Ellen Baron - Academia.edu (original) (raw)

Papers by Ellen Baron

Emerging Infectious Diseases, Nov 1, 2010

6. Jean J, Blais B, Darveau A, Fliss I. Simultaneous detection and identifi cation of hepatitis A... more 6. Jean J, Blais B, Darveau A, Fliss I. Simultaneous detection and identifi cation of hepatitis A virus and rotavirus by multiplex nucleic acid sequence-based amplifi cation (NASBA) and microtiter plate hybridization system.

The Journal of Molecular Diagnostics, Nov 1, 2011

The laboratory diagnosis of Clostridium difficile infection (CDI) continues to be challenging. Re... more The laboratory diagnosis of Clostridium difficile infection (CDI) continues to be challenging. Recent guidelines from professional societies in the United States note that enzyme immunoassays for toxins A and B do not have adequate sensitivity to be used alone for detecting CDI, yet the optimal method for diagnosing this infection remains unclear. Nucleic acid amplification tests (NAATs) that target chromosomal toxin genes (usually the toxin B gene, tcdB) show high sensitivity and specificity, provide rapid results, and are amenable to both batch and on-demand testing, but these tests were not universally recommended for routine use in the recent guidelines. Rather, two-step algorithms that use glutamate dehydrogenase (GDH) assays to screen for C. difficile in stool specimens, followed by either direct cytotoxin testing or culture to identify toxin-producing C. difficile isolates, were recommended in one guideline and either GDH algorithms or NAATs were recommended in another guideline. Unfortunately, neither culture nor direct cytotoxin testing is widely available. In addition, this two-step approach requires 48 to 92 hours to complete, which may delay the initiation of therapy and critical infection control measures. Recent studies also show the sensitivity of several GDH assays to be <90%. This review considers the role of NAATs for diagnosing CDI and explores their potential advantages over two-step algorithms, including shorter time to results, while providing comparable, if not superior, accuracy.

Clinical Infectious Diseases, Jun 1, 1995

Pathogenicity of microorganisms is a multifactorial phenomenon. Host environment plays a role in ... more Pathogenicity of microorganisms is a multifactorial phenomenon. Host environment plays a role in the development of the infectious process. The presence of key nutrients, such as iron, may be important for the expression of virulence factors. Iron is an essential ...

Clinical Infectious Diseases, Dec 1, 2005

An extensive blood culture protocol, including prolonged incubation of cultures, for 215 patients... more An extensive blood culture protocol, including prolonged incubation of cultures, for 215 patients believed to have had endocarditis yielded only 3 clinically relevant results. Twentyfour Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella (i.e., HACEK) organisms were recovered from standard 5-day blood cultures during the same time period. Specialized methods and not extended incubation times are recommended for recovery of fastidious agents of septicemia.

Antimicrobial Agents and Chemotherapy, Jun 1, 1987

Erythromycin ophthalmic ointment (E. Fougera & Co., Melville, N.Y.) and erythromycin gluceptate s... more Erythromycin ophthalmic ointment (E. Fougera & Co., Melville, N.Y.) and erythromycin gluceptate standards prepared in ointment base were stored at room temperature and heated at temperatures up to 45°C for as long as 6 h before being assayed for bioactivity. We were unable to detect any significant loss of antibiotic bioactivity.

Clinical Infectious Diseases, Mar 1, 1997

Clinical Microbiology Newsletter, Apr 1, 2017

Self-collected specimens for infectious disease testing are becoming more commonplace. There are ... more Self-collected specimens for infectious disease testing are becoming more commonplace. There are multiple published studies demonstrating that self-collected vaginal swabs for detection of sexually transmitted pathogens are as accurate as physician-collected endocervical swabs. Similarly, self-collected penile-meatal swabs are also acceptable for detecting sexually transmitted pathogens; however, unlike self-collected vaginal swabs, penile-meatal swabs are not considered an "on-label" specimen for U.S. FDA-cleared in vitro diagnostic products. Data on the accuracy of self-collected nasal specimens for respiratory tract infections are encouraging, but studies also show that patients do not always follow instructions when mailing samples back to the laboratory. Unfortunately, there are only a few reports of self-collected specimens for detecting enteric pathogens, such as Salmonella, Shigella, or Campylobacter. Microbiologists need to be proactive in making sure that training materials developed for selfcollection (such as laminated cards, videos, and other resources) are accurate and easy to understand (which includes being available in multiple languages) and provide clear instructions on how to handle a specimen once it has been collected.

Expert Opinion on Medical Diagnostics, Jul 28, 2012

Methicillin-resistant Staphylococcus aureus (MRSA) is among the most common causes of community- ... more Methicillin-resistant Staphylococcus aureus (MRSA) is among the most common causes of community- and healthcare-acquired infections, accounting for &amp;amp;amp;amp;amp;amp;amp;amp;gt; 80,000 invasive infections in the United States in 2010 according to the Center for Disease Control and Prevention&amp;amp;amp;amp;amp;amp;amp;amp;#39;s Active Bacterial Core Surveillance data. Control and treatment of MRSA depend on reliable identification, which is challenging. This article reviews the current status of detection and identification of MRSA. Publications since 2001, guidelines from the Clinical Laboratory Standards Institute and the European Committee on Antimicrobial Susceptibility Testing, common microbiology laboratory practices for identification and characterization of MRSA in human samples, and recent publications that assessed patient care outcomes of various detection and intervention strategies were surveyed for this review. Given the predilection of Staphylococcus aureus to modify its genetic characteristics, thereby enabling the species to stay one step ahead of laboratory detection systems, phenotypic methods for detection of antibiotic resistance mechanisms, especially those directed against the beta-lactam family, will continue to be required, in some situations, for the foreseeable future. Molecular methods are now the gold standard for surveillance, yielding higher sensitivity than the slower, culture-based methods. The newer molecular surveillance methods for detecting methicillin-resistant S. aureus (MRSA) colonization and for rapid and accurate identification of S. aureus from growth in culture systems have revolutionized patient care, enabling rapid interventions that lead to better individual patient outcomes, such as fewer postsurgical site infections, and better overall institutional infection control (fewer healthcare-associated MRSA infections).

Journal of Clinical Microbiology, Jul 1, 1979

Clinical Infectious Diseases, Jun 1, 1993

Bactericidal assays of Bacteroides gracilis (six strains) and Bilophila wadsworthia (12 strains) ... more Bactericidal assays of Bacteroides gracilis (six strains) and Bilophila wadsworthia (12 strains) in brucella broth with appropriate supplements were performed by the time-kill kinetic method. Antimicrobial agents tested were ampicillin/sulbactam (final concentrations, 16/8 micrograms/mL), ticarcillin/clavulanate (128/2 micrograms/mL), imipenem (8 micrograms/mL), cefoxitin (32 micrograms/mL), chloramphenicol (16 micrograms/mL), clindamycin (4 micrograms/mL), and metronidazole (16 micrograms/mL). Although all antimicrobial agents tested inhibited growth of all Bilophila strains during the first 24 hours, bactericidal activity was variable; only metronidazole was uniformly bactericidal. Most strains of Bilophila showed 1-2 log increases in growth at 6 hours with clindamycin and chloramphenicol. With chloramphenicol, some Bilophila strains tested showed regrowth starting at 30 hours. B. gracilis strains were generally more susceptible to all agents tested. Metronidazole, ticarcillin/clavulanate, chloramphenicol, and imipenem were most active. Several strains of B. gracilis were not killed by ampicillin/sulbactam, clindamycin, or cefoxitin. Activity was variable among strains and antimicrobial agents.

Clinical Infectious Diseases, Apr 15, 2004

PLOS ONE, Jul 3, 2009

Background: Blood agar is used for the identification and antibiotic susceptibility testing of ma... more Background: Blood agar is used for the identification and antibiotic susceptibility testing of many bacterial pathogens. In the developing world, microbiologists use human blood agar because of the high cost and inhospitable conditions for raising wool sheep or horses to supply blood. Many pathogens either fail to grow entirely or exhibit morphologies and hemolytic patterns on human blood agar that confound colony recognition. Furthermore, human blood can be hazardous to handle due to HIV and hepatitis [1,2]. This study investigated whether blood from hair sheep, a hardy, low-maintenance variety of sheep adapted for hot climates, was suitable for routine clinical microbiology studies. Methods and Findings: Hair sheep blood obtained by jugular venipuncture was anticoagulated by either manual defibrination or collection in human blood bank bags containing citrate-phosphate-dextrose. Trypticase soy 5% blood agar was made from both forms of hair sheep blood and commercial defibrinated wool sheep blood. Growth characteristics, colony morphologies, and hemolytic patterns of selected human pathogens, including several streptococcal species, were evaluated. Specialized identification tests, including CAMP test, reverse CAMP test, and satellite colony formation with Haemophilus influenzae and Abiotrophia defectiva were also performed. Mueller-Hinton blood agar plates prepared from the three blood types were compared in antibiotic susceptibility tests by disk diffusion and E-test. Conclusions: The results of all studies showed that blood agar prepared from citrated hair sheep blood is suitable for microbiological tests used in routine identification and susceptibility profiling of human pathogens. The validation of citrated hair sheep blood eliminates the labor-intensive and equipment-requiring process of manual defibrination. Use of hair sheep blood, in lieu of human blood currently used by many developing world laboratories and as an alternative to cost-prohibitive commercial sheep blood, offers the opportunity to dramatically improve the safety and accuracy of laboratory diagnosis of pathogenic bacteria in resource-poor countries.

Clinical Microbiology Newsletter, Jul 1, 2018

Journal of Clinical Microbiology, Sep 1, 2011

Clinical Infectious Diseases, Jun 1, 1993

We compared the Accu-CulShure guarded specimen collection device and a swab inserted into a B-D P... more We compared the Accu-CulShure guarded specimen collection device and a swab inserted into a B-D Port-a-Cul transport tube in terms of their efficacy under ideal conditions for recovery of bacteria from 10 decubitus ulcer specimens. Cultures yielded 57 aerobes and 21 anaerobes; 76 isolates were recovered with use of Accu-CulShure, and 72 isolates were recovered with use of Port-a-Cul. Both systems were comparable for recovery of organisms in terms of quantitative and qualitative results.

Clinical Infectious Diseases, Sep 1, 2002

Clinical Infectious Diseases, Jun 1, 1997

Clinical Infectious Diseases, Sep 15, 2010

Diagnosis and management of complicated intraabdominal infection in adults and children: guidelin... more Diagnosis and management of complicated intraabdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America. Clin Infect Dis 2010; 50(2):133-164. 3. Piacenti F. Treatment recommendations for patients from the community: concerns regarding the new guidelines for treatment of intra-abdominal infection [letter]. Clin Infect Dis 2010; 50(6):755-757 (in this issue).

Journal De Mycologie Medicale, Sep 1, 2009

Emerging Infectious Diseases, Nov 1, 2010

6. Jean J, Blais B, Darveau A, Fliss I. Simultaneous detection and identifi cation of hepatitis A... more 6. Jean J, Blais B, Darveau A, Fliss I. Simultaneous detection and identifi cation of hepatitis A virus and rotavirus by multiplex nucleic acid sequence-based amplifi cation (NASBA) and microtiter plate hybridization system.

The Journal of Molecular Diagnostics, Nov 1, 2011

The laboratory diagnosis of Clostridium difficile infection (CDI) continues to be challenging. Re... more The laboratory diagnosis of Clostridium difficile infection (CDI) continues to be challenging. Recent guidelines from professional societies in the United States note that enzyme immunoassays for toxins A and B do not have adequate sensitivity to be used alone for detecting CDI, yet the optimal method for diagnosing this infection remains unclear. Nucleic acid amplification tests (NAATs) that target chromosomal toxin genes (usually the toxin B gene, tcdB) show high sensitivity and specificity, provide rapid results, and are amenable to both batch and on-demand testing, but these tests were not universally recommended for routine use in the recent guidelines. Rather, two-step algorithms that use glutamate dehydrogenase (GDH) assays to screen for C. difficile in stool specimens, followed by either direct cytotoxin testing or culture to identify toxin-producing C. difficile isolates, were recommended in one guideline and either GDH algorithms or NAATs were recommended in another guideline. Unfortunately, neither culture nor direct cytotoxin testing is widely available. In addition, this two-step approach requires 48 to 92 hours to complete, which may delay the initiation of therapy and critical infection control measures. Recent studies also show the sensitivity of several GDH assays to be <90%. This review considers the role of NAATs for diagnosing CDI and explores their potential advantages over two-step algorithms, including shorter time to results, while providing comparable, if not superior, accuracy.

Clinical Infectious Diseases, Jun 1, 1995

Pathogenicity of microorganisms is a multifactorial phenomenon. Host environment plays a role in ... more Pathogenicity of microorganisms is a multifactorial phenomenon. Host environment plays a role in the development of the infectious process. The presence of key nutrients, such as iron, may be important for the expression of virulence factors. Iron is an essential ...

Clinical Infectious Diseases, Dec 1, 2005

An extensive blood culture protocol, including prolonged incubation of cultures, for 215 patients... more An extensive blood culture protocol, including prolonged incubation of cultures, for 215 patients believed to have had endocarditis yielded only 3 clinically relevant results. Twentyfour Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella (i.e., HACEK) organisms were recovered from standard 5-day blood cultures during the same time period. Specialized methods and not extended incubation times are recommended for recovery of fastidious agents of septicemia.

Antimicrobial Agents and Chemotherapy, Jun 1, 1987

Erythromycin ophthalmic ointment (E. Fougera & Co., Melville, N.Y.) and erythromycin gluceptate s... more Erythromycin ophthalmic ointment (E. Fougera & Co., Melville, N.Y.) and erythromycin gluceptate standards prepared in ointment base were stored at room temperature and heated at temperatures up to 45°C for as long as 6 h before being assayed for bioactivity. We were unable to detect any significant loss of antibiotic bioactivity.

Clinical Infectious Diseases, Mar 1, 1997

Clinical Microbiology Newsletter, Apr 1, 2017

Self-collected specimens for infectious disease testing are becoming more commonplace. There are ... more Self-collected specimens for infectious disease testing are becoming more commonplace. There are multiple published studies demonstrating that self-collected vaginal swabs for detection of sexually transmitted pathogens are as accurate as physician-collected endocervical swabs. Similarly, self-collected penile-meatal swabs are also acceptable for detecting sexually transmitted pathogens; however, unlike self-collected vaginal swabs, penile-meatal swabs are not considered an "on-label" specimen for U.S. FDA-cleared in vitro diagnostic products. Data on the accuracy of self-collected nasal specimens for respiratory tract infections are encouraging, but studies also show that patients do not always follow instructions when mailing samples back to the laboratory. Unfortunately, there are only a few reports of self-collected specimens for detecting enteric pathogens, such as Salmonella, Shigella, or Campylobacter. Microbiologists need to be proactive in making sure that training materials developed for selfcollection (such as laminated cards, videos, and other resources) are accurate and easy to understand (which includes being available in multiple languages) and provide clear instructions on how to handle a specimen once it has been collected.

Expert Opinion on Medical Diagnostics, Jul 28, 2012

Methicillin-resistant Staphylococcus aureus (MRSA) is among the most common causes of community- ... more Methicillin-resistant Staphylococcus aureus (MRSA) is among the most common causes of community- and healthcare-acquired infections, accounting for &amp;amp;amp;amp;amp;amp;amp;amp;gt; 80,000 invasive infections in the United States in 2010 according to the Center for Disease Control and Prevention&amp;amp;amp;amp;amp;amp;amp;amp;#39;s Active Bacterial Core Surveillance data. Control and treatment of MRSA depend on reliable identification, which is challenging. This article reviews the current status of detection and identification of MRSA. Publications since 2001, guidelines from the Clinical Laboratory Standards Institute and the European Committee on Antimicrobial Susceptibility Testing, common microbiology laboratory practices for identification and characterization of MRSA in human samples, and recent publications that assessed patient care outcomes of various detection and intervention strategies were surveyed for this review. Given the predilection of Staphylococcus aureus to modify its genetic characteristics, thereby enabling the species to stay one step ahead of laboratory detection systems, phenotypic methods for detection of antibiotic resistance mechanisms, especially those directed against the beta-lactam family, will continue to be required, in some situations, for the foreseeable future. Molecular methods are now the gold standard for surveillance, yielding higher sensitivity than the slower, culture-based methods. The newer molecular surveillance methods for detecting methicillin-resistant S. aureus (MRSA) colonization and for rapid and accurate identification of S. aureus from growth in culture systems have revolutionized patient care, enabling rapid interventions that lead to better individual patient outcomes, such as fewer postsurgical site infections, and better overall institutional infection control (fewer healthcare-associated MRSA infections).

Journal of Clinical Microbiology, Jul 1, 1979

Clinical Infectious Diseases, Jun 1, 1993

Bactericidal assays of Bacteroides gracilis (six strains) and Bilophila wadsworthia (12 strains) ... more Bactericidal assays of Bacteroides gracilis (six strains) and Bilophila wadsworthia (12 strains) in brucella broth with appropriate supplements were performed by the time-kill kinetic method. Antimicrobial agents tested were ampicillin/sulbactam (final concentrations, 16/8 micrograms/mL), ticarcillin/clavulanate (128/2 micrograms/mL), imipenem (8 micrograms/mL), cefoxitin (32 micrograms/mL), chloramphenicol (16 micrograms/mL), clindamycin (4 micrograms/mL), and metronidazole (16 micrograms/mL). Although all antimicrobial agents tested inhibited growth of all Bilophila strains during the first 24 hours, bactericidal activity was variable; only metronidazole was uniformly bactericidal. Most strains of Bilophila showed 1-2 log increases in growth at 6 hours with clindamycin and chloramphenicol. With chloramphenicol, some Bilophila strains tested showed regrowth starting at 30 hours. B. gracilis strains were generally more susceptible to all agents tested. Metronidazole, ticarcillin/clavulanate, chloramphenicol, and imipenem were most active. Several strains of B. gracilis were not killed by ampicillin/sulbactam, clindamycin, or cefoxitin. Activity was variable among strains and antimicrobial agents.

Clinical Infectious Diseases, Apr 15, 2004

PLOS ONE, Jul 3, 2009

Background: Blood agar is used for the identification and antibiotic susceptibility testing of ma... more Background: Blood agar is used for the identification and antibiotic susceptibility testing of many bacterial pathogens. In the developing world, microbiologists use human blood agar because of the high cost and inhospitable conditions for raising wool sheep or horses to supply blood. Many pathogens either fail to grow entirely or exhibit morphologies and hemolytic patterns on human blood agar that confound colony recognition. Furthermore, human blood can be hazardous to handle due to HIV and hepatitis [1,2]. This study investigated whether blood from hair sheep, a hardy, low-maintenance variety of sheep adapted for hot climates, was suitable for routine clinical microbiology studies. Methods and Findings: Hair sheep blood obtained by jugular venipuncture was anticoagulated by either manual defibrination or collection in human blood bank bags containing citrate-phosphate-dextrose. Trypticase soy 5% blood agar was made from both forms of hair sheep blood and commercial defibrinated wool sheep blood. Growth characteristics, colony morphologies, and hemolytic patterns of selected human pathogens, including several streptococcal species, were evaluated. Specialized identification tests, including CAMP test, reverse CAMP test, and satellite colony formation with Haemophilus influenzae and Abiotrophia defectiva were also performed. Mueller-Hinton blood agar plates prepared from the three blood types were compared in antibiotic susceptibility tests by disk diffusion and E-test. Conclusions: The results of all studies showed that blood agar prepared from citrated hair sheep blood is suitable for microbiological tests used in routine identification and susceptibility profiling of human pathogens. The validation of citrated hair sheep blood eliminates the labor-intensive and equipment-requiring process of manual defibrination. Use of hair sheep blood, in lieu of human blood currently used by many developing world laboratories and as an alternative to cost-prohibitive commercial sheep blood, offers the opportunity to dramatically improve the safety and accuracy of laboratory diagnosis of pathogenic bacteria in resource-poor countries.

Clinical Microbiology Newsletter, Jul 1, 2018

Journal of Clinical Microbiology, Sep 1, 2011

Clinical Infectious Diseases, Jun 1, 1993

We compared the Accu-CulShure guarded specimen collection device and a swab inserted into a B-D P... more We compared the Accu-CulShure guarded specimen collection device and a swab inserted into a B-D Port-a-Cul transport tube in terms of their efficacy under ideal conditions for recovery of bacteria from 10 decubitus ulcer specimens. Cultures yielded 57 aerobes and 21 anaerobes; 76 isolates were recovered with use of Accu-CulShure, and 72 isolates were recovered with use of Port-a-Cul. Both systems were comparable for recovery of organisms in terms of quantitative and qualitative results.

Clinical Infectious Diseases, Sep 1, 2002

Clinical Infectious Diseases, Jun 1, 1997

Clinical Infectious Diseases, Sep 15, 2010

Diagnosis and management of complicated intraabdominal infection in adults and children: guidelin... more Diagnosis and management of complicated intraabdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America. Clin Infect Dis 2010; 50(2):133-164. 3. Piacenti F. Treatment recommendations for patients from the community: concerns regarding the new guidelines for treatment of intra-abdominal infection [letter]. Clin Infect Dis 2010; 50(6):755-757 (in this issue).

Journal De Mycologie Medicale, Sep 1, 2009