bluuebunny/crossref_metadata_2025 huggingface dataset:
Differentiation of Campylobacter and Campylobacter-like organisms by cellular fatty acid composition
Authors: Lambert M A , Patton C M , Barrett T J , Moss C W
Published: January 2020

The cellular fatty acid compositions of 368 strains of Campylobacter species or Campylobacter-like organisms were determined by gas-liquid chromatography. Most of the strains (339) were placed in one of three groups based on differences in fatty acid profiles. Group A contained Campylobacter jejuni (97%) and most C. coli (83%) strains and was characterized by the presence of a 19-carbon cyclopropane fatty acid (19:0 cyc) and 3-hydroxytetradecanoic acid (3-OH-14:0). Group B included all C. laridis and some C. coli (17%) strains; its profile was similar to that of group A, except that 19:0 cyc was absent. Group C contained C. fetus subsp. fetus and C. fetus subsp. veneralis and was characterized by the presence of 3-OH-14:0 and 3-hydroxyhexadecanoic acid (3-OH-16:0) and the absence of 19:0 cyc. Twenty-nine isolates were placed in four additional groups. Group D included the type strain of "C. cinaedi" and 14 other isolates, which were differentiated by the presence of dodecanoic acid (12:0), 3-hydroxydodecanoic acid (3-OH-12:0), and 3-OH-16:0 and the absence of hexadecenoic acid (16:1) and 3-OH-14:0. Group E contained the type strain of "C. fennelliae" and two additional isolates, which were differentiated by the presence of a 16-carbon aldehyde and a 16-carbon dimethylacetyl and the absence of 16:1. Group F included the type strain and one reference strain of C. cryaerophila and six human isolates whose phenotypic characteristics were similar to those of this species; this group was distinguished by the presence of two isomers of 16:1, tetradecenoic acid (14:1), and 3-OH-14:0. Group G included three stains of C. pyloridis and was characterized by the presence of 19:0 cyc, 3-OH-16:0, and 3-hydroxyoctadecanoic acid (3-OH-18:0) and by the absence of 16:1 and 3-OH-14:0.
Peroxidase-antiperoxidase assay for rapid detection of respiratory syncytial virus in nasal epithelial specimens from infants and children
Authors: Jalowayski A A , England B L , Temm C J , Nunemacher T J , Bastian J F , MacPherson G A , Dankner W M , Straube R C , Connor J D
Published: January 2020

A peroxidase-antiperoxidase (PAP) assay for the rapid detection of respiratory syncytial virus was compared with the indirect immunofluorescence method and with viral culture. Nasal epithelial specimens from 147 infants and children with acute respiratory infections were obtained and evaluated for the presence of respiratory syncytial virus antigens. Sensitivity, specificity, and accuracy by PAP were 91.7, 84.8, and 87.1%, respectively, and 87.0, 88.5, and 88.0%, respectively, by immunofluorescence compared with viral culture. The PAP assay was found to be as accurate as the indirect immunofluorescence method and more convenient to perform, since the color reaction and cell morphology were more easily observable by light microscopy. A new specimen collection method is reported; gentle scraping of the superficial nasal mucosa by the Rhino-probe method provided sufficient numbers of epithelial cells to perform multiple assays.
Nonvalue of sputum culture in the management of lower respiratory tract infections
Authors: Lentino J R , Lucks D A
Published: January 2020

Establishment of the microbiological etiology of bacterial pneumonia by sputum culture is confounded by both lack of recovery of fastidious pathogens and contamination of specimens with oropharyngeal flora. We reviewed the clinical records from 249 patients over a 3-month period for evidence of pneumonia. Gram staining and cultures were performed on 381 specimens isolated from this population of patients. Recovery of respiratory tract pathogens was accomplished with 354 specimens from 226 patients; 27 specimens yielded normal flora in culture but were smear positive. An additional 256 specimens submitted to our microbiology laboratory did not meet smear criteria for purulence nor did they yield respiratory tract pathogens in culture. A total of 637 specimens submitted to the microbiology laboratory were evaluated for sputum purulence by the criteria of Bartlett. Of the total 354 specimens which were positive in culture for a pathogen, 182 (52%) were submitted from 150 patients with no objective evidence of pneumonia. The majority of specimens obtained from patients without pneumonia were nonpurulent. However, 71 of 182 culture-positive specimens obtained from 50 patients without pneumonia were purulent. Approximately half of these patients (31 of 50) had other pulmonary or upper respiratory tract pathology which could account for the sputum purulence. Among the 172 culture-positive specimens from 76 patients with pneumonia, only 100 (58%) were acceptable by smear criteria. An additional 23 patients provided expectorated purulent sputum from which no respiratory tract pathogen could be isolated. Of these 23, 7 had pneumonia. We conclude that sputum culture and Gram staining are neither specific nor sensitive as diagnostic tools. Objective criteria for purulence of Gram-stained specimens must be applied before their inoculation into culture media. Specimens should be sought only from patients with objective evidence of pneumonia.
Evaluation of the syphilis Bio-EnzaBead assay for detection of treponemal antibody
Authors: Burdash N M , Hinds K K , Finnerty J A , Manos J P
Published: January 2020

An enzyme-linked immunosorbent assay for Treponema pallidum antibody (Syphilis Bio-EnzaBead Kit; Organon Teknika Corp., formerly Litton Bionetics, Kensington, Md.) was compared with the standard fluorescent treponemal antibody absorption test for syphilis (indirect fluorescent-antibody confirmatory test; Zeus Scientific Inc., Raritan, N.J.). Six hundred specimens tested in the rapid plasma Reagin card test (Hynson, Westcott and Dunning, Inc., Baltimore, Md.) and microhemagglutination assay for antibodies to T. pallidum (Ames Division, Miles Laboratories, Inc., Elkhart, Ind.) were used for comparison testing. One hundred and sixty-two specimens were from either persons with syphilis or persons whose history was unknown but who showed reactive serology, whereas 438 were from persons without syphilis. The reactivity of each serum by the Bio-EnzaBead test was determined visually and from optical density readings. Excellent reproducibility of visual readings was obtained; all results were within +/- 1 gradation of the expected readings in all 60 coded sera tested. Overall agreement between the Bio-EnzaBead and fluorescent treponemal antibody absorption test results was 96.3% when read visually and greater than or equal to 95.7% when using optical density readings. Our data indicate that Bio-EnzaBead results read at 405 nm and determined by using the mean antigen optical density reading of the nonreactive control plus 0.025 as the cutoff value provide an overall sensitivity and specificity of 93.0 and 98.6%, respectively, along with the best agreement with the fluorescent treponemal antibody absorption assay. Ease of performance and objectivity also contribute toward the acceptability of this assay as an alternative confirmatory test for syphilis.
Detection of antibody to group B adult diarrhea rotaviruses in humans
Authors: Nakata S , Estes M K , Graham D Y , Wang S S , Gary G W , Melnick J L
Published: January 2020

Group B rotaviruses have been responsible for annual epidemics of severe diarrhea affecting both adults and children in China. We developed a specific and sensitive enzyme-linked immunosorbent blocking assay to detect antibody to group B rotaviruses that will be useful to assess the role of group B rotavirus infections as a cause of human gastroenteritis. We tested 219 human sera and 18 immunoglobulin pools collected from eight countries for antibodies to both group A and group B rotaviruses. Overall, a low proportion (10 of 237 or 4.2%) of sera contained antibody to group B rotaviruses. Antibody to group B rotavirus was detected in only 1 of 155 serum samples from healthy or hospitalized individuals in the United States, including patients with the chronic inflammatory bowel diseases Crohn's disease and ulcerative colitis. No antibody was detected in 15 serum samples from Australia and from an outbreak of gastroenteritis on a cruise ship or in nine immunoglobulin pools from Japan and the United Kingdom. Antibody to group B rotaviruses was detected in 8 convalescent-(but not acute-)phase serum samples from Chinese patients with group B gastroenteritis, in five immunoglobulin pools from China, in 1 of 6 serum samples from Chinese students in the United States, and in 1 each of 10 serum samples from Kenya, 20 from Thailand, and 15 from Canada. In contrast, most of these samples (226 of 237 or 95.4%) had antibody to group A rotaviruses. These results indicate that human infection with group B rotavirus has not been widespread in areas outside China. Seroconversion observed between the acute-and convalescent-phase serum samples from China also suggests that infections with this virus are primary infections. Continued surveillance for this new group of rotaviruses should determine whether the many susceptible people become infected of whether other factors influence the severe pathogenicity of human infections with these viruses in China.
Screening and diagnostic performance of enzyme immunoassay for antibody to lymphadenopathy-associated virus
Authors: Handsfield H H , Wandell M , Goldstein L , Shriver K
Published: January 2020

In a multicenter cooperative study, an enzyme immunoassay (EIA) using purified antigen of lymphadenopathy-associated virus was compared with radioimmune precipitation (RIP) for detection of antibody to human immunodeficiency virus (HIV) in 634 patients with acquired immunodeficiency syndrome or related conditions, 687 apparently healthy persons at risk for HIV infection, 93 controls with cancer or autoimmune diseases, and 10,038 blood or plasma donors. Excluding the donors, the EIA was reactive in 875 (61.9%) of 1,414 subjects; compared with RIP, the sensitivity and specificity of EIA both were 99.8%. There was one false-positive EIA among 148 intravenous drug abusers and two false-negative EIAs among 472 apparently healthy homosexual men; no other discordant results between EIA and RIP occurred in these subjects. The EIA was repeatably reactive in 20 donors (0.2%), among whom 13 (65%) were positive by RIP; none of 529 randomly selected EIA-negative donors was RIP positive. In addition to its utility as a screening test in low-risk populations, the EIA for antibody to lymphadenopathy-associated virus is useful as a diagnostic test in persons with clinical evidence of or at risk for HIV infection.
Clinical and biochemical significance of toxin production by Aeromonas hydrophila
Authors: Kindschuh M , Pickering L K , Cleary T G , Ruiz-Palacios G
Published: January 2020

Production of cytotoxin and enterotoxin by Aeromonas strains obtained from stools of 50 children in Mexico and Texas and from blood of 9 children with sepsis was determined. Results were correlated with clinical features of infected children as well as with biochemical traits of Aeromonas strains. Cytotoxin was produced by 40 of 42 Aeromonas strains (95%) isolated from stools of children with diarrhea, by all 8 isolates from stools of well children, and by all 9 isolates from children with sepsis. There was no difference in the quantities (amount of cytotoxin per milligram of protein required to kill 50% of the cells) of cytotoxin produced and in clinical manifestations among the groups. None of the isolates produced a toxin that could be neutralized by antiserum raised against Shiga toxin produced by Shigella dysenteriae 1 60R. Heat-labile-like enterotoxin (LT) was produced by 26 of 42 stool isolates (62%), while only 1 of the 42 isolates (2%) produced enterotoxinlike activity in suckling mice; 65% of the cytotoxin-producing strains also produced an LT-like material. All strains from blood produced LT-like material, and 2 of 6 (33%) produced activity in suckling mice. All strains produced hemolysin; 37 of 57 (65%) were Voges-Proskauer positive; 27 of 57 (47%) were lysine decarboxylase positive by API 20E strips, none were positive for lysine decarboxylose production by lysin-iron agar slants at 24 h, but 17 of 54 (31%) were positive at 48 h. There was no correlation between biochemical reactions and enterotoxin or cytotoxin production. There appears to be no correlation between toxin production by Aeromonas spp. and gastroenteritis.
Retrospective study of Gen-Probe rapid diagnostic system for detection of legionellae in frozen clinical respiratory tract samples
Authors: Edelstein P H , Bryan R N , Enns R K , Kohne D E , Kacian D L
Published: January 2020

The Gen-Probe Rapid Diagnostic System for legionellae, which uses 125I-labeled cDNA directed against the rRNAs of legionellae, was evaluated for its ability to detect members of the genus by using clinical specimens which had been frozen at -70 degrees C for 2 to 8 years. Culture and direct immunofluorescence (DFA) results obtained at the time of specimen collection were used to categorize samples. The specimens tested were 112 samples culture positive for legionellae and 230 samples negative on culture and DFA tests. They were tested in a blinded and randomized fashion. Results were expressed in terms of the ratio of counts per minute of the sample to the counts per minute of the provided negative control. A ratio of greater than or equal to 4.0 was picked for optimal specificity. Of the 112 previously positive specimens, 63 (57%) were positive by the probe assay, and of the 230 previously negative samples, 228 (99.1%) were negative. The 51 discrepant specimens were reexamined by culture and DFA testing if adequate amounts remained; this was possible for 34 specimens. On repeat culture, 22 of 33 previously culture-positive samples yielded legionellae and 11 were negative. Ten of the positive repeat cultures yielded two or fewer colonies per plate. One probe-positive but previously culture-negative sample was overgrown by contaminants on repeat culture. Reanalysis of data after exclusion of the 17 unavailable, 11 repeat culture-negative, and 1 unevaluable specimen gave a probe sensitivity of 74% and specificity of 100%. The Gen-Probe test is therefore specific and is of useful sensitivity.
Hemolytic activity and invasiveness in strains of Proteus penneri
Authors: Rozalski A , Kotełko K
Published: January 2020

Twenty strains of Proteus penneri obtained from the Centers for Disease Control, Atlanta, Ga., were tested for their ability to hemolyze sheep and human erythrocytes, a property that is thought to be connected with the invasiveness and virulence of Proteus species. In the logarithmic phase of growth, P. penneri cultures are hemolytic for such erythrocytes. This ability is comparable to the hemolysis exhibited by nearly 100% of P. vulgaris and P. mirabilis strains, which is due to the production of a cell-bound hemolytic factor; is demonstrated only in broth cultures; and seems to facilitate the penetration of P. penneri and other Proteus species into the cells without cytotoxic effects. In contrast, a filterable alpha-hemolysin, which is produced transiently by a very few strains of P. mirabilis, was present in 4 of 20 P. penneri strains. This property, which is expressed at a high level over a long period, suggests a chromosomal origin. The penetration of an alpha-hemolytic P. penneri strain into Vero cells was accompanied by a drastic cytotoxic effect.
Transmission of human immunodeficiency virus from parents to only one dizygotic twin
Authors: Park C L , Streicher H , Rothberg R
Published: January 2020

The acquired immunodeficiency syndrome-related complex was identified in a mother and one of her nonidentical twins. Generalized lymphadenopathy was first noted in the infant at age 17 months, and that of the mother was incidentally discovered 6 months later. The father, who had had homosexual contacts before the conception of the twins, appeared to be in good health. No one in the family had constitutional symptoms or showed signs of opportunistic infection. Both parents and the patient had hypergammaglobulinemia, low T-helper-to-suppressor-cell ratio, and positive serum antibody to human immunodeficiency virus. Attempts to isolate the virus from all family members were unsuccessful. The twin brother was in good health with a normal immunologic profile and negative antibody to human immunodeficiency virus.
Detection of group D salmonellae in blood culture broth and of soluble antigen by tube agglutination using an O-9 monoclonal antibody latex conjugate
Authors: Lim P L , Fok Y P
Published: January 2020

Latex particles sensitized with a Salmonella O-9 monoclonal antibody were used to detect group D salmonellae in blood culture broths. The system was found to be 100% accurate when used on 104 clinical specimens that included 13 S. typhi isolates. Enteric fever could thus be diagnosed as early as 1 day after the initiation of culture in some (18%) cases. The latex particles were also used in an experimental situation to detect soluble S. typhi lipopolysaccharide by a tube agglutination method. This was found to be more than four times as sensitive as the conventional slide agglutination method because at least 50 ng of antigen per ml in either buffer or urine was detected, albeit with less efficiency when serum was used.
Isolation of Clostridium difficile and detection of cytotoxin in the feces of diarrheic foals in the absence of antimicrobial treatment
Authors: Jones R L , Adney W S , Shideler R K
Published: January 2020

Clostridium difficile was isolated from the feces of 27 of 43 diarrheic foals (63%), and cytotoxin was detected in feces from 28 diarrheic foals (65%). The foals had not received any antimicrobial treatment before the onset of diarrhea. C. difficile was not isolated from feces of 18 normal foals without diarrhea and 62 adult horses (P less than 0.005). This finding of C. difficile and its toxins in association with diarrhea in foals adds another possible cause to the list of infectious agents which may cause diarrhea in foals.
Cell culture compared with broth for detection of Trichomonas vaginalis
Authors: Garber G E , Sibau L , Ma R , Proctor E M , Shaw C E , Bowie W R
Published: January 2020

Trichomonas vaginalis can be grown in cell culture. We studied the growth kinetics of T. vaginalis in McCoy cell culture compared with that in a conventional broth medium (Diamond TYI-S-33 medium supplemented with 10% heat-inactivated bovine serum [TYI]). In the presence of McCoy cells and two parts cell culture medium to one part TYI, a peak concentration of 2 X 10(6) to 6 X 10(6) T. vaginalis per ml was consistently achieved with inocula as low as three T. vaginalis cells per ml. Without cells, this medium did not support growth of T. vaginalis. T. vaginalis in TYI in 1-ml vials with or without McCoy cells demonstrated poor growth. In tubes containing 10 ml of TYI, inocula grew to 2 X 10(6) to 6 X 10(6) T. vaginalis per ml, but at least 3 X 10(3) T. vaginalis per tube was required to initiate growth. Thus, in vitro, cell culture was more sensitive than TYI broth in detecting low numbers of T. vaginalis. In a subsequent clinical comparison of broth and cell culture for isolation of T. vaginalis from 188 vaginal specimens and 21 urethral specimens from men, the results were in agreement for 206 specimens (98.6%). There were no situations in which culture was negative and a saline preparation showed motile trichomonads. For women, using a positive culture as the indicator of true positivity, the sensitivity of detection of T. vaginalis was 83% with the Pappenheim stain and 77% with saline preparations. These studies show that cell culture can be used for isolation of T. vaginalis from clinical specimens; it gave results comparable to those of broth culture for the group of mainly symptomatic women. Further studies should be performed to determine its utility in clinical populations such as asymptomatic women and men with and without symptoms, in which T. vaginalis is more likely to be present in low numbers.
Occult bacteremia with nontypeable Haemophilus influenzae
Authors: Rubin L G , Staiman K , Kamani N
Published: January 2020

A 2-year-old boy had occult bacteremia with nontypeable Haemophilus influenzae 6 weeks after receiving H. influenzae type b polysaccharide vaccine. Evaluation of his host defense was normal. As determined by outer membrane protein electrophoresis and Southern hybridization analysis, this strain was not related to type b strains. Its virulence in rats was similar to that of another nontypeable strain and less than that of a type b strain.
Prosthetic valve endocarditis caused by Corynebacterium diphtheriae in a patient with pemphigus vulgaris
Authors: Namnyak S S , Bhat R P , Al-Jama A , Fathalla S E
Published: January 2020

The clinical and bacteriological findings in a case of prosthetic aortic valve endocarditis caused by Corynebacterium diphtheriae are presented. The patient died despite adequate medical therapy. This appears to be the first report of endocarditis caused by this species in a prosthetic aortic valve.
Comparison of biochemical, morphologic, and chemical characteristics of Centers for Disease Control fermentative coryneform groups 1, 2, and A-4
Authors: Na'Was T E , Hollis D G , Moss C W , Weaver R E
Published: January 2020

A total of 24 strains of fermentative coryneform like bacteria isolated from clinical specimens form two distinct groups which have been designated Centers for Disease Control (CDC) fermentative coryneform groups 1 (13 strains) and 2 (11 strains). The phenotypic characteristics of group 1 were similar to those of a previously described CDC group designated A-4, with the major differentiating characteristic being the inability to hydrolyze esculin. Major differences in cellular fatty acid composition between CDC groups 1 and A-4 were also observed. The branched-chain fatty acids 14-methylhexadecanoate and 12-methyltetradecanoate, which account for more than 80% of the total acids of group A-4, were not detected in cells of group 1 strains. Groups 1 and 2, which have similar cellular fatty acid compositions, can be differentiated on the basis of fermentation of xylose, mannitol, lactose, sucrose, and melibiose by group 1 but not by group 2. The sources of isolation of the strains of both groups varied. Only group 1 strains were associated with eye infections.
Effect of dialysate fluids on phagocytosis and killing by normal neutrophils
Authors: Harvey D M , Sheppard K J , Morgan A G , Fletcher J
Published: January 2020

Inadequate host defenses may partly explain the problem of recurrent peritonitis in patients on continuous ambulatory peritoneal dialysis. It has been suggested that these defenses may be adversely affected by the fluids used for dialysis, and so we examined the effects of unused, effluent, and infected peritoneal dialysis fluids on phagocytosis and killing by normal neutrophils. We used a clinical isolate of Staphylococcus epidermidis as the test organism, as this organism is the most commonly cultured in continuous ambulatory peritoneal dialysis peritonitis; we also used a fungal species, Candida guilliermondii. There was no phagocytosis of either organism in unused dialysate because of lack of opsonins and low pH. Phagocytosis in effluent dialysate did not occur because of inadequate opsonin levels and was variable in infected effluents, depending on quantities of immunoglobulins present. Intracellular killing of both test organisms was normal in unused dialysate in the presence of 5% normal serum, but was reduced in effluent and infected dialysates because of factors inhibiting killing by neutrophils. These factors adversely affected the killing of S. epidermidis more than that of C. guilliermondii. These results may explain why peritonitis recurs, particularly peritonitis due to S. epidermidis, because organisms could be sequestered within the neutrophils and thus be protected from antibiotic action. Reinfection of the peritoneal cavity would then take place following neutrophil breakdown, causing a clinical relapse.
Evaluation of a direct fluorescein-conjugated monoclonal antibody for detection of cytomegalovirus in centrifugation culture
Authors: Gleaves C A , Lee C F , Kirsch L , Meyers J D
Published: January 2020

A fluorescein-conjugated murine monoclonal antibody (MAb) reactive with cytomegalovirus (CMV) was evaluated for the detection of CMV in centrifugation culture. Of 188 specimens, 90 were positive for CMV in centrifugation culture. The fluorescein-conjugated MAb detected CMV in 86 of 90 (95%) specimens at 16 h postinoculation, and 88 of 90 (98%) were positive at 36 h. The fluorescein-conjugated MAb can be used in a direct immunofluorescence assay that can be completed in 15 min following cover slip fixation. Use of this antibody in centrifugation culture provides a convenient and rapid assay for the identification of CMV.
Effect of inoculum size on results of macrotube broth dilution susceptibility tests with Branhamella catarrhalis
Authors: Doern G V , Tubert T
Published: January 2020

The effect of inoculum size on the results of macrotube broth dilution MICs was assessed with 15 strains of Branhamella catarrhalis versus 22 antimicrobial agents. The study isolates included five beta-lactamase-negative strains, five strains that produced beta-lactamase and for which ampicillin MICs were high, and five beta-lactamase-producing strains for which ampicillin MICs were low. An inoculum effect was observed only with strains in the last group when tested versus the following antimicrobial agents: penicillin G, ampicillin, cephalothin, cefamandole, cefuroxime, and cefaclor.
Comparison of Du Pont Isolator and Roche Septi-Chek for detection of fungemia
Authors: Guerra-Romero L , Edson R S , Cockerill F R , Horstmeier C D , Roberts G D
Published: January 2020

The rapid detection of fungemia in hospitalized patients is imperative, particularly for those who are immunocompromised. Our laboratory compared the Roche Septi-Chek with the Du Pont Isolator for the recovery of fungi from blood. Of 23,586 matched pairs of blood cultures, 199 were positive. The Isolator detected 178 (89.4%) and the Septi-Chek detected 119 (59.7%) of all positive isolates. The mean recovery time for the Isolator and Septi-Chek was 2.2 and 4.9 days, respectively. The Isolator detected fungemia earlier than the Septi-Chek did and was the only culture system positive in 83% of 53 patients, whereas the Septi-Chek system yielded the same results in only 13% of the patients. The Isolator provides a more rapid and sensitive method for the recovery of fungi from blood.
Antibody response to enteric adenovirus types 40 and 41 in sera from people in various age groups
Authors: Shinozaki T , Araki K , Ushijima H , Fujii R
Published: January 2020

A total of 322 single and paired serum samples from children (newborn to 10 years old), young adults (18 to 20 years old), pregnant women and their cord serum samples, and elderly people (more than 70 years old) was tested for antibodies to enteric adenovirus types 40 and 41 by neutralization test. Serum samples were also tested for antibody to the common antigen of adenovirus by enzyme immunoassay. The incidence of antibodies rose gradually through childhood. Antibodies were found in 20% of children between 1 and 6 months old and in 50% of those 37 to 48 months old. Of serum samples from young adults, 48% had antibodies. Antibodies were found in 10% of serum samples from the aged. Of patients with acute gastroenteritis, 19% showed a significant rise in antibody to adenovirus type 40 or 41 or both, and 42% of the same serum samples had a significant rise in antibody to rotavirus by enzyme immunoassay. None of the serum samples tested was negative to adenovirus common antigen.
Combined genetic transformation and nutritional assay for identification of Moraxella nonliquefaciens
Authors: Juni E , Heym G A , Maurer M J , Miller M L
Published: January 2020

A combined genetic transformation and nutritional assay is described that permits definitive identification of clinically isolated strains of Moraxella nonliquefaciens. Crude DNA preparations of strains of various Moraxella species were used to transform nutritional mutants of a stably competent strain of M. nonliquefaciens for ability to grow on a defined medium (Mn-B). DNA samples from 24 independently isolated strains of M. nonliquefaciens all resulted in massive (4+) transformation of each of two mutant assay strains. DNA samples from strains of M. bovis and M. lacunata frequently gave weak (1+) transformation of one of the mutant assay strains (Mn64) but almost always failed to transform another assay strain (Mn136). DNA samples from eight other Moraxella species failed completely to transform either of the mutant assay strains. When streaked on the defined medium used for the transformation assay (Mn-B), 23 of the 24 strains of M. nonliquefaciens grew well, but all strains of M. bovis and M. lacunata failed to grow on this medium.
Sensitive reverse transcriptase assay to detect and quantitate human immunodeficiency virus
Authors: Lee M H , Sano K , Morales F E , Imagawa D T
Published: January 2020

A sensitive biochemical assay of viral reverse transcriptase (RT) was developed that is useful for both the detection and quantitation of human immunodeficiency virus (HIV), the agent responsible for acquired immune deficiency syndrome in humans. This assay gave a 20- to 40-fold increase in enzyme activity over the current method used for RT detection of HIV. The test is based on a previous biochemical study showing the unusual stability of avian oncornavirus RNA-dependent DNA polymerases at 30 degrees C for at least 2 days. Our study shows that the HIV polymerase is stable at 30 to 37 degrees C for up to 3 days. By using this sensitive RT assay, as few as 250 HIV virions can be quantitated directly in tissue culture medium. This assay should prove useful in studies in which the detection of HIV or the quantitation of the number of virions is required.
Comparison of agar disk diffusion, microdilution broth, and agar dilution for testing antimicrobial susceptibility of coagulase-negative staphylococci
Authors: Smith J A , Henry D A , Bourgault A M , Bryan L , Harding G J , Hoban D J , Horsman G B , Marrie T , Turgeon P
Published: January 2020

A collection of 120 oxacillin-susceptible and 120 oxacillin-resistant coagulase-negative staphylococci (CNS) from six tertiary care hospital laboratories were tested by agar disk diffusion, three microdilution broth systems (Sensititre, Dynatech, and Alpkem), and the Vitek AutoMicrobic system for comparison with reference agar dilution results. The antimicrobial agents tested were oxacillin, cefazolin, cefotaxime, cefuroxime, cefamandole, fusidic acid, rifampin, and vancomycin. Incubation was at 30 or 35 degrees C for 24, 48, and 72 h. The broth media were supplemented with 2% NaCl for some antimicrobial agents, and the agar dilution method was used with and without the addition of 4% NaCl. The CNS were identified to species by the method of Kloos and Schleifer. The results showed a lack of concordance between two hospitals with respect to oxacillin susceptibility testing by agar dilution with no NaCl supplement. The reasons are not clear but may be related to variations in media. The 4% NaCl supplement or extended incubation to 48 h eliminated this difference. The cefazolin and cefotaxime susceptibility results in the agar disk diffusion test were unreliable if accepted at face value. Cefamandole testing correlated well with the reference method regardless of the method used, and salt supplementation is not recommended. Most of the oxacillin-resistant CNS were resistant to the other beta-lactam drugs except cefamandole. Of 22 CNS resistant to cefamandole, 21 were S. haemolyticus.
Detection of antibodies to human immunodeficiency virus by latex agglutination with recombinant antigen
Authors: Riggin C H , Beltz G A , Hung C H , Thorn R M , Marciani D J
Published: January 2020

Recombinant human immunodeficiency virus (HIV) env antigen was attached to polystyrene particles, and these complexes were used to develop the first latex agglutination assay for antibodies to HIV. A total of 95 positive and 116 negative human serum samples were assayed for antibodies to HIV by latex agglutination, and results were compared with those of a commercial enzyme immunoassay. Latex agglutination was also compared with, and found to be completely concordant with, Western blot (immunoblot) analysis with virion antigens.
Disseminated Geotrichum candidum infection
Authors: Kassamali H , Anaissie E , Ro J , Rolston K , Kantarjian H , Fainstein V , Bodey G P
Published: January 2020

The pathogenicity of the fungus Geotrichum candidum in humans has not been clearly defined. A patient with acute leukemia who developed a fatal disseminated G. candidum infection while neutropenic is described. At autopsy examination, this patient was misdiagnosed on the basis of histopathology as having disseminated candidiasis until G. candidum was isolated from postmortem culture specimens. The emergence of this organism as an occasional pathogen in leukemic patients is of interest and illustrates the importance of obtaining fungal cultures. There is a need for more effective drugs for antifungal prophylaxis and therapy.
Rapid MIC testing with the sensititre autoreader
Authors: Staneck J L , Allen S D , Harris E E , Tilton R C
Published: January 2020

Automated microdilution MIC results, obtained with the Autoreader (Sensititre, Inc., Salem, N.H.) following 5 h of incubation, were compared with manually read, concurrent control MICs following 18 h of incubation in a three-laboratory comparative study. A total of 704 members of the family Enterobacteriaceae or similar gram-negative organisms were tested against 17 antimicrobial agents. Autoreader MICs were within 1 doubling dilution of control values in 92.9% of instances. Discrepancies of +/- 2 doubling dilutions and +/- 3 or greater doubling dilutions were noted in 4.5 and 2.6%, respectively, of the 7,687 drug-organism combinations analyzed. The majority of errors occurred when beta-lactam antimicrobial agents were tested with a variety of different species. MICs at 5 h, when Pseudomonas aeruginosa was used, were possible in only half the isolates tested and yielded data on only a limited number of drugs in the remaining instances. Excluding results obtained with penicillin and ampicillin, which were uniformly poor, Staphylococcus aureus Autoreader values were within +/- 1 doubling dilution of control values in 93.6% of instances, 5.4% varied by +/- 2 dilutions, and only 1% of test values by +/- 3 or more dilutions from control values for 82 isolates tested against nine antimicrobial agents. Of eight additional S. aureus isolates tested that were resistant to methicillin, only one was read correctly by the Autoreader, with results on the remaining seven appearing as either insufficient growth or as total resistance to all drugs tested. Interlaboratory reproducibility was excellent for selected isolates of S. aureus and gram-negative bacilli. The accuracy of the Sensititre Autoreader MIC results was comparable to that of other same-day quantitative systems for members of the family Enterobacteriaceae and S. aureus, while the economic and procedural advantages of the broth microdilution method was maintained.
Specificities and sensitivities of three systems for determination of antibodies to human immunodeficiency virus by electrophoretic immunoblotting
Authors: Blomberg J , Klasse P J
Published: January 2020

Electrophoretic immunoblotting (EIB [Western blotting]) has emerged as the major method for verification of seropositivity for human immunodeficiency virus (HIV) and therefore needs to be thoroughly characterized. The specificities of three EIB systems, our own and two commercial systems, were studied with anticellular sera and serial dilutions of human sera. We demonstrated that in one system, anti-HLA classes I and II gave bands comigrating with viral proteins, which can be controlled by EIB with uninfected H9 cells. In addition, animal antisera, including anti-immunoglobulin enzyme conjugates, occasionally reacted with HIV gag proteins, necessitating appropriate controls. Whereas none of 10 blood donors reacted at the standard dilution in serum (1/100 or 1/400) in any of the three systems, 6, 1, and 2 of 10 donors reacted with p24, p55, or both at a dilution of 1/10 for the three systems tested. Thus, nonspecific reactions can arise in several ways and justify critical EIB interpretation. The sensitivity of the three systems was studied by comparative titrations and direct quantification of bound immunoglobulin G (IgG). In the titrations with all three, the minor anti-HIV bands p53 and p64, coded from pol, were often detectable in higher dilutions than were antibodies to any other HIV protein. The minimum visible amounts of IgG bound per HIV protein band estimated by extra- and interpolation in densitometric curves and liquid scintillation counting of radiolabeled patient IgG were approximately 0.1, 0.05, and 0.02 ng per band in the three systems. One of the commercial systems had both the highest sensitivity and highest specificity.
Fatty and mycolic acids of Mycobacterium malmoense
Authors: Valero-Guillén P , Martín-Luengo F , Larsson L , Jimenez J , Juhlin I , Portaels F
Published: January 2020

The fatty acids and mycolic acids of 16 clinical isolates of Mycobacterium malmoense were studied by gas chromatography and thin-layer chromatography. All strains contained 2-methyleicosanoic and 2,4,6-trimethyltetracosanoic acids and alpha-, alpha'-, and keto-mycolic acids. The reported findings suggest that lipid analysis is a very useful approach in the species identification of M. malmoense.
Genome typing of mouse adenoviruses
Authors: Hamelin C , Jacques C , Lussier G
Published: January 2020

Restriction endonuclease cleavage site analysis was used to differentiate between mouse adenovirus (MAV) types 1 and 2 strains. Viral DNA of suitable purity and quantity for multiple enzymatic digestions was obtained from cloned CMT-93 mouse tumor cells infected with each type of MAV. Clear differences between the MAV-1 (FL) and MAV-2 (K87) genomes were observed after cleavage with restriction enzymes such as BglII, EcoRI, and PaeR7. Fast electrophoresis of DNA fragments in miniature agarose slab gels allowed rapid and unequivocal identification of the MAV strains. This relatively simple and accurate method should be quite useful to determine the different modes of transmission of mouse adenoviruses and their presence in various animal populations.
Fusarium proliferatum as an agent of disseminated infection in an immunosuppressed patient
Authors: Summerbell R C , Richardson S E , Kane J
Published: January 2020

Fusarium proliferatum was reported as the agent of a fatal disseminated infection in a child with lymphoblastic leukemia. The fungus has not been reported previously to cause disease in humans, but it is closely related to the known opportunistic pathogen F. verticillioides. It was distinguished by the production of clavate microconidia in chains from proliferating phialides. Resistance to amphotericin B and flucytosine in vitro was shown.
Bacteriological findings of acute maxillary sinusitis in young adults
Authors: Jousimies-Somer H R , Savolainen S , Ylikoski J S
Published: January 2020

Bacteriological findings in 339 sinus secretions obtained by puncture were investigated in 238 young adult patients with acute maxillary sinusitis. Aerobic and anaerobic cultures were performed immediately. A total of 76% of the secretions were positive. The most common pathogens isolated were Haemophilus influenzae (50%), Streptococcus pneumoniae (19%), Streptococcus pyogenes (5%), and Branhamella catarrhalis (2%). Coagulase-negative staphylococci and Staphylococcus aureus were isolated in 8 and 1% of the specimens, respectively. The staphylococci were almost invariably present in low numbers and, therefore, probably represented nasal contamination. Other aerobic species were found only occasionally. Anaerobes were isolated in 5% of the secretions. In one-half of these, a low concentration of Propionibacterium acnes was the sole anaerobe that was found, and it was usually mixed with a facultative organism (suggestive of contamination with nasal flora). Only 2% of the sinuses were considered to have true anaerobic infections (high concentrations of several species typical of anaerobic infection), indicating that anaerobes are not a significant cause of acute maxillary sinusitis in a young adult population. The high recovery of H. influenzae in this study indicates that aminopenicillins may be more appropriate choice than conventional penicillin in the antimicrobial therapy of acute maxillary sinusitis (only 2 of 168 H. influenzae strains produced beta-lactamase).
Detection of human calicivirus antigen and antibody by enzyme-linked immunosorbent assays
Authors: Nakata S , Estes M K , Chiba S
Published: January 2020

Enzyme-linked immunosorbent assays (ELISAs) were developed to detect human calicivirus (HCV) antigen and antibody to HCV. The ELISAs were specific for HCV and as sensitive as a previously developed radioimmunoassay. These ELISAs were used to search for evidence of HCV infection in the United States, where HCV gastroenteritis has rarely been reported. One hundred sixty-three stool samples collected from children hospitalized with diarrhea were examined; one sample was positive in the ELISA. Typical calicivirus particles were found in this stool sample, and these particles reacted with a hyperimmune guinea pig anti-HCV serum by immune electron microscopy. The age-related acquisition of antibody to HCV in hospitalized infants and children (from birth to 19 years old) without gastroenteritis and in healthy adults was also evaluated. The pattern of acquisition of antibody to HCV was similar to that for group A rotaviruses, namely, beginning in infancy and becoming 100% by the age of 4 years. These data suggest that HCV is associated with infantile gastroenteritis in the United States, that infections with HCV are common, and that many infections with HCV (Sapporo strain) may not require hospitalization.
Immunoblot analysis of serologic response to outer membrane proteins of Escherichia coli in elderly individuals with urinary tract infections
Authors: Nicolle L E , Ujack E , Brunka J , Bryan L E
Published: January 2020

We used immunoblotting to examine the serologic antibody responses to outer membrane proteins (OMP) of Escherichia coli in both symptomatic and asymptomatic elderly subjects with urinary tract infections. Controls with no present or past urinary tract infections showed variable weak immunoglobulin G (IgG) antibodies to OMP of infecting strains. Elderly individuals with asymptomatic infections demonstrated antibody to both lipopolysaccharide (LPS) and OMP of their infecting strain, with consistent cross-reactivity to OMP of other infecting strains. Young females with acute pyelonephritis showed an IgG response to LPS and OMP with cross-reactivity to OMP of other strains. Elderly individuals with symptomatic invasive infections had strong reactions to both LPS and OMP in specimens collected during the acute phase, generally with an increase in intensity in specimens from convalescent patients. They also demonstrated extensive cross-reactivity to LPS and OMP from all other infecting strains. IgM antibody was not observed in any patients. These data confirm other reports of low levels of antibodies to OMP of E. coli in normal populations. Asymptomatic bacteriuria in this population is associated with antibody responses to the LPS and OMP of the infecting strain. Elderly individuals with invasive infections had initial reactions to the infecting strain with an apparent increase in intensity during convalescence. Antibodies to the major OMP appear to be broadly cross-reactive.
Oral infections and septicemia in immunocompromised patients with hematologic malignancies
Authors: Bergmann O J
Published: January 2020

To estimate the role of oral infections during septicemic episodes in immunocompromised patients with hematologic malignancies, 78 febrile episodes in 46 patients were monitored with daily clinical and microbiological investigations. The 19 septicemic episodes did not differ from the 59 other febrile episodes in the qualitative composition of the aerobic and facultatively anaerobic oral microflora or in the presence of teeth or acute oral infections on day 1. The oral prevalence rates of members of the family Enterobacteriaceae were higher on days 10, 11, and 12 in the febrile episodes with septicemia when compared with those of febrile episodes without septicemia. The prevalence of a probable oral focus in septicemia was 10.5%, and the prevalence of a probable or possible oral origin in septicemia was 31.6%. The results suggest that prevention and elimination of oral infections may reduce the morbidity and perhaps even the mortality in these patients.
Identification of mycobacteria from culture by using the Gen-Probe Rapid Diagnostic System for Mycobacterium avium complex and Mycobacterium tuberculosis complex
Authors: Musial C E , Tice L S , Stockman L , Roberts G D
Published: January 2020

Commercially available kits (Mycobacterium avium Complex Rapid Diagnostic System and Mycobacterium tuberculosis Complex Rapid Diagnostic System; Gen-Probe, Inc., San Diego, Calif.) utilizing nucleic acid hybridization for the rapid identification of members of the M. avium-M. intracellulare complex and M. tuberculosis complex were evaluated by using 339 clinical and American Type Culture Collection (Rockville, Md.) isolates. The tests, which can be performed in approximately 2 h, use specific [125I]DNA probes complementary to the rRNAs of M. avium, M. intracellulare, and M. tuberculosis complex, the latter of which includes M. tuberculosis, M. bovis, M. bovis BCG, M. africanum, and M. microti. The M. avium-M. intracellulare probes correctly identified 99 of 114 M. avium-M. intracellulare isolates, with 7 false-negatives and 8 false-positives, for a sensitivity of 93.4% and a specificity of 96.6%. After repeat testing, 110 of 114 were correctly identified, with 4 false-negatives and no false-positives, for a sensitivity of 96.5% and a specificity of 100%. The M. tuberculosis complex probe correctly identified 99 of 102 M. tuberculosis isolates, with 1 false-negative and 2 false-positives, for a sensitivity of 99% and a specificity of 99.2%. After repeat testing, 100 of 102 isolates were correctly identified, with no false-negatives and 2 false-positives, for a sensitivity of 100% and a specificity of 99.2%. Overall, there were 15 discrepant M. avium-M. intracellulare results, with 4 such results after repeat testing, and 3 discrepant M. tuberculosis complex results, with 2 such results after repeat testing. The Gen-Probe kits are highly sensitive and specific for use in identifying M. avium-M. intracellulare complex and M. tuberculosis complex isolates and will be useful in the clinical laboratory which can use the present radionuclide-containing kits cost effectively.