Serotyping of 11 human and 2 water isolates of Campylobacter jejuni associated with a waterborne outbreak revealed two serotypes among the human isolates. One of these (serotype 58) was a new serotype and was added to the serotyping scheme. Serotypes were defined by using extracted thermostable antigens and passive hemagglutination titrations of both unabsorbed and cross-absorbed antisera. Two water isolates of the same serotype as six human isolates provided evidence to link a contaminated water supply to the outbreak.
Examination of the morphology of bacteria adhering to peritoneal dialysis catheters by scanning and transmission electron microscopy
Authors: Marrie T J , Noble M A , Costerton J W
Published: January 2020

We examined Tenckhoff peritoneal catheters by scanning and transmission electron microscopy to study the morphology of bacterial adherence. Two catheters were removed from uninfected patients, three from patients with exit site infections, four from patients with peritonitis, and one from a patient with both exit site infection and peritonitis. Infecting organisms included three of Staphylococcus aureus and one each of Enterobacter sp., Staphylococcus epidermidis, Achromobacter xylosoxidans, Serratia sp., Klebsiella sp., and Candida albicans. Considerable morphological variation in adherence to the peritoneal dialysis apparatus occurred. No inflammatory cells were ever seen in association with infected cuffs, only two of the five patients with peritonitis had inflammatory cells associated with their catheters. In both instances, these cells tended to occur in clumps and demonstrated no flattening when in contact with the surface. Colonization of the catheter was uneven--bacteria tended to occur in clusters. Extensive matrix formation was evident in several instances, and condensation of this matrix onto the bacteria during the dehydration process rendered clumps of bacterial cells amorphous at times. Bacteria were adherent to the subcutaneous cuff in those patients with exit site infections. Gram-negative bacteria attached to individual dacron fibers of the cuff, often several layers deep. Gram-positive bacteria tended to adhere in clusters.
Isolation of two strains of Acanthamoeba castellanii from human tissue and their pathogenicity and isoenzyme profiles
Authors: Visvesvara G S , Mirra S S , Brandt F H , Moss D M , Mathews H M , Martinez A J
Published: January 2020

Two strains of amoebae, one (CDC:0180:1) from the lung tissue of a patient who died of granulomatous amoebic encephalitis and the other (CDC:0179:1) from the debrided tissue of a mandibular autograft, were isolated and identified as Acanthamoeba castellanii based on the morphological and immunofluorescent staining characteristics of the trophozoites and cysts. Both strains of amoebae caused cytopathic effects in mammalian cell cultures and destroyed the cell sheet. However, only the CDC:0180:1 strain, on intranasal instillation into mice, produced the disease manifested by ruffled fur and aimless wandering, followed by coma and death within 30 days. The CDC:0180:1 strain also differed consistently from CDC:0179:1 and another nonpathogenic A. castellanii strain (ATCC 30,011) in isoenzyme makeup, a dissimilarity which probably reflects its pathogenic potential.
Rapid latex particle agglutination test for Escherichia coli strains of porcine origin producing heat-labile enterotoxin
Authors: Finkelstein R A , Yang Z S , Moseley S L , Moon H W
Published: January 2020

A latex particle agglutination test previously shown to be suitable for the rapid identification of Escherichia coli strains of human origin producing heat-labile enterotoxin (R. A. Finkelstein and Z. Yang, J. Clin. Microbiol. 18:23-28) is equally applicable to strains of porcine origin.
Identification of enterotoxigenic Escherichia coli isolated from swine with diarrhea in Thailand by colony hybridization, using three enterotoxin gene probes
Authors: Patamaroj U , Seriwatana J , Echeverria P
Published: January 2020

The DNA colony hybridization assay was used to identify enterotoxigenic Escherichia coli among E. coli isolated from 803 swine with diarrhea at 10 farms in Thailand. Between 5 September and 8 December 1981, enterotoxigenic E. coli were identified in 40% of 58 litters of piglets under 10 days old and 17% of 29 litters between 10 and 21 days old with diarrhea at farms at four different locations in Thailand. All E. coli that hybridized with one or more of the three enterotoxin gene probes produced heat-labile or heat-stable toxin or both, as determined by testing culture supernatants in the Y1 adrenal and suckling mouse assays. The DNA colony hybridization technique is a specific method of identifying enterotoxigenic E. coli from swine and can be used to further characterize these enteric pathogens.
Bacterial growth and endotoxin production in lipid emulsion
Authors: Jarvis W R , Highsmith A K
Published: January 2020

Klebsiella pneumoniae serotypes 21 and 24 and Enterobacter cloacae were responsible for an outbreak of polymicrobial bacteremia associated with the receipt of lipid emulsion. Since it is recommended that lipid emulsion be kept refrigerated between uses, we undertook a study to determine the growth characteristics of these organisms in lipid emulsion at 5 and 25 degrees C and to examine the use of alternative measurements (pH and endotoxin) to determine contamination by viable and nonviable microorganisms. The bacteria survived but did not proliferate at 5 degrees C; no endotoxin was detected, and the pH remained unchanged. In contrast, after a 2-h lag phase, all three organisms proliferated rapidly when incubated at 25 degrees C and reached concentrations of greater than or equal to 10(7) CFU/ml at 24 h. A decrease in pH was detected after proliferation to 10(7) CFU/ml. Endotoxin was detected after proliferation reached 10(2) CFU/ml. The amount of endotoxin elaborated by the three organisms differed and ranged from 0.013 ng per 8 X 10(2) CFU/ml to 1.3 ng per 2 X 10(3) CFU/ml at 8 h. Our findings show that these microorganisms do not proliferate at refrigerator temperature in lipid emulsion, but can reach significant levels at room temperature. It is, therefore, important to keep lipid emulsion refrigerated between uses. Furthermore, when lipid emulsion contamination is suspected, endotoxin and pH determinations should be considered as possible adjunctive tests while results of bacterial cultures are pending. The results of the present study are applicable to only selected gram-negative bacteria and may not apply to gram-positive bacteria and fungi. However, these data demonstrate that measurement of pH and detection of endotoxin is quite useful when lipid emulsion contamination occurs with selected gram-negative bacteria.
Elevated serum D-arabinitol levels in patients with sarcoidosis
Authors: Karam G H , Elliott A M , Polt S , Cobbs C G
Published: January 2020

D-Arabinitol has been found in the serum of patients with candidiasis in an incidence varying from 38 to 82%. While screening serum by gas chromatography for the presence of this sugar, we observed elevated concentrations in several patients with sarcoidosis. In an attempt to determine the significance of this chance observation, we tested serum from additional patients with sarcoidosis along with serum from patients with other clinical conditions known to be associated with elevated D-arabinitol levels. Of 53 patients with sarcoidosis, 27 (51%) had elevated concentrations of this compound. Only one of these patients had decreased renal function (creatinine, 2.5 mg/dl). We were unable to correlate elevated values with extent of the disease. Although the significance of this finding is not clear, it may represent a clue to the pathogenesis of sarcoidosis.
Comparative evaluation of different enzyme-linked immunosorbent assay systems for the detection of staphylococcal enterotoxins A, B, C, and D
Authors: Fey H , Pfister H , Rüegg O
Published: January 2020

We compared four versions of the enzyme-linked immunosorbent assay for their suitability for detecting staphylococcal enterotoxins. The sandwich with labeled antibody proved to be the best. We used it with a sorbent consisting of antibody-coated polystyrene spheres reacted with 20 ml of food extract. The sensitivity of the test was 0.1 ng of enterotoxin per ml, which is far below clinical relevance. The succinimidyl-pyridyl-dithio-propionate enzyme coupling method of Pharmacia was superior to the two-step glutaraldehyde technique. Interfering protein A was eliminated by the simple addition of normal rabbit serum to the extracts. A diagnostic kit is now available.
Colistin-oxolinic acid-blood agar: a new selective medium for streptococci
Authors: Petts D N
Published: January 2020

The development and evaluation of a new selective medium (colistin-oxolinic acid-blood agar) for streptococci is described. Streptococci of medical and veterinary importance grew well on the medium. Gram-negative organisms, staphylococci. Bacillus spp., and coryneforms are all inhibited. It was concluded that the medium is valuable for the isolation of streptococci in pure culture from mixed flora and has advantages over other media previously described. Increased isolation rates were obtained together with earlier identification of the isolated strains.
Biotyping of Aeromonas isolates as a correlate to delineating a species-associated disease spectrum
Authors: Janda J M , Reitano M , Bottone E J
Published: January 2020

A group of 147 Aeromonas isolates from diverse clinical and environmental sources was subjected to the biotyping scheme of Popoff and Veron. Of the 147 isolates biotyped, 137 (93%) could be identified, with Aeromonas hydrophila predominating (48%) and equal percentages (25 to 27%) of the other two species (Aeromonas sobria and Aeromonas caviae). A number of additional biochemical properties were found to be significantly associated with one or more of these three species. These included lysine decarboxylase activity, hemolysis of sheep erythrocytes, lecithinase production, staphylolytic activity, arbutin hydrolysis, and acid production from utilization of various carbohydrates. By incorporating these phenotypic properties into an extended biotyping system, 98% of the isolates were identified. Selective distribution of individual species with respect to certain body sites was noted.
Measurement of microbial alpha-amylases with p-nitrophenyl glycosides as the substrate complex
Authors: Trepeta R W , Edberg S C
Published: January 2020

The detection of alpha-amylase is commonly used in clinical microbiology laboratories to aid in differentiating Streptococcus bovis from other streptococci. It is also useful in identifying Eikenella corrodens and the gravis subspecies of Corynebacterium diphtheriae and in separating species of the genera Bacteroides, Clostridium, Actinomyces, and Bacillus. Currently, the most frequently used procedure utilizes starch as the substrate and iodine as the indicator. Starch is incorporated into a agar medium, the isolate is inoculated on the surface, and the medium is incubated for 24 to 48 h. A 15-min test containing p-nitrophenyl polyglycosides as the substrate complex was developed to yield results comparable with the agar-based starch test. The reagent was made in liquid form, 0.20 ml per tube, and could be incubated either in ambient air or at 35 degrees C. When dried, the p-nitrophenyl polyglycoside reagent could be stored at 0 degrees C for 4 weeks.
Characterization of Neisseria cinerea, a nonpathogenic species isolated on Martin-Lewis medium selective for pathogenic Neisseria spp
Authors: Knapp J S , Totten P A , Mulks M H , Minshew B H
Published: January 2020

An asaccharolytic, gram-negative, oxidase-positive diplococcus was isolated on Martin-Lewis medium from the cervix of a patient attending an arthritis clinic at Seattle Public Health Hospital, Seattle, Wash. This strain, NRL 32165, did not produce detectable acid from glucose, maltose, sucrose, fructose, mannitol, or lactose in either cystine Trypticase agar (BBL Microbiology Systems, Cockeysville, Md.) or modified oxidation-fermentation medium and was identified presumptively as a glucose-negative Neisseria gonorrhoeae strain, but was identified later as Neisseria cinerea on the basis of its biochemical reactions. Nitrate was not reduced, nitrite (0.001%, wt/vol) was reduced, and polysaccharide was not produced from sucrose. Proline, arginine, and cystine-cysteine were required for growth on defined medium. Strain NRL 32165 did not react with antigonococcal protein I monoclonal antibodies and did not produce immunoglobulin A protease. In DNA:DNA homology studies with N. gonorrhoeae NRL 8038 (F62) and N. cinerea type strain NRL 30003, strain NRL 32165 showed 95% homology relative to N. cinerea and 44% homology relative to N. gonorrhoeae. Thus, the identity of strain NRL 32165 was confirmed as N. cinerea (von Lingelsheim 1906) Murray 1939. Of all Neisseria spp., N. cinerea is most likely to be misidentified as a glucose-negative N. gonorrhoeae strain.
Evaluation of PPLO, A7B, E, and NYC agar media for the isolation of Ureaplasma urealyticum and Mycoplasma species from the genital tract
Authors: Yajko D M , Balston E , Wood D , Sweet R L , Hadley W K
Published: January 2020

Four agar media (PPLO, NYC, A7B, and E) which are commonly used for the isolation of urogenital tract Mycoplasma species and Ureaplasma urealyticum were compared by culturing swabs of the endocervix of 334 pregnant women on all four media. To permit growth of both Mycoplasma and U. urealyticum, selective ingredients were omitted from the media tested. A7B and E agar were both satisfactory for the isolation of Mycoplasma species, recovering 92 and 82%, respectively, of all Mycoplasma species isolated. Only A7B agar was satisfactory for U. urealyticum isolation, recovering 96% of all isolates. Several modifications of PPLO, NYC, and E agar failed to significantly improve recovery of U. urealyticum on these media. A7B agar was clearly superior to all other media tested in terms of recovery rate, typical appearance of colonies, and ease of reading. A7B can be used for the isolation of both U. urealyticum and Mycoplasma species from urogenital sites.
Incidence and origin of Clostridium difficile in neonates
Authors: Al-Jumaili I J , Shibley M , Lishman A H , Record C O
Published: January 2020

The stools of 65 of 92 (71%) infants in a special care nursery yielded Clostridium difficile on culture. Ninety percent of stools collected after 6 to 35 days in the unit were positive, and 36% of these also contained toxin. When tested in vitro, 94% of the isolates produced toxin. Of 110 swabs collected from the environment of the unit, 9% were positive for C. difficile, but the stools of 12 nurses working on the unit were negative. Thirty-five vaginal swabs collected from mothers just before delivery were negative for C. difficile on culture, but 16 of their infants had C. difficile in their stools. It was concluded that there is a high carriage rate in the stools of neonates of C. difficile acquired progressively during the course of their stay in the special care unit. Infection is mainly from environmental sources rather than maternal transmission.
Splenic abscess caused by Shigella flexneri and Bacteroides fragilis
Authors: Drow D L , Mercer L , Peacock J B
Published: January 2020

We report a case of splenic abscess from which only Shigella flexneri (serotype 1a) and Bacteroides fragilis were isolated. The patient was a 59-year-old diabetic female who displayed minimal gastrointestinal symptoms. The S. flexneri isolate was resistant to chloramphenicol and tetracycline. The possible synergistic relationship between the two organisms is discussed.
Identification of group C streptococcal antigen extracts with lectin-bound polystyrene particles
Authors: Slifkin M , Gil G M
Published: January 2020

Crude extracts of Dolichos biflorus can be coupled to polystyrene particles to yield an agglutination reagent for the detection of group C streptococcal antigen extracts. The reagent is relatively inexpensive and simple to prepare and can be employed for the definitive identification of this beta-hemolytic streptococcus.
Comparison of plasmid profile analysis, phage typing, and antimicrobial susceptibility testing in characterizing Salmonella typhimurium isolates from outbreaks
Authors: Holmberg S D , Wachsmuth I K , Hickman-Brenner F W , Cohen M L
Published: January 2020

We compared the phage types, antimicrobial resistance patterns, and plasmid profiles of 20 groups of isolates received at the Centers for Disease Control from Salmonella typhimurium outbreaks between 1975 and 1982 to determine the most useful laboratory method for identifying epidemiologically related isolates of S. typhimurium. In 18 (90%) of the 20 outbreaks, epidemiologically related isolates were identified as being the same by each of the three methods. In a subgroup of nine outbreaks in which isolates unrelated to the outbreak were submitted for comparison, outbreak isolates were differentiated from such control isolates six times (67%) by phage typing alone, four times (44%) by antimicrobial susceptibility testing alone, and eight times (89%) by plasmid profile analysis alone. Epidemic isolates were multiply susceptible, nontypable, or without plasmids in 14 (70%), 1 (5%), and 3 (15%), respectively, of the 20 outbreaks. Plasmid analysis appeared to be at least as specific as phage typing in identifying epidemiologically related isolates of S. typhimurium as being the same or in differentiating them from control specimens; both techniques appeared to be superior to antimicrobial susceptibility testing.
Isolation and serotyping of porcine rotaviruses and antigenic comparison with other rotaviruses
Authors: Bohl E H , Theil K W , Saif L J
Published: January 2020

Seven rotavirus strains were isolated in cell cultures from the intestinal contents of piglets with diarrhea. MA104 cells with pancreatin in the cell culture medium was the host system of choice for virus isolation and replication. A cell culture immunofluorescence test in which MA104 cells were used in microtiter plates was very effective for detecting and assaying rotaviruses. A plaque reduction neutralization test, cross-protection studies in gnotobiotic pigs, and electrophoresis of rotaviral double-stranded RNA were used for comparing viruses. Three strains produced plaques on initial isolation attempts, replicated well in cell cultures, and were antigenically very similar. We suggest that these three strains be considered porcine rotavirus serotype 1, with The Ohio State University (OSU) strain serving as the prototype. The OSU strain was distinct from bovine, simian, canine, and human (Wa and M) rotaviruses by plaque reduction neutralization. Four strains did not produce plaques on initial isolation attempts, were difficult to adapt to cell cultures, and were related to each other but were distinct from the serotype 1 strains. We suggest that the Gottfried (G) strain be tentatively considered as a prototype for porcine rotavirus serotype 2. The G strain was antigenically closely related to canine and simian rotaviruses and less so to human M rotavirus (human rotavirus serotype 3). Canine, simian, and human M rotaviruses were closely related. All seven porcine rotavirus strains caused diarrhea in gnotobiotic pigs. Cell-cultured vaccines of the OSU and G strains caused only mild or no diarrhea in gnotobiotic pigs, and protection occurred when such pigs were challenged with homologous, bur not heterologous, virulent viruses. A survey indicated that 94% of 274 porcine serum samples and 100% of 75 herds were serologically positive to the porcine OSU rotavirus.
Interpretive standards and quality control limits for susceptibility tests with ampicillin-sulbactam combination disks
Authors: Barry A L , Jones R N , Thornsberry C
Published: January 2020

In vitro studies were performed to evaluate susceptibility tests with disks containing 10 micrograms of ampicillin plus 10 micrograms of sulbactam. Interpretive zone standards of less than or equal to 11 mm (resistant), 12 to 13 mm (intermediate), and greater than or equal to 14 mm (susceptible) are proposed. A nine-laboratory coordinated study was performed to establish tentative zone size limits for quality control of ampicillin-sulbactam disks. This included data with a new control strain selected to monitor performance of such combination disks.
Nosocomial colonization and infection by Achromobacter xylosoxidans
Authors: Reverdy M E , Freney J , Fleurette J , Coulet M , Surgot M , Marmet D , Ploton C
Published: January 2020

Achromobacter xylosoxidans, a bacterial species named in 1971, is often isolated from aqueous environments, but little has been reported about its pathogenicity in humans, its epidemiological pattern, and its susceptibility to antibiotics and antiseptics. We were faced with an epidemic caused by this microorganism for 18 months in an intensive care unit. Two patients had fatal infections and 37 others were colonized. The source was the deionized water of the hemodialysis system. The 46 isolates were identified by comparison with the reference strain A. xylosoxidans ATCC 27061. The characteristic cellular fatty acids of this species were demonstrated by gas-liquid chromatography. The minimal inhibitory concentrations of 27 antibiotics were determined. The isolates were susceptible to only two: moxalactam at 4 micrograms/ml and ceftazidime at 8 micrograms/ml. The minimal bactericidal concentrations of one disinfectant and three antiseptics were: sodium hypochloride, 109 micrograms/ml; chlorhexidine digluconate in ethanol solution, 15 to 125 micrograms/ml; polyvinylpyrrolidone iodine, 750 micrograms/ml; and iodine ethanol, 312 to 625 micrograms/ml.
Epidemiological aspects of enteritis due to Campylobacter spp. in Norway
Authors: Lassen J , Kapperud G
Published: January 2020

Data pertaining to 249 patients with stool cultures positive for thermophilic campylobacters are presented. Campylobacters were isolated from about 3% of all cases of acute enteritis and occupied second place in the bacterial etiology of this syndrome following Salmonella spp. Concomitant isolation of salmonellae or shigellae or both was achieved in 40 (16.1%) of the patients infected with campylobacters. The results suggest a bimodal age distribution with highest rates in young adults aged 20 to 29 years and children below 10 years of age. A majority of the campylobacters were isolated from travellers returning from abroad, and, to a lesser extent, from immigrants, particularly from Asia. Immigrants accounted for 45.2% of the patients below 10 years of age. The number of cases increased during the warmer months of the year. Travelling habits could, at least in part, explain the observed seasonality, age distribution, and geographical origin of infection. Eight outbreaks of Campylobacter enteritis were detected, five of which were family outbreaks, whereas three involved people from different families.
Enterotoxin production in relation to taxonomic grouping and source of isolation of Aeromonas species
Authors: Turnbull P C , Lee J V , Miliotis M D , Van de Walle S , Koornhof H J , Jeffery L , Bryant T N
Published: January 2020

A total of 19 of 20 (95%) strains of Aeromonas hydrophila biovar hydrophila and 16 of 17 (94%) strains of Aeromonas sobria isolated from a variety of clinical and environmental sources were found to be enterotoxin positive. Only 2 of 18 (11%) A. hydrophila biovar anaerogenes and 2 of 13 (15%) unidentified Aeromonas strains from a similar variety of sources produced enterotoxin. No association was apparent between the source of isolation, in particular diarrheal stools, and enterotoxigenicity; 41% of the isolates from diarrheal stools were enterotoxin negative. A strong correlation was noted between ability to produce enterotoxin and positive results in six characters: lysine decarboxylase and Voges-Proskauer reactions, production of gas from glucose, gluconate oxidation, xanthine hydrolysis, and hemolysis of human erythrocytes. In the majority of cases (35 of 39 strains), enterotoxigenicity was detected using cell-free filtrates of brain heart infusion broth cultures grown at 36 degrees C for 15; however, the other four positive isolates were detected after growth in the same broth at 30 degrees C or in Casamino Acids-yeast extract broth at 30 or 37 degrees C. It is recommended that for enterotoxin tests, strains should be grown in both media at both temperatures. The infant mouse test was found to be a simple and reliable method for detection of the enterotoxin. The toxin proved to be heat labile and not neutralized by cholera antitoxin.
Effectiveness of the antimicrobial removal device, BACTEC 16B medium, and thiol broth in neutralizing antibacterial activities of imipenem, norfloxacin, and related agents
Authors: Weinberg E , Shungu D L , Gadebusch H H
Published: January 2020

The Antimicrobial Removal Device (ARD), BACTEC 16B medium, and Thiol broth were evaluated for their effectiveness in reducing the activity of imipenem (IPM), cefoxitin, moxalactam, and ceftazidime in blood samples. In addition, the capability of the ARD and Thiol broth to bind norfloxacin and the ARD to bind oxolinic and nalidixic acids in urine samples was investigated. At the highest concentrations of the drugs tested (32 micrograms/ml for the four beta-lactams and 256 micrograms/ml for the three quinolinecarboxylic acids), there was at least a 95% reduction in the in vitro activity of each of the antibacterial agents for treated versus untreated samples. Of the compounds tested in the ARD system, the organic acids were more completely removed than were the beta-lactams. The Thiol broth was more effective than the ARD and the BACTEC 16B medium in inactivating imipenem, but it had no effect on the antibacterial activity of norfloxacin.
Enzyme-linked immunosorbent assay with a monoclonal antibody for detecting group A meningococcal antigens in cerebrospinal fluid
Authors: Sugasawara R J , Prato C M , Sippel J E
Published: January 2020

Hybridomas were produced from spleen cells of BALB/c mice immunized with a membrane preparation from Neisseria meningitidis group A strain 4402 and S194/5.XXOBU.14 myeloma cells. The hybridomas were screened for secretion of antibodies suitable for an enzyme-linked immunosorbent assay (ELISA) diagnostic for group A meningococcal meningitis. One hybridoma antibody, 3G7, was directed against the pilus protein. This antibody bound to all six lipopolysaccharide and protein group A meningococcal serotyping strains, as well as to meningococcal strains from serogroups C, W135, and Y, but not to a strain of Escherichia coli, Haemophilus influenzae type b, or to two or more strains of Streptococcus pneumoniae, Neisseria gonorrhoeae, and Salmonella typhi. The ELISA used on antibody, antigen, antibody-conjugate sandwich. Rabbit anti-meningococcal serum was the coating antibody for the antibody sandwich, cerebrospinal fluids contained the bacterial antigens, and 3G7-alkaline phosphatase conjugate was the detecting antibody. The monoclonal antibody conjugate ELISA system was able to detect group A meningococcal antigens in 21 of 25 cerebrospinal fluid specimens that were positive in an immune rabbit serum conjugate ELISA; cerebrospinal fluid samples from patients with Haemophilus meningitis served as the controls. Counterimmunoelectrophoresis detected meningococcal antigens in 16 of the same 25 cerebrospinal fluid samples.
Enzyme-linked immunosorbent assays based on polyclonal and monoclonal antibodies for rotavirus detection
Authors: Beards G M , Campbell A D , Cottrell N R , Peiris J S , Rees N , Sanders R C , Shirley J A , Wood H C , Flewett T H
Published: January 2020

We describe two enzyme-linked immunosorbent assays for rotavirus antigen in feces, which were designed to be as sensitive and specific as possible, and easy to use anywhere. Both are indirect methods, using the antibody capture method, but the second assay utilizes a rotavirus group-specific monoclonal "detecting" antibody instead of the hyperimmune polyvalent guinea pig antisera used in the first assay. Both tests were found to be more sensitive than electron microscopy for detecting virus. To develop these tests, solid phase, antiserum production methods, treatment of the test antigen with EDTA, substrate, stability of reagents, and the need for confirmatory "blocking" tests were all examined. The first assay described is that used at present by the World Health Organization for their worldwide diarrheal disease control program.
Efficient coating of the solid phase with rotavirus antigens for enzyme-linked immunosorbent assay of immunoglobulin A antibody in feces
Authors: Inouye S , Matsuno S , Yamaguchi H
Published: January 2020

Sensitivity of the enzyme-linked immunosorbent assay for detecting serum antibodies to rotavirus was greatly enhanced when rotavirus particles were fragmented by chaotropic agents (NaSCN or guanidine hydrochloride) before adsorption of the antigens to the solid phase. For detecting fecal antibodies, the addition of fetal calf serum to the diluent was further needed to protect the antigens from the proteolytic activity of feces. With this technique, we readily detected immunoglobulin A antibody in feces from infantile gastroenteritis patients. Rate-zonal centrifugation of feces revealed that immunoglobulin A antibody activity sedimented with two peaks: one at 11S with a secretory component and another sedimenting slower than 7S, presumably as Fab portions.
Enzyme immunoassay for rabies antibody in hybridoma culture fluids and its application to differentiation of street and laboratory strains of rabies virus
Authors: Smith J S , Sumner J W , Roumillat L F
Published: January 2020

A rapid and sensitive enzyme immunoassay is described for detecting rabies antibody in hybridoma culture fluids. Glass fiber filter disks were used to immobilize gamma-irradiated mouse neuroblastoma cells infected with street or laboratory strains of rabies virus. Bound rabies-specific antibody was detected by reaction with horseradish peroxidase-labeled goat anti-mouse immunoglobulin G. The assay was performed in a 96-well filtration device developed by Cleveland et al. (J. Clin. Microbiol. 15:402-407, 1982) for the typing of herpes simplex viruses. When partially disrupted cells were used, both internal and external viral antigens were available for reaction. The procedure is rapid (less than 4 h for completion) and requires only small amounts of fluid, and the gamma-irradiated antigen is noninfectious. When the procedure was used to screen 145 fluids from rabies-immune spleen-myeloma cell fusions, 132 were positive for rabies antibody. Other commonly used assays for the detection of rabies-specific antibody were less sensitive. Simultaneous analyses of many hybridoma fluids against a battery of street and laboratory strains of rabies virus are possible and allow rapid selection of useful monoclones.
Detection of Clostridium difficile toxin with McCoy cell monolayers and cell suspensions and comparison with HeLa cell assay
Authors: Maniar A C , Chubb H , Louie T J , Williams T W , Forsyth W , Wilt J C
Published: January 2020

McCoy cell monolayers were compared with HeLa cell monolayers for the detection of Clostridium difficile toxin in 301 stool samples. Tests were positive (greater than or equal to 1/100 dilution) in 83 and 81 specimens tested with McCoy and HeLa cell monolayers, respectively. McCoy cell suspensions were compared with HeLa cell monolayers in 532 stool filtrates. Overall, 90 positive specimens were within one dilution and 432 filtrates were negative with either test, giving a correlation coefficient of r = 0.98. McCoy cell monolayers or suspensions may be a satisfactory substitute for the detection of C. difficile toxin in clinical specimens.
Isolation of nontoxigenic Vibrio cholerae O group 1 from a patient with severe gastrointestinal disease
Authors: Morris J G , Picardi J L , Lieb S , Lee J V , Roberts A , Hood M , Gunn R A , Blake P A
Published: January 2020

A nontoxigenic strain of Vibrio cholerae O group 1 was isolated in Florida from the stool of a patient with severe diarrhea. The strain had the same hemolytic and unique phage-sensitivity pattern as all toxigenic isolates from recent cases of cholera in Texas and Louisiana. Identical strains were transiently isolated from sewerage systems in two other Florida communities, suggesting that multiple human infections had occurred. This is the first indication that V. cholerae O1 strains which do not produce cholera toxin may be able to cause gastrointestinal disease in humans. The identification of these strains also raises questions about the relationship between toxigenic and nontoxigenic strains of V. cholerae O1 along the Gulf Coast of the United States.
Evaluation of various plastic microtiter plates with measles, toxoplasma, and gamma globulin antigens in enzyme-linked immunosorbent assays
Authors: Shekarchi I C , Sever J L , Lee Y J , Castellano G , Madden D L
Published: January 2020

Seventeen lots of microtiter plates which differed in lot, batch, plastic type, or manufacturer were evaluated as solid-phase carriers in enzyme-linked immunosorbent assays for antibodies to measles, toxoplasma, and human gamma globulin. Most plates of polystyrene or polyvinyl chloride were found to give acceptable binding. The final choice depended on the antigen to be attached. Variations in binding between lots, batches, and types of plastic were found. Well-to-well variation was found to be of greater statistical significance than edge effect and should be a consideration in selection of a plate lot for enzyme-linked immunosorbent assays. Lots of plates should be pretested by the investigator to determine whether there is good binding of the antigen to be used and whether there is low plate-to-plate and well-to-well variation.
Evaluation of the Precept microdilution MIC system for single-drug testing in individual trays
Authors: Lairscey R G , Kelly M T
Published: January 2020

This study presents an evaluation of a commercial system for the MIC testing of single drugs dehydrated in disposable plastic trays (Precept, Austin Biological Laboratories, Inc., Austin, Tex.). The commercial system was compared with a reference agar dilution method, and 203 clinical bacterial isolates were tested by each method. For a total of 767 determinations, there was 94.2% agreement between the two methods, and of the discrepancies encountered, 0.8% were very major, 2.1% were major, and 2.9% were minor. The results suggest that the Precept system may provide a practical and reliable method for MIC determinations of individual antimicrobial agents.
Rapid visual detection of Escherichia coli and Vibrio cholerae Heat-labile enterotoxins by nitrocellulose enzyme-linked immunosorbent assay
Authors: Beutin L , Bode L , Richter T , Peltre G , Stephan R
Published: January 2020

A modification of the enzyme-linked immunosorbent assay for a sensitive and rapid visual detection of heat-labile enterotoxins from Escherichia coli and Vibrio cholerae is described. Small amounts of bacterial supernatant fluids are bound to nitrocellulose filters which are used as sorbents in the nitrocellulose enzyme-linked immunosorbent assay. The test is based on the immunological similarity between V. cholerae and E. coli heat-labile enterotoxins. Six isolates of V. cholerae and 48 isolates of E. coli were examined for heat-labile enterotoxins by the nitrocellulose enzyme-linked immunosorbent assay and the Vero cell bioassay. With some strains, the nitrocellulose enzyme-linked immunosorbent assay was found to be more sensitive for detection of E. coli heat-labile enterotoxin than the Vero cell test. A similar result was obtained by endpoint titration of heat-labile enterotoxin-positive E. coli H10407 culture fluid in both assays. The sensitivity of the nitrocellulose enzyme-linked immunosorbent assay for the detection of purified cholera toxin was at a total level of 1 ng, which is a good result when compared with other serological assays.
Rapid confirmatory identification of Neisseria gonorrhoeae with lectins and chromogenic substrates
Authors: Yajko D M , Chu A , Hadley W K
Published: January 2020

A group of five tests utilizing wheat germ and soybean lectins and chromogenic substrates (orthonitrophenyl-beta-D-galactopyranoside, gamma-glutamyl-beta-naphthylamide, and prolyl-beta-naphthylamide derivatives) was used as a rapid (30-min) method for the identification of Neisseria gonorrhoeae. The rapid method agreed with Minitek test results for all 126 N. gonorrhoeae isolates and all 39 nongonococcal isolates tested. Soybean lectin was useful for the identification of rare strains (4 of 126) of N. gonorrhoeae which are not agglutinated by wheat germ lectin. The chromogenic substrates differentiate N. gonorrhoeae from Neisseria meningitidis, Neisseria lactamica, and other Neisseria species which may grow on Thayer-Martin or other selective media.
Antigen detection for the diagnosis of gonorrhea
Authors: Stamm W E , Cole B , Fennell C , Bonin P , Armstrong A S , Herrmann J E , Holmes K K
Published: January 2020

We compared the diagnostic value of an enzyme immunoassay method for detection of gonococcal antigen in genital secretions with culture results and direct Gram stain for Neisseria gonorrhoeae in 1,171 men and 723 women attending a sexually transmitted disease clinic. When compared with culture results in men, the immunoassay provided a sensitivity of 94% and a specificity of 98% and was essentially equivalent to the urethral Gram stain. The predictive value of a positive immunoassay was 97% in men with a urethral discharge in whom the prevalence of gonorrhea was 36%, and 30% in men without urethral discharge, who had a 2% prevalence of gonorrhea (P less than 0.001). The sensitivity of the immunoassay was 95% in men with and 67% in men without urethral discharge (P less than 0.01). In women, the immunoassay resulted in a sensitivity of 78% and a specificity of 98% compared with cervical culture and had a significantly better sensitivity than the cervical Gram stain (78 versus 48%, P less than 0.001). Analysis of patients with discrepant culture and immunoassay results suggested that most culture-negative, immunoassay-positive patients probably did not have gonorrhea. After treatment, all but 1 of 59 originally culture- and immunoassay-positive patients became negative in both tests by 3 days. Results of the immunoassay were not affected by transport or by refrigeration for up to 30 days.
Rapid and reliable method for production of a specific Paracoccidioides brasiliensis immunodiffusion test antigen
Authors: Blumer S O , Jalbert M , Kaufman L
Published: January 2020

Previously published methods to produce Paracoccidioides brasiliensis antigens for serological tests have yielded antigens of inconsistent quality and have involved the use of special semisynthetic media and growth periods of 1 to 3 months to yield suitable reagents. A simple procedure that uses commercially available potato glucose agar and either SABHI broth (Difco Laboratories) or Trypticase soy broth (BBL Microbiology Systems) inoculated with the mycelial form of P. brasiliensis consistently yielded high-titer antigens in 2 weeks or less. This new method permits the almost exclusive production of an antigen identical to the specific E antigen described by Yarzabal (Yarzabal et al., Sabouradia 14:275-280, 1976) and the apparently equivalent specific antigen 1 described by Restrepo and Moncada (A. Restrepo and L. H. Moncada, Appl. Microbiol. 28:138-144, 1974). In the immunodiffusion test, the rapidly produced antigen demonstrated a sensitivity of 90% by detecting antibody in sera from 103 of 114 proven cases of paracoccidioidomycosis. The specificity of this antigen was 100% because none of 139 sera from patients with heterologous mycotic diseases demonstrated diagnostic precipitins against the P. brasiliensis antigen. In the complement fixation tests, the rapidly produced antigen was not as suitable as the one prepared by the method of Restrepo-Moreno and Schneidau (A. Restrepo-Moreno and J. D. Schneidau, Jr., J. Bacteriol. 93:1741-1748, 1967).
Colony incompatibility studies of enterotoxigenic Escherichia coli O126 isolated during one outbreak
Authors: Bettelheim K A
Published: January 2020

Strains of heat-stable enterotoxin-producing Escherichia coli belonging to O group O126 isolated during an outbreak of gastroenteritis were studied by the colony incompatibility phenomenon. They were compared with other isolates of O126. All of the outbreak strains except one appeared related in these studies and were different from all other strains studied. The one different outbreak strain was isolated 6 weeks after all of the others and may represent some new factor. The study demonstrated the potential usefulness of monitoring strains during an outbreak for relatedness.
Early detection of streptococci in swabs by latex agglutination before culture
Authors: Petts D N
Published: January 2020

A commercial streptococcal grouping system was used to demonstrate streptococcal antigen in swabs before culture. The method detected 81% of the streptococci of groups A, B, C, and G subsequently isolated in culture. The method offers a sensitive and specific method for the early detection of beta-hemolytic streptococci.
Role of recent vaccination in production of false-positive coronavirus antibody titers in cats
Authors: Barlough J E , Jacobson R H , Pepper C E , Scott F W
Published: January 2020

Statistical support was obtained for an association between recent vaccination of cats and the presence of elevated background (i.e., anti-cell culture) reactivity in certain of their sera, as detected with a kinetics-based enzyme-linked immunosorbent assay for coronavirus antibodies, implicating routine vaccination as a potential cause of false-positive antibody test results.
Moellerella wisconsensis, a new genus and species of Enterobacteriaceae found in human stool specimens
Authors: Hickman-Brenner F W , Huntley-Carter G P , Saitoh Y , Steigerwalt A G , Farmer J J , Brenner D J
Published: January 2020

The name Moellerella wisconsensis is proposed for a group of the family Enterobacteriaceae previously called enteric group 46. The species name, wisconsensis, was coined because six of the nine strains were isolated in Wisconsin. M. wisconsensis strains were negative for indole production, Voges-Proskauer, H2S production, urea, phenylalanine deaminase, lysine and ornithine decarboxylases, arginine dihydrolase, gas production from D-glucose, acid production from trehalose, and motility; the strains were positive for methyl red, citrate (Simmons), and acid production from lactose and raffinose and resistant to colistin. DNAs from five strains of M. wisconsensis were highly related (80 to 93% in reactions assayed on hydroxyapatite at 60 degrees C and 78 to 97% at 75 degrees C) to 32P-labeled DNA of the proposed type strain (CDC 2896-78, ATCC 35017). Labeled DNA from this type strain was only 2 to 32% related (at 60 degrees C) to DNA from 49 strains of named and unnamed species of Enterobacteriaceae. Eight of nine M. wisconsensis strains were isolated from human stool samples. Clinical information on one strain was available, and it was found to be associated with a case of diarrhea. On MacConkey agar, colonies of M. wisconsensis were bright red with precipitated bile around them and thus were indistinguishable from Escherichia coli colonies. Future studies should focus on the isolation of this new organism and its relationship to human disease.