bluuebunny/crossref_metadata_2025 huggingface dataset:
Controlled Comparative Evaluation of BacT/Alert FAN and ESP 80A Aerobic Media as Means for Detecting Bacteremia and Fungemia
Authors: Doern Gary V. , Barton Ann , Rao Sudah
Published: December 2019

During a one-year period, a total of 6,305 blood cultures were processed in a tertiary-care teaching hospital; 6 to 12 ml of blood was inoculated into both a BacT/Alert Fan aerobic bottle and an ESP 80A aerobic bottle. The FAN aerobic bottle contains an antimicrobial-absorbing material; the 80A aerobic bottle does not. Bottles were processed on their respective continuous-monitoring blood culture instruments for up to five days of incubation. Four hundred thirty-three cultures (6.9%) representing 301 septic episodes in 235 different patients yielded 490 bacteria or yeasts thought to be clinically significant. Two hundred seventy-five of the 433 presumed clinically significant positive cultures (63.5%) representing 195 septic episodes and yielding 301 isolates were positive in both FAN and 80A bottles. One hundred nine significant positive cultures (25.2%) (i.e., cultures positive with an organism judged to be of probable clinical significance) from 70 septic episodes yielded 126 isolates only in FAN bottles. Conversely, the 80A bottle was exclusively positive in 49 instances (11.3%), representing 36 septic episodes and yielding 63 isolates. The higher rates of significant positive blood cultures, numbers of septic episodes documented, and numbers of isolates recovered in FAN bottles versus 80A bottles were all statistically significant (
P
< 0.05). Enhanced rates of detection of presumed clinically significant isolates in FAN bottles were largely accounted for by
Staphylococcus aureus
, members of the
Enterobacteriaceae
, and non-
Pseudomonas aeruginosa
miscellaneous gram-negative bacilli from patients receiving antimicrobial therapy at the time blood cultures were obtained. Enhanced recovery of one organism group, the β-hemolytic streptococci, occurred in 80A. With one exception, detection times were essentially equivalent in the two systems. The single exception pertained to streptococci and enterococci, which were recovered significantly faster in 80A bottles. Three hundred thirty-eight of the 6,305 blood cultures evaluated in this study (5.4%) were judged likely to be contaminated. The percentages of probable contaminated cultures were as follows: 26.6% FAN and 80A; 42.3% FAN only; 31.1% 80A only (
P
< 0.05). Finally, the instrument false-positive rates for the two systems were 0.7% with FAN and 3.0% with 80A (
P
< 0.05). We conclude that while contamination rates were slightly higher with FAN than with 80A, use of FAN aerobic bottles in conjunction with the BacT/Alert system will yield significantly higher numbers of clinically significant blood culture isolates than 80A bottles and the ESP system. Furthermore, this enhanced detection is most conspicuous in patients receiving antimicrobial therapy at the time blood cultures are performed, probably due to the presence of an antimicrobial-absorbing material in FAN aerobic bottles.
Dynamics of Antigenemia and Coproantigens during a Human
Fasciola hepatica
Outbreak
Authors: Espino Ana M. , Díaz Ailén , Pérez Antonio , Finlay Carlos M.
Published: December 2019

In the present study the dynamics of antigenemia and coproantigens were studied in patients with
Fasciola hepatica
infection during an outbreak occurring in La Palma, Pinar del Rı́o, in the West Province of Cuba. Stool and serum samples were collected from 67 patients and 40 healthy subjects. Stool samples were studied by a simple gravity sedimentation technique and an ES78 sandwich enzyme-linked immunosorbent assay (ELISA) for observation of eggs and detection of parasite coproantigens, respectively. Serum samples were also studied by the ES78 sandwich ELISA and an indirect ELISA to detect circulating antigens and antibodies, respectively. At the beginning of the study, 8 of 67 patients had patent infections and 59 had prepatent infections, which was determined by the recent consumption of lettuce contaminated with metacercariae of
F. hepatica
, the presence of clinical symptoms, and the absence of
Fasciola
eggs in their stools. Patients with prepatent infections were monitored by all techniques until patency. Circulating antigens were not detected in patients with patent infections. However, coproantigens were clearly detected in all patients with patent infections. On the other hand, 28.8% of patients with prepatent infections tested positive for circulating antigens and 81.4% tested positive for coproantigens in the first stool sample studied. Only two other coproantigen determinations were necessary to diagnose 93.2% of the patients. While circulating antigen levels diminished in all patients during the infection, coproantigen levels increased. The present study demonstrates that the ES78 sandwich ELISA is a better tool than parasitological examination for diagnosis of active early infection, since by the combination of the circulating-antigen detection assay and the coproantigen detection assay 91% of patients were able to be diagnosed at the beginning of the study. In contrast, a coprologic analysis repeated over several weeks was necessary to diagnose 100% of the patients.
Nasal Granuloma Caused byScedosporium apiospermumin a Dog
Authors: Cabañes F. J. , Roura X. , García F. , Domingo M. , Abarca M. L. , Pastor J.
Published: December 2019

A 10-month-old male American Staffordshire terrier was presented to the Autonomous University of Barcelona Veterinary Teaching Hospital because of a 6-month history of a mucopurulent bilateral nasal discharge. The dog had not responded to antibiotics. A follow-up X ray revealed a mixed pattern of osteolysis and increased radiodensity confined to the nasal cavity. Histologic sections of the biopsy specimens revealed the presence of granules containing numerous septate hyphae that were hyaline to pale brown and smooth, one-celled, subspherical-to-elongate conidia that were hyaline to brownish green, and bacteria. Cultures yielded numerous colonies belonging toScedosporium apiospermum. Susceptibility tests were performed on the isolated strain. The isolate was sensitive to ketoconazole, intermediate to clotrimazole, and resistant to amphotericin B, 5-fluorocytosine, fluconazole, and itraconazole. The dog was treated with oral ketoconazole. During the treatment a general improvement in the lesions was observed. To our knowledge,S. apiospermumhas not been implicated previously as an etiologic agent of nasal disease in dogs. This report provides its first description as such.
Rapid Identification of up to Three
Candida
Species in a Single Reaction Tube by a 5′ Exonuclease Assay Using Fluorescent DNA Probes
Authors: Shin Jong Hee , Nolte Frederick S. , Holloway Brian P. , Morrison Christine J.
Published: December 2019

We used fungus-specific PCR primers and species-specific DNA probes to detect up to three
Candida
species in a single reaction tube by exploiting the 5′ to 3′ exonuclease activity of
Taq
DNA polymerase. Probes to the internal transcribed spacer region of the rRNA gene were labeled at the 5′ end with one of three fluorescent reporter dyes, 6-carboxy-fluorescein (FAM), tetrachloro-6-carboxy-fluorescein (TET), or hexachloro-6-carboxy-fluorescein (HEX), and at the 3′ end with a quencher dye, 6-carboxy-tetramethyl-rhodamine. During PCR amplification, each reporter dye emits a characteristic wavelength as it is cleaved from its specific target DNA and from the quencher dye. Therefore, signals from up to three probes can be detected simultaneously during the PCR assay. Six probes were designed for use in this study: CA-FAM, CT-TET, and CP-HEX were added to one tube to simultaneously detect the typically fluconazole-sensitive species
C. albicans
,
C. tropicalis
, and
C. parapsilosis
, respectively. CG-FAM and CK-TET were added to a second tube to simultaneously detect the typically more innately fluconazole-resistant species
C. glabrata
and
C. krusei
, respectively. All-CAN-TET, a
Candida
genus probe, was added to a third tube to detect DNAs from all
Candida
species tested. DNAs recovered from 61 blood culture bottles, including 23 positive for
C. albicans
, 18 positive for
C. glabrata
, 6 positive for
C. tropicalis
, 6 positive for
C. krusei
, 5 positive for
C. parapsilosis
, and 3 positive for mixed fungemias, were tested. Control samples included those from blood culture bottles with no growth (
n
= 10) or from patients with confirmed bacteremia (
n
= 10). Probes detected and correctly identified the organisms in 58 of 61 specimens (95.1%) and gave no false-positive results. This method is simple and rapid and does not require post-PCR hybridization and incubation steps. It is sensitive and specific for the detection and identification of
Candida
species from blood culture bottles, including those containing mixtures of
Candida
species, and should facilitate an earlier specific diagnosis, leading to more appropriately targeted antifungal drug therapy.
Healthy Cats Are Commonly Colonized with “Helicobacter heilmannii” That Is Associated with Minimal Gastritis
Authors: Norris C. R. , Marks S. L. , Eaton K. A. , Torabian S. Z. , Munn R. J. , Solnick J. V.
Published: December 2019

GastricHelicobacterinfection in healthy pet cats is not well characterized. We performed endoscopy with gastric biopsy on 15 healthy pet cats that were rigorously screened to exclude underlying or concurrent diseases that might affectHelicobactercolonization. Gastric mucosa biopsy specimens were examined by histology, culture, and PCR for the presence ofHelicobacterinfection and by histology for the presence of gastritis. Of 15 cats, all but 1 had gastricHelicobacter-like organisms (GHLOs) on examination by light microscopy, and in the one histologically negative cat, GHLOs were detected by PCR. Gastric inflammation was mild or was absent for all cats. NoHelicobacterspecies were identified by culture. Analysis of the 16S rRNA sequence fromHelicobacterstrains from 10 cats showed that all bacteria were closely related toHelicobacter felis, although there was heterogeneity among the sequences. These results suggest that the gastric mucosa of healthy pet cats is commonly colonized with an uncultivatedHelicobacterthat is closely related toH. felis, is associated with little or no gastritis, and shows heterogeneity in its 16S rRNA sequence. The epithet “Helicobacter heilmannii” continues to be an appropriate working designation for these bacteria.
Metarrhizium anisopliae
as a Cause of Sinusitis in Immunocompetent Hosts
Authors: Revankar Sanjay G. , Sutton Deanna A. , Sanche Stephen E. , Rao Jyothi , Zervos Marcus , Dashti Farnaz , Rinaldi Michael G.
Published: December 2019

Metarrhizium anisopliae
is a common pathogen of insects and has even been used to control insect populations. It is rarely isolated from human or animal sources, but recently, there have been three reported cases of disease, two in humans and one in a cat. We present our experience with five isolates from human sources, including two that were the apparent causes of two cases of sinusitis in immunocompetent hosts. The first patient was a 36-year-old male with frontal and ethmoid sinusitis, and the second was a 79-year-old female with chronic sinusitis. Both patients underwent surgery, and pathology of the surgical specimens revealed branching hyphae. Cultures grew only
Metarrhizium
species. Neither patient received antifungal therapy, and both did well postoperatively. The other three isolates were cultured from bronchoalveolar lavage specimens but were not felt to be clinically significant. Antifungal susceptibility testing using the National Committee for Clinical Laboratory Standards macrobroth method revealed that all isolates were resistant to amphotericin B, 5-flucytosine, and fluconazole. Itraconazole and newer azole compounds were more active.
Metarrhizium
species may cause disease in humans, even those without evidence of immunosuppression, and are apparently highly resistant to amphotericin B in vitro.
Comparison of Two PCRs for Detection of
Mycobacterium ulcerans
Authors: Guimaraes-Peres A. , Portaels F. , de Rijk P. , Fissette K. , Pattyn S. R. , van Vooren J.-P. , Fonteyne P.-A.
Published: December 2019

Two nested PCRs for the detection of
Mycobacterium ulcerans
were compared by using a collection of 65 clinical specimens. The first method amplifies the gene coding for 16S rRNA, and the second method amplifies a repetitive DNA sequence. The sensitivities of bacterioscopy, culture, 16S rRNA gene PCR, and repetitive-sequence PCR were 29, 34, 80, and 85%, respectively. Compared to the 16S rRNA gene PCR, the repetitive-sequence PCR was faster, easier to perform, and less expensive.
Determination of Trimethoprim-Sulfamethoxazole Resistance in
Streptococcus pneumoniae
by Using the E Test with Mueller-Hinton Agar Supplemented with Sheep or Horse Blood May Be Unreliable
Authors: Lovgren M. , Dell’Acqua L. , Palacio R. , Echániz-Aviles G. , Soto-Noguerón A. , Castañeda E. , Agudelo C. I. , Heitmann I. , Brandileone M. C. , Zanella R. C. , Rossi A. , Pace J. , Talbot J. A. ,   The Pneumococcal Study Group
Published: December 2019

An international, multicenter study compared trimethoprim-sulfamethoxazole MICs for 743
Streptococcus pneumoniae
isolates (107 to 244 isolates per country) by E test, using Mueller-Hinton agar supplemented with 5% defibrinated horse blood or 5% defibrinated sheep blood, with MICs determined by the National Committee for Clinical Laboratory Standards broth microdilution reference method. Agreement within 1 log
2
dilution and minor error rates were 69.3 and 15.5%, respectively, on sheep blood-supplemented agar and 76.9 and 13.6%, respectively, with horse blood as the supplement. Significant interlaboratory variability was observed. E test may not be a reliable method for determining the resistance of pneumococci to trimethoprim-sulfamethoxazole.
Dissemination of High-Level Penicillin-, Extended-Spectrum Cephalosporin-, and Erythromycin-Resistant
Streptococcus pneumoniae
Clones in Taiwan
Authors: Hsueh Po-Ren , Teng Lee-Jene , Lee Li-Na , Yang Pan-Chyr , Ho Shen-Wu , Luh Kwen-Tay
Published: December 2019

Sixty-seven clinical isolates of
Streptococcus pneumoniae
(40 of serotype 23F, 19 of serotype 19F, and 8 of serotype 6B) with decreased susceptibilities to penicillin and erythromycin were characterized by antimicrobial susceptibility patterns; DNA restriction endonuclease cleavage profiles of the penicillin-binding protein genes
pbp1a
,
pbp2b
, and
pbp2x
; random amplified polymorphic DNA (RAPD) patterns generated by arbitrarily primed PCR; and chromosomal macrorestriction profiles based on pulsed-field gel electrophoresis. A total of 22 clones (identical or closely related pulsotypes and identical RAPD patterns) were identified; 14 clones of 23F, 6 of 19F, and 2 of 6B. Three 23F clones (26 isolates) and one 19F clone (9 isolates) expressed high-level resistance to penicillin, cefotaxime, and erythromycin (MICs ≥ 256 μg/ml). These data strongly suggest that multiple high-level penicillin-, extended-spectrum cephalosporin-, and macrolide-resistant clones of
S. pneumoniae
have been disseminated in Taiwan.
Molecular Evidence for Transmission of Human T-Lymphotropic Virus Type II Infection by a Human Bite
Authors: Bolton W. V. , Davis A. R. , Ge Y. C. , Dwyer D. E. , Kenrick K. G. , Cunningham A. L. , Saksena N. K.
Published: December 2019

Investigation of a human T-lymphotropic virus type II (HTLV-II) infection in a female Australian blood donor identified a human bite as the likely mode of transmission, confirmed by nucleotide sequencing of the proviral
tax/rex
from both donor and contact. We believe this to be the first report of the transmission of an HTLV by a human bite.
DNA Fingerprinting of Single Colonies of
Helicobacter pylori
from Gastric Cancer Patients Suggests Infection with a Single Predominant Strain
Authors: Miehlke Stephan , Thomas Rachel , Guiterrez Oscar , Graham David Y. , Go Mae F.
Published: December 2019

In each of six gastric cancer patients, repetitive extragenic palindromic PCR DNA fingerprints of 18 single colonies of
Helicobacter pylori
from the gastric antrum, corpus, and cardia were identical and matched that of the parental isolate. In three additional gastric cancer patients, 17 of 18 single-colony DNA fingerprints were identical to each other and to the DNA fingerprint of the corresponding parental isolate.
Optimal Activation of Isopsoralen To Prevent Amplicon Carryover
Authors: Fahle Gary A. , Gill Vee J. , Fischer Steven H.
Published: December 2019

We compared the efficiencies of activation of the photochemical isopsoralen compound 10 and its resulting amplicon neutralizations under conditions with a UV transilluminator box at room temperature (RT) and a HRI-300 UV photothermal reaction chamber at RT and at 5°C. Our data suggest that use of the HRI-300 reaction chamber at 5°C results in a statistically significantly higher degree of amplicon neutralization.
Increasing Incidence and Comparison of Nalidixic Acid-Resistant
Salmonella enterica
subsp.
enterica
Serotype Typhimurium Isolates from Humans and Animals
Authors: Heurtin-Le Corre Christine , Donnio Pierre-Yves , Perrin Monique , Travert Marie-France , Avril Jean-Loup
Published: December 2019

We determined the resistance to quinolone of 309
Salmonella enterica
subsp.
enterica
serotype Typhimurium strains isolated from humans and animals (cattle, pigs, or poultry) in 1995 or 1996. Nalidixic acid resistance increased from 8.5% in 1995 to 18.6% in 1996. The highest resistance levels correlated with a mutation at Ser-83 (or Asp-82). All strains remained ciprofloxacin susceptible. Human and animal isolates were compared by pulsed-field gel electrophoresis, and the banding patterns of the human isolates most closely matched those of the bovine isolates.
Diagnosis of Human Ehrlichiosis by PCR Assay of Acute-Phase Serum
Authors: Comer James A. , Nicholson William L. , Sumner John W. , Olson James G. , Childs James E.
Published: December 2019

A PCR assay of 43 acute-phase serum samples was evaluated as a method for early detection of human granulocytic ehrlichiosis (HGE) and determination of etiology when serologic testing is inconclusive. Sequence-confirmed products of the HGE agent were amplified from three individuals residing or having exposure history in Minnesota or Wisconsin, and similarly confirmed products fromEhrlichia chaffeensiswere amplified from three individuals from Florida or Maryland. Etiology, as determined by PCR and serology, was the same whenever there was a fourfold difference between the maximum titers of antibodies to both antigens, indicating that presumptive determination of etiology may be based on fourfold differences in titers. PCR testing determined thatE. chaffeensiswas the etiologic agent for one individual who had similar titers of antibodies to both agents. PCR assay of acute-phase serum in the absence of whole blood specimens may be a useful method for early detection of human ehrlichiosis and determination of etiology when serologic testing is inconclusive.
Heterogeneously Vancomycin-Resistant
Staphylococcus epidermidis
Strain Causing Recurrent Peritonitis in a Dialysis Patient during Vancomycin Therapy
Authors: Sieradzki Krzysztof , Roberts Richard B. , Serur David , Hargrave Judie , Tomasz Alexander
Published: December 2019

Methicillin-resistant
Staphylococcus epidermidis
(MRSE) was recovered over a 2-month period from the dialysis fluid of a peritoneal dialysis (PD) patient who experienced recurrent episodes of peritonitis during therapeutic and prophylactic use of vancomycin. Characterization of five consecutive MRSE isolates by molecular and microbiological methods showed that they were representatives of a single strain, had reduced susceptibility to vancomycin, did not react with DNA probes specific for the enterococcal
vanA
or
vanB
gene, and showed characteristics reminiscent of the properties of a recently described vancomycin-resistant laboratory mutant of
Staphylococcus aureus
. Cultures of these MRSE isolates were heterogeneous: they contained—with a frequency of 10
−4
to 10
−5
—bacteria for which vancomycin MICs were high (25 to 50 μg/ml) which could easily be selected to “take over” the cultures by using vancomycin selection in the laboratory. In contrast, the five consecutive MRSE isolates recovered from the PD patient during virtually continuous vancomycin therapy showed no indication for a similar enrichment of more resistant subpopulations, suggesting the existence of an “occult” infection site in the patient (presumably at the catheter exit site) which was not accessible to the antibiotic.
Mycobacterium
Species Identification and Rifampin Resistance Testing with High-Density DNA Probe Arrays
Authors: Troesch A. , Nguyen H. , Miyada C. G. , Desvarenne S. , Gingeras T. R. , Kaplan P. M. , Cros P. , Mabilat C.
Published: December 2019

Species identification within the genus
Mycobacterium
and subsequent antibiotic susceptibility testing still rely on time-consuming, culture-based methods. Despite the recent development of DNA probes, which greatly reduce assay time, there is a need for a single platform assay capable of answering the multitude of diagnostic questions associated with this genus. We describe the use of a DNA probe array based on two sequence databases: one for the species identification of mycobacteria (82 unique 16S rRNA sequences corresponding to 54 phenotypical species) and the other for detecting
Mycobacterium tuberculosis
rifampin resistance (
rpoB
alleles). Species identification or rifampin resistance was determined by hybridizing fluorescently labeled, amplified genetic material generated from bacterial colonies to the array. Seventy mycobacterial isolates from 27 different species and 15 rifampin-resistant
M. tuberculosis
strains were tested. A total of 26 of 27 species were correctly identified as well as all of the
rpoB
mutants. This parallel testing format opens new perspectives in terms of patient management for bacterial diseases by allowing a number of genetic tests to be simultaneously run.
Clinical Spectrum of Infections Due to the Newly Described
Actinomyces
Species
A. turicensis
,
A. radingae
, and
A. europaeus
Authors: Sabbe Luc J. M. , Van De Merwe Dick , Schouls Leo , Bergmans Anneke , Vaneechoutte Mario , Vandamme Peter
Published: December 2019

Over a 7-year period, we isolated 294
Actinomyces
-like organisms (ALOs) which were not clearly identifiable. Using well-defined probes coding for sequences specific for recently described
Actinomyces
species (
A. turicensis
,
A. radingae
, and
A. europaeus
), we were able to identify 128 strains. The majority belonged to the
A. turicensis
species.
A. radingae
was found only in patients with skin-related pathologies.
A. europaeus
was also detected in patients with urinary tract infections. The main sources of
A. turicensis
were genital infections, followed by skin-related and urinary tract infections. Additional clinical pictures were appendicitis, cholecystitis, ear, nose, and throat infections, and bacteremia. In a small number of patients these ALOs were found as the only pathogen. Strains of the three species were tested by two widely used biochemical identification methods.
A. turicensis
was easily identifiable by both these methods. We conclude that these ALOs are not infrequent pathogens and are found in a wide range of human infections. At least
A. turicensis
is easily identifiable by clinical diagnostic laboratories.
Typing and Characterization of Mechanisms of Resistance of
Shigella
spp. Isolated from Feces of Children under 5 Years of Age from Ifakara, Tanzania
Authors: Navia Margarita M. , Capitano Liliana , Ruiz Joaquin , Vargas Martha , Urassa Honorati , Schellemberg David , Gascon Joaquim , Vila Jordi
Published: December 2019

Eighty-six strains of
Shigella
spp. were isolated during the dry season from stool samples of children under 5 years of age in Ifakara, Tanzania. The epidemiological relationship as well as the antimicrobial susceptibility and mechanisms of resistance to ampicillin, chloramphenicol, and co-trimoxazole were investigated. Four different epidemiological tools, pulsed-field gel electrophoresis (PFGE), repetitive extragenic palindromic (REP)-PCR, plasmid analysis, and antibiogram, were compared for typing
Shigella
strains. Seventy-eight (90%) strains were
Shigella flexneri
and were distributed into four groups, by either PFGE or REP-PCR, with 51, 17, 7, and 3 strains. The four strains of
Shigella dysenteriae
belonged to the same group, and the four strains of
Shigella sonnei
were distributed in two groups with three and one strain each. Plasmid analysis showed a high level of heterogeneity among strains belonging to the same PFGE group, while the antibiogram was less discriminative. REP-PCR provided an alternative, rapid, powerful genotyping method for
Shigella
spp. Overall, antimicrobial susceptibility testing showed a high level of resistance to ampicillin (81.8%), chloramphenicol (72.7%), tetracycline (96.9%), and co-trimoxazole (87.9%). Ampicillin resistance was related to an integron-borne OXA-1-type β-lactamase in 85.1% of the cases and to a TEM-1-type β-lactamase in the remaining 14.8%. Resistance to co-trimoxazole was due to the presence of a
dhfr Ia
gene in all groups except one of
S. flexneri
, where a
dhfr VII
gene was found within an integron. Chloramphenicol resistance was associated in every case with positive chloramphenicol acetyltransferase activity. All strains were susceptible to nalidixic acid, ciprofloxacin, ceftazidime, cefotaxime, and cefoxitin. Therefore, these antimicrobial agents may be good alternatives for the treatment of diarrhea caused by
Shigella
in Tanzania.
Autopsy-Controlled Prospective Evaluation of Serial Screening for Circulating Galactomannan by a Sandwich Enzyme-Linked Immunosorbent Assay for Hematological Patients at Risk for Invasive Aspergillosis
Authors: Maertens Johan , Verhaegen Jan , Demuynck Hilde , Brock Penelope , Verhoef Gregor , Vandenberghe Peter , Van Eldere Johan , Verbist Ludo , Boogaerts Marc
Published: December 2019

Efforts to improve the diagnosis of invasive aspergillosis (IA) have been directed towards the detection of fungal antigens, including galactomannan (GM). However, previous evaluations of GM detection have been hampered by a lack of proven cases of IA and by a nonserial study design. This prospective study assessed the diagnostic value of serial screening for circulating GM by using a recently developed sandwich enzyme-linked immunosorbent assay (ELISA) for prolonged-neutropenic and/or steroid-treated patients with hematological disorders. Serum GM levels were monitored twice weekly for 186 consecutive patients at increased risk for IA. The patients were stratified according to the likelihood of IA (proven, probable, possible, and no evidence of IA) by using stringent criteria. Proven IA was defined by characteristic histopathological findings together with a positive culture for
Aspergillus
species. Autopsy and culture from autopsy specimens was used to verify both positive and negative test results. A total of 2,172 serum samples were tested from 243 episodes (mean, 9 samples/episode). Based on the analysis of 71 patients with confirmed disease status (culture and histology), the sensitivity and specificity of serial GM monitoring were 92.6 and 95.4%, respectively. The positive predictive value was almost 93%, the negative predictive value was 95%, and the efficacy was 94%. False-positive reactions occurred at a rate of nearly 8%, although this figure might have been overestimated. Less than 1% of all tested sera were considered inconclusive. In more than half of the cases, antigenemia was detected before clinical suspicion of IA (median, 6 days before). Serial determination of serum GM by the sandwich ELISA technique is a sensitive tool for the diagnosis of IA in hematological patients at risk. This approach may substantially influence clinical management with regard to preemptive and empirical antifungal therapy.
Isolation ofHelicobacter canisfrom a Colony of Bengal Cats with Endemic Diarrhea
Authors: Foley Janet E. , Marks Stanley L. , Munson Linda , Melli Ann , Dewhirst Floyd E. , Yu Shilu , Shen Zeli , Fox James G.
Published: December 2019

On the basis of biochemical, phenotypic, and 16S rRNA analyses,Helicobacter caniswas isolated from Bengal cats with and without chronic diarrhea. Because the cats were coinfected with other potential pathogens, includingCampylobacter helveticus, and becauseH. caniswas isolated from nondiarrheic cats, the causal role ofH. canisin producing the diarrhea could not be proven. Histologically, the colons of the four affected cats were characterized by mild to moderate neutrophilic, plasmacytic, and histocytic infiltrates in the lamina propria. Rare crypt abscesses were also noted for three cats but were a more prominent feature of the colonic lesions noted for the fourth cat. This is the first observation ofH. canisin cats and raises the possibility thatH. canis, likeH. hepaticusandH. bilisin mice, can cause inflammation of the colon, particularly in hosts with immune dysregulation. Further studies are needed to determine the importance ofH. canisas a primary enteric pathogen in cats and the role of cats in the possible zoonotic spread ofH. canisto humans.
Dusky-Footed Wood Rats (Neotoma fuscipes) as Reservoirs of Granulocytic Ehrlichiae (Rickettsiales:Ehrlichieae) in Northern California
Authors: Nicholson William L. , Castro Martin B. , Kramer Vicki L. , Sumner John W. , Childs James E.
Published: December 2019

Dusky-footed wood rats (Neotoma fuscipes) andPeromyscussp. mice (P. maniculatusandP. truei) were collected from one site in Placer County, one site in Santa Cruz County, and two sites in Sonoma County in northern California. Serum or plasma samples from 260 rodents were tested for antibodies to the agent of human granulocytic ehrlichiosis. Of these, samples from 25 wood rats (34% of those tested) and 10 (8%)Peromyscussp. mice were found to be seropositive, but only those from one site. PCR assays targeting thegroESLheat shock operon were conducted on all seropositive specimens and a subset of seronegative blood specimens. Ehrlichial DNA was identified in 17 (68%) of the 25 seropositive wood rat blood samples and in 1 of the 10 (10%)Peromyscussp. specimens. None of 40 seronegative blood samples was PCR positive. Both seropositive and PCR-positive animals were collected during each trapping period. One male tick out of 84Ixodes pacificusadults collected was PCR positive; samples ofDermacentor occidentalisnymphs and adults were negative. Nucleotide sequences of amplicons from three wood rat blood specimens and from the single PCR-positive tick differed by one and two bases, respectively, from a sequence previously obtained fromEhrlichia equi. At one site in Sonoma County, wood rats had a concurrent high prevalence of seropositivity and PCR positivity, while other sigmodontine rodents collected at the site were only occasionally infected. We suggest that dusky-footed wood rats serve as reservoirs of granulocytic ehrlichial agents in certain areas of northern California. The tick species involved in the transmission of granulocytic ehrlichiae among wood rats remains unknown.
Detection of
Helicobacter pylori
Antibodies in a Pediatric Population: Comparison of Three Commercially Available Serological Tests and One In-House Enzyme Immunoassay
Authors: Sunnerstam Bengt , Kjerstadius Torbjörn , Jansson Lillemor , Giesecke Johan , Bergström Mats , Ejderhamn Jan
Published: December 2019

A serum immunoglobulin G enzyme immunoassay (EIA) for
Helicobacter pylori
antibodies already in use in adults was evaluated with 99 pediatric serum samples to determine its usefulness for the study of
H. pylori
disease in children. The reference method used was either the
13
C-urea breath test or a biopsy culture of gastric mucosa. In children, an EIA cutoff of 0.35 absorbancy unit yielded sensitivity, specificity, and positive and negative predictive values of 93, 97, 93, and 97%, respectively. The cutoff recommended when this EIA was published for use in adults was 0.70 absorbancy unit (H. Gnarpe, P. Unge, C. Blomqvist, and S. Mäkitalo, APMIS 96:128–132, 1988). Another subset of 169 serum samples taken from children was analyzed by four serological tests in order to compare the performance of the in-house EIA with the Pyloriset, HM-CAP, and Helico-G kits. For the 169 samples, 10 (5.9%) false-positives and no false-negatives occurred with the Helico-G, 3 (1.8%) false-positives and no false-negatives occurred with the Pyloriset, and 3 (1.8%) false-positives and 1 (0.6%) false-negative occurred with the HM-CAP. For the 169 samples, 1 (0.6%) false-positive and no false-negatives occurred with the in-house EIA. Serological detection of
H. pylori
antibodies with our EIA seems to be valuable in diagnosing
H. pylori
infection in children, but only if a lowered, specific pediatric cutoff is established. The commercial kits, particularly the Helico-G, seem to overdiagnose pediatric
H. pylori
infection. A positive serological test for
H. pylori
infection, particularly for children, needs to be confirmed by a reference method because of the possibility of spontaneous eradication of infection, with a lingering serological response.
Quantitation of Ergosterol Content: Novel Method for Determination of Fluconazole Susceptibility of
Candida albicans
Authors: Arthington-Skaggs Beth A. , Jradi Hoda , Desai Tejal , Morrison Christine J.
Published: December 2019

MIC end points for the most commonly prescribed azole antifungal drug, fluconazole, can be difficult to determine because its fungistatic nature can lead to excessive “trailing” of growth during susceptibility testing by National Committee for Clinical Laboratory Standards broth macrodilution and microdilution methods. To overcome this ambiguity, and because fluconazole acts by inhibiting ergosterol biosynthesis, we developed a novel method to differentiate fluconazole-susceptible from fluconazole-resistant isolates by quantitating ergosterol production in cells grown in 0, 1, 4, 16, or 64 μg of fluconazole per ml. Ergosterol was isolated from whole yeast cells by saponification, followed by extraction of nonsaponifiable lipids with heptane. Ergosterol was identified by its unique spectrophotometric absorbance profile between 240 and 300 nm. We used this sterol quantitation method (SQM) to test 38 isolates with broth microdilution end points of ≤8 μg/ml (susceptible), 16 to 32 μg/ml (susceptible dose-dependent [SDD]), or ≥64 μg/ml (resistant) and 10 isolates with trailing end points by the broth microdilution method. No significant differences in mean ergosterol content were observed between any of the isolates grown in the absence of fluconazole. However, 18 susceptible isolates showed a mean reduction in ergosterol content of 72% after exposure to 1 μg of fluconazole/ml, an 84% reduction after exposure to 4 μg/ml, and 95 and 100% reductions after exposure to 16 and 64 μg of fluconazole/ml, respectively. Ten SDD isolates showed mean ergosterol reductions of 38, 57, 73, and 99% after exposure to 1, 4, 16, and 64 μg of fluconazole/ml, respectively. In contrast, 10 resistant isolates showed mean reductions in ergosterol content of only 25, 38, 53, and 84% after exposure to the same concentrations of fluconazole. The MIC of fluconazole, by using the SQM, was defined as the lowest concentration of the drug which resulted in 80% or greater inhibition of overall mean ergosterol biosynthesis compared to that in the drug-free control. Of 38 isolates which gave clear end points by the broth microdilution method, the SQM MIC was within 2 dilutions of the broth microdilution MIC for 33 (87%). The SQM also discriminated between resistant and highly resistant isolates and was particularly useful for discerning the fluconazole susceptibilities of 10 additional isolates which gave equivocal end points by the broth microdilution method due to trailing growth. In contrast to the broth microdilution method, the SQM determined trailing isolates to be susceptible rather than resistant, indicating that the SQM may predict clinical outcome more accurately. The SQM may provide a means to enhance current methods of fluconazole susceptibility testing and may provide a better correlation of in vitro with in vivo results, particularly for isolates with trailing end points.
Two Sensitive PCR-Based Methods for Detection of Hepatitis B Virus Variants Associated with Reduced Susceptibility to Lamivudine
Authors: Allen Marchelle I. , Gauthier Josee , DesLauriers Manon , Bourne Eric J. , Carrick Kevin M. , Baldanti Fausto , Ross Lisa L. , Lutz Michael W. , Condreay Lynn D.
Published: December 2019

Two novel assays, a restriction fragment length polymorphism (RFLP) assay and an assay based on the 5′-nuclease activity of
Taq
DNA polymerase, were developed for screening viral variants in lamivudine-treated patients’ sera containing <1,000 copies of the hepatitis B virus (HBV) genome per ml. Both assays were designed to detect single-nucleotide changes within the HBV DNA polymerase gene that are associated with lamivudine resistance in vitro and have been used to screen a number of patients’ sera for variant virus. Results obtained with these assays and standard sequencing technology were compared with regard to throughput, ability to detect individual virus species present at low concentrations, and ability to detect, distinguish, and quantitate wild-type (wt) and HBV tyrosine methionine
552
aspartate aspartate motif variants in mixed viral populations. Unlike DNA sequencing, both assays are amenable to high-throughput screening and were shown to be able to quantitatively detect variant virus in the presence of a background of wt virus. As with DNA sequencing, both new assays incorporate a PCR amplification step and are able to detect the relatively low amounts of virus found in lamivudine-treated patients’ sera. However, these assays are far less labor intensive than the DNA-sequencing techniques presently in use. Overall, the RFLP assay was more sensitive than DNA sequencing in detecting and determining the ratios of wt to variant virus. Furthermore, the RFLP assay and 5′-nuclease assay were equally sensitive in the detection of mixed viral species, but the RFLP assay was superior to the 5′-nuclease assay in the quantitation of mixed viral species. These assays should prove useful for further understanding of virological response to therapy and disease progression.
Molecular Characterization of a Shiga Toxigenic
Escherichia coli
O113:H21 Strain Lacking
eae
Responsible for a Cluster of Cases of Hemolytic-Uremic Syndrome
Authors: Paton Adrienne W. , Woodrow Matthew C. , Doyle Robyn M. , Lanser Janice A. , Paton James C.
Published: December 2019

Shiga toxigenic
Escherichia coli
(STEC) strains are a diverse group of organisms capable of causing severe gastrointestinal disease in humans. Within the STEC family, certain strains appear to have greater virulence for humans. STEC strains carrying
eae
and belonging to serogroup O157 or O111 have been responsible for the vast majority of outbreaks of STEC disease reported to date. Here we describe a STEC O113:H21 strain lacking
eae
that was responsible for a cluster of three cases of hemolytic-uremic syndrome. This strain produces a single Stx2-related toxin and adheres efficiently to Henle 407 cells.
Comparison of Four Methodologies for Rapid and Cost-Effective Identification of
Candida glabrata
Authors: Fenn JoAnn P. , Billetdeaux Erick , Segal Helene , Skodack-Jones Lisa , Padilla Pamela E. , Bale Martha , Carroll Karen
Published: December 2019

To improve turnaround time and decrease the cost of the identification of
Candida glabrata
, we evaluated four methods for the detection of trehalose assimilation or fermentation. These methods were compared with the API 20C method (bioMERIEUX, Hazelwood, Mo.) to determine accuracy. We recommend the use of Remel Rapid Trehalose Assimilation Broth because of its rapid, 3-h results, reasonable sensitivity, and low number of false positives.
Transmission of an Azole-Resistant Isogenic Strain of
Candida albicans
among Human Immunodeficiency Virus-Infected Family Members with Oropharyngeal Candidiasis
Authors: Müller Frank-Michael C. , Kasai Miki , Francesconi Andrea , Brillante Beth , Roden Maureen , Peter Joanne , Chanock Stephen J. , Walsh Thomas J.
Published: December 2019

We report transmission of an azole-resistant, isogenic strain of
Candida albicans
in a human immunodeficiency virus (HIV)-infected family of two children with symptomatic oropharyngeal candidiasis and a mother with asymptomatic colonization over a 5-year period. These findings were confirmed by three different molecular epidemiology methods: interrepeat PCR, Southern hybridization with a
C. albicans
repetitive element 2 probe, and electrophoretic karyotyping. This study contributes to an evolving understanding of the mode of transmission of
C. albicans
, particularly in children, and underscores the importance of monitoring specimens from family members of HIV-infected patients.
Case-Control Study of Enteropathogens Associated with Childhood Diarrhea in Dhaka, Bangladesh
Authors: Albert M. John , Faruque A. S. G. , Faruque S. M. , Sack R. B. , Mahalanabis D.
Published: December 2019

The International Centre for Diarrhoeal Disease Research, Bangladesh, is a major center for research into diarrheal diseases. The center treats more than 100,000 patients a year. To obtain useful information representative of all patients, a surveillance system in which a 4% systematic sample of all patients is studied in detail, including etiological agents of diarrhea, was installed in October 1979. The first paper on etiology for the surveillance patients was published in 1982, which identified a potential enteric pathogen in 66% of patients. In subsequent years, several new agents of diarrhea have been identified. To assess the importance of a broader spectrum of diarrheal agents including the ones identified relatively recently, we studied 814 children with diarrhea. The children were up to 5 years of age and were part of the surveillance system. They were matched with an equal number of community controls without diarrhea. The study was conducted from February 1993 to June 1994. A potential enteric pathogen was isolated from 74.8% of diarrheal children and 43.9% of control children (
P
= 0.0001). Even though the first study was not a case-control study, it identified rotavirus,
Campylobacter jejuni
, enterotoxigenic
Escherichia coli
,
Shigella
spp., and
Vibrio cholerae
O1 as major pathogens. The present study identified these pathogens as being significantly associated with diarrhea. In addition, the study also identified six additional agents, including enteropathogenic
E. coli
,
Aeromonas
spp.,
V. cholerae
O139, enterotoxigenic
Bacteroides fragilis
,
Clostridium difficile
, and
Cryptosporidium parvum
, as being significantly associated with diarrhea.
Plesiomonas shigelloides
,
Salmonella
spp., diffusely adherent
E. coli
, enteroaggregative
E. coli
,
Entamoeba histolytica
, and
Giardia lamblia
were not significantly associated with diarrhea. Enteroinvasive
E. coli
, enterohemorrhagic
E. coli
, and
Cyclospora cayetanensis
were not detected in any of the children. The major burden of diseases due to most pathogens occurred in the first year of life. As in the previous study, seasonal patterns were seen for diarrhea associated with rotavirus,
V. cholerae
, and enterotoxigenic
E. coli
, and infections with multiple pathogens were common. With a few exceptions, these findings are in agreement with those from other developing countries. This knowledge of a broader spectrum of etiological agents of diarrhea in the surveillance patients will help us plan studies into various aspects of diarrheal diseases in this population.
Invasive and Noninvasive Group A Streptococcal Isolates with DifferentspeAAlleles in The Netherlands: Genetic Relatedness and Production of Pyrogenic Exotoxins A and B
Authors: Mascini Ellen M. , Jansze Margriet , Schouls Leo M. , Fluit Ad C. , Verhoef Jan , van Dijk Hans
Published: December 2019

Streptococcal pyrogenic exotoxin A (SPE-A) and SPE-B have been implicated in the pathogenesis of severe group A streptococcal (GAS) disease. We studied 31 invasive GAS strains including 18 isolates from patients with toxic shock syndrome and 22 noninvasive strains isolated in The Netherlands between 1994 and 1998. These strains were associated with the different allelic variants of the gene encoding SPE-A. We selected endemic strains withspeA-positive M and T serotypes:speA2-associated M1T1 and M22-60T12 strains,speA3-associated M3T3 strains, andspeA4-associated M6T6 strains. SincespeA1-positive isolates were not frequently encountered, we includedspeA1strains of different serotypes. The GAS strains were compared genotypically by pulsed-field gel electrophoresis and phenotypically by the in vitro production of SPE-A and SPE-B. All strains within one M and T type appeared to be of clonal origin. Most strains produced SPE-A and SPE-B, but only a minority of thespeA4-positive isolates did so. Among our isolates,speA1- andspeA3-positive strains produced significantly more SPE-A thanspeA2- andspeA4-carrying strains, while SPE-B production was most pronounced amongspeA1- andspeA2-containing strains. There was a marked degree of variability in the amounts of exotoxins produced in vitro by strains that shared the same genetic profile. We conclude that the differences in the in vitro production of SPE-A and SPE-B between our selected strains with identical M and T types were not related to either genetic heterogeneity or the clinical course of GAS disease in the patient from whom they were isolated.
Escherichia coli
O157:H7 and O157:H
−
Strains That Do Not Produce Shiga Toxin: Phenotypic and Genetic Characterization of Isolates Associated with Diarrhea and Hemolytic-Uremic Syndrome
Authors: Schmidt H. , Scheef J. , Huppertz H. I. , Frosch M. , Karch H.
Published: December 2019

We have isolated one sorbitol-nonfermenting (SNF)
Escherichia coli
O157:H7 isolate and five sorbitol-fermenting (SF)
E. coli
O157:H
−
isolates that do not contain Shiga toxin (Stx) genes (
stx
). Isolates originated from patients with diarrhea (
n
= 4) and hemolytic-uremic syndrome (HUS) (
n
= 2). All isolates harbored a chromosomal
eae
gene encoding gamma-intimin as well as the plasmid genes E-
hly
and
etp
. The
E. coli
O157:H7 isolate was
katP
and
espP
positive. Respective sera obtained from the patient with HUS contained antibodies to the O157 lipopolysaccharide antigen. The
stx
-negative
E. coli
O157:H7 isolate is genetically related to
stx
-positive SNF
E. coli
O157:H7. All
stx
-negative SF
E. coli
O157:H
−
isolates belong to the same genetic cluster and are closely related to
stx
-positive SF
E. coli
O157:H
−
isolates. Our data indicate that
stx
-negative
E. coli
O157:H7/H
−
variants may occur at a low frequency and cannot be recognized by diagnostic methods that target Stx.