bluuebunny/crossref_metadata_2025 huggingface dataset:
Prospective Study To Determine Clinical Relevance of Detection of Pneumococcal DNA in Sera of Children by PCR
Authors: Dagan Ron , Shriker Ofra , Hazan Inbal , Leibovitz Eugene , Greenberg David , Schlaeffer Francis , Levy Rachel
Published: December 2019

We undertook a prospective study to evaluate the accuracy of PCR of serum (aimed at the pneumococcal pneumolysin gene) at detecting pneumococcal infections in infants and children. The assay was positive for all blood and cerebrospinal fluid culture-positive samples and for 38 and 44% of patients with lobar pneumonia and acute otitis media, respectively. It was positive for 17% of healthy controls. There was a marked effect of age on the rate of positivity among healthy controls, with the highest rate (33%) being in 2-year-old children, the age group with the highest rate of nasopharyngeal (NP) carriage; the lowest rate was found among infants <2 months of age (13%) and adults ages 18 to 50 years (0%), age groups with the lowest NP pneumococcal carriage rates. Carriers of pneumococci in the nasopharynges had a higher rate of positivity than noncarriers of pneumococci in the nasopharynges for all groups. Our results suggest that although PCR of serum is a sensitive test for the detection of
Streptococcus pneumoniae
in sterile fluids, its high rate of positivity for healthy controls, related to NP pneumococcal carriage, might exclude it from being useful in detecting deep-seated pneumococcal infections.
Evaluation of PCR for Diagnosis of
Bordetella pertussis
and
Bordetella parapertussis
Infections
Authors: Lind-Brandberg Lena , Welinder-Olsson Christina , Lagergård Teresa , Taranger John , Trollfors Birger , Zackrisson Gunilla
Published: December 2019

PCR, using primers PIp1 and PIp2, was evaluated for the detection of DNA from
Bordetella pertussis
in bacterial strains and in nasopharyngeal samples from patients with a cough lasting at least 7 days. The assay could detect DNA from 6 CFU of
B. pertussis
/10 μl of sample. Results of the PCR assay were compared with those of cultures, a determination of serum antibodies against pertussis toxin and filamentous hemagglutinin, and a clinical evaluation of 2,442 coughing episodes. The overall sensitivity of PCR was 65% (623 of 956), which was higher than the sensitivity of cultures (58%) (
P
< 0.001). Factors influencing the sensitivity of PCR were the interval between the onset of symptoms and sampling and the vaccination status of the patient. The specificity of PCR was 98% (1,451 of 1,486). The positive and negative predictive values were 95 and 81%, respectively. Parapertussis PCR, using primers BPPA and BPPZ, was positive in 11 of 18 culture-positive cases and was confirmed by serology in another 4 cases. In conclusion, PCR is a valuable complement to cultures and can probably replace cultures for diagnosis of
B. pertussis
and
Bordetella parapertussis
infections.
Update on
Pneumocystis carinii
f. sp.
hominis
Typing Based on Nucleotide Sequence Variations in Internal Transcribed Spacer Regions of rRNA Genes
Authors: Lee Chao-Hung , Helweg-Larsen Jannik , Tang Xing , Jin Shaoling , Li Baozheng , Bartlett Marilyn S. , Lu Jang-Jih , Lundgren Bettina , Lundgren Jens D. , Olsson Mats , Lucas Sebastian B. , Roux Patricia , Cargnel Antonietta , Atzori Chiara , Matos Olga , Smith James W.
Published: December 2019

Pneumocystis carinii
f. sp.
hominis
isolates from 207 clinical specimens from nine countries were typed based on nucleotide sequence variations in the internal transcribed spacer regions I and II (ITS1 and ITS2, respectively) of rRNA genes. The number of ITS1 nucleotides has been revised from the previously reported 157 bp to 161 bp. Likewise, the number of ITS2 nucleotides has been changed from 177 to 192 bp. The number of ITS1 sequence types has increased from 2 to 15, and that of ITS2 has increased from 3 to 14. The 15 ITS1 sequence types are designated types A through O, and the 14 ITS2 types are named types a through n. A total of 59 types of
P. carinii
f. sp.
hominis
were found in this study.
Detection of Cattle Naturally Infected with
Anaplasma marginale
in a Region of Endemicity by Nested PCR and a Competitive Enzyme-Linked Immunosorbent Assay Using Recombinant Major Surface Protein 5
Authors: Torioni de Echaide Susana , Knowles Donald P. , McGuire Travis C. , Palmer Guy H. , Suarez Carlos E. , McElwain Terry F.
Published: December 2019

A competitive enzyme-linked immunosorbent assay using recombinant major surface protein 5 (rMSP5-cELISA) of
Anaplasma marginale
was validated in a naturally infected cattle herd in an area of eastern Oregon where
A. marginale
is endemic. The true positive and negative
A. marginale
infection status of 235 randomly selected cattle was determined by using a nested PCR (nPCR) coupled with
msp5
sequence analysis and hybridization. Judgment of the reliability of the nPCR and hybridization for detection of persistent infections was based on three observations. First, the nPCR was able to detect as few as 30 infected erythrocytes per ml. Second, the nPCR was able to consistently detect low levels of rickettsemia in seven carrier cattle experimentally infected with
A. marginale
. Third,
msp5
sequence analysis showed >95% identity among 30 nPCR amplicons from cattle naturally infected with field strains of
A. marginale
. The nPCR and hybridization identified 151 infected and 84 uninfected cattle among the 235 animals tested. With a cutoff point of 28%, the rMSP5-cELISA showed a sensitivity of 96% and a specificity of 95%. These results indicate that the rMSP5-cELISA can sensitively and specifically detect cattle with naturally acquired persistent
A. marginale
infections and suggest that it is an excellent assay for epidemiological studies, eradication programs, and regulation of international cattle movement.
Simultaneous Identification of Antibodies toBrucella abortusandStaphylococcus aureusin Milk Samples by Flow Cytometry
Authors: Iannelli Domenico , D’Apice Letizia , Fenizia Domenico , Serpe Luigi , Cottone Carlo , Viscardi Maurizio , Capparelli Rosanna
Published: December 2019

Two flow cytometric assays are described herein. The single cytometric test (SCT) detects antibodies to eitherBrucella abortusorStaphylococcus aureusin the serum or milk of a cow or water buffalo. The double cytometric test (DCT) detects both anti-B. abortusand anti-S. aureusantibodies concurrently. In the SCT, the sample to be tested is incubated in succession with the antigen (eitherB. abortusorS. aureus) and the proper secondary antiserum (fluorescein isothiocyanate-labelled rabbit anti-cow immunoglobulin antiserum or rabbit anti-water buffalo immunoglobulin antiserum). In the DCT, the sample to be tested is incubated first withB. abortusandS. aureusantigens and then with the secondary antiserum. TheB. abortusantigen used in the DCT is covalently bound to 3-μm-diameter latex particles. The difference in size betweenB. abortusandS. aureuspermits the establishment of whether the antibodies are directed against one, the other, or both antigens. When compared to the complement fixation test, the SCT and DCT each show a specificity and a sensitivity of 100%. The SCT has been used previously to detect anti-S. aureusantibodies. Here its use is extended to the detection of anti-B. abortusantibodies. The DCT is described here for the first time. The DCT appears to be useful for large-scale brucellosis eradication programs. It offers the possibility of using one test to identify animals that are serologically positive for bothB. abortusandS. aureus.
Glycogen Assay for Diagnosis of Female Genital
Chlamydia trachomatis
Infection
Authors: Chun Yang , Yin Zhu Dao
Published: December 2019

Chlamydia trachomatis
can synthesize glycogen at various stages in its developmental cycle. The glycogen content of female genital epithelial cells was detected by anthrone, and the results were compared with those from PCR. A total of 320 cervical samples were examined. Of 92 specimens that were positive by PCR, 78 were positive and 14 were negative by the glycogen assay. Of 228 specimens that were negative by PCR, 220 were negative and 8 were positive by the glycogen assay. The sensitivity and specificity of the glycogen assay obtained from these data were 84.8% (78 of 92) and 96.5% (220 of 228), respectively. Use of the glycogen assay to detect the glycogen content in genital epithelial cells may be helpful in the diagnosis of
C. trachomatis
infection. This is an easy, fast, and inexpensive assay and can be done in less-sophisticated labs.
Baculovirus Expression of the Fusion Protein Gene of Bovine Respiratory Syncytial Virus and Utility of the Recombinant Protein in a Diagnostic Enzyme Immunoassay
Authors: Pastey Manoj K. , Samal Siba K.
Published: December 2019

The fusion (F) protein of bovine respiratory syncytial virus (BRSV) was expressed by using a baculovirus vector. Antigenicity was tested by immunofluorescence analysis with F-specific monoclonal and polyclonal antibodies. Antibodies to recombinant F protein raised in a rabbit neutralized BRSV and human respiratory syncytial virus infectivity when tested in a plaque reduction assay. The recombinant F protein was evaluated as a source of antigen in an enzyme-linked immunosorbent assay (ELISA), and this ELISA was compared with the virus neutralization (VN) test for detecting BRSV antibodies in 10 consecutive serum samples from four calves vaccinated with a live modified BRSV vaccine and from two nonvaccinated control calves. The ELISA with the baculovirus-expressed F protein as an antigen compared favorably with the VN test and is a rapid, sensitive, and specific method for detecting serum antibodies to BRSV.
Application of an Optimized and Highly Discriminatory Method Based on Arbitrarily Primed PCR for Epidemiologic Analysis of Methicillin-Resistant
Staphylococcus aureus
Nosocomial Infections
Authors: Olmos Antonio , Camarena Juan J. , Nogueira José M. , Navarro Juan C. , Risen Julia , Sánchez Roberto
Published: December 2019

The optimization of an arbitrarily primed PCR method for typing 96 methicillin-resistant
Staphylococcus aureus
(MRSA) isolates was compared with pulsed-field gel electrophoresis. Identical results in the differentiation of MRSA clones and identification of the main cluster that included 82 strains (88% of patients) were obtained by both techniques.
Chromogenic Tube Test for Presumptive Identification or Confirmation of Isolates asCandida albicans
Authors: Merlino John , Tambosis Evanthia , Veal Duncan
Published: December 2019

This report describes a new, modified, simple, and cost-effective method for the use of CHROMagar Candida (CHROMagar Company, Paris, France) for the presumptive identification of isolates asCandida albicansafter preliminary growth. Sixty randomly selected clinical isolates were evaluated, including 38 ofC. albicans. With incubation at 37°C for 24 h, the sensitivity and specificity appeared to be excellent and the test performed better than the traditional germ tube test. However, at earlier times,C. tropicalisisolates gave false-positive results.
Evaluation of Pyloriset Screen, a Rapid Whole-Blood Diagnostic Test for
Helicobacter pylori
Infection
Authors: Oksanen Aino , Veijola Lea , Sipponen Pentti , Schauman Knut-Olof , Rautelin Hilpi
Published: December 2019

Helicobacter pylori
infection can be detected by several invasive tests based on gastroscopy and by noninvasive methods such as serologic assays. Noninvasive tests can be used not only in addition to invasive tests but also by themselves to screen for
H. pylori
infection in patients who are not in urgent need of endoscopy. Lately, rapid qualitative serologic tests have been developed. In the present study, the accuracy of a novel rapid whole-blood test, Pyloriset Screen, detecting immunoglobulin G (IgG) and IgA antibodies against
H. pylori
was evaluated. A total of 207 consecutive adult outpatients referred for upper endoscopy were enrolled. Gastric biopsy specimens were taken from the antrum and corpus for histologic examination and rapid urease testing. Cultures were available for 113 patients. Serum samples collected from all patients were tested for
H. pylori
antibodies by two enzyme immunoassays (EIAs) (Pyloriset EIA and an in-house EIA), a rapid latex agglutination test (Pyloriset Dry), and Pyloriset Screen. Patients were considered
H. pylori
positive if helicobacters were seen on histologic examination (77 patients) or, if in combination with histologically verified (although helicobacter-negative) gastritis, their IgG antibody titers were elevated in the two EIAs (five patients). The Pyloriset Screen test had a sensitivity of 95%, a specificity of 94%, a positive predictive value of 91%, and a negative predictive value of 97%. Among 63 patients under the age of 45 years, the Pyloriset Screen test did not miss a single
H. pylori
diagnosis, and only 1 patient had a false-positive result. Pyloriset Screen could be used reliably to screen for
H. pylori
infection.
Identification of
Lactococcus garvieae
by PCR
Authors: Zlotkin Amir , Eldar Avi , Ghittino Claudio , Bercovier Herve
Published: December 2019

Lactococcus garvieae
(junior synonym
Enterococcus seriolicida
) is an emerging zoonotic agent isolated from economically important fish (rainbow trout and yellowtail), from cattle, and from humans. Clindamycin susceptibility is the only phenotypic test which can differentiate
L. garvieae
from
Lactococcus lactis
, another emerging agent in humans. A PCR assay for the identification of
L. garvieae
was developed and resulted in an amplified fragment of 1,100 bp in size. The PCR assay was shown to be specific to
L. garvieae
. The PCR assay was positive for all the
L. garvieae
strains tested, which originated from three different continents (Asia, Australia, and Europe). The PCR assay was negative for the phenotypically similar
L. lactis
and for all the other fish pathogens tested, including
Streptococcus iniae
and
Aeromonas salmonicida
. The PCR assay was applied to plasma obtained from diseased animals and was found sensitive enough to detect bacteria from 1 μl of plasma. The PCR assay that was developed is the only practical test besides the clindamycin test which can specifically identify the zoonotic agent
L. garvieae
and which can differentiate it from
L. lactis.
Genotypic Characterization of Seven Strains ofMycoplasma fermentansIsolated from Synovial Fluids of Patients with Arthritis
Authors: Schaeverbeke Thierry , Clerc Maïthé , Lequen Laurence , Charron Alain , Bébéar Cécile , de Barbeyrac Bertille , Bannwarth Bernard , Dehais Joël , Bébéar Christiane
Published: December 2019

We performed a genotypic characterization of seven strains ofMycoplasma fermentanswhich have been isolated from the synovial fluid of patients with rheumatoid arthritis (n= 2), spondyloarthropathy (n= 1), and unclassified arthritis (n= 4). We compared them to three reference strains (strains PG18 and K7 and incognitus strain) and to a clinical isolate from the urethra of a patient with nongonococcal urethritis. The characterization methods included electrophoresis of native DNA, arbitrarily primed PCR, and restriction fragment length polymorphism analysis following conventional and pulsed-field gel electrophoresis. Southern blot analysis with a probe internal to an insertion sequence was performed with the restriction products produced by the last two techniques. No extrachromosomal DNA sequences were detected. TheM. fermentansstrains identified by these methods did not present a unique profile, but they could be separated into two main categories: four articular isolates were genetically related to PG18 and the three other isolates, the urethral isolate, and the incognitus strain were related to K7. We also looked for the presence of the bacteriophage MAV1 (associated with the arthritogenic property ofMycoplasma arthritidisin rodents) in theM. fermentansstrains. MAV1 DNA was not detected in either the clinical isolates or the reference strains ofM. fermentans.
Specificity of Rabbit Antisera against Lipopolysaccharide ofAcinetobacter
Authors: Pantophlet Ralph , Brade Lore , Dijkshoorn Lenie , Brade Helmut
Published: December 2019

Acinetobacterhas been reported to be involved in hospital-acquired infections with increasing frequency. However, clinical laboratories still lack simple methods that allow the accurate identification ofAcinetobacterstrains at the species level. For this study, proteinase K-digested whole-cell lysates from 44 clinical and environmental isolates were investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with hyperimmune rabbit sera to examine the possibility of developing a serotyping scheme based on the O antigen ofAcinetobacterlipopolysaccharide (LPS). The antisera, obtained by immunization of rabbits with 13 of the heat-killed isolates investigated, were characterized by Western blotting and enzyme immunoassay by using proteinase K-digested whole-cell lysates and phenol-water-extracted LPS as antigens. In both assays, the antisera were shown to be highly specific for the homologous antigen. In addition, assignment ofAcinetobacterLPS to the smooth or the rough phenotype was shown not to be reliable when it was based only on the results obtained with silver-stained gels. O-antigen reactivity, determined by Western blot analysis, was observed with 11 of the 31 isolates, most of which belonged to the speciesAcinetobacter baumannii(DNA group 2) and the unnamed DNA group 3. Interestingly, some O antigens were found in a DNA group different from that of the strain used for immunization. The results indicate that O serotyping ofAcinetobacterstrains is feasible and thus may provide a simple method for the routine identification of these opportunistic pathogens.
Nonperinatal Nosocomial Transmission of
Candida albicans
in a Neonatal Intensive Care Unit: Prospective Study
Authors: Reef Susan E. , Lasker Brent A. , Butcher Dona S. , McNeil Michael M. , Pruitt Ruth , Keyserling Harry , Jarvis William R.
Published: December 2019

Nosocomial
Candida albicans
infections have become a major cause of morbidity and mortality in neonates in neonatal intensive care units (NICUs). To determine the possible modes of acquisition of
C. albicans
in hospitalized neonates, we conducted a prospective study at Grady Memorial Hospital, Atlanta, Ga. Clinical samples for fungal surveillance cultures were obtained at birth from infants (mouth, umbilicus, and groin) and their mothers (mouth and vagina) and were obtained from infants weekly until they were discharged. All infants were culture negative for
C. albicans
at birth. Six infants acquired
C. albicans
during their NICU stay. Thirty-four (53%) of 64 mothers were
C. albicans
positive (positive at the mouth,
n
= 26; positive at the vagina,
n
= 18; positive at both sites,
n
= 10) at the time of the infant’s delivery. A total of 49
C. albicans
isolates were analyzed by restriction endonuclease analysis and restriction fragment length polymorphism analysis by using genomic blots hybridized with the CARE-2 probe. Of the mothers positive for
C. albicans
, 3 of 10 were colonized with identical strains at two different body sites, whereas 7 of 10 harbored nonidentical strains at the two different body sites. Four of six infants who acquired
C. albicans
colonization in the NICU had
C. albicans
-positive mothers; specimens from all mother-infant pairs had different restriction endonuclease and CARE-2 hybridization profiles. One
C. albicans
-colonized infant developed candidemia; the colonizing and infecting strains had identical banding patterns. Our study indicates that nonperinatal nosocomial transmission of
C. albicans
is the predominant mode of acquisition by neonates in NICUs at this hospital; mothers may be colonized with multiple strains of
C. albicans
simultaneously; colonizing
C. albicans
strains can cause invasive disease in neonates; and molecular biology-based techniques are necessary to determine the epidemiologic relatedness of maternal and infant
C. albicans
isolates and to facilitate determination of the mode of transmission.
Genotypic and Phenotypic Analysis ofMycoplasma fermentansStrains Isolated from Different Host Tissues
Authors: Campo Laura , Larocque Patrick , La Malfa Tiziana , Blackburn Warren D. , Watson Harold L.
Published: December 2019

A correlation was found between the expression of a specificMycoplasma fermentanssurface antigen (Pra, proteinase-resistant antigen) and the site of isolation of the organism from the infected host. Strains which expressed Pra were most frequently associated with cells of bone marrow origin, and strains which lacked expression of Pra were most commonly isolated from the respiratory tract, genital tract, and arthritic joints, i.e., epithelial cell surfaces. Pra was previously shown to be resistant to degradation by proteinases and was hypothesized to play a protective role at the organism surface and perhaps to influence which host tissue site was colonized by the organism. The methods used for this phenotyping scheme required isolation and growth of the mycoplasma in quantities sufficient for immunoblot analysis using monoclonal antibodies. We wanted to determine a more rapid and less cumbersome technique to supplement this method for determining the Pra phenotype directly in clinical specimens. Here we describe PCR studies to investigate the movement of a previously identifiedM. fermentansinsertion sequence (IS)-like element. These data showed a correlation between a specific IS genotype and the Pra+phenotype. Production of a 160-bp product using a single set of IS-based primers was associated with expression of Pra. The genomic IS location resulting in the 160-bp product was determined by using Southern blot analysis and was found to be a stable insertion site characteristic of genotype I strains. Additional analyses of sequences within and flanking the IS insertion sites revealed another pair of PCR primer sites which resulted in the consistent production of a 450-bp amplicon. The stability of this site was dependent on the absence of the IS-like element between the primer sites. The production of this 450-bp amplicon correlated with the Pra mutant phenotype and was characteristic of genotype II strains. The data showed that the sequence within the IS may be unstable and that reliable genotyping sequences are more easily found in the stable genomic sites which flank the IS element.
Comparison of Methods of Identifying
Helicobacter hepaticus
in B6C3F
1
Mice Used in a Carcinogenesis Bioassay
Authors: Fox James G. , MacGregor Judith A. , Shen Zeli , Li Xiantang , Lewis Robert , Dangler Charles A.
Published: December 2019

In a long-term rodent bioassay evaluating the carcinogenicity of triethanolamine, there was equivocal evidence of carcinogenic activity in male B6C3F
1
mice, based on a marginal increase in the number of hepatocellular adenomas and hepatoblastomas. Interpretation was complicated by the presence of
Helicobacter hepaticus
in selected silver-stained liver sections which also had histological evidence of karyomegaly and oval cell hyperplasia. An increase in numbers of liver tumors, as evidence of carcinogenic activity, was also noted in female mice. However,
H. hepaticus
was not considered a complicating factor, because the livers of the female mice did not have histological features compatible with
H. hepaticus
infection. A retrospective analysis of 51 liver tissue samples from the original carcinogenicity study was conducted to determine the incidence of
H. hepaticus
infection and to evaluate different diagnostic approaches for assessing the presence of
H. hepaticus
in livers lacking characteristic lesions. In an initial evaluation of seven mice with liver tumors, argyrophilic bacteria resembling
H. hepaticus
were observed in liver sections, associated with characteristic liver lesions of hepatocytic karyomegaly and oval cell hyperplasia. Frozen liver tissue was available from four of these mice; all were confirmed to be infected with
H. hepaticus
by culture and PCR. In a larger subsequent analysis using frozen liver tissues from 44 mice without characteristic hepatic lesions,
H. hepaticus
-specific DNA was amplified from the livers of 21 of 44 of the mice (47%), compared to 14 of 44 of the mice (32%) having
H. hepaticus
cultured from their frozen liver tumors. The results of
H. hepaticus
culture and
H. hepaticus
-specific PCR concurred (i.e., both positive and negative results) in 84% of the cases. Microscopic detection of immunofluorescence-labeled or silver-stained bacteria in liver sections was relatively insensitive compared to either culture or PCR detection. This study confirms the widespread prevalence of
H. hepaticus
in mice, its potential to confound experimental results, and the need to include diagnostic testing for
H. hepaticus
in a murine health monitoring program.
Isolation of a Nonpathogenic Strain of
Citrobacter sedlakii
Which Expresses
Escherichia coli
O157 Antigen
Authors: Park C. H. , Martin E. A. , White E. L.
Published: December 2019

A nonpathogenic strain of
Citrobacter sedlakii
which expresses the
Escherichia coli
O157 antigen is described. The discovery of this strain emphasizes the necessity of additional biochemical and/or toxigenicity testing when isolates react with
E. coli
O157 latex reagents.
Recurrent Catheter-Related Infection Caused by a Single Clone of
Mycobacterium chelonae
with Two Colonial Morphotypes
Authors: Hsueh Po-ren , Teng Lee-jene , Yang Pan-chyr , Chen Yu-chi , Ho Shen-wu , Luh Kwen-tay
Published: December 2019

We describe herein a recurrent catheter-related (Port-A-Cath; Smiths Industries Medical Systems [SIMS] Deltec, Inc., St. Paul, Minn.) infection caused by multidrug-resistant
Mycobacterium chelonae
with two colonial morphotypes in a 53-year-old woman with gastric adenocarcinoma. Four isolates recovered from this patient within a 3-month period were found to belong to a single clone on the basis of the isolates’ identical antibiotypes as determined by the E test and their identical random amplified polymorphic DNA patterns.
Rapid Detection of Species of the Opportunistic Yeast
Trichosporon
by PCR
Authors: Sugita Takashi , Nishikawa Akemi , Shinoda Takako
Published: December 2019

Trichosporon
species are opportunistic pathogens, associated with a high mortality rate in immunocompromised patients. Oligonucleotide primers were used to amplify a 170-bp fragment of small-subunit ribosomal DNA of all species in the genus
Trichosporon
by PCR. The primers amplify DNAs of all species in the genus
Trichosporon
, including six causative agents of trichosporonosis. DNAs of other medically important yeasts, such as
Candida albicans
and
Cryptococcus neoformans
, are not amplified by this detection system.
Evaluation of the Abbott LCx Ligase Chain Reaction Assay for Detection of
Chlamydia trachomatis
and
Neisseria gonorrhoeae
in Urine and Genital Swab Specimens from a Sexually Transmitted Disease Clinic Population
Authors: Carroll Karen C. , Aldeen William E. , Morrison Michael , Anderson Roberta , Lee Deborah , Mottice Susan
Published: December 2019

The Abbott LCx ligase chain reaction (LCR) assay for the simultaneous detection of
Chlamydia trachomatis
and
Neisseria gonorrhoeae
was evaluated by using swab and urine specimens from 562 patients.
C. trachomatis
results by LCR were compared to those by the Gen-Probe PACE 2 assay, whereas
N. gonorrhoeae
results by LCR were compared to those by culture. The Gen-Probe and LCR assays were performed according to the manufacturers’ instructions. Gram-negative diplococci growing on modified Thayer-Martin medium were confirmed as
N. gonorrhoeae
by the GonoGen II assay. Supplemental data analysis was performed by major outer membrane protein PCR for
C. trachomatis
and probes for pilin gene detection for
N. gonorrhoeae
. A true-positive result for each pathogen was defined as a positive result for all three or two of three assays. Overall agreement among the six assays was 94.8%.
C. trachomatis
prevalence was 16.2%;
N. gonorrhoeae
prevalence was 5.5%. The overall sensitivity and specificity, respectively, for each test (after supplemental data analysis) were as follows: for
C. trachomatis
, Gen-Probe, 65.9 and 100%; LCR on urine, 90.1 and 100%; LCR on swab specimens, 96.7 and 100%; and for
N. gonorrhoeae
, culture, 80.6 and 100%; LCR on urine, 93.5 and 99.8%; and LCR on swab specimens, 96.8 and 100%. For women, the
N. gonorrhoeae
culture was very insensitive compared to its performance in men (58.3 versus 94.7%, respectively). For
C. trachomatis
, the Gen-Probe assay’s sensitivity was lower for men than for women (62.3 versus 71.1%, respectively). The sensitivity for
C. trachomatis
detection by LCR on urethral and cervical swab specimens was 96.2 and 97.4% for men and women, respectively. For men, swab results were slightly better than urine results for both pathogens (sensitivity for
C. trachomatis
in swab and urine specimens, 96.2 and 92.5%, respectively; sensitivity for
N. gonorrhoeae
in swab and urine specimens, 100 and 94.7%, respectively), while for women, cervical swabs were superior in sensitivity to urine samples for detecting
C. trachomatis
(swab, 97.4%; urine, 81.6%) and equivalent for
N. gonorrhoeae
(swab, 92.3%; urine, 91.6%). The LCx LCR appears to be both sensitive and specific for the detection of
C. trachomatis
and
N. gonorrhoeae
when performed on urine or genital swab samples. Swab samples had better sensitivity than urine samples for the detection of both pathogens.
Antigenic and Genomic Diversity of Human Rotavirus VP4 in Two Consecutive Epidemic Seasons in Mexico
Authors: Padilla-Noriega Luis , Méndez-Toss Martha , Menchaca Griselda , Contreras Juan F. , Romero-Guido Pedro , Puerto Fernando I. , Guiscafré Héctor , Mota Felipe , Herrera Ismael , Cedillo Roberto , Muñoz Onofre , Calva Juan , Guerrero María de Lourdes , Coulson Barbara S. , Greenberg Harry B. , López Susana , Arias Carlos F.
Published: December 2019

In the present investigation we characterized the antigenic diversity of the VP4 and VP7 proteins in 309 and 261 human rotavirus strains isolated during two consecutive epidemic seasons, respectively, in three different regions of Mexico. G3 was found to be the prevalent VP7 serotype during the first year, being superseded by serotype G1 strains during the second season. To antigenically characterize the VP4 protein of the strains isolated, we used five neutralizing monoclonal antibodies (MAbs) which showed specificity for VP4 serotypes P1A, P1B, and P2 in earlier studies. Eight different patterns of reactivity with these MAbs were found, and the prevalence of three of these patterns varied from one season to the next. The P genotype of a subset of 52 samples was determined by PCR. Among the strains characterized as genotype P[4] and P[8] there were three and five different VP4 MAb reactivity patterns, respectively, indicating that the diversity of neutralization epitopes in VP4 is greater than that previously appreciated by the genomic typing methods.
Proliferative Enterocolitis Associated with Dual Infection with Enteropathogenic
Escherichia coli
and
Lawsonia intracellularis
in Rabbits
Authors: Schauer David B. , McCathey Sonya N. , Daft Barbara M. , Jha Sharda S. , Tatterson Lisa E. , Taylor Nancy S. , Fox James G.
Published: December 2019

Both enteropathogenic
Escherichia coli
(EPEC) and an obligate intracellular bacterium, previously referred to as an intracellular
Campylobacter
-like organism and now designated
Lawsonia intracellularis
, have been reported as causes of enterocolitis in rabbits. An outbreak of enterocolitis in a group of rabbits, characterized by an unusually high rate of mortality, was found to be associated with dual infection with EPEC and
L. intracellularis
. The EPEC strain was found to have
eaeA
gene homology but was negative for
afrA
homology. The absence of the
afrA
gene, which encodes the structural subunit for the AF/R1 pilus, indicates that this rabbit EPEC strain is distinct from the prototypic RDEC-1 strain. This finding suggests that rabbit EPEC strains widely reported in Western Europe, which lack AF/R1 pili, are also present in rabbits in the United States. Dual infection with these two pathogens in rabbits has not been previously reported and may have contributed to the unusually high mortality observed in this outbreak.
Evaluation of Silica Gel Packages for Transport of
Neisseria meningitidis
Authors: Popovic Tanja , Kim Chung , Schmink Susanna , Ajello Gloria
Published: December 2019

Eight
Neisseria meningitidis
reference strains, representing six different serogroups, were plated on 57 blood agar plates each. The growth was harvested and stored in silica gel packages at different temperatures for up to 90 days. When held at 4°C, all strains were recovered after 90 days of storage. Strains held at room temperature or alternately at 4°C and room temperature survived for at least 10 and 17 days, respectively.
Non-O157:H7 Stx2-Producing
Escherichia coli
Strains Associated with Sporadic Cases of Hemolytic-Uremic Syndrome in Adults
Authors: Bonnet R. , Souweine B. , Gauthier G. , Rich C. , Livrelli V. , Sirot J. , Joly B. , Forestier C.
Published: December 2019

From August 1996 to May 1997, six verotoxin-producing
Escherichia coli
(VTEC) strains were isolated from stool specimens of adults suffering from hemolytic-uremic syndrome (HUS). All the isolates were
stx
2
positive and belonged to different serotypes: O6:H4, O91:H10, O91:H21, O rough:H16, OX3:H−, and O nontypeable:H−. The enterohemolysin (Ehly)-encoding genes were detected in two isolates, and none of the isolates harbors the intimin (Eae)-encoding gene. These findings suggest that
stx
2
-positive non-O157:H7 VTEC is a major cause of HUS in adults and that several sources of pathogens are responsible for local endemic infections.
Monoclonal Antibody against
Babesia equi
: Characterization and Potential Application of Antigen for Serodiagnosis
Authors: Avarzed Abgaandorjiin , Igarashi Ikuo , De Waal Daniel T. , Kawai Satoru , Oomori Yukio , Inoue Noboru , Maki Yoshiyuki , Omata Yoshitaka , Saito Atsushi , Nagasawa Hideyuki , Toyoda Yutaka , Suzuki Naoyoshi
Published: December 2019

Monoclonal antibody (MAb) BEG3 was produced against
Babesia equi
parasites to define a species-specific antigen for diagnostic use. The MAb reacted with single, paired, and Maltese cross forms of
B. equi
, and no reaction was observed with this MAb on acetone-fixed
Babesia caballi
,
Babesia ovata
, or
Babesia microti
parasites in the indirect immunofluorescent antibody test. Confocal laser and immunoelectron microscopic studies showed that the antigen which was recognized by this MAb was located on the surface of
B. equi
parasites. This MAb recognized a 19-kDa protein of
B. equi
antigen and did not react with
B. caballi
antigen or normal horse erythrocytes in immunoblot analysis. This MAb also significantly inhibited the in vitro growth of the
B. equi
parasite. Preliminary studies using partially purified antigen, which was separated by high-pressure liquid chromatography and recognized by the MAb, suggested that it is a suitable antigen for enzyme-linked immunosorbent assay detection of anti-
B. equi
antibodies in naturally infected horse sera.
Characterization of Glycopeptide-Resistant Enterococci from a Swiss Hospital
Authors: Liassine Nadia , Frei Reno , Jan Isabelle , Auckenthaler Raymond
Published: December 2019

Between August 1994 and September 1996, 28 glycopeptide-resistant enterococci (GRE) were isolated from 8 infected patients and 11 intestinal carriers hospitalized at the University Hospital of Geneva. Identification to the species was made by both phenotypic (API 20 STREP and Rapid ID 32 STREP systems, and Vitek Gram Positive Identification Card) and genotypic methods using a multiplex PCR assay developed also for the determination of the genotype of glycopeptide resistance (
vanA
,
vanB
,
vanC1
, and
vanC2-C3
genes). Fifteen isolates were identified as
Enterococcus faecium
, 8 as
E. gallinarum
, 4 as
E. faecalis
, and 1 as
E. hirae
. All of the phenotypic identification methods failed to differentiate some isolates of
E. gallinarum
from
E. faecium
, or vice versa. Both
vanA
(
n
= 18) and
vanB
(
n
= 4) glycopeptide resistance genotypes were found. For the first time, the
vanB
determinant was found in two isolates of
E. gallinarum
. Two patients were colonized by two different species containing the
vanA
gene and one by two different species containing the
vanB
gene. All
vanA
isolates were highly resistant to both vancomycin and teicoplanin except for three isolates which were susceptible to teicoplanin. Molecular typing by pulsed-field gel electrophoresis showed identical or similar patterns among
E. faecium
isolates with the
vanA
gene in five patients for whom the epidemiological link could not be always elucidated. This study emphasizes the necessity of utilizing both phenotypic and genotypic methods to characterize GRE.
Single-Step Multiplex PCR Assay for Characterization of New World
Leishmania
Complexes
Authors: Harris Eva , Kropp Gerald , Belli Alejandro , Rodriguez Betzabé , Agabian Nina
Published: December 2019

We have developed a PCR assay for one-step differentiation of the three complexes of New World
Leishmania
(
Leishmania braziliensis
,
Leishmania mexicana
, and
Leishmania donovani
). This multiplex assay is targeted to the spliced leader RNA (mini-exon) gene repeats of these organisms and can detect all three complexes simultaneously, generating differently sized products for each complex. The assay is specific to the
Leishmania
genus and does not recognize related kinetoplastid protozoa, such as
Trypanosoma cruzi
,
Trypanosoma brucei
, and
Crithidia fasciculata
. It correctly identified
Leishmania
species with a broad geographic distribution in Central and South America. The sensitivity of the PCR amplification ranged from 1 fg to 10 pg of DNA (0.01 to 100 parasites), depending on the complex detected. Crude extracts of cultured parasites, prepared simply by boiling diluted cultures, served as excellent templates for amplification. Crude preparations of clinical material were also tested. The assay detected
L. braziliensis
in dermal scrapings from cutaneous leishmanial lesions,
Leishmania chagasi
in dermal scrapings of atypical cutaneous leishmaniasis, and
L. mexicana
from lesion aspirates from infected hamsters. We have minimized the material requirements and maximized the simplicity, rapidity, and informative content of this assay to render it suitable for use in laboratories in countries where leishmaniasis is endemic. This assay should be useful for rapid in-country identification of
Leishmania
parasites, particularly where different
Leishmania
complexes are found in the same geographical area.
Novel Method for Processing Respiratory Specimens for Detection of Mycobacteria by Using C
18
-Carboxypropylbetaine: Blinded Study
Authors: Thornton Charles G. , MacLellan Kerry M. , Brink Thomas L. , Lockwood Denise E. , Romagnoli Mark , Turner June , Merz William G. , Schwalbe Richard S. , Moody Marcia , Lue Yvonne , Passen Selvin
Published: December 2019

A novel method for processing respiratory specimens to improve culture and acid-fast staining of mycobacteria is introduced. This new method utilized
N
,
N
-dimethyl-
N
-(
n
-octadecyl)-
N
-(3-carboxypropyl)ammonium inner salt (Chemical Abstract Service no. 78195-27-4), also known as C
18
-carboxypropylbetaine (CB-18). In a blinded, five-center study, CB-18-based processing was compared to the standard method combining NALC and NaOH (NALC/NaOH). A total of 573 respiratory specimens were tested. Individual specimens were split approximately equally; the host institutions processed half of each specimen by the NALC/NaOH method, while the other half was processed with CB-18 at Quest Diagnostics—Baltimore. A total of 106 specimens were culture positive for acid-fast bacilli (AFB). Replacement of the primary decontamination agent with CB-18 caused changes in all diagnostic parameters. Aggregate culture sensitivity improved by approximately 43% (
P
< 0.01), and smear sensitivity improved by approximately 58% (
P
< 0.01). The sensitivity of smear relative to that of
M. tuberculosis
isolates exceeded 93% (
P
< 0.01) when specimens were processed with CB-18. The average times to a positive result were reduced by 7.3 days in liquid culture (
P
< 0.01) and 5.3 days on solid media (
P
< 0.05); however, the CB-18 method had a 20.8% contamination rate in liquid culture versus a rate of approximately 7.5% with NALC/NaOH processing. There were also unusual reductions in liquid culture sensitivity and smear specificity among CB-18-processed specimens. The characteristics of the latter parameters suggested that refinement of the CB-18 processing method should allow further improvements in culture sensitivity. This study showed that the CB-18 method has the potential to improve both smear and culture detection for these important human pathogens.
Low-Level Viremia and Intracellular Expression of Hepatitis B Surface Antigen (HBsAg) in HBsAg Carriers with Concurrent Hepatitis C Virus Infection
Authors: Chu Chia-Ming , Yeh Chau-Ting , Liaw Yun-Fan
Published: December 2019

Assays of hepatitis B virus (HBV) replication and antigen expression in HBV surface antigen (HBsAg) carriers with concurrent hepatitis C or D virus (HCV or HDV) infection revealed that HCV and HDV can suppress HBV replication but that HCV also substantially suppresses HBV surface protein expression. HBsAg carriers with concurrent HCV infection thus have low-level viremia and intracellular HBsAg.
Borna Disease in a Dog with Lethal Meningoencephalitis
Authors: Weissenböck Herbert , Nowotny Norbert , Caplazi Patrick , Kolodziejek Jolanta , Ehrensperger Felix
Published: December 2019

A dog was euthanatized because of progressive neurological signs. Histologically, a nonsuppurative meningoencephalitis was found. By immunohistochemistry, in situ hybridization, and nested PCR procedures, Borna disease virus (BDV) antigen and BDV-specific RNA were demonstrated in brain tissues of the dog. The nucleotide sequence of the PCR product showed 94 to 98% homology to published BDV sequences. This is the first description of Borna disease in a dog.
Experimental Transmission ofEhrlichia equito Horses through Naturally Infected Ticks (Ixodes pacificus) from Northern California
Authors: Reubel Gerhard H. , Kimsey Robert B. , Barlough Jeffrey E. , Madigan John E.
Published: December 2019

We report the experimental transmission ofEhrlichia equifrom naturally infectedIxodes pacificusticks to horses. Three weeks after exposure to ticks, two of three horses developed clinical signs compatible withE. equiinfection, while one horse remained asymptomatic. 16S rRNA gene PCR of blood leukocyte lysates was positive for all horses at various time points; two horses seroconverted. The 16S rRNA gene sequences amplified from tick-exposed horses showed more than 99% homology to corresponding fragments of the 16S rRNA genes ofE. equi,Ehrlichia phagocytophila, and the human granulocytic ehrlichiosis agent.
Clinical Evaluation of the Gen-Probe Amplified Direct Test for Detection of
Mycobacterium tuberculosis
Complex Organisms in Cerebrospinal Fluid
Authors: Lang Anne M. , Feris-Iglesias Jesus , Pena Chabela , Sanchez Jacqueline F. , Stockman Leslie , Rys Paul , Roberts Glenn D. , Henry Nancy K. , Persing David H. , Cockerill Franklin R.
Published: December 2019

Eighty-four cerebrospinal fluid (CSF) samples from different children who presented with signs and symptoms of meningitis were evaluated for the presence of
Mycobacterium tuberculosis
complex organisms by the Gen-Probe Amplified
Mycobacterium tuberculosis
Direct Test (MTD; Gen-Probe, San Diego, Calif.). All CSF samples had negative acid-fast smears by the Ziehl-Neelsen staining method.
M. tuberculosis
was recovered from five samples.
M. tuberculosis
did not grow from 19 additional samples, but the samples were from patients who fulfilled specific clinical and laboratory criteria for probable tuberculous meningitis (TBM). The remaining samples (
n
= 60) were from patients with other infections or noninfectious causes of meningitis. The results of the MTD were interpreted as positive or negative on the basis of recommended cutoff values for respiratory specimens. These results were interpreted as true or false positives or true or false negatives on the basis of the results of
M. tuberculosis
culture or whether the patient fulfilled criteria for probable TBM. The Gen-Probe MTD was 33% sensitive and 100% specific for detecting
M. tuberculosis
complex organisms in these 84 CSF samples. If the cutoff values for positive results were decreased for the MTD (≥11,000 versus ≥30,000 relative light units), the sensitivity increased to 83% and the specificity remained 100%. These results for the MTD are encouraging considering that TBM is a highly fatal disease and difficult to diagnose by conventional laboratory techniques.
Etiological Study of Diarrheal Patients in Vientiane, Lao People’s Democratic Republic
Authors: Yamashiro Tetsu , Nakasone Noboru , Higa Naomi , Iwanaga Masaaki , Insisiengmay Sithat , Phounane Traykhouane , Munnalath Khampheuy , Sithivong Noikaseumsy , Sisavath Lay , Phanthauamath Boonang , Chomlasak Khampheng , Sisulath Phonsamay , Vongsanith Praseunthong
Published: December 2019

The etiological agents of diarrhea in Vientiane, Lao People’s Democratic Republic (Lao PDR), were studied in the period from October 1996 to August 1997. A total of 880 patients with diarrhea visiting medical facilities were examined for
Shigella
,
Salmonella
, diarrheagenic
Escherichia coli
,
Vibrio
,
Aeromonas
,
Campylobacter
, and rotavirus.
Shigella
spp., heat-stable enterotoxin (ST)-producing
E. coli
, and serogroup-based enteropathogenic
E. coli
were found to be the main organisms causing diarrhea in Vientiane, with frequencies of 16.8% (148 of 880), 17.2% (111 of 645), and 11.0% (97 of 880), respectively. Relatively low incidences were observed in the cases of
Salmonella
spp., (0.6%; 5 of 880),
Campylobacter
spp. (4.4%; 39 of 880), and rotavirus (6.1%; 9 of 148), and no isolates of
V. cholerae
O1 or O139 or
Aeromonas
were recovered. An analysis of the incidences of enteropathogens with respect to age and seasonal variations demonstrated that the frequencies of isolation of
Shigella
spp. and heat-labile enterotoxin-producing
E. coli
were significantly higher in those aged 1 to 5 years than in those younger than 1 year of age and those older than 5 years of age (
P
< 0.0001 and
P
< 0.05, respectively) and that the frequencies of isolation of
Shigella
spp. and ST-producing
E. coli
were significantly higher in the rainy season than in the dry season (
P
< 0.005 and
P
< 0.001, respectively). Almost all strains of
Shigella
spp. tested were resistant to ampicillin, tetracycline, and erythromycin and were susceptible to cefdinir and ofloxacin. This is the first intensive and longitudinal study to define the etiologic agents of diarrheal diseases in Lao PDR.
Isolation ofKlebsiella planticolafrom Newborns in a Neonatal Ward
Authors: Podschun R. , Acktun H. , Okpara J. , Linderkamp O. , Ullmann U. , Borneff-Lipp M.
Published: December 2019

This is the first report on the isolation ofKlebsiella planticolafrom neonates. Over a period of 1 year, oropharyngeal and rectal swab specimens from 131 newborns on a neonatal ward were monitored forKlebsiellaspp. Thirteen strains ofK. planticolacould be isolated, and these represented 9% of allKlebsiellaspp. found. Capsule type K27 predominated, followed by capsule type K68. Our findings suggest a significant rate of colonization byK. planticolaamong neonates.