bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical and microbiological features of Aeromonas hydrophila-associated diarrhea
Authors: Agger W A , McCormick J D , Gurwith M J
Published: January 2020

The prevalence of Aeromonas hydrophila in stool specimens from patients with diarrhea was studied during 18 months. A. hydrophila was found in 1.1% of patients with diarrhea and in none of 533 control patients (P less than 0.02). Cases were detected 1.5 times more often during the summer months than the winter months, and most occurred in children less than 2 years of age. Clinical features included fever greater than 38 degrees C (55%), abdominal cramps (35%), vomiting (25%), and duration of illness greater than 10 days (50%). Detection of A. hydrophila in stools was facilitated by the use of sheep blood agar with 15 micrograms of ampicillin per ml which was flooded with oxidase reagent after growth. A cytotoxin was produced by 62% of the isolates, and the cytotoxic strains showed positive results in a hemolysin assay and a lysine decarboxylase reaction.
Immunoglobulin M antibodies detected by enzyme-linked immunosorbent assay and radioimmunoassay in the diagnosis of cytomegalovirus infections in pregnant women and newborn infants
Authors: Stagno S , Tinker M K , Elrod C , Fuccillo D A , Cloud G , O'Beirne A J
Published: January 2020

Immunoglobulin M (IgM) antibodies were detected by a commercially available enzyme-Linked Immunosorbent Assay (ELISA) in 36 of 49 (73%) pregnant women with primary cytomegalovirus (CMV) infection. A positive ELISA-IgM result occurred in 10 of 13 patients (77%) assessed within 8 weeks of seroconversion. The sensitivity of the radioimmunoassay (RIA) to identify primary infection in pregnant women was comparable, 78% in general and 86% for women tested within 16 weeks of seroconversion. Of the 36 women with primary infection who had detectable IgM antibodies by ELISA, 25 (69%) were delivered of congenitally infected infants, whereas of the 13 with undetectable IgM antibodies, 7 (54%) transmitted the infection in utero. IgM antibodies were detected by ELISA in only 5 of 43 (11%) women who experienced a recurrence of CMV which either did or did not result in congenital infection. RIA was less likely to measure CMV-specific IgM in recurrent infection, inasmuch as 1 of 19 (5.2%) women with proven recurrent infection had detectable IgM antibody, giving RIA a better specificity for primary infection. Specific IgM antibodies were detected by ELISA in 42 of 61 (69%) babies congenitally infected with CMV and in 4 of 70 (5.7%) uninfected control newborn infants. The RIA was superior for diagnosis of congenital CMV infection, with a sensitivity of 89% and a specificity of 100%. The lower sensitivity of the ELISA-IgM occurred in the category of congenitally infected infants born to mothers with recurrent infection (43%), a group that is at the lowest risk of disease or to develop sequelae. This commercially available ELISA-IgM could be used in combination with a CMV-specific IgG test for monitoring women during pregnancy for primary infection.
Evaluation of a lysis direct plating method for pediatric blood cultures
Authors: Welch D F , Scribner R K , Hensel D
Published: January 2020

The Isolator 1.5 Microbial tube (E. I. du Pont de Nemours & Co., Inc., Wilmington, Del.) is a commercially available blood culture system for use in pediatrics. The methodology is based on blood lysis followed by direct plating of the sample on culture media to detect bacteria and fungi. Comparative recovery rates of pathogens from blood collected in this and a conventional broth system were similar. The Isolator detected 104 of 120 clinically significant isolates, whereas 106 of 120 isolates were detected by the broth system. The major advantage of the Isolator methodology was early detection of septicemia. Initial detection of gram-negative bacteria occurred an average of 14.2 h earlier by the Isolator system than by the conventional broth method. The Isolator also permitted quantitation of bacteremia and fungemia. Probable contaminants were recovered from 10.0% of the cultures processed by the Isolator, but steps which could be taken to minimize this problem were identified. The Isolator is a useful method for pediatric blood cultures.
Comparison of enzyme immunoassay and gas-liquid chromatography for the rapid diagnosis of invasive candidiasis in cancer patients
Authors: de Repentigny L , Marr L D , Keller J W , Carter A W , Kuykendall R J , Kaufman L , Reiss E
Published: January 2020

Three proposed quantitative markers for candidiasis, arabinitol, mannose, and mannan in serum, are compared in 50 normal blood donors and 38 high-risk patients, 23 with and 15 without invasive candidiasis. Arabinitol concentrations in serum, the arabinitol/creatinine ratio, and mannose concentrations in serum were significantly greater in the 15 patients without candidiasis than in the normal blood donors (P less than 0.05). The sensitivities and specificities were 26 and 87% for arabinitol, 13 and 93% for the arabinitol/creatinine ratio, and 39 and 87% for mannose. On the other hand, mannan concentrations in serum were less than 1 ng/ml in normal blood donors and patients without candidiasis (P = 0.344), and the sensitivity and specificity were 65 and 100%, respectively. Of 23 patients with proven or probable candidiasis, 16 had mannan levels in serum greater than the mean + 2 standard deviations (0.46 ng/ml) for the 15 controls. In 16 patients with invasive candidiasis and positive blood cultures for the Candida spp., only 13 had elevated levels of at least one of the three markers. The arabinitol/creatinine ratio, the mannose level, and the mannan level became elevated an average of 4 days before, 1 day before, and on the same day that the blood cultures were drawn, respectively. Conversely, mannan was detected in the sera of six of seven patients with invasive candidiasis and negative blood cultures. We conclude that the best approach to diagnosing invasive candidiasis involves obtaining blood cultures and carrying out serial assays for mannan in serum.
Bactericidal activity of antiseptics against methicillin-resistant Staphylococcus aureus
Authors: Haley C E , Marling-Cason M , Smith J W , Luby J P , Mackowiak P A
Published: January 2020

Various commonly used antiseptics were tested against three strains of methicillin-resistant Staphylococcus aureus (MRSA) at stock strength and in serial 10-fold dilutions. The stock solutions of 4% chlorhexidine gluconate-alcohol (Hibiclens), 1% p-chloro-m-xylenol (Acute-Kare), and 3% hexachlorophene (Phisohex) produced 2-log reductions of MRSA after a 15-s exposure, but even after 240 s, these solutions failed to kill all the MRSA. Povidone-iodine (Betadine) solution was maximally effective at the 1:100 dilution, killing all the MRSA within 15 s; other dilutions were less effective, though each killed the MRSA within 120 s. Similar results were obtained with three different strains of methicillin-susceptible S. aureus. Thus, of the four most commonly used antiseptics, povidone-iodine, when diluted 1:100, was the most rapidly bactericidal against both MRSA and methicillin-susceptible S. aureus.
Second serogroup of Legionella feeleii strains isolated from humans
Authors: Thacker W L , Wilkinson H W , Plikaytis B B , Steigerwalt A G , Mayberry W R , Moss C W , Brenner D J
Published: January 2020

Three strains of Legionella feeleii from patients with pneumonia (425-MI-H, 691-WI-H, and 693-WI-H) and one environmental strain (713-MI-E) received at the Centers for Disease Control for reference diagnostic testing were compared with the type strain WO-44C-C3 (ATCC 35072) by DNA hybridization, chemical analysis of cellular fatty acids and ubiquinones, biochemical tests, and serological characteristics. All four isolates were assigned to the L. feeleii species on the basis of DNA hybridization results. However, strains 691-WI-H and 693-WI-H were serologically distinct from strain WO-44C-C3, as shown by their minimal reactivity (1 to 2+) with a direct immunofluorescence conjugate prepared against L. feeleii serogroup 1 (strain WO-44C-C3). Therefore, strains 691-WI-H and 693-WI-H were placed in a new L. feeleii serogroup (serogroup 2). The reference strain of L. feeleii serogroup 2 is 691-WI-H (ATCC 35849).
Streptococcus pneumoniae type 16A, a hitherto undescribed pneumococcal type
Authors: Austrian R , Boettger C , Dole M , Fairly L , Freid M
Published: January 2020

Some properties of a newly recognized pneumococcal capsular serotype, type 16A, are described, bringing the number of capsular types characterized to 84.
Measurement of growth-inhibiting (bactericidal) antibodies in patients with meningococcal meningitis and in subjects immunized with meningococcal polysaccharide vaccine by a [3H]thymidine assay
Authors: Hassan-King M , Greenwood B M , Whittle H C
Published: January 2020

We measured bactericidal antibodies against meningococci by a method which depends on the inhibition of [3H]thymidine uptake by bacteria in the presence of antibody and complement. A significant increase in antibody activity was found in sera from patients who had recovered from group A meningococcal meningitis (mean inhibition, 38.9 +/- 4.4%) compared with antibody activity present in sera from patients in the acute phase (mean inhibition, 7.0 +/- 2.4%) (P less than 0.001). Similarly, a significant increase in inhibitory activity against group C meningococci was observed 2 weeks after immunization with group C polysaccharide. A close correlation was obtained between the results of the thymidine assay and of a standard colony-counting method and hemagglutination assay. The assay is readily applicable to testing large numbers of samples.
Identification of endemic foci of Lyme disease: isolation of Borrelia burgdorferi from feral rodents and ticks (Dermacentor variabilis)
Authors: Anderson J F , Johnson R C , Magnarelli L A , Hyde F W
Published: January 2020

Borrelia burgdorferi, the etiological agent of Lyme disease, was isolated from the blood, kidneys, spleens, eyes, or livers of white-footed mice (Peromyscus leucopus) (n = 19 of 22) and from the blood, kidneys, or spleens of eastern chipmunks (Tamias striatus) (n = 2 of 2) captured at three foci for Lyme disease in eastern Connecticut. These bacteria were cultured most frequently from spleens (n = 19) and kidneys (n = 15). B. burgdorferi persisted in one mouse for at least 60 days. One spirochetemic mouse had infected Ixodes dammini and Dermacentor variabilis larvae attached, suggesting that these ticks may have acquired spirochetes from the host. Spirochetes isolated from P. leucopus, T. striatus, and D. variabilis larvae were serologically and genetically indistinguishable from reference B. burgdorferi isolates. We conclude that isolation of spirochetes from feral rodents is a method for identifying endemic areas of Lyme disease.
Clinical evaluation of three rapid methods for the detection of significant bacteriuria
Authors: Bixler-Forell E , Bertram M A , Bruckner D A
Published: January 2020

Random urine specimens (848) were screened for significant bacteriuria by using the 30-min Lumac (3M, St. Paul, Minn.), the 2-min Bac-T-Screen (Marion Laboratories, Inc., Kansas City, Mo.), and the 13-h AutoMicrobic system (AMS) urine identification card (Vitek Systems, Inc., Hazelwood, Mo.). MacConkey and 5% sheep blood agar plates were inoculated with a 10(-4) dilution of urine and used for the reference method. Bac-T-Screen results were uninterpretable for 9.1% of the specimens owing to either urine sample pigmentation (5.3%) or clogging of the filter (3.8%). Screen-negative urine specimens made up 49.6, 57.2, and 48.5% of the total number of specimens evaluated with AMS, Lumac, and Bac-T-Screen, respectively. False-positive results with Lumac and Bac-T-Screen were 20.6 and 22.3%, respectively. False-negative results for cultures with greater than or equal to 10(4) CFU/ml were 22.0% with AMS, 29.4% with Lumac, and 25.5% with Bac-T-Screen, and false-negative results for cultures with greater than or equal to 10(5) CFU/ml were 29.6% with AMS, 9.9% with Lumac, and 7.0% with Bac-T-Screen. For each system, greater than 70% of false-negatives at greater than or equal to 10(5) CFU/ml consisted of mixed or pure cultures of common contaminants. With any of these screening methods, a clinically significant isolate at greater than or equal to 10(5) CFU/ml would rarely be missed (less than or equal to 1.7% for all systems). A cost-effective and rapid approach to urine microbiology could consist of screening out negative specimens by either Lumac or Bac-T-Screen and processing only screen-positive specimens by the AMS.
Risk of group A meningococcal disease: bacterial interference and cross-reactive bacteria among mucosal flora
Authors: Filice G A , Hayes P S , Counts G W , Griffiss J M , Fraser D W
Published: January 2020

During outbreaks of group A meningococcal disease in Seattle, Wash., and Portland, Oreg., we studied the mucosal flora of the affected population and comparison groups to identify possible determinants of susceptibility and resistance to disease. Antimeningococcal immunoglobulin A can block the bactericidal activity of specific antibodies of other classes and has been associated with susceptibility in adults. We used immunoprecipitation and fluorescent-antibody techniques to detect mucosal microorganisms cross-reactive with group A meningococci that might have stimulated such antibodies. Cross-reactive strains of Bacillus pumilus and Streptococcus faecalis were found. Bacterial interference on mucosal surfaces has been shown to reduce susceptibility to other pathogens. With an agar overlay technique, we sought nasopharyngeal microorganisms that inhibited the growth of group A meningococci. Forty-five percent of subjects carried inhibitory strains representing at least nine different species. Inhibitory strains were less common (32%) in residents from "skid row" areas (see D.J. Bogue, Skid Row in American Cities, University of Chicago Press, for a comprehensive definition of these areas) than in a comparison group that did not experience meningococcal disease (61%), suggesting that their presence may be associated with resistance to acquisition of meningococci or to meningococcal disease.
Factors affecting the detection of enteroviruses in cerebrospinal fluid with coxsackievirus B3 and poliovirus 1 cDNA probes
Authors: Rotbart H A , Levin M J , Villarreal L P , Tracy S M , Semler B L , Wimmer E
Published: January 2020

Enteroviruses are common pathogens of meningitis and encephalitis, and infections are often difficult to distinguish clinically from bacterial and herpetic infections of the central nervous system. An array of enteroviruses added to cerebrospinal fluid in reconstruction experiments were detected by a dot hybridization assay. Optimal handling and processing conditions for infected cerebrospinal fluid were established, and the effect on the hybridization reaction of humoral and cellular components of the inflammatory response was determined. Six hybridization probes, derived from poliovirus 1 and coxsackievirus B3, were then tested, singly and in combinations, to optimize the sensitivity and spectrum of the assay. Implications for enteroviral taxonomy based on these experiments are discussed.
Comparison of radiometric and conventional culture systems in detecting Haemophilus influenzae type b bacteremia in rats
Authors: Mitchell M J , Zwahlen A , Elliott H L , Ford N K , Charache F P , Moxon E R
Published: January 2020

To compare the efficiency of detecting Haemophilus influenzae type b bacteremia by the BACTEC radiometric system (RS; Johnston Laboratories, Inc., Towson, Md.) and a conventional Trypticase soy broth (BBL Microbiology Systems, Cockeysville, Md.) blood culture system (TSB), we developed an in vivo model of bacteremia in rats. After intravenous injection of 50 to 200 CFU into adult rats, there was a linear logarithmic increase in CFU per milliliter of rat blood during the first 10 h (r = 0.98), allowing accurate prediction of the level of bacteremia with time. Culture bottles were inoculated with 0.5 ml of blood obtained by cardiac puncture and processed as clinical samples in the microbiology laboratory with our RS and conventional protocols. We found the following. (i) The first detection of bacteremia by RS was similar to that by TSB if a Gram stain of the TSB was done on day 1 and was superior if that smear was omitted (P less than 0.01). (ii) The detection times in both systems were comparable at different magnitudes of bacteremia (10(1) to 10(4) CFU/ml). (iii) Supplementation of inoculated bottles with 2 ml of sterile rat blood interfered with Gram stain detection in TSB but resulted in increased 14CO2 production in RS. (iv) No difference in detection time was found between RS and TSB for four different clinical isolates. These studies show that, in a biologically relevant model, the detection of positive blood cultures for H. influenzae type b by RS was comparable to or better than detection by TSB when blood was processed analogously to clinical specimens.
Evaluation of a one-hour test for the identification of Neisseria species
Authors: Lairscey R C , Kelly M T
Published: January 2020

This study presents an evaluation of the RIM-N kit (Austin Biological Laboratories, Inc., Austin, Tex.), a commercial system for rapid identification of Neisseria spp. and Branhamella catarrhalis. The system was compared with the cystine-Trypticase (BBL Microbiology Systems, Cockeysville, Md.) agar method; 218 isolates were tested by each method. There was 96% agreement between the two methods, and only nine discrepancies were encountered. The results suggest that the RIM-N kit may provide a rapid and reliable method for identifying Neisseria spp. and B. catarrhalis.
Modified trichrome staining technique with a xylene substitute
Authors: Neimeister R , Logan A L , Egleton J H
Published: January 2020

Hemo-De was evaluated and found to be a suitable replacement for xylene in the Wheatly trichrome staining of polyvinyl alcohol-fixed fecal smears used in the microscopic identification of intestinal protozoans.
Rapid, automated identification of novobiocin-resistant, coagulase-negative staphylococci
Authors: Mendes C M , Siqueira L F , Francisco W
Published: January 2020

A modified automated method that uses the MS-2 system (Abbott Laboratories, Diagnostics Div., Irving, Tex.) to verify the reaction of coagulase-negative staphylococci to novobiocin is described. This technique permits the testing of a great number of specimens in an average time of 99 min and results in a 100% match with the traditional method of culturing.
Occurrence of plasmids and antibiotic resistance among Campylobacter jejuni and Campylobacter coli isolated from healthy and diarrheic animals
Authors: Bradbury W C , Munroe D L
Published: January 2020

Serologically defined strains of Campylobacter jejuni and Campylobacter coli from healthy and diarrheic animals were examined for the occurrence of plasmid DNA in association with the antibiotic susceptibility of the bacterial host and the health status of the animal host. Of all campylobacter organisms surveyed, 53% (116 of 200) contained plasmid DNA. A plasmid occurrence rate of 73.8% was obtained for C. coli from healthy pigs, contrasted by lower plasmid occurrence rates for C. coli from diarrheic pigs (30%) and from all diarrheic animals (21.4%). For C. jejuni, in contrast, only 13.6% of healthy cattle contained plasmid DNA, contrasted by a higher plasmid occurrence rate of 31.2% from diarrheic cattle. A high plasmid occurrence rate of 75.8% was observed for C. jejuni from healthy chickens. Campylobacter plasmids ranged in size from less than or equal to 1 to 86 megadaltons. Antibiotic susceptibility for 52 animal isolates (excluding chickens) indicated that most isolates were susceptible to kanamycin, erythromycin, gentamicin, tetracycline, and compound sulfonamide, whereas few were susceptible to bacitracin (19.2%); approximately half were susceptible to ampicillin (55.8%) and streptomycin (51.9%), and no isolates were susceptible to penicillin G. More isolates containing plasmids were resistant to ampicillin, tetracycline, and gentamicin than were isolates not carrying plasmids, there being a statistically significant difference for tetracycline and gentamicin, which suggested that these two antibiotics were probably plasmid mediated. The antibiotic susceptibility patterns of 21 chicken isolates of C. jejuni, by contrast, were different in that most were susceptible to ampicillin in addition to kanamycin, erythromycin, and gentamicin, whereas few wer susceptible to compound sulfonamide, streptomycin, and tetracycline in addition to penicillin G and bacitracin. A 30- or 39-megadalton plasmid, or both, common to many of the chicken isolates was usually associated with tetracycline resistance.
Immobilization of microorganisms for detection by solid-phase immunoassays
Authors: Ibrahim G F , Lyons M J , Walker R A , Fleet G H
Published: January 2020

Several cultures of gram-negative and gram-positive bacteria were successfully immobilized with titanous hydroxide. The immobilization efficiency for the microorganisms investigated in saline and broth media ranged from 80.2 to 99.9%. The immobilization of salmonellae was effective over a wide pH range. The presence of buffers, particularly phosphate buffer, drastically reduced the immobilization rate. However, buffers may be added to immunoassay systems after immobilization of microorganisms. The immobilization process involved only one step, i.e., shaking 100 microliter of culture with 50 microliter of titanous hydroxide suspension in polystyrene tubes for only 10 min. The immobilized cells were so tenaciously bound that vigorous agitation for 24 h did not result in cell dissociation. The nonspecific binding of 125I-labeled antibody from rabbits and 125I-labeled protein A by titanous hydroxide was inhibited in the presence of 2% gelatin and amounted to only 5.6 and 3.9%, respectively. We conclude that this immobilization procedure is a potentially powerful tool which could be utilized in solid-phase immunoassays concerned with the diagnosis of microorganisms.
Total volume culture technique for the isolation of microorganisms from continuous ambulatory peritoneal dialysis patients with peritonitis
Authors: Dawson M S , Harford A M , Garner B K , Sica D A , Landwehr D M , Dalton H P
Published: January 2020

A total volume method of culturing dialysis fluid from continuous ambulatory peritoneal dialysis patients during episodes of peritonitis was developed. Concentrated culture media stored in small blood transfer bags were added directly to the drained dialysate exchange bags by the same technique used to carry out the dialysate exchange. The exchange bag with the added culture medium was incubated at 35 degrees C and observed for turbidity. Seventy-eight dialysis exchange bags from patients without clinical peritonitis (negative controls) and forty-eight dialysis exchange bags from patients with clinical peritonitis were cultured. Bacteria were recovered from all cultures of patients with clinical peritonitis (100% sensitivity) and from five cultures of negative control fluids (94% specificity). Of these isolates, 86% were gram positive, and 14% were gram negative. This technique represents an advance over previously described culture techniques in its ability to isolate the causative organism(s) in cases of peritonitis in continuous ambulatory peritoneal dialysis patients.
Isolation of Legionella pneumophila from blood with the BACTEC system: a prospective study yielding positive results
Authors: Rihs J D , Yu V L , Zuravleff J J , Goetz A , Muder R R
Published: January 2020

In a prospective study of 16 patients with Legionnaires disease confirmed by cultural isolation of Legionella pneumophila from the respiratory tract, 38% (6 of 16) had positive blood cultures. Daily subcultures were made onto buffered charcoal-yeast extract plates from 6B aerobic and 7C anaerobic BACTEC blood culture bottles (Johnston Laboratories, Inc., Towson, Md.). Isolation of L. pneumophila was achieved from both aerobic and anaerobic bottles. L. pneumophila growth indices failed to exceed the BACTEC threshold limits; thus, the organism would have been overlooked despite its presence in the blood culture bottles. Bacteremic patients had statistically significant higher quantities of L. pneumophila isolated from sputum and visualized on direct fluorescent antibody stains. Thus, the potential exists for improved diagnosis of Legionella infection by a relatively noninvasive procedure (blood culture) with an instrument already in use in many hospital laboratories.
Examination of the Rotazyme II enzyme immunoassay for the diagnosis of rotavirus gastroenteritis
Authors: Chernesky M , Castriciano S , Mahony J , DeLong D
Published: January 2020

Rotazyme II, which is a shorter version of Rotazyme (less than 3 h), was compared with electron microscopy and Rotazyme for sensitivity and specificity on 229 human stool specimens. Compared with electron microscopy, the newer assay was found to be 99.4% sensitive and 97.3% specific for an overall agreement of 98.7%. After resolution of discordant results by blocking tests, the Rotazyme II enzyme immunoassay was shown to be more sensitive than electron microscopy and, therefore, 100% specific.
Meningitis caused by Gordona aurantiaca (Rhodococcus aurantiacus)
Authors: Prinz G , Bán E , Fekete S , Szabó Z
Published: January 2020

In a case of hairy cell leukemia, Gordona aurantiaca (Rhodococcus aurantiacus) was isolated from cerebrospinal fluid as the pathogen responsible for lethal infection of the central nervous system. The pathogen had been isolated previously from one case of pulmonary infection process only.
Enzyme-linked immunosorbent assay for detection of antibodies to Staphylococcus aureus cell walls in experimental osteomyelitis
Authors: Jacob E , Arendt D M , Brook I , Durham L C , Falk M C , Schaberg S J
Published: January 2020

An enzyme-linked immunosorbent assay was used to evaluate and compare the immunoglobulin G antibody response to Staphylococcus aureus cell walls of rabbits with either chronic staphylococcal osteomyelitis or subcutaneous abscesses. Osteomyelitis of the femur was produced by the intramedullary application of a sclerosing agent (3% sodium tetradecyl sulfate) and S. aureus. Radiographic evidence of osteomyelitis was observed in 10 of the 13 animals that survived the 10-week experimental period, and the diagnosis was confirmed by histopathology in 8 of the 10 instances. Abscess formation was initiated in a separate group of rabbits by the subcutaneous injection of S. aureus cells. All 10 of these rabbits subsequently developed abscesses, which usually resolved spontaneously within 3 to 5 weeks. Elevated levels of immunoglobulin G antibodies to the cell wall antigen were detected in 7 of 10 rabbits with osteomyelitis at 21 days postinfection, and these animals continued to display high antibody levels even at 59 days postinfection. In contrast, elevated levels of anti-cell-wall antibodies were only detected in 1 of 10 rabbits with subcutaneous abscesses. The enzyme-linked immunosorbent assay was found to be a rapid and sensitive serological technique for the detection of cell wall antibodies in this experimental osteomyelitis model and may be useful for the diagnosis of staphylococcal bone infections in humans.
Comparison of the Penner and Lior methods for serotyping Campylobacter spp
Authors: Patton C M , Barrett T J , Morris G K
Published: January 2020

We compared two Campylobacter serotyping systems by using 1,405 isolates of Campylobacter collected from human, animal, and environmental sources during epidemiologic investigations and special studies. We found 96.1% of isolates to be typable by the Penner method for heat-stable antigens, which involved the use of an indirect hemagglutination technique, and 92.1% of isolates to be typable by the Lior method for heat-labile antigens, which involved the use of a slide agglutination technique and absorbed antisera. Absorbed antisera were not required for the Penner method, making that method less difficult to implement. The Lior method was simpler to perform and gave more rapid results than did the Penner method. Cultures frequently reacted in multiple antisera with the Penner method, whereas multiple reactions were rare with the Lior method. Thus, results were easier to interpret with the Lior system. Strains of a single serotype in one system were sometimes found to be multiple serotypes in the other system; hence, the two methods have the potential to be complementary. Both systems were comparable in serotyping isolates from human and nonhuman sources and for evaluating the relationship of strains collected during outbreak investigations.
Quantification of medically important Candida species and Torulopsis glabrata by a spiral inoculation system: correlation with pour plate and spread plate methods
Authors: Walsh T J , Venanzi W E , Dixon D M
Published: January 2020

A new method of quantifying Candida spp. and Torulopsis glabrata suspensions, the spiral inoculation system, was studied to compare its accuracy, efficiency, and cost with the standard pour plating and spread plating methods. Concentrations of yeast suspensions ranging from 10(2) to 10(5) CFU were quantified simultaneously by the three methods. Linear regression analysis was used to determine the correlation between the spiral inoculation system and pour plating and between the spiral system and spread plating for Candida albicans, C. tropicalis, C. krusei, and T. glabrata. Spiral system and pour plating techniques correlated very well for all species, as did the spiral system and spread plating techniques (r greater than 0.95; P greater than 0.001).
Comparison of API 20E, API rapid E, and API rapid NFT for identification of members of the family Vibrionaceae
Authors: Overman T L , Kessler J F , Seabolt J P
Published: January 2020

Sixty isolates, from nine species of the family Vibrionaceae, were tested by the API 20E, API Rapid E, and API Rapid NFT systems. Results were compared with those obtained with standard biochemicals. Included were 7 Aeromonas caviae isolates, 27 Aeromonas hydrophilia isolates, 10 Aeromonas sobria isolates, 3 Plesiomonas shigelloides isolates, 3 Vibrio alginolyticus isolates, 3 Vibrio cholerae isolates, 1 Vibrio fluvialis isolate, 5 Vibrio parahaemolyticus isolates, and 1 Vibrio vulnificus isolate. The API 20E correctly identified all the isolates within 24 h. The API Rapid E correctly identified only 77%, misidentified 8%, and failed to identify 2% of the isolates in 4 h. The remaining 13% of the isolates gave a low selectivity identification, with one of the choices being correct. The API Rapid NFT correctly identified 87%, misidentified 5%, gave a low selectivity identification for 8% of the isolates, and in some instances, required up to 48 h of incubation. The API 20E is a valid system for use in the identification of the more commonly occurring members of the family Vibrionaceae and the most accurate and efficient of the three systems tested.
Disk susceptibility of ofloxacin, a new carboxyquinolone
Authors: Mandell W , Neu H C
Published: January 2020

Ofloxacin, a fluorinated carboxyquinolone, was tested against 485 clinical isolates, and the MICs and disk inhibitory zones were correlated. A critical zone of greater than or equal to 19 mm and an MIC of less than or equal to 2 micrograms/ml indicate susceptibility. An MIC of 4 micrograms/ml and a zone size of 16 to 18 mm is intermediate, and an MIC of greater than or equal to 8 micrograms/ml with a zone size of less than 15 mm indicates resistance. Alternatively, organisms inhibited by an MIC of less than or equal to 4 micrograms/ml with a critical zone diameter of greater than or equal to 15 mm could be considered susceptible. By either of these criteria, major errors in judging susceptibility or resistance are less than 1%.
Variable phenotypes of Providencia stuartii due to plasmid-encoded traits
Authors: Mobley H L , Chippendale G R , Fraiman M H , Tenney J H , Warren J W
Published: January 2020

Weekly urine specimens from 51 long-term catheterized patients yielded 699 isolates of Providencia stuartii. Urease-positive strains represented 23.7% (166) of the isolates, sucrose-positive strains represented 24.5% (171), and lactose-utilizing strains represented 0.7% (5). Urease and sucrose traits were transferred by conjugation to Escherichia coli via an 82-kilobase plasmid; lactose fermentation was transferred by a 150-kilobase plasmid.
Cefotiam susceptibility testing criteria
Authors: Fuchs P C , Barry A L , Jones R N , Thornsberry C
Published: January 2020

Interpretive zone size breakpoints for diffusion tests with 30-micrograms cefotiam disks are diameters of greater than or equal to 18 mm for susceptible and less than or equal to 14 mm for resistant strains. The standard control strains Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923 should both give zones 27 to 33 mm in diameter. Tests with 579 clinical isolates yielded an unacceptably high rate of very major discrepancies between disk tests and microdilution tests; such discrepancies were especially common among Enterobacter spp. Additional studies support the concept that standard microdilution tests and standard disk diffusion tests may fail to detect a potential for resistance among some microorganisms.
Microneutralization test for respiratory syncytial virus based on an enzyme immunoassay
Authors: Anderson L J , Hierholzer J C , Bingham P G , Stone Y O
Published: January 2020

Virus infectivity and antibody neutralization titers for respiratory syncytial virus were determined in cell cultures in microtiter plates. After an appropriate incubation period, the cells were fixed, and an enzyme-linked immunosorbent assay was performed directly in the microtiter plates for detection of virus. Results could be read and recorded automatically, which is especially helpful when running large numbers of tests.
Supplementary rapid biochemical test panel for the API 20E bacterial identification system
Authors: Edinger R C , Migneault P C , Nolte F S
Published: January 2020

The API 20E Analytical Profile Index typically suggests three or four conventional biochemical tests to complete the identification of strains either identified to genus only or that have multiple genera consistent with the profile number. We compiled a simple panel of eight rapid (4-h) tests that can substitute for the supplementary biochemical tests recommended by Analytab Products (Plainview, N.Y.). The rapid test panel (RTP) consisted of adonitol, cellobiose, lactose, raffinose, rhamnose, and xylose utilization, lysine decarboxylase activity, and motility. A total of 114 consecutive clinical isolates that required additional tests to complete the identifications were each tested with the complete RTP, as well as with the recommended conventional biochemicals. All discordant identifications were resolved by using an expanded series of conventional biochemical tests. Overall, 110 (96%) strains were identified to the correct genus, and 109 (95%) strains were identified to the correct species by using the RTP, as compared with 105 (92%) identified to the correct genus and 90 (79%) identified to the correct species with the recommended tests. The identifications based on the two supplementary test systems did not agree for 7 (6.1%) strains. Four discrepancies were resolved in favor of the RTP, and three were resolved in favor of the recommended tests. We were unable to identify five (4.4%) strains with the recommended tests and only one (0.9%) with the RTP. A majority (86%) of the test strains were identified to the species level with the RTP after only 4 h of incubation.
Variation in complement fixation test results with three Histoplasma capsulatum yeast phase antigens
Authors: Johnson J E , Goodman N L
Published: January 2020

Antigens derived from three different yeast strains of Histoplasma capsulatum (GW and VC used by the Veterans Administration Serology Reference Laboratory and the Centers for Disease Control reference antigen, A811) were compared with each other to determine their equivalency. Results from 200 sera, tested concurrently by the Serology Reference Laboratory and the University of Kentucky Mycoserology Laboratory, indicated that the VC yeast antigen gave better correlation to the A811 antigen than did the GW antigen.
Specific detection and typing of adenovirus types 40 and 41 in stool specimens by dot-blot hybridization
Authors: Kidd A H , Harley E H , Erasmus M J
Published: January 2020

A dot-blot hybridization test was developed which allowed the direct detection of fastidious enteric adenovirus DNA in stool specimens from children with diarrhea and simultaneous typing of the viruses as adenovirus type 40 (Ad40) or Ad41. Cloned PstI fragments of Ad40 and Ad41 were used as 32P-labeled probes in the test, which allowed detection of picogram quantities of viral DNA in 20 to 40 microliter of stool suspension. Results were obtained within 48 h. The type specificity of the test was evaluated with 76 specimens known to contain either Ad40 or Ad41 by restriction enzyme analysis. Sixty-one specimens had sufficient DNA to be detected without any removal of protein. Thirty-one adenoviruses were typed as Ad40, and 30 were typed as Ad41, giving 100% correlation with the results of restriction enzyme analysis. The other 15 specimens were detected and typed as Ad40 or Ad41 only after removal of protein by a phenol extraction method. The dot-blot hybridization method is particularly useful for identifying those Ad40 and Ad41 strains which defy all attempts at culture and will be a useful tool in the epidemiology of fastidious enteric adenovirus infections.
Comparison of monoclonal antibody staining and culture in diagnosing cervical chlamydial infection
Authors: Lipkin E S , Moncada J V , Shafer M A , Wilson T E , Schachter J
Published: January 2020

We compared a fluorescein-conjugated monoclonal antibody (FA) direct specimen test (MicroTrak; Syva Co., Palo Alto, Calif.) with culture (TC) in McCoy cells (vials, with blind passage and iodine staining of inclusions) for diagnosis of Chlamydia trachomatis infection in the cervix. Duplicate specimens were collected from 1,230 women, but for 262 of these subjects, both results were unavailable (150 FA smears were inadequate, indicating a need for clinical training in specimen collection), leaving 968 comparisons. Prevalence of chlamydiae by culture was 13% (126/968). Compared with TC results, the sensitivity of FA was 70% (88/126) and the specificity was 94% (795/842). There was a 91% agreement (883/968). The predictive value of a positive FA test was 65% (88/135), and that of a negative FA was 95% (795/833). We reexamined 38 smears for which paired results were discrepant, and the reread would have changed the result in only 5 of these. TC is less than 100% sensitive and some FA-positive, TC-negative specimens represent positive specimens not detected by TC. Unfortunately, it is not possible to identify which results in this group are truly false-positive. Clearly, the FA procedure has a performance profile which would make it a useful tool in screening high-risk populations (particularly when TC is not available) but it is less suited to screening low-risk populations, for which false-positive results are more important. The greater utility of the FA procedure in a venereal disease clinic was confirmed by testing 172 evaluable specimen pairs, of which 34 (20%) were Chlamydia isolate positive. The FA sensitivity was 76% (26/34) and specificity was 96% (133/138), giving a predictive value of 84% (26/31) for a positive test.
Spurious sulfamethoxazole-trimethoprim resistance of Salmonella typhi
Authors: Escamilla J , Kilpatrick M E , Ugarte H F
Published: January 2020

Several studies have identified thymidine excess in susceptibility test media as the cause of spurious resistance of various bacteria to sulfamethoxazole-trimethoprim. We document the phenomenon in Salmonella typhi and Salmonella paratyphi-A and demonstrate its occurrence in 3 of 17 (18%) lots of Mueller-Hinton agars now in use in major medical laboratories in Lima, Peru. The findings are particularly significant because sulfamethoxazole-trimethoprim is an important alternative to chloramphenicol or ampicillin for the treatment of typhoid and paratyphoid fevers.
Enzyme-linked immunosorbent assay for detection of streptolysin O antibodies
Authors: Reitano M , Pisano M A , Eriquez L A , D'Amato R F
Published: January 2020

An enzyme-linked immumosorbent assay (ELISA), based upon the detection of streptolysin O antibodies in human sera, was developed. Disposable polystyrene tubes, sensitized with streptolysin O antigen, were used as the test vehicles. Corresponding antibodies, present in test sera, were detected by binding of the antibodies to goat anti-human immunoglobulin G conjugated to horseradish peroxidase. Demonstration of bound conjugate was accomplished by monitoring peroxidase activity spectrophotometrically at 450 nm, using 5-aminosalicylic acid as the indicator. A total of 97 human sera, previously analyzed by means of the anti-streptolysin O titration technique, were evaluated with the ELISA procedure. A direct quantitative relationship, found to be statistically significant, was demonstrated between Todd units and absorbance values obtained with ELISA.
An enzyme immunoassay for immunoglobulin M antibodies to Toxoplasma gondii which is not affected by rheumatoid factor or immunoglobulin G antibodies
Authors: Lin T M , Chin-See M W , Halbert S P , Joseph J M
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) for total antibodies to Toxoplasma gondii was modified to measure specific immunoglobulin M (IgM) antibodies. The assay requires three incubation periods totaling 2 h and enzyme-labeled-heavy-chain-specific antibodies to human IgM. The objective read-out in absorbance was normalized to percent of a standardized positive control for interpretations. No difference was observed between the assay results with or without previous absorption of the samples by Staphylococcus aureus protein A to remove most of the IgG antibodies. Addition of serum containing very high levels of IgG antibodies to another containing both IgG and IgM antibodies did not change the IgM assay values for the latter. None of the 22 sera containing high levels of IgM rheumatoid factor (RF) gave positive ELISA IgM results, even though 8 of them also had high levels of IgG toxoplasma antibodies. Mixtures of sera containing high concentrations of RF with sera having high levels of IgG toxoplasma antibodies also failed to show any false-positive reactions in the IgM toxoplasma assay. Thus, this ELISA for T. gondii IgM antibodies was not affected by IgG toxoplasma antibodies and RF.
Evaluation of a commercial gene probe for identification of Legionella cultures
Authors: Wilkinson H W , Sampson J S , Plikaytis B B
Published: January 2020

Confirmation of a culture as Legionella when it is unreactive with available serologic reagents involves tests that are impractical in most clinical laboratories. A nucleic acid probe that hybridizes only to members of the genus Legionella was recently prepared for marketing by Gen-Probe, Inc., San Diego, Calif. We tested 215 Legionella strains, representing 22 species, and 84 non-Legionella strains, representing 17 bacterial genera, with the Gen-Probe kit. All but four Legionella strains (L. bozemanii, less than 2% of total) and no heterologous strains gave positive test results. We conclude that the Legionella gene probe is a valuable addition to existing diagnostic tests for Legionella organisms.
Microbiological assessment of 24- and 48-h changes and management of semiclosed circuits from ventilators in a neonatal intensive care unit
Authors: Malecka-Griggs B
Published: January 2020

The contamination of semiclosed disposable circuits of Healthdyne and Bourns ventilators was studied in a newborn intensive care unit over a 2-year period. A total of 379 fluid samples was obtained from inspiratory and expiratory tubing condensates and traps and from thermal humidifier columns fed with prefilled containers of sterile water. In addition, 100 tryptic soy agar plates were exposed to the exhalation mist of the circuits sampled. With 24-h changes of circuits a 2.5% contamination rate was observed (phase I). In an effort to contain costs, circuits were changed every 48 h (phase II); the concentration of potential pathogens increased to greater than 10(5) CFU/ml with this extension of changing time. Two long-term (15- and 9-month) infants were colonized and intermittently infected, one with Klebsiella pneumoniae and Staphylococcus aureus and the other with Pseudomonas aeruginosa. When the protocol was readjusted from 48- to 24-h circuit changes (phase II), the contamination rate decreased; for the two colonized infants (35 circuits, 123 samples) the contamination rate decreased from 19 to 6% (P less than 0.01; chi-square test), and for seven noncolonized infants (59 circuits, 217 samples) the contamination rate decreased from 5 to 0.5% P less than 0.001; (chi-square test). These data suggest that frequent changing of the circuits reduces colonization and cross-infection.
Comparison of Gram stain and Nomarski optics for screening sputum specimens before culture
Authors: Reimer L G , Kepas A
Published: January 2020

Although the Gram stain is usually used to screen sputum specimens prior to culture, wet mount observation with Nomarski optics has been suggested as a useful alternative. We compared the two methods and found that more specimens were rejected by the Gram stain technique without eliminating any that yielded important clinical information.
Conjunctivitis Caused by a Nutritionally Variant Streptococcus
Authors: Barrios Heidi , Bump Charles M.
Published: January 2020

We report on a case of conjunctivitis caused by a nutritionally variant streptococcus in a newborn infant.
Modified extraction procedure for gas-liquid chromatography applied to the identification of anaerobic bacteria
Authors: Thomann W R , Hill G B
Published: January 2020

Chloroform and ether commonly are used as solvents to extract metabolic organic acids for analysis by gas-liquid chromatography in the identification of anaerobic bacteria. Because these solvents are potentially hazardous to personnel, modified extraction procedures involving the use of a safer solvent, methyl tert-butyl ether were developed which remained both simple to perform and effective for organism identification.
Detection by gas chromatography of 3-deoxy-D-manno-2-octulosonic acid and L-glycero-D-manno-heptose in whole cells of Neisseria elongata
Authors: Guerrant G O , Moss C W
Published: January 2020

Lipopolysaccharide components 3-deoxy-D-manno-2-octulosonic acid and L-glycero-D-manno-heptose were detected in hydrolysates from whole cells of Neisseria elongata by gas-liquid chromatography. Cells from a single plate were hydrolyzed, and carbohydrate components were converted to aldononitrile and O-methyloxime acetate derivatives for subsequent analyses by gas-liquid chromatography. 3-Deoxy-D-manno-2-octulosonic acid was well separated from other cell components as the O-methyloxime acetate derivative. With both derivatives, L-glycero-D-manno-heptose was readily identified by their different retention times. The procedure requires only a relatively small number of cells, and detection is accomplished without prior isolation of the lipopolysaccharide.
Reduction of morbidity and mortality rates for neonatal group B streptococcal disease through early diagnosis and chemoprophylaxis
Authors: Lim D V , Morales W J , Walsh A F , Kazanis D
Published: January 2020

Pregnant women, part of the term service population at Orlando Regional Medical Center, were screened for group B streptococci (GBS), using Lim Group B Strep Broth (GIBCO Laboratories, Madison, Wis.) and the Phadebact Strep B Test (Pharmacia Diagnostics, Piscataway, N.J.). Of the 803 women screened, 173 were confirmed as colonized with GBS at the time of admission in labor. Eighty of these women were treated with ampicillin at least 6 h prior to delivery. The remaining 93 women received no ampicillin. None of the infants born to the treated women was colonized with GBS at surface culture sites. Forty-three of the infants born to untreated women were colonized. Rapid identification of GBS colonization in women, combined with ampicillin chemoprophylaxis, significantly reduced vertical transmission of GBS.