bluuebunny/crossref_metadata_2025 huggingface dataset:
False-susceptible results from the MS-2 system used for testing resistant Pseudomonas aeruginosa against two third-generation cephalosporins, moxalactam and cefotaxime
Authors: Stone L L , Jungkind D L
Published: January 2020

The MS-2 system (Abbott Laboratories) was used for cefotaxime and moxalactam susceptibility testing of 111 Pseudomonas aeruginosa isolates collected from our burn treatment center. The frequency of very major errors was 52% for moxalactam and 32% for cefotaxime for all isolates requiring a minimal inhibitory concentration of greater than or equal to 64 micrograms/ml. For isolates requiring a minimal inhibitory concentration of 64 micrograms/ml, the very major errors were 78% for moxalactam and 57% for cefotaxime. Testing of an additional 44 isolates collected from another hospital confirmed that these results were not unique to nosocomial strains from within the burn center. The ratio of errors did not change when MS-2 results were compared with disk diffusion results. Colony count testing done on cuvettes which produced false-susceptible results indicated that little numerical change occurred during the 5- to 6-h test cycle, whereas microscopy of cuvette contents revealed metabolically active filamentous bacilli. The high frequency of false-susceptible results indicated that the MS-2 should not be used for testing clinical P. aeruginosa isolates for resistance to the two third-generation cephalosporins currently available for the MS-2. A comparison of the disk diffusion results indicated that neither moxalactam nor cefotaxime could be reliably used for predictive, class-concept testing of P. aeruginosa.
Comparison of epidemiological markers used in the investigation of an outbreak of methicillin-resistant Staphylococcus aureus infections
Authors: Archer G L , Mayhall C G
Published: January 2020

An outbreak of nosocomial infections was caused by a single strain of methicillin-resistant (MR) Staphylococcus aureus. This strain was followed as it was transmitted from the index case to 17 patients, 3 hospital personnel, and 12 items in the hospital environment. The MR S. aureus strain was traced by using four specific epidemiological markers: antibiogram, phage type, production of aminoglycoside-inactivating enzymes, and plasmid pattern. These markers were assessed for their reliability in differentiating the epidemic S. aureus strain from resident nonepidemic strains and for the ease and rapidity with which they determined differences. The epidemic strain was resistant to beta-lactam antibiotics, gentamicin, erythromycin, clindamycin, and rifampin. Resistance to rifampin was the only unique marker in the antibiogram which distinguished the epidemic strain from the indigenous strains, and it was the easiest marker to use for screening isolates from culture surveys. Phage typing was poorly reproducible and did not yield results rapidly enough to be useful for ongoing epidemiology. The epidemic strain produced a unique aminoglycoside-inactivating enzyme (3'-phosphotransferase) which distinguished it from indigenous gentamicin-resistant staphylococci, but this marker was not easily identified, nor was identification helpful during the course of the investigation. Plasmid pattern analysis was rapidly performed (in less than 24 h), allowed many isolates to be examined at a time, was stable and reproducible, and yielded a unique fingerprint which distinguished the epidemic strain from all indigenous isolates. Plasmid pattern analysis is a promising epidemiological tool for MR S. aureus outbreaks in which epidemic strains lack unique antibiotic resistance markers.
Isolation of Campylobacter jejuni from an appendix
Authors: Chan F T , Stringel G , Mackenzie A M
Published: January 2020

Campylobacter jejuni Skirrow biotype 1, Lior serotype 8 was isolated from the appendix of an 11-year-old boy who had a 6-h history of acute abdominal pain. Histological diagnosis on the appendix section was early acute appendicitis. Dilute carbol fuchsin stain and indirect fluorescent antibody test performed on the appendix section also revealed the presence of Campylobacter sp. The patient developed a significant bactericidal antibody titer of 1,024, providing substantial clinical evidence of the pathogenicity of the isolate. This case indicated that not only may abdominal pain caused by Campylobacter enteritis mimic appendicitis, but the organism may actually be recovered from the infected appendix.
Enzyme-linked immunosorbent assay for serodiagnosis of Mycoplasma pneumoniae infections
Authors: Busolo F , Tonin E , Meloni G A
Published: January 2020

Enzyme-linked immunosorbent assay (ELISA) was used for detection of antibodies against Mycoplasma pneumoniae. The results of ELISA were compared with those of other serological methods, such as complement fixation, metabolic inhibition, mycoplasmacidal test, and radioimmunoprecipitation. ELISA and mycoplasmacidal test showed greater sensitivity than did complement fixation and metabolic inhibition. Radioimmunoprecipitation showed serum titers 2- to 16-fold higher. Specificity of ELISA was determined by testing other human mycoplasmas. A simplified method based on the determination of ELISA antibody end-point titer by a single serum dilution is proposed.
Septicemia due to a maltose-positive, glucose-negative strain of group C Neisseria meningitidis
Authors: Watanakunakorn C , Thomson R B
Published: January 2020

A glucose-negative, maltose-positive strain of group C Neisseria meningitidis was isolated from the blood of a 63-year-old man. Interestingly, maltose degradation was detected by radiometric methods but not by growth methods.
Comparison of a monoclonal antibody with a polyclonal serum in an enzyme-linked immunosorbent assay for detecting adenovirus
Authors: Anderson L J , Godfrey E , McIntosh K , Hierholzer J C
Published: January 2020

To develop and evaluate an enzyme-linked immunosorbent assay (ELISA) for detecting adenovirus antigens in which a group-specific monoclonal antibody to the adenovirus hexon is used, we studied two different ELISA test systems. The test system which was the most sensitive and specific was then compared in parallel tests with a similarly constructed ELISA in which a mouse polyclonal serum was used. Both the ELISA with the monoclonal antibody and that with the polyclonal serum detected purified hexon and 15 different adenovirus types with similar sensitivities. The two assays also showed no reaction with 23 heterologous viruses. Both tests detected adenovirus in stool and respiratory tract specimens tested for adenovirus by standard tissue culture techniques with similar sensitivities and specificities, but neither was sufficiently sensitive for routine testing of these types of clinical specimens. However, the ELISA with the monoclonal antibody proved to be a good test for the noncultivatable adenoviruses, detecting 12 of 12 stool samples that were positive by electron microscopy. The monoclonal antibody proved to be as sensitive and specific as the polyclonal serum and has the advantage that it can be produced in unlimited quantities and needs to be characterized only once.
Monoclonal antibodies against group- and type-specific lipopolysaccharide antigens of Vibrio cholerae O:1
Authors: Gustafsson B , Holme T
Published: January 2020

Hybrid cell lines producing monoclonal antibodies against the O-antigenic determinants of Vibrio cholerae O:1 have been established. The specificity of the antibodies was ascertained by enzyme-linked immunosorbent assay inhibition experiments by using lipopolysaccharides from V. cholerae O:1 strains and type strains of groups O:2 and O:21. The anti-A antibody was of the immunoglobulin M (IgM) class, whereas the anti-B and -C antibodies were IgG3. The antibodies had a good agglutinating capacity when tested against V. cholerae O:1 strains in the slide agglutination test.
Detection of Rickettsia rickettsii antibodies in human sera by crossed immunoelectrophoresis
Authors: Anacker R L , Philip R N , Wilfert C M , Kleeman K T , Turner L , MacCormack J N , Hechemy K E
Published: January 2020

To identify Rickettsia rickettsii antigens of immunological importance, we examined sera from patients with serologically confirmed cases of Rocky Mountain spotted fever by crossed immunoelectrophoresis for antibodies to antigens extracted from the R strain of R. rickettsii with the detergent Triton X-100. Sixteen antigens were identified in the detergent extract by crossed immunoelectrophoresis with a hyperimmune rabbit serum raised against whole rickettsiae. When the rabbit antiserum was placed in the reference gel and patient sera were placed in the intermediate gel, antibodies to one or more antigens were detected in 61 of 71 North Carolina sera, all of 7 Oklahoma sera, and 9 of 10 Montana sera obtained from 1 day to 40 years after onset of Rocky Mountain spotted fever. Antibodies to antigens 1 and 16 were found as early as 1 day after onset of illness, and antibody to 16 was found in 20 of 29 sera obtained within the first 7 days of illness. Antibodies to antigens 2 and 3 generally did not appear until the third week of illness but were found in six of seven serum samples collected 4 to 40 years after onset of Rocky Mountain spotted fever. Antibodies to R. rickettsii antigens 1, 7, 8, and 16 were found in sera from patients with illnesses caused by other etiological agents. Four of the Oklahoma and Montana sera from Rocky Mountain spotted fever patients, but none of the North Carolina sera, had antibodies to antigen 12. Sera containing antibodies against antigens 3 and 14 prevented death of mice challenged with two 50% lethal doses of R. rickettsii.
Assay of antibody to group A streptococcal carbohydrate by enzyme-linked immunosorbent assay
Authors: Barrett D J , Triggiani M , Ayoub E M
Published: January 2020

An indirect enzyme-linked immunosorbent assay system for determination of antibody levels to the group A streptococcal cell wall carbohydrate antigen is described. Optimal conditions for antigen preparation, purification, and conjugation to poly-L-lysine for adequate adsorption to the solid phase are presented. Antibody titers of unknown sera were determined by comparison to known reference standard pool sera. A highly significant correlation (p less than 0.0001) was found between enzyme-linked immunosorbent assay antibody titers and antigen-binding capacity in a previously described radioimmunoassay. Utilizing an isotype-specific anti-immunoglobulin reagent and immunoabsorbent-purified antibody to group A streptococcal cell wall carbohydrate antigen, we were able to detect nanogram quantities of antibody by the enzyme-linked immunosorbent assay technique. This system will provide for more generalized use of group A streptococcal cell wall carbohydrate antigen antibody determinations for the study of immune responses after streptococcal infections and their complications.
Improved serological diagnosis of rubella
Authors: Cremer N E , Hagens S J , Fukuchi R
Published: January 2020

The use of an enzyme immunoassay-immunoglobulin G antibody test instead of the hemagglutination inhibition test as a primary test for the serological diagnosis of current infection, with complement fixation as an alternate test for use when enzyme immunoassay results are high and stationary, improved the serological diagnosis of rubella.
Group JK corynebacterium peritonitis in a patient undergoing continuous ambulatory peritoneal dialysis
Authors: Pierard D , Lauwers S , Mouton M C , Sennesael J , Verbeelen D
Published: January 2020

We describe a case of peritonitis with isolation of a group JK corynebacterium from the peritoneal effluent in a patient undergoing continuous ambulatory peritoneal dialysis and treated with corticosteroids. Therapy with intraperitoneal vancomycin resulted in a rapid eradication of the organism. However, only 1 month after discontinuation of the 26-day therapy, a second episode of peritonitis with JK corynebacterium occurred. After vancomycin was restarted, the organism disappeared again from the peritoneal fluid, but the patient died a few days later from heart failure apparently unrelated to the infection. Some authors have mentioned the isolation of diphtheroids (without further identification) from peritoneal effluent of continuous ambulatory peritoneal dialysis patients, but to our knowledge, this is the first report of peritonitis associated with JK corynebacterium, an opportunistic organism that must be differentiated from other corynebacteria.
Evaluation of transport media for Campylobacter jejuni in human fecal specimens
Authors: Wang W L , Reller L B , Smallwood B , Luechtefeld N W , Blaser M J
Published: January 2020

It is not always possible to culture feces immediately, and appropriate methods for transport of human specimens, unlike those from animals, have not been fully evaluated. Therefore, we took serial subcultures in two phases from six transport media inoculated with human diarrheal stools known to be positive for Campylobacter jejuni. In phase 1, Cary-Blair medium and buffered glycerol saline did not preserve C. jejuni as well as did alkaline peptone-water (APW), modified Cary-Blair medium, thioglycolate broth (Thio), and Campy-Thio. The four best media (APW, Cary-Blair medium, Thio, and Campy-Thio) preserved 20 fecal samples with C. jejuni better at 4 degrees C (90% survival for 5 to 8 days) than at 25 degrees C (90% survival for 1.7 to 2 days). In phase 2, APW and Thio, along with four modifications of the best media in phase 1, were tested with 23 positive strains. The ranges of survival times with modified media at 25 degrees C were 1.3 to 2.2 days (90%) and 4.7 to 6.8 days (50%). APW with reducing agents preserved C. jejuni better than did APW alone, Thio plus ox bile, or Campy-Thio plus ox bile (P less than 0.05). Thio at pH 8.5 was better at preserving C. jejuni than was APW or Thio plus ox bile (P less than 0.05). If human fecal specimens cannot be refrigerated during transport or storage, we recommend the use of Thio at pH 8.5 or APW with reducing agents for preservation of C. jejuni at 25 degrees C.
Rapid microbiochemical identification of Corynebacterium diphtheriae and other medically important corynebacteria
Authors: Thompson J S , Gates-Davis D R , Yong D C
Published: January 2020

A rapid biochemical method based on the fermentation of carbohydrates, the hydrolysis of urea, and the reduction of nitrate was used to identify Corynebacterium diphtheriae, C. ulcerans, C. pseudodiphtheriticum, C. haemolyticum, C. pseudotuberculosis, C. pyogenes, C. ovis, the Centers for Disease Control JK group, and Rhodococcus (Corynebacterium) equi. With this procedure identification was confirmed for 133 stock cultures and clinical isolates of corynebacteria. Most were identified within 1 h and all were identified within 4 h after inoculation into the test substrates.
Comparison of stained smears and culturing for identification of Treponema hyodysenteriae
Authors: Olson L D , Fales W H
Published: January 2020

A comparative study was made of stained fecal smears and cultured fecal swabs for identification of the large spirochetes Treponema hyodysenteriae and Treponema innocens. Feces were obtained by swabbing rectums, colons, and stools of nonexposed swine and swine experimentally exposed to swine dysentery. In this study there was a significant (P less than 0.001) correlation between the observation of one or more large spirochetes on stained slides and obtaining either a strong or a weak beta-hemolytic reaction in culture. A significant (P less than 0.001) correlation was also found between the observation of one or more large spirochetes on stained smears or obtaining either a strong or a weak beta-hemolytic reaction in culture and the occurrence of either nonhemorrhagic or hemorrhagic diarrhea in the swine. In the diarrheic swine at the time of swabbing, 157 of 393 samples (40%) were negative for both the presence of large spirochetes on stained smears and the production of either a strong or a weak beta-hemolytic reaction; in nondiarrheic swine, 42 of 278 samples (15.1%) were positive in stained smears and 32 of 268 samples (11.9%) were positive by culturing. In swine infected with swine dysentery, 17 of 1,011 samples produced weak beta-hemolytic reactions, and in swine infected with nonpathogenic large spirochetes of T. innocens, three of 34 samples produced strong beta-hemolytic reactions. It was concluded from this study that neither staining rectal smears nor culturing rectal swabs is sufficient, either together or alone, for the diagnosis of swine dysentery; however, these laboratory methods could be highly supportive of a diagnosis of swine dysentery in swine with clinical signs and lesions of the disease.
Isolation of Yersinia spp. from bovine feces
Authors: Fukushima H , Saito K , Tsubokura M , Otsuki K , Kawaoka Y
Published: January 2020

Yersinia spp. were sought in 618 fecal samples from cows. Four strains of Yersinia enterocolitica, serotype O:12,26 (one), O:13,7 (two), and O:18 (one); seven strains of Yersinia kristensenii, serotype O:11,24 (five) and O:12,26 (two); and one strain of Yersinia pseudotuberculosis serotype IIB, were isolated. This is the first time that Y. pseudotuberculosis has been isolated from cows in Japan, and the isolation of serotype IIB of this organism from cows seems to be the first in the world.
Correlation of an expanded direct fluorescent-antibody system with an established passive hemagglutination system for serogrouping strains of Campylobacter jejuni and Campylobacter coli
Authors: Hébert G A , Penner J L , Hennessy J N , McKinney R M
Published: January 2020

Rabbits were inoculated with whole, formalinized cells from eight passive hemagglutination reference strains of Campylobacter. Fluorescein isothiocyanate-labeled immunoglobulin G from these antisera defined seven new direct fluorescent-antibody serogroups of C. jejuni and one new serogroup of C. coli. This expanded the Campylobacter direct fluorescent antibody system to include 17 serogroups of C. jejuni, 3 serogroups of C. coli, and 2 serogroups of C. fetus. We then compared the passive hemagglutination method (57 serotypes) and the direct fluorescent-antibody method (20 serogroups) for typing strains of C. jejuni and C. coli. The data obtained by testing 101 strains by both methods revealed that the two test systems were measuring completely different sets of antigen complexes. The two serogrouping methods were complementary, and their combined use discriminated among strains more effectively than did either method individually.
Lack of efficacy of alkali treatment for isolation of Yersinia enterocolitica from feces
Authors: Ratnam S , Looi C L , Patel T R
Published: January 2020

The efficacy of KOH treatment to enhance isolation of Yersinia enterocolitica from stools containing fecal flora which is not adequately suppressed by selective media was tested by direct plating and enrichment techniques. Although a distinct difference in the level of alkali tolerance was observed between Y. enterocolitica and the fecal organisms included in the study, the selective suppression of the fecal flora from stools could not be consistently achieved on this basis. By direct plating, the isolation rates ranged from 4 to 32% for untreated control samples and 11 to 40% for KOH-treated samples, varying with the medium used for culture. The maximum overall recovery rate was 34% by overnight enrichment of fecal samples in Selenite F, tetrathionate, Trypticase soy, and gram-negative broths or by 2-day enrichment in modified Rappaport broth. Alkali treatment of fecal samples did not significantly enhance the isolation rates by these methods. One hundred percent recovery was achieved by prolonged cold enrichment, and alkali treatment made no difference in the recovery rate by this method. Cefsulodinirgasan-novobiocin agar generally yielded higher isolation rates of Y. enterocolitica than did cellobiose-arginine-lysine agar and MacConkey agar, both by direct plating of fecal samples and through subcultures of enrichments, regardless of KOH treatment.
Epidemiological studies of Streptococcus pneumoniae in infants: development of antibody to phosphocholine
Authors: Gray B M , Dillon H C , Briles D E
Published: January 2020

The pneumococci possess, in addition to type-specific capsular polysaccharides, a number of antigens common to the species. Antibodies to phosphocholine (PC), a major determinant of the C-carbohydrate, have been shown to protect mice from experimental pneumococcal infection, but little is known of the role of anti-PC antibodies in humans or the extent to which anti-PC levels are affected by carriage or infection. We examined 115 sera from 30 infants, who were followed prospectively from birth through 4 years of age, for the presence of immunoglobulin M antibody to PC, using a solid-phase radioimmunoassay method. Infants were found to develop antibody to PC in response to pneumococcal carriage and infection, and nearly all infants developed some antibody. Antibody levels increased with age. By using a regression model including both age and nasopharyngeal carriage of pneumococci, anti-PC levels were found to be highest after exposure to two or three different types of pneumococci; levels were highest soon after acquisition of pneumococci and declined thereafter.
Immunoassay diagnosis of adenovirus infections in children
Authors: Meurman O , Ruuskanen O , Sarkkinen H
Published: January 2020

Direct detection of viral antigen in nasopharyngeal secretions and stool specimens by radioimmunoassay and the determination of serum antibody responses by complement fixation and immunoglobulin class-specific enzyme immunoassay against the hexon antigen were compared for diagnostic efficacy in 52 children with acute adenovirus infections. The highest diagnosis rate (85% of the cases) was obtained by antigen detection in nasopharyngeal secretions. Adenovirus antigen was also detected in stools of 72% of the 18 patients tested. The immunoglobulin G (IgG) antibody enzyme immunoassay detected 77% of the cases, being more sensitive than the complement fixation test with a 67% detection rate. The IgM antibody response was variable with no clear correlation with the age of the patient or severity of the clinical symptoms. IgM antibody response was detected in 48% of the patients and had the normal transient course, with a persistence of the IgM antibodies of approximately 2 months. Determination of IgA antibodies gave a diagnostic increase in titer in 37% of the cases and was found less suitable for serological diagnosis. Because of the clinical importance of rapid laboratory diagnosis, the direct detection of viral antigen in nasopharyngeal secretions or stool or both should be used as the primary diagnostic test in adenovirus infections.
Monoclonal antibodies against hepatitis A virus
Authors: MacGregor A , Kornitschuk M , Hurrell J G , Lehmann N I , Coulepis A G , Locarnini S A , Gust I D
Published: January 2020

Three monoclonal antibodies (K2-4F2, K3-2F2, and K3-4C8) of the immunoglobulin G2a class were raised against hepatitis A virus. The specificity of these antibodies was confirmed by immune electron microscopy, solid-phase radioimmunoassay, and in vitro neutralization in cell culture. Binding studies suggested that they all recognize closely related antigenic determinants. These monoclonal antibodies should prove to be of great value as diagnostic and research reagents.
Probable Campylobacter fetus subsp. fetus gastroenteritis
Authors: Harvey S M , Greenwood J R
Published: January 2020

Three strains of Campylobacter fetus subsp. fetus isolated from cases of gastroenteritis are reported. DNA-DNA hybridizations in addition to biochemical tests were used to confirm the identification of the isolates as C. fetus since all strains grew at 42 degrees C. These isolates, like other C. fetus strains, are susceptible to cephalothin and thus would not have been detected in laboratories with Campylobacter isolation media containing this component.
Comparison of two automated instrument systems for rapid susceptibility testing of gram-negative bacilli
Authors: Johnson J E , Jorgensen J H , Crawford S A , Redding J S , Pruneda R C
Published: January 2020

The Vitek AutoMicrobic System with GSC-plus cards and the Abbott MS-2 system were tested in parallel and the results were compared directly with those of a reference microdilution minimal inhibitory concentration (MIC) procedure on a group of 262 clinical isolates of the family Enterobacteriaceae and of Pseudomonas aeruginosa. Results of both systems were compared with the reference MIC for category agreement, and in addition, the Vitek MICs were compared with those obtained by the reference procedure. The Vitek system provided an essential category correlation of 89.4% for enteric bacteria and 97.0% for P. aeruginosa. Vitek MICs agreed within 1 twofold dilutional increment for 86.3% of the enteric bacteria tested and for 96.2% of the P. aeruginosa isolates. The Abbott MS-2 essential categoric agreement was 92.0% for enteric bacteria and 92.4% for P. aeruginosa. If only aminoglycosides or carbenicillin were considered for P. aeruginosa isolates, the essential category agreement was 92.5% for the Vitek and 93.3% for the MS-2. The majority of MS-2 category errors (13 of 19) with P. aeruginosa involved gentamicin results on isolates whose reference MICs were 8 micrograms/ml and whose MS-2 results were susceptible (MIC less than or equal to 4 micrograms/ml). Retesting of the P. aeruginosa isolates in calcium-supplemented MS-2 broth increased the essential agreement for the aminoglycosides to 97.5%.
Detection of type-specific antigens in the lungs of Haemophilus pleuropneumoniae-infected pigs by coagglutination test
Authors: Mittal K R , Higgins R , Larivière S
Published: January 2020

Specific diagnosis of Haemophilus pleuropneumoniae infection by the conventional culture and identification method usually requires 3 to 4 days. Since H. pleuropneumoniae may be disseminated from infected individuals during this period, this amount of time required for diagnosis may be too slow to aid in epidemic control. To obtain an earlier diagnosis, a coagglutination test was successfully used to detect serotype-specific antigens in lung extracts of infected pigs. A total of 19 lung tissues from experimentally infected pigs, 240 lung tissues from naturally infected pigs that died of pleuropneumonia, and 571 lung specimens from an apparently healthy pig population were examined for culture isolation as well as for antigen detection. The results showed that detection of antigens in lung tissues by the coagglutination test is an extremely rapid, simple, quite specific, and highly sensitive procedure for the diagnosis of H. pleuropneumoniae infection. Further, detection of antigens in lung tissues was found to be a much simpler and much more rapid method than culture isolation. The coagglutination test seems to be especially useful for detecting H. pleuropneumoniae in pigs exposed to chronic infection as well as those in which multiple serotypes are involved.
Comparison of the effects of acid and base hydrolyses on hydroxy and cyclopropane fatty acids in bacteria
Authors: Lambert M A , Moss C W
Published: January 2020

The cellular fatty acid compositions of Legionella oakridgensis, Brucella suis, Pseudomonas aeruginosa, and Francisella tularensis were compared after base hydrolysis (saponification), acid hydrolysis, and acid methanolysis procedures were used to release the fatty acids. The branched-chain, unsaturated, saturated, and ester-linked hydroxy acids were released as effectively with saponification at 100 degrees C for 30 min as with acid hydrolysis or acid methanolysis at 85 degrees C for 16 h. Although the amide-linked hydroxy acids were released more effectively by acid hydrolysis or acid methanolysis, these methods degraded the cyclopropane fatty acids, producing a number of new peaks or artifacts in the chromatograms. Cyclopropane fatty acids were not degraded by saponification, and at least 50% of the hydroxy acids were released when the cells were saponified with 15% NaOH in 50% aqueous methanol. Thus, the results show that saponification for 30 min at 100 degrees C with 15% NaOH, followed by methylation is an excellent method for routine fatty acid analysis of bacteria and for screening cultures whose identity and fatty acid composition are unknown.
Selective diagnostic medium for pathogenic Listeria spp
Authors: Skalka B , Smola J
Published: January 2020

Pathogenic Listeria serovars produced hemolysis on agars containing 5% rabbit erythrocytes and 10 micrograms of acriflavin, 40 micrograms of nalidixic acid, and 7.5 activity units of equi factor per ml. Apathogenic Listeria innocua was nonhemolytic on this medium.
Comparison of the API Staph-Ident and DMS Staph-Trac systems with conventional methods used for the identification of coagulase-negative staphylococci
Authors: Giger O , Charilaou C C , Cundy K R
Published: January 2020

Two commercial kit systems, the API Staph-Ident system (Analytab Products, Inc., Plainview, N.Y.) and the DMS Staph-Trac system (DMS Laboratories, Inc., Flemington, N.J.), were compared with conventional methods for the identification of nine species of coagulase-negative staphylococci. The API Staph-Ident system, a biochemical and chromogenic substrate micromethod, correctly identified 95 of 120 (79.2%) clinical isolates of coagulase-negative staphylococci after 5 h of incubation. The DMS Staph-Trac system, a miniaturized biochemical test system which requires a 24-h incubation period, correctly identified 106 (88.3%) of the same isolates. Both commercial systems were similar in cost and amount of technologist time required to inoculate and read each system. The clinical value of routine species identification of coagulase-negative staphylococci has not yet been established. The decision by clinical laboratories of whether to adopt this practice will be greatly facilitated by the availability of commercial kit systems which are both rapid and accurate.
Lyme disease: a selective medium for isolation of the suspected etiological agent, a spirochete
Authors: Johnson S E , Klein G C , Schmid G P , Bowen G S , Feeley J C , Schulze T
Published: January 2020

A simple procedure with a new selective culture medium for the isolation of the suspected etiological agent of Lyme disease from ticks is described. Live ticks (Ixodes dammini) were ground with a mortar and pestle, and the suspensions were inoculated into a selective and nonselective medium. The selective medium, which contained kanamycin and 5-fluorouracil, yielded positive spirochete cultures from 100% of the pooled ticks and from 79% of the single tick specimens. The isolation rate for the nonselective medium was 0% from the tick pools and 58% from the single tick specimens.
Analysis of bacterial isolates from cerebrospinal fluid
Authors: Olson D A , Hoeprich P D
Published: January 2020

We set out to determine the frequency of occurrence of contamination of cerebrospinal fluid with bacteria, seeking also to identify aids to differentiating contaminants from etiologically significant isolates. From 2,091 specimens, 182 bacterial isolates were obtained from 129 patients. Meningitis was the source of 81 isolates (32 patients); contamination yielded 101 isolates (97 patients). The cell counts and protein and glucose concentrations in the cerebrospinal fluid were significantly more often abnormal in specimens from patients with meningitis. Haemophilus influenzae and enteric gram-negative bacilli were usually cause for meningitis, whereas Staphylococcus epidermidis was the most common contaminant. In view of the reported high rate of procedural error in carrying out lumbar puncture, a program aimed at teaching proper technique is recommended to decrease the frequency of false-positive cultures of cerebrospinal fluid.
Production of Vibrio cholerae O1 and non-O1 typing sera in rabbits immunized with polysaccharide-protein carrier conjugates
Authors: Adams L B , Siebeling R J
Published: January 2020

Two systems are currently used to serologically type Vibrio cholerae O1 and non-O1 isolates. Antiserovar-serotype serum in the Smith system is produced in rabbits immunized with live whole-cell vaccines, and that in the Sakazaki system is produced in rabbits immunized with heat-killed vaccines. In neither system is the serovar-serotype-specific antigen clearly defined. During the course of a serological survey, ca. 10% of more than 2,500 V. cholerae isolates examined agglutinated in the optimal dilutions of two, three, or four different anti-serovar sera prepared by the methods of Sakazaki. An occasional isolate agglutinated in both anti-O1 and non-O1 sera. Lipopolysaccharide was extracted from eight of these possible multiple serovars, coated onto rabbit erythrocytes, and retested in these same antisera by passive hemagglutination. With one exception the lipopolysaccharide-rabbit erythrocytes were now agglutinated in a single antiserum. Antipolysaccharide sera were produced in rabbits immunized with the polysaccharide moiety extracted from eight non-O1 and two O1 vaccine strains conjugated to bovine gamma globulin protein carrier. The antipolysaccharide sera showed passive hemagglutination titers versus lipopolysaccharide-rabbit erythrocytes comparable to those achieved in antisera from rabbits immunized with heat-killed whole-cell vaccines. In the slide agglutination test antipolysaccharide sera serologically discriminated between two O1 isolates that were previously agglutinated in both anti-O1 and anti-non-O1 whole-cell sera. It is recommended that serological types or varieties of V. cholerae non-O1 be based upon serologically recognizable differences in lipopolysaccharide-associated antigens as are antigens A, B, and C in the O1 group.
Escherichia coli K5 antigen in relation to various infections and in healthy individuals
Authors: Kaijser B , Jodal U
Published: January 2020

A phage specific for Escherichia coli K5 antigen was used to determine the frequency of K5 in strains of E. coli isolated from cases of sepsis, meningitis, and urinary tract infection (pyelonephritis, cystitis, and asymptomatic bacteriuria), as well as from fecal samples of healthy subjects. Although entirely absent from meningitic strains, K5 was found to be one of the most common E. coli capsular antigens, especially in strains causing sepsis. K5 was less common in the fecal strains of healthy subjects than in strains causing various urinary tract infections, between which there was no significant difference in its frequency. Thus, even if K5 is a less important antigen than K1 in the etiology of acute pyelonephritis or acute meningitis, as the fifth most commonly occurring K antigen in E. coli strains causing urinary tract infection it should be included as a component in any K antigen-based vaccine against acute pyelonephritis.
Comparative laboratory evaluation of three antigen detection methods for diagnosis of Haemophilus influenzae type b disease
Authors: Marcon M J , Hamoudi A C , Cannon H J
Published: January 2020

Cerebrospinal fluid, urine, serum, and other body fluid specimens from pediatric patients with systemic disease were tested with Bactigen latex agglutination (555 specimens), Phadebact coagglutination (319 specimens), and counterimmunoelectrophoresis (335 specimens) for the presence of Haemophilus influenzae type b antigen. All three methods showed good sensitivity for detecting antigen in the cerebrospinal fluid of patients with culture-positive meningitis (greater than or equal to 86% sensitivity). However, coagglutination and counterimmunoelectrophoresis were much less sensitive (less than or equal to 40%) than latex agglutination (96%) for detecting antigen in other body fluid specimens in culture-positive, nonmeningeal H. influenzae disease. Bactigen latex agglutination was also more sensitive than the other procedures for detecting antigen in specimens from patients with culture-negative, presumed H. influenzae disease. Comparative testing of fluids spiked with known quantities of purified H. influenzae b polyribosephosphate capsular polysaccharide revealed an apparent 100-fold greater sensitivity with Bactigen as compared with the other two methods. Although all three methods showed good specificity (greater than 98%), both agglutination methods gave a few false-positive results. In a clinical setting where both meningeal and nonmeningeal H. influenzae b disease are encountered frequently, Bactigen latex agglutination appears to be superior to coagglutination and counterimmunoelectrophoresis for detecting antigen in body fluids.
Clinical laboratory and epidemiological investigations of a Streptococcus pyogenes cluster epidemic in a newborn nursery
Authors: Isenberg H D , Tucci V , Lipsitz P , FAcklam R R
Published: January 2020

Streptococcus pyogenes, nontypable with available M antisera, T type 12, and reactive in the serum opacity test, produced various lesions in 10 newborn infants during a 2-month period. All infants except one were discharged from the nursery before overt disease manifestations. Colonization studies of newborn infants showed a streptococcal carrier rate of 19% (27 of 140). Only 1 of 154 staff members yielded the same streptococcus from the throat, but it could not be implicated as the source for the outbreak. Cohorting of infants and chlorhexidine gluconate hand washing by staff members helped in terminating this cluster epidemic.
In vitro susceptibilities of sucrose-negative Candida tropicalis, Candida lusitaniae, and Candida norvegensis to amphotericin B, 5-fluorocytosine, miconazole, and ketoconazole
Authors: Ahearn D G , McGlohn M S
Published: January 2020

The MICs and minimal lethal concentrations of four antimycotics, amphotericin B, 5-fluorocytosine, miconazole nitrate, and ketoconazole, were determined for 25 yeast isolates representing species uncommonly implicated in candidiasis. A microdilution procedure was employed with complex and synthetic media. The isolates, in general, were susceptible to the same antimicrobial agents shown to be effective against Candida albicans, but differences between some of the species in relative susceptibilities to the antifungal agents were noted. Isolates of atypical sucrose-negative Candida tropicalis were similar in their susceptibility patterns to typical isolates of the species. Relative resistance to amphotericin B, miconazole nitrate, and ketoconazole was noted for two Candida lusitaniae isolates, but all strains were susceptible to 5-fluorocytosine. Candida norvegensis isolates were more resistant to miconazole and ketoconazole than C. albicans clinical isolates. The microtiter system was satisfactory for determining minimal inhibitory concentrations, but the system is not recommended for detecting finite differences in drug susceptibilities or for detecting drug synergism.
Enzyme-linked immunosorbent assay for detection of specific antibodies to Ureaplasma urealyticum serotypes
Authors: Wiley C A , Quinn P A
Published: January 2020

Optimal conditions of a micro-enzyme-linked immunosorbent assay system for the detection of immunoglobulin G antibodies to Ureaplasma urealyticum were established with rabbit antisera. Initially, the antisera, raised against eight U. urealyticum serotypes grown on medium containing horse serum, displayed nonspecific reactions with our enzyme-linked immunosorbent assay antigens. Substitution of fetal bovine serum in the medium eliminated this nonspecificity. The assay was then serotype-specific for the original eight U. urealyticum serotypes. The prominent homologous reaction was easily differentiated from the heterologous reactions. A one-way cross-reaction was observed with serotype 2 antiserum and serotype 5 antigen. The results were reproducible and could be obtained in 4 h with only 10 microliters of serum for eight serotypes. Optimal antigen concentrations for the U. urealyticum serotypes ranged from 0.40 to 1.60 micrograms/ml. Our results indicated that enzyme-linked immunosorbent assay has the potential for the detection of antibodies to specific serotypes of U. urealyticum.
Rapid detection of group B streptococcal antigen by monoclonal antibody sandwich enzyme assay
Authors: Morrow D L , Kline J B , Douglas S D , Polin R A
Published: January 2020

Group B Streptococcus (GBS) is the most common cause of neonatal sepsis and meningitis. Infants at greatest risk to develop invasive disease are delivered to women colonized with GBS in their birth canals and lacking immunity to the colonizing serotype. We have investigated the sensitivity and specificity of a recently developed monoclonal antibody sandwich enzyme immunoassay for detection of GBS antigen. The sandwich enzyme immunoassay detected types II and III GBS at a concentration of 5 X 10(4) CFU/ml and types Ia and Ib GBS at 5 X 10(5) CFU/ml. No cross-reactions were noted when each of the GBS serotypes was reacted with antibodies of differing serotypes specificities. Type III GBS native antigen was detected at a concentration of 1 ng/ml. The sandwich enzyme assay is more sensitive than other methods currently in use for rapid detection of GBS and is serotype specific. This assay system should prove useful for the detection of GBS colonization during labor and for identification of neonates with invasive disease.
Evaluation of the automicrobic system for susceptibility testing of Pseudomonas aeruginosa to gentamicin, tobramycin, and amikacin
Authors: Woolfrey B F , Lally R T , Ederer M N , Quall C O
Published: January 2020

The AutoMicrobic system (AMS; Vitek Systems, Inc., Hazelwood, Mo.) was studied for its ability to produce accurate and precise MIC interpretations for Pseudomonas aeruginosa susceptibility to gentamicin, tobramycin, and amikacin. MICs were determined in parallel on 200 selected P. aeruginosa isolates by using the AMS discrete-integer MIC program AMS p12.ROB for interpretation of the AMS Gram-Negative General Susceptibility Urinary Card, and a reference small-integer broth microdilution test. Parallel AMS and broth microdilution MICs were also replicated for three selected strains of P. aeruginosa for which MICs were representative of the dilution test ranges. For the 200 P. aeruginosa isolates, mean AMS MICs were significantly larger than the reference test mean MICs, coefficients of variation were approximately double those of the reference test, and correlation coefficients were unacceptably low for each antimicrobial agent. MIC replication studies for the three selected P. aeruginosa strains showed comparable AMS and reference mean MICs in the lower portions of the dilution ranges, significantly higher AMS mean MICs in the upper portions, and mean coefficients of variation of 63 and 9.6%, respectively, for replicated AMS and reference MICs. These results indicate that the AMS, in its present stage of development, does not produce acceptable MIC measurements for P. aeruginosa susceptibility to gentamicin, tobramycin, and amikacin.
Disk diffusion susceptibility testing of ticarcillin plus clavulanic acid
Authors: Fuchs P C , Jones R N , Barry A L , Thornsberry C
Published: January 2020

Disk diffusion susceptibility testing of ticarcillin plus the beta-lactamase inhibitor clavulanic acid was performed on 489 clinical isolates, and the results were compared with reference broth microdilution susceptibilities. Four different disks containing 75 micrograms of ticarcillin plus 2.5, 5, 10, and 15 micrograms of clavulanic acid were evaluated. Based on test performance and clavulanic acid stability, the 75-10-micrograms disk is recommended. Interpretive criteria for ticarcillin as published by the National Committee for Clinical Laboratory Standards appear to be satisfactory for the combination drug, but because the number of ticarcillin-clavulanic acid-resistant isolates was small, this proposal must be considered only tentative.
Rotavirus infection of young children in two districts of Kenya from 1982 to 1983 as analyzed by electrophoresis of genomic RNA
Authors: Chiba Y , Miyazaki C , Makino Y , Mutanda L N , Kibue A , Lichenga E O , Tukei P M
Published: January 2020

Employing techniques of polyacrylamide gel electrophoresis of viral RNA segments, we studied rotavirus strains and their relative contributions to rotavirus gastroenteritis epidemics in two major districts of Kenya. From early 1982 to the middle of 1983, 18 representative electropherotypes, including 6 short strains, were detected in 30 rotavirus specimens obtained from Nairobi, whereas 16, including 3 short strains, were detected in 70 virus specimens from coastal areas. With the exception of one strain, there were no identical electropherotypes between the two groups of rotaviruses obtained from these different districts. A change in predominant electropherotypes was observed in Mombasa in early 1983, and subsequently, newly occurring strains were detected in a small town along the coast when an apparent increase in gastroenteritis was observed in the district.
Glycosidase activities of Bacillus anthracis
Authors: Sadler D F , Ezzell J W , Keller K F , Doyle R J
Published: January 2020

Bacillus anthracis could be distinguished from the taxonomically related species B. cereus, B. mycoides, and B. thuringiensis by a comparison of glycosidase activities. All the bacilli tested possessed alpha-glucosidase activity, as evidenced by the hydrolysis of p-nitrophenyl-alpha-D-glucoside. In B. anthracis, the glucosidase activity could be enhanced by the addition of agents which damage cellular surface structures. Treatment of B. anthracis strains with toluene. Triton X-100, or mutanolysin or cellular disruption by sonication resulted in higher rates of alpha-glucoside hydrolysis than were accomplished by cells suspended in buffer. It is suggested that intact B. anthracis cells have a limited permeability to the glucosidase substrate. In contrast to the results obtained for B. anthracis, Triton X-100 markedly diminished the enzymatic hydrolysis of p-nitrophenyl-alpha-D-glucoside by strains of B. cereus, B. mycoides, and B. thuringiensis. Triton X-100 also enhanced the alpha-maltosidase activity of B. anthracis but not that of the other bacilli. B. mycoides possessed an apparently inducible N-acetylglucosaminidase although the enzyme was absent in B. anthracis. The glucosaminidase was inducible in the presence of p-nitrophenyl-N-acetylglucosamine in the absence of conventional nitrogen sources. Chloramphenicol prevented the induction of the glucosaminidase in B. mycoides. In several B. cereus and all B. thuringiensis strains, the glucosaminidase was constitutive. The results suggest a means for the rapid laboratory differentiation of B. anthracis from other closely related bacilli. Assays for alpha-glucosidase and alpha-maltosidase, in the presence and absence of Triton X-100, can be used to distinguish B. anthracis from B. cereus, B. mycoides, and B. thuringiensis. Similarly, the hydrolysis of p-nitrophenyl-beta-N-acetylglucosamine induced by B. mycoides but not by B. anthracis provides an additional means for differentiating these similar bacilli.
Astrovirus and Breda virus infections of dome cell epithelium of bovine ileum
Authors: Woode G N , Pohlenz J F , Gourley N E , Fagerland J A
Published: January 2020

A bovine enteric virus antigenically related to the United Kingdom isolate of bovine astrovirus was isolated from diarrheic feces, also containing rotavirus, of a calf in Florida. The astrovirus infected cell cultures and the epithelial cells of domes in the ileum, and there was cross-immunofluorescence with antiserum to the United Kingdom astrovirus. Calves infected with astrovirus alone did not develop clinical disease, but when astrovirus was mixed with rotavirus or Breda virus 2, the calves developed severe diarrhea and more extensive astrovirus infection of the dome epithelium. The dome epithelial cells showed degeneration associated with astrovirus infection, and a few cells showed degeneration with Breda virus 2 infection. Virions with a 30-nm diameter were seen in astrovirus-infected dome cells, and Breda virus 2 virions were also observed either in separate cells or, on occasion, with both viruses in one cell.