bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Enterobacteriaceae in frozen microdilution trays prepared by Micro-Media Systems
Authors: Barry A L , Badal R E , Effinger L J
Published: January 2020

Frozen microdilution trays, with 20 different biochemical test media for identification of Enterobactericeae, were evaluated. The test panels were those provided by Micro-Media Systems (MMS), who also provided a code book for interpretation of the test results. The interpretations of the MMS test system and of the Analytab API 20E test system were compared with those obtained from tests with conventional media. Tests with 468 Enterobacteriaceae demonstrated nearly comparable results with the two commercial systems. About 6% (API) and 7% (MMS) of the isolates could not be identified without additional tests, and another 3% (MMS) to 4% (API) of the isolates gave test patterns that were not found in the code books. One to three percent of the isolates were misidentified. It was concluded that the MMS Enteric Quad Panels provide an efficient, relatively inexpensive, and reasonably accurate method for identification of the Enterobacteriaceae.
Longitudinal survey of the distribution of various serotypes of Streptococcus mutans in infants
Authors: Masuda N , Tsutsumi N , Sobue S , Hamada S
Published: January 2020

The establishment of various serotypes of Streptococcus mutans was studied serologically in plaque samples collected from label surfaces of upper primary incisors of 22 infants (starting age, 5 to 13 months) over a period fo 30 months. Clinical examinations were also performed. No clear-cut association between the initiation of dental caries and previous detection of S. mutans was noted. However, all 12 of the infants with caries had S. mutans isolated at some time during the course of this study. The most common serotype isolated at the initial establishment of S. mutans on the tooth surfaces was serotype c, whereas types d, e, and g became established in a few cases. During the test period, changes in the distribution of serotypes of S. mutans were observed in some cases. The initiation of carious lesions could be found in a few cases even when S. mutans comprised about 1% or less of the total streptococcal count of the specimen from the tooth surfaces. Serotype d/g strains tended to develop carious lesions on smooth surfaces, although serotype c was isolated from almost all individuals who developed caries.
Practical considerations in using counterimmunoelectrophoresis to identify the principal causative agents of bacterial meningitis
Authors: Finch C A , Wilkinson H W
Published: January 2020

Many clinical laboratories are currently using counterimmunoelectrophoresis (CIE) as an aid in the rapid diagnosis of bacterial meningitis. Because cross-reactions among causative agents have been reported, the present study was undertaken to explore the problems that might occur when reference and commercial antisera are used in CIE. Broth cultures of 35 bacterial strains were tested with 76 reference and commercial antisera by CIE. Some of the antisera tested failed to react with their homologous strains. Furthermore, several cross-reactions between genera, as well as within species, were noted. These findings suggest that precautions must be taken to insure that all materials used in CIE tests are of high quality. If properly performed and interpreted, CIE may be a valuable adjunct in the identification of organisms causing bacterial meningitis, but it is, nevertheless, a presumptive test and should not be used to replace the Gram stain and culture techniques.
Semiquantitative catalase test as an aid in identification of oxidative and nonsaccharolytic gram-negative bacteria
Authors: Chester B
Published: January 2020

A simple and rapid semiquantitative slide catalase test useful for the identification of oxidative and nonsaccharolytic gram-negative bacteria, i.e., "nonfermenters," is described. Using the interpretative criterion of time of appearance of oxygen bubbles in 3% hydrogen peroxide, three categories of nonfermenters were established. The rapid catalase producers included Achromobacter xylosoxidans and Achromobacter species; Acinetobacter anitratus and Acinetobacter lwoffii; Bordetella bronchiseptica; CDC group IVE; Pseudomonas aeruginosa, P. fluorescens, P. putida, P. diminuta, and P. acidovorans; and Moraxella urethralis and M-6. The delayed catalase producers included Bordetella parapertussis, CDC group VA-1, P. alcaligenes, P. cepacia, P. mendocina, P. pickettii (VA-2), P. pseudoalcaligenes, P. putrefaciens, P. stutzeri, P. testosteroni, and P. vesicularis. The third group consisted of an additional 17 taxa of nonfermenters which were classified as moderate catalase producers.
Comparison of rates of virus isolation from leukocyte populations separated from blood by conventional and Ficoll-Paque/Macrodex methods
Authors: Howell C L , Miller M J , Martin W J
Published: January 2020

One hundred fifty-two blood specimens, largely from immunocompromised patients, were collected in heparinized Vacutainer tubes and divided into paired aliquots of equal volume. Buffy-coat preparations, containing mixed leukocyte and separate mononuclear and polymorphonuclear leukocyte populations were obtained by treatment of blood with conventional and Ficoll-Paque/Macrodex (F-P/M) methods. The development of cytopathic effect in monolayers of WI-38 fibroblasts inoculated with cell suspensions derived from the two methods was used to assess virus infectivity. Twice as many virus isolations were obtained using F-P/M. Of those viruses isolated by both conventional and F-P/M, the development of cytopathic effect was more extensive using the latter method. Moreover, a greater variety of viruses was isolated using F-P/M method, as compared to the conventional method. The F-P/M method is no more time consuming than conventional procedures, is readily adaptable for use in the diagnostic virology laboratory, requires only minimal additional cost, and is a particularly suitable and effective means of monitoring viremia.
Lipoproteins as substitutes for serum in Mycoplasma culture medium
Authors: Washburn L R , Somerson N L
Published: January 2020

Crude lipoprotein-containing fractions obtained from sera of three different animal species were tested, in combination with bovine serum in Mycoplasma pneumoniae culture medium. All sera yielded at least one lipoprotein-containing component which was considerably more effective in promoting mycoplasma growth than the unfractionated serum sample from which it was derived. The very low activity of certain whole-serum samples tested in this investigation suggests that toxic substances may be present in whole serum which are not contained in the lipoprotein preparations. The greatest activity appeared in the high-density lipoprotein-containing components of bovine and horse sera and the low-density lipoprotein-containing components of human serum. The high degree of growth-supporting activity of these crude lipoprotein-containing serum components suggests that they may be useful as serum substitutes in mycoplasma culture media.
Evaluation of vented blood culture media with sorbitol
Authors: Hall M M , Mueske C A , Ilstrup D M , Washington J A
Published: January 2020

Two consecutive studies comparing the recovery of microorganisms from transiently vented blood cultures in tryptic soy or brain heart infusion broth with added sorbitol and that from tryptic soy broth without sorbitol failed to demonstrate any significant advantage of hypertonic media. A significantly greater number of organisms was isolated in both studies from the medium without sorbitol.
Evaluation and comparison of two assays for detection of immunity to rubella infection
Authors: Brody J P , Binkley J H , Harding S A
Published: January 2020

Two commercially available rapid screening tests, Rubacell (Abbott Laboratories; passive hemagglutination) and FIAX (International Diagnostic Technology; indirect immunofluorescence) were compared with a standard hemagglutination inhibition assay for detection of immunity to rubella infection. In tests of approximately 300 sera, both rapid assays were specific and sensitive and showed a high predictive value of a positive result. Within-run reproducibility studies were excellent for both tests; however, Rubacell was superior to FIAX with respect to time-cost analysis.
Comparison of a semiautomated fluorescent immunoassay system and indirect immunofluorescence for detection of antinuclear antibodies in human serum
Authors: Casavant C H , Hart A C , Stites D P
Published: January 2020

A semiautomated fluorescent immunoassay system (FIAX) for detecting anti-nuclear antibodies (ANAs) in human serum was compared with conventional indirect immunofluorescence using microscope slides (Meloy Laboratories) coated with mouse fibroblasts. The FIAX system uses quantitative indirect immunofluorescence to measure the specific binding of ANA to a sampler coated with human epithelial cells. A total of 101 serum samples were examined for the presence of ANAs by employing both methods. At an initial 1:10 screening dilution, 23 samples were negative for ANAs by the slide method, whereas 21 samples were negative with the FIAX system. Using 2+, 3+, and 4+ subjective brightness, 68 (100%) samples were positive by the slide method, whereas 67 (98.5%) were positive with the FIAX system. ANA-positive samples were diluted twofold from 1:10 to 1:640, and positive titers were determined by both methods. Sixty (77%) of 78 positive samples titrated by FIAX came within +/-1 dilution of the titers determined by the slide method, and 75 (96%) of the samples fell within +/-2 dilutions. Results indicate good correlation between the FIAX system and indirect immunofluorescence for the detection of ANAs in human serum. The FIAX system has the advantage of speed, reproducibility, and the elimination of subjective microscopic assessment of ANA titers.
Upper limit of normal titer for detection of antibodies to Legionella pneumophila by the microagglutination test
Authors: Klein G C , Jones W L , Feeley J C
Published: January 2020

An upper limit of normal microagglutination titer for the Knoxville strain of Legionella pneumophila was determined by testing 830 sera. The upper limit of normal titer was found to be 8; however, we suggest that when applied to single serum specimens a titer of 32 be considered the lowest titer suggestive of infection (not necessarily disease).
Group G streptococcal pneumonia and sepsis in a newborn infant
Authors: Ancona R J , Thompson T R , Ferrieri P
Published: January 2020

A case of neonatal pneumonia and sepsis caused by a group G Streptococcus is described. Clinical and microbiological aspects of group G streptococci are compared with those of group B streptococci.
Growth of Nonfermentative Bacteria at 42° C
Authors: Oberhofer Thomas R.
Published: January 2020

Growth at 42°C is advocated to differentiate species of the fluorescent pseudomonas group as well as to differentiate other nonfermentative bacteria. Methodologies vary in the performance of the test, resulting in differing and often discrepant results between investigators. During this evaluation, the test was performed by inoculating 3 ml of Trypticase soy broth with a loopful of an overnight broth culture. Growth in the 42°C tube was judged as heavy or slight after 24 and 48 h incubation at 41.5 ± 0.5°C.
Pseudomonas aeruginosa
grew abundantly after overnight incubation, whereas 16 of 74 isolates of
P. putida
(22%) showed slight turbidity in the broth after 24 or 48 h which could not be regarded as an inoculum effect. Trypticase soy agar was used in conjunction with Trypticase soy broth, with the growth again judged as heavy or slight. Growth of
P. putida
on slants was still seen in some cases (6%) although the number of strains showing growth had declined. Triphenyltetrazolium chloride was added to Trypticase soy broth (0.005%) as a color indicator of growth. Strains of
P. putida,
although showing visible evidence of growth, gave no color change when compared with the 35°C control. The constancy in test results using nonfermentative bacteria is not only method dependent but also strain dependent. Although the test for growth at 42°C is important as a taxonomic tool when used under controlled conditions, other tests such as acetamide are preferred as a substitute for use in the clinical laboratory.
Testicular cultivation of Treponema pallidum (Nichols strains) facilitated by sustained-release steroid administration
Authors: Brause B D , Qualls S , Roberts R B
Published: January 2020

Treponema pallidum cultivation is facilitated by substitution of methylprednisolone acetate suspension for hydrocortisone administration during rabbit testicular infection. Methylprednisolone suspension reduces testicular mononuclear cell infiltration and should benefit future studies of virulent T. pallidum.
Serodiagnosis of respiratory synctial virus infections in infants and young children by the immunoperoxidse technique
Authors: Gerna G , Cattaneo E , Cereda P M , Grazia Revello M , Achilli G
Published: January 2020

The immunoperoxidase antibody (IPA) technique was used to develop two new tests for serodiagnosis of respiratory syncytial virus infections: a microneutralization test based on the reduction of the number of infected cells and an IPA test for determination of virus-specific immunoglobulin G (IgG). Neutralizing antibody was determined both in the presence and absence of complement. In a group of 24 infants and young childres, ages less than 1 to 36 months, with acute respiratory syncytial virus infection, serodiagnosis was made by the IPA-IgG test in 20 cases, by neutralization test with addition of complement in 19 cases, and by neutralization test without addition of complement in 17 cases. Complement fixation detected only 12 cases of infection. All four cases not serologically diagnosed were infants less than 1 month old. Neutralization test antibody titers in the presence of complement were usually 4- to 16-fold higher than titers obtained without addition of complement. Both IPA-IgG and neutralization test (in the presence of complement) appear very efficient in serologically detecting respiratory syncytial virus infections in infants older than 1 month and give rapid results (IPA-IgG takes 2 h to complete, and the neutralization test takes 24 h). However, IPA-IgG is simpler to perform.
Inhibition of Pseudomonas aeruginosa slime production by staphylococcal extracellular product
Authors: Shibl A M , Al-Sowaygh I A
Published: January 2020

Staphylococcus aureus produced an inhibitory factor that suppressed slime formation by Psuudomonas aeruginosa but had little effect on the growth of the organism. The inhibitory factor was not found in broth cultures but could be extracted from cultures grown on solid agar. The inhibitory factor moderately inhibited gram-negative bacteria in addition to inhibiting a variety of gram-positive bacteria. The inhibitory factor was found to have a low molecular weight, as judged by its diffusibility, and it could be partially purified by gel filtration on Sephadex G-50. It was observed to be heat labile; however, its activity was stable within a wide pH range. The factor was resistant to deoxyribonuclease, ribonuclease, and lipase, but sensitive to trypsin. The role of the inhibition of slime production in pathogenicity is discussed.
Automated direct antimicrobial susceptibility testing of microscopically screened urine cultures
Authors: Tilton R E , Tilton R C
Published: January 2020

Two screening methods for urine microbiology are proposed: one in which the Gram-stained smear is used to detect significant bacteriuria, and another in which Autobac antibiotic susceptibility tests are performed directly on positive urine samples. Results on 1,350 specimens indicated that an average of 18 bacteria per oil immersion field were observed in the urine of patients with significant bacteriuria, and an average of less than 1 bacterium per oil immersion field was found in the urine of patients without significant bacteriuria. Direct susceptibility testing by Autobac proved to be rapid (3 h versus 24 h) and reliable (0.5 to 1.2% discrepancies).
Comparison of the hemagglutination inhibition procedure and an enzyme-linked immunosorbent assay for detection of specific antibodies to pneumonia virus of mice in experimentally infected laboratory rats
Authors: Descôteaux J P , Payment P , Trudel M
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) and the hemagglutination inhibition (HI) test were used to evaluate the response of laboratory rats to experimental infection with pneumonia virus of mice. The ELISA procedure was more sensitive than the HI test and detected very low levels of antibodies early in the course of infection. At 5 days postinfection, ELISA detected antibody increases in five of five animals, whereas only two of five increases were detected by the HI test. At 9 days postinfection, the HI test failed to detect one titer increase measured by ELISA. Later during the course of infection, increases were detected by both tests. The ELISA procedure was, in general, more sensitive for detecting low levels of antibody than was the HI test, but was equal in sensitivity when high titers of antibody were measured.
Mycobacteria with a growth requirement for ferric ammonium citrate, identified as Mycobacterium haemophilum
Authors: Dawson D J , Jennis F
Published: January 2020

Three previously unidentified strains of pathogenic mycobacteria which had been isolated on media containing ferric ammonium citrate were found to be identical with the new species, Mycobacterium haemophilum.
Detection of endotoxin on sterile catheters used for cardiac catheterization
Authors: Kundsin R B , Walter C W
Published: January 2020

Pyrogen reactions during cardiac catheterization are an alarming complication that frightens patients and baffles many physicans. This report describes a simple, reproducible, precise technique for the measurement of endotoxin-like activity on the inner and outer surfaces of catheters intended for intravascular insertion. This technique is useful in documenting the cause of patient reactions. Quality control procedures should be instituted following the manufacture of angiographic catheters so that pyrogen-free products are availabe for patient use. Catheters processed in a hospital are easily contaminated with fever-producing lipopolysaccharides from tap water or from bacterial growth in residual moisture. Sterilization by steam or ethylene oxide does not destroy these lipopolysaccharides. Consequently, reprocessing reusable catheters must include concern for removing lipopolysaccharides as well as sterilization.
Simple and microbiologically safe portable transport unit for patients requiring protected isolation
Authors: Talbot T L , Pizzo P A
Published: January 2020

The removal of a patient from a laminar air flow room during protected isolation poses the risk of his microbial contamination and infection. Nonetheless, temporary removal from the laminar air flow room may be necessary for certain medical procedures or for psychological relief during prolonged periods of isolation or both. A means for protecting patients during temporary removal from the laminar air flow room is highly desirable. A previously described total body garment has been shown to be microbiologically safe and effective, but is expensive, cumbersome, and not very adaptable to patients of different ages and body sizes. We now present an alternative, microbiologically safe transportation system which delivers, high-efficiency particulate air-filtered air over the head and neck through a modified, lightweight, commercially available helmet and power supply and which can be comfortably and reliably used by isolated patients.
Lactose-positive Vibrio in seawater: a cause of pneumonia and septicemia in a drowning victim
Authors: Kelly M T , Avery D M
Published: January 2020

Lactose-positive Vibrio is a recently recognized marine organism that has pathogenic potential for humans. An organism was isolated from the sputum and blood of a man who was resuscitated after drowning in the sea. The isolates from both sources had the characteristics of lactose-positive Vibrio, which include positive oxidase, citrate, indole, and o-nitrophenyl-beta-D-galactopyranoside reactions and negative Voges-Proskauer, urease, and sucrose reactions. Seawater samples from 21 sites around Galveston Island were cultured for lactose-positive Vibrio over a period of 4 weeks, and 36% of the samples yielded the organism. The environmental isolates were very similar to the clinical isolates in biochemical reactions and susceptibility to antimicrobial agents. The results indicate that lactose-positive Vibrio is a common organism in the marine environment and that it should be considered in the diagnosis of infections, including pneumonia, associated with exposure to the sea.
New Salmonella serovar, Salmonella eingedi [61,62,7:f,g,t:1,(2),7]
Authors: Cahan D , Greenberg Z , Bergner-Rabinowitz S , Sechter I , Gerichter C B
Published: January 2020

A new Salmonella serovar, Salmonella eingedi, was isolated from the intestinal content of a snake, Coluber rhodorhachis, and later also from the diarrheal stools of two children.
Survival of Campylobacter fetus subsp. jejuni in biological milieus
Authors: Blaser M J , Hardesty H L , Powers B , Wang W L
Published: January 2020

To provide new information on the epidemiology and pathophysiology of human infection with Campylobacter fetus subsp. jejuni, we studied its survival in several milieus. Standard inocula of organisms were placed in hydrochloric acid, human bile and urine, bovine milk, or stream water and kept at 4, 25, or 37 degrees C; viable organisms were then counted. Stools from humans infected with Campylobacter were similarly tested. Survival in acid was pH and time dependent, with 7-log kill within 5 min in solutions at pH 2.3. Organisms multiplied in bile at 37 degrees C and survived for 2 months. Organisms survived better in feces, milk, water, and urine kept at 4 degrees C than they did in these milieus at 25 degrees C. Maximal viabilities of Campylobacter organisms kept at 4 degrees C were 3 weeks in feces, 3 weeks in milk, 4 weeks in water, and 5 weeks in urine. Study results suggest that when these milieus are contaminated with C. fetus subsp. jejuni, they may be significant environmental reservoirs.
Use of monoclonal antibodies in an enzyme immunoassay for rapid identification of group B Streptococcus types II and III
Authors: Polin R A , Kennett R
Published: January 2020

Streptococci belonging to Lancefield group B are frequently recognized as the etiological agents of sepsis and meningitis in young children. Current methods of identifying these organisms have not been universally accepted because of the time and complexity in performing the studies and a lack of reference antisera. We have developed hybrid myeloma (hybridoma) cell lines which secrete large amounts of antibody against types II and III group B streptococci. Antibodies harvested from supernatants react only with the bacterial strain that was used initially to immunize the animals. We have used the hybridoma antibodies in an enzyme immunoassay and have shown it to be a sensitive and reliable technique for typing group B streptococci. The use of hybridoma antibodies in the enzyme immunoassay may permit early detection of group B streptococcal antigen before cultures are visibly positive.
Characterization of
Brucella abortus
Soluble Antigen Employed in Immunoassay
Authors: Berman David T. , Wilson Bambi L. , Moreno Edgardo , Angus Robert D. , Jones Lois M.
Published: January 2020

A soluble antigen extract of
Brucella abortus
(BASA) has been prepared by the National Veterinary Services Laboratories and furnished to a number of workers who are examining antibody-mediated and cell-mediated immune responses of cattle infected with
B. abortus.
Three lots of BASA were examined. There were quantitative but not qualitative differences among lots by content of protein, total carbohydrate, hexose, fatty acid, and 2-keto-3-deoxyoctonic acid. The presence of smooth lipopolysaccharide was demonstrated by the presence of 2-keto-3-deoxyoctonic acid and lipid, by
Limulus
lysate gelation activity, and by formation of characteristic lipopolysaccharide precipitates in immunoelectrophoresis. A polysaccharide antigen as well as two nonsurface antigens, A2 and C, were also identified. BASA is a satisfactory antigen for use in the enzyme-linked immunosorbent assay since the smooth lipopolysaccharide component bound to polystyrene and functioned in the test. Normal murine spleen cells showed a mitogenic response to BASA similar to that produced by purified smooth lipopolysaccharide. BASA has been used in other laboratories to stimulate peripheral blood leukocytes from cattle infected with
B. abortus.
Because BASA is a mixture of antigenic components shown to have mitogenic effects in the mouse system, questions on the nature of its stimulatory effect on bovine cells are raised.
WSJM, a simple chemically defined medium for growth of Neisseria gonorrhoeae
Authors: Wong T P , Shockley R K , Johnston K H
Published: January 2020

The growth requirements of 135 clinical isolates of Neisseria gonorrhoeae and six American Type Culture Collection reference strains were examined by using a simple chemically defined medium known as Wong-Shockley-Johnston medium, WSJM. The simple liquid medium supported growth of gonococci from an inoculum of 2 X 10(6) colony-forming units ml-1 and yielded 10(10) colony-forming units ml-1 in 10 h in the absence of CO2. Scale-up experiments with the complete medium yielded 5 to 10 g, wet weight, of cells per liter. The complete medium was stable upon storage at 5 degrees C and after lyophilization.
Antibodies to staphylococcal enterotoxin in laboratory personnel
Authors: Jozefczyk Z , Robbins R N , Spitz J M , Bergdoll M S
Published: January 2020

Eighty-five percent of laboratory personnel working with staphylococcal enterotoxin had antibodies to enterotoxin in their sera, whereas only 23% of the control group had antibodies specific for enterotoxin. Two persons who carried enterotoxin B-producing staphylococci in their noses, throats, or both, had antibodies to enterotoxin B in their sera.
Cellular fatty acid composition of Campylobacter fetus
Authors: Blaser M J , Moss C W , Weaver R E
Published: January 2020

The cellular fatty acid composition of 29 human and animal isolates of Campylobacter fetus was determined with gas-liquid chromatography. All strains contained small amounts of 3-hydroxytetradecanoic acid, suggesting the presence of lipid A. Each of 13 different blood or stool isolates of C. fetus subsp. jejuni obtained from humans or fowl contained a 19-carbon cyclopropane acid which was not present in C. fetus subsp. fetus (6 strains from cattle) or C. fetus subsp. intestinalis (10 strains from humans and cattle). These findings indicate that C. fetus subsp. jejuni can be rapidly differentiated from other C. fetus by gas-liquid chromatography analysis of cellular fatty acids.
Spontaneous bacterial peritonitis due to a group IIk-2 strain
Authors: Dhawan V K , Rajashekaraiah K R , Metzger W I , Rice T W , Kallick C A
Published: January 2020

This paper describes a patient with spontaneous bacterial peritonitis caused by a group IIk-2 strain. No other organism was isolated from the peritoneal fluid cultured aerobically and anaerobically.
Extraintestinal human infection caused by Edwardsiella tarda
Authors: Clarridge J E , Musher D M , Fainstein V , Wallace R J
Published: January 2020

Edwardsiella tarda is an uncommon enteric bacterium which has been found generally in animal hosts and occasionally in human feces. Three cases of extraintestinal infection caused by E. tarda which are described herein include a typhoid-like illness, peritonitis with sepsis, and cellulitis from a wound acquired while fishing. The microbiology of E. tarda and the previous reports of infection due to this organism are reviewed.
Seroepidemiology of rotavirus infection in rural Bangladesh
Authors: Sack D A , Gilman R H , Kapikian A Z , Aziz K M
Published: January 2020

A prospective seroepidemiological study of rotavirus infection was performed in children in a village in rural Bangladesh. Ninety-three percent of the children had detectable antibodies during the study, and there were 66 significant rises in titer occurring in 57 of the 85 children. Antibody titer rises occurred in older children and younger children with equal frequency. Nine children (11%) had evidence of multiple infections during the 16-month period. Winter infections were most frequent, although one summer (monsoon) season was also associated with a large cluster. Subjects with high titers (greater than 1:8) of antibody less frequently developed a titer rise than did subjects with lower titers.
Ventricular peritoneal shunt infection caused by a member of the rhodochrous complex
Authors: Boughton W H , Atkin J F
Published: January 2020

Microorganisms of the rhodochrous complex were isolated in pure culture from a ventricular peritoneal shunt in a 5.5-month-old child.
New paper enzyme-linked immunosorbent technique compared with microimmunofluorescence for detection of human serum antibodies to Rickettsia tsutsugamushi
Authors: Crum J W , Hanchalay S , Eamsila C
Published: January 2020

A new paper enzyme-linked immunosorbent assay was developed for the screening and titration of human serum antibodies against the scrub typhus rickettsia, Rickettsia tsutsugamushi. The objetive was to provide a relatively simple method for antibody screening which required neither sophisticated laboratory equipment nor a high degree of technological skill. The technique develops an enzyme product from filter paper saturated with a 5-aminosalicylic acid substrate and enzymatically reacted with a commerically available anti-human immunoglobulin G peroxidase conjugate. The product of the enzymatic reaction can be interpreted visually. Comparison of 351 human sera tested by the immunofluorescent and paper enzyme-linked immunosorbent assays against a three-antigen pool of the Karp, Kato, and Gilliam strains of R. tsutsugamushi demonstrated an agreement of 96%. The sensitivity of the paper enzyme-linked immunosorbent assay as compared to immunofluorescence was 98.2%, and the specificity was 94.4%.
Physiological and serological characteristics of 48 Pasteurella multocida cultures from rabbits
Authors: Brogden K A
Published: January 2020

Forty-eight Pasteurella multocida cultures collected from rabbits over a 56-year period were examined to determine their physiological characteristics and to determine their serological types in the gel diffusion precipitin test. Generally, the physiological characteristics from 30 tests were typical for P. multocida. There were a few atypical variations in the fermentation of lactose and maltose and variations in trehalose, dulcitol, xylose, sorbitol, and glycerol. Seven cultures did not produce indole, and four cultures did not produce detectable amounts of hydrogaen sulfide. In obliquely transmitted light, 26 cultures formed large, slightly iridescent, mucoid colonies, 17 cultures had iridescent colonies, and 5 cultures had blue colonies. Heat-stable antigens from the 48 cultures reacted with antisera prepared from P. multocida type cultures presenting serotypes 1, 3, 4, 12, and 15. Antigens from 15 cultures reacted slightly with antisera from more than one serotype. Overall, gel precipitin reactions involving serotype 3 (25%) and serotype 12 (66.7%) were the most prevalent.
Collaborative investigation of the AutoMicrobic System Enterobacteriaceae biochemical card
Authors: Isenberg H D , Gavan T L , Smith P B , Sonnenwirth A , Taylor W , Martin W J , Rhoden D , Balows A
Published: January 2020

The Enterobacteriaceae biochemical card used in six separate laboratories to identify 170 representatives of Enterobacteriaceae. The AutoMicrobic System (Vitek Systems, Inc.) performed with an accuracy of 97.8% as compared with 98.1% by the standard method selected and 97.6% by a commerically prepared manual system approach. During this time, 5,450 clinical isolates belonging to Enterobacteriaceae were analyzed. Compared with the routine methods used in the various laboratories, the AutoMicrobic System identified 96.4% correctly
Spurious hydrogen sulfide production by Providencia and Escherichia coli species
Authors: Treleaven B E , Diallo A A , Renshaw E C
Published: January 2020

Hydrogen sulfide production was noted in two Escherichia coli strands and one Provaidenica alcalifaciens (Proteus inconstans A) strain isolated from clinical stool specimens durin the summer of 1979. An investigation into this phenomenon revealed the predence of Eubacterium lentum, an anaerobe, growing in synergism with the Enterobacteriaceae and producing H2s. The implications of this association are discssed with reference to clinical microbiology laboratory practice.
Typing of
Proteus mirabilis
by Bacteriocin Production and Sensitivity as a Possible Epidemiological Marker
Authors: Kusek John W. , Herman Lloyd G.
Published: January 2020

Two bacteriocin typing methods, based on bacteriocin production and bacteriocin sensitivity, were developed to aid in the separation of strains of
Proteus mirabilis
. One hundred sixty-two isolates of
P. mirabilis
and 10 Cradock-Watson bacteriocin producers were grown inproteose peptone no. 3 broth and induced with mitomycin C under culture conditions found optimum for bacteriocin production. Crude bacteriocin lysates were spotted on 186 indicator strains, and after incubation for 18 h at 35°C, positive zones of inhibition were recorded. A cluster analysis computer program was used to select 16 bacteriocin-producing and 16 indicator strains for inclusion in two bacteriocin typing sets. One hundred clinical isolates of
P. mirabilis
were differentiated by bacteriocin sensitivity into 41 distinct patterns, with 72% of the strains typable, whereas typing by bacteriocin production demonstrated 29 separate lysis patterns among the 80% typable strains. Combining the results of each typing method resulted in 72 individual bacteriocin production-sensitivity patterns and 91% of the isolates typed. Typing 14 epidemic strains by bacteriocin production revealed that 13 of 14 strains were identical, whereas only 2 of 14 strains were typable by bacteriocin sensitivity. Electron microscopy of partially purified bacteriocin revealed tail components of contractile bacteriophages. Standard bacteriocin lysates were destroyed by boiling for 1 h. In addition, all bacteriocin lysates tested were resistant to trypsin. The use of our bacteriocin production typing method against the presently selected 16 standard indicator strains is recommended for the investigation of any cases of suspected
P. mirabilis
cross-infections within hospitals.
Gas-liquid chromatography of bacterial fatty acids with a fused-silica capillary column
Authors: Moss C W , Dees S B , Guerrant G O
Published: January 2020

The use of flexible, fused-silica capillary column for gas-liquid chromatographic analysis of bacterial fatty acids is illustrated with Propionibacterium acnes, Propionibacterium shermanii, and a standard methyl ester mixture.
Detection of Pseudomonas aeruginosa antigenemia in granulocytopenic rabbits by radiommunoassay
Authors: Kohler R B , Wheat L J , White A
Published: January 2020

We assessed the ability of a solid-phase radioimmunoassay, modified to allow antigen detection in serum, to detect circulating antigens in granulocytopenic rabbits with Pseudomonas aeruginosa bacteremia. In vitro experiments with Pseudomonas lipopolysaccharide indicated that treatment of serum-lipopolysaccharide mixtures with heat, chloroform, or heparin improved the sensitivity for detecting lipopolysaccharide 8- to 16-fold. Chloroform treatment permitted antigen detection in serum or plasma of bacteremic rabbits in which antigen could be detected poorly or not at all in untreated specimens. However, chloroform-treated specimens occasionally caused dissolution of plastic tubes, resulting in nonspecific binding of 125I-labeled anti-Pseudomonas immunoglobulin G. Heating sera at 56 degree C for 30 min improved antigen detection both in both in lipopolysaccharide-serum mixtures and in bacteremic rabbits. Antigen was detected in the heated serum or plasma of 20% of 20 culture-positive granulocytopenic rabbits, none of 15 culture-negative granulocytopenic rabbits, and none of 38 normal rabbits. Antigen was detected in none of 15 rabbits with 2 to 300 colony-forming units of P. aeruginosa per ml of blood and in 4 of 5 rabbits with > 10(3) colony-forming units per ml. We conclude that circulating antigens are present in the blood of rabbits with high-level P. aeruginosa bacteremia and that these antigens can be detected by solid-phase radioimmunoassay. Further improvements in assay sensitivity will be required to detect antigens, if present, in animals with lower levels of P. aeruginosa bacteremia.
Prevalence of gentamicin- and amikacin-resistant bacteria in sink drains
Authors: Perryman F A , Flournoy D J
Published: January 2020

Sink drains from the Veterans Administration Medical Center, University of Oklahoma Health Sciences Center, and the Oklahoma City community were selectively cultured for gentamicin- and amikacin-resistant bacteria. Aminoglycoside-resistant organisms were found in 86% (Veterans Administration Medical Center, 88%; University of Oklahoma Health Sciences Center, 88%; and Oklahoma City community, 77%) of all 233 sink drains sampled. Of 207 sink drains harboring aminoglycoside-resistent organisms, 99% of the organisms were gentamicin resistant and 82% were amikacin resistant. These data suggest that aminoglycoside-resistent organisms are commonly present in the environment.
Cultural and biochemical characteristics of clinical isolates of unusual colistin-resistant pseudomonads
Authors: Oberhofer T R
Published: January 2020

Biochemical characteristics and antibiotic susceptibilities of 12 strains of colistin-resistant pseudomonads isolated from clinical specimens are reported. The isolates were short, oxidase-positive, nonfluorescing, gram-negative rods that failed to grow on salmonella-shigella or cetrimide agars, to decarboxylate amino acids, and to reduce nitrates. Most strains peptonized litmus milk and grew at 42 degrees C. Glucose, lactose, maltose, xylose, and fructose were slowly oxidized, whereas sucrose was not. Two homogeneous species were found and tentatively listed as Pseudomonas sp. 1 and Pseudomonas sp. 2, and these were differentiated by gelatin and starch hydrolysis, oxidation of mannitol, and alkalinization of allantoin. The two species were shown to differ from the Center for Disease Control Va group biotype CDC Va-1 in both biochemical characteristics and susceptibility to the aminoglycosides.
Isolation and identification of Haemophilus ducreyi in a clinical study
Authors: Sottnek F O , Biddle J W , Kraus S J , Weaver R E , Stewart J A
Published: January 2020

Seventeen strains of Haemophilus ducreyi were isolated from genital lesions which were negative for syphilis by dark-field examination. Media used for primary isolation at various times during the study were enriched chocolate agar, chocolate agar plus vancomycin (3 microgram/ml), rabbit blood agar plus vancomycin (3 micrograms/ml), fetal bovine serum agar, and fetal bovine serum agar plus vancomycin (3 micrograms/ml). H. ducreyi was isolated on chocolate agar plus vancomycin from 10 of 14 patients found to be positive on one or more media, on rabbit blood agar plus vancomycin from 16 of 17 patients, and on fetal bovine serum agar plus vancomycin from 9 of 11 patients. Sera from six animal species were tested to determine if any would support the growth of H. ducreyi. Horse and rabbit sera supported light growth of some strains. Fetal bovine serum supported good growth of all strains included in the study. Biochemical and physiological tests were done on the 17 isolates, a reference strain of H. ducreyi, and two reference strains of Haemophilus haemoglobinophilus. The results agreed with those reported by Kilian, except that H. ducreyi produced alpha-hemolysis in stabs on rabbit blood agar and was oxidase positive, three strains were urease positive, and CO2 improved the growth of seven strains. All 17 isolates were beta-lactamase positive. The reference strains were beta-lactamase negative.
Hemolytic activity in enterotoxigenic and non-enterotoxigenic strains of Escherichia coli
Authors: DeBoy J M , Wachsmuth I K , Davis B R
Published: January 2020

We screened 223 strains of Escherichia coli belonging to serotypes previously associated with the production of enterotoxin for hemolytic activity, using horse erythrocytes in liquid and in agar media. Thirty-eight were hemolytic. They belonged to nine different serotypes; most (65.8%) belonged to one serotype, O6: H-. Additionally, all 38 strains were specifically assayed for a filterable, heat-labile hemolytic activity previously associated with a hemolysin plasmid. A comparison of hemolytic activity and enterotoxicity showed that none of 32 strains hemolytic in both media was enterotoxigenic; 28 of the 32 expressed heat-labile hemolytic activity. Four of the six strains hemolytic in only one of the media were enterotoxigenic; none of these six expressed heat-labile hemolytic activity. Of 223 strains, 176 that were of human origin and isolated in the United States were further assayed for three traditionally plasmid-mediated characteristics: heat-labile enterotoxin, heat-stable enterotoxin, and colonization factors. The interrelationships of these characteristics, including hemolytic activity, may reflect varying degrees of plasmid compatibility.
Membrane filter contact technique for bacteriological sampling of moist surfaces
Authors: Craythorn J M , Barbour A G , Matsen J M , Britt M R , Garibaldi R A
Published: January 2020

We used a membrane filter contact technique to pick up and grow bacteria from artificially contaminated surfaces. We were able to recover individual colony-forming units (CFU) of Staphylococcus aureus from a moist agar surface more efficiently with 3- and 5- micron membrane filters than with Rodac plates, velvet pads, velveteen pads, or smaller-pore membrane filters. The effective transfer of bacteria with the 3- and 5-micron membrane filters was 0.96 +/- 0.04 (standard error of the mean) and 0.99 +/- 0.04, respectively, as compared to 0.49 +/- 0.03 for Rodac plates, 0.09 +/- 0.01 velvet pad imprints, 0.05 +/- 0.01 for velveteen pad imprints, 0.27 +/- 0.02 for velvet pad rinses, 0.005 +/- 0.001 for velveteen pad rinses, 0.39 +/- 0.02 for 0.45-micron filters, and 0.85 +/-0.05 for 1.2 micron filters. In addition, the recovery of S. aureus from contaminated bovine muscle surfaces with the 5-microns membrane filter was similar to that of quantitative dilutions of biopsy material and was significantly higher than the recovery from Rodac plates. The 5-microns membrane filters on a paddle recovered 52 +/- 5 CFU/cm2 from artificially contaminated bovine skeletal muscle, the quantitative dilutions of biopsy recovered 69 +/- 5 CFU/cm2, and the Rodac plate recovered 5 +/- 3 CFU/cm2. Sampling of moist surfaces by the membrane filter contact technique is easy to perform and highly efficient; our data suggest that it could be employed for cultures of clinical surfaces such as surgical wounds or burns.
Clostridium difficile in relation to enteric bacterial pathogens
Authors: Falsen E , Kaijser B , Nehls L , Nygren B , Svedhem A
Published: January 2020

All feces samples (n = 2,390) sent to the Bacteriological Laboratory, Göteborg, Sweden over 43 days were, in addition to the standard procedure, cultivated to detect Clostridium difficile by using a special selective medium. C. difficile was found in 81 of the 2,390 samples (3%). These 81 samples represented 56 patients. Fifty of the 56 patients had diarrhea. In 20 of the 56 patients (36%), Salmonella, Campylobacter, or Yersinia were also found. Of the 2,390 samples 252 (11%) from 132 patients revealed positive isolations of Salmonella, Shigella, Campylobacter, or Yersinia in comparison to 3% for C. difficile alone. This result suggests that C. difficile can easily be isolated with proper techniques. Concomitant isolations of more than one bacterial pathogen in cases of gastroenteritis were often found for C. difficile. The theory presented here is that any change of the normal bacterial fecal flora due to such causes as antimicrobial treatment or enteric infections like Salmonella increases the possibilities of isolating C. difficile. The causative significance of C. difficile might in most cases be doubtful. The majority of cases with diarrhea and C. difficile were self-healing and not severe. Only 2 cases of 56 had severe diarrhea with extended engagement of the colonic mucous membrane, but with no signs of pseudomembranes.
Quantitative microtiter cytotoxicity assay for Shigella toxin
Authors: Gentry M K , Dalrymple J M
Published: January 2020

The cytotoxic activity of Shigella dysenteriae 1 was assayed by exposing HeLa cells in microtiter cultures to dilutions of toxin. Exposure to toxin caused either failure of cells in suspension to attach or detachment of cells from established monolayers. Estimates of toxin potency were made by staining residual cells with crystal violet and visually inspecting the stained plates. Quantitation of the cytotoxic effect was made possible by eluting and spectrophotometrically measuring the stain. The dilution of toxin causing 50% cell detachment, the endpoint chosen for the assay, was estimated from plots of dye absorbance versus toxin dilution. The 50% cell detachment dilution of toxin varied as a function of cell concentration, incubation of toxin with cells in suspension or as established monolayers, and the cell line used for assay. The HeLa cell line was the most sensitive of the cell lines examined. The method was easily utilized to monitor toxin purification and to measure antitoxin neutralization of toxin activity.
Comparison of direct immunofluorescent staining of clinical specimens for respiratory virus antigens with conventional isolation techniques
Authors: Minnich L , Ray C G
Published: January 2020

Staining of clinical respiratory specimens obtained by nasopharyngeal and throat swabs with direct fluorescein isothiocyanate-conjugated antisera to para-influenza virus types 1, 2, and 3, influenza A virus, respiratory syncytial virus, adenovirus, mumps virus, and measles virus was compared with isolation procedures in routine tissue culture systems. Direct staining of clinical specimens with the commercially available conjugated offered a rapid means of diagnosing respiratory infections on a routine clinical basis when used in conjunction with isolation in tissue culture systems. Of 292 patients who were culture positive for these viruses, 259 were diagnosed by detection of the viral antigen in clinical specimens by direct immunofluorescence. No specimens that subsequently yielded a different respiratory virus by culture were positive by the direct immunofluorescence method. Use of selected antisera based on clinical history of the patient reduced the cost of rapid viral diagnosis.