bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of proteinase in the formation of inhibitory levels of hematin by group A streptococcus cultures on blood-containing media
Authors: Hynes W L , Tagg J R
Published: January 2020

Group A streptococci were tested for proteinase production and for the possible relationship of this production to the generation of bacteriocinlike inhibitor activity. Of 126 strains tested, 83% were positive for proteinase, and a similar distribution was found among strains isolated in association with rheumatic fever (89%) and nephritis (94%) and from uncomplicated acute infections (78%). Although application of an inhibitor production (P) typing scheme demonstrated a variety of P types, all of the proteinase-positive strains produced inhibitory activity and over 65% of these strains were P type 204. It was shown that hematin was responsible for this P type 204 activity and that it was produced only by actively proteolytic strains when grown on a hemoglobin-containing medium. Conditions optimizing proteinase production (anaerobic incubation at 37 degrees C on a test medium prepared from Columbia agar base [GIBCO Laboratories, Grand Island, N.Y.]) increased P type 204 activity. Interference with proteinase activity either by growth of the cultures at an alkaline pH or by incorporation of sub-growth inhibitory concentrations of either iodoacetic acid or lincomycin into the medium prevented production of P type 204 activity. Whether significant conversion of hemoglobin to hematin occurs in vivo and the possible implications of this conversion with regard to the pathogenesis of group A streptococcal infections remain to be determined.
Effect of storage temperature and pH on the stability of antimicrobial agents in MIC trays
Authors: Hwang J M , Piccinini T E , Lammel C J , Hadley W K , Brooks G F
Published: January 2020

Twelve antimicrobial agents, ampicillin, aztreonam, cefamandole, cefazolin, cefonicid, ceforanide, ceftazidime, ceftizoxime, ceftriaxone, cefuroxime, ciprofloxacin, and norfloxacin, were prepared at pH 6.80 and 7.31 in microdilution trays for storage at 4, -10, -25, and -70 degrees C and for weekly susceptibility testing. All 12 drugs had stable biological activity when stored at -70 degrees C for 1 year. All but ampicillin and aztreonam were stable at -25 degrees C. Storage at -10 degrees C was least satisfactory. Desiccation occurred at 4 degrees C, but short-term storage at this temperature is possible since the antimicrobial agents are stable for up to several months.
Production of elastase and other exoproducts by environmental isolates of Pseudomonas aeruginosa
Authors: Nicas T I , Iglewski B H
Published: January 2020

Pseudomonas aeruginosa isolates from environmental sources and bacteremic patients were compared for their levels of elastolytic activity. No significant differences were found. The incidence of production of toxin A, phospholipase C, alkaline protease, and elastase among the environmental strains was also as high as that previously reported for clinical isolates.
Phosphatase activity as a criterion for differentiation of oral mycoplasmas
Authors: Shibata K , Totsuka M , Watanabe T
Published: January 2020

Phosphatase activity was found to be applicable as a criterion for the differentiation of Mycoplasma salivarium and Mycoplasma orale, predominant constituents of oral mycoplasmal flora. Therefore, a simple procedure for the phosphatase activity assay was established as a screening test for the differentiation of oral mycoplasmas.
Percoll-purified Treponema pallidum, an improved fluorescent treponemal antibody-absorbed antigen
Authors: Hanff P A , Fernandez C , Folds J D
Published: January 2020

Percoll-purified Treponema pallidum was evaluated as a fluorescent treponemal antibody-absorbed antigen. Borderline and false-positive reactions were essentially eliminated, resulting in sensitivity and specificity of 100 and 95.5%, respectively. The lack of background debris improved the ease and speed of reading the test.
Critical evaluation of amdinocillin disk susceptibility tests correlated with agar dilution tests
Authors: Barry A L
Published: January 2020

Tests with 10-micrograms amdinocillin disks were performed in parallel with agar dilution tests and three different ranges of inoculum density. A resistance breakpoint of less than or equal to 13 mm and an intermediate category of 14 to 16 mm are recommended. Susceptible strains provided zones greater than or equal to 17 mm in diameter, but many appeared to be resistant by the agar dilution methods if the inoculum exceeded 10(4) CFU per spot.
Prevalence of Chlamydia trachomatis lung infection in patients with acquired immune deficiency syndrome
Authors: Moncada J V , Schachter J , Wofsy C
Published: January 2020

Brush biopsies and lung lavages were obtained from 263 individuals with acquired immune deficiency syndrome who collectively had 658 hospitalizations for pneumonia. Chlamydia trachomatis was isolated during three (0.5%) of the episodes, indicating that it was not an important respiratory tract pathogen in this population.
Osteolytic phaeohyphomycosis in a German shepherd dog caused by Phialemonium obovatum
Authors: Lomax L G , Cole J R , Padhye A A , Ajello L , Chandler F W , Smith B R
Published: January 2020

Phialemonium obovatum was found to be the cause of osteomyelitis in a German shepherd dog. Histologic examination of the biopsied material from the left tibia revealed septate, irregularly branched hyphae, swollen cells, and ovate-to-spherical cells divided by a transverse septum. The majority of the fungal elements were hyaline, but a few had lightly pigmented cell walls that had a greenish yellow tint. The presence of melanin in the cell walls of the hyphae and especially in their septa was verified by the use of the Fontana-Masson silver stain. P. obovatum formed moist, off-white-to-ochraceous, spreading colonies with a characteristic green pigment on their reverse side. The pigment was more prominent in cultures grown at 37 degrees C than in those grown at 25 degrees C. The isolate also grew at 40 degrees C. The dog isolate produced characteristic adelophialides without conspicuous collarettes and also basal septa from the creeping vegetative hyphae growing on the surface of the medium. The numerous obovate phialoconidia were smooth and one-celled.
Rapid detection of cytomegalovirus in bronchoalveolar lavage specimens by a monoclonal antibody method
Authors: Martin W J , Smith T F
Published: January 2020

Cytomegalovirus (CMV), a common cause of pneumonia in immunocompromised subjects, is conventionally diagnosed in the laboratory by tube cell culture assays or by detection of characteristic inclusions in histologic sections. Of 160 immunocompromised patients, CMV infection was diagnosed in 19 subjects by bronchoalveolar lavage (BAL), using a monoclonal antibody directed against an early nuclear antigen of the virus. Cytospin preparations from BAL and MRC-5 cell cultures inoculated with the BAL specimens yielded positive results for 6 (31.6%) and 18 (94%) of the 19 subjects, respectively, within hours of the bronchoscopic procedure, whereas conventional tube cell cultures were positive for 11 of the 19 subjects (57.9%) only after an average of 9.3 days. The monoclonal antibody method permitted easy and rapid detection of CMV in BAL specimens.
Enumeration, isolation, and species identification of mycoplasmas in saliva sampled from the normal and pathological human oral cavity and antibody response to an oral mycoplasma (Mycoplasma salivarium)
Authors: Watanabe T , Matsuura M , Seto K
Published: January 2020

Saliva samples collected from 393 subjects with and without oral diseases were examined for concentrations of mycoplasmas and Mycoplasma species. Mycoplasmas were isolated from 383 (97%) of the 393 subjects. Viable counts ranged from zero to 7.6 X 10(7) CFU/ml (median, 6.9 X 10(4)) and were significantly (P less than 0.01) higher in diseased subjects, except for those with arthrosis temporomandibularis, than in controls. Of 1,400 isolates, 897 (64%), 442 (30%), and 8 (1%) were identified as Mycoplasma salivarium, M. orale, and M. hominis, respectively, and the remaining 73 isolates (5%) were unidentifiable. More than two-thirds of the isolates from diseased subjects versus only half from controls were identified as M. salivarium. In diseased subjects other than those with ostitis (especially those with arthrosis temporomandibularis), the incidence of M. salivarium was higher than that of M. orale, whereas the former occurred about as frequently as the latter in the controls. Antibodies to M. salivarium were also measured in sera from some subjects by the metabolism inhibition test. Sera with metabolism inhibition titers of 16 or greater were rated positive. There was no significant difference in the prevalence of antibodies between diseased subjects (60%) and controls (40%), but the mean titers (97 to 220) of all positive sera from diseased subjects were two to four times those for sera from controls. In addition, a fourfold or greater rise or fall of antibody titers to the organism was shown in paired sera from some subjects. On the basis of these results, M. salivarium was strongly suggested to participate etiologically in some cases of oral infection.
Comparison of blood-free medium (cyclodextrin solid medium) with Bordet-Gengou medium for clinical isolation of Bordetella pertussis
Authors: Aoyama T , Murase Y , Iwata T , Imaizumi A , Suzuki Y , Sato Y
Published: January 2020

Cyclodextrin solid medium (CSM) developed by us was evaluated to be a suitable synthetic medium for the clinical isolation of Bordetella pertussis when compared with Bordet-Gengou (BG) medium. The addition of 5 micrograms of cephalexin (CEX) per ml to CSM not only supported the good growth of B. pertussis but also sufficiently suppressed the growth of nasopharyngeal flora. During period 1 of this study, nasopharyngeal specimens from 60 patients with clinical pertussis were inoculated on CSM supplemented with 5 micrograms of CEX per ml. The isolation rate was 70% (42 of 60). To confirm the efficacy of CSM, another study was performed. During period 2 of this study, nasopharyngeal specimens were cultured on both CSM and BG medium, each with 5 micrograms of CEX per ml. The comparative isolation rates were 100% (40 of 40 specimens from 29 patients) on CSM with 5 micrograms of CEX and 65% (26 out of 40) on BG medium with 5 micrograms of CEX. The excellent efficacy of CSM as measured by the isolation rate was thought to be due to the poor nutrition of this medium for the growth of nasopharyngeal bacteria. CSM retained its efficacy in clinical isolations even after 3 months of storage in a refrigerator. These data led us to conclude that CSM with 5 micrograms of CEX was much better than BG medium with 5 micrograms of CEX, determined by both the isolation rate and preservativity considerations, and that CSM with 5 micrograms of CEX per ml can be successfully used instead of BG medium as a medium for the clinical isolation of B. pertussis.
Comparison of detection of antibody to the acquired immune deficiency syndrome virus by enzyme immunoassay, immunofluorescence, and Western blot methods
Authors: Gallo D , Diggs J L , Shell G R , Dailey P J , Hoffman M N , Riggs J L
Published: January 2020

There was 100% agreement between enzyme immunoassay (EIA) (Abbott Laboratories), Western blot, and indirect immunofluorescence (IF) when these three methods were used to measure antibody to the acquired immune deficiency syndrome (AIDS) virus in sera from 142 high-risk individuals, indicating that IF was a sensitive alternative method for detecting antibody to this agent. Thirty-two (64%) of 50 EIA-positive plasma specimens from a blood bank and 6 (21%) of 28 EIA-positive sera from alternative testing sites were negative by IF. In addition, two EIA-negative sera from the latter group were positive by IF. Western blotting agreed with IF on those 40 specimens which gave discrepant results by EIA and IF. The IF method was determined to be equal to Western blotting in sensitivity and specificity for detection of AIDS antibody, and it was found to be useful for confirming positive EIA results, especially in specimens from individuals in low-risk groups.
Occurrence and distribution of serotypes of the Arizona subgroup of Salmonella strains in the United States from 1967 to 1976
Authors: Weiss S H , Blaser M J , Paleologo F P , Black R E , McWhorter A C , Asbury M A , Carter G P , Feldman R A , Brenner D J
Published: January 2020

The Salmonella Arizona subgroup contains gram-negative enteric bacteria that are closely related to other salmonellae biochemically, serologically, and genetically. Although the Arizona subgroup may be isolated from a wide variety of nonhuman and human sources, the arizonae are uncommonly recognized as human pathogens, and surprisingly little is known about their epidemiology. From 1967 through 1976, the Centers for Disease Control received 858 Arizona subgroup cultures from human and nonhuman sources representing 143 different serotypes in 33 somatic groups; several serotypes had not been previously reported. The 374 cultures from humans represent 71 different serotypes; extraintestinal isolates were present in 31 (44%) serotypes. Compared with data from a previous 20 years of surveillance, the proportion of Arizona subgroup strains isolated from stools, blood, and other sites was remarkably stable, but several serotypes showed marked changes in their frequency of isolation. In total, the ratio of extraintestinal to intestinal isolates was 0.37, but marked serotype-specific variation was noted, suggesting differences in virulence associated with serotype.
Direct identification and susceptibility testing by the AutoMicrobic system of gram-negative bacilli from urine specimens
Authors: Wellstood S A
Published: January 2020

A total of 1,800 urine specimens were screened by Gram stain to detect bacteriuria. Pellets of bacteria were obtained by centrifuging specimens containing greater than or equal to 1 gram-negative bacillus of a single morphological type per oil immersion field. Direct susceptibility tests and identifications were performed from pellets by using the AutoMicrobic system (AMS). Results were compared with culture results by routine AMS methods. Of the 145 specimens showing only gram-negative bacilli on Gram stain, 113 grew greater than or equal to 10(5) CFU of a single species per ml. Compared with routine AMS identifications, the direct method correctly identified 105 (92.9%) of the isolates. Identifications were available within 8 h for 77% of the isolates. When compared by MICs, 93.2% of the direct susceptibility test results agreed with routine AMS results within one twofold dilution. Comparisons by category call indicated that overall complete and essential agreements were 89.9 and 97.8%, respectively, with 1.0% very major, 1.0% major, and 8.1% minor errors. Cefamandole and cephalothin had the lowest correlations by both comparisons. Within 8 h, susceptibility results were available for 94.3% of the isolates. This method offers the advantage of rapid detection, prompt processing, and earlier reporting of complete results for positive urine specimens.
Detection of an Anaplasma marginale common surface protein present in all stages of infection
Authors: Palmer G H , Barbet A F , Kuttler K L , McGuire T C
Published: January 2020

The establishment and maintenance of anaplasmosis-free cattle herds is impaired due to the lack of a rapid, sensitive, and specific serologic test to detect persistently infected cattle which serve as carriers for the organism. To develop an improved diagnostic test for anaplasmosis we screened Anaplasma marginale initial body proteins to identify a protein common to antigenically different isolates that is recognized by the host immune system at all stages of infection. Seronegative cattle were infected with either the Florida, Virginia, or North Texas isolate of A. marginale and monitored for infection by daily examination of Wright-stained blood smears for parasitized erythrocytes. Sera from cattle at different stages of infection, from acute through persistent, were used to immunoprecipitate A. marginale proteins that were metabolically radiolabeled with [35S]methionine or surface radiolabeled with 125I. Multiple A. marginale proteins were recognized by using sera either undiluted or at 1:10; however, only four or five proteins were sufficiently antigenic to elicit antibody reactive with a 1:1,000 serum dilution. A single protein with an apparent molecular mass of 86 kilodaltons was consistently recognized at all stages of infection regardless of the isolate used to infect the cattle. This protein was demonstrated to be on the surface of the A. marginale initial body and to be water soluble. We propose use of this 86-kilodalton protein to develop an improved serologic test for diagnosis of bovine anaplasmosis.
Production of "Asao toxin" by Aeromonas strains isolated from feces and drinking water
Authors: Notermans S , Havelaar A , Jansen W , Kozaki S , Guinée P
Published: January 2020

Cultures of Aeromonas species were tested for production of a toxin recently purified by Asao et al. (T. Asao, Y. Kinoshita, S. Kozaki, T. Uemura, and G. Sukaguchi, Infect. Immun. 46:122-127, 1984) and described as a hemolysin with enterotoxic and cytotoxic activity. The toxin was produced by only 63% of Aeromonas sobria strains and by 93% of Aeromonas hydrophila strains. Also, 54% of A. hydrophila strains produced another cytotoxic entity.
Influence of technical factor variations on serum inhibition and bactericidal titers
Authors: Woolfrey B F , Lally R T , Tait K R
Published: January 2020

The influence of technical factor variations on serum bactericidal and serum inhibitory titers was studied by using Staphylococcus aureus clinical isolates versus oxacillin-spiked human serum. Parallel tests, both with and without the use of beta-lactamase in count plates to inactivate oxacillin carryover, were performed with a conventional macrodilution approach, a carefully controlled macrodilution procedure, and a standard microdilution method. Careful control of technical factor variations diminished the incidence of low serum bactericidal titers and decreased the dispersion of results, a finding corollary to the known influence of technical factor variations on the measurement of MBCs. The incorporation of beta-lactamase into count plates resulted in a shift of serum bactericidal titers to lower values. The microdilution method appeared to be least influenced by technical variations and, with the addition of beta-lactamase to count plates, provided the best results.
Rapid diagnosis of respiratory adenovirus infections in young adult men
Authors: Lehtomäki K , Julkunen I , Sandelin K , Salonen J , Virtanen M , Ranki M , Hovi T
Published: January 2020

Rapid viral diagnosis was attempted in 106 military conscripts with pneumonia and in 101 military conscripts with other types of respiratory infections. Nasopharyngeal suction specimens (NPS) were assayed for viral antigens by immunofluorescence and enzyme immunoassay (EIA). Sputum specimens from 97 pneumonia patients were assayed for viral antigens by EIA. Also, 71 NPS and 13 sputum specimens were examined for the presence of adenovirus DNA by a sandwich hybridization (HYB) method. The reference test was adenovirus isolation in cell culture from the NPS. Adenoviruses were isolated from 6 pneumonia patients and from 20 patients with other respiratory infections. Of these 26 NPS, rapid diagnosis was successful in 13, 16, and 14 cases by EIA, immunofluorescence, and HYB, respectively. Four antigen-positive specimens were found among the 181 specimens which were negative by virus isolation. Sputum was found to contain adenovirus antigen by EIA in 5 of 97 tested specimens. Of these 97 specimens, 13 were selectively tested in HYB, and a positive signal was observed in 4 cases. Serological testing of paired sera revealed 23 adenovirus infections in the pneumonia group and 42 in the group with other respiratory infections. Other viral infections were found only sporadically. All rapid virus detection methods showed excellent specificity but had a lower sensitivity (60%) than virus isolation. Our results show that rapid methods for diagnosing respiratory adenovirus infections can be successfully used in selected groups of adults.
Gastrointestinal carriage of methicillin-resistant Staphylococcus aureus
Authors: Rimland D , Roberson B
Published: January 2020

Nasal and rectal cultures were taken from all patients with methicillin-resistant Staphylococcus aureus identified on routine cultures obtained because of clinical indications. Of 117 patients studied over a 3-year period, 70 (60%) had rectal colonization and 62 (53%) had nasal colonization. Rectal colonization, probably reflecting gastrointestinal carriage, may be a source of transmission of methicillin-resistant S. aureus in hospitalized patients and may be difficult to eradicate.
Incubation time, second blind passage, and cost considerations in the isolation of Trichomonas vaginalis
Authors: Smith R F
Published: January 2020

In a group of 247 symptomatic and asymptomatic women, 75 (30.3%) were found to harbour Trichomonas vaginalis; 39 (52%) infections were detected by wet mount and 36 (48%) were detected by culture only. Of the latter, 27 produces a positive culture in 3 days or less and 9 were positive, on average, at day 6. The break even cost of culture was $6.75 per patient. Among 70 wet mount-negative, primary culture-negative specimens that received a blind passage, another 3 (4.2%) positive cultures were detected.
Detection of specific immunoglobulin M antibodies to cytomegalovirus by using monoclonal antibody to immunoglobulin M in an indirect immunofluorescence assay
Authors: Zerbini M , Musiani M , Gentilomi G , La Placa M
Published: January 2020

The detection of immunoglobulin M (IgM) antibodies to cytomegalovirus-induced late antigens by an indirect immunofluorescence assay was improved by the use of monoclonal antibodies to human IgM. Nonspecific background fluorescence was absent, facilitating the reading of the slides and the detection of a specific fluorescence reaction in sera with low levels of specific IgM. Moreover, the indirect immunofluorescence assay with monoclonal antibodies to IgM proved more sensitive than the indirect immunofluorescence assay with polyclonal antibodies to IgM. The absorption of human sera on staphylococcal protein A avoided false reactions due to the presence of rheumatoid factor and high levels of specific IgG in test sera.
Morphology and ultrastructure of fungi in extended-wear soft contact lenses
Authors: Simmons R B , Buffington J R , Ward M , Wilson L A , Ahearn D G
Published: January 2020

Filamentous fungi of the genera Acremonium, Aspergillus, Alternaria, Cladosporium, Curvularia, and Fusarium penetrated the matrix of soft contact lenses both during normal usage and in laboratory studies. Growth of the fungi within the lens matrix increased with increasing water content of the lens. Hyphae within the lens were coiled. Some species penetrated completely through the lens within 96 h. More frequent cleaning and disinfection of extended-wear soft contact lenses is recommended.
Routine evaluation of the nonradiometric BACTEC NR 660 system
Authors: Courcol R J , Fruchart A , Roussel-Delvallez M , Martin G R
Published: January 2020

The present study compares the sensitivity, accuracy, and practicability of a nonradiometric blood culture system with those of the standard blood culture system in use in our laboratory. A total of 1,080 sets of four blood cultures bottles were compared, giving 143 positive aerobic-medium associations and 139 positive anaerobic-medium associations. The conventional system recovered 171 isolates, whereas the BACTEC NR 660 system (Johnston Laboratories, Towson, Md.) recovered 155 isolated. There were no significant differences in total isolates with either system (P more than 0.05). The BACTEC NR 660 system recovered a slightly lower number of Serratia marcescens and Streptococcus faecalis but a higher number of Pneumococcus spp. The mean detection times were 55.9 h with the conventional system and 31.6 h with the BACTEC NR 660 system (P less than 0.001). Our results demonstrate that the BACTEC NR 660 system is suitable for routine use.
Comparative evaluation of enzyme-linked immunosorbent assay for the diagnosis of pulmonary echinococcosis
Authors: Wattal C , Malla N , Khan I A , Agarwal S C
Published: January 2020

An enzyme-linked immunosorbent assay was done for the detection of immunoglobulin G and M (IgG and IgM) antibodies to Echinococcus granulosus in surgically proved cases of hydatidosis, especially pulmonary hydatidosis, by use of human hydatid cyst fluid antigen and soluble scolex antigen. This assay was compared with the following standardized techniques: the indirect hemagglutination test, the indirect immunofluorescent antibody test, and Casoni's intradermal test. The enzyme-linked immunosorbent assay, with either of the antigens (human hydatid cyst fluid or soluble scolex antigen), was more sensitive and specific than the other techniques in diagnosing cases of hydatidosis, especially hydatid disease of the lung.
Evaluation of avian-human reassortant influenza A/Washington/897/80 x A/Pintail/119/79 virus in monkeys and adult volunteers
Authors: Clements M L , Snyder M H , Buckler-White A J , Tierney E L , London W T , Murphy B R
Published: January 2020

A reassortant influenza A virus was produced by mating an avian influenza A/Pintail/Alberta/119/79 (H4N6) virus with wild-type human influenza A/Washington/897/80 (H3N2) virus. The avian-human influenza A reassortant virus contained the genes coding for the hemagglutinin and neuraminidase surface antigens of the human influenza wild-type virus and the six other RNA segments (internal genes) of the avian influenza A virus donor. In the lower respiratory tract of squirrel monkeys, this avian-human influenza reassortant virus, like its avian influenza A parent virus, was restricted approximately 100-fold in replication compared with the wild-type human influenza A virus. Despite this restriction of replication, infection of monkeys with the avian-human influenza A reassortant virus induced resistance to wild-type human influenza A virus challenge. In comparison with the wild-type human influenza A virus, the avian-human influenza A reassortant was also fully attenuated when 10(5.5) to 10(7.5) 50% tissue culture infective doses were administered to susceptible adult volunteers. Attenuation was indicated by a more than 300-fold reduction in virus shedding and lack of reactogenicity. The reassortant virus did not spread to susceptible contacts and could not be isolated from the blood or stools of infected adults. The 50% human infectious dose was 10(6.2) 50% tissue culture infective dose, indicating that this reassortant virus is only slightly less infectious for adults than a similarly derived avian-human influenza A/Washington/80 X A/Mallard/78 reassortant virus. These findings suggest that the avian influenza A/Pintail/79 virus may be a satisfactory donor of attenuating genes for production of live, attenuated avian-human influenza A reassortant virus vaccines.
Associated mortality and clinical characteristics of nosocomial Pseudomonas maltophilia in a university hospital
Authors: Morrison A J , Hoffmann K K , Wenzel R P
Published: January 2020

We studied the spectrum of clinical disease in 99 patients with nosocomial Pseudomonas maltophilia isolates at the University of Virginia Hospital from 1981 through 1984. The annual rate of isolation increased from 7.1 to 14.1 per 10,000 patient discharges. A crude mortality rate of 43% was documented in all patients from whom the organism was cultured, and the data include 12 patients with nosocomial bacteremia (four deaths). Risk factors associated with death for patients having a P. maltophilia isolate included the following: requirement for care in any intensive care unit during hospitalization (P = 0.0001), patient age over 40 years (P = 0.002), and a pulmonary source for the P. maltophilia isolate (P = 0.003). All P. maltophilia isolates were susceptible to trimethoprim-sulfamethoxazole, 60% of the isolates were resistant to all aminoglycosides (amikacin, tobramycin, and gentamicin), and more than 75% of the isolates were resistant to all beta-lactam antibiotics. The antibiotic susceptibility pattern allows for a niche exploitable in the hospital microbial environment by an organism with a marked associated mortality.
Unusual expression of new low-level-trimethoprim-resistance plasmids
Authors: Young H K , Jesudason M V , Koshi G , Amyes S G
Published: January 2020

In a survey, 42% of trimethoprim-resistant clinical members of the family Enterobacteriaceae were able to transfer trimethoprim resistance to standard Escherichia coli strains when selection was made on complex bacteriological media. When transfer experiments were performed with minimal medium, another 16% of the clinical strains were shown to have transferred trimethoprim resistance. Twelve transconjugants produced negligible trimethoprim resistance in complex media but were resistant in minimal medium. The methionine, glycine, and purine components of complex media appeared to be responsible for the reduced expression of trimethoprim resistance in these strains.
Isolation and characterization of a common antigen in Campylobacter jejuni and Campylobacter coli
Authors: Mills S D , Bradbury W C , Penner J L
Published: January 2020

Flagellin protein was isolated and purified from two serotype reference strains of Campylobacter jejuni, Pen 1 and Pen 3. Each preparation was shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to consist of a diffuse band with a molecular mass of approximately 62 kilodaltons. Antisera were prepared against flagellin from Pen 1, and specific antibody was isolated by affinity chromatography with flagellin protein covalently bound to cyanogen bromide-activated Sepharose. The high-affinity antibody was used to immune blot purified flagellin from Pen 1 and Pen 3, as well as whole-cell preparations and acid-glycine extracts from the 60 reference strains of the thermostable antigen serotyping system. From each of the 60 strains, a protein with a molecular mass of approximately 62 kilodaltons was identified which shared a common antigenic determinant. When the affinity-purified antibody was used in a coagglutination assay, washed whole cells were not agglutinable unless they had been pretreated with an acid buffer (glycine-hydrochloride [pH 2.0]). This indicated that the antigenic determinant common to strains of both C. jejuni and Campylobacter coli may not be exposed in the native state.
High-performance liquid chromatographic analysis of bacterial fatty acid composition for chemotaxonomic characterization of oral streptococci
Authors: Tsuchiya H , Sato M , Kato M , Namikawa I , Hayashi T , Tatsumi M , Takagi N
Published: January 2020

A high-performance liquid chromatographic method was developed to analyze the fatty acid composition of bacterial lipids. After saponification of lipids extracted from bacteria, the liberated fatty acids were labeled with a fluorescence reagent, 4-bromomethyl-7-acetoxycoumarin, followed by reversed-phase high-performance liquid chromatographic separation and fluorescence detection. All bacterial fatty acids were simultaneously separated within 30 min and sensitively determined. This method was applied to the chemotaxonomic characterization of oral streptococci. The fatty acid composition of phospholipids and total lipids distinguished Streptococcus mutans from any other species examined and showed that Streptococcus sanguis had a close taxonomic relationship with Streptococcus salivarius.
Elucidation of Strongyloides stercoralis by bacterial-colony displacement
Authors: Panosian K J , Marone P , Edberg S C
Published: January 2020

Two cases of unsuspected Strongyloides stercoralis infection were elucidated by the displacement of bacterial colonies on primary plating media. Observation of primary plates inoculated for the diagnosis of bacterial pneumonia or gastroenteritis revealed that normal flora colonies had been moved and were aligned in a pathway, or track. This unusual colony alignment prompted us to request a stool for the examination of parasites, and S. stercoralis was found. It was concluded that the parasite is capable of motility on agar surfaces, resulting in the displacement of bacterial colonies that make up the normal flora.
Evaluation of the GO Slide (Roche) growth transport system for isolation of Neisseria gonorrhoeae from clinical specimens
Authors: Anand C M , Gubash S M
Published: January 2020

A new growth transport system for the isolation of Neisseria gonorrhoeae from clinical specimens was evaluated. The system, GO Slide (Roche) of F. Hoffmann-La Roche & Co., Basel, Switzerland, showed 88% sensitivity for male urethral specimens and 59% sensitivity for endocervical specimens compared with transport in the Amies transport medium combined with culturing on modified Thayer-Martin medium. The media used appear not to support growth of certain strains of N. gonorrhoeae. recovery and growth-supporting capabilities of this system need to be improved before the system can be used routinely.
Rapid identification of group JK and other corynebacteria with the Minitek system
Authors: Slifkin M , Gil G M , Engwall C
Published: January 2020

Forty primary clinical isolates and 50 stock cultures of corynebacteria and coryneform bacteria were tested with the Minitek system (BBL Microbiology Systems, Cockeysville, Md.). The Minitek correctly identified all of these organisms, including JK group isolates, within 12 to 18 h of incubation. The method does not require serum supplements for testing carbohydrate utilization by the bacteria. The Minitek system is an extremely simple and rapid way to identify the JK group, as well as many other corynebacteria, by established identification schemata for these bacteria.
Screening method for recovery of methicillin-resistant Staphylococcus aureus from primary plates
Authors: La Zonby J G , Starzyk M J
Published: January 2020

A study designed to screen for the presence of methicillin-resistant Staphylococcus aureus from primary plates was conducted from 1 January to 1 September 1985 in a small community hospital. The screening method used a plate of lipovitellin salt mannitol agar and a 4-microgram oxacillin disk incubated at 30 degrees C. Growth of yellow colonies, typical of S. aureus, around the disk without a zone of inhibition was called presumptive methicillin-resistant S. aureus. All susceptibilities were confirmed by using the National Committee for Clinical Laboratory Standards macrodilution technique. Of 224 cultures containing S. aureus, 118 (53%) were positive for methicillin-resistant S. aureus isolates. Of these 118, 111 (94%) were correctly identified from the primary plates as methicillin-resistant S. aureus. Of the 224 isolates, 14 could not be categorized from the primary plates as methicillin-resistant S. aureus due to the small amounts of S. aureus recovered.
Dissociation between serum neutralizing and glycoprotein antibody responses of infants and children who received inactivated respiratory syncytial virus vaccine
Authors: Murphy B R , Prince G A , Walsh E E , Kim H W , Parrott R H , Hemming V G , Rodriguez W J , Chanock R M
Published: January 2020

The serum antibody response of infants and children immunized with Formalin-inactivated respiratory syncytial virus (RSV) vaccine 20 years ago was determined by using an enzyme-linked immunosorbent assay specific for the RSV fusion (F) and large (G) glycoproteins and a neutralization assay. Twenty-one young infants (2 to 6 months of age) developed a high titer of antibodies to the F glycoprotein but had a poor response to the G glycoprotein. Fifteen older individuals (7 to 40 months of age) developed titers of F and G antibodies comparable to those in children who were infected with RSV. However, both immunized infants and children developed a lower level of neutralizing antibodies than did individuals of comparable age with natural RSV infections. Thus, the treatment of RSV with Formalin appears to have altered the epitopes of the F or G glycoproteins or both that stimulate neutralizing antibodies, with the result that the immune response consisted largely of "nonfunctional" (i.e., nonneutralizing) antibodies. Subsequent natural infection of the vaccinees with wild-type RSV resulted in enhanced pulmonary disease. Despite this potentiation of illness, the infected vaccinees developed relatively poor G, F, and neutralizing antibody responses. Any or all of three factors may have contributed to the enhancement of disease in the RSV-infected vaccinees. First, nonfunctional antibodies induced by the inactivated RSV vaccine may have participated in a pulmonary Arthus reaction during RSV infection. Second, the poor antibody response of infants to the G glycoprotein present in the Formalin-inactivated vaccine may have been inadequate to provide effective resistance to subsequent wild-type virus infection. Third, the relatively reduced neutralizing antibody response of the infant vaccinees to wild-type RSV infection may have contributed to their enhanced disease by delaying the clearance of virus from their lungs.
Disk diffusion susceptibility testing of two macrolide antimicrobial agents: revised interpretive criteria for erythromycin and preliminary guidelines for roxithromycin (RU 965)
Authors: Jones R N , Barry A L , Fuchs P C , Thornsberry C
Published: January 2020

The 15-micrograms erythromycin disk was twice evaluated for interpretive accuracy against 417 and then 266 strains of gram-positive cocci, Neisseria meningitidis, and Haemophilus influenzae by using the criteria suggested by the National Committee for Clinical Laboratory Standards. These studies suggest a revision of streptococcal and Staphylococcus sp. interpretive guidelines to criteria (greater than or equal to 23 mm = susceptible, less than or equal to 13 mm = resistant) that are more compatible with in vivo erythromycin concentrations. It is also recommended that zone diameters be modified for H. influenzae (greater than or equal to 23 mm = susceptible, less than 22 mm = resistant) and that meningococci not be tested. A wide moderately susceptible category (1.0 to 4.0 micrograms/ml) would primarily include enterococcus strains and those organisms that would then respond only to parenteral administration of erythromycin. Roxithromycin (RU 965 or RU 28965), a new oxime ether erythromycin derivative, was also evaluated by investigator-prepared 15-micrograms disks and later with 30- and 60-micrograms commercial disks. Although roxithromycin was comparable to erythromycin in activity and regression line statistics, changes in the susceptible disk criteria were necessary because of superior roxithromycin serum concentrations and a longer serum half-life. Preliminary susceptible breakpoint criteria were greater than 21 mm = susceptible, 10 to 20 mm = indeterminate, and less than or equal to 9 mm = resistant. By using the recommended interpretive criteria for both macrolides, less than 98% absolute agreement was obtained, therefore suggesting the application of a spectrum class concept.
Microscopic agglutination and polyacrylamide gel electrophoresis analyses of oral anaerobic spirochetes
Authors: Tall B D , Nauman R K
Published: January 2020

Microscopic agglutination (MA) analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used to determine strain and species similarities and dissimilarities among three species of oral anaerobic spirochetes, Treponema denticola, Treponema pectinovorum, and Treponema vincentii. The MA analysis revealed a diversity of serologic reactivity or sharing of common antigens within each species. However, there was no cross-reactivity or sharing of common antigens among the three species. Distinct SDS-PAGE whole-cell electrophoretograms for each species were obtained. The banding patterns for 16 T. denticola strains revealed 30 distinct proteins, while the banding patterns for 5 strains of T. pectinovorum and 2 strains of T. vincentii revealed 26 and 35 distinct proteins, respectively. Analysis of the electrophoretograms showed that their respective banding patterns could be used to distinguish the three species from one another. In addition, strain differences within each species could be detected. There was a correlation between MA analysis and SDS-PAGE analysis. It is thus suggested that both MA and SDS-PAGE analysis be included in classification schemes for the identification of oral spirochetes.
Variation and adaptation of Pseudomonas aeruginosa toxicity to HeLa cells and fibroblasts
Authors: Müller H , Kettelhack C , Kettelhack M , Sonntag H G , Keilich G , Brossmer R , Richards J , Kinzel V , Bäuerlein E , Pech H
Published: January 2020

The toxic components of supernatants from Pseudomonas aeruginosa cultures directed against HeLa cells and Staphylococcus aureus were evaluated with the aim of discovering interactions. Supernatants of eight different strains of P. aeruginosa were assayed for cytotoxic activity. All were active against HeLa cells; seven were toxic for S. aureus. On repeated suspension of P. aeruginosa in 0.9% sodium chloride solution, a shift from HeLa cell toxicity to staphylococcal lytic activity occurred along with a change of toxic activity from a high (50,000 +/- 5,000) to a low (8,000 +/- 400) molecular weight (MW) range on gel filtration. Addition of protein to the minimal medium of cultures producing material toxic only for S. aureus reactivated the generation of HeLa cell-toxic material. Cultivation of P. aeruginosa in the presence of HeLa cells and a chloramphenicol supplement produced suppression of the generation of material toxic for S. aureus but facilitated that of HeLa-toxic material of high MW. Adaptation of toxicity against fibroblasts developed only on cocultivation of P. aeruginosa together with S. aureus and in the presence of fibroblasts. Under these conditions a strong lytic activity for S. aureus appeared, even in the presence of chloramphenicol. Chloramphenicol caused the material toxic for fibroblasts to elute at a low MW well separated from that toxic for HeLa cells. In contrast to the high-MW toxic substances, the low-MW material did not induce antibodies after injection into rabbits. This may explain failures of vaccination against P. aeruginosa infection and of serum therapy of homologous sepsis in humans.
Rapid microprocedure for isolating detergent-insoluble outer membrane proteins from Haemophilus species
Authors: Carlone G M , Thomas M L , Rumschlag H S , Sottnek F O
Published: January 2020

A rapid microprocedure for isolating detergent (sodium N-lauroyl sarcosinate)-insoluble major outer membrane proteins from Haemophilus species produced results qualitatively identical to those obtained with a commonly used preparative isolation procedure. Proteins isolated by both procedures were compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis after staining with Coomassie brilliant blue R-250. The time for outer membrane protein isolation was substantially reduced with the rapid procedure, allowing a larger number of membrane preparations to be obtained rapidly for routine analysis.
Pig skin as test substrate for evaluating topical antimicrobial activity
Authors: Bush L W , Benson L M , White J H
Published: January 2020

The feasibility of using pathogen-contaminated pig skin as a model substrate for evaluating skin disinfectants was demonstrated. A test methodology is described that is safe, convenient to use, and adaptable to a variety of hand-washing conditions. The treatment protocol, pathogen contamination conditions, and application technique variables can all be carefully controlled to simulate clinical use conditions. The number of organisms transferred by contact was compared with the total organism count on the pig skin. The quantity of organisms transferred ranged from 10 to 60% of the total organisms, depending on the nature of the contamination conditions. The cumulative results of multiple imprint and stripping measurements were consistent with the concentration of inoculated organisms. Tests with alcohol solutions validated the methodology and clearly showed the dependence of topical antimicrobial activity on both the concentration and structure of the alcohol. Activity increased with increasing alcohol concentration and in the following order: ethanol, isopropanol, and n-propanol. All of the alcohols became less active as the severity of the test conditions was increased, i.e., higher inoculum levels for a longer incubation time before treatment. The contact imprint and stripping methods used to evaluate bacterial growth on the skin clearly showed that the alcohol treatments reduced but did not eliminate the inoculated pathogens. It was found that long lifetimes (several hours) for pathogens on the skin are possible under some environmental conditions. This observation strongly suggests that frequent hand washing is a necessary infection control practice even when opportunities for repeated pathogen contamination have not occurred.
Isolation of Mycoplasma species and Ureaplasma urealyticum from obstetrical and gynecological patients by using commercially available medium formulations
Authors: Phillips L E , Goodrich K H , Turner R M , Faro S
Published: January 2020

One hundred duplicate endocervical specimens from obstetrical and gynecological patients were cultured for Mycoplasma spp. and Ureaplasma urealyticum. Rates of recovery of these organisms from commercially prepared A7 medium and the Mycotrim-GU system were compared. We detected 14 (93%) of the total 15 isolates of Mycoplasma spp. on A7 plates and 11 (73%) in the Mycotrim-GU system. We detected 34 (89%) of the total 38 isolates of U. urealyticum on A7 plates and 32 (84%) in the Mycotrim-GU system. The times of detection for both types of organism were similar in the two systems. We conclude that cultivation on A7 medium as described is a more cost-effective method of recovery of Mycoplasma spp. and U. urealyticum than the Mycotrim-GU system.
Specific immunoglobulin M enzyme-linked immunosorbent assay for confirming the diagnosis of measles
Authors: Lievens A W , Brunell P A
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) was evaluated for the detection of measles virus-specific immunoglobulin M (IgM) (MIgM). The ELISA was standardized by deriving a seronegative range of values from sera which should not contain MIgM (24 cord sera, 59 sera from immune health care workers, and 47 sera from infants before the administration of measles vaccine). These values were separable from those obtained from individuals convalescing from measles. Twenty sera containing rheumatoid factor were MIgM seronegative. Of 30 acute-phase sera from suspected measles cases, 26 contained MIgM; those that were seronegative were obtained on day 0, 0, 2, or 9. All 25 convalescent-phase samples contained MIgM. Of the 25 paired samples, 22 were IgG positive at the first sampling; 3 of the 22 did not show a rise in IgG titer. The MIgM ELISA can be used for confirming suspected measles cases, often requiring only a single serum specimen.