bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of GC-Lect and modified Thayer-Martin media for isolation of Neisseria gonorrhoeae
Authors: Reichart C A , Rupkey L M , Brady W E , Hook E W
Published: January 2020

A new selective medium, GC-Lect, was compared with modified Thayer-Martin medium (MTM) for isolation of Neisseria gonorrhoeae. Cultures from 620 sexually transmitted disease clinic patients were directly inoculated onto both media, placed in candle extinction jars, and incubated. N. gonorrhoeae was isolated from 175 (29%) of 607 genital cultures, 3 (3%) of 88 pharyngeal cultures, and 6 (29%) of 21 rectal cultures. Ten cultures were positive only on GC-Lect, and 3 were positive only on MTM. In 3 of the 10 cultures positive only on GC-Lect, overgrowth of a Capnocytophaga sp. may have obscured growth on MTM. In this study, vancomycin-susceptible (MIC, less than 4.0 micrograms/ml) N. gonorrhoeae was isolated on both media, and none of the isolates missed by either medium were susceptible to vancomycin. No differences were noted between the two media in time required for isolation of N. gonorrhoeae. While isolation rates of N. gonorrhoeae were similar, suppression of nongonococcal bacterial species by GC-Lect was superior to that by MTM. GC-Lect is equal to MTM for detection of N. gonorrhoeae and is superior for suppression of normal flora.
Ingestion and killing of Listeria monocytogenes by blood and milk phagocytes from mastitic and normal cattle
Authors: Czuprynski C J , Noel E J , Doyle M P , Schultz R D
Published: January 2020

Human listeriosis resulting from consumption of listeria-contaminated dairy products is emerging as a significant public health concern. There is a need to understand better the processes involved in the pathogenesis of Listeria monocytogenes-induced bovine mastitis. In the present report, we describe the results of the in vitro interaction of L. monocytogenes with bovine blood and milk leukocytes. Induction of an experimental L. monocytogenes mastitis resulted in a rapid and dramatic increase in neutrophils in the milk of infected cows. Blood neutrophils and mononuclear cells and milk leukocytes from listeria-infected and uninfected cows readily ingested L. monocytogenes in the presence of serum opsonins. These leukocytes also killed a portion of the ingested listeriae. Ingestion of listeriae evoked a vigorous chemiluminescence response by blood neutrophils and a relatively weak response by blood mononuclear cells. Ingestion, killing, and chemiluminescence by milk leukocytes were directly related to the percentage of neutrophils that were present. Blood neutrophils from healthy donor cattle ingested and killed L. monocytogenes when leukocyte-depleted milk and whey from mastitic cows were the sole sources of opsonins, although fewer listeriae were ingested than when normal bovine serum was present. These results indicate that bovine blood and milk phagocytes, like blood and inflammatory phagocytes from other mammalian species, can ingest and kill L. monocytogenes in vitro.
Enzyme immunoassay for anti-hepatitis B core (HBc) immunoglobulin G1 and significance of low-level results in competitive assays for anti-HBc
Authors: Sällberg M , Magnius L O
Published: January 2020

An enzyme immunoassay (EIA) for anti-hepatitis B core (HBc) immunoglobulin G1 (IgG1) was compared with a commercial radioimmunoassay (RIA) for anti-HBc antibody (Corab: Abbott Laboratories, North Chicago, Ill.). In parallel tests of 445 consecutive samples, discrepant results were obtained with 2 samples, 1 of which was positive only by the RIA and the other of which was positive only by the EIA for anti-HBc IgG1. In tests of another 192 samples with low blocking activity in the RIA (inhibition range, 90 to 30%), 10 samples gave discrepant results, 5 of which were positive only by the RIA and the other 5 of which were positive only by the EIA for anti-HBc IgG1. Of 12 samples with discrepant results, 11 samples were tested further for anti-HBc IgG3, IgM, and IgA1 by the EIA. Of these, seven samples were positive for anti-HBc IgG1, anti-HBc IgG3, or both. All seven samples were also positive for anti-hepatitis B surface (HBs) antigen. Three samples were negative for anti-HBc IgG1, anti-HBc IgG3, or both but were positive for anti-HBc IgM, anti-HBc IgA1, or both; and one sample was reactive only in the RIA. These four samples were all negative for anti-HBs. Thus, low-level results in the RIA caused by anti-HBc IgM, anti-HBc IgA, or both reflect the unspecific activation of immature B lymphocytes that is not related to previous exposure to hepatitis B virus (HBV). In contrast, the presence of anti-HBc IgG1, anti-HBc IgG3, or both indicates differentiated anti-HBc IgG-producing plasma cells and previous exposure to HBV, as was also shown by the presence of anti-HBs. On class and subclass determination for confirmation of positivity for anti-HBc in 19 serum samples, which was identified by screening of blood from 1,343 donors by a competitive EIA (Hepanostika; Organon), 9 samples with positive results, all low level, did not indicate previous exposure to HBV. It was concluded that determination of classes and subclasses of anti-HBc provides a tool for discriminating positive anti-HBc results not caused by HBV exposure.
Identification of Neisseria spp., Haemophilus spp., and other fastidious gram-negative bacteria with the MicroScan Haemophilus-Neisseria identification panel
Authors: Janda W M , Bradna J J , Ruther P
Published: January 2020

The Haemophilus-Neisseria identification (HNID) panel (American MicroScan, Sacramento, Calif.) is a 4-h microdilution format system for identification of Haemophilus and Neisseria spp., Branhamella (Moraxella) catarrhalis, and Gardnerella vaginalis. The HNID panel was evaluated by using 423 clinical isolates and stock strains of these organisms, and HNID identifications were compared with those obtained by conventional methods. In addition, 32 isolates representing six genera not included in the HNID data base were tested to determine whether these organisms would produce unique biotype numbers for possible inclusion in the data base. The HNID panel correctly identified 95.3% of 86 Neisseria gonorrhoeae strains, 96% of 25 G. vaginalis strains, and 100% of 28 Neisseria lactamica strains and 48 B. catarrhalis strains. Only 64.7% of 68 Neisseria meningitidis isolates were identified correctly owing to false-negative or equivocal carbohydrate and/or aminopeptidase reactions. Among the Haemophilus spp., 98.8% of 83 H. influenzae strains, 97.1% of 34 H. parainfluenzae strains, and 80% of 15 H. aphrophilus and H. paraphrophilus strains were correctly identified. Eight strains of Neisseria cinerea, a species not included in the data base, produced profiles identical with those for B. catarrhalis and N. gonorrhoeae. Isolates of other species not included in the data base, including Eikenella corrodens, Kingella spp., and Cardiobacterium hominis, produced unique biochemical reaction patterns on the panel. Modification of interpretative criteria for certain tests, expansion of the data base to include other species, and suggestions for additional confirmatory tests will increase the accuracy and utility of the HNID panel.
Clinical, microbiological, and experimental animal studies of Candida lipolytica
Authors: Walsh T J , Salkin I F , Dixon D M , Hurd N J
Published: January 2020

Candida lipolytica was recovered from six patients in three different clinical centers. The index isolate caused a persistent fungemia with catheter-associated Candida thrombophlebitis, the second isolate was from a polymicrobial sinusitis, and the remaining four isolates were involved in tissue colonization. These and 20 other isolates were consistent in their morphological and physiological characteristics. All formed true hyphae and blastoconidia on cornmeal-Tween 80 agar and all assimilated glucose, glycerol, and erythritol. In a murine model of disseminated candidiasis, the index isolate that caused clinical fungemia caused no mortality and produced only two lesions on a kidney, as determined at necropsy. The nine isolates selected for in vitro antifungal susceptibility studies had intermediate susceptibilities to amphotericin B but were susceptible to ketoconazole. We conclude that C. lipolytica is a weakly virulent pathogen which may require an intravascular foreign body to cause fungemia.
Fc receptors on the surface of Toxoplasma gondii trophozoites: a confounding factor in testing for anti-Toxoplasma antibodies by indirect immunofluorescence
Authors: Budzko D B , Tyler L , Armstrong D
Published: January 2020

Negative sera often produce false-positive polar patterns of fluorescence in indirect immunofluorescence tests for serum anti-Toxoplasma gondii antibodies, representing a confounding factor in the diagnosis of toxoplasmosis. In this work, we studied whether T. gondii trophozoites, the antigenic material used in the immunofluorescence tests, expressed surface Fc receptors that could cause the binding of normal immunoglobulins, thus producing false-positive results. We report here that T. gondii trophozoites indeed have Fc receptors on their surface. This was shown by the direct binding of purified human Fc to the parasite, evidenced by the subsequent binding of fluorescein-labeled Fab specific for human Fc. In addition, pretreatment of the parasite with excess purified Fc to saturate the surface Fc-binding sites abrogated the formation of polar fluorescence. The trophozoites appeared to express Fc receptors with different degrees of affinity for the specific ligand, since a diffuse fluorescence pattern was observed following incubation with 1 mg of Fc per ml (10 micrograms per well), whereas with 0.2 mg (0.2 micrograms per well), a majority of parasites showed polar fluorescence. This observation suggests that the Fc receptors accumulated at the polar cap are those with higher affinity. The present findings raise intriguing questions regarding the possible biological role(s) of the Fc receptors on T. gondii but, more immediately, indicated that pretreatment of the antigenic material with Fc, a commercially available reagent, constitutes a practical, simple way to avoid false-positive immunofluorescence test results due to the binding of nonspecific immunoglobulin to the parasite.
Direct testing of blood culture for detection of the serotype 5 and 8 capsular polysaccharides of Staphylococcus aureus
Authors: Boutonnier A , Nato F , Bouvet A , Lebrun L , Audurier A , Mazie J C , Fournier J M
Published: January 2020

Monoclonal antibodies (MAbs) reactive with serotype 5 and 8 capsular polysaccharides of Staphylococcus aureus have been used to test, by enzyme-linked immunosorbent assay (ELISA), blood culture fluids for the presence of S. aureus. A total of 748 blood cultures from 665 patients yielding 706 bacterial isolates belonging to more than 26 bacterial species were studied. All blood cultures containing bacterial strains belonging to species other than S. aureus were negative in ELISA. All 23 blood cultures containing serotype 5 S. aureus were positive in ELISA with the corresponding MAb. Out of 20 blood cultures containing serotype 8 S. aureus, 19 were positive with the corresponding MAb. All 5 blood cultures containing nontypeable S. aureus were negative in ELISA with both MAbs. This method provides reliable identification of serotype 5 or serotype 8 S. aureus by direct testing of blood culture fluids with ELISA.
Clinical features, epidemiology, and treatment of Plesiomonas shigelloides diarrhea
Authors: Kain K C , Kelly M T
Published: January 2020

Recent studies have suggested that Plesiomonas shigelloides is a cause of diarrhea. The present study addresses the clinical features, epidemiology, and response to antimicrobial therapy of P. shigelloides diarrhea. Thirty cases of P. shigelloides infection were defined by isolation of the organism from stool specimens, and 30 age-matched control patients were identified by detection of other enteric pathogens. Clinical and epidemiological information was obtained by interviewing the referring physicians and the patients. Of the P. shigelloides-infected patients, 71% had a history of recent tropical travel, but 29% acquired their infections locally in association with the consumption of seafood or untreated water or both. Seventy-eight percent of the P. shigelloides-infected patients had findings suggestive of colitis, and P. shigelloides-infected patients had a history of tropical travel, acute illness, abdominal pain, and prolonged symptoms significantly more often than did the control patients. Antimicrobial therapy significantly reduced the duration of illness in patients with Plesiomonas diarrhea. These results suggest that P. shigelloides is a significant cause of both locally acquired and traveler's diarrhea that may respond to antimicrobial therapy.
Evaluation of the Abbott TESTPACK RSV enzyme immunoassay for detection of respiratory syncytial virus in nasopharyngeal swab specimens
Authors: Swierkosz E M , Flanders R , Melvin L , Miller J D , Kline M W
Published: January 2020

The Abbott TESTPACK RSV assay (Abbott Laboratories, North Chicago, Ill.), a rapid (20-min) enzyme immunoassay, was compared with culture and direct immunofluorescence (DFA) of nasopharyngeal cells for the detection of respiratory syncytial virus (RSV) in nasopharyngeal swab specimens. Nasopharyngeal swab specimens, collected from 234 infants, were placed in viral transport medium. Portions of specimen in transport medium were used for each test. Of 234 specimens, 70 (30%) were culture positive, 103 (44%) were DFA positive, 107 (46%) were culture or DFA positive, and 112 (48%) were TESTPACK RSV positive. Of 19 specimens positive by TESTPACK RSV but negative by culture or DFA, 15 were positive by the blocking assay. A total of 122 specimens were culture, DFA, or blocking assay positive; TESTPACK RSV detected 108 specimens (sensitivity, 89%). The specificity, positive predictive value, and negative predictive value of TESTPACK RSV as compared with those of culture, DFA, and the blocking assay were 96, 96, and 89%, respectively. By comparison, the sensitivity, specificity, positive predictive value, and negative predictive value of combined culture and DFA were 88, 100, 100, and 88%, respectively. TESTPACK RSV is a rapid and reliable enzyme immunoassay for the direct detection of RSV antigen in nasopharyngeal swab specimens.
Evaluation of a commercial monoclonal antibody-based enzyme immunoassay for detection of adenovirus types 40 and 41 in stool specimens
Authors: Wood D J , Bijlsma K , de Jong J C , Tonkin C
Published: January 2020

A commercial monoclonal antibody-based enzyme immunoassay (Adenoscreen; Mercia Diagnostics Ltd., Guildford, United Kingdom) for the detection of adenovirus types 40 and 41 in stool specimens was evaluated. Two assay modes were tested. In the first, 177 stool samples were screened for the presence of adenovirus type 40 or 41 (assay mode 1). Virus was detected in 79 of 82 specimens positive for adenovirus type 40 or 41 by a polyclonal antibody-based immune electron microscope test, giving a sensitivity of 96.3%. The enzyme immunoassay was negative in 91 of 95 stool samples which contained either other adenovirus serotypes or other viruses or were virus negative. The specificity was thus 95.8%. The positive and negative predictive values of this assay against immune electron microscopy were 95.2 and 96.8%, respectively, and the diagnostic accuracy was 96.0%. Viruses from the three false-negative enzyme immunoassay stool samples were verified as adenovirus type 40 or 41 by restriction enzyme analysis, monoclonal antibody-based immune electron microscopy, or both. Two of the three false-negative stool samples were subsequently concentrated by ultracentrifugation, and one of the two stool samples was then positive by enzyme immunoassay. The third false-negative virus was typed as adenovirus type 41 in the second (serotyping) enzyme immunoassay mode. The four enzyme immunoassay false-positive stool samples all contained other adenovirus serotypes (two were type 2, and two were type 5), but no cross-reactivity was seen with other strains of these serotypes and the results probably reflected simultaneous excretion of adenovirus type 40 or 41 with other adenovirus serotypes. In the second assay mode viruses from 15 stool samples were serotyped. The results by enzyme immunoassay (4 were type 40 and 11 were type 41) correlated completely with previous results from restriction endonuclease analyses. The commercial enzyme immunoassay system showed excellent sensitivity and specificity for the detection of adenovirus types 40 and 41 in stool specimens and will make an important contribution to the accurate diagnosis of adenovirus gastroenteritis.
Evaluation of six media for the growth of Trichomonas vaginalis from vaginal secretions
Authors: Schmid G P , Matheny L C , Zaidi A A , Kraus S J
Published: January 2020

Many media have been formulated for the growth of Trichomonas vaginalis, but the relative sensitivities of these media have not been determined. We evaluated the ability of six media, including all five media commercially available in the United States, to grow Trichomonas vaginalis from vaginal secretions. In a first experiment, we evaluated the ability of five media to grow T. vaginalis from vaginal secretions of 375 women and determined the optimal days on which to read culture tubes, by inoculating aliquots of secretions into each medium and reading the tubes 1, 2, 3, 4, and 7 days later. Sixty-five patients (17%) had a positive wet-mount examination for T. vaginalis, and all the positive results were confirmed by growth in at least one medium. Of 310 wet-mount-negative specimens, 37 (12%) grew T. vaginalis; overall, 102 women (27%) had a positive culture. Diamond and modified Diamond media (the latter being the only medium not commercially available) detected 99 (97%) and 92 (90%) isolates, respectively, compared with three formulations of Kupferberg medium, which detected 77 (75%), 50 (49%), and 43 (42%) isolates. The optimal single day to read wet-mount-negative cultures was day 7, but 4 (11%) of the 37 positive specimens were positive only before day 7. In a second study, we compared the ability of modified Diamond medium with that of a sixth medium, Lash medium, to grow T. vaginalis from 48 wet-mount-positive specimens; modified Diamond medium supported growth in all cases, whereas Lash medium supported growth in only 26 (54%) cases. We conclude that formulations of Diamond medium are superior to formulations of Kupferberg or Lash medium for growth of t. vaginalis.
Polymerase chain reaction assay for detection of human cytomegalovirus
Authors: Olive D M , Simsek M , Al-Mufti S
Published: January 2020

Direct detection of human cytomegalovirus (HCMV) from clinical specimens was examined by using the polymerase chain reaction (PCR) for amplifying HCMV DNA. The efficiency of the amplification reaction was examined by using three different buffers and concentrations of deoxynucleotide triphosphates. The PCR assay was most efficient with a reaction mixture containing 17 mM ammonium sulfate, 67 mM Tris hydrochloride (pH 8.5), 7 mM MgCl2, 10 mM 2-mercaptoethanol, 170 micrograms of bovine serum albumin per ml, and each deoxynucleotide triphosphate at a final concentration of 1.5 mM. After 35 cycles of amplification, 0.15 fg of a plasmid containing the cloned target gene (corresponding to approximately six gene copies) was detected. The PCR assay correctly identified all of 24 clinical isolates of HCMV. Virus in urine specimens could be disrupted by heating at 93 degrees C for 30 min. The viral DNA was amplified directly from 5 microliters of preheated urine, with no further treatment before amplification. We tested the PCR assay on urine specimens from patients who had undergone renal transplantation that had been screened for the presence of HCMV by enzyme-linked immunosorbent assay, hybridization assay, and direct virus isolation. Specimens that were positive by one or more of these assays were screened by PCR. HCMV was consistently detected by PCR in all specimens that were positive by at least one other test. No cross-reactivity to other herpesviruses or MRC-5 cellular DNA was observed.
Comparison of the Oxoid Signal blood culture system with supplemented peptone broth in a pediatric hospital
Authors: Himmelreich C A , Orlando M F , Storch G A
Published: January 2020

We compared the Oxoid Signal bottle (Oxoid, U.S.A.) with supplemented peptone broth (SPB) tubes (B-D Vacutainer; Becton Dickinson Vacutainer Systems) for performing blood cultures in a pediatric hospital. Blood from 3,066 samples was divided equally between the two systems. Of 131 probable pathogens isolated, 121 were detected in the Signal bottle and 111 were detected in the SPB tubes (P greater than 0.05). Of 167 probable contaminants, 122 grew in the Signal bottle and 109 grew in the SPB tubes (P greater than 0.05). The recovery of staphylococci, both probable pathogens and probable contaminants, was increased in the Signal bottle. The recoveries of other organisms, including streptococci, members of the family Enterobacteriaceae, and yeasts, were similar in the two systems. However, the Signal bottle failed to detect three isolates of Haemophilus influenzae, and the time to availability of isolated colonies of other isolates of H. influenzae was delayed. Overall, the Signal bottle was easy and convenient to use, and its innovative detection system should facilitate the early recognition of positive cultures. If its ability to recover H. influenzae can be improved, the Signal bottle could be a useful alternative to existing systems for use in a pediatric setting.
Comparison of methods for diagnosing bacterial vaginosis among pregnant women
Authors: Krohn M A , Hillier S L , Eschenbach D A
Published: January 2020

The diagnosis of bacterial vaginosis is usually based on clinical criteria including homogeneous vaginal discharge, an elevated vaginal pH, the presence of clue cells, and an amine odor. We have evaluated the vaginal flora and clinical signs for 593 pregnant women. Gardnerella vaginalis, Bacteroides spp., and Mycoplasma hominis were isolated more frequently among women with clinical signs than among those without clinical signs of bacterial vaginosis in multivariable analyses that controlled for other bacteria. To determine the laboratory method that best predicted bacterial vaginosis, we calculated the sensitivity, specificity, and predictive value of positive and negative tests for Gram-stained vaginal smears, gas-liquid chromatography of vaginal fluid, and G. vaginalis cultures compared with clinical signs. G. vaginalis culture was sensitive (92%) and both gas-liquid chromatography (78%) and Gram-stained vaginal smears (62%) were moderately sensitive in identifying women with three of the four clinical signs of bacterial vaginosis. However, the Gram-stained vaginal smear (95%) was more specific than G. vaginalis culture (69%) or gas-liquid chromatography (81%). The predictive value of a positive test was also higher for the Gram staining (76%) than for G. vaginalis culture (41%) or gas-liquid chromatography (48%).
Enterotoxin production and serogroups of Campylobacter jejuni and Campylobacter coli from patients with diarrhea and from healthy laying hens
Authors: Lindblom G B , Kaijser B , Sjögren E
Published: January 2020

Enterotoxin production, a possible virulence factor, was determined in Campylobacter jejuni and Campylobacter coli by two different techniques, the CHO cell test and the GM1 enzyme-linked immunosorbent assay. The frequency of enterotoxigenic Campylobacter strains was 32% in strains from both humans with acute enteritis and healthy laying hens, as measured by the CHO cell test. The CHO cell test was significantly more sensitive than the GM1 enzyme-linked immunosorbent assay in the detection of enterotoxigenic strains. Enterotoxin production was compared with the presence of heat-stable and heat-labile antigens. There was no significant correlation between enterotoxin production and serogroups for C. jejuni or C. coli. The difference in enterotoxigenicity between C. jejuni (34.1%) and C. coli (21.9%) was not significant.
Detection of rotavirus by hybridization with a nonradioactive synthetic DNA probe and comparison with commercial enzyme immunoassays and silver-stained polyacrylamide gels
Authors: Arens M , Swierkosz E M
Published: January 2020

Three enzyme-linked immunosorbent assays (ELISAs) (rotavirus enzyme immunoassay [EIA; International Diagnostic Laboratories], Pathfinder [Kallestad Laboratories], and Rotaclone [Cambridge Bioscience, Inc.]) and hybridization of viral RNA with a nonradioactive, synthetic oligonucleotide DNA probe (SNAP; Molecular Biosystems, Inc.) were compared with silver-stained polyacrylamide gel electrophoresis (PAGE) of viral RNA for the detection of rotavirus in fecal specimens. Hybridization was performed following column purification of the viral RNA. Of 286 specimens analyzed by PAGE, SNAP, rotavirus EIA, Pathfinder, and Rotaclone, 88 were positive by PAGE. All 88 specimens were also positive by the other four assays. Nine specimens that were positive by one or more of the assays were positive by blocking ELISAs but were negative by PAGE. If these nine specimens were considered to be true positives, the final sensitivities and specificities were as follows: PAGE, 91 and 100%; SNAP, 94 and 97%; rotavirus EIA, 96 and 97%; Pathfinder, 100 and 94%; and Rotaclone, 96 and 97%, respectively.
Antibodies to staphylococcal peptidoglycan and its peptide epitopes, teichoic acid, and lipoteichoic acid in sera from blood donors and patients with staphylococcal infections
Authors: Wergeland H I , Haaheim L R , Natås O B , Wesenberg F , Oeding P
Published: January 2020

Antibodies to the staphylococcal antigens peptidoglycan, beta-ribitol teichoic acid, and lipoteichoic acid, as well as to the peptidoglycan epitopes L-Lys-D-Ala-D-Ala, L-Lys-D-Ala, and pentaglycine, were found over a wide range of concentrations in sera from both blood donors and patients with verified or suspected staphylococcal infections. The patient group was heterogeneous with regard to both age and type of staphylococcal infections, being representative for sera sent to our laboratory. In single-antigen assays antibodies to pentaglycine had the highest predictive positive value (67%), although only 32% of the patients had elevated levels of such antibodies. Combinations of test antigens could yield positive predictive values as high as 100%, but then the fraction of positive sera was low. Indeed, the fraction of patient sera which was positive in multiple-antigen tests never exceeded 61%. The clinical usefulness of these seroassays for identifying Staphylococcus aureus as a causative agent was limited, owing to the considerable overlap in the range of antibody concentrations between patient and blood donor sera.
Detection of bluetongue virus antigens in Culicoides variipennis by enzyme immunoassay
Authors: el Hussein A , Calisher C H , Holbrook F R , Schoepp R J , Beaty B J
Published: January 2020

A solid-phase enzyme immunoassay (EIA) was developed to detect bluetongue (BT) virus antigens in infected cell cultures and in suspensions of infected Culicoides variipennis midges. The technique was equally sensitive for detecting the five U.S. BT virus serotypes (2, 10, 11, 13, and 17) in cell cultures. EIA reliably detected about 3.8 log10 median tissue culture infective doses per ml of BT virus in infected cell culture lysates. The EIA readily detected virus antigens in pools of midges infected with BT serotypes 2, 10, 11, 13, and 17 and contained 2.3 to 4.8 log10 median tissue culture infective doses per ml of BT virus. The technique was sensitive enough to detect a single infected midge in a pool with 99 noninfected midges. The EIA may be a sensitive and rapid alternative to virus isolation for surveillance of BT viruses in vector populations.
Restriction endonuclease analysis of human and bovine group B streptococci for epidemiologic study
Authors: Denning D W , Baker C J , Troup N J , Tompkins L S
Published: January 2020

Group B streptococci, a frequent cause of neonatal sepsis and meningitis, postpartum endometritis, and bovine mastitis, may be acquired by several modes of transmission. Detailed epidemiologic study is hampered by the lack of a sufficiently discriminatory typing system, especially for type III and nontypable strains. We examined 54 epidemiologically well-characterized strains by restriction endonuclease analysis (REA) and compared the results with those obtained by serotyping. REA patterns were inspected without knowledge of the epidemiological or serotyping data. Among 21 type Ia, Ia/c, and Ib/c isolates, we found 10 REA patterns; among 5 type II and IIc isolates, we found 5 REA patterns; among 13 type III isolates, we found 6 REA patterns; and among 15 nontypable human and animal isolates, we found 7 different REA patterns. Double digestion of type III isolates with EcoRI and BglII helped us to distinguish the isolates. In total, 28 REA patterns were found in six serotype groups and one nontypable group. Some geographically and epidemiologically separate isolates had identical REA patterns, suggesting dissemination of a limited number of clones. We conclude that REA is a promising tool for detailed epidemiological study of group B streptococci.
Serological evidence for variation in the incidence of herpesvirus infections in different species of apes
Authors: Eberle R , Hilliard J K
Published: January 2020

Sera from captive lowland gorillas, chimpanzees, orangutans, and gibbons were screened by enzyme-linked immunosorbent assay (ELISA) for antibody to herpesviruses serologically related to human herpes simplex virus types 1 and 2 (HSV-1, HSV-2), a baboon virus (SA8), and a macaque herpesvirus (B virus). The incidence of herpesvirus antibodies varied considerably among the different species, gorillas having the highest incidence of seropositivity (65.4%) and orangutans the lowest. The virus specificity of positive sera was further analyzed by examining the kinetics of virus neutralization, competition of reactivity in ELISAs, and immunoblotting against HSV-1, HSV-2, SA8, and B virus antigens. Using these assays, the majority of positive gorilla sera (49 of 53, 92%) were determined to react in a manner identical to human HSV-1 immune sera. The remaining four positive gorilla sera reacted as HSV-2-positive sera. In contrast, the majority of positive chimpanzee sera (5 of 7, 71%) reacted as HSV-2 immune rather than HSV-1 immune. All positive sera from gibbon apes reacted as HSV-1 positive. No orangutan sera were identified which gave positive reactions by ELISAs to any of the four primate herpesviruses tested. Although four orangutan sera gave equivocal results against HSV-1 antigen, further analysis by immunoblotting could not confirm any specific reactivity with any of the primate herpesvirus antigens. Varied reactivity among individual animals with both SA8 and B virus proteins was observed, but none of the seropositive primates detected appeared to be infected with either of these simian viruses. Three gorilla sera had antigen recognition patterns slightly different from those of HSV-2-positive human and chimpanzee sera and another HSV-2-positive gorilla serum, raising the possibility that these animals harbor an indigenous virus related to HSV-2.
Amount, avidity, and specificity of antibodies to Pseudomonas aeruginosa in normal human sera
Authors: Grzybowski J , Trafny E A , Wrembel-Wargocka J , Patzer J , Dzierzanowska D , Zawistowska-Marciniak I , Kłos M
Published: January 2020

Seventy-two normal human sera from healthy blood donors were tested by an enzyme-linked immunosorbent assay in order to determine the amounts and avidities of immunoglobulins M and G antibodies to lipopolysaccharides of seven Fisher's immunotypes of Pseudomonas aeruginosa and to exotoxin A. The patterns of specificity for seven immunotypes in all individual sera were determined. These data show a predominance of antibodies directed to Fisher's immunotypes 7 and 4 in the human population tested and may reflect frequency of occurrence of immunotypes outside the hospital environment.
Hepatitis A virus hemagglutination and a test for hemagglutination inhibition antibodies
Authors: Eckels K H , Summers P L , Dubois D R
Published: January 2020

Like enteroviruses, hepatitis A virus (HAV) hemagglutinated various species of erythrocytes under similar conditions. HAV-specific antibodies in both acute- and convalescent-phase sera were found to inhibit hemagglutination. The HAV hemagglutination inhibition test can be used for diagnosis, epidemiological surveillance, and vaccine assessment.
Nasopharyngeal swabs and nasopharyngeal aspirates equally effective for the diagnosis of viral respiratory disease in hospitalized children
Authors: Frayha H , Castriciano S , Mahony J , Chernesky M
Published: January 2020

Paired nasopharyngeal swab and nasopharyngeal aspirate specimens from 125 patients were compared for viral diagnosis. The viral isolation rates were comparable for the two types of specimens. There was a high level of agreement between the two specimens in overall positivity rate by immunofluorescence and positivity in culture-confirmed patients.
Identification of Branhamella catarrhalis in 2.5 min with an indoxyl butyrate strip test
Authors: Dealler S F , Abbott M , Croughan M J , Hawkey P M
Published: January 2020

Branhamella catarrhalis, an occasional cause of human respiratory infections, unlike most other members of the family Neisseriaceae, produces a butyrate esterase. This is capable of breaking the ester linkage between butyryl groups and carrier molecules. B. caviae and B. ovis, which are rarely encountered in pathological specimens, also produce butyrate esterase. This property can be used as a rapid test in the identification of B. catarrhalis. The recently reported rapid test for butyrate esterase relies on the release of methylumbelliferate, which can be detected only by using UV light after 5 min of incubation. In the rapid test described here, indoxyl is liberated from indoxyl butyrate by butyrate esterase and spontaneously forms indigo in the presence of oxygen. B. catarrhalis can be distinguished from other oxidase-positive, gram-negative cocci after 2.5 min by inoculating the organism onto a filter paper strip containing this compound.
Examination of human stomach biopsies, saliva, and dental plaque for Campylobacter pylori
Authors: Krajden S , Fuksa M , Anderson J , Kempston J , Boccia A , Petrea C , Babida C , Karmali M , Penner J L
Published: January 2020

To examine possible sources of Campylobacter pylori and to determine the routes by which it is transmitted to the human stomach, samples of dental plaque and saliva from 71 patients undergoing endoscopy in addition to stomach biopsies were collected and cultured on selective noninhibitory Skirrow medium. A total of 29 (40.8%) of the stomach biopsies yielded C. pylori. None of the saliva samples and only one of the dental plaque samples was found positive for C. pylori, and thus neither saliva nor dental plaque could be implicated as a significant reservoir of this organism.
Capillary gas chromatographic analysis of mycolic acid cleavage products, cellular fatty acids, and alcohols of Mycobacterium xenopi
Authors: Luquin M , Lopez F , Ausina V
Published: January 2020

The fatty acids, alcohols, and mycolic acids of 26 strains of Mycobacterium xenopi were studied by capillary gas chromatography and thin-layer chromatography. All strains contained alpha-, keto-, and omega-carboxymycolates. The primary mycolic acid cleavage product was hexacosanoic acid. The fatty acid patterns and, especially, the presence of 2-docosanol are characteristic markers of M. xenopi.
Effects of sample holding time, temperature, and atmosphere on the isolation of Campylobacter jejuni from dogs
Authors: Monfort J D , Stills H F , Bech-Nielsen S
Published: January 2020

Stool specimens were collected from 39 dogs, inoculated onto Campylobacter blood agar plates, and divided into four subsamples. Subsamples were held at 4 and 25 degrees C in room air and in a microaerobic environment and were reinoculated at 1, 2, 3, 4, 6, and 8 h. C. jejuni survived at least 3 h when it was held at 4 degrees C, but less than 2 h when it was held at 25 degrees C. The holding atmosphere was not associated with a difference in isolation rates.
Yeast killer toxins and dimorphism
Authors: Polonelli L , Conti S , Campani L , Morace G , Fanti F
Published: January 2020

The differential action of four selected yeast killer toxins on the mycelial and yeast forms of four isolates of the dimorphic fungus Sporothrix schenckii was comparatively evaluated. The results confirmed that the yeast killer phenomenon is present among hyphomycetes and yeasts and that both morphological forms of S. schenckii are susceptible to the action of the same yeast killer toxin. Quantitative differences in the response to the killer action of the mycelial and yeast forms in individual strains were also observed. To avoid retroconversion of the dimorphic forms, we used a modification of the conventional killer system.
Limited usefulness of quantitative culture of blood drawn through the device for diagnosis of intravascular-device-related bacteremia
Authors: Paya C V , Guerra L , Marsh H M , Farnell M B , Washington J , Thompson R L
Published: January 2020

The use of a differential quantitative blood culture technique (Isolator) to diagnose intravascular-device-related bacteremia (IDRB) was studied prospectively. During septic episodes in 44 patients, blood was obtained simultaneously through the suspected infected device and from a peripheral venipuncture. The blood samples were processed by the Isolator technique, which enables easy quantification of microorganisms. The cannula was removed, and its tip was cultured semiquantitatively. Of the 52 cannulas studied, 15 were the cause of IDRB, but only 7 of these showed a significantly higher bacterial count in blood obtained through the device compared with peripheral blood. The bacterial count was higher in blood drawn through the device than in peripheral blood in four of six cases that did not fulfill the definition of IDRB. Some blood cultures obtained through the device were positive despite negative cultures of peripheral blood and cannula tips (six cannulas). Quantitative blood cultures were not useful in diagnosing IDRB in this study.
DNA probes for the identification of Haemophilus ducreyi
Authors: Parsons L M , Shayegani M , Waring A L , Bopp L H
Published: January 2020

Haemophilus ducreyi ATCC 33922, a virulent, well-characterized strain, was used to construct a genomic library in a bacteriophage expression vector. Three DNA fragments were selected for use as probes on the basis of their ability to encode H. ducreyi-specific proteins, as demonstrated by reactivity with rabbit polyclonal antiserum. With DNA-DNA hybridization, the three probes, labeled with 32P, reacted strongly with 16 strains of H. ducreyi obtained from a variety of sources. Thirty-seven other bacterial isolates, representing 33 different species and including organisms likely to be encountered in the urogenital tract, were also tested with the three probes. Twenty-eight of these isolates, including the genital pathogen Neisseria gonorrhoeae, showed no hybridization with the probes. In addition, herpes simplex virus-infected tissue culture cells and Treponema pallidum-infected rabbit testicular fluid were also completely nonreactive. Nine isolates, six belonging to other Haemophilus species and three belonging to Pasteurella species, reacted weakly with the probes when approximately 3.0 x 10(7) to 6.0 x 10(7) CFU was tested. When 10(5) to 10(6) CFU of these organisms was tested, the weak reactions could no longer be seen. Yet this number of H. ducreyi still reacted strongly. In fact, the three probes consistently detected 10(4) CFU of H. ducreyi in pure and mixed cultures and even produced a weak signal when only 10(3) CFU was present. It is clear from our results that use of these probes will greatly facilitate the laboratory diagnosis of this genital pathogen.
Detection of Neisseria meningitidis and Yersinia pestis with a novel silicon-based sensor
Authors: Libby J M , Wada H G
Published: January 2020

A light-addressable potentiometric (silicon) sensor was used in an immunofiltration procedure for the detection of pathogenic bacteria. Yersinia pestis was detected by filtering the cells onto nitrocellulose membranes and then filtering anti-Y. pestis mouse monoclonal antibody and anti-mouse immunoglobulin G-horseradish peroxidase conjugate. For Neisseria meningitidis detection, mouse monoclonal antibody to the major outer membrane protein of this bacterium was coupled directly to horseradish peroxidase. N. meningitidis cell suspensions were filtered onto polycarbonate membranes, and the enzyme conjugate was allowed to react with the filtered bacteria. The presence of both enzyme conjugates was determined potentiometrically with the silicon sensor. The sensitivity of this technique relative to that of an enzyme-linked immunosorbent assay for N. meningitidis was determined. Fewer than 1,000 bacterial cells could be detected with the silicon sensor in a 20-min assay, whereas a 2.5-h enzyme-linked immunosorbent assay with the same antigen and antibody preparations was significantly less sensitive.
Antigenic characterization of respiratory syncytial virus associated with acute respiratory infections in Uruguayan children from 1985 to 1987
Authors: Russi J C , Delfraro A , Arbiza J R , Chiparelli H , Orvell C , Grandien M , Hortal M
Published: January 2020

The occurrence of subgroup A and B strains of respiratory syncytial virus (RSV) was studied during three epidemic years, 1985 to 1987, in Uruguay. A set of monoclonal antibodies was selected according to their reactivity with local RSV isolates and used for the typing of RSV directly in nasopharyngeal cells by indirect immunofluorescence. Of 77 specimens, 69 could be typed as belonging to subgroup A or B, 5 could not be typed with the restricted set of monoclonal antibodies employed, and 3 reacted with both subgroup-specific antibodies. In 1985 and 1986 subgroup A predominated, accounting for 65.7% of all typed specimens, but in 1987 subgroup B surpassed subgroup A, accounting for 82.4% of the samples.
Staff carriage of epidemic methicillin-resistant Staphylococcus aureus
Authors: Cookson B , Peters B , Webster M , Phillips I , Rahman M , Noble W
Published: January 2020

Twenty-six nurses were repeatedly screened for carriage of epidemic methicillin-resistant Staphylococcus aureus (EMRSA) immediately before and after duty periods in which they solely attended six patients widely colonized with two EMRSA strains distinguishable by plasmid analysis. EMRSA carriage was detected in 13 nurses. Three EMRSA carriage patterns emerged: transient carriage in 12 nurses, when the EMRSA was isolated from noses or fingers of nurses after duty but was gone before their next day's duty; short-term nasal carriage, seen on occasion in 4 of these 12 nurses, when EMRSA carriage was detected on two consecutive screens; and persistent nasal carriage, seen in 1 nurse only, when the EMRSA was seen on more than two consecutive occasions. All but one of these incidents of carriage could be explained by close patient, rather than environmental, exposure and occurred despite an intensive control programme. Transient or short-term carriage in nurses probably resulted in transfer of the EMRSA between patients. Staff decontamination should be considered following a period of cohort nursing of EMRSA patients, especially if staff members are shortly to nurse unaffected patients. Our findings may explain some of the difficulties in controlling EMRSA.
Detection of Trypanosoma cruzi by DNA amplification using the polymerase chain reaction
Authors: Moser D R , Kirchhoff L V , Donelson J E
Published: January 2020

The polymerase chain reaction was used to amplify a 188-base pair (bp) segment of the repetitive 195-bp nuclear DNA sequence of Trypanosoma cruzi that is the most abundant sequence in this organism. The reaction amplified this repetitive element in four T. cruzi isolates from widely separated geographic regions. No amplification of the 188-bp fragment occurred when DNAs extracted from Leishmania spp., African trypanosomes, or blood samples from mice and humans were used. Amplification of one-half of the DNA from a single T. cruzi parasite produced an amount of the 188-bp element that was readily visible in a gel stained with ethidium bromide. Hybridization of a radiolabeled probe to membrane-bound amplification products increased the sensitivity to a level at which 1/200 of the DNA in a single parasite could be detected. T. cruzi DNA was readily detected in DNA extracted from the abdominal contents of infected insect vectors reared in the laboratory. No parasite DNA was detected in the blood samples of two individuals known to be infected with T. cruzi, possibly because in such patients the number of circulating parasites are extremely low or because parasitemias are intermittent. These results represent a considerable increase in sensitivity over previously reported methods for the detection of T. cruzi infections. Polymerase chain reaction amplification can be used to evaluate large numbers of samples in a single day and thus should be useful in large-scale studies of the prevalence of T. cruzi in both insect vectors and mammalian hosts.
Isolation and biochemical characterization of Haemophilus species isolated simultaneously from the oropharyngeal and anogenital areas
Authors: Martel A Y , St-Laurent G , Dansereau L A , Bergeron M G
Published: January 2020

Several reports have described the high frequency of pharyngeal isolation of Haemophilus species. Few studies have compared the simultaneous isolation rate of this species in the oropharyngeal and anogenital areas. Using two selective media, heart infusion agar (HIA) supplemented with 5% defibrinated rabbit blood, 1% IsoVitaleX, and either bacitracin alone (100 micrograms/ml) or bacitracin (5 micrograms/ml), vancomycin (3 micrograms/ml), and polymyxin B (1 microgram/ml), we isolated Haemophilus species in both areas in 89 of 399 (22.2%) patients consulting a sexually transmitted disease clinic. Of those, 56 were males and 33 were females. We recovered Haemophilus species in the oropharyngeal area in 384 patients (96%), while rectal and genital areas were colonized in 48 (12.0%) and 55 (13.8%) patients, respectively (both areas were colonized in 14 patients). Haemophilus parainfluenzae was isolated almost twice as often in the anogenital area as was H. influenzae. H. influenzae biotypes II and III and H. haemolyticus were the more prevalent XV-requiring haemophili isolated from the oropharynx, while H. influenzae biotype IV was more prevalent in the anogenital area. H. parainfluenzae biotypes I, II, and III were more prevalent in the oropharynx, while biotypes I and II were more prevalent in the anogenital area.
Biotyping of Candida albicans: results of an international collaborative survey
Authors: Odds F C , Auger P , Krogh P , Neely A N , Segal E
Published: January 2020

An agar plate system for biotyping isolates of Candida albicans was evaluated in four laboratories for 18 coded yeast isolates, each tested in triplicate on duplicate series of agar plates. The results showed that the biotyping system gave excellent intralaboratory reproducibility. However, because the concordance of data among laboratories was poor, the method must be regarded as suitable only for research applications and not for routine use.